WorldWideScience

Sample records for maximum water levels

  1. 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...

  2. The application of a Grey Markov Model to forecasting annual maximum water levels at hydrological stations

    Science.gov (United States)

    Dong, Sheng; Chi, Kun; Zhang, Qiyi; Zhang, Xiangdong

    2012-03-01

    Compared with traditional real-time forecasting, this paper proposes a Grey Markov Model (GMM) to forecast the maximum water levels at hydrological stations in the estuary area. The GMM combines the Grey System and Markov theory into a higher precision model. The GMM takes advantage of the Grey System to predict the trend values and uses the Markov theory to forecast fluctuation values, and thus gives forecast results involving two aspects of information. The procedure for forecasting annul maximum water levels with the GMM contains five main steps: 1) establish the GM (1, 1) model based on the data series; 2) estimate the trend values; 3) establish a Markov Model based on relative error series; 4) modify the relative errors caused in step 2, and then obtain the relative errors of the second order estimation; 5) compare the results with measured data and estimate the accuracy. The historical water level records (from 1960 to 1992) at Yuqiao Hydrological Station in the estuary area of the Haihe River near Tianjin, China are utilized to calibrate and verify the proposed model according to the above steps. Every 25 years' data are regarded as a hydro-sequence. Eight groups of simulated results show reasonable agreement between the predicted values and the measured data. The GMM is also applied to the 10 other hydrological stations in the same estuary. The forecast results for all of the hydrological stations are good or acceptable. The feasibility and effectiveness of this new forecasting model have been proved in this paper.

  3. [Substantiation of maximum permissible water level of the flotation reagent EFK-1].

    Science.gov (United States)

    Turbinskiĭ, V V

    1991-12-01

    Threshold concentrations of the flotation reagent EFK-1 in the water of reservoirs at 0.8 mg/l and 10.0 mg/l for organoleptic and total sanitary indices, respectively, were reported. Dl50 was 7469 mg/kg. The MAC of 0.8 mg/l for EFK-1 in the water of reservoirs (the limiting sign is organoleptic) was proposed.

  4. Maximum Water Hammer Sensitivity Analysis

    OpenAIRE

    Jalil Emadi; Abbas Solemani

    2011-01-01

    Pressure waves and Water Hammer occur in a pumping system when valves are closed or opened suddenly or in the case of sudden failure of pumps. Determination of maximum water hammer is considered one of the most important technical and economical items of which engineers and designers of pumping stations and conveyance pipelines should take care. Hammer Software is a recent application used to simulate water hammer. The present study focuses on determining significance of ...

  5. Contribution to the study of maximum levels for liquid radioactive waste disposal into continental and sea water. Treatment of some typical samples

    International Nuclear Information System (INIS)

    Bittel, R.; Mancel, J.

    1968-10-01

    The most important carriers of radioactive contamination of man are the whole of foodstuffs and not only ingested water or inhaled air. That is the reason why, in accordance with the spirit of the recent recommendations of the ICRP, it is proposed to substitute the idea of maximum levels of contamination of water to the MPC. In the case of aquatic food chains (aquatic organisms and irrigated foodstuffs), the knowledge of the ingested quantities and of the concentration factors food/water permit to determinate these maximum levels, or to find out a linear relation between the maximum levels in the case of two primary carriers of contamination (continental and sea waters). The notion of critical food-consumption, critical radioelements and formula of waste disposal are considered in the same way, taking care to attach the greatest possible importance to local situations. (authors) [fr

  6. 40 CFR 141.13 - Maximum contaminant levels for turbidity.

    Science.gov (United States)

    2010-07-01

    ... turbidity. 141.13 Section 141.13 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER... Maximum contaminant levels for turbidity. The maximum contaminant levels for turbidity are applicable to... part. The maximum contaminant levels for turbidity in drinking water, measured at a representative...

  7. BfR recommends the establishment of a European maximum level for uranium in drinking and mineral water

    OpenAIRE

    German Federal Institute for Risk Assessment

    2007-01-01

    Uranium is a widespread, radioactive heavy metal on earth. It is to be found in varying concentrations and states in various rocks and minerals as well as in water, soil and air. Uranium may also reach the environment anthropogenically for instance in mineral phosphate fertilisers. Because of its widespread presence traces of uranium can also be detected in foods like drinking and mineral water. Uranium is not essential for humans. The ongoing intake of higher uranium concentration...

  8. Gaharu Leaf Extract Water Reduce MDA and 8-OHdG Levels and Increase Activities SOD and Catalase in Wistar Rats Provided Maximum Physical Activity

    Directory of Open Access Journals (Sweden)

    I Made Oka Adi Parwata

    2016-09-01

    Full Text Available Background: Oxidative stress occurs due to an imbalance of the number of free radicals by the number of endogenous antioxidant produced by the body i.e. Superoxide Dismutase (SOD, Gluthathione Peroxidase (GPx, and Catalase. The imbalance between the number of free radicals and antioxidants can be overcome with the endogenous antioxidant intake that exogenous oxidative stress can be reduced. One of exogenous antioxidants is natural Gaharu leaf water extract. Objective: This research focus on the effect of Gaharu leaf water extract in reducing MDA and 8-OHdG and increase the activity of SOD and Catalase. Methods: This study was an experimental with post only controls group design. Experiment was divided  into 5 groups of wistar rats, each consisting of 5 animals, i.e. negative control group without extract [K (-], treatment 1 treated 50 mg/kg BW/day of the extract (T1, treatment 2 treated 100 mg/kg BW/day of the extract (T2, treatment 3 treated 200 mg/ kg BW/day of the extract (T3, and positive control group [K (+] treated with vitamin Cat a dose 50 mg/kg BW/day. All groups treated for 10 weeks. Every day, before treatment, each group was given a maximum swimming activity for 1.5 hours for 10 weeks. ELISA was used to measure MDA, 8-OHdG, SOD, and Catalase activities. Result: The research results showed that treatment of extract of  leaves of Gaharu with an higher dose from 50 mg/kg BW up to 200 mg/ kg BW significantly decline (p <0.05 levels of MDA with the average ranging from 6.37±0.23, 5,56±0.27 and 4.32±0.27, 8-OHdG with a mean of 1.64±0.11, 1.26±0.46, and 1.09±0.17. On the other hand the treatment also increase SOD activity with less ranging from 12.15±1.04, 15.70±2.02, and 18.84±1.51, and Catalase ranging from 6,68±0.63, 8.20±1.14 and 9.29±0,79 in the blood of Wistar rats were given a maximum activity compared to the negative control group. This is probably higher phenol compounds (bioflavonoids quantity content of the extract

  9. 40 CFR 141.62 - Maximum contaminant levels for inorganic contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels for inorganic contaminants. 141.62 Section 141.62 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.62 Maximum...

  10. 40 CFR 141.63 - Maximum contaminant levels (MCLs) for microbiological contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels (MCLs) for microbiological contaminants. 141.63 Section 141.63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.63 Maximum...

  11. 40 CFR 141.61 - Maximum contaminant levels for organic contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels for organic contaminants. 141.61 Section 141.61 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER... Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.61 Maximum contaminant...

  12. Predicting location-specific extreme coastal floods in the future climate by introducing a probabilistic method to calculate maximum elevation of the continuous water mass caused by a combination of water level variations and wind waves

    Science.gov (United States)

    Leijala, Ulpu; Björkqvist, Jan-Victor; Johansson, Milla M.; Pellikka, Havu

    2017-04-01

    Future coastal management continuously strives for more location-exact and precise methods to investigate possible extreme sea level events and to face flooding hazards in the most appropriate way. Evaluating future flooding risks by understanding the behaviour of the joint effect of sea level variations and wind waves is one of the means to make more comprehensive flooding hazard analysis, and may at first seem like a straightforward task to solve. Nevertheless, challenges and limitations such as availability of time series of the sea level and wave height components, the quality of data, significant locational variability of coastal wave height, as well as assumptions to be made depending on the study location, make the task more complicated. In this study, we present a statistical method for combining location-specific probability distributions of water level variations (including local sea level observations and global mean sea level rise) and wave run-up (based on wave buoy measurements). The goal of our method is to obtain a more accurate way to account for the waves when making flooding hazard analysis on the coast compared to the approach of adding a separate fixed wave action height on top of sea level -based flood risk estimates. As a result of our new method, we gain maximum elevation heights with different return periods of the continuous water mass caused by a combination of both phenomena, "the green water". We also introduce a sensitivity analysis to evaluate the properties and functioning of our method. The sensitivity test is based on using theoretical wave distributions representing different alternatives of wave behaviour in relation to sea level variations. As these wave distributions are merged with the sea level distribution, we get information on how the different wave height conditions and shape of the wave height distribution influence the joint results. Our method presented here can be used as an advanced tool to minimize over- and

  13. 40 CFR 141.51 - Maximum contaminant level goals for inorganic contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant level goals for inorganic contaminants. 141.51 Section 141.51 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Level...

  14. 40 CFR 141.50 - Maximum contaminant level goals for organic contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant level goals for organic contaminants. 141.50 Section 141.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Level...

  15. 40 CFR 141.52 - Maximum contaminant level goals for microbiological contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant level goals for microbiological contaminants. 141.52 Section 141.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Level...

  16. Water Quality Assessment and Total Maximum Daily Loads Information (ATTAINS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Water Quality Assessment TMDL Tracking And Implementation System (ATTAINS) stores and tracks state water quality assessment decisions, Total Maximum Daily Loads...

  17. Maximum penetration level of distributed generation without violating voltage limits

    NARCIS (Netherlands)

    Morren, J.; Haan, de S.W.H.

    2009-01-01

    Connection of Distributed Generation (DG) units to a distribution network will result in a local voltage increase. As there will be a maximum on the allowable voltage increase, this will limit the maximum allowable penetration level of DG. By reactive power compensation (by the DG unit itself) a

  18. Heat Convection at the Density Maximum Point of Water

    Science.gov (United States)

    Balta, Nuri; Korganci, Nuri

    2018-01-01

    Water exhibits a maximum in density at normal pressure at around 4° degree temperature. This paper demonstrates that during cooling, at around 4 °C, the temperature remains constant for a while because of heat exchange associated with convective currents inside the water. Superficial approach implies it as a new anomaly of water, but actually it…

  19. Environmental Monitoring, Water Quality - Total Maximum Daily Load (TMDL)

    Data.gov (United States)

    NSGIC Education | GIS Inventory — The Clean Water Act Section 303(d) establishes the Total Maximum Daily Load (TMDL) program. The purpose of the TMDL program is to identify sources of pollution and...

  20. Scientific substantination of maximum allowable concentration of fluopicolide in water

    Directory of Open Access Journals (Sweden)

    Pelo I.М.

    2014-03-01

    Full Text Available In order to substantiate fluopicolide maximum allowable concentration in the water of water reservoirs the research was carried out. Methods of study: laboratory hygienic experiment using organoleptic and sanitary-chemical, sanitary-toxicological, sanitary-microbiological and mathematical methods. The results of fluopicolide influence on organoleptic properties of water, sanitary regimen of reservoirs for household purposes were given and its subthreshold concentration in water by sanitary and toxicological hazard index was calculated. The threshold concentration of the substance by the main hazard criteria was established, the maximum allowable concentration in water was substantiated. The studies led to the following conclusions: fluopicolide threshold concentration in water by organoleptic hazard index (limiting criterion – the smell – 0.15 mg/dm3, general sanitary hazard index (limiting criteria – impact on the number of saprophytic microflora, biochemical oxygen demand and nitrification – 0.015 mg/dm3, the maximum noneffective concentration – 0.14 mg/dm3, the maximum allowable concentration - 0.015 mg/dm3.

  1. Maximum surface level and temperature histories for Hanford waste tanks

    International Nuclear Information System (INIS)

    Flanagan, B.D.; Ha, N.D.; Huisingh, J.S.

    1994-01-01

    Radioactive defense waste resulting from the chemical processing of spent nuclear fuel has been accumulating at the Hanford Site since 1944. This waste is stored in underground waste-storage tanks. The Hanford Site Tank Farm Facilities Interim Safety Basis (ISB) provides a ready reference to the safety envelope for applicable tank farm facilities and installations. During preparation of the ISB, tank structural integrity concerns were identified as a key element in defining the safety envelope. These concerns, along with several deficiencies in the technical bases associated with the structural integrity issues and the corresponding operational limits/controls specified for conduct of normal tank farm operations are documented in the ISB. Consequently, a plan was initiated to upgrade the safety envelope technical bases by conducting Accelerated Safety Analyses-Phase 1 (ASA-Phase 1) sensitivity studies and additional structural evaluations. The purpose of this report is to facilitate the ASA-Phase 1 studies and future analyses of the single-shell tanks (SSTs) and double-shell tanks (DSTs) by compiling a quantitative summary of some of the past operating conditions the tanks have experienced during their existence. This report documents the available summaries of recorded maximum surface levels and maximum waste temperatures and references other sources for more specific data

  2. Water Level Station History

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Images contain station history information for 175 stations in the National Water Level Observation Network (NWLON). The NWLON is a network of long-term,...

  3. 40 CFR 141.66 - Maximum contaminant levels for radionuclides.

    Science.gov (United States)

    2010-07-01

    ... beta particle and photon radioactivity from man-made radionuclides in drinking water must not produce.../year). (2) Except for the radionuclides listed in table A, the concentration of man-made radionuclides... may make this technology too complex for small surface water systems. e Removal efficiencies can vary...

  4. The calculation of maximum permissible exposure levels for laser radiation

    International Nuclear Information System (INIS)

    Tozer, B.A.

    1979-01-01

    The maximum permissible exposure data of the revised standard BS 4803 are presented as a set of decision charts which ensure that the user automatically takes into account such details as pulse length and pulse pattern, limiting angular subtense, combinations of multiple wavelength and/or multiple pulse lengths, etc. The two decision charts given are for the calculation of radiation hazards to skin and eye respectively. (author)

  5. Water level detection pipeline

    International Nuclear Information System (INIS)

    Koshikawa, Yukinobu; Imanishi, Masatoshi; Niizato, Masaru; Takagi, Masahiro

    1998-01-01

    In the present invention, water levels of a feedwater heater and a drain tank in a nuclear power plant are detected at high accuracy. Detection pipeline headers connected to the upper and lower portions of a feedwater heater or a drain tank are connected with each other. The connection line is branched at appropriate two positions and an upper detection pipeline and a lower detection pipeline are connected thereto, and a gauge entrance valve is disposed to each of the detection pipelines. A diaphragm of a pressure difference generator is connected to a flange formed to the end portion. When detecting the change of water level in the feedwater heater or the drain tank as a change of pressure difference, gauge entrance valves on the exit side of the upper and lower detection pipelines are connected by a connection pipe. The gauge entrance valve is closed, a tube is connected to the lower detection pipe to inject water to the diaphragm of the pressure difference generator passing through the connection pipe thereby enabling to calibrate the pressure difference generator. The accuracy of the calibration of instruments is improved and workability thereof upon flange maintenance is also improved. (I.S.)

  6. Water level indicator

    International Nuclear Information System (INIS)

    Murase, Michio; Araki, Hidefumi.

    1996-01-01

    A difference of pressure between a standard pressure conduit in communication with a gas phase of a reactor pressure vessel and a water level pressure conduit in communication with a liquid phase of the pressure vessel is detected by a pressure difference gage. A communication pipe and a standard level vessel are disposed between the pressure vessel and the standard pressure conduit, and a standard liquid surface on the side of the standard pressure conduit is formed in the standard level vessel. A gas releaser is disposed to the gas phase portion of the standard level vessel. The gas releaser equipment is constituted by a porous material, a permeation membrane and a gas exhaustion hole. The gas phase of the standard level vessel is divided by a partition plate into a first gas phase being in contact with a connection portion with the communication pipe and a second gas phase in contact with the gas releaser. A gas flow channel hole and a condensate descending hole are disposed to the partition plate. Since incondensible gases accumulated to the standard level vessel are effectively exhausted, the incondensible gases are prevented from being dissolved into liquid. (I.N.)

  7. Reactor water level control device

    International Nuclear Information System (INIS)

    Hiramatsu, Yohei.

    1980-01-01

    Purpose: To increase the rapid response of the waterlevel control converting a reactor water level signal into a non-linear type, when the water level is near to a set value, to stabilize the water level reducting correlatively the reactor water level variation signal to stabilize greatly from the set value, and increasing the variation signal. Constitution: A main vapor flow quality transmitter detects the vapor flow generated in a reactor and introduced into a turbine. A feed water flow transmitter detects the quantity of a feed water flow from the turbine to the reactor, this detected value is sent to an addition operating apparatus. On the other hand, the power signal of the reactor water level transmitter is sent to the addition operating apparatus through a non-linear water level signal converter. The addition operation apparatus generates a signal for requesting the feed water flow quantity from both signals. Upon this occasion, the reactor water level signal converter makes small the reactor water level variation when the reactor level is close the set value, and when the water level deviates greatly from the set value, the reactor water level variation is made large thereby to improve the rapid response of the reactor coater level control. (Yoshino, Y.)

  8. The Red Sea during the Last Glacial Maximum: implications for sea level reconstructions

    Science.gov (United States)

    Gildor, H.; Biton, E.; Peltier, W. R.

    2006-12-01

    The Red Sea (RS) is a semi-enclosed basin connected to the Indian Ocean via a narrow and shallow strait, and surrounded by arid areas which exhibits high sensitivity to atmospheric changes and sea level reduction. We have used the MIT GCM to investigate the changes in the hydrography and circulation in the RS in response to reduced sea level, variability in the Indian monsoons, and changes in atmospheric temperature and humidity that occurred during the Last Glacial Maximum (LGM). The model results show high sensitivity to sea level reduction especially in the salinity field (increasing with the reduction in sea level) together with a mild atmospheric impact. Sea level reduction decreases the stratification, increases subsurface temperatures, and alters the circulation pattern at the Strait of Bab el Mandab, which experiences a transition from submaximal flow to maximal flow. The reduction in sea level at LGM alters the location of deep water formation which shifts to an open sea convective site in the northern part of the RS compared to present day situation in which deep water is formed from the Gulf of Suez outflow. Our main result based on both the GCM and on a simple hydraulic control model which takes into account mixing process at the Strait of Bab El Mandeb, is that sea level was reduced by only ~100 m in the Bab El Mandeb region during the LGM, i.e. the water depth at the Hanish sill (the shallowest part in the Strait Bab el Mandab) was around 34 m. This result agrees with the recent reconstruction of the LGM low stand of the sea in this region based upon the ICE-5G (VM2) model of Peltier (2004).

  9. Contribution to the study of maximum levels for liquid radioactive waste disposal into continental and sea water. Treatment of some typical samples; Contribution a l'etude des niveaux limites relatifs a des rejets d'effluents radioactifs liquides dans les eaux continentales et oceaniques. Traitement de quelques exemples types

    Energy Technology Data Exchange (ETDEWEB)

    Bittel, R; Mancel, J [Commissariat a l' Energie Atomique, 92 - Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires, departement de la protection sanitaire

    1968-10-01

    The most important carriers of radioactive contamination of man are the whole of foodstuffs and not only ingested water or inhaled air. That is the reason why, in accordance with the spirit of the recent recommendations of the ICRP, it is proposed to substitute the idea of maximum levels of contamination of water to the MPC. In the case of aquatic food chains (aquatic organisms and irrigated foodstuffs), the knowledge of the ingested quantities and of the concentration factors food/water permit to determinate these maximum levels, or to find out a linear relation between the maximum levels in the case of two primary carriers of contamination (continental and sea waters). The notion of critical food-consumption, critical radioelements and formula of waste disposal are considered in the same way, taking care to attach the greatest possible importance to local situations. (authors) [French] Les vecteurs essentiels de la contamination radioactive de l'homme sont les aliments dans leur ensemble, et non seulement l'eau ingeree ou l'air inhale. C'est pourquoi, en accord avec l'esprit des recentes recommandations de la C.I.P.R., il est propose de substituer aux CMA la notion de niveaux limites de contamination des eaux. Dans le cas des chaines alimentaires aquatiques (organismes aquatiques et aliments irrigues), la connaissance des quantites ingerees et celle des facteurs de concentration aliments/eau permettent de determiner ces niveaux limites dans le cas de deux vecteurs primaires de contamination (eaux continentales et eaux oceaniques). Les notions de regime alimentaire critique, de radioelement critique et de formule de rejets sont envisagees, dans le meme esprit, avec le souci de tenir compte le plus possible des situations locales. (auteurs)

  10. Chronological trends in maximum and minimum water flows of the Teesta River, Bangladesh, and its implications

    Directory of Open Access Journals (Sweden)

    Md. Sanaul H. Mondal

    2017-03-01

    Full Text Available Bangladesh shares a common border with India in the west, north and east and with Myanmar in the southeast. These borders cut across 57 rivers that discharge through Bangladesh into the Bay of Bengal in the south. The upstream courses of these rivers traverse India, China, Nepal and Bhutan. Transboundary flows are the important sources of water resources in Bangladesh. Among the 57 transboundary rivers, the Teesta is the fourth major river in Bangladesh after the Ganges, the Brahmaputra and the Meghna and Bangladesh occupies about 2071 km2 . The Teesta River floodplain in Bangladesh accounts for 14% of the total cropped area and 9.15 million people of the country. The objective of this study was to investigate trends in both maximum and minimum water flow at Kaunia and Dalia stations for the Teesta River and the coping strategies developed by the communities to adjust with uncertain flood situations. The flow characteristics of the Teesta were analysed by calculating monthly maximum and minimum water levels and discharges from 1985 to 2006. Discharge of the Teesta over the last 22 years has been decreasing. Extreme low-flow conditions were likely to occur more frequently after the implementation of the Gozoldoba Barrage by India. However, a very sharp decrease in peak flows was also observed albeit unexpected high discharge in 1988, 1989, 1991, 1997, 1999 and 2004 with some in between April and October. Onrush of water causes frequent flash floods, whereas decreasing flow leaves the areas dependent on the Teesta vulnerable to droughts. Both these extreme situations had a negative impact on the lives and livelihoods of people dependent on the Teesta. Over the years, people have developed several risk mitigation strategies to adjust with both natural and anthropogenic flood situations. This article proposed the concept of ‘MAXIN (maximum and minimum flows’ for river water justice for riparian land.

  11. Lake-level increasing under the climate cryoaridization conditions during the Last Glacial Maximum

    Science.gov (United States)

    Amosov, Mikhail; Strelkov, Ivan

    2017-04-01

    A lake genesis and lake-level increasing during the Last Glacial Maximum (LGM) are the paramount issues in paleoclimatology. Investigating these problems reveals the regularities of lake development and figures out an arid territory conditions at the LGM stage. Pluvial theory is the most prevalent conception of lake formation during the LGM. This theory is based on a fact that the water bodies emerged and their level increased due to torrential rainfalls. In this study, it is paid attention to an alternative assumption of lake genesis at the LGM stage, which is called climate cryoaridization. In accordance with this hypothesis, the endorheic water basins had their level enlarged because of a simultaneous climate aridity and temperature decrease. In this research, a lake-level increasing in endorheic regions of Central Asia and South American Altiplano of the Andes is described. The lake investigation is related to its conditions during the LGM. The study also includes a lake catalogue clearly presenting the basin conditions at the LGM stage and nowadays. The data compilation partly consists of information from an earlier work of Mikhail Amosov, Lake-levels, Vegetation And Climate In Central Asia During The Last Glacial Maximum (EGU2014-3015). According to the investigation, a lake catalogue on 27 lakes showed that most of the water bodies had higher level. This feature could be mentioned for the biggest lakes of the Aral Sea, Lake Balkhash, Issyk-Kul etc. and for the small ones located in the mountains, such as Pamir, Tian-Shan and Tibet. Yet some lakes that are situated in Central Asian periphery (Lake Qinghai and lakes in Inner Mongolia) used to be lower than nowadays. Also, the lake-level increasing of Altiplano turned to be a significant feature during the LGM in accordance with the data of 5 lakes, such as Titicaca, Coipasa-Uyuni, Lejia, Miscanti and Santa-Maria. Most of the current endorheic basins at the LGM stage were filled with water due to abundant

  12. An Iterative Maximum a Posteriori Estimation of Proficiency Level to Detect Multiple Local Likelihood Maxima

    Science.gov (United States)

    Magis, David; Raiche, Gilles

    2010-01-01

    In this article the authors focus on the issue of the nonuniqueness of the maximum likelihood (ML) estimator of proficiency level in item response theory (with special attention to logistic models). The usual maximum a posteriori (MAP) method offers a good alternative within that framework; however, this article highlights some drawbacks of its…

  13. Reactor water level control device

    International Nuclear Information System (INIS)

    Utagawa, Kazuyuki.

    1993-01-01

    A device of the present invention can effectively control fluctuation of a reactor water level upon power change by reactor core flow rate control operation. That is, (1) a feedback control section calculates a feedwater flow rate control amount based on a deviation between a set value of a reactor water level and a reactor water level signal. (2) a feed forward control section forecasts steam flow rate change based on a reactor core flow rate signal or a signal determining the reactor core flow rate, to calculate a feedwater flow rate control amount which off sets the steam flow rate change. Then, the sum of the output signal from the process (1) and the output signal from the process (2) is determined as a final feedwater flow rate control signal. With such procedures, it is possible to forecast the steam flow rate change accompanying the reactor core flow rate control operation, thereby enabling to conduct preceding feedwater flow rate control operation which off sets the reactor water level fluctuation based on the steam flow rate change. Further, a reactor water level deviated from the forecast can be controlled by feedback control. Accordingly, reactor water level fluctuation upon power exchange due to the reactor core flow rate control operation can rapidly be suppressed. (I.S.)

  14. Influence of aliphatic amides on the temperature of maximum density of water

    International Nuclear Information System (INIS)

    Torres, Andrés Felipe; Romero, Carmen M.

    2017-01-01

    Highlights: • The addition of amides decreases the temperature of maximum density of water suggesting a disruptive effect on water structure. • The amides in aqueous solution do not follow the Despretz equation in the concentration range considered. • The temperature shift Δθ as a function of molality is represented by a second order equation. • The Despretz constants were determined considering the dilute concentration region for each amide solution. • Solute disrupting effect of amides becomes smaller as its hydrophobic character increases. - Abstract: The influence of dissolved substances on the temperature of the maximum density of water has been studied in relation to their effect on water structure as they can change the equilibrium between structured and unstructured species of water. However, most work has been performed using salts and the studies with small organic solutes such as amides are scarce. In this work, the effect of acetamide, propionamide and butyramide on the temperature of maximum density of water was determined from density measurements using a magnetic float densimeter. Densities of aqueous solutions were measured within the temperature range from T = (275.65–278.65) K at intervals of 0.50 K in the concentration range between (0.10000 and 0.80000) mol·kg −1 . The temperature of maximum density was determined from the experimental results. The effect of the three amides is to decrease the temperature of maximum density of water and the change does not follow the Despretz equation. The results are discussed in terms of solute-water interactions and the disrupting effect of amides on water structure.

  15. Distribution of Snow and Maximum Snow Water Equivalent Obtained by LANDSAT Data and Degree Day Method

    Science.gov (United States)

    Takeda, K.; Ochiai, H.; Takeuchi, S.

    1985-01-01

    Maximum snow water equivalence and snowcover distribution are estimated using several LANDSAT data taken in snowmelting season over a four year period. The test site is Okutadami-gawa Basin located in the central position of Tohoku-Kanto-Chubu District. The year to year normalization for snowmelt volume computation on the snow line is conducted by year to year correction of degree days using the snowcover percentage within the test basin obtained from LANDSAT data. The maximum snow water equivalent map in the test basin is generated based on the normalized snowmelt volume on the snow line extracted from four LANDSAT data taken in a different year. The snowcover distribution on an arbitrary day in snowmelting of 1982 is estimated from the maximum snow water equivalent map. The estimated snowcover is compared with the snowcover area extracted from NOAA-AVHRR data taken on the same day. The applicability of the snow estimation using LANDSAT data is discussed.

  16. Efeito de níveis de água, coberturas do solo e condições ambientais na temperatura do solo e no cultivo de morangueiro em ambiente protegido e a céu aberto Effect of water levels, soil covers and enviroment in maximum soil temperature in strawberry crop in field and greenhouse

    Directory of Open Access Journals (Sweden)

    Regina C. de M. Pires

    2004-12-01

    Full Text Available A temperatura do solo é um importante parâmetro no cultivo do morangueiro, pois interfere no desenvolvimento vegetativo, na sanidade e na produção. O objetivo do presente trabalho foi avaliar o efeito de diferentes níveis de água, coberturas de canteiro em campo aberto e em ambiente protegido, na temperatura máxima do solo no cultivo do morangueiro. Foram realizados dois experimentos: um em cultivo protegido e outro a campo aberto, em Atibaia - SP, em esquema fatorial 2 x 3 (coberturas do solo e níveis de irrigação, em blocos ao acaso, com cinco repetições. As coberturas de solo utilizadas foram filmes de polietileno preto e transparente. A irrigação localizada foi aplicada por gotejo sempre que o potencial de água no solo atingisse -0,010 (N1, -0,035 (N2 e -0,070 (N3 MPa, em tensiômetros instalados a 10 cm de profundidade. A temperatura do solo foi avaliada por termógrafos, sendo os sensores instalados a 5 cm de profundidade. Houve influência do ambiente de cultivo, da cobertura do solo e dos níveis de irrigação na temperatura máxima do solo. A temperatura do solo sob diferentes coberturas dependeu não somente das características físicas do plástico, como também da forma de instalação no canteiro. A temperatura máxima do solo aumentou com a diminuição do potencial da água no solo, no momento da irrigação.The soil temperature is an important parameter in strawberry crop, because, it interferes in vegetative development, plant health conditions and yield. The aim of this work was to evaluate the effect of different water levels, soil covers in field conditions and greenhouse in maximum soil temperature in strawberry crop. Two experiments were accomplished, one in greenhouse and other in field conditions, at Atibaia - SP, Brazil. The experimental design was a factorial 2 x 3 (soil covers and water levels, with 5 repetitions. The soil covers were clear and black plastics. The trickle irrigation was applied

  17. Changes in the Global Hydrological Cycle: Lessons from Modeling Lake Levels at the Last Glacial Maximum

    Science.gov (United States)

    Lowry, D. P.; Morrill, C.

    2011-12-01

    Geologic evidence shows that lake levels in currently arid regions were higher and lakes in currently wet regions were lower during the Last Glacial Maximum (LGM). Current hypotheses used to explain these lake level changes include the thermodynamic hypothesis, in which decreased tropospheric water vapor coupled with patterns of convergence and divergence caused dry areas to become more wet and vice versa, the dynamic hypothesis, in which shifts in the jet stream and Inter-Tropical Convergence Zone (ITCZ) altered precipitation patterns, and the evaporation hypothesis, in which lake expansions are attributed to reduced evaporation in a colder climate. This modeling study uses the output of four climate models participating in phase 2 of the Paleoclimate Modeling Intercomparison Project (PMIP2) as input into a lake energy-balance model, in order to test the accuracy of the models and understand the causes of lake level changes. We model five lakes which include the Great Basin lakes, USA; Lake Petén Itzá, Guatemala; Lake Caçó, northern Brazil; Lake Tauca (Titicaca), Bolivia and Peru; and Lake Cari-Laufquen, Argentina. These lakes create a transect through the drylands of North America through the tropics and to the drylands of South America. The models accurately recreate LGM conditions in 14 out of 20 simulations, with the Great Basin lakes being the most robust and Lake Caçó being the least robust, due to model biases in portraying the ITCZ over South America. An analysis of the atmospheric moisture budget from one of the climate models shows that thermodynamic processes contribute most significantly to precipitation changes over the Great Basin, while dynamic processes are most significant for the other lakes. Lake Cari-Laufquen shows a lake expansion that is most likely attributed to reduced evaporation rather than changes in regional precipitation, suggesting that lake levels alone may not be the best indicator of how much precipitation this region

  18. The Influence of Red Fruit Oil on Creatin Kinase Level at Maximum Physical Activity

    Science.gov (United States)

    Apollo Sinaga, Fajar; Hotliber Purba, Pangondian

    2018-03-01

    Heavy physical activities can cause the oxidative stress which resulting in muscle damage with an indicator of elevated levels of Creatin Kinase (CK) enzyme. The oxidative stress can be prevented or reduced by antioxidant supplementation. One of natural resources which contain antioxidant is Red Fruit (Pandanus conoideus) Oil (RFO). This study aims to see the effect of Red Fruit Oil on Creatin Kinase (CK) level at maximum physical activity. This study is an experimental research by using the design of randomized control group pretest-posttest. This study was using 24 male mice divided into four groups, the control group was given aquadest, the treatment groups P1, P2, and P3 were given the RFO orally of 0.15 ml/kgBW, 0.3 ml/kgBW, and 0.6 ml/kgBW, respectively, for a month. The level of CK was checked for all groups at the beginning of study and after the maximum physical activity. The obtained data were then tested statistically by using t-test and ANOVA. The result shows the RFO supplementation during exercise decreased the CK level in P1, P2, and P3 groups with p<0.05, and the higher RFO dosage resulted in decreased CK level at p<0.05. The conclusion of this study is the Red Fruit Oil could decrease the level of CK at maximum physical activity.

  19. Three-level grid-connected photovoltaic inverter with maximum power point tracking

    International Nuclear Information System (INIS)

    Tsang, K.M.; Chan, W.L.

    2013-01-01

    Highlight: ► This paper reports a novel 3-level grid connected photovoltaic inverter. ► The inverter features maximum power point tracking and grid current shaping. ► The inverter can be acted as an active filter and a renewable power source. - Abstract: This paper presents a systematic way of designing control scheme for a grid-connected photovoltaic (PV) inverter featuring maximum power point tracking (MPPT) and grid current shaping. Unlike conventional design, only four power switches are required to achieve three output levels and it is not necessary to use any phase-locked-loop circuitry. For the proposed scheme, a simple integral controller has been designed for the tracking of the maximum power point of a PV array based on an improved extremum seeking control method. For the grid-connected inverter, a current loop controller and a voltage loop controller have been designed. The current loop controller is designed to shape the inverter output current while the voltage loop controller can maintain the capacitor voltage at a certain level and provide a reference inverter output current for the PV inverter without affecting the maximum power point of the PV array. Experimental results are included to demonstrate the effectiveness of the tracking and control scheme.

  20. Maximum power point tracking techniques for wind energy systems using three levels boost converter

    Science.gov (United States)

    Tran, Cuong Hung; Nollet, Frédéric; Essounbouli, Najib; Hamzaoui, Abdelaziz

    2018-05-01

    This paper presents modeling and simulation of three level Boost DC-DC converter in Wind Energy Conversion System (WECS). Three-level Boost converter has significant advantage compared to conventional Boost. A maximum power point tracking (MPPT) method for a variable speed wind turbine using permanent magnet synchronous generator (PMSG) is also presented. Simulation of three-level Boost converter topology with Perturb and Observe algorithm and Fuzzy Logic Control is implemented in MATLAB/SIMULINK. Results of this simulation show that the system with MPPT using fuzzy logic controller has better performance to the Perturb and Observe algorithm: fast response under changing conditions and small oscillation.

  1. 25(OHD3 Levels Relative to Muscle Strength and Maximum Oxygen Uptake in Athletes

    Directory of Open Access Journals (Sweden)

    Książek Anna

    2016-04-01

    Full Text Available Vitamin D is mainly known for its effects on the bone and calcium metabolism. The discovery of Vitamin D receptors in many extraskeletal cells suggests that it may also play a significant role in other organs and systems. The aim of our study was to assess the relationship between 25(OHD3 levels, lower limb isokinetic strength and maximum oxygen uptake in well-trained professional football players. We enrolled 43 Polish premier league soccer players. The mean age was 22.7±5.3 years. Our study showed decreased serum 25(OHD3 levels in 74.4% of the professional players. The results also demonstrated a lack of statistically significant correlation between 25(OHD3 levels and lower limb muscle strength with the exception of peak torque of the left knee extensors at an angular velocity of 150°/s (r=0.41. No significant correlations were found between hand grip strength and maximum oxygen uptake. Based on our study we concluded that in well-trained professional soccer players, there was no correlation between serum levels of 25(OHD3 and muscle strength or maximum oxygen uptake.

  2. Designing water supplies: Optimizing drinking water composition for maximum economic benefit

    DEFF Research Database (Denmark)

    Rygaard, Martin; Arvin, Erik; Bath, A.

