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1

An aqueous rechargeable battery based on zinc anode and Na(0.95)MnO2.  

PubMed

An aqueous rechargeable battery system is assembled by using metallic zinc and Na(0.95)MnO2 as the negative and positive electrodes, respectively. It is cheap and environmentally friendly, and its energy density is 78 Wh kg(-1). Its cycling performance is very good with only 8% capacity loss after 1000 cycles at 4 C between 1 and 2 V. PMID:24327312

Zhang, Baihe; Liu, Yu; Wu, Xiongwei; Yang, Yaqiong; Chang, Zheng; Wen, Zubiao; Wu, Yuping

2014-02-01

2

Degradation mechanism of layered MnO 2 cathodes in Zn/ZnSO 4/MnO 2 rechargeable cells  

NASA Astrophysics Data System (ADS)

Layered-type MnO 2 ( ?- or naturally occurring birnessite-related MnO 2) electrodes that suffer capacity degradation during extended cycling in Zn/ZnSO 4/MnO 2 rechargeable cells are investigated. When the composite cathodes consisting of MnO 2 powder, carbon additive and Teflon binder are galvanostatically cycled in the potential range of 1.0-1.9 V (vs. Zn/Zn 2+) where a two-step, two-electron charge/discharge reaction occurs, the cathodes lose their capacities within a few cycles. Such an abrupt capacity loss is found to be caused partly by the formation of basic zinc sulfates (BZS, ZnSO 43Zn(OH) 2 nH 2O) on the cathode surface, and also by the Mn losses due to the irreversible nature of the cathodic cell reaction: Mn 2+ ions, once produced during the discharge step, are not fully restored to MnO 2 during the charging period. An addition of 0.1-0.5 M MnSO 4 to 2 M ZnSO 4 electrolyte, however, greatly alleviates these failure modes. With this addition, the Mn losses become insignificant as a result of facilitation in the charging reaction and BZS formation is discouraged. Carbon additives loaded in the composite MnO 2 cathodes also critically affect the cathode cyclabilities by controlling the rate of charging reaction: the cathodes loaded with acetylene blacks display superior cyclabilities to those containing furnace blacks. From one observation whereby the acetylene blacks possess a lesser amount of surface oxygenic species than the furnace blacks and the other whereby the charging reaction more readily occurs in the former cathodes, it is proposed that the charging (deposition) reaction is significantly hindered by the presence of surface oxygenic species on carbon additives. Electron micrographs of cycled MnO 2 cathodes reveal that larger and porous MnO 2 deposits are well-grown on the acetylene-black-loaded cathodes whereas only irregular-shaped smaller deposits are formed on the furnace-black-loaded cathodes.

Kim, Sa Heum; Oh, Seung Mo

3

Rechargeable hybrid aqueous batteries  

NASA Astrophysics Data System (ADS)

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 2V 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 50-80Whkg-1, is comparable or superior to commercial 2V 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.

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

2012-10-01

4

Improved performance of rechargeable alkaline batteries via surfactant-mediated electrosynthesis of MnO 2  

NASA Astrophysics Data System (ADS)

An innovative application of surfactant-mediated modifications of electrolytic MnO 2 (EMD), proved to be a major step toward enhancement of the rechargeability in alkaline batteries. Presence of different surfactants in boiling acidic solutions of manganese sulfate, under atmospheric pressure, enhanced a variety of EMD products, with various structural and electrochemical properties. Surfactants employed consisted of: anionic sodium n-dodecylbenzenesulfonate (SDBS), cationic cetyltrimethylammonium bromide (CTAB) and non-ionic t-octyl phenoxy polyethoxyethanol (Triton X-100). Among them, EMDs produced in the presence of CTAB has a slight positive effect on the cycle performances, while SDBS inhibits it. Interestingly, the EMD powders prepared from the micellar solution, in the range of 0.3 wt.% of Triton X-100, exhibited much higher discharge capacities, as well as better cyclabilities in comparison with the commercial EMD sample known as TOSOH. The superiority of the former EMD was further confirmed through electrochemical cyclic voltammetry and also electrochemical impedance spectroscopy (EIS). Modifications of electrolytic MnO 2, via mediations of different surfactants were perceived through changes in their compositions, crystal structures and morphologies. The characteristics of the produced materials were determined by thermogravimetric analysis (TGA), powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). Enhancements of electrochemical properties, observed for Triton X-100 modified EMD, could be attributed to a homogeneous current distribution with unique crystalline structure, based on the modified electrode/solution interface, through adsorbed surfactant layers. Moreover, the observed improvements appear connected to the enhanced film growth, with different degrees of mesoscopic organizations. Higher cycle performances, mechanical stabilities and the ease of production make this method excellent for being employed in a number of industrial applications.

Ghaemi, M.; Khosravi-Fard, L.; Neshati, J.

5

?-MnO2 nanostructures directly grown on Ni foam: a cathode catalyst for rechargeable Li-O2 batteries.  

PubMed

A sponge-like ?-MnO2 nanostructure was synthesized by direct growth of ?-MnO2 on Ni foam through a facile electrodeposition route. When applied as a self-supporting, binder-free cathode material for rechargeable nonaqueous lithium-oxygen batteries, the ?-MnO2/Ni electrode exhibits considerable high-rate capability (discharge capacity of ?6300 mA h g(-1) at a current density of 500 mA g(-1)) and enhanced cyclability (exceeding 120 cycles) without controlling the discharge depth. The superior performance is proposed to be associated with the 3D nanoporous structures and abundant oxygen defects as well as the absence of side reactions related to carbon-based conductive additives and binders. PMID:24577589

Hu, Xiaofei; Han, Xiaopeng; Hu, Yuxiang; Cheng, Fangyi; Chen, Jun

2014-04-01

6

?-MnO2 nanostructures directly grown on Ni foam: a cathode catalyst for rechargeable Li-O2 batteries  

NASA Astrophysics Data System (ADS)

A sponge-like ?-MnO2 nanostructure was synthesized by direct growth of ?-MnO2 on Ni foam through a facile electrodeposition route. When applied as a self-supporting, binder-free cathode material for rechargeable nonaqueous lithium-oxygen batteries, the ?-MnO2/Ni electrode exhibits considerable high-rate capability (discharge capacity of ~6300 mA h g-1 at a current density of 500 mA g-1) and enhanced cyclability (exceeding 120 cycles) without controlling the discharge depth. The superior performance is proposed to be associated with the 3D nanoporous structures and abundant oxygen defects as well as the absence of side reactions related to carbon-based conductive additives and binders.A sponge-like ?-MnO2 nanostructure was synthesized by direct growth of ?-MnO2 on Ni foam through a facile electrodeposition route. When applied as a self-supporting, binder-free cathode material for rechargeable nonaqueous lithium-oxygen batteries, the ?-MnO2/Ni electrode exhibits considerable high-rate capability (discharge capacity of ~6300 mA h g-1 at a current density of 500 mA g-1) and enhanced cyclability (exceeding 120 cycles) without controlling the discharge depth. The superior performance is proposed to be associated with the 3D nanoporous structures and abundant oxygen defects as well as the absence of side reactions related to carbon-based conductive additives and binders. Electronic supplementary information (ESI) available: Detailed synthesis procedures and material characterizations, additional SEM, CV, TGA, BET, and electrochemical impedance spectroscopy results. See DOI: 10.1039/c3nr06361e

Hu, Xiaofei; Han, Xiaopeng; Hu, Yuxiang; Cheng, Fangyi; Chen, Jun

2014-03-01

7

Performance of MnO2 Crystallographic Phases in Rechargeable Lithium-Air Oxygen Cathode  

NASA Astrophysics Data System (ADS)

Manganese dioxide (MnO2) has been shown to be effective for improving the efficiency of cathodes in lithium-air cells. Different crystallographic phases including ?-, ?-, and ?-MnO2 nanowires, ?-MnO2 nanospheres, and ?-MnO2 nanowires on carbon ( ?-MnO2/C) were synthesized using the hydrothermal method. Their physical properties were examined using x-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area measurements, and scanning electron microscopy (SEM) and found to be in agreement with the literature. Electrochemical properties of the synthesized catalyst particles were investigated by fabricating cathodes and testing them in a lithium-air cell with lithium hexafluorophosphate in propylene carbonate (LiPF6/PC) and tetra(ethylene glycol)dimethyl ether (LiTFSi/TEGDME) electrolytes. ?-MnO2 had the highest discharge capacity in the LiTFSi/TEGDME electrolyte (2500 mAh/g), whilst ?-MnO2/C in LiPF6/PC showed a significantly higher discharge capacity of 11,000 mAh/g based on total mass of the catalytic cathode. However, the latter showed poor capacity retention compared with ?-MnO2 nanowires, which was stable for up to 30 cycles. The reported discharge capacity is higher than recorded in previous studies on lithium-air cells.

Oloniyo, Olubukun; Kumar, Senthil; Scott, Keith

2012-05-01

8

Rechargeable Na/Na0.44MnO2 cells with ionic liquid electrolytes containing various sodium solutes  

NASA Astrophysics Data System (ADS)

Orthorhombic Na0.44MnO2 with wide structural tunnels for sodium ion transport is synthesized. Butylmethylpyrrolidinium-bis(trifluoromethanesulfonyl)imide (BMP-TFSI) ionic liquid (IL) with various Na solutes, namely NaBF4, NaClO4, NaTFSI, and NaPF6, is used as an electrolyte for rechargeable Na/Na0.44MnO2 cells. The cell with NaClO4-incorporated IL electrolyte exhibits superior charge-discharge performance due to it having the lowest solid-electrolyte-interface resistance and charge transfer resistance at both the Na and Na0.44MnO2 electrodes. The IL electrolyte shows high thermal stability and is suitable for use at an elevated temperature. At 75C, the measured capacity of Na0.44MnO2 in the IL electrolyte with NaClO4 is as high as 115mAhg-1 (at 0.05 C), which is close to the theoretical value (121mAhg-1). Moreover, 85% of this capacity can be retained when the charge-discharge rate is increased to 1 C. These properties are superior to those of a conventional organic electrolyte.

Wang, Chueh-Han; Yeh, Yu-Wen; Wongittharom, Nithinai; Wang, Yi-Chen; Tseng, Chung-Jen; Lee, Sheng-Wei; Chang, Wen-Sheng; Chang, Jeng-Kuei

2015-01-01

9

Predicting the electrochemical properties of MnO2 nanomaterials used in rechargeable li batteries: simulating nanostructure at the atomistic level.  

PubMed

Nanoporous beta-MnO2 can act as a host lattice for the insertion and deinsertion of Li with application in rechargeable lithium batteries. We predict that, to maximize its electrochemical properties, the beta-MnO2 host should be symmetrically porous and heavily twinned. In addition, we predict that there exists a "critical (wall) thickness" for MnO2 nanomaterials above which the strain associated with Li insertion is accommodated via a plastic, rather than elastic, deformation of the host lattice leading to property fading upon cycling. We predict that this critical thickness lies between 10 and 100 nm for beta-MnO2 and is greater than 100 nm for alpha-MnO2: the latter accommodates 2 x 2 tunnels compared with the smaller 1 x 1 tunnels found in beta-MnO2. This prediction may help explain why certain (nano)forms of MnO2 are electrochemically active, while others are not. Our predictions are based upon atomistic models of beta-MnO2 nanomaterials. In particular, a systematic strategy, analogous to methods widely and routinely used to model crystal structure, was used to generate the nanostructures. Specifically, the (space) symmetry associated with the nanostructure coupled with basis nanoparticles was used to prescribe full atomistic models of nanoparticles (0D), nanorods (1D), nanosheets (2D), and nanoporous (3D) architectures. For the latter, under MD simulation, the amorphous nanoparticles agglomerate together with their periodic neighbors to formulate the walls of the nanomaterial; the particular polymorphic structure was evolved using simulated amorphization and crystallization. We show that our atomistic models are in accord with experiment. Our models reveal that the periodic framework architecture, together with microtwinning, enables insertion of Li anywhere on the (internal) surface and facilitates Li transport in all three spatial directions within the host lattice. Accordingly, the symmetrically porous MnO2 can expand and contract linearly and crucially elastically under charge/discharge. We also suggest tentatively that our predictions for MnO2 are more general in that similar arguments may apply to other nanomaterials, which might expand and contract elastically upon charging/discharging. PMID:19206514

Sayle, Thi X T; Maphanga, R Rapela; Ngoepe, Phuti E; Sayle, Dean C

2009-05-01

10

Rechargeable lithium batteries with aqueous electrolytes.  

PubMed

Rechargeable lithium-ion batteries that use an aqueous electrolyte have been developed. Cells with LiMn(2)O(4) and VO(2)(B) as electrodes and 5 M LiNO(3) in water as the electrolyte provide a fundamentally safe and cost-effective technology that can compete with nickelcadmium and lead-acid batteries on the basis of stored energy per unit of weight. PMID:17744893

Li, W; Dahn, J R; Wainwright, D S

1994-05-20

11

Rechargeable lithium batteries with aqueous electrolytes  

Microsoft Academic Search

Rechargeable lithium-ion batteries that use an aqueous electrolyte have been developed. Cells with LiMnO and VO(B) as electrodes and 5 M LiNO in water as the electrolyte provide a fundamentally safe and cost-effective technology that can compete with nickel-cadmium and lead-acid batteries on the basis of stored energy per unit of weight.14 refs., 4 figs.

Wu Li; J. R. Dahn; D. S. Wainwright

1994-01-01

12

Oxygen Bubble-Templated Hierarchical Porous ?-MnO2 as a Superior Catalyst for Rechargeable Li-O2 Batteries.  

PubMed

Nickel foam-supported ?-MnO2 is synthesized through an oxygen-bubble template-assisted electrodeposition route and is applied as a new cathode catalyst for Li-O2 batteries. Owing to the 3D macro/micro/nano (multiscale) porous architecture, the prepared electrode exhibits low overpotential, high rate capability, and superior cycling durability. PMID:25273825

Hu, Xiaofei; Cheng, Fangyi; Han, Xiaopeng; Zhang, Tianran; Chen, Jun

2015-02-01

13

Advances of aqueous rechargeable lithium-ion battery: A review  

NASA Astrophysics Data System (ADS)

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.

Alias, Nurhaswani; Mohamad, Ahmad Azmin

2015-01-01

14

Silicon anode for rechargeable aqueous lithium-air batteries  

NASA Astrophysics Data System (ADS)

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.

Teranishi, R.; Si, Q.; Mizukoshi, F.; Kawakubo, M.; Matsui, M.; Takeda, Y.; Yamamoto, O.; Imanishi, N.

2015-01-01

15

Sol-gel MnO 2 as an electrode material for electrochemical capacitors  

NASA Astrophysics Data System (ADS)

MnO 2 was synthesized by the sol-gel method. Two forms of MnO 2, namely xerogel and ambigel, were prepared by reduction of NaMnO 4 and KMnO 4 with sodium fumarate. The synthesized products were characterized using X-ray diffraction (XRD), Brunauer-Emmet-Teller (BET), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and chemical analysis. Electrochemical characterization was carried out using cyclic voltammetry by a three electrode system consisting of saturated calomel electrode as reference electrode, platinum mesh as a counter electrode, and sol-gel prepared MnO 2 mounted on Ti mesh used as working electrode. Aqueous NaCl, KCl, Na 2SO 4 and LiCl solutions were used as electrolytes. The ambigel form of MnO 2 showed high capacitance compared to that of the xerogel form of MnO 2. Maximum capacitance of 130 F/g was obtained at a scan rate of 5 mV/s for the ambigel form of MnO 2 in a 2 M NaCl solution. Effect of NaCl concentration on the capacitance of MnO 2 was studied. Stability of MnO 2 was studied up to 800 cycles.

Reddy, Ravinder N.; Reddy, Ramana G.

16

Structure and Manufacturing Process of MnO2 Counter Electrode in Niobium Suboxide Capacitors  

NASA Astrophysics Data System (ADS)

The influence of iterative heat treatment of impregnated aqueous Mn(NO3)2 solution on the microstructure of the produced MnO2 has been investigated in the fabrication process for niobium suboxide capacitors. We separate the whole process into two stages: At the early stage of impregnations in Mn(NO3)2 solution (with specific density less than 1.35 g/cm3), the produced MnO2 grains with equiaxed nanocrystalline morphology are mainly located in the inner space and pores, avoiding the performance deterioration due to the electrical conductivity anisotropy of columnar texture in NbO capacitors. For impregnation in Mn(NO3)2 solutions with specific density greater than 1.35 g/cm3, MnO2 grains in the inner space and pores continue to grow and present a hexagonal pyramid shape. At this stage, MnO2 starts to be produced on the outer surface of pellets and exhibits a cluster morphology that consists of MnO2 grains with size between 30 nm and 80 nm. The electrical performance of NbO capacitors has been optimized by adjusting the impregnation times and sequence. By alternately impregnating in Mn(NO3)2 solutions with specific densities of 1.23 g/cm3 and 1.35 g/cm3, MnO2 grains are better combined and the internal space of the pellets is fully filled. Impregnation in Mn(NO3)2 solutions with low specific densities (1.10 g/cm3 and 1.23 g/cm3) in dry atmosphere produces a denser MnO2 layer in the internal space, leading to improved capacitor performance.

Chen, Liqin; Li, Bo; Qi, Zhaoxiong; Guo, Hai; Zhou, Ji; Li, Longtu

2013-10-01

17

Synthesis and characterization of different MnO2 morphologies for lithium-air batteries  

NASA Astrophysics Data System (ADS)

Manganese dioxide (MnO2) was synthesized in the forms of nanorods, nanoparticles, and mesoporous structures and the characteristics of these materials were investigated. Crystallinities were studied by x-ray diffraction and morphologies by scanning and transmission electron microscopy. Average pore sizes and specific surface areas were analyzed using the Barret-Joyner-Halenda and Brunauer-Emmett-Teller methods, respectively. Samples were also studied by cyclic voltammetry using 1M aqueous KOH solution saturated with either O2 or N2 as electrolytes to investigate their ORR (oxygen reduction reaction) and OER (oxygen evolution reaction) activities. Of the samples produced, mesoporous MnO2 exhibited the highest ORR and OER catalytic activities. Mesoporous MnO2 supported on a gas diffusion layer was also used as a catalyst on the air electrode (cathode) of a lithium-air battery in organic electrolyte. The charge-discharge behavior of mesoporous MnO2 was investigated at a current density 0.2 mAcm-2 in a pure oxygen environment. Mesoporous MnO2 electrodes showed stable cycleability up to 65 cycles at a cell capacity of 700 mAhg-1.

Choi, Hyun-A.; Jang, Hyuk; Hwang, Hyein; Choi, Mincheol; Lim, Dongwook; Shim, Sang Eun; Baeck, Sung-Hyeon

2014-09-01

18

An aqueous rechargeable formate-based hydrogen battery driven by heterogeneous pd catalysis.  

PubMed

The formate-based rechargeable hydrogen battery (RHB) promises high reversible capacity to meet the need for safe, reliable, and sustainable H2 storage used in fuel cell applications. Described herein is an additive-free RHB which is based on repetitive cycles operated between aqueous formate dehydrogenation (discharging) and bicarbonate hydrogenation (charging). Key to this truly efficient and durable H2 handling system is the use of highly strained Pd nanoparticles anchored on graphite oxide nanosheets as a robust and efficient solid catalyst, which can facilitate both the discharging and charging processes in a reversible and highly facile manner. Up to six repeated discharging/charging cycles can be performed without noticeable degradation in the storage capacity. PMID:25382034

Bi, Qing-Yuan; Lin, Jian-Dong; Liu, Yong-Mei; Du, Xian-Long; Wang, Jian-Qiang; He, He-Yong; Cao, Yong

2014-12-01

19

An Aqueous Rechargeable Lithium Battery Using Coated Li Metal as Anode  

PubMed Central

New energy industry including electric vehicles and large-scale energy storage in smart grids requires energy storage systems of good safety, high reliability, high energy density and low cost. Here a coated Li metal is used as anode for an aqueous rechargeable lithium battery (ARLB) combining LiMn2O4 as cathode and 0.5?mol l?1 Li2SO4 aqueous solution as electrolyte. Due to the cross-over effect of Li+ ions in the coating, this ARLB delivers an output voltage of about 4.0?V, a big breakthrough of the theoretic stable window of water, 1.229?V. Its cycling is very excellent with Coulomb efficiency of 100% except in the first cycle. Its energy density can be 446?Wh kg?1, about 80% higher than that for traditional lithium ion battery. Its power efficiency can be above 95%. Furthermore, its cost is low and safety is much reliable. It provides another chemistry for post lithium ion batteries. PMID:23466633

Wang, Xujiong; Hou, Yuyang; Zhu, Yusong; Wu, Yuping; Holze, Rudolf

2013-01-01

20

Organized and highly dispersed growth of MnO 2 nano-rods by sonochemical hydrolysis of Mn(3)acetate  

Microsoft Academic Search

Highly dispersed and non-agglomerated ?-MnO2 nano-needles of dimensions 2030nm have been synthesized by the application of ultrasound radiation on the aqueous solution consisting of manganese(3)acetate close to neutral pH followed by mild drying. With a similar reaction system, hot hydrolysis (non-sonochemical process) produced ?-MnO2 nano-rods of length 100200nm but with high degree agglomeration. Sonochemical cavitation phenomenon is suggested to have

V. Ganesh Kumar; Kwang Bum Kim

2006-01-01

21

Growth of One-Dimensional MnO2 Nanostructure  

NASA Astrophysics Data System (ADS)

Large scale MnO2 nanorods were controllably synthesized from the inexpensive precursors (e.g., manganese acetate, ammonium persulfate) via a facile one-step low temperature hydrothermal strategy. The crystal phase and microscopic morphology of the as-prepared MnO2 nanorods were characterized by X-ray powder diffraction (XRD) and scanning electron microscope (SEM). Through investigating the morphology evolution of MnO2 products in the whole synthesis process, a novel growth mechanism of these MnO2 nanorods was proposed, which may be efficiently extended to other material systems as a general approach towards one-dimensional nanostructures. The obtained MnO2 nanorods may have potential applications in Li-ion batteries and supercapacitors.

Lu, Pai; Xue, Dongfeng

22

High-capacity nanostructured manganese dioxide cathode for rechargeable magnesium ion batteries  

NASA Astrophysics Data System (ADS)

Nanostructured ?-MnO2 and ?-MnO2 are investigated for use in rechargeable Mg ion battery (MIB) cathodes. In order to prepare nanosized particles, the manganese dioxides are prepared by the acid treatment of spinel MgMn2O4 synthesized using the Pechini method. X-ray diffraction analysis indicates that the resulting MnO2 consists of multiple phases, ?-MnO2, ?-MnO2, and ?-MnO2, depending on the leaching time in acid solution. Upon the first charge-discharge cycle in acetonitrile electrolyte, the ?-MnO2 based electrode shows larger reversible capacity of ?330 mAh g-1 compared to an electrode containing a large amount of ?-MnO2. This enhanced capacity is associated with the facile charge-transfer reaction of Mg ions at the MnO2/electrolyte interfaces. The capacity fading of MnO2 in different electrolytes is also discussed in terms of the formation of a surface layer at the electrode/electrolyte interface during the charging process.

Kim, Ju-Sik; Chang, Won-Seok; Kim, Ryoung-Hee; Kim, Dong-Young; Han, Dong-Wook; Lee, Kyu-Hyoung; Lee, Seok-Soo; Doo, Seok-Gwang

2015-01-01

23

High-energy MnO2 nanowire/graphene and graphene asymmetric electrochemical capacitors.  

PubMed

In order to achieve high energy and power densities, we developed a high-voltage asymmetric electrochemical capacitor (EC) based on graphene as negative electrode and a MnO(2) nanowire/graphene composite (MGC) as positive electrode in a neutral aqueous Na(2)SO(4) solution as electrolyte. MGC was prepared by solution-phase assembly of graphene sheets and ?-MnO(2) nanowires. Such aqueous electrolyte-based asymmetric ECs can be cycled reversibly in the high-voltage region of 0-2.0 V and exhibit a superior energy density of 30.4 Wh kg(-1), which is much higher than those of symmetric ECs based on graphene//graphene (2.8 Wh kg(-1)) and MGC//MGC (5.2 Wh kg(-1)). Moreover, they present a high power density (5000 W kg(-1) at 7.0 Wh kg(-1)) and acceptable cycling performance of ?79% retention after 1000 cycles. These findings open up the possibility of graphene-based composites for applications in safe aqueous electrolyte-based high-voltage asymmetric ECs with high energy and power densities. PMID:20857919

Wu, Zhong-Shuai; Ren, Wencai; Wang, Da-Wei; Li, Feng; Liu, Bilu; Cheng, Hui-Ming

2010-10-26

24

Periodic Current Oscillation Catalyzed by ?-MnO2 Nanosheets.  

PubMed

The oxygen evolution reaction (OER) is of wide interest for both fuel and hydrometallurgy applications. Different types of nanoscale MnO2 , varying from nanosheets to nanoneedles, are synthesized and assembled on the anode to investigate their catalytic effect on the nonlinear kinetics of the MnO2 -catalyzed OER at high current. For ?-MnO2 nanosheets, periodic current oscillations (PCO) occurr and occupy up to 40?% of the total energy consumption. The PCO can help to reduce the energy consumption under constant current conditions. Its amplitude could be twice of that for the previously reported MnO2 grown by an in?situ electrochemical method. If the amount of ?-MnO2 nanoneedles increases, the oscillation disappears. For different Mn oxides, the rate constants of H2 O2 decomposition differ, resulting in changes in oscillation features. The results of this study may enable new ideas to improve the efficiency of industrial electrolysis and charging-discharging of supercapacitors. PMID:25382485

Fan, Xing; Yang, Dianpeng; Ding, Lifeng; Du, Jun; Tao, Changyuan

2014-11-01

25

Cobalt dissolution in LiCoO 2-based non-aqueous rechargeable batteries  

Microsoft Academic Search

Rechargeable lithium batteries using a variety of differently prepared LiCoO2 samples were cycled to 4.5 V versus Li and the negative electrode was investigated for Co deposits after the cell was cycled over 25 times. Qualitative analysis revealed evidence of cobalt dissolution for samples showing high capacity loss with cycle number. A direct correlation between the percentage capacity loss and

G. G. Amatucci; J. M. Tarascon; L. C. Klein

1996-01-01

26

New-concept Batteries Based on Aqueous Li+/Na+ Mixed-ion Electrolytes  

PubMed Central

Rechargeable batteries made from low-cost and abundant materials operating in safe aqueous electrolytes are attractive for large-scale energy storage. Sodium-ion battery is considered as a potential alternative of current lithium-ion battery. As sodium-intercalation compounds suitable for aqueous batteries are limited, we adopt a novel concept of Li+/Na+ mixed-ion electrolytes to create two batteries (LiMn2O4/Na0.22MnO2 and Na0.44MnO2/TiP2O7), which relies on two electrochemical processes. One involves Li+ insertion/extraction reaction, and the other mainly relates to Na+ extraction/insertion reaction. Two batteries exhibit specific energy of 17?Wh kg?1 and 25?Wh kg?1 based on the total weight of active electrode materials, respectively. As well, aqueous LiMn2O4/Na0.22MnO2 battery is capable of separating Li+ and Na+ due to its specific mechanism unlike the traditional rocking-chair lithium-ion batteries. Hence, the Li+/Na+ mixed-ion batteries offer promising applications in energy storage and Li+/Na+ separation. PMID:23736113

Chen, Liang; Gu, Qingwen; Zhou, Xufeng; Lee, Saixi; Xia, Yonggao; Liu, Zhaoping

2013-01-01

27

Hydrogen Ion Supercapacitor: A New Hybrid Configuration of Highly Dispersed MnO2 in Porous Carbon Coupled with Nitrogen-Doped Highly Ordered Mesoporous Carbon with Enhanced H-Insertion.  

PubMed

A new configuration of hydrogen ion supercapacitors was reported. A positive electrode composed of pseudocapacitive MnO2, highly dispersed into active porous carbon through an impregnation method, was combined with a nitrogen-doped highly ordered mesoporous carbon with enhanced electrochemical hydrogen insertion capacity as a negative electrode. During the operation, hydrogen ion shuttled between MnO2 and carbon electrodes. The MnO2 was formed on the surface of nanostructured carbon through a spontaneous redox reaction. Operating in an aqueous neutral solution, the hybrid device demonstrated an extended working voltage to ?2.1 V with good cycle life. PMID:25458840

Qu, Deyu; Wen, Jianfeng; Liu, Dan; Xie, Zhizhong; Zhang, Xuran; Zheng, Dong; Lei, Jiahen; Zhong, Wei; Tang, Haolin; Xiao, Liang; Qu, Deyang

2014-12-24

28

Key scientific challenges in current rechargeable non-aqueous Li-O2 batteries: experiment and theory.  

PubMed

Rechargeable Li-air (henceforth referred to as Li-O2) batteries provide theoretical capacities that are ten times higher than that of current Li-ion batteries, which could enable the driving range of an electric vehicle to be comparable to that of gasoline vehicles. These high energy densities in Li-O2 batteries result from the atypical battery architecture which consists of an air (O2) cathode and a pure lithium metal anode. However, hurdles to their widespread use abound with issues at the cathode (relating to electrocatalysis and cathode decomposition), lithium metal anode (high reactivity towards moisture) and due to electrolyte decomposition. This review focuses on the key scientific challenges in the development of rechargeable non-aqueous Li-O2 batteries from both experimental and theoretical findings. This dual approach allows insight into future research directions to be provided and highlights the importance of combining theoretical and experimental approaches in the optimization of Li-O2 battery systems. PMID:24833409

Bhatt, Mahesh Datt; Geaney, Hugh; Nolan, Michael; O'Dwyer, Colm

2014-06-28

29

Nanostructured MnO2-Based Cathodes for Li-Ion/Polymer Cells  

NASA Technical Reports Server (NTRS)

Nanostructured MnO2-based cathodes for Li-ion/polymer electrochemical cells have been investigated in a continuing effort to develop safe, high-energy-density, reliable, low-toxicity, rechargeable batteries for a variety of applications in NASA programs and in mass-produced commercial electronic equipment. Whereas the energy densities of state-of-the-art lithium-ion/polymer batteries range from 150 to 175 W h/kg, the goal of this effort is to increase the typical energy density to about 250 W h/kg. It is also expected that an incidental benefit of this effort will be increases in power densities because the distances over which Li ions must diffuse through nanostructured cathode materials are smaller than those through solid bulk cathode materials.

Skandan, Ganesh; Singhal, Amit

2005-01-01

30

Electrochemical characterization of manganese oxide cathode materials based on Na 0.4MnO 2  

NASA Astrophysics Data System (ADS)

Cathode materials for lithium rechargeable batteries were prepared from Na 0.4MnO 2 by solution and molten salt ion-exchanges. The former process results in partial replacement of sodium while the latter results in complete exchange. The discharge characteristics depend upon the sodium content, with the partially lithiated material exhibiting hysteresis in the charge/discharge profile and differential capacity plots from stepped potential experiments. For the fully lithiated material, a complex voltage profile with several distinct plateaus corresponding to several two-phase regions is observed. No evidence of spinel formation during ion-exchange or electrochemical cycling is seen for this system.

Hu, Felix; Doeff, Marca M.

31

Hydrothermal synthesis of MnO2/CNT nanocomposite with a CNT core/porous MnO2 sheath hierarchy architecture for supercapacitors  

PubMed Central

MnO2/carbon nanotube [CNT] nanocomposites with a CNT core/porous MnO2 sheath hierarchy architecture are synthesized by a simple hydrothermal treatment. X-ray diffraction and Raman spectroscopy analyses reveal that birnessite-type MnO2 is produced through the hydrothermal synthesis. Morphological characterization reveals that three-dimensional hierarchy architecture is built with a highly porous layer consisting of interconnected MnO2 nanoflakes uniformly coated on the CNT surface. The nanocomposite with a composition of 72 wt.% (K0.2MnO20.33 H2O)/28 wt.% CNT has a large specific surface area of 237.8 m2/g. Electrochemical properties of the CNT, the pure MnO2, and the MnO2/CNT nanocomposite electrodes are investigated by cyclic voltammetry and electrochemical impedance spectroscopy measurements. The MnO2/CNT nanocomposite electrode exhibits much larger specific capacitance compared with both the CNT electrode and the pure MnO2 electrode and significantly improves rate capability compared to the pure MnO2 electrode. The superior supercapacitive performance of the MnO2/CNT nancomposite electrode is due to its high specific surface area and unique hierarchy architecture which facilitate fast electron and ion transport. PMID:24576342

2012-01-01

32

High-Performance Asymmetric Supercapacitors Based on Multilayer MnO2 /Graphene Oxide Nanoflakes and Hierarchical Porous Carbon with Enhanced Cycling Stability.  

PubMed

In this work, MnO2 /GO (graphene oxide) composites with novel multilayer nanoflake structure, and a carbon material derived from Artemia cyst shell with genetic 3D hierarchical porous structure (HPC), are prepared. An asymmetric supercapacitor has been fabricated using MnO2 /GO as positive electrode and HPC as negative electrode material. Because of their unique structures, both MnO2 /GO composites and HPC exhibit excellent electrochemical performances. The optimized asymmetric supercapacitor could be cycled reversibly in the high voltage range of 0-2 V in aqueous electrolyte, which exhibits maximum energy density of 46.7 Wh kg(-1) at a power density of 100 W kg(-1) and remains 18.9 Wh kg(-1) at 2000 W kg(-1) . Additionally, such device also shows superior long cycle life along with ?100% capacitance retention after 1000 cycles and ?93% after 4000 cycles. PMID:25384679

Zhao, Yufeng; Ran, Wei; He, Jing; Huang, Yizhong; Liu, Zhifeng; Liu, Wei; Tang, Yongfu; Zhang, Long; Gao, Dawei; Gao, Faming

2014-11-10

33

Polypyrrole-encapsulated vanadium pentoxide nanowires on a conductive substrate for electrode in aqueous rechargeable lithium battery.  

PubMed

Precursors of ammonium vanadium bronze (NH4V4O10) nanowires assembled on a conductive substrate were prepared by a hydrothermal method. After calcination at 360C, the NH4V4O10 precursor transformed to vanadium pentoxide (V2O5) nanowires, which presented a high initial capacity of 135.0mA h g(-1) at a current density of 50mA g(-1) in 5M LiNO3 aqueous solution; while the specific capacity faded quickly over 50 cycles. By coating the surface of V2O5 nanowires with water-insoluble polypyrrole (PPy), the formed nanocomposite electrode exhibited a specific discharge capacity of 89.9mA h g(-1) at 50mA g(-1) (after 100 cycles). A V2O5@PPy //LiMn2O4 rechargeable lithium battery exhibited an initial discharge capacity of 95.2mA h g(-1); and after 100 cycles, a specific discharge capacity of 81.5mA h g(-1) could retain at 100mA g(-1). PMID:25463177

Liang, Chaowei; Fang, Dong; Cao, Yunhe; Li, Guangzhong; Luo, Zhiping; Zhou, Qunhua; Xiong, Chuanxi; Xu, Weilin

2015-02-01

34

High cycling stability of zinc-anode/conducting polymer rechargeable battery with non-aqueous electrolyte  

NASA Astrophysics Data System (ADS)

A non-aqueous zinc-polyaniline secondary battery was fabricated with polyaniline Emeraldine base as cathode and zinc metal as anode in an electrolyte consisting of 0.3 M zinc-bis(trifluoromethyl-sulfonyl)imide Zn(TFSI)2 dissolved in propylene carbonate. We observed that the formation of the battery required a prerequisite condition to stabilize the interfaces in order to maintain a stable capacity. The battery suffered from Zn dissolution which induces a competition between concurrent Zn dissolution and plating when the battery is in charge mode, and thus inefficient cycles are obtained. The capacity and coulombic efficiency of the battery depends on the charge-discharge rates. We propose cycling protocols at different rates to determine the steady-state rates of competing reactions. When the cell is cycled at ?1 C rate, the coulombic efficiency improves. The maximum capacity and energy densities of the battery are 148 mAhg-1 and 127 mWhg-1, respectively for discharge at C/2. The battery was successively charged/discharged at constant current densities (1C rate), and high cycling stability was obtained for more than 1700 cycles at 99.8% efficiency. Zinc dissolution and self discharge of the battery were investigated after 24 h of standby. The investigation showed that the battery experiences a severe self-discharge of 48% perday.

Guerfi, A.; Trottier, J.; Boyano, I.; De Meatza, I.; Blazquez, J. A.; Brewer, S.; Ryder, K. S.; Vijh, A.; Zaghib, K.

2014-02-01

35

Energetic aqueous rechargeable sodium-ion battery based on Na2 CuFe(CN)6 -NaTi2 (PO4 )3 intercalation chemistry.  

PubMed

Aqueous rechargeable sodium-ion batteries have the potential to meet growing demand for grid-scale electric energy storage because of the widespread availability and low cost of sodium resources. In this study, we synthesized a Na-rich copper hexacyanoferrate(II) Na2 CuFe(CN)6 as a high potential cathode and used NaTi2 (PO4 )3 as a Na-deficient anode to assemble an aqueous sodium ion battery. This battery works very well with a high average discharge voltage of 1.4 V, a specific energy of 48 Wh kg(-1) , and an excellent high-rate cycle stability with approximately 90 % capacity retention over 1000 cycles, achieving a new record in the electrochemical performance of aqueous Na-ion batteries. Moreover, all the anode, cathode, and electrolyte materials are low cost and naturally abundant and are affordable for widespread applications. PMID:24464957

Wu, Xian-Yong; Sun, Meng-Ying; Shen, Yi-Fei; Qian, Jiang-Feng; Cao, Yu-Liang; Ai, Xin-Ping; Yang, Han-Xi

2014-02-01

36

Modification of MnO2 nanoparticles with rutin synthesized by Triton X-100 aggregations' template  

NASA Astrophysics Data System (ADS)

Manganese dioxide (MnO2) nanoparticles have been prepared through the redox reaction between KMnO4 and the nonionic surfactant Triton X-100 with the aid of rod-like micelles, hexagonal liquid crystals and reverse micelle templates, in which Triton X-100 acts both as template and reductant. MnO2 nanorods (20 50 nm in diameter) can be obtained in rod-like micelles and hexagonal liquid crystals, whereas MnO2 nanospheres (about 85 nm in diameter) are formed in reverse micelles. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are used to characterize the products. Modification of MnO2 nanoparticles by rutin has been discussed using fluorescence spectra and UV vis spectra, and the free radical eliminating investigations of surface-modified MnO2 nanoparticles with rutin show that MnO2 nanoparticles can improve the free-radical-scavenging activity of rutin.

Wang, Yi; Zhu, Jun; Han, Jie; Guo, Rong

2008-10-01

37

Generating MnO2 nanoparticles using simulated amorphization and recrystallization.  

PubMed

Models of MnO2 nanoparticles, with full atomistic detail, have been generated using a simulated amorphization and recrystallization strategy. In particular, a 25,000-atom "cube" of MnO2 was amorphized (tension-induced) under molecular dynamics (MD). Long-duration MD, applied to this system, results in the sudden evolution of a small crystalline region of pyrolusite-structured MnO2, which acts as a nucleating "seed" and facilitates the recrystallization of all the surrounding (amorphous) MnO2. The resulting MnO2 nanoparticle is about 8 nm in diameter, conforms to the pyrolusite structure (isostructural with rutile TiO2, comprising 1 x 1 octahedra) is heavily twinned and comprises a wealth of isolated and clustered point defects such as cation vacancies. In addition, we suggest the presence of ramsdellite (2 x 1 octahedra) intergrowths. Molecular graphical snapshots of the crystallization process are presented. PMID:16159276

Sayle, Thi X T; Catlow, C Richard A; Maphanga, R Regina; Ngoepe, Phuti E; Sayle, Dean C

2005-09-21

38

Lithium selective adsorption on 1-D MnO 2 nanostructure ion-sieve  

Microsoft Academic Search

?-MnO2, spinel-type Li4Mn5O12 and pure cubic phase MnO2 nanorod, with the size about 20140nm in diameter and 0.84?m in length, were synthesized via a combination of hydrothermal synthesis and low temperature solid-phase reaction, more favorable to control the nanocrystalline structure with well-defined pore size distribution and high surface area than the traditional high temperature calcination process. Further, the MnO2 ion-sieves

Qin-Hui Zhang; Shao-Peng Li; Shu-Ying Sun; Xian-Sheng Yin; Jian-Guo Yu

2009-01-01

39

Balance the reaction MnO4 (aq) MnO2(s) + SO4  

E-print Network

Balance the reaction MnO4 Ð (aq) + SO3 2Ð (aq) MnO2(s) + SO4 2Ð (aq) in basic solution Oxidation 2Ð SO4 2Ð (b) 2) These are already balanced in Mn and S 3) Balance O in (a) by adding H2O?s to the right-hand-side MnO4 Ð MnO2 + 2H2O 4) Balance H by adding H + to the left-hand-side MnO4 Ð + 4H + MnO2

Peterson, Kirk A.

40

Mixed alkali effect in glasses containing MnO2  

NASA Astrophysics Data System (ADS)

Glass systems of the composition xLi2O-(25-x)K2O-70(0.4ZnO+0.6P2O5)+5MnO2 (x = 4,8,12,16 and 20 mol %) have been prepared by melt quenching technique. The thermal and mechanical properties of the glasses have been evaluated as a function of mixed alkali content. Glass transition temperature and Vickers's hardness of the glasses show a pronounced deviation from linearity at 12 mol% Li2O. Theoretically estimated elastic moduli of the glasses show small positive deviations from linearity. MAE in these properties has been attributed to the localized changes in the glass network. The absorption spectra of Mn2+ ions in these glasses showed strong broad absorption band at 514 nm corresponding to the transition 6A1g(S)?4T1g(G), characteristic of manganese ions in octahedral symmetry. The fundamental absorption edge in UV region is used to study the optical transitions and electronic band structure. From UV absorption edge, optical band gap energies have been evaluated. Band gap energies of the glasses have exhibited MAE and shows minimum value for 12 mol% Li2O glass.

Reddy, M. Sudhakara; Rajiv, Asha; Veeranna Gowda, V. C.; Chakradhar, R. P. S.; Reddy, C. Narayana

2013-02-01

41

Controllable synthesis of MnO2/polyaniline nanocomposite and its electrochemical capacitive property  

PubMed Central

Polyaniline (PANI) and MnO2/PANI composites are simply fabricated by one-step interfacial polymerization. The morphologies and components of MnO2/PANI composites are modulated by changing the pH of the solution. Formation procedure and capacitive property of the products are investigated by XRD, FTIR, TEM, and electrochemical techniques. We demonstrate that MnO2 as an intermedia material plays a key role in the formation of sample structures. The MnO2/PANI composites exhibit good cycling stability as well as a high capacitance close to 207 F?g?1. Samples fabricated with the facile one-step method are also expected to be adopted in other field such as catalysis, lithium ion battery, and biosensor. PMID:23594724

2013-01-01

42

Binder free synthesis of MnO2 nanoplates/graphene composites with enhanced supercapacitive properties  

NASA Astrophysics Data System (ADS)

MnO2 nanoplates grown on graphene sheets have been directly synthesized during the graphite oxide (GO) reduction. The synthetic method is efficient, green and controllable with GO reduced and MnO2 nanoplates formed in one step. Compared with conventional methods, this method is easier to implement without using binders or any conductive additives. The as-prepared MnO2 nanoplates and graphene composites (GM) electrodes exhibit enhanced electrochemical performances, including ultrahigh specific capacitance (385 F g-1, at current density of 1 A g-1) and excellent cycling stabilities with 1 M Na2SO4 electrolytes. This improvement is due to the tighter contact between graphene sheets and MnO2 nanoplates, and the higher conductive and capacitive characteristics of graphene.

Li, Zijiong; Su, Yuling; Yun, Gaoqian; Shi, Kai; Lv, Xiaowei; Yang, Baocheng

2014-08-01

43

MnO2 nanolayers on highly conductive TiO(0.54)N(0.46) nanotubes for supercapacitor electrodes with high power density and cyclic stability.  

