Sample records for fuel recharge problem

  1. Oxygen electrodes for rechargeable alkaline fuel cells

    NASA Technical Reports Server (NTRS)

    Swette, L.; Kackley, N.

    1989-01-01

    Electrocatalysts and supports for the positive electrode of moderate temperature single-unit rechargeable alkaline fuel cells are being investigated and developed. Candidate support materials were drawn from transition metal carbides, borides, nitrides and oxides which have high conductivity (greater than 1 ohm/cm). Candidate catalyst materials were selected largely from metal oxides of the form ABO sub x (where A = Pb, Cd, Mn, Ti, Zr, La, Sr, Na, and B = Pt, Pd, Ir, Ru, Ni (Co) which were investigated and/or developed for one function only, O2 reduction or O2 evolution. The electrical conductivity requirement for catalysts may be lower, especially if integrated with a higher conductivity support. All candidate materials of acceptable conductivity are subjected to corrosion testing. Materials that survive chemical testing are examined for electrochemical corrosion activity. For more stringent corrosion testing, and for further evaluation of electrocatalysts (which generally show significant O2 evolution at at 1.4 V), samples are held at 1.6 V or 0.6 V for about 100 hours. The surviving materials are then physically and chemically analyzed for signs of degradation. To evaluate the bifunctional oxygen activity of candidate catalysts, Teflon-bonded electrodes are fabricated and tested in a floating electrode configuration. Many of the experimental materials being studied have required development of a customized electrode fabrication procedure. In advanced development, the goal is to reduce the polarization to about 300 to 350 mV. Approximately six support materials and five catalyst materials were identified to date for further development. The test results will be described.

  2. Recharge

    SciTech Connect

    Fayer, Michael J.

    2008-01-17

    This chapter describes briefly the nature and measurement of recharge in support of the CH2M HILL Tank Farm Vadose Zone Project. Appendix C (Recharge) and the Recharge Data Package (Fayer and Keller 2007) provide a more thorough and extensive review of the recharge process and the estimation of recharge rates for the forthcoming RCRA Facility Investigation report for Hanford single-shell tank (SST) Waste Management Areas (WMAs).

  3. Karst and artificial recharge: Theoretical and practical problems. A preliminary approach to artificial recharge assessment

    NASA Astrophysics Data System (ADS)

    Daher, Walid; Pistre, Séverin; Kneppers, Angeline; Bakalowicz, Michel; Najem, Wajdi

    2011-10-01

    SummaryManaged Aquifer Recharge (MAR) is an emerging sustainable technique that has already generated successful results and is expected to solve many water resource problems, especially in semi-arid and arid zones. It is of great interest for karst aquifers that currently supply 20-25% of the world's potable water, particularly in Mediterranean countries. However, the high heterogeneity in karst aquifers is too complex to be able to locate and describe them simply via field observations. Hence, as compared to projects in porous media, MAR is still marginal in karst aquifers. Accordingly, the present work presents a conceptual methodology for Aquifer Rechargeability Assessment in Karst - referred to as ARAK. The methodology was developed noting that artificial recharge in karst aquifers is considered an improbable challenge to solve since karst conduits may drain off recharge water without any significant storage, or recharge water may not be able to infiltrate. The aim of the ARAK method is to determine the ability of a given karst aquifer to be artificially recharged and managed, and the best sites for implementing artificial recharge from the surface. ARAK is based on multi-criteria indexation analysis modeled on karst vulnerability assessment methods. ARAK depends on four independent criteria, i.e. Epikarst, Rock, Infiltration and Karst. After dividing the karst domain into grids, these criteria are indexed using geological and topographic maps refined by field observations. ARAK applies a linear formula that computes the intrinsic rechargeability index based on the indexed map for every criterion, coupled with its attributed weighting rate. This index indicates the aptitude for recharging a given karst aquifer, as determined by studying its probability first on a regional scale for the whole karst aquifer, and then by characterizing the most favorable sites. Subsequently, for the selected sites, a technical and economic feasibility factor is applied, weighted by the difficulties that could occur when trying to undertake a recharge operation at a selected site from the surface. Each site is finally rated by its rechargeability index - the product of two factors, the intrinsic rechargeability and the feasibility index. ARAK was applied to the region of Damour, Lebanon, on the Mediterranean coast where uncontrolled exploitation of public and private wells led to its partial salinization by seawater. A MAR system in Damour region represents an interesting solution to cope with salinization and the insufficiency of the resource.

  4. Oxygen electrodes for rechargeable alkaline fuel cells-II

    NASA Technical Reports Server (NTRS)

    Swette, L.; Kackley, N.

    1989-01-01

    The primary objective of this program is the investigation and development of electrocatalysts and supports for the positive electrode of moderate temperature single-unit rechargeable alkaline fuel cells. Approximately six support materials and five catalyst materials have been identified to date for further development.

  5. Positive Energy From rechargeable batteries to fuel cells: electrochemical energy as one

    E-print Network

    Andelman, David

    of the fascinating and green alternatives to combustion engines Yaakov Vilenchik1 , David Andelman2 and Emanuel such as rechargeable batteries and fuel cells, which in the future could replace the combustion engine. We equally with oxygen in the air), which in turn is used to heat water into steam. Steam under high pressure has large

  6. Unitized Regenerative Fuel Cells for solar rechargeable aircraft and zero emission vehicles

    Microsoft Academic Search

    Fred Mitlitsky; Nicholas J. Colella; Blake Myers

    1994-01-01

    A unitized regenerative fuel cell (URFC) produces power and electrolytically regenerates its reactants using a single stack of reversible cells. URFC'S have been designed for high altitude long endurance (HALE) solar rechargeable aircraft (SRA), zero emission vehicles (ZEV's), hybrid energy storage\\/propulsion systems for long duration satellites, energy storage for remote (off-grid) power sources, and peak shaving for on-grid applications. URFC's

  7. Unitized regenerative fuel cells for solar rechargeable aircraft and zero emission vehicles

    SciTech Connect

    Mitlitsky, F.; Colella, N.J.; Myers, B.

    1994-09-06

    A unitized regenerative fuel cell (URFC) produces power and electrolytically regenerates its reactants using a single stack of reversible cells. URFCs have been designed for high altitude long endurance (HALE) solar rechargeable aircraft (SRA), zero emission vehicles (ZEVs), hybrid energy storage/propulsion systems for long duration satellites, energy storage for remote (off-grid) power sources, and peak shaving for on-grid applications. URFCs have been considered using hydrogen/oxygen, hydrogen/air, or hydrogen/halogen chemistries. This discussion is limited to the lightweight URFC energy storage system designs for span-loaded HALE SRA using hydrogen/oxygen, and for ZEVs using hydrogen/air with oxygen supercharging. Overlapping and synergistic development and testing opportunities for these two technologies will be highlighted.

  8. Unitized Regenerative Fuel Cells for solar rechargeable aircraft and zero emission vehicles

    NASA Astrophysics Data System (ADS)

    Mitlitsky, Fred; Colella, Nicholas J.; Myers, Blake

    1994-09-01

    A unitized regenerative fuel cell (URFC) produces power and electrolytically regenerates its reactants using a single stack of reversible cells. URFC'S have been designed for high altitude long endurance (HALE) solar rechargeable aircraft (SRA), zero emission vehicles (ZEV's), hybrid energy storage/propulsion systems for long duration satellites, energy storage for remote (off-grid) power sources, and peak shaving for on-grid applications. URFC's have been considered using hydrogen/oxygen, hydrogen/air, or hydrogen/halogen chemistries. This discussion is limited to the lightweight URFC energy storage system designs for span-loaded HALE SRA using hydrogen/oxygen, and for ZEV's using hydrogen/air with oxygen supercharging. Overlapping and synergistic development and testing opportunities for these two technologies will be highlighted.

  9. An overview—Functional nanomaterials for lithium rechargeable batteries, supercapacitors, hydrogen storage, and fuel cells

    SciTech Connect

    Liu, Hua Kun, E-mail: hua@uow.edu.au

    2013-12-15

    Graphical abstract: Nanomaterials play important role in lithium ion batteries, supercapacitors, hydrogen storage and fuel cells. - Highlights: • Nanomaterials play important role for lithium rechargeable batteries. • Nanostructured materials increase the capacitance of supercapacitors. • Nanostructure improves the hydrogenation/dehydrogenation of hydrogen storage materials. • Nanomaterials enhance the electrocatalytic activity of the catalysts in fuel cells. - Abstract: There is tremendous worldwide interest in functional nanostructured materials, which are the advanced nanotechnology materials with internal or external dimensions on the order of nanometers. Their extremely small dimensions make these materials unique and promising for clean energy applications such as lithium ion batteries, supercapacitors, hydrogen storage, fuel cells, and other applications. This paper will highlight the development of new approaches to study the relationships between the structure and the physical, chemical, and electrochemical properties of functional nanostructured materials. The Energy Materials Research Programme at the Institute for Superconducting and Electronic Materials, the University of Wollongong, has been focused on the synthesis, characterization, and applications of functional nanomaterials, including nanoparticles, nanotubes, nanowires, nanoporous materials, and nanocomposites. The emphases are placed on advanced nanotechnology, design, and control of the composition, morphology, nanostructure, and functionality of the nanomaterials, and on the subsequent applications of these materials to areas including lithium ion batteries, supercapacitors, hydrogen storage, and fuel cells.

  10. Water Table Fluctuations Induced by Intermittent Recharge

    Microsoft Academic Search

    Marinus Maasland

    1959-01-01

    The problem of water table fluctuations in response to repeated recharges is considered. The effect on the water table of intermittent constant recharge (recharge applied intermittently at a constant rate) and of intermittent instantaneous recharge (recharge applied instantaneoulsy at regular intervals) is analyzed in detail. The final results are shown to consist of a combination of periodic and transient components;

  11. Theoretical performance of hydrogen-bromine rechargeable SPE fuel cell. [Solid Polymer Electrolyte

    NASA Technical Reports Server (NTRS)

    Savinell, R. F.; Fritts, S. D.

    1988-01-01

    A mathematical model was formulated to describe the performance of a hydrogen-bromine fuel cell. Porous electrode theory was applied to the carbon felt flow-by electrode and was coupled to theory describing the solid polymer electrolyte (SPE) system. Parametric studies using the numerical solution to this model were performed to determine the effect of kinetic, mass transfer, and design parameters on the performance of the fuel cell. The results indicate that the cell performance is most sensitive to the transport properties of the SPE membrane. The model was also shown to be a useful tool for scale-up studies.

  12. Zero-CO2 emission and low-crossover 'rechargeable' PEM fuel cells using cyclohexane as an organic hydrogen reservoir.

    PubMed

    Kariya, Nobuko; Fukuoka, Atsushi; Ichikawa, Masaru

    2003-03-21

    High performance (open circuit voltage = 920 mV, maximum power density = 14-15 mW cm(-2)) of the PEM fuel cell was achieved by using cyclohexane as a fuel with zero-CO2 emission and lower-crossover through PEM than with a methanol-based fuel cell. PMID:12703775

  13. Multiple Vehicle Routing Problem with Fuel Constraints

    E-print Network

    Levy, David

    2013-06-26

    are required. Once these have been determined, the first neighborhood N1 is chosen as the ?current? neighborhood. A concise description of the algorithm is shown in Figure 3-5. In this figure, step 3 is the Shaking step, step 4 is the Local Search step... were developed: APD and MVGS. 4.2 Neighborhood Configuration Investigation The above multiple vehicle algorithm was run for 23 problem instances, with names ranging from p01 to p21, and pr01 to pr21. Complete detailed results for these instances...

  14. An ultrafast rechargeable aluminium-ion battery.

    PubMed

    Lin, Meng-Chang; Gong, Ming; Lu, Bingan; Wu, Yingpeng; Wang, Di-Yan; Guan, Mingyun; Angell, Michael; Chen, Changxin; Yang, Jiang; Hwang, Bing-Joe; Dai, Hongjie

    2015-04-16

    The development of new rechargeable battery systems could fuel various energy applications, from personal electronics to grid storage. Rechargeable aluminium-based batteries offer the possibilities of low cost and low flammability, together with three-electron-redox properties leading to high capacity. However, research efforts over the past 30 years have encountered numerous problems, such as cathode material disintegration, low cell discharge voltage (about 0.55 volts; ref. 5), capacitive behaviour without discharge voltage plateaus (1.1-0.2 volts or 1.8-0.8 volts) and insufficient cycle life (less than 100 cycles) with rapid capacity decay (by 26-85 per cent over 100 cycles). Here we present a rechargeable aluminium battery with high-rate capability that uses an aluminium metal anode and a three-dimensional graphitic-foam cathode. The battery operates through the electrochemical deposition and dissolution of aluminium at the anode, and intercalation/de-intercalation of chloroaluminate anions in the graphite, using a non-flammable ionic liquid electrolyte. The cell exhibits well-defined discharge voltage plateaus near 2 volts, a specific capacity of about 70 mA h g(-1) and a Coulombic efficiency of approximately 98 per cent. The cathode was found to enable fast anion diffusion and intercalation, affording charging times of around one minute with a current density of ~4,000 mA g(-1) (equivalent to ~3,000 W kg(-1)), and to withstand more than 7,500 cycles without capacity decay. PMID:25849777

  15. Fuel-optimal trajectories for aeroassisted coplanar orbital transfer problem

    NASA Technical Reports Server (NTRS)

    Naidu, Desineni Subbaramaiah; Hibey, Joseph L.; Charalambous, Charalambos D.

    1990-01-01

    The optimal control problem arising in coplanar orbital transfer employing aeroassist technology is addressed. The maneuver involves the transfer from high to low earth orbit via the atmosphere, with the object of minimizing the total fuel consumption. Simulations are carried out to obtain the fuel-optimal trajectories for flying the spacecraft through the atmosphere. A highlight is the application of an efficient multiple-shooting method for treating the nonlinear two-point boundary value problem resulting from the optimizaion procedure. The strategy for the atmospheric portion of the minimum-fuel transfer is to fly at the maximum lift-to-drag ratio L/D initially in order to recover from the downward plunge, and then to fly at a negative L/D to level off the flight so that the vehicle skips out of the atmosphere with a flight path angle near zero degrees.

  16. Fuel-optimal trajectories for aeroassisted coplanar orbital transfer problem

    NASA Technical Reports Server (NTRS)

    Naidu, D. S.; Hibey, J. L.; Charalambous, C.

    1988-01-01

    The optimal-control problem arising in coplanar orbital transfer using aeroassist technology is addressed. The maneuver involves the transfer from high earth orbit to low earth orbit with minimum fuel consumption. Simulations are carried out to obtain a corridor of entry conditions which are suitable for flying the spacecraft through the atmosphere. A highlight of the present work is the application of an efficient multiple shooting method for handling the difficult nonlinear two-point boundary value problem resulting from the optimization procedure.

  17. Appendix C: Recharge

    SciTech Connect

    Fayer, Michael J.; Keller, Jason M.

    2008-01-17

    This appendix provides estimates of recharge rates for the soil and vegetation conditions in and around the single-shell tank (SST) waste management areas (WMAs). The purpose is to combine published data with recent information to provide the most current recharge estimates. Recharge rates were estimated for areas that remain natural and undisturbed, areas where the vegetation has been disturbed, areas where both the vegetation and the soil have been disturbed, and areas that are engineered (e.g., surface barrier). Methods used include lysimetry, tracers, and simuations. This appendix summarizes the information in the recharge data package for the SST Waste Management Areas), which builds upon previous reports on the Hanford vadose zone data and Integrated Disposal Facility recharge with information available after those reports were published, including field measurements and simulations using weather data through 2006.

  18. Accounting for intracell flow in models with emphasis on water table recharge and stream-aquifer interaction. 1. Problems and concepts

    USGS Publications Warehouse

    Jorgensen, D.G.; Signor, D.C.; Imes, J.L.

    1989-01-01

    One method of modeling multiple sources and sinks is to determine the net recharge per cell. For example, for a model cell containing both a sink and recharge through the water table, the amount of recharge should be reduced by the ratio of the area of influence of the sink within the cell to the area of the cell. The reduction is the intercepted portion of the recharge. In a multilayer model this amount is further reduced by a proportion factor, which is a function of the depth of the flow lines from the water table boundary to the internal sink. A gaining section of a stream is a typical sink. The aquifer contribution to a gaining stream can be conceptualized as having two parts; the first part is the intercepted lateral flow from the water table and the second is the flow across the streambed due to differences in head between the water level in the stream and the aquifer below. The amount intercepted is a function of the geometry of the cell, but the amount due to difference in head across the stream bed is largely independent of cell geometry. -from Authors

  19. Artificial recharge of groundwater

    NASA Astrophysics Data System (ADS)

    The Task Committee on Guidelines for Artificial Recharge of Groundwater, of the American Society of Civil Engineers' (ASCE) Irrigation and Drainage Division, sponsored an International Symposium on Artificial Recharge of Groundwater at the Inn-at-the-Park Hotel in Anaheim, Calif., August 23-27, 1988. Cosponsors were the U.S. Geological Survey, California Department of Water Resources, University of California Water Resources Center, Metropolitan Water District of Southern California, with cooperation from the U.S. Bureau of Reclamation, International Association of Hydrological Sciences, American Water Resources Association, U.S. Agency for International Development, World Bank, United Nations Department of Technical Cooperation for Development, and a number of local and state organizations.Because of the worldwide interest in artificial recharge and the need to develop efficient recharge facilities, the Anaheim symposium brought together an interdisciplinary group of engineers and scientists to provide a forum for many professional disciplines to exchange experiences and findings related to various types of artificial recharge; learn from both successful and unsuccessful case histories; promote technology transfer between the various disciplines; provide an education resource for communication with those who are not water scientists, such as planners, lawyers, regulators, and the public in general; and indicate directions by which cities or other entities can save funds by having reasonable technical guidelines for implementation of a recharge project.

  20. Rechargeable hybrid aqueous batteries

    NASA Astrophysics Data System (ADS)

    Yan, Jing; Wang, Jing; Liu, Hao; Bakenov, Zhumabay; Gosselink, Denise; Chen, P.

    2012-10-01

    A new aqueous rechargeable battery combining an intercalation cathode with a metal (first order electrode) anode has been developed. The concept is demonstrated using LiMn2O4 and zinc metal electrodes in an aqueous electrolyte containing two electrochemically active ions (Li+ and Zn2+). The battery operates at about 2 V and preliminarily tests show excellent cycling performance, with about 90% initial capacity retention over 1000 charge-discharge cycles. Use of cation-doped LiMn2O4 cathode further improves the cyclability of the system, which reaches 95% capacity retention after 4000 cycles. The energy density for a prototype battery, estimated at 50-80 Wh kg-1, is comparable or superior to commercial 2 V rechargeable batteries. The combined performance attributes of this new rechargeable aqueous battery indicate that it constitutes a viable alternative to commercial lead-acid system and for large scale energy storage application.

  1. Lightweight aircraft engines, the potential and problems for use of automotive fuels

    NASA Technical Reports Server (NTRS)

    Patterson, D. J.

    1983-01-01

    A comprehensive data research and analysis for evaluating the use of automotive fuels as a substitute for aviation grade fuel by piston-type general aviation aircraft engines is presented. Historically known problems and potential problems with fuels were reviewed for possible impact relative to application to an aircraft operational environment. This report reviews areas such as: fuel specification requirements, combustion knock, preignition, vapor lock, spark plug fouling, additives for fuel and oil, and storage stability.

  2. Assessing the potential for significant and episodic recharge in southwestern Australia using rainfall data

    NASA Astrophysics Data System (ADS)

    Lewis, Fay M.; Walker, Glen R.

    2002-02-01

    Agricultural practices in semi-arid parts of southwestern Australia have increased recharge and raised groundwater levels. As a result, land salinization has occurred. Managers aim to address the problem by reducing recharge, but it is not known whether all recharge is regular and seasonal or whether a substantial component is episodic (i.e. occurs in irregular pulses). Approaches that reduce regular recharge may not be effective at reducing recharge that is episodic. Water balances were used to assess the potential for recharge to be episodic at 53 sites throughout Western Australia. The results show that, for the conditions modeled, a substantial proportion of the recharge in drier parts of the agricultural areas occurred episodically, and that direct episodic recharge could be as important in some semi-arid areas as in arid regions. Therefore, mean annual rainfall is not a strong predictor of the ratio of episodic to total recharge at a site. The model indicates that in agricultural areas, most significant and episodic recharge events occurred over just a few days in winter months, when rainfall was dominated by frontal systems. However, substantial episodic recharge also resulted from large storms during the months of January, February, and March. The implication is that it will be difficult to reduce recharge substantially, and thus control salinity, as long as agriculture relies heavily on shallow-rooted winter-growing plants.

  3. Extended Run Fuel Cell Backup Power: Solving the Hydrogen Problem

    Microsoft Academic Search

    H. Koyama

    2006-01-01

    Founded in 1996, IdaTech has become a leader in the development of fuel processors and integrated fuel cell systems for portable power, critical backup power and remote power applications world-side. The company is focusing on the commercial deployment of PEM fuel cell solutions for a wide range of power generation needs including critical backup, remote and portable applications. IdaTech's core

  4. Hydrogen Fuel Cell Problems 1) Explain why the hydrogen fuel cell vehicle is not as efficient as the reported "tank

    E-print Network

    Bowen, James D.

    Hydrogen Fuel Cell Problems 1) Explain why the hydrogen fuel cell vehicle is not as efficient as the reported "tank to wheel" efficiencies would suggest. Hydrogen must be produced, stored, and transported to heat and leaking of hydrogen in the atmosphere. Additionally it takes power to produce hydrogen

  5. Rechargeable Magnesium Power Cells

    NASA Technical Reports Server (NTRS)

    Koch, Victor R.; Nanjundiah, Chenniah; Orsini, Michael

    1995-01-01

    Rechargeable power cells based on magnesium anodes developed as safer alternatives to high-energy-density cells like those based on lithium and sodium anodes. At cost of some reduction in energy density, magnesium-based cells safer because less susceptible to catastrophic meltdown followed by flames and venting of toxic fumes. Other advantages include ease of handling, machining, and disposal, and relatively low cost.

  6. REMOTELY RECHARGEABLE EPD

    SciTech Connect

    Vrettos, N; Athneal Marzolf, A; Scott Bowser, S

    2007-11-13

    Radiation measurements inside the Contact Decon Maintenance Cell (CDMC) in the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) are required to determine stay times for personnel. A system to remotely recharge the transmitter of an Electronic Personnel Dosimeter (EPD) and bail assembly to transport the EPD within the CDMC was developed by the Savannah River National Laboratory (SRNL) to address this need.

  7. Advanced Small Rechargeable Batteries

    NASA Technical Reports Server (NTRS)

    Halpert, Gerald

    1989-01-01

    Lithium-based units offer highest performance. Paper reviews status of advanced, small rechargeable batteries. Covers aqueous systems including lead/lead dioxide, cadmium/nickel oxide, hydrogen/nickel oxide, and zinc/nickel oxide, as well as nonaqueous systems. All based on lithium anodes, nonaqueous systems include solid-cathode cells (lithium/molybdenum disulfide, lithium/titanium disulfide, and lithium/vanadium oxide); liquid-cathode cells (lithium/sulfur dioxide cells); and new category, lithium/polymer cells.

  8. Fuel Cell Application Problems: Study Guide for AP Chemistry

    NSDL National Science Digital Library

    Cox, Brian A.

    This study guide is intended for 10th-12th grade AP chemistry students studying fuel cell technology. Applicable National Science Education Standards are included in the document. The study guide includes a comparison of gasoline and hydrogen, a section on kinetic molecular theory, a section on electrochemistry and material on hydrogen fuel cells. This document may be downloaded in PDF file format.

  9. Materials development and corrosion problems in nuclear fuel reprocessing plants

    Microsoft Academic Search

    Baldev Raj; U. Kamachi Mudali

    2006-01-01

    A broad based materials development programme has been in progress worldwide towards the development of materials for applications in spent nuclear fuel reprocessing plants. International efforts have resulted in the development of advanced materials like nitric acid grade (NAG) special austenitic stainless steels, Ti–5% Ta, Ti–5% Ta–1.8% Nb, Cr–W–Si, Nb–W, zirconium based alloys etc. for highly corrosive nitric acid environments.

  10. Variable motor-fuel taxes: problems and prospects

    Microsoft Academic Search

    D. J. Forkenbrock; C. A. Hoefer

    1983-01-01

    The aging US highway system faces maintenance and reconstruction costs as high as $220 billion, which exceeds traditional highway user-tax revenues. The use of heavier trucks that accelerate highway wear compounds the decline in revenue from changes in travel patterns and the economic downturn. Data from Iowa are used to compare gasoline-tax schemes that replace unit motor-fuel taxes with variable

  11. The growing problem of stranded used nuclear fuel.

    PubMed

    Alley, William M; Alley, Rosemarie

    2014-02-18

    By 2050, almost all U.S. nuclear reactors will have reached their 60 year maximum expected life. Many will shut down sooner. With no assurance that the current approach for finding a geologic repository or interim storage sites will succeed, used nuclear fuel could be stranded indefinitely at more than 70 sites in 35 states. Societal discussions about the future of nuclear waste should be framed in terms of the relative risks of all alternatives. We review and compare onsite storage, interim storage, and a geologic repository, as well as how these alternatives are presented to the public. PMID:24437358

  12. Fuel resource scheduling, part I - overview of an energy management problem

    SciTech Connect

    Vemuri, S.; Eisenhauer, J.; Hackett, D.F.; Kumar, A.B.R.; Lugtu, R.

    1984-07-01

    This paper at an overview level discusses the problems of Fuel and Resource Scheduling (FRS) in an Energy Management System (EMS). For a computer-based FRS, a hierarchical scheduling scheme is proposed so that long-term fuel strategy over a year can be meaningfully translated into real-time decisions for loading the units. In this process FRS has been decomposed into individual problems of Resource Budgeting for long-term fuel scheduling, Resource Scheduling for short-term fuel scheduling, and real-time fuel scheduling functions of Real-Time Resource Scheduling and Resource Constrained Economic Dispatch. The paper addresses the data requirements and the technical problems associated with each individual function; and the coordination of these four functions in an EMS environment.

  13. Modeling of Gap Closure in Uranium-Zirconium Alloy Metal Fuel - A Test Problem

    SciTech Connect

    Simunovic, Srdjan [ORNL; Ott, Larry J [ORNL; Gorti, Sarma B [ORNL; Nukala, Phani K [ORNL; Radhakrishnan, Balasubramaniam [ORNL; Turner, John A [ORNL

    2009-10-01

    Uranium based binary and ternary alloy fuel is a possible candidate for advanced fast spectrum reactors with long refueling intervals and reduced liner heat rating [1]. An important metal fuel issue that can impact the fuel performance is the fuel-cladding gap closure, and fuel axial growth. The dimensional change in the fuel during irradiation is due to a superposition of the thermal expansion of the fuel due to heating, volumetric changes due to possible phase transformations that occur during heating and the swelling due to fission gas retention. The volumetric changes due to phase transformation depend both on the thermodynamics of the alloy system and the kinetics of phase change reactions that occur at the operating temperature. The nucleation and growth of fission gas bubbles that contributes to fuel swelling is also influenced by the local fuel chemistry and the microstructure. Once the fuel expands and contacts the clad, expansion in the radial direction is constrained by the clad, and the overall deformation of the fuel clad assembly depends upon the dynamics of the contact problem. The neutronics portion of the problem is also inherently coupled with microstructural evolution in terms of constituent redistribution and phase transformation. Because of the complex nature of the problem, a series of test problems have been defined with increasing complexity with the objective of capturing the fuel-clad interaction in complex fuels subjected to a wide range of irradiation and temperature conditions. The abstract, if short, is inserted here before the introduction section. If the abstract is long, it should be inserted with the front material and page numbered as such, then this page would begin with the introduction section.

  14. Conclusions and recommendations. [for problems in energy situation, air transportation, and hydrogen fuel

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Conclusions and recommendations are presented for an analysis of the total energy situation; the effect of the energy problem on air transportation; and hydrogen fuel for aircraft. Properties and production costs of fuels, future prediction for energy and transportation, and economic aspects of hydrogen production are appended.

  15. Case studies––Problem solving in fluidized bed waste fuel incineration

    Microsoft Academic Search

    Rong Yan; David Tee Liang; Leslie Tsen

    2005-01-01

    Fluidized bed combustion technology has been widely used as the new, flexible, multi-fuel boiler for waste combustion and energy recovery from low grade fuels. However, problems such as low thermal efficiency, high emissions, bed agglomeration etc. are still encountered in the operation of fluidized beds. Valuable experiences were gained from two case studies recently conducted regarding wastes combustion in industrial

  16. Near-Optimal Mobile Robot Recharging with the Rate-Maximizing Forager

    Microsoft Academic Search

    Jens Wawerla; Richard T. Vaughan

    2007-01-01

    We examine the practical problem of a mobile autonomous robot performing a long-duration survey task, during which it must recharge its batteries periodically. We present a scalable, online, heuristic method that allows the robot to recharge efficiently, thus maximizing its rate of work. The method is a direct application of the rate-maximizing foraging model, which seeks to explain the behaviour

  17. Issue and challenges facing rechargeable thin film lithium batteries

    Microsoft Academic Search

    Arun Patil; Vaishali Patil; Dong Wook Shin; Ji-Won Choi; Dong-Soo Paik; Seok-Jin Yoon

    2008-01-01

    New materials hold the key to fundamental advances in energy conversion and storage, both of which are vital in order to meet the challenge of global warming and the finite nature of fossil fuels. Nanomaterials in particular offer unique properties or combinations of properties as electrodes and electrolytes in a range of energy devices. Technological improvements in rechargeable solid-state batteries

  18. Carbon materials for lithium-ion rechargeable batteries

    Microsoft Academic Search

    S. Flandrois; B. Simon

    1999-01-01

    The recent development of lithium rechargeable batteries results from the use of carbon materials as lithium reservoir at the negative electrode. Reversible intercalation, or insertion, of lithium into the carbon host lattice avoids the problem of lithium dendrite formation and provides large improvement in terms of cycleability and safety. This paper reviews the main achievements on performance and understanding of

  19. Modeling of multi-body thermo-mechanical and contact problems in CANDU fuel

    Microsoft Academic Search

    S. D. Yu; S. Xu; H. H. Yang

    2004-01-01

    Modeling and analysis of three-dimensional thermo-mechanical and multi-body contact problems in a CANDU®3CANDU is a registered trade mark of the Atomic Energy of Canada Ltd. (AECL).3 nuclear fuel element are presented in this paper. Each axisymmetric component in a fuel element is first modeled using the three-dimensional nine-node harmonic finite elements. All interior degrees of freedom (DOF’s) in the component

  20. A study of altitude and flight path angle dynamics for a singularly perturbed fuel optimization problem

    NASA Technical Reports Server (NTRS)

    Price, D. B.; Gracey, C.

    1983-01-01

    This short paper will demonstrate that the separation of altitude and flight path angle dynamics using singular perturbation techniques for a transport fuel optimization problem results in an unacceptable oscillation in altitude. A technique for damping this oscillation by adding a penalty term to the cost function for the optimization problem will be discussed. This technique will be compared with a different approach that linearizes the altitude and flight path angle boundary layers.

  1. Nanostructured cathode materials for rechargeable lithium batteries

    NASA Astrophysics Data System (ADS)

    Myung, Seung-Taek; Amine, Khalil; Sun, Yang-Kook

    2015-06-01

    The prospect of drastic climate change and the ceaseless fluctuation of fossil fuel prices provide motivation to reduce the use of fossil fuels and to find new energy conversion and storage systems that are able to limit carbon dioxide generation. Among known systems, lithium-ion batteries are recognized as the most appropriate energy storage system because of their high energy density and thus space saving in applications. Introduction of nanotechnology to electrode material is beneficial to improve the resulting electrode performances such as capacity, its retention, and rate capability. The nanostructure is highly available not only when used alone but also is more highlighted when harmonized in forms of core-shell structure and composites with carbon nanotubes, graphene or reduced graphene oxides. This review covers syntheses and electrochemical properties of nanoscale, nanosized, and nanostructured cathode materials for rechargeable lithium batteries.

  2. Improving Spatially Distributed Regional Recharge Estimation

    Microsoft Academic Search

    Zainab Zomlot; Okke Batelaan

    2010-01-01

    Spatial and temporal variability of groundwater recharge are key factors that need to be quantified to determine the sustainability of groundwater resources. In response to the need for better estimates of groundwater recharge the WetSpass spatially distributed water balance model was developed and applied for Flanders. This model aims to simulate long-term average recharge depending on land cover, soil texture,

  3. Low NPSH process pumps solve instability problems in fuel-grade ethanol plant

    Microsoft Academic Search

    R. B. Andersen; A. Gaines

    1984-01-01

    South Point Ethanol, one of the nation's largest producers of denatured ethyl alcohol for blending with motor fuels, encountered severe instability problems with certain pumps when the plant in South Point, Ohio went on-stream in September 1982. The ethanol is produced by fermenting the starch in cooked corn and other grains. Two 4 x 3'' centrifugal pumps with 13'' casing

  4. Alternative Fuels and Hybrid Technology: A Classroom Activity Designed to Evaluate a Contemporary Problem

    ERIC Educational Resources Information Center

    Roy MacArthur, Amy H.; Copper, Christine L.

    2009-01-01

    As petroleum reserves are being depleted worldwide and energy costs are increasing, the use of alternative fuels is being more widely considered as a solution to the impending energy crisis. In this classroom activity students are presented with a real-world problem in which they must evaluate the properties and environmental impacts of a variety…

  5. Revised 06-2011 Rechargeable

    E-print Network

    Taylor, Jerry

    the Sustainability Office at 573-884-9319. #12;Revised 06-2011 Examples of Recyclable Batteries Lithium Lead Acid Button Lithium Leaking Lead Acid Alkaline Silver (Ag), Lithium (Li), Mercury (Hg) Li Primary Pb Acid AARevised 06-2011 Rechargeable Battery And Cell Phone Recycling Program Guidelines University

  6. Self-recharging virtual currency

    Microsoft Academic Search

    David Irwin; Jeff Chase; Laura Grit; Aydan Yumerefendi

    2005-01-01

    Market-based control is attractive for networked computing utilities in which consumers compete for shared resources (computers, storage, network bandwidth). This paper proposes a new self-recharging virtual currency model as a common medium of exchange in a computational market. The key idea is to recycle currency through the economy automatically while bounding the rate of spending by consumers. Currency budgets may

  7. The pronounced seasonality of global groundwater recharge

    NASA Astrophysics Data System (ADS)

    Jasechko, Scott; Birks, S. Jean; Gleeson, Tom; Wada, Yoshihide; Fawcett, Peter J.; Sharp, Zachary D.; McDonnell, Jeffrey J.; Welker, Jeffrey M.

    2014-11-01

    Groundwater recharged by meteoric water supports human life by providing two billion people with drinking water and by supplying 40% of cropland irrigation. While annual groundwater recharge rates are reported in many studies, fewer studies have explicitly quantified intra-annual (i.e., seasonal) differences in groundwater recharge. Understanding seasonal differences in the fraction of precipitation that recharges aquifers is important for predicting annual recharge groundwater rates under changing seasonal precipitation and evapotranspiration regimes in a warming climate, for accurately interpreting isotopic proxies in paleoclimate records, and for understanding linkages between ecosystem productivity and groundwater recharge. Here we determine seasonal differences in the groundwater recharge ratio, defined here as the ratio of groundwater recharge to precipitation, at 54 globally distributed locations on the basis of 18O/16O and 2H/1H ratios in precipitation and groundwater. Our analysis shows that arid and temperate climates have wintertime groundwater recharge ratios that are consistently higher than summertime groundwater recharge ratios, while tropical groundwater recharge ratios are at a maximum during the wet season. The isotope-based recharge ratio seasonality is consistent with monthly outputs from a global hydrological model (PCR-GLOBWB) for most, but not all locations. The pronounced seasonality in groundwater recharge ratios shown in this study signifies that, from the point of view of predicting future groundwater recharge rates, a unit change in winter (temperate and arid regions) or wet season (tropics) precipitation will result in a greater change to the annual groundwater recharge rate than the same unit change to summer or dry season precipitation.

  8. A Comparison of Trajectory Optimization Methods for the Impulsive Minimum Fuel Rendezvous Problem

    NASA Technical Reports Server (NTRS)

    Hughes, Steven P.; Mailhe, Laurie M.; Guzman, Jose J.

    2002-01-01

    In this paper we present a comparison of optimization approaches to the minimum fuel rendezvous problem. Both indirect and direct methods are compared for a variety of test cases. The indirect approach is based on primer vector theory. The direct approaches are implemented numerically and include Sequential Quadratic Programming (SQP), Quasi-Newton, Simplex, Genetic Algorithms, and Simulated Annealing. Each method is applied to a variety of test cases including, circular to circular coplanar orbits, LEO to GEO, and orbit phasing in highly elliptic orbits. We also compare different constrained optimization routines on complex orbit rendezvous problems with complicated, highly nonlinear constraints.

  9. Nanomaterials for rechargeable lithium batteries.

    PubMed

    Bruce, Peter G; Scrosati, Bruno; Tarascon, Jean-Marie

    2008-01-01

    Energy storage is more important today than at any time in human history. Future generations of rechargeable lithium batteries are required to power portable electronic devices (cellphones, laptop computers etc.), store electricity from renewable sources, and as a vital component in new hybrid electric vehicles. To achieve the increase in energy and power density essential to meet the future challenges of energy storage, new materials chemistry, and especially new nanomaterials chemistry, is essential. We must find ways of synthesizing new nanomaterials with new properties or combinations of properties, for use as electrodes and electrolytes in lithium batteries. Herein we review some of the recent scientific advances in nanomaterials, and especially in nanostructured materials, for rechargeable lithium-ion batteries. PMID:18338357

  10. Electrically rechargeable REDOX flow cell

    NASA Technical Reports Server (NTRS)

    Thaller, L. H. (inventor)

    1976-01-01

    A bulk energy storage system is designed with an electrically rechargeable reduction-oxidation (REDOX) cell divided into two compartments by a membrane, each compartment containing an electrode. An anode fluid is directed through the first compartment at the same time that a cathode fluid is directed through the second compartment. Means are provided for circulating the anode and cathode fluids, and the electrodes are connected to an intermittent or non-continuous electrical source, which when operating, supplies current to a load as well as to the cell to recharge it. Ancillary circuitry is provided for disconnecting the intermittent source from the cell at prescribed times and for circulating the anode and cathode fluids according to desired parameters and conditions.

  11. Improving Spatially Distributed Regional Recharge Estimation

    NASA Astrophysics Data System (ADS)

    Zomlot, Zainab; Batelaan, Okke

    2010-05-01

    Spatial and temporal variability of groundwater recharge are key factors that need to be quantified to determine the sustainability of groundwater resources. In response to the need for better estimates of groundwater recharge the WetSpass spatially distributed water balance model was developed and applied for Flanders. This model aims to simulate long-term average recharge depending on land cover, soil texture, topography and hydrometeorological parameters. The model simulates recharge iteratively connected to a groundwater model, such that the recharge estimate is also influenced by the groundwater depth and vice versa. The application of the model shows that the resulting recharge has a spatial complex pattern, depending to a large extend on the soil texture and land cover. Moreover, shallow groundwater levels in valleys cause negative recharge conditions as a result of evapotranspiration by abundant phreatophytic vegetation. For more dynamic recharge processes the WetSpa spatially distributed rainfall-runoff model can be applied. The aim of this contribution is to present WetSpass-WetSa recharge methodology and to evaluate the simulated spatially distributed recharge for Flanders on basis of baseflow time series of 67 river gauging stations distributed over Flanders.

  12. Iron-Air Rechargeable Battery

    NASA Technical Reports Server (NTRS)

    Narayan, Sri R. (Inventor); Prakash, G.K. Surya (Inventor); Kindler, Andrew (Inventor)

    2014-01-01

    Embodiments include an iron-air rechargeable battery having a composite electrode including an iron electrode and a hydrogen electrode integrated therewith. An air electrode is spaced from the iron electrode and an electrolyte is provided in contact with the air electrode and the iron electrodes. Various additives and catalysts are disclosed with respect to the iron electrode, air electrode, and electrolyte for increasing battery efficiency and cycle life.

  13. Survey of rechargeable battery technology

    SciTech Connect

    Not Available

    1993-07-01

    We have reviewed rechargeable battery technology options for a specialized application in unmanned high altitude aircraft. Consideration was given to all rechargeable battery technologies that are available commercially or might be available in the foreseeable future. The LLNL application was found to impose very demanding performance requirements which cannot be met by existing commercially available battery technologies. The most demanding requirement is for high energy density. The technology that comes closest to providing the LLNL requirements is silver-zinc, although the technology exhibits significant shortfalls in energy density, charge rate capability and cyclability. There is no battery technology available ``off-the-shelf` today that can satisfy the LLNL performance requirements. All rechargeable battery technologies with the possibility of approaching/meeting the energy density requirements were reviewed. Vendor interviews were carried out for all relevant technologies. A large number of rechargeable battery systems have been developed over the years, though a much smaller number have achieved commercial success and general availability. The theoretical energy densities for these systems are summarized. It should be noted that a generally useful ``rule-of-thumb`` is that the ratio of packaged to theoretical energy density has proven to be less than 30%, and generally less than 25%. Data developed for this project confirm the usefulness of the general rule. However, data shown for the silver-zinc (AgZn) system show a greater conversion of theoretical to practical energy density than would be expected due to the very large cell sizes considered and the unusually high density of the active materials.

  14. Charge Characteristics of Rechargeable Batteries

    NASA Astrophysics Data System (ADS)

    Maheswaranathan, Ponn; Kelly, Cormac

    2014-03-01

    Rechargeable batteries play important role in technologies today and they are critical for the future. They are used in many electronic devices and their capabilities need to keep up with the accelerated pace of technology. Efficient energy capture and storage is necessary for the future rechargeable batteries. Charging and discharging characteristics of three popular commercially available re-chargeable batteries (NiCd, NiMH, and Li Ion) are investigated and compared with regular alkaline batteries. Pasco's 850 interface and their voltage & current sensors are used to monitor the current through and the potential difference across the battery. The discharge current and voltage stayed fairly constant until the end, with a slightly larger drop in voltage than current, which is more pronounced in the alkaline batteries. After 25 charge/discharge cycling there is no appreciable loss of charge capacities in the Li Ion battery. Energy densities, cycle characteristics, and memory effects will also be presented. Sponsored by the South Carolina Governor's school for Science and Mathematics under the Summer Program for Research Interns program.

  15. Groundwater recharge and agricultural contamination

    USGS Publications Warehouse

    Böhlke, J.K.

    2002-01-01

    Agriculture has had direct and indirect effects on the rates and compositions of groundwater recharge and aquifer biogeochemistry. Direct effects include dissolution and transport of excess quantities of fertilizers and associated materials and hydrologic alterations related to irrigation and drainage. Some indirect effects include changes in water-rock reactions in soils and aquifers caused by increased concentrations of dissolved oxidants, protons, and major ions. Agrilcultural activities have directly or indirectly affected the concentrations of a large number of inorganic chemicals in groundwater, for example NO3-, N2, Cl, SO42-, H+, P, C, K, Mg, Ca, Sr, Ba, Ra, and As, as well a wide variety of pesticides and other organic compounds. For reactive contaminants like NO3-, a combination of chemical, isotopic, and environmental-tracer analytical approaches might be required to resolve changing inputs from subsequent alterations as causes of concentration gradients in groundwater. Groundwater records derived from multi-component hydrostratigraphic data can be used to quantify recharge rates and residence times of water and dissolved contaminants, document past variations in recharging contaminant loads, and identify natural contaminant-remediation processes. These data indicate that many of the world's surficial aquifers contain transient records of changing agricultural contamination from the last half of the 20th century. The transient agricultural groundwater signal has important implications for long-term trends and spatial heterogeneity in discharge.

  16. Application of wavelet scaling function expansion continuous-energy resonance calculation method to MOX fuel problem

    SciTech Connect

    Yang, W. [Shanghai Nuclear Engineering Research and Design Inst., Hong Cao road 29, Shanghai (China); Dept. of Nuclear Engineering, Xi'an Jiaotong Univ., Xian Ning west road 28, Xi'an, Shaanxi (China); Wu, H.; Cao, L. [Dept. of Nuclear Engineering, Xi'an Jiaotong Univ., Xian Ning west road 28, Xi'an, Shaanxi (China)

    2012-07-01

    More and more MOX fuels are used in all over the world in the past several decades. Compared with UO{sub 2} fuel, it contains some new features. For example, the neutron spectrum is harder and more resonance interference effects within the resonance energy range are introduced because of more resonant nuclides contained in the MOX fuel. In this paper, the wavelets scaling function expansion method is applied to study the resonance behavior of plutonium isotopes within MOX fuel. Wavelets scaling function expansion continuous-energy self-shielding method is developed recently. It has been validated and verified by comparison to Monte Carlo calculations. In this method, the continuous-energy cross-sections are utilized within resonance energy, which means that it's capable to solve problems with serious resonance interference effects without iteration calculations. Therefore, this method adapts to treat the MOX fuel resonance calculation problem natively. Furthermore, plutonium isotopes have fierce oscillations of total cross-section within thermal energy range, especially for {sup 240}Pu and {sup 242}Pu. To take thermal resonance effect of plutonium isotopes into consideration the wavelet scaling function expansion continuous-energy resonance calculation code WAVERESON is enhanced by applying the free gas scattering kernel to obtain the continuous-energy scattering source within thermal energy range (2.1 eV to 4.0 eV) contrasting against the resonance energy range in which the elastic scattering kernel is utilized. Finally, all of the calculation results of WAVERESON are compared with MCNP calculation. (authors)

  17. Advanced materials for electrodes and electrolyte in rechargeable lithium batteries

    Microsoft Academic Search

    Sau yen Chew

    2009-01-01

    The lithium-ion (Li-ion) battery possesses many outstanding advantages over the well known rechargeable battery systems, in particularly higher energy density and longer shelf life, as well as not suffering from the memory effect problems of Ni-MH batteries. Those advantages are making it the greatest energy source of choice for the portable electronic market. Graphite and LiCoO2 are commonly used in

  18. Impacts of Decreasing Recharge Rates on Sustainable Groundwater Management

    Microsoft Academic Search

    Hasan Yazicigil; Koray K. Yilmaz; Burcu Unsal Erdemli; Ozlem Yagbasan

    \\u000a Groundwater is a vital resource for living and food security for at least two billion people worldwide. Ever increasing demand\\u000a on groundwater has led to overexploitation of the aquifers and degradation of groundwater quality. Climate change will exacerbate\\u000a these problems by producing reduced recharge rates in some areas, more reliance on groundwater resources due to decrease in\\u000a reliability of surface

  19. Monitoring Cave Recharge in the Edwards Aquifer Recharge Zone for Natural and Simulated Rainfall Events

    Microsoft Academic Search

    L. Gregory; G. Veni; B. Shade; B. P. Wilcox; C. L. Munster; M. K. Owens

    2005-01-01

    Across semi-arid regions of the world, woody plant encroachment is widespread with potential implications for groundwater recharge and streamflow. In an effort to better understand the interactions between woody plants and recharge, we are monitoring drip rates in shallow caves in the Edwards Aquifer recharge zone of Central Texas. The surface is covered by a dense stand of ashe juniper

  20. Improved Carbon Anodes For Rechargeable Lithium Cells

    NASA Technical Reports Server (NTRS)

    Huang, Chen-Kuo; Surampudi, Subbarao; Attia, Alan; Halpert, Gerald

    1994-01-01

    Carbon anodes for rechargeable lithium cells improved by choosing binder contents and fabrication conditions to achieve maximum porosity, uniform loading, and maximum reversible lithium capacity. Stacking electrodes under pressure during assembly of cells increases cyclability of lithium. Rechargeable, high-energy-density lithium cells containing improved carbon anodes find use in spacecraft, military, communications, automotive, and other demanding applications.

  1. Quantifying Mountain Front Recharge Using Isotopic Tracers

    Microsoft Academic Search

    A. K. Wahi; B. Ekwurzel; J. F. Hogan; C. J. Eastoe; M. N. Baillie

    2005-01-01

    To improve our conceptual and quantitative understanding of mountain-front\\/mountain-block recharge (MFR) associated with the Huachuca Mountains of the Upper San Pedro River Basin in Arizona, we employed a suite of geochemical measurements including isotopic tracers and noble gases. MFR is frequently the dominant source of recharge to alluvial basins in the semiarid Basin and Range province. It consists of mountain

  2. INTRODUCTION TO ARTIFICIAL GROUND-WATER RECHARGE

    EPA Science Inventory

    Artificial ground-water recharge has been practiced for scores of years throughout the world. The purpose of artificial recharge is to increase the rate at which water infiltrates the land surface in order to supplement the quantity of ground water in storage. A variety of rechar...

  3. Recharge at the Hanford Site: Status report

    SciTech Connect

    Gee, G.W.

    1987-11-01

    A variety of field programs designed to evaluate recharge and other water balance components including precipitation, infiltration, evaporation, and water storage changes, have been carried out at the Hanford Site since 1970. Data from these programs have indicated that a wide range of recharge rates can occur depending upon specific site conditions. Present evidence suggests that minimum recharge occurs where soils are fine-textured and surfaces are vegetated with deep-rooted plants. Maximum recharge occurs where coarse soils or gravels exist at the surface and soils are kept bare. Recharge can occur in areas where shallow-rooted plants dominate the surface, particularly where soils are coarse-textured. Recharge estimates have been made for the site using simulation models. A US Geological Survey model that attempts to account for climate variability, soil storage parameters, and plant factors has calculated recharge values ranging from near zero to an average of about 1 cm/yr for the Hanford Site. UNSAT-H, a deterministic model developed for the site, appears to be the best code available for estimating recharge on a site-specific basis. Appendix I contains precipitation data from January 1979 to June 1987. 42 refs., 11 figs., 11 tabs.

  4. 8/10/12 Bureaucracy fuels China's safe water problems | Eco-Business.com 1/2www.eco-business.com/news/bureaucracy-fuels-chinas-safe-water-problems/

    E-print Network

    8/10/12 Bureaucracy fuels China's safe water problems | Eco-Business.com 1/2www.eco-business.com/news/bureaucracy | EVENTS | JOBS | DIRECTORY | PROJECTS | RESOURCES Search News Bureaucracy fuels China's safe water planning, water security The kind of top-down bureaucracy that can discourage communication and hobble some

  5. Comparison Study of SPEA2+, SPEA2, and NSGA-II in Diesel Engine Emissions and Fuel Economy Problem

    E-print Network

    Coello, Carlos A. Coello

    Comparison Study of SPEA2+, SPEA2, and NSGA-II in Diesel Engine Emissions and Fuel Economy Problem@mail.doshisha.ac.jp Abstract- Recently, the technology that can control NOx and Soot values of diesel engines by changing between fuel economy and NOx values. Therefore, the diesel engines that can change their characteristics

  6. Rechargeable lithium-ion cell

    DOEpatents

    Bechtold, Dieter (Bad Vilbel, DE); Bartke, Dietrich (Kelkheim, DE); Kramer, Peter (Konigstein, DE); Kretzschmar, Reiner (Kelkheim, DE); Vollbert, Jurgen (Hattersheim, DE)

    1999-01-01

    The invention relates to a rechargeable lithium-ion cell, a method for its manufacture, and its application. The cell is distinguished by the fact that it has a metallic housing (21) which is electrically insulated internally by two half shells (15), which cover electrode plates (8) and main output tabs (7) and are composed of a non-conductive material, where the metallic housing is electrically insulated externally by means of an insulation coating. The cell also has a bursting membrane (4) which, in its normal position, is located above the electrolyte level of the cell (1). In addition, the cell has a twisting protection (6) which extends over the entire surface of the cover (2) and provides centering and assembly functions for the electrode package, which comprises the electrode plates (8).

  7. Water table fluctuation due to transient recharge in a 2-D aquifer system with inclined base

    Microsoft Academic Search

    D. V. Ramana; S. N. Rai; R. N. Singh

    1995-01-01

    Recharging of aquifers due to irrigation, seepage from canal beds and other sources leads to the growth of water table near to the ground surface causing problems like water logging and increase of salinity in top soils in many regions of the world. This problem can be alleviated if proper knowledge of the spatio — temporal variation of the water

  8. Pulverized fuel ash products solve the sewage sludge problems of the wastewater industry

    SciTech Connect

    Dirk, G. [Rhenipal UK Ltd., Birkenhead (United Kingdom)] [Rhenipal UK Ltd., Birkenhead (United Kingdom)

    1996-12-31

    Sewage sludge recycling has become one of the predominant problems of the water industry. Not all types of sewage sludges are able to be recycled to farm land or into composting processes. Pulverized fuel ash is used as a major ingredient in a product called Rhenipal which is used to stabilize sewage sludge for recycling into a material for land reclamation, as a soil conditioner, as cover material for landfill and as a landfill engineering material. This article deals with the results achieved when applying rhenipal in a post-stabilization process to prepare landfill engineering material. The process is currently developed further and can be operated in a pre-stabilization mode, which will further improve the economical results shown for the post-stabilization method in this paper.

  9. Micro Windmills to Recharge Cell Leave a reply

    E-print Network

    Chiao, Jung-Chih

    Micro Windmills to Recharge Cell Phones Leave a reply The Windmill in Action At the University Page 1 of 2Micro Windmills to Recharge Cell Phones | MADE 2/3/2014http://themadeblog.com/micro-windmills-to-recharge-cell-phones in Architecture, Design and tagged Cell Phone, Design, JC Chiao, MADE BLOG, Micro Windmills, New, News, Recharge

  10. Groundwater recharge estimation and regionalization: the Great Bend Prairie of central Kansas and its recharge statistics

    Microsoft Academic Search

    Marios Sophocleous

    1992-01-01

    Sophocleous, M., 1992. Groundwater recharge estimation and regionalization: the Great Bend Prairie of central Kansas and its recharge statistics. J. Hydrol., 137: 113-140. The results of a 6 year recharge st,dy in the Great Bend Prairie of t:entral Kansas are statistically analyzed to regionalize the limited number of site-specific but year-round measurements. Emphasis is placed on easily measured parameters and

  11. Issues and challenges facing rechargeable lithium batteries

    Microsoft Academic Search

    J.-M. Tarascon; M. Armand

    2001-01-01

    Technological improvements in rechargeable solid-state batteries are being driven by an ever-increasing demand for portable electronic devices. Lithium-ion batteries are the systems of choice, offering high energy density, flexible and lightweight design, and longer lifespan than comparable battery technologies. We present a brief historical review of the development of lithium-based rechargeable batteries, highlight ongoing research strategies, and discuss the challenges

  12. Artificial recharge of groundwater: hydrogeology and engineering

    NASA Astrophysics Data System (ADS)

    Bouwer, Herman

    2002-02-01

    Artificial recharge of groundwater is achieved by putting surface water in basins, furrows, ditches, or other facilities where it infiltrates into the soil and moves downward to recharge aquifers. Artificial recharge is increasingly used for short- or long-term underground storage, where it has several advantages over surface storage, and in water reuse. Artificial recharge requires permeable surface soils. Where these are not available, trenches or shafts in the unsaturated zone can be used, or water can be directly injected into aquifers through wells. To design a system for artificial recharge of groundwater, infiltration rates of the soil must be determined and the unsaturated zone between land surface and the aquifer must be checked for adequate permeability and absence of polluted areas. The aquifer should be sufficiently transmissive to avoid excessive buildup of groundwater mounds. Knowledge of these conditions requires field investigations and, if no fatal flaws are detected, test basins to predict system performance. Water-quality issues must be evaluated, especially with respect to formation of clogging layers on basin bottoms or other infiltration surfaces, and to geochemical reactions in the aquifer. Clogging layers are managed by desilting or other pretreatment of the water, and by remedial techniques in the infiltration system, such as drying, scraping, disking, ripping, or other tillage. Recharge wells should be pumped periodically to backwash clogging layers. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s10040-001-0182-4.

  13. Proposed artificial recharge studies in northern Qatar

    USGS Publications Warehouse

    Kimrey, J.O.

    1985-01-01

    The aquifer system in northern Qatar comprises a water-table aquifer in the Rus Formation which is separated by an aquitard from a partially confined aquifer in the top of the overlying Umm er Radhuma Formation. These two aquifers are composed of limestone and dolomite of Eocene and Paleocene age and contain a fragile lens of freshwater which is heavily exploited as a source of water for agricultural irrigation. Net withdrawals are greatly in excess of total recharge, and quality of ground water is declining. Use of desalinated seawater for artificial recharge has been proposed for the area. Artificial recharge, on a large scale, could stabilize the decline in ground-water quality while allowing increased withdrawals for irrigation. The proposal appears technically feasible. Recharge should be by injection to the Umm er Radhuma aquifer whose average transmissivity is about 2,000 meters squared per day (as compared to an average of about 200 meters squared per day for the Rus aquifer). Implementation of artificial recharge should be preceded by a hydrogeologic appraisal. These studies should include test drilling, conventional aquifer tests, and recharge-recovery tests at four sites in northern Qatar. (USGS)

  14. Analysis of regenerative fuel cells

    Microsoft Academic Search

    S. Gross

    1982-01-01

    The concept of a rechargeable fuel cell (RFC) system is considered. A newer type of rechargeable battery, the nickel hydrogen (Ni-H2) battery, is also evaluated. A review was made of past studies which showed large variations in weight, cost, and efficiency. Hydrogen-bromine and hydrogen-chlorine regenerable fuel cells were studied, and were found to have a potential for higher energy storage

  15. A Comparison of Trajectory Optimization Methods for the Impulsive Minimum Fuel Rendezvous Problem

    NASA Technical Reports Server (NTRS)

    Hughes, Steven P.; Mailhe, Laurie M.; Guzman, Jose J.

    2003-01-01

    In this paper we present, a comparison of trajectory optimization approaches for the minimum fuel rendezvous problem. Both indirect and direct methods are compared for a variety of test cases. The indirect approach is based on primer vector theory. The direct approaches are implemented numerically and include Sequential Quadratic Programming (SQP). Quasi- Newton and Nelder-Meade Simplex. Several cost function parameterizations are considered for the direct approach. We choose one direct approach that appears to be the most flexible. Both the direct and indirect methods are applied to a variety of test cases which are chosen to demonstrate the performance of each method in different flight regimes. The first test case is a simple circular-to-circular coplanar rendezvous. The second test case is an elliptic-to-elliptic line of apsides rotation. The final test case is an orbit phasing maneuver sequence in a highly elliptic orbit. For each test case we present a comparison of the performance of all methods we consider in this paper.

  16. Fuel cells provide a revenue-generating solution to power quality problems

    SciTech Connect

    King, J.M. Jr.

    1996-03-01

    Electric power quality and reliability are becoming increasingly important as computers and microprocessors assume a larger role in commercial, health care and industrial buildings and processes. At the same time, constraints on transmission and distribution of power from central stations are making local areas vulnerable to low voltage, load addition limitations, power quality and power reliability problems. Many customers currently utilize some form of premium power in the form of standby generators and/or UPS systems. These include customers where continuous power is required because of health and safety or security reasons (hospitals, nursing homes, places of public assembly, air traffic control, military installations, telecommunications, etc.) These also include customers with industrial or commercial processes which can`t tolerance an interruption of power because of product loss or equipment damage. The paper discusses the use of the PC25 fuel cell power plant for backup and parallel power supplies for critical industrial applications. Several PC25 installations are described: the use of propane in a PC25; the use by rural cooperatives; and a demonstration of PC25 technology using landfill gas.

  17. GPU Based General-Purpose Parallel computing to Solve Nuclear Reactor In-Core fuel Management Design and Operation Problem

    SciTech Connect

    Prayudhatama, D.; Waris, A.; Kurniasih, N.; Kurniadi, R. [Bosscha Laboratory, Department of Physics, Nuclear Physics and Biophysics Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung (Indonesia)

    2010-06-22

    In-core fuel management study is a crucial activity in nuclear power plant design and operation. Its common problem is to find an optimum arrangement of fuel assemblies inside the reactor core. Main objective for this activity is to reduce the cost of generating electricity, which can be done by altering several physical properties of the nuclear reactor without violating any of the constraints imposed by operational and safety considerations. This research try to address the problem of nuclear fuel arrangement problem, which is, leads to the multi-objective optimization problem. However, the calculation of the reactor core physical properties itself is a heavy computation, which became obstacle in solving the optimization problem by using genetic algorithm optimization.This research tends to address that problem by using the emerging General Purpose Computation on Graphics Processing Units (GPGPU) techniques implemented by C language for CUDA (Compute Unified Device Architecture) parallel programming. By using this parallel programming technique, we develop parallelized nuclear reactor fitness calculation, which is involving numerical finite difference computation. This paper describes current prototype of the parallel algorithm code we have developed on CUDA, that performs one hundreds finite difference calculation for nuclear reactor fitness evaluation in parallel by using GPU G9 Hardware Series developed by NVIDIA.

  18. Sources of recharge at Abu Delaig, Sudan

    NASA Astrophysics Data System (ADS)

    Edmunds, W. M.; Darling, W. G.; Kinniburgh, D. G.; Kotoub, S.; Mahgoub, S.

    1992-02-01

    Various components of the water cycle in and around Abu Delaig, a small town in a semiarid region of Sudan, have been investigated with geochemical and isotopic techniques to determine the sources of groundwater recharge. Rain samples (total deposition during storms) contain significant concentrations of dissolved solids for a continental site (mean 4.6 mgl -1 for 1982-1985). The heaviest rains important for recharge tend to have the lowest chlorinities, and are also the most negative isotopically. Wadi floods generally have lower chlorinity than the rainfall indicating the proportionally lower amounts of dust in the more intense rainfall events. Shallow ground waters at Abu Delaig have relatively evolved compositions (higher Mg/Ca ratios) compared with rainfall and wadi floods, yet they also contain tritium and retain isotopic signatures similar to the local rainfall. They also have a distinctive chemistry compared with the deeper ground waters in the region and recharge from the former to the latter is considered to be insignificant. Ground waters in the unsaturated zone are saline and have isotopic compositions highly enriched in heavy isotopes compared with rainfall, indicating strong evaporation. The chloride balance indicates that mean recharge rates are 0.2-1.3 mm year -1 through the interfluve areas. It is concluded that the only significant replenishable resources at Abu Delaig are from wadi recharge during floods and that direct regional recharge is insignificant. Fluctuations in the water table, however, lead to solutes from the lower unsaturated zone contributing to the chemistry of the shallow ground waters. Elsewhere it is possible that wadi recharge may be a possible route for deeper replenishment, but this needs to be demonstrated by dedicated experiments.

  19. A critical assessment of simple recharge models: application to the UK Chalk

    NASA Astrophysics Data System (ADS)

    Ireson, A. M.; Butler, A. P.

    2013-06-01

    Quantification of the timing and magnitude of point-scale groundwater recharge is challenging, but possible at specific sites given sufficient high spatial and temporal resolution field observations, and a suitable physically based model. Such models are generally too computationally intensive and have too many unknown parameters to be practically applicable within distributed, larger-scale hydrological or groundwater models. This motivates the need for simpler recharge models, which are widely used within groundwater models. However, it is important that these models are able to capture adequately the unsaturated zone flow processes. We perform an inter-comparison of recharge simulated by a detailed physically based model and a simple recharge model, with both models applied to a field site in the fractured porous Chalk in the UK. Flow processes are simulated convincingly using a dual permeability, equivalent continuum, vertically heterogeneous, Richards' equation model, applied to a 2-D hillslope transect. A simple conventional recharge model was then calibrated to reproduce the water table response simulated by the physically based model. The performance in reproducing the water table was surprisingly good, given the known discrepancies between the actual processes and the model representation. However, comparisons of recharge fluxes simulated by each model highlighted problems with the process representations in the simple model. Specifically, bypass flow events during the summer were compensating for recharge that should have come from slow, continual drainage of the unsaturated zone. Such a model may still be useful for assessment of groundwater resources on a monthly basis, under non-extreme climatic conditions. However, under extreme wet or dry conditions, or under a changed climate the predictive capacity of such models is likely to be inadequate.

  20. Estimated recharge rates at the Hanford Site

    SciTech Connect

    Fayer, M.J.; Walters, T.B.

