WorldWideScience

Sample records for fluctuating water levels

  1. Vegetational and landscape level responses to water level fluctuations in Finnish, mid-boreal aapa mire - aro wetland environments

    Energy Technology Data Exchange (ETDEWEB)

    Laitinen, J.

    2008-07-01

    Abstract Gradient, which is largely considered to be related to water level in mires, is referred to as a microtopographic mud bottom to carpet to lawn to hummock level gradient or the hummock level to intermediate level (lawn) to flark level gradient. The relationship of this vegetation gradient to various physical water level characteristics was studied. The general classification used in the present summary paper divides the aro vegetation of the inland of Northern Ostrobothnia into two main groups: (a) treeless fen aro vegetation (Juncus supinus, Carex lasiocarpa, Rhynchospora fusca, Molinia caerulea) and (b) heath aro vegetation (Polytrichum commune). The first group (a) was divided into fen aro wetlands with an approximately10 cm peaty layer at most and into aro fens with a peat layer thicker than 10 cm. The treatment of the water level gradient was divided into three main groups. (1) The mean water level correlated with mire surface levels (microtopographic gradient) within mires with slight water level fluctuations and partly within mires with considerable water level fluctuations. (2) Three habitat groups could be distinguished on the basis of the range of water level fluctuation i.e. mires with slight water level fluctuations, mires with considerable water level fluctuations and the aro vegetation with extreme water level fluctuations. (3) The timing of water level fluctuations indicated that there are different types of patterns within aro wetlands, the seasonal pattern being mainly a response to yearly snow melt and the several-year-fluctuation pattern being related to the regional groundwater table fluctuation in mineral soils (heath forests). A link was suggested between the stability of the water regime and peat production in local aapa mire - aro wetland environments. From the point of view of peatland plants the direction of variation from a stable to an unstable water regime in aapa mire - aro wetland environments represents a transition towards more and more harsh ecological conditions, partly forming a gradient through natural disturbance. A qualitative functional model was provided for the mire - aro wetland systems of Northern Ostrobothnia. The model supposes differences in the characteristics of peat between two functional complexes within a mire system. Finally, the model for local mire - aro wetland systems was converted to a general from: diplotelmic (acrotelm) mires were divided into two subtypes (diplotelmic water stabilization mires, diplotelmic water fluctuation mires) and the relationship of those subtypes to percolation mires and seasonal wetlands was considered. (orig.)

  2. Analysis of environmental issues related to small-scale hydroelectric development. III. Water level fluctuation

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrand, S.G. (ed.)

    1980-10-01

    Potential environmental impacts in reservoirs and downstream river reaches below dams that may be caused by the water level fluctuation resulting from development and operation of small scale (under 25MW) hydroelectric projects are identified. The impacts discussed will be of potential concern at only those small-scale hydroelectric projects that are operated in a store and release (peaking) mode. Potential impacts on physical and chemical characteristics in reservoirs resulting from water level fluctuation include resuspension and redistribution of bank and bed sediment; leaching of soluble organic matter from sediment in the littoral zone; and changes in water quality resulting from changes in sediment and nutrient trap efficiency. Potential impacts on reservoir biota as a result of water level fluctuation include habitat destruction and the resulting partial or total loss of aquatic species; changes in habitat quality, which result in reduced standing crop and production of aquatic biota; and possible shifts in species diversity. The potential physical effects of water level fluctuation on downstream systems below dams are streambed and bank erosion and water quality problems related to resuspension and redistribution of these materials. Potential biological impacts of water level fluctuation on downstream systems below dams result from changes in current velocity, habitat reduction, and alteration in food supply. These alterations, either singly or in combination, can adversely affect aquatic populations below dams. The nature and potential significance of adverse impacts resulting from water level fluctuation are discussed. Recommendations for site-specific evaluation of water level fluctuation at small-scale hydroelectric projects are presented.

  3. Water level fluctuations due to earth tides in a well pumping from slightly fractured crystalline rock

    International Nuclear Information System (INIS)

    J At the Savannah River plant of the Atomic Energy Commission near Aiken, South Carolina, there are three distinct groundwater systems: the coastal plain sediments, the crystalline metamorphic rocks, and a buried Triassic basin. The coastal plain sediments include several Cretaceous and Tertiary granular aquifers and aquicludes, the total thickness being about 305 m. Below these sediments, water occurs in small fractures in crystalline metamorphic rock (hornblende schist and gneiss with lesser amounts of quartzite). Water level fluctuations due to earth tides are recorded in the crystalline metamorphic rock system and in the coastal plain sediments. No water level fluctuations due to earth tides have been observed in wells in the Triassic rock because of the very low permeability. The water level fluctuations due to earth tides in the crystalline rock are about 10 cm, and those in the sediments are about 1.8 cm. The use of water level fluctuations due to earth tides to calculate porosity appears to present practical difficulties both in the crystalline metamorphic rock system and in the coastal plain sediments. In a 1-yr pumping test on a well in the crystalline metamorphic rock the flow was controlled to within 0.1 percent of the total discharge, which was 0.94 1/s. The water level fluctuations due to earth tides in the pumping well were 10 cm, the same as when this well was not being pumped. (U.S.)

  4. Earthquake-induced water-level fluctuations at Yucca Mountain, Nevada, June 1992

    International Nuclear Information System (INIS)

    This report presents earthquake-induced water-level and fluid-pressure data for wells in the Yucca Mountain area, Nevada, during June 1992. Three earthquakes occurred which caused significant water-level and fluid-pressure responses in wells. Wells USW H-5 and USW H-6 are continuously monitored to detect short-term responses caused by earthquakes. Two wells, monitored hourly, had significant, longer-term responses in water level following the earthquakes. On June 28, 1992, a 7.5-magnitude earthquake occurred near Landers, California causing an estimated maximum water-level change of 90 centimeters in well USW H-5. Three hours later a 6.6-magnitude earthquake occurred near Big Bear Lake, California; the maximum water-level fluctuation was 20 centimeters in well USW H-5. A 5.6-magnitude earthquake occurred at Little Skull Mountain, Nevada, on June 29, approximately 23 kilometers from Yucca Mountain. The maximum estimated short-term water-level fluctuation from the Little Skull Mountain earthquake was 40 centimeters in well USW H-5. The water level in well UE-25p number-sign 1, monitored hourly, decreased approximately 50 centimeters over 3 days following the Little Skull Mountain earthquake. The water level in UE-25p number-sign 1 returned to pre-earthquake levels in approximately 6 months. The water level in the lower interval of well USW H-3 increased 28 centimeters following the Little Skull Mountain earthquake. The Landers and Little Skull Mountain earthquakes caused responses in 17 intervals of 14 hourly monitored wells, however, most responses were small and of short duration. For several days following the major earthquakes, many smaller magnitude aftershocks occurred causing measurable responses in the continuously monitored wells

  5. Measuring Water Level Fluctuations of two Connected Wetlands in the Dominican Republic Using InSAR

    Science.gov (United States)

    Pichardo Marcano, M. D.; Liu, L.; Zebker, H. A.

    2012-12-01

    Wetlands are ecosystems of high endemism and great biodiversity. Using the double-reflected radar waves off the water surface and trunks of inundated vegetation, Interferometric Synthetic Aperture Radar (InSAR) is capable of measuring water level fluctuations from space at a cm-level accuracy in these ecosystems with emergent vegetation. InSAR can provide a high spatial resolution over a large area that the more traditional terrestrial-based methods lack. In this study, we applied InSAR to study the seasonal variations in water level of the wetlands near two lakes in the southwest of the Dominican Republic: Lake Enriquillo, a highly saline lake designated as a Wetland of International Importance under the Ramsar Convention in 2002, and Laguna del Limon. Both lake-wetland systems are located in the Jaragua-Bahoruco-Enriquillo Biosphere Reserve. Since 2003 the water level of Lake Enriquillo has increased drastically and caused the evacuation of many farmers from nearby villages. Lake level changes also affected the habitats of several native and migratory species. We used the data acquired by the Phased Array type L-band Synthetic Aperture Radar (PALSAR) sensor on board of the Japanese Advanced Land Observation Satellite (ALOS) from October 2008 to January 2011. For the smaller lake, Laguna del Limon, we found a seasonal variation of 10-15 centimeters. This result was confirmed using two different satellite paths. For Lake Enriquillo we found a net decrease of about 20 centimeters in the water level from September 2009 to January 2011. This result agrees with an independent estimation based on lake hydrodynamics model predictions. In addition, our InSAR-based time series of lake level fluctuations revealed distinct behaviors of the two wetlands. For the Lake Enriquillo we found a continuous decrease in the water level throughout 2010 with a brief increase of the water level during the summer months, while for Laguna del Limon during the summer months the water level decreased and the lake presented a net increase in the water level. The decrease in water level for Lake Enriquillo can be explained by the reduce precipitation rate in 2010 compared to previous years. We demonstrate that InSAR is an effective way to measure water level fluctuations at wetlands in this region. The same method could be applied to other wetlands in the area to fully understand the complex hydrology of the connected wetland systems and the impacts of the hydrological changes on the environment and local human community.

  6. Response of littoral macrophytes to water level fluctuations in a storage reservoir

    Directory of Open Access Journals (Sweden)

    Krolová M.

    2013-05-01

    Full Text Available Lakes and reservoirs that are used for water supply and/or flow regulations have usually poorly developed littoral macrophyte communities, which impairs ecological potential in terms of the EU Water Framework Directive. The aim of our study was to reveal controlling factors for the growth of littoral macrophytes in a storage reservoir with fluctuating water level (Lipno Reservoir, Czech Republic. Macrophytes occurred in this reservoir only in the eulittoral zone i.e., the shoreline region between the highest and the lowest seasonal water levels. Three eulittoral sub-zones could be distinguished: the upper eulittoral with a stable community of perennial species with high cover, the middle eulittoral with relatively high richness of emergent and amphibious species present at low cover values, and the lower eulittoral devoid of permanent vegetation. Cover and species composition in particular sub-zones were primarily influenced by the duration and timing of flooding, followed by nutrient limitation and strongly reducing conditions in the flooded organic sediment. Our results stress the ecological importance of eulittoral zone in reservoirs with fluctuating water levels where macrophyte growth can be supported by targeted management of water level, thus helping reservoir managers in improving the ecological potential of this type of water bodies.

  7. Establishment of earth tides effect on water level fluctuations in an unconfined hard rock aquifer using spectral analysis

    CERN Document Server

    Maréchal, Jean-Christophe; Ahmed, Shakeel; Lachassagne, Patrick

    2010-01-01

    Short-interval water level measurements using automatic water level recorder in a deep well in an unconfined crystalline rock aquifer at the campus of NGRI, near Hyderabad shows a cyclic fluctuation in the water levels. The observed values clearly show the principal trend due to rainfall recharge. Spectral analysis was carried out to evaluate correlation of the cyclic fluctuation to the synthetic earth tides as well as groundwater withdrawal time series in the surrounding. It was found that these fluctuations have considerably high correlation with earth tides whereas groundwater pumping does not show any significant correlation with water table fluctuations. It is concluded that earth tides cause the fluctuation in the water table. These fluctuations were hitherto unobserved during manual observations made over larger time intervals. It indicates that the unconfined aquifer is characterised by a low porosity.

  8. Water-level fluctuations, emersion regimes, and variations of echinoid populations on a Caribbean reef flat

    Science.gov (United States)

    Cubit, John D.; Windsor, Donald M.; Thompson, Ricardo C.; Burgett, Jeff M.

    1986-06-01

    This paper examines fluctuations in water level over a Caribbean reef flat at Punta Galeta, Panamá. In an analysis of approximately ten years of records, the mean diurnal range of the tides was 24·5 cm and varied Lytechinus variegatus and Diadema antillarum declined or disappeared from the reef flat during seasons of repeated subaerial exposures, but recolonized the habitat in periods of higher water levels. Although they are reported to suffer heavy mortality during emersion, Echinometra lucunter and E. viridis did not exhibit reductions in abundance that were synchronous with the seasonal exposures of the reef flat.

  9. Simulation of Water Level Fluctuations in a Hydraulic System Using a Coupled Liquid-Gas Model

    Directory of Open Access Journals (Sweden)

    Chao Wang

    2015-08-01

    Full Text Available A model for simulating vertical water level fluctuations with coupled liquid and gas phases is presented. The Preissmann implicit scheme is used to linearize the governing equations for one-dimensional transient flow for both liquid and gas phases, and the linear system is solved using the chasing method. Some classical cases for single liquid and gas phase transients in pipelines and networks are studied to verify that the proposed methods are accurate and reliable. The implicit scheme is extended using a dynamic mesh to simulate the water level fluctuations in a U-tube and an open surge tank without consideration of the gas phase. Methods of coupling liquid and gas phases are presented and used for studying the transient process and interaction between the phases, for gas phase limited in a chamber and gas phase transported in a pipeline. In particular, two other simplified models, one neglecting the effect of the gas phase on the liquid phase and the other one coupling the liquid and gas phases asynchronously, are proposed. The numerical results indicate that the asynchronous model performs better, and are finally applied to a hydropower station with surge tanks and air shafts to simulate the water level fluctuations and air speed.

  10. Response of littoral macrophytes to water level fluctuations in a storage reservoir.

    Czech Academy of Sciences Publication Activity Database

    Krolová, Monika; ?ížková, Hana; Hejzlar, Josef; Poláková, S.

    2013-01-01

    Ro?. 408, May (2013), 07p1-07p21. ISSN 1961-9502 R&D Projects: GA ?R(CZ) GA206/09/1764; GA MŠk(CZ) 7E11059 Grant ostatní: EC ENV(CZ) FP7 244121 Institutional research plan: CEZ:AV0Z60170517 Institutional support: RVO:60077344 ; RVO:67179843 Keywords : littoral macrophytes * eulittoral * water level fluctuation * European Water Framework Directive * ecophases Subject RIV: DA - Hydrology ; Limnology Impact factor: 0.622, year: 2013

  11. Sediment size distribution and composition in a reservoir affected by severe water level fluctuations.

    Science.gov (United States)

    López, Pilar; López-Tarazón, José A; Casas-Ruiz, Joan P; Pompeo, Marcelo; Ordoñez, Jaime; Muñoz, Isabel

    2016-01-01

    The reservoir sediments are important sinks for organic carbon (OC), the OC burial being dependent on two opposite processes, deposition and mineralization. Hence factors such as severe water level fluctuations are expected to influence the rate of OC accumulation as they may affect both deposition and mineralization. The Barasona Reservoir has been historically threatened by siltation, whilst the use of water for irrigation involves a drastic decrease of the water level. In this context, we have studied the physical and chemical characteristics (grain size, major and minor elemental compositions, organic and inorganic carbon, and nitrogen) of the recent sediments of the Barasona Reservoir and the relationships among them in order to: a) elucidate the main processes governing OC accumulation, b) evaluate the rate of OC mineralization and c) approach the effect of drought on the sediment characteristics in this system. Our results indicated that Barasona sediments were dominated by fine silts (>60%) and clays (>20%), the mean particle size decreasing from tail to dam. Desiccation increased particle sorting and size distribution became bimodal, but no effect on average size was observed. Attending to the composition, Barasona sediments were very homogeneous with low concentrations of nitrogen (TN) and phosphorus (carbon, major ions and grain size. The high amount of OC deposited in Barasona sediment suggested that the adsorption of OC onto fine particles was more important than in boreal lakes. The rate of oxygen consumption by wet sediment ranged from 2.26 to 3.15mgO2m(-2)day(-1), values close to those compiled for Mediterranean running waters. PMID:26105704

  12. Effects of fluctuations in river water level on virus removal by bank filtration and aquifer passage — A scenario analysis

    Science.gov (United States)

    Derx, J.; Blaschke, A. P.; Farnleitner, A. H.; Pang, L.; Blöschl, G.; Schijven, J. F.

    2013-04-01

    Riverbank filtration is an effective process for removing pathogenic viruses from river water. Despite indications that changing hydraulic conditions during floods can affect the efficacy of riverbank filtration to remove viruses, the impact on advection and dispersion of viruses in the riverbank is not well understood. We investigated the effects of fluctuations in river water level on virus transport during riverbank filtration, considering 3-D transient groundwater flow and virus transport. Using constant removal rates from published field experiments with bacteriophages, removal of viruses with distance from the riverbank was simulated for coarse gravel, fine gravel and fine sandy gravel. Our simulations showed that, in comparison with steady flow conditions, fluctuations in river water level cause viruses to be transported further at higher concentrations into the riverbank. A 1-5 m increase in river water levels led to a 2- to 4-log (log10 reduction in concentration relative to the initial concentration in the river) increase in virus concentration and to up to 30 % shorter travel times. For particular cases during the receding flood, changing groundwater flow conditions caused that pristine groundwater was carried from further inland and that simulated virus concentrations were more diluted in groundwater. Our study suggests that the adverse effect of water level fluctuations on virus transport should be considered in the simulation of safe setback distances for drinking water supplies.

  13. Effects of fluctuations in river water level on virus removal by bank filtration and aquifer passage--a scenario analysis.

    Science.gov (United States)

    Derx, J; Blaschke, A P; Farnleitner, A H; Pang, L; Blöschl, G; Schijven, J F

    2013-04-01

    Riverbank filtration is an effective process for removing pathogenic viruses from river water. Despite indications that changing hydraulic conditions during floods can affect the efficacy of riverbank filtration to remove viruses, the impact on advection and dispersion of viruses in the riverbank is not well understood. We investigated the effects of fluctuations in river water level on virus transport during riverbank filtration, considering 3-D transient groundwater flow and virus transport. Using constant removal rates from published field experiments with bacteriophages, removal of viruses with distance from the riverbank was simulated for coarse gravel, fine gravel and fine sandy gravel. Our simulations showed that, in comparison with steady flow conditions, fluctuations in river water level cause viruses to be transported further at higher concentrations into the riverbank. A 1-5 m increase in river water levels led to a 2- to 4-log (log10 reduction in concentration relative to the initial concentration in the river) increase in virus concentration and to up to 30% shorter travel times. For particular cases during the receding flood, changing groundwater flow conditions caused that pristine groundwater was carried from further inland and that simulated virus concentrations were more diluted in groundwater. Our study suggests that the adverse effect of water level fluctuations on virus transport should be considered in the simulation of safe setback distances for drinking water supplies. PMID:23500839

  14. Seepage flow-stability analysis of the riverbank of Saigon river due to river water level fluctuation

    CERN Document Server

    Oya, A; Hiraoka, N; Fujimoto, M; Fukagawa, R

    2015-01-01

    The Saigon River, which flows through the center of Ho Chi Minh City, is of critical importance for the development of the city as forms as the main water supply and drainage channel for the city. In recent years, riverbank erosion and failures have become more frequent along the Saigon River, causing flooding and damage to infrastructures near the river. A field investigation and numerical study has been undertaken by our research group to identify factors affecting the riverbank failure. In this paper, field investigation results obtained from multiple investigation points on the Saigon River are presented, followed by a comprehensive coupled finite element analysis of riverbank stability when subjected to river water level fluctuations. The river water level fluctuation has been identified as one of the main factors affecting the riverbank failure, i.e. removal of the balancing hydraulic forces acting on the riverbank during water drawdown.

  15. Combining the soilwater balance and water-level fluctuation methods to estimate natural groundwater recharge: Practical aspects

    Science.gov (United States)

    Sophocleous, M.A.

    1991-01-01

    A relatively simple and practical approach for calculating groundwater recharge in semiarid plain environments with a relatively shallow water table, such as the Kansas Prairies, is outlined. Major uncertainties in the Darcian, water balance, and groundwater fluctuation analysis approaches are outlined, and a combination methodology for reducing some of the uncertainties is proposed. By combining a storm-based soilwater balance (lasting several days) with the resulting water table rise, effective storativity values of the region near the water table are obtained. This combination method is termed the 'hybrid water-fluctuation method'. Using a simple average of several such estimates results in a site-calibrated effective storativity value that can be used to translate each major water-table rise tied to a specific storm period into a corresponding amount of groundwater recharge. Examples of soilwater balance and water-level fluctuation analyses based on field-measured data from Kansas show that the proposed methodology gives better and more reliable results than either of the two well-established approaches used singly. ?? 1991.

  16. Deep bore well water level fluctuations in the Koyna region, India: the presence of a low order dynamical system in a seismically active environment

    Directory of Open Access Journals (Sweden)

    D. V. Ramana

    2009-05-01

    Full Text Available Water level fluctuations in deep bore wells in the vicinity of seismically active Koyna region in western India provides an opportunity to understand the causative mechanism underlying reservoir-triggered earthquakes. As the crustal porous rocks behave nonlinearly, their characteristics can be obtained by analysing water level fluctuations, which reflect an integrated response of the medium. A Fractal dimension is one such measure of nonlinear characteristics of porous rock as observed in water level data from the Koyna region. It is inferred in our study that a low nonlinear dynamical system with three variables can predict the water level fluctuations in bore wells.

  17. Predicted Changes in Interannual Water-Level Fluctuations Due to Climate Change and Its Implications for the Vegetation of the Florida Everglades

    Science.gov (United States)

    van der Valk, Arnold G.; Volin, John C.; Wetzel, Paul R.

    2015-04-01

    The number of dominant vegetation types (wet prairies, sawgrass flats, ridges and sloughs, sloughs, and tree islands) historically and currently found in the Everglades, FL, USA, as with other wetlands with standing water, appears to be primarily a function of the magnitude of interannual water-level fluctuations. Analyses of 40 years of water-depth data were used to estimate the magnitude of contemporary (baseline) water-level fluctuations in undisturbed ridge and slough landscapes. Baseline interannual water-level fluctuations above the soil surface were at least 1.5 m. Predicted changes in interannual water-level fluctuations in 2060 were examined for seven climate change scenarios. When rainfall is predicted to increase by 10 %, the wettest scenario, the interannual range of water-level fluctuation increases to 1.8 m above the soil surface in sloughs. When rainfall is predicted to decrease by 10 % and temperatures to increase by 1.5 °C, the driest scenario, the range of interannual range of water-level fluctuations is predicted to decrease to 1.2 m above the soil surface in sloughs. A change of 25-30 cm in interannual water-level fluctuations is needed to change the number of vegetation types in a wetland. This suggests that the two most extreme climate change scenarios could have a significant impact on the overall structure of wetland vegetation, i.e., the number of vegetation types or zones, found in the Everglades.

  18. Community metabolism in a deep (stratified) tropical reservoir during a period of high water-level fluctuations

    OpenAIRE

    Valdespino-Castillo, Patricia M.; Merino-Ibarra, Martín; Jiménez-Contreras, Jorge; Castillo-Sandoval, Fermín S.; Ramírez-Zierold, Jorge A.

    2014-01-01

    As long as lakes and reservoirs are an important component of the global carbon cycle, monitoring of their metabolism is required, especially in the tropics. In particular, the response of deep reservoirs to water-level fluctuations (WLF) is an understudied field. Here, we study community metabolism through oxygen dynamics in a deep monomictic reservoir where high WLF (~10 m) have recently occurred. Simultaneous monitoring of environmental variables and zooplankton dynamics was used to assess...

  19. Seepage Analysis of Rock-Fill Dam Subjected to Water Level Fluctuation: A case study on Gotvand-Olya Dam

    Directory of Open Access Journals (Sweden)

    Ali Beheshti

    2013-01-01

    Full Text Available The Gotvand-Olya Dam is a rock-fill dam, located at Khuzestan province in southwest of Iran. Since the dam is subjected to the daily water level fluctuation, such as rapid drawdown and refill, thus induce a structural impact on the behavior of dam body, it draws many soil engineering concerns. In this paper, seepage analysis of the rock-fill dam was primarily conducted to evaluate the dam safety against the leakage through the dam body. Traditionally, steady-state analysis was employed to investigate the seepage in the dam body, summing that water level is fixed at two cases: high and low water levels. Consequently, it was not able to properly reflect the time-dependent characteristics of seepage phenomena. In this study, seepage analysis was numerically performed using 2-D FEM transient analysis. As a particular boundary condition for an analysis, the water level fluctuation was incorporated to simulate the daily changes. As a result, various seepage phenomena were quantified such as hydraulic gradient, seepage vector and pore water pressure distribution at the corresponding time of interest as the water level rises and recedes. At steady state analysis, the seepage flux at high water level in downstream area was predicted to be 78 l/s. In additions, the seepage flux measured and estimated were both acceptable considering design criteria. The result of this study proves that there is no sign of hazardous sources contributing to the possibility of piping, internal erosion and excess leakage through the dam body.

  20. Wetland Ecohydrology: stochastic description of water level fluctuations across the soil surface

    Science.gov (United States)

    Tamea, S.; Muneepeerakul, R.; Laio, F.; Ridolfi, L.; Rodriguez-Iturbe, I.

    2009-12-01

    Wetlands provide a suite of social and ecological critical functions such as being habitats of disease-carrying vectors, providing buffer zones against hurricanes, controlling sediment transport, filtering nutrients and contaminants, and a repository of great biological diversity. More recently, wetlands have also been recognized as crucial for carbon storage in the context of global climate change. Despite such importance, quantitative approaches to many aspects of wetlands are far from adequate. Therefore, improving our quantitative understanding of wetlands is necessary to our ability to maintain, manage, and restore these invaluable environments. In wetlands, hydrologic factors and ecosystem processes interplay and generate unique characteristics and a delicate balance between biotic and abiotic elements. The main hydrologic driver of wetland ecosystems is the position of the water level that, being above or below ground, determines the submergence or exposure of soil. When the water level is above the soil surface, soil saturation and lack of oxygen causes hypoxia, anaerobic functioning of microorganisms and anoxic stress in plants, that might lead to the death of non-adapted organisms. When the water level lies below the soil surface, the ecosystem becomes groundwater-dependent, and pedological and physiological aspects play their role in the soil water balance. We propose here a quantitative description of wetland ecohydrology, through a stochastic process-based water balance, driven by a marked compound Poisson noise representing rainfall events. The model includes processes such as rainfall infiltration, evapotranspiration, capillary rise, and the contribution of external water bodies, which are quantified in a simple yet realistic way. The semi-analytical steady-state probability distributions of water level spanning across the soil surface are validated with data from the Everglades (Florida, USA). The model and its results allow for a quantitative analysis of the long term behavior of biotic and abiotic factors which depend on the position of the water level and enable the assessment of impacts of climate changes on the wetland ecosystem.

  1. Environmental factors associated with phytoplankton succession in a Mediterranean reservoir with a highly fluctuating water level.

    Science.gov (United States)

    Fadel, Ali; Atoui, Ali; Lemaire, Bruno J; Vinçon-Leite, Brigitte; Slim, Kamal

    2015-10-01

    Eutrophication and harmful algal blooms have become a worldwide environmental problem. Understanding the mechanisms and processes that control algal blooms is of great concern. The phytoplankton community of Karaoun Reservoir, the largest water body in Lebanon, is poorly studied, as in many freshwater bodies around the Mediterranean Sea. Sampling campaigns were conducted semi-monthly between May 2012 and August 2013 to assess the dynamics of its phytoplankton community in response to changes in physical-chemical and hydrological conditions. Karaoun Reservoir is a monomictic waterbody and strongly stratifies between May and August. Changes in its phytoplankton community were found to be a result of the interplay between water temperature, stratification, irradiance, nutrient availability and water level. Thermal stratification established in spring reduced the growth of diatoms and resulted in their replacement by green algae species when nutrient availability was high and water temperatures lower than 22 °C. At water temperature higher than 25 °C and low nutrient concentrations in summer, blooms of the cyanobacterium Microcystis aeruginosa occurred. Despite different growth conditions in other lakes and reservoir, cyanobacterium Aphanizomenon ovalisporum dominated at temperatures lower than 23 °C in weakly stratified conditions in early autumn and dinoflagellate Ceratium hirundinella dominated in mixed conditions, at low light intensity and a water temperature of 19 °C in late autumn. We believe that the information presented in this paper will increase the knowledge about phytoplankton dynamics in the Mediterranean region and contribute to a safer usage of reservoir waters. PMID:26383738

  2. Dramatic water-level fluctuations in lakes under intense human impact: modelling the effect of vegetation, climate and hydrogeology

    Science.gov (United States)

    Vainu, M.

    2012-04-01

    Lakes form a highly important ecosystem in the glacial terrain of northern Europe and America, but their hydrology remains understudied. When the water-level of a lake drops significantly and rises again in a time span of half a century and the widespread explanation of the fluctuations seems insufficient, then it raises a question: how do different anthropogenic and natural processes actually affect the formation of a lakes' water body. The abovementioned scenario applies to three small closed-basin Estonian lakes (L. Ahnejärv, L. Kuradijärv and L. Martiska) analysed in the current study. These lakes suffered a major water-level drop (up to 3.8 m) between 1946 and 1987 and a major rise between 1987 and 2010, from 1 m (L. Ahnejärv) to 2.5 m (L. Kuradijärv). Decreasing and increasing groundwater abstraction near the lakes has been widely considered to be the only reason for the fluctuations. It is true that the most severe drop in the lake levels did occur after 1972 when groundwater abstraction for drinking water started in the vicinity of the lakes. However, the lake levels started to fall before the groundwater abstraction began and for the time being the lake levels have risen to a higher level than in the 1970s when the quantity of annually abstracted groundwater was similar to nowadays. Therefore the processes affecting the formation of the lakes' water body prove to be more complex than purely the hydrogeological change caused by groundwater abstraction. A new deterministic water balance model (where the evaporation from the lake surface was calculated by Penman equation and the catchment runoff by Thornthwaite-Mather soil-moisture model), compiled for the study, coupled with LiDAR-based GIS-modelling of the catchments was used to identify the different factors influencing the lakes' water level. The modelling results reveal that the moderate drop in lake water levels before the beginning of groundwater abstraction was probably caused by the growth of a coniferous forest on the lake catchments, due to which evapotranspiration and subsequently runoff from the catchment decreased. The forest had been destroyed by wildfires during World War II. The water-level rise that the lakes have gone through in the last 20 years has in the case of L. Ahnejärv been caused by changing meteorological conditions (precipitation, air temperature and wind speed). In the case of Lakes Kuradijärv and Martiska the change has been caused by both the raise of groundwater level (caused by the decreasing groundwater abstraction) and the change of meteorological conditions. Therefore the vegetation change on the catchment and changes in meteorological conditions have played as important or, at times, even more important role in the water-level fluctuations than changes in the hydrogeological conditions. Although concentrating on three specific lakes in a specific region, the result of the study indicate the complexity of factors influencing the amount of water stored in a lake at a certain moment. Therefore it manifests a need for improved models in order to improve lake management around the world.

  3. Response of Eichhornia crassipes (Pontederiaceae) to water level fluctuations in two lakes with different connectivity in the Paraná River floodplain

    Scientific Electronic Library Online (English)

    Juan José, Neiff; Sylvina Lorena, Casco; Alicia, Poi de Neiff.

    2008-06-01

    Full Text Available Se analiza la respuesta de Eichhornia crassipes, una de las plantas acuáticas más frecuentes en la planicie de inundación del río Paraná, a las fluctuaciones del río en dos lagos con diferente conectividad. Las muestras fueron tomadas en 13 condiciones hidrológicas entre Marzo de 1997 y Diciembre de [...] 2001. Durante el periodo de prolongada conectividad hidrológica, el área cubierta por el agua aumenta más de tres veces y el contenido de nitrógeno inorgánico disuelto fue mayor en comparación con la condición de prolongado aislamiento. En comparación con las plantas del lago más aislado del río, las del más conectado tuvieron significativamente menor densidad de hojas, hojas más largas, menor biomasa de raíces y menor cociente entre la biomasa de las partes aéreas y las partes sumergidas. Las diferencias en la altura y la biomasa de hojas y raíces entre diferentes condiciones hidrológicas y la no significativa relación entre el tamaño y su densidad, indican que las características morfológicas de las plantas responden a fluctuaciones del nivel del agua. Durante la prolongada conexión con el río el contenido de nutrientes de las hojas maduras fue alto, en tanto que durante el aislamiento prolongado las hojas tuvieron mayor contenido de lignina y alto cociente L:N. El éxito de Eichhornia crassipes en la ocupación de hábitats sujetos a amplias y erráticas fluctuaciones del nivel del agua parece estar relacionado con su capacidad para modificar sus características morfológicas en función de las fluctuaciones del nivel del agua. Abstract in english Floodplain lakes are especially dynamic due to the irregular flow regime of the Paraná River and its location along the geomorphologic gradient between the lakes and the river. The response of Eichhornia crassipes (Mart.) Solms (one of the most frequent aquatic plant) was studied in two floodplain l [...] akes with different flooding regimes. Samples were taken between March 1997 and December 2001 on 13 different hydrologic conditions during prolonged hydrologic connection and prolonged hydrologic isolation. Leaf height, leaf density, biomass and nutrient content of the mature leaves of E. crassipes were measured and related to water level fluctuation and the hydrologic connectivity. The lake more connected with the main channel had a long lasting inundation phase. In this condition the surface area covered by water increased more than three times compared to prolonged hydrologic isolation condition. As river water entered the floodplain lakes, dissolved inorganic nitrogen increased to high values, especially NO3-, whereas the isolation condition was characterised by a decrease in NO3- concentrations to undetectable levels. Compared to plants growing in the more isolated lake, those growing in the more connected lake had a significantly lower leaf density, longer leaves, less root biomass and lower ratio between below-ground and above-ground biomasses. However, total and leaf biomasses were not significantly different between sites. In each lake, differences in leaf height, leaf biomass and root biomass between prolonged hydrologic connection and isolation, as well as the insignificant relationship between leaf size and leaf density, indicate that the morphological traits of E. crassipes respond to pluri-annual water level fluctuations. The highest nutrient concentration in mature leaves was registered at the end of the prolonged hydrologic connection in the more connected lake. During the prolonged isolation, leaves had more lignin and a higher L:N ratio than at high waters, at the same sites. The success of E. crassipes in occupying habitats subjected to wide and erratic fluctuations in water level, such as the Paraná River floodplain, appears to be related to its ability to modify morphological traits according to water level. Rev. Biol. Trop. 56 (2): 613-623. Epub 2008 June 30.

  4. Impacts of Water Level Fluctuations on Kokanee Reproduction in Flathead Lake, 1984 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Decker-Hess, Janet; Clancey, Patrick (Montana Department of Fish, Wildlife and Parks, Kalispell, MT)

    1984-03-01

    This study was initiated in the fall of 1981 to delineate the extent of successful shoreline spawning of kokanee salmon in Flathead Lake and determine the impacts of the historic and present operations of Kerr and Hungry Horse dams. An investigation of the quantity and quality of groundwater and other factors affecting kokanee reproductive success in Flathead Lake began in the spring of 1982. A total of 719 redds were counted in 17 shoreline areas of Flathead Lake in1983 compared to 592 in 1981 and 1,029 in 1982. Shoreline spawning contributed three percent to the total kokanee spawning in the Flathead drainage in 1983. Fifty-nine percent of the redds were located above 2883 ft, the operational minimum pool. The majority of those redds were constructed between 2885 and 2889 ft. In areas above minimum pool, intergravel dissolved oxygen concentrations were adequate for embryo survival and exhibited a decrease with depth. Limited data indicated apparent velocity may be the key in determining redd distribution. Seventy-five percent of the redds located below minimum pool were constructed in a zone between 2869 and 2883 ft. In individual areas, apparent velocity measurements and intergravel dissolved oxygen concentrations were related to redd density. The variation in intergravel dissolved oxygen concentrations in the Yellow Bay spawning area was partially explained by lake stage fluctuation. As lake stage declined, groundwater apparent velocity increased which increased intergravel dissolved oxygen concentrations. Mean survival to the eyed stage in the three areas below minimum pool was 43 percent. Prior to exposure by lake drawdown, mean survival to the eyed stage in spawning areas above minimum pool was 87 percent. This indicated habitat most conducive to successful embryo survival was in gravels above 2883 ft. prior to significant exposure. Survival in redds exposed to either extended periods of drawdown or to temperatures less than -10% was significantly reduced to a mean of 20-30 percent. Survival in individual spawning areas exposed by lake drawdown varied from 0 to 65 percent. Groundwater reaction to lake stage explained some of the variation in individual spawning area survival. Three types of groundwater reaction to lake stage were identified. Increased survival in exposed redds resulted from two of the three types. A significant statistical relationship was determined between embryo survival and the number of days exposed by lake drawdown. The operation of Kerr Dam in 1983-84 was characterized by an early decline in lake stage, a longer period near minimum pool and a later and more rapid filling compared to the operation seen in 1981-82 and 1982-83. Based on the survival relationship observed in natural redds exposed by drawdown in 1983-84, complete mortality from exposure would have occurred to all redds constructed above 2884.7 ftor 90 percent of all redds constructed above minimum pool. Emergence traps placed over redds below minimum pool in Gravel, Blue, and Yellow bays captured fry in Gravel and Blue bays only. Duration of fry emergence in1984 was three weeks longer than in 1982 or 1983, but was not related to the date of initial redd construction. Survival to fry emergence in Gravel Bay was calculated to be 28.9 percent of egg deposition or 57,484 fry. Survival to fry emergence above and below the zone of greatest redd density was 33.6 and 245 percent, respectively, indicating a relationship between survival and spawner site selection. After analysis of the historic operation of Kerr Dam, it is believed that the dam has, and is continuing to have, a significant impact on successful shoreline spawning of kokanee salmon in Flathead Lake. Based on the evidence that prolonged exposure of salmonid embryo by dewatering causes significant mortality, the number of days the lake was held below various foot increments (2884 ft to 2888 ft) during the incubation period was investigated. The annual change in the number of days the lake was held below 2885 ft was further investigated because 80-90 percent of the redds cons

  5. Environmental assessment for the natural fluctuation of water level in Par Pond and reduced water flow in Steel Creek below L-Lake at the Savannah River Site

    International Nuclear Information System (INIS)

    The Savannah River Operations Office Strategic Plan directs Savannah River Site (SRS) to find ways to reduce operating costs, and to determine what site infrastructure must be maintained and what infrastructure is surplus. Because of the mission change, L-Lake, Par Pond, and the river water system are no longer needed to support current missions and therefore provide an opportunity for operating cost reduction. If SRS determines that L-Lake, Par Pond, and the river water system are no longer needed to support future missions and are considered surplus, appropriate NEPA documentation will be prepared. The purpose of the proposed action in this Environmental Assessment is to begin an examination of the need for the Site's river water system by (1) developing data needed to evaluate the potential environmental impacts of further reducing or eliminating the flow demands from the Site's river water system and; (2) evaluating the potential of reducing operating costs by allowing the water level in Par Pond to fluctuate naturally through reduced pumping. This action also includes reducing the current flow rates from L-Lake to Steel Creek to natural stream flows while maintaining full pool. The recently approved Par Pond CERCLA Interim Action Proposed Plan (IAPP) committed to evaluate in a NEPA document the environmental consequences of this proposed action. This document evaluated the remediation of human health and ecological risks associated with the three year drawdown of Par Pond. Should any of the parameters sampled in the reservoir and streams (e.g., water quality, biota, etc.) exceed established threshold levels during the implementation of the proposed action, water would again be pumped into the reservoir to minimize any impacts by bringing the water level back to an appropriate level about 58.2 m (195 ft)

  6. Comparison between Neural Networks and Adaptive Neuro-fuzzy Inference System in Modeling Lake Kerkini Water Level Fluctuation Lake Management using Artificial Intelligence

    Directory of Open Access Journals (Sweden)

    Christos Evangelides

    2011-01-01

    Full Text Available This study presents lake Kerkini water level simulation. Water level depends on a large number of parameters and procedures which are usually complex or non-linear. Water level was calculated, by using a model based on visual basic language. The model took account of all parameters that contribute to water level. Simulation was achieved when the model output approximated the available measured values. Afterwards, the same project was implemented by using artificial intelligence methods. These are, artificial neural networks and adaptive neuro fuzzy inference system. The basic advantage of this implementation is the fact that the output is obtained without having to use all the parameters that contribute to the final result. This means that they can be implemented for modeling systems where the procedures are not fully known or when there is a large parameter number affecting the result. Both models showed a great performance in simulating water level fluctuation and they are also suggested for prediction.

  7. Spatial patterns of zooplanktivore Chirostoma species (Atherinopsidae) during water-level fluctuation in the shallow tropical Lake Chapala, Mexico: seasonal and interannual analysis

    OpenAIRE

    Rodrigo Moncayo-Estrada; Carlos Escalera-Gallardo; Owen T. Lind

    2011-01-01

    This study addresses the influence of water-level fluctuations on fish distribution at two temporal scales: seasonal (dry and rainy) and interannual (low and high volume conditions). The analysis of abundance relationships among three zooplanktivore Chirostoma species at fifteen sites in Lake Chapala, Mexico, revealed the significant influence of contrasting conditions (P=0.0002). Seasonally, segregation was more related to species dominance in the dry season and exclusively related to enviro...

  8. Pattern and Biodiversity of Plant Community in Water-Level-Fluctuation Zone of Pengxi River After 156 m Impoundment of Three Gorges Reservoir

    Directory of Open Access Journals (Sweden)

    WANG Jian-xiu

    2009-10-01

    Full Text Available After impounding to altitude of 156 m, species, spatial pattern and biodiversity of plant community in water-level-fluctuation zone of Three Gorges Reservoir had significant changes. The plant community under altitude of 175 m beside Pengxi River and its tributary Baijia Stream in Kaixian County was studied from July to September, 2008. 108 herb sampling quadrates along five sampling transects, three beside Pengxi River and two beside Baijia Stream, were conducted. The results showed that there are 98 species of vascular plant belong to 38 families, 29 generas. 52 species of wetland plant were investigated. Therophytes(52.0% and cryptophyte (31.6% were the dominant compositions of Raunkiaer’s life. The plant community of study area belonged to 11 associations. Floodplain annual herb zone, Xanthium sibiricum zone, Paspalum paspaloides zone and Imperata cylindrica zone dispersed at the lateral side of Pengxi River and Baijia stream from riparian to altitude of 175 m. The variation and pattern of soil water content significantly influenced the distribution of plant community in water-level-fluctuation zone. There were a low herb biodiversity in water-lever fluctuation zone.

  9. [Mercury dynamics of several plants collected from the water-level fluctuation zone of the Three Gorges Reservoir area during flooding and its impact on water body].

    Science.gov (United States)

    Zhang, Xiang; Zhang, Cheng; Sun, Rong-guo; Wang, Ding-yong

    2014-12-01

    Submerged plants are a major source for the abnormal elevation of methylmercury in reservoir. Several specific plants (Echinochloa crusgalli, Cynodondactylon and Corn stover) were collected and inundated in a simulated aquatic environment in the laboratory for investigating the mercury (Hg) dynamics in plants and the release process into water, aiming to find out the properties of Hg dynamics of plants under inundation conditions and its impact on water body in the Water-Level Fluctuation Zone of the Three Gorges Reservoir Area. The results showed that the contents of total mercury in several plants were in the range of 9. 21-12.07 ng x g(-1), and the percentage content of methylmercury (MeHg) was about 1%-2%. The content of total mercury (THg) in plants gradually decreased, by 35.81%-55.96%, whereas that of the dissolved mercury (DHg) increased sharply, by 103.23% -232.15%, which indicated an emission of Hg from plants to water in the process of decomposition. Furthermore, the state of inundation provided sufficient conditions for the methylation process in plants and therefore caused an increase of the content of methylmercury in the plant residues, which was 3.04-6.63 times as much as the initial content. The concentration of dissolved methylmercury (DMeHg) in the overlying water also increased significantly by 14.84- 16.05 times compared with the initial concentration. Meanwhile, the concentration of dissolved oxygen (DO) in the overlying water was significantly and negatively correlated with DMeHg. On the other hand, the concentration of dissolved organic carbon (DOC) in the overlying water was significantly and positively correlated with DMeHg. During the whole inundation period, the increase of DHg in the overlying water accounted for 41.74% -47.01% of the total amount of THg emission, and there was a negative correlation between the content of THg in plant residues and that of DHg in the overlying water. PMID:25826925

  10. Spatial and Seasonal CH4 Flux in the Littoral Zone of Miyun Reservoir near Beijing: The Effects of Water Level and Its Fluctuation

    OpenAIRE

    YANG, MENG; Geng, Xuemeng; Grace, John; Lu, Cai; Zhu, Yi; Zhou, Yan; Lei, Guangchun

    2014-01-01

    Wetlands, and especially their littoral zones, are considered to be CH4 emissions hotspots. The recent creation of reservoirs has caused a rapid increase in the area of the world’s littoral zones. To investigate the effects of water depth and water level fluctuation on CH4 fluxes, and how these are coupled with vegetation and nutrients, we used static closed chamber and gas chromatography techniques to measure CH4 fluxes in the littoral zone of a large reservoir near Beijing, China, from Nove...

  11. Influence of water level fluctuation on the mortality and aboveground biomass of the aquatic macrophyte Eleocharis interstincta (VAHL roemer et schults

    Directory of Open Access Journals (Sweden)

    Santos Anderson Medeiros dos

    2004-01-01

    Full Text Available The goal of this study was to study the biometric alterations of Eleocharis interstincta in response to water level fluctuations in Cabiúnas Lagoon, located on the northern coast of the state of Rio de Janeiro, in the municipality of Macaé. Three quadrats of 0.0625 m² were harvested every two weeks from June/1997 to June/1998; samples were separated into stems, dead stems (detritus and rhizome; lenghted, dried and weighted. The water level fluctuated seasonally in the macrophyte stand with two periods of drawdown. The first period occurred naturally at the end of winter and beginning of spring, when rainfall in the area was normally lowest. The second period of drawdown was the result of an artificial breaching of the sandbar that isolate the lagoon from the sea. The breach was made in the summer, at the time of highest rainfall, when the water level in the lagoon reached the maximum value recorded during the study (1.35 m. There was a strongly positive correlation of the water level with stems mean height and aboveground biomass, indicating that water level played an important role in the determination of these parameters. There was a significant difference between stem height (ANOVA; p < 0.001 and biomass (ANOVA; p < 0.001 in each sampling period, ranging from 143.9 cm and 338.8 g dry wt.m-2, before the sandbar opening, to 16.3 cm and 20.2 g dry wt.m-2 respectively after the sandbar breaching. The drastic variation of the water level, leading mass mortality of the stems, together with the lowest mean biomass/stem (0.057 g dry wt.individual-1, recorded after the sandbar breaching, did not represent a strong disturbance for E. interstincta, since the resilience time estimated for this population was about 30 days.

  12. Uncertainty Analysis of the Effect of In-Stream Water Level Fluctuations on the Distributed Quantification of Stream-Aquifer Exchanges at the Regional Scale

    Science.gov (United States)

    Baratelli, F.; Flipo, N.; Lalot, E.; Beaufort, A.; Curie, F.; Moatar, F.

    2014-12-01

    The classical approach to the modeling of stream-aquifer exchanges at the regional scale (> 10 000 km2) is a conductance model in which river stages are assumed to be constant. However, time fluctuations of river stages have a significant impact. The implementation of variable river stages in hydrological models requires parameters which are difficult to estimate at regional scale. This work aims at analyzing how the quantification of stream-aquifer exchanges at the regional scale is affected by the uncertainties on the parameterization of the process. A real case study (Loire basin, 90 000 km2, France) is considered. The length of the simulated river network is 16141 km, 32% of which is in contact with an underlying aquifer. The surface and groundwater flow in the basin are simulated with EauDyssée, an integrated, distributed, physically-based hydrological model. In-stream water level fluctuations are simulated using a simplified Manning-Strickler approach. Stream-aquifer exchanges are evaluated on a 17 year period (1996-2013) at the daily time step over the river network at a resolution of 1 km. The spatial distributions and the time fluctuations of stream-aquifer exchanges obtained with different values of the quantities in Manning's equation are compared with the results of the simulation with fixed river stages. The water fluxes at the stream-aquifer interface are shown to be sensitive to the approach taken for their quantification (constant or variable river stages): in-stream water level fluctuations determine temporary reversals of the gaining or losing regime for some river reaches. Moreover, the impact of the uncertainties on the input quantities of Manning's equation is assessed. Finally, it is shown that the modeled stream-aquifer exchanges along the Loire are consistent with the longitudinal temperature profile estimated with the satellite based thermal infrared images (LANDSAT): the groundwater discharge into the Loire warms the river in winter and cools it in summer.

  13. Infiltration properties of covering soil into the void of buried concrete waste due to fluctuation of ground water level and its prevention

    International Nuclear Information System (INIS)

    Low level radioactive concrete waste will be produced in future by breaking up the nuclear facilities, and the waste will be disposed in shallow depth of ground. In order to prepare for those situation, it is needed to clarify the infiltration properties of the covering soil into the void of buried concrete waste due to the fluctuation of ground water level and to develop the prevention methods against the infiltration of the covering soil. In this study, full-scale concrete structure specimens were broken up, and were compacted in large scale testing boxes and a series tests changing water level up and down in the concrete waste and covering soil were performed. From the test results, it was found that the appropriate filter installed between the covering soil and the concrete waste, enable us to prevent the infiltration of covering soil into the void of concrete waste. (author)

  14. Spatial and seasonal CH4 flux in the littoral zone of Miyun Reservoir near Beijing: the effects of water level and its fluctuation.

    Science.gov (United States)

    Yang, Meng; Geng, Xuemeng; Grace, John; Lu, Cai; Zhu, Yi; Zhou, Yan; Lei, Guangchun

    2014-01-01

    Wetlands, and especially their littoral zones, are considered to be CH4 emissions hotspots. The recent creation of reservoirs has caused a rapid increase in the area of the world's littoral zones. To investigate the effects of water depth and water level fluctuation on CH4 fluxes, and how these are coupled with vegetation and nutrients, we used static closed chamber and gas chromatography techniques to measure CH4 fluxes in the littoral zone of a large reservoir near Beijing, China, from November 2011 to October 2012. We found that CH4 flux decreased significantly along a transect from open water to dry land, from 3.1 mg m(-2) h(-1) at the deep water site to approximately 1.3 mg m(-2) h(-1) at the shallow water site, and less than 0.01 mg m(-2) h(-1) in the non-flooded area. Water level influenced CH4 flux by affecting soil properties including soil redox potential, soil carbon and nitrogen, and bulk density. The largest emission of all was from the seasonally flooded site after a flooding event (up to 21.1 mg m(-2) h(-1)), which may have been caused by vegetation decomposition. Submerged sites had greater emissions, while the driest site had lower emissions. Immediately after the monthly measurements had been made, we removed the aboveground vegetation to enable an assessment of the gas transportation per unit of biomass. Removal of biomass decreased emissions by up to 53%. These results indicated the dominant effect of water depth on CH4 flux through effects of soil conditions, plant species composition and distribution. This study suggests that temporally flooded wetlands, including littoral zones, contribute significantly to the global CH4 burden. However, the current challenge is to capture their spatial extent and temporal variation in the fluxes. PMID:24710279

  15. Responses of N2O flux to water level fluctuation and other environmental factors at littoral zone of Miyun Reservoir: a comparison with CH4 fluxes

    Directory of Open Access Journals (Sweden)

    M. Yang

    2015-04-01

    Full Text Available There have been only a few studies that allow us to estimate the contribution of newly-created reservoirs to greenhouse gas budgets. In particular, information is limited for understanding the spatiotemporal variation of N2O flux and the underlying mechanisms in the littoral zone where complex biochemical processes are induced by water level fluctuations. A study was carried out at five different water levels (deep water area, shallow water area, seasonally flooded area, control site for seasonally flooded area and non-flooded area at the littoral zone of a temperate reservoir using the static chamber technique. Seasonal and spatial variations of N2O flux and environmental factors were monitored throughout the growing season including a flood event during summer rains. The N2O flux ranged from ?2.29 to 182.47 ?g m?2 h?1. Non-flooded dry land emitted more N2O than flooded land, no matter whether it was permanently or seasonally flooded. However, no significant difference was observed between seasonally flooded sites and their control sites. Wind speed, air temperature, soil water content, dissolved oxygen in water and soil nitrate influenced N2O flux significantly. In order to know the contrasting characteristics of N2O and CH4 fluxes in the littoral zone of the reservoir, results were compared with a previous study on CH4 emission carried out at the same sites and time with comparable methods. It showed that N2O flux and CH4 flux was influenced by distinct factors and in differing ways. This work highlights the complexity of N2O flux at the littoral zone. The different response ways of N2O and CH4 to environments implies the big challenge of greenhouse gas emission control through ecosystem management.

  16. Responses of N2O flux to water level fluctuation and other environmental factors at littoral zone of Miyun Reservoir: a comparison with CH4 fluxes

    Science.gov (United States)

    Yang, M.; Geng, X. M.; Grace, J.; Jia, Y. F.; Liu, Y. Z.; Jiao, S. W.; Shi, L. L.; Lu, C.; Zhou, Y.; Lei, G. C.

    2015-04-01

    There have been only a few studies that allow us to estimate the contribution of newly-created reservoirs to greenhouse gas budgets. In particular, information is limited for understanding the spatiotemporal variation of N2O flux and the underlying mechanisms in the littoral zone where complex biochemical processes are induced by water level fluctuations. A study was carried out at five different water levels (deep water area, shallow water area, seasonally flooded area, control site for seasonally flooded area and non-flooded area) at the littoral zone of a temperate reservoir using the static chamber technique. Seasonal and spatial variations of N2O flux and environmental factors were monitored throughout the growing season including a flood event during summer rains. The N2O flux ranged from -2.29 to 182.47 ?g m-2 h-1. Non-flooded dry land emitted more N2O than flooded land, no matter whether it was permanently or seasonally flooded. However, no significant difference was observed between seasonally flooded sites and their control sites. Wind speed, air temperature, soil water content, dissolved oxygen in water and soil nitrate influenced N2O flux significantly. In order to know the contrasting characteristics of N2O and CH4 fluxes in the littoral zone of the reservoir, results were compared with a previous study on CH4 emission carried out at the same sites and time with comparable methods. It showed that N2O flux and CH4 flux was influenced by distinct factors and in differing ways. This work highlights the complexity of N2O flux at the littoral zone. The different response ways of N2O and CH4 to environments implies the big challenge of greenhouse gas emission control through ecosystem management.

  17. Level Dynamics and Universality of Spectral Fluctuations

    OpenAIRE

    Braun, Peter; Gnutzmann, Sven; Haake, Fritz; Kus, Marek; Zyczkowski, Karol

    2000-01-01

    The spectral fluctuations of quantum (or wave) systems with a chaotic classical (or ray) limit are mostly universal and faithful to random-matrix theory. Taking up ideas of Pechukas and Yukawa we show that equilibrium statistical mechanics for the fictitious gas of particles associated with the parametric motion of levels yields spectral fluctuations of the random-matrix type. Previously known clues to that goal are an appropriate equilibrium ensemble and a certain ergodicit...

  18. Level Dynamics and Universality of Spectral Fluctuations

    CERN Document Server

    Braun, P A; Haake, F; Kus, M; Zyczkowski, K; Braun, Peter; Gnutzmann, Sven; Haake, Fritz; Kus, Marek; Zyczkowski, Karol

    2000-01-01

    The spectral fluctuations of quantum (or wave) systems with a chaotic classical (or ray) limit are mostly universal and faithful to random-matrix theory. Taking up ideas of Pechukas and Yukawa we demonstrate that equilibrium statistical mechanics for the fictitious gas of interacting particles associated with the parametric motion of levels yields spectral fluctuations of the random-matrix type. Clues are the choice of an appropriate equilibrium ensemble, a certain ergodicity of level dynamics and estimates for the frequency of avoided crossings of neighboring levels. While equilibrium statistical mechanics only predicts the average behavior of a family of dynamical systems over a certain range of a control parameter we show that the family coalesces to a single system in the classical limit. Our arguments also reveal that integrable dynamics cannot produce universal spectral fluctuations since their parametric level dynamics correspond to near ideal-gas behavior of the Pechukas-Yukawa gas.

  19. Water-Level Fluctuations of Urmia Lake: Relationship with the Long-Term Changes of Meteorological Variables (Solutions for Water-Crisis Management in Urmia Lake Basin)

    OpenAIRE

    Mojtaba Zoljoodi; Ali Didevarasl

    2014-01-01

    Urmia Lake in northwest of Iran, through the recent years has been extremely faced with the water crisis. Climate variations and anthropogenic impacts could be two main affiliated factors in this regard. We considered the long term data series of precipitation, temperature and evaporation in monthly and yearly scales in order to compare to water-level values of Urmia Lake. The statistics approaches such as: standard deviation, trend analysis, T test, Pearson and Spearma...

  20. Ecological Engineering of Drawdown Wetlands Based on Water-level Fluctuation-Baijia Stream in the Three Gorges Reservoir as a Case Study

    Directory of Open Access Journals (Sweden)

    WANG Qiang

    2012-05-01

    Full Text Available The Three Gorges Reservoir (TGR provides the benefits of flood control, electricity generation and improved transportation along the river corridor. For the purpose of flood control, the reservoir height varies between 145 m and 175 m above sea level, creating a reservoir littoral zone of about 350 km2 in total area distributed along more than 1200 km of shoreline. Most of the littoral zone is flooded during October to May and relatively dry during the remainder of the year. Water level regulation has caused marked ecological changes in the littoral zone of TGR. The littoral zone formed after impounded by TGR not only is the crucible to us, but also the ecological opportunity. The vegetation of large-scale hydro-fluctuation belt is a very valuable resource, if properly used, can turn harm into advantage. In view of the current status and existing problems of the littoral wetland in TGR, we should focus on utilizing resources of the littoral wetland eco-friendly. Based on the needs for the littoral wetland transform into the multifunctional ecological economic benefit such as increasing carbon sources, biological production, and environmental purification, we must develop the ecological engineering model of sustainable utilizing the wetland resources of the littoral zone. In view of the environment problems of TGR and its characteristics of water level fluctuation, the ecological engineering focusing on restoration of littoral wetlands have been carried out since 2008. The eco-logical engineering was mainly conducted at littoral wetlands in Baijia stream of Pengxi River of TGR, including dike-pond system, submergence tolerance wetland-woods and waterfowl habitats recreate projects. The design principle and process for the ecological engineering of littoral wetlands restoration under the condition of the periodic water level change was described in details in this paper. Effects of the ecological engineering and the benefits to the environments were assessed. In the end of the article we proposed that the ecological engineering focus on the restoration of littoral wetlands, also should consider uti.

  1. Modeling of groundwater level fluctuations using dendrochronology in alluvial aquifers

    Science.gov (United States)

    Gholami, V.; Chau, K. W.; Fadaee, F.; Torkaman, J.; Ghaffari, A.

    2015-10-01

    Groundwater is the most important water resource in semi-arid and arid regions such as Iran. It is necessary to study groundwater level fluctuations to manage disasters (such as droughts) and water resources. Dendrochronology, which uses tree-rings to reconstruct past events such as hydrologic and climatologic events, can be used to evaluate groundwater level fluctuations. In this study, groundwater level fluctuations are simulated using dendrochronology (tree-rings) and an artificial neural network (ANN) for the period from 1912 to 2013. The present study was undertaken using the Quercus Castaneifolia species, which is present in an alluvial aquifer of the Caspian southern coasts, Iran. A multilayer percepetron (MLP) network was adopted for the ANN. Tree-ring diameter and precipitation were the input parameters for the study, and groundwater levels were the outputs. After the training process, the model was validated. The validated network and tree-rings were used to simulate groundwater level fluctuations during the past century. The results showed that an integration of dendrochronology and an ANN renders a high degree of accuracy and efficiency in the simulation of groundwater levels. The simulated groundwater levels by dendrochronology can be used for drought evaluation, drought period prediction and water resources management.

  2. Global Warming and Caspian Sea Level Fluctuations

    OpenAIRE

    Ardakanian, Reza; Alemohammad, Seyed Hamed

    2013-01-01

    Coastal regions have a high social, economical and environmental importance. Due to this importance the sea level fluctuations can have many bad consequences. In this research the correlation between the increasing trend of temperature in coastal stations due to Global Warming and the Caspian Sea level has been established. The Caspian Sea level data has been received from the Jason-1 satellite. It was resulted that the monthly correlation between the temperature and sea lev...

  3. Influence of Reservoir Water Level Fluctuations on Sediment Methylmercury Concentrations Downstream of the Historical Black Butte Mercury Mine, OR

    Science.gov (United States)

    Mercury (Hg) is a pollutant of global concern due to its ability to accumulate as methylmercury (MeHg) in biota. Mercury is methylated by anaerobic microorganisms such as sulfate reducing bacteria (SRB) in water and sediment. Throughout North America, reservoirs tend to have e...

  4. Long-Term, Seasonal and Short-Term Fluctuations in the Water Level of the Southern Baltic Sea

    Directory of Open Access Journals (Sweden)

    Wolski Tomasz

    2014-09-01

    Full Text Available Aim of this work are analyses of oscillations sea levels in the Southern Baltic on a scale of short-term changes, seasonal and long-term (age. The study was based on observational data in different periods time for tide gauges station of the Polish coast. On the example of some storm situations presents the part of the baric wave and the wind in the formation of extreme sea levels. The primary cause of the annual variability of sea levels was the characteristics of the annual and semi-annual oscillations (the annual and semi-annual solar tide. In the work also determined the rate of long-term sea-level rise for the Polish coast.

  5. Global Warming and Caspian Sea Level Fluctuations

    CERN Document Server

    Ardakanian, Reza

    2013-01-01

    Coastal regions have a high social, economical and environmental importance. Due to this importance the sea level fluctuations can have many bad consequences. In this research the correlation between the increasing trend of temperature in coastal stations due to Global Warming and the Caspian Sea level has been established. The Caspian Sea level data has been received from the Jason-1 satellite. It was resulted that the monthly correlation between the temperature and sea level is high and also positive and almost the same for all the stations. But the yearly correlation was negative. It means that the sea level has decreased by the increase in temperature.

  6. The effects of land use, temperature and water level fluctuations on the emission of nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4) from organic soil cores in Iceland

    OpenAIRE

    Jansen, Elisabeth, 1968-

    2009-01-01

    Agricultural practices can affect soil microbial production and emission of the major greenhouse gases (GHG’s) nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4). The purpose of this study was to gain insight into the influence of temperature, water level and water level fluctuations on the GHG emission of soils representing the three major types of landuse in Iceland: undisturbed peatland, drained uncultivated peatland and hayfield on drained peatland. Twenty-four soi...

  7. Mesoscale wind fluctuations over Danish waters

    Energy Technology Data Exchange (ETDEWEB)

    Vincent, C.L.

    2010-12-15

    Mesoscale wind fluctuations affect the large scale integration of wind power because they undermine the day-ahead predictability of wind speed and power production, and because they can result in large fluctuations in power generation that must be balanced using reserve power. Large fluctuations in generated power are a particular problem for offshore wind farms because the typically high concentration of turbines within a limited geographical area means that fluctuations can be correlated across large numbers of turbines. Furthermore, organised mesoscale structures that often form over water, such as convective rolls and cellular convection, have length scales of tens of kilometers, and can cause large wind fluctuations on a time scale of around an hour. This thesis is an exploration of the predictability of mesoscale wind fluctuations using observations from the world's first two large offshore wind farms - Horns Rev I in the North Sea, and Nysted in the Baltic Sea. The thesis begins with a climatological analysis of wind fluctuations on time scales of 1-10 hours at the two sites. A novel method for calculating conditional climatologies of spectral information is proposed, based on binning and averaging the time axis of the Hilbert spectrum. Results reveal clear patterns between wind fluctuations and locally observed meteorological conditions. The analysis is expanded by classifying wind fluctuations on time scales of 1-3 hours according to synoptic patterns, satellite pictures and wind classes. Results indicate that cold air outbreaks and open cellular convection are a significant contributor to mesoscale wind variability at Horns Rev. The predictability of mesoscale wind fluctuations is tested by implementing standard statistical models that relate local wind variability to parameters based on a large scale weather analysis. The models show some skill, but only achieve a 15% improvement on a persistence forecast. The possibility of explicitly modelling mesoscale fluctuations in a mesoscale model is then examined using the weather research and forecasting (WRF) model. A set of case studies demonstrate that realistic hour-scale wind fluctuations and open cellular convection patterns develop in WRF simulations with 2 km horizontal grid spacing. The atmospheric conditions during one of the case studies are then used to initialise a simplified version of the model that has no large scale weather forcing, topography or surface inhomogeneties. Using the simplified model, the sensitivity of the modelled open cellular convection to choices in model setup and to aspects of the environmental forcing are tested. Finally, the cell-scale kinetic energy budget of the modelled cells is calculated, and it is shown that the buoyancy and pressure balance terms are important for cell maintenance. It is explained that the representation of mesoscale convection in a mesoscale model is not only important to end users such as wind farm operators, but to the treatment of energy transport within the boundary layer. (Author)

  8. Hydrological processes and water resources management in a dryland environment IV: Long-term groundwater level fluctuations due to variation in rainfall

    Directory of Open Access Journals (Sweden)

    J. A. Butterworth

    1999-01-01

    Full Text Available To evaluate the effects of variations in rainfall on groundwater, long-term rainfall records were used to simulate groundwater levels over the period 1953-96 at an experimental catchment in south-east Zimbabwe. Two different modelling methods were adopted. Firstly, a soil water balance model (ACRU simulated drainage from daily rainfall and evaporative demand; groundwater levels were predicted as a function of drainage, specific yield and water table height. Secondly, the cumulative rainfall departure method was used to model groundwater levels from monthly rainfall. Both methods simulated observed groundwater levels over the period 1992-96 successfully, and long-term simulated trends in historical levels were comparable. Results suggest that large perturbations in groundwater levels area a normal feature of the response of a shallow aquifer to variations in rainfall. Long-term trends in groundwater levels are apparent and reflect the effect of cycles in rainfall. Average end of dry season water levels were simulated to be almost 3 m higher in the late 1970s compared to those of the early 1990s. The simulated effect of prolonged low rainfall on groundwater levels was particularly severe during the period 1981-92 with a series of low recharge years unprecedented in the earlier record. More recently, above average rainfall has resulted in generally higher groundwater levels. The modelling methods described may be applied in the development of guidelines for groundwater schemes to help ensure safe long-term yields and to predict future stress on groundwater resources in low rainfall periods; they are being developed to evaluate the effects of land use and management change on groundwater resources.

  9. Reactor water level control device and water level control method

    International Nuclear Information System (INIS)

    The present invention provide a device of and a method for controlling fluctuation of reactor water level caused upon insertion of selected control rods performed in order to ensure reactor stability when recycling pumps of a BWR-type power plant are stopped. When it is detected that reactor operation determined by reactor power and reactor core flow rate reaches unstable region after stoppage of a portion of the recycling pumps, the speed of integral recycling pumps is lowered to a predetermined speed of revolution conducted together with the insertion of selected control rods to suppress fluctuation of the reactor water level. Namely, (1) a recycling pump state monitoring device receives recycling pump state signals as an input and outputs recycling pump stopping detection signals. (2) A selected control rod insertion operation demand judging device judges the insurance of reactor stability due to insertion of the selected control rods and outputs selected control rod insertion operation demand signals. (3) A recycling pump speed control device outputs recycling pump speed control signals to control reactor core flow rate. (4) A minimum flow rate control valve controlling device outputs minimum flow rate control valve opening operation demand signals after a predetermined period of time. (5) A feed water pump minimum flow rate control valve is disposed to a feed water pump bypass channel and operated by the output signals of the device (4). (I.S.)

  10. Spatial-temporal Dynamics of Vegetation in the Newly Created Water-level-fluctuation Zone of Three Gorges Reservoir:a Case Study in Baijia Stream, Kaixian County, China

    Directory of Open Access Journals (Sweden)

    YUAN Xing-zhong

    2012-05-01

    Full Text Available "After impoundent of the Three Gorges Reservoir, a large permanent sample plot was placed in its water-level-fluctuation zone beside Baijia Stream, Kaixian County, China. Vegetation in the plot was investigated in the summer of 2008,2009 and 2010. The result indicated that community' s component, biodiversity and aboveground biomass showed obvious spatial-temporal dynamics. Total spiecies number of vascular flora inside decreased yearly, from 52 species in 2008 to 41 species in 2009 and to 35 species in 2010. The area below 156 m in elevation was dominated by Paspalum paspaloides andXanthium sibiricum in 2008. However, Paspalum paspaloides was rapid replaced by Cynodon dactylo in 2009 and X. sibiricum expanded its distribution in upper area of the plot. In 2010, X. sibiricum depressed its population in lower areas of the plot as the Three Gorges Reservoir started to impound half month earlier in the winter of 2009 and decreased seed bank for its germination. Shannon-Wiener Index increased as elevation according to the data of 2009 and 2010, which reflected the influ-ence of submerged gradient. Aboveground biomass of vegetation in each elevation zone of the plot indicated great variation.Key words: Three Gorges Reservoir; water-level-fluctuation zone; vegetation; spatial-temporal dynamics; biodiversity"

  11. Density fluctuations level during sawtooth relaxations in tokamak plasmas

    International Nuclear Information System (INIS)

    Specific turbulence observed in TFR tokamak plasmas is discussed. The observations, performed by the analysis of density fluctuations with CO2 laser light scattering, were compared with the Andreoletti disruption model. The four phases of the specific fluctuation are presented. The specific turbulence level during the collapse, during the turbulent kink and the return phase are shown

  12. Impacts of Water Level Fluctuations on Kokanee Reproduction in Flathead Lake; Effects of Operation of Kerr and Hungry Horse Dam on Reproductive Success, 1983 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Decker-Hess, Janet; McMullin, Steve L.

