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Sample records for recharge des nappes

  1. Recharge

    SciTech Connect

    Fayer, Michael J.

    2008-01-17

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

  2. Comportement piezometrique des nappes d'alterites en zone intertropicale humide d'altitude (hauts plateaux de Madagascar)

    NASA Astrophysics Data System (ADS)

    Grillot, J. C.; Raunet, M.; Ferry, L.

    1990-12-01

    The behaviour of rice-cultivated peaty valley-bottoms on a weathered crystalline schist, located in a high altitude humid intertropical zone (Madagascar) is under study to define the water and mineral balance of these areas with an economic objective. Analysis of the groundwaters' piezometric level on a reference site allowed the differentiation of inflows and outflows and enabled us to specify the hydraulics of the media. (1) The clay alteration products form a free aquifer broken up by the morphology of the land (valleys, surrounding interfluves); this aquifer discharges by outlets located in the lowlands and thus contributes to the prolonged flooding (nine months a year) of rice-fields; recharge depends on the spatial variability of local precipitation. (2) The granite-gneiss basement constitutes a regional aquifer; the groundwater is semi-confined and outcrops in large valleys with free water-tables draining to the low coastal plains of the island; for the most part its recharge is ensured by discontinuous outcrops (residual ridges); it remains confined for several months after the rainy season. (3) In the lowlands, underlying sands are also water bearing, recharged from superficial flows. The groundwater is confined during the rainy season, which favours ascending flows towards the rice rooting zone.

  3. Analyse des contraintes résiduelles dans les dépôts réalisés par rechargement laser sur alliage d'aluminium

    NASA Astrophysics Data System (ADS)

    Dubourg, L.; Hlawka, F.; Cornet, A.

    2002-07-01

    Superficial characteristics of a substrate, particularly the hardness, the elastic modulus and the wear resistance can be considerably improved by laser cladding. This high energy process causes thermal stresses, leading to residual stresses and substrate distortions. In this study, laser cladding is carried out onto an aluminium alloy with a Nd:YAG laser and a coaxial injection of Al 50Si powders. Residual stresses are determined by X-ray diffraction and by sample strain measurement. The differences of results between these two ways highlight the influence of the heat-affected zone (HAZ) under the coating. These differences can be explained by a model of three blocks: the coating, the HAZ and the substrate. The experimentation shows an optimal treatment speed, leading to maximum compression stresses interesting for the hardness and the wear resistance. Moreover, at a certain fixed speed, the thermal stresses balance each other in the sample and lead to the no-distortion of the substrate. Par la formation d'un dépôt, le rechargement laser permet d'amé liorer les caractéristiques superficielles d'un substrat, en particulier la dureté, le module d'élasticité et la résistance à l'usure. Ce procédé utilisant un faisceau de haute énergie crée dans le matériau traité des contraintes résiduelles d'origine thermique et des déformations du substrat. Dans cet article, le rechargement laser a été réalisé sur un alliage d'aluminium grâce à un laser Nd YAG et une injection coaxiale de poudres Al 50Si. Les contraintes résiduelles ont été étudiées par diffraction des rayons X et par la méthode de la flèche. Les différences de résultats entre ces deux méthodes ont permis de mettre en évidence l'influence de la zone affectée thermique (ZAT) en dessous du dépôt et ont pu être expliquées à l'aide d'un modèle de blocs correspondant respectivement au dépôt, à la ZAT et au substrat. L'expérimentation a révélé, entre autres, une vitesse de traitement optimale qui crée des contraintes résiduelles maximales de compression, bénéfiques pour la dureté et la résistance à l'usure. Il est également apparu que pour une autre vitesse particulière de traitement, les contraintes thermiques s'équilibrent dans le substrat, entrainant une déformation nulle pour un échantillon d'épaisseur donnée.

  4. Apport des isotopes stables dans l'estimation des altitudes de recharge de sources thermales du MarocRecharge altitude estimation of thermal springs using stable isotopes in Morocco

    NASA Astrophysics Data System (ADS)

    Winckel, Anne; Marlin, Christelle; Dever, Laurent; Morel, Jean-Luc; Morabiti, Karim; Makhlouf, Mohamed Ben; Chalouan, Ahmed

    The recharge altitude estimation of thermal springs from northern and eastern Morocco using 18O and 2H contents requires the definition of regional isotopic altitudinal gradients (-0.25‰ for 100 m for the Rif and -0.30‰ for the East) and the calculation of residence time using 14C. The altitudes of emergence vary widely between 170 and 1040 m under the altitude of the recharge areas. The 18O and 2H compositions of palaeowaters ( >10 000 yr BP) indicate two effects, altitude and palaeoclimate. To cite this article: A. Winckel et al., C. R. Geoscience 334 (2002) 469-474.

  5. Estimation of groundwater recharge using the chloride mass-balance method, Pingtung Plain, Taiwan

    NASA Astrophysics Data System (ADS)

    Ting, Cheh-Shyh; Kerh, Tienfuan; Liao, Chiu-Jung

    Due to rapid economic growth in the Pingtung Plain of Taiwan, the use of groundwater resources has changed dramatically. Over-pumping of the groundwater reservoir, which lowers hydraulic heads in the aquifers, is not only affecting the coastal area negatively but has serious consequences for agriculture throughout the plain. In order to determine the safe yield of the aquifer underlying the plain, a reliable estimate of groundwater recharge is desirable. In the present study, for the first time, the chloride mass-balance method is adopted to estimate groundwater recharge in the plain. Four sites in the central part were chosen to facilitate the estimations using the ion-chromatograph and Thiessen polygon-weighting methods. Based on the measured and calculated results, in all sites, including the mountain and river boundaries, recharge to the groundwater is probably 15% of the annual rainfall, excluding recharge from additional irrigation water. This information can improve the accuracy of future groundwater-simulation and management models in the plain. Résumé Du fait de la croissance économique rapide de la plaine de Pingtung à Taiwan, l'utilisation des ressources en eau souterraine s'est considérablement modifié. La surexploitation des aquifères, qui a abaissé le niveau des nappes, n'affecte pas seulement la région côtière, mais a de sérieuses répercutions sur l'agriculture dans toute la plaine. Afin de déterminer les ressources renouvelables de l'aquifère sous la plaine, une estimation précise de la recharge de la nappe est nécessaire. Dans cette étude, le taux de recharge de la nappe a d'abord été estimé au moyen d'un bilan de matière de chlorure. Quatre sites de la partie centrale ont été sélectionnés pour réaliser ces estimations, à l'aide d'un chromatographe ionique et de la méthode des polygones de Thiessen. A partir des résultats mesurés et calculés, à chaque site, et en prenant comme limites les montagnes et les rivières, la recharge de la nappe a étéévaluée à environ 15% des précipitations annuelles, sans tenir compte de la recharge par le retour d'irrigation. Ce résultat doit permettre de tester la précision de la simulation de nappe qui va être faite, ainsi que les modèles de gestion de la plaine. Resumen Debido al rápido crecimiento económico de la zona de la Llanura de Pingtung, Taiwan, el uso de los recursos de agua subterránea ha cambiado radicalmente. La sobreexplotación, con el consiguiente descenso de los niveles piezométricos en los acuíferos, no sólo afecta las áreas costeras, sino que está teniendo consecuencias importantes para la agricultura de la zona. Para determinar la extracción sostenible en el acuífero, es deseable una buena estimación de la recarga. En este estudio se adopta por primera vez el método de balance de cloruros para estimar la recarga en el llano. Se seleccionaron cuatro puntos en la parte central para facilitar las estimaciones mediante los métodos de cromatógrafo iónico y de polígonos de Thiessen. A partir de los resultados medidos y calculados en toda la zona, e incluyendo los contornos de montañas y ríos, la recarga subterránea es de cerca del 15% de la precipitación anual, excluyendo la recarga que se produce por riego adicional. Este dato permitirá mejorar la precisión de los modelos de simulación de flujo y de gestión que se realizarán en el futuro.

  6. Synthese, etude structurale et electrochimique des materiaux d'electrode positive d'oxydes mixtes lithium cobalt nickel oxide (0 /= 1) pour les batteries rechargeables au lithium

    NASA Astrophysics Data System (ADS)

    Grincourt, Yves

    Depuis une dizaine d'annees, on observe un interet grandissant pour les batteries rechargeables au lithium de tension superieure a 4 volts. La commercialisation de ces batteries pour l'electronique grand marche tend de plus en plus a supplanter celle des accumulateurs Ni-Cd et Ni-MH, de tension nominate 1,2 V. Ces batteries au lithium font appel a des materiaux d'electrode positive (cathode a la decharge) du type oxydes mixtes de metaux de transition LiMnO 2, LiMn2O4, LiNiO2 ou LiCoO2. Si le compose LiCoO2 est relativement aise a synthetiser, il n'en demeure pas moins que le cobalt reste un metal plus couteux compare au nickel et au manganese. La synthese de LiNiO2, quart a elle, demeure un probleme du point de vue stoechiometrique. Un defaut de lithium (5 a 10% molaire) conduira a des proprietes electrochimiques mediocres de la batterie. Dans cette etude nous nous proposons donc de preparer par voie humide et par voie seche les materiaux d'electrode positive de la famille LiCoyNi1-yO2 aver (0 ≤ y ≤ 1) et d'etudier en detail l'influence du pourcentage de nickel et de cobalt sur les proprietes electrochimiques des oxydes mixtes Li-Ni-Co. Une des caracteristiques est la morphologie plus fine des poudres de materiaux, observes par microscopie electronique a balayage (MEB). Un traitement thermique a plus basse temperature (750°C) que pour LiCoO2 (850°C) ainsi qu'un leger exces de lithium dans la preparation, ont permis d'aboutir a un materiau de stoechiometrie quasi parfaite. Neanmoins, le role de pilfer joue par 2 a 4% de moles de Ni2+ presents sur les sites lithium, permet de conserver intacte la structure hexagonale de la maille entre deux cycles consecutifs. Afin de mieux comprendre l'influence du vieillissement dune demi-pile Li/LiMeO2 (Me = Ni, Co) a temperature ambiante, des etudes electrochimiques et d'impedance spectroscopique ont ete menees en parallele. Le vieillissement de la cellule s'accompagne seulement dune chute de son potentiel due a son auto-decharge. Neanmoins, il est encore possible de la relancer en cyclage par la suite. Une baisse de la valeur de la resistance totale interfaciale et des frequences au sonnet semble indiquer une modification chimique et/ou structurale des films de passivations, pent-etre due a une transformation de ces films lors du cyclage ou a leur degradation. (Abstract shortened by UMI.)

  7. Global dynamics analysis of nappe oscillation

    NASA Astrophysics Data System (ADS)

    De Rosa, Fortunato; Girfoglio, Michele; de Luca, Luigi

    2014-12-01

    The unsteady global dynamics of a gravitational liquid sheet interacting with a one-sided adjacent air enclosure, typically referred to as nappe oscillation, is addressed, under the assumptions of potential flow and absence of surface tension effects. To the purpose of shedding physical insights, the investigation examines both the dynamics and the energy aspects. An interesting re-formulation of the problem consists of recasting the nappe global behavior as a driven damped spring-mass oscillator, where the inertial effects are linked to the liquid sheet mass and the spring is represented by the equivalent stiffness of the air enclosure acting on the average displacement of the compliant nappe centerline. The investigation is carried out through a modal (i.e., time asymptotic) and a non-modal (i.e., short-time transient) linear approach, which are corroborated by direct numerical simulations of the governing equation. The modal analysis shows that the flow system is characterized by low-frequency and high-frequency oscillations, the former related to the crossing time of the perturbations over the whole domain and the latter related to the spring-mass oscillator. The low-frequency oscillations, observed in real life systems, are produced by the (linear) combination of multiple modes. The non-normality of the operator is responsible for short-time energy amplifications even in asymptotically stable configurations, which are confirmed by numerical simulations and justified by energy budget considerations. Strong analogies with the edge-tone problem are encountered; in particular, the integer-plus-one-quarter resonance criterion is uncovered, where the basic frequency to be multiplied by n + /1 4 is just the one related to the spacing among the imaginary parts of the eigenvalues.

  8. An assessment of recharge estimates from stream and well data and from a coupled surface-water/groundwater model for the des Anglais catchment, Quebec (Canada)

    NASA Astrophysics Data System (ADS)

    Chemingui, Asma; Sulis, Mauro; Paniconi, Claudio

    2015-12-01

    Estimation of groundwater recharge is of critical importance for effective management of freshwater resources. Three common and distinct approaches for calculating recharge rely on techniques of baseflow separation, well hydrograph analysis, and numerical modeling. In this study, these three methods are assessed for a watershed in southwestern Quebec, Canada. A physically based surface-subsurface model provides estimates of spatially distributed recharge; two baseflow separation filters estimate recharge from measured streamflow; and a well hydrograph master recession curve technique calculates recharge from water-table elevation records. The recharge results obtained are in good agreement over the entire catchment, producing an annual aquifer recharge of 10-30 % of rainfall. The annual average estimated across all methods is 200 mm/year. High variability is obtained for the monthly and seasonal recharge patterns (e.g. respectively, 0-30 mm for September and 0-95 mm for the summer), in particular between the baseflow filters and the well hydrograph technique and between the hydrograph technique and the simulated estimates at the observation wells. Recharge occurs predominantly in the spring months for the different approaches, except for the master recession curve method for which the highest recharge estimates are obtained during the summer. The recharge distribution obtained with the model shows that the main recharge area of the aquifer is the Covey Hill region. The use of a fully integrated physically based model enables the construction of an arbitrary number of well hydrographs to enhance the representativity of the master recession curve technique.

  9. Groundwater capture processes under a seasonal variation in natural recharge and discharge

    NASA Astrophysics Data System (ADS)

    Maddock, Thomas, III.; Vionnet, Leticia Beatriz

    "Capture" is the increase in recharge and the decrease in discharge that occurs when pumping is imposed on an aquifer system that was in a previous state of approximate dynamic equilibrium. Regional groundwater models are usually used to calculate capture in a two-step procedure. A steady-state solution provides an initial-head configuration, a set of flows through the boundaries for the modeled region, and the initial basis for the capture calculation. The transient solutions provide the total change in flows through the boundaries. A difference between the transient and steady-state solutions renders the capture calculation. When seasonality is a modeling issue, the use of a single initial hydraulic head and a single set of boundary flows leads to miscalculations of capture. Instead, an initial condition for each season should be used. This approach may be accomplished by determining steady oscillatory solutions, which vary through the seasons but repeat from year to year. A regional groundwater model previously developed for a portion of the San Pedro River basin, Arizona, USA, is modified to illustrate the effect that different initial conditions have on transient solutions and on capture calculations. Résumé Les "prélèvements" sont constitués par l'augmentation de la recharge et par la diminution de l'écoulement qui se produit lorsqu'un pompage est imposéà un système aquifère qui était auparavant dans un état proche de l'équilibre dynamique. Les modèles régionaux de nappe sont en général utilisés pour calculer les prélèvements dans une procédure à deux étapes. Une solution en régime permanent donne la configuration piézométrique initiale, un jeu de conditions aux limites pour la région modélisée et les données de base pour le calcul des prélèvements. Les solutions transitoires donnent les modifications globales des conditions aux limites. Lorsque des variations saisonnières sont produites en sortie du modèle, le recours à une piézométrie initiale unique et à un seul jeu de données de conditions aux limites conduit à un mauvais calcul des prélèvements. Il faut alors utiliser une condition de recharge initiale pour chaque saison. Cette approche peut être réalisée en déterminant des solutions permanentes périodiques, variantes au cours des saisons, mais se répétant d'année en année. Un modèle de nappe régional, précédemment mis au point pour une partie du bassin de la rivière San Pedro (Arizona, États-Unis), a été modifié pour illustrer l'effet de conditions initiales différentes sur des solutions transitoires et sur le calcul des prélèvements. Resumen Se define como "captura" al aumento de recarga y descenso de descarga que tiene lugar cuando se impone un bombeo en un acuífero en estado de equilibrio dinámico. Se suelen utilizar modelos regionales de agua subterránea para calcular la captura en un procedimiento que consta de dos etapas. Una solución en régimen estacionario proporciona la distribución inicial de niveles piezométricos, los flujos a través de los contornos de la región modelada y el punto de partida para el cálculo de la captura. Las soluciones transitorias proporcionan los cambios en los flujos a través de los contornos. La diferencia entre las soluciones estacionaria y transitoria da el valor de la captura. Cuando los cambios estacionales son importantes, la utilización de un único estado inicial de niveles y de flujos en los contornos da lugar a errores en el cálculo de la captura. En este caso debe usarse una condición inicial para cada una de las estaciones. Esto se puede conseguir obteniendo soluciones periódicas estacionarias, que varíen a lo largo de las estaciones, pero que se repitan año a año. Un modelo regional desarrollado previamente para el estudio de una parte de la cuenca del Río San Pedro, en Arizona (EE.UU.) se modificó para ilustrar el efecto que las distintas condiciones iniciales tienen en el cálculo de la captura.

  10. Downstream of downtown: urban wastewater as groundwater recharge

    NASA Astrophysics Data System (ADS)

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

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

  11. Hyperextension in the northern Caledonides: the Gargia nappe in Finnmark

    NASA Astrophysics Data System (ADS)

    Corfu, Fernando; Andersen, Torgeir B.

    2015-04-01

    Hyperextension stretches the lithosphere to the breaking point leading to the exhumation of serpentinized upper mantle peridotites, and the development of sedimentary basins and tectonic melange. The products of such processes are well documented along recent passive margins and in the Alps. Melange defines also a prominent nappe units extending along the southern Scandinavian Caledonides, where it is interpreted as the product of extension during formation of Iapetus (Andersen et al. 2012). In western Finnmark, northern Norway, a melange-type assemblage with km-size serpentinite bodies embedded in various metasedimentary rocks, schists and mylonitic units occurs in the Gargia nappe. The nappe overlies an autochthonous basement suite of Early Paleoproterozoic basalts and associated sedimentary rocks and its Neoproterozic sedimentary cover, including a tillite horizon. The Gargia nappe is itself overlain by the Kalak Nappe Complex, which in this region is composed mainly of psammites, likely deposited around 1000 Ma. The Kalak Nappe Complex contains the record of a multistage tectonic evolution with several episodes of magmatism and metamorphism between 900 and 550 Ma that paleogeographically do not fit the Archean to Paleoproterozoic evolution of the underlying autochthon of the Baltic Shield. Because of this recent new information, the postulation, in past decades, of an origin of the Kalak Nappe Complex from the Baltic margin has been problematic. The presence of exhumed mantle serpentinite bodies in the underlying Gargia Nappe, however, provides evidence for a truly allochthonus nature of the overlying nappes. The serpentinite mega-boudins of the Gargia Nappe are embedded in mica schists, hornblende schists, rare marbles, and mylonitic gneisses. Preliminary U-Pb geochronology indicates that the protoliths of the mylonitic gneisses are about 2830 Ma and probably were derived from the deformed basement gneisses, likely of Archean age, in the nappe. The time of extension is still uncertain and is presently under investigation. Andersen T.B., Corfu F., Labrousse L. and Osmundsen P.T. 2012 Evidence for hyperextension along the pre-Caledonian margin of Baltica. Journal of the Geological Society, London 169: 601-612

  12. The Jotun and related nappe complexes, southern Norway

    NASA Astrophysics Data System (ADS)

    Corfu, F.; Roffeis, C.

    2012-04-01

    The Caledonides in southern Norway have a substrate of autochthonous to parautochthonous metasedimentary rocks overlain by allochthonous crystalline nappe complexes. The Jotun Nappe Complex, the largest of these, is itself composed of several parts with somewhat different histories. The common element linking all the parts is an intense overprint during the Sveconorwegian orogeny, varying in intensity from deformation at relatively low to medium grade metamorphic conditions to high grade metamorphism and local anatexis (Schärer 1980; Lundmark et al. (2007). The Inner Sogn anorthosite complex was emplaced at about 970 Ma (Lundmark and Corfu 2008), but most of the nappe formed between 1700 and 1600 Ma, with local components of 1450 and 1250 Ma, and with locally important felsic dyke complexes intruded in the Mid Silurian (427 Ma) during thrusting. The association of Sveconorwegian gabbro-anorthosite intrusion, high grade metamorphism and Caledonian felsic magmas is also a characteristic of the Lindås Nappe in the Bergen Arc, except that the latter contains Caledonian eclogites which have yet to be observed in the Jotun Nappe Complex. In the northeastern parts of the region, the Jotun Nappe Complex is underlain by the Espedalen Nappe Complex, which also contains an anorthosite massif, but is distinct in terms of primary age, most parts having formed at about 1520 Ma before undergoing Sveconorwegian metamorphism. The western flank of the Jotun Nappe Complex in the Sognefjell region is instead underlain by a highly sheared and distinct suite of 960-950 Ma gabbroic to tonalitic rocks and ca. 1700 Ma orthogneiss. These rocks may link up to the Bergsdalen nappes to the southwest. Another important element of these allochthons is the Hardanger-Ryfylke Nappe Complex, whose major nappe sheet (Kvitenut) compares with the Jotun Nappe Complex in being composed of 1700-1600 Ma orthogneisses severely affected by Sveconorwegian deformation and local anatexis. There is, however, an important distinction in that the Sveconorwegian activity (including granitic magmatism) occurred at 1000 Ma in Kvitenut and Dyrskard (Roffeis et al., this meeting), but later at 950-900 Ma in Jotun and Lindås. The uppermost sheet of the Hardanger-Ryfylke Nappe Complex appears to have a special history which may link it to a higher tectonic level (Upper Allochthon) not present elsewhere in these nappes. In conclusion, most elements of these nappes in the Middle Allochthon in southern Norway are consistent with a pre-Caledonian position at the edge of Baltica, but there are many internal peculiarities which will eventually contribute to constrain more precisely their specific original locations. Lundmark et al. 2007. Precambrian Res 159: 133-154 Lundmark and Corfu 2008. Contrib Mineral Petrol 155: 147-163 Schärer 1980. Earth Planet Sci Lett 49: 205-218

  13. Thermal history of the westernmost Eastern Alps (Penninic Rhenodanubian Flysch nappes, Helvetic nappes, and Subalpine Molasse thrust sheets)

    NASA Astrophysics Data System (ADS)

    Zerlauth, Michael; Bertrand, Audrey; Rantitsch, Gerd; Groß, Doris; Ortner, Hugo; Pomella, Hannah; Fügenschuh, Bernhard

    2015-12-01

    The frontal part of the westernmost Eastern Alps comprises from top to bottom of the Austroalpine and Penninic nappes, Ultrahelvetic slices, and two Helvetic thrust sheets, thrust upon the northern Alpine Molasse Basin. The thermal evolution of the Penninic Rhenodanubian Flysch nappes, the Helvetic nappes, and the allochthonous part of the Alpine Molasse Basin is constrained by vitrinite reflectance measurements and apatite fission track dating and implemented in a tectonic evolution scheme. Within the Helvetic nappes, vitrinite reflectance increases regionally from north to south and stratigraphically from the Campanian-Maastrichtian Wang Formation to the Toarcian Mols Member. Apatite fission track ages from Penninic and Subalpine Molasse units are consistently younger than the deposition age. They indicate therefore a post-depositional thermal overprint exceeding approximately 120 °C, the upper temperature limit of the apatite partial annealing zone. 1D thermal modelling suggests that the Penninic nappes attained deepest burial between the latest Cretaceous and Early Palaeocene with the Penninic basal thrust being located at approximately 8 km in the north compared to approximately 12 km in the south. Deepest burial of the upper Helvetic nappe occurred between the latest Eocene and Early Miocene. Its base was buried down to approximately 10.5 km in the north compared to 11.5 km in the south. Exhumation of the entire nappe stack started in the Early to Middle Miocene. For both Penninic and Helvetic models, a heatflow minimum during the Cenozoic deformation (max. 27-32 mW/m2), followed by an increase from the Middle Miocene onwards (up to 60 mW/m2), was assumed.

  14. Groundwater recharge and chemical evolution in the southern High Plains of Texas, USA

    NASA Astrophysics Data System (ADS)

    Fryar, Alan; Mullican, William; Macko, Stephen

    2001-11-01

    The unconfined High Plains (Ogallala) aquifer is the largest aquifer in the USA and the primary water supply for the semiarid southern High Plains of Texas and New Mexico. Analyses of water and soils northeast of Amarillo, Texas, together with data from other regional studies, indicate that processes during recharge control the composition of unconfined groundwater in the northern half of the southern High Plains. Solute and isotopic data are consistent with a sequence of episodic precipitation, concentration of solutes in upland soils by evapotranspiration, runoff, and infiltration beneath playas and ditches (modified locally by return flow of wastewater and irrigation tailwater). Plausible reactions during recharge include oxidation of organic matter, dissolution and exsolution of CO2, dissolution of CaCO3, silicate weathering, and cation exchange. Si and 14C data suggest leakage from perched aquifers to the High Plains aquifer. Plausible mass-balance models for the High Plains aquifer include scenarios of flow with leakage but not reactions, flow with reactions but not leakage, and flow with neither reactions nor leakage. Mechanisms of recharge and chemical evolution delineated in this study agree with those noted for other aquifers in the south-central and southwestern USA. Résumé. L'aquifère libre des Hautes Plaines (Ogallala) est le plus vaste aquifère des états-Unis et la ressource de base pour l'eau potable de la région semi-aride du sud des Hautes Plaines du Texas et du Nouveau-Mexique. Des analyses de l'eau et des sols prélevés au nord-est d'Amarillo (Texas), associées à des données provenant d'autres études dans cette région, indiquent que des processus intervenant au cours de l'infiltration contrôlent la composition de l'eau de la nappe libre dans la moitié septentrionale du sud des Hautes Plaines. Les données chimiques et isotopiques sont compatibles avec une séquence de précipitation épisodique, avec la reconcentration en solutés dans les sols des hautes terres par évapotranspiration, avec le ruissellement et l'infiltration dans les playas et les fossés (modifiée localement par l'écoulement en retour des eaux usées et des laisses d'irrigation). Des réactions probables intervenant au cours de la recharge sont l'oxydation de la matière organique, la dissolution et le dégazage du CO2, la dissolution du CaCO3, l'altération des silicates et l'échange de cations. Les données concernant Si et 14C laissent penser qu'il existe une drainance descendante à partir d'aquifères perchés vers l'aquifère des Hautes Plaines. Des modèles vraisemblables de bilan de matière pour l'aquifère des Hautes Plaines prennent en compte des scénarios d'écoulement avec drainance mais sans réactions, des écoulements avec réactions mais sans drainance et des écoulements sans réactions ni drainance. Les mécanismes de recharge et d'évolution chimique déterminés dans cette étude sont en accord avec ceux mis en évidence dans d'autres aquifères du centre sud et du sud-ouest des états-Unis. Resumen. El acuífero libre de High Plains (Ogallala) es el mayor de los Estados Unidos y supone la fuente principal de abastecimiento en la región semiárida del sur de High Plains (Texas) y de Nuevo México. Los análisis de agua y suelos realizados al nordeste de Amarillo (Texas), junto con los datos de otros estudios regionales, indican que los procesos que tienen lugar durante la recarga del acuífero controlan la composición de las aguas subterráneas en la mitad septentrional de los High Plains del Sur. Los datos isotópicos y hidroquímicos son coherentes con una secuencia de episodios de precipitación, concentración de solutos en la parte superior del suelo por evapotranspiración, escorrentía, e infiltración a través de 'playas' y zanjas (modificadas localmente por los flujos de retorno de aguas residuales y de excedentes de riego).

  15. Nappe structure in a crustal scale duplex in Swat, Pakistan

    SciTech Connect

    Lawrence, R.D.; Snee, L.W.; Rosenberg, P.S.

    1985-01-01

    In the internal zone of thrust belts of continental collision orogens like the Himalaya metamorphic rocks of deep origin record penetrative ductile deformation. In Swat, Pakistan, this zone between the Indus suture and the sedimentary fold-and-thrust belt is narrower and tectonically simpler than elsewhere along the Himalayan orogenic belt. Here the authors have recognized large overturned, orthogneiss cored nappes of 15 km half wavelength. These are defined by para-amphibolite marker beds found in upright stratigraphic section above and in overturned section below the gneissic cores. They distinguish premetamorphic granite porphyry and tourmaline granite intruded into quartzose metasediments as gneissic cores of the nappes and a surrounding sequence of quartzites, amphibolites, and carbonates that were either deposited unconformably above the cores or premetamorphically thrust over them. Metamorphic isogrades cut across the nappe and /sup 40/Ar//sup 39/Ar hornblende dates indicate that metamorphic culmination occurred around 37-40 Ma at about 550/sup 0/C and at depths of about 20 km. These structures thus appear to predate the recognized age of metamorphism and thrusting of crystalline rocks on the MCT in the central Himalaya. They represent an early deep burial of the leading edge of the Indian shield by ophiolite slabs of oceanic lithosphere and/or the Kohistan island arc. By 30 Ma metamorphic temperatures (/sup 40/Ar//sup 39/Ar muscovite) had dropped to 320/sup 0/C, and the nappes were rising through the crust on underlying thrusts. The entire structure is very similar to that of the internal zone of the Alps, but such features have not previously been described in the Himalaya.

  16. The Ghomarides Nappes, Rif Coastal Range, Morocco: A Variscan chip in the Alpine Belt

    NASA Astrophysics Data System (ADS)

    Chalouan, Ahmed; Michard, André

    1990-12-01

    The Ghomarides nappes are the uppermost basement nappes in the Rifan Alpine belt. Paleozoic rocks constitute the prominent part of these nappes, together with Triassic and younger cover sediments. Four nappes are distinguished, each one with a distinct stratigraphical sequence, especially for the Devonian and Carboniferous periods. Sedimentological and structural arguments plead for an initial location on the northern margin of the African continent. The main folding and metamorphic events are shown to be Eo-Variscan (late Acadian). Tectonic vergence was to the north (present coordinates). Late Variscan (Hercynian) shortening gave upright, NW-SE trending folds. Alpine ductile overprints are scarce except at the base of the lowest nappe where K/Ar phengite ages are about 25 Ma. The Ghomarides nappes correlate with the Malaguides nappes (Betic Cordilleras, southern Spain), the Kabylian (northern Algeria) and Calabrian (southern Italy) Paleozoic nappes, the Tuscan-South-Alpine basement and the Upper Austro-Alpine nappes. The proposed correlations allow us to restaure the southern margin of the Hercynian belt along northwestern Africa.

  17. Dynamics of tectonic nappes: Numerical models and implications for the mechanical behaviour of the lithosphere

    NASA Astrophysics Data System (ADS)

    Markus Schmalholz, Stefan

    2013-04-01

    Nappes and shear zones are common structures in orogenic belts. In the western European Alps many nappes exhibit a considerable internal deformation expressed by structures such as folds or penetrative foliation. Such internal deformation is observed in basement nappes as well as in sedimentary nappes of the Helvetic nappe system. Overthrust nappes such as the Glarus or Diablerets nappe have been displaced on detachment layers (e.g. limestone or shales) and observed structures (e.g. foliation, S-C structure, crystallographic preferred orientation) suggest that a significant amount of the deformation in these layers was effectively ductile. Also, a number of field and modelling studies suggest that many Alpine basement nappes formed as a result of ductile shearing. However, the mechanical processes generating tectonic nappes are still incompletely understood. 2D numerical simulations are performed to investigate the formation of tectonic nappes. The applied numerical algorithm is based on the finite element method. The boundaries between model layers are defined by contour lines containing finite element nodes. A Lagrangian mesh with re-meshing is used. During re-meshing the nodes on the contour lines are not modified so that the boundaries between model units are accurately followed and resolved during the entire large strain deformation. A series of simple systematic simulations with a power-law viscous flow law is performed to investigate the transition between overthrusting and folding. The results are applied to the Helvetic nappe system and show that significant overthrusting is possible for viscous layers. To study the evolution of basement nappes and to quantify the pressure and temperature evolution a more elaborated algorithm with a viscoelasticplastic rheology is applied. The stress is limited by a Mohr-Coulomb failure criterion. Thermo-mechanical coupling by shear heating is considered. The governing partial differential equations are solved numerically in dimensionless form to reduce the number of model parameters. Simulations of 2D lithospheric shortening are performed with a weak circular inclusion in the lower crust to localize the deformation and slightly different temperatures at the left and right half of the lithospheric bottom are applied to generate a small initial asymmetry. During the simulations a shear zone develops around the inclusion and strain is localized on this shear zone due to shear heating. Deviatoric stresses in and around the shear zone can be significantly smaller than pressure deviations from lithostatic values. The results show that significant tectonic overpressures are not necessarily linked to high values of deviatoric stresses. The pressure gradient along the shear zone is a possible driving mechanism for the nappes. The numerical results and the observations in Alpine nappes suggest that the lithosphere behaved dominantly ductile during nappe formation.

  18. Evaluation of scraping treatments to restore initial infiltration capacity of three artificial recharge projects in central Iran

    NASA Astrophysics Data System (ADS)

    Mousavi, Sayed-Farhad; Rezai, Vafa

    A limiting factor in developing artificial recharge of groundwater is clogging of the soil surface and consequent reduction of infiltration rates. In order to evaluate the degree of improving infiltration rates by scraping away various amounts of the upper soil materials, a study was conducted at three artificial recharge sites (Kohrouyeh, Bagh-Sorkh, and Kachak) in Isfahan Province, central Iran. Five treatments (T1-T5) were considered. Infiltration was measured: T1, on deposited sediment layer; T2, after removing the sediments; T3, scraping of sediments and 5cm of soil; T4, scraping of sediments and 10cm of soil; and T5, removing sediments and 15cm of soil. Initial soil-moisture content of the sites ranged from 1.0-2.87% for Kohrouyeh, 1.18-3.47% for Bagh-Sorkh, and 1.89-3.93% for Kachak. The main texture of the soils was sandy loam. Clay particles have penetrated to a depth of more than 40cm in some of the recharge basins. A significant increase in final infiltration rate of T5 as compared to T1 treatment was observed for all recharge sites. The final infiltration rates of T1 and T5 treatments for Kohrouyeh, Bagh-Sorkh, and Kachak sites were 0.35, 7.9; 1.22, 12.3; and 0.93, 6.2cm/h, respectively. The differences between infiltration rates of T2, T3, and T4 treatments were not statistically significant. It is concluded that on average, the infiltration capacity of the untreated recharge facilities have reached 20.3% of the original values, and that scraping the top sediment layer and 15cm of topsoil could restore 68.3% of the initial infiltration capacity. Résumé Un facteur limitant lorsqu'on développe la recharge artificielle d'une nappe est le colmatage de la surface du sol et la réduction concomitante des taux d'infiltration. Afin d'évaluer le degré d'amélioration de l'infiltration en grattant de différentes manières la surface du sol, une étude a été conduite sur trois sites de recharge artificielle (Kohrouyeh, Bagh-Sorkh et Kachak) dans la province d'Ispahan (Iran central). Cinq traitements (T1-T5) ont été testés et l'infiltration a été mesurée: T1, sur une couche de sédiments déposés T2, après enlèvement du sédiment T3, grattage des sédiments et du sol sur 5cm T4, grattage des sédiments et du sol sur 10cm et T5, enlèvement des sédiments et de 15cm de sol. La teneur initiale en eau du sol sur les sites va de 1.0 à 2.87% à Kohrouyeh, 1.18 à 3.47% à Bagh-Sorkh, et 1.89 à 3.93% à Kachak. Les sols sonbt surtout des sols végétaux sableux. Les particules argileuses ont pénétré jusqu'à plus de >40cm de profondeur dans certains bassins de recharge. Un accroissement significatif du taux final d'infiltration de la procédure T5 comparée à T1 a été observée sur tous les sites de recharge. Les taux finaux d'infiltration des procédures T1 et T5 à Kohrouyeh, Bagh-Sorkh et Kachak étaient respectivement 0.35 et 7.9, 1.22 et 12.3, et 0.93 et 6.2cm/h. Les taux d'infiltration des procédures T2, T3 et T4 ne présentaient pas statistiquement de différences significatives. On en conclut donc qu'en moyenne la capacité d'infiltration de la recharge non traitée s'est accrue de 20.3 % par rapport aux valeurs initiales, et que le grattage du sommet du sédiment et du sol sur 15cm peut améliorer 68.3 % de la capacité initiale d'infiltration.

  19. Nappe-Bounding Shear Zones Initiated On Syn-Tectonic, Pegmatite-Filled Extensional Shear Fractures During Deep-Crustal Nappe Flow In A Large Hot Orogen

    NASA Astrophysics Data System (ADS)

    Culshaw, Nicholas; Gerbi, Christopher; Marsh, Jeffrey; Regan, Peter

    2014-05-01

    The Central Gneiss Belt (CGB) of the Proterozoic western Grenville Province is an extensive exposure of the mid-crustal levels (upper amphibolite facies, lesser granulites) of a large hot orogen. Numerical models give a credible prediction of structure and metamorphism accompanying CGB deep-crustal nappe flow and define a temporal framework based on four developmental phases: thickening, heating, nappe-flow and post convergence extensional spreading. These phases are diachronous in direction of orogen propagation and imply a spatial framework: externides (close to orogen-craton boundary) containing moderately inclined thickening and/or extensional structures, and internides containing thickening structures overprinted by sub-horizontal nappe flow structures, which may be locally overprinted by those due to extensional spreading. Although on average of granitoid composition, CGB nappes differ in rheology, varying from fertile and weak (unmetamorphosed before Grenville, meltable) to infertile and strong (metamorphosed at high grade before Grenville, unmeltable) or mixed fertile-infertile protoliths. Deformation style varies from diffuse in fertile nappes, weakened by pervasive melting, to localised in shear zones on boundaries or interiors of infertile nappes. Specifically, in terms of deformation phase and location within the orogen, shear zones occur as: thickening structures of externides, early thickening- and later overprinting nappe-flow structures of infertile internide nappes, and extension-related shear zones in externides and internides. Many of the nappe-flow shear zones of the internides are associated with pegmatites. One example has been recognized of a preserved progression from small-scale fracture arrays to regional shear zone. The sequence is present on a km-scale and initiates in the interior of a nappe of layered granulite with arrays of pegmatite filled extensional-shear fractures (mm to cm width) displaying amphibolized margins. The fracture arrays develop into systems of pegmatite cored amphibolite facies shear zones (cm to dm width) lying within metre-scale corridors of variably retrogressed unsheared layered granulite. The sequence culminates with transposition of the layered protolith within the kilometre-scale amphibolite facies shear zone that forms the base of the granulite nappe. The pegmatitic hydrous magma clearly plays a role in initial crack formation, progressive retrogression and weakening of the granulite but its source remains obscure.

  20. Transition from thin- to thick-skinned tectonics and consequences for nappe formation: numerical simulations and applications to the Helvetic nappe system, Switzerland

    NASA Astrophysics Data System (ADS)

    Bauville, Arthur; Schmalholz, Stefan M.

    2015-04-01

    We use two dimensional numerical simulations to study the deformation style and nappe formation during the compression of basement-cover systems with half-grabens. We perform mechanical simulations with only linear and power-law viscous rheology, and also thermo-mechanical simulations with viscoelastoplastic rheology and temperature-dependent viscosities. The results show that the transition from thin-skinned dominated (i.e. deformation mostly in the cover sediments) to thick-skinned dominated (i.e. similar amount of deformation in basement and sediments) deformation is controlled by two effective viscosity ratios: the ratio of viscosity at the top of basement to viscosity at the bottom of basement, and the ratio of viscosity at the top of the basement to viscosity of the sedimentary cover. A higher basement-internal ratio favors thick-skinned deformation whereas a higher basement-cover ratio favors thin-skinned deformation. The results further show that the sediments initially in the half-graben form fold nappes during a thick-skinned dominated deformation and thrust nappes during a thin-skinned dominated deformation. Simulations with only viscous rheology show the same first-order results as the thermo-mechanical simulations. The results are applied to the Morcles fold nappe (Helvetic nappe system, Switzerland), and a model for the tectonic evolution of this fold nappe is proposed.

  1. Permian age from radiolarites of the Hawasina nappes, Oman Mountains

    NASA Astrophysics Data System (ADS)

    de Wever, Patrick; Bourdillon-de Grissac, Chantal; Bechennec, François

    1988-10-01

    The Hawasina nappes of the Oman Mountains yielded Permian radiolarians from cherts stratigraphically overlying a thick volcanic basement (AI Jil Formation) at the base of the Hamrat Duru Group. This fauna represents the first Permian radiolarians and radiolarites in the central and western Tethyan realm. A Permian age for pelagic sequences within the Hawasina Complex of Oman has major significance for regional paleogeographic reconstruction. A clear differentiation between platform (reefal sediments) and basin (radiolarites) from the base of the Late Permian (255 Ma) is implied. It suggests a flexure of the platform during Permian time; the present date implies that a zone of rifting was already developed adjacent to the northeast Gondwana platform margin during the Late Permian. The Hamrat Duru Basin corresponds to an opening intracontinental rift area (sphenochasm) between Arabia and northeast Gondwana, a reentrant of the paleo-Tethys.

  2. The Pan-African nappe tectonics in the Shackleton Range

    USGS Publications Warehouse

    Buggisch, W.; Kleinschmidt, G.

    2007-01-01

    In memory of Campbell Craddock: When J. Campbell Craddock (1972) published his famous 1:5 000 000 map of the Geology of Antarctica, he established major units such as the East Antarctic Craton, the early Palaeozoic Ross, the Mesozoic Ellsworth, and the Cenozoic Andean orogens. It is already evident from this map, that the strike of the Ellsworth Mountains and the Shackleton Range is perpendicular to palaeo-Pacific and modern Pacific margins. While the Ellsworth-Whitmore block is classified as a rotated terrane, the Ross-aged orogen of the Shackleton Range requires another interpretation. The discovery of extended tectonic nappes with south directed transport in the southern Shackleton Range and west transport in the north established a plate tectonic scenery with a subduction dominated Ross Orogen in the Transantarctic Mountains and a transpressive tectonic regime in the Shackleton Range during the final closing of the Mozambique Ocean.

  3. Transition from thin- to thick-skinned tectonics and consequences for nappe formation: Numerical simulations and applications to the Helvetic nappe system, Switzerland

    NASA Astrophysics Data System (ADS)

    Bauville, Arthur; Schmalholz, Stefan M.

    2015-12-01

    We use two-dimensional numerical simulations to study the deformation style and the formation of nappes during the shortening of basement-cover systems with half-grabens. We perform simulations with only linear and power-law viscous rheology, and also thermo-mechanical simulations with viscoelastoplastic rheology and temperature-dependent viscosities. The accumulated, area-averaged strain is calculated for the sediments, ?s, and for the basement, ?b, to quantify the deformation style. The results show that the transition from thin-skinned dominated (?s/?b > 1) to thick-skinned dominated (?s/?b ? 1) deformation is controlled by two effective viscosity ratios: the ratio of viscosity at the top of the basement to viscosity at the bottom of the basement, and the ratio of viscosity at the top of the basement to viscosity of the sedimentary cover. A higher basement-internal viscosity ratio favors thick-skinned deformation whereas a higher basement-cover viscosity ratio favors thin-skinned deformation. Simulations with only viscous rheology show the same first-order results as the thermo-mechanical simulations. The results further show that fold nappe formation is associated with thick-skinned dominated deformation and thrust nappe formation with thin-skinned dominated deformation. Fold nappes are formed by shearing and extrusion of sediments during the deformation and closure of half-grabens whereas thrust nappes are formed due to the shearing-off of sediments from half-grabens which are nearly undeformed. The results are applied to the Morcles fold nappe and the Helvetic nappe system, Switzerland.

  4. Discovery of microdiamond in the Åreskutan Nappe of the Seve Nappe Complex, overlying the COSC-1 drillhole

    NASA Astrophysics Data System (ADS)

    Klonowska, Iwona; Janák, Marian; Majka, Jarosław; ‎ Froitzheim, Nikolaus; Gee, David G.

    2015-04-01

    The Seve Nappe Complex (SNC) crops out for about 800 km along the Scandian mountain belt in northwestern Sweden. In the central Scandes of Jämtland and Tröndelag, the SNC has been mapped 200 km westards into the hinterland, via the Tömmerås and Trollheimen antiforms into the northern parts of the Western Gneiss Region. The Complex is dominated by psammitic metasediments and amphibolites derived from dolerites, basalts and gabbros (locally ultramafites) comprising an outer continental margin assemblage, inferred to represent the Cryogenian-Ediacaran, extended outer margin of Baltica. Although most of the SNC is in amphibolite facies, eclogites and garnet peridotites are locally preserved both in Sweden and farther west in Trollheimen. More pelitic metasediments occur at higher levels in the Complex and the high grade metamorphism is usually accompanied by partial melting and leucogranites. Isotope dating indicates that HP/UHP metamorphism is of mostly of Ordovician age and related to continent-arc subduction during closure of the Iapetus Ocean. In recent years, closer investigation of the high grade metamorphism has led not only to the identification of UHP assemblages in the eclogites and garnet peridotites (Janák et al. 2013, Klonowska et al. 2014), but also that the host paragneisses contain clear evidence of subduction (Majka et al. 2014), with microdiamond inclusions in garnet. Most recently on Åreskutan (Klonowska et al., this volume), on the mountain top above the COSC-1 drillhole, diamond-bearing gneisses have been found. Garnets in Åreskutan gneisses are characterized by inclusion-rich cores. Graphite, carbonates, quartz and CO2-fluid inclusions together with diamonds and moissanite are concentrated in swarms. Garnets are homogeneous, almandine-rich (Alm65-68Prp26-33Grs3-5Sps2-3). However, the highest grossular content is observed in garnet cores (5mol.%). Phengite is characterized by Si content of 3.19-3.47 apfu. Thermodynamic modelling indicates peak pressure conditions within diamond stability field. To identify diamond and moissanite we used micro-Raman spectroscopy technique. Diamonds range in size from 1μm to 3μm, moissanite grain is 3μm across. Raman peaks assigned to microdiamond vary between 1330 and 1332 cm-1. Additional Raman peaks near 1350, 1580 and 1600 cm-1 show partial transformation of diamond to graphite. Moissanite, the natural form of SiC, exhibits negative crystal shape. Raman peaks assigned to moissanite occur at 969, 799, 783 and 777 cm-1. SEM images show the direct contact of both minerals with garnet. The COSC-1 drillhole, in the footwall of the Åreskutan Nappe, penetrating 2.5 km of the poorly exposed lower parts of the SNC, is known to have a complex Ordovician tectonothermal history, with leucogranites of similar age to those in the Åreskutan Nappe (440 Ma) and also substantially older (470 Ma). No evidence of HP metamorphism has yet been reported. COSC investigations are expected to throw new light on the emplacement of subduction complexes onto adjacent continental platforms. Janák et al. 2013. Gondwana Research, 23, 865-879. Klonowska et al. 2014. Geophysical Research Abstracts, Vol. 16, EGU2014-6440-2. Li et al. 2014. 31st Nordic Geological Winter Meeting, Sweden, 2014, Abstract Volume, p. 116, available online. Majka et al. 2014. Geology, 42, 1107-1110.

  5. Appendix C: Recharge

    SciTech Connect

    Fayer, Michael J.; Keller, Jason M.

    2008-01-17

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

  6. 3D FEM modeling of fold nappe formation in the Western Swiss Alps

    NASA Astrophysics Data System (ADS)

    von Tscharner, M.; Schmalholz, S.

    2012-04-01

    Fold nappes are recumbent folds with amplitudes exceeding 10 km and have been presumably formed by heterogeneous simple shear. They often exhibit a constant sense of shearing and a non-linear increase of shear strain towards their overturned limb. The fold axes of the Morcles fold nappe in western Switzerland plunges to the ENE whereas the fold axes in the more eastern Doldenhorn nappe plunges to the WSW. These opposite plunge directions characterize the Wildstrubel depression (Rawil depression, Ramsay, 1981). The Morcles nappe is mainly the result of layer contraction and shearing (Ramsay, 1981). During the compression the massive limestones were more competent than the surrounding marls and shales, which led to the buckling characteristics of the Morcles nappe, especially in the north-dipping normal limb. There are still no 3D numerical studies which investigate the fundamental dynamics of the formation of the large-scale 3D structure including the Morcles and Doldenhorn fold nappes and the related Wildstrubel depression. Such studies require a numerical algorithm that can accurately track material interfaces for large differences in material properties (e.g. between limestone and shale) and for large deformations. We present a numerical algorithm based on the finite element method (FEM) which can simulate 3D fluid flow for a power-law viscous rheology. Our FEM code combines a numerical marker technique and a deformable Lagrangian mesh with re-meshing (Poliakov and Podladchikov, 1992) and is used to study the formation of 3D fold nappes similar to the ones in the Western Swiss Alps. The numerical method requires the interpolation of material properties to the integration points because the layer interface can lie within a finite element. To guarantee accuracy the number of integration points in the finite elements is increased considerably. The interpolation is only performed during several re-meshing steps when the deformed Lagrangian mesh is too distorted. During the re-meshing the global coordinates of the contour points specifying the interface between different materials remain unchanged and the new local coordinates of the contour points are interpolated from the element nodes of the new mesh. Our new FEM code is tested for large strain density driven diapirism and single-layer folding of power-law viscous layers by comparing numerical results with analytical solutions. Also, the results of the new 3D algorithm are compared with results of existing and tested 2D algorithms for cylindrical folding. We present first results for the formation of fold nappes in 3D. We further present preliminary numerical results for the formation of the Morcles-Doldenhorn fold nappe system.

  7. The Alpine nappe stack in western Austria: A crustal-scale cross-section

    NASA Astrophysics Data System (ADS)

    Pomella, Hannah; Bertrand, Audrey; Ortner, Hugo; Zerlauth, Michael; Fügenschuh, Bernhard

    2013-04-01

    A N-S oriented crustal-scale cross-section was constructed east of the Rhine valley in Vorarlberg, western Austria addressing the central Alps-eastern Alps boundary. The construction was based on published data, surface geology, drillings, as well as on reinterpreted seismic lines. The general architecture of the examined area can be described as a typical foreland fold-and-thrust belt, comprising the tectonic units of the Subalpine Molasse, (Ultra-)Helvetic, Penninic, and Austroalpine nappes. These units overthrusted the autochthonous Molasse along the south-dipping listric Alpine basal thrust. The thermotectonic evolution of this nappe stack is adressed by Bertrand et al. (this session). The Subalpine Molasse is multiply stacked, forming a triangle-zone (Müller et al. 1984). The shortening within the Subalpine Molasse in the cross section has been calculated using the Lower Marine Molasse as a reference and amounts to approx. 46 km, (~70%). Towards east the shortening within the Subalpine Molasse decreases dramatically as shown by Ortner et al. (this session). A well-defined seismic feature in the research area is the European basement together with its autochthonous cover, with a moderate southward dip from about 3500m BSL to approx. 6500m BSL along the ca. 50km long section. Several seismic sections show fault structures offsetting the top of the European basement as well as autochthonous cover. Another discontinuous double reflector that can be identified in several seismic sections is interpreted as the base of the Helvetic nappe complex (approx. at 5000m BSL in the southernmost parts). The internal structure of the Helvetic nappe stack could hardly be resolved. The assumed hinterland dipping duplex-structure of the Helvetic nappes results from surface and borehole-data. However, there are at least two Helvetic nappes needed to fill the available space. The deeper one, termed "Hohenemse nappe" (Wyssling, 1985), is overlain by the superficially exposed "Vorarlberg Säntis nappe". In the southern part of the Vorarlberg Säntis nappe (below the "Bregenzer Wald") we suspect a Dogger basin (cut across by well V-Au1) which is, at least to the east, bordered by steep lateral ramps, accompanied by tear faults in the hanging wall (Ostergunten fault system). References Müller, M., Nieberding, F. and Wanninger, A. (1988). Geologische Rundschau, 77/3, 787-796. Wyssling, G. (1985). Palinspastische Abwicklung der helvetischen Decken von Vorarlberg und Allgäu. - Jb. Geol. B.-A., 127/4, 701-706.

  8. Tectonic nappe emplacement on low-angle shear zones triggered by kinematic strain localization

    NASA Astrophysics Data System (ADS)

    Bauville, Arthur; Schmalholz, Stefan M.