PubMed

Pseudo-capacitive MnO2 supercapacitors are attracting intense interest because of the theoretically high specific capacitance (1370 F g(-1)) and low cost of MnO2. For the practical application, the power density and the cyclic stability of MnO2-based supercapacitors are expected to be improved. Increasing the efficiency of the current collection is an effective method to improve the power density for a given supercapacitor. Here, the highly conductive and electrochemically stable material, titanium oxynitride (TiO0.54N0.46), is used as the current collector. Uniform amorphous MnO2 nanolayers were deposited on metal-phase TiO0.54N0.46 nanotube arrays using a modified electrochemical deposition method. The resulting MnO2 supercapacitors exhibited a high power density of 620 kW kg(-1) at an energy density of 9.8 W h kg(-1). This is comparable to high-performance carbon-based electrochemical double layer capacitors in aqueous electrolytes. The high electron transport was enhanced with a highly conductive TiO0.54N0.46 scaffold. Ion transport was promoted in the nanotube structures that had porous walls. In addition, the close interfacial connection between MnO2 and TiO0.54N0.46 contributed to the excellent cyclic stability (ca. 92.0% capacitance retention after 100?000 cycles). These results indicated that the highly conductive and electrochemically stable titanium oxynitride is an excellent candidate for use as an electrode material in high performance supercapacitors. PMID:24668150

Wang, Zhiqiang; Li, Zhaosheng; Feng, Jianyong; Yan, Shicheng; Luo, Wenjun; Liu, Jianguo; Yu, Tao; Zou, Zhigang

2014-05-14

44

An economical and environmentally friendly oxidative biaryl coupling promoted by activated MnO2.  

PubMed

An activated manganese dioxide (MnO2)-BF3OEt2 oxidation system was developed to efficiently mediate the intramolecular as well as intermolecular biaryl coupling. The oxidative coupling proceeds smoothly at ambient temperature to deliver the corresponding five- to eight-membered tricyclic products in good to excellent yields. The employment of the combination of MnO2 and BF3OEt2 is attractive on the basis of economical and environmental issues. PMID:25144866

Yang, Jingjing; Sun, Shutao; Zeng, Ziyu; Zheng, Hongbo; Li, Wei; Lou, Hongxiang; Liu, Lei

2014-10-21

45

Functionalization of biomass carbonaceous aerogels: selective preparation of MnO2@CA composites for supercapacitors.  

PubMed

Functionalized porous carbon materials with hierarchical structure and developed porosity coming from natural and renewable biomass have been attracting tremendous attention recently. In this work, we present a facile and scalable method to synthesize MnO2 loaded carbonaceous aerogel (MnO2@CA) composites via the hydrothermal carbonaceous (HTC) process. We employ two reaction systems of the mixed metal ion precursors to study the optimal selective adsorption and further reaction of MnO2 precursor on CA. Our experimental results show that the system containing KMnO4 and Na2S2O35H2O exhibits better electrochemical properties compared with the reaction system of MnSO4H2O and (NH4)2S2O8. For the former, the obtained MnO2@CA displays the specific capacitance of 123.5 Fg(-1). The enhanced supercapacitance of MnO2@CA nanocomposites could be ascribed to both electrochemical contributions of the loaded MnO2 nanoparticles and the porous structure of three-dimensional carbonaceous aerogels. This study not only indicates that it is vital for the reaction systems to match with porous carbonaceous materials, but also offers a new fabrication strategy to prepare lightweight and high-performance materials that can be used in energy storage devices. PMID:24882146

Ren, Yumei; Xu, Qun; Zhang, Jianmin; Yang, Hongxia; Wang, Bo; Yang, Daoyuan; Hu, Junhua; Liu, Zhimin

2014-06-25

46

Flexible ?-MnO2 paper formed by millimeter-long nanowires for supercapacitor electrodes  

NASA Astrophysics Data System (ADS)

High-quality ultra-long ?-MnO2 nanowires, with diameter of about 25nm and length of several hundred micrometers or even up to several millimeters, have been prepared using a simple hydrothermal approach without surfactants. By simple vacuum filtration, the superior flexible ?-MnO2 paper with adjustable thickness has been produced, and displays an average modulus of 225MPa at the thickness of 30?m. The crystallographic structure, chemical component and morphology of the ?-MnO2 nanowires are characterized by XRD, FTIR, XPS, FESEM and TEM, respectively. The influences of NH4+ ion concentration and temperature on the crystallographic forms, morphological changes and aspect ratios of the ?-MnO2 nanowires are systematically investigated. The as-prepared flexible ?-MnO2 paper electrode exhibits a high specific capacitance of 118Fg-1 at 2mVs-1 with excellent rate capability (42.4% at 200mVs-1), and a superior cycling stability with only 4.7% loss after 1000 cycles.

Yao, Wei; Wang, Jing; Li, Hao; Lu, Yun

2014-02-01

47

Facile synthesis of hierarchical hollow ?-MnO2 spheres and their application in supercapacitor electrodes  

NASA Astrophysics Data System (ADS)

The hierarchical hollow microspheres of ?-MnO2 have been synthesized through a facile chemical method at room temperature followed by selective removal of manganese carbonate structures with HCl. The microstructure and morphologies of the resulting materials are investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results indicate that the product obtained by simple reaction for 3 min has a porous shell with excellent permeability and uniform pore-size distribution. Electrochemical properties were characterized by cyclic voltammetry, galvanostatic charge/discharge and impedance spectra. As a result, the hierarchical hollow ?-MnO2 showed the specific capacitance of 115 F g-1 at 0.5 A g-1. These results demonstrate that the ?-MnO2 as electrode materials have potential application for high-performance supercapacitors.

Han, Dandan; Jing, Xiaoyan; Xu, Pengcheng; Ding, Yuansheng; Liu, Jingyuan

2014-10-01

48

Synthesis and characterization of whisker-shaped MnO2 nanostructure at room temperature  

NASA Astrophysics Data System (ADS)

Manganese dioxide nanoparticles have been synthesized, via a facile one-step solution phase approach, by the reduction of potassium permanganate with sodium thiosulphate at room temperature. Upon addition of thiosulphate to the solution of permanganate, a transparent dark-brown color species appeared which was stable for several months. The obtained MnO2 solution was characterized by means of UV-vis spectra, Transmission electron microscopy (TEM), and Fourier transforms infrared spectroscopy. Fourier transforms infrared spectroscopy spectra of pure MnO2 show the occurrence of O-Mn-O vibrational mode at around 600 and 475 cm-1. The chemical composition was obtained by EDX analysis and confirmed the presence of Mn and O in the sample. From the TEM image, the surface morphology of the sample shows uniformly dispersed particles, which are spherical in shape. The selected area electron diffraction patterns revealed that the MnO2 are crystalline in nature.

Jaganyi, Deogratius; Altaf, Mohammad; Wekesa, Isaac

2013-08-01

49

Charge tunneling and trapping in Er stabilized ?-MnO2 films for memory applications  

NASA Astrophysics Data System (ADS)

Recently, the memory effect was observed in Er stabilized ?-MnO2 metal oxide semiconductor structure. In this work, the electric properties and mechanism of charge tunneling and trapping are studied by combining frequency-dependent capacitance-voltage curves, variable sweep range capacitance-voltage curves, and current-voltage curves. The charge traps are identified to be deep donors in ?-MnO2. The deep donor level is close to the valance band, which results in the asymmetric enlargement in variable sweep range capacitance-voltage curves. Resonant tunneling and Fowler-Nordheim tunneling mechanisms are observed at low and high voltages, respectively. All these phenomena can be explained by the proposed model as a whole. The experimental evidence shows that Er-stabilized ?-MnO2 is a good candidate charge storage material in nonvolatile memory devices.

Cui, Jian; Ji, Ting; Nie, Tianxiao; Jiang, Zuimin

2014-06-01

50

Hydrothermal synthesis and characterization of orchid-like MnO 2 nanostructures  

NASA Astrophysics Data System (ADS)

Orchid-like Cr-doped MnO 2 nanostructures have been synthesized via a hydrothermal method, using KClO 3 as the oxidant. The as-obtained samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM). Results show that the morphologies of orchid-like MnO 2 are made up of nanorods. The influences of chromium in the solution on the morphology of the products are discussed. The electrochemical characterization was carried out by cyclic voltammetry, which indicated that the products were excellent electrode material for super-capacitor.

Li, Xueliang; Li, Wenjie; Chen, Xiangying; Shi, Chengwu

2006-12-01

51

Highly crystalline macroporous ?-MnO 2: Hydrothermal synthesis and application in lithium battery  

Microsoft Academic Search

A highly crystalline macroporous ?-MnO2 was hydrothermally synthesized using stoichiometric reaction between KMnO4 and MnCl2. The as-prepared material has a pore size of ca. 400nm and a shell thickness of 300500nm. The formation of the macroporous morphology is related to self-assembling from nanowires of ?-MnO2, and could be obtained at high reactant concentrations (e.g., 0.8M KMnO4) but not at low

Xingkang Huang; Dongping Lv; Qingshun Zhang; Haitao Chang; Jianlong Gan; Yong Yang

2010-01-01

52

Advanced Small Rechargeable Batteries  

NASA Technical Reports Server (NTRS)

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.

Halpert, Gerald

1989-01-01

53

A comparative DFT study of the catalytic activity of MnO2 (2 1 1) and (2-2-1) surfaces for an oxygen reduction reaction  

NASA Astrophysics Data System (ADS)

The catalytic activity of ?-MnO2 with high-index (2 1 1) and (2-2-1) surfaces for oxygen reduction (ORR) were studied using density functional theory (DFT). MnO2 (2-2-1) has a higher HOMO energy level and a higher electric conductivity than MnO2 (2 1 1). Thus, MnO2 (2-2-1) surface is more beneficial for electron transfer between the O2 and the catalyst. The calculation of the adsorption energies shows that the MnO2 (2 1 1) surface has a stronger interaction with the intermediate OH of the ORR than the MnO2 (2-2-1) surface. Therefore, the activity of MnO2 (2 1 1) is inferior to that of MnO2 (2-2-1) for ORR catalysis.

Li, Li; Wei, Zidong; Chen, Siguo; Qi, Xueqiang; Ding, Wei; Xia, Meirong; Li, Rong; Xiong, Kun; Deng, Zihua; Gao, Yuanyuan

2012-06-01

54

Rutile (?-)MnO2 surfaces and vacancy formation for high electrochemical and catalytic performance.  

PubMed

MnO2 is a technologically important material for energy storage and catalysis. Recent investigations have demonstrated the success of nanostructuring for improving the performance of rutile MnO2 in Li-ion batteries and supercapacitors and as a catalyst. Motivated by this we have investigated the stability and electronic structure of rutile (?-)MnO2 surfaces using density functional theory. A Wulff construction from relaxed surface energies indicates a rod-like equilibrium morphology that is elongated along the c-axis, and is consistent with the large number of nanowire-type structures that are obtainable experimentally. The (110) surface dominates the crystallite surface area. Moreover, higher index surfaces than considered in previous work, for instance the (211) and (311) surfaces, are also expressed to cap the rod-like morphology. Broken coordinations at the surface result in enhanced magnetic moments at Mn sites that may play a role in catalytic activity. The calculated formation energies of oxygen vacancy defects and Mn reduction at key surfaces indicate facile formation at surfaces expressed in the equilibrium morphology. The formation energies are considerably lower than for comparable structures such as rutile TiO2 and are likely to be important to the high catalytic activity of rutile MnO2. PMID:24446882

Tompsett, David A; Parker, Stephen C; Islam, M Saiful

2014-01-29

55

?-MnO2 as a cathode material for lithium ion batteries from first principles calculations.  

PubMed

The search for excellent cathodes for lithium batteries is the main topic in order to meet the requirements of low cost, high safety, and high capacity in many real applications. ?-MnO2, as a potential candidate, has attracted great attention because of its high stability and potential high capacity among all the phases. Because of the complexity of ?-MnO2, some fundamental questions at the atomic level during the charge-discharge process, remain unclear. The lithiation process of ?-MnO2 has been systematically examined by first-principles calculations along with cluster expansion techniques. Five stable configurations during the lithium intercalation process are firstly determined, and the electrochemical voltages are from 3.47 to 2.77 eV, indicating the strongly correlated effects of the ?-MnO2-LiMnO2 system. During the lithiation process, the changes in the lattice parameters are not symmetric. The analysis of electronic structures shows that Mn ions are in the mixed valence states of Mn(3+) and Mn(4+) during the lithiation process, which results in Jahn-Teller distortion in Mn(3+)O6 octahedra. Such results uncover the intrinsic origin of the asymmetric deformation during the charge-discharge process, resulting in the irreversible capacity fading during cycling. From the analysis of the thermal reduction of delithiated LixMnO2, the formation of oxygen is thermodynamically infeasible in the whole extraction process. Our results indicate that ?-MnO2 has great potential as a cathode material for high capacity Li-ion batteries. PMID:23646354

Wang, Da; Liu, Li-Min; Zhao, Shi-Jin; Li, Bai-Hai; Liu, Hao; Lang, Xiu-Feng

2013-06-21

56

Synthesis and property of novel MnO2@polypyrrole coaxial nanotubes as electrode material for supercapacitors  

NASA Astrophysics Data System (ADS)

Novel MnO2@polypyrrole (PPy) coaxial nanotubes have been prepared via a simple and green approach without any surfactant and additional oxidant. Under the acidic condition, MnO2 nanotubes act as both template and oxidant to initiate the polymerization of pyrrole monomers on its fresh-activated surface. Fourier transform infrared spectra (FT-IR), X-ray diffraction patterns (XRD), thermo-gravimetric analysis data (TG) and X-ray photoelectron spectra (XPS) suggest the formation of composite structure of MnO2@PPy. Also, FESEM and TEM images intuitively confirm that the PPy shell is coated uniformly on the surface of MnO2 nanotubes. Adjusting the concentrations of sulfuric acid or adding oxidant can modulate the morphology of the products accordingly. Due to the synergic effect between MnO2 core and PPy shell, the MnO2@PPy coaxial nanotubes possess better rate capability, larger specific capacitance of 380 F g-1, doubling the specific capacitance of MnO2 nanotubes, and good capacitance retention of 90% for its initial capacitance after 1000 cycles.

Yao, Wei; Zhou, Hui; Lu, Yun

2013-11-01

57

Synthesis and lithium ion insertion\\/extraction properties of hollandite-type MnO 2 prepared by acid digestion of Mn 2O 3  

Microsoft Academic Search

Single-phase specimens of ?-MnO2 (hollandite-type) and ?-MnO2 (rutile-type) were synthesized by the acid digestion of Mn2O3 under reflux conditions. The type of polymorph of MnO2 products was strongly dependent on the reaction temperature, type of acid used, and its concentration. The pH titration curve of ?-MnO2 displayed a monobasic acid behavior toward Li+, but ?-MnO2 showed a poor ion-exchange property.

Norihito Kijima; Yuko Sakata; Yasuhiko Takahashi; Junji Akimoto; Toshiya Kumagai; Kaoru Igarashi; Tadao Shimizu

2009-01-01

58

Sonochemically synthesized MnO2 nanoparticles as electrode material for supercapacitors.  

PubMed

In this study, manganese oxide (MnO2) nanoparticles were synthesized by sonochemical reduction of KMnO4 using polyethylene glycol (PEG) as a reducing agent as well as structure directing agent under room temperature in short duration of time and characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM), Transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) analysis. A supercapacitor device constructed using the ultrasonically-synthesized MnO2 nanoparticles showed maximum specific capacitance (SC) of 282Fg(-1) in the presence of 1M Ca(NO3)2 as an electrolyte at a current density of 0.5mAcm(-2) in the potential range from 0.0 to 1.0V and about 78% of specific capacitance was retained even after 1000 cycles indicating its high electrochemical stability. PMID:24360990

Gnana Sundara Raj, Balasubramaniam; Asiri, Abdullah M; Qusti, Abdullah H; Wu, Jerry J; Anandan, Sambandam

2014-11-01

59

In situ formation of ?-MnO2 nanowires as catalyst for sodium-air batteries  

NASA Astrophysics Data System (ADS)

Using a microwave-assisted path, MnO2 structures were prepared to be used as catalyst material in room-temperature-operated sodium-air cells. The electrochemical cells are prepared using a dry coating step (Laser Induced Forward Transfer), i.e. without organic solvents. Due to a novel formulation for an electrolyte, the electrochemical stability and performance of as-prepared electrodes is very high (1215Ah/kg specific charge).

Rosenberg, Sarah; Hintennach, Andreas

2015-01-01

60

Enhanced Tolerance to Stretch-Induced Performance Degradation of Stretchable MnO2-Based Supercapacitors.  

PubMed

The performance of many stretchable electronics, such as energy storage devices and strain sensors, is highly limited by the structural breakdown arising from the stretch imposed. In this article, we focus on a detailed study on materials matching between functional materials and their conductive substrate, as well as enhancement of the tolerance to stretch-induced performance degradation of stretchable supercapacitors, which are essential for the design of a stretchable device. It is revealed that, being widely utilized as the electrode material of the stretchable supercapacitor, metal oxides such as MnO2 nanosheets have serious strain-induced performance degradation due to their rigid structure. In comparison, with conducting polymers like a polypyrrole (PPy) film as the electrochemically active material, the performance of stretchable supercapacitors can be well preserved under strain. Therefore, a smart design is to combine PPy with MnO2 nanosheets to achieve enhanced tolerance to strain-induced performance degradation of MnO2-based supercapacitors, which is realized by fabricating an electrode of PPy-penetrated MnO2 nanosheets. The composite electrodes exhibit a remarkable enhanced tolerance to strain-induced performance degradation with well-preserved performance over 93% under strain. The detailed morphology and electrochemical impedance variations are investigated for the mechanism analyses. Our work presents a systematic investigation on the selection and matching of electrode materials for stretchable supercapacitors to achieve high performance and great tolerance to strain, which may guide the selection of functional materials and their substrate materials for the next-generation of stretchable electronics. PMID:25569836

Huang, Yan; Huang, Yang; Meng, Wenjun; Zhu, Minshen; Xue, Hongtao; Lee, Chun-Sing; Zhi, Chunyi

2015-02-01

61

MnO2 Nanorods Intercalating Graphene Oxide/Polyaniline Ternary Composites for Robust High-Performance Supercapacitors  

NASA Astrophysics Data System (ADS)

New ternary composites of MnO2 nanorods, polyaniline (PANI) and graphene oxide (GO) have been prepared by a two-step process. The 100 nm-long MnO2 nanorods with a diameter ~20 nm are conformably coated with PANI layers and fastened between GO layers. The MnO2 nanorods incorporated ternary composites electrode exhibits significantly increased specific capacitance than PANI/GO binary composite in supercapacitors. The ternary composite with 70% MnO2 exhibits a highest specific capacitance reaching 512 F/g and outstanding cycling performance, with ~97% capacitance retained over 5000 cycles. The ternary composite approach offers an effective solution to enhance the device performance of metal-oxide based supercapacitors for long cycling applications.

Han, Guangqiang; Liu, Yun; Zhang, Lingling; Kan, Erjun; Zhang, Shaopeng; Tang, Jian; Tang, Weihua

2014-04-01

62

Process dependent graphene-wrapped plate-like MnO2 nanospheres for high performance supercapacitor  

NASA Astrophysics Data System (ADS)

Two kinds of MnO2/graphene nanocomposites (M1 and M2) were synthesized by two different reaction procedures. M1 was synthesized as follows: the plate-like MnO2/graphene nanocomposite was obtained by using hydrazine reduction of MnO2/graphene oxide. M2 was formed as follows: the plate-like MnO2 nanospheres was synthesized on the graphene nanosheet which was reduced by hydrazine reduction of graphene oxide. The M1 have a good electrochemical performance and the average capacitance is as high as 250.6 F g-1 at 1 A g-1 in 1 mol L-1 Na2SO4 electrolyte, which is higher than that of the M2 (206.8 F g-1).

Liu, Chunliang; Gui, Dayong; Liu, Jianhong

2014-10-01

63

Aggregation kinetics of manganese dioxide colloids in aqueous solution: influence of humic substances and biomacromolecules.  

PubMed

In this work, the early stage aggregation kinetics of manganese dioxide (MnO2) colloids in aqueous solution and the effects of constituents of natural organic matter (i.e., Suwannee River fulvic acid (SRFA), Suwannee River humic acid (SRHA), alginate, and bovine serum albumin (BSA)) were investigated by time-resolved dynamic light scattering. MnO2 colloids were significantly aggregated in the presence of monovalent and divalent cations. The critical coagulation concentrations were 28, 0.8, and 0.45 mM for NaNO3, Mg(NO3)2, and Ca(NO3)2, respectively. The Hamaker constant of MnO2 colloids in aqueous solution was 7.84 10(-20) J. All the macromolecules tested slowed MnO2 colloidal aggregation rates greatly. The steric repulsive forces, originated from organic layers adsorbed on MnO2 colloidal surfaces, may be mainly responsible for their stabilizing effects. However, the complexes formed by alginate and Ca(2+) (>5 mM) might play a bridging role and thus enhanced MnO2 colloidal aggregation instead. These results may be important for assessing the fate and transport of MnO2 colloids and associated contaminants. PMID:23947796

Huangfu, Xiaoliu; Jiang, Jin; Ma, Jun; Liu, Yongze; Yang, Jing

2013-09-17

64

One-pot synthesis of MnO 2\\/graphene\\/carbon nanotube hybrid by chemical method  

Microsoft Academic Search

A branched hybrid of MnO2\\/graphene\\/carbon nanotube (CNT) is generated in a one-pot reaction process by chemical method. Some ultrathin MnO2\\/graphene nanosheets, around 5nm in thickness, are randomly distributed on the CNT surface. Morphology, phase structure, microstructure and vibrational properties of the hybrid were characterized by field emission scanning electron microscope, X-ray diffractometer, high resolution transmission electron microscope and Raman spectrometer.

Ying Chen; Yong Zhang; Dognsheng Geng; Ruying Li; Hanlie Hong; Jingzhong Chen; Xueliang Sun

2011-01-01

65

First-principles study of magnetism in spinel MnO2 Dane Morgan and Billie Wang  

E-print Network

First-principles study of magnetism in spinel MnO2 Dane Morgan and Billie Wang Department in spinel MnO2 . The magnetic interactions are mapped onto a Heisenberg model whose exchange interactions with experimental data. DOI: 10.1103/PhysRevB.67.134404 PACS number s : 75.10.Hk, 75.40.Mg I. INTRODUCTION Spinel Mn

Ceder, Gerbrand

66

Synthesis of mesoporous amorphous MnO 2 from SBA15 via surface modification and ultrasonic waves  

Microsoft Academic Search

Ultrasonic waves in combination with nanocasting method have been successfully used in preparation of mesoporous amorphous MnO2 from SBA-15. Modification of the intrachannel surfaces of SBA-15 with amino making them hydrophilic ensures precursor KMnO4 to readily penetrate the pore channels. Moreover, the modification changes the surface reactivity, enabling the formation of MnO2 inside the pores of SBA-15 by the sonochemical

Shenmin Zhu; Zhengyang Zhou; Di Zhang; Honghua Wang

2006-01-01

67

Rationally designed hierarchical MnO2-shell/ZnO-nanowire/carbon-fabric for high-performance supercapacitor electrodes  

NASA Astrophysics Data System (ADS)

High-performance supercapacitor electrodes with a novel hierarchical structure of MnO2/ZnO/carbon-fabric were rationally designed, and prepared by a simple three-step-solution method. The design comprises ZnO nanowires radially grown on each micron-size fiber of a carbon-fabric electrode, with a thin MnO2 shell on each ZnO nano-core. This multi-scale hierarchical structure yields: (a) high specific area of pseudo-capacitive MnO2 to maximize specific capacitance; (b) effective MnO2-electrolyte interface to facilitate fast charging/discharging; and (c) conductive MnO2-ZnO-electrode path to reduce energy loss. In addition, the overall capacitor performance is optimized by choosing proper thickness of MnO2 shell and aspect ratio of ZnO nano-core. The design was realized and validated with the development of a simple three-step-solution method: (a) radial deposition of nano-ZnO on carbon fabric; (b) coating ZnO by a thin layer of carbon; and (c) reduction of MnO4- and replacement of this carbon overlayer by MnO2. With this design and method, high specific capacitance of 886Fg-1 was found from electrodes with 5nm MnO2 on ZnO having an average diameter of 50nm and aspect ratio of 30. These samples showed specific energy of 16Whkg-1 and specific power of 27kWkg-1 at current density of 20mAcm-2, and good long-term cycling stability.

Yang, Q.; Zhang, X. T.; Zhang, M. Y.; Gao, Y.; Gao, H.; Liu, X. C.; Liu, H.; Wong, K. W.; Lau, W. M.

2014-12-01

68

MnO2 prepared by hydrothermal method and electrochemical performance as anode for lithium-ion battery  

PubMed Central

Two ?-MnO2 crystals with caddice-clew-like and urchin-like morphologies are prepared by the hydrothermal method, and their structure and electrochemical performance are characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), galvanostatic cell cycling, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). The morphology of the MnO2 prepared under acidic condition is urchin-like, while the one prepared under neutral condition is caddice-clew-like. The identical crystalline phase of MnO2 crystals is essential to evaluate the relationship between electrochemical performances and morphologies for lithium-ion battery application. In this study, urchin-like ?-MnO2 crystals with compact structure have better electrochemical performance due to the higher specific capacity and lower impedance. We find that the relationship between electrochemical performance and morphology is different when MnO2 material used as electrochemical supercapacitor or as anode of lithium-ion battery. For lithium-ion battery application, urchin-like MnO2 material has better electrochemical performance. PMID:24982603

2014-01-01

69

Nanoflaky MnO2/functionalized carbon nanotubes for supercapacitors: an in situ X-ray absorption spectroscopic investigation.  

PubMed

The surfaces of acid- and amine-functionalized carbon nanotubes (C-CNT and N-CNT) were decorated with MnO2 nanoflakes as supercapacitors by a spontaneous redox reaction. C-CNT was found to have a lower edge plane structure and fewer defect sites than N-CNT. MnO2/C-CNT with a highly developed surface area exhibited favorable electrochemical performance. To determine the atomic/electronic structures of the MnO2/functionalized CNTs (MnO2/C-CNT and MnO/N-CNT) during the charge/discharge process, in situ X-ray absorption spectroscopy (XAS) measurements were made at the Mn K-edge. Both C-CNT and N-CNT are highly conductive. The effect of the scan rate on the capacitance behavior was also examined, revealing that the ?* state of CNT and the size of the tunnels in pseudo-capacitor materials (which facilitate conduction and the transport of electrolyte ions) are critical for the capacitive performance, and their role depends on the scan rate. In the slow charge/discharge process, MnO2/N-CNT has a more symmetrical rectangular cyclic voltammetry (CV) curve. In the fast charge/discharge process, MnO2/C-CNT with a highly developed surface provides fast electronic and ionic channels that support a reversible faradaic redox reaction between MnO2 nanoflakes and the electrolyte, significantly enhancing its capacitive performance over that of MnO2/N-CNT. The MnO2/C-CNT architecture has great potential for supercapacitor applications. The information that was obtained herein helps to elucidate CNT surface modification and the design of the MnO2/functionalized CNT interface with a view for the further development of supercapacitors. This work, and especially the combination of CV with in situ XAS measurements, will be of value to readers with an interest in nanomaterial, nanotechnology and their applications in energy storage. PMID:25511126

Chang, Han-Wei; Lu, Ying-Rui; Chen, Jeng-Lung; Chen, Chi-Liang; Lee, Jyh-Fu; Chen, Jin-Ming; Tsai, Yu-Chen; Chang, Chien-Min; Yeh, Ping-Hung; Chou, Wu-Ching; Liou, Ya-Hsuan; Dong, Chung-Li

2015-01-22

70

First-Principles Calculations of Oxygen Vacancy Formation and Metallic Behavior at a ?-MnO2 Grain Boundary.  

PubMed

Nanostructured MnO2 is renowned for its excellent energy storage capability and high catalytic activity. While the electronic and structural properties of MnO2 surfaces have received significant attention, the properties of the grain boundaries (GBs) and their contribution to the electrochemical performance of the material remains unknown. Through density functional theory (DFT) calculations, the structure and electronic properties of the ?-MnO2 ? 5(210)/[001] GB are studied. Our calculations show this low energy GB has a significantly reduced band gap compared to the pristine material and that the formation of oxygen vacancies produces spin-polarized states that further reduce the band gap. Calculated formation energies of oxygen vacancy defects and Mn reduction at the GB core are all lower than the equivalent bulk value and in some cases lower than values recently calculated for ?-MnO2 surfaces. Oxygen vacancy formation is also shown to produce a metallic behavior at the GB with defect charge distributed over a number of oxygen and manganese sites. The low energies of oxygen defect formation and the potential creation of conductive GB pathways are likely to be important to the electrochemical performance of ?-MnO2. PMID:25559707

Dawson, James A; Chen, Hungru; Tanaka, Isao

2015-01-28

71

A facile one-pot hydrothermal synthesis of ?-MnO2 nanopincers and their catalytic degradation of methylene blue  

NASA Astrophysics Data System (ADS)

Branched ?-MnO2 bipods with novel nanopincer morphology were prepared by a facile one-pot hydrothermal method via a redox reaction between NaClO3 and MnSO4 in sulfuric acid solution without using any surfactants or templates. The products were characterized in detail by various techniques including X-ray powder diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, surface area analyzer, field emission scanning electron microscopy and transmission electron microscopy. Results show that the obtained ?-MnO2 nanopincers consist of two sharp nanorods with a diameter of 100-200 nm and a length of 1-2 ?m. The concentration of H2SO4 solution plays an important role in controlling the crystal phase and morphology of the final product. A possible formation mechanism for the ?-MnO2 nanopincers was proposed. Moreover, these ?-MnO2 nanostructures exhibited better catalytic performance than the commercial MnO2 particles to decompose methyl blue (MB) in the presence of H2O2.

Cheng, Gao; Yu, Lin; Lin, Ting; Yang, Runnong; Sun, Ming; Lan, Bang; Yang, Lili; Deng, Fangze

2014-09-01

72

Nanoflaky MnO2/functionalized carbon nanotubes for supercapacitors: an in situ X-ray absorption spectroscopic investigation  

NASA Astrophysics Data System (ADS)

The surfaces of acid- and amine-functionalized carbon nanotubes (C-CNT and N-CNT) were decorated with MnO2 nanoflakes as supercapacitors by a spontaneous redox reaction. C-CNT was found to have a lower edge plane structure and fewer defect sites than N-CNT. MnO2/C-CNT with a highly developed surface area exhibited favorable electrochemical performance. To determine the atomic/electronic structures of the MnO2/functionalized CNTs (MnO2/C-CNT and MnO/N-CNT) during the charge/discharge process, in situ X-ray absorption spectroscopy (XAS) measurements were made at the Mn K-edge. Both C-CNT and N-CNT are highly conductive. The effect of the scan rate on the capacitance behavior was also examined, revealing that the ?* state of CNT and the size of the tunnels in pseudo-capacitor materials (which facilitate conduction and the transport of electrolyte ions) are critical for the capacitive performance, and their role depends on the scan rate. In the slow charge/discharge process, MnO2/N-CNT has a more symmetrical rectangular cyclic voltammetry (CV) curve. In the fast charge/discharge process, MnO2/C-CNT with a highly developed surface provides fast electronic and ionic channels that support a reversible faradaic redox reaction between MnO2 nanoflakes and the electrolyte, significantly enhancing its capacitive performance over that of MnO2/N-CNT. The MnO2/C-CNT architecture has great potential for supercapacitor applications. The information that was obtained herein helps to elucidate CNT surface modification and the design of the MnO2/functionalized CNT interface with a view for the further development of supercapacitors. This work, and especially the combination of CV with in situ XAS measurements, will be of value to readers with an interest in nanomaterial, nanotechnology and their applications in energy storage.The surfaces of acid- and amine-functionalized carbon nanotubes (C-CNT and N-CNT) were decorated with MnO2 nanoflakes as supercapacitors by a spontaneous redox reaction. C-CNT was found to have a lower edge plane structure and fewer defect sites than N-CNT. MnO2/C-CNT with a highly developed surface area exhibited favorable electrochemical performance. To determine the atomic/electronic structures of the MnO2/functionalized CNTs (MnO2/C-CNT and MnO/N-CNT) during the charge/discharge process, in situ X-ray absorption spectroscopy (XAS) measurements were made at the Mn K-edge. Both C-CNT and N-CNT are highly conductive. The effect of the scan rate on the capacitance behavior was also examined, revealing that the ?* state of CNT and the size of the tunnels in pseudo-capacitor materials (which facilitate conduction and the transport of electrolyte ions) are critical for the capacitive performance, and their role depends on the scan rate. In the slow charge/discharge process, MnO2/N-CNT has a more symmetrical rectangular cyclic voltammetry (CV) curve. In the fast charge/discharge process, MnO2/C-CNT with a highly developed surface provides fast electronic and ionic channels that support a reversible faradaic redox reaction between MnO2 nanoflakes and the electrolyte, significantly enhancing its capacitive performance over that of MnO2/N-CNT. The MnO2/C-CNT architecture has great potential for supercapacitor applications. The information that was obtained herein helps to elucidate CNT surface modification and the design of the MnO2/functionalized CNT interface with a view for the further development of supercapacitors. This work, and especially the combination of CV with in situ XAS measurements, will be of value to readers with an interest in nanomaterial, nanotechnology and their applications in energy storage. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr06439a

Chang, Han-Wei; Lu, Ying-Rui; Chen, Jeng-Lung; Chen, Chi-Liang; Lee, Jyh-Fu; Chen, Jin-Ming; Tsai, Yu-Chen; Chang, Chien-Min; Yeh, Ping-Hung; Chou, Wu-Ching; Liou, Ya-Hsuan; Dong, Chung-Li

2015-01-01

73

Nanotubular MnO2/graphene oxide composites for the application of open air-breathing cathode microbial fuel cells.  

PubMed

Nanotubular shaped ?-MnO2/graphene oxide nanocomposites were synthesized via a simple, cost and time efficient hydrothermal method. The growth of hollow structured MnO2 nanotubes preferentially occurred along the [001] direction as evidenced from the morphological and structural characterizations. The tunnels of ?-MnO2 nanotubes easily accommodated the molecular oxygen and exhibited excellent catalytic activity towards the oxygen reduction reaction over the rod structure and was further enhanced with the effective carbon support graphene oxide. The MnO2 nanotubes/graphene oxide nanocomposite modified electrode exhibited a maximum power density of 3359 mW m(-2) which is 7.8 fold higher than that of unmodified electrode and comparable with the Pt/C modified electrode. The microbial fuel cell equipped with MnO2 nanotubes/graphene oxide nanocomposite modified cathode exhibited quick start up and excellent durability over the studied electrodes and is attributed to the high surface area and number of active sites. These findings not only provide the fundamental studies on carbon supported low-dimensional transition-metal oxides but also open up the new possibilities of their applications in green energy devices. PMID:24240107

Gnana Kumar, G; Awan, Zahoor; Suk Nahm, Kee; Xavier, J Stanley

2014-03-15

74

The theoretical study on electronic structure and electromagnetic properties of ?-MnO2 based on crystal defects  

NASA Astrophysics Data System (ADS)

First-principles calculations based on density functional theory (DFT) have been carried out to investigate the effects of crystal defects (intrinsic vacancy defects and ion doping) on the microwave dielectric response and the correlative electromagnetic properties of ?-MnO2 systematically. The possible role of crystal defects in electromagnetic performance is studied utilizing density of states (DOS) and the bond length between the manganese and oxygen. Lattice distortion is induced by the introduction of crystal defects. The spin-electronic DOS demonstrates that Ni doping enhances the spin-polarization of MnO2, which indicates that the Ni-doped MnO2 possesses certain magnetic characteristic, which is helpful for magnetic loss. The emergence of a new defect mode, contributes to the relaxation polarization phenomenon, so as to enhance the dielectric loss ability. In addition, through the change of the bond length and pseudo gap width, it can be learned that the bond strength and covalency of Mn-O bonds are weakened, which increases the dielectric loss of MnO2. The results throw light on the exploration of theoretical research on the microwave absorbing properties of MnO2 with crystal defects.

Duan, Yuping; Chen, Junlei; Zhang, Yahong; Wang, Tongmin

2014-12-01

75

Oxygen vacancy formation and reduction properties of ?-MnO2 grain boundaries and the potential for high electrochemical performance.  

PubMed

In recent years, the nanostructuring of rutile (?-)MnO2 has been shown to vastly improve its properties and performance in a number of technological applications. The contrast between the strong electrochemical properties of the nanostructured material and the bulk material that shows limited Li intercalation and electrochemical capacitance is not yet fully understood. In this work, we investigate the structure, stability and catalytic properties of four tilt grain boundaries in ?-MnO2 using interatomic potential methods. By considering the ?-surfaces of each of the grain boundaries, we are able to find the lowest energy configurations for each grain boundary structure. For each grain boundary, we observe a significant decrease in the oxygen vacancy energies in and around the grain boundaries compared to bulk ?-MnO2 and also the bulk-like structures in the grain boundary cells. The reduction of Mn(4+) to Mn(3+) is also considered and again is shown to be preferable at the boundaries. These energies suggest a potentially higher catalytic activity at the grain boundaries of ?-MnO2. The results are also placed into context with recent calculations of ?-MnO2 surfaces to produce a more detailed understanding into this important phenomenon. PMID:25247793

Dawson, James A; Tanaka, Isao

2014-10-22

76

Facile preparation of three-dimensional multilayer porous MnO2/reduced graphene oxide composite and its supercapacitive performance  

NASA Astrophysics Data System (ADS)

Three-dimensional (3D) multilayer porous MnO2/reduced graphene oxide composites are coated on a nickel foam substrate (denoted as MnO2/R-GO@Ni-foam) by a facile and scalable spray method following by low temperature annealing. The composite electrodes are characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. The content of MnO2 in the MnO2/R-GO@Ni-foam composites is determined by thermal gravimetric analysis. The supercapacitive performance of the composite electroides is investigated by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The results show that the MnO2/R-GO@Ni-foam composite displays a high specific capacitance of 267Fg-1 at 0.25Ag-1 and excellent capacitance retention of 89.5% after 1000 cycles. This study provides a facile way for the preparation of composite electrodes for high-performance supercapacitor.

Li, Yiju; Wang, Guiling; Ye, Ke; Cheng, Kui; Pan, Yue; Yan, Peng; Yin, Jinling; Cao, Dianxue

2014-12-01

77

Three-dimensional MnO2 nanowire/ZnO nanorod arrays hybrid nanostructure for high-performance and flexible supercapacitor electrode  

NASA Astrophysics Data System (ADS)

Pure MnO2 nanowires and MnO2 nanowire/ZnO nanorod array hybrid nanostructure grown on carbon cloth are synthesized through a low temperature solution method for flexible and high performance supercapacitor applications. The MnO2 nanowire/ZnO nanorod hybrid nanostructured electrodes exhibit more than two times higher specific capacitance, and better capacitance retention than those of pure MnO2 nanowire electrodes. For the three-dimensional MnO2 nanowire/ZnO nanorod array hybrid electrode, a high specific capacitance of 746.7Fg-1 (areal capacitance ?41.5mFcm-2) is obtained at a scan rate of 2mVs-1, while the specific capacitance of pure MnO2 nanowire electrode is 319.6Fg-1. The electrochemical impedance spectroscopy measurements also confirm MnO2 nanowire/ZnO nanorod array hybrid electrode has better electrochemical character. The MnO2 nanowire/ZnO nanorod array hybrid electrode shows great cycle stability, it only losses 6.5% of the initial capacitance after 1000cycles. The energy density and power density of the hybrid electrode at 2Ag-1 are 63.1Whkg-1 and 950Wkg-1, respectively. It is illustrated that the electrochemical performance of MnO2 nanowire electrode has been greatly enhanced with the supporting of ZnO nanorod arrays.

Li, Songzhan; Wen, Jian; Mo, Xiaoming; Long, Hao; Wang, Haoning; Wang, Jianbo; Fang, Guojia

2014-06-01

78

Some clues about the interphase reaction between ZnO and MnO 2 oxides  

NASA Astrophysics Data System (ADS)

Raman spectroscopy is used to evidence both the nature of the interphase reaction between ZnO and MnO 2 particles and its kinetic evolution. Zn cations migrate from the ZnO grains during oxygen vacancies formation process and diffuse into the MnO 2 particles leading to an interphase region with an intermediate valence Mn +3-O-Mn +4. Large amounts of desorbed Zn cations promote the formation of ZnMn 2O 4 structure, in addition to the intermediate valence state. The system evolves towards complete formation of the spinel phase at higher thermal treatment times. The reactivity of the ZnO plays an important role in the formation of this interphase. Low-reactivity ZnO powder, in which the oxygen vacancies are previously produced, shows a stabilization of the intermediate valence state with very limited formation of the spinel phase. A clear correlation between the amount of the intermediate state interphase and the magnetic properties has been established.

Rubio-Marcos, F.; Quesada, A.; Garca, M. A.; Baares, M. A.; Fierro, J. L. G.; Martn-Gonzalez, M. S.; Costa-Krmer, J. L.; Fernndez, J. F.

2009-05-01

79

MnO2 -Modified Persistent Luminescence Nanoparticles for Detection and Imaging of Glutathione in Living Cells and In Vivo.  

PubMed

Persistent luminescence nanoparticles (PLNPs) hold great promise for the detection and imaging of biomolecules. Herein, we have demonstrated a novel nanoprobe, based on the manganese dioxide (MnO2 )-modified PLNPs, that can detect and image glutathione in living cells and in vivo. The persistent luminescence of the PLNPs can be efficiently quenched by the MnO2 nanosheets. In the presence of glutathione (GSH), MnO2 was reduced to Mn(2+) and the luminescence of PLNPs can be restored. The persistent luminescence property can allow detection and imaging without external excitation and avoid the background noise originating from the in situ excitation. This strategy can offer a promising platform for detection and imaging of reactive species in living cells or in vivo. PMID:25352246

Li, Na; Diao, Wei; Han, Yaoyao; Pan, Wei; Zhang, Tingting; Tang, Bo

2014-12-01

80

The LiMn 2O 4 to ?-MnO 2 phase transition studied by in situ neutron diffraction  

Microsoft Academic Search

The LixMn2O4 to ?-MnO2 phase transition, as lithium is extracted electrochemically from the spinel structure, has been studied by in situ neutron diffraction. The single-phase composition around 4.1 V is found to be strongly dependent on potential, with the Li content (x) varying between 0.65(9) and 0.49(12). The amount of Li in the cubic ?-MnO2 phase is 0.27(13) with cell

Helena Berg; Hkan Rundlv; John O Thomas

2001-01-01

81

Characterization and electrochemical performance of the spinel LiMn 2O 4 prepared from ?-MnO 2  

Microsoft Academic Search

The preparation and characterization of the spinel LiMn2O4 obtained by solid state reaction from quasi-amorphous ?-MnO2 is reported. A well-defined highly pure spinel was characterized from X-ray diffractograms. The average manganese valence of ?-MnO2 and spinel samples was found to be 3.890.01 and 3.590.01, respectively. The electrochemical performance of the spinel was evaluated through cyclic voltammetry and chronopotentiometry. The voltammetric

Luiz C Ferracin; Fbio A Amaral; Nerilso Bocchi

2000-01-01

82

Aqueous rechargeable lithium battery (ARLB) based on LiV 3O 8 and LiMn 2O 4 with good cycling performance  

Microsoft Academic Search

Crystalline LiV3O8 and LiMn2O4 were prepared by conventional solid-state reaction and characterized by X-ray diffraction analysis. Cyclic voltammetry technique was employed to evaluate the electrochemical behaviors of LiV3O8 and LiMn2O4 in 2mol\\/l Li2SO4 aqueous solution, and the results show that both LiV3O8 and LiMn2O4 are very stable in this aqueous electrolyte and can be used as the negative and positive

G. J. Wang; H. P. Zhang; L. J. Fu; B. Wang; Y. P. Wu

2007-01-01

83

Stable Isotope Fractionation during Chromium(III) Oxidation by ?-MnO2  

NASA Astrophysics Data System (ADS)

Hexavalent chromium is a highly mobile anthropogenic pollutant, and reduction of Cr(VI) to the less-soluble Cr(III) is the most important natural process involved in contamination attenuation. Earlier work has shown a preferential reduction of lighter Cr stable isotopes attributed to a kinetically-controlled mechanism, and isotope ratio measurements may be used as indicators of Cr(VI) reduction [1]. Recent work has detected no significant isotope exchange between dissolved Cr(III) and Cr(VI) over a period of days to weeks, and has suggested that complex bidirectional reactions control fractionation during Cr(III) oxidation by H2O2 [2]. Previous studies on oxidation by pyrolusite (?-MnO2) have reported ?53/52Cr up to approximately +1.1 in the Cr(VI) product [3]. However, laboratory investigations of fractionation during Cr(III) oxidation by birnessite (?-MnO2) have been inconclusive, and oxidation mechanisms remain unclear [4]. In order to fully exploit stable isotope fractionation during redox reactions of Cr in groundwater as an indicator of Cr attenuation, the effect of Cr(III) oxidation on isotope ratios must be better understood. We will report the latest measurements of isotope fractionation during oxidation on birnessite under varying pH and MnO2 and Cr(III) concentrations. Our preliminary findings (at initial Cr(III) and ?-MnO2 concentrations of 10 mg/L and 100 mg/L, respectively) show the Cr(VI) product shifted by -0.5 to +0.0 relative to the reactant at pH ? 4.5. The reaction is incomplete and plateaus within 60 min. Unlike that observed with pyrolusite, fractionation during Cr oxidation on birnessite is much smaller or absent. These initial results suggest that kinetic effects are either very small or are negated by back reaction or equilibration in the multi-step oxidation mechanism. Alternatively, in our experiments, a step involving little isotope fractionation may be rate-limiting; thus, the final magnitude of isotope fractionation during oxidation on birnessite could vary if the rate-limiting step changes. Additional experiments at different conditions will aid in the elucidation of fractionating mechanisms during Cr(III) oxidation. [1] Ellis, A. S.; Johnson, T. M.; Bullen, T. D. (2002) Science, 295(5562), 2060 [2] Zink, S.; Schoenberg, R.; Staubwasser, M. (2010) Geochim. Cosmochim. Acta, in press [3] Ellis, A. S.; Johnson, T. M.; Villalobos-Aragon, A.; Bullen, T. D. (2008) Eos Trans. AGU, 89(53), Fall Meet. Suppl., Abstract H53F-08 [4] Bain, D. J.; Bullen, T. D. (2005) Geochim. Cosmochim. Acta, 69(10), Suppl. 1, A212

Wang, D. T.; Fregoso, D. C.; Ellis, A. S.; Johnson, T. M.; Bullen, T. D.