    1983-11-01

    Koktneesalmon (Oncorhvnchusnerka), the land-locked form of sockeye salmon, were originally introduced to Flathead Lake in 1916. My 1933, kokanee had become established in the lake and provided a popular summer trolling fishery as well as a fall snagging fishery in shoreline areas. Presently, Flathead Lake supports the second highest fishing pressure of any lake or reservoir in Montana (Montana Department of Fish and Game 1976). During 1981-82, the lake provided 168,792 man-days of fishing pressure. Ninety-two percent of the estimated 536,870 fish caught in Flathead Lake in 1981-82 were kokanee salmon. Kokanee also provided forage for bull trout seasonally and year round for lake trout. Kokanee rear to maturity in Flathead Lake, then return to various total grounds to spawn. Spawning occurred in lake outlet streams, springs, larger rivers and lake shoreline areas in suitable but often limited habitat. Shoreline spawning in Flathead Lake was first documented in the mid-1930's. Spawning kokanee were seized from shoreline areas in 1933 and 21,000 cans were processed and packed for distribution to the needy. Stefanich (1953 and 1954) later documented extensive but an unquantified amount of spawning along the shoreline as well as runs in Whitefish River and McDonald Creek in the 1950's. A creel census conducted in 1962-63 determined 11 to 13 percent of the kokanee caught annually were taken during the spawning period (Robbins 1966). During a 1981-82 creel census, less than one percent of the fishermen on Flathead Lake were snagging kokanee (Graham and Fredenberg 1982). The operation of Kerr Dam, located below Flathead Lake on the Flathead River, has altered seasonal fluctuations of Flathead Lake. Lake levels presently remain high during kokanee spawning in November and decline during the incubation and emergence periods. Groundwater plays an important role in embryo and fry survival in redds of shoreline areas exposed by lake drawdown. Stefanich (1954) and Domrose (1968) found live eggs and fry only in shoreline spawning areas wetted by groundwater seeps. Impacts of the operation of Kerr Dam on lakeshore spawning have not been quantified. Recent studies have revealed that operation of Hungry Horse Dam severely impacted successful kokanee spawning and incubation in the Flathead River above Flathead Lake (Graham et al. 1980, McMullin and Graham 1981, Fraley and Graham 1982 and Fraley and McMullin 1983). Flows from Hungry Horse Dam to enhance kokanee reproduction in the river system have been voluntarily met by the Bureau of Reclamation since 1981. In lakeshore spawning areas in other Pacific Northwest systems, spawning habitat for kokanee and sockeye salmon was characterized by seepage or groundwater flow where suitable substrate composition existed (Foerster 1968). Spawning primarily occurred in shallower depths (<6 m) where gravels were cleaned by wave action (Hassemer and Rieman 1979 and 1980, Stober et al. 1979a). Seasonal drawdown of reservoirs can adversely affect survival of incubating kokanee eggs and fry spawned in shallow shoreline areas. Jeppon (1955 and 1960) and Whitt (1957) estimated 10-75 percent kokanee egg loss in shoreline areas of Pend Oreille Lake, Idaho after regulation of the upper three meters occurred in 1952. After 20 years of operation, Bowler (1979) found Pend Oreille shoreline spawning to occur in fewer areas with generally lower numbers of adults. In studies on Priest Lake, Idaho, Bjornn (1957) attributed frozen eggs and stranded fry to winter fluctuations of the upper three meters of the lake. Eggs and fry frozen during winter drawdown accounted for a 90 percent loss to shoreline spawning kokanee in Donner Lake, California (Kimsey 1951). Stober et al. (1979a) determined irrigation drawdown of Banks Lake, Washington reduced shoreline survival during five of the seven years the system was studied. The goal of this phase of the study was to evaluate and document effects of the operation of Kerr Dam on kokanee shoreline reproduction in Flathead Lake. Specific objectives to meet this goal ar

  13. Temporal fluctuations of formaldehyde levels inside residences

    Energy Technology Data Exchange (ETDEWEB)

    Gammage, R.B.; Hingerty, B.E.; Matthews, T.G.; Hawthorne, A.R.; Womack, D.R.; Westley, R.R.; Gupta, K.C.

    1983-01-01

    Excursions in the levels of formaldehyde were measured inside three houses. These were a 10-y-old home, a 3 y-old home prefitted with urea-formaldehyde foam insulation (UFFI), and a 2-y-old energy-efficient home. Measurements of formaldehyde were made using active and passive air-sampling devices with subsequent colorimetric analysis by the pararosaniline procedure. The variation of diurnal formaldehyde concentrations inside each house varied by up to a factor of two. Over the course of a year, the formaldehyde concentration within the 3-y-old UFFI house varied by an order of magnitude. These changes appeared to correlate with factors such as changes in the temperature, weather, and occupant activity. Inside the 2-y-old house the effects on formaldehyde levels of increased ventilation rate and the operation of a small charcoal-based air cleaner were studied. The results suggest that formaldehyde levels were not inversely proportional to the air exchange rate and that the air cleaner tested were ineffective.

  14. Sea Levels Online: Sea Level Variations of the United States Derived from National Water Level Observation Network Stations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water level records are a combination of the fluctuations of the ocean and the vertical land motion at the location of the station. Monthly mean sea level (MSL)...

  15. 40 CFR 230.24 - Normal water fluctuations.

    Science.gov (United States)

    2010-07-01

    ... OCEAN DUMPING SECTION 404(b)(1) GUIDELINES FOR SPECIFICATION OF DISPOSAL SITES FOR DREDGED OR FILL MATERIAL Potential Impacts on Physical and Chemical Characteristics of the Aquatic Ecosystem § 230.24 Normal water fluctuations....

  16. Water level control device in nuclear reactor

    International Nuclear Information System (INIS)

    Upon start-up and shutdown of a BWR type reactor, the reactor pressure often varies greatly, by which the water level in the reactor also varies greatly. In the conventional water level control method, althogh the change in the water level of the reactor is detected and calculated for the control, it can not sometime follow after the remarkable water level change due to the delay in the calculation. The present invention has been made taking notice of this. That is, an additon/subtraction calculator that conducts addition/subtraction by adding the output of a reactor pressure detector is additionally disposed to a conventional control system using a water level control device. Thus, the opening degree for the feedwater control valve or the discharge water control valve is directly changed depending on the change of the pressure in the reactor. Since the output signal of the reactor water level controller is compensated previously by the signal for the fluctuation of the reactor pressure, rapid response of the water level control can be improved to minimize the water level change. (K.M.)

  17. Effects of water vapor fluctuations on atmospheric limb radiance structure

    Science.gov (United States)

    Quang, Carine; Rialland, Valérie; Roblin, Antoine

    2010-10-01

    Airborne infrared limb-viewing sensors may be used as surveillance devices in order to detect dim military targets. These systems' performances are limited by the inhomogeneous background in the sensor field of view which impacts strongly on target detection probability. Consequently, the knowledge of the radiance small-scale angular fluctuations and their statistical properties is required to assess the sensors' detection capacity. In the stratosphere and in clear-sky conditions, the structured background is mainly due to inertia-gravity-wave and turbulence-induced temperature and density spatial fluctuations. Moreover, in the particular case of water vapor absorption bands, the mass fraction fluctuations play a non negligible role on the radiative field. Thereby, considering as a first approximation the temperature field and the water vapor field as stationary stochastic processes, the radiance autocorrelation function (ACF) can be expressed as a function of the temperature ACF and the water vapor mass fraction ACF. This paper presents the model developed to compute the two-dimensional radiance angular ACF. This model requires the absorption coefficients and their temperature derivatives, which were calculated by a line-by-line code dedicated to water vapor absorption bands. An analytical model was also developed for a simple homogeneous case, in order to validate the average values and the radiance fluctuation variance. The numerical model variance and variance distribution are also compared to SAMM2 outputs, the AFRL radiance structure computation code. The influence of water vapor fluctuations on radiance fluctuations is also discussed.

  18. How the fluctuations of water levels affect populations of invasive bivalve Corbicula fluminea (Müller, 1774) in a Neotropical reservoir? / Como a flutuação dos níveis da água afetam as populações do bivalve invasor Corbicula fluminea (Müller, 1774) em um reservatório neotropical?

    Scientific Electronic Library Online (English)

    LRP., Paschoal; DP., Andrade; G., Darrigran.

    2015-03-01

    Full Text Available Corbicula fluminea é um bivalve invasor, responsável por inúmeros problemas ambientais e econômicos ao redor do mundo. Apesar de sua capacidade de invasão, a espécie sofre certas restrições devido a fenômenos naturais em ambientes lênticos, afetando significativamente sua estrutura populacional (e.g [...] . flutuação do nível da água e a exposição à luz solar). O presente trabalho avaliou como o decréscimo temporal do nível da água de um reservatório neotropical e a exposição solar, afeta a estrutura populacional de C. fluminea. Duas amostragens foram realizadas no reservatório da Usina Hidrelétrica (UHE) de Furnas (Minas Gerais, Brasil), em 2011 e 2012. A densidade populacional, o comprimento médio e a distribuição espacial da espécie para cada ano foram estimados após amostragem em 51 quadrats (0,0625m2) dispostos em três transectos em diferentes distâncias das margens do reservatório (0, 10 e 20 m em relação a um ponto fixo). Observou-se o predomínio de C. fluminea em ambos os anos, coincidindo com o decréscimo da densidade e riqueza de espécies nativas nas áreas de amostragem. Foram registradas diferenças significativas na densidade de C. fluminea entre as distâncias da margem, sendo atribuídas principalmente à variabilidade temporal do substrato e da água desses ambientes. Registrou-se também uma tendência em aumento da densidade e agregação com o aumento da distância da margem, devido à maior estabilidade dessas áreas (>10 m). Houveram diferenças significativas no tamanho médio das conchas de C. fluminea entre às distâncias da margem e durante os anos, assim como na interação desses fatores (Distâncias vs. Anos). Tais resultados foram associados à capacidade reprodutiva e invasiva da espécie. Esse estudo revelou que eventos temporais (principalmente, a flutuação do nível da água) em ambientes lênticos neotropicais provocam alterações na densidade, tamanho médio e distribuição de C. fluminea e na composição da malacofauna nativa. Abstract in english Corbicula fluminea is an invasive bivalve responsible for several environmental and financial problems around the globe. Despite the invasive potential of this species, it suffers certain restrictions in lentic environments due to natural phenomena that significantly affect its population structure [...] (e.g. water column fluctuation and sunlight exposure). The present study addresses how temporal decline of the water level in a Neotropical reservoir and exposure to sunlight affect the population structure of C. fluminea. Samplings were carried out twice in the reservoir of Furnas Hydroelectric Power Station (HPS) (Minas Gerais, Brazil), in 2011 and 2012. Population density, spatial distribution and mean shell length of C. fluminea were estimated for each year after sampling in 51 quadrats (0.0625m2) placed on three transects at different distances along the reservoir margins (0, 10 and 20 m from a fixed-point). We observed a predominance of C. fluminea in both years, with a simultaneous gradual decrease in density and richness of native species in the sampling area. Significant differences in density of C. fluminea were registered at different distances from the margin, and are related to the temporal variability of physical conditions of the sediment and water in these environments. We also registered a trend toward an increase in the density and aggregation of C. fluminea as we moved away from the margin, due to the greater stability of these areas (>10 m). The mean shell length of C. fluminea showed significant difference between the distinct distances from the margin and during the years, as well as the interaction of these factors (Distances vs.Years). These results were associated with the reproductive and invasive capacity of this species. This study reveals that these temporal events (especially water column fluctuation) may cause alterations in density, spatial distribution and mean shell length of C. fluminea and the composition of the native malacofauna in Neotropical

  19. Dynamical Fluctuating Charge Force Fields Application to Liquid Water

    CERN Document Server

    Rick, S W; Berne, B J; Rick, Steven W.; Stuart, Steven J.

    1994-01-01

    A new molecular dynamics model in which the point charges on atomic sites are allowed to fluctuate in response to the environment is developed and applied to water. The idea for treating charges as variables is based on the concept of electronegativity equalization according to which: (a) The electronegativity of an atomic site is dependent on the atom's type and charge and is perturbed by the electrostatic potential it experiences from its neighbors and (b) Charge is transferred between atomic sites in such a way that electronegativities are equalized. The charges are treated as dynamical variables using an extended Lagrangian method in which the charges are given a fictitious mass, velocities and kinetic energy and then propagated according to Newtonian mechanics along with the atomic degrees of freedom. Models for water with fluctuating charges are developed using the geometries of two common fixed-charge water potentials: the simple point charge (SPC) and the 4-point transferable intermolecular potential ...

  20. Characterization of the level fluctuations in a physical model of the steel continuous casting mold through image processing

    Directory of Open Access Journals (Sweden)

    J.R. Miranda-Tello

    2012-01-01

    configuration resembles a perfect control of the liquid level inside the water model. A high-speed video camera was used to get several video clips of the movement of the water level profile. Several techniques were tested in order to obtain the best lighting conditions for recording the water movement. The edge-detection technique of Sobel was used to determine the profile of the liquid level in each one of the images recorded. The analysis of the dynamic behavior of the water profile showed that the fluctuations of the liquid level inside the mold have a complex structure, which is repeated over large time periods.

  1. Mesoscale wind fluctuations over Danish waters

    DEFF Research Database (Denmark)

    Vincent, Claire Louise

    2010-01-01

    Mesoscale wind uctuations aect the large scale integration of wind power because they undermine the day-ahead predictability of wind speed and power production, and because they can result in large uctuations in power generation that must be balanced using reserve power. Large uctuations in generated power are a particular problem for oshore wind farms because the typically high concentration of turbines within a limited geographical area means that uctuations can be correlated across large numbers of turbines. Furthermore, organised mesoscale structures that often form over water, such as convective rolls and cellular convection, have length scales of tens of kilometers, and can cause large wind uctuations on a time scale of around an hour. This thesis is an exploration of the predictability of mesoscale wind uctuations using observations from the world's rst two large oshore wind farms - Horns Rev I in the North Sea, and Nysted in the Baltic Sea. The thesis begins with a climatological analysis of wind uctuations on time scales of 1{10 hours at the two sites. A novel method for calculating conditional climatologies of spectral information is proposed, based on binning and averaging the time axis of the Hilbert spectrum. Results reveal clear patterns between wind uctuations and locally observed meteorological conditions. The analysis is expanded by classifying wind uctuations on time scales of 1{3 hours according to synoptic patterns, satellite pictures and wind classes. Results indicate that cold air outbreaks and open cellular convection are a signicant contributor to mesoscale wind variability at Horns Rev. The predictability of mesoscale wind uctuations is tested by implementing standard statistical models that relate local wind variability to parameters based on a large scale weather analysis. The models show some skill, but only achieve a 15% improvement on a persistence forecast. The possibility of explicitly modelling mesoscale uctuations in a mesoscale model is then examined using the weatherresearch and forecasting (WRF) model. A set of case studies demonstrate that realistic hour-scale wind uctuations and open cellular convection patterns develop in WRF simulations with 2km horizontal grid spacing. The atmospheric conditions during one of the case studies are then used to initialise a simplied version of the model that has no large scale weather forcing, topography or surface inhomogeneties. Using the simplied model, the sensitivity of the modelled open cellular convection to choices in model setup and to aspects of the environmental forcing are tested. Finally, the cell-scale kinetic energy budget of the modelled cells is calculated, and it is shown that the buoyancy and pressure balance terms are important for cell maintenance. It is explained that the representation of mesoscale convection in a mesoscale model is not only important to end users such as wind farm operators, but to the treatment of energy transport within the boundary layer.

  2. Tide-induced groundwater level fluctuation in a U-shaped coastal aquifer

    Science.gov (United States)

    Huang, Fu-Kuo; Chuang, Mo-Hsiung; Wang, Grace S.; Yeh, Hund-Der

    2015-11-01

    The prediction of groundwater level fluctuation due to tidal waves propagation in coastal aquifers is important for the planning and management of water resources in coastal areas. A two-dimensional (2-D) analytical solution is derived to describe the tidal groundwater fluctuation in an aquifer bounded by three water-land boundaries that form a U-shaped coastline. Two opposite sides represent estuary-land boundaries on which the amplitude attenuation and phase shift of the tidal movement in the estuary are considered while the third side is an ocean-land boundary. The effects of wave interaction due to the propagation of oscillating oceanic tides in the cross-shore direction inland and the transmission of the two opposite estuarine tides in the along-shore direction are investigated. Three existing head-fluctuation solutions can be considered as special cases of the present solution; one is for one-dimensional flow and the other two are for 2-D flow. A transition distance ranging from 10 to 15 times of tidal propagation length along the shoreline can be estimated based on the solution. This distance can be used to judge whether the interaction among tides is significant. The influences of hydraulic properties on the tidal fluctuations within the aquifer can therefore be assessed quantitatively. Based on sensitivity analyses, one can conclude that the tidal head is most sensitive to the transmissivity and storativity of the aquifer, and least to the damping coefficient of tidal amplitude and wave number along the estuary. The sensitivities of head fluctuation to the changes of transmissivity and storativity depend on the shoreline length and whether the interaction among waves is significant. On the other hand, the sensitivities of head fluctuation to the changes of damping coefficient and wave number increase with diagonal distance from the entry of estuary and reach the largest magnitude near the estuary far away seashore.

  3. Self-affinity and surface-area-dependent fluctuations of lake-level time series

    Science.gov (United States)

    Williams, Zachary C.; Pelletier, Jon D.

    2015-09-01

    We performed power-spectral analyses on 133 globally distributed lake-level time series after removing annual variability. Lake-level power spectra are found to be power-law functions of frequency over the range of 20 d-1 to 27 yr-1, suggesting that lake levels are globally a f-?-type noise. The spectral exponent (?), i.e., the best-fit slope of the logarithm of the power spectrum to the logarithm of frequency, is a nonlinear function of lake surface area, indicating that lake size is an important control on the magnitude of water-level variability over the range of time scales we considered. A simple cellular model for lake-level fluctuations that reproduces the observed spectral-scaling properties is presented. The model (an adaptation of a surface-growth model with random deposition and relaxation) is based on the equations governing flow in an unconfined aquifer with stochastic inputs and outputs of water (e.g., random storms). The agreement between observation and simulation suggests that lake surface area, spatiotemporal stochastic forcing, and diffusion of the groundwater table are the primary factors controlling lake water-level variability in natural (unmanaged) lakes. Water-level variability is generally considered to be a manifestation of climate trends or climate change, yet our work shows that an input with short or no memory (i.e., weather) gives rise to a long-memory nonstationary output (lake water-level). This work forms the basis for a null hypothesis of lake water-level variability that should be disproven before water-level trends are to be attributed to climate.

  4. Computer simulation study of water using a fluctuating charge model

    Indian Academy of Sciences (India)

    M Krishnan; A Verma; S Balasubramanian

    2001-10-01

    Hydrogen bonding in small water clusters is studied through computer simulation methods using a sophisticated, empirical model of interaction developed by Rick et al (S W Rick, S J Stuart and B J Berne 1994 J. Chem. Phys. 101 6141) and others. The model allows for the charges on the interacting sites to fluctuate as a function of time, depending on their local environment. The charge flow is driven by the difference in the electronegativity of the atoms within the water molecule, thus effectively mimicking the effects of polarization of the charge density. The potential model is thus transferable across all phases of water. Using this model, we have obtained the minimum energy structures of water clusters up to a size of ten. The cluster structures agree well with experimental data. In addition, we are able to distinctly identify the hydrogens that form hydrogen bonds based on their charges alone, a feature that is not possible in simulations using fixed charge models. We have also studied the structure of liquid water at ambient conditions using this fluctuating charge model.

  5. Two-Dimensional Analysis of Air-Water Interface on Superhydrophobic Grooves under Fluctuating Water Pressure.

    Science.gov (United States)

    Piao, Linfeng; Park, Hyungmin

    2015-07-28

    We theoretically investigate the collapse (i.e., wetting) transition of the air-water interface on fully submerged superhydrophobic surfaces with micro-sized grooves under the fluctuating water pressure and the diffusion of the trapped air pockets. For the analysis, a nonlinear oscillator equation to describe the dynamics of the two-dimensional air-water interface on a single groove is derived, which is solved for a range of parameters of groove geometry and harmonically fluctuating water pressure. The results show that the pressure fluctuation across the interface encourages the early collapse of a plastron before reaching the critical hydrostatic pressure (i.e., maximum immersion depth) predetermined by the geometry. The dependence of plastron longevity on the surface geometry is found such that the plastron on a narrow groove (??5 ?m) (collapses mostly due to gas diffusion) lasts days while the ones on wider grooves (>?35-45 ?m, for example), more susceptible to the oscillating pressure, last a much shorter duration. The interplay between the air compression due to water impalement and the change of the volume of impaled water due to gas diffusion determines the response of plastron to fluctuating water pressure, which is analyzed in detail through the introduction of nondimensional parameters, and the critical groove width (most vulnerable to the external perturbations) is explained further. Finally, as a countermeasure to the fluctuating water pressure, it is suggested that the enhanced advancing contact angle of the groove sidewall (e.g., hierarchical structure) mitigates the negative effects. PMID:26135133

  6. Level density and level density parameter in medium heavy nuclei including thermal and quantal fluctuation effects

    CERN Document Server

    Agrawal, B K

    1998-01-01

    In a realistic application of the SPA + RPA theory for calculation of the nuclear level densities we find that quantal fluctuation corrections (RPA) are important even up to temperature $T = 2.0$ $MeV$. This leads to a good agreement between calculated numbers and the available experimental data for $^{104}Pd$ and $^{114}Sn$, particularly the excitation energy ($E^*$) dependence. Furthermore, we also argue that $a=S^2/4E^*$ is the only correct definition of the level density parameter in the present context which is also consistent with the Bethe like level density formula.

  7. Fluctuations and local ice structure in model supercooled water

    Science.gov (United States)

    Overduin, S. D.; Patey, G. N.

    2015-09-01

    Large-scale simulations (up to 32 000 molecules) are used to analyze local structures and fluctuations for the TIP4P/2005 and TIP5P water models, under deeply supercooled conditions, near previously proposed liquid-liquid critical points. Bulk freezing does not occur in our simulations, but correlations between molecules with local ice-like structure (ice-like molecules) are strong and long ranged (˜4 nm), exceeding the shortest dimension of smaller simulation cells at the lowest temperatures considered. Correlations between ice-like molecules decay slowly at low temperature, on the order of a hundred nanoseconds. Local ice-like structure is strongly correlated with highly tetrahedral liquid structure at all times, both structures contribute to density fluctuations, and to the associated anomalous scattering. For the TIP4P/2005 and TIP5P models, we show that the apparent spontaneous liquid-liquid phase separations, recently reported [T. Yagasaki, M. Matsumoto, and H. Tanaka, Phys. Rev. E 89, 020301 (2014)] for small rectangular simulation cells below the proposed critical points, exhibit strong system size dependence and do not occur at all in the largest systems we consider. Furthermore, in the smaller rectangular systems where layers of different densities do occur, we find that the appearance of a region of low density is always accompanied simultaneously by an excess of local ice density, with no separation in time. Our results suggest that the density differences observed in direct simulations for the two models considered here are likely due to long-range correlations between ice-like molecules and do not provide strong evidence of liquid-liquid phase separation.

  8. Investigation of free level fluctuations in a simulated model of a sodium cooled Fast Breeder Reactor using pulsating conductance monitoring device

    International Nuclear Information System (INIS)

    Highlights: ? An innovative approach for measurement of water level fluctuation is presented. ? Measurement was conducted with a PC based pulsating type level sensor. ? Deployed the technique in monitoring level fluctuation in PFBR simulated facility. ? The technique helped in validation of hot pool design of PFBR, India. - Abstract: A high resolution measurement technique for rapid and accurate monitoring of water level using an in-house built pulsating conductance monitoring device is presented. The technique has the capability of online monitoring of any sudden shift in water level in a reservoir which is subjected to rapid fluctuations due to any external factor. We have deployed this novel technique for real time monitoring of water level fluctuations in a specially designed ¼ scale model of the Prototype Fast Breeder Reactor (PFBR) at Kalpakkam, India. The water level measurements in various locations of the simulated test facility were carried out in different experimental campaigns with and without inclusion of thermal baffles to it in specific operating conditions as required by the reactor designers. The amplitudes and the frequencies of fluctuations with required statistical parameters in hot water pool of the simulated model were evaluated from the online time versus water level plot in more convenient way using system software package. From experimental results it is computed that the maximum free level fluctuation in the hot pool of PFBR with baffle plates provided on the inner vessel is 30 mm which is considerably less than the value (?82 mm) obtained without having any baffle plates. The present work provided useful information for assessment of appropriate design which would be adopted in the PFBR for safe operation of the reactor.

  9. Interacting two-level defects as sources of fluctuating high-frequency noise in superconducting circuits

    Science.gov (United States)

    Müller, Clemens; Lisenfeld, Jürgen; Shnirman, Alexander; Poletto, Stefano

    2015-07-01

    Since the very first experiments, superconducting circuits have suffered from strong coupling to environmental noise, destroying quantum coherence and degrading performance. In state-of-the-art experiments, it is found that the relaxation time of superconducting qubits fluctuates as a function of time. We present measurements of such fluctuations in a 3D-transmon circuit and develop a qualitative model based on interactions within a bath of background two-level systems (TLS) which emerge from defects in the device material. In our model, the time-dependent noise density acting on the qubit emerges from its near-resonant coupling to high-frequency TLS which experience energy fluctuations due to their interaction with thermally fluctuating TLS at low frequencies. We support the model by providing experimental evidence of such energy fluctuations observed in a single TLS in a phase qubit circuit.

  10. The National Water Level Observation Network

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The fundamental observational component of the National Water Level Program (NWLP) is the National Water Level Observation Network (NWLON). The NWLON is a network...

  11. Water level monitoring device in nuclear reactor

    International Nuclear Information System (INIS)

    Purpose: To monitor the water level in a pressure vessel of BWR type nuclear reactors at high accuracy by improving the compensation functions. Constitution: In the conventional water level monitor in a nuclear reactor, if the pressure vessel is displaced by the change of the pressure in the reactor or the temperature of the reactor water, the relative level of the reference water head in a condensation vessel is changed to cause deviation between the actual water level and the indicated water level to reduce the monitoring accuracy. According to the invention, means for detecting the position of the reference water head and means for detection the position in the condensation vessel are disposed to the pressure vessel. Then, relative positional change between the condensation vessel and the reference water head is calculated based on detection sinals from both of the means. The water level is compensated and calculated by water level calculation means based on the relative positional change, water level signals from the level gage and the pressure signals from the pressure gage. As a result, if the pressure vessel is displaced due to the change of the temperature or pressure, it is possible to measure the reactor water level accurately thereby remakably improve the reliability for the water level control in the nuclear reactor. (Horiuchi, T.)

  12. A causal model for fluctuating sugar levels in diabetes patients

    OpenAIRE

    Kinzang Chhogyal; Abhaya Nayak; Rolf Schwitter; Abdul Sattar

    2012-01-01

    Background Causal models of physiological systems can be immensely useful in medicine as they may be used for both diagnostic and therapeutic reasoning. Aims In this paper we investigate how an agent may use the theory of belief change to rectify simple causal models of changing blood sugar levels in diabetes patients. Method We employ the semantic approach to belief change together with a popular measure of distance called Dalal distance between different state descriptions in order to imple...

  13. Characterization of the level fluctuations in a physical model of the steel continuous casting mold through image processing

    Scientific Electronic Library Online (English)

    J.R., Miranda-Tello; F., Sánchez-Rangel; C.A., Real-Ramírez; G., Khatchatourov; J.A., Aragón-Lezama; L.F., Hoyos-Reyes; E.A., Andrade-González; J.I., González-Trejo.

    2012-04-01

    Full Text Available In this work is characterized the periodic behavior of the liquid level inside a scaled cold-model of the mold section of a steel continuous casting machine, which uses water as working fluid. The models are designed in order to simulate the dynamic forces acting on the molten steel inside a mold of [...] continuous casting. The force magnitude can induce choppy flow, waves and vortex formation in the mold. The experimental model uses a closed-loop hydraulic configuration. In the mold, the inlet and the outlet water flow rates are the same. This configuration resembles a perfect control of the liquid level inside the water model. A high-speed video camera was used to get several video clips of the movement of the water level profile. Several techniques were tested in order to obtain the best lighting conditions for recording the water movement. The edge-detection technique of Sobel was used to determine the profile of the liquid level in each one of the images recorded. The analysis of the dynamic behavior of the water profile showed that the fluctuations of the liquid level inside the mold have a complex structure, which is repeated over large time periods.

  14. Water Density Fluctuations Relevant to Hydrophobic Hydration are Unaltered by Attractions

    CERN Document Server

    Remsing, Richard C

    2014-01-01

    An understanding of density fluctuations in bulk water has made significant contributions to our understanding of the hydration and interactions of idealized, purely repulsive hydrophobic solutes. To similarly inform the hydration of realistic hydrophobic solutes that have dispersive interactions with water, here we characterize water density fluctuations in the presence of attractive fields that correspond to solute-water attractions. We find that when the attractive field acts only in the solute hydration shell, but not in the solute core, it does not significantly alter water density fluctuations in the solute core region. We further find that for a wide range of solute sizes and attraction strengths, the free energetics of turning on the attractive fields in bulk water are accurately captured by linear response theory. Our results also suggest strategies for more efficiently estimating hydration free energies of realistic solutes in bulk water and at interfaces.

  15. THE EFFECTS OF WATER TEMPERATURE REGIME FLUCTUATIONS ON THE EMBRYONIC DEVELOPMENT OF SILVER CARP (HYPOPHTHALMICHTHYS MOLITRIX

    Directory of Open Access Journals (Sweden)

    ?. Vodyanitskyi

    2015-03-01

    Full Text Available Purpose. To determine the effect of temperature regime fluctuations on the development of silver carp embryos, as well as the activity of enzymatic reactions in fish eggs. Methodology. The studies were conducted at the experimental station of the Institute of Hydrobiology of Bila Tserkov, Ukrainian National Academy of Sciences, from June to July. The biological materials were silver carp eggs, embryos and larvae. The dissolved oxygen content was determined using the Winkler method at four o’clock in the morning. Alkalinity phosphatase and LDG activity were determined using a set of reagents «Alkalinity phosphatase» and «LDG» (Phyllis diagnosis, Ukraine. SDH activity was determined by Vexy. The activity of Na, K-Mg-dependent-activated ATPase was determined as growth of inorganic phosphorus in the incubation medium by Kindratova M.N. et al. Protease activity was determined using immune enzymatic method of Tyurina et al. The obtained results were processed statistically in Statistica 5.5, Epaprobit analysis was used for calculating LC/EC values (Version 1.5. Findings The results showed that a delay of embryonic stages of development occur, the number of abnormal embryos increases, and the reproduction efficiency of fish reduces with an increase in water temperature and decrease in the dissolved oxygen content in water. The temperature factor had a significant effect on the activity of key enzymes, in particular the energetic metabolism changed from aerobic to anaerobic. Originality. It was found a negative effect of abiotic factors of water medium and drastic fluctuations in water temperature and gas regime of water bodies on the course of embryogenesis of silver carp that is especially important in the conditions of climate change. Practical value. The obtained results showed that the level of optimum and unfavorable environmental factors during the change of embryonic stages in embryonic and larval fish can be established based on the activity of lactate dehydrogenase, succinate dehydrogenase, ATPase and protease.

  16. Does temperature affect the accuracy of vented pressure transducer in fine-scale water level measurement?

    Science.gov (United States)

    Liu, Z.; Higgins, C. W.

    2015-03-01

    Submersible pressure transducers have been utilized for collecting water level data since the early 1960s. Together with a digital data logger, it is a convenient way to record water level fluctuations for long-term monitoring. Despite the wide use of pressure transducers for water level monitoring, little has been reported regarding their accuracy and performance under field conditions. The effects of temperature fluctuations on the output of vented pressure transducers were considered in this study. The pressure transducers were tested under both laboratory and field conditions. The results of this study indicate that temperature fluctuation has a strong effect on the transducer output. Rapid changes in temperature introduce noise and fluctuations in the water level readings under a constant hydraulic head while the absolute temperature is also related to sensor errors. The former is attributed to venting and the latter is attributed to temperature compensation effects in the strain gauges. Individual pressure transducers responded differently to the thermal fluctuations in the same testing environment. In the field of surface hydrology, especially when monitoring fine-scale water level fluctuations, ignoring or failing to compensate for the temperature effect can introduce considerable error into pressure transducer readings. It is recommended that a performance test for the pressure transducer is conducted before field deployment.

  17. Development of Mechanical Water Level Controller

    OpenAIRE

    Akonyi Nasiru Sule; Chinedu Cletus Obinwa; Christian Ebele Okekeze; Eyo Ifreke

    2012-01-01

    The automatic water level controller is a device designed to regulate automatically the pumping of water to an overhead tank without allowing the water in the tank to be exhausted. The design of this mechanical device was achieved using the Archimedes principle of floatation; having a float which determines the water level in the tank depending on the choice of the minimum (lower) and maximum (upper) level inscribed in the tank. The fundamental attribute of this device is the ease in design, ...

  18. Changes in climate, catchment vegetation and hydrogeology as the causes of dramatic lake-level fluctuations in the Kurtna Lake District, NE Estonia

    OpenAIRE

    Marko Vainu; Jaanus Terasmaa

    2014-01-01

    Numerous lakes in the world serve as sensitive indicators of climate change. Water levels for lakes Ahnejärv and Martiska, two vulnerable oligotrophic closed-basin lakes on sandy plains in northeastern Estonia, fell more than 3 m in 1946–1987 and rose up to 2 m by 2009. Earlier studies indicated that changes in rates of groundwater abstraction were primarily responsible for the changes, but scientifically sound explanations for water-level fluctuations were still lacking. Despite the inconsis...

  19. A Causal Model for Fluctuating Sugar Levels in Diabetes Patients

    Directory of Open Access Journals (Sweden)

    Kinzang Chhogyal

    2012-09-01

    Full Text Available Background Causal models of physiological systems can be immensely useful in medicine as they may be used for both diagnostic and therapeutic reasoning. Aims In this paper we investigate how an agent may use the theory of belief change to rectify simple causal models of changing blood sugar levels in diabetes patients. Method We employ the semantic approach to belief change together with a popular measure of distance called Dalal distance between different state descriptions in order to implement a simple application that simulates the effectiveness of the proposed method in helping an agent rectify a simple causal model. Results Our simulation results show that distance-based belief change can help in improving the agent’s causal knowledge. However, under the current implementation there is no guarantee that the agent will learn the complete model and the agent may at times get stuck in local optima. Conclusion Distance-based belief change can help in refining simple causal models such as the example in this paper. Future work will include larger state-action spaces, better distance measures and strategies for choosing actions.

  20. Numerical simulation of the impacts of water level variation on water age in Dahuofang Reservoir

    Science.gov (United States)

    Li, Xinwen; Shen, Yongming

    2015-06-01

    The transport timescales were investigated in response to water level variation under different constant flow rates in Dahuofang Reservoir. The concept of water age was applied to quantify the transport timescales. A three-dimensional hydrodynamic model was developed based on the Environmental Fluid Dynamics Code (EFDC). The model was calibrated for water surface elevation and temperature profiles from April 1, 2008 to October 31, 2008. Comparisons of observed and modeled data showed that the model reproduced the water level fluctuation and thermal stratification during warm season and vertical mixing during cold season fairly well. The calibrated model was then applied to investigate the response of water age to water level changes in Dahuofang Reservoir. Model results showed that water age increases from confluence toward dam zone. In the vertical direction, the water age is relatively uniform at upstream and stratifies further downstream, with a larger value at bottom layer than at surface layer. Comparisons demonstrated that water level variation has a significant impact on transport timescales in the reservoir. The impact of water level drawdown on water age is stronger at bottom layer than at surface layer. Under high flow conditions, the water age decreases 0-20 days at surface layer and 15-25 days at bottom layer. Under mean flow conditions, the water age decreases 20-30 days at surface layer and 30-50 days at bottom layer. Furthermore, the impact is minor in the upstream and increases further downstream. The vertical stratification of water age weakens as the water level decreases. This study provides a numerical tool to quantify the transport timescale in Dahuofang Reservoir and supports adaptive management of regional water resources by local authorities.

  1. Changes in climate, catchment vegetation and hydrogeology as the causes of dramatic lake-level fluctuations in the Kurtna Lake District, NE Estonia

    Directory of Open Access Journals (Sweden)

    Marko Vainu

    2014-02-01

    Full Text Available Numerous lakes in the world serve as sensitive indicators of climate change. Water levels for lakes Ahnejärv and Martiska, two vulnerable oligotrophic closed-basin lakes on sandy plains in northeastern Estonia, fell more than 3 m in 1946–1987 and rose up to 2 m by 2009. Earlier studies indicated that changes in rates of groundwater abstraction were primarily responsible for the changes, but scientifically sound explanations for water-level fluctuations were still lacking. Despite the inconsistent water-level dataset, we were able to assess the importance of changing climate, catchment vegetation and hydrogeology in water-level fluctuations in these lakes. Our results from water-balance simulations indicate that before the initiation of ground­water abstraction in 1972 a change in the vegetation composition on the catchments triggered the lake-level decrease. The water-level rise in 1990–2009 was caused, in addition to the reduction of groundwater abstraction rates, by increased precipitation and decreased evaporation. The results stress that climate, catchment vegetation and hydrogeology must all be considered while evaluating the causes of modern water-level changes in lakes.

  2. Calculation and analysis of thermal–hydraulics fluctuations in pressurized water reactors

    International Nuclear Information System (INIS)

    Highlights: • Single-phase thermal–hydraulics noise equations are originally derived in the frequency domain. • The fluctuations of all the coolant parameters are calculated, without any simplifying assumptions. • The radial distribution of the temperature fluctuations in the fuel, gap and cladding are taken into account. • The closed-loop calculations are performed by means of the point kinetics noise theory. • Both the space- and frequency-dependence of the thermal–hydraulics fluctuations are analyzed. - Abstract: Analysis of thermal–hydraulics fluctuations in pressurized water reactors (e.g., local and global temperature or density fluctuations, as well as primary and charging pumps fluctuations) has various applications in calculation or measurement of the core dynamical parameters (temperature or density reactivity coefficients) in addition to thermal–hydraulics surveillance and diagnostics. In this paper, the thermal–hydraulics fluctuations in PWRs are investigated. At first, the single-phase thermal–hydraulics noise equations (in the frequency domain) are originally derived, without any simplifying assumptions. The fluctuations of all the coolant parameters, as well as the radial distribution of the temperature fluctuations in the fuel, gap and cladding are taken into account. Then, the derived governing equations are discretized using the finite volume method (FVM). Based on the discretized equations and the proposed algorithm of solving, a single heated channel noise calculation code (SHC-Noise) is developed, by which the steady-state and fluctuating parameters of PWR fuel assemblies can be calculated. The noise sources include the inlet coolant temperature and velocity fluctuations, in addition to the power density noises. The developed SHC-Noise code is benchmarked in different cases and scenarios. Furthermore, to show the effects of the power feedbacks, the closed-loop calculations are performed by means of the point kinetics noise theory. Both the space- and frequency-dependence of the temperature fluctuations are analyzed in this work

  3. Periodic fluctuations in deep water formation due to sea ice

    OpenAIRE

    Saha, Raj

    2015-01-01

    During the last ice age several quasi-periodic abrupt warming events took place. Known as Dansgaard-Oeschger (DO) events their effects were felt globally, although the North Atlantic experienced the largest temperature anomalies. Paleoclimate data shows that the fluctuations often occurred right after massive glacial meltwater releases in the North Atlantic and in bursts of three or four with progressively decreasing strengths. In this study a simple dynamical model of an ov...

  4. Model of m-level low-frequency current fluctuations in metal thermionic cathodes

    Science.gov (United States)

    Ghots, S. S.; Bakhtizin, R. Z.

    2003-06-01

    A new model of low-frequency fluctuations, based on the thermionic current model [Mathematical Handbook for Scientists and Engineers, New York, 1961; Introduction to Statistical Radio-Physic. Part 1: Random Processes, Moscow, 1976 (in Russian)], has been designed. The proposed model provides calculation of realization, auto-correlation function (ACF) and power spectral density (PSD) of an m-level quantum signal. This model has allowed to explain the reason of very small magnitude of low-frequency (LF) boundary (10 -4 to 10 -2 Hz) on experimental spectra of LF current fluctuations in a metal thermionic cathodes.

  5. Diurnal temperature fluctuations in an artificial small shallow water body

    OpenAIRE

    A. F. G. Jacobs; Heusinkveld, B.G.; Kraai, S.; Paaijmans, K.P.

    2008-01-01

    For aquatic biological processes, diurnal and annual cycles of water temperature are very important to plants as well as to animals and microbes living in the water. An existing one-dimensional model has been extended to simulate the temperature profile within a small water body. A year-round outdoor experiment has been conducted to estimate the model input parameters and to verify the model. Both model simulations and measurements show a strong temperature stratification in the water during ...

  6. Development of Mechanical Water Level Controller

    Directory of Open Access Journals (Sweden)

    Akonyi Nasiru Sule

    2012-10-01

    Full Text Available The automatic water level controller is a device designed to regulate automatically the pumping of water to an overhead tank without allowing the water in the tank to be exhausted. The design of this mechanical device was achieved using the Archimedes principle of floatation; having a float which determines the water level in the tank depending on the choice of the minimum (lower and maximum (upper level inscribed in the tank. The fundamental attribute of this device is the ease in design, fabrication and mounting at a lower cost. Its testing had shown and proved that it works efficiently with Archimedes’ principle of floatation. This eliminates the frequent human intervention/monitoring of the water level in the overhead tank to control overflow manually, thereby eliminating water and energy wastages.

  7. Periodic fluctuations in deep water formation due to sea ice

    CERN Document Server

    Saha, Raj

    2015-01-01

    During the last ice age several quasi-periodic abrupt warming events took place. Known as Dansgaard-Oeschger (DO) events their effects were felt globally, although the North Atlantic experienced the largest temperature anomalies. Paleoclimate data shows that the fluctuations often occurred right after massive glacial meltwater releases in the North Atlantic and in bursts of three or four with progressively decreasing strengths. In this study a simple dynamical model of an overturning circulation and sea ice is developed with the goal of understanding the fundamental mechanisms that could have caused the DO events. Interaction between sea ice and the overturning circulation in the model produces self-sustained oscillations. Analysis and numerical experiments reveal that the insulating effect of sea ice causes the ocean to periodically vent out accumulated heat in the deep ocean into the atmosphere. Subjecting the model to idealized freshwater forcing mimicking Heinrich events causes modulation of the natural p...

  8. Water levels in continuously monitored wells in the Yucca Mountain area, Nevada, 1985--88

    International Nuclear Information System (INIS)

    Water levels have been monitored hourly in 15 wells completed in 23 depth intervals in the Yucca Mountain area, Nevada. Water levels were monitored using pressure transducers and were recorded by data loggers. The pressure transducers were periodically calibrated by raising and lowering them in the wells. The water levels were normally measured at approximately the same time that the transducers were calibrated. Where the transducer output appeared reasonable, it was converted to water levels using the calibrations and manual water- level measurements. The amount of transducer output that was converted to water levels ranged from zero for several intervals to about 98 percent for one interval. Fourteen of the wells were completed in Tertiary volcanic rocks and one well was completed in Paleozoic carbonate rocks. Each well monitored from one to four depth intervals. Water-level fluctuation caused by barometric pressure changes and earth tides were observed

  9. The fluctuating political appeal of water engineering in Australia

    OpenAIRE

    Lin R. Crase; Suzanne M. O’Keefe; Brian E. Dollery

    2009-01-01

    Like many nations, Australia has a mixed history with water engineering. For over a century the engineer was 'king' and water was harnessed as a vehicle for settling the harsh inland, creating wealth and building prosperity. By the 1960s it was becoming increasingly clear that this approach was not without its flaws. Mounting evidence of environmental degradation emerged in the 1970s and the trend towards fiscal responsibility in the 1980s subjected the engineering approach to even greater sc...

  10. The fluctuating political appeal of water engineering in Australia

    Directory of Open Access Journals (Sweden)

    Lin R. Crase

    2009-10-01

    Full Text Available Like many nations, Australia has a mixed history with water engineering. For over a century the engineer was 'king' and water was harnessed as a vehicle for settling the harsh inland, creating wealth and building prosperity. By the 1960s it was becoming increasingly clear that this approach was not without its flaws. Mounting evidence of environmental degradation emerged in the 1970s and the trend towards fiscal responsibility in the 1980s subjected the engineering approach to even greater scrutiny. These events set the context for a series of water policy reforms that commenced in earnest in the early 1990s. Initially, the reforms favoured greater use of economic incentives and focussed attention on the ecological impacts of water management. In this environment, the status of the engineer was transformed from 'king' to 'servant'. However, the engineering profession was not to hold this status for long and the political difficulties of simultaneously dealing with the economics and ecology of water quickly became the rationale for reverting to engineering solutions. This paper traces these historical events and focusses specifically on the politically vexing issues that arise when water reallocation is attempted in a fully allocated basin.

  11. Geochemical Changes in the Caspian Salt Marshes Due to the Sea Level Fluctuations

    OpenAIRE

    Nicolay S. Kasimov; Alexandre N. Gennadiev; Maria S. Kasatenkova; Michail Y. Lychagin; Salomon B. Kroonenberg; Peter Koltermann

    2012-01-01

    The Caspian Sea is subject to alternating transgressions and regressions that exert a strong impact on the topography, sediments, vegetation, and soils in coastal zones. The last transgression of the Caspian Sea (1978-1995) caused the development of a marsh-lagoon system along the accumulative seashore of the Central Dagestan. Salt marshes are complex and dynamic systems highly vulnerable to sea level fluctuations; therefore, they may be considered as a regional model of rapid environmental c...

  12. Water-table fluctuations in the Amargosa Desert, Nye County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Paces, James B.; Whelan, Joseph

    2001-04-29

    Pleistocene ground-water discharge deposits approximately 20 km southwest of Yucca Mountain were previously thought to represent pluvial water-table rises of 80 to 120 m. Data from new boreholes at two of the three discharge sites indicate that the modern water-table is at depths of only 17 to 30 m and that this shallow water is part of the regional ground-water flow system rather than being perched. Calcite in equilibrium with this modern ground water would have isotopic compositions similar to those in Pleistocene calcite associated with the discharge deposits. Carbon and uranium isotopes in both ground water and discharge deposits imply that past discharge consisted of a mixture of both shallow and deep ground water. These data limit Pleistocene water-table fluctuations at the specified Amargosa Desert discharge sites to between 17 and 30 m and eliminate the need to invoke large water-table rises.

  13. Early Pleistocene sea level and millennial-scale climate fluctuations: a view from the tropical Pacific

    Science.gov (United States)

    Alix Jakob, Kim; Friedrich, Oliver; Pross, Jörg

    2015-04-01

    This project aims at deciphering the rate of sea level variability and its effect on millennial-scale climate fluctuations during the final phase of the intensification of northern hemisphere glaciation (NHG). Millennial-scale climate fluctuations appear to have changed significantly at glacial-interglacial time scales during the late Pliocene and Pleistocene. Thereby, millennial-scale climate fluctuations under a warmer climate during late Pliocene and early Pleistocene show markedly lower ampitudes compared to the fluctuations of the late Pleistocene. Numerous Pleistocene proxy records (e.g. McManus et al., 1999) suggest that this difference can be explained by an ice-volume/sea-level threshold that amplifies millennial-scale climate fluctuations and was not reached prior to the Mid-Pleistocene Transition (MPT). However, new records question the existence of this threshold (Bolton et al., 2010) and indicate that either the amplification of millennial-scale climate fluctuations before the MPT required a higher ice-volume threshold than in the late Pleistocene, that ice-volume had no significant effect on the amplitude of climate fluctuations, and/or the available sea level estimates for the early Pleistocene are inaccurate. For identifying the mechanisms underlying the dynamics of early Pleistocene ice sheets, material from the tropical Pacific Ocean (ODP Site 849) is studied over a time interval from 2.6 to 2.4 Ma (marine isotope stages 104 to 96). In summary, the main deliverables are (1) the establishment of a precise ?18O chemostratigraphy using the benthic foraminifera Cibicidoides wuellerstorfi by tuning the ?18O dataset to the LR04 benthic isotope stack (Lisiecki & Raymo, 2005), and (2) providing high-resolution (˜700 years) Mg/Ca and ?18O datasets using the benthic foraminifera Oridorsalis umbonatus and the planktonic foraminifera Globigerinoides ruber. This combined geochemical approach will be used to address the following research questions: (1) Quantification of sea level change from 2.6 to 2.4 Ma; (2) Critically assess the hypothesis of an ice-volume threshold for millennial-scale climate amplification during the early Pleistocene (and if it exists, what its value was); (3) Detailed comparison with late Pleistocene glacials; (4) Model-data comparison to assess the fidelity of model-based sea level estimates; and (5) reconstruction of sea surface temperature fluctuations of the tropical Pacific. References Bolton, C.T., Wilson, P.A., Bailey, I., Friedrich, O., Beer, C.J., Becker, J., Baranwal, S., Schiebel, R. (2010): Millennial-scale climate variability in the subpolar North Atlantic Ocean during the late Pliocene. Paleoceanography 25, doi:10.1029/2010PA001951. Lisiecki, L.E. & Raymo, M.E. (2005): A Pliocene-Pleistocene stack of 57 globally distributed benthic ?18O records. Paleoceanography 20, doi:10.1029/2004PA 001071. McManus, J., Oppo, D.W., Cullen, J.L. (1999): A 0.5-Million-Year Record of Millenial-Scale Climate Variability in the North Atlantic. Science 283, 971-975.

  14. Core Level Spectroscopy of Water and Ice

    OpenAIRE

    Nordlund, Dennis

    2004-01-01

    A core level spectroscopy study of ice and water is presented in this thesis. Combining a number of experiments and spectrum calculations based on density functional theory, changes in the local valence electronic structure are shown to be sensitive to the local H-bonding configurations. Exploiting this sensitivity, we are able to approach important scientific problems for a number of aggregation states; liquid water, the water-metal interface, bulk and surface of hexagonal ice. For the H-bon...

  15. Stratigraphic analysis of lake level fluctuations in Lake Ohrid: an integration of high resolution hydro-acoustic data and sediment cores

    Directory of Open Access Journals (Sweden)

    K. Lindhorst

    2010-11-01

    Full Text Available Ancient Lake Ohrid is a steep-sided, oligotrophic, karst lake that was tectonically formed most likely within the Pliocene and often referred to as a hotspot of endemic biodiversity. This study aims on tracing significant lake level fluctuations at Lake Ohrid using high-resolution acoustic data in combination with lithological, geochemical, and chronological information from two sediment cores recovered from sub-aquatic terrace levels at ca. 32 and 60 m water depth. According to our data, significant lake level fluctuations with prominent lowstands of ca. 60 and 35 m below the present water level occurred during Marine Isotope Stage (MIS 6 and MIS 5, respectively. The effect of these lowstands on biodiversity in most coastal parts of the lake is negligible, due to only small changes in lake surface area, coastline, and habitat. In contrast, biodiversity in shallower areas was more severely affected due to disconnection of today sub-lacustrine springs from the main water body. Multichannel seismic data from deeper parts of the lake clearly image several clinoform structures stacked on top of each other. These stacked clinoforms indicate significantly lower lake levels prior to MIS 6 and a stepwise rise of water level with intermittent stillstands since its existence as water-filled body, which might have caused enhanced expansion of endemic species within Lake Ohrid.

  16. Water level indicator for nuclear reactor vessel

    International Nuclear Information System (INIS)

    A water level indicator for a pressure vessel is provided which employs a plurality of vertically spaced cantilevered mounted spring members. The free end of each spring member is connected to a depending float member. The float member has sufficient mass and density to depress its spring member when the float member is in a gaseous medium. The float member has sufficient buoyancy to elevate its spring member when the float member is in a water medium. One or more strain gauges is secured to each spring member to indicate the instantaneous position of the spring member and thereby provide an indication of the instantaneous water level

  17. Water level changes along the Norwegian coast

    Science.gov (United States)

    Plag, Hans-Peter

    1984-03-01

    The water level records of 11 stations from the Norwegian coast having the recording interval 1971 1972 in common have been analysed with a least squares algorithm. The results for the harmonic constants are compared to open ocean tide models and a good agreement is found. The variation of tidal parameters and mean sea level are calculated from a 70 years water level record from Bergen. An 18.6 yearly variation in amplitude and phase of the fortnightly tide Mf could be identified. Cross correlation techniques are used to investigate the nontidal part of the water level changes. Correlating the residuals of the analyses with each other, the main nontidal water level changes are found to be moving from south to north along the Norwegian coast, taking 20 hours to reach from Stavanger to Vadsø. The effect of local air pressure on sea level is modelled using transfer functions. Mean sea level changes in Bergen are found to correlate with changes in length of day and changes in global surface temperature.

  18. Modeling Tidal Water Levels for Canadian Coastal and Offshore waters

    Science.gov (United States)

    Robin, C. M. I.; MacAulay, P.; Nudds, S.; Godin, A.; de Lange Boom, B.; Bartlett, J.; Maltais, L.; Herron, T.; Craymer, M. R.; Veronneau, M.; Fadaie, K.

    2014-12-01

    IIn 2010, the Canadian Hydrographic Service initiated the Continuous Vertical Datum for Canadian Waters (CVDCW) project, the aim of which is to connect tidal water level datums (high and low water levels, chart datum, etc.) to a national geodetic reference frame over all Canadian tidal waters. Currently, water level datums are tied to a geodetic reference frame at approximately 400 tide stations which have been surveyed with GPS, whereas water levels vary significantly in space even a short distance away from tide stations. The CVDCW captures the relevant spatial variability between stations and offshore by integrating ocean models, gauge data (water level analyses and/or GPS observations), sea level trends, satellite altimetry, and a geoid model. The CVDCW will enable the use of Global Navigation Satellite System technologies (primarily GPS) for hydrographers and navigators. It will also be important for other users including oceanographers, environmental and climate scientists, surveyors and engineers. For instance, it will allow easier integration of hydrographic and terrestrial data, provide a baseline for storm surge modeling and climate change adaptation, and aid with practical issues such as sovereignty and the definition of the coastline. Once high and low water surfaces are complete, they will define a large portion of the vertical link between land and ocean, helping to delineate flooding thresholds and inter-tidal ecosystem zones and boundaries. Here we present an overview of the methodology using a set of prototype model results, and will outline features of interest for studies in coastal stability, climate change adaptation, and sea level change.

  19. Advanced methods for modeling water-levels and estimating drawdowns with SeriesSEE, an Excel add-in

    Science.gov (United States)

    Halford, Keith; Garcia, C. Amanda; Fenelon, Joe; Mirus, Benjamin B.

    2012-01-01

    Water-level modeling is used for multiple-well aquifer tests to reliably differentiate pumping responses from natural water-level changes in wells, or “environmental fluctuations.” Synthetic water levels are created during water-level modeling and represent the summation of multiple component fluctuations, including those caused by environmental forcing and pumping. Pumping signals are modeled by transforming step-wise pumping records into water-level changes by using superimposed Theis functions. Water-levels can be modeled robustly with this Theis-transform approach because environmental fluctuations and pumping signals are simulated simultaneously. Water-level modeling with Theis transforms has been implemented in the program SeriesSEE, which is a Microsoft® Excel add-in. Moving average, Theis, pneumatic-lag, and gamma functions transform time series of measured values into water-level model components in SeriesSEE. Earth tides and step transforms are additional computed water-level model components. Water-level models are calibrated by minimizing a sum-of-squares objective function where singular value decomposition and Tikhonov regularization stabilize results. Drawdown estimates from a water-level model are the summation of all Theis transforms minus residual differences between synthetic and measured water levels. The accuracy of drawdown estimates is limited primarily by noise in the data sets, not the Theis-transform approach. Drawdowns much smaller than environmental fluctuations have been detected across major fault structures, at distances of more than 1 mile from the pumping well, and with limited pre-pumping and recovery data at sites across the United States. In addition to water-level modeling, utilities exist in SeriesSEE for viewing, cleaning, manipulating, and analyzing time-series data.

  20. Fluctuations in species-level protein expression occur during element and nutrient cycling in the subsurface.

    Science.gov (United States)

    Wilkins, Michael J; Wrighton, Kelly C; Nicora, Carrie D; Williams, Kenneth H; McCue, Lee Ann; Handley, Kim M; Miller, Chris S; Giloteaux, Ludovic; Montgomery, Alison P; Lovley, Derek R; Banfield, Jillian F; Long, Philip E; Lipton, Mary S

    2013-01-01

    While microbial activities in environmental systems play a key role in the utilization and cycling of essential elements and compounds, microbial activity and growth frequently fluctuates in response to environmental stimuli and perturbations. To investigate these fluctuations within a saturated aquifer system, we monitored a carbon-stimulated in situ Geobacter population while iron reduction was occurring, using 16S rRNA abundances and high-resolution tandem mass spectrometry proteome measurements. Following carbon amendment, 16S rRNA analysis of temporally separated samples revealed the rapid enrichment of Geobacter-like environmental strains with strong similarity to G. bemidjiensis. Tandem mass spectrometry proteomics measurements suggest high carbon flux through Geobacter respiratory pathways, and the synthesis of anapleurotic four carbon compounds from acetyl-CoA via pyruvate ferredoxin oxidoreductase activity. Across a 40-day period where Fe(III) reduction was occurring, fluctuations in protein expression reflected changes in anabolic versus catabolic reactions, with increased levels of biosynthesis occurring soon after acetate arrival in the aquifer. In addition, localized shifts in nutrient limitation were inferred based on expression of nitrogenase enzymes and phosphate uptake proteins. These temporal data offer the first example of differing microbial protein expression associated with changing geochemical conditions in a subsurface environment. PMID:23472107

  1. The effect of interaural-level-difference fluctuations on the externalization of sound

    DEFF Research Database (Denmark)

    Catic, Jasmina; Santurette, Sébastien

    2013-01-01

    Real-world sound sources are usually perceived as externalized and thus properly localized in both direction and distance. This is largely due to (1) the acoustic filtering by the head, torso, and pinna, resulting in modifications of the signal spectrum and thereby a frequency-dependent shaping of interaural cues and (2) interaural cues provided by the reverberation inside an enclosed space. This study first investigated the effect of room reverberation on the spectro-temporal behavior of interaural level differences (ILDs) by analyzing dummy-head recordings of speech played at different distances in a standard listening room. Next, the effect of ILD fluctuations on the degree of externalization was investigated in a psychoacoustic experiment performed in the same listening room. Individual binaural impulse responses were used to simulate a distant sound source delivered via headphones. The ILDs were altered using a gammatone filterbank for analysis and resynthesis, where the envelopes of the left and right-ear signals were modified such that the naturally occurring fluctuations of the ILDs were restricted. This manipulation reduced the perceived degree of externalization. This was consistent with the analysis of short-term ILDs at different distances showing that a decreased distance to the sound source also reduced the ILD fluctuations. © 2013 Acoustical Society of America.

  2. Fluctuations in Species-Level Protein Expression Occur during Element and Nutrient Cycling in the Subsurface

    Energy Technology Data Exchange (ETDEWEB)

    Wilkins, Michael J.; Wrighton, Kelly C.; Nicora, Carrie D.; Williams, Kenneth H.; McCue, Lee Ann; Handley, Kim M.; Miller, C. S.; Giloteaux, L.; Montgomery, A. P.; Lovley, Derek R.; Banfield, Jillian F.; Long, Philip E.; Lipton, Mary S.

    2013-03-05

    While microbial activities in environmental systems play a key role in the utilization and cycling of essential elements and compounds, microbial activity and growth frequently fluctuates in response to environmental stimuli and perturbations. To investigate these fluctuations within a saturated aquifer system, we monitored a carbon-stimulated in situ Geobacter population while iron reduction was occurring, using 16S rRNA abundances and high-resolution tandem mass spectrometry proteome measurements. Following carbon amendment, 16S rRNA analysis of temporally separated samples revealed the rapid enrichment of Geobacter-like environmental strains with strong similarity to G. bemidjiensis. Tandem mass spectrometry proteomics measurements suggest high carbon flux through Geobacter respiratory pathways, and the synthesis of anapleurotic four carbon compounds from acetyl-CoA via pyruvate ferredoxin oxidoreductase activity. Across a 40-day period where Fe(III) reduction was occurring, fluctuations in protein expression reflected changes in anabolic versus catabolic reactions, with increased levels of biosynthesis occurring soon after acetate arrival in the aquifer. In addition, localized shifts in nutrient limitation were inferred based on expression of nitrogenase enzymes and phosphate uptake proteins. These temporal data offer the first example of differing microbial protein expression associated with changing geochemical conditions in a subsurface environment.

  3. Analysis of Environmental Data and Landscape Characterization on Multiple WetlandTypes Using Water Level Loggers and GIS Techniques in Tampa, FL

    Science.gov (United States)

    To better characterize the relationships between both adjacent hydrology/ precipitation and nutrient processing with groundwater level fluctuations, continuous water level data are being collected across three dominant wetland types, each with varied landscape characteristics. Th...

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

    Science.gov (United States)

    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.

  5. A Convective Model Conm That Simulates Solute Redistribution Caused by Water Table Fluctuations

    OpenAIRE

    Cesáreo Landeros-Sánchez; Ma. del Refugio Castañeda-Chávez; Fabiola Lango-Reynoso; Itzel Galaviz-Villa

    2012-01-01

    A study of the solute redistribution caused by water-table fluctuations in experimental packed columns of fine sand and a sandy clay loam soil using potassium chloride as a non-reactive tracer is modelled. With the water table initially at the soil surface, the redistribution of surface applied chloride down the profile was measured after the water table was lowered, then after it was raised again to the soil surface, and then after it was again lowered. In each case, sufficient time was allo...

  6. Impact of a Fluctuating Water Table on Oxygen Transfer in the Capillary Fringe

    Science.gov (United States)

    Haberer, C. M.; Rolle, M.; Cirpka, O. A.; Grathwohl, P.

    2011-12-01

    Mass transfer processes across and within the transition region between the unsaturated and the saturated zone are important for the supply of volatile compounds from the atmosphere to groundwater. At steady state, transverse vertical dispersion is essential for mass transfer of volatile compounds across the capillary fringe. In case of rising water tables (i.e., imbibition), air becomes entrapped and volatile compounds partition between the aqueous and gaseous phases in order to reach local chemical equilibrium between the two. In particular, oxygen transfer across and within the capillary fringe is of primary relevance for many subsurface biogeochemical processes, since it largely determines the redox conditions and is used as electron acceptor in microbial respiration. Therefore, dynamic fluctuations in water table not only affect the hydraulic properties of porous media in the capillary fringe but also impact the quality of the underlying groundwater. In this study, a detailed investigation was carried out to improve understanding of oxygen transfer in a fluctuating capillary fringe. We conducted quasi two-dimensional flow-through experiments at the laboratory bench-scale to evaluate the effects of different boundary conditions on oxygen transfer. We considered single drainage and imbibition events as well as periodic fast and slow water table fluctuations. Oxygen transfer was quantified by measuring high-resolution vertical concentration profiles and effluent mass fluxes with a non-invasive optode technique. The results show that the partitioning between the aqueous and the gaseous phases plays a significant role in the supply of oxygen to groundwater at medium time scales. In case of fast water table fluctuations, the specific yield has to be considered. Moreover, a specific dynamic response of the system and, therefore, the amount of oxygen that is transferred to the oxygen-depleted groundwater are determined by the characteristics of the water table fluctuations, i.e., slow vs. fast periodic changes. In case of slow fluctuations, we observed that approximately twice as much oxygen was transferred into groundwater compared to the case of cyclic abrupt changes of the water table.

  7. Water Level Detection Using Synthetic Aperture Radar Imagery

    International Nuclear Information System (INIS)

    Reservoir water levels are of interest for international safeguards and domestic monitoring because they can be used as indicators of processing activity, uranium mine tailings protection status, or power generation for clandestine operation. Monitoring of water levels using satellite technology, especially civilian synthetic aperture radar (SAR) for remote or restricted-access sites worldwide has the potential to be a valuable tool for national/international safeguards as well as environmental monitoring applications. Unlike optical sensors, SAR is capable of reliable repeat monitoring regardless of cloud cover or solar illumination, i.e. it can image the target through clouds and darkness. Because of this ability, quick turn around for a SAR image is almost always guaranteed. SAR is very sensitive to the land/water interface and can be used to extract detailed elevation models. SAR is also sensitive to metallic structures or objects and can thus be useful in detection of heavy equipment or undeclared construction at decommissioned facilities. Although spaceborne SAR cannot match the resolution of optical satellites, future SAR satellites will offer much better resolution (e.g., approximately 3 metres for RADARSAT-2). Furthermore, future SAR satellites will offer different polarization and frequency channels to provide terrain and vegetation classification. The objective is to investigate the use of SAR for water level detection using Canada's RADARSAT-1 imagery. Three Canadian sites were chosen for our study: Niagara Area Hydro Reservoir; Quirke Lake uranium tailings management facility (TMF); and JEB Pit TMF. Initial results, using RADARSAT-1 data acquired over a three year period, show dramatic changes in both the total water surface area and markers (natural or man-made) becoming visible as the water level decreases. These very promising results indicated that SAR imagery can be used as an excellent tool for mapping remote location (which is useful for inspection planning), object detection (verification of declared activities, or detection of undeclared activities), and detection of water level fluctuation (which may be linked to a clandestine power generation during a period where optical sensors are not effective, e.g. at night or during adverse weather conditions). Additional analysis of RADARSAT-1 data, supportable by ground truth information and IKONOS imagery, is being carried out and further results are expected to be available soon. Large steep walled or terraced reservoirs, as in the case of JEB Pit TMF would require a different analysis technique. Scoping work indicated that it would be possible to deduce the water level by measuring the wall height using 'radar shadow', in a manner similar to the exploitation of shadows in optical images

  8. Attenuation of concentration fluctuations of water vapor and other trace gases in turbulent tube flow

    Directory of Open Access Journals (Sweden)

    W. J. Massman

    2008-10-01

    Full Text Available Recent studies with closed-path eddy covariance (EC systems have indicated that the attenuation of fluctuations of water vapor concentration is dependent upon ambient relative humidity, presumably due to sorption/desorption of water molecules at the interior surface of the tube. Previous studies of EC-related tube attenuation effects have either not considered this issue at all or have only examined it superficially. Nonetheless, the attenuation of water vapor fluctuations is clearly much greater than might be expected from a passive tracer in turbulent tube flow. This study reexamines the turbulent tube flow issue for both passive and sorbing tracers with the intent of developing a physically-based semi-empirical model that describes the attenuation associated with water vapor fluctuations. Toward this end, we develop a new model of tube flow dynamics (radial profiles of the turbulent diffusivity and tube airstream velocity. We compare our new passive-tracer formulation with previous formulations in a systematic and unified way in order to assess how sensitive the passive-tracer results depend on fundamental modeling assumptions. We extend the passive tracer model to the vapor sorption/desorption case by formulating the model's wall boundary condition in terms of a physically-based semi-empirical model of the sorption/desorption vapor fluxes. Finally we synthesize all modeling and observational results into a single analytical expression that captures the effects of the mean ambient humidity and tube flow (Reynolds number on tube attenuation.

  9. Forecasting monthly groundwater level fluctuations in coastal aquifers using hybrid Wavelet packet–Support vector regression

    Directory of Open Access Journals (Sweden)

    N. Sujay Raghavendra

    2015-12-01

    Full Text Available This research demonstrates the state-of-the-art capability of Wavelet packet analysis in improving the forecasting efficiency of Support vector regression (SVR through the development of a novel hybrid Wavelet packet–Support vector regression (WP–SVR model for forecasting monthly groundwater level fluctuations observed in three shallow unconfined coastal aquifers. The Sequential Minimal Optimization Algorithm-based SVR model is also employed for comparative study with WP–SVR model. The input variables used for modeling were monthly time series of total rainfall, average temperature, mean tide level, and past groundwater level observations recorded during the period 1996–2006 at three observation wells located near Mangalore, India. The Radial Basis function is employed as a kernel function during SVR modeling. Model parameters are calibrated using the first seven years of data, and the remaining three years data are used for model validation using various input combinations. The performance of both the SVR and WP–SVR models is assessed using different statistical indices. From the comparative result analysis of the developed models, it can be seen that WP–SVR model outperforms the classic SVR model in predicting groundwater levels at all the three well locations (e.g. NRMSE(WP–SVR = 7.14, NRMSE(SVR = 12.27; NSE(WP–SVR = 0.91, NSE(SVR = 0.8 during the test phase with respect to well location at Surathkal. Therefore, using the WP–SVR model is highly acceptable for modeling and forecasting of groundwater level fluctuations.