    2015-04-01

    Tectonic nappes such as the ones observed in the Helvetic nappe system (Switzerland) are often emplaced on low angle shear zones. These shear zones are usually between 1-100 m thick and can accommodate displacement of tens, up to hundreds of kilometers. In this contribution we address two questions regarding the emplacement of nappes: (1) how do low angle shear zones form? (2) Which mechanism causes strain to localize at the base of nappes? Generally, the localization of strain can have two different causes: (1) A rheological cause, here termed dynamic strain localization. Thereby, strain in a homogeneous material becomes localized because the material softens in certain regions during the deformation (strain softening) due to processes such as grain size reduction, brittle precursor controlled fluid-rock interaction or shear heating. (2) A structural cause, here termed kinematic strain localization. Thereby, the initial strength of the deformed region is heterogeneous and strain localizes due to initial differences in mechanical strength and/or due to particular geometries. Such localization of strain can occur in linear viscous materials. We use two dimensional numerical simulations to study the emplacement of tectonic nappes over half-graben basins in a compressional wedge. We consider a linear viscous rheology and neglect temperature. The initial model configuration represents a simplified passive margin with half-grabens. We investigate (1) the control of half-graben depth on nappe emplacement and (2) the control of rheological layering in the sediments on strain localization. Results show that the viscosity contrast between basement and sediments, and the geometry of the half-graben triggers the localization of deformation at the rift shoulder of the half graben. Sediments then form tectonic nappes that are emplaced along the basement-cover interface when the topography of the basement is high (horst). The sediments that fill the half-grabens are partly sheared-off the half-graben. The resulting geometry is one where strain is localized in the sediments, forming low angle shear zones. Half-graben depth has only a minor control on strain localization. On the other hand the presence of a stronger upper sedimentary layer (i.e. rheological layering) causes significantly stronger localization of deformation in the lower sedimentary layer. Shear zones at the base of the nappes record shear strain up to 150, i.e., they accommodate ~30 km displacement over a thickness of 200 m. We conclude that kinematic strain localization has a strong control on the formation and orientation of shear zones at the base of tectonic nappes. We suggest that the kinematic strain localization can trigger further strain localization caused by dynamic effects, such as due to grain size reduction or shear heating.

  9. The Alpine nappe stack in western Austria: a crustal-scale cross section

    NASA Astrophysics Data System (ADS)

    Pomella, Hannah; Ortner, Hugo; Zerlauth, Michael; Fügenschuh, Bernhard

    2015-04-01

    Based on an N-S-oriented crustal-scale cross section running east of the Rhine Valley in Vorarlberg, western Austria, we address the Alpine nappe stack and discuss the boundary between Central and Eastern Alps. For our cross section, we used surface geology, drillings and reinterpreted seismic lines, together with published sections. The general architecture of the examined area can be described as a typical foreland fold-and-thrust belt, comprising the tectonic units of the Subalpine Molasse, (Ultra-)Helvetic, Penninic and Austroalpine nappes. These units overthrusted the autochthonous Molasse along the south-dipping listric Alpine basal thrust. The European Basement, together with its autochthonous cover, dips gently towards the south and is dissected by normal faults and trough structures. The seismic data clearly show an offset not only of the top of the European Basement, but also of the Mesozoic cover and the Lower Marine Molasse. This indicates an activity of the structures as normal faults after the sedimentation of the Lower Marine Molasse. The Subalpine Molasse is multiply stacked, forming a triangle zone at the boundary with the foreland Molasse. The shortening within the Subalpine Molasse amounts to approximately 45 km (~67 %), as deduced from our cross section with the Lower Marine Molasse as a reference. The hinterland-dipping duplex structure of the Helvetic nappes is deduced from surface and borehole data. There are at least two Helvetic nappes needed to fill the available space between the Molasse below and the Northpenninic above. This is in line with the westerly located NRP20-East transect (Schmid et al., Tectonics 15(5):1047-1048, 1996; Schmid et al., The TRANSMED Atlas: the Mediterranean Region from Crust to Mantle, 2004), where the two Helvetic nappes are separated by the Säntis thrust. Yet in contrast to the Helvetic nappes in the NRP20-East transect, both of our Helvetic nappes comprise Cretaceous and Jurassic strata. This change is explained by an eastward down-stepping of the Säntis thrust along a pre-existing, approximately N-S striking lateral ramp bounding an inverted Jurassic graben structure below the Rhine Valley. This causes the Säntis thrust to detach the base Cretaceous west of the Rhine Valley and the base Jurassic units east of it. This graben-controlled change in detachment level leads to the formation of quite different nappe stacks on either side of the Rhine Valley and a "fault-controlled" appearance of the boundary between the Central and Eastern Alps.

  10. Upper crustal deformation in continent-continent collision: A case study from the Bernard nappe complex (Valais, Switzerland)

    NASA Astrophysics Data System (ADS)

    Scheiber, Thomas; Adrian Pfiffner, O.; Schreurs, Guido

    2013-09-01

    Penninic nappes in the Swiss Alps formed during continental collision between the Adriatic and European plates in Cenozoic times. Although intensely studied, the finite geometry of the basement-bearing Penninic nappes in western Switzerland has remained a matter of debate for decades (e.g., "Siviez-Mischabel dilemma") and the paleogeographic origin of various nappes has been disputed. Here, we present new structural data for the central part of the Penninic Bernard nappe complex, which contains pre-Permian basement and Permo-Mesozoic metasedimentary units. Our lithological and structural observations indicate that the discrepancy between the different structural models proposed for the Bernard nappe complex can be explained by a lateral discontinuity. In the west, the presence of a Permian graben caused complex isoclinal folding, whereas in the east, the absence of such a graben resulted mainly in imbricate thrusting. The overall geometry of the Bernard nappe complex is the result of three main deformation phases: (1) detachment of Mesozoic cover sediments along Triassic evaporites (Evolène phase) during the early stages of collision, (2) Eocene top-to-the-N(NW) nappe stacking (Anniviers phase), and (3) subsequent backfolding and backshearing (Mischabel phase). The southward localized backshearing is key to understand the structural position and paleogeographic origin of units, such as the Frilihorn and Cimes Blanches "nappes" and the Antrona ophiolites. Based on these observations, we present a new tectonic model for the entire Penninic region of western Switzerland and discuss this model in terms of continental collision zone processes.

  11. Artificial recharge of groundwater

    SciTech Connect

    Asano, T.

    1985-01-01

    The vast underground reservoirs formed by aquifers constitute invaluable water supply sources as well as water storage facilities. Because natural replenishment of the supply occurs very slowly, continued excessive exploitation of it causes groundwater levels to decline with time. If not corrected this leads to an eventual depletion of a valuable natural resource. To prevent mining and groundwater pollution, the artificial recharge of groundwater basins is becoming increasingly important in groundwater management as a way to increase this natural supply of water. Artificial recharge can reduce, stop, and even reverse declining levels of groundwater. In addition, it can protect underground freshwater in coastal aquifers against salt-water intrusion from the ocean, and can be used to store surface and reclaimed water for future use. This book is a treatise of the artificial recharge of groundwater, with particular emphasis on recharge with reclaimed municipal wastewater.

  12. Estimating groundwater recharge

    USGS Publications Warehouse

    Stonestrom, David A.

    2011-01-01

    Groundwater recharge is the entry of fresh water into the saturated portion of the subsurface part of the hydrologic cycle, the modifier "saturated" indicating that the pressure of the pore water is greater than atmospheric.

  13. Provenance and tectonic setting of the external nappe of the Southern Brasília Orogen

    NASA Astrophysics Data System (ADS)

    Westin, Alice; Campos Neto, Mario da Costa

    2013-12-01

    The Brasília Orogen, located on the western and southern margins of the São Francisco Craton, corresponds to a horizontal nappe stack that was regionally transported eastward during the collision between the Paranapanema and Central Goiás blocks and the Sanfranciscana Plate in the Ediacaran Period.

  14. Aalenian-Early Bathonian (Middle Jurassic) radiolarian assemblages in the Tavas nappe within Lycian nappes in the western Taurides (SW Turkey): The first dating of carbonate platform drowning

    NASA Astrophysics Data System (ADS)

    Soycan, Havva; Erdoğan, Kemal; Konak, Neşat

    2015-05-01

    Stratigraphic sections (Kizilca and Kizilca North) in the Tavas nappe, western Taurides, Turkey records the event of carbonate platform drowning in the western Tethyan realm. Our detailed biostratigraphic study of radiolarians and other microfossils places the important temporal constraints on this event and indicates that drowning occured in the geochronological interval from Early Jurassic (Hettangian-Sinemurian) through to Middle Jurassic (early Bathonian). The basal part of the Kizilca section is represented by platform carbonates with abundant benthic foraminifera and algae of Hettangian-Sinemurian to Pliensbachian age. Toward the upper part of the section, the occurrence of brecciated limestones with some ammonites and belemnites reveals that the drowning event began in the Pliensbachian. The first radiolarian assemblages of early-middle to late Aalenian age were obtained from the overlying units characterized by pelagic limestones and chert alternation. Just after the subsidence of the platform, ribbon chert sedimentation began in the late Aalenian, as indicated by the radiolarians. Successively, early-late Bajocian and latest Bajocian-early Bathonian radiolarian assemblages were obtained from overlying chert with mudstone-silicified mudstones. Similar to that observed in the Kizilca section, the Kizilca North section include successively pelagic limestones, pelagic limestone-chert alternation and chert-mudstone alternation of late Aalenian to early-middle Bajocian age according to radiolarian biostratigraphy. All of these observations indicate that a continuous stratigraphy recorded the drowning event without a large gap from Hettangian-Sinemurian to early Bathonian in the Tavas nappe. This drowning event has close similarities with coeval events in other Tethyan realms in terms of mechanism, facies characteristics and fossil assemblages. Therefore, this study can aid correlation studies of the Tavas nappe with the Jurassic paleogeography worldwide.

  15. [F. C. NAPP andJ. G. MENDEL a contribution to the prehistory ofMENDEL's experiments].

    PubMed

    Weiling, F

    1968-04-01

    On the centenary of the death ofF. C. NAPP (22. 7. 1867), abbot of the St. Thomas-monastery of Old-Brünn, who admittedJ. G. MENDEL in his convent, enabled him to study natural science and to carry out his experiments, and on the centenary of the election ofMENDEL to succeedNAPP as abbot (31. 3. 1868), we take note of the relationship between these two men as it concerns the discoveries ofMENDEL. Following a short biography ofNAPP we appreciate his service to agriculture and its basic sciences. We find a close connection between the scientific work ofMENDEL andNAPP in meteorology and bee keeping. PMID:24442214

  16. Rôle des héritages latéritiques et du niveau des nappes dans l'évolution des modelés et des sols en zone intertropicale forestière humide

    NASA Astrophysics Data System (ADS)

    Bitom, Dieudonné; Volkoff, Boris; Beauvais, Anicet; Seyler, Frédérique; Ndjigui, Paul-Désiré

    2004-10-01

    Analysis of landscapes and soil covers from the outer to the inner part of a 75 km×60 km watershed in the South-Cameroon rainforest zone, characterized by important remnants of inherited ferricretes and stable hydrostatic base levels, indicates that the development of present landforms has not involved significant erosion by slope retreat because of the relative preservation of downslope residual ferricrete and that soil covers have vertically decayed under in situ geochemical process. To cite this article: D. Bitom et al., C. R. Geoscience 336 (2004).

  17. Rechargeable Aqueous Microdroplet.

    PubMed

    Phan, Chi M

    2014-04-17

    Directional and controllable transportation of microdroplets is critical for emerging micro- and nanotechnology, in which the conventional mechanical energy generation is not applicable. This Letter shows that an aqueous microdroplet can be charged for controlled motion in electrostatic potential, which was created by differentiating pH, between two oil/water interfaces. The directional motion of the droplet, <100 ?m in diameter, was obtained with a constant velocity of ?1 mm/s. The force analysis showed that the droplet surface was charged and recharged oppositely by ion transfer through interfacial layers, without significant mass transfer. The charging and recharging cycles were recorded continuously with a single droplet over 100 times. The energy for motion was generated from pH neutralization, which is the simplest aqueous reaction. This is the first time that the phenomenon is reported. The phenomenon can be employed as an efficient and robust method to convert chemical to mechanical energy for miniaturized devices and microprocesses. PMID:26269994

  18. Rechargeable Magnesium Power Cells

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

  19. REMOTELY RECHARGEABLE EPD

    SciTech Connect

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

    2007-11-13

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

  20. Advanced Small Rechargeable Batteries

    NASA Technical Reports Server (NTRS)

    Halpert, Gerald

    1989-01-01

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

  1. Recharge into a shingle beach

    NASA Astrophysics Data System (ADS)

    Keating, T.

    1984-04-01

    Traditionally, groundwater recharge in the U.K. has been calculated by the Penman method on a monthly basis, using values of potential evaporation derived from averaged meteorological data and monthly totals of rainfall. Recent work by K.W.F. Howard and J.W. Lloyd has shown that these monthly totals considerably underestimate recharge calculated over shorter time periods and they suggested that 1-day, or at worst, 10-day intervals should be used. In this paper field experiments to measure recharge into a shingle beach are reported. These experiments were made with a lysimeter over a 6-yr. period and have shown that recharge into the shingle occurs whenever significant precipitation occurs, even during the summer months. The Penman model is shown to be unrealistic for estimating recharge into such a beach and an alternative model for calculating recharge is proposed. This model is shown to yield good results.

  2. Exhumation of an eclogite terrane as a hot migmatitic nappe, Sveconorwegian orogen

    NASA Astrophysics Data System (ADS)

    Möller, Charlotte; Andersson, Jenny; Dyck, Brendan; Antal Lundin, Ildiko

    2015-06-01

    We demonstrate a case of eclogite exhumation in a partially molten, low-viscosity fold nappe within high-grade metamorphosed crust in the Eastern Segment of the Sveconorwegian orogen. The nappe formed during tectonic extrusion, melt-weakening assisted exhumation and foreland-directed translation of eclogitized crust, and stalled at 35-40 km depth within the collisional belt. The eclogites are structurally restricted to a regional recumbent fold in which stromatic orthogneiss with pods of amphibolitized eclogite make up the core. High-temperature mylonitic gneiss with remnants of kyanite eclogite (P > 15 kbar) composes a basal shear zone 50 km long and < 4 km wide. Heterogeneously sheared and partly migmatized augen gneiss forms a tectonostratigraphic marker in front of and beneath the nappe, and is in turn structurally enveloped by a composite sequence of orthogneisses and metabasites. The entire tectonostratigraphic pile underwent near-pervasive deformation and recrystallization under high-pressure granulite and upper amphibolite conditions. U-Pb SIMS metamorphic zircon ages of eclogite and stromatic orthogneiss constrain the time of eclogitization at 988 ± 6 Ma and 978 ± 7 Ma. Migmatization, concomitant deformation, and exhumation are dated at 976 ± 6 Ma, and crystallization of post-kinematic melt at 956 ± 7 Ma. Orthogneiss protoliths are dated at 1733 ± 11 and 1677 ± 10 Ma (stromatic gneiss) and 1388 ± 7 Ma (augen gneiss in footwall), demonstrating origins indigenous to the Eastern Segment. Eclogitization and exhumation were coeval with the Rigolet phase of the Grenvillian orogeny, reflecting the late stage of continental collision during construction of the supercontinent Rodinia.

  3. Detrital zircon data support a Timanian origin for the Kalak Nappe Complex, North Norwegian Caledonides

    NASA Astrophysics Data System (ADS)

    Andresen, Arild; Agyei-Dwarko, Nana; Steltenpohl, Mark

    2014-05-01

    Detrital zircon data support a Timanian origin for the Kalak Nappe Complex, North Norwegian Caledonides. Arild Andresen, Nana Yaw Agyei-Dwarko & Mark G. Steltenpohl The origin of the Kalak Nappe Complex (KNC) in the Arctic Caledonides of Norway is historically enigmatic. Psammitic rocks of the KNC traditionally are thought to have been derived from the thinned, rifted margin of western Baltica. Recently, it has been proposed that U-Pb ages on detrital zircon and on magmatic zircon from the many intrusives present in KNC suggest derivation from Laurentian (Kirkland et al. 2007) and peri-Gondwanan (Corfu et al. 2011) realms. In this contribution we argue for a third alternative. Our LA-ICP-MS U-Pb ages on detrital zircon from the Ediacaran and Lower Paleozoic deposits (Dividal Group) in northern Scandinavia indicate that their source region was the Timanian Orogen, formed along Baltica`s northeastern margin in the Late Neoproterozoic. A large proportion of the detrital zircon grains from the Ediacaran-Cambrian deposits range in age between c. 1.7 and 1.0 Ga, but a distinct population of c. 0.57 Ga old-detrital zircon is also present in several samples. The source areas for these Late Paleoproterozoic and younger zircons are unknown from northeastern Fennoscandia, but are, however, known from basement rocks (Timanides) below the Pechora Basin in NW Russia and thus is a fingerprint for sediments derived from the Timanides. Psammitic units of the allochthonous Kalak Nappe Complex (KNC) have zircon-age populations similar to those from the Dividal Group with the exception of the 0.57 Ga zircons. If, however, the detrital zircon dates from the KNC are mixed with detrital zircons from the c. 0.57 Ga Sørøy Igneous Complex, then an almost identical zircon age population should be expected. Instead of arguing for a Laurentian or peri-Gondwana origin of KNC, as some authors do, we prefer to link the KNC to the Timanides, preferentially the northwestern part of the present exposed part of the Timanides. Incorporation of the KNC into the Scandinavian Caledonides can thus be explained by oblique rifting (transtension) between Baltica and the remaining Rodinia in the Cryogenian, followed by emplacement of KNC as a series of nappes during collision between Baltica and Laurentia in the Late Silurian-Early Silurian.

  4. Hot granulite nappes — Tectonic styles and thermal evolution of the Proterozoic granulite belts in East Africa

    NASA Astrophysics Data System (ADS)

    Fritz, Harald; Tenczer, Veronika; Hauzenberger, Christoph; Wallbrecher, Eckart; Muhongo, Sospeter

    2009-11-01

    A section through the Neoproterozoic Mozambique Belt of Tanzania exposes western foreland (Archaean Tanzania Craton and Palaeoproterozoic Usagaran Belt), marginal (Western Granulites) and eastern, internal (Eastern Granulites) portions of the orogen. The assembly of granulite nappes at ca. 620 Ma displays westward emplacement along an eastward deepening basal decollement and forward propagation of thrusts, climbing from the deep crust to the surface. This goes along with eastward increase of syntectonic temperatures, derived from prevalent deformation mechanisms, and eastward decrease of the kinematic vorticity number. Distinctly different pressure - temperature paths with a branch of isothermal decompression (ITD) in Western Granulites and isobaric cooling (IBC) in Eastern Granulites reflect residence times of rocks within lower crustal levels. Western Granulites, exhumed rapidly at the orogen margin, display ITD and non-coaxial fabrics. Eastern Granulites in the internal orogen portions escaped from rapid exhumation and show IBC and co-axial flow fabrics. The vertical variation of structural elements, i.e. basement — cover relations within the Eastern Granulites, shows decoupling between lower and middle crust with horizontal west — east stretching in the basement and horizontal west — east shortening in the cover. A model of hot fold nappes [Beaumont, C., Nguyen, M.H., Jamieson, R.A., Ellis, S., 2006. Crustal flow modes in large hot orogens. In: Law, R.D., Searle, M.P., Godin, L., (eds). Channel Flow, Ductile Extrusion and Exhumation in Continental Collision Zones. Geological Society, London, Special Publications. vol. 268, 91-145] is adopted to explain flow diversity in the deep crust. The lower crust represented by Eastern Granulite basement flowed coaxially outwards (westward) in response to thickened crust and elevated gravitational forces, supported by a melt-weakened, viscous channel at the crustal base. Horizontal flow with rates faster than thermal equilibration gave rise to isobaric cooling. Simultaneously the mid crust (Eastern Granulite cover) was shortened when hot fold nappes moved along upward climbing thrust planes. Western Granulites preserved isothermal decompression through exhumation by thrusting and coeval erosion at the orogen front. Two different styles define the Neoproterozoic East African Orogen between northern Egypt and southern Mozambique. The Arabian Nubian Shield in the north is classified as small and cold orogen in which thin — skinned thrusting was associated with lateral extrusion. The Central Mozambique Belt in Tanzania/Southern Kenya is classified as large and hot orogen characterized by thick-skinned thrusting and assembly of large granulite nappes.

  5. FLUIDIC: Metal Air Recharged

    ScienceCinema

    Friesen, Cody

    2014-04-02

    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.

  6. FLUIDIC: Metal Air Recharged

    SciTech Connect

    Friesen, Cody

    2014-03-07

    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.

  7. A Sveconorwegian terrane boundary in the Caledonian Hardanger-Ryfylke Nappe Complex: the lost link between Telemarkia and the Western Gneiss Region?

    NASA Astrophysics Data System (ADS)

    Roffeis, Cornelia; Corfu, Fernando; Gabrielsen, Roy

    2013-04-01

    Magmatic and metamorphic events in two of the nappes of the Hardanger-Ryfylke Nappe Complex in the Caledonides in SW-Norway, and in the intervening thrust zone, have been investigated by means of ID-TIMS U-Pb zircon and titanite data. Orthogneiss protoliths in the upper Kvitenut nappe are dated at 1615 ± 6 Ma, showing analogies to the Gothian terrane, including the Western Gneiss Region. By contrast, the Dyrskard nappe is composed of metasedimentary rocks and metarhyolites with a 1508 ± 4 Ma extrusive age and shows an affinity to rocks of the Telemarkia terranes. We argue that the time of thrusting and juxtaposition of the two nappes along the shear zone is constrained by the age of 999 ± 5 Ma of a syndeformational granite body and co-genetic pegmatitic leucosomes, with late Sveconorwegian movements and fluid activity being recorded by titanite at 924 ± 6 Ma. Both nappes behaved as one block during the Silurian emplacement in the Caledonian nappe stack, sharing a 434 ± 1 Ma metamorphic peak and later overprints, as young as 414 ± 2 Ma, related to retrogression. The distinct origin and Sveconorwegian age of coupling of the Dyrskard and the Kvitenut nappes suggest that, in their pre-Caledonian location to the west-northwest, they represent the now hidden boundary zone between the Western Gneiss Region and Telemarkia.

  8. Dual-porosity modeling of groundwater recharge: testing a quick calibration using in situ moisture measurements, Areuse River Delta, Switzerland

    NASA Astrophysics Data System (ADS)

    Alaoui, Abdallah; Eugster, Werner

    A simple method for calibrating the dual-porosity MACRO model via in situ TDR measurements during a brief infiltration run (2.8 h) is proposed with the aim of estimating local groundwater recharge (GR). The recharge was modeled firstly by considering the entire 3 m of unsaturated soil, and secondly by considering only the topsoil to the zero-flux plane (0-0.70 m). The modeled recharge was compared against the GR obtained from field measurements. Measured GR was 313 mm during a 1-year period (15 October 1990-15 October 1991). The best simulation results were obtained when considering the entire unsaturated soil under equilibrium conditions excluding the macropore flow effect (330 mm), whereas under non-equilibrium conditions GR was overestimated (378 mm). Sensitivity analyses showed that the investigation of the topsoil is sufficient in estimating local GR in this case, since the water stored below this depth appears to be below the typical rooting depth of the vegetation and is not available for evapotranspiration. The modeled recharge under equilibrium conditions for the 0.7-m-topsoil layer was found to be 364 mm, which is in acceptable agreement with measurements. Une méthode simple pour la calibration du modèle à double porosité MACRO par des mesures TDR in situ durant un bref essai d'infiltration (2.8 h) a été proposée pour l'estimation locale de la recharge de la nappe (RN). La RN a été d'abord simulée en tenant compte de toute la zone non saturée (3 m) et ensuite, en considérant uniquement la couverture du sol entre zéro et le plan du flux nul (0.70 m). La RN simulée a été comparée à la RN observée. La RN mesurée durant une année (15 octobre 1990-15 octobre 1991) était de 313 mm. Les meilleures simulations ont été obtenues en tenant compte de toute la zone non saturée sous les conditions d'équilibre excluant le flux préférentiel (330 mm). Sous les conditions de non équilibre, la RN a été surestimée (378 mm). Les analyses de sensitivité ont montré que l'investigation de la couverture du sol est suffisante pour l'estimation locale de la RN du fait que l'eau traversant le plan du flux nul se trouverait sous la zone des racines et échapperait à l'évapotranspiration. La RN simulée sur les 0.70 m du sol sous les conditions d'équilibre était de 364 mm, ce qui est comparable aux mesures. Se propone un método sencillo para calibrar el modelo de doble porosidad "MACRO" mediante medidas in-situ obtenidas por TDR durante un breve ensayo de infiltración (2,8 horas), con el objetivo de estimar la recarga local al acuífero. Ésta ha sido modelada de dos formas: considerando los 3 m de suelo no saturado y empleando sólo desde la capa superior hasta el plano de flujo nulo (de 0 a 0,70 m). Se compara la recarga modelada con la recarga local medida en campo, la cual fue de 313 mm durante un ciclo anual (del 15 de octubre de 1990 al 15 de octubre de 1991). Las mejores simulaciones corresponden a la hipótesis de columna entera no saturada en condiciones de equilibrio, excluyendo el efecto de macroporos (valor de 330 mm), mientras que el resultado obtenido para condiciones de no equilibrio en la recarga local está sobreestimado (378 mm). Los análisis de sensibilidad muestran que la investigación del horizonte superior del suelo es suficiente para estimar la recarga local en este caso, ya que el agua almacenada por debajo de esta profundidad parece estar fuera del alcance típico de las raíces de la vegetación y no puede ser evapotranspirada. La recarga modelada en condiciones de equilibrio para la capa superior de 0,70 m de espesor es de 364 mm, valor aceptable respecto a las medidas.

  9. Syn-sedimentary tectonics in the Cretaceous succession of the Wildhorn nappe (SW Switzerland)

    NASA Astrophysics Data System (ADS)

    Cardello, G. L.; Mancktelow, N. S.

    2012-04-01

    During Early Cretaceous to Early Tertiary times, the area of the future Helvetic Nappes was part of a large ramp-type depositional system on the European margin, in which the area of the Wildhorn nappe was transitional to the more distal and relatively deeper Ultra-Helvetic basin. The Wildhorn nappe includes a late Cretaceous succession bearing clear evidence for post-breakup extensional tectonics such as: synsedimentary geometries related to well oriented, parallel and spaced NE-striking faults; sedimentary dykes; lateral variations in the thickness and facies of formations; anomalous and discordant contacts corresponding to paleoescarpments; and slump folds. This field evidence indicates an important Late Cretaceous extensional tectonic event that affects the older Jurassic passive margin sequence. This process cannot be related to partial or local gravitational collapse, being the faults cross-cut suitable candidates for preferential gliding (e.g. the thick succession of Lower Cretaceous shales). Until now, the regional importance and magnitude of this late Cretaceous extension was not recognized in this part of the Alps. During the Cretaceous, this transitional area experienced three tectonic and sedimentary stages. (1) Post- Cenomanian disruption and exhumation of the Schrattenkalk platform was related to distribute normal faulting, which contributed to the initiation of karst erosion on the topographic highs and sedimentation in the lower parts. (2) During the Campanian and following a marine transgression, the area experienced more localized normal faulting accompanied by subsidence and slope instability directed toward the fault-scarps. A transition from distributed to more localized faulting is observed, related to a final stage in the evolution of the Cretaceous extensional process. The facies and thickness of subsequent post-Campanian sediments reflect a passive adaption to the pre-existing topography of the sea floor, established during the earlier tectonic movements. (3) Post-Maastrichtian north-directed tilting and erosion were caused by normal reactivation of a few main faults. During Eocene-Oligocene, mixed siliciclastic and calcareous deposits passively filled the rejuvenated topography and sealed the fault scarps. The first two stages can therefore be related to widespread post-breakup extension affecting the Mediterranean Tethys during the Late Cretaceous, whereas the later Early Tertiary event can be associated with pre-orogenic flexure of the Alpine foreland.

  10. Thermally-Rechargeable Electrochemical Cell

    NASA Technical Reports Server (NTRS)

    Richter, R.

    1985-01-01

    Proposed liquid-sodium/sulfur electrochemical cell recharged by heat, rather than electric generator. Concept suitable for energy storage for utilites, mobile electronic equipment, and solar thermoelectric power systems. Sodium ions driven across membrane with aid of temperature differential.

  11. Metamorphic sole genesis at the base of ophiolite nappes: Insights from numerical models

    NASA Astrophysics Data System (ADS)

    Yamato, Philippe; Agard, Philippe; Duretz, Thibault

    2015-04-01

    Obduction emplaces oceanic lithosphere on top of continental lithosphere. Although a number of studies have focused on this enigmatic process, the initial stages of obduction remain poorly understood. Field, petrological, and geochronological data reveal that during the first stages of the obduction (i.e., during the first 1-2 Myrs) a HT-LP metamorphic sole (~700-800 ° C and ~1 GPa) is systematically welded at the base of ophiolite nappes. However, the reason why such welding of the ophiolite soles occurs at these particular P-T conditions, and only at the onset of obduction, is still an open issue. The aim of this study is to explore the conditions required to explain the genesis of metamorphic soles. For this, we employ two-dimensional numerical modelling, constrained by the wealth of available data from the Oman ophiolite. We first present a thermo-kinematic model in which the velocity field is prescribed in order to simulate obduction initiation. The heat advection-diffusion equation is solved at each time step. The model is intentionally kept simple in order to control each parameter (e.g., convergence rate, dip angle, thermal age) and to test its influence on the resulting P-T conditions obtained through time along the obduction interface. Results show that the key factor allowing the formation of metamorphic soles is the age of the oceanic lithosphere involved. Moreover, we speculate that the reason why metamorphic soles are always welded at the same P-T conditions is due to the fact that, at these particular conditions, strength jumps occur within the oceanic lithosphere. These jumps lead to changes in strain localisation and allow the spalling of oceanic crust and its juxtaposition to the ophiolite nappe. This hypothesis is further tested using thermo-mechanical models in which the obduction initiates dynamically (only initial and boundary conditions are prescribed). The interplay between the temperature evolution and the mechanical behaviour is then discussed.

  12. Functional materials for rechargeable batteries.

    PubMed

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

    2011-04-19

    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

  13. Origine des nitrates dans les nappes de fissures de la zone tropicale humide — Exemple de la Côte d'Ivoire

    NASA Astrophysics Data System (ADS)

    Faillat, Jean-Pierre

    1990-02-01

    High nitrate contents (up to 200 mg l -1) were observed in a sample of 230 tubewells reaching fissure groundwater beneath thick layers of weathered and decayed rock, in a humid tropical zone with annual rainfall of over 1000 mm. Examination and comparison of the regions studied led to envisaging two possible sources of the nitrates: first, classic domestic pollution, and second the leaching of the soil and rotting plant debris after local deforestation when villages or crops were established. An attempt was made to distinguish between the two sources by using 15N-NO 3. The results were rendered uncertain by the probable involvement of natural denitrification. Nevertheless, this approach provides arguments in support of nitrates originating in processes connected with deforestation.

  14. Organic facies characteristics of the Carboniferous Pamucakyayla Formation, western Taurus, Antalya Nappes, Kemer (Antalya/Turkey)

    NASA Astrophysics Data System (ADS)

    Bertan Gulludag, Cevdet; Altunsoy, Mehmet; Ozcelik, Orhan

    2015-04-01

    The study area is located in the western part of the Taurus Belt (SW Turkey). This region exhibits a complex structure involving two autochthonous units surrounded and imbricated with three allochthonous complexes. Antalya Nappes is a complex tectonic imbricate structure including sedimantary and ultrabasic rocks. In this study, organic facies characteristics of Carboniferous coaly units in the Pamucakyayla region (Kemer, Antalya-Turkey) were examined. The Carboniferous Pamucakyayla Formation, which is characterized by sandstone, claystone, marl and coaly units. This units includes different levels of coal seams in different thicknesses. Organic matter is composed predominantly of woody and amorphous material, with a minor contribution of planty and coaly material. Kerogen in the deposits is type II/III, as indicated by organic petrographic observations and Rock-Eval data. Total organic carbon (TOC) values are generally between 0.01 and 1.44 %, but reach 5.81 % in the formation. Tmax values vary between 446 and 451 °C and indicate mature zone (Based on the value of 0.25 % TOC). Organic facies type BC, C and CD were identified in the investigated units. Organic facies BC is related sandstoneand marl lithofacies. This facis is deposited under an anoxic water column in a fine grained clastics, where rapid deposition creates anoxia in the sediments after deposition. This facies is characterized by average values of HI around 317 (equivalent to type II kerogene), TOC around 0.02 %, and an average of S2 of 0.04 mg HC/g of rock. Organic facies C is related to sandstone, marl and coal lithofacies. This facies is characterized by average values of HI around 176 (equivalent to type III kerogene), TOC around 0.19 %, and an average of S2 of 0.03 mg HC/g of rock. The organic matter is partly oxidized, and terrestrial. Organic facies C is the "gas-prone" facies. Organic facies CD is related to limestone, marl and coal lithofacies. This facies is characterized by average values of HI around 109 (equivalent to type III kerogene), TOC around 1.21 %, and an average of S2 of 1.43 mg HC/g rock. The organic matter is oxidized and reworked. Key Words: Western Taurus, Carboniferous, Pamucakyayla, Antalya Nappes, Organic Facies

  15. Reusable Energy and Power Sources: Rechargeable Batteries

    ERIC Educational Resources Information Center

    Hsiung, Steve C.; Ritz, John M.

    2007-01-01

    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…

  16. Reusable Energy and Power Sources: Rechargeable Batteries

    ERIC Educational Resources Information Center

    Hsiung, Steve C.; Ritz, John M.

    2007-01-01

    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…

  17. Choosing appropriate techniques for quantifying groundwater recharge

    USGS Publications Warehouse

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

    2002-01-01

    Various techniques are available to quantify recharge; however, choosing appropriate techniques is often difficult. Important considerations in choosing a technique include space/time scales, range, and reliability of recharge estimates based on different techniques; other factors may limit the application of particular techniques. The goal of the recharge study is important because it may dictate the required space/time scales of the recharge estimates. Typical study goals include water-resource evaluation, which requires information on recharge over large spatial scales and on decadal time scales; and evaluation of aquifer vulnerability to contamination, which requires detailed information on spatial variability and preferential flow. The range of recharge rates that can be estimated using different approaches should be matched to expected recharge rates at a site. The reliability of recharge estimates using different techniques is variable. Techniques based on surface-water and unsaturated-zone data provide estimates of potential recharge, whereas those based on groundwater data generally provide estimates of actual recharge. Uncertainties in each approach to estimating recharge underscore the need for application of multiple techniques to increase reliability of recharge estimates.

  18. Lightweight solid state rechargeable batteries

    SciTech Connect

    Hope, H.F.; Hope, S.F.

    1988-12-27

    This patent describes a solid state rechargeable battery of the alkaline or alkaline earth metal type which includes an anode, a polymer dielectric layer, a cathode and has means of current collection and carrying base which comprises a web of strands of carbon fibres or carbon graphite fibers and a coating of metal on the web.

  19. Hydrocarbon possibilities of concealed Mesozoic-Paleogene sediments below Himalayan nappes - reappraisal

    SciTech Connect

    Acharyya, S.K.; Ray, K.K.

    1982-01-01

    Hydrocarbon exploration of the Ganga (Ganges) and Sub-Himalayan basins indicates the presence of upper Neogene-Quaternary continental molasse and the absence of Paleogene sediments regarded as hydrocarbon source beds. Marine to brackish water Paleogene-lower Neogene sediments, closely fringing the Sub-Himalayan foothills, increase in thickness northward. Their presence and facies in the frontal schuppen zone and in the Lesser Himalayan windows, commonly in close association with upper Mesozoic shelf sediments, indicate a formerly greater width for the late Mesozoic-early Neogene shelf-miogeosynclinal basin. The pre-Tertiary rocks of the Lesser Himalayas are in nappes floored by the flat-lying sole thrust redesignated the Main Boundary thrust (MBT). Schuppen structure and lateral shortening complicate the geometry of the MBT. Pre-Tertiary tectonic grain and metamorphism, ubiquitously developed within the Lesser Himalayan cover rocks, are typically absent in the subjacent Paleogene-lower Neogene window-zone sediments. This opinion is corroborated by a few oil and gas shows from the Eocene limestone outcrops close to the MBT and also from the Lesser Himalayan pre-Tertiary metamorphic cover rocks.

  20. The pronounced seasonality of global groundwater recharge

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

  1. Estimate of regional groundwater recharge rate in the Central Haouz Plain, Morocco, using the chloride mass balance method and a geographical information system

    NASA Astrophysics Data System (ADS)

    Ait El Mekki, Ouassil; Laftouhi, Nour-Eddine; Hanich, Lahoucine

    2015-09-01

    Located in the extreme northwest of Africa, the Kingdom of Morocco is increasingly affected by drought. Much of the country is characterised by an arid to semi-arid climate and the demand for water is considerably higher than the supply, particularly on the Haouz Plain in the centre of the country. The expansion of agriculture and tourism, in addition to industrial development and mining, have exacerbated the stress on water supplies resulting in drought. It is therefore necessary to adopt careful management practices to preserve the sustainability of the water resources in this region. The aquifer recharge rate in the piedmont region that links the High Atlas and the Central Haouz Plain was estimated using the chloride mass balance hydrochemical method, which is based on the relationship between the chloride concentrations in groundwater and rainwater. The addition of a geographical information system made it possible to estimate the recharge rate over the whole 400 km2 of the study area. The results are presented in the form of a map showing the spatialized recharge rate, which ranges from 13 to 100 mm/year and the recharge percentage of the total rainfall varies from 3 to 25 % for the hydrological year 2011-2012. This approach will enable the validation of empirical models covering areas >6200 km2, such as the Haouz nappe.

  2. Nanomaterials for rechargeable lithium batteries.

    PubMed

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

    2008-01-01

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

  3. Rechargeable Aluminum-Ion Batteries

    SciTech Connect

    Paranthaman, Mariappan Parans; Liu, Hansan; Sun, Xiao-Guang; Dai, Sheng; Brown, Gilbert M

    2015-01-01

    This chapter reports on the development of rechargeable aluminum-ion batteries. A possible concept of rechargeable aluminum/aluminum-ion battery based on low-cost, earth-abundant Al anode, ionic liquid EMImCl:AlCl3 (1-ethyl-3-methyl imidazolium chloroaluminate) electrolytes and MnO2 cathode has been proposed. Al anode has been reported to show good reversibility in acid melts. However, due to the problems in demonstrating the reversibility in cathodes, alternate battery cathodes and battery concepts have also been presented. New ionic liquid electrolytes for reversible Al dissolution and deposition are needed in the future for replacing corrosive EMImCl:AlCl3 electrolytes.

  4. Electrically rechargeable REDOX flow cell

    NASA Technical Reports Server (NTRS)

    Thaller, L. H. (Inventor)

    1976-01-01

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

  5. Research on rechargeable oxygen electrodes

    NASA Technical Reports Server (NTRS)

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

    1971-01-01

    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.

  6. Iron-Air Rechargeable Battery

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

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

  7. Survey of rechargeable battery technology

    SciTech Connect

    Not Available

    1993-07-01

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

  8. Intensive rainfall recharges tropical groundwaters

    NASA Astrophysics Data System (ADS)

    Jasechko, Scott; Taylor, Richard G.

    2015-12-01

    Dependence upon groundwater to meet rising agricultural and domestic water needs is expected to increase substantially across the tropics where, by 2050, over half of the world’s population is projected to live. Rare, long-term groundwater-level records in the tropics indicate that groundwater recharge occurs disproportionately from heavy rainfalls exceeding a threshold. The ubiquity of this bias in tropical groundwater recharge to intensive precipitation is, however, unknown. By relating available long-term records of stable-isotope ratios of O and H in tropical precipitation (15 sites) to those of local groundwater, we reveal that groundwater recharge in the tropics is near-uniformly (14/15 sites) biased to intensive monthly rainfall, commonly exceeding the ∼70th intensity decile. Our results suggest that the intensification of precipitation brought about by global warming favours groundwater replenishment in the tropics. Nevertheless, the processes that transmit intensive rainfall to groundwater systems and enhance the resilience of tropical groundwater storage in a warming world, remain unclear.

  9. Charge Characteristics of Rechargeable Batteries

    NASA Astrophysics Data System (ADS)

    Maheswaranathan, Ponn; Kelly, Cormac

    2014-03-01

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

  10. Groundwater recharge and agricultural contamination

    USGS Publications Warehouse

    Böhlke, J.K.

    2002-01-01

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

  11. Evidence for dilution of deep, confined ground water by vertical recharge of isotopically heavy Pleistocene water

    SciTech Connect

    Siegel, D.I. )

    1991-05-01

    New analyses of the isotopic composition of water, {sup 14}C-dating of dissolved inorganic carbon, and order-of-magnitude Darcy calculations suggest that a dilute body of water, trending north-south in the Cambrian-Ordovician aquifer of Iowa, was emplaced as vertical recharge of Pleistocene-age water from the base of the Des Moines lobe of late Wisconsin time. The recharge occurred through more than 300 m of overlaying Silurian to Mississippian age rocks. The {delta}{sup 18}O values range from {minus}10{per thousand} to {minus}9{per thousand} for the dilute water body and are consistent with a mixture of Des Moines lobe meltwater and precipitation found today in the north-central US. These results suggest that (1) the climate at the end of the last glaciation was mild and (2) a ground-water stable isotope signature similar to that of modern precipitation in an aquifers recharge area is not a priori evidence for relatively recent recharge.

  12. Evaluation of a rechargeable pacemaker system.

    PubMed

    Stertzer, S H; DePasquale, N P; Cohn, L J; Bruno, M S

    1978-04-01

    A rechargeable-demand nickel-cadmium pulse generator for permanent transvenous cardiac pacing was evaluated in 66 patients. During a cumulative follow-up period of 2,333 patient months (194.4 patient years), failure of the pacing circuit occurred in 3 patients at 21, 25, and 27 months, respectively. Nine patients had difficulty accepting the recharging concept and, in 3 of these patients, it became necessary to replace the rechargeable generator with a conventional energy source. The overall failure rate of approximately 3% per year (including the 3 patients in whom it was necessary to remove the generator because of failure to recharge properly), coupled with the inconvenience of recharging, limits the usefulness of the rechargeable system compared to the newer lithium-powered generator. PMID:83632

  13. Caractères hydrochimiques des nappes des roches endogènes fissurées en zone tropicale humide: l'exemple de la Côte d'Ivoire

    NASA Astrophysics Data System (ADS)

    Faillat, J. P.; Blavoux, B.

    A set of 230 hydrochemical analysis of major constituents were carried out in the Ivory Coast, within a defined physical and geological environment. The statistical description of the data (conductivity, temperature, pH, Eh, Ca ++, Mg ++, Na +, K +, HCO 3, Cl, NO 3 et SO 4=) and some factors altering groundwaters chemistry in fissure aquifers (lithology, vegetation, men activities) are briefly presented.

  14. Variability in simulated recharge using different GCMs

    NASA Astrophysics Data System (ADS)

    Allen, D. M.; Cannon, A. J.; Toews, M. W.; Scibek, J.

    2010-10-01

    Variations in the prediction of recharge is addressed by comparing recharge simulated using climate data generated using a state-of-the-art downscaling method, TreeGen, with a range of global climate models (GCMs). The study site is the transnational Abbotsford-Sumas aquifer in coastal British Columbia, Canada and Washington State, USA, and is representative of a wet coastal climate. Sixty-four recharge zones were defined based on combinations of classed soil permeability, vadose zone permeability, and unsaturated zone depth (or depth to water table) mapped in the study area. One-dimensional recharge simulations were conducted for each recharge zone using the HELP hydrologic model, which simulates percolation through a vertical column. The HELP model is driven by mean daily temperature, daily precipitation, and daily solar radiation. For the historical recharge simulations, the climate data series was generated using the LARS-WG stochastic weather generator. Historical recharge was compared to recharge simulated using climate data series derived from the TreeGen downscaling model for three future time periods: 2020s (2010-2039), 2050s (2040-2069), and 2080s (2070-2099) for each of four GCMs (CGCM3.1, ECHAM5, PCM1, and CM2.1). Recharge results are compared on an annual basis for the entire aquifer area. Both increases and decreases relative to historical recharge are simulated depending on time period and model. By the 2080s, the range of model predictions spans -10.5% to +23.2% relative to historical recharge. This variability in recharge predictions suggests that the seasonal performance of the downscaling tool is important and that a range of GCMs should be considered for water management planning.

  15. Thermal history of crystalline nappes of the Maria Fold and Thrust Belt, west central Arizona

    NASA Astrophysics Data System (ADS)

    Knapp, James H.; Heizler, Matthew T.

    1990-11-01

    The thermal history of the crust in west central Arizona, as documented by 40Ar/39Ar step-heating analysis of mineral suites from crystalline nappes of the Maria fold and thrust belt, is characterized by three distinct stages for Late Cretaceous and Tertiary time. Regional heating of the crust occurred during basement-involved folding and thrust faulting in middle Late Cretaceous time (˜80-90 Ma) and represents the earliest phase recorded by the 40Ar/39Ar data. The second stage was dominated by uplift and slow cooling (5-10°C/m.y.) of the crust throughout latest Cretaceous and early Tertiary lime. Tectonic denudation in late Oligocene to early Miocene time resulted in rapid uplift and cooling of midcrastal rocks in the footwall of the Whipple-Buckskin-Rawhide detachment system, marking the final thermal signature in the region. Evidence for variable argon loss in the hornblende spectra implies exposure of differing structural levels within the thrust belt and/or significant thermal heterogeneity in the crust during Late Cretaceous orogenesis. Partially outgassed hornblende in the northern Granite Wash Mountains reflects temperatures of ˜450°C, whereas complete resetting of hornblende at Mesquite Mountain suggests that this area attained temperatures in excess of 500°C. In contrast, data from the northern Plomosa Mountains indicate that this area did not attain temperatures sufficient to completely degas biotite or K-feldspar (>350°C) during Late Cretaceous time. The range of early Tertiary muscovite and biotite ages in the region reflects slow cooling, presumably associated with uplift and erosion following crustal thickening. K-feldspars yield saddle-shaped age spectra with minimum apparent ages ranging from 22-28 Ma, and reflect quenching due to rapid exhumation of midcruslal to upper crustal rocks in the detachment terrain. Collectively, the data are consistent with either of two models for the thermal evolution of the crust in middle to late Tertiary time. Either (1) lower plate rocks were still sufficiently hot following Late Cretaceous heating that argon clocks were set simply due to rapid cooling or (2) the area experienced a renewed thermal input associated with extension, causing argon loss from previously cool rocks. Based on consideration of diffusion domain behavior in K-feldspars, we infer that a renewed thermal pulse was associated with the early stages of extension and was related to the cause for crustal weakening.

  16. Identifying and quantifying urban recharge: a review

    NASA Astrophysics Data System (ADS)

    Lerner, David N.

    2002-02-01

    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.

  17. Transformer Recharging with Alpha Channeling in Tokamaks

    SciTech Connect

    N.J. Fisch

    2009-12-21

    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. __________________________________________________

  18. 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...

  19. 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...

  20. Recharge at the Hanford Site: Status report

    SciTech Connect

    Gee, G.W.

    1987-11-01

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

  1. Reflections on Dry-Zone Recharge

    NASA Astrophysics Data System (ADS)

    Gee, G. W.

    2005-05-01

    Quantifying recharge in regions of low precipitation remains a challenging task. The design of permanent nuclear-waste isolation at Yucca Mountain, Nevada, the design of arid-site landfill covers and the pumping of groundwater in desert cities, like Las Vegas, are examples where accurate recharge estimates are needed because they affect billion-dollar decisions. Recharge cannot be measured directly and must rely on estimation methods of various kinds including chemical tracers, thermal profiling, lysimetry, and water-balance modeling. Chemical methods, like chloride-mass-balance can significantly underestimate actual recharge rates and water-balance models are generally limited by large uncertainties. Studies at the U. S. Department of Energy's Hanford Site in Washington State, USA illustrate how estimates of recharge rates have changed over time and how these estimates can affect waste management decisions. Lysimetry has provided reliable estimates of recharge for a wide range of surface condittions. Lysimetric observations of reduced recharge, resulting from advective drying of coarse rock piles, suggest a way to avoid costly recharge protection using titanium shields at Yucca Mountain. The Pacific Northwest National Laboratory is funded by the U. S. Department of Energy under contract DE-AC05-76-RL01830.

  2. Lithium Cells Accept Hundreds Of Recharges

    NASA Technical Reports Server (NTRS)

    Shen, David H.; Surampudi, Subbarao; Deligiannis, Fotios; Halpert, Gerald

    1991-01-01

    New mixed-solvent electrolyte increases number of times room-temperature lithium cell discharged and recharged. Conductivity 70 percent higher. Useful in such other room-temperature rechargeable lithium cells as lithium/niobium triselenide and lithium molybdenum disulfide systems.

  3. Rechargeable lithium-ion cell

    DOEpatents

    Bechtold, Dieter; Bartke, Dietrich; Kramer, Peter; Kretzschmar, Reiner; Vollbert, Jurgen

    1999-01-01

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

  4. P-T Alpine metamorphic evolution of the Monte Rosa nappe along the Piedmont Zone boundary (Gressoney Valley, NW Italy)

    NASA Astrophysics Data System (ADS)

    Gasco, Ivano; Borghi, Alessandro; Gattiglio, Marco

    2011-11-01

    The pseudosection modelling of two chemical systems (both metabasic and metapelitic) allowed to reconstruct the exhumation P-T path followed by the southern slope of the Monte Rosa nappe (Upper Gressoney Valley) during the Alpine orogenesis. The metamorphic evolution of the polymetamorphic basement complex from the Monte Rosa nappe is marked by texturally distinct mineral assemblages, defining four Alpine metamorphic stages (M1 to M4) reflecting a sequence of different P-T conditions. Well preserved eclogitic boudins (M1 and M2 assemblages) were investigated to reconstruct the HP history related to the subduction phase, while re-equilibrated metapelites allowed to infer the P-T conditions attained during the development of the regional foliation (M3 and M4 assemblages). The HP stage (M1) occurred at 550-570 °C and 24-27 kbar and is characterised by the assemblage Omp + Grt + Lws + Phe + Qtz + Gln ± Tlc in the eclogites. The M2 metamorphic stage consists of the assemblage Omp + Grt + Barr + Zo + Phe + Pg + Qtz and developed at 590-630 °C and 14.5-16.5 kbar suggesting a T increasing during decompression. After a further decompressional stage associated with a T decrease, the M3 tectono-metamorphic stage developed syn-kinematically with the main regional foliation S1. It is marked by the assemblage Phe + Pg + Grt + Chl + Ab/Olig + Hbl + Qtz + Rt/Ilm ± Bt in metapelites and by Cam (blue-green) + Chl + Ab + Bt + Qtz + Rt in the re-equilibrated metabasite boudins. S1 developed during increasing T (from 550 to ca. 600 °C) and sligthly increasing P (from 7 to 9 kbar). Finally, the M4 assemblage grew as rims over the M3 minerals or overgrew the S1 regional foliation (albite porphyroblasts overgrowing the S1 foliation already defined by albite) and therefore can be considered as the final stage of the M3 stage. The P-T path proposed for the Monte Rosa nappe differs from previous works. In particular, we propose post-eclogitic decompression trajectory up to 7 kbar, followed by a P-T increase that can be related to a second burial-exhumation cycle during Alpine orogenesis, as recently reported for other Alpine units.

  5. A purely structural restoration of the NFP20-East cross section and potential tectonic overpressure in the Adula nappe (central Alps)

    NASA Astrophysics Data System (ADS)

    Pleuger, Jan; Podladchikov, Yuri Y.