2010-12-01

84

Hydrothermal-assisted synthesis of the Na7V4(P2O7)4(PO4)/C nanorod and its fast sodium intercalation chemistry in aqueous rechargeable sodium batteries  

NASA Astrophysics Data System (ADS)

Both high safety and low cost give aqueous rechargeable sodium-ion batteries (ARSB) the opportunity for application in stationary energy storage, but the low operating potential of the existing cathode materials limits its energy density. Here, we introduce a hydrothermal-assisted strategy to prepare the Na7V4(P2O7)4(PO4)/C nanorod and employ it as a novel high-property cathode material for ARSB. The hierarchical structure is formed by direct in situ carbonization of the surfactants (CTAB and oxalic acid) along with the crystallization of Na7V4(P2O7)4(PO4). The prepared Na7V4(P2O7)4(PO4) with a well-defined 1D nanostructure and uniform particle size is wrapped with a thin carbon layer. For the first time, its sodium intercalation chemistry in an aqueous electrolyte was investigated. Based on the reversible phase transformation and high sodium diffusion coefficient, it is demonstrated to be reliable in an aqueous electrolyte with the rapid ion transport capability. A pair of redox plateaus is observed in the charge and discharge curves at 0.961 and 0.944 V (vs. SCE) respectively with the capacity of 51.2 mA h g-1 at 80 mA g-1. Favored by the open ion channel and 1D morphology, the composite exhibits superior high rate capability and 72% of the capacity remains at 1000 mA g-1. The results not only demonstrate a high-property cathode material for ARSB, but also are helpful for design and synthesis of mixed-polyanion electrode materials with tailored architecture.Both high safety and low cost give aqueous rechargeable sodium-ion batteries (ARSB) the opportunity for application in stationary energy storage, but the low operating potential of the existing cathode materials limits its energy density. Here, we introduce a hydrothermal-assisted strategy to prepare the Na7V4(P2O7)4(PO4)/C nanorod and employ it as a novel high-property cathode material for ARSB. The hierarchical structure is formed by direct in situ carbonization of the surfactants (CTAB and oxalic acid) along with the crystallization of Na7V4(P2O7)4(PO4). The prepared Na7V4(P2O7)4(PO4) with a well-defined 1D nanostructure and uniform particle size is wrapped with a thin carbon layer. For the first time, its sodium intercalation chemistry in an aqueous electrolyte was investigated. Based on the reversible phase transformation and high sodium diffusion coefficient, it is demonstrated to be reliable in an aqueous electrolyte with the rapid ion transport capability. A pair of redox plateaus is observed in the charge and discharge curves at 0.961 and 0.944 V (vs. SCE) respectively with the capacity of 51.2 mA h g-1 at 80 mA g-1. Favored by the open ion channel and 1D morphology, the composite exhibits superior high rate capability and 72% of the capacity remains at 1000 mA g-1. The results not only demonstrate a high-property cathode material for ARSB, but also are helpful for design and synthesis of mixed-polyanion electrode materials with tailored architecture. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr05175k

Deng, Chao; Zhang, Sen; Wu, Yongxin

2014-12-01

85

Recovery of MnO2 from a spent alkaline battery leach solution via ozone treatment  

NASA Astrophysics Data System (ADS)

This work investigates the reaction rate of Mn(II) to generate solid manganese dioxide (MnO2) as a function of the gaseous ozone mass flow rate (27.5-77gh-1). The experimental studies were carried out in a semi-continuous reactor, using a synthetic solution (300mL of 1M H2SO4 with 6000ppm of Mn(II) added as MnSO4) that simulated the composition of an acid leaching solution from spent alkaline battery material (SBM). It was observed that at 1.3-1.45V/SHE and pH<1.0 a selective formation of MnO2 powder was obtained; at values greater than 1.45V/SHE, permanganate ion (MnO41-) was formed. On the other hand, a linear relation was perceived between the volumetric mass transfer coefficient (kLa) and the ozone mass flow rate (19.3-77gh-1 in 600mL of the 1M H2SO4 solution). The rate constant (k) was determined in the presence and absence of nonporous plastic spheres (D=3mm). In both cases the rate of Mn(II) conversion increased proportionally with the ozone mass flow rate, although the conversions obtained with non-porous plastic spheres (x=82%) were always higher than those without non-porous plastic spheres (x=72%). A pseudo-homogenous mass transfer model adequately approximated the experimental data.

Cruz-Daz, Martn R.; Arauz-Torres, Yennifer; Caballero, Francisco; Lapidus, Gretchen T.; Gonzlez, Ignacio

2015-01-01

86

Synthesis of MnO2-graphene composites with enhanced supercapacitive performance via pulse electrodeposition under supergravity field  

NASA Astrophysics Data System (ADS)

A method of pulse electrodeposition under supergravity field was proposed to synthesize MnO2-graphene composites. Supergravity is very efficient for promoting mass transfer and decreasing concentration polarization during the electrodeposition process. The synthesis was conducted on our homemade supergravity equipment. The strength of supergravity field depended on the rotating speed of the ring electrode. 3D flower like MnO2 spheres composed of nanoflakes were acquired when the rotating speed was 3000 rpm. Graphene nanosheets play as a role of conductive substrates for MnO2 growing. The composites are evaluated as electrode materials for supercapacitors. Electrochemical results show that the maximum specific capacitance of the MnO2-graphene composite is 595.7 F g-1 at a current density of 0.5 A g-1. In addition, the composite exhibits excellent cycle stability with no capacitance attenuation after 1000 cycles. The approach provides new ideas for developing supercapacitor electrode materials with high performance.

Liu, Tingting; Shao, Guangjie; Ji, Mingtong; Wang, Guiling

2014-07-01

87

Hydrothermal-assisted synthesis of the Na7V4(P2O7)4(PO4)/C nanorod and its fast sodium intercalation chemistry in aqueous rechargeable sodium batteries.  

PubMed

Both high safety and low cost give aqueous rechargeable sodium-ion batteries (ARSB) the opportunity for application in stationary energy storage, but the low operating potential of the existing cathode materials limits its energy density. Here, we introduce a hydrothermal-assisted strategy to prepare the Na7V4(P2O7)4(PO4)/C nanorod and employ it as a novel high-property cathode material for ARSB. The hierarchical structure is formed by direct in situ carbonization of the surfactants (CTAB and oxalic acid) along with the crystallization of Na7V4(P2O7)4(PO4). The prepared Na7V4(P2O7)4(PO4) with a well-defined 1D nanostructure and uniform particle size is wrapped with a thin carbon layer. For the first time, its sodium intercalation chemistry in an aqueous electrolyte was investigated. Based on the reversible phase transformation and high sodium diffusion coefficient, it is demonstrated to be reliable in an aqueous electrolyte with the rapid ion transport capability. A pair of redox plateaus is observed in the charge and discharge curves at 0.961 and 0.944 V (vs. SCE) respectively with the capacity of 51.2 mA h g(-1) at 80 mA g(-1). Favored by the open ion channel and 1D morphology, the composite exhibits superior high rate capability and 72% of the capacity remains at 1000 mA g(-1). The results not only demonstrate a high-property cathode material for ARSB, but also are helpful for design and synthesis of mixed-polyanion electrode materials with tailored architecture. PMID:25407134

Deng, Chao; Zhang, Sen; Wu, Yongxin

2014-12-11

88

MnO2@KCu7S4 NWs hybrid compositions for high-power all-solid-state supercapacitor  

NASA Astrophysics Data System (ADS)

Here we present a high-power all-solid-state supercapacitor based on a novel structure of MnO2@KCu7S4 NWs. The electrodes exhibit excellent electrochemical performance with large specific capacitance of 533Fg-1 and the maximum power density 2.02kWkg-1, still hold 85% of the capacitance over 6000 cycles. Besides, we also explored the effect of temperature on the capacitance. When compared with capacitance at different temperatures, the specific capacity at 80C demonstrates significantly higher. Moreover, two supercapacitors in series can power 41 light-emitting diodes (LEDs) about 4min. These results suggest that such MnO2@KCu7S4 hybrid composite is promising for next generation high-performance supercapacitors.

Dai, Shuge; Xi, Yi; Hu, Chenguo; Yue, Xule; Cheng, Lu; Wang, Guo

2015-01-01

89

The morphology and electromagnetic properties of MnO 2 obtained in 8 T high magnetic field  

NASA Astrophysics Data System (ADS)

MnO 2 powder was synthesized in a high magnetic field (8 T) via a simple route, and the formation mechanism for the grain shape was discussed. The synthesized samples were characterized by XRD, SEM, TEM, and vector network analysis. The morphology of synthesized MnO 2 was sea urchin-like ball chain with a low density center, just like "hollow-like". Throughout the whole frequency range, the dielectric constant and the loss tangent clearly decreased in 8 T high magnetic field. Moreover, the magnetic permeability and the loss tangent increased slightly in the frequency range 2-13 GHz. Furthermore, the theoretically calculated values of reflection loss showed that when the magnetic field strength 8 T was adopted, the absorption peak became smoother and shifted to a higher frequency.

Jia, Zhang; Yuping, Duan; Hui, Jing; Xiaogang, Li; Shunhua, Liu

2010-09-01

90

Oxidative transformation of levofloxacin by ?-MnO2: Products, pathways and toxicity assessment.  

PubMed

The characteristics of the oxidative transformation of the antibiotic levofloxacin (abbreviated as LEV) by manganese oxide were investigated. Up to 91% of LEV were removed with an equivalent of 200units (abbreviated as equiv) of manganese oxide within a 35-day treatment period. A total of ten transformation products were identified, and five of them were newly reported. A tentative transformation pathway of LEV in the manganese oxide system involving oxidation and dealkylation was proposed. In addition, the variation in the genotoxicity and antibacterial activity along with the treatment by manganese oxide were traced using a SOS/umu assay and Escherichia coli growth inhibition assay, respectively. The results indicated that the genotoxicity significantly decreased in response to treatment with manganese oxide, while the antibacterial activity was not markedly affected until 160-equiv of ?-MnO2 were added. This study suggests that the oxidative degradation of LEV by manganese oxide can play an important role in the natural attenuation of LEV in sediment or soil matrices. The transformation reaction may be further optimized for removing quinolone antibiotics from wastewater or other environmental matrices to reduce the potential risk. PMID:25036942

Li, Yuan; Wei, Dongbin; Du, Yuguo

2015-01-01

91

BSA-templated MnO2 nanoparticles as both peroxidase and oxidase mimics.  

PubMed

Inorganic nanomaterials that mimic enzymes are fascinating as they potentially have improved properties relative to native enzymes, such as greater resistance to extremes of pH and temperature and lower sensitivity to proteases. Although many artificial enzymes have been investigated, searching for highly-efficient and stable catalysts is still of great interest. In this paper, we first demonstrated that bovine serum albumin (BSA)-stabilized MnO(2) nanoparticles (NPs) exhibited highly peroxidase-, oxidase-, and catalase-like activities. The activities of the BSA-MnO(2) NPs were evaluated using the typical horseradish peroxidase (HRP) substrates o-phenylenediamine (OPD) and 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of either hydrogen peroxide or dissolved oxygen. These small-sized BSA-MnO(2) NPs with good dispersion, solubility and biocompatibility exhibited typical Michaelis-Menten kinetics and high affinity for H(2)O(2), OPD and TMB, indicating that BSA-MnO(2) NPs can be used as satisfactory enzyme mimics. Based on these findings, BSA-MnO(2) NPs were used as colorimetric immunoassay tags for the detection of goat anti-human IgG in place of HRP. The colorimetric immunoassay using BSA-MnO(2) NPs has the advantages of being fast, robust, inexpensive, easily prepared and with no HRP and H(2)O(2) being needed. These water-soluble BSA-MnO(2) NPs may have promising potential applications in biotechnology, bioassays, and biomedicine. PMID:22900262

Liu, Xing; Wang, Qi; Zhao, Huihui; Zhang, Lichun; Su, Yingying; Lv, Yi

2012-10-01

92

Morphology-controlled synthesis and novel microwave electromagnetic properties of hollow urchin-like chain Fe-doped MnO 2 under 10 T high magnetic field  

NASA Astrophysics Data System (ADS)

Fe-doped MnO 2 with a hollow sea urchin-like ball chain shape was first synthesized under a high magnetic field of 10 T. The formation mechanism was investigated and discussed in detail. The synthesized samples were characterized by XRD, SEM, TEM, EMPA, and vector network analysis. By doping MnO 2 with Fe, the relative complex permittivity of MnO 2 and its corresponding loss tangent clearly decreases, but its relative complex permeability and its corresponding loss tangent markedly increases. Moreover, the theoretically calculated values of reflection loss show that with increasing the Fe content, the as-prepared Fe-doped MnO 2 exhibits good microwave absorption capability.

Yuping, Duan; Jia, Zhang; Hui, Jing; Shunhua, Liu

2011-05-01

93

Multifunctional free-standing membrane from the self-assembly of ultralong MnO2 nanowires.  

PubMed

In this work, we report the preparation of a free-standing membrane with strong mechanical stability and flexibility through a facile vacuum filtration approach. A field-emission scanning electron microscopy image demonstrates that the membrane composed of MnO2 nanowires is 50 nm in width and up to 100 ?m long and the nanowires are assembled in parallel into bundles. A possible formation mechanism for the ultralong nanowires and the free-standing membrane has been proposed. Meanwhile, the properties of the membrane could be controlled by incorporating different materials to achieve composite membranes. In order to demonstrate the broad applicability of the MnO2 membrane, we fabricate a variety of composite membranes exhibiting various novel properties including magnetism and reversibly switchable wettability between hydrophilicity and hydrophobicity through various material modification, including CoFe2O4 nanoparticles and organic triethoxy(octyl)silane. Furthermore, the free-standing membrane could also simultaneously be functionalized with two materials, which reveal multiple properties. The synthesis method of a free-standing MnO2 membrane is simple and environmentally friendly, and it is easily scalable for industry. These composite membranes constitute a significant contribution to advanced technology. PMID:23815464

Lan, Bang; Yu, Lin; Lin, Ting; Cheng, Gao; Sun, Ming; Ye, Fei; Sun, Qingfeng; He, Jun

2013-08-14

94

Surface modification of spinel ?-MnO2 and its lithium adsorption properties from spent lithium ion batteries  

NASA Astrophysics Data System (ADS)

Spinel ?-MnO2 ion-sieves are promising materials because of their high selectivity toward lithium ions, and this can be applied to the recovery of lithium from spent lithium ion batteries. However, manganese dissolution loss during the delithiation of LiMn2O4 causes a decrease in adsorption capacity and poor cycling stability for these ion-sieves. To improve the lithium adsorption properties of ?-MnO2 ion-sieves, surface modification with a CeO2 coating was studied using hydrothermal-heterogeneous nucleation. The structure, morphology and composition of the synthesized materials were determined by XRD, SEM, TEM and EDS. The effect of hydrothermal synthesis conditions and the amount of CeO2 coating on the adsorption performance of ?-MnO2 were also investigated. A 0.5 wt.% CeO2-coated ion-sieve was synthesized by heating at 120 C for 3 h and it had better adsorption properties than the bare samples. The effect of ultrasonic treatment on the lithium extraction ratio from LiMn2O4 upon acid treatment at various temperatures was studied and the results were compared with conventional mechanical stirring. We found that ultrasonic treatment at lower temperature gave almost the same maximum lithium extraction ratio and was more efficient and economic.

Li, Li; Qu, Wenjie; Liu, Fang; Zhao, Taolin; Zhang, Xiaoxiao; Chen, Renjie; Wu, Feng

2014-10-01

95

Electrochemically grown nanoporous MnO2 nanowalls on a porous carbon substrate with enhanced capacitance through faster ionic and electrical mobility.  

PubMed

We report the deposition of uniform porous MnO2 nanowalls on a conducting carbon fiber substrate using a simple electrochemical method, which produces ordered nano-channels demarcated by the MnO2 walls for easy ion transport and a continuous electron path created by the carbon backbone. The system achieves a specific capacitance of 1149 F g(-1) and retains 565 F g(-1) even at dragging conditions as high as 100 A g(-1). PMID:24865591

Anothumakkool, Bihag; Kurungot, Sreekumar

2014-07-11

96

PVP-Assisted ZrO2 coating on LiMn2O4 spinel cathode nanoparticles prepared by MnO2 nanowire templates  

E-print Network

PVP-Assisted ZrO2 coating on LiMn2O4 spinel cathode nanoparticles prepared by MnO2 nanowire July 2008 Accepted 15 July 2008 Available online 19 July 2008 Keywords: Spinel Cathode Li-ion Mn dissolution Cycle life Rate capability a b s t r a c t LiMn2O4 spinel nanorods prepared from nanowire MnO2

Cho, Jaephil

97

Recharge unit provides for optimum recharging of battery cells  

NASA Technical Reports Server (NTRS)

Percent recharge unit permits each cell of a rechargeable battery to be charged to a preset capacity of the cell. The unit automatically monitors and controls a rechargeable battery subjected to charge-discharge cycling tests.

Baer, D.; Ford, F. E.

1968-01-01

98

Predicting heavy metals' adsorption edges and adsorption isotherms on MnO2 with the parameters determined from Langmuir kinetics.  

PubMed

Although surface complexation models have been widely used to describe the adsorption of heavy metals, few studies have verified the feasibility of modeling the adsorption kinetics, edge, and isotherm data with one pH-independent parameter. A close inspection of the derivation process of Langmuir isotherm revealed that the equilibrium constant derived from the Langmuir kinetic model, KS-kinetic, is theoretically equivalent to the adsorption constant in Langmuir isotherm, KS-Langmuir. The modified Langmuir kinetic model (MLK model) and modified Langmuir isotherm model (MLI model) incorporating pH factor were developed. The MLK model was employed to simulate the adsorption kinetics of Cu(II), Co(II), Cd(II), Zn(II) and Ni(II) on MnO2 at pH3.2 or 3.3 to get the values of KS-kinetic. The adsorption edges of heavy metals could be modeled with the modified metal partitioning model (MMP model), and the values of KS-Langmuir were obtained. The values of KS-kinetic and KS-Langmuir are very close to each other, validating that the constants obtained by these two methods are basically the same. The MMP model with KS-kinetic constants could predict the adsorption edges of heavy metals on MnO2 very well at different adsorbent/adsorbate concentrations. Moreover, the adsorption isotherms of heavy metals on MnO2 at various pH levels could be predicted reasonably well by the MLI model with the KS-kinetic constants. PMID:25597679

Hu, Qinghai; Xiao, Zhongjin; Xiong, Xinmei; Zhou, Gongming; Guan, Xiaohong

2015-01-01

99

The effects of high magnetic field on the morphology and microwave electromagnetic properties of MnO 2 powder  

NASA Astrophysics Data System (ADS)

MnO 2 with a sea urchin-like ball chain shape was first synthesized in a high magnetic field via a simple chemical process, and a mechanism for the formation of this grain shape was discussed. The as-synthesized samples were characterized by XRD, SEM, TEM, and vector network analysis. The dielectric constant and the loss tangent clearly decreased under a magnetic field. The magnetic loss tangent and the imaginary part of the magnetic permeability increased substantially. Furthermore, the theoretically calculated values of reflection loss showed that the absorption peaks shifted to a higher frequency with increases in the magnetic field strength.

Zhang, Jia; Yuping, Duan; Shuqing, Li; Xiaogang, Li; Shunhua, Liu

2010-07-01

100

Structure-property relationship of bifunctional MnO2 nanostructures: highly efficient, ultra-stable electrochemical water oxidation and oxygen reduction reaction catalysts identified in alkaline media.  

PubMed

Manganese oxides of various structures (?-, ?-, and ?-MnO2 and amorphous) were synthesized by facile methods. The electrocatalytic properties of these materials were systematically investigated for catalyzing both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) in alkaline media. Extensive characterization was correlated with the activity study by investigating the crystal structures (XRD, HRTEM), morphologies (SEM), porosities (BET), surfaces (XPS, O2-TPD/MS), and electrochemical properties (Tafel analysis, Koutechy-Levich plots, and constant-current electrolysis). These combined results show that the electrocatalytic activities are strongly dependent on the crystallographic structures, and follow an order of ?-MnO2 > AMO > ?-MnO2 > ?-MnO2. Both OER studies and ORR studies reveal similar structure-determined activity trends in alkaline media. In the OER studies, ?-MnO2 displays an overpotential of 490 mV compared to 380 mV shown by an Ir/C catalyst in reaching 10 mA cm(-2). Meanwhile, ?-MnO2 also exhibits stability for 3 h when supplying a constant current density of 5 mA cm(-2). This was further improved by adding Ni(2+) dopants (ca. 8 h). The superior OER activity was attributed to several factors, including abundant di-?-oxo bridges existing in ?-MnO2 as the protonation sites, analogous to the OEC in PS-II of the natural water oxidation system; the mixed valencies (AOS = 3.7); and the lowest charge transfer resistances (91.8 ?, ? = 430 mV) as revealed from in situ electrochemical impedance spectroscopy (EIS). In the ORR studies, when reaching 3 mA cm(-2), ?-MnO2 shows 760 mV close to 860 mV for the best ORR catalyst (20% Pt/C). The outstanding ORR activity was due to the strongest O2 adsorption capability of ?-MnO2 suggested by temperature-programmed desorption. As a result, this discovery of the structure-related electrocatalytic activities could provide guidance in the further development of easily prepared, scalable, and low-cost catalysts based on metal oxides and their derivatives. PMID:25058174

Meng, Yongtao; Song, Wenqiao; Huang, Hui; Ren, Zheng; Chen, Sheng-Yu; Suib, Steven L

2014-08-13

101

Rechargeable battery powered electric car and recharging station therefor  

Microsoft Academic Search

The invention discloses a rechargeable battery powered electric vehicle comprising an electric motor powered by a rechargeable storage battery in combination with a recharging station comprising extendible electrodes for supplying recharging power for the vehicle's storage battery, the vehicle comprising a charging circuit connected to the battery with one lead grounded to the vehicle body and one lead connected to

Rose; W. R. II

1979-01-01

102

Self-Assembly of Mesoporous Nanotubes Assembled from Interwoven Ultrathin Birnessite-type MnO2 Nanosheets for Asymmetric Supercapacitors  

PubMed Central

Porous nanotubes comprised of MnO2 nanosheets were fabricated with a one-pot hydrothermal method using polycarbonate membrane as the template. The diameter and thickness of nanotubes can be controlled by choice of the membrane pore size and the chemistry. The porous MnO2 nanotubes were used as a supercapacitor electrode. The specific capacitance in a three-electrode system was 365?F g?1 at a current density of 0.25?A g?1 with capacitance retention of 90.4% after 3000 cycles. An asymmetric supercapacitor with porous MnO2 nanotubes as the positive electrode and activated graphene as the negative electrode yielded an energy density of 22.5?Wh kg?1 and a maximum power density of 146.2?kW kg?1; these values exceeded those reported for other MnO2 nanostructures. The supercapacitor performance was correlated with the hierarchical structure of the porous MnO2 nanotubes. PMID:24464344

Huang, Ming; Zhang, Yuxin; Li, Fei; Zhang, Lili; Ruoff, Rodney S.; Wen, Zhiyu; Liu, Qing

2014-01-01

103

Self-Assembly of Mesoporous Nanotubes Assembled from Interwoven Ultrathin Birnessite-type MnO2 Nanosheets for Asymmetric Supercapacitors  

NASA Astrophysics Data System (ADS)

Porous nanotubes comprised of MnO2 nanosheets were fabricated with a one-pot hydrothermal method using polycarbonate membrane as the template. The diameter and thickness of nanotubes can be controlled by choice of the membrane pore size and the chemistry. The porous MnO2 nanotubes were used as a supercapacitor electrode. The specific capacitance in a three-electrode system was 365 F g-1 at a current density of 0.25 A g-1 with capacitance retention of 90.4% after 3000 cycles. An asymmetric supercapacitor with porous MnO2 nanotubes as the positive electrode and activated graphene as the negative electrode yielded an energy density of 22.5 Wh kg-1 and a maximum power density of 146.2 kW kg-1 these values exceeded those reported for other MnO2 nanostructures. The supercapacitor performance was correlated with the hierarchical structure of the porous MnO2 nanotubes.

Huang, Ming; Zhang, Yuxin; Li, Fei; Zhang, Lili; Ruoff, Rodney S.; Wen, Zhiyu; Liu, Qing

2014-01-01

104

Effect of P2O5 and MnO2 on crystallization of magnetic glass ceramics  

PubMed Central

This work pointed out the effect of adding P2O5 and/or MnO2 on the crystallization behavior of magnetic glass ceramic in the system Fe2O3ZnOCaOSiO2B2O3. The differential thermal analysis of the quenched samples revealed decrease in the thermal effects by adding P2O5 and/or MnO2 to the base sample. The X-ray diffraction patterns show the development of nanometric magnetite crystals in a glassy matrix. Heat treatment at 800C for 2h, under reducing atmosphere, caused an increase in the amount of the crystallized magnetite with the appearance of minor hematite and Ca2SiO4. The transmission electron microscope revealed a crystallite size in the range 1030nm. Magnetic hysteresis cycles were analyzed with a maximum applied field of 25kOe at room temperature. The prepared magnetic glass ceramics are expected to be useful for localized treatment of cancer.

Abdel-Hameed, Salwa A.M.; Marzouk, Mohamed A.; Farag, Mohamed M.

2013-01-01

105

Leaching and separation of zinc from the black paste of spent MnO2-Zn dry cell batteries.  

PubMed

Spent batteries represent a source of hazardous materials when discarded without appropriate treatment. Investigations on the recovery of zinc from the black paste of spent MnO(2)-Zn cell batteries were carried out. Leaching of zinc and manganese from the black paste of spent batteries using sulfuric or hydrochloric acid solutions was studied. It was found that leaching with sulfuric acid solution is more efficient than with HCl solution. Different parameters affecting the leaching of Zn(II) and Mn(II) with sulfuric acid were further studied. Extraction of Zn(II) and Mn(II) from the leaching sulfate medium by bis(2,4,4-trimethylpentyl) dithiophosphinic acid (CYANEX 301) diluted with kerosene was investigated. The factors affecting the extraction process, separately studied, include the effect of contact time, sulfuric acid concentration, CYANEX 301 concentration, phase ratio as well as temperature. The results indicated that, from sulfate medium, Zn(II) is more extracted than Mn(II). Selective stripping of Zn(II) was obtained using 5M HCl. Application of the method on the leaching sulfate solution of the spent MnO(2)-Zn dry cell black paste show the efficiency of the process, where the extraction and stripping of Zn(II) are 98% and 99%, respectively. PMID:17049161

El-Nadi, Y A; Daoud, J A; Aly, H F

2007-05-01

106

Controlled partial-exfoliation of graphite foil and integration with MnO2 nanosheets for electrochemical capacitors.  

PubMed

Here we demonstrate a controlled two-step partial exfoliation method to synthesize functionalized exfoliated graphite substrates. Ultrathin and functionalized graphene sheets anchoring on the graphite provide a large conductive surface area for loading pseudo-capacitive MnO2 nanosheets. The functionalized exfoliated graphite/MnO2 electrode achieved an excellent areal capacitance of 244 mF cm(-2), corresponding to an estimated MnO2 based gravimetric capacitance of 1061 F g(-1), which is just slightly lower than its theoretical value of 1110 F g(-1). More importantly, the seamless integration of graphene sheets and the graphite substrate minimizes the contact resistance, and substantially improves the rate capability of pseudo-capacitive materials. The electrode retained 44.8% of its capacitance when the charging current density increased 50 times from 0.23 to 11.5 mA cm(-2). This novel functionalized exfoliated graphite substrate serves as a promising supporting material that could address the relatively low electrical conductivity of various pseudo-capacitive materials, and increase the mass loading and rate capability of pseudo-capacitors. PMID:25631619

Song, Yu; Feng, Dong-Yang; Liu, Tian-Yu; Li, Yat; Liu, Xiao-Xia

2015-02-12

107

Constraints on the utility of MnO2 cartridge method for the extraction of radionuclides: A case study using 234Th  

USGS Publications Warehouse

[1] Large volume (102-103 L) seawater samples are routinely processed to investigate the partitioning of particle reactive radionuclides and Ra between solution and size-fractionated suspended particulate matter. One of the most frequently used methods to preconcentrate these nuclides from such large volumes involves extraction onto three filter cartridges (a prefilter for particulate species and two MnO2-coated filters for dissolved species) connected in series. This method assumes that the extraction efficiency is uniform for both MnO2-coated cartridges, that no dissolved species are removed by the prefilter, and that any adsorbed radionuclides are not desorbed from the MnO2-coated cartridges during filtration. In this study, we utilized 234Th-spiked coastal seawater and deionized water to address the removal of dissolved Th onto prefilters and MnO2-coated filter cartridges. Experimental results provide the first data that indicate (1) a small fraction of dissolved Th (<6%) can be removed by the prefilter cartridge; (2) a small fraction of dissolved Th (<5%) retained by the MnO2 surface can also be desorbed, which undermines the assumption of uniform extraction efficiency for Th; and (3) the absolute and relative extraction efficiencies can vary widely. These experiments provide insight on the variability of the extraction efficiency of MnO 2-coated filter cartridges by comparing the relative and absolute efficiencies and recommend the use of a constant efficiency on the combined activity from two filter cartridges connected in series for future studies of dissolved 234Th and other radionuclides in natural waters using sequential filtration/extraction methods. ?? 2009 by the American Geophysical Union.

Baskaran, M.; Swarzenski, P.W.; Biddanda, B.A.

2009-01-01

108

Rechargeability and economic aspects of alkaline zinc-manganese dioxide cells for electrical storage and load leveling  

NASA Astrophysics Data System (ADS)

Batteries based on manganese dioxide (MnO2) cathodes are good candidates for grid-scale electrical energy storage, as MnO2 is low-cost, relatively energy dense, safe, water-compatible, and non-toxic. Alkaline Zn-MnO2 cells, if cycled at reduced depth of discharge (DOD), have been found to achieve substantial cycle life with battery costs projected to be in the range of 100 to 150 per kWh (delivered). Commercialization of rechargeable Zn-MnO2 batteries has in the past been hampered due to poor cycle life. In view of this, the work reported here focuses on the long-term rechargeability of prismatic MnO2 cathodes at reduced DOD when exposed to the effects of Zn anodes and with no additives or specialty materials. Over 3000 cycles is shown to be obtainable at 10% DOD with energy efficiency >80%. The causes of capacity fade during long-term cycling are also investigated and appear to be mainly due to the formation of irreversible manganese oxides in the cathode. Analysis of the data indicates that capacity loss is rapid in the first 250 cycles, followed by a regime of stability that can last for thousands of cycles. A model has been developed that captures the behavior of the cells investigated using measured state of charge (SOC) data as input. An approximate economic analysis is also presented to evaluate the economic viability of Zn-MnO2 batteries based on the experiments reported here.

Ingale, Nilesh D.; Gallaway, Joshua W.; Nyce, Michael; Couzis, Alexander; Banerjee, Sanjoy

2015-02-01

109

Effect of synthesis duration on the morphological and structural modification of the sea-urchin nanostructured -MnO2 and study of its  

E-print Network

Effect of synthesis duration on the morphological and structural modification of the sea-urchin Abstract Single crystalline nanorods and sea-urchin like morphology of the -MnO2 nanostructures were at different synthesizing temperature and different oxidizing agents. The products were presented as the sea-urchin

Boyer, Edmond

110

High loading MnO2 nanowires on graphene paper: Facile electrochemical synthesis and use as flexible electrode for tracking hydrogen peroxide secretion in live cells.  

PubMed

Recent progress in flexible and lightweight electrochemical sensor systems requires the development of paper-like electrode materials. Here, we report a facile and green synthesis of a new type of MnO2 nanowires-graphene nanohybrid paper by one-step electrochemical method. This strategy demonstrates a collection of unique features including the effective electrochemical reduction of graphene oxide (GO) paper and the high loading of MnO2 nanowires on electrochemical reduced GO (ERGO) paper. When used as flexible electrode for nonenzymatic detection of hydrogen peroxide (H2O2), MnO2-ERGO paper exhibits high electrocatalytic activity toward the redox of H2O2 as well as excellent stability, selectivity and reproducibility. The amperometric responses are linearly proportional to H2O2 concentration in the range 0.1-45.4mM, with a detection limit of 10?M (S/N=3) and detection sensitivity of 59.0?Acm(-2)mM(-1). These outstanding sensing performances enable the practical application of MnO2-ERGO paper electrode for the real-time tracking H2O2 secretion by live cells macrophages. Therefore, the proposed graphene-based nanohybrid paper electrode with intrinsic flexibility, tailorable shapes and adjustable properties can contribute to the full realization of high-performance flexible electrode material used in point-of-care testing devices and portable instruments for in-vivo clinical diagnostics and on-site environmental monitoring. PMID:25467459

Dong, Shuang; Xi, Jiangbo; Wu, Yanan; Liu, Hongwei; Fu, Chaoyang; Liu, Hongfang; Xiao, Fei

2015-01-01

111

Hierarchical NiCo2O4@MnO2 core-shell heterostructured nanowire arrays on Ni foam as high-performance supercapacitor electrodes.  

PubMed

An advanced integrated electrode for high-performance supercapacitors has been designed by growing hierarchical NiCo(2)O(4)@MnO(2) core-shell heterostructured nanowire arrays on nickel foam. Such unique array nanoarchitectures exhibit remarkable electrochemical performance with high capacitance and desirable cycle life at high rates. PMID:23169236

Yu, Le; Zhang, Genqiang; Yuan, Changzhou; Lou, Xiong Wen David

2013-01-01

112

Facile synthesis of hierarchical Co3O4@MnO2 core-shell arrays on Ni foam for asymmetric supercapacitors  

NASA Astrophysics Data System (ADS)

Hierarchical Co3O4@MnO2 core-shell arrays on Ni foam have been fabricated by a facile hydrothermal approach and further investigated as the electrode for high-performance supercapacitors. Owing to the high conductivity of the well-defined mesoporous Co3O4 nanowire arrays in combination with the large surface area provided by the ultrathin MnO2 nanosheets, the unique designed Co3O4@MnO2 core-shell arrays on Ni foam have exhibited a high specific capacitance (560Fg-1 at a current density of 0.2Ag-1), good rate capability, and excellent cycling stability (95% capacitance retention after 5000cycles). An asymmetric supercapacitor with Co3O4@MnO2 core-shell nanostructure as the positive electrode and activated microwave exfoliated graphite oxide activated graphene (MEGO) as the negative electrode yielded an energy density of 17.7Whkg-1 and a maximum power density of 158kWkg-1. The rational design of the unique core-shell array architectures demonstrated in this work provides a new and facile approach to fabricate high-performance electrode for supercapacitors.

Huang, Ming; Zhang, Yuxin; Li, Fei; Zhang, Lili; Wen, Zhiyu; Liu, Qing

2014-04-01

113

DNA-assisted assembly of carbon nanotubes and MnO2 nanospheres as electrodes for high-performance asymmetric supercapacitors.  

PubMed

A DNA-assisted assembly approach is developed to fabricate a capacitor-type electrode material, DNA-functionalized carbon nanotubes (CNTs@DNA), and a battery-type electrode material, DNA@CNTs-bridged MnO2 spheres (CNTs@DNA-MnO2), for asymmetric supercapacitors. An energy density of 11.6 W h kg(-1) is achieved at a power density of 185.5 W kg(-1) with a high MnO2 mass loading of 4.2 mg cm(-2). It is found that DNA assembly plays a critical role in the enhanced supercapacitor performance. This is because while DNA molecules functionalize carbon nanotubes (CNTs) via ?-? stacking, their hydrophilic sugar-phosphate backbones also promote the dispersion of CNTs. The resultant CNTs@DNA chains can link multiple MnO2 spheres to form a networked architecture that facilitates charge transfer and effective MnO2 utilization. The improved performance of the asymmetric supercapacitors indicates that DNA-assisted assembly offers a promising approach to the fabrication of high-performance energy storage devices. PMID:24469241

Guo, Chun Xian; Chitre, Amey Anil; Lu, Xianmao

2014-03-14

114

Low-Cost High-Performance Solid-State Asymmetric Supercapacitors Based on MnO2 Nanowires and Fe2O3 Nanotubes  

E-print Network

Low-Cost High-Performance Solid-State Asymmetric Supercapacitors Based on MnO2 Nanowires and Fe2O3 and Nanosystems, Chinese Academy of Sciences, Beijing, China *S Supporting Information ABSTRACT: A low-cost high, the facile scalable fabrication of low-cost high-performance solid-state flexible ASCs still remains

Wang, Zhong L.

115

Improvement in the etching performance of the acrylonitrile-butadiene-styrene resin by MnO2-H3PO4-H2SO4 colloid.  

PubMed

The present study aimed to evaluate the surface etching of the acrylonitrile-butadiene-styrene (ABS) resin in the MnO2-H3PO4-H2SO4 colloid. To enhance the soluble Mn(IV) ion concentration and improve the etching performance of ABS resin, H3PO4 was added as a complexing agent into the MnO2-H2SO4 etching system. The effects of the H2SO4 concentration and etching time on the surface topography, surface roughness, adhesion strength, and the surface chemistry of the ABS substrates were investigated. The optimal oxidation potentials of MnO2 in the colloids decreased from 1.426 to 1.369 V with the addition of H3PO4. Though the etching conditions changed from 70 C for 20 min to 60 C for 10 min, the adhesion strength between the ABS substrates and electroless copper film increased from 1.19 to 1.33 KN/m after etching treatment. This could be attributed to the significant increase of the soluble Mn(IV) ion concentration in the MnO2-H3PO4-H2SO4 colloid. The surface chemistry results demonstrated that the oxidation reaction of -C?C- bonds in the polybutadiene phase was accelerated in the etching process by the addition of H3PO4, and the abundant -COOH and -OH groups were formed rapidly on the ABS surface with the etching treatment. These results were in agreement with the results of surface scanning electron microscopic observations and adhesion strength measurement. The results suggested that the MnO2-H3PO4-H2SO4 colloid was an effective surface etching system for the ABS surface roughness. PMID:23611532

Zhao, Wenxia; Ding, Jie; Wang, Zenglin

2013-05-21

116

Electrophoretic deposition of TiO2 and composite TiO2-MnO2 films using benzoic acid and phenolic molecules as charging additives.  

PubMed

Electrophoretic deposition (EPD) method has been developed for the fabrication of TiO(2) and MnO(2) films. Benzoic acid and phenolic molecules, such as 4-hydroxybenzoic acid, 3,5-dihydroxybenzoic acid, gallic acid, salicylic acid and salicylic acid sodium salt were investigated as charging additives for the EPD of TiO(2) and MnO(2) particles. The deposition yield has been studied as a function of the additive concentration and deposition time for cathodic deposits obtained from the suspensions, containing benzoic acid, 4-hydroxybenzoic acid, 3,5-dihydroxybenzoic acid and anodic deposits prepared from the suspensions, containing gallic acid and salicylic acid sodium salt. The results obtained for the phenolic molecules with different number of OH groups were analyzed and compared with corresponding experimental data for benzoic acid without OH groups. The adjacent OH groups, as well as adjacent OH and COOH groups bonded to the aromatic ring of the phenolic molecules were beneficial for adsorption of the molecules on oxide particles. The adsorption mechanisms involved the interaction of COOH groups and OH groups of the organic molecules with metal ions on the particle surfaces and complexation. Gallic acid was shown to be an effective charging additive, which provided stabilization of TiO(2) and MnO(2) particles in the suspensions and enabled their deposition. It was shown that composite TiO(2)-MnO(2) films can be obtained using gallic acid as a common dispersing agent for TiO(2) and MnO(2). The Ti/Mn ratio in the composite films was varied in the range of 0-1.3. The thickness of the films was varied in the range of 0-10 ?m. The mechanisms of particle charging and deposition were discussed. PMID:20850128

Wu, K; Wang, Y; Zhitomirsky, I

2010-12-15

117

The Exxon rechargeable cells  

NASA Astrophysics Data System (ADS)

The design and performance of ambient temperature secondary cells based on the titanium disulfide cathode are discussed. These limited performance products were developed for microelectronic applications such as solar rechargeable watches and clocks which require low drain rate and do not require many deep cycles.

Malachesky, P. A.

1980-04-01

118

REMOTELY RECHARGEABLE EPD  

SciTech Connect

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.

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

2007-11-13

119

Rechargeable Magnesium Power Cells  

NASA Technical Reports Server (NTRS)

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.

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

1995-01-01

120

Low-temperature molar heat capacities and entropies of MnO2 (pyrolusite), Mn3O4 (hausmanite), and Mn2O3 (bixbyite)  

USGS Publications Warehouse

Pyrolusite (MnO2), hausmanite (Mn3O4), and bixbyite (Mn2O3), are important ore minerals of manganese and accurate values for their thermodynamic properties are desirable to understand better the {p(O2), T} conditions of their formation. To provide accurate values for the entropies of these important manganese minerals, we have measured their heat capacities between approximately 5 and 380 K using a fully automatic adiabatically-shielded calorimeter. All three minerals are paramagnetic above 100 K and become antiferromagnetic or ferrimagnetic at lower temperatures. This transition is expressed by a sharp ??-type anomaly in Cpmo for each compound with Ne??el temperatures TN of (92.2??0.2), (43.1??0.2), and (79.45??0.05) K for MnO2, Mn3O4, and Mn2O3, respectively. In addition, at T ??? 308 K, Mn2O3 undergoes a crystallographic transition, from orthorhombic (at low temperatures) to cubic. A significant thermal effect is associated with this change. Hausmanite is ferrimagnetic below TN and in addition to the normal ??-shape of the heat-capacity maxima in MnO2 and Mn2O3, it has a second rounded maximum at 40.5 K. The origin of this subsidiary bump in the heat capacity is unknown but may be related to a similar "anomalous bump" in the curve of magnetization against temperature at about 39 K observed by Dwight and Menyuk.(1) At 298.15 K the standard molar entropies of MnO2, Mn3O4, and Mn2O3, are (52.75??0.07), (164.1??0.2), and (113.7??0.2) J??K-1??mol-1, respectively. Our value for Mn3O4 is greater than that adopted in the National Bureau of Standards tables(2) by 14 per cent. ?? 1985.