  10. Reading Ground Water Levels with a Smartphone

    Science.gov (United States)

    van Overloop, Peter-Jules

    2015-04-01

    Most ground water levels in the world are measured manually. It requires employees of water management organizations to visit sites in the field and execute a measurement procedure that requires special tools and training. Once the measurement is done, the value is jotted down in a notebook and later, at the office, entered in a computer system. This procedure is slow and prone to human errors. A new development is the introduction of modern Information and Communication Technology to support this task and make it more efficient. Two innovations are introduced to measure and immediately store ground water levels. The first method is a measuring tape that gives a sound and light when it just touches the water in combination with an app on a smartphone with which a picture needs to be taken from the measuring tape. Using dedicated pattern recognition algorithms, the depth is read on the tape and it is verified if the light is on. The second method estimates the depth using a sound from the smartphone that is sent into the borehole and records the reflecting waves in the pipe. Both methods use gps-localization of the smartphone to store the depths in the right location in the central database, making the monitoring of ground water levels a real-time process that eliminates human errors.

  11. Hydro static water level systems at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Volk, J.T.; Guerra, J.A.; Hansen, S.U.; Kiper, T.E.; Jostlein, H.; Shiltsev, V.; Chupyra, A.; Kondaurov, M.; Singatulin, S.

    2006-09-01

    Several Hydrostatic Water Leveling systems (HLS) are in use at Fermilab. Three systems are used to monitor quadrupoles in the Tevatron and two systems are used to monitor ground motion for potential sites for the International Linear Collider (ILC). All systems use capacitive sensors to determine the water level of water in a pool. These pools are connected with tubing so that relative vertical shifts between sensors can be determined. There are low beta quadrupoles at the B0 and D0 interaction regions of Tevatron accelerator. These quadrupoles use BINP designed and built sensors and have a resolution of 1 micron. All regular lattice superconducting quadrupoles (a total of 204) in the Tevatron use a Fermilab designed system and have a resolution of 6 microns. Data on quadrupole motion due to quenches, changes in temperature will be presented. In addition data for ground motion for ILC studies caused by natural and cultural factors will be presented.

  12. Characterization of the temperature fluctuations generated in a thermal mixing tee (sodium versus water behavior)

    International Nuclear Information System (INIS)

    The temperature fluctuations occurring in 1800 inlet-let angle pipe tee thermal mixers with and without inlet reducer pipes are characterized in both amplitude and frequency. Sodium and water data from different sized tees have allowed delineation of the size and fluid medium modeling laws required for the extrapolation of reduced-scale water model temperature fluctuation data to prototype LMFBR sodium mixers. The phenomena of flow corner cutoff and thermal buoyancy at a tee juncture have also been studied and their effects on mixer performance delineated. The information presented is vital both to the design of thermal-fatigue-free mixers and to the understanding of thermal mixing in complex flows; much of it has not been peviously available

  13. Cluster regression model and level fluctuation features of Van Lake, Turkey

    OpenAIRE

    Z. ?en; M. Kadio?lu; Batur, E.

    1999-01-01

    Lake water levels change under the influences of natural and/or anthropogenic environmental conditions. Among these influences are the climate change, greenhouse effects and ozone layer depletions which are reflected in the hydrological cycle features over the lake drainage basins. Lake levels are among the most significant hydrological variables that are influenced by different atmospheric and environmental conditions. Consequently, lake level time series in many parts of the world include n...

  14. The Relationship of the Processes in the Rhizosphere of Common Reed Phragmites australis, (Cav.) Trin. ex Steudel to Water Fluctuation

    Science.gov (United States)

    Urbanc-Beri, Olga; Gaberik, Alenka

    2004-11-01

    Intermittent Lake Cerknica is characterised by extreme water level fluctuations. It is neither a lake, nor a terrestrial ecosystem. The decomposition processes in the rhizosphere of extended reed stands are essential for the entire ecosystem. The influence of intermittent water regime on the microbial activity and availability of nutrients in the rhizosphere in a terrestrial reed stand was investigated. The measurements revealed a relatively high soil water content, that was not related to underground water table. Mineralization processes in a soil profile were estimated by measuring microbial activity as electron transport system (ETS) activity and by nutrients in soil water. The microbial activity was determined in the whole depth profile. The highest ETS activity of a soil was 0.23 mg O2 g DW-1 h-1, while the average value was 0.05 mg O2 g DW-1 h-1. The values were not related to underground water table. All forms of nutrients were constantly present, showing no correlation with the soil water content. ANOVA revealed significant decrease of nitrate with depth, but not for nitrite, ammonium and ortho-phosphate. (

  15. Lake level fluctuations in carbonate sequences from the Upper Freeport limestone, Appalachian Basin (Upper Allegheny group, Middle Pennsylvanian)

    Energy Technology Data Exchange (ETDEWEB)

    Valero Garces, B.L. (Univ. of Minnesota, Minneapolis, MN (United States). Limnological Research Center); Gierlowski-Kordesch, E. (Ohio Univ., Athens, OH (United States). Geological Sciences)

    1993-03-01

    Lacustrine limestone, several meters in thickness, which occur in cyclothems under coals within the upper half of the Pennsylvanian system in the Appalachian Basin, provide a remarkable case study for exploring lake dynamics within siliciclastic, deltaic-alluvial plain settings. Sedimentologic and petrologic analyses of the lacustrine Upper Freeport Limestone from core material from an area near Indiana, Pennsylvania identify carbonate sequences reflecting a complex history of water level fluctuations within a single lake during the middle Pennsylvanian. Transgression events marked by intraformational conglomerates. Shallowing-upwards sequences are composed of black shales [r arrow] wackestones/packstones [r arrow] laminated limestones [r arrow] banded limestones [r arrow] massive limestones [r arrow] nodular and brecciated limestones. Deepening sequences are composed of nodular and brecciated limestones [r arrow] black shales. Brecciated, nodular layers with pedogenetic features indicate extended periods of subaerial exposure. Using cathodoluminesce, diagenetic studies of the microfacies textures in the shallowing-upwards sequences outline the pattern of water level changes through time in the floodplain carbonate lake. These changes may be related to climatic changes and/or the dynamics of the fluvial-lacustrine system.

  16. Investment choice and perceived mating intentions regulated by external resource cues and internal fluctuation in blood glucose levels.

    Science.gov (United States)

    Rao, Li-Lin; Wang, Xiao-Tian; Li, Shu

    2014-01-01

    We examined resource allocation priorities in the framework of an updated Maslow hierarchy of fundamental human needs. In Experiment 1, the participants in the food abundance priming condition viewing photos of high-calorie food allocated more money to savings than to spending. However, the participants preferred spending to savings under the condition of mating availability priming with romantic photographs. In Experiment 2, before and after drinking either water or a sugary beverage, fasting participants rated photos of a conversation between a man and a woman. Water drinking lowered the rating scores of mating intentions as well as blood glucose (BG) levels. The sugary drink buffered this decline in sexual perceptivity. Overall, the change in BG levels was positively associated with changes in the ratings of mating intentions but was not associated with other likelihood ratings. These results suggest that both external cues of food and mating resources and internal BG fluctuation regulate the cognitive priority of physiological needs vs. mate acquisition and retention. PMID:25610412

  17. [Seasonal fluctuations in fluoride content in waters of the Warta oxbow lake in Lubo?].

    Science.gov (United States)

    Jezierska-Madziar, Maria; Pi?skwar, Piotr; Golski, Janusz

    2004-01-01

    Studies were carried out in 2002-2003 at the Department of Inland Fishing and Aquaculture, Agricultural University of Pozna?, on seasonal fluctuations in fluoride content in waters of the Warta oxbow lake in Lubo? (52 degrees 19' N, 16 degrees 53' E). This reservoir has been loaded during several decades with fluorine compounds, originating from the deposits of post-crystallization lye of aluminum fluoride and fluorosilicic acid. The greatest amounts of fluorine compounds were deposited in the bottom sediments in the deepest part of the reservoir. On the basis of these two-year observations it was concluded that the concentration of fluoride in water is subject to significant variations (between 1.0 and 6.2 mg F(-)/L). The lowest fluoride concentration in water was recorded during vernal circulation. On the other hand, the highest values were found in the bottom water layer during the summer stagnation. Seasonal fluctuations in fluoride content in waters of the Warta oxbow lake were closely connected with mineralization in the bottom sediment as revealed by oxygen deficiencies in the bottom water layer. PMID:16892585

  18. Analysis and improvements of module incidental interference faults of water level control system pressurize NPP

    International Nuclear Information System (INIS)

    In Daya Bay nuclear power plant, there have been many times that the module used to value the water level outputs a small pulse interference when the pressurizer water level control system is in operation, and the interference exists only in analog storage operation module, which can directly impact the control of the water level of the pressurizer, causing the water level fluctuations and adversely affecting the safe operation of the reactor. This paper analyzes the module incidental interference faults of the water level control system of the NPP pressurizer from the point view of the system control and design of module hardware, and finds out the reasons by the system simulation experiment and power supply circuit test. It is suggested to further improve on the design of hardware loops, add more inductance and capacity to eliminate the interference. (authors)

  19. Characteristics of fluctuations in natural water temperature in the eastern sea of Seto Inland Sea

    International Nuclear Information System (INIS)

    It is important to grasp the characteristics of fluctuation of natural water temperature when the effect of warm water discharged into sea is assessed. On the basis of the record of water temperature observed in the eastern Seto Inland Sea, the characteristics of the temperature fluctuation were studied by statistical analysis. The results obtained are as follows. The fluctuation was divided into three components, of which the period is from a day to a week, exceeding a week to a month and longer than a month. The standard deviation was 1 to 2 deg C in spring and autumn, and 0.5 to 1 deg C in summer and winter in the long period component; about 0.5 deg C in spring and autumn, and 0.3 deg C in summer and winter in the medium period component, and 0.2 to 0.4 deg C in all seasons in the short period component. The cross correlation coefficient of the long period component among three selected stations was about 1 without any time lag. That of the medium period component was 0.6 to 0.8 without time lag in temperature drop period, but 0.1 to 0.6 with 1 to 6 days delay in temperature rise period. That of the short period component showed the similar tendency to the medium period component, but the value of the coefficient was smaller. (Kako, I.)

  20. Kinetic parameters and intraindividual fluctuations of ochratoxin A plasma levels in humans

    Energy Technology Data Exchange (ETDEWEB)

    Studer-Rohr, I. [Inst. of Toxicology, Swiss Federal Inst. of Tech. and Univ. of Zurich, Schwerzenbach (Switzerland); Dept. of Food Science, Swiss Federal Inst. of Tech., Zurich (Switzerland); Schlatter, J. [Toxicology Section, Div. of Food Science, Swiss Federal Office of Public Health, Zurich (Switzerland); Dietrich, D.R. [Dept. of Environmental Toxicology, Univ. of Konstanz, Konstanz (Germany); Inst. of Toxicology, Swiss Federal Inst. of Tech. and Univ. of Zurich, Schwerzenbach (Switzerland)

    2000-11-01

    The mycotoxin ochratoxin A (OTA) is a rodent carcinogen produced by species of the ubiquitous fungal genera Aspergillus and Penicillium. OTA is found in a variety of food items and as a consequence is also found in human plasma (average concentrations found in this study: 0.1-1 ng OTA/ml plasma). To improve the scientific basis for cancer risk assessment the toxicokinetic profile of OTA was studied in one human volunteer following ingestion of 395 ng {sup 3}H-labeled OTA (3.8 {mu}Ci). A two-compartment open model consisting of a central compartment was found to best describe the in vivo data. This two-compartment model consisted of a fast elimination and distribution phase (T{sub 1/2} about 20 h) followed by a slow elimination phase (renal clearance about 0.11 ml/min.) and a calculated plasma half-life of 35.55 days. This half-life was approximately eight times longer than that determined previously in rats. In addition, the intraindividual fluctuation of OTA plasma levels was investigated in eight individuals over a period of 2 months. The concentrations determined ranged between 0.2 and 0.9 ng OTA/ml plasma. The plasma levels in some individuals remained nearly constant over time, while others varied considerably (e.g. increase of 0.4 ng/ml within 3 days, decrease of 0.3 ng/ml within 5 days) during the observation period. This intraindividual fluctuation in OTA plasma levels, which may represent differences in OTA exposure and/or metabolism, as well as the large difference in plasma half-life in humans compared to rats must be taken into consideration when the results of rat cancer study data are extrapolated to humans for risk assessment purposes. (orig.)

  1. Kinetic parameters and intraindividual fluctuations of ochratoxin A plasma levels in humans

    International Nuclear Information System (INIS)

    The mycotoxin ochratoxin A (OTA) is a rodent carcinogen produced by species of the ubiquitous fungal genera Aspergillus and Penicillium. OTA is found in a variety of food items and as a consequence is also found in human plasma (average concentrations found in this study: 0.1-1 ng OTA/ml plasma). To improve the scientific basis for cancer risk assessment the toxicokinetic profile of OTA was studied in one human volunteer following ingestion of 395 ng 3H-labeled OTA (3.8 ?Ci). A two-compartment open model consisting of a central compartment was found to best describe the in vivo data. This two-compartment model consisted of a fast elimination and distribution phase (T1/2 about 20 h) followed by a slow elimination phase (renal clearance about 0.11 ml/min.) and a calculated plasma half-life of 35.55 days. This half-life was approximately eight times longer than that determined previously in rats. In addition, the intraindividual fluctuation of OTA plasma levels was investigated in eight individuals over a period of 2 months. The concentrations determined ranged between 0.2 and 0.9 ng OTA/ml plasma. The plasma levels in some individuals remained nearly constant over time, while others varied considerably (e.g. increase of 0.4 ng/ml within 3 days, decrease of 0.3 ng/ml within 5 days) during the observation period. This intraindividual fluctuation in OTA plasma levels, which may represent differences in OTA exposure and/or metabolism, as well as the large difference in plasma half-life in humans compared to rats must be taken into consideration when the results of rat cancer study data are extrapolated to humans for risk assessment purposes. (orig.)

  2. Water table fluctuation and its effects on vegetation in a semiarid environment

    OpenAIRE

    Duan, L; liu, T; WANG X.; Luo, Y.; Wang, W; Liu, X.

    2011-01-01

    A good understanding of water table fluctuation effects on vegetation is crucial for sustaining fragile hydrology and ecology of semiarid areas such as the Horqin Sandy Land (HSL) in northern China, but such understanding is not well documented in literature. The objectives of this study were to examine spatio-temporal variations of water table and their effects on vegetation in a semiarid environment. A 9.71 km2 area within the HSL was chosen and well-instrumented to c...

  3. Investigation of temperature fluctuations caused by steam-water two-phase flow in pressurizer spray piping

    International Nuclear Information System (INIS)

    In a PWR plant, a steam-water two-phase flow may possibly exist in the pressurizer spray pipe under a normal operating condition since the flow rate of the spray water is not sufficient to fill the horizontal section of the pipe completely. Initiation of high cycle fatigue cracks is suspected to occur under such thermally stratified two phase flow conditions due to cyclic thermal stress fluctuations caused by oscillations of the water surface. Such oscillations cannot be detected by the measurement of temperature on outer surface of the pipe. In order to clarify the flow and thermal conditions in the pressurizer spray pipe and assess their impact on the pipe structure, an experiment was conducted for a steam-water flow at a low flow rate using a mock-up pressurizer spray pipe. The maximum temperature fluctuation of about 0.2 times of the steam-water temperature difference was observed at the inner wall around water surface in the test section. Visualization tests were conducted to investigate the temperature fluctuation phenomena. It was shown that the fluid temperature fluctuations were not caused by the waves on the water surface, but were caused by liquid temperature fluctuations in water layer below the interface. The influence of small amount of non-condensable gas dissolved in the reactor coolant on the liquid temperature fluctuation phenomena was investigated by injecting air into the experimental loop. The air injection attenuated the liquid temperature fluctuations in the water layer since the condensation was suppressed by the non-condensable gas. It is not expected that wall temperature fluctuation in the actual PWR plant may exceed the temperature equivalent to the fatigue limit stress amplitude when it is assumed to be proportional to the steam-water temperature difference. (author)

  4. Sound field temporal fluctuations due to mode coupling in shallow water with internal soliton

    Science.gov (United States)

    Badiey, Mohsen; Grigorev, Valery; Katsnelson, Boris; Lynch, James

    2005-09-01

    Sound field temporal fluctuations due to mode coupling, resulting from traveling internal solitons (IS) approximately along the acoustic track is addressed. The spectrum of received signal amplitude fluctuations in the range of very low frequency (~ F = 0.001-0.01 Hz) is obtained. Maximums in this spectrum, correspond to the times which IS passes the sound field ray cycles. A relationship between F-spectrum and acoustic frequency is illustrated by showing Frequency-frequency (F-f) diagram. It is shown that depending on the sound field frequency (f), different mode pairs give the most pronounced contribution to the sound intensity fluctuations. At the same time invariant frequency, F, of maximal fluctuations remains approximately the same for all sound frequency (f) bands. For example in the case of the SWARM95 experiment, F is about 0.0015 Hz for sound frequency, f in the range of 30-150 Hz. Generally, F depends on waveguide parameters and velocity of IS. In this paper, the physical meaning of the invariant frequency and its relationship to the sound frequency is discussed. In addition, the experimental setup for observation of F in future shallow-water acoustic experiments is proposed. [Work supported by CRDF, PFBR and ONR-321OA.

  5. Optimal control of a qubit coupled to a two-level fluctuator

    CERN Document Server

    Rebentrost, P; Serban, I; Wilhelm, F K

    2006-01-01

    A central challenge for implementing quantum computing in the solid state is decoupling the qubits from the intrinsic noise of the material. We investigate limits of controllability for a paradigmatic model: A single qubit coupled to a two-level fluctuator exposed to a heat bath. We systematically search for optimal pulses using a generalization of the novel open system Gradient Ascent Pulse Engineering (GRAPE) algorithm. We show and explain that next to the known optimal bias point of this model, there are optimal shapes which refocus unwanted terms in the Hamiltonian. We study the limitations of control set by the decoherence properties in the fast flipping regime, which go beyond a simple random telegraph noise model. This can lead to a significant improvement of quantum operations in hostile environments.

  6. Magnitude and sign correlations in conductance fluctuations of horizontal oil water two-phase flow

    Science.gov (United States)

    Zhu, L.; Jin, N. D.; Gao, Z. K.; Zong, Y. B.; Zhai, L. S.; Wang, Z. Y.

    2012-05-01

    In experiment we firstly define five typical horizontal oil-water flow patterns. Then we introduce an approach for analyzing signals by decomposing the original signals increment into magnitude and sign series and exploring their scaling properties. We characterize the nonlinear and linear properties of horizontal oil-water two-phase flow, which relate to magnitude and sign series respectively. We find that the joint distribution of different scaling exponents can effectively identify flow patterns, and the detrended fluctuation analysis (DFA) on magnitude and sign series can represent typical horizontal oil-water two-phase flow dynamics characteristics. The results indicate that the magnitude and sign decomposition method can be a helpful tool for characterizing complex dynamics of horizontal oil-water two-phase flow.

  7. Magnitude and sign correlations in conductance fluctuations of horizontal oil water two-phase flow

    International Nuclear Information System (INIS)

    In experiment we firstly define five typical horizontal oil-water flow patterns. Then we introduce an approach for analyzing signals by decomposing the original signals increment into magnitude and sign series and exploring their scaling properties. We characterize the nonlinear and linear properties of horizontal oil-water two-phase flow, which relate to magnitude and sign series respectively. We find that the joint distribution of different scaling exponents can effectively identify flow patterns, and the detrended fluctuation analysis (DFA) on magnitude and sign series can represent typical horizontal oil-water two-phase flow dynamics characteristics. The results indicate that the magnitude and sign decomposition method can be a helpful tool for characterizing complex dynamics of horizontal oil-water two-phase flow.

  8. Quantum fluctuations and isotope effects in ab initio descriptions of water

    CERN Document Server

    Wang, Lu; Markland, Thomas E

    2014-01-01

    Nuclear quantum effects, such as zero-point energy and tunneling, cause significant changes to the structure and dynamics of hydrogen bonded systems such as liquid water. However, due to the current inability to simulate liquid water using an exact description of its electronic structure, the interplay between nuclear and electronic quantum effects remains unclear. Here we use simulations that incorporate the quantum mechanical nature of both the nuclei and electrons to provide a fully ab initio determination of the particle quantum kinetic energies, free energy change upon exchanging hydrogen for deuterium and the isotope fractionation ratio in water. These properties, which selectively probe the quantum nature of the nuclear degrees of freedom, allow us to make direct comparison to recent experiments and elucidate how electronic exchange and correlation and nuclear quantum fluctuations determine the structure of the hydrogen bond in water.

  9. Quantum fluctuations and isotope effects in ab initio descriptions of water

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lu; Markland, Thomas E., E-mail: tmarkland@stanford.edu [Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, California 94305 (United States); Ceriotti, Michele, E-mail: michele.ceriotti@epfl.ch [Laboratory of Computational Science and Modeling, École Polytechnique Fédérale de Lausanne, 1015 Lausanne (Switzerland)

    2014-09-14

    Isotope substitution is extensively used to investigate the microscopic behavior of hydrogen bonded systems such as liquid water. The changes in structure and stability of these systems upon isotope substitution arise entirely from the quantum mechanical nature of the nuclei. Here, we provide a fully ab initio determination of the isotope exchange free energy and fractionation ratio of hydrogen and deuterium in water treating exactly nuclear quantum effects and explicitly modeling the quantum nature of the electrons. This allows us to assess how quantum effects in water manifest as isotope effects, and unravel how the interplay between electronic exchange and correlation and nuclear quantum fluctuations determine the structure of the hydrogen bond in water.

  10. Numerical analysis of a three-phase system with a fluctuating water table

    International Nuclear Information System (INIS)

    Numerical simulations are presented of a one-dimensional, multiphase flow system that involves the redistribution of aqueous-phase liquids and nonaqueous-phase liquids (NAPLs) by a fluctuating water table. The numerical analyses were completed using an integrated-volume, finite-difference-based solution scheme of the governing multiphase conservation equations and constitutive theory. Conservation equations were solved for two components water and oil, with the assumption of a passive gas-phase. Nonlinearities introduced into the governing conservation equations through the constitutive theory were handled with a multivariable Newton-Raphson iterative scheme. The functional relationships between the phase relative permeability, the phase saturation, and phase pressures in porous media were described with a general theoretical model that includes the effects of air and oil occlusion during imbibition. Parameters required for the theoretical model were defined for two-phase systems (e.g., air- water, air-oil, and oil-water). The theoretical model assumes that wettability decreases in the following order: water, oil, air. Results from the numerical simulations are compared against measurements taken from a previous multiphase flow experiment. The experiment involved subjecting an initially water-drained, three-phase system (i.e., air-oil-water), to a fluctuating water table. The experimental objective was to quantify the entrapment of air and NAPL by phases of greater wettability under dynamic conditions. Comparison of numerical and experimental results were made for two ratios of imbibition to drainage characteristic, curve-shape parameters and two models for relative permeability in two-phase systems. A description of the numerical methods used to solve the governing conservation and constitutive equations for multiphase hysteretic conditions is given

  11. Water table fluctuation and its effects on vegetation in a semiarid environment

    Directory of Open Access Journals (Sweden)

    L. Duan

    2011-04-01

    Full Text Available A good understanding of water table fluctuation effects on vegetation is crucial for sustaining fragile hydrology and ecology of semiarid areas such as the Horqin Sandy Land (HSL in northern China, but such understanding is not well documented in literature. The objectives of this study were to examine spatio-temporal variations of water table and their effects on vegetation in a semiarid environment. A 9.71 km2 area within the HSL was chosen and well-instrumented to continuously measure hydrometeorologic parameters (e.g., water table. The area comprises of meadow lands and sandy dunes as well as transitional zones in between. In addition to those measured data, this study also used Landsat TM and MODIS imageries and meteorological data at a station near the study area. The spatio-temporal variations were examined using visual plots and contour maps, while the effects on vegetation were determined by overlaying a water table depth map with a vegetation index map derived from the MODIS imageries. The results indicated that water table was mainly dependent on local topography, localized geological settings, and human activities (e.g., reclamation. At annual and monthly scales, water table was mainly a function of precipitation and potential evapotranspiration. A region within the study area where depth to water table was smaller tended to have better (i.e., more dense and productive vegetation cover. Further, the results revealed that water table fluctuation was more sensitive for vegetations in the meadow lands than in the transitional zones, but it was least sensitive for vegetations in the sandy dunes.

  12. Contribution of climate-driven change in continental water storage to recent sea-level rise

    OpenAIRE

    P. C. D. Milly; Cazenave, A.; Gennero, C.

    2003-01-01

    Using a global model of continental water balance, forced by interannual variations in precipitation and near-surface atmospheric temperature for the period 1981–1998, we estimate the sea-level changes associated with climate-driven changes in storage of water as snowpack, soil water, and ground water; storage in ice sheets and large lakes is not considered. The 1981–1998 trend is estimated to be 0.12 mm/yr, and substantial interannual fluctuations are inferred; for 1993–1998, the trend is 0....

  13. Trend Estimation of Blood Glucose Level Fluctuations Based on Data Mining

    Directory of Open Access Journals (Sweden)

    Masaki Yamaguchi

    2003-06-01

    Full Text Available We have fabricated calorie-calculating software that calculates and records the total calorific food intake by choosing a meal menu selected using a computer mouse. The purpose of this software was to simplify data collection throughout a person's normal life, even if they were inexperienced computer operators. Three portable commercial devices have also been prepared a blood glucose monitor, a metabolic rate monitor and a mobile-computer, and linked into the calorie-calculating software. Time-course changes of the blood glucose level, metabolic rate and food intake were measured using these devices during a 3 month period. Based on the data collected in this study we could predict blood glucose levels of the next morning (FBG by modeling using data mining. Although a large error rate was found for predicting the absolute value, conditions could be found that improved the accuracy of the predicting trends in blood glucose level fluctuations by up to 90 %. However, in order to further improve the accuracy of estimation it was necessary to obtain further details about the patients' life style or to optimise the input variables that were dependent on each patient rather than collecting data over longer periods.

  14. Detecting drawdowns masked by environmental stresses with water-level models

    Science.gov (United States)

    Garcia, C.A.; Halford, K.J.; Fenelon, J.M.

    2013-01-01

    Detecting and quantifying small drawdown at observation wells distant from the pumping well greatly expands the characterized aquifer volume. However, this detection is often obscured by water level fluctuations such as barometric and tidal effects. A reliable analytical approach for distinguishing drawdown from nonpumping water-level fluctuations is presented and tested here. Drawdown is distinguished by analytically simulating all pumping and nonpumping water-level stresses simultaneously during the period of record. Pumping signals are generated with Theis models, where the pumping schedule is translated into water-level change with the Theis solution. This approach closely matched drawdowns simulated with a complex three-dimensional, hypothetical model and reasonably estimated drawdowns from an aquifer test conducted in a complex hydrogeologic system. Pumping-induced changes generated with a numerical model and analytical Theis model agreed (RMS as low as 0.007 m) in cases where pumping signals traveled more than 1 km across confining units and fault structures. Maximum drawdowns of about 0.05 m were analytically estimated from field investigations where environmental fluctuations approached 0.2?m during the analysis period.

  15. Hydrostatic Water Level Systems At Homestake DUSEL

    Science.gov (United States)

    Stetler, L. D.; Volk, J. T.

    2009-12-01

    Two arrays of Fermilab-style hydrostatic water level sensors have been installed in the former Homestake gold mine in Lead, SD, the site of the new Deep Underground Science and Engineering Laboratory (DUSEL). Sensors were constructed at Fermilab from 8.5 cm diameter PVC pipe (housing) that was sealed on the ends and fit with a proximity sensor. The instrument have a height of 10 cm. Two ports in each sensor housing provide for connectivity, the upper port for air and the bottom port for water. Multiple instruments connected in series provide a precise water level and differences in readings between successive sensors provide for ground tilt to be resolved. Sensor resolution is 5 ?m per count and has a range of approximately 1.25 cm. Data output from each sensor is relayed to a Fermilab-constructed readout card that also has temperature/relative humidity and barometric pressure sensors connected. All data are relayed out of the mine by fiber optic cable and can be recorded by Ethernet at remote locations. The current arrays have been installed on the 2000-ft level (610 m) and consist of six instruments in each array. Three sensors were placed in a N-S oriented drift and three in an E-W oriented drift. Using this orientation, it is anticipated that tilt direction may be resolved in addition to overall tilt magnitude. To date the data show passage of earth tides and frequency analysis has revealed five components to this signal, three associated with the semi-diurnal (~12.4 hr) and two with the diurnal (~24.9 hr) tides. Currently, installation methods are being analyzed between concrete pillar and rib-mounting using the existing setup on the 2000-ft level. Using these results, two additional arrays of Fermilab instruments will be installed on the 4550-ft and 4850-ft levels (1387 and 1478 m, respectively). In addition to Fermilab instruments, several high resolution Budker tiltmeters (1 ?m resolution) will be installed in the mine workings in the near future, some correlated to Fermilab instruments (for comparative analysis) and others in independent arrays. All tiltmeter data will be analyzed with water reduction data (currently being collected from the #6 winze as the mine is dewatered) and data from rock stress/fracture experiments to document net ground settling due to dewatering, potential collapse of stope areas and renewed excavation activities.

  16. Relationship between fluctuations in glucose levels measured by continuous glucose monitoring and vascular endothelial dysfunction in type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Torimoto Keiichi

    2013-01-01

    Full Text Available Abstract Background Fluctuations in blood glucose level cause endothelial dysfunction and play a critical role in onset and/or progression of atherosclerosis. We hypothesized that fluctuation in blood glucose levels correlate with vascular endothelial dysfunction and that this relationship can be assessed using common bedside medical devices. Methods Fluctuations in blood glucose levels were measured over 24?hours by continuous glucose monitoring (CGM on admission day 2 in 57 patients with type 2 diabetes mellitus. The reactive hyperemia index (RHI, an index of vascular endothelial function, was measured using peripheral arterial tonometry (EndoPAT on admission day 3. Results The natural logarithmic-scaled RHI (L_RHI correlated with SD (r=?0.504; PPP=0.001 and percentage of time ?200?mg/dl (r=?0.292; P=0.028. In 12 patients with hypoglycemia, L_RHI also correlated with the percentage of time at hypoglycemia (r=?0.589; P=0.044. L_RHI did not correlate with HbA1c or fasting plasma glucose levels. Furthermore, L_RHI did not correlate with LDL cholesterol, HDL cholesterol, and triglyceride levels or with systolic and diastolic blood pressures. Finally, multivariate analysis identified MAGE as the only significant determinant of L_RHI. Conclusions Fluctuations in blood glucose levels play a significant role in vascular endothelial dysfunction in type 2 diabetes. Trial registration UMIN000007581

  17. On the microscopic fluctuations driving the NMR relaxation of quadrupolar ions in water

    Science.gov (United States)

    Carof, Antoine; Salanne, Mathieu; Charpentier, Thibault; Rotenberg, Benjamin

    2015-11-01

    Nuclear Magnetic Resonance (NMR) relaxation is sensitive to the local structure and dynamics around the probed nuclei. The Electric Field Gradient (EFG) is the key microscopic quantity to understand the NMR relaxation of quadrupolar ions, such as 7Li+, 23Na+, 25Mg2+, 35Cl-, 39K+, or 133Cs+. Using molecular dynamics simulations, we investigate the statistical and dynamical properties of the EFG experienced by alkaline, alkaline Earth, and chloride ions at infinite dilution in water. Specifically, we analyze the effect of the ionic charge and size on the distribution of the EFG tensor and on the multi-step decay of its auto-correlation function. The main contribution to the NMR relaxation time arises from the slowest mode, with a characteristic time on the picosecond time scale. The first solvation shell of the ion plays a dominant role in the fluctuations of the EFG, all the more that the ion radius is small and its charge is large. We propose an analysis based on a simplified charge distribution around the ion, which demonstrates that the auto-correlation of the EFG, hence the NMR relaxation time, reflects primarily the collective translational motion of water molecules in the first solvation shell of the cations. Our findings provide a microscopic route to the quantitative interpretation of NMR relaxation measurements and open the way to the design of improved analytical theories for NMR relaxation for small ionic solutes, which should focus on water density fluctuations around the ion.

  18. Response of New zealand mudsnails Potamopyrgus antipodarum to freezing and near freezing fluctuating water temperatures

    Science.gov (United States)

    Moffitt, Christine M.; James, Christopher A.

    2012-01-01

    We explored the resilience of the invasive New Zealand mudsnail Potamopyrgus antipodarum to fluctuating winter freezing and near-freezing temperature cycles in laboratory tests. Our goal was to provide data to confirm field observations of mortality and presumed mortality in stream habitats with fluctuating freezing to near-freezing temperatures. We tested individuals from 2 locations with distinctly different thermal regimes and population densities. One location had low snail densities and water temperatures with strong diel and seasonal water variation. The other location had high snail densities and nearly constant water temperatures. Groups of individuals from both locations were tested in each of 3 laboratory-created diel thermal cycles around nominal temperatures of 0, 2, or 4°C. Mortality occurred in cycles around 0°C in both populations, and little to no mortality occurred at temperatures >0°C. Individuals from both sources held in diel 0°C cycles for 72 h showed 100% mortality. Our findings support observations from published field studies that survival was limited in infested habitats subject to freezing temperatures.

  19. Hunger games: fluctuations in blood glucose levels influence support for social welfare.

    Science.gov (United States)

    Aarøe, Lene; Petersen, Michael Bang

    2013-12-01

    Social-welfare policies are a modern instantiation of a phenomenon that has pervaded human evolutionary history: resource sharing. Ancestrally, food was a key shared resource in situations of temporary hunger. If evolved human psychology continues to shape how individuals think about current, evolutionarily novel conditions, this invites the prediction that attitudes regarding welfare politics are influenced by short-term fluctuations in hunger. Using blood glucose levels as a physiological indicator of hunger, we tested this prediction in a study in which participants were randomly assigned to conditions in which they consumed soft drinks containing either carbohydrates or an artificial sweetener. Analyses showed that participants with experimentally induced low blood glucose levels expressed stronger support for social welfare. Using an incentivized measure of actual sharing behavior (the dictator game), we further demonstrated that this increased support for social welfare does not translate into genuinely increased sharing motivations. Rather, we suggest that it is "cheap talk" aimed at increasing the sharing efforts of other individuals. PMID:24171932

  20. Water levels in continuously monitored wells in the Yucca Mountain Area, Nevada, 1989

    International Nuclear Information System (INIS)

    Water levels have been monitored hourly in 16 wells representing 24 intervals in the Yucca Mountain area, Nevada. Water levels were monitored using pressure transducers and were recorded by data loggers. The pressure transducers were periodically calibrated by raising and lowering them in the wells. The water levels were normally measured at approximately the same time that the transducers were calibrated. Where the transducer output appeared reasonable, it was converted to water levels using the calibrations and manual water-level measurements. The amount of transducer output that was converted to water levels ranged from zero for one interval to 100 percent for one interval. Fifteen of the wells were completed in Tertiary volcanic rocks and one well was completed in Paleozoic carbonate rocks. Each well monitored from one to four depth intervals. Water-level fluctuation caused by barometric pressure changes and earth tides were observed. Transducer output is presented in graphic form and, where appropriate, water-level altitude is presented in graphical and tabular form

  1. Global sea-level fluctuations during the Last Interglaciation (MIS 5e)

    Science.gov (United States)

    Hearty, Paul J.; Hollin, John T.; Neumann, A. Conrad; O'Leary, Michael J.; McCulloch, Malcolm

    2007-09-01

    The geomorphology and morphostratigraphy of numerous worldwide sites reveal the relative movements of sea level during the peak of the Last Interglaciation (Marine Isotope Stage (MIS) 5e, assumed average duration between 130±2 and 119±2 ka). Because sea level was higher than present, deposits are emergent, exposed, and widespread on many stable coastlines. Correlation with MIS 5e is facilitated by similar morphostratigraphic relationships, a low degree of diagenesis, uranium-thorium (U/Th) ages, and a global set of amino-acid racemization (AAR) data. This study integrates information from a large number of sites from tectonically stable areas including Bermuda, Bahamas, and Western Australia, and some that have experienced minor uplift (˜2.5 m/100 ka), including selected sites from the Mediterranean and Hawaii. Significant fluctuations during the highstand are evident at many MIS 5e sites, revealed from morphological, stratigraphic, and sedimentological evidence. Rounded and flat-topped curves derived only from reef tracts are incomplete and not representative of the entire interglacial story. Despite predictions of much different sea-level histories in Bermuda, the Bahamas, and Western Australia due to glacio- and hydro-isostatic effects, the rocks from these sites reveal a nearly identical record during the Last Interglaciation. The Last Interglacial highstand is characterized by several defined sea-level intervals (SLIs) that include: (SLI#1) post-glacial (MIS 6/5e Termination II) rise to above present before 130 ka; (SLI#2) stability at +2 to +3 m for the initial several thousand years (˜130 to ˜125 ka) during which fringing reefs were established and terrace morphology was imprinted along the coastlines; (SLI#3) a brief fall to near or below present around 125 ka; (SLI#4) a secondary rise to and through ˜+3-4 m (˜124 to ˜122 ka); followed by (SLI#5) a brief period of instability (˜120 ka) characterized by a rapid rise to between +6 to +9 m during which multiple notches and benches were developed; and (SLI#6) an apparently rapid descent of sea level into MIS 5d after 119 ka. U/Th ages are used to confirm the Last Interglacial age of the deposits, but unfortunately, in only two cases was it possible to corroborate the highstand subdivisions using radiometric ages. Sea levels above or at present were relatively stable during much of early MIS 5e and the last 6-7 ka of MIS 1, encouraging a comparison between them. The geological evidence suggests that significant oceanographic and climatic changes occurred thereafter, midway through, and continuing through the end of MIS 5e. Fluctuating sea levels and a catastrophic termination of MIS 5e are linked to the instability of grounded and marine-based ice sheets, with the Greenland (GIS) and West Antarctic (WAIS) ice sheets being the most likely contributors. Late MIS 5e ice volume changes were accompanied by oceanographic reorganization and global ecological shifts, and provide one ominous scenario for a greenhouse world.

  2. Fluctuations of local electric field and dipole moments in water between metal walls

    Science.gov (United States)

    Takae, Kyohei; Onuki, Akira

    2015-10-01

    We examine the thermal fluctuations of the local electric field Ek loc and the dipole moment ?k in liquid water at T = 298 K between metal walls in electric field applied in the perpendicular direction. We use analytic theory and molecular dynamics simulation. In this situation, there is a global electrostatic coupling between the surface charges on the walls and the polarization in the bulk. Then, the correlation function of the polarization density pz(r) along the applied field contains a homogeneous part inversely proportional to the cell volume V. Accounting for the long-range dipolar interaction, we derive the Kirkwood-Fröhlich formula for the polarization fluctuations when the specimen volume v is much smaller than V. However, for not small v/V, the homogeneous part comes into play in dielectric relations. We also calculate the distribution of Ek loc in applied field. As a unique feature of water, its magnitude | Ek loc | obeys a Gaussian distribution with a large mean value E0 ? 17 V/nm, which arises mainly from the surrounding hydrogen-bonded molecules. Since |?k|E0 ˜ 30kBT, ?k becomes mostly parallel to Ek loc . As a result, the orientation distributions of these two vectors nearly coincide, assuming the classical exponential form. In dynamics, the component of ?k(t) parallel to Ek loc ( t ) changes on the time scale of the hydrogen bonds ˜5 ps, while its smaller perpendicular component undergoes librational motions on time scales of 0.01 ps.

  3. Fluctuation of TeV to EeV Energy Muons and Induced Muon Showers in Water

    OpenAIRE

    Okumura, Y; N. Takahashi; Misaki{3], A.

    2010-01-01

    By using the integral method in the muon propagation through water, we calculate the range fluctuation of high and ultra high energy muons. Many authors divide all radiative processes into two parts, namely, the continuous part and radiative part in their Monte Carlo simulation in order to consider the fluctuation in the both ranges and energies of the muons, while we treat all stochastic processes as exactly as possible, without the introduction of the continuous parts in a...

  4. Fluctuating feather asymmetry in relation to corticosterone levels is sex-dependent in Eurasian treecreeper (Certhia familiaris) nestlings

    OpenAIRE

    Helle, Samuli; Suorsa, Petri; Huhta, Esa; Hakkarainen, Harri

    2010-01-01

    Fluctuating asymmetry (FA) has been widely used as a stress-related phenotypic marker of developmental instability. However, previous studies relating FA to various stressful conditions have produced inconsistent results and we still lack quantitative individual-level evidence that high FA is related to stress in wild vertebrate species. We studied how baseline plasma levels of corticosterone predicted FA of wing and tail feathers in free-living Eurasian treecreeper (Certhia familiaris) nestl...

  5. Potential Effects of Climate Change on the Water Level, Flora and Macro-fauna of a Large Neotropical Wetland

    OpenAIRE

    Úbeda, Bárbara; Di Giacomo, Adrian S.; Neiff, Juan José; Loiselle, Steven A.; Guadalupe Poi, Alicia S.; Gálvez, José Ángel; Casco, Silvina; Cózar, Andrés

    2013-01-01

    Possible consequences of climate change in one of the world’s largest wetlands (Ibera, Argentina) were analysed using a multi-scale approach. Climate projections coupled to hydrological models were used to analyse variability in wetland water level throughout the current century. Two potential scenarios of greenhouse gas emissions were explored, both resulting in an increase in the inter-annual fluctuations of the water level. In the scenario with higher emissions, projections also showed a l...

  6. Paleoclimatic significance of lake-level fluctuations in the Lahontan Basin*1

    Science.gov (United States)

    Benson, L. V.

    1981-11-01

    An energy flux balance model has been developed which treats evaporation as a function of air temperature, surface water temperature, precipitable water aloft, the amount, height, and type of sky cover, and the optical air mass. The model has been used to estimate the mean historical evaporation rate for Pyramid Lake, Nevada, using as input climatic data from the Reno area averaged over the period 1950-1975. Estimated and measured values of the mean annual evaporation rate were found to be in good agreement. The model was used to simulate changes in the level, the surface area, and the volume of paleo Lake Lahontan. In particular, possible climatic states responsible for past high stands (1270 and 1330 m) were investigated. A conservative range of discharge values was used in the calculations. Results of the simulations indicate the fundamental importance of sky cover in the creation and destruction of large lake systems.

  7. Fluctuations in Species-Level Protein Expression Occur during Element and Nutrient Cycling in the Subsurface

    OpenAIRE

    Wilkins, Michael J.; Wrighton, Kelly C; Nicora, Carrie D; Williams, Kenneth H.; McCue, Lee Ann; Handley, Kim M.; Miller, Chris S.; Giloteaux, Ludovic; Montgomery, Alison P; Lovley, Derek R.; Banfield, Jillian F.; Long, Philip E.; Lipton, Mary S

    2013-01-01

    While microbial activities in environmental systems play a key role in the utilization and cycling of essential elements and compounds, microbial activity and growth frequently fluctuates in response to environmental stimuli and perturbations. To investigate these fluctuations within a saturated aquifer system, we monitored a carbon-stimulated in situ Geobacter population while iron reduction was occurring, using 16S rRNA abundances and high-resolution tandem mass spectrometry proteome measur...

  8. Drinking Water Maximum Contaminant Levels (MCLs)

    Data.gov (United States)

    U.S. Environmental Protection Agency — National Primary Drinking Water Regulations (NPDWRs or primary standards) are legally enforceable standards that apply to public water systems. Primary standards...

  9. County Level Assessment of Impaired Waters and Gastrointestinal Infections

    Science.gov (United States)

    Water quality data are measured at a watershed level and health data are organized at different levels of aggregation therefore, assessing the population-level impact of water quality on health can be difficult. To address this discrepancy and enable the consideration of water ...

  10. A Simple Water Balance Approach to Monitor Lake Water Level Changes: Validation using TOPEX/Poseidon and Jason Altimetry Data

    Science.gov (United States)

    Velpuri, N.; Senay, G. B.; Alemu, H.; Asante, K. O.

    2008-12-01

    A simple water balance approach is adapted to monitor water resources in semi-arid region of east Africa by integrating coarse and dynamic datasets such as rainfall with fine and static elevation datasets. The model takes in Tropical Rainfall Measuring Mission (TRMM) rainfall data, modeled runoff and reference evapotranspiration (ET) data to monitor changes in lake water heights. Shuttle Radar Topography Mission Digital Elevation Model (SRTM DEM) was used to delineate lake Turkana watershed. A simple water balance modeling approach was applied on Turkana basin to estimate lake water level heights for ten years (1997- 2008) and the results were compared with TOPEX/Poseidon and Jason satellite altimeter data. It was observed that simple water balance approach could capture the trend and seasonal variations of lake water fluctuations as measured by the satellite. The El Nino year of 1998 and the following consecutive dry years until 2002 are captured well on both. A mean deviation up to 30 cm of lake water height was found when compared to the satellite measurements. The satellite measurements made since 2004 showed that the lake water height gradually reduced, whereas simulations made using the water balance model showed an increasing trend. This could be reasoned by the fact that, on the Omo river, which contributes to over 80% of the lake inflows, a dam was commissioned in 2004. Knowledge of such processes occurring upstream or downstream is often required while analyzing satellite altimetry data to avoid misinterpretation. Although the absolute accuracy is low, the advantage of the simple water balance method lies in its ability to: (i) capture the trend and seasonal variations of water level fluctuations of small to large lakes around the world; (ii) when coupled with ground measurements or satellite altimetry data for lake water heights, the simple water balance method can identify the presence and absence of upstream and downstream processes; (iii) since water balance approach gives water level variations assuming no flow regulating mechanisms, the simulations can be used to study the impact of climate change on the hydrology of the basin.

  11. Viscosity changes of riparian water controls diurnal fluctuations of stream-flow and DOC concentration

    Science.gov (United States)

    Schwab, Michael; Klaus, Julian; Pfister, Laurent; Weiler, Markus

    2015-04-01

    Diurnal fluctuations in stream-flow are commonly explained as being triggered by the daily evapotranspiration cycle in the riparian zone, leading to stream flow minima in the afternoon. While this trigger effect must necessarily be constrained by the extent of the growing season of vegetation, we here show evidence of daily stream flow maxima in the afternoon in a small headwater stream during the dormant season. We hypothesize that the afternoon maxima in stream flow are induced by viscosity changes of riparian water that is caused by diurnal temperature variations of the near surface groundwater in the riparian zone. The patterns were observed in the Weierbach headwater catchment in Luxembourg. The catchment is covering an area of 0.45 km2, is entirely covered by forest and is dominated by a schistous substratum. DOC concentration at the outlet of the catchment was measured with the field deployable UV-Vis spectrometer spectro::lyser (scan Messtechnik GmbH) with a high frequency of 15 minutes over several months. Discharge was measured with an ISCO 4120 Flow Logger. During the growing season, stream flow shows a frequently observed diurnal pattern with discharge minima in the afternoon. During the dormant season, a long dry period with daily air temperature amplitudes of around 10 ° C occurred in March and April 2014, with discharge maxima in the afternoon. The daily air temperature amplitude led to diurnal variations in the water temperature of the upper 10 cm of the riparian zone. Higher riparian water temperatures cause a decrease in water viscosity and according to the Hagen-Poiseuille equation, the volumetric flow rate is inversely proportional to viscosity. Based on the Hagen-Poiseuille equation and the viscosity changes of water, we calculated higher flow rates of near surface groundwater through the riparian zone into the stream in the afternoon which explains the stream flow maxima in the afternoon. With the start of the growing season, the viscosity induced diurnal effect is overlain by the stronger influence of evapotranspiration. Diurnal DOC fluctuations show daily maxima in the afternoon. While daily variations in DOC concentrations are often explained by faster in-stream biogeochemical processes during daylight, we here propose that the viscosity effect in the riparian zone could explain the afternoon peaks in DOC concentrations. Our records show that daily water temperature variations and therefore viscosity changes only occur in the near surface parts of the riparian zone, where the DOC concentrations are higher than in deeper parts of the riparian zone. We calculated, that the viscosity induced higher flow rates from the near surface parts of the riparian zone can explain the DOC concentration maxima in the afternoon. As the viscosity effect does not disappear during the growing season but is just smaller than the evapotranspiration effect, the DOC concentration pattern is not changing between the dormant and growing seasons. The different controls of diurnal fluctuations of stream-flow and water quality concentrations need to be carefully considered in order to better understand the different patterns in catchment hydrology.

  12. Portable Water Level Monitoring System via SMS

    Directory of Open Access Journals (Sweden)

    Jomar S. Vitales

    2015-11-01

    Full Text Available Damages and lives taken by the typhoon Ondoy and other super typhoons brought the researchers to think and develop a device that warns people an hour or more than an hour before the devastating phenomena. In this project the researchers have thought of using text messaging in which the country’s leading means of communication. The development of the project was guided by the Engineering Design Cycle of Dr. Allan Cheville in his book entitled “Rocket Engineering”. The researchers have identified and used the needed materials which are suited in the intended function of the project. The project was already evaluated and had gathered a favorable response from the knowledgeable respondents in the field where the design project is intended to use. The project has a high acceptability level in the respondents’ point of view. The researchers are highly recommending the implementation of the project for a better testing in the incoming rainy season and also recommending to be placed in the Pantalan Bridge in Pantalan, Nasugbu, Batangas, Philippines. The researchers are also suggesting another study for a better water proof casing of the project.

  13. Modern Risks of Anthropogenic Influence on Living Species: Nano-Level Fluctuation

    Science.gov (United States)

    Ruban, I.; Sharipov, M.; Voropaeva, N.; Magarshak, Yu.

    Taking into consideration oncoming global change, basic researches, concerning prospects of the use the modern methods of modeling in such important aspect as reactions of living organism on miscellaneous level hierarchy on risks, appearing as a result these change become exceedingly actual. Using different methods of modeling, generalized experimental material, we managed consider in detail some changes of the biological processes on different hierarchy levels (cellular, organism and population) in response to risks, appearing in ecosystems. In particular, processes of the shaping new desert in context of global desertification were modeled; possible mechanisms of speciation of living organism in radiation—chemical stress and mutation are described. The enzymes degradation models were worked out. On base of these experimental results the phenomena of negative geotropism of root system at influence of specifically dangerous xenobiotics (in particular, chlororganic) and thick water insoluble polymeric covering is considered. Besides, attempt of modeling of complex interaction in ecosystems in condition ecological crisis is realized. In spite of different levels of models, they, on our point of view, can illustrate the interaction of nanoworld with sharply changing condition of the environment and give the approaches to creation new technology. Consideration of these models is important and with standpoint of the estimation of risk and that difficulties, which faces the mankind at period of the oncoming global change of ecosystems under influence of different “on its nature” calls.

  14. Seasonal fluctuations in water repellency and infiltration in a sandy loam soil after a forest fire in Galicia (NW Spain

    Directory of Open Access Journals (Sweden)

    M. Rodríguez-Alleres

    2013-05-01

    Full Text Available The aim of this work was to analyze, after a wildfire of moderate severity, the temporal fluctuations in water repellency and infiltration in a sandy loam soil under a mixed plantation of pine and eucalyptus and the comparison with an adjacent area not affected by the fire. In the burnt area and in a neighboring area not affected by the fire were collected during one year (1, 4, 6, 8 and 12 months after the fire 10 soil samples along a transect of 18 m at four depths: 0-2, 2-5, 5-10 and 10-20 cm. Soil water repellency was determined using the water drop penetration time test (WDPT test and the infiltration was measured with a mini-disc infiltrometer (pressure head h0 = -2 cm.The results show a temporal pattern of soil water repellency in the burnt and unburnt areas. Significant correlations between water repellency and soil moisture were observed, with higher correlation coefficients in the unburned area and in the surface soil layer.Soil water infiltration was significantly lower than would be expected by the coarse texture of the soil in both burnt and unburnt areas. Temporal fluctuations in unburnt soil infiltration seem to be clearly related to the transient nature of the soil water repellency, with no infiltration in samples extremely repellent. In the burned area, the soil infiltration showed much more variability and temporal fluctuations appear to be less dependent on the persistence of water repellency and more dependent on environmental conditions.The unburnt area show significant and negative correlations of soil water repellency with hydraulic conductivity and sorptivity and positive of these two parameters with soil moisture. These relationships were not observed in the burnt area. The temporal fluctuations of soil water repellency have an evident impact on soil infiltration and seem to be more influent than the effects of fire.

  15. Historical impact of water infrastructure on water levels of the Mekong River and the Tonle Sap system

    Science.gov (United States)

    Cochrane, T. A.; Arias, M. E.; Piman, T.

    2014-11-01

    The rapid rate of water infrastructure development in the Mekong Basin is a cause for concern due to its potential impact on fisheries and downstream natural ecosystems. In this paper, we analyze the historical water levels of the Mekong River and Tonle Sap system by comparing pre- and post-1991 daily observations from six stations along the Mekong mainstream from Chiang Saen (northern Thailand), to Stung Treng (Cambodia), and the Prek Kdam station on the Tonle Sap River. Observed alterations in water level patterns along the Mekong are linked to temporal and spatial trends in water infrastructure development from 1960 to 2010. We argue that variations in historical climatic factors are important, but they are not the main cause of observed changes in key hydrological indicators related to ecosystem productivity. Our analysis shows that the development of mainstream dams in the upper Mekong Basin in the post-1991 period may have resulted in a modest increase of 30-day minimum levels (+17%), but significant increases in fall rates (+42%) and the number of water level fluctuations (+75%) observed in Chiang Saen. This effect diminishes downstream until it becomes negligible at Mukdahan (northeast Thailand), which represents a drainage area of over 50% of the total Mekong Basin. Further downstream at Pakse (southern Laos), alterations to the number of fluctuations and rise rate became strongly significant after 1991. The observed alterations slowly decrease downstream, but modified rise rates, fall rates, and dry season water levels were still quantifiable and significant as far as Prek Kdam. This paper provides the first set of evidence of hydrological alterations in the Mekong beyond the Chinese dam cascade in the upper Mekong. Given the evident alterations at Pakse and downstream, post-1991 changes could also be directly attributed to water infrastructure development in the Chi and Mun basins of Thailand. A reduction of 23 and 11% in the water raising and falling rates respectively at Prek Kdam provides evidence of a diminished Tonle Sap flood pulse in the post-1991 period. Given the observed water level alterations from 1991 to 2010 as a result of water infrastructure development, we can extrapolate that future development in the mainstream and the key transboundary Srepok, Sesan, and Sekong sub-basins will have an even greater effect on the Tonle Sap flood regime, the lower Mekong floodplain, and the delta.

  16. Water levels in the Yucca Mountain area, Nevada, 1993

    International Nuclear Information System (INIS)

    Water levels were monitored in 28 wells in the Yucca Mountain area, Nevada, during 1993. Seventeen wells were monitored periodically, generally on a monthly basis, and 11 wells representing 18 intervals were monitored hourly. All wells monitor water levels in Tertiary volcanic rocks, except one that monitors water levels in Paleozoic carbonate rocks. Water levels were measured using calibrated steel tapes and pressure transducers; steel-tape measurements were corrected for mechanical stretch, thermal expansion, and borehole deviation to obtain precise water-level altitudes. Water-level altitudes in the Tertiary volcanic rocks ranged from about 728 meters above sea level east of Yucca Mountain to about 1,034 meters above sea level north of Yucca Mountain. Water-level altitudes in the well monitoring the Paleozoic carbonate rocks varied between 752 and 753 meters above sea level during 1993. Water levels were an average of about 0.04 meter lower than 1992 water levels. All data were acquired in accordance with a quality-assurance program to support the reliability of the data

  17. Supersonic water level measuring method and device therefor

    International Nuclear Information System (INIS)

    In the present invention, water level can be measured stably irrespective of change of temperature distribution and flowing distribution of water in a pressure vessel or a tank of a nuclear reactor. Namely, sinusoidal supersonic waves are sent to a waveguide in contact with water to vibrate it. The water level is measured based on the change of the resonance state of the waveguide. Alternatively, sinusoidal supersonic waves are sent and received by a supersonic transducer. Resonance state of a waveguide in contact with water and connected to the supersonic transducer for propagating the supersonic waves is detected by way of the supersonic transducer. The water level is calculated based on the change of the resonance state. Since the resonance state of the waveguide member is free from the effects of temperature distribution and flowing distribution in water and gas, the water level can be measured at high accuracy irrespective of the temperature distribution and flowing distribution in water. (I.S.)

  18. Observing plants dealing with soil water stress: Daily soil moisture fluctuations derived from polymer tensiometers

    Science.gov (United States)

    van der Ploeg, Martine; de Rooij, Gerrit

    2014-05-01

    Periods of soil water deficit often occur within a plant's life cycle, even in temperate deciduous and rain forests (Wilson et al. 2001, Grace 1999). Various experiments have shown that roots are able to sense the distribution of water in the soil, and produce signals that trigger changes in leaf expansion rate and stomatal conductance (Blackman and Davies 1985, Gollan et al. 1986, Gowing et al. 1990 Davies and Zhang 1991, Mansfield and De Silva 1994, Sadras and Milroy 1996). Partitioning of water and air in the soil, solute distribution in soil water, water flow through the soil, and water availability for plants can be determined according to the distribution of the soil water potential (e.g. Schröder et al. 2013, Kool et al. 2014). Understanding plant water uptake under dry conditions has been compromised by hydrological instrumentation with low accuracy in dry soils due to signal attenuation, or a compromised measurement range (Whalley et al. 2013). Development of polymer tensiometers makes it possible to study the soil water potential over a range meaningful for studying plant responses to water stress (Bakker et al. 2007, Van der Ploeg et al. 2008, 2010). Polymer tensiometer data obtained from a lysimeter experiment (Van der Ploeg et al. 2008) were used to analyse day-night fluctuations of soil moisture in the vicinity of maize roots. To do so, three polymer tensiometers placed in the middle of the lysimeter from a control, dry and very dry treatment (one lysimeter per treatment) were used to calculate water content changes over 12 hours. These 12 hours corresponded with the operation of the growing light. Soil water potential measurements in the hour before the growing light was turned on or off were averaged. The averaged value was used as input for the van Genuchten (1980) model. Parameters for the model were obtained from laboratory determination of water retention, with a separate model parameterization for each lysimeter setup. Results show daily fluctuations in water content changes, with both root water uptake and root water excretion. The magnitude of the water content change was in the same order for all treatments, thus suggesting compensatory uptake. References Bakker G, Van der Ploeg MJ, de Rooij GH, Hoogendam CW, Gooren HPA, Huiskes C, Koopal LK and Kruidhof H. New polymer tensiometers: Measuring matric pressures down to the wilting point. Vadose Zone J. 6: 196-202, 2007. Blackman PG and Davies WJ. Root to shoot communication in maize plants of the effects of soil drying. J. Exp. Bot. 36: 39-48, 1985. Davies WJ and Zhang J. Root signals and the regulation of growth and development of plants in drying soil. Annu. Rev. Plant Physiol. Plant Mol. Biol. 42: 55-76, 1991. Gollan T, Passioura JB and Munns R. Soil water status affects the stomatal conductance of fully turgid wheat and sunflower leafs. Aust. J. Plant Physiol. 13: 459-464, 1986. Gowing DJG, Davies WJ and Jones HG. A Positive Root-sourced Signal as an Indicator of Soil Drying in Apple, Malus x domestica Borkh. J. Exp. Bot. 41: 1535-1540, 1990. Grace J. Environmental controls of gas exchange in tropical rain forests. In: Press, M.C, J.D. Scholes and M.G. Barker (ed.). Physiological plant ecology: the 39th Symposium of the British Ecological Society. Blackwell Science, United Kingdom, 1999. Kool D, Agam N, Lazarovitch N, Heitman JL, Sauer TJ, Ben-Gal A. A review of approaches for evapotranspiration partitioning. Agricultural and Forest Meteorology 184: 56- 70, 2014. Mansfield TA and De Silva DLR. Sensory systems in the roots of plants and their role in controlling stomatal function in the leaves. Physiol. Chem. Phys. & Med. 26: 89-99, 1994. Sadras VO and Milroy SP. Soil-water thresholds for the responses of leaf expansion and gas exchange: a review. Field Crops Res. 47: 253-266, 1996. Schröder N, Lazarovitch N, Vanderborcht J, Vereecken H, Javaux M. Linking transpiration reduction to rhizosphere salinity using a 3D coupled soil-plant model. Plant Soil 2013, doi: 10.1007/s11104-013-1990-8 Van der Ploeg MJ, Gooren HPA, Bakker G and de Rooij GH.

  19. Coarse Grained Normal Mode Analysis vs. Refined Gaussian Network Model for Protein Residue-Level Structural Fluctuations

    Science.gov (United States)

    Park, Jun-Koo; Jernigan, Robert; Wu, Zhijun

    2015-01-01

    We investigate several approaches to coarse grained normal mode analysis on protein residual-level structural fluctuations by choosing different ways of representing the residues and the forces among them. Single-atom representations using the backbone atoms C?, C, N, and C? are considered. Combinations of some of these atoms are also tested. The force constants between the representative atoms are extracted from the Hessian matrix of the energy function and served as the force constants between the corresponding residues. The residue mean-square-fluctuations and their correlations with the experimental B-factors are calculated for a large set of proteins. The results are compared with all-atom normal mode analysis and the residue-level Gaussian Network Model. The coarse-grained methods perform more efficiently than all-atom normal mode analysis, while their B-factor correlations are also higher. Their B-factor correlations are comparable with those estimated by the Gaussian Network Model and in many cases better. The extracted force constants are surveyed for different pairs of residues with different numbers of separation residues in sequence. The statistical averages are used to build a refined Gaussian Network Model, which is able to predict residue-level structural fluctuations significantly better than the conventional Gaussian Network Model in many test cases. PMID:23296997

  20. Climate change and recent water level variability in Patagonian proglacial lakes, Argentina

    Science.gov (United States)

    Pasquini, Andrea I.; Lecomte, Karina L.; Depetris, Pedro J.

    2008-10-01

    A long series of lakes (~ 150) borders the Patagonian Andes (south of ~ 38°S), most of which are a geomorphologic relict of Pleistocene glaciations. Employing instrumental records, we inspected lake water level departures from seasonal variations in seven proglacial lakes: Lacar, Mascardi, Steffen, Escondido, Puelo, Vinter, and Argentino. Lakes north of ~ 42°S show maximum gage (water) level during austral winter months; lakes between ~ 42° and ~ 45°S appear transitional; the one lake south of ~ 50°S (Argentino) shows maximum water level in early autumn. Most lakes show moderate level fluctuation throughout yearly records and, in general, show heteroscedacity. Furthermore, Hurst exponents reveal persistent behavior (i.e., long-term memory effect) in all water level series. In most lakes there are no trends in deseasonalized mean and maximum water levels (Seasonal Kendall test). Lake Mascardi-Manso River system (mostly fed by melt water from the retreating Manso Glacier) is a contrasting example that shows a decreasing trend during summer months that we ascribe to the also declining ice volume. Harmonic analysis (Fourier and wavelet transform) of deseasonalized mean and maximum water level time series shows interannual and decadal periodicities that we link to the occurrence of El Niño and/or the Antarctic Oscillation. The associated phase spectrum indicates that there is a ~ 13-month lag between ENSO occurrences and its effect on anomalous lake water levels. Increased snow accumulation during austral winters usually follows summertime El Niño events, which normally result in increased melt water volume that occurs with about one-year delay during the following (austral) spring/summer.

  1. Historical impact of water infrastructure on water levels of the Mekong River and the Tonle Sap System

    Directory of Open Access Journals (Sweden)

    T. A. Cochrane

    2014-04-01

    Full Text Available The rapid rate of water infrastructure development in the Mekong basin is a cause for concern due to its potential impact on fisheries and downstream natural ecosystems. In this paper we analyse the historical water levels of the Mekong River and Tonle Sap system by comparing pre and post 1991 daily observations from six stations along the Mekong mainstream from Chiang Sean (northern Laos, to Stung Treng (Cambodia, and the Prek Kdam station on the Tonle Sap River. Observed alterations in water level patterns along the Mekong are linked to temporal and spatial trends in water infrastructure development from 1960 to 2010. We argue that variations in historical climatic factors are important, but they are not the main cause of observed changes in key hydrological indicators related to ecosystem productivity. Our analysis shows that the development of mainstream dams in the upper Mekong basin in the post-1991 period have resulted in a significant increase of 7 day minimum (+91.6%, fall rates (+42%, and the number of water level fluctuations (+75 observed in Chiang Sean. This effect diminishes downstream until it becomes negligible at Mukdahan (northeast Thailand, which represents a drainage area of over 50% of the total Mekong Basin. Further downstream at Pakse (southern Laos, alterations to the number of fluctuations and rise rate became strongly significant after 1991. The observed alterations slowly decrease downstream, but modified rise rates, fall rates, and dry season water levels were still quantifiable and significant as far as Prek Kdam. This paper provides the first set of evidence of hydrological alterations in the Mekong beyond the Chinese dam cascade in the upper Mekong. Given the evident alterations with no precedence at Pakse and downstream, post-1991 changes can also be directly attributed to water infrastructure development in the Chi and Mun basins of Thailand. A reduction of 23 and 11% in the water raising and fall rates respectively at Prek Kdam provides evidence of a diminished Tonle Sap flood pulse in the post-1991 period. Given the observed water level alterations from 1991 to 2010 as a result of water infrastructure development, we can extrapolate that future development in the mainstream and the key transboundary Srepok, Sesan and Sekong subbasins will have an even greater effect on the Tonle Sap flood regime, the lower Mekong floodplain, and the delta.

  2. Soil migration and plant uptake of technetium from a fluctuating water table

    International Nuclear Information System (INIS)

    Soil columns (50 x 15 cm) were used to determine the potential for 95mTc (as a surrogate for 99Tc which is an important component of some radioactive waste) to migrate from a contaminated, fluctuating water table, through sandy loam soil and into perennial ryegrass. Upward migration was significantly retarded with, generally, only the bottom few centimetres of soil becoming contaminated over the 6 months of the experiment. This is thought to have been due to the presence of anoxic conditions within the water table leading to the reduction of pertechnetate to TcIV species which are relatively insoluble. However, some evidence of very slow upward migration over time was found. Only a small and inconsistent transfer of activity into the perennial ryegrass was observed. Whilst these observations would suggest that 99Tc is less important than radionuclides such as 129I and 36Cl in terms of the risk associated with radioactive waste disposal, the potential for a slow upward migration, and/or a pulse-release following the re-oxidation of reduced soil in which 99Tc has accumulated should not be overlooked

  3. Water level influences on body condition of Geophagus brasiliensis (Perciformes: Cichlidae in a Brazilian oligotrophic reservoir

    Directory of Open Access Journals (Sweden)

    Alejandra Filippo Gonzalez Neves dos Santos

    2004-09-01

    Full Text Available Effects of water level fluctuations on body condition of Geophagus brasiliensis were studied in a 30 km² Brazilian oligotrophic reservoir. Physiological condition (K and gonadosomatic index (GSI were compared according to water level (low and high. Females' best conditions were associated to higher resources availability during high water, since gonad development did not change between low and high water. Males' condition did not change between water levels, while the highest gonad development occurred in low water. Females presented higher reproductive investment than males, which allocated most of energy for somatic development. This strategy could be a mechanism to undergo the stress caused by oligotrophic characteristics of the reservoir enhanced during low water level.Efeitos do nível da água na condição de Geophagus brasiliensis foram analisados em um reservatório oligotrófico. A condição fisiológica (K e o índice gonadossomático (IGS foram comparados entre os níveis da água (baixo e alto. Melhores condições de fêmeas foram associadas a maiores disponibilidades de recursos no nível alto, já que o desenvolvimento gonadal não variou. Não foram registradas diferenças na condição de machos, contudo maiores valores de IGS ocorreram no nível baixo. Fêmeas apresentaram elevado investimento reprodutivo, enquanto machos investiram mais no desenvolvimento somático. Tal estratégia pode ser um mecanismo para suportar o estresse causado pelas características oligotróficas do reservatório, intensificadas durante o período de níveis baixos da água.