    2014-05-01

    Common extrusion-type models for the high- to ultrahigh-pressure Adula nappe require a major normal fault along the top of this unit which is not conveyed in the structural record. This implies that such a normal fault existed but was completely erased during later deformational stages. However, there is evidence that decompression occurred during top-to-the-foreland thrusting. We performed a new, purely structural kinematic restoration of the central part of the NFP20-East cross section in order to estimate the burial depths of individual units without converting petrological pressure data into depth under the assumption that pressures were lithostatic. The results show that pressures within most of the units were close to but somewhat higher than lithostatic for several stages of the tectono-metamorphic history. Only for the maximum burial stage of the Adula nappe, we estimate local tectonic overpressures of 40 to 80% of the lithostatic pressures. Accepting such an amount of overpressure, which is moderate compared to values theoretically possible, the Adula nappe was probably not subducted to subcrustal depth. We propose that the structural record of the Penninic nappe stack is quite complete and suggest that the decay of tectonic overpressure is a feasible explanation for decompression from eclogite- to amphibolite-facies conditions during thrusting. Consequently, exhumation and convergence rates of the Eocene to Oligocene Alps may be smaller than previously assumed.

  6. Recharge and groundwater models: An overview

    USGS Publications Warehouse

    Sanford, W.

    2002-01-01

    Recharge is a fundamental component of groundwater systems, and in groundwater-modeling exercises recharge is either measured and specified or estimated during model calibration. The most appropriate way to represent recharge in a groundwater model depends upon both physical factors and study objectives. Where the water table is close to the land surface, as in humid climates or regions with low topographic relief, a constant-head boundary condition is used. Conversely, where the water table is relatively deep, as in drier climates or regions with high relief, a specified-flux boundary condition is used. In most modeling applications, mixed-type conditions are more effective, or a combination of the different types can be used. The relative distribution of recharge can be estimated from water-level data only, but flux observations must be incorporated in order to estimate rates of recharge. Flux measurements are based on either Darcian velocities (e.g., stream base-flow) or seepage velocities (e.g., groundwater age). In order to estimate the effective porosity independently, both types of flux measurements must be available. Recharge is often estimated more efficiently when automated inverse techniques are used. Other important applications are the delineation of areas contributing recharge to wells and the estimation of paleorecharge rates using carbon-14.

  7. Variabilité climatique durant le Quaternaire dans la nappe du Tarat (Arlit, Niger)

    NASA Astrophysics Data System (ADS)

    Dodo, Abdelkader; Maria Zuppi, Gian

    1999-03-01

    The concentration of major elements and environmental isotopes in the Carboniferous (Guezouman and Tarat), Triassic (Teloua) and Quaternary aquifers allows to describe the ground-water flow and to define the upward leakage. 18O and 2H in water samples from Guezouman and some Tarat aquifers fall on a regressive line with the equation, ?2H = (8.01 ± 0.50) ?218O + (3.85 ± 3.56), similar to that found for old groundwater in the northern and southern Sahara. The isotopic difference between the Arlit area and the easterly Djado basin groundwater results from the combined effects of continentality and altitude on meteoric waters. The carbon 14 ages, the palaeo-temperatures evaluated from oxygen 18 and nitrate contents in the Tarat aquifer show climatic variations consisting of two humid periods at 10 000 and 30 000 years separated by a warmer period at 25 000. The mean temperatures of the palaeo-recharge, estimated using oxygen 18 data, are 18 °C during the Holocene, 20 °C at 25 000 years and 16 °C at 30 000 years. Water infiltrating during the warming period shows 79 mg·L -1 nitrates. High nitrates could be due to an important meteorological event which entrained and stored organic matter from the surface vegetation and soil by infiltration.

  8. The internal deformation of the Peridotite Nappe of New Caledonia: A structural study of serpentine-bearing faults and shear zones in the Koniambo Massif

    NASA Astrophysics Data System (ADS)

    Quesnel, Benoît; Gautier, Pierre; Cathelineau, Michel; Boulvais, Philippe; Couteau, Clément; Drouillet, Maxime

    2016-04-01

    We present a structural analysis of serpentine-bearing faults and shear zones in the Koniambo Massif, one of the klippes of the Peridotite Nappe of New Caledonia. Three structural levels are recognized. The upper level is characterized by a dense network of fractures. Antigorite and polygonal serpentine form slickenfibers along fault planes with distinct kinematics. As a result, the upper level keeps the record of at least two deformation events, the first associated with the growth of antigorite (WNW-ESE extension), the second with the growth of polygonal serpentine (NW-SE compression). The lower level coincides with the 'serpentine sole' of the nappe, which consists of massive tectonic breccias overlying a layer of mylonitic serpentinites. The sole records pervasive tangential shear with top-to-SW kinematics and represents a décollement at the base of the nappe. The intermediate level is characterized by the presence of several meters-thick conjugate shear zones accommodating NE-SW shortening. Like the sole, these shear zones involve polygonal serpentine and magnesite as the main syn-kinematic mineral phases. The shear zones likely root into the basal décollement, either along its roof or, occasionally, around its base. Compared to top-to-SW shearing along the sole, the two deformation events recorded in the upper level are older. The three structural levels correlate well with previously recognized spatial variations in the degree of serpentinization. It is therefore tempting to consider that the intensity of serpentinization played a major role in the way deformation has been distributed across the Peridotite Nappe. However, even the least altered peridotites, in the upper level, contain so much serpentine that, according to theoretical and experimental work, they should be nearly as weak as pure serpentinite. Hence, no strong vertical gradient in strength due to variations in the degree of serpentinization is expected within the exposed part of the nappe. Our proposal is that strain localization along the serpentine sole results from the juxtaposition of the nappe, made of weak serpentinized peridotites, against the strong mafic rocks of its substratum. This interpretation is at odds with the intuitive view that would consider the nappe, made of peridotites, as stronger than its basement.

  9. U-Pb detrital zircon analysis of pre-Timanian passive-margin successions and Caledonian nappes of North Norway

    NASA Astrophysics Data System (ADS)

    Zhang, Wen; Roberts, David; Pease, Victoria

    2014-05-01

    The Neoproterozoic passive-margin successions of the pre-Timanian margin, northern Norway, include the thick, deep-marine to deltaic, basinal Barents Sea Group and a fluvial to shallow-marine platformal domain to the south. To the west, different rock successions occur in the Lower, Middle and Upper Allochthons of the Norwegian Caledonides. Many detrital investigations of circum-Arctic terranes claim to recognize a Timanian 'fingerprint' (c. 610-560 Ma zircon ages from subduction-related granitoids generated during Timanian orogenesis), yet the detrital zircon U-Pb age spectrum of these sediments has not been fully assessed. Provenance analysis of pre-Timanian passive-margin formations and selected Caledonian nappe rocks is used to characterize their provenance. This will allow us to evaluate to what extent (if any) these passive-margin sediments have been recycled, to recognize them in younger sedimentary formations, and to possibly correlate the now widely distributed allochthonous fragments which occur throughout the circum-Arctic. Twelve samples were collected across four tectonic units. The principal results so far include: 1) A single sample (STP1) from the Late Ediacaran Stáhpogieddi Formation, Gaissa Nappe Complex (GNC), has a major peak at c. 550 Ma and is likely to represent deposition in the Timanian foreland basin. Another sample (BRE1) from the same region is much different with two major peaks at 2.8-2.7 Ga and 2.4 Ga whose significance remains to be determined. 2) Seven samples show classic Baltican affinity, including FUG1, GRN1 and GMS1 from parautochthonous/autochthonous formations in the Tanafjorden-Varangerfjorden Region (TVR), VEI1 and F-4 from formations lying unconformably upon in-situ Palaeoproterozoic- Archean metamorphic complexes, and LAN1 and IFJ1 from the Laksefjord Nappe Complex. Their provenance includes: i) age peaks at c. 2.8-2.7 Ga, indicating input from the northern Fennoscandian Shield which is dominated by Neoarchaean complexes; ii) age peaks at 1.95-1.8 Ga derived from Palaeoproterozoic terranes of the craton and deformed during the 1.9-1.8 Ga Svecofennian orogeny; iii) Mesoproterozoic grains mainly from the TVR on Varanger Peninsula (also found earlier in a deltaic formation in the Barents Sea Group) with a non-specific provenance including a source possibly concealed beneath the Caledonian nappes and adjacent continental shelf, or a northward extension of the Sveconorwegian/Grenvillian orogeny, or a Tonian-emplaced, sandstone-dominated thrust sheet derived from the margin of Rodinia. In addition, the three samples from the TVR define a time-sequence with older grains decreasing and younger grains increasing stratigraphically upward. 3) Samples (STY1, SF1 and KG1) collected from formations in the Barents Sea Region have similar 1.8 Ga and 2.8-2.7 Ga peaks and abundant Mesoproterozoic grains, which likely derive from the passive margin before Timanian orogenesis, as no detrital zircon grains younger than 1000 Ma are present. The new provenance data help to confirm the interpretation of the Neoproterozoic Barents Sea Group succession as an established passive-margin depositional system with little or no coeval magmatism. The Timanian 'fingerprint' found in the Stáhpogieddi Formation suggests that further remnants of the Timanian foreland basin (which is represented in Russia as the Mezen Basin) may eventually be detected in the shallow-marine, platformal domain of the TVR.

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

    USGS Publications Warehouse

    Sophocleous, M.

    1992-01-01

    The results of a 6 year recharge study in the Great Bend Prairie of central Kansas are statistically analyzed to regionalize the limited number of site-specific but year-round measurements. Emphasis is placed on easily measured parameters and field-measured data. The results of the statistical analysis reveal that a typical recharge event in central Kansas lasts 5-7 days, out of which 3 or 4 days are precipitation days with total precipitation of ??? 83 mm. The maximum soil-profile water storage and the maximum groundwater level resulting from the recharge event exhibit the lowest coefficients of variation, whereas the amount of recharge exhibits the highest coefficient of variation. The yearly recharge in the Great Bend Prairie ranged from 0 to 177 mm with a mean of 56 mm. Most of the recharge events occur during the months of April, May, and June, which coincide with the months of highest precipitation in the region. A multiple regression analysis revealed that the most influential variables affecting recharge are, in order of decreasing importance, total annual precipitation average maximum soil-profile water storage during the spring months, average shallowest depth to water table during the same period, and spring rainfall rate. Classification methods, whereby relatively homogeneous hydrologic-unit areas based on the four recharge-affecting variables are identified, were combined with a Geographic Information Systems (ARC/INFO) overlay analysis to derive an area-wide map of differing recharge regions. This recharge zonation is in excellent agreement with the field-site recharge values. The resulting area-weighted average annual recharge for the region is 36 mm. ?? 1992.

  11. 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)

  12. Proposed artificial recharge studies in northern Qatar

    USGS Publications Warehouse

    Kimrey, J.O.

    1985-01-01

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

  13. UHT overprint of HP rocks? A case study from the Adula nappe complex (Central Alps, N Italy)

    NASA Astrophysics Data System (ADS)

    Tumiati, Simone; Zanchetta, Stefano; Malaspina, Nadia; Poli, Stefano

    2014-05-01

    The Adula-Cima Lunga nappe complex is located on the eastern flank of the Lepontine Dome and represents the highest of the Lower Penninic units of the Central Alps. The Adula nappe largely consists of orthogneiss and paragneiss of pre-Mesozoic origin, variably retrogressed eclogites preserved as boudins within paragneiss, minor ultramafic bodies and metasedimentary rocks of presumed Mesozoic age. The higher metamorphic conditions have been estimated for the peridotite lenses in the southern part of the nappe at pressure over 3.0 GPa and temperature of 800-850°C. Garnet lherzolite bodies crop out at three localities, from west to east: Cima di Gagnone, Alpe Arami and Mt. Duria. After the partial subduction of the European distal margin beneath the Africa-Adria margin, the HP rocks were overprinted by an upper amphibolite facies metamorphism that postdates the main phase of nappe stacking. In the southern sector of the Lepontine Dome, adjacent to the Insubric Fault, metamorphic conditions promoted extensive migmatization of both metasedimentary and metagranitoid rocks. In one single outcrop, at Monte Duria, garnet lherzolites occur in m-sized boudins hosted within partly granulitized amphibole-bearing and k-feldspar gneisses that contain also some decimeter-sized boudins of both mafic and metapelitic eclogites. This rock association is in turn embedded within the migmatitic gneisses that form most of the southern sector of the Adula nappe. Petrographic and chemical analyses indicate that garnet peridotite is composed of olivine (XMg=0.88), orthopyroxene, clinopyroxene and garnet (Py68; Cr2O3 up to 1.45 wt%) with inclusions of Cr-rich spinel (up to Cr/(Al+Cr)=0.55) surrounded by kelyphitic symplectites of opx + cpx/amph + spl. These reaction produced double coronas, one composed of opx (former ol) and one composed of cpx + opx+ spl. In one kelyphite, we observed the uncommon occurrence of ZrO2 (baddeleyite) and ZrTi2O6 (srilankite). Tiny crystals of these two Zr-bearing phases (˜1 ?m) are invariably located in the opx corona after ol. The cpx + opx + spl corona (after grt) contains, instead, zircon. Baddeleyite should have formed through a reaction of the type Mg2SiO4 + ZrSiO4 = MgSiO3 + ZrO2. ZrO2 and ZrTi2O6 display a low amount of solid solution. These compositions are consistent with T below 1200°C, but an improvement of the thermodynamic model is needed in order to better constrain the T of the granulitic overprint on the basis of these Zr-bearing phases. In mafic eclogites, the HP association consists of garnet (Py40Alm37Sp20), omphacite (preserved as inclusion, containing Jd30 and Mg# 0.87), kyanite and minor quartz. Omphacite is almost always replaced by cpx (Jd5) + plag (An55) symplectites. Garnet is surrounded by plag (An33) + opx (En70) symplectites. Kyanite is replaced by plag (An84) + spinel + sapphirine. The spinel-sapphirine Fe-Mg thermometer suggests T of about 850°C due to granulite-facies overprint. We observed sapphirine associated with cpx + opx + plag also in kelyphites after garnet in clinopyroxenites. In eclogitic metapelites, kyanite is replaced by a corundum + anorthite ± spinel assemblage. A corundum-rich layer occurs between eclogites and the host gneiss. Cm-sized emerald green zoisite in this layer is replaced by anorthitic plagioclase ± cpx ± spinel ± calcite. The observed assemblages point to a diffuse granulitization of both the peridotites and the hosting HP rocks of Mt. Duria, suggesting a nearly isothermal decompression from peak-pressure conditions. The surrounding migmatitic gneiss do not display evidence of such granulitic event, having been formed at T<700°C. The mechanism and timing of emplacement of the garnet peridotite and associated HP-HT rocks in the country migmatites, and whether or not the subduction event is related to the Alpine or to an older orogenic cycle are still a matter of debate.

  14. Characterization of basement highs in hyper-extended rift systems: examples from the Err nappe, SE Switzerland.

    NASA Astrophysics Data System (ADS)

    Epin, Marie-Eva; Manatschal, Gianreto; Haupert, Isabelle; Decarlis, Alessandro

    2015-04-01

    Despite of the fact that many studies investigated magma-poor rifted margins, there are still open questions that are related to the nature of basement highs and the timing and processes related to their formation. While these questions are difficult to answer at present-day margins due to the lack of drill hole data, field analogues provide important insights and enable to find some answers to these questions. This is particularly true for the Err nappe in southeastern Switzerland, which is one of the world's few exposed and preserved rift-related hyper-extended domains. This nappe preserves a rift related extensional detachment system that is exposed over more than 200km2, characterized by distinctive black gouges and green cataclasites and preserving the relation to its hanging wall and footwall rocks and the pre-, syn-, and post-tectonic sediments. The aim of our study was to investigate the 3D architecture of the detachment system based on detailed mapping of this structure north and south of the Julier valley between Bivio and San Moritz in Central Grisons, SE Switzerland. Our results show the lateral variation of the morphology of the major detachment fault and its relation to extensional allochthons and the pre-, syn- and post-tectonic sediments. The main observation is that the architecture of the detachment system changes over very short distance across the Julier valley. While in the north the detachment is overlain by an allochthonous block (e.g. the Bardella block), to the south this block disappears and the detachment fault is exhumed at the seafloor. The mapping of the syn-tectonic sediments show that they are thick in the north and get thinner to the south where they are locally absent and the post-rift sediments directly overlie the detachment system. Furthermore the syn-tectonic sediments are locally characterized by basement clasts. These relationships suggest a rapid change from a domain where the detachment is overlain by allochthons and thick syn-tectonic sediments to a domain where the detachment is exposed. The lack of syn-rift sediments and the prominent hiatus suggest that the detachment formed a basement high south of the Julier valley. The overall observations are reminiscent of either a core-complex type structure or a lateral ramp of a detachment fault marking the lateral transition from a hanging wall to a footwall controlled topography. In our presentation we will expose the field relationships and will discuss the tectonic processes and the timing of these structures as well as discuss the nature of the structure controlling the observed 3D geometry of the detachment system.

  15. Estimated recharge rates at the Hanford Site

    SciTech Connect

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

    1995-02-01

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

  16. A slice of Upper Allochthon in a Middle Allochthon terrain? An ID-TIMS U-Pb study of the Hardanger-Ryfylke Nappe Complex, SW-Norway

    NASA Astrophysics Data System (ADS)

    Roffeis, C.; Corfu, F.; Gabrielsen, R. H.

    2012-04-01

    In southwestern Norway, Caledonian Nappes overly autochthonous and parautochthonous basement. The Hardanger-Ryfylke Nappe Complex is positioned south of the Jotun Nappe Complex, both assigned to the Middle Allochthon. It comprises a great variety of magmatic and sedimentary rocks, of greenschist to amphibolite facies metamorphic conditions. Previous extensive mapping, structural and geochemical analyses had distinguished three main units separated by mylonitic thrust zones, from bottom to top, the Dyrskard, Kvitenut and Revsegg nappe sheets. The available geochronological framework, established with Rb-Sr whole rock data, indicated mainly Mesoproterozoic ages for magmatic crystallization and subsequent deformation. Emplacement of the nappe stack occurred during the Caledonian orogeny but it is uncertain whether the three units were thrust as separate slices or together as one block. To increase our understanding on the evolution of these nappes we have carried out ID-TIMS U-Pb analyses using mainly single grains of zircon, titanite, rutile and apatite stemming from orthogneisses, metavolcanics, neosomes, pegmatites and granites. Our data indicate both similarities and differences in the evolution of the three units. The lowermost Dyrskard Group comprises metarhyolites giving a crystallization age of about 1500 Ma. Metamorphism and deformation led to the formation of leucosomes at ca. 1000 Ma, also indicating a metamorphic overprint at ca 430 Ma. The overlying Kvitenut Complex is dominated by orthogneisses with an age of crystallization of ca. 1600 Ma, and strong zircon resetting during metamorphism at 1000 Ma, both typical features of the main gneisses in the Jotun Nappe Complex. Leucosomes and a major granite body have zircon ages of 990-1000 Ma, comparable to that of the Dyrskard Group, which might suggest coeval evolution during this episode. In the mylonitic thrust zone between Dyrscard and Kvitenut two generations of titanite occur, one revealing a Caledonian age at 430 Ma, but also an older one, which we tentatively interpret as giving the time of Sveconorwegian thrusting of Kvitenut on to Dyrskard which also reveals a later metamorphic overprint at around 930 Ma. Metamorphic overprint during the Caledonian event formed local pegmatites in both units. The uppermost Revsegg Formation consists mainly of paragneisses. Dating of intrusive bodies of gabbro and granodiorite is still in progress, and hampered by the predominant xenocrystic character of the zircon population in the felsic units. Zircon and rutile in pegmatitic rocks indicate Caledonian intrusion and metamorphism at 430 Ma. However, in contrast to the other nappe sheets, in the Revsegg Formation we also find evidence for a ca. 450 Ma event in various minerals and lithologies. This age is not typical for the Middle Allochthon whereas it would fit the end of the Ordovician evolution of the upper Allochthon. Such an affinity had originally been proposed by Naterstad et al. (1973) but could not be confirmed by Rb-Sr work. Our data, however, point in that direction. Naterstad et al. 1973. Norges Geologiske Undersøkelse

  17. Des Moines.

    ERIC Educational Resources Information Center

    Gore, Deborah, Ed.

    1988-01-01

    This document, intended for elementary students, contains articles and activities designed to acquaint young people with the history of Des Moines, Iowa. The articles are short, and new or difficult words are highlighted and defined for young readers. "The Raccoon River Indian Agency" discusses the archeological exploration of the indian…

  18. Towards a calcium-based rechargeable battery

    NASA Astrophysics Data System (ADS)

    Ponrouch, A.; Frontera, C.; Bardé, F.; Palacín, M. R.

    2016-02-01

    The development of a rechargeable battery technology using light electropositive metal anodes would result in a breakthrough in energy density. For multivalent charge carriers (Mn+), the number of ions that must react to achieve a certain electrochemical capacity is diminished by two (n = 2) or three (n = 3) when compared with Li+ (ref. ). Whereas proof of concept has been achieved for magnesium, the electrodeposition of calcium has so far been thought to be impossible and research has been restricted to non-rechargeable systems. Here we demonstrate the feasibility of calcium plating at moderate temperatures using conventional organic electrolytes, such as those used for the Li-ion technology. The reversibility of the process on cycling has been ascertained and thus the results presented here constitute the first step towards the development of a new rechargeable battery technology using calcium anodes.

  19. Battery driven vehicle and recharging system

    SciTech Connect

    Arbisi, D. S.

    1985-02-12

    A battery-driven car which has an electrical system including a minimum number of electric storage batteries as the power source, a high-voltage converter with a high-voltage capacitor bank for driving a direct current impulse motor combined with a generator for supplying current to motor/generator sets respectively integrated with the wheels of the vehicle to drive the same or for recharging the batteries in accordance with a microprocessor control system, the wheel-actuated generators providing recharging current for the batteries whenever the motor component is not being energized and in addition, said electrical system also including an air-driven turbine generator component for recharging the batteries when the vehicle reaches a predetermined speed in accordance with the microprocessor controls.

  20. Using groundwater levels to estimate recharge

    USGS Publications Warehouse

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

    2002-01-01

    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.

  1. Towards a calcium-based rechargeable battery.

    PubMed

    Ponrouch, A; Frontera, C; Bardé, F; Palacín, M R

    2016-02-01

    The development of a rechargeable battery technology using light electropositive metal anodes would result in a breakthrough in energy density. For multivalent charge carriers (M(n+)), the number of ions that must react to achieve a certain electrochemical capacity is diminished by two (n = 2) or three (n = 3) when compared with Li(+) (ref. ). Whereas proof of concept has been achieved for magnesium, the electrodeposition of calcium has so far been thought to be impossible and research has been restricted to non-rechargeable systems. Here we demonstrate the feasibility of calcium plating at moderate temperatures using conventional organic electrolytes, such as those used for the Li-ion technology. The reversibility of the process on cycling has been ascertained and thus the results presented here constitute the first step towards the development of a new rechargeable battery technology using calcium anodes. PMID:26501412

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

    USGS Publications Warehouse

    Sophocleous, M.; Perry, C.A.

    1985-01-01

    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. ?? 1985.

  3. Impacts of vegetation change on groundwater recharge

    NASA Astrophysics Data System (ADS)

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

    2003-12-01

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

  4. Results of the radiological survey at the Napp Chemical Company, 199 Main Street, Lodi, New Jersey (LJ076)

    SciTech Connect

    Foley, R.D.; Floyd, L.M.; Carrier, R.F.

    1989-11-01

    Maywood Chemical Works (MCW) of Maywood, New Jersey, generated process wastes and residues associated with the production and refining of thorium and thorium compounds from monazite ores from 1916 to 1956. MCW supplied rare earth metals and thorium compounds to the Atomic Energy Commission and various other government agencies from the late 1940s to the mid-1950s. Area residents used the sandlike waste from this thorium extraction process mixed with tea and cocoa leaves as mulch in their yards. Some of these contaminated wastes were also eroded from the site into Lodi Brook. At the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory conducts investigative radiological surveys of properties in the vicinity of MCW to determine whether a property is contaminated with radioactive residues, principally {sup 232}Th, derived from the MCW site. The survey typically includes direct measurement of gamma radiation levels and soil sampling for radionuclide analyses. The survey of this site, the Napp Chemical Company, 199 Main Street, Lodi, New Jersey (LJ076), was conducted during 1987. Results of the survey demonstrated no radionuclide concentrations in excess of the DOE Formerly Utilized Sites Remedial Action Program criteria. The radionuclide distributions were not significantly different from normal background levels in the northern New Jersey area. 4 refs., 8 figs., 3 tabs.

  5. Nappes, tectonics of oblique plate convergence, and metamorphic evolution related to 140 million years of continuous subduction, Franciscan Complex, California

    SciTech Connect

    Wakabayashi, J. )

    1992-01-01

    This paper presents a new synthesis of Franciscan Complex tectonics, with the emphasis on the pre-San Andreas fault history of these rocks. Field relations suggest that the Franciscan is characterized by nappe structures that formed during sequential accretion at the trench. The presence of these structures along with other field relations, including the lack of evidence for large offset of conglomerate suites, indicates that strike-slip fault systems of large displacement ({gt}500 km) did not cut the Franciscan Complex during subduction. Regional geology and comparisons to modern arc-trench systems suggest that strike-slip faulting associated with oblique subduction took place inboard (east) of the Franciscan in the vicinity of the magmatic arc. The Franciscan varies along strike, because individual accreted elements (packets of trench sediment, seamounts, etc.) did not extend the full length of the trench. Different depths of underplating, distribution of post-metamorphic faulting, and level of erosion produced the present-day surface distribution of high P/T metamorphism. Franciscan Complex tectonic history is presented in this paper.

  6. Global-scale modeling of groundwater recharge

    NASA Astrophysics Data System (ADS)

    Döll, P.; Fiedler, K.

    2008-05-01

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

  7. Global-scale modeling of groundwater recharge

    NASA Astrophysics Data System (ADS)

    Döll, P.; Fiedler, K.

    2007-11-01

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

  8. Improved Separators For Rechargeable Lithium Cells

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

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

  10. The relative contributions of summer and cool-season precipitation to groundwater recharge, Spring Mountains, Nevada, USA

    NASA Astrophysics Data System (ADS)

    Winograd, Isaac J.; Riggs, Alan C.; Coplen, Tyler B.

    A comparison of the stable-isotope signatures of spring waters, snow, snowmelt, summer (July thru September) rain, and cool season (October thru June) rain indicates that the high-intensity, short-duration summer convective storms, which contribute approximately a third of the annual precipitation to the Spring Mountains, provide only a small fraction (perhaps 10%) of the recharge to this major upland in southern Nevada, USA. Late spring snowmelt is the principal means of recharging the fractured Paleozoic-age carbonate rocks comprising the central and highest portion of the Spring Mountains. Daily discharge measurements at Peak Spring Canyon Creek during the period 1978-94 show that snowpacks were greatly enhanced during El Niño events. Résumé La comparaison des signatures isotopiques stables des eaux de sources, de neige, de fonte de neige, des pluies d'été (juillet à septembre) et de saison froide (octobre à juin) montre que les précipitations convectives d'été de forte intensité et de courte durée, apportant un tiers des précipitations annuelles reçues par les Monts Spring, ne participent que pour une faible part (10%) à la recharge de cette importante zone d'altitude du sud du Nevada (États-Unis). La fonte tardive de la neige au printemps constitue l'essentiel de la recharge des roches carbonatées fracturées d'âge paléozoïque formant la partie centrale et la plus haute des Monts Spring. Les données journalières de débit sur la rivière du canyon de Peak Spring, entre 1978 et 1994, montrent que les hauteurs de neige ont été plus élevées pendant les événements El Niño. Resumen La comparación entre las marcas isotópicas de aguas de manantiales, nieve, deshielo, lluvias de verano (julio a septiembre) y resto de lluvias (octubre a junio) indican que las tormentas de verano, de corta duración y gran intensidad, las cuales suponen alrededor de un tercio de la precipitación total anual en las Spring Mountains, proporcionan sólo una fracción pequeña (alrededor del 10%) de la recarga en esta zona al sur de Nevada (EE.UU.). El deshielo de finales de la primavera es la principal fuente de recarga de las rocas carbonatadas fracturadas de edad Paleozoica que forman las partes central y superior de las Spring Mountains. Las medidas de descarga diarias en el Desfiladero de Peak Spring Canyon durante 1978-94 muestran que los espesores de nieve aumentaron coincidiendo con los fenómenos de El Niño.

  11. 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.

  12. Estimating recharge rates with analytic element models and parameter estimation

    USGS Publications Warehouse

    Dripps, W.R.; Hunt, R.J.; Anderson, M.P.

    2006-01-01

    Quantifying the spatial and temporal distribution of recharge is usually a prerequisite for effective ground water flow modeling. In this study, an analytic element (AE) code (GFLOW) was used with a nonlinear parameter estimation code (UCODE) to quantify the spatial and temporal distribution of recharge using measured base flows as calibration targets. The ease and flexibility of AE model construction and evaluation make this approach well suited for recharge estimation. An AE flow model of an undeveloped watershed in northern Wisconsin was optimized to match median annual base flows at four stream gages for 1996 to 2000 to demonstrate the approach. Initial optimizations that assumed a constant distributed recharge rate provided good matches (within 5%) to most of the annual base flow estimates, but discrepancies of >12% at certain gages suggested that a single value of recharge for the entire watershed is inappropriate. Subsequent optimizations that allowed for spatially distributed recharge zones based on the distribution of vegetation types improved the fit and confirmed that vegetation can influence spatial recharge variability in this watershed. Temporally, the annual recharge values varied >2.5-fold between 1996 and 2000 during which there was an observed 1.7-fold difference in annual precipitation, underscoring the influence of nonclimatic factors on interannual recharge variability for regional flow modeling. The final recharge values compared favorably with more labor-intensive field measurements of recharge and results from studies, supporting the utility of using linked AE-parameter estimation codes for recharge estimation. Copyright ?? 2005 The Author(s).

  13. Recharging Our Sense of Idealism: Concluding Thoughts

    ERIC Educational Resources Information Center

    D'Andrea, Michael; Dollarhide, Colette T.

    2011-01-01

    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…

  14. Application potential of rechargeable lithium batteries

    SciTech Connect

    Hunger, H.F.; Bramhall, P.J.

    1983-10-01

    Rechargeable lithium cells with Cr /SUB 0.5/ V/sub 0/ /sub 5/S/sub 2/ and MoO/sub 3/ cathodes were investigated in the temperature range of -30/sup 0/C to +25/sup 0/C. The electrolyte was 1.5M LiAsF/sub 6/ in 2-methyl tetrahydrofuran with tetrahydrofuran (50:50 V percent). Current densities and capacities as a function of temperature, cathode utilization efficiencies versus cycle life, and shelf lives were determined. The state of charge could be related to open circuit voltages after partial discharge. The potential of the system for communication applications is discussed. Recent advances in rechargeable lithium batteries were mainly due to the discovery of stable, cyclic ether electrolyte solvents (1) and to the use of rechargeable cathode materials (2). The practical usefulness of rechargeable lithium cells with Cr /SUB 0.5/ V /SUB 0.5/ S/sub 2/ and MoO/sub 3/ cathodes was investigated in the temperature range of -30/sup 0/C to +25/sup 0/C. The electrolyte was mainly 1.5M LiAsF/sub 6/ in 2-methyl tetrahydrofuran with tetrahydrofuran (50:50 V percent). The two cathode materials were chosen because Cr /SUB 0.5/ V /SUB 0.5/ S/sub 2/ resembles TiS/sub 2/ in capacity and cycling behavior and MoO/sub 3/ is a low cost cathode material of interest.

  15. Rechargeable antimicrobial surface modification of polyethylene.

    PubMed

    Goddard, J M; Hotchkiss, J H

    2008-10-01

    Polyethylene films were surface modified, to incorporate amine and amide functionalities, and subsequently were evaluated for their ability to recharge the antimicrobial N-halamine structures after contact with sodium hypochlorite, a common food-approved sanitizer. Surfaces were tested for chlorine retention and release, as well as antimicrobial activity against microorganisms relevant to food quality and food safety, including Escherichia coli K-12, Pseudomonas fluorescens, Bacillus cereus, and Listeria monocytogenes. N-Halamine functionalized polyethylene exhibited chlorine rechargeability, maintaining 5 to 7 nmol/cm2 N-halamine structures for six successive charges. The N-halamine functionalized films achieved a 4-log reduction for all organisms tested and maintained a greater than 3-log reduction for four successive uses, suggesting that the modified polyethylene films are capable of providing rechargeable antimicrobial activity. The modified films exhibited antimicrobial activity in aqueous suspensions (P < 0.05) and reduced microbial growth in diluted broth (P < 0.05), suggesting the potential for biocidal action even in the presence of organic matter. Such a rechargeable antimicrobial surface could supplement existing cleaning and sanitation programs in food processing environments to reduce the adhesion, growth, and subsequent cross-contamination of food pathogens, as well as food spoilage organisms. PMID:18939750

  16. Rechargeable solid polymer electrolyte battery cell

    DOEpatents

    Skotheim, Terji

    1985-01-01

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

  17. Alloys of clathrate allotropes for rechargeable batteries

    DOEpatents

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

    2014-12-09

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

  18. Anodes for Rechargeable Lithium-Sulfur Batteries

    SciTech Connect

    Cao, Ruiguo; Xu, Wu; Lu, Dongping; Xiao, Jie; Zhang, Jiguang

    2015-04-10

    In this work, we will review the recent developments on the protection of Li metal anode in Li-S batteries. Various strategies used to minimize the corrosion of Li anode and reducing its impedance increase will be analyzed. Other potential anodes used in sulfur based rechargeable batteries will also be discussed.

  19. Anode for rechargeable ambient temperature lithium cells

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  20. Recharging Our Sense of Idealism: Concluding Thoughts

    ERIC Educational Resources Information Center

    D'Andrea, Michael; Dollarhide, Colette T.

    2011-01-01

    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…

  1. Focused Recharge in a Theoretical Raingarden

    NASA Astrophysics Data System (ADS)

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

    2001-05-01

    Traditional stormwater management, which relies heavily on detention, does not mitigate groundwater depletion resulting from groundwater pumping and loss of groundwater recharge. In recent years there has been increasing interest in the use of practices, such as raingardens, that encourage infiltration of stormwater as a means of mitigating groundwater impacts. These can be particularly effective when infiltration is focused in order to maximize groundwater recharge. However, traditional hydrologic models are not well suited to describe focused infiltration. We have developed a model of focused recharge that can be applied in the design and evaluation of raingardens. The rain garden is represented by three homogeneous layers of soil. The upper layer represents the root zone. The middle layer is a high conductivity layer that provides water storage. The lower layer represents the urban soil, which may restrict water flow. To continuously simulate recharge, runoff and evapotranspiration during the wet and dry periods, a Richards equation is used to estimate soil water movement. Runoff from the garden is approximated by a weir equation, assuming a maximum ponding depth of 15 cm. Evapotranspiration is based on the Priestley & Taylor model, taking into account the partition of radiation through the plant canopy and the available soil water. A fully implicit finite difference approach is used to solve the model equation, with a modified Picard iteration for mass balancing. Results of the raingarden water budget will be presented for long-term continuous simulations.

  2. Regional Analysis of Ground-Water Recharge

    USGS Publications Warehouse

    Flint, Lorraine E.; Flint, Alan L.

    2007-01-01

    A modeling analysis of runoff and ground-water recharge for the arid and semiarid southwestern United States was performed to investigate the interactions of climate and other controlling factors and to place the eight study-site investigations into a regional context. A distributed-parameter water-balance model (the Basin Characterization Model, or BCM) was used in the analysis. Data requirements of the BCM included digital representations of topography, soils, geology, and vegetation, together with monthly time-series of precipitation and air-temperature data. Time-series of potential evapotranspiration were generated by using a submodel for solar radiation, taking into account topographic shading, cloudiness, and vegetation density. Snowpack accumulation and melting were modeled using precipitation and air-temperature data. Amounts of water available for runoff and ground-water recharge were calculated on the basis of water-budget considerations by using measured- and generated-meteorologic time series together with estimates of soil-water storage and saturated hydraulic conductivity of subsoil geologic units. Calculations were made on a computational grid with a horizontal resolution of about 270 meters for the entire 1,033,840 square-kilometer study area. The modeling analysis was composed of 194 basins, including the eight basins containing ground-water recharge-site investigations. For each grid cell, the BCM computed monthly values of potential evapotranspiration, soil-water storage, in-place ground-water recharge, and runoff (potential stream flow). A fixed percentage of runoff was assumed to become recharge beneath channels operating at a finer resolution than the computational grid of the BCM. Monthly precipitation and temperature data from 1941 to 2004 were used to explore climatic variability in runoff and ground-water recharge. The selected approach provided a framework for classifying study-site basins with respect to climate and dominant recharge processes. The average climate for all 194 basins ranged from hyperarid to humid, with arid and semiarid basins predominating (fig. 6, chapter A, this volume). Four of the 194 basins had an aridity index of dry subhumid; two of the basins were humid. Of the eight recharge-study sites, six were in semiarid basins, and two were in arid basins. Average-annual potential evapotranspiration showed a regional gradient from less than 1 m/yr in the northeastern part of the study area to more than 2 m/yr in the southwestern part of the study area. Average-annual precipitation was lowest in the two arid-site basins and highest in the two study-site basins in southern Arizona. The relative amount of runoff to in-place recharge varied throughout the study area, reflecting differences primarily in soil water-holding capacity, saturated hydraulic conductivity of subsoil materials, and snowpack dynamics. Climatic forcing expressed in El Ni?o and Pacific Decadal Oscillation indices strongly influenced the generation of precipitation throughout the study area. Positive values of both indices correlated with the highest amounts of runoff and ground-water recharge.

  3. Ductile nappe stacking and refolding in the Cycladic Blueschist Unit: insights from Sifnos Island (south Aegean Sea)

    NASA Astrophysics Data System (ADS)

    Aravadinou, Eirini; Xypolias, Paraskevas; Chatzaras, Vasileios; Iliopoulos, Ioannis; Gerogiannis, Nikolaos

    2015-10-01

    New geological and structural mapping combined with kinematic and amphibole chemistry analyses is used to investigate the deformation history of the Cycladic Blueschist Unit (CBU) on Sifnos Island (Cyclades, Aegean Sea). We concentrate on north Sifnos, an area characterized by exceptionally well-preserved eclogites and blueschists. Our data show that the early, main phase (D2) of ductile deformation in the CBU occurred synchronous with the transition from prograde to close-to-peak retrograde conditions. This deformation phase took place at middle Eocene and is related to ESE-directed thrusting that emplaced the metavolcano-sedimentary subunit over the Marble subunit. The subsequent exhumation-related (D3) deformation is characterized by gently NE-plunging folds and NE-directed contractional shear zones that formed parallel to the axial planes of folds. NE-directed shearing occurred under blueschist and transitional blueschist-/greenschist-facies conditions during late Eocene-Oligocene and caused the restacking of the early nappe pile. We suggest that a mechanism of ductile extrusion of the CBU in a tectonic setting of net compression could explain better the recorded exhumation-related deformation than a mechanism of syn- and post-orogenic extension. Our new kinematic results in combination with previous works in the Cyclades area reveal a regional scale change in tectonic transport direction from (W)NW-(E)SE at Late Cretaceous-middle Eocene to (E)NE-(W)SW at late Eocene-Oligocene times. The observed change in transport direction may be governed by the relative motion of Africa with respect to Europe during Alpine orogeny.

  4. Sedimentary evolution of the siliciclastic Aptian-Albian Massylian flysch of the Chouamat Nappe (central Rif, Morocco)

    NASA Astrophysics Data System (ADS)

    El Talibi, Hajar; Zaghloul, Mohamed Najib; Perri, Francesco; Aboumaria, Khadija; Rossi, Abdelhamid; El Moussaoui, Said

    2014-12-01

    Sandstone petrography and geochemistry (major, trace and rare earth elements) of the Aptian-Albian siliciclastic Massylian flysch from the Chouamat Nappe (central Rif Morocco) are used to highlight the chemical weathering conditions in the source area and to infer their provenance. Petrographic studies show that the studied samples are mostly quartzarenite, sublitharenite and subarkose generally composed of quartz (up to 99%), K-feldspar (less than 5%) and scarce fragments of sedimentary rocks. The samples plot in the continental block provenance field of the QtFLt diagram. Thus, the compositional maturity of analyzed sandstones is typical of cratonic environments. The sandstone samples shows high SiO2 content (up to 96%) and strong depletion in mobile components such as Na2O, CaO as well as in ferromagnesian minerals, which are mainly related to intense chemical weathering processes in the source area, as confirmed by high Chemical Index of Alteration values (mean = 79.8). Recycling is shown by the Th/Sc vs. Zr/Sc plot, where the studied sandstones fall along a trend involving zircon addition and thus sediment recycling. Several geochemical ratios, such as La/Sc, Th/Sc, Th/Co and Th/Cr, of the studied samples are similar to those of Post-Archean Australian Shales and of the Upper Continental Crust, and suggest a provenance from source area(s) mainly composed of plutonic and felsic metasedimentary and sedimentary rocks, which were most probably the basement rocks of the adjacent African plate. These source rocks are related to a large cratonic source region of Eburnean and Pan-African belts, Precambrian (?) and/or Variscan basements of the southeastern margin of the African plate.

  5. Elastic anisotropy and borehole stress estimation in the Seve Nappe Complex from the COSC-1 well, Åre, Sweden.

    NASA Astrophysics Data System (ADS)

    Wenning, Quinn; Almquist, Bjarne; Ask, Maria; Schmitt, Douglas R.; Zappone, Alba

    2015-04-01

    The Caledonian orogeny, preserved in Scandinavia and Greenland, began with the closure of the Iapetus Ocean and culminated in the collision of Baltica and Laurentia cratons during the middle Paleozoic. The COSC scientific drilling project aims at understanding the crustal structure and composition of the Scandinavian Caledonides. The first well of the dual phase drilling program, completed in Summer of 2014, drilled through ~2.5 km of the Seve Nappe Complex near the town of Åre, Sweden. Newly acquired drill core and borehole logs provide fresh core material for physical rock property measurements and in-situ stress determination. This contribution presents preliminary data on compressional and shear wave ultrasonic velocities (Vp, Vs) determined from laboratory measurements on drill cores, together with in-situ stress orientation analysis using image logs from the first borehole of the Collisional Orogeny in the Scandinavian Caledonides project (COSC-1). An hydrostatically oil pressurized apparatus is used to test the ultrasonic Vp and Vs on three orthogonally cut samples of amphibolite, calcium bearing and felsic gneiss, meta-gabbro, and mylonitic schist from drill core. We measure directional anisotropy variability for each lithology using one sample cut perpendicular to the foliation and two additional plugs cut parallel to the foliation with one parallel to the lineation and the other perpendicular. Measurements are performed using the pulse transmission technique on samples subjected to hydrostatic pressure from 1-350 MPa at dry conditions. We present preliminary results relating Vp and Vs anisotropy to geologic units and degree of deformation. Additionally, we use acoustic borehole televiewer logs to estimate the horizontal stress orientation making use of well developed techniques for observed borehole breakouts (compressive failure) and drilling induced fractures (tensile failure). Preliminary observations show that very few drilling-induced tensile fractures are produced, and that borehole breakouts are episodic and suggests a NE-SW minimum horizontal stress direction

  6. New evidence of a magmatic arc in the southern Brasília Belt, Brazil: The Serra da Água Limpa batholith (Socorro-Guaxupé Nappe)

    NASA Astrophysics Data System (ADS)

    Vinagre, Rodrigo; Trouw, Rudolph A. J.; Mendes, Julio Cezar; Duffles, Patrícia; Peternel, Rodrigo; Matos, Gabriel

    2014-10-01

    This paper presents a detailed description of the Neoproterozoic Serra da Água Limpa batholith (SALB) and the interpretation of its genesis. The batholith, located along the border of the states of Minas Gerais and São Paulo, was involved in the Socorro-Guaxupé Nappe, a tectonic unit that integrates the southern Brasília Belt. The tectonic evolution of this nappe is related to the convergence and subsequent collision between the Paranapanema paleocontinent, representing the upper plate, with the São Francisco paleocontinent, resulting in the construction of the southern Brasília Belt. The active margin of the Paranapanema paleocontinent developed during the pre-collisional stage a magmatic arc composed of batholithic igneous bodies. The Socorro-Guaxupé Nappe represents this active margin and SALB is one of those bodies. U-Pb dating (Laser Ablation, LA-ICP-MS) in zircon was performed in five samples of SALB. The results are as follows: sample RDTM 62, 667 ± 10 Ma; RDPA 44, 645 ± 5 Ma; RDPA 46, 630 ± 12 Ma; VAC 10, 631 ± 7 Ma and RDIT 41, 635 ± 8 Ma. These ages indicate that the body crystallized between 670 and 630 Ma, with predominance of ages in the interval 645-630 Ma, demonstrating that the magmatic event that formed the arc lasted at least 40 myr. Younger ages, measured in rims of zircon grains, mainly in the range 625-600 Ma were interpreted as metamorphic ages. The lithogeochemical analyses indicate that the I-type rocks of the Serra da Água Limpa batholith belong to the high K calc-alkaline series, and are metaluminous to slightly peraluminous. Tectonic environment diagrams also indicate that the batholith was produced in a volcanic arc setting which is confirmed by negative anomalies of elements of high ionic potential (HFS) in multi-element diagrams. Whole rock Sm-Nd isotope analyses show highly negative ?Nd values (-12 to -7), indicating significant crustal contamination or origin of the magma by melting of enriched lower crust.

  7. The impact of Outer Western Carpathian nappe tectonics on the recent stress-strain state in the Upper Silesian Coal Basin (Moravosilesian Zone, Bohemian Massif)

    NASA Astrophysics Data System (ADS)

    Ptá?ek, Ji?í; Grygar, Radomír; Koní?ek, Petr; Waclawik, Petr

    2012-02-01

    The Upper Silesian Coal Basin (USCB) represents a typical foreland basin developed during the Variscan orogenic phase of the Late Carboniferous. Later, during the Alpine orogeny the Outer Western Carpathian nappes were thrust over the post-Variscan foreland, to which the USCB belongs. Due to this complex tectonic history, redistribution of stress fields occurred in the post-Variscan basement. Furthermore, post-Variscan denudation processes probably also contributed to recent stress regimes. Nevertheless, the impact of the West Carpathian orogeny can be regarded as the most significant influence. The in-situ measurement of recent stress fields in deposits of the Karviná Formation of the USCB and structural analysis of the Czech part of the USCB, has focused on verification of the structure and stress interference of the Carpathian nappes and post-Variscan foreland basement. In the southernmost part of the Karviná Subbasin, the easternmost domain of the USCB, situated in the apical zone of the Variscan accretionary wedge, hydrofracturing and overcoring stress measurements have been recorded in coal seams from selected coal mines. The data have been supplemented by interpretation of focal mechanism solutions of mine induced seismic events. Measurements of recent in-situ stress regimes in the Karviná Formation of the USCB indicate a dominant generally NW-SE orientation of the maximum horizontal compression stress. The results demonstrate that the stress-strain regime in the Karviná Formation in the Variscan Upper Carboniferous basement is significantly influenced by the stress field along the Outer Western Carpathian nappes front. Besides improving our understanding of recent regional stress fields within an area of mutual structural-tectonic interference by both the Variscan and Alpine orogenies, the measured data may contribute to more optimal and safer mining activities in the coal basin.

  8. Rechargeable infection-responsive antifungal denture materials.

    PubMed

    Cao, Z; Sun, X; Yeh, C-K; Sun, Y

    2010-12-01

    Candida-associated denture stomatitis (CADS) is a significant clinical concern. We developed rechargeable infection-responsive antifungal denture materials for potentially managing the disease. Polymethacrylic acid (PMAA) was covalently bound onto diurethane dimethacrylate denture resins in the curing step. The PMAA resins bound cationic antifungal drugs such as miconazole and chlorhexidine digluconate (CG) through ionic interactions. The anticandidal activities of the drug-containing PMAA-resin discs were sustained for a prolonged period of time (weeks and months). Drug release was much faster at acidic conditions (pH 5) than at pH 7. Drugs bound to the denture materials could be "washed out" by treatment with EDTA, and the drug-depleted resins could be recharged with the same or a different class of anticandidal drugs. These results suggest clinical potential of the newly developed antifungal denture materials in the management of CADS and other infectious conditions. PMID:20940361

  9. Urban Network Implications On Groundwater Recharge

    NASA Astrophysics Data System (ADS)

    Duque, J.; Chambel, A.

    Urbanisation has had a major impact on groundwater beneath Évora city (South Portu- gal). Évora is an ancient city and the growth of impermeable areas due to urbanisation has lead to a reduction in groundwater recharge. The specific type of residential land use has a major influence on the permeability of the recharge area. The use of ground- water inside the city of Évora is largely for particular gardening and small farming supplies. In the oldest part of the city (inside of the city walls) there is little use of groundwater, while in the part of the city outside the city walls usage is more effec- tive. This study provides evidence that the municipality or particular people can use groundwater to irrigate the majority gardens, instead of using cleaned water from the Monte Novo Dam. This will also provide a solution to the control of pollution that occurs due to losses from the sewerage system of the city.

  10. Rechargeable Infection-responsive Antifungal Denture Materials

    PubMed Central

    Cao, Z.; Sun, X.; Yeh, C.-K.; Sun, Y.

    2010-01-01

    Candida-associated denture stomatitis (CADS) is a significant clinical concern. We developed rechargeable infection-responsive antifungal denture materials for potentially managing the disease. Polymethacrylic acid (PMAA) was covalently bound onto diurethane dimethacrylate denture resins in the curing step. The PMAA resins bound cationic antifungal drugs such as miconazole and chlorhexidine digluconate (CG) through ionic interactions. The anticandidal activities of the drug-containing PMAA-resin discs were sustained for a prolonged period of time (weeks and months). Drug release was much faster at acidic conditions (pH 5) than at pH 7. Drugs bound to the denture materials could be “washed out” by treatment with EDTA, and the drug-depleted resins could be recharged with the same or a different class of anticandidal drugs. These results suggest clinical potential of the newly developed antifungal denture materials in the management of CADS and other infectious conditions. PMID:20940361

  11. Nanocomposite polymer electrolyte for rechargeable magnesium batteries

    SciTech Connect

    Shao, Yuyan; Rajput, Nav Nidhi; Hu, Jian Z.; Hu, Mary Y.; Liu, Tianbiao L.; Wei, Zhehao; Gu, Meng; Deng, Xuchu; Xu, Suochang; Han, Kee Sung; Wang, Jiulin; Nie, Zimin; Li, Guosheng; Zavadil, K.; Xiao, Jie; Wang, Chong M.; Henderson, Wesley A.; Zhang, Jiguang; Wang, Yong; Mueller, Karl T.; Persson, Kristin A.; Liu, Jun

    2015-03-01

    Nanocomposite polymer electrolytes present new opportunities for rechargeable magnesium batteries. However, few polymer electrolytes have demonstrated reversible Mg deposition/dissolution and those that have still contain volatile liquids such as tetrahydrofuran (THF). In this work, we report a nanocomposite polymer electrolyte based on poly(ethylene oxide) (PEO), Mg(BH4)2 and MgO nanoparticles for rechargeable Mg batteries. Cells with this electrolyte have a high coulombic efficiency of 98% for Mg plating/stripping and a high cycling stability. Through combined experiment-modeling investigations, a correlation between improved solvation of the salt and solvent chain length, chelation and oxygen denticity is established. Following the same trend, the nanocomposite polymer electrolyte is inferred to enhance the dissociation of the salt Mg(BH4)2 and thus improve the electrochemical performance. The insights and design metrics thus obtained may be used in nanocomposite electrolytes for other multivalent systems.

  12. Recharge monitoring in an interplaya setting

    SciTech Connect

    Scanlon, B.R.; Reedy, R.C.; Liang, J.

    1999-03-01

    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.

  13. A new rechargeable intelligent vehicle detection sensor

    NASA Astrophysics Data System (ADS)

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

    2005-01-01

    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.