Robie, R.A.; Hemingway, B.S.

1985-01-01

121

Water Table Fluctuations Induced by Intermittent Recharge  

Microsoft Academic Search

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;

Marinus Maasland

1959-01-01

122

All-solid-state electrochemical capacitors using MnO2 electrode/SiO2-Nafion electrolyte composite prepared by the sol-gel process  

NASA Astrophysics Data System (ADS)

Electrode-electrolyte composites of MnO2 active material, acetylene black (AB), and SiO2-Nafion solid electrolyte were prepared using the sol-gel process to form good solid-solid interfaces. The composites were obtained by the addition of MnO2 and AB into a sol of hydrolyzed tetraethoxysilane with Nafion, and successive solidification of the precursor sol. Scanning electron microscope and energy dispersive X-ray spectroscopy measurements show that good solid-solid interface is formed between electrodes and solid electrolytes in the composites. All-solid-state hybrid capacitors were fabricated using the composites or the hand-grinding mixture of MnO2, AB and SiO2-Nafion powder as positive electrodes, activated carbon powder as a negative electrode, and phosphosilicate gel as a solid electrolyte. The all-solid-state hybrid capacitors using the composites exhibit larger capacitances and better rate performance than the capacitors using the electrode prepared by hand-mixing of powders. Specific discharge capacitances of the capacitor with the composite are 85Fg-1 for the one with the composite electrode and 48Fg-1 for the one with the hand-mixed electrode, at 1mAcm-2. Moreover, the all-solid-state capacitors using the composite electrode can be operated at temperatures between-30C and 60C.

Shimamoto, Kazushi; Tadanaga, Kiyoharu; Tatsumisago, Masahiro

2014-02-01

123

Long-term cycling behavior of asymmetric activated carbon\\/MnO 2 aqueous electrochemical supercapacitor  

Microsoft Academic Search

Activated carbonMnO2 hybrid electrochemical supercapacitor cells have been assembled and characterized in K2SO4 aqueous media. A laboratory cell achieved 195,000 cycles with stable performance. The maximal cell voltage was 2V associated with 212Fg?1 of total composite electrode materials (including activated carbon and MnO2, binder and conductive additive) and an equivalent serie resistance (ESR) below 1.3?cm2. Long-life cycling was achieved by

Thierry Brousse; Pierre-Louis Taberna; Olivier Crosnier; Romain Dugas; Philippe Guillemet; Yves Scudeller; Yingke Zhou; Frdric Favier; Daniel Blanger; Patrice Simon

2007-01-01

124

FLUIDIC: Metal Air Recharged  

ScienceCinema

Fluidic, with the help of ARPA-E funding, has developed and deployed the world's first proven high cycle life metal air battery. Metal air technology, often used in smaller scale devices like hearing aids, has the lowest cost per electron of any rechargeable battery storage in existence. Deploying these batteries for grid reliability is competitive with pumped hydro installations while having the advantages of a small footprint. Fluidic's battery technology allows utilities and other end users to store intermittent energy generated from solar and wind, as well as maintain reliable electrical delivery during power outages. The batteries are manufactured in the US and currently deployed to customers in emerging markets for cell tower reliability. As they continue to add customers, they've gained experience and real world data that will soon be leveraged for US grid reliability.

Friesen, Cody

2014-04-02

125

FLUIDIC: Metal Air Recharged  

SciTech Connect

Fluidic, with the help of ARPA-E funding, has developed and deployed the world's first proven high cycle life metal air battery. Metal air technology, often used in smaller scale devices like hearing aids, has the lowest cost per electron of any rechargeable battery storage in existence. Deploying these batteries for grid reliability is competitive with pumped hydro installations while having the advantages of a small footprint. Fluidic's battery technology allows utilities and other end users to store intermittent energy generated from solar and wind, as well as maintain reliable electrical delivery during power outages. The batteries are manufactured in the US and currently deployed to customers in emerging markets for cell tower reliability. As they continue to add customers, they've gained experience and real world data that will soon be leveraged for US grid reliability.

Friesen, Cody

2014-03-07

126

Prototype systems for rechargeable magnesium batteries.  

PubMed

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 hindered by two problems. First, owing to the chemical activity of Mg, only solutions that neither donate nor accept protons are suitable as electrolytes; but most of these solutions allow the growth of passivating surface films, which inhibit any electrochemical reaction. Second, the choice of cathode materials has been limited by the difficulty of intercalating Mg ions in many hosts. Following previous studies of the electrochemistry of Mg electrodes in various non-aqueous solutions, and of a variety of intercalation electrodes, we have now developed rechargeable Mg battery systems that show promise for applications. The systems comprise electrolyte solutions based on Mg organohaloaluminate salts, and Mg(x)Mo3S4 cathodes, into which Mg ions can be intercalated reversibly, and with relatively fast kinetics. We expect that further improvements in the energy density will make these batteries a viable alternative to existing systems. PMID:11048714

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

2000-10-12

127

Study on immunosensor based on gold nanoparticles\\/chitosan and MnO 2 nanoparticles composite membrane\\/Prussian blue modified gold electrode  

Microsoft Academic Search

A novel and convenient immunosensor, based on the electrostatic adsorption characteristics between the positively charged\\u000a MnO2 nanoparticles (nano-MnO2) and chitosan (CS) composite membrane (nano-MnO2+CS) and the negatively charged prussian blue (PB), was prepared for the detection of carcinoembryonic antigen (CEA). Firstly,\\u000a PB was electro-deposited on the surface of the gold electrode in the constant potential, and then nano-MnO2+CS was adsorbed

Shujuan Ling; Ruo Yuan; Yaqin Chai; Tingting Zhang

2009-01-01

128

Removal of NO2 and O3 generated from corona discharge in indoor air cleaning with MnO2 catalyst  

NASA Astrophysics Data System (ADS)

The production rules and removal efficiency of harmful byproducts such as NO2 and O3 generated from DC corona discharge in indoor air cleaning were investigated. The production behaviours of NO2 and O3 and the relationship between the amount of catalyst (MnO2) and the removal rate of harmful byproducts were experimentally studied. Further, indoor application tests were carried out in a closed room with 90 m3. The results showed that the concentrations of NO2 and O3 produced by corona discharge linearly increased with discharge time. The NO2 yield is larger than O3 by almost one order of magnitude under the same discharge power. To satisfy the demand of Standard of Indoor Air Quality (GB/T18883-2002), the power consumption of unit volume should be less than 1 W m-3 and the catalyst MnO2 consumptions in positive-negative corona discharge were 200 cm3 W-1 and 100 cm3 W-1, respectively.

Ge, H.; Yu, R.; Mi, D.; Zhu, Y. M.

2013-03-01

129

Facile synthesis of hierarchically structured magnetic MnO2/ZnFe2O4 hybrid materials and their performance in heterogeneous activation of peroxymonosulfate.  

PubMed

In heterogeneous catalysis for water treatment, feasible recovery of nanocatalysts is crucial to make the process cost-effective and environmentally benign. In this study, we applied two strategies, for example, magnetic separation and hierarchical structure of solid catalysts, to ensure manganese catalysts are readily separable, meanwhile their catalytic performance was retained by the nanosized structure of MnO2 nanosheets or nanorods. ZnFe2O4 was used as the magnetic core and MnO2 corolla-like sphere consisting of nanosheets, and sea-urchin shaped structure made of nanorods, were fabricated by a hydrothermal method at 100 and 140 C, respectively. Crystalline structure, morphology and textural property of the materials were investigated. The prepared catalysts were able to effectively activate peroxymonosulfate (PMS) to generate sulfate radicals for catalytic oxidation of a typical organic pollutant of phenol. After the heterogeneous catalysis, the catalysts were easily recovered by applying an external magnetic field. The effects of temperature and repeated use on the degradation efficiencies were evaluated. The generation and evolution of sulfate radicals and phenol oxidation were studied using both competitive radical tests and electron paramagnetic resonance (EPR). PMID:25350938

Wang, Yuxian; Sun, Hongqi; Ang, Ha Ming; Tad, Moses O; Wang, Shaobin

2014-11-26

130

The Effect of Porosity on Heat Transfer and Mass Transfer of Mg-3Ni-2MnO2 Hydrogen Storage Materials Reaction Bed  

NASA Astrophysics Data System (ADS)

Hydrided Mg-3Ni-2MnO2 composite powders were prepared by mechanical milling under hydrogen atmosphere. Heat and mass transfer, the effective thermal conductivity (ETC) of the hydrided Mg-3Ni-2MnO2 powder reaction bed with various porosities were measured using a self-made apparatus. The effect of porosity on the bed is also analysized. The results show that the ETC of reaction bed is poor and it increases with decreasing porosity. Three porosities, 0.37, 0.53, 0.63 were selected in the present work. The bed with 0.53 porosity exhibits relatively fast reaction rates in both hydrogenation and dehydrogenation process. The hydrogenation process is a fast exothermic reaction resulting in a quick increase if the temperature of the bed during this process, and there is a temperature gradient: the temperature close to the bed wall is lower but higher at the center of bed. In dehydrogenation of the bed, the temperature of hydrided bed decreases due to the endothermic reaction, and the temperature at the center falls the lowest and keep at that temperature for a long time. The analyses reveal that increase of ETC don't always helps to improve the bed's hydriding and dehydriding rates. There should be an optimal porosity which helps to transfer both the heat and the mass.

Zhang, Wencong; Wang, Gang; Ma, Junfei; Wang, Zhaoyou; Wang, Erde

131

Frustrated exchange interactions formation at low temperatures and high hydrostatic pressures in La0.70Sr0.30MnO2.85  

NASA Astrophysics Data System (ADS)

The magnetic and thermal properties of the anion-deficient La0.70Sr0.30MnO2.85 manganite are investigated in wide temperature (4-350 K) range, including under hydrostatic pressure (0-1.1 GPa). Throughout the pressure range investigated, the sample is spin glass with diffused phase transition into paramagnetic state. It is established, that spin glass state is a consequence of exchange interaction frustration of the ferromagnetic clusters embeded into antiferromagnetic clusters. The magnetic moment freezing temperature T f of ferromagnetic clusters increases under pressure, freezing temperature dependence on pressure is characterized by derivative value 4.5 K/GPa, while the magnetic ordering T MO temperature dependence is characterized by derivative value 13 K/GPa. The volume fraction of sample having ferromagnetic state is V fer 13% and it increases under a pressure of 1.1 GPa by ? V fer ? 6%. Intensification of ferromagnetic properties of the anion-deficient La0.70Sr0.30MnO2.85 manganite under hydrostatic pressure is a consequence of oxygen vacancies redistribution and unit cell parameters decrease. The most likely mechanism of frustrated exchange interactions formation is discussed.

Trukhanov, S. V.; Trukhanov, A. V.; Vasiliev, A. N.; Szymczak, H.

2010-08-01

132

Chemically rechargeable battery  

NASA Technical Reports Server (NTRS)

Batteries (50) containing oxidized, discharged metal electrodes such as an iron-air battery are charged by removing and storing electrolyte in a reservoir (98), pumping fluid reductant such as formalin (aqueous formaldehyde) from a storage tank (106) into the battery in contact with the surfaces of the electrodes. After sufficient iron hydroxide has been reduced to iron, the spent reductant is drained, the electrodes rinsed with water from rinse tank (102) and then the electrolyte in the reservoir (106) is returned to the battery. The battery can be slowly electrically charged when in overnight storage but can be quickly charged in about 10 minutes by the chemical procedure of the invention.

Graf, James E. (Inventor); Rowlette, John J. (Inventor)

1984-01-01

133

Functional materials for rechargeable batteries.  

PubMed

There is an ever-growing demand for rechargeable batteries with reversible and efficient electrochemical energy storage and conversion. Rechargeable batteries cover applications in many fields, which include portable electronic consumer devices, electric vehicles, and large-scale electricity storage in smart or intelligent grids. The performance of rechargeable batteries depends essentially on the thermodynamics and kinetics of the electrochemical reactions involved in the components (i.e., the anode, cathode, electrolyte, and separator) of the cells. During the past decade, extensive efforts have been dedicated to developing advanced batteries with large capacity, high energy and power density, high safety, long cycle life, fast response, and low cost. Here, recent progress in functional materials applied in the currently prevailing rechargeable lithium-ion, nickel-metal hydride, lead acid, vanadium redox flow, and sodium-sulfur batteries is reviewed. The focus is on research activities toward the ionic, atomic, or molecular diffusion and transport; electron transfer; surface/interface structure optimization; the regulation of the electrochemical reactions; and the key materials and devices for rechargeable batteries. PMID:21394791

Cheng, Fangyi; Liang, Jing; Tao, Zhanliang; Chen, Jun

2011-04-19

134

Chemical bath deposition synthesis and electrochemical properties of MnO2 thin film: Effect of deposition time and bath temperature  

NASA Astrophysics Data System (ADS)

Manganese dioxide (MnO2) films with different nanostructures were deposited on indium tin oxide (ITO) glasses by using chemical bath deposition (CBD). Deposition temperature and time were varied from 60 C to 90 C and from 2 h to 72 h, respectively. The samples have been characterized using an X-ray diffraction (XRD), field emission scanning electron microscope (SEM) and an electrochemical workstation. The films deposited at 60 C for 8 h showed that obtained nanoflowers had an amorphous nature, while those deposited at higher temperatures of 70, 80 and 90 C showed a well-developed nanowire and nanorod morphology. However, those which were deposited at 60 C, showed the best electrochemical properties, including a higher specific capacitance, good rate of performance and a cycling stability (93 % loss of the initial value after 10,000 cycles).

Aref, A. A.; Tang, Y. W.

2014-12-01

135

Expressing user profiles for data recharging  

Microsoft Academic Search

Mobile devices need two basic renewable resources - power and data. Power recharging is easy; data recharging is a much more problematic activity. It requires complex interaction between a user and a collection of data sources. We provide an automatic data recharging capability based on user profiles written in an expressive profile language. A profile identifies relevant information and orders

Mitch Cherniack; Michael J. Franklin; Stan Zdonik

2001-01-01

136

Reusable Energy and Power Sources: Rechargeable Batteries  

ERIC Educational Resources Information Center

Rechargeable batteries are very popular within consumer electronics. If one uses a cell phone or portable electric tool, she/he understands the need to have a reliable product and the need to remember to use the recharging systems that follow a cycle of charge/discharge. Rechargeable batteries are being called "green" energy sources. They are a

Hsiung, Steve C.; Ritz, John M.

2007-01-01

137

Reaction of lincosamide antibiotics with manganese oxide in aqueous solution.  

PubMed

Lincosamides are among the most frequently detected antibacterial agents in effluents from wastewater treatment plants and surface runoff at agricultural production systems. Little is known about their transformations in the environment. This study revealed that manganese oxide caused rapid and extensive decomposition of clindamycin and lincomycin in aqueous solution. The reactions occurred mainly at the pyranose ring of lincosamides, initially by formation of complexes with Mn and cleavage of the ether linkage, leading to the formation of a variety of degradation products via subsequent hydrolytic and oxidative reactions. The results of LC-MS/MS and FTIR analysis confirm cleavage of the C-O-C bond in the pyranose ring, formation of multiple carbonyl groups, and transformation of the methylthio moiety to sulfur oxide. The overall transformation was controlled by interactions of cationic species of lincosamides with MnO(2) surfaces. The presence of electrolytes (i.e., NaCl, CaCl(2), and MnCl(2)) and dissolved organic matter in aqueous solution, and increase of solution pH, diminished lincosamide binding to MnO(2) hence reducing the rate and magnitude of the transformations. Results from this study indicate that manganese dioxides in soils and sediments could contribute to the decomposition of lincosamide antibiotics released into the environment. PMID:20476766

Chen, Wan-Ru; Ding, Yunjie; Johnston, Cliff T; Teppen, Brian J; Boyd, Stephen A; Li, Hui

2010-06-15

138

Rechargeable nickel-zinc batteries  

NASA Technical Reports Server (NTRS)

Device proves superiority in having two and one half to three times the energy content of popular lead-zinc or nickel-cadmium batteries. Application to electric utility vehicles improved acceleration rate and nearly doubled driving range between rechargings. Unit contributes substantially toward realization of practical urban electrical automobiles.

Soltis, D. G.

1977-01-01

139

Aquifer Management with Logistic Recharge  

Microsoft Academic Search

Theoretical principles of sustainable aquifer management are laid out in this work. The premise of our treatment is that groundwater is a renewable, although exhaustible, natural resource. The theory of this work is aimed at aquifers with a relatively homogeneous recharge that can be approximated by a logistic growth function. Sustainable aquifer exploitation occurs when the rate of ground-water extraction

Hugo A. Laiciga; Roy B. Leipnik

2001-01-01

140

Revised 06-2011 Rechargeable  

E-print Network

Nickel ­ Cadmium Nickel Metal Hydride Li-ion Pb Acid NiCd NiMH Used mainly in consumer electronics UsedRevised 06-2011 Rechargeable Battery And Cell Phone Recycling Program Guidelines University Waste Label (see separate instructions). Step 4: Bag It Insert a battery or cell phone in a provided bag

Taylor, Jerry

141

The pronounced seasonality of global groundwater recharge  

NASA Astrophysics Data System (ADS)

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.

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

2014-11-01

142

Organized and highly dispersed growth of MnO2 nano-rods by sonochemical hydrolysis of Mn3acetate.  

PubMed

Highly dispersed and non-agglomerated alpha-MnO(2) nano-needles of dimensions 20-30 nm have been synthesized by the application of ultrasound radiation on the aqueous solution consisting of manganese(3)acetate close to neutral pH followed by mild drying. With a similar reaction system, hot hydrolysis (non-sonochemical process) produced beta-MnO(2) nano-rods of length 100-200 nm but with high degree agglomeration. Sonochemical cavitation phenomenon is suggested to have a pronounced effect for the formation of special phase and morphology. The effect is proved by the difference in the intermediate products which has difference in crystalinity and phase-purity. The intermediate phases are identified to be single-phase gamma-MnOOH for the non-sonochemical reaction and mixture of gamma-MnOOH, alpha-MnO(2) and beta-MnO(2) for the sonochemical products. PMID:16359902

Kumar, V Ganesh; Kim, Kwang Bum

2006-09-01

143

Electrically rechargeable REDOX flow cell  

NASA Technical Reports Server (NTRS)

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.

Thaller, L. H. (inventor)

1976-01-01

144

Research on rechargeable oxygen electrodes  

NASA Technical Reports Server (NTRS)

Studies were carried out on a number of factors which may influence the behavior of the platinum electrocatalyst of oxygen electrodes for use in rechargeable metal-oxygen batteries or hydrogen-oxygen fuel cells. The effects of pretreatments for various potentials and added ionic species, which could be present in such systems, were studied with reguard to: (1) the state of surface oxidation, (2) platinum dissolution, (3) the kinetics of oxygen evolution and reduction (including the role of hydrogen peroxide), and (4) changes in porous electrode structure. These studies were carried out on smooth platinum, platinized platinum, and Teflon-bonded platinum black electrodes in carefully purified electrolyte solutions. The main factors which appear to affect rechargeable oxygen electrode performance and life are: (1) the buildup of a refractory anodic layer on extended cycling, and (2) the dissolution of platinum.

Giner, J.; Malachesky, P. A.; Holleck, G.

1971-01-01

145

Nanomaterials for rechargeable lithium batteries.  

PubMed

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

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

2008-01-01

146

Rechargeable solid state lithium microbatteries  

Microsoft Academic Search

A rechargeable thin-film lithium battery that can be used as a miniature power supply for small devices has been developed. The battery consists of an amorphous vanadium pentoxide (aV2O5) cathode, an amorphous lithium phosphorus oxynitride (Lipon) electrolyte, and a lithium anode. A thin-film cover layer protects the battery from exposure to air and water vapor. The battery can deliver up

J. B. Bates; G. R. Gruzalski; C. F. Luck

1993-01-01

147

Groundwater recharge and agricultural contamination  

USGS Publications Warehouse

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.

Bhlke, J.K.

2002-01-01

148

Choosing appropriate techniques for quantifying groundwater recharge  

Microsoft Academic Search

. Various techniques are available to quantify recharge; however, choosing appropriate techniques is often difficult. Important\\u000a considerations in choosing a technique include space\\/time scales, range, and reliability of recharge estimates based on different\\u000a techniques; other factors may limit the application of particular techniques. The goal of the recharge study is important\\u000a because it may dictate the required space\\/time scales of

Bridget R. Scanlon; Richard W. Healy; Peter G. Cook

2002-01-01

149

Rechargeable lithium battery technology - A survey  

NASA Technical Reports Server (NTRS)

The technology of the rechargeable lithium battery is discussed with special attention given to the types of rechargeable lithium cells and to their expected performance and advantages. Consideration is also given to the organic-electrolyte and polymeric-electrolyte cells and to molten salt lithium cells, as well as to technical issues, such as the cycle life, charge control, rate capability, cell size, and safety. The role of the rechargeable lithium cell in future NASA applications is discussed.

Halpert, Gerald; Surampudi, Subbarao

1990-01-01

150

Identifying and quantifying urban recharge: a review  

Microsoft Academic Search

. The sources of and pathways for groundwater recharge in urban areas are more numerous and complex than in rural environments.\\u000a Buildings, roads, and other surface infrastructure combine with man-made drainage networks to change the pathways for precipitation.\\u000a Some direct recharge is lost, but additional recharge can occur from storm drainage systems. Large amounts of water are imported\\u000a into most

David N. Lerner

2002-01-01

151

A possible evolutionary origin for the Mn4 cluster of the photosynthetic water oxidation complex from natural MnO2 precipitates in the early ocean  

PubMed Central

The photosynthetic water oxidation complex consists of a cluster of four Mn atoms bridged by O atoms, associated with Ca2+ and Cl?, and incorporated into protein. The structure is similar in higher plants and algae, as well as in cyanobacteria of more ancient lineage, dating back more than 2.5 billion years ago on Earth. It has been proposed that the proto-enzyme derived from a component of a natural early marine manganese precipitate that contained a CaMn4O9 cluster. A variety of MnO2 minerals are found in nature. Three major classes are spinels, sheet-like layered structures, and three-dimensional networks that contain parallel tunnels. These relatively open structures readily incorporate cations (Na+, Li+, Mg2+, Ca2+, Ba2+, H+, and even Mn2+) and water. The minerals have different ratios of Mn(III) and Mn(IV) octahedrally coordinated to oxygens. Using x-ray spectroscopy we compare the chemical structures of Mn in the minerals with what is known about the arrangement in the water oxidation complex to define the parameters of a structural model for the photosynthetic catalytic site. This comparison provides for the structural model a set of candidate Mn4 clusterssome previously proposed and considered and others entirely novel. PMID:12077302

Sauer, Kenneth; Yachandra, Vittal K.

2002-01-01

152

A possible evolutionary origin for the Mn4 cluster of the photosynthetic water oxidation complex from natural MnO2 precipitates in the early ocean  

SciTech Connect

The photosynthetic water oxidation complex consists of a cluster of 4 Mn atoms bridged by O atoms, associated with Ca2+ and Cl- and incorporated into protein. The structure is similar in higher plants and algae, as well as in cyanobacteria of more ancient lineage, dating back more than 2.5 Ga on Earth. It has been proposed that the proto-enzyme derived from a component of a natural early marine manganese precipitate that contained a CaMn4O9 cluster. A variety of MnO2 minerals is found in nature. Three major classes are spinels, sheet-like layered structures and 3-dimensional networks that contain parallel tunnels. These relatively open structures readily incorporate cations (Na+, Li+, Mg2+, Ca2+, Ba2+, H+ and even Mn2+) and water. The minerals have different ratios of Mn(III) and Mn(IV) octahedrally coordinated to oxygens. Using X-ray spectroscopy we compare the chemical structures of Mn in the minerals with what is known about the arrangement in the water-oxidation complex to define the parameters of a structural model for the photosynthetic catalytic site. This comparison provides for the structural model a set of candidate Mn4 clusters -- some previously proposed and considered and others entirely novel.

Sauer, Kenneth; Yachandra, Vittal K.

2002-04-30

153

Direct visualization of the Jahn-Teller effect coupled to Na ordering in Na5/8MnO2.  

PubMed

The cooperative Jahn-Teller effect (CJTE) refers to the correlation of distortions arising from individual Jahn-Teller centres in complex compounds. The effect usually induces strong coupling between the static or dynamic charge, orbital and magnetic ordering, which has been related to many important phenomena such as colossal magnetoresistance and superconductivity. Here we report a Na5/8MnO2 superstructure with a pronounced static CJTE that is coupled to an unusual Na vacancy ordering. We visualize this coupled distortion and Na ordering down to the atomic scale. The Mn planes are periodically distorted by a charge modulation on the Mn stripes, which in turn drives an unusually large displacement of some Na ions through long-ranged Na-O-Mn(3+)-O-Na interactions into a highly distorted octahedral site. At lower temperatures, magnetic order appears, in which Mn atomic stripes with different magnetic couplings are interwoven with each other. Our work demonstrates the strong interaction between alkali ordering, displacement, and electronic and magnetic structure, and underlines the important role that structural details play in determining electronic behaviour. PMID:24836735

Li, Xin; Ma, Xiaohua; Su, Dong; Liu, Lei; Chisnell, Robin; Ong, Shyue Ping; Chen, Hailong; Toumar, Alexandra; Idrobo, Juan-Carlos; Lei, Yuechuan; Bai, Jianming; Wang, Feng; Lynn, Jeffrey W; Lee, Young S; Ceder, Gerbrand

2014-06-01

154

Fabrication of Polypyrrole/Graphene Oxide Composite Nanosheets and Their Applications for Cr(VI) Removal in Aqueous Solution  

PubMed Central

In this paper, we report on the simple, reliable synthesis of polypyrrole (PPy)/graphene oxide (GO) composite nanosheets by using sacrificial-template polymerization method. Herein, MnO2 nanoslices were chosen as a sacrificial-template to deposit PPy, which served as the oxidant as well. During the polymerization of pyrrole on surface of GO nanosheets, MnO2 component was consumed incessantly. As a result, the PPy growing on the surface of GO nanosheets has the morphology just like the MnO2 nanoslices. This method can provide the fabrication of PPy nanostructures more easily than conventional route due to its independence of removing template, which usually is a complex and tedious experimental process. The as-prepared PPy/GO composite nanosheets exhibited an enhanced properties for Cr(VI) ions removal in aqueous solution based on the synergy effect. The adsorption capacity of the PPy/GO composite nanosheets is about two times as large as that of conventional PPy nanoparticles. We believe that our findings can open a new and effective avenue to improve the adsorption performance in removing heavy metal ions from waste water. PMID:22927957

Li, Shangkun; Lu, Xiaofeng; Xue, Yanpeng; Lei, Junyu; Zheng, Tian; Wang, Ce

2012-01-01

155

NORTH CAROLINA GROUNDWATER RECHARGE RATES 1994  

EPA Science Inventory

North Carolina Groundwater Recharge Rates, from Heath, R.C., 1994, Ground-water recharge in North Carolina: North Carolina State University, as prepared for the NC Department of Environment, Health and Natural Resources (NC DEHNR) Division of Enviromental Management Groundwater S...

156

Maximizing Charging Throughput in Rechargeable Sensor Networks  

E-print Network

Maximizing Charging Throughput in Rechargeable Sensor Networks Xiaojiang Ren Weifa Liang Wenzheng reliable energy supplies for sensors in wireless rechargeable sensor net- works. The adoption of wireless. The lifetime of traditional battery-powered sensor networks is limited by the capacities of batteries. Even

Liang, Weifa

157

Transformer Recharging with Alpha Channeling in Tokamaks  

SciTech Connect

Transformer recharging with lower hybrid waves in tokamaks can give low average auxiliary power if the resistivity is kept high enough during the radio frequency (rf) recharging stage. At the same time, operation in the hot ion mode via alpha channeling increases the effective fusion reactivity. This paper will address the extent to which these two large cost saving steps are compatible. __________________________________________________

N.J. Fisch

2009-12-21

158

Recharge at the Hanford Site: Status report  

SciTech Connect

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.

Gee, G.W.

1987-11-01

159

Identifying and quantifying urban recharge: a review  

NASA Astrophysics Data System (ADS)

The sources of and pathways for groundwater recharge in urban areas are more numerous and complex than in rural environments. Buildings, roads, and other surface infrastructure combine with man-made drainage networks to change the pathways for precipitation. Some direct recharge is lost, but additional recharge can occur from storm drainage systems. Large amounts of water are imported into most cities for supply, distributed through underground pipes, and collected again in sewers or septic tanks. The leaks from these pipe networks often provide substantial recharge. Sources of recharge in urban areas are identified through piezometry, chemical signatures, and water balances. All three approaches have problems. Recharge is quantified either by individual components (direct recharge, water-mains leakage, septic tanks, etc.) or holistically. Working with individual components requires large amounts of data, much of which is uncertain and is likely to lead to large uncertainties in the final result. Recommended holistic approaches include the use of groundwater modelling and solute balances, where various types of data are integrated. Urban recharge remains an under-researched topic, with few high-quality case studies reported in the literature.

Lerner, David N.

2002-02-01

160

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...

161

Rechargeable lithium-ion cell  

DOEpatents

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).

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

1999-01-01

162

Rechargeable lead-acid batteries.  

PubMed

Batteries used in medical equipment, like their counterparts in consumer products, attract little attention until they fail to function effectively. In some applications, such as in emergency medical devices, battery failure can have fatal consequences. While modern batteries are usually quite reliable, ECRI has received 53 written problem reports and countless verbal reports or questions related to battery problems in hospitals during the past five years. This large number of reports is due, at least in part, to the enormous quality of batteries used to operate or provide backup power in contemporary hospital equipment. As part of an ongoing evaluation of rehabilitation assistive equipment, ECRI has been studying the performance of 12 V rechargeable deep-cycle lead-acid batteries used in powered wheelchairs. During the course of this evaluation, it has become apparent that many professionals, both clinical and industrial, regard batteries as "black box" devices and know little about proper care and maintenance--and even less about battery selection and purchase. Because equipment performance and reliability can be strongly influenced by different battery models, an understanding of battery characteristics and how they affect performance is essential when selecting and purchasing batteries. The types of rechargeable batteries used most commonly in hospitals are lead-acid and nickel-cadmium (nicad), which we compare below; however, the guidance we provide in this article focuses on lead-acid batteries. While the examples given are for high-capacity 12 V deep-cycle batteries, similar analyses can be applied to smaller lead-acid batteries of different voltages. PMID:2211174

1990-09-01

163

Regional Estimation of Total Recharge to Ground Water in Nebraska  

E-print Network

Regional Estimation of Total Recharge to Ground Water in Nebraska by Jozsef Szilagyi1m2,F. Edwin Harvey', and Jerry F. Ayers' Abstract Naturally occurring long-term mean annual recharge to ground water (GIS) layers of land cover, elevation of land and ground water surfaces,base recharge, and the recharge

Szilagyi, Jozsef

164

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

Microsoft Academic Search

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

Marios Sophocleous

1992-01-01

165

REVISED NORTH CAROLINA GROUNDWATER RECHARGE RATES 1998  

EPA Science Inventory

Revised North Carolina Groundwater Recharge Rates, from Heath, R.C., 1994, unpublished map: North Carolina State University, as modified by the NC Department of Environment and Natural Resources (DENR) Division of Water Quality (DWQ) Groundwater Section, (polygons)...

166

Groundwater Recharge Simulator M. Tech. Thesis  

E-print Network

Groundwater Recharge Simulator M. Tech. Thesis by Dharmvir Kumar Roll No: 07305902 Guide: Prof;Contents 1 Introduction 1 1.1 Groundwater Theory.1.5 Groundwater Flow Equation . . . . . . . . . . . . . . . . . . . . . . 11 1.2 Numerical Solvers and Boundary

Sohoni, Milind

167

Design of an AUV recharging system  

E-print Network

The utility of present Autonomous Underwater Vehicles (AUVs) is limited by their on-board energy storage capability. Research indicates that rechargeable batteries will continue to be the AUV power source of choice for at ...

Gish, Lynn Andrew

2004-01-01

168

Teeny tiny windmills could recharge phones Share it now!  

E-print Network

Teeny tiny windmills could recharge phones Green Tech Share it now! 0 One of the tiny windmills recharge phones | VantageWire 2/1/2014http://www.vantagewire.com/2014/01/teeny-tiny-windmills-could-recharge-phones could recharge phones | VantageWire 2/1/2014http://www.vantagewire.com/2014/01/teeny-tiny-windmills-could-recharge-phones

Chiao, Jung-Chih

169

Anodes for rechargeable lithium batteries  

DOEpatents

A negative electrode (12) for a non-aqueous electrochemical cell (10) with an intermetallic host structure containing two or more elements selected from the metal elements and silicon, capable of accommodating lithium within its crystallographic host structure such that when the host structure is lithiated it transforms to a lithiated zinc-blende-type structure. Both active elements (alloying with lithium) and inactive elements (non-alloying with lithium) are disclosed. Electrochemical cells and batteries as well as methods of making the negative electrode are disclosed.

Thackeray, Michael M. (Naperville, IL); Kepler, Keith D. (Mountain View, CA); Vaughey, John T. (Elmhurst, IL)

2003-01-01

170

Modeling Recharge - can it be Done?  

NASA Astrophysics Data System (ADS)

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?

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

2001-12-01

171

A bi-functional device for self-powered electrochromic window and self-rechargeable transparent battery applications.  

PubMed

Electrochromic smart windows are regarded as a good choice for green buildings. However, conventional devices need external biases to operate, which causes additional energy consumption. Here we report a self-powered electrochromic window, which can be used as a self-rechargeable battery. We use aluminium to reduce Prussian blue (PB, blue in colour) to Prussian white (PW, colourless) in potassium chloride electrolyte, realizing a device capable of self-bleaching. Interestingly, the device can be self-recovered (gaining blue appearance again) by simply disconnecting the aluminium and PB electrodes, which is due to the spontaneous oxidation of PW to PB by the dissolved oxygen in aqueous solution. The self-operated bleaching and colouration suggest another important function of the device: a self-rechargeable transparent battery. Thus the PB/aluminium device we report here is bifunctional, that is, it is a self-powered electrochromic window as well as a self-rechargeable transparent battery. PMID:25247385

Wang, Jinmin; Zhang, Lei; Yu, Le; Jiao, Zhihui; Xie, Huaqing; Lou, Xiong Wen David; Sun, Xiao Wei

2014-01-01

172

A bi-functional device for self-powered electrochromic window and self-rechargeable transparent battery applications  

NASA Astrophysics Data System (ADS)

Electrochromic smart windows are regarded as a good choice for green buildings. However, conventional devices need external biases to operate, which causes additional energy consumption. Here we report a self-powered electrochromic window, which can be used as a self-rechargeable battery. We use aluminium to reduce Prussian blue (PB, blue in colour) to Prussian white (PW, colourless) in potassium chloride electrolyte, realizing a device capable of self-bleaching. Interestingly, the device can be self-recovered (gaining blue appearance again) by simply disconnecting the aluminium and PB electrodes, which is due to the spontaneous oxidation of PW to PB by the dissolved oxygen in aqueous solution. The self-operated bleaching and colouration suggest another important function of the device: a self-rechargeable transparent battery. Thus the PB/aluminium device we report here is bifunctional, that is, it is a self-powered electrochromic window as well as a self-rechargeable transparent battery.

Wang, Jinmin; Zhang, Lei; Yu, Le; Jiao, Zhihui; Xie, Huaqing; Lou, Xiong Wen (David); Wei Sun, Xiao

2014-09-01

173

Using groundwater levels to estimate recharge  

USGS Publications Warehouse

Accurate estimation of groundwater recharge is extremely important for proper management of groundwater systems. Many different approaches exist for estimating recharge. This paper presents a review of methods that are based on groundwater-level data. The water-table fluctuation method may be the most widely used technique for estimating recharge; it requires knowledge of specific yield and changes in water levels over time. Advantages of this approach include its simplicity and an insensitivity to the mechanism by which water moves through the unsaturated zone. Uncertainty in estimates generated by this method relate to the limited accuracy with which specific yield can be determined and to the extent to which assumptions inherent in the method are valid. Other methods that use water levels (mostly based on the Darcy equation) are also described. The theory underlying the methods is explained. Examples from the literature are used to illustrate applications of the different methods.

Healy, R.W.; Cook, P.G.

2002-01-01

174

Experimental studies in natural groundwater-recharge dynamics: The analysis of observed recharge events  

NASA Astrophysics Data System (ADS)

The amounts and time distribution of groundwater recharge from precipitation over an approximately 19-month period were investigated at two instrumented sites in south-central Kansas. Precipitation and evapotranspiration sequences, soil-moisture profiles and storage changes, water fluxes in the unsaturated zone and hydraulic gradients in the saturated zone at various depths, soil temperatures, water-table hydrographs, and water-level changes in nearby wells clearly depict the recharge process. Antecedent moisture conditions and the thickness and nature of the unsaturated zone were found to be the major factors affecting recharge. Although the two instrumented sites are located in sand-dune environments in areas characterized by shallow water table and subhumid continental climate, a significant difference was observed in the estimated effective recharge. The estimates ranged from less than 2.5 to approximately 154 mm at the two sites from February to June 1983. The main reasons for this large difference in recharge estimates were the greater thickness of the unsaturated zone and the lower moisture content in that zone resulting from lower precipitation and higher potential evapotranspiration for one of the sites. Effective recharge took place only during late winter and spring. No summer or fall recharge was observed at either site during the observation period of this study.

Sophocleous, Marios; Perry, Charles A.

1985-11-01

175

Impacts of vegetation change on groundwater recharge  

NASA Astrophysics Data System (ADS)

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.

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

2003-12-01

176

Solar recharging system for hearing aid cells.  

PubMed

We present a solar recharging system for nickel-cadmium cells of interest in areas where batteries for hearing aids are difficult to obtain. The charger has sun cells at the top. Luminous energy is converted into electrical energy, during the day and also at night if there is moonlight. The cost of the charger and hearing aid is very low at 35 US$. The use of solar recharging for hearing aids would be useful in alleviating the problems of deafness in parts of developing countries where there is no electricity. PMID:7964140

Gmez Estancona, N; Tena, A G; Torca, J; Urruticoechea, L; Muiz, L; Aristimuo, D; Unanue, J M; Torca, J; Urruticoechea, A

1994-09-01

177

REFLEAK: NIST Leak/Recharge Simulation Program for Refrigerant Mixtures  

National Institute of Standards and Technology Data Gateway

SRD 73 NIST REFLEAK: NIST Leak/Recharge Simulation Program for Refrigerant Mixtures (PC database for purchase) REFLEAK estimates composition changes of zeotropic mixtures in leak and recharge processes.

178

Micro Windmills to Recharge Cell Leave a reply  

E-print Network

Micro Windmills to Recharge Cell Phones Leave a reply The Windmill in Action At the University of Texas Arlington, scientists J.C. Chiao and Smitha Rao have developed micro-windmills which recharge Page 1 of 2Micro Windmills to Recharge Cell Phones | MADE 2/3/2014http://themadeblog.com/micro

Chiao, Jung-Chih

179

Microstructural Modeling and Design of Rechargeable Lithium-Ion Batteries  

E-print Network

Microstructural Modeling and Design of Rechargeable Lithium-Ion Batteries R. Edwin Garci´a,a, *,z information and constitutive material properties to calculate the response of rechargeable batteries of a recharge- able battery provides valuable insight into optimizing the perfor- mance of the device

García, R. Edwin

180

Melt-Formable Block Copolymer Electrolytes for Lithium Rechargeable Batteries  

E-print Network

Melt-Formable Block Copolymer Electrolytes for Lithium Rechargeable Batteries Anne-Vale´rie G conductivity in polymer electrolytes for solid-state rechargeable lithium batteries. However, due to the strong in solid-state rechargeable lithium batteries. Yet, technical obstacles to their commercialization derive

Sadoway, Donald Robert

181

Block Copolymer-Templated Nanocomposite Electrodes for Rechargeable Lithium Batteries  

E-print Network

Block Copolymer-Templated Nanocomposite Electrodes for Rechargeable Lithium Batteries S. C. Mui-organizing, nanocomposite electrode SONE system was developed as a model lithium alloy-based anode for rechargeable lithium of rechargeable lithium batteries, the search for high capacity anodes that avoid the safety concerns associated

Sadoway, Donald Robert

182

Sources of uncertainty in climate change impacts on groundwater recharge  

Microsoft Academic Search

This paper assesses the significance of the many sources of uncertainty in future groundwater recharge estimation, based on lessons learnt from an integrated approach to assessing the regional impacts of climate and socio-economic change on groundwater recharge in East Anglia, UK. Many factors affect simulations of future groundwater recharge including changed precipitation and temperature regimes, coastal flooding, urbanization, woodland establishment,

I. P. Holman

2007-01-01

183

Composite Electrolytes for Lithium Rechargeable Batteries  

Microsoft Academic Search

The paper reviews and presents attributes of emerging polymer-ceramic composite electrolytes for lithium rechargeable batteries. The electrochemical data of a diverse range of composite electrolytes reveal that the incorporation of a ceramic component in a polymer matrix leads to enhanced conductivity, increased lithium transport number, and improved electrode-electrolyte interfacial stability. The conductivity enhancement depends upon the weight fraction of the

Binod Kumar; Lawrence G. Scanlon

2000-01-01

184

Recharging Our Sense of Idealism: Concluding Thoughts  

ERIC Educational Resources Information Center

In this article, the authors aim to recharge one's sense of idealism. They argue that idealism is the Vitamin C that sustains one's commitment to implementing humanistic principles and social justice practices in the work of counselors and educators. The idealism that characterizes counselors and educators who are humanistic and social justice

D'Andrea, Michael; Dollarhide, Colette T.

2011-01-01

185

Tradable recharge rights in Coleambally Irrigation Area  

Microsoft Academic Search

Irrigated agriculture in Australia often leads to recharge of shared groundwater systems causing saline shallow watertables and soil salinity. In turn, these biophysical impacts impose costs, including reduced agricultural productivity, damage to ecosystems and degradation of local and off-site infrastructure, on irrigators and other members of the community. To the extent these costs are external to landowners they are not

Stuart Whitten; Shahbaz Khan

186

Anode for rechargeable ambient temperature lithium cells  

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

187

Design considerations for rechargeable lithium batteries  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

188

Rechargeable solid polymer electrolyte battery cell  

DOEpatents

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.

Skotheim, Terji (East Patchoque, NY)

1985-01-01

189

Alloys of clathrate allotropes for rechargeable batteries  

DOEpatents

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.

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

2014-12-09

190

An acid-free rechargeable battery based on PbSO4 and spinel LiMn2O4.  

PubMed

An acid-free lead rechargeable battery system comprising PbSO4 as the negative electrode, LiMn2O4 as the positive electrode and a neutral Li2SO4 aqueous solution as electrolyte is reported and its electrochemical performance is very good. It shows great promise to reduce the global use of lead by 50% since it is also low cost. PMID:25248439

Liu, Yu; Wen, Zubiao; Wu, Xiongwei; Wang, Xiaowei; Wu, Yuping; Holze, Rudolf

2014-11-18

191

Automatic rainfall recharge model induction by evolutionary computational intelligence  

NASA Astrophysics Data System (ADS)

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.

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

2005-08-01

192

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

NASA Astrophysics Data System (ADS)

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.