    1995-02-01

    The Ground-Water Surveillance Project monitors the distribution of contaminants in ground water at the Hanford Site for the U.S. Department of Energy. A subtask called {open_quotes}Water Budget at Hanford{close_quotes} was initiated in FY 1994. The objective of this subtask was to produce a defensible map of estimated recharge rates across the Hanford Site. Methods that have been used to estimate recharge rates at the Hanford Site include measurements (of drainage, water contents, and tracers) and computer modeling. For the simulations of 12 soil-vegetation combinations, the annual rates varied from 0.05 mm/yr for the Ephrata sandy loam with bunchgrass to 85.2 mm/yr for the same soil without vegetation. Water content data from the Grass Site in the 300 Area indicated that annual rates varied from 3.0 to 143.5 mm/yr during an 8-year period. The annual volume of estimated recharge was calculated to be 8.47 {times} 10{sup 9} L for the potential future Hanford Site (i.e., the portion of the current Site bounded by Highway 240 and the Columbia River). This total volume is similar to earlier estimates of natural recharge and is 2 to 10x higher than estimates of runoff and ground-water flow from higher elevations. Not only is the volume of natural recharge significant in comparison to other ground-water inputs, the distribution of estimated recharge is highly skewed to the disturbed sandy soils (i.e., the 200 Areas, where most contaminants originate). The lack of good estimates of the means and variances of the supporting data (i.e., the soil map, the vegetation/land use map, the model parameters) translates into large uncertainties in the recharge estimates. When combined, the significant quantity of estimated recharge, its high sensitivity to disturbance, and the unquantified uncertainty of the data and model parameters suggest that the defensibility of the recharge estimates should be improved.

  1. Modeling Recharge - can it be Done?

    NASA Astrophysics Data System (ADS)

    Verburg, K.; Bond, W. J.; Smith, C. J.; Dunin, F. X.

    2001-12-01

    In sub-humid areas where rainfall is relatively low and sporadic, recharge (defined as water movement beyond the active root zone) is the small difference between the much larger numbers rainfall and evapotranspiration. It is very difficult to measure and often modeling is resorted to instead. But is modeling this small number any less difficult than measurement? In Australia there is considerable debate over the magnitude of recharge under different agricultural systems because of its contribution to rising saline groundwater levels following the clearing of native vegetation in the last 100 years. Hence the adequacy of measured and modeled estimates of recharge is under close scrutiny. Results will be presented for the water balance of an intensively monitored 8 year sequence of crops and pastures. Measurements included meteorological inputs, evapotranspiration measured with a pair of weighing lysimeters, and soil water content was measured with TDR and neutron moisture meter. Recharge was estimated from the percolate removed from the lysimeters as well as, when conditions were suitable, from soil water measurements and combined soil water and evapotranspiration measurements. This data was simulated using a comprehensive soil-plant-atmosphere model (APSIM). Comparison with field measurements shows that the recharge can be simulated with an accuracy similar to that with which it can be measured. However, is either sufficiently accurate for the applications for which they are required?

  2. Stability and error analysis of the polarization estimation inverse problem for microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Renaut, R. A.; Baker, R.; Horst, M.; Johnson, C.; Nasir, D.

    2013-04-01

    Determining parameters which describe the performance of a microbial fuel cell requires the solution of an inverse problem. Two formulations have been presented in the literature: a convolutional approach or a direct quadrature approach. A complete study and analysis of the direct quadrature method, which leads to two systems for the unknown signal given measured complex data, known as the distribution function of relaxation times, is presented. A theoretical analysis justifies the minimal range of integration that is appropriate for the quadrature and suggests that the systems should be combined giving an overdetermined system that is not well posed but not as ill-posed as either system considered separately. All measures of ill-posedness support using the combined data when the level of error in both components of the complex measurements is equivalent. Tikhonov regularization for the filtered singular value and truncated singular value decomposition are used to find solutions of the underlying model system. Given such solutions the application requires the determination of the model parameters that define the signal, among which are the location and peaks of the individual processes of the cell. A nonlinear data fitting approach is presented which consistently estimates these parameters. Simulations support the use of the combined systems for finding the underlying distribution function of relaxation times and the subsequent nonlinear data fitting to these curves. The approach is also illustrated for measured practical data, demonstrating that without the theoretical analysis incorrect conclusions on the underlying physical system would arise. This work justifies the use of Tikhonov regularization combined with nonlinear data fitting for finding reliable solutions for the specific model, when the signal is comprised of a mixture of signals from a small number of processes.

  3. Derived Operating Rules for Allocating Recharges and Withdrawals among Unconnected Aquifers

    E-print Network

    Pasternack, Gregory B.

    is moving under- ground. In California, major urban water providers now contract with nearby and distant engineering problems for water supply and drought response. Even when surplus surface water supplies or target inflows. During droughts, demand is relatively constant, and natural recharge is likely small or trivial

  4. Impacts of vegetation change on groundwater recharge

    NASA Astrophysics Data System (ADS)

    Bond, W. J.; Verburg, K.; Smith, C. J.

    2003-12-01

    Vegetation change is the accepted cause of increasing river salt concentrations and the salinisation of millions of hectares of farm land in Australia. Replacement of perennial native vegetation by annual crops and pastures following European settlement has altered the water balance causing increased groundwater recharge and mobilising the naturally saline groundwater. The Redesigning Agriculture for Australian Landscapes Program, of which the work described here is a part, was established to develop agricultural practices that are more attuned to the delicate water balance described above. Results of field measurements will be presented that contrast the water balance characteristics of native vegetation with those of conventional agricultural plants, and indicate the functional characteristics required of new agricultural practices to reduce recharge. New agricultural practices may comprise different management of current crops and pastures, or may involve introducing totally new species. In either case, long-term testing is required to examine their impact on recharge over a long enough climate record to encompass the natural variability of rainfall that is characteristic of most Australian farming regions. Field experimentation therefore needs to be complemented and extended by computer simulation. This requires a modelling approach that is more robust than conventional crop modelling because (a) it needs to be sensitive enough to predict small changes in the residual recharge term, (b) it needs to be able to simulate a variety of vegetation in different sequences, (c) it needs to be able to simulate continuously for several decades of input data, and (d) it therefore needs to be able to simulate the period between crops, which often has a critical impact on recharge. The APSIM simulation framework will be used to illustrate these issues and to explore the effect of different vegetation combinations on recharge.

  5. Quantifying Mountain Front Recharge Using Isotopic Tracers

    NASA Astrophysics Data System (ADS)

    Wahi, A. K.; Ekwurzel, B.; Hogan, J. F.; Eastoe, C. J.; Baillie, M. N.

    2005-05-01

    To improve our conceptual and quantitative understanding of mountain-front/mountain-block recharge (MFR) associated with the Huachuca Mountains of the Upper San Pedro River Basin in Arizona, we employed a suite of geochemical measurements including isotopic tracers and noble gases. MFR is frequently the dominant source of recharge to alluvial basins in the semiarid Basin and Range province. It consists of mountain runoff that infiltrates at the mountain front (mountain-front recharge), and percolation through the mountain bedrock that reaches the basin via the movement of deep groundwater (mountain-block recharge). The rate of MFR can be estimated from a water balance, a Darcy's law analysis, or inverse modeling of groundwater processes. Despite the large volume of research on water resources in the basin and the critical importance of MFR to the water budget, the best estimates of MFR obtained using these methods may have errors as large as 100%. We find that geochemical tracers address mechanistic questions regarding recharge seasonality, location, and rates as well as addressing groundwater flowpaths and residence times. The gradient of stable isotopes of hydrogen and oxygen in groundwater with elevation mirrors that of regional precipitation, providing a constraint on the location and seasonality of recharge. Stable isotopic signatures indicate that MFR is dominated by winter precipitation but has 1/3 or more contribution from monsoon precipitation. Detectable tritium and 14C values greater than 100 pMC for springs, shallow groundwater in mountain canyons, and from wells along the mountain front indicate decade-scale residence times. Away from the mountain front 14C values rapidly decrease, reaching 12.3±0.2 pMC near the river. This suggests total basin residence times greater than 10,000 years, consistent with past measurements. Ongoing analysis of noble gas concentrations will provide an indication of recharge conditions. The solubility of noble gases in water depends on temperature and pressure; thus, noble gas concentrations provide a means to distinguish water samples recharged at different elevations.

  6. Global-scale modeling of groundwater recharge

    NASA Astrophysics Data System (ADS)

    Döll, P.; Fiedler, K.

    2008-05-01

    Long-term average groundwater recharge, which is equivalent to renewable groundwater resources, is the major limiting factor for the sustainable use of groundwater. Compared to surface water resources, groundwater resources are more protected from pollution, and their use is less restricted by seasonal and inter-annual flow variations. To support water management in a globalized world, it is necessary to estimate groundwater recharge at the global scale. Here, we present a best estimate of global-scale long-term average diffuse groundwater recharge (i.e. renewable groundwater resources) that has been calculated by the most recent version of the WaterGAP Global Hydrology Model WGHM (spatial resolution of 0.5° by 0.5°, daily time steps). The estimate was obtained using two state-of-the-art global data sets of gridded observed precipitation that we corrected for measurement errors, which also allowed to quantify the uncertainty due to these equally uncertain data sets. The standard WGHM groundwater recharge algorithm was modified for semi-arid and arid regions, based on independent estimates of diffuse groundwater recharge, which lead to an unbiased estimation of groundwater recharge in these regions. WGHM was tuned against observed long-term average river discharge at 1235 gauging stations by adjusting, individually for each basin, the partitioning of precipitation into evapotranspiration and total runoff. We estimate that global groundwater recharge was 12 666 km3/yr for the climate normal 1961-1990, i.e. 32% of total renewable water resources. In semi-arid and arid regions, mountainous regions, permafrost regions and in the Asian Monsoon region, groundwater recharge accounts for a lower fraction of total runoff, which makes these regions particularly vulnerable to seasonal and inter-annual precipitation variability and water pollution. Average per-capita renewable groundwater resources of countries vary between 8 m3/(capita yr) for Egypt to more than 1 million m3/(capita yr) for the Falkland Islands, the global average in the year 2000 being 2091 m3/(capita yr). Regarding the uncertainty of estimated groundwater resources due to the two precipitation data sets, deviation from the mean is 1.1% for the global value, and less than 1% for 50 out of the 165 countries considered, between 1 and 5% for 62, between 5 and 20% for 43 and between 20 and 80% for 10 countries. Deviations at the grid scale can be much larger, ranging between 0 and 186 mm/yr.

  7. Global-scale modeling of groundwater recharge

    NASA Astrophysics Data System (ADS)

    Döll, P.; Fiedler, K.

    2007-11-01

    Long-term average groundwater recharge, which is equivalent to renewable groundwater resources, is the major limiting factor for the sustainable use of groundwater. Compared to surface water resources, groundwater resources are more protected from pollution, and their use is less restricted by seasonal and inter-annual flow variations. To support water management in a globalized world, it is necessary to estimate groundwater recharge at the global scale. Here, we present a best estimate of global-scale long-term average diffuse groundwater recharge (i.e. renewable groundwater resources) that has been calculated by the most recent version of the WaterGAP Global Hydrology Model WGHM (spatial resolution of 0.5° by 0.5°, daily time steps). The estimate was obtained using two state-of-the art global data sets of gridded observed precipitation that we corrected for measurement errors, which also allowed to quantify the uncertainty due to these equally uncertain data sets. The standard WGHM groundwater recharge algorithm was modified for semi-arid and arid regions, based on independent estimates of diffuse groundwater recharge, which lead to an unbiased estimation of groundwater recharge in these regions. WGHM was tuned against observed long-term average river discharge at 1235 gauging stations by adjusting, individually for each basin, the partitioning of precipitation into evapotranspiration and total runoff. We estimate that global groundwater recharge was 12 666 km3/yr for the climate normal 1961-1990, i.e. 32% of total renewable water resources. In semi-arid and arid regions, mountainous regions, permafrost regions and in the Asian Monsoon region, groundwater recharge accounts for a lower fraction of total runoff, which makes these regions particularly vulnerable to seasonal and inter-annual precipitation variability and water pollution. Average per-capita renewable groundwater resources of countries vary between 8 m3/(capita yr) for Egypt to more than 1 million m3/(capita yr) for the Falkland Islands, the global average in the year 2000 being 2091 m3/(capita yr). Regarding the uncertainty of estimated groundwater resources due to the two precipitation data sets, deviation from the mean is less than 1% for 50 out of the 165 countries considered, between 1 and 5% for 62, between 5 and 20% for 43 and between 20 and 80% for 10 countries. Deviations at the grid scale can be much larger, ranging between 0 and 186 mm/yr.

  8. Improved Separators For Rechargeable Lithium Cells

    NASA Technical Reports Server (NTRS)

    Shen, David; Surampudi, Subbarao; Huang, Chen-Kuo; Halpert, Gerald

    1994-01-01

    Improved pairs of separators proposed for use in rechargeable lithium cells operating at ambient temperature. Block growth of lithium dendrites and help prevent short circuits. Each cell contains one separator made of microporous polypropylene placed next to anode, and one separator made of microporous polytetrafluoroethylene (PTFE) next to cathode. Separators increase cycle lives of secondary lithium cells. Cells to which concept applicable those of Li/TiS(2), Li/NbSe(3), Li/CoO(2), Li/MoS(2), Li/VO(x), and Li/MnO(2) chemical systems. Advantageous in spacecraft, military, communications, automotive, and other applications in which high energy density and rechargeability needed.

  9. Control circuit for a solar-powered rechargeable power source and load

    Microsoft Academic Search

    R. W. Janda; J. L. Douglas; E. F. Jr. Condon

    1993-01-01

    A solar rechargeable apparatus is described comprising: a rechargeable power source; a solar panel connected to the rechargeable power source for supplying a charging current to the rechargeable power source; a device connected between the rechargeable power source and the solar panel to prevent discharge of current from the rechargeable power source to the solar panel; a load; and a

  10. Rechargeable battery and electrical circuit for charging thereof

    Microsoft Academic Search

    Toops

    1987-01-01

    This patent describes a nickel-cadmium rechargeable cell for use in an energy-using device having at least one charging terminal contact for recharging the cell. The energy-using device adapted to alternately receive either a standard cylindrical AA, AAA, C or D size non-rechargeable cell has a pair of power terminal contacts spaced apart by a standard distance. The rechargeable cell comprises:

  11. Seismicity induced by seasonal groundwater recharge at Mt. Hood, Oregon

    Microsoft Academic Search

    Martin O. Saar; Michael Manga

    2003-01-01

    Groundwater recharge at Mt. Hood, Oregon, is dominated by spring snow melt which provides a natural large-amplitude and narrow-width pore-fluid pressure signal. Time delays between this seasonal groundwater recharge and seismicity triggered by groundwater recharge can thus be used to estimate large-scale hydraulic diffusivities and the state of stress in the crust. We approximate seasonal variations in groundwater recharge with

  12. Expanded use of fossil fuels by the U. S. and the global carbon dioxide problem

    Microsoft Academic Search

    W. R. Emanuel; J. S. Olson; G. G. Killough

    1980-01-01

    Continued combustion of fossil fuels contributes to a steady increase of carbon dioxide concentration in the atmosphere. Projecting present increases in rates of fossil-fuel utilization, a doubling of COâ concentration in the atmosphere may be expected within the next 75 years. Based on preliminary calculations, coal utilization by the U.S. to the year 2020 accounts for between 9 and 14%

  13. Rechargeable solid polymer electrolyte battery cell

    DOEpatents

    Skotheim, Terji (East Patchoque, NY)

    1985-01-01

    A rechargeable battery cell comprising first and second electrodes sandwiching a solid polymer electrolyte comprising a layer of a polymer blend of a highly conductive polymer and a solid polymer electrolyte adjacent said polymer blend and a layer of dry solid polymer electrolyte adjacent said layer of polymer blend and said second electrode.

  14. Alloys of clathrate allotropes for rechargeable batteries

    DOEpatents

    Chan, Candace K; Miller, Michael A; Chan, Kwai S

    2014-12-09

    The present disclosure is directed at an electrode for a battery wherein the electrode comprises clathrate alloys of silicon, germanium or tin. In method form, the present disclosure is directed at methods of forming clathrate alloys of silicon, germanium or tin which methods lead to the formation of empty cage structures suitable for use as electrodes in rechargeable type batteries.

  15. Prototype systems for rechargeable magnesium batteries

    Microsoft Academic Search

    D. Aurbach; Z. Lu; A. Schechter; Y. Gofer; H. Gizbar; R. Turgeman; Y. Cohen; M. Moshkovich; E. Levi

    2000-01-01

    The thermodynamic properties of magnesium make it a natural choice for use as an anode material in rechargeable batteries, because it may provide a considerably higher energy density than the commonly used lead-acid and nickel-cadmium systems. Moreover, in contrast to lead and cadmium, magnesium is inexpensive, environmentally friendly and safe to handle. But the development of Mg batteries has been

  16. REUSE OF MUNICIPAL WASTEWATER FOR GROUNDWATER RECHARGE

    EPA Science Inventory

    A survey of groundwater recharge operations with municipal wastewater effluent was conducted. It was found that this activity is being practiced at 10 sites in the U.S. with a total capacity of 77 MGD. The most successful employ percolation with alternate flooding and drying cycl...

  17. High power rechargeable batteries Paul V. Braun

    E-print Network

    Braun, Paul

    emerging concepts in high power batteries, with a particular focus on Li-ion based chemistries. Ó 2012 storage Secondary batteries High energy density High power density Lithium ion battery 3D batteryHigh power rechargeable batteries Paul V. Braun , Jiung Cho, James H. Pikul, William P. King

  18. Design considerations for rechargeable lithium batteries

    NASA Technical Reports Server (NTRS)

    Shen, D. H.; Huang, C.-K.; Davies, E.; Perrone, D.; Surampudi, S.; Halpert, Gerald

    1993-01-01

    Viewgraphs of a discussion of design considerations for rechargable lithium batteries. The objective is to determine the influence of cell design parameters on the performance of Li-TiS2 cells. Topics covered include cell baseline design and testing, cell design and testing, cell design parameters studies, and cell cycling performance.

  19. Focused Recharge in a Theoretical Raingarden

    Microsoft Academic Search

    A. R. Dussaillant; K. W. Potter; C. Wu

    2001-01-01

    Traditional stormwater management, which relies heavily on detention, does not mitigate groundwater depletion resulting from groundwater pumping and loss of groundwater recharge. In recent years there has been increasing interest in the use of practices, such as raingardens, that encourage infiltration of stormwater as a means of mitigating groundwater impacts. These can be particularly effective when infiltration is focused in

  20. Anode for rechargeable ambient temperature lithium cells

    NASA Technical Reports Server (NTRS)

    Huang, Chen-Kuo (inventor); Surampudi, Subbarao (inventor); Attia, Alan I. (inventor); Halpert, Gerald (inventor)

    1994-01-01

    An ambient room temperature, high density, rechargeable lithium battery includes a Li(x)Mg2Si negative anode which intercalates lithium to form a single crystalline phase when x is up to 1.0 and an amorphous phase when x is from 1 to 2.0. The electrode has good reversibility and mechanical strength after cycling.

  1. A parallel multi-domain solution methodology applied to nonlinear thermal transport problems in nuclear fuel pins

    NASA Astrophysics Data System (ADS)

    Philip, Bobby; Berrill, Mark A.; Allu, Srikanth; Hamilton, Steven P.; Sampath, Rahul S.; Clarno, Kevin T.; Dilts, Gary A.

    2015-04-01

    This paper describes an efficient and nonlinearly consistent parallel solution methodology for solving coupled nonlinear thermal transport problems that occur in nuclear reactor applications over hundreds of individual 3D physical subdomains. Efficiency is obtained by leveraging knowledge of the physical domains, the physics on individual domains, and the couplings between them for preconditioning within a Jacobian Free Newton Krylov method. Details of the computational infrastructure that enabled this work, namely the open source Advanced Multi-Physics (AMP) package developed by the authors is described. Details of verification and validation experiments, and parallel performance analysis in weak and strong scaling studies demonstrating the achieved efficiency of the algorithm are presented. Furthermore, numerical experiments demonstrate that the preconditioner developed is independent of the number of fuel subdomains in a fuel rod, which is particularly important when simulating different types of fuel rods. Finally, we demonstrate the power of the coupling methodology by considering problems with couplings between surface and volume physics and coupling of nonlinear thermal transport in fuel rods to an external radiation transport code.

  2. A Parallel Multi-Domain Solution Methodology Applied to Nonlinear Thermal Transport Problems in Nuclear Fuel Pins

    SciTech Connect

    Philip, Bobby [ORNL; Berrill, Mark A [ORNL; Allu, Srikanth [ORNL; Hamilton, Steven P [ORNL; Sampath, Rahul S [ORNL; Clarno, Kevin T [ORNL; Dilts, Gary [Los Alamos National Laboratory (LANL)

    2015-01-01

    This paper describes an efficient and nonlinearly consistent parallel solution methodology for solving coupled nonlinear thermal transport problems that occur in nuclear reactor applications over hundreds of individual 3D physical subdomains. Efficiency is obtained by leveraging knowledge of the physical domains, the physics on individual domains, and the couplings between them for preconditioning within a Jacobian Free Newton Krylov method. Details of the computational infrastructure that enabled this work, namely the open source Advanced Multi-Physics (AMP) package developed by the authors are described. Details of verification and validation experiments, and parallel performance analysis in weak and strong scaling studies demonstrating the achieved efficiency of the algorithm are presented. Furthermore, numerical experiments demonstrate that the preconditioner developed is independent of the number of fuel subdomains in a fuel rod, which is particularly important when simulating different types of fuel rods. Finally, we demonstrate the power of the coupling methodology by considering problems with couplings between surface and volume physics and coupling of nonlinear thermal transport in fuel rods to an external radiation transport code.

  3. Automatic rainfall recharge model induction by evolutionary computational intelligence

    NASA Astrophysics Data System (ADS)

    Hong, Yoon-Seok Timothy; White, Paul A.; Scott, David M.

    2005-08-01

    Genetic programming (GP) is used to develop models of rainfall recharge from observations of rainfall recharge and rainfall, calculated potential evapotranspiration (PET) and soil profile available water (PAW) at four sites over a 4 year period in Canterbury, New Zealand. This work demonstrates that the automatic model induction method is a useful development in modeling rainfall recharge. The five best performing models evolved by genetic programming show a highly nonlinear relationship between rainfall recharge and the independent variables. These models are dominated by a positive correlation with rainfall, a negative correlation with the square of PET, and a negative correlation with PAW. The best performing GP models are more reliable than a soil water balance model at predicting rainfall recharge when rainfall recharge is observed in the late spring, summer, and early autumn periods. The "best" GP model provides estimates of cumulative sums of rainfall recharge that are closer than a soil water balance model to observations at all four sites.

  4. Current problems: Plant biomass as raw material for the production of olefins and motor fuels

    SciTech Connect

    Paushkin, Ya.M.; Lapidus, A.L.; Adel`son, S.V.

    1995-01-01

    Apart from petroleum, another reserve of energy that may be tapped is plant biomass - the primary source of life on Earth. Plant biomass is formed every year in the amount of 170-200 billion tonnes (calculated as dry weight), equivalent in energy to 70-80 billion tonnes of crude oil (compare with the world oil production of about 3 billion tonnes). A small percentage of the plant biomass is utilized by the human race (food, construction, fuel, industry) and by the animal world. Most of it vanishes without producing any benefits; it is decomposed and converted to carbon dioxide and water. With modern technology of growing and harvesting biomass, there is no doubt that at least 2.5-5% of the biomass can be utilized; this is equivalent in terms of energy to 2-4 billion tonnes of crude oil or more than 3-6 billion tonnes of coal. In the course of processing plant raw material in the forest industry, agriculture, and other activities, large amounts of organic wastes are formed; these can be utilized directly for energy production - either as solid fuel in the form of fuel briquets, in solid-waste disposal plants for the production of heat in the form of steam, or as a raw material for processing into liquid fuel means of newly developed technology.

  5. Expanded use of fossil fuels by the US and the global carbon dioxide problem

    Microsoft Academic Search

    W. R. Emanuel; J. S. Olson; G. G. Gillough

    1980-01-01

    Projecting present increases in rates of fossil fuel utilization, a doubling of COâ concentration in the atmosphere may be expected within the next 75 years. Based on preliminary calculations, coal utilization by the United States to the year 2020 accounts for between 9 and 15% of the increase in COâ concentration. Carbon dioxide in the atmosphere absorbs infra-red radiation, causing

  6. An Optimal Solution to a General Dynamic Jet Fuel Hedging Problem

    E-print Network

    Powell, Warren B.

    #12;Abstract We propose a dynamic hedging strategy for jet fuel which strikes a balance between over-the-counter (OTC) and exchange-traded derivatives can be used for hedging. Nevertheless, a perfect associated with them. First, they are rather illiquid, making them very expensive. Second, there is counter

  7. Solid polymer electrolytes for rechargeable batteries. Final report

    SciTech Connect

    Narang, S.C.; Ventura, S.C. [SRI International, Menlo Park, CA (United States). Chemistry Lab.

    1992-02-01

    SRI International has synthesized and tested new, dimensionally stable polymer electrolytes for high energy density rechargeable lithium batteries. We have prepared semi-interpenetrating networks of sulfur-substituted polyethyleneoxide with tetmethylorthosilicate (TEOS). The in situ hydrolysis of TEOS produces a mechanically stable three-dimensional network that entangles the polymer electrolytes and makes the film dimensionally flexible and stable. With this approach, the best dimensionally stable polymer electrolyte of this type produced so far, has a room temperature lithium ion conductivity of 7.5 {times} 10{sup {minus}4} S cm{sup {minus}1}. Another type of solid polymer electrolytes, polydiacetylene-based single-ion conductors with high room temperature proton conductivity were also developed. The best conductivity of these polymers is two orders of magnitude higher than that of Nafion under comparable experimental conditions. With further appropriate chemical modification, the new polymers could be used in fuel cells.

  8. Monitoring Cave Recharge in the Edwards Aquifer Recharge Zone for Natural and Simulated Rainfall Events

    NASA Astrophysics Data System (ADS)

    Gregory, L.; Veni, G.; Shade, B.; Wilcox, B. P.; Munster, C. L.; Owens, M. K.

    2005-12-01

    Across semi-arid regions of the world, woody plant encroachment is widespread with potential implications for groundwater recharge and streamflow. In an effort to better understand the interactions between woody plants and recharge, we are monitoring drip rates in shallow caves in the Edwards Aquifer recharge zone of Central Texas. The surface is covered by a dense stand of ashe juniper (Juniperus ashei). In addition to stemflow, throughfall, and surface runoff was monitored for both natural precipitation events as well as simulated rainfall. Interception and throughfall are measured using a grid of rain gauges and throughfall collectors. Surface runoff measurements were quantified with a 15.24 centimeter H- flume instrumented with an ultrasonic water level sensor. Drip collectors constructed inside the cave collect recharge entering the cave from the ceiling. Large scale rainfall simulation equipment onsite allows us to "re-create" these naturally occurring rainfall events and compare the resulting data with that from the original event. Performing these types of tests allows us to learn important information about the cave footprint's ability to transmit recharge waters into the cave. During a simulation, water is applied directly to the cave footprint and not to the entire hillslope as in a natural rain event. We found that recharge for the natural and simulated events were similar. In each case, recharge makes up less than 5% of the water budget, in spite of the fact that there was little, if any, surface runoff. The working hypothesis is that most of the rainfall is routed off the hillslope as lateral subsurface flow.

  9. Results of the international standard problem No. 31 CORA-13 experiment on severe fuel damage

    SciTech Connect

    Firnhaber, M.; Trambauer, K. (Gesellschaft fuer Anlagen- und Reaktorsicherheit, Cologne (Germany)); Hagen, S.; Hofmann, P. (Kernforschungszentrum Karlsruhe (Germany))

    1993-01-01

    The definition of an international standard problem (ISP) exercise is a comparative exercise in which predictions with different computer codes for a given physical problem are compared with each other and a carefully controlled experimental study. The main goal of the ISP is to increase confidence in the validity and accuracy of analytical tools that are used in assessing the safety of nuclear installations. Moreover, it enables the code user to gain experience and to improve competence. The related calculation can be performed with or without previous knowledge of the experimental results; therefore two approaches to performing a standard problem exercise can be defined, [open quotes]open[close quotes] or [open quotes]blind.[close quotes] Following a proposal by the Federal Republic of Germany, principal working group (PWG) No. 2 of the Committee on the Safety of Nuclear Installations offered the CORA-13 experiment as ISP No. 31 to its member countries. The ISP, which was sponsored by the German Minister of Research and Technology, was conducted as a [open quotes]blind[close quotes] standard problem; i.e., only the initial and boundary conditions of the experiment were given to the participants for performing their calculations.

  10. The used nuclear fuel problem - can reprocessing and consolidated storage be complementary?

    SciTech Connect

    Phillips, C.; Thomas, I. [EnergySolutions Federal EPC., 2345 Stevens Drive, Richland, WA 99354 (United States)

    2013-07-01

    This paper describes our CISF (Consolidated Interim Storage Facilities) and Reprocessing Facility concepts and show how they can be combined with a geologic repository to provide a comprehensive system for dealing with spent fuels in the USA. The performance of the CISF was logistically analyzed under six operational scenarios. A 3-stage plan has been developed to establish the CISF. Stage 1: the construction at the CISF site of only a rail receipt interface and storage pad large enough for the number of casks that will be received. The construction of the CISF Canister Handling Facility, the Storage Cask Fabrication Facility, the Cask Maintenance Facility and supporting infrastructure are performed during stage 2. The construction and placement into operation of a water-filled pool repackaging facility is completed for Stage 3. By using this staged approach, the capital cost of the CISF is spread over a number of years. It also allows more time for a final decision on the geologic repository to be made. A recycling facility will be built, this facility will used the NUEX recycling process that is based on the aqueous-based PUREX solvent extraction process, using a solvent of tri-N-butyl phosphate in a kerosene diluent. It is capable of processing spent fuels at a rate of 5 MT per day, at burn-ups up to 50 GWD per ton of spent fuels and a minimum of 5 years out-of-reactor cooling.

  11. Lithium rechargeable cell with a polymer cathode

    NASA Astrophysics Data System (ADS)

    Walker, Charles W., Jr.

    1991-11-01

    Thin films of electropolymerized poly 3-methylthiophene (PMT) were used as a rechargeable cathode in Li(SO2)3AlCl4 electrolyte. Capacity was superior to porous carbon electrodes of like thickness. Pulse power levels of 2 W cm-2 were achieved, and high rate constant current pulses of four-second duration were reproducible over cycles. Cells could be recharged at potentials below 4.0 V, minimizing the formation of chlorine and thereby diminishing the capacity for corrosion. For a primary cell, greater discharge capacity was obtained with thionyl chloride and sulfuryl chloride electrolytes. Since PMT becomes electrically insulating in the reduced state, this could be used as a built-in safety feature to avert the hazards associated with abuse over-discharge.

  12. Reversible (unitised) PEM fuel cell devices

    Microsoft Academic Search

    Trent M. Molter; William F. Smith; Weisberg; Molter

    1999-01-01

    Regenerative fuel cells (RFCs) are enabling for many weight-critical portable applications, since the packaged specific energy (>400 Wh\\/kg) of properly designed lightweight RFC systems is several-fold higher than that of the lightest weight rechargeable batteries. RFC systems can be rapidly refueled (like primary fuel cells), or can be electrically recharged (like secondary batteries) if a refueling infrastructure is not conveniently

  13. Analysis of regenerative fuel cells. Final report

    Microsoft Academic Search

    1982-01-01

    The concept of a rechargeable fuel cell (RFC) system is considered. A newer type of rechargeable battery, the nickel hydrogen (Ni-H2) battery, is also evaluated. A review was made of past studies which showed large variations in weight, cost, and efficiency. Hydrogen-bromine and hydrogen-chlorine regenerable fuel cells were studied, and were found to have a potential for higher energy storage

  14. Ampere-Hour Meter For Rechargeable Battery

    NASA Technical Reports Server (NTRS)

    Tripp, John S.; Schott, Timothy D.; Tcheng, Ping

    1993-01-01

    Low-power analog/digital electronic circuit meters discharge of storage battery in ampere-hours. By metering discharge, one obtains indication of state of charge of battery and avoids unnecessary recharging, maintaining capacity of battery and prolonging life. Because of its small size and low power consumption, useful in such applications as portable video cameras, communication equipment on boats, portable audio equipment, and portable medical equipment.

  15. New mechanically rechargeable zinc-air batteries

    Microsoft Academic Search

    J. Giltner

    1975-01-01

    This report describes the design, development and testing of new mechanically rechargeable zinc-air batteries. Following research and development of a low cost silver-mercury cathode catalyst, prototype battery tests were conducted. Cycle life tests at 3.5 amperes indicated satisfactory performance through at least 26 cycles when this test was terminated for the final hardware build. The cathode bi-cell design utilized the

  16. The rechargeable aluminum-ion battery

    SciTech Connect

    Navaneedhakrishnan, Jayaprakash; Das, Shyamal K; Archer, Lynden A.

    2011-01-01

    We report a novel aluminium-ion rechargeable battery comprised of an electrolyte containing AlCl? in the ionic liquid, 1-ethyl-3-methylimidazolium chloride, and a V?O? nano-wire cathode against an aluminium metal anode. The battery delivered a discharge capacity of 305 mAh g?¹ in the first cycle and 273 mAh g?¹ after 20 cycles, with very stable electrochemical behaviour.

  17. Oil fuel delivery optimization for multi product and multi depot: the case of petrol station replenishment problem (PSRP)

    NASA Astrophysics Data System (ADS)

    Surjandari, Isti; Rachman, Amar; Dianawati, Fauzia; Wibowo, R. Pramono

    2011-10-01

    With the Oil and Gas Law No. 22 of 2001, national and foreign private enterprises can invest in all sectors of Oil and Gas in Indonesia. In anticipation of this free competition, Pertamina, as a state-owned enterprises, which previously had monopolized the oil and gas business activities in Indonesia, should be able to improve services as well as the efficiency in order to compete in the free market, especially in terms of cost efficiency of fuel distribution to gas station (SPBU). To optimize the distribution activity, it is necessary to design a scheduling system and its fuel delivery routes daily to every SPBU. The determination of routes and scheduling delivery of fuel to the SPBU can be modeled as a Petrol Station Replenishment Problem (PSRP) with the multi-depot, multi-product, time windows and split deliveries, which in this study will be completed by the Tabu Search algorithm (TS). This study was conducted in the area of Bandung, the capital of West Java province, which is a big city and the neighboring city of Jakarta, the capital city of Indonesia. By using the fuel delivery data for one day, the results showed a decrease of 16.38% of the distance of the route compared to the current conditions, which impacted on the reduction of distribution costs and decrease the number of total trips by 5.22% and 3.83%.

  18. Nanomaterials for lithium-ion rechargeable batteries.

    PubMed

    Liu, Hua Kun; Wang, Guo Xiu; Guo, Zaiping; Wang, Jiazhao; Konstantinov, Kosta

    2006-01-01

    In lithium-ion batteries, nanocrystalline intermetallic alloys, nanosized composite materials, carbon nanotubes, and nanosized transition-metal oxides are all promising new anode materials, while nanosized LiCoO2, LiFePO4, LiMn2O4, and LiMn2O4 show higher capacity and better cycle life as cathode materials than their usual larger-particle equivalents. The addition of nanosized metal-oxide powders to polymer electrolyte improves the performance of the polymer electrolyte for all solid-state lithium rechargeable batteries. To meet the challenge of global warming, a new generation of lithium rechargeable batteries with excellent safety, reliability, and cycling life is needed, i.e., not only for applications in consumer electronics, but especially for clean energy storage and for use in hybrid electric vehicles and aerospace. Nanomaterials and nanotechnologies can lead to a new generation of lithium secondary batteries. The aim of this paper is to review the recent developments on nanomaterials and nanotechniques used for anode, cathode, and electrolyte materials, the impact of nanomaterials on the performance of lithium batteries, and the modes of action of the nanomaterials in lithium rechargeable batteries. PMID:16573064

  19. The Li-ion rechargeable battery: a perspective.

    PubMed

    Goodenough, John B; Park, Kyu-Sung

    2013-01-30

    Each cell of a battery stores electrical energy as chemical energy in two electrodes, a reductant (anode) and an oxidant (cathode), separated by an electrolyte that transfers the ionic component of the chemical reaction inside the cell and forces the electronic component outside the battery. The output on discharge is an external electronic current I at a voltage V for a time ?t. The chemical reaction of a rechargeable battery must be reversible on the application of a charging I and V. Critical parameters of a rechargeable battery are safety, density of energy that can be stored at a specific power input and retrieved at a specific power output, cycle and shelf life, storage efficiency, and cost of fabrication. Conventional ambient-temperature rechargeable batteries have solid electrodes and a liquid electrolyte. The positive electrode (cathode) consists of a host framework into which the mobile (working) cation is inserted reversibly over a finite solid-solution range. The solid-solution range, which is reduced at higher current by the rate of transfer of the working ion across electrode/electrolyte interfaces and within a host, limits the amount of charge per electrode formula unit that can be transferred over the time ?t = ?t(I). Moreover, the difference between energies of the LUMO and the HOMO of the electrolyte, i.e., electrolyte window, determines the maximum voltage for a long shelf and cycle life. The maximum stable voltage with an aqueous electrolyte is 1.5 V; the Li-ion rechargeable battery uses an organic electrolyte with a larger window, which increase the density of stored energy for a given ?t. Anode or cathode electrochemical potentials outside the electrolyte window can increase V, but they require formation of a passivating surface layer that must be permeable to Li(+) and capable of adapting rapidly to the changing electrode surface area as the electrode changes volume during cycling. A passivating surface layer adds to the impedance of the Li(+) transfer across the electrode/electrolyte interface and lowers the cycle life of a battery cell. Moreover, formation of a passivation layer on the anode robs Li from the cathode irreversibly on an initial charge, further lowering the reversible ?t. These problems plus the cost of quality control of manufacturing plague development of Li-ion rechargeable batteries that can compete with the internal combustion engine for powering electric cars and that can provide the needed low-cost storage of electrical energy generated by renewable wind and/or solar energy. Chemists are contributing to incremental improvements of the conventional strategy by investigating and controlling electrode passivation layers, improving the rate of Li(+) transfer across electrode/electrolyte interfaces, identifying electrolytes with larger windows while retaining a Li(+) conductivity ?(Li) > 10(-3) S cm(-1), synthesizing electrode morphologies that reduce the size of the active particles while pinning them on current collectors of large surface area accessible by the electrolyte, lowering the cost of cell fabrication, designing displacement-reaction anodes of higher capacity that allow a safe, fast charge, and designing alternative cathode hosts. However, new strategies are needed for batteries that go beyond powering hand-held devices, such as using electrode hosts with two-electron redox centers; replacing the cathode hosts by materials that undergo displacement reactions (e.g. sulfur) by liquid cathodes that may contain flow-through redox molecules, or by catalysts for air cathodes; and developing a Li(+) solid electrolyte separator membrane that allows an organic and aqueous liquid electrolyte on the anode and cathode sides, respectively. Opportunities exist for the chemist to bring together oxide and polymer or graphene chemistry in imaginative morphologies. PMID:23294028

  20. High energy density rechargeable magnesium battery using earth-abundant and non-toxic elements

    PubMed Central

    Orikasa, Yuki; Masese, Titus; Koyama, Yukinori; Mori, Takuya; Hattori, Masashi; Yamamoto, Kentaro; Okado, Tetsuya; Huang, Zhen-Dong; Minato, Taketoshi; Tassel, Cédric; Kim, Jungeun; Kobayashi, Yoji; Abe, Takeshi; Kageyama, Hiroshi; Uchimoto, Yoshiharu

    2014-01-01

    Rechargeable magnesium batteries are poised to be viable candidates for large-scale energy storage devices in smart grid communities and electric vehicles. However, the energy density of previously proposed rechargeable magnesium batteries is low, limited mainly by the cathode materials. Here, we present new design approaches for the cathode in order to realize a high-energy-density rechargeable magnesium battery system. Ion-exchanged MgFeSiO4 demonstrates a high reversible capacity exceeding 300?mAh·g?1 at a voltage of approximately 2.4?V vs. Mg. Further, the electronic and crystal structure of ion-exchanged MgFeSiO4 changes during the charging and discharging processes, which demonstrates the (de)insertion of magnesium in the host structure. The combination of ion-exchanged MgFeSiO4 with a magnesium bis(trifluoromethylsulfonyl)imide–triglyme electrolyte system proposed in this work provides a low-cost and practical rechargeable magnesium battery with high energy density, free from corrosion and safety problems. PMID:25011939

  1. High energy density rechargeable magnesium battery using earth-abundant and non-toxic elements

    NASA Astrophysics Data System (ADS)

    Orikasa, Yuki; Masese, Titus; Koyama, Yukinori; Mori, Takuya; Hattori, Masashi; Yamamoto, Kentaro; Okado, Tetsuya; Huang, Zhen-Dong; Minato, Taketoshi; Tassel, Cédric; Kim, Jungeun; Kobayashi, Yoji; Abe, Takeshi; Kageyama, Hiroshi; Uchimoto, Yoshiharu

    2014-07-01

    Rechargeable magnesium batteries are poised to be viable candidates for large-scale energy storage devices in smart grid communities and electric vehicles. However, the energy density of previously proposed rechargeable magnesium batteries is low, limited mainly by the cathode materials. Here, we present new design approaches for the cathode in order to realize a high-energy-density rechargeable magnesium battery system. Ion-exchanged MgFeSiO4 demonstrates a high reversible capacity exceeding 300 mAh.g-1 at a voltage of approximately 2.4 V vs. Mg. Further, the electronic and crystal structure of ion-exchanged MgFeSiO4 changes during the charging and discharging processes, which demonstrates the (de)insertion of magnesium in the host structure. The combination of ion-exchanged MgFeSiO4 with a magnesium bis(trifluoromethylsulfonyl)imide-triglyme electrolyte system proposed in this work provides a low-cost and practical rechargeable magnesium battery with high energy density, free from corrosion and safety problems.

  2. High energy density rechargeable magnesium battery using earth-abundant and non-toxic elements.

    PubMed

    Orikasa, Yuki; Masese, Titus; Koyama, Yukinori; Mori, Takuya; Hattori, Masashi; Yamamoto, Kentaro; Okado, Tetsuya; Huang, Zhen-Dong; Minato, Taketoshi; Tassel, Cédric; Kim, Jungeun; Kobayashi, Yoji; Abe, Takeshi; Kageyama, Hiroshi; Uchimoto, Yoshiharu

    2014-01-01

    Rechargeable magnesium batteries are poised to be viable candidates for large-scale energy storage devices in smart grid communities and electric vehicles. However, the energy density of previously proposed rechargeable magnesium batteries is low, limited mainly by the cathode materials. Here, we present new design approaches for the cathode in order to realize a high-energy-density rechargeable magnesium battery system. Ion-exchanged MgFeSiO4 demonstrates a high reversible capacity exceeding 300 Ah · g(-1) at a voltage of approximately 2.4 V vs. Mg. Further, the electronic and crystal structure of ion-exchanged MgFeSiO4 changes during the charging and discharging processes, which demonstrates the (de)insertion of magnesium in the host structure. The combination of ion-exchanged MgFeSiO4 with a magnesium bis(trifluoromethylsulfonyl)imide-triglyme electrolyte system proposed in this work provides a low-cost and practical rechargeable magnesium battery with high energy density, free from corrosion and safety problems. PMID:25011939

  3. Software problems in the development of the Defense Fuel Automated Management System

    SciTech Connect

    Not Available

    1983-09-06

    A report on a review of the Defense Fuel Automated Management System (DFAMS) is presented. DFAMS is designed as a fully automated integrated system which will handle inventory management, procurement, financial control and accounting for bulk fuel products within the Department of Defense. DFAMS software is being developed with obsolete and vendor-dependent programming techniques. These techniques will cause the delivered system to be unnecessarily costly to maintain and, if incompatible hardware is acquired, lead to high conversion cost. Many commercial software tools are available that run on computers which support ANSI COBOL and can assist in the planning and creation of application systems. It is believed DLA should consider the use of such tools to improve the quality of the DFAMS application software and reduce potential maintenance cost. DFAMS developers do not inspect program code for compliance with DLA, Defense, federal, or ANSI standards. Software tools could greatly reduce the labor of such inspection. The Normalization and ADPER programs appear to be sound ADP management strategies that should achieve DLA's goals of standardizing its software and becoming as machine independent as possible. However, DLA may have difficulty achieving these goals because, at least with DFAMS, it is not enforcing conformance with the Normalization objectives.

  4. Probabilistic analysis of the effects of climate change on groundwater recharge

    Microsoft Academic Search

    Gene-Hua Crystal Ng; Dennis McLaughlin; Dara Entekhabi; Bridget R. Scanlon

    2010-01-01

    Groundwater recharge is likely to be affected by climate change. In semiarid regions where groundwater resources are often critical, annual recharge rates are typically small and most recharge occurs episodically. Such episodic recharge is uncertain and difficult to predict. This paper analyzes the impacts of different climate predictions on diffuse episodic recharge at a low-relief semiarid rain-fed agricultural area. The

  5. A review of groundwater recharge under irrigated agriculture in Australia

    NASA Astrophysics Data System (ADS)

    Riasat, Ali; Mallants, Dirk; Walker, Glen; Silberstein, Richard

    2014-05-01

    Quantification of recharge under irrigated agriculture is one of the most important but difficult tasks. It is the least understood component in groundwater studies because of its large variability in space and time and the difficulty of direct measurement. Better management of groundwater resources is only possible if we can accurately determine all fluxes going into and out of a groundwater system. One of the major challenges facing irrigated agriculture in Australia, and the world, is to reduce uncertainty in estimating or measuring the recharge flux. Reducing uncertainty in groundwater recharge under irrigated agriculture is a pre-requisite for effective, efficient and sustainable groundwater resource management especially in dry areas where groundwater usage is often the key to economic development. An accurate quantification of groundwater recharge under irrigated systems is also crucial because of its potential impacts on soil profile salinity, groundwater levels and groundwater quality. This paper aims to identify the main recharge control parameters thorough a review of past field and modelling recharge studies in Australia. We find that the main recharge control parameters under irrigated agriculture are soil type, irrigation management, watertable depth, land cover or plant water uptake, soil surface conditions, and soil, irrigation water and groundwater chemistry. The most commonly used recharge estimation approaches include chloride mass balance, water budget equation, lysimeters, Darcy's law and numerical models. Main sources and magnitude of uncertainty in recharge estimates associated with these approaches are discussed.

  6. 2/24/2014 Micro-Windmills to Recharge Cell Phones http://www.jadecadelina.com/innovation/micro-windmills-recharge-phones/ 1/2

    E-print Network

    Chiao, Jung-Chih

    2/24/2014 Micro-Windmills to Recharge Cell Phones http://www.jadecadelina.com/innovation/micro-windmills-recharge-phones & Technology Search this site... R ECEN T P OSTS welcome Micro-Windmills to Recharge Cell Phones Super Ty phoon (required) Micro-Windmills to Recharge Cell Phones January 16, 2014 · by mr.jade · in Energy, Innovation

  7. Challenges of Artificial Recharge at the Chain of Lakes

    NASA Astrophysics Data System (ADS)

    Zeng, X.

    2004-12-01

    A series of gravel quarry lakes, A through I (i.e. Chain of Lakes) in Alameda County, California are planned to convert to off-channel spreading lakes for artificial groundwater recharge. An operational plan is needed for the near-term improvements that would allow safe and efficient operations of Lake H and Lake I recently acquired for artificial recharge operations. Water source for the groundwater recharge comes from State Water Project (SWP) water releases at the South Bay Aqueduct turnout. The released water flows approximately nine miles in Arroyo Mocho Creek to the planned diversion facility. The recharge system includes multiple water delivery components and recharge components. Reliability of SWP water delivery is a water supply constraint to the recharge system. Hydraulic capacities of each delivery component and recharge capacities of each recharge component are physical constraints to the development of the operational plan. Policy issues identified in the Mitigated Negative Declaration which contains mitigation measures addressing potential impacts of fisheries and erosion are regulatory constraints to the operational plan development. Our approach that addresses technical challenges and policy issues in the development of the operational plan includes i) determination of lake recharge under observed conditions using water budget method; ii) development and calibration of a ground water flow model using MODFLOW; iii) estimation of lake recharge capacity for a range of lake levels using the calibrated ground water flow model; iv) analysis of clogging layer effects on recharge capacity; and v) development and application of operations models for the stream delivery system and the lake system.

  8. Thin-film rechargeable lithium batteries

    SciTech Connect

    Dudney, N.J.; Bates, J.B.; Lubben, D. [Oak Ridge National Lab., TN (United States). Solid State Div.

    1995-06-01

    Thin-film rechargeable lithium batteries using ceramic electrolyte and cathode materials have been fabricated by physical deposition techniques. The lithium phosphorous oxynitride electrolyte has exceptional electrochemical stability and a good lithium conductivity. The lithium insertion reaction of several different intercalation materials, amorphous V{sub 2}O{sub 5}, amorphous LiMn{sub 2}O{sub 4}, and crystalline LiMn{sub 2}O{sub 4} films, have been investigated using the completed cathode/electrolyte/lithium thin-film battery.

  9. Lithium-intercalation oxides for rechargeable batteries

    NASA Astrophysics Data System (ADS)

    Ceder, Gerbrand; van der Ven, Anton; Aydinol, Mehmet Kadri

    1998-09-01

    Since the introduction of the LixC/LiCoO2 cell, rechargeable lithium batteries have become the technology of choice for applications where volume or weight are a consideration (e.g., laptop computers and cell phones). The focus of current research in cathodeactive materials is on less-expensive or higher-performance materials than LiCoO2. This article illustrates how first-principles calculations can play a critical role in obtaining the understanding needed to design improved cathode oxides.

  10. Evolution of strategies for modern rechargeable batteries.

    PubMed

    Goodenough, John B

    2013-05-21

    This Account provides perspective on the evolution of the rechargeable battery and summarizes innovations in the development of these devices. Initially, I describe the components of a conventional rechargeable battery along with the engineering parameters that define the figures of merit for a single cell. In 1967, researchers discovered fast Na(+) conduction at 300 K in Na ?,?''-alumina. Since then battery technology has evolved from a strongly acidic or alkaline aqueous electrolyte with protons as the working ion to an organic liquid-carbonate electrolyte with Li(+) as the working ion in a Li-ion battery. The invention of the sodium-sulfur and Zebra batteries stimulated consideration of framework structures as crystalline hosts for mobile guest alkali ions, and the jump in oil prices in the early 1970s prompted researchers to consider alternative room-temperature batteries with aprotic liquid electrolytes. With the existence of Li primary cells and ongoing research on the chemistry of reversible Li intercalation into layered chalcogenides, industry invested in the production of a Li/TiS2 rechargeable cell. However, on repeated recharge, dendrites grew across the electrolyte from the anode to the cathode, leading to dangerous short-circuits in the cell in the presence of the flammable organic liquid electrolyte. Because lowering the voltage of the anode would prevent cells with layered-chalcogenide cathodes from competing with cells that had an aqueous electrolyte, researchers quickly abandoned this effort. However, once it was realized that an oxide cathode could offer a larger voltage versus lithium, researchers considered the extraction of Li from the layered LiMO2 oxides with M = Co or Ni. These oxide cathodes were fabricated in a discharged state, and battery manufacturers could not conceive of assembling a cell with a discharged cathode. Meanwhile, exploration of Li intercalation into graphite showed that reversible Li insertion into carbon occurred without dendrite formation. The SONY corporation used the LiCoO2/carbon battery to power their initial cellular telephone and launched the wireless revolution. As researchers developed 3D transition-metal hosts, manufacturers introduced spinel and olivine hosts in the Lix[Mn2]O4 and LiFe(PO4) cathodes. However, current Li-ion batteries fall short of the desired specifications for electric-powered automobiles and the storage of electrical energy generated by wind and solar power. These demands are stimulating new strategies for electrochemical cells that can safely and affordably meet those challenges. PMID:22746097

  11. Polyphase alloys as rechargeable electrodes in advanced battery systems

    NASA Technical Reports Server (NTRS)

    Huggins, Robert A.

    1987-01-01

    The rechargeability of electrochemical cells is often limited by negative electrode problems. These may include loss of capacity, increased impedance, macroscopic shape change, dendrite growth, or a tendency for filamentary or whisker growth. In principle, these problems can be reduced or eliminated by the use of alloys that undergo either displacement or insertion reactions at reactant species activities less than unity, rather than pure elements. The fundamental reasons for some of these problems with elemental electrodes, as well as the basic principles involved in the different behavior of alloys, are briefly discussed. More information is now available concerning the thermodynamic and kinetic properties of a number of alloys of potential interest for use as electrodes in elevated temperature lithium battery systems. Recent results have extended these results down to ambient temperatures, indicating that some such materials may be of interest for use with new low temperature molten salt electrolytes, or with organic solvent electrolytes. The all solid mixed conductor matrix concept is also reviewed.

  12. Availability of streamflow for recharge of the basal aquifer in the Pearl Harbor area, Hawaii

    USGS Publications Warehouse

    Hirashima, George Tokusuke

    1971-01-01

    The Pearl Harbor area is underlain by an extensive basal aquifer that contains large supplies of fresh water. Because of the presence of a cap rock composed of sedimentary material that is less permeable than the basaltic lava of the basal aquifer, seaward movement of ground water is retarded. The cap rock causes the basal water to stand at a high level; thus, the lens of fresh water that floats on sea water is thick. Discharge from the basal ground-water body, which includes pumpage from wells and shafts, averaged 250 million gallons per day during 1931-65. Because the water level in the basal aquifer did not decline progressively, recharge to the ground-water body must have been approximately equal to discharge. Although pumping for agricultural use has decreased since 1931, net ground-water discharge has increased because of a large increase in pumping for urban use. Substitution of ground water for surface water in the irrigation of sugarcane has also contributed to a net increase in ground-water discharge. The development of Mililani Town will further increase discharge. The increase in ground-water discharge may cause an increase in chloride content of the water pumped from wells near the shore of Pearl Harbor unless the increased discharge is balanced by increased recharge to the local aquifer. The aquifer is recharged by direct infiltration and deep percolation of rain, principally in the high forested area, by infiltration and percolation of irrigation water applied in excess of plant requirements, by seepage of water through streambeds, and possibly by ground-water inflow from outside the area. Recharge is greatest in the uplands, where rainfall is heavy and where much infiltration takes place before rainwater collects in the middle and lower reaches of stream channels. Once water collects in and saturates the alluvium of stream channels, additional inflow to the streams will flow out to sea, only slightly decreased by seepage. Average annual direct runoff from the 90-square-mile Pearl Harbor area is 47.27 million gallons per day, or 11.1 inches; this is 13.3 percent of the average annual rainfall (83.3 in.) over the area. Average annual direct runoff in streams at the 800- and 400-foot altitudes is 29 and 38 million gallons per day, respectively. Kipapa Stream has the largest average annual direct runoff at those altitudes--6 and 9 million gallons per day, respectively. Because streams are flashy and have a wide range in discharge, only 60 percent of the average annual runoff can be economically diverted through ditches to recharge areas. The diversion may be increased slightly if reservoirs are used in conjunction with ditches to temporarily detain flows in excess of ditch capacity. The planned irrigation use of some of the perennial flow available in Waikele Stream near sea level will decrease pumping from and increase recharge to the basal aquifer. Suspended-sediment load is mainly silt and clay, and it increases rapidly with increased discharge. Thus, the use of streamflow for artificial recharge poses problems. High flows must be used if recharge is to be effective, but flows must not be so high as to cause clogging of recharge facilities with sediment or woodland debris. Practical tests are needed to determine the advantages and disadvantages of different types of recharge structures, such as a reservoir or basin, large-diameter deep shafts, deep wells, or combinations of all these structures.

  13. Impacts on groundwater recharge areas of megacity pumping: analysis of potential contamination of Kolkata, India, water supply

    USGS Publications Warehouse

    Sahu, Paulami; Michael, Holly A.; Voss, Clifford I.; Sikdar, Pradip K.

    2013-01-01

    Water supply to the world's megacities is a problem of quantity and quality that will be a priority in the coming decades. Heavy pumping of groundwater beneath these urban centres, particularly in regions with low natural topographic gradients, such as deltas and floodplains, can fundamentally alter the hydrological system. These changes affect recharge area locations, which may shift closer to the city centre than before development, thereby increasing the potential for contamination. Hydrogeological simulation analysis allows evaluation of the impact on past, present and future pumping for the region of Kolkata, India, on recharge area locations in an aquifer that supplies water to over 13 million people. Relocated recharge areas are compared with known surface contamination sources, with a focus on sustainable management of this urban groundwater resource. The study highlights the impacts of pumping on water sources for long-term development of stressed city aquifers and for future water supply in deltaic and floodplain regions of the world.

  14. Analysis of regenerative fuel cells

    NASA Astrophysics Data System (ADS)

    Gross, S.

    1982-11-01

    The concept of a rechargeable fuel cell (RFC) system is considered. A newer type of rechargeable battery, the nickel hydrogen (Ni-H2) battery, is also evaluated. A review was made of past studies which showed large variations in weight, cost, and efficiency. Hydrogen-bromine and hydrogen-chlorine regenerable fuel cells were studied, and were found to have a potential for higher energy storage efficiency then the hydrogen-oxygen system. A reduction of up to 15 percent in solar array size may be possible as a result. These systems are not yet developed, but further study of them is recommended.

  15. Compliance problems of small utility systems with the Powerplant and Industrial Fuel Use Act of 1978: volume II - appendices

    SciTech Connect

    None

    1981-01-01

    A study of the problems of compliance with the Powerplant and Industrial Fuel Use Act of 1978 experienced by electric utility systems which have a total generating capacity of less than 2000 MW is presented. This volume presents the following appendices: (A) case studies (Farmington, New Mexico; Lamar, Colorado; Dover, Delaware; Wolverine Electric Cooperative, Michigan; Central Telephone and Utilities, Kansas; Sierra Pacific Power Company, Nevada; Vero Beach, Florida; Lubbock, Texas; Western Farmers Cooperative, Oklahoma; and West Texas Utilities Company, Texas); (B) contacts and responses to study; (C) joint action legislation chart; (D) Texas Municipal Power Agency case study; (E) existing generating units jointly owned with small utilities; (F) future generating units jointly owned with small utilities; (G) Federal Register Notice of April 17, 1980, and letter of inquiry to utilities; (H) small utility responses; and (I) Section 744, PIFUA. (WHK)

  16. Modelling of groundwater mound formation resulting from transient recharge

    Microsoft Academic Search

    S. N. Rai; D. V. Ramana; S. Thiagarajan; A. Manglik

    2001-01-01

    An analytical solution of a linearized Boussinesq equation is obtained to predict water table fluctuations as a result of time varying recharge from a strip basin for any number of recharge cycles. The analytical solution is obtained by using finite Fourier sine transform. Applications of the solution for the prediction of water table fluctuations and sensitivity analysis are demonstrated with

  17. Autonomous Battery Recharging for Indoor Mobile Robots Seungjun Oh

    E-print Network

    1 Autonomous Battery Recharging for Indoor Mobile Robots Seungjun Oh Australian National University the batteries on a mobile robot. The robot used in this project is the Nomadic Technologies? Nomad XR4000 mobile robot. The battery recharging system was implemented using the robot's built-in sensors to control

  18. Intrinsically safe 5-V, 4-A rechargeable power supply

    Microsoft Academic Search

    John J. Sammarco

    1989-01-01

    The U.S. Bureau of Mines has developed a regulated, intrinsically safe, rechargeable power supply for portable electronic equipment for underground use. The regulated output is ideal for microprocessor power requirements and is suited for operation in hazardous environments. Two rechargeable, sealed batteries are contained within the power supply. Provisions are made to use an external source of power if these

  19. Comparative analysis of piezoelectric power harvesting circuits for rechargeable batteries

    Microsoft Academic Search

    Mingjie Guan; Wei-Hsin Liao

    2005-01-01

    Using piezoelectric materials to harvest energy from ambient vibrations to power wireless sensors has been of great interest over the past few years. Due to the power output of the piezoelectric materials is relatively low, rechargeable battery is considered as one kind of energy storage to accumulate the harvested energy for intermittent use. Piezoelectric harvesting circuits for rechargeable batteries have

  20. ESTIMATION OF GROUND WATER RECHARGE USING SOIL MOISTURE BALANCE APPROACH

    E-print Network

    Kumar, C.P.

    ESTIMATION OF GROUND WATER RECHARGE USING SOIL MOISTURE BALANCE APPROACH C. P. Kumar* ABSTRACT The amount of water that may be extracted from an aquifer without causing depletion is primarily dependent upon the ground water recharge. Thus, a quantitative evaluation of spatial and temporal distribution

  1. Block Copolymer-Templated Nanocomposite Electrodes for Rechargeable Lithium Batteries

    E-print Network

    Sadoway, Donald Robert

    of rechargeable lithium batteries, the search for high capacity anodes that avoid the safety concerns associatedBlock Copolymer-Templated Nanocomposite Electrodes for Rechargeable Lithium Batteries S. C. Mui in lithium-alloying metals.1-4 While some lithium alloys such as Li-Sn have high theoretical capacities 990 m

  2. Infiltration-recharge through wadi beds in arid regions

    Microsoft Academic Search

    ALI U. SORMAN; J. ABDULRAZZAK

    1993-01-01

    Groundwater recharge in arid regions is intermittent and usually occurs as a result of flood flow transmission losses in dry wadi channels. Hydrograph characteristics play a dominant role in determining the amount of channel abstraction in relation to the width of the wetted perimeter and the time of inundation, and the subsequent groundwater recharge. Large variations in the magnitude of

  3. Computational Aspect of Artificial Ground Water Recharging into Unconfined Aquifer

    Microsoft Academic Search

    Pratima Patel; M. D. Desai

    CARE FOR GROUND WATER BEFORE IT BECOMES RARE therefore CATCHES WATER IN EVERY POSSIBLE WAY AND EVERY POSSIBLE PLACE IT FALLS. Mathematical aspect of ground water flow related to unconfined aquifer and a change in saturated thickness with variation in piezometric level so, permeability k, radius of influences L, distance between two recharge wells and presence of recharge by rainfall

  4. Advances of aqueous rechargeable lithium-ion battery: A review

    NASA Astrophysics Data System (ADS)

    Alias, Nurhaswani; Mohamad, Ahmad Azmin

    2015-01-01

    The electrochemical characteristic of the aqueous rechargeable lithium-ion battery has been widely investigated in efforts to design a green and safe technology that can provide a highly specific capacity, high efficiency and long life for high power applications such as the smart grid and electric vehicle. It is believed that the advantages of this battery will overcome the limitations of the rechargeable lithium-ion battery with organic electrolytes that comprise safety and create high fabrication cost issues. This review focuses on the opportunities of the aqueous rechargeable lithium-ion battery compared to the conventional rechargeable lithium-ion battery with organic-based electrolytes. Previously reported studies are briefly summarised, together with the presentation of new findings based on the conductivity, morphology, electrochemical performance and cycling stability results. The factors that influence the electrochemical performance, the challenges and potential of the aqueous rechargeable lithium-ion battery are highlighted in order to understand and maintained the excellent battery performance.

  5. PROBLEMS

    Microsoft Academic Search

    Philippe Geuzaine; Kristoer van der Zee; Charbel Farhat

    A methodology for designing formally second-order time-accurate and yet loosely coupled partitioned procedures for the solution of nonlinear fluid-structure interac- tion (FSI) problems is presented. Its key components are a fluid time-integrator that is provably second-order time-accurate on moving grids, the midpoint rule for advancing in time the solution of the structural dynamics equations of motion, a second-order structure predictor

  6. Determining the recharge mode of Sahelian aquifers using water isotopes

    NASA Astrophysics Data System (ADS)

    Girard, Pierre; Hillaire-Marcel, Claude; Oga, Marie Solange

    1997-10-01

    It is proposed that the drainage network plays an important role in the recharge process of the fractured aquifers in the African Precambrian shield and that the fractured aquifer system is likely to be hydraulically continuous; this contrasts with most previous studies, which suggested direct recharge by rainwater percolation. Two areas were selected in Niger for the study of the aquifer recharge process using isotopic analyses of water ( 2H, 18O, 3H). The first area, centred on the village of Kobio, is the 21-km 2 drainage basin of the Lomona intermittent stream, some 60 km southwest of Niamey (the capital city of Niger). The second area, in the vicinity of Niamey, represents a portion of the Niger basin, draining a surface area many orders of magnitude larger than the Lomona basin. The mean 18O composition of water from all wells in the Kobio aquifer provides evidence for recharge by evaporated water. This is confirmed by the concomitant increase of 18O content with rising static water levels as recharge proceeded. Tritium data suggest progressive aging of the Kobio aquifer water in the flow direction inferred from static water levels, with a down-gradient depletion of 18O composition, suggesting that `enriched' recharge water is progressively mixed with `depleted' aquifer water. Recharge by a reach of the Lomona is proposed to explain these results. In the Niamey area wells, the 18O time series clearly define an injection of evaporated water from the surface into the fractured aquifer. This recharging plume of evaporated water most likely originates from the Niger River. Thus, isotope data for two drainage basins of very different sizes indicate that aquifers are recharged by water from the rivers and that the flow regime of surface waters controls the recharge process.

  7. Climate variability effects on urban recharge beneath low impact development

    NASA Astrophysics Data System (ADS)

    Newcomer, M. E.; Gurdak, J. J.