  14. Artificial recharge of humic ground water.

    PubMed

    Alborzfar, M; Villumsen, A; Grøn, C

    2001-01-01

    The purpose of this study was to investigate the efficiency of soil in removing natural organic matter from humic ground waters using artificial recharge. The study site, in western Denmark, was a 10,000 ml football field of which 2,000 m2 served as an infiltration field. The impact of the artificial recharge was studied by monitoring the water level and the quality of the underlying shallow aquifer. The humic ground water contained mainly humic adds with an organic carbon (OC) concentration of 100 to 200 mg C L(-1). A total of 5,000 mS of humic ground water were sprinkled onto the infiltration field at an average rate of 4.25 mm h(-1). This resulted in a rise in the water table of the shallow aquifer. The organic matter concentration of the water in the shallow aquifer, however, remained below 2.7 mg C L(-1). The organic matter concentration of the pore water in the unsaturated zone was measured at the end of the experiment. The organic matter concentration of the pore water decreased from 105 mg C L(-1) at 0.5 m to 20 mg C L(-1) at 2.5 m under the infiltration field indicating that the soil removed the organic matter from the humic ground water. From these results we conclude that artificial recharge is a possible method for humic ground water treatment. PMID:11215654

  15. An ultrafast rechargeable aluminium-ion battery

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  16. A regression model to estimate regional ground water recharge

    USGS Publications Warehouse

    Lorenz, D.L.; Delin, G.N.

    2007-01-01

    A regional regression model was developed to estimate the spatial distribution of ground water recharge in subhumid regions. The regional regression recharge (RRR) model was based on a regression of basin-wide estimates of recharge from surface water drainage basins, precipitation, growing degree days (GDD), and average basin specific yield (SY). Decadal average recharge, precipitation, and GDD were used in the RRR model. The RRR estimates were derived from analysis of stream base flow using a computer program that was based on the Rorabaugh method. As expected, there was a strong correlation between recharge and precipitation. The model was applied to statewide data in Minnesota. Where precipitation was least in the western and northwestern parts of the state (50 to 65 cm/year), recharge computed by the RRR model also was lowest (0 to 5 cm/year). A strong correlation also exists between recharge and SY. SY was least in areas where glacial lake clay occurs, primarily in the northwest part of the state; recharge estimates in these areas were in the 0- to 5-cm/year range. In sand-plain areas where SY is greatest, recharge estimates were in the 15- to 29-cm/year range on the basis of the RRR model. Recharge estimates that were based on the RRR model compared favorably with estimates made on the basis of other methods. The RRR model can be applied in other subhumid regions where region wide data sets of precipitation, streamflow, GDD, and soils data are available.

  17. Shear zone broadening driven by metasomatism: an example from the Roffna metarhyolite (Suretta nappe, eastern central Alps)

    NASA Astrophysics Data System (ADS)

    Poilvet, J.-C.; Goncalves, P.; Marquer, D.

    2012-04-01

    Ductile shear zones in continental crust play a critical role in the accommodation of deformation at crustal scale. They are also pathways for fluid and therefore the loci of metamorphic and metasomatic reactions. These fluid-rock interactions (reactions and metasomatism) control the behaviour of the shear zone and may be one of the driving force for the development of the shear zone and its lateral propagation (widening). Our goal in this contribution is to quantify the role of these chemical processes on the shear zone formation. The present study focuses on shear zones in the Roffna metarhyolite, in the Suretta nappe (Penninic Domain, Eastern Central Alps). This early Permian massif intruded the older basement and was affected only by Alpine tectonics. The ductile deformation is characterized by a shear zone network from millimetric to plurimetric scale developed under blueschist facies conditions. Mass transfer results show gains in MgO, K2O and H2O coupled with losses in CaO and Na2O with increasing strain. The main mineralogical change along the gradient is the growth of phengite and quartz at the expense of K-Feldspar and plagioclases. The appearance of a small amount of epidote and a small decrease in the amount of biotite is also observed. In our conceptual model of shear zone formation, the ultramylonite is assumed to be produced by infiltration metasomatism. In contrast the intermediate rocks between the protolith and the highest strain rock is assumed to be the result of diffusion metasomatism. Therefore the amount of lateral propagation is controlled by the kinetics of diffusion and equilibration of the host rock. To test this hypothesis we have compared shear zones with different thickness which should represent various degree of equilibration of the host rock at the conditions of the deformation and fluid-rock interactions. Using a suite of PT and chemical potential computed phase diagrams, we are able to model the reaction path involved during the equilibration process between the host rock and the highest strain zone. Our work provide new insights into the role of chemical processes on the formation of shear zone.

  18. Generator and rechargeable battery system for pedal powered vehicles

    SciTech Connect

    Ryan, D.

    1985-11-26

    A generator and rechargeable battery system for use with pedal powered vehicles, such as bicycles, and where either the generator or battery can intermittently power a load such as a lighting system of the vehicle in one mode of operation, and in which the generator can recharge the battery in another mode of operation. A simple selection switch which is manually operable by the operator of the vehicle enables selection between powering of the load or recharging of the battery.

  19. Making Li-air batteries rechargeable: material challenges

    SciTech Connect

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

    2013-02-25

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  1. Geophysical Methods for Investigating Ground-Water Recharge

    USGS Publications Warehouse

    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

    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.

  2. An ultrafast rechargeable aluminium-ion battery.

    PubMed

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

    2015-04-16

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

  3. Experimental survey of rechargeable alkaline zinc electrodes

    NASA Astrophysics Data System (ADS)

    Binder, L.; Odar, W.

    1984-09-01

    Rechargeable alkaline zinc-air cells and zinc-manganese dioxide cells need zinc electrodes working for at least 100 cycles under anode limiting conditions. The discharge of the manganese dioxide cathode especially must be limited to a definite fraction (1/3) of its available capacity to obtain a good cycle life. This study proposes a new test cell for investigations on pasted alkaline zinc powder electrodes. When, following experimentation, the value of the construction was established, a series of different electrode mixtures was cycled. It was found that 100 full discharges could be obtained with a zinc utilization of about 30 percent in the final cycles.

  4. Glossary of testing terminology for rechargeable batteries

    SciTech Connect

    Butler, P.C.

    1988-10-01

    The Battery Test Working Task Force was formed in 1983 for the purpose of coordinating the evaluation of development rechargeable batteries by DOE-funded labs. The Task Force developed this glossary of testing terminology to improve the accuracy of communication and to permit meaningful comparisons of test results. It consists of a section of technical terms and a separate section of programmatic phrases and acronyms. The glossary emphasizes terms related to electric vehicle batteries due to the significant development and testing activities in this area. 8 refs.

  5. Evolution of strategies for modern rechargeable batteries.

    PubMed

    Goodenough, John B

    2013-05-21

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

  6. Organic Cathode Materials for Rechargeable Batteries

    SciTech Connect

    Cao, Ruiguo; Qian, Jiangfeng; Zhang, Jiguang; Xu, Wu

    2015-06-28

    This chapter will primarily focus on the advances made in recent years and specify the development of organic electrode materials for their applications in rechargeable lithium batteries, sodium batteries and redox flow batteries. Four various organic cathode materials, including conjugated carbonyl compounds, conducting polymers, organosulfides and free radical polymers, are introduced in terms of their electrochemical performances in these three battery systems. Fundamental issues related to the synthesis-structure-activity correlations, involved work principles in energy storage systems, and capacity fading mechanisms are also discussed.

  7. Thin-film Rechargeable Lithium Batteries

    DOE R&D Accomplishments Database

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

    1995-06-01

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

  8. Rechargeable lithium/polymer cathode batteries

    NASA Astrophysics Data System (ADS)

    Osaka, Tetsuya; Nakajima, Toshiki; Shiota, Koh; Owens, Boone B.

    1989-06-01

    Polypyrrole (PPy) and polyaniline (PAn) were investigated for cathode materials of rechargeable lithium batteries. PPy films prepared with PF6(-) anion and/or platinum substrate precoated with nitrile butadiene rubber (NBR) were excellent cathode materials because of rough and/or highly oriented film structure. PAn films were successfully prepared from non-aqueous propylene carbonate solution containing aniline, CF3COOH and lithium perchlorate. Its acidity strongly affects the anion doping-undoping behavior. The PAn cathode prepared in high acidic solution (e.g., 4:1 ratio of acid:aniline) gives the excellent battery performance.

  9. Using environmental isotopes in the study of the recharge-discharge mechanisms of the Yarmouk catchment area in Jordan

    NASA Astrophysics Data System (ADS)

    Salameh, Elias

    The recharge sources, the flow mechanisms and discharge areas of the different groundwater bodies underlying the Yarmouk River catchment area in Jordan, have, until now, not been adequately explained, although a wide range of hydrological, hydrogeological, and hydrochemical studies have been done. Along the Jordanian part of the catchment area of the Yarmouk River, groundwater issues from different aquifers with a variety of chemistries and types within the same aquifer and in between the different aquifers. Conventional recharge/discharge mechanisms, water balances and chemical analyses did not adequately explain the chemical variations and the different water types found in the area. Applying environmental isotopic tools combined with their altitude effects due to topographic variations (250-1,300 m a.s.l. within a distance of 20 km), and taking into consideration re-evaporation effects on the isotopic depletion and enrichment of rainwater, has greatly helped in understanding the recharge discharge mechanisms of the different aquifers. Precipitation along the highlands of an average of 600 mm/year is found to be depleted in its isotopic content of ?O18 = -7.0 to -7.26 and ?D = -32.2 to -33.28, whereas that of the Jordan Valley of 350 mm/year is highly enriched in isotopes with ?O18 = -4.06 and ?D = -14.5. The groundwater recharged along the highlands is depleted in isotopes (?O18 = -6, ?D = -30), groundwater at the intermediate elevations is enriched (?O18 = -5, ?D = -23) and that of the Jordan Valley aquifers containing meteoric water is highly enriched (?O18 -3.8, ?D = -18). The deep aquifers in the Jordan Valley foothills are depleted in isotopes (?O18 -18 = -6, ?D = -30) and resemble those of the highland aquifers. Only through using isotopes as a tool, were the sources of the different groundwater bodies and recharge and discharge mechanisms unambiguously explained. It was found that recharge takes place all over the study area and produces groundwater, which, from the highlands towards the Jordan Valley, shows increasing enrichment in isotopes. The highlands aquifer, with its groundwater depleted in isotopes, becomes confined towards the Jordan Valley; and, due to its confining pressure, leaks water upwards into the overlying aquifers causing their water to become less enriched in isotopes. Water depleted in its isotopic composition also seeps upward to the ground surface at the mountain foothills through faults and fissures. Les zones de recharge, les mécanismes d'écoulement et les zones de décharges des différentes masses d'eau souterraine sous le bassin versant de la rivière Yarmouk en Jordanie, étaient expliquées de manière ambiguë par les seuls outils isotopiques. Le long de la parti Jordanienne du bassin versant de la rivière Yarmouk l'eau souterraine provient de différents aquifères et se distinguent par leur type et leur composition chimique, selon que l'eau provient du même ou des différents aquifères. Les mécanismes conventionnels de recharge et de décharge, bilan hydrologique ne donnaient pas d'explications satisfaisantes concernant les variations chimiques et les différents types d'eau. En appliquant les isotopes environnementaux combinés aux effets de l'altitude sur les variations des teneurs isotopiques (l'altitude varie de 250 à 1,300 m sur une distance de 20 km.) et en prenant en considération les effets de ré-évaporation sur l'appauvrissement et l'enrichissement isotopique des eaux pluviales ont fortement contribués à une meilleure compréhension des mécanismes de recharge des différents aquifères. Les précipitations annuelles sont comprises entre 600 mm dans les zones en altitude et 350 mm dans la vallée de la Jordanie. Les écoulements de l'eau souterraine sont dirigés des zones en altitude vers la vallée de la Jordanie. Les eaux souterraines des zones en altitude sont isotopiquement appauvries (?O18 = -6, ?D = -30), les eaux souterraines des zones de moyenne altitude sont enrichies (?O18 = -5, ?D = -23) et les eaux de la vallée très enrichies (?O18 -3.8, ?D = -18). Les aquifers profonds dans la vallée de la Jordanie sont appauvris (?O18 -18 = -6, ?D = -30) et se confondent avec les eaux des zones situées en altitude. En appliquant uniquement les isotopes environnementaux comme des outils de compréhension des phénomènes hydrogéologiques, la source des différentes masses d'eau souterraines, les mécanismes de la recharge et de la décharge pourraient être expliqués de manière ambiguë. Las fuentes de recarga, los mecanismos de flujo y las áreas de descarga de los diferentes cuerpos de agua subterránea que subyacen el área de la cuenca del Río Yarmouk en Jordania, se han explicado de manera no ambigua únicamente mediante la aplicación de los isótopos como herramienta. A lo largo de la parte Jordana del área de la cuenca del Río Yarmouk el agua subterránea emerge de diferentes acuíferos con una variedad de tipos y composiciones, ya sea que provengan del mismo acuífero o de diferentes acuíferos. Los mecanismos convencionales de recarga/descarga, balances hídricos y variaciones químicas no han podido explicar las variaciones químicas y los diferentes tipos de aguas. La aplicación de herramientas de isótopos ambientales combinadas con los efectos de altitud derivados de variaciones topográficas (250 hasta 1,300 m s.n.m. en una distancia de 20 km) y tomando en consideración los efectos de re-evaporación en el empobrecimiento de isótopos y enriquecimiento del agua de lluvia han ayudado fuertemente en el entendimiento de los mecanismos de recarga/descarga de los diferentes acuíferos. La precipitación en el área varía de 600 mm/año, a lo largo de las tierras altas, a 350 mm/año en el área del Valle Jordán. El flujo de agua subterránea ocurre de las tierras altas hacia el Valle Jordán. El agua subterránea de las tierras altas está empobrecida en isótopos (?O18 = -6, ?D = -30), el agua subterránea de elevaciones intermedias está enriquecida (?O18 = -5, ?D = -23), y el agua de los acuíferos del Valle Jordan contiene agua meteórica que se encuentra altamente enriquecida (?O18 = -3.8, ?D = -18). Los acuíferos profundos que se localizan al pie de las tierras altas del Valle Jordán están empobrecidos en isótopos (?O18 = -6, ?D = -30) y son similares a los acuíferos de las tierras altas. Solo al aplicar los isótopos ambientales como herramienta pudo explicarse de manera inequívoca las fuentes de los diferentes cuerpos de agua subterránea y los mecanismos de recarga y descarga.

  10. Rheologie des Polymeres Charges

    NASA Astrophysics Data System (ADS)

    Lepez, Olivier

    Une etude des proprietes rheologiques en ecoulement oscillatoire et en ecoulement transitoire a ete realisee sur des suspensions de particules spheriques dans des solutions de polymere d'une part et dans des polymeres a l'etat fondu d'autre part. Une attention particuliere a ete portee sur l'influence des parametres suivants sur les proprietes en ecoulement de ces fluides complexes: nature du fluide suspendant, fraction volumique en particule, temperature. Apres analyse des resultats, de nouveaux modeles empiriques ont ete proposes afin de predire l'allure des courbes d'ecoulement de ces suspensions en cisaillement oscillatoire. Enfin, certaines analogies entre les proprietes visqueuses et viscoelastiques des suspensions dans les deux milieux mentionnes precedemment ont ete discutees.

  11. Sediment and microbial fouling of experimental groundwater recharge trenches

    NASA Astrophysics Data System (ADS)

    Warner, James W.; Gates, Timothy K.; Namvargolian, Reza; Miller, Paul; Comes, Gregory

    1994-04-01

    A common method of recharging groundwater is by the use of injection wells and/or recharge trenches. With time the recharge capacities of the wells/trenches progressively decline. Deposition of suspended fines in the recharge water and growth of microorganisms in the aquifer are common causes of this decline. This paper presents an investigation of the relative significance of these two factors under controlled laboratory conditions. Large-scale physical models of recharge trenches were conducted in the laboratory to monitor the decline with time of the recharge capacity under controlled conditions. The physical models consisted of four hydraulically separate cells in which six different experiments were conducted. In three of the experiments microorganism were added as an inoculant. A nutrient and carbon fine solution was constantly injected into the influent stream entering through the inflow pipe. Both carbon fines and microorganisms caused plugging of the model recharge trenches in the laboratory. However, initialy the microbes appeared to have a beneficial effect by hindering the transport of the carbon fines from the gravel pack in the trench. Later the microbes contributed to the plugging of the gravel pack. A significant correlation was determined between the extent of carbon fine deposition and microbial growth. In the experiment using a biodegradable slurry, microbial growth did not affect the recharge capacity of the trench. One laboratory experiment involved the introduction of silt as a source of sediment fines to the model recharge trench. This experiment simulated conditions often found in the field when no carbon fine adsoprtion system is used and natural surface water is recharged into aquifer. This research will be useful in understanding the relative importance of factors contributing to the decline of recharge capacity observed in the field.

  12. Artificial recharge of groundwater and its role in water management

    USGS Publications Warehouse

    Kimrey, J.O.

    1989-01-01

    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.

  13. Rechargeable Thin-film Lithium Batteries

    DOE R&D Accomplishments Database

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

    1993-08-01

    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.

  14. Lithium Metal Anodes for Rechargeable Batteries

    SciTech Connect

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

    2013-10-29

    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.

  15. Prototype systems for rechargeable magnesium batteries.

    PubMed

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

    2000-10-12

    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

  16. 77 FR 20688 - Seventh Meeting: RTCA Special Committee 225, Rechargeable Lithium Batteries and Battery Systems...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-05

    ... Federal Aviation Administration Seventh Meeting: RTCA Special Committee 225, Rechargeable Lithium.... Department of Transportation (DOT). ACTION: Notice of RTCA Special Committee 225, Rechargeable Lithium... public of the seventh meeting of RTCA Special Committee 225, Rechargeable Lithium Batteries and...

  17. 77 FR 8325 - Sixth Meeting: RTCA Special Committee 225, Rechargeable Lithium Batteries and Battery Systems...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-14

    ... TRANSPORTATION Federal Aviation Administration Sixth Meeting: RTCA Special Committee 225, Rechargeable Lithium.... Department of Transportation (DOT). ACTION: Notice of RTCA Special Committee 225, Rechargeable Lithium... public of the sixth meeting of RTCA Special Committee 225, Rechargeable Lithium Batteries and...

  18. Des ballons pour demain

    NASA Astrophysics Data System (ADS)

    Régipa, R.

    A partir d'une théorie sur la détermination des formes et des contraintes globales d'un ballon de révolution, ou s'en rapprochant, une nouvelle famille de ballons a été définie. Les ballons actuels, dits de ``forme naturelle'', sont calculés en général pour une tension circonférencielle nulle. Ainsi, pour une mission donnée, la tension longitudinale et la forme de l'enveloppe sont strictement imposées. Les ballons de la nouvelle génération sont globalement cylindriques et leurs pôles sont réunis par un câble axial, chargé de transmettre une partie des efforts depuis le crochet (pôle inférieur), directement au pôle supérieur. De plus, la zone latérale cylindrique est soumise à un faible champ de tensions circonférencielles. Ainsi, deux paramètres permettent de faire évoluer la distribution des tensions et la forme de l'enveloppe: - la tension du câble de liaison entre pôles (ou la longueur de ce câble) - la tension circonférencielle moyenne désirée (ou le rayon du ballon). On peut donc calculer et réaliser: - soit des ballons de forme adaptée, comme les ballons à fond plat pour le bon fonctionnement des montgolfières infrarouge (projet MIR); - soit des ballons optimisés pour une bonne répartition des contraintes et une meilleure utilisation des matériaux d'enveloppe, pour l'ensemble des programmes stratosphériques. Il s'ensuit une économie sensible des coûts de fabrication, une fiabilité accrue du fonctionnement de ces ballons et une rendement opérationnel bien supérieur, permettant entre autres, d'envisager des vols à très haute altitude en matériaux très légers.

  19. Serpentinite slices within a tectonic zone at the base of the Juvavic nappe system in the Northern Calcareous Alps (Austria): characterization and origin

    NASA Astrophysics Data System (ADS)

    Boehm, Katharina; Schuster, Ralf; Wagreich, Michael; Koller, Friedrich; Wimmer-Frey, Ingeborg

    2014-05-01

    The investigated serpentinites are present in an ENE-WSW orientated tectonic zone at the base of Juvavic nappes (Northern Calcareous Alps), situated at the eastern margin of the Eastern Alps (Lower Austria). They form small tectonically squeezed slices, which are embedded in Permotriassic schists and Middle to Upper Triassic limestones. These serpentinites play an important, but not yet understood role in reconstructing Neotethys evolution, Alpine Orogeny and the correlation of Dinarides and Alps. The largest serpentinite body near to Unterhöflein is 400 to 100 meters in size and was investigated by mineralogical (XRD) and petrological/geochemical (XRF) methods. The primary mineral composition is olivine + orthopyroxene + clinopyroxene + chrome spinel. Pseudomorphs of pyroxenes are visible macroscopically, but almost all primary minerals are replaced by serpentine minerals. Former olivine is converted to chrysotile minerals, which show typical reticulate textures, orthopyroxene turned into lizardite pseudomorphs and chrome spinel is almost completely altered to magnetite. Major contents of chrysotile-?, chrysotile-? and lizardite and minor antigorite, as well as secondary minerals like talc, chlorite and hydrogrossular were identified with XRD. Results from whole rock geochemistry indicate harzburgitic precursor rocks for the serpentinites. According to the low antigorite content, the rocks have only a weak metamorphic imprint and therefore an obduction rather than a subduction history is likely. This leads to the assumption that these serpentinites possibly originate from the Neotethys and not from the Penninic oceanic realm. Further, the tectonic position of the serpentinite slices is in close vicinity to sediments of the Meliata unit which also occur between Juvavic and underlying Tirolic nappe system (Mandl & Ondrejickova, 1993). Additionally, remnants from ophiolite nappes are found reworked into the surrounding Upper Cretaceous Gosau Group. In the latter also chrome spinel detritus is present. In contrast to the altered chrome spinels in the investigated serpentinites, the spinels from Gosau Group are well preserved and they show similarities to those of Dinaric Cretaceous basins, concerning their harzburgitic and lherzolitic sources (Stern & Wagreich, 2013). If the investigated serpentinites belong to obducted material from Neothetys oceanic realm, a tectonic model of a slab-tearing induced sinistral strike-slip zone could explain the position in the Eastern Alps. However, the relationship to other basic magmatic rocks from several other localities in similar positions, mostly occurring within evaporitic sediments of Permian Haselgebirge (Schorn et al., 2013), has to be clarified.

  20. Ophiolitic detritus in Kimmeridgian resedimented limestones and its provenance from an eroded obducted ophiolitic nappe stack south of the Northern Calcareous Alps (Austria)

    NASA Astrophysics Data System (ADS)

    Gawlick, Hans-Jürgen; Aubrecht, Roman; Schlagintweit, Felix; Missoni, Sigrid; Plašienka, Dušan

    2015-12-01

    The causes for the Middle to Late Jurassic tectonic processes in the Northern Calcareous Alps are still controversially discussed. There are several contrasting models for these processes, formerly designated "Jurassic gravitational tectonics". Whereas in the Dinarides or the Western Carpathians Jurassic ophiolite obduction and a Jurassic mountain building process with nappe thrusting is widely accepted, equivalent processes are still questioned for the Eastern Alps. For the Northern Calcareous Alps, an Early Cretaceous nappe thrusting process is widely favoured instead of a Jurassic one, obviously all other Jurassic features are nearly identical in the Northern Calcareous Alps, the Western Carpathians and the Dinarides. In contrast, the Jurassic basin evolutionary processes, as best documented in the Northern Calcareous Alps, were in recent times adopted to explain the Jurassic tectonic processes in the Carpathians and Dinarides. Whereas in the Western Carpathians Neotethys oceanic material is incorporated in the mélanges and in the Dinarides huge ophiolite nappes are preserved above the Jurassic basin fills and mélanges, Jurassic ophiolites or ophiolitic remains are not clearly documented in the Northern Calcareous Alps. Here we present chrome spinel analyses of ophiolitic detritic material from Kimmeridgian allodapic limestones in the central Northern Calcareous Alps. The Kimmeridgian age is proven by the occurrence of the benthic foraminifera Protopeneroplis striata and Labyrinthina mirabilis, the dasycladalean algae Salpingoporella pygmea, and the alga incertae sedis Pseudolithocodium carpathicum. From the geochemical composition the analysed spinels are pleonastes and show a dominance of Al-chromites (Fe3+-Cr3+-Al3+ diagram). In the Mg/(Mg+ Fe2+) vs. Cr/(Cr+ Al) diagram they can be classified as type II ophiolites and in the TiO2 vs. Al2O3 diagram they plot into the SSZ peridotite field. All together this points to a harzburgite provenance of the analysed spinels as known from the Jurassic suprasubduction ophiolites well preserved in the Dinarides/Albanides. These data clearly indicate Late Jurassic erosion of obducted ophiolites before their final sealing by the Late Jurassic-earliest Cretaceous carbonate platform pattern.

  1. Global synthesis of groundwater recharge in semiarid and arid regions

    USGS Publications Warehouse

    Scanlon, B.R.; Keese, K.E.; Flint, A.L.; Flint, L.E.; Gaye, C.B.; Edmunds, W.M.; Simmers, I.

    2006-01-01

    Global synthesis of the findings from ???140 recharge study areas in semiarid and arid regions provides important information on recharge rates, controls, and processes, which are critical for sustainable water development. Water resource evaluation, dryland salinity assessment (Australia), and radioactive waste disposal (US) are among the primary goals of many of these recharge studies. The chloride mass balance (CMB) technique is widely used to estimate recharge. Average recharge rates estimated over large areas (40-374000 km2) range from 0.2 to 35 mm year-1, representing 0.1-5% of long-term average annual precipitation. Extreme local variability in recharge, with rates up to ???720 m year-1, results from focussed recharge beneath ephemeral streams and lakes and preferential flow mostly in fractured systems. System response to climate variability and land use/land cover (LU/LC) changes is archived in unsaturated zone tracer profiles and in groundwater level fluctuations. Inter-annual climate variability related to El Nin??o Southern Oscillation (ENSO) results in up to three times higher recharge in regions within the SW US during periods of frequent El Nin??os (1977-1998) relative to periods dominated by La Nin??as (1941-1957). Enhanced recharge related to ENSO is also documented in Argentina. Climate variability at decadal to century scales recorded in chloride profiles in Africa results in recharge rates of 30 mm year-1 during the Sahel drought (1970-1986) to 150 mm year-1 during non-drought periods. Variations in climate at millennial scales in the SW US changed systems from recharge during the Pleistocene glacial period (??? 10 000 years ago) to discharge during the Holocene semiarid period. LU/LC changes such as deforestation in Australia increased recharge up to about 2 orders of magnitude. Changes from natural grassland and shrublands to dryland (rain-fed) agriculture altered systems from discharge (evapotranspiration, ET) to recharge in the SW US. The impact of LU change was much greater than climate variability in Niger (Africa), where replacement of savanna by crops increased recharge by about an order of magnitude even during severe droughts. Sensitivity of recharge to LU/LC changes suggests that recharge may be controlled through management of LU. In irrigated areas, recharge varies from 10 to 485 mm year-1, representing 1-25% of irrigation plus precipitation. However, irrigation pumpage in groundwater-fed irrigated areas greatly exceeds recharge rates, resulting in groundwater mining. Increased recharge related to cultivation has mobilized salts that accumulated in the unsaturated zone over millennia, resulting in widespread groundwater and surface water contamination, particularly in Australia. The synthesis of recharge rates provided in this study contains valuable information for developing sustainable groundwater resource programmes within the context of climate variability and LU/LC change. Copyright ?? 2006 John Wiley & Sons, Ltd.

  2. Global synthesis of groundwater recharge in semiarid and arid regions

    NASA Astrophysics Data System (ADS)

    Scanlon, Bridget R.; Keese, Kelley E.; Flint, Alan L.; Flint, Lorraine E.; Gaye, Cheikh B.; Edmunds, W. Michael; Simmers, Ian

    2006-10-01

    Global synthesis of the findings from 140 recharge study areas in semiarid and arid regions provides important information on recharge rates, controls, and processes, which are critical for sustainable water development. Water resource evaluation, dryland salinity assessment (Australia), and radioactive waste disposal (US) are among the primary goals of many of these recharge studies. The chloride mass balance (CMB) technique is widely used to estimate recharge. Average recharge rates estimated over large areas (40-374 000 km2) range from 0.2 to 35 mm year-1, representing 0.1-5% of long-term average annual precipitation. Extreme local variability in recharge, with rates up to 720 m year-1, results from focussed recharge beneath ephemeral streams and lakes and preferential flow mostly in fractured systems. System response to climate variability and land use/land cover (LU/LC) changes is archived in unsaturated zone tracer profiles and in groundwater level fluctuations. Inter-annual climate variability related to El Niño Southern Oscillation (ENSO) results in up to three times higher recharge in regions within the SW US during periods of frequent El Niños (1977-1998) relative to periods dominated by La Niñas (1941-1957). Enhanced recharge related to ENSO is also documented in Argentina. Climate variability at decadal to century scales recorded in chloride profiles in Africa results in recharge rates of 30 mm year-1 during the Sahel drought (1970-1986) to 150 mm year-1 during non-drought periods. Variations in climate at millennial scales in the SW US changed systems from recharge during the Pleistocene glacial period (10 000 years ago) to discharge during the Holocene semiarid period. LU/LC changes such as deforestation in Australia increased recharge up to about 2 orders of magnitude. Changes from natural grassland and shrublands to dryland (rain-fed) agriculture altered systems from discharge (evapotranspiration, ET) to recharge in the SW US. The impact of LU change was much greater than climate variability in Niger (Africa), where replacement of savanna by crops increased recharge by about an order of magnitude even during severe droughts. Sensitivity of recharge to LU/LC changes suggests that recharge may be controlled through management of LU. In irrigated areas, recharge varies from 10 to 485 mm year-1, representing 1-25% of irrigation plus precipitation. However, irrigation pumpage in groundwater-fed irrigated areas greatly exceeds recharge rates, resulting in groundwater mining. Increased recharge related to cultivation has mobilized salts that accumulated in the unsaturated zone over millennia, resulting in widespread groundwater and surface water contamination, particularly in Australia. The synthesis of recharge rates provided in this study contains valuable information for developing sustainable groundwater resource programmes within the context of climate variability and LU/LC change.

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

    NASA Astrophysics Data System (ADS)

    Alias, Nurhaswani; Mohamad, Ahmad Azmin

    2015-01-01

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

  4. Improved Recharge Estimation from Portable, Low-Cost Weather Stations.

    PubMed

    Holländer, Hartmut M; Wang, Zijian; Assefa, Kibreab A; Woodbury, Allan D

    2016-03-01

    Groundwater recharge estimation is a critical quantity for sustainable groundwater management. The feasibility and robustness of recharge estimation was evaluated using physical-based modeling procedures, and data from a low-cost weather station with remote sensor techniques in Southern Abbotsford, British Columbia, Canada. Recharge was determined using the Richards-based vadose zone hydrological model, HYDRUS-1D. The required meteorological data were recorded with a HOBO(TM) weather station for a short observation period (about 1 year) and an existing weather station (Abbotsford A) for long-term study purpose (27 years). Undisturbed soil cores were taken at two locations in the vicinity of the HOBO(TM) weather station. The derived soil hydraulic parameters were used to characterize the soil in the numerical model. Model performance was evaluated using observed soil moisture and soil temperature data obtained from subsurface remote sensors. A rigorous sensitivity analysis was used to test the robustness of the model. Recharge during the short observation period was estimated at 863 and 816 mm. The mean annual recharge was estimated at 848 and 859 mm/year based on a time series of 27 years. The relative ratio of annual recharge-precipitation varied from 43% to 69%. From a monthly recharge perspective, the majority (80%) of recharge due to precipitation occurred during the hydrologic winter period. The comparison of the recharge estimates with other studies indicates a good agreement. Furthermore, this method is able to predict transient recharge estimates, and can provide a reasonable tool for estimates on nutrient leaching that is often controlled by strong precipitation events and rapid infiltration of water and nitrate into the soil. PMID:26011672

  5. Nanocarbon networks for advanced rechargeable lithium batteries.

    PubMed

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

    2012-10-16

    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

  6. High-grade deformation in quartzo-feldspathic gneisses during the early Variscan exhumation of the Cabo Ortegal nappe, NW of Iberia

    NASA Astrophysics Data System (ADS)

    Fernández, F. J.; Llana-Fúnez, S.; Marcos, A.; Castiñeiras, P.; Valverde-Vaquero, P.

    2015-12-01

    High-grade highly deformed gneisses crop out continuously along the Masanteo peninsula in the Cabo Ortegal nappe (NW Spain). The rock sequence formed by quartzo-feldspathic gneisses and mafic rocks records two partial melting events: during the Early Ordovician (ca. 480-488 Ma.), at the base of the Qz-Fsp gneisses, and immediately after eclogization (ca. 390.4 ± 1.2 Ma), during its early Variscan exhumation. Despite the strain accumulated during their final exhumation in which a pervasive blastomylonitic S2 foliation was developed, primary sedimentary layering in Qz-Fsp gneisses is well preserved locally at the top of the sequence. This first stage of the exhumation process occurred in ~ 10 Ma, during which bulk flattening of the high-grade rock sequence was accommodated by anastomosing shear bands that evolved to planar shear zones. Strain was progressively localized along the boundaries of the migmatitic Qz-Fsp gneisses. A SE-vergent ductile thrust constitutes the base of gneisses, incorporating eclogite blocks-in-matrix. A NW-vergent detachment placed the metasedimentary Qz-Fsp gneisses over the migmatitic Qz-Fsp gneisses. A difference in metamorphic pressure of ca. 0.5 GPa is estimated between both gneissic units. The high-grade deformation reduced substantially the thickness of the gneissic rock sequence during the process of exhumation controlled by change in the strain direction and the progressive localization of strain. The combined movement of the top detachment and basal thrust resulted in an extrusion of the migmatites within the nappe, directed to the SE in current coordinates.

  7. Structure and U-Pb zircon geochronology of an Alpine nappe stack telescoped by extensional detachment faulting (Kulidzhik area, Eastern Rhodopes, Bulgaria)

    NASA Astrophysics Data System (ADS)

    Georgiev, Neven; Froitzheim, Nikolaus; Cherneva, Zlatka; Frei, Dirk; Grozdev, Valentin; Jahn-Awe, Silke; Nagel, Thorsten J.

    2016-01-01

    The Rhodope Metamorphic Complex is a stack of allochthons assembled during obduction, subduction, and collision processes from Jurassic to Paleogene and overprinted by extensional detachment faults since Middle Eocene. In the study area, the following nappes occur in superposition (from base to top): an orthogneiss-dominated unit (Unit I), garnet-bearing schist with amphibolite and serpentinite lenses (Unit II), greenschist, phyllite, and calcschist with reported Jurassic microfossils (Unit III), and muscovite-rich orthogneiss (Unit IV). U-Pb dating of zircons from a K-feldspar augengneiss (Unit I) yielded a protolith age of ca. 300 Ma. Garnet-bearing metasediment from Unit II yielded an age spectrum with distinct populations between 310 and 250 Ma (detrital), ca. 150 Ma, and ca. 69 Ma (the last two of high-grade metamorphic origin). An orthogneiss from Unit IV yielded a wide spectrum of ages. The youngest population gives a concordia age of 581 ± 5 Ma, interpreted as the age of the granitic protolith. Unit I represents the Lower Allochthon (Byala Reka-Kechros Dome), Unit II the Upper Allochthon (Krumovitsa-Kimi Unit), Unit III the Uppermost Allochthon (Circum-Rhodope Belt), and Unit IV a still higher, far-travelled unit of unknown provenance. Telescoping of the entire Rhodope nappe stack to a thickness of only a few 100 m is due to Late Eocene north directed extensional shearing along the newly defined Kulidzhik Detachment which is part of a major detachment system along the northern border of the Rhodopes. Older top-to-the south mylonites in Unit I indicate that Tertiary extension evolved from asymmetric (top-to-the-south) to symmetric (top-to-the-south and top-to-the-north), bivergent unroofing.

  8. A Wrench fault system and nappe emplacement in Southern Kenya and Northern Tanzania.- A key area for Pan-African continental collision in East Africa?

    NASA Astrophysics Data System (ADS)

    Bauernhofer, A.; Wallbrecher, E.; Hauzenberger, C.; Fritz, H.; Loizenbauer, J.; Hoinkes, G.; Muhongo, S.; Mathu, E.

    2003-04-01

    In the Voi Area of Southern Kenya, the granulite facies rocks of the Taita Hills and the Tsavo East National Park (Galana River) can be divided into three structural domains: The Galana-East unit consists of an intercalation of flat lying metapelites and marbles of continental margin origin. These metasediments can be traced further east to the Umba Steppe (Between Mombasa and Tanga). Galana-West consists of a N-S oriented wrench fault zone with vertical foliation planes and horizontal stretching lineation. Numerous shear sense indicators always show sinistral shear sense. Amphibolites of MORB affinity are involved in this wrench fault zone. To the west, this zone is bordered by calc-alkaline metatonalites of the Sagala Hills. The westernmost unit consists of the Taita Hills. They form an imbricated pile of southwestward thrusted nappe sheets containing metapelites, marbles, and ultramafics. The Taita Hills may be explained as part of an accretionary wedge. Southwestward nappe thrusting is also the prominent structure in the Pare and Usambara Mountains of Northern Tanzania. The following model may may explain these observations: The Southern Kenya -- Northern Tanzania section of the Mozambique Belt is the result of continental collision tectonics. Remnants of an island arc and of an accretionary wedge that occur at least in the Voi area may be part of a former subduction zone. An oceanic domain between an eastern passive continental margin and a western terrane, now represented by the Tanzanian granulite belt has been closed incorporating island arc and accretionary wedge material. Oblique convergence of two continental blocks is suggested from wrench tectonics. The age of convergent tectonics is 530 -- 580 Ma, dated by Sm-Nd garnet-whole rock analysis. This is interpreted as the age of peak metamorphism.

  9. Eocene-Oligocene sedimentation in the external areas of the Moldavide Basin (Marginal Folds Nappe, Eastern Carpathians, Romania): sedimentological, paleontological and petrographic approaches

    NASA Astrophysics Data System (ADS)

    Micl?u?, Crina; Loiacono, Francesco; Puglisi, Diego; Baciu, Dorin Sorin

    2009-10-01

    The Marginal Folds Nappe is one of the most external tectonic units of the Moldavide Nappe System (Eastern Carpathians), formed by Cretaceous to Tertiary flysch and molasse deposits, piled up during the Miocene closure of the East Carpathian Flysch basin, cropping out in several tectonic half-windows, the Bistri?a half-window being one of them. The deposits of this tectonic unit were accumulated in anoxic-oxic-anoxic conditions, in a forebulge depozone (sensu DeCelles & Giles 1996), and consist of a pelitic background sporadically interrupted by coarse-grained events. During the Late Eocene the sedimentation registered a transition from calcareous (Doamna Limestones) to pelitic (Bisericani Beds) grading to Globigerina Marls at the Eocene-Oligocene boundary, and upward during the Oligocene in deposits rich in organic matter (Lower Menilites, Bituminous Marls, Lower and Upper Dysodilic Shales) with coarsegrained interlayers. Seven facies associations were recognized, and interpreted as depositional systems of shallow to deeper water on a ramp-type margin. Two mixed depositional systems of turbidite-like facies association separated by a thick pelitic interval (Bituminous Marls) have been recognized. They were supplied by a "green schists" source area of Central Dobrogea type. The petrography of the sandstone beds shows an excellent compositional uniformity (quartzarenite-like rocks), probably representing a first cycle detritus derived from low rank metamorphic sources, connected with the forebulge relief developed on such a basement. The sedimentation was controlled mainly by different subsidence of blocks created by extensional tectonic affecting the ramp-type margin of the forebulge depozone.

  10. Spinel electrodes for rechargeable lithium batteries.

    SciTech Connect

    Thackeray, M. M.

    1999-11-10

    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).

  11. Rechargeable metal hydrides for spacecraft application

    NASA Technical Reports Server (NTRS)

    Perry, J. L.

    1988-01-01

    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.

  12. Advanced rechargeable sodium batteries with novel cathodes

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

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

  13. Advanced rechargeable sodium batteries with novel cathodes

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  14. High specific power lithium polymer rechargeable battery

    SciTech Connect

    Chu, M.Y.; De Jonghe, L.; Visco, S.

    1996-11-01

    PolyPlus Battery Company (PPBC) is developing an advanced lithium polymer rechargeable battery based on its proprietary positive electrode. This battery offers high steady-state (> 250 W/kg) and peak power densities (3,000 W/kg), in a low cost and environmentally benign format. This PolyPlus lithium polymer battery also delivers high specific energy. The first generation battery has an energy density of 100 Wh/kg (120 Wh/l) and subsequent generations increases the performance in excess of 500 Wh/kg (600 Wh/l). The high power and energy densities, along with the low toxicity and low cost of materials used in the PolyPlus solid-state cell makes this battery exceptionally attractive for both hybrid and electric vehicle applications.

  15. Polymer Energy Rechargeable System (PERS) Development Program

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  16. Nanostructured cathode materials for rechargeable lithium batteries

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

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

  17. Oxygen electrodes for rechargeable alkaline fuel cells

    NASA Technical Reports Server (NTRS)

    Swette, Larry; Giner, Jose

    1987-01-01

    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.

  18. Polymer Energy Rechargeable System Battery Being Developed

    NASA Technical Reports Server (NTRS)

    Manzo, Michelle A.

    2003-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  20. Simulation of the xerographic recharge process

    SciTech Connect

    Feng, Chang; Parker, S.E.; Lean, Meng H.

    1996-12-31

    Laser xerography (e.g. laser printing, photo-copying, etc.) involves the sequential steps: uniform charging of the photoconductor surface, discharging spots with a laser beam, developing the latent image on the photoconductor surface by the attachment of charged toner particles, and finally transfer-ring the image to paper through mechanical and electrostatic forces. Simulations have been developed that model these process from first-principles. Color reproduction involves multiple passes through these steps; once for each color separation (e.g. multiple toner layers on the photoconductor). Here we study the charging of the photoconductor surface, in situations of high mass-coverage with a 2D fluid model, and low mass coverage with a 3D particle model. Charge is sprayed using a corona, type discharge called a scorotron. We axe developing a 2D fluid model of the recharge process based on extending existing models. We use empirical IN data for the scorotron. A Boundary Integral Equation Method (BIEM) is used to solve for the field, and method of characteristics (MOC) to solve the charge continuity equation. Also developed, is a 3D particle model, where the field is solved using 3D BIEM and ionized air molecules axe treated as point charges which follow their average drift motion. Diffusion can be neglected because of the high voltage bias. Toner particles axe treated as finite size spherical dielectrics with nonuniform attached surface charge. We will show initial numerical results for both models. The purpose of this work is to develop a better understanding of how charge in transported through the toner layers in subsequent recharging during color laser xerography.

  1. Echo Meadows Project Winter Artificial Recharge.

    SciTech Connect

    Ziari, Fred

    2002-12-19

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

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

    SciTech Connect

    Hevesi, J.A.; Flint, A.L.

    1998-12-01

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

  3. Quantifying potential recharge in mantled sinkholes using ERT.

    PubMed

    Schwartz, Benjamin F; Schreiber, Madeline E

    2009-01-01

    Potential recharge through thick soils in mantled sinkholes was quantified using differential electrical resistivity tomography (ERT). Conversion of time series two-dimensional (2D) ERT profiles into 2D volumetric water content profiles using a numerically optimized form of Archie's law allowed us to monitor temporal changes in water content in soil profiles up to 9 m in depth. Combining Penman-Monteith daily potential evapotranspiration (PET) and daily precipitation data with potential recharge calculations for three sinkhole transects indicates that potential recharge occurred only during brief intervals over the study period and ranged from 19% to 31% of cumulative precipitation. Spatial analysis of ERT-derived water content showed that infiltration occurred both on sinkhole flanks and in sinkhole bottoms. Results also demonstrate that mantled sinkholes can act as regions of both rapid and slow recharge. Rapid recharge is likely the result of flow through macropores (such as root casts and thin gravel layers), while slow recharge is the result of unsaturated flow through fine-grained sediments. In addition to developing a new method for quantifying potential recharge at the field scale in unsaturated conditions, we show that mantled sinkholes are an important component of storage in a karst system. PMID:18823398

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

    NASA Astrophysics Data System (ADS)

    Williams, Alan E.

    1997-12-01

    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.

  5. [Effects of reclaimed water recharge on groundwater quality: a review].

    PubMed

    Chen, Wei-Ping; Lü, Si-Dan; Wang, Mei-E; Jiao, Wen-Tao

    2013-05-01

    Reclaimed water recharge to groundwater is an effective way to relieve water resource crisis. However, reclaimed water contains some pollutants such as nitrate, heavy metals, and new type contaminants, and thus, there exists definite environmental risk in the reclaimed water recharge to groundwater. To promote the development of reclaimed water recharge to groundwater and the safe use of reclaimed water in China, this paper analyzed the relevant literatures and practical experiences around the world, and summarized the effects of different reclaimed water recharge modes on the groundwater quality. Surface recharge makes the salt and nitrate contents in groundwater increased but the risk of heavy metals pollution be smaller, whereas well recharge can induce the arsenic release from sedimentary aquifers, which needs to be paid more attention to. New type contaminants are the hotspots in current researches, and their real risks are unknown. Pathogens have less pollution risks on groundwater, but some virus with strong activity can have the risks. Some suggestions were put forward to reduce the risks associated with the reclaimed water recharge to groundwater in China. PMID:24015541

  6. Effects of artificial recharge on the Ogallala aquifer, Texas

    USGS Publications Warehouse

    Brown, Richmond Flint; Keys, W.S.

    1985-01-01

    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.

  7. Recharge and discharge calculations to characterize the groundwater hydrologic balance

    SciTech Connect

    Liddle, R.G.

    1998-12-31

    Several methods are presented to quantify the ground water component of the hydrologic balance; including (1) hydrograph separation techniques, (2) water budget calculations, (3) spoil discharge techniques, and (4) underground mine inflow studies. Stream hydrograph analysis was used to calculate natural groundwater recharge and discharge rates. Yearly continuous discharge hydrographs were obtained for 16 watersheds in the Cumberland Plateau area of Tennessee. Baseflow was separated from storm runoff using computerized hydrograph analysis techniques developed by the USGS. The programs RECESS, RORA, and PART were used to develop master recession curves, calculate ground water recharge, and ground water discharge respectively. Station records ranged from 1 year of data to 60 years of data with areas of 0.67 to 402 square miles. Calculated recharge ranged from 7 to 28 inches of precipitation while ground water discharge ranged from 6 to 25 inches. Baseflow ranged from 36 to 69% of total flow. For sites with more than 4 years of data the median recharge was 20 inches/year and the 95% confidence interval for the median was 16.4 to 23.8 inches of recharge. Water budget calculations were also developed independently by a mining company in southern Tennessee. Results showed about 19 inches of recharge is available on a yearly basis. A third method used spoil water discharge measurements to calculate average recharge rate to the mine. Results showed 21.5 inches of recharge for this relatively flat area strip mine. In a further analysis it was shown that premining soil recharge rates of 19 inches consisted of about 17 inches of interflow and 2 inches of deep aquifer recharge while postmining recharge to the spoils had almost no interflow component. OSM also evaluated underground mine inflow data from northeast Tennessee and southeast Kentucky. This empirical data showed from 0.38 to 1.26 gallons per minute discharge per unit acreage of underground workings. This is the equivalent to 7 to 24 inches of recharge per year. The four methods provide a good comparative way to quantify the groundwater portion of the hydrologic balance.

  8. Sedimentary Origins Of The Block-In-Matrix Fabric Of A Mélange Between Coherent Nappes Of A Subduction Complex: Localization Of The Paleosubduction Megathrust Along The Upper Mélange Contact

    NASA Astrophysics Data System (ADS)

    Wakabayashi, J.

    2011-12-01

    The Franciscan subduction complex of California comprises coherent nappes and intervening mélanges. The difference in metamorphic grade and/or accretionary age of adjacent coherent nappes suggests localization of paleosubduction megathrust horizons between them. One of the best examples of a mélange between coherent nappes crops out in an inactive quarry in El Cerrito in the eastern San Francisco Bay area. The upper coherent nappe consists of foliated, jadeite-bearing, blueschist facies metagraywacke, whereas the lower coherent nappe comprises prehnite-pumpellyite facies graywacke with little or no penetrative fabric makes. Detrital zircon geochronology indicates maximum depositional ages of 102 and 100 Ma, respectively, for these units. The foliation or bedding of the graywackes and their contacts strike northwest and dip northeast. C-s fabrics, shear bands, and asymmetric porphyroclasts show a consistent tops-to-the-southwest shear sense in the upper coherent unit, and this fabric developed with syntectonic growth of glaucophane, lawsonite, and jadeite. The intervening mélange has a matrix made up primarily of dark gray shale, with blocks of mostly graywacke, chert, and basalt. The mélange consists of mostly or entirely prehnite-pumpellyite facies material except for the upper 5-10 meters that features metamorphic growth of lawsonite, glaucophane, and jadeite. Thus, the metamorphic contrast between the two nappes, equivalent to at least 10 km in differential burial depth and greater amount of fault displacement, occurs within this narrow zone. The upper half of the mélange (~50 meters of structural thickness) exhibits a pronounced foliation oriented parallel to the bounding contacts. The foliation deflects into shear bands and c-surfaces and this fabric shows a consistent tops-to-the-southwest shear sense. Strain appears to increase structurally upward within the mélange. The structurally lowest part of the mélange displays virtually no strain, with minimal, if any, foliation development. Here the matrix consists of shale or sandstone matrix breccia and conglomerate with the same population of exotic clasts/blocks seen in the more deformed upper parts of the mélange; these clasts also include a pyroxenite block. These relationships indicate an olistostromal origin for the block-in-matrix fabric with subsequent accommodation of large-scale thrust displacement (the paleosubduction megathrust) along the upper contact of the mélange.

  9. Amputation des quatre membres

    PubMed Central

    Feruzi, Maruis Kitembo; Milindi, Cédrick Sangwa; Zabibu, Mireille Kakinga; Mulefu, Jules Panda; Katombe, Francois Tshilombo

    2014-01-01

    Les auteurs présentent les cas d'amputation des quatre membres réalisée chez trois patients différents. Ce sont des amputations réalisées pour chaque patient au cours d'une seule hospitalisation et en un seul temps opératoire. Deux patients pour gangrène sèche infectée et un pour amputation traumatique des quatre membres. L'amputation d'urgence a été pratiquée en premier temps suivie de remodelage des moignons d'amputation en second temps. L’évolution de tous les patients a été bonne. PMID:25469177

  10. Bipolar rechargeable lithium battery for high power applications

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    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.

  11. NTS groundwater recharge study, FY 1992. Data report

    SciTech Connect

    Lyles, B F; Mihevc, T M

    1992-10-01

    Groundwater recharge from precipitation is thought by many scientists to be extremely low in Southem Nevada; however, no direct measurements of recharge have been made to substantiate this hypothesis. Three geomorphic regions have been identified as potential areas of groundwater recharge at the Nevada Test Site (NTS): mesas, washes, and lowlands. Eight recharge monitoring stations have been installed to monitor each of these regions; four of the stations are on Pahute/Rainier Mesa, two stations are in Fortymile Wash, one station is in a transition area between the mesas and the lowlands (Whiterock Spring), and one station is located in Yucca Flat at the bottom of the U-3fd crater. An additional station is proposed for Frenchman Flat near the Area 5 mixed waste facility; however, the instrumentation of that site has been delayed due to the complex permitting process associated with instrument installation near the mixed waste facility. Digital data were collected from eight sites during FY 1992.

  12. Reliability of Rechargeable Batteries in a Photovoltaic Power Supply System

    SciTech Connect

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

    1998-11-30

    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.

  13. Improved zinc electrode and rechargeable zinc-air battery

    DOEpatents

    Ross, P.N. Jr.

    1988-06-21

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

  14. 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 ...