  4. Effects of water level regulation on littoral zone of lakes Konnivesi and Ruotsalainen

    International Nuclear Information System (INIS)

    Measures to develop an ecologically based regulation practice for the lakes Ruotsalainen and Konnivesi which belong to the Kymijoki watercourse, were undertaken in 1995, when the intermunicipal board for the Heinola health care centre and Myllykoski Oy proposed that the regulation licence should re-evaluated. The purpose of this study, which is part of the overall development project, was to assess the ecological impacts of regulation on the littoral zones of these lakes. More specifically, the study focussed on the changes in the ecology of the littoral zone due to the water level fluctuation. The littoral vegetation of lake Konnivesi reflects the improvement of water quality over the past fifteen years. The species indicative of eutrophication have mostly disappeared. The vegetation of the uppermost littoral zone has stabilised, and the effect of wave erosion is small Ice pressure on the bottom has hardly any impact on the plants sensitive to the ice scouring effect, because the ice-covered zone has actually been reduced in size consequent to the regulation. Owing to the small range of water level fluctuation during the open water period, the uppermost littoral zone remains very narrow, which restricts the spreading of especially helophytic vegetation. The narrow littoral zone impairs the development of the normal zonal biotope in many places and simultaneously prevents diverse increase of littoral biota. The aim of the ecological regulation practice proposed for Konnivesi is to ensure a water level favourable for pike spawning It is further proposed that the water level should decline by 25 cm during the open water period following the flood peak. This would help to widen the littoral zone suited to helophytic vegetation and to increase the vegetational diversity of especially gently sloping shores. (orig.) 12 refs

  5. Soil- and plant- water uptake in saline environments and their consequences to plant adaptation in fluctuating climates

    Science.gov (United States)

    Volpe, V.; Albertson, J. D.; Katul, G. G.; Marani, M.

    2010-12-01

    Ecological processes determining plant colonization are quite peculiar and competition among different species is governed by a set of unique adaptations to stress conditions caused by drought, hypoxic or hyper-saline conditions. These adaptations and possible positive feedbacks often lead to the formation of patterns of vegetation colonization and spatial heterogeneity (zonation), and play a primary role in the stabilization of sediments. It is these issues that frame the scope of this study. The main objective of this work is to track one of the fundamental pathways between plant adaptation (quantified in terms of physiological and ecological attributes such as leaf area or root density profile) and feedbacks (quantified by plant-mediated alterations to water availability and salinity levels): root water uptake. Because root-water uptake is the main conduit connecting transpiring leaves to reservoirs of soil water, the means by which salinity modifies the processes governing its two end-points and any two-way interactions between them serves as a logical starting point. Salinity effects on leaf transpiration and photosynthesis are first explored via stomatal optimization principles that maximize carbon gain at a given water loss for autonomous leaves. Salinity directly affects leaf physiological attributes such as mesophyll conductance and photosynthetic parameters and hence over-all conductance to transpiration as well as different strategies to cope with the high salinity (e.g. through salt seclusion, compartmentation and osmotic adjustments). A coupled model of subsurface flow based on a modified Richards’ equation that accounts for the effects of increasing salinity, anaerobic conditions, water stress and compensation factors is developed. Plant water uptake is considered as a soil moisture sink term with a potential rate dictated by the carbon demands of the leaves, and an actual rate that accounts for both - hydraulic and salinity limitations. Using this model, the root distribution shape function (e.g. constant, linear, exponential, or power-law) that optimally satisfies these carbon demands and simultaneous hydraulic and salinity constraints of the soil-root system is then determined for a set of forcing variables and boundary conditions. Adaptation speeds and feedback strengths to future climatic fluctuations are explored as ‘departures’ from this equilibrium profile state.

  6. Water Level Indicator with Alarms Using PIC Microcontroller

    Directory of Open Access Journals (Sweden)

    Ahmed Abdullah

    2015-07-01

    Full Text Available This paper shows a design of a water level indicator with PIC microcontroller. This design is applicable for both reservoir and main tank in home or industries.PIC 18F452 used in this design. There is also buzzer and LCD in this design. LCD used to show the level of water in both reservoir and main tank. Buzzer used to create a siren to stop the pump or water coming channel. There are 10 DIP switches used in this design. These switches indicate water level of both tanks. PIC microcontrollers also controls the motor which pumps the water in the tank from the reservoir. In the auto mode, motor is automatically turned on when water level reaches 20% in the tank and it is turned off when water level reaches 100%. Choose PIC microcontroller for programming flexibility, faster speed of execution since microcontrollers are fully integrated inside the processor

  7. Effects of Water Levels on Productivity of Canada Geese in the Northern Flathead Valley, Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Daniel

    1987-08-01

    The Fish and Wildlife Program of the Northwest Power Planning Council calls for wildlife mitigation at hydroelectric projects in the Columbia River System. Beginning April, 1984, the Bonneville Power Administration funded a study of the effects of the operation of Hungry Horse and Kerr Dams on the western Canada goose (Branta canadensis moffittii) inhabitating the Flathead Valley of northwest Montana. The study was conducted by personnel of the Montana Department of Fish, Wildlife and Parks (MDFWP), to: (1) identify the size and productivity of this population, (2) identify current habitat conditions and losses of nesting and brood-rearing areas, (3) describe the effects of water level fluctuations on nesting and brood-rearing, and (4) identify mitigation alternatives to offset these effects. Annual pair and nest surveys were used to document the location and fate of goose nests. The number of known nesting attempts varied from 44 in 1984 to 108 in 1985, to 136 in 1986 and 134 in 1987. Fifty-four percent of the annual meeting nesting effort took place on elevated sites which were secure from the flooding and dewatering effects of fluctuating water levels. An average of 15 nests were found on stumps in the remnant Flathead River delta, however, an area strongly influenced by the operation of Kerr Dam. Annual nest losses to flooding and predation attributable to fluctuations caused by the dam were recorded. 53 refs., 24 figs., 35 tabs.

  8. Water levels in the Yucca Mountain Area, Nevada, 1996

    International Nuclear Information System (INIS)

    Water levels were monitored in 24 wells in the Yucca Mountain area, Nevada, during 1996. Twenty-two wells representing 28 depth intervals were monitored periodically, generally on a monthly basis, and 2 wells representing 3 depth intervals were monitored both hourly and periodically. All wells monitor water levels in Tertiary volcanic rocks except one that monitors water levels in paleozoic carbonate rocks. Water levels were measured using either calibrated steel tapes or a pressure sensor. Mean water-level altitudes in the Tertiary volcanic rocks ranged from about 727.86 to about 1,034.58 meters above sea level during 1996. The mean water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 752.57 meters above sea level during 1996. Mean water-level altitudes for 1996 were an average of about 0.06 meter lower than 1995 mean water-level altitudes and 0.03 meter lower than 1985--95 mean water-level altitudes. During 1996, water levels in the Yucca Mountain area could have been affected by long-term pumping at the C-hole complex that began on May 8, 1996. Through December 31, 1996, approximately 196 million liters were pumped from well UE-25 c number-sign 3 at the C-hole complex. Other ground-water pumpage in the Yucca Mountain area includes annual pumpage from water-supply wells UE-25 J-12 and UE-25 J-13 of approximately 163 and 105 million liters, respectively, and pumpage from well USW G-2 for hydraulic testing during February and April 1996 of approximately 6 million liters

  9. Hydraulic Modeling of a Mixed Water Level Control Hydromechanical Gate

    OpenAIRE

    Cassan, Ludovic; Baume, Jean-Pierre; Belaud, Gilles; Litrico, Xavier; Malaterre, Pierre-Olivier; Ribot-Bruno, José

    2011-01-01

    This article describes the hydraulic behavior of a mixed water level control hydromechanical gate present in several irrigation canals. The automatic gate is termed "mixed" because it can hold either the upstream water level or the downstream water level constant according to the flow conditions. Such a complex behavior is obtained through a series of side tanks linked by orifices and weirs. No energy supply is needed in this regulation process. The mixed flow gate is analyzed and a mathemati...

  10. Stratigraphic analysis of lake level fluctuations in Lake Ohrid: an integration of high resolution hydro-acoustic data and sediment cores

    OpenAIRE

    Lindhorst, K.; Vogel, H.(); Krastel, S.; Wagner, B.; A. Hilgers; Zander, A.; Schwenk, T.; Wessels, M.; Daut, G.

    2010-01-01

    Ancient Lake Ohrid is a steep sided, oligotrophic, karst lake of likely Pliocene age and often referred to as a hotspot of endemic biodiversity. This study aims on tracing significant lake level fluctuations at Lake Ohrid using high-resolution acoustic data in combination with lithological, geochemical, and chronological information from two sediment cores recovered from sub-aquatic terrace levels at ca. 32 and 55 m. According to our data, significant lake level fluctuations with prominent lo...

  11. Water levels in the Yucca Mountain area, Nevada, 1995

    International Nuclear Information System (INIS)

    Water levels were monitored in 28 wells in the Yucca Mountain area, Nevada, during 1995. Seventeen wells representing 18 depth intervals were monitored periodically, generally on a monthly basis, 2 wells representing 3 depth intervals were monitored hourly, and 9 wells representing 15 depth intervals were monitored both periodically and hourly. All wells monitor water levels in Tertiary volcanic rocks except one that monitors water levels in Paleozoic carbonate rocks. Water levels were measured using calibrated steel tapes, a multiconductor cable unit, and/or pressure transducers. Mean water-level altitudes in the Tertiary volcanic rocks ranged from about 728 to about 1,034 meters above sea level during 1995. The mean water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 753 meters above sea level during 1995. Mean water level altitudes were only an average of about 0.01 meters higher than 1994 mean water level altitudes. A single-well aquifer test was conducted on well UE-25 WT number-sign 12 during August and September 1995. Well USW 0-2 was also pumped during October and November 1995, in preparation for single-well aquifer test at that well. All data were acquired in accordance with a quality-assurance program to support the reliability of the data

  12. Water levels in the Yucca Mountain area, Nevada, 1994

    International Nuclear Information System (INIS)

    Water levels were monitored in 28 wells in the Yucca Mountain area, Nevada, during 1994. Twelve wells representing 13 intervals were monitored periodically, generally on a monthly basis, 6 wells representing 10 intervals were monitored hourly, and 10 wells representing 13 intervals were monitored both periodically and hourly. All wells monitor water levels in Tertiary volcanic rocks, except one, that monitors water levels in Paleozoic carbonate rocks. Water levels were measured using calibrated steel tapes, a multiconductor cable unit, and pressure transducers. Water-level altitudes in the Tertiary volcanic rocks ranged from about 728 to about 1,034 meters above sea level during 1994. The mean-annual water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 753 meters above sea level during 1994. Water levels were only an average of about 0.01 meters lower than 1993 water levels. All data were acquired in accordance with a quality-assurance program to support the reliability of the data

  13. Combination of soil-water balance models and water-table fluctuation methods for evaluation and improvement of groundwater recharge calculations

    Science.gov (United States)

    Jie, Zhang; van Heyden, Jan; Bendel, David; Barthel, Roland

    2011-12-01

    Despite a long history of related research, quantifying and verifying recharge is still a major challenge. The combination and comparison of conceptually different methods has been recommended as a strategy for evaluating recharge estimates. In this article, recharge estimates from water-table fluctuation (WTF) methods are combined with and compared to the results of the spatially and temporally discretized soil-water-balance model PROMET (processes of radiation, mass and energy transfer). As PROMET and WTF methods rely on different measurable variables, a comparison of these two contrasting techniques allows improved assessment of the plausibility of recharge estimates. An enhanced approach to WTF methods is presented. The approach assumes that in the case of no recharge, there exists a maximum possible potential decline for any given groundwater level. The primary conclusion is that WTF methods are excellent for determining the plausibility of spatially distributed regional-groundwater-recharge estimation approaches and for detecting inconsistencies in available models. Recharge estimates derived from WTF approaches alone are, however, not suitable for regional-scale recharge estimation due to (1) their strong dependency on local data, applicability of which is limited to only very specific conditions, and (2) their sensitivity to influences other than recharge.

  14. Study on the RPV depressurization for ATWS with RPV water level unknown using MAAP5 codes

    International Nuclear Information System (INIS)

    MAAP5(Modular Accident Analysis Program Rev. 5.0.0), developed by Fauske and Associates, Inc.'s (FAI) based on the MAAP4 code, is a severe accident analysis code. It is a computer program capable of simulating the response and mitigation actions of light water reactor nuclear power plants (NPPs), including advanced boiling water reactor (ABWR) during severe accident. The effectiveness of the execution of emergency operation procedures (EOPs) for an advanced boiling water reactor (ABWR) during postulated accident conditions using MAAP5 code is discuss in this paper. The simulation scenarios included the loss of feedwater pumps and turbine driven Core Isolation Cooling System (RCIC), the anticipated transient without scram (ATWS), and loss of reactor pressure vessel (RPV) water level indication. Based on the comparisons of responses on different parameters for cases with and without EOP actions, we concluded the RPV emergency depressurization (ED) in the EOP could effectively mitigate the consequences of the accident. The simulation clearly reveal that the execution of ED for the condition of RPV water level unknown could reduce primary containment pressure, suppression pool temperature, and avoid large fluctuation of RPV pressure, water level, and core power. For the RPV level unknown under ATWS condition, RPV ED can give the operator the easier way to control RPV pressure, and to assure adequate core cooling. (author)

  15. Analysis of water level control methods for nuclear steam generator

    International Nuclear Information System (INIS)

    Nuclear steam generator (SG) is a highly complex nonlinear time-changed system. The inverse dynamics effects, which are caused by shrink and swell under transient, startup and lower power operation, make the water level difficult to control. Methods of SG water level control are analyzed. The shortcoming of conventional PI(D) control for SG level is pointed out. It emphatically expounds the fuzzy logic control and the neural network control to nuclear steam generator level. Finally, the author brings forward his opinion upon the advance tendency of SG water level control. (authors)

  16. EFECTOS DE LA FLUCTUACIÓN DEL NIVEL DEL AGUA SOBRE LA ESTRUCTURA DEL ENSAMBLAJE DE ROTÍFEROS EN EL LAGO LARGO (SISTEMA YAHUARCACA - LLANURA DE INUNDACIÓN DEL RÍO AMAZONAS - COLOMBIA) / Effects of water level fluctuation on rotifers assemblage structure in Largo lake (Yahuarcaca sistem - river Amazon floodplain - Colombia)

    Scientific Electronic Library Online (English)

    CAMILO, ANDRADE-SOSSA; MIGDALIA, GARCÍA-FOLLECO; CARLOS A., RODRÍGUEZ-MUNAR; SANTIAGO R., DUQUE; EMILIO, REALPE.

    2011-12-30

    Full Text Available Se realizó un reconocimiento taxonómico y estimación de la densidad en el ensamblaje de rotíferos en el lago Largo, del sistema de lagos Yahuarcaca, en la ribera colombiana del río Amazonas, a partir de muestreos en las fases hidrológicas de aguas bajas, ascenso y descenso. Se identificaron 68 espec [...] ies, 28 de ellas son nuevos registros para ambientes colombianos. Se encontró aumento en la riqueza en las épocas de ascenso y descenso, siendo mayor en la zona litoral respecto de la limnética, y la tendencia a mayor similitud taxonómica entre ambas zonas en el periodo de aguas bajas, debido al mínimo desarrollo de macrófitas en esta fase y la consecuente menor heterogeneidad espacial. Se observó el predominio de rotíferos con trofi adaptados para moler y triturar partículas (maleado y maleorramado) en las épocas de aguas bajas (Brachionus ahlstromi) y descenso (Filina saltator) y en la época de ascenso de Polyarthra vulgaris, con trofi adaptado para perforar y succionar fluidos de algas y otros organismos (virgado) y apéndices que favorecen la rápida natación. En general, se establecieron posibles relaciones entre la riqueza y la densidad de rotíferos con cambios en características como el desarrollo de vegetación acuática en el litoral, profundidad del lago, nivel de conectividad con los otros lagos del sistema Yahuarcaca, influencia de aguas blancas del Amazonas y negras de origen local, potenciales recursos nutricionales y depredadores, y posible efecto de arrastre por la corriente. Abstract in english We conducted a taxonomic recognition and density estimation of the assemblage of rotifers in Lake Largo, in the floodplain system of Yahuarcaca, connected with the Amazon River, in Colombia. Two samplings were made for each hydrological phase (low water, filling and draining phases); 68 species were [...] identified, 28 of them are new records for Colombian environments. We found an increased in species richness in the filling and draining phases, being higher in the littoral than in limnetic region, and a tendency to a higher taxonomic similarity between the two areas during low water periods, due to the reduced macrophyte development in that period and consequent reduced spatial heterogeneity. We observed the predominance of rotifers with trophi adapted for grinding and crushing particles (malleate and malleorramate) in low water phase (Brachionus ahlstromi) and draining phase (Filina saltator) and Polyarthra vulgaris, with a trophi adapted to pierce and suck out the fluids of algae and other organisms (virgate), and appendices that support the rapid swimming, at the filling phase. In general, we established possible relations between rotifers richness and density with changes in characteristics as the development of aquatic vegetation in the littoral zone, lake depth, level of connectivity with other lakes of Yahuarcaca system, level of influence of white waters from the Amazon river, and black waters from local origin, potentials nutritional resources and predators, and drag effect by the current.

  17. Synthesis water level control by fuzzy logic

    OpenAIRE

    Berk, P.; D. Stajnko; P. Vindis; B. Mursec; M. Lakota

    2011-01-01

    Purpose: This paper focuses on evolving of two types fuzzy and classical PID liquid level controller and examining whether they are better able to handle modelling uncertainties. A two stage strategy is employed to design the synthesis fuzzy and classical PID controller with the process of the first and second order and implements disorder (quadratic function).Design/methodology/approach: The synthesis of fuzzy and classical PID liquid level controller was realized with the HP laptop 6830s Co...

  18. Characteristic of water level changes in river-bed during the 2012 drought in context of ground water levels in a small catchment

    Science.gov (United States)

    Wasilewicz, Micha?; Kaznowska, Ewa; Hejduk, Leszek

    2014-05-01

    The objective of this paper is to characterize the water level changes in river bed during the 2012 drought, in the context of ground water levels in the catchment. During the growing season , and long- lasting lack of precipitation causes atmospheric drought. Prolonged lack of precipitation causes depletion of water resources in the saturated zone . Groundwater recharge of rivers decreases , and hence streamflow droughts (summer droughts) occur, which is identified as hydrological droughts. In the phase of hydrological drought a much stronger relationship between surface and ground waters is observed. The study area is the Zago?d?onka river. The Zago?dzonka catchment is situated in the strip of the Central Polish Lowlands, in the region where droughts are the most frequent. The basin is the research area of the Department of Hydraulic Engineering of WUoLS-SGGW in Warsaw. It is one of the few catchments in Poland, with long-term records of rainfall and runoff occurrences. Hydrometeorological measurements are carried out from July 1962. The catchment area is mainly covered by one Quaternary aquifer . Quaternary layer is composed mostly of Pleistocene sands and gravels, with thickness from 4 to 40 m. Aquifer is at a depth of 1 to 12 m below ground level and is unconfined and fed by direct infiltration of precipitation. The Zago?d?onka river is the main drainage in the local hydrologic cycle. There is a strong relationship between surface waters and occurring in the Quaternary sediments. In the hydrological year 2012 hydrological and atmospheric drought occurred. The duration and deficit of streamflow drought ( defined by with the Q90 % truncation level) in 2012 was three time greater than the average value from the multi-annual period, which influenced the groundwater level fluctuations. Acknowledgment The paper has been prepared with financial support by a grant from National Science Centre

  19. Sensitivity of polarization fluctuations to the nature of protein-water interactions: study of biological water in four different protein-water systems.

    Science.gov (United States)

    Ghosh, Rikhia; Banerjee, Saikat; Hazra, Milan; Roy, Susmita; Bagchi, Biman

    2014-12-14

    Since the time of Kirkwood, observed deviations in magnitude of the dielectric constant of aqueous protein solution from that of neat water (?80) and slower decay of polarization have been subjects of enormous interest, controversy, and debate. Most of the common proteins have large permanent dipole moments (often more than 100 D) that can influence structure and dynamics of even distant water molecules, thereby affecting collective polarization fluctuation of the solution, which in turn can significantly alter solution's dielectric constant. Therefore, distance dependence of polarization fluctuation can provide important insight into the nature of biological water. We explore these aspects by studying aqueous solutions of four different proteins of different characteristics and varying sizes, chicken villin headpiece subdomain (HP-36), immunoglobulin binding domain protein G (GB1), hen-egg white lysozyme (LYS), and Myoglobin (MYO). We simulate fairly large systems consisting of single protein molecule and 20000-30000 water molecules (varied according to the protein size), providing a concentration in the range of ?2-3 mM. We find that the calculated dielectric constant of the system shows a noticeable increment in all the cases compared to that of neat water. Total dipole moment auto time correlation function of water ??MW(0)?MW(t)? is found to be sensitive to the nature of the protein. Surprisingly, dipole moment of the protein and total dipole moment of the water molecules are found to be only weakly coupled. Shellwise decomposition of water molecules around protein reveals higher density of first layer compared to the succeeding ones. We also calculate heuristic effective dielectric constant of successive layers and find that the layer adjacent to protein has much lower value (?50). However, progressive layers exhibit successive increment of dielectric constant, finally reaching a value close to that of bulk 4-5 layers away. We also calculate shellwise orientational correlation function and tetrahedral order parameter to understand the local dynamics and structural re-arrangement of water. Theoretical analysis providing simple method for calculation of shellwise local dielectric constant and implication of these findings are elaborately discussed in the present work. PMID:25494802

  20. Sensitivity of polarization fluctuations to the nature of protein-water interactions: Study of biological water in four different protein-water systems

    Science.gov (United States)

    Ghosh, Rikhia; Banerjee, Saikat; Hazra, Milan; Roy, Susmita; Bagchi, Biman

    2014-12-01

    Since the time of Kirkwood, observed deviations in magnitude of the dielectric constant of aqueous protein solution from that of neat water (˜80) and slower decay of polarization have been subjects of enormous interest, controversy, and debate. Most of the common proteins have large permanent dipole moments (often more than 100 D) that can influence structure and dynamics of even distant water molecules, thereby affecting collective polarization fluctuation of the solution, which in turn can significantly alter solution's dielectric constant. Therefore, distance dependence of polarization fluctuation can provide important insight into the nature of biological water. We explore these aspects by studying aqueous solutions of four different proteins of different characteristics and varying sizes, chicken villin headpiece subdomain (HP-36), immunoglobulin binding domain protein G (GB1), hen-egg white lysozyme (LYS), and Myoglobin (MYO). We simulate fairly large systems consisting of single protein molecule and 20000-30000 water molecules (varied according to the protein size), providing a concentration in the range of ˜2-3 mM. We find that the calculated dielectric constant of the system shows a noticeable increment in all the cases compared to that of neat water. Total dipole moment auto time correlation function of water ??MW(0)?MW(t)? is found to be sensitive to the nature of the protein. Surprisingly, dipole moment of the protein and total dipole moment of the water molecules are found to be only weakly coupled. Shellwise decomposition of water molecules around protein reveals higher density of first layer compared to the succeeding ones. We also calculate heuristic effective dielectric constant of successive layers and find that the layer adjacent to protein has much lower value (˜50). However, progressive layers exhibit successive increment of dielectric constant, finally reaching a value close to that of bulk 4-5 layers away. We also calculate shellwise orientational correlation function and tetrahedral order parameter to understand the local dynamics and structural re-arrangement of water. Theoretical analysis providing simple method for calculation of shellwise local dielectric constant and implication of these findings are elaborately discussed in the present work.

  1. Current-induced two-level fluctuations in pseudo spin-valves (Co/Cu/Co) nanostructures

    OpenAIRE

    Fabian, A.; Terrier, C.; Guisan, S. Serrano; Hoffer, X.; M. Dubey; Gravier, L.; Ansermet, J.-Ph.; Wegrowe, J. - E.

    2003-01-01

    Two-level fluctuations of the magnetization state of pseudo spin-valve pillars Co(10 nm)/Cu(10 nm)/Co(30 nm) embedded in electrodeposited nanowires (~40 nm in diameter, 6000 nm in length) are triggered by spin-polarized currents of 10^7 A/cm^2 at room temperature. The statistical properties of the residence times in the parallel and antiparallel magnetization states reveal two effects with qualitatively different dependences on current intensity. The current appears to have ...

  2. Animating ground water levels with Excel.

    Science.gov (United States)

    Shikaze, Steven G; Crowe, Allan S

    2003-01-01

    This note describes the use of Microsoft Excel macros (programs written in Excel's internal language, Visual Basic for Applications) to create simple onscreen animations of transient ground water data within Excel. Compared to many specialized visualization software packages, the use of Excel macros is much cheaper, much simpler, and can rapidly be learned. The Excel macro can also be used to create individual GIF files for each animation frame. This series of frames can then be used to create an AVI video file using any of a number of graphics packages, such as Corel PhotoPaint. The technique is demonstrated through a macro that animates changes in the elevation of a water table along a transect over several years. PMID:12873018

  3. Keeping fuel covered. ABB's new water level measurement system

    International Nuclear Information System (INIS)

    As one of the basic principles of reactor safety is to ensure that the fuel is covered, knowing water levels is vital. Older designs of water measurement equipment can suffer errors caused by the presence of non-condensable gases in the water during a depressurization transient. ABB Atom's new level measuring system, which uses an advanced condensation pot, is virtually independent of any variation of gas content. (UK)

  4. Analysis of Ground-Water Levels and Associated Trends in Yucca Flat, Nevada Test Site, Nye County, Nevada, 1951-2003

    Energy Technology Data Exchange (ETDEWEB)

    J.M. Fenelon

    2005-10-05

    Almost 4,000 water-level measurements in 216 wells in the Yucca Flat area from 1951 to 2003 were quality assured and analyzed. An interpretative database was developed that describes water-level conditions for each water level measured in Yucca Flat. Multiple attributes were assigned to each water-level measurement in the database to describe the hydrologic conditions at the time of measurement. General quality, temporal variability, regional significance, and hydrologic conditions are attributed for each water-level measurement. The database also includes narratives that discuss the water-level history of each well. Water levels in 34 wells were analyzed for variability and for statistically significant trends. An attempt was made to identify the cause of many of the water-level fluctuations or trends. Potential causes include equilibration following well construction or development, pumping in the monitoring well, withdrawals from a nearby supply well, recharge from precipitation, earthquakes, underground nuclear tests, land subsidence, barometric pressure, and Earth tides. Some of the naturally occurring fluctuations in water levels may result from variations in recharge. The magnitude of the overall water-level change for these fluctuations generally is less than 2 feet. Long-term steady-state hydrographs for most of the wells open to carbonate rock have a very similar pattern. Carbonate-rock wells without the characteristic pattern are directly west of the Yucca and Topgallant faults in the southwestern part of Yucca Flat. Long-term steady-state hydrographs from wells open to volcanic tuffs or the Eleana confining unit have a distinctly different pattern from the general water-level pattern of the carbonate-rock aquifers. Anthropogenic water-level fluctuations were caused primarily by water withdrawals and nuclear testing. Nuclear tests affected water levels in many wells. Trends in these wells are attributed to test-cavity infilling or the effects of depressurization following nuclear testing. The magnitude of the overall water-level change for wells with anthropogenic trends can be large, ranging from several feet to hundreds of feet. Vertical water-level differences at 27 sites in Yucca Flat with multiple open intervals were compared. Large vertical differences were noted in volcanic rocks and in boreholes where water levels were affected by nuclear tests. Small vertical differences were noted within the carbonate-rock and valley-fill aquifers. Vertical hydraulic gradients generally are downward in volcanic rocks and from pre-Tertiary clastic rocks toward volcanic- or carbonate-rock units.

  5. Intraocular pressure fluctuation in healthy and glaucomatous eyes: a comparative analysis between diurnal curves in supine and sitting positions and the water drinking test

    Directory of Open Access Journals (Sweden)

    Rafael Ramos Caiado

    2014-10-01

    Full Text Available Purpose: To compare intraocular pressure (IOP using the simplified daily tensional curve (SDTC between supine and sitting positions in terms of peak levels and amount of fluctuation in both, glaucomatous and healthy subjects. The secondary endpoint was the comparison of these measures with those derived from the water drinking test (WDT. Methods: Thirty patients with primary open-angle glaucoma (POAG that were undergoing medical therapy and 30 healthy subjects were enrolled in this study. Each patient underwent a diurnal curve between 8 am and 4 pm. After lying down for 5 minutes, the IOP was measured with the Perkins tonometer. Patients were instructed to sit in the upright position for 5 minutes and the tonometry was repeated. At 4:15 pm, the WDT test was performed. Fluctuation was defined as the difference between the highest and the lowest IOP readings (range. The Student's t test was used to assess differences and a P value <0.05 was considered to be statistically significant. Results: The diurnal curve in the supine position demonstrated higher IOP average values (on average 3-4 mmHg higher compared to the sitting position (p<0.0001 for both groups. IOP peaks were higher in the supine position; however, the IOP range was essentially the same between the three methods. Treated glaucomatous patients had higher IOP levels in all measurements, but the fluctuation for all tests performed appeared to be similar to that of healthy patients. Conclusion: The data suggested that WDT can be used to estimate the diurnal IOP peak and fluctuation observed in the SDTC of the supine position for treated glaucomatous patients. Further studies can compare the possible correlation between the WDT results and those obtained from nocturnal supine measurements.

  6. Climate-driven changes in water level

    DEFF Research Database (Denmark)

    Hansen, Rikke Bjerring; Olsen, Jesper; Jeppesen, Erik; Buchardt, Bjørn; Heinemeier, Jan; McGowan, Suzanne; Leavitt, Peter R.; Enevold, Renée; Odgaard, Bent Vad

    2013-01-01

    A two-stage change in lake level during the 8.2-ka event was identified in Lake Sarup, Denmark (55A degrees N), using a multiproxy approach on precise radiocarbon wiggle-matched annually laminated sediments deposited 8740-8060 cal. yr BP. Changes in delta C-13 and delta O-18 indicated closed lake hydrology driven by precipitation. The isotopic, sedimentary and plant macrofossil records suggested that the lake level started to decrease around 8400 cal. yr BP, the decrease accelerating during 8350...

  7. Long-term fluctuations of water resources availability and its implications for a sustainable management of arid agricultural coastal regions

    Science.gov (United States)

    Grundmann, Jens; Schütze, Niels

    2015-04-01

    Freshwater scarcity and ongoing population growth associated with increasing water demands are major challenges for water management in coastal arid regions. Excessive use of groundwater for irrigation in agriculture puts those regions at risk of saltwater intrusion which limits agricultural opportunities. Additionally, some arid regions are characterised by a cyclic climate in which longer periods of dry years are followed by longer periods of wet years. This results also in long-term fluctuations of groundwater replenishment rates and water resources availability which may reach the same order of magnitude like long-term average values. Therefore, these long-term fluctuations should be considered for water resources management planning and operation. In order to evaluate their impact a simulation-based integrated water management system for coastal arid regions is used. The management system couples a groundwater module, assessing the water resources availability, and an agricultural module, controlling irrigation and cultivation within an optimisation module which allow for multi-objective optimisation of the water management regarding profitable and sustainable water resources and agricultural management on farm and regional scale. To achieve a fast and robust operation of the water management system, surrogate models are used which emulate the behaviour of physically based process models and a hierarchical optimisation scheme is applied. The water management system is driven by different scenarios of the water resources availability which were generated by using time series analyses and modelling of local groundwater replenishment rates. An application is performed for the south Batinah coastal region in the Sultanate of Oman which is affected by saltwater intrusion into a coastal aquifer system due to excessive groundwater withdrawal for irrigated agriculture. Several scenarios of water resources availability are used to compare long-term and adaptive management strategies and to demonstrate and to evaluate the impact of climate variability regarding agricultural profit and sustainable aquifer management.

  8. WATER-LEVEL MONITOR FOR BOREWELL AND WATER TANK BASED ON GSM

    OpenAIRE

    Ramani, R.; S.Selvaraju; S.VALARMATHY; R.Thangam; B.Rajasekaran

    2012-01-01

    Now a days, home automation & remote control and monitoring systems have seen a rapid growth in terms of technology. Apparently there is no early warning system to monitor the tank water level and bore well water level when it has reached the critical level. In this paper we have provided water level monitoring in the tank as well as in the bore well. If the water level in a bore well drops below the threshold level for pumping its pump motor may get air locked or more burn out due to dry run...

  9. Experimental study of the fluctuations of an upward air-water flow in the circular pipe

    International Nuclear Information System (INIS)

    Among all the interactions between fluids and mechanical structures, the author is in particular interested in decoupled random excitations due to a two-phase flow on a transverse mechanical structure. The aim of this work is to know the parameters of the two-phase flow which drive the excitation forces of the vibrational modes of these structures. The fluctuations of an upward bubble two-phase flow have been studied in a cylindrical pipe with and without barrier(s). Three measurements techniques have been used to determine the mean characteristics of the flow and the fluctuations of the liquid mass flux and of the liquid movement quantity (nuclear magnetic resonance), of the local void fraction (optical probe) and of the wall pressure (piezoelectric sensor). The obtained results show that the fluctuations of the mass fluxes and of the liquid movement quantities are mainly driven by the fluctuations of the surface void fractions and particularly when the mean void fraction is great. Similarly, the pressure fluctuations are strongly influenced by the surface void fraction fluctuations. In the case of a barrier context, an instability phenomenon, inducing a sudden rise of the void fraction fluctuations in the range of the mean void fraction between 5 and 20 per cent, has been observed. The presence of grids leads to the formation of strong amplitude peaks of the pressure spectra. The study on the evolution of these peaks in terms of gas and liquid velocities implies that the pressure fluctuations, caused by the phenomenon of releases of these two-phase flows, are mainly controlled by the velocity of this mixture and by the fluctuations of the surface void fraction. (author)

  10. Synthesis water level control by fuzzy logic

    Directory of Open Access Journals (Sweden)

    P. Berk

    2011-04-01

    Full Text Available Purpose: This paper focuses on evolving of two types fuzzy and classical PID liquid level controller and examining whether they are better able to handle modelling uncertainties. A two stage strategy is employed to design the synthesis fuzzy and classical PID controller with the process of the first and second order and implements disorder (quadratic function.Design/methodology/approach: The synthesis of fuzzy and classical PID liquid level controller was realized with the HP laptop 6830s Compaq NA779ES, software Matlab/Simulink 2008b, FIS (Fuzzy Inference System soft logical tool, input-output unit 500 Dragon Rider and ultrasonic sensor. Using the simulation program Matlab/Simulink/FIS we simulate the operation of fuzzy and classical controller in the liquid level regulating cycle and made a comparison between fuzzy and classical controller functioning.Findings: From the responses to step fuzzy and classical controller for first-order process shows that the actual value of the controlled variable takes the value one. Fuzzy and classical PID controller does not allow control derogation, which is also inappropriate for fuzzy and classical control cycle with incorporating disturbance. Classical PID controller in the first-order process provides short-term regulation, such as fuzzy PID controller. In fuzzy control cycle with fuzzy PID controller and incorporating disturbance in the process of second-order the control cycle is stable and at certain predetermined parameters (integral gain a control does not allow deviations.Research limitations/implications: In future research, the robustness of the fuzzy logic controller will be investigated in more details.Practical implications: Using fuzzy liquid level controller can reduce power consumption by 25%. Originality/value: Fuzzy logic controller is useful in applications of nonlinear static characteristic, where classical methods with usually classical PID controllers cannot be a satisfactory outcome

  11. Correlation between central corneal thickness and intraocular pressure peak and fluctuation during the water drinking test in glaucoma patients

    Directory of Open Access Journals (Sweden)

    Rafael Lacerda Furlanetto

    2010-01-01

    Full Text Available OBJECTIVE: To investigate the correlation between central corneal thickness and outflow facility assessed by intraocular pressure peak and fluctuation during the water drinking test. METHODS: Fifty-five newly diagnosed primary open-angle glaucoma patients submitted to central corneal thickness measurements and water drinking test were enrolled in this retrospective study.;. Patients were divided into three groups according to their central corneal thickness. Pearson's Correlation test was performed in the groups with lower and higher pachymetric values. RESULTS: The mean age was 65,65 ± 28,28 years; 63,63% were female and 52,72% were caucasian. The mean central corneal thickness was 544,32 ± 36,86 µm, and the mean baseline intraocular pressure was 23,36 ± 6,26 mmHg. During the water drinking test, the mean intraocular pressure peak and mean intraocular pressure fluctuation were 30,43 ± 8,13 mmHg and 31,46 ± 18,46%, respectively. No relevant correlation was detected between the central corneal thickness and the intraocular pressure peak (r² = 0,021 or between the central corneal thickness and the intraocular pressure fluctuation (r² = 0,011. Group 1 presented a mean central corneal thickness of 505,81 ± 13,86 µm, and Group 3 was 583,55 ± 27,87 µm (p = 0,001. The mean intraocular pressure peak was 31,05 ± 9,05 mmHg and 27,83 ± 4,92 mmHg in Group 1 and in Group 3, respectively (p = 0,193. The difference of intraocular pressure fluctuation was not statistically significant between Group 1 (mean 28,47±16,25% and Group3 (mean 33,27 ± 21,27% (p = 0,43. CONCLUSION: In our case series, no correlation was found between central corneal thickness and water drinkingtest results.

  12. Correlation between central corneal thickness and intraocular pressure peak and fluctuation during the water drinking test in glaucoma patients

    Scientific Electronic Library Online (English)

    Rafael Lacerda, Furlanetto; Antonio Carlos, Facio Jr; Marcelo, Hatanaka; Remo, Susanna Junior.

    Full Text Available OBJECTIVE: To investigate the correlation between central corneal thickness and outflow facility assessed by intraocular pressure peak and fluctuation during the water drinking test. METHODS: Fifty-five newly diagnosed primary open-angle glaucoma patients submitted to central corneal thickness measu [...] rements and water drinking test were enrolled in this retrospective study.;. Patients were divided into three groups according to their central corneal thickness. Pearson's Correlation test was performed in the groups with lower and higher pachymetric values. RESULTS: The mean age was 65,65 ± 28,28 years; 63,63% were female and 52,72% were caucasian. The mean central corneal thickness was 544,32 ± 36,86 µm, and the mean baseline intraocular pressure was 23,36 ± 6,26 mmHg. During the water drinking test, the mean intraocular pressure peak and mean intraocular pressure fluctuation were 30,43 ± 8,13 mmHg and 31,46 ± 18,46%, respectively. No relevant correlation was detected between the central corneal thickness and the intraocular pressure peak (r² = 0,021) or between the central corneal thickness and the intraocular pressure fluctuation (r² = 0,011). Group 1 presented a mean central corneal thickness of 505,81 ± 13,86 µm, and Group 3 was 583,55 ± 27,87 µm (p = 0,001). The mean intraocular pressure peak was 31,05 ± 9,05 mmHg and 27,83 ± 4,92 mmHg in Group 1 and in Group 3, respectively (p = 0,193). The difference of intraocular pressure fluctuation was not statistically significant between Group 1 (mean 28,47±16,25%) and Group3 (mean 33,27 ± 21,27%) (p = 0,43). CONCLUSION: In our case series, no correlation was found between central corneal thickness and water drinkingtest results.

  13. Seasonal fluctuations in the occurrence of Cladocera in the Mandovi-Zuari estuarine waters of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C; Devassy, V.P.

    Annual fluctuations in environmental features were noticeable particularly in the concentration of salinity and nutrients. The cladocerans showed a wide range of salinity tolerance and exhibited positive correlation with chlorophyll a(r = 0...

  14. Regional and State Level Water Scarcity Report: Northeast United States

    Science.gov (United States)

    Nicoletti, C. K.; Lopez-Morales, C. A.; Hoover, J. H.; Voigt, B. G.; Vorosmarty, C. J.; Mohammed, I. N.

    2010-12-01

    There are an abundance of large-scale, coarse resolution global water scarcity studies, but the existing literature fails to address regional and state specific scarcity measures. Moreover, while environmental water requirements are an integral factor in the development and implementation of sustainable water management practices, only recently has this notion been introduced to water scarcity research. In this paper, we argue that developing a preliminary measure of water scarcity, at the regional and state levels, will allow for more informed policy development. The goal of this study is to generate a more comprehensive understanding of water scarcity in the Northeast, by gathering fine scale data, applying a consistent methodology to the calculation of a scarcity index, and analyzing the results to see relative trends in spatio-temporal water scarcity. Public supply, irrigation, rural, industrial and thermo-power withdrawals have been compiled from USGS state water use publications from 1950 to 1985. Using the WBMplus water model runoff data, state specific in-stream environmental water requirements were calculated using the accepted hydro-ecological methodology. Water scarcity was then calculated as a ratio of water withdrawals to total available water minus environmental flow requirements for the system. In so doing, this study generates a spatially explicit and temporally varying water scarcity indicator (WSI) for the Northeastern United States between 1950 and 2000 at the regional and state levels at a five-year time interval. Calculation of a spatial and temporal water scarcity indicator enabled us to identify regions and specific states that were: slightly exploited (WSI 1.0). The minimum environmental water requirements to maintain in-stream aquatic and riparian ecosystems for the Northeastern states ranged between 27.5 to 36.3 percent of the mean annual runoff within Vermont and Maryland, respectively. The regional WSI values ranged between 0.199 in 1950 and 0.512 in 1995, indicating increasing water scarcity over time as population and employment growth has placed greater demands on water resources. Additionally, our study revealed that in 1980, Massachusetts, Pennsylvania and New Jersey scarcity levels were 0.733, 0.790 and 0.857, respectively. Although the Northeastern United States is commonly perceived as a water rich region, moderate to heavily exploited levels of water stress were observed over the time period when a finer spatial scale is utilized. Water scarcity indicator values were disaggregated by state for each time period and illustrated using a series of maps. Additional descriptive statistics were used to elucidate the differences in water scarcity between states over time.

  15. Sizewell 'B' steam generator water level measurement

    International Nuclear Information System (INIS)

    First, as an introduction, the reasons why steam generator level measurement is important are explained. The relationship of the measurement to the Reactor Protection System (RPS) is discussed with an overview of the RPS. The measurement system and the need for wide and narrow range measurements is discussed. Differential pressure transmitters used on Sizewell-B to provide the measurement are surveyed and the installation of the transmitters and associated tubing connecting them to the process are considered. Problems encountered at Sizewell-B are described. (Author)

  16. Water level changes of high altitude lakes in Himalaya–Karakoram from ICESat altimetry

    Indian Academy of Sciences (India)

    Priyeshu Srivastava; Rakesh Bhambri; Prashant Kawishwar; D P Dobhal

    2013-12-01

    Himalaya–Karakoram (H–K) region hosts large number of high altitude lakes but are poorly gauged by in-situ water level monitoring method due to tough terrain conditions and poor accessibility. After the campaigns of ICESat during 2003–2009, now it is possible to achieve lake levels at decimetre accuracy. Therefore, in present study, high altitude lake levels were observed using ICESat/GLAS altimetry in H–K between 2003 and 2009 to generate baseline information. The study reveals that out of 13 lakes, 10 lakes show increasing trend of water levels at different rate (mean rate 0.173 m/y) whereas three lakes unveiled decreasing trend (mean rate ?0.056 m/y). Out of five freshwater lakes, four lakes show an increasing trend of their level (mean rate 0.084 m/y) whereas comparatively six salt lakes (out of seven salt lakes) exhibited ?3 times higher mean rate of lake level increase (0.233 m/y). These observed lake level rise can be attributed to the increased melt runoffs (i.e., seasonal snow and glacier melts) owing to the enhanced mean annual and seasonal air temperature during past decade in north-western (NW) Himalaya. Further, varied behaviours of lake level rises in inter- and intra-basins suggest that the local climatic fluctuations play prominent role along with regional and global climate in complex geographical system of NW Himalaya.

  17. Secondary mineral evidence of large-scale water table fluctuations at Yucca Mountain, Nye County, Nevada

    International Nuclear Information System (INIS)

    At Yucca Mountain, currently under consideration as a potential permanent underground repository for high-level radioactive wastes, the present-day water table is 500 to 700 m deep. This thick unsaturated zone (UZ) is part of the natural barrier system and is regarded as a positive attribute of the potential site. The USGS has studied the stable isotopes and petrography of secondary calcite and silica minerals that coat open spaces in the UZ and form irregular veins and masses in the saturated zone (SZ). This paper reviews the findings from the several studies undertaken at Yucca Mountain on its mineralogy

  18. Secondary mineral evidence of large-scale water table fluctuations at Yucca Mountain, Nye County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Whelan, J.F.; Moscati, R.J.; Marshall, B.D [Geological Survey, Denver, CO (United States). Yucca Mountain Project Branch; Roedder, E. [Harvard Univ., Cambridge, MA (United States)

    1997-12-01

    At Yucca Mountain, currently under consideration as a potential permanent underground repository for high-level radioactive wastes, the present-day water table is 500 to 700 m deep. This thick unsaturated zone (UZ) is part of the natural barrier system and is regarded as a positive attribute of the potential site. The USGS has studied the stable isotopes and petrography of secondary calcite and silica minerals that coat open spaces in the UZ and form irregular veins and masses in the saturated zone (SZ). This paper reviews the findings from the several studies undertaken at Yucca Mountain on its mineralogy.

  19. Relict faunal testimony for sea-level fluctuations off Myanmar (Burma)

    Digital Repository Service at National Institute of Oceanography (India)

    Panchang, R.; Nigam, R.; Raviprasad, G.V.; Rajagopalan, G.; Ray, D.K.; Hla, U Ko Yi

    in the geological past. Radiocarbon AMS dating of 7 select samples representing different depths revealed different ages at different depths. To derive a sea-level curve, the sea level was assigned to 17.5 m above the depth of finding the relict fauna as deciphered...

  20. Carboxyhaemoglobin levels in water-pipe and cigarette smokers

    Scientific Electronic Library Online (English)

    Ansa, Theron; Cedric, Schultz; James A, Ker; Nadia, Falzone.

    2010-02-01

    Full Text Available Water-pipe smoking is growing in popularity, especially among young people, because of the social nature of the smoking session and the assumption that the effects are less harmful than those of cigarette smoking. It has however been shown that a single water-pipe smoking session produces a 24-hour [...] urinary cotinine level equivalent to smoking 10 cigarettes per day. AIM: We aimed to measure carboxyhaemoglobin (COHb) blood levels before and after water-pipe and cigarette smoking sessions. METHOD: Self-confessed smokers older than 18 years (N=30) volunteered to smoke a water-pipe or a cigarette and have their blood COHb levels measured under controlled conditions. RESULTS: Mean baseline COHb levels were 2.9% for the 15 cigarette smokers and 1.0% for the 15 water-pipe smokers. Levels increased by a mean of 481.7% in water-pipe smokers as opposed to 39.9% in cigarette smokers. CONCLUSION: The study demonstrated that water-pipe smokers had significantly higher increases in blood COHb levels thancigarette smokers during a single smoking session.

  1. Modelling Water Level Influence on Habitat Choice and Food Availability for Zostera Feeding Brent Geese Branta bernicla in Non-Tidal Areas

    DEFF Research Database (Denmark)

    Clausen, P.

    2000-01-01

    Brent geese Branta bernicla spring fattening around Agero, Denmark, alternate between feeding on saltmarshes and submerged Zostera beds in Limfjorden. It appeared from field observations that these alternations depended on the water level in Limfjorden. A model was developed to assess the impact of water level fluctuations on the habitat use. A second model was developed to estimate the impact of water level on Zostera availability. The first model was successful in demonstrating that fluctuations in water levels had considerable influence on habitat use by the brent geese, i.e. they fed on Zostera at low water levels and on saltmarshes during high water levels, particularly so in early spring, and that the switch between habitats occurred within a narrow water level span of ca 30 cm. The second model demonstrated that the switch between habitats could be explained by lowered availability of Zostera as water levels increased. By combining the output from the two models, differences between years could partly be explained by differences in Zostera availability in the early spring period (21 March - 25 April), whereas a more complicated situation was detected later in spring (26 April - 31 May). The models presented may be considered as tools in investigations of habitat use and carrying capacity of seagrass beds in non-tidal areas, where birds' access to feeding areas regularly may be hindered by high water levels.

  2. A multi-source satellite data approach for modelling Lake Turkana water level: Calibration and validation using satellite altimetry data

    Science.gov (United States)

    Velpuri, N.M.; Senay, G.B.; Asante, K.O.

    2012-01-01

    Lake Turkana is one of the largest desert lakes in the world and is characterized by high degrees of interand intra-annual fluctuations. The hydrology and water balance of this lake have not been well understood due to its remote location and unavailability of reliable ground truth datasets. Managing surface water resources is a great challenge in areas where in-situ data are either limited or unavailable. In this study, multi-source satellite-driven data such as satellite-based rainfall estimates, modelled runoff, evapotranspiration, and a digital elevation dataset were used to model Lake Turkana water levels from 1998 to 2009. Due to the unavailability of reliable lake level data, an approach is presented to calibrate and validate the water balance model of Lake Turkana using a composite lake level product of TOPEX/Poseidon, Jason-1, and ENVISAT satellite altimetry data. Model validation results showed that the satellitedriven water balance model can satisfactorily capture the patterns and seasonal variations of the Lake Turkana water level fluctuations with a Pearson's correlation coefficient of 0.90 and a Nash-Sutcliffe Coefficient of Efficiency (NSCE) of 0.80 during the validation period (2004-2009). Model error estimates were within 10% of the natural variability of the lake. Our analysis indicated that fluctuations in Lake Turkana water levels are mainly driven by lake inflows and over-the-lake evaporation. Over-the-lake rainfall contributes only up to 30% of lake evaporative demand. During the modelling time period, Lake Turkana showed seasonal variations of 1-2m. The lake level fluctuated in the range up to 4m between the years 1998-2009. This study demonstrated the usefulness of satellite altimetry data to calibrate and validate the satellite-driven hydrological model for Lake Turkana without using any in-situ data. Furthermore, for Lake Turkana, we identified and outlined opportunities and challenges of using a calibrated satellite-driven water balance model for (i) quantitative assessment of the impact of basin developmental activities on lake levels and for (ii) forecasting lake level changes and their impact on fisheries. From this study, we suggest that globally available satellite altimetry data provide a unique opportunity for calibration and validation of hydrologic models in ungauged basins. ?? Author(s) 2012.

  3. Levels of toxaphene congeners in fish from Danish waters

    DEFF Research Database (Denmark)

    Fromberg, Arvid; Cederberg, Tommy Licht; Hilbert, G.; Büchert, Arne

    2000-01-01

    The levels of toxaphene congeners, in addition to PCB congeners and organochlorine pesticides, were determined in various fish samples from different Danish waters. While PCB-153 and p,p'-DDE show different levels depending on the fishing area, with highest levels in fish from the Western Baltic Sea, toxaphene was detected in all the samples investigated at a more constant level. The distribution of the three toxaphene congeners Parlar #26, #50 and #62 depends on the fishing area, with the Weste...

  4. Recent water level declines in the Lake Michigan-Huron system.

    Science.gov (United States)

    Sellinger, Cynthia E; Stow, Craig A; Lamon, E Conrad; Qian, Song S

    2008-01-15

    Great Lakes water levels have fluctuated over thousands of years. High water levels were a problem in the 1980s, but a recent sudden drop in Lakes Michigan and Huron has caused particular concern, in part because lower water levels are consistent with many global climate change scenarios. We examined water level data (1860-2006) representing Lakes Michigan and Huron to evaluate changes in both long-term and seasonal patterns over time, and explore relationships with candidate predictor variables. Our tools for this analysis included both Seasonal Trend decomposition using Loess (STL), and dynamic linear models (DLM). In addition to the recent decline, STL results reveal a sustained decline around 1900, a long-term periodicity of approximately 30 years, and an unexpected correspondence with sunspot activity. DLM results indicate a relationship with precipitation over a three-year lagged period, which has been essentially unchanging from 1900 to present. Additionally, the DLM highlights an underlying lake level decline beginning in approximately 1973 and continuing to the present, which may have been obscured by concurrently increasing precipitation into the 1990s. The current underlying decline might be related to a simultaneous evaporation increase, however, our model could not confirm this relationship, possibly due to the shorter period of record for evaporation data. We cannot be certain that the present observed water level drop is caused by factors related to global climate change, orthat it portends a long-term problem. However, because the underlying decline has been ongoing for approximately 33 years it may be prudent to include lower lake levels in future management planning. PMID:18284132

  5. Water level and vegetation change analysis at Stillwater Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aim of the project summarized in this report was to determine the feasibility of detecting change in surface water levels and associated wetland biomass at the...

  6. Water-level change, High Plains aquifer, 1980 to 1995

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 1980 to 1995, in feet. The High Plains aquifer underlies...

  7. Water-level change, High Plains aquifer, 2005 to 2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 2005 to 2009, in feet. The High Plains aquifer underlies...

  8. Water-level change, High Plains aquifer, 1995 to 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 1995 to 2000, in feet. The High Plains aquifer underlies...

  9. Water-level change, High Plains aquifer, 2000 to 2005

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 2000 to 2005, in feet. The High Plains aquifer underlies...

  10. NOS CO-OPS Water Level Data, Verified, Hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has verified (quality-controlled), hourly, water level (tide) data from NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS)....

  11. NOS CO-OPS Water Level Data, Verified, 6-Minute

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has verified (quality-controlled), 6-minute, water level (tide) data from NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS)....

  12. Water level reconstruction of steam generator based on GMDH

    International Nuclear Information System (INIS)

    Falsehood or forfeiture occurs frequently on the water level indicating meters of the steam generator, and there is no appropriate way that can precisely identify the water level but through the experience of the operator on that condition, which grievously affects the judgment of the operator on operation state of the nuclear power plant. GMDH is a flexible and normally used method to establish complicated non-linear large system mathematics model, which makes good effects when dealing with non-linear objects. A method reconstructing the water level of steam generator with GMDH in the circumstance that the crevasse of primary stream pipeline appeared was described. In comparison with the emulation results, it shows that GMDH can reconstruct the water level of steam generator accurately. The outcome can meet the practical needs and give guidance on the safe operation of the marine nuclear power plant. (authors)

  13. NOS CO-OPS Water Level Data, Verified, High Low

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has verified (quality-controlled), daily, high low water level (tide) data from NOAA NOS Center for Operational Oceanographic Products and Services...

  14. NOS CO-OPS Water Level Data, Preliminary, 6-Minute

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has recent, preliminary (not quality-controlled), 6-minute, water level (tide) data from NOAA NOS Center for Operational Oceanographic Products and...

  15. NOS CO-OPS Water Level Data, Preliminary, 1-Minute

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has recent, preliminary (not quality-controlled), 1-minute, water level (tide) data from NOAA NOS Center for Operational Oceanographic Products and...

  16. 2012 Water Levels - Mojave River and the Morongo Groundwater Basins

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — During 2012, the U.S. Geological Survey and other agencies made approximately 2,500 water-level measurements in the Mojave River and Morongo groundwater basins....

  17. Potential effects of climate change on the water level, flora and macro-fauna of a large neotropical wetland.

    Science.gov (United States)

    Úbeda, Bárbara; Di Giacomo, Adrian S; Neiff, Juan José; Loiselle, Steven A; Poi, Alicia S Guadalupe; Gálvez, José Ángel; Casco, Silvina; Cózar, Andrés

    2013-01-01

    Possible consequences of climate change in one of the world's largest wetlands (Ibera, Argentina) were analysed using a multi-scale approach. Climate projections coupled to hydrological models were used to analyse variability in wetland water level throughout the current century. Two potential scenarios of greenhouse gas emissions were explored, both resulting in an increase in the inter-annual fluctuations of the water level. In the scenario with higher emissions, projections also showed a long-term negative trend in water-level. To explore the possible response of biota to such water-level changes, species-area relationships of flora and aerial censuses of macro-fauna were analysed during an extraordinary dry period. Plant species richness at the basin scale was found to be highly resistant to hydrological changes, as the large dimension of the wetland acts to buffer against the water-level variations. However, local diversity decreased significantly with low water levels, leading to the loss of ecosystem resilience to additional stressors. The analysis of macro-fauna populations suggested that wetland provides refuge, in low water periods, for the animals with high dispersal ability (aquatic and migratory birds). On the contrary, the abundance of animals with low dispersal ability (mainly herbivorous species) was negatively impacted in low water periods, probably because they are required to search for alternative resources beyond the wetland borders. This period of resource scarcity was also related to increased mortality of large mammals (e.g. marsh deer) around water bodies with high anthropogenic enrichment and cyanobacteria dominance. The synergy between recurrent climatic fluctuations and additional stressors (i.e. biological invasions, eutrophication) presents an important challenge to the conservation of neotropical wetlands in the coming decades. PMID:23874446

  18. Water levels through 1989 in bedrock aquifers in South Dakota

    Science.gov (United States)

    Winter, Douglas R.

    1994-01-01

    The U.S. Geological Survey, in cooperation with the South Dakota Department of Environmental and Natural Resources, has collected water-level data for 237 wells completed in bedrock aquifers throughout South Dakota. The water levels are presented in hydrographs in the main body of the report and in tables in a Supplemental Information section at the end of the report. The data are organized by county, in alphabetical order.

  19. Stationary flow solution for water levels in open channels

    OpenAIRE

    Opheusden, J.H.J. van; Molenaar, J (Jaap); Beltman, W.H.J.; Adriaanse, P.I.

    2010-01-01

    We study stationary flow in open discharge channels. A model is derived from basic principles, which is solved numerically for the water level and discharge as a function of position along the channel. The model describes the effect of external inflow from fields adjacent to the channel. Several scenarios are calculated, both for very slowly, and more rapidly flowing water courses.

  20. Typhoon and elevated radon level in a municipal water supply

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Cheng-Hsin [Nuclear Science and Development Center, National Tsing Hua Univ., Taiwan (China); Weng, Pao-Shan [Radiation Protection Association ROC, Taiwan (China)

    2000-05-01

    The Municipal Water Supply at Hsinchu City is a water treatment plant using poly- aluminum chloride (PAC) for coagulation and then followed by precipitation and filtration. Its capacity is 70,000 m{sup 3}/day. The raw water is drawn from the nearby river. Since the subject of interest is the radon level during typhoon season, the sampling period was from March to December 1999. Commercially available electret was used for water samples taken from the five ponds in the plant. This technique relies on the measurement of radon in air above a water sample enclosed in a sealed vessel. The concentration of airbone radon released from water was determined by means of the electret ion chamber. During the first sampling period there came two typhoons. One is called Magie during June 10-17, and the other called Sam during August 20-26. The first typhoon led to the radon level measured from the water samples as high as 705 Bq/m{sup 3}, while the second caused even higher radon level as high as 772 Bq/m{sup 3}. Similar results were obtained for the second sampling period after August till December 1999. For those measured without typhoon influence, the average radon was lower from the coagulation pond yet without coagulation process during March through August 1999. However, water samples taken from the pond after precipitation did not show similar results in radon level. (author)

  1. Typhoon and elevated radon level in a municipal water supply

    International Nuclear Information System (INIS)

    The Municipal Water Supply at Hsinchu City is a water treatment plant using poly- aluminum chloride (PAC) for coagulation and then followed by precipitation and filtration. Its capacity is 70,000 m3/day. The raw water is drawn from the nearby river. Since the subject of interest is the radon level during typhoon season, the sampling period was from March to December 1999. Commercially available electret was used for water samples taken from the five ponds in the plant. This technique relies on the measurement of radon in air above a water sample enclosed in a sealed vessel. The concentration of airbone radon released from water was determined by means of the electret ion chamber. During the first sampling period there came two typhoons. One is called Magie during June 10-17, and the other called Sam during August 20-26. The first typhoon led to the radon level measured from the water samples as high as 705 Bq/m3, while the second caused even higher radon level as high as 772 Bq/m3. Similar results were obtained for the second sampling period after August till December 1999. For those measured without typhoon influence, the average radon was lower from the coagulation pond yet without coagulation process during March through August 1999. However, water samples taken from the pond after precipitation did not show similar results in radon level. (author)

  2. Quantitative assessment of glacial fluctuations in the level of Lake Lisan, Dead Sea rift

    Science.gov (United States)

    Rohling, Eelco J.

    2013-06-01

    A quantitative understanding of climatic variations in the Levant during the last glacial cycle is needed to support archaeologists in assessing the drivers behind hominin migrations and cultural developments in this key region at the intersection between Africa and Europe. It will also foster a better understanding of the region's natural variability as context to projections of modern climate change. Detailed documentation of variations in the level of Lake Lisan - the lake that occupied the Dead Sea rift during the last glacial cycle - provides crucial climatic information for this region. Existing reconstructions suggest that Lake Lisan highstands during cold intervals of the last glacial cycle represent relatively humid conditions in the region, but these interpretations have remained predominantly qualitative. Here, I evaluate realistic ranges of the key climatological parameters that controlled lake level, based on the observed timing and amplitudes of lake-level variability. I infer that a mean precipitation rate over the wider catchment area of about 500 mm y-1, as proposed in the literature, would be consistent with observed lake levels if there was a concomitant 15-50% increase in wind speed during cold glacial stadials. This lends quantitative support to previous inferences of a notable increase in the intensity of Mediterranean (winter) storms during glacial periods, which tracked eastward into the Levant. In contrast to highstands during ‘regular’ stadials, lake level dropped during Heinrich Events. I demonstrate that this likely indicates a further intensification of the winds during those times.

  3. Solar Driven Automatic Water Level Controller with Dry Run Protection

    Directory of Open Access Journals (Sweden)

    V. Ravikiran,

    2015-11-01

    Full Text Available This paper presents solar driven automatic water level controller with dry run protection (SDWLC. The main purpose of SDWLC is to reduce wastage of water, to stop dry running of motor and to use solar energy effectively by using PV system. Generally water is pumped to overheadtank (OHT from undergroundtank (UGT.People will switch on pump when taps go dry, switch off pump when water over flows and they does not check dry running of motor during this. Also pumping of water to OHT during power cuts is a major problem in most of villages and in some of cities. However these problems can be solved by SDWLC. By using inverter the DC generated from PV system is converted in to AC and given to the motor. The operation of water level controller works upon the fact that water conducts electricity. So water can be used to open or close a circuit. As the water level rises or falls, different circuits in the controller send different signals. These signals are used to switch ON or switch OFF the motor pump as per our requirements.

  4. Transient response of Salix cuttings to changing water level regimes

    Science.gov (United States)

    Gorla, L.; Signarbieux, C.; Turberg, P.; Buttler, A.; Perona, P.

    2015-03-01

    Sustainable water management requires an understanding of the effects of flow regulation on riparian ecomorphological processes. We investigated the transient response of Salix viminalis by examining the effect of water-level regimes on its above-ground and below-ground biomass. Four sets of Salix cuttings, three juveniles (in the first growing season) and one mature (1 year old), were planted and initially grown under the same water-level regime for 1 month. We imposed three different water-level regime treatments representing natural variability, a seasonal trend with no peaks, and minimal flow (characteristic of hydropower) consisting of a constant water level and natural flood peaks. We measured sap flux, stem water potential, photosynthesis, growth parameters, and final root architecture. The mature cuttings were not affected by water table dynamics, but the juveniles displayed causal relationships between the changing water regime, plant growth, and root distribution during a 2 month transient period. For example, a 50% drop in mean sap flux corresponded with a -1.5 Mpa decrease in leaf water potential during the first day after the water regime was changed. In agreement with published field observations, the cuttings concentrated their roots close to the mean water table of the corresponding treatment, allowing survival under altered conditions and resilience to successive stress events. Juvenile development was strongly impacted by the minimum flow regime, leading to more than 60% reduction of both above-ground and below-ground biomass, with respect to the other treatments. Hence, we suggest avoiding minimum flow regimes where Salix restoration is prioritized.

  5. Relationships Between Skin Properties and Body Water Level

    OpenAIRE

    Andersson, Ida; Hedvall, Anders

    2013-01-01

    A need for a quantitative method to determine body water level has been identified by a team of Clinical Innovation Fellows at the Centre for Technology in Medicine and Health (CTMH). A reliable way to determine body water level would bring great benefits to the healthcare sector, where no optimal method is available at the time of writing. A possible solution is a sensor that would measure alterations in skin properties due to changes in total body water. CTMH has had an idea of such a senso...

  6. Current-induced two-level fluctuations in pseudo spin-valves (Co/Cu/Co) nanostructures

    CERN Document Server

    Fabian, A C; Guisan, S S; Hoffer, X; Dubey, M; Gravier, L; Ansermet, J P; Wegrowe, J E

    2003-01-01

    Two-level fluctuations of the magnetization state of pseudo spin-valve pillars Co(10 nm)/Cu(10 nm)/Co(30 nm) embedded in electrodeposited nanowires (~40 nm in diameter, 6000 nm in length) are triggered by spin-polarized currents of 10^7 A/cm^2 at room temperature. The statistical properties of the relaxation times between transitions from parallel to antiparallel magnetization states (and vice versa) reveal two effects with qualitatively different dependences on current intensity. The current appears to have the effect of a bias field, evaluated experimentally as the counteracting applied field that equalizes the mean relaxation times. When the energy profile is a symmetric double well, the effect of a current density of 10^7 A/cm^2 is to decrease the effective energy barrier by 1000 K. The bias field changes sign when the current polarity is reversed. The barrier is lowered, irrespective of the sign of the current.

  7. Sea-level fluctuations and coastal evolution in the state of Rio de Janeiro, southeastern Brazil

    Scientific Electronic Library Online (English)

    JOÃO WAGNER A., CASTRO; KENITIRO, SUGUIO; JOSÉ C.S., SEOANE; ALINE M. DA, CUNHA; FABIO F., DIAS.

    2014-06-01

    Full Text Available O presente trabalho tem como objetivo investigar as variações do nível relativo do mar e a evolução costeira durante o Holoceno no litoral do Estado do Rio de Janeiro, com base em indicadores geológicos e biológicos. Realizou-se levantamento altimétrico, execução de sondagens e datações ao 14C na pl [...] anície costeira e em afloramentos de rochas de praia. A partir dos dados obtidos, construiu-se uma curva do nível relativo do mar para o Holoceno. Pela primeira vez na costa brasileira foi identificado um recorde negativo do nível relativo do mar, envolvendo a transição final do Pleistoceno e início do Holoceno. Após a transição, iniciou-se um processo relativamente rápido de subida do nível do mar. Há aproximadamente 8.500 anos cal A.P., o nível marinho, encontrava-se a - 0.5 m abaixo do nível atual. O “zero” (nível médio atual) foi ultrapassado pela primeira vez no Holoceno há cerca de 7.500 anos A.P. Entre 5.500 - 4.500 cal anos A.P, o nível relativo do mar atingiu o primeiro máximo holocênico com altura máxima de +2.50 m acima do atual. A descida do nível relativo do mar subseqüente ao máximo transgressivo, levou à construção de terraços marinhos, resultando na progradação da linha de costa até o presente. A maioria dos resultados corroboram dados já obtidos em outros segmentos da costa atlântica da América do Sul. Resultados aqui apresentados são consistentes com pesquisas anteriores e ajudam refinar o registro do nível relativo do mar Holoceno na costa brasileira. Abstract in english The present paper aims to investigate the relative sea-level and the coastal evolution during the Holocene in the Rio de Janeiro coastline, based on geological and biological indicators. Using topographic survey, excavation and coring, and 14C dating of these coastal deposits and beachrocks outcrops [...] , we have reconstructed a sea-level curve for the Holocene. For the first time on the Brazilian coast it was identified a negative record of relative sea-level during Late Pleistocene and Early Holocene transition. After the transition, a relatively rapid increase of sea-level began. At approximately at 8500 cal yr BP, the sea-level was 0.5 m below the current level, was overtaken for the first time in the Holocene, at approximately 7500 cal yr BP. The maximum level of +2.5 m was reached between 4770 and 4490 cal yr BP. At the point of maximum transgression, the sea-level began a general behavior of lowering until the present. These results confirm other data already obtained elsewhere along the Atlantic coast of South America. The results of this study are consistent with previous researches and they help to refine the Holocene sea-level record along the Brazilian coast.

  8. ELEVATED LEVELS OF SODIUM IN COMMUNITY DRINKING WATER

    Science.gov (United States)

    A comparison study of students from towns with differing levels of sodium in drinking water revealed statistically significantly higher blood pressure distributions among the students from the town with high sodium levels. Differences were found in both systolic and diastolic rea...

  9. Performance of broilers submitted to high CO2 levels during incubation combined with temperature fluctuations at late post-hatch

    Scientific Electronic Library Online (English)

    JIM, Fernandes; C, Bortoluzzi; AFG, Esser; JP, Contini; PB, Stokler; D, Faust.

    2014-09-01

    Full Text Available Incubation represents around 1/3 of the life cycle of broilers of modern strains; therefore, the appropriate management of this period is crucial to ensure the quality of the neonate. An experiment evaluated the effect of carbon dioxide concentrations during incubation on the live performance, heart [...] morphology, and differential leukocyte count in the blood of broilers submitted to fluctuating temperatures between 35 and 42 days of age. In total, 2,520 fertile eggs were distributed according to a completely randomized design with four CO2 concentrations (4,000; 6,000; 8,000 and 10,000 ppm) during the first ten days of incubation, after which all eggs were incubated at the same CO2 level (4,000 ppm). After hatching, male chicks were placed in the experimental broiler houses, and at 35 days of age, 25 birds from each level of CO2 were separated and placed in cages to study the effect of cyclic temperature variations up to 42 days of age on their live performance, heterophil:lymphocyte ratio, and heart morphology. At 42 days of age, blood was collected for hematology and two birds per replicate were sacrificed and evaluated for ascites score and heart and liver relative weights. Heart morphology was assessed by analyzing digital images. In this experiment, hypercapnia during incubation and fluctuating temperatures during the growout did not affect mortality, ascites score, heart and liver relative weights, or heart characteristics (p>0.05). However, heterophill:lymphocyte ratio increased (p

  10. Reticulate evolution and sea-level fluctuations together drove species diversification of slipper orchids (Paphiopedilum) in South-East Asia.