    2011-01-01

    to water quality aspects, costs of water production, fresh water abstraction and CO2-emissions are integrated into a holistic economic assessment of the optimum share of desalinated water in water supplies. Results show that carefully designed desalination post-treatment can have net benefits up to €0.......3 ± 0.2 per delivered m3 for Perth and €0.4(±0.2) for Copenhagen. Costs of remineralization and green house gas emission mitigation are minor when compared to the potential benefits of an optimum water composition. Finally, a set of optimum water quality criteria is proposed for the guidance of water...... includes modeling of possible water quality blends and an evaluation of corrosion indices. Based on concentration-response relationships a range of impacts on public health, material lifetimes and consumption of soap have been valued for Perth, Western Australia and Copenhagen, Denmark. In addition...

  3. Reactor water level measuring device

    International Nuclear Information System (INIS)

    Kuroki, Reiji; Asano, Tamotsu.

    1996-01-01

    A condensation vessel is connected to the upper portion of a reactor pressure vessel by way of a pipeline. The lower portion of the condensation vessel is connected to a low pressure side of a differential pressure transmission device by way of a reference leg pipeline. The high pressure side of the differential pressure transmission device is connected to the lower portion of the pressure vessel by way of a pipeline. The condensation vessel is equipped with a temperature sensor. When a temperature of a gas phase portion in the condensation vessel is lowered below a predetermined level, and incondensible gases in the condensation vessel starts to be dissolved in water, signals are sent from the temperature sensor to a control device and a control valve is opened. With such a constitution, CRD driving water flows into the condensation vessel, and water in which gases at the upper portion of the condensation vessel is dissolved flows into the pressure vessel by way of a pipeline. Then, gases dissolved in a reference water column in the reference leg pipeline are eliminated and the value of a reference water pressure does not change even upon abrupt lowering of pressure. (I.N.)

  4. Level set segmentation of medical images based on local region statistics and maximum a posteriori probability.

    Science.gov (United States)

    Cui, Wenchao; Wang, Yi; Lei, Tao; Fan, Yangyu; Feng, Yan

    2013-01-01

    This paper presents a variational level set method for simultaneous segmentation and bias field estimation of medical images with intensity inhomogeneity. In our model, the statistics of image intensities belonging to each different tissue in local regions are characterized by Gaussian distributions with different means and variances. According to maximum a posteriori probability (MAP) and Bayes' rule, we first derive a local objective function for image intensities in a neighborhood around each pixel. Then this local objective function is integrated with respect to the neighborhood center over the entire image domain to give a global criterion. In level set framework, this global criterion defines an energy in terms of the level set functions that represent a partition of the image domain and a bias field that accounts for the intensity inhomogeneity of the image. Therefore, image segmentation and bias field estimation are simultaneously achieved via a level set evolution process. Experimental results for synthetic and real images show desirable performances of our method.

  5. Maximum solid concentrations of coal water slurries predicted by neural network models

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Jun; Li, Yanchang; Zhou, Junhu; Liu, Jianzhong; Cen, Kefa

    2010-12-15

    The nonlinear back-propagation (BP) neural network models were developed to predict the maximum solid concentration of coal water slurry (CWS) which is a substitute for oil fuel, based on physicochemical properties of 37 typical Chinese coals. The Levenberg-Marquardt algorithm was used to train five BP neural network models with different input factors. The data pretreatment method, learning rate and hidden neuron number were optimized by training models. It is found that the Hardgrove grindability index (HGI), moisture and coalification degree of parent coal are 3 indispensable factors for the prediction of CWS maximum solid concentration. Each BP neural network model gives a more accurate prediction result than the traditional polynomial regression equation. The BP neural network model with 3 input factors of HGI, moisture and oxygen/carbon ratio gives the smallest mean absolute error of 0.40%, which is much lower than that of 1.15% given by the traditional polynomial regression equation. (author)

  6. Soil and Water Assessment Tool model predictions of annual maximum pesticide concentrations in high vulnerability watersheds.

    Science.gov (United States)

    Winchell, Michael F; Peranginangin, Natalia; Srinivasan, Raghavan; Chen, Wenlin

    2018-05-01

    Recent national regulatory assessments of potential pesticide exposure of threatened and endangered species in aquatic habitats have led to increased need for watershed-scale predictions of pesticide concentrations in flowing water bodies. This study was conducted to assess the ability of the uncalibrated Soil and Water Assessment Tool (SWAT) to predict annual maximum pesticide concentrations in the flowing water bodies of highly vulnerable small- to medium-sized watersheds. The SWAT was applied to 27 watersheds, largely within the midwest corn belt of the United States, ranging from 20 to 386 km 2 , and evaluated using consistent input data sets and an uncalibrated parameterization approach. The watersheds were selected from the Atrazine Ecological Exposure Monitoring Program and the Heidelberg Tributary Loading Program, both of which contain high temporal resolution atrazine sampling data from watersheds with exceptionally high vulnerability to atrazine exposure. The model performance was assessed based upon predictions of annual maximum atrazine concentrations in 1-d and 60-d durations, predictions critical in pesticide-threatened and endangered species risk assessments when evaluating potential acute and chronic exposure to aquatic organisms. The simulation results showed that for nearly half of the watersheds simulated, the uncalibrated SWAT model was able to predict annual maximum pesticide concentrations within a narrow range of uncertainty resulting from atrazine application timing patterns. An uncalibrated model's predictive performance is essential for the assessment of pesticide exposure in flowing water bodies, the majority of which have insufficient monitoring data for direct calibration, even in data-rich countries. In situations in which SWAT over- or underpredicted the annual maximum concentrations, the magnitude of the over- or underprediction was commonly less than a factor of 2, indicating that the model and uncalibrated parameterization

  7. Multi-level restricted maximum likelihood covariance estimation and kriging for large non-gridded spatial datasets

    KAUST Repository

    Castrillon, Julio; Genton, Marc G.; Yokota, Rio

    2015-01-01

    We develop a multi-level restricted Gaussian maximum likelihood method for estimating the covariance function parameters and computing the best unbiased predictor. Our approach produces a new set of multi-level contrasts where the deterministic

  8. An event- and network-level analysis of college students' maximum drinking day.

    Science.gov (United States)

    Meisel, Matthew K; DiBello, Angelo M; Balestrieri, Sara G; Ott, Miles Q; DiGuiseppi, Graham T; Clark, Melissa A; Barnett, Nancy P

    2018-04-01

    Heavy episodic drinking is common among college students and remains a serious public health issue. Previous event-level research among college students has examined behaviors and individual-level characteristics that drive consumption and related consequences but often ignores the social network of people with whom these heavy drinking episodes occur. The main aim of the current study was to investigate the network of social connections between drinkers on their heaviest drinking occasions. Sociocentric network methods were used to collect information from individuals in the first-year class (N=1342) at one university. Past-month drinkers (N=972) reported on the characteristics of their heaviest drinking occasion in the past month and indicated who else among their network connections was present during this occasion. Average max drinking day indegree, or the total number of times a participant was nominated as being present on another students' heaviest drinking occasion, was 2.50 (SD=2.05). Network autocorrelation models indicated that max drinking day indegree (e.g., popularity on heaviest drinking occassions) and peers' number of drinks on their own maximum drinking occasions were significantly associated with participant maximum number of drinks, after controlling for demographic variables, pregaming, and global network indegree (e.g., popularity in the entire first-year class). Being present at other peers' heaviest drinking occasions is associated with greater drinking quantities on one's own heaviest drinking occasion. These findings suggest the potential for interventions that target peer influences within close social networks of drinkers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Maximum flood hazard assessment for OPG's deep geologic repository for low and intermediate level waste

    International Nuclear Information System (INIS)

    Nimmrichter, P.; McClintock, J.; Peng, J.; Leung, H.

    2011-01-01

    Ontario Power Generation (OPG) has entered a process to seek Environmental Assessment and licensing approvals to construct a Deep Geologic Repository (DGR) for Low and Intermediate Level Radioactive Waste (L&ILW) near the existing Western Waste Management Facility (WWMF) at the Bruce nuclear site in the Municipality of Kincardine, Ontario. In support of the design of the proposed DGR project, maximum flood stages were estimated for potential flood hazard risks associated with coastal, riverine and direct precipitation flooding. The estimation of lake/coastal flooding for the Bruce nuclear site considered potential extreme water levels in Lake Huron, storm surge and seiche, wind waves, and tsunamis. The riverine flood hazard assessment considered the Probable Maximum Flood (PMF) within the local watersheds, and within local drainage areas that will be directly impacted by the site development. A series of hydraulic models were developed, based on DGR project site grading and ditching, to assess the impact of a Probable Maximum Precipitation (PMP) occurring directly at the DGR site. Overall, this flood assessment concluded there is no potential for lake or riverine based flooding and the DGR area is not affected by tsunamis. However, it was also concluded from the results of this analysis that the PMF in proximity to the critical DGR operational areas and infrastructure would be higher than the proposed elevation of the entrance to the underground works. This paper provides an overview of the assessment of potential flood hazard risks associated with coastal, riverine and direct precipitation flooding that was completed for the DGR development. (author)

  10. THE 2003 -2007 MINIMUM, MAXIMUM AND MEDIUM DISCHARGE ANALYSIS OF THE LATORIŢA-LOTRU WATER SYSTEM

    Directory of Open Access Journals (Sweden)

    Simona-Elena MIHĂESCU

    2010-06-01

    Full Text Available The 2003 -2007 minimum, maximum and medium discharge analysis of the Latoriţa-Lotru water system From a functional point of view, the Lotru and Latoriţa make up a water system by the junction of the two high hydro energetic potential water flows. The Lotru springs from the Parâng Massif with a spring quota of over 1900m and an outfall quota of 298m, which makes for an altitude difference of 1602m; it is the affluent of the Olt River, has a course length of 76 km and a minimum discharge of 20m3/s. Its reception hollow is of 1024 km2. Latoriţa springs from the Latoriţa Mountains, it is a small river with an average discharge of 2.7m3/s and is an affluent of the Lotru. Together, the two make up a high hydro energetic potential system, valorized in the system of lakes which serve the Ciunget Hydro-Electric Power Plant. Galbenu and Petrimanu are two reservoirs built on the Latoriţa River and on the Lotru, we have Vidra reservoir, Balindru, Mălaia and Brădişor. The discharge analysis of these rivers is very important in view of a good risk management, especially consisting in floods and high level waters, even in the case of artificial water flows such as the Latoriţa-Lotru water system.

  11. A mesic maximum in biological water use demarcates biome sensitivity to aridity shifts.

    Science.gov (United States)

    Good, Stephen P; Moore, Georgianne W; Miralles, Diego G

    2017-12-01

    Biome function is largely governed by how efficiently available resources can be used and yet for water, the ratio of direct biological resource use (transpiration, E T ) to total supply (annual precipitation, P) at ecosystem scales remains poorly characterized. Here, we synthesize field, remote sensing and ecohydrological modelling estimates to show that the biological water use fraction (E T /P) reaches a maximum under mesic conditions; that is, when evaporative demand (potential evapotranspiration, E P ) slightly exceeds supplied precipitation. We estimate that this mesic maximum in E T /P occurs at an aridity index (defined as E P /P) between 1.3 and 1.9. The observed global average aridity of 1.8 falls within this range, suggesting that the biosphere is, on average, configured to transpire the largest possible fraction of global precipitation for the current climate. A unimodal E T /P distribution indicates that both dry regions subjected to increasing aridity and humid regions subjected to decreasing aridity will suffer declines in the fraction of precipitation that plants transpire for growth and metabolism. Given the uncertainties in the prediction of future biogeography, this framework provides a clear and concise determination of ecosystems' sensitivity to climatic shifts, as well as expected patterns in the amount of precipitation that ecosystems can effectively use.

  12. Sea-Level Change in the Russian Arctic Since the Last Glacial Maximum

    Science.gov (United States)

    Horton, B.; Baranskaya, A.; Khan, N.; Romanenko, F. A.

    2017-12-01

    Relative sea-level (RSL) databases that span the Last Glacial Maximum (LGM) to present have been used to infer changes in climate, regional ice sheet variations, the rate and geographic source of meltwater influx, and the rheological structure of the solid Earth. Here, we have produced a quality-controlled RSL database for the Russian Arctic since the LGM. The database contains 394 index points, which locate the position of RSL in time and space, and 244 limiting points, which constrain the minimum or maximum limit of former sea level. In the western part of the Russian Arctic (Barents and White seas,) RSL was driven by glacial isostatic adjustment (GIA) due to deglaciation of the Scandinavian ice sheet, which covered the Baltic crystalline shield at the LGM. RSL data from isolation basins show rapid RSL from 80-100 m at 11-12 ka BP to 15-25 m at 4-5 ka BP. In the Arctic Islands of Franz-Joseph Land and Novaya Zemlya, RSL data from dated driftwood in raised beaches show a gradual fall from 25-35 m at 9-10 ka BP to 5-10 m at 3 ka BP. In the Russian plain, situated at the margins of the formerly glaciated Baltic crystalline shield, RSL data from raised beaches and isolation basins show an early Holocene rise from less than -20 m at 9-11 ka BP before falling in the late Holocene, illustrating the complex interplay between ice-equivalent meltwater input and GIA. The Western Siberian Arctic (Yamal and Gydan Peninsulas, Beliy Island and islands of the Kara Sea) was not glaciated at the LGM. Sea-level data from marine and salt-marsh deposits show RSL rise at the beginning of the Holocene to a mid-Holocene highstand of 1-5 m at 5-1 ka BP. A similar, but more complex RSL pattern is shown for Eastern Siberia. RSL data from the Laptev Sea shelf show RSL at -40- -45 m and 11-14 ka BP. RSL data from the Lena Delta and Tiksi region have a highstand from 5 to 1 ka BP. The research is supported by RSF project 17-77-10130

  13. Experimental verification of the imposing principle for maximum permissible levels of multicolor laser radiation

    Directory of Open Access Journals (Sweden)

    Ivashin V.A.

    2013-12-01

    Full Text Available Aims. The study presents the results of experimental research to verify the principle overlay for maximum permissible levels (MPL of multicolor laser radiation single exposure on eyes. This principle of the independence of the effects of radiation with each wavelength (the imposing principle, was founded and generalized to a wide range of exposure conditions. Experimental verification of this approach in relation to the impact of laser radiation on tissue fundus of an eye, as shows the analysis of the literature was not carried out. Material and methods. Was used in the experimental laser generating radiation with wavelengths: Л1 =0,532 microns, A2=0,556to 0,562 microns and A3=0,619to 0,621 urn. Experiments were carried out on eyes of rabbits with evenly pigmented eye bottom. Results. At comparison of results of processing of the experimental data with the calculated data it is shown that these levels are close by their parameters. Conclusions. For the first time in the Russian Federation had been performed experimental studies on the validity of multi-colored laser radiation on the organ of vision. In view of the objective coincidence of the experimental data with the calculated data, we can conclude that the mathematical formulas work.

  14. Water level monitoring device in nuclear reactor

    International Nuclear Information System (INIS)

    Miura, Kiyohide; Otake, Tomohiro.

    1988-01-01

    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.)

  15. Minimum and Maximum Potential Contributions to Future Sea Level Rise from Polar Ice Sheets

    Science.gov (United States)

    Deconto, R. M.; Pollard, D.

    2017-12-01

    New climate and ice-sheet modeling, calibrated to past changes in sea-level, is painting a stark picture of the future fate of the great polar ice sheets if greenhouse gas emissions continue unabated. This is especially true for Antarctica, where a substantial fraction of the ice sheet rests on bedrock more than 500-meters below sea level. Here, we explore the sensitivity of the polar ice sheets to a warming atmosphere and ocean under a range of future greenhouse gas emissions scenarios. The ice sheet-climate-ocean model used here considers time-evolving changes in surface mass balance and sub-ice oceanic melting, ice deformation, grounding line retreat on reverse-sloped bedrock (Marine Ice Sheet Instability), and newly added processes including hydrofracturing of ice shelves in response to surface meltwater and rain, and structural collapse of thick, marine-terminating ice margins with tall ice-cliff faces (Marine Ice Cliff Instability). The simulations improve on previous work by using 1) improved atmospheric forcing from a Regional Climate Model and 2) a much wider range of model physical parameters within the bounds of modern observations of ice dynamical processes (particularly calving rates) and paleo constraints on past ice-sheet response to warming. Approaches to more precisely define the climatic thresholds capable of triggering rapid and potentially irreversible ice-sheet retreat are also discussed, as is the potential for aggressive mitigation strategies like those discussed at the 2015 Paris Climate Conference (COP21) to substantially reduce the risk of extreme sea-level rise. These results, including physics that consider both ice deformation (creep) and calving (mechanical failure of marine terminating ice) expand on previously estimated limits of maximum rates of future sea level rise based solely on kinematic constraints of glacier flow. At the high end, the new results show the potential for more than 2m of global mean sea level rise by 2100

  16. Quantile-based Bayesian maximum entropy approach for spatiotemporal modeling of ambient air quality levels.

    Science.gov (United States)

    Yu, Hwa-Lung; Wang, Chih-Hsin

    2013-02-05

    Understanding the daily changes in ambient air quality concentrations is important to the assessing human exposure and environmental health. However, the fine temporal scales (e.g., hourly) involved in this assessment often lead to high variability in air quality concentrations. This is because of the complex short-term physical and chemical mechanisms among the pollutants. Consequently, high heterogeneity is usually present in not only the averaged pollution levels, but also the intraday variance levels of the daily observations of ambient concentration across space and time. This characteristic decreases the estimation performance of common techniques. This study proposes a novel quantile-based Bayesian maximum entropy (QBME) method to account for the nonstationary and nonhomogeneous characteristics of ambient air pollution dynamics. The QBME method characterizes the spatiotemporal dependence among the ambient air quality levels based on their location-specific quantiles and accounts for spatiotemporal variations using a local weighted smoothing technique. The epistemic framework of the QBME method can allow researchers to further consider the uncertainty of space-time observations. This study presents the spatiotemporal modeling of daily CO and PM10 concentrations across Taiwan from 1998 to 2009 using the QBME method. Results show that the QBME method can effectively improve estimation accuracy in terms of lower mean absolute errors and standard deviations over space and time, especially for pollutants with strong nonhomogeneous variances across space. In addition, the epistemic framework can allow researchers to assimilate the site-specific secondary information where the observations are absent because of the common preferential sampling issues of environmental data. The proposed QBME method provides a practical and powerful framework for the spatiotemporal modeling of ambient pollutants.

  17. Sea level and global ice volumes from the Last Glacial Maximum to the Holocene.

    Science.gov (United States)

    Lambeck, Kurt; Rouby, Hélène; Purcell, Anthony; Sun, Yiying; Sambridge, Malcolm

    2014-10-28

    The major cause of sea-level change during ice ages is the exchange of water between ice and ocean and the planet's dynamic response to the changing surface load. Inversion of ∼1,000 observations for the past 35,000 y from localities far from former ice margins has provided new constraints on the fluctuation of ice volume in this interval. Key results are: (i) a rapid final fall in global sea level of ∼40 m in sea level, the main phase of deglaciation occurred from ∼16.5 ka BP to ∼8.2 ka BP at an average rate of rise of 12 m⋅ka(-1) punctuated by periods of greater, particularly at 14.5-14.0 ka BP at ≥40 mm⋅y(-1) (MWP-1A), and lesser, from 12.5 to 11.5 ka BP (Younger Dryas), rates; (iv) no evidence for a global MWP-1B event at ∼11.3 ka BP; and (v) a progressive decrease in the rate of rise from 8.2 ka to ∼2.5 ka BP, after which ocean volumes remained nearly constant until the renewed sea-level rise at 100-150 y ago, with no evidence of oscillations exceeding ∼15-20 cm in time intervals ≥200 y from 6 to 0.15 ka BP.

  18. Guidance document on the derivation of maximum permissible risk levels for human intake of soil contaminants

    NARCIS (Netherlands)

    Janssen PJCM; Speijers GJA; CSR

    1997-01-01

    This report contains a basic step-to-step description of the procedure followed in the derivation of the human-toxicological Maximum Permissible Risk (MPR ; in Dutch: Maximum Toelaatbaar Risico, MTR) for soil contaminants. In recent years this method has been applied for a large number of compounds

  19. Estimating safe maximum levels of vitamins and minerals in fortified foods and food supplements.

    Science.gov (United States)

    Flynn, Albert; Kehoe, Laura; Hennessy, Áine; Walton, Janette

    2017-12-01

    To show how safe maximum levels (SML) of vitamins and minerals in fortified foods and supplements may be estimated in population subgroups. SML were estimated for adults and 7- to 10-year-old children for six nutrients (retinol, vitamins B6, D and E, folic acid, iron and calcium) using data on usual daily nutrient intakes from Irish national nutrition surveys. SML of nutrients in supplements were lower for children than for adults, except for calcium and iron. Daily energy intake from fortified foods in high consumers (95th percentile) varied by nutrient from 138 to 342 kcal in adults and 40-309 kcal in children. SML (/100 kcal) of nutrients in fortified food were lower for children than adults for vitamins B6 and D, higher for vitamin E, with little difference for other nutrients. Including 25 % 'overage' for nutrients in fortified foods and supplements had little effect on SML. Nutritionally significant amounts of these nutrients can be added safely to supplements and fortified foods for these population subgroups. The estimated SML of nutrients in fortified foods and supplements may be considered safe for these population subgroups over the long term given the food composition and dietary patterns prevailing in the respective dietary surveys. This risk assessment approach shows how nutrient intake data may be used to estimate, for population subgroups, the SML for vitamins and minerals in both fortified foods and supplements, separately, each taking into account the intake from other dietary sources.

  20. A local maximum in gibberellin levels regulates maize leaf growth by spatial control of cell division.

    Science.gov (United States)

    Nelissen, Hilde; Rymen, Bart; Jikumaru, Yusuke; Demuynck, Kirin; Van Lijsebettens, Mieke; Kamiya, Yuji; Inzé, Dirk; Beemster, Gerrit T S

    2012-07-10

    Plant growth rate is largely determined by the transition between the successive phases of cell division and expansion. A key role for hormone signaling in determining this transition was inferred from genetic approaches and transcriptome analysis in the Arabidopsis root tip. We used the developmental gradient at the maize leaf base as a model to study this transition, because it allows a direct comparison between endogenous hormone concentrations and the transitions between dividing, expanding, and mature tissue. Concentrations of auxin and cytokinins are highest in dividing tissues, whereas bioactive gibberellins (GAs) show a peak at the transition zone between the division and expansion zone. Combined metabolic and transcriptomic profiling revealed that this GA maximum is established by GA biosynthesis in the division zone (DZ) and active GA catabolism at the onset of the expansion zone. Mutants defective in GA synthesis and signaling, and transgenic plants overproducing GAs, demonstrate that altering GA levels specifically affects the size of the DZ, resulting in proportional changes in organ growth rates. This work thereby provides a novel molecular mechanism for the regulation of the transition from cell division to expansion that controls organ growth and size. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Biological bases of the maximum permissible exposure levels of the UK laser standard BS 4803: 1983

    International Nuclear Information System (INIS)

    McKinlay, A.F.; Harlen, F.

    1983-10-01

    The use of lasers has increased greatly over the past 15 years or so, to the extent that they are now used routinely in many occupational and public situations. There has been an increasing awareness of the potential hazards presented by lasers and substantial efforts have been made to formulate safety standards. In the UK the relevant Safety Standard is the British Standards Institution Standard BS 4803. This Standard was originally published in 1972 and a revision has recently been published (BS 4803: 1983). The revised standard has been developed using the American National Standards Institute Standard, ANSI Z136.1 (1973 onwards), as a model. In other countries, national standards have been similarly formulated, resulting in a large measure of international agreement through participation in the work of the International Electrotechnical Commission (IEC). The bases of laser safety standards are biophysical data on threshold injury effects, particularly on the retina, and the development of theoretical models of damage mechanisms. This report deals in some detail with the mechanisms of injury from over exposure to optical radiations, in particular with the dependency of the type and degree of damage on wavelength, image size and pulse duration. The maximum permissible exposure levels recommended in BS 4803: 1983 are compared with published data for damage thresholds and the adequacy of the standard is discussed. (author)

  2. Bayesian Maximum Entropy space/time estimation of surface water chloride in Maryland using river distances.

    Science.gov (United States)

    Jat, Prahlad; Serre, Marc L

    2016-12-01

    Widespread contamination of surface water chloride is an emerging environmental concern. Consequently accurate and cost-effective methods are needed to estimate chloride along all river miles of potentially contaminated watersheds. Here we introduce a Bayesian Maximum Entropy (BME) space/time geostatistical estimation framework that uses river distances, and we compare it with Euclidean BME to estimate surface water chloride from 2005 to 2014 in the Gunpowder-Patapsco, Severn, and Patuxent subbasins in Maryland. River BME improves the cross-validation R 2 by 23.67% over Euclidean BME, and river BME maps are significantly different than Euclidean BME maps, indicating that it is important to use river BME maps to assess water quality impairment. The river BME maps of chloride concentration show wide contamination throughout Baltimore and Columbia-Ellicott cities, the disappearance of a clean buffer separating these two large urban areas, and the emergence of multiple localized pockets of contamination in surrounding areas. The number of impaired river miles increased by 0.55% per year in 2005-2009 and by 1.23% per year in 2011-2014, corresponding to a marked acceleration of the rate of impairment. Our results support the need for control measures and increased monitoring of unassessed river miles. Copyright © 2016. Published by Elsevier Ltd.

  3. Should legislation regarding maximum Pb and Cd levels in human food also cover large game meat?

    Science.gov (United States)

    Taggart, Mark A; Reglero, Manuel M; Camarero, Pablo R; Mateo, Rafael

    2011-01-01

    Game meat may be contaminated with metals and metalloids if animals reside in anthropogenically polluted areas, or if ammunition used to kill the game contaminates the meat. Muscle tissue from red deer and wild boar shot in Ciudad Real province (Spain) in 2005-06 was analysed for As, Pb, Cu, Zn, Se and Cd. Samples were collected from hunting estates within and outside an area that has been historically used for mining, smelting and refining various metals and metalloids. Meat destined for human consumption, contained more Pb, As and Se (red deer) and Pb (boar) when harvested from animals that had resided in mined areas. Age related accumulation of Cd, Zn and As (in deer) and Cd, Cu and Se (in boar) was also observed. Two boar meat samples contained high Pb, at 352 and 2408 μg/g d.w., and these were likely to have been contaminated by Pb ammunition. Likewise, 19-84% of all samples (depending on species and sampling area) had Pb levels > 0.1 μg/g w.w., the EU maximum residue level (MRL) for farm reared meat. Between 9 and 43% of samples exceeded comparable Cd limits. Such data highlight a discrepancy between what is considered safe for human consumption in popular farmed meat (chicken, beef, lamb), and what in game may often exist. A risk assessment is presented which describes the number of meals required to exceed current tolerable weekly intakes (PTWIs) for Pb and Cd, and the potential contribution of large game consumption to such intake limit criteria. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. 40 CFR 130.7 - Total maximum daily loads (TMDL) and individual water quality-based effluent limitations.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Total maximum daily loads (TMDL) and individual water quality-based effluent limitations. 130.7 Section 130.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS WATER QUALITY PLANNING AND MANAGEMENT § 130.7 Total...

  5. Effect of glycine, DL-alanine and DL-2-aminobutyric acid on the temperature of maximum density of water

    International Nuclear Information System (INIS)

    Romero, Carmen M.; Torres, Andres Felipe

    2015-01-01

    Highlights: • Effect of α-amino acids on the temperature of maximum density of water is presented. • The addition of α-amino acids decreases the temperature of maximum density of water. • Despretz constants suggest that the amino acids behave as water structure breakers. • Despretz constants decrease as the number of CH 2 groups of the amino acid increase. • Solute disrupting effect becomes smaller as its hydrophobic character increases. - Abstract: The effect of glycine, DL-alanine and DL-2-aminobutyric acid on the temperature of maximum density of water was determined from density measurements using a magnetic float densimeter. Densities of aqueous solutions were measured within the temperature range from T = (275.65 to 278.65) K at intervals of T = 0.50 K over the concentration range between (0.0300 and 0.1000) mol · kg −1 . A linear relationship between density and concentration was obtained for all the systems in the temperature range considered. The temperature of maximum density was determined from the experimental results. The effect of the three amino acids is to decrease the temperature of maximum density of water and the decrease is proportional to molality according to Despretz equation. The effect of the amino acids on the temperature of maximum density decreases as the number of methylene groups of the alkyl chain becomes larger. The results are discussed in terms of (solute + water) interactions and the effect of amino acids on water structure

  6. Water level measurement uncertainty during BWR instability

    International Nuclear Information System (INIS)

    Torok, R.C.; Derbidge, T.C.; Healzer, J.M.

    1994-01-01

    This paper addresses the performance of the water-level measurement system in a boiling water reactor (BWR) during severe instability oscillations which, under some circumstances, can occur during an anticipated transient without SCRAM (ATWS). Test data from a prototypical mock-up of the water-level measurement system was used to refine and calibrate a water-level measurement system model. The model was then used to predict level measurement system response, using as boundary conditions vessel pressures calculated by ppercase RETRAN for an ATWS/instability event.The results of the study indicate that rapid pressure changes in the reactor pressure vessel which cause oscillations in downcomer water level, coupled with differences in instrument line lengths, can produce errors in the sensed water level. Using nominal parameters for the measurement system components, a severe instability transient which produced a 0.2 m peak-to-minimum water-level oscillation in the vessel downcomer was predicted to produce pressure difference equivalent to a 0.7 m level oscillation at the input to the differential pressure transmitter, 0.5 m oscillation at the output of the transmitter, and an oscillation of 0.3 m on the water-level indicator in the control room. The level measurement system error, caused by downcomer water-level oscillations and instrument line length differential, is mitigated by damping both in the differential pressure transmitter used to infer level and in the control room display instrument. ((orig.))

  7. Water: Local-Level Management

    International Development Research Centre (IDRC) Digital Library (Canada)

    Each publication distills IDRC's research experience with an eye to drawing out ..... in an arid area can drip as much water into the dry soil as might ever arrive ..... disintegrate without careful maintenance into smelly sources of disease and ...

  8. 40 CFR 142.65 - Variances and exemptions from the maximum contaminant levels for radionuclides.

    Science.gov (United States)

    2010-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER...-228 Ion exchange, reverse osmosis, lime softening. Uranium Ion exchange, reverse osmosis, lime... osmosis. Beta particle and photon radioactivity Ion exchange, reverse osmosis. (ii) In addition, the...

  9. Method of measuring reactor water level

    International Nuclear Information System (INIS)

    Shinohara, Kaoru.

    1979-01-01

    Purpose: To provide a water level measuring system so that a reactor water level detecting signal can be corrected in correspondence to a recirculation flow, thereby to carry out a correct water level detection in a wide range of the reactor. Method: According to the operation record of a precursor reactor, the ratio Δh of the lowering of the water level due to the recirculation flow is lowered in proportion to the ratiowith respect to the rated differential pressure of the recirculation flow. Accordingly, the flow of recirculation pump is measured by an elbow differential pressure generator utilizing an elbow of a pipe, and the measured value is multiplied by a gain by a ratio setter, and therefter, an addition computation is carried out by an adder for correcting the signal from a water level detector. When the signal from the water level detector is corrected in this manner, the influence of the lowering of the water level due to the recirculation flow can be removed, and an interlocker predetermined in the defined water level can be actuated, thus the influence of the dynamic pressure due to the recirculation flow acting on the instrumental pipe line detecting the reactor water level can be removed effectively. (Yoshino, Y.)

  10. Maximum Plant Uptakes for Water, Nutrients, and Oxygen Are Not Always Met by Irrigation Rate and Distribution in Water-based Cultivation Systems.

    Science.gov (United States)

    Blok, Chris; Jackson, Brian E; Guo, Xianfeng; de Visser, Pieter H B; Marcelis, Leo F M

    2017-01-01

    Growing on rooting media other than soils in situ -i.e., substrate-based growing- allows for higher yields than soil-based growing as transport rates of water, nutrients, and oxygen in substrate surpass those in soil. Possibly water-based growing allows for even higher yields as transport rates of water and nutrients in water surpass those in substrate, even though the transport of oxygen may be more complex. Transport rates can only limit growth when they are below a rate corresponding to maximum plant uptake. Our first objective was to compare Chrysanthemum growth performance for three water-based growing systems with different irrigation. We compared; multi-point irrigation into a pond (DeepFlow); one-point irrigation resulting in a thin film of running water (NutrientFlow) and multi-point irrigation as droplets through air (Aeroponic). Second objective was to compare press pots as propagation medium with nutrient solution as propagation medium. The comparison included DeepFlow water-rooted cuttings with either the stem 1 cm into the nutrient solution or with the stem 1 cm above the nutrient solution. Measurements included fresh weight, dry weight, length, water supply, nutrient supply, and oxygen levels. To account for differences in radiation sum received, crop performance was evaluated with Radiation Use Efficiency (RUE) expressed as dry weight over sum of Photosynthetically Active Radiation. The reference, DeepFlow with substrate-based propagation, showed the highest RUE, even while the oxygen supply provided by irrigation was potentially growth limiting. DeepFlow with water-based propagation showed 15-17% lower RUEs than the reference. NutrientFlow showed 8% lower RUE than the reference, in combination with potentially limiting irrigation supply of nutrients and oxygen. Aeroponic showed RUE levels similar to the reference and Aeroponic had non-limiting irrigation supply of water, nutrients, and oxygen. Water-based propagation affected the subsequent

  11. Maximum Permissible Risk Levels for Human Intake of Soil Contaminants: Fourth Series of Compounds

    NARCIS (Netherlands)

    Janssen PJCM; Apeldoorn ME van; Engelen JGM van; Schielen PCJI; Wouters MFA; CSR

    1998-01-01

    This report documents the human-toxicological risk assessment work done in 1996 and 1997 at RIVM's Centre for Substances and Risk Assessment within the scope of the RIVM project on soil intervention values for soil clean-up. The method used for derivation of the Maximum Permissible Risk, as

  12. 75 FR 26956 - Clean Water Act Section 303(d): Availability of Los Angeles Area Lakes Total Maximum Daily Loads...

    Science.gov (United States)

    2010-05-13

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9146-6] Clean Water Act Section 303(d): Availability of Los...: Notice of availability. SUMMARY: This action announces the availability of EPA proposed total maximum... nutrient, mercury, chlordane, dieldrin, DDT, PCB, and trash impairments pursuant to Clean Water Act Section...

  13. Method for steam generator water level measurement

    International Nuclear Information System (INIS)

    Srinivasan, J.S.

    1991-01-01

    This paper describes a nuclear power plant, a method of controlling the steam generator water level, wherein the steam generator has an upper level tap corresponding to an upper level, a lower level, a riser positioned between the lower and upper taps, and level sensor means for indicating water level between a first range limit and a second range limit, the sensor means being connected to at least the lower tap. It comprises: calculating a measure of velocity head at about the lower level tap; calculating a measure of full water level as the upper level less the measure of velocity head; calibrating the level sensor means to provide an output at the first limit corresponding to an input thereto representative of the measure of full level; calculating a high level setpoint equal to the level of the riser less a bias amount which is a function of the position of the riser relative to the span between the taps; and controlling the water level when the sensor means indicates that the high level setpoint has been reached

  14. Radon levels in a water distribution network

    International Nuclear Information System (INIS)

    Alabdula'aly, A.I.

    1997-01-01

    The capital city of Saudi Arabia, Riyadh, relies on both desalinated sea water as well as treated groundwater to meet all its water requirements. About 66% of the water demand is met by desalinated sea water, and the remaining is supplied by six groundwater treatment plants located in the vicinity of the city and supplied with water from 161 wells. The desalinated sea water is blended with only one plant product water and pumped to the distribution network, whereas the other five plants product water is pumped directly to the network. A study of 222 Rn levels in the city distribution network was carried out in which 89 samples were collected from different locations representing the city districts. All samples have shown low radon levels with an average concentration of 0.2 Bq l -1 and a range values of 0.1-1.0 Bq l -1 . The level of radon in different parts of the network was found to be influenced by the water sources to which they are supplied. The lowest radon levels were observed in districts supplied mostly by desalinated sea water. (Author)

  15. Maximum Evaporation Rates of Water Droplets Approaching Obstacles in the Atmosphere Under Icing Conditions

    Science.gov (United States)

    Lowell, H. H.