  15. Implantable wireless battery recharging system for bladder pressure chronic monitoring.

    PubMed

    Young, Darrin J; Cong, Peng; Suster, Michael A; Damaser, Margot

    2015-11-21

    This paper presents an implantable wireless battery recharging system design for bladder pressure chronic monitoring. The wireless recharging system consists of an external 15 cm-diameter 6-turn powering coil and a silicone-encapsulated implantable rectangular coil with a dimension of 7 mm × 17 mm × 2.5 mm and 18 turns, which further encloses a 3 mm-diameter and 12 mm-long rechargeable battery, two ferrite rods, an ASIC, and a tuning capacitor. For a constant recharging current of 100 ?A, an RF power of 700 ?W needs to be coupled into the implantable module through the tuned coils. Analyses and experiments confirm that with the two coils aligned coaxially or with a 6 cm axial offset and a tilting angle of 30°, an external power of 3.5 W or 10 W is required, respectively, at an optimal frequency of 3 MHz to cover a large implant depth of 20 cm. PMID:26419677

  16. ENGINEERING ECONOMIC ANALYSIS OF A PROGRAM FOR ARTIFICIAL GROUNDWATER RECHARGE.

    USGS Publications Warehouse

    Reichard, Eric G.; Bredehoeft, John D.

    1984-01-01

    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.

  17. Ajustement du rechargement et des mecanismes de reactivite des reacteurs CANDU pour les cycles de combustible avances

    NASA Astrophysics Data System (ADS)

    St-Aubin, Emmanuel

    This research project main objectives are to set up and apply a methodology that can determine the potential of advanced thorium-based fuel cycles in CANDU reactors and that is able to adjust reactivity devices, in such a way as to maintain their reference efficiency for these new fuels. In order to select these fuel cycles, a large alternative fuel envelope is submitted to several discriminating criteria. A coarse parametric core modeling, that takes into account standard reactivity devices, is first used to highlight candidates presenting the best economical performances and to eliminate non viable options. Then, for the best candidates, the neutronic modeling is optimized before considering reactivity devices adjustment. For every reactivity device managed by the reactor regulating system, innovative generic optimization methods are used to achieve specific objectives for every fuel cycle, all of them being based on the reference natural uranium cycle behavior. Specific optimization objectives are assessed by simulating advanced fuel cycle for specific operating conditions, including : normal on-power refueling period, spurious reactor trip and fueling machine unavailibility. Unlike the generalized perturbative approach proposed in the OPTEX code, we have successfully implemented a multi-step method able to maximize both the energy extracted from the fuel using an equilibrium refueling optimization, and the reactivity devices adequacy. We also propose new reactivity device supercell models that provides accurate reactor databases for a fraction of the computing cost usually needed using a full model with a similar spatial discretization. Our approach is verified by comparing our simulation results with results published in the literature for the reference fuel cycle. The methodology developed identified advanced fuel cycles, containing up to 60%v. thorium, thereby increasing resources utilization by more than 50% and multiplying the fuel average exit burn-up by a factor of 4.4 when compared with the reference cycle. The reactivity devices were also retained after our optimization processes, requiring only minor modifications to the original design. We determined that a 10%v. heavy water doping of the light water within liquid zone controllers could increase the average exit burnup of the reference cycle by almost 1%, without any adverse consequence to the reactor control. This method is validated through its systematic application to numerous different cases. It demonstrates its capability to achieve very different objectives related to reactivity devices requirements, thus it can be now used for other similar studies.

  18. Hydrogeological Methods for Assessing Feasibility of Artificial Recharge

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Koo, M.; Lee, K.; Moon, D.; Barry, J. M.

    2009-12-01

    This study presents the hydrogeological methods to assess the feasibility of artificial recharge in Jeju Island, Korea for securing both sustainable groundwater resources and severe floods. Jeju-friendly Aquifer Recharge Technology (J-ART) in this study is developing by capturing ephemeral stream water with no interference in the environments such as natural recharge or eco-system, storing the flood water in the reservoirs, recharging it through designed borehole after appropriate water treatment, and then making it to be used at down-gradient production wells. Many hydrogeological methods, including physico-chemical surface water and groundwater monitoring, geophysical survey, stable isotope analysis, and groundwater modeling have been employed to predict and assess the artificially recharged surface waters flow and circulation between recharge area and discharge area. In the study of physico-chemical water monitoring survey, the analyses of surface water level and velocity, of water qualities including turbidity, and of suspended soil settling velocity were performed. For understanding subsurface hydrogeologic characteristics the injection test was executed and the results are 118-336 m2/day of transmissivity and 4,367-11,032 m3/day of the maximum intake water capacity. Characterizing groundwater flow from recharge area to discharge area should be achieved to assess the efficiency of J-ART. The resistivity logging was carried out to predict water flow in unsaturated zone during artificial recharge based on the inverse modeling and resistivity change patterns. Stable isotopes of deuterium and oxygen-18 of surface waters and groundwaters have been determined to interpret mixing and flow in groundwaters impacted by artificial recharge. A numerical model simulating groundwater flow and heat transport to assess feasibility of artificial recharge has been developed using the hydraulic properties of aquifers, groundwater levels, borehole temperatures, and meteorological data. Also, groundwater modeling was performed to aid in artificial recharge system design, such as optimizing number and spacing of injection wells, building up and maintaining a water column inside each operating injection well, and optimizing time. Acknowledgements This research was supported by a grant (code 3-2-3) from the Sustainable Water Resources Research Center of 21st Century Frontier Research Program and the Basic Research Program (09-3414) of KIGAM.

  19. Cryogenic Transport of High-Pressure-System Recharge Gas

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

    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.

  20. Ground water recharge and flow characterization using multiple isotopes.

    PubMed

    Chowdhury, Ali H; Uliana, Matthew; Wade, Shirley

    2008-01-01

    Stable isotopes of delta(18)O, delta(2)H, and (13)C, radiogenic isotopes of (14)C and (3)H, and ground water chemical compositions were used to distinguish ground water, recharge areas, and possible recharge processes in an arid zone, fault-bounded alluvial aquifer. Recharge mainly occurs through exposed stream channel beds as opposed to subsurface inflow along mountain fronts. This recharge distribution pattern may also occur in other fault-bounded aquifers, with important implications for conceptualization of ground water flow systems, development of ground water models, and ground water resource management. Ground water along the mountain front near the basin margins contains low delta(18)O, (14)C (percent modern carbon [pmC]), and (3)H (tritium units [TU]), suggesting older recharge. In addition, water levels lie at greater depths, and basin-bounding faults that locally act as a flow barrier may further reduce subsurface inflow into the aquifer along the mountain front. Chemical differences in ground water composition, attributed to varying aquifer mineralogy and recharge processes, further discriminate the basin-margin and the basin-center water. Direct recharge through the indurated sandstones and mudstones in the basin center is minimal. Modern recharge in the aquifer is mainly through the broad, exposed stream channel beds containing coarse sand and gravel where ground water contains higher delta(18)O, (14)C (pmC), and (3)H (TU). Spatial differences in delta(18)O, (14)C (pmC), and (3)H (TU) and occurrences of extensive mudstones in the basin center suggest sluggish ground water movement, including local compartmentalization of the flow system. PMID:18384592

  1. Statistical Method for Identification of Potential Groundwater Recharge Zone

    NASA Astrophysics Data System (ADS)

    Banerjee, Pallavi; Singh, V. S.

    2010-05-01

    The effective development of groundwater resource is essential for a country like India. Artificial recharge is the planned, human activity of augmenting the amount of groundwater available through works designed to increase the natural replenishment or percolation of surface waters into the groundwater aquifers, resulting in a corresponding increase in the amount of groundwater available for abstraction. India receives good amount of average annual rainfall about 114 cm but most of it's part waste through runoff. The imbalance between rainfall and recharge has caused serious shortage of water for drinking, agriculture and industrial purposes. The over exploitation of groundwater due to increasing population is an additional cause of water crisis that resulting in reduction in per capita availability of water in the country. Thus the planning for effective development of groundwater is essential through artificial recharge. Objective of the paper is to identification of artificial recharge zones by arresting runoff through suitable sites to restore groundwater conditions using statistical technique. The water table variation follows a pattern similar to rainfall variation with time delay. The rainfall and its relationship with recharge is a very important process in a shallow aquifer system. Understanding of this process is of critical importance to management of groundwater resource in any terrain. Groundwater system in a top weathered regolith in a balastic terrain forms shallow aquifer is often classified into shallow water table category. In the present study an effort has been made to understand the suitable recharge zone with relation to rainfall and water level by using statistical analysis. Daily time series data of rainfall and borehole water level data are cross correlated to investigate variations in groundwater level response time during the months of monsoon. This measurement facilitate to demarcate favorable areas for Artificial Recharge. KEYWORDS: Water level; Rainfall; Recharge; Statistical analysis; Cross correlation.

  2. Rechargeable wireless EMG sensor for prosthetic control.

    PubMed

    Lichter, P A; Lange, E H; Riehle, T H; Anderson, S M; Hedin, D S

    2010-01-01

    Surface electrodes in modern myoelectric prosthetics are often embedded in the prosthesis socket and make contact with the skin. These electrodes detect and amplify muscle action potentials from voluntary contractions of the muscle in the residual limb and are used to control the prosthetic's movement and function. There are a number of performance-related deficiencies associated with external electrodes including the maintenance of sufficient electromyogram (EMG) signal amplitude, extraneous noise acquisition, and proper electrode interface maintenance that are expected to be improved or eliminated using the proposed implanted sensors. This research seeks to investigate the design components for replacing external electrodes with fully-implantable myoelectric sensors that include a wireless interface to the prosthetic limbs. This implanted technology will allow prosthetic limb manufacturers to provide products with increased performance, capability, and patient-comfort. The EMG signals from the intramuscular recording electrode are amplified and wirelessly transmitted to a receiver in the prosthetic limb. Power to the implant is maintained using a rechargeable battery and an inductive energy transfer link from the prosthetic. A full experimental system was developed to demonstrate that a wireless biopotential sensor can be designed that meets the requirements of size, power, and performance for implantation. PMID:21095801

  3. Wearable textile battery rechargeable by solar energy.

    PubMed

    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

    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

  4. Transient Rechargeable Batteries Triggered by Cascade Reactions.

    PubMed

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

    2015-07-01

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

  5. Thin-film Rechargeable Lithium Batteries

    DOE R&D Accomplishments Database

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

    1993-11-01

    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.

  6. Advanced rechargeable sodium batteries with novel cathodes

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    Various high energy density rechargeable batteries are being considered for future space applications. Of these, the sodium-sulfur battery is one of the leading candidates. The primary advantage is the high energy density (760 Wh/kg theoretical). Energy densities in excess of 180 Wh/kg 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.

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

    SciTech Connect

    2010-10-01

    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.

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

    SciTech Connect

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

    2010-10-27

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

  9. Seasonal variation in natural recharge of coastal aquifers

    NASA Astrophysics Data System (ADS)

    Mollema, Pauline N.; Antonellini, Marco

    2013-06-01

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

  10. Estimating aquifer channel recharge using optical data interpretation.

    PubMed

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

    2012-01-01

    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

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

    NASA Astrophysics Data System (ADS)

    Balleau, W. Peter

    2013-01-01

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

  12. Remnants of a hyperextended passive margin in a Caledonian mélange unit below the Jotun nappe, B\\overdalen, Central-south Norway

    NASA Astrophysics Data System (ADS)

    Alsaif, Manar; Jakob, Johannes; Andersen, Torgeir; Corfu, Fernando

    2015-04-01

    The Scandinavian Caledonides have been long studied, yet their ever unfolding complexity renders them far from being fully understood. It has been recognized that the Caledonian Allochthons have neither a linear nor straightforward along-strike relationship (Corfu et al. 2014). A mélange unit has been recently identified as a separate tectonic unit (Andersen et al. 2012). This unit is structurally positioned below crystalline nappes previously assigned to the Middle Allochthon. The mélange comprises meta-sediments and minor meta-basalt/gabbro, but most intriguingly, numerous solitary meta-peridotites. These occur as 'Alpine type' meta-peridotites, serpentinites, soapstones and detrital serpentinites. We present results of a field study of the mélange in the B\\overdalen area, structurally below the Jotun nappe, and suggest that this provides further evidence that the regional mélange unit was formed in a hyperextended passive margin. The meta-peridotites represent exhumed serpentinized mantle and are intimately associated with meta-sediments. The sediments are garnetiferous chlorite-muscovite schists, graphitic schists, phyllites, amphibolites, meta-sandstones as well as quartzite-pebble dominated conglomerates. It is suggested that this highly heterogeneous unit formed during the early stages of rifting and hyperextension along the Baltican passive margin. Characteristics of the detrital peridotites suggests that serpentinite-talc protrusions may have formed islands. The processes involved are observed on modern margins where the best-studied example is the Iberia-Newfoundland passive margin. Work in present-day margins (mostly seismic reflection data) elucidate the large-scale structure of hyperextended margins, while studies of ancient exposed examples in mountain belts provide insight into the lithology, geochemistry and details of these margins. The widespread distribution of hyperextended margins in modern margins and the increasing number of recognizable ancient margins in mountain-belts indicates the importance of hyperextension during the early stages of the Wilson cycle. Tectonic reconstructions that account for such complexity may not only explain the origin of peridotite bearing mélange units, they may also aid the understanding of the exotic terranes identified in the Scandinavian Caledonides. Andersen T.B., Corfu F., Labrousse L. and Osmundsen P.T. 2012 Evidence for hyperextension along the pre-Caledonian margin of Baltica. Journal of the Geological Society, London 169: 601-612 Corfu, F., Andersen, T.B. and Gasser, D. The Scandinvian Caledonides: main features, conceptual advances and critical questions. Geological Society of London Special Publications, 390 (2014) doi:10.1144/SP390.25

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

    USGS Publications Warehouse

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

    2007-01-01

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

  14. Coupling Stormwater Capture and Managed Aquifer Recharge

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  15. Oxygen electrodes for rechargeable alkaline fuel cells

    NASA Technical Reports Server (NTRS)

    Swette, L.; Kackley, N.

    1989-01-01

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

  16. Arsenic release during managed aquifer recharge (MAR)

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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.

  17. Design and simulation of lithium rechargeable batteries

    SciTech Connect

    Doyle, C.M.

    1995-08-01

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

  18. A new model for the formation of a spaced crenulation (shear band) cleavage in the Dalradian rocks of the Tay Nappe, SW Highlands, Scotland

    NASA Astrophysics Data System (ADS)

    Geoff Tanner, P. W.

    2016-03-01

    The main conclusion of this study is that non-coaxial strain acting parallel to a flat-lying D1 spaced cleavage was responsible for the formation of the D2 spaced crenulation (shear band) cleavage in Dalradian rocks of Neoproterozoic-Lower Ordovician age in the SW Highlands, Scotland. The cm-dm-scale D2 microlithons are asymmetric; have a geometrically distinctive nose and tail; and show a thickened central portion resulting from back-rotation of the constituent D1 microlithons. The current terminology used to describe crenulation cleavages is reviewed and updated. Aided by exceptional 3D exposures, it is shown how embryonic D2 flexural-slip folds developed into a spaced cleavage comprising fold-pair domains wrapped by anastomosing cleavage seams. The bulk strain was partitioned into low-strain domains separated by zones of high non-coaxial strain. This new model provides a template for determining the sense of shear in both low-strain situations and in ductile, higher strain zones where other indicators, such as shear folds, give ambiguous results. Analogous structures include tectonic lozenges in shear zones, and flexural-slip duplexes. Disputes over the sense and direction of shear during emplacement of the Tay Nappe, and the apparently intractable conflict between minor fold asymmetry and shear sense, appear to be resolved.

  19. Thermal Methods for Investigating Ground-Water Recharge

    USGS Publications Warehouse

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

    2007-01-01

    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.

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

    PubMed

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

    2015-07-01

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

  1. Fate of human viruses in groundwater recharge systems

    SciTech Connect

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

    1980-03-01

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

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

    USGS Publications Warehouse

    Brown, Richmond F.; Signor, Donald C.

    1973-01-01

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

  3. Note des Éditeurs scientifiques

    NASA Astrophysics Data System (ADS)

    Averbuch, P.

    Cette série d'articles est une revue de résultats expérimentaux sur différents "fluides" moléculaires, dans lesquels la cohésion est due à des forces de Van der Waals et à des liaisons hydrogène, l'eau étant un de ces fluides. Ces résultats sont présentés de façon à justifier expérimentalement un modèle original, non extensif, des propriétés de ces fluides, et l'ensemble se présente sous la forme de trois articles décrivant le modèle, suivis chacun par un article le comparant aux résultats expérimentaux publiés par de nombreux auteurs. Le caractère non extensif des propriétés physiques des fluides est choquant, contraire à beaucoup d'idées établies, il semble n'avoir en sa faveur qu'un argument, la comparaison avec un nombre de résultats expérimentaux assez grand pour que l'effet du hasard soit difficilement soupçonnable. En particulier, les écarts entre des résultats de mesures faits par des auteurs différents dans des conditions différentes sont expliqués, le sérieux et la compétence des différents expérimentateurs ne sont plus mis en doute : mais l'interprétation de ces résultats avec un modèle extensif non adapté est seule mise en cause. Les modèles extensifs étant utilisés systématiquement, au delà des expériences de physiciens, dans les calculs d'ingénieurs, et dans la modélisation d'appareils qui fonctionnent et de phénomènes naturels observés par tout le monde, il fallait expliquer pourquoi on pouvait renoncer à l'extensivité. Les raisons du succès pratique des modèles extensifs sont données, d'abord dans le cas des nématiques, puis dans celui des liquides ordinaires, et c'est ce qui rend l'ensemble cohérent, tant avec les mesures physiques fines qu'avec les observations quotidiennes. Il n'en reste pas moins que si l'interprétation donnée dans cette série d'articles est généralisable, une justification théorique du modèle utilisé devient nécessaire. Pour ce qui est des propriétés d'équilibre, une séparation de l'énergie libre en énergie libre de volume et en énergie libre de surface devrait donner les mêmes résultats ; par contre les choses deviennent troublantes dès que l'on passe aux coefficients de transport, c'est-à-dire à l'aspect macroscopique de la dynamique moléculaire. Il y a là un écart notable avec les conceptions courantes, ce qui rend très surprenante la lecture de ces articles. On peut mentionner la liste des problèmes théoriques posés par la description phénoménologique qui est celle de cette série d'articles : la généralisation de lois d'échelle en dehors de zones critiques n'est pas absolument nouvelle, par contre la simplicité des lois reliant l'exposant v à la température pose problème ; le sens des temps de relaxation utilisés est sans doute également à préciser. Enfin les modes considérés semblent n'intervenir dans les propriétés thermodynamiques que par un facteur par mode, comme si seulement l'énergie potentielle devait intervenir, les termes cinétiques ne participant pas vraiment aux transitions de phase. Tout cela pose donc problème, et l'on peut se demander si un pareil modèle peut être compatible avec tout ce qui est connu par ailleurs en physique statistique. Mais s'il rend bien compte de beaucoup de résultats expérimentaux, ce sont ces derniers qui seraient en difficulté avec la mécanique statistique. Il a donc semblé préférable de publier le modèle, sa justification expérimentale et de poser quelques problèmes, tant aux théoriciens, qui pourraient expliquer pourquoi un tel modèle rend compte de résultats observés, qu'aux expérimentateurs, qui pourraient reprendre certaines mesures, et délimiter le caractère plus ou moins général du modèle.

  4. Heat transport in the vicinity of an artificial recharge site

    NASA Astrophysics Data System (ADS)

    Vandenbohede, Alexander; van Houtte, Emmanuel; Lebbe, Luc

    2010-05-01

    Since July 2002, the Intermunicipal Water Company of the Veurne region (IWVA) artificially recharges fresh water in the dunes of the western Belgian coastal plain by means of two recharge ponds. This recharge water is produced from secondary treated waste water effluent by the combination of ultra filtration and reverse osmosis. Extraction wells (112) are located north and south of the ponds. The artificial recharge project loops the water cycle: extracted water goes to the users and their waste water is purified and re-used. Therefore, it is an example of sustainable water management in coastal aquifers. Groundwater flow of this recharge site has been examined in the past by the use of a tracer test, hydrochemistry (environmental isotopes, conservative tracers) and groundwater flow modelling. Temperature, however, forms a relatively easy measurement which can add to or confirm the knowledge of the groundwater flow. Temperature time series (temperature as function of time) were measured at different levels in a number of wells located between the recharge ponds and the extraction wells, and in one well south of the recharge and extraction area. Secondly, temperature logs (temperature as function of depth) were measured in these wells at different times over the course of 2 years. Finally, the temperature of the recharged and extracted water is constantly monitored by the water company. The temperature of the recharge water shows a yearly fluctuation, ranging from 25 °C during summer to slightly above 0 °C during the winter. The temperature of the extracted water (combination of water extracted in all the wells) ranges between 17 °C during summer and 10 °C during winter. Minima and maxima in the extracted water are observed between 76 and 110 days (mean of 90 days and standard deviation of 13.5 days) later in the extracted water with respect to the recharged water. Measurements show that the difference in time when maxima and minima are observed in an observation well with reference to the ponds increases with depth (for instance from 28 days 4.1 m below surface to 154 days 10 m below surface for an observation well at 10 m from the ponds). This confirms previous flow modelling which showed that groundwater flows relatively rapidly laterally from the recharge ponds towards the extraction wells. Additionally, part of the recharge water flows in a deeper flow cycle towards the extraction wells. Residence times in this deeper flow cycle are evidently larger than in the direct lateral flow cycle from the ponds towards the wells. This explains the increase with depth. The 154 days (with respect to a mean time of 90 days) points to the fact that the extracted water contains a large spectrum of residence times with mean of 90 days for the heat transport, as was also derived by the flow modelling previously

  5. Sulfone-based electrolytes for aluminium rechargeable batteries.

    PubMed

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

    2015-02-28

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

  6. Hydrogeology of Regional Valley Fill Aquifers with Mountain System Recharge

    NASA Astrophysics Data System (ADS)

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

    2009-05-01

    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.

  7. 76 FR 70531 - Fifth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems-Small...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-14

    ... Federal Aviation Administration Fifth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery.... Department of Transportation (DOT). ACTION: Notice of RTCA Special Committee 225, Rechargeable Lithium... public of a meeting of RTCA Special Committee 225, Rechargeable Lithium Battery and Battery...

  8. Diethylstilbestrol (DES) and Cancer

    MedlinePLUS

    ... Other Funding Find NCI funding for small business innovation, technology transfer, and contracts Training Cancer Training at ... following: Pelvic examination Pap test and colposcopy —A routine cervical Pap test is not adequate for DES ...

  9. Thin Rechargeable Batteries for CMOS SRAM Memory Protection

    NASA Technical Reports Server (NTRS)

    Crouse, Dennis N.

    1993-01-01

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

  10. Modelling of recharge and pollutant fluxes to urban groundwaters.

    PubMed

    Thomas, Abraham; Tellam, John

    2006-05-01

    Urban groundwater resources are of considerable importance to the long-term viability of many cities world-wide, yet prediction of the quantity and quality of recharge is only rarely attempted at anything other than a very basic level. This paper describes the development of UGIf, a simple model written within a GIS, designed to provide estimates of spatially distributed recharge and recharge water quality in unconfined but covered aquifers. The following processes (with their calculation method indicated) are included: runoff and interception (curve number method); evapotranspiration (Penman-Grindley); interflow (empirical index approach); volatilization (Henry's law); sorption (distribution coefficient); and degradation (first order decay). The input data required are: meteorological data, landuse/cover map with event mean concentration attributes, geological maps with hydraulic and geochemical attributes, and topographic and water table elevation data in grid form. Standard outputs include distributions of: surface runoff, infiltration, potential recharge, ground level slope, interflow, actual recharge, pollutant fluxes in surface runoff, travel times of each pollutant through the unsaturated zone, and the pollutant fluxes and concentrations at the water table. The process of validation has commenced with a study of the Triassic Sandstone aquifer underlying Birmingham, UK. UGIf predicts a similar average recharge rate for the aquifer as previous groundwater flow modelling studies, but with significantly more spatial detail: in particular the results indicate that recharge through paved areas may be more important than previously thought. The results also highlight the need for more knowledge/data on the following: runoff estimation; interflow (including the effects of lateral flow and channelling on flow times and therefore chemistry); evapotranspiration in paved areas; the nature of unsaturated zone flow below paved areas; and the role of the pipe network. Although considerably more verification is needed, UGIf shows promise for use: in providing input for regional groundwater solute transport models; in identifying gaps in knowledge and data; in determining which processes are the most important influences on urban groundwater quantity and quality; in evaluating existing recharge models; in planning, for example in investigation of the effects of landuse or climate change; and in assessing groundwater vulnerability. PMID:16325236

  11. Focused Ground-Water Recharge in the Amargosa Desert Basin

    USGS Publications Warehouse

    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

    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.

  12. Possible silica gel in the Olive Fault, Naukluft Nappe Complex, Namibia: A geologic record of dynamic weakening in faults during continental orogenesis

    NASA Astrophysics Data System (ADS)

    Faber, C.; Rowe, C. D.; Miller, J. A.; Backeberg, N.; Sylvester, F.

    2009-12-01

    The apparently low frictional strength of faults during earthquake slip is not sufficiently well explained. Dynamic weakening has been observed in recent laboratory experiments at seismic slip rates, even if materials are strong at slow slip rates. Di Toro et al. (2004) performed experiments on crystalline rocks at slip rates of 1m/s and observed frictional strength drops to near zero. Examination of the slip surface revealed an amorophous silica had formed during fast slip and interpreted this as a solidified silica gel. If similar silica gel forms during earthquakes, and solidifies to amorphous silica, it would be expected to slowly crystallize over time. Ujiie et al (2007) reported a microcrystalline silica fault vein from the Shimanto Complex (Japan) which contains colloidal microspheres of silica, consistent with its origin as a silica gel. This vein may have been created during seismic slip, although other explanations are possible. No other natural examples of this potentially important coseismic weakening mechanism have been reported. To investigate whether silica gel actually forms during seismic slip, it will be necessary to discover and fully characterize additional natural examples. The Naukluft Nappe Complex in central Namibia is a foreland thrust stack at the distal southern margin of the Pan-African Damara Orogen (active at ~ 550Ma). A fault vein of microcrystalline silica has been found in an intra-nappe thrust fault . The vein occurs as a mostly continuous, planar, 0.1-1.0cm-thick fault vein within dolomite breccias of the Olive Fault. There are no other veins of silica associated with the fault. The hanging wall and footwall are dolomite and calcareous shales, respectively. The layer is petrographically similar to the microcrystalline silica described by Ujiie et al. (2007). The silica layer is purple-blue to white in color cathodoluminescence, in contrast to the bright turquoise typical of quartz. Although X-ray diffraction spectra show only silica and minor dolomite in the fault vein, SEM revealed the presence of small grains of Ti-oxides which have not been observed in the host rock. The cathodoluminescence has also revealed primary textures in the dolomite breccias which are overprinted by recrystallization and invisible in transmitted light . Transmission Electron Microscopy will be used to determine whether colloidal silica particles are present. The possible finding of the solidified silica gel in the Olive Fault is significant because it may represent a new way to identify fault surfaces which have slipped seismically in the past. In particular, the presence of this unusual silica vein in a carbonate-dominated environment is consistent with the experiments of Di Toro et al (2004) who suggested that quartz need not be present in the source rocks in order to form silica gel. Di Toro, G. et al. (2004) Friction falls towards zero in quartz rock as slip velocity approaches seismic rates. Nature, 427, 436-439 Ujie, K. et al. (2007) Fluidization of granular material in a subduction thrust at seismogenic depths. EPSL, 259, 307-318

  13. Seismic source study of the Racha-Dzhava (Georgia) earthquake from aftershocks and broad-band teleseismic body-wave records: An example of active nappe tectonics

    USGS Publications Warehouse

    Fuenzalida, H.; Rivera, L.; Haessler, H.; Legrand, D.; Philip, H.; Dorbath, L.; McCormack, D.; Arefiev, S.; Langer, C.; Cisternas, A.

    1997-01-01

    The Racha-Dzhava earthquake (Ms = 7.0) that occurred on 1991 April 29 at 09:12:48.1 GMT in the southern border of the Great Caucasus is the biggest event ever recorded in the region, stronger than the Spitak earthquake (Ms = 6.9) of 1988. A field expedition to the epicentral area was organised and a temporary seismic network of 37 stations was deployed to record the aftershock activity. A very precise image of the aftershock distribution is obtained, showing an elongated cloud oriented N105??, with one branch trending N310?? in the western part. The southernmost part extends over 80 km, with the depth ranging from 0 to 15 km, and dips north. The northern branch, which is about 30 km long, shows activity that ranges in depth from 5 to 15 km. The complex thrust dips northwards. A stress-tensor inversion from P-wave first-motion polarities shows a state of triaxial compression, with the major principal axis oriented roughly N-S, the minor principal axis being vertical. Body-waveform inversion of teleseismic seismograms was performed for the main shock, which can be divided into four subevents with a total rupture-time duration of 22 s. The most important part of the seismic moment was released by a gentle northerly dipping thrust. The model is consistent with the compressive tectonics of the region and is in agreement with the aftershock distribution and the stress tensor deduced from the aftershocks. The focal mechanisms of the three largest aftershocks were also inverted from body-wave records. The April 29th (Ms = 6.1) and May 5th (Ms = 5.4) aftershocks have thrust mechanisms on roughly E-W-oriented planes, similar to the main shock. Surprisingly, the June 15th (Ms = 6.2) aftershock shows a thrust fault striking N-S. This mechanism is explained by the structural control of the rupture along the east-dipping geometry of the Dzirula Massif close to the Borzhomi-Kazbeg strike-slip fault. In fact, the orientation and shape of the stress tensor produce a thrust on a N-S oriented plane. Nappe tectonics has been identified as an important feature in the Caucasus, and the source mechanism is consistent with this observation. A hidden fault is present below the nappe, and no large surface breaks were observed due to the main shock. The epicentral region is characterized by sediments that are trapped between two crystalline basements: the Dzirula Massif, which crops out south of Chiatoura, and the Caucasus Main Range north of Oni. Most, if not all, of the rupture is controlled by the thrusting of overlapping, deformed and folded sediments over the Dzirula Massif. This event is another example of blind active faults, with the distinctive feature that the fault plane dips at a gentle angle. The Racha Range is one of the surface expressions of this blind thrust, and its growth is the consequence and evidence of similar earthquakes in the past.

  14. The UHP metamorphic Seve Nappe Complex of the Swedish Caledonides - a new occurrence of the microdiamond-bearing gneisses and their exhumation

    NASA Astrophysics Data System (ADS)

    Klonowska, Iwona; Janák, Marian; Majka, Jaros?aw; ? Froitzheim, Nikolaus; Gee, David G.

    2015-04-01

    The ultra-high pressure metamorphism (UHPM) in the Seve Nappe Complex of the Swedish Caledonides has been recently recognized within several lithologies including gneisses, eclogites and garnet pyroxenites (e.g. Janák et al. 2013, Klonowska et al. 2014a, Majka et al. 2014). Thermodynamic modelling and thermobarometric calculations indicate peak pressure conditions of >3GPa at c. 800-900°C (reaching the diamond stability field) for eclogites and garnet pyroxenites from northern Jämtland (e.g. Klonowska et al. 2014b). In addition to this, the first microdiamonds were found in paragneisses from the Snasahögarna Mt. in central Jämtland (Majka et al. 2014). Here we report a new discovery of microdiamond together with moissanite (SiC) from one of the world's most famous localities for thrusting, Mount Åreskutan, where long transport distances were recognized already in the 19th century (Törnebohm 1888). Garnet porphyroblasts in gneisses from the Åreskutan Mt. contain abundant mineral inclusions, mainly graphite, carbonates and quartz, together with fluid inclusions of CO2 concentrated in swarms. Among these inclusions three microdiamonds were found in two gneiss samples. In one of the samples moissanite was also discovered. Both minerals were identified by micro-Raman spectroscopy. In addition to these 'swarm' inclusions, biotite, kyanite, rutile, feldspars, zircon, monazite, ±phengite, ±muscovite, ±spinel, ±ilmenite, ±apatite occur in garnets. Phase equilibrium modelling for the phengite-bearing gneiss confirms its UHP history at temperatures of c. 800°C. Recent discoveries of UHP metamorphism within the Seve Nappe Complex derived from the Baltican outer margin (part of the Middle Allochthon) challenged us to present a new tectonic model incorporating exhumation of the deeply subducted continental rocks together with mantle lithosphere peridotites. Majka et al. (2014) introduced a new "under-pressure"-driven exhumation mechanism of rocks buried in subduction systems to depths exceeding 100 km. It was proposed that the diamond-bearing continental rocks were subducted in an arc-continent collision setting and exhumed together with garnet peridotites (incorporated from the lower plate) of sub-Baltic Shield affinity (Brueckner et al., 2004). In this model, the exhumation is mostly driven by the local reduction of pressure as a result of the extraction of forearc lithosphere and leading to the rise of the subducted Seve rocks. Brueckner H.K., van Roermund H.L.M. & Pearson N., 2004. Journal of Petrology, 45, 415-437. Janák M., Van Roermund H.L.M., Majka J. & Gee D.G., 2013. Gondwana Research, 23, 865-879. Klonowska I., Majka J., Janák M., Gee D.G. & Ladenberger A., 2014a. In: Corfu F., Gasser D. & Chew D. M. (eds) New Perspectives on the Caledonides of Scandinavia and Related Areas. Geological Society, London, Special Publications, 390, 321-336. Klonowska I., Janák M., Majka J., & Ko?mi?ska K., 2014b. Geophysical Research Abstracts, Vol. 16, EGU2014-6440-2. Majka J., Rosén Å., Janák M., Froitzheim N., Klonowska I., Manecki M., Sasinková V. & Yoshida K., 2014. Geology, 42, 1107-1110, doi:10.1130

  15. Facies pattern of western Tethyan Middle Triassic black carbonates: The example of Gutenstein Formation in Silica Nappe, Carpathians, Hungary, and its correlation to formations of adjoining areas

    NASA Astrophysics Data System (ADS)

    Hips, Kinga

    2007-01-01

    During the Middle Triassic, a broad carbonate ramp developed at the western end of the Tethys Ocean. In the early phase of the ramp evolution dark grey or black, finely crystalline carbonates were deposited over a considerable part of the ramp. In the Aggtelek Karst, northeastern Hungary, carbonates of the Aggtelek facies of the Silica Nappe are exposed. In the latest Early Triassic, bioturbated mudstones-wackestones and occasionally packstones were formed in the outer ramp zone below the storm wave-base. During the Early Anisian, oxygen-depleted bottom conditions evolved. Gradual changes took place in the sedimentary features of mud-dominated deposits that is attributed to increasing oxygen depletion as a result of density stratification of seawater in the deeper ramp areas. Remarkable ecological and sedimentary changes began with the colonisation by sponges and microbes in the Aggtelek facies area that occurred coevally with a relative sea-level fall. The appearance of the foraminifer Glomospira densa points to late Early Anisian age for these changes. This unit is very variable in lithology and facies compared to the monotonous development of the lower units. Massive limestones and dolomites of microbial origin are ubiquitous; additionally, oolites with micro-oncoids, cross-bedded and cross-laminated bioclastic, peloidal packstones-grainstones, thin-bedded bioclastic wackestones-mudstones, laminated and brecciated dolomites with evaporite pseudomorphs, and dolocretes are also present. Specific microfacies types, i.e. automicrite (varicoloured micrite-microspar groundmass) and cuneiform spongy microfabric preserved by cryptic microbial films, are recognised and interpreted as sponge-microbe mud-mound deposits. The microfacies of pilot samples from Northern Calcareous Alps, Inner Western Carpathians and Dinarides exhibit similar sedimentary features. Tectonic setting, biota evolution after the end-Permian mass extinction, relative sea-level changes and hypersalinity may have been the most important controlling factors of the non-skeletal carbonate factory, which produced dark grey mud-dominated deposits.

  16. The recent fault kinematics in the westernmost part of the Getic nappe system (Eastern Serbia): Evidence from fault slip and focal mechanism data

    NASA Astrophysics Data System (ADS)

    Mladenovi?, Ana; Trivi?, Branislav; Anti?, Milorad; Cvetkovi?, Vladica; Pavlovi?, Radmila; Radovanovi?, Slavica; Fügenschuh, Bernhard

    2014-04-01

    In this study we performed a calculation of the tectonic stress tensor based on fault slip data and all available focal mechanisms in order to determine the principal stress axes and the recent tectonic regime of the westernmost unit of the Getic nappe system (Gornjak-Ravanica Zone, Eastern Serbia). The study is based on a combined dataset involving paleostress analyses, the inversion of focal mechanisms and remote sensing. The results show dominant strike-slip kinematics with the maximal compression axis oriented NNE-SSW. This is compatible with a combined northward motion and counterclockwise rotation of the Adria plate as the controlling factor. However, the local stress field is also shown to be of great importance and is superimposed on the far-field stress. We managed to distinguish three areas with distinct seismic activity. The northern part of the research area is characterized by transtensional tectonics, possibly under the influence of the extension in the areas situated more to the northeast. The central and seismically most active part is dominated by strike-slip tectonics whereas the southern area is slightly transpressional, possibly under the influence of the rigid Moesian Platform situated to the east of the research area. The dominant active fault systems are oriented N-S (to NE-SW) and NW-SE and they occur as structures of either regional or local significance. Regional structures are active in the northern and central part of the study area, while the active fault systems in the southern part are marked as locally important. This study suggests that seismicity of this area is controlled by the release of accumulated stress at local accommodation zones which are favourably oriented in respect to the active regional stress field.

  17. Repeated slip along a major decoupling horizon between crustal-scale nappes of the Central Western Carpathians documented in the Ochtiná tectonic mélange

    NASA Astrophysics Data System (ADS)

    Novotná, N.; Jeřábek, P.; Pitra, P.; Lexa, O.; Racek, M.

    2015-04-01

    The Ochtiná Unit is situated in the ENE-WSW-trending contact zone between two crustal-scale nappes, the upper Gemer Unit and the lower Vepor Unit, in the Central Western Carpathians, Slovakia. The Ochtiná Unit consists mainly of Carboniferous phyllitic schists and sandstones enclosing lenses of diverse lithological nature and contrasting metamorphic history. Peak PT conditions obtained by means of phase equilibrium modelling from lenses of amphibolite and chloritoid schist in this unit indicate 500-600 °C and 4-6.5 kbar and 500-520 °C and 9-11 kbar, respectively. These PT conditions contrast not only with the greenschist-facies metamorphism of dominant phyllite but also with each other documenting two distinct metamorphic field gradients related to Variscan and Alpine metamorphic events. Geochemical data reveal an affinity of the amphibolite lenses similar to Variscan rocks in the basement of the upper Gemer Unit and of the chloritoid schist similar to Alpine rocks in the cover of the lower Vepor Unit. Such heterogeneous lithological and metamorphic record is consistent with a block-in-matrix rock arrangement and the Ochtiná Unit is interpreted as deep seated tectonic mélange. The mélange evolved via repeated slip along the rheologically weak sediments of the Ochtiná Unit during the building and collapse of the Eo-Alpine orogenic wedge of the Central Western Carpathians. Deformation record indicates that the mélange separates two distinct structural domains marked by a decoupled behaviour, i.e. the orogenic suprastructure represented by the Gemer Unit and the infrastructure represented by the Vepor Unit. With this respect, the Ochtiná Unit represents an unusual example of a suprastructure-infrastructure transition zone with its position being controlled by the mechanical weakness of this sedimentary horizon and not by the temperature-dependent rheological transition.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. VIRUS REMOVAL DURING GROUNDWATER RECHARGE: EFFECTS OF INFILTRATION RATE ON ADSORPTION OF POLIOVIRUS TO SOIL

    EPA Science Inventory

    Studies were conducted to determine the influence of infiltration rate on poliovirus removal during groundwater recharge with tertiary-treated wastewater effluents. Experiments were conducted at a uniquely designed, field-situated test recharge basin facility through which some 6...

  20. La structure du rif externe (Maroc): mise au point sur le rôle des décrochements des chevauchements et des glissements gravitaires

    NASA Astrophysics Data System (ADS)

    de Lamotte, Dominique Frizon

    Regional structural field evidence in the Temsamane area, forming the eastern part of the Rifian external zones, indicate that deformation of this area results from N75° left lateral wrenching. The structural data do not fit the nappe interpretation pointed out in Western part of external zone. A review of the geological frame appears necessary; it forms the subject of the present paper. Structurally, the external zones are subdivided into three groups of tectonic units: (a) the olistostromes and associated gravity-driven nappes which crop out all around the Rifian belt ('slided external Rif'); (b) The tectonic windows situated beneath olistostromes and nappes ('basal external Rif'); (c) The central area bounded by NW-SE thrust faults in the Western parts of the belt and by N75° (then N45°) wrench faults in the Eastern parts ('Central Rif'). Concerning the paleogeographic evolution, the deposits of external Rif show a different evolution from their direct foreland but comparable with areas actually situated far eastward: (a) the 'tellian-like domain' shows basinal-type facies similar to facies of the epitellian nappes into Algeria b, (b) the 'Ker Ker-like domain' shows platform facies similar to facies known in West Algerian and Northeast Moroccan forelands. Thus, structural and paleogeographic data show that the all external zones of Rif moved westward along the African margin before sliding southward.

  1. Recharge areas and hydrochemistry of carbonate springs issuing from Semmering Massif, Austria, based on long-term oxygen-18 and hydrochemical data evidence

    NASA Astrophysics Data System (ADS)

    Yehdegho, Beyene; Reichl, Peter

    2002-10-01

    Résumé. Les teneurs en oxygène-18 et l'hydrochimie des sources émergeant du massif de Semmering ont été suivies de manière intensive dans le but de caractériser les zones de recharge et l'évolution hydrochimique. L'effet d'altitude sur le δ18O a été déterminé grâce aux données isotopiques et hydrogéologiques de petites sources de référence, principalement en terrains cristallins; cet effet est d'environ -0,27 et -0,21‰ par 100 m pour les versants respectivement nord et sud du massif. En appliquant ces valeurs, l'altitude moyenne de recharge des sources a été calculée. Pour les sources à fort débit issues des carbonates, elle est comprise entre 1,100 et 1,400 m, compatible avec le cadre topographique et hydrogéologique des calcaires et des dolomies de l'Austro-alpin inférieur alimentant ces sources. La composition chimique des sources des carbonates est dominée par les ions Ca2+, Mg2+, HCO3- et SO42-. Les sources sont presque toutes proches de la saturation par rapport à la calcite, mais sont sous-saturées en dolomite (sauf quelques sources proches de la saturation). Comme cela est habituel en ce qui concerne le dioxyde de carbone fourni par les sols en régions montagneuses, la pCO2 équilibrante moyenne est faible, comprise entre 10-3.0 et 10-2.5 atm (0,1 à 0,3% en volume). En ce qui concerne les variations à long terme, le pH, SIc, Sid et la pCO2 équilibrante sont soumis à des variations saisonnières, alors que les concentrations en Ca2+, Mg2+ et HCO3- ne varient pratiquement pas. En intégrant les résultats de δ18O et les données hydrochimiques, la variabilité altitudinale du chimisme des eaux souterraines des carbonates est démontrée. Reflétant les variations d'activité biologique et des conditions de recharge dans les zones d'alimentation, une covariation négative résulte de l'altitude de recharge et de la pCO2 et la concentration en HCO3- n'est pas modifiée par aucun des termes source ou puits, ce qui fait varier la chimie des carbonates. La pCO2 et la concentration en HCO3- diminuent respectivement d'environ 0,22 unité log (atm) et 38,6 mg/l pour un accroissement de 100 m de l'altitude de recharge. Resumen. Se ha muestreado exhaustivamente el contenido en oxígeno-18 y la hidroquímica de los manantiales existentes en el macizo de Semmering (Austria) con el fin de caracterizar las áreas de recarga y su evolución hidroquímica. Se ha determinado el efecto altitudinal del δ18O con datos isotópicos e hidrogeológicos obtenidos en pequeños manantiales originados en rocas cristalinas que sirven como nivel de referencia; los resultados han sido de -0,27‰ por cada 100 m en la zona Morte del macizo, y de -0,21‰/100 m hacia el Sur. Aplicando estos valores, se ha calculado la altitud promedio a la que se produce su recarga. Para los manantiales de caudal elevado en materiales carbonatados, la altitud de recarga varía entre 1.100 y 1.410 m, cosa que es compatible con el marco topográfico e hidrogeológico de las rocas calizas y dolomíticas Mesozoicas propias del Austroalpino Bajo que los alimenta. La composición hidroquímica de los manantiales carbonatados está dominada por los iones calcio, magnesio, bicarbonato y sulfato. Los manantiales están casi saturados en calcita, pero subsaturados en dolomita, excepto en algunos que parecen hallarse cerca de la saturación. Como caracteriza a los suelos en regiones montañosas, la presión parcial de equilibrio del dióxido de carbono (PCO2) es baja, con valores comprendidos entre 10-3,0 y 10-2,5 atm. A largo plazo, el pH y los valores calculados de los índices de saturación en calcita (SIc) y en dolomita (SId), junto con la PCO2 en equilibrio, evidencian una fuerte estacionalidad; en cambio, las concentraciones de calcio, magnesio y bicarbonato prácticamente no varían. Integrando los resultados de δ18O y de la hidroquímica, se demuestra la variabilidad de la química de aguas subterráneas carbonatadas con respecto a la altitud. Reflejando el cambio sistemático de la actividad biótica y de las condiciones de recarga en la cuenca, se obtiene una correlación negativa entre la altitud de la recarga y la PCO2, mientras que la concentración de bicarbonato no es modificada por términos fuente/sumidero, lo cual atribuye el cambio a la química de los carbonatos. La PCO2 y el bicarbonato disminuyen aproximadamente 0,22 unidades logarítimicas (en atmósferas) y 38,6 mg/l, respectivamente, por cada 100 m de incremento en la altitud de recarga.

  2. 76 FR 54527 - Fourth Meeting: RTCA Special Committee 225: Rechargeable Lithium Batteries and Battery Systems...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-01

    ... Federal Aviation Administration Fourth Meeting: RTCA Special Committee 225: Rechargeable Lithium Batteries...: Notice of RTCA Special Committee 225 meeting: Rechargeable Lithium Batteries and Battery Systems--Small... Special Committee 225: Rechargeable Lithium Batteries and Battery Systems--Small and Medium Sizes....

  3. 76 FR 38741 - Third Meeting: RTCA Special Committee 225: Rechargeable Lithium Batteries and Battery Systems...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-01

    ... Federal Aviation Administration Third Meeting: RTCA Special Committee 225: Rechargeable Lithium Batteries...: Notice of RTCA Special Committee 225 meeting: Rechargeable Lithium Batteries and Battery Systems--Small... Special Committee 225: Rechargeable Lithium Batteries and Battery Systems--Small and Medium Sizes....

  4. 76 FR 22161 - Second Meeting: RTCA Special Committee 225: Rechargeable Lithium Batteries and Battery Systems...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-20

    ... Federal Aviation Administration Second Meeting: RTCA Special Committee 225: Rechargeable Lithium Batteries...: Notice of RTCA Special Committee 225 meeting: Rechargeable Lithium Batteries and Battery Systems--Small... Special Committee 225: Rechargeable Lithium Batteries and Battery Systems--Small and Medium Sizes....

  5. 76 FR 6180 - First Meeting: RTCA Special Committee 225: Rechargeable Lithium Batteries and Battery Systems...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-03

    ... Federal Aviation Administration First Meeting: RTCA Special Committee 225: Rechargeable Lithium Batteries...: Notice of RTCA Special Committee 225 meeting: Rechargeable Lithium Batteries and Battery Systems--Small... Special Committee 225: Rechargeable Lithium Batteries and Battery Systems--Small and Medium Sizes....

  6. 77 FR 2437 - Special Conditions: Gulfstream Aerospace Corporation, Model GVI Airplane; Rechargeable Lithium...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-18

    ... Privacy Act Statement can be found in the Federal Register published on April 11, 2000 (65 FR 19477-19478...; Rechargeable Lithium Batteries and Rechargeable Lithium- Battery Systems AGENCY: Federal Aviation... have a novel or unusual design feature associated with the installation of rechargeable...

  7. Rechargeable Li-CO2 batteries with carbon nanotubes as air cathodes.

    PubMed

    Zhang, Xin; Zhang, Qiang; Zhang, Zhang; Chen, Yanan; Xie, Zhaojun; Wei, Jinping; Zhou, Zhen

    2015-10-01

    Rechargeable Li-CO2 batteries offer great promise by combining carbon capture and energy technology. However, the discharge product Li2CO3 is difficult to decompose upon recharging. In this work, carbon nanotubes (CNTs) with high electrical conductivity and porous three-dimensional networks were firstly explored as air cathodes for rechargeable Li-CO2 batteries. PMID:26290015

  8. LOCALIZED RECHARGE INFLUENCES ON MTBE TRANSPORT AND WELL PLACEMENT CONSIDERATIONS

    EPA Science Inventory

    Vertical characterization of a gasoline release site at East Patchogue, New York showed that methyl tert-butyl ether (MTBE) and aromatic plumes "dived" as they passed beneath a sand pit. That this behavior was caused by aquifer recharge was shown by two pieces of evidence. Fir...

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

    NASA Astrophysics Data System (ADS)

    Rossetto, Rudy

    2015-04-01

    On October the 3rd 2014, a one-day Workshop on Managed Aquifer Recharge (MAR) experiences in Italy took place at the GEOFLUID fair in Piacenza. It was organized within the framework of the EIP AG 128 - MAR Solutions - Managed Aquifer Recharge Strategies and Actions and the EU FPVII MARSOL. The event aimed at showcasing present experiences on MAR in Italy while at the same time starting a network among all the Institutions involved. In this contribution, we discuss the state of MAR application in Italy and summarize the outcomes of that event. In Italy aquifer recharge is traditionally applied unintentionally, by increasing riverbank filtration or because of excess irrigation. A certain interest for artificial recharge of aquifers arose at the end of the '70s and the beginning of the '80s and tests have been carried out in Tuscany, Veneto and Friuli Venezia Giulia. During the last years some projects on aquifer recharge were co-financed by the European Commission mainly through the LIFE program. Nearly all of them use the terminology of artificial recharge instead of MAR. They are: - TRUST (Tool for regional - scale assessment of groundwater storage improvement in adaptation to climate change, LIFE07 ENV/IT/000475; Marsala 2014); - AQUOR (Implementation of a water saving and artificial recharging participated strategy for the quantitative groundwater layer rebalance of the upper Vicenza's plain - LIFE 2010 ENV/IT/380; Mezzalira et al. 2014); - WARBO (Water re-born - artificial recharge: innovative technologies for the sustainable management of water resources, LIFE10 ENV/IT/000394; 2014). While the TRUST project dealt in general with aquifer recharge, AQUOR and WARBO focused essentially on small scale demonstration plants. Within the EU FPVII-ENV-2013 MARSOL project (Demonstrating Managed Aquifer Recharge as a Solution to Water Scarcity and Drought; 2014), a dedicated monitoring and decision support system is under development to manage recharge at a large scale riverbank filtration plant, worth 15 Mm3/year in Lucca (Tuscany; Borsi et al. 2014). In 2014, the Regional Authority of Emilia Romagna started a pilot on the Marecchia River fan using a recharge basin to alleviate water scarcity in the Rimini area as results of drought periods (Severi et al. 2014). To apply MAR techniques on a large scale is of particular interest the possibility to allow farmer's associations or drainage consortiums to play an important role in storing excess rainfall water in aquifers. Few hectares of land in rural areas may be dedicated to MAR plants, transforming a traditionally water consumer sector in one preserving it - opportunities are then linked to the provision of water related ecosystem services. Aquifer recharge is allowed in Italy only since September 2013, but still a regulatory framework is missing. Hopefully, this regulatory scheme will benefit from previous and on-going experiences. Dissemination of MAR scientific findings and technical know-how among governing authorities and the general public is crucial for the application of MAR techniques. Fundings for setting up new MAR plants may be available at national level. At the same time, lack of knowledge at intermediate governing bodies level is preventing the application of these techniques (i.e. building of small dams is favored although less convenient by several points of view in respect of MAR plants). Finally, it is of outmost importance to define which are the financial instruments to sustain these water infrastructures, so to guarantee not only their set up, but also routinely operations, opening as such a new market in the water sector. Acknowledgments This paper is co-financed within the framework of the EU FP7-ENV-2013-WATER-INNO-DEMO MARSOL (Grant Agreement n. 619120). References Borsi, I., Mazzanti, G., Barbagli, A., Rossetto, R., 2014. The riverbank filtration plant in S. Alessio (Lucca): monitoring and modeling activity within EU the FP7 MARSOL project. Acque Sotterranee - Italian Journal of Groundwater, Vol. 3, n. 3/137 Marsala, V. (2014). LIFE+ TRUST project: tool to assist the implementation of the Framework Directive 2000/60/CE, methodology and results. Acque Sotterranee - Italian Journal of Groundwater, Vol. 3, n. 3/137 MARSOL (2014). Demonstrating Managed Aquifer Recharge as a Solution to Water Scarcity and Drought www.marsol.eu [accessed 4 January 2015] Mezzalira, G., Niceforo, U., Gusmaroli, G. (2014). Forested infiltration areas (FIA); principles, experiences, perspectives. Acque Sotterranee - Italian Journal of Groundwater, Vol. 3, n. 3/137 Severi, P., Bonzi, L., Ferrari, V., Pellegrino, I. (2014). Managed aquifer recharge in the Marecchia alluvial fan (Rimini - Italy), start of the test and first results. Acque Sotterranee - Italian Journal of Groundwater, Vol. 3, n. 3/137 WARBO, 2014. WATER RE-BORN - Artificial Recharge. Innovative Technologies for the Sustainable Management of Water Resources. http://www.warbo-life.eu/ [accessed 8 August 2014

  10. Estimating High Plains Aquifer Recharge Using Temperature Probes

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  11. Electrolytes for rechargeable lithium batteries. Research and development technical report

    SciTech Connect

    Hunger, H.F.