    Science.gov (United States)

    Guo, Yan-Yan; Luo, Yi-Bo; Liu, Zhong-Jian; Wang, Xiao-Quan

    2015-06-01

    South-East Asia covers four of the world's biodiversity hotspots, showing high species diversity and endemism. Owing to the successive expansion and contraction of distribution and the fragmentation by geographical barriers, the tropical flora greatly diversified in this region during the Tertiary, but the evolutionary tempo and mode of species diversity remain poorly investigated. Paphiopedilum, the largest genus of slipper orchids comprising nearly 100 species, is mainly distributed in South-East Asia, providing an ideal system for exploring how plant species diversity was shaped in this region. Here, we investigated the evolutionary history of this genus with eight cpDNA regions and four low-copy nuclear genes. Discordance between gene trees and network analysis indicates that reticulate evolution occurred in the genus. Ancestral area reconstruction suggests that vicariance and long-distance dispersal together led to its current distribution. Diversification rate variation was detected and strongly correlated with the species diversity in subg. Paphiopedilum (~80 species). The shift of speciation rate in subg. Paphiopedilum was coincident with sea-level fluctuations in the late Cenozoic, which could have provided ecological opportunities for speciation and created bridges or barriers for gene flow. Moreover, some other factors (e.g. sympatric distribution, incomplete reproductive barriers and clonal propagation) might also be advantageous for the formation and reproduction of hybrid species. In conclusion, our study suggests that the interplay of reticulate evolution and sea-level fluctuations has promoted the diversification of the genus Paphiopedilum and sheds light into the evolution of Orchidaceae and the historical processes of plant species diversification in South-East Asia. PMID:25847454

  11. Water levels in bedrock aquifers in South Dakota

    Science.gov (United States)

    Bradford, Wendell L.

    1981-01-01

    This report on water levels in bedrock aquifers in South Dakota is the result of a continuing investigation begun in 1959 by the U.S. Geological Survey in cooperation with the South Dakota Department of Water and Natural Resources. The purpose of the investigation is to collect data on the artesian water supply in the bedrock aquifers and to present these data in data reports that will aid in planning the use and conservation of water from these aquifers in South Dakota. The locations of wells were data have been collected are included. (USGS)

  12. Holocene Sea-Level Fluctuations and Paleo-environmental changes in Maputo Bay, Mozambique, using stable isotopes

    Science.gov (United States)

    Martinez de Lecea, Ander; Green, Andrew; Wiles, Errol; Strachan, Kate; Cooper, Andrew

    2015-04-01

    Mozambique has been classified as a "hot-spot" for potential impacts derived from sea-level rise, yet there is little knowledge on past sea-level fluctuation in this part of the world. Further understanding of sea-level fluctuations in the region would be of great benefit. To this end a high resolution record of paleo-environmental changes in Maputo Bay, Mozambique, are determined. Stable isotope analyses (?13Corg; ?15N; ?18O) are conducted on the sediment organic matter and foraminifera Elphidium crispum from two cores, a 3.6 m long core collected at 5m below mean sea-level (m.s.l.) (Core V13) and a 6.2 m long core collected at 13.5m below m.s.l. (Core V40). Evolution of the region is informed through a seismic study and dating of cores is under-way using 14C analysis. The two cores analysed in this study showed evidence of catastrophic flooding events, as well as environmental changes. Core V13 represents a higher resolution of environmental changes, while core V40 shows a longer period, with the system changing from terrestrial dominated environment to marine, to terrestrially dominated once again before settling at the present system of marine dominated environment. The deepest layer of Core V13 is of marine origin with evidence of beachrock formation occurring, indicating a beach environment, while the top 190 cm indicate repeated alternation between marine and terrestrial environments, representing a contemporary highstand bay-head delta highly influenced by terrestrial input. This is further supported by the seismic interpretation. Enriched ?15N signatures from the terrestrial layers from the top 190 cm, could suggest the settling of early Europeans in the area (~1,544 AD). Core V40's deepest layer is of terrestrial origin, and terminates abruptly in marine sand, most likely due to the sudden, catastrophic collapse of the dune barrier following sea-level rise. Comparisons of preliminary results with existing studies suggests that this core covers a time period of almost 10 ka yr BP and we anticipate that the 14C results will confirm this. Finally, there is evidence of vegetation change in Maputo Bay through time; core V40's terrestrial strata have a strong C3 plant (original forest) signature, while the terrestrial strata from core V13 have a C4 plant (current crops) signature. Our results suggest that Maputo Bay represents an extremely dynamic environment for at least the last 9 ka yr BP, where sudden, catastrophic events can occur, and provide important insights into the environmental evolution of the region.

  13. WATER-LEVEL MONITOR FOR BOREWELL AND WATER TANK BASED ON GSM

    Directory of Open Access Journals (Sweden)

    R.Ramani

    2012-10-01

    Full Text Available Now a days, home automation & remote control and monitoring systems have seen a rapid growth in terms of technology. Apparently there is no early warning system to monitor the tank water level and bore well water level when it has reached the critical level. In this paper we have provided water level monitoring in the tank as well as in the bore well. If the water level in a bore well drops below the threshold level for pumping its pump motor may get air locked or more burn out due to dry running. It is awkward for farmers to walk all the way to their fields at night just to switch the pump motor off. Besides, he may never get to identify the problem. This problem can be solved by using this GSM based system that will automatically make a call to the user mobile phone, when the water Level in the bore well drops threshold below or rises to the threshold level for pumping. The user can also remotely switch on or off the pump motor by sending a SMS from his mobile phone. The system is simple, reliable, portable and affordable. We proposed the work in which, Whenever water level in the tankdrops below the required level the system try to fill the tank by switching on the bore well motor to pump the water into the tank It is must to have enough water in the bore well to avoid the formation of air gap or empty running of bore well motor. High precision water level sensor is used to identify the reference water level to activate and deactivate the motor and system properly by interfacing the sensor devices into the well definedembedded system.

  14. Uranium Redistribution Due to Water Table Fluctuations in Sandy Wetland Mesocosms.

    Science.gov (United States)

    Gilson, Emily R; Huang, Shan; Koster van Groos, Paul G; Scheckel, Kirk G; Qafoku, Odeta; Peacock, Aaron D; Kaplan, Daniel I; Jaffé, Peter R

    2015-10-20

    To understand better the fate and stability of immobilized uranium (U) in wetland sediments, and how intermittent dry periods affect U stability, we dosed saturated sandy wetland mesocosms planted with Scirpus acutus with low levels of uranyl acetate for 4 months before imposing a short drying and rewetting period. Concentrations of U in mesocosm effluent increased after drying and rewetting, but the cumulative amount of U released following the dry period constituted less than 1% of the total U immobilized in the soil during the 4 months prior. This low level of remobilization suggests, and XANES analyses confirm, that microbial reduction was not the primary means of U immobilization, as the U immobilized in mesocosms was primarily U(VI) rather than U(IV). Drying followed by rewetting caused a redistribution of U downward in the soil profile and to root surfaces. Although the U on roots before drying was primarily associated with minerals, the U that relocated to the roots during drying and rewetting was bound diffusely. Results show that short periods of drought conditions in a sandy wetland, which expose reduced sediments to air, may impact U distribution without causing large releases of soil-bound U to surface waters. PMID:26404564

  15. Monitoring water levels by integrating optical and synthetic aperture radar water masks with lidar DEMs

    Science.gov (United States)

    Hopkinson, C.; Brisco, B.; Patterson, S.

    2014-12-01

    The ability to map and monitor wetland and lake open water extent and levels across the landscape allows improved estimates of watershed water balance, surface storage and flood inundation. The study presents open water classifications over the wetland dominated Sheppard Slough watershed east of Calgary in western Canada using parallel temporal imagery captured from the RapidEye and RadarSat satellites throughout 2013, a year of widespread and costly flood inundation in this region. The optical and SAR-based temporal image stacks were integrated with a high-resolution lidar DEM in order to delineate regions of inundation on the DEM surface. GIS techniques were developed to extract lidar-derived water surface elevations and track the spatio-temporal variation in pond and lake water level across the watershed. Water bodies were assigned unique identifiers so that levels could be tracked and linked to their associated watershed channel reach. The procedure of optical image classification through to merging of individual water bodies into watershed channel topology and extracting reach water levels has been automated within python scripts. The presentation will describe: i) the procedures used; ii) a comparison of the SAR and optical classification and water level extraction results; iii) a discussion of the spatio-temporal variations in water level across the Sheppard Slough watershed; and iv) a commentary on how the approach could be implemented for web-based operational monitoring and as simulation initialisation inputs for flood inundation model studies.

  16. Dynamics of a Landau–Zener non-dissipative system with fluctuating energy levels

    International Nuclear Information System (INIS)

    This paper considers a Landau–Zener (two-level) system influenced by a three-dimensional Gaussian and non-Gaussian coloured noise and finds a general form of the time dependent diabatic quantum bit (qubit) flip transition probabilities in the fast, intermediate and slow noise limits. The qubit flip probability is observed to mimic (for low-frequencies noise) that of the standard LZ problem. The qubit flip probability is also observed to be the measure of quantum coherence of states. The transition probability is observed to be tailored by non-Gaussian low-frequency noise and otherwise by Gaussian low-frequency coloured noise. Intermediate and fast noise limits are observed to alter the memory of the system in time and found to improve and control quantum information processing

  17. An Indirect Adaptive Controller to Regulate UTSG Water Level in Pressurized Water Nuclear Reactor

    OpenAIRE

    Djamel Boukhetala; Touati Sai; Khaled Halbaoui; Feres Boudjema

    2012-01-01

    Stabilizing water level of the Steam Generator (SG) in nuclear power plant is a very important problem since its parameters vary with operating conditions and dynamics of the system is very different according to the power levels and changes as time goes on. Therefore, it is an intractable as well as challenging task to improve the water level control system of the SG. In this study, a new framework for building an adaptive Minimum Variance controller for stabilizing water-level of SG is prop...

  18. Fluctuations of Phytoplankton Community in the Coastal Waters of Caspian Sea in 2006

    OpenAIRE

    Siamak Bagheri; Mashhor Mansor; Marzieh Makaremi; Jalil Sabkara; W. O.W. Maznah; Alireza Mirzajani; Seyed H. Khodaparast; Hossein Negarestan; Azemat Ghandi; Akbar Khalilpour

    2011-01-01

    Problem statement: The Caspian Sea ecosystem has been suffered with many problems since 1980s. Aanthropogenic pollution from heavy metals, hydrocarbons, pesticides, changes in the quantity of nutrient inputs by rivers, are significant threats to biodiversity and biological resources such as plankton structure in the Caspian Sea. According to the significant of phytoplankton community in marine system. The state of the fluctuations of phytoplankton communities of the southwestern Caspian Sea w...

  19. Relation of drainage problems to high ground-water levels, Coconut Grove area, Oahu, Hawaii

    Science.gov (United States)

    Swain, L.A.; Huxel, C.J., Jr.

    1971-01-01

    Purpose and Scope In 1969, hydrologic data-collection sites were established in and around the Coconut Grove area for the purpose of measuring directly the relationship between rainfall, runoff, ground-water levels, the level of water in Kawainui Swamp and the canals, and tidal fluctuations. The primary objective was to identify the causes of the occurrence and persistence of flooding and to gain data on which to base recommendations for remedial action. The scope of the study included establishing and operating flow and stage-recording gages on the Swamp, Kawainui Canal, and the inner canal; periodic and repeated measurements of ground-water level in test borings throughout the residential area; collection and analysis of soil and construction borings made for engineering purposes; the assembly and analysis of all available data relating surface and subsurface flow conditions, and the development of conclusions as to the causes and means to alleviate the flooding. This report summarizes the information collected from October 1969 to June 1971, includes analysis of the data, and discusses the probable causes of flooding.

  20. Global Gray Water Footprint and Water Pollution Levels Related to Anthropogenic Nitrogen Loads to Fresh Water.

    Science.gov (United States)

    Mekonnen, Mesfin M; Hoekstra, Arjen Y

    2015-11-01

    This is the first global assessment of nitrogen-related water pollution in river basins with a specification of the pollution by economic sector, and by crop for the agricultural sector. At a spatial resolution of 5 by 5 arc minute, we estimate anthropogenic nitrogen (N) loads to freshwater, calculate the resultant gray water footprints (GWFs), and relate the GWFs per river basin to runoff to calculate the N-related water pollution level (WPL) per catchment. The accumulated global GWF related to anthropogenic N loads in the period 2002-2010 was 13 × 10(12) m(3)/y. China contributed about 45% to the global total. Three quarters of the GWF related to N loads came from diffuse sources (agriculture), 23% from domestic point sources and 2% from industrial point sources. Among the crops, production of cereals had the largest contribution to the N-related GWF (18%), followed by vegetables (15%) and oil crops (11%). The river basins with WPL > 1 (where the N load exceeds the basin's assimilation capacity), cover about 17% of the global land area, contribute about 9% of the global river discharge, and provide residence to 48% of the global population. PMID:26440220

  1. Poster abstract: Water level estimation in urban ultrasonic/passive infrared flash flood sensor networks using supervised learning

    KAUST Repository

    Mousa, Mustafa

    2014-04-01

    This article describes a machine learning approach to water level estimation in a dual ultrasonic/passive infrared urban flood sensor system. We first show that an ultrasonic rangefinder alone is unable to accurately measure the level of water on a road due to thermal effects. Using additional passive infrared sensors, we show that ground temperature and local sensor temperature measurements are sufficient to correct the rangefinder readings and improve the flood detection performance. Since floods occur very rarely, we use a supervised learning approach to estimate the correction to the ultrasonic rangefinder caused by temperature fluctuations. Preliminary data shows that water level can be estimated with an absolute error of less than 2 cm. © 2014 IEEE.

  2. Impacts of Water Levels on Breeding Canada Geese and the Methodology for Mitigation and Enhancement in the Flathead Drainage, 1983 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Ball, I. Joseph

    1984-01-01

    The lower Flathead River Canada goose study was initiated to determine goose population trends and the effects of water level fluctuations on Canada goose nest and brood habitat, as a result of releases from Kerr Dam. This report presents data collected during the 1983 field season (15 February to 30 September, 1983) as part of an ongoing project. (DT)

  3. Investigation of natural radioactivity levels in water around Kadugli, Sudan.

    Science.gov (United States)

    Osman, Alfatih A A; Salih, Isam; Shaddad, Ibrahim A; El Din, Saif; Siddeeg, M B; Eltayeb, Hatem; Idriss, Hajo; Hamza, Walid; Yousif, E H

    2008-11-01

    Surface water from Miri Lake and groundwater from around Kadugli (West-Central Sudan) obtained by means of hand-pumps was analysed for (238)U, (226)Ra, (222)Rn, and (232)Th activity concentrations. The surface water showed very low levels of radionuclide concentrations: natural radioactivity (16.1-1720, 7.7-14.3, 3000-139,000, level of 0.1 mSv yr(-1) except in one groundwater sample with an associated dose of 0.7 mSv yr(-1). PMID:18513978

  4. Wireless Automatic Water Level Control using Radio Frequency Communication

    OpenAIRE

    MUKTHA SHANKARI K; K.Jyothi; MANU E O; NAVEEN I P; HARSHA HERLE

    2013-01-01

    Water scarcity is the serious issue in major cities. It is a common problem which is faced by every house owner, that when his tank is empty he has to switch on the motor and switch the motor off when it is full. Due to the busy life it is common that the tank usually overflows without notice. One has to keep on observing his tank water level to switch off the motor once it is switched on. And sometimes this also can happen that the motor coil burns because of absence of water in the sump. So...

  5. Significance of steam separator models for BWR water level transients

    International Nuclear Information System (INIS)

    The loss-of-power accident (LOPA) test is required in the series of startup tests for a new plant. In this test, the reactor water level goes down further than in other tests, but it stays a sufficient margin above the lower limit level. However, there is a tendency for simulation results to give an overly conservative water level response compared with test data. Such a situation requires greater standby pump capacity in the feedwater system. After reviewing several possible model improvements, it was noted that the performance of the steam separator has a significant effect on the reactor water level calculation for this event. To develop an improved model, the inverse problem approach (IPA) was applied. The IPA consists of three main procedures: (a) state estimation from the sensed signal, (b) forced simulation to replace the method variable with the estimated state, and (c) introducing hypothetical parameters and tracing them so that the difference between calculated and measured reactor water levels is minimized during the simulation. The simulation results are summarized

  6. Measurement of water potential in low-level waste management

    International Nuclear Information System (INIS)

    The measurement of soil water is important to the shallow land burial of low-level waste. Soil water flow is the principle mechanism of radionuclide transport, allows the establishment of stabilizing vegetation and also governs the dissolution and release rates of the waste. This report focuses on the measurement of soil water potential and provides an evaluation of several field instruments that are available for use to monitor waste burial sites located in arid region soils. The theoretical concept of water potential is introduced and its relationship to water content and soil water flow is discussed. Next, four major areas of soils research are presented in terms of their dependence on the water potential concept. There are four basic types of sensors used to measure soil water potential. These are: (1) tensiometers; (2) soil psychrometers; (3) electrical resistance blocks; and (4) heat dissipation probes. Tensiometers are designed to measure the soil water potential directly by measuring the soil water pressure. Monitoring efforts at burial sites require measurements of soil water over long time periods. They also require measurements at key locations such as waste-soil interfaces and within any barrier system installed. Electrical resistance blocks are well suited for these types of measurements. The measurement of soil water potential can be a difficult task. There are several sensors commercially available; however, each has its own limitations. It is important to carefully select the appropriate sensor for the job. The accuracy, range, calibration, and stability of the sensor must be carefully considered. This study suggests that for waste management activities, the choice of sensor will be the tensiometer for precise soil characterization studies and the electrical resistance block for long term monitoring programs

  7. Fluctuations of the Caspian Sea level as an indicator of global climatic changes - using data from radiocarbon dating of sediments

    International Nuclear Information System (INIS)

    Because of the large area of the basin water, the level of the Caspian Sea reflects the global change of climate of the Northern hemisphere. In order to reconstruct the paleoclimatic situation, samples were taken from ancient salt marshes, depressions and bars which form when the sea level has fallen significantly. Mollusc shells, peat, carbonates and organic matter were used for 14C dating. The data obtained demonstrate the relationship between the sea level and climatic changes. During cooling the sea level rises and vice versa. This relates to the long-period (13,000 y) as well as to the short-period (2,000-2,500 y) and to secular changes of the climate. (author)

  8. Changes in copper water-effect ratios in toxicity tests conducted at varying water hardness levels

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, A.S.; Brady, M.D.; Stubblefield, W.A. [ENSR Consulting and Engineering, Fort Collins, CO (United States)

    1995-12-31

    Side-by-side acute toxicity tests (Oncorhynchus mykiss and Ceriodaphnia dubia) were conducted in SITE waters collected from a western Montana river and in laboratory waters reconstituted to match the hardness and alkalinity of the SITE water samples. Tests were conducted according to USEPA guidance on the determination and use of Water-Effect Ratios (WER). Multiple WERS, calculated as the ratio of LC50 values from SITE and LAB water tests, were regressed against water hardness and provided significant correlations (r{sup 2}=0.7 to 0.8 (logarithmic)). WERs increased with decreasing water hardness ranging from 1.1 at 282 mg/l hardness to 8.9 at 60 mg/l hardness. Additional tests showed that WER values for single water samples tested at multiple hardness levels (samples augmented with calcium and magnesium salts) again significantly correlated with water hardness. These results are independent of the known ameliorating effect of water hardness on metals toxicity, since WERs compared LC50s for tests conducted at identical water hardness levels. One explanation for this hardness-WER relationship may be that both hardness and certain other toxicity-reducing water quality parameters (e.g., suspended solids, organic carbon) compete in providing protection from the toxic effects of metals in surface waters. As hardness decreases, the importance of these other water quality parameters may increase, thus enhancing the difference between toxicity in soft laboratory reconstituted waters (lacking organic enrichment or suspended solids) and soft site-waters. These results have potentially important implications for the application of national Ambient Water Quality Criteria (Gold Book values) to soft surface waters moderately enriched in organic carbon, suspended solids, or other toxicity-mitigating factors.

  9. The response of mire vegetation to water level drawdown

    Science.gov (United States)

    Kurki, Kirsi; Laine, Jukka; Vasander, Harri; Tuittila, Eeva-Stiina

    2010-05-01

    Mires have a significant role in climate change mitigation due to their enormous carbon storage and due to the fluxes of greenhouse gases between ecosystem and the atmosphere. Mire vegetation is controlled by ecohydrology, climate and by the competition of plants on light and nutrients. The water logged conditions create a challenging environment for both vascular plants and bryophytes; therefore majority of plants growing in these habitats are highly specialized. Global warming is predicted to affect mire vegetation indirectly through increased evapotranspiration leading to decreased water table levels down to 14-22 centimeters. Water level drawdown is likely to affect the vegetation composition and consequently the ecosystem functioning of mires. Previous studies covering the first years following water table level drawdown have shown that vascular plants benefit from a lower water table and hollow-specific Sphagnum species suffer. In addition to changes in plant abundances the diversity of plant communities decreases. The lawn and hollow communities of Sphagna and sedges are found to be the most sensitive plant groups. It has been shown that surveys on vegetation changes can have different results depending on the time scale. The short and long term responses are likely vary in heterogenous mire vegetation; therefore predictions can be done more reliably with longer surveys. We applied BACI (before-after-control-impact) experimental approach to study the responses of different functional mire plant groups to water level drawdown. There are 3 control plots, 3 treatment plots with moderate water level drawdown and 3 plots drained for forestry 40 years ago as a reference. The plots are located in meso-, oligo- and ombrotrophic sites in Lakkasuo (Orivesi, Finland). The vegetation was surveyed from permanent sampling points before ditching in 2000 and during the years 2001-2003 and 2009. The data was analyzed with NMDS (PC-Ord) and DCA (CANOCO). Overall results show that the control and treatment plots were similar before the treatment which is crucial in studies conducted with BACI- experimental design. The vegetation composition in the varied between the years also in the control plots following variation in weather conditions, i.e., growing season temperature and precipitation. The year 2003 stood out with lowest water table levels and with highest coverage of the evergreen vascular plants in all plots. By 2009 there was a dramatic decrease in sedge species cover. There seems to be more changes in bryophyte cover in mesotrophic sites than in ombrotrophic ones. Especially lawn-specific Sphagnum responded to water level drawdown. To quantify the impact of water level drawdown for different plant groups we used Principal Response Curves (CANOCO). Results show that all plant groups have a different short and long term response to water level drawdown. The first three years after ditching appeared to be a disturbance state. Only after that the vegetation started to adapt to the lowered water table conditions.

  10. Inter-annual precipitation fluctuations alter the responses of above- and belowground biomass to water and N enrichment

    Directory of Open Access Journals (Sweden)

    D. L. Kong

    2013-08-01

    Full Text Available Water availability has profound effects on plant growth and productivity in temperate and semi-arid grasslands. However, it remains unclear how variation of inter-annual precipitation by extreme rainfall events will alter the aboveground and belowground responses of plants, and how these responses may be contingent on N availability. In this study, we examined the interactive effects of inter-annual precipitation variation and N addition on aboveground and live fine root biomass of a semi-arid grassland in northern China for two consecutive years (2007 and 2008. Inter-annual variation in precipitation resulting mainly from the occurrence of extreme rainfall events in 2008 significantly affected above- and belowground plant biomass responses to water addition. In addition, variation of inter-annual precipitation by this extreme rainfall event suppressed plant responses to nitrogen addition and reduced the interaction effects between water and nitrogen addition. These effects of inter-annual precipitation fluctuation could be attributed to the negative influence of the extreme rainfall event on soil N and water availability, ultimately reducing plant rainfall use efficiency and nitrogen use efficiency. In conclusion, our results suggest ecosystem responses to water and N enrichment could be altered by inter-annual variation of precipitation regime caused by the naturally occurring extreme rainfall events.

  11. Inter-annual precipitation fluctuations alter the responses of above- and belowground biomass to water and N enrichment

    Science.gov (United States)

    Kong, D. L.; Lü, X. T.; Jiang, L. L.; Wu, H. F.; Miao, Y.; Kardol, P.

    2013-08-01

    Water availability has profound effects on plant growth and productivity in temperate and semi-arid grasslands. However, it remains unclear how variation of inter-annual precipitation by extreme rainfall events will alter the aboveground and belowground responses of plants, and how these responses may be contingent on N availability. In this study, we examined the interactive effects of inter-annual precipitation variation and N addition on aboveground and live fine root biomass of a semi-arid grassland in northern China for two consecutive years (2007 and 2008). Inter-annual variation in precipitation resulting mainly from the occurrence of extreme rainfall events in 2008 significantly affected above- and belowground plant biomass responses to water addition. In addition, variation of inter-annual precipitation by this extreme rainfall event suppressed plant responses to nitrogen addition and reduced the interaction effects between water and nitrogen addition. These effects of inter-annual precipitation fluctuation could be attributed to the negative influence of the extreme rainfall event on soil N and water availability, ultimately reducing plant rainfall use efficiency and nitrogen use efficiency. In conclusion, our results suggest ecosystem responses to water and N enrichment could be altered by inter-annual variation of precipitation regime caused by the naturally occurring extreme rainfall events.

  12. The Importance of Water Temperature Fluctuations in Relation to the Hydrological Factor. Case Study – Bistrita River Basin (Romania

    Directory of Open Access Journals (Sweden)

    Cojoc Gianina Maria

    2014-10-01

    Full Text Available The increase in most components of the climate over the past 50 years, including air and water temperature, is a real phenomenon, as attested by the numerous specialized researches according to IPCC (2013. The water temperature is one of the most important climatic components in analyzing the hydrological regime of the Bistrita River (Romania. The thermal regime of the Bistrita River basin and the frost phenomena associated with the risk factor are particularly important and frequently appear in this area. In recent years, under the Siret Water Basin Administration, this parameter was permanently monitored, so we could do an analysis, which shows that the water temperature fluctuations, influenced by air temperature, lead to the emergence of the ice jam phenomenon. The present study aims to analyze the water temperature, as compared to the air temperature, and the effect of these components on the liquid flow regime (the values were recorded at the hydrological stations on the main course of the Bistrita River. The negative effects resulted from the ice jam phenomenon require developing methods of damage prevention and defense. The frost phenomena recorded after the construction of the Bicaz dam are analyzed in this article

  13. CAN FLUORIDATION AFFECT WATER LEAD LEVELS AND LEAD NEUROTOXICITY?

    Science.gov (United States)

    Recent reports have attempted to show that certain approaches to fluoridating potable water is linked to increased levels of lead(II) in the blood. We examine these claims in light of the established science and critically evaluate their significance. The completeness of nexafluo...

  14. Levels of trace elements in MWSS drinking water

    International Nuclear Information System (INIS)

    As a water supplier for the metropolis, vigilance over the water quality has not been taken for granted at the Metropolitan Waterworks and Sewerage System (MWSS). By the early 1980's, a control laboratory equipped with modern facilities had been set up to supplement the already existing control laboratory at Filter Plant II handling physical, chemical, bacteriological, biological and mineral analyses and examinations, efficiently. The new central laboratory is intended to monitor trace elements, organic constituents and other elements with health related impact so as to assure the consumers of a safe drinking water supply at all times. This presentation reviews the levels of trace element pollution in MWSS tap water, then and now, in justification of the rehabilitation projects along the distribution network, in the treatment plants and other pertinent innovations corresponding to budgeted capital outlays as invested by the system. (author)

  15. Experiments on steam generator water level swell and shrinkage

    International Nuclear Information System (INIS)

    Equipment that is one-tenth the size of the steam generators for the Westinghouse 900-MW(electric) nuclear power plants is used to study the swell and shrinkage of the water level. The cyclic aspect of level swell and shrinkage occurring during low-power operation of the nuclear power plants is realized by sequential steam dump valve control. Experimental results show that a simple mathematical model based on the amount of steam generated during depressurization provides a good approximation for predicting level swell and shrinkage. Steam generation also causes water movement between the downcomer area and the inner part of the vessel, the effect of which during the initial steam dump period is estimated and applied to adjust this model

  16. Internal gamma activity used for water level indication

    International Nuclear Information System (INIS)

    the monitoring of the water level in pressure vessels is endowed with high safety technical importance in all power plants with water cooled reactors. Such pressure vessels are the reactor, the steam generator and the pressurizer. Up to date the water level indication is realized with measuring systems which are based on the measurement of pressure differences. If there are boiling conditions then it exists ever the danger of relative great measuring faults caused by the void generation in the comparison tube during great negative pressure gradients. In order to undermine this faults in nuclear power plants there are some different systems measuring the pressure difference. But this isn't a methodical diversity. After the accident in TMI-2 worldwide activities there have been in order to develop other water level measuring methods which are showing the importance of the problems. One unconventional water level measuring method is based on the utilization of the internal gamma activity which exists in all pressure tanks reckoned up above. For the differ tanks are derived different measuring algorithms in reason of different properties of the gamma sources. But some principles are likewise valid for all applications. - The aim of these researches is the development of divers measuring systems for internal parameters of pressure vessels with the property that it should be used Out-core gamma detectors only. Those have the advantage of a smaller probability of destruction of the detectors in accidents in comparison to in-core detectors. Possible applications are the water level measurement in reactors and steam generators but the indication of core smelting too. For the fitting there is not the necessity of constructive modifications. - the results of the gamma measurement are connected with results of a pressure measurement or a pressure and temperature measurement in the tanks to determine the mixture level. - In order to eliminate the dependence on the gamma source strength on the reactor is used a composite detector. This detector is arranged at a point at which water level changes have not an influence on the detector signal. - The measuring algorithms are based on measurement of the N-16 radiation from the primary water. This measuring system have a time limitation regarding availability because the Nitrogen N-16 radiation exists during power operation and some minutes after shutdown only. But such a system is available for the most and most important situations. Many pressure vessels show strong internal gamma sources which can be used for water level measurement. Following two possibilities are described for such applications. Some experimental results are shown for one method. In summary: The water level measurement using the internal gamma activity is one way to get a divers measuring system to the difference pressure measurement. Through the elimination of gamma source properties through a comparison detector in section 2.2 or through the quotients forming in section 3.2 the chances for such a measuring system are very improved. Some experiments have been showed the aptitude of the comparison detector. The next works are going to carry out experiments on the zero power reactor for two phase state conditions and further on power reactors

  17. Radioactivity levels in waters and sediments from Van Lake / Turkey

    International Nuclear Information System (INIS)

    It is well known that natural radionuclides can be effective as tracers for the different processes controlling the distribution of elements dissolved and particulate phases in aquatic systems. Significant radiation doses to man can potentially occur following radioactive contamination of water bodies such as rivers, lakes and reservoirs. In the long term, radioactivity in the water body can remain at significant levels as a result of secondary contamination processes. The Van Lake is located at Eastern part of Turkey and it is largest Lake of Turkey. The purpose of this study is to measure natural radioactivity in the waters and sediments taken from along to shore of Van Lake. Total of 19 surface coast lake waters and 18 sediments samples were collected from Van Lake in dry season in 2005, in the first part of this Project. In surface lake water samples, pH, mV and conductivity values were measured and alkalinity content was determined titrimetrically. The uranium concentrations in the lake water samples were measured using uranium analyzer. Radioactivities related to gross radium isotopes, gross-? and gross-? radioactivity levels in the surface water were determined. Gross radium isotopes were separated using the barium sulphate co-precipitation method and then the radioactivity of gross radium isotopes was measured by ZnS(Ag) alpha scintillation counter. The correlation among measured parameters for water samples and concentrations of uranium and gross radium isotopes are also discussed. Natural radioactivity in the sediments was also determined by gamma spectrometer. The field and laboratory studies on this project are carried out

  18. Protein-fluctuation-induced water-pore formation in ion channel voltage-sensor translocation across a lipid bilayer membrane

    Science.gov (United States)

    Rajapaksha, Suneth P.; Pal, Nibedita; Zheng, Desheng; Lu, H. Peter

    2015-11-01

    We have applied a combined fluorescence microscopy and single-ion-channel electric current recording approach, correlating with molecular dynamics (MD) simulations, to study the mechanism of voltage-sensor domain translocation across a lipid bilayer. We use the colicin Ia ion channel as a model system, and our experimental and simulation results show the following: (1) The open-close activity of an activated colicin Ia is not necessarily sensitive to the amplitude of the applied cross-membrane voltage when the cross-membrane voltage is around the resting potential of excitable membranes; and (2) there is a significant probability that the activation of colicin Ia occurs by forming a transient and fluctuating water pore of ˜15 Å diameter in the lipid bilayer membrane. The location of the water-pore formation is nonrandom and highly specific, right at the insertion site of colicin Ia charged residues in the lipid bilayer membrane, and the formation is intrinsically associated with the polypeptide conformational fluctuations and solvation dynamics. Our results suggest an interesting mechanistic pathway for voltage-sensitive ion channel activation, and specifically for translocation of charged polypeptide chains across the lipid membrane under a transmembrane electric field: the charged polypeptide domain facilitates the formation of hydrophilic water pore in the membrane and diffuses through the hydrophilic pathway across the membrane; i.e., the charged polypeptide chain can cross a lipid membrane without entering into the hydrophobic core of the lipid membrane but entirely through the aqueous and hydrophilic environment to achieve a cross-membrane translocation. This mechanism sheds light on the intensive and fundamental debate on how a hydrophilic and charged peptide domain diffuses across the biologically inaccessible high-energy barrier of the hydrophobic core of a lipid bilayer: The peptide domain does not need to cross the hydrophobic core to move across a lipid bilayer.

  19. Do Estimates of Water Productivity Enhance Understanding of Farm-Level Water Management?

    Directory of Open Access Journals (Sweden)

    Dennis Wichelns

    2014-03-01

    Full Text Available Estimates of water productivity are appearing with increasing frequency in the literature pertaining to agronomy, water management, and water policy. Some authors report such estimates as one of the outcome variables of experiment station studies, while others calculate water productivities when comparing regional crop production information. Many authors suggest or imply that higher values of water productivity are needed to ensure that future food production goals are achieved. Yet maximizing water productivity might not be consistent with farm-level goals or with societal objectives regarding water allocation and management. Farmers in both rainfed and irrigated settings must address a complex set of issues pertaining to risk, uncertainty, prices, and opportunity costs, when selecting activities and determining optimal strategies. It is not clear that farmers in either setting will or should choose to maximize water productivity. Upon examining water productivity, both conceptually and empirically, using published versions of crop production functions, I conclude that estimates of water productivity contain too little information to enhance understanding of farm-level water management.

  20. Effects of Water Levels on Productivity of Canada Geese in the Northern Flathead Valley, 1984 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Daniel

    1985-02-01

    Operation of Hungry Horse Dam on the South Fork Flathead River causes sporadic level fluctuations along the main stem Flathead River. Seasonal water level fluctuations and substantial habitat losses have occurred as a result of construction and operation of Kerr Dam, which regulates Flathead Lake. These fluctuations may impact goose populations through flooding or erosion of nesting and brood-rearing habitats, and increased susceptibility of nests and young to predation. The number, location, and success of goose nests were determined through pair surveys and nest searches. Counts of indicated pairs suggest there were 73-125 occupied nests in the study area; 44 were located in 1984. Twenty were island ground nests, 19 were tree nests, and 5 were on man-made structures. Hatching success was 76 percent. Sixty-one percent of all nests were in deciduous forest habitat; 87 percent were on riparian bench or island landforms. Seventy-four percent of all nests were within 5 m of the seasonal high water mark (HWM) and 85 percent of ground nests were 1 m or less above the HWM. Production, habitat use, and distribution of broods were documented through aerial, boat, ground, and observation tower surveys. 28 refs., 10 figs., 4 tabs.

  1. Analytical approach for predicting fresh water discharge in an estuary based on tidal water level observations

    OpenAIRE

    Cai, H; Savenije, H. H. G.; Jiang, C

    2014-01-01

    As the tidal wave propagates into an estuary, the tidally averaged water level tends to rise in landward direction due to the density difference between saline and fresh water and the asymmetry of the friction. The effect of friction on the residual slope is even more remarkable when accounting for fresh water discharge. In this study, we investigate the influence of river discharge on tidal wave propagation in the Yangtze estuary with specific attention to ...

  2. Quality Level of Bottled Drinking Water Consumed in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Ashraf E.M. Khater

    2014-01-01

    Full Text Available The quality of drinking water is a universal health concern and access to safe water is a fundamental human right. Many national and international organizations set certain parameters and levels for Bottled Drinking Water (BDW to ensure their quality. The present work aims to analyze the quality of various brands of BDW used in Saudi Arabia and to compare the quality levels to the BDW standards. One hundred and twenty six samples of 54 different BDW brands were collected from the Saudi market. The quality level parameters were analyzed using portable meters for pH, EC and TDS; spectrophotometer, HACH DR-2800 for F, SO4 and NO3; Inductively Coupled Plasma (ICP Mass Spectrometer (MS and atomic emission spectrometer (AES for elemental analysis. To evaluate the quality level parameters of BDW, the parameters were classified as following: (1 Parameters and substances affect the quality of BDW (pH, EC, TDS, HCO3, F, NO3 and SO4. (2 Macronutrients (Ca, K, Mg and Na. (3 Micronutrients-trace elements (Co, Cr, Cu, Fe, Mo, Se and Zn, (4 Potentially essential elements that have some beneficial health effects (B, Mn, Ni and V and (5 Toxic elements (Al, As, Cd, Hg, Pb, Th and U using Inductively coupled plasma-mass spectrometry, ICP-MS. The concentrations of the detected elements were compared with the Golf and international standard like World Health Organization.

  3. Quadratic controller syntheses for the steam generator water level

    International Nuclear Information System (INIS)

    The steam generator water level, (SGWL), control problem in the pressurized water reactor of a nuclear power plant is considered from robust control techniques point of view. The plant is a time-varying system with a non minimum phase behavior and an unstable open-loop response. The time-varying nature of the plant due to change in operating power is taken into account by including slowly time-varying uncertainty in the model. A linear Time-Invariant, (LTI) guaranteed cost quadratic stabilizing controller is designed in order to address some of the particular issues arising for such a control problem. (author)

  4. Holocene lake level fluctuations of a small alpine lake in the Qilian Mountains, NW China: a comparison of chironomid, ostracod, pollen and geochemistry data.

    Science.gov (United States)

    Mischke, S.; Herzschuh, U.

    2003-04-01

    A core of 14 m length was drilled in a small alpine lake in the Qilian Mountains, NW China. The lake Luanhaizi has a drainage area of about 30 km2 and is situated at an altitude of 3200 m which represents the altitude of the present regional upper timberline. Due to the small size of the open-basin lake (surface area about 1 km2) and the sharply outlined catchment area the lake is regarded as a very sensitively and rapidly responding ecosystem. Analyses of ostracod shells, head capsules of larval chironomids and pollen and spores were conducted and the organic and carbonate content (LOI), element concentrations and magnetic susceptibility of core samples determined. Ostracod taxa mainly comprise Candona candida, C. neglecta, C. rawsoni, Cyclocypris ovum, Cypridopsis vidua, Fabaeformiscandona caudata, F. danielopoli, F. hyalina, Herpetocypris chevreuxi, Heterocypris salina, Ilyocypris cf. bradyi, I. echinata, I. lacustris and Limnocythere inopinata. They may be used to distinguish periods of low lake levels corresponding to a dense cover of aquatic plants at the lake bottom from stages of higher lake levels and a corresponding decrease in macrophytes at the core site. Chironomid taxa belonging to Chironomus, Cladopelma, Glyptotendipes, Micropsectra, Paratanytarsus, Polypedilum, Psectrocladius and Tanytarsus further provide information on variations in benthic oxygen availability and lake level fluctuations. Several units of the core show high abundances of pollen and spores of higher aquatic and wetland plants and fungi (Cyperaceae, Hippuris, Myriophyllum and Glomus) indicating low lake levels. In contrast, algae such as Botryococcus, Pediastrum and Tetraedron were regarded to reflect higher water levels. Typha angustifolia-type, Typha latifolia, Alisma and Potamogeton were recorded in low abundances as well. The organic content of core samples averages 6 % displaying four alternating stages of distinct minima and maxima. Lowest values of about 1 % occur at the core base whereas the organic content rises to 16 % at maximum near the top. The carbonate content displays a similar pattern with strong shifts ranging from 3 to 31%. The results of the investigation of the sediment core from the alpine lake in the Qilian Mountains were presented and the validity of single proxies with respect to lake level changes discussed.

  5. Effects of Water Levels on Productivity of Canada Geese in the Northern Flathead Valley, 1985 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Daniel

    1986-04-01

    Operation of Hungry Horse Dam on the South Fork Flathead River causes sporadic water level fluctuations along the main stem Flathead River. Changes in chronology of seasonal water level fluctuations and substantial habitat losses have occurred as a result of construction and operation of Kerr Dam, which regulates Flathead Lake. These fluctuations may impact goose populations through flooding and erosion of nesting and brood-rearing habitats, and increased susceptibility of nests and young to predation. The number, location, and success of goose nests were determined through pair surveys and nest searches. Our 1985 pair count data indicated that 95 to 143 nests may have been present. Hatching success for 1985 nests (55%) was low compared to long-term averages for the region. Predation was the predominant cause of ground nest failure (25 nests); we documented 2 nest failures due to flooding. The maximum gosling count in the study area for 1985 was 197. Six key brood-rearing areas were identified. Most (80%) sites were located in the herbaceous or pasture cover type and the riparian bench landform. Analysis of aerial photographs taken prior to construction of Kerr Dam documented the loss of 1859 acres of habitat along the north shore of Flathead Lake. Losses were attributed to inundation and to continuing erosion due to operation of Kerr Dam. Lake and river water level regimes were compared with the chronology of important periods in the nesting cycle. Low lake levels in May and early June coincide with the breed-rearing period. Mudflats are heavily used by broods, but their effect on survival must still be documented. Preliminary recommendations to protect and enhance Canada goose habitat and production are being developed.

  6. Biodegradation of Toluene Under Seasonal and Diurnal Fluctuations of Soil-Water Temperature

    OpenAIRE

    Yadav, Brijesh K.; Shrestha, Shristi R.; Hassanizadeh, S. Majid

    2012-01-01

    An increasing interest in bioremediation of hydrocarbon polluted sites raises the question of the influence of seasonal and diurnal changes on soil-water temperature on biodegradation of BTEX, a widespread group of (sub)-surface contaminants. Therefore, we investigated the impact of a wide range of varying soil-water temperature on biodegradation of toluene under aerobic conditions. To see the seasonal impact of temperature, three sets of batch experiments were conducted at three different co...

  7. Analytical approach for predicting fresh water discharge in an estuary based on tidal water level observations

    Directory of Open Access Journals (Sweden)

    H. Cai

    2014-06-01

    Full Text Available As the tidal wave propagates into an estuary, the tidally averaged water level tends to rise in landward direction due to the density difference between saline and fresh water and the asymmetry of the friction. The effect of friction on the residual slope is even more remarkable when accounting for fresh water discharge. In this study, we investigate the influence of river discharge on tidal wave propagation in the Yangtze estuary with specific attention to residual water level slope. This is done by using a one-dimensional analytical model for tidal hydrodynamics accounting for the residual water level. We demonstrate the importance of the residual slope on tidal dynamics and use it to improve the prediction of the tidal propagation in estuaries (i.e., tidal damping, velocity amplitude, wave celerity and phase lag, especially when the influence of river discharge is significant. Finally, we develop a new inverse analytical approach for estimating fresh water discharge on the basis of tidal water level observations along the estuary, which can be used as a tool to obtain information on the river discharge that is otherwise difficult to measure in the tidal region.

  8. Water levels and water quality in the Mississippi River Valley alluvial aquifer in eastern Arkansas, 2012

    Science.gov (United States)

    Schrader, Tony P.

    2015-01-01

    During the spring of 2012, the U.S. Geological Survey, in cooperation with the Arkansas Natural Resources Commission and the Arkansas Geological Survey, measured water levels in 342 wells completed in the Mississippi River Valley alluvial aquifer in eastern Arkansas. The Arkansas Natural Resources Commission measured water levels in 11 wells, and the U.S. Department of Agriculture-Natural Resources Conservation Service measured water levels in 239 wells completed in the alluvial aquifer and provided these data to the Arkansas Natural Resources Commission. In 2010, estimated water withdrawals from the alluvial aquifer in Arkansas totaled about 7,592 million gallons per day. Withdrawals more than doubled between 1985 and 2010, about a 115-percent increase.

  9. Monitoring the Fluctuation of Lake Qinghai Using Multi-Source Remote Sensing Data

    OpenAIRE

    Wenbin Zhu; Shaofeng Jia; Aifeng Lv

    2014-01-01

    The knowledge of water storage variations in ungauged lakes is of fundamental importance to understanding the water balance on the Tibetan Plateau. In this paper, a simple framework was presented to monitor the fluctuation of inland water bodies by the combination of satellite altimetry measurements and optical satellite imagery without any in situ measurements. The fluctuation of water level, surface area, and water storage variations in Lake Qinghai were estimated to demonstrate this framew...

  10. The Water Level Fall of Lake Megali Prespa (N Greece): an Indicator of Regional Water Stress Driven by Climate Change and Amplified by Water Extraction?

    Science.gov (United States)

    van der Schriek, Tim; Giannakopoulos, Christos

    2014-05-01

    The Mediterranean stands out globally due to its sensitivity to (future) climate change, with future projections predicting an increase in excessive drought events and declining rainfall. Regional freshwater ecosystems are particularly threatened: precipitation decreases, while extreme droughts increase and human impacts intensify (e.g. water extraction, drainage, pollution and dam-building). Many Mediterranean lake-wetland systems have shrunk or disappeared over the past two decades. Protecting the remaining systems is extremely important for supporting global biodiversity and for ensuring sustainable water availability. This protection should be based on a clear understanding of lake-wetland hydrological responses to natural and human-induced changes, which is currently lacking in many parts of the Mediterranean. The interconnected Prespa-Ohrid Lake system is a global hotspot of biodiversity and endemism. The unprecedented fall in water level (~8m) of Lake Megali Prespa threatens this system, but causes remain debated. Modelling suggests that the S Balkan will experience rainfall and runoff decreases of ~30% by 2050. However, projections revealing the potential impact of these changes on future lake level are unavailable as lake regime is not understood. A further drop in lake level may have serious consequences. The Prespa Lakes contribute ~25% of the total inflow into Lake Ohrid through underground karst channels; falling lake levels decrease this discharge. Lake Ohrid, in turn, feeds the Drim River. This entire catchment may therefore be affected by falling lake levels; its water resources are of great importance for Greece, Albania, FYROM and Montenegro (e.g. tourism, agriculture, hydro-energy, urban & industrial use). This new work proves that annual water level fluctuations of Lake Megali Prespa are predominantly related to precipitation during the first 7 months (Oct-Apr) of the hydrological year (Oct-Sep). Lake level is very sensitive to regional and Mediterranean wet-dry events during this period. There are robust indications for a link between lake level and the North Atlantic Oscillation, which is known to strongly influence Mediterranean winter precipitation. Hydro-climatic records show a complicated picture, but tentatively support the conclusion that the unprecedented lake level fall is principally related to climate change. The available fluvial discharge record and most existing snowfall records show statistically significant decreases in annual averages. Annual rainfall only shows a statistically significant decrease of the 25th percentile; 7-month rainfall (Oct-Apr) additionally shows a statistically significant but non-robust decrease of the mean. The modest amount of water extraction (annually: ~14*103m3, ~0.004% of total lake volume) exerts a progressive and significant impact on lake level over the longer term, accounting for ~25% of the observed fall. Lake level lowering ends when lake-surface area shrinkage has led to a decrease in lake-surface evaporation that is equivalent to the amount of water extracted. The adjustment of lake level to stable extraction rates requires two to three decades. This work aims to steer adaptation and mitigation strategies by informing on lake response under different climate change and extraction scenarios. Lake protection is a cost effective solution for supporting global biodiversity and for providing sustainable water resources.

  11. The study and improvement of water level control of pressurizer

    International Nuclear Information System (INIS)

    The PI controller which is used widely in water level control of pressurizer in reactor control system usually leads dynamic overshoot and long setting time. The improvement project for intelligent fuzzy controller to take the place of PI controller is advanced. This paper researches the water level control of pressurizer in reactor control system of Daya Bay Phase I, and describes the method of intelligent fuzzy control in practice. Simulation indicates that the fuzzy control has advantages of small overshoot and short settling time. It can also improve control system's real time property and anti-interference ability. Especially for non-linear and time-varying complicated control systems, it can obtain good control results. (authors)

  12. Investigation of natural radioactivity levels in water around Kadugli, Sudan

    International Nuclear Information System (INIS)

    Surface water from Miri Lake and groundwater from around Kadugli (West-Central Sudan) obtained by means of hand-pumps was analysed for 238U, 226Ra, 222Rn, and 232Th activity concentrations. The surface water showed very low levels of radionuclide concentrations: -1 for 238U, 226Ra, 222Rn, and 232Th, respectively. Groundwater revealed a significant amount of natural radioactivity (16.1-1720, 7.7-14.3, 3000-139,000, -1) respectively. The overall annual effective dose was below the WHO reference dose level of 0.1 mSv yr-1 except in one groundwater sample with an associated dose of 0.7 mSv yr-1

  13. Wave-induced mass transport affects daily Escherichia coli fluctuations in nearshore water

    Science.gov (United States)

    Ge, Zhongfu; Whitman, Richard L.; Nevers, Meredith B.; Phanikumar, Mantha S.

    2012-01-01

    Characterization of diel variability of fecal indicator bacteria concentration in nearshore waters is of particular importance for development of water sampling standards and protection of public health. Significant nighttime increase in Escherichia coli (E. coli) concentration in beach water, previously observed at marine sites, has also been identified in summer 2000 from fixed locations in waist- and knee-deep waters at Chicago 63rd Street Beach, an embayed, tideless, freshwater beach with low currents at night (approximately 0.015 m s–1). A theoretical model using wave-induced mass transport velocity for advection was developed to assess the contribution of surface waves to the observed nighttime E. coli replenishment in the nearshore water. Using average wave conditions for the summer season of year 2000, the model predicted an amount of E. coli transported from water of intermediate depth, where sediment resuspension occurred intermittently, that would be sufficient to have elevated E. coli concentration in the surf and swash zones as observed. The nighttime replenishment of E. coli in the surf and swash zones revealed here is an important phase in the cycle of diel variations of E. coli concentration in nearshore water. According to previous findings in Ge et al. (Environ. Sci. Technol. 2010, 44, 6731–6737), enhanced current circulation in the embayment during the day tends to displace and deposit material offshore, which partially sets up the system by the early evening for a new period of nighttime onshore movement. This wave-induced mass transport effect, although facilitating a significant base supply of material shoreward, can be perturbed or significantly influenced by high currents (orders of magnitude larger than a typical wave-induced mass transport velocity), current-induced turbulence, and tidal forcing.

  14. Conformational fluctuations of a protein-DNA complex and the structure and ordering of water around it

    Science.gov (United States)

    Sinha, Sudipta Kumar; Bandyopadhyay, Sanjoy

    2011-12-01

    Protein-DNA binding is an important process responsible for the regulation of genetic activities in living organisms. The most crucial issue in this problem is how the protein recognizes the DNA and identifies its target base sequences. Water molecules present around the protein and DNA are also expected to play an important role in mediating the recognition process and controlling the structure of the complex. We have performed atomistic molecular dynamics simulations of an aqueous solution of the protein-DNA complex formed between the DNA binding domain of human TRF1 protein and a telomeric DNA. The conformational fluctuations of the protein and DNA and the microscopic structure and ordering of water around them in the complex have been explored. In agreement with experimental studies, the calculations reveal conformational immobilization of the terminal segments of the protein on complexation. Importantly, it is discovered that both structural adaptations of the protein and DNA, and the subsequent correlation between them to bind, contribute to the net entropy loss associated with the complex formation. Further, it is found that water molecules around the DNA are more structured with significantly higher density and ordering than that around the protein in the complex.

  15. The effect of water level fluctuation on tributary spawning migration of reservoir fish.

    Czech Academy of Sciences Publication Activity Database

    Hladík, Milan; Kube?ka, Jan

    2004-01-01

    Ro?. 4, ?. 4 (2004), s. 449-457. ISSN 1642-3593. [Ecohydrology and physical habitat modifications in lakes . Mondsee, 26.11.2003-28.11.2003] R&D Projects: GA ?R(CZ) GA206/02/0520; GA AV ?R(CZ) IBS6017004; GA AV ?R(CZ) IAA6017201; GA AV ?R(CZ) KSK6005114 Institutional research plan: CEZ:AV0Z6017912 Keywords : freshwater fish spawning migration * tributary * reservoir Subject RIV: GL - Fish ing

  16. Impacts of Water Level Fluctuations on Kokanee Reproduction in Flathead Lake, 1985 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Beattie, Will; Fraley, John J.; Decker-Hess, Janet (Montana Department of Fish, Wildlife and Parks, Kalispell, MT)

    1986-06-01

    This study has investigated the effects of the operation of Kerr Dam on the reproductive success of kokanee that spawn along the shores of Flathead Lake. We have estimated the spawning escapement to the lakeshore, characterized spawning habitat, monitored egg and alevin survival in redds, and related survival to length of redd exposure due to lake drawdown. Groundwater discharge apparently attracts kokanee to spawning sites along the lakeshore and is responsible for prolonging egg survival in redds above minimum pool. We have quantified and described the effect of lake drawdown on groundwater flux in spawning areas. This report defines optimal lakeshore spawning habitat and discusses eqg and alevin survival both in and below the varial zone.

  17. Dendrochronological evaluation of historic changes in Lake Stirniai (Lithuania) water level

    International Nuclear Information System (INIS)

    Full text: Dendrochronological research was carried out on Pinus sylvestris L. timber extracted from Lake Stirniai (55o15'04'' latitude (N) and 25o38'49'' longitude (E)). As a result, the tree ring width floating chronology spanning 213 years was compiled. Radiocarbon dating of the samples indicated that pines grew from 1103 ± 80 AD to 1315 ± 80 AD. Fragments of stems and roots of pines were found waterlogged in 1 m water layer. It means that in the Medieval Warm Period, the ground water level in the habitat of archaeological pines was below the nowadays lake level for at least by 1 m. The growth conditions became unfavourable in ? 1270 ± 80 AD. At the end of the 13th century the climate became damper, lake transgression started, the trees of Scots pine became dry. The basic cause of transgression seems to be the bogged bed of the rivulet Stirna flowing out of the lake. This phenomenon was caused by the changed climate conditions. The formant analysis of the radial increase of the stems of archaeological Scots pine in Lake Stirniai revealed 52.9; 30.3; 21.1; 17.5; 15.0; 11.2 year long-term fluctuation cycles. Comparison of the obtained data with the present cycles is foreseen. (author)

  18. Reservoir Computing approach to Great Lakes water level forecasting

    Science.gov (United States)

    Coulibaly, Paulin

    2010-02-01

    SummaryThe use of echo state network (ESN) for dynamical system modeling is known as Reservoir Computing and has been shown to be effective for a number of applications, including signal processing, learning grammatical structure, time series prediction and motor/system control. However, the performance of Reservoir Computing approach on hydrological time series remains largely unexplored. This study investigates the potential of ESN or Reservoir Computing for long-term prediction of lake water levels. Great Lakes water levels from 1918 to 2005 are used to develop and evaluate the ESN models. The forecast performance of the ESN-based models is compared with the results obtained from two benchmark models, the conventional recurrent neural network (RNN) and the Bayesian neural network (BNN). The test results indicate a strong ability of ESN models to provide improved lake level forecasts up to 10-month ahead - suggesting that the inherent structure and innovative learning approach of the ESN is suitable for hydrological time series modeling. Another particular advantage of ESN learning approach is that it simplifies the network training complexity and avoids the limitations inherent to the gradient descent optimization method. Overall, it is shown that the ESN can be a good alternative method for improved lake level forecasting, performing better than both the RNN and the BNN on the four selected Great Lakes time series, namely, the Lakes Erie, Huron-Michigan, Ontario, and Superior.

  19. Primary collector wall local temperature fluctuations in the area of water-steam phase boundary

    Energy Technology Data Exchange (ETDEWEB)

    Matal, O.; Klinga, J.; Simo, T. [Energovyzkum Ltd., Brno (Switzerland)

    1995-12-31

    A limited number of temperature sensors could be installed at the primary collector surface in the area of water - steam phase boundary. The surface temperatures as well WWER 440 steam generator process data were measured and stored for a long time and off-line evaluated. Selected results are presented in the paper. (orig.). 2 refs.

  20. Measurement of Temperature Fluctuations in Plasma JET the Water Stabilized DC Arc Torch.

    Czech Academy of Sciences Publication Activity Database

    Sember, Viktor; Hlína, Jan; Kopecký, Vladimír

    Vol. 1. New Jersey : Stevens Institute of Technology, 1995 - (Becker, K.; Carr, E.; Kunhardt, E.) [International Conference on Phenomena in Ionized Gases /22./. New-Jersey (US), 31.07.1995-04.08.1995] R&D Projects: GA ?R GA102/95/0592 Keywords : water stabilized * plasma

  1. Lake Fluctuation Effectively Regulates Wetland Evapotranspiration: A Case Study of the Largest Freshwater Lake in China

    OpenAIRE

    Xiaosong Zhao; Yuanbo Liu

    2014-01-01

    Lakes and wetlands provide valuable water resources. Wetland evapotranspiration (ET) is a key hydrologic component; however, the effects of lake fluctuation on wetland ET remain unclear. The Poyang Lake is the largest freshwater lake in China and experiences a dramatic fluctuation in water level and inundated area. This study used remote sensing data to estimate the wetland ET for Poyang Lake and to illustrate the distribution of wetland ET and its response to lake fluctuations. Our results s...

  2. CRC technology of nozzle. Water level instrumentation nozzle

    International Nuclear Information System (INIS)

    Inconel 182 is used for welding joint material between Reactor Pressure Vessel (RPV) nozzle and nozzle safe-end in nuclear power plants (Nozzle indicates an only water level instrumentation nozzle in this paper). Corrosion Resistant Cladding (CRC) is the method which is welded a Stress Corrosion Cracking (SCC) resistant material cladding to the welding joint portion. Still more CRC technology is applied to the internal surface of nozzle made of Inconel 600 which is known to have SCC sensitivity. This technology prevents from the SCC initiation of material. In actual work after cutting nozzle safe-end, small-sized welding machine is put into the nozzle whose inside diameter is about 50 mm. These nozzles are installed at the three different levels of RPV. In case of the lowest nozzle, which placed near the core, it is necessary to build the shielding blocks outside RPV, and keep the reactor water in the vessel to protect workers' radiation exposure. Therefore a water-proof working box is installed around nozzle area inside RPV to perform CRC in dry environment. This technology had been applied to a couple of operating plants. (author)

  3. Two-level system with a thermally fluctuating transfer matrix element: Application to the problem of DNA charge transfer

    International Nuclear Information System (INIS)

    Charge transfer along the base-pair stack in DNA is modeled in terms of thermally assisted tunneling between adjacent base pairs. The key element of the approach in this paper is the notion that this tunneling between base pairs that fluctuate significantly from their nominal orientation is rate limited by the requirement of optimal alignment. We focus on this aspect of the process by modeling two adjacent base pairs in terms of a classical damped oscillator subject to thermal fluctuations as described by a Fokker-Planck equation. We find that the process is characterized by two time scales, a result that is in accord with the experimental findings

  4. Processing of water level derived from water pressure data at the Time Series Station Spiekeroog

    Science.gov (United States)

    Holinde, L.; Badewien, T. H.; Freund, J. A.; Stanev, E. V.; Zielinski, O.

    2015-04-01

    The quality of water level time series data strongly varies with periods of high and low quality sensor data. In this paper we are presenting the processing steps which were used to generate high quality water level data from water pressure measured at the Time Series Station (TSS) Spiekeroog. The TSS is positioned in a tidal inlet between the islands of Spiekeroog and Langeoog in the East Frisian Wadden Sea (southern North Sea). The processing steps will cover sensor drift, outlier identification, interpolation of data gaps and quality control. A central step is the removal of outliers. For this process an absolute threshold of 0.25 m/10 min was selected which still keeps the water level increase and decrease during extreme events as shown during the quality control process. A second important feature of data processing is the interpolation of gappy data which is accomplished with a high certainty of generating trustworthy data. Applying these methods a 10 years dataset of water level information at the TSS was processed and the results were submitted to WDC MARE data base system PANGAEA (pangaea.de/10.1594/PANGAEA.843740" target=_blank">http://doi.pangaea.de/10.1594/PANGAEA.843740).

  5. A Validated Model to Predict Microalgae Growth in Outdoor Pond Cultures Subjected to Fluctuating Light Intensities and Water Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Huesemann, Michael H.; Crowe, Braden J.; Waller, Peter; Chavis, Aaron R.; Hobbs, Samuel J.; Edmundson, Scott J.; Wigmosta, Mark S.

    2016-01-05

    A microalgae biomass growth model was developed for screening novel strains for their potential to exhibit high biomass productivities under nutrient-replete conditions in outdoor ponds subjected to fluctuating light intensities and water temperatures. Growth is modeled by first estimating the light attenuation by biomass according to a scatter-corrected Beer-Lambert Law, and then calculating the specific growth rate in discretized culture volume slices that receive declining light intensities due to attenuation. The model requires the following experimentally determined strain-specific input parameters: specific growth rate as a function of light intensity and temperature, biomass loss rate in the dark as a function of temperature and average light intensity during the preceding light period, and the scatter-corrected biomass light absorption coefficient. The model was successful in predicting the growth performance and biomass productivity of three different microalgae species (Chlorella sorokiniana, Nannochloropsis salina, and Picochlorum sp.) in raceway pond cultures (batch and semi-continuous) subjected to diurnal sunlight intensity and water temperature variations. Model predictions were moderately sensitive to minor deviations in input parameters. To increase the predictive power of this and other microalgae biomass growth models, a better understanding of the effects of mixing-induced rapid light dark cycles on photo-inhibition and short-term biomass losses due to dark respiration in the aphotic zone of the pond is needed.

  6. Considering rating curve uncertainty in water level predictions

    Science.gov (United States)

    Sikorska, A. E.; Scheidegger, A.; Banasik, K.; Rieckermann, J.

    2013-11-01

    Streamflow cannot be measured directly and is typically derived with a rating curve model. Unfortunately, this causes uncertainties in the streamflow data and also influences the calibration of rainfall-runoff models if they are conditioned on such data. However, it is currently unknown to what extent these uncertainties propagate to rainfall-runoff predictions. This study therefore presents a quantitative approach to rigorously consider the impact of the rating curve on the prediction uncertainty of water levels. The uncertainty analysis is performed within a formal Bayesian framework and the contributions of rating curve versus rainfall-runoff model parameters to the total predictive uncertainty are addressed. A major benefit of the approach is its independence from the applied rainfall-runoff model and rating curve. In addition, it only requires already existing hydrometric data. The approach was successfully demonstrated on a small catchment in Poland, where a dedicated monitoring campaign was performed in 2011. The results of our case study indicate that the uncertainty in calibration data derived by the rating curve method may be of the same relevance as rainfall-runoff model parameters themselves. A conceptual limitation of the approach presented is that it is limited to water level predictions. Nevertheless, regarding flood level predictions, the Bayesian framework seems very promising because it (i) enables the modeler to incorporate informal knowledge from easily accessible information and (ii) better assesses the individual error contributions. Especially the latter is important to improve the predictive capability of hydrological models.

  7. Uranium Redistribution Due to Water Table Fluctuations in Sandy Wetland Mesocosms

    Science.gov (United States)

    To understand better the fate and stability of immobilized uranium (U) in wetland sediments, and how intermittent dry periods affect U stability, we dosed saturated wetland mesocosms planted with Scirpus acutus with low levels of uranyl acetate for 4 months before imposing...

  8. Screening Experiments for Removal of Low-Level Tritiated Water

    International Nuclear Information System (INIS)

    Screening experiments for low levels of tritiated water (HTO) remediation based upon selective adsorption/desorption mechanisms utilizing equilibrium isotope effects have been carried out. Several organic and inorganic high surface area materials were investigated to assess their ability to selectively adsorb low concentrations of HTO. Ion-exchange resins with cation functionalities, chitosan, sodium alginate, and several inorganic media modified with metal cations exhibited promising results. Biomaterials, for example, chitosan and modified alginate, demonstrated positive results. Based on the literature and our preliminary testing, we postulate four possible mechanisms for selected tritium adsorption: hydrogen ion exchange, HTO coordination with surface cation sites, hydrogen bonding to surface basic sites, and secondary hydrogen bonding (structural water) in fine pores

  9. Phylogeography of the Mekong mud snake (Enhydris subtaeniata): the biogeographic importance of dynamic river drainages and fluctuating sea levels for semiaquatic taxa in Indochina

    OpenAIRE

    Lukoschek, Vimoksalehi; Osterhage, Jennifer L; Karns, Daryl R; Murphy, John C.; Voris, Harold K

    2011-01-01

    During the Cenozoic, Southeast Asia was profoundly affected by plate tectonic events, dynamic river systems, fluctuating sea levels, shifting coastlines, and climatic variation, which have influenced the ecological and evolutionary trajectories of the Southeast Asian flora and fauna. We examined the role of these paleogeographic factors on shaping phylogeographic patterns focusing on a species of semiaquatic snake, Enhydris subtaeniata (Serpentes: Homalopsidae) using sequence data from three ...

  10. An Indirect Adaptive Controller to Regulate UTSG Water Level in Pressurized Water Nuclear Reactor

    Directory of Open Access Journals (Sweden)

    Djamel Boukhetala

    2012-01-01

    Full Text Available Stabilizing water level of the Steam Generator (SG in nuclear power plant is a very important problem since its parameters vary with operating conditions and dynamics of the system is very different according to the power levels and changes as time goes on. Therefore, it is an intractable as well as challenging task to improve the water level control system of the SG. In this study, a new framework for building an adaptive Minimum Variance controller for stabilizing water-level of SG is proposed. We use the recursive least squares algorithm to identify the Input/Output models. Minimum Variance Control (MVC law is also used to develop the adaptation controller. Emphasis is put on the evaluation of the parameter identification in order to avoid instabilities because of disturbances or insufficient excitations. This is especially of importance when the adaptive control is carried out in closed loop systems and without additional test signals. The algorithm so proposed is simulated and applied to the water level control in the U-Tube Steam Generating unit (UTSG used for electricity generation. It is shown through application to a nonlinear model of steam generators that the proposed controller has good performance.

  11. Response of the Apodi-Mossoró estuary-incised valley system (NE Brazil to sea-level fluctuations

    Directory of Open Access Journals (Sweden)

    Helenice Vital

    2010-01-01

    Full Text Available This study focuses on the Quaternary sea level changes in the Apodi-Mossoró Estuary and adjacent shelf, Northeastern Brazil, based on the analysis of high-resolution seismic profiles, integrated with echosounder, SRTM and satellite image data. We use these data to develop a relative stratigraphy. An incised-valley extending from the Apodi-Mossoró Estuary onto the shelf dominates the investigated area. In very shallow waters (down to 10 m depth the channel lies mainly in a NW-SE direction, changing to NE-SW in waters below10 m, in the form of a J-shaped valley. The southern flank of the shallow channel presents an abrupt morphology, probably determined by a residual scarp due to neotectonic reactivation of a pre-existing fault. This incised-valley can be correlated with a former river valley formed during the late Pleistocene fall in sea-level. The base-level change related to this drop in sea level can be regionally expressed on seismic lines as a laterally-continuous stratigraphic surface named Horizon I, interpreted as representing the sub-aerial exposure of the continental shelf. Many incised valleys were excavated on this exposed shelf, including that of the Apodi-Mossoró Estuary and its incised valley system. This incised valley has lain buried since the Holocene transgression. The Holocene sediments present sub-horizontal layers, or they have filled the incised valley with oblique features.Este estudo utiliza a integração de dados sísmicos de alta resolução, batimétricos, SRTM e imagens de satélite para desenvolvimento da estratigrafia relativa visando entender as variações do nível do mar durante o Quaternário no estuário do rio Apodi-Mossoró e plataforma adjacente, nordeste do Brasil. A principal feição identificada foi um canal submerso, na plataforma interna, parcialmente preenchido, provavelmente relacionado com o sistema de vales incisos formado durante o rebaixamento do nível do mar no Pleistoceno. O canal apresenta duas direções principais (NW-SE e NE-SW, em forma da letra J, aparentemente controladas pelas estruturas tectônicas da Bacia Potiguar. A margem oeste do canal é relativamente soerguida em relação à margem leste. Com base nos dados sísmicos foi possível identificar uma descontinuidade presente em toda a área, interpretada como o limite Pleistoceno/Holoceno, bem como sismofácies referentes a padrões de preenchimento e sedimentação do canal submerso e da plataforma durante a subida do nível do mar no Holoceno.