    2012-12-01

    Groundwater resources in urban and coastal environments are highly vulnerable to human pressures and climate variability and change, and many communities face water shortages and need to find alternative water supplies. Therefore, understanding how low impact development (LID) site planning and integrated/best management practices (BMPs) affect recharge rates and volumes is important because of the increasing use of LID and BMP to reduce stormwater runoff and improve surface-water quality. Often considered a secondary management benefit, many BMPs may also enhance recharge to local aquifers; however these hypothesized benefits have not been thoroughly tested or quantified. In this study, we quantify stormwater capture and recharge enhancement beneath a BMP infiltration trench of the LID research network at San Francisco State University, San Francisco, California. Stormwater capture and retention was analyzed using the SCS TR-55 curve number method and in-situ infiltration rates to assess LID storage. Recharge was quantified using vadose zone monitoring equipment, a detailed water budget analysis, and a Hydrus-2D model. Additionally, the effects of historical and predicted future precipitation on recharge rates were examined using precipitation from the Geophysical Fluid Dynamic Laboratory (GFDL) A1F1 climate scenario. Observed recharge rates beneath the infiltration trench range from 1,600 to 3,700 mm/year and are an order of magnitude greater than recharge beneath an irrigated grass lawn and a natural setting. The Hydrus-2D model results indicate increased recharge under the GFDL A1F1 scenario compared with historical and GFDL modeled 20th century rates because of the higher frequency of large precipitation events that induce runoff into the infiltration trench. However, under a simulated A1F1 El Niño year, recharge calculated by a water budget does not increase compared with current El Niño recharge rates. In comparison, simulated recharge rates were considerably lower beneath the grass lawn for historical and future precipitation years. This work highlights the potential management strategy of using LID to capture excess runoff during El Niño years that can be recharged and stored as groundwater. An additional benefit of LID in coastal aquifer systems is the ability to capture and redirect precipitation from runoff to recharge that may help mitigate the negative effects from groundwater pumping and sea-water intrusion.

  8. Polymer Energy Rechargeable System Battery Being Developed

    NASA Technical Reports Server (NTRS)

    Manzo, Michelle A.

    2003-01-01

    Long description. Illustrations of discotic liquid crystals, rod-coil polymers, lithium-ion conducting channel dilithium phthalocyanine (Li2Pc) from top and side, novel star polyethylene oxide structures, composite polyethylene oxide materials (showing polyethylene oxide + lithium salt, carbon atoms and oxygen atoms), homopolyrotaxanes, and diblock copolymers In fiscal year 2000, NASA established a program to develop the next generation, lithium-based, polymer electrolyte batteries for aerospace applications. The goal of this program, known as Polymer Energy Rechargeable Systems (PERS), is to develop a space-qualified, advanced battery system embodying polymer electrolyte and lithium-based electrode technologies and to establish world-class domestic manufacturing capabilities for advanced batteries with improved performance characteristics that address NASA s future aerospace battery requirements.

  9. Advanced rechargeable sodium batteries with novel cathodes

    NASA Technical Reports Server (NTRS)

    Di Stefano, S.; Ratnakumar, B. V.; Bankston, C. P.

    1990-01-01

    Various high energy density rechargeable batteries are being considered for future space applications. Of these, the sodium-sulfur battery is one of the leading candidates. The primary advantage is the high energy density (760 W h/kg theoretical). Energy densities in excess of 180 W h/kg have been realized in practical batteries. More recently, cathodes other than sulfur are being evaluated. Various new cathode materials are presently being evaluated for use in high energy density sodium batteries for advanced space applications. The approach is to carry out basic electrochemical studies of these materials in a sodium cell configuration in order to understand their fundamental behaviors. Thus far, the studies have focussed on alternative metal chlorides such as CuCl2 and organic cathode materials such as TCNE.

  10. Advanced rechargeable sodium batteries with novel cathodes

    NASA Technical Reports Server (NTRS)

    Distefano, S.; Ratnakumar, B. V.; Bankston, C. P.

    1989-01-01

    Various high energy density rechargeable batteries are being considered for future space applications. Of these, the sodium sulfur battery is one of the leading candidates. The primary advantage is the high energy density (760 Wh/kg theoretical). Energy densities in excess of 180 Wh/kg have been realized in practical batteries. More recently, cathodes other than sulfur are being evaluated. Researchers at JPL are evaluating various new cathode materials for use in high energy density sodium batteries for advanced space applications. The approach is to carry out basic electrochemical studies of these materials in a sodium cell configuration in order to understand their fundamental behaviors. Thus far studies have focused on alternate metal chlorides such as CuCl2 and organic cathode materials such as tetracyanoethylene (TCNE).

  11. Thin-film rechargeable lithium batteries

    SciTech Connect

    Dudney, N.J.; Bates, J.B.; Lubben, D.

    1994-11-01

    Small thin-film rechargeable cells have been fabricated with a lithium phosphorus oxyniuide electrolyte, Li metal anode, and Li{sub 1-x}Mn{sub 2}O{sub 4} as the cathode film. The cathode films were fabricated by several different techniques resulting in both crystalline and amorphous films. These were compared by observing the cell discharge behavior. Estimates have been made for the scale-up of such a thin-film battery to meet the specifications for the electric vehicle application. The specific energy, energy density, and cycle life are expected to meet the USABC mid-term criteria. However, the areas of the thin-films needed to fabricate such a cell are very large. The required areas could be greatly reduced by operating the battery at temperatures near 100{degrees}C or by enhancing the lithium ion transport rate in the cathode material.

  12. Polymer Energy Rechargeable System (PERS) Development Program

    NASA Technical Reports Server (NTRS)

    Baldwin, Richard S.; Manzo, Michelle A.; Dalton, Penni J.; Marsh, Richard A.; Surampudi, Rao

    2001-01-01

    The National Aeronautics and Space Administration (NASA) and the Air Force Research Laboratory (AFRL) have recently established a collaborative effort to support the development of polymer-based, lithium-based cell chemistries and battery technologies to address the next generation of aerospace applications and mission needs. The overall objective of this development program, which is referred to as PERS, Polymer Energy Rechargeable System, is to establish a world-class technology capability and U.S. leadership in polymer-based battery technology for aerospace applications. Programmatically, the PERS initiative will exploit both interagency collaborations to address common technology and engineering issues and the active participation of academia and private industry. The initial program phases will focus on R&D activities to address the critical technical issues and challenges at the cell level.

  13. Unlinkable Priced Oblivious Transfer with Rechargeable Wallets

    NASA Astrophysics Data System (ADS)

    Camenisch, Jan; Dubovitskaya, Maria; Neven, Gregory

    We present the first truly unlinkable priced oblivious transfer protocol. Our protocol allows customers to buy database records while remaining fully anonymous, i.e., (1) the database does not learn who purchases a record, and cannot link purchases by the same customer; (2) the database does not learn which record is being purchased, nor the price of the record that is being purchased; (3) the customer can only obtain a single record per purchase, and cannot spend more than his account balance; (4) the database does not learn the customer's remaining balance. In our protocol customers keep track of their own balances, rather than leaving this to the database as done in previous protocols. Our priced oblivious transfer protocol is also the first to allow customers to (anonymously) recharge their balances. Finally, we prove our protocol secure in the standard model (i.e., without random oracles).

  14. Geostatistical estimates of future recharge for the Death Valley region

    SciTech Connect

    Hevesi, J.A. [Geological Survey, Las Vegas, NV (United States); Flint, A.L. [Geological Survey, Sacramento, CA (United States)

    1998-12-01

    Spatially distributed estimates of regional ground water recharge rates under both current and potential future climates are needed to evaluate a potential geologic repository for high-level nuclear waste at Yucca Mountain, Nevada, which is located within the Death Valley ground-water region (DVGWR). Determining the spatial distribution of recharge is important for regional saturated-zone ground-water flow models. In the southern Nevada region, the Maxey-Eakin method has been used for estimating recharge based on average annual precipitation. Although this method does not directly account for a variety of location-specific factors which control recharge (such as bedrock permeability, soil cover, and net radiation), precipitation is the primary factor that controls in the region. Estimates of recharge obtained by using the Maxey-Eakin method are comparable to estimates of recharge obtained by using chloride balance studies. The authors consider the Maxey-Eakin approach as a relatively simple method of obtaining preliminary estimates of recharge on a regional scale.

  15. Echo Meadows Project Winter Artificial Recharge.

    SciTech Connect

    Ziari, Fred

    2002-12-19

    This report discusses the findings of the Echo Meadows Project (BPA Project 2001-015-00). The main purpose of this project is to artificially recharge an alluvial aquifer, WITH water from Umatilla River during the winter high flow period. In turn, this recharged aquifer will discharge an increased flow of cool groundwater back to the river, thereby improving Umatilla River water quality and temperature. A considerable side benefit is that the Umatilla River should improve as a habitat for migration, spanning, and rearing of anadromous and resident fish. The scope of this project is to provide critical baseline information about the Echo Meadows and the associated reach of the Umatilla River. Key elements of information that has been gathered include: (1) Annual and seasonal groundwater levels in the aquifer with an emphasis on the irrigation season, (2) Groundwater hydraulic properties, particularly hydraulic conductivity and specific yield, and (3) Groundwater and Umatilla River water quality including temperature, nutrients and other indicator parameters. One of the major purposes of this data gathering was to develop input to a groundwater model of the area. The purpose of the model is to estimate our ability to recharge this aquifer using water that is only available outside of the irrigation season (December through the end of February) and to estimate the timing of groundwater return flow back to the river. We have found through the data collection and modeling efforts that this reach of the river had historically returned as much as 45 cubic feet per second (cfs) of water to the Umatilla River during the summer and early fall. However, this return flow was reduced to as low as 10 cfs primarily due to reduced quantities of irrigation application, gain in irrigation efficiencies and increased groundwater pumping. Our modeling indicated that it is possible to restore these critical return flows using applied water outside of the irrigation season. We further found that this water can be timed to return to the river during the desired time of the year (summer to early fall). This is because the river stage, which remains relatively high until this time, drops during the irrigation season-thereby releasing the stored groundwater and increasing river flows. A significant side benefit is that these enhanced groundwater return flows will be clean and cold, particularly as compared to the Umatilla River. We also believe that this same type of application of water could be done and the resulting stream flows could be realized in other watersheds throughout the Pacific Northwest. This means that it is critical to compare the results from this baseline report to the full implementation of the project in the next phase. As previously stated, this report only discusses the results of data gathered during the baseline phase of this project. We have attempted to make the data that has been gathered accessible with the enclosed databases and spreadsheets. We provide computer links in this report to the databases so that interested parties can fully evaluate the data that has been gathered. However, we cannot emphasize too strongly that the real value of this project is to implement the phases to come, compare the results of these future phases to this baseline and develop the science and strategies to successfully implement this concept to other rivers in the Pacific Northwest. The results from our verified and calibrated groundwater model matches the observed groundwater data and trends collected during the baseline phase. The modeling results indicate that the return flows may increase to their historic values with the addition of 1 acre-ft/acre of recharge water to the groundwater system (about 9,600 acre-feet total). What this means is that through continued recharge project, you can double to quadruple the annual baseflow of the Umatilla River during the low summer and fall flow periods as compared to the present base-flow. The cool and high quality recharge water is a significant beneficial impact to the river system.

  16. Extracellular enzyme activities during slow sand filtration in a water recharge plant.

    PubMed

    Hendel, B; Marxsen, J; Fiebig, D; Preuss, G

    2001-07-01

    Activities of the extracellular enzymes beta-glucosidase and phosphatase and bacterial densities were investigated during the filtration process at several sites in a groundwater recharge plant at the Ruhr river (Hengsen recharge plant in Schwerte. Germany). Low numbers of microorganisms and low levels of activity in this type of habitat, compared to most surface waters, caused methodological problems when determining microbial activity. In this study, fluorigenic model substrates, which enable hydrolytic rates as low as 1 nmol (L x h)(-1) to be measured, were used to determine extracellular enzyme activities. Highest activities were determined in surface water (107 nmol (L x h)(-1) for beta-glucosidase and 252 nmol (L x h)(-1) for phosphatase). which decreased during the filtration process in the gravel prefilter and the main sand filter until the end of subsurface flow (1.6 nmol (L x h)(-1) and 6.8 nmol (L x h)(-1), respectively). Similarly, bacterial numbers decreased from 3.4 x 10(6) to 0.29 x 10(6) cells mL(-1). These data showed that microbial activity within the prefilter and the shallow layers of the sand filter had the greatest impact on water quality. In addition to its involvement in the continuous purification of surface water, the microbial community in the sand filter probably acts as a biological buffer against ephemeral increases in the loads of organic matter and nutrients in the recharge plant. PMID:11394783

  17. Delineating spring recharge areas in a fractured sandstone aquifer (Luxembourg) based on pesticide mass balance

    NASA Astrophysics Data System (ADS)

    Farlin, J.; Drouet, L.; Gallé, T.; Pittois, D.; Bayerle, M.; Braun, C.; Maloszewski, P.; Vanderborght, J.; Elsner, M.; Kies, A.

    2013-06-01

    A simple method to delineate the recharge areas of a series of springs draining a fractured aquifer is presented. Instead of solving the flow and transport equations, the delineation is reformulated as a mass balance problem assigning arable land in proportion to the pesticide mass discharged annually in a spring at minimum total transport cost. The approach was applied to the Luxembourg Sandstone, a fractured-rock aquifer supplying half of the drinking water for Luxembourg, using the herbicide atrazine. Predictions of the recharge areas were most robust in situations of strong competition by neighbouring springs while the catchment boundaries for isolated springs were extremely sensitive to the parameter controlling flow direction. Validation using a different pesticide showed the best agreement with the simplest model used, whereas using historical crop-rotation data and spatially distributed soil-leaching data did not improve predictions. The whole approach presents the advantage of integrating objectively information on land use and pesticide concentration in spring water into the delineation of groundwater recharge zones in a fractured-rock aquifer.

  18. Recharge estimation in a large semi-arid basin using storage - discharge relationships

    NASA Astrophysics Data System (ADS)

    Bulovic, Nena; Larsen, Joshua; Reading, Lucy; McIntyre, Neil; Jarihani, Abdollah; Sabburg, Letitia; Undershultz, Jim

    2015-04-01

    The characteristics of flow recession in the absence of precipitation have long been used to infer upstream catchment storage properties. An intriguing aspect of this storage - discharge relationship occurs when changes in flow recession occur following a rainfall event due to increased storage. The main assumption in this case is that additional groundwater recharge has increased the storage within flow systems connected to the stream, which is then reflected in the increased recessional flow. Using flow records from 4 catchments (~100 km2) across the headwaters of the semi-arid Condamine Basin (and the unconfined section of the Surat artesian groundwater basin) within central eastern Australia, we evaluate and compare storage -discharge relationships and the change in storage for large individual events. Converting this to recharge resulted in low values compared to a number of independent recharge estimation techniques (chloride mass balance, water balance, groundwater hydrograph analysis). This discrepancy may arise because of some inherent differences between the techniques, however some important assumptions in the storage - discharge analysis are worth exploring. These include: the impact of evapotranspiration (ET) on the flow recession, which is largely unaccounted for, and is likely to be significant in semi-arid environments, and the bias towards larger events within the analysis, which is related to the difficulty associated with incorporating the large number of small events within automated time series analysis. We propose accounting for these limitations through the inclusion of remote sensing based ET estimates, and the use of multiple automated hydrograph separation techniques in extracting flow recession periods for analysis, and preferably those with lower user subjectivity. Overcoming these limitations is essential if catchment storage - discharge analysis techniques are to be more broadly applied to groundwater recharge estimation problems, especially in data poor semi-arid areas where the need for a better understanding of available water resources is only increasing.

  19. Evaluation of groundwater recharge in Choushui River alluvial fan and Mingchu Basin for specific rainfall events

    NASA Astrophysics Data System (ADS)

    Lin, Zong Sheng; Chen, Jui-Sheng; Jang, Cheng-Shin

    2014-05-01

    Sound groundwater resources planning and management are lack in the Choushui River alluvial fan, resulting in the occurrence of serious land subsidence and seawater intrusion. Even the disasters induced by overpumping of groundwater pose a potential threat on the Taiwan High Speed Rail. In addition to improving the water resources management in the alluvial fan, the development of groundwater resources in the neighboring hills. Mingchu Basin, which is located on the midstream segment of the Choushui River and comprised of the gravel formation of Pleistocene, is an effective solution to resolve the problem in limited water resources. Moreover, the Dongpurui River and Qingshui River both converge into Choushui River in this basin. Because of wide drainage areas and good hydrogeological conditions, the Mingchu Basin is considered a high potential recharging region of groundwater. This work is to evaluate the groundwater recharge in the Choushui River alluvial fan and Mingchu Basin, using the WASH123D model equipped with the Groundwater Modeling System (GMS) to simulate the interaction of surface water and groundwater for specific five rainfall events. This study particularly focuses on the simulation of the groundwater flow, and evaluates the effect of different rainfall events on the groundwater recharge. First, to meet in-situ hydrogeological structure and hydraulic parameters, the GMS is used to construct hydrogeological database, mesh, hydrogeological parameters, initial condition and boundary conditions. Then, simulated parameters, such as hydraulic conductivity and pumping rates, need to be calibrated and verified in the model. After the calibration and verification, the simulated groundwater flow can reflect actual groundwater situation. Finally, when specific five rainfall events impose on the ground, groundwater recharge can be determined using the groundwater model.

  20. Soil Water Balance and Recharge Monitoring at the Hanford Site – FY 2010 Status Report

    SciTech Connect

    Fayer, Michael J.; Saunders, Danielle L.; Herrington, Ricky S.; Felmy, Diana

    2010-10-27

    This report summarizes the recharge data collected in FY 2010 at five locations on the Hanford Site in southeastern Washington State. Average monthly precipitation and temperature conditions in FY 2010 were near normal and did not present an opportunity for increased recharge. The recharge monitoring data confirmed those conditions, showing normal behavior in water content, matric head, and recharge rates. Also provided in this report is a strategy for recharge estimation for the next 5 years.

  1. GROUNDWATER RECHARGE/DISCHARGE, NEUSE RIVER WATERSHED, NC

    EPA Science Inventory

    The North Carolina Department of Environment and Natural Resources, Division of Water Quality and Groundwater Section, in cooperation with the NC Center for Geographic Information and Analysis, developed the Groundwater Recharge/Discharge digital data to enhance planning, siting ...

  2. Transportation Center Seminar "Electric Vehicle Recharging: Decision Support

    E-print Network

    Bustamante, Fabián E.

    Transportation Center Seminar "Electric Vehicle Recharging: Decision Support Tools for Drivers Conference Center Refreshments available at 3:30 pm Abstract: Plug-in electric vehicles (PEVs) have become electric vehicles. #12;

  3. Improved zinc electrode and rechargeable zinc-air battery

    DOEpatents

    Ross, P.N. Jr.

    1988-06-21

    The invention comprises an improved rechargeable zinc-air cell/battery having recirculating alkaline electrolyte and a zinc electrode comprising a porous foam support material which carries the active zinc electrode material. 5 figs.

  4. Rapid recharge capability of valve-regulated lead-acid batteries for electric vehicle and hybrid electric vehicle applications

    NASA Astrophysics Data System (ADS)

    Fleming, F. A.; Shumard, P.; Dickinson, B.

    Range limitation is a significant drawback to the successful commercialization of electric vehicles (EVs). An apt description of an EV is `a high performance vehicle with a one-gallon fuel tank'. In the absence of a `super battery', there are at least two approaches to resolving this drawback. The first approach is rapid recharge, i.e., recharging the battery as close as possible to the same time period as it takes to fill the petrol tank of an internal-combustion-engined (ICE) vehicle. Whilst not extending the vehicle range as such, this approach does enable high usage of the vehicle without experiencing unduly long recharge times. The ability of the battery to accept rapid recharge is paramount for this approach. The second approach is the development of a hybrid electric vehicle (HEV). In this case, the demand on the battery is the ability to provide, and also absorb from regenerative braking, high specific peak-power levels over a wide range of battery state-of-charge. This paper describes the ability, and indeed limitations, of the valve-regulated Genesis® lead-acid battery in meeting such requirements.

  5. Modern recharge to fossil aquifers: Geochemical, geophysical, and modeling constraints

    NASA Astrophysics Data System (ADS)

    Sultan, M.; Metwally, S.; Milewski, A.; Becker, D.; Ahmed, M.; Sauck, W.; Soliman, F.; Sturchio, N.; Yan, E.; Rashed, M.; Wagdy, A.; Becker, R.; Welton, B.

    2011-06-01

    The Nubian Sandstone (NSS) aquifer of northeast Africa is believed to have been recharged in previous wet climatic periods in the Quaternary Period. While this is largely true, we show using the Sinai Peninsula as our test site that the aquifer is locally receiving modern recharge under the current dry climatic conditions. The validity of the advocated model was tested using geophysical (conventional electrical resistivity [ER]) and isotopic (O, H) data, and estimates for modern recharge were obtained using continuous rainfall-runoff modeling over the period 1998-2007. Interpretations of ER profiles are consistent with the presence of unconfined NSS aquifers flooring recharge areas at the foothills of the crystalline basement in Sinai at Baraga (thickness: 20 to >188 m; resistivity: 16-130 ? m) and Zalaga (thickness: 27 to >115 m; resistivity: 3-202 ? m). The isotopic composition ( ?D: -22.7 to -32.8‰; ?18O: -4.47 to -5.22‰) of groundwater samples from wells tapping the NSS aquifer underlying recharge areas is consistent with mixing between two endmembers: (1) fossil groundwater with isotopic compositions similar to those of the Western Desert NSS aquifer ( ?D: -72 to -81‰; ?18O: -10.6 to -11.9‰), and (2) average modern meteoric precipitation ( ?D: -9.84‰; ?18O: -3.48‰) in Sinai, with the latter endmember being the dominant component. A first-order estimate for the average annual modern recharge for the NSS aquifer was assessed at ˜13.0 × 10 6 m 3/yr using the SWAT (Soil Water Assessment Tool) model. Findings bear on the sustainable exploitation of the NSS aquifer, where the aquifer is being locally recharged, and on the exploitation of similar extensive aquifers that were largely recharged in previous wet climatic periods but are still receiving modest modern meteoric contributions.

  6. Seasonal variation in natural recharge of coastal aquifers

    NASA Astrophysics Data System (ADS)

    Mollema, Pauline N.; Antonellini, Marco

    2013-06-01

    Many coastal zones around the world have irregular precipitation throughout the year. This results in discontinuous natural recharge of coastal aquifers, which affects the size of freshwater lenses present in sandy deposits. Temperature data for the period 1960-1990 from LocClim (local climate estimator) and those obtained from the Intergovernmental Panel on Climate Change (IPCC) SRES A1b scenario for 2070-2100, have been used to calculate the potential evapotranspiration with the Thornthwaite method. Potential recharge (difference between precipitation and potential evapotranspiration) was defined at 12 locations: Ameland (The Netherlands), Auckland and Wellington (New Zealand); Hong Kong (China); Ravenna (Italy), Mekong (Vietnam), Mumbai (India), New Jersey (USA), Nile Delta (Egypt), Kobe and Tokyo (Japan), and Singapore. The influence of variable/discontinuous recharge on the size of freshwater lenses was simulated with the SEAWAT model. The discrepancy between models with continuous and with discontinuous recharge is relatively small in areas where the total annual recharge is low (258-616 mm/year); but in places with Monsoon-dominated climate (e.g. Mumbai, with recharge up to 1,686 mm/year), the difference in freshwater-lens thickness between the discontinuous and the continuous model is larger (up to 5 m) and thus important to consider in numerical models that estimate freshwater availability.

  7. Effect of temporally correlated recharge on fluctuations of groundwater levels

    NASA Astrophysics Data System (ADS)

    Zhang, You-Kuan; Li, Zhongwei

    2006-10-01

    The effect of temporally correlated groundwater recharge, R(t), on fluctuations of the hydraulic head, h(t), was investigated with theoretical analyses and numerical simulations. Under an exponentially correlated recharge (ECR) process, analytical solutions for the hydraulic head covariance, Chh, and variance, ?h2, were derived with a linear reservoir model. It was found that Chh and ?h2 are time-dependent or nonstationary and reduce to those derived in a previous study for a white noise recharge (WNR) when the correlation timescale of the recharge process approaches zero. It is also found that ?h2 for ECR is proportional to t2, while that for WNR is proportional to t for a substantial period of time, indicating that h(t) under ECR may vary as a smooth curve with no fractal characteristics (D = 1.0), while h(t) under WNR fluctuates as a Brownian motion (D = 1.5). The theoretical findings were verified by numerical simulations: The power spectra of the simulated heads with a one-dimensional transient groundwater flow model under ECR were shown to have distinct slopes in the log-log plot with D = 1.02. It was emphasized that the effect of temporal correlation in groundwater recharge is to dampen the fluctuations of the head and base flow and that daily groundwater recharge rates may have little temporal correlation in the hydrogeological conditions similar to the Walnut Creek site.

  8. The Policy of "Pumping the Recharge" Is Out of Control

    NASA Astrophysics Data System (ADS)

    Balleau, W. Peter

    2013-01-01

    Hydrogeologists have spent several scientific generations in understanding the source of water to well fields and the effects of wells on the interrelated surface water system. The benchmark is by Theis [1940], who emphasized that some groundwater is initially mined during aquifer development and, after sufficient time, well discharge will be made up by diminution of both rejected recharge and natural discharge. Rejected recharge is water that would reside in the aquifer, except for a lack of space available. Theis advised that a perennial safe yield is equivalent to the amount of rejected recharge and natural discharge that is "feasible to utilize." His term "feasible" may have anticipated many current issues about aquifer sustainability. Papers published this year on the Ogallala aquifer in the central United States and on the global groundwater "footprint" [Scanlon et al., 2012; Gleeson et al., 2012] focus on recharge as an index of sustainability and have been featured in the popular press. However, I argue in this Forum that natural recharge rates alone cannot serve to address the core policy question regarding sustainable aquifer conditions in response to well field stresses. For the sake of users of hydrologic guidance, advisors on this topic may wish to reconsider the safe nature of "pumping the recharge."

  9. Transient Rechargeable Batteries Triggered by Cascade Reactions.

    PubMed

    Fu, Kun; Liu, Zhen; Yao, Yonggang; Wang, Zhengyang; Zhao, Bin; Luo, Wei; Dai, Jiaqi; Lacey, Steven D; Zhou, Lihui; Shen, Fei; Kim, Myeongseob; Swafford, Laura; Sengupta, Louise; Hu, Liangbing

    2015-07-01

    Transient battery is a new type of technology that allows the battery to disappear by an external trigger at any time. In this work, we successfully demonstrated the first transient rechargeable batteries based on dissoluble electrodes including V2O5 as the cathode and lithium metal as the anode as well as a biodegradable separator and battery encasement (PVP and sodium alginate, respectively). All the components are robust in a traditional lithium-ion battery (LIB) organic electrolyte and disappear in water completely within minutes due to triggered cascade reactions. With a simple cut-and-stack method, we designed a fully transient device with an area of 0.5 cm by 1 cm and total energy of 0.1 J. A shadow-mask technique was used to demonstrate the miniature device, which is compatible with transient electronics manufacturing. The materials, fabrication methods, and integration strategy discussed will be of interest for future developments in transient, self-powered electronics. The demonstration of a miniature Li battery shows the feasibility toward system integration for all transient electronics. PMID:26083530

  10. Feasibility of artificial recharge to the 800-foot sand of the Kirkwood Formation in the coastal plain near Atlantic City, New Jersey

    USGS Publications Warehouse

    May, J.E.

    1985-01-01

    Renewed development of the Atlantic City area since the mid-1970 's has increased the demand for water. Increased pumpage from the 800-foot sand of the Kirkwood Formation has reversed an antecedent water-level recovery in this aquifer, thus reducing water in storage and increasing the potential for saltwater intrusion. Practicable approaches to providing a dependable water supply while properly managing withdrawals from the 800-foot sand include development of surface- and ground-water supplies but artificial recharging the 800-foot sand is the principal alternative discussed. Investigation of its feasibility locally included a review of methods of artificial recharge and attendant operational problems, investigation of local hydrogeologic conditions, and collection and interpretation of water-quality data. System design and quality of injected water are important for successful artificial recharge. Mixtures of water from the 800-foot sand and from a representative local public-supply system may become supersaturated with oxygen. Significant temperature differences between two such waters would likely exacerbate that condition. Limited chemical analyses suggest that suspended solids concentration of water from local public supplies may at times be high enough to cause clogging of recharge-well screens. These problems are soluable by appropriate conditioning of recharge water. (USGS)

  11. Prospects for and problems of using light-water supercritical-pressure coolant in nuclear reactors in order to increase the efficiency of the nuclear fuel cycle

    SciTech Connect

    Alekseev, P. N.; Semchenkov, Yu. M.; Sedov, A. A., E-mail: sedov@dhtp.kial.ru; Subbotin, S. A.; Chibinyaev, A. V. [Russian Research Centre Kurchatov Institute (Russian Federation)

    2011-12-15

    Trends in the development of the power sector of the Russian and world power industries both at present time and in the near future are analyzed. Trends in the rise of prices for reserves of fossil and nuclear fuels used for electricity production are compared. An analysis of the competitiveness of electricity production at nuclear power plants as compared to the competitiveness of electricity produced at coal-fired and natural-gas-fired thermal power plants is performed. The efficiency of the open nuclear fuel cycle and various versions of the closed nuclear fuel cycle is discussed. The requirements on light-water reactors under the scenario of dynamic development of the nuclear power industry in Russia are determined. Results of analyzing the efficiency of fuel utilization for various versions of vessel-type light-water reactors with supercritical coolant are given. Advantages and problems of reactors with supercritical-pressure water are listed.

  12. Estimated Infiltration, Percolation, and Recharge Rates at the Rillito Creek Focused Recharge Investigation Site, Pima County, Arizona

    USGS Publications Warehouse

    Hoffmann, John P.; Blasch, Kyle W.; Pool, Don R.; Bailey, Matthew A.; Callegary, James B.

    2007-01-01

    A large fraction of ground water stored in the alluvial aquifers in the Southwest is recharged by water that percolates through ephemeral stream-channel deposits. The amount of water currently recharging many of these aquifers is insufficient to meet current and future demands. Improving the understanding of streambed infiltration and the subsequent redistribution of water within the unsaturated zone is fundamental to quantifying and forming an accurate description of streambed recharge. In addition, improved estimates of recharge from ephemeral-stream channels will reduce uncertainties in water-budget components used in current ground-water models. This chapter presents a summary of findings related to a focused recharge investigation along Rillito Creek in Tucson, Arizona. A variety of approaches used to estimate infiltration, percolation, and recharge fluxes are presented that provide a wide range of temporal- and spatial-scale measurements of recharge beneath Rillito Creek. The approaches discussed include analyses of (1) cores and cuttings for hydraulic and textural properties, (2) environmental tracers from the water extracted from the cores and cuttings, (3) seepage measurements made during sustained streamflow, (4) heat as a tracer and numerical simulations of the movement of heat through the streambed sediments, (5) water-content variations, (6) water-level responses to streamflow in piezometers within the stream channel, and (7) gravity changes in response to recharge events. Hydraulic properties of the materials underlying Rillito Creek were used to estimate long-term potential recharge rates. Seepage measurements and analyses of temperature and water content were used to estimate infiltration rates, and environmental tracers were used to estimate percolation rates through the thick unsaturated zone. The presence or lack of tritium in the water was used to determine whether or not water in the unsaturated zone infiltrated within the past 40 years. Analysis of water-level and temporal-gravity data were used to estimate recharge volumes. Data presented in this chapter were collected from 1999 though 2002. Precipitation and streamflow during this period were less than the long-term average; however, two periods of significant streamflow resulted in recharge?one in the summer of 1999 and the other in the fall/winter of 2000. Flux estimates of infiltration and recharge vary from less than 0.1 to 1.0 cubic meter per second per kilometer of streamflow. Recharge-flux estimates are larger than infiltration estimates. Larger recharge fluxes than infiltration fluxes are explained by the scale of measurements. Methods used to estimate recharge rates incorporate the largest volumetric and temporal scales and are likely to have fluxes from other nearby sources, such as unmeasured tributaries, whereas the methods used to estimate infiltration incorporate the smallest scales, reflecting infiltration rates at individual measurement sites.

  13. Fundamental Concepts of Recharge in the Desert Southwest

    NASA Astrophysics Data System (ADS)

    Flint, A. L.; Flint, L. E.; Blainey, J. B.; Hevesi, J. A.

    2001-12-01

    Recharge in arid basins does not occur in all years or at all locations. To address the temporal and spatial variability of recharge, one must (1) distinguish between recharge and net infiltration, (2) understand travel time in the unsaturated zone, and (3) comprehend the local- and basin-scale deterministic processes and surficial properties that control net infiltration. Net infiltration is the quantity of water that moves below the zone of surface evapotranspiration whereas recharge is the quantity or process of water entering the saturated zone. Under steady-state conditions, net infiltration becomes recharge unless diverted to an area of spring flow, generally by laterally extensive, low-permeability rock. The rate of net infiltration, thickness of unsaturated zone, and the effective porosity of the flow-pathway control travel time through the unsaturated zone. Net infiltration and recharge vary spatially owing to variations in surface microclimates, root zone and unconsolidated material thickness, faults and fractures, and thickness and hydrologic properties of geologic strata in the unsaturated zone. Although temporal fluctuations in net infiltration diminish with depth, resultant recharge is expected to vary on timescales of days to centuries making decadal-scale climate cycles significant to understanding recharge. Results of model simulations of recharge indicate that net infiltration occurs in less than 5 percent of the area of a typical southwest basin and only when the surface-water supply exceeds the storage capacity of the root zone and evapotranspiration over a fixed period of time. The critical components controlling net infiltration and recharge are precipitation, as rain or snow (and snow accumulation and melt); infiltration and water storage capacity of the overlying soil (within the zone of evapotranspiration); potential and actual evapotranspiration; and bedrock permeability. In the desert Southwest, potential evapotranspiration exceeds precipitation on a yearly basis. However, on shorter time scales and in certain areas of a basin, precipitation and (or) snowmelt exceed the infiltration capacity of the soil and becomes runoff or exceed the storage capacity of the soil and becomes runoff in shallow soils or percolates below the root zone in deeper soils. A method to simulate the spatial and temporal variability of net infiltration was developed using a deterministic water-balance model and extensive GIS coverages. The GIS coverages include a digital elevation model and maps of geology, soils, vegetation, precipitation, and air temperature. Other required surficial properties for the model, such as permeability, porosity, and water-retention functions, have been calculated from associated data sets. The deterministic model identifies the areas and climatic conditions that allow for excess water, quantifies the amount of water available either as runoff or in-place recharge, and allows inter-basin comparison of recharge mechanisms (i.e. mountain front, mountain block, ephemeral stream) and potential recharge for current, wetter, and drier climates. Travel time through the unsaturated zone can be estimated if unsaturated zone thickness and permeability data are available. The model, which uses a monthly time step, is being used to evaluate the role of decadal-scale climate cycles (El Niño/La Niña and the Pacific Decadal Oscillation) and recharge potential at a pixel scale (generally 30 - 90 meters) across the entire desert Southwest.

  14. Fossil Fuels.

    ERIC Educational Resources Information Center

    Crank, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with fossil fuels. Some topics covered are historic facts, development of fuels, history of oil production, current and future trends of the oil industry, refining fossil fuels, and environmental problems. Material in each unit may…

  15. The effect of the variation of river water levels on the estimation of groundwater recharge in the Hsinhuwei River, Taiwan

    Microsoft Academic Search

    Jung-Wei Chen; Hsun-Huang Hsieh; Hsin-Fu Yeh; Cheng-Haw Lee

    2010-01-01

    Land subsidence is a serious problem in Taiwan’s Yunlin area due to groundwater overpumping. There are safety risks in the\\u000a high-speed railway structures in the areas of Siluo, Huwei, Tuku, and Yuanchang towns that run from north to south in the\\u000a Yunlin area. Therefore, it is important to increase the groundwater recharge and to remedy the land subsidence in this

  16. Artificial-Recharge Experiments and Operations on the Southern High Plains of Texas and New Mexico

    USGS Publications Warehouse

    Brown, Richmond F.; Signor, Donald C.

    1973-01-01

    Experiments using highly turbid water from playa lakes for injection into the Ogallala Formation have resulted in greatly decreased yield of the recharge wells, Recharge of ground or surface water of good quality has indicated, however, that injection through wells is an effective method of recharging the aquifer. Water that is slightly turbid can be successfully injected for a period of time, but generally results in constantly declining yields and capacity for recharge. Redevelopment through pumping and surging significantly prolongs the life of recharge wells under some conditions. Surface spreading is little practiced on the High Plains, but locally may be a feasible means of artificial recharge.

  17. Design and simulation of lithium rechargeable batteries

    SciTech Connect

    Doyle, C.M.

    1995-08-01

    Lithium -based rechargeable batteries that utilize insertion electrodes are being considered for electric-vehicle applications because of their high energy density and inherent reversibility. General mathematical models are developed that apply to a wide range of lithium-based systems, including the recently commercialized lithium-ion cell. The modeling approach is macroscopic, using porous electrode theory to treat the composite insertion electrodes and concentrated solution theory to describe the transport processes in the solution phase. The insertion process itself is treated with a charge-transfer process at the surface obeying Butler-Volmer kinetics, followed by diffusion of the lithium ion into the host structure. These models are used to explore the phenomena that occur inside of lithium cells under conditions of discharge, charge, and during periods of relaxation. Also, in order to understand the phenomena that limit the high-rate discharge of these systems, we focus on the modeling of a particular system with well-characterized material properties and system parameters. The system chosen is a lithium-ion cell produced by Bellcore in Red Bank, NJ, consisting of a lithium-carbon negative electrode, a plasticized polymer electrolyte, and a lithium-manganese-oxide spinel positive electrode. This battery is being marketed for consumer electronic applications. The system is characterized experimentally in terms of its transport and thermodynamic properties, followed by detailed comparisons of simulation results with experimental discharge curves. Next, the optimization of this system for particular applications is explored based on Ragone plots of the specific energy versus average specific power provided by various designs.

  18. Coupling Stormwater Capture and Managed Aquifer Recharge

    NASA Astrophysics Data System (ADS)

    Beganskas, S.; Hill, C. L.; Fisher, A. T.; Los Huertos, M.

    2013-12-01

    We are quantifying the performance of a system that couples stormwater capture and managed aquifer recharge (MAR). Our field site is a working ranch in the Pajaro Valley, central coastal California, where runoff from ~125 acres of farmed and grazed land is directed into a 2.5-acre infiltration basin. Stormwater captured for MAR at this site would otherwise be routed off the property and eventually into the ocean. We instrumented the site prior to the start of the 2013 water year (1 October 2012) to measure local precipitation, total inflow to the basin, and point-specific infiltration rates across the bottom of the basin using heat as a tracer. We also deployed sediment measurement and collection instruments to quantify the amount, texture, and biochemical nature of sediment accumulating in the basin, and to evaluate associated maintenance requirements for the system. The 2013 water year was relatively dry, with total precipitation less than 50% of the long-term average for this region; most of this precipitation occurred in December 2012. Water level and flow records indicate 17 distinct rain events that generated runoff, most early in the water year. The total inflow to the infiltration basin was 4.1 x 104 m3, equivalent to ~33 ac-ft. During a water year with average precipitation, it appears that this system could collect 80-100 ac-ft of runoff. There was up to 10 cm of sediment accumulation in some parts of the infiltration basin by the end of the rainy season. Sediment samples collected at the end of the season are being processed for analysis of sediment distribution and character. Thermal data are being analyzed to calculate spatial and temporal variations in infiltration rates across the basin. These data will be combined to assess the efficacy of coupling stormwater capture and MAR, and can guide future projects in this region of high groundwater demand and limited resources.

  19. Geochemical Triggers of Arsenic Mobilization during Managed Aquifer Recharge.

    PubMed

    Fakhreddine, Sarah; Dittmar, Jessica; Phipps, Don; Dadakis, Jason; Fendorf, Scott

    2015-07-01

    Mobilization of arsenic and other trace metal contaminants during managed aquifer recharge (MAR) poses a challenge to maintaining local groundwater quality and to ensuring the viability of aquifer storage and recovery techniques. Arsenic release from sediments into solution has occurred during purified recycled water recharge of shallow aquifers within Orange County, CA. Accordingly, we examine the geochemical processes controlling As desorption and mobilization from shallow, aerated sediments underlying MAR infiltration basins. Further, we conducted a series of batch and column experiments to evaluate recharge water chemistries that minimize the propensity of As desorption from the aquifer sediments. Within the shallow Orange County Groundwater Basin sediments, the divalent cations Ca(2+) and Mg(2+) are critical for limiting arsenic desorption; they promote As (as arsenate) adsorption to the phyllosilicate clay minerals of the aquifer. While native groundwater contains adequate concentrations of dissolved Ca(2+) and Mg(2+), these cations are not present at sufficient concentrations during recharge of highly purified recycled water. Subsequently, the absence of dissolved Ca(2+) and Mg(2+) displaces As from the sediments into solution. Increasing the dosages of common water treatment amendments including quicklime (Ca(OH)2) and dolomitic lime (CaO·MgO) provides recharge water with higher concentrations of Ca(2+) and Mg(2+) ions and subsequently decreases the release of As during infiltration. PMID:26057865

  20. Fate of human viruses in groundwater recharge systems

    SciTech Connect

    Vaughn, J.M.; Landry, E.F.

    1980-03-01

    The overall objective of this research program was to determine the ability of a well-managed tertiary effluent-recharge system to return virologically acceptable water to the groundwater aquifer. The study assessed the quality of waters renovated by indigenous recharge operations and investigated a number of virus-soil interrelationships. The elucidation of the interactions led to the establishment of basin operating criteria for optimizing virus removal. Raw influents, chlorinated tertiary effluents, and renovated wastewater from the aquifer directly beneath a uniquely designed recharge test basin were assayed on a weekly basis for the presence of human enteroviruses and coliform bacteria. High concentrations of viruses were routinely isolated from influents but were isolated only on four occasions from tertiary-treated sewage effluents. In spite of the high quality effluent being recharged, viruses were isolated from the groundwater observation well, indicating their ability to penetrate the unsaturated zone. Results of poliovirus seeding experiments carried out in the test basin clearly indicated the need to operate recharge basins at low (e.g. 1 cm/h) infiltration rates in areas having soil types similar to those found at the study site. The method selected for reducing the test basin infiltration rate involved clogging the basin surface with settled organic material from highly turbid effluent. Alternative methods for slowing infiltration rates are discussed in the text.

  1. Within-Day Recharge of Plug-In Hybrid Electric Vehicles: Energy Impact of Public Charging Infrastructure

    SciTech Connect

    Dong, Jing [ORNL; Lin, Zhenhong [ORNL

    2012-01-01

    This paper examines the role of public charging infrastructure in increasing the share of driving on electricity that plug-in hybrid electric vehicles might exhibit, thus reducing their gasoline consumption. Vehicle activity data obtained from a global positioning system tracked household travel survey in Austin, Texas, is used to estimate gasoline and electricity consumptions of plug-in hybrid electric vehicles. Drivers within-day recharging behavior, constrained by travel activities and public charger availability, is modeled. It is found that public charging offers greater fuel savings for hybrid electric vehicles s equipped with smaller batteries, by encouraging within-day recharge, and providing an extensive public charging service is expected to reduce plug-in hybrid electric vehicles gasoline consumption by more than 30% and energy cost by 10%, compared to the scenario of home charging only.

  2. The timing of EV recharging and its effect on utilities

    NASA Astrophysics Data System (ADS)

    Collins, M. M.; Mader, G. H.

    1983-02-01

    The impact of electric vehicles (EVs) on electric utilities will in part depend on when the vehicles are recharged. If electricity pricing practices were guided by time of day, recharging of EVs would occur at late night hours, when demand for electricity for other purposes is low. The peak demand by the year 2000 would then increase by only 400 MW, by comparison with 5700 MW for the case of electricity that is uniformly priced throughout the day. It is further established by the present projections that the oil- and gas-burning component of electrical generation would rise by only 27 percent for the late night-charging case, by contrast to 39 percent for the alternative, late afternoon and early evening recharging.

  3. Sulfone-based electrolytes for aluminium rechargeable batteries.

    PubMed

    Nakayama, Yuri; Senda, Yui; Kawasaki, Hideki; Koshitani, Naoki; Hosoi, Shizuka; Kudo, Yoshihiro; Morioka, Hiroyuki; Nagamine, Masayuki

    2015-02-28

    Electrolyte is a key material for success in the research and development of next-generation rechargeable batteries. Aluminium rechargeable batteries that use aluminium (Al) metals as anode materials are attractive candidates for next-generation batteries, though they have not been developed yet due to the lack of practically useful electrolytes. Here we present, for the first time, non-corrosive reversible Al electrolytes working at room temperature. The electrolytes are composed of aluminium chlorides, dialkylsulfones, and dilutants, which are realized by the identification of electrochemically active Al species, the study of sulfone dependences, the effects of aluminium chloride concentrations, dilutions and their optimizations. The characteristic feature of these materials is the lower chloride concentrations in the solutions than those in the conventional Al electrolytes, which allows us to use the Al metal anodes without corrosions. We anticipate that the sulfone-based electrolytes will open the doors for the research and development of Al rechargeable batteries. PMID:25627398

  4. Optimal energy management for a fuel cell hybrid locomotive

    Microsoft Academic Search

    Zhi-ling Jiang; Wei-rong Chen; Chao-hua Dai; Zhan-li Cheng

    2010-01-01

    In order to save fuel and reduce pollution, the research on fuel cell hybrid electric locomotive has been greatly concerned. This paper presents an analysis of the energy management for hybrid locomotive with two power source, which are fuel cell stack and storage battery, respectively. The battery is used to discharge during high power demand, and recharge through regenerative braking.

  5. Coupling stormwater capture and managed aquifer recharge

    NASA Astrophysics Data System (ADS)

    Beganskas, S.; Fisher, A. T.; Los Huertos, M.; Hill, C. L.

    2014-12-01

    We are evaluating the use of stormwater runoff as a source for managed aquifer recharge (MAR), using data from an operational field site to address two questions: (1) How much stormwater can be captured and infiltrated with this system? (2) What is the impact of sediment delivered to the infiltration basin with the stormwater, and what maintenance would be required to sustain favorable infiltration conditions? Our field site is a working ranch in the Pajaro Valley, central coastal California, where runoff from ~48 ha (120 ac) is directed into a 1-ha (2.5 ac) infiltration basin. We instrumented the site for water years (WY) 2012, 2013, and 2014 to measure local precipitation, total inflow, and sediment accumulation. In WY14, we added a network of instruments that reports some of these data in real time. WY12, WY13, and WY14 were dry, with total precipitation 50%, 70%, and 45% of the regional long-term average, respectively. In WY12, precipitation was spread over many storms, and total inflow was 5,600 m3 (4.5 ac-ft). A series of more intense storms in WY13 delivered 39,000 m3 (31 ac-ft) of total inflow. The driest year of our study so far, WY14, included the most intense rainfall we have recorded, and total inflow was 42,000 m3 (34 ac-ft). These results demonstrate that both precipitation amount and intensity influence how much stormwater runoff is generated. During a wetter year, we expect this system could collect at least 134,000 m2 (100 ac-ft) of runoff. Sediment accumulation in the infiltration basin in WY13 ranged from 0-8 cm, but in WY14 was no greater than 1 cm. As total inflow for these years was similar, sediment load of runoff captured during WY14 was much smaller than that of WY13. Grain size analyses demonstrate that fine material is preferentially delivered to the infiltration basin, while coarser material is removed during transport. These data will be linked to a regional model and used to develop additional stormwater-MAR projects in this area.

  6. Crab Burrows are Important Conduits for Groundwater Recharge in Bangladesh

    NASA Astrophysics Data System (ADS)

    Stahl, M.; Tarek, M. H.; Yeo, D. C.; Badruzzaman, A.; Harvey, C. F.

    2013-12-01

    Recent research suggests that recharge from man-made ponds may stimulate arsenic mobilization within Bangladeshi aquifers. Man-made ponds are widespread throughout Bangladesh and are generally underlain by low permeability clays that could potentially limit flow to the sandy aquifer below if they are not compromised by preferential flow paths. Animal borrows are one common type of preferential flow path through surface clays. Across the Ganges Delta, terrestrial crabs dig borrows, sometimes as long as 10 meters. In our study pond in Munshiganj, Bangladesh we found crab burrows extending through the surficial clays and down into the shallow aquifer spaced approximately every meter. We use these field observations along with a novel, coupled isotope and water balance model to quantify the fluxes into and out of the pond. We show that nearly all of the aquifer recharge from the pond is through crab burrows which have enhanced the hydraulic conductivity of the surficial sediments by several orders of magnitude. In addition we show that the recharging pond water is shifting the solute composition of water beneath the pond. We suggest that, as a result of crab burrows, young ponds may contribute large fluxes of recharge water whereas older ponds may contribute little recharge to the aquifer. All terrestrial crabs have gills that must remain moist to allow for respiration. So, to ensure an uninterrupted water source, their borrows must reach the maximum depth that the water table drops to seasonally after irrigation ceases and before the onset of the monsoon. Once a pond is installed crabs living within the sediments that now make up the new pond bottom would no longer need to construct burrows to ensure a constant supply of water. Over time, burrows that existed prior to pond construction can clog. Water balance data for an old pond at our study site indicates that this pond contributes less recharge than our newly constructed pond.

  7. SPATIAL SCALING OF SURFACE WATER INFILTRATION AND ITS IMPLICATIONS FOR ESTIMATING GROUNDWATER RECHARGE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The GRAPHIC Project has identified priority research topics related to groundwater recharge, discharge, storage, and water quality. This presentation focuses on some physical aspects affecting spatial groundwater recharge estimation and uncertainty associated with spatial variability. Previous wor...

  8. Thin Rechargeable Batteries for CMOS SRAM Memory Protection

    NASA Technical Reports Server (NTRS)

    Crouse, Dennis N.

    1993-01-01

    New rechargeable battery technology is described and compared with classical primary battery back-up of SRAM PC cards. Thin solid polymer electrolyte cells with the thickness of TSOP memory components (1 mm nominal, 1.1 mm max) and capacities of 14 mAh/sq cm can replace coin cells. The SRAM PC cards with permanently installed rechargeable cells and optional electrochromic low battery voltage indicators will free the periodic PC card user from having to 'feed' their PC cards with coin cells and will allow a quick visual check of stored cards for their battery voltage status.

  9. A methodology for making initial estimates of groundwater recharge from groundwater vulnerability mapping

    Microsoft Academic Search

    B. D. R. Misstear; L. Brown; D. Daly

    2009-01-01

    Recharge to an aquifer can be estimated by first calculating the effective rainfall using a soil moisture budgeting technique,\\u000a and then by applying a recharge coefficient to indicate the proportion of this effective rainfall that contributes to groundwater\\u000a recharge. In the Republic of Ireland, the recharge coefficient is determined mainly by the permeability and thickness of the\\u000a superficial deposits (subsoils)

  10. Tracking River Recharge in the Central Valley of California Using Chemical and Isotopic Tracers

    Microsoft Academic Search

    J. E. Moran; B. Hudson; D. Evans; T. Horner; R. Leif; G. F. Eaton

    2003-01-01

    Recharge to alluvial aquifers along the major rivers of the Central Valley of California is influenced by human activity in adjacent urban areas and groundwater basins. Intense pumping of Central Valley aquifers may induce recharge, while slurry walls, emplaced for flood control in densely populated areas, are intended to protect levees by preventing shallow recharge. These large rivers carry distinct

  11. Rapid nutrient load reduction during infiltration of managed aquifer recharge in an agricultural groundwater basin

    E-print Network

    Fisher, Andrew

    Rapid nutrient load reduction during infiltration of managed aquifer recharge in an agricultural California to assess how patterns of infiltration and recharge affect the load of nitrate delivered% to 60% of the nitrate load being removed over the first 6 weeks of managed aquifer recharge operation

  12. Marker species for identifying urban groundwater recharge sources: A review and case study in Nottingham, UK

    Microsoft Academic Search

    Mike H. Barrett; Kevin M. Hiscock; Stephen Pedley; David N. Lerner; John H. Tellam; Mike J. French

    1999-01-01

    Urban environments significantly alter the nature of recharge to underlying aquifers. Direct precipitation is reduced, but additional recharge may result from storm water runoff, mains supply leakage and sewer leakage. If urban aquifers are to be effectively and sustainably managed, it is vital that these recharge sources should be identified and quantified. A sound theoretical approach is the use of

  13. GIS-based recharge estimation by coupling surface–subsurface water balances

    Microsoft Academic Search

    O. Batelaan; F. De Smedt

    2007-01-01

    A spatially distributed water balance model is developed to simulate long-term average recharge depending on land cover, soil texture, topography and hydrometeorological parameters. The model simulates recharge iteratively connected to a groundwater model, such that the recharge estimate is also influenced by the groundwater depth and vice versa. Parameter estimation for the model is performed on the basis of literature

  14. Polymeric metallic electrodes for rechargeable battery applications

    NASA Technical Reports Server (NTRS)

    Somoano, R.

    1982-01-01

    A review is presented on the status of plastic metal electrodes, emphasizing the use of polyacetylene as a prototype polymeric material. The electrochemical characteristics of polyacetylene are examined; and the potential use of this material, as well as other types of plastic metal electrodes, in batteries is evaluated. Several problem areas which must be solved before polyacetylene can be widely used in battery applications are discussed, including the problem of electrolyte stability, the problem that the depth of discharge and the energy density is limited by the metal-semiconductor transition, and also the poor electrochemical performance of impure material.

  15. Moderate temperature rechargeable NaNiS2 cells

    NASA Technical Reports Server (NTRS)

    Abraham, K. M.

    1983-01-01

    A rechargeable sodium battery of the configuration, liquid Na/beta double prime -Al2O3/molten NaAlCl4, NiS2, operating in the temperature range of 170 to 190 C, is described. This battery is capable of delivering or = to 50 W-hr/1b and 1000 deep discharge/charge cycles.

  16. INTRODUCTION Among different types of rechargeable batteries, polymer

    E-print Network

    Bahrami, Majid

    INTRODUCTION Among different types of rechargeable batteries, polymer lithium-ion (Li-ion) cells associated with application of Li-ion batteries in hybrid-electric and plug-in electric vehicles (H International doi:10.4271/2012-01-0334 saepcelec.saejournals.org Temperature Rise in Prismatic Polymer Lithium

  17. Rechargeable lithium battery anodes: alternatives to metallic lithium

    Microsoft Academic Search

    D. Fauteux; R. Koksbang

    1993-01-01

    This review is concerned with alternatives to metallic lithium for use in rechargeable lithium batteries. Emphasis is placed on the use of various materials and combinations of materials in different types of electrodes rather than on the properties of the materials themselves. The review includes carbon based electrodes, alloys, conducting polymers and transition metal compounds. Special consideration is given to

  18. Numerical simulations of brine migration by topographically driven recharge

    Microsoft Academic Search

    David Deming; Jeffrey A. Nunn

    1991-01-01

    The migration of abnormally warm, saline water through the Appalachian basin and North American midcontinent in Paleozoic time has been inferred from fluid inclusion studies, remagnetizations, and widespread potassic alteration. A time-dependent numerical model of fluid, heat and solute transport is used to evaluate the viability of topographically driven recharge as a mechanism for brine migration. The model represents a

  19. Using artificial recharge to restore groundwater \\/ surface water interactions

    Microsoft Academic Search

    A. Menció; E. Vilanova; J. Mas-Pla

    2003-01-01

    Intensive use of ground water resources in small alluvial aquifers usually results in a severe depletion of ground water resources and a reduction of the stream discharge. As a result, a loss of ecological dynamics occurs in the riparian areas. In regions where recharge is quite limited because of climatic factors, those situations may endure as long as a wet

  20. DELINEATING KARST RECHARGE AREAS AT ONONDAGA CAVE STATE PARK

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Onondaga Cave State Park is located in the north central portion of the Ozarks near Leasburg, Missouri. The park is known for two extensive cave systems, Onondaga Cave and Cathedral Cave. Both of these cave systems have active streams (1-2 cfs at baseflow) which have unknown recharge areas. As a man...

  1. Estimating High Plains Aquifer Recharge Using Temperature Probes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The magnitude of recharge through playa wetlands in the High Plains Region of the United States has been debated, but rarely quantified. The ephemeral nature of water in playas makes it difficult and expensive to observe filling and drying/draining cycles. Inexpensive tools are needed to quantify ...

  2. NbSe3 Cathodes For Li Rechargeable Cells

    NASA Technical Reports Server (NTRS)

    Bugga, Ratnakumar V.; Ni, Ching-Ion; Distefano, Salvador; Somoano, Robert B.; Bankston, C. Perry

    1990-01-01

    Report describes experimental studies involving preparation, characterization, and measurements of performance of NbSe3, intended for use as cathode material in lithium rechargeable electrochemical cells. Characteristics superior to those of other intercalating cathode materials, including high volumetric and gravimetric energy densities and ability to sustain discharges at high rates.

  3. Separation composition evaluation in model rechargeable silver-zinc cells

    Microsoft Academic Search

    H. Lewis; S. Henderson; T. Danko

    2001-01-01

    In previous reports, the evaluation of Viskase sausage casings (SCs) in a variety of configurations for silver\\/zinc rechargeable cells has been reported. The conclusions have been that several layers of SC, while providing improved resistance to silver migration acid zinc dendrite growth compared to standard cellophane film, also impart increased internal impedance which leads to faster capacity loss in comparison

  4. Rechargeable lithium batteries in the Navy-policy and protocol

    Microsoft Academic Search

    Julie A. Banner; Clinton S. Winchester

    1996-01-01

    Rechargeable lithium batteries are an emerging technology that is finding widespread use in a myriad of applications. These batteries are supplanting many others because of superior performance characteristics, including high energy density and improved cycle life. The newest model laptop computers, camcorders and cellular phones are using these systems to provide lighter products with longer battery life. Potential military-use scenarios

  5. Technology uses micro-windmills to recharge cell phones

    E-print Network

    Chiao, Jung-Chih

    Technology uses micro-windmills to recharge cell phones A micro-windmill is pictured on the face origami concepts into conventional wafer-scale semiconductor device layouts so "Technology uses micro presentations, which include the micro-windmills, gears, inductors, pop-up switches and grippers. All of those

  6. PRIORITY POLLUTANTS IN THE CEDAR CREEK WASTEWATER RECLAMATION - RECHARGE FACILITIES

    EPA Science Inventory

    The Cedar Creek Wastewater Reclamation Plant (CCWRP) located in Nassau County, NY is a 0.24 cu m/s (5.5 mgd) advanced wastewater treatment (AWT) plant designed to produce a high quality effluent suitable for groundwater recharge. The CCWRP was constructed as a demonstration proje...

  7. Encouraging Revegetation in Australia with a Groundwater Recharge Credit Scheme

    Microsoft Academic Search

    Wendy Proctor; Jeffery D. Connor; John Ward; Darla Hatton MacDonald

    2007-01-01

    This paper describes a comprehensive method to design, test and then implement a Payments for Ecosystem Services (PES) framework to combat the environmental consequences of extensive native vegetation clearance in Australia. Clearing of vegetation, primarily due to the expansion of farming areas, has often resulted in regional dryland and irrigation salinity. The market based approach adopted ? a groundwater recharge

  8. Rechargeable lithium batteries in the Navy -- Policy and protocol

    SciTech Connect

    Banner, J.A.; Winchester, C.S. [Naval Surface Warfare Center, Silver Spring, MD (United States). Carderock Div.

    1996-12-31

    Rechargeable lithium batteries are an emerging technology that is finding widespread use in myriad applications. These batteries are supplanting many others because of superior performance characteristics, including high energy density and improved cycle life. The newest model laptop computers, camcorders and cellular phones are using these systems to provide lighter products with longer battery life. Potential military-use scenarios for this technology range from propulsion power for autonomous unmanned vehicles to power sources for exercise mines. Current battery chemistries that might eventually be replaced by rechargeable lithium batteries include silver-zinc batteries, lithium-thionyl chloride batteries, and possibly lithium thermal batteries. The Navy is developing and implementing a universal test protocol for evaluating the safety characteristics of rechargeable lithium power sources, as discussed by Winchester et al (1995). Test plans based on this protocol are currently being used to evaluate both commercially available and developmental products. In this paper the authors will review the testing protocol that has been developed for evaluating the safety of rechargeable lithium batteries. Relevant data from current test programs will be presented.

  9. Automated Battery Swap and Recharge to Enable Persistent UAV Missions

    E-print Network

    How, Jonathan P.

    Automated Battery Swap and Recharge to Enable Persistent UAV Missions Tuna Toksoz , Joshua Redding introduces a hardware platform for automated battery changing and charging for multiple UAV agents. The automated station holds a buffer of 8 batteries in a novel dual-drum structure that enables a "hot" battery

  10. Climate change effects on vegetation characteristics and groundwater recharge

    NASA Astrophysics Data System (ADS)

    Bartholomeus, R.; Voortman, B.; Witte, J.

    2010-12-01

    Climate change is among the most pressing issues of our time. Increase in temperature, a decrease in summer precipitation and increase in reference evapotranspiration might affect the water balance, freshwater availability and the spatial distribution and type of vegetation. Precipitation and evapotranspiration (ET) largely determine groundwater recharge. Therefore, climate change likely affects both the spatial and temporal freshwater availability for nature conservation, agriculture and drinking water supply. Moreover, in the coastal (dune) areas, the groundwater recharge is crucial to the maintenance of the freshwater bell and the dynamics of the fresh - salt interface. Current knowledge, however, is insufficient to estimate reliably the effects of climate change on future freshwater availability. Future groundwater recharge, the driving force of the groundwater system, can only be assessed if we understand how vegetation responds to changing climatic conditions, and how vegetation feedbacks on groundwater recharge through altered actual ET. Although the reference ET (i.e. the ET of a reference vegetation, defined as a short grassland completely covering the soil and optimally provided by water) is predicted to increase, the future actual ET (i.e. the ET of the actual ‘real’ vegetation under the ‘real’ moisture conditions) is highly unknown. It is the dynamics in the actual ET, however, through which the vegetation feeds back on the groundwater recharge. In an earlier study we showed that increased atmospheric CO2 raises the water use efficiency of plants, thus reducing ET. Here we demonstrate another important vegetation feedback in dune systems: the fraction of bare soil and non-rooting species (lichens and mosses) in the dune vegetation will increase when, according to the expectations, summers become drier. From our calculations it appeared that on south slopes of dunes, which receive more solar radiation and are warmer than north facing surfaces, the fraction of vascular plants may drop from 70 to 20 percent in the future (2050) climate due to increased moisture deficits. ET of bare soil and non-rooting species is much lower than that of vascular plants and thus the vegetation composition feeds back on the soil moisture conditions. Knowledge on such feedback mechanisms is indispensable in the analysis of climate change effects on the future groundwater recharge. Important questions are how, in the course of time, climate change will affect both groundwater table depth and dynamics, and how water management could adapt to these changes. We pursue a dynamic modeling approach that takes account of the interacting processes in the soil-plant-atmosphere system, including feedback mechanisms of the vegetation. This allows us to analyze climate change effects on groundwater recharge and thus future freshwater availability.

  11. Stability, compatibility and related problems of additives in Navy distillate fuels derived from lower quality feedstocks. An interim report

    Microsoft Academic Search

    D. W. Brinkman; K. Q. Stirling; J. W. Goetzinger; M. E. Hefner; E. J. Zagula

    1985-01-01

    This report describes the initial phases of a study co-sponsored by DOE and the US Navy to determine which antioxidant additives are most effective in delaying fuel degradation in a variety of straight-run middle distillate\\/light cycle oil blends. In this study, straight-run middle distillate products were blended with catalytically cracked products at ratios of 85:15, 70:30; and 60:40, respectively. All

  12. Groundwater recharge measurements in gravel sandy sediments with monolith lysimeter

    NASA Astrophysics Data System (ADS)

    Bracic Zeleznik, Branka; Souvent, Petra; Cencur Curk, Barbara; Zupanc, Vesna

    2013-04-01

    Ljubljana field aquifer is recharging through precipitation and the river Sava, which has the snow-rain flow regime. The sediments of the aquifer have high permeability and create fast flow as well as high regeneration of the dynamic reserves of the Ljubljana field groundwater resource. Groundwater recharge is vulnerable to climate change and it is very important for drinking water supply management. Water stored in the soil and less permeable layers is important for water availability under extreme weather conditions. Measurements of water percolation through the vadose zone provide important input for groundwater recharge assessment and estimation of contaminant migration from land surface to the groundwater. Knowledge of the processes governing groundwater recharge in the vadose zone is critical to understanding the overall hydrological cycle and quantifying the links between land uses and groundwater quantity and quality. To improve the knowledge on water balance for Ljubljana field aquifer we establish a lysimeter for measurements of processes in unsaturated zone in well field Kle?e. The type of lysimeter is a scientific lysimeter designed to solve the water balance equation by measuring the mass of the lysimeter monolith as well as that of outflow tank with high accuracy and high temporal resolution. We evaluated short period data, however the chosen month demonstrates weather extremes of the local climate - relatively dry periods, followed by high precipitation amount. In time of high water usage of vegetation only subsequent substantial precipitation events directly results in water flow towards lower layers. At the same time, gravely layers of the deeper parts of the unsaturated zone have little or no capacity for water retention, and in the event that water line leaves top soil, water flow moves downwards fairly quickly. On one hand this confirms high recharge capacity of Ljubljana field aquifer from precipitation on green areas; on the other hand it shows tremendous susceptibility of the aquifer to pollution and reinforces the position of groundwater protection zones above aquifer.