    1981-09-01

    Theoretical considerations predict increased stability of cyclic ethers and diethers against reductive cleavage by lithium if the ethers have 2 methyl substitution. Diethers are solvents with low viscosity which are desirable for high rate rechargeable lithium batteries. Synergistic, mixed solvent effects increase electrolyte conductance and rate capability of lithium intercalating cathodes.

  12. Trench infiltration for managed aquifer recharge to permeable bedrock

    USGS Publications Warehouse

    Heilweil, V.M.; Watt, D.E.

    2011-01-01

    Managed aquifer recharge to permeable bedrock is increasingly being utilized to enhance resources and maintain sustainable groundwater development practices. One such target is the Navajo Sandstone, an extensive regional aquifer located throughout the Colorado Plateau of the western United States. Spreading-basin and bank-filtration projects along the sandstone outcrop's western edge in southwestern Utah have recently been implemented to meet growth-related water demands. This paper reports on a new cost-effective surface-infiltration technique utilizing trenches for enhancing managed aquifer recharge to permeable bedrock. A 48-day infiltration trench experiment on outcropping Navajo Sandstone was conducted to evaluate this alternative surface-spreading artificial recharge method. Final infiltration rates through the bottom of the trench were about 0.5 m/day. These infiltration rates were an order of magnitude higher than rates from a previous surface-spreading experiment at the same site. The higher rates were likely caused by a combination of factors including the removal of lower permeability soil and surficial caliche deposits, access to open vertical sandstone fractures, a reduction in physical clogging associated with silt and biofilm layers, minimizing viscosity effects by maintaining isothermal conditions, minimizing chemical clogging caused by carbonate mineral precipitation associated with algal photosynthesis, and diminished gas clogging associated with trapped air and biogenic gases. This pilot study illustrates the viability of trench infiltration for enhancing surface spreading of managed aquifer recharge to permeable bedrock. ?? 2010.

  13. DELINEATING KARST RECHARGE AREAS AT ONONDAGA CAVE STATE PARK

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  14. Moderate temperature rechargeable NaNiS2 cells

    NASA Technical Reports Server (NTRS)

    Abraham, K. M.

    1983-01-01

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

  15. 30 CFR 56.4203 - Extinguisher recharging or replacement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Extinguisher recharging or replacement. 56.4203 Section 56.4203 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES...

  16. 30 CFR 56.4203 - Extinguisher recharging or replacement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Extinguisher recharging or replacement. 56.4203 Section 56.4203 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES...

  17. 30 CFR 56.4203 - Extinguisher recharging or replacement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Extinguisher recharging or replacement. 56.4203 Section 56.4203 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES...

  18. 30 CFR 56.4203 - Extinguisher recharging or replacement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Extinguisher recharging or replacement. 56.4203 Section 56.4203 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES...

  19. 30 CFR 56.4203 - Extinguisher recharging or replacement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Extinguisher recharging or replacement. 56.4203 Section 56.4203 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES...

  20. 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...

  1. Effects of variations in recharge on groundwater quality

    USGS Publications Warehouse

    Whittemore, D.O.; McGregor, K.M.; Marotz, G.A.

    1989-01-01

    The predominant regional effect of recharge on municipal groundwater quality in Kansas is the dilution of mineralized water in aquifers with relatively shallow water tables. The individual dissolved constituents contributing most to the water-quality variations are sulfate and chloride, and the calcium and sodium accompanying them, which are derived from the dissolution of evaporite minerals within the aquifer or from saline formation water in bedrock underlying the aquifer. The relationship between recharge and groundwater-quality variation can be quantified by associating certain climatic indices, especially the Palmer Drought Index, with quality observations. The response time of the maximum water-quality change relative to the occurrence of drought or substantial recharge ranges from a month to 3 years depending on the aquifer characteristics, and is generally proportional to the saturated thickness and specific yield. The response time is also affected by discharge to and recharge from nearby streams and by the well construction, particularly the placement of the screened interval, and pumping stress. ?? 1989.

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

    EPA Science Inventory

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

  3. Oxygen electrodes for rechargeable alkaline fuel cells-II

    NASA Technical Reports Server (NTRS)

    Swette, L.; Kackley, N.

    1989-01-01

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

  4. On hydrologic prediction using NEXRAD Radar for recharge estimation

    NASA Astrophysics Data System (ADS)

    Vieux, B. E.; Moreno, M.; Looper, J.

    2008-12-01

    Advances in water balance and recharge estimation have been aided through radar detection of complex precipitation patterns and distributed hydrologic modeling. Predicting the hydrologic components of the water balance depends on accurate determination of precipitation input, runoff, infiltration, recharge, and evapotranspiration. The importance of gauge-corrected radar input is demonstrated through characterizing the climatology at basin and subbasin scales. The difference in runoff volume obtained from corrected and uncorrected radar input is significant even at length scales on the order of 100's of km. Bias correction of the NEXRAD precipitation estimates from show that there is a decline in prediction accuracy. Random errors that remain after bias correction are expected to cancel out over time; however, uncorrected radar introduces error in the hydrologic water balance. Actual ET is an important factor affecting recharge in the upper reaches of the Blue River and the Arbuckle-Simpson aquifer. Characterizing local precipitation rates becomes a critical determinant in understanding recharge rates to the aquifer, runoff, and springflow.

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

    SciTech Connect

    Banner, J.A.; Winchester, C.S.

    1996-12-31

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

  6. Reticulation des fibres lignocellulosiques

    NASA Astrophysics Data System (ADS)

    Landrevy, Christel

    Pour faire face à la crise économique la conception de papier à valeur ajoutée est développée par les industries papetières. Le but de se projet est l'amélioration des techniques actuelles de réticulation des fibres lignocellulosiques de la pâte à papier visant à produire un papier plus résistant. En effet, lors des réactions de réticulation traditionnelles, de nombreuses liaisons intra-fibres se forment ce qui affecte négativement l'amélioration anticipée des propriétés physiques du papier ou du matériau produit. Pour éviter la formation de ces liaisons intra-fibres, un greffage sur les fibres de groupements ne pouvant pas réagir entre eux est nécessaire. La réticulation des fibres par une réaction de « click chemistry » appelée cycloaddition de Huisgen entre un azide et un alcyne vrai, catalysée par du cuivre (CuAAC) a été l'une des solutions trouvée pour remédier à ce problème. De plus, une adaptation de cette réaction en milieux aqueux pourrait favoriser son utilisation en milieu industriel. L'étude que nous désirons entreprendre lors de ce projet vise à optimiser la réaction de CuAAC et les réactions intermédiaires (propargylation, tosylation et azidation) sur la pâte kraft, en milieu aqueux. Pour cela, les réactions ont été adaptées en milieu aqueux sur la cellulose microcristalline afin de vérifier sa faisabilité, puis transférée à la pâte kraft et l'influence de différents paramètres comme le temps de réaction ou la quantité de réactifs utilisée a été étudiée. Dans un second temps, une étude des différentes propriétés conférées au papier par les réactions a été réalisée à partir d'une série de tests papetiers optiques et physiques. Mots Clés Click chemistry, Huisgen, CuAAC, propargylation, tosylation, azidation, cellulose, pâte kraft, milieu aqueux, papier.

  7. Ecohydrologic process modeling of mountain block groundwater recharge.

    PubMed

    Magruder, Ian A; Woessner, William W; Running, Steve W

    2009-01-01

    Regional mountain block recharge (MBR) is a key component of alluvial basin aquifer systems typical of the western United States. Yet neither water scientists nor resource managers have a commonly available and reasonably invoked quantitative method to constrain MBR rates. Recent advances in landscape-scale ecohydrologic process modeling offer the possibility that meteorological data and land surface physical and vegetative conditions can be used to generate estimates of MBR. A water balance was generated for a temperate 24,600-ha mountain watershed, elevation 1565 to 3207 m, using the ecosystem process model Biome-BGC (BioGeochemical Cycles) (Running and Hunt 1993). Input data included remotely sensed landscape information and climate data generated with the Mountain Climate Simulator (MT-CLIM) (Running et al. 1987). Estimated mean annual MBR flux into the crystalline bedrock terrain is 99,000 m(3) /d, or approximately 19% of annual precipitation for the 2003 water year. Controls on MBR predictions include evapotranspiration (radiation limited in wet years and moisture limited in dry years), soil properties, vegetative ecotones (significant at lower elevations), and snowmelt (dominant recharge process). The ecohydrologic model is also used to investigate how climatic and vegetative controls influence recharge dynamics within three elevation zones. The ecohydrologic model proves useful for investigating controls on recharge to mountain blocks as a function of climate and vegetation. Future efforts will need to investigate the uncertainty in the modeled water balance by incorporating an advanced understanding of mountain recharge processes, an ability to simulate those processes at varying scales, and independent approaches to calibrating MBR estimates. PMID:19702780

  8. Enhanced recharge and karst, Edwards aquifer, south central Texas

    SciTech Connect

    Hammond, W.W. Jr. . Center for Water Research)

    1993-02-01

    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.

  9. Groundwater suitability recharge zones modelling - A GIS application

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  11. The simulation of the recharging method of active medical implant based on Monte Carlo method

    NASA Astrophysics Data System (ADS)

    Kong, Xianyue; Song, Yong; Hao, Qun; Cao, Jie; Zhang, Xiaoyu; Dai, Pantao; Li, Wansong

    2014-11-01

    The recharging of Active Medical Implant (AMI) is an important issue for its future application. In this paper, a method for recharging active medical implant using wearable incoherent light source has been proposed. Firstly, the models of the recharging method are developed. Secondly, the recharging processes of the proposed method have been simulated by using Monte Carlo (MC) method. Finally, some important conclusions have been reached. The results indicate that the proposed method will help to result in a convenient, safe and low-cost recharging method of AMI, which will promote the application of this kind of implantable device.

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

    USGS Publications Warehouse

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

    1979-01-01

    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)

  13. Transient,spatially-varied recharge for groundwater modeling

    NASA Astrophysics Data System (ADS)

    Assefa, Kibreab; Woodbury, Allan

    2013-04-01

    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.

  14. Transient, spatially-varied recharge for groundwater modeling

    NASA Astrophysics Data System (ADS)

    Assefa, K.; Woodbury, A. D.

    2012-12-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    As demands on groundwater increase, artificial recharge is becoming a common method for enhancing groundwater supply. The Llobregat River is a strategic water supply resource to the Barcelona metropolitan area (Catalonia, NE Spain). Aquifer overexploitation has leaded to both a decrease of groundwater level and seawater intrusion, with the consequent deterioration of water quality. In the middle section of the aquifer, in Sant Vicenç del Horts, decantation and infiltration ponds recharged by water from the Llobregat River (highly affected from wastewater treatment plant effluents), were installed in 2007, in the framework of the ENSAT Life+ project. At the bottom of the infiltration pond, a vegetal compost layer was installed to promote the growth of bacteria, to induce denitrification and to create favourable conditions for contaminant biodegradation. This layer consists on a mixture of compost, aquifer material, clay and iron oxide. Understanding the fate of contaminants, such as nitrate, during artificial aquifer recharge is required to evaluate the impact of artificial recharge in groundwater quality. In order to distinguish the source of nitrate and to evaluate the capability of the organic reactive layer to induce denitrification, a multi-isotopic approach coupled with hydrogeochemical data was performed. Groundwater samples, as well as river samples, were sampled during artificial and natural recharge periods. The isotopic analysis included: δ15N and δ18O of dissolved nitrate, δ34S and δ18O of dissolved sulphate, δ13C of dissolved inorganic carbon, and δ2H and δ18O of water. Dissolved nitrate isotopic composition (δ15NNO3 from +9 to +21 o and δ18ONO3 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 ɛN 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.

  16. The spatial and temporal variability of groundwater recharge in a forested basin in northern Wisconsin

    USGS Publications Warehouse

    Dripps, W.R.; Bradbury, K.R.

    2010-01-01

    Recharge varies spatially and temporally as it depends on a wide variety of factors (e.g. vegetation, precipitation, climate, topography, geology, and soil type), making it one of the most difficult, complex, and uncertain hydrologic parameters to quantify. Despite its inherent variability, groundwater modellers, planners, and policy makers often ignore recharge variability and assume a single average recharge value for an entire watershed. Relatively few attempts have been made to quantify or incorporate spatial and temporal recharge variability into water resource planning or groundwater modelling efforts. In this study, a simple, daily soil-water balance model was developed and used to estimate the spatial and temporal distribution of groundwater recharge of the Trout Lake basin of northern Wisconsin for 1996-2000 as a means to quantify recharge variability. For the 5 years of study, annual recharge varied spatially by as much as 18 cm across the basin; vegetation was the predominant control on this variability. Recharge also varied temporally with a threefold annual difference over the 5-year period. Intra-annually, recharge was limited to a few isolated events each year and exhibited a distinct seasonal pattern. The results suggest that ignoring recharge variability may not only be inappropriate, but also, depending on the application, may invalidate model results and predictions for regional and local water budget calculations, water resource management, nutrient cycling, and contaminant transport studies. Recharge is spatially and temporally variable, and should be modelled as such. Copyright ?? 2009 John Wiley & Sons, Ltd.

  17. Borehole logging at the COSC-1 drill hole: a new dataset of in-situ geophysical properties through the lower Seve Nappe Complex

    NASA Astrophysics Data System (ADS)

    Berthet, Théo; Alm, Per-Gunnar; Wenning, Quinn; Almqvist, Bjarne; Kück, Jochem; Hedin, Peter

    2015-04-01

    The Collisional Orogeny in the Scandinavian Caledonides (COSC) drilling project supported by the International Continental Drilling Program was designed to study mountain building processes in a deeply eroded Paleozoic orogen. The first half of this project, COSC-1, targeted the lower part of the high grade Seve Nappe Complex and its basal thrust zone near Åre in the Jämtland county, Sweden. From May to August 2014, the COSC drilling crew drilled to a depth of 2496 m from the surface with an almost fully recovered core sample. During this drilling period, four borehole-logging runs have been conducted by Lund University with a low impact on drilling schedule and two supplementary ones once the drilling was completed. Three-Arm Caliper, Electrical Logging, Sidewall Density, Flowing Fluid Electric Conductivity, High Resolution Acoustic Televiewer and Full Waveform Sonic sondes have been used to investigate in-situ physical properties of the borehole. In addition, the ICDP operational support group has conducted two continuous borehole-logging runs from the surface to the bottom of the COSC-1 borehole in September and October. Due to technical problems, some of the planned logging have not been completed, however natural gamma, rock resistivity, magnetic susceptibility, K/Th/U concentration, temperature and fluid conductivity have been measured all along the borehole. We used the continuous natural gamma log from the ICDP logging group as the depth reference to depth-match and stack the composite borehole logging done during the drilling. These borehole logging operations result in reliable continuous data of resistivity, density, velocity, magnetic susceptibility, K/Th/U concentration, temperature, fluid conductivity, pressure, diameter as well as an image (amplitude and travel time of reflected ultrasounds) of the borehole till its bottom. Only the density, velocity and image datasets stop at 1600 m depth due to instrumentation limits. Preliminary conclusions from the borehole logging data show a stripped pattern of density correlated with velocity, which underlines the varying composition of the gneisses observed in the first 1600 m core. Pressure and temperature condition at the bottom of the borehole reach almost reach 55°C and 25 MPa. Moreover, some of the fracture zones observed in the borehole image provided by the acoustic televiewer seem to be associated with hydraulic active zones detected by spikes in the fluid conductivity logs and can also be correlated to those seen in the drill core.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  19. Recharge Estimation Using Water, Chloride and Isotope Mass Balances

    NASA Astrophysics Data System (ADS)

    Dogramaci, S.; Firmani, G.; Hedley, P.; Skrzypek, G.; Grierson, P. F.

    2014-12-01

    Discharge of surplus mine water into ephemeral streams may elevate groundwater levels and alter the exchange rate between streams and underlying aquifers but it is unclear whether volumes and recharge processes are within the range of natural variability. Here, we present a case study of an ephemeral creek in the semi-arid subtropical Hamersley Basin that has received continuous mine discharge for more than five years. We used a numerical model coupled with repeated measurements of water levels, chloride concentrations and the hydrogen and oxygen stable isotope composition (δ2H and δ18O) to estimate longitudinal evapotranspiration and recharge rates along a 27 km length of Weeli Wolli Creek. We found that chloride increased from 74 to 120 mg/L across this length, while δ18O increased from -8.24‰ to -7.00‰. Groundwater is directly connected to the creek for the first 13 km and recharge rates are negligible. Below this point, the creek flows over a highly permeable aquifer and water loss by recharge increases to a maximum rate of 4.4 mm/d, which accounts for ~ 65% of the total water discharged to the creek. Evapotranspiration losses account for the remaining ~35%. The calculated recharge from continuous flow due to surplus water discharge is similar to that measured for rainfall-driven flood events along the creek. Groundwater under the disconnected section of the creek is characterised by a much lower Cl concentration and more depleted δ18O value than mining discharge water but is similar to flood water generated by large episodic rainfall events. Our results suggest that the impact of recharge from continuous flow on the creek has not extended beyond 27 km from the discharge point. Our approach using a combination of hydrochemical and isotope methods coupled with classical surface flow hydraulic modelling allowed evaluation of components of water budget otherwise not possible in a highly dynamic system that is mainly driven by infrequent but large episodic floods.

  20. Geophysical Methods for Improved Understanding of Managed Aquifer Recharge (Invited)

    NASA Astrophysics Data System (ADS)

    Pidlisecky, A.; Nenna, V.; Knight, R. J.

    2013-12-01

    Managed aquifer recharge is increasingly being used as a means of augmenting groundwater supplies. With the increased use, questions arise regarding the suitability of sites for such operations, as well as the operational efficiency of these systems. In this work we specifically look at MAR using an artificial recharge pond. There are two operational challenges commonly faced in artificial recharge ponds: 1) A decrease in infiltration rate of water into the subsurface during operating; this limits the amount of stored water. 2) Low recovery rates of the stored water. Addressing both of these challenges requires sufficient information about the spatial and temporal variation in governing hydrologic properties and processes. Geophysical methods provide a novel way of obtaining such information from the region beneath a recharge pond. A study of the Harkins Slough Recharge Pond, near Watsonville California, presented a unique opportunity to develop and test geophysical methods, specifically for improved understanding off MAR. At this site we deployed a series of geophysical sensors aimed at addressing the two operational challenges at the site. We first addressed the question: What is controlling the decrease in filtration rate? The development and installation of electrical conductivity probes beneath the pond allowed us to monitor changes in the top ~1 m over a 4-month period. This dataset revealed that clogging in the top ~10 cm was responsible for the decreased infiltration rate. These 1D data were augmented by a time-lapse 2D ERT dataset that shows significant lateral variability in infiltration at the site. The second question we addressed was: Why is the recovery rate so low? Using a combination of cone-penetrometer testing and seismic reflection data, we developed a subsurface model that suggested there was a thin clay layer that may be impeding the flow of water to the recovery wells. To further understand this, we developed electrical conductivity probes, containing pore pressure transducers, to monitor changes in electrical conductivity and fluid pressure to a depth of 30 m. The data acquired with these probes clearly showed that the subsurface clay layer was impeding flow to the screened zone of the recovery wells. The findings at the site demonstrate the value of geophysics obtaining information regarding the siting and operation of artificial recharge ponds.

  1. Des Vents et des Jets Astrophysiques

    NASA Astrophysics Data System (ADS)

    Sauty, C.

    Plasma outflows from a central gravitating object are a widespread phenomenon in astrophysics. They include the solar and stellar winds, jets from Young Stellar Objects, jets from compact stellar objects and extra-galactic jets associated with Active Galactic Nuclei and quasars. Beyond this huge zoology, a common theoretical ground exists. The aim of this review is to present qualitatively the various theories of winds (Part 1) and how different astrophysical domains interplay. A more or less complete catalog of the ideas proposed for explaining the acceleration and the morphologies of winds and jets is intended. All this part avoids getting into any mathematical formalism. Some macroscopic properties of such outflows may be described by solving the time-independent and axisymmetric magnetohydrodynamic equations. This formalism, underlying most of the theories, is presented in Part 2. It helps to introduce quantitatively the free integrals that such systems possess. Those integrals play an important role in the basic physics of acceleration and collimation, in particular the mass loss rate, the angular momentum loss rate and the energy of the magnetic rotator. Most of the difficulty in modelling flows lies in the necessity to cross critical points, characteristic of non linear equations. The physical nature and the location of such critical points is debated because they are the clue towards the resolution. We thus introduce the notions of topology and critical points (Parts 3 and 4) from the simplest hydrodynamic and spherically symmetric case to the most sophisticated, MHD and axisymmetric cases. Particular attention is given to self-similar models which allows to give some general and simple ideas on the problem due to their semi-analytical treatment. With the use of these notions, a more quantitative comparison of the various models is given (Parts 3 and 4), especially on the shape of the flows. It is thus shown that magnetic collimation of winds into jets is a well expected result from the theory. Although, collimation may be conical, paraboloidal or cylindrical (Part 4), cylindrical collimation is the more likely to occur. The shape of outflows may then be used as a tool to predict physical conditions on the flows or on their source. L'éjection continue de plasma autour d'objets massifs est un phénomène largement répandu en astrophysique, que ce soit sous la forme du vent solaire, de vents stellaires, de jets d'étoiles en formation, de jets stellaires autour d'objets compacts ou de jets extra-galactiques. Cette zoologie diversifiée fait pourtant l'objet d'un commun effort de modélisation. Le but de cette revue est d'abord de présenter qualitativement le développement, depuis leur origine, des diverses théories de vents (Partie 1) et l'inter disciplinarité dans ce domaine. Il s'agit d'une énumération, plus ou moins exhaustive, des idées proposées pour expliquer l'accélération et la morphologie des vents et des jets, accompagnée d'une présentation sommaire des aspects observationnels. Cette partie s'abstient de tout aspect faisant appel au formalisme mathématique. Ces écoulements peuvent être décrits, au moins partiellement, en résolvant les équations magnétohydrodynamiques, axisymétriques et stationnaires. Ce formalisme, à la base de la plupart des théories, est exposé dans la Partie 2. Il permet d'introduire quantitativement les intégrales premières qu'un tel système possède. Ces dernières sont amenées à jouer un rôle important dans la compréhension des phénomènes d'accélération ou de collimation, en particulier le taux de perte de masse, le taux de perte de moment angulaire ou l'énergie du rotateur magnétique. La difficulté de modélisation réside dans l'existence de points critiques, propres aux équations non linéaires, qu'il faut franchir. La nature physique et la localisation de ces points critiques fait l'objet d'un débat important car ils sont la clef de voute de la résolution. Nous introduisons donc la notion de topologie des points critiques (Parties 3 et 4

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

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

    SciTech Connect

    Garcia-Diaz, Brenda; Kane, Marie; Au, Ming

    2010-10-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  6. Geochemical evidence of natural recharge in Larderello and Castelnuovo areas

    SciTech Connect

    Calore, C.; Celati, R.; D'Amore, F.; Noto, P.

    1982-01-01

    The spatial variations of the isotopic composition of the fluid in Castelnuovo and the southern zone of Larderello were, in the early 1970s, interpreted as the effects of a natural recharge. It was subsequently noted that this distribution might be the result of the condensation process, at least in areas with no tritium. In order to further investigate this problem a study was undertaken of the spatial and temporal variations in the gas/steam ratio and in the isotopic composition. Preliminary interpretation of the results of this study confirms that the evolution of fluid composition in this area is due to a mixing between the fluid originally present in the reservoir and recent meteoric waters. The area affected by natural recharge is, moreover, in continual expansion.

  7. Recharging behavior of nitrogen-centers in ZnO

    SciTech Connect

    Philipps, Jan M. Meyer, Bruno K.; Hofmann, Detlev M.; Stehr, Jan E.; Buyanova, Irina; Tarun, Marianne C.; McCluskey, Matthew D.

    2014-08-14

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

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

    SciTech Connect

    Cho, Ki Yeon; Kwon, Young Il; Youn, Jae Ryoun; Song, Young Seok

    2013-08-01

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

  9. Zinc electrode and rechargeable zinc-air battery

    DOEpatents

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

    1989-01-01

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

  10. Cartographie des disques

    NASA Astrophysics Data System (ADS)

    Hameury, Jean-Marie

    2001-01-01

    Two techniques are frequently used to produce images of the accretion disc in an eclipsing binary: eclipse mapping and Doppler tomography. From the light curve, one can deduce the radial distribution of the effective temperature, assuming axial symmetry. On the other hand, from the variation of the line profile one can reconstruct an image in the velocity space, which can be converted into a real image if one knows the kinematics of the system. Deux techniques sont couramment utilisées pour obtenir des images des disques dans les systèmes binaires à éclipses. En utilisant la courbe de lumière, on peut remonter à la distribution radiale de la brillance de surface, en supposant que celle-ci a une symètrie axiale. D'autre part, les profils de raies renseignent sur la distribution de vitesse des régions émissives leur variation temporelle permet de réaliser une image dans l'espace des vitesses, que l'on peut ensuite transformer en carte dans l'espace (x,y) si on connaît la cinématique du système.

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

    USGS Publications Warehouse

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

    2002-01-01

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

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

    USGS Publications Warehouse

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

    1998-01-01

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

  13. Electrochemically Stable Cathode Current Collectors for Rechargeable Magnesium Batteries

    SciTech Connect

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

    2014-01-01

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

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

    SciTech Connect

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

    2001-05-13

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

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

    SciTech Connect

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

    2001-11-01

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

  16. Evaluation of Recharge Potential at Crater U5a (WISHBONE)

    SciTech Connect

    Richard H. French; Samuel L. Hokett

    1998-11-01

    Radionuclides are present both below and above the water table at the Nevada Test Site (NTS), as the result of underground nuclear testing. Mobilization and transport of radionuclides from the vadose zone is a complex process that is influenced by the solubility and sorption characteristics of the individual radionuclides, as well as the soil water flux. On the NTS, subsidence craters resulting from testing underground nuclear weapons are numerous, and many intercept surface water flows. Because craters collect surface water above the sub-surface point of device detonation, these craters may provide a mechanism for surface water to recharge the groundwater aquifer system underlying the NTS. Given this situation, there is a potential for the captured water to introduce contaminants into the groundwater system. Crater U5a (WISHBONE), located in Frenchman Flat, was selected for study because of its potentially large drainage area, and significant erosional features, which suggested that it has captured more runoff than other craters in the Frenchman Flat area. Recharge conditions were studied in subsidence crater U5a by first drilling boreholes and analyzing the collected soil cores to determine the soil properties and moisture conditions. This information, coupled with a 32-year precipitation record, was used to conduct surface and vaodse zone modeling. Surface water modeling predicted that approximately 13 ponding events had occurred during the life of the crater. Vadose zone modeling indicated that since the crater's formation approximately 5,900 m3 of water were captured by the crater. Of this total, approximately 5,200 m3 of potential recahrge may have occurred, and the best estimates of annual average potential recharge rates lie between 36 and 188 cm of water per year. The term potential is used here to indicate that the water is not technically recharged because it has not yet reached the water table.

  17. Development of Carbon Anode for Rechargeable Lithium Cells

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

    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.

  18. An accounting/recharge system for educational media services.

    PubMed

    Grover, P L; Lindstrom, R A

    1980-07-01

    An accounting/recharge system can aid the educational media manager in more efficient use of resources to accomplish organizational goals. A system for cataloging, billing, and analyzing the productivity and relative efficiency of media production and services is outlined. Benefits derived from such a system include an improved basis for planning and rationing of resources, greater efficiency in utilization and production, improved internal communications, and an increased sense of accomplishment. PMID:6156156

  19. Recharge in Volcanic Systems: Evidence from Isotope Profiles of Phenocrysts

    PubMed

    Davidson; Tepley

    1997-02-01

    Strontium isotope ratios measured from core to rim across plagioclase feldspar crystals can be used to monitor changes in the isotope composition of the magma from which they grew. In samples from three magma systems from convergent margin volcanoes, sudden changes in major element composition, petrographic features, and strontium isotope composition were found to correspond to discrete magmatic events, most likely repeated recharge of more mafic magma with lower ratios of strontium-87 to strontium-86 into a crustally contaminated magma. PMID:9012348

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

    USGS Publications Warehouse

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

    1983-01-01

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

  1. Recent developments and likely advances in lithium rechargeable batteries

    NASA Astrophysics Data System (ADS)

    Ritchie, A. G.

    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 improve safety. Some research has been reported on sodium-ion batteries.

  2. Focused Recharge in a Semi-arid Riparian Zone

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Fouchard, D.; Taylor, J. B.

    1987-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Nagasubramanian, Ganesan; Attia, Alan I.

    1992-01-01

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

  5. Changes in vegetation diversity caused by artificial recharge

    USGS Publications Warehouse

    Van Hylckama, T. E. A.

    1979-01-01

    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.

  6. Identification of priority organic compounds in groundwater recharge of China.

    PubMed

    Li, Zhen; Li, Miao; Liu, Xiang; Ma, Yeping; Wu, Miaomiao

    2014-09-15

    Groundwater recharge using reclaimed water is considered a promising method to alleviate groundwater depletion, especially in arid areas. Traditional water treatment systems are inefficient to remove all the types of contaminants that would pose risks to groundwater, so it is crucial to establish a priority list of organic compounds (OCs) that deserve the preferential treatment. In this study, a comprehensive ranking system was developed to determine the list and then applied to China. 151 OCs, for which occurrence data in the wastewater treatment plants were available, were selected as candidate OCs. Based on their occurrence, exposure potential and ecological effects, two different rankings of OCs were established respectively for groundwater recharge by surface infiltration and direct aquifer injection. Thirty-four OCs were regarded as having no risks while the remaining 117 OCs were divided into three groups: high, moderate and low priority OCs. Regardless of the recharge way, nonylphenol, erythromycin and ibuprofen were the highest priority OCs; their removal should be prioritized. Also the database should be updated as detecting technology is developed. PMID:24960229

  7. Natural recharge and localization of fresh ground water in Kuwait

    USGS Publications Warehouse

    Bergstrom, R.E.; Aten, R.E.

    1965-01-01

    Fresh ground water (200 parts per million total dissolved solids and upwards) occurs in portions of Pleistocene sandstone aquifers beneath basins and wadis in north Kuwait where the mean rainfall is about five inches per year. The fresh water is surrounded and underlain by brackish water (> 4000 ppm TDS). Drilling and testing show that fresh water saturation is restricted to wadis and basin areas; in Rawdatain basin it attains a maximum thickness of about 110 feet and a lateral extent of about seven miles. The fresh ground water represents recharge localized, during infrequent, torrential rain storms, in areas of concentrated runoff where sediments in the vadose zone are moderately permeable and depth to the water table is generally less than a hundred feet. Concentration of runoff appears to be the primary control in the localization of recharge. The fresh water percolates downward to the ground-water reservoir following rare storms, then flows in the direction of hydraulic gradient and gradually becomes brackish. Theoretical delineation of the recharge area and ground-water flow pattern in Rawdatain was confirmed by tritium and C14 dating of the water. Brackish ground-water conditions prevail from water table downward in areas where rainfall infiltrates essentially where it falls, permeability of sediments in the vadose zone is low, or the water table is several hundred feet below land surface. In these areas, rainfall is retained and lost within the soil zone or becomes mineralized during deep percolation. ?? 1964.

  8. Modelling the groundwater recharge of an urban area in Germany

    NASA Astrophysics Data System (ADS)

    Tesch, Sabine; Dunger, Volkmar; Matschullat, Jörg

    2010-05-01

    Groundwater recharge is an important part of the natural water cycle. This cycle is disturbed particularly in urban areas. Sealing negatively influences the hydrological and mechanical soil properties. The continued sealing of soils, mainly caused by urbanisation, will continue to reduce the infiltration of water to groundwater and increase the surface run-off. Furthermore, recent and future climate changes strongly affect the available water resources. Those changes in water availability interfere with i.e., the cultivation of land, forest management, water supply, waste water disposal and urban infrastructure. Those issues are studied in the BMBF-supported joint research project REGKLAM that deals with climate change adaptation options in the model region Dresden. This work aims at simulating the groundwater recharge for the status quo and regionalised climate change scenarios and thus will deliver a central component to other parts of the REGKLAM project. Modelling is done using the two-dimensional hydrological model BOWAM. Current groundwater recharge models miss not only a high resolution, but also a realistic description of soil properties. Thus, it was necessary to develop a differentiated classification of soil and land use data. At present, we focus on the Quaternary aquifer of the region of Dresden, as there have been already conducted several studies that may serve as a reference for our more detailed and actual results.

  9. Wastewater reclamation and recharge: A water management strategy for Albuquerque

    SciTech Connect

    Gorder, P.J.; Brunswick, R.J.; Bockemeier, S.W.

    1995-12-31

    Approximately 61,000 acre-feet of the pumped water is annually discharged to the Rio Grande as treated wastewater. Albuquerque`s Southside Water Reclamation Plant (SWRP) is the primary wastewater treatment facility for most of the Albuquerque area. Its current design capacity is 76 million gallons per day (mgd), which is expected to be adequate until about 2004. A master plan currently is being prepared (discussed here in Wastewater Master Planning and the Zero Discharge Concept section) to provide guidelines for future expansions of the plant and wastewater infrastructure. Construction documents presently are being prepared to add ammonia and nitrogen removal capability to the plant, as required by its new discharge permit. The paper discusses water management strategies, indirect potable reuse for Albuquerque, water quality considerations for indirect potable reuse, treatment for potable reuse, geohydrological aspects of a recharge program, layout and estimated costs for a conceptual reclamation and recharge system, and work to be accomplished under phase 2 of the reclamation and recharge program.

  10. Investigation of recharge dynamics and flow paths in a fractured crystalline aquifer in semi-arid India using borehole logs: implications for managed aquifer recharge

    NASA Astrophysics Data System (ADS)

    Alazard, M.; Boisson, A.; Maréchal, J.-C.; Perrin, J.; Dewandel, B.; Schwarz, T.; Pettenati, M.; Picot-Colbeaux, G.; Kloppman, W.; Ahmed, S.

    2015-10-01

    The recharge flow paths in a typical weathered hard-rock aquifer in a semi-arid area of southern India were investigated in relation to structures associated with a managed aquifer recharge (MAR) scheme. Despite the large number of MAR structures, the mechanisms of recharge in their vicinity are still unclear. The study uses a percolation tank as a tool to identify the input signal of the recharge and uses multiple measurements (piezometric time series, electrical conductivity profiles in boreholes) compared against heat-pulse flowmeter measurements and geochemical data (major ions and stable isotopes) to examine recharge flow paths. The recharge process is a combination of diffuse piston flow and preferential flow paths. Direct vertical percolation appears to be very limited, in contradiction to the conceptual model generally admitted where vertical flow through saprolite is considered as the main recharge process. The horizontal component of the flow leads to a strong geochemical stratification of the water column. The complex recharge pattern, presented in a conceptual model, leads to varied impacts on groundwater quality and availability in both time and space, inducing strong implications for water management, water quality evolution, MAR monitoring and longer-term socio-economic costs.

  11. Investigation of recharge dynamics and flow paths in a fractured crystalline aquifer in semi-arid India using borehole logs: implications for managed aquifer recharge

    NASA Astrophysics Data System (ADS)

    Alazard, M.; Boisson, A.; Maréchal, J.-C.; Perrin, J.; Dewandel, B.; Schwarz, T.; Pettenati, M.; Picot-Colbeaux, G.; Kloppman, W.; Ahmed, S.

    2016-02-01

    The recharge flow paths in a typical weathered hard-rock aquifer in a semi-arid area of southern India were investigated in relation to structures associated with a managed aquifer recharge (MAR) scheme. Despite the large number of MAR structures, the mechanisms of recharge in their vicinity are still unclear. The study uses a percolation tank as a tool to identify the input signal of the recharge and uses multiple measurements (piezometric time series, electrical conductivity profiles in boreholes) compared against heat-pulse flowmeter measurements and geochemical data (major ions and stable isotopes) to examine recharge flow paths. The recharge process is a combination of diffuse piston flow and preferential flow paths. Direct vertical percolation appears to be very limited, in contradiction to the conceptual model generally admitted where vertical flow through saprolite is considered as the main recharge process. The horizontal component of the flow leads to a strong geochemical stratification of the water column. The complex recharge pattern, presented in a conceptual model, leads to varied impacts on groundwater quality and availability in both time and space, inducing strong implications for water management, water quality evolution, MAR monitoring and longer-term socio-economic costs.

  12. Evaluating storm-scale groundwater recharge dynamics with coupled weather radar data and unsaturated zone modeling

    NASA Astrophysics Data System (ADS)

    Nasta, P.; Gates, J. B.; Lock, N.; Houston, A. L.

    2013-12-01

    Groundwater recharge rates through the unsaturated zone emerge from complex interactions within the soil-vegetation-atmosphere system that derive from nonlinear relationships amongst atmospheric boundary conditions, plant water use and soil hydraulic properties. While it is widely recognized that hydrologic models must capture soil water dynamics in order to provide reliable recharge estimates, information on episodic recharge generation remains uncommon, and links between storm-scale weather patterns and their influence on recharge is largely unexplored. In this study, the water balance of a heterogeneous one-dimensional soil domain (3 m deep) beneath a typical rainfed corn agro-ecosystem in eastern Nebraska was numerically simulated in HYDRUS-1D for 12 years (2001-2012) on hourly time steps in order to assess the relationships between weather events and episodic recharge generation. WSR-88D weather radar reflectivity data provided both rainfall forcing data (after estimating rain rates using the z/r ratio method) and a means of storm classification on a scale from convective to stratiform using storm boundary characteristics. Individual storm event importance to cumulative recharge generation was assessed through iterative scenario modeling (773 total simulations). Annual cumulative recharge had a mean value of 9.19 cm/yr (about 12 % of cumulative rainfall) with coefficient of variation of 73%. Simulated recharge generation events occurred only in late winter and spring, with a peak in May (about 35% of total annual recharge). Recharge generation is observed primarily in late spring and early summer because of the combination of high residual soil moisture following a winter replenishment period, heavy convective storms, and low to moderate potential evapotranspiration rates. During the growing season, high rates of root water uptake cause rapid soil water depletion, and the concurrent high potential evapotranspiration and low soil moisture prevented recharge generation until late winter, even when intense convective storms took place. For this reason, about 86% of all precipitation events produce insignificant recharge contributions. Recharge responses to individual storms were nonlinear and did not cluster well with either storm amount or storm classification type. For example, ~7% of rainfall events fall near the 1:1 rainfall/recharge line and these events represent about 37% of cumulative recharge, and individual storms accounted for up to 4% of their annual totals. However, recharge events in late winter are mainly triggered by stratiform precipitation whereas in spring they are generally generated by convective storms. This novel approach to assessing storm-scale recharge may be relevant to several current challenges in the characterization of groundwater recharge processes, including the evaluation of their spatiotemporal distributions and the impacts of climate change on groundwater.

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

    PubMed

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

    2009-01-01

    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

  14. Overview of Ground-Water Recharge Study Sites

    USGS Publications Warehouse

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

    2007-01-01

    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.

  15. Implications of projected climate change for groundwater recharge in the western United States

    NASA Astrophysics Data System (ADS)

    Meixner, Thomas; Manning, Andrew H.; Stonestrom, David A.; Allen, Diana M.; Ajami, Hoori; Blasch, Kyle W.; Brookfield, Andrea E.; Castro, Christopher L.; Clark, Jordan F.; Gochis, David J.; Flint, Alan L.; Neff, Kirstin L.; Niraula, Rewati; Rodell, Matthew; Scanlon, Bridget R.; Singha, Kamini; Walvoord, Michelle A.

    2016-03-01

    Existing studies on the impacts of climate change on groundwater recharge are either global or basin/location-specific. The global studies lack the specificity to inform decision making, while the local studies do little to clarify potential changes over large regions (major river basins, states, or groups of states), a scale often important in the development of water policy. An analysis of the potential impact of climate change on groundwater recharge across the western United States (west of 100° longitude) is presented synthesizing existing studies and applying current knowledge of recharge processes and amounts. Eight representative aquifers located across the region were evaluated. For each aquifer published recharge budget components were converted into four standard recharge mechanisms: diffuse, focused, irrigation, and mountain-systems recharge. Future changes in individual recharge mechanisms and total recharge were then estimated for each aquifer. Model-based studies of projected climate-change effects on recharge were available and utilized for half of the aquifers. For the remainder, forecasted changes in temperature and precipitation were logically propagated through each recharge mechanism producing qualitative estimates of direction of changes in recharge only (not magnitude). Several key patterns emerge from the analysis. First, the available estimates indicate average declines of 10-20% in total recharge across the southern aquifers, but with a wide range of uncertainty that includes no change. Second, the northern set of aquifers will likely incur little change to slight increases in total recharge. Third, mountain system recharge is expected to decline across much of the region due to decreased snowpack, with that impact lessening with higher elevation and latitude. Factors contributing the greatest uncertainty in the estimates include: (1) limited studies quantitatively coupling climate projections to recharge estimation methods using detailed, process-based numerical models; (2) a generally poor understanding of hydrologic flowpaths and processes in mountain systems; (3) difficulty predicting the response of focused recharge to potential changes in the frequency and intensity of extreme precipitation events; and (4) unconstrained feedbacks between climate, irrigation practices, and recharge in highly developed aquifer systems.

  16. The ophiolite of the Eohellenic nappe in the island of Skyros, Greece: Geotectonic environment of formation and metamorphic conditions inferred by mineralogical and geochemical data

    NASA Astrophysics Data System (ADS)

    Karkalis, Christos; Magganas, Andreas; Koutsovitis, Petros

    2014-05-01

    The island of Skyros is located in the Sporades-Aegean region. It includes an ophiolitic mélange sequence consisting of serpentinites, gabbroic and doleritic rocks, and also lavas which mostly appear in massive form, but in rare cases as deformed pillows. The ophiolitic mélange sequence also includes rodingites, ophicalcites, as well as radiolarites. This formation belongs to the Eohellenic tectonic nappe, which encompasses marbles, sandstones and schists and was emplaced onto the Pelagonian Zone during Early Cretaceous [1, 2]. Serpentinites were most likely formed after serpentinization of harzburgitic protoliths and consist of serpentine, bastite, spinel and magnetite. The chemistry of spinels (TiO2=0.14-0.25 wt.%, Al2O3=35.1-35.21 wt.%, Cr#=37.38-38.87), shows that the harzburgitic protoliths plausibly resemble back-arc basin peridotites [3]. Gabbros and dolerites present mostly subophitic textures, between the hornblende/clinopyroxene and plagioclase grains. Based upon their petrography and on their mineral chemistry hornblendes have been distinguished into magmatic and metamorphic hornblendes, with the first occurring mostly in gabbroic rocks. Magmatic hornblendes exhibit relatively high TiO2 (1.42-1.62 wt.%), Al2O3 (5.11-5.86 wt.%) and Na2O (1.01-1.09 wt.%) contents, with their presence implying that the magma was at least to some degree hydrous. Lavas are tholeiitic basalts with relatively high FeOt≡12 wt.% and low K2O and Th contents, consisting mostly albite, altered clinopyroxene and devitrified glass. Tectonomagmatic discrimination diagrams [4, 5] illustrate that the studied gabbros and lavas of Skyros are most likely associated with SSZ processes. Gabbroic rocks, subvolcanic dolerites and lavas have been subjected to greenschist/subgreenschist metamorphic processes, as confirmed by the presence of secondary amphiboles (metamorphic hornblende, actinolite/tremolite), epidote, pumpellyite and chlorite in all of the studied samples. On the other hand, the occurrence of rodingites and ophicalcites clearly point to interaction of the gabbroic rocks and serpentinites with hydrothermal fluids, which most probably took place during the stage of exhumation and tectonic emplacement. Ophicalcites contain serpentine, calcite, magnetite, as well as rare pyroxene and spinel. Rodingites on their behalf include hydroandradite (Alm0.00Adr61.33-67.43Grs28.25-35.18Prp0.10-2.49Sps0.00-0.33Uv0.41-2.75), vesuvianite (MgO=2.78-3.33 wt.%; TiO2=0.02-0.59 wt.%) diopside neoblasts (En48.53-49.89Wo47.56-48.10Fs2.32-3.33; Mg#=93.96-96.28), chlorite and also accessory prehnite. Some small-sized Cr-bearing hydrogarnet crystals (Cr2O3=10.34 wt.%) were most likely formed at the expense of spinel. The types of hydrogarnet and vesuvianite crystals are highly indicative for the involvement of subduction-related fluids during the formation of the rodingites [6]. References: [1] Jacobshagen & Wallbrecher 1984: Geol. Soc., London, Sp. Pub. 17, 591-602, [2] Pe-Piper 1991: Ofioliti, 16, 111 - 120, [3] Kamenetsky Sobolev, Joron & Semet 2001: J Petrol 42, 655-671, [4] Agrawal, Guevara & Verma 2008: Intern. Geol. Rev. 50, 1057-1079, [5] Pearce & Cann 1973: Earth Plan. Sci. Lett. 19, 290-300, [6] Koutsovitis, Magganas, Pomonis & Ntaflos 2013. Lithos 172-173, 139-157.

  17. Role of brittle deformation during the initiation of ductile HP-LT shear zone in a metarhyolite (Suretta nappe, Eastern Central Alps).

    NASA Astrophysics Data System (ADS)

    Poilvet, Jean-Charles; Goncalves, Philippe; Oliot, Emilien; Marquer, Didier

    2014-05-01

    Although ductile shear zones are common deformation structures in the middle to deep continental lithosphere, the initiation of such structures among homogeneous and isotropic protolith (e.g. granitoid bodies) is still a matter of debate. Indeed, the lack of consensus concerns the presence and the nature of a preexisting heterogeneity (structural or compositional, such as dykes, joints or cracks). This is mainly due to the lack of observation of preserved precursors, which, if they were present initially, are generally obliterated by subsequent intense deformation. Different conceptual models require a structural precursor, which enables fluids to flow and promotes metamorphic and metasomatic reactions via fluid-rock interactions. Those fluid-rock interactions are commonly presented as a key factor controlling strain localization or lateral propagation. The main goal of this contribution is to present the first observations, to our knowledge, of a preserved brittle precursor of a millimeter scale shear zone under blueschist facies metamorphic conditions. This work provides new evidences into how ductile shear zones occurring within homogeneous and isotropic protolith nucleate and develop. The present study exposes shear zones from the Roffna metarhyolite, a subvolcanic intrusion representing most of the northern part of the Suretta nappe (Penninic domain, Eastern Central Alps). This early Permian massif intruded an older basement and was affected only by Tertiary Alpine tectonics. The heterogeneous strain pattern consists, at all scales of anastomosing shear zones surrounding lenses of nearly undeformed rocks The investigated outcrop is characterized by the presence of a shear zone network from millimetric to plurimetric scale developed under blueschist facies conditions related to continental subduction of the European plate. A combined study including field observations, EBSD analysis, SEM-CL and conventional imaging together with thermodynamic modeling of phase relations allow us to decipher the interplay between brittle and ductile deformation at the onset of shear zone development. At First, the field study shows that the strain pattern defined by millimeter to centimeter wide brittle precusors is identical with the strain pattern defined by plurimeter scale mature shear zones. This suggests that the initiation of the shear zone, via brittle deformation occurs in the same strain field as the development and widening of the shear zone under ductile conditions. Microtextural observations also clearly indicate a brittle component during the shear zone formation. An analysis of the chemical composition of white mica, biotite and epidote, which crystallize within the precursor, confirms that the crystallization of these phases has taken place under blueschist facies metamorphic conditions (T ≡ 450°C and P ≡ 10 kbar) although deformation was brittle. Moreover, high resolution X-ray mapping of the precursor shows that the rock in the vicinity of the precursor has undergone mass transfer, suggesting that fluid-rock interactions occurred during the first stage of the shear zone initiation and are not restricted only to the stage of shear zone widening. Our observations confirm that ductile shear zones in the Roffna metarhyolite developed from a non-inherited brittle precursor involving a brittle-to-ductile behavior evolution under blueschist metamorphic facies conditions.

  18. The Continent-Ocean Transition in the Mid-Norwegian Margin: Insight From Seismic Data and the Onshore Caledonian Analogue in the Seve Nappe Complex

    NASA Astrophysics Data System (ADS)

    Abdelmalak, Mansour M.; Planke, Sverre; Andersen, Torgeir B.; Faleide, Jan Inge; Corfu, Fernando; Tegner, Christian; Myklebust, Reidun

    2015-04-01

    The continental breakup and initial seafloor spreading in the NE Atlantic was accompanied by widespread intrusive and extrusive magmatism and the formation of conjugate volcanic passive margins. These margins are characterized by the presence of seaward dipping reflectors (SDR), an intense network of mafic sheet intrusions of the continental crust and adjacent sedimentary basins and a high-velocity lower crustal body. Nevertheless many issues remain unclear regarding the structure of volcanic passive margins; in particular the transitional crust located beneath the SDR.New and reprocessed seismic reflection data on the Mid-Norwegian margin allow a better sub-basalt imaging of the transitional crust located beneath the SDR. Different high-amplitude reflections with abrupt termination and saucer shaped geometries are identified and interpreted as sill intrusions. Other near vertical and inclined reflections are interpreted as dykes or dyke swarms. We have mapped the extent of the dyke reflections along the volcanic margin. The mapping suggests that the dykes represent the main feeder system for the SDR. The identification of saucer shaped sills implies the presence of sediments in the transitional zone beneath the volcanic sequences. Onshore exposures of Precambrian basement of the eroded volcanic margin in East Greenland show that, locally, the transitional crust is highly intruded by dykes and intrusive complexes with an increasing intensity of the plumbing and dilatation of the continental crust ocean-ward. Another well exposed analogue for a continent-ocean transitional crust is located within the Seve Nappe Complex (SNC) of the Scandinavian Caledonides. The best-preserved parts of SNC in the PÃ¥rte, Sarek, Kebnekaise, Abisko, and Indre Troms mountains are composed mainly of meta-sandstones and shales (now hornfelses) truncated typically by mafic dykes. At Sarek and PÃ¥rte, the dykes intrude the sedimentary rocks of the Favoritkammen Group, with a dyke density up to 70-80%. This complex was photographed in a regional helicopter survey and sampled for the study of the different dyke generations, their geochemistry and ages in 2014. Extending for at least 800 km within the SNC, the mafic igneous rocks most probably belonged to a volcanic system with the size of a large igneous province (LIP). This volcanic margin is suggested to have formed along the Caledonian margin of Baltica or within hyperextended continental slivers outboard of Baltica during the breakup of Rodinia. The intensity of the pre-Caledonian LIP-magmatism is comparable to that of the NE Atlantic volcanic margins. The SNC-LIP is considered to represent a potential onshore analogue to the deeper level of the Mid-Norwegian margin transitional crust, and permits direct observation, sampling and better understanding of deeper levels of magma-rich margins.