  12. Fractal water quality fluctuations spanning the periodic table in an intensively farmed watershed.

    Science.gov (United States)

    Aubert, Alice H; Kirchner, James W; Gascuel-Odoux, Chantal; Faucheux, Mikael; Gruau, Gérard; Mérot, Philippe

    2014-01-21

    Recently developed measurement technologies can monitor surface water quality almost continuously, creating high-frequency multiparameter time series and raising the question of how best to extract insights from such rich data sets. Here we use spectral analysis to characterize the variability of water quality at the AgrHys observatory (Western France) over time scales ranging from 20 min to 12 years. Three years of daily sampling at the intensively farmed Kervidy-Naizin watershed reveal universal 1/f scaling for all 36 solutes, yielding spectral slopes of 1.05 ± 0.11 (mean ± standard deviation). These 36 solute concentrations show varying degrees of annual cycling, suggesting different controls on watershed export processes. Twelve years of daily samples of SO4, NO3, and dissolved organic carbon (DOC) show that 1/f scaling does not continue at frequencies below 1/year in those constituents, whereas a 12-year daily record of Cl shows a general 1/f trend down to the lowest measurable frequencies. Conversely, approximately 12 months of 20 min NO3 and DOC measurements show that at frequencies higher than 1/day, the spectra of these solutes steepen to slopes of roughly 3, and at time scales shorter than 2-3 h, the spectra flatten to slopes near zero, reflecting analytical noise. These results confirm and extend the recent discovery of universal fractal 1/f scaling in water quality at the relatively pristine Plynlimon watershed in Wales, further demonstrating the importance of advective-dispersive transport mixing in catchments. However, the steeper scaling at subdaily time scales suggests additional short-term damping of solute concentrations, potentially due to in-stream or riparian processes. PMID:24328425

  13. The Organochlorine Pesticides Residue Levels in Karun River Water

    Directory of Open Access Journals (Sweden)

    Behrooz Jannat

    2013-01-01

    Full Text Available Background: The organochlorine pesticides (OCPs are among the most commonly used in water streams around the world. Most of these contaminants are highly hydrophobic and persist in sediments of rivers and lakes. Studies have suggested that OCPs may affect the normal function of the human and wildlife endocrine systems.Objectives: The aim of this study is to determine the concentrations of selected organochlorine pesticides residues [OP'DDT, PP'DDT, alderin, dieldrin, heptachlor, (?,ß,?,? HCH, (?, ß endosulfan and metoxychlor] in samples from Karun River water at Khuzestan province in Iran , by GC-µ-ECD.Materials and Methods: Water was extracted with n-hexane and then purified by passing through a glass column packed with Florisil and Na2SO4, which was then eluted with ether: hexane solution v/v.Results: In general, all of 12 investigated organochlorine pesticides (OCPs were detected. Regardless of the kind of OCPs, the highest OCP pollution level in Karun River were seen from August to November 2009 ranging 71.43 – 89.34 µg/L, and the lowest were seen from Dec 2010 to March 2011 at levels of 22.25 - 22.64 µg/L. The highest and lowest mean concentrations of 12 investigated pesticides were ß-Endosulfan and pp' DDT with 28.51and 0.01 µg/L respectively.Conclusions: Comparison of total organochlorine pesticides residues concentration with WHO guidelines revealed that the Karun River had total OCPs residues above the probable effect level (0.2-20 µg/L, P < 0.05, which could pose a risk to aquatic life.

  14. Study on convective mixing phenomena in parallel triple-jet along wall. Comparison of temperature fluctuation characteristics between sodium and water

    International Nuclear Information System (INIS)

    Full text of publication follows: When temperature fluctuation due to convective mixing between hot and cold fluids is transferred to structure, there is a possibility of high cycle thermal fatigue. In a fast reactor sodium is used as coolant. Many experiments and calculations using water as working fluid have been carried out for the temperature fluctuations. As regarding sodium there are few experimental data. Sodium has approximately a 100 times larger thermal conductivity than water though dynamic viscosity is the same order. So temperature fluctuation characteristics in sodium will be different from that in water. Especially, decay characteristics of temperature fluctuation near a wall surface are strongly influenced by thermal property of fluid in a boundary layer. This is of importance to evaluate transfer characteristics of temperature fluctuation from fluid to structure. Here, sodium and water experiments were performed using the same geometry of the test sections. These experimental apparatuses have parallel triple jets sandwiched with two partition plates. The triple jets flow vertically along a wall with convective mixing among the jets. The jet in the center is cold, and two jets in both sides are hot. The discharged velocities of the triple jets were 0.5 m/s in both experiments. The temperature data were obtained by movable thermocouple trees, which consisted of 25 to 40 thermocouples. The temperatures were measured at 0.5 mm from the wall surface to the center position between the two partition plates. In addition, a particle image velocimetry was applied to the water experiment. As for the time-averaged temperature field at the furthest position from the wall, the hot jets were inclined toward the cold jet in both experiments. Temperature fluctuation intensity was high in the region where the cold jet met the hot jets. A prominent frequency was observed in temperature fluctuation where the cold jet contacted the hot jets; it was resulted from oscillation of the jets. Both sodium and water experiments showed the same tendency of frequency characteristics at the furthest position from the wall surface, and the prominent frequency in sodium was the same as that in water. Temperature fluctuation intensity in sodium is small at the neighborhood of the wall surface in comparison with that at the furthest position from the wall. In water case, on the other hand, temperature fluctuation intensity near the wall was slightly larger than that at the furthest position from the wall. In sodium, the power spectrum density (PSD) near the wall was close to the PSD at the furthest position from the wall. In water, however, the prominent frequency diminished in the PSD near the wall. The vanished frequency component was shifted to the lower frequency components. The space distributions and frequency characteristics of temperature fluctuations were obtained and differences were discussed with fluid property in sodium and water experiments. (authors)

  15. Characterisation of Culex quinquefasciatus (Diptera: Culicidae larval habitats at ground level and temporal fluctuations of larval abundance in Córdoba, Argentina

    Directory of Open Access Journals (Sweden)

    Marta Grech

    2013-09-01

    Full Text Available The aims of this study were to characterise the ground-level larval habitats of the mosquito Culex quinquefasciatus, to determine the relationships between habitat characteristics and larval abundance and to examine seasonal larval-stage variations in Córdoba city. Every two weeks for two years, 15 larval habitats (natural and artificial water bodies, including shallow wells, drains, retention ponds, canals and ditches were visited and sampled for larval mosquitoes. Data regarding the water depth, temperature and pH, permanence, the presence of aquatic vegetation and the density of collected mosquito larvae were recorded. Data on the average air temperatures and accumulated precipitation during the 15 days prior to each sampling date were also obtained. Cx. quinquefasciatus larvae were collected throughout the study period and were generally most abundant in the summer season. Generalised linear mixed models indicated the average air temperature and presence of dicotyledonous aquatic vegetation as variables that served as important predictors of larval densities. Additionally, permanent breeding sites supported high larval densities. In Córdoba city and possibly in other highly populated cities at the same latitude with the same environmental conditions, control programs should focus on permanent larval habitats with aquatic vegetation during the early spring, when the Cx. quinquefasciatus population begins to increase.

  16. Characterisation of Culex quinquefasciatus (Diptera: Culicidae) larval habitats at ground level and temporal fluctuations of larval abundance in Córdoba, Argentina

    Scientific Electronic Library Online (English)

    Marta, Grech; Paolo, Sartor; Elizabet, Estallo; Francisco, Luduena-Almeida; Walter, Almiron.

    2013-09-01

    Full Text Available The aims of this study were to characterise the ground-level larval habitats of the mosquito Culex quinquefasciatus, to determine the relationships between habitat characteristics and larval abundance and to examine seasonal larval-stage variations in Córdoba city. Every two weeks for two years, 15 [...] larval habitats (natural and artificial water bodies, including shallow wells, drains, retention ponds, canals and ditches) were visited and sampled for larval mosquitoes. Data regarding the water depth, temperature and pH, permanence, the presence of aquatic vegetation and the density of collected mosquito larvae were recorded. Data on the average air temperatures and accumulated precipitation during the 15 days prior to each sampling date were also obtained. Cx. quinquefasciatus larvae were collected throughout the study period and were generally most abundant in the summer season. Generalised linear mixed models indicated the average air temperature and presence of dicotyledonous aquatic vegetation as variables that served as important predictors of larval densities. Additionally, permanent breeding sites supported high larval densities. In Córdoba city and possibly in other highly populated cities at the same latitude with the same environmental conditions, control programs should focus on permanent larval habitats with aquatic vegetation during the early spring, when the Cx. quinquefasciatus population begins to increase.

  17. On the interpretation of coastal aquifer water level trends and water balances: A precautionary note

    Science.gov (United States)

    Morgan, L.; Werner, A. D.; Simmons, C.

    2012-12-01

    It is common for seawater intrusion-induced interface movements and associated changes in seawater volume not to be considered in coastal aquifer management studies. However, it is not well understood when this simplified approach may result in erroneous estimates of freshwater volumes and flawed interpretations of water level trend analyses. This gap is addressed in this study using a simple steady-state, sharp-interface, analytic modelling approach (i.e., Strack, 1976) to generate idealised relationships between seawater volume, freshwater volume and water levels. For a number of case studies, water level trends were found to be increasingly insensitive to reductions in freshwater volume and, as such, changes in seawater volume need to be considered when using water level trends as a measure of sustainability (e.g., within trigger-level management approaches, as commonly applied in Australia). The conditions under which seawater volume changes have greatest impact on water level trends are also described. Changes in seawater volume (over an assumed timescale) were found to represent 10% to 30% of freshwater discharge under realistic water table decline scenarios. As such, it is shown that changes in seawater volume need to be included within water balance assessments for the case studies considered. These results have wide-sweeping implications for coastal aquifer management, demonstrating that seawater volume changes may, in many cases, need to be included to avoid over-allocation of groundwater. In view of the short-comings associated with using water level trends to assess coastal aquifer status, an approach involving the comparison of groundwater levels relative to the hydraulic head imposed by the ocean, accounting for density effects, is recommended. A representative head for the coastal boundary in freshwater-only representations of unconfined aquifers is proposed that produces reasonable fluxes of freshwater discharge to the sea. This new coastal head adds to the Post et al. (2007) discussion of freshwater head calculations. It provides a first-order estimate of the value that near-shoreline watertable levels should exceed to maintain a discharge to the sea and to avoid SWI issues. The analytic solution used for this study involves an assumption of quasi-equilibrium conditions between the water table and interface. This assumption was evaluated using a selection of transient simulations and was found to be a reasonable approximation in the majority of case studies. As such, the analytic methods presented here can, in many cases, be rapidly applied to assess the need to consider seawater volumes within specific cases. References Post, V., Kooi, H., Simmons, C., 2007. Using hydraulic head measurements in variable-density ground water flow analyses. Ground Water 45(6), 664-671. Strack, O.D.L., 1976. Single-potential solution for regional interface problems in coastal aquifers. Water Resources Research 12, 1165-1174.

  18. Estimation of the influence of level fluctuations of the Caspian Sea on navigation and development of activities on the improvement of the condition of the infrastructure of waterways in the delta of the Astrakhan region

    Directory of Open Access Journals (Sweden)

    Karasaeva Al’finur Ravil’evna

    2010-10-01

    Full Text Available According experts’ forecasts, the fall of the level of the Caspian Sea, which has been recently stabilized on the mark – minus 26.5 m. on the coast of the Russian Federation, is expected. The modern condition of waterways of the Astrakhan region is considered due to the fact that navigation belongs to basic branches of the national economy, depending on fluctuations of the sea level. It is noticed that many objects of the infrastructure of the Astrakhan region, such as industrial enterprises, agricultural and fishing organizations, and ports, including the port Olya, are situated in so-called "coastal zone of risk". It is offered to apply bank protection of half-slope type as means to protect the given territo-ries from the influence of waters of the Caspian Sea. It is a levee, which frontal slope is strengthened by precast concrete slabs.

  19. Differential equations governing slip-induced pore-pressure fluctuations in a water-saturated granular medium

    Science.gov (United States)

    Iverson, R.M.

    1993-01-01

    Macroscopic frictional slip in water-saturated granular media occurs commonly during landsliding, surface faulting, and intense bedload transport. A mathematical model of dynamic pore-pressure fluctuations that accompany and influence such sliding is derived here by both inductive and deductive methods. The inductive derivation shows how the governing differential equations represent the physics of the steadily sliding array of cylindrical fiberglass rods investigated experimentally by Iverson and LaHusen (1989). The deductive derivation shows how the same equations result from a novel application of Biot's (1956) dynamic mixture theory to macroscopic deformation. The model consists of two linear differential equations and five initial and boundary conditions that govern solid displacements and pore-water pressures. Solid displacements and water pressures are strongly coupled, in part through a boundary condition that ensures mass conservation during irreversible pore deformation that occurs along the bumpy slip surface. Feedback between this deformation and the pore-pressure field may yield complex system responses. The dual derivations of the model help explicate key assumptions. For example, the model requires that the dimensionless parameter B, defined here through normalization of Biot's equations, is much larger than one. This indicates that solid-fluid coupling forces are dominated by viscous rather than inertial effects. A tabulation of physical and kinematic variables for the rod-array experiments of Iverson and LaHusen and for various geologic phenomena shows that the model assumptions commonly are satisfied. A subsequent paper will describe model tests against experimental data. ?? 1993 International Association for Mathematical Geology.

  20. Establishing solar water disinfection as a water treatment method at household level

    Directory of Open Access Journals (Sweden)

    Regula Meierhofer

    2006-12-01

    Full Text Available 1.1 billion People worldwide do not have access to safe drinking water and therefore are exposed to a high risk for diarrhoeal diseases. As a consequence, about 6,000 children die each day of dehydration due to diarrhoea. Adequate water treatment methods and safe storage of drinking water, combined with hygiene promotion, are required to prevent the population without access to safe drinking water from illness and death. Solar water disinfection (SODIS is a new water treatment to be applied at household level with a great potential to reduce diarrhoea incidence of users. The method is very simple and the only resources required for its application are transparent PET plastic bottles (or glass bottles and sufficient sunlight: microbiologically contaminated water is filled into the bottles and exposed to the full sunlight for 6 hours. During solar exposure, the diarrhoea causing pathogens are killed by the UV-A radiation of the sunlight. At present, SODIS is used by about 2 Million users in more than 20 countries of the South. Diarrhoea incidence of users significantly has been reduced by 30 to 70 %. A careful and long-term community education process that involves creating awareness on the importance of treating drinking water and initiates behaviour change is required to establish the sustainable practice of SODIS at community level. In Madagascar, more than 160 children younger than 5 years die each day from malaria, diarrhoea and acute respiratory illnesses. The application of household water treatment methods such as SODIS significantly could contribute to improve their health.

  1. Time-averaged serum potassium levels and its fluctuation associate with 5-year survival of peritoneal dialysis patients: two-center based study

    Science.gov (United States)

    Li, Shen-Heng; Xie, Jian-Teng; Long, Hai-Bo; Zhang, Jun; Zhou, Wei-Dong; Niu, Hong-Xin; Tang, Xun; Feng, Zhong-Lin; Ye, Zhi-Ming; Zuo, Yang-Yang; Fu, Lei; Wen, Feng; Wang, Li-Ping; Wang, Wen-Jian; Shi, Wei

    2015-01-01

    The time-averaged serum potassium was more comprehensive to reflect the all-time changes of serum potassium levels during peritoneal dialysis (PD). However, the association of fluctuation of time-averaged serum potassium level with long-time survival of PD patients remains unknown. In this retrospective study, we included 357 incident PD patients in 2 centers from January 1, 2007 to October 31, 2012 with follow-up through October 31, 2014. Our data demonstrated that it was the lower time-averaged serum potassium level rather than baseline of serum potassium level that was associated with high risk of death. Patients with higher standard deviation (SD) had significantly poorer all-cause (p?=?0.016) and cardiovascular mortality (p?=?0.041). Among the patients with time-averaged serum potassium levels below 4.0 mEq/L, a lower mean value was more important than its SD to predict death risk. In contrast, the patients with time-averaged serum potassium levels above 4.0?mEq/L, those with serum potassium SD?fluctuation contributed disproportionately to the high death risk in PD patients. PMID:26507157

  2. The carbonate—clastic cycles of the East-Alpine Raibl group: Result of third-order sea-level fluctuations in the Carnian

    Science.gov (United States)

    Bechstädt, T.; Schweizer, T.

    1991-03-01

    The Carnian Raibl group of the Eastern Alps consists of three 50-100 m thick, alternating carbonate and clastic third-order cycles, each of which can be traced for hundreds of kilometers. Tectono-eustatic sea-level fluctuations of a few tens of metres, spanning a few millions of years, are the driving mechanism of this cyclicity. The carbonate intervals represent restricted marginal marine, tidal and evaporitic environments. The clastic intervals represent inner and outer shelf facies, and are related to the fluviatile "Schilfsandstein" of the Germanic facies belt. In the Raibl group, contrary to other carbonate/clastic depositional settings, relative sea-level lowstands are dominated by carbonate production, and highstands are dominated by clastic deposition. Each of the three Raibl cycles corresponds to a type-2 sequence, containing shelf margin, transgressive and highstand systems tracts. During sea-level lowstands, deltaic point sources were near the shelf margin, allowing clastics to bypass the carbonate platform. This setting corresponds to a shelf margin systems tract. Transgressive and highstand systems tracts developed during the subsequent sea-level rise, as deltaic clastics were reworked and redistributed over the carbonate platform, and the deltas retrograded to the inner shelf. The highstand systems tracts are capped by a type 2 sequence boundary, which is conformable in the study area. The systems tracts can be further subdivided into shallowing upward subcycles, caused by fourth-order sea-level fluctuations, believed to represent Milankovitch rhythms. The middle Raibl cycle is consistently thinner, and may represent a shorter termed, third-order sea-level fluctuation. Our data also corroborate a second-order transgressive trend for the Carnian.

  3. Short-term water level forecasts for the Laurentian Great Lakes using coupled atmosphere, land-surface and lake models

    Science.gov (United States)

    Fortin, Vincent; Mackay, Murray; Casas-Prat, Mercè; Seglenieks, Frank; Dyck, Sarah; Dupont, Frédéric; Roy, François; Smith, Gregory C.

    2015-04-01

    Over the Gulf of St. Lawrence, Environment Canada operates a very successful short-term (48-h) environmental prediction system which includes the GEM atmospheric model, the ISBA land-surface model and the NEMO-CICE ice-ocean model. The positive impact of two-way coupling between the atmosphere and ocean is most clearly seen in winter, due to the presence of a dynamic ice cover and large heat fluxes over the ocean. This system is now being tested over the Laurentian Great Lakes, with the same objective of improving forecasts both for the atmosphere and the water bodies. In order to account for the significant impact of streamflow on the water level and water temperature of the Great Lakes, routing models for river flow and for connecting channels between lakes were added to the system. Offline tests demonstrated the capacity of the system to accurately simulate seasonal and multi-annual fluctuations in water levels and ice cover, as well as the need for consistent heat flux calculations in the atmospheric and ocean models. In this presentation, we focus on the skill of short-term water level forecasts. Over a few days, water levels of the Great Lakes mainly respond to the wind stress, but also change with surface pressure, precipitation, evaporation and river flow. The approach taken to account for each of these factors is described, and the skill of the resulting water level forecast is assessed over the fall of 2014 and the winter of 2015. It is shown that the system can accurately predict storm surges and seiches at the hourly time scale, with a skill that decreases slowly over 48-h, suggesting that skillful forecasts with longer lead times are feasible. A plan for increasing the lead time up to one month is presented.

  4. Evaluation of boiling water reactor water-level sensing line break and single failure: Generic Issue 101 boiling water reactor level redundancy - technical findings

    International Nuclear Information System (INIS)

    This report presents an evaluation of the potential safety concerns identified in Generic Issue 101, related to Boiling Water Reactor (BWR) level sensing line breaks. For this review, failure combinations and transients were evaluated to assure that existing BWR plants could be safely shut down under postulated conditions of a break or leak in the instrument line of the reactor vessel level instrumentation plus an independent single failure in any protection system. The review evaluated all the designs currently employed in boiling water reactor plants. Part I of this report describes the methodology used to evaluate the various designs and provides technical findings. Part II presents the value/impact analysis performed to evaluate the various alternatives that were considered to improve plant response to a postulated water-level sensing line break and single failure

  5. CFNN based water level control for nuclear steam generator

    International Nuclear Information System (INIS)

    Because normal PID controller can't change its parameters according to the change of control object parameters. In this paper, the compensatory fuzzy neural network (CFNN) was used with a simplified model of nuclear steam generator (NSG) to design a NSG water level controller. Compensatory neurons which were introduced in the CFNN will make the control system improve the quality of fault tolerant and more stable. Meanwhile compensative fuzzy computation is optimized dynamically in the study algorithm of neural network, therefore the network is much more adaptive and the training speed is much faster. The results of simulation show that under this control method the system has smaller maximum overshoot and faster convergence speed than that of under normal PID control method. The CFNN can not only adjust parameters properly on line, but also can optimized relevant fuzzy reasoning in dynamic way, so it suit to be used on ling learning and control. The control method used in this paper is meaningful to the research of NSG water level intelligent control. (authors)

  6. Roughness and discharge uncertainty propagation in water level calculations :

    Science.gov (United States)

    Goutal, Nicole; Arnaud, Aurelie; Goeury, Cedric; Ata, Riadh

    2015-04-01

    In hydraulics, water level simulations are necessary for variety of purposes, such as flood, hydraulic structures design etc. Knowledge of the uncertainty in flow depth estimation is crucial for risk assessment and hydraulic structures design. In hydraulics models, the sources of uncertainty are manifold : roughness coefficient, boundary conditions (discharge - geometry - data for calibration etc) . In the present study, we will investigate the effect of two key uncertainty sources on water level simulations in 1D - 2D hydraulic models : the roughness coefficient and the discharge quantile, i.e. the flow rate corresponding to a given return period. A Monte-Carlo method is used to propagate the input uncertainty through the model in case of a real case study on a 50 km reach of the Garonne river. The difficulty with the crude Monte-Carlo method is due to the convergence, for instance the approximation of quantile could be time consuming. It will be illustrated on a real case of river that we propose for a benchmark.

  7. Level of Water Awareness at Some Jordanian Universities Studentâ??s

    OpenAIRE

    Mohamad Said Damanhouri; Bashar Abdallah Al-Saleem; Yousra Yousef AL-Ali

    2012-01-01

    Problem statement: Jordan has been facing shortage in water sector during the last three decades due to natural and society factors, weakness of water awareness is one of these Society factors, so this study focused on the level of water awareness in fields of; water significant in life, water problem in Jordan, water conservation at part of Jordanian society. Approach: The study aimed to Investigate how some Jordanian Universities students behave to identify the level of water awareness in s...

  8. Salmon Migration Patterns Revealed the Temporal and Spatial Fluctuations of the Radiocesium Levels in Terrestrial and Ocean Environments

    OpenAIRE

    Arai, Takaomi

    2014-01-01

    The disabling of the Fukushima Daiichi Nuclear Power Plant (F1NPP) resulted in the release of radionuclides, including 134Cs and 137Cs, into the air and the ocean. The unpredicted nuclear accident is of global concern for human health and the ecosystem. Although investigations of radionuclides in environments were performed shortly after the accident started, the temporal and spatial impacts and fluctuations on the releasing radionuclides to natural environment remain unclear. I focused on sa...

  9. Stable carbon and oxygen isotopes reveal Sahel drought events and ground water fluctuations in sub-Saharan Africa

    Science.gov (United States)

    Gebrekirstos, Aster

    2014-05-01

    Tree rings are important proxies for paleoclimate studies because they contain continuous historical records of inter-annual and intra-annual time resolutions, which range over hundreds of years. This study uses stable carbon and oxygen isotopes in tree rings to understand the drivers and impacts of climate change in sub-Saharan Africa and their ability to reconstruct past regional climate variability and climatic trends. Our approach considers large scale climate gradients and different temporal scales (inter-annual and intra-annual variations) and combines multi- parameter measurements (carbon and oxygen isotopes, whole wood and cellulose measurements). The study species are Faidherbia albida and Sclerocarya birrea from south and West Africa, respectively. Both are very important deciduous trees, and widely distributed in sub-Saharan Africa. Particularly, F. albida has a distinctive phenology; it bears leaves and flowers during the dry season and sheds its leaves during the rainy season. Stable carbon (?13C) and oxygen (?18O) mean values showed similar inter annual patterns. In general, both ?13C and ?18O show negative correlations with rainfall, humidity and PDSI. On the contrary, they are positively correlated with sunshine hours, maximum temperature and evaporation. The reverse phenology of Faidherbia and intra seasonal resolution measurements reveals seasonal ground water fluctuations. Both carbon and oxygen stable isotopes showed strong climatic signals including the long Sahel drought events and climatic recovery phases.

  10. Water levels in periodically measured wells in the Yucca Mountain Area, Nevada, 1988

    International Nuclear Information System (INIS)

    This report presents water-level data for 10 wells that were periodically measured in 1988 in the Yucca Mountain Area, Nevada. Water levels measured during 1987 are included in the report for reference. The report includes discussions of the methods used and corrections applied to obtain water-level depths and altitudes from onsite measurements. Water levels for each well are presented in tabular and graphical (hydrograph) form. The altitude of the water level in the upper part of the saturated zone is about 775 meters above sea level to the west of and along part of the crest of Yucca Mountain; along the eastern edge and southern end of Yucca Mountain, the water level is 728 to 730 meters above sea level. The water-level data were obtained to help evaluate the suitability of the area for storing high-level nuclear waste. 14 refs., 2 figs., 2 tabs

  11. Fluctuating water table affects gross ecosystem production and gross radiation use efficiency in a sedge-grass marsh.

    Czech Academy of Sciences Publication Activity Database

    Dušek, Ji?í; ?ížková, Hana; Stellner, Stanislav; Czerný, Radek; Kv?t, Jan

    2012-01-01

    Ro?. 692, ?. 1 (2012), s. 57-66. ISSN 0018-8158 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073; GA MŽP(CZ) SP/2D1/93/07; GA MŠk OC08021 Institutional research plan: CEZ:AV0Z60870520 Keywords : Wetland * fen * carbon * water level * Carex acuta L. * Eddy covariance Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.985, year: 2012

  12. Dynamic factor modeling of ground and surface water levels in an agricultural area adjacent to Everglades National Park

    Science.gov (United States)

    Ritter, A.; Muñoz-Carpena, R.

    2006-02-01

    The extensive eastern boundary of Everglades National Park (ENP) in south Florida (USA) is subject to one the most expensive and ambitious environmental restoration projects in history. Understanding and predicting the interaction between the shallow aquifer and surface water is a key component for fine-tuning the process. The Frog Pond is an intensively instrumented agricultural 2023 ha area adjacent to ENP. The interactions among 21 multivariate daily time series (ground and surface water elevations, rainfall and evapotranspiration) available from this area were studied by means of dynamic factor analysis, a novel technique in the field of hydrology. This method is designed to determine latent or background effects governing variability or fluctuations in non-stationary time series. Water levels in 16 wells and two drainage ditch locations inside the area were selected as response variables, and canal levels and net recharge as explanatory variables. Elevations in the two canals delimiting the Frog Pond area were found to be the main factors explaining the response variables. This influence of canal elevations on water levels inside the area was complementary and inversely related to the distance between the observation point and each canal. Rainfall events do not affect daily water levels significantly but are responsible for instantaneous or localized groundwater responses that in some cases can be directly associated with the risk of flooding. This close coupling between surface and groundwater levels, that corroborates that found by other authors using different methods, could hinder on-going environmental restoration efforts in the area by bypassing the function of wetlands and other surface features. An empirical model with a reduced set of parameters was successfully developed and validated in the area by interpolating the results from the dynamic factor analysis across the spatial domain (coefficient of efficiency across the domain: 0.66-0.99). Although specific to the area, the resulting model is deemed useful for water management within the wide range of conditions similar to those present during the experimental period.

  13. Non Invasive Water Level Monitoring on Boiling Water Reactors Using Internal Gamma Radiation: Application of Soft Computing Methods

    International Nuclear Information System (INIS)

    To provide best knowledge about safety-related water level values in boiling water reactors (BWR) is essentially for operational regime. For the water level determination hydrostatic level measurement systems are almost exclusively applied, because they stand the test over many decades in conventional and nuclear power plants (NPP). Due to the steam generation especially in BWR a specific phenomenon occurs which leads to a water-steam mixture level in the reactor annular space and reactor plenum. The mixture level is a high transient non-measurable value concerning the hydrostatic water level measuring system and it significantly differs from the measured collapsed water level. In particular, during operational and accidental transient processes like fast negative pressure transients, the monitoring of these water levels is very important. In addition to the hydrostatic water level measurement system a diverse water level measurement system for BWR should be used. A real physical diversity is given by gamma radiation distribution inside and outside the reactor pressure vessel correlating with the water level. The vertical gamma radiation distribution depends on the water level, but it is also a function of the neutron flux and the coolant recirculation pump speed. For the water level monitoring, special algorithms are required. An analytical determination of the gamma radiation distribution outside the reactor pressure vessel is impossible due to the multitude of radiation of physical processes, complicated non-stationary radiation source distribution and complex geometry of fixtures. For creating suited algorithms Soft Computing methods (Fuzzy Sets Theory, Artificial Neural Networks, etc.) will be used. Therefore, a database containing input values (gamma radiation distribution) and output values (water levels) had to be built. Here, the database was established by experiments (data from BWR and from a test setup) and simulation with the authorised thermo-fluid code ATHLET. (authors)

  14. Surface water considerations for low-level radioactive waste site

    International Nuclear Information System (INIS)

    To ensure that the objective of isolation of low-level radioactive wastes and stability of the disposal site after closure can be achieved, the surface hydrology of the potential sit must be carefully characterized prior to engineering and operation. At a site the most important considerations with regard to flooding, infiltration, erosion, and pathway of radionuclides are addressed as they relate to streams, ponds, hydraulic structures, and surface water users. To satisfactorily characterize the site, the type and amount of data and analyses needed for license applications and the environmental report are discussed. The discussion also includes potential sources of available data, the field data collection program that may be necessary, and methodologies that can be used for analysis

  15. Subtidal variability in water levels inside a subtropical estuary

    Science.gov (United States)

    Henrie, Krista; Valle-Levinson, Arnoldo

    2014-11-01

    Year-long time series of water level are analyzed at five locations along the St. Johns River Estuary, Florida, to investigate propagation of subtidal pulses. Hilbert-transformed Empirical Orthogonal Functions (HEOFs) are obtained after a dominant seasonal signal is extracted from the data. These functions provide information on spatial structure and propagation phase of subtidal water level pulses. The first HEOF mode explains 96% of the subtidal variability and features an unusual spatial structure: amplitude attenuation (averaging 1 mm/km) to 55 km upstream, slight amplification (0.16 mm/km) over the middle 70 km, and attenuation (2.3 mm/km) over the final 18 km of the estuary. The phase suggests a shift from progressive to quasi-standing wave behavior at 55 km from the estuary mouth. Additionally, local minima in the phase suggest two sources of subtidal forcing: the coastal ocean and the upstream end. An analytical model describing the evolution of long waves through a channel with frictional damping is fit to the amplitude of HEOF mode 1. Solutions are obtained as a function of two parameters: the nondimensional length of the basin, ?, and the nondimensional frictional depth, ?. Values of ? between 0.55 and 0.67 and ? between 1.45 and 1.7 provide the best fit with the HEOF results (1% error or less). These values indicate a highly frictional environment in which the average subtidal wavelength is 10 times the basin length. Subtidal pulses in this estuary, therefore, behave as damped waves that can be represented with idealized models.

  16. Water level measuring method in pipelines of steam generator

    International Nuclear Information System (INIS)

    The device of the present invention can accurately and continuously monitor the water level of pipelines on high temperature side (hot legs) of a steam generator upon periodical inspection of a PWR type reactor. Namely, a supersonic wave sensor is disposed on the lower surface of the laterally disposed pipelines such as hot legs, and supersonic waves generated upwardly are reflected to the water surface in the pipeline and received. Then, the time difference between sending and reception is measured by a measuring device. In order to prevent degradation at high temperature and radiation damages of the supersonic wave sensor, the device is structured such that the supersonic sensor is attached and detached easily to and from the pipeline upon start and completion of the periodical inspection. Since the present invention does not require scraping or welding fabrication of pipeline, it can be disposed extremely easily compared with a conventional visual observation method by using a perspective-type small tube or a method by using coolant pressure difference. (I.S.)

  17. GPS water level measurements for Indonesia's Tsunami Early Warning System

    Directory of Open Access Journals (Sweden)

    T. Schöne

    2011-03-01

    Full Text Available On Boxing Day 2004, a severe tsunami was generated by a strong earthquake in Northern Sumatra causing a large number of casualties. At this time, neither an offshore buoy network was in place to measure tsunami waves, nor a system to disseminate tsunami warnings to local governmental entities. Since then, buoys have been developed by Indonesia and Germany, complemented by NOAA's Deep-ocean Assessment and Reporting of Tsunamis (DART buoys, and have been moored offshore Sumatra and Java. The suite of sensors for offshore tsunami detection in Indonesia has been advanced by adding GPS technology for water level measurements.

    The usage of GPS buoys in tsunami warning systems is a relatively new approach. The concept of the German Indonesian Tsunami Early Warning System (GITEWS (Rudloff et al., 2009 combines GPS technology and ocean bottom pressure (OBP measurements. Especially for near-field installations where the seismic noise may deteriorate the OBP data, GPS-derived sea level heights provide additional information.

    The GPS buoy technology is precise enough to detect medium to large tsunamis of amplitudes larger than 10 cm. The analysis presented here suggests that for about 68% of the time, tsunamis larger than 5 cm may be detectable.

  18. A near-uniform fluctuation of ocean bottom pressure and sea level across the deep ocean basins of the Arctic Ocean and the Nordic Seas

    Science.gov (United States)

    Fukumori, Ichiro; Wang, Ou; Llovel, William; Fenty, Ian; Forget, Gael

    2015-05-01

    Across the Arctic Ocean and the Nordic Seas, a basin-wide mode of ocean bottom pressure and sea level fluctuation is identified using satellite and in situ observations in conjunction with a global ocean circulation model and its adjoint. The variation extends across the interconnected deep ocean basins of these semi-enclosed Arctic seas, collectively called the Arctic Mediterranean, with spatially near-uniform amplitude and phase. The basin-wide fluctuation is barotropic and dominates the region's large-scale variability from sub-monthly to interannual timescales. The fluctuation results from bifurcating coastally trapped waves generated by winds along the continental slopes of the Arctic Mediterranean and its neighboring seas, including the North Atlantic Ocean. The winds drive Ekman transport across the large bathymetric gradients, forcing mass divergence between the shallow coastal area and the deep ocean basins and creating ocean bottom pressure anomalies of opposite signs in the two regions. The anomalies rapidly propagate away as barotropic coastally trapped waves with the coast and continental slope as respective boundaries. The waves subsequently bifurcate at the shallow straits connecting the Arctic Mediterranean with the rest of the globe. The straits transmit the shallow anomalies but not the deep variations, thereby inhibiting the anomalies' mutual cancelation by geographically separating the two. Anomalies that enter the deep Arctic basins equilibrate uniformly across the domain characterized by a homogeneous depth-integrated planetary potential vorticity distribution. The potential vorticity's steep gradient that borders the basins shields the region from neighboring shallow variations, giving rise to the observed spatially confined fluctuation. Compensating anomalies outside the Arctic adjust similarly across the rest of the globe but are comparatively negligible in amplitude because of the global ocean's larger area relative to that of the deep Arctic Mediterranean. The study, from a technical perspective, illustrates the utility of a model's adjoint in identifying causal mechanisms underlying a complex system.

  19. Water levels in wells J-11 and J-12, 1989-91, Yucca Mountain Area, Nevada

    International Nuclear Information System (INIS)

    Water levels have been measured in the Yucca Mountain area, Nevada, since 1981 in order to gain a better understanding of the ground-water flow system in the area. Water levels in wells J-11 and J-12 have been periodically measured using calibrated reeled steel tapes since 1989, however, calculation of water-level altitude was not possible prior to 1993 due to missing reference elevations. These elevations were determined in 1993 by the U.S. Geological Survey. During 1989-91, water-level altitudes for well J-11 ranged from 732.09 to 732.40 meters and the mean water-level altitude was 732.19 meters. During 1989-91, water-level altitudes for well J-12 ranged from 727.84 to 728.03 meters, and the mean water-level altitude was 727.95 meters

  20. Effects of alternative Missouri River management plans on ground-water levels in the lower Missouri River flood plain

    Science.gov (United States)

    Kelly, Brian P.

    2000-01-01

    In 1998, the U.S. Army Corps of Engineers (USACE) proposed eight Alternative River Management Plans (ARMPs) for managing reservoir levels and water-release rates for the Missouri River. The plans include the Current Water Control Plan (CWCP), Conservation 18, 31, and 44 (C18, C31, and C44) that provide different levels of water conservation in the reservoirs during droughts, Fish and Wildlife 10, 15, and 20 (FW10, FW15, and FW20) that vary water-release rates to provide additional fish and wildlife benefits, and Mississippi River 66 (M66) that maintains a 66,000 cubic feet per second discharge at St. Louis to provide navigation support for the Mississippi River. Releases from Gavin?s Point Dam affect both the lower 1,305 kilometers of the Missouri River and ground-water levels in the lower Missouri River flood plain. Changes in the magnitude and timing of ground-water-level fluctuations in response to changes in river management could impact agriculture, urban development, and wetland hydrology along the lower Missouri River flood plain. This study compared simulated ground-water altitude and depth to ground water for the CWCP in the Missouri River alluvial aquifer near the Kansas City area between 1970 and 1980 with each ARMP, determined the average change in simulated ground-water level for selected river-stage flood pulses at selected distances from the river, and compared simulated flood pulse, ground-water responses with actual flood pulse, and ground-water responses measured in wells located at three sites along the lower Missouri River flood plain.For the model area, the percent total shallow ground-water area (depth to ground water less than 0.3048 meter) is similar for each ARMP because of overall similarities in river flow between ARMPs. The percent total shallow ground-water area for C18 is the most similar to CWCP followed by C31, M66, C44, FW10, FW15, and FW20. ARMPs C18, C31, C44, and M66 do not cause large changes in the percent shallow ground-water area when compared to CWCP. FW10 and FW15 each cause a spring increase and a summer decrease in the shallow ground-water area. FW20 has a larger spring increase in the shallow ground-water area, but the largest decrease is delayed into November. Analysis of daily changes between the ARMPs indicate large differences can exist in both duration and extent of shallow ground-water areas.A series of 12 flood pulses of 0.5-, 1-, and 3-meters in magnitude and 1-, 8-, 32-, and 128-days in duration were simulated using the ground-water flow model. A ground-water response factor (GWRF, defined as the change in ground-water level at a known distance from the river, at a specified time after the beginning of a flood pulse divided by the magnitude of the flood pulse) was determined daily for selected distances from the river. The GWRF multiplied by the magnitude of the flood pulse can be used to estimate the change in ground-water level at a known time after the beginning of a flood pulse for a known distance from the river. Flood-pulse simulation results indicate the relatively small impact on ground-water levels of small river-stage fluctuations of short duration as might occur daily or weekly. The larger impact on ground-water levels from larger river-stage increases of longer duration indicate the importance of river management flow releases, seasonal changes in river flow, and the effects of continuous high-river stage for long periods on ground-water levels of the lower Missouri River flood plain.A comparison of model results to well hydrographs from three areas along the lower Missouri River flood plain was used to determine how closely the simulated GWRFs matched the measured GWRFs for similar flood pulses and the transferability of GWRFs to other parts of the lower Missouri River flood plain. The comparison between the measured and simulated ground-water responses indicate that the simulated ground-water responses can provide a reasonable estimate of the ground-water resp

  1. Pretransitional behavior in a water-DDAB-5CB microemulsion close to the demixing transition. Evidence for intermicellar attraction mediated by paranematic fluctuations

    CERN Document Server

    Caggioni, M; Bellini, T; Clark, N A; Mantegazza, F; Maritan, A; Caggioni, Marco; Giacometti, Achille; Bellini, Tommaso; Clark, Noel A.; Mantegazza, Francesco; Maritan, Amos

    2005-01-01

    We present a study of a water-in-oil microemulsion in which surfactant coated water nanodroplets are dispersed in the isotropic phase of the thermotropic liquid crystal 5CB. As the temperature is lowered below the isotropic to nematic phase transition of pure 5CB, the system displays a demixing transition leading to a coexistence of a droplet rich isotropic phase with a droplet poor nematic. The transition is anticipated, in the high T side, by increasing pretransitional fluctuations in 5CB molecular orientation and in the nanodroplet concentration. The observed phase behavior supports the notion that the nanosized droplets, while large enough for their statistical behavior to be probed via light scattering, are also small enough to act as impurities, disturbing the local orientational ordering of the liquid crystal and thus experiencing pretransitional attractive interaction mediated by paranematic fluctuations. The pretransitional behavior, together with the topology of the phase diagram, can be understood ...

  2. Drinking cholera : Salinity levels and palatability of drinking water in coastal Bangladesh

    DEFF Research Database (Denmark)

    Grant, Stephen Lawrence; Tamason, Charlotte Crim

    2015-01-01

    Objectives: To measure the salinity levels of common water sources in coastal Bangladesh and explore perceptions of water palatability among the local population to investigate the plausibility of linking cholera outbreaks in Bangladesh with ingestion of saline-rich cholera-infected river water. Methods: Hundred participants took part in a taste-testing experiment of water with varying levels of salinity. Salinity measurements were taken of both drinking and non-drinking water sources. Informal group discussions were conducted to gain an in-depth understanding of water sources and water uses. Results: Salinity levels of non-drinking water sources suggest that the conditions for Vibrio cholerae survival exist 7-8 days within the local aquatic environment. However, 96% of participants in the taste-testing experiment reported that they would never drink water with salinity levels that would be conducive to V. cholerae survival. Furthermore, salinity levels of participant's drinking water sources were all well below the levels required for optimal survival of V. cholerae. Respondents explained that they preferred less salty and more aesthetically pleasing drinking water. Conclusion: Theoretically, V. cholerae can survive in the river systems in Bangladesh; however, water sources which have been contaminated with river water are avoided as potential drinking water sources. Furthermore, there are no physical connecting points between the river system and drinking water sources among the study population, indicating that the primary driver for cholera cases in Bangladesh is likely not through the contamination of saline-rich river water into drinking water sources.

  3. ERPWS: An Energy Efficient Routing Protocol for Conductive Sensor based Water Level Monitoring and Control System using Zigbee and 74HC14 Inverter

    Directory of Open Access Journals (Sweden)

    Saima Maqbool

    2013-07-01

    Full Text Available In this paper we have shown how to use conductive sensor, Zigbee and 74HC14 Inverter to monitor the water level and to control the working of pump. This project is designed to automatically fill the over head tank when it gets empty and monitor the water level in it. The motor is switched ON when the water level in the overhead tank drops below a pre fixed low level (on point and puts off the motor when water level rises up to pre fixed high level (off point.The motor is also switched off during the following conditions: when the sump water is exhausted before filling overhead tank, pump running dry, mains voltage fluctuations. We also introduce an energy efficient routing protocol for Wireless Sensor Networks (ERPWS for Conductive Sensor based Water Level Monitoring and Control System using Zigbee (XBEE 802.15.4 in terms of energy consumptions, the packet loss ratio, network lifetime and the average delivery delay. The XBEE used here is XBEE Pro Series 1(XBP24-AWI-001 and IC used is 74HC14 Hex Inverting Schmitt trigger. Simulation results have been obtained by using NS2 simulator. The evaluation results show that the energy consumption of routing using ERPWS is significantly lower than LEACH and traditional routing protocols.

  4. The nuclear physical method for high pressure steam manifold water level gauging and its error

    International Nuclear Information System (INIS)

    A new method, which is non-contact on measured water level, for measuring high pressure steam manifold water level with nuclear detection technique is introduced. This method overcomes the inherent drawback of previous water level gauges based on other principles. This method can realize full range real time monitoring on the continuous water level of high pressure steam manifold from the start to full load of boiler, and the actual value of water level can be obtained. The measuring errors were analysed on site. Errors from practical operation in Tianjin Junliangcheng Power Plant and in laboratory are also presented

  5. Behaviors of extreme water level in the Pearl River Delta and possible impacts from human activities

    Directory of Open Access Journals (Sweden)

    Y. D. Chen

    2007-12-01

    Full Text Available Trends and variations of the extreme water levels defined as exceeding/falling below certain thresholds (mean ± std across the Pearl River Delta (PRD are systematically explored using the linear regression method. Research results indicate that: 1 The upper PRD is dominated by the significant decreasing low water level, and significant increasing low water level can be identified in the lower PRD. The variations of the relative frequency of the high water level are characterized by the decreasing variability in the middle PRD. However more stations show significant changes of the relative frequency of the low water level across the PRD. No confirmative changing patterns of the relative frequency of the low water level can be detected in the middle PRD; 2 When it comes to the seasonal variations of the high/low water level in JJA (high flow periods in the PRD, stations located closer to the estuary tend to exhibit increasing high/low water level. However stations located closer to the upper PRD tend to show decreasing high/low water level. Similar patterns can be identified in the high/low water level in DJF (low flow periods in the PRD; 3 The changes of the water level in the PRD are heavily affected by human interferences, e.g. in-channel dredging, sand mining and the construction of levees. The stations dominated by decreasing water level are mostly located along the river channels featured by highly-intensive dredging. The stations along the coastal regions show significant increasing extreme high/low water level. The coastal regions are not influenced by in-channel dredging, and furthermore, sediment loads from upper and middle PRD are deposited in the river mouths and which will tend to raise the water level in the estuary of the PRD. The findings of this paper may be helpful for local water resource management.

  6. Salmon Migration Patterns Revealed the Temporal and Spatial Fluctuations of the Radiocesium Levels in Terrestrial and Ocean Environments

    Science.gov (United States)

    Arai, Takaomi

    2014-01-01

    The disabling of the Fukushima Daiichi Nuclear Power Plant (F1NPP) resulted in the release of radionuclides, including 134Cs and 137Cs, into the air and the ocean. The unpredicted nuclear accident is of global concern for human health and the ecosystem. Although investigations of radionuclides in environments were performed shortly after the accident started, the temporal and spatial impacts and fluctuations on the releasing radionuclides to natural environment remain unclear. I focused on salmon, which migrate from inland to the open ocean globally, to reveal the three-year (May 2011 to February 2014) fluctuations and accumulations of 134Cs and 137Cs from terrestrial to open ocean environments after the F1NPP accident. The 134Cs and 137Cs concentrations in six salmonids exhibited lower temporal variations for three years after the F1NPP accident, suggesting that these radionuclides are widely distributed and these radionuclides remain in the natural environment globally with less convergence. The accumulation patterns were significantly different among the different salmon species. Fluvial (freshwater residence) type salmons exhibited significantly higher accumulation in 134Cs (25.3–40.2 Bq kg?1 in mean) and 137Cs (41.4–51.7 Bq kg?1 in mean) than did the anadromous (sea-run) type salmons (0.64–8.03 Bq kg?1 in mean 134Cs and 0.42–10.2 Bq kg?1 in mean 137Cs) suggesting widespread contamination in terrestrial environments versus the coastal and open ocean environments. Salmonids are the most highly migratory animals and are characterised by their strong tendency to return home to their natal site for reproduction. Salmonids have a potential to be a good indicator as an effective monitoring animal. PMID:24964195

  7. Salmon migration patterns revealed the temporal and spatial fluctuations of the radiocesium levels in terrestrial and ocean environments.

    Science.gov (United States)

    Arai, Takaomi

    2014-01-01

    The disabling of the Fukushima Daiichi Nuclear Power Plant (F1NPP) resulted in the release of radionuclides, including 134Cs and 137Cs, into the air and the ocean. The unpredicted nuclear accident is of global concern for human health and the ecosystem. Although investigations of radionuclides in environments were performed shortly after the accident started, the temporal and spatial impacts and fluctuations on the releasing radionuclides to natural environment remain unclear. I focused on salmon, which migrate from inland to the open ocean globally, to reveal the three-year (May 2011 to February 2014) fluctuations and accumulations of 134Cs and 137Cs from terrestrial to open ocean environments after the F1NPP accident. The 134Cs and 137Cs concentrations in six salmonids exhibited lower temporal variations for three years after the F1NPP accident, suggesting that these radionuclides are widely distributed and these radionuclides remain in the natural environment globally with less convergence. The accumulation patterns were significantly different among the different salmon species. Fluvial (freshwater residence) type salmons exhibited significantly higher accumulation in 134Cs (25.3-40.2 Bq kg(-1) in mean) and 137Cs (41.4-51.7 Bq kg(-1) in mean) than did the anadromous (sea-run) type salmons (0.64-8.03 Bq kg(-1) in mean 134Cs and 0.42-10.2 Bq kg(-1) in mean 137Cs) suggesting widespread contamination in terrestrial environments versus the coastal and open ocean environments. Salmonids are the most highly migratory animals and are characterised by their strong tendency to return home to their natal site for reproduction. Salmonids have a potential to be a good indicator as an effective monitoring animal. PMID:24964195

  8. Fluctuating sea levels off Bombay (India) between 14,500 and 10,000 years before present

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.; Hashimi, N.H.; Menezes, E.T.; Wagh, A.B.

    of deposition shows that sea level had transgressed considerably prior to 10,000 years before present (super(14) C age of the surface sediment). By comparison with global events, we infer that the sea level was at 101.5 m below the present level at about 14...

  9. To save water or not? : A study of water scarcity at multiple levels, and people's attitudestowards it in Bangalore, India

    OpenAIRE

    Bognäs, Désirée

    2011-01-01

    In a situation where population growth and development is to be sustained throughnaturally limited water resources, something needs to be done to either render waterusage more effective or make more water available. This is the situation in Bangalore Urban District (BUD), an ever growing city lying far from perennial water sources. This thesis presents the water situation in BUD, and aims to analyze the current status of water resources on multiple levels in BUD. Further the aim is to look at...

  10. Analytical approach for determining the mean water level profile in an estuary with substantial fresh water discharge

    Science.gov (United States)

    Cai, H.; Savenije, H. H. G.; Jiang, C.; Zhao, L.; Yang, Q.

    2015-08-01

    Although modestly, the mean water level in estuaries rises in landward direction induced by a combination of the salinity gradient, the tidal asymmetry, and the backwater effect. The water level slope is increased by the fresh water discharge. However, the interactions between tide and river flow and their individual contributions to the rise of the mean water level along the estuary are not yet completely understood. In this study, we adopt an analytical approach to describe the tidal wave propagation under the influence of fresh water discharge, in which the friction term is approximated by a Chebyshev polynomials approach. The analytical model is used to quantify the contributions made by tide, river, and tide-river interaction to the water level slope along the estuary. Subsequently, the method is applied to the Yangtze estuary under a wide range of river discharge conditions and the influence of tidal amplitude and fresh water discharge on the longitudinal variation of mean water level is explored. The proposed method is particularly useful for accurately predicting water levels and the frequency of extreme high water, relevant for water management and flood control.

  11. Fuzzy logic control of steam generator water level in pressurized water reactors

    International Nuclear Information System (INIS)

    In this paper a fuzzy logic controller is applied to control the steam generator water level in a pressurized water reactor. The method does not require a detailed mathematical mode of the object to be controlled. The design is based on a set of linguistic rules that were adopted from the human operator's experience. After off-line fuzzy computation, the controller is a lookup table, and thus, real-time control is achieved. Shrink-and-swell phenomena are considered in the linguistic rules, and the simulation results show that their effect is dramatically reduced. The performance of the control system can also be improved by changing the input and output scaling factors, which is convenient for on-line tuning

  12. Investigations on boron levels in drinking water sources in China.

    Science.gov (United States)

    Xu, Ren-ji; Xing, Xiao-ru; Zhou, Qun-fang; Jiang, Gui-bin; Wei, Fu-sheng

    2010-06-01

    To evaluate boron contamination of public drinking water in China, both dissolved and total boron contents in 98 public drinking water sources from 49 cities, 42 brands of bottled water samples from supermarkets in several cities, and 58 water samples from boron industrial area were measured by inductively coupled plasma-mass spectrometry (ICP-MS). Our experimental results showed that boron existed in public drinking water sources mainly in dissolved status with total concentrations ranging from 0.003 to 0.337 mg/L (mean = 0.046 mg/L). The mean boron concentrations in mineral and pure bottled water were 0.052 and 0.028 mg/L, respectively. The results obtained in this work showed that there was no health risk on view of boron in public drinking water sources and bottled water. In boron industrial area, boron concentrations in surface water and ground water were 1.28 mg/L (range = 0.007-3.8 mg/L) and 18.3 mg/L (range = 0.015-140 mg/L), respectively, which indicated that boron industry caused boron pollution in local water system. PMID:19444639

  13. Study on pressurizer water level signal reconstruction based on support vector regression

    International Nuclear Information System (INIS)

    Pressurizer water level is an important monitoring parameter to marine pressurized water reactor for operator to estimate operation transient of the reactor. However, pressurizer often takes on problems of false water level, over-range measurement of water level and the loss of measuring. A method based on support vector regression was used to reconstruct the pressurizer water level according to the coupling relationship between pressurizer water level and other thermal-hydraulic parameters, such as the average temperature between reactor core inlet and outlet, pressure and temperature of pressurizer, coolant inventory of main loop system, and charge and drainage flow. Simulation analysis shows that the method can quickly, accurately and efficiently reconstruct the pressurizer water level signal under normal operating conditions. (authors)

  14. Level of Water Awareness at Some Jordanian Universities Studentâ??s

    Directory of Open Access Journals (Sweden)

    Mohamad Said Damanhouri

    2012-01-01

    Full Text Available Problem statement: Jordan has been facing shortage in water sector during the last three decades due to natural and society factors, weakness of water awareness is one of these Society factors, so this study focused on the level of water awareness in fields of; water significant in life, water problem in Jordan, water conservation at part of Jordanian society. Approach: The study aimed to Investigate how some Jordanian Universities students behave to identify the level of water awareness in sectors of water, giving students positive attitudes towards water resources and conservation, uses and reduce consumption. Encourage students for voluntary collective actions as A hope to raising water awareness. The society sample study were represented by (320 Jordanian Universities students, take in consideration the following variables: Academic specialists, sex, University status and average monthly income per family. Data base for previous variables obtained by special questioner prepared for this study. Data run to statistical analysis through some simple Descriptive statistical approaches as (ANOVA. Results: The study showed that the level of water awareness towards water significant at a weak level, it reached to (57% of sample study towards water conservation. Students of scientific specializes have water awareness more than humanitarian specializes. There isnâ??t impact of University status and average monthly income on the level of water awareness. Conclusion/Recommendations: Most of study sample recognized with significant of water at life, they admit that Jordan faced water problem, but female were more than male at the level of water awarenes, also scientific specialists more than humanitarian specialties. Study recommends to enrich the curriculum of humanitarian sciences, with more topics looking for water and encourage personal activities and volunteers work to conserve water and rationalized it, also activation laws and legislation related with water.

  15. Investigation of natural radioactivity level of the waters in Shandong Province

    International Nuclear Information System (INIS)

    The investigation results of neutral radioactivity level in river lake, reservoir, spring, well, offshore water and tap water in Shandong Province was reported. There were totally 245 samples collected from 102 measuring points. The results show that the radioactivity level of varied water bodies of the province was within normal natural background

  16. Comparison Of Vented And Absolute Pressure Transducers For Water-Level Monitoring In Hanford Site Central Plateau Wells

    International Nuclear Information System (INIS)

    Automated water-level data collected using vented pressure transducers deployed in Hanford Site Central Plateau wells commonly display more variability than manual tape measurements in response to barometric pressure fluctuations. To explain this difference, it was hypothesized that vented pressure transducers installed in some wells are subject to barometric pressure effects that reduce water-level measurement accuracy. Vented pressure transducers use a vent tube, which is open to the atmosphere at land surface, to supply air pressure to the transducer housing for barometric compensation so the transducer measurements will represent only the water pressure. When using vented transducers, the assumption is made that the air pressure between land surface and the well bore is in equilibrium. By comparison, absolute pressure transducers directly measure the air pressure within the wellbore. Barometric compensation is achieved by subtracting the well bore air pressure measurement from the total pressure measured by a second transducer submerged in the water. Thus, no assumption of air pressure equilibrium is needed. In this study, water-level measurements were collected from the same Central Plateau wells using both vented and absolute pressure transducers to evaluate the different methods of barometric compensation. Manual tape measurements were also collected to evaluate the transducers. Measurements collected during this study demonstrated that the vented pressure transducers over-responded to barometric pressure fluctuations due to a pressure disequilibrium between the air within the wellbores and the atmosphere at land surface. The disequilibrium is thought to be caused by the relatively long time required for barometric pressure changes to equilibrate between land surface and the deep vadose zone and may be exacerbated by the restriction of air flow between the well bore and the atmosphere due to the presence of sample pump landing plates and well caps. The disequilibrium is likely limited to wells screened across the water table (i.e., open to the deep vadose zone) where the depth to water is large or a low-permeability layer occurs in the vadose zone. Such wells are a pathway for air movement between the deep vadose zone and land surface and this sustains the pressure disequilibrium between the well bore and the atmosphere for longer time periods. Barometric over-response was not observed with the absolute pressure transducers because barometric compensation was achieved by directly measuring the air pressure within the well. Users of vented pressure transducers should be aware of the over-response issue in certain Hanford Site wells and ascertain if it will affect the use of the data. Pressure disequilibrium between the well and the atmosphere can be identified by substantial air movement through the wellbore. In wells exhibiting pressure disequilibrium, it is recommended that absolute pressure transducers be used rather than vented transducers for applications that require precise automated determinations of well water-level changes in response to barometric pressure fluctuations.

  17. COMPARISON OF VENTED AND ABSOLUTE PRESSURE TRANSDUCERS FOR WATER-LEVEL MONITORING IN HANFORD SITE CENTRAL PLATEAU WELLS

    Energy Technology Data Exchange (ETDEWEB)

    MCDONALD JP

    2011-09-08

    Automated water-level data collected using vented pressure transducers deployed in Hanford Site Central Plateau wells commonly display more variability than manual tape measurements in response to barometric pressure fluctuations. To explain this difference, it was hypothesized that vented pressure transducers installed in some wells are subject to barometric pressure effects that reduce water-level measurement accuracy. Vented pressure transducers use a vent tube, which is open to the atmosphere at land surface, to supply air pressure to the transducer housing for barometric compensation so the transducer measurements will represent only the water pressure. When using vented transducers, the assumption is made that the air pressure between land surface and the well bore is in equilibrium. By comparison, absolute pressure transducers directly measure the air pressure within the wellbore. Barometric compensation is achieved by subtracting the well bore air pressure measurement from the total pressure measured by a second transducer submerged in the water. Thus, no assumption of air pressure equilibrium is needed. In this study, water-level measurements were collected from the same Central Plateau wells using both vented and absolute pressure transducers to evaluate the different methods of barometric compensation. Manual tape measurements were also collected to evaluate the transducers. Measurements collected during this study demonstrated that the vented pressure transducers over-responded to barometric pressure fluctuations due to a pressure disequilibrium between the air within the wellbores and the atmosphere at land surface. The disequilibrium is thought to be caused by the relatively long time required for barometric pressure changes to equilibrate between land surface and the deep vadose zone and may be exacerbated by the restriction of air flow between the well bore and the atmosphere due to the presence of sample pump landing plates and well caps. The disequilibrium is likely limited to wells screened across the water table (i.e., open to the deep vadose zone) where the depth to water is large or a low-permeability layer occurs in the vadose zone. Such wells are a pathway for air movement between the deep vadose zone and land surface and this sustains the pressure disequilibrium between the well bore and the atmosphere for longer time periods. Barometric over-response was not observed with the absolute pressure transducers because barometric compensation was achieved by directly measuring the air pressure within the well. Users of vented pressure transducers should be aware of the over-response issue in certain Hanford Site wells and ascertain if it will affect the use of the data. Pressure disequilibrium between the well and the atmosphere can be identified by substantial air movement through the wellbore. In wells exhibiting pressure disequilibrium, it is recommended that absolute pressure transducers be used rather than vented transducers for applications that require precise automated determinations of well water-level changes in response to barometric pressure fluctuations.

  18. Measurements of wall pressure fluctuations on a cylinder in annular water flow with upstream disturbance. Part II. Flow spoilers

    International Nuclear Information System (INIS)

    The second part of an experimental study of wall-pressure fluctuations on a circular rod concentrically located in circular channels of three different hydraulic diameters is reported. Part I presented results with no upstream disturbances; this report is concerned with the effects of upstream flow spoilers. Experimental results from the measurement of fluctuating wall pressures are presented in various statistical forms, including power spectral density representations and mean-square values, as the basis for studying the effects of upstream disturbances and hydraulic diameter. The upstream disturbance generated by a grid-type spoiler is shown to have a more dominant effect on wall-pressure fluctuations than the other types of spoilers tested

  19. Tritium activity levels in environmental water samples from different origins

    Energy Technology Data Exchange (ETDEWEB)

    Palomo, M.; Penalver, A.; Aguilar, C. [Unitat de Radioquimica Ambiental i Sanitaria, Universitat Rovira i Virgili, Edifici CTT-FURV, Av. Paisos Catalans 18, 43007 Tarragona (Spain); Borrull, F. [Unitat de Radioquimica Ambiental i Sanitaria, Universitat Rovira i Virgili, Edifici CTT-FURV, Av. Paisos Catalans 18, 43007 Tarragona (Spain)], E-mail: francesc.borrull@urv.cat

    2007-09-15

    Tritium activity was determined in environmental waters from different areas of Catalonia, using a distillation procedure before liquid scintillation counting. The developed method was validated by analysing two samples from proficiency tests. In most of water samples (from rivers, rain, mineral bottled waters and tap waters) analysed, the activity values were lower or close to the minimum detectable activity (MDA) for our method which has a value of 0.6 Bq/l. However, the Ebro river samples had a mean activity around 3.6{+-}0.6Bq/l. The nuclear power station of Asco, which is located on the banks of this river, can be a source of tritium production and introduction into the environment, so a more exhaustive study of these waters was carried out. Tritium activities in this river were a long way above the normative limit in Spain for waters intended for human consumption, which is 100 Bq/l.

  20. Mathematical modelling of temperature fluctuations in the tube wall of a vertical sodium-water steam generator

    International Nuclear Information System (INIS)

    Wall temperature fluctuations due to phase boundary instability occur in the tubes of steam generators with pump-assisted circulation in the region where the liquid film dries out. The fluctuations result in additional temperature stress affecting high-cycle material fatigue and thus the tube life. In the calculation, periodic movement is considered of the phase boundary of various geometry. The random mode is modelled by a superposition of periodic processes with various frequencies. A comparison with experimental results shows good agreement confirming the acceptability of the methodology developed. (author)

  1. Influence of Closing Storm Surge Barrier on Extreme Water Levels and Water Exchange; The Limfjord, Denmark

    DEFF Research Database (Denmark)

    NØrgaard, JØrgen Quvang Harck; Bentzen, Thomas Ruby

    2014-01-01

    The Limfjord is the largest Danish estuary and is connected to both the North Sea in the west and the Kattegat in the east. The connection to the North Sea was formed in 1825 by a storm surge, and has since been kept open partly artificially. The debate about the climate changes and thereby the increased risk of flooding in the estuary has revitalized the discussion whether this connection should be closed. In this paper, it is shown by numerical simulation that the establishment of a storm surge barrier across Thyborøn Channel can significantly reduce the peak water levels in the central of the fjord. The reduction is obtained by blocking the ingoing flow with a sluice in due time before the storm surge peaks in the North Sea. In order to avoid problems with reduced water quality and salinity, the water exchange should be controlled by only keeping the sluice open for ingoing currents for the rest of days during the year. Depending on the effective cross-sectional area of the sluice, the depth-averaged salinity in the Limfjord remains status quo for cross-sectional areas of 500m2, whereas the salinity increases with up to 1.5 PSU for larger openings.

  2. Lowered tritium levels in river water indicate significant storage of water in a large catchment

    International Nuclear Information System (INIS)

    Tritium in the runoff of the Tugela river, in Kwazulu-Natal province on the east coast of South Africa, was monitored for a three year period from 1970 to 1972. The catchment above the runoff sampling site (Mandini) is 29089 km2 in extent; the altitude ranges from sea level to 3000 masl, the mean annual rainfall ranges from 700 to 1500 mm and the mean annual runoff ranges between 6 to 49% of the rainfall (that is 46 to 724 mm). Rainfall was monitored at three sites representing a range of altitudes and distance from the coast. Tritium in the river water was considerably lower than that of rainfall of the inland stations. A model for tritium in rainfall was used describing the increasing tritium content inland. Using the data of a rainfall-runoff model that describes 74 sub-catchments (200 to 1200 km2 in size) by their characteristic rainfall and runoff, it is possible to calculate the contribution of each sub-catchment to the total runoff at the sampling station. Labelling the runoff of each sub-catchment with the tritium level of its rainfall, enables the calculation of a weighted mean tritium content of annual input for the entire catchment. For the hydrological years (Oct-Sept) 1971/2 and 1972/3 these are 38 and 30 TU respectively. The weighted (by monthly flow) mean tritium level of the river is 26.6 and 26.3 TU for the same years. This suggest a large source of low-tritium water contributing to the Tugela runoff for both these seasons. This is all the more remarkable since the sampling period was six years after the bomb peak of tritium in the southern hemisphere (e.g. Pretoria station 6826200). Any carry-over water in the river from a previous year should actually increase the tritium content in the river. The sparseness of available data (two seasons) does not allow a detailed analysis of the residence times of water in the system and more recent measurements are just not available. Interpretation models that can be used are: a binary model indicating 74% of present year rainfall and 26% of pre-1960 (3.5 TU) water; a simple exponential (mixed box) model where the mean residence time will have to be as large as 7 to 9 years in order to introduce sufficient pre-bomb water. The rapid flow response to rainfall in the catchment and the low base flow in the river suggests that there is little storage available. Nevertheless, both the simplistic models require storage of water of a magnitude of at least the mean annual rainfall in the catchment. This discrepancy needs resolution

  3. Nitrates in drinking water and methemoglobin levels in pregnancy: a longitudinal study

    OpenAIRE

    Luke Barbara; Fleming Lora E; Messing Rita; Backer Lorraine C; Manassaram Deana M; Monteilh Carolyn P

    2010-01-01

    Abstract Background Private water systems are more likely to have nitrate levels above the maximum contaminant level (MCL). Pregnant women are considered vulnerable to the effects of exposure to high levels of nitrates in drinking water due to their altered physiological states. The level of methemoglobin in the blood is the biomarker often used in research for assessing exposure to nitrates. The objective of this study was to assess methemoglobin levels and examine how various factors affect...

  4. Water Hardness Level and ItAND#8217;s Health Effects

    Directory of Open Access Journals (Sweden)

    Necmettin Kocak

    2011-04-01

    Full Text Available Water hardness is a term used to define the number of ions contained in the water, especially quantity sulphate, carbonate salts of calcium and magnesium. This characteristis of water is a important quality in it’s use as drinking water, industrial water and service water. The temporary hardness level of water cames from bicarbonate salts of calcium and magnesium whereas chloride, sulphate, nitrate, phosphate, silicate salts of calcium and magnesium. In order to indicate the hardness level of water samples French Hardness Level is used in our country. There is a larger amounth of calcium and magnesium salts in hard water samples. These minerals have very important functions in the human body. In this study, the importance of hard water in terms of human health has been assessed under light of current information. The studies about the preventive role of hard water in cardiovascular diseases, cerebrovascular diseases, stroke and many types of cancer areviewed. These studies Express that higher levels of calcium and magnesium hard water provide a higher reduction in these disease. Water, which must be consumed as 2 liters per dayis very important for human life. Hard water contains a lot of the minerals that must be taker daily, especially calcium and magnesium. It’s advised that water for consumption to have medium hardness. The hardness level of water is an aesthetic quality. Thus, in populations having a taste for soft water, the effort of individuals to softer the network water provided by municipalities using different equipments, in addition to their preference of soft water in plastic or glass bottles for consumption could imply lack of benefit of hard water for population health and also bring out some risks in terms of water hygiene. [TAF Prev Med Bull 2011; 10(2.000: 187-192

  5. Stochastic modeling of Lake Van water level time series with jumps and multiple trends

    Directory of Open Access Journals (Sweden)

    H. Aksoy

    2013-06-01

    Full Text Available In the 1990s, water level in the closed-basin Lake Van located in the Eastern Anatolia, Turkey, has risen up about 2 m. Analysis of the hydrometeorological data shows that change in the water level is related to the water budget of the lake. In this study, stochastic models are proposed for simulating monthly water level data. Two models considering mono- and multiple-trend time series are developed. The models are derived after removal of trend and periodicity in the dataset. Trend observed in the lake water level time series is fitted by mono- and multiple-trend lines. In the so-called mono-trend model, the time series is treated as a whole under the hypothesis that the lake water level has an increasing trend. In the second model (so-called multiple-trend, the time series is divided into a number of segments to each a linear trend can be fitted separately. Application on the lake water level data shows that four segments, each fitted with a trend line, are meaningful. Both the mono- and multiple-trend models are used for simulation of synthetic lake water level time series under the hypothesis that the observed mono- and multiple-trend structure of the lake water level persist during the simulation period. The multiple-trend model is found better for planning the future infrastructural projects in surrounding areas of the lake as it generates higher maxima for the simulated lake water level.