  13. 1/14/14 Technologyuses micro-windmills to recharge cell phones www.rdmag.com/print/news/2014/01/technology-uses-micro-windmills-recharge-cell-phones 1/3

    E-print Network

    Chiao, Jung-Chih

    1/14/14 Technologyuses micro-windmills to recharge cell phones www.rdmag.com/print/news/2014/01/technology-uses-micro-windmills-recharge-cell-phones 1/3 One of Smitha Rao's micro- windmills is placed here uses micro-windmills to recharge cell phones Technology uses micro-windmills to recharge cell phones

  14. 3/4/2014 Mini Windmills Can Recharge Cell Phones http://www.cemag.us/news/2014/01/mini-windmills-can-recharge-cell-phones#.UxY6ePldWa8 1/9

    E-print Network

    Chiao, Jung-Chih

    3/4/2014 Mini Windmills Can Recharge Cell Phones http://www.cemag.us/news/2014/01/mini-windmills-can-recharge-cell-phones'S GUIDE LOG IN REGISTERFIND MY COMPANY News Mini Windmills Can Recharge Cell Phones ADVERTISEMENT Mon, 01 energy and may become an innovative solution to cell phone batteries constantly in need of recharging

  15. Transient heat and mass transfer modeling aspects of rechargeable lithium/polymer electrolyte batteries

    NASA Astrophysics Data System (ADS)

    Fellner, Joseph Phillip

    Rechargeable lithium/polymer electrolyte batteries have the potential for higher energy density than existing lithium-ion type batteries. However, lithium/polymer batteries have limited cycle life. Discharge capacity is extremely sensitive to temperature and discharge rate, and potential safety problems exist and are related to battery temperature distribution. This dissertation addresses several of these battery performance limiting issues by modeling fundamental heat and mass transfer processes that occur during lithium/polymer battery operation. A transient, three dimensional heat transfer and generation model was developed and applied to a single lithium/poly(ethylene oxide)/titanium disulfide cell. This model can be used to predict the cell temperatures for a new type of thermal battery, namely, a lithium/polymer thermal battery. Fundamental processes that occur at the lithium/polymer electrolyte interface were determined and a diffusion-limited reaction model was proposed to explain the interfacial resistance growth with time. The addition of alumina to the poly(ethylene oxide) polymer electrolyte reduces the magnitude and growth rate of the interfacial resistance mainly by serving as a diluent. The cell voltage and discharge capacity as a function of discharge rate for a room temperature rechargeable lithium/polymer electrolyte/lithium manganese oxide cell were accurately simulated by a simple diffusion-limited reaction model and by a transient, two-dimensional mass transfer and generation model. The importance of using the intrinsic lithium chemical diffusion coefficient in modeling lithium insertion cathode materials is addressed.

  16. A Fully Integrated Wireless System for Intracranial Direct Cortical Stimulation, Real-Time Electrocorticography Data Transmission, and Smart Cage for Wireless Battery Recharge

    PubMed Central

    Piangerelli, Marco; Ciavarro, Marco; Paris, Antonino; Marchetti, Stefano; Cristiani, Paolo; Puttilli, Cosimo; Torres, Napoleon; Benabid, Alim Louis; Romanelli, Pantaleo

    2014-01-01

    Wireless transmission of cortical signals is an essential step to improve the safety of epilepsy procedures requiring seizure focus localization and to provide chronic recording of brain activity for Brain Computer Interface (BCI) applications. Our group developed a fully implantable and externally rechargeable device, able to provide wireless electrocorticographic (ECoG) recording and cortical stimulation (CS). The first prototype of a wireless multi-channel very low power ECoG system was custom-designed to be implanted on non-human primates. The device, named ECOGIW-16E, is housed in a compact hermetically sealed Polyether ether ketone (PEEK) enclosure, allowing seamless battery recharge. ECOGIW-16E is recharged in a wireless fashion using a special cage designed to facilitate the recharge process in monkeys and developed in accordance with guidelines for accommodation of animals by Council of Europe (ETS123). The inductively recharging cage is made up of nylon and provides a thoroughly novel experimental setting on freely moving animals. The combination of wireless cable-free ECoG and external seamless battery recharge solves the problems and shortcomings caused by the presence of cables leaving the skull, providing a safer and easier way to monitor patients and to perform ECoG recording on primates. Data transmission exploits the newly available Medical Implant Communication Service band (MICS): 402–405?MHz. ECOGIW-16E was implanted over the left sensorimotor cortex of a macaca fascicularis to assess the feasibility of wireless ECoG monitoring and brain mapping through CS. With this device, we were able to record the everyday life ECoG signal from a monkey and to deliver focal brain stimulation with movement elicitation. PMID:25202300

  17. A fully integrated wireless system for intracranial direct cortical stimulation, real-time electrocorticography data transmission, and smart cage for wireless battery recharge.

    PubMed

    Piangerelli, Marco; Ciavarro, Marco; Paris, Antonino; Marchetti, Stefano; Cristiani, Paolo; Puttilli, Cosimo; Torres, Napoleon; Benabid, Alim Louis; Romanelli, Pantaleo

    2014-01-01

    Wireless transmission of cortical signals is an essential step to improve the safety of epilepsy procedures requiring seizure focus localization and to provide chronic recording of brain activity for Brain Computer Interface (BCI) applications. Our group developed a fully implantable and externally rechargeable device, able to provide wireless electrocorticographic (ECoG) recording and cortical stimulation (CS). The first prototype of a wireless multi-channel very low power ECoG system was custom-designed to be implanted on non-human primates. The device, named ECOGIW-16E, is housed in a compact hermetically sealed Polyether ether ketone (PEEK) enclosure, allowing seamless battery recharge. ECOGIW-16E is recharged in a wireless fashion using a special cage designed to facilitate the recharge process in monkeys and developed in accordance with guidelines for accommodation of animals by Council of Europe (ETS123). The inductively recharging cage is made up of nylon and provides a thoroughly novel experimental setting on freely moving animals. The combination of wireless cable-free ECoG and external seamless battery recharge solves the problems and shortcomings caused by the presence of cables leaving the skull, providing a safer and easier way to monitor patients and to perform ECoG recording on primates. Data transmission exploits the newly available Medical Implant Communication Service band (MICS): 402-405?MHz. ECOGIW-16E was implanted over the left sensorimotor cortex of a macaca fascicularis to assess the feasibility of wireless ECoG monitoring and brain mapping through CS. With this device, we were able to record the everyday life ECoG signal from a monkey and to deliver focal brain stimulation with movement elicitation. PMID:25202300

  18. Alternative fuels

    Microsoft Academic Search

    Rezendes

    1991-01-01

    This paper reports that in reviewing programs in Brazil, Canada, and New Zealand to encourage the use of alternative fuels, GAO found that each country was able, to some extent, to get motorists to use alternative fuels, although not without problems and setbacks. GAO also found remarkable consistency in the experiences and lessons reported. GAO testified that the experiences of

  19. Competitive systems - Ambient temperature rechargeable batteries

    NASA Astrophysics Data System (ADS)

    dell, R. M.

    Recent in designs of aqueous electrolyte secondary batteries are presented. Operation principles, performance characteristics, and applications of various types of lead/acid batteries, alkaline electrolyte batteries, flow batteries, and battery/fuel cell hybrids (such as metal/air and hydrogen/metal oxide systems) are discussed. Consideration is given to the relative importance of such battery parameters as deep discharge capability, freedom from maintenance, shelf life, and cost, depending upon the specific application.

  20. Unitized regenerative fuel cell systems

    Microsoft Academic Search

    F Mitlitsky; T M Molter; B Myers; A H Weisberg

    1998-01-01

    Energy storage systems with extremely high specific energy (>400 Wh\\/kg) have been designed;\\u000athat use lightweight pressure vessels to contain the gases generated by reversible (unitized);\\u000aregenerative fuel cells (URFCs).[1] URFC systems are being designed and developed for a variety;\\u000aof applications, including high altitude long endurance (HALE) solar rechargeable aircraft (SRA),;\\u000azero emission vehicles (ZEVs), hybrid energy storage\\/propulsion systems

  1. Combined estimation of specific yield and natural recharge in a semi-arid groundwater basin with irrigated agriculture

    Microsoft Academic Search

    J. C. Maréchal; B. Dewandel; S. Ahmed; L. Galeazzi; F. K. Zaidi

    2006-01-01

    A water budget approach is developed to jointly estimate specific yield and natural recharge in an unconfined aquifer with significant seasonal water table fluctuations. Water table fluctuations are due to distinct seasonality in groundwater recharge. The separation of the hydrologic year into two (or more) extended seasons of recharge (wet season) and no-recharge (dry season) with accompanying changes in water

  2. Monitoring induced denitrification in an artificial aquifer recharge system.

    NASA Astrophysics Data System (ADS)

    Grau-Martinez, Alba; Torrentó, Clara; Folch, Albert; Domènech, Cristina; Otero, Neus; Soler, Albert

    2014-05-01

    As demands on groundwater increase, artificial recharge is becoming a common method for enhancing groundwater supply. The Llobregat River is a strategic water supply resource to the Barcelona metropolitan area (Catalonia, NE Spain). Aquifer overexploitation has leaded to both a decrease of groundwater level and seawater intrusion, with the consequent deterioration of water quality. In the middle section of the aquifer, in Sant Vicenç del Horts, decantation and infiltration ponds recharged by water from the Llobregat River (highly affected from wastewater treatment plant effluents), were installed in 2007, in the framework of the ENSAT Life+ project. At the bottom of the infiltration pond, a vegetal compost layer was installed to promote the growth of bacteria, to induce denitrification and to create favourable conditions for contaminant biodegradation. This layer consists on a mixture of compost, aquifer material, clay and iron oxide. Understanding the fate of contaminants, such as nitrate, during artificial aquifer recharge is required to evaluate the impact of artificial recharge in groundwater quality. In order to distinguish the source of nitrate and to evaluate the capability of the organic reactive layer to induce denitrification, a multi-isotopic approach coupled with hydrogeochemical data was performed. Groundwater samples, as well as river samples, were sampled during artificial and natural recharge periods. The isotopic analysis included: ?15N and ?18O of dissolved nitrate, ?34S and ?18O of dissolved sulphate, ?13C of dissolved inorganic carbon, and ?2H and ?18O of water. Dissolved nitrate isotopic composition (?15NNO3 from +9 to +21 o and ?18ONO3 from +3 to +16 ) demonstrated that heterotrophic denitrification induced by the reactive layer was taking place during the artificial recharge periods. An approximation to the extent of nitrate attenuation was calculated, showing a range between 95 and 99% or between 35 and 45%, by using the extreme literature ?N values of -4o and -22o respectively (Aravena and Robertson, 1998; Pauwels et al., 2000). Ongoing denitrification batch experiments will allow us to determine the specific nitrogen and oxygen isotopic fractionation induced by the organic reactive layer, in order to estimate more precisely the extent of denitrification during artificial aquifer recharge. These results confirmed that the reactive layer induces denitrification in the recharge ponds area, proving the usefulness of an isotopic approach to characterize water quality improvement occurring during artificial aquifer recharge. References 1. Aravena, R., Robertson, W.D., 1998. Use of multiple isotope tracers to evaluate denitrification in ground water: Study of nitrate from a large-flux septic system plume. Ground Water, 36(6): 975-982. 2. Pauwels, H., J.C., Kloppmann, W., 2000. Denitrification and mixing in a schist aquifer: Influence on water chemistry and isotopes. Chemical Geology, 168(3-4): 307-324. Acknowledgment This study was supported by the projects CGL2011-29975-C04-01 from the Spanish Government, 2009SGR-00103 from the Catalan Government and ENPI/2011/280-008 from the European Commission. Please fill in your abstract text.

  3. The problems of mass transfer and formation of deposits of corrosion products on fuel assemblies of a VVER-1200 reactor

    NASA Astrophysics Data System (ADS)

    Rodionov, Yu. A.; Kritskii, V. G.; Berezina, I. G.; Gavrilov, A. V.

    2014-03-01

    On the basis of examination of materials published both in Russia and abroad, as well as their own investigations, the authors explain the reasons for the occurrence of such effects as AOA (Axial Offset Anomalies) and an increase in the coolant pressure difference in the core of nuclear reactors of the VVER type. To detect the occurrence of the AOA effect, the authors suggest using the specific activity of 58Co in the coolant. In the VVER-1200 design the thermohydraulic regime for fuel assemblies in the first year of their service life involves slight boiling of the coolant in the upper part of the core, which may induce the occurrence of the AOA effect, intensification of corrosion of fuel claddings, and abnormal increase in deposition of corrosion products. Radiolysis of the water coolant in the boiling section (boiling in pores of deposits) may intensify not only general corrosion but also a localized (nodular) one. As a result of intensification of the corrosion processes and growth of deposits, deterioration of the radiation situation in the rooms of the primary circuit of a VVER-1200 reactor as compared to that at nuclear power plants equipped with reactors of the VVER-1000 type is possible. Recommendations for preventing the AOA effect at nuclear power plants with VVER-1200 reactors on the matter of the direction of further investigations are made.

  4. Storage of surface flows through groundwater recharge

    Microsoft Academic Search

    M C Chaturvedi; V K Srivastava

    1985-01-01

    The Ganga basin in India has a serious problem of water availability. The basin, which is only one twelfth of the United States\\u000a in area, has a population greater than the totalus population, and is increasing at a rate of 2·5% per annum. About 77% of the population is engaged in agriculture which is\\u000a totally dependent on irrigation, as almost

  5. Modelling perched river recharge to the Wairau aquifer, New Zealand

    NASA Astrophysics Data System (ADS)

    Wöhling, Thomas; Gosses, Moritz; Wilson, Scott; Davidson, Peter

    2015-04-01

    The Wairau Aquifer in Marlborough, New Zealand, consists of coarse, high-conductive alluvial gravels and is almost exclusively recharged by surface water from the braided Wairau River. Recent experimental evidence suggests that the river is perched in the upstream recharge region of the aquifer. The aquifer serves as the major drinking water resource for the city of Blenheim and the surrounding settlements on the Wairau Plain and thus is a key natural resource for the region. To ensure the sustainable management of the resource, it is essential to better understand the limits and the mechanics of the recharge mechanism. One efficient way to test hypotheses of the mechanisms for river-groundwater exchange fluxes between the Wairau river and aquifer is by data integration into numerical models that mimic the flow regime of the coupled hydrological system. For that purpose, a Modflow model for the Wairau Aquifer was to set up and calibrated under summer conditions when the flow in the river is low and the aquifer is most vulnerable to over-allocation. The model is constrained by knowledge about the hydrogeological settings as well as observations of groundwater levels, river and spring flow gaugings, and analysis of aquifer pumping tests. Both historic and more recent concurrent river flow measurements under low flow conditions suggest that approximately 7-8 m³/s is recharged into the aquifer along the upper and middle reaches, at least partly under perched conditions. At the eastern side of the aquifer, a small proportion of that water flows back into the river, whereas a greater proportion emerges in springs. Spring creek is the largest spring with an estimated mean flow of 4.0 m³/s. This flow rate is vulnerable to an excessive decline in groundwater levels. The simulations with the calibrated flow model fit well to the observations of current mean groundwater heads as well as to mean Wairau river and Spring creek flows. Modeling results suggest a large spatial variability of recharge fluxes along the river. Model calibration to the different data types turned out to be challenging and required a powerful multiobjective optimization approach and parameter regularization techniques. The proposed approach yielded parsimonious parameter fields with relatively low variability that are generally in agreement with estimations from bore-log analysis. First steps were taken to simulate the dynamics of the river recharge mechanisms and to evaluate the current monitoring scheme with respect to the utility of individual observations. Transient simulations under different flow regimes will improve the knowledge about the Wairau river-groundwater exchange fluxes and thus assist in providing more confidence in managing the valuable resource.

  6. Estimation of groundwater recharge using a GIS-based distributed water balance model in Dire Dawa, Ethiopia

    Microsoft Academic Search

    Ketema Tilahun; Broder J. Merkel

    2009-01-01

    Sustainable groundwater management requires knowledge of recharge. Recharge is also an important parameter in groundwater\\u000a flow and transport models. Spatial variation in recharge due to distributed land-us.e, soil texture, topography, groundwater\\u000a level, and hydrometeorological conditions should be accounted for in recharge estimation. However, conventional point-estimates\\u000a of recharge are not easily extrapolated or regionalized. In this study, a spatially distributed water

  7. Managed Aquifer Recharge in Italy: present and prospects.

    NASA Astrophysics Data System (ADS)

    Rossetto, Rudy

    2015-04-01

    On October the 3rd 2014, a one-day Workshop on Managed Aquifer Recharge (MAR) experiences in Italy took place at the GEOFLUID fair in Piacenza. It was organized within the framework of the EIP AG 128 - MAR Solutions - Managed Aquifer Recharge Strategies and Actions and the EU FPVII MARSOL. The event aimed at showcasing present experiences on MAR in Italy while at the same time starting a network among all the Institutions involved. In this contribution, we discuss the state of MAR application in Italy and summarize the outcomes of that event. In Italy aquifer recharge is traditionally applied unintentionally, by increasing riverbank filtration or because of excess irrigation. A certain interest for artificial recharge of aquifers arose at the end of the '70s and the beginning of the '80s and tests have been carried out in Tuscany, Veneto and Friuli Venezia Giulia. During the last years some projects on aquifer recharge were co-financed by the European Commission mainly through the LIFE program. Nearly all of them use the terminology of artificial recharge instead of MAR. They are: - TRUST (Tool for regional - scale assessment of groundwater storage improvement in adaptation to climate change, LIFE07 ENV/IT/000475; Marsala 2014); - AQUOR (Implementation of a water saving and artificial recharging participated strategy for the quantitative groundwater layer rebalance of the upper Vicenza's plain - LIFE 2010 ENV/IT/380; Mezzalira et al. 2014); - WARBO (Water re-born - artificial recharge: innovative technologies for the sustainable management of water resources, LIFE10 ENV/IT/000394; 2014). While the TRUST project dealt in general with aquifer recharge, AQUOR and WARBO focused essentially on small scale demonstration plants. Within the EU FPVII-ENV-2013 MARSOL project (Demonstrating Managed Aquifer Recharge as a Solution to Water Scarcity and Drought; 2014), a dedicated monitoring and decision support system is under development to manage recharge at a large scale riverbank filtration plant, worth 15 Mm3/year in Lucca (Tuscany; Borsi et al. 2014). In 2014, the Regional Authority of Emilia Romagna started a pilot on the Marecchia River fan using a recharge basin to alleviate water scarcity in the Rimini area as results of drought periods (Severi et al. 2014). To apply MAR techniques on a large scale is of particular interest the possibility to allow farmer's associations or drainage consortiums to play an important role in storing excess rainfall water in aquifers. Few hectares of land in rural areas may be dedicated to MAR plants, transforming a traditionally water consumer sector in one preserving it - opportunities are then linked to the provision of water related ecosystem services. Aquifer recharge is allowed in Italy only since September 2013, but still a regulatory framework is missing. Hopefully, this regulatory scheme will benefit from previous and on-going experiences. Dissemination of MAR scientific findings and technical know-how among governing authorities and the general public is crucial for the application of MAR techniques. Fundings for setting up new MAR plants may be available at national level. At the same time, lack of knowledge at intermediate governing bodies level is preventing the application of these techniques (i.e. building of small dams is favored although less convenient by several points of view in respect of MAR plants). Finally, it is of outmost importance to define which are the financial instruments to sustain these water infrastructures, so to guarantee not only their set up, but also routinely operations, opening as such a new market in the water sector. Acknowledgments This paper is co-financed within the framework of the EU FP7-ENV-2013-WATER-INNO-DEMO MARSOL (Grant Agreement n. 619120). References Borsi, I., Mazzanti, G., Barbagli, A., Rossetto, R., 2014. The riverbank filtration plant in S. Alessio (Lucca): monitoring and modeling activity within EU the FP7 MARSOL project. Acque Sotterranee - Italian Journal of Groundwater, Vol. 3, n. 3/137 Marsala, V. (2014). LIFE+ TRUST project: too

  8. Energy harvesting by implantable abiotically catalyzed glucose fuel cells

    Microsoft Academic Search

    S. Kerzenmacher; J. Ducrée; R. Zengerle; F. von Stetten

    2008-01-01

    Implantable glucose fuel cells are a promising approach to realize an autonomous energy supply for medical implants that solely relies on the electrochemical reaction of oxygen and glucose. Key advantage over conventional batteries is the abundant availability of both reactants in body fluids, rendering the need for regular replacement or external recharging mechanisms obsolete. Implantable glucose fuel cells, based on

  9. Hybrid system for rechargeable magnesium battery with high energy density.

    PubMed

    Chang, Zheng; Yang, Yaqiong; Wang, Xiaowei; Li, Minxia; Fu, Zhengwen; Wu, Yuping; Holze, Rudolf

    2015-01-01

    One of the main challenges of electrical energy storage (EES) is the development of environmentally friendly battery systems with high safety and high energy density. Rechargeable Mg batteries have been long considered as one highly promising system due to the use of low cost and dendrite-free magnesium metal. The bottleneck for traditional Mg batteries is to achieve high energy density since their output voltage is below 2.0 V. Here, we report a magnesium battery using Mg in Grignard reagent-based electrolyte as the negative electrode, a lithium intercalation compound in aqueous solution as the positive electrode, and a solid electrolyte as a separator. Its average discharge voltage is 2.1 V with stable discharge platform and good cycling life. The calculated energy density based on the two electrodes is high. These findings open another door to rechargeable magnesium batteries. PMID:26173624

  10. Novel electrolyte chemistries for Mg-Ni rechargeable batteries.

    SciTech Connect

    Garcia-Diaz, Brenda (Savannah River National Laboratory); Kane, Marie; Au, Ming (Savannah River National Laboratory)

    2010-10-01

    Commercial hybrid electric vehicles (HEV) and battery electric vehicles (BEV) serve as means to reduce the nation's dependence on oil. Current electric vehicles use relatively heavy nickel metal hydride (Ni-MH) rechargeable batteries. Li-ion rechargeable batteries have been developed extensively as the replacement; however, the high cost and safety concerns are still issues to be resolved before large-scale production. In this study, we propose a new highly conductive solid polymer electrolyte for Mg-Ni high electrochemical capacity batteries. The traditional corrosive alkaline aqueous electrolyte (KOH) is replaced with a dry polymer with conductivity on the order of 10{sup -2} S/cm, as measured by impedance spectroscopy. Several potential novel polymer and polymer composite candidates are presented with the best-performing electrolyte results for full cell testing and cycling.

  11. Zinc electrode and rechargeable zinc-air battery

    DOEpatents

    Ross, Jr., Philip N. (Kensington, CA)

    1989-01-01

    An improved zinc electrode is disclosed for a rechargeable zinc-air battery comprising an outer frame and a porous foam electrode support within the frame which is treated prior to the deposition of zinc thereon to inhibit the formation of zinc dendrites on the external surface thereof. The outer frame is provided with passageways for circulating an alkaline electrolyte through the treated zinc-coated porous foam. A novel rechargeable zinc-air battery system is also disclosed which utilizes the improved zinc electrode and further includes an alkaline electrolyte within said battery circulating through the passageways in the zinc electrode and an external electrolyte circulation means which has an electrolyte reservoir external to the battery case including filter means to filter solids out of the electrolyte as it circulates to the external reservoir and pump means for recirculating electrolyte from the external reservoir to the zinc electrode.

  12. Intrinsically safe 5-V, 4-A rechargeable power supply

    SciTech Connect

    Sammarco, J.J.

    1989-01-01

    The author reports on a regulated, intrinsically safe, rechargeable power supply for portable electronic equipment for underground use. The regulated output is ideal for microprocessor power requirements and is suited for operation in hazardous environments. Two rechargeable, sealed batteries are contained within the power supply. Provisions are made to use an external source of power if these batteries fail. Provisions are also made to charge these internal batteries when needed. The circuit is composed of three main circuits: the main regulator circuit, the input protection circuit, and the output protection circuit. The main regulator circuit provides remote voltage sensing, current sensing, fault monitoring, and internal thermal protection. The input protection circuit checks for excessive input current and low battery conditions. The output protection circuit contains two overvoltage detection devices. Schematics, a parts list, and a calibration procedure are provided.

  13. Evaluation of slurry characteristics for rechargeable lithium-ion batteries

    SciTech Connect

    Cho, Ki Yeon [Research Institute of Advanced Materials (RIAM), Department of Materials Science and Engineering, Seoul National University, Daehak-Dong, Gwanak-Gu, Seoul (Korea, Republic of); Kwon, Young Il [SAMSUNG SDI, 428-5 Gongse-dong, Giheung-gu, Yongin, Kyunggi-do (Korea, Republic of); Youn, Jae Ryoun, E-mail: jaeryoun@snu.ac.kr [Research Institute of Advanced Materials (RIAM), Department of Materials Science and Engineering, Seoul National University, Daehak-Dong, Gwanak-Gu, Seoul (Korea, Republic of); Song, Young Seok, E-mail: ysong@dankook.ac.kr [Department of Fiber System Engineering, Dankook University, 126 Jukjeon-dong, Suji-gu, Yongin-si, Gyeonggi-do (Korea, Republic of)

    2013-08-01

    Graphical abstract: - Highlights: • Lithium-ion battery slurries are prepared for rechargeable batteries. • The dispersion state of slurry constituents is identified. • Thermal, morphological, rheological, and electrical properties of slurries are analyzed. - Abstract: A multi-component slurry for rechargeable batteries is prepared by dispersing LiCoO{sub 2}, conductive additives, and polymeric binders in a solvent. The physical properties, including rheological, morphological, electrical, and spectroscopic features of battery slurries are investigated. The relationship between the measured physical properties and the internal structure of the slurry is analyzed. It is found that the rheological behavior of the slurry is determined by the interaction of active materials and binding materials (e.g., network structure) and that the dispersion state of conductive additives (e.g., agglomeration) also depends on the binder–carbon interaction.

  14. Recharging behavior of nitrogen-centers in ZnO

    SciTech Connect

    Philipps, Jan M., E-mail: jan.m.philipps@physik.uni-giessen.de; Meyer, Bruno K.; Hofmann, Detlev M. [I. Physikalisches Institut, Justus-Liebig-Universitaet Giessen, D-35392 Giessen (Germany); Stehr, Jan E.; Buyanova, Irina [Department of Physics, Chemistry and Biology, Linkoeping University, 58183 Linkoeping (Sweden); Tarun, Marianne C.; McCluskey, Matthew D. [Department of Physics and Astronomy and Materials Science Program, Washington State University, Pullman, Washington 99164-2814 (United States)

    2014-08-14

    Electron Paramagnetic Resonance was used to study N{sub 2}-centers in ZnO, which show a 5-line spectrum described by the hyperfine interaction of two nitrogen nuclei (nuclear spin I?=?1, 99.6% abundance). The recharging of this center exhibits two steps, a weak onset at about 1.4?eV and a strongly increasing signal for photon energies above 1.9?eV. The latter energy coincides with the recharging energy of N{sub O} centers (substitutional nitrogen atoms on oxygen sites). The results indicate that the N{sub 2}-centers are deep level defects and therefore not suitable to cause significant hole-conductivity at room temperature.

  15. Estimating recharge at Yucca Mountain, Nevada, USA: comparison of methods

    Microsoft Academic Search

    Alan L. Flint; Lorraine E. Flint; Edward M. Kwicklis; June T. Fabryka-Martin; Gudmundur S. Bodvarsson

    2002-01-01

    .   Obtaining values of net infiltration, groundwater travel time, and recharge is necessary at the Yucca Mountain site, Nevada,\\u000a USA, in order to evaluate the expected performance of a potential repository as a containment system for high-level radioactive\\u000a waste. However, the geologic complexities of this site, its low precipitation and net infiltration, with numerous mechanisms\\u000a operating simultaneously to move water

  16. Performance of Bellcore's plastic rechargeable Li-ion batteries

    Microsoft Academic Search

    J.-M. Tarascon; A. S. Gozdz; C. Schmutz; F. Shokoohi; P. C. Warren

    1996-01-01

    Polymer Li-ion batteries have received little attention mainly because of the unproved, but long-held belief, that safe Li polymer-batteries can be developed. Herein we review the development of the first practical plastic rechargeable Li-ion battery. Bellcore's new plastic Li-ion cell compares well with its liquid Li-ion counterparts in terms of volumetric energy density, cycle life, power rate, while offering several

  17. Polymer Considerations in Rechargeable Lithium Ion Plastic Batteries

    Microsoft Academic Search

    Antoni S. Gozdz; Jean-Marie Tarascon; Caroline N. Schmutz; Paul Warren; O. S. Gebizlioglu; F. Shokoohi

    1995-01-01

    A series of polymers have been investigated in order to determine their suitability as ionically conductive binders of the active electrode materials and as hybrid electrolyte matrices in plastic lithium ion rechargeable batteries. Hybrid electrolyte films used in this study have been prepared by solvent casting using a 1:1 w\\/w mixture of the matrix polymer with 1 M LiPF6 in

  18. Power sources and electrical recharging strategies for implantable medical devices

    Microsoft Academic Search

    Xiaojuan Wei; Jing Liu

    2008-01-01

    Implantable medical devices (IMDs) are critically requested for the survival of patients subject to certain serious diseases\\u000a such as bradycardia, fibrillation, diabetes, and disability, etc. Appropriate working of an active implantable medical device\\u000a (IMD) heavily relies on the continuous supply of electricity. In this sense, long-term powering and recharging of an IMD via\\u000a a highly safe, efficient and convenient way

  19. Estimation of groundwater recharge parameters by time series analysis.

    USGS Publications Warehouse

    Naff, R.L.; Gutjahr, A.L.

    1983-01-01

    A model is proposed that relates water level fluctuations in a Dupuit aquifer to effective precipitation at the top of the unsaturated zone. Effective precipitation, defined herein as that portion of precipitation which becomes recharge, is related to precipitation measured in a nearby gage by a two-parameter function. A second-order stationary assumption is used to connect the spectra of effective precipitation and water level fluctuations.-from Authors

  20. Estimating recharge at Yucca Mountain, Nevada: A case study

    SciTech Connect

    Flint, A.; Flint, L.; Kwicklis, E.; Fabryka-Martin, J.; Bodvarsson, G.S.

    2001-05-13

    Obtaining values of net infiltration, groundwater travel time, and recharge is necessary at the Yucca Mountain site, Nevada, USA, in order to evaluate the expected performance of a potential repository as a containment system for high-level radioactive waste. However, the geologic complexities of this site, its low precipitation and net infiltration, with numerous mechanisms operating simultaneously to move water through the system, provide many challenges for the estimation of the spatial distribution of recharge. A variety of methods appropriate for arid environments has been applied, including water-balance techniques, calculations using Darcy's law in the unsaturated zone, a soil-physics method applied to neutron-hole water-content data, inverse modeling of thermal profiles in boreholes extending through the thick unsaturated zone, chloride mass balance, atmospheric radionuclides, and empirical approaches. These methods indicate that near-surface infiltration rates at Yucca Mountain are highly variable in time and space, with local (point) values ranging from zero to several hundred millimeters per year. Spatially distributed net-infiltration values average 5 mm/year, with the highest values approaching 20 mm/year near Yucca Crest. Site-scale recharge estimates range from less than 1 to about 12 mm/year. These results have been incorporated into a site-scale model that has been calibrated using these data sets that reflect infiltration processes acting on highly variable temporal and spatial scales. The modeling study predicts highly non-uniform recharge at the water table, distributed significantly differently from the non-uniform infiltration pattern at the surface.

  1. Estimating recharge at yucca mountain, nevada, usa: comparison of methods

    SciTech Connect

    Flint, A. L.; Flint, L. E.; Kwicklis, E. M.; Fabryka-Martin, J. T.; Bodvarsson, G. S.

    2001-11-01

    Obtaining values of net infiltration, groundwater travel time, and recharge is necessary at the Yucca Mountain site, Nevada, USA, in order to evaluate the expected performance of a potential repository as a containment system for high-level radioactive waste. However, the geologic complexities of this site, its low precipitation and net infiltration, with numerous mechanisms operating simultaneously to move water through the system, provide many challenges for the estimation of the spatial distribution of recharge. A variety of methods appropriate for and environments has been applied, including water-balance techniques, calculations using Darcy's law in the unsaturated zone, a soil-physics method applied to neutron-hole water-content data, inverse modeling of thermal profiles in boreholes extending through the thick unsaturated zone, chloride mass balance, atmospheric radionuclides, and empirical approaches. These methods indicate that near-surface infiltration rates at Yucca Mountain are highly variable in time and space, with local (point) values ranging from zero to several hundred millimeters per year. Spatially distributed net-infiltration values average 5 mm/year, with the highest values approaching 20 nun/year near Yucca Crest. Site-scale recharge estimates range from less than I to about 12 mm/year. These results have been incorporated into a site-scale model that has been calibrated using these data sets that reflect infiltration processes acting on highly variable temporal and spatial scales. The modeling study predicts highly non-uniform recharge at the water table, distributed significantly differently from the non-uniform infiltration pattern at the surface. [References: 57

  2. Estimating areas contributing recharge to wells, lessons from previous studies

    USGS Publications Warehouse

    Franke, O. Lehn; Reilly, T.E.; Pollock, D.W.; LaBaugh, J.W.

    1998-01-01

    Factors relating to the estimation of areas contributing recharge to wells, such as complexity of the ground-water flow system, effects of changing hydrologic conditions, and effects of well-screen locations and pumping rates, are reviewed. The point of view that simulation is the best means to obtain physically based estimates of contributing areas is emphasized. An extensive list of USGS reports that include estimation of contributing areas is provided.

  3. 12-Crown-4 Ether Improves Rechargeable Lithium Cells

    NASA Technical Reports Server (NTRS)

    Nagasubramanian, Ganesan; Attia, Alan I.

    1992-01-01

    Experiments show addition of 12-crown-4 ether (12Cr4) to thin film of polyethylene oxide (PEO) and LiBF4 reduces charge-transfer resistance of film and enhances performance of electrochemical cell in which film is electrolyte, anode is lithium, and cathode is LixCoO2. By increasing conductivity of the electrolyte, 12Cr4 reduces polarization loss; enabling cell to sustain higher current. Result is new type of rechargeable lithium cell.

  4. Electrochemically Stable Cathode Current Collectors for Rechargeable Magnesium Batteries

    SciTech Connect

    Cheng, Yingwen; Liu, Tianbiao L.; Shao, Yuyan; Engelhard, Mark H.; Liu, Jun; Li, Guosheng

    2014-01-01

    Rechargeable Mg batteries are attractive energy storage systems and could bring cost-effective energy solutions. Currently, however, no practical cathode current collectors that can withstand high voltages in Mg2+ electrolytes has been identified and therefore cathode research is greatly hindered. Here we identified that two metals, Mo and W, are electrochemically stable through formation of surface passive layers. The presented results could have significant impacts on the developments of high voltage Mg batteries.

  5. Evaluation of groundwater artificial recharge management scenario for sustainable water resources development in Gaza Strip

    NASA Astrophysics Data System (ADS)

    Rusteberg, Bernd; Azizur Rahman, M.; Abusaada, Muath; Rabi, Ayman; Rahman Tamimi, A.; Sauter, Martin

    2010-05-01

    The water resources in Gaza Strip are currently facing extreme over-exploitation which has led to a sharp decline of the groundwater level in this Mediterranean coastal aquifer overtime. Salinity of the groundwater is very high as a result of subsequent seawater intrusion of the aquifer. The contamination of the Gaza Strip groundwater by seawater has wide-ranging effects on the regional economy as well as agricultural productivity. In order to guarantee the sustainability of regional development, which requires the access to clean water, groundwater artificial recharge (AR) is being considered as a potential solution to this current water resources problem. The objective of the present study is to analyze several strategies for the implementation and management of AR in Gaza Strip and their potential impacts on agriculture, environment, and the socio-economy. Based on the water policy on wastewater reclamation and reuse (Yr. 2005 - 2025), six AR management strategies were developed in close cooperation with the local stakeholder community. These scenarios take into consideration the development of the new North Gaza Wastewater Treatment Plant and were also judged with respect to a base-line scenario, otherwise known as the "Do Nothing Approach." Multi-Criteria Decision Analysis (MCDA) on ranking of the AR management scenarios was used. Twenty-one criteria ranging over a wide spectrum and four categories (Environmental, Public Health, Social, and Economical) were defined to ensure sound evaluation of each of the six AR management scenarios. A detailed geo-database was prepared to analyze all the related spatial, non-spatial, and temporal data. Socio-economic studies, field surveys, mathematical modeling, and GIS analysis were used for the criteria quantification. In the MCDA, Analytical Hierarchy Method (AHP) combined with weighted Linear Combination (WLC) and Composite Programming (CP) was employed. The six AR management strategies were thus compared to the "Do Nothing Approach" based on the defined environmental, health, social, and economical criteria, the most important being related to the environment and the economy. The robustness of the achieved ranking of AR management options has been tested by changing the selected criteria, criteria importance and criteria structure. The final analysis shows that all six AR management strategies are better than "doing nothing". The implementation of groundwater artificial recharge with maximum possible infiltration of secondary treated effluent in conjunction with sustainable reuse of the recharged water for agricultural development is the most effective AR solution to the water resources problems of the Gaza Strip.

  6. Movement of water infiltrated from a recharge basin to wells

    USGS Publications Warehouse

    O'Leary, David R.; Izbicki, John A.; Moran, Jean E.; Meeth, Tanya; Nakagawa, Brandon; Metzger, Loren; Bonds, Chris; Singleton, Michael J.

    2012-01-01

    Local surface water and stormflow were infiltrated intermittently from a 40-ha basin between September 2003 and September 2007 to determine the feasibility of recharging alluvial aquifers pumped for public supply, near Stockton, California. Infiltration of water produced a pressure response that propagated through unconsolidated alluvial-fan deposits to 125 m below land surface (bls) in 5 d and through deeper, more consolidated alluvial deposits to 194 m bls in 25 d, resulting in increased water levels in nearby monitoring wells. The top of the saturated zone near the basin fluctuates seasonally from depths of about 15 to 20 m. Since the start of recharge, water infiltrated from the basin has reached depths as great as 165 m bls. On the basis of sulfur hexafluoride tracer test data, basin water moved downward through the saturated alluvial deposits until reaching more permeable zones about 110 m bls. Once reaching these permeable zones, water moved rapidly to nearby pumping wells at rates as high as 13 m/d. Flow to wells through highly permeable material was confirmed on the basis of flowmeter logging, and simulated numerically using a two-dimensional radial groundwater flow model. Arsenic concentrations increased slightly as a result of recharge from 2 to 6 ?g/L immediately below the basin. Although few water-quality issues were identified during sample collection, high groundwater velocities and short travel times to nearby wells may have implications for groundwater management at this and at other sites in heterogeneous alluvial aquifers.

  7. A new analytical method for groundwater recharge and discharge estimation

    NASA Astrophysics Data System (ADS)

    Liang, Xiuyu; Zhang, You-Kuan

    2012-07-01

    SummaryA new analytical method was proposed for groundwater recharge and discharge estimation in an unconfined aquifer. The method is based on an analytical solution to the Boussinesq equation linearized in terms of h2, where h is the water table elevation, with a time-dependent source term. The solution derived was validated with numerical simulation and was shown to be a better approximation than an existing solution to the Boussinesq equation linearized in terms of h. By calibrating against the observed water levels in a monitoring well during a period of 100 days, we shown that the method proposed in this study can be used to estimate daily recharge (R) and evapotranspiration (ET) as well as the lateral drainage. It was shown that the total R was reasonably estimated with a water-table fluctuation (WTF) method if the water table measurements away from a fixed-head boundary were used, but the total ET was overestimated and the total net recharge was underestimated because of the lack of consideration of lateral drainage and aquifer storage in the WTF method.

  8. Aquifer recharge with reclaimed water in the Llobregat Delta. Laboratory batch experiments and field test site.

    NASA Astrophysics Data System (ADS)

    Tobella, J.

    2010-05-01

    Summary Spain, as most other Mediterranean countries, faces near future water shortages, generalized pollution and loss of water dependent ecosystems. Aquifer recharge represents a promising option to become a source for indirect potable reuse purposes but presence of pathogens as well as organic and inorganic pollutants should be avoided. To this end, understanding the processes of biogeochemical degradation occurring within the aquifer during infiltration is capital. A set of laboratory batch experiments has been assembled in order to assess the behaviour of selected pesticides, drugs, estrogens, surfactant degradation products, biocides and phthalates under different redox conditions. Data collected during laboratory experiments and monitoring activities at the Sant Vicenç dels Horts test site will be used to build and calibrate a numerical model (i) of the physical-chemical-biochemical processes occurring in the batches and (ii) of multicomponent reactive transport in the unsaturated/saturated zone at the test site. Keywords Aquifer recharge, batch experiments, emerging micropollutants, infiltration, numerical model, reclaimed water, redox conditions, Soil Aquifer Treatment (SAT). 1. Introduction In Spain, the Llobregat River and aquifers, which supply water to Barcelona, have been overexploited for years and therefore, suffer from serious damages: the river dries up on summer, riparian vegetation has disappeared and seawater has intruded the aquifer. In a global context, solutions to water stress problems are urgently needed yet must be sustainable, economical and safe. Recent developments of analytical techniques detect the presence of the so-called "emerging" organic micropollutants in water and soils. Such compounds may affect living organisms when occurring in the environment at very low concentrations (microg/l or ng/l). In wastewater and drinking water treatment plants, a remarkable removal of these chemicals from water can be obtained only using advanced and costly treatments. Nevertheless, a number of studies are demonstrating that physical, chemical and biochemical processes associated with water movement within the subsoil represent a natural alternative way to reduce the presence of these contaminants. This processes are called Soil Aquifer Treatment (SAT). Aquifer recharge will become a source for indirect potable reuse purposes as long as the presence of pathogens and organic and inorganic pollutants is avoided. To this end, understanding the biogeochemical degradation processes occurring within the aquifer during infiltration is capital. 2. Laboratory batch experiments A set of laboratory batch experiments has been assembled to assess the behaviour of selected pesticides, drugs, estrogens, surfactant degradation products, biocides and phthalates under different redox conditions. The setup of the experiments consists of glass bottles containing 120 g of soil and 240 ml of synthetic water spiked with the mix of micropollutants. A source of easily degradable organic carbon and, depending on the type of test, electron acceptors are added in order to yield aerobic respiration and nitrate/iron/manganese/sulphate reduction conditions. The evolution of the processes is monitored by sacrificing duplicate bottles according to a defined schedule and analysing water for major and minor components as well as for micropollutants. Results from biotic tests are compared with abiotic ones in order to discern biodegradation from other chemical processes. The soil, the synthetic water and the micropollutants selected for the experiments are representative of a test site in the nearby of Barcelona (Spain) where artificial recharge of groundwater through ponds is going to be performed using river water or tertiary effluent from a waste water treatment plant. The results of the experiments improve the knowledge on the behaviour of the selected micropollutants under different redox conditions and provide with useful information on the conditions to develop at the test site during artificial recharge. The data coll

  9. High power rechargeable thermal battery. Final report, 1 September 1996-31 July 1997

    SciTech Connect

    Kaun, T.D.

    1997-08-15

    Report developed under STTR contract; a proof of concept for a portable, rechargeable thermal battery (RTB). Including a superinsulated case, a lightweight (10 lb) RTB can provide 250W for 2-6h at 140 Wh/kg with days of activation between recharging. It can also provide 1 kW pulses (30s) throughout its capacity. The RTB at 10 lbs 250W fills a gap in power supply capability for ARMY field operations under which motor generators cannot be down-sized (about 40 lbs). Three accomplishments have lead to the portable RTB. (1) Increased specific energy by way of high rate, thick electrode LiAl/FeS2 with CuFeS2 cells. (No Ni or Co content) (2) A vacuum-insulated case enables versitility (3W heat loss for days of operation, no heat signature) (3) High durability under abusive field conditions (safety discharge to 0 volts, no overheating at full power). Durability and safety are key features of the Phase I demonstration. A 4-cell battery RTB was operated for 140 cycles under full capacity, constant power discharges. More than twenty thermal cycles, some deactivations during charging or discharging, showed no ill effects. (It uses MgO powder separator). Overcharging and overdischarging posed no safety problems. The RTB has inherent battery charge/discharge balancing which remains a problem for Li-ion, Li/polymer batteries. Also RTB has no organic or Ni/Co compounds which avoids toxicity and explosion hazards. Improved RTB design gives prospect for low cost commercial battery applications. The elevated operating temperature of RTB provides a unique symbiotic-type technology with cheap getters (gas absorbers) forming/sustaining the vacuum insulated housing and dramatically-extending the operating life for 2-3 days after activation. It is immune to hot/cold ambient temperatures, and can be operated continuously with periodic charging. A 25 year shelf life can be anticipated.

  10. Estimating harvested rainwater at greenhouses in south Portugal aquifer Campina de Faro for potential infiltration in Managed Aquifer Recharge.

    NASA Astrophysics Data System (ADS)

    Costa, Luís; Monteiro, José Paulo; Leitão, Teresa; Lobo-Ferreira, João Paulo; Oliveira, Manuel; Martins de Carvalho, José; Martins de Carvalho, Tiago; Agostinho, Rui

    2015-04-01

    The Campina de Faro (CF) aquifer system, located on the south coast of Portugal, is an important source of groundwater, mostly used for agriculture purposes. In some areas, this multi-layered aquifer is contaminated with high concentration of nitrates, possibly arising from excessive usage of fertilizers, reaching to values as high as 300 mg/L. In order to tackle this problem, Managed Aquifer Recharge (MAR) techniques are being applied at demonstration scale to improve groundwater quality through aquifer recharge, in both infiltration basins at the river bed of ephemeral river Rio Seco and existing traditional large diameter wells located in this aquifer. In order to assess the infiltration capacity of the existing infrastructures, in particular infiltration basins and large diameter wells at CF aquifer, infiltration tests were performed, indicating a high infiltration capacity of the existing infrastructures. Concerning the sources of water for recharge, harvested rainwater at greenhouses was identified in CF aquifer area as one of the main potential sources for aquifer recharge, once there is a large surface area occupied by these infrastructures at the demo site. This potential source of water could, in some cases, be redirected to the large diameter wells or to the infiltration basins at the riverbed of Rio Seco. Estimates of rainwater harvested at greenhouses were calculated based on a 32 year average rainfall model and on the location of the greenhouses and their surface areas, the latter based on aerial photograph. Potential estimated annual rainwater intercepted by greenhouses at CF aquifer accounts an average of 1.63 hm3/year. Nonetheless it is unlikely that the totality of this amount can be harvested, collected and redirected to aquifer recharge infrastructures, for several reasons, such as the lack of appropriate greenhouse infrastructures, conduits or a close location between greenhouses and large diameter wells and infiltration basins. Anyway, this value is a good indication of the total amount of the harvested rainfall that could be considered for future MAR solutions. Given the estimates on the greenhouse harvested rainwater and the infiltration capacity of the infiltration basins and large diameter wells, it is intended to develop groundwater flow models in order to assess the nitrate washing rate in the CF aquifer. This work is being developed under the scope of MARSOL Project (MARSOL-GA-2013-619120), in which Campina de Faro aquifer system is one of the several case studies. This project aims to demonstrate that MAR is a sound, safe and sustainable strategy that can be applied with great confidence in finding solutions to water scarcity in Southern Europe.

  11. Soil Water Balance and Recharge Monitoring at the Hanford Site - FY09 Status Report

    SciTech Connect

    Rockhold, Mark L.; Saunders, Danielle L.; Strickland, Christopher E.; Waichler, Scott R.; Clayton, Ray E.

    2009-09-28

    Recharge provides the primary driving force for transporting contaminants from the vadose zone to underlying aquifer systems. Quantification of recharge rates is important for assessing contaminant transport and fate and for evaluating remediation alternatives. This report describes the status of soil water balance and recharge monitoring performed by Pacific Northwest National Laboratory at the Hanford Site for Fiscal Year 2009. Previously reported data for Fiscal Years 2004 - 2008 are updated with data collected in Fiscal Year 2009 and summarized.

  12. Climatic controls on diffuse groundwater recharge in semiarid environments of the southwestern United States

    Microsoft Academic Search

    Eric E. Small

    2005-01-01

    Although there is no diffuse groundwater recharge at many semiarid sites, evidence for diffuse recharge exists at some locations where mean annual precipitation $\\\\overline{P}$ is much less than mean annual potential evapotranspiration $\\\\overline{PET}$, particularly where soils are coarse and rainfall variable is substantial. We investigate the climatic controls on diffuse recharge using a one-dimensional, variably saturated flow model. The model

  13. Climatic controls on diffuse groundwater recharge in semiarid environments of the southwestern United States

    Microsoft Academic Search

    Eric E. Small

    2005-01-01

    Although there is no diffuse groundwater recharge at many semiarid sites, evidence for diffuse recharge exists at some locations where mean annual precipitation $\\\\overline{P is much less than mean annual potential evapotranspiration $\\\\overline{PET, particularly where soils are coarse and rainfall variable is substantial. We investigate the climatic controls on diffuse recharge using a one-dimensional, variably saturated flow model. The model

  14. Impacts of climate change on groundwater in Australia: a sensitivity analysis of recharge

    Microsoft Academic Search

    J. L. McCallum; R. S. Crosbie; G. R. Walker; W. R. Dawes

    2010-01-01

    Groundwater recharge is a complex process reflecting many interactions between climate, vegetation and soils. Climate change\\u000a will impact upon groundwater recharge but it is not clear which climate variables have the greatest influence over recharge.\\u000a This study used a sensitivity analysis of climate variables using a modified version of WAVES, a soil-vegetation-atmosphere-transfer\\u000a model (unsaturated zone), to determine the importance of

  15. Water table fluctuation owing to time-varying recharge, pumping and leakage

    Microsoft Academic Search

    S. N. Rai; A. Manglik; V. S. Singh

    2006-01-01

    This paper presents an analytical solution of a 2-d linearized Boussinesq equation to predict water table variation in a horizontal aquifer induced by time-varying recharge and\\/or withdrawal from any number of recharge basins, pumping wells and leakage sites of different dimensions. The rate of time-varying recharge (or withdrawal) is approximated by series of line elements of different lengths and slopes

  16. Estimation of groundwater recharge from water storage structures in a semi-arid climate of India

    Microsoft Academic Search

    V. N. Sharda; R. S. Kurothe; D. R. Sena; V. C. Pande; S. P. Tiwari

    2006-01-01

    Groundwater recharge from water storage structures under semi-arid conditions of western India has been estimated by employing water table fluctuation (WTF) and chloride mass balance (CMB) methods. Groundwater recharge was estimated as 7.3% and 9.7% of the annual rainfall by WTF method for the years 2003 and 2004, respectively while the two years average recharge was estimated as 7.5% using

  17. Shallow groundwater recharge mechanism and apparent age in the Ndop plain, northwest Cameroon

    NASA Astrophysics Data System (ADS)

    Wirmvem, Mengnjo Jude; Mimba, Mumbfu Ernestine; Kamtchueng, Brice Tchakam; Wotany, Engome Regina; Bafon, Tasin Godlove; Asaah, Asobo Nkengmatia Elvis; Fantong, Wilson Yetoh; Ayonghe, Samuel Ndonwi; Ohba, Takeshi

    2015-02-01

    Knowledge of groundwater recharge and apparent age constitutes a valuable tool for its sustainable management. Accordingly, shallow groundwater (n = 72) in the Ndop plain has been investigated using the stable isotopes of oxygen (18O) and hydrogen (2H or D) and tritium (3H) to determine the recharge process, timing and rate of recharge, and residence time. The shallow groundwater showed low variability in ?18O values (-2.7 to -4.1 ‰) and 3H content (2.4-3.1 TU). The low variability suggests a similar origin, homogenous aquifer, good water mixing and storage capacity of the groundwater reservoir. Like surface water, a cluster of groundwater along the Ndop Meteoric Water Line (NMWL) and Global Meteoric Water Line indicates meteoric origin/recharge. The rainfall recharge occurs under low relative humidity conditions and negligible evaporation effect. About 80 % of the recharge is from direct heterogeneous/diffuse local precipitation at low altitude (<1,260 m) within the Ndop plain. Approximately 20 % is from high altitude precipitation (localised recharge) or is recharged by the numerous inflowing streams and rivers from high elevations. A homogenous cluster of ?-values in groundwater (and surface water) between May and June monsoon rains on the NMWL suggests dominant recharge during these months. The recharge represents at least 16 % (>251 mm) of the annual rainfall (1,540 mm) indicating high annual recharge; high enough for development of the groundwater resource for agriculture. The 3H content (>2.4 TU) in groundwater indicates post-1952 recharged water with an estimated residence time <30 years, suggesting short subsurface circulation, and subsequently a renewable aquifer.

  18. NEACRP standard problem exercise on criticality codes for dissolving fissile oxides in acids: A reference method for treating the fuel double heterogeneity

    SciTech Connect

    Santamarina, A.; Smith, H.J. (CEA Centre d'Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France). Div. d'Etudes et de Developpement des Reacteurs); Whitesides, G.E. (Oak Ridge National Lab., TN (USA))

    1990-01-01

    The value of international comparison studies by the OECD-NEA Criticality Working Group has again been demonstrated by this study. Computational methods that had been commonly used for criticality safety calculations and which were shown to be valid for systems for which experimental data existed, were demonstrated to be inadequate when extrapolated to some simulated actual situations. The major source of dispersion in the results in international criticality benchmark calculations on problems treating a fuel double heterogeneity is shown to be the incorrect evaluation of effective resonance cross sections for 238U. A reference calculational method is proposed and used to evaluate theoretically the errors created by various standard methods of calculating the effects of self-shielding of resonance cross sections. 7 figs., 3 tabs.

  19. POD-based Monte Carlo approach for the solution of regional scale groundwater flow driven by randomly distributed recharge

    NASA Astrophysics Data System (ADS)

    Pasetto, Damiano; Guadagnini, Alberto; Putti, Mario

    2011-11-01

    We present a methodology conducive to the application of a Galerkin model order reduction technique, Proper Orthogonal Decomposition (POD), to solve a groundwater flow problem driven by spatially distributed stochastic forcing terms. Typical applications of POD to reducing time-dependent deterministic partial differential equations (PDEs) involve solving the governing PDE at some observation times (termed snapshots), which are then used in the order reduction of the problem. Here, the application of POD to solve the stochastic flow problem relies on selecting the snapshots in the probability space of the random quantity of interest. This allows casting a standard Monte Carlo (MC) solution of the groundwater flow field into a Reduced Order Monte Carlo (ROMC) framework. We explore the robustness of the ROMC methodology by way of a set of numerical examples involving two-dimensional steady-state groundwater flow taking place within an aquifer of uniform hydraulic properties and subject to a randomly distributed recharge. We analyze the impact of (i) the number of snapshots selected from the hydraulic heads probability space, (ii) the associated number of principal components, and (iii) the key geostatistical parameters describing the heterogeneity of the distributed recharge on the performance of the method. We find that our ROMC scheme can improve significantly the computational efficiency of a standard MC framework while keeping the same degree of accuracy in providing the leading statistical moments (i.e. mean and covariance) as well as the sample probability density of the state variable of interest.

  20. Estimated ground-water recharge from streamflow in Fortymile Wash near Yucca Mountain, Nevada

    SciTech Connect

    Savard, C.S.

    1998-10-01

    The two purposes of this report are to qualitatively document ground-water recharge from stream-flow in Fortymile Wash during the period 1969--95 from previously unpublished ground-water levels in boreholes in Fortymile Canyon during 1982--91 and 1995, and to quantitatively estimate the long-term ground-water recharge rate from streamflow in Fortymile Wash for four reaches of Fortymile Wash (Fortymile Canyon, upper Jackass Flats, lower Jackass Flats, and Amargosa Desert). The long-term groundwater recharge rate was estimated from estimates of the volume of water available for infiltration, the volume of infiltration losses from streamflow, the ground-water recharge volume from infiltration losses, and an analysis of the different periods of data availability. The volume of water available for infiltration and ground-water recharge in the four reaches was estimated from known streamflow in ephemeral Fortymile Wash, which was measured at several gaging station locations. The volume of infiltration losses from streamflow for the four reaches was estimated from a streamflow volume loss factor applied to the estimated streamflows. the ground-water recharge volume was estimated from a linear relation between infiltration loss volume and ground-water recharge volume for each of the four reaches. Ground-water recharge rates were estimated for three different periods of data availability (1969--95, 1983--95, and 1992--95) and a long-term ground-water recharge rate estimated for each of the four reaches.

  1. Use of Soil Moisture Probes to Estimate Ground Water Recharge At an Oil Spill Site

    NASA Astrophysics Data System (ADS)

    Delin, Geoffrey N.; Herkelrath, William N.

    2005-12-01

    Soil moisture data collected using an automated data logging system were used to estimate ground water recharge at a crude oil spill research site near Bemidji, Minnesota. Three different soil moisture probes were tested in the laboratory as well as the field conditions of limited power supply and extreme weather typical of northern Minnesota: a self-contained reflectometer probe, and two time domain reflectometry (TDR) probes, 30 and 50 cm long. Recharge was estimated using an unsaturated zone water balance method. Recharge estimates for 1999 using the laboratory calibrations were 13 to 30 percent greater than estimates based on the factory calibrations. Recharge indicated by the self-contained probes was 170 percent to 210 percent greater than the estimates for the TDR probes regardless of calibration method. Results indicate that the anomalously large recharge estimates for the self-contained probes are not the result of inaccurate measurements of volumetric moisture content, but result from the presence of crude oil, or borehole leakage. Of the probes tested, the 50 cm long TDR probe yielded recharge estimates that compared most favorably to estimates based on a method utilizing water table fluctuations. Recharge rates for this probe represented 24 to 27 percent of 1999 precipitation. Recharge based on the 30 cm long horizontal TDR probes was 29 to 37 percent of 1999 precipitation. By comparison, recharge based on the water table fluctuation method represented about 29 percent of precipitation.

  2. Use of soil moisture probes to estimate ground water recharge at an oil spill site

    USGS Publications Warehouse

    Delin, G.N.; Herkelrath, W.N.

    2005-01-01

    Soil moisture data collected using an automated data logging system were used to estimate ground water recharge at a crude oil spill research site near Bemidji, Minnesota. Three different soil moisture probes were tested in the laboratory as well as the field conditions of limited power supply and extreme weather typical of northern Minnesota: a self-contained reflectometer probe, and two time domain reflectometry (TDR) probes, 30 and 50 cm long. Recharge was estimated using an unsaturated zone water balance method. Recharge estimates for 1999 using the laboratory calibrations were 13 to 30 percent greater than estimates based on the factory calibrations. Recharge indicated by the self-contained probes was 170 percent to 210 percent greater than the estimates for the TDR probes regardless of calibration method. Results indicate that the anomalously large recharge estimates for the self-contained probes are not the result of inaccurate measurements of volumetric moisture content, but result from the presence of crude oil, or bore-hole leakage. Of the probes tested, the 50 cm long TDR probe yielded recharge estimates that compared most favorably to estimates based on a method utilizing water table fluctuations. Recharge rates for this probe represented 24 to 27 percent of 1999 precipitation. Recharge based on the 30 cm long horizontal TDR probes was 29 to 37 percent of 1999 precipitation. By comparison, recharge based on the water table fluctuation method represented about 29 percent of precipitation. (JAWRA) (Copyright ?? 2005).

  3. Estimation of groundwater recharge from water storage structures in a semi-arid climate of India

    NASA Astrophysics Data System (ADS)

    Sharda, V. N.; Kurothe, R. S.; Sena, D. R.; Pande, V. C.; Tiwari, S. P.

    2006-09-01

    SummaryGroundwater recharge from water storage structures under semi-arid conditions of western India has been estimated by employing water table fluctuation (WTF) and chloride mass balance (CMB) methods. Groundwater recharge was estimated as 7.3% and 9.7% of the annual rainfall by WTF method for the years 2003 and 2004, respectively while the two years average recharge was estimated as 7.5% using CMB method. A Recharge function depicting the relationship between potential recharge from storage structures and successive day averaged storage depths was better exhibited by a power function. A diagnostic relationship correlating the rainfall to the potential recharge from water storage structures has been developed to explain the characteristics of the storage structures for a given geographical location. The study has revealed that a minimum of 104.3 mm cumulative rainfall is required to generate 1 mm of recharge from the water storage structures. It was also inferred that the storage structures have limited capacity to induce maximum recharge irrespective of the amount of rainfall and maximum recharge to rainfall ratio is achieved at a lower rainfall than the average annual rainfall of the area. An empirical linear relationship was found to reasonably correlate the changes in chloride concentration with water table rise or fall in the study area.

  4. A numerical analysis on the applicability of the water level fluctuation method for quantifying groundwater recharge

    NASA Astrophysics Data System (ADS)

    Koo, M.; Lee, D.

    2002-12-01

    The water table fluctuation(WTF) method is a conventional method for quantifying groundwater recharge by multiplying the specific yield to the water level rise. Based on the van Genuchten model, an analytical relationship between groundwater recharge and the water level rise is derived. The equation is used to analyze the effects of the depth to water level and the soil properties on the recharge estimate using the WTF method. The results show that the WTF method is reliable when applied to the aquifers of the fluvial sand provided the water table is below 1m depth. However, if it is applied to the silt loam having the water table depth ranging 4~10m, the recharge is overestimated by 30~80%, and the error increases drastically as the water table is getting shallower. A 2-D unconfined flow model with a time series of the recharge rate is developed. It is used for elucidating the errors of the WTF method, which is implicitly based on the tank model where the horizontal flow in the saturated zone is ignored. Simulations show that the recharge estimated by the WTF method is underestimated for the observation well near the discharge boundary. This is due to the fact that the hydraulic stress resulting from the recharge is rapidly dissipating by the horizontal flow near the discharge boundary. Simulations also reveal that the recharge is significantly underestimated with increase in the hydraulic conductivity and the recharge duration, and decrease in the specific yield.

  5. Using Tracer Tests to Estimate Vertical Recharge and Evaluate Influencing Factors for Irrigated Agricultural Systems

    NASA Astrophysics Data System (ADS)

    Lin, D.; Jin, M.; Brusseau, M.; Ma, B.; Liu, Y.

    2013-12-01

    Accurate estimation of vertical groundwater recharge is critical for (semi) arid regions, especially in places such as the North China Plain where vertical recharge comprises the largest portion of recharge. Tracer tests were used to estimate vertical recharge beneath agricultural systems irrigated by groundwater, and to help delineate factors that influence recharge. Bromide solution was applied to trace infiltration in the vadose zone beneath irrigated agricultural fields (rotated winter wheat and summer maize, orchards, and cotton) and non-irrigated woodlands at both piedmont plain (Shijiazhaung) and alluvial and lacustrine plains (Hengshui) in the North China Plain. The tracer tests lasted for more than two years, and were conducted at a total of 37 sites. Tracer solution was injected into the subsurface at a depth of 1.2 m before the rainy season. Soil samples were then collected periodically to observe bromide transport and estimate recharge rates at the point-scale. For these experiments, the only irrigation the fields received was that applied by the landowners. In addition to these tests, a controlled irrigation experiment was conducted at a single wheat and maize site. The results showed that recharge rates were lower for the alluvial and lacustrine plains sites, which comprise finer-textured soils than those present in the piedmont plain. Specifically, the recharge rate ranged between 56-466 mm/a beneath wheat-maize, 110-564 mm/a beneath orchard, and 0-21 mm/a beneath woodlands with an average recharge coefficient of 0.17 for the piedmont plain sites, while the recharge rate ranged between 26-165 mm/a beneath wheat-maize, 6-40 mm/a beneath orchard, 87-319 mm/a beneath cotton, and 0-32 mm/a beneath woodlands with an average recharge coefficient of 0.10 for the alluvial and lacustrine plain sites. Irrigation provided the primary contribution to recharge, with precipitation providing a minor contribution. The results of both the uncontrolled and controlled irrigation experiments showed that recharge increased as irrigation quantity increased. Overall, recharge was lower for the fields with the rotation cultivation of winter wheat and summer maize compared to the aged apple orchard. In general, the irrigation quantity applied was larger than the requirement of the crops. Thus, managing the irrigation regime to insure that irrigation matches crop requirements would be helpful to better preserve groundwater resources and prevent water-table decline. The recharge rates obtained in this study will be used as input in a mathematical modeling effort designed to simulate the regional groundwater system in the North China Plain.