  19. Ground-water recharge through active sand dunes in northwestern Nevada

    USGS Publications Warehouse

    Berger, D.L.

    1992-01-01

    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.

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

    SciTech Connect

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

    2009-09-28

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

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

  2. Multi-component transport and transformation in deep confined aquifer during groundwater artificial recharge.

    PubMed

    Zhang, Wenjing; Huan, Ying; Yu, Xipeng; Liu, Dan; Zhou, Jingjing

    2015-04-01

    Taking an artificial groundwater recharge site in Shanghai, China as an example, this study employed a combination of laboratory experiment and numerical modeling to investigate the transport and transformation of major solutes, as well as the mechanism of associated water-rock interactions in groundwater during artificial groundwater recharge. The results revealed that: (1) Major ions in groundwater were mainly affected by mixing, ion exchanging (Ca(2+), Mg(2+), Na(+), K(+)), as well as dissolution of Calcite, Dolomite. Dissolution of carbonate minerals was not entirely dependent on the pattern of groundwater recharge, the reactivity of the source water itself as indicated by the sub-saturation with respect to the carbonate minerals is the primary factor. (2) Elemental dissolution of As, Cr and Fe occurred in aquifer was due to the transformation of subsurface environment from anaerobic to aerobic systems. Different to bank filtration recharge or pond recharge, the concentration of Fe near the recharge point was mainly controlled by oxidation dissolution of Siderite, which was followed by a release of As, Cr into groundwater. (3) Field modeling results revealed that the hydro chemical type of groundwater gradually changed from the initial Cl-HCO3-Na type to the Cl-HCO3-Na-Ca type during the recharge process, and its impact radius would reach roughly 800 m in one year. It indicated that the recharge pressure (approx. 0.45 Mpa) would enlarge the impact radius under deep well recharge conditions. According to different recharge modes, longer groundwater resident time will associate with minerals' fully reactions. Although the concentrations of major ions were changing during the artificial recharge process, it did not pose a negative impact on the environmental quality of groundwater. The result of trace elements indicated that controlling the environment factors (especially Eh, DO, flow rate) during the recharge was effective to reduce the potential threats to groundwater quality. PMID:25617875

  3. Grundlagen des Tissue Engineering

    NASA Astrophysics Data System (ADS)

    Mayer, Jörg; Blum, Janaki; Wintermantel, Erich

    Die Organtransplantation stellt eine verbreitete Therapie dar, um bei krankheitsoder unfallbedingter Schädigung eines Organs die Gesamtheit seiner Funktionen wieder herzustellen, indem es durch ein Spenderorgan ersetzt wird. Organtransplantationen werden für die Leber, die Niere, die Lunge, das Herz oder bei schweren grossflächigen Verbrennungen der Haut vorgenommen. Der grosse apparative, personelle und logistische Aufwand und die Risiken der Transplantationschirurgie (Abstossungsreaktionen) sowie die mangelnde Verfügbarkeit von immunologisch kompatiblen Spenderorganen führen jedoch dazu, dass der Bedarf an Organtransplantaten nur zu einem sehr geringen Teil gedeckt werden kann. Sind Spenderorgane nicht verfügbar, können in einzelnen Fällen lebenswichtige Teilfunktionen, wie beispielsweise die Filtrationsfunktion der Niere durch die Blutreinigung mittels Dialyse ersetzt oder, bei mangelnder Funktion der Bauchspeicheldrüse (Diabetes), durch die Verabreichung von Insulin ein normaler Zustand des Gesamtorganismus auch über Jahre hinweg erhalten werden. Bei der notwendigen lebenslangen Anwendung apparativer oder medikamentöser Therapie können für den Patienten jedoch häufig schwerwiegende, möglicherweise lebensverkürzende Nebenwirkungen entstehen. Daher werden in der Forschung Alternativen gesucht, um die Funktionen des ausgefallenen Organs durch die Implantation von Zellen oder in vitro gezüchteten Geweben möglichst umfassend wieder herzustellen. Dies erfordert biologisch aktive Implantate, welche die für den Stoffwechsel des Organs wichtigen Zellen enthalten und einen organtypischen Stoffwechsel entfalten.

  4. Sur l'origine par altération du substratum schisteux de la minéralisation chlorurée des eaux d'une nappe côtière sous climat semi-aride (Chtouka-Massa, Maroc)

    NASA Astrophysics Data System (ADS)

    Krimissa, Samira; Michelot, Jean-Luc; Bouchaou, Lhoussaine; Mudry, Jacques; Hsissou, Youssef

    2004-11-01

    The origin of chloride ions in groundwater from the Chtouka-Massa plain (Morocco) was studied by using chemical and isotopic analyses of water, and petrographic and chemical analyses of rocks. It appears that the schist formation, which forms the basement of the studied aquifer, is the main source of the high Cl - concentrations in groundwater. In these schists, chloride is, for a part, probably contained in biotites, and is released into groundwater through the weathering of these minerals. However, the exceptionally high chloride contents of these schists are difficult to explain if one does not assume that they also contain evaporitic-type minerals. To cite this article: S. Krimissa et al., C. R. Geoscience 336 (2004).

  5. Using noble gas tracers to constrain a groundwater flow model with recharge elevations: A novel approach for mountainous terrain

    NASA Astrophysics Data System (ADS)

    Doyle, Jessica M.; Gleeson, Tom; Manning, Andrew H.; Mayer, K. Ulrich

    2015-10-01

    Environmental tracers provide information on groundwater age, recharge conditions, and flow processes which can be helpful for evaluating groundwater sustainability and vulnerability. Dissolved noble gas data have proven particularly useful in mountainous terrain because they can be used to determine recharge elevation. However, tracer-derived recharge elevations have not been utilized as calibration targets for numerical groundwater flow models. Herein, we constrain and calibrate a regional groundwater flow model with noble-gas-derived recharge elevations for the first time. Tritium and noble gas tracer results improved the site conceptual model by identifying a previously uncertain contribution of mountain block recharge from the Coast Mountains to an alluvial coastal aquifer in humid southwestern British Columbia. The revised conceptual model was integrated into a three-dimensional numerical groundwater flow model and calibrated to hydraulic head data in addition to recharge elevations estimated from noble gas recharge temperatures. Recharge elevations proved to be imperative for constraining hydraulic conductivity, recharge location, and bedrock geometry, and thus minimizing model nonuniqueness. Results indicate that 45% of recharge to the aquifer is mountain block recharge. A similar match between measured and modeled heads was achieved in a second numerical model that excludes the mountain block (no mountain block recharge), demonstrating that hydraulic head data alone are incapable of quantifying mountain block recharge. This result has significant implications for understanding and managing source water protection in recharge areas, potential effects of climate change, the overall water budget, and ultimately ensuring groundwater sustainability.

  6. Using noble gas tracers to constrain a groundwater flow model with recharge elevations: A novel approach for mountainous terrain

    USGS Publications Warehouse

    Doyle, Jessica M.; Gleeson, Tom; Manning, Andrew H.; Mayer, K. Ulrich

    2015-01-01

    Environmental tracers provide information on groundwater age, recharge conditions, and flow processes which can be helpful for evaluating groundwater sustainability and vulnerability. Dissolved noble gas data have proven particularly useful in mountainous terrain because they can be used to determine recharge elevation. However, tracer-derived recharge elevations have not been utilized as calibration targets for numerical groundwater flow models. Herein, we constrain and calibrate a regional groundwater flow model with noble-gas-derived recharge elevations for the first time. Tritium and noble gas tracer results improved the site conceptual model by identifying a previously uncertain contribution of mountain block recharge from the Coast Mountains to an alluvial coastal aquifer in humid southwestern British Columbia. The revised conceptual model was integrated into a three-dimensional numerical groundwater flow model and calibrated to hydraulic head data in addition to recharge elevations estimated from noble gas recharge temperatures. Recharge elevations proved to be imperative for constraining hydraulic conductivity, recharge location, and bedrock geometry, and thus minimizing model nonuniqueness. Results indicate that 45% of recharge to the aquifer is mountain block recharge. A similar match between measured and modeled heads was achieved in a second numerical model that excludes the mountain block (no mountain block recharge), demonstrating that hydraulic head data alone are incapable of quantifying mountain block recharge. This result has significant implications for understanding and managing source water protection in recharge areas, potential effects of climate change, the overall water budget, and ultimately ensuring groundwater sustainability.

  7. Modeling spatiotemporal impacts of hydroclimatic extremes on groundwater recharge at a Mediterranean karst aquifer

    NASA Astrophysics Data System (ADS)

    Hartmann, Andreas; Mudarra, Matías; Andreo, Bartolomé; Marín, Ana; Wagener, Thorsten; Lange, Jens

    2014-08-01

    Karst aquifers provide large parts of the water supply for Mediterranean countries, though climate change is expected to have a significant negative impact on water availability. Recharge is therefore a key variable that has to be known for sustainable groundwater use. In this study, we present a new approach that combines two independent methods for karst recharge estimation. The first method derives spatially distributed information of mean annual recharge patterns through GIS analysis. The second is a process-based karst model that provides spatially lumped but temporally distributed information about recharge. By combining both methods, we add a spatial reference to the lumped simulations of the process-based model. In this way, we are able to provide spatiotemporal information of recharge and subsurface flow dynamics also during varying hydroclimatic conditions. We find that there is a nonlinear relationship between precipitation and recharge rates resulting in strong decreases of recharge following even moderate decreases of precipitation. This is primarily due to almost constant actual evapotranspiration amounts despite varying hydroclimatic conditions. During the driest year in the record, almost the entire precipitation was consumed as actual evapotranspiration and only little diffuse recharge took place at the high altitudes of our study site. During wettest year, recharge constituted a much larger fraction of precipitation and occurred at the entire study site. Our new method and our findings are significant for decision makers in similar regions that want to prepare for possible changes of hydroclimatic conditions in the future.

  8. Seasonality of groundwater recharge in the Basin and Range Province, western North America

    NASA Astrophysics Data System (ADS)

    Neff, Kirstin Lynn

    Alluvial groundwater systems are an important source of water for communities and biodiverse riparian corridors throughout the arid and semi-arid Basin and Range Geological Province of western North America. These aquifers and their attendant desert streams have been depleted to support a growing population, while projected climate change could lead to more extreme episodes of drought and precipitation in the future. The only source of replenishment to these aquifers is recharge. This dissertation builds upon previous work to characterize and quantify recharge in arid and semi-arid basins by characterizing the intra-annual seasonality of recharge across the Basin and Range Province, and considering how climate change might impact recharge seasonality and volume, as well as fragile riparian corridors that depend on these hydrologic processes. First, the seasonality of recharge in a basin in the sparsely-studied southern extent of the Basin and Range Province is determined using stable water isotopes of seasonal precipitation and groundwater, and geochemical signatures of groundwater and surface water. In northwestern Mexico in the southern reaches of the Basin and Range, recharge is dominated by winter precipitation (69% +/- 42%) and occurs primarily in the uplands. Second, isotopically-based estimates of seasonal recharge fractions in basins across the region are compared to identify patterns in recharge seasonality, and used to evaluate a simple water budget-based model for estimating recharge seasonality, the normalized seasonal wetness index (NSWI). Winter precipitation makes up the majority of annual recharge throughout the region, and North American Monsoon (NAM) precipitation has a disproportionately weak impact on recharge. The NSWI does well in estimating recharge seasonality for basins in the northern Basin and Range, but less so in basins that experience NAM precipitation. Third, the seasonal variation in riparian and non-riparian vegetation greenness, represented by the normalized difference vegetation index (NDVI), is characterized in several of the study basins and climatic and hydrologic controls are identified. Temperature was the most significant driver of vegetation greenness, but precipitation and recharge seasonality played a significant role in some basins at some elevations. Major contributions of this work include a better understanding of recharge in a monsoon-dominated basin, the characterization of recharge seasonality at a regional scale, evaluation of an estimation method for recharge seasonality, and an interpretation of the interaction of seasonal hydrologic processes, vegetation dynamics, and climate change.

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

    USGS Publications Warehouse

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

    2005-01-01

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

  10. SWB-A modified Thornthwaite-Mather Soil-Water-Balance code for estimating groundwater recharge

    USGS Publications Warehouse

    Westenbroek, S.M.; Kelson, V.A.; Dripps, W.R.; Hunt, R.J.; Bradbury, K.R.

    2010-01-01

    A Soil-Water-Balance (SWB) computer code has been developed to calculate spatial and temporal variations in groundwater recharge. The SWB model calculates recharge by use of commonly available geographic information system (GIS) data layers in combination with tabular climatological data. The code is based on a modified Thornthwaite-Mather soil-water-balance approach, with components of the soil-water balance calculated at a daily timestep. Recharge calculations are made on a rectangular grid of computational elements that may be easily imported into a regional groundwater-flow model. Recharge estimates calculated by the code may be output as daily, monthly, or annual values.

  11. Groundwater recharge at five representative sites in the Hebei Plain, China.

    PubMed

    Lu, Xiaohui; Jin, Menggui; van Genuchten, Martinus Th; Wang, Bingguo

    2011-01-01

    Accurate estimates of groundwater recharge are essential for effective management of groundwater, especially when supplies are limited such as in many arid and semiarid areas. In the Hebei Plain, China, water shortage is increasingly restricting socioeconomic development, especially for agriculture, which heavily relies on groundwater. Human activities have greatly changed groundwater recharge there during the past several decades. To obtain better estimates of recharge in the plain, five representative sites were selected to investigate the effects of irrigation and water table depth on groundwater recharge. At each site, a one-dimensional unsaturated flow model (Hydrus-1D) was calibrated using field data of climate, soil moisture, and groundwater levels. A sensitivity analysis of evapotranspirative fluxes and various soil hydraulic parameters confirmed that fine-textured surface soils generally generate less recharge. Model calculations showed that recharge on average is about 175 mm/year in the piedmont plain to the west, and 133 mm/year in both the central alluvial and lacustrine plains and the coastal plain to the east. Temporal and spatial variations in the recharge processes were significant in response to rainfall and irrigation. Peak time-lags between infiltration (rainfall plus irrigation) and recharge were 18 to 35 days in the piedmont plain and 3 to 5 days in the central alluvial and lacustrine plains, but only 1 or 2 days in the coastal plain. This implies that different time-lags corresponding to different water table depths must be considered when estimating or modeling groundwater recharge. PMID:20100294

  12. Recharge in Karst Shrublands of Central Texas: Monitoring Drip Rates in Shallow Caves

    NASA Astrophysics Data System (ADS)

    Bazan, R. A.; Wilcox, B. P.; Munster, C. L.; Owens, K.; Shade, B.

    2007-12-01

    The exceedingly complex subsurface hydrology of karst landscapes presents formidable challenges to understanding recharge rates and the relationships between rainfall and recharge. In this study, we have established a network of drip collectors and monitoring stations in shallow caves in the Edwards Plateau to better understand the dynamics of recharge and eventually for determining the effect of woody plants on recharge rates. Understanding recharge rates has direct relevance for management of the Edwards Aquifer, which serves as the main source of fresh water for the city of San Antonio and surrounding communities, As population around San Antonio continues to grow so does the demand for water, in turn, a need to address the supply exists. We have instrumented two caves that lie within the Camp Bullis Training Facility north of San Antonio, Texas. Data collected at each site record precipitation on the surface and measure recharge inside the caves. Monitoring of natural rainfall events at these sites began in October 2004. To date, all monitoring and data collection has occurred with the juniper canopy in place. Results have shown that cave recharge is influenced by 1) rainfall intensity and duration, 2) antecedent soil moisture condition, 3) depth of soil, and 4) surface geology. We plan to remove the tree canopy in the summer of 2008 and continue monitoring cave recharge in response to natural and re-created rainfall events. Comparing data collected with and without juniper cover in place will allow us to determine if recharge may be increased by reducing tree cover.

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

    PubMed

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

    2012-01-01

    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

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

    SciTech Connect

    Savard, C.S.

    1998-10-01

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

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

    USGS Publications Warehouse

    Holtschlag, David J.

    1997-01-01

    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.

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

    USGS Publications Warehouse

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

    1979-01-01

    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.

  17. Artificial recharge through a thick, heterogeneous unsaturated zone.

    PubMed

    Izbicki, John A; Flint, Alan L; Stamos, Christina L

    2008-01-01

    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 x 10(6) m(3) 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 x 10(6) m(3) 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. PMID:18194322

  18. Representative recharge rates in a complex unsaturated hydrogeology

    SciTech Connect

    Vold, E.; Newman, B.; Birdsell, K.

    1997-02-01

    This study summarizes analyses used for the determination of representative recharge rates in a semi-arid terrain of complex topography for the purpose of modeling the performance assessment of a mesa top disposal facility. Four recharge rates are identified based on different terrains. The terrain is first broadly grouped into canyon bottoms and mesa tops, with each covering about half the topography. The canyon bottoms are considered wet or dry depending on the local infiltration conditions and the influence of mans` activities. The mesa tops are separated into locations which are undisturbed and disturbed by laboratory operations. Disturbed locations at the disposal facility include the disposal pits utilized for shallow land burial of low-level radioactive waste, covering approximately half the mesa top area. Several sources of data and analyses have been synthesized to estimate the resulting recharge rates. Data and analyses include: (1) detailed surface water balance calculations with site-specific parameter values as input; (2) chloride ion profiles and analysis of implied flux at several borehole locations; (3) analyses of liquid and vapor phase vertical flux from moisture profiles with stratigraphic unit averaged unsaturated hydrologic properties; (4) comparison of moisture content field data with values implied from Darcy flux calculations for assumed unit gradient conditions and for stratigraphic unit averaged unsaturated hydrologic properties; (5) liquid flux calculated under self-consistent gradients from field observed moisture profiles and analytic determinations of in-situ moisture potential and conductivity at limited locations; (6) distributions in near surface soil moisture contents expressed as an equivalent vertical flux under unit gradient assumptions; and (7) limited comparisons to tracers available from past disposal operations.

  19. Artificial recharge through a thick, heterogeneous unsaturated zone

    USGS Publications Warehouse

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

    2008-01-01

    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.

  20. A sealed rechargeable metal-oxygen battery for traction purposes

    NASA Astrophysics Data System (ADS)

    Bursell, M.

    A prototype of a sealed, rechargeable iron-oxygen battery that is based on a new oxygen electrode design is described, noting that the electrode design has made it possible to considerably simplify construction. It is pointed out that the oxygen electrode can be described as a self-breathing oxygen pocket electrode. It reaches 2 cm above the electrolyte in the battery and is fed with oxygen at the top of the battery by virtue of the pressure difference between the top of the electrode and the bottom.

  1. A 65 Ah rechargeable lithium molybdenum disulfide battery

    NASA Technical Reports Server (NTRS)

    Brandt, K.

    1986-01-01

    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.

  2. Rechargeable thin film battery and method for making the same

    DOEpatents

    Goldner, Ronald B.; Liu, Te-Yang; Goldner, Mark A.; Gerouki, Alexandra; Haas, Terry E.

    2006-01-03

    A rechargeable, stackable, thin film, solid-state lithium electrochemical cell, thin film lithium battery and method for making the same is disclosed. The cell and battery provide for a variety configurations, voltage and current capacities. An innovative low temperature ion beam assisted deposition method for fabricating thin film, solid-state anodes, cathodes and electrolytes is disclosed wherein a source of energetic ions and evaporants combine to form thin film cell components having preferred crystallinity, structure and orientation. The disclosed batteries are particularly useful as power sources for portable electronic devices and electric vehicle applications where high energy density, high reversible charge capacity, high discharge current and long battery lifetimes are required.

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

    NASA Technical Reports Server (NTRS)

    Cohn, E. M. (inventor)

    1976-01-01

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

  4. Analyse des intensités et filtrage des énergies en émission électronique

    NASA Astrophysics Data System (ADS)

    Duval, P.; Blaise, G.; Henry, L.

    1991-10-01

    A different method for using a dispersive system consisting of a magnetic prism and an electrostatic mirror is proposed. This method allows one to study electron intensities and energies coming from the surface of a sample which has been bombarded by an electron beam of a given energy. Le système dispersif constitué d'un prisme magnétique et d'un miroir électrostatique, utilisé jusqu'à présent en microscopie électronique par transmission pour l'analyse et le filtrage des énergies des électrons transmis à travers une couche mince, peut être adapté pour constituer une nouvelle méthode d'étude des intensités et des énergies des électrons diffusés par la surface d'un échantillon bombardé par un faisceau d'électrons d'énergie choisie.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    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.

  8. Spatial variability of ground-water recharge in selected principal aquifers of the eastern United States

    NASA Astrophysics Data System (ADS)

    Nolan, B. T.

    2004-12-01

    Over 500 vadose-zone sediment cores were collected as part of a regional study of ground water recharge to aquifers comprising glacial deposits and the Floridan, Coastal Lowlands, Piedmont and Blue Ridge, and North Atlantic Coastal Plain aquifer systems. Study objectives were to compare methods for estimating recharge; to compare and contrast recharge estimates for selected principal aquifers in the eastern U.S.; and to identify landscape factors that significantly influence recharge. We evaluated the Darcian, water-budget, water table-fluctuation, and tracer methods for estimating recharge. Sediment cores were analyzed for particle size distribution, moisture content, bulk density, organic matter, and selected anions. Direct measurements of unsaturated hydraulic conductivity (K) were made on a small number of cores by the steady-state centrifuge method. For all cores, K was derived from pedotransfer functions based on texture and bulk density data. Darcian water fluxes were calculated assuming either nonuniform matric potential or a unit gradient (q about equals K). Unit gradient estimates of recharge represent homogeneous sediments and thick layers in heterogeneous systems. Preliminary results indicate that the point estimates of recharge vary considerably within principal aquifers, and that median recharge is highest in glacial deposits in the northeastern U.S. Median recharge estimated by the Darcian method was similar to estimates derived from a base-flow index. Overall, there was good correspondence between unit-gradient and non-unit-gradient estimates of recharge, indicating that matric forces were not dominant in sampled sediment layers. Unit-gradient recharge was strongly related to moisture content and sediment texture. For sands, hydraulic conductivities derived from pedotransfer functions compared favorably with those measured by the centrifuge method. The pedotransfer method, however, overpredicted K for a silty sample with high moisture content. It is possible that the pedotransfer method is biased towards sandy samples because the empirical model on which it is based is calibrated to predominantly coarse-textured soils.

  9. Ground truthing groundwater-recharge estimates derived from remotely sensed evapotranspiration: a case in South Australia

    NASA Astrophysics Data System (ADS)

    Crosbie, Russell S.; Davies, Phil; Harrington, Nikki; Lamontagne, Sebastien

    2015-03-01

    Using a water balance to estimate groundwater recharge through the use of remotely sensed evapotranspiration offers a spatial and temporal density of data that other techniques cannot match. However, the estimates are uncertain and therefore ground truthing of the recharge estimates is necessary. This study, conducted in the south-east of South Australia, demonstrated that the raw water-balance estimates of recharge had a negative bias of 45 mm/yr when compared to 190 recharge estimates using the water-table fluctuation method over a 10-year period (2001-2010). As this bias was not related to the magnitude of the recharge estimated using the water-table fluctuation method, a simple offset was used to bias-correct the water-balance recharge estimates. The bias-corrected recharge estimates had a mean residual that was not significantly different from an independent set of 99 historical recharge estimates but did have a large mean absolute residual indicating a lack of precision. The value in this technique is the density of the data (250-m grid over 29,000 km2). The relationship between the water-table depth and net recharge under different vegetation types was investigated. Under pastures, there was no relationship with water-table depth, as the shallow roots do not intercept groundwater. However, under plantation forestry, there was a relationship between net recharge and water-table depth. Net recharge under plantation forestry growing on sandy soils was independent of the water table at around 6 m depth but, under heavier textured soils, the trees were using groundwater from depths of more than 20 m.

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

    NASA Astrophysics Data System (ADS)

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

    2007-12-01

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

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

    PubMed

    Balke, Klaus-Dieter; Zhu, Yan

    2008-03-01

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

  12. Exploratory development of an electrically rechargeable lithium battery

    NASA Astrophysics Data System (ADS)

    Abraham, K. M.; Goldman, J. L.; Dempsey, M. D.; Holleck, G. L.

    1980-10-01

    The cathodic behavior or V6013 was investigated in rechargeable Li cells of the type, Li/2Me-THF,LiAsF6/V6013,C. Two forms of V6013 were synthesized and characterized. These were a stoichiometric form, i.e., V02.17, and a slightly non-stoichiometric form, i.e., V02.19. Stoichiometric V6013 was prepared by heating requisite quantities of V205 and V powder for 24 hrs. at 650 C. The slightly non-stoichiometric V6013 was prepared by the thermal decomposition of NH4V03 at 450 C. The discharge characteristics of the stoichiometric oxide at 60 C were similar to that of non-stoichiometric oxide at room temperature. The rechargeability of both the oxides were found to be sensitive to the lower voltage cutoff. The safest limits of cycling were 3.0 and 1.9V. Potentiostatic discharges of the oxides between 1.9 and 1.3V revealed a high capacity irreversible reduction process at about 1.6V. Three types of hermetically sealed cells were constructed and tested. In a high capacity (5Ah) prismatic cell utilizing the non-stoichiometric oxide, energy densities of 106 Whr/kg and 190 Whr/DM3 were achieved.

  13. Clogging in Managed Aquifer Recharge: Hydrodynamics and Geochemistry

    NASA Astrophysics Data System (ADS)

    Mays, D. C.

    2013-12-01

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

  14. Tritium tracer test to estimate aquifer recharge under irrigated conditions

    NASA Astrophysics Data System (ADS)

    Jimenez-Martinez, J.; Tamoh, K.; Candela, L.

    2009-12-01

    Environmental tracers, as tritium, have been generally used to estimate aquifer recharge under natural conditions. A tritium tracer test to estimate recharge under semi-arid and irrigated conditions is presented. The test was carried out in an experimental plot under drip irrigation, located in SE Spain, with annual row crops (rotation lettuce and melon), following common agricultural practices in open air. Tritiated water was applied as an irrigation pulse, soil cores were taken at different depths and a liquid scintillation analyzer was used to measure the concentration of tritium in soil samples. Transport of tritium was simulated with SOLVEG code, a one-dimensional numerical model for simulating transport of heat, water and tritiated water in liquid and gas phase, which has been modified and adapted for this experience, including ground cover, root growth and root water uptake. One crop has been used to calibrate the modeling approach and other three crops to validate it. Results of flow and transport modelling show a good agreement between observed and estimated tritium concentration profile. For the period October 2007-September 2008, total drainage obtained value was 441 mm.

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

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

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

    PubMed Central

    Balke, Klaus-Dieter; Zhu, Yan

    2008-01-01

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

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

    SciTech Connect

    Charles E. Russell; Tim Minor

    2002-08-31

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

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

    PubMed

    Goodenough, John B; Park, Kyu-Sung

    2013-01-30

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

  19. Biological Sulfate Reduction Rates in Hydrothermal Recharge Zones

    NASA Astrophysics Data System (ADS)

    Crowell, B.; Lowell, R. P.

    2007-12-01

    We develop a model to determine the rate of removal of seawater sulfate in the recharge regions of deep-sea hydrothermal systems as a result of biogenic sulfate reduction. The rate of sulfate reduction as a function of temperature derived from laboratory measurements on cores from the Guaymas Basin in Mexico [Jorgensen et al., 1992] is incorporated into a steady state 1-D advection-diffusion temperature equation, and a 1-D, steady- state, advection dominated conservation of solute equation. The diffusivity of sulfate in seawater is on the order of ~ 10-10 m2/s, and unless the flow speeds are < 10-12 m/s, the effects of diffusion are negligible, except within thin diffusive boundary layers. This model is then compared with a model that utilizes Gibbs free energy to quantify biogenic sulfate reduction [Bach and Edwards, 2003] in the upper oceanic crust of aging lithosphere. Using the high rates determined by Jorgensen et al. [1992], our model indicates that biological activity would reduce all seawater sulfate transported into the system within the upper 10 meters or less of the crust, which is inconsistent with the estimates of Bach and Edwards [2003]. Sulfate concentrations from ODP borehole Legs 64 and 168, at the sedimented Guaymas Basin and Juan de Fuca Ridge, respectively, show that most of the seawater sulfate is removed in the upper 100 meters. If the sulfate is assumed to all be reduced biogenically, the sulfate reduction rates at the ODP sites are at least 2 orders of magnitude less than the laboratory estimates of Jorgenson et al. [1992]. Finally, we compare the rate of seawater sulfate removal as a result of the precipitation of anhydrite, with the rate of biogenic sulfate reduction. We find that if hydrothermal recharge occurs rapidly through highly permeable faults, that biogenic sulfate reduction is negligible and that anhydrite precipitation would rapidly clog the recharge zone [Lowell and Yao, 2002]. If recharge occurs through broad zones of slow downwelling (u recharge zones at ocean ridge crests, J. Geophys. Res., 107(B9), 2183, doi:10.1029/2001JB001289.

  20. Biological Sulfate Reduction Rates in Hydrothermal Recharge Zones

    NASA Astrophysics Data System (ADS)

    Crowell, B.; Lowell, R. P.

    2004-12-01

    We develop a model to determine the rate of removal of seawater sulfate in the recharge regions of deep-sea hydrothermal systems as a result of biogenic sulfate reduction. The rate of sulfate reduction as a function of temperature derived from laboratory measurements on cores from the Guaymas Basin in Mexico [Jorgensen et al., 1992] is incorporated into a steady state 1-D advection-diffusion temperature equation, and a 1-D, steady- state, advection dominated conservation of solute equation. The diffusivity of sulfate in seawater is on the order of ~ 10-10 m2/s, and unless the flow speeds are < 10-12 m/s, the effects of diffusion are negligible, except within thin diffusive boundary layers. This model is then compared with a model that utilizes Gibbs free energy to quantify biogenic sulfate reduction [Bach and Edwards, 2003] in the upper oceanic crust of aging lithosphere. Using the high rates determined by Jorgensen et al. [1992], our model indicates that biological activity would reduce all seawater sulfate transported into the system within the upper 10 meters or less of the crust, which is inconsistent with the estimates of Bach and Edwards [2003]. Sulfate concentrations from ODP borehole Legs 64 and 168, at the sedimented Guaymas Basin and Juan de Fuca Ridge, respectively, show that most of the seawater sulfate is removed in the upper 100 meters. If the sulfate is assumed to all be reduced biogenically, the sulfate reduction rates at the ODP sites are at least 2 orders of magnitude less than the laboratory estimates of Jorgenson et al. [1992]. Finally, we compare the rate of seawater sulfate removal as a result of the precipitation of anhydrite, with the rate of biogenic sulfate reduction. We find that if hydrothermal recharge occurs rapidly through highly permeable faults, that biogenic sulfate reduction is negligible and that anhydrite precipitation would rapidly clog the recharge zone [Lowell and Yao, 2002]. If recharge occurs through broad zones of slow downwelling (u < 10-9 m/s); however, anhydrite precipitation would seal pore on the order of thousands of years even in the absence of biogenic sulfate reduction. At these slower flow speeds, the biogenic sulfate reduction may provide an important mechanism for the removal of seawater sulfate from the deeper parts of the reaction zone. Bach, W. and K.J. Edwards (2003), Iron and sulfide oxidation within the basaltic ocean crust: Implications for chemolithoautotrophic microbial biomass production, Geochim.Cosmochim. Acta, 67, 3871-3887. Jorgensen, B.B., M.F. Isaksen and H.W. Jannasch (1992), Bacterial sulfate reduction above 100 degrees C in deep-sea hydrothermal vent sediments, Science, 258, 1756-1757. Lowell, R.P. and Y. Yao (2002), Anhydrite precipitation and the extent of hydrothermal recharge zones at ocean ridge crests, J. Geophys. Res., 107(B9), 2183, doi:10.1029/2001JB001289.

  1. A ROOT ZONE MODELLING APPROACH TO ESTIMATING GROUNDWATER RECHARGE FROM IRRIGATED AREAS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In irrigated semi-arid and arid regions, accurate knowledge of groundwater recharge is important for the sustainable management of scarce water resources. The Campo de Cartagena area of southeast Spain is a semi-arid region where irrigation return flow accounts for a substantial portion of recharge....

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  3. 78 FR 6845 - Eleventh Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-31

    ... Federal Aviation Administration Eleventh Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery... Lithium Battery and Battery Systems--Small and Medium Size. SUMMARY: The FAA is issuing this notice to advise the public of the eleventh meeting of the RTCA Special Committee 225, Rechargeable Lithium...

  4. 77 FR 39321 - Eighth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-02

    ... Federal Aviation Administration Eighth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery... Lithium Battery and Battery Systems--Small and Medium Sizes. SUMMARY: The FAA is issuing this notice to advise the public of the eighth meeting of RTCA Special Committee 225, Rechargeable Lithium Battery...

  5. 78 FR 16031 - Twelfth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-13

    ... Federal Aviation Administration Twelfth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery... Lithium Battery and Battery Systems--Small and Medium Size. SUMMARY: The FAA is issuing this notice to advise the public of the twelfth meeting of the RTCA Special Committee 225, Rechargeable Lithium...

  6. 78 FR 55773 - Fourteenth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-11

    ... Federal Aviation Administration Fourteenth Meeting: RTCA Special Committee 225, Rechargeable Lithium... Lithium Battery and Battery Systems--Small and Medium Size. SUMMARY: The FAA is issuing this notice to advise the public of the fourteenth meeting of the RTCA Special Committee 225, Rechargeable...

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

    PubMed

    Szilagyi, Jozsef; Jozsa, Janos

    2013-01-01

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

  8. 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...

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

    PubMed

    Nimmo, John R; Horowitz, Charles; Mitchell, Lara

    2015-01-01

    We have developed a method to identify and quantify recharge episodes, along with their associated infiltration-related inputs, by a consistent, systematic procedure. Our algorithm partitions a time series of water levels into discrete recharge episodes and intervals of no episodic recharge. It correlates each recharge episode with a specific interval of rainfall, so storm characteristics such as intensity and duration can be associated with the amount of recharge that results. To be useful in humid climates, the algorithm evaluates the separability of events, so that those whose recharge cannot be associated with a single storm can be appropriately lumped together. Elements of this method that are subject to subjectivity in the application of hydrologic judgment are values of lag time, fluctuation tolerance, and master recession parameters. Because these are determined once for a given site, they do not contribute subjective influences affecting episode-to-episode comparisons. By centralizing the elements requiring scientific judgment, our method facilitates such comparisons by keeping the most subjective elements openly apparent, making it easy to maintain consistency. If applied to a period of data long enough to include recharge episodes with broadly diverse characteristics, the method has value for predicting how climatic alterations in the distribution of storm intensities and seasonal duration may affect recharge. PMID:24588378

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

    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.

  11. Importance of unsaturated zone flow for simulating recharge in a humid climate

    USGS Publications Warehouse

    Hunt, R.J.; Prudic, D.E.; Walker, J.F.; Anderson, M.P.

    2008-01-01

    Transient recharge to the water table is often not well understood or quantified. Two approaches for simulating transient recharge in a ground water flow model were investigated using the Trout Lake watershed in north-central Wisconsin: (1) a traditional approach of adding recharge directly to the water table and (2) routing the same volume of water through an unsaturated zone column to the water table. Areas with thin (less than 1 m) unsaturated zones showed little difference in timing of recharge between the two approaches; when water was routed through the unsaturated zone, however, less recharge was delivered to the water table and more discharge occurred to the surface because recharge direction and magnitude changed when the water table rose to the land surface. Areas with a thick (15 to 26 m) unsaturated zone were characterized by multimonth lags between infiltration and recharge, and, in some cases, wetting fronts from precipitation events during the fall overtook and mixed with infiltration from the previous spring snowmelt. Thus, in thicker unsaturated zones, the volume of water infiltrated was properly simulated using the traditional approach, but the timing was different from simulations that included unsaturated zone flow. Routing of rejected recharge and ground water discharge at land surface to surface water features also provided a better simulation of the observed flow regime in a stream at the basin outlet. These results demonstrate that consideration of flow through the unsaturated zone may be important when simulating transient ground water flow in humid climates with shallow water tables.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  13. Promoting the Market for Plug-in Hybrid and Battery Electric Vehicles: Role of Recharge Availability

    SciTech Connect

    Lin, Zhenhong; Greene, David L

    2012-01-01

    Much recent attention has been drawn to providing adequate recharge availability as a means to promote the battery electric vehicle (BEV) and plug-in hybrid electric vehicle (PHEV) market. The possible role of improved recharge availability in developing the BEV-PHEV market and the priorities that different charging options should receive from the government require better understanding. This study reviews the charging issue and conceptualizes it into three interactions between the charge network and the travel network. With travel data from 3,755 drivers in the National Household Travel Survey, this paper estimates the distribution among U.S. consumers of (a) PHEV fuel-saving benefits by different recharge availability improvements, (b) range anxiety by different BEV ranges, and (c) willingness to pay for workplace and public charging in addition to home recharging. With the Oak Ridge National Laboratory MA3T model, the impact of three recharge improvements is quantified by the resulting increase in BEV-PHEV sales. Compared with workplace and public recharging improvements, home recharging improvement appears to have a greater impact on BEV-PHEV sales. The impact of improved recharging availability is shown to be amplified by a faster reduction in battery cost.

  14. Recharge into Southern High Plains aquifer—possible mechanisms, unresolved questions

    NASA Astrophysics Data System (ADS)

    Nativ, Ronit

    1992-01-01

    The High Plains aquifer in the Southern High Plains (Texas and New Mexico), consisting of Tertiary, Cretaceous, and Triassic formations, has traditionally been considered to be recharged by its uppermost water-bearing unit, the Tertiary Ogallala aquifer. This article provides hydrologic, chemical, and isotopic evidence that in the Southern High Plains: (1) Cretaceous rocks actually contain independent recharge sources; (2) Triassic rocks cannot currently be recharged by the Ogallala aquifer in significant quantities; and (3) in places, both Cretaceous and Triassic aquifers recharge the overlying Ogallala aquifer. On the basis of chemical and isotopic data, playa lakes seem to act as the predominant recharge source of the Ogallala aquifer, suggesting recharge rates greater than 30 mm/yr, as opposed to the much lower rates reported by others. The Cretaceous aquifers are being recharged by cross-formational flow from the Ogallala aquifer but also from overlying Quaternary sands and the underlying Triassic aquifer in eastern New Mexico. Current recharge into the Triassic aquifer may be insignificant.

  15. Hydropedologic Analysis of Ground-Water Recharge at the Field Scale

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estimating ground-water recharge is an important element in water resources characterization, vulnerability assessment, and utilization. Contaminant sources often occur in the unsaturated zone where ground-water recharge may mobilize it to migrate into a water table aquifer. Cumulative soil water...

  16. 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...

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

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

    USGS Publications Warehouse

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

    2004-01-01

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

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

    USGS Publications Warehouse

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

    2015-01-01

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

  20. 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 ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. Silicon nanowires as a rechargeable template for hydride transfer in redox biocatalysis

    NASA Astrophysics Data System (ADS)

    Lee, Hwa Young; Kim, Jae Hong; Son, Eun Jin; Park, Chan Beum

    2012-11-01

    We report a new possible application of hydrogen-terminated silicon nanowires (H-SiNWs) as a rechargeable template for hydride transfer in redox biocatalysis. H-SiNWs transfer hydride efficiently to regenerate NADH by oxidizing Si-Hx bonds. The oxidized H-SiNWs were readily recharged for the continuous regeneration of NADH and enzymatic reactions.

  3. La participation des enfants et des adolescents à la boxe

    PubMed Central

    Purcell, Laura K; LeBlanc, Claire MA

    2012-01-01

    RÉSUMÉ Des milliers de garçons et de filles de moins de 19 ans font de la boxe en Amérique du Nord. Même si la boxe comporte des avantages pour ceux qui y participent, y compris l’exercice, l’autodiscipline et la confiance en soi, le sport lui-même favorise et récompense des coups délibérés à la tête et au visage. Les personnes qui font de la boxe risquent de subir des blessures à la tête, au visage et au cou, y compris des traumatismes neurologiques chroniques et même fatals. Les commotions cérébrales sont l’une des principales blessures causées par la boxe. En raison du risque de blessures crâniennes et faciales, la Société canadienne de pédiatrie et l’American Academy of Pediatrics s’opposent vigoureusement à la boxe comme activité sportive pour les enfants et les adolescents. Ces organismes recommandent que les médecins s’élèvent contre la boxe auprès des jeunes et les encouragent à participer à d’autres activités dans lesquelles les coups intentionnels à la tête ne constituent pas un élément essentiel du sport.

  4. Coupled Model Development between Groundwater Recharge Quantity and Climate Change in Nakdong River Watershed using GIS

    NASA Astrophysics Data System (ADS)

    Lee, M.; Jeongho, L.; Changsub, S.; SeongWoo, J.

    2011-12-01

    : Global climate change is disturbing the water circulation balance by changing rates of precipitation, recharge and discharge, and evapotranspiration. Groundwater, which occupies a considerable portion of the world's water resources, is related to climate change via surface water such as rivers, lakes, and marshes. In this study, the authors selected a relevant climate change scenario, A1B from the Special Report on Emission Scenario (SRES) which is distributed at Korea Meteorological Administration. By using data on temperature, rainfall, soil, and land use, the groundwater recharge rate for the research area was estimated by periodically and embodied as geographic information system (GIS). In order to calculate the groundwater recharge quantity, Visual HELP3 was used as main model, and the physical properties of weather, temperature, and soil layers were used as main input data. General changes to water circulation due to climate change have already been predicted. In order to systematically solve problems of ground circulation system, it may be urgent to recalculate the groundwater recharge quantity and consequent change under future climate change. The space-time calculation of changes of the groundwater recharge quantity in the study area may serve as a foundation to present additional measures to improve domestic groundwater resource management. Results showed that 26.19% of total precipitation was recharged from 1971 to 2000, 27.37% will be recharged from 2001 to 2030, 27.43% will be recharged from 2031 to 2050, and 26.06% will be recharged from 2051 to 2070, 27.88% will be recharged from 2051 to 2100. The groundwater recharge rate in this research showed susceptibility to changes in precipitation. The recharge rate was relatively little affected by the changes in Curve Number (CN), but it was rapidly reduced, as it approached the impermeable layers. Accordingly, the findings herein provide a basis for establishment of national plans on water resources management, use of groundwater in local areas for the purpose of settlement, and estimation of groundwater recharge quantities in areas where the groundwater hydrology is not measured. KEY WORDS: Groundwater recharge; Climate change; Curve Number; Special Report on Emissions Scenarios; Intergovernmental Panel on Climate Change

  5. Spatio-temporal recharge patterns in a semi-arid alluvial basin with irrigated crops

    NASA Astrophysics Data System (ADS)

    Ruud, N. C.; Harter, T.; Naugle, A. W.

    2001-12-01

    Recharge in semi-arid regions with irrigated crops is predominantly driven by irrigation technology and cropping patterns, but also by the seasonal distribution of rainfall and the availability of irrigation water. A significant amount of basin recharge occurs from ephemeral streams and unlined irrigation canals. A spatially distributed, GIS-based hydrologic model of water application and water use at the land-atmosphere interface was developed to estimate transient recharge to the deep vadose zone and into the unconfined alluvial aquifer. The spatial basis for the hydrologic model are individual landuse units (diffuse recharge) and a network of streams and canals with water seepage (lineal recharge). The land-atmosphere interface and unsaturated zone model component (LAIUZ) is coupled to a surface water supply model component (SWSM) that provides surface water deliveries by district or sub-district, depending on available information. Using LAIUZ and SWSM, we investigate the regional behavior and spatio-temporal variability of deep vadose zone recharge in the 3,800 square kilometer Tule groundwater basin of the San Joaquin Valley, California. Surface water management in the topographically flat basin is divided between two dozen irrigation and water districts. All surface water is imported or is natural discharge into the basin. Groundwater extractions are managed by landowners on a field-by-field basis. Monthly varying recharge and groundwater pumping rates are computed for the hydrologic years 1970 through 2000. The average size of the GIS landuse units is 0.4 sq. kilometers. The GIS coverage distinguishes over 60 landuse types. Applied and consumptive water use are computed based on actual evapotranspiration and known irrigation or water use efficiencies for each landuse unit. Seepage from streams is computed by mass balance. The resulting model estimates of groundwater recharge and pumping are in good agreement with measured groundwater level changes for the thirty-year period (model validation). Throughout the region, the deep vadose zone (up to 30 m deep) is found to account for a significant amount of intermediate-term basin storage, particularly during wet year cycles. The hydrologic model demonstrates that practically all of the annual precipitation (230 mm) is available for intermediate storage in the root zone, crop water uptake, or deep percolation. No direct losses to evaporation occur, presumably because most precipitation occurs during the winter months. Diffuse recharge is 110 mm/year (range: 38 - 200 mm/year). Lineal recharge accounts for one-third of the total recharge (170 mm/year) in the basin. In wet years, lineal recharge along streams and in intentional recharge basins may account for over 50% of the total recharge, whereas in dry years it may be as little as 8%.

  6. Pathogen Decay during Managed Aquifer Recharge at Four Sites with Different Geochemical Characteristics and Recharge Water Sources.

    PubMed

    Sidhu, J P S; Toze, S; Hodgers, L; Barry, K; Page, D; Li, Y; Dillon, P

    2015-09-01

    Recycling of stormwater water and treated effluent via managed aquifer recharge (MAR) has often been hampered because of perceptions of low microbiological quality of recovered water and associated health risks. The goal of this study was to assess the removal of selected pathogens in four large-scale MAR schemes and to determine the influence of aquifer characteristics, geochemistry, and type of recharge water on the pathogen survival times. Bacterial pathogens tested in this study had the shortest one log removal time (, <3 d), followed by oocysts (, <120 d), with enteric viruses having the biggest variability in removal times (, 18 to >200 d). Human adenovirus and rotavirus were relatively persistent under anaerobic conditions (, >200 d). Human adenovirus survived longer than all the other enteric virus tested in the study and hence could be used as a conservative indicator for virus removal in groundwater during MAR. The results suggest that site-specific subsurface conditions such as groundwater chemistry can have considerable influence on the decay rates of enteric pathogens and that viruses are likely to be the critical pathogens from a public health perspective. PMID:26436258

  7. Recharge sources and hydrogeochemical evolution of groundwater in the coal-mining district of Jiaozuo, China

    NASA Astrophysics Data System (ADS)

    Huang, Pinghua; Chen, Jiansheng

    2012-06-01

    Investigations in the Jiaozuo coal-mining district (China) aim to link water-inrush aquifers with the sources of groundwater recharge. Concentrations of TDS, HCO{3/-}, Cl- and Na+ in the groundwater samples gradually decrease with increasing depth; in contrast, the factor 1 value of the Q-mode analysis gradually increases, which indicates that the deep groundwater may upflow, recharging the aquifers near the faulted zone. Some groundwater samples (above the local meteoric water line and `evaporation line 1') may originate from recharge by infiltrating local rainfall. Spring and river samples are symmetrically distributed on the regression line of the Ordovician and Carboniferous limestone aquifer groundwater (?2H = 3.76 × ?18O - 31.77) and may, therefore, originate from groundwater recharge in the northern Taihang mountains. This mechanism is supported by the observation that groundwater levels change with rainfall. According to radiocarbon residence-time estimates, two groundwater sample sites may have been recharged during the late glacial stage.

  8. A room-temperature sodium rechargeable battery using an SO2-based nonflammable inorganic liquid catholyte

    NASA Astrophysics Data System (ADS)

    Jeong, Goojin; Kim, Hansu; Sug Lee, Hyo; Han, Young-Kyu; Hwan Park, Jong; Hwan Jeon, Jae; Song, Juhye; Lee, Keonjoon; Yim, Taeeun; Jae Kim, Ki; Lee, Hyukjae; Kim, Young-Jun; Sohn, Hun-Joon

    2015-08-01

    Sodium rechargeable batteries can be excellent alternatives to replace lithium rechargeable ones because of the high abundance and low cost of sodium; however, there is a need to further improve the battery performance, cost-effectiveness, and safety for practical use. Here we demonstrate a new type of room-temperature and high-energy density sodium rechargeable battery using an SO2-based inorganic molten complex catholyte, which showed a discharge capacity of 153?mAh g-1 based on the mass of catholyte and carbon electrode with an operating voltage of 3?V, good rate capability and excellent cycle performance over 300 cycles. In particular, non-flammability and intrinsic self-regeneration mechanism of the inorganic liquid electrolyte presented here can accelerate the realization of commercialized Na rechargeable battery system with outstanding reliability. Given that high performance and unique properties of Na-SO2 rechargeable battery, it can be another promising candidate for next generation energy storage system.

  9. Groundwater recharge to the Gulf Coast aquifer system in Montgomery and Adjacent Counties, Texas

    USGS Publications Warehouse

    Oden, Timothy D.; Delin, Geoffrey N.

    2013-01-01

    Simply stated, groundwater recharge is the addition of water to the groundwater system. Most of the water that is potentially available for recharging the groundwater system in Montgomery and adjacent counties in southeast Texas moves relatively rapidly from land surface to surface-water bodies and sustains streamflow, lake levels, and wetlands. Recharge in southeast Texas is generally balanced by evapotranspiration, discharge to surface waters, and the downward movement of water into deeper parts of the groundwater system; however, this balance can be altered locally by groundwater withdrawals, impervious surfaces, land use, precipitation variability, or climate, resulting in increased or decreased rates of recharge. Recharge rates were compared to the 1971–2000 normal annual precipitation measured Cooperative Weather Station 411956, Conroe, Tex.

  10. Identification of potential artificial groundwater recharge zones in Northwestern Saudi Arabia using GIS and Boolean logic

    NASA Astrophysics Data System (ADS)

    Zaidi, Faisal K.; Nazzal, Yousef; Ahmed, Izrar; Naeem, Muhammad; Jafri, Muhammad Kamran

    2015-11-01

    Identifying potential groundwater recharge zones is a pre-requisite for any artificial recharge project. The present study focuses on identifying the potential zones of Artificial Groundwater Recharge (AGR) in Northwestern Saudi Arabia. Parameters including slope, soil texture, vadose zone thickness, groundwater quality (TDS) and type of water bearing formation were integrated in a GIS environment using Boolean logic. The results showed that 17.90% of the total studied area is suitable for AGR. The identified zones were integrated with the land use/land cover map to avoid agricultural and inhabited lands which reduced the total potential area to 14.24%. Geomorphologically the wadi beds are the most suitable sites for recharge. On the basis of the potential AGR zones closeness to the available recharge water supply (rain water, desalinated sea water and treated waste water) the potential zones were classified as Category A (high priority) and Category B (low priority).