    1953-01-01

    When a closed body or a duct envelope moves through the atmosphere, air pressure and temperature rises occur ahead of the body or, under ram conditions, within the duct. If cloud water droplets are encountered, droplet evaporation will result because of the air-temperature rise and the relative velocity between the droplet and stagnating air. It is shown that the solution of the steady-state psychrometric equation provides evaporation rates which are the maximum possible when droplets are entrained in air moving along stagnation lines under such conditions. Calculations are made for a wide variety of water droplet diameters, ambient conditions, and flight Mach numbers. Droplet diameter, body size, and Mach number effects are found to predominate, whereas wide variation in ambient conditions are of relatively small significance in the determination of evaporation rates. The results are essentially exact for the case of movement of droplets having diameters smaller than about 30 microns along relatively long ducts (length at least several feet) or toward large obstacles (wings), since disequilibrium effects are then of little significance. Mass losses in the case of movement within ducts will often be significant fractions (one-fifth to one-half) of original droplet masses, while very small droplets within ducts will often disappear even though the entraining air is not fully stagnated. Wing-approach evaporation losses will usually be of the order of several percent of original droplet masses. Two numerical examples are given of the determination of local evaporation rates and total mass losses in cases involving cloud droplets approaching circular cylinders along stagnation lines. The cylinders chosen were of 3.95-inch (10.0+ cm) diameter and 39.5-inch 100+ cm) diameter. The smaller is representative of icing-rate measurement cylinders, while with the larger will be associated an air-flow field similar to that ahead of an airfoil having a leading-edge radius

  16. Forecasting Water Levels Using Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Shreenivas N. Londhe

    2011-06-01

    Full Text Available For all Ocean related activities it is necessary to predict the actual water levels as accurate as possible. The present work aims at predicting the water levels with a lead time of few hours to a day using the technique of artificial neural networks. Instead of using the previous and current values of observed water level time series directly as input and output the water level anomaly (difference between the observed water level and harmonically predicted tidal level is calculated for each hour and the ANN model is developed using this time series. The network predicted anomaly is then added to harmonic tidal level to predict the water levels. The exercise is carried out at six locations, two in The Gulf of Mexico, two in The Gulf of Maine and two in The Gulf of Alaska along the USA coastline. The ANN models performed reasonably well for all forecasting intervals at all the locations. The ANN models were also run in real time mode for a period of eight months. Considering the hurricane season in Gulf of Mexico the models were also tested particularly during hurricanes.

  17. 40 CFR Appendix I to Part 257 - Maximum Contaminant Levels (MCLs)

    Science.gov (United States)

    2010-07-01

    ... Drinking Water Act Chemical CAS No. MCL -(mg/l) Arsenic 7440-38-2 0.05 Barium 7440-39-3 1.0 Benzene 71-343... 0.004 Lead 7439-92-1 0.05 Mercury 7439-97-6 0.002 Methoxychlor 72-43-5 0.1 Nitrate 10.0 Selenium...

  18. Dependency of maximum goitrogenic response on some minimal level of thyroid hormone production

    International Nuclear Information System (INIS)

    March, B.E.; Poon, R.

    1981-01-01

    Thyroidal activity was studied in chicks given dietary thiouracil in conjunction with daily doses of thyroxine and with diets adequate and deficient in iodine. DL-thyroxine administered at doses up to 1.0 microgram per day for 10 to 12 days had no effect or slightly increased thyroid weight. Both the epithelial and colloid components of the thyroid gland were increased in response to thiouracil and to thiouracil in combination with low dosages of exogenous thyroxine. Radioiodine uptake was increased above the control with thiouracil and with thiouracil in conjunction with .5 and 1.0 microgram DL-thyroxine given daily. Birds receiving thiouracil, with and without exogenous thyroxine, showed a different pattern of radioiodine uptake and release than the control birds. Thiouracil-treated birds showed a rapid uptake of iodine following its administration, which was followed by a rapid decline immediately after peak accumulation, whereas in control birds thyroidal radioiodine concentration reached a plateau at the maximum concentration attained. The goitrogenic response to thiouracil was much greater when the diet was supplemented with iodine than when the diet was iodine-deficient. Thyroids under iodine deficiency contained greater percentages of epithelial tissue than with iodine-supplemented diets. Thyroid glands of chicks given thiouracil in an iodine-supplemented diet contained much more colloid than glands from iodine-deficient chicks with or without thiouracil. DL-thyroxine at a dosage of .5 microgram per day to chicks given thiouracil in an iodine-adequate diet increased, whereas higher dosages decreased thyroidal colloid. It is concluded that some minimal concentration of thyroid hormone is required for maximum goitrogenic response. It is not clear whether the response is entirely due to an effect on thyrotropin production or whether there is an effect of thyroid hormone on the thyroid gland itself

  19. Measurement of the temperature of density maximum of water solutions using a convective flow technique

    OpenAIRE

    Cawley, M.F.; McGlynn, D.; Mooney, P.A.

    2006-01-01

    A technique is described which yields an accurate measurement of the temperature of density maximum of fluids which exhibit such anomalous behaviour. The method relies on the detection of changes in convective flow in a rectangular cavity containing the test fluid.The normal single-cell convection which occurs in the presence of a horizontal temperature gradient changes to a double cell configuration in the vicinity of the density maximum, and this transition manifests itself in changes in th...

  20. 76 FR 549 - Clean Water Act Section 303(d): Notice for the Establishment of the Total Maximum Daily Load...

    Science.gov (United States)

    2011-01-05

    ... Establishment of the Total Maximum Daily Load (TMDL) for the Chesapeake Bay AGENCY: Environmental Protection... that when met will assure the attainment and maintenance of all applicable water quality standards for... productive estuaries in the world. Despite significant efforts by federal, state, and local governments and...

  1. Southern ocean warming, sea level and hydrological change during the Paleocene-Eocene thermal maximum

    Directory of Open Access Journals (Sweden)

    A. Sluijs

    2011-01-01

    Full Text Available A brief (~150 kyr period of widespread global average surface warming marks the transition between the Paleocene and Eocene epochs, ~56 million years ago. This so-called "Paleocene-Eocene thermal maximum" (PETM is associated with the massive injection of 13C-depleted carbon, reflected in a negative carbon isotope excursion (CIE. Biotic responses include a global abundance peak (acme of the subtropical dinoflagellate Apectodinium. Here we identify the PETM in a marine sedimentary sequence deposited on the East Tasman Plateau at Ocean Drilling Program (ODP Site 1172 and show, based on the organic paleothermometer TEX86, that southwest Pacific sea surface temperatures increased from ~26 °C to ~33°C during the PETM. Such temperatures before, during and after the PETM are >10 °C warmer than predicted by paleoclimate model simulations for this latitude. In part, this discrepancy may be explained by potential seasonal biases in the TEX86 proxy in polar oceans. Additionally, the data suggest that not only Arctic, but also Antarctic temperatures may be underestimated in simulations of ancient greenhouse climates by current generation fully coupled climate models. An early influx of abundant Apectodinium confirms that environmental change preceded the CIE on a global scale. Organic dinoflagellate cyst assemblages suggest a local decrease in the amount of river run off reaching the core site during the PETM, possibly in concert with eustatic rise. Moreover, the assemblages suggest changes in seasonality of the regional hydrological system and storm activity. Finally, significant variation in dinoflagellate cyst assemblages during the PETM indicates that southwest Pacific climates varied significantly over time scales of 103 – 104 years during this event, a finding comparable to similar studies of PETM successions from the New Jersey Shelf.

  2. 77 FR 20059 - License Amendment To Increase the Maximum Reactor Power Level, Florida Power & Light Company...

    Science.gov (United States)

    2012-04-03

    ... reduce and mitigate salinity levels in groundwater; operational changes to the PTN cooling canal system... approving the proposed expansion of PTN Units 3 and 4 based on compliance with conditions required by the... restrooms would be used during plant modifications. Therefore, land use conditions would not change at the...

  3. Water-level fluctuations influence sediment porewater ...

    Science.gov (United States)

    Reservoirs typically have elevated fish mercury (Hg) levels compared to natural lakes and rivers. A unique feature of reservoirs is water-level management which can result in sediment exposure to the air. The objective of this study is to identify how reservoir water-level fluctuations impact Hg cycling, particularly the formation of the more toxic and bioaccumulative methylmercury (MeHg). Total-Hg (THg), MeHg, stable isotope methylation rates and several ancillary parameters were measured in reservoir sediments (including some in porewater and overlying water) that are seasonally and permanently inundated. The results showed that sediment and porewater MeHg concentrations were over 3-times higher in areas experiencing water-level fluctuations compared to permanently inundated sediments. Analysis of the data suggest that the enhanced breakdown of organic matter in sediments experiencing water-level fluctuations has a two-fold effect on stimulating Hg methylation: 1) it increases the partitioning of inorganic Hg from the solid phase into the porewater phase (lower log Kd values) where it is more bioavailable for methylation; and 2) it increases dissolved organic carbon (DOC) in the porewater which can stimulate the microbial community that can methylate Hg. Sulfate concentrations and cycling were enhanced in the seasonally inundated sediments and may have also contributed to increased MeHg production. Overall, our results suggest that reservoir management a

  4. Climatic impacts of fresh water hosing under Last Glacial Maximum conditions: a multi-model study

    NARCIS (Netherlands)

    Kageyama, M.; Merkel, U.; Otto-Bliesner, B.; Prange, M.; Abe-Ouchi, A.; Lohmann, G.; Ohgaito, R.; Roche, D.M.V.A.P.; Singarayer, J

    2013-01-01

    Fresh water hosing simulations, in which a fresh water flux is imposed in the North Atlantic to force fluctuations of the Atlantic Meridional Overturning Circulation, have been routinely performed, first to study the climatic signature of different states of this circulation, then, under present or

  5. Multi-level restricted maximum likelihood covariance estimation and kriging for large non-gridded spatial datasets

    KAUST Repository

    Castrillon, Julio

    2015-11-10

    We develop a multi-level restricted Gaussian maximum likelihood method for estimating the covariance function parameters and computing the best unbiased predictor. Our approach produces a new set of multi-level contrasts where the deterministic parameters of the model are filtered out thus enabling the estimation of the covariance parameters to be decoupled from the deterministic component. Moreover, the multi-level covariance matrix of the contrasts exhibit fast decay that is dependent on the smoothness of the covariance function. Due to the fast decay of the multi-level covariance matrix coefficients only a small set is computed with a level dependent criterion. We demonstrate our approach on problems of up to 512,000 observations with a Matérn covariance function and highly irregular placements of the observations. In addition, these problems are numerically unstable and hard to solve with traditional methods.

  6. Stability numerical analysis of soil cave in karst area to drawdown of underground water level

    Science.gov (United States)

    Mo, Yizheng; Xiao, Rencheng; Deng, Zongwei

    2018-05-01

    With the underground water level falling, the reliable estimates of the stability and deformation characteristics of soil caves in karst region area are required for analysis used for engineering design. Aimed at this goal, combined with practical engineering and field geotechnical test, detail analysis on vertical maximum displacement of top, vertical maximum displacement of surface, maximum principal stress and maximum shear stress were conducted by finite element software, with an emphasis on two varying factors: the size and the depth of soil cave. The calculations on the soil cave show that, its stability of soil cave is affected by both the size and depth, and only when extending a certain limit, the collapse occurred along with the falling of underground water; Additionally, its maximum shear stress is in arch toes, and its deformation curve trend of maximum displacement is similar to the maximum shear stress, which further verified that the collapse of soil cave was mainly due to shear-failure.

  7. County-Level Climate Uncertainty for Risk Assessments: Volume 4 Appendix C - Historical Maximum Near-Surface Air Temperature.

    Energy Technology Data Exchange (ETDEWEB)

    Backus, George A.; Lowry, Thomas Stephen; Jones, Shannon M; Walker, La Tonya Nicole; Roberts, Barry L; Malczynski, Leonard A.

    2017-06-01

    This report uses the CMIP5 series of climate model simulations to produce country- level uncertainty distributions for use in socioeconomic risk assessments of climate change impacts. It provides appropriate probability distributions, by month, for 169 countries and autonomous-areas on temperature, precipitation, maximum temperature, maximum wind speed, humidity, runoff, soil moisture and evaporation for the historical period (1976-2005), and for decadal time periods to 2100. It also provides historical and future distributions for the Arctic region on ice concentration, ice thickness, age of ice, and ice ridging in 15-degree longitude arc segments from the Arctic Circle to 80 degrees latitude, plus two polar semicircular regions from 80 to 90 degrees latitude. The uncertainty is meant to describe the lack of knowledge rather than imprecision in the physical simulation because the emphasis is on unfalsified risk and its use to determine potential socioeconomic impacts. The full report is contained in 27 volumes.

  8. County-Level Climate Uncertainty for Risk Assessments: Volume 18 Appendix Q - Historical Maximum Near-Surface Wind Speed.

    Energy Technology Data Exchange (ETDEWEB)

    Backus, George A.; Lowry, Thomas Stephen; Jones, Shannon M; Walker, La Tonya Nicole; Roberts, Barry L; Malczynski, Leonard A.

    2017-06-01

    This report uses the CMIP5 series of climate model simulations to produce country- level uncertainty distributions for use in socioeconomic risk assessments of climate change impacts. It provides appropriate probability distributions, by month, for 169 countries and autonomous-areas on temperature, precipitation, maximum temperature, maximum wind speed, humidity, runoff, soil moisture and evaporation for the historical period (1976-2005), and for decadal time periods to 2100. It also provides historical and future distributions for the Arctic region on ice concentration, ice thickness, age of ice, and ice ridging in 15-degree longitude arc segments from the Arctic Circle to 80 degrees latitude, plus two polar semicircular regions from 80 to 90 degrees latitude. The uncertainty is meant to describe the lack of knowledge rather than imprecision in the physical simulation because the emphasis is on unfalsified risk and its use to determine potential socioeconom ic impacts. The full report is contained in 27 volumes.

  9. Analog Fixed Maximum Power Point Control for a PWM Step-downConverter for Water Pumping Installations

    DEFF Research Database (Denmark)

    Beltran, H.; Perez, E.; Chen, Zhe

    2009-01-01

    This paper describes a Fixed Maximum Power Point analog control used in a step-down Pulse Width Modulated power converter. The DC/DC converter drives a DC motor used in small water pumping installations, without any electric storage device. The power supply is provided by PV panels working around....... The proposed Optimal Power Point fix voltage control system is analyzed in comparison to other complex controls....... their maximum power point, with a fixed operating voltage value. The control circuit implementation is not only simple and cheap, but also robust and reliable. System protections and adjustments are also proposed. Simulations and hardware are reported in the paper for a 150W water pumping application system...

  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. An investigation of the maximum penetration level of a photovoltaic (PV) system into a traditional distribution grid

    Science.gov (United States)

    Chalise, Santosh

    Although solar photovoltaic (PV) systems have remained the fastest growing renewable power generating technology, variability as well as uncertainty in the output of PV plants is a significant issue. This rapid increase in PV grid-connected generation presents not only progress in clean energy but also challenges in integration with traditional electric power grids which were designed for transmission and distribution of power from central stations. Unlike conventional electric generators, PV panels do not have rotating parts and thus have no inertia. This potentially causes a problem when the solar irradiance incident upon a PV plant changes suddenly, for example, when scattered clouds pass quickly overhead. The output power of the PV plant may fluctuate nearly as rapidly as the incident irradiance. These rapid power output fluctuations may then cause voltage fluctuations, frequency fluctuations, and power quality issues. These power quality issues are more severe with increasing PV plant power output. This limits the maximum power output allowed from interconnected PV plants. Voltage regulation of a distribution system, a focus of this research, is a prime limiting factor in PV penetration levels. The IEEE 13-node test feeder, modeled and tested in the MATLAB/Simulink environment, was used as an example distribution feeder to analyze the maximum acceptable penetration of a PV plant. The effect of the PV plant's location was investigated, along with the addition of a VAR compensating device (a D-STATCOM in this case). The results were used to develop simple guidelines for determining an initial estimate of the maximum PV penetration level on a distribution feeder. For example, when no compensating devices are added to the system, a higher level of PV penetration is generally achieved by installing the PV plant close to the substation. The opposite is true when a VAR compensator is installed with the PV plant. In these cases, PV penetration levels over 50% may be

  12. Fluctuations of Lake Orta water levels: preliminary analyses

    Directory of Open Access Journals (Sweden)

    Helmi Saidi

    2016-04-01

    Full Text Available While the effects of past industrial pollution on the chemistry and biology of Lake Orta have been well documented, annual and seasonal fluctuations of lake levels have not yet been studied. Considering their potential impacts on both the ecosystem and on human safety, fluctuations in lake levels are an important aspect of limnological research. In the enormous catchment of Lake Maggiore, there are many rivers and lakes, and the amount of annual precipitation is both high and concentrated in spring and autumn. This has produced major flood events, most recently in November 2014. Flood events are also frequent on Lake Orta, occurring roughly triennially since 1917. The 1926, 1951, 1976 and 2014 floods were severe, with lake levels raised from 2.30 m to 3.46 m above the hydrometric zero. The most important event occurred in 1976, with a maximum level equal to 292.31 m asl and a return period of 147 years. In 2014 the lake level reached 291.89 m asl and its return period was 54 years. In this study, we defined trends and temporal fluctuations in Lake Orta water levels from 1917 to 2014, focusing on extremes. We report both annual maximum and seasonal variations of the lake water levels over this period. Both Mann-Kendall trend tests and simple linear regression were utilized to detect monotonic trends in annual and seasonal extremes, and logistic regression was used to detect trends in the number of flood events. Lake level decreased during winter and summer seasons, and a small but statistically non-significant positive trend was found in the number of flood events over the period. We provide estimations of return period for lake levels, a metric which could be used in planning lake flood protection measures.

  13. Estimating Water Demand in Urban Indonesia: A Maximum Likelihood Approach to block Rate Pricing Data

    NARCIS (Netherlands)

    Rietveld, Piet; Rouwendal, Jan; Zwart, Bert

    1997-01-01

    In this paper the Burtless and Hausman model is used to estimate water demand in Salatiga, Indonesia. Other statistical models, as OLS and IV, are found to be inappropiate. A topic, which does not seem to appear in previous studies, is the fact that the density function of the loglikelihood can be

  14. Influence of maximum water temperature on occurrence of Lahontan cutthroat trout within streams

    Science.gov (United States)

    J. Dunham; R. Schroeter; B. Rieman

    2003-01-01

    We measured water temperature at 87 sites in six streams in two different years (1998 and 1999) to test for association with the occurrence of Lahontan cutthroat trout Oncorhynchus clarki henshawi. Because laboratory studies suggest that Lahontan cutthroat trout begin to show signs of acute stress at warm (>22°C) temperatures, we focused on the...

  15. A improved tidal method without water level

    Science.gov (United States)

    Luo, xiaowen

    2017-04-01

    Now most tide are obtained use water Level and pressure type water gage, but it is difficult to install them and reading is in low accuracy in this method . In view of above-mentioned facts, In order to improve tide accuracy, A improved method is introduced.sea level is obtained in given time using high-precision GNSS buoy combined instantaneous position from pressure gage. two steps are as following, (1) the GNSS time service is used as the source of synchronization reference in tidal measurement; (2) centimeter-level sea surface positions are obtained in real time using difference GNSS The improved method used in seafloor topography survey,in 145 cross points, 95% meet the requirements of the Hydrographic survey specification. It is effective method to obtain higher accuracy tide.

  16. Climate-driven changes in water level

    DEFF Research Database (Denmark)

    Hansen, Rikke Bjerring; Olsen, Jesper; Jeppesen, Erik

    2013-01-01

    level rose. Moreover, Nymphaeaceae trichosclereids were abundant during the period of algal enrichment. Cladoceran taxa associated with floating leaved plants or benthic habitats responded in a complex way to changes in water level, but the cladoceran assemblages generally reflected deep lake conditions...... 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 8350-8260 before an abrupt increase during 8260-8210. This pattern shows that the climate anomaly started...... rates of cladoceran subfossils and algal pigments, possibly due to increased turbidity and reduced nutrient input during this drier period. Pigment analysis also showed added importance of diatoms and cryptophytes during this climate anomaly, while cyanobacteria became more important when the water...

  17. The maximum ground level concentration of air pollutant and the effect of plume rise on concentration estimates

    International Nuclear Information System (INIS)

    Mayhoub, A.B.; Azzam, A.

    1991-01-01

    The emission of an air pollutant from an elevated point source according to Gaussian plume model has been presented. An elementary theoretical treatment for both the highest possible ground-level concentration and the downwind distance at which this maximum occurs for different stability classes has been constructed. The effective height release modification was taken into consideration. An illustrative case study, namely, the emission from the research reactor in Inchas, has been studied. The results of these analytical treatments and of the derived semi-empirical formulae are discussed and presented in few illustrative diagrams

  18. Maximum coherent superposition state achievement using a non-resonant pulse train in non-degenerate three-level atoms

    International Nuclear Information System (INIS)

    Deng, Li; Niu, Yueping; Jin, Luling; Gong, Shangqing

    2010-01-01

    The coherent superposition state of the lower two levels in non-degenerate three-level Λ atoms is investigated using the accumulative effects of non-resonant pulse trains when the repetition period is smaller than the decay time of the upper level. First, using a rectangular pulse train, the accumulative effects are re-examined in the non-resonant two-level atoms and the modified constructive accumulation equation is analytically given. The equation shows that the relative phase and the repetition period are important in the accumulative effect. Next, under the modified equation in the non-degenerate three-level Λ atoms, we show that besides the constructive accumulation effect, the use of the partial constructive accumulation effect can also achieve the steady state of the maximum coherent superposition state of the lower two levels and the latter condition is relatively easier to manipulate. The analysis is verified by numerical calculations. The influence of the external levels in such a case is also considered and we find that it can be avoided effectively. The above analysis is also applicable to pulse trains with arbitrary envelopes.

  19. Climatic impacts of fresh water hosing under Last Glacial Maximum conditions: a multi-model study

    Directory of Open Access Journals (Sweden)

    M. Kageyama

    2013-04-01

    Full Text Available Fresh water hosing simulations, in which a fresh water flux is imposed in the North Atlantic to force fluctuations of the Atlantic Meridional Overturning Circulation, have been routinely performed, first to study the climatic signature of different states of this circulation, then, under present or future conditions, to investigate the potential impact of a partial melting of the Greenland ice sheet. The most compelling examples of climatic changes potentially related to AMOC abrupt variations, however, are found in high resolution palaeo-records from around the globe for the last glacial period. To study those more specifically, more and more fresh water hosing experiments have been performed under glacial conditions in the recent years. Here we compare an ensemble constituted by 11 such simulations run with 6 different climate models. All simulations follow a slightly different design, but are sufficiently close in their design to be compared. They all study the impact of a fresh water hosing imposed in the extra-tropical North Atlantic. Common features in the model responses to hosing are the cooling over the North Atlantic, extending along the sub-tropical gyre in the tropical North Atlantic, the southward shift of the Atlantic ITCZ and the weakening of the African and Indian monsoons. On the other hand, the expression of the bipolar see-saw, i.e., warming in the Southern Hemisphere, differs from model to model, with some restricting it to the South Atlantic and specific regions of the southern ocean while others simulate a widespread southern ocean warming. The relationships between the features common to most models, i.e., climate changes over the north and tropical Atlantic, African and Asian monsoon regions, are further quantified. These suggest a tight correlation between the temperature and precipitation changes over the extra-tropical North Atlantic, but different pathways for the teleconnections between the AMOC/North Atlantic region

  20. The maximum and minimum values of the heat Q transmitted from metal to boiling water under atmospheric pressure

    International Nuclear Information System (INIS)

    Nukiyama, S.

    1991-01-01

    The quantity of heat transmitted from a metal surface to boiling water increases as the temperature difference ΔT is increased, but after the ΔT has reached a certain limit, quantity Q decreases with further increase in ΔT. This turning point is the maximum value of heat transmitted. The existence of this point was actually observed in the experiment. Under atmospheric pressure, ΔT corresponding to the maximum value of heat transfer for water at 100 degrees C falls between 20-40 degrees C, and Q is between 1,080,000 and 1,800,000 kcal/m 2 h (i.e. between 2,000 and 3,000 kg/m 2 h, if expressed in constant evaporation rate at 100 degrees C); this figure is larger than the maximum value of heat transfer as was previously considered. In this paper the minimum value of heat transfer was obtained, and in the Q-ΔT curve for the high temperature region, the burn-out effect is discussed

  1. Determination of maximum water temperature within the spent fuel pool of Angra Nuclear Power Plant - Unit 3

    Energy Technology Data Exchange (ETDEWEB)

    Werner, F.L., E-mail: fernanda.werner@poli.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Departamento de Engenharia Nuclear; Alves, A.S.M., E-mail: asergi@eletronuclear.gov.br [Eletrobras Termonuclear (Eletronuclear), Rio de Janeiro, RJ (Brazil); Frutuoso e Melo, P.F., E-mail: frutuoso@nuclear.ufrj.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    In this paper, a mathematical model for the determination of the maximum water temperature within the spent fuel pool of Angra Nuclear Power Plant – Unit 3 was developed. The model was obtained from the boundary layer analysis and the application of Navier-Stokes equation to a vertical flat plate immersed in a water flow under free convection regime. Both types of pressure loss coefficients through the flow channel were considers in the modeling, the form coefficient for fuel assemblies (FAs) and the loss due to rod friction. The resulting equations enabled the determination of a mixed water temperature below the storage racks (High Density Storage Racks) as well as the estimation of a temperature gradient through the racks. The model was applied to the authorized operation of the plant (power operation, plant outage and upset condition) and faulted conditions (loss of coolant accidents and external events). The results obtained are in agreement with Brazilian and international standards. (author)

  2. Determination of maximum water temperature within the spent fuel pool of Angra Nuclear Power Plant - Unit 3

    International Nuclear Information System (INIS)

    Werner, F.L.; Frutuoso e Melo, P.F.

    2017-01-01

    In this paper, a mathematical model for the determination of the maximum water temperature within the spent fuel pool of Angra Nuclear Power Plant – Unit 3 was developed. The model was obtained from the boundary layer analysis and the application of Navier-Stokes equation to a vertical flat plate immersed in a water flow under free convection regime. Both types of pressure loss coefficients through the flow channel were considers in the modeling, the form coefficient for fuel assemblies (FAs) and the loss due to rod friction. The resulting equations enabled the determination of a mixed water temperature below the storage racks (High Density Storage Racks) as well as the estimation of a temperature gradient through the racks. The model was applied to the authorized operation of the plant (power operation, plant outage and upset condition) and faulted conditions (loss of coolant accidents and external events). The results obtained are in agreement with Brazilian and international standards. (author)

  3. Self-reported sleep disturbances due to railway noise: exposure-response relationships for nighttime equivalent and maximum noise levels.

    Science.gov (United States)

    Aasvang, Gunn Marit; Moum, Torbjorn; Engdahl, Bo

    2008-07-01

    The objective of the present survey was to study self-reported sleep disturbances due to railway noise with respect to nighttime equivalent noise level (L(p,A,eq,night)) and maximum noise level (L(p,A,max)). A sample of 1349 people in and around Oslo in Norway exposed to railway noise was studied in a cross-sectional survey to obtain data on sleep disturbances, sleep problems due to noise, and personal characteristics including noise sensitivity. Individual noise exposure levels were determined outside of the bedroom facade, the most-exposed facade, and inside the respondents' bedrooms. The exposure-response relationships were analyzed by using logistic regression models, controlling for possible modifying factors including the number of noise events (train pass-by frequency). L(p,A,eq,night) and L(p,A,max) were significantly correlated, and the proportion of reported noise-induced sleep problems increased as both L(p,A,eq,night) and L(p,A,max) increased. Noise sensitivity, type of bedroom window, and pass-by frequency were significant factors affecting noise-induced sleep disturbances, in addition to the noise exposure level. Because about half of the study population did not use a bedroom at the most-exposed side of the house, the exposure-response curve obtained by using noise levels for the most-exposed facade underestimated noise-induced sleep disturbance for those who actually have their bedroom at the most-exposed facade.

  4. GNSS-Reflectometry based water level monitoring

    Science.gov (United States)

    Beckheinrich, Jamila; Schön, Steffen; Beyerle, Georg; Apel, Heiko; Semmling, Maximilian; Wickert, Jens

    2013-04-01

    Due to climate changing conditions severe changes in the Mekong delta in Vietnam have been recorded in the last years. The goal of the German Vietnamese WISDOM (Water-related Information system for the Sustainable Development Of the Mekong Delta) project is to build an information system to support and assist the decision makers, planners and authorities for an optimized water and land management. One of WISDOM's tasks is the flood monitoring of the Mekong delta. Earth reflected L-band signals from the Global Navigation Satellite System show a high reflectivity on water and ice surfaces or on wet soil so that GNSS-Reflectometry (GNSS-R) could contribute to monitor the water level in the main streams of the Mekong delta complementary to already existing monitoring networks. In principle, two different GNSS-R methods exist: the code- and the phase-based one. As the latter being more accurate, a new generation of GORS (GNSS Occultation, Reflectometry and Scatterometry) JAVAD DELTA GNSS receiver has been developed with the aim to extract precise phase observations. In a two week lasting measurement campaign, the receiver has been tested and several reflection events at the 150-200 m wide Can Tho river in Vietnam have been recorded. To analyze the geometrical impact on the quantity and quality of the reflection traces two different antennas height were tested. To track separately the direct and the reflected signal, two antennas were used. To derive an average height of the water level, for a 15 min observation interval, a phase model has been developed. Combined with the coherent observations, the minimum slope has been calculated based on the Least- Squares method. As cycle slips and outliers will impair the results, a preprocessing of the data has been performed. A cycle slip detection strategy that allows for automatic detection, identification and correction is proposed. To identify outliers, the data snooping method developed by Baarda 1968 is used. In this

  5. Development of total maximum daily loads for bacteria impaired watershed using the comprehensive hydrology and water quality simulation model.

    Science.gov (United States)

    Kim, Sang M; Brannan, Kevin M; Zeckoski, Rebecca W; Benham, Brian L

    2014-01-01

    The objective of this study was to develop bacteria total maximum daily loads (TMDLs) for the Hardware River watershed in the Commonwealth of Virginia, USA. The TMDL program is an integrated watershed management approach required by the Clean Water Act. The TMDLs were developed to meet Virginia's water quality standard for bacteria at the time, which stated that the calendar-month geometric mean concentration of Escherichia coli should not exceed 126 cfu/100 mL, and that no single sample should exceed a concentration of 235 cfu/100 mL. The bacteria impairment TMDLs were developed using the Hydrological Simulation Program-FORTRAN (HSPF). The hydrology and water quality components of HSPF were calibrated and validated using data from the Hardware River watershed to ensure that the model adequately simulated runoff and bacteria concentrations. The calibrated and validated HSPF model was used to estimate the contributions from the various bacteria sources in the Hardware River watershed to the in-stream concentration. Bacteria loads were estimated through an extensive source characterization process. Simulation results for existing conditions indicated that the majority of the bacteria came from livestock and wildlife direct deposits and pervious lands. Different source reduction scenarios were evaluated to identify scenarios that meet both the geometric mean and single sample maximum E. coli criteria with zero violations. The resulting scenarios required extreme and impractical reductions from livestock and wildlife sources. Results from studies similar to this across Virginia partially contributed to a reconsideration of the standard's applicability to TMDL development.

  6. Further European initiatives and regulations concerning radiation protection: drinking water guideline, maximum permissible contamination in food products and feeding stuff

    International Nuclear Information System (INIS)

    Mundigl, Stefan

    2013-01-01

    The radiation protection community has observed intensively the development of basic safety standards concerning protection against hazards of ionizing radiation. The new core part of the European radiation protection legislation is complemented by several specialized regulations relevant for radiation protection. Besides the existing regulations in the field of emergency protection the European Commission initiated a drinking water guideline that will be published in the near future. Furthermore the European commission approved a revised regulation concerning the maximum permissible contamination limits for food products and feeding stuff in case of a future nuclear accident. Together with the new radiation protection basic standards a new complete, coherent and modernized European regulation package will be accomplished.

  7. Similar mid-depth Atlantic water mass provenance during the Last Glacial Maximum and Heinrich Stadial 1

    Science.gov (United States)

    Howe, Jacob N. W.; Huang, Kuo-Fang; Oppo, Delia W.; Chiessi, Cristiano M.; Mulitza, Stefan; Blusztajn, Jurek; Piotrowski, Alexander M.

    2018-05-01

    The delivery of freshwater to the North Atlantic during Heinrich Stadial 1 (HS1) is thought to have fundamentally altered the operation of Atlantic meridional overturning circulation (AMOC). Although benthic foraminiferal carbon isotope records from the mid-depth Atlantic show a pronounced excursion to lower values during HS1, whether these shifts correspond to changes in water mass proportions, advection, or shifts in the carbon cycle remains unclear. Here we present new deglacial records of authigenic neodymium isotopes - a water mass tracer that is independent of the carbon cycle - from two cores in the mid-depth South Atlantic. We find no change in neodymium isotopic composition, and thus water mass proportions, between the Last Glacial Maximum (LGM) and HS1, despite large decreases in carbon isotope values at the onset of HS1 in the same cores. We suggest that the excursions of carbon isotopes to lower values were likely caused by the accumulation of respired organic matter due to slow overturning circulation, rather than to increased southern-sourced water, as typically assumed. The finding that there was little change in water mass provenance in the mid-depth South Atlantic between the LGM and HS1, despite decreased overturning, suggests that the rate of production of mid-depth southern-sourced water mass decreased in concert with decreased production of northern-sourced intermediate water at the onset of HS1. Consequently, we propose that even drastic changes in the strength of AMOC need not cause a significant change in South Atlantic mid-depth water mass proportions.

  8. Relative sea-level changes and crustal movements in Britain and Ireland since the Last Glacial Maximum

    Science.gov (United States)

    Shennan, Ian; Bradley, Sarah L.; Edwards, Robin

    2018-05-01

    The new sea-level database for Britain and Ireland contains >2100 data points from 86 regions and records relative sea-level (RSL) changes over the last 20 ka and across elevations ranging from ∼+40 to -55 m. It reveals radically different patterns of RSL as we move from regions near the centre of the Celtic ice sheet at the last glacial maximum to regions near and beyond the ice limits. Validated sea-level index points and limiting data show good agreement with the broad patterns of RSL change predicted by current glacial isostatic adjustment (GIA) models. The index points show no consistent pattern of synchronous coastal advance and retreat across different regions, ∼100-500 km scale, indicating that within-estuary processes, rather than decimetre- and centennial-scale oscillations in sea level, produce major controls on the temporal pattern of horizontal shifts in coastal sedimentary environments. Comparisons between the database and GIA model predictions for multiple regions provide potentially powerful constraints on various characteristics of global GIA models, including the magnitude of MWP1A, the final deglaciation of the Laurentide ice sheet and the continued melting of Antarctica after 7 ka BP.

  9. 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 μm 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 μm resolution) will be installed in the mine workings in the near future, some

  10. Water levels shape fishing participation in flood-control reservoirs

    Science.gov (United States)

    Miranda, Leandro E.; Meals, K. O.

    2013-01-01

    We examined the relationship between fishing effort (hours fished) and average March–May water level in 3 flood control reservoirs in Mississippi. Fishing effort increased as water level rose, peaked at intermediate water levels, and decreased at high water levels. We suggest that the observed arched-shaped relationship is driven by the shifting influence of fishability (adequacy of the fishing circumstances from an angler's perspective) and catch rate along a water level continuum. Fishability reduces fishing effort during low water, despite the potential for higher catch rates. Conversely, reduced catch rates and fishability at high water also curtail effort. Thus, both high and low water levels seem to discourage fishing effort, whereas anglers seem to favor intermediate water levels. Our results have implications for water level management in reservoirs with large water level fluctuations.

  11. Mercury and water level fluctuations in lakes of northern Minnesota

    Science.gov (United States)

    Larson, James H.; Maki, Ryan P; Christensen, Victoria G.; Sandheinrich, Mark B.; LeDuc, Jaime F.; Kissane, Claire; Knights, Brent C.

    2017-01-01

    Large lake ecosystems support a variety of ecosystem services in surrounding communities, including recreational and commercial fishing. However, many northern temperate fisheries are contaminated by mercury. Annual variation in mercury accumulation in fish has previously been linked to water level (WL) fluctuations, opening the possibility of regulating water levels in a manner that minimizes or reduces mercury contamination in fisheries. Here, we compiled a long-term dataset (1997-2015) of mercury content in young-of-year Yellow Perch (Perca flavescens) from six lakes on the border between the U.S. and Canada and examined whether mercury content appeared to be related to several metrics of WL fluctuation (e.g., spring WL rise, annual maximum WL, and year-to-year change in maximum WL). Using simple correlation analysis, several WL metrics appear to be strongly correlated to Yellow Perch mercury content, although the strength of these correlations varies by lake. We also used many WL metrics, water quality measurements, temperature and annual deposition data to build predictive models using partial least squared regression (PLSR) analysis for each lake. These PLSR models showed some variation among lakes, but also supported strong associations between WL fluctuations and annual variation in Yellow Perch mercury content. The study lakes underwent a modest change in WL management in 2000, when winter WL minimums were increased by about 1 m in five of the six study lakes. Using the PLSR models, we estimated how this change in WL management would have affected Yellow Perch mercury content. For four of the study lakes, the change in WL management that occurred in 2000 likely reduced Yellow Perch mercury content, relative to the previous WL management regime.

  12. Circulation of the thermocline salinity maximum waters off the Northern Brazil as inferred from in situ measurements and numerical results

    Energy Technology Data Exchange (ETDEWEB)

    Silva, A.C. [Universidade Federal do Ceara, Fortaleza, CE (Brazil). Inst. de Ciencias do Mar; Bourles, B. [Inst. de Recherche pour le Developpement, Cotonou (Benin); Araujo, M. [UFPE, Recife, PE (Brazil). Lab. de Oceanografia Fisica Estuarina e Costeira

    2009-07-01

    High resolution hydrographic observations of temperature and salinity are used to analyse the subsurface circulation along the coast of North Brazil, off the Amazon mouth, between 2 S and 6 N. Observations are presented from four cruises carried out in different periods of the year (March-May 1995, May-June 1999, July-August 2001 and October-November 1997). Numerical model outputs complement the results of the shipboard measurements, and are used to complete the descriptions of mesoscale circulation. The Salinity Maximum Waters are here analyzed, principally in order to describe the penetration of waters originating in the Southern Hemisphere toward the Northern Hemisphere through the North Brazil Current (NBC)/North Brazil Undercurrent (NBUC). Our results show that, if the Equatorial Undercurrent (EUC) is fed by Northern Atlantic Waters, this contribution may only occur in the ocean interior, east of the western boundary around 100 m depth. Modeling results indicate a southward penetration of the Western Boundary Undercurrent (WBUC) below the thermocline, along the North Brazilian coast into the EUC or the North Equatorial Undercurrent (NEUC) (around 48 W-3 N). The WBUC in the region does not flow more south than 3 N. The northern waters are diverted eastward either by the NBC retroflection or by the northern edge of the associated clockwise rings. The existence of subsurface mesoscale rings associated to the NBC retroflection is evidenced, without any signature in the surface layer, so confirming earlier numerical model outputs. These subsurface anticyclones, linked to the NBC/NBUC retroflection into the North Equatorial Undercurrent and the EUC, contribute to the transport of South Atlantic high salinity water into the Northern Hemisphere. (orig.)

  13. Total Water Level Fun Facts: The Relative Contribution of Extreme Total Water Levels Along the US West Coast

    Science.gov (United States)

    Serafin, K.; Ruggiero, P.; Stockdon, H. F.

    2016-02-01

    In the fall of 2014, parts of the US West Coast endured some of the highest monthly mean sea level anomalies on record, likely due to the presence of "the blob" (Bond et al., 2015), an anomalously warm water mass in the NE Pacific. However, despite the significantly above average water levels, the coastline experienced only marginal coastal flooding and erosion hazards because the ensuing winter lacked significant storms, underscoring the fact that extreme total water levels (TWLs) are compound events. To better understand how several individual processes combine to cause devastating coastal hazards, we investigate the relative contribution that each component (waves, tides, and non-tidal residuals) has on extreme TWLs on sandy beaches. Water level records along the US West Coast are decomposed into mean sea level, astronomical tide, and non-tidal residuals (NTRs). The NTR is further split into an intra-annual seasonal signal, monthly mean sea level anomalies (inter-annual variability), and meteorological surge. TWL time series are then generated by combining water levels with wave runup, computed using wave data and beach morphology. We use this data-driven, structural function approach to investigate the spatial variability of the relative contribution of each component to the maximum TWL event on record. We also use a probabilistic, full simulation TWL model (Serafin and Ruggiero, 2014) to generate multiple, synthetic TWL records, to explore the relative contribution of each component to extreme TWL return levels. We assess the sensitivity to local beach morphology by computing TWLs for a range of observed beach slopes. Extreme TWLs are higher in Oregon and Washington than in California. Wave runup typically comprises > 50% of the TWL signal, while NTRs often compose < 5%, illustrating the importance wave climate has on the potential for extreme TWLs. While waves are typically larger in the North, California experiences greater contributions to extreme TWLs from

  14. Levels of lead in solvent and water-based paints manufactured in Pakistan

    International Nuclear Information System (INIS)

    Ikram, M.; Rauf, M.A.; Chotona, G.A.; Bukhari, N.

    2000-01-01

    The levels of lead in eight popular brands of solvent- and water-based paint manufactured locally in Pakistan are reported. The analysis was done using the flame Atomic Absorption Spectrophotometric method. The lead concentration was found to vary from 3.3 mg/kg to 13179 in different solvent-based brands, whereas the concentration of the metal was in the range of 1768 to less than 0.5mg/kg in water based paints. The lead concentrations were especially high in oil based green (maximum value of 13170 mg/kg) and yellow paints (maximum value of 84940 mg/kg). The corresponding higher concentration were observed in case of emerald (maximum value of 1768 mg/kg) and gray (maximum value of 542 mg/kg) paints in the water-based category. (author)

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

    International Nuclear Information System (INIS)

    Weigand, J.; Yamamoto, G.; Gaston, W.

    1987-01-01

    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

  16. Effect of temperature dependent properties on MHD convection of water near its density maximum in a square cavity

    International Nuclear Information System (INIS)

    Sivasankaran, S.; Hoa, C.J.

    2008-01-01

    Natural convection of water near its density maximum in the presence of magnetic field in a cavity with temperature dependent properties is studied numerically. The viscosity and thermal conductivity of the water is varied with reference temperature and calculated by cubic polynomial. The finite volume method is used to solve the governing equations. The results are presented graphically in the form of streamlines, isotherms and velocity vectors and are discussed for various combinations of reference temperature parameter, Rayleigh number, density inversion parameter and Hartmann number. It is observed that flow and temperature field are affected significantly by changing the reference temperature parameter for temperature dependent thermal conductivity and both temperature dependent viscosity and thermal conductivity cases. There is no significant effect on fluid flow and temperature distributions for temperature dependent viscosity case when changing the values of reference temperature parameter. The average heat transfer rate considering temperature-dependent viscosity are higher than considering temperature-dependent thermal conductivity and both temperature-dependent viscosity and thermal conductivity. The average Nusselt number decreases with an increase of Hartmann number. It is observed that the density inversion of water leaves strong effects on fluid flow and heat transfer due to the formation of bi-cellular structure. The heat transfer rate behaves non-linearly with density inversion parameter. The direction of external magnetic field also affect the fluid flow and heat transfer. (authors)

  17. Apparent molal volumes of HMT and TATD in aqueous solutions around the temperature of maximum density of water

    International Nuclear Information System (INIS)

    Clavijo Penagos, J.A.; Blanco, L.H.

    2012-01-01

    Highlights: ►V φ for HMT and TATD in aqueous solutions around the temperature of maximum density of water are reported. ► V φ is linear in m form m = 0.025 for all the aqueous solutions investigated. ► Variation of V ¯ 2 ∞ with T obeys a second grade polynomial trend. ► The solutes are classified as structure breakers according to Hepler’s criterion. - Abstract: Apparent molal volumes V φ have been determined from density measurements for several aqueous solutions of 1,3,5,7-tetraazatricyclo[3.3.1.1(3,7)]decane (HMT) and 1,3,6,8-tetraazatricyclo[4.4.1.1(3,8)]dodecane (TATD) at T = (275.15, 275.65, 276.15, 276.65, 277.15, 277.65 and 278.15) K as function of composition. The infinite dilution partial molar volumes of solutes in aqueous solution are evaluated through extrapolation. Interactions of the solutes with water are discussed in terms of the effect of the temperature on the volumetric properties and the structure of the solutes. The results are interpreted in terms of water structure-breaking or structure forming character of the solutes.

  18. Maximum permissible body burdens and maximum permissible concentrations of radionuclides in air and in water for occupational exposure. Recommendations of the National Committee on Radiation Protection. Handbook 69

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1959-06-05

    The present Handbook and its predecessors stem from the Second International Congress of Radiology, held in Stockholm in 1928. At that time, under the auspices of the Congress, the International Commission on Radiological Protection (ICRP) was organized to deal initially with problems of X-ray protection and later with radioactivity protection. At that time 'permissible' doses of X-rays were estimated primarily in terms of exposures which produced erythema, the amount of exposure which would produce a defined reddening of the skin. Obviously a critical problem in establishing criteria for radiation protection was one of developing useful standards and techniques of physical measurement. For this reason two of the organizations in this country with a major concern for X-ray protection, the American Roentgen Ray Society and the Radiology Society of North America, suggested that the National Bureau of Standards assume responsibility for organizing representative experts to deal with the problem. Accordingly, early in 1929, an Advisory Committee on X-ray and Radium Protection was organized to develop recommendations on the protection problem within the United States and to formulate United States points of view for presentation to the International Commission on Radiological Protection. The organization of the U.S. Advisory Committee included experts from both the medical and physical science fields. The recommendations of this Handbook take into consideration the NCRP statement entitled 'Maximum Permissible Radiation Exposures to Man', published as an addendum to Handbook 59 on April 15, 1958. As noted above this study was carried out jointly by the ICRP and the NCRP, and the complete report is more extensive than the material contained in this Handbook.

  19. Maximum permissible body burdens and maximum permissible concentrations of radionuclides in air and in water for occupational exposure. Recommendations of the National Committee on Radiation Protection. Handbook 69

    International Nuclear Information System (INIS)

    1959-01-01

    The present Handbook and its predecessors stem from the Second International Congress of Radiology, held in Stockholm in 1928. At that time, under the auspices of the Congress, the International Commission on Radiological Protection (ICRP) was organized to deal initially with problems of X-ray protection and later with radioactivity protection. At that time 'permissible' doses of X-rays were estimated primarily in terms of exposures which produced erythema, the amount of exposure which would produce a defined reddening of the skin. Obviously a critical problem in establishing criteria for radiation protection was one of developing useful standards and techniques of physical measurement. For this reason two of the organizations in this country with a major concern for X-ray protection, the American Roentgen Ray Society and the Radiology Society of North America, suggested that the National Bureau of Standards assume responsibility for organizing representative experts to deal with the problem. Accordingly, early in 1929, an Advisory Committee on X-ray and Radium Protection was organized to develop recommendations on the protection problem within the United States and to formulate United States points of view for presentation to the International Commission on Radiological Protection. The organization of the U.S. Advisory Committee included experts from both the medical and physical science fields. The recommendations of this Handbook take into consideration the NCRP statement entitled 'Maximum Permissible Radiation Exposures to Man', published as an addendum to Handbook 59 on April 15, 1958. As noted above this study was carried out jointly by the ICRP and the NCRP, and the complete report is more extensive than the material contained in this Handbook

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

    International Nuclear Information System (INIS)

    O'Brien, G.M.

    1993-01-01

    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

  1. Operational Principle of Water Level Detector for Agricultural and ...

    African Journals Online (AJOL)

    This paper proposes a design to automatically detect the level of water in a reservoir (storage tank) at a preset level and initializes an information to the users in case of low water level. The functionality of this sensor depends basically on the electrical conductivity of water (probes) which varies, depending on the level of its ...

  2. A rapid method for measuring maximum density temperatures in water and aqueous solutions for the study of quantum zero point energy effects in these liquids

    International Nuclear Information System (INIS)

    Deeney, F A; O'Leary, J P

    2008-01-01

    The connection between quantum zero point fluctuations and a density maximum in water and in liquid He 4 has recently been established. Here we present a description of a simple and rapid method of determining the temperatures at which maximum densities in water and aqueous solutions occur. The technique is such as to allow experiments to be carried out in one session of an undergraduate laboratory thereby introducing students to the concept of quantum zero point energy

  3. Water-level fluctuation in wetlands as a function of landscape condition in the prairie pothole region

    Science.gov (United States)

    Euliss, Ned H.; Mushet, David M.

    1996-01-01

    We evaluated water-level fluctuation (maximum water depth - minimum water depth/catchment size) in 12 temporary, 12 seasonal, and 12 semipermanent wetlands equally distributed among landscapes dominated by tilled agricultural lands and landscapes dominated by grassland. Water levels fluctuated an average of 14.14 cm in wetlands within tilled agricultural landscapes, while water levels in wetlands within grassland landscapes fluctuated an average of only 4.27 cm. Tillage reduces the natural capacity of catch meets to mitigate surface flow into wetland basins during precipitation events, resulting in greater water-level fluctuations in wetlands with tilled catchments. In addition, water levels in temporary and seasonal wetlands fluctuated an average of 13.74 cm and 11.82 cm, respectively, while water levels in semipermanent wetlands fluctuated only 2.77 cm. Semipermanent wetlands receive a larger proportion of their water as input from ground water than do either temporary or seasonal wetlands. This input of water from the ground has a stabilizing effect on water-levels of semipermanent wetlands. Increases in water-level fluctuation due to tillage or due to alteration of ground-water hydrology may ultimately affect the composition of a wetland's flora and fauna. In this paper, we also describe an inexpensive device for determining absolute maximum and minimum water levels in wetlands.

  4. Evaluating changes to reservoir rule curves using historical water-level data

    Science.gov (United States)

    Mower, Ethan; Miranda, Leandro E.

    2013-01-01

    Flood control reservoirs are typically managed through rule curves (i.e. target water levels) which control the storage and release timing of flood waters. Changes to rule curves are often contemplated and requested by various user groups and management agencies with no information available about the actual flood risk of such requests. Methods of estimating flood risk in reservoirs are not easily available to those unfamiliar with hydrological models that track water movement through a river basin. We developed a quantile regression model that uses readily available daily water-level data to estimate risk of spilling. Our model provided a relatively simple process for estimating the maximum applicable water level under a specific flood risk for any day of the year. This water level represents an upper-limit umbrella under which water levels can be operated in a variety of ways. Our model allows the visualization of water-level management under a user-specified flood risk and provides a framework for incorporating the effect of a changing environment on water-level management in reservoirs, but is not designed to replace existing hydrological models. The model can improve communication and collaboration among agencies responsible for managing natural resources dependent on reservoir water levels.

  5. 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.

  6. Water-level changes and directions of ground-water flow in the shallow aquifer, Fallon area, Churchill County, Nevada

    Science.gov (United States)

    Seiler, R.L.; Allander, K.K.

    1993-01-01

    The Truckee-Carson-Pyramid Lake Water Rights Settlement Act of 1990 directed the U.S. Fish and Wildlife Service to acquire water rights for wetland areas in the Carson Desert, Nevada. The public is concerned that htis acquisition of water rights and delivery of the water directly to wildlife areas would result in less recharge to the shallow ground water in the Fallon area and cause domestic wells to go dry. In January 1992, the U.S. Geological Survey, in cooperation with U.S. Fish and Wildlife Service, began a study of the shallow ground-water system in the Fallon area in Churchill County, Nevada. A network of 126 wells in the study area was monitored. Between January and November 1992, water levels in most wells declined, usually less than 2 feet. The maximum measured decline over this period was 2.68 feet in a well near Stillwater Marsh. Between April and July, however, water levels rose in irrigated areas, typically 1 to 2 feet. Newlands Project water deliveries to the study area began soon after the turn of the century. Since then, water levels have risen more than 15 feet across much of the study area. Water lost from unlined irrigtiaon canals caused the stage in Big Soda Lake to rise nearly 60 feet; ground-water levels near the lake have risen 30 to 40 feet. The depth to water in most irrigated areas is now less than 10 feet. The altitude of the water table ranges from 4.025 feet above sea level 11 miles west of Fallon to 3,865 feet in the Stillwater Marsh area. Ground water flows eastward and divides; some flow goes to the northeast toward the Carson Sink and Stillwater areas, and some goes southeastward to Carson Lake.

  7. Using spatially detailed water-quality data and solute-transport modeling to improve support total maximum daily load development

    Science.gov (United States)

    Walton-Day, Katherine; Runkel, Robert L.; Kimball, Briant A.

    2012-01-01

    Spatially detailed mass-loading studies and solute-transport modeling using OTIS (One-dimensional Transport with Inflow and Storage) demonstrate how natural attenuation and loading from distinct and diffuse sources control stream water quality and affect load reductions predicted in total maximum daily loads (TMDLs). Mass-loading data collected during low-flow from Cement Creek (a low-pH, metal-rich stream because of natural and mining sources, and subject to TMDL requirements) were used to calibrate OTIS and showed spatially variable effects of natural attenuation (instream reactions) and loading from diffuse (groundwater) and distinct sources. OTIS simulations of the possible effects of TMDL-recommended remediation of mine sites showed less improvement to dissolved zinc load and concentration (14% decrease) than did the TMDL (53-63% decrease). The TMDL (1) assumed conservative transport, (2) accounted for loads removed by remediation by subtracting them from total load at the stream mouth, and (3) did not include diffuse-source loads. In OTIS, loads were reduced near their source; the resulting concentration was decreased by natural attenuation and increased by diffuse-source loads during downstream transport. Thus, by not including natural attenuation and loading from diffuse sources, the TMDL overestimated remediation effects at low flow. Use of the techniques presented herein could improve TMDLs by incorporating these processes during TMDL development.

  8. Analysis of water-level fluctuations in Wisconsin wells

    Science.gov (United States)

    Patterson, G.L.; Zaporozec, A.

    1987-01-01

    More than 60 percent of the residents of Wisconsin use ground water as their primary water source. Water supplies presently are abundant, but ground-water levels continually fluctuate in response to natural factors and human-related stresses. A better understanding of the magnitude, duration, and frequency of past fluctuations, and the factors controlling these fluctuations may help anticipate future changes in ground-water levels.

  9. Evaluation of yield and water-level relations

    International Nuclear Information System (INIS)

    Cushman, R.L.; Purtymun, W.D.

    1975-10-01

    Yield and water relations in the Los Alamos supply wells were evaluated because of the increasing demand for water. Water-level declines were extrapolated for 10 yr, to 1983, on the basis of past records. On the basis of current pumpage, the extrapolations indicate that nonpumping water levels in individual wells will decline from 10 to 30 ft. Well characteristics were compiled to provide an individual history of each well, and recommendations for improving water production are presented

  10. New England SPARROW Water-Quality Modeling to Assist with the Development of Total Maximum Daily Loads in the Connecticut River Basin

    Science.gov (United States)

    Moore, R. B.; Robinson, K. W.; Simcox, A. C.; Johnston, C. M.

    2002-05-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency (USEPA) and the New England Interstate Water Pollution Control Commission (NEWIPCC), is currently preparing a water-quality model, called SPARROW, to assist in the regional total maximum daily load (TMDL) studies in New England. A model is required to provide estimates of nutrient loads and confidence intervals at unmonitored stream reaches. SPARROW (Spatially Referenced Regressions on Watershed Attributes) is a spatially detailed, statistical model that uses regression equations to relate total phosphorus and nitrogen (nutrient) stream loads to pollution sources and watershed characteristics. These statistical relations are then used to predict nutrient loads in unmonitored streams. The New England SPARROW model is based on a hydrologic network of 42,000 stream reaches and associated watersheds. Point source data are derived from USEPA's Permit Compliance System (PCS). Information about nonpoint sources is derived from data such as fertilizer use, livestock wastes, and atmospheric deposition. Watershed characteristics include land use, streamflow, time-of-travel, stream density, percent wetlands, slope of the land surface, and soil permeability. Preliminary SPARROW results are expected in Spring 2002. The New England SPARROW model is proposed for use in the TMDL determination for nutrients in the Connecticut River Basin, upstream of Connecticut. The model will be used to estimate nitrogen loads from each of the upstream states to Long Island Sound. It will provide estimates and confidence intervals of phosphorus and nitrogen loads, area-weighted yields of nutrients by watershed, sources of nutrients, and the downstream movement of nutrients. This information will be used to (1) understand ranges in nutrient levels in surface waters, (2) identify the environmental factors that affect nutrient levels in streams, (3) evaluate monitoring efforts for better determination of

  11. The determination of levels of mercury, cadmium and lead in water samples from Naivasha area, Kenya

    International Nuclear Information System (INIS)

    Muigai, P.G.; Kamau, G.N.; Kinyua, A.M.

    1995-01-01

    The analysis of mercury, cadmium and lead in water samples from different environments (Lake Naivasha, River Malewa boreholes and Olkaria geothermal wells) in Naivasha region and their possible origins are reported. The levels of mercury and lead in the water samples were above the maximum permissible limits of 0.005 mg/1 and 0.1 mg/1 respectively, as stipulated by the WHO. On the other hand, 83.3% of the samples had cadmium levels above the maximum permissible limit of 0.01mg/1 in drinking water by WHO. The mercury and lead levels were also higher than those previously obtained from different regions of Kenya, while those for cadmium were within the corresponding range. Possible sources of elevated values were the geology of the surrounding area, sewage treatment works, use of phosphate rock fertilizers and lead fuels.(author)

  12. Development of reactor water level sensor for extreme conditions

    Energy Technology Data Exchange (ETDEWEB)

    Miura, K; Ogasawara, T [Sukegawa Electric Co., Ltd., Hitachi, Ibaraki (Japan); Shibata, Akira; Nakamura, Jinichi; Saito, Takashi; Tsuchiya, Kunihiko [Japan Atomic Energy Agency, Oarai Research and Development Center, Oarai, Ibaraki (Japan)

    2012-03-15

    In the Fukushima accident, measurement failure of water level was one of the most important factors which caused serious situation. The differential pressure type water level indicators are widely used in various place of nuclear power plant but after the accident of TMI-2, the need of other reliable method has been required. The BICOTH type and the TRICOTH type water level indicator for light water power reactors had been developed for in-pile water level indicator but currently those are not adopted to nuclear power plant. In this study, the development of new type water level indicator composed of thermocouple and heater is described. Demonstration test and characteristic evaluation of the water level indicator were performed and we had obtained satisfactory results. (author)

  13. Maximum power point tracking for photovoltaic applications by using two-level DC/DC boost converter

    Science.gov (United States)

    Moamaei, Parvin

    Recently, photovoltaic (PV) generation is becoming increasingly popular in industrial applications. As a renewable and alternative source of energy they feature superior characteristics such as being clean and silent along with less maintenance problems compared to other sources of the energy. In PV generation, employing a Maximum Power Point Tracking (MPPT) method is essential to obtain the maximum available solar energy. Among several proposed MPPT techniques, the Perturbation and Observation (P&O;) and Model Predictive Control (MPC) methods are adopted in this work. The components of the MPPT control system which are P&O; and MPC algorithms, PV module and high gain DC-DC boost converter are simulated in MATLAB Simulink. They are evaluated theoretically under rapidly and slowly changing of solar irradiation and temperature and their performance is shown by the simulation results, finally a comprehensive comparison is presented.

  14. Statistical analysis and mapping of water levels in the Biscayne aquifer, water conservation areas, and Everglades National Park, Miami-Dade County, Florida, 2000–2009

    Science.gov (United States)

    Prinos, Scott T.; Dixon, Joann F.

    2016-02-25

    Statistical analyses and maps representing mean, high, and low water-level conditions in the surface water and groundwater of Miami-Dade County were made by the U.S. Geological Survey, in cooperation with the Miami-Dade County Department of Regulatory and Economic Resources, to help inform decisions necessary for urban planning and development. Sixteen maps were created that show contours of (1) the mean of daily water levels at each site during October and May for the 2000–2009 water years; (2) the 25th, 50th, and 75th percentiles of the daily water levels at each site during October and May and for all months during 2000–2009; and (3) the differences between mean October and May water levels, as well as the differences in the percentiles of water levels for all months, between 1990–1999 and 2000–2009. The 80th, 90th, and 96th percentiles of the annual maximums of daily groundwater levels during 1974–2009 (a 35-year period) were computed to provide an indication of unusually high groundwater-level conditions. These maps and statistics provide a generalized understanding of the variations of water levels in the aquifer, rather than a survey of concurrent water levels. Water-level measurements from 473 sites in Miami-Dade County and surrounding counties were analyzed to generate statistical analyses. The monitored water levels included surface-water levels in canals and wetland areas and groundwater levels in the Biscayne aquifer.

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

    International Nuclear Information System (INIS)

    Tucci, P.; Goemaat, R.L.; Burkhardt, D.J.

    1996-01-01

    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

  16. Accident analysis of railway transportation of low-level radioactive and hazardous chemical wastes: Application of the /open quotes/Maximum Credible Accident/close quotes/ concept

    Energy Technology Data Exchange (ETDEWEB)

    Ricci, E.; McLean, R.B.

    1988-09-01

    The maximum credible accident (MCA) approach to accident analysis places an upper bound on the potential adverse effects of a proposed action by using conservative but simplifying assumptions. It is often used when data are lacking to support a more realistic scenario or when MCA calculations result in acceptable consequences. The MCA approach can also be combined with realistic scenarios to assess potential adverse effects. This report presents a guide for the preparation of transportation accident analyses based on the use of the MCA concept. Rail transportation of contaminated wastes is used as an example. The example is the analysis of the environmental impact of the potential derailment of a train transporting a large shipment of wastes. The shipment is assumed to be contaminated with polychlorinated biphenyls and low-level radioactivities of uranium and technetium. The train is assumed to plunge into a river used as a source of drinking water. The conclusions from the example accident analysis are based on the calculation of the number of foreseeable premature cancer deaths the might result as a consequence of this accident. These calculations are presented, and the reference material forming the basis for all assumptions and calculations is also provided.

  17. Accident analysis of railway transportation of low-level radioactive and hazardous chemical wastes: Application of the /open quotes/Maximum Credible Accident/close quotes/ concept

    International Nuclear Information System (INIS)

    Ricci, E.; McLean, R.B.

    1988-09-01

    The maximum credible accident (MCA) approach to accident analysis places an upper bound on the potential adverse effects of a proposed action by using conservative but simplifying assumptions. It is often used when data are lacking to support a more realistic scenario or when MCA calculations result in acceptable consequences. The MCA approach can also be combined with realistic scenarios to assess potential adverse effects. This report presents a guide for the preparation of transportation accident analyses based on the use of the MCA concept. Rail transportation of contaminated wastes is used as an example. The example is the analysis of the environmental impact of the potential derailment of a train transporting a large shipment of wastes. The shipment is assumed to be contaminated with polychlorinated biphenyls and low-level radioactivities of uranium and technetium. The train is assumed to plunge into a river used as a source of drinking water. The conclusions from the example accident analysis are based on the calculation of the number of foreseeable premature cancer deaths the might result as a consequence of this accident. These calculations are presented, and the reference material forming the basis for all assumptions and calculations is also provided

  18. Suppression device for the reactor water level lowering

    International Nuclear Information System (INIS)

    Kasuga, Hajime; Kasuga, Hiroshi.

    1984-01-01

    Purpose: To suppress the lowering in the reactor water level so as to avoid unnecessary actuation of ECCS upon generation of transient changes which forecasts the lowering of the reactor water level in a BWR type reactor. Constitution: There are provided a water level suppression signal generator for generating a water level suppression signal upon generation of a transient change signal which forecasts the water level lowering in a nuclear reactor and a recycling flow rate controller that applies a recycling flow rate control signal to a recycling pump drive motor by the water level lowering suppression signal. The velocity of the recycling pump is controlled by a reactor scram signal by way of the water level lowering suppresion signal generator and a recycling flow rate controller. Then, the recycling reactor core flow rate is decreased and the void amount in the reactor is transiently increased where the water level tends to increase. Accordingly, the water level lowering by the scram is moderated by the increasing tendency of the water level. (Ikeda, J.)

  19. 36 CFR 3.15 - What is the maximum noise level for the operation of a vessel?

    Science.gov (United States)

    2010-07-01

    ... level for the operation of a vessel? 3.15 Section 3.15 Parks, Forests, and Public Property NATIONAL PARK... level for the operation of a vessel? (a) A person may not operate a vessel at a noise level exceeding... vessel is being operated in excess of the noise levels established in paragraph (a) of this section may...

  20. Influence of Last Glacial Maximum boundary conditions on the global water isotope distribution in an atmospheric general circulation model

    Directory of Open Access Journals (Sweden)

    T. Tharammal

    2013-03-01

    Full Text Available To understand the validity of δ18O proxy records as indicators of past temperature change, a series of experiments was conducted using an atmospheric general circulation model fitted with water isotope tracers (Community Atmosphere Model version 3.0, IsoCAM. A pre-industrial simulation was performed as the control experiment, as well as a simulation with all the boundary conditions set to Last Glacial Maximum (LGM values. Results from the pre-industrial and LGM simulations were compared to experiments in which the influence of individual boundary conditions (greenhouse gases, ice sheet albedo and topography, sea surface temperature (SST, and orbital parameters were changed each at a time to assess their individual impact. The experiments were designed in order to analyze the spatial variations of the oxygen isotopic composition of precipitation (δ18Oprecip in response to individual climate factors. The change in topography (due to the change in land ice cover played a significant role in reducing the surface temperature and δ18Oprecip over North America. Exposed shelf areas and the ice sheet albedo reduced the Northern Hemisphere surface temperature and δ18Oprecip further. A global mean cooling of 4.1 °C was simulated with combined LGM boundary conditions compared to the control simulation, which was in agreement with previous experiments using the fully coupled Community Climate System Model (CCSM3. Large reductions in δ18Oprecip over the LGM ice sheets were strongly linked to the temperature decrease over them. The SST and ice sheet topography changes were responsible for most of the changes in the climate and hence the δ18Oprecip distribution among the simulations.

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

    Science.gov (United States)

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

    2010-10-14

    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. 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. Pregnant women showed a decrease in methemoglobin levels with increasing gestation although nitrate intake from tap water among pregnant women around 36 weeks gestation (β = 0.046, p = 0.986). Four women had tap water nitrate levels above the MCL of 10 mg/L. At enrollment, a greater proportion of women who reported using water treatment devices were private wells users (66%) compared to public system users (46%) (p nitrate from water (p 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. Water levels in the Yucca Mountain Area, Nevada, 1996

    International Nuclear Information System (INIS)

    Graves, R.P.

    1998-01-01

    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

  3. Controlling taste and odour levels in water

    Energy Technology Data Exchange (ETDEWEB)

    Bowers, A J

    1980-12-01

    Taste and odor of drinking water supplies act as indicator mechanisms, indicating increased degrees of biological activity, possible contamination of the supply, treatment inadequacies, or contamination of the distribution systems. Disinfection and coagulation are effective preventive measures. Taste and odor problems may arise even with the application of preventive measures, so protective and treatment techniques must be implemented. These include chlorination and activated carbon absorption. (1 photo, 3 references, 1 table)

  4. Lake Erie Water Level Study. Main Report.

    Science.gov (United States)

    1981-07-01

    indirectly through excessive turbidity, current or depth would impact the higher life forms. Phytoplankton , periphyton and aquatic macrophyte comprise...System. The hydro-electric interest relates to the facilities at the St. Marys River, Welland Canal, Niagara River, St. Lawrence River at Cornwall... relates to three components: water quality, fish, and wildlife. The economic evaluations of regulation plans were also made to determine effects on

  5. Direct comparison of phase-sensitive vibrational sum frequency generation with maximum entropy method: case study of water.

    Science.gov (United States)

    de Beer, Alex G F; Samson, Jean-Sebastièn; Hua, Wei; Huang, Zishuai; Chen, Xiangke; Allen, Heather C; Roke, Sylvie

    2011-12-14

    We present a direct comparison of phase sensitive sum-frequency generation experiments with phase reconstruction obtained by the maximum entropy method. We show that both methods lead to the same complex spectrum. Furthermore, we discuss the strengths and weaknesses of each of these methods, analyzing possible sources of experimental and analytical errors. A simulation program for maximum entropy phase reconstruction is available at: http://lbp.epfl.ch/. © 2011 American Institute of Physics

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

    International Nuclear Information System (INIS)

    Graves, R.P.; Goemaat, R.L.

    1998-01-01

    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

  7. Suitability of the charm HVS and a microbiological multiplate system for detection of residues in raw milk at EU maximum residue levels

    NARCIS (Netherlands)

    Nouws, J.F.M.; Egmond, van H.; Loeffen, G.; Schouten, J.; Keukens, H.; Smulders, I.; Stegeman, H.

    1999-01-01

    In this paper we assessed the suitability of the Charm HVS and a newly developed microbiological multiplate system as post-screening tests to confirm the presence of residues in raw milk at or near the maximum permissible residue level (MRL). The multiplate system is composed of Bacillus

  8. The Effects of a Maximal Power Training Cycle on the Strength, Maximum Power, Vertical Jump Height and Acceleration of High-Level 400-Meter Hurdlers

    Science.gov (United States)

    Balsalobre-Fernández, Carlos; Tejero-González, Carlos Mª; del Campo-Vecino, Juan; Alonso-Curiel, Dionisio

    2013-01-01

    The aim of this study was to determine the effects of a power training cycle on maximum strength, maximum power, vertical jump height and acceleration in seven high-level 400-meter hurdlers subjected to a specific training program twice a week for 10 weeks. Each training session consisted of five sets of eight jump-squats with the load at which each athlete produced his maximum power. The repetition maximum in the half squat position (RM), maximum power in the jump-squat (W), a squat jump (SJ), countermovement jump (CSJ), and a 30-meter sprint from a standing position were measured before and after the training program using an accelerometer, an infra-red platform and photo-cells. The results indicated the following statistically significant improvements: a 7.9% increase in RM (Z=−2.03, p=0.021, δc=0.39), a 2.3% improvement in SJ (Z=−1.69, p=0.045, δc=0.29), a 1.43% decrease in the 30-meter sprint (Z=−1.70, p=0.044, δc=0.12), and, where maximum power was produced, a change in the RM percentage from 56 to 62% (Z=−1.75, p=0.039, δc=0.54). As such, it can be concluded that strength training with a maximum power load is an effective means of increasing strength and acceleration in high-level hurdlers. PMID:23717361

  9. Hydrological forecast of maximal water level in Lepenica river basin and flood control measures

    Directory of Open Access Journals (Sweden)

    Milanović Ana

    2006-01-01

    Full Text Available Lepenica river basin territory has became axis of economic and urban development of Šumadija district. However, considering Lepenica River with its tributaries, and their disordered river regime, there is insufficient of water for water supply and irrigation, while on the other hand, this area is suffering big flood and torrent damages (especially Kragujevac basin. The paper presents flood problems in the river basin, maximum water level forecasts, and flood control measures carried out until now. Some of the potential solutions, aiming to achieve the effective flood control, are suggested as well.

  10. 40 CFR Table 2 to Subpart Ggggg of... - Control Levels as Required by § 63.7895(a) for Tanks Managing Remediation Material With a Maximum...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 13 2010-07-01 2010-07-01 false Control Levels as Required by § 63.7895(a) for Tanks Managing Remediation Material With a Maximum HAP Vapor Pressure Less Than 76.6 kPa 2..., Subpt. GGGGG, Table 2 Table 2 to Subpart GGGGG of Part 63—Control Levels as Required by § 63.7895(a) for...

  11. Recommendation of maximum allowable noise levels for offshore wind power systems; Empfehlung von Laermschutzwerten bei der Errichtung von Offshore-Windenergieanlagen (OWEA)

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Stefanie [Umweltbundesamt, Dessau-Rosslau (Germany). Fachgebiet II 2.3

    2011-05-15

    When offshore wind farms are constructed, every single pile is hammered into the sediment by a hydraulic hammer. Noise levels at Horns Reef wind farm were in the range of 235 dB. The noise may cause damage to the auditory system of marine mammals. The Federal Environmental Office therefore recommends the definition of maximum permissible noise levels. Further, care should be taken that no marine mammals are found in the immediate vicinity of the construction site. (AKB)

  12. Critical water stress levels in Pinus patula seedlings and their ...

    African Journals Online (AJOL)

    Critical water stress levels in Pinus patula seedlings and their relation to measures of seedling morphology. ... Southern Forests: a Journal of Forest Science ... A pot trial was implemented to determine the effect of soil water stress following transplanting on shoot water potential and stomatal conductance of Pinus patula ...

  13. Radio Frequency Based Water Level Monitor and Controller for ...

    African Journals Online (AJOL)

    Similarly, the control unit of the prototype performs automatic switching control of on and off on a single phase centrifugal water pump, 220volts, 0.5hp motor via a motor driver circuit (relay). It also incorporates a buzzer that beeps briefly when water level hits 100%, thus causing the pump to be switched off but when water ...

  14. Secondary poisoning of cadmium, copper and mercury: implications for the Maximum Permissible Concentrations and Negligible Concentrations in water, sediment and soil

    NARCIS (Netherlands)

    Smit CE; van Wezel AP; Jager T; Traas TP; CSR

    2000-01-01

    De betekenis van doorvergiftiging voor de Maximum Toelaatbaar Risiconiveau's (MTRs) en Verwaarloosbaar Risiconiveau's (VRs) van cadmium, koper en kwik in water, sediment en bodem is geevalueerd. Veldgegevens met betrekking tot de accumulatie van deze elementen door vissen, mosselen en

  15. Secondary poisoning of cadmium, copper and mercury: implications for the Maximum Permissible Concentrations and Negligible Concentrations in water, sediment and soil

    NARCIS (Netherlands)

    Smit CE; Wezel AP van; Jager T; Traas TP; CSR

    2000-01-01

    The impact of secondary poisoning on the Maximum Permissible Concentrations (MPCs) and Negligible Concentrations (NCs) of cadmium, copper and mercury in water, sediment and soil have been evaluated. Field data on accumulation of these elements by fish, mussels and earthworms were used to derive

  16. Short-time variations of the ground water level

    International Nuclear Information System (INIS)

    Nilsson, Lars Y.

    1977-09-01

    Investigations have demonstrated that the ground water level of aquifers in the Swedish bedrock shows shorttime variations without changing their water content. The ground water level is among other things affected by regular tidal movements occuring in the ''solid'' crust of the earth variations in the atmospheric pressure strong earthquakes occuring in different parts of the world These effects proves that the system of fissures in the bedrock are not stable and that the ground water flow is influenced by both water- and airfilled fissures

  17. [Arsenic levels in drinking water supplies from underground sources in the community of Madrid].

    Science.gov (United States)

    Aragonés Sanz, N; Palacios Diez, M; Avello de Miguel, A; Gómez Rodríguez, P; Martínez Cortés, M; Rodríguez Bernabeu, M J

    2001-01-01

    In 1998, arsenic concentrations of more than 50 micrograms/l were detected in some drinking water supplies from underground sources in the Autonomous Community of Madrid, which is the maximum permissible concentration for drinking water in Spain. These two facts have meant the getting under way of a specific plan for monitoring arsenic in the drinking water in the Autonomous Community of Madrid. The results of the first two sampling processes conducted in the arsenic level monitoring plan set out are presented. In the initial phase, water samples from 353 water supplies comprised within the census of the Public Health Administration of the Autonomous Community of Madrid were analyzed. A water supply risk classification was made based on these initial results. In a second phase, six months later, the analyses were repeated on those 35 water supplies which were considered to possibly pose a risk to public health. Seventy-four percent (74%) of the water supplies studied in the initial phase were revealed to have an arsenic concentration of less than 10 micrograms/l, 22.6% containing levels of 10 micrograms/l-50 micrograms/l, and 3.7% over 50 micrograms/l. Most of the water supplies showing arsenic levels of more than 10 micrograms/l are located in the same geographical area. In the second sampling process (six months later), the 35 water supplies classified as posing a risk were included. Twenty-six (26) of these supplies were revealed to have the same arsenic level ((10-50 micrograms/l), and nine changed category, six of which had less than 10 micrograms/l and three more than 50 micrograms/l. In the Autonomous Community of Madrid, less than 2% of the population drinks water coming from supplies which are from underground sources. The regular water quality monitoring conducted by the Public Health Administration has led to detecting the presence of more than 50 micrograms/l of arsenic in sixteen drinking water supplies from underground sources, which is the maximum

  18. Contamination levels of domestic water sources in Maiduguri ...

    African Journals Online (AJOL)

    The study examines the levels of contamination of domestic water sources in Maiduguri Metropolis area of Borno State based on their physicochemical and bacteriological properties. It was informed by the global concern on good drinking water quality which is an indicator of development level; hence the focus on domestic ...

  19. The consequences of a reduction in the administratively applied maximum annual dose equivalent level for an individual in a group of occupationally exposed workers

    International Nuclear Information System (INIS)

    Harrison, N.T.

    1980-02-01

    An analysis is described for predicting the consequences of a reduction in the administratively applied maximum dose equivalent level to individuals in a group of workers occupationally exposed to ionising radiations, for the situation in which no changes are made to the working environment. This limitation of the maximum individual dose equivalent is accommodated by allowing the number of individuals in the working group to increase. The derivation of the analysis is given, together with worked examples, which highlight the important assumptions that have been made and the conclusions that can be drawn. The results are obtained in the form of the capacity of the particular working environment to accommodate the limitation of the maximum individual dose equivalent, the increase in the number of workers required to carry out the productive work and any consequent increase in the occupational collective dose equivalent. (author)

  20. Research on network maximum flows algorithm of cascade level graph%级连层次图的网络最大流算法研究

    Institute of Scientific and Technical Information of China (English)

    潘荷新; 伊崇信; 李满

    2011-01-01

    给出一种通过构造网络级连层次图的方法,来间接求出最大网络流的算法.对于给定的有n个顶点,P条边的网络N=(G,s,t,C),该算法可在O(n2)时间内快速求出流经网络N的最大网络流及达最大流时的网络流.%This paper gives an algoritm that structures a network cascade level graph to find out maximum flow of the network indirectly.For the given network N=(G,s,t,C) that has n vetexes and e arcs,this algorithm finds out the maximum value of the network flow fast in O(n2) time that flows from the network N and the network flows when the value of the one reach maximum.

  1. Perfluorinated compounds: Levels, trophic web enrichments and human dietary intakes in transitional water ecosystems

    International Nuclear Information System (INIS)

    Renzi, Monia; Guerranti, Cristiana; Giovani, Andrea; Perra, Guido; Focardi, Silvano E.

    2013-01-01

    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

  2. Air Pollution Modelling to Predict Maximum Ground Level Concentration for Dust from a Palm Oil Mill Stack

    Directory of Open Access Journals (Sweden)

    Regina A. A.

    2010-12-01

    Full Text Available The study is to model emission from a stack to estimate ground level concentration from a palm oil mill. The case study is a mill located in Kuala Langat, Selangor. Emission source is from boilers stacks. The exercise determines the estimate the ground level concentrations for dust to the surrounding areas through the utilization of modelling software. The surround area is relatively flat, an industrial area surrounded by factories and with palm oil plantations in the outskirts. The model utilized in the study was to gauge the worst-case scenario. Ambient air concentrations were garnered calculate the increase to localized conditions. Keywords: emission, modelling, palm oil mill, particulate, POME

  3. A Two-Stage Information-Theoretic Approach to Modeling Landscape-Level Attributes and Maximum Recruitment of Chinook Salmon in the Columbia River Basin.

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, William L.; Lee, Danny C.

    2000-11-01

    Many anadromous salmonid stocks in the Pacific Northwest are at their lowest recorded levels, which has raised questions regarding their long-term persistence under current conditions. There are a number of factors, such as freshwater spawning and rearing habitat, that could potentially influence their numbers. Therefore, we used the latest advances in information-theoretic methods in a two-stage modeling process to investigate relationships between landscape-level habitat attributes and maximum recruitment of 25 index stocks of chinook salmon (Oncorhynchus tshawytscha) in the Columbia River basin. Our first-stage model selection results indicated that the Ricker-type, stock recruitment model with a constant Ricker a (i.e., recruits-per-spawner at low numbers of fish) across stocks was the only plausible one given these data, which contrasted with previous unpublished findings. Our second-stage results revealed that maximum recruitment of chinook salmon had a strongly negative relationship with percentage of surrounding subwatersheds categorized as predominantly containing U.S. Forest Service and private moderate-high impact managed forest. That is, our model predicted that average maximum recruitment of chinook salmon would decrease by at least 247 fish for every increase of 33% in surrounding subwatersheds categorized as predominantly containing U.S. Forest Service and privately managed forest. Conversely, mean annual air temperature had a positive relationship with salmon maximum recruitment, with an average increase of at least 179 fish for every increase in 2 C mean annual air temperature.

  4. Spatio-temporal distribution of Diaphanosoma brachyurum (Cladocera: Sididae in freshwater reservoir ecosystems: importance of maximum water depth and macrophyte beds for avoidance of fish predation

    Directory of Open Access Journals (Sweden)

    Jong-Yun Choi

    2014-10-01

    Full Text Available In empirical studies, Cladocera is commonly utilized as a primary food source for predators such as fish, thus, predator avoidance are important strategies to sustain their population in freshwater ecosystems. In this study, we tested the hypothesis that water depth is an important factor in determining the spatial distribution of Diaphanosoma brachyurum Liévin, 1848 in response to fish predation. Quarterly monitoring was implemented at three water layers (i.e., water surface and middle and bottom layers in 21 reservoirs located in the southeastern part of South Korea. D. brachyurum individuals were frequently observed at the study sites and exhibited different spatial patterns of distribution in accordance with the maximum depth of the reservoirs. In the reservoirs with a maximum depth of more than 6 m, high densities of D. brachyurum were observed in the bottom layers; however, in the shallower reservoirs (maximum depth <6 m, D. brachyurum were concentrated in the surface layer. Moreover, during additional surveys, we observed a trend in which D. brachyurum densities increased as the maximum depth or macrophyte biomass increased. Gut contents analysis revealed that predatory fishes in each reservoir frequently consumed D. brachyurum; however, the consumption rate abruptly decreased in reservoirs where the maximum depth was more than 11 m or in the shallow reservoirs supporting a macrophyte bed. Interestingly, the reservoirs more than 11-m depth supported high densities of D. brachyurum in the bottom layer and in the surface macrophyte bed. Based on these results, reservoirs with a maximum depth of more than 11 m or those with a macrophyte bed may provide a refuge for D. brachyurum to avoid fish predation. Compared with other cladoceran species, D. brachyurum readily exploits various types of refugia (in this study, the deep layer or surface macrophyte bed, which may help explain why this species is abundant in various types of reservoirs.

  5. Denitrifying Bioreactors Resist Disturbance from Fluctuating Water Levels

    Directory of Open Access Journals (Sweden)

    Sarah K. Hathaway

    2017-06-01

    Full Text Available Nitrate can be removed from wastewater streams, including subsurface agricultural drainage systems, using woodchip bioreactors to promote microbial denitrification. However, the variations in water flow in these systems could make reliable performance from this microbially-mediated process a challenge. In the current work, the effects of fluctuating water levels on nitrate removal, denitrifying activity, and microbial community composition in laboratory-scale bioreactors were investigated. The performance was sensitive to changing water level. An average of 31% nitrate was removed at high water level and 59% at low water level, despite flow adjustments to maintain a constant theoretical hydraulic retention time. The potential activity, as assessed through denitrifying enzyme assays, averaged 0.0008 mg N2O-N/h/dry g woodchip and did not show statistically significant differences between reactors, sampling depths, or operational conditions. In the denitrifying enzyme assays, nitrate removal consistently exceeded nitrous oxide production. The denitrifying bacterial communities were not significantly different from each other, regardless of water level, meaning that the denitrifying bacterial community did not change in response to disturbance. The overall bacterial communities, however, became more distinct between the two reactors when one reactor was operated with periodic disturbances of changing water height, and showed a stronger effect at the most severely disturbed location. The communities were not distinguishable, though, when comparing the same location under high and low water levels, indicating that the communities in the disturbed reactor were adapted to fluctuating conditions rather than to high or low water level. Overall, these results describe a biological treatment process and microbial community that is resistant to disturbance via water level fluctuations.

  6. Modelling soil water dynamics and crop water uptake at the field level

    NARCIS (Netherlands)

    Kabat, P.; Feddes, R.A.

    1995-01-01

    Parametrization approaches to model soil water dynamics and crop water uptake at field level were analysed. Averaging and numerical difficulties in applying numerical soil water flow models to heterogeneous soils are highlighted. Simplified parametrization approaches to the soil water flow, such as

  7. Velocity flow field and water level measurements in shoaling and breaking water waves

    CSIR Research Space (South Africa)

    Mukaro, R

    2010-01-01

    Full Text Available In this paper we report on the laboratory investigations of breaking water waves. Measurements of the water levels and instantaneous fluid velocities were conducted in water waves breaking on a sloping beach within a glass flume. Instantaneous water...

  8. A study of full width at half maximum (FWHM) according to the filter's cut off level in SPECT camera

    International Nuclear Information System (INIS)

    Park, Soung Ock; Kwon, Soo Il

    2003-01-01

    Filtering is necessary to reduce statistical noise and to increase image quality in SPECT images. Noises controlled by low-pass filter designed to suppress high spatial frequency in SPECT image. Most SPECT filter function control the degree of high frequency suppression by choosing a cut off frequency. The location of cut off frequency determines the affect image noise and spatial resolution. If select the low cut off frequency, its provide good noise suppression but insufficient image quantity and high cut off frequencies increase the image resolution but insufficient noise suppression. The purpose of this study was to determines the optimum cut off level with comparison of FWHM according to cut off level in each filters-Band-limited, Sheep-logan, Sheep-logan Hanning, Generalized Hamming, Low pass cosine, Parazen and Butterworth filter in SPECT camera. We recorded image along the X, Y, Z-axis with 99m TcO 4 point source and measured FWHM by use profile curve. We find averaged length is 9.16 mm ∼ 18.14 mm of FWHM in X, Y, and Z-axis, and Band-limited and Generalized Hamming filters measures 9.16 mm at 0.7 cycle/pixel cut off frequency

  9. 75 FR 20351 - Clean Water Act Section 303(d): Availability of One Total Maximum Daily Load (TMDL) in Arkansas

    Science.gov (United States)

    2010-04-19

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9139-5] Clean Water Act Section 303(d): Availability of One...: Notice of availability. SUMMARY: This notice announces the availability of the administrative record file... in the State of Arkansas under Section 303(d) of the Clean Water Act (CWA). This TMDL was completed...

  10. 75 FR 8698 - Clean Water Act Section 303(d): Availability of Ten Total Maximum Daily Loads (TMDLs) in Louisiana

    Science.gov (United States)

    2010-02-25

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9118-5] Clean Water Act Section 303(d): Availability of Ten...: Notice of availability. SUMMARY: This notice announces the availability for comment on the administrative... Smith, Environmental Protection Specialist, Water Quality Protection Division, U.S. Environmental...

  11. 76 FR 76161 - Clean Water Act Section 303(d): Availability of Three Total Maximum Daily Loads (TMDLs) in Louisiana

    Science.gov (United States)

    2011-12-06

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9500-1] Clean Water Act Section 303(d): Availability of Three...: Notice of availability. SUMMARY: This notice announces the availability for comment on the administrative... Smith, Environmental Protection Specialist, Water Quality Protection Division, U.S. Environmental...

  12. 76 FR 70442 - Clean Water Act Section 303(d): Availability of 28 Total Maximum Daily Loads (TMDLs) in Louisiana

    Science.gov (United States)

    2011-11-14

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9491-1] Clean Water Act Section 303(d): Availability of 28...: Notice of availability. SUMMARY: This notice announces the availability for comment on the administrative..., Environmental Protection Specialist, Water Quality Protection Division, U.S. Environmental Protection Agency...

  13. 76 FR 77226 - Clean Water Act Section 303(d): Availability of 28 Total Maximum Daily Loads (TMDLs) in Louisiana

    Science.gov (United States)

    2011-12-12

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9505-4] Clean Water Act Section 303(d): Availability of 28... public comment period for the notice of availability that published on November 14, 2011, 76 FR 70442... Protection Specialist, Water Quality Protection Division, U.S. Environmental Protection Agency Region 6, 1445...

  14. 76 FR 80366 - Clean Water Act Section 303(d): Availability of One Total Maximum Daily Load (TMDL) in Louisiana

    Science.gov (United States)

    2011-12-23

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9610-6] Clean Water Act Section 303(d): Availability of One...: Notice of availability. SUMMARY: This notice announces the availability for comment on the administrative..., Environmental Protection Specialist, Water Quality Protection Division, U.S. Environmental Protection Agency...

  15. Measurement of low levels of cesium-137 in water

    International Nuclear Information System (INIS)

    Milham, R.C.; Kantelo, M.V.

    1984-10-01

    Large volume water sampling systems were developed to measure very low levels of cesium-137 in river water and in finished water from water treatment plants. Three hundred to six hundred liters of filtered water are passed through the inorganic ion exchanger potassium cobalti-ferrocyanide to remove greater than 90% of the cesium. Measurement of cesium-137 by gamma ray spectrometry results in a sensitivity of 0.001 pCi/L. Portable as well as stationary samplers were developed to encompass a variety of applications. Results of a one year study of water from the Savannah River and from water treatment plants processing Savannah River water are presented. 3 references, 7 figures

  16. Effects of Water Level Increase on Phytoplankton Assemblages in a Drinking Water Reservoir

    Directory of Open Access Journals (Sweden)

    Yangdong Pan

    2018-03-01

    Full Text Available Excessive water level fluctuation may affect physico-chemical characteristics, and consequently ecosystem function, in lakes and reservoirs. In this study, we assessed the changes of phytoplankton assemblages in response to water level increase in Danjiangkou Reservoir, one of the largest drinking water reservoirs in Asia. The water level increased from a low of 137 m to 161 m in 2014 as a part of the South–North Water Diversion Project. Phytoplankton assemblages were sampled four times per year before, during and after the water level increase, at 10 sites. Environmental variables such as total nitrogen as well as phytoplankton biomass decreased after the water level increase. Non-metric multi-dimensional scaling analysis indicated that before the water level increase, phytoplankton assemblages showed distinct seasonal variation with diatom dominance in both early and late seasons while such seasonal variation was much less evident after the water level increase. Month and year (before and after explained 13% and 6% of variance in phytoplankton assemblages (PERMANOVA, p < 0.001 respectively, and phytoplankton assemblages were significantly different before and after the water level increase. Both chlorophytes and cyanobacteria became more abundant in 2015. Phytoplankton compositional change may largely reflect the environmental changes, such as hydrodynamics mediated by the water level increase.

  17. RIP Input Tables From WAPDEG for LA Design Selection: Repository Horizon Elevation - 2-Level AML 50% and Near Maximum

    International Nuclear Information System (INIS)

    B.E. Bullard

    1999-01-01

    The purpose of this calculation is to document the WAPDEG version 3.09 (CRWMS M and O 1998b). Software Routine Report for WAPDEG (Version 3.09) simulations used to analyze waste package degradation and failure under the repository exposure conditions characterized by a two-tier thermal loading repository design. Also documented is the post-processing of these results into tables of waste-package-degradation-time histories suitable for use as input into the Integrated Probabilistic Simulator for Environmental Systems (RIP) version 5.19.01 (Golder Associates 1998) computer program. Specifically, the WAPDEG simulations discussed in this calculation correspond to waste package emplacement conditions (repository environment and design) as defined in the Total System Performance Assessment-Viability Assessment (CRWMS M and O 1998a). Total System Performance Assessment-Viability Assessment (TSPA-VA) Analyses Technical Basis Document--Chapter 5, Waste Package Degradation Modeling And Abstraction, pp. 5-27 to 5-29, with the exception that a two-tier thermal loading design feature as specified in the License Application Design Selection (LADS) study was analyzed. The particular design feature evaluated in this report is a modification of the repository horizon elevation and layout within the Topopah Springs Member of Yucca Mountain. Specifically, the modification consists of adding a second level, 50-m above the base case repository layout. Two options were considered, representing two variations in thermal loading. In Design Feature 25e (designated DF25e), each level has an Areal Mass Loading (AML) of 42.5 MTU/acre (i.e., half the VA base case). In Design Feature 25f (designated DF25), each level has an AML of 64MTU/acre. As a result of the change in waste package placement relative to the TSPA-VA base-case design, different temperature and relative humidity time histories at the waste package surface are calculated (input to the WAPDEG simulations), and consequently

  18. Levels of toxaphene congeners in fish from Danish waters

    DEFF Research Database (Denmark)

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

    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 Western Baltic Sea being different from the other waters by having almost equal levels of toxaphene...

  19. Evaluate prevailing climate change on Great Lakes water levels

    International Nuclear Information System (INIS)

    Islam, M.

    2009-01-01

    'Full text:'In this paper, results of a comprehensive water mass balance modeling for the Great Lakes against prevailing and different anticipated climate change scenarios would be presented. Modeling is done in evaluating the changes in the lake storages and then changes in the lake's water level considering present condition, uncertainty and variability of climate and hydrologic conditions in the future. Inflow-outflow and consequent changes in the five Great Lake's storages are simulated for the last 30 years and then projected to evaluate the changes in the lake storages for the next 50 years. From the predicted changes in the lake storage data, water level is calculated using mass to linear conversion equation. Modeling and analysis results are expected to be helpful in understanding the possible impacts of the climate change on the Great Lakes water environment and preparing strategic plan for the sustainable management of lake's water resources. From the recent past, it is observed that there is a depleting trend in the lakes water level and hence there is a potential threat to lake's water environment and uncertainty of the availability of quality and quantity of water for the future generations, especially against prevailing and anticipated climate changes. For this reason, it is an urgent issue of understanding and quantifying the potential impacts of climate change on the Great Lake's water levels and storages. (author)

  20. Auto Detection For High Level Water Content For Oil Well

    Science.gov (United States)

    Janier, Josefina Barnachea; Jumaludin, Zainul Arifin B.

    2010-06-01

    Auto detection of high level water content for oil well is a system that measures the percentage of water in crude oil. This paper aims to discuss an auto detection system for measuring the content of water level in crude oil which is applicable for offshore and onshore oil operations. Data regarding water level content from wells can be determined by using automation thus, well with high water level can be determined immediately whether to be closed or not from operations. Theoretically the system measures the percentage of two- fluid mixture where the fluids have different electrical conductivities which are water and crude oil. The system made use of grid sensor which is a grid pattern like of horizontal and vertical wires. When water occupies the space at the intersection of vertical and horizontal wires, an electrical signal is detected which proved that water completed the circuit path in the system. The electrical signals are counted whereas the percentage of water is determined from the total electrical signals detected over electrical signals provided. Simulation of the system using the MultiSIM showed that the system provided the desired result.

  1. 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)...

  2. Ground-water levels and quality data for Georgia

    Science.gov (United States)

    ,

    1979-01-01

    This report begins a publication format that will present annually both water-level and water-quality data in Georgia. In this format the information is presented in two-page units: the left page includes text which summarizes the information for an area or subject and the right page consists of one or more illustrations. Daily mean water-level fluctuations and trends are shown in hydrographs for the previous year and fluctuations for the monthly mean water level the previous 10 years for selected observation wells. The well data best illustrate the effects of changes in recharge and discharge in the various ground-water reservoirs in the State. A short narrative explains fluctuations and trends in each hydrograph. (Woodard-USGS)

  3. 75 FR 43160 - Clean Water Act Section 303(d): Final Agency Action on One Arkansas Total Maximum Daily Load (TMDL)

    Science.gov (United States)

    2010-07-23

    ... taking final agency action on the following TMDL for waters located within the State of Arkansas: Segment-reach Waterbody name Pollutant 11070208-901 Town Branch..... Total Phosphorus. EPA requested the public...

  4. Experience of water chemistry and radiation levels in Swedish BWRs

    International Nuclear Information System (INIS)

    Ivars, R.; Elkert, J.

    1981-01-01

    From the BWR operational experience in Sweden it has been found that the occupational radiation exposures have been comparatively low in an international comparison. One main reason for the favourable conditions is the good water chemistry performance. This paper deals at first with the design considerations of water chemistry and materials selection. Next, the experience of water chemistry and radiation levels are provided. Finally, some methods to further reduce the radiation sources are discussed. (author)

  5. Carboxyhaemoglobin levels in water-pipe and cigarette smokers ...

    African Journals Online (AJOL)

    South African Medical Journal ... 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 ... We aimed to measure carboxyhaemoglobin (COHb) blood levels before and after water-pipe and cigarette smoking sessions.

  6. Socio–economic benefits and pollution levels of water resources ...

    African Journals Online (AJOL)

    Communities are dependent on wetlands resources for income generation. However, anthropogenic activities that result into pollution of water are one of the major public health problems. Assessment of socio–economic activities and pollution levels of domestic water sources in Gulu Municipality, Pece wetland was done.

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

    International Nuclear Information System (INIS)

    Mao, Cheng-Hsin; Weng, Pao-Shan

    2000-01-01

    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 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 3 , while the second caused even higher radon level as high as 772 Bq/m 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)

  8. Trace-level mercury removal from surface water

    International Nuclear Information System (INIS)

    Klasson, K.T.; Bostick, D.T.

    1998-01-01

    Many sorbents have been developed for the removal of mercury and heavy metals from waters; however, most of the data published thus far do not address the removal of mercury to the target levels represented in this project. The application to which these sorbents are targeted for use is the removal of mercury from microgram-per-liter levels to low nanogram-per-liter levels. Sorbents with thiouronium, thiol, amine, sulfur, and proprietary functional groups were selected for these studies. Mercury was successfully removed from surface water via adsorption onto Ionac SR-4 and Mersorb resins to levels below the target goal of 12 ng/L in batch studies. A thiol-based resin performed the best, indicating that over 200,000 volumes of water could be treated with one volume of resin. The cost of the resin is approximately $0.24 per 1,000 gal of water

  9. 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...

  10. 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)....

  11. 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...

  12. radio frequency based radio frequency based water level monitor

    African Journals Online (AJOL)

    eobe

    ABSTRACT. This paper elucidates a radio frequency (RF) based transmission and reception system used to remotely monitor and .... range the wireless can cover but in this prototype, it ... power supply to the system, the sensed water level is.

  13. 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)....

  14. 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...

  15. Radioactivity levels in well water supplies within the greater Chicago area

    International Nuclear Information System (INIS)

    Kristoff, L.M.; Lordi, D.T.; Lue-Hing, C.

    1976-01-01

    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

  16. Maximum Acceleration Recording Circuit

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1995-01-01

    Coarsely digitized maximum levels recorded in blown fuses. Circuit feeds power to accelerometer and makes nonvolatile record of maximum level to which output of accelerometer rises during measurement interval. In comparison with inertia-type single-preset-trip-point mechanical maximum-acceleration-recording devices, circuit weighs less, occupies less space, and records accelerations within narrower bands of uncertainty. In comparison with prior electronic data-acquisition systems designed for same purpose, circuit simpler, less bulky, consumes less power, costs and analysis of data recorded in magnetic or electronic memory devices. Circuit used, for example, to record accelerations to which commodities subjected during transportation on trucks.

  17. Negotiating water across levels: A peace and conflict "Toolbox" for water diplomacy

    Science.gov (United States)

    Grech-Madin, Charlotte; Döring, Stefan; Kim, Kyungmee; Swain, Ashok

    2018-04-01

    As a key policy tool, water diplomacy offers greater political engagement in the cooperative management of shared water. A range of initiatives has been dedicated to this end, almost invariably oriented around the interactions of nation states. Crucially, however, practitioners of water diplomacy also need to address water governance at sub-state levels. As a political, multi-level, and normative field, peace and conflict research offers a pluralism of approaches designed to bring actors together at all levels. Drawing upon this research, this paper offers new focal points for water diplomacy that can enhance its policy effectiveness and enrich its underlying academic current. More specifically, it presents three hitherto undervalued tools for water diplomacy: at the interstate level, to uncover the rich body of political norms that bind states to shared understandings of acceptable practice around water. At the intrastate level, to incorporate ethnography of water users and civil society groups' responses to state-led waterworks projects, and at the communal level to employ disaggregated georeferenced data on water resources in conflict-prone areas. Taken together, these analytical tools provide a multi-faceted political gauge of the dynamics of water diplomacy, and add vital impetus to develop water diplomacy across multiple levels of policy engagement.

  18. Radium-226 levels in Italian drinking waters and foods

    International Nuclear Information System (INIS)

    Mastinu, G.G.; Santaroni, G.P.

    1980-01-01

    Levels of 226 Ra in Italian waters and foods were measured. Results were similar to those found in other countries, except for some mineral waters with 226 Ra concentrations above 1 pCi/liter andup to 19 pCi/liter. No difinite correlation was found between the 226 Ra concentrations measured and the high natural background radiation levels determined in central Italy in previous work

  19. Separating decadal global water cycle variability from sea level rise.

    Science.gov (United States)

    Hamlington, B D; Reager, J T; Lo, M-H; Karnauskas, K B; Leben, R R

    2017-04-20

    Under a warming climate, amplification of the water cycle and changes in precipitation patterns over land are expected to occur, subsequently impacting the terrestrial water balance. On global scales, such changes in terrestrial water storage (TWS) will be reflected in the water contained in the ocean and can manifest as global sea level variations. Naturally occurring climate-driven TWS variability can temporarily obscure the long-term trend in sea level rise, in addition to modulating the impacts of sea level rise through natural periodic undulation in regional and global sea level. The internal variability of the global water cycle, therefore, confounds both the detection and attribution of sea level rise. Here, we use a suite of observations to quantify and map the contribution of TWS variability to sea level variability on decadal timescales. In particular, we find that decadal sea level variability centered in the Pacific Ocean is closely tied to low frequency variability of TWS in key areas across the globe. The unambiguous identification and clean separation of this component of variability is the missing step in uncovering the anthropogenic trend in sea level and understanding the potential for low-frequency modulation of future TWS impacts including flooding and drought.

  20. Determination of Heavy Metal Levels in Various Industrial Waste Waters

    Directory of Open Access Journals (Sweden)

    Mustafa Şahin Dündar

    2012-06-01

    Full Text Available Important part of the environmetal pollution consists of waste water and water pollution. The water polluted by anthropogenical, industrial, and agricultural originated sources are defined as waste waters which are the main pollution sources for reservoirs, rivers, lakes, and seas. In this work, waste waters of leather, textile, automotive side, and metal plating industries were used to determine the levels of Cu, Zn, Cr, Pb and Ni by using Flame Atomic Absorption Spectrometer. As a result, highest mean levels of copper in supernatants of plating and textile industries were observed as 377,18 ng ml-1, respectively 103 ng ml-1 lead and 963,6 ng ml-1 nickel in plating industry, 1068,2 ng ml-1 zinc and 14557,1 ng ml-1 chromium in plating and leather industries were determined.

  1. Water resources data for Virginia, water year 1991. Volume 2. Ground-water-level and ground-water-quality records. Water-data report (Annual), 1 October 1991-30 September 1992

    International Nuclear Information System (INIS)

    Prugh, B.J.; Powell, E.D.

    1993-01-01

    Water-resources data for the 1992 water year for Virginia consist of records of water levels and water quality of ground-water wells. The report (Volume 2. Ground-Water-Level and Ground-Water-Quality Records) contains water levels at 356 observation wells and water quality at 2 wells. Locations of these wells are given in the report

  2. Water levels of the Ozark aquifer in northern Arkansas, 2013

    Science.gov (United States)

    Schrader, Tony P.

    2015-07-13

    The Ozark aquifer is the largest aquifer, both in area of outcrop and thickness, and the most important source of freshwater in the Ozark Plateaus physiographic province, supplying water to northern Arkansas, southeastern Kansas, southern Missouri, and northeastern Oklahoma. The study area includes 16 Arkansas counties lying completely or partially within the Ozark Plateaus of the Interior Highlands major physiographic division. The U.S. Geological Survey, in cooperation with the Arkansas Natural Resources Commission and the Arkansas Geological Survey, conducted a study of water levels in the Ozark aquifer within Arkansas. This report presents a potentiometric-surface map of the Ozark aquifer within the Ozark Plateaus of northern Arkansas, representing water-level conditions for the early spring of 2013 and selected water-level hydrographs.

  3. Levels of major and trace elements, including rare earth elements, and ²³⁸U in Croatian tap waters.

    Science.gov (United States)

    Fiket, Željka; Rožmarić, Martina; Krmpotić, Matea; Benedik, Ljudmila

    2015-05-01

    Concentrations of 46 elements, including major, trace, and rare earth elements, and (238)U in Croatian tap waters were investigated. Selected sampling locations include tap waters from various hydrogeological regions, i.e., different types of aquifers, providing insight into the range of concentrations of studied elements and (238)U activity concentrations in Croatian tap waters. Obtained concentrations were compared with the Croatian maximum contaminant levels for trace elements in water intended for human consumption, as well as WHO and EPA drinking water standards. Concentrations in all analyzed tap waters were found in accordance with Croatian regulations, except tap water from Šibenik in which manganese in concentration above maximum permissible concentration (MPC) was measured. Furthermore, in tap water from Osijek, levels of arsenic exceeded the WHO guidelines and EPA regulations. In general, investigated tap waters were found to vary considerably in concentrations of studied elements, including (238)U activity concentrations. Causes of variability were further explored using statistical methods. Composition of studied tap waters was found to be predominately influenced by hydrogeological characteristics of the aquifer, at regional and local level, the existing redox conditions, and the household plumbing system. Rare earth element data, including abundances and fractionation patterns, complemented the characterization and facilitated the interpretation of factors affecting the composition of the analyzed tap waters.

  4. Radar Based Flow and Water Level Forecasting in Sewer Systems

    DEFF Research Database (Denmark)

    Thorndahl, Søren; Rasmussen, Michael R.; Grum, M.

    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. Bot...

  5. Water quality characteristics and pollution levels of heavy metals in ...

    African Journals Online (AJOL)

    The main aim of this study was to assess the level of water quality of Lake Haiq, Ethiopia with respect to selected physical ... gated using standard analytical procedures. the level of the studied heavy metals (Pb, Cd, Cu and Zn) was determined using the .... no known discharge and hence used as reference site. Sampling ...

  6. Estimation Of Height Of Oil -Water Contact Above Free Water Level ...

    African Journals Online (AJOL)

    An estimate of oil-water contact (OWC) and the understanding of the capillary behaviour of hydrocarbon reservoirs are vital for optimum reservoir characterization, hydrocarbon exploration and production. Hence, the height of oil-water contact above free water level for different rock types from some Niger Delta reservoirs ...

  7. Cosine components in water levels at Yucca Mountain

    International Nuclear Information System (INIS)

    Rice, J.; Lehman, L.; Keen, K.

    1990-01-01

    Water-level records from wells at Yucca Mountain, Nevada are analyzed periodically to determine if they contain periodic (cosine) components. Water-level data from selected wells are input to an iterative numerical procedure that determines a best fitting cosine function. The available water-level data, with coverage of up to 5 years, appear to be representative of the natural water-level changes. From our analysis of 9 water-level records, it appears that there may be periodic components (periods of 2-3 years) in the groundwater-level fluctuations at Yucca Mountain, Nevada, although some records are fit better than others by cosine functions. It also appears that the periodic behavior has a spatial distribution. Wells west of Yucca Mountain have different periods and phase shifts from wells on and east of Yucca Mountain. Interestingly, a similar spatial distribution of groundwater chemistry at Yucca Mountain is reported by Matuska (1988). This suggests a physical cause may underlie the different physical and chemical groundwater conditions. Although a variety of natural processes could cause water-level fluctuations, hydrologic processes are the most likely, because the periodicities are only a few years. A possible cause could be periodic recharge related to a periodicity in precipitation. It is interesting that Cochran et al., (1988), show a crude two-year cycle of precipitation for 1961 to 1970 in southern Nevada. Why periods and phase shifts may differ across Yucca Mountain is unknown. Different phase shifts could indicate different lag times of response to hydrologic stimuli. Difference in periods could mean that the geologic media is heterogeneous and displays heterogeneous response to a single stimulus, or that stimuli differ in certain regions, or that a hydraulic barrier separates the groundwater system into two regions having different water chemistry and recharge areas. 13 refs., 5 figs., 1 tab

  8. A bottom-up approach to identifying the maximum operational adaptive capacity of water resource systems to a changing climate

    Science.gov (United States)

    Culley, S.; Noble, S.; Yates, A.; Timbs, M.; Westra, S.; Maier, H. R.; Giuliani, M.; Castelletti, A.

    2016-09-01

    Many water resource systems have been designed assuming that the statistical characteristics of future inflows are similar to those of the historical record. This assumption is no longer valid due to large-scale changes in the global climate, potentially causing declines in water resource system performance, or even complete system failure. Upgrading system infrastructure to cope with climate change can require substantial financial outlay, so it might be preferable to optimize existing system performance when possible. This paper builds on decision scaling theory by proposing a bottom-up approach to designing optimal feedback control policies for a water system exposed to a changing climate. This approach not only describes optimal operational policies for a range of potential climatic changes but also enables an assessment of a system's upper limit of its operational adaptive capacity, beyond which upgrades to infrastructure become unavoidable. The approach is illustrated using the Lake Como system in Northern Italy—a regulated system with a complex relationship between climate and system performance. By optimizing system operation under different hydrometeorological states, it is shown that the system can continue to meet its minimum performance requirements for more than three times as many states as it can under current operations. Importantly, a single management policy, no matter how robust, cannot fully utilize existing infrastructure as effectively as an ensemble of flexible management policies that are updated as the climate changes.

  9. A new approach to hierarchical data analysis: Targeted maximum likelihood estimation for the causal effect of a cluster-level exposure.

    Science.gov (United States)

    Balzer, Laura B; Zheng, Wenjing; van der Laan, Mark J; Petersen, Maya L

    2018-01-01

    We often seek to estimate the impact of an exposure naturally occurring or randomly assigned at the cluster-level. For example, the literature on neighborhood determinants of health continues to grow. Likewise, community randomized trials are applied to learn about real-world implementation, sustainability, and population effects of interventions with proven individual-level efficacy. In these settings, individual-level outcomes are correlated due to shared cluster-level factors, including the exposure, as well as social or biological interactions between individuals. To flexibly and efficiently estimate the effect of a cluster-level exposure, we present two targeted maximum likelihood estimators (TMLEs). The first TMLE is developed under a non-parametric causal model, which allows for arbitrary interactions between individuals within a cluster. These interactions include direct transmission of the outcome (i.e. contagion) and influence of one individual's covariates on another's outcome (i.e. covariate interference). The second TMLE is developed under a causal sub-model assuming the cluster-level and individual-specific covariates are sufficient to control for confounding. Simulations compare the alternative estimators and illustrate the potential gains from pairing individual-level risk factors and outcomes during estimation, while avoiding unwarranted assumptions. Our results suggest that estimation under the sub-model can result in bias and misleading inference in an observational setting. Incorporating working assumptions during estimation is more robust than assuming they hold in the underlying causal model. We illustrate our approach with an application to HIV prevention and treatment.

  10. Intermediate and deep water mass distribution in the Pacific during the Last Glacial Maximum inferred from oxygen and carbon stable isotopes

    Science.gov (United States)

    Herguera, J. C.; Herbert, T.; Kashgarian, M.; Charles, C.

    2010-05-01

    Intermediate ocean circulation changes during the last Glacial Maximum (LGM) in the North Pacific have been linked with Northern Hemisphere climate through air-sea interactions, although the extent and the source of the variability of the processes forcing these changes are still not well resolved. The ventilated volumes and ages in the upper wind driven layer are related to the wind stress curl and surface buoyancy fluxes at mid to high latitudes in the North Pacific. In contrast, the deeper thermohaline layers are more effectively ventilated by direct atmosphere-sea exchange during convective formation of Subantarctic Mode Waters (SAMW) and Antarctic Intermediate Waters (AAIW) in the Southern Ocean, the precursors of Pacific Intermediate Waters (PIW) in the North Pacific. Results reported here show a fundamental change in the carbon isotopic gradient between intermediate and deep waters during the LGM in the eastern North Pacific indicating a deepening of nutrient and carbon rich waters. These observations suggest changes in the source and nature of intermediate waters of Southern Ocean origin that feed PIW and enhanced ventilation processes in the North Pacific, further affecting paleoproductivity and export patters in this basin. Furthermore, oxygen isotopic results indicate these changes may have been accomplished in part by changes in circulation affecting the intermediate depths during the LGM.

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

    International Nuclear Information System (INIS)

    Jones, T.L.; Gee, G.W.; Kirkham, R.R.; Gibson, D.D.

    1982-08-01

    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

  12. Fluorine level in some city water supplies of Bangladesh

    International Nuclear Information System (INIS)

    Hoque, A.K.M.F.; Abedin, M.J.; Rahman, M.M.; Mia, M. Y.; Tarafder, M.S.A.; Khaliquzzaman, M.; Hossain, M.D.; Khan, A.H.

    2003-01-01

    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

  13. Water Security at Local Government Level: What do People Think?

    CSIR Research Space (South Africa)

    Meissner, Richard

    2016-06-01

    Full Text Available stream_source_info Meissner_2016.pdf.txt stream_content_type text/plain stream_size 2853 Content-Encoding UTF-8 stream_name Meissner_2016.pdf.txt Content-Type text/plain; charset=UTF-8 Water Security at Local... Government Level: What do People Think? By Dr. Richard Meissner Integrated Water Assessment Group Natural Resources and the Environment Council for Scientific and Industrial Research Presented at the Sustainable Water Seminar 2016, CSIR ICC, 2...

  14. The Swr 1000: a nuclear power plant concept with boiling water reactor for maximum safety and economy of operation

    International Nuclear Information System (INIS)

    Brettschuh, W.

    2001-01-01

    The SWR 1000 is a design concept for a light water reactor nuclear power plant that meets all requirements regarding plant safety, economic efficiency and environ-mental friendliness. As a result of the plant's safety concept, the occurrence of core damage can, for all practical intents and purposes, be ruled out. If a core melt accident should nevertheless occur, the molten core can be retained inside the RPV, thus ensuring that all consequences of such an accident remain restricted to the plant itself. The power generating costs of the SWR 1000 are lower than with those of coal-fired and combined-cycle power plants. Power generation using nuclear energy does not release carbon dioxide to the environment, thus meeting the need for sustainable protection of our global climate. (author)

  15. Ground-water development and the effects on ground-water levels and water quality in the town of Atherton, San Mateo County, California

    Science.gov (United States)

    Metzger, Loren F.; Fio, John L.

    1997-01-01

    measured hydraulic heads in the study area from April 1993 through September 1995 were above sea level indicates that saltwater intrusion was unlikely during this period. The chemistry of 20 well-water samples is characterized as a calcium magnesium carbonate bicarbonate type water. There is no evidence of saltwater intrusion from San Francisco Bay; how ever, water samples from wells nearest the bay and bedrock assemblages indicate a greater concentra tion of dissolved constituents and salinity. Dissolved-solids concentrations of water samples from wells in these areas exceeded 1,000 milli grams per liter, and several samples contained a substantial fraction of sodium and chloride. Water hardness for the 20 wells sampled averaged 471 milligrams per liter as calcium carbonate, which is classified as very hard. One well sample exceeded the primary maximum contaminant level for drinking water in nitrate, several wells exceeded the secondary maximum contaminant level for chloride and sulfate, and all wells sampled exceeded the secondary maximum contaminant level for total dissolved solids. Land-subsidence and the resultant damage because of excessive ground-water pumping, in combination with periodic drought, have a well- documented history in the south San Francisco Bay area. Land-elevation surveying data from 1934 to 1967 indicate that subsidence ranged from 0.1 to approximately 0.5 foot in the vicinity of the study area. It could not be determined from land- surface elevation surveying data from 1993 whether subsidence is currently occurring in the study area.

  16. Maximum Plant Uptakes for Water, Nutrients, and Oxygen Are Not Always Met by Irrigation Rate and Distribution in Water-based Cultivation Systems

    NARCIS (Netherlands)

    Blok, Chris; Jackson, Brian E.; Guo, Xianfeng; Visser, De Pieter H.B.; Marcelis, Leo F.M.

    2017-01-01

    Growing on rooting media other than soils in situ -i.e., substrate-based growing- allows for higher yields than soil-based growing as transport rates of water, nutrients, and oxygen in substrate surpass those in soil. Possibly water-based growing allows for even higher yields as transport rates of

  17. Assessment of the Water Levels and Currents at the Mississippi Bight During Hurricane Katrina.

    Science.gov (United States)

    Nwankwo, U. C.; Howden, S. D.; Dodd, D.; Wells, D. E.

    2017-12-01

    In an effort to extend the length of GPS baselines further offshore, the Hydrographic Science Research Center at the University of Southern Mississippi deployed a buoy which had a survey grade GPS receiver, an ADPC and a motion sensor unit in the Mississippi Bight in late 2004. The GPS data were initially processed using the Post Processed Kinematic technique with data from a nearby GPS base station on Horn Island. This processing technique discontinued when the storm (Hurricane Katrina) destroyed the base station in late August of 2005. However, since then a stand-alone positioning technique termed Precise Point Positioning (PPP) matured and allowed for the reprocessing of the buoy GPS data throughout Katrina. The processed GPS data were corrected for buoy angular motions using Tait Bryan transformation model. Tidal datums (Epoch 1983-2001) were transferred from the National Oceanic and Atmospheric Administration (NOAA) National Water Level at Waveland, Mississippi (Station ID 8747766) to the buoy using the Modified Range Ratio method. The maximum water level during the storm was found to be about 3.578m, relative to the transferred Mean Sea Level datum. The storm surge built over more than 24 hours, but fell back to normal levels in less than 3 hours. The maximum speed of the current with respect to the seafloor was recorded to be about 4knots towards the southeast as the storm surge moved back offshore.

  18. Contamination level in vegetables grown around Peshawar using sewerage and canal water

    International Nuclear Information System (INIS)

    Mahmood, S.

    2001-01-01

    The level of contamination in vegetables grown around Peshawar using sewerage/canal water is reported. The vegetable samples were collected from three representative locations. The results indicated that vegetables grown with sewerage water contained higher levels of Cd, Cu and Pb than those with irrigation water. Maximum amount of Cd was in Qulfa (3.68 mu g/ g) followed by sponge gourd leaves (3.38 mu g/ g) the tomato leaves (93.32 mu g/ g). while Pb in tomato leaves (4.88 mu g / g), Cu content ranged between 2.08 and 7.5 mu g/g in these vegetables. In the vegetables grown with canal water the Cd ranged 0.82 - 2.88 mu g/g, Cu 2.38 mu g /g and Pb 0.84 - 1.88 mu g/ g. The concentration of Fe and P in the vegetables of sewerage water ranged 9.0-25.0 and 5.6-14.8 mg/100g respectively while those grown with canal water 9.0-11.0 mg/ 100 g and 8.4-12.8 mg/ 100 g respectively. (author)

  19. Levels of trace elements in MWSS drinking water

    International Nuclear Information System (INIS)

    Andal, T.T.

    1998-01-01

    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)

  20. TRIHALOMETHANE LEVELS IN HOME TAP WATER AND SEMEN QUALITY

    Science.gov (United States)

    Trihalomethane Levels in Home Tap Water and Semen QualityLaura Fenster, 1 Kirsten Waller, 2 Gayle Windham, 1 Tanya Henneman, 2 Meredith Anderson, 2 Pauline Mendola, 3 James W. Overstreet, 4 Shanna H. Swan51California Department of Health Services, Division of Environm...

  1. Water-Level Analysis for Cumberland Sound, Georgia

    National Research Council Canada - National Science Library

    Kraus, Nicholas

    1997-01-01

    .... The channel through St Marys Entrance is maintained at a 50-ft depth through significant dredging that occurred from 1986-1988 Questions arose as to whether this dredging had raised the water level in Cumberland Sound. The U.S...

  2. Lake St. Clair: Storm Wave and Water Level Modeling

    Science.gov (United States)

    2013-06-01

    R. A. Luettich, C. Dawson, V. J. Cardone , A. T. Cox, M. D. Powell, H. J. Westerink, and H. J. Roberts. 2010. A high resolution coupled riverine flow...Storm Wave and Water Level Modeling 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Tyler J. Hesser

  3. design and implementation of a water level controller

    African Journals Online (AJOL)

    2012-03-01

    Mar 1, 2012 ... Nigerian Journal of Technology (NIJOTECH) ... in real time application by using it to control the level of water in a tank fed by a ... chine when a cow is finished in a milking par- .... Robotics Arm. IEEE Control Systems 10(1).

  4. Effect of electrolyzed reduced water on malondialdehyde levels and ...

    African Journals Online (AJOL)

    Purpose: To evaluate the effects of electrolyzed reduced water (ERW) on malondialdehyde (MDA) levels and neutrophil cells in Wistar rats suffering from aggressive periodontitis. Methods: Wistar rats (Rattus norvegicus) were infected with A. actinomycetemcomitans before being divided into a control group and a treatment ...

  5. High-level water purifying technology. Kodo josui shori gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Tsugura, H; Tsukiashi, K [Meidensha Corp., Tokyo (Japan)

    1993-07-01

    Research and development have been carried out on a high-level water purifying system using ozone and activated charcoals to supply drinking water free of carcinogenic matters and odors. This system comprises a system to utilize ozone by using silent discharge and oxygen enriching device, and a living organism/activated charcoal treatment system. The latter system utilizes living organisms deposited on activated charcoal surfaces to remove polluting substances including ammonia. The treatment experimenting equipment comprises an ozone generating system, an ozone treating column, an activated charcoal treating column, an ozone/activated charcoal control device, and a water amount and quality measuring system. An experiment was carried out using an experimental plant with a capacity of 20 m[sup 3]/day on water taken from the sedimentation process at an actual water purifying plant. As a result, trihalomethane formation potential was removed at about 40% in the ozone treatment, and at 70% in the whole treatment combining the ozone and living organism/activated charcoal treatments. For parameterization of palatability of water, a method is being studied that utilizes nuclear magnetic resonance to investigate degrees of water cluster. The method is regarded promising. 1 ref., 4 figs.

  6. Seasonal variations in the level of heavy metals in the water of minor rivers

    Directory of Open Access Journals (Sweden)

    I. L. Sukhodolska

    2017-01-01

    Full Text Available This article analyses the level of heavy metals (Zn, Mn, Fe, Pb, Co, Ni, Cd and characteristics of their transportation through the water of minor rivers in Rivne region, Ukraine. The levels of Zn, Cu, Mn, Fe, Ni, Co in the waters of these fisheries exceeded the maximum permissible concentration limit in different months. We found that the concentration of Pb and Cd did not exceed the permissible concentration limit in the waters of the fisheries during the year of research, while the level of other metals exceeded the permissible levels by 1.1 to 151.0 times. This research confirms that the surface waters of Rivne region are characterized by high concentrations of iron, manganese, zinc, and nickel. The level of iron exceeded the maximum permissible concentration limit by 1.1 to 5.0 times, the level of zinc by 1.5 to 15.0 times, that of manganese by1.3 to 6.7 times and the nickel level by 1.3 to 151.0 times in the fishery waters. In principle, the increase in the level of heavy metals (Zn, Cu, Mn, Fe, Ni, Co is connected with the lithological composition of reservoirs in the water-collecting areas of the investigated rivers, and besides with the significant influence of the anthropogenic load (fuel combustion, aqueous wastes of factory units, agricultural effluent, etc., and with the increase in aquatic vegetation, pH balance, temperature change and so on. The appearance of iron-manganese compounds can be explained by natural causes such as reformation of the source minerals into secondary minerals in the conditions of pH level recession in water, which causes the release of these molecular entities; leaching of iron from the iron-manganese septarian nodules, a substantial amount of which is contained in the illuvial horizon. The increase in the level of zinc and nickel in the river water is connected with the leaching of these elements from subsurface rocks, soil and forest leaf litter. Atmospheric condensation is a significant source of the

  7. 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.

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

    NARCIS (Netherlands)

    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

  9. Last Glacial Maximum to Holocene climate evolution controlled by sea-level change, Leeuwin Current, and Australian Monsoon in the Northwestern Australia

    Science.gov (United States)

    Ishiwa, T.; Yokoyama, Y.; McHugh, C.; Reuning, L.; Gallagher, S. J.

    2017-12-01

    The transition from cold to warm conditions during the last deglaciation influenced climate variability in the Indian Ocean and Pacific as a result of submerge of continental shelf and variations in the Indonesian Throughflow and Australian Monsoon. The shallow continental shelf (Program Expedition 356 Indonesian Throughflow drilled in the northwestern Australian shallow continental shelf and recovered an interval from the Last Glacial Maximum to Holocene in Site U1461. Radiocarbon dating on macrofossils, foraminifera, and bulk organic matter provided a precise age-depth model, leading to high-resolved paleoclimate reconstruction. X-ray elemental analysis results are interpreted as an indicator of sedimentary environmental changes. The upper 20-m part of Site U1461 apparently records the climate transition from the LGM to Holocene in the northwestern Australia, which could be associated with sea-level change, Leeuwin Current activity, and the Australian Monsoon.

  10. An analysis of the water-level monitoring system for a boiling-water reactor

    International Nuclear Information System (INIS)

    Carlson, R.W.; Belblidia, L.A.; Russell, J.L. Jr.

    1985-01-01

    The water-level instrumentation system is very important to the overall safety of a BWR. This system is being monitored by the Safety Parameter Display System (SPDS) that is being installed in Georgia Power Company's Plant Hatch. One of the most significant functions of the SPDS is the comparison of redundant instrument readings and formation of the best estimate of each parameter from those readings which are consistent. When comparing water-level instrument readings, it is necessary to correct the individual readings for differences between current and calibration conditions as well as for differences between calibration conditions for the multiple instruments. This paper documents the examination of the water-level instrumentation system at Plant Hatch and presents the development of the equations that were used to determine the differences between indicated and actual water levels. (author)

  11. Hydraulics and drones: observations of water level, bathymetry and water surface velocity from Unmanned Aerial Vehicles

    DEFF Research Database (Denmark)

    Bandini, Filippo

    -navigable rivers and overpass obstacles (e.g. river structures). Computer vision, autopilot system and beyond visual line-of-sight (BVLOS) flights will ensure the possibility to retrieve hyper-spatial observations of water depth, without requiring the operator to access the area. Surface water speed can......The planet faces several water-related threats, including water scarcity, floods, and pollution. Satellite and airborne sensing technology is rapidly evolving to improve the observation and prediction of surface water and thus prevent natural disasters. While technological developments require....... Although UAV-borne measurements of surface water speed have already been documented in the literature, a novel approach was developed to avoid GCPs. This research is the first demonstration that orthometric water level can be measured from UAVs with a radar system and a GNSS (Global Navigation Satellite...

  12. Intercomparison of low-level tritium in water

    International Nuclear Information System (INIS)

    Sipka, V.; Zupancic, M.; Hadzisehovic, M.; Bacic, S.; Vukovic, Z.

    1989-01-01

    In 1985 the Section of Isotope Hydrology of the IAEA organized the fourth intercomparison for low-level tritium counting in waters. Four water samples with different 3 H concentration were sent to 85 laboratories willing to participate. The results from the different laboratories were presented in the unified questionnaires and coded. The participation in the intercomparisons for every laboratory doing low-level 3 H measurements in the waters is very important and useful. This is a best way to check the entire procedure and methods of the measurements and the reliability of the standards used. Since our laboratories are doing the natural 3 H concentration measurement in the waters for the environmental control and hydrology reasons it was necessary to take part in this intercomparison. Our standard procedure was applied. The 3 H activity in the samples was measured by liquid scintillation counting after an electrolytic enrichment. The results of our measurements of the four water samples, received from the organizers, are presented on the figures and tables presenting summary of the intercomparison. It is clear that our measurement (procedure and standards) have given satisfactory results (author)

  13. Emission of Carbon Dioxide Influenced by Different Water Levels from Soil Incubated Organic Residues

    Science.gov (United States)

    Hossain, M. B.; Puteh, A. B.

    2013-01-01

    We studied the influence of different organic residues and water levels on decomposition rate and carbon sequestration in soil. Organic residues (rice straw, rice root, cow dung, and poultry litter) including control were tested under moistened and flooding systems. An experiment was laid out as a complete randomized design at 25°C for 120 days. Higher CO2-C (265.45 mg) emission was observed in moistened condition than in flooding condition from 7 to 120 days. Among the organic residues, poultry litter produced the highest CO2-C emission. Poultry litter with soil mixture increased 121% cumulative CO2-C compared to control. On average, about 38% of added poultry litter C was mineralized to CO2-C. Maximum CO2-C was found in 7 days after incubation and thereafter CO2-C emission was decreased with the increase of time. Control produced the lowest CO2-C (158.23 mg). Poultry litter produced maximum cumulative CO2-C (349.91 mg). Maximum organic carbon was obtained in cow dung which followed by other organic residues. Organic residues along with flooding condition decreased cumulative CO2-C, k value and increased organic C in soil. Maximum k value was found in poultry litter and control. Incorpored rice straw increased organic carbon and decreased k value (0.003 g d−1) in soil. In conclusion, rice straw and poultry litter were suitable for improving soil carbon. PMID:24163626

  14. Groundwater levels and water quality during a 96-hour aquifer test in Pickaway County, Ohio, 2012

    Science.gov (United States)

    Haefner, Ralph J.; Runkle, Donna L.; Mailot, Brian E.

    2014-01-01

    During October–November 2012, a 96-hour aquifer test was performed at a proposed well field in northern Pickaway County, Ohio, to investigate groundwater with elevated nitrate concentrations. Earlier sampling done by the City of Columbus revealed that some wells had concentrations of nitrate that approached 10 milligrams per liter (mg/L), whereas other wells and the nearby Scioto River had concentrations from 2 to 6 mg/L. The purpose of the current test was to examine potential changes in water quality that may be expected if the site was developed into a public water-supply source; therefore, water-transmitting properties determined during a previous test were not determined a second time. Before and during the test, water-level data and water-quality samples were obtained from observation wells while a test production well was pumped at 1,300 gallons per minute. Before the test, local groundwater levels indicated that groundwater was being discharged to the nearby Scioto River, but during the test, the stream was losing streamflow owing to infiltration. Water levels declined in the pumping well, in adjacent observation wells, and in a nearby streambed piezometer as pumping commenced. The maximum drawdown in the pumping well was 29.75 feet, measured about 95 hours after pumping began. Water-quality data, including analyses for field parameters, major and trace elements, nutrients, and stable isotopes of oxygen and nitrogen in nitrate, demonstrated only small variations before and during the test. Concentrations of nitrate in five samples from the pumping well ranged from about 5.10 to 5.42 mg/L before and during the test, whereas concentrations of nitrate in five samples on or about the same sampling dates and times at a monitoring site on the Scioto River adjacent to the pumping well ranged from 3.46 to 4.97 mg/L. Water from two nearby observation wells had nitrate concentrations approaching 10 mg/L, which is the U.S. Environmental Protection Agency’s Maximum

  15. Coupling of sea level and tidal range changes, with implications for future water levels.

    Science.gov (United States)

    Devlin, Adam T; Jay, David A; Talke, Stefan A; Zaron, Edward D; Pan, Jiayi; Lin, Hui

    2017-12-05

    Are perturbations to ocean tides correlated with changing sea-level and climate, and how will this affect high water levels? Here, we survey 152 tide gauges in the Pacific Ocean and South China Sea and statistically evaluate how the sum of the four largest tidal constituents, a proxy for the highest astronomical tide (HAT), changes over seasonal and interannual time scales. We find that the variability in HAT is significantly correlated with sea-level variability; approximately 35% of stations exhibit a greater than ±50 mm tidal change per meter sea-level fluctuation. Focusing on a subset of three stations with long records, probability density function (PDF) analyses of the 95% percentile exceedance of total sea level (TSL) show long-term changes of this high-water metric. At Hong Kong, the increase in tides significantly amplifies the risk caused by sea-level rise. Regions of tidal decrease and/or amplification highlight the non-linear response to sea-level variations, with the potential to amplify or mitigate against the increased flood risk caused by sea-level rise. Overall, our analysis suggests that in many regions, local flood level determinations should consider the joint effects of non-stationary tides and mean sea level (MSL) at multiple time scales.

  16. Economic sustainability, water security and multi-level governance of local water schemes in Nepal

    Directory of Open Access Journals (Sweden)

    Emma Hakala

    2017-07-01

    Full Text Available This article explores the role of multi-level governance and power structures in local water security through a case study of the Nawalparasi district in Nepal. It focuses on economic sustainability as a measure to address water security, placing this thematic in the context of a complicated power structure consisting of local, district and national administration as well as external development cooperation actors. The study aims to find out whether efforts to improve the economic sustainability of water schemes have contributed to water security at the local level. In addition, it will consider the interactions between water security, power structures and local equality and justice. The research builds upon survey data from the Nepalese districts of Nawalparasi and Palpa, and a case study based on interviews and observation in Nawalparasi. The survey was performed in water schemes built within a Finnish development cooperation programme spanning from 1990 to 2004, allowing a consideration of the long-term sustainability of water management projects. This adds a crucial external influence into the intra-state power structures shaping water management in Nepal. The article thus provides an alternative perspective to cross-regional water security through a discussion combining transnational involvement with national and local points of view.

  17. Measurements of radon concentration levels in drinking water at urban area of Curitiba, Brazil

    International Nuclear Information System (INIS)

    Correa, Janine Nicolosi; Paschuk, Sergei A.; Schelin, Hugo R.; Barbosa, Laercio; Sadula, Tatyana; Matsuzaki, Cristiana A.

    2009-01-01

    Current work presents the results of more than 100 measurements of 222 Rn activity in drinking water collected at artesian bores at Curitiba region during the period of 2008 - 2009. The measurements were performed at the Laboratory of Applied Nuclear Physics of the Federal University of Technology in cooperation with the Nuclear Technology Development Center (CDTN) of Brazilian Nuclear Energy Committee (CNEN). Experimental setup was based on the Professional Radon Monitor (ALPHA GUARD) connected to specific kit of glass vessels Aqua KIT through the air pump. The equipment was adjusted with air flow of 0.5 L/min. The 222 Rn concentration levels were detected and analyzed by the computer every 10 minutes using the software DataEXPERT by GENITRON Instruments. Collected average levels of 222 Rn concentration were processed taking into account the volume of water sample and its temperature, atmospheric pressure and the total volume of the air in the vessels. Collected samples of water presented the average 222 Rn activity about 57.70 Bq/L which is almost 5 times more than maximum level of 11.1 Bq/L recommended by the USEPA (United States Environmental Protection Agency). It has to be noted that many artesian drillings presented the radon activity in the range of 100 - 200 Bq/L. Further measurements are planned to be performed at other regions of Parana State and will involve the mineral water sources, explored artesian drillings as well as soil samples. (author)''

  18. Tuning Fermi level of Cr{sub 2}CoZ (Z=Al and Si) inverse Heusler alloys via Fe-doping for maximum spin polarization

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mukhtiyar [Department of Physics, Kurukshetra University, Kurukshetra-136119, Haryana (India); Saini, Hardev S. [Department of Physics, Panjab University, Chandigarh-160014 (India); Thakur, Jyoti [Department of Physics, Kurukshetra University, Kurukshetra-136119, Haryana (India); Reshak, Ali H. [New Technologies—Research Center, University of West Bohemia, Univerzitni 8, 306 14 Pilsen (Czech Republic); Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis (Malaysia); Kashyap, Manish K., E-mail: manishdft@gmail.com [Department of Physics, Kurukshetra University, Kurukshetra-136119, Haryana (India)

    2014-12-15

    We report full potential treatment of electronic and magnetic properties of Cr{sub 2−x}Fe{sub x}CoZ (Z=Al, Si) Heusler alloys where x=0.0, 0.25, 0.5, 0.75 and 1.0, based on density functional theory (DFT). Both parent alloys (Cr{sub 2}CoAl and Cr{sub 2}CoSi) are not half-metallic frromagnets. The gradual replacement of one Cr sublattice with Fe induces the half-metallicity in these systems, resulting maximum spin polarization. The half-metallicity starts to appear in Cr{sub 2−x}Fe{sub x}CoAl and Cr{sub 2−x}Fe{sub x}CoSi with x=0.50 and x=0.25, respectively, and the values of minority-spin gap and half-metallic gap or spin-flip gap increase with further increase of x. These gaps are found to be maximum for x=1.0 for both cases. An excellent agreement between the structural properties of CoFeCrAl with available experimental study is obtained. The Fermi level tuning by Fe-doping makes these alloys highly spin polarized and thus these can be used as promising candidates for spin valves and magnetic tunnelling junction applications. - Highlights: • Tuning of E{sub F} in Cr{sub 2}CoZ (Z=Al, Si) has been demonstrated via Fe doping. • Effect of Fe doping on half-metallicity and magnetism have been discussed. • The new alloys have a potential of being used as spin polarized electrodes.

  19. Aquaponic Growbed Water Level Control Using Fog Architecture

    Science.gov (United States)

    Asmi Romli, Muhamad; Daud, Shuhaizar; Raof, Rafikha Aliana A.; Awang Ahmad, Zahari; Mahrom, Norfadilla

    2018-05-01

    Integrated Multi-Trophic Aquaculture (IMTA) is an advance method of aquaculture which combines species with different nutritional needs to live together. The combination between aquatic live and crops is called aquaponics. Aquatic waste that normally removed by biofilters in normal aquaculture practice will be absorbed by crops in this practice. Aquaponics have few common components and growbed provide the best filtration function. In growbed a siphon act as mechanical structure to control water fill and flush process. Water to the growbed comes from fish tank with multiple flow speeds based on the pump specification and height. Too low speed and too fast flow rate can result in siphon malfunctionality. Pumps with variable speed do exist but it is costly. Majority of the aquaponic practitioner use single speed pump and try to match the pump speed with siphon operational requirement. In order to remove the matching requirement some control need to be introduced. Preliminarily this research will show the concept of fill-and-flush for multiple pumping speeds. The final aim of this paper is to show how water level management can be done to remove the speed dependency. The siphon tried to be controlled remotely since wireless data transmission quite practical in vast operational area. Fog architecture will be used in order to transmit sensor data and control command. This paper able to show the water able to be retented in the growbed within suggested duration by stopping the flow in once predefined level.

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

    International Nuclear Information System (INIS)

    Gao Peng; Zhang Qinshun

    2006-01-01

    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)

  1. Responses of Water and Salt Parameters to Groundwater Levels for Soil Columns Planted with Tamarix chinensis.

    Science.gov (United States)

    Xia, Jiangbao; Zhao, Ximei; Chen, Yinping; Fang, Ying; Zhao, Ziguo

    2016-01-01

    Groundwater is the main water resource for plant growth and development in the saline soil of the Yellow River Delta in China. To investigate the variabilities and distributions of soil water and salt contents at various groundwater level (GL), soil columns with planting Tamarix chinensis Lour were established at six different GL. The results demonstrated the following: With increasing GL, the relative soil water content (RWC) declined significantly, whereas the salt content (SC) and absolute soil solution concentration (CS) decreased after the initial increase in the different soil profiles. A GL of 1.2 m was the turning point for variations in the soil water and salt contents, and it represented the highest GL that could maintain the soil surface moist within the soil columns. Both the SC and CS reached the maximum levels in these different soil profiles at a GL of 1.2 m. With the raise of soil depth, the RWC increased significantly, whereas the SC increased after an initial decrease. The mean SC values reached 0.96% in the top soil layer; however, the rates at which the CS and RWC decreased with the GL were significantly reduced. The RWC and SC presented the greatest variations at the medium (0.9-1.2 m) and shallow water levels (0.6 m) respectively, whereas the CS presented the greatest variation at the deep water level (1.5-1.8 m).The RWC, SC and CS in the soil columns were all closely related to the GL. However, the correlations among the parameters varied greatly within different soil profiles, and the most accurate predictions of the GL were derived from the RWC in the shallow soil layer or the SC in the top soil layer. A GL at 1.5-1.8 m was moderate for planting T. chinensis seedlings under saline groundwater conditions.

  2. Responses of Water and Salt Parameters to Groundwater Levels for Soil Columns Planted with Tamarix chinensis.

    Directory of Open Access Journals (Sweden)

    Jiangbao Xia

    Full Text Available Groundwater is the main water resource for plant growth and development in the saline soil of the Yellow River Delta in China. To investigate the variabilities and distributions of soil water and salt contents at various groundwater level (GL, soil columns with planting Tamarix chinensis Lour were established at six different GL. The results demonstrated the following: With increasing GL, the relative soil water content (RWC declined significantly, whereas the salt content (SC and absolute soil solution concentration (CS decreased after the initial increase in the different soil profiles. A GL of 1.2 m was the turning point for variations in the soil water and salt contents, and it represented the highest GL that could maintain the soil surface moist within the soil columns. Both the SC and CS reached the maximum levels in these different soil profiles at a GL of 1.2 m. With the raise of soil depth, the RWC increased significantly, whereas the SC increased after an initial decrease. The mean SC values reached 0.96% in the top soil layer; however, the rates at which the CS and RWC decreased with the GL were significantly reduced. The RWC and SC presented the greatest variations at the medium (0.9-1.2 m and shallow water levels (0.6 m respectively, whereas the CS presented the greatest variation at the deep water level (1.5-1.8 m.The RWC, SC and CS in the soil columns were all closely related to the GL. However, the correlations among the parameters varied greatly within different soil profiles, and the most accurate predictions of the GL were derived from the RWC in the shallow soil layer or the SC in the top soil layer. A GL at 1.5-1.8 m was moderate for planting T. chinensis seedlings under saline groundwater conditions.

  3. Responses of Water and Salt Parameters to Groundwater Levels for Soil Columns Planted with Tamarix chinensis

    Science.gov (United States)

    Xia, Jiangbao; Zhao, Ximei; Chen, Yinping; Fang, Ying; Zhao, Ziguo

    2016-01-01

    Groundwater is the main water resource for plant growth and development in the saline soil of the Yellow River Delta in China. To investigate the variabilities and distributions of soil water and salt contents at various groundwater level (GL), soil columns with planting Tamarix chinensis Lour were established at six different GL. The results demonstrated the following: With increasing GL, the relative soil water content (RWC) declined significantly, whereas the salt content (SC) and absolute soil solution concentration (CS) decreased after the initial increase in the different soil profiles. A GL of 1.2 m was the turning point for variations in the soil water and salt contents, and it represented the highest GL that could maintain the soil surface moist within the soil columns. Both the SC and CS reached the maximum levels in these different soil profiles at a GL of 1.2 m. With the raise of soil depth, the RWC increased significantly, whereas the SC increased after an initial decrease. The mean SC values reached 0.96% in the top soil layer; however, the rates at which the CS and RWC decreased with the GL were significantly reduced. The RWC and SC presented the greatest variations at the medium (0.9–1.2 m) and shallow water levels (0.6 m) respectively, whereas the CS presented the greatest variation at the deep water level (1.5–1.8 m).The RWC, SC and CS in the soil columns were all closely related to the GL. However, the correlations among the parameters varied greatly within different soil profiles, and the most accurate predictions of the GL were derived from the RWC in the shallow soil layer or the SC in the top soil layer. A GL at 1.5–1.8 m was moderate for planting T. chinensis seedlings under saline groundwater conditions. PMID:26730602

  4. Pregnant women in Timis County, Romania are exposed primarily to low-level (water consumption.

    Science.gov (United States)

    Neamtiu, Iulia; Bloom, Michael S; Gati, Gabriel; Goessler, Walter; Surdu, Simona; Pop, Cristian; Braeuer, Simone; Fitzgerald, Edward F; Baciu, Calin; Lupsa, Ioana Rodica; Anastasiu, Doru; Gurzau, Eugen

    2015-06-01

    Excessive arsenic content in drinking water poses health risks to millions of people worldwide. Inorganic arsenic (iAs) in groundwater exceeding the 10μg/l maximum contaminant level (MCL) set by the World Health Organization (WHO) is characteristic for intermediate-depth aquifers over large areas of the Pannonian Basin in Central Europe. In western Romania, near the border with Hungary, Arad, Bihor, and Timis counties use drinking water coming partially or entirely from iAs contaminated aquifers. In nearby Arad and Bihor counties, more than 45,000 people are exposed to iAs over 10μg/l via public drinking water sources. However, comparable data are unavailable for Timis County. To begin to address this data gap, we determined iAs in 124 public and private Timis County drinking water sources, including wells and taps, used by pregnant women participating in a case-control study of spontaneous loss. Levels in water sources were low overall (median=3.0; range=water sources compared to 10 women using uncontaminated sources for urine total iAs (6.6 vs. 5.0μg/l, P=0.24) and DMA (5.5 vs. 4.2μg/l, P=0.31). The results suggested that the origin of urine total iAs (r=0.35, P=0.13) and DMA (r=0.31, P=0.18) must have been not only iAs in drinking-water but also some other source. Exposure of pregnant women to arsenic via drinking water in Timis County appears to be lower than for surrounding counties; however, it deserves a more definitive investigation as to its origin and the regional distribution of its risk potential. Copyright © 2015 Elsevier GmbH. All rights reserved.

  5. Reservoir water level forecasting using group method of data handling

    Science.gov (United States)

    Zaji, Amir Hossein; Bonakdari, Hossein; Gharabaghi, Bahram

    2018-06-01

    Accurately forecasted reservoir water level is among the most vital data for efficient reservoir structure design and management. In this study, the group method of data handling is combined with the minimum description length method to develop a very practical and functional model for predicting reservoir water levels. The models' performance is evaluated using two groups of input combinations based on recent days and recent weeks. Four different input combinations are considered in total. The data collected from Chahnimeh#1 Reservoir in eastern Iran are used for model training and validation. To assess the models' applicability in practical situations, the models are made to predict a non-observed dataset for the nearby Chahnimeh#4 Reservoir. According to the results, input combinations (L, L -1) and (L, L -1, L -12) for recent days with root-mean-squared error (RMSE) of 0.3478 and 0.3767, respectively, outperform input combinations (L, L -7) and (L, L -7, L -14) for recent weeks with RMSE of 0.3866 and 0.4378, respectively, with the dataset from https://www.typingclub.com/st. Accordingly, (L, L -1) is selected as the best input combination for making 7-day ahead predictions of reservoir water levels.

  6. Voyageurs National Park: Water-level regulation and effects on water quality and aquatic biology

    Science.gov (United States)

    Christensen, Victoria G.; Maki, Ryan P.; LeDuc, Jaime F.

    2018-01-01

    Following dam installations in the remote Rainy Lake Basin during the early 1900s, water-level fluctuations were considered extreme (1914–1949) compared to more natural conditions. In 1949, the International Joint Commission (IJC), which sets rules governing dam operation on waters shared by the United States and Canada, established the first rule curves to regulate water levels on these waterbodies. However, rule curves established prior to 2000 were determined to be detrimental to the ecosystem. Therefore, the IJC implemented an order in 2000 to change rule curves and to restore a more natural water regime. After 2000, measured chlorophyll-a concentrations in the two most eutrophic water bodies decreased whereas concentrations in oligotrophic lakes did not show significant water-quality differences. Fish mercury data were inconclusive, due to the variation in water levels and fish mercury concentrations, but can be used by the IJC as part of a long term data set.

  7. Numerical simulation of thermomagnetic convection of cold water near its density maximum in a square enclosure under a magnetic quadrupole field

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Er; Sun, Xiaoqin; He, Yecong; Jiang, Changwei, E-mail: cw_jiang@163.com [School of Energy and Power Engineering, Changsha University of Science and Technology, Changsha 410114 (China)

    2017-06-15

    Natural convection of cold water near its density maximum in a square enclosure is studied numerically under the influence of a magnetic quadrupole field without gravity. A generalized model which includes a non-Boussinesq parabolic density–temperature relationship is established. The governing equations in primitive variables are discretized using the finite-volume method and solved using the SIMPLE algorithm. The effects of magnetic force number, Rayleigh number and density inversion parameter on flow and heat transfer characteristics are analyzed. The results show that the primary flow pattern depends mainly on the density inversion parameter. Multi-cellular flow structures are observed for certain ranges of density inversion parameter independent of the value of Rayleigh number and magnetic force number. The heat transfer changes non-monotonically under combined actions of the quadrupole magnetic field and density inversion. (paper)

  8. Optimization study of pressure-swing distillation for the separation process of a maximum-boiling azeotropic system of water-ethylenediamine

    Energy Technology Data Exchange (ETDEWEB)

    Fulgueras, Alyssa Marie; Poudel, Jeeban; Kim, Dong Sun; Cho, Jungho [Kongju National University, Cheonan (Korea, Republic of)

    2016-01-15

    The separation of ethylenediamine (EDA) from aqueous solution is a challenging problem because its mixture forms an azeotrope. Pressure-swing distillation (PSD) as a method of separating azeotropic mixture were investigated. For a maximum-boiling azeotropic system, pressure change does not greatly affect the azeotropic composition of the system. However, the feasibility of using PSD was still analyzed through process simulation. Experimental vapor liquid equilibrium data of water-EDA system was studied to predict the suitability of thermodynamic model to be applied. This study performed an optimization of design parameters for each distillation column. Different combinations of operating pressures for the low- and high-pressure columns were used for each PSD simulation case. After the most efficient operating pressures were identified, two column configurations, low-high (LP+HP) and high-low (HP+ LP) pressure column configuration, were further compared. Heat integration was applied to PSD system to reduce low and high temperature utility consumption.

  9. Optimization study of pressure-swing distillation for the separation process of a maximum-boiling azeotropic system of water-ethylenediamine

    International Nuclear Information System (INIS)

    Fulgueras, Alyssa Marie; Poudel, Jeeban; Kim, Dong Sun; Cho, Jungho

    2016-01-01

    The separation of ethylenediamine (EDA) from aqueous solution is a challenging problem because its mixture forms an azeotrope. Pressure-swing distillation (PSD) as a method of separating azeotropic mixture were investigated. For a maximum-boiling azeotropic system, pressure change does not greatly affect the azeotropic composition of the system. However, the feasibility of using PSD was still analyzed through process simulation. Experimental vapor liquid equilibrium data of water-EDA system was studied to predict the suitability of thermodynamic model to be applied. This study performed an optimization of design parameters for each distillation column. Different combinations of operating pressures for the low- and high-pressure columns were used for each PSD simulation case. After the most efficient operating pressures were identified, two column configurations, low-high (LP+HP) and high-low (HP+ LP) pressure column configuration, were further compared. Heat integration was applied to PSD system to reduce low and high temperature utility consumption.

  10. Does water-level fluctuation affect mercury methylation in wetland soils?

    Energy Technology Data Exchange (ETDEWEB)

    Branfireun, B.A.; Mitchell, C.P.J.; Iraci, J.M. [Toronto Univ., ON (Canada). Dept. of Geography; Krabbenhoft, D.P. [United States Geological Survey, Middleton, WI (United States); Fowle, D.A. [Kansas Univ., Lawrence, KS (United States). Dept. of Geology; Neudahl, L. [Minnesota Power, Duluth, MN (United States)

    2006-07-01

    Mercury (Hg) concentrations in fish vary considerably in freshwater lakes and reservoirs. However, the variations are not generally consistent with physical factors such as basin characteristics, wetland cover or lake chemistry. Pronounced differences in Hg concentrations in fish have been noted in the reservoirs of the St. Louis River system near Duluth Minnesota. The differences were observed between headwater reservoir systems with seasonal flooding and drawdown, and a peaking reservoir with approximately daily water level fluctuations during seasonal lower flow periods. It was suggested that these differences could be attributed to water level fluctuations in the reservoir which influenced the actual production of methylmercury (MeHg) in the surrounding wetland soils. In response to this hypothesis, the authors investigated the role of water level fluctuation in the production and mobilization of MeHg in sediments from wetlands that lie adjacent to a headwater reservoir, a peaking reservoir, and a nearby natural flowage lake used as a control. Preliminary field surveys of the wetland soils revealed that although the average MeHg concentrations in the headwater and peaking reservoir wetlands were not considerably different, both were much higher than the natural lake. Each site demonstrated high variability, but maximum MeHg concentrations ranged from 29.2 ng/g for the peaking reservoir to 4.44 ng/g at the natural lake. A laboratory experiment was therefore performed in which sediments from each wetland were subjected to different water level regimes. The purpose was to assess Hg methylation potential. Stable Hg isotopes were used at the beginning and end of the experiment. In order to determine if water level fluctuation can significantly change the methylation potential of wetland soils on its own, the microbial consortia will also be assessed during the laboratory experiment.

  11. Water level control for a nuclear steam generator

    International Nuclear Information System (INIS)

    Wen Tan

    2011-01-01

    Research highlights: → A water level control system for a nuclear steam generator (SG) is proposed. → The parameters of the control system are directly related to those of the plant model thus scheduling is easy to implement in practice. → The proposed gain-scheduled controller can achieve good performance at both low and high power levels. - Abstract: A water level control system for a nuclear steam generator (SG) is proposed. The control system consists of a feedback controller and a feedforward controller. The feedback controller is of first order, the feedforward controller is of second order, and parameters of the two controllers are directly related to the parameters of plant model thus scheduling is easy to implement in practice. Robustness and performance of the feedback and the feedforward controllers are analyzed in details and tuning of the two parameters of the controllers are discussed. Comparisons among a single robust controller, a multi-model controller and a gain-scheduled controller are studied. It is shown that the proposed gain-scheduled controller can achieve good performance at both low and high power levels.

  12. Comparative Analysis of Nitrate Levels in Pensacola Area Rain Water

    Science.gov (United States)

    Jacobs, J.; Caffrey, J. M.; Maestre, A.; Landing, W. M.

    2017-12-01

    Nitrate is an important constituent of acid rain and often correlated with atmospheric NOx levels. This link between air and water quality was tested over a course of summer 2017 and compared to data from 2005-2012. Rain water samples collected from late May through early July of 2017 were tested for pH and nitrate concentrations. These months were among the stormiest on record for the Northwest Florida region with a total rainfall of 648 mm. The data analyzed from these rain events was compared to previous data to show the trends of nitrate and pH levels in the rainwater. Median pH for this study was 5.2, higher than the medians between 2015-2012 which ranged from 4.2 to 5.0, while nitrate concentrations for this study were 15.2 µM. This contrasts with a significant drop in nitrate concentrations from 41 µM in 2005 and 2006 to around 12 µM between 2007 and 2012. The drop between 2006-7 was suspected to be a result of implementation of NOx controls at Plant Crist coal fired power plant and other Clean Air Act requirements. These inputs of nitrate and H+ ions from rainwater can have a significant influence water quality throughout the region.

  13. Amount of leachant and water absorption levels of wood treated with borates and water repellents.

    Science.gov (United States)

    Baysal, Ergun; Sonmez, Abdullah; Colak, Mehmet; Toker, Hilmi

    2006-12-01

    Wood protection efficacy of borates against biological agents, flame retardancy, and suitability to the environment is well known. Since borates can be applied to timber as water based solutions, they are preferred economically as well. Even though they are highly mobile in wood, boron compounds are widely used in timber preservation. Borates migrate in liquid and increase the hygroscopicity of wood in damp conditions. This study deals with the physical restriction of water access in wood by impregnating water repellent agents into wood to limit amount of leachant and water absorption levels of wood after boron treatment. Borates were incorporated with polyethylene glycol-400 (PEG-400) their bulking effect in wood was considered. Results indicated that the amount of leachates from wood treated with borates in PEG-400 was remarkably higher compared to those of wood treated with the aqueous solutions of borates. Water absorption (WA) levels of wood treated with aqueous solutions of borates were higher than those of their treated samples with the solutions in PEG-400. Secondary treatments of wood with the water repellent (WR) chemicals following borate impregnation reduced the leaching of chemicals from wood in water and also WA of the specimens were less than those of the wood treated with only borates from aqueous and PEG solutions. Styrene (St) was the most effective monomer among the other agents used in terms of immobility effect on borates and WA.

  14. Characteristics of coseismic water level changes at Tangshan well for the Wenchuan M S8.0 earthquake and its larger aftershocks

    Science.gov (United States)

    Yin, Baojun; Ma, Li; Chen, Huizhong; Huang, Jianping; Zhang, Chaojun; Wang, Wuxing

    2009-04-01

    Coseismic water level changes which may have been induced by the Wenchuan M S8.0 earthquake and its 15 larger aftershocks ( M S≥5.4) have been observed at Tangshan well. We analyze the correlation between coseismic parameters (maximum amplitude, duration, coseismic step and the time when the coseismic reach its maximum amplitude) and earthquake parameters (magnitude, well-epicenter distance and depth), and then compare the time when the coseismic oscillation reaches its maximum amplitude with the seismogram from Douhe seismic station which is about 16.3 km away from Tangshan well. The analysis indicates that magnitude is the main factor influencing the induced coseismic water level changes, and that the well-epicenter distance and depth have less influence. M S magnitude has the strongest correlation with the coseismic water level changes comparing to M W and M L magnitudes. There exists strong correlation between the maximum amplitude, step size and the oscillation duration. The water level oscillation and step are both caused by dynamic strain sourcing from seismic waves. Most of the times when the oscillations reach their maximum amplitudes are between S and Rayleigh waves. The coseismic water level changes are due to the co-effect of seismic waves and hydro-geological environments.

  15. The Water Level and Transport Regimes of the Lower Columbia River

    Science.gov (United States)

    Jay, D. A.

    2011-12-01

    Tidal rivers are vital, spatially extensive conduits of material from land to sea. Yet the tidal-fluvial regime remains poorly understood relative to the bordering fluvial and estuarine/coastal regimes with which it interacts. The 235km-long Lower Columbia River (LCR) consists of five zones defined by topographic constrictions: a 5km-long ocean-entrance, the lower estuary (15km), an energy-minimum (67km), the tidal river (142km), and a landslide zone (5km). Buoyant plume lift-off occurs within the entrance zone, which is dominated by tidal and wave energy. The lower estuary is strongly tidally, amplifies the semidiurnal tide, and has highly variable salinity intrusion. Tidal and fluvial influences are balanced in the wide energy-minimum, into which salinity intrudes during low-flow periods. It has a turbidity maximum and a dissipation minimum at its lower end, but a water-level variance minimum at its landward end. The tidal river shows a large increase in the ratio of fluvial-to-tidal energy in the landward direction and strong seasonal variations in tidal properties. Because tidal monthly water level variations are large, low waters are higher on spring than neap tides. The steep landslide zone has only weak tides and is the site of the most seaward hydropower dam. Like many dammed systems, the LCR has pseudo-tides: daily and weakly hydropower peaking waves that propagate seaward. Tidal constituent ratios vary in the alongchannel direction due to frictional non-linearities, the changing balance of dissipation vs. propagation, and power peaking. Long-term changes to the system have occurred due to climate change and direct human manipulation. Flood control, hydropower regulation, and diversion have reduced peak flows, total load and sand transport by ~45, 50 and 80%, respectively, causing a blue-shift in the flow and water level power spectra. Overbank flows have been largely eliminated through a redundant combination of diking and flow regulation. Export of sand

  16. Biomass, productivity and relative rate of photosynthesis of sphagnum at different water levels on a South Swedish peat bog

    International Nuclear Information System (INIS)

    Wallen, B.; Falkengren-Grerup, U.; Malmer, N.

    1988-01-01

    The distribution pattern of Spaghnum species on bogs follows a hummock-hollow gradient. S. Sect. Acutifolia (that is in this study S. Fuscum and S. rubellum combined) dominates hummock tops, ca 20 cm above the maximum water level with a green biomass of 50 g m --2 , S. magellanicum dominates at a lower level, about 5 cm above the water level with a green biomass of 75 g m -2 and S. cuspidatum dominates in the wettest hollows with a green biomass of about 50 g m -2 . In situ measurements of length growth of S. Sect. Acutifolia and S. magelanicum using a 14 CO 2 -labelling technique during three consecutive years, revealed an unexpectedly high between-year variation in length growth of 7-23 mm yr -1 , and 16-22 mm yr -1 , respectively. Consequently the dominating producer in the transition between hummock and hollow changes from year to year, probably depending on climatic conditions. In vitro experiments on the effects of different water levels of 2, 5, 10 and 20 cm below the moss surface, on photosynthetic activity of S. Sect. Acutifolia and S. magellanicum, measured by a second 14 CO 2 -technique, indicate optimal conditions for S. magellanicum at 10 cm above water level, and for S. Sect, Acutofolia at 20 cm above water level. Differences in capillary water transport capability between the species are more important than the sensitivity of photosynthesis to water stress in explaining field patterns of productivity and distribution

  17. Relative Sea Level, Tidal Range, and Extreme Water Levels in Boston Harbor from 1825 to 2016

    Science.gov (United States)

    Talke, S. A.; Kemp, A.; Woodruff, J. D.

    2017-12-01

    Long time series of water-level measurements made by tide gauges provide a rich and valuable observational history of relative sea-level change, the frequency and height of extreme water levels and evolving tidal regimes. However, relatively few locations have available tide-gauge records longer than 100 years and most of these places are in northern Europe. This spatio-temporal distribution hinders efforts to understand global-, regional- and local-scale trends. Using newly-discovered archival measurements, we constructed a 200 year, instrumental record of water levels, tides, and storm surges in Boston Harbor. We detail the recovery, datum reconstruction, digitization, quality assurance, and analysis of this extended observational record. Local, decadally-averaged relative sea-level rose by 0.28 ± 0.05 m since the 1820s, with an acceleration of 0.023 ±0.009 mm/yr2. Approximately 0.13 ± 0.02 m of the observed RSL rise occurred due to ongoing glacial isostatic adjustment, and the remainder occurred due to changes in ocean mass and volume associated with the onset of modern mean sea-level rise. Change-point analysis of the new relative sea level record confirms that anthropogenic rise began in 1924-1932, which is in agreement with global mean sea level estimates from the global tide gauge network. Tide range decreased by 5.5% between 1830 and 1910, likely due in large part to anthropogenic development. Storm tides in Boston Harbor are produced primarily by extratropical storms during the November-April time frame. The three largest storm tides occurred in 1851, 1909, and 1978. Because 90% of the top 20 storm tides since 1825 occurred during a spring tide, the secular change in tide range contributes to a slight reduction in storm tide magnitudes. However, non-stationarity in storm hazard was historically driven primarily by local relative sea-level rise; a modest 0.2 m increase in relative sea level reduces the 100 year high water mark to a once-in-10 year event.

  18. Global gray water footprint and water pollution levels related to anthropogenic nitrogen loads to fresh water

    NARCIS (Netherlands)

    Mekonnen, Mesfin; Hoekstra, Arjen Ysbert

    2015-01-01

    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,

  19. Formal specification and animation of a water level monitoring system

    International Nuclear Information System (INIS)

    Jackson, P.S.; Stokes, P.A.

    1993-03-01

    This report describes the Vienna Development Method (VDM), which is a formal method for software specification and development. VDM evolved out of attempts to use mathematics in programming language specifications in order to avoid ambiguities in specifications written in natural language. This report also describes the use of VDM for a real-time application, where it is used to formally specify the requirements of a water level monitoring system. The procedures and techniques used to produce an executable form (animation) of the specification are covered. (Author)

  20. Using inferential sensors for quality control of Everglades Depth Estimation Network water-level data

    Science.gov (United States)

    Petkewich, Matthew D.; Daamen, Ruby C.; Roehl, Edwin A.; Conrads, Paul

    2016-09-29

    The Everglades Depth Estimation Network (EDEN), with over 240 real-time gaging stations, provides hydrologic data for freshwater and tidal areas of the Everglades. These data are used to generate daily water-level and water-depth maps of the Everglades that are used to assess biotic responses to hydrologic change resulting from the U.S. Army Corps of Engineers Comprehensive Everglades Restoration Plan. The generation of EDEN daily water-level and water-depth maps is dependent on high quality real-time data from water-level stations. Real-time data are automatically checked for outliers by assigning minimum and maximum thresholds for each station. Small errors in the real-time data, such as gradual drift of malfunctioning pressure transducers, are more difficult to immediately identify with visual inspection of time-series plots and may only be identified during on-site inspections of the stations. Correcting these small errors in the data often is time consuming and water-level data may not be finalized for several months. To provide daily water-level and water-depth maps on a near real-time basis, EDEN needed an automated process to identify errors in water-level data and to provide estimates for missing or erroneous water-level data.The Automated Data Assurance and Management (ADAM) software uses inferential sensor technology often used in industrial applications. Rather than installing a redundant sensor to measure a process, such as an additional water-level station, inferential sensors, or virtual sensors, were developed for each station that make accurate estimates of the process measured by the hard sensor (water-level gaging station). The inferential sensors in the ADAM software are empirical models that use inputs from one or more proximal stations. The advantage of ADAM is that it provides a redundant signal to the sensor in the field without the environmental threats associated with field conditions at stations (flood or hurricane, for example). In the

  1. Surface Water Connectivity, Flow Pathways and Water Level Fluctuation in a Cold Region Deltaic Ecosystem

    Science.gov (United States)

    Peters, D. L.; Niemann, O.; Skelly, R.; Monk, W. A.; Baird, D. J.

    2017-12-01

    The Peace-Athabasca Delta (PAD) is a 6000 km2 deltaic floodplain ecosystem of international importance (Wood Buffalo National Park, Ramsar Convention, UNESCO World Heritage, and SWOT satellite water level calibration/validation site). The low-relief floodplain formed at the confluence of the Peace, Athabasca and Birch rivers with Lake Athabasca. More than 1000 wetland and lake basins have varying degrees of connectivity to the main flow system. Hydroperiod and water storage is influenced by ice-jam and open-water inundations and prevailing semi-arid climate that control water drawdown. Prior studies have identified pathways of river-to-wetland floodwater connection and historical water level fluctuation/trends as a key knowledge gaps, limiting our knowledge of deltaic ecosystem status and potential hydroecological responses to climate change and upstream water alterations to flow contributions. To address this knowledge gap, surface elevation mapping of the PAD has been conducted since 2012 using aerial remote sensing Light Detection and Ranging (LiDAR), plus thousands of ground based surface and bathymetric survey points tied to Global Positioning System (GPS) were obtained. The elevation information was used to develop a high resolution digital terrain model to simulate and investigate surface water connectivity. Importantly, the surveyed areas contain a set of wetland monitoring sites where ground-based surface water connectivity, water level/depth, water quality, and aquatic ecology (eg, vegetation, macroinvertebrate and muskrat) have been examined. The goal of this presentation is to present an assessment of: i) surface water fluctuation and connectivity for PAD wetland sites; ii) 40+ year inter-annual hydroperiod reconstruction for a perched basin using a combination of field measurements, remote sensing estimates, and historical documents; and iii) outline an approach to integrate newly available hydro-bio-geophysical information into a novel, multi

  2. Littoral zones in shallow lakes. Contribution to water quality in relation to water level regime

    NARCIS (Netherlands)

    Sollie, S.

    2007-01-01

    Littoral zones with emergent vegetation are very narrow or even lacking in Dutch shallow lakes due to a combination of changed water level regime and unfavorable shore morphometry. These zones are important as a habitat for plants and animals, increasing species diversity. It has also been

  3. 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; Larsen, Torben

    2014-01-01

    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...

  4. Spatiotemporal modeling of ozone levels in Quebec (Canada): a comparison of kriging, land-use regression (LUR), and combined Bayesian maximum entropy-LUR approaches.

    Science.gov (United States)

    Adam-Poupart, Ariane; Brand, Allan; Fournier, Michel; Jerrett, Michael; Smargiassi, Audrey

    2014-09-01

    Ambient air ozone (O3) is a pulmonary irritant that has been associated with respiratory health effects including increased lung inflammation and permeability, airway hyperreactivity, respiratory symptoms, and decreased lung function. Estimation of O3 exposure is a complex task because the pollutant exhibits complex spatiotemporal patterns. To refine the quality of exposure estimation, various spatiotemporal methods have been developed worldwide. We sought to compare the accuracy of three spatiotemporal models to predict summer ground-level O3 in Quebec, Canada. We developed a land-use mixed-effects regression (LUR) model based on readily available data (air quality and meteorological monitoring data, road networks information, latitude), a Bayesian maximum entropy (BME) model incorporating both O3 monitoring station data and the land-use mixed model outputs (BME-LUR), and a kriging method model based only on available O3 monitoring station data (BME kriging). We performed leave-one-station-out cross-validation and visually assessed the predictive capability of each model by examining the mean temporal and spatial distributions of the average estimated errors. The BME-LUR was the best predictive model (R2 = 0.653) with the lowest root mean-square error (RMSE ;7.06 ppb), followed by the LUR model (R2 = 0.466, RMSE = 8.747) and the BME kriging model (R2 = 0.414, RMSE = 9.164). Our findings suggest that errors of estimation in the interpolation of O3 concentrations with BME can be greatly reduced by incorporating outputs from a LUR model developed with readily available data.

  5. Finding of no significant impact: Interim storage of enriched uranium above the maximum historical level at the Y-12 Plant Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1995-01-01

    The US Department of Energy (DOE) has prepared an Environmental Assessment (EA) for the Proposed Interim Storage of Enriched Uranium Above the Maximum Historical Storage Level at the Y-12 Plant, Oak Ridge, Tennessee (DOE/EA-0929, September, 1994). The EA evaluates the environmental effects of transportation, prestorage processing, and interim storage of bounding quantities of enriched uranium at the Y-12 Plant over a ten-year period. The State of Tennessee and the public participated in public meetings and workshops which were held after a predecisional draft EA was released in February 1994, and after the revised pre-approval EA was issued in September 1994. Comments provided by the State and public have been carefully considered by the Department. As a result of this public process, the Department has determined that the Y-12 Plant-would store no more than 500 metric tons of highly enriched uranium (HEU) and no more than 6 metric tons of low enriched uranium (LEU). The bounding storage quantities analyzed in the pre-approval EA are 500 metric tons of HEU and 7,105.9 metric tons of LEU. Based on-the analyses in the EA, as revised by the attachment to the Finding of No Significant Impact (FONSI), DOE has determined that interim storage of 500 metric tons of HEU and 6 metric tons of LEU at the Y-12 Plant does not constitute a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, an Environmental Impact Statement (EIS) is not required and the Department is issuing this FONSI

  6. Modeling the evolution of the Laurentide Ice Sheet from MIS 3 to the Last Glacial Maximum: an approach using sea level modeling and ice flow dynamics

    Science.gov (United States)

    Weisenberg, J.; Pico, T.; Birch, L.; Mitrovica, J. X.

    2017-12-01

    The history of the Laurentide Ice Sheet since the Last Glacial Maximum ( 26 ka; LGM) is constrained by geological evidence of ice margin retreat in addition to relative sea-level (RSL) records in both the near and far field. Nonetheless, few observations exist constraining the ice sheet's extent across the glacial build-up phase preceding the LGM. Recent work correcting RSL records along the U.S. mid-Atlantic dated to mid-MIS 3 (50-35 ka) for glacial-isostatic adjustment (GIA) infer that the Laurentide Ice Sheet grew by more than three-fold in the 15 ky leading into the LGM. Here we test the plausibility of a late and extremely rapid glaciation by driving a high-resolution ice sheet model, based on a nonlinear diffusion equation for the ice thickness. We initialize this model at 44 ka with the mid-MIS 3 ice sheet configuration proposed by Pico et al. (2017), GIA-corrected basal topography, and mass balance representative of mid-MIS 3 conditions. These simulations predict rapid growth of the eastern Laurentide Ice Sheet, with rates consistent with achieving LGM ice volumes within 15 ky. We use these simulations to refine the initial ice configuration and present an improved and higher resolution model for North American ice cover during mid-MIS 3. In addition we show that assumptions of ice loads during the glacial phase, and the associated reconstructions of GIA-corrected basal topography, produce a bias that can underpredict ice growth rates in the late stages of the glaciation, which has important consequences for our understanding of the speed limit for ice growth on glacial timescales.

  7. A Receding Horizon Controller for the Steam Generator Water Level

    International Nuclear Information System (INIS)

    Na, Man Gyun; Lee, Yoon Joon

    2003-01-01

    In this work, the receding horizon control method was used to control the water level of nuclear steam generators and applied to two linear models and also a nonlinear model of steam generators. A receding horizon control method is to solve an optimization problem for finite future steps at current time and to implement the first optimal control input as the current control input. The procedure is then repeated at each subsequent instant. The dynamics of steam generators is very different according to power levels. The receding horizon controller is designed by using a reduced linear steam generator model fixed over a certain power range and applied to a Westinghouse-type (U-tube recirculating type) nuclear steam generator. The proposed controller designed at a fixed power level shows good performance for any other power level within this power range. The steam generator shows actually nonlinear characteristics. Therefore, the proposed algorithm is implemented for a nonlinear model of the nuclear steam generator to verify its real performance and also shows good responses

  8. Airborne Hyperspectral Evaluation of Maximum Gross Photosynthesis, Gravimetric Water Content, and CO2 Uptake Efficiency of the Mer Bleue Ombrotrophic Peatland

    Directory of Open Access Journals (Sweden)

    J. Pablo Arroyo-Mora

    2018-04-01

    Full Text Available Peatlands cover a large area in Canada and globally (12% and 3% of the landmass, respectively. These ecosystems play an important role in climate regulation through the sequestration of carbon dioxide from, and the release of methane to, the atmosphere. Monitoring approaches, required to understand the response of peatlands to climate change at large spatial scales, are challenged by their unique vegetation characteristics, intrinsic hydrological complexity, and rapid changes over short periods of time (e.g., seasonality. In this study, we demonstrate the use of multitemporal, high spatial resolution (1 m2 hyperspectral airborne imagery (Compact Airborne Spectrographic Imager (CASI and Shortwave Airborne Spectrographic Imager (SASI sensors for assessing maximum instantaneous gross photosynthesis (PGmax in hummocks, and gravimetric water content (GWC and carbon uptake efficiency in hollows, at the Mer Bleue ombrotrophic bog. We applied empirical models (i.e., in situ data and spectral indices and we derived spatial and temporal trends for the aforementioned variables. Our findings revealed the distribution of hummocks (51.2%, hollows (12.7%, and tree cover (33.6%, which is the first high spatial resolution map of this nature at Mer Bleue. For hummocks, we found growing season PGmax values between 8 μmol m−2 s−1 and 12 μmol m−2 s−1 were predominant (86.3% of the total area. For hollows, our results revealed, for the first time, the spatial heterogeneity and seasonal trends for gravimetric water content and carbon uptake efficiency for the whole bog.

  9. Temperature effect on the inter-micellar collision and maximum packaging volume fraction in water/AOT/isooctane micro-emulsions

    International Nuclear Information System (INIS)

    Guettari, Moez; Ben Naceur, Imen; Kassab, Ghazi; Tajouri, Tahar

    2016-01-01

    We have studied the viscosity behaviour of water/AOT/isooctane micro-emulsions as a function of the volume fraction of the dispersed phase over a temperature range from the (298.15 to 328.15) K. For all the studied temperature range, a sharp increase of the viscosities is observed when the droplets concentration was varied. Several equations based on hard sphere model were examined to explain the behaviours of micro-emulsions under temperature and concentration effects. According to these equations, the shape factor and the inter-particle interaction parameters were found to be dependent on temperature which is in contradiction with experimental results reported in the literature. A modified Vand equation, taking into account the inter-particle collision time, is used to interpret the results obtained. This deviation is attributed to the aggregation of the droplets which becomes important by increasing temperature. The maximum packaging volume fraction of particles Φ_d_m and the intrinsic viscosity [η] were determined according to the Krieger and Dougherty equation through the temperature range studied. These two parameters were shown to be dependent on temperature but their product was found to be constant and close to 2 as reported in theory.

  10. Assessing water pollution level and gray water footprint of anthropogenic nitrogen in agricultural system

    Science.gov (United States)

    Huang, Guorui; Chen, Han; Yu, Chaoqing

    2017-04-01

    Water pollution has become a global problem which is one of the most critical issues of today's water treatment. At a spatial resolution of 10km, we use the DeNitrification-DeComposition (DNDC) model to simulate the biogeochemical processes for major cropping systems from 1955 to 2014, estimate the anthropogenic nitrogen loads to fresh, and calculate the resultant grey water footprints and N-related water pollution level in China. The accumulated annual Nitrogen loads to fresh from agricultural system is 0.38Tg in 1955 and 4.42Tg in 2014, while the grey water footprints vary from 1.53 billion m3 to 17.67 billion m3, respectively. N loads in north of China contributes much more on the N leaching because of the high fertilizer but in south of China, it is mainly focused on the N runoff because of the heavy rain. There are more than 25% of grids with WPL>1 (exceed the water capacity of assimilation), which is mainly located on the North China Plain.

  11. Influence of irrigation water types and stress levels on cotton fibre and yarn quality for different varieties

    International Nuclear Information System (INIS)

    Nazar, A.; Ishaq, W.

    2012-01-01

    Cotton fibre quality is being deteriorated day by day due to various reasons and shortage/ poor quality of irrigation water is one of the reasons for the low quality of cotton fibre. The effect of the stress of water can be seen on the fibre length, strength and elongation. All these properties of fibre have also a significant influence on yarn characteristics and thus the yarn quality is also dependent on agronomic practices including irrigation. When new varieties are evolved it becomes necessary to examine such cotton varieties keenly, so that one which reflects maximum agricultural as well as industrial benefits can be recommended. The present study was planned to explore the spinning performance of various cotton varieties under different water quality treatments and water stress levels. Cotton of four varieties (CIM-501, CIM-496, CIM-499, and NIAB-111) under different types of irrigation water (canal water and tube well water) and different water stress levels (75ET, 100ET and 125ET) were selected for this research. The effect of these treatments was investigated on cotton fibre span length, strength and fibre elongation as well as on yarn quality. The study revealed that effect of different cotton varieties, water types and water stress levels on fibre and yarn quality was highly significant. Yarn characteristics showed greater values for the canal water similarly fibre length and elongations were better for canal water. Yarn tensile properties were decreased with increase in the water stress. The overall results indicated that the cotton variety NIAB-111 performed better as compared to other varieties. It is suggested that the cotton farmers may be trained by the agri. extension staff regarding maintenance of fibre quality through cultural practices and better irrigation techniques. (author)

  12. Global Anthropogenic Phosphorus Loads to Fresh Water, Grey Water Footprint and Water Pollution Levels: A High-Resolution Global Study

    Science.gov (United States)

    Mekonnen, M. M.; Hoekstra, A. Y. Y.

    2014-12-01

    We estimated anthropogenic phosphorus (P) loads to freshwater, globally at a spatial resolution level of 5 by 5 arc minute. The global anthropogenic P load to freshwater systems from both diffuse and point sources in the period 2002-2010 was 1.5 million tonnes per year. China contributed about 30% to this global anthropogenic P load. India was the second largest contributor (8%), followed by the USA (7%), Spain and Brazil each contributing 6% to the total. The domestic sector contributed the largest share (54%) to this total followed by agriculture (38%) and industry (8%). Among the crops, production of cereals had the largest contribution to the P loads (32%), followed by fruits, vegetables, and oil crops, each contributing about 15% to the total. We also calculated the resultant grey water footprints, and relate the grey water footprints per river basin to runoff to calculate the P-related water pollution level (WPL) per catchment.

  13. Ensemble-based evaluation of extreme water levels for the eastern Baltic Sea

    Science.gov (United States)

    Eelsalu, Maris; Soomere, Tarmo

    2016-04-01

    The risks and damages associated with coastal flooding that are naturally associated with an increase in the magnitude of extreme storm surges are one of the largest concerns of countries with extensive low-lying nearshore areas. The relevant risks are even more contrast for semi-enclosed water bodies such as the Baltic Sea where subtidal (weekly-scale) variations in the water volume of the sea substantially contribute to the water level and lead to large spreading of projections of future extreme water levels. We explore the options for using large ensembles of projections to more reliably evaluate return periods of extreme water levels. Single projections of the ensemble are constructed by means of fitting several sets of block maxima with various extreme value distributions. The ensemble is based on two simulated data sets produced in the Swedish Meteorological and Hydrological Institute. A hindcast by the Rossby Centre Ocean model is sampled with a resolution of 6 h and a similar hindcast by the circulation model NEMO with a resolution of 1 h. As the annual maxima of water levels in the Baltic Sea are not always uncorrelated, we employ maxima for calendar years and for stormy seasons. As the shape parameter of the Generalised Extreme Value distribution changes its sign and substantially varies in magnitude along the eastern coast of the Baltic Sea, the use of a single distribution for the entire coast is inappropriate. The ensemble involves projections based on the Generalised Extreme Value, Gumbel and Weibull distributions. The parameters of these distributions are evaluated using three different ways: maximum likelihood method and method of moments based on both biased and unbiased estimates. The total number of projections in the ensemble is 40. As some of the resulting estimates contain limited additional information, the members of pairs of projections that are highly correlated are assigned weights 0.6. A comparison of the ensemble-based projection of

  14. Natural radioactivity levels in different mineral waters from Bulgaria

    Energy Technology Data Exchange (ETDEWEB)

    Kamenova-Totzeva, R.; Kotova, R.; Tenev, J.; Ivanova, G.; Badulin, V. [Public Exposure Monitoring Laboratory, National Centre of Radiobiology and Radiation Protection, Sofia (Bulgaria)

    2013-07-01

    The total radioactivity content of 76 mineral waters from different districts in Bulgaria was determined. Natural radioactivity levels resulting from uranium, radium-226, gross alpha and gross beta activity were measured. The results show that the specific activity range from < 0.02 Bq/l to 1.34 (12) Bq/l and from 0.068 (23) Bq/l to 2.60 (50) Bq/l for gross alpha and gross beta activity respectively. For natural Uranium the results vary between 0.020 (5) μg/l and 180(50) μg/l. Radium-226 content is between < 0.03 Bq/l to 0.296 (75) Bq/l. Due to differences in the geological structure of the aquifer, a large difference in values of the radioactive content was mSv/year. Excluding one value, TID do not exceed the permissible limit of 0.10 mSv/year. The correlations between investigated isotopes and Total Dissolved observed. The estimated Total Indicative Dose (TID) ranged from 0.0113 (57) mSv/year to 0.1713 (481) Solvents (TDS) in water were carried out. The results do not show a strong correlation between TDS values and dissolved radionuclides. (author)

  15. NOAA tsunami water level archive - scientific perspectives and discoveries

    Science.gov (United States)

    Mungov, G.; Eble, M. C.; McLean, S. J.

    2013-12-01

    The National Oceanic and Atmospheric Administration (NOAA) National Geophysical Data Center (NGDC) and co-located World Data Service for Geophysics (WDS) provides long-term archive, data management, and access to national and global tsunami data. Currently, NGDC archives and processes high-resolution data recorded by the Deep-ocean Assessment and Reporting of Tsunami (DART) network, the coastal-tide-gauge network from the National Ocean Service (NOS) as well as tide-gauge data recorded by all gauges in the two National Weather Service (NWS) Tsunami Warning Centers' (TWCs) regional networks. The challenge in processing these data is that the observations from the deep-ocean, Pacific Islands, Alaska region, and United States West and East Coasts display commonalities, but, at the same time, differ significantly, especially when extreme events are considered. The focus of this work is on how time integration of raw observations (10-seconds to 1-minute) could mask extreme water levels. Analysis of the statistical and spectral characteristics obtained from records with different time step of integration will be presented. Results show the need to precisely calibrate the despiking procedure against raw data due to the significant differences in the variability of deep-ocean and coastal tide-gauge observations. It is shown that special attention should be drawn to the very strong water level declines associated with the passage of the North Atlantic cyclones. Strong changes for the deep ocean and for the West Coast have implications for data quality but these same features are typical for the East Coast regime.

  16. 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.

  17. OPTIMIZATION OF TRANSIEN PROCESSES OF WATER LEVEL VARIATION IN DRUM OF STEAM BOILERS

    Directory of Open Access Journals (Sweden)

    G. T. Kulakov

    2014-01-01

    Full Text Available The work of regulator in general three-impulse automatic control system of water level in drum of boiler doesn’t supply quality of internal and external disturbance attack (presentation of regulation mistakes. That is why it is needed to improve. Different methods of proportional plus reset controller regulation of three-phase automatic feed control system are considered. There were suggested new methods to improve the quality of regulation of water level in boilers. Here the step system of automatic regulation was determined, on the base of transfer function.It is noticed that optimal transient processes supply calculation of numerical value of transmission factor of regulator at g =2,618, it is more then was recommended, but statistic mistakes remain. The transient simulation method in fast-time scale is recommended, this allow to determine early the value of statistic mistake of regulation by disturbances of reheated steam consumption and properly change the task to compensating device of step automatic control system. And numerical value of time constant criteria  should be calculated on the base of numbers of golden section(Phi, taking into account the definite time constant of lead section and time-lag, time-lag on controlled influence channel, and also taking into account maximum value of controlled influence. This method allow to reduce in two times the total time of regulation, to decrease absolute mistake of regulation in three times, and maximum value of regulation influence by feedwater in 1,7 times.

  18. Hydraulic Limits on Maximum Plant Transpiration

    Science.gov (United States)

    Manzoni, S.; Vico, G.; Katul, G. G.; Palmroth, S.; Jackson, R. B.; Porporato, A. M.

    2011-12-01

    Photosynthesis occurs at the expense of water losses through transpiration. As a consequence of this basic carbon-water interaction at the leaf level, plant growth and ecosystem carbon exchanges are tightly coupled to transpiration. In this contribution, the hydraulic constraints that limit transpiration rates under well-watered conditions are examined across plant functional types and climates. The potential water flow through plants is proportional to both xylem hydraulic conductivity (which depends on plant carbon economy) and the difference in water potential between the soil and the atmosphere (the driving force that pulls water from the soil). Differently from previous works, we study how this potential flux changes with the amplitude of the driving force (i.e., we focus on xylem properties and not on stomatal regulation). Xylem hydraulic conductivity decreases as the driving force increases due to cavitation of the tissues. As a result of this negative feedback, more negative leaf (and xylem) water potentials would provide a stronger driving force for water transport, while at the same time limiting xylem hydraulic conductivity due to cavitation. Here, the leaf water potential value that allows an optimum balance between driving force and xylem conductivity is quantified, thus defining the maximum transpiration rate that can be sustained by the soil-to-leaf hydraulic system. To apply the proposed framework at the global scale, a novel database of xylem conductivity and cavitation vulnerability across plant types and biomes is developed. Conductivity and water potential at 50% cavitation are shown to be complementary (in particular between angiosperms and conifers), suggesting a tradeoff between transport efficiency and hydraulic safety. Plants from warmer and drier biomes tend to achieve larger maximum transpiration than plants growing in environments with lower atmospheric water demand. The predicted maximum transpiration and the corresponding leaf water

  19. In Conversation: David Brooks on Water Scarcity and Local-level ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-11-26

    Nov 26, 2010 ... While sound water management requires action from all levels, ... Local management is certainly an essential component in managing the world's water crisis. ... case studies that show the promise of local water management.

  20. Effect of Different Levels of Irrigation Water on Quantitative and Qualitative Characteristics of Potato and Determination of Its Optimum Consumptive Use of Water in Shahrekord

    Directory of Open Access Journals (Sweden)

    masoud Naderi

    2017-01-01

    SAS and EXCEL software, respectively. Results Discussion: The effect of different levels of irrigation water on yield was significant at 1%. The yield increased with increase of irrigation water. The minimum and maximum yields were belonged to 40 and 130 % treatments with 13.2 and 45.2 tons per hectare, respectively. Whereas, the results revealed that treatments which recieved100, 115 and 130% of the soil moisture deficit had no significant effect on potato yield at 5% level. Thus, potato yield in 115 and 130% treatments were only 2.3 and 3.9% more than treatment receiving full irrigation, respectively. The potato production function was obtained using the depth of water which consumed during the growing season and yield in each treatment. The results showed that the effect of different levels of irrigation water was significant on yield, starch, soluble sugars, dry matter, irrigation water use efficiency and the weight of tuber production per plant in marketable size As the level of irrigation water increased, the yield, soluble sugars content and weight of tuber per plant in marketable size increased and the starch and dry matter content decreased. Moreover, effect of different levels of irrigation water on nitrogen percent and the weight of tuber in seed size were not significant. Maximum and minimum of irrigation water use efficiency were belonged to 85 and 40% with values of 6.96 and 4.84 Kg m-3, respectively. Maximum and minimum percentages of starch were belonged to 40 and 130% treatments with values of 76.6 and 61%, respectively. The soluble sugar content in potato can causes discoloration and darkness of the product, and accordingly it makes the non-marketability of the product. Maximum and minimum soluble sugar contents were belonged to 130 and 40% treatments with values of 2.12 and 3.07%, respectively. In addition, the increase of irrigation water caused to the increase of weight of tuber per plant in marketable size. Therefore, the highest marketable tuber

  1. The last glacial maximum

    Science.gov (United States)

    Clark, P.U.; Dyke, A.S.; Shakun, J.D.; Carlson, A.E.; Clark, J.; Wohlfarth, B.; Mitrovica, J.X.; Hostetler, S.W.; McCabe, A.M.

    2009-01-01

    We used 5704 14C, 10Be, and 3He ages that span the interval from 10,000 to 50,000 years ago (10 to 50 ka) to constrain the timing of the Last Glacial Maximum (LGM) in terms of global ice-sheet and mountain-glacier extent. Growth of the ice sheets to their maximum positions occurred between 33.0 and 26.5 ka in response to climate forcing from decreases in northern summer insolation, tropical Pacific sea surface temperatures, and atmospheric CO2. Nearly all ice sheets were at their LGM positions from 26.5 ka to 19 to 20 ka, corresponding to minima in these forcings. The onset of Northern Hemisphere deglaciation 19 to 20 ka was induced by an increase in northern summer insolation, providing the source for an abrupt rise in sea level. The onset of deglaciation of the West Antarctic Ice Sheet occurred between 14 and 15 ka, consistent with evidence that this was the primary source for an abrupt rise in sea level ???14.5 ka.

  2. Impact of maintenance of floodplains of the Vistula River on high water levels on the section from Włocławek to Toruń

    Directory of Open Access Journals (Sweden)

    Dariusz Gąsiorowski

    2013-09-01

    Full Text Available This article describes the methodology of hydraulic calculations to estimate the water levels in open channels for steady gradually varied flow. The presented method has been used to analyse the water level on the Vistula River from Włocławek cross-section to Toruń cross-section. The HEC-RAS modelling system has been used for parameterization of the river channel and floodplains, as well as for flow simulation. The results obtained have been the basis for assessing the impact of maintenance of floodplains on water level during maximum discharges.

  3. Modelling maximum canopy conductance and transpiration in ...

    African Journals Online (AJOL)

    There is much current interest in predicting the maximum amount of water that can be transpired by Eucalyptus trees. It is possible that industrial waste water may be applied as irrigation water to eucalypts and it is important to predict the maximum transpiration rates of these plantations in an attempt to dispose of this ...

  4. Development of a Health-Protective Drinking Water Level for Perchlorate

    Science.gov (United States)

    Ting, David; Howd, Robert A.; Fan, Anna M.; Alexeeff, George V.

    2006-01-01

    We evaluated animal and human toxicity data for perchlorate and identified reduction of thyroidal iodide uptake as the critical end point in the development of a health-protective drinking water level [also known as the public health goal (PHG)] for the chemical. This work was performed under the drinking water program of the Office of Environmental Health Hazard Assessment of the California Environmental Protection Agency. For dose–response characterization, we applied benchmark-dose modeling to human data and determined a point of departure (the 95% lower confidence limit for 5% inhibition of iodide uptake) of 0.0037 mg/kg/day. A PHG of 6 ppb was calculated by using an uncertainty factor of 10, a relative source contribution of 60%, and exposure assumptions specific to pregnant women. The California Department of Health Services will use the PHG, together with other considerations such as economic impact and engineering feasibility, to develop a California maximum contaminant level for perchlorate. We consider the PHG to be adequately protective of sensitive subpopulations, including pregnant women, their fetuses, infants, and people with hypothyroidism. PMID:16759989

  5. A Quick Review on Steam Generator Water Level Tracking Methods and Its Uncertainties

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ki Moon; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of)

    2016-05-15

    The tracking of the SG water level is important for maintaining the heat removal of the reactor and the power plant safety. In addition, the SG water level is important for the reactor trip and the actuation of SG back-up feedwater system as well. The SG water level is mainly controlled by the Feed Water Control System (FWCS) during either normal operation or transients therefore, the selection of the FWCS control parameters is also important. In this paper, methods of SG water level calculation are first reviewed and future works to perform sensitivity study of the SG water level calculation with a system analysis code will be identified. This is partially shown from Loss-of-feedwater experiments carried out in PACTEL and the LOF-10 experiment. The experiment was chosen to test the modeling capabilities of TRACE code for VVER SG. The experiment measured the water level with the pressure differential and the code calculated the water level directly from the code results. In this paper, three previously suggested parameters which can be used as an indicator of the SG water level are briefly introduced: (1) downcomer collapsed water level, (2) water mass inventory and (3) pressure differential. From the review of previous works, it was identified that most of the system analysis code calculates the SG water level directly by using the downcomer collapsed level. In contrast, the pressure difference is measured as used for the SG water level tracking in a real nuclear power plant or experiment.

  6. Geographical distribution of drinking-water with high iodine level and association between high iodine level in drinking-water and goitre: a Chinese national investigation.

    Science.gov (United States)

    Shen, Hongmei; Liu, Shoujun; Sun, Dianjun; Zhang, Shubin; Su, Xiaohui; Shen, Yanfeng; Han, Hepeng

    2011-07-01

    Excessive iodine intake can cause thyroid function disorders as can be caused by iodine deficiency. There are many people residing in areas with high iodine levels in drinking-water in China. The main aim of the present study was to map the geographical distribution of drinking-water with high iodine level in China and to determine the relationship between high iodine level in drinking-water and goitre prevalence. Iodine in drinking-water was measured in 1978 towns of eleven provinces in China, with a total of 28,857 water samples. We randomly selected children of 8-10 years old, examined the presence of goitre and measured their urinary iodine in 299 towns of nine provinces. Of the 1978 towns studied, 488 had iodine levels between 150 and 300 μg/l in drinking-water, and in 246 towns, the iodine level was >300 μg/l. These towns are mainly distributed along the original Yellow River flood areas, the second largest river in China. Of the 56 751 children examined, goitre prevalence was 6.3 % in the areas with drinking-water iodine levels of 150-300 μg/l and 11.0 % in the areas with drinking-water iodine >300 μg/l. Goitre prevalence increased with water and urinary iodine levels. For children with urinary iodine >1500 μg/l, goitre prevalence was 3.69 times higher than that for those with urinary iodine levels of 100-199 μg/l. The present study suggests that drinking-water with high iodine levels is distributed in eleven provinces of China. Goitre becomes more prevalent with the increase in iodine level in drinking-water. Therefore, it becomes important to prevent goitre through stopping the provision of iodised salt and providing normal drinking-water iodine through pipelines in these areas in China.

  7. Low-Cost Alternative for the Measurement of Water Levels in Surface Water Streams

    Directory of Open Access Journals (Sweden)

    Luis E. PEÑA

    2017-11-01

    Full Text Available Flood risk management and water resources planning involve a deep knowledge of surface streams so that mitigation strategies and climate change adaptations can be implemented. Commercially, there is a wide range of technologies for the measurement of hydroclimatic variables; however, many of these technologies may not be affordable for institutions with limited budgets. This paper has two main objectives: 1 Present the design of an ultrasound-based water level measurement system, and 2 Propose a methodological alternative for the development of instruments, according to the needs of institutions conducting monitoring of surface waterbodies. To that end, the proposed methodology is based on selection processes defined according to the specific needs of each waterbody. The prototype was tested in real-world scale, with the potential to obtain accurate measurements. Lastly, we present the design of the ultrasound-based water level measurement instrument, which can be built at a low cost. Low-cost instruments can potentially contribute to the sustainable instrumental autonomy of environmental entities and help define measurement and data transmission standards based on the specific requirements of the monitoring.

  8. Ground-water discharge determined from measurements of evapotranspiration, other available hydrologic components, and shallow water-level changes, Oasis Valley, Nye County, Nevada

    International Nuclear Information System (INIS)

    Reiner, S.R.; Laczniak, R.J.; DeMeo, G.A.; Smith LaRue, J.; Elliott, P.E.; Nylund, W.E.; Fridrich, C.J.

    2002-01-01

    component of 0.5 foot, is estimated to be about 6,000 acre-feet. Annual subsurface outflow from Oasis Valley into the Amargosa Desert is estimated to be between 30 and 130 acre-feet. Estimates of total annual ground-water withdrawal from Oasis Valley by municipal and non-municipal users in 1996 and 1999 are 440 acre-feet and 210 acre-feet, respectively. Based on these values, natural annual ground-water discharge from Oasis Valley is about 6,100 acre-feet. Total annual discharge was 6,500 acre-feet in 1996 and 6,300 acre-feet in 1999. This quantity of natural ground-water discharge from Oasis Valley exceeds the previous estimate made in 1962 by a factor of about 2.5. Water levels were measured in Oasis Valley to gain additional insight into the ET process. In shallow wells, water levels showed annual fluctuations as large as 7 feet and daily fluctuations as large as 0.2 foot. These fluctuations may be attributed to water loss associated with evapotranspiration. In shallow wells affected by E T, annual minimum depths to water generally occurred in winter or early spring shortly after daily ET reached minimum rates. Annual maximum depths to water generally occurred in late summer or fall shortly after daily ET reached maximum rates. The magnitude of daily water-level fluctuations generally increased as ET increased and decreased as depth to water increased

  9. Tide-surge historical assessment of extreme water levels for the St. Johns River: 1928-2017

    Science.gov (United States)

    Bacopoulos, Peter

    2017-10-01

    An historical storm population is developed for the St. Johns River, located in northeast Florida-US east coast, via extreme value assessment of an 89-year-long record of hourly water-level data. Storm surge extrema and the corresponding (independent) storm systems are extracted from the historical record as well as the linear and nonlinear trends of mean sea level. Peaks-over-threshold analysis reveals the top 16 most-impactful (storm surge) systems in the general return-period range of 1-100 years. Hurricane Matthew (2016) broke the record with a new absolute maximum water level of 1.56 m, although the peak surge occurred during slack tide level (0.00 m). Hurricanes and tropical systems contribute to return periods of 10-100 years with water levels in the approximate range of 1.3-1.55 m. Extratropical systems and nor'easters contribute to the historical storm population (in the general return-period range of 1-10 years) and are capable of producing extreme storm surges (in the approximate range of 1.15-1.3 m) on par with those generated by hurricanes and tropical systems. The highest astronomical tide is 1.02 m, which by evaluation of the historical record can contribute as much as 94% to the total storm-tide water level. Statically, a hypothetical scenario of Hurricane Matthew's peak surge coinciding with the highest astronomical tide would yield an overall storm-tide water level of 2.58 m, corresponding to an approximate 1000-year return period by historical comparison. Sea-level trends (linear and nonlinear) impact water-level return periods and constitute additional risk hazard for coastal engineering designs.

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

    International Nuclear Information System (INIS)

    Kuan, C.C.; Lin, C.; Hsu, C.C.

    1992-01-01

    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

  11. Effects of reservoirs water level variations on fish recruitment

    Directory of Open Access Journals (Sweden)

    Fabíula T. de Lima

    2017-10-01

    Full Text Available ABSTRACT The construction of hydroelectric power plants has many social and environmental impacts. Among them, the impacts on fish communities, which habitats are drastically modified by dams, with consequences across the ecosystem. This study aimed to assess the influence of water level (WL variations in the reservoirs of the Itá and Machadinho hydroelectric plants on the recruitment of fish species from the upper Uruguay River in southern Brazil. The data analyzed resulted from the WL variation produced exclusively by the hydroelectric plants generation and were collected between the years 2001 and 2012. The results showed significant correlations between the abundance of juvenile fish and the hydrological parameters only for some reproductive guilds. The species that spawn in nests showed, in general, a clear preference for the stability in the WL of the reservoirs, while the species that spawn in macrophytes or that release demersal eggs showed no significant correlation between the abundance of juvenile fish and hydrological parameters. A divergence of results between the two reservoirs was observed between the species that release semi-dense eggs; a positive correlation with a more stable WL was only observed in the Machadinho reservoir. This result can be driven by a wider range of WL variation in Machadinho reservoir.

  12. Impacts of water level fluctuation on mesotrophic rich fens: acidification versus eutrophication

    NARCIS (Netherlands)

    Cusell, C.; Lamers, L.P.M.; van Wirdum, G.; Kooijman, A.

    2013-01-01

    Water levels in areas with intensive agriculture have often been strictly controlled for decades. Recently, more natural fluctuating water levels have been propagated to improve the ecological quality of wetlands in these areas. This study investigated the effects of water levels on protected

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

    International Nuclear Information System (INIS)

    Boucher, M.S.

    1994-01-01

    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

  14. Lake Storage Measurements For Water Resources Management: Combining Remotely Sensed Water Levels and Surface Areas

    Science.gov (United States)

    Brakenridge, G. R.; Birkett, C. M.

    2013-12-01

    Presently operating satellite-based radar altimeters have the ability to monitor variations in surface water height for large lakes and reservoirs, and future sensors will expand observational capabilities to many smaller water bodies. Such remote sensing provides objective, independent information where in situ data are lacking or access is restricted. A USDA/NASA (http://www.pecad.fas.usda.gov/cropexplorer/global_reservoir/) program is performing operational altimetric monitoring of the largest lakes and reservoirs around the world using data from the NASA/CNES, NRL, and ESA missions. Public lake-level products from the Global Reservoir and Lake Monitor (GRLM) are a combination of archived and near real time information. The USDA/FAS utilizes the products for assessing international irrigation potential and for crop production estimates; other end-users study climate trends, observe anthropogenic effects, and/or are are involved in other water resources management and regional water security issues. At the same time, the Dartmouth Flood Observatory (http://floodobservatory.colorado.edu/), its NASA GSFC partners (http://oas.gsfc.nasa.gov/floodmap/home.html), and associated MODIS data and automated processing algorithms are providing public access to a growing GIS record of the Earth's changing surface water extent, including changes related to floods and droughts. The Observatory's web site also provide both archival and near real time information, and is based mainly on the highest spatial resolution (250 m) MODIS bands. Therefore, it is now possible to provide on an international basis reservoir and lake storage change measurements entirely from remote sensing, on a frequently updating basis. The volume change values are based on standard numerical procedures used for many decades for analysis of coeval lake area and height data. We provide first results of this combination, including prototype displays for public access and data retrieval of water storage

  15. AP1000 Shield Building Dynamic Response for Different Water Levels of PCCWST Subjected to Seismic Loading considering FSI

    Directory of Open Access Journals (Sweden)

    Daogang Lu

    2015-01-01

    Full Text Available Huge water storage tank on the top of many buildings may affect the safety of the structure caused by fluid-structure interaction (FSI under the earthquake. AP1000 passive containment cooling system water storage tank (PCCWST placed at the top of shield building is a key component to ensure the safety of nuclear facilities. Under seismic loading, water will impact the wall of PCCWST, which may pose a threat to the integrity of the shield building. In the present study, an FE model of AP1000 shield building is built for the modal and transient seismic analysis considering the FSI. Six different water levels in PCCWST were discussed by comparing the modal frequency, seismic acceleration response, and von Mises stress distribution. The results show the maximum von Mises stress emerges at the joint of shield building roof and water around the air inlet. However, the maximum von Mises stress is below the yield strength of reinforced concrete. The results may provide a reference for design of the AP1000 and CAP1400 in the future.

  16. Approximate maximum parsimony and ancestral maximum likelihood.

    Science.gov (United States)

    Alon, Noga; Chor, Benny; Pardi, Fabio; Rapoport, Anat

    2010-01-01

    We explore the maximum parsimony (MP) and ancestral maximum likelihood (AML) criteria in phylogenetic tree reconstruction. Both problems are NP-hard, so we seek approximate solutions. We formulate the two problems as Steiner tree problems under appropriate distances. The gist of our approach is the succinct characterization of Steiner trees for a small number of leaves for the two distances. This enables the use of known Steiner tree approximation algorithms. The approach leads to a 16/9 approximation ratio for AML and asymptotically to a 1.55 approximation ratio for MP.

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

    International Nuclear Information System (INIS)

    Li Nianzu; Li Beicheng; Jia Shengming

    1993-10-01

    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

  18. Maximum permissible dose

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    This chapter presents a historic overview of the establishment of radiation guidelines by various national and international agencies. The use of maximum permissible dose and maximum permissible body burden limits to derive working standards is discussed

  19. Preliminary assessment of a water-quality monitoring program for total maximum daily loads in Johnson County, Kansas, January 2015 through June 2016

    Science.gov (United States)

    Rasmussen, Teresa J.; Paxson, Chelsea R.

    2017-08-25

    Municipalities in Johnson County in northeastern Kansas are required to implement stormwater management programs to reduce pollutant discharges, protect water quality, and comply with applicable water-quality regulations in accordance with National Pollutant Discharge Elimination System permits for stormwater discharge. To this end, municipalities collect grab samples at streams entering and leaving their jurisdiction to determine levels of excessive nutrients, sediment, and fecal bacteria to characterize pollutants and understand the factors affecting them.In 2014, the U.S. Geological Survey and the Johnson County Stormwater Management Program, with input from the Kansas Department of Health and Environment, initiated a 5-year monitoring program to satisfy minimum sampling requirements for each municipality as described by new stormwater permits issued to Johnson County municipalities. The purpose of this report is to provide a preliminary assessment of the monitoring program. The monitoring program is described, a preliminary assessment of the monitoring program design is provided using water-quality data collected during the first 2 years of the program, and the ability of the current monitoring network and sampling plan to provide data sufficient to quantify improvements in water quality resulting from implemented and planned best management practices is evaluated. The information in this initial report may be used to evaluate changes in data collection methods while data collection is still ongoing that may lead to improved data utility.Discrete water-quality samples were collected at 27 sites and analyzed for nutrients, Escherichia coli (E. coli) bacteria, total suspended solids, and suspended-sediment concentration. In addition, continuous water-quality data (water temperature, pH, dissolved oxygen, specific conductance, turbidity, and nitrate plus nitrite) were collected at one site to characterize variability and provide a basis for comparison to discrete

  20. Assessing maize foliar water stress levels under field conditions ...

    African Journals Online (AJOL)

    The management of spectral reflectance data to extract information of importance for plant water status has been motivated by knowledge of the availability of specific bands in the electromagnetic spectrum responsible for water absorption. The purpose of this study was to investigate the potential of using selected spectral ...

  1. Evaluation of starter dietary digestible lysine level on broilers raised under a sex-separated or straight-run housing regime, part 2: Economics of sex separation and digestible lysine level for maximum returns.

    Science.gov (United States)

    Da Costa, M J; Colson, G; Frost, T J; Halley, J; Pesti, G M

    2017-09-01

    The objective of this experiment was to determine the maximum net returns digestible lysine (dLys) levels (MNRL) when maintaining the ideal amino acid ratio for starter diets of broilers raised sex separate or comingled (straight-run). A total of 3,240 Ross 708 chicks was separated by sex and placed in 90 pens by 2 rearing types: sex separate (36 males or 36 females) or straight-run (18 males + 18 females). Each rearing type was fed 6 starter diets (25 d) formulated to have dLys levels between 1.05 and 1.80%. A common grower diet with 1.02% of dLys was fed from 25 to 32 days. Body weight gain (BWG) and feed intake were assessed at 25 and 32 d for performance evaluation. Additionally, at 26 and 33 d, 4 birds per pen were sampled for carcass yield evaluation. Data were modeled using response surface methodology in order to estimate feed intake and whole carcass weight at 1,600 g live BW. Returns over feed cost were estimated for a 1.8-million-broiler complex of each rearing system under 9 feed/meat price scenarios. Results indicated that females needed more feed to reach market weight, followed by straight-run birds, and then males. At medium meat and feed prices, female birds had MNRL at 1.07% dLys, whereas straight-run and males had MNRL at 1.05%. As feed and meat prices increased, females had MNRL increased up to 1.15% dLys. Sex separation resulted in increased revenue under certain feed and meat prices, and before sex separation cost was deducted. When the sexing cost was subtracted from the returns, sex separation was not shown to be economically viable when targeting birds for light market BW. © 2017 Poultry Science Association Inc.

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

    International Nuclear Information System (INIS)

    Luckey, R.R.; Lobmeyer, D.H.; Burkhardt, D.J.

    1993-01-01

    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

  3. Pregnant women in Timis County, Romania are exposed primarily to low-level (<10 μg/L) arsenic through residential drinking water consumption

    OpenAIRE

    Neamtiu, Iulia; Bloom, Michael S.; Gati, Gabriel; Goessler, Walter; Surdu, Simona; Pop, Cristian; Braeuer, Simone; Fitzgerald, Edward F.; Baciu, Calin; Lupsa, Ioana Rodica; Anastasiu, Doru; Gurzau, Eugen

    2015-01-01

    Excessive arsenic content in drinking water poses health risks to millions of people worldwide. Inorganic arsenic (iAs) in groundwater exceeding the 10 μg/l maximum contaminant level (MCL) set by the World Health Organization (WHO) is characteristic for intermediate-depth aquifers over large areas of the Pannonian Basin in Central Europe. In western Romania, near the border with Hungary, Arad, Bihor, and Timis counties use drinking water coming partially or entirely from iAs contaminated aqui...

  4. PWR type reactor equipped with a primary circuit loop water level gauge

    International Nuclear Information System (INIS)

    Suzuki, Mitsuhiro.

    1990-01-01

    The time of lowering a water level to less than the position of high temperature side pipeway nozzle has been rather delayed because of the swelling of mixed water level due to heat generation of the reactor core. Further, there has been a certain restriction for the installation, maintenance and adjustment of a water level gauge since it is at a position under high radiation exposure. Then, a differential pressure type water level gauge with temperature compensation is disposed at a portion below a water level gauge of a pressurizer and between the steam generator exit plenum and the lower end of the loop seal. Further, a similar water level system is disposed to all of the loops of the primary circulation circuits. In a case that the amount of water contained in a reactor container should decreased upon occurrence of loss of coolant accidents caused by small rupture and stoppage of primary circuit pumps, lowering of the water level preceding to the lowering of the water level in the reactor core is detected to ensure the amount of water. Since they are disposed to all of the loops and ensure the excess margin, reliability for the detection of the amount of contained water can be improved by averaging time for the data of the water level and averaging the entire systems, even when there are vibrations in the fluid or pressure in the primary circuit. (N.H.)

  5. Multi variate regression model of the water level and production rate time series of the geothermal reservoir Waiwera (New Zealand)

    Science.gov (United States)

    Kühn, Michael; Schöne, Tim

    2017-04-01

    Water management tools are essential to ensure the conservation of natural resources. The geothermal hot water reservoir below the village of Waiwera, on the Northern Island of New Zealand is used commercially since 1863. The continuous production of 50 °C hot geothermal water, to supply hotels and spas, has a negative impact on the reservoir. Until the year 1969 from all wells drilled the warm water flow was artesian. Due to overproduction the water needs to be pumped up nowadays. Further, within the years 1975 to 1976 the warm water seeps on the beach of Waiwera ran dry. In order to protect the reservoir and the historical and tourist site in the early 1980s a water management plan was deployed. The "Auckland Council" established guidelines to enable a sustainable management of the resource [1]. The management plan demands that the water level in the official and appropriate observation well of the council is 0.5 m above sea level throughout the year in average. Almost four decades of data (since 1978 until today) are now available [2]. For a sustainable water management, it is necessary to be able to forecast the water level as a function of the production rates in the production wells. The best predictions are provided by a multivariate regression model of the water level and production rate time series, which takes into account the production rates of individual wells. It is based on the inversely proportional relationship between the independent variable (production rate) and the dependent variable (measured water level). In production scenarios, a maximum total production rate of approx. 1,100 m3 / day is determined in order to comply with the guidelines of the "Auckland Council". [1] Kühn M., Stöfen H. (2005) A reactive flow model of the geothermal reservoir Waiwera, New Zealand. Hydrogeology Journal 13, 606-626, doi: 10.1007/s10040-004-0377-6 [2] Kühn M., Altmannsberger C. (2016) Assessment of data driven and process based water management tools for

  6. Investigation of the Effect of Water Removal from Wells Surrounding Parishan Lake on Groundwater and Surface Water Levels

    International Nuclear Information System (INIS)

    Shafiei, M.; Raini Sarjaz, M.; Fazloli, R.; Gholami Sefidkouhi, M. A.

    2017-01-01

    In recent decades the human impacts on global warming and, its consequences, climate change, stirred up earth ecosystems balance and has created many problems all over the world. Unauthorized underground water removal, especially in arid and semi-arid regions of Iran, along with recent decade drought occurrences significantly lowered underground and surface water levels. To investigate the impacts of water removal from surrounding wells in Parishan Lake water level, during 1996 to 2009 interval, 8 buffer layers surrounding the lake were mapped in ArcGIS 9.3 environment. Each buffer layer wells and their total annual discharges were determined. Using SPSS 16 software, the regression equations between wells water levels and water discharges were computed. By employing Thiessen function and creating Thiessen network (TIN) around observation wells, decline of groundwater levels was evaluated. Finally regression equations between wells discharges and groundwater level declines were created. The findings showed that there are highly significant correlations (p ≤ 0.01), in all buffer layers, between water levels and wells discharges. Investigation of the observation wells surrounding lake showed that severe groundwater level declines has been started since the beginning of the first decade of the 21st century. Using satellite images in ArcGIS 9.3 environment it was confirmed that lake’s area has been reduced significantly. In conclusion, it is obvious that human interferences on lake’s natural ecosystem by digging unauthorized wells and removing underground water more than annual recharges significantly impacted surface and groundwater levels.

  7. BWR [boiling water reactor] core criticality versus water level during an ATWS [anticipated transient without scram] event

    International Nuclear Information System (INIS)

    Sehgal, B.R.; Peng, C.M.; Maly, J.

    1988-01-01

    The BWR [boiling water reactor] emergency procedures guidelines recommend management of core water level to reduce the power generated during an anticipated transient without scram (ATWS) event. BWR power level variation has traditionally been calculated in the system codes using a 1-D [one-dimensional] 2-group neutron kinetics model to determine criticality. This methodology used also for calculating criticality of the partially covered BWR cores has, however, never been validated against data. In this paper, the power level versus water level issues in an ATWS severe accident are introduced and the accuracy of the traditional methodology is investigated by comparing with measured data. It is found that the 1-D 2-group treatment is not adequate for accurate predictions of criticality and therefore the system power level for the water level variations that may be encountered in a prototypical ATWS severe accident. It is believed that the current predictions for power level may be too high

  8. REDUCING ARSENIC LEVELS IN DRINKING WATER DURING IRON REMOVAL PROCESSES

    Science.gov (United States)

    The presentation provides an overview of iron removal technology for the removal of arsenic from drinking water. The presentation is divided into several topic topics: Arsenic Chemistry, Treatment Selection, Treatment Options, Case Studies and Iron Removal Processes. Each topic i...

  9. NOAA NOS SOS, EXPERIMENTAL, 1853-present, Water Level

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA NOS SOS server is part of the IOOS DIF SOS Project. The stations in this dataset have water surface height above a reference datum. *These services are for...

  10. Level of Faecal Coliform Contamination of Drinking Water Sources ...

    African Journals Online (AJOL)

    2018-03-01

    Mar 1, 2018 ... ... of Drinking Water Sources and Its Associated Risk Factors in Rural Settings of North Gondar ... of Environmental & Occupational. Health & Safety, Gondar, Ethiopia. 2University of Gondar .... technicians. All sampling bottles ...

  11. Effect of electrolyzed reduced water on malondialdehyde levels and ...

    African Journals Online (AJOL)

    Purpose: To evaluate the effects of electrolyzed reduced water (ERW) on .... dehydrated and cleared with alcohol. ... assay tubes were incubated at a temperature of ... oxygen-dependent and oxygen-independent .... Oxidative Medicine and.

  12. 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

  13. Well-Construction, Water-Level, and Water-Quality Data for Ground-Water Monitoring Wells for the J4 Hydrogeologic Study, Arnold Air Force Base, Tennessee

    National Research Council Canada - National Science Library

    Haugh, Connor J

    1996-01-01

    ...) in Coffee County, Tennessee. The wells ranged from 28 to 289 feet deep and were installed to provide information on subsurface lithology, aquifer characteristics, ground-water levels, and ground-water quality...

  14. Radioactivity levels in surface water of lakes around Izmir / Turkey

    International Nuclear Information System (INIS)

    Doyurum, S.; Turkozu, D. A.; Aslani, M. A. A.; Aytas, S.; Eral, M.; Kaygun, A. K.

    2006-01-01

    Radioactivity presents in surface continental waters is mainly due to the presence of radioactive elements in the earth's crust, other artificial radionuclides have appeared due to such human activities as nuclear power plants, nuclear weapons testing and manufacture and use of radioactive sources It is well known that natural radionuclides can be effective as tracers for the different processes controlling the distribution of elements among dissolved and particulate phases in aquatic systems. The detection of high radionuclide concentrations was proposed as a public health problem in several areas and consequently studies into the risks of radionuclides were started in the 2000s. Especially, these radioactive substances in groundwater are an unwanted and involuntary risk factor from natural sources, not artificial sources. These radioactive substances include uranium, radon found in uranium series, and other radioactive substances such as radium and gross alpha. Uranium present in rock, soil, and natural materials, and is found in small quantities in air, water, and food that people always contact. In this project, lake water samples were collected from three lakes around Izmir-Turkey. In surface lake water samples, pH, mV and conductivity values were measured and alkaline content was determined titrimetrically. The uranium concentrations in the lake water samples were measured using uranium analyzer. The radioactivity concentrations related to gross radium isotopes, gross-? and gross-? activities in the surface lake water were determined. The correlation among some parameters for water samples and concentrations of uranium, activity concentration of gross radium isotopes, gross alpha and gross beta radioactivity are also discussed

  15. Precursory changes in well water level prior to the March, 2000 eruption of Usu Volcano, Japan

    Science.gov (United States)

    Shibata, Tomo; Akita, Fujio

    The height of water levels in two wells located near Usu volcano, Japan, changed in a systematic fashion for several months prior to the eruption of Usu volcano on 31 March 2000. In one well, water-level decrease relative to normal levels was first observed at the beginning of October 1999. The decreasing water-level is postulated to result from groundwater flow into cracks widened by intruding magma during dike formation. From the beginning of January 2000, the rate of decrease became higher. During this time, the water level of the second well increased by 0.05 m and then gradually decreased. The water-level changes are consistent with volumetric expansion of magma inside the magma chamber, followed by intrusion of magma into the fracture system associated with widening of cracks. We conclude that water-level observations can provide information that may potentially be used to predict further volcanic eruptions.

  16. A model study of the effect of climate and sea-level change on the evolution of the Antarctic Ice Sheet from the