  6. Numerical assessment of ASR recharge using small-diameter wells and surface basins

    NASA Astrophysics Data System (ADS)

    Händel, Falk; Liu, Gaisheng; Dietrich, Peter; Liedl, Rudolf; Butler, James J.

    2014-09-01

    Aquifer storage and recovery (ASR) methods are increasingly used to overcome the temporal imbalance between water demand and availability. Common ASR recharge methods utilize large-diameter injection wells or surface infiltration basins and trenches, and can be costly to implement. A new low-cost ASR recharge method is currently being developed. This approach is based on recharge via gravity in small-diameter wells installed with direct-push (DP) technology. Numerical modeling is used here to assess the potential of this new approach under conditions commonly faced in field settings. The primary objective is to investigate if a battery of small-diameter DP wells can serve as a viable alternative to a surface basin under typical field conditions, while the secondary objective is to assess which subsurface parameters have the greatest control on DP well performance. Simulation results indicate that gravity recharge via small-diameter wells appears to have a distinct advantage over recharge via surface infiltration basins. For example, two 0.05-m shallow vadose-zone wells with 9-m screens can recharge water at a greater rate than a 60 m2 basin. Also, results reveal that, contrary to an infiltration basin, the recharge rate in a DP well has a much stronger dependence on the horizontal component of hydraulic conductivity than on the vertical component. Moreover, near-surface layers of low hydraulic conductivity, which can significantly reduce the recharge capacity of a surface basin, have a relatively small impact on the recharge capacity of a well as long as a significant portion of the well screen is installed below those layers. Given that installation and operation costs can be low in comparison to common ASR recharge methods, this new approach appears to have great potential for recharging good quality water in shallow unconsolidated aquifers. A field investigation has recently been initiated to follow up the findings of this simulation assessment.

  7. Predicting Groundwater Recharge for the Okanagan Basin: A Little HELP From the Locals

    NASA Astrophysics Data System (ADS)

    Liggett, J. E.; Toews, M. W.; Smerdon, B. D.; Allen, D. M.

    2007-12-01

    Estimates of groundwater recharge are an essential component in flow models; however, recharge is highly uncertain and difficult to quantify for dry regions. Since flow models are often used in water management planning, acquiring spatially variable recharge estimates at a comparable scale can be challenging. Regional scale recharge estimates must reflect trends of local scale processes to be effective in planning. This study examined how results from a regional recharge model compared to recharge estimated in separate, local scale models from opposing ends of the Okanagan basin, in British Columbia, Canada. At nearly 8000~km2, the north-south trending basin has a climatic gradient with a warmer, wetter climate in the north and hotter, drier conditions in the south. The region has become a popular area for tourism, residence, and agriculture, particularly orchards and vineyards. With surface water sources close to fully allocated, the region is turning to groundwater as a means to support increasing socioeconomic growth. Basin wide (regional) recharge estimates in the valley bottom are a critical step in managing groundwater resources. Regional estimates of recharge were determined with the Hydrologic Evaluation of Landfill Performance (HELP) code by establishing common areas of soil texture, water table depth and three other hydrologic parameters. Results from the regional scale were compared with two independently derived, local scale estimates of groundwater recharge. For the south Okanagan, regional estimates were compared with results from a high-resolution integrated HELP and MODFLOW analysis; and in the north Okanagan, regional estimates were compared to results from a study utilizing the Richards equation based MIKE-SHE code. Comparison with these two models, calculated in areas at each end of the climatic gradient, provide confidence in developing a map of regional groundwater recharge. Preliminary results illustrate the applicability of HELP for predicting basin-wide recharge for areas with shallow slope (limited runoff), accurate depth to water table (from a water well database), and detailed descriptions of vadose zone lithology.

  8. Assessment of groundwater recharge in an ash-fall mantled karst aquifer of southern Italy

    NASA Astrophysics Data System (ADS)

    Manna, F.; Nimmo, J. R.; De Vita, P.; Allocca, V.

    2014-12-01

    In southern Italy, Mesozoic carbonate formations, covered by ash-fall pyroclastic soils, are large karst aquifers and major groundwater resources. For these aquifers, even though Allocca et al., 2014 estimated a mean annual groundwater recharge coefficient at regional scale, a more complete understanding of the recharge processes at small spatio-temporal scale is a primary scientific target. In this paper, we study groundwater recharge processes in the Acqua della Madonna test site (Allocca et al., 2008) through the integrated analysis of piezometric levels, rainfall, soil moisture and air temperature data. These were gathered with hourly frequency by a monitoring station in 2008. We applied the Episodic Master Recharge method (Nimmo et al., 2014) to identify episodes of recharge and estimate the Recharge to Precipitation Ratio (RPR) at both the individual-episode and annual time scales. For different episodes of recharge observed, RPR ranges from 97% to 37%, with an annual mean around 73%. This result has been confirmed by a soil water balance and the application of the Thornthwaite-Mather method to estimate actual evapotranspiration. Even though it seems higher than RPRs typical of some parts of the world, it is very close to the mean annual groundwater recharge coefficient estimated at the regional scale for the karst aquifers of southern Italy. In addition, the RPR is affected at the daily scale by both antecedent soil moisture and rainfall intensity, as demonstrated by a statistically significant multiple linear regression among such hydrological variables. In particular, the recharge magnitude is great for low storm intensity and high antecedent soil moisture value. The results advance the comprehension of groundwater recharge processes in karst aquifers, and the sensitivity of RPR to antecedent soil moisture and rainfall intensity facilitates the prediction of the influence of climate and precipitation regime change on the groundwater recharge process.

  9. Quantifying Groundwater Recharge Uncertainty: A Multiple-Model Framework and Case Study

    NASA Astrophysics Data System (ADS)

    Kikuchi, C.; Ferré, T. P. A.

    2014-12-01

    In practice, it is difficult to estimate groundwater recharge accurately. Despite this challenge, most recharge investigations produce a single, best estimate of recharge. However, there is growing recognition that quantification of natural recharge uncertainty is critical for groundwater management. We present a multiple-model framework for estimating recharge uncertainty. In addition, we show how direct water flux measurements can be used to reduce the uncertainty of estimates of total basin recharge for an arid, closed hydrologic basin in the Atacama Desert, Chile. We first formulated multiple hydrogeologic conceptual models of the basin based on existing data, and implemented each conceptual model for the purpose of conducting numerical simulations. For each conceptual model, groundwater recharge was inversely estimated; then, Null-Space Monte Carlo techniques were used to quantify the uncertainty on the initial estimate of total basin recharge. Second, natural recharge components - including both deep percolation and streambed infiltration - were estimated from field data. Specifically, vertical temperature profiles were measured in monitoring wells and streambeds, and water fluxes were estimated from thermograph analysis. Third, calculated water fluxes were incorporated as prior information to the model calibration and Null-Space Monte Carlo procedures, yielding revised estimates of both total basin recharge and associated uncertainty. The fourth and final component of this study uses value of information analyses to identify potentially informative locations for additional water flux measurements. The uncertainty quantification framework presented here is broadly transferable; furthermore, this research provides an applied example of the extent to which water flux measurements may serve to reduce groundwater recharge uncertainty at the basin scale.

  10. Rechargeable battery which combats shape change of the zinc anode

    NASA Technical Reports Server (NTRS)

    Cohn, E. M. (inventor)

    1976-01-01

    A rechargeable cell or battery is provided in which shape change of the zinc anode is combatted by profiling the ionic conductivity of the paths between the electrodes. The ion flow is greatest at the edges of the electrodes and least at the centers, thereby reducing migration of the zinc ions from edges to the center of the anode. A number of embodiments are disclosed in which the strength and/or amount of electrolyte, and/or the number and/or size of the paths provided by the separator between the electrodes, are varied to provide the desired ionic conductivity profile.

  11. Downstream of downtown: urban wastewater as groundwater recharge

    NASA Astrophysics Data System (ADS)

    Foster, S. S. D.; Chilton, P. J.

    Wastewater infiltration is often a major component of overall recharge to aquifers around urban areas, especially in more arid climates. Despite this, such recharge still represents only an incidental (or even accidental) byproduct of various current practices of sewage effluent handling and wastewater reuse. This topic is reviewed through reference to certain areas of detailed field research, with pragmatic approaches being identified to reduce the groundwater pollution hazard of these practices whilst attempting to retain their groundwater resource benefit. Since urban sewage effluent is probably the only `natural resource' whose global availability is steadily increasing, the socioeconomic importance of this topic for rapidly developing urban centres in the more arid parts of Asia, Africa, Latin America and the Middle East will be apparent. L'infiltration des eaux usées est souvent la composante essentielle de toute la recharge des aquifères des zones urbaines, particulièrement sous les climats les plus arides. Malgré cela, une telle recharge ne constitue encore qu'un sous-produit incident, ou même accidentel, de pratiques courantes variées du traitement de rejets d'égouts et de réutilisation d'eaux usées. Ce sujet est passé en revue en se référant à certaines régions étudiées en détail, par des approches pragmatiques reconnues pour permettre de réduire les risques de pollution des nappes dues à ces pratiques tout en permettant d'en tirer profit pour leur ressource en eau souterraine. Puisque les effluents d'égouts urbains sont probablement la seule « ressource naturelle » dont la disponibilité globale va croissant constamment, l'importance socio-économique de ce sujet est évidente pour les centres urbains à développement rapide de l'Asie, de l'Afrique, de l'Amérique latine et du Moyen-Orient. La infiltración de aguas residuales es a menudo un componente principal de la recarga total en acuíferos ubicados en torno a zonas urbanas, especialmente en los climas más áridos. A pesar de ello, dicho componente todavía es una consecuencia secundaria (o incluso accidental) de diversas prácticas asociadas con la manipulación de las aguas residuales y con la reutilitzación de aguas depuradas. Este tema se revisa mediante referencias a ciertas áreas en las que existen investigación detallada de campo, identificando enfoques pragmáticos con el fin de reducir el riesgo de contaminación de las aguas subterráneas por tales prácticas, a la vez tratando de conservar los beneficios para los recursos del acuífero. Dado que los efluentes de aguas residuales urbanas son probablemente la única `fuente natural' cuya disponibilidad global se halla en del aumento, la importancia socioeconómica de este tema será evidente para los centros urbanos de rápido desarrollo en Asia, Latinoamérica y Oriente Medio.

  12. Tracers in recharge — Effects of partitioning in soils

    NASA Astrophysics Data System (ADS)

    Gerritse, Robert G.; Adeney, John A.

    1992-02-01

    Partitioning among mobile and stationary water phases in a soil measurably reduces movement of a tracer relative to the mobile water phase. The quantity of water infiltrating the soil, however, still follows from the product of the distance travelled by the tracer and average moisture content of the soil over that distance. Partitioning between surface and water phases in a soil by proton and protium exchange has only a small effect on the retention of isotopically labelled water. Partitioning between surface, water and gas phases in a soil, however, strongly decreases diffusive movement of isotopically labelled water in the gas phase. In sandy soils with moisture contents less than 5%, the effective diffusion coefficient in the gas phase can be reduced by a factor between 50 and 5000. As a soil dries out, diffusive movement of 18O labelled water will become larger than of HDO and HTO. Negative charges on soil surfaces repel chloride and bromide. The effect of charge exclusion on movement of Cl - and Br - relative to HDO was measured in small columns for a number of soils from the southwest of Western Australia. Data from these experiments show that in the unsaturated zone of sandy soils, charge exclusion can reduce the pore volume available to Cl - and Br - in the water phase at field capacity by > 20%. Recharge to ground water, if calculated from the position of Cl - or Br - tracers and average moisture in the soil profile, must then be reduced by the same percentage. The effect of charge exclusion in soils on the calculation of recharge from profile data, was evaluated for a practical situation. Significant amounts of bromide from car exhaust gases accumulate in soils in urban areas and can be used to trace water movement. A site was chosen in metropolitan Perth on a sparsely vegetated calcareous sand near the junction of two busy roads. A seasonal effect on bromide accumulation in the soil profile at this site was clearly visible from data on the soil solution. The distribution of bromide in the soil profile appears to correspond to 93% of rainfall recharging ground water. Correcting the data for charge exclusion, results in a calculated recharge of ? 70% of annual rainfall.

  13. Contributing recharge areas, groundwater travel time, and groundwater water quality of the Missouri River alluvial aquifer near the City of Independence, Missouri, well field, 1997-2008

    USGS Publications Warehouse

    Kelly, Brian P.

    2011-01-01

    The City of Independence, Missouri, operates a well field in the Missouri River alluvial aquifer. Contributing recharge areas (CRA) were last determined for the well field in 1996. Since that time, eight supply wells have been installed in the area north of the Missouri River and well pumpage has changed for the older supply wells. The change in pumping has altered groundwater flow and substantially changed the character of the CRA and groundwater travel times to the supply wells. The U.S Geological Survey, in a cooperative study with the City of Independence, Missouri, simulated steady-state groundwater flow for 2007 well pumpage, average annual river stage, and average annual recharge. Particle-tracking analysis was used to determine the CRA for supply wells and monitoring wells, and the travel time from recharge areas to supply wells, recharge areas to monitoring wells, and monitoring wells to supply wells. The simulated CRA for the well field is elongated in the upstream direction and extends to both sides of the Missouri River. Groundwater flow paths and recharge areas estimated for monitoring wells indicate the origin of water to each monitoring well, the travel time of that water from the recharge area, the flow path from the vicinity of each monitoring well to a supply well, and the travel time from the monitoring well to the supply well. Monitoring wells 14a and 14b have the shortest groundwater travel time from their contributing recharge area of 0.30 years and monitoring well 29a has the longest maximum groundwater travel time from its contributing recharge area of 1,701 years. Monitoring well 22a has the shortest groundwater travel time of 0.5 day to supply well 44 and monitoring well 3b has the longest maximum travel time of 31.91 years to supply well 10. Water-quality samples from the Independence groundwater monitoring well network were collected from 1997 to 2008 by USGS personnel during ongoing annual sampling within the 10-year contributing recharge area (CRA) of the Independence well field. Statistical summaries and the spatial and temporal variability of water quality in the Missouri River alluvial aquifer near the Independence well field were characterized from analyses of 598 water samples. Water-quality constituent groups include dissolved oxygen and physical properties, nutrients, major ions and trace elements, wastewater indicator compounds, fuel compounds, and total benzene, toluene, ethylbenzene, and xylene (BTEX), alachlor, and atrazine. The Missouri Secondary Maximum Contaminant Level (SMCL) for iron was exceeded in almost all monitoring wells. The Missouri Maximum Contaminant Level (MCL) for arsenic was exceeded 32 times in samples from monitoring wells. The MCL for barium was exceeded five times in samples from one monitoring well. The SMCL for manganese was exceeded 160 times in samples from all monitoring wells and the combined well-field sample. The most frequently detected wastewater indicator compounds were N,N-diethyl-meta-toluamide (DEET), phenol, caffeine, and metolachlor. The most frequently detected fuel compounds were toluene and benzene. Alachlor was detected in 22 samples and atrazine was detected in 37 samples and the combined well-field sample. The MCL for atrazine was exceeded in one sample from one monitoring well. Samples from monitoring wells with median concentrations of total inorganic nitrogen larger than 1 milligram per liter (mg/L) are located near agricultural land and may indicate that agricultural land practices are the source of nitrogen to groundwater. Largest median values of specific conductance; total inorganic nitrogen; dissolved calcium, magnesium, sodium, iron, arsenic, manganese, bicarbonate, and sulfate and detections of wastewater indicator compounds generally were in water samples from monitoring wells with CRAs that intersect the south bank of the Missouri River. Zones of higher specific conductance were located just upstream from the Independen

  14. Reconnaissance Estimates of Recharge Based on an Elevation-dependent Chloride Mass-balance Approach

    SciTech Connect

    Charles E. Russell; Tim Minor

    2002-08-31

    Significant uncertainty is associated with efforts to quantity recharge in arid regions such as southern Nevada. However, accurate estimates of groundwater recharge are necessary to understanding the long-term sustainability of groundwater resources and predictions of groundwater flow rates and directions. Currently, the most widely accepted method for estimating recharge in southern Nevada is the Maxey and Eakin method. This method has been applied to most basins within Nevada and has been independently verified as a reconnaissance-level estimate of recharge through several studies. Recharge estimates derived from the Maxey and Eakin and other recharge methodologies ultimately based upon measures or estimates of groundwater discharge (outflow methods) should be augmented by a tracer-based aquifer-response method. The objective of this study was to improve an existing aquifer-response method that was based on the chloride mass-balance approach. Improvements were designed to incorporate spatial variability within recharge areas (rather than recharge as a lumped parameter), develop a more defendable lower limit of recharge, and differentiate local recharge from recharge emanating as interbasin flux. Seventeen springs, located in the Sheep Range, Spring Mountains, and on the Nevada Test Site were sampled during the course of this study and their discharge was measured. The chloride and bromide concentrations of the springs were determined. Discharge and chloride concentrations from these springs were compared to estimates provided by previously published reports. A literature search yielded previously published estimates of chloride flux to the land surface. {sup 36}Cl/Cl ratios and discharge rates of the three largest springs in the Amargosa Springs discharge area were compiled from various sources. This information was utilized to determine an effective chloride concentration for recharging precipitation and its associated uncertainty via Monte Carlo simulations. Previously developed isohyetal maps were utilized to determine the mean and standard deviation of precipitation within the area. A digital elevation model was obtained to provide elevation information. A geologic model was obtained to provide the spatial distribution of alluvial formations. Both were used to define the lower limit of recharge. In addition, 40 boreholes located in alluvial sediments were drilled and sampled in an attempt to support the argument that the areal distribution of alluvial sediments can be used to define a zone of negligible recharge. The data were compiled in a geographic information system and used in a Monte Carlo analysis to determine recharge occurring within the study area. Results of the analysis yielded estimates of the mean and standard deviation of recharge occurring within the study area (28.168 x 10{sup 6} m{sup 3} yr{sup -1} and 7.008 x 10{sup 6} m{sup 3} yr{sup -1}, and 26.838 x 10{sup 6} m{sup 3} yr{sup -1} and 6.928 x 10{sup 6} m{sup 3} yr{sup -1}) for two sets of simulations using alternate definitions of the lower limit of recharge. A sensitivity analysis determined the recharge estimates were most sensitive to uncertainty associated with the chloride concentration of the spring discharge. The second most sensitive parameter was the uncertainty associated with the mean precipitation within the recharge areas. Comparison of the analysis to previously published estimates of recharge revealed mixed results with the recharge estimates derived during the course of this project generally greater relative to previously published estimates.

  15. Estimating recharge through Playa Lakes to the Southern High Plains Aquifer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the Southern High Plains of Texas, it is accepted that focused recharge to the High Plains Aquifer (locally known as the Ogallala) occurs through over 20,000 playa lakes, which are local depressions that collect storm runoff. The amount and rate of recharge is not precisely known, and the impact ...

  16. COMPARATIVE LIFE CYCLE ASSESSMENT OF ALCALINE CELLS AND NI-MH RECHARGEABLE BATTERIES

    E-print Network

    Paris-Sud XI, Université de

    Page 1 COMPARATIVE LIFE CYCLE ASSESSMENT OF ALCALINE CELLS AND NI-MH RECHARGEABLE BATTERIES Jean by applying the LCA methodology to evaluate the environmental footprint of alkaline cells and Ni-MH batteries phase. Besides, the emphasis on rechargeable batteries is only justified from an environmental point

  17. Likely recharge to permanent groundwater beneath future rehabilitated landforms at Ranger uranium mine, northern Australia

    Microsoft Academic Search

    P. H. Woods

    1994-01-01

    The magnitude of recharge beneath rehabilitated landforms at former mine sites is one of many variables required for a comprehensive assessment of potential future environmental impacts of those sites. The magnitude of net groundwater recharge that may occur on the rehabilitated Range Uranium Mines landform is estimated to be of the order of 2–5% of the incident rainfall, that is,

  18. HYDRUS-1D Modeling of an Irrigated Agricultural Plot with Application to Aquifer Recharge Estimation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A variety of methods are available for estimating aquifer recharge in semi-arid regions, each with advantages and disadvantages. We are investigating a procedure for estimating recharge in an irrigated basin. The method involves computing irrigation return flows based on HYDRUS-1D modeling of root z...

  19. Combinatorial investigations of advanced Li-ion rechargeable battery electrode materials

    Microsoft Academic Search

    M D Fleischauer; T D Hatchard; A Bonakdarpour; J R Dahn

    2005-01-01

    Future advances in Li-ion rechargeable battery performance are strongly linked to improved electrode materials. Candidate materials for the negative electrode of the future generally contain multiple elements and broad composition ranges. There are surprisingly few published accounts of combinatorial investigations of Li-ion rechargeable battery electrode materials. This paper describes the combinatorial infrastructure of the Dahn group at Dalhousie University as

  20. Transient-boundary voltage method for measurement of equivalent circuit components of rechargeable batteries

    Microsoft Academic Search

    K. H. Norian

    A method is presented for measuring the equivalent circuit components of rechargeable batteries. The temporal discharge–rest–charge–rest sequence of a rechargeable battery is described, using the principles of transient circuit analysis, to derive equations for the battery voltage as a function of time during voltage transients and at the boundaries at transitions between transient phases. The equations lead to a new

  1. Fullerenes: non-transition metal clusters as rechargeable magnesium battery cathodes.

    PubMed

    Zhang, Ruigang; Mizuno, Fuminori; Ling, Chen

    2015-01-21

    We discovered that non-transition metal clusters have great potential as rechargeable Mg battery cathodes. Fullerene (C60), one of the prototype materials, was discharged and recharged with a remarkable rate capability. This unique rate performance is attributed to its capability to delocalize electrons on the entire cluster rather than to individual atoms. PMID:25461490

  2. Discrete-storm water-table fluctuation method to estimate episodic recharge.

    USGS Publications Warehouse

    Nimmo, John R.; Horowittz, Charles; Mitchell, Lara

    2015-01-01

    We have developed a method to identify and quantify recharge episodes, along with their associated infiltration-related inputs, by a consistent, systematic procedure. Our algorithm partitions a time series of water levels into discrete recharge episodes and intervals of no episodic recharge. It correlates each recharge episode with a specific interval of rainfall, so storm characteristics such as intensity and duration can be associated with the amount of recharge that results. To be useful in humid climates, the algorithm evaluates the separability of events, so that those whose recharge cannot be associated with a single storm can be appropriately lumped together. Elements of this method that are subject to subjectivity in the application of hydrologic judgment are values of lag time, fluctuation tolerance, and master recession parameters. Because these are determined once for a given site, they do not contribute subjective influences affecting episode-to-episode comparisons. By centralizing the elements requiring scientific judgment, our method facilitates such comparisons by keeping the most subjective elements openly apparent, making it easy to maintain consistency. If applied to a period of data long enough to include recharge episodes with broadly diverse characteristics, the method has value for predicting how climatic alterations in the distribution of storm intensities and seasonal duration may affect recharge.

  3. Data-Conditioned Distributions of Groundwater Recharge Under Climate Change Scenarios

    Microsoft Academic Search

    D. McLaughlin; G. C. Ng; D. Entekhabi; B. Scanlon

    2008-01-01

    Groundwater recharge is likely to be impacted by climate change, with changes in precipitation amounts altering moisture availability and changes in temperature affecting evaporative demand. This could have major implications for sustainable aquifer pumping rates and contaminant transport into groundwater reservoirs in the future, thus making predictions of recharge under climate change very important. Unfortunately, in dry environments where groundwater

  4. EVALUATING UNCERTAINTIES IN GROUND-WATER RECHARGE ESTIMATES THROUGH ADVANCED MONITORING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Risk, as estimated by many multimedia environmental models, is highly sensitive to infiltration and ground-water recharge. This field study used high-frequency monitoring of vadose-zone water content and piezometric levels to build confidence in modeling of infiltration and ground-water recharge. ...

  5. Estimating recharge thresholds in tropical karst island aquifers: Barbados, Puerto Rico and Guam

    E-print Network

    Banner, Jay L.

    Estimating recharge thresholds in tropical karst island aquifers: Barbados, Puerto Rico and Guam of rainfall. The karst aquifers on Barbados, Guam and Puerto Rico have similar rainwater and groundwater therefore speculate that similar recharge-rainfall thresholds may be observed in other tropical karst

  6. Estimation of groundwater recharge to chalk and sandstone aquifers using simple soil models

    Microsoft Academic Search

    R. Ragab; J. Finch; R. Harding

    1997-01-01

    On the assumption that the water draining below the root zone is potentially available for groundwater recharge, two current UK methods for estimating annual groundwater recharge have been compared with a new soil model using data from four sites under permanent grass in the UK: two sites representative of the Chalk aquifer at Bridgest Farm (Hampshire) and Fleam Dyke (Cambridgeshire),

  7. Setting up a groundwater recharge model for an arid karst system using time lapse camera data

    NASA Astrophysics Data System (ADS)

    Schulz, Stephan; de Rooij, Gerrit H.; Michelsen, Nils; Rausch, Randolf; Siebert, Christian; Schüth, Christoph; Merz, Ralf

    2015-04-01

    Groundwater is the principal water resource in most dryland areas. Therefore, its replenishment rate is of great importance for water management. The amount of groundwater recharge depends on the climatic conditions, but also on the geological conditions, soil properties and vegetation. In dryland areas, outcrops of karst aquifers often receive enhanced recharge rates compared to other geological settings. Especially in areas with exposed karst features like sinkholes or open shafts rainfall accumulates in channels and discharges directly into the aquifer. Using the example of the As Sulb plateau in Saudi Arabia this study introduces a cost-effective and robust method for recharge monitoring and modelling in karst outcrops. The measurement of discharge of a small catchment (4.0 x 104 m2) into a sinkhole, and hence the direct recharge into the aquifer, was carried out with a time lapse camera observing a v-notch weir. During the monitoring period of two rainy seasons (autumn 2012 to spring 2014) four recharge events were recorded. Afterwards, recharge data as well as proxy data about the drying of the sediment cover are used to set up a conceptual water balance model. This model was run for 17 years (1971 to 1986 and 2012 to 2014). Simulation results show highly variable seasonal recharge-precipitation-ratios, which underlines the nonlinearity between recharge and precipitation in dryland areas. Besides the amount of precipitation this ratio is strongly influenced by the interannual distribution of rainfall events.

  8. Intrinsically safe 5-V, 4-A: Rechargeable power supply. Information circular\\/1989

    Microsoft Academic Search

    Sammarco

    1989-01-01

    The U.S. Bureau of Mines has developed a regulated, intrinsically safe, rechargeable power supply for portable electronic equipment for underground use. The regulated output is ideal for microprocessor power requirements and is suited for operation in hazardous environments. Two rechargeable, sealed batteries are contained within the power supply. Provisions are made to use an external source of power if these

  9. Inferring time-varying recharge from inverse analysis of long-term water levels

    USGS Publications Warehouse

    Dickinson, J.E.; Hanson, R.T.; Ferre, T. P. A.; Leake, S.A.

    2004-01-01

    Water levels in aquifers typically vary in response to time-varying rates of recharge, suggesting the possibility of inferring time-varying recharge rates on the basis of long-term water level records. Presumably, in the southwestern United States (Arizona, Nevada, New Mexico, southern California, and southern Utah), rates of mountain front recharge to alluvial aquifers depend on variations in precipitation rates due to known climate cycles such as the El Nin??o-Southern Oscillation index and the Pacific Decadal Oscillation. This investigation examined the inverse application of a one-dimensional analytical model for periodic flow described by Lloyd R. Townley in 1995 to estimate periodic recharge variations on the basis of variations in long-term water level records using southwest aquifers as the case study. Time-varying water level records at various locations along the flow line were obtained by simulation of forward models of synthetic basins with applied sinusoidal recharge of either a single period or composite of multiple periods of length similar to known climate cycles. Periodic water level components, reconstructed using singular spectrum analysis (SSA), were used to calibrate the analytical model to estimate each recharge component. The results demonstrated that periodic recharge estimates were most accurate in basins with nearly uniform transmissivity and the accuracy of the recharge estimates depends on monitoring well location. A case study of the San Pedro Basin, Arizona, is presented as an example of calibrating the analytical model to real data.

  10. ASSESSMENT OF NATURAL GROUND WATER RECHARGE IN UPPER GANGA CANAL COMMAND AREA

    E-print Network

    Kumar, C.P.

    ASSESSMENT OF NATURAL GROUND WATER RECHARGE IN UPPER GANGA CANAL COMMAND AREA C. P. Kumar* and P. V. Seethapathi** SYNOPSIS Quantification of the rate of natural ground water recharge is a pre-requisite for efficient ground water resource management. It is particularly important in regions with large demands

  11. Statistical analysis of hydrographs and water-table fluctuation to estimate groundwater recharge

    Microsoft Academic Search

    Sang-Ki Moon; Nam C Woo; Kwang S Lee

    2004-01-01

    Using water-table monitoring data from the National Groundwater Monitoring Network in Korea, groundwater hydrographs were classified into five typical groups. Then, to estimate groundwater recharge, a modified water-table fluctuation (WTF) method was developed from the relation between the cumulative WTF and corresponding precipitation records. Applying this method to different types of hydrographs, the spatial variability of recharge in river basins

  12. A numerical analysis on the applicability of the water level fluctuation method for quantifying groundwater recharge

    Microsoft Academic Search

    M. Koo; D. Lee

    2002-01-01

    The water table fluctuation(WTF) method is a conventional method for quantifying groundwater recharge by multiplying the specific yield to the water level rise. Based on the van Genuchten model, an analytical relationship between groundwater recharge and the water level rise is derived. The equation is used to analyze the effects of the depth to water level and the soil properties

  13. A method of estimating spatio-temporally distributed groundwater recharge using integrated surface-subsurface modelling

    Microsoft Academic Search

    Il Moon Chung; Nam Won Kim; Jeongwoo Lee; Marios Sophocleous

    2010-01-01

    In general, there have been various methods of estimating groundwater recharge such as baseflow separation approaches, water budget analyses based on lumped conceptual models, and the water table fluctuation method (WTF) by using data from groundwater monitoring wells. However, groundwater recharge rates show spatial-temporal variability due to climatic conditions, land use, and hydrogeological heterogeneity, so these methods have various limitations

  14. Well Catchments and Time-of-Travel Zones in Aquifers With Recharge

    Microsoft Academic Search

    David N. Lerner

    1992-01-01

    The classical analytical method used to map catchments and time-of-travel zones of pumping wells was originally derived for another purpose and takes no account of recharge (Bear and Jacobs, 1965). Generalized catchment shapes are presented here for aquifers with recharge. They can be scaled to field situations through two or three nondimensional parameters. A semianalytical path line tracing model was

  15. Well catchments and time-of-travel zones in aquifers with recharge

    Microsoft Academic Search

    David N. Lerner

    1992-01-01

    The classical analytical method used to map catchments and time-of-travel zones of pumping wells was originally derived for another purpose and takes no account of recharge (Bear and Jacobs, 1965). Generalized catchment shapes are presented here for aquifers with recharge. They can be scaled to field situations through two or three nondimensional parameters. A semianalytical path line tracing model was

  16. Evaluation of cellulose-based separators in cycle and wet life testing of alkaline rechargeable cells

    Microsoft Academic Search

    Harlan L. Lewis; William R. Johnson

    1996-01-01

    A study has been established to determine the dependence of cell cycle and wet life on the source material and composition of cellulose-based separator materials in alkaline rechargeable cells. Silver-zinc rechargeable cells of 28 Ahr capacity, identical in every respect except for the separator composition, are being tested in statistically significant numbers under identical temperature and relative humidity conditions, with

  17. MODIS-aided statewide net groundwater-recharge estimation in Nebraska.

    PubMed

    Szilagyi, Jozsef; Jozsa, Janos

    2013-01-01

    Monthly evapotranspiration (ET) rates (2000 to 2009) across Nebraska at about 1-km resolution were obtained by linear transformations of the MODIS (MODerate resolution Imaging Spectroradiometer) daytime surface temperature values with the help of the Priestley-Taylor equation and the complementary relationship of evaporation. For positive values of the mean annual precipitation and ET differences, the mean annual net recharge was found by an additional multiplication of the power-function-transformed groundwater vulnerability DRASTIC-code values. Statewide mean annual net recharge became about 29 mm (i.e., 5% of mean annual precipitation) with the largest recharge rates (in excess of 100 mm/year) found in the eastern Sand Hills and eastern Nebraska. Areas with the largest negative net recharge rates caused by declining groundwater levels due to large-scale irrigation are found in the south-western region of the state. Error bounds of the estimated values are within 10% to 15% of the corresponding precipitation rates and the estimated net recharge rates are sensitive to errors in the precipitation and ET values. This study largely confirms earlier base-flow analysis-based statewide groundwater recharge estimates when considerations are made for differences in the recharge definitions. The current approach not only provides better spatial resolution than available earlier studies for the region but also quantifies negative net recharge rates that become especially important in numerical modeling of shallow groundwater systems. PMID:23216050

  18. MODIS-Aided Statewide Net Groundwater-Recharge Estimation in Nebraska

    E-print Network

    Szilagyi, Jozsef

    -function-transformed groundwater vulnerability DRASTIC-code values. Statewide mean annual net recharge became about 29 mm (i.e., 5MODIS-Aided Statewide Net Groundwater-Recharge Estimation in Nebraska by Jozsef Szilagyi1 by declining groundwater levels due to large-scale irrigation are found in the south-western region

  19. Prospects for enhanced groundwater recharge via infiltration of urban storm water runoff: A case study

    Microsoft Academic Search

    W. D. Shuster; R. Gehring; J. Gerken

    The rain garden is an urban storm water best management practice that is used to infiltrate runoff close to its source, thereby disconnecting impervious area while providing an avenue for groundwater recharge. Groundwater recharge may provide additional benefits to aquatic ecosystems via enhancement of stream base flow. Yet, soil conditions can impact on certain aspects of rain garden performance and

  20. PROSPECTS FOR ENHANCED GROUNDWATER RECHARGE VIA INFILTRATION OF URBAN STORMWATER RUNOFF: A CASE STUDY

    EPA Science Inventory

    The rain garden is an urban storm water best management practice that is used to infiltrate runoff close to its source, thereby disconnecting impervious area while providing an avenue for groundwater recharge. Groundwater recharge may provide additional benefits to aquatic ecosys...

  1. Recharge Rates and Chemistry Beneath Playas of the High Plains Aquifer - A Literature Review and Synthesis

    USGS Publications Warehouse

    Gurdak, Jason J.; Roe, Cassia D.

    2009-01-01

    Playas are ephemeral, closed-basin wetlands that are important zones of recharge to the High Plains (or Ogallala) aquifer and critical habitat for birds and other wildlife in the otherwise semiarid, shortgrass prairie and agricultural landscape. The ephemeral nature of playas, low regional recharge rates, and a strong reliance on ground water from the High Plains aquifer has prompted many questions regarding the contribution of recharge from playas to the regional aquifer. To address these questions and concerns, the U.S. Geological Survey, in cooperation with the Playa Lakes Joint Venture, present a review and synthesis of the more than 175 publications about recharge rates and chemistry beneath playas and interplaya settings. Although a number of questions remain regarding the controls on recharge rates and chemistry beneath playas, the results from most published studies indicate that recharge rates beneath playas are substantially (1 to 2 orders of magnitude) higher than recharge rates beneath interplaya settings. The synthesis presented here supports the conceptual model that playas are important zones of recharge to the High Plains aquifer and are not strictly evaporative pans. The major findings of this synthesis yield science-based implications for the protection and management of playas and ground-water resources of the High Plains aquifer and directions for future research.

  2. Real-time Scheduling of periodic tasks in a monoprocessor system with rechargeable energy storage

    E-print Network

    Paris-Sud XI, Université de

    such as a solar panel or a furl cell, and a rechargeable energy storage such as a battery or a super- capacitor that the wasted recharging energy is minimized and the battery level is at all times within two limits, starting

  3. A new approach to delineate the groundwater recharge zone in hard rock terrain

    Microsoft Academic Search

    N. C. Mondal; V. S. Singh

    Delineation of potential groundwater recharge zone is vital to augment groundwater resources in hard rock terrain. It is also important for the sustainable deve - lopment and management of groundwater resources. Conventionally, suitable zone for potential groundwater recharge is deciphered using tritium injection, hydro - geological, geophysical geomorphological maps and regional groundwater model, which are often time consuming and uneconomical.

  4. Remote Sensing and GIS Techniques to map Groundwater Recharge and Discharge

    Microsoft Academic Search

    S. Tweed; M. Leblanc; J. Webb; M. Lubczynski; F. Stagnitti

    2006-01-01

    In salinity prone catchments, effective management of water resources involves balancing the requirements of sustainable resource allocation with salinity mitigation programs and ecosystem protection. Understanding groundwater recharge and discharge processes is a key component to achieving this balance. In this study, surface and sub-surface features are linked with recharge and discharge processes by incorporating GIS and remote sensing mapping techniques

  5. A solution to the problem of optimizing the fuel bias for a liquid propellant rocket by an application of the central limit theorem

    NASA Technical Reports Server (NTRS)

    Viera, W. J.

    1974-01-01

    A method of determining the fuel bias for a bipropellant liquid rocket that minimizes outage associated penalties on payload potential is presented. A fuel bias so derived is normally called the optimum fuel bias. The subjects discussed are: (1) probability density function of outage, (2) computer program listing, and (3) choosing the optimum fuel bias.

  6. An assessment of recharge possibility to North-Western Sahara Aquifer System (NWSAS) using environmental isotopes

    NASA Astrophysics Data System (ADS)

    Al-Gamal, Samir Anwar

    2011-02-01

    SummaryA comprehensive understanding of the groundwater dynamics of a transboundary aquifer system is highly needed for any successful transboundary cooperation policy. Moreover, an analysis of the NWSAS can be of particular interest for policy makers and researchers. This paper aims to reveals and to assess the renewability of North-Western Sahara Aquifer System (NWSAS) as one of the major transboundary multi-layered aquifer system, in North Africa, shared by Algeria, Tunisia, and Libya and is often referred to as the Système Aquifère du Sahara Septentrional (SASS). The paper is primarily intended for exploring whether it receives a considerable fraction of modern water as recharge or it is at risk of being depleted and excessively pumped, where the main challenge for NWSAS, is that it should be abstracted rationally for equitable use. Environmental isotopes data of ? 18O, ? 2H, 3H, 14C as well as characteristics of d-excess are used to illustrate whether NSWAS is renewable or non-renewable resource. Geochemical, hydrological and statistical evidences supporting the renewability of NWSAS are provided through pairs of cross-plots. The study has clearly indicated that NWSAS is receiving a considerable fraction of modern water as recharge to the aquifer because of the following reasons: Firstly, the moderately depleted delta values of ? 18O and ? 2H of water from Sahara Atlas in Algeria and the Dahar and the Dj. Nefoussa in Tunisia and Libya with ? 18O content (-6.0‰ to -5.0‰) compared with that of palaeowater (-7.0‰ to -9.0‰) indicate an appreciable fraction of modern water recharging NWSAS. This appreciable fraction of modern water should be attributed to originate from the present-day precipitation (-6.5‰). Secondly, the presence of significant amount of 14C > 2% and 3H > 5 TU, frequently found in data should be attributed to a mixing with shallow and modern water, where old water practically contains no 14C. The foregoing facts are in good agreement with the results of conventional hydrologic approach. This would contradict the assumption that the NWSAS is non-renewable water resource. In this context, the NWSAS is being located in one of the driest regions on the planet; these huge resources have been recognized to be of great importance to the socio-economic development of its riparian countries. So the present paper addresses the necessity of identifying specific cooperation problems which evolve out of these hydro geological attributes and prevalent use patterns. Accordingly, the description of NWSAS as non-renewable, devoid of any meaningful recharge, a rather stagnant water body, disconnected from any surface water body in addition to its classification as "non-renewable" would therefore be misleading and represents one of the most obvious inaccuracy as well.

  7. 1/12/14 Researchers Develop Micro-Windmills to Recharge Cell Phones www.sciencespacerobots.com/researchers-develop-micro-windmills-to-recharge-cell-phones-11020142 1/2

    E-print Network

    Chiao, Jung-Chih

    1/12/14 Researchers Develop Micro-Windmills to Recharge Cell Phones www.sciencespacerobots.com/researchers-develop-micro-windmills-to-recharge-cell-phones-Windmills to Recharge Cell Phones A University of Texas at Arlington research associate and electrical engineering be used to charge cell phone batteries by embedding hundreds of them in a cell phone sleeve

  8. 2/17/2014 TechnologyUses Micro-Windmills to Recharge Cell Phones http://powerelectronics.com/print/blog/technology-uses-micro-windmills-recharge-cell-phones?group_id=17022 1/2

    E-print Network

    Chiao, Jung-Chih

    2/17/2014 TechnologyUses Micro-Windmills to Recharge Cell Phones http://powerelectronics.com/print/blog/technology-uses-micro-windmills-recharge-cell-phones?group_id=17022 1/2 print | close Technology Uses Micro-Windmills to Recharge Cell Phones Fri, 2014-01-24 14:30 A UT Arlington (Texas) research

  9. 1/14/14 Technologyuses micro-windmills to recharge cell phones www.rdmag.com/news/2014/01/technology-uses-micro-windmills-recharge-cell-phones 1/10

    E-print Network

    Chiao, Jung-Chih

    1/14/14 Technologyuses micro-windmills to recharge cell phones www.rdmag.com/news/2014/01/technology-uses-micro-windmills-recharge-cell-phones 1/10 ADVERTISEMENT LOG IN REGISTERFIND MY COMPANY News ADVERTISEMENT Technology uses micro-windmills to recharge cell phones Mon, 01/13/2014 - 9:06am Get today's R

  10. Clogging in Managed Aquifer Recharge: Hydrodynamics and Geochemistry

    NASA Astrophysics Data System (ADS)

    Mays, D. C.

    2013-12-01

    Managed aquifer recharge (MAR) is the engineered process by which water is delivered into an aquifer for storage, transmission, or treatment. Perhaps the most significant technical challenge in MAR is clogging, a detrimental reduction of permeability in the aquifer porous media. This presentation describes research from the allied fields of water treatment, soil science, and petrology, each of which sheds light on the mechanisms by which hydrodynamics and geochemistry influence clogging in MAR. The primary focus is clogging by suspended solids, especially clay colloids, which are ubiquitous in natural porous media. When colloids deposit in aquifers, they reduce the effective porosity and alter the pore space geometry, both of which can inhibit the flow of groundwater. Management of clogging is complicated by the complexity inherent in this system, in which hydrodynamics, geochemistry, clay mineralogy, and colloidal effects each play a role. This presentation will briefly review colloid filtration, mobilization, and clogging models, then highlight the key physical and chemical variables that control clogging. It will be argued that clogging in managed aquifer recharge is analogous to clogging in soils or hydrocarbon reservoirs, rather than to clogging in granular media filters used for water treatment. Based on this analogy, the presentation will conclude with several recommendations to prevent or manage clogging in MAR.

  11. Natural water purification and water management by artificial groundwater recharge

    PubMed Central

    Balke, Klaus-Dieter; Zhu, Yan

    2008-01-01

    Worldwide, several regions suffer from water scarcity and contamination. The infiltration and subsurface storage of rain and river water can reduce water stress. Artificial groundwater recharge, possibly combined with bank filtration, plant purification and/or the use of subsurface dams and artificial aquifers, is especially advantageous in areas where layers of gravel and sand exist below the earth’s surface. Artificial infiltration of surface water into the uppermost aquifer has qualitative and quantitative advantages. The contamination of infiltrated river water will be reduced by natural attenuation. Clay minerals, iron hydroxide and humic matter as well as microorganisms located in the subsurface have high decontamination capacities. By this, a final water treatment, if necessary, becomes much easier and cheaper. The quantitative effect concerns the seasonally changing river discharge that influences the possibility of water extraction for drinking water purposes. Such changes can be equalised by seasonally adapted infiltration/extraction of water in/out of the aquifer according to the river discharge and the water need. This method enables a continuous water supply over the whole year. Generally, artificially recharged groundwater is better protected against pollution than surface water, and the delimitation of water protection zones makes it even more save. PMID:18357624

  12. Impact of Large-scale Geological Architectures On Recharge

    NASA Astrophysics Data System (ADS)

    Troldborg, L.; Refsgaard, J. C.; Engesgaard, P.; Jensen, K. H.

    Geological and hydrogeological data constitutes the basis for assessment of ground- water flow pattern and recharge zones. The accessibility and applicability of hard ge- ological data is often a major obstacle in deriving plausible conceptual models. Nev- ertheless focus is often on parameter uncertainty caused by the effect of geological heterogeneity due to lack of hard geological data, thus neglecting the possibility of alternative conceptualizations of the large-scale geological architecture. For a catchment in the eastern part of Denmark we have constructed different geologi- cal models based on different conceptualization of the major geological trends and fa- cies architecture. The geological models are equally plausible in a conceptually sense and they are all calibrated to well head and river flow measurements. Comparison of differences in recharge zones and subsequently well protection zones emphasize the importance of assessing large-scale geological architecture in hydrological modeling on regional scale in a non-deterministic way. Geostatistical modeling carried out in a transitional probability framework shows the possibility of assessing multiple re- alizations of large-scale geological architecture from a combination of soft and hard geological information.

  13. Development of new safe electrode for lithium rechargeable battery

    NASA Astrophysics Data System (ADS)

    Kise, Makiko; Yoshioka, Shoji; Hamano, Kouji; Takemura, Daigo; Nishimura, Takashi; Urushibata, Hiroaki; Yoshiyasu, Hajimu

    A new concept cathode was proposed to improve the safety of lithium rechargeable batteries. The cathode contains a positive temperature coefficient (PTC) compound that can drastically increase resistivity at more than a specified temperature (PTC properties). A PTC cathode containing the PTC compound was fabricated and its resistivity was evaluated. The resistivity of PTC cathodes increased by several tens at 130-140 °C, which is the melting point of polyethylene. In lithium rechargeable batteries using these cathodes (PTC cell), a level nearly reaching the designed capacity is obtained at less than 1 C rate. The discharge capacity of PTC cells became high as the content of PTC compound increases. Moreover, under 3 C discharge condition, the voltage of PTC cell dropped at 138 °C where the resistivity of the PTC cathode drastically increased. Additionally, on the external short circuit test at 145 °C, the short circuit current of the PTC cell was almost 0 A. These results indicate that PTC cathodes will improve the battery safety.

  14. Recharge and sustainability of a coastal aquifer in northern Albania

    NASA Astrophysics Data System (ADS)

    Kumanova, X.; Marku, S.; Fröjdö, S.; Jacks, G.

    2014-06-01

    The River Mati in Albania has formed a coastal plain with Holocene and Pleistocene sediments. The outer portion of the plain is clay, with three underlying aquifers that are connected to an alluvial fan at the entry of the river into the plain. The aquifers supply water for 240,000 people. Close to the sea the aquifers are brackish. The brackish water is often artesian and found to be thousands of years old. Furthermore, the salinity, supported by ?18O results, does not seem to be due to mixing with old seawater but due to diffusion from intercalated clay layers. Heavy metals from mines in the upstream section of River Mati are not an immediate threat, as the pH buffering of the river water is good. Moreover, the heavy metals are predominantly found in suspended and colloidal phases. Two sulphur isotope signatures, one mirroring seawater sulphate in the brackish groundwater (?34S >21 ‰) and one showing the influence of sulphide in the river and the fresh groundwater (?34S <10 ‰), indicate that the groundwater in the largest well field is recharged from the river. The most serious threat is gravel extraction in the alluvial fan, decreasing the hydraulic head necessary for recharge and causing clogging of sediments.

  15. 3H and 14C as tracers of ground-water recharge

    USGS Publications Warehouse

    Izbicki, John A.; Michel, Robert L.; Martin, Peter

    1992-01-01

    Surface spreading of water from the Santa Clara River is used to recharge aquifers underlying the Oxnard Plain. These aquifers are divided into an upper system about 400 feet thick, and a lower system more than 1,000 feet thick. In previous studies, it has been reported that surface spreading recharged aquifers in both the upper and lower systems. Water from most wells perforated in the upper system has tritium levels consistent with decay-corrected concentrations found in water recharged after 1952 when tritium levels increased as a result of atmospheric testing of nuclear weapons. Water from most wells in the lower system does not contain measurable tritium and must have been recharged prior to 1952. Carbon-14 ages estimated for water from wells in the lower system range from recent to about 25,000 years before present. These data show that the lower system is not effectively recharged by surface spreading.

  16. Measurement of groundwater recharge on eastern Long Island, New York, U.S.A.

    NASA Astrophysics Data System (ADS)

    Steenhuis, Tammo S.; Jackson, Craig D.; Kung, Samuel K. J.; Brutsaert, Wilfried

    1985-07-01

    Two methods were tested for their suitability to provide improved estimates of recharge in the region of eastern Long Island. The two methods tested consist, first, of measuring recharge with a direct application of Darcy's law in the vadose zone and, second, of calculating recharge by closure of the hydrologic budget equation with evaporation computed from micrometeorologic data. The recharge figure, now in general use, of 50% of the annual precipitation is a long-term average at best. Our measurements of recharge, which were performed during a three-year period, showed that the vertical flux past the 1 m depth was strongly dependent on both the time of the year and the precipitation amount. In late fall, winter and early spring a high percentage of the precipitation became recharge. During the summer months there was a small net upward movement of water past the 1 m depth. Precipitation during these months did not contribute to the annual recharge. It may be concluded from our measurements that in order to estimate recharge, special attention should be given to precipitation during the winter months. A better estimate for annual recharge than the current 50% of annual precipitation might be to take approximately 75-90% of the precipitation from October 15 until May 15. The two methods used for estimating recharge were labour intensive and required experienced technicians. Currently, one method cannot be recommended above the other. Both methods give a good estimate during the year except for the winter. The closure method using micrometeorological data gives a slightly higher estimate than the direct measurement method based on Darcy's law.

  17. Groundwater Recharge Processes Revealed By Multi-Tracers Approach in a Headwater, North China Plain

    NASA Astrophysics Data System (ADS)

    Sakakibara, K.; Tsujimura, M.; Song, X.; Zhang, J.

    2014-12-01

    Groundwater recharge variation in space and time is crucial for effective water management especially in arid/ semi-arid regions. In order to reveal comprehensive groundwater recharge processes in a catchment with a large topographical relief and seasonal hydrological variations, intensive field surveys were conducted at 4 times in different seasons in Wangkuai watershed, Taihang Mountains, which is a main groundwater recharge zone of North China Plain. The groundwater, spring, stream water and lake water were sampled, and inorganic solute constituents and stable isotopes of oxygen-18 and deuterium were determined on all water samples. Also, the stream flow rate was observed in stable state condition. The stable isotopic compositions, silica and bicarbonate concentrations in the groundwater show close values as those in the surface water, suggesting main groundwater recharge occurs from surface water at mountain-plain transitional zone throughout a year. Also, the deuterium and oxgen-18 in the Wangkuai reservoir and the groundwater in the vicinity of the reservoir show higher values, suggesting the reservoir water, affected by evaporation effect, seems to have an important role for the groundwater recharge in alluvial plain. For specifying the groundwater recharge area and quantifying groundwater recharge rate from the reservoir, an inversion analysis and a simple mixing model were applied in Wangkuai watershed using stable isotopes of oxygen-18 and deuterium. The model results show that groundwater recharge occurs dominantly at the altitude from 357 m to 738 m corresponding to mountain-plain transitional zone, and groundwater recharge rate by Wangkuai reservoir is estimated to be 2.4 % of total groundwater recharge in Wangkuai watershed.

  18. Quantification of groundwater recharge in a hard rock terrain of Orissa: a case study.

    PubMed

    Sethi, Ranu Rani; Kumar, A; Sharma, S P

    2009-01-01

    A study was carried out to select the best method to estimate groundwater recharge in a hard rock terrain. Various standard empirical methods, soil-moisture balance method, water table fluctuation (WTF) method and commonly adopted norms set by Groundwater Estimation Committee (GEC), Govt of India were used to estimate recharge for the Munijhara watershed in the Nayagarh block of Orissa (India). The empirical formulae gave recharge rates ranging from 13 cm to 32 cm/year with average of 22.4 cm and standard deviation of 5.34, independent of other influencing factors like soil, topography and geology. The soil-moisture balance study indicated that recharge is more dependent on the continuous heavy rainfall total annual volume of rainfall. Recharge was limited at up to 10 mm per day, possibly due to presence of hard rock below the soil surface. The rise in water table depth was 3.45 m to 5.35 m with a mean rise of 4.5 m during the year 2006-2007. Annual groundwater recharge based on the WTF approach varied from 10.3 to 16.85 cm with a mean of 13.5 cm, standard deviation of 1.57 cm and coefficient of variation 11.57%. This recharge accounted for 8 to 14% of rainfall received. With a water budget approach based on GEC norms, recharge was calculated as 17 cm per year. The study showed that the magnitudes of annual groundwater recharge as estimated by the WST method and GEC norms are in conformity with other recent findings in India under the same climate conditions. Based on the results recharge structures could be planned in suitable locations to reduce fallow areas under the watershed. PMID:19717920

  19. Comparison of local- to regional-scale estimates of ground-water recharge in Minnesota, USA

    NASA Astrophysics Data System (ADS)

    Delin, Geoffrey N.; Healy, Richard W.; Lorenz, David L.; Nimmo, John R.

    2007-02-01

    SummaryRegional ground-water recharge estimates for Minnesota were compared to estimates made on the basis of four local- and basin-scale methods. Three local-scale methods (unsaturated-zone water balance, water-table fluctuations (WTF) using three approaches, and age dating of ground water) yielded point estimates of recharge that represent spatial scales from about 1 to about 1000 m 2. A fourth method (RORA, a basin-scale analysis of streamflow records using a recession-curve-displacement technique) yielded recharge estimates at a scale of 10-1000s of km 2. The RORA basin-scale recharge estimates were regionalized to estimate recharge for the entire State of Minnesota on the basis of a regional regression recharge (RRR) model that also incorporated soil and climate data. Recharge rates estimated by the RRR model compared favorably to the local and basin-scale recharge estimates. RRR estimates at study locations were about 41% less on average than the unsaturated-zone water-balance estimates, ranged from 44% greater to 12% less than estimates that were based on the three WTF approaches, were about 4% less than the age dating of ground-water estimates, and were about 5% greater than the RORA estimates. Of the methods used in this study, the WTF method is the simplest and easiest to apply. Recharge estimates made on the basis of the UZWB method were inconsistent with the results from the other methods. Recharge estimates using the RRR model could be a good source of input for regional ground-water flow models; RRR model results currently are being applied for this purpose in USGS studies elsewhere.

  20. Lithologic influences on groundwater recharge through incised glacial till from profile to regional scales: Evidence from glaciated Eastern Nebraska

    NASA Astrophysics Data System (ADS)

    Gates, John B.; Steele, Gregory V.; Nasta, Paolo; Szilagyi, Jozsef

    2014-01-01

    Variability in sediment hydraulic properties associated with landscape depositional and erosional features can influence groundwater recharge processes by affecting soil-water storage and transmission. This study considers recharge to aquifers underlying river-incised glaciated terrain where the distribution of clay-rich till is largely intact in upland locations but has been removed by alluvial erosion in stream valleys. In a stream-dissected glacial region in eastern Nebraska (Great Plains region of the United States), recharge estimates were developed for nested profile, aquifer, and regional scales using unsaturated zone profile measurements (matric potentials, Cl- and 3H), groundwater tracers (CFC-12 and SF6), and a remote sensing-assisted water balance model. Results show a consistent influence of till lithology on recharge rates across nested spatial scales despite substantial uncertainty in all recharge estimation methods, suggesting that minimal diffuse recharge occurs through upland glacial till lithology whereas diffuse recharge occurs in river valleys where till is locally absent. Diffuse recharge is estimated to account for a maximum of 61% of total recharge based on comparison of diffuse recharge estimated from the unsaturated zone (0-43 mm yr-1) and total recharge estimated from groundwater tracers (median 58 mm yr-1) and water balance modeling (median 56 mm yr-1). The results underscore the importance of lithologic controls on the distributions of both recharge rates and mechanisms.

  1. Temporal and spatial scaling of hydraulic response to recharge in fractured aquifers: Insights from a frequency domain analysis

    E-print Network

    Paris-Sud XI, Université de

    Temporal and spatial scaling of hydraulic response to recharge in fractured aquifers: Insights from investigate the hydraulic response to recharge of a fractured aquifer, using a frequency domain approach level fluctuations as input and output respectively. The spatial variability of the response to recharge

  2. Reversible (unitized) PEM fuel cell devices

    SciTech Connect

    Mitlitsky, F; Myers, B; Smith, W F; Weisberg, Molter, T M

    1999-06-01

    Regenerative fuel cells (RFCs) are enabling for many weight-critical portable applications, since the packaged specific energy (>400 Wh/kg) of properly designed lightweight RFC systems is several-fold higher than that of the lightest weight rechargeable batteries. RFC systems can be rapidly refueled (like primary fuel cells), or can be electrically recharged (like secondary batteries) if a refueling infrastructure is not conveniently available. Higher energy capacity systems with higher performance, reduced weight, and freedom from fueling infrastructure are the features that RFCs promise for portable applications. Reversible proton exchange membrane (PEM) fuel cells, also known as unitized regenerative fuel cells (URFCs), or reversible regenerative fuel cells, are RFC systems which use reversible PEM cells, where each cell is capable of operating both as a fuel cell and as an electrolyzer. URFCs further economize portable device weight, volume, and complexity by combining the functions of fuel cells and electrolyzers in the same hardware, generally without any system performance or efficiency reduction. URFCs are being made in many forms, some of which are already small enough to be portable. Lawrence Livermore National Laboratory (LLNL) has worked with industrial partners to design, develop, and demonstrate high performance and high cycle life URFC systems. LLNL is also working with industrial partners to develop breakthroughs in lightweight pressure vessels that are necessary for URFC systems to achieve the specific energy advantages over rechargeable batteries. Proton Energy Systems, Inc. (Proton) is concurrently developing and commercializing URFC systems (UNIGEN' product line), in addition to PEM electrolyzer systems (HOGEN' product line), and primary PEM fuel cell systems. LLNL is constructing demonstration URFC units in order to persuade potential sponsors, often in their own conference rooms, that advanced applications based on URFC s are feasible. Safety and logistics force these URFC demonstration units to be small, transportable, and easily set up, hence they already prove the viability of URFC systems for portable applications.

  3. Zeolite in horizontal permeable reactive barriers for artificial groundwater recharge

    NASA Astrophysics Data System (ADS)

    Leal, María; Martínez-Hernández, Virtudes; Lillo, Javier; Meffe, Raffaella; de Bustamante, Irene

    2013-04-01

    The Spanish Water Reuse Royal Decree 1620/2007 considers groundwater recharge as a feasible use of reclaimed water. To achieve the water quality established in the above-mentioned legislation, a tertiary wastewater treatment is required. In this context, the infiltration of effluents generated by secondary wastewater treatments through a Horizontal Permeable Reactive Barrier (HPRB) may represent a suitable regeneration technology. Some nutrients (phosphate and ammonium) and some Pharmaceutical and Personal Care Products (PPCPs) are not fully removed in conventional wastewater treatment plants. To avoid groundwater contamination when effluents of wastewater treatments plants are used in artificial recharge activities, these contaminants have to be removed. Due to its sorption capacities, zeolite is among the most used reactive materials in Permeable Reactive Barrier (PRB). Therefore, the main goal of this study is to evaluate the zeolite retention effectiveness of nutrients and PPCPs occurring in treated wastewater. Batch sorption experiments using synthetic wastewater (SWW) and zeolite were performed. A 1:4 zeolite/SWW ratio was selected due to the high sorption capacity of the reactive material.The assays were carried out by triplicate. All the bottles containing the SWW-zeolite mixture were placed on a mechanical shaker during 24 hours at 140 rpm and 25 °C. Ammonium and phosphate, as main nutrients, and a group of PPCPs were selected as compounds to be tested during the experiments. Nutrients were analyzed by ion chromatography. For PPCPs determination, Solid Phase Extraction (SPE) was applied before their analysis by liquid chromatography-mass spectrometry time of flight (LC-MS/ TOF). The experimental data were fitted to linearized Langmuir and Freundlich isotherm equations to obtain sorption parameters. In general, Freundlich model shows a greater capability of reproducing experimental data. To our knowledge, sorption of the investigated compounds on zeolite has rarely been addressed and this holds true especially for PPCPs. Therefore, the obtained results will be useful for the design and characterization of those HPRBs in which zeolite will be employed to regenerate treated wastewater for artificial recharge activities.

  4. Use of Constructed Wetlands for Polishing Recharge Wastewater

    NASA Astrophysics Data System (ADS)

    Cardwell, W.

    2009-12-01

    The use of constructed wetlands for waste water treatment is becoming increasingly popular as more focus is being shifted to natural means of waste treatment. These wetlands employ processes that occur naturally and effectively remove pollutants and can greatly minimize costs when compared to full scale treatment plants. Currently, wetland design is based on basic “rules-of-thumb,” meaning engineers have a general understanding but not necessarily a thorough knowledge of the intricate physical, biological, and chemical processes involved in these systems. Furthermore, there is very little consideration given to use the wetland as a recharge pond to allow the treated water to percolate and recharge the local groundwater aquifers. The City of Foley, located in Alabama, and the Utilities Board of the City of Foley partnered with Wolf Bay Watershed Watch to evaluate alternative wastewater effluent disposal schemes. Rather than discharging the treated water into a local stream, a pilot program has been developed to allow water from the treatment process to flow into a constructed wetlands area where, after natural treatment, the treated water will then be allowed to percolate into a local unconfined aquifer. The goal of this study is to evaluate how constructed wetlands can be used for “polishing” effluent as well as how this treated water might be reused. Research has shown that constructed wetlands, with proper design and construction elements, are effective in the treatment of BOD, TSS, nitrogen, phosphorous, pathogens, metals, sulfates, organics, and other substances commonly found in wastewater. Mesocosms will be used to model the wetland, at a much smaller scale, in order to test and collect data about the wetland treatment capabilities. Specific objectives include: 1. Determine optimum flow rates for surface flow wetlands where water treatment is optimized. 2. Evaluate the capabilities of constructed wetlands to remove/reduce common over the counter pharmaceuticals such as acetaminophen (Tylenol) and ibuprofen. 3. Evaluate the use of different wetland plants and their treatment characteristics. 4. Evaluate the effectiveness of the wetlands to allow treated to water to recharge local into a local groundwater aquifer.

  5. Energy-constrained open-system magmatic processes IV: Geochemical, thermal and mass consequences of energy-constrained recharge, assimilation and fractional crystallization (EC-RAFC)

    SciTech Connect

    Wendy A. Bohrson Department of Geological Sciences, Central Washington University, Ellensburg, Washington, 98926, USA; Frank J. Spera Institute for Crustal Studies and Department of Geological Sciences, University of California, Santa Barbara, California, 93106, USA

    2003-07-01

    A wealth of geochemical and petrological data provide evidence that the processes of fractional crystallization, assimilation, and magma recharge (replenishment) dominate the chemical signatures of many terrestrial igneous rocks. Previous work [ Spera and Bohrson, 2001 ; Bohrson and Spera, 2001 ] has established the importance of integrating energy, species and mass conservation into simulations of complex magma chamber processes. An extended version of the energy-constrained formulation, Energy-Constrained Recharge, Assimilation, Fractional Crystallization (EC-RAFC), tracks mass and compositional variations of melt, cumulates, and enclaves in a magma body undergoing simultaneous recharge, assimilation, and fractional crystallization [ Spera and Bohrson, 2002 ]. Because many EC-RAFC results are distinct from those predicted by extant RAFC formulations, the primary goal of this paper is to present a range of geochemical and mass relationships for selected cases that highlight issues relevant to modern petrology. Among the plethora of petrologic problems that have important, well-documented analogues in nature are the geochemical distinctions that arise when a magma body undergoes continuous versus episodic recharge, the connection between erupted magmas and associated cumulate bodies, the behavior of recharge-fractionation dominated systems (RFC), thermodynamic conditions that promote the formation of enclaves versus cumulates, and the conditions under which magma bodies may be described as chemically homogeneous. Investigation of the effects of continuous versus episodic recharge for mafic magma undergoing RAFC in the lower crust indicates that the resulting geochemical trends for melt and solids are sensitive to the intensity and composition of recharge, suggesting that EC-RAFC may be used as a tool to distinguish the nature of the recharge events. Compared to the record preserved in melts, the geochemical and mass characteristics of solids associated with particular RAFC events may record a more complete view of the physiochemical history of an open-system magma body. The capability of EC-RAFC to track melts and solids creates a genetic link that can be compared to natural analogues such as layered mafic intrusions and flood basalts, or mafic enclaves and their intermediate-composition volcanic or plutonic hosts. The ability to quantify chemical and volume characteristics of solids and melts also underscores the need for integrated field, petrologic and geochemical studies of igneous systems. While it appears that a number of volcanic events or systems may be characterized by continuous influx or eruption of magma (“steady state systems”), reports describing compositional homogeneity for products that represent eruptions of more than one event are relatively rare. In support of this, EC-RAFC results indicate that very specific combinations of recharge conditions, bulk distribution coefficients, and element concentrations are required to achieve geochemical homogeneity during cooling of a magma body undergoing RAFC. In summary, critical points are that EC-RAFC provides a method to quantitatively investigate complex magmatic systems in a thermodynamic context; it predicts complex, nonmonotonic geochemical trends for which there are natural analogues that have been difficult to model; and finally, EC-RAFC establishes the link between the chemical and physical attributes of a magmatic system. Application of EC-RAFC promises to improve our understanding of specific tectonomagmatic systems as well as enhance our grasp of the essential physiochemical principles that govern magma body evolution.

  6. Using HDR (Hot Dry Rock) technology to recharge The Geysers

    SciTech Connect

    Brown, D.W.; Robinson, B.A.

    1990-01-01

    The main reason for the productivity decline at The Geysers geothermal field is obvious: more fluid is being withdrawn from the reservoir than is being returned by reinjection and natural recharge. However, there is another factor that may be contributing to this decline --- the method of reinjection. By reinjecting cold condensate directly into the steam dome as is the current practice, the very large pressure difference between the injected condensate and the underpressured reservoir guarantees that the reinjected fluid will fall rapidly to the bottom of the reservoir, with very little residence time for heat transfer. This point is very important since the vast majority of the heat contained in The Geysers geothermal field is stored in the hot rock comprising the reservoir. 10 refs., 4 figs.

  7. Biologically inspired pteridine redox centres for rechargeable batteries.

    PubMed

    Hong, Jihyun; Lee, Minah; Lee, Byungju; Seo, Dong-Hwa; Park, Chan Beum; Kang, Kisuk

    2014-01-01

    The use of biologically occurring redox centres holds a great potential in designing sustainable energy storage systems. Yet, to become practically feasible, it is critical to explore optimization strategies of biological redox compounds, along with in-depth studies regarding their underlying energy storage mechanisms. Here we report a molecular simplification strategy to tailor the redox unit of pteridine derivatives, which are essential components of ubiquitous electron transfer proteins in nature. We first apply pteridine systems of alloxazinic structure in lithium/sodium rechargeable batteries and unveil their reversible tautomerism during energy storage. Through the molecular tailoring, the pteridine electrodes can show outstanding performance, delivering 533?Wh?kg(-1) within 1?h and 348?Wh?kg(-1) within 1?min, as well as high cyclability retaining 96% of the initial capacity after 500 cycles at 10?A?g(-1). Our strategy combined with experimental and theoretical studies suggests guidance for the rational design of organic redox centres. PMID:25359101

  8. An implantable power supply with an optically rechargeable lithium battery.

    PubMed

    Goto, K; Nakagawa, T; Nakamura, O; Kawata, S

    2001-07-01

    A novel power supply for medical implants has been developed. A wireless near-infrared power transmission recharges a lithium secondary battery in the power supply. A photovoltaic cell array embedded under skin receives near-infrared light through the skin and charges the battery directly powering an implanted device. We have shown that, for a photodiode area of 2.1 cm2, 17 min of near-infrared irradiation at a 810-nm wavelength with a power density of 22 mW/cm2 can send enough energy to allow regular commercial cardiac pacemakers to run for 24 h. The temperature rise of the skin during the light irradiation was 1.4 degrees C. PMID:11442295

  9. Status of the development of rechargeable lithium cells

    NASA Technical Reports Server (NTRS)

    Halpert, G.; Surampudi, S.; Shen, D.; Huang, C-K.; Narayanan, S.; Vamos, E.; Perrone, D.

    1993-01-01

    The progress in the development of the ambient temperature lithium - titanium disulfide rechargeable cell under development at the Jet Propulsion Laboratory is described in this paper. Originally aimed at achieving a specific energy of 100 Wh/kg, 'AA' cells have demonstrated 125 Wh/kg at the C/3 discharge rate. The results of evaluating cell design parameters are discussed and cycling test data are also included in the paper. Safety tests results at various over-charge and over discharge conditions and rates proved to be uneventful. The test results of cell with built-in overcharge mechanism proved the concept was feasible. Replacing the lithium foil electrode with a Li(x)C resulted in a capacity at 1mA/cm(exp 2) of 200 mAh/gm and 235 mAh/gm at 0.167 mA.

  10. Using isotopes for design and monitoring of artificial recharge systems

    USGS Publications Warehouse

    Contributors: Hendriksson, N.; Kulongoski, J.T.; Massmann, G.; Newman, B.

    2013-01-01

    Over the past years, the IAEA has provided support to a number of Member States engaged in the implementation of hydrological projects dealing with the design and monitoring of artificial recharge ( A R ) systems, primarily situated in arid and semiarid regions. AR is defined as any engineered system designed to introduce water to, and store water in, underlying aquifers. Aquifer storage and recovery (ASR) is a specific type of AR used with the purpose of increasing groundwater resources. Different water management strategies have been tested under various geographical, hydrological and climatic regimes. However, the success of such schemes cannot easily be predicted, since many variables need to be taken into account in the early stages of every AR project.

  11. Identifying recharge from tropical cyclonic storms, Baja California Sur, Mexico.

    PubMed

    Eastoe, Christopher J; Hess, Greg; Mahieux, Susana

    2015-04-01

    Groundwater in the Todos Santos watershed in southern Baja California, and throughout the peninsula south of latitude 28°N, has values of (?18 O‰, ?D‰) ranging between (-8.3, -57) and (-10.9, -78). Such negative values are uncharacteristic of the site latitude near the sea level. Altitude effects do not explain the isotope data. Tropical depressions originating along the Pacific coast of North America yield rain with isotopic depletion; rain from these weather systems in southern Arizona commonly has ?18O values<-10‰ in comparison with amount-weighted mean summer and fall rain at -6‰. Isotope data indicate hurricane rain as the predominant source of recharge in southern Baja California, where named tropical depressions bring large rains (>50?mm) at least once every 2 to 3 years, and along the Pacific coast between Jalisco and Oaxaca. PMID:24635484

  12. A large-scale simulation model to assess karstic groundwater recharge over Europe and the Mediterranean

    NASA Astrophysics Data System (ADS)

    Hartmann, A.; Gleeson, T.; Rosolem, R.; Pianosi, F.; Wada, Y.; Wagener, T.

    2015-06-01

    Karst develops through the dissolution of carbonate rock and is a major source of groundwater contributing up to half of the total drinking water supply in some European countries. Previous approaches to model future water availability in Europe are either too-small scale or do not incorporate karst processes, i.e. preferential flow paths. This study presents the first simulations of groundwater recharge in all karst regions in Europe with a parsimonious karst hydrology model. A novel parameter confinement strategy combines a priori information with recharge-related observations (actual evapotranspiration and soil moisture) at locations across Europe while explicitly identifying uncertainty in the model parameters. Europe's karst regions are divided into four typical karst landscapes (humid, mountain, Mediterranean and desert) by cluster analysis and recharge is simulated from 2002 to 2012 for each karst landscape. Mean annual recharge ranges from negligible in deserts to > 1 m a-1 in humid regions. The majority of recharge rates range from 20 to 50% of precipitation and are sensitive to subannual climate variability. Simulation results are consistent with independent observations of mean annual recharge and significantly better than other global hydrology models that do not consider karst processes (PCR-GLOBWB, WaterGAP). Global hydrology models systematically under-estimate karst recharge implying that they over-estimate actual evapotranspiration and surface runoff. Karst water budgets and thus information to support management decisions regarding drinking water supply and flood risk are significantly improved by our model.

  13. A simulation model to assess groundwater recharge over Europe's karst regions

    NASA Astrophysics Data System (ADS)

    Hartmann, A.; Gleeson, T.; Rosolem, R.; Pianosi, F.; Wada, Y.; Wagener, T.

    2014-11-01

    Karst develops through the dissolution of carbonate rock and is a major source of groundwater contributing up to half of the total drinking water supply in some European countries. Previous approaches to model future water availability in Europe are either too-small scale or do not incorporate karst processes, i.e. preferential flow paths. This study presents the first simulations of groundwater recharge in all karst regions in Europe with a parsimonious karst hydrology model. A novel parameter confinement strategy combines a priori information with recharge-related observations (actual evapotranspiration and soil moisture) at locations across Europe while explicitly identifying uncertainty in the model parameters. Europe's karst regions are divided into 4 typical karst landscapes (humid, mountain, Mediterranean and desert) by cluster analysis and recharge is simulated from 2002 to 2012 for each karst landscape. Mean annual recharge ranges from negligible in deserts to > 1 m a-1 in humid regions. The majority of recharge rates ranges from 20-50% of precipitation and are sensitive to sub-annual climate variability. Simulation results are consistent with independent observations of mean annual recharge and significantly better than other global hydrology models that do not consider karst processes (PCR-GLOBWB, WaterGAP). Global hydrology models systematically underestimate karst recharge implying that they over-estimate actual evapotranspiration and surface runoff. Karst water budgets and thus information to support management decisions regarding drinking water supply and flood risk are significantly improved by our model.

  14. Mechanisms of subglacial groundwater recharge as derived from noble gas, 14C, and stable isotopic data

    NASA Astrophysics Data System (ADS)

    Grundl, Tim; Magnusson, Nathan; Brennwald, Matthias S.; Kipfer, Rolf

    2013-05-01

    Noble gas, stable isotope and 14C data from samples collected along groundwater flow path within a confined Paleozoic aquifer in northeastern Wisconsin, USA are used to deduce the effect of the Laurentide Ice Sheet (LIS) on the underlying groundwater and its recharge dynamics. During the last glacial maximum the investigated area was near the center of the Green Bay Lobe of the LIS. 14C ages that extend to 26 k.a. and low ?18O derived temperatures during the time that the LIS was present indicate that aquifer recharge continued when ice covered the area. ?18O values as low as -17.5‰ and ?2H values as low as -127.7‰ indicate that a significant portion of aquifer recharge was derived from glacial meltwater that maintained its glacial isotopic signature during melting and subsequent recharge. Noble gas temperatures that remain above freezing at a constant ~3 °C, unusually high excess air (?Ne) values and noble gas fractionation patterns indicate that recharge occurred across a very dynamic water table located within the ice sheet. This englacial hydrologic system experienced recharge heads of as much as 7.8 m. Evidence for direct recharge of basal meltwater into the aquifer is not seen. To the authors' knowledge this is the first time that noble gas and isotope tracers have been used to deduce the provenance of aquifer water beneath continental ice sheets.

  15. Artificial recharge experiments on the Ship Creek alluvial fan, Anchorage, Alaska

    USGS Publications Warehouse

    Anderson, Gary S.

    1977-01-01

    During the summers of 1973 and 174, water from Ship Creek, Alaska, was diverted at an average rate of approximately 6 cfs (cubic feet per second) to an 11-acre recharge basin. Maximum sustained unit recharge for the basin was approximately 1.4 feet per day. During 1975 a second basin of 8 acres was also used for recharge, and the total diversion rate was increased to as much as 30 cfs. The second basin was never completely filled, but the unit recharge rate was at least four times as great as that in the first basin. During 1973 and 1974, when only one recharge basin was in operation, a maximum rise of 18 feet was observed in the ground-water table near the basin. In 1975, when both basins were being used, the maximum rise was 30 feet in the same area. During 1973 and 1974, the water-level rise was 12 and 8 feet in the unconfined and confined systems, respectively, at a point 4,400 feet downgradient from the basins; in 1975 the rise at the same point was 31 and 16 feet, respectively. The potentiometric rise that was achieved in the confined aquifer during summer operation of the recharge basins was quickly dissipated when diversion stopped and the basins drained. Thus the benefits of recharge would not persist into late winter, the critical period for water availability in Anchorage, unless diversion to the basins could be continued until January or February. (Woodard-USGS)

  16. Responses of groundwater recharge to land-cover changes and climate variability

    NASA Astrophysics Data System (ADS)

    Guan, Huade; Xu, Xiang; Ding, Zhenyu; Deng, Zijuan; Simmons, Craig; Hutson, John; Love, Andy; Ajami, Hoori

    2014-05-01

    It is estimated that groundwater directly provides drinking water for 1.5 billion people in the world. Anthropogenic activities during the past 200 years have led to the conversion of large areas of natural forest and grassland to cropland and pasture. Understanding and quantification of changes in groundwater recharge after surface vegetation alteration are important not only for water resource management, but also for land-use and land-cover management. On the other hand, groundwater recharge also responds to climate variability and changes. In this paper, we discuss two groundwater recharge estimation methods of different temporal resolution: chloride mass balance (CMB), and storage-discharge relationship (S-Q). Application of the CMB method over areas of historical forest clearance, or recent plantation, suffers from two difficulties: pre-clearance (or pre-plantation) recharge may have been contaminated by recharge that occurred after forest clearance (or plantation); and the post-clearance (or post-plantation) recharge may not yet have reached new chloride equilibrium. In coastal areas, strong spatial variability in chloride deposition leads to an additional difficulty in appropriately applying the CMB method. This presentation will discuss some recent development to address these difficulties. Meanwhile, an improved conceptual framework of the S-Q method for estimating seasonal and inter-annual variability of groundwater recharge is presented as well. Both are shown with case studies based at the Mount Lofty Ranges of South Australia.

  17. Groundwater Recharge in Juniper Woodlands: Insights from Long-Term Monitoring of Cave Drip Rates

    NASA Astrophysics Data System (ADS)

    Wilcox, B. P.; Sun, Z.; Munster, C.; Owens, K.

    2011-12-01

    The Edwards Plateau in Central Texas covers some 230,000 square kilometers. It is underlain by limestone and dolomite, and these karst parent materials give the region its distinct hydrologic character. Although the climate is semiarid, springs are abundant and support many perennial rivers. In particular, the Edwards Plateau is the source area for the prolific and regionally important Edwards Aquifer, the main water source for much of central Texas. Compared with other semiarid regions, the Edwards Plateau has abundant water resources; but an expanding population is now taxing those resources, and ways are being sought to increase groundwater recharge. Over the past 150 years, the expansion of juniper and oak have turned the Plateau into a shrub-dominated semiarid rangeland-a legacy of the historical overgrazing that took place from around 1880 to 1950. Many believe that reducing this woodland cover would lead to higher groundwater recharge. We undertook our study to try to understand the influence of juniper on groundwater recharge. For six years, we monitored drip rates in caves underlying juniper forests (these rates are surrogate measurements for groundwater recharge). After four years of monitoring, we removed the juniper from the study site and continued monitoring. Surprisingly, our results indicate that removing the trees had a negative effect on recharge. Several mechanisms may contribute to the reduction in recharge: for example, surface runoff increased following removal of the trees; and it is possible that the trees assist recharge by funneling water to their roots, hastening its movement through the substrate.

  18. Moisture content and recharge estimates at the Yakima Barricade borehole

    SciTech Connect

    Murphy, E.M.; Szescody, J.E.; Phillips, S.J.

    1991-12-01

    The DOE Deep Microbiology Program recently drilled a borehole near the Yakima Barricade, west of the 200 Areas. The area is vegetated by mature sagebrush. The borehole was drilled by cable tool and approximately every 1.5 m, sediment samples were collected in a bucket by the drill site geologist. Sediment samples for moisture content were sealed quickly Samples of opportunity'' were collected for the HSPA program (Hanford Site Performance Assessment), Isotope Recharge task. It should be noted that, although many QA Level II procedures were incorporated into the dulling and sampling, the Deep Microbiology Program is officially designated QA Level III, and therefore, the recharge values that we report here should only be usedfor planning purposes. A series of graphs illustrate the moisture content and chloride profiles in the Hanford Forrmtion at the Yakima Barricade Borehole. The gravimetric moisture content generally ranges between 0.01 and 0.08 in the first 70 m of sediment (only the first 30 m are shown in the figure), values that are typically found at the Hanford Site. The stratigraphy of this borehole is also attached. The first 1.5 m of the soil profile is Warden silt loam (designated eolian), followed by over 50 m of Hanford Formation. The Hanford Formation is composed of unconsolidated sands, silts, and gravels that were carried into the area by glacial flood waters during the close of the last Ice Age. Below the Hanford Formation is the Ringold Formation composed of semiconsolidated sediments. The water table is located at a depth of approximately 100 m.

  19. Moisture content and recharge estimates at the Yakima Barricade borehole

    SciTech Connect

    Murphy, E.M.; Szescody, J.E.; Phillips, S.J.

    1991-12-01

    The DOE Deep Microbiology Program recently drilled a borehole near the Yakima Barricade, west of the 200 Areas. The area is vegetated by mature sagebrush. The borehole was drilled by cable tool and approximately every 1.5 m, sediment samples were collected in a bucket by the drill site geologist. Sediment samples for moisture content were sealed quickly ``Samples of opportunity`` were collected for the HSPA program (Hanford Site Performance Assessment), Isotope Recharge task. It should be noted that, although many QA Level II procedures were incorporated into the dulling and sampling, the Deep Microbiology Program is officially designated QA Level III, and therefore, the recharge values that we report here should only be usedfor planning purposes. A series of graphs illustrate the moisture content and chloride profiles in the Hanford Forrmtion at the Yakima Barricade Borehole. The gravimetric moisture content generally ranges between 0.01 and 0.08 in the first 70 m of sediment (only the first 30 m are shown in the figure), values that are typically found at the Hanford Site. The stratigraphy of this borehole is also attached. The first 1.5 m of the soil profile is Warden silt loam (designated eolian), followed by over 50 m of Hanford Formation. The Hanford Formation is composed of unconsolidated sands, silts, and gravels that were carried into the area by glacial flood waters during the close of the last Ice Age. Below the Hanford Formation is the Ringold Formation composed of semiconsolidated sediments. The water table is located at a depth of approximately 100 m.

  20. Rapid Recharge to Perched-Intermediate Groundwater Zones, Pajarito Plateau, Los Alamos, New Mexico

    NASA Astrophysics Data System (ADS)

    Reid, K. D.; Koch, R. J.; Katzman, D.; Birdsell, K. H.; Broxton, D. E.; Vesselinov, V. V.

    2008-12-01

    The Los Alamos National Laboratory continuously monitors groundwater levels and surface-water discharge at over 150 locations on the Pajarito Plateau. The resulting data sets were analyzed to help identify locations where surface water and shallow alluvial groundwater (generally <30 ft) recharge deeper perched- intermediate groundwater (approximately 200 to 700 ft bgs) zones. Runoff from snowmelt and summer rainstorms recharges the shallow alluvial groundwater. The vadose zone beneath the alluvial groundwater ranges in thickness from 600 to 1200 ft. Typical estimated annual infiltration rates vary spatially from <1mm/yr to 1000 mm/yr. However, localized rapid recharge can sometimes yield transient infiltration events that are detected 200 ft below ground surface within a few days. The recharge events are identified by the observed water-level fluctuations in perched-intermediate groundwater monitoring wells. Preliminary analysis of the data suggests that the mechanism for this rapid recharge is spatially-limited fracture flow through basalt and welded volcanic tuff. The rapid recharge has been observed at three separate areas in response to both snowmelt and stormwater runoff events. One recharge area located on the west side of the plateau is associated with a densely-welded, fractured, volcanic tuff that is also possibly faulted. Surface runoff and alluvial groundwater in drainages presumably infiltrates faulted and fractured tuffs, recharging perched- intermediate groundwater at depths of 600 to 700 ft. Two other areas of rapid infiltration occur on the eastern side of the plateau where thin nonwelded tuff and/or thin alluvium in canyon bottoms overlie highly fractured basalt. In these areas surface water and alluvial groundwater easily gain access to the shallow basalt beneath the canyon floor. Infiltration then takes place along fractures and recharges perched-intermediate groundwater within deeper basalt units. Identifying these areas is important for establishing an effective groundwater monitoring network and for refining conceptual models of infiltration mechanisms and contaminant pathways.

  1. Artificial groundwater recharge zones mapping using remote sensing and GIS: a case study in Indian Punjab.

    PubMed

    Singh, Amanpreet; Panda, S N; Kumar, K S; Sharma, Chandra Shekhar

    2013-07-01

    Artificial groundwater recharge plays a vital role in sustainable management of groundwater resources. The present study was carried out to identify the artificial groundwater recharge zones in Bist Doab basin of Indian Punjab using remote sensing and geographical information system (GIS) for augmenting groundwater resources. The study area has been facing severe water scarcity due to intensive agriculture for the past few years. The thematic layers considered in the present study are: geomorphology (2004), geology (2004), land use/land cover (2008), drainage density, slope, soil texture (2000), aquifer transmissivity, and specific yield. Different themes and related features were assigned proper weights based on their relative contribution to groundwater recharge. Normalized weights were computed using the Saaty's analytic hierarchy process. Thematic layers were integrated in ArcGIS for delineation of artificial groundwater recharge zones. The recharge map thus obtained was divided into four zones (poor, moderate, good, and very good) based on their influence to groundwater recharge. Results indicate that 15, 18, 37, and 30 % of the study area falls under "poor," "moderate," "good," and "very good" groundwater recharge zones, respectively. The highest recharge potential area is located towards western and parts of middle region because of high infiltration rates caused due to the distribution of flood plains, alluvial plain, and agricultural land. The least effective recharge potential is in the eastern and middle parts of the study area due to low infiltration rate. The results of the study can be used to formulate an efficient groundwater management plan for sustainable utilization of limited groundwater resources. PMID:23775493

  2. Multi-scale experimental programs for estimating groundwater recharge in hydrologically changing basins

    NASA Astrophysics Data System (ADS)

    McIntyre, Neil; Larsen, Josh; Reading, Lucy; Bulovic, Nevenka; Jarihani, Abdollah; Finch, Warren

    2015-04-01

    Groundwater recharge estimates are required to evaluate sustainable groundwater abstractions and to support groundwater impacts assessments associated with minerals and energy extraction. Increasingly, recharge estimates are also needed for regional and global scale water cycle modelling. This is especially the case in the great arid and semi-arid basins of the world due to increased water scarcity and dependence of ecosystems and livelihoods on their water supplies, and the considerable potential influence of groundwater on the hydrological cycle. Groundwater resources in the semi-arid Surat Basin of south-east Queensland, Australia, support extensive groundwater-dependent ecosystems and have historically been utilised for regional agriculture and urban water-use. Large volumes of water are currently being produced and will continue to do so as a part of coal seam gas extraction. There is considerable uncertainty about the impacts of gas extraction on water resources and the hydrological cycle, and much of this uncertainty stems from our limited knowledge about recharge processes and how to upscale them. Particular questions are about the role of storm events in controlling annual recharge, the relative contributions of local 'recharge zones' versus diffuse recharge and the translation of (relatively easily quantified) shallow drainage estimates to groundwater recharge. A multi-scale recharge research program is addressing these questions, using multiple approaches in estimating groundwater recharge, including plot and catchment scale monitoring, use of remote sensed data and simulation models. Results during the first year of the program have resulted in development of process hypotheses and experimental designs at three field sites representing key gaps in knowledge. The presentation will overview the process of designing the experimental program; how the results from these sites will be integrated with existing knowledge; and how results will be used to advance our knowledge of the changing hydrological cycle in the Surat Basin.

  3. Ground-Water Recharge in the Arid and Semiarid Southwestern United States - Climatic and Geologic Framework

    USGS Publications Warehouse

    Stonestrom, David A.; Harrill, James R.

    2007-01-01

    Ground-water recharge in the arid and semiarid southwestern United States results from the complex interplay of climate, geology, and vegetation across widely ranging spatial and temporal scales. Present-day recharge tends to be narrowly focused in time and space. Widespread water-table declines accompanied agricultural development during the twentieth century, demonstrating that sustainable ground-water supplies are not guaranteed when part of the extracted resource represents paleorecharge. Climatic controls on ground-water recharge range from seasonal cycles of summer monsoonal and winter frontal storms to multimillennial cycles of glacial and interglacial periods. Precipitation patterns reflect global-scale interactions among the oceans, atmosphere, and continents. Large-scale climatic influences associated with El Ni?o and Pacific Decadal Oscillations strongly but irregularly control weather in the study area, so that year-to-year variations in precipitation and ground-water recharge are large and difficult to predict. Proxy data indicate geologically recent periods of multidecadal droughts unlike any in the modern instrumental record. Anthropogenically induced climate change likely will reduce ground-water recharge through diminished snowpack at higher elevations, and perhaps through increased drought. Future changes in El Ni?o and monsoonal patterns, both crucial to precipitation in the study area, are highly uncertain in current models. Land-use modifications influence ground-water recharge directly through vegetation, irrigation, and impermeable area, and indirectly through climate change. High ranges bounding the study area?the San Bernadino Mountains and Sierra Nevada to the west, and the Wasatch and southern Colorado Rocky Mountains to the east?provide external geologic controls on ground-water recharge. Internal geologic controls stem from tectonic processes that led to numerous, variably connected alluvial-filled basins, exposure of extensive Paleozoic aquifers in mountainous recharge areas, and distinct modes of recharge in the Colorado Plateau and Basin and Range subregions.

  4. Silt and gas accumulation beneath an artificial recharge spreading basin, Southwestern Utah, U.S.A.

    USGS Publications Warehouse

    Heilweil, V.M.; Solomon, D.K.; Ortiz, G.

    2009-01-01

    Sand Hollow Reservoir in southwestern Utah, USA, is operated for both surface-water storage and artificial recharge to the underlying Navajo Sandstone. The total volume of estimated artificial recharge between 2002 and 2007 is 85 million cubic meters (69,000 acre-feet). Since 2002, artificial recharge rates have generally been declining and are inversely correlated with the increasing surface area of the reservoir. Permeability testing of core samples retrieved from beneath the reservoir indicates that this decline may not be due to silt accumulation. Artificial recharge rates also show much seasonal variability. Calculations of apparent intrinsic permeability show that these variations can only partly be explained by variation in water viscosity associated with seasonal changes in water temperature. Sporadic seasonal trends in recharge rates and intrinsic permeability during 2002-2004 could be associated with the large fluctuations in reservoir elevation and wetted area. From 2005 through 2007, the reservoir was mostly full and there has been a more consistent seasonal pattern of minimum recharge rates during the summer and maximum rates during the autumn. Total dissolved-gas pressure measurements indicate the presence of biogenic gas bubbles in the shallow sediments beneath the shallower parts of Sand Hollow Reservoir when the water is warmer. Permeability reduction associated with this gas clogging may contribute to the decrease in artificial recharge rates during the spring and summer, with a subsequently increasing recharge rates in the autumn associated with a decline in volume of gas bubbles. Other possible causes for seasonal variation in artificial recharge rates require further investigation.

  5. Partitioning sources of recharge in environments with groundwater recirculation using carbon-14 and CFC-12

    NASA Astrophysics Data System (ADS)

    Bourke, Sarah A.; Cook, Peter G.; Dogramaci, Shawan; Kipfer, Rolf

    2015-06-01

    Groundwater recirculation occurs when groundwater is pumped from an aquifer onto the land surface, and a portion of that water subsequently infiltrates back to the aquifer. In environments where groundwater is recirculated, differentiation between various sources of recharge (e.g. natural rainfall recharge vs. recirculated water) can be difficult. Groundwater age indicators, in particular transient trace gases, are likely to be more sensitive tracers of recharge than stable isotopes or chloride in this setting. This is because, unlike stable isotopes or chloride, they undergo a process of equilibration with the atmosphere, and historical atmospheric concentrations are known. In this paper, groundwater age indicators (14C and CFC-12) were used as tracers of recharge by surplus mine water that is discharged to streams. Ternary mixing ratios were calculated based on 14C and CFC-12 concentrations measured along three transects of piezometers and monitoring wells perpendicular to the creeks, and from dewatering wells. Uncertainty in calculated mixing ratios was estimated using a Monte Carlo approach. Ternary mixing ratios in dewatering wells suggest that recharge by mine water accounted for between 10% and 87% of water currently abstracted by dewatering wells. The calculated mixing ratios suggest that recharge by mine water extends to a distance of more than 550 m from the creeks. These results are supported by seepage flux estimates based on the water and chloride balance along the creeks, which suggest that 85-90% of mine water discharged to the creeks recharges the aquifer and recharge by mine water extends between 110 and 730 m from the creeks. Mixing calculations based on gaseous groundwater age indicators could also be used to partition recharge associated with agricultural irrigation or artificial wetland supplementation.

  6. Comparison of different estimation techniques to quantify groundwater recharge in Pirna, Germany

    NASA Astrophysics Data System (ADS)

    Ringleb, Jana; Sallwey, Jana; Stefan, Catalin

    2015-04-01

    Water scarcity in combination with groundwater exploitation is a major concern worldwide because of climate change, population growth and rising water demand. To be able to sustainably manage and protect groundwater resources, it is necessary to quantify the amount of water which leaks through the unsaturated zone and recharges the aquifer naturally. However, quantifying the spatial and temporal distribution of recharge is difficult because of soil heterogeneity and the influence of vegetation. For that reason and because field measurements of recharge are difficult to obtain, models are valuable tools to quantify recharge. Numerical models need a lot of parameters which are hard to measure and hence can only be estimated. Therefore analytical models or empirical equations which use less and / or easier obtainable parameters could estimate groundwater recharge as well as numerical models because of the underlying uncertainty in parameter estimation. Recharge estimation methods which use different model approaches and have varying complexity were compared at Pirna test field site, Germany to select suitable methods which will later be integrated into a web-based Decision Support System (DSS) developed for the sustainable management of groundwater. The complexity of the used methods covers numerical models, analytical models as well as empirical equations. Different model approaches were used to estimate groundwater recharge including amongst others a groundwater flow model, an unsaturated zone model and a watershed model. The resulting groundwater recharge estimates received from the numerical and analytical models and from empirical equations were compared to evaluate whether the methods are suitable to estimate groundwater recharge considering the complexity, data requirements and time-consumption of each method.

  7. Effects of urban storm-runoff control on ground-water recharge in Nassau County, New York

    USGS Publications Warehouse

    Ku, Henry; Hagelin, Nathan; Buxton, Herbert

    1992-01-01

    Before urban development, most ground-water recharge on Long Island, New York, occurred during the dormant season, when evapotranspiration is low. The use of recharge basins for collection and disposal of urban storm runoff in Nassau County has enabled ground-water recharge to occur also during the growing season. In contrast, the use of storm sewers to route storm runoff to streams and coastal waters has resulted in a decrease in ground-water recharge during the dormant season. The net result of these two forms of urban storm-runoff control has been an increase in annual recharge of about 12 percent in areas served by recharge basins and a decrease of about 10 percent in areas where storm runoff is routed to streams and tidewater. On a countywide basis, annual ground-water recharge has remained nearly the same as under predevelopment conditions, but its distribution pattern has changed. Redistribution resulted in increased recharge in the eastern and central parts of the county, and decreased recharge in the western and nearshore areas. Model simulation of recharge indicates that the water-table altitude has increased by as much as 5 ft above predevelopment levels in areas served by recharge basins and declined by as much as 3 feet in areas where stormwater is discharged to streams and tidewater.

  8. Evaluation of recharge to the Skunk Creek Aquifer from a constructed wetland near Lyons, South Dakota

    USGS Publications Warehouse

    Thompson, Ryan F.

    2002-01-01

    A wetland was constructed in the Skunk Creek flood plain near Lyons in southeast South Dakota to mitigate for wetland areas that were filled during construction of a municipal golf course for the city of Sioux Falls. A water-rights permit was obtained to allow the city to pump water from Skunk Creek into the wetland during times when the wetland would be dry. The amount of water seeping through the wetland and recharging the underlying Skunk Creek aquifer was not known. The U.S. Geological Survey, in cooperation with the city of Sioux Falls, conducted a study during 1997-2000 to evaluate recharge to the Skunk Creek aquifer from the constructed wetland. Three methods were used to estimate recharge from the wetland to the aquifer: (1) analysis of the rate of water-level decline during periods of no inflow; (2) flow-net analysis; and (3) analysis of the hydrologic budget. The hydrologic budget also was used to evaluate the efficiency of recharge from the wetland to the aquifer. Recharge rates estimated by analysis of shut-off events ranged from 0.21 to 0.82 foot per day, but these estimates may be influenced by possible errors in volume calculations. Recharge rates determined by flow-net analysis were calculated using selected values of hydraulic conductivity and ranged from 566,000 gallons per day using a hydraulic conductivity of 0.5 foot per day to 1,684,000 gallons per day using a hydraulic conductivity of 1.0 foot per day. Recharge rates from the hydrologic budget varied from 0.74 to 0.85 foot per day, and averaged 0.79 foot per day. The amount of water lost to evapotranspiration at the study wetland is very small compared to the amount of water seeping from the wetland into the aquifer. Based on the hydrologic budget, the average recharge efficiency was estimated as 97.9 percent, which indicates that recharging the Skunk Creek aquifer by pumping water into the study wetland is highly efficient. Because the Skunk Creek aquifer is composed of sand and gravel, the 'recharge mound' is less distinct than might be found in an aquifer composed of finer materials. However, water levels recorded from piezometers in and around the wetland do show a higher water table than periods when the wetland was dry. The largest increases in water level occur between the wetland channel and Skunk Creek. The results of this study demonstrate that artificially recharged wetlands can be useful in recharging underlying aquifers and increasing water levels in these aquifers.

  9. Delineation of recharge rate from a hybrid water table fluctuation method

    NASA Astrophysics Data System (ADS)

    Park, Eungyu

    2012-07-01

    The concept of the hybrid water table fluctuation (WTF) method for recharge rate estimation was revisited. To estimate the recharge rate, a physically based WTF equation was established. The concept of transient fillable porosity was proposed and computed with unsaturated hydraulics models. The developed model is tested by applying to the water table fluctuation data from Hongcheon, Korea. In the applications, the recharge and fillable porosity estimates were found to be most sensitive to nonlinearity in the unsaturated water content profile and permeability. Also, the water table level drift, which does not originate from precipitation, serves as a major source of estimation error.

  10. Statistical analysis of hydrographs and water-table fluctuation to estimate groundwater recharge

    NASA Astrophysics Data System (ADS)

    Moon, Sang-Ki; Woo, Nam C.; Lee, Kwang S.

    2004-06-01

    Using water-table monitoring data from the National Groundwater Monitoring Network in Korea, groundwater hydrographs were classified into five typical groups. Then, to estimate groundwater recharge, a modified water-table fluctuation (WTF) method was developed from the relation between the cumulative WTF and corresponding precipitation records. Applying this method to different types of hydrographs, the spatial variability of recharge in river basins was evaluated. Each estimated recharge can be considered the maximum value, and therefore, could be used as a cut-off guideline (an upper limit) for groundwater development in river basins.

  11. Quantifying Ground-Water Recharge Using a Coupled Water-Heat-Solute Transport Model: Optimal Nonlinear Parameter Estimation, Nonuniqueness, and Predictive Uncertainty

    NASA Astrophysics Data System (ADS)

    Friedel, M. J.

    2002-12-01

    In arid and semi-arid regions of the United States, rapid population growth continues to increase the demand for already diminishing ground-water supplies. For this reason, hydrologists are interested in accurately estimating ground-water recharge; however, ephemeral streamflow in these regions renders ground-water recharge estimation using hydrograph separation techniques ineffective. One alternate approach is to use a coupled variably saturated ground-water transport model; however, the success of a ground-water transport model is largely dependent on knowledge of model parameters, and most model parameters are generally unknown. In this study, application of a nonlinear parameter estimation algorithm (PEST) to a coupled water-heat-solute transport model (VST2D) is evaluated for its ability to simultaneously estimate water, heat, and solute transport parameters using a measurement objective function comprised of different dependent variable combinations: pressure-temperature-concentration (PTC), pressure-concentration (PC), pressure-temperature (PT), and temperature-concentration (TC). Evaluating the effectiveness of different dependent variable combinations to facilitate parameter estimation is possible using subsurface pressure, temperature, and concentration measurements derived in response to a hypothetical model of artificial recharge. In general, application of nonlinear regression successfully estimated heterogeneous parameter sets for the PTC, PC, and PT models, however, several PT model parameters were removed to maintain a well-posed inverse problem. The issue of ill-posedness with the PT and TC models is overcome following the introduction of a second objective function that regularized parameters. Whereas the nonlinear parameter estimation process consistently located the global minimum, recalibration using preferred system parameter sets and regularization functionality revealed the presence of parameter nonuniqueness. Using a constrained Monte Carlo calibration and likelihood approach, the effect of PTC model parameter nonuniqueness on cumulative ground-water recharge prediction after 14 days suggests a range of likely values that vary by a factor of more than two.

  12. Highly Conductive Solvent-Free Polymer Electrolytes for Lithium Rechargeable Batteries

    SciTech Connect

    Robert Filler, Zhong Shi and Braja Mandal

    2004-10-21

    In order to obviate the deficiencies of currently used electrolytes in lithium rechargeable batteries, there is a compelling need for the development of solvent-free, highly conducting solid polymer electrolytes (SPEs). The problem will be addressed by synthesizing a new class of block copolymers and plasticizers, which will be used in the formulation of highly conducting electrolytes for lithium-ion batteries. The main objective of this Phase-I effort is to determine the efficacy and commercial prospects of new specifically designed SPEs for use in electric and hybrid electric vehicle (EV/HEV) batteries. This goal will be achieved by preparing the SPEs on a small scale with thorough analyses of their physical, chemical, thermal, mechanical and electrochemical properties. SPEs will play a key role in the formulation of next generation lithium-ion batteries and will have a major impact on the future development of EVs/HEVs and a broad range of consumer products, e.g., computers, camcorders, cell phones, cameras, and power tools.

  13. Ground-water pumpage and artificial recharge estimates for calendar year 2000 and average annual natural recharge and interbasin flow by hydrographic area, Nevada

    USGS Publications Warehouse

    Lopes, Thomas J.; Evetts, David M.

    2004-01-01

    Nevada's reliance on ground-water resources has increased because of increased development and surface-water resources being fully appropriated. The need to accurately quantify Nevada's water resources and water use is more critical than ever to meet future demands. Estimated ground-water pumpage, artificial and natural recharge, and interbasin flow can be used to help evaluate stresses on aquifer systems. In this report, estimates of ground-water pumpage and artificial recharge during calendar year 2000 were made using data from a variety of sources, such as reported estimates and estimates made using Landsat satellite imagery. Average annual natural recharge and interbasin flow were compiled from published reports. An estimated 1,427,100 acre-feet of ground water was pumped in Nevada during calendar year 2000. This total was calculated by summing six categories of ground-water pumpage, based on water use. Total artificial recharge during 2000 was about 145,970 acre-feet. At least one estimate of natural recharge was available for 209 of the 232 hydrographic areas (HAs). Natural recharge for the 209 HAs ranges from 1,793,420 to 2,583,150 acre-feet. Estimates of interbasin flow were available for 151 HAs. The categories and their percentage of the total ground-water pumpage are irrigation and stock watering (47 percent), mining (26 percent), water systems (14 percent), geothermal production (8 percent), self-supplied domestic (4 percent), and miscellaneous (less than 1 percent). Pumpage in the top 10 HAs accounted for about 49 percent of the total ground-water pumpage. The most ground-water pumpage in an HA was due to mining in Pumpernickel Valley (HA 65), Boulder Flat (HA 61), and Lower Reese River Valley (HA 59). Pumpage by water systems in Las Vegas Valley (HA 212) and Truckee Meadows (HA 87) were the fourth and fifth highest pumpage in 2000, respectively. Irrigation and stock watering pumpage accounted for most ground-water withdrawals in the HAs with the sixth through ninth highest pumpage. Geothermal production accounted for most pumpage in the Carson Desert (HA 101). Reinjection of ground water pumped for geothermal energy production accounted for about 64 percent (93,310 acre-feet) of the total artificial recharge. The only artificial recharge by water systems was in Las Vegas Valley, where 29,790 acre-feet of water from the Colorado River was injected into the aquifer system. Artificial recharge by mining totaled 22,870 acre-feet. Net ground-water flow was estimated only for the 143 HAs with available estimates of both natural recharge and interbasin flow. Of the 143 estimates, 58 have negative net ground-water flow, indicating that ground-water storage could be depleted if pumpage continues at the same rate. The State has designated HAs where permitted ground-water rights approach or exceed the estimated average annual recharge. Ten HAs were identified that are not designated and have a net ground-water flow between -1,000 to -35,000 acre-feet. Due to uncertainties in recharge, the water budgets for these HAs may need refining to determine if ground-water storage is being depleted.

  14. Hydrologic and hydraulic assessment of artificial recharge in the Sparta Aquifer of Union County, Arkansas

    E-print Network

    Sowby, Robert B

    2013-01-01

    Groundwater pumping from the Sparta aquifer in Union County, Arkansas, has long exceeded natural recharge, threatening the regional water supply. An alternative water-supply project, completed in 2004, now provides treated ...

  15. Recharge Data Package for the 2005 Integrated Disposal Facility Performance Assessment

    SciTech Connect

    Fayer, Michael J.; Szecsody, Jim E.

    2004-06-30

    Pacific Northwest National Laboratory assisted CH2M Hill Hanford Group, Inc., (CHG) by providing estimates of recharge rates for current conditions and long-term scenarios involving disposal in the Integrated Disposal Facility (IDF). The IDF will be located in the 200 East Area at the Hanford Site and will receive several types of waste including immobilized low-activity waste. The recharge estimates for each scenario were derived from lysimeter and tracer data collected by the IDF PA Project and from modeling studies conducted for the project. Recharge estimates were provided for three specific site features (the surface barrier; possible barrier side slopes; and the surrounding soil) and four specific time periods (pre-Hanford; Hanford operations; surface barrier design life; post-barrier design life). CHG plans to conduct a performance assessment of the latest IDF design and call it the IDF 2005 PA; this recharge data package supports the upcoming IDF 2005 PA.

  16. Ground-Water Recharge in the Arid and Semiarid Southwestern United States

    USGS Publications Warehouse

    Stonestrom, David A.; Constantz, Jim; Ferre, Ty P.A.; Leake, Stanley A.

    2007-01-01

    Ground-water recharge in the arid and semiarid southwestern United States results from the complex interplay of climate, geology, and vegetation across widely ranging spatial and temporal scales. Present-day recharge tends to be narrowly focused in time and space. Widespread water-table declines accompanied agricultural development during the twentieth century, demonstrating that sustainable ground-water supplies are not guaranteed when part of the extracted resource represents paleorecharge. Climatic controls on ground-water recharge range from seasonal cycles of summer monsoonal and winter frontal storms to multimillennial cycles of glacial and interglacial periods. Precipitation patterns reflect global-scale interactions among the oceans, atmosphere, and continents. Large-scale climatic influences associated with El Ni?o and Pacific Decadal Oscillations strongly, but irregularly, control weather in the study area, so that year-to-year variations in precipitation and ground-water recharge are large and difficult to predict. Proxy data indicate geologically recent periods of naturally occurring multidecadal droughts unlike any in the modern instrumental record. Any anthropogenically induced climate change will likely reduce ground-water recharge through diminished snowpack at higher elevations. Future changes in El Ni?o and monsoonal patterns, both crucial to precipitation in the study area, are highly uncertain in current models. Current land-use modifications influence ground-water recharge through vegetation, irrigation, and impermeable area. High mountain ranges bounding the study area?the San Bernadino Mountains and Sierra Nevada to the west, and the Wasatch and southern Colorado Rocky Mountains to the east?provide external geologic controls on ground-water recharge. Internal geologic controls stem from tectonic processes that led to numerous, variably connected alluvial-filled basins, exposure of extensive Paleozoic aquifers in mountainous recharge areas, and distinct modes of recharge in the Colorado Plateau and Basin and Range subregions. The chapters in this professional paper present (first) an overview of climatic and hydrogeologic framework (chapter A), followed by a regional analysis of ground-water recharge across the entire study area (chapter B). These are followed by an overview of site-specific case studies representing different subareas of the geographically diverse arid and semiarid southwestern United States (chapter C); the case studies themselves follow in chapters D?K. The regional analysis includes detailed hydrologic modeling within the framework of a high-resolution geographic-information system (GIS). Results from the regional analysis are used to explore both the distribution of ground-water recharge for mean climatic conditions as well as the influence of two climatic patterns?the El Ni?o-Southern Oscillation and Pacific Decadal Oscillation?that impart a high degree of variability to the hydrologic cycle. Individual case studies employ a variety of geophysical and geochemical techniques to investigate recharge processes and relate the processes to local geologic and climatic conditions. All of the case studies made use of naturally occurring tracers to quantify recharge. Thermal and geophysical techniques that were developed in the course of the studies are presented in appendices. The quantification of ground-water recharge in arid settings is inherently difficult due to the generally low amount of recharge, its spatially and temporally spotty nature, and the absence of techniques for directly measuring fluxes entering the saturated zone from the unsaturated zone. Deep water tables in arid alluvial basins correspond to thick unsaturated zones that produce up to millennial time lags between changes in hydrologic conditions at the land surface and subsequent changes in recharge to underlying ground water. Recent advances in physical, chemical, isotopic, and modeling techniques have foster

  17. Estimated Recharge Rates From Groundwater Temperatures In The Nara Basin, Japan

    NASA Astrophysics Data System (ADS)

    Taniguchi, Makoto

    1994-04-01

    Groundwater recharge rates to the sandy aquifer in the Nara basin, Japan, were determined by using a theory that describes the simultaneous transfer of heat and water in a porous medium. Seasonal changes in temperatue-depth profiles were used to estimate the recharge rates in a relatively shallow aquifer. Estimations of the recharge rates were done by fitting a dimensionless parameter to the type curves developed by Taniguchi (1993) after the amplitudes of annual variations of groundwater temperatures were measured at several depths. Annual recharge rate estimated by fitting observed temperatures to the type curves was 459 mm in the Nara basin. This value agrees well with values calculated from water-balance methods and values reported in the literature.

  18. Energy-constrained open-system magmatic processes 3. Energy-Constrained Recharge, Assimilation, and

    E-print Network

    Bigelow, Stephen

    , Washington 98926, USA (bohrson@geology.cwu.edu) [1] Geochemical data for igneous rock suites provide(Tm), is specified a priori and defines how recharge magma is added to standing magma. The present EC-RAFC simulator

  19. Simulation of the Recharging Method of Implantable Biosensors Based on a Wearable Incoherent Light Source

    PubMed Central

    Song, Yong; Hao, Qun; Kong, Xianyue; Hu, Lanxin; Cao, Jie; Gao, Tianxin

    2014-01-01

    Recharging implantable electronics from the outside of the human body is very important for applications such as implantable biosensors and other implantable electronics. In this paper, a recharging method for implantable biosensors based on a wearable incoherent light source has been proposed and simulated. Firstly, we develop a model of the incoherent light source and a multi-layer model of skin tissue. Secondly, the recharging processes of the proposed method have been simulated and tested experimentally, whereby some important conclusions have been reached. Our results indicate that the proposed method will offer a convenient, safe and low-cost recharging method for implantable biosensors, which should promote the application of implantable electronics. PMID:25372616

  20. Tracking River Recharge in the Central Valley of California Using Chemical and Isotopic Tracers

    NASA Astrophysics Data System (ADS)

    Moran, J. E.; Hudson, B.; Evans, D.; Horner, T.; Leif, R.; Eaton, G. F.

    2003-12-01

    Recharge to alluvial aquifers along the major rivers of the Central Valley of California is influenced by human activity in adjacent urban areas and groundwater basins. Intense pumping of Central Valley aquifers may induce recharge, while slurry walls, emplaced for flood control in densely populated areas, are intended to protect levees by preventing shallow recharge. These large rivers carry distinct chemical and isotopic signatures that allow recent recharge to be traced in adjacent wells. In particular, stable isotopes of oxygen delineate areas where river water, carrying a depleted isotopic signature from Sierra Nevada precipitation (-11 to -15 per mil), is recharging groundwater aquifers where local precipitation is significantly heavier (-7 per mil). Trace anthropogenic compounds present in river water, such as MtBE (from precipitation and recreational boating on watershed reservoirs), are also useful for identifying areas where river water has recently infiltrated. Analysis of groundwater age, using the tritium-helium method allows estimation of the time since recharge, and evaluation of the effect of human activity on the natural groundwater recharge and flow patterns. Results from a detailed study along the American River in Sacramento, where a slurry wall is in place, show areas of recent recharge, as evidenced by relatively high MtBE concentrations (matching river concentrations) and young groundwater ages in shallow wells. In other wells, older ages and very low MtBE concentrations delineate areas where active recharge is not taking place. These results are interpreted in the context of basin-wide analyses for the Sacramento urban area, where most groundwater sampled from municipal wells is devoid of tritium, and therefore recharged more than about 50 years ago. These data are collected for the Ambient Groundwater Monitoring and Assessment (GAMA) program, sponsored by the CA State Water Resources Control Board. Oxygen isotopes indicate that American River water has recharged a large portion of this basin, with wells showing decreasing fractions of isotopically depleted water moving away from the river to the north. A similar pattern is observed in other areas of intense pumping in groundwater basins along the major rivers in the Central Valley. This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under contract No. W-7405-ENG-48.

  1. Macroscopic Thermal Energy Balance on Montane Valley Aquifers and Groundwater Recharge Source Identification

    NASA Astrophysics Data System (ADS)

    Trask, J. C.; Fogg, G. E.

    2010-12-01

    Several recent publications have highlighted the need to improve definition of groundwater flow patterns in montane regions, presenting case studies with several field investigative approaches. Determination of the depth of upland bedrock groundwater circulation and identification of valley aquifer recharge sources in montane areas is needed for improved characterization of montane groundwater flow patterns and for aquifer source protection planning. In most upland bedrock regions, wells and boreholes are scarce, adding to the challenges inherent to investigating groundwater flow in fractured rock systems. Approaches using natural environmental tracers have previously been shown to be effective in quantifying subsurface recharge into valley aquifers from groundwater flow within adjoining mountain-front and mountain-block areas. Thermal tracing of montane groundwater flow is easy and inexpensive relative to other environmental tracer and geophysical techniques, and can complement other approaches (e.g. Manning and Solomon, 2005). We present a heat flow tracer approach to identification of montane valley aquifer recharge sources. A novel application of a macroscopic thermal energy balance is introduced and used in recharge source analysis for two mountain-front bounding basin-fill aquifers located in the Sierra Nevada, USA. We show that robust upper and lower bounds on total heat flow and sources of recharge into montane valley aquifers may be determined without numerical modeling by using a macroscopic thermal energy balance. Several factors tend to enhance focusing of geothermal conductive heat flow from depth toward montane valley margins. Analytic bracketing techniques, applicable to domains with irregular boundary geometry and non-uniform thermal boundary conditions, are used together with thermal data to obtain quantitative bounds on conductive heat flow across aquifer domain boundaries. Thermal data required include: (i) a rough estimate of regional geothermal conductive heat flux at depth (available for most regions) (ii) Temperature (T) data from one or more wells in the valley aquifer (iii) data or estimates of mean annual surface T (Ts) at areal scales, and estimates of recharge T for different recharge sources. We emphasize the importance of accurate determination of Ts and recharge T for reliable modeling of subsurface heat flow. Data and models are presented showing that accurate estimates of Ts are achievable, and that subsurface T of recharge water can be substantially different from Ts near sites of intensive focused seasonal or episodic recharge. For any particular montane valley aquifer study site, we propose that a macroscopic energy balance approach to heat and groundwater flow modeling can complement and aid in development and validation of conventional grid-based numerical models. This conceptually simple approach is particularly valuable in determining the rate of aquifer recharge from cool mountain-front sources.

  2. Assessing recharge using remotely sensed data in the Guarani Aquifer System outcrop zone

    NASA Astrophysics Data System (ADS)

    Lucas, M. C.; Oliveira, P. T. S.; Melo, D. D.; Wendland, E.

    2014-12-01

    Groundwater recharge is an essential hydrology component for sustainable water withdrawal from an aquifer. The Guarani Aquifer System (GAS) is the largest (~1.2 million km2) transboundary groundwater reservoir in South America, supplying freshwater to four countries: Brazil, Argentina, Paraguay and Uruguay. However, recharge in the GAS outcrop zones is one of the least known hydrological variables, in part because studies from hydrological data are scarce or nonexistent. We assess recharge using the water-budget as the difference of precipitation (P) and evapotranspiration (ET). Data is derived from remotely sensed estimates of P (TRMM 3B42 V7) and ET (MOD16) in the Onça Creek watershed over the 2004­-12 period. This is an upland-flat watershed (slope steepness < 1%) dominated by sand soils and representative of the GAS outcrop zones. We compared the remote sensing approach against Water Table Fluctuation (WTF) method and another water-budget using ground-based measurements. Uncertainty propagation analysis were also performed. On monthly basis, TRMM P exhibited a great agreement with ground-based P data (R2 = 0.86 and RMSE = 41 mm). Historical (2004-12) mean(±sd) satellite-based recharge (Rsat) was 537(±224) mm y-1, while ground-based recharge using water-budget (Rgr) and WTF (Rwtf) method was 469 mm y-1 and 311(±150) mm y-1, respectively. We found that ~440 mm y-1 is a reasonable historical mean (between Rsat, Rgr and Rwtf) recharge for the study area over 2004-2012 period. The latter mean recharge estimate is about 29% of the mean historical P (1,514 mm y-1). Our results provide the first insight about an intercomparison of water budget from remote sensing and measured data to estimate recharge in the GAS outcrop zone. These results should be useful for future studies on assessing recharge in the GAS outcrop zones. Since accurate and precise recharge estimation still is a gap, our recharge satellite-based is considered acceptable for the Onça Creek watershed.

  3. Magnesium insertion electrodes for rechargeable nonaqueous batteries — a competitive alternative to lithium?

    Microsoft Academic Search

    Petr Novák; Roman Imhof; Otto Haas

    1999-01-01

    Magnesium-based rechargeable batteries might be an interesting future alternative to lithium-based batteries. Here the available results of research, both on rechargeable negative electrodes based either on metallic magnesium or alternative materials, and on materials suitable as positive, magnesium-inserting (counter)electrodes for secondary magnesium batteries, are critically reviewed. The reversible magnesium-metal electrode was scarcely investigated and remains poorly understood. More data are

  4. Photo-rechargeable battery using new layer compound CuFeTe 2

    Microsoft Academic Search

    T. Nomiyama; H. Kuriyaki; K. Hirakawa

    1995-01-01

    Photo-rechargeable battery is a device that converts photo-energy to electrochemical energy and stores it. Many electrode materials have been studied for this device. These materials are mainly layered semiconducting compounds. We synthesized a new layered compound CuFeTe2. In this study, CuFeTe2 was tested for photo-rechargeable battery electrode. As a result, we revealed that CuFeTe2 was charged by a Xe lamp

  5. Rechargeable batteries. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect

    Not Available

    1994-12-01

    The bibliography contains citations of selected patents concerning the design and manufacture of rechargeable batteries. Patents cover battery control and protection, electrodes, electrolytes, and packs. Citations also discuss applications in computers, telephones, cardiac pacemakers, facsimile equipment, tissue stimulators, electrical tools, heating systems, and power back-up. Solar-powered rechargeable batteries are included. (Contains a minimum of 197 citations and includes a subject term index and title list.)

  6. Rechargeable batteries. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect

    NONE

    1995-09-01

    The bibliography contains citations of selected patents concerning the design and manufacture of rechargeable batteries. Patents cover battery control and protection, electrodes, electrolytes, and packs. Citations also discuss applications in computers, telephones, cardiac pacemakers, facsimile equipment, tissue stimulators, electrical tools, heating systems, and power back-up. Solar-powered rechargeable batteries are included. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  7. Rechargeable batteries. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect

    Not Available

    1993-11-01

    The bibliography contains citations of selected patents concerning the design and manufacture of rechargeable batteries. Patents cover battery control and protection, electrodes, electrolytes, and packs. Citations also discuss applications in computers, telephones, cardiac pacemakers, facsimile equipment, tissue stimulators, electrical tools, heating systems, and power back-up. Solar-powered rechargeable batteries are included. (Contains a minimum of 170 citations and includes a subject term index and title list.)

  8. Implications of Prospective Climate Change for Groundwater Recharge in the Western United States

    NASA Astrophysics Data System (ADS)

    Meixner, T.; Manning, A. H.; Stonestrom, D. A.; Ajami, H.; Allen, D. M.; Blasch, K. W.; Brookfield, A. E.; Castro, C. L.; Clark, J. F.; Flint, A. L.; Neff, K.; Niraula, R.; Rodell, M.; Scanlon, B. R.; Singha, K.; Walvoord, M. A.

    2014-12-01

    Groundwater accounts for 25% of the United States' total water supply. Despite this importance, research efforts related to the impact of climate change on water resources have focused on surface water projections. Here we present results from a United States Geological Survey John Wesley Powell Center Group that synthesized current knowledge on groundwater recharge and the impact of climate change on recharge across the western US (west of 100o longitude). The specific aquifers considered included the High Plains Aquifer, San Pedro basin, Death Valley regional flow system, Wasatch Front aquifers, Central Valley Aquifer, Columbia Plateau Aquifer system, Spokane Valley-Rathdrum Prairie Glacial Aquifer, Williston basin and a regional overview of research on mountain aquifer systems. Combining existing studies on projected climate-change effects on recharge (available for half of the chosen systems) with expert knowledge of the remaining systems, several key patterns emerge across the region. First, our estimates indicate declines in recharge across the southern aquifers of 10-20% on average but with a wide range of uncertainty that surrounds zero change. Second, the northern tier of aquifers will likely see no change to slight increases in recharge. Third, mountain system recharge is expected to decline across the entire region due to changes in winter precipitation leading to decreased snowpack. Several critical knowledge gaps contributed uncertainty to our estimates. First, more studies coupling climate projections to groundwater systems are needed. Second, a generally poor understanding of mountain system processes is a source of significant uncertainty. Third, the response of focused recharge to potential changes in precipitation intensity and frequency is uncertain due to a lack of process understanding and the limited ability of climate projections to forecast changes in precipitation. Finally, feedbacks between climate, irrigation practices, and recharge result in significant uncertainties in several highly developed aquifer systems regarding how they might respond to climate change.

  9. A method of estimating spatio-temporally distributed groundwater recharge using integrated surface-subsurface modelling

    NASA Astrophysics Data System (ADS)

    Chung, Il Moon; Kim, Nam Won; Lee, Jeongwoo; Sophocleous, Marios

    2010-05-01

    In general, there have been various methods of estimating groundwater recharge such as baseflow separation approaches, water budget analyses based on lumped conceptual models, and the water table fluctuation method (WTF) by using data from groundwater monitoring wells. However, groundwater recharge rates show spatial-temporal variability due to climatic conditions, land use, and hydrogeological heterogeneity, so these methods have various limitations in dealing with these characteristics. To overcome these limitations, we present a novel application of estimating recharge based on water balance components from the combined SWAT-MODFLOW model, which is an integrated surface-ground water model. During the process of computing recharge, the time delay is very important factor. SWAT model uses single linear reservoir storage module with an exponential decay weighting function for accounting time delay through vadose zone. However, single reservoir module has limitation on the long delay time. So we suggest a multi-reservoir storage routing module instead of single one, which represents a more realistic time delay through the vadose zone. By using this module, the parameter related to the delay time could be optimized by checking the correlation between simulated recharge and observed groundwater levels. The final step of this procedure is to compare simulated groundwater levels as well as simulated watershed runoff with observed ones. This method is applied to several watersheds in Korea for the purpose of testing the procedure for proper estimation of spatio-temporal groundwater recharge distribution. As this application procedure of estimating recharge has the advantages of the effectiveness of a watershed model as well as the accuracy of the WTF method, the estimated daily recharge rate could be thought as an improved estimate reflecting the heterogeneity of hydrogeology, climatic conditions, land use, as well as the physical behavior of water in soil layers and aquifers.

  10. Comparison of local- to regional-scale estimates of ground-water recharge in Minnesota, USA

    Microsoft Academic Search

    Geoffrey N. Delin; Richard W. Healy; David L. Lorenz; John R. Nimmo

    2007-01-01

    Regional ground-water recharge estimates for Minnesota were compared to estimates made on the basis of four local- and basin-scale methods. Three local-scale methods (unsaturated-zone water balance, water-table fluctuations (WTF) using three approaches, and age dating of ground water) yielded point estimates of recharge that represent spatial scales from about 1 to about 1000 m2. A fourth method (RORA, a basin-scale

  11. Groundwater recharge estimation using time series models and hybrid water fluctuation method

    NASA Astrophysics Data System (ADS)

    Yoon, H.; Park, E.; Ha, K.; Kim, G.

    2013-12-01

    Predicting groundwater level fluctuations and estimating groundwater recharge are necessary for an effective management of groundwater resources. Applications of the water table fluctuation (WTF) method to groundwater recharge estimation are limited when time series data of groundwater level is discontinuous or abnormal. In the present study, we designed a method to correct abnormal data using time series models for groundwater recharge estimation. An artificial neural network and a support vector machine were employed for time series model development and the hybrid water table fluctuation method (h-WTF) considering transient fillable porosity was utilized for groundwater recharge estimation. A comparison study was conducted between three different techniques for groundwater recharge estimation: the classic WTF, h-WTF with observed data (h-WTF1), and h-WTF with corrected data (h-WTF2), using daily rainfall and groundwater level data of 5 groundwater monitoring stations in South Korea. Correlation coefficient values of observed and predicted groundwater level were as high as more than 0.8 for all the 5 stations. The result of the comparison study shows that the estimated ratio of recharge to rainfall ranges from 14.9 to 38.3% for WTF, 12.8 to 31.2% for h-WTF1, and 21.8 to 50.0% for h-WTF2 method. The estimated recharge ratios of h-WTF1 are smaller than h-WTF2 by 9.8 to 41.3%. The reason is thought to be that the effect of exogenous factors to groundwater recharge except rainfall was filtered out through the time series model in h-WTF2 method.

  12. The Effect of Ashe Juniper Removal on Groundwater Recharge in the Edwards Aquifer 

    E-print Network

    Bazan, Roberto

    2011-02-22

    to groundwater recharge. 6 Deep drainage, also referred to as recharge, occurs when water infiltrates beyond the root zone to contribute to groundwater sources. In karst landscapes infiltration can occur in two forms: micropore or macropore flow (Mc... as areas where brush control could augment water yields. This points toward karst landscapes, which are defined as terrains with high rock solubility and well a developed fracture network (Ford and Williams, 2007). Karst landscapes occupy over 10 ? 15...

  13. Water budgets and cave recharge on juniper rangelands in the Edwards Plateau 

    E-print Network

    Gregory, Lucas Frank

    2006-08-16

    . Their vast knowledge of caves, karst, and the Edwards Aquifer region has been invaluable. I extend a special thanks to Bev Shade for working with our schedules and getting permission to access the research sites and for distributing data. Thank you... rely solely on groundwater (TWDB 2002). In the Edwards Aquifer recharge zone, recharge occurs much more rapidly than in many other areas. This is largely due to the highly cavernous karst limestone that makes up the aquifer. The majority...

  14. The effect of modeled recharge distribution on simulated groundwater availability and capture.

    PubMed

    Tillman, F D; Pool, D R; Leake, S A

    2015-05-01

    Simulating groundwater flow in basin-fill aquifers of the semiarid southwestern United States commonly requires decisions about how to distribute aquifer recharge. Precipitation can recharge basin-fill aquifers by direct infiltration and transport through faults and fractures in the high-elevation areas, by flowing overland through high-elevation areas to infiltrate at basin-fill margins along mountain fronts, by flowing overland to infiltrate along ephemeral channels that often traverse basins in the area, or by some combination of these processes. The importance of accurately simulating recharge distributions is a current topic of discussion among hydrologists and water managers in the region, but no comparative study has been performed to analyze the effects of different recharge distributions on groundwater simulations. This study investigates the importance of the distribution of aquifer recharge in simulating regional groundwater flow in basin-fill aquifers by calibrating a groundwater-flow model to four different recharge distributions, all with the same total amount of recharge. Similarities are seen in results from steady-state models for optimized hydraulic conductivity values, fit of simulated to observed hydraulic heads, and composite scaled sensitivities of conductivity parameter zones. Transient simulations with hypothetical storage properties and pumping rates produce similar capture rates and storage change results, but differences are noted in the rate of drawdown at some well locations owing to the differences in optimized hydraulic conductivity. Depending on whether the purpose of the groundwater model is to simulate changes in groundwater levels or changes in storage and capture, the distribution of aquifer recharge may or may not be of primary importance. PMID:24841767

  15. An integrative approach to groundwater recharge estimation: Application to Jeju Island, Korea

    NASA Astrophysics Data System (ADS)

    Park, C.; Lee, J.; Koo, M.