  6. Core level spectroscopy of neon- and water-clusters

    International Nuclear Information System (INIS)

    We present high resolution K-shell absorption spectra of neon and water clusters from the monomer to the solid. Shifts in the pre edge absorption are discussed and first EXAFS data presented. For water clusters a photoelectron study supplements the results. (author)

  7. 1:750,000-scale static ground-water levels of Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of static ground-water levels for the State of Nevada based on a 1974 ground-water map (Rush, 1974) published by the Nevada Department of...

  8. Investment choice and perceived mating intentions regulated by external resource cues and internal fluctuation in blood glucose levels

    OpenAIRE

    Rao, Li-Lin; Wang, Xiao-Tian; Li, Shu

    2015-01-01

    We examined resource allocation priorities in the framework of an updated Maslow hierarchy of fundamental human needs. In Experiment 1, the participants in the food abundance priming condition viewing photos of high-calorie food allocated more money to savings than to spending. However, the participants preferred spending to savings under the condition of mating availability priming with romantic photographs. In Experiment 2, before and after drinking either water or a sugary beverage, fastin...

  9. Water Resources Data, Georgia, 2001, Volume 2: Continuous ground-water level data, and periodic surface-water- and ground-water-quality data, Calendar Year 2001

    Science.gov (United States)

    Coffin, Robert; Grams, Susan C.; Cressler, Alan M.; Leeth, David C.

    2001-01-01

    Water resources data for the 2001 water year for Georgia consists of records of stage, discharge, and water quality of streams; and the stage and contents of lakes and reservoirs published in two volumes in a digital format on a CD-ROM. Volume one of this report contains water resources data for Georgia collected during water year 2001, including: discharge records of 133 gaging stations; stage for 144 gaging stations; precipitation for 58 gaging stations; information for 19 lakes and reservoirs; continuous water-quality records for 17 stations; the annual peak stage and annual peak discharge for 76 crest-stage partial-record stations; and miscellaneous streamflow measurements at 27 stations, and miscellaneous water-quality data recorded by the NAWQA program in Georgia. Volume two of this report contains water resources data for Georgia collected during calendar year 2001, including continuous water-level records of 159 ground-water wells and periodic records at 138 water-quality stations. These data represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in Georgia. Note: Historically, this report was published as a paper report. For the 1999 and subsequent water-year reports, the Water Resources Data for Georgia changed to a new, more informative and functional format on CD-ROM. The format is based on a geographic information system (GIS) user interface that allows the user to view map locations of the hydrologic monitoring stations and networks within respective river basins. To obtain a copy of the CD version of this report, you may call the U.S. Geological Survey office in Atlanta at (770) 903-9100, or send e-mail to request the publication. Please include your name and mailing address in your e-mail.

  10. Mesoscopic fluctuations, two-parameter scaling and concommitant unusual level spacing distributions in finite 1D disordered systems

    International Nuclear Information System (INIS)

    We study level spacing distributions of finite-sized one-dimensional disordered systems. As the system evolves from a quasi-ballistic to a strongly localized regime, the system crosses over from a strongly non-Wigner-Dyson type level spacing distribution to a universal Poisson distribution in the thermodynamic (L??) limit. In between it goes through regimes where the distribution seems to be a mixture of Wigner-Dyson type and Poisson type distributions, thus indicating existence of pre-localized states before the thermodynamic limit sets in. (author)

  11. Fuzzy Control of Water Level and Temperature in Fish Eggs Breeding Tank with Different Sensor Inputs

    OpenAIRE

    Tarik Namas

    2013-01-01

    In this paper fuzzy logic principles are used to control the level and temperature of water in fish eggs breading tank. The control task aims to keep the water level and the water temperature in a tank within certain ranges, the temperature due to Newton’s law of cooling would drop down, and to keep it within limits, hot water is added, and cold water is drained. Sensors for temperature and level are used to give fuzzy input to the fuzzy controller which outputs the amount of opening in the t...

  12. Identification and simulation for steam generator water level based on Kalman Filter

    International Nuclear Information System (INIS)

    In order to effectively control the water level of the steam generator (SG), this paper has set about the state-observer theory in modern control and put forward a method to detect the 'false water level' based on Kalman Filter. Kalman Filter is a efficient tool to estimate state-variable by measured value including noise. For heavy measurement noise of steam flow, constructing a 'false water level' observer by Kalman Filter could availably obtain state variable of 'false water level'. The simulation computing for the dynamics characteristic of nuclear SG water level process under several typically running power was implemented by employing the simulation model. The result shows that the simulation model accurately identifies the 'false water level' produced in the reverse thermal-dynamic effects of nuclear SG water level process. The simulation model can realize the precise analysis of dynamics characteristic for the nuclear SG water level process. It can provide a kind of new ideas for the 'false water level' detecting of SG. (authors)

  13. Digitization and simulation realization of full range control system for steam generator water level

    International Nuclear Information System (INIS)

    In this paper, a full range digital control system for the steam generator water level is designed by a control scheme of single element control and three-element cascade feed-forward control, and the method to use the software module configuration is proposed to realize the water level control strategy. This control strategy is then applied in the operation of the nuclear power simulation machine. The simulation result curves indicate that the steam generator water level maintains constant at the stable operation condition, and when the load changes, the water level changes but finally maintains the constant. (authors)

  14. Challenge to high-activity-level water treatment by adsorbents

    International Nuclear Information System (INIS)

    There are over 280,000 tonnes of contaminated water in the damaged Fukushima Daiichi Nuclear Plant site in various tanks and barges and a large amount of contaminated water is now producing at the rate of several tonnes/day owing to inevitable cooling of the reactor cores. SARRY (Simplified Active Water Retrieve and Recovery System) and ALPS (Advanced Liquid Processing System) are installed to remove Cs and multi-elements respectively utilizing ion exchangers (zeolite, crystalline silicon titanate, and metal ferrocyanides) from contaminated water. The author continues efforts to find effective and selective adsorbents for Cs and Sr by measuring partition data, adsorption isotherms and adsorption rate referring with chemical structure elucidated from X-ray diffraction and SEM techniques. The obtained data are presented. (S. Ohno)

  15. Nanosecond fluctuation kinetics of luminescence hopping quenching originated from the 5d1 level in the Ce3+:YPO4·0.8H2O nanocrystals

    International Nuclear Information System (INIS)

    We study the nanosecond energy transfer kinetics detected at dipole allowed 5d1–4f1 transition and originated from the lowest 2?1 level of the Ce3+ ions doped into the rhabdophane-type YPO4·0.8H2O nanocrystals synthesized by microwave hydrothermal treatment. We show that the luminescence quenching in the nanocrystals is determined by two processes depending on Ce3+ (energy donor) concentration at constant OH? (energy acceptors) concentration. At 0.2 mol% Ce3+ the luminescence quenching is mainly determined by direct (static) quenching caused by vibrations of OH? groups. At 2.0 mol% Ce3+ the quenching accelerates due to energy migration from the Ce3+ ions with poor acceptor surrounding to the Ce3+ ions with the nearby OH? acceptors. In the latter case we observe fluctuation kinetics of the luminescence impurity hopping quenching starting immediately after static ordered stage of the decay kinetics. We obtain that for dipole allowed the 5d–4f transition in the Ce3+ donor the CDD microparameter of the Ce3+–Ce3+ energy migration and CDA microparameter of Ce3+–OH? energy transfer are in strong correlation with the higher spontaneous emission rate for dipole allowed transition in Ce3+ comparing to dipole forbidden transition in Nd3+. -- Highlights: • We prepare the Ce3+:YPO4·0.8H2O nanocrystals of mean D=42 nm by microwave–hydrothermal synthesis. • We detect luminescence quenching of Ce3+ the 5d1(2?1) level caused by OH? vibrations. • We find that the static quenching caused by vibrations of OH? molecular groups dominates at 0.2% of Ce3+. • We find that Ce3+–Ce3+ energy migration accelerates the Ce3+–OH? quenching at 2% of Ce3+. • We detect nanosecond fluctuation kinetics of hopping quenching immediately after an ordered static stage

  16. The link between unemployment and crime rate fluctuations: An analysis at the county, state, and national levels.

    Science.gov (United States)

    Phillips, Julie; Land, Kenneth C

    2012-05-01

    Cantor and Land (1985) developed a theoretical model that proposed two pathways through which economic activity - as indexed by the aggregate unemployment rate - could affect the rate of criminal activity. The first is by increasing levels of criminal motivation within the population as deteriorating economic conditions affect social strain and social control; the second is by influencing the availability and vulnerability of criminal targets and thus the number of criminal opportunities. Although much empirical research has applied this theoretical model, few analyses have done so at disaggregated units of analysis. We present the most comprehensive analysis to date by empirically evaluating this model with data on 400 of the largest US counties - and examine the effects of aggregation on results as these county data are combined to the state and national levels - for the years 1978-2005. For seven Index crimes at each of the three levels of analysis, and with or without controls for structural covariates at each level, the directional effects hypothesized by Cantor and Land are found for 78 out of 84 estimated relationships. Even after taking into account the lack of statistical independence of these estimates by drawing on recently developed statistical theory, this is a very unlikely outcome. In accordance with expectations based on theory and prior research, (a) some of these relationships are weak and not statistically significant, and (b) the strongest and most consistent patterns of relationships for both the crime opportunity and crime motivation effects are found for three property crimes: burglary, larceny, and motor vehicle theft. Suggestions for further research on this topic are given. PMID:23017802

  17. Elevated levels of radioactivity in water wells in Los Angeles and Orange Counties, California

    International Nuclear Information System (INIS)

    Levels of gross alpha particle radioactivity nearly three times the maximum contamination levels (MCL) have been detected for several years in well waters and related surface waters in Los Angeles and Orange Counties, California. A few elevated levels of uranium have also been recorded. The affected wells and related surface waters represent only a minor fraction of the water sampled and tested in this area. None of the excessive radioactivity is believed to persist in the municipal waters sold to the public, due to the customary blending of waters from several wells or sources which water purveyors practice. This papers is a preliminary survey of the occurrence, possible sources, fate, and implications of these elevated radioactivity levels

  18. A New Approach to Reconstruct Ancient Bottom Water Oxygen Levels

    Science.gov (United States)

    Rathburn, A. E.; Willingham, J.; Corliss, B. H.; Burkett, A. M.; Ziebis, W.

    2014-12-01

    Oxygen availability controls many biological and geochemical processes, and serves as an important indicator of paleoceanographic characteristics. Recent work has demonstrated a direct relationship between oxygen acquisition and pores on benthic foraminiferal tests. Epifaunal foraminifera (living near or above the sediment-water interface) are directly exposed to bottom water, and can occur in abundance in a wide range of seafloor environments. In this study, a novel approach using ArcGIS and image analysis techniques was used to determine the percentage of test chamber surface area covered by pores in living and recently living (Rose Bengal stained) epifaunal taxa (Cibicides, Cibicidoides and Planulina). Analyses of Scanning Electron Microscope images of 97 specimens collected from 20 deep-sea locations having different bottom water oxygen concentrations (0.04 to 6.20 ml/L) revealed a robust (R2= 0.729; p < 0.001), negative relationship between pore surface area on test chambers and ambient bottom water oxygen concentration. The resulting calibration curve serves as new, quantitative proxy to assess bottom water oxygen of ancient oceans.

  19. Natural radiation level in drinking water in Homs city

    International Nuclear Information System (INIS)

    In this study, radon concentrations were measured at the sources of drinking water and in some tap water in houses in Homs County. All measurements showed that concentrations are within the international allowed limits and there is no big difference in concentration between the sources and the houses. Also total alpha/beta and radium-226 content were measured in the samples of the sources and the houses using liquid scintillation counter. All measurements showed that concentrations are within the international allowed limits. (authors)

  20. Hydrology and water quality of Shell Lake, Washburn County, Wisconsin, with special emphasis on the effects of diversion and changes in water level on the water quality of a shallow terminal lake

    Science.gov (United States)

    Juckem, Paul F.; Robertson, Dale M.

    2013-01-01

    Shell Lake is a relatively shallow terminal lake (tributaries but no outlets) in northwestern Wisconsin that has experienced approximately 10 feet (ft) of water-level fluctuation over more than 70 years of record and extensive flooding of nearshore areas starting in the early 2000s. The City of Shell Lake (City) received a permit from the Wisconsin Department of Natural Resources in 2002 to divert water from the lake to a nearby river in order to lower water levels and reduce flooding. Previous studies suggested that water-level fluctuations were driven by long-term cycles in precipitation, evaporation, and runoff, although questions about the lake’s connection with the groundwater system remained. The permit required that the City evaluate assumptions about lake/groundwater interactions made in previous studies and evaluate the effects of the water diversion on water levels in Shell Lake and other nearby lakes. Therefore, a cooperative study between the City and U.S. Geological Survey (USGS) was initiated to improve the understanding of the hydrogeology of the area and evaluate potential effects of the diversion on water levels in Shell Lake, the surrounding groundwater system, and nearby lakes. Concerns over deteriorating water quality in the lake, possibly associated with changes in water level, prompted an additional cooperative project between the City and the USGS to evaluate efeffects of changes in nutrient loading associated with changes in water levels on the water quality of Shell Lake. Numerical models were used to evaluate how the hydrology and water quality responded to diversion of water from the lake and historical changes in the watershed. The groundwater-flow model MODFLOW was used to simulate groundwater movement in the area around Shell Lake, including groundwater/surface-water interactions. Simulated results from the MODFLOW model indicate that groundwater flows generally northward in the area around Shell Lake, with flow locally converging toward the lake. Total groundwater inflow to Shell Lake is small (approximately 5 percent of the water budget) compared with water entering the lake from precipitation (83 percent) and surface-water runoff (13 percent). The MODFLOW model also was used to simulate average annual hydrologic conditions from 1949 to 2009, including effects of the removal of 3 billion gallons of water during 2003–5. The maximum decline in simulated average annual water levels for Shell Lake due to the diversion alone was 3.3 ft at the end of the diversion process in 2005. Model simulations also indicate that although water level continued to decline through 2009 in response to local weather patterns (local drought), the effects of the diversion decreased after the diversion ceased; that is, after 4 years of recovery (2006–9), drawdown attributable to the diversion alone decreased by about 0.6 ft because of increased groundwater inflow and decreased lake-water outflow to groundwater caused by the artificially lower lake level. A delayed response in drawdown of less than 0.5 ft was transmitted through the groundwater-flow system to upgradient lakes. This relatively small effect on upgradient lakes is attributed in part to extensive layers of shallow clay that limit lake/groundwater interaction in the area. Data collected in the lake indicated that Shell Lake is polymictic (characterized by frequent deep mixing) and that its productivity is limited by the amount of phosphorus in the lake. The lake was typically classified as oligotrophic-mesotrophic in June, mesotrophic in July, and mesotrophic-eutrophic in August. In polymictic lakes like Shell Lake, phosphorus released from the sediments is not trapped near the bottom of the lake but is intermittently released to the shallow water, resulting in deteriorating water quality as summer progresses. Because the productivity of Shell Lake is limited by phosphorus, the sources of phosphorus to the lake were quantified, and the response in water quality to changes in phosphorus inputs were evaluated by means of eutrophication mo

  1. Nitrates in drinking water and methemoglobin levels in pregnancy: a longitudinal study

    Directory of Open Access Journals (Sweden)

    Luke Barbara

    2010-10-01

    Full Text Available Abstract Background Private water systems are more likely to have nitrate levels above the maximum contaminant level (MCL. Pregnant women are considered vulnerable to the effects of exposure to high levels of nitrates in drinking water due to their altered physiological states. The level of methemoglobin in the blood is the biomarker often used in research for assessing exposure to nitrates. The objective of this study was to assess methemoglobin levels and examine how various factors affected methemoglobin levels during pregnancy. We also examined whether differences in water use practices existed among pregnant women based on household drinking water source of private vs. public supply. Methods A longitudinal study of 357 pregnant women was conducted. Longitudinal regression models were used to examine changes and predictors of the change in methemoglobin levels over the period of gestation. Results Pregnant women showed a decrease in methemoglobin levels with increasing gestation although Conclusion Pregnant women potentially exposed to nitrate levels primarily below the MCL for drinking water were unlikely to show methemoglobin levels above the physiologic normal. Water use practices such as the use of treatment devices to remove nitrates varied according to water source and should be considered in the assessment of exposure to nitrates in future studies.

  2. Fluorine level in some city water supplies of Bangladesh

    International Nuclear Information System (INIS)

    Nuclear reaction based Proton Induced Gamma Emission (PIGE) analytical method was employed for the quantitative measurement of fluorine in the city water supplies of the major cities of Bangladesh. 102 water samples collected from 14 city supplies were analyzed and these samples contain fluorine in the range of 0.03 to 1.10 mg/L with a mean of 0.33 ± 0.21 mg/L. It was also observed that except the samples of Barisal, Dinajpur and Rajshahi, all other water samples analyzed contain a much lower amount of fluorine than the maximum permissible value for Bangladesh in drinking water, which is 1 mg/L. The mean concentration of fluorine in the samples of Barisal, Dinajpur and Rajshahi are respectively 0.79±0.01, 0.71±0.13 and 0.92±0.18 mg/L. For the 55 samples of Dhaka city supply the mean fluorine concentration is 0.31±0.17 mg/L and that of 9 samples from Chittagong city supply is 0.19±0.10 mg/L, which is the lowest among the 14 city supply samples analyzed in this study

  3. Estimation of missing water-level data for the Everglades Depth Estimation Network (EDEN), 2013 update

    Science.gov (United States)

    Petkewich, Matthew D.; Conrads, Paul A.

    2013-01-01

    The Everglades Depth Estimation Network is an integrated network of real-time water-level gaging stations, a ground-elevation model, and a water-surface elevation model designed to provide scientists, engineers, and water-resource managers with water-level and water-depth information (1991-2013) for the entire freshwater portion of the Greater Everglades. The U.S. Geological Survey Greater Everglades Priority Ecosystems Science provides support for the Everglades Depth Estimation Network in order for the Network to provide quality-assured monitoring data for the U.S. Army Corps of Engineers Comprehensive Everglades Restoration Plan. In a previous study, water-level estimation equations were developed to fill in missing data to increase the accuracy of the daily water-surface elevation model. During this study, those equations were updated because of the addition and removal of water-level gaging stations, the consistent use of water-level data relative to the North American Vertical Datum of 1988, and availability of recent data (March 1, 2006, to September 30, 2011). Up to three linear regression equations were developed for each station by using three different input stations to minimize the occurrences of missing data for an input station. Of the 667 water-level estimation equations developed to fill missing data at 223 stations, more than 72 percent of the equations have coefficients of determination greater than 0.90, and 97 percent have coefficients of determination greater than 0.70.

  4. Investigation of natural radioactivity level of the waters in Fujian Province

    International Nuclear Information System (INIS)

    The authors report the investigation results of natural radioactivity level in river, reservoir, offshore, spring, well and tap water in Fujian Province. There were totally 128 samples collected from 91 measuring points. The results show that the radioactivity level of varied water bodies of the province was within normal natural background

  5. Investigation and assessment on artificial radioactivity level in waters in Shanghai

    International Nuclear Information System (INIS)

    Investigation and assessment on artificial radioactivity level in river, lake, reservoir and tap waters in Shanghai from 1989?1991 have been done. Totally 45 samples from 15 measuring sites in dry and wet seasons were collected. The results showed that the radioactivity level of various water bodies in Shanghai were within normal background value

  6. Investigation of natural radioactivity level of the waters in the tibet autonomous region

    International Nuclear Information System (INIS)

    The investigation results of natural radioactivity level in river, lake, spring, well and tap water in the Tibet Autonomous Region is reported. There were totally 46 samples collected from 53 measuring points. The results show that the radioactivity level of water bodies of the Tibet Autonomous region was within normal natural background

  7. Sub-tidal water-level oscillations in the Mandovi estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.; Vijith, V.

    Using water-level data collected at six locations during March–April 2003 in the main channel of the Mandovi estuary, one of the 50 odd estuaries on the west coast of India, we describe the nature of variability of water level in the estuary...

  8. Investigation of natural radioactivity level of the waters in Qinghai Province

    International Nuclear Information System (INIS)

    The paper reports the investigation results of natural radioactivity level in rivers, lakes, reservoirs, springs, wells and tap water in Qinghai Province. There were totally 137 samples collected from 113 measuring points. The results show that the radioactivity level of varied water bodies of the Qinghai Province was within normal natural background

  9. The effect of water used in toilets on indoor radon level

    International Nuclear Information System (INIS)

    Plastic and small columnar glass cup 222Rn monitoring dosimeters and CR-39 detectors were used. The dependence of indoor radon level on normally used water in toilet in dwelling was surveyed. The ratio of radon level in various monitoring sites is in water tank : below a lid of the tank : on the lid: bedroom: in balcony = 300 : 5 :1: 0.4-0.8 : 0.2-0.3. The effect of normally used water in a toilet of dwelling on indoor radon level is very small if the water tank with a cover is used. (Author)

  10. Water Stability and Nutrient Leaching of Different Levels of Maltose Formulated Fish Pellets

    OpenAIRE

    Ighwela, Keri Alhadi; Ahmad, Aziz Bin; Abol-Munafi, A. B.

    2014-01-01

    The effects of different levels of maltose on feed pellet water stability and nutrient leaching were studied. Five treatments, including control with three replicates with setup (0.0, 20, 25, 30 and 35%). Pellet leaching rates were used to indicate pellet water stability. The results show that the presence of maltose in the diets significantly improved pellet water stability (p

  11. Levels regime and radionuclide distribution in ground waters of reclamation systems

    International Nuclear Information System (INIS)

    Main meteorological characteristics of long standing and weather in 1986-1988 were considered for 30-km area near the Chernobyl' NPP. Ground waters were analyzed because they were an important factor in the radionuclide migration. Radioactivity of ground waters amounted n x 10-10 Ci/l in 1988. Necessity to reduce the ground water levels was discussed. 5 figs.; 5 tabs

  12. Do Estimates of Water Productivity Enhance Understanding of Farm-Level Water Management?

    OpenAIRE

    Dennis Wichelns

    2014-01-01

    Estimates of water productivity are appearing with increasing frequency in the literature pertaining to agronomy, water management, and water policy. Some authors report such estimates as one of the outcome variables of experiment station studies, while others calculate water productivities when comparing regional crop production information. Many authors suggest or imply that higher values of water productivity are needed to ensure that future food production goals are achieved. Yet maximizi...

  13. Persistent water level changes in a well near Parkfield, California, due to local and distant earthquakes

    Science.gov (United States)

    Roeloffs, Evelyn A.

    1998-01-01

    Coseismic water level rises in the 30-m deep Bourdieu Valley (BV) well near Parkfield, California, have occurred in response to three local and five distant earthquakes. Coseismic changes in static strain cannot explain these water level rises because (1) the well is insensitive to strain at tidal periods; (2) for the distant earthquakes, the expected coseismic static strain is extremely small; and (3) the water level response is of the incorrect sign for the local earthquakes. These water level changes must therefore be caused by seismic waves, but unlike seismic water level oscillations, they are monotonic, persist for days or weeks, and seem to be caused by waves with periods of several seconds rather than long-period surface waves. Other investigators have reported a similar phenomenon in Japan. Certain wells consistently exhibit this type of coseismic water level change, which is always in the same direction, regardless of the earthquake's azimuth or focal mechanism, and approximately proportional to the inverse square of hypocentral distance. To date, the coseismic water level rises in the B V well have never exceeded the seasonal water level maximum, although their sizes are relatively well correlated with earthquake magnitude and distance. The frequency independence of the well's response to barometric pressure in the frequency band 0.1 to 0.7 cpd implies that the aquifer is fairly well confined. High aquifer compressibility, probably due to a gas phase in the pore space, is the most likely reason why the well does not respond to Earth tides. The phase and amplitude relationships between the seasonal water level and precipitation cycles constrain the horizontal hydraulic diffusivity to within a factor of 4.5, bounding hypothetical earthquake-induced changes in aquifer hydraulic properties. Moreover, changes of hydraulic conductivity and/or diffusivity throughout the aquifer would not be expected to change the water level in the same direction at every time of the year. The first 2.5 days of a typical coseismic water level rise could be caused by a small coseismic discharge decrease at a point several tens of meters from the well. Alternatively, the entire coseismic water level signal could represent diffusion of an abrupt coseismic pore pressure increase within several meters of the well, produced by a mechanism akin to that of liquefaction. The coseismic water level changes in the BV well resemble, and may share a mechanism with, coseismic water level, stream discharge, and groundwater temperature changes at other locations where preearthquake changes have also been reported. No preearthquake changes have been observed at the BV well site, however.

  14. Assessing the effect of different river water level interpolation schemes on modeled groundwater residence times

    Science.gov (United States)

    Diem, Samuel; Renard, Philippe; Schirmer, Mario

    2014-03-01

    Obtaining a quantitative understanding of river-groundwater interactions is of high practical relevance, for instance within the context of riverbank filtration and river restoration. Modeling interactions between river and groundwater requires knowledge of the river's spatiotemporal water level distribution. The dynamic nature of riverbed morphology in restored river reaches might result in complex river water level distributions, including disconnected river branches, nonlinear longitudinal water level profiles and morphologically induced lateral water level gradients. Recently, two new methods were proposed to accurately and efficiently capture 2D water level distributions of dynamic rivers. In this study, we assessed the predictive capability of these methods with respect to simulated groundwater residence times. Both methods were used to generate surface water level distributions of a 1.2 km long partly restored river reach of the Thur River in northeastern Switzerland. We then assigned these water level distributions as boundary conditions to a 3D steady-state groundwater flow and transport model. When applying either of the new methods, the calibration-constrained groundwater flow field accurately predicted the spatial distribution of groundwater residence times; deviations were within a range of 30% when compared to residence times obtained using a reference method. We further tested the sensitivity of the simulated groundwater residence times to a simplified river water level distribution. The negligence of lateral river water level gradients of 20-30 cm on a length of 200 m caused errors of 40-80% in the calibration-constrained groundwater residence time distribution compared to results that included lateral water level gradients. The additional assumption of a linear water level distribution in longitudinal river direction led to deviations from the complete river water level distribution of up to 50 cm, which caused wide-spread errors in simulated groundwater residence times of 200-500%. For an accurate simulation of groundwater residence times, it is therefore imperative that the longitudinal water level distribution is correctly captured and described. Based on the confirmed predictive capability of the new methods to estimate 2D river water level distributions, we can recommend their application to future studies that model dynamic river-groundwater systems.

  15. Long term fluctuations of groundwater mine pollution in a sulfide mining district with dry Mediterranean climate: Implications for water resources management and remediation.

    Science.gov (United States)

    Caraballo, Manuel A; Macías, Francisco; Nieto, José Miguel; Ayora, Carlos

    2016-01-01

    Water resources management and restoration strategies, and subsequently ecological and human life quality, are highly influenced by the presence of short and long term cycles affecting the intensity of a targeted pollution. On this respect, a typical acid mine drainage (AMD) groundwater from a sulfide mining district with dry Mediterranean climate (Iberian Pyrite Belt, SW Spain) was studied to unravel the effect of long term weather changes in water flow rate and metal pollutants concentration. Three well differentiated polluting stages were observed and the specific geochemical, mineralogical and hydrological processes involved (pyrite and enclosing rocks dissolution, evaporitic salts precipitation-redisolution and pluviometric long term fluctuations) were discussed. Evidencing the importance of including longer background monitoring stage in AMD management and restoration strategies, the present study strongly advise a minimum 5-years period of AMD continuous monitoring previous to the design of any AMD remediation system in regions with dry Mediterranean climate. PMID:26379258

  16. The Organochlorine Pesticides Residue Levels in Karun River Water

    OpenAIRE

    Behrooz Jannat; Abdolazim Behfar; Zahra Nazari; Mohammad Hassan Rabiee; Gholamreza Raeesi; Mohammad Reza Oveisi; Nafiseh Sadeghi

    2013-01-01

    Background: The organochlorine pesticides (OCPs) are among the most commonly used in water streams around the world. Most of these contaminants are highly hydrophobic and persist in sediments of rivers and lakes. Studies have suggested that OCPs may affect the normal function of the human and wildlife endocrine systems.Objectives: The aim of this study is to determine the concentrations of selected organochlorine pesticides residues [OP'DDT, PP'DDT, alderin, dieldrin, heptachlor, (?,ß,?,?) HC...

  17. Lake-level fluctuations since the Last Glaciation in Selin Co (lake), Central Tibet, investigated using optically stimulated luminescence dating of beach ridges

    International Nuclear Information System (INIS)

    This paper presents a preliminary study on lake-level fluctuations since the Last Glaciation in Selin Co (lake), Central Tibet, by dating four groups of beach ridges using optically stimulated luminescence (OSL). The highest/oldest beach ridge group (>100 m higher than the current lake level) is dated back to 67.9 ± 2.4 ka BP, corresponding to the early stage of the Last Glaciation (marine isotope stage (MIS) 4). This date further supports that no plateau-scale ice sheet covered the Tibetan Plateau during the Last Glaciation. The other three groups produce OSL ages of 30.4 ± 2.9 to 18.6 ± 1.7, 12.5 ± 1.6 to 9.2 ± 0.5, and 6.9 ± 0.2 ka BP respectively, most likely corresponding to cold or wet climate periods of the late stage of the Last Glaciation (MIS 2), deglaciation, and Holocene Hypsithermal. On the plateau scale, these four beach ridge groups are almost synchronous with advances or standstills of Himalayan glaciers, indicating similar climate controls across the central and southern Tibetan Plateau, and being consistent with the conclusion, obtained from nearby ice core records, that this area is affected by the South Asia monsoon. Furthermore, beach ridges are also synchronous with fluvial terraces in the northern Tibetan Plateau, implying common driving forces during their formation. Therefore, some terraces may be formed as a result of climate events rather than being of tectonic origin.

  18. The study of chloroform levels during water disinfection by chlorination reference to health risk in drinking water of karachi (pakistan)

    International Nuclear Information System (INIS)

    This study presents the levels of the chloroform formation during water disinfiction treatment by chlorination with the subsequent formation of by-products like trihalomethanes (THMs) are formed. These THMs in drinking water are found in the form of chloroform, bromodichloromethane, Chlorodibromomethane and bromoform. Out of these four compounds chloroform is the major culprit and Contribute 9.0% of the total THMs concentration (I). Therefore the present work was focused on the Estimation of levels of chloroform in the drinking water samples of Karachi city (Pakistan) by using Bootstrapping statistical technique with regards to the average cancer risk in the community. (author)

  19. Water Scarcity and Allocation in the Tarim Basin: Decision Structures and Adaptations on the Local Level

    Directory of Open Access Journals (Sweden)

    Niels Thevs

    2011-01-01

    Full Text Available The Tarim River is the major water source for all kinds of human activities and for the natural ecosystems in the Tarim Basin, Xinjiang, China. The major water consumer is irrigation agriculture, mainly cotton. As the area under irrigation has been increasing ever since the 1950s, the lower and middle reaches of the Tarim are suffering from a water shortage. Within the framework of the Water Law and two World Bank projects, the Tarim River Basin Water Resource Commission was founded in 1997 in order to foster integrated water resource management along the Tarim River. Water quotas were fixed for the water utilization along the upstream and downstream river stretches. Furthermore, along each river stretch, quotas were set for water withdrawal by agriculture and industry and the amount of water to remain for the natural ecosystems (environmental flow. Furthermore, huge investments were undertaken in order to increase irrigation effectiveness and restore the lower reaches of the Tarim River. Still, a regular water supply for water consumers along the Tarim River cannot be ensured. This paper thus introduces the hydrology of the Tarim River and its impacts on land use and natural ecosystems along its banks. The water administration in the Tarim Basin and the water allocation plan are elaborated upon, and the current water supply situation is discussed. Finally, the adaptations made due to issues of water allocation and water scarcity on the farm level are investigated and discussed.

  20. Levels of E.coli contamination of River Awach and household water in western Kenya

    OpenAIRE

    Abigael Akoth Okoko; Maurice Oyake

    2012-01-01

    Approximately 2.2 million diarrheal disease deaths occur annually, predominantly in children in developing countries due to inadequate access to clean drinking water. A large part of the populace in Nyanza lack clean drinking water yet the region hosts Lake Victoria. Konyango Jieri residents continue to suffer from waterborne diseases. The objective of this study was to determine the level of faecal contamination in source and household water. Water samples were drawn from eight draw-off poin...

  1. Fuzzy logic control of water level in advanced boiling water reactor

    International Nuclear Information System (INIS)

    The feedwater control system in the Advanced Boiling Water Reactor (ABWR) is more challenging to design compared to other control systems in the plant, due to the possible change in level from void collapses and swells during transient events. A basic fuzzy logic controller is developed using a simplified ABWR mathematical model to demonstrate and compare the performance of this controller with a simplified conventional controller. To reduce the design effort, methods are developed to automatically tune the scaling factors and control rules. As a first step in developing the fuzzy controller, a fuzzy controller with a limited number of rules is developed to respond to normal plant transients such as setpoint changes of plant parameters and load demand changes. Various simulations for setpoint and load demand changes of plant performances were conducted to evaluate the modeled fuzzy logic design against the simplified ABWR model control system. The simulation results show that the performance of the fuzzy logic controller is comparable to that of the Proportional-Integral (PI) controller, However, the fuzzy logic controller produced shorter settling time for step setpoint changes compared to the simplified conventional controller

  2. Modeling Caspian Sea water level oscillations under different scenarios of increasing atmospheric carbon dioxide concentrations

    OpenAIRE

    Roshan GholamReza; Moghbel Masumeh; Grab Stefan

    2012-01-01

    Abstract The rapid rise of Caspian Sea water level (about 2.25 meters since 1978) has caused much concern to all five surrounding countries, primarily because flooding has destroyed or damaged buildings and other engineering structures, roads, beaches and farm lands in the coastal zone. Given that climate, and more specifically climate change, is a primary factor influencing oscillations in Caspian Sea water levels, the effect of different climate change scenarios on future Caspian Sea levels...

  3. The level of environmental noise affects the physiological performance of Glycine max under water deficit

    Scientific Electronic Library Online (English)

    Suzana Chiari, Bertolli; Gustavo M., Souza.

    Full Text Available Plants in natural environments are subjected to a multitude of environmental cues. However, studies addressing physiological analyzes are usually focused on the isolation of a stress factor, making it difficult to understand plants behavior in their extremely complex natural environments. Herein, we [...] analyzed how environmental variability (noise) may influence physiological processes of Glycine max under water deficit conditions. The plants were kept in a greenhouse (semi-controlled environment - E SC) and in a growth chamber (controlled environment - E C) under two water regime conditions (100 and 30% of replacement of the water lost by evapotranspiration) for 30 days. The environmental variability was daily monitored with automatic sensors to record temperature, humidity, and irradiance. The physiological responses were analyzed by leaf gas exchanges, chlorophyll fluorescence, biomembrane integrity, and growth parameters. The results showed that water deficiency caused significant reductions in the physiological parameters evaluated. However, the environment with high variability (E SC) caused more extensive damages to biomembranes, regardless the water regime likely compromising physiological efficiency. The lower variability of E C promoted higher efficiency of total biomass production in both water regimes compared to the E SC. Therefore, our results support the hypothesis that more variable environmental conditions can limit the growth of Glycine max in response to the fluctuation of resources, therefore amplifying the effect of water deficit.

  4. An electrical impedance sensor for water level measurements in air–water two-phase stratified flows

    International Nuclear Information System (INIS)

    We report a design of an optimized ring-type impedance sensor for water level measurements in air–water stratified flows through horizontal pipes. The ring-type sensor is optimized in view of the sensor linearity. In order to determine an optimal electrode and gap size of a ring-type sensor which generates a linear relationship between the impedance (resistance and/or reactance) and the water level, systematic numerical calculations are performed, and a ring-type impedance sensor of electrode width-to-diameter ratio 0.25 and gap-to-diameter ratio 0.2 has been selected as optimal. Lab-scale static experiments have been conducted to verify the sensor performance in terms of the linearity. Finally, this proposed sensor is installed in a horizontal loop 40 mm in diameter and roughly 5200 mm in length and measures water levels for various stratified flow conditions. The comparisons of water level measurements between the proposed sensor and the high-speed camera images post-processed by the edge detection scheme show that the maximum deviation in dimensionless water level is roughly 0.037, which corresponds to 1.5 mm over the range 40 mm. (paper)

  5. Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model

    International Nuclear Information System (INIS)

    This Analysis/Model Report (AMR) documents an updated analysis of water-level data performed to provide the saturated-zone, site-scale flow and transport model (CRWMS M and O 2000) with the configuration of the potentiometric surface, target water-level data, and hydraulic gradients for model calibration. The previous analysis was presented in ANL-NBS-HS-000034, Rev 00 ICN 01, Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model (USGS 2001). This analysis is designed to use updated water-level data as the basis for estimating water-level altitudes and the potentiometric surface in the SZ site-scale flow and transport model domain. The objectives of this revision are to develop computer files containing (1) water-level data within the model area (DTN: GS010908312332.002), (2) a table of known vertical head differences (DTN: GS0109083 12332.003), and (3) a potentiometric-surface map (DTN: GS010608312332.001) using an alternate concept from that presented in ANL-NBS-HS-000034, Rev 00 ICN 01 for the area north of Yucca Mountain. The updated water-level data include data obtained from the Nye County Early Warning Drilling Program (EWDP) and data from borehole USW WT-24. In addition to being utilized by the SZ site-scale flow and transport model, the water-level data and potentiometric-surface map contained within this report will be available to other government agencies and water users for ground-water management purposes. The potentiometric surface defines an upper boundary of the site-scale flow model, as well as provides information useful to estimation of the magnitude and direction of lateral ground-water flow within the flow system. Therefore, the analysis documented in this revision is important to SZ flow and transport calculations in support of total system performance assessment

  6. Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model

    Energy Technology Data Exchange (ETDEWEB)

    P. Tucci

    2001-12-20

    This Analysis/Model Report (AMR) documents an updated analysis of water-level data performed to provide the saturated-zone, site-scale flow and transport model (CRWMS M&O 2000) with the configuration of the potentiometric surface, target water-level data, and hydraulic gradients for model calibration. The previous analysis was presented in ANL-NBS-HS-000034, Rev 00 ICN 01, Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model (USGS 2001). This analysis is designed to use updated water-level data as the basis for estimating water-level altitudes and the potentiometric surface in the SZ site-scale flow and transport model domain. The objectives of this revision are to develop computer files containing (1) water-level data within the model area (DTN: GS010908312332.002), (2) a table of known vertical head differences (DTN: GS0109083 12332.003), and (3) a potentiometric-surface map (DTN: GS010608312332.001) using an alternate concept from that presented in ANL-NBS-HS-000034, Rev 00 ICN 01 for the area north of Yucca Mountain. The updated water-level data include data obtained from the Nye County Early Warning Drilling Program (EWDP) and data from borehole USW WT-24. In addition to being utilized by the SZ site-scale flow and transport model, the water-level data and potentiometric-surface map contained within this report will be available to other government agencies and water users for ground-water management purposes. The potentiometric surface defines an upper boundary of the site-scale flow model, as well as provides information useful to estimation of the magnitude and direction of lateral ground-water flow within the flow system. Therefore, the analysis documented in this revision is important to SZ flow and transport calculations in support of total system performance assessment.

  7. The effects of disturbance and severe seasonal fluctuations in environmental conditions on north temperate shallow-water fish assemblages

    Science.gov (United States)

    Nash, Richard D. M.

    1988-02-01

    The shallow-water fish populations at one disturbed and one undisturbed site in the Oslofjord, Norway were sampled with a beach seine from September 1981 to September 1982. The inner site (inner fjord; Hvervenbukta) is in the most polluted part of the fjord and has a heavy recreational usage during the summer months, the outer site (Ellingstad) is in a least polluted part of the fjord and has only sporadic recreational usage. Physical conditions at the two sites differ primarily in seasonal changes of dissolved oxygen levels (Hvervenbukta 3·3-11·1 ml O 2 1 -1 and Ellingstad 5·3-7·1 ml O 2 1 -1). Thirty-three fish species were caught at Ellingstad compared with only 23 at Hvervenbukta, with 0·61 similarity in species lists. Both sites had approximately equal numbers of resident and non-resident species. The mean density of individuals was much greater at Hvervenbukta (0·36 m -2) than at Ellingstad (0·04 m -2). Both sites showed a high dominance factor with a few species comprising the majority of the abundance. Overall species diversity ( H'), evenness ( F') and species richness ( D) were greater at Ellingstad, consistent with the reduced disturbance. The overall range in seasonal similarity was relatively high for both sites as a function of the severe seasonal cycle in temperature (ice cover to approximately 20 °C). These relatively high variations are to be expected for north temperate fish assemblages. The range in the seasonal similarity index was greater at Hvervenbukta reflecting increased disturbance. There were dissimilar patterns in the seasonal cycles of community parameters at the two sites. Changes in population structure were largest during the period of recruitment of new year classes.

  8. Determining return water levels at ungauged coastal sites: a case study for northern Germany

    Science.gov (United States)

    Arns, Arne; Wahl, Thomas; Haigh, Ivan D.; Jensen, Jürgen

    2015-04-01

    We estimate return periods and levels of extreme still water levels for the highly vulnerable and historically and culturally important small marsh islands known as the Halligen, located in the Wadden Sea offshore of the coast of northern Germany. This is a challenging task as only few water level records are available for this region, and they are currently too short to apply traditional extreme value analysis methods. Therefore, we use the Regional Frequency Analysis (RFA) approach. This originates from hydrology but has been used before in several coastal studies and is also currently applied by the local federal administration responsible for coastal protection in the study area. The RFA enables us to indirectly estimate return levels by transferring hydrological information from gauged to related ungauged sites. Our analyses highlight that this methodology has some drawbacks and may over- or underestimate return levels compared to direct analyses using station data. To overcome these issues, we present an alternative approach, combining numerical and statistical models. First, we produced a numerical multidecadal model hindcast of water levels for the entire North Sea. Predicted water levels from the hindcast are bias corrected using the information from the available tide gauge records. Hence, the simulated water levels agree well with the measured water levels at gauged sites. The bias correction is then interpolated spatially to obtain correction functions for the simulated water levels at each coastal and island model grid point in the study area. Using a recommended procedure to conduct extreme value analyses from a companion study, return water levels suitable for coastal infrastructure design are estimated continuously along the entire coastline of the study area, including the offshore islands. A similar methodology can be applied in other regions of the world where tide gauge observations are sparse.

  9. [Effect of external condition on the static migration and release of dibutylphthalate in the soil of the fluctuating zone of the Three Gorges Reservoir to the overlying water].

    Science.gov (United States)

    Song, Jiao-yan; Mu, Zhi-jian; Wang, Qiang; Yang, Zhi-dan; Wang, Fa

    2015-01-01

    In order to understand the environmental behavior of the organic pollutants Dibutyl-phthalate (DBP) in fluctuating zone soil, the migration and release processes of DBP in the fluctuating zone of the Three Gorges Reservoir to the overlying water and the impacts of temperature, light, coexistence phthalate-bis (2-ethylhexyl)-ester (DEHP), microbial activity on the process were studied using static flooding method. The results showed that DBP migrated from the soil to the overlying water in the early days after flooding, and the release process of DBP was divided into two phases: one was the quick release with a relatively short releasing time and a rapid releasing rate; the other was the slow release with a relatively long releasing time and a slow releasing rate. The slow release was a major speed control step, which could be well fitted by two-compartment first-order kinetics. In the interim (12 d) after flooding, the capacity of release reached a maximum, the DBP released from the soil into the water migrated from the water to the soil again after continued flooding, and eventually the content of DBP in soil and water reached equilibrium in the later period after flooding. The intensity of DBP releasing into the overlying water and the rapid releasing rate increased, while the slow releasing rate decreased when the temperature increased. The concentrations of DBP released into the water were different with different light sources. The concentration of DBP in the overlying water with treatment of natural light was higher than those with treatment of ultraviolet light UVB, UVA. After the amount of DBP in the overlying water reached the maximum, the content of DBP in the overlying water decreased relatively faster under the ultraviolet light than under the natural light. The largest release content of DBP and the time reached the largest release content were different with different oxygen content in the overlying water. Overall, the higher oxygen content in the overlying water, the higher content of DBP in the overlying water. The time when the concentration of DBP in overlying water reached the maximum was on the 8th day after flooding in the high oxygen and low oxygen studies, while the time was on the 12th day in natural study. When the phthalate-bis (2-ethylhexyl)-ester(DEHP) co-existed in the soil, there would be some significant influence on the release of DBP. After DEHP addition in the soil, it could release more DBP than the control, and both the rapid releasing rate and slow releasing rate were bigger than those of the control. The microbial activity had some impacts on the process. However, the effect was not obvious. After adding microbial activity inhibitor, the content of migrated DBP was slightly lower than that of the control. PMID:25898658

  10. Seven years of external control of fluoride levels in the public water supply in Bauru, Sao Paulo, Brazil

    Scientific Electronic Library Online (English)

    Marilia Afonso Rabelo, BUZALAF; Camila Mascarenhas, MORAES; Kelly Polido Kaneshiro, OLYMPIO; Juliano Pelim, PESSAN; Larissa Tercilia, GRIZZO; Thelma Lopes, SILVA; Ana Carolina, MAGALHAES; Rodrigo Cardoso de, OLIVEIRA; Sonia, GROISMAN; Irene, RAMIRES.

    2013-01-01

    Full Text Available Fluoridation of the public water supplies is recognized as among the top ten public health achievements of the twentieth century. However, the positive aspects of this measure depend on the maintenance of fluoride concentrations within adequate levels. Objective To report the results of seven years [...] of external control of the fluoride (F) concentrations in the public water supply in Bauru, SP, Brazil in an attempt to verify, on the basis of risk/benefit balance, whether the levels are appropriate. Material and Methods From March 2004 to February 2011, 60 samples were collected every month from the 19 supply sectors of the city, totaling 4,641 samples. F concentrations in water samples were determined in duplicate, using an ion-specific electrode (Orion 9609) coupled to a potentiometer after buffering with TISAB II. After the analysis, the samples were classified according to the best risk-benefit adjustment. Results Means (±standard deviation) of F concentrations ranged between 0.73±0.06 and 0.81±0.10 mg/L for the different sectors during the seven years. The individual values ranged between 0.03 and 2.63 mg/L. The percentages of the samples considered “low risk” for dental fluorosis development and of “maximum benefit” for dental caries prevention (0.55-0.84 mg F/L) in the first, second, third, fourth, fifth, sixth, and seventh years of the study were 82.0, 58.5, 37.4, 61.0, 89.9, 77.3, and 72.4%, respectively, and 69.0% for the entire period. Conclusions Fluctuations of F levels were found in the public water supply in Bauru during the seven years of evaluation. These results suggest that external monitoring of water fluoridation by an independent assessor should be implemented in cities where there is adjusted fluoridation. This measure should be continued in order to verify that fluoride levels are suitable and, if not, to provide support for the appropriate adjustments.

  11. Performance assessment for the water level control system in steam generator of the nuclear power plant

    International Nuclear Information System (INIS)

    Highlights: ? We consider the two PI controller steam generator water level control systems. ? We develop performance assessment methods for plants with stable and unstable zeros. ? The examples show the effectiveness of the proposed method. - Abstract: The steam generator water level control system is the most important components of a nuclear power plant. The operating steam generator water level control system is increasingly recognized as a capital asset that should be routinely maintained and monitored. However, the control loop performance assessment is still an open problem; thus, the performance assessment technology will be brought into the steam generator water level control system in nuclear power plants. Performance assessment methods for the plant with stable and unstable zeros of two PI controller systems are developed at all specific power levels. The numerical examples will demonstrate the effectiveness of the proposed method.

  12. Origin of elevated water levels encountered in Pahute Mesa emplacement boreholes: Preliminary investigations

    International Nuclear Information System (INIS)

    The presence of standing water well above the predicted water table in emplacement boreholes on Pahute Mesa has been a recurring phenomenon at the Nevada Test Site (NTS). If these levels represent naturally perched aquifers, they may indicate a radionuclide migration hazard. In any case, they can pose engineering problems in the performance of underground nuclear tests. The origin of these elevated waters is uncertain. Large volumes of water are introduced during emplacement drilling, providing ample source for artificially perched water, yet elevated water levels can remain constant for years, suggesting a natural origin instead. In an effort to address the issue of unexpected standing water in emplacement boreholes, three different sites were investigated in Area 19 on Pahute Mesa by Desert Research Institute (DRI) staff from 1990-93. These sites were U-19az, U-19ba, and U-19bh. As of this writing, U-19bh remains available for access; however, nuclear tests were conducted at the former two locations subsequent to this investigations. The experiments are discussed in chronological order. Taken together, the experiments indicate that standing water in Pahute Mesa emplacement holes originates from the drainage of small-volume naturally perched zones. In the final study, the fluids used during drilling of the bottom 100 m of emplacement borehole U-19bh were labeled with a chemical tracer. After hole completion, water level rose in the borehole, while tracer concentration decreased. In fact, total mass of tracer in the borehole remained constant, while water levels rose. After water levels stabilized in this hole, no change in tracer mass was observed over two years, indicating that no movement of water out of the borehole is taking place (as at U- 19ba). Continued labeling tests of standing water are recommended to confirm the conclusions made here, and to establish their validity throughout Pahute Mesa

  13. DATA QUALIFICATION REPORT: WATER-LEVEL DATA FROM THE NYE COUNTY EARLY WARNING DRILLING PROGRAM

    International Nuclear Information System (INIS)

    The objective of this work is to evaluate unqualified, water-level data gathered under the Nye County Early Warning Drilling Program (EWDP) and to determine whether the status of the data should be changed to ''qualified'' data in accordance with AP-SIII.2Q (Qualification of Unqualified Data and the Documentation of Rationale for Accepted Data). The corroboration method (as defined in Attachment 2 of AP-SIII.2Q) was implemented to qualify water-level data from Nye County measurements obtained directly from the Nye County Nuclear Waste Repository Program Office (NWRPO). Comparison of United States Geological Survey (USGS) measurements contained in DTN GS990608312312.003 with the Nye County water-level data has shown that the differences in water-level altitudes for the same wells are significantly less than 1 meter. This is an acceptable finding. Evaluation and recommendation criteria have been strictly applied to qualify Nye County measurements of water levels in selected wells measured by the USGS. However, the process of qualifying measured results by corroboration also builds confidence that the Nye County method for measurement of water levels is adequate for the intended use of the data (which is regional modeling). Therefore, it is reasonable to extend the term of ''qualified'' to water-level measurements in the remaining Nye County Phase I wells on the basis that the method has been shown to produce adequate results for the intended purpose of supporting large-scale modeling activities for the Yucca Mountain Project (YMP). The Data Qualification Team recommends the Nye County, water-level data contained in Appendix D of this report be designated as ''qualified''. These data document manual measurements of water-levels in eight (8) EWDP Phase I drillholes that were obtained prior to the field installation of continuous monitoring equipment

  14. X-ray radiographic experimental investigation of the reference level in hydrostatic level measurement systems for boiling water reactors

    International Nuclear Information System (INIS)

    Hydrostatic level control is of high priority for normal operation safety of BWR-type reactors. For the prevention of undershooting the limiting values precise and secure measuring techniques are indispensable. Actually the filling level is determined form the hydrostatic pressure difference to a reference column. For the secure non-invasive detection of the phase boundary water/steam in inclined tubes the X-ray radiography has been chosen. The experiments were aimed to study possible geometric influences on the water/steam phase boundary. It was shown that the reference filling level is not significantly changed in spite of permanent phase transitions, provided an ideal mechanical construction of the system is given. Future experiments shall be focused on the analysis of interface behavior in case of non-ideal geometries (welds).

  15. Fluctuating micro-heterogeneity in water - tert-butyl alcohol mixtures and lambda-type divergence of the mean cluster size with phase transition-like multiple anomalies

    CERN Document Server

    Banerjee, Saikat; Bagchi, Biman

    2014-01-01

    Water - tert-butyl alcohol (TBA) binary mixture exhibits a large number of thermodynamic and dynamic anomalies. These anomalies are observed at surprisingly low TBA mole fraction, with $x_{\\text{TBA}} \\approx 0.03 - 0.07$. We demonstrate here that the origin of the anomalies lies in the local structural changes that occur due to self-aggregation of TBA molecules. We observe a percolation transition of the TBA molecules at $x_{\\text{TBA}} \\approx 0.05$. We note that "islands" of TBA clusters form even below this mole fraction, while a large spanning cluster emerges above that mole fraction. At this percolation threshold, we observe a lambda-type divergence in the fluctuation of the size of the largest TBA cluster, reminiscent of a critical point. Alongside, the structure of water is also perturbed, albeit weakly, by the aggregation of TBA molecules. There is a monotonic decrease in the tetrahedral order parameter of water, while the dipole moment correlation shows a weak non-linearity. Interestingly, water mol...

  16. Radar Based Flow and Water Level Forecasting in Sewer Systems : a danisk case study

    DEFF Research Database (Denmark)

    Thorndahl, SØren; Rasmussen, Michael R.

    2009-01-01

    This paper describes the first radar based forecast of flow and/or water level in sewer systems in Denmark. The rainfall is successfully forecasted with a lead time of 1-2 hours, and flow/levels are forecasted an additional ½-1½ hours using models describing the behaviour of the sewer system. Both radar data and flow/water level model are continuously updated using online rain gauges and online in-sewer measurements, in order to make the best possible predictions. The project show very promising results, and show large potentials, exploiting the existing water infrastructure in future climate changes.

  17. Development and application of YSJ-1 type oil-water interface level gauge

    International Nuclear Information System (INIS)

    A new type nuclear device for measuring the oil-water interface level as well as the total liquid level was presented. A series of new methods, such as non-linear fitting of the level, automatic compensations for the deviation caused by the decay of radioactive source, the medium's temperature, etc., were employed. Comparing with other non-nuclear techniques, this device has the following advantages: non-contact surveying, anti-interference of paraffin wax coagulating and a little of repairing. The measuring range is 0-200cm for total liquid level and 0-100cm for oil-water interface level respectively. The measurement precision is 1% for total liquid level and 2% for the interface level respectively. The respond time is ?10s, the long time stability ?0.5% FS/48h and the temperature influence ?0.01% FS /degree C. The gauge can be used in surveying oil-water interface level and total liquid level in oil-water separation tanks on oil fields. It is also suitable to measure the interface level of two kinds of liquids as well as the total liquid level in various storage tanks

  18. Fluctuation phenomena

    International Nuclear Information System (INIS)

    Fluctuation phenomena are the ''tip of the iceberg'' revealing the existence, behind even the most quiescent appearing macroscopic states, of an underlying world of agitated, ever-changing microscopic processes. While the presence of these fluctuations can be ignored in some cases, e.g. if one is satisfied with purely thermostatic description of systems in equilibrium, they are central to the understanding of other phenomena, e.g. the nucleation of a new phase following the quenching of a system into the co-existence region. This volume contains a collection of review articles, written by experts in the field, on the subject of fluctuation phenomena. Some of the articles are of a very general nature discussing the modern mathematical formulation of the problems involved, while other articles deal with specific topics such as kinetics of phase transitions and conductivity in solids. The juxtaposition of the variety of physical situations in which fluctuation phenomena play an important role is novel and should give the reader an insight into this subject

  19. Recent reduction in the water level of Lake Victoria has created more habitats for Anopheles funestus

    Directory of Open Access Journals (Sweden)

    Futami Kyoko

    2008-07-01

    Full Text Available Abstract Background The water level of Lake Victoria has fallen more than 1.5 m since 1998, revealing a narrow strip of land along the shore. This study determined whether the recent drop in the water level has created additional breeding grounds for malaria vectors. Methods The recent and past shorelines were estimated using landmarks and a satellite image. The locations of breeding habitats were recorded using a GPS unit during the high and low lake water periods. GIS was used to determine whether the breeding habitats were located on newly emerged land between the new and old shorelines. Results Over half of the breeding habitats existed on newly emerged land. Fewer habitats for the Anopheles gambiae complex were found during the low water level period compared to the high water period. However, more habitats for Anopheles funestus were found during the high water level period, and they were all located on the newly emerged land. Conclusion The recent reduction in water level of Lake Victoria has increased the amount of available habitat for A. funestus. The results suggest that the water drop has substantially affected the population of this malaria vector in the Lake Victoria basin, particularly because the lake has a long shoreline that may harbour many new breeding habitats.

  20. Spectral fluctuation dividing for efficient wavenumber selection: application to estimation of water and drug content in granules using near infrared spectroscopy.

    Science.gov (United States)

    Miyano, Takuya; Kano, Manabu; Tanabe, Hideaki; Nakagawa, Hiroshi; Watanabe, Tomoyuki; Minami, Hidemi

    2014-11-20

    In process analytical technology (PAT) based on near infrared (NIR) spectroscopy, wavenumber selection is crucial to develop an accurate and robust calibration model. The present research proposes new efficient spectral dividing and wavenumber selection methods to significantly reduce the computational load required by conventional wavenumber selection methods such as interval partial least squares (iPLS). The proposed method, named spectral fluctuation dividing (SFD), divides a whole spectrum into multiple spectral intervals at local minimum points of the spectral fluctuation profile, which consists of the standard deviation of absorbance at each wavenumber in a calibration set. SFD is combined with PLS (SFD-PLS) to select the spectral intervals at which input variables have significant influence on a target response. The usefulness of SFD-PLS was demonstrated through its application to the problems of estimating water and drug content in granules. PLS models based on SFD-PLS achieved higher estimation accuracy than those based on conventional methods including iPLS, PLS-beta, and variable influence on projection (VIP). In addition, SFD-PLS was more than 10 times faster than the conventional variable selection methods including PLS-beta and VIP; in particular, SFD-PLS was more than 25 times faster than iPLS. Consequently, the proposed SFD-PLS is a promising wavenumber selection method. PMID:25218183

  1. Estimation method of water level behavior in the case of large pressure change in a BWR

    International Nuclear Information System (INIS)

    In a BWR, coolant of core and upper plenum involves so much void volume that free surface level change at downcomer is conspicuous owing to increase and decrease of void volume influenced by pressure change. When mass balance in a reactor vessel becomes non-equilibrium due to steam valve stuck open or feedwater pump trip, difference between liquid level and mixture level becomes very large because of void increased due to depressurization. Therefore, it is very difficult to estimate changes in water level after void exclusion by isolation valve closure etc. So a new parameter ''effective increased void volume'' was contrived to estimate water level in the occurrance of above mentioned phenomena, as a result of consideration about relation between discharged mass and reactor pressure. Degree of water level change under initial operating conditions and reactor pressure change can be estimated by using this parameter. (author)

  2. Flutuação populacional e intensidade de infestação da broca-dos-frutos em cupuaçu / Population fluctuation and infestation levels of the cupuaçu fruit borer

    Scientific Electronic Library Online (English)

    Marcílio José, Thomazini.

    2002-09-01

    Full Text Available Dentre as pragas do cupuaçueiro Theobroma grandiflorum (Wild. ex Spreng.) Schum., a broca-dos-frutos, Conotrachelus humeropictus Fiedler (Coleoptera: Curculionidae), é a mais importante, devido aos danos causados e por estar disseminada em alguns Estados da região Norte do Brasil. Os objetivos deste [...] trabalho foram avaliar a flutuação populacional de adultos de C. humeropictus, determinar a intensidade de infestação e caracterizar o ataque de larvas desta praga em frutos de cupuaçueiros, em sistemas agroflorestais no Estado de Rondônia. Para obter a flutuação populacional de adultos da broca, foram amostradas semanalmente, durante o período de março/98 a julho/00, 20 plantas de cupuaçu, pelo método do sacolejo, em duas áreas de agrossilvicultores. A avaliação da população de larvas foi realizada durante duas safras, onde foram coletados e abertos frutos atacados pela broca. A determinação da infestação da praga foi obtida através da porcentagem de frutos broqueados. Adultos de C. humeropictus ocorrem durante todo ano nas plantas de cupuaçu, na área estudada, mas predominam na floração, início da frutificação e durante o período de safra. Tanto os frutos verdes como os maduros são atacados, sendo que larvas de idades diferentes podem ocorrem em um mesmo fruto. Perdas superiores a 50% na produção de frutos, devido ao ataque da broca, ressaltam a importância desta praga na região. Abstract in english The most important pest of the cupuaçu crop is the fruit borer, Conotrachelus humeropictus Fiedler (Coleoptera: Curculionidae), wich severely damages fruits and is disseminated all over North Brazil. The objectives of this study were evaluating the population fluctuations of C. humeropictus adults, [...] infestation levels and to characterize the pest larval attack in cupuaçu fruits of agroforestry systems of the Rondonia State, Brazil. Population fluctuations from C. humeropictus adults were evaluated weekly from March/98 to July/00 in twenty cupuaçu plants, by shaking the tree branches, of two producer areas. During two harvest periods, fruits attacked by the borer were collected and examined for evaluation of larvae population. Pest infestation was determined by the percentage of damaged fruits. C. humeropictus adults occur year around on cupuaçu plants, but predominate at the stages of flowering, fruit formation and during the harvest period. It was observed that mature and non-mature fruits are attacked by the pest; larvae of different ages can occur in a same fruit; the insect may cause losses greater than 50% of fruit yield.

  3. Structured singular value synthesis based steam generator water level controller design

    International Nuclear Information System (INIS)

    An uncertainty kinetic model for valve position of feed water to steam generator water level plant was built which can express parameter perturbation and unmodeled dynamic due to operation condition change of steam generator and feed water pump. Robust controller was designed based on structured singular value synthesis method. Robust stability of the water control system can be guaranteed under parameter perturbation and unmodeled dynamic, and robust performance can be acquired via suitable performance weight function. Simulation results show that good control performances are obtained under all combinations of steam generator operation condition and feed water pump operation condition. (authors)

  4. Understanding the connection of extreme water levels to mortality in the megacity Dhaka

    Science.gov (United States)

    Thiele-Eich, Insa; Burkart, Katrin; Simmer, Clemens

    2015-04-01

    To quantitatively assess the impact of extreme water levels on a local scale we study both low and high water levels and their connection to mortality in the megacity Dhaka. Dhaka is currently threatened by a range of natural hazards such as earth quakes, tropical cyclones and - on an almost annual basis - flooding . Flooding in the megacity is largely determined by the close proximity to the confluence of the Ganges and Brahmaputra rivers upstream as well as the conjunction with the Meghna river further downstream. The risk of flooding is aggravated through rapid urbanization and concurrent encroachment on retention areas, as well as increasing problems with both the natural and man-made drainage system. A growing population, continuing urbanization and climate change are all expected to worsen the situation in Dhaka. This prompted us to study historical trends in extreme water levels using over 100 years of daily water level data with respect to trends in frequency, magnitude and duration, focusing on rare but particularly high-risk events using extreme-value theory. In a further step, the complex link between water levels and mortality are studied using a distributed lag non-linear model with mortality data available on a daily basis for a five-year period (2003-2007). Our analysis suggests that water levels have indeed changed over the course of the past century. While the magnitude and duration of average flood events decreased, the frequency of extreme flood events has increased. Low water levels have also changed, with a significant decrease in the annual minimum water level when comparing the time periods 1909-1939 and 1979-2009. Results further indicate that for the period of 2003-2007, which entails two major flood events in 2004 and 2007, high water levels do not lead to a significant increase in relative mortality, which indicates a good level of adaptation and capacity to cope with flooding. However, following low water levels, an increase in mortality could be found. This is particularly alarming as low water levels have continuously decreased over the past 100 years. Thus, to ensure the population is capable of coping with future climate change, we stress the importance of not only continuing and improving the current adaptation measures for flooding, but to also prepare the population for drought events.

  5. Influence of tidal fluctuations in the water table and methods applied in the calculation of hydrogeological parameters. The case of Motril-Salobreña coastal aquifer

    Science.gov (United States)

    Sánchez Úbeda, Juan Pedro; Calvache Quesada, María Luisa; Duque Calvache, Carlos; López Chicano, Manuel; Martín Rosales, Wenceslao

    2013-04-01

    The hydraulic properties of coastal aquifer are essential for any estimation of groundwater flow with simple calculations or modelling techniques. Usually the application of slug test or tracers test are the techniques selected for solving the uncertainties. Other methods are based on the information associated to the changes induced by tidal fluctuation in coastal zones. The Tidal Response Method is a simple technique based in two different factors, tidal efficiency factor and time lag of the tidal oscillation regarding to hydraulic head oscillation caused into the aquifer. This method was described for a homogeneous and isotropic confined aquifer; however, it's applicable to unconfined aquifers when the ratio of maximum water table fluctuation and the saturated aquifer thickness is less than 0.02. Moreover, the tidal equations assume that the tidal signal follows a sinusoidal wave, but actually, the tidal wave is a set of simple harmonic components. Due to this, another methods based in the Fourier series have been applied in earlier studies trying to describe the tidal wave. Nevertheless, the Tidal Response Method represents an acceptable and useful technique in the Motril-Salobreña coastal aquifer. From recently hydraulic head data sets at discharge zone of the Motril-Salobreña aquifer have been calculated transmissivity values using different methods based in the tidal fluctuations and its effects on the hydraulic head. The effects of the tidal oscillation are detected in two boreholes of 132 m and 38 m depth located 300 m to the coastline. The main difficulties for the application of the method were the consideration of a confined aquifer and the variation of the effect at different depths (that is not included into the tidal equations), but these troubles were solved. In one hand, the assumption that the storage coefficient (S) in this unconfined aquifer is close to confined aquifers values due to the hydrogeological conditions at high depth and without saturation changes. In the other hand, we have monitored hydraulic head fluctuations due to tidal oscillations in different shallow boreholes close to the shoreline, and comparing with the deep ones. The calculated values with the tidal efficiency factor in the deep boreholes are about one less order of magnitude regarding to the obtained results with time lag method. Nevertheless, the application of these calculation methods based on tidal response in unconfined aquifers provides knowledge about the characteristics of the discharge zone and groundwater flow patterns, and it may be an easy and profitable alternative to traditional pumping tests.

  6. Hydraulic modeling of a mixed water level control hydro-mechanical gate

    OpenAIRE

    Cassan, L.; Baume, J-P.; Belaud, G.; Litrico, X.; Malaterre, P-O.; Ribot-Bruno, J.

    2011-01-01

    The article describes the hydraulic functioning of a mixed water level control hydromechanical gate present in several irrigation canals. According to the flow conditions, this automatic gate maintains the upstream level close to a target value for low flow, then it controls the downstream level close to a target, and switches back to control the upstream level to avoid overflow. Such a complex behaviour is obtained via a series of side tanks linked by orifices and weirs. We analyze this beha...

  7. Historical impact of water infrastructure on water levels of the Mekong River and the Tonle Sap System

    OpenAIRE

    T. A. Cochrane; M. E Arias; Piman, T.

    2014-01-01

    The rapid rate of water infrastructure development in the Mekong basin is a cause for concern due to its potential impact on fisheries and downstream natural ecosystems. In this paper we analyse the historical water levels of the Mekong River and Tonle Sap system by comparing pre and post 1991 daily observations from six stations along the Mekong mainstream from Chiang Sean (northern Laos), to Stung Treng (Cambodia), and the Prek Kdam station on the Tonle Sa...

  8. HIRDLS/Aura Level 3 Water Vapor (H2O) Zonal Fourier Coefficients V007

    Data.gov (United States)

    National Aeronautics and Space Administration — The "HIRDLS/Aura Level 3 Water Vapor (H2O) Zonal Fourier Coefficients" version 7 data product (H3ZFCH2O) contains the entire mission (~3 years) of HIRDLS data...

  9. Great Lakes Daily Ice Observations at NOAA Water Level Gauge Sites

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains daily visual ice observations taken yearly from 1 November to 30 April at NOAA/National Ocean Service water level gauge sites in the Great...

  10. Nimbus-6/SCAMS Level 2 Water Vapor and Temperature V001

    Data.gov (United States)

    National Aeronautics and Space Administration — The Nimbus-6 Scanning Microwave Spectrometer (SCAMS) Level 2 data product contains water vapor and temperature profiles. The SCAMS was designed to map tropospheric...