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

2005-12-01

193

A new rechargeable intelligent vehicle detection sensor  

NASA Astrophysics Data System (ADS)

Intelligent Transportation System (ITS) is a valid approach to solve the increasing transportation issue in cities. Vehicle detection is one of the key technologies in ITS. The ITS collects and processes traffic data (vehicle flow, vehicular speed, vehicle density and occupancy ratios) from vehicle detection sensors buried under the road or installed along the road. Inductive loop detector as one type of the vehicle detector is applied extensively, with the characters of stability, high value to cost ratio and feasibility. On the other hand, most of the existing inductive loop vehicle detection sensors have some weak points such as friability of detective loop, huge engineering for setting and traffic interruption during installing the sensor. The design and reality of a new rechargeable intelligent vehicle detection sensor is presented in this paper against these weak points existing now. The sensor consists of the inductive loop detector, the rechargeable batteries, the MCU (microcontroller) and the transmitter. In order to reduce the installing project amount, make the loop durable and easily maintained, the volume of the detective loop is reduced as much as we can. Communication in RF (radio frequency) brings on the advantages of getting rid of the feeder cable completely and reducing the installing project amount enormously. For saving the cable installation, the sensor is supplied by the rechargeable batteries. The purpose of the intelligent management of the energy and transmitter by means of MCU is to minimize the power consumption and prolong the working period of the sensor. In a word, the new sensor is more feasible with smaller volume, wireless communication, rechargeable batteries, low power consumption, low cost, high detector precision and easy maintenance and installation.

Lin, L.; Han, X. B.; Ding, R.; Li, G.; C-Y Lu, Steven; Hong, Q.

2005-01-01

194

Rechargeable batteries with organic radical cathodes  

Microsoft Academic Search

The first known application of stable radicals for energy storage systems is presented. A stable nitroxyl polyradical, poly (2,2,6,6-tetramethylpiperidinyloxy methacrylate) (PTMA) has been synthesized and applied to the cathode active materials in rechargeable batteries. These fabricated batteries have demonstrated an average discharge voltage of 3.5 V and a discharge capacity of 77 Ah\\/kg, which corresponds to 70% of the theoretical

K. Nakahara; S Iwasa; M Satoh; Y Morioka; J Iriyama; M Suguro; E Hasegawa

2002-01-01

195

Ampere-Hour Meter For Rechargeable Battery  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

196

Recharge monitoring in an interplaya setting  

SciTech Connect

The objective of this investigation is to monitor infiltration in response to precipitation events in an interplaya setting. The authors evaluated data gathered from the interplaya recharge monitoring installation at the Pantex Plant from March through December 1998. They monitored thermocouple psychrometer (TCP) instruments to measure water potential and time-domain reflectometry (TDR) probes to measure water content and bulk soil conductivity. Heat-dissipation sensor (HDS) instruments were monitored to supplement the TCP data.

Scanlon, B.R.; Reedy, R.C.; Liang, J. [Univ. of Texas, Austin, TX (United States). Bureau of Economic Geology

1999-03-01

197

High temperature rechargeable molten slat battery  

SciTech Connect

This patent describes a high temperature rechargeable molten salt battery. It comprises a transition metal-sulfide as the cathode, a lithium-aluminum alloy as the anode, a molten lithium salt as the electrolyte, and an alkaline earth metal sulfide as an additive to the transition metal sulfide cathode wherein the cathode mix is prepared by physically mixing the alkaline earth metal sulfide and the transition metal sulfide in the proper ratios.

Plichta, E.J.; Behl, W.

1990-09-11

198

Rechargeable batteries and battery management systems design  

Microsoft Academic Search

Estimated worldwide sales for rechargeable batteries, was around US$36 billion in 2008 and this is expected to grow towards US$51 billion by 2013. As per market reports, US demand for primary and secondary batteries will increase by 2.5% annually to 16.8 billion in 2012, while primary batteries will account for 5.8 billion with a growth rate of 3%. The insatiable

N. Kularatna

2010-01-01

199

Application of GIS Based Tools for Groundwater Recharge and Evapotranspiration Estimation: Arc-Recharge and RIPGIS-NET  

NASA Astrophysics Data System (ADS)

Water managers are increasingly concerned about the potential impact of climate variability and change on groundwater resources. Climate impacts on groundwater resources are primarily determined by altering the amount of recharge and evapotranspiration (ET). Typically, groundwater models employ temporally static recharge or ET rates with limited spatial variability across the basin. As a result most groundwater models cannot be used to assess the impacts of climate on groundwater resources. A primary challenge addressing this shortcoming is the need for spatially and temporally explicit recharge and ET model inputs. Geographic Information Systems (GIS) and spatially explicit data can be applied to develop these improved model inputs by quantifying and distributing recharge and ET across the model domain. Two ArcGIS desktop applications were developed for ArcGIS 9.2 to enhance recharge and ET estimation- Arc- Recharge and RIPGIS-NET. Arc-Recharge an ArcGIS 9.2 custom application is developed to quantify and distribute recharge along MODFLOW cells. Using spatially explicit precipitation data and Digital Elevation Model (DEM), Arc-Recharge routes water through the landscape and distributes the recharge to the appropriate groundwater model cells. RIPGIS-NET is an ArcGIS custom application that was developed to provide parameters for the RIP-ET package. RIP-ET is an improved MODFLOW ET module that simulates ET using a set of eco-physiologically based ET curves. RIPGIS-NET improves alluvial recharge estimation by providing spatially explicit information about the riparian/wetland ET. Application of Arc-Recharge and RIPGIS-NET in groundwater modeling enhances recharge and ET estimation by incorporating temporally and spatially explicit data. Using such tools, assessment of climate variability on groundwater resources will be enhanced.

Ajami, H.; Hogan, J.; Maddock, T.; Meixner, T.

2007-12-01

200

Probabilistic analysis of the effects of climate change on groundwater recharge  

Microsoft Academic Search

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

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

2010-01-01

201

Making Li-air batteries rechargeable: material challenges  

SciTech Connect

A Li-air battery could potentially provide three to five times higher energy density/specific energy than conventional batteries, thus enable the driving range of an electric vehicle comparable to a gasoline vehicle. However, making Li-air batteries rechargeable presents significant challenges, mostly related with materials. Herein, we discuss the key factors that influence the rechargeability of Li-air batteries with a focus on nonaqueous system. The status and materials challenges for nonaqueous rechargeable Li-air batteries are reviewed. These include electrolytes, cathode (electocatalysts), lithium metal anodes, and oxygen-selective membranes (oxygen supply from air). The perspective of rechargeable Li-air batteries is provided.

Shao, Yuyan; Ding, Fei; Xiao, Jie; Zhang, Jian; Xu, Wu; Park, Seh Kyu; Zhang, Jiguang; Wang, Yong; Liu, Jun

2013-02-25

202

A review of groundwater recharge under irrigated agriculture in Australia  

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

203

Geophysical Methods for Investigating Ground-Water Recharge  

USGS Publications Warehouse

While numerical modeling has revolutionized our understanding of basin-scale hydrologic processes, such models rely almost exclusively on traditional measurements?rainfall, streamflow, and water-table elevations?for calibration and testing. Model calibration provides initial estimates of ground-water recharge. Calibrated models are important yet crude tools for addressing questions about the spatial and temporal distribution of recharge. An inverse approach to recharge estimation is taken of necessity, due to inherent difficulties in making direct measurements of flow across the water table. Difficulties arise because recharging fluxes are typically small, even in humid regions, and because the location of the water table changes with time. Deep water tables in arid and semiarid regions make recharge monitoring especially difficult. Nevertheless, recharge monitoring must advance in order to improve assessments of ground-water recharge. Improved characterization of basin-scale recharge is critical for informed water-resources management. Difficulties in directly measuring recharge have prompted many efforts to develop indirect methods. The mass-balance approach of estimating recharge as the residual of generally much larger terms has persisted despite the use of increasing complex and finely gridded large-scale hydrologic models. Geophysical data pertaining to recharge rates, timing, and patterns have the potential to substantially improve modeling efforts by providing information on boundary conditions, by constraining model inputs, by testing simplifying assumptions, and by identifying the spatial and temporal resolutions needed to predict recharge to a specified tolerance in space and in time. Moreover, under certain conditions, geophysical measurements can yield direct estimates of recharge rates or changes in water storage, largely eliminating the need for indirect measures of recharge. This appendix presents an overview of physically based, geophysical methods that are currently available or under development for recharge monitoring. The material is written primarily for hydrogeologists. Uses of geophysical methods for improving recharge monitoring are explored through brief discussions and case studies. The intent is to indicate how geophysical methods can be used effectively in studying recharge processes and quantifying recharge. As such, the material constructs a framework for matching the strengths of individual geophysical methods with the manners in which they can be applied for hydrologic analyses. The appendix is organized in three sections. First, the key hydrologic parameters necessary to determine the rate, timing, and patterns of recharge are identified. Second, the basic operating principals of the relevant geophysical methods are discussed. Methods are grouped by the physical property that they measure directly. Each measured property is related to one or more of the key hydrologic properties for recharge monitoring. Third, the emerging conceptual framework for applying geophysics to recharge monitoring is presented. Examples of the application of selected geophysical methods to recharge monitoring are presented in nine case studies. These studies illustrate hydrogeophysical applications under a wide range of conditions and measurement scales, which vary from tenths of a meter to hundreds of meters. The case studies include practice-proven as well as emerging applications of geophysical methods to recharge monitoring.

Ferre, Ty P.A.; Binley, Andrew M.; Blasch, Kyle W.; Callegary, James B.; Crawford, Steven M.; Fink, James B.; Flint, Alan L.; Flint, Lorraine E.; Hoffmann, John P.; Izbicki, John A.; Levitt, Marc T.; Pool, Donald R.; Scanlon, Bridget R.

2007-01-01

204

Thin-film rechargeable lithium batteries  

SciTech Connect

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.

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

1995-06-01

205

Artificial recharge of groundwater and its role in water management  

USGS Publications Warehouse

This paper summarizes and discusses the various aspects and methods of artificial recharge with particular emphasis on its uses and potential role in water management in the Arabian Gulf region. Artificial recharge occurs when man's activities cause more water to enter an aquifer, either under pumping or non-pumping conditions, than otherwise would enter the aquifer. Use of artificial recharge can be a practical means of dealing with problems of overdraft of groundwater. Methods of artificial recharge may be grouped under two broad types: (a) water spreading techniques, and (b) well-injection techniques. Successful use of artificial recharge requires a thorough knowledge of the physical and chemical characteristics of the aquifier system, and extensive onsite experimentation and tailoring of the artificial-recharge technique to fit the local or areal conditions. In general, water spreading techniques are less expensive than well injection and large quantities of water can be handled. Water spreading can also result in significant improvement in quality of recharge waters during infiltration and movement through the unsaturated zone and the receiving aquifer. In comparison, well-injection techniques are often used for emplacement of fresh recharge water into saline aquifer zones to form a manageable lens of fresher water, which may later be partially withdrawn for use or continue to be maintained as a barrier against salt-water encroachment. A major advantage in use of groundwater is its availability, on demand to wells, from a natural storage reservoir that is relatively safe from pollution and from damage by sabotage or other hostile action. However, fresh groundwater occurs only in limited quantities in most of the Arabian Gulf region; also, it is heavily overdrafted in many areas, and receives very little natural recharge. Good use could be made of artificial recharge by well injection in replenishing and managing aquifers in strategic locations if sources of freshwater could be made available for the artificial-recharge operations. ?? 1989.

Kimrey, J.O.

1989-01-01

206

Challenges of Artificial Recharge at the Chain of Lakes  

NASA Astrophysics Data System (ADS)

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.

Zeng, X.

2004-12-01

207

Using noble gases to investigate mountain-front recharge  

USGS Publications Warehouse

Mountain-front recharge is a major component of recharge to inter-mountain basin-fill aquifers. The two components of mountain-front recharge are (1) subsurface inflow from the mountain block (subsurface inflow), and (2) infiltration from perennial and ephemeral streams near the mountain front (stream seepage). The magnitude of subsurface inflow is of central importance in source protection planning for basin-fill aquifers and in some water rights disputes, yet existing estimates carry large uncertainties. Stable isotope ratios can indicate the magnitude of mountain-front recharge relative to other components, but are generally incapable of distinguishing subsurface inflow from stream seepage. Noble gases provide an effective tool for determining the relative significance of subsurface inflow, specifically. Dissolved noble gas concentrations allow for the determination of recharge temperature, which is correlated with recharge elevation. The nature of this correlation cannot be assumed, however, and must be derived for the study area. The method is applied to the Salt Lake Valley Principal Aquifer in northern Utah to demonstrate its utility. Samples from 16 springs and mine tunnels in the adjacent Wasatch Mountains indicate that recharge temperature decreases with elevation at about the same rate as the mean annual air temperature, but is on average about 2??C cooler. Samples from 27 valley production wells yield recharge elevations ranging from the valley elevation (about 1500 m) to mid-mountain elevation (about 2500 m). Only six of the wells have recharge elevations less than 1800 m. Recharge elevations consistently greater than 2000 m in the southeastern part of the basin indicate that subsurface inflow constitutes most of the total recharge in this area. ?? 2003 Published by Elsevier Science B.V.

Manning, A.H.; Solomon, D.K.

2003-01-01

208

Lithium Metal Anodes for Rechargeable Batteries  

SciTech Connect

Rechargeable lithium metal batteries have much higher energy density than those of lithium ion batteries using graphite anode. Unfortunately, uncontrollable dendritic lithium growth inherent in these batteries (upon repeated charge/discharge cycling) and limited Coulombic efficiency during lithium deposition/striping has prevented their practical application over the past 40 years. With the emerging of post Li-ion batteries, safe and efficient operation of lithium metal anode has become an enabling technology which may determine the fate of several promising candidates for the next generation of energy storage systems, including rechargeable Li-air battery, Li-S battery, and Li metal battery which utilize lithium intercalation compounds as cathode. In this work, various factors which affect the morphology and Coulombic efficiency of lithium anode will be analyzed. Technologies used to characterize the morphology of lithium deposition and the results obtained by modeling of lithium dendrite growth will also be reviewed. At last, recent development in this filed and urgent need in this field will also be discussed.

Xu, Wu; Wang, Jiulin; Ding, Fei; Chen, Xilin; Nasybulin, Eduard N.; Zhang, Yaohui; Zhang, Jiguang

2014-02-28

209

Monitoring Groundwater Recharge In the Sierra Nevada Mountains For  

E-print Network

Monitoring Groundwater Recharge In the Sierra Nevada Mountains For Impact On Hydrologic Resources The Issue Snowmelt is a significant source of replenishing groundwater resources in the western United States. In addition, this groundwater recharge process is typically a major contributor to streamflow

210

Current collectors for rechargeable Li-Air batteries  

SciTech Connect

Here we report the negative influence of porous nickel foam for use as current collectors in rechargeable Li-air batteries. Uncoated nickel foam promotes the decomposition of LiPF6-organic carbonate electrolytes under normal charging conditions reported for rechargeable Li-air cells. We have identified Ni free porous carbon supports as more appropriate cathode current collectors.

Veith, Gabriel M [ORNL; Dudney, Nancy J [ORNL

2011-01-01

211

ESTIMATION OF GROUND WATER RECHARGE USING SOIL MOISTURE BALANCE APPROACH  

E-print Network

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

Kumar, C.P.

212

Estimating infiltration recharge using a response function model  

Microsoft Academic Search

Rainfall infiltration influences both the quantity and quality of groundwater systems. The knowledge of the process of infiltration recharge is of great importance to the management of groundwater systems and the hydraulically connected streams. In this study, a response function model is developed to estimate soil water flux at the water table or the process of infiltration recharge from rainfall

Jinquan Wu; Renduo Zhang; Jinzhong Yang

1997-01-01

213

Determining the recharge mode of Sahelian aquifers using water isotopes  

Microsoft Academic Search

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

Pierre Girard; Claude Hillaire-Marcel; Marie Solange Oga

1997-01-01

214

Probabilistic estimation and prediction of groundwater recharge in a semi-arid environment  

E-print Network

Quantifying and characterizing groundwater recharge are critical for water resources management. Unfortunately, low recharge rates are difficult to resolve in dry environments, where groundwater is often most important. ...

Ng, Gene-Hua Crystal

2009-01-01

215

Groundwater recharge rate and zone structure estimation using PSOLVER algorithm.  

PubMed

The quantification of groundwater recharge is an important but challenging task in groundwater flow modeling because recharge varies spatially and temporally. The goal of this study is to present an innovative methodology to estimate groundwater recharge rates and zone structures for regional groundwater flow models. Here, the unknown recharge field is partitioned into a number of zones using Voronoi Tessellation (VT). The identified zone structure with the recharge rates is associated through a simulation-optimization model that couples MODFLOW-2000 and the hybrid PSOLVER optimization algorithm. Applicability of this procedure is tested on a previously developed groundwater flow model of the Tahtal? Watershed. Successive zone structure solutions are obtained in an additive manner and penalty functions are used in the procedure to obtain realistic and plausible solutions. One of these functions constrains the optimization by forcing the sum of recharge rates for the grid cells that coincide with the Tahtal? Watershed area to be equal to the areal recharge rate determined in the previous modeling by a separate precipitation-runoff model. As a result, a six-zone structure is selected as the best zone structure that represents the areal recharge distribution. Comparison to results of a previous model for the same study area reveals that the proposed procedure significantly improves model performance with respect to calibration statistics. The proposed identification procedure can be thought of as an effective way to determine the recharge zone structure for groundwater flow models, in particular for situations where tangible information about groundwater recharge distribution does not exist. PMID:23746002

Ayvaz, M Tamer; Eli, Alper

2014-01-01

216

Determining the recharge mode of Sahelian aquifers using water isotopes  

NASA Astrophysics Data System (ADS)

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.

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

1997-10-01

217

Nanocarbon networks for advanced rechargeable lithium batteries.  

PubMed

Carbon is one of the essential elements in energy storage. In rechargeable lithium batteries, researchers have considered many types of nanostructured carbons, such as carbon nanoparticles, carbon nanotubes, graphene, and nanoporous carbon, as anode materials and, especially, as key components for building advanced composite electrode materials. Nanocarbons can form efficient three-dimensional conducting networks that improve the performance of electrode materials suffering from the limited kinetics of lithium storage. Although the porous structure guarantees a fast migration of Li ions, the nanocarbon network can serve as an effective matrix for dispersing the active materials to prevent them from agglomerating. The nanocarbon network also affords an efficient electron pathway to provide better electrical contacts. Because of their structural stability and flexibility, nanocarbon networks can alleviate the stress and volume changes that occur in active materials during the Li insertion/extraction process. Through the elegant design of hierarchical electrode materials with nanocarbon networks, researchers can improve both the kinetic performance and the structural stability of the electrode material, which leads to optimal battery capacity, cycling stability, and rate capability. This Account summarizes recent progress in the structural design, chemical synthesis, and characterization of the electrochemical properties of nanocarbon networks for Li-ion batteries. In such systems, storage occurs primarily in the non-carbon components, while carbon acts as the conductor and as the structural buffer. We emphasize representative nanocarbon networks including those that use carbon nanotubes and graphene. We discuss the role of carbon in enhancing the performance of various electrode materials in areas such as Li storage, Li ion and electron transport, and structural stability during cycling. We especially highlight the use of graphene to construct the carbon conducting network for alloy anodes, such as Si and Ge, to accelerate electron transport, alleviate volume change, and prevent the agglomeration of active nanoparticles. Finally, we describe the power of nanocarbon networks for the next generation rechargeable lithium batteries, including Li-S, Li-O(2), and Li-organic batteries, and provide insights into the design of ideal nanocarbon networks for these devices. In addition, we address the ways in which nanocarbon networks can expand the applications of rechargeable lithium batteries into the emerging fields of stationary energy storage and transportation. PMID:22953777

Xin, Sen; Guo, Yu-Guo; Wan, Li-Jun

2012-10-16

218

Lithium electronic environments in rechargeable battery electrodes  

NASA Astrophysics Data System (ADS)

This work investigates the electronic environments of lithium in the electrodes of rechargeable batteries. The use of electron energy-loss spectroscopy (EELS) in conjunction with transmission electron microscopy (TEM) is a novel approach, which when coupled with conventional electrochemical experiments, yield a thorough picture of the electrode interior. Relatively few EELS experiments have been preformed on lithium compounds owing to their reactivity. Experimental techniques were established to minimize sample contamination and control electron beam damage to studied compounds. Lithium hydroxide was found to be the most common product of beam damaged lithium alloys. Under an intense electron beam, halogen atoms desorbed by radiolysis in lithium halides. EELS spectra from a number of standard lithium compounds were obtained in order to identify the variety of spectra encountered in lithium rechargeable battery electrodes. Lithium alloys all displayed characteristically broad Li K-edge spectra, consistent with transitions to continuum states. Transitions to bound states were observed in the Li K and oxygen K-edge spectra of lithium oxides. Lithium halides were distinguished by their systematic chemical shift proportional to the anion electronegativity. Good agreement was found with measured lithium halide spectra and electron structure calculations using a self-consistant multiscattering code. The specific electrode environments of LiC6, LiCoO2, and Li-SnO were investigated. Contrary to published XPS predictions, lithium in intercalated graphite was determined to be in more metallic than ionic. We present the first experimental evidence of charge compensation by oxygen ions in deintercalated LiCoO2. Mossbauer studies on cycled Li-SnO reveal severely defective structures on an atomic scale. Metal hydride systems are presented in the appendices of this thesis. The mechanical alloying of immiscible Fe and Mg powders resulted in single-phase bcc alloys of less than 20 at% Mg. Kinetic studies on LaNi5-xSn x alloys proved that the mass transfer of hydrogen through these alloys was not hindered with increasing Sn substitutions for Ni. Collaborations with Energizer(c) found LanNi4.7Sn0.3 alloys to possess limited utility in rechargeable nickel-metal-hydride sealed-cell batteries.

Hightower, Adrian

219

Development of structural stability and the electrochemical performances of La substituted spinel LiMn 2O 4 cathode materials for rechargeable lithium-ion batteries  

Microsoft Academic Search

The LiLaxMn2?xO4 (x=0.00 to 0.10) cathode materials for rechargeable lithium ion batteries were synthesized by simple solgel technique using aqueous solutions of metal nitrates and succinic acid as the chelating agent. The gel precursors of metal succinates were dried in vacuum oven for 10h at 110C. After drying, the gel precursors were ground and heated at 900C. The structural characterization

D. Arumugam; G. Paruthimal Kalaignan; P. Manisankar

2008-01-01

220

Advances in development of rechargeable mitochondrial antioxidants.  

PubMed

It has been about 15 years since the introduction of the rechargeable mitochondria-targeted antioxidants (RMA). Two major groups have been developing RMA of the MitoQ and SkQ types independently, and many additional trials have been done by other researchers. This has provided solid preclinical evidence of RMA efficacy in various models. Human trials of systemic MitoQ were not followed by further advances, but the safety of MitoQ and, most likely, other RMA in humans has been demonstrated. A prooxidant effect at higher concentrations of RMA was described. For RMA of the SkQ type, a large window between anti- and prooxidant concentrations was observed, which makes SkQs promising as potential medicines. Significant RMA-induced improvements in many diseases that do not have an accepted treatment have been described. This justifies further clinical trials of RMA. PMID:25149221

Lukashev, Alexander N; Skulachev, Maxim V; Ostapenko, Victoria; Savchenko, Alla Yu; Pavshintsev, V V; Skulachev, Vladimir P

2014-01-01

221

Oxygen electrodes for rechargeable alkaline fuel cells  

NASA Technical Reports Server (NTRS)

Electrocatalysts and supports for the positive electrode of moderate temperature single unit rechargeable alkaline fuel cells were investigated and developed. The electrocatalysts are defined as the material with a higher activity for the oxygen electrode reaction than the support. Advanced development will require that the materials be prepared in high surface area forms, and may also entail integration of various candidate materials. Eight candidate support materials and seven electrocatalysts were investigated. Of the 8 support, 3 materials meet the preliminary requirements in terms of electrical conductivity and stability. Emphasis is now on preparing in high surface area form and testing under more severe corrosion stress conditions. Of the 7 electrocatalysts prepared and evaluated, at least 5 materials remain as potential candidates. The major emphasis remains on preparation, physical characterization and electrochemical performance testing.

Swette, Larry; Giner, Jose

1987-01-01

222

Rechargeable metal hydrides for spacecraft application  

NASA Technical Reports Server (NTRS)

Storing hydrogen on board the Space Station presents both safety and logistics problems. Conventional storage using pressurized bottles requires large masses, pressures, and volumes to handle the hydrogen to be used in experiments in the U.S. Laboratory Module and residual hydrogen generated by the ECLSS. Rechargeable metal hydrides may be competitive with conventional storage techniques. The basic theory of hydride behavior is presented and the engineering properties of LaNi5 are discussed to gain a clear understanding of the potential of metal hydrides for handling spacecraft hydrogen resources. Applications to Space Station and the safety of metal hydrides are presented and compared to conventional hydride storage. This comparison indicates that metal hydrides may be safer and require lower pressures, less volume, and less mass to store an equivalent mass of hydrogen.

Perry, J. L.

1988-01-01

223

Advanced rechargeable sodium batteries with novel cathodes  

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

224

Polymer Energy Rechargeable System (PERS) Development Program  

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

225

Thin-film rechargeable lithium batteries  

SciTech Connect

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.

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

1994-11-01

226

Advanced rechargeable sodium batteries with novel cathodes  

NASA Technical Reports Server (NTRS)

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).

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

1989-01-01

227

Spinel electrodes for rechargeable lithium batteries.  

SciTech Connect

This paper gives a historical account of the development of spinel electrodes for rechargeable lithium batteries. Research in the late 1970's and early 1980's on high-temperature . Li/Fe{sub 3}O{sub 4} cells led to the evaluation of lithium spinels Li[B{sub 2}]X{sub 4} at room temperature (B = metal cation). This work highlighted the importance of the [B{sub 2}]X{sub 4}spinel framework as a host electrode structure and the ability to tailor the cell voltage by selection of different B cations. Examples of lithium-ion cells that operate with spinel anode/spinel cathode couples are provided. Particular attention is paid to spinels within the solid solution system Li{sub 1+x}Mn{sub 2-x}O{sub 4} (0 {le} x {le} 0.33).

Thackeray, M. M.

1999-11-10

228

Monitoring of recharge water quality under woodland  

NASA Astrophysics Data System (ADS)

The study compares the quality of groundwater in the water table zone and soil moisture below the root zone, under woodland, with the quality of the regional precipitation. The water quality under forest shows evidence of the effect of atmospheric deposition of acidic components (e.g. SO 2) and ammonia volatilized from land and feed lots. Detailed chemical profiles of the upper meter of groundwater under different plots of forest, at varying distances from cultivated land, were obtained with a multilayer sampler, using the dialysis-cell method. Porous ceramic cups and a vacuum method were used to obtain soil moisture samples at 1.20 m depth under various types of trees, an open spot and arable land, for the period of a year. The investigation took place in the recharge area of a pumping station with mainly mixed forest, downwind of a vast agricultural area with high ammonia volatilization and underlain by an ice-deformed aquifer. Very high NO -3 concentrations were observed in soil moisture and groundwater (up to 21 mg Nl -1) under coniferous forest, especially in the border zone. This raises the question of the dilution capacity of recharge water under woodland in relation to the polluted groundwater under farming land. The buffering capacity of the unsaturated zone varies substantially and locally a low pH (4.5) was observed in groundwater. The large variability of leachate composition on different scales under a forest and the lesser but still significant concentration differences in the groundwater prove the importance of a monitoring system for the actual solute flux into the groundwater.

Krajenbrink, G. J. W.; Ronen, D.; Van Duijvenbooden, W.; Magaritz, M.; Wever, D.

1988-03-01

229

Rechargeable thin-film lithium batteries  

SciTech Connect

Rechargeable thin-film batteries consisting of lithium metal anodes, an amorphous inorganic electrolyte, and cathodes of lithium intercalation compounds have recently been developed. The batteries, which are typically less than 6-{mu}m thick, can be fabricated to any specified size, large or small, onto a variety of substrates including ceramics, semiconductors, and plastics. The cells that have been investigated include Li-TiS{sub 2}, Li-V{sub 2}O{sub 5}, and Li-Li{sub x}Mn{sub 2}O{sub 4}, with open circuit voltages at full charge of about 2.5, 3.6, and 4.2, respectively. The development of these batteries would not have been possible without the discovery of a new thin-film lithium electrolyte, lithium phosphorus oxynitride, that is stable in contact with metallic lithium at these potentials. Deposited by rf magnetron sputtering of Li{sub 3}PO{sub 4} in N{sub 2}, this material has a typical composition of Li{sub 2.9}PO{sub 3.3}N{sub 0.46} and a conductivity at 25{degrees}C of 2 {mu}S/cm. The maximum practical current density obtained from the thin-film cells is limited to about 100 {mu}A/cm{sup 2} due to a low diffusivity of Li{sup +} ions in the cathodes. In this work, the authors present a short review of their work on rechargeable thin-film lithium batteries.

Bates, J.B.; Gruzalski, G.R.; Dudney, N.J.; Luck, C.F.; Yu, Xiaohua

1993-08-01

230

Echo Meadows Project Winter Artificial Recharge.  

SciTech Connect

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.

Ziari, Fred

2002-12-19

231

Geostatistical estimates of future recharge for the Death Valley region  

SciTech Connect

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.

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

1998-12-01

232

Stable isotope tracers: natural and anthropogenic recharge, Orange County, California  

NASA Astrophysics Data System (ADS)

Stable isotopic techniques have been utilized to locate occurrences and trace movements of a variety of naturally and anthropogenically recharged waters in aquifers of Orange County, California. This basin is of particular interest not only because it provides the dominant water supply for the two million residents of this well-populated county, but also because it is representative of a common arid environment where natural recharge is dominated by distant, high-elevation precipitation transported by a major river. Such arid basins are particularly sensitive to climatic and anthropogenic disturbance of their recharge and their subsurface hydrology. In order to identify distinctive waters, oxygen and hydrogen stable isotope ratios from Orange County wells have been compared with a regional database including an array of surface water samples representative of watershed runoff. Four distinctive subsurface water types can be resolved. Waters of "local" rainfall and imported, "Colorado" River aqueduct origins are easily distinguished from dominant, "native" Santa Ana river compositions by use of hydrogen and oxygen stable isotope analysis. Recent human interference with Santa Ana river flow and recharge is also marginally resolvable by isotopic techniques. Distinguishable isotopic signatures of "recent" Santa Ana recharge appear to be due to evaporative loss, perhaps during storage in the Prado Reservoir or in percolation ponds, prior to recharge into Orange County aquifers. Characterization of traceable isotopic signatures of distinct natural and anthropogenic recharge components provides a major advance towards use of such techniques for developing a well constrained, three-dimensional hydrologic model for this complex basin.

Williams, Alan E.

1997-12-01

233

Effects of artificial recharge on the Ogallala aquifer, Texas  

USGS Publications Warehouse

Four recharge tests were conducted by injecting water from playa lakes through wells into the Ogallala Formation. Injection was by gravity flow and by pumping under pressure. At one site, 34-acre feet of water was injected by gravity and produced a significant increase in yield of the well. At a second site, gravity injection of only 0.58 acre-foot caused a significant decrease in permeability due to plugging by suspended sediment. At two other sites, injection by pumping 6 and 14 acre-feet respectively, resulted in discharge of water at the surface and in perching of water above the water table. Differences in success of recharge were largely due to aquifer lithology and, therefore, the type of permeability; the concentration of suspended solids in the recharge water; and the injection technique. The injection technique can be controlled and the concentration of suspended solids can be minimized by treatment, but the site for well recharge will accept water most rapidly if it is selected on the basis of a favorable geohydrologic environment. Geophysical logs were used to study the effect of aquifer lithology on recharge and to understand the movement of injected water. Temperature logs were particularly useful in tracing the movement of recharged water. Natural-gamma, gamma-gamma, and neutron logs provided important data on lithology and porosity in the aquifer and changes in porosity and water distribution resulting from recharge. Effective recharge of the Ogallala Formation, using water from playa lakes, is possible where geohydrologic conditions are favorable and the recharge system is properly constructed.

Brown, Richmond Flint; Keys, W.S.

1985-01-01

234

Mountain-Block Hydrology and Mountain-Front Recharge* John L. Wilson and Huade Guan  

E-print Network

Mountain-Block Hydrology and Mountain-Front Recharge* John L. Wilson and Huade Guan New Mexico of recharge to basin aquifers oc- curs along the mountain front. Traditionally called "mountain-front recharge, mountain-front recharge estimates are based on the general pre- cipitation characteristics of the mountain

Texas at San Antonio, University of

235

Potassium barium hexacyanoferrate - A potential cathode material for rechargeable calcium ion batteries  

NASA Astrophysics Data System (ADS)

Potassium barium hexacyanoferrate (K2BaFe(CN)6) was investigated as a cathode material for reversible Ca2+ ion insertion/extraction type rechargeable battery using non-aqueous electrolytes. The electrochemical performance of K2BaFe(CN)6was evaluated using cyclic voltammetry and galvanic cycling at ambient temperature. It is shown that addition of water led to significant enhancement in intercalation and de-intercalation of Ca2+ ions, leading to improved charge/discharge capacity. The enhancement in performance is attributed to formation of solvation spheres around the intercalating Ca2+ ions which provide screening from the electrostatic charges of the BaFe(CN)6 lattice. A reversible capacity of 55.8 mA hr g-1 and a coulombic efficiency of 93.8% was demonstrated at the end of 30 charge/discharge cycles.

Padigi, Prasanna; Goncher, Gary; Evans, David; Solanki, Raj

2015-01-01

236

ENGINEERING ECONOMIC ANALYSIS OF A PROGRAM FOR ARTIFICIAL GROUNDWATER RECHARGE.  

USGS Publications Warehouse

This study describes and demonstrates two alternate methods for evaluating the relative costs and benefits of artificial groundwater recharge using percolation ponds. The first analysis considers the benefits to be the reduction of pumping lifts and land subsidence; the second considers benefits as the alternative costs of a comparable surface delivery system. Example computations are carried out for an existing artificial recharge program in Santa Clara Valley in California. A computer groundwater model is used to estimate both the average long term and the drought period effects of artificial recharge in the study area. Results indicate that the costs of artificial recharge are considerably smaller than the alternative costs of an equivalent surface system. Refs.

Reichard, Eric G.; Bredehoeft, John D.

1984-01-01

237

Transportation Center Seminar "Electric Vehicle Recharging: Decision Support  

E-print Network

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;

Bustamante, Fabián E.

238

Reliability of Rechargeable Batteries in a Photovoltaic Power Supply System  

SciTech Connect

We investigate the reliability If a rechargeable battery acting as the energy storage component in a photovoltaic power supply system. A model system was constructed for this that includes the solar resource, the photovoltaic power supp Iy system, the rechargeable battery and a load. The solar resource and the system load are modeled as SI ochastic processes. The photovoltaic system and the rechargeable battery are modeled deterministically, imd an artificial neural network is incorporated into the model of the rechargeable battery to simulate dartage that occurs during deep discharge cycles. The equations governing system behavior are solved simultaneously in the Monte Carlo framework and a fwst passage problem is solved to assess system reliability.

Barney, P.; Jungst, R.G., Ingersoll, D.; O'Gorman, C.; Paez, T.L.; Urbina, A.

1998-11-30

239

Bipolar rechargeable lithium battery for high power applications  

NASA Technical Reports Server (NTRS)

Viewgraphs of a discussion on bipolar rechargeable lithium battery for high power applications are presented. Topics covered include cell chemistry, electrolytes, reaction mechanisms, cycling behavior, cycle life, and cell assembly.

Hossain, Sohrab; Kozlowski, G.; Goebel, F.

1993-01-01

240

Improved zinc electrode and rechargeable zinc-air battery  

DOEpatents

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.

Ross, P.N. Jr.

1988-06-21

241

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 ...

242

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

SciTech Connect

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.

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

2010-10-27

243

Cryogenic Transport of High-Pressure-System Recharge Gas  

NASA Technical Reports Server (NTRS)

A method of relatively safe, compact, efficient recharging of a high-pressure room-temperature gas supply has been proposed. In this method, the gas would be liquefied at the source for transport as a cryogenic fluid at or slightly above atmospheric pressure. Upon reaching the destination, a simple heating/expansion process would be used to (1) convert the transported cryogenic fluid to the room-temperature, high-pressure gaseous form in which it is intended to be utilized and (2) transfer the resulting gas to the storage tank of the system to be recharged. In conventional practice for recharging high-pressure-gas systems, gases are transported at room temperature in high-pressure tanks. For recharging a given system to a specified pressure, a transport tank must contain the recharge gas at a much higher pressure. At the destination, the transport tank is connected to the system storage tank to be recharged, and the pressures in the transport tank and the system storage tank are allowed to equalize. One major disadvantage of the conventional approach is that the high transport pressure poses a hazard. Another disadvantage is the waste of a significant amount of recharge gas. Because the transport tank is disconnected from the system storage tank when it is at the specified system recharge pressure, the transport tank still contains a significant amount of recharge gas (typically on the order of half of the amount transported) that cannot be used. In the proposed method, the cryogenic fluid would be transported in a suitably thermally insulated tank that would be capable of withstanding the recharge pressure of the destination tank. The tank would be equipped with quick-disconnect fluid-transfer fittings and with a low-power electric heater (which would not be used during transport). In preparation for transport, a relief valve would be attached via one of the quick-disconnect fittings (see figure). During transport, the interior of the tank would be kept at a near-ambient pressure far below the recharge pressure. As leakage of heat into the tank caused vaporization of the cryogenic fluid, the resulting gas would be vented through the relief valve, which would be set to maintain the pressure in the tank at the transport value. Inasmuch as the density of a cryogenic fluid at atmospheric pressure greatly exceeds that of the corresponding gas in a practical high-pressure tank at room temperature, a tank for transporting a given mass of gas according to the proposed method could be smaller (and, hence, less massive) than is a tank needed for transporting the same mass of gas according to the conventional method.

Ungar, Eugene K,; Ruemmele, Warren P.; Bohannon, Carl

2010-01-01

244

Fate of human viruses in groundwater recharge systems  

Microsoft Academic Search

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

J. M. Vaughn; E. F. Landry

1980-01-01

245

The chemistry and status of rechargeable molten-salt batteries  

Microsoft Academic Search

The chemistry and the state of development of rechargeable molten salt cells and batteries of current interest are reviewed in this work. Molten-salt cells offer the most attractive combination of high specific energy (100-200 Wh\\/kg), high specific power (50-200 W\\/kg), and long cycle life (300-1500 cycles) of any rechargeable cells under investigation at this time. It is these important features

E. J. Cairns; G. Mamantov; R. P. Tischer; D. R. Vissers

1983-01-01

246

Recharge signal identification based on groundwater level observations.  

PubMed

This study applied a method of the rotated empirical orthogonal functions to directly decompose the space-time groundwater level variations and determine the potential recharge zones by investigating the correlation between the identified groundwater signals and the observed local rainfall records. The approach is used to analyze the spatiotemporal process of piezometric heads estimated by Bayesian maximum entropy method from monthly observations of 45 wells in 1999-2007 located in the Pingtung Plain of Taiwan. From the results, the primary potential recharge area is located at the proximal fan areas where the recharge process accounts for 88% of the spatiotemporal variations of piezometric heads in the study area. The decomposition of groundwater levels associated with rainfall can provide information on the recharge process since rainfall is an important contributor to groundwater recharge in semi-arid regions. Correlation analysis shows that the identified recharge closely associates with the temporal variation of the local precipitation with a delay of 1-2 months in the study area. PMID:22016042

Yu, Hwa-Lung; Chu, Hone-Jay

2012-10-01

247

Estimating aquifer channel recharge using optical data interpretation.  

PubMed

Recharge through intermittent and ephemeral stream channels is believed to be a primary aquifer recharge process in arid and semiarid environments. The intermittent nature of precipitation and flow events in these channels, and their often remote locations, makes direct flow and loss measurements difficult and expensive. Airborne and satellite optical images were interpreted to evaluate aquifer recharge due to stream losses on the Frio River in south-central Texas. Losses in the Frio River are believed to be a major contributor of recharge to the Edwards Aquifer. The results of this work indicate that interpretation of readily available remote sensing optical images can offer important insights into the spatial distribution of aquifer recharge from losing streams. In cases where upstream gauging data are available, simple visual analysis of the length of the flowing reach downstream from the gauging station can be used to estimate channel losses. In the case of the Frio River, the rate of channel loss estimated from the length of the flowing reach at low flows was about half of the loss rate calculated from in-stream gain-loss measurements. Analysis based on water-surface width and channel slope indicated that losses were mainly in a reach downstream of the mapped recharge zone. The analysis based on water-surface width, however, did not indicate that this method could yield accurate estimates of actual flow in pool and riffle streams, such as the Frio River and similar rivers draining the Edwards Plateau. PMID:21434908

Walter, Gary R; Necsoiu, Marius; McGinnis, Ronald

2012-01-01

248

Rechargeable Magnesium Batteries: Low-Cost Rechargeable Magnesium Batteries with High Energy Density  

SciTech Connect

BEEST Project: Pellion Technologies is developing rechargeable magnesium batteries that would enable an EV to travel 3 times farther than it could using Li-ion batteries. Prototype magnesium batteries demonstrate excellent electrochemical behavior; delivering thousands of charge cycles with very little fade. Nevertheless, these prototypes have always stored too little energy to be commercially viable. Pellion Technologies is working to overcome this challenge by rapidly screening potential storage materials using proprietary, high-throughput computer models. To date, 12,000 materials have been identified and analyzed. The resulting best materials have been electrochemically tested, yielding several very promising candidates.

None

2010-10-01

249

Wearable textile battery rechargeable by solar energy.  

PubMed

Wearable electronics represent a significant paradigm shift in consumer electronics since they eliminate the necessity for separate carriage of devices. In particular, integration of flexible electronic devices with clothes, glasses, watches, and skin will bring new opportunities beyond what can be imagined by current inflexible counterparts. Although considerable progresses have been seen for wearable electronics, lithium rechargeable batteries, the power sources of the devices, do not keep pace with such progresses due to tenuous mechanical stabilities, causing them to remain as the limiting elements in the entire technology. Herein, we revisit the key components of the battery (current collector, binder, and separator) and replace them with the materials that support robust mechanical endurance of the battery. The final full-cells in the forms of clothes and watchstraps exhibited comparable electrochemical performance to those of conventional metal foil-based cells even under severe folding-unfolding motions simulating actual wearing conditions. Furthermore, the wearable textile battery was integrated with flexible and lightweight solar cells on the battery pouch to enable convenient solar-charging capabilities. PMID:24164580

Lee, Yong-Hee; Kim, Joo-Seong; Noh, Jonghyeon; Lee, Inhwa; Kim, Hyeong Jun; Choi, Sunghun; Seo, Jeongmin; Jeon, Seokwoo; Kim, Taek-Soo; Lee, Jung-Yong; Choi, Jang Wook

2013-01-01

250

Advanced rechargeable sodium batteries with novel cathodes  

NASA Technical Reports Server (NTRS)

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 were realized in practical batteries. Other technological advantages include its chemical simplicity, absence of self-discharge, and long cycle life possibility. More recently, other high temperature sodium batteries have come into the spotlight. These systems can be described as follow: Na/Beta Double Prime-Al2O3/NaAlCl4/Metal Dichloride Sodium/metal dichloride systems are colloquially known as the zebra system and are currently being developed for traction and load leveling applications. The sodium-metal dichloride systems appear to offer many of the same advantages of the Na/S system, especially in terms of energy density and chemical simplicity. The metal dichloride systems offer increased safety and good resistance to overcharge and operate over a wide range of temperatures from 150 to 400 C with less corrosion problems.

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

1989-01-01

251

Rechargeable thin-film lithium batteries  

SciTech Connect

Rechargeable thin-film batteries consisting of lithium metal anodes, an amorphous inorganic electrolyte, and cathodes of lithium intercalation compounds have been fabricated and characterized. These include Li-TiS{sub 2}, Li-V{sub 2}O{sub 5}, and Li-Li{sub x}Mn{sub 2}O{sub 4} cells with open circuit voltages at full charge of about 2.5 V, 3.7 V, and 4.2 V, respectively. The realization of these robust cells, which can be cycled thousands of times, was possible because of the stability of the amorphous lithium electrolyte, lithium phosphorus oxynitride. This material has a typical composition of Li{sub 2.9}PO{sub 3.3}N{sub 0.46}and a conductivity at 25 C of 2 {mu}S/cm. The thin-film cells have been cycled at 100% depth of discharge using current densities of 5 to 100 {mu}A/cm{sup 2}. Over most of the charge-discharge range, the internal resistance appears to be dominated by the cathode, and the major source of the resistance is the diffusion of Li{sup +} ions from the electrolyte into the cathode. Chemical diffusion coefficients were determined from ac impedance measurements.