    2008-12-01

    Groundwater resources in Jeju Island, a volcanic island located in the most southern region of Korea, are the only resources for water use. The island mainly consists of highly permeable volcanic materials and structures such as basaltic rocks and lava conduits. Water from precipitation barely resides on the surface and mostly infiltrates into the aquifers or discharges directly to the ocean. Thus, estimating groundwater recharge is critical to the water resource management in Jeju Island. The groundwater recharge was estimated using a GIS-based water balance model, WetSpass (Water and Energy Transfer between Soil, Plants and Atmosphere under quasi Steady State), and a physically-based groundwater flow model, MODFLOW. The WetSpass model estimates spatially varying groundwater recharge based on the surface dominant geo-spatial input parameters, such as soil property, land use, topography, groundwater depth, and meteorological data. The groundwater flow model estimates recharge by using the parameter estimation technique. Both models are complementary because the water balance equation and the groundwater flow equation are linked by a cell-based data process. The results indicated that the eastern and northern part of the Island showed relatively high values of recharge as compared to the western region. The results also showed that 65% of the total recharge occurred in higher elevations over than 200 m which would be a critical groundwater recharge area. The recharge estimation using coupled model provides more reliable results than the use of a single model and useful information for groundwater resource management and associated legislation.

  16. WetSpass: a flexible, GIS based, distributed recharge methodology for regional groundwater modelling

    Microsoft Academic Search

    OKKE BATELAAN; FLORIMOND DE SMEDT

    2001-01-01

    Regional groundwater models used for analysing groundwater systems (infiltration-discharge relations) are often quasi-steady state and therefore need long-term average recharge input. On the other hand, the spatial variation in the recharge due to distributed land-use, soil type, slope, groundwater level, meteorological conditions, etc. can be significant and should be accounted for. Hence, WetSpass was built as a physically based methodology

  17. Tritium as an indicator of recharge and dispersion in a groundwater system in central Ontario

    Microsoft Academic Search

    W. D. Robertson; J. A. Cherry

    1989-01-01

    The detailed distribution of tritium (3H) in the recharge area of a shallow unconfined sand aquifer near Sturgeon Falls, Ontario, is described. At this forested, shallow water table site, bomb tritium has penetrated uniformly to a depth of 8-12 m indicating recharge of 15 cm\\/year, which is 16% of precipitation. The zone of bomb tritium contains 3H concentrations of from

  18. Estimation of groundwater recharge using a GIS-based distributed water balance model in Dire Dawa, Ethiopia

    NASA Astrophysics Data System (ADS)

    Tilahun, Ketema; Merkel, Broder J.

    2009-09-01

    Sustainable groundwater management requires knowledge of recharge. Recharge is also an important parameter in groundwater flow and transport models. Spatial variation in recharge due to distributed land-us.e, soil texture, topography, groundwater level, and hydrometeorological conditions should be accounted for in recharge estimation. However, conventional point-estimates of recharge are not easily extrapolated or regionalized. In this study, a spatially distributed water balance model WetSpass was used to simulate long-term average recharge using land-use, soil texture, topography, and hydrometeorological parameters in Dire Dawa, a semiarid region of Ethiopia. WetSpass is a physically based methodology for estimation of the long-term average spatial distribution of surface runoff, actual evapotranspiration, and groundwater recharge. The long-term temporal and spatial average annual rainfall of 626 mm was distributed as: surface runoff of 126 mm (20%), evapotranspiration of 468 mm (75%), and recharge of 28 mm (5%). This recharge corresponds to 817 l/s for the 920.12 km2 study area, which is less than the often-assumed 1,000 l/s recharge for the Dire Dawa groundwater catchment.

  19. Groundwater level monitoring and recharge estimation in the White Volta River basin of Ghana

    NASA Astrophysics Data System (ADS)

    Obuobie, Emmanuel; Diekkrueger, Bernd; Agyekum, William; Agodzo, Sampson

    2012-08-01

    Recharge quantification is an important pre-requisite for effectively managing groundwater resources as recharge estimates are needed to determine sustainable yields of groundwater aquifers for rational and sustainable exploitation of the resource. In this study, the water table fluctuation method has been applied in the White Volta River basin of Ghana (approx. 46,000 km2) to estimate seasonal fluctuations in groundwater levels in the basin and subsequently to estimate recharge to the groundwater for the 2006 and 2007 water years. Results show high seasonal and spatial variability in the water level, with a range of 1240-5000 mm in 2006, and 1600-6800 mm in 2007. Seasonal rainfall was found to be the main source of recharge to the aquifers in the basin as water level rise occurred only in the rainfall season. Recharge to groundwater in the White Volta basin was estimated to vary between 2.5% and 16.5% of the mean annual rainfall, with a mean recharge of 7-8%.

  20. Effects of topography and soil properties on recharge at two sites in an agricultural field

    USGS Publications Warehouse

    Delin, G.N.; Healy, R.W.; Landon, M.K.; Böhlke, J.K.

    2000-01-01

    Field experiments were conducted from 1992 to 1995 to estimate ground water recharge rates at two sites located within a 2.7-hectare agricultural field. The field lies in a sand plain setting in central Minnesota and is cropped continuously in field corn. The sites are located at a topographically high (upland) site and a topographically low (lowland) site in an effort to quantify the effects of depression focusing of recharge. Three site-specific methods were used to estimate recharge rates: Well hydrograph analysis, chlorofluorocarbon age dating, and an unsaturated zone water balance. All three recharge methods indicated that recharge rates at the lowland site (annual average of all methods of 29 cm) exceeded those at the upland site (annual average of 18 cm). On an annual basis, estimates by the individual methods ranged from 12 to 44 percent of precipitation at the upland site and from 21 to 83 percent at the lowland site. The difference in recharge rates between the sites is primarily attributed to depression focusing of surface water runon at the lowland site. However, two other factors were also important: The presence of thin lamellae at the upland site, and coarser textured soils below a depth of 1.5 m at the lowland site.

  1. Groundwater recharge to a sedimentary aquifer in the topographically closed Uley South Basin, South Australia

    NASA Astrophysics Data System (ADS)

    Ordens, Carlos M.; Werner, Adrian D.; Post, Vincent E. A.; Hutson, John L.; Simmons, Craig T.; Irvine, Benjamin M.

    2012-02-01

    The chloride mass balance (CMB) and water-table fluctuation (WTF) analysis methods were used to estimate recharge rates in the Uley South Basin, South Australia. Groundwater hydrochemistry and isotope data were used to infer the nature of recharge pathways and evapotranspiration processes. These data indicate that some combination of two plausible processes is occurring: (1) complete evaporation of rainfall occurs, and the precipitated salts are washed down and redissolved when recharge occurs, and (2) transpiration dominates over evaporation. It is surmised that sinkholes predominantly serve to by-pass the shallow soil zone and redistribute infiltration into the deeper unsaturated zone, rather than transferring rainfall directly to the water table. Chlorofluorocarbon measurements were used in approximating recharge origins to account for coastal proximity effects in the CMB method and pumping seasonality was accounted for in the WTF-based recharge estimates. Best estimates of spatially and temporally averaged recharge rates for the basin are 52-63 and 47-129 mm/year from the CMB and WTF analyses, respectively. Adaptations of both the CMB and WTF analyses to account for nuances of the system were necessary, demonstrating the need for careful application of these methods.

  2. A Watershed Approach for the Determination of Groundwater Recharge in Rajasthan, India

    NASA Astrophysics Data System (ADS)

    Rohde, M. M.; Edmunds, W.; Sharma, O.; Sharma, A.

    2011-12-01

    The determination of groundwater recharge is imperative for sustainable water management, particularly in semi-arid regions where mitigation and adaptation strategies are needed. Two-thirds of India is underlain by hard rocks, and appropriate techniques for the estimation of groundwater recharge are currently problematic in such areas. Chloride mass balance (CMB) has been employed in this study to determine recharge rates from groundwater collected from a monsoon dependent area in the Aravalli Hills in Rajasthan, India. A monitoring program was established in the summer of 2009 in the Gangeshwar Watershed with local participation for the collection of rainfall and groundwater samples. Groundwater recharge estimation was spatially determined over a 3-year period with pre-monsoon and post-monsoon datasets. Irrigation return flow was likely to impact 90% of the samples, and has thus required stable isotope analysis using hydrogen (?2H) and oxygen (?18O) to corroborate nitrate and other anionic chemistry to determine sources of groundwater recharge. The possibilities of using total dissolved solutes (TDS) as an alternative for chloride have also been addressed as a way to simplify the determination of groundwater recharge at the user-level.

  3. Transmission losses, infiltration and groundwater recharge through ephemeral and intermittent streambeds: A review of applied methods

    NASA Astrophysics Data System (ADS)

    Shanafield, Margaret; Cook, Peter G.

    2014-04-01

    Aquifer recharge through ephemeral streambeds is believed to be a major source of groundwater recharge in arid areas; however, comparatively few studies quantify this streamflow recharge. This review synthesizes the available field-based aquifer recharge literature from arid regions around the world. Seven methods for quantifying ephemeral and intermittent stream infiltration and aquifer recharge are reviewed; controlled infiltration experiments, monitoring changes in water content, heat as a tracer of infiltration, reach length water balances, floodwave front tracking, groundwater mounding, and groundwater dating. The pertinent temporal and spatial scales, as well as the advantages and limitations of each method are illustrated with examples from the literature. Comparisons between the methods are used to highlight appropriate uses of each field method, with emphasis on the advantages of using multiple methods within a study in order to avoid the potential drawbacks inherent in any single method. Research needs are identified, including: quantitative uncertainty analysis, long-term data collection and analysis, understanding of the role of riparian vegetation, and reconciliation of transmission losses and infiltration estimates with actual aquifer recharge.

  4. A water-budget model and estimates of groundwater recharge for Guam

    USGS Publications Warehouse

    Johnson, Adam G.

    2012-01-01

    On Guam, demand for groundwater tripled from the early 1970s to 2010. The demand for groundwater is anticipated to further increase in the near future because of population growth and a proposed military relocation to Guam. Uncertainty regarding the availability of groundwater resources to support the increased demand has prompted an investigation of groundwater recharge on Guam using the most current data and accepted methods. For this investigation, a daily water-budget model was developed and used to estimate mean recharge for various land-cover and rainfall conditions. Recharge was also estimated for part of the island using the chloride mass-balance method. Using the daily water-budget model, estimated mean annual recharge on Guam is 394.1 million gallons per day, which is 39 percent of mean annual rainfall (999.0 million gallons per day). Although minor in comparison to rainfall on the island, water inflows from water-main leakage, septic-system leachate, and stormwater runoff may be several times greater than rainfall at areas that receive these inflows. Recharge is highest in areas that are underlain by limestone, where recharge is typically between 40 and 60 percent of total water inflow. Recharge is relatively high in areas that receive stormwater runoff from storm-drain systems, but is relatively low in urbanized areas where stormwater runoff is routed to the ocean or to other areas. In most of the volcanic uplands in southern Guam where runoff is substantial, recharge is less than 30 percent of total water inflow. The water-budget model in this study differs from all previous water-budget investigations on Guam by directly accounting for canopy evaporation in forested areas, quantifying the evapotranspiration rate of each land-cover type, and accounting for evaporation from impervious areas. For the northern groundwater subbasins defined in Camp, Dresser & McKee Inc. (1982), mean annual baseline recharge computed in this study is 159.1 million gallons per day, which is 50 percent of mean annual rainfall, and is 42 percent greater than the recharge estimate of Camp, Dresser & McKee Inc. (1982). For the northern aquifer sectors defined in Mink (1991), which encompass most of the northern half of the island, mean annual baseline recharge computed in this study is 238.0 million gallons per day, which is 51 percent of mean annual rainfall, and is about 6 percent lower than the recharge estimate of Mink (1991). For the drought simulation performed in this study, recharge for the entire island is 259.3 million gallons per day, which is 34 percent lower than recharge computed for baseline conditions. For all aquifer sectors defined by Mink (1991), total recharge during drought conditions is 32 percent lower than mean baseline recharge. For the future land-cover water-budget simulation, which represents potential land-cover changes owing to the military relocation and population growth, estimated recharge for the entire island is nearly equal to the baseline recharge estimate that was based on 2004 land cover. Using the water-budget model, estimated recharge in the northern half of the island is most sensitive to crop coefficients and net precipitation rates—two of the water-budget parameters used in the estimation of total evapotranspiration. Estimated recharge in the southern half of the island is most sensitive to crop coefficients, net precipitation rate, and runoff-to-rainfall ratios. During March 2010 to May 2011, bulk-deposition samples from five rainfall stations on Guam were collected and analyzed for chloride. Additionally, samples from five groundwater sites were collected and analyzed for chloride. Results were used to estimate groundwater recharge using the chloride mass-balance method. Recharge estimates using this method at three bulk-deposition stations on the northern limestone plateau range from about 25 to 48 percent of rainfall. These recharge estimates are similar to the estimate of Ayers (1981) who also used this method. Recharge estimates at each bulk-deposition station, however, are lower

  5. Calculating the average natural recharge in large areas as a factor of their lithology and precipitation

    NASA Astrophysics Data System (ADS)

    Sanz, E.; Menéndez Pidal de Navascués, I.; Távara, C.

    2011-05-01

    In an area as large as Spain, it is shown by statistical inference on a sample of 875 springs (with discharges greater than 10 l s-1), whose average flow, lithology and catchment areas are known, and which were grouped into regions of contrasting rainfall, that the average annual recharge is a fixed fraction of annual rainfall for each lithology. Recharge rates have thus been established with respect to rainfall for six lithological groups of different permeability: sands, gravels and generally alluvial formations 8.3%; conglomerates, 5.6%; sandstones, 7.3%; limestone and dolomite 34.3%; marls, marly limestones, silts and clays, 3.3%; and hard rocks, 1.3%. Since Spain can be considered to be representative, given its large size and a highly varied lithology, topography and rainfall, these recharge rates with respect to rainfall are probably quasi-universal values, which can be used to estimate the average recharge or average groundwater resources of large regions in any part of the world (except in special cases such as areas that have permafrost). In any case, the recharge rates can be adapted for each region according to its particular characteristics. Rainfall and lithology data are abundant, and so the method can be widely used to calculate hydraulic balances. The method has been applied to the Duero basin in Spain and to other European countries (Portugal, Ireland and Italy), obtaining recharge results that are very similar to those calculated by other methods.

  6. Estimating spatial variability of recharge in southern New Jersey from unsaturated-zone measurements

    USGS Publications Warehouse

    Baehr, Arthur L.; Kauffman, Leon J.; Perkins, Kimberlie; Nolan, Bernard T.

    2003-01-01

    Spatial variability of recharge in southern New Jersey was studied by sampling the unsat-urated zone at 48 sites distributed over approximately 930 square kilometers. Samples of unsaturated-zone sediment were collected during the summer and fall of 1996. Unsaturated flow was calculated using moisture-content data and estimates of conductivity and matric potential derived from sediment-size data. Matric forces were found to be important at about 70 percent of the sites despite the expectation that unsaturated flow in a humid climate is gravity driven. Upward water movement occurred at about 17 percent of the sites. The lower sediment layer at these sites consisted of sandy loam, indicating that upward movement can occur at depth only where the sediments are relatively fine-grained. At the other extreme, calculated flow at about 17 percent of the sites exceeded 250 centimeters per year. Because of the uncertainty inherent in unsaturated-flow calculations, the method provides only a scaling of recharge variability; however, the median calculated flow of 29.1 centimeters per year compares favorably with recharge estimates from previous water-budget studies. A map developed by spatial analysis of the recharge estimates identified an agricultural part of the study area where recharge was known to be low relative to recharge in other basins.

  7. Electrochemical impedance spectroscopy of lithium-titanium disulfide rechargeable cells

    NASA Technical Reports Server (NTRS)

    Narayanan, S. R.; Shen, D. H.; Surampudi, S.; Attia, A. I.; Halpert, G.

    1993-01-01

    The two-terminal alternating current impedance of Li/TiS2 rechargeable cells was studied as a function of frequency, state-of-charge, and extended cycling. Analysis based on a plausible equivalent circuit model for the Li/TiS2 cell leads to evaluation of kinetic parameters for the various physicochemical processes occurring at the electrode/electrolyte interfaces. To investigate the causes of cell degradation during extended cycling, the parameters evaluated for cells cycled 5 times were compared with the parameters of cells cycled over 600 times. The findings are that the combined ohmic resistance of the electrolyte and electrodes suffers a tenfold increase after extended cycling, while the charge-transfer resistance and diffusional impedance at the TiS2/electrolyte interface are not significantIy affected. The results reflect the morphological change and increase in area of the anode due to cycling. The study also shows that overdischarge of a cathode-limited cell causes a decrease in the diffusion coefficient of the lithium ion in the cathode.

  8. Anticandidal Activity and Biocompatibility of a Rechargeable Antifungal Denture Material

    PubMed Central

    Villar, Cristina C.; Lin, Alan L.; Cao, Zhengbing; Zhao, Xiang-Ru; Wu, Li-An; Chen, Shuo; Sun, Yuyu; Yeh, Chih-Ko

    2013-01-01

    Objectives Candida-associated denture stomatitis is a recurrent and debilitating oral mucosal disease. Development of anticandidal denture materials represents a promising strategy to manage this condition. We have previously shown that miconazole incorporated in methacrylic acid (MAA) copolymerized diurethane dimethacrylate (UDMA) denture materials has long-term anticandidal activity. In this study, we examined the ability of culture medium conditioned with drug-free- or miconazole-MAA-UDMA discs to prevent Candida infection in an in vitro oral epithelial cell/Candida albicans co-culture system. Material and Methods Candida albicans (C. albicans) induced OKF6/TERT-2 cell damage was quantified by the release of lactate dehydrogenase from epithelial cells, cytokine production was quantified using protein cytokine arrays, and the expression of C. albicans genes was measured by RT-qPCR. Results C. albicans had limited growth with altered expression levels of secreted aspartyl proteinase-2 and -5 in culture medium conditioned by miconazole-MAA-UDMA discs. Significantly, the ability of C. albicans to induce oral epithelial cell damage and trigger epithelial proinflammatory cytokine production was also inhibited by miconazole disc conditioned media. Conclusion Miconazole released from MAA-UDMA denture materials effectively prevents the development of candidal infection in an in vitro oral epithelial system. Further characterization of this drug-rechargeable denture material is warranted. PMID:22957799

  9. Rechargeable aluminum batteries with conducting polymers as positive electrodes.

    SciTech Connect

    Hudak, Nicholas S.

    2013-12-01

    This report is a summary of research results from an Early Career LDRD project con-ducted from January 2012 to December 2013 at Sandia National Laboratories. Demonstrated here is the use of conducting polymers as active materials in the posi-tive electrodes of rechargeable aluminum-based batteries operating at room tempera-ture. The battery chemistry is based on chloroaluminate ionic liquid electrolytes, which allow reversible stripping and plating of aluminum metal at the negative elec-trode. Characterization of electrochemically synthesized polypyrrole films revealed doping of the polymers with chloroaluminate anions, which is a quasi-reversible reac-tion that facilitates battery cycling. Stable galvanostatic cycling of polypyrrole and polythiophene cells was demonstrated, with capacities at near-theoretical levels (30-100 mAh g-1) and coulombic efficiencies approaching 100%. The energy density of a sealed sandwich-type cell with polythiophene at the positive electrode was estimated as 44 Wh kg-1, which is competitive with state-of-the-art battery chemistries for grid-scale energy storage.

  10. Modeling soil moisture processes and recharge under a melting snowpack

    USGS Publications Warehouse

    Flint, A.L.; Flint, L.E.; Dettinger, M.D.

    2008-01-01

    Recharge into granitic bedrock under a melting snowpack is being investigated as part of a study designed to understand hydrologic processes involving snow at Yosemite National Park in the Sierra Nevada Mountains of California. Snowpack measurements, accompanied by water content and matric potential measurements of the soil under the snowpack, allowed for estimates of infiltration into the soil during snowmelt and percolation into the bedrock. During portions of the snowmelt period, infiltration rates into the soil exceeded the permeability of the bedrock and caused ponding to be sustained at the soil-bedrock interface. During a 5-d period with little measured snowmelt, drainage of the ponded water into the underlying fractured granitic bedrock was estimated to be 1.6 cm d?1, which is used as an estimate of bedrock permeability. The numerical simulator TOUGH2 was used to reproduce the field data and evaluate the potential for vertical flow into the fractured bedrock or lateral flow at the bedrock-soil interface. During most of the snowmelt season, the snowmelt rates were near or below the bedrock permeability. The field data and model results support the notion that snowmelt on the shallow soil overlying low permeability bedrock becomes direct infiltration unless the snowmelt rate greatly exceeds the bedrock permeability. Late in the season, melt rates are double that of the bedrock permeability (although only for a few days) and may tend to move laterally at the soil-bedrock interface downgradient and contribute directly to streamflow. ?? Soil Science Society of America.

  11. Silicon anode for rechargeable aqueous lithium-air batteries

    NASA Astrophysics Data System (ADS)

    Teranishi, R.; Si, Q.; Mizukoshi, F.; Kawakubo, M.; Matsui, M.; Takeda, Y.; Yamamoto, O.; Imanishi, N.

    2015-01-01

    A novel aqueous lithium-air rechargeable cell with the configuration of Si/1 M LiClO4 in ethylene carbonate-diethylene carbonate/Li1+x+yAlx(Ti,Ge)2-xP3-ySiyO12/5 M LiCl-1 M LiOH aqueous solution/carbon black, air is proposed. A silicon anode composed of mechanically milled silicon power with an average particle size of ca. 0.5 ?m, vapor grown carbon fiber and a polyimide binder was examined. The open-circuit voltage at the charged state was 2.9 V at 25 °C. The discharge capacity of 700 mAh g-silicon-1 was retained for 40 cycles at 0.3 mA cm-2 with cut-off voltages of 3.5 and 1.5 V. Significant capacity fade was observed at deep charge and discharge cycling at 2000 mAh g-silicon-1.

  12. A single flow zinc//polyaniline suspension rechargeable battery

    NASA Astrophysics Data System (ADS)

    Zhao, Yongfu; Si, Shihui; Liao, Cui

    2013-11-01

    Both the electrochemical activity and the energy density of polyaniline (PANI) microparticles suspensions are enhanced by using the compact PANI powder, which is synthesized galvanostatically with 4,4?-diaminobiphenyl as additive. A Zn//PANI suspension rechargeable flow battery system is proposed, in which the flowable PANI suspension is used as cathode electroactive material, zinc plate as anode. A microporous membrane is used as separator to prevent PANI particles from getting into the anode compartment. Results obtained from the small laboratory battery show that the discharge capacity density gradually decreases with number of cycles and the average of discharge capacity loss during 32 cycles is about 0.07% per cycle. However, an average coulombic efficiency of 97% has been achieved at the current density of 20 mA cm-2 and the value of coulombic efficiency shows no significant change during 32 charge/discharge cycles. The flow-through mode for PANI cathode material enables the PANI-based battery to operate at a higher current density in comparison with the conventional Zn-PANI film batteries, and the present findings can mark a new route to improve the performance of conductive polymer-based energy storage devices.

  13. Rechargeable LiNiO2/carbon cells

    NASA Astrophysics Data System (ADS)

    Dahn, J. R.; von Sacken, U.; Juzkow, M. W.; Al-Janaby, H.

    1991-08-01

    Rechargeable cells can be made using two different intercalation compounds, in which the chemical potential of the intercalant differs by several eV, for the electrodes. The factors that play a role in the selection of appropriate lithium intercalation compounds for such cells are discussed. For the ease of cell assembly, the cathode should be stable in air when it is fully intercalated, like LiNiO2. For the anode, the chemical potential of the intercalated Li should be close to that of Li metal, like it is in Li(x)C6. The intercalation of Li in LiNiO2 is discussed, and then in petroleum coke. Then, it is shown that LiNiO2/coke cells have high energy density, long cycle life, excellent high-temperature performance, low self-discharge rates, can be repeatedly discharged to zero volts without damage, and are easily fabricated. It is considered that this type of cell shows far more promise for widespread applications than traditional secondary Li cells using metallic Li anodes.

  14. Rechargeable batteries: advances since 1977. [Collection of US patents

    SciTech Connect

    Graham, R.W. (ed.)

    1980-01-01

    This book is based on US patents (including DOE patents) issued since January 1978 that deal with rechargeable batteries. It both supplies detailed technical information and can be used as a guide to the patent literature. Subjects treated are as follows: lead-acid batteries (grids, electrodes, terminals and connectors, polyolefin separators, polyvinyl chloride separators, other polymeric separators, other separators, electrolytes, venting techniques, hydrogen-oxygen recombination, general construction and fabrication), lithium batteries (metal chalcogenide cathodes, chalcogenide electrolyte compositions, chalcogenide batteries, lithium anodes, cathodes, lithium-thionyl chloride batteries, lithium-bromine batteries, electrolyte additives and other processes), sodium-sulfur batteries (general battery design, sulfur electrodes, sealing and casing design, current collectors, other processes), alkaline zinc and iron electrode batteries (silver-zinc, nickel-zinc, air-zinc, other zinc electrode processes, iron electrode batteries), zinc-halogen batteries (electrodes, electrolyte additives, other zinc-halogen batteries, zinc-manganese dioxide acid electrolyte), nickel-cadmium and nickel-hydrogen batteries (nickel-cadmium electrodes, other processes for nickel-cadmium batteries, nickel-hydrogen electrodes, other processes for nickel-hydrogen batteries, other nickel-containing batteries), and other battery systems (battery systems and design, other processes). (RWR)

  15. Groundwater recharge patterns on hillslopes: exploring the role of soil depth, bedrock permeability, and lateral flow

    NASA Astrophysics Data System (ADS)

    Appels, W. M.; Graham, C. B.; McDonnell, J. J.

    2013-12-01

    The hillslope scale patterns of groundwater recharge are poorly known. On hillslopes with a thin soil mantle overlying bedrock, complex interactions of percolation of water through the soil, permeability contrasts between the soil and the underlying bedrock, and lateral redistribution of water result in large spatial variability of infiltration of water into the bedrock. Here, we combine new measurements and a new modeling approach to explore the following questions: what are the characteristics of the spatial patterns of soil depth, bedrock topography, and bedrock permeability on a hillslope?; and how do these patterns affect the spatial variability of groundwater recharge? We have put new measurements of permeability of the soil mantle and bedrock of the well-studied Panola Mountain experimental hillslope together with previously collected (sub)surface topography and soil depth data. We developed a conceptual model to explore how the recharge pattern varies during different precipitation events. With the geostatistical characteristics of the measured permeability, we generated spatial fields of bedrock permeability for the entire hillslope. We performed model simulations with these random fields and evaluated the resulting spatial distribution of groundwater recharge during individual and series of rainfall events. We found that the average amount of recharge into the bedrock was determined by the ratio between the rate of water delivery through the soil and over the soil-bedrock interface and the bedrock permeability. On the timescale of a single rainfall event, deviations from the average recharge rates were caused by soil depth and local variations of bedrock permeability. When considering a series of rainfall events, a larger fraction of the total rainfall was now delivered at lower rates to the soil-bedrock interface, resulting in a smoother groundwater recharge pattern. Higher groundwater recharge rates were found where lateral flow along the soil-bedrock interface concentrated. Not all areas of concentrated lateral flow on the hillslope featured higher groundwater recharge volumes, because run-on along the soil-bedrock interface was not uniformly generated on the hillslope. Changing the characteristic length of the spatial pattern of bedrock permeability resulted in a different positioning and extent of patches of increased groundwater recharge on the Panola hillslope.

  16. Use of environmental isotope tracer and GIS techniques to estimate basin recharge

    NASA Astrophysics Data System (ADS)

    Odunmbaku, Abdulganiu A. A.

    The extensive use of ground water only began with the advances in pumping technology at the early portion of 20th Century. Groundwater provides the majority of fresh water supply for municipal, agricultural and industrial uses, primarily because of little to no treatment it requires. Estimating the volume of groundwater available in a basin is a daunting task, and no accurate measurements can be made. Usually water budgets and simulation models are primarily used to estimate the volume of water in a basin. Precipitation, land surface cover and subsurface geology are factors that affect recharge; these factors affect percolation which invariably affects groundwater recharge. Depending on precipitation, soil chemistry, groundwater chemical composition, gradient and depth, the age and rate of recharge can be estimated. This present research proposes to estimate the recharge in Mimbres, Tularosa and Diablo Basin using the chloride environmental isotope; chloride mass-balance approach and GIS. It also proposes to determine the effect of elevation on recharge rate. Mimbres and Tularosa Basin are located in southern New Mexico State, and extend southward into Mexico. Diablo Basin is located in Texas in extends southward. This research utilizes the chloride mass balance approach to estimate the recharge rate through collection of groundwater data from wells, and precipitation. The data were analysed statistically to eliminate duplication, outliers, and incomplete data. Cluster analysis, piper diagram and statistical significance were performed on the parameters of the groundwater; the infiltration rate was determined using chloride mass balance technique. The data was then analysed spatially using ArcGIS10. Regions of active recharge were identified in Mimbres and Diablo Basin, but this could not be clearly identified in Tularosa Basin. CMB recharge for Tularosa Basin yields 0.04037mm/yr (0.0016in/yr), Diablo Basin was 0.047mm/yr (0.0016 in/yr), and 0.2153mm/yr (0.00848in/yr) for Mimbres Basin. The elevation where active recharge occurs was determined to be 1,500m for Mimbres and Tularosa Basin and 1,200m for Diablo Basin. The results obtained in this study were consistent with result obtained by other researchers working in basins with similar semiarid mountainous conditions, thereby validating the applicability of CMB in the three basins. Keywords: Recharge, chloride mass balance, elevation, Mimbres, Tularosa, Diablo, Basin, GIS, chloride, elevation.

  17. Chloride mass-balance method for estimating ground water recharge in arid areas: Examples from western Saudi Arabia

    USGS Publications Warehouse

    Bazuhair, A.S.; Wood, W.W.

    1996-01-01

    The chloride mass-balance method, which integrates time and aerial distribution of ground water recharge, was applied to small alluvial aquifers in the wadi systems of the Asir and Hijaz mountains in western Saudi Arabia. This application is an extension of the method shown to be suitable for estimating recharge in regional aquifers in semi-arid areas. Because the method integrates recharge in time and space it appears to be, with certain assumptions, particularly well suited for and areas with large temporal and spatial variation in recharge. In general, recharge was found to be between 3 to 4% of precipitation - a range consistent with recharge rates found in other arid and semi-arid areas of the earth.

  18. Artificial-recharge tests in Upper Black Squirrel Creek basin, Jimmy Camp Valley, and Fountain Valley, El Paso County, Colorado

    USGS Publications Warehouse

    Emmons, P.J.

    1977-01-01

    Artificial-recharge tests were conducted in the alluvium in upper Black Squirrel Creek basin, the alluvium in Jimmy Camp Valley, and in the alluvium overlying the Widefield aquifer which is located in an ancestral channel in Fountain Valley, Colo. Nine artificial-recharge pits with areas of approximately 9,200 square feet each were excavated in the unsaturated zones above the three aquifers. Each artificial-recharge site was instrumented to measure inflow, stage fluctuations, and water-table fluctuations. Artificial-recharge tests of approximately 10 days ' duration were conducted at each of the nine artificial-recharge sites and one extended test of approximately 30 days ' duration was conducted in each of the three study areas. Periphyton growth, present in most of the artificial-recharge ponds, was insufficient to cause noticeable decline in the rate of infiltration. (Woodard-USGS)

  19. Changing fuel specifications

    SciTech Connect

    Hatt, R.

    1995-08-01

    This paper will describe the goals, methods, and results of a program designed to expand fuel specifications. The ability to expand fuel specs can provide many advantages to a power company. These would include increased fuel flexibility, better performance and lower fuel cost. The expansion of transportation modes also may enhance the scenario. Although brief, this paper should provide a good understanding of the types of problems that can be encountered, and the cooperative effort necessary to resolve them.

  20. Fossil fuels -- future fuels

    SciTech Connect

    NONE

    1998-03-01

    Fossil fuels -- coal, oil, and natural gas -- built America`s historic economic strength. Today, coal supplies more than 55% of the electricity, oil more than 97% of the transportation needs, and natural gas 24% of the primary energy used in the US. Even taking into account increased use of renewable fuels and vastly improved powerplant efficiencies, 90% of national energy needs will still be met by fossil fuels in 2020. If advanced technologies that boost efficiency and environmental performance can be successfully developed and deployed, the US can continue to depend upon its rich resources of fossil fuels.

  1. Detailed Guidelines for Recharge Activities and Rates This document applies to the operation, conduct and approval of recharge activities for service

    E-print Network

    Ferrara, Katherine W.

    develop rates that recover all the direct costs of the recharge activity and, when appropriate, indirect costs. 2. Direct and Indirect Costs a. Direct Costs: Rates are based on estimates of direct costs. Rates record the full costs (including the subsidy) for the activity in an identifiable account. #12;8. Units

  2. Effects of a Changing Climate on Seasonal Variation in Natural Recharge of Unconfined Coastal Aquifers

    NASA Astrophysics Data System (ADS)

    Antonellini, Marco; Nella Mollema, Pauline

    2013-04-01

    Irregular rainfall patterns throughout the year result in the discontinuous natural recharge of coastal aquifers, which has an effect on the size of freshwater lenses present in sandy deposits. The thickness of the freshwater lenses is important in the context of farmland salinization and coastal ecosystems survival. This study presents numerical models that simulate continuous and discontinuous recharge in sandy coastal aquifers and the thickness of resulting fresh water lenses under current and future climate scenarios. Temperature data for the period 1960-1990 from LOCCLIM FAO and from the IPCC SRES A1b scenario for 2070-2100, have been used to calculate the potential evapotranspiration. Potential recharge was defined as the difference between the precipitation and potential evapotranspiration in twelve locations around the world: Ameland (The Netherlands), Auckland and Wellington (New Zealand), Hong Kong, Ravenna (Italy), Mekong (Vietnam), Mumbai (India), New Jersey (USA), Nile Delta (Egypt), Kobe and Tokyo (Japan), and Singapore. These locations have shallow coastal aquifers along low lying coasts and comparable aquifer structure, which is the result of similar sediment supply and deposition in the Holocene as well as by the sea level changes from the last ice age to the present time. Particular attention has been paid to temporal variations of natural recharge that can vary from continuous recharge throughout the year to discontinuous recharge. The most dramatic reduction in the magnitude of potential annual recharge by the end of this century will occur at lower latitudes (Mumbai, Singapore, Hong Kong and Mekong). The most pronounced change in length of the dry period occurs for Kobe (Japan) and Singapore even though the total annual amount of recharge remains practically the same. The Influence of variable recharge on the size of freshwater lenses surrounded by saline water is simulated with the SEAWAT model. Models where the recharge is applied continuously throughout the year result in thicker freshwater lenses than models with the same amount of potential recharge applied discontinuously. This difference between the discontinuous and the continuous model is relatively small in areas where the total annual recharge is low (Wellington NZ, Ravenna IT, Ameland NL) but in places with Monsoon-dominated climate as Mumbai, the difference is large. Under the IPCC A1b climate scenario, only Tokyo and Singapore appear to change from a continuous to a discontinuous recharge regime whereas in the other locations there is merely a change in the amount of annual recharge, mostly reducing the size of the freshwater lenses (Ameland, Mekong, Mumbai, Hong Kong and Ravenna). In low latitudes settings such as Mumbai, Mekong Delta, and Hong Kong, this change is more dramatic with large losses of freshwater. This study shows that it is important to consider seasonal variations in temperature and precipitation in water resources management in the coastal zone, especially in view of climatic change.

  3. Copper-palladium core-shell as an anode in a multi-fuel membraneless nanofluidic fuel cell: toward a new era of small energy conversion devices.

    PubMed

    Maya-Cornejo, J; Ortiz-Ortega, E; Álvarez-Contreras, L; Arjona, N; Guerra-Balcázar, M; Ledesma-García, J; Arriaga, L G

    2015-02-14

    A membraneless nanofluidic fuel cell with flow-through electrodes that works with several fuels (individually or mixed): methanol, ethanol, glycerol and ethylene-glycol in alkaline media is presented. For this application, an efficient Cu@Pd electrocatalyst was synthesized and tested, resulting outstanding performance until now reported, opening the possibility of power nano-devices for multi-uses purposes, regardless of fuel re-charge employed. PMID:25566986

  4. NUCLEAR-FUELED CIRCULATORY SUPPORT SYSTEMS IV: RADIOLOGIC PERSPECTIVES.

    PubMed

    Huffman, F N; Norman, J C

    1974-01-01

    If an implantable artificial heart can be developed, it should prove beneficial to a significant group of patients. A variety of energy sources, such as biologic, electromagnetic, and nuclear, are under evaluation. Currently, biologic fuel cell technology is not sufficiently advanced to permit its extrapolation to the power levels required for implantable circulatory support systems. Electromagnetic systems have the disadvantage of heavy batteries of considerable bulk requiring frequent recharging. Radioisotope-fueled thermal engine systems have the potential of providing degrees of freedom not possible with rechargeable units. However, radiosotope circulatory support systems subject their recipients to prolonged intracorporeal radiation, add to environmental background radiation, and constitute an exceedingly small, but finite, hazard due to possible violation of fuel containment. PMID:15215965

  5. NUCLEAR-FUELED CIRCULATORY SUPPORT SYSTEMS IV: RADIOLOGIC PERSPECTIVES

    PubMed Central

    Huffman, F. N.; Norman, J. C.

    1974-01-01

    If an implantable artificial heart can be developed, it should prove beneficial to a significant group of patients. A variety of energy sources, such as biologic, electromagnetic, and nuclear, are under evaluation. Currently, biologic fuel cell technology is not sufficiently advanced to permit its extrapolation to the power levels required for implantable circulatory support systems. Electromagnetic systems have the disadvantage of heavy batteries of considerable bulk requiring frequent recharging. Radioisotope-fueled thermal engine systems have the potential of providing degrees of freedom not possible with rechargeable units. However, radiosotope circulatory support systems subject their recipients to prolonged intracorporeal radiation, add to environmental background radiation, and constitute an exceedingly small, but finite, hazard due to possible violation of fuel containment. PMID:15215965

  6. On the Prediction of Ground-Water Mound Formation in Response to Transient Recharge from a Circular Basin

    Microsoft Academic Search

    S. N. Rai; D. V. Ramana; R. N. Singh

    1998-01-01

    An analytical solution of the linearized Boussinesq equation is developed to predict the formation of a ground-water mound in an aquifer system in response to localized time-varying recharge. The recharge is applied from a centrally located circular basin. The solution is obtained using an eigenvalue-eigenfunction method. The solution for a constant recharge rate is shown as a special case of

  7. The impact of intensive groundwater abstraction on recharge to a shallow regional aquifer system: evidence from Bangladesh

    Microsoft Academic Search

    Mohammad Shamsudduha; Richard G. Taylor; Kazi M. Ahmed; Anwar Zahid

    2011-01-01

    Quantitative evaluations of the impact of groundwater abstraction on recharge are rare. Over a period (1975–2007) during which\\u000a groundwater abstraction increased dramatically in the Bengal Basin, changes in net groundwater recharge in Bangladesh are\\u000a assessed using the water-table fluctuation method. Mean annual groundwater recharge is shown to be higher (300–600 mm) in\\u000a northwestern and southwestern areas of Bangladesh than in southeastern

  8. Dependency of hydrologic responses and recharge estimates on water-level monitoring locations within a small catchment

    Microsoft Academic Search

    Jin-Yong Lee; Myeong-Jae Yi; Daekyoo Hwang

    2005-01-01

    Estimation of groundwater recharge is essential for planning sustainable groundwater development. In this study, recharge\\u000a ratios were estimated using the groundwater hydrographs obtained from monitoring wells located in a small catchment (0.256\\u000a km2). The catchment area is a triangular alluvial plain bounded by gentle hills and a large stream. For the recharge estimation,\\u000a the modified water-table fluctuation (WTF) method was

  9. The character of organic carbon in recharge water and arsenic mobilization in Bangladesh aquifers

    NASA Astrophysics Data System (ADS)

    Pracht, L. E.; Fussell, A. H.; Polizzotto, M.; Badruzzaman, A. M.; Ali, M. A.; Neumann, R. B.

    2012-12-01

    In Bangladesh, arsenic-contaminated groundwater, used for both drinking and irrigation supplies, negatively affects the health of millions of people. Past work at our site in Munshiganj suggests that current patterns of arsenic concentration in the aquifer are related to groundwater flow and recharge chemistry. Constructed ponds and groundwater-irrigated rice fields serve as the primary aquifer recharge sources, with pond recharge evolving into high-arsenic groundwater and rice field recharge evolving into low-arsenic groundwater. The composition of these water types vary in concentrations and character of dissolved organic carbon, a presumed key component in the mechanism of arsenic release from sediments. Here we present results from an experiment-based laboratory study that directly tests the role of organic carbon character and bioavailability on arsenic mobilization. Incubation experiments using sediment samples collected from Bangladesh and waters with different carbon sources (e.g., pond and rice field recharge water and artificial water with model carbon compounds) were conducted to show the phase transformations carbon undergoes during arsenic mobilization processes, to isolate the carbon components and characteristics most responsible for mobilization reactions, and to investigate the importance of secondary chemical constituents for completion of these physiochemical reactions. Water, gas, and sediment samples collected from the incubations were analyzed for nutrient, metal, anion, and carbon concentrations, as well as carbon character. The results clarify the chemical components most critical in arsenic mobilization and provide insight into the in situ chemical reactions occurring in the aquifer. Moreover, this better chemical understanding helps elucidate the potential impact of altered recharge patterns and recharge chemistry on arsenic concentrations of Bangladeshi groundwater supplies.

  10. Recharge of valley-fill aquifers in the glaciated northeast from upland runoff

    USGS Publications Warehouse

    Williams, J.H.; Morrissey, D.J.

    1996-01-01

    Channeled and unchanneled runoff from till-covered bedrock uplands is a major source of recharge to valley-fill aquifers in the glaciated northeastern United States. Streamflow measurements and model simulation of average steady-state conditions indicate that upland runoff accounted for more recharge to two valley-fill aquifers in moderately high topographic-relief settings than did direct infiltration of precipitation. Recharge from upland runoff to a modeled valley-fill aquifer in an area of lower relief was significant but less than that from direct infiltration of precipitation. The amount of upland runoff available for recharging valley-fill aquifers in the glaciated Northeast ranges from about 1.5 to 2.5 cubic feet per second per square mile of drainage area that borders the aquifer. Stream losses from tributaries that drain the uplands commonly range from 0.3 to 1.5 cubic feet per second per 1,000 feet of wetted channel where the tributaries cross alluvial fans in the main valleys. Recharge of valley-fill aquifers from channeled runoff was estimated from measured losses and average runoff rates and was represented in aquifer models as specified fluxes or simulated by head-dependent fluxes with streamflow routing in the model cells that represent the tributary streams. Unchanneled upland runoff, which includes overland and subsurface flow, recharges the valley-fill aquifers at the contact between the aquifer and uplands near the base of the bordering till-covered hillslopes. Recharge from unchanneled runoff was estimated from average runoff rates and the hillslope area that borders the aquifer and was represented as specified fluxes to model-boundary cells along the valley walls.

  11. Borehole environmental tracers for evaluating net infiltration and recharge through desert bedrock

    USGS Publications Warehouse

    Heilweil, V.M.; Solomon, D.K.; Gardner, P.M.

    2006-01-01

    Permeable bedrock aquifers in arid regions are being increasingly developed as water supplies, yet little is generally known about recharge processes and spatial and temporal variability. Environmental tracers from boreholes were used in this study to investigate net infiltration and recharge to the fractured Navajo Sandstone aquifer. Vadose zone tracer profiles at the Sand Hollow study site in southwestern Utah look similar to those of desert soils at other sites, indicating the predominance of matrix flow. However, recharge rates are generally higher in the Navajo Sandstone than in unconsolidated soils in similar climates because the sandstone matrix allows water movement but not root penetration. Water enters the vadose zone either as direct infiltration of precipitation through exposed sandstone and sandy soils or as focused infiltration of runoff. Net infiltration and recharge exhibit extreme spatial variability. High-recharge borehole sites generally have large amounts of vadose zone tritium, low chloride concentrations, and small vadose zone oxygen-18 evaporative shifts. Annual net-infiltration and recharge rates at different locations range from about 1 to 60 mm as determined using vadose zone tritium, 0 to 15 mm using vadose zone chloride, and 3 to 60 mm using groundwater chloride. Environmental tracers indicate a cyclical net-infiltration and recharge pattern, with higher rates earlier in the Holocene and lower rates during the late Holocene, and a return to higher rates during recent decades associated with anomalously high precipitation during the latter part of the 20th century. The slightly enriched stable isotopic composition of modern groundwater indicates this recent increase in precipitation may be caused by a stronger summer monsoon or winter southern Pacific El Nin??o storm track. ?? Soil Science Society of America.

  12. Evaluation of drought impact on groundwater recharge rate using SWAT and Hydrus models on an agricultural island in western Japan

    NASA Astrophysics Data System (ADS)

    Jin, G.; Shimizu, Y.; Onodera, S.; Saito, M.; Matsumori, K.

    2015-06-01

    Clarifying the variations of groundwater recharge response to a changing non-stationary hydrological process is important for efficiently managing groundwater resources, particularly in regions with limited precipitation that face the risk of water shortage. However, the rate of aquifer recharge is difficult to evaluate in terms of large annual-variations and frequency of flood events. In our research, we attempt to simulate related groundwater recharge processes under variable climate conditions using the SWAT Model, and validate the groundwater recharge using the Hydrus Model. The results show that annual average groundwater recharge comprised approximately 33% of total precipitation, however, larger variation was found for groundwater recharge and surface runoff compared to evapotranspiration, which fluctuated with annual precipitation variations. The annual variation of groundwater resources is shown to be related to precipitation. In spatial variations, the upstream is the main surface water discharge area; the middle and downstream areas are the main groundwater recharge areas. Validation by the Hydrus Model shows that the estimated and simulated groundwater levels are consistent in our research area. The groundwater level shows a quick response to the groundwater recharge rate. The rainfall intensity had a great impact on the changes of the groundwater level. Consequently, it was estimated that large spatial and temporal variation of the groundwater recharge rate would be affected by precipitation uncertainty in future.

  13. Use of the water-table fluctuation method to identify and characterize discrete episodes of positive and zero recharge

    NASA Astrophysics Data System (ADS)

    Horowitz, C.; Nimmo, J. R.; Mitchell, L.

    2011-12-01

    As demand increases for limited water supplies, accurate estimates of groundwater recharge become more important from both a water supply and a water quality perspective. The water table fluctuation (WTF) method is often applied for this purpose. The principle of the WTF method is that recharge is equal to the product of specific yield and the water table rise over a particular time interval or episode. Previous research has demonstrated that recharge estimates based on the WTF method have strong sensitivity to the length of the designated time interval. We have developed a method of choosing time intervals for WTF recharge analysis based on intensity and duration of recharge events, correlating specific events with the rainfall that initiated them. In the absence of recharge, the rate of water-table recession can be taken to have a direct functional relationship with the water-table elevation (H). This relationship is referred to as a master recession curve (MRC). A robust MRC (i.e., one that is accurate over the relevant range of H) is essential for accurate WTF-based estimates of groundwater recharge. Where there is a high degree of subsurface heterogeneity, a simple functional form of the MRC (e.g., one based on the concept of a single pour point) may not accurately represent actual conditions. In a numerical algorithm for determining an MRC, we incorporated consistent criteria which allow the MRC to be based only on data representing receding water-tables during periods of negligible recharge. Another algorithm was created to utilize that MRC in estimations of recharge in an episodic fashion, based on a systematic designation of events, i.e. intervals of recharge and their associated rainfall and intervals of zero recharge, also with associated rainfall. We tested these methods using a data set exhibiting rapid water-table fluctuations at the Masser Site in Pennsylvania. The aquifer medium is a highly fractured sandstone with a small specific yield (0.001 < Sy < 0.013). The depth to the water table is 5-15 m and water level responses to intense rainfall typically occur within several hours. Our method partitions the continuous times series into discrete recharge and non-recharge episodes. Results show that high-intensity precipitation events produce increased recharge to precipitation recharge ratios. Thus, the method has value for predicting how increases in storm intensity resulting from climate change may increase the overall recharge to precipitation ratio.

  14. The Significance of Accounting Order for Evapotranspiration and Recharge in Monthly and Daily Threshold-Type Water Budgets

    USGS Publications Warehouse

    Oki, Delwyn S.

    2008-01-01

    Most threshold-type water-budget models account for the loss of water by evapotranspiration before accounting for recharge. Recharge estimates can differ substantially, depending on whether recharge is counted before or after evapotranspiration in the water budget. This disparity is the source of uncertainty and is most pronounced for areas where soil-moisture storage capacity is small or for water budgets computed using a large time interval (such as monthly). Water budgets that account for recharge before evapotranspiration provide higher estimates of recharge and lower estimates of evapotranspiration relative to water budgets that account for evapotranspiration before recharge. The choice of accounting method is less significant for a daily computation interval than for a monthly computation interval. In general, uncertainty in recharge estimates is least for water budgets computed using the shortest computation interval that the data allow and that is consistent with the physical processes being represented. If the data only allow for long (weekly or monthly) computation intervals, then selecting the appropriate accounting order for the study area may be critical. For monthly water budgets, accounting for recharge before evapotranspiration is most appropriate in areas where rainfall occurs infrequently, whereas accounting for evapotranspiration before recharge is most appropriate where rainfall occurs relatively uniformly throughout the month.

  15. Current Status of the Nitrogen Oxygen Recharge System

    NASA Technical Reports Server (NTRS)

    Dick, Brandon

    2011-01-01

    This paper presents an overview of the Nitrogen Oxygen Recharge System (NORS) to date and the current development status of the system. NORS is an element of the International Space Station (ISS) Environmental Control and Life Support Systems (ECLSS) used to resupply the ISS with Nitrogen and Oxygen following the impending retirement of the Space Shuttle. The paper will discuss why NASA is developing NORS, including a summary of other concepts considered, and other related concepts currently being developed by NASA. The current system architecture will be described, along with a summary of the current design of the NORS. The overall programmatic schedule of the NORS in the context of the upcoming shuttle retirement and future launch vehicle development will also be presented. Finally, the paper will examine the significant technical challenges encountered during the requirements and preliminary design phase of NORS development. A key challenge to the development of NORS is the international shipment - and associated regulations - of pressurized Oxygen, which is necessary due to the use of launch vehicles based in Japan and French Guiana to send NORS gasses to the ISS. The storage and use of relatively large quantities of high pressure (41,000 kPa) Oxygen and Nitrogen within the ISS, which is unprecedented both on the ISS and other space vehicles, has had a significant impact on the design and architecture of the system. The high pressure of the system also poses unique thermal considerations, which has led to the development of a heater system for thermal conditioning of high pressure gas to avoid thermal impacts on downstream hardware. The on-orbit envelope allocated to the NORS has changed (gotten smaller) and has impacted both the design and architecture of the system. Finally, the balance of safety considerations associated with these high pressure gasses, particularly high pressure Oxygen, with the functionality of the system has profoundly impacted the form of the system and will be discussed.

  16. Lithium-Ion rechargeable batteries on Mars Rover

    NASA Technical Reports Server (NTRS)

    Ratnakumar, B. V.; Smart, M. C.; Ewell, R. C.; Whitcanack, L. D.; Chin, K. B.; Surampudi, S.

    2004-01-01

    NASA's Mars Rovers, Spirit and Opportunity, have been roving on the surface of Mars, capturing impressive images of its terrain and analyzing the drillings from Martian rocks, to answer the ever -puzzling questions of life beyond Earth and origin of our planets. These rovers are being enabled by an advanced rechargeable battery system, lithium-ion, for the first time on a space mission of this scale, for keeping the rover electronics warm, and for supporting nighttime experimentation and communications. These rover Li-ion batteries are characterized by their unique low temperature capability, in addition to the usual advantages associated with Li-ion chemistry in terms of mass, volume and energy efficiency. To enable a rapid insertion of this advanced Li-ion chemistry into flight missions, we have performed several performance assessment studies on several prototype cells over the last few years. These tests mainly focused primarily on the long-term performance characteristics, such as cycling and storage, as described in our companion paper. In addition, various tests have been performed on MER cells and engineering and proto flight batteries; under conditions relevant to these missions. For example, we have examined the performance of the cells in: a) an inverted orientation, as during integration and launch, and b) conditions of low rate discharge, between 3.0-2.5 V to support the mission clock. Likewise, we have determined the impedance of the proto-flight Rover battery assembly unit in detail, with a view to asses whether a current-limiting resistor would be unduly stressed, in the event of a shorting induced by a failed pyro. In this paper we will describe these studies in detail, as well as the performance of Li-ion batteries in Spirit and Opportunity rovers, during cruise and on Mars.

  17. A rigorous method for quantifying recharge using simple and complex models

    NASA Astrophysics Data System (ADS)

    Ireson, A. M.; Butler, A. P.

    2012-04-01

    One of the fundamental challenges for quantifying the timing and magnitude of groundwater recharge is that there remains no direct, non-destructive method for measuring this flux. As a result, recharge is indirectly inferred, requiring a conceptual model (that is a set of assumptions about the system processes), a mathematical model (providing quantitative estimates) and some indirect observations. For physical approaches, observations will typically include rainfall, potential evaporation and either soil/unsaturated moisture status, or water table fluctuations. Some limitations with conventional modelling approaches include: inadequate representation of the deep unsaturated zone; inadequate representation of unsaturated zone-saturated zone interactions (for example, changing unsaturated zone thickness in areas where water table fluctuations are significant); inadequate representation of lateral flows within the saturated zone which influence water table fluctuations (an example being the erroneous assumption that a sustained failing water table is indicative of an absence of recharge). In groundwater models, errors in recharge estimates may be masked by calibration of the saturated zone parameters (specific yield and hydraulic conductivity). Validation of the modelled recharge is therefore not rigorous. This paper presents a detailed physically based model for unsaturated-saturated zone flow processes applied to a dual permeability Chalk hillslope transect. This is a fairly well constrained natural field site in a highly studied catchment. The Chalk is a complex fractured porous medium. A detailed model based on Richards' equation explicitly simulates the (observable) water table response to recharge, with none of the limitations listed above. This model is able to reproduce observed field behaviour. This provides us with a benchmark with which to test conventional recharge models in a more rigorous manner than has been done previously. In particular we focus on testing a standard recharge model involving a soil moisture deficit concept (i.e. a storage-discharge threshold) and simple bypass, which has been applied in numerous groundwater models of Chalk systems. Overall, the very simple model is surprisingly effective at reproducing the behaviour of the complex detailed model, and in particular the strength of the storage-discharge threshold concept, used in many recharge models, is emphasized. However, the analysis also indicates that conventional Chalk recharge models provide the right answer for the wrong reason. Specifically, slow drainage from the Chalk unsaturated zone during the summer months, simulated by the detailed model, is not simulated by the simple model, but bypass recharge during the summer, when accumulated onto monthly timesteps, compensates for this. This could lead to a marked underestimation of Chalk recharge during severe droughts. In addition, whilst bypass flow in Chalk is well established (e.g. Ireson and Butler, 2011), these results indicate that the current modelling approach, which ignores rainfall amount and antecedent conditions, is a gross simplification of this complex process. Ireson, A.M. and Butler A.P. Controls on preferential recharge to Chalk aquifers. Journal of Hydrology (2011), 398, 109-123, doi:10.1016/j.jhydrol.2010.12.015.

  18. Estimation of recharge rates to the sand and gravel aquifer using environmental tritium, Nantucket Island, Massachusetts

    USGS Publications Warehouse

    Knott, Jayne Fifield; Olimpio, Julio C.

    1986-01-01

    Estimation of the average annual rate of ground-water recharge to sand and gravel aquifers using elevated tritium concentrations in ground water is an alternative to traditional steady-state and water-balance recharge-rate methods. The concept of the tritium tracer method is that the average annual rate of ground-water recharge over a period of time can be calculated from the depth of the peak tritium concentration in the aquifer. Assuming that ground-water flow is vertically downward and that aquifer properties are reasonably homogeneous, and knowing the date of maximum tritium concentration in precipitation and the current depth to the tritium peak from the water table, the average recharge rate can be calculated. The method, which is a direct-measurement technique, was applied at two sites on Nantucket Island, Massachusetts. At site 1, the average annual recharge rate between 1964 and 1983 was 26.1 inches per year, or 68 percent of the average annual precipitation, and the estimated uncertainty is ?15 percent. At site 2, the multilevel water samplers were not constructed deep enough to determine the peak concentration of tritium in ground water. The tritium profile at site 2 resembles the upper part of the tritium profile at site 1 and indicates that the average recharge rate was at least 16 .7 inches per year, or at least 44 percent of the average annual precipitation. The Nantucket tritium recharge rates clearly are higher than rates determined elsewhere in southeastern Massachusetts using the tritium, water-table-fluctuation, and water-balance (Thornthwaite) methods, regardless of the method or the area. Because the recharge potential on Nantucket is so high (runoff is only 2 percent of the total water balance), the tritium recharge rates probably represent the effective upper limit for ground-water recharge in this region. The recharge-rate values used by Guswa and LeBlanc (1985) and LeBlanc (1984) in their ground-water-flow computer models of Cape Cod are 20 to 30 percent lower than this upper limit. The accuracy of the tritium method is dependent on two key factors: the accuracy of the effective-porosity data, and the sampling interval used at the site. For some sites, the need for recharge-rate data may require a determination as statistically accurate as that which can be provided by the tritium method. However, the tritium method is more costly and more time consuming than the other methods because numerous wells must be drilled and installed and because many water samples must be analyzed for tritium, to a very small level of analytical detection. For many sites, a less accurate, less expensive, and faster method of recharge-rate determination might be more satisfactory . The factor that most seriously limits the usefulness of the tritium tracer method is the current depth of the tritium peak. Water with peak concentrations of tritium entered the ground more than 20 years ago, and, according to the Nantucket data, that water now is more than 100 feet below the land surface. This suggests that the tracer method will work only in sand and gravel aquifers that are exceedingly thick by New England standards. Conversely, the results suggest that the method may work in areas where saturated thicknesses are less than 100 feet and the rate of vertical ground-water movement is relatively slow, such as in till and in silt- and clay-rich sand and gravel deposits.

  19. Simulation of recharge for the Death Valley regional groundwater flow system using an integrated hydrologic model

    NASA Astrophysics Data System (ADS)

    Hevesi, J. A.; Regan, R. S.; Hill, M. C.; Heywood, C.; Kohn, M. S.

    2012-12-01

    A proof-of-concept study was conducted using the integrated hydrologic model, GSFLOW, to simulate spatially and temporally distributed recharge for the Death Valley regional groundwater flow system (DVRFS). GSFLOW is an integrated groundwater - surface water flow model that combines two modeling applications: the Precipitation-Runoff-Modeling-System (PRMS) and MODFLOW. Previous methods used to estimate recharge for the DVRFS include empirical models based on precipitation, applications of the chloride mass-balance method, and applications of a precipitation-runoff model, INFIL, which used a daily time step to simulate recharge as net infiltration through the root zone. The GSFLOW model offers several potential advantages compared to the previous methods including (1) the ability to simulate complex flow through a thick unsaturated zone (UZ), allowing for the dampening and time delay of recharge relative to the infiltration signal at the top of the UZ and also allowing for the redistribution of flow within the UZ, as enabled by the MODFLOW-NWT and UZF capabilities, (2) the simulation of rejected recharge in response to the dynamics of groundwater discharge and low permeability zones in the UZ, (3) a more explicit representation of streamflow and recharge processes in the mostly ephemeral stream channels that characterize the DVRFS, and (4) the ability to simulate complex flow paths for runoff occurring as both overland flow and shallow subsurface flow (interflow) in the soil zone using a network of cascades connecting hydrologic response units (HRUs). Simulations were done using a daily time step for water years 1980-2010. Preliminary estimates of recharge using GSFLOW indicate that the distribution of recharge is highly variable both spatially and temporally due to variability in precipitation, snowmelt, evapotranspiration, runoff, and the permeability of bedrock and alluvium underlying the root zone. Results averaged over the areas of subbasins were similar to results obtained from previous studies. However, estimates of recharge on the local scale of the HRUs indicate significant (greater than 100 percent) differences at some locations compared to results obtained using INFIL due to differences in (1) the geometry and scale of HRUs, (2) the layout of the cascading flow network and the location of stream channels, (3) the representation of the physical characteristics of the root zone, and (4) model processes controlling the simulation of evapotranspiration and the movement of water through the root zone.

  20. Effects of Climate Extremes on the Groundwater Recharge of the Ogallala Aquifer, USA 1950-1999

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Felzer, B. S.

    2014-12-01

    Climate extremes have and will continue to cause significant variations of local and regional groundwater hydrology. It is important to understand the effects of climate extremes on groundwater recharge to properly manage water resources. Using the Soil Water Balance Model (SWB) and Maurer's 1/8-degree daily climatology datasets, this study investigates the dynamics of groundwater recharge of the Ogallala Aquifer in the second half of the 20th century relative to trends of two temperature and six precipitation extreme indices, including consecutive dry days (CDD), consecutive wet days (CWD), heavy precipitation days (ND95), annual total precipitation from heavy precipitation events (TP95), annual total precipitation from wet days (PRCPTOT), annual maximum 5-day precipitation (RX5), annual hot days (TX90) and annual hot nights (TN90). The results show that the highest recharge was about 110 mm yr-1 in eastern Nebraska, followed by central Nebraska and western Kansas, with recharge values of 45 mm yr-1. The range of recharge for the rest of the aquifer area was 0-20 mm yr-1. Temporally, the overall groundwater recharge significantly (p<0.05) increased throughout the Ogallala Aquifer. Spatially, groundwater recharge significantly increased in central Nebraska, eastern Wyoming and parts of northern Texas, while it decreased from southwestern Nebraska to the northern boundary of Texas. The study area experienced enhanced temperature and precipitation extremes over the 50 year period. The changing trends of hot temperatures were not spatially uniform: increasing hot days occurred in the northwestern Ogallala, parts of the central Ogallala, and the entire southern Ogallala; while decreasing hot nights occurred in the northeastern, central, and southern Ogallala. Increases in trends of precipitation extremes were more spatially uniform. Based on spatial non-parameter correlation analysis, increasing precipitation extremes may decrease groundwater recharge in regions with less annual total precipitation, but may increase groundwater recharge in regions with sufficient precipitation. Therefore, policy-makers need to be aware of the temporal and spatial heterogeneity of extreme precipitation events, especially in arid regions.

  1. Alternative aircraft fuels

    NASA Technical Reports Server (NTRS)

    Longwell, J. P.; Grobman, J.

    1978-01-01

    In connection with the anticipated impossibility to provide on a long-term basis liquid fuels derived from petroleum, an investigation has been conducted with the objective to assess the suitability of jet fuels made from oil shale and coal and to develop a data base which will allow optimization of future fuel characteristics, taking energy efficiency of manufacture and the tradeoffs in aircraft and engine design into account. The properties of future aviation fuels are examined and proposed solutions to problems of alternative fuels are discussed. Attention is given to the refining of jet fuel to current specifications, the control of fuel thermal stability, and combustor technology for use of broad specification fuels. The first solution is to continue to develop the necessary technology at the refinery to produce specification jet fuels regardless of the crude source.

  2. Regional assessment of Groundwater Recharge and Water Harvesting potential in semi-arid lands.

    NASA Astrophysics Data System (ADS)

    Fleskens, L.; Kirkby, M. J.

    2012-04-01

    Water balance calculations based on gridded monthly climate data offer a tool for partitioning available precipitation between surface runoff, soil water storage, evapotranspiration and recharge to groundwater. Using a dynamic model in which vegetation biomass and soil organic matter also respond to the availability of water, we can distinguish regional patterns of hydrological regimes along the spectrum from humid to arid conditions.. Groundwater recharge is at its most significant when precipitation is of the same order as potential evapotranspiration. In arid climates, most water is lost to evapotranspiration through vertical exchanges, allowing little storage of soil water and significant recharge only in large events and primarily along channelways. In humid climates, most of the precipitation drains laterally in the shallow subsurface, so that although groundwater recharge increases absolutely with precipitation, it decreases as a proportion of the total, and therefore lessens the importance of groundwater as a resource. The benefits of water harvesting are most achievable where rainfall is marginally inadequate for rainfed agriculture, allowing supplementation by harvesting of surface runoff or groundwater, preferably from renewable sources. The reliability of harvesting methods also depends strongly on the inter-annual variability of rainfall, which generally increases towards more arid regions, providing an additional constraint on the sustainability of harvesting systems. These principles are exemplified by maps for Europe and Africa, generated by the model from the climatic data and showing the broad regional patterns of recharge and water harvesting potential.

  3. Recharge Data Package for Hanford Single-Shell Tank Waste Management Areas

    SciTech Connect

    Fayer, Michael J.; Keller, Jason M.

    2007-09-24

    Pacific Northwest National Laboratory (PNNL) assists CH2M HILL Hanford Group, Inc., in its preparation of the Resource Conservation and Recovery Act (RCRA) Facility Investigation report. One of the PNNL tasks is to use existing information to estimate recharge rates for past and current conditions as well as future scenarios involving cleanup and closure of tank farms. The existing information includes recharge-relevant data collected during activities associated with a host of projects, including those of RCRA, the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the CH2M HILL Tank Farm Vadose Zone Project, and the PNNL Remediation and Closure Science Project. As new information is published, the report contents can be updated. The objective of this data package was to use published data to provide recharge estimates for the scenarios being considered in the RCRA Facility Investigation. Recharge rates were estimated for areas that remain natural and undisturbed, areas where the vegetation has been disturbed, areas where both the vegetation and the soil have been disturbed, and areas that are engineered (e.g., surface barrier). The recharge estimates supplement the estimates provided by PNNL researchers in 2006 for the Hanford Site using additional field measurements and model analysis using weather data through 2006.

  4. Estimating 1970-99 average annual groundwater recharge in Wisconsin using streamflow data

    USGS Publications Warehouse

    Gebert, Warren A.; Walker, John F.; Kennedy, James L.

    2011-01-01

    Average annual recharge in Wisconsin for the period 1970-99 was estimated using streamflow data from U.S. Geological Survey continuous-record streamflow-gaging stations and partial-record sites. Partial-record sites have discharge measurements collected during low-flow conditions. The average annual base flow of a stream divided by the drainage area is a good approximation of the recharge rate; therefore, once average annual base flow is determined recharge can be calculated. Estimates of recharge for nearly 72 percent of the surface area of the State are provided. The results illustrate substantial spatial variability of recharge across the State, ranging from less than 1 inch to more than 12 inches per year. The average basin size for partial-record sites (50 square miles) was less than the average basin size for the gaging stations (305 square miles). Including results for smaller basins reveals a spatial variability that otherwise would be smoothed out using only estimates for larger basins. An error analysis indicates that the techniques used provide base flow estimates with standard errors ranging from 5.4 to 14 percent.

  5. Tritium as an indicator of recharge and dispersion in a groundwater system in central Ontario

    NASA Astrophysics Data System (ADS)

    Robertson, W. D.; Cherry, J. A.

    1989-06-01

    The detailed distribution of tritium (3H) in the recharge area of a shallow unconfined sand aquifer near Sturgeon Falls, Ontario, is described. At this forested, shallow water table site, bomb tritium has penetrated uniformly to a depth of 8-12 m indicating recharge of 15 cm/year, which is 16% of precipitation. The zone of bomb tritium contains 3H concentrations of from 16 to 269 tritium unit (TU), whereas much lower values (<1 TU) are observed in groundwaters recharged only a few years prior to 1953, the year when significant fallout of bomb tritium began. Tritium distribution is accurately simulated, using one- and two-dimensional models, when the Ottawa record is used for the post-1953 tritium input function, when dispersion is low and when a prebomb tritium input value of 3 TU is used. This prebomb value is slightly lower than that suggested by Kaufman and Libby (1954), based on precipitation and surface water samples from the early 1950s. The simulations indicate and field data corroborate, that in 1986, 3H levels of more than 100 TU occur only in groundwaters recharged between 1957 and 1971, while levels in excess of 200 TU occur only in groundwaters recharged during 1961-1967. The 1960s tritium peak is observed within a narrow distinct depth zone at all locations along the flow section investigated.

  6. On Evaluation of Recharge Model Uncertainty: a Priori and a Posteriori

    SciTech Connect

    Ming Ye; Karl Pohlmann; Jenny Chapman; David Shafer

    2006-01-30

    Hydrologic environments are open and complex, rendering them prone to multiple interpretations and mathematical descriptions. Hydrologic analyses typically rely on a single conceptual-mathematical model, which ignores conceptual model uncertainty and may result in bias in predictions and under-estimation of predictive uncertainty. This study is to assess conceptual model uncertainty residing in five recharge models developed to date by different researchers based on different theories for Nevada and Death Valley area, CA. A recently developed statistical method, Maximum Likelihood Bayesian Model Averaging (MLBMA), is utilized for this analysis. In a Bayesian framework, the recharge model uncertainty is assessed, a priori, using expert judgments collected through an expert elicitation in the form of prior probabilities of the models. The uncertainty is then evaluated, a posteriori, by updating the prior probabilities to estimate posterior model probability. The updating is conducted through maximum likelihood inverse modeling by calibrating the Death Valley Regional Flow System (DVRFS) model corresponding to each recharge model against observations of head and flow. Calibration results of DVRFS for the five recharge models are used to estimate three information criteria (AIC, BIC, and KIC) used to rank and discriminate these models. Posterior probabilities of the five recharge models, evaluated using KIC, are used as weights to average head predictions, which gives posterior mean and variance. The posterior quantities incorporate both parametric and conceptual model uncertainties.

  7. Attenuation capacity of a coastal aquifer under managed recharge by reclaimed wastewater

    NASA Astrophysics Data System (ADS)

    Christodoulou, George; Dokou, Zoi; Tzoraki, Ourania; Gaganis, Petros; Karatzas, George

    2013-08-01

    Managed Aquifer Recharge (MAR) is becoming an increasingly attractive water management option, especially in semiarid areas. Nevertheless, field studies on the fate and transport of priority substances, heavy metals and pharmaceutical products within the recharged aquifer are rare. Based on the above, the objective of this project is to study the hydrological conditions of the coastal aquifer of Ezousa (Cyprus) and its ability to attenuate pollutants. The Ezousa riverbed is a locally important aquifer used for a MAR project where treated effluent from the Paphos Waste Water Treatment Plant is recharged into the aquifer through a number of artificial ponds along the riverbed. Additionally, groundwater is pumped for irrigation purposes from wells located nearby. The hydrological conditions of the area are unique due to the construction of the Kannaviou dam in 2005 that reduced natural recharge of the Ezousa aquifer significantly, inducing the saltwater intrusion phenomenon. A three-dimensional finite element model of the area was constructed using the FEFLOW software to simulate the groundwater flow conditions and transport of Phosphorous and cooper in the subsurface from the recharge process. The model was calibrated using hydraulic head and chemical data for the time period of 2002-2011. The groundwater model was coupled with a geochemical model PHREEQC attempting to evaluate nitrate and Copper processes. Inverse modeling calculation was used to determine sets of moles transfers of phases that are attributed to the water composition change in groundwater between the mixture of natural groundwater and reclaimed wastewater and the final water composition.

  8. Evaluation of noble gas recharge temperatures in a shallow unconfined aquifer.

    PubMed

    Cey, Bradley D; Hudson, G Bryant; Moran, Jean E; Scanlon, Bridget R

    2009-01-01

    Water table temperatures inferred from dissolved noble gas concentrations (noble gas temperatures, NGT) are useful as a quantitative proxy for air temperature change since the last glacial maximum. Despite their importance in paleoclimate research, few studies have investigated the relationship between NGT and actual recharge temperatures in field settings. This study presents dissolved noble gas data from a shallow unconfined aquifer heavily impacted by agriculture. Considering samples unaffected by degassing, NGT calculated from common physically based interpretive gas dissolution models that correct measured noble gas concentrations for "excess air" agreed with measured water table temperatures (WTT). The ability to fit data to multiple interpretive models indicates that model goodness-of-fit does not necessarily mean that the model reflects actual gas dissolution processes. Although NGT are useful in that they reflect WTT, caution is recommended when using these interpretive models. There was no measurable difference in excess air characteristics (amount and degree of fractionation) between two recharge regimes studied (higher flux recharge primarily during spring and summer vs. continuous, low flux recharge). Approximately 20% of samples had dissolved gas concentrations below equilibrium concentration with respect to atmospheric pressure, indicating degassing. Geochemical and dissolved gas data indicate that saturated zone denitrification caused degassing by gas stripping. Modeling indicates that minor degassing (<10% DeltaNe) may cause underestimation of ground water recharge temperature by up to 2 degrees C. Such errors are problematic because degassing may not be apparent and degassed samples may be fit by a model with a high degree of certainty. PMID:19735308

  9. Does Tritium Counts Help Quantify Residence Time of Recharge Waters Today?

    NASA Astrophysics Data System (ADS)

    Damtew, A. D.; Wohnlich, S.

    2014-12-01

    Concentration of tritium in waters sampled from cold, warm, and thermal sources contained in shallow and deep aquifers, and springs were analyzed to characterize and model the residence time of recharge waters in fractured, unconsolidated, and recent volcano-clastic aquifers in the southwestern part of the Main Ethiopian Rift System. The measured tritium concentrations were interpreted (i) with reference to historical records at three nearby GNIP (Global Network of Isotopes in Precipitation) stations in Ethiopia, (ii) in conjunction with hydrochemical variables that can imply residence time of water in aquifer formations and unsaturated layers, and (iii) in association with some of the major basin attributes that could potentially influence on the process of natural recharge, hence, age of aquifer waters. The measured tritium counts in 102 water samples generally fall between 2.5 and 4 TU. Measurements portrayed no spatial patterns and defined relations with variables including concentration of chloride, molar ratios of Mg2+ to Ca2+ and Na+ to Cl-, NO3-, electrical conductivity, dissolved oxygen, chemical water types, fracture density, static water level, depth to water table, depth of well, depth of precipitation, degree of aridity, drainage density, and surface slope. This study shows the limited application of tritium to quantify the residence time of recharge waters and conceptualize the mechanism of recharge in the study area. Keywords: Tritium, residence time, recharge, Main Ethiopian Rift

  10. Groundwater recharge estimation from ephemeral streams. Case study: Wadi Tabalah, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Sorman, Ali U.; Abdulrazzak, Mohamed J.; Morel-Seytoux, H. J.

    1997-10-01

    Estimation of groundwater recharge to an unconfined aquifer is studied using analytical and numerical techniques and results are compared with field observations. There is an acute need for such estimation in water balance studies in arid climates, and the case study in this paper is for such a region. The wetting front movement in the unsaturated zone depends on antecedent soil moisture, the ponded water depth and its duration, and on the position of the water table and the hydraulic properties of the unsaturated zone. A hydraulic connection between the recharge basin and the aquifer is not immediately established because the wetting front is unsaturated.A numerical model is applied to estimate recharge in an arid-zone wadi, and its validity is tested by comparing it with an analytical solution of the equations. The calculated recharge values matched the piezometric levels observed at a well site at the edge of the wadi channel. The total recharge depths found by integration in the time domain provided a good estimate of the transmitted volume of water per unit length of wadi channel. The findings were confirmed by runoff volume measurements at gauging stations located in the basin.

  11. Potential Groundwater Recharge from the Infiltration of Surface Runoff in Cold and Dry Creeks, Phase 2

    SciTech Connect

    Waichler, Scott R.

    2005-12-13

    Runoff from Cold and Dry Creeks may provide an important source of groundwater recharge on the Hanford Site. This report presents estimates of total volume and distribution of such recharge from extreme precipitation events. Estimates were derived using a simple approach that combined the Soil Conservation Service curve number runoff method and an exponential-decay channel infiltration model. Fifteen-minute streamflow data from four gaging stations, and hourly precipitation data from one climate station, were used to compute curve numbers and calibrate the infiltration model. All data were from several storms occurring during January 1995. Design storm precipitation depths ranging from 1.6 to 2.7 inches were applied with computed curve numbers to produce total runoff/recharge of 7,700 to 15,900 ac-ft, or approximately 10 times the average annual rate from this recharge source as determined in a previous study. Approximately two-thirds of the simulated recharge occurred in the lower stream reaches contained in the broad alluvial valley that parallels State Highway 240 near the Hanford 200 Area.

  12. Ground water recharge in the High Plains states; and delivery of water to the North Platte irrigation project. Part 2. Hearing before the Subcommittee on Water and Power, United States Senate, Ninety-Eighth Congress, Second Session on S. 1811 and H. R. 71, February 17, 1984

    SciTech Connect

    Not Available

    1984-01-01

    Part 2 of the hearing record covers testimony given in Woodward, Oklahoma by local residents and representatives of consumer groups and water resource planners and agencies on opportunities for ground water recharge in western Oklahoma. At issue was legislation (S. 1811 and H.R. 71) calling for a special comprehensive study on western ground water recharge and development, and which would serve as a basis for demonstration projects. The witnesses described existing reclamation projects, the problems of ground water depletion due to irrigation activities, the characteristics of the Ogallala aquifer, and other aspects of the proposal. Additional material submitted for the record follows the testimony of 23 witnesses.

  13. An improved time series approach for estimating groundwater recharge from groundwater level fluctuations

    NASA Astrophysics Data System (ADS)

    Cuthbert, M. O.

    2010-09-01

    An analytical solution to a linearized Boussinesq equation is extended to develop an expression for groundwater drainage using estimations of aquifer parameters. This is then used to develop an improved water table fluctuation (WTF) technique for estimating groundwater recharge. The resulting method extends the standard WTF technique by making it applicable, as long as aquifer properties for the area are relatively well known, in areas with smoothly varying water tables and is not reliant on precipitation data. The method is validated against numerical simulations and a case study from a catchment where recharge is "known" a priori using other means. The approach may also be inverted to provide initial estimates of aquifer parameters in areas where recharge can be reliably estimated by other methods.

  14. The feasibility of recharge rate determinations using the steady- state centrifuge method

    USGS Publications Warehouse

    Nimmo, J.R.; Stonestrom, D.A.; Akstin, K.C.

    1994-01-01

    The establishment of steady unsaturated flow in a centrifuge permits accurate measurement of small values of hydraulic conductivity (K). This method can provide a recharge determination if it is applied to an unsaturated core sample from a depth at which gravity alone drives the flow. A K value determined at the in situ water content indicates the long-term average recharge rate at a point. Tests of this approach have been made at two sites. For sandy core samples a better knowledge of the matric pressure profiles is required before a recharge rate can be determined. Fine-textured cores required new developments of apparatus and procedures, especially for making centrifuge measurements with minimal compaction of the samples. -from Authors

  15. Estimating groundwater recharge using an integrated surface and groundwater modelling approach

    NASA Astrophysics Data System (ADS)

    Chiew, F. H. S.; McMahon, T. A.; O'Neill, I. C.

    1992-02-01

    This paper describes the use of an integrated surface and groundwater modelling approach to estimate regional groundwater recharge rates. The daily version of the Monash Rainfall-Runoff Model, HYDROLOG, was adapted to represent the surface hydrological processes and the finite-element groundwater model, AQUIFEM-N, used to model the groundwater flow. The integrated model was calibrated against streamflow and potentiometric head data, with recharge estimated as an output from the calibrated model. The model was applied to both the irrigated and non-irrigated areas in the northern half of the Campaspe River Basin in north-central Victoria, Australia. The integrated model utilises the important features of the surface and groundwater models. It is useful in evaluating water resource development through better management of the conjunctive use of surface and ground water, and is an important tool in any predictive recharge study.

  16. Apparatus and method for recharging a string a avalanche transistors within a pulse generator

    DOEpatents

    Fulkerson, E. Stephen (Livermore, CA)

    2000-01-01

    An apparatus and method for recharging a string of avalanche transistors within a pulse generator is disclosed. A plurality of amplification stages are connected in series. Each stage includes an avalanche transistor and a capacitor. A trigger signal, causes the apparatus to generate a very high voltage pulse of a very brief duration which discharges the capacitors. Charge resistors inject current into the string of avalanche transistors at various points, recharging the capacitors. The method of the present invention includes the steps of supplying current to charge resistors from a power supply; using the charge resistors to charge capacitors connected to a set of serially connected avalanche transistors; triggering the avalanche transistors; generating a high-voltage pulse from the charge stored in the capacitors; and recharging the capacitors through the charge resistors.

  17. Impacts of urbanization on groundwater quality and recharge in a semi-arid alluvial basin

    NASA Astrophysics Data System (ADS)

    Carlson, Mark A.; Lohse, Kathleen A.; McIntosh, Jennifer C.; McLain, Jean E. T.

    2011-10-01

    SummaryThe management of groundwater resources is paramount in semi-arid regions experiencing urban development. In the southwestern United States, enhancing recharge of urban storm runoff has been identified as a strategy for augmenting groundwater resources. An understanding of how urbanization may impact the timing of groundwater recharge and its quality is a prerequisite for mitigating water scarcity and identifying vulnerability to contamination. We sampled groundwater wells along the Rillito Creek in southern Arizona that had been previously analyzed for tritium in the late 1980s to early 1990s and analyzed samples for tritium ( 3H) and helium-3 ( 3H/ 3He) to evaluate changes in 3H and age date groundwaters. Groundwater samples were also analyzed for chlorofluorocarbons (CFCs) and basic water quality metrics. Substantial changes in 3H values from waters sampled in the early 1990s compared to 2009 were identified after accounting for radioactive decay and indicate areas of rapid recharge. 3H- 3He groundwater ages ranged from 22 years before 2009 to modern recharge. CFC-11, -12 and -113 concentrations were anomalously high across the basin, and non-point source pollution in runoff and/or leaky infrastructure was identified as the most plausible source of this contamination. CFCs were strongly and positively correlated to nitrate ( r2 = 0.77) and a mobile trace metal, nickel ( r2 = 0.71), suggesting that solutes were derived from a similar source. Findings from this study suggest new waters from urban non-point sources are contributing to groundwater recharge and adversely affecting water quality. Reducing delivery of contaminants to areas of focused recharge will be critical to protect future groundwater resources.

  18. Estimating recharge distribution using remote sensing: A case study from the West Bank

    NASA Astrophysics Data System (ADS)

    Khalaf, Adla; Donoghue, Daniel

    2012-01-01

    SummaryEstimating groundwater recharge to the aquifer system is a very important element in assessing the water resources in regions of the world with poorly developed hydrological measurement stations such as the West Bank. Previous studies have developed analytical recharge models that are based on the long-term annual rainfall data. These models have been shown to be inadequate and changes over shorter periods, e.g. monthly estimates, must be known in order to study the temporal distribution of recharge. The approach used in this research integrates data derived from satellite images (e.g. land cover, evapotranspiration, precipitation, and digital elevation model) with hydrogeological data in a Geographic Information System (GIS) model to identify surface recharge areas on a pixel-by-pixel basis. The Surface Energy Balance Algorithm for Land (SEBAL) is applied to time series of MODerate Resolution Imaging Spectroradiometer (MODIS) Level 3 data of reflectance and surface temperature measurements to estimate monthly evapotranspiration; precipitation is derived from the monthly data sets of the Tropical Rainfall Measuring Mission (TRMM); runoff is given assumed values of 1.0 mm month -1 and 0.5 mm month -1 for the months of January and February, respectively. Recharge is quantified from November until March by applying the water balance method where evapotranspiration estimates and runoff are subtracted from precipitation. Results show good agreement between available numbers reported in literature and the remote sensing-based analysis. Empirical models that are based on long term rainfall measurements result values between 800 and 836 MCM yr -1 while the remote sensing based model results a recharge estimate of between 650 and 750 MCM yr -1.

  19. Recharge and source-water insights from the Galapagos Islands using noble gases and stable isotopes

    NASA Astrophysics Data System (ADS)

    Warrier, Rohit B.; Castro, Maria Clara; Hall, Chris M.

    2012-03-01

    Through a combined noble gas and stable isotope study carried out in the Galapagos Islands of Santa Cruz and San Cristobal, we demonstrate the utility of atmospheric noble gases in identifying recharge areas and timing of recharge in fractured, basaltic systems. Timing of recharge obtained through noble gas temperatures (NGTs) for all samples is corroborated by stable isotopes. Except for one sample, combined NGTs and stable isotope analyses point to recharge during the hot season for all low-altitude (<˜420 m) spring samples from San Cristobal and all basal aquifer samples in Santa Cruz. Stable isotope comparisons also indicate that San Cristobal springs located at high altitudes (>420 m above sea level) are recharged during both the "garúa" and hot seasons. Preservation of seasonality independently recorded by NGTs and stable isotopes is further reinforced by estimated young water ages. Samples located at high-altitude display systematic deviations of dissolved noble gases from expected air saturated water values and lead to inconsistent recharge altitudes and temperatures using standard NGT models. Existing degassing models are unable to account for the observed noble gas pattern for most samples. We explore various mechanisms to assess their potential at reproducing the observed noble gas signature. In particular, the potential impact of fog droplets during the cooler "garúa" season on dissolved noble gas concentrations in groundwater and the effect of mixing high-altitude (?1500 m) rainwater with low-altitude (˜400 m) fog droplets is explored. This mixing hypothesis is capable of explaining Ne and Xe concentrations for most high-altitude samples.

  20. A new rechargeable dialysis pore water sampler for monitoring sub-aqueous in-situ sediment caps

    Microsoft Academic Search

    Patrick H Jacobs

    2002-01-01

    A new rechargeable dialysis pore water sampler is proposed that is adapted to the requirements of monitoring in-situ sediment remediation techniques, in particular in-situ capping. Sampling and recharging of the sampler can be carried out from a boat or a pontoon by means of separate tubing and a peristaltic pump. The possibility of repeated sampling permits a temporal as well

  1. Chloride and the environmental isotopes as the indicators of the groundwater recharge in the Gobi Desert, northwest China

    Microsoft Academic Search

    J. Z. Ma; Z. Ding; J. B. Gates; Y. Su

    2008-01-01

    The long term recharge in Gobi Desert from Hexi Corridor to Inner Mongolia Plateau was estimated to be 1 mm year-1 by using the chloride mass balance method from one unsaturated zone profile, which shows that no effective modern recharge is taking place. A good rainfall database from Zhangye provides definition of the stable isotopic composition of modern rainfall. The

  2. Temporal dynamics of soil water balance components in a karst range in southeastern Spain: estimation of potential recharge

    Microsoft Academic Search

    Yolanda Cantón; Luis Villagarcía; María José Moro; Penelope Serrano-Ortíz; Ana Were; Francisco Javier Alcalá; Andrew S. Kowalski; Alberto Solé-Benet; Roberto Lázaro; Francisco Domingo

    2010-01-01

    This paper analyses the temporal dynamics of soil water balance components in a representative recharge area of the Sierra de Gádor (Almeria, southeastern Spain) in two hydrological years. Two approaches are used to estimate daily potential recharge (PR): Approach 1 based on deriving PR from the water balance as the difference between measurements of rainfall (P) and actual evapotranspiration (E)

  3. High-Capacity Micrometer-Sized Li2S Particles as Cathode Materials for Advanced Rechargeable Lithium-Ion Batteries

    E-print Network

    Cui, Yi

    Lithium-Ion Batteries Yuan Yang, Guangyuan Zheng, Sumohan Misra,§ Johanna Nelson,§ Michael F. Toney as the cathode material for rechargeable lithium-ion batteries with high specific energy. INTRODUCTION Rechargeable lithium-ion batteries have been widely used in portable electronics and are promising

  4. Remote sensing and GIS for mapping groundwater recharge and discharge areas in salinity prone catchments, southeastern Australia

    Microsoft Academic Search

    Sarah O. Tweed; Marc Leblanc; John A. Webb; Maciek W. Lubczynski

    2007-01-01

    Identifying groundwater recharge and discharge areas across catchments is critical for implementing effective strategies for salinity mitigation, surface-water and groundwater resource management, and ecosystem protection. In this study, a synergistic approach has been developed, which applies a combination of remote sensing and geographic information system (GIS) techniques to map groundwater recharge and discharge areas. This approach is applied to an

  5. Remote sensing and GIS for mapping groundwater recharge and discharge areas in salinity prone catchments, southeastern Australia

    Microsoft Academic Search

    Sarah O. Tweed; Marc Leblanc; John A. Webb; Maciek W. Lubczynski

    2006-01-01

    Identifying groundwater recharge and discharge areas across catchments is critical for implementing effective strategies for salinity mitigation, surface-water and groundwater resource management, and ecosystem protection. In this study, a synergistic approach has been developed, which applies a combination of remote sensing and geographic information system (GIS) techniques to map groundwater recharge and discharge areas. This approach is applied to an

  6. Quantifying Modern Recharge to the Nubian Sandstone Aquifer System: Inferences from GRACE and Land Surface Models

    NASA Astrophysics Data System (ADS)

    Mohamed, A.; Sultan, M.; Ahmed, M.; Yan, E.

    2014-12-01

    The Nubian Sandstone Aquifer System (NSAS) is shared by Egypt, Libya, Chad and Sudanand is one of the largest (area: ~ 2 × 106 km2) groundwater systems in the world. Despite its importance to the population of these countries, major hydrological parameters such as modern recharge and extraction rates remain poorly investigated given: (1) the large extent of the NSAS, (2) the absence of comprehensive monitoring networks, (3) the general inaccessibility of many of the NSAS regions, (4) difficulties in collecting background information, largely included in unpublished governmental reports, and (5) limited local funding to support the construction of monitoring networks and/or collection of field and background datasets. Data from monthly Gravity Recovery and Climate Experiment (GRACE) gravity solutions were processed (Gaussian smoothed: 100 km; rescaled) and used to quantify the modern recharge to the NSAS during the period from January 2003 to December 2012. To isolate the groundwater component in GRACE data, the soil moisture and river channel storages were removed using the outputs from the most recent Community Land Model version 4.5 (CLM4.5). GRACE-derived recharge calculations were performed over the southern NSAS outcrops (area: 835 × 103 km2) in Sudan and Chad that receive average annual precipitation of 65 km3 (77.5 mm). GRACE-derived recharge rates were estimated at 2.79 ± 0.98 km3/yr (3.34 ± 1.17 mm/yr). If we take into account the total annual extraction rates (~ 0.4 km3; CEDARE, 2002) from Chad and Sudan the average annual recharge rate for the NSAS could reach up to ~ 3.20 ± 1.18 km3/yr (3.84 ± 1.42 mm/yr). Our recharge rates estimates are similar to those calculated using (1) groundwater flow modelling in the Central Sudan Rift Basins (4-8 mm/yr; Abdalla, 2008), (2) WaterGAP global scale groundwater recharge model (< 5 mm/yr, Döll and Fiedler, 2008), and (3) chloride tracer in Sudan (3.05 mm/yr; Edmunds et al. 1988). Given the available global coverage of the temporal GRACE solutions for the past twelve years and plans are underway for the deployment of a GRACE follow-On and GRACE-II missions, we suggest that within the next few years, GRACE will probably become the most practical, informative, and cost-effective tool for monitoring the recharge of large aquifers across the globe.

  7. Carbyne Polysulfide as a Novel Cathode Material for Rechargeable Magnesium Batteries

    PubMed Central

    NuLi, Yanna; Chen, Qiang; Wang, Weikun; Wang, Ying; Yang, Jun; Wang, Jiulin

    2014-01-01

    We report the formation of carbyne polysulfide by coheating carbon containing carbyne moieties and elemental sulfur. The product is proved to have a sp2 hybrid carbon skeleton with polysulfide attached on it. The electrochemical performance of carbyne polysulfide as a novel cathode material for rechargeable magnesium batteries is firstly investigated. The material exhibits a high discharge capacity of 327.7?mAh g?1 at 3.9?mA g?1. These studies show that carbyne polysulfide is a promising candidate as cathode material for rechargeable Mg batteries if the capacity retention can be significantly improved. PMID:24587704

  8. Dynamics of Floodwater Infiltration and Groundwater Recharge Under Ephemeral Channels in Arid Regions

    NASA Astrophysics Data System (ADS)

    Tatarsky, B.; Dahan, O.; Enzel, Y.

    2007-05-01

    Shallow alluvial aquifers underneath ephemeral streams are often the only reliable source of water that can sustain human habitation in arid environments (e.g. Arava Valley, Israel; Rio Andarax, Spain; Kuiseb River, Namibia). The main source of replenishment of these alluvial aquifers is recharge from floodwater infiltration. Accordingly, effective management of surface water and groundwater in arid regions requires a better understanding of the processes controlling floodwater infiltration and recharge of alluvial aquifers. This study focuses on understanding the dynamic process of floodwater infiltration from ephemeral channels while implementing innovative methods specifically designed to quantify the recharge fluxes. The monitoring system provides real-time continuous measurements of the hydraulic conditions in all three domains involved in the recharge process: (a) the flood, (b) water-content variations along the unsaturated profile, (c) the groundwater response to the recharge event. Water-content variations along the unsaturated profile were monitored using flexible TDR (FTDR) probes installed along slanted boreholes underneath the stream channel. Water levels and salinity of both the flood and the groundwater were measured simultaneously. Two study sites were selected for this work: the Buffels River, South Africa and the Kuiseb River, Namibia. The monitoring stations installed at those sites recorded several flood events during 2005/2006. Data collected during this period revealed the dynamic process in which floodwater percolates through the vadose zone and recharges the groundwater. Each flood initiated an infiltration event expressed by wetting of the vadose zone and a rise in the water table. The sequential wetting of the vadose zone allowed direct calculations of the wetting-front propagation velocities and percolation fluxes from land surface down to the groundwater. With the arrival of the wetting front to the water table, groundwater began to rise, indicating an increase in groundwater storage in response to the recharge event. Water fluxes were calculated using several independent methods: (a) combining the calculated wetting-front propagation velocity with the change in moisture profile, (b) the rate at which the water table rises as an indication of the percolation rate, and (c) the final increase in groundwater storage through the measured change in groundwater levels. Interestingly, the calculations performed for all of the floods yielded corresponding flux values of approximately 1 cm/h. Aquifer dimensions, as well as total recharge estimations, were also derived from the data. Salt-transport dynamics at each site and the positive influence of the flood events on groundwater quality were revealed from the EC measurements.

  9. Method of and means for utilizing rechargeable batteries in the operation of electric vehicles

    SciTech Connect

    Muller-Werth, B.

    1981-07-07

    The engine of an automotive vehicle is powered by an assembly of electric batteries which are recharged from time to time, on standstill or during driving, from various sources including a set of solar cells on the vehicle body, braking generators driven by the vehicle wheels on deceleration, and external power supplies. Both the batteries and the solar cells can be selectively connected in series and in parallel, the former particularly during recharging. The batteries are grouped in thermally insulated blocks of molded resin with channels, left from the injection-molding operation, accommodating ancillary equipment such as electronic switches mounted on cooling bars.

  10. PLATINUM AND FUEL CELLS

    EPA Science Inventory

    Platinum requirements for fuel cell vehicles (FCVS) have been identified as a concern and possible problem with FCV market penetration. Platinum is a necessary component of the electrodes of fuel cell engines that power the vehicles. The platinum is deposited on porous electrodes...

  11. LIQUID METAL FUEL TECHNOLOGY

    Microsoft Academic Search

    B. R. T. Frost; C. C. Addison; A. Chitty; G. A. Geach; P. Gross; J. A. James; G. J. Metcalfe; T. Raine; H. A. Sloman

    1959-01-01

    The work carried out at a number of laboratories on the metallurgical ; problems associated with the development of liquid metal fuelled reactors is ; outlined. The major effort has been concerned with a circulating fuel thermal ; system which employs a fuel of uranium dissolved in bismuth and a thorium-bismuth ; slurry blanket. However, a considerable amount of work

  12. Solid State Research CenterDOE Fuel Cell Portable Power Workshop End User Perspective Industrial

    E-print Network

    -term applications (2002 - 2004): · Desktop/travel chargers ­ Cell-phones, Laptops, PDAs , etc. · Cordless (no socket term (2003 - 2005): · Hybrid (fuel cell + battery) or battery replacements: ­ Cell-phones, Laptops-50 retail price · Rechargeable Batteries ­ NiMH, Li-Ion, Li-polymer ­ $20-50 (cell phone) ­ $50-150 (laptop

  13. Areas Contributing Recharge to Wells in the Tafuna-Leone Plain, Tutuila, American Samoa

    USGS Publications Warehouse

    Izuka, Scot K.; Perreault, Jeff A.; Presley, Todd K.

    2007-01-01

    To address the concerns about the potential for contamination of drinking-water wells in the Tafuna-Leone Plain, Tutuila, American Samoa, a numerical ground-water flow model was developed and used to delineate areas contributing recharge to the wells (ACRWs). Surveys and analyses were conducted to obtain or compile certain essential hydrogeologic information needed for the model, such as groundwater production statistics, ground-water levels under current production, and an assessment of the distribution of groundwater recharge. The ground-water surveys indicate that total production from all wells in the Tafuna-Leone Plain between 1985 and 2005 averaged 6.1 Mgal/d and showed a gradual increase. A synoptic survey indicates that current water levels in the Tafuna-Leone Plain are highest near its inland boundary, decrease toward the coast, and are slightly depressed in high-production well fields. Ground-water levels showed little effect from the increased production because hydraulic conductivites are high and withdrawal is small relative to recharge. Analysis of ground-water recharge using a soil water-budget analysis indicates that the Tafuna-Leone Plain and adjacent areas receive about 280 Mgal/d of water from rainfall, of which 24 percent runs off to the ocean, 26 percent is removed by evapotranspiration, and 50 percent goes to ground-water recharge. Ground-water recharge per unit area is generally higher at the mountain crests than at the coast, but the highest recharge per unit area is in the mountain-front recharge zone at the juncture between the Tafuna-Leone Plain and the adjacent mountains. Surface water from the mountains also contributes to ground-water recharge in the eastern Tafuna-Leone Plain, in a process analogous to mountain-front recharge described in arid areas. Analysis of stream-gage data indicates that in the mountains of Tutuila, ground water discharges and contributes substantially to the total flow of the streams. In contrast, multiple lines of evidence indicate that in the eastern Tafuna-Leone Plain, surface water recharges the highly permeable underlying aquifer. Steady-state model simulations representing current ground-water production conditions in the Tafuna-Leone Plain indicate that most ACRWs extend less than a mile from the production wells; thus, travel distance between any point within an ACRW and its well is short. A simulation representing a condition in which all wells are operating at maximum capacity resulted in larger ACRWs, which demonstrates that increasing ground-water withdrawal from existing wells, or building and developing new wells, increases the surface area that could potentially contribute contaminants. In some places, such as in Malaeimi Valley, water can travel quickly via surface-water routes to an area where the water can infiltrate within the ACRWs of a well field.

  14. Alternative Fuels Infrastructure Development

    SciTech Connect

    Bloyd, Cary N.

    2010-06-30

    This summary reviews the status of alternate transportation fuels development and utilization in Thailand. An understanding of the issues and experiences associated with the introduction of alternative fuels in other countries can help the US in anticipation potential problems as it introduces new automotive fuels. Thailand is of particular interest since it introduced E20 to its commercial market in 2007 and the US is now considering introducing E20 into the US market.

  15. Rechargeable Lithium-Air Batteries: Development of Ultra High Specific Energy Rechargeable Lithium-Air Batteries Based on Protected Lithium Metal Electrodes

    SciTech Connect

    None

    2010-07-01

    BEEST Project: PolyPlus is developing the world’s first commercially available rechargeable lithium-air (Li-Air) battery. Li-Air batteries are better than the Li-Ion batteries used in most EVs today because they breathe in air from the atmosphere for use as an active material in the battery, which greatly decreases its weight. Li-Air batteries also store nearly 700% as much energy as traditional Li-Ion batteries. A lighter battery would improve the range of EVs dramatically. Polyplus is on track to making a critical breakthrough: the first manufacturable protective membrane between its lithium–based negative electrode and the reaction chamber where it reacts with oxygen from the air. This gives the battery the unique ability to recharge by moving lithium in and out of the battery’s reaction chamber for storage until the battery needs to discharge once again. Until now, engineers had been unable to create the complex packaging and air-breathing components required to turn Li-Air batteries into rechargeable systems.

  16. Estimation of temporal and spatial variations in groundwater recharge in unconfined sand aquifers using Scots pine inventories

    NASA Astrophysics Data System (ADS)

    Ala-aho, P.; Rossi, P. M.; Kløve, B.

    2014-07-01

    Climate change and land use are rapidly changing the amount and temporal distribution of recharge in northern aquifers. This paper presents a novel method for distributing Monte Carlo simulations of 1-D soil profile spatially to estimate transient recharge in an unconfined esker aquifer. The modeling approach uses data-based estimates for the most important parameters controlling the total amount (canopy cover) and timing (depth of the unsaturated zone) of groundwater recharge. Scots pine canopy was parameterized to leaf area index (LAI) using forestry inventory data. Uncertainty in the parameters controlling soil hydraulic properties and evapotranspiration was carried over from the Monte Carlo runs to the final recharge estimates. Different mechanisms for lake, soil, and snow evaporation and transpiration were used in the model set-up. Finally, the model output was validated with independent recharge estimates using the water table fluctuation method and baseflow estimation. The results indicated that LAI is important in controlling total recharge amount, and the modeling approach successfully reduced model uncertainty by allocating the LAI parameter spatially in the model. Soil evaporation compensated for transpiration for areas with low LAI values, which may be significant in optimal management of forestry and recharge. Different forest management scenarios tested with the model showed differences in annual recharge of up to 100 mm. The uncertainty in recharge estimates arising from the simulation parameters was lower than the interannual variation caused by climate conditions. It proved important to take unsaturated depth and vegetation cover into account when estimating spatially and temporally distributed recharge in sandy unconfined aquifers.

  17. Simplicity versus complexity in modelling groundwater recharge in Chalk catchments Hydrology and Earth System Sciences, 6(5), 927937 (2002) EGS

    E-print Network

    Paris-Sud XI, Université de

    2002-01-01

    Simplicity versus complexity in modelling groundwater recharge in Chalk catchments 927 Hydrology recharge in Chalk catchments R.B. Bradford1 , R. Ragab1 , S.M. Crooks1 , F. Bouraoui2 and E. Peters3 1@ceh.ac.uk Abstract Models of varying complexity are available to provide estimates of recharge in headwater Chalk

  18. Estimated recharge to the Madison and Minnelusa aquifers in the Black Hills area, South Dakota and Wyoming, water years 1931-98

    USGS Publications Warehouse

    Carter, J.M.; Driscoll, D.G.; Hamade, G.R.

    2001-01-01

    The Madison and Minnelusa aquifers are two of the most important aquifers in the Black Hills area. Long-term estimates of recharge to the Madison and Minnelusa aquifers are important for managing the water resources in the Black Hills area. Thus, annual recharge from streamflow losses and infiltration of precipitation on outcrop areas is estimated for water years 1931-98. All estimates are for recharge that contributes to regional ground-water flow patterns and that occurs in outcrop areas connected to the regional flow system. Estimates exclude recharge to outcrop areas that are isolated from the regional flow system, which generally results in ground-water discharge to area streams. Streamflow recharge is calculated directly for 11 streams in the Black Hills area that have continuous-record gaging stations located upstream from loss zones, using available records of daily streamflow, against which estimated loss thresholds (from previous investigations) are applied. Daily streamflow records are extrapolated, when necessary, using correlations with long-term gages, to develop annual estimates of streamflow recharge for 1950-98. Streamflow recharge is estimated for a number of smaller basins using loss thresholds for miscellaneous-record sites. Annual recharge estimates are derived from synthetic records of daily streamflow for 1992-98, which are based on drainage-area ratios applied to continuous-record gaging stations. Recharge estimates are further extrapolated for 1950-91, based on the average percentage of streamflow recharge contributed by these basins during 1992-98, relative to overall streamflow recharge.Streamflow recharge also is estimated for small drainage areas with undetermined loss thresholds that are situated between larger basins with known thresholds. Estimates for 1992-98 are based on estimates of annual streamflow derived using drainage-area ratios, with assumed losses equal to 90 percent of annual streamflow. Recharge estimates also are extrapolated for 1950-91, based on the average percentage of streamflow recharge contributed by these basins.Precipitation recharge for 1931-98 is estimated using relations between precipitation and streamflow (or basin yield) for representative gaging stations. Basin yields are first normalized, relative to drainage area, by expressing in inches per unit of drainage area. Yields are further converted to yield efficiencies, by dividing by precipitation on contributing drainage areas. Relations between yield efficiency and precipitation are identified, which are developed for use in generically estimating annual yield for given areas, based on average yield efficiency and annual precipitation. The resulting annual yield is used as a surrogate for estimating annual recharge from infiltration of precipitation on outcrop areas of the Madison and Minnelusa aquifers. Annual yield (or recharge) efficiencies are estimated to range from about 2 percent to in excess of 30 percent, with corresponding average annual recharge estimates ranging from 0.4 inch in the southern Black Hills to about 8.7 inches in the northwestern Black Hills.Estimates of precipitation recharge for 1931-49 are used to estimate streamflow recharge for the same period, based on correlations between the two variables for 1989-98. Combined streamflow and precipitation recharge to both aquifers averaged about 344 ft3/s for 1931-98. Streamflow recharge averaged about 93 ft3/s, or 27 percent of combined recharge, and precipitation recharge averaged about 251 ft3/s, or 73 percent of combined recharge. Combined recharge ranged from 62 ft3/s in 1936 to 847 ft3/s in 1995. The lowest recharge amounts generally occurred during the 1930?s; however, a more prolonged period of low recharge occurred during 1947-61.For 1931-98, average precipitation recharge to the Madison aquifer is about 3.6 inches, compared with 2.6 inches for the Minnelusa aquifer. However, recharge volumes to these aquifers are nearly identical because th

  19. Unitized regenerative fuel cell systems

    SciTech Connect

    Mitlitsky, F; Molter, T M; Myers, B; Weisberg, A H

    1998-09-10

    Energy storage systems with extremely high specific energy (>400 Wh/kg) have been designed that use lightweight pressure vessels to contain the gases generated by reversible (unitized) regenerative fuel cells (URFCs).[1] URFC systems are being designed and developed for a variety of applications, including high altitude long endurance (HALE) solar rechargeable aircraft (SRA), zero emission vehicles (ZEVs), hybrid energy storage/propulsion systems for spacecraft, energy storage for remote (off-grid) power sources, and peak shaving for on-grid applications.[1-10] Energy storage for HALE SRA was the original application for this set of innovations, and a prototype solar powered aircraft (Pathfinder-Plus) recently set another altitude record for all propeller-driven aircraft on August 6, 1998, when it flew to 80,285 feet (24.47 km).[11

  20. Remote sensing of hydrologic recharge in the Peace-Athabasca Delta, Canada

    E-print Network

    Smith, Laurence C.

    ., 1996], large-scale storage of soil carbon [Sheng et al., 2004; Frey and Smith, 2005], and critical theoretical models of floodplain recharge fail to capture observed patterns of inundation in the PAD. Instead connections do exist between the two. Results have strong management implications for the impact of proposed

  1. INCORPORATION OF CHLORIDE MASS BALANCE TO IMPROVE ESTIMATES OF EVAPOTRANSPIRATION, RECHARGE, AND RUNOFF

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A method was presented whereby measured soil water chloride concentrations and long-term precipitation and air temperature were interpreted to estimate evapotranspiration, recharge, and runoff. By applying the chloride mass balance technique, soil water chloride profiles provided a basis for improv...

  2. LAS VEGAS VALLEY WATER BUDGET: RELATIONSHIP OF DISTRIBUTION, CONSUMPTIVE USE, AND RECHARGE TO SHALLOW GROUND WATER

    EPA Science Inventory

    Estimates of quantity and geographic distribution of recharge to the shallow ground-water zone from water use return flows in Las Vegas Valley were made for the years 1973, 1965, 1958, 1950, and 1943 as part of a broader study on the impact of water and land use on ground-water q...

  3. Structural micro-porous carbon anode for rechargeable lithium-ion batteries

    DOEpatents

    Delnick, F.M.; Even, W.R. Jr.; Sylwester, A.P.; Wang, J.C.F.; Zifer, T.

    1995-06-20

    A secondary battery having a rechargeable lithium-containing anode, a cathode and a separator positioned between the cathode and anode with an organic electrolyte solution absorbed therein is provided. The anode comprises three-dimensional microporous carbon structures synthesized from polymeric high internal phase emulsions or materials derived from this emulsion source, i.e., granules, powders, etc. 6 figs.

  4. Using computerized water well records to delineate and map groundwater recharge-transition-discharge potential

    SciTech Connect

    Hughes, L.D.; Passero, R.N. (Western Michigan Univ., Kalamazoo, MI (United States). Geology Dept.)

    1994-04-01

    A methodology for delineating areas of groundwater recharge, transition, and discharge was developed using the Golden contouring software package, thirty years of computerized well records, obtained from the Kalamazoo County Groundwater Database, and base maps form the Michigan Resource Information System (MIRIS). Supplemental surface water values were digitized from USGS topographic maps. The study was conducted at township and county levels. Using state plane coordinates and static water elevations, the database was separated into two data sets differentiated by shallow and deep depths of submergence. A gridded surface was generated for each data set using the interpolation methods available with the software program. The deeper submergence grid was subtracted from the shallow submergence grid. The resulting positive values indicated areas of recharge, negative values indicated areas of discharge, and a range of plus or minus five feet indicated areas of transition. Regression analysis was used to compare the recharge/discharge surface to water table and topographic surfaces. The study indicated that although the method works reasonably well, the results are best at the county scale and in areas of greatest topographic relief. Those areas with low topographic relief tend not to recognize surface water drainage. This is primarily due to the methods of interpolation rather than a failure in the methodology. Limits on well depth and separation interval for the two data sets are also critical to the interpretation. The presence of pumping wells can influence the contoured surface and must be evaluated for each recharge/discharge surface generated.

  5. A low power battery management system for rechargeable wireless implantable electronics

    Microsoft Academic Search

    Pengfei Li; Rizwan Bashirullah; José Carlos Príncipe

    2006-01-01

    An integrated battery management system for low power wireless implantable electronics is presented herein. The system is designed for miniature implantable Li-ion rechargeable batteries with limited cell capacity and employs a new control loop that relaxes comparator resolution requirements, provides simultaneous operation of constant-current and constant voltage loops, and eliminates the external current sense resistor from the charging path. The

  6. Rainfall intensity and groundwater recharge: evidence from ground-based observations in East Africa (Invited)

    NASA Astrophysics Data System (ADS)

    Taylor, R. G.; Owor, M.; Kaponda, A.

    2013-12-01

    Global greenhouse-gas emissions serve to warm Africa more rapidly than the rest of the world. The intensification of precipitation that is associated with this warming, strongly influences terrestrial water budgets. This shift toward fewer but heavier rainfall events is expected to lead to more frequent and intense floods as well as more variable and lower soil moisture. However, its impact on groundwater recharge is unclear and in dispute. We review evidence from long (1 to 5 decades) time series of groundwater levels recorded in deeply weathered crystalline rock aquifers systems underlying land surfaces of low relief in Uganda and Tanzania. Borehole hydrographs consistently demonstrate a non-linear relationship between rainfall and recharge wherein heavy rainfalls exceeding a threshold contribute disproportionately to the recharge flux. Rapid responses observed in groundwater levels to rainfall events attest further to the importance of preferential pathways in enabling rain-fed recharge via soil macro-pores. Our results suggest that, in these environments, increased use of groundwater to offset periods of low surface flow and to supplement soil moisture through irrigation may prove a logical strategy to enhance regional water and food security.

  7. Impacts of soil conservation on groundwater recharge in the semi-arid Loess Plateau, China

    E-print Network

    Scanlon, Bridget R.

    soils are critical to maintaining food security and environmental quality. Human-induced soil erosionImpacts of soil conservation on groundwater recharge in the semi-arid Loess Plateau, China John B in a semi-arid area of China's Loess Plateau that has been subject to extensive soil conservation activities

  8. Natural attenuation of priority and emerging contaminants during river bank filtration and artificial recharge.

    E-print Network

    Paris-Sud XI, Université de

    Natural attenuation of priority and emerging contaminants during river bank filtration Seine river water downstream of the Paris area, water from a primary well after bank filtration, water, were monitored during five campaigns. River bank filtration and to a lesser extent artificial recharge

  9. Battery arrays, rechargable Li-ion battery power sources for marine applications

    Microsoft Academic Search

    Jon Crowell

    2005-01-01

    The design of battery systems for marine devices has become very complex with the introduction of rechargeable lithium-ion battery technology. In the past, battery technology such as sealed lead acid was fairly simple to design into a system. Battery cells could be strapped in series and parallel to achieve the desired voltage, current and total capacity. This is not possible

  10. Electrochimica Acta 51 (2006) 20122022 A generalized cycle life model of rechargeable Li-ion batteries

    E-print Network

    Popov, Branko N.

    2006-01-01

    ­discharge model to simulate the cycle life behavior of rechargeable Li-ion batteries has been developed. The model and Newman [4] made a first attempt to model the parasitic reaction in Li-ion batteries by assuming a solvent and reversible capacity loss due to the growth and dissolution of SEI film in Li-ion batteries. Ramadass et al

  11. Short communication Ion beam-mixed Ge electrodes for high capacity Li rechargeable batteries

    E-print Network

    Volinsky, Alex A.

    Short communication Ion beam-mixed Ge electrodes for high capacity Li rechargeable batteries N modification Ge Germanium Li ion battery anode a b s t r a c t Ion beam modification to effect ion beam mixing in the use of conversion (or synthesizing) electrodes like Si, Ge, and Sn for Li ion battery anodes, which

  12. Application of advanced borehole geophysical logging to managed aquifer recharge investigations

    Microsoft Academic Search

    Robert G. Maliva; Edward A. Clayton; Thomas M. Missimer

    2009-01-01

    Communities and water utilities are increasingly being forced to implement more hydrogeologically complex alternative water supply and storage options to meet increasing freshwater demands. The performance of managed aquifer recharge projects, including aquifer storage and recovery, is controlled by the movement and mixing of stored freshwater and native groundwater, and fluid-rock interactions, which, in turn, are strongly influenced by aquifer

  13. Deep-basin groundwater recharge in southwest Indian Wells Valley, Kern County, CA

    Microsoft Academic Search

    1996-01-01

    Hydrographs of monthly depth to water measurements in nested piezometers in southwest Indian Wells Valley indicate that the response to recharge in the deep wells is different than that of the shallow wells. The southwestern most deep piezometer experienced the largest rise in water level, after the spring snow melt and the largest overall rise after one year. The shallow

  14. EVALUATING THE IMPACT OF BRUSH CLEARING ON RECHARGE TO A KARST AQUIFER

    EPA Science Inventory

    My hypothesis is that brush removal will increase recharge, and this will be reflected in drip rate and drip water chemistry in the cave below. The results from this study should contribute to the understanding of how environmental variables affect karst hydrology. This stu...

  15. Recharge and pumping hydraulics in a till drumlin above fractured bedrock (Massachusetts, USA)

    NASA Astrophysics Data System (ADS)

    Ostendorf, David W.; Lukas, William G.; Rotaru, Camelia

    2015-02-01

    Recharge and pumping hydraulics of a till-mantled bedrock are analyzed with existing closed-form theory and 12 years of monthly water levels in cluster wells from Scituate Hill, a glacial till drumlin in eastern Massachusetts (USA). The weathered brown till atop Scituate Hill is an unconfined aquifer, delivering steady recharge and a seasonally varying recharge-head fluctuation to the unweathered gray till aquitard beneath it. The water-table fluctuations generate no seasonally varying flow field in the gray till, due to the relatively low hydraulic diffusivity of the brown till. Nearby irrigation pumps drilled into the underlying Dedham Granite in 2011 have introduced seasonal drawdown, and the gray till leaks into the fractured bedrock aquifer. The leakage reflects the moderate diffusivity of the gray till and the relatively high hydraulic diffusivity of the fractured bedrock. Both seasonal disturbances are mildly attenuated across the gray till, so that the Dedham Granite senses recharge, while the water table in Scituate Hill is drawn down by irrigation pumping. Steady and seasonal gray till data are accordingly used to calibrate the transmissivity and storativity of the fractured bedrock and specific yield of the brown till, with physically plausible values.

  16. ARTIFICIAL RECHARGE TO THE SNAKE PLAIN AQUIFER, AN EVALUATION OF POTENTIAL AND EFFECT, 1969

    EPA Science Inventory

    The major factors involved in using surplus water for artificial recharge of the Snake Plain aquifer in southern and southeastern Idaho (17040212, 17040209, 17040206, 17040201) are the availability of water, the probably effects of water mixing on ground-water quality and physica...

  17. Battery switch array system with application for JPL's rechargeable micro-scale batteries

    Microsoft Academic Search

    Mahmoud Alahmad; Herb Hess; Mohammad Mojarradi; William West; Jay Whitacre

    2008-01-01

    A battery switch array system is developed for solid-state rechargeable micro-scale lithium batteries, designed and developed by Jet Propulsion Laboratory (JPL), California Institute of Technology, for aerospace applications. The heart of the system is a topology unique in its dynamic reconfiguration ability by providing selective connection and isolation and versatile in its core design by incorporating passive, active or energy

  18. Silicon nanowire boost for rechargeable batteries Online Shop Contact us Advanced

    E-print Network

    Cui, Yi

    Silicon nanowire boost for rechargeable batteries Online Shop Contact us Advanced search Chemistry catalyst. The new battery has a charge capacity of 4277mA hours per gram - over ten times higher than - they just get fatter. Yi Cui, assistant professor at the Department of Materials Science and Engineering

  19. A screening tool for delineating subregions of steady recharge within groundwater models

    USGS Publications Warehouse

    Dickinson, Jesse E.; Ferré, T. P. A.; Bakker, Mark; Crompton, Becky

    2014-01-01

    We have developed a screening method for simplifying groundwater models by delineating areas within the domain that can be represented using steady-state groundwater recharge. The screening method is based on an analytical solution for the damping of sinusoidal infiltration variations in homogeneous soils in the vadose zone. The damping depth is defined as the depth at which the flux variation damps to 5% of the variation at the land surface. Groundwater recharge may be considered steady where the damping depth is above the depth of the water table. The analytical solution approximates the vadose zone diffusivity as constant, and we evaluated when this approximation is reasonable. We evaluated the analytical solution through comparison of the damping depth computed by the analytic solution with the damping depth simulated by a numerical model that allows variable diffusivity. This comparison showed that the screening method conservatively identifies areas of steady recharge and is more accurate when water content and diffusivity are nearly constant. Nomograms of the damping factor (the ratio of the flux amplitude at any depth to the amplitude at the land surface) and the damping depth were constructed for clay and sand for periodic variations between 1 and 365 d and flux means and amplitudes from nearly 0 to 1 × 10?3 m d?1. We applied the screening tool to Central Valley, California, to identify areas of steady recharge. A MATLAB script was developed to compute the damping factor for any soil and any sinusoidal flux variation.

  20. A fire-resistant organophosphorus gel polymer electrolyte additive for use in rechargeable lithium batteries

    Microsoft Academic Search

    Robert V Morford; E. Clay Kellam; Michael A Hofmann; Richard Baldwin; Harry R Allcock

    2000-01-01

    The development of a small-molecule organophosphorus gel polymer electrolyte additive for use in rechargeable lithium batteries is described. This organophosphorus additive is less volatile and more resistant to ignition than propylene carbonate, a well known component of gel polymer electrolytes. Moreover, the ionic conductivities of gels containing the organophosphorus additive at low molar concentrations (11–21%) exceed the ionic conductivities of

  1. MULTIPLE METHODS OF RECHARGE ESTIMATION AT A HUMID-REGION FRACTURED ROCK SITE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In humid regions, aquifer recharge through an unconfined, low-porosity, fractured rock aquifer can cause large magnitude water table fluctuations over short time scales. The unsaturated hydraulic characteristics of the subsurface porous media control the magnitude and timing of these fluctuations. ...

  2. ESTIMATING AQUIFER RECHARGE THROUGH PLAYAS OF THE GREAT PLAINS USING TEMPERATURE PROBES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The magnitude of recharge through playa wetlands in the High Plains has often been debated, but rarely been quantified. The ephemeral nature of playas makes it difficult and expensive to observe the filling and drying/draining cycles. Rugged, inexpensive tools to demonstrate the movement of water b...

  3. Structural micro-porous carbon anode for rechargeable lithium-ion batteries

    DOEpatents

    Delnick, Frank M. (Albuquerque, NM); Even, Jr., William R. (Livermore, CA); Sylwester, Alan P. (Washington, DC); Wang, James C. F. (Livermore, CA); Zifer, Thomas (Manteca, CA)

    1995-01-01

    A secondary battery having a rechargeable lithium-containing anode, a cathode and a separator positioned between the cathode and anode with an organic electrolyte solution absorbed therein is provided. The anode comprises three-dimensional microporous carbon structures synthesized from polymeric high internal phase emulsions or materials derived from this emulsion source, i.e., granules, powders, etc.

  4. On the accuracy of noble gas recharge temperatures as a paleoclimate proxy

    Microsoft Academic Search

    Bradley D. Cey

    2009-01-01

    Dissolved noble gases in groundwater are an important terrestrial temperature proxy for the last glacial maximum (LGM). Noble gas temperatures (NGT) provide a record of long-term mean water table temperature (WTT) during groundwater recharge. For NGT to accurately represent surface air temperatures (SAT), the difference between mean annual air temperature (MAAT) and WTT must be known through time. Many paleoclimate

  5. Technology assessment of ambient temperature rechargeable lithium batteries for electric vehicle applications

    NASA Astrophysics Data System (ADS)

    Doddapaneni, N.

    1991-07-01

    This report presents an assessment of ambient temperature rechargeable lithium batteries for electric vehicle applications. It was prepared for the Department of Energy, Office of Propulsion Systems. The status of development programs in industry and research laboratories was determined for several positive and negative electrode materials and for organic liquid and solid polymer electrolytes. Recommendations are suggested for future research and development activities.

  6. Carbonate aquifer of the Central Roswell Basin: recharge estimation by numerical modeling

    Microsoft Academic Search

    K. R. Rehfeldt; G. W. Gross

    1982-01-01

    The flow of ground water in the Roswell, New Mexico, Artesian Basin, has been studied since the early 1900s and varied ideas have been proposed to explain different aspects of the ground water flow system. The purpose of the present study was to delineate the spatial distribution and source, or sources, of recharge to the carbonate aquifer of the central

  7. Evidence for dilution of deep, confined ground water by vertical recharge of isotopically heavy Pleistocene water

    SciTech Connect

    Siegel, D.I. (Syracuse Univ. NY (USA))

    1991-05-01

    New analyses of the isotopic composition of water, {sup 14}C-dating of dissolved inorganic carbon, and order-of-magnitude Darcy calculations suggest that a dilute body of water, trending north-south in the Cambrian-Ordovician aquifer of Iowa, was emplaced as vertical recharge of Pleistocene-age water from the base of the Des Moines lobe of late Wisconsin time. The recharge occurred through more than 300 m of overlaying Silurian to Mississippian age rocks. The {delta}{sup 18}O values range from {minus}10{per thousand} to {minus}9{per thousand} for the dilute water body and are consistent with a mixture of Des Moines lobe meltwater and precipitation found today in the north-central US. These results suggest that (1) the climate at the end of the last glaciation was mild and (2) a ground-water stable isotope signature similar to that of modern precipitation in an aquifers recharge area is not a priori evidence for relatively recent recharge.

  8. Groundwater Recharge F. Edwin Harvey, Associate Professor School of Natural Resources, UNL

    E-print Network

    Nebraska-Lincoln, University of

    (sometimes called runoff). (2) It could evaporate (E) back into the atmosphere directly from the soil surface, or from a ponded area of water (pond, lake, stream, etc.) (3) It could percolate into the soil will be added to the groundwater reservoir and thus be available for use as a resource. The amount of recharge

  9. An improved time series approach for estimating groundwater recharge from groundwater level fluctuations

    Microsoft Academic Search

    M. O. Cuthbert

    2010-01-01

    An analytical solution to a linearized Boussinesq equation is extended to develop an expression for groundwater drainage using estimations of aquifer parameters. This is then used to develop an improved water table fluctuation (WTF) technique for estimating groundwater recharge. The resulting method extends the standard WTF technique by making it applicable, as long as aquifer properties for the area are

  10. A field study of advanced municipal wastewater treatment technology for artificial groundwater recharge

    Microsoft Academic Search

    Yun-zheng PI; Jian-long WANG

    2006-01-01

    Field studies were conducted to investigate the advanced treatment of the municipal secondary effluent and a subsequent artificial groundwater recharge at Gaobeidian Wastewater Treatment Plant, Beijing. To improve the secondary effluent quality, the combined process of powdered activated carbon adsorption, flocculation and rapid sand filtration was applied, which could remove about 40% dissolved organic carbon (DOC) and 70% adsorbable organic

  11. Zinc and silver migration during rechargeable silver-zinc cell cycling

    Microsoft Academic Search

    Harlan L. Lewis; Steven P. Wharton

    1997-01-01

    A study has been established to obtain zinc and silver migration rate data on cellulosic separators derived from a variety of cellulose and cellophane sources in silver-zinc alkaline rechargeable cells. The purpose of the study is to utilize the cycle and wet life data which are, in part, a function of the formation of soft and hard shorting in the

  12. Environmental technology verification report: Rechargeable alkaline household battery system, Rayovac Corporation Renewal{trademark}

    Microsoft Academic Search

    T. Escarda; N. Lewis

    1999-01-01

    The EPA`s ETV Program, in partnership with recognized testing organizations, objectively and systematically documents the performance of commercial ready technologies. Together, with the full participation of the technology developer, they develop plans, conduct tests, collect and analyze data, and report findings. Rayovac redesigned their alkaline household batteries so that they could be recharged. The additional charge cycles extend battery life

  13. Long life, low cost, rechargeable AgZn battery for non-military applications

    Microsoft Academic Search

    Curtis C. Brown

    1996-01-01

    Of the rechargeable (secondary) battery systems with mature technology, the silver oxide-zinc system (AgZn) safely offers the highest power and energy (watts and watt hours) per unit of volume and mass. As a result they have long been used for aerospace and defense applications where they have also proven their high reliability. In the past, the expense associated with the

  14. Environmental technology verification report: Rechargeable alkaline household battery system, Rayovac Corporation Renewal[trademark

    Microsoft Academic Search

    T. Escarda; N. Lewis

    1999-01-01

    The EPA's ETV Program, in partnership with recognized testing organizations, objectively and systematically documents the performance of commercial ready technologies. Together, with the full participation of the technology developer, they develop plans, conduct tests, collect and analyze data, and report findings. Rayovac redesigned their alkaline household batteries so that they could be recharged. The additional charge cycles extend battery life

  15. Theoretical and Experimental Study of Vanadium-Based Fluorophosphate Cathodes for Rechargeable Batteries

    E-print Network

    Henkelman, Graeme

    Batteries Maowen Xu,,§, Penghao Xiao,, Shannon Stauffer, Jie Song, Graeme Henkelman,*,, and John B window, including swapping the anions from O and F to less-electronegative Cl and Br. The most promising for the development of the rechargeable Li-ion battery is the need to store electrical energy generated by wind

  16. Uncertainty in Climatology-Based Estimates of Shallow Ground Water Recharge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The groundwater recharge (GR) estimates for flow and transport projections are often evaluated as a fixed percentage of average annual precipitation. The chemical transport in variably saturated heterogeneous porous media is not linearly related to the average velocity. The objective of this study w...

  17. Findings of the rechargeable battery study sponsored by NATIBO (North American technology and industrial base organization)

    NASA Astrophysics Data System (ADS)

    Gucinski, James A.; Slack, Michael

    This paper summarizes and updates the findings of the North American technology and industrial base organization (NATIBO) study entitled "Rechargeable Battery/Systems for Communication/Electronic Application". The mission of the NATIBO organization is to promote a cost effective and healthy technology and industrial base that is responsive to the national and economical security needs of the United States and Canada.

  18. Advanced membranes for alkaline primary and rechargeable alkaline cells with zinc anodes

    Microsoft Academic Search

    Harlan Lewis; Patricia Jackson; Alvin Salkind; Thomas Danko; Roger Bell

    2001-01-01

    Several advanced cellulosic and radiation grafted polypropylene membrane materials are currently under evaluation in the laboratories at Navsea Crane and Rutgers University, for application to alkaline primary and rechargeable cell chemistries which employ zinc as the anode material. A portion of these tests involve model cell evaluations of cellulosic membranes for silver migration rates through the membranes as a function

  19. Herbicide Leaching on a Recharge Area of the Guarany Aquifer in Brazil

    Microsoft Academic Search

    Antonio L. Cerdeira; Neife A. G. dos Santos; Maria C. P. Y. Pessoa; Marco A. F. Gomes; Vera L. Lanchote

    2005-01-01

    The region of Ribeirão Preto City, located in Southeast of Brazil, São Paulo State, is an important sugarcane, soybean, and corn producing area with a high level of pesticides utilization. This region is also an important recharge area for groundwater supply of the Guarany aquifer. Since the past ten years atrazine, simazine, ametryn, tebuthiuron, diuron, 2,4-D, picloram, and hexazinone are

  20. Atrazine in Source Water Intended for Artificial Ground-Water Recharge, South-Central Kansas

    USGS Publications Warehouse

    Christensen, Victoria G.; Ziegler, Andrew C.

    1998-01-01

    Atrazine, an herbicide commonly applied to row crops, is of concern because of potential effects on water quality. This fact sheet describes atrazine in water from the Little Arkansas River in south-central Kansas. The river is being evaluated as a source of artificial recharge into the Equus Beds aquifer, which provides water for the city of Wichita.