  11. 3H and 14C as tracers of ground-water recharge

    USGS Publications Warehouse

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

    1992-01-01

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

  12. A propos des divergences en théorie des champs quantifiés [83

    NASA Astrophysics Data System (ADS)

    Comme nous le montrons ailleurs1), la causalité impose à la matrice S qui décrit l'évolution d'un système une structure bien déterminée : lorsqu'on développe celle-ci suivant les opérateurs de translation dans l'espace des quanta, les coefficients S^{(i)} left[ {tau ''; u''../tau '; u' \\cdot \\cdot } right] sont des intégrales multiples où n'apparaissent, à cOté des champs liés à un seul point de l'espace temps, que les functions*): D^c (x/y) = D^s (x/y) + _2^i D^1 (x/y) x ne y

  13. Temporal and spatial variability of groundwater recharge on Jeju Island, Korea

    USGS Publications Warehouse

    Mair, Alan; Hagedorn, Benjamin; Tillery, Suzanne; El-Kadi, Aly I.; Westenbroek, Stephen; Ha, Kyoochul; Koh, Gi-Won

    2013-01-01

    Estimates of groundwater recharge spatial and temporal variability are essential inputs to groundwater flow models that are used to test groundwater availability under different management and climate conditions. In this study, a soil water balance analysis was conducted to estimate groundwater recharge on the island of Jeju, Korea, for baseline, drought, and climate-land use change scenarios. The Soil Water Balance (SWB) computer code was used to compute groundwater recharge and other water balance components at a daily time step using a 100 m grid cell size for an 18-year baseline scenario (1992–2009). A 10-year drought scenario was selected from historical precipitation trends (1961–2009), while the climate-land use change scenario was developed using late 21st century climate projections and a change in urban land use. Mean annual recharge under the baseline, drought, and climate-land use scenarios was estimated at 884, 591, and 788 mm, respectively. Under the baseline scenario, mean annual recharge was within the range of previous estimates (825–959 mm) and only slightly lower than the mean of 902 mm. As a fraction of mean annual rainfall, mean annual recharge was computed as only 42% and less than previous estimates of 44–48%. The maximum historical reported annual pumping rate of 241 × 106 m3 equates to 15% of baseline recharge, which is within the range of 14–16% computed from earlier studies. The model does not include a mechanism to account for additional sources of groundwater recharge, such as fog drip, irrigation, and artificial recharge, and may also overestimate evapotranspiration losses. Consequently, the results presented in this study represent a conservative estimate of total recharge.

  14. Temporal and spatial variability of groundwater recharge on Jeju Island, Korea

    NASA Astrophysics Data System (ADS)

    Mair, Alan; Hagedorn, Benjamin; Tillery, Suzanne; El-Kadi, Aly I.; Westenbroek, Stephen; Ha, Kyoochul; Koh, Gi-Won

    2013-09-01

    Estimates of groundwater recharge spatial and temporal variability are essential inputs to groundwater flow models that are used to test groundwater availability under different management and climate conditions. In this study, a soil water balance analysis was conducted to estimate groundwater recharge on the island of Jeju, Korea, for baseline, drought, and climate-land use change scenarios. The Soil Water Balance (SWB) computer code was used to compute groundwater recharge and other water balance components at a daily time step using a 100 m grid cell size for an 18-year baseline scenario (1992-2009). A 10-year drought scenario was selected from historical precipitation trends (1961-2009), while the climate-land use change scenario was developed using late 21st century climate projections and a change in urban land use. Mean annual recharge under the baseline, drought, and climate-land use scenarios was estimated at 884, 591, and 788 mm, respectively. Under the baseline scenario, mean annual recharge was within the range of previous estimates (825-959 mm) and only slightly lower than the mean of 902 mm. As a fraction of mean annual rainfall, mean annual recharge was computed as only 42% and less than previous estimates of 44-48%. The maximum historical reported annual pumping rate of 241 × 106 m3 equates to 15% of baseline recharge, which is within the range of 14-16% computed from earlier studies. The model does not include a mechanism to account for additional sources of groundwater recharge, such as fog drip, irrigation, and artificial recharge, and may also overestimate evapotranspiration losses. Consequently, the results presented in this study represent a conservative estimate of total recharge.

  15. Chloride-mass-balance for predicting increased recharge after land-use change

    SciTech Connect

    Gee, G.W.; Zhang, Z.F.; Tyler, S.W.; Albright, W.H.; Singleton, M.J.

    2004-02-23

    The chloride-mass-balance (CMB) method has been used extensively to estimate recharge in arid and semi-arid environments. Required data include estimates of annual precipitation, total chloride input (from dry fallout and precipitation), and pore-water chloride concentrations. Typically, CMB has been used to estimate ancient recharge but recharge from recent land-use change has also been documented. Recharge rates below a few mm/yr are reliably detected with CMB; however, estimates above a few mm/yr appear to be less reliable. We tested the CMB method against 26 years of drainage from a 7.6-m-deep lysimeter at a simulated waste-burial ground, located on the Department of Energy s Hanford Site in southeastern Washington State, USA where land-use change has increased recharge rates. Measured drainage from the lysimeter for the past 26 years averaged 62 mm/yr. Precipitation averaged 190 mm/yr with an estimated chloride input of 0.225 mg/L. Initial pore-water chloride concentration was 88 mg/L and decreased to about 6 mg/L after 26 years, while the drainage water decreased to less than 1 mg/L. A recharge estimate made using chloride concentrations in drain water was within 20 percent of the measured drainage rate. In contrast, recharge estimates using 1:1 (water: soil) extracts were lower than actual by factors ranging from 2 to 8 or more. The results suggest that when recharge is above a few mm/yr, soil water extracts can lead to unreliable estimates of recharge. For conditions of elevated recharge, direct sampling of pore water is the preferred method, because chloride concentrations are often 20 to 50 times higher in directly-sampled pore water than in pore-water extracts.

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

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

    Groundwater recharge is likely to be impacted by climate change, with changes in precipitation amounts altering moisture availability and changes in temperature affecting evaporative demand. This could have major implications for sustainable aquifer pumping rates and contaminant transport into groundwater reservoirs in the future, thus making predictions of recharge under climate change very important. Unfortunately, in dry environments where groundwater resources are often most critical, low recharge rates are difficult to resolve due to high sensitivity to modeling and input errors. Some recent studies on climate change and groundwater have considered recharge using a suite of general circulation model (GCM) weather predictions, an obvious and key source of uncertainty. This work extends beyond those efforts by also accounting for uncertainty in other land-surface model inputs in a probabilistic manner. Recharge predictions are made using a range of GCM projections for a rain-fed cotton site in the semi-arid Southern High Plains region of Texas. Results showed that model simulations using a range of unconstrained literature-based parameter values produce highly uncertain and often misleading recharge rates. Thus, distributional recharge predictions are found using soil and vegetation parameters conditioned on current unsaturated zone soil moisture and chloride concentration observations; assimilation of observations is carried out with an ensemble importance sampling method. Our findings show that the predicted distribution shapes can differ for the various GCM conditions considered, underscoring the importance of probabilistic analysis over deterministic simulations. The recharge predictions indicate that the temporal distribution (over seasons and rain events) of climate change will be particularly critical for groundwater impacts. Overall, changes in recharge amounts and intensity were often more pronounced than changes in annual precipitation and temperature, thus suggesting high susceptibility of groundwater systems to future climate change. Our approach provides a probabilistic sensitivity analysis of recharge under potential climate changes, which will be critical for future management of water resources.

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  18. Use of Constructed Wetlands for Polishing Recharge Wastewater

    NASA Astrophysics Data System (ADS)

    Cardwell, W.

    2009-12-01

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

  19. Climate Change Effects on Groundwater Recharge East of Yucca Mountain

    NASA Astrophysics Data System (ADS)

    Woocay, A.; Walton, J. C.

    2007-12-01

    In order to better understand the general flow system and climate-induced changes in recharge around Fortymile Wash, near Yucca Mountain, groundwater geochemical data from the Amargosa Desert region were analyzed. Also, chloride mass balance (CMB) was applied to drill cuttings from borehole NC-EWDP-22S near Fortymile Wash. Stable isotopic hydrogen-2 and oxygen-18 data indicate that less depleted groundwater is found under the flowpath of Fortymile Wash compared with groundwater perpendicular to the wash, and in the lower end of the wash compared with the source in the canyon. In addition, water isotope data under Fortymile Wash plot below the global meteoric water line (GMWL), suggesting low evaporation before infiltration. Total dissolved solids (TDS) and chloride (Cl) concentrations are lowest in the groundwater along the wash indicating less rock/water interaction and low evaporation prior to infiltration. In consequence, stable isotope, TDS and Cl data are most consistent with a pattern of infiltration and recharge of surface runoff subsequent to runoff-generating storms. Carbon-14 data corrected with carbon-13 data presents ages between 8,000 years before present (BP) in the upper canyon region and 14,000 years BP in the lower region near the Amargosa Desert. This range in ages corresponds to the end of the Pleistocene and early Holocene epochs. In contrast, groundwater adjacent to Fortymile Wash appears to be older than that beneath the wash. Furthermore, the trend of groundwater age increase and further stable isotope depletion beneath Fortymile Wash with increasing distance from the canyon suggests that the average reach of recharge and runoff events diminished over time as the climate became warmer and dryer. CMB results present two different pore velocities, the slower one nearer to the surface and with the transition occurring between 6 and 26 meters in depth corresponding to 8,5000 and 11,000 BP. Considered together, these facts suggest that ground water under Fortymile Wash is not derived primarily from migration of adjacent ground water, as indicated by coarse contoured water levels, but instead from past focused infiltration that diminished due to a changing climate.

  20. Les Applications Therapeutiques Des Lasers

    NASA Astrophysics Data System (ADS)

    Brunetaud, J. M.; Mordon, S.; Bourez, J.; Mosquet, L.; Moschetto, Y.

    1984-03-01

    C'est de tres loin le mecanisme predominant dans les applications therapeutiques du laser. En concentrant le flux lumineux sur une surface redui-te, le laser chauffe localement les tissus qui se retractent (coagulation) pour etre elimines ensuite (detersion) ; si on chauffe plus intensement, les tissus peuvent etre volatilises. La coagulation est utilisee soit pour detruire de petits phenomenes tumoraux qui seront elimines lors du processus de detersion, soit pour arreter une hemorragie (hemo-stase) ; dans ce cas la retraction thermique des tissus va provoquer la fermeture de la lumiere des vaisseaux qui seront secondairement obliteres par des caillots formes sur place (thrombose). Par volatilisation it est possible de detruire des phenomenes tumoraux plus importants que ceux at-teints lors d'une simple coagulation. Si la zone volatilisee est tres etroite (de 0,1 a 1 mm) on obtient un effet de coupe avec une excellente hemostase au niveau des berges. Certes ces deux processus - coagulation et volatilisation - peuvent etre obtenus par d'autres procedes : echauffement par contact (sonde thermique) ou effet Joule (courant electrique haute frequence). Le laser a l'avantage de ne necessiter aucun contact mecanique entre le vecteur d'energie et les tissus ; on peut alors predire correctement la repartition d'energie au niveau des tissus et les effets sont tres repro-ductibles. Par ailleurs, l'absorption tissulaire variant considerablement avec la longueur d'onde on peut choisir la source laser en fonction des effets desires.

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

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

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

  2. Médecine des voyages

    PubMed Central

    Aw, Brian; Boraston, Suni; Botten, David; Cherniwchan, Darin; Fazal, Hyder; Kelton, Timothy; Libman, Michael; Saldanha, Colin; Scappatura, Philip; Stowe, Brian

    2014-01-01

    Résumé Objectif Définir la pratique de la médecine des voyages, présenter les éléments fondamentaux d’une consultation complète préalable aux voyages à des voyageurs internationaux et aider à identifier les patients qu’il vaudrait mieux envoyer en consultation auprès de professionnels de la médecine des voyages. Sources des données Les lignes directrices et les recommandations sur la médecine des voyages et les maladies liées aux voyages publiées par les autorités sanitaires nationales et internationales ont fait l’objet d’un examen. Une recension des ouvrages connexes dans MEDLINE et EMBASE a aussi été effectuée. Message principal La médecine des voyages est une spécialité très dynamique qui se concentre sur les soins préventifs avant un voyage. Une évaluation exhaustive du risque pour chaque voyageur est essentielle pour mesurer avec exactitude les risques particuliers au voyageur, à son itinéraire et à sa destination et pour offrir des conseils sur les interventions les plus appropriées en gestion du risque afin de promouvoir la santé et prévenir les problèmes médicaux indésirables durant le voyage. Des vaccins peuvent aussi être nécessaires et doivent être personnalisés en fonction des antécédents d’immunisation du voyageur, de son itinéraire et du temps qu’il reste avant son départ. Conclusion La santé et la sécurité d’un voyageur dépendent du degré d’expertise du médecin qui offre le counseling préalable à son voyage et les vaccins, au besoin. On recommande à ceux qui donnent des conseils aux voyageurs d’être conscients de l’ampleur de cette responsabilité et de demander si possible une consultation auprès de professionnels de la médecine des voyages pour tous les voyageurs à risque élevé.

  3. Rechargeable cells with modified MnO2 cathodes

    NASA Astrophysics Data System (ADS)

    Dzieciuch, M. A.; Gupta, N.; Wroblowa, H. S.

    1988-10-01

    The recent invention of rechargeable 'modified' manganese oxide materials paves the way to the development of secondary batteries suitable for numerous applications. This includes alternatives to primary dry cells, and secondary lead/acid and nickel-cadmium batteries. Present results describe the performance of cells in which the modified materials are coupled with zinc and iron. As opposed to iron which does not affect the longevity and capacity retention of the modified electrodes, zinc has a pejorative effect on modified MnO2 materials, owing to the formation of heterolite at the positive electrode. Methods to alleviate this effect and produce viable modified MnO2/Zn systems are described. At present, these systems retain about 50 percent of their theoretical one-electron capacity even after two hundred fast charge-discharge cycles.

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

    USGS Publications Warehouse

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

    2013-01-01

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

  5. Status of the development of rechargeable lithium cells

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

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

    PubMed

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

    2015-04-01

    Groundwater in the Todos Santos watershed in southern Baja California, and throughout the peninsula south of latitude 28°N, has values of (δ18 O‰, δD‰) 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 δ18O values<-10‰ in comparison with amount-weighted mean summer and fall rain at -6‰. Isotope data indicate hurricane rain as the predominant source of recharge in southern Baja California, where named tropical depressions bring large rains (>50 mm) at least once every 2 to 3 years, and along the Pacific coast between Jalisco and Oaxaca. PMID:24635484

  7. A rechargeable hydrogen battery based on Ru catalysis.

    PubMed

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

    2014-07-01

    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

  8. Layered cathode materials for lithium ion rechargeable batteries

    DOEpatents

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

    2007-04-17

    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.

  9. Resilient design of recharging station networks for electric transportation vehicles

    SciTech Connect

    Kris Villez; Akshya Gupta; Venkat Venkatasubramanian

    2011-08-01

    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.

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

    SciTech Connect

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

    1990-01-01

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

  11. Overcharge protection for rechargeable lithium polymer electrolyte batteries

    SciTech Connect

    Richardson, T.J.; Ross, P.N. Jr.

    1996-12-01

    Overcharge protection for rechargeable lithium polymer electrolyte cells by addition of redox shuttle additives to the polymer electrolyte was examined. Shuttle onset potentials and effective diffusion coefficients were determined for 12 redox shuttle species in polyethylene oxide-based electrolytes at 85 C. The four most promising additives were tested in Li/PEO-LiN(SO{sub 2}CF{sub 3}){sub 2}/Li{sub 2+x}Mn{sub 4}O{sub 9} cells under normal and severe overcharging conditions. In addition to tricyanobenzene and tetracyanoquinodimethane, two anionic redox shuttle additives, salts of 1,2,4-triazole and imidazole, demonstrated effectiveness in extending cycle life and good compatibility with cell components.

  12. Response to recharge variation of thin rainwater lenses and their mixing zone with underlying saline groundwater

    NASA Astrophysics Data System (ADS)

    Eeman, S.; van der Zee, S. E. A. T. M.; Leijnse, A.; de Louw, P. G. B.; Maas, C.

    2012-10-01

    In coastal zones with saline groundwater, fresh groundwater lenses may form due to infiltration of rain water. The thickness of both the lens and the mixing zone, determines fresh water availability for plant growth. Due to recharge variation, the thickness of the lens and the mixing zone are not constant, which may adversely affect agricultural and natural vegetation if saline water reaches the root zone during the growing season. In this paper, we study the response of thin lenses and their mixing zone to variation of recharge. The recharge is varied using sinusoids with a range of amplitudes and frequencies. We vary lens characteristics by varying the Rayleigh number and Mass flux ratio of saline and fresh water, as these dominantly influence the thickness of thin lenses and their mixing zone. Numerical results show a linear relation between the normalised lens volume and the main lens and recharge characteristics, enabling an empirical approximation of the variation of lens thickness. Increase of the recharge amplitude causes increase and the increase of recharge frequency causes a decrease in the variation of lens thickness. The average lens thickness is not significantly influenced by these variations in recharge, contrary to the mixing zone thickness. The mixing zone thickness is compared to that of a Fickian mixing regime. A simple relation between the travelled distance of the centre of the mixing zone position due to variations in recharge and the mixing zone thickness is shown to be valid for both a sinusoidal recharge variation and actual records of daily recharge data. Starting from a step response function, convolution can be used to determine the effect of variable recharge in time. For a sinusoidal curve, we can determine delay of lens movement compared to the recharge curve as well as the lens amplitude, derived from the convolution integral. Together the proposed equations provide us with a first order approximation of lens characteristics using basic lens and recharge parameters without the use of numerical models. This enables the assessment of the vulnerability of any thin fresh water lens on saline, upward seeping groundwater to salinity stress in the root zone.

  13. Managed aquifer recharge with low impact development under a changing climate (Invited)

    NASA Astrophysics Data System (ADS)

    Gurdak, J. J.; Newcomer, M. E.; Sklar, L. S.; Nanus, L.

    2013-12-01

    Groundwater resources in urban environments are highly vulnerable to human pressures and climate variability and change, and many communities face water shortages and need to find alternative water supplies. Therefore, understanding how low impact development (LID) planning and best management practices (BMPs) affect recharge rates and volumes is important because of the increasing use of LID and BMPs to reduce stormwater runoff and improve surface-water quality. Some BMPs may also enhance recharge, which has often been considered a secondary management benefit. Enhancing the capacity for managed aquifer recharge with stormwater beneath LID is an important step toward the sustainable and conjunctive use of surface and groundwater resources in urban environments. This field and modeling study quantifies urban recharge rates, volumes, and efficiency beneath a BMP infiltration trench and irrigated lawn considering historical El Niño/Southern Oscillation (ENSO) variability and future climate change using simulated precipitation from the Geophysical Fluid Dynamic Laboratory (GFDL) A1F1 climate scenario. Using results from a suite of methods to measure and model recharge beneath a recently installed (2009) BMP infiltration trench, this study addresses three main questions: (1) What are the benefits of measuring recharge using in-situ methods compared to model-based and other simple estimates of recharge beneath a LID BMP? (2) What are recharge rates and volumes beneath the infiltration trench, how do they compare to an irrigated lawn that represents a non-LID source of urban recharge, and what are the important factors controlling recharge beneath the two sites? (3) How effective is the LID BMP in capturing and recharging urban stormwater considering historical ENSO variability and future climate change? 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. Recharge rates beneath the infiltration trench (1,620 to 3,710 mm yr- 1) were an order-of-magnitude greater than beneath the irrigated lawn (130 to 730 mm yr-1). Beneath the infiltration trench, recharge rates ranged from 1,390 to 5,840 mm yr-1 and averaged 3,410 mm yr-1 for El Niño years and from 1,540 to 3,330 mm yr-1 and averaged 2,430 mm yr-1 for La Niña years. We demonstrate a clear benefit for recharge and local groundwater resources using small, spatially distributed stormwater retention BMPs. This study provides the first field- and model-based estimates of recharge rates and volumes beneath BMPs considering climate variability and change, and provides practical management information regarding enhanced stormwater capture and recharge toward improved conjunctive use of water resources in urban environments.

  14. Estimating groundwater recharge beneath irrigated farmland using environmental tracers fluoride, chloride and sulfate

    NASA Astrophysics Data System (ADS)

    Lin, Dan; Jin, Menggui; Liang, Xing; Zhan, Hongbin

    2013-11-01

    Accurate recharge estimation is essential for effective groundwater management, especially in the North China Plain, where irrigation return flow is significant to vertical recharge but brings difficulty for recharge estimation. Three environmental tracers (F-, Cl- and SO4 2-) were used to estimate vertical recharge based on the mass balance and cumulative methods. Four boreholes were dry-drilled to 5-25 m depth beneath irrigated farmland and one was drilled to 5 m beneath non-irrigated woodland; soil samples were collected in all boreholes at set depths. The results indicated that F-, Cl- and SO4 2-were suitable tracers beneath the non-irrigated woodland, yielding recharge rates of 16.9, 18.8 and 19.4 mm/year, respectively. Recharge estimation was not straightforward when taking account of crop type, irrigation and/or fertilizer use. After comparing with previous research, conclusions were drawn: Cl- was an appropriate tracer for irrigated farmland when taking account of Cl- input from irrigation and absorption by crops; recharge rates were 65.9-126.8 mm/year. However, F- was a more suitable tracer for irrigated regions where account is made of the proportion of precipitation to irrigation return flow, provided low F- concentrations can be measured reliably.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  16. Interactions of diffuse and focused allogenic recharge in an eogenetic karst aquifer (Florida, USA)

    NASA Astrophysics Data System (ADS)

    Langston, Abigail L.; Screaton, Elizabeth J.; Martin, Jonathan B.; Bailly-Comte, Vincent

    2012-06-01

    The karstic upper Floridan aquifer in north-central Florida (USA) is recharged by both diffuse and allogenic recharge. To understand how recharged water moves within the aquifer, water levels and specific conductivities were monitored and slug tests were conducted in wells installed in the aquifer surrounding the Santa Fe River Sink and Rise. Results indicate that diffuse recharge does not mix rapidly within the aquifer but instead flows horizontally. Stratification may be aided by the high matrix porosity of the eogenetic karst aquifer. Purging wells for sample collection perturbed conductivity for several days, reflecting mixing of the stratified water and rendering collection of representative samples difficult. Interpretive numerical simulations suggest that diffuse recharge impacts the intrusion of allogenic water from the conduit by increasing hydraulic head in the surrounding aquifer and thereby reducing influx to the aquifer from the conduit. In turn, the increase of head within the conduits affects flow paths of diffuse recharge by moving newly recharged water vertically as the water table rises and falls. This movement may result in a broad vertical zone of dissolution at the water table above the conduit system, with thinner and more focused water-table dissolution at greater distance from the conduit.

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

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

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

  20. Comparison of recharge estimates at a small watershed in east-central Pennsylvania, USA

    USGS Publications Warehouse

    Risser, D.W.; Gburek, W.J.; Folmar, G.J.

    2009-01-01

    The common recommendation that recharge should be estimated from multiple methods is sound, but the inherent differences of the methods make it difficult to assess the accuracy of differing results. In this study, four methods for estimating groundwater recharge and two methods for estimating base flow (as a proxy for recharge) are compared at two hydrologic research sites in east-central Pennsylvania, USA. Results from the multiple methods all provided reasonable estimates of groundwater recharge that differed considerably. The estimates of mean annual recharge for the period 1994-2001 ranged from 22.9 to 35.7 cm - about 45% of the mean of all estimates. For individual years, recharge estimates from the multiple methods ranged from 30 to 42% of the mean value during the dry years and 64 to 76% of the mean value during wet years. Comparison of multiple methods was found to be useful for determining the range of plausible recharge rates and highlighting the uncertainty of the estimates. ?? US Government 2008.

  1. Estimation of natural recharge and its dependency on sub-surface geoelectric parameters

    NASA Astrophysics Data System (ADS)

    Chand, R.; Chandra, S.; Rao, V. A.; Singh, V. S.; Jain, S. C.

    2004-11-01

    Natural groundwater recharge is estimated using the injected tracer technique in the Bairasagara watershed of Kolar district, Karnataka (India) comprising of medium grained granite and granitic gneiss with weathering/fracturing up to 46 m depth. On a macroscopic scale, it is estimated that the weathered granites act as a uniform body having a recharge capacity of about 6-200 mm per annum for an average value of rainfall of 968 mm. Marked differences of infiltration rates (nil to 130 cm/year) were observed under cultivated and dry areas. The water level fluctuation and recharge are found to be minimum in the ayacut area as compared to the catchment area. Studies helped in demarcating recharge and discharge areas. Qualitative correlation studies of estimated natural groundwater recharge have been carried out with depth to basement, resistivity of subsurface layers, and water level fluctuations. An attempt has been made to get empirical relationships between recharge vs. depth to basement, and recharge vs. water level fluctuations. The paper discusses the studies carried out, the result obtained, and the importance of such studies in the evaluation of groundwater resources.

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

    USGS Publications Warehouse

    Anderson, Gary S.

    1977-01-01

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

  3. Iron-Air Rechargeable Battery: A Robust and Inexpensive Iron-Air Rechargeable Battery for Grid-Scale Energy Storage

    SciTech Connect

    2010-10-01

    GRIDS Project: USC is developing an iron-air rechargeable battery for large-scale energy storage that could help integrate renewable energy sources into the electric grid. Iron-air batteries have the potential to store large amounts of energy at low cost—iron is inexpensive and abundant, while oxygen is freely obtained from the air we breathe. However, current iron-air battery technologies have suffered from low efficiency and short life spans. USC is working to dramatically increase the efficiency of the battery by placing chemical additives on the battery’s iron-based electrode and restructuring the catalysts at the molecular level on the battery’s air-based electrode. This can help the battery resist degradation and increase life span. The goal of the project is to develop a prototype iron-air battery at significantly cost lower than today’s best commercial batteries.

  4. Vecteurs Singuliers des Theories des Champs Conformes Minimales

    NASA Astrophysics Data System (ADS)

    Benoit, Louis

    En 1984 Belavin, Polyakov et Zamolodchikov revolutionnent la theorie des champs en explicitant une nouvelle gamme de theories, les theories quantiques des champs bidimensionnelles invariantes sous les transformations conformes. L'algebre des transformations conformes de l'espace-temps presente une caracteristique remarquable: en deux dimensions elle possede un nombre infini de generateurs. Cette propriete impose de telles conditions aux fonctions de correlations qu'il est possible de les evaluer sans aucune approximation. Les champs des theories conformes appartiennent a des representations de plus haut poids de l'algebre de Virasoro, une extension centrale de l'algebre conforme du plan. Ces representations sont etiquetees par h, le poids conforme de leur vecteur de plus haut poids, et par la charge centrale c, le facteur de l'extension centrale, commune a toutes les representations d'une meme theorie. Les theories conformes minimales sont constituees d'un nombre fini de representations. Parmi celles-ci se trouvent des theories unitaires dont les representation forment la serie discrete de l'algebre de Virasoro; leur poids h a la forme h_{p,q}(m)=[ (p(m+1) -qm)^2-1] (4m(m+1)), ou p,q et m sont des entiers positifs et p+q<= m+1. L'entier m parametrise la charge centrale: c(m)=1 -{6over m(m+1)} avec n>= 2. Ces representations possedent un sous-espace invariant engendre par deux sous-representations avec h_1=h_{p,q} + pq et h_2=h_{p,q} + (m-p)(m+1-q) dont chacun des vecteurs de plus haut poids portent le nom de vecteur singulier et sont notes respectivement |Psi _{p,q}> et |Psi_{m-p,m+1-q}>. . Les theories super-conformes sont une version super-symetrique des theories conformes. Leurs champs appartiennent a des representation de plus haut poids de l'algebre de Neveu-Schwarz, une des deux extensions super -symetriques de l'algebre de Virasoro. Les theories super -conformes minimales possedent la meme structure que les theories conformes minimales. Les representations sont elements de la serie h_{p,q}= [ (p(m+2)-qm)^2-4] /(8m(m+2)) ou p,q et m sont des entiers positifs, p et q etant de meme parite, et p+q<= m+2. La charge centrale est donnee par c(m)={3over 2}-{12over m(m+2)} avec m >= 2. Les vecteurs singuliers | Psi_{p,q}> et |Psi_{m-p,m+2-q} > sont respectivement de poids h _{p,q}+pq/2 et h_ {p,q}+(m-p)(m+2-q)/2.. Les vecteurs singuliers ont une norme nulle et on doit les eliminer des representations pour que celles -ci soient unitaires. Cette elimination engendrent des equations (super-)differentielles qui dependent directement de la forme explicite des vecteurs singuliers et auxquelles doivent obeir les fonctions de correlations de la theorie. Ainsi la connaissance de ces vecteurs singuliers est intimement reliee au calcul des fonctions de correlation. Les equations definissant les vecteurs singuliers forment un systeme lineaire surdetermine dont le nombre d'equations est de l'ordre de N(pq), le nombre de partitions de l'entier pq. Puisque les vecteurs singuliers jouent un role capital en theorie conforme, il est naturel de chercher des formes explicites pour les vecteurs (ou pour des familles infinies de ceux -ci). Nous donnons ici la forme explicite pour la famille infinie de vecteurs singuliers ayant un de ses indices egal a 1, pour les algebres de Virasoro et de Neveu-Schwarz. Depuis ces decouvertes, d'autres techniques de construction des vecteurs singuliers ont ete developpees, dont celle de Bauer, Di Francesco, Itzykson et Zuber pour l'algebre de Virasoro qui reproduit directement l'expression explicite des vecteurs singuliers |Psi _{1,q}> et |Psi_{p,1}>. Ils ont utilise l'algebre des produits d'operateurs et la fusion entre representations irreductibles pour engendrer des relations de recurence produisant les vecteurs singuliers. Dans le dernier chapitre de cette these nous adaptons cet algorithme a la construction des vecteurs singuliers de l'algebre de Neveu-Schwarz.

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

    NASA Astrophysics Data System (ADS)

    Ringleb, Jana; Sallwey, Jana; Stefan, Catalin

    2015-04-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

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

  7. Comparative study of climate-change scenarios on groundwater recharge, southwestern Mississippi and southeastern Louisiana, USA

    NASA Astrophysics Data System (ADS)

    Beigi, Ehsan; Tsai, Frank T.-C.

    2015-02-01

    A geographic information system (GIS)-based water-budget framework has been developed to study the climate-change impact on regional groundwater recharge, and it was applied to the Southern Hills aquifer system of southwestern Mississippi and southeastern Louisiana, USA. The framework links historical climate variables and future emission scenarios of climate models to a hydrologic model, HELP3, to quantify spatiotemporal potential recharge variations from 1950 to 2099. The framework includes parallel programming to divide a large amount of HELP3 simulations among multiple cores of a supercomputer, to expedite computation. The results show that a wide range of projected potential recharge for the Southern Hills aquifer system resulted from the divergent projections of precipitation, temperature and solar radiation using three scenarios (B1, A2 and A1FI) of the National Center for Atmospheric Research's Parallel Climate Model 1 (PCM) and the National Oceanic and Atmospheric Administration Geophysical Fluid Dynamics Lab's (GFDL) model. The PCM model projects recharge change ranging from -33.7 to +19.1 % for the 21st century. The GFDL model projects less recharge than the PCM, with recharge change ranging from -58.1 to +7.1 %. Potential recharge is likely to increase in 2010-2039, but likely to decrease in 2070-2099. Projected recharge is more sensitive to the changes in the projected precipitation than the projected solar radiation and temperature. Uncertainty analysis confirms that the uncertainty in projected precipitation yields more changes in the potential recharge than in the projected temperature for the study area.

  8. Artificial Groundwater Recharge Zones Mapping Using Remote Sensing and GIS: A Case Study in Indian Punjab

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

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

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

    USGS Publications Warehouse

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

    2006-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

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

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

    PubMed

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

    2013-07-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  13. Probabilistic Analysis of Rechargeable Batteries in a Photovoltaic Power Supply System

    SciTech Connect

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

    1998-11-24

    We developed a model for the probabilistic behavior of a rechargeable battery acting as the energy storage component in a photovoltaic power supply system. Stochastic and deterministic models are created to simulate the behavior of the system component;. The components are the solar resource, the photovoltaic power supply system, the rechargeable battery, and a load. Artificial neural networks are incorporated into the model of the rechargeable battery to simulate damage that occurs during deep discharge cycles. The equations governing system behavior are combined into one set and solved simultaneously in the Monte Carlo framework to evaluate the probabilistic character of measures of battery behavior.

  14. Linear unit-response functions as indicators of recharge areas for large karst springs

    NASA Astrophysics Data System (ADS)

    Dreiss, Shirley J.

    1983-02-01

    The delineation of groundwater recharge areas for karst springs is important for estimating groundwater supplies and for identifying sources and directions of contaminant movement. This paper suggests the potential utility of spring discharge kernel functions (analogous to instantaneous unit hydrographs for surface runoff) in the identification of the recharge areas of large springs. Examples from southeastern Missouri, U.S.A., show that when consistent methods are used for baseflow separation and excess precipitation determinations, derived linear kernels are most physically realistic and have the least fitting error when the assumed spring recharge area is consistent with tracer study results.

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

    DOEpatents

    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

    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.

  16. Difficulties in determining factors that influence effective groundwater recharge in Ohio

    USGS Publications Warehouse

    Ashooh, J.; Liu, J.; Mueller, E.; Sherer, S.; Woggon, N.; Dumouchelle, D.H.; Eberle, M.

    2003-01-01

    As part of a COSI Academy research project, data from a recent statewide analysis of effective groundwater recharge were reexamined by students to further discern relations between recharge and selected environmental characteristics of individual drainage basins: 1) location of the main stem of a river relative to coarse and fine surficial sediments and 2) influence of land use. Lack of sufficiently detailed data was the principal difficulty in most phases of the examination. Other than a potential relation between recharge and the percentages of agricultural and forested land, no relations were found in visual comparisons of mapped and tabulated data.

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

    USGS Publications Warehouse

    Thompson, Ryan F.

    2002-01-01

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

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

    USGS Publications Warehouse

    Ku, Henry; Hagelin, Nathan; Buxton, Herbert

    1992-01-01

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

  19. The role of compressional tectonics, sedimentary transport and mineral composition on AMS and AARM fabrics. A case study of the flysch from the Dukla nappe, Outer Western Carpatians, Poland

    NASA Astrophysics Data System (ADS)

    Kiss, Dániel; Márton, Em?; Tokarski, Antek K.

    2015-04-01

    The Carpathians belong to the European Alpine system. The Polish segment of the Western Outer Carpathians is a north-verging thrust-and-fold belt composed largely of Lower Cretaceous to Lower Miocene flysch. The belt comprises the Skole, Subsilesian, Silesian, Dukla and Magura rootless nappes. Anisotropy studies were carried out both in Oligocene turbidite sequences of the Dukla nappe and in the olistostrome of the Lipowica quarry. For the study 102 individually oriented cores were drilled at nine geographically distributed localities. At each locality mudstones/claystones were sampled, except Lipowica quarry, where silt and sandstone were also drilled. Because of the relatively low susceptibilities (1-3*10-4 SI), paramagnetic minerals can be important contributors to the AMS fabric. AMS and AARM measurements were carried out and the fabrics were compared. Despite of the weak AMS lineations, the mean lineation direction is well defined in all cases on site/locality level. With one exception where the lineation is perpendicular to the bedding plane (due to the presence of siderite), the AMS lineations can be interpreted as due to compressional tectonics. Concerning the AARM lineations they are highly scattered in the sandstone, show a tendency for alignment in the silt and some of the mudstone/claystone sites, and are well clustered in the other cases. The AARM lineations for four localities correlate to the AMS, and the local strike. The AARM lineation of the siderite bearing rock is also sub-parallel to the local strike. In the remaining cases the AARM linations are suspected to be related to sedimentary transport. Due to the lack of solemarks at most localities this will be investigated systematically with photo-statistical grain shape analysis in oriented thin sections. X-ray diffraction measurements also will be carried out to identify the paramagnetic contributors to the AMS. Acknowledgments: This work was partly financed by the Hungarian Research Fund (OTKA) project no. K105245 and from a joint project of the Academies of Science of Poland and Hungary.

  20. Field experiments and numerical simulations of confined aquifer response to multi-cycle recharge-recovery process through a well

    NASA Astrophysics Data System (ADS)

    Wang, Jianxiu; Wu, Yuanbin; Zhang, Xingsheng; Liu, Yan; Yang, Tianliang; Feng, Bo

    2012-09-01

    SummaryShanghai is one of the cities suffering from land subsidence in China. Land subsidence has caused serious financial losses. Thus, artificial recharge measures have been adopted to compensate the drawdown in shallow, confined aquifers and thereby control land subsidence. In this study, a multi-cycle recharge-recovery field experiment was performed to investigate the response of a shallow, confined aquifer to artificial recharge through a well. In the experiment, a series of recharge-recovery cycles with different recharge volumes and durations, with and without artificial pressure, were performed. The water levels monitored in the recharge and observation wells indicated the response of the aquifer to the multi-cycle recharge-recovery process. Meanwhile, a finite-difference method (FDM) numerical model was established, and its parameters were obtained via a reversed numerical analysis on the experimental data. The responses of the shallow, confined aquifer to the multi-cycle recharge-recovery process were simulated in detail using the model. The calculation results showed that the water level dropped significantly when the recharge ended. Moreover, the efficiency of a multi-cycle recharge was found to be higher than that of a concentrated one under the same recharge volume and time. The relationship between recharge frequency and efficiency, expressed as H = 0.29498 f0.40163 and R2 = 0.97264, respectively, was obtained through the FDM numerical simulation. In the recharge intervals, the optimal recharge efficiency was achieved when the water level rose to 40% of the peak.

  1. Can we quantify local groundwater recharge using electrical resistivity tomography?

    NASA Astrophysics Data System (ADS)

    Noell, U.; Günther, T.; Ganz, C.; Lamparter, A.

    2012-04-01

    Electrical resistivity tomography (ERT) has become a common tool to observe flow processes within the saturated/unsaturated zones. While it is still doubtful whether the method can reliably yield quantitative results the qualitative success has been shown in "numerous" examples. To quantify the rate of rainfall which reaches the groundwater table is still a problematic venture due to a sad combination of several physical and mathematical obstacles that may lead to huge errors. In 2007 an infiltration experiment was performed and observed using 3D array ERT. The site is located close to Hannover, Germany, on a well studied sandy soil. The groundwater table at this site was at a depth of about 1.3 m. The inversion results of the ERT data yield reliably looking pictures of the infiltration process. Later experiments nearby using tracer fluid and combined TDR and resistivity measurements in the subsurface strongly supported the assumption that the resistivity pictures indeed depict the water distributions during infiltration reliably. The quantitative interpretation shows that two days after infiltration about 40% of the water has reached the groundwater. However, the question remains how reliable this quantitative interpretation actually is. The first obstacle: The inversion of the ERT data gives one possible resistivity distribution within the subsurface that can explain the data. It is not necessarily the right one and the result depends on the error model and the inversion parameters and method. For these measurements we assume the same error for every single quadrupole (3%), applied the Gauss-Newton method and minimum length constraints in order to reduce the smoothing to a minimum (very small lambda). Numerical experiments showed little smoothing using this approach, and smoothing must be suppressed if preferential flow is to be seen. The inversion showed artefacts of minor amplitude compared with other inversion parameter settings. The second obstacle: The petrophysical function that relates the resistivity changes to water content changes is doubtful. This relationship was constructed by two ways; firstly by comparing in situ measured water contents and the ERT inversion results, secondly by laboratory measurements of soil samples taken at different depth. The results of these both methods vary; moreover, heterogeneity in the subsurface may cause an even greater variability of this relationship. For the calculation an "average" function was applied. The third obstacle: The pore water conductivity may change during the infiltration due to exchange of pore water. This effect is neglected for this experiment on account of the very similar resistivity of original pore water and infiltrated water. This effect, however, is of great importance if saline water is used for infiltration experiments. It will also hamper the quantitative interpretation if solution and precipitation processes within the soil during the infiltration are expected. The fourth obstacle: The disadvantageous shape of the function relating resistivity and water content. Unfortunately at high water contents only very little change in resistivity is observed if the water content increases or decreases, the function is steep only at small and medium water contents but very flat at high water contents. We conclude from the combination of these four obstacles that quantitative interpretation of recharge with ERT is possible only in fortunate cases. ERT can enable us to actually measure recharge processes. However, if the conditions are not fortunate, the interpretation of the ERT data will permit the conclusion whether there is recharge. The quantitative value will remain doubtful if no additional measurements are taken that narrow the uncertainties. Particularly TDR/resistivity measurements with the same probe are helpful to get the information about the mixing of the pore water.

  2. Modelling of groundwater recharge and drought statistics within the framework of a climate impact study in a Mediterranean catchment (Thau Lagoon, France)

    NASA Astrophysics Data System (ADS)

    Herrmann, Frank; Baghdadi, Nicolas; Deidda, Roberto; La Jeunesse, Isabelle; Ludwig, Ralf; Sellami, Haykel; Vereecken, Harry; Wendland, Frank

    2014-05-01

    According to current climate projections until the year 2100, Mediterranean countries are likely to be at high risk for decreasing groundwater recharge during the hydrological winter half year as well as increasing drought severity and duration during summer. Thus, the irrigation needs of agricultural land might increase during the vegetation period and will have to be covered regionally specific partially from groundwater resources. This issue seems to be equally important to be investigated compared to the possible future change of the river discharge regime under changed climate conditions. Within the framework of the EU-founded CLIMB project (Climate Induced Changes on the Hydrology of Mediterranean Basins) the water balance model mGROWA (Herrmann, 2013) was applied in order to simulate the water balance within the Thau Lagoon catchment (France) under present and possible future climate conditions. The model was originally developed in order to simulate actual evapotranspiration and runoff components (e.g. groundwater recharge) in daily time-steps and with high spatial resolution (50 m grid). Area-differentiated groundwater recharge and soil water content can be simulated consistently using mGROWA because of an integrated multi-layer soil water module. In the framework of CLIMB, this module has been extended by routines to calculate drought statistics. The mGROWA-model will be briefly introduced and its application to the Thau Lagoon catchment will be presented. At first water balance was simulated for the reference period (1995-2010) based on observed climate data. Special attention will be paid to the simulated temporal variable water content in the root zone and thus to percolation water fluxes and drought statistics. Second, a possible bandwidth of future groundwater recharge (until 2070) is forecasted using climate data from a Regional-Climate-Modell-ensemble (RCM; Deidda, 2013). Three of the four RCM-mGROWA combinations indicate decreasing groundwater recharge up to 25 mm/a until 2070 compared to the reference period 1971-2000, whereas one RCM-mGROWA combination projects a nearly constant level of groundwater recharge for the future. The calculated drought indices however indicate that the frequency and duration of droughts will increase until 2070. References: Deidda R., M. Marrocu, G. Caroletti, G. Pusceddu, A. Langousis, V. Lucarini, M. Puliga, and A. Speranza (2013), Regional climate models' performance in representing precipitation and temperature over selected Mediterranean areas, Hydrology and Earth System Sciences, 17, 5041-5059, doi:10.5194/hess-17-5041-2013 Herrmann, F., Chen, S., Heidt, L., Elbracht, J., Engel, N., Kunkel, R., Müller, U., Röhm, H., Vereecken, H., Wendland, F., 2013. Zeitlich und räumlich hochaufgelöste flächendifferenzierte Simulation des Landschaftswasserhaushalts in Niedersachsen mit dem Model mGROWA. Hydrologie und Wasserbewirtschaftung, 57(5): 206-224.

  3. Removal of organic micropollutants in an artificial recharge system

    NASA Astrophysics Data System (ADS)

    Valhondo, C.; Nödler, K.; Köck-Schulmeyer, M.; Hernandez, M.; Licha, T.; Ayora, C.; Carrera, J.

    2012-04-01

    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 Vicenç 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.

  4. Feasibility and potential effects of the proposed Amargosa Creek Recharge Project, Palmdale, California

    USGS Publications Warehouse

    Christensen, Allen H.; Siade, Adam J.; Martin, Peter; Langenheim, V.E.; Catchings, Rufus D.; Burgess, Matthew K.

    2015-01-01

    The hydraulic conductivities of faults were estimated on the basis of water-level data and an estimate of natural recharge along Amargosa Creek. With assumed horizontal hydraulic conductivities of 10 and 100 feet per day in the upper 150 feet, the simulated maximum artificial recharge rates to the regional flow system at the ACRP were 3,400 and 9,400 acre-feet per year, respectively. These maximum recharge rates were limited primarily by the horizontal hydraulic conductivity in the upper 150 feet and by the liquefaction constraint. Future monitoring of water-level and soil-water content changes during the proposed project would allow improved estimation of aquifer hydraulic properties, the effect of the faults on groundwater movement, and the overall recharge capacity of the ACRP.

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

    PubMed Central

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

    2014-01-01

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

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

    SciTech Connect

    Fayer, Michael J.; Szecsody, Jim E.

    2004-06-30

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

  7. Groundwater recharge and age-depth profiles of intensively exploited groundwater resources in northwest India

    NASA Astrophysics Data System (ADS)

    Lapworth, D. J.; MacDonald, A. M.; Krishan, G.; Rao, M. S.; Gooddy, D. C.; Darling, W. G.

    2015-09-01

    Intensive irrigation in northwest India has led to growing concerns over the sustainability of current and future groundwater abstraction. Environmental tracers and measurements of groundwater residence times can help quantify the renewal processes. Results from 16 paired locations show the interquartile ranges for residence times in shallow alluvial groundwater (8-50 m deep) to be 1-50 years and significantly less than those from deeper groundwater (76-160 m deep) at 40-170 years. The widespread occurrence of modern tracers in deep groundwater (>60% of sites had >10% modern recharge) suggests that there is low regional aquifer anisotropy and that deep aquifers are recharged by a significant component of recent recharge via vertical leakage. Stable isotope and noble gas results at all depths conform to modern meteoric sources and annual average temperatures, with no evidence of significant regional recharge from canal leakage in this study area close to the Himalayas.

  8. Tracing Recharge from Sinking Streams over Spatial Dimensions of Kilometers in a Karst Aquifer

    USGS Publications Warehouse

    Greene, E.A.

    1997-01-01

    Stable isotopes of hydrogen and oxygen were used to trace the sources of recharge from sinking streams to wells and springs several kilometers downgradient in the karst Madison aquifer near Rapid City, South Dakota. Temporal sampling of streamflow above the swallets identified a distinct isotopic signature that was used to define the spatial dimensions of recharge to the aquifer. When more than one sinking stream was determined to be recharging a well or spring, the proportions were approximated using a two-component mixing model. From the isotopic analysis, it is possible to link sinking stream recharge to individual wells or springs in the Rapid City area and illustrate there is significant lateral movement of ground water across surface drainage basins. These results emphasize that well-head protection strategies developed for carbonate aquifers that provide industrial and municipal water supplies need to consider lateral movement of ground-water flow from adjacent surface drainage basins.

  9. Electrically recharged battery employing a packed/spouted bed metal particle electrode

    DOEpatents

    Siu, Stanley C. (Alameda, CA); Evans, James W. (Piedmont, CA); Salas-Morales, Juan (Berkeley, CA)

    1995-01-01

    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.

  10. A novel electrolyte system without a Grignard reagent for rechargeable magnesium batteries.

    PubMed

    Wang, Fei-fei; Guo, Yong-sheng; Yang, Jun; Nuli, Yanna; Hirano, Shin-ichi

    2012-11-11

    A new phenolate-based magnesium ion conducting electrolyte is prepared. The electrolyte exhibits air insensitive character and excellent electrochemical performances which make it highly promising for advanced rechargeable Mg battery systems. PMID:23019571

  11. 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...

  12. 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...

  13. The Morgan Recharger: a new horn fly (Diptera: Muscidae) control device for beef cattle.

    PubMed

    Barton, W E; Gray, E W; Noblet, R; Thompson, C E

    1990-08-01

    A 20% diazinon formulation was evaluated for control efficacy against the horn fly, Haematobia irritans (L.), in the Morgan Recharger (Morgan International Products, College Grove, Tenn.). The Morgan Recharger releases insecticide with a wicking system from an insecticide reservoir and can be attached to an animal's ear or tail. This device was most effective against the horn fly when used as an ear tag with two per head; horn fly counts did not exceed five flies per side through 8 wk. The diazinon formulation tested was released from the Morgan Recharger at a decreasing rate. The problems and potential of the Morgan Recharger as an effective horn fly control device are discussed. PMID:2212237

  14. A water-budget model and estimates of groundwater recharge for Guam

    USGS Publications Warehouse

    Johnson, Adam G.

    2012-01-01

    On Guam, demand for groundwater tripled from the early 1970s to 2010. The demand for groundwater is anticipated to further increase in the near future because of population growth and a proposed military relocation to Guam. Uncertainty regarding the availability of groundwater resources to support the increased demand has prompted an investigation of groundwater recharge on Guam using the most current data and accepted methods. For this investigation, a daily water-budget model was developed and used to estimate mean recharge for various land-cover and rainfall conditions. Recharge was also estimated for part of the island using the chloride mass-balance method. Using the daily water-budget model, estimated mean annual recharge on Guam is 394.1 million gallons per day, which is 39 percent of mean annual rainfall (999.0 million gallons per day). Although minor in comparison to rainfall on the island, water inflows from water-main leakage, septic-system leachate, and stormwater runoff may be several times greater than rainfall at areas that receive these inflows. Recharge is highest in areas that are underlain by limestone, where recharge is typically between 40 and 60 percent of total water inflow. Recharge is relatively high in areas that receive stormwater runoff from storm-drain systems, but is relatively low in urbanized areas where stormwater runoff is routed to the ocean or to other areas. In most of the volcanic uplands in southern Guam where runoff is substantial, recharge is less than 30 percent of total water inflow. The water-budget model in this study differs from all previous water-budget investigations on Guam by directly accounting for canopy evaporation in forested areas, quantifying the evapotranspiration rate of each land-cover type, and accounting for evaporation from impervious areas. For the northern groundwater subbasins defined in Camp, Dresser & McKee Inc. (1982), mean annual baseline recharge computed in this study is 159.1 million gallons per day, which is 50 percent of mean annual rainfall, and is 42 percent greater than the recharge estimate of Camp, Dresser & McKee Inc. (1982). For the northern aquifer sectors defined in Mink (1991), which encompass most of the northern half of the island, mean annual baseline recharge computed in this study is 238.0 million gallons per day, which is 51 percent of mean annual rainfall, and is about 6 percent lower than the recharge estimate of Mink (1991). For the drought simulation performed in this study, recharge for the entire island is 259.3 million gallons per day, which is 34 percent lower than recharge computed for baseline conditions. For all aquifer sectors defined by Mink (1991), total recharge during drought conditions is 32 percent lower than mean baseline recharge. For the future land-cover water-budget simulation, which represents potential land-cover changes owing to the military relocation and population growth, estimated recharge for the entire island is nearly equal to the baseline recharge estimate that was based on 2004 land cover. Using the water-budget model, estimated recharge in the northern half of the island is most sensitive to crop coefficients and net precipitation rates—two of the water-budget parameters used in the estimation of total evapotranspiration. Estimated recharge in the southern half of the island is most sensitive to crop coefficients, net precipitation rate, and runoff-to-rainfall ratios. During March 2010 to May 2011, bulk-deposition samples from five rainfall stations on Guam were collected and analyzed for chloride. Additionally, samples from five groundwater sites were collected and analyzed for chloride. Results were used to estimate groundwater recharge using the chloride mass-balance method. Recharge estimates using this method at three bulk-deposition stations on the northern limestone plateau range from about 25 to 48 percent of rainfall. These recharge estimates are similar to the estimate of Ayers (1981) who also used this method. Recharge estimates at each bulk-deposition station, however, are lower than the baseline recharge estimate from the water-budget model used in this study. This may be because no large storms, such as tropical cyclones, passed near Guam during March 2010 to May 2011.

  15. Heat flux from magmatic hydrothermal systems related to availability of fluid recharge

    NASA Astrophysics Data System (ADS)

    Harvey, M. C.; Rowland, J. V.; Chiodini, G.; Rissmann, C. F.; Bloomberg, S.; Hernández, P. A.; Mazot, A.; Viveiros, F.; Werner, C.

    2015-09-01

    Magmatic hydrothermal systems are of increasing interest as a renewable energy source. Surface heat flux indicates system resource potential, and can be inferred from soil CO2 flux measurements and fumarole gas chemistry. Here we compile and reanalyze results from previous CO2 flux surveys worldwide to compare heat flux from a variety of magma-hydrothermal areas. We infer that availability of water to recharge magmatic hydrothermal systems is correlated with heat flux. Recharge availability is in turn governed by permeability, structure, lithology, rainfall, topography, and perhaps unsurprisingly, proximity to a large supply of water such as the ocean. The relationship between recharge and heat flux interpreted by this study is consistent with recent numerical modeling that relates hydrothermal system heat output to rainfall catchment area. This result highlights the importance of