Bates, J.B.; Gruzalski, G.R.; Dudney, N.J.; Luck, C.F.; Yu, X.

1993-09-01

252

Thin-film rechargeable lithium batteries  

SciTech Connect

Rechargeable thin-films batteries with lithium metal anodes, an amorphous inorganic electrolyte, and cathodes of lithium intercalation compounds have been fabricated and characterized. The cathodes include TiS{sub 2}, the {omega} phase of V{sub 2}O{sub 5}, and the cubic spinel Li{sub x}Mn{sub 2}O{sub 4} with open circuit voltages at full charge of about 2.5 V, 3.7 V, and 4.2 V, respectively. The development of these robust cells, which can be cycled thousands of times, was possible because of the stability of the amorphous lithium electrolyte, lithium phosphorus oxynitride. This material has a typical composition of Li{sub 2.9}PO{sub 3.3}N{sub 0.46} and a conductivity at 25 C of 2 {mu}S/cm. Thin-film cells have been cycled at 100% depth of discharge using current densities of 2 to 100 {mu}A/cm{sup 2}. The polarization resistance of the cells is due to the slow insertion rate of Li{sup +} ions into the cathode. Chemical diffusion coefficients for Li{sup +} ions in the three types of cathodes have been estimated from the analysis of ac impedance measurements.

Bates, J.B.; Gruzalski, G.R.; Dudney, N.J.; Luck, C.F.; Yu, X.

1993-11-01

253

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

E-print Network

2/24/2014 Micro-Windmills to Recharge Cell Phones http://www.jadecadelina.com/innovation/micro & 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

Chiao, Jung-Chih

254

4/6/2014 Micro Windmill Recharges Phone Batteries | Solar Feeds http://www.solarfeeds.com/micro-windmill-recharges-phone-batteries/ 1/3  

E-print Network

4/6/2014 Micro Windmill Recharges Phone Batteries | Solar Feeds http://www.solarfeeds.com/micro-windmill-recharges-phone-batteries/ 1/3 Micro Windmill Recharges Phone Batteries 15 January of 2014 by SolarFeeds A UT Arlington the electricity that could be collected by the cell phone's battery. Rao's works in micro-robotic devices

Chiao, Jung-Chih

255

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

USGS Publications Warehouse

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.

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

2007-01-01

256

Oxygen electrodes for rechargeable alkaline fuel cells  

NASA Technical Reports Server (NTRS)

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.

Swette, L.; Kackley, N.

1989-01-01

257

Design and simulation of lithium rechargeable batteries  

SciTech Connect

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.

Doyle, C.M.

1995-08-01

258

Arsenic release during managed aquifer recharge (MAR)  

NASA Astrophysics Data System (ADS)

The mobilization and addition of geogenic trace metals to groundwater is typically caused by anthropogenic perturbations of the physicochemical conditions in the aquifer. This can add dangerously high levels of toxins to groundwater, thus compromising its use as a source of drinking water. In several regions world-wide, aquifer storage and recovery (ASR), a form of managed aquifer recharge (MAR), faces the problem of arsenic release due to the injection of oxygenated storage water. To better understand this process we coupled geochemical reactive transport modeling to bench-scale leaching experiments to investigate and verify the mobilization of geogenic arsenic (As) under a range of redox conditions from an arsenic-rich pyrite bearing limestone aquifer in Central Florida. Modeling and experimental observations showed similar results and confirmed the following: (1) native groundwater and aquifer matrix, including pyrite, were in chemical equilibrium, thus preventing the release of As due to pyrite dissolution under ambient conditions; (2) mixing of oxygen-rich surface water with oxygen-depleted native groundwater changed the redox conditions and promoted the dissolution of pyrite, and (3) the behavior of As along a flow path was controlled by a complex series of interconnected reactions. This included the oxidative dissolution of pyrite and simultaneous sorption of As onto neo-formed hydrous ferric oxides (HFO), followed by the reductive dissolution of HFO and secondary release of adsorbed As under reducing conditions. Arsenic contamination of drinking water in these systems is thus controlled by the re-equilibration of the system to more reducing conditions rather than a purely oxidative process.

Pichler, T.; Lazareva, O.; Druschel, G.

2013-12-01

259

Thermal Methods for Investigating Ground-Water Recharge  

USGS Publications Warehouse

Recharge of aquifers within arid and semiarid environments is defined as the downward flux of water across the regional water table. The introduction of recharging water at the land surface can occur at discreet locations, such as in stream channels, or be distributed over the landscape, such as across broad interarroyo areas within an alluvial ground-water basin. The occurrence of recharge at discreet locations is referred to as focused recharge, whereas the occurrence of recharge over broad regions is referred to as diffuse recharge. The primary interest of this appendix is focused recharge, but regardless of the type of recharge, estimation of downward fluxes is essential to its quantification. Like chemical tracers, heat can come from natural sources or be intentionally introduced to infer transport properties and aquifer recharge. The admission and redistribution of heat from natural processes such as insolation, infiltration, and geothermal activity can be used to quantify subsurface flow regimes. Heat is well suited as a ground-water tracer because it provides a naturally present dynamic signal and is relatively harmless over a useful range of induced perturbations. Thermal methods have proven valuable for recharge investigations for several reasons. First, theoretical descriptions of coupled water-and-heat transport are available for the hydrologic processes most often encountered in practice. These include land-surface mechanisms such as radiant heating from the sun, radiant cooling into space, and evapotranspiration, in addition to the advective and conductive mechanisms that usually dominate at depth. Second, temperature is theoretically well defined and readily measured. Third, thermal methods for depths ranging from the land surface to depths of hundreds of meters are based on similar physical principles. Fourth, numerical codes for simulating heat and water transport have become increasingly reliable and widely available. Direct measurement of water flux in the subsurface is difficult, prompting investigators to pursue indirect methods. Geophysical approaches that exploit the coupled relation between heat and water transport provide an attractive class of methods that have become widely used in investigations of recharge. This appendix reviews the application of heat to the problem of recharge estimation. Its objective is to provide a fairly complete account of the theoretical underpinnings together with a comprehensive review of thermal methods in practice. Investigators began using subsurface temperatures to delineate recharge areas and infer directions of ground-water flow around the turn of the 20th century. During the 1960s, analytical and numerical solutions for simplified heat- and fluid-flow problems became available. These early solutions, though one-dimensional and otherwise restricted, provided a strong impetus for applying thermal methods to problems of liquid and vapor movement in systems ranging from soils to geothermal reservoirs. Today?s combination of fast processors, massive data-storage units, and efficient matrix techniques provide numerical solutions to complex, three-dimensional transport problems. These approaches allow researchers to take advantage of the considerable information content routinely achievable in high-accuracy temperature work.

Blasch, Kyle W.; Constantz, Jim; Stonestrom, David A.

2007-01-01

260

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

USGS Publications Warehouse

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.

Brown, Richmond F.; Signor, Donald C.

1973-01-01

261

Biologically derived melanin electrodes in aqueous sodium-ion energy storage devices  

PubMed Central

Biodegradable electronics represents an attractive and emerging paradigm in medical devices by harnessing simultaneous advantages afforded by electronically active systems and obviating issues with chronic implants. Integrating practical energy sources that are compatible with the envisioned operation of transient devices is an unmet challenge for biodegradable electronics. Although high-performance energy storage systems offer a feasible solution, toxic materials and electrolytes present regulatory hurdles for use in temporary medical devices. Aqueous sodium-ion charge storage devices combined with biocompatible electrodes are ideal components to power next-generation biodegradable electronics. Here, we report the use of biologically derived organic electrodes composed of melanin pigments for use in energy storage devices. Melanins of natural (derived from Sepia officinalis) and synthetic origin are evaluated as anode materials in aqueous sodium-ion storage devices. Na+-loaded melanin anodes exhibit specific capacities of 30.4 1.6 mAhg?1. Full cells composed of natural melanin anodes and ?-MnO2 cathodes exhibit an initial potential of 1.03 0.06 V with a maximum specific capacity of 16.1 0.8 mAhg?1. Natural melanin anodes exhibit higher specific capacities compared with synthetic melanins due to a combination of beneficial chemical, electrical, and physical properties exhibited by the former. Taken together, these results suggest that melanin pigments may serve as a naturally occurring biologically derived charge storage material to power certain types of medical devices. PMID:24324163

Kim, Young Jo; Wu, Wei; Chun, Sang-Eun; Whitacre, Jay F.; Bettinger, Christopher J.

2013-01-01

262

Biologically derived melanin electrodes in aqueous sodium-ion energy storage devices.  

PubMed

Biodegradable electronics represents an attractive and emerging paradigm in medical devices by harnessing simultaneous advantages afforded by electronically active systems and obviating issues with chronic implants. Integrating practical energy sources that are compatible with the envisioned operation of transient devices is an unmet challenge for biodegradable electronics. Although high-performance energy storage systems offer a feasible solution, toxic materials and electrolytes present regulatory hurdles for use in temporary medical devices. Aqueous sodium-ion charge storage devices combined with biocompatible electrodes are ideal components to power next-generation biodegradable electronics. Here, we report the use of biologically derived organic electrodes composed of melanin pigments for use in energy storage devices. Melanins of natural (derived from Sepia officinalis) and synthetic origin are evaluated as anode materials in aqueous sodium-ion storage devices. Na(+)-loaded melanin anodes exhibit specific capacities of 30.4 1.6 mAhg(-1). Full cells composed of natural melanin anodes and ?-MnO2 cathodes exhibit an initial potential of 1.03 0.06 V with a maximum specific capacity of 16.1 0.8 mAhg(-1). Natural melanin anodes exhibit higher specific capacities compared with synthetic melanins due to a combination of beneficial chemical, electrical, and physical properties exhibited by the former. Taken together, these results suggest that melanin pigments may serve as a naturally occurring biologically derived charge storage material to power certain types of medical devices. PMID:24324163

Kim, Young Jo; Wu, Wei; Chun, Sang-Eun; Whitacre, Jay F; Bettinger, Christopher J

2013-12-24

263

Fate of human viruses in groundwater recharge systems  

SciTech Connect

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.

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

1980-03-01

264

Groundwater recharge from Long Lake, Indiana Dunes National Lakeshore  

SciTech Connect

Long Lake, located between Lake Michigan and the Dune-complexes of Indiana Dunes, was formed during Pleistocene and Holocene epochs. The lake is currently being studied to understand the detailed hydrology. One of the objective of the study is to understand the hydrologic relationship between the lake and a water treatment holding pond to the northeast. Understanding the water movement between the two bodies of water, if any, would be very important in the management and protection of nature preserves in the area. Seepage measurement and minipiezometric tests indicate groundwater recharge from Long Lake. The groundwater recharge rate is approximately 1.40 to 22.28 x 10[sup [minus]4] m/day. An estimate of the amount of recharge of 7.0 x 10[sup 6] m[sup 3]/y may be significant in terms of groundwater recharge of the upper aquifer system of the Dunes area. The water chemistry of the two bodies of water appears to be similar, however, the pH of the holding pond is slightly alkaline (8.5) while that of Long Lake is less alkaline (7.7). There appears to be no direct contact between the two bodies of water (separated by approximately six meters of clay rich sediment). The geology of the area indicates a surficial aquifer underlying Long Lake. The lake should be regarded as a recharge area and should be protected from pollutants as the degradation of the lake would contaminate the underlying aquifer.

Isiorho, S.A.; Beeching, F.M. (Indiana Univ., Fort Wayne, IN (United States). Geosciences Dept.); Whitman, R.L.; Stewart, P.M. (National Park Services, Porter, IN (United States). Indiana Dunes National Lakeshore); Gentleman, M.A.

1992-01-01

265

78 FR 76731 - Special Conditions: Boeing Model 777-200, -300, and -300ER Series Airplanes; Rechargeable Lithium...  

Federal Register 2010, 2011, 2012, 2013

...Series Airplanes; Rechargeable Lithium Ion Batteries and Battery Systems AGENCY: Federal...the installation of rechargeable lithium ion batteries and battery system that will be...equipment that uses rechargeable lithium ion batteries and battery systems in the...

2013-12-19

266

78 FR 52107 - Special Conditions: Boeing Model 777-200, -300, and -300ER Series Airplanes; Rechargeable Lithium...  

Federal Register 2010, 2011, 2012, 2013

...Series Airplanes; Rechargeable Lithium Ion Batteries and Battery Systems AGENCY: Federal...specifically the rechargeable lithium ion batteries and battery system that will be...equipment that uses rechargeable lithium ion batteries and battery systems in the...

2013-08-22

267

The development and challenges of rechargeable non-aqueous lithiumair batteries  

Microsoft Academic Search

Lithiumair (Liair) batteries have recently received much attention due to their extremely high theoretical energy densities. The significantly larger theoretical energy density of Liair batteries is due to the use of a pure lithium metal anode and the fact that the cathode oxidant, oxygen, is stored externally since it can be readily obtained from the surrounding air. However, before Liair

Lei-Lei Zhang; Zhong-Li Wang; Dan Xu; Xin-Bo Zhang; Li-Min Wang

2012-01-01

268

Understanding the role of manganese dioxide in the oxidation of phenolic compounds by aqueous permanganate.  

PubMed

Recent studies have shown that manganese dioxide (MnO2) can significantly accelerate the oxidation kinetics of phenolic compounds such as triclosan and chlorophenols by potassium permanganate (Mn(VII)) in slightly acidic solutions. However, the role of MnO2 (i.e., as an oxidant vs catalyst) is still unclear. In this work, it was demonstrated that Mn(VII) oxidized triclosan (i.e., trichloro-2-phenoxyphenol) and its analogue 2-phenoxyphenol, mainly generating ether bond cleavage products (i.e., 2,4-dichlorophenol and phenol, respectively), while MnO2 reacted with them producing appreciable dimers as well as hydroxylated and quinone-like products. Using these two phenoxyphenols as mechanistic probes, it was interestingly found that MnO2 formed in situ or prepared ex situ greatly accelerated the kinetics but negligibly affected the pathways of their oxidation by Mn(VII) at acidic pH 5. The yields (R) of indicative products 2,4-dichlorophenol and phenol from their respective probes (i.e., molar ratios of product formed to probe lost) under various experimental conditions were quantified. Comparable R values were obtained during the treatment by Mn(VII) in the absence vs presence of MnO2. Meanwhile, it was confirmed that MnO2 could accelerate the kinetics of Mn(VII) oxidation of refractory nitrophenols (i.e., 2-nitrophenol and 4-nitrophenol), which otherwise showed negligible reactivity toward Mn(VII) and MnO2 individually, and the effect of MnO2 was strongly dependent upon its concentration as well as solution pH. These results clearly rule out the role of MnO2 as a mild co-oxidant and suggest a potential catalytic effect on Mn(VII) oxidation of phenolic compounds regardless of their susceptibility to oxidation by MnO2. PMID:25437924

Jiang, Jin; Gao, Yuan; Pang, Su-Yan; Lu, Xue-Ting; Zhou, Yang; Ma, Jun; Wang, Qiang

2015-01-01

269

Hydrogeology of Regional Valley Fill Aquifers with Mountain System Recharge  

NASA Astrophysics Data System (ADS)

Groundwater in the North Okanagan was investigated using an integrated physical, geochemical and numerical approach. The North Okanagan Groundwater Characterization and Assessment (NOGWCA) project began with an investigation of the geology and hydrostratigraphy of the North Okanagan region. The Deep Creek and Fortune Creek watersheds were found to contain multiple valley-fill aquifers which are recharged via mountain system recharge (MSR) and direct recharge to unconfined aquifers in the valley bottom. Detailed hydrometric data indicates groundwater recharge within the alluvial fan of Fortune Creek, and discharge to surface water in the lower reaches of Deep Creek. Valley side recharge from the adjacent mountains generates artesian conditions in the valley center. Physical hydrogeological measurements and groundwater and surface water geochemistry were used to determine the overall groundwater flow regime, inter-aquifer exchange and surface-water groundwater interactions. Conservative elements and deuterium/oxygen isotopes were used in a mixing cell model (MCM) approach to assess groundwater flow between aquifers. Efforts to accurately quantify and understand MSR are hampered by sparse data on the geochemical character of bedrock aquifers. Watershed scale recharge estimates and water balances were derived from a regional integrated climate dataset coupled to FEFLOW simulations. The first stage modeled steady state conditions within the main valley center aquifer. Integrated surface water and groundwater modeling is to be carried out in the future. The groundwater flow modeling will contribute to subsequent water management decisions at the watershed scale. Climate change and economic change scenarios will be considered in the integrated surface water and groundwater modeling.

Ping, J.; Nichol, C.; Wei, A.

2009-05-01

270

Rechargeable room-temperature CF(x)-sodium battery.  

PubMed

Here we demonstrate for the first time that CFx cathodes show rechargeable capability in sodium ion batteries with an initial discharge capacity of 1061 mAh g(-1) and a reversible discharge capacity of 786 mAh g(-1). The highly reversible electrochemical reactivity of CFx with Na at room temperature indicates that the decomposition of NaF could be driven by carbon formed during the first discharge. The high reversible capacity made it become a promising cathode material for future rechargeable sodium batteries. PMID:24494989

Liu, Wen; Li, Hong; Xie, Jing-Ying; Fu, Zheng-Wen

2014-02-26

271

Thin Rechargeable Batteries for CMOS SRAM Memory Protection  

NASA Technical Reports Server (NTRS)

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.

Crouse, Dennis N.

1993-01-01

272

Focused Ground-Water Recharge in the Amargosa Desert Basin  

USGS Publications Warehouse

The Amargosa River is an approximately 300-kilometer long regional drainage connecting the northern highlands on the Nevada Test Site in Nye County, Nev., to the floor of Death Valley in Inyo County, Calif. Streamflow analysis indicates that the Amargosa Desert portion of the river is dry more than 98 percent of the time. Infiltration losses during ephemeral flows of the Amargosa River and Fortymile Wash provide the main sources of ground-water recharge on the desert-basin floor. The primary use of ground water is for irrigated agriculture. The current study examined ground-water recharge from ephemeral flows in the Amargosa River by using streamflow data and environmental tracers. The USGS streamflow-gaging station at Beatty, Nev., provided high-frequency data on base flow and storm runoff entering the basin during water years 1998?2001. Discharge into the basin during the four-year period totaled 3.03 million cubic meters, three quarters of which was base flow. Streambed temperature anomalies indicated the distribution of ephemeral flows and infiltration losses within the basin. Major storms that produced regional flow during the four-year period occurred in February 1998, during a strong El Ni?o that more than doubled annual precipitation, and in July 1999. The study also quantified recharge beneath undisturbed native vegetation and irrigation return flow beneath irrigated fields. Vertical profiles of water potential and environmental tracers in the unsaturated zone provided estimates of recharge beneath the river channel (0.04?0.09 meter per year) and irrigated fields (0.1?0.5 meter per year). Chloride mass-balance estimates indicate that 12?15 percent of channel infiltration becomes ground-water recharge, together with 9?22 percent of infiltrated irrigation. Profiles of potential and chloride beneath the dominant desert-shrub vegetation suggest that ground-water recharge has been negligible throughout most of the basin since at least the early Holocene. Surface-based electrical-resistivity imaging provided areal extension of borehole information from sampled profiles. These images indicate narrowly focused recharge beneath the Amargosa River channel, flanked by large tracts of recharge-free basin floor.

Stonestrom, David A.; Prudic, David E.; Walvoord, Michelle A.; Abraham, Jared D.; Stewart-Deaker, Amy E.; Glancy, Patrick A.; Constantz, Jim; Laczniak, Randell J.; Andraski, Brian J.

2007-01-01

273

78 FR 76772 - Special Conditions: Airbus Model A350-900 Airplanes; Permanently Installed Rechargeable Lithium...  

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...Permanently Installed Rechargeable Lithium-Ion Batteries and Battery Systems AGENCY: Federal...permanently installed rechargeable lithium-ion batteries and battery systems. These batteries...did not anticipate the use of lithium-ion batteries and battery systems on...

2013-12-19

274

78 FR 55773 - Fourteenth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems...  

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...Rechargeable Lithium Battery and Battery Systems--Small and Medium Size...Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size...from last Plenary meeting. Li-ion Current Events. Status of...

2013-09-11

275

78 FR 38093 - Thirteenth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems...  

Federal Register 2010, 2011, 2012, 2013

...Rechargeable Lithium Battery and Battery Systems--Small and Medium Size...Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size...and discussion of next steps. Li-ion Current Events. Working...

2013-06-25

276

Self-doped block copolymer electrolytes for solid-state, rechargeable lithium batteries  

E-print Network

Self-doped block copolymer electrolytes for solid-state, rechargeable lithium batteries Donald R and cathode binder thin-®lm, solid-state, rechargeable lithium batteries of the type Li/ BCE/LiMnO2 have been to be addressed to meet the demanding requirements of a commercially viable solid- state rechargeable battery

Sadoway, Donald Robert

277

A Wireless Power Interface for Rechargeable Battery Operated Neural Recording Implants  

E-print Network

A Wireless Power Interface for Rechargeable Battery Operated Neural Recording Implants Pengfei Li a biocompatible rechargeable battery. As battery technology continues to advance toward higher volumetric for a low power elec- tronic interface capable of supporting a rechargeable battery implant framework

Slatton, Clint

278

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

E-print Network

such as a solar panel or a furl cell, and a rechargeable energy storage such as a battery or a super- capacitor with a rechargeable battery. In this model, all task periods are identical, all task deadlines are equal to the common that the wasted recharging energy is minimized and the battery level is at all times within two limits, starting

Paris-Sud XI, Université de

279

Ground-Water Recharge Through Active Sand Dunes in Northwestern Nevada  

Microsoft Academic Search

Most water-resouree investigations in semiarid basins of the Great Basin in western North America conclude that groundwater recharge from direct precipitation on the valley floor is negligible. However, many of these basins contain large areas covered by unvegetated, active sand dunes that may act as conduits for ground-water recharge. The potential for this previously undocumented recharge was investigated in an

David L. Berger

1992-01-01

280

Climate change impacts on groundwater recharge uncertainty, shortcomings, and the way forward?  

Microsoft Academic Search

An integrated approach to assessing the regional impacts of climate and socio-economic change on groundwater recharge is described from East Anglia, UK. Many factors affect future groundwater recharge including changed precipitation and temperature regimes, coastal flooding, urbanization, woodland establishment, and changes in cropping and rotations. Important sources of uncertainty and shortcomings in recharge estimation are discussed in the light of

I. P. Holman

2006-01-01

281

Climate change impacts on groundwater recharge uncertainty, shortcomings, and the way forward?  

Microsoft Academic Search

An integrated approach to assessing the regional impacts of climate and socio-economic change on groundwater recharge is described from East Anglia, UK. Many factors affect future groundwater recharge including changed precipitation and temperature regimes, coastal flooding, urbanization, woodland establishment, and changes in cropping and rotations.Important sources of uncertainty and shortcomings in recharge estimation are discussed in the light of the

I. P. Holman

2006-01-01

282

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

Microsoft Academic Search

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

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

2010-01-01

283

A dimensionless number describing the effects of recharge and geometry on discharge from simple karstic aquifers  

Microsoft Academic Search

The responses of karstic aquifers to storms are often used to obtain information about aquifer geometry. In general, spring hydrographs are a function of both system geometry and recharge. However, the majority of prior work on storm pulses through karst has not studied the effect of recharge on spring hydrographs. To examine the relative importance of geometry and recharge, we

M. D. Covington; C. M. Wicks; M. O. Saar

2009-01-01

284

Maintaining Sensor Networks Perpetually Via Wireless Recharging Mobile Vehicles  

E-print Network

Maintaining Sensor Networks Perpetually Via Wireless Recharging Mobile Vehicles Weifa Liang resonant coupling is a promising technology for wireless sensor networks as it can provide a controllable mobile vehicles to charge sensors in a sensor network so that none of the sensors runs out of its energy

Liang, Weifa

285

PRINCIPALS OF ORGANIC CONTAMINANT BEHAVIOR DURING ARTIFICIAL RECHARGE  

EPA Science Inventory

The behavior of a variety of organic contaminants having low molecular weight has been observed during groundwater recharge with reclaimed water. The evidence is site-specific, but is believed to have broader implications regarding the general behavior of organic contaminants in ...

286

Oxygen electrodes for rechargeable alkaline fuel cells, 3  

NASA Technical Reports Server (NTRS)

The investigation and development of electrocatalysts and supports for the positive electrode of moderate temperature single unit rechargeable alkaline fuel cells is described. Focus is on chemical and electrochemical stability and O2 reduction/evolution activity of the electrode in question.

Swette, L.; Kackley, N.; Mccatty, S. A.

1991-01-01

287

Oxygen electrodes for rechargeable alkaline fuel cells-II  

NASA Technical Reports Server (NTRS)

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.

Swette, L.; Kackley, N.

1989-01-01

288

Oxygen electrodes for rechargeable alkaline fuel cells. II  

NASA Technical Reports Server (NTRS)

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.

Swette, L.; Kackley, N.

1990-01-01

289

Climate Change Effects on Yucca Mountain Region Groundwater Recharge  

Microsoft Academic Search

Groundwater geochemical data from 211 sampling locations in the Amargosa Desert region are analyzed to better understand the general flow system and climate-induced changes in recharge around Fortymile Wash near Yucca Mountain. Major ion groundwater chemistry was examined using the multivariate statistical methods of principal component analysis and k-means cluster analysis. These analyses showed several groundwater signatures, or potential flowpaths;

Arturo Woocay; John C. Walton

2006-01-01

290

A fuzzy logic model for estimation of groundwater recharge  

Microsoft Academic Search

Water budget models are commonly accepted methods for estimating the groundwater recharge. Some of the inputs to these models such as soil-moisture deficit, actual evapotranspiration, direct runoff etc, are difficult to measure. The space dynamic nature of these parameters makes their quantification even more difficult. The error in estimation increases significantly during extreme events. In addition, it has been found

A. K. Awasthi; O. P. Dubey; S. Sharma

2005-01-01

291

Methods Note/ Net Recharge vs. Depth to Groundwater  

E-print Network

Methods Note/ Net Recharge vs. Depth to Groundwater Relationship in the Platte River Valley rates were correlated with depth to groundwater (d) values in the wide alluvial valley of the Platte soils with a shallow groundwater table. The transition depth (dt) between negative and positive values

Szilagyi, Jozsef

292

A Wireless Power Interface for Rechargeable Battery Operated Medical Implants  

Microsoft Academic Search

This brief presents a highly integrated wirelessly powered battery charging circuit for miniature lithium (Li)-ion rechargeable batteries used in medical implant applications. An inductive link and integrated Schottky barrier rectifying diodes are used to extract the DC signal from a power carrier while providing low forward voltage drop for improved efficiency. The battery charger employs a new control loop that

Pengfei Li; Rizwan Bashirullah

2007-01-01

293

A polymer electrolyte-based rechargeable lithium\\/oxygen battery  

Microsoft Academic Search

A novel rechargeable Li\\/O battery is reported. It comprises a Li{sup +} conductive organic polymer electrolyte membrane sandwiched by a thin Li metal foil anode, and a thin carbon composite electrode on which oxygen, the electroactive cathode material, accessed from the environment, is reduced during discharge to generate electric power. It features an all solid state design in which electrode

K. M. Abraham; Z. Jiang

1996-01-01

294

Recent developments and likely advances in lithium rechargeable batteries  

Microsoft Academic Search

Developments in lithium rechargeable batteries since the last International Power Sources Symposium in Manchester in 2001 are described. The major developments are that, as expected, lithium cobalt oxide cathode material is being replaced by lithium cobalt\\/nickel oxide and polymer electrolyte batteries are now coming into production. Likely future developments are new cathode and electrolyte materials to reduce cost and to

A. G. Ritchie

2004-01-01

295

Carbon materials for lithium-ion rechargeable batteries  

Microsoft Academic Search

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

S. Flandrois; B. Simon

1999-01-01

296

24. APPERATUS FOR RECHARGING MINERS' HEADLAMPS, LOCATED AGAINST THE NORTH ...  

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

24. APPERATUS FOR RECHARGING MINERS' HEADLAMPS, LOCATED AGAINST THE NORTH WALL OF THE LOWER LEVEL OF THE CHIPPY HOIST HOUSE, LOOKING NORTHWEST. SOME OF THE BATTERY PACKS ARE STILL IN PLACE, AND ONE HAS A LAMP HANGING AT THE END - Butte Mineyards, Anselmo Mine, Butte, Silver Bow County, MT

297

Rechargeable batteries: advances since 1977. [Collection of US patents  

Microsoft Academic Search

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

1980-01-01

298

Secure recharge of disposable RFID tickets Riccardo Focardi1  

E-print Network

, so to avoid the card cloning or the restoring some already used resources. In summary, (i) we give Ultralight cards in detail, and we present a new secure method for the recharge of these RFID disposable but yet realistic semantics of these cards, and we also define a simple imperative language suitable

Focardi, Riccardo

299

Moderate temperature rechargeable NaNiS2 cells  

NASA Technical Reports Server (NTRS)

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.

Abraham, K. M.

1983-01-01

300

Aquifer storage and recharge: Innovation in water resources management  

Microsoft Academic Search

Stormwater and treated sewerage effluent, previously regarded as waste, are now being reused in South Australia through the innovative aquifer storage and recharge technique. After pretreatment in wetlands, this water is stored in otherwise unused brackish aquifers for summer irrigation of parklands. Trials are underway using recycled water from the Bolivar Wastewater Treatment Plant for irrigation of market gardens. This

S. R. Barnett; S. R. Howles; R. R. Martin; N. Z. Gerges

2000-01-01

301

Investigation of Possible Extra ~Recharge During Pumping in Nottinghant .Aquifer  

E-print Network

completely from aquifer storage. The value may approach zero if it is estimated based on the draw- downInvestigation of Possible Extra ~Recharge During Pumping in Nottinghant .Aquifer by Jiu J. Jiaoa by analyzing the pumping test data from the Nottingham aquifer, UK. The pumping lasted more than 200 days

Jiao, Jiu Jimmy

302

Cycle-life sensor for rechargeable lithium batteries. Phase 1  

Microsoft Academic Search

The research addressed the problem of characterizing the state of a rechargeable Li battery as a function of cycle life history. Because all Li batteries are hermetically sealed, researchers chose to evaluate the amount and distribution of Li-electrolyte degradation products in situ by the application of electroanalytical techniques at microelectrodes imbedded in the cell package. Good correlations between Li stripping

Koch

1988-01-01

303

Technology uses micro-windmills to recharge cell phones  

E-print Network

was quite surprised with the micro-windmill idea when we showed the demo video of working devices," Rao saidTechnology uses micro-windmills to recharge cell phones A micro-windmill is pictured on the face designed a micro-windmill that generates wind energy and may become an innovative solution to cell phone

Chiao, Jung-Chih

304

Issue and challenges facing rechargeable thin film lithium batteries  

Microsoft Academic Search

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

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

2008-01-01

305

WASTEWATER CONTAMINATE REMOVAL FOR GROUNDWATER RECHARGE AT WATER FACTORY 21  

EPA Science Inventory

This is the second report in a series which describes the performance of Water Factory 21, a 0.66 cu m/s advanced wastewater treatment plant designed to reclaim secondary effluent from a municipal wastewater treatment plant so that it can be used for injection and recharge of a g...

306

Computational uncertainty analysis of groundwater recharge in catchment  

Microsoft Academic Search

In this paper, a computational environinformatics (environmental informatics) operation for mapping the groundwater climatological recharge in regional sub-basin is presented. It is based on a soilwater balance (SWB) and spatial statistics integrated in a GIS environment. Mediterranean is a region with large demands for groundwater supplies. However, water catchment data are affected by large uncertainty, arising from sampling and modelling,

Nazzareno Diodato; Michele Ceccarelli

2006-01-01

307

Climate change effects on vegetation characteristics and groundwater recharge  

NASA Astrophysics Data System (ADS)

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.

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

2010-12-01

308

Climate change effects on vegetation characteristics and groundwater recharge  

NASA Astrophysics Data System (ADS)

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.

(Flip) Witte, J. P. M.; (Ruud) Bartholomeus, R. P.; (Gijsbert) Cirkel, D. G.

2010-05-01

309

Groundwater suitability recharge zones modelling - A GIS application  

NASA Astrophysics Data System (ADS)

Groundwater quality in Gujarat state is highly variable and due to multiplicity of factors viz. influenced by direct sea water encroachment, inherent sediment salinity, water logging, overexploitation leading to overall deterioration in ground water quality, coupled with domestic and industrial pollution etc. The groundwater scenario in the state is not very encouraging due to imbalance between recharge and groundwater exploitation. Further, the demand for water has increased manifold owing to agricultural, industrial and domestic requirement and this has led to water scarcity in many parts of the state, which is likely to become more severe in coming future due to both natural and manmade factors. Therefore, sustainable development of groundwater resource requires precise quantitative assessment based on reasonably valid scientific principles. Hence, delineation of groundwater potential zones (GWPZ), has acquired great significance. The present study focuses on the integrated Geospatial and Multi-Criteria Decision Making (MCDM) techniques to determine the most important contributing factors that affect the groundwater resources and also to delineate the potential zones for groundwater recharge. The multiple thematic layers of influencing parameters viz. geology, geomorphology, soil, slope, drainage density and land use, weightages were assigned to the each factor according to their relative importance as per subject experts opinion owing to the natural setup of the region. The Analytical Hierarchy Process (AHP) was applied to these factors and potential recharge zones were identified. The study area for the assessment of groundwater recharge potential zones is Mahi-Narmada inter-stream region of Gujarat state. The study shows that around 28 % region has the excellent suitability of the ground water recharge.

Dabral, S.; Bhatt, B.; Joshi, J. P.; Sharma, N.

2014-11-01

310

Enhanced recharge and karst, Edwards aquifer, south central Texas  

SciTech Connect

Enhanced recharge is a water management strategy which can add significant quantities of ground water to the available water resources of the San Antonio region by utilizing the immense storage capacity of the unconfined zone of the Edwards aquifer. The Edwards aquifer presently is the sole source of water for a population of over 1,200,000, meeting public supply, industrial, and irrigation demands over a wide area of south central Texas. Valdina Farms Sinkhole is located adjacent to Seco Creek in Medina County and is in the recharge zone of the aquifer. Initial studies indicated that the sinkholes was capable of taking flood flows from Seco Creek and functioning as a recharge structure. Stream channels in the cavern system associated with Valdina Farms Sinkhole were incised into cave deposits and flood debris was present in the caverns at some distance from the sinkhole. Chemical analyses of samples of water from the cave and from nearby wells showed nitrate concentrations that decreased with distance from the cavern. Gradient of the potentiometric surface in the vicinity of the cave was very low, indicating high values of hydraulic conductivity for the aquifer. Based on evidence from these field studies a dam was constructed in 1982 on Seco Creek and a flood diversion channel was excavated to the sinkhole. Reservoir capacity is 2 acre-feet and design recharge rate is 3.8-6.7 m[sup 3]/sec. Annual recharge at the sinkhole has varied from 0 during periods of low runoff to 12,915 acre-feet.

Hammond, W.W. Jr. (Univ. of Texas, San Antonio, TX (United States). Center for Water Research)

1993-02-01

311

Classification of ground-water recharge potential in three parts of Santa Cruz County, California  

USGS Publications Warehouse

Ground-water recharge potential was classified in the Santa Cruz coastal area, North-central area, and Soquel-Aptos area in Santa Cruz County, Calif., for three data elements that affect recharge; slope, soils, and geology. Separate numerical maps for each element were composited into a single numerical map using a classification system that ranked the numbers into areas of good , fair, and poor recharge potential. Most of the Santa Cruz coastal area and the Norht-central area have a poor recharge potential, and much of the Soquel-Aptos area has a good to fair recharge potential. (Kosco-USGS)

Muir, K.S.; Johnson, Michael J.

1979-01-01

312

Transient,spatially-varied recharge for groundwater modeling  

NASA Astrophysics Data System (ADS)

This study is aimed at producing spatially and temporally varying groundwater recharge for transient groundwater modeling in a pilot watershed in the North Okanagan, Canada. The recharge modeling is undertaken by using a Richard's equation based finite element code (HYDRUS-1D) [Simunek et al., 2002], ArcGISTM [ESRI, 2011], ROSETTA [Schaap et al., 2001], in situ observations of soil temperature and soil moisture and a long term gridded climate data [Nielsen et al., 2010]. The public version of HYDUS-1D [Simunek et al., 2002] and another beta version with a detailed freezing and thawing module [Hansson et al., 2004] are first used to simulate soil temperature, snow pack and soil moisture over a one year experimental period. Statistical analysis of the results show both versions of HYDRUS-1D reproduce observed variables to the same degree. Correlation coefficients for soil temperature simulation were estimated at 0.9 and 0.8, at depths of 10 cm and 50 cm respectively; and for soil moisture, 0.8 and 0.6 at 10 cm and 50 cm respectively. This and other standard measures of model performance (root mean square error and average error) showed a promising performance of the HYDRUS-1D code in our pilot watershed. After evaluating model performance using field data and ROSETTA derived soil hydraulic parameters, the HYDRUS-1D code is coupled with ArcGISTM to produce spatially and temporally varying recharge maps throughout the Deep Creek watershed. Temporal and spatial analysis of 25 years daily recharge results at various representative points across the study watershed reveal significant temporal and spatial variations; average recharge estimated at 77.8 50.8mm /year. This significant variation over the years, caused by antecedent soil moisture condition and climatic condition, illustrates the common flaw of assigning a constant percentage of precipitation throughout the simulation period. Groundwater recharge modeling has previously been attempted in the Okanagan Basin and other parts of Canada by using the HELP code. However, HELP has known limitations related with boundary conditions as well as spatial and temporal discretization options, and thus cannot simulate highly variable fluxes near boundaries. The limitations are even more pronounced in semi-arid areas like the Okanagan Basin where upward fluxes can be high, because HELP assumes that water below evaporative zone simply drains to the base of a soil column without accounting for upward fluxes. In addition to these limitations, previous studies that used HELP for recharge estimation, [Towes and Allen, 2009; Jyrkama and Sykes, 2007], did not attempt to verify model performance in their study area. The study here presents an integrated procedure that can help address some of these often neglected modelling challenges. The significance of the method in transient groundwater modeling is demonstrated by applying the spatially and temporally varying recharge boundary condition to a saturated zone groundwater model, MIKESHE [DHI, 2009a]. The water table simulated using this method is found to be within 0.6 m of the observed values, whereas the water levels estimated using uniform recharge boundary condition can fluctuate by as much as 1.6 m. Root mean square errors were estimated at 0.3 and 0.94 respectively.

Assefa, Kibreab; Woodbury, Allan

2013-04-01

313

Monitoring induced denitrification in an artificial aquifer recharge system.  

NASA Astrophysics Data System (ADS)

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 Vicen 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.

Grau-Martinez, Alba; Torrent, Clara; Folch, Albert; Domnech, Cristina; Otero, Neus; Soler, Albert

2014-05-01

314

Zinc electrode and rechargeable zinc-air battery  

DOEpatents

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.

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

1989-01-01

315

Recharging the Silicon Crucible in a Hot Furnace  

NASA Technical Reports Server (NTRS)

"Melt recharger" adds raw silicon to crucible in crystal-growing furnace without disturbing inert-gas atmosphere or significantly lowering temperature of melt. Crucible-refill hopper is lowered into hot zone of crystal-pulling chamber through an isolation valve. Cable that supports hopper is fastened to cone-shaped stopper in bottom of hopper. Stopper moves out of opening in hopper, allowing part of polysilicon charge to drop into crucible.

Lane, R. L.

1982-01-01

316

Changes in vegetation diversity caused by artificial recharge  

USGS Publications Warehouse

Efforst to increase the rate of artificial recharge through basins often necessitates scrapping and ditching before and during operations. Such operations can result in more or less drastic changes in vegetation (depending on what was there before), characterized by diminisched numbers of species and lowered diversity. Two examples, one from Texas and one from the Netherlands are presented showing how similar treatments cause similar changes in two completely difference plant communities. ?? 1979 Dr. W. Junk b.v. - Publishers.

Van Hylckama, T. E. A.

1979-01-01

317

Molten Air -- A new, highest energy class of rechargeable batteries  

E-print Network

This study introduces the principles of a new class of batteries, rechargeable molten air batteries, and several battery chemistry examples are demonstrated. The new battery class uses a molten electrolyte, are quasi reversible, and have amongst the highest intrinsic battery electric energy storage capacities. Three examples of the new batteries are demonstrated. These are the iron, carbon and VB2 molten air batteries with respective intrinsic volumetric energy capacities of 10,000, 19,000 and 27,000 Wh per liter.

Licht, Stuart

2013-01-01

318

Computer simulations of the impedance response of lithium rechargeable batteries  

Microsoft Academic Search

A mathematical model is developed to simulate the impedance response of a wide range of lithium rechargeable battery systems. The mathematical model is a macroscopic model of a full-cell sandwich utilizing porous electrode theory to treat the electrode region and concentrated solution theory for transport processes in solution. Insertion processes are described with charge-transfer kinetic expressions and solid-phase diffusion of

Marc Doyle; Jeremy P. Meyers; John Newman

2000-01-01

319

NiF2 Cathodes For Rechargeable Na Batteries  

NASA Technical Reports Server (NTRS)

Use of NiF2 cathodes in medium-to-high-temperature rechargeable sodium batteries increases energy and power densities by 25 to 30 percent without detracting from potential advantage of safety this type of sodium battery offers over sodium batteries having sulfur cathodes. High-energy-density sodium batteries with metal fluoride cathodes used in electric vehicles and for leveling loads on powerlines.

Bugga, Ratnakumar V.; Distefano, Salvador; Halpert, Gerald

1992-01-01

320

An implantable power supply with an optically rechargeable lithium battery  

Microsoft Academic Search

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. The authors have shown that, for a photodiode area of 2.1 cm 2, 17

Kazuya Goto; Tetsuya Nakagawa; Osamu Nakamura; Satoshi Kawata

2001-01-01

321

A polyaniline and Nafion composite film as a rechargeable battery  

Microsoft Academic Search

The charge-discharge characteristics of polyaniline (PAn)-Nafion-PAn composite films used as rechargeable batteries were investigated. The batteries were formed chemically by sandwiching Nafion between two thin layers of PAn-Nafion composite in equilibrium with various electrolytes. It was found that cells with LiClO4 in propylene carbonate as electrolyte showed the highest capacity. The charge and discharge performance of the battery was almost

N. Li; J. Y. Lee; L. H. Ong

1992-01-01

322

A manganese oxyiodide cathode for rechargeable lithium batteries  

Microsoft Academic Search

The increasing demand for portable electronic devices is driving the development of compact lightweight batteries of high energy density. Lithium-ion batteries tend to be the systems of choice, as they offer higher energy densities and longer operational lifetimes than other rechargeable battery systems,. But commercially available lithium-ion batteries make use of layered LiCoO2 cathodes,, and the high cost and toxicity

Jaekook Kim; Arumugam Manthiram

1997-01-01

323

Focused Recharge in a Semi-arid Riparian Zone  

NASA Astrophysics Data System (ADS)

Precipitation-induced recharge can be an important component of the water balance of semi-arid riparian zones. Recharge mechanisms were assessed as part of an ecohydrologic investigation at a site in a vegetated riparian zone along the Arkansas River in south-central Kansas (Larned Research Site). This site contains a network of shallow wells for water-table monitoring, neutron-probe access tubes for vadose-zone water content observations, a stream-gage station, and a weather station. Over the last four years, the Arkansas River has flowed at the site for less than four months, so the usual state of the channel is a dry, 20-30 m swath of coarse sand and gravel bounded by riparian-zone vegetation. An evaluation of water-table responses to precipitation at wells located at different distances from the channel found that recharge appears to be primarily occurring through the channel deposits. In the absence of rainfall, the general trend of ground water flow is from west to east. During and shortly after rain events, however, the hydraulic gradient changes and ground water flows outward from a mound underneath the channel. The peaks in the water-table hydrographs produced by precipitation events are lagged and attenuated with distance from the river channel in a manner very similar to what is observed when a flow event occurs in the river channel. These changes with distance from the channel appear to be independent of the depth to the water table. In addition, vadose-zone water content data show little evidence of vertical flow through the vadose zone in the vegetated riparian area in response to the precipitation. Variations in the dissolved solids content of ground water across the riparian area are consistent with recharge primarily occurring through the channel deposits.

Cook, A.; Geyer, T.; Shook, G.; Butler, J. J.; Whittemore, D.; Kluitenberg, G.

2006-12-01

324

Using artificial recharge to restore groundwater / surface water interactions  

NASA Astrophysics Data System (ADS)

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 year does not provide continuous stream discharge and replenishment of ground water resources. Another option to restore the interaction between ground and surface water consists in using reclaimed urban wastewater to recharge the alluvial aquifers. In that way, overall extractions may be partially balanced by returning used water to the ground. Such a situation has been studied in the Onyar River basin (NE Catalonia, Spain; extension: 295 sq km) where a continuous water table drawdown took place after several years of drought. As a consequence, stream discharge was nil, except on those river reaches were treated urban water was dumped. Because of high nutrient concentrations and salinity of treated water, the environmental quality of the riparian system degraded over time. Therefore, aquifer recharge using infiltration ponds (instead of dumping treated water to the stream) can be considered an appropriate action to rise the water table levels and to improve water quality through soil nutrient elimination. Field and laboratory experiments have been conducted to measure infiltration rates and soil solute reduction capability. Preliminary results show that the alluvial sediments of the Onyar basin may perform adequately if treated water is applied. Furthermore, a mathematical flow model allows to estimate water table levels after infiltration, the mass balance between the alluvial aquifer and the stream, and finally the length of the stream that will benefit from recharge. Acknowledgments: Research funded by joint project Fundacin AGBAR - ICTA (UAB).

Menci, A.; Vilanova, E.; Mas-Pla, J.

2003-04-01

325

Polymer Considerations in Rechargeable Lithium Ion Plastic Batteries  

Microsoft Academic Search

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

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

1995-01-01

326

The MOLICEL(R) rechargeable lithium system: Multicell battery aspects  

NASA Technical Reports Server (NTRS)

MOLICEL rechargeable lithium cells were cycled in batteries using series, parallel, and series/parallel connections. The individual cell voltages and branch currents were measured to understand the cell interactions. The observations were interpreted in terms of the inherent characteristics of the Li/MoS2 system and in terms of a singular cell failure mode. The results confirm that correctly configured multicell batteries using MOLICELs have performance characteristics comparable to those of single cells.

Fouchard, D.; Taylor, J. B.

1987-01-01

327

Estimating recharge at Yucca Mountain, Nevada, USA: Comparison of methods  

USGS Publications Warehouse

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.

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

2002-01-01

328

Estimating recharge at Yucca Mountain, Nevada: A case study  

SciTech Connect

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.

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

2001-05-13

329

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

SciTech Connect

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

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

2001-11-01

330

Electrochemically Stable Cathode Current Collectors for Rechargeable Magnesium Batteries  

SciTech Connect

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.

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

2014-01-01

331

Development of Carbon Anode for Rechargeable Lithium Cells  

NASA Technical Reports Server (NTRS)

Conventionally, rechargeable lithium cells employ a pure lithium anode. To overcome problems associated with the pure lithium electrode, it has been proposed to replace the conventional electrode with an alternative material having a greater stability with respect to the cell electrolytes. For this reason, several graphitic and coke based carbonaceous materials were evaluated as candidate anode materials...In this paper, we summarize the results of the studies on Li-ion cell development.

Huang, C. -K.; Surampudi, S.; Halpert, G.

1994-01-01

332

Performance of Bellcore's plastic rechargeable Li-ion batteries  

Microsoft Academic Search

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

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

1996-01-01

333

Using MODFLOW 2000 to model ET and recharge for shallow ground water problems.  

PubMed

In environments with shallow ground water elevation, small changes in the water table can cause significant variations in recharge and evapotranspiration fluxes. Particularly, where ground water is close to the soil surface, both recharge and evapotranspiration are regulated by a thin unsaturated zone and, for accuracy, must be represented using nonconstant and often nonlinear relationships. The most commonly used ground water flow model today, MODFLOW, was originally designed with a modular structure with independent packages representing recharge and evaporation processes. Systems with shallow ground water, however, may be better represented using either a recharge function that varies with ground water depth or a continuous recharge and evapotranspiration function that is dependent on depth to water table. In situations where the boundaries between recharging and nonrecharging cells change with time, such as near a seepage zone, a continuous ground water flux relationship allows recharge rates to change with depth rather than having to calculate them at each stress period. This research article describes the modification of the MODFLOW 2000 recharge and segmented evapotranspiration packages into a continuous recharge-discharge function that allows ground water flux to be represented as a continuous process, dependent on head. The modifications were then used to model long-term recharge and evapotranspiration processes on a saline, semiarid floodplain in order to understand spatial patterns of salinization, and an overview of this process is given. PMID:18624693

Doble, Rebecca C; Simmons, Craig T; Walker, Glen R

2009-01-01

334

Issue and challenges facing rechargeable thin film lithium batteries  

SciTech Connect

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 are being driven by an ever-increasing demand for portable electronic devices. Lithium batteries are the systems of choice, offering high energy density, flexible, lightweight design and longer lifespan than comparable battery technologies. We present a brief historical review of the development of lithium-based thin film rechargeable batteries highlight ongoing research strategies and discuss the challenges that remain regarding the discovery of nanomaterials as electrolytes and electrodes for lithium batteries also this article describes the possible evolution of lithium technology and evaluates the expected improvements, arising from new materials to cell technology. New active materials under investigation and electrode process improvements may allow an ultimate final energy density of more than 500 Wh/L and 200 Wh/kg, in the next 5-6 years, while maintaining sufficient power densities. A new rechargeable battery technology cannot be foreseen today that surpasses this. This report will provide key performance results for thin film batteries and highlight recent advances in their development.

Patil, Arun; Patil, Vaishali; Shin, Dong Wook; Choi, Ji-Won; Paik, Dong-Soo [Thin Film Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Yoon, Seok-Jin [Thin Film Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of)], E-mail: sjyoon@kist.re.kr

2008-08-04

335

Ions in Aqueous Solution  

NSDL National Science Digital Library

This 11-page PDF document is part of an environmental geochemistry course taught by Dr. David Sherman at the University of Bristol. Topics include the aqueous behavior of ions based on their size and charge, the meaning of activity of ions in aqueous solution, the equilibrium constant, complexation of ions and hydrolysis of cations. Also included are informative illustrations, diagrams and equations.

Sherman, David M.; Bristol, University O.

336

Overview of Ground-Water Recharge Study Sites  

USGS Publications Warehouse

Multiyear studies were done to examine meteorologic and hydrogeologic controls on ephemeral streamflow and focused ground-water recharge at eight sites across the arid and semiarid southwestern United States. Campaigns of intensive data collection were conducted in the Great Basin, Mojave Desert, Sonoran Desert, Rio Grande Rift, and Colorado Plateau physiographic areas. During the study period (1997 to 2002), the southwestern region went from wetter than normal conditions associated with a strong El Ni?o climatic pattern (1997?1998) to drier than normal conditions associated with a La Ni?a climatic pattern marked by unprecedented warmth in the western tropical Pacific and Indian Oceans (1998?2002). The strong El Ni?o conditions roughly doubled precipitation at the Great Basin, Mojave Desert, and Colorado Plateau study sites. Precipitation at all sites trended generally lower, producing moderate- to severe-drought conditions by the end of the study. Streamflow in regional rivers indicated diminishing ground-water recharge conditions, with annual-flow volumes declining to 10?46 percent of their respective long-term averages by 2002. Local streamflows showed higher variability, reflecting smaller scales of integration (in time and space) of the study-site watersheds. By the end of the study, extended periods (9?15 months) of zero or negligible flow were observed at half the sites. Summer monsoonal rains generated the majority of streamflow and associated recharge in the Sonoran Desert sites and the more southerly Rio Grande Rift site, whereas winter storms and spring snowmelt dominated the northern and westernmost sites. Proximity to moisture sources (primarily the Pacific Ocean and Gulf of California) and meteorologic fluctuations, in concert with orography, largely control the generation of focused ground-water recharge from ephemeral streamflow, although other factors (geology, soil, and vegetation) also are important. Watershed area correlated weakly with focused infiltration volumes, the latter providing an upper bound on associated ground-water recharge. Estimates of annual focused infiltration for the research sites ranged from about 105 to 107 cubic meters from contributing areas that ranged from 26 to 2,260 square kilometers.

Constantz, Jim; Adams, Kelsey S.; Stonestrom, David A.

2007-01-01

337

Ground-water recharge through active sand dunes in northwestern Nevada  

USGS Publications Warehouse

Most water-resource investigations in semiarid basins of the Great Basin in western North America conclude that ground-water recharge from direct precipitation on the valley floor is negligible. However, many of these basins contain large areas covered by unvegetated, active sand dunes that may act as conduits for ground-water recharge. The potential for this previously undocumented recharge was investigated in an area covered by sand dunes in Desert Valley, northwestern Nevada, using a deep percolation model. The model uses daily measurements of precipitation and temperature to determine energy and moisture balance, from which estimates of long-term mean annual recharge are made. For the study area, the model calculated a mean annual recharge rate of as much as 1.3 inches per year, or 17 percent of the long-term mean precipitation. Model simulations also indicate that recharge would be virtually zero if the study area were covered by vegetation rather than dunes.

Berger, D.L.

1992-01-01

338

Simulation of ground-water level fluctuations using recharge estimated by field infiltrometer measurements  

USGS Publications Warehouse

An infiltrometer was used at multiple locations at a site in Lee County, Fl. to define the spatial variability in infiltration parameters. Water-level data from a well at this site were collected hourly and used to determine the temporal variability in recharge. These results were used to define recharge in a representative stochastic numerical model of the aquifer. Model results without recharge compare well with existing analytical solutions for spatial head variability. Simulations with representative recharge events indicate that recharge produces a significant to dominant effect on head variability, which creates dispersion of contaminants, and that small-scale spatial and temporal recharge variations are the predominant mechanism causing the head variations.

Swain, E.D.

1997-01-01

339

Novel aqueous dual-channel aluminum-hydrogen peroxide battery  

NASA Astrophysics Data System (ADS)

A dual-channel aluminum hydrogen peroxide battery is introduced with an open-circuit voltage of 1.9 volts, polarization losses of 0.9 mV cm(exp 2) mA(exp -1), and power densities of 1 W/cm(exp 2). Catholyte and anolyte cell compartments are separated by an Ir/Pd modified porous nickel cathode. Separation of catholyte and anolyte chambers prevents hydrogen peroxide poisoning of the aluminum anode. The battery is expressed by aluminum oxidation and aqueous solution phase hydrogen peroxide reduction for an overall battery discharge consisting of 2Al + 3H2O2 + 2OH(-) yields 2AlO2(-) + 4H2O E = 2.3 V. The search for electrical propulsion sources which fit the requirements for electrically powered vehicles has blurred the standard characteristics associated with electrochemical storage systems. Presently, electrochemical systems comprised of mechanically rechargeable primary batteries, secondary batteries, and fuel cells are candidates for electrochemical propulsion sources. While important advances in energy and power density continue for nonaqueous and molten electrolytes, aqueous electrolyte batteries often have an advantage in simplicity, conductivity, cost effectiveness, and environmental impact. Systems coupling aluminum anodes and aqueous electrolytes have been investigated. These systems include: aluminum/silver oxide, aluminum/manganese dioxide, aluminum air, aluminum/hydrogen peroxide aqueous batteries, and the recently introduced aluminum/ferricyanide and aluminum sulfur aqueous batteries. Conventional aqueous systems such as the nickel cadmium and lead-acid batteries are characterized by their relatively low energy densities and adverse environmental impact. Other systems have substantially higher theoretical energy capacities. While aluminum-silver oxide has demonstrated the highest steady-state power density, its high cost is an impediment for widespread utilization for electric propulsion.

Marsh, Catherine; Licht, Stuart

1994-06-01

340

Mountain-block recharge, present and past, in the eastern Espaola Basin, New Mexico, USA  

Microsoft Academic Search

Noble gas recharge temperatures (NGTs) and radiocarbon ages were determined for 43 groundwater samples collected in the eastern\\u000a Espaola Basin, New Mexico (USA), to identify mountain-block recharge in waters <10 thousand years (ka) old and to evaluate\\u000a possible changes in mountain-block recharge over the past ?35ka. For Holocene samples from the southeastern area, NGTs are\\u000a dominantly 24 cooler than the

Andrew H. Manning

2011-01-01

341

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

Microsoft Academic Search

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

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

2010-01-01

342

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

SciTech Connect

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.

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

2009-09-28

343

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

SciTech Connect

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.

Savard, C.S.

1998-10-01

344

Artificial-recharge investigation near Aurora, Nebraska: 2-year progress report  

USGS Publications Warehouse

This report presents the results of the first 2 years of a 4-year investigation of potential for artificial recharge and recharge methods that might be used to mitigate excessive aquifer depletion in Nebraska. A Quaternary sand-and-gravel aquifer near Aurora, Nebr., was recharged by injecting water through a well at a rate of approximately 730 gallons per minute for nearly 6 months. Total recharge was 530 acre-feet. Recharge was intermittent during the first 2 months, but was virtually continuous during the last 4 months. Buildup of the water level in the recharge well was 17 feet. The rate of buildup indicates that the well could have accepted water by gravity flow at more than 3,000 gallons per minute for at least 1 year. The cause of a continuing slow rise in water levels in the recharge well in contrast to nearly stable water levels in observation wells as close as 10 feet from the recharge well is as yet uncertain. The recharge water and the native ground water appeared to be chemically compatible. Infiltration rates from 24-foot-diameter surface impoundments ranged from 0.04 to 0.66 feet per day. The higher rates may have resulted in part from leakage down incompletely sealed holes that were drilled to install monitoring equipment. The investigation, including a report on the entire project, is scheduled for completion by 1980.

Lichtler, William F.; Stannard, David I.; Kouma, Edwin

1979-01-01

345

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

USGS Publications Warehouse

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).

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

2005-01-01

346

Estimation of groundwater recharge in a major sand and gravel aquifer in Ireland using multiple approaches  

NASA Astrophysics Data System (ADS)

Groundwater recharge was investigated in the most extensive sand and gravel aquifer (area of approximately 200 km2) in the Republic of Ireland as part of a wider study seeking to derive recharge estimates using aquifer vulnerability mapping. The proportion of effective rainfall (total rainfall minus actual evapotranspiration) that leads to recharge is known as the recharge coefficient. The recharge investigation involved a variety of approaches, including soil moisture budgeting, well hydrograph analysis, numerical modelling and a catchment water balance. The adoption of multiple techniques provided insights on recharge and also on aquifer properties. Comparison of two soil moisture budgeting approaches (FAO Penman-Monteith with Penman-Grindley) showed how variations in the effective rainfall values from these methods influence groundwater levels simulated in a numerical groundwater model. The catchment water balance estimated the recharge coefficient to be between 81 and 85%, which is considered a reasonable range for this aquifer, where overland flow is rarely observed. The well hydrograph analysis, using a previous estimate of specific yield (0.13), gave recharge coefficients in the range of 40-80%, considered low for this aquifer: a revised specific yield of 0.19 resulted in a more reasonable range of recharge coefficients of between 70 and 100%.

Misstear, B. D. R.; Brown, L.; Johnston, P. M.

2009-05-01

347

Groundwater-recharge estimation in the Ordos Plateau, China: comparison of methods  

Microsoft Academic Search

Groundwater recharge is a key factor in water-balance studies, especially in (semi-)arid areas. In this study, multiple methods\\u000a were used to estimate groundwater recharge in the Ordos Plateau (China), including reference to water-table fluctuation, Darcys\\u000a law and the water budget. The mean annual recharge rates found were: water-table-fluctuation method (46109mm\\/yr); saturated-zone\\u000a Darcian method (1754mm\\/yr); and water-budget method (21109mm\\/yr). Generally, groundwater-recharge

Lihe Yin; Guangcheng Hu; Jinting Huang; Dongguang Wen; Jiaqiu Dong; Xiaoyong Wang; Hongbo Li

348

A generalized estimate of ground-water-recharge rates in the Lower Peninsula of Michigan  

USGS Publications Warehouse

Ground-water recharge rates were estimated by analysis of streamflow, precipitation, and basin-characteristics data. Streamflow data were partitioned into ground-water-discharge and surface-water-runoff components. Regression equations relate ground-water discharge to precipitation at each basin. Basin-characteristics and long-term precipitation data were used to aid in the interpolation of recharge characteristics within gaged and ungaged areas. A multiple regression equation was developed to estimate spatial variation of recharge. The generalized estimate provides a consistent method for approximating recharge rates in the Lower Peninsula of Michigan.

Holtschlag, David J.

1997-01-01

349

Seasonalizing mountain system recharge in semi-arid basins-climate change impacts.  

PubMed

Climate variability and change impact groundwater resources by altering recharge rates. In semi-arid Basin and Range systems, this impact is likely to be most pronounced in mountain system recharge (MSR), a process which constitutes a significant component of recharge in these basins. Despite its importance, the physical processes that control MSR have not been fully investigated because of limited observations and the complexity of recharge processes in mountainous catchments. As a result, empirical equations, that provide a basin-wide estimate of mean annual recharge using mean annual precipitation, are often used to estimate MSR. Here North American Regional Reanalysis data are used to develop seasonal recharge estimates using ratios of seasonal (winter vs. summer) precipitation to seasonal actual or potential evapotranspiration. These seasonal recharge estimates compared favorably to seasonal MSR estimates using the fraction of winter vs. summer recharge determined from isotopic data in the Upper San Pedro River Basin, Arizona. Development of hydrologically based seasonal ratios enhanced seasonal recharge predictions and notably allows evaluation of MSR response to changes in seasonal precipitation and temperature because of climate variability and change using Global Climate Model (GCM) climate projections. Results show that prospective variability in MSR depends on GCM precipitation predictions and on higher temperature. Lower seasonal MSR rates projected for 2050-2099 are associated with decreases in summer precipitation and increases in winter temperature. Uncertainty in seasonal MSR predictions arises from the potential evapotranspiration estimation method, the GCM downscaling technique and the exclusion of snowmelt processes. PMID:22091994

Ajami, Hoori; Meixner, Thomas; Dominguez, Francina; Hogan, James; Maddock, Thomas

2012-01-01

350

Corrosion inhibited aqueous slurries  

SciTech Connect

This invention relates to the use of phospho-compositions, for example phosphates, pyrophosphates, polyphosphates, organophosphates, etc., as corrosion inhibitors in oxygen-containing aqueous systems of particulate matter such as slurries of solids, such as coal, etc.

French, E.; Braga, Th.G.

1985-02-19

351

Electrochemical performance of high specific capacity of lithium-ion cell LiV 3O 8\\/\\/LiMn 2O 4 with LiNO 3 aqueous solution electrolyte  

Microsoft Academic Search

The electrochemical performance of aqueous rechargeable lithium battery (ARLB) with LiV3O8 and LiMn2O4 in saturated LiNO3 electrolyte is studied. The results indicate that these two electrode materials are stable in the aqueous solution and no hydrogen or oxygen produced, moreover, intercalation\\/de-intercalation of lithium ions occurred within the range of electrochemical stability of water. The electrochemical performance tests show that the

Mingshu Zhao; Qingyang Zheng; Fei Wang; Weimin Dai; Xiaoping Song

2011-01-01

352

Reflectance of aqueous solutions  

NASA Technical Reports Server (NTRS)

The optical properties and optical constants of water and aqueous solutions were studied to develop an accurate tabulation of graphical representations of the optical constants through a broad spectrum. Manuscripts of articles are presented concerning extinction coefficients, relative specular reflectance, and temperature effect on the water spectrum. Graphs of absolute reflectance, phase shifts, index of refraction, and extinction coefficients for water, heavy water and aqueous solutions are included.

Querry, M. R.

1972-01-01

353

Artificial recharge through a thick, heterogeneous unsaturated zone  

USGS Publications Warehouse

Thick, heterogeneous unsaturated zones away from large streams in desert areas have not previously been considered suitable for artificial recharge from ponds. To test the potential for recharge in these settings, 1.3 ?? 10 6 m3 of water was infiltrated through a 0.36-ha pond along Oro Grande Wash near Victorville, California, between October 2002 and January 2006. The pond overlies a regional pumping depression 117 m below land surface and is located where thickness and permeability of unsaturated deposits allowed infiltration and saturated alluvial deposits were sufficiently permeable to allow recovery of water. Because large changes in water levels caused by nearby pumping would obscure arrival of water at the water table, downward movement of water was measured using sensors in the unsaturated zone. The downward rate of water movement was initially as high as 6 m/d and decreased with depth to 0.07 m/d; the initial time to reach the water table was 3 years. After the unsaturated zone was wetted, water reached the water table in 1 year. Soluble salts and nitrate moved readily with the infiltrated water, whereas arsenic and chromium were less mobile. Numerical simulations done using the computer program TOUGH2 duplicated the downward rate of water movement, accumulation of water on perched zones, and its arrival at the water table. Assuming 10 ?? 10 6 m3 of recharge annually for 20 years, a regional ground water flow model predicted water level rises of 30 m beneath the ponds, and rises exceeding 3 m in most wells serving the nearby urban area.

Izbicki, J.A.; Flint, A.L.; Stamos, C.L.

2008-01-01

354

RISING beamline (BL28XU) for rechargeable battery analysis  

PubMed Central

The newly installed BL28XU beamline at SPring-8 is dedicated to in situ structural and electronic analysis of rechargeable batteries. It supports the time range (1?ms to 100?s) and spatial range (1?m to 1?mm) needed for battery analysis. Electrochemical apparatus for battery charging and discharging are available in experimental hutches and in a preparation room. Battery analysis can be carried out efficiently and effectively using X-ray diffraction, X-ray absorption fine-structure analysis and hard X-ray photoelectron spectroscopy. Here, the design and performance of the beamline are described, and preliminary results are presented. PMID:24365948

Tanida, H.; Fukuda, K.; Murayama, H.; Orikasa, Y.; Arai, H.; Uchimoto, Y.; Matsubara, E.; Uruga, T.; Takeshita, K.; Takahashi, S.; Sano, M.; Aoyagi, H.; Watanabe, A.; Nariyama, N.; Ohashi, H.; Yumoto, H.; Koyama, T.; Senba, Y.; Takeuchi, T.; Furukawa, Y.; Ohata, T.; Matsushita, T.; Ishizawa, Y.; Kudo, T.; Kimura, H.; Yamazaki, H.; Tanaka, T.; Bizen, T.; Seike, T.; Goto, S.; Ohno, H.; Takata, M.; Kitamura, H.; Ishikawa, T.; Ohta, T.; Ogumi, Z.

2014-01-01

355

Lithiated manganese oxide cathodes for rechargeable lithium batteries  

Microsoft Academic Search

Lithiated manganese oxides LixMnyO2 prepared at the low temperature of 400-450C exhibited significantly different electrochemical properties than the spinel phase, LiMn2O4, formed at 650-850C. The former was nonstoichiometric and yielded a capacity of ~0.7 LiMn2 unit at ~2.8 V in polymer electrolyte-based Li cells. Its excellent rechargeability was demonstrated by more than 100 charge\\/discharge cycles. Spinel Li2Mn4 was formed by

K. M. Abraham; D. M. Pasquariello; T. H. Hguyen; Z. Jiang; D. Peramunage

1996-01-01

356

Chemical lithium extraction from manganese oxides for lithium rechargeable batteries  

Microsoft Academic Search

Chemical lithium extraction has been carried out on the following manganese oxides: the spinel-type compounds LiMn2O4 and Li(4\\/3)Mn(5\\/3)O4, and the rocksalt-related compound Li2MnO3. Lithium can be partially removed chemically from these compounds without destroying the host framework. Some compounds obtained by this method have been tested as cathodic materials in rechargeable lithium cells. Electrochemical results and X-ray diffraction patterns of

F. Lubin; A. Lecerf; M. Broussely; J. Labat

1991-01-01

357

High pressure water electrolysis for space station EMU recharge  

NASA Technical Reports Server (NTRS)

A high pressure oxygen recharge system (HPORS), is being developed for application on board the Space Station. This electrolytic system can provide oxygen at up to 6000 psia without a mechanical compressor. The Hamilton standard HPORS based on a solid polymer electrolyte system is an extension of the much larger and succesful 3000 psia system of the U.S. Navy. Cell modules have been successfully tested under conditions beyond which spacecraft may encounter during launch. The control system with double redundancy and mechanical backups for all electronically controlled components is designed to ensure a safe shutdown.

Lance, Nick; Puskar, Michael; Moulthrop, Lawrence; Zagaja, John

1988-01-01

358

A 65 Ah rechargeable lithium molybdenum disulfide battery  

NASA Technical Reports Server (NTRS)

A rechargeable lithium molybdenum disulfide battery which has a number of superior performance characteristics which includes a high energy density, a high power density, and a long charge retention time was developed. The first cell sizes developed included a C size cell and an AA size cell. Over the last two years, a project to demonstrate the feasibility of the scale up to this technology to a BC size cell with 65 Ah capacity was undertaken. The objective was to develop, build, and test a .6 kWh storage battery consisting of 6 BC cells in series.

Brandt, K.

1986-01-01

359

Improved discharge characteristics of tunnel-containing manganese oxide electrodes for rechargeable lithium battery applications  

SciTech Connect

LixMnO2 made from Na0.44MnO2 has an unusual tunnel structure which allows ion insertion processes to occur with minimal strain. It cycles very reversibly at an average voltage of about 3.2 vs. Li without undergoing phase conversion. The stability of this material makes it a promising candidate for use in electric vehicle applications, which not only have severe cost constraints, but also require long cycle life and abuse-tolerance. In practical lithium cells, however, the demonstrated capacity is typically less than the predicted 200 mAh/g for LixMnO2 cathode materials made by conventional solid-state reactions. This is due to kinetic limitations and to the sloping discharge characteristics. Attritor-milling of conventionally-made LixMnO2 and glycine-nitrate combustion synthesis have been used to produce powders with average particle size below 1 mm, improved rate capability, and a 15 percent improvement in utilization. Up to 55 percent of the Mn in LixMnO2 with the Na0.44MnO2 structure can also be replaced with Ti. Ti-doped analogs have modified discharge characteristics, with some exhibiting better utilization between set voltage limits than the parent compound.

Doeff, Marca M.; Richardson, Thomas J.; Hwang, Kwang-Taek; Anapolsky, Abraham

2000-05-01

360

Using Multiple Natural Tracers to Investigate Groundwater Recharge and Flow in Mountains  

NASA Astrophysics Data System (ADS)

Because mountain precipitation provides the majority of groundwater recharge in the western USA, an understanding of groundwater recharge and flow in mountain ranges is needed to make informed resource-management decisions. Natural tracers are excellent tools for studying these systems, but a single tracer can only provide limited information. As a result, using multiple tracers is ideal - by using several tracers, several aspects of mountain groundwater systems can be examined. For instance, groundwater stable-isotope measurements (?D and ?18O) can reveal the elevation at which the water fell as precipitation, but not the elevation at which the water was recharged. However, concentrations of dissolved gases in groundwater can be used to determine actual recharge elevations. Major-ion chemistry can provide insight into the geologic units through which the water has moved, and may also provide a qualitative indication of residence time; radioisotopes can yield more precise estimates of groundwater age. Other information is helpful for interpreting natural tracer data, including the local and regional geology, the area's climate, and the locations where groundwater recharge ('disappearing' streams) or discharge (springs and seeps) occur. A study utilizing these tools was conducted in the Chiricahua Mountains (Arizona, USA). Stable-isotope data show that precipitation from near the crest of the range is responsible for the majority of the groundwater recharge. Dissolved-gas data indicate that, while most of this recharge takes place near the crest of the range; some waters recharge in a high-permeability zone near the base of the range. Based on our observations of the range's hydraulics, the majority of this low-elevation recharge appears to be 're-recharge'---water that recharged at higher elevations, flowed underground, discharged, flowed downslope overland, then re-recharged. Major-ion chemistry data show that both volcanic (tuff and rhyolite) and sedimentary (primarily carbonates) units are conduits for groundwater flow in the range, depending on location. Dissolved-gas data demonstrate that the extent of the high-elevation recharge zone is nearly identical to the area of the range that develops snowpack. If snowpack development is a needed condition for recharge in other ranges of the western USA, groundwater recharge could be seriously impacted if current predictions for global-warming-induced changes in precipitation in the western USA (decreased percentage of precipitation falling as snow, and higher snowlines) are accurate.

Earman, S.; Phillips, F. M.

2005-12-01

361

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

NASA Astrophysics Data System (ADS)

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.

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

2014-09-01

362

Using 14C and 3H to understand groundwater flow and recharge in an aquifer window  

NASA Astrophysics Data System (ADS)

Knowledge of groundwater residence times and recharge locations are vital to the sustainable management of groundwater resources. Here we investigate groundwater residence times and patterns of recharge in the Gellibrand Valley, southeast Australia, where outcropping aquifer sediments of the Eastern View Formation form an "aquifer window" that may receive diffuse recharge and recharge from the Gellibrand River. To determine recharge patterns and groundwater flowpaths, environmental isotopes (3H, 14C, ?13C, ?18O, ?2H) are used in conjunction with groundwater geochemistry and continuous monitoring of groundwater elevation and electrical conductivity. Despite the water table fluctuating by 0.9-3.7 m annually producing estimated recharge rates of 90 and 372 mm yr-1, residence times of shallow (11-29 m) groundwater determined by 14C ages are between 100 and 10 000 years. 3H activities are negligible in most of the groundwater and groundwater electrical conductivity in individual areas remains constant over the period of study. Although diffuse local recharge is evident, the depth to which it penetrates is limited to the upper 10 m of the aquifer. Rather, groundwater in the Gellibrand Valley predominantly originates from the regional recharge zone, the Barongarook High, and acts as a regional discharge zone where upward head gradients are maintained annually, limiting local recharge. Additionally, the Gellibrand River does not recharge the surrounding groundwater and has limited bank storage. 14C ages and Cl concentrations are well correlated and Cl concentrations may be used to provide a first-order estimate of groundwater residence times. Progressively lower chloride concentrations from 10 000 years BP to the present day are interpreted to indicate an increase in recharge rates on the Barongarook High.

Atkinson, A. P.; Cartwright, I.; Gilfedder, B. S.; Cendn, D. I.; Unland, N. P.; Hofmann, H.

2014-06-01

363

Using 14C and 3H to understand groundwater flow and recharge in an aquifer window  

NASA Astrophysics Data System (ADS)

Knowledge of groundwater residence times and recharge locations is vital to the sustainable management of groundwater resources. Here we investigate groundwater residence times and patterns of recharge in the Gellibrand Valley, southeast Australia, where outcropping aquifer sediments of the Eastern View Formation form an "aquifer window" that may receive diffuse recharge from rainfall and recharge from the Gellibrand River. To determine recharge patterns and groundwater flow paths, environmental isotopes (3H, 14C, ?13C, ?18O, ?2H) are used in conjunction with groundwater geochemistry and continuous monitoring of groundwater elevation and electrical conductivity. The water table fluctuates by 0.9 to 3.7 m annually, implying recharge rates of 90 and 372 mm yr-1. However, residence times of shallow (11 to 29 m) groundwater determined by 14C are between 100 and 10 000 years, 3H activities are negligible in most of the groundwater, and groundwater electrical conductivity remains constant over the period of study. Deeper groundwater with older 14C ages has lower ?18O values than younger, shallower groundwater, which is consistent with it being derived from greater altitudes. The combined geochemistry data indicate that local recharge from precipitation within the valley occurs through the aquifer window, however much of the groundwater in the Gellibrand Valley predominantly originates from the regional recharge zone, the Barongarook High. The Gellibrand Valley is a regional discharge zone with upward head gradients that limits local recharge to the upper 10 m of the aquifer. Additionally, the groundwater head gradients adjacent to the Gellibrand River are generally upwards, implying that it does not recharge the surrounding groundwater and has limited bank storage. 14C ages and Cl concentrations are well correlated and Cl concentrations may be used to provide a first-order estimate of groundwater residence times. Progressively lower chloride concentrations from 10 000 years BP to the present day are interpreted to indicate an increase in recharge rates on the Barongarook High.

Atkinson, A. P.; Cartwright, I.; Gilfedder, B. S.; Cendn, D. I.; Unland, N. P.; Hofmann, H.

2014-12-01

364

Ground-water recharge in Escambia and Santa Rosa Counties, Florida  

USGS Publications Warehouse

Ground water is a major component of Florida's water resources, accounting for 90 percent of all public-supply and self-supplied domestic water withdrawals, and 58 percent of self-supplied commercial-industrial and agricultural withdrawals of freshwater (Marella, 1992). Ground-water is also an important source of water for streams, lakes, and wetlands in Florida. Because of their importance, a good understanding of these resources is essential for their sound development, use, and protection. One area in which our understanding is lacking is in characterizing the rate at which ground water in aquifers is recharged, and how recharge rates vary geographically. Ground-water recharge (recharge) is the replenishment of ground water by downward infiltration of water from rainfall, streams, and other sources (American Society of Civil Engineers, 1987, p. 222). The recharge rates in many areas of Florida are unknown, of insufficient accuracy, or mapped at scales that are too coarse to be useful. Improved maps of recharge rates will result in improved capabilities for managing Florida's ground-water resources. In 1989, the U.S. Geological Survey, in cooperation with the Florida Department of Environmental Regulation, began a study to delineate high-rate recharge areas in several regions of Florida (Vecchioli and others, 1990). This study resulted in recharge maps that delineated areas of high (greater than 10 inches per year) and low (0 to 10 inches per year) recharge in three counties--Okaloosa, Pasco, and Volusia Counties--at a scale of 1:100,000. This report describes the results of a similar recharge mapping study for Escambia and Santa Rosa Counties (fig. 1), in which areas of high- and low-rates of recharge to the sand-and-gravel aquifer and Upper Floridan aquifer are delineated. The study was conducted in 1992 and 1993 by the U.S. Geological Survey in cooperation with the Florida Department of Environmental Protection.

Grubbs, J.W.

1995-01-01

365

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

SciTech Connect

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.

Charles E. Russell; Tim Minor

2002-08-31

366

Recharge and sustainability of a coastal aquifer in northern Albania  

NASA Astrophysics Data System (ADS)

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.

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

2014-06-01

367

Large Scale Hydrological Modelling: Parameterisation of Groundwater Recharge  

NASA Astrophysics Data System (ADS)

There is currently worldwide interest in the effect of human activity on the global environment, especially the effect of greenhouse gases and land-use change on the global climate, and models are being developed to study both global and local effects of global changes. This research involves the development and application of GRASP (Groundwater Recharge modelling Approach with a Scaling-up Procedure) intended as a component of UP (Upscaled physically based) large-scale hydrological model. GRASP comprises two modelling schemes: SM (Soil Moisture approach) and TF (Transfer Function approach), both based on the one-dimensional Richards' equation. TF is a transfer function model for inhomogeneous vertical flow in the unsaturated zone and gives the recharge response for a short pulse of infiltration at the ground surface or percolation from the root zone. TF is point-based and its parameters are physically-based, derived using the matric potential and unsaturated hydraulic conductivity functions. SM is a simple, computationally efficient, grid-based, two parameters scheme, which are derived based on TF's point-scale aggregated response. Since TF is linear, upscaled transfer functions can be derived through area-weighted summation of point scale transfer functions. Two applications of GRASP are shown, one using data for Little Washita catchment in the ARRB (USA) and another using data from ABRACOS experiment in Central Amazon (Brazil). Although completely validation of the GRASP model needs more data, as shown, results are quite encouraging.

Pimenteldasilva, L.

2002-12-01

368

Natural water purification and water management by artificial groundwater recharge  

PubMed Central

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 earths 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

Balke, Klaus-Dieter; Zhu, Yan

2008-01-01

369

Clogging in Managed Aquifer Recharge: Hydrodynamics and Geochemistry  

NASA Astrophysics Data System (ADS)

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.

Mays, D. C.

2013-12-01

370

Combinatorial investigations of advanced Li-ion rechargeable battery electrode materials  

Microsoft Academic Search

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

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

2005-01-01

371

Estimation of groundwater recharge using the soil moisture budget method and the base-flow model  

NASA Astrophysics Data System (ADS)

Estimation of groundwater recharge is extremely important for proper management of groundwater systems. Many different approaches exist for estimating recharge. The main purpose of this paper is to apply a water balance concept with two methods to estimate the groundwater recharge in the Ching-Shui watershed, Taiwan. First, a soil moisture budget method is established to estimate the infiltration, runoff, evapotranspiration, and groundwater recharge in the watershed, where the moisture content of the soil is tracked through time. Both soil-water properties of the unsaturated zone and climatic conditions must be fully considered. Second the base-flow model uses the base-flow separation from the total streamflow discharge to obtain a measure of groundwater recharge so that groundwater evapotranspiration is negligible. In contrast to the soil moisture budget method, base-flow estimation does not require complex hydrogeologic modeling and detailed knowledge of soil characteristics. In a previous study, we suggested that high base-flow is caused by rainstorm events. Using model analysis, depths of recharge estimated by stable-base-flow analysis are adopted to obtain more reasonable groundwater recharge values. The results indicate that assessment of the average annual recharge obtained with a soil moisture budget and the base-flow are very close; the ratio of the two methods is about 95.3%.

Lee, Cheng-Haw; Yeh, Hsin-Fu; Chen, Jin-Fa

2008-06-01

372

Estimation of recharge from irrigation flows; Analysis of field and laboratory data and modeling.  

Technology Transfer Automated Retrieval System (TEKTRAN)

This work is aimed at quantifying aquifer recharge due to irrigation in the Campo de Cartagena (SE Spain). A study of recharge was conducted on an experiment plot cropped in lettuce and irrigated with a drip system. The physico-chemical and hydraulic properties of the vadose zone were characterized ...

373

DISTRIBUTION OF AREAL RECHARGE TO A DISCRETE FRACTURE NETWORK (FRACNET) MODEL USING THE ANALYTIC ELEMENT METHOD  

EPA Science Inventory

Rain water filtering down through the soil will provide recharge of the saturated fractured rock aquifer. he computer model FRACNET has been designed to distribute areal recharge into linear fracture zones in order to complete the regional water balance. n this presentation, a te...

374

Influence of model conceptualisation on one-dimensional recharge quantification: Uley South, South Australia  

NASA Astrophysics Data System (ADS)

Model conceptualisation is a key source of uncertainty in one-dimensional recharge modelling. The effects of different conceptualisations on transient recharge predictions for the semi-arid Uley South Basin, South Australia, were investigated. One-dimensional unsaturated zone modelling was used to quantify the effect of variations of (1) lithological complexity of the unsaturated zone, and (2) representation of preferential flow pathways. The simulations considered ranges of water-table depths, vegetation characteristics, and top soil thicknesses representative for the study area. Complex lithological profiles were more sensitive to the selected vegetation characteristics and water-table depth. Scenarios considering runoff infiltration into, and preferential flow through sinkholes resulted in higher and faster recharge rates. A comparison of modelled and field-based recharge estimates indicated that: (1) the model simulated plausible recharge rates, (2) only the models with preferential flow correctly reproduced the timing of recharge, and (3) preferential flow is probably redistributed in the unsaturated zone rather than passing to the water table directly. Because different but equally plausible conceptual models produce widely varying recharge rates, field-based recharge estimates are essential to constrain the modelling results.

Ordens, Carlos M.; Post, Vincent E. A.; Werner, Adrian D.; Hutson, John L.

2014-06-01

375

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

E-print Network

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

Paris-Sud XI, Université de

376

05.15 1 Auxiliary Service Enterprises, Recharge Centers, and Self Funded Activities  

E-print Network

PART V ­ FINANCE AND BUSINESS MANAGEMENT Chapter 05.15 - Auxiliary Service Enterprises, Recharge Auxiliary Service Enterprises, Recharge Centers, and Self Funded Activities B. Approval to operate any. The president shall promulgate university regulation to govern the operation of auxiliary service enterprises

Pantaleone, Jim

377

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...

378

Ether sulfones with additives for electrolytes in rechargeable lithium ion batteries  

E-print Network

Ether sulfones with additives for electrolytes in rechargeable lithium ion batteries Xiao-Guang Sun in rechargeable lithium ion battery [1-5]. In a previous publication [6] we described a series of ether sulfones electrolyte interface (SEI) needed for the long battery cycle life, they are limited in their commercial

Angell, C. Austen

379

Theoretical and Experimental Study of Vanadium-Based Fluorophosphate Cathodes for Rechargeable Batteries  

E-print Network

for the development of the rechargeable Li-ion battery is the need to store electrical energy generated by windTheoretical and Experimental Study of Vanadium-Based Fluorophosphate Cathodes for Rechargeable Batteries Maowen Xu,,§, Penghao Xiao,, Shannon Stauffer, Jie Song, Graeme Henkelman,*,, and John B

Henkelman, Graeme

380

New Nanostructured Li2S/Silicon Rechargeable Battery with High Specific Energy  

E-print Network

New Nanostructured Li2S/Silicon Rechargeable Battery with High Specific Energy Yuan Yang,,§ Matthew, California 94305 ABSTRACT Rechargeable lithium ion batteries are important energy storage devices; however, the specific energy of existing lithium ion batteries is still insufficient for many applications due

Cui, Yi

381

Groundwater recharge in natural dune systems and agricultural ecosystems in the Thar Desert region, Rajasthan, India  

NASA Astrophysics Data System (ADS)

Water and nutrient availability for crop production are critical issues in (semi)arid regions. Unsaturated-zone Cl tracer data and nutrient (NO3 and PO4) concentrations were used to quantify recharge rates using the Cl mass balance approach and nutrient availability in the Thar Desert, Rajasthan, India. Soil cores were collected in dune/interdune settings in the arid Thar Desert (near Jaisalmer) and in rain-fed (nonirrigated) and irrigated cropland in the semiarid desert margin (near Jaipur). Recharge rates were also simulated using unsaturated zone modeling. Recharge rates in sparsely vegetated dune/interdune settings in the Jaisalmer study area are 2.7-5.6 mm/year (2-3% of precipitation, 165 mm/year). In contrast, recharge rates in rain-fed agriculture in the Jaipur study area are 61-94 mm/year (10-16% of precipitation, 600 mm/year). Minimum recharge rates under current freshwater irrigated sites are 50-120 mm/year (8-20% of precipitation). Nitrate concentrations are low at most sites. Similarity in recharge rates based on SO4 with those based on Cl is attributed to a meteoric origin of SO4 and generally conservative chemical behavior in these sandy soils. Modeling results increased confidence in tracer-based recharge estimates. Recharge rates under rain-fed agriculture indicate that irrigation of 20-40% of cultivated land with 300 mm/year should be sustainable.

Scanlon, Bridget R.; Mukherjee, Abhijit; Gates, John; Reedy, Robert C.; Sinha, Amarendra K.

2010-06-01

382

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

PubMed

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

Zhang, Ruigang; Mizuno, Fuminori; Ling, Chen

2015-01-21

383

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

Microsoft Academic Search

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),

R. Ragab; J. Finch; R. Harding

1997-01-01

384

Quantifying mountain block recharge by means of catchment-scale storage-discharge relationships  

E-print Network

Quantifying mountain block recharge by means of catchment-scale storage-discharge relationships the importance of mountainous catchments for providing freshwater resources, especially in semi-arid regions, little is known about key hydrological processes such as mountain block recharge (MBR). Here we implement

Troch, Peter

385

Estimation of Groundwater Recharge of the Western Aquifer Basin Using Water Level Fluctuation Approach  

NASA Astrophysics Data System (ADS)

Quantifying groundwater recharge is sensitive for water resources management particularly in the arid and semi-arid areas. This paper presents an alternative technique for estimating annual groundwater recharge using the fluctuation of water level within an aquifer during a specific time interval as a result of the water balance of inflows and outflows. The Western Aquifer Basin (WAB), West Bank and Israel, was depicted for a case study. The estimated amount of annual recharge was also correlated with monthly rainfall rates to study the effect of rainfall variation on the generated recharge. The results confirm that the high variations of annual recharge volumes are directly linked to monthly rainfall variation. For the WAB, the annual recharge is mainly dominated by the amounts of rainfall accumulated during the four wet months i.e. November, December, January and February. On the basis of these results a multi-regression equation has been developed to consider monthly distribution of rainfall as a chief factor in forecasting annual recharge within the aquifer. This equation can be applied in the future to generate any synthetic rainfall scenarios. The average annual recharge for WAB for the period 1970-2006 was estimated at 385 million cubic meters per year (Mm3/yr).

Abu Saada, Muath; Martin, Sauter

2013-04-01

386

Groundwater Recharge as affected by Climate Change in the Nakdong River Watershed  

Microsoft Academic Search

The main purpose of this paper is to develop a model and methodology for estimating groundwater recharge quantity on a watershed scale as affected by climate change, to estimate changes in the groundwater recharge rate in their temporal and spatial aspects, and to verify results by using observed data from the national groundwater observation network. The paper also evaluates changes

L. Moung Jin

2010-01-01

387

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

Microsoft Academic Search

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

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

388

Implications of bioretention basin spatial arrangements on stormwater recharge and groundwater mounding  

Microsoft Academic Search

Stormwater bioretention basin recharge has the potential to raise the watertable and adversely impact subsurface infrastructure, undermining the benefits of naturalizing the urban water cycle. This research examined how groundwater mounding responded to three spatial arrangements of bioretention basins, from separated units to clustered units to single units, and changes in hydraulic conductivity, storm intensity, and antecedent recharge, for 28

T. Endreny; V. Collins

2009-01-01

389

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

E-print Network

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

Kumar, C.P.

390

A time series approach to inferring groundwater recharge using the water table fluctuation method  

Microsoft Academic Search

The water table fluctuation method for determining recharge from precipitation and water table measurements was originally developed on an event basis. Here a new multievent time series approach is presented for inferring groundwater recharge from long-term water table and precipitation records. Additional new features are the incorporation of a variable specific yield based upon the soil moisture retention curve, proper

Russell S. Crosbie; Philip Binning; Jetse D. Kalma

2005-01-01

391

3/4/2014 Technologyuses micro-windmills to recharge cell phones http://www.innovationtoronto.com/2014/01/technology-microwindmills-recharge-cell-phones/ 1/4  

E-print Network

3/4/2014 » Technologyuses micro-windmills to recharge cell phones http://www.innovationtoronto.com/2014/01/technology-microwindmills-recharge-cell-phones/ 1/4 INNOVATION & INNOVATION NEEDED: THINGS Inside Your Car Technology uses micro-windmills to recharge cell phones Flat panels with thousand

Chiao, Jung-Chih

392

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

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

Chiao, Jung-Chih

393

2/1/2014 TinyMicro-Robotic Windmill Recharges Phone Batteries | The DailyFusion http://dailyfusion.net/2014/01/tiny-micro-windmill-recharges-phone-batteries-25864/ 1/4  

E-print Network

2/1/2014 TinyMicro-Robotic Windmill Recharges Phone Batteries | The DailyFusion http://dailyfusion.net/2014/01/tiny-micro-windmill-recharges-phone-batteries-25864/ 1/4 Knowledge is Power prev next A UT a relationship with UT Arlington. Tiny Micro-Robotic Windmill Recharges Phone Batteries January 14, 2014 @ 09

Chiao, Jung-Chih

394

2/1/2014 TinyMicro-Robotic Windmill Recharges Phone Batteries -Paperblog http://en.paperblog.com/tiny-micro-robotic-windmill-recharges-phone-batteries-769045/ 1/5  

E-print Network

with the micro-windmill idea when we showed the demo video of working devices," Rao said. "It was something2/1/2014 TinyMicro-Robotic Windmill Recharges Phone Batteries - Paperblog http://en.paperblog.com/tiny-micro-robotic-windmill-recharges-phone-batteries-769045/ 1/5 HOME > SOCIETY Tiny Micro-Robotic Windmill Recharges Phone Batteries Posted on the 14 January

Chiao, Jung-Chih

395

1/25/2014 WhyNot Use Micro Windmills to Recharge Your Devices ? -TECHVOIZE -Where Tech Talks http://www.techvoize.com/micro-windmills-to-recharge-your-devices/ 1/3  

E-print Network

1/25/2014 WhyNot Use Micro Windmills to Recharge Your Devices ? - TECHVOIZE - Where Tech Talks http://www.techvoize.com/micro-windmills-to-recharge-your-devices/ 1/3 RELATED ARTICLES Nokia Normandy Leaked Rumors; Dream Concept (VIDEO) January 25, 2014 Google Why Not Use Micro Windmills to Recharge Your Devices ? Engineers at the University of Texas Arlington

Chiao, Jung-Chih

396

3/4/2014 Micro windmills maysoon recharge your mobile phone -Yahoo News Singapore http://sg.news.yahoo.com/micro-windmills-may-soon-recharge-mobile-phone-091158453.html 1/1  

E-print Network

of houses or building to harvest energy for lighting, security or environmental sensing and wireless3/4/2014 Micro windmills maysoon recharge your mobile phone - Yahoo News Singapore http://sg.news.yahoo.com/micro-windmills-may-soon-recharge-mobile-phone-091158453.html 1/1 Micro windmills may soon recharge your mobile phone GMA News Online ­ Mon, Jan 13, 2014

Chiao, Jung-Chih

397

2/6/2014 Micro-Windmills Can Recharge Cellphones -CIO.com http://www.cio.com/article/746417/Micro_Windmills_Can_Recharge_Cellphones 1/4  

E-print Network

2/6/2014 Micro-Windmills Can Recharge Cellphones - CIO.com http://www.cio.com/article/746417/Micro_Windmills_Can_Recharge_Cellphones Recharge Cellphones Researchers at the University of Texas at Arlington have designed a miniscule windmill

Chiao, Jung-Chih

398

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

USGS Publications Warehouse

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.

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

1992-01-01

399

Dissolved Organic Carbon Influences Microbial Community Composition and Diversity in Managed Aquifer Recharge Systems  

PubMed Central

This study explores microbial community structure in managed aquifer recharge (MAR) systems across both laboratory and field scales. Two field sites, the Taif River (Taif, Saudi Arabia) and South Platte River (Colorado), were selected as geographically distinct MAR systems. Samples derived from unsaturated riverbed, saturated-shallow-infiltration (depth, 1 to 2 cm), and intermediate-infiltration (depth, 10 to 50 cm) zones were collected. Complementary laboratory-scale sediment columns representing low (0.6 mg/liter) and moderate (5 mg/liter) dissolved organic carbon (DOC) concentrations were used to further query the influence of DOC and depth on microbial assemblages. Microbial density was positively correlated with the DOC concentration, while diversity was negatively correlated at both the laboratory and field scales. Microbial communities derived from analogous sampling zones in each river were not phylogenetically significantly different on phylum, class, genus, and species levels, as determined by 16S rRNA gene pyrosequencing, suggesting that geography and season exerted less sway than aqueous geochemical properties. When field-scale communities derived from the Taif and South Platte River sediments were grouped together, principal coordinate analysis revealed distinct clusters with regard to the three sample zones (unsaturated, shallow, and intermediate saturated) and, further, with respect to DOC concentration. An analogous trend as a function of depth and corresponding DOC loss was observed in column studies. Canonical correspondence analysis suggests that microbial classes Betaproteobacteria and Gammaproteobacteria are positively correlated with DOC concentration. Our combined analyses at both the laboratory and field scales suggest that DOC may exert a strong influence on microbial community composition and diversity in MAR saturated zones. PMID:22798375

Li, Dong; Sharp, Jonathan O.; Saikaly, Pascal E.; Ali, Shahjahan; Alidina, Mazahirali; Alarawi, Mohammed S.; Keller, Stephanie; Hoppe-Jones, Christiane

2012-01-01

400

Raising the cycling stability of aqueous lithium-ion batteries by eliminating oxygen in the electrolyte  

NASA Astrophysics Data System (ADS)

Aqueous lithium-ion batteries may solve the safety problem associated with lithium-ion batteries that use highly toxic and flammable organic solvents, and the poor cycling life associated with commercialized aqueous rechargeable batteries such as lead-acid and nickel-metal hydride systems. But all reported aqueous lithium-ion battery systems have shown poor stability: the capacity retention is typically less than 50% after 100 cycles. Here, the stability of electrode materials in an aqueous electrolyte was extensively analysed. The negative electrodes of aqueous lithium-ion batteries in a discharged state can react with water and oxygen, resulting in capacity fading upon cycling. By eliminating oxygen, adjusting the pH values of the electrolyte and using carbon-coated electrode materials, LiTi2(PO4)3/Li2SO4/LiFePO4 aqueous lithium-ion batteries exhibited excellent stability with capacity retention over 90% after 1,000 cycles when being fully charged/discharged in 10 minutes and 85% after 50 cycles even at a very low current rate of 8 hours for a full charge/discharge offering an energy storage system with high safety, low cost, long cycling life and appropriate energy density.

Luo, Jia-Yan; Cui, Wang-Jun; He, Ping; Xia, Yong-Yao

2010-09-01

401

Raising the cycling stability of aqueous lithium-ion batteries by eliminating oxygen in the electrolyte.  

PubMed

Aqueous lithium-ion batteries may solve the safety problem associated with lithium-ion batteries that use highly toxic and flammable organic solvents, and the poor cycling life associated with commercialized aqueous rechargeable batteries such as lead-acid and nickel-metal hydride systems. But all reported aqueous lithium-ion battery systems have shown poor stability: the capacity retention is typically less than 50% after 100 cycles. Here, the stability of electrode materials in an aqueous electrolyte was extensively analysed. The negative electrodes of aqueous lithium-ion batteries in a discharged state can react with water and oxygen, resulting in capacity fading upon cycling. By eliminating oxygen, adjusting the pH values of the electrolyte and using carbon-coated electrode materials, LiTi(2)(PO(4))(3)/Li(2)SO(4)/LiFePO(4) aqueous lithium-ion batteries exhibited excellent stability with capacity retention over 90% after 1,000 cycles when being fully charged/discharged in 10 minutes and 85% after 50 cycles even at a very low current rate of 8 hours for a full charge/discharge offering an energy storage system with high safety, low cost, long cycling life and appropriate energy density. PMID:20729897

Luo, Jia-Yan; Cui, Wang-Jun; He, Ping; Xia, Yong-Yao

2010-09-01

402

Rheology of aqueous foams  

NASA Astrophysics Data System (ADS)

Aqueous foams are suspensions of bubbles inside aqueous phases. Their multiphasic composition leads to a complex rheological behavior that is useful in numerous applications, from oil recovery to food/cosmetic processing. Their structure is very similar to the one of emulsions, so that both materials share common mechanical properties. In particular, the presence of surfactants at the gas-liquid interfaces leads to peculiar interfacial and dissipative properties. Foam rheology has been an active research topics and is already reported in several reviews, most of them covering rheometry measurements at the scale of the foam, coupled with interpretations at the local scale of bubbles or interfaces. In this review, we start following this approach, then we try to cover the multiscale features of aqueous foam flows, emphasizing regimes where intermediate length scales need to be taken into account or regimes fast enough regarding internal time scales so that the flow goes beyond the quasi-static limit. xml:lang="fr"

Dollet, Benjamin; Raufaste, Christophe

2014-10-01

403

Responsive aqueous foams.  

PubMed

Remarkable properties have emerged recently for aqueous foams, including ultrastability and responsiveness. Responsive aqueous foams refer to foams for which the stability can be switched between stable and unstable states with a change in environment or with external stimuli. Responsive foams have been obtained from various foam stabilizers, such as surfactants, proteins, polymers, and particles, and with various stimuli. Different strategies have been developed to design this type of soft material. We briefly review the two main approaches used to obtain responsive foams. The first approach is based on the responsiveness of the interfacial layer surrounding the gas bubbles, which leads to responsive foams. The second approach is based on modifications that occur in the aqueous phase inside the foam liquid channels to tune the foam stability. We will highlight the most sophisticated approaches, which use light, temperature, and magnetic fields and lead to switchable foam stability. PMID:25384466

Fameau, Anne-Laure; Carl, Adrian; Saint-Jalmes, Arnaud; von Klitzing, Regine

2015-01-12

404

78 FR 62495 - Special Conditions: Learjet Model 35, 35A, 36, and 36A Airplanes; Rechargeable Lithium-Ion...  

Federal Register 2010, 2011, 2012, 2013

...and 36A Airplanes; Rechargeable Lithium-Ion Batteries and Battery Systems AGENCY: Federal...feature associated with rechargeable lithium-ion batteries and battery systems. These batteries...equipment that uses rechargeable lithium-ion battery systems in Learjet Model 35,...

2013-10-22

405

Electrochemical Properties of Nanostructured Al1-xCux Alloys as Anode Materials for Rechargeable Lithium-Ion Batteries  

E-print Network

challenge to use metallic alloys as anodes in rechargeable lithium batteries is to improve their cycling anode materials for rechargeable lithium-ion batteries have been widely investigated becauseElectrochemical Properties of Nanostructured Al1-xCux Alloys as Anode Materials for Rechargeable

Ceder, Gerbrand

406

Optimal transmission schemes for parallel and fading Gaussian broadcast channels with an energy harvesting rechargeable transmitter q  

E-print Network

. The transmit- ter is able to harvest energy from nature in order to recharge its battery. The energy is modeled the transmission starts. Although power allocation problem in traditional systems with non-rechargeable batteries techniques, off-line scheduling with rechargeable batteries in these two channel models are considerably

Ulukus, Sennur

407

3096 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL. 12, NO. 6, JUNE 2013 Distributed Sampling Rate Control for Rechargeable  

E-print Network

Rate Control for Rechargeable Sensor Nodes with Limited Battery Capacity Yongmin Zhang, Student Member. Most of existing works do not consider the limited capacity of rechargeable battery. In this paper, we the efficiency of the proposed algorithms. Index Terms--Rechargeable sensor networks, limited battery capacity

Shen, Xuemin "Sherman"

408

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

E-print Network

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 scaling of hydraulic response to recharge in fractured aquifers: Insights from a frequency domain analysis

Paris-Sud XI, Université de

409

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

NASA Astrophysics Data System (ADS)

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.

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

2014-01-01

410

Aqueous carbonaceous slurries  

SciTech Connect

Aqueous carbonaceous slurries having reduced viscosity, a stabilized network of coal in water and improved pumpability are obtained by having present a salt of naphthalenesulfonic acid formaldehyde condensate and at least one water soluble polymer selected from the group consisting of gum karaya, mixtures of gum karaya and polyacrylamide and polysaccaride modified with polyacrylate. For example, a mixture of 61.5% by weight of ammonium naphthalenesulfonic acid formaldehyde condensate and 38.5% by weight of gum karaya can be added to an aqueous coal slurry in an amount of 0.13% by weight of the slurry.

Schick, M.J.; Knitter, K.A.

1983-11-15

411

Use of Constructed Wetlands for Polishing Recharge Wastewater  

NASA Astrophysics Data System (ADS)

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.

Cardwell, W.

2009-12-01

412

Zeolite in horizontal permeable reactive barriers for artificial groundwater recharge  

NASA Astrophysics Data System (ADS)

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.

Leal, Mara; Martnez-Hernndez, Virtudes; Lillo, Javier; Meffe, Raffaella; de Bustamante, Irene

2013-04-01

413

Artificial recharge in arid zone- Example from the Arava Valley- Israel  

NASA Astrophysics Data System (ADS)

In arid zones direct recharge from rainfall is negligible. The indirect recharge like recharging of flood water is the principal source of water of the alluvial aquifers in arid environment. Flooding of ephemeral streams occur as a consequence of the rain intensity and its pattern, the basin size and the geomorphic settings as slops, vegetation and soil properties. In the Arava Valley there are several reservoirs that act as diversion levees. They were constructed on few ravines for two reasons. (1) to store large volumes of floodwater for direct use in nearby agricultural fields. (2) to enhance the recharge to the local alluvial aquifers. Since flood duration is relatively short compared to the infiltration (percolation) rate, it was assumed that by storing the water in the reservoirs it will increase the recharge volume because of higher water head, longer resistance time and larger surface area available for infiltration. Unfortunately, accumulation of silts and clays in the reservoirs clogged them to direct infiltration. The accumulation of silt and clay in the reservoirs is typically to arid zones where lack of vegetation cover creates a very high erosion rate and transportation of large amounts of sediment at the duration of the water flowing on the stream channel bed. To bypass the problem of reduction in the direct recharge inside the reservoirs because of clogging, and to continue the artificial recharge into the aquifer, two kinds of artificial recharge system are operating in the Arava Valley. In one site we use a system that is similar to the conventional spreading ponds system. The big reservoir is using to store the flood water and as a settling pond. The clean water is diverted to three infiltration ponds. In the rest five reservoirs we construct a drainage pipeline close to the bottom of the levee that allow us to release the clean water (after settling of the fine particles) downstream in a slow rate that is much more efficiency for artificial recharge than in high velocity. Monitoring after the recharge water is very important and in some cases very problematic. In cases where the groundwater is shallow (10-20 m' depth) the response to the recharge is quickly and takes few days (rising in water level and or decreasing in the salinity). But in cases where the water level is very deep (about 60-110 m' in most of the area) the response to the recharge can takes few months. At this condition, it is impossible to distinguish whether the rising in the water level and or decreasing in the salinity is a result of the artificial recharge or it is a result of natural lateral flow in the aquifer itself.

Guttman, Joseph

2010-05-01

414

A rechargeable hydrogen battery based on Ru catalysis.  

PubMed

Apart from energy generation, the storage and liberation of energy are among the major problems in establishing a sustainable energy supply chain. Herein we report the development of a rechargeable H2 battery which is based on the principle of the Ru-catalyzed hydrogenation of CO2 to formic acid (charging process) and the Ru-catalyzed decomposition of formic acid to CO2 and H2 (discharging process). Both processes are driven by the same catalyst at elevated temperature either under pressure (charging process) or pressure-free conditions (discharging process). Up to five charging-discharging cycles were performed without decrease of storage capacity. The resulting CO2/H2 mixture is free of CO and can be employed directly in fuel-cell technology. PMID:24803414

Hsu, Shih-Fan; Rommel, Susanne; Eversfield, Philipp; Muller, Keven; Klemm, Elias; Thiel, Werner R; Plietker, Bernd

2014-07-01

415

Identifying Recharge from Tropical Cyclonic Storms, Baja California Sur, Mexico.  

PubMed

Groundwater in the Todos Santos watershed in southern Baja California, and throughout the peninsula south of latitude 28N, 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 ?(18) O values?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

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

2014-03-17

416

Resilient design of recharging station networks for electric transportation vehicles  

SciTech Connect

As societies shift to 'greener' means of transportation using electricity-driven vehicles one critical challenge we face is the creation of a robust and resilient infrastructure of recharging stations. A particular issue here is the optimal location of service stations. In this work, we consider the placement of battery replacing service station in a city network for which the normal traffic flow is known. For such known traffic flow, the service stations are placed such that the expected performance is maximized without changing the traffic flow. This is done for different scenarios in which roads, road junctions and service stations can fail with a given probability. To account for such failure probabilities, the previously developed facility interception model is extended. Results show that service station failures have a minimal impact on the performance following robust placement while road and road junction failures have larger impacts which are not mitigated easily by robust placement.

Kris Villez; Akshya Gupta; Venkat Venkatasubramanian

2011-08-01

417

Chemical lithium extraction from manganese oxides for lithium rechargeable batteries  

NASA Astrophysics Data System (ADS)

Chemical lithium extraction has been carried out on the following manganese oxides: the spinel-type compounds LiMn2O4 and Li(4/3)Mn(5/3)O4, and the rocksalt-related compound Li2MnO3. Lithium can be partially removed chemically from these compounds without destroying the host framework. Some compounds obtained by this method have been tested as cathodic materials in rechargeable lithium cells. Electrochemical results and X-ray diffraction patterns of cycled cathodes are presented. Electrochemical insertion/extraction of Li(+) ions occurs with tetragonal/cubic distortion in the spinel framework, whereas Li(+) ions can move in compounds having the rocksalt structure, without significant modification of the X-ray patterns.

Lubin, F.; Lecerf, A.; Broussely, M.; Labat, J.

1991-03-01

418

Layered cathode materials for lithium ion rechargeable batteries  

DOEpatents

A number of materials with the composition Li.sub.1+xNi.sub..alpha.Mn.sub..beta.Co.sub..gamma.M'.sub..delta.O.sub.2-- zF.sub.z (M'=Mg,Zn,Al,Ga,B,Zr,Ti) for use with rechargeable batteries, wherein x is between about 0 and 0.3, .alpha. is between about 0.2 and 0.6, .beta. is between about 0.2 and 0.6, .gamma. is between about 0 and 0.3, .delta. is between about 0 and 0.15, and z is between about 0 and 0.2. Adding the above metal and fluorine dopants affects capacity, impedance, and stability of the layered oxide structure during electrochemical cycling.

Kang, Sun-Ho (Naperville, IL); Amine, Khalil (Downers Grove, IL)

2007-04-17

419

Recent advances in rechargeable battery materials: a chemist's perspective.  

PubMed

The constant increase in global energy demand, together with the awareness of the finite supply of fossil fuels, has brought about an imperious need to take advantage of renewable energy sources. At the same time, concern over CO(2) emissions and future rises in the cost of gasoline has boosted technological efforts to make hybrid and electric vehicles available to the general public. Energy storage is a vital issue to be addressed within this scenario, and batteries are certainly a key player. In this tutorial review, the most recent and significant scientific advances in the field of rechargeable batteries, whose performance is dependent on their underlying chemistry, are covered. In view of its utmost current significance and future prospects, special emphasis is given to progress in lithium-based technologies. PMID:19690737

Palacn, M Rosa

2009-09-01

420

Status of the development of rechargeable lithium cells  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

421

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

SciTech Connect

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.

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

1990-01-01

422

Using isotopes for design and monitoring of artificial recharge systems  

USGS Publications Warehouse

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.

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

2013-01-01

423

Continuous aqueous tritium monitor  

DOEpatents

An apparatus for a selective on-line determination of aqueous tritium concentration is disclosed. A moist air stream of the liquid solution being analyzed is passed through a permeation dryer where the tritium and moisture and selectively removed to a purge air stream. The purge air stream is then analyzed for tritium concentration, humidity, and temperature, which allows computation of liquid tritium concentration.

McManus, Gary J. (Idaho Falls, ID); Weesner, Forrest J. (Idaho Falls, ID)

1989-05-30

424

The chemistry and status of rechargeable molten-salt batteries  

SciTech Connect

The chemistry and the state of development of rechargeable molten salt cells and batteries of current interest are reviewed in this work. Molten-salt cells offer the most attractive combination of high specific energy (100-200 Wh/kg), high specific power (50-200 W/kg), and long cycle life (300-1500 cycles) of any rechargeable cells under investigation at this time. It is these important features that justify the development and application of cells that have the disadvantages of operation at elevated temperatures, and difficult materials problems. There are two major categories of molten-salt cells: those in which the molten salt is the sole electrolyte, and those in which the molten salt serves as a reactant and as an auxiliary electrolyte (the main electrolyte is a solid). In the first category are such cells as LiAl/LiCl-KCl/FeS, LiAl/LiCl-KCl/FeS/sub 2/, and Li/sub 4/Si/LiCl-KCl/FeS/sub 2/; in the second category are Na/Na/sub 2/O . xAl/sub 2/O/sub 3//Na/sub 2/S /SUB n/ -S, Na/Na/sup +/ glass/Na/sub 2/S /SUB n/ -S, Na/Na/sub 2/O . xAl/sub 2/O/sub 3//SCl/sub 3/AlCl/sub 4/ in NaCl-AlCl/sub 3/, and Li/Li/sub 2/O/LiNO/sub 3/-KNO/sub 3//V/sub 2/O/sub 5/. These cells have operating temperatures ranging from 150 to 475/sup 0/C, and all must be sealed from the atmosphere because of the alkali metal reactants and hydrolytic degradation of molten salt electrolytes.

Cairns, E.J.; Mamantov, G.; Tischer, R.P.; Vissers, D.R.

1983-05-01

425

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

426

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

NASA Astrophysics Data System (ADS)

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.

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

2014-11-01

427

Vertical carbon-14 profiles for resolving spatial variability in recharge in arid environments  

NASA Astrophysics Data System (ADS)

Groundwater age tracers are often measured to help constrain estimates of groundwater recharge, especially in arid environments where other methods are unsuitable. However multiple processes can influence the shape of vertical tracer profiles in an aquifer including (1) variation in tracer input concentrations from the unsaturated zone, (2) the role of diffusion in transporting tracer into the aquifer when fluxes are low and (3) spatial variability in recharge. This study demonstrates the influence of spatially variable recharge and spatially variable carbon-14 (14C) activities in the unsaturated zone on vertical 14C profiles in groundwater. Through groundwater flow and solute transport modelling, we demonstrate that recharge estimated from single point measurements of 14C may be wrong more than an order of magnitude when unsaturated zone 14C activities and recharge vary spatially. We then present a case study from the Ti Tree Basin in arid central Australia, where detailed profiles of 14C activity in unsaturated zone gas and groundwater have been measured, and spatial variability in unsaturated zone 14C is observed (ranging from 54 to 106 pMC above the watertable). Through modelling our data, we show that when unsaturated zone 14C activities are known, measurement of the 14C profile can help constrain estimates of recharge and its spatial variability. This approach improves our understanding of groundwater flow in the Ti Tree Basin, by showing mountain front recharge to be an important mechanism.

Wood, Cameron; Cook, Peter G.; Harrington, Glenn A.

2015-01-01

428

Estimation of shallow ground-water recharge in the Great Lakes basin  

USGS Publications Warehouse

This report presents the results of the first known integrated study of long-term average ground-water recharge to shallow aquifers (generally less than 100 feet deep) in the United States and Canada for the Great Lakes, upper St. Lawrence, and Ottawa River Basins. The approach used was consistent throughout the study area and allows direct comparison of recharge rates in disparate parts of the study area. Estimates of recharge are based on base-flow estimates for streams throughout the Great Lakes Basin and the assumption that base flow in a given stream is equal to the amount of shallow ground-water recharge to the surrounding watershed, minus losses to evapotranspiration. Base-flow estimates were developed throughout the study area using a single model based on an empirical relation between measured base-flow characteristics at streamflow-gaging stations and the surficial-geologic materials, which consist of bedrock, coarse-textured deposits, fine-textured deposits, till, and organic matter, in the surrounding surface-water watershed. Model calibration was performed using base-flow index (BFI) estimates for 959 stations in the U.S. and Canada using a combined 28,784 years of daily streamflow record determined using the hydrograph-separation software program PART. Results are presented for watersheds represented by 8-digit hydrologic unit code (HUC, U.S.) and tertiary (Canada) watersheds. Recharge values were lowest (1.6-4.0 inches/year) in the eastern Lower Peninsula of Michigan; southwest of Green Bay, Wisconsin; in northwestern Ohio; and immediately south of the St. Lawrence River northeast of Lake Ontario. Recharge values were highest (12-16.8 inches/year) in snow shadow areas east and southeast of each Great Lake. Further studies of deep aquifer recharge and the temporal variability of recharge would be needed to gain a more complete understanding of ground-water recharge in the Great Lakes Basin.

Neff, B.P.; Piggott, A.R.; Sheets, R.A.

2006-01-01

429

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

USGS Publications Warehouse

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.

Ku, Henry; Hagelin, Nathan; Buxton, Herbert

1992-01-01

430

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

USGS Publications Warehouse

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.

Thompson, Ryan F.

2002-01-01

431

Battery charging control methods, electric vehicle charging methods, battery charging apparatuses and rechargeable battery systems  

DOEpatents

Battery charging control methods, electric vehicle charging methods, battery charging apparatuses and rechargeable battery systems. According to one aspect, a battery charging control method includes accessing information regarding a presence of at least one of a surplus and a deficiency of electrical energy upon an electrical power distribution system at a plurality of different moments in time, and using the information, controlling an adjustment of an amount of the electrical energy provided from the electrical power distribution system to a rechargeable battery to charge the rechargeable battery.

Tuffner, Francis K. (Richland, WA); Kintner-Meyer, Michael C. W. (Richland, WA); Hammerstrom, Donald J. (West Richland, WA); Pratt, Richard M. (Richland, WA)

2012-05-22

432

Comparison of spatially and temporally distributed recharge simulated using coupled and decoupled watershed hydrology models  

NASA Astrophysics Data System (ADS)

Estimation of the temporal and spatial distribution of watershed-scale recharge is often required for the development of transient groundwater-flow models and for quantifying water budgets. The temporal distribution of recharge has often been empirically estimated by scaling precipitation distributions. For larger watersheds, however, temporal change in the spatial distribution of recharge is affected by spatial and temporal variability in precipitation and air temperature, combined with the effects of heterogeneity in the physical characteristics of the watershed; these factors make it difficult to represent transient recharge using empirical scaling methods. Precipitation-runoff models, calibrated to available streamflow records, have been used to simulate the changing distribution and magnitude of recharge, but the uncertainty in simulated recharge estimates usually is high due to the uncertainty in input data and other components of the water balance. In this study, GSFLOW, an integrated hydrologic model, was used to evaluate differences in simulated water balances and the magnitude and distribution of transient recharge using decoupled and coupled simulations of surface-water and groundwater flow in the Santa Rosa Plain watershed (SRPW), California, USA. GSFLOW is an integration of the precipitation-runoff model PRMS and the groundwater flow model MODFLOW. GSFLOW was run as a decoupled (PRMS-only) precipitation-runoff model, independent of the MODFLOW, to develop a preliminary ensemble of estimated water balances and recharge simulations. The ensemble consisted of a set of 60-year (water years 1950 through 2010) daily simulation results, all of which provided satisfactory calibration results to available daily streamflow records at 12 gaging sites within the SRPW. The PRMs parameter files developed for the calibrated PRMS-only simulations were used as input for the coupled GSFLOW simulations that were calibrated to available well hydrographs for water years 1976 through 2008. The PRMS-only simulated water budgets and transient recharge results were compared to those produced by GSFLOW for water years 1976 through 2008. The comparison indicated that recharge estimated by GSFLOW was in many cases significantly different than recharge estimated by the PRMS-only model. Differences in recharge were pronounced along numerous stream channels in the SRPW due to the ability to directly simulate surface water - groundwater interaction in GSFLOW. In most cases, locations simulated as dominantly groundwater discharge zones (such as gaining reaches) using GSFLOW had decreased recharge relative to the decoupled PRMS-only simulations, whereas losing reaches had increased recharge compared to the PRMS-only simulations. Although the coupled GSFLOW model provided more conceptually correct recharge and water balance results, application of the decoupled model to develop preliminary recharge and water budget results allowed for a more efficient calibration of the coupled model because of the much faster runtime of PRMS-only simulations and the ease of developing preliminary water budget and recharge estimates.

Hevesi, J. A.; Woolfenden, L. R.; Niswonger, R. G.; Nishikawa, T.

2011-12-01

433

Hierarchical nanostructured NiCo2O4 as an efficient bifunctional non-precious metal catalyst for rechargeable zinc-air batteries.  

PubMed

A nickel-doped cobalt oxide spinel structure is a promising non-precious metal electrocatalyst for oxygen evolution and oxygen reduction in rechargeable metal-air batteries and water electrolyzers operating with alkaline electrolytes. One dimensional NiCo2O4 (NCO) nanostructures were prepared by using a simple electrospinning technique with two different metal precursors (metal nitrate/PAN and metal acetylacetonate/PAN). The effect of precursor concentration on the morphologies was investigated. Single-phase, NCO with an average diameter of 100 nm, porous interconnected fibrous morphology was revealed by FESEM and FETEM analysis. The hierarchical nanostructured 1D-spinel NiCo2O4 materials showed a remarkable electrocatalytic activity towards oxygen reduction and evolution in an aqueous alkaline medium. The extraordinary bi-functional catalytic activity towards both ORR and OER was observed by the low over potential (0.84 V), which is better than that of noble metal catalysts [Pt/C (1.16 V), Ru/C (1.01 V) and Ir/C (0.92 V)], making them promising cathode materials for metal-air batteries. Furthermore, the rechargeable zinc-air battery with NCO-A1 as a bifunctional electrocatalyst displays high activity and stability during battery discharge, charge, and cycling processes. PMID:24496578

Prabu, Moni; Ketpang, Kriangsak; Shanmugam, Sangaraju

2014-03-21

434

Aqueous chemistry of iodine  

SciTech Connect

The chemistry of iodine has been examined in aqueous solutions of pH 6 to 10 containing 2500 ppM boron as H/sub 3/BO/sub 3/ at temperatures up to 150/sup 0/C using absorption spectrophotometry to identify and monitor the iodine species present. Kinetic rate constants for the disproportionation of the HOI intermediate, 3HOI= IO/sub 3//sup -/ + 2I/sup -/ + 3H/sup +/, have been measured as a function of pH even though no direct spectral evidence for HOI itself has been observed. An HOI partition coefficient >10/sup 4/ has been estimated; results of ionic strength tests are consistent with HOI being present as an uncharged triatomic species in solution. Redox and radiation effects on the aqueous iodine chemistry have also been described. 11 refs., 2 figs., 3 tabs.

Toth, L.M.; Pannell, K.D.; Kirkland, O.L.

1984-01-01

435

Tunable Aqueous Virtual Micropore  

SciTech Connect

A charged microparticle can be trapped in an aqueous environment by forming a narrow virtual pore - a cylindrical space region in which the particle motion in the radial direction is limited by forces emerging from dynamical interactions of the particle charge and dipole moment with an external radiofrequency quadrupole electric field. If the particle satisfies the trap stability criteria, its mean motion is reduced exponentially with time due to the viscosity of the aqueous environment; thereafter the long-time motion of particle is subject only to random, Brownian fluctuations, whose magnitude, influenced by the electrophoretic and dielectrophoretic effects and added to the particle size, determines the radius of the virtual pore, which is demonstrated by comparison of computer simulations and experiment. The measured size of the virtual nanopore could be utilized to estimate the charge of a trapped micro-object.

Park, Jae Hyun nmn [ORNL; Guan, Weihau [Yale University; Reed, Mark A [Yale University; Krstic, Predrag S [ORNL

2012-01-01

436

Continuous aqueous tritium monitor  

DOEpatents

An apparatus for a selective on-line determination of aqueous tritium concentration is disclosed. A moist air stream of the liquid solution being analyzed is passed through a permeation dryer where the tritium and moisture are selectively removed to a purge air stream. The purge air stream is then analyzed for tritium concentration, humidity, and temperature, which allows computation of liquid tritium concentration. 2 figs.

McManus, G.J.; Weesner, F.J.

1987-10-19

437

Mars aqueous chemistry experiment  

NASA Technical Reports Server (NTRS)

The Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. Progress for the first year MACE PIDDP is reported in two major areas of effort: (1) fluids handling concepts, definition, and breadboard fabrication and (2) aqueous chemistry ion sensing technology and test facility integration. A fluids handling breadboard was designed, fabricated, and tested at Mars ambient pressure. The breadboard allows fluid manipulation scenarios to be tested under the reduced pressure conditions expected in the Martian atmosphere in order to validate valve operations, orchestrate analysis sequences, investigate sealing integrity, and to demonstrate efficacy of the fluid handling concept. Additional fluid manipulation concepts have also been developed based on updated MESUR spacecraft definition. The Mars Aqueous Chemistry Experiment Ion Selective Electrode (ISE) facility was designed as a test bed to develop a multifunction interface for measurements of chemical ion concentrations in aqueous solution. The interface allows acquisition of real time data concerning the kinetics and heats of salt dissolution, and transient response to calibration and solubility events. An array of ion selective electrodes has been interfaced and preliminary calibration studies performed.

Clark, Benton C.; Mason, Larry W.

1993-01-01

438

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

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.

Lopes, Thomas J.; Evetts, David M.

2004-01-01

439

Theory of SEI Formation in Rechargeable Batteries: Capacity Fade, Accelerated Aging and Lifetime Prediction  

E-print Network

Cycle life is critically important in applications of rechargeable batteries, but lifetime prediction is mostly based on empirical trends, rather than mathematical models. In practical lithium-ion batteries, capacity fade ...

Pinson, Matthew Bede

440

Amorphous Metallic Glass as New High Power and Energy Density Anodes For Lithium Ion Rechargeable Batteries  

E-print Network

We have investigated the use of aluminum based amorphous metallic glass as the anode in lithium ion rechargeable batteries. Amorphous metallic glasses have no long-range ordered microstructure; the atoms are less closely ...

Meng, Shirley Y.

441

USGS Professional Paper 1703--Ground-Water Recharge in the Arid and Semiarid Southwestern United States--  

E-print Network

States-- Appendix--1 Thermal Methods for Investigating Ground-Water Recharge By Kyle W. Blasch, Jim of hydrologic processes have appeared elsewhere (Stonestrom and Blasch, 2003; Niswonger and Prudic, 2003

442

Electrically recharged battery employing a packed/spouted bed metal particle electrode  

DOEpatents

A secondary metal air cell, employing a spouted/packed metal particle bed and an air electrode. More specifically a zinc air cell well suited for use in electric vehicles which is capable of being either electrically or hydraulically recharged.

Siu, Stanley C. (Alameda, CA); Evans, James W. (Piedmont, CA); Salas-Morales, Juan (Berkeley, CA)

1995-01-01

443

77 FR 2437 - Special Conditions: Gulfstream Aerospace Corporation, Model GVI Airplane; Rechargeable Lithium...  

Federal Register 2010, 2011, 2012, 2013

...Conditions No. 25-455-SC] Special Conditions: Gulfstream Aerospace Corporation, Model GVI Airplane; Rechargeable Lithium Batteries...SUMMARY: These special conditions are issued for the Gulfstream Aerospace Corporation (GAC) Model GVI airplane. This airplane...

2012-01-18

444

Arsenic mobilization and attenuation by mineral?water interactions: implications for managed aquifer recharge  

EPA Science Inventory

Managed aquifer recharge (MAR) has a potential for addressing deficits in water supplies worldwide. It is also widely used for preventing saltwater intrusion, maintaining the groundwater table, and augmenting ecological stream flows among many beneficial environmental application...

445

Institutional innovation in water management : the case of Mexico City's recharge wells  

E-print Network

This thesis explores the difference in adoption patterns of water recharge well technology in Mexico City both by local entities and the central city government. The research finds that this technology, originally designed ...

Correa Ibargengoitia, Jos Antonio

2010-01-01

446

Recharge Data Package for the 2005 Integrated Disposal Facility Performance Assessment  

SciTech Connect

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.

Fayer, Michael J.; Szecsody, Jim E.

2004-06-30

447

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

USGS Publications Warehouse

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

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

2007-01-01

448

77 FR 8325 - Sixth Meeting: RTCA Special Committee 225, Rechargeable Lithium Batteries and Battery Systems...  

Federal Register 2010, 2011, 2012, 2013

...RTCA Special Committee 225, Rechargeable Lithium Batteries and Battery Systems, Small and Medium Size. DATES: The meeting...Review action items. Review of current events with Li-Ion Batteries (15 min). Results of EFB thermal runaway...

2012-02-14

449

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

PubMed Central

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

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

2014-01-01

450

Removal of organic micropollutants in an artificial recharge system  

NASA Astrophysics Data System (ADS)

Emerging contaminants including pharmaceutically active compounds (PhACs), personal care products (PCPs) and pesticides are increasingly being identified in the environment. Emerging pollutants and their transformation products show low concentration in the environment (ng/L), but the effects of the mixtures and lifelong exposure to humans are currently unknown. Many of these contaminants are removed under aerobic conditions in water treatment plants. However, several pharmaceuticals and metabolites present in wastewater are not eliminated by conventional treatment processes. Several lab studies, however, show that the behaviour of many of these micropollutants is affected by the dominant redox conditions. However, data from field experiments are limited and sometimes contradictory. Artificial recharge is a widespread technology to increase the groundwater resources. In this study we propose a design to enhance the natural remediation potential of the aquifer with the installation of a reactive layer at the bottom of the infiltration pond. This layer is a mixture of compost, aquifer material, clay and iron oxide. This layer is intended to provide an extra amount of DOC to the recharge water and to promote biodegradation by means of the development of different redox zones along the travel path through the unsaturated zone and within the aquifer. Moreover, compost, clay and iron oxide of the layer are assumed to increase sorption surfaces for neutral, cationic and anionic compounds, respectively. The infiltration system is sited in Sant Vicen dels Horts (Barcelona, Spain). It consists of a decantation pond, receiving raw water from the Llobregat River (highly affected from treatment plant effluents), and an infiltration pond (5600 m2). The infiltration rate is around 1 m3/m2/day. The system is equipped with a network of piezometers, suction cups and tensiometers. Infiltration periods have been performed before and after the installation of the reactive layer. Water from the Infiltration pond, the unsaturated zone and groundwater have been sampled and analyzed in order to elucidate the effect of the reactive layer. First results of micropollutants under natural conditions show significant removal rates of atenolol and Ibuprofen as well as the recalcitrant behaviour of carbamazepine. Once the layer was installed, carbamazepine concentration in groundwater samples was lower than the concentration in the infiltration water. These preliminary results are promising but, however, they need to be confirmed by further analysis, which will be conducted during the next weeks.

Valhondo, C.; Ndler, K.; Kck-Schulmeyer, M.; Hernandez, M.; Licha, T.; Ayora, C.; Carrera, J.

2012-04-01

451

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

Microsoft Academic Search

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

Petr Novk; Roman Imhof; Otto Haas

1999-01-01

452

Tritium as an indicator of recharge and dispersion in a groundwater system in central Ontario  

Microsoft Academic Search

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

W. D. Robertson; J. A. Cherry

1989-01-01

453

Urban recharge beneath low impact development and effects of climate variability and change  

NASA Astrophysics Data System (ADS)

low impact development (LID) planning and best management practices (BMPs) effects on recharge is important because of the increasing use of LID BMPs to reduce storm water runoff and improve surface-water quality. LID BMPs are microscale, decentralized management techniques such as vegetated systems, pervious pavement, and infiltration trenches to capture, reduce, filter, and slow storm water runoff. Some BMPs may enhance recharge, which has often been considered a secondary management benefit. Here we report results of a field and HYDRUS-2D modeling study in San Francisco, California, USA to quantify urban recharge rates, volumes, and efficiency beneath a LID BMP infiltration trench and irrigated lawn considering historical El Nio/Southern Oscillation (ENSO) variability and future climate change using simulated precipitation from the Geophysical Fluid Dynamic Laboratory (GFDL) A1F1 climate scenario. We find that in situ and modeling methods are complementary, particularly for simulating historical and future recharge scenarios, and the in situ data are critical for accurately estimating recharge under current conditions. Observed (2011-2012) and future (2099-2100) recharge rates beneath the infiltration trench (1750-3710 mm yr-1) were an order of magnitude greater than beneath the irrigated lawn (130-730 mm yr-1). Beneath the infiltration trench, recharge rates ranged from 1390 to 5840 mm yr-1 and averaged 3410 mm yr-1 for El Nio years (1954-2012) and from 1540 to 3330 mm yr-1 and averaged 2430 mm yr-1 for La Nia years. We demonstrate a clear benefit for recharge and local groundwater resources using LID BMPs.

Newcomer, Michelle E.; Gurdak, Jason J.; Sklar, Leonard S.; Nanus, Leora

2014-02-01

454

The Effect of Modeled Recharge Distribution on Simulated Groundwater Availability and Capture.  

PubMed

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

Tillman, F D; Pool, D R; Leake, S A

2014-05-19

455

Groundwater recharge and sustainability in the High Plains aquifer in Kansas, USA  

USGS Publications Warehouse

Sustainable use of groundwater must ensure not only that the future resource is not threatened by overuse, but also that natural environments that depend on the resource, such as stream baseflows, riparian vegetation, aquatic ecosystems, and wetlands are protected. To properly manage groundwater resources, accurate information about the inputs (recharge) and outputs (pumpage and natural discharge) within each groundwater basin is needed so that the long-term behavior of the aquifer and its sustainable yield can be estimated or reassessed. As a first step towards this effort, this work highlights some key groundwater recharge studies in the Kansas High Plains at different scales, such as regional soil-water budget and groundwater modeling studies, county-scale groundwater recharge studies, as well as field-experimental local studies, including some original new findings, with an emphasis on assumptions and limitations as well as on environmental factors affecting recharge processes. The general impact of irrigation and cultivation on recharge is to appreciably increase the amount of recharge, and in many cases to exceed precipitation as the predominant source of recharge. The imbalance between the water input (recharge) to the High Plains aquifer and the output (pumpage and stream baseflows prim