  11. Potentiometric water-level altitude contours of Dixie Valley, west-central Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set contains the potentiometric water-level altitude contours representing the 2009 potentiometric surface of the basin fill groundwater system of Dixie...

  12. Quantitative Assay and Evaluation of Uranium Levels in Water Resources of Egypt

    International Nuclear Information System (INIS)

    Quality of water resources are one of the vital components for industrial, agricultural and economical development as well as for security issue. The aim of this study is to evaluate the levels of uranium in the Egyptian water resources used for drinking purposes. Fifty-seven water samples representing Egyptian water resources for drinking water (unpurified, purified, tap and ground) were collected. Sensitive and rapid destructive laser fluorimetry technique was used for uranium determination. The results showed that the level of uranium in most of the collected samples was below than the safe limit recommended by the international organizations. The average annual equivalent dose due to the consumption of water ranged from 0.1 ?Sv/y to 2.0 ?Sv/y which is lower than the international recommendation

  13. Effects of chlorine level on the growth of biofilm in water pipes.

    Science.gov (United States)

    Chu, Chenghwa; Lu, Chungsying; Lee, Chimei; Tsai, Changhsieu

    2003-07-01

    Three analogous laboratory-scale water pipe systems were constructed to study the effects of three chlorine levels of finished water on the growth of biofilm. The experimental results indicated that the heterotrophic plate counts (HPCs) of biofilm for chlorine-free water were approximately 2 and 3 orders of magnitude higher than those for low-chlorine water (0.3-0.5mg Cl2/L) and high-chlorine water (1.2-1.5mg Cl2/L). The difference in HPC levels between low-chlorine water and high-chlorine water was below 1 order. Average biofilm formation rates are 325 ATP pg/cm2-day for chlorine-free water, 159 ATP pg/cm2-day for low-chlorine water and 118 ATP pg/cm2-day for high-chlorine water. The scanning electron microscope (SEM) observation showed that bacterial species separated from the biofilm were more complex than from the finished water. The Gram-negative bacteria were dominant in these species. PMID:12916858

  14. PERSISTENT HIGH WATER LEVELS AROUND ANDAMAN & NICOBAR ISLANDS FOLLOWING THE 26 DECEMBER 2004 TSUNAMI

    OpenAIRE

    Rao, A.D.; Nistor, I.; T. S. Murty; N. Nirupama

    2006-01-01

    During the tsunami of 26th December 2004 in the Indian Ocean, media reports suggested that high water levels persisted around the Andaman & Nicobar Islands for several days. These persistent high water levels can be explained by invoking the existence of trapped and partially leaky modes on the shelves surrounding these islands. It has been known in the studies of tides in the global oceans, that there are two distinct types of oscillations, separated in their frequencies by the period of the...

  15. Water level forecasting through fuzzy logic and artificial neural network approaches

    OpenAIRE

    Alvisi, S.; Mascellani, G.; Franchini, M.; A. Bárdossy

    2005-01-01

    In this study three data-driven water level forecasting models are presented and discussed. One is based on the artificial neural networks approach, while the other two are based on the Mamdani and the Takagi-Sugeno fuzzy logic approaches, respectively. All of them are parameterised with reference to flood events alone, where water levels are higher than a selected threshold. The analysis of the three models is performed by using the same input and output variables. However, in order to eval...

  16. Assessing the effect of different river water level interpolation schemes on modeled groundwater residence times

    OpenAIRE

    Diem, Samuel; Renard, Philippe; Schirmer, Mario

    2015-01-01

    Obtaining a quantitative understanding of river–groundwater interactions is of high practical relevance, for instance within the context of riverbank filtration and river restoration. Modeling interactions between river and groundwater requires knowledge of the river’s spatiotemporal water level distribution. The dynamic nature of riverbed morphology in restored river reaches might result in complex river water level distributions, including disconnected river branches, nonlinear longitudinal...

  17. Effects of radiation heat transfer for prediction of water temperature and level in spent fuel pit

    International Nuclear Information System (INIS)

    In order to predict water temperature of the spent fuel pit (SFP) of nuclear power plants after shutdown of its cooling systems, a prediction system with a one-region model was developed based on three-dimensional (3D) thermal-hydraulic behavior calculated by using the CFD software, FLUENT 6.3.26. In the prediction system, decay heat calculated by using the burn-up calculation software, ORIGEN 2.2, and the previously proposed correlation for evaporation heat fluxes from the water surface to air were used. The prediction system was extended to calculate water temperature and level during loss of all AC power supplies under natural convection of air flow and the calculated results were verified using measured values from the Fukushima Daiichi Nuclear Power Station. This prediction system was introduced a conservative heat transfer model which ignored radiation heat fluxes that contained uncertain emissivity. Therefore, in this, study, we used a non-conservative heat transfer model including radiation heat fluxes with relatively large emissivity and we calculated effects of radiation heat fluxes on the water temperature and level to investigate uncertainties of the prediction system. As a result, we found radiation heat fluxes affected the decreasing rate of the water level but did not directly affect the water temperature. Then we did sensitivity calculations to obtain decay heat and evaporation heat flux which gave good agreement with the measured decreasing rate of the water level and water temperature, respectively. (author)

  18. Determination of Trace Level Triclosan in Water by Online Preconcentration and HPLC-UV Diode Array

    Science.gov (United States)

    An online high performance liquid chromatography (HPLC) method for the detection and quantification of trace levels of triclosan in water is discussed. Triclosan, an anti-bacterial agent, and related compounds have been shown to reach municipal waste waters through the disposal ...

  19. Contested water rights in post-apartheid South Africa: the struggle for water at catchment level

    Scientific Electronic Library Online (English)

    JS, Kemerink; R, Ahlers; P, van der Zaag.

    2011-10-01

    Full Text Available The National Water Act (1998) of South Africa provides strong tools to redress inequities inherited from the past. However, a decade after the introduction of the Act, access to water is still skewed along racial lines. This paper analyses the various ways in which the Water Act is contested, based [...] on empirical data detailing the interactions between smallholder farmers and commercial farmers in a case-study catchment in KwaZulu-Natal Province. The paper argues that the legacy of the apartheid era still dominates the current political and economical reality and shows how the redistribution of water resources is contested by the elite. The paper identifies several issues that prevent the smallholder farmers from claiming their rights, including the institutional arrangements in former homelands, the 'community approach' of Government and NGOs, the disconnect between land and water reform processes, and historically-entrenched forms of behaviour of the various actors. The paper concludes that the difficulties encountered in the water reform process are illustrative for what is happening in the society at large and raises the question as to what price is being paid to maintain the current status quo in the division of wealth?

  20. Isotope studies of water dynamics. Implications of the rise of the Caspian Sea level

    International Nuclear Information System (INIS)

    After more than 40 years of continuous decline, since 1978 the Caspian Sea level has been rising and at the end of 1994 it was nearly 2.5 m above the 1978 level. The nature and the mechanism of perpetual sea level variations are unknown. But in this particular case it was observed that the sea level is accompanied by an increase of river runoff from the catchment area and a decrease of evaporation from the sea surface. In order to understand the implications of the sea level rise isotope studies of water dynamics were undertaken by periodical sampling of sea, river and precipitation water. By comparison of oxygen isotopes and salinity distribution it was found that the pattern of the river and sea water mixing is changing. The residence time of water masses of the North Caspian Sea and the main water balance characteristics were determined using oxygen isotope salinity analysis. The problem of vertical mixing processes of cold bottom and warm surface water in the middle and the southern depression was studied using tritium data from sampling cruises in 1983, 1991 and 1994. Owing to an increase of the river runoff the cold bottom water rise was intensified. Consequently the surface layer temperature dropped and evaporation decreased. This feedback effect of water dynamics on sea level variation was derived from the study. Quasi-periodic hydrotroilite layers in the sea bottom core sediments were discovered. Preliminary isotope and chemical analyses show that the hydrotroilite (FeS·nH2O) is a promising indicator of sea level variation in the past. (author). 5 refs, 6 figs, 2 tabs

  1. Paleohydrology of the southern Great Basin, with special reference to water table fluctuations beneath the Nevada Test Site during the Late Pleistocene

    International Nuclear Information System (INIS)

    The magnitude of water table rise during Pleistocene pluvial climates, and of the resultant shortening of ground-water flow path and reduction in unsaturated zone thickness, is investigated. The distribution of calcitic veins in alluvium and lakebeds, and of tufa deposits, between the Ash Meadows spring discharge area and the Nevada Test Site suggests that discharge from the regional Paleozoic carbonate aquifer during the Late Pleistocene occurred at distances as much as 14 kilometers northeast of Ash Meadows and at altitudes up to 50 meters higher than at present. Use of the underflow equation (relating discharge to transmissivity, aquifer width, and hydraulic gradient), and various assumptions regarding pluvial recharge, transmissivity, and altitude of ground-water base level, suggest possible rises in potentiometric level in the carbonate aquifer of 6 to 90 meters beneath central Frenchman Flat, 58 kilometers northeast of Ash Meadows. During Wisconsin time the rise probably did not exceed 30 meters. Water-level rises beneath Frenchman Flat during future pluvials are unlikely to exceed 30 meters, and future levels might even be 10 meters lower than the modern one, 210 meters beneath the center of the valley. Neither the cited rise in potentiometric level in the regional carbonate aquifer, nor the shortened flow path during the Late Pleistocene precludes utilization of the NTS as a repository for high-level or transuranic-element radioactive wastes provided other requisite conditions are met at this site. Deep water tables, attendant thick (up to several hundred meter) unsaturated zones, and ground-water flow paths tens of kilometers in length characterized the region during Wisconsin time and possibly throughout the Pleistocene, and are likely to so characterize it during future pluvial climates

  2. Elevación máxima del agua en la laguna Mar Chiquita, Córdoba, Argentina / Maximum Water Level in Mar Chiquita, Lagoon, Cordoba, Argentina

    Scientific Electronic Library Online (English)

    Mariana, Pagot; Gerardo, Hillman; Cecilia, Pozzi-Piacenza; Paolo, Gyssels; Antoine, Patalano; Andrés, Rodriguez.

    2014-08-01

    Full Text Available La laguna Mar Chiquita es el mayor cuerpo de agua endorreico de la República Argentina y está ubicada al noreste de la provincia de Córdoba. El nivel de agua máximo es objeto de este trabajo y se definió con base en el efecto combinado del máximo nivel de agua histórico medido sobre la costa sur y d [...] e la máxima sobre-elevación por tormenta estimado para recurrencias de 25, 50 y 100 años. El análisis de las series de niveles de agua permitió definir el valor máximo histórico del nivel medido en la laguna. Este valor se registró en el año 2003 con una cota de 71.9 m sobre nivel del mar (snm). La máxima sobre-elevación por tormenta se definió por la acción conjunta del viento y del oleaje generado por el mismo. Para estas estimaciones se utilizaron programas específicos y formulaciones empíricas. Para propagar el oleaje sobre el perfil de playa, se reconstruyó la batimetría de la laguna, basada en técnicas de teledetección. A tal efecto se utilizaron datos de elevación del terreno, tomando relevamientos espaciales con radar y mapas temáticos derivados de imágenes satelitales ópticas, productos LandSat, basados en el proceso de extracción digital de los contornos de agua. Los resultados indicaron que la cota máxima de inundación de la laguna Mar Chiquita para la costa sur del sistema podría llegar a los 73.5 msnm para una recurrencia de 100 años. Este análisis es importante realizarlo en sistemas que presentan grandes fluctuaciones del nivel de agua, como el aquí presentado. Abstract in english Mar Chiquita lagoon is the largest endorheic body of water in Argentina. It is located in the northeast portion of the province of Cordoba. The maximum water level is the topic of this work, which is defined using the combined effect of the historical maximum water level measured on the coast and th [...] e maximum storm elevation (considering both wind and waves) estimated for recurrences of 25, 50 and 100 years. The analysis of the series of water levels made it possible to determine the historical maximum level measured in the lagoon. This value was recorded in 2003 as a height of 71.9 meters above sea level (masl). The maximum storm level is defined by both the action of the wind and waves generated by the storm. Specific software and empirical formulas were used to obtain these estimates. To propagate the waves on the beach profile, the bathymetry of the lagoon was rebuilt using remote sensing techniques. To this end, terrain elevation data were used from space surveys derived from radar and from thematic maps based on Landsat images with the digital extraction of water contours. The results indicate that the maximum flood that could occur in Laguna Mar Chiquita, on the southern coast of the system, is 73.5 masl with a recurrence of 100 years. It is important to conduct this analysis for systems with large fluctuations in water levels, such as the one presented here.

  3. A case study on the effect of water from groundwater sources on indoor radon levels

    International Nuclear Information System (INIS)

    Indoor airborne radon concentration released from water was estimated over several months based on experimental measurements. When heated water including radon was used, the radon level became high in the entire house. Filling the bathtub with hot water had a strong effect on the indoor radon level. In winter, the indoor radon concentration was high due to windows being closed. The radon transfer coefficient was estimated 2.5 x 10-4 in this test house. This is 2.5 times higher than the average radon transfer efficiency estimated by UNSCEAR. (author)

  4. TIME SERIES METHODS FOR WATER LEVEL FORECASTING OF DUNGUN RIVER IN TERENGGANU MALAYSIA

    Directory of Open Access Journals (Sweden)

    SITI HAJAR ARBAIN

    2012-04-01

    Full Text Available Due to climate change and global warming, the possibility of floods may increase to occur in Malaysia. Water level forecasting are important for the water catchment management in particular for flood warning systems. The aim of this study is to predict water level with input variables monthly rainfall and rate of evaporation takenfrom the same catchment at Dungun River, Terengganu-Malaysia, using ARIMA and Artificial Neural Network (ANN. The process of pre-processing data has been made to the original rainfall data since they contain imperfect characteristics data. Our experiments show that the ANN with cleansing rainfall data gives better performance than ARIMA and ANN without cleansing data.

  5. Sliding stones of Racetrack Playa, Death Valley, USA: The roles of rock thermal conductivity and fluctuating water levels.

    Czech Academy of Sciences Publication Activity Database

    Kletetschka, Günther; Hooke, R. L.; Ryan, A.; Fercana, G.; McKinney, E.; Schwebler, K. P.

    2013-01-01

    Ro?. 195, 1 August (2013), s. 110-117. ISSN 0169-555X Institutional support: RVO:67985831 Keywords : Endorheic * Finite element modeling * hydrogeology * Racetrack playa * sliding stones Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.577, year: 2013

  6. Laboratory and field tests of the Sutron RLR-0003-1 water level sensor

    Science.gov (United States)

    Fulford, Janice M.; Bryars, R. Scott

    2015-01-01

    Three Sutron RLR-0003-1 water level sensors were tested in laboratory conditions to evaluate the accuracy of the sensor over the manufacturer’s specified operating temperature and distance-to-water ranges. The sensor was also tested for compliance to SDI-12 communication protocol and in field conditions at a U.S. Geological Survey (USGS) streamgaging site. Laboratory results were compared to the manufacturer’s accuracy specification for water level and to the USGS Office of Surface Water (OSW) policy requirement that water level sensors have a measurement uncertainty of no more than 0.01 foot or 0.20 percent of the indicated reading. Except for one sensor, the differences for the temperature testing were within 0.05 foot and the average measurements for the sensors were within the manufacturer’s accuracy specification. Two of the three sensors were within the manufacturer’s specified accuracy and met the USGS accuracy requirements for the laboratory distance to water testing. Three units passed a basic SDI-12 communication compliance test. Water level measurements made by the Sutron RLR-0003-1 during field testing agreed well with those made by the bubbler system and a Design Analysis Associates (DAA) H3613 radar, and they met the USGS accuracy requirements when compared to the wire-weight gage readings.

  7. Assessment of Water Quality and Heavy Metal Levels in Water and Bottom Sediment Samples from Mokwé Lagoon, Accra, Ghana

    Directory of Open Access Journals (Sweden)

    M.A. Addo

    2012-02-01

    Full Text Available The current study deals with the physicochemical characteristics of water samples from the Mokwé Lagoon in addition to trace heavy metals (Cd, Cr, Ni, Pb and Zn in the lagoon water and bottom sediments. The results indicated relatively high ionic content which was reflected in high conductivity, total dissolved Solids, alkalinity, hardness and chloride levels; and low nutrient content. The trace heavy metal levels in the lagoon water were found within good range of international guideline limits for natural waters. In contrast, the metallic levels in the sediment were high. The levels of metal contamination and distribution in the sediment samples were assessed using geoaccumulation index, enrichment factor, contamination factor and pollution load factor. The metal index analysis indicated high enrichment of the metals (especially Cr and Ni which reflected anthropogenic effects of contamination attributable to several sources. The study calls for constant environmental monitoring to forestall any heavy metal hazard which could be detrimental to the aquatic ecosystem of the lagoon.

  8. Radioactivity levels in well water supplies within the greater Chicago area

    International Nuclear Information System (INIS)

    The radiological analysis of well water supplies within the geographical boundaries of the Metropolitan Sanitary District of Greater Chicago was prompted by the relatively high total alpha levels encountered in wastewaters of a MSDGC water reclamation plant as compared to the wastewaters of the other waste treatment plants. Consequently, 87 wells constituting 42 water supplies were sampled and analyzed for total alpha and beta radioactivity. The wells were grouped according to depth. In general, both total alpha and total beta radioactivity concentrations were found to be a function of well depth. The relatively higher total alpha and beta activities in the wastewaters to one of the treatment plants was attributed to the higher levels found in the well water supply. Comparison with the USEPA's Drinking Water Regulations for Radionuclides (July 9, 1976) showed the maximum total alpha level of 15 pCi/liter was exceeded in 3 wells and 32 of the deep well waters had total alpha level greater than 5 pCi/liter. The total beta level of 50 pCi/liter was exceeded in 8 wells

  9. Effects of pumping on ground-water levels near Taylorsville, Bartholomew County, Indiana

    Science.gov (United States)

    Planert, Michael; Tucci, Patrick

    1979-01-01

    A two-dimensional digital flow model was used to estimate the effects of continuous pumping of a public-supply well field on the ground-water levels near Taylorsville, Indiana. Results of the modeling showed that the water levels would decline from less than 1 to about 4.5 feet within the study area and a maximum of 1 to 2 feet in Taylorsville in response to a pumping rate of 700 gallons per minute. Model results also show that the ground-water system would reach steady state in approximately 5 years after pumping begins. Corrections applied to water-level declines indicated by the model, to account for the effects of partial penetration of the aquifer by wells, showed that these effects, although substantial in the pumping wells, are negligible 200 feet from the wells. (Woodard-USGS)

  10. Linking levels of societal and ecosystems metabolism of water in a Mediterranean watershed

    Science.gov (United States)

    Cabello, V.

    2014-12-01

    Water resources degradation is a complex environmental problem that involves multiple dimensions and scales of analysis. The Socio-Ecological Systems Water Metabolism has been proposed as a general holistic framework to deal with integrated analysis of water use sustainability (Madrid and Giampietro 2014). The innovation of the approach is that it sets the research focus beyond the classical supply-demand modeling to societal integrity and ecosystems integrity. To do so, it integrates quantitative grammars of water use (relating water exchange to societal and ecosystems organization) and qualitative methods (discourse analysis). This work presents the first case study focused at a river basin extent: the Upper Andarax, in South-East Spain. Water metabolism is indicated at multiple levels for ecosystems and society. To deal with the interfaces among them, relational indicators of water exploitation, water use and impact over ecosystems are used alongside policies and narratives analysis.While being a rather not intensively exploited river basin (year Water Exploitation Index~0.3 blue water,~0.15 green water), impacts over water bodies are yet important (periodic aquifer overdraft, biological degradation of the river) especially during dry season. Perceived mayor problems of water sustainability are generated by the not integration of different policies at European, national and regional scales: while the water authority establishes a compulsory reduction over water withdrawal to attend environmental flows, agricultural markets force to raise productivity increasing water demands. Adaptation strategies are divided among irrigation efficiency improvement and a reorientation of the economy towards touristic activities. Both of them entail specific trade-offs to be deemed. Aquifer-river interactions and climate change impacts are yet mayor research challenges.

  11. Stratification in the reactor water level instrumentation system caused by backfill modification in a BWR plant

    International Nuclear Information System (INIS)

    Due to the radiolysis inside Boiling Water Reactors, gases will be generated and can submerge into the water of the reference leg of the instrumentation. This will induce erroneous indication of RPV water level. To correct this phenomenon, a continuous backfill system is designed for most of the BWR plants. However, this backfill modification requires an injection of cold water into the instrumentation line. This condition will cause thermal stratification of the instrument system and create additional loading on piping, equipment and reactor nozzle. Analytical procedure is developed to convert a three-dimensional thermal hydraulic and conjugate heat transfer solution into stratification moments and local stresses on the condensing chamber and to determine the variable stratification moments and local stresses of the pipe. This procedure enables the qualification of the reactor water level instrumentation system by a standard pipe stress analysis computer code

  12. Acute gastrointestinal effects of graded levels of copper in drinking water.

    OpenAIRE

    F. Pizarro; Olivares, M.; Uauy, R.; Contreras, P.; Rebelo, A; Gidi, V

    1999-01-01

    The objective of this study was to determine the acute gastrointestinal effects caused by the consumption of drinking water containing graded levels of added copper. Sixty healthy, adult women were randomly assigned to receive copper [Cu(II)] at four concentrations in their drinking water following a Latin-square design. Each group (n = 15) received tap water with no added copper, 1, 3, and 5 mg Cu/l of added copper sulfate for a 2-week study period, followed by 1 week of standard tap water. ...

  13. Trench water chemistry at commercially operated low-level radioactive waste disposal sites

    International Nuclear Information System (INIS)

    Water samples from the disposal trenches of two low-level radioactive-waste-disposal sites were analyzed for their inorganic, organic, and radionuclide contents. Since oxidation of the trench waters can occur during their movement along the groundwater flow path, experiments were performed to measure the chemical and physical changes that occur in these waters upon oxidation. Low concentrations of chelating agents, shown to exist in trench waters, may be responsible for keeping radionuclides, particularly 60Co, in solution. 4 figures, 5 tables

  14. HEADCO: a program for converting observed water levels and pressure measurements to formation pressure and standard hydraulic head

    International Nuclear Information System (INIS)

    Static water-level and fluid pressure measurements are commonly converted in hydrologic studies to formation pressure and hydraulic head, which are used to determine groundwater flow characteristics of aquifer systems. While the direct use of field measurements is usually adequate for determining formation pressure and hydraulic head for shallow flow systems (i.e., <1000 ft), corrections and conversion parameters must be used to properly account for fluid-column density effects, which commonly occur with deep systems. This report presents a program, HEADCO, for converting static water-level and pressure measurements to formation pressure and standard hydraulic head. The HEADCO program corrects field measurements for the effects of fluid-density variation and selected external stresses. Factors that affect density of the fluid column, in which field measurements are made, include temperature, pressure, salinity, suspended solids, and multiphase conditions. External stresses examined in HEADCO include barometric and earth tide fluctuations, and gravitational acceleration variation. A program description and procedures for converting field measurements obtained using field test arrangements commonly employed in the Basalt Waste Isolation Project field program are provided in this report. The report includes user instructions and an illustrative test example. Results of a field example comparison are also provided. This comparison examines observed and HEADCO-calculated pressures for 30 pressure probes recently calibrated in a laboratory and tested under field conditions at borehole DC-8. The test case and field example comparisons indicate that HEADCO provides accurate estimates of formation pressure and standard hydraulic head that are well within the accuracy range of downhole pressure-measuring instrumentation. 44 refs., 14 figs., 8 tabs

  15. Reactor core water level monitor system and startup for CPR1000 nuclear power plant

    International Nuclear Information System (INIS)

    Reactor core water level monitor system is an important system used in CPR1000 nuclear power plant for monitoring the water level of reactor core after LOCA accident. The level measured by this system is used directly in the accident operation procedure. The principle of the measurement and the component of the system were introduced. According to the startup work of the first project for CPR1000, the goal for the first startup of this system relying on domestic engineering team was achieved. (authors)

  16. Diffuse radiation increases global ecosystem-level water-use efficiency

    Science.gov (United States)

    Moffat, A. M.; Reichstein, M.; Cescatti, A.; Knohl, A.; Zaehle, S.

    2012-12-01

    Current environmental changes lead not only to rising atmospheric CO2 levels and air temperature but also to changes in air pollution and thus the light quality of the solar radiation reaching the land-surface. While rising CO2 levels are thought to enhance photosynthesis and closure of stomata, thus leading to relative water savings, the effect of diffuse radiation on transpiration by plants is less clear. It has been speculated that the stimulation of photosynthesis by increased levels of diffuse light may be counteracted by higher transpiration and consequently water depletion and drought stress. Ultimately, in water co-limited systems, the overall effect of diffuse radiation will depend on the sensitivity of canopy transpiration versus photosynthesis to diffuse light, i.e. whether water-use efficiency changes with relative levels of diffuse light. Our study shows that water-use efficiency increases significantly with higher fractions of diffuse light. It uses the ecosystem-atmosphere gas-exchange observations obtained with the eddy covariance method at 29 flux tower sites. In contrast to previous global studies, the analysis is based directly on measurements of diffuse radiation. Its effect on water-use efficiency was derived by analyzing the multivariate response of carbon and water fluxes to radiation and air humidity using a purely empirical approach based on artificial neural networks. We infer that per unit change of diffuse fraction the water-use efficiency increases up to 40% depending on diffuse fraction levels and ecosystem type. Hence, in regions with increasing diffuse radiation positive effects on primary production are expected even under conditions where water is co-limiting productivity.

  17. DENTAL CARIES AND FLOUROSIS IN DIFFERENT LEVELS OF DRINKING WATER FLOURIDE

    OpenAIRE

    H KHademi; M TALEB

    2000-01-01

    Introduction. In some area of our country for example: Bushehre, some parts of Hormozgan, Yazd, Azarbayjan provinces, the levels of fIouride in drinking water is over optimom level. So because of this reason the incidence of flourosis in these areas is high. Determination of dental flourosis in four areas of Najafabad, Filor, Joozdan and Rahmatabad with different levels of flourosis with DMFT index is the aim of this study. Methods. This study is a cross sectional study. Samples have bee...

  18. Seasonal, sub-seasonal and spatial fluctuations in oxygen-depleted bottom waters in an embayment of an eastern boundary upwelling system: St Helena Bay

    Science.gov (United States)

    Pitcher, G. C.; Probyn, T. A.

    2015-08-01

    The considerable impact of oxygen deficient waters on marine resources in St Helena Bay has generated interest in exploring the vulnerability of South Africa's largest and most productive bay to further deoxygenation in response to climate change. Seasonal, sub-seasonal and spatial fluctuations in bottom dissolved oxygen (DO) are examined in St Helena Bay to facilitate better interpretation of historical data. DO measurements in relation to physical, chemical and biological variables were made between November 2013 and November 2014. Alongshore bay characteristics were assessed through comparison of variables along the 50 m depth contour. A mean coefficient of variation of 0.35 provided a measure of the relative variability of near-bottom DO concentrations along this contour. Across-shelf transects captured the seasonal development of hypoxia in relation to the distribution of phytoplankton biomass. DO was lowest in autumn in the south of the bay prior to winter ventilation of the bottom waters. Exceptional dinoflagellate blooms forming extensive subsurface thin layers preceded the autumn DO minima. The development of hypoxia at inner and central stations prior to expansion beyond the boundaries of the bay provided evidence of local drawdown. Coincident with the seasonal decline of DO within the bay was an increase in macronutrient concentrations which tended to mirror DO concentrations. Indication of denitrification in the suboxic waters in the south of the bay was provided through evidence of a nitrate deficit in autumn supported by elevated nitrite concentrations. Superimposed on the seasonal decline of DO concentrations in the bottom waters were sub-seasonal events of hypoxia and anoxia linked to episodic deposition of organic matter as indicated by increases in bottom Chl a concentrations.

  19. Water stress, CO2 and photoperiod influence hormone levels in wheat

    Science.gov (United States)

    Nan, Rubin; Carman, John G.; Salisbury, Frank B.; Campbell, W. F. (Principal Investigator)

    2002-01-01

    'Super Dwarf' wheat (Triticum aestivum L.) plants have been grown from seed to maturity in the Mir space station where they were periodically exposed, because of microgravity and other constraints, to water deficit, waterlogging, high CO2 levels, and low light intensities. The plants produced many tillers, but none of them produced viable seed. Studies have been initiated to determine why the plants responded in these ways. In the present study, effects of the listed stresses on abscisic acid (ABA), indole-3-acetic acid (IAA) and isopentenyl adenosine ([9R]iP) levels in roots and leaves of plants grown under otherwise near optimal conditions on earth were measured. Hormones were extracted, purified by HPLC, and quantified by noncompetitive indirect ELISA. In response to water deficit, ABA levels increased in roots and leaves, IAA levels decreased in roots and leaves, and [9R]iP levels increased in leaves but decreased in roots. In response to waterlogging, ABA, IAA and [9R]iP levels briefly increased in roots and leaves and then decreased. When portions of the root system were exposed to waterlogging and/or water deficit, ABA levels in leaves increased while [9R]iP and IAA levels decreased. These responses were correlated with the percentage of the root system stressed. At a low photosynthetic photon flux (100 micromoles m-2 s-1), plants grown in continuous light had higher leaf ABA levels than plants grown using an 18 or 21 h photoperiod.

  20. Application of environmental isotopes to determine the cause of rising water levels in Lake Beseka, Ethiopia

    International Nuclear Information System (INIS)

    Water level in Lake Beskea, located in the Ethiopian Rift Valley, has been rising continuously for the last about 30 years. The surface area of the lake has increased from about 6 Km2 to the present 40 Km2 and has posed serious problems for environmental management, including inundation of grazing and cultivated lands and, potentially, railway tracks. Historically, the lake received recharge from precipitation, surface runoff in the catchment, groundwater discharge, surface runoff from nearby thermal springs. As the lake levels have risen, the thermal springs are now submerged. An increase in the discharge form these thermal springs may be the original cause of lake water rise, or they may have been submerged as a result of the rising water level. An initial study conducted in the 1970s attributed the rising lake levels to increased runoff from adjoining irrigated areas. However, stricter controls on irrigation runoff failed to check the rising lake levels. A multi-disciplinary study, including geophysical, hydrological, geochemical, isotopic, and modeling techniques was then initiated to determine the cause(s) of lake level rise. Results of piezometric and geophysical surveys indicate that the principal cause of rising water levels may be the increased inflow from submerged springs in the southwestern portion of the lake

  1. Wood–water interactions : Linking molecular level mechanisms with macroscopic performance

    DEFF Research Database (Denmark)

    Engelund, Emil Tang

    2011-01-01

    Predicting the performance of wood for decades ahead is important when using the material for structural purposes. The performance is closely related to the hierarchical material structure of wood and the dependent interaction with water in the structure. Accurately predicting wood performance therefore requires an understanding of material structure from molecular to macroscopic level as well as of the impact of water molecules. The objective of this work is to investigate the performance of wood in terms of mechanical response of the material and effect of water. To understand the latter, one must first know in which parts of the wood structure, water is located. If parts of the water in wood are held in capillaries in the wood structure, these water molecules interact with the material differently than those held within wood cell walls. In this study, the occurrence of capillary water in wood is investigated at high levels of relative humidity (RH), where capillary water might be present. Three different techniques are employed in overlapping RH regimes. The three techniques give similar results and show that the amount of capillary water is insignificant up to at least 99.5 % RH. Thus, for wood in equilibrium with surrounding climate in the RH range 0-99.5 %, water is only significantly present within cell walls. A structural model of a wood cell is developed in this study using Finite Element Method for predicting the mechanical performance of wood. The starting point for the model is the physical behaviour on the molecular level since water interferes with wood at this level. The elastic material properties of the wood cell wall are explained by the organisation of wood constituents and their properties. The effect of water as well as temperature is incorporated by considering the amount of hydrogen bonds between wood constituents and the stiffness of these bonds. The mechanical response of wood includes a substantial time-dependent response, which previously has been explained by sliding between wood constituents on the molecular level. In this study, this is incorporated in the model as time-dependent shearing of the material planes of the cell wall. The calculated results of the model is verified against various experimental results from literature as well as from measurements presented in this work. It is shown that the structural model is able to describe a diverse range of mechanical responses of wood cells in both elastic and time-dependent domains. Furthermore, comparison of results from experiments and model suggests that the mechanical response of wood tissue, i.e. the hierarchical level above single wood cells, is a sum of responses from both wood cells and intercellular layer, i.e. the middle lamella.

  2. Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model

    International Nuclear Information System (INIS)

    This report is an updated analysis of water-level data performed to provide the ''Saturated Zone Site-Scale Flow Model'' (BSC 2004 [DIRS 170037]) (referred to as the saturated zone (SZ) site-scale flow model or site-scale SZ flow model in this report) with the configuration of the potentiometric surface, target water-level data, and hydraulic gradients for calibration of groundwater flow models. This report also contains an expanded discussion of uncertainty in the potentiometric-surface map. The analysis of the potentiometric data presented in Revision 00 of this report (USGS 2001 [DIRS 154625]) provides the configuration of the potentiometric surface, target heads, and hydraulic gradients for the calibration of the SZ site-scale flow model (BSC 2004 [DIRS 170037]). Revision 01 of this report (USGS 2004 [DIRS 168473]) used updated water-level data for selected wells through the year 2000 as the basis for estimating water-level altitudes and the potentiometric surface in the SZ site-scale flow and transport model domain based on an alternative interpretation of perched water conditions. That revision developed computer files containing: Water-level data within the model area (DTN: GS010908312332.002); A table of known vertical head differences (DTN: GS010908312332.003); and A potentiometric-surface map (DTN: GS010608312332.001) using an alternative concept from that presented by USGS (2001 [DIRS 154625]) for the area north of Yucca Mountain. The updated water-level data presented in USGS (2004 [DIRS 168473]) include data obtained from the Nye County Early Warning Drilling Program (EWDP) Phases I and II and data from Borehole USW WT-24. This document is based on Revision 01 (USGS 2004 [DIRS 168473]) and expands the discussion of uncertainty in the potentiometric-surface map. This uncertainty assessment includes an analysis of the impact of more recent water-level data and the impact of adding data from the EWDP Phases III and IV wells. In addition to being utilized by the SZ site-scale flow model, the water-level data and potentiometric-surface map contained within this report will be available to other government agencies and water users for groundwater management purposes. The potentiometric surface defines an upper boundary of the site-scale flow model and provides information useful to estimation of the magnitude and direction of lateral groundwater flow within the flow system. Therefore, the analysis documented in this revision is important to SZ flow and transport calculations in support of total system performance assessment (TSPA)

  3. Association of Down's syndrome and water fluoride level: a systematic review of the evidence

    Directory of Open Access Journals (Sweden)

    McDonagh Marian

    2001-07-01

    Full Text Available Abstract Background A review of the safety and efficacy of drinking water fluoridation was commissioned by the UK Department of Health to investigate whether the evidence supported a beneficial effect of water fluoridation and whether there was any evidence of adverse effects. Down's syndrome was one of the adverse effects reported. The aim of this review is to examine the evidence for an association between water fluoride level and Down's syndrome. Methods A systematic review of research. Studies were identified through a comprehensive literature search, scanning citations and online requests for papers. Studies in all languages which investigated the incidence of Down's syndrome in areas with different levels of fluoride in their water supplies were included. Study inclusion and quality was assessed independently by 2 reviewers. A qualitative analysis was conducted. Results Six studies were included. All were ecological in design and scored poorly on the validity assessment. The estimates of the crude relative risk ranged from 0.84 to 3.0. Four studies showed no significant associations between the incidence of Down's syndrome and water fluoride level and two studies by the same author found a significant (p Conclusions The evidence of an association between water fluoride level and Down's syndrome incidence is inconclusive.

  4. Fluctuation contents of phosphorus and natural radionuclide in the water column of the Mersing river, Johor, Malaysia

    International Nuclear Information System (INIS)

    Studies on natural radionuclides such as 210Po and 210Pb with the concentration of phosphorus in water column related to suspended particulate matter (SPM) were carried out at the Mersing River, Johor, Malaysia. Sixteen water samples were collected from nine stations on the 4th July 2010. 210Po and 210Pb activities varied between 0.76 to 2.24 mBq/L and 0.16 to 1.60 mBq/L respectively. The phosphorus concentrations, comprising total dissolved phosphorus (TDP), soluble reactive phosphorus (SRP) and dissolved organic phosphorus (DOP), were within the ranges of 6.06 to 23.31 ?g/L, 2.24 to 13.42 ?g/L and 0.47 to 16.10 ?/L, respectively. The concentration of TDP and salinity shows weak positive correlation (r = 0.39), perhaps due to the shallow depth of the Mersing River. There is a high positive correlation (r = 0.85) of 210Po activity with SPM concentration and a moderately positive correlation (r =0.59) of 210Po and TDP in water. The Kd values in suspended particulate matter are much higher compare to that in dissolved phase, proving that the adsorption of radionuclides to particles is more dominant. This implies that SPM significantly influences the variation of the P compound and both radionuclides in the Mersing River. This corresponds with agricultural activities from palm oil estates; erosion of the river bank due to river runoff; advection of suspended particulates from surface sediment due to boat and ferry traffic at the jetties; sedimentation; domestic sewage from nearby terrestrial areas; and natural processes; all of which might have resulted in their introduction to the Mersing River. (author)

  5. Estimation of Missing Water-Level Data for the Everglades Depth Estimation Network (EDEN)

    Science.gov (United States)

    Conrads, Paul A.; Petkewich, Matthew D.

    2009-01-01

    The Everglades Depth Estimation Network (EDEN) is an integrated network of real-time water-level gaging stations, ground-elevation models, and water-surface elevation models designed to provide scientists, engineers, and water-resource managers with current (2000-2009) water-depth information for the entire freshwater portion of the greater Everglades. The U.S. Geological Survey Greater Everglades Priority Ecosystems Science provides support for EDEN and their goal of providing quality-assured monitoring data for the U.S. Army Corps of Engineers Comprehensive Everglades Restoration Plan. To increase the accuracy of the daily water-surface elevation model, water-level estimation equations were developed to fill missing data. To minimize the occurrences of no estimation of data due to missing data for an input station, a minimum of three linear regression equations were developed for each station using different input stations. Of the 726 water-level estimation equations developed to fill missing data at 239 stations, more than 60 percent of the equations have coefficients of determination greater than 0.90, and 92 percent have an coefficient of determination greater than 0.70.

  6. Mixing height over water and its role on the correlation between temperature and humidity fluctuations in the unstable surface layer

    DEFF Research Database (Denmark)

    Sempreviva, A.M.; Gryning, Sven-Erik

    2000-01-01

    Results from an experimental investigation of the mixing height over inner Danish waters carried out from September 1990 to October 1992, are discussed. The statistical analysis of the mixed-layer height (z(i)) over the sea does not exhibit the daily variation that is characteristic of the mixed layer over land, but it is nearly constant over a 24-hour cycle. During summer, the mixed layer is higher than during winter. A second inversion was often observed. A case study of the development of the...

  7. Early Water Stress Detection Using Leaf-Level Measurements of Chlorophyll Fluorescence and Temperature Data

    Directory of Open Access Journals (Sweden)

    Zhuoya Ni

    2015-03-01

    Full Text Available The purpose of this paper was to investigate the early water stress in maize using leaf-level measurements of chlorophyll fluorescence and temperature. In this study, a series of diurnal measurements, such as leaf chlorophyll fluorescence (Fs, leaf spectrum, temperature and photosynthetically active radiation (PAR, were conducted for maize during gradient watering and filled watering experiments. Fraunhofer Line Discriminator methods (FLD and 3FLD were used to obtain fluorescence from leaves spectrum. This simulated work using the SCOPE model demonstrated the variations in fluorescence and temperature in stress levels expressed by different stress factors. In the field measurement, the gradient experiment revealed that chlorophyll fluorescence decreased for plants with water stress relative to well-water plants and Tleaf-Tair increased; the filled watering experiment stated that chlorophyll fluorescence of maize under water stress were similar to those of maize under well-watering condition. In addition, the relationships between the Fs, retrieved fluorescence, Tleaf-Tair and water content were analyzed. The Fs determination resulted to the best coefficients of determination for the normalized retrieved fluorescence FLD/PAR (R2 = 0.54, Tleaf-Tair (R2 = 0.48 and water content (R2 = 0.71. The normalized retrieved fluorescence yielded a good coefficient of determination for Tleaf-Tair (R2 = 0.48. This study demonstrated that chlorophyll fluorescence could reflect variations in the physiological states of plants during early water stress, and leaf temperature confirmed the chlorophyll fluorescence analysis results and improved the accuracy of the water stress detection.

  8. Water Levels and Selected Water-Quality Conditions in the Mississippi River Valley Alluvial Aquifer in Eastern Arkansas, 2006

    Science.gov (United States)

    Schrader, T.P.

    2008-01-01

    During the spring of 2006, the U.S. Geological Survey, in cooperation with the Arkansas Natural Resource Commission and the Arkansas Geological Survey, measured water levels in 707 wells completed in the Mississippi River Valley alluvial aquifer in eastern Arkansas. Ground-water levels are affected by ground-water withdrawals resulting in depressions. In 2006, the lowest water-level altitude was 76 feet above the National Geodetic Vertical Datum of 1929 in the center of Arkansas County. The highest water-level altitude was 289 feet above the National Geodetic Vertical Datum of 1929 in northeastern Clay County on the west side of Crowleys Ridge. Two large depressions in the potentiometric surface are located in Arkansas, Lonoke, and Prairie Counties and west of Crowleys Ridge in Craighead, Cross, Lee, Monroe, Poinsett, St. Francis, and Woodruff Counties. The elongated depression in Arkansas, Lonoke, and Prairie Counties has changed in areal extent or depth when compared to previous conditions of the aquifer. The area in Arkansas County at the southeastern half of the depression has not expanded horizontally during recent years, although the center of the depression has deepened. The area in Lonoke and Prairie Counties in the northwestern half of the depression has expanded horizontally in the deeper part of the depression. The 90-foot contour has expanded north and east in Lonoke County when compared with the 2004 potentiometric surface. Along the west side of Crowleys Ridge the 2006 potentiometric-surface map shows very little change in the area of this depression, although the deeper areas within the depression have expanded. A map showing the difference in water level was constructed using 645 differences in water-levels measured in 633 wells during 2002 and 2006. The difference in measured water levels from 2002 to 2006 ranged from -24.0 feet to 25.0 feet, with a mean of -2.0 feet. The largest decline of -24.0 feet occurred in Poinsett County and the largest rise of 25.0 feet occurred in Randolph County. Out of the 645 differences, 481 were declines (74.6 percent), 12 were no difference (values of 0.0 ft) (1.8 percent), and 152 were rises (23.6 percent). Long-term water-level trends were evaluated using hydrographs from 152 wells completed in the Mississippi River Valley alluvial aquifer for the period 1982 to 2006. The mean annual rise or decline in water level for the entire study area was -0.32 feet per year with a range of -1.28 to 0.77 feet per year. Independence and White Counties are the only counties with a mean annual rise from 1982 to 2006. Mean annual declines between -0.50 feet per year and 0.00 feet per year occurred in Arkansas, Ashley, Chicot, Clay, Craighead, Crittenden, Drew, Jefferson, Lee, Mississippi, Monroe, Phillips, Poinsett, Prairie, Pulaski, Randolph, and Woodruff Counties. Mean annual declines between -1.00 feet per year and -0.50 feet per year occurred in Cross, Desha, Greene, Jackson, Lincoln, Lonoke, and St. Francis Counties. The analysis of long-term water-level changes in Arkansas, Lonoke, and Prairie Counties shows the elongation of the depression in these three counties. Both Arkansas and Prairie Counties have two different rates of annual decline for the two hydrographs shown for each county. Water levels in the two wells near the Arkansas and White Rivers either have risen or declined at a slower rate than in the three wells in the center, northern, and western part of the depression. These rates of water-level change indicate that this depression is expanding in an elongated direction north and west into Lonoke and Prairie Counties. The depression west of Crowleys Ridge has five wells with hydrographs in or near the depression that can be used to characterize the rates of water-level change within the depression. Water samples were collected from 65 wells completed in the Mississippi River Valley alluvial aquifer and measured onsite for specific conductance and tempera

  9. Characterization of a spent-fuel-pit rupture based on water-level monitoring

    International Nuclear Information System (INIS)

    Highlights: • Spent-fuel pit’s shell integrity is assessed indirectly after the initiating event. • Based on water-level elevation monitoring, rupture-size and elevation are predicted. • The water-level elevation trend and the characteristic time lags are also predicted. • The theoretical-calculation procedure uses measurable in situ data. • The self-sufficient procedure can be integrated into existing acquisition systems. - Abstract: In the course of the Fukushima accident, there were concerns raised with regard to the safety of the spent fuel. This concern was further justified by the very short grace time available in high-density fuel pools if the active cooling gets interrupted or the integrity of the shell is compromised. The purpose of this study is to provide a theoretical-calculation procedure for predicting the spent-fuel system’s shell integrity and the elevation of the water level. Based on water-level monitoring during a given nuclear event, the rupture was characterized in terms of the mean cross-section and the elevation of the crack, while the water-level elevation was predicted for the period after the initiating events

  10. The need for the use of high-level radiation in water treatment and in waste-water (sewage) treatment

    International Nuclear Information System (INIS)

    After excellent conventional primary, followed by the best possible conventional aerobic secondary and then chemical disinfection, significant quantities of contaminants are still present in sewage, especially pathogenic organisms and toxic or toxicity-causing long-chain-molecular forms. These contaminants are generally encountered in waste-waters with a seldom predictable, almost totally random frequency. Many of these chemical forms enter re-use situations where they can become toxic to man, or to wildlife, even in concentrations of a few parts per thousand million. It has been amply demonstrated that the long-held contention is no longer valid that dilution of these contaminants to an innocuous level is easily attained by their release into large bodies of water such as lakes, oceans and rivers. At the same time, a great deal of energy is required when using known techniques in highly reliable systems for removing or rendering innocuous a large portion of these contaminants. In the light of this new (to some people) information describing a much larger, more complex set of conditions which must be considered in effective water pollution elimination, high-level radiation becomes very attractive. There is a great need for high-level radiation in water treatment or waste-water treatment where the ultimate goal is a safe, clean, non-environmentally degrading, safely re-usable quality of water. Gamma radiation, used under the right circumstances, is the most reliable, most cost-effective, most generally efficient technique in the tertiary stages. With the addition of select chemicals to increase the number of ionizations realized and/or to capitalize upon surface charge phenomena, its effectiveness can be even further expanded. (author)

  11. Groundwater-surface water relations in regulated lowland catchments; hydrological, hydrochemical, and ecological effects of a major change in surface water level management

    Science.gov (United States)

    Rozemeijer, J.; Hendriks, D.; Klein, J.; Borren, W.

    2013-12-01

    Some water management questions can only be answered after a thorough assessment of groundwater-surface water interactions. In lowland deltas with intensive land use such as The Netherlands, surface water levels are tightly controlled by inlet of diverted river water during dry periods and discharge via large-scale pumping stations during wet periods. The objective of the presented study was to assess the hydrological, hydrochemical, and ecological effects of a major change in water level management. Ten study catchments were hydrologically isolated and surface water level control was changed from a virtually constant water level to a more natural regime with high water levels in winter and low water levels in summer. The effects were intensively monitored in a dense multi-scale network of measurement locations for surface water and groundwater levels and solute concentrations. We used water and solute balancing for catchment-scale assessments of changes in water and solute fluxes. For field-scale evaluations, we used a transient 2D groundwater -surface water modeling approach. We found that the change to a more natural water level regime reduces the exchange of water and solutes between groundwater and surface water. Also, discharge from the catchment in wet periods is reduced and less diverted river water is needed in dry periods. This reduces pumping costs and partly restores the natural capacity of the catchment to buffer extreme precipitation and droughts. Chemical and ecological water quality may benefit from the reduced inlet of nutrient-rich, alkaline diverted river water. However, longer residence times intensified the impact of local nutrient sources, which resulted in elevated N concentrations in all catchments.

  12. Modeling Caspian Sea water level oscillations under different scenarios of increasing atmospheric carbon dioxide concentrations

    Directory of Open Access Journals (Sweden)

    Roshan GholamReza

    2012-12-01

    Full Text Available Abstract The rapid rise of Caspian Sea water level (about 2.25 meters since 1978 has caused much concern to all five surrounding countries, primarily because flooding has destroyed or damaged buildings and other engineering structures, roads, beaches and farm lands in the coastal zone. Given that climate, and more specifically climate change, is a primary factor influencing oscillations in Caspian Sea water levels, the effect of different climate change scenarios on future Caspian Sea levels was simulated. Variations in environmental parameters such as temperature, precipitation, evaporation, atmospheric carbon dioxide and water level oscillations of the Caspian sea and surrounding regions, are considered for both past (1951-2006 and future (2025-2100 time frames. The output of the UKHADGEM general circulation model and five alternative scenarios including A1CAI, BIASF, BIMES WRE450 and WRE750 were extracted using the MAGICC SCENGEN Model software (version 5.3. The results suggest that the mean temperature of the Caspian Sea region (Bandar-E-Anzali monitoring site has increased by ca. 0.17°C per decade under the impacts of atmospheric carbon dioxide changes (r=0.21. The Caspian Sea water level has increased by ca. +36cm per decade (r=0.82 between the years 1951-2006. Mean results from all modeled scenarios indicate that the temperature will increase by ca. 3.64°C and precipitation will decrease by ca. 10% (182 mm over the Caspian Sea, whilst in the Volga river basin, temperatures are projected to increase by ca. 4.78°C and precipitation increase by ca. 12% (58 mm by the year 2100. Finally, statistical modeling of the Caspian Sea water levels project future water level increases of between 86 cm and 163 cm by the years 2075 and 2100, respectively.

  13. Perfluorinated compounds: Levels, trophic web enrichments and human dietary intakes in transitional water ecosystems

    International Nuclear Information System (INIS)

    Highlights: • PFOA/S levels in a trophic web of a heavily human-stressed lagoon are measured. • High levels were found in mussels, clams and crabs. • The principal PFCs inflow sources for the ecosystem is the river. • Biota (i.e. macroalgae proliferation) contributes to redistribute pollutants in the lagoon. • Human daily dietary intakes are below maximum tolerable levels suggested by the EFSA. -- Abstract: The results of a study on levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), analyzed in terms of HPLC-ESI-MS in water, sediment, macrophyte, bivalve, crustacean and fish samples, are reported here. The aim of the research is to define, for the first time, PFOA/S levels in a heavily human-stressed transitional water ecosystem (Orbetello lagoon, Italy) and evaluate trophic web enrichments and human dietary intakes. The results obtained show that: (i) levels significantly higher than those reported in the literature were found in mussels, clams and crabs; (ii) the river is a significant pollution source; (iii) although absolute levels are relatively low, macroalgae proliferation contributes to redistribute pollutants from river-affected areas throughout the entire lagoon basin; (iv) to the best of our current knowledge, water-filtering species considered in this study are the most exposed to PFOA/S pollution; (v) human daily dietary intakes of PFOA/S through Slow Food-endorsed product consumption are below maximum tolerable levels suggested by the EFSA

  14. Hydraulic Properties and Water Level Changes in the Missouri Coteau near Minot N.D

    Science.gov (United States)

    Kilroy, K. C.; Nissen, J. A.

    2012-12-01

    The city of Minot, N.D. is experiencing rapid population growth due to expansion of petroleum extraction from oil shale in the Williston Basin. Minot is located on the edge of the Missouri Escarpment, which separates the Missouri Coteau upland (site of Prairie Potholes) to the southwest and the Mouse (Souris) River Basin to the northeast (lowland Drift Prairie). The Missouri Coteau is underlain by horizontally bedded Fort Union Formation (Tertiary sand, silt, and clay) and covered with Quaternary glacial till, as much as 130-feet thick. Surface water on the crest of the Missouri Coteau is deranged and the high areas do not flow coherently out of the area, but lower elevation slopes do have integrated dendritic drainage. Despite deranged surface-water flow in the Missouri Coteau upland area, ground water slopes more or less coherently to the North East towards the Mouse River. The North East slope of the Missouri Coteau has primarily agricultural land use, mostly dry-land farming. There is little irrigated farming here. Water is used for livestock and domestic purposes. Ground water levels were compiled for the region in and around Minot in 1968, and more-recently-drilled wells are documented in the web site of the N.D. State Water Commission. About 20-years ago, the North Prairie Rural Water District (NPRWD) expanded into the Missouri Coteau (near Minot). The North Prairie Rural water is softer than local well water; it is much preferred by residents; and as a result the water district has undergone expansion. This has led to disuse, neglect, and abandonment of rural wells. In addition, the current time frame appears to be the beginning of a sustained period of urban growth and much more rapid ground water use in the Minot area. We hypothesize that water levels have fallen since the 1960's, particularly in and near the Minot City well field. We also hypothesize that more detailed study of hydraulic properties, horizontal extent of local geologic materials, and glacial features, may yield a better understanding of local conditions at the end of the Pleistocene Epoch. Water levels were canvased in 30 wells along a line running N 45o E (at a right angle to the trend of Missouri Escarpment) from the crest of the Missouri Coteau near Rice Lake, through the Minot city well field near the Mouse (Souris) River, a horizontal distance of 20 miles, during the summer of 2012. Water levels have dropped as much as 23-feet in wells dug into Mouse River Alluvium, but little water level drop has occurred in the Missouri Coteau uplands. There are flowing wells on the lower slopes of the Missouri Coteau. Most flowing wells appear to be associated with deeply incised Mouse River tributaries, locally called: "coulees", and wells deep enough to penetrate through glacial till into underlying Ft. Union Formation. Glacial till appears to form a confining layer over the deeper Fort Union Formation allowing the accumulation of water pressure leading to artesian and flowing conditions. There is little evidence of water level decline in the area of flowing wells. There is however, an interesting correlation of flowing wells with polygonally patterned ground, which look suspiciously like relicts of peri-glacial pingoes. Water levels higher on the Missouri Coteau (furthest from Minot) show little change.

  15. Rapid fluctuations in flow and water-column properties in Asan Bay, Guam: implications for selective resilience of coral reefs in warming seas

    Science.gov (United States)

    Storlazzi, C.D.; Field, M.E.; Cheriton, O.M.; Presto, M.K.; Logan, J.B.

    2013-01-01

    Hydrodynamics and water-column properties were investigated off west-central Guam from July 2007 through January 2008. Rapid fluctuations, on time scales of 10s of min, in currents, temperature, salinity, and acoustic backscatter were observed to occur on sub-diurnal frequencies along more than 2 km of the fore reef but not at the reef crest. During periods characterized by higher sea-surface temperatures (SSTs), weaker wind forcing, smaller ocean surface waves, and greater thermal stratification, rapid decreases in temperature and concurrent rapid increases in salinity and acoustic backscatter coincided with onshore-directed near-bed currents and offshore-directed near-surface currents. During the study, these cool-water events, on average, lasted 2.3 h and decreased the water temperature 0.57 °C, increased the salinity 0.25 PSU, and were two orders of magnitude more prevalent during the summer season than the winter. During the summer season when the average satellite-derived SST anomaly was +0.63 °C, these cooling events, on average, lowered the temperature 1.14 °C along the fore reef but only 0.11 °C along the reef crest. The rapid shifts appear to be the result of internal tidal bores pumping cooler, more saline, higher-backscatter oceanic water from depths >50 m over cross-shore distances of 100 s of m into the warmer, less saline waters at depths of 20 m and shallower. Such internal bores appear to have the potential to buffer shallow coral reefs from predicted increases in SSTs by bringing cool, offshore water to shallow coral environments. These cooling internal bores may also provide additional benefits to offset stress such as supplying food to thermally stressed corals, reducing stress due to ultraviolet radiation and/or low salinity, and delivering coral larvae from deeper reefs not impacted by surface thermal stress. Thus, the presence of internal bores might be an important factor locally in the resilience of select coral reefs facing increased thermal stress.

  16. Rising water levels and the future of southeastern Louisiana swamp forests

    Science.gov (United States)

    Conner, W.H.; Brody, M.

    1989-01-01

    An important factor contributing to the deterioration of wetland forests in Louisiana is increasing water levels resulting from eustatic sea-level rise and subsidence. Analyses of long-term water level records from the Barataria and Verret watersheds in southeastern Louisiana indicate an apparent sea level rise of about 1-m per century, mainly the result of subsidence. Permanent study plots were established in cypress-tupelo stands in these two watersheds. The tree, water level, and subsidence data collected in these plots were entered into the U.S. Fish and Wildlife Servicea??s FORFLO bottomland hardwood succession model to determine the long-term effects of rising water levels on forest structure. Analyses were made of 50a??100 years for a cypress-tupelo swamp site in each basin and a bottomland hardwood ridge in the Verret watershed. As flooding increased, less flood tolerant species were replaced by cypress-tupelo within 50 years. As flooding continued, the sites start to become nonforested. From the test analyses, the FORFLO model seems to be an excellent tool for predicting long-term changes in the swamp habitat of south Louisiana.

  17. Support vector regression model based predictive control of water level of U-tube steam generators

    International Nuclear Information System (INIS)

    Highlights: • Water level of U-tube steam generators was controlled in a model predictive fashion. • Models for steam generator water level were built using support vector regression. • Cost function minimization for future optimal controls was performed by using the steepest descent method. • The results indicated the feasibility of the proposed method. - Abstract: A predictive control algorithm using support vector regression based models was proposed for controlling the water level of U-tube steam generators of pressurized water reactors. Steam generator data were obtained using a transfer function model of U-tube steam generators. Support vector regression based models were built using a time series type model structure for five different operating powers. Feedwater flow controls were calculated by minimizing a cost function that includes the level error, the feedwater change and the mismatch between feedwater and steam flow rates. Proposed algorithm was applied for a scenario consisting of a level setpoint change and a steam flow disturbance. The results showed that steam generator level can be controlled at all powers effectively by the proposed method

  18. Support vector regression model based predictive control of water level of U-tube steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Kavaklioglu, Kadir, E-mail: kadir.kavaklioglu@pau.edu.tr

    2014-10-15

    Highlights: • Water level of U-tube steam generators was controlled in a model predictive fashion. • Models for steam generator water level were built using support vector regression. • Cost function minimization for future optimal controls was performed by using the steepest descent method. • The results indicated the feasibility of the proposed method. - Abstract: A predictive control algorithm using support vector regression based models was proposed for controlling the water level of U-tube steam generators of pressurized water reactors. Steam generator data were obtained using a transfer function model of U-tube steam generators. Support vector regression based models were built using a time series type model structure for five different operating powers. Feedwater flow controls were calculated by minimizing a cost function that includes the level error, the feedwater change and the mismatch between feedwater and steam flow rates. Proposed algorithm was applied for a scenario consisting of a level setpoint change and a steam flow disturbance. The results showed that steam generator level can be controlled at all powers effectively by the proposed method.

  19. Prediction for water level of steam generator based on multi-signal fusion by support vector regression

    International Nuclear Information System (INIS)

    During change of marine nuclear power plant load, the water level of steam generator often waved heavily and even more false water level occurred. In the mean- time, water level measurement channels failed once in a while. All problems affected heavily self-regulation of water level and operator's correct judgment on the operation states. Therefore, a water level predicting method based on multi-signal reconstruction was brought forward. This method added relevant signals which may affect water level change as input information for prediction. Comparing with predicting method based on analyzing the history of water level change only, this method improves accuracy, stability and reliability of prediction, and supports predicting in longer term. (authors)

  20. Wave-induced extreme water levels in the Puerto Morelos fringing reef lagoon

    OpenAIRE

    Torres-Freyermuth, A.; Mariño-Tapia, I.; Coronado, C.; Salles, P.; G. Medellín; Pedrozo-Acuña, A.; Silva, R.; Candela, J.; Iglesias-Prieto, R.

    2012-01-01

    Wave-induced extreme water levels in the Puerto Morelos fringing reef lagoon are investigated by means of a phase-resolving non-hydrostatic wave model (SWASH). This model solves the nonlinear shallow water equations including non-hydrostatic pressure. The one-dimensional version of the model is implemented in order to investigate wave transformation in fringing reefs. Firstly, the numerical model is validated with (i) laboratory experiments conducted on a physical model (Demirbilek et al., 20...

  1. Measurement of the heavy water level in the fuel channels of the RA reactor - Annex 11

    International Nuclear Information System (INIS)

    The objective of measuring the heavy water level in the reactor channels was to verify experimentally the possibilities of reactor cooling with parallel operation of heavy water pumps od 1500 rotations/min at nominal power of 6.5 MW. Measurements were done in 2 periphery and 2 central fuel channels with pumps speed 1500, 1800 and 3000 rotations/min by a contact probe with electric resistance measuring device. precision of the measurement was ±1 cm

  2. PARTIAL LEAST SQUARES REGRESSION BASED VARIABLES SELECTION FOR WATER LEVEL PREDICTIONS

    OpenAIRE

    Noraini Ibrahim; Antoni Wibowo

    2013-01-01

    Floods are common phenomenon in the state of Kuala Krai, specifically in Kelantan-Malaysia. Every year, floods affecting biodiversity on this region and also causing property loss of this residential area. The residents in Kelantan always suffered from floods since the water overflows to the areas adjoining to the rivers, lakes or dams. Months, average monthly rainfall, temperature, relative humidity and surface wind were used as predictors while the water level of Galas River was used as res...

  3. Character and levels of radioactive contamination of underground waters at Semipalatinsk test site

    Energy Technology Data Exchange (ETDEWEB)

    Subbotin, S.; Lukashenko, S.; Turchenko, Y. [Institute of radiation safety and ecology (Kazakhstan)

    2014-07-01

    According to the data of RK government commission, 470 explosions have been set off at the Semipalatinsk Test Site (STS), inclusive of 26 surface, 90 in the air and 354 underground nuclear explosions (UNE), 103 of those have been conducted in tunnels and 251 - in boreholes. Underground nuclear explosions have been conducted at STS in horizontal mines, called - 'tunnels' ('Degelen' test site) and vertical mines called 'boreholes' ('Balapan' and 'Sary-Uzen' test sites). Gopher cavities of boreholes and tunnels are in different geotechnical conditions, that eventually specify migration of radioactive products with underground waters. Central cavities of UNE in holes are located significantly below the level of distribution of underground water. High temperature remains for a long time due to presence of overlying rock mass. High temperatures contribute to formation of thermal convection. When reaching the cavity, the water heat up, dissolve chemical elements and radionuclides and return with them to the water bearing formation. In the major part of 'Balapan' site for underground water of regional basin is characterized by low concentrations of radionuclides. High concentrations of {sup 137}Cs in underground water have been found only in immediate vicinity to 'warfare' boreholes. Formation of radiation situation in the 'Balapan' test site area is also affected by local area of underground water discharge. It is located in the valley of Shagan creek, where the concentration of {sup 3}H reaches 700 kBq/l. Enter of underground water contaminated with tritium into surface water well continue. In this case it is expected that tritium concentration in discharge zone can significantly change, because this migration process depends on hydro geological factors and the amount of atmospheric precipitation. Central cavities of nuclear explosions, made in tunnels, are above the level of underground water. Underground water gets discharged in the direction creek valleys. These creeks have inland drainage basins, that limits distribution of radionuclides with surface and underground water. According to results of investigations, at the territory, where UNE have been conducted {sup 137}Cs, {sup 90}Sr, {sup 239+240}Pu and tritium keep outflowing with tunnel waters beyond central zones of UNE. Levels of radionuclides concentration in tunnel water streams significantly exceed permissible values for drinking water. Herewith, nearly complete cleaning of tunnel waters from radionuclides (except tritium) happens thanks to rocks of river valleys. So, as a result of further migration of man-caused radionuclides with tunnel water, radioactive products will be slowly redistributed from central zones to river valets of Degelen massif. Generally we can note, that tritium was and will be in the future the main contaminator of underground water at the STS territory. Significant decrease of concentration of tritium beyond test sites can be explained by favourable conditions of infiltration. I.e. due to absence of continuous cover of non-coherent low permeable deposits, atmospheric fall-outs continuously penetrate into underground water, that leads to regular dilution of concentration of tritium, up to safe levels for drinking water. So the process of carrying-out of radionuclides by underground water beyond test sites of STS currently does not significantly affect formation of radioecological situation. Document available in abstract form only. (authors)

  4. Ground-Water Levels in Huron County, Michigan, 2006-07

    Science.gov (United States)

    Weaver, T.L.; Blumer, S.P.; Fuller, L.M.

    2008-01-01

    In 1990, the U.S. Geological Survey (USGS) completed a study of the hydrogeology of Huron County, Michigan (Sweat, 1991). In 1993, Huron County and the USGS entered into a continuing agreement to measure water levels at selected wells throughout Huron County. As part of the agreement, USGS initially operated four continuous water-level recorders, installed from 1988 to 1991 on wells in Bingham (H5r), Fairhaven (H9r), Grant (H2r), and Lake Townships (H25Ar) and summarized the data collected in an annual or bi-annual report (fig. 1). The agreement was altered in 2003, and beginning January 1, 2004, only wells H9r and H25Ar retained continuous water-level recorders, while wells H2r and H5r reverted to quarterly or periodic measurement status due to budget constraints. The decision of which two wells to discontinue was based on an analysis of the intrinsic value to Huron County of data from each well. Well H2r was selected for periodic measurement at that time because it is completed in the glacial aquifer, which is absent in much of Huron County and well H5r, which is completed in the Marshall aquifer, was selected because the water level in the well is often perturbed as a result of pumpage from nearby production wells and does not always reflect baseline conditions within the aquifer. USGS also has provided training for County or Huron Conservation District personnel to measure the water level in 24 of the wells on a quarterly basis. USGS personnel accompany County or Huron Conservation District personnel on a semi-annual basis to provide a quality assurance/quality control check of all measurements being made. Water-level data collected from the wells is summarized in an annual or bi-annual report. The altitude of Lake Huron and precipitation are good indicators of general climatic conditions and, therefore, provide an environmental context for ground-water levels in Huron County. Figure 2 shows the mean-monthly water-level altitude of Lake Huron, averaged from measurements made at Essexville and Harbor Beach (National Oceanic and Atmospheric Administration, 2008), and monthly precipitation measured in Harbor Beach, Sebewaing, and Bad Axe (National Oceanic and Atmospheric Administration, Danny Costello, written commun., 2007-08). In December 2007, the water level in Lake Huron dropped to a new monthly mean low of 576.38 ft for the period from 1988 through 2007 (the previous low-water level of 576.57 ft was measured in March 2003). The net decline in the water level of Lake Huron from January 2006 through December 2007 was 0.68 ft. In 2006, annual precipitation measured at Harbor Beach was 3.2 in. above the long-term average of 31.1 in., with 10.6 in. measured during the 2006 growing season (May through August). In 2007, annual precipitation measured at Harbor Beach was 1.4 in. below normal, with 9.7 in. measured during the growing season. In the two wells equipped with continuous water-level recorders, the water level rose 0.32 ft from January 1, 2006 to December 31, 2007 in well H9r, but declined 1.11 ft in well H25Ar. Curiously, well H9r is drilled adjacent to Saginaw Bay (Lake Huron), and, as previously noted, there was a 0.68 ft decline in the water level in Saginaw Bay during that period. Twenty four wells were measured on a quarterly or periodic basis from December 2005 through December 2007 (well H26 was destroyed during summer 2007 reducing the total number of wells from 25). These wells are completed in the glacial, Saginaw and Marshall aquifers, and the Coldwater confining unit. Although each quarterly or periodic measurement only provides a 'snapshot' water level (measured in ft below land surface, and altitude, in ft above sea level), the data adequately define the generalized water-level trend in the aquifer near the well. Water levels in 6 quarterly-measured wells had net rises ranging from 0.09 to 1.45 ft for the period, while water levels in 18 of the wells had net declines ranging from 0.26 to 2

  5. Water Phase Change Heat Exchanger System Level Analysis for Low Lunar Orbit

    Science.gov (United States)

    Navarro, Moses; Ungar, Eugene; Sheth, Rubik; Hansen, Scott

    2016-01-01

    In low Lunar orbit (LLO) the thermal environment is cyclic - extremely cold in the eclipse and as warm as room temperature near the subsolar point. Phase change material heat exchangers (PCHXs) are the best option for long term missions in these environments. The Orion spacecraft will use a n-pentadecane wax PCHX for its envisioned mission to LLO. Using water as a PCM material is attractive because its higher heat of fusion and greater density result in a lighter, more compact PCHX. To assess the use of a water PCHX for a human spacecraft in a circular LLO, a system level analysis was performed for the Orion spacecraft. Three cases were evaluated: 1) A one-to-one replacement of the wax PCHX on the internal thermal control loop with a water PCHX (including the appropriate control modifications), 2) reducing the radiator return setpoint temperature below Orion's value to enhance PCHX freezing, and 3) placing the water PCM on the external loop. The model showed that the water PCHX could not be used as a drop-in replacement for the wax PCHX. It did not freeze fully during the eclipse owing to its low freezing point. To obtain equivalent performance, 40% more radiator area than the Orion baseline was required. The study shows that, although water PCHXs are attractive at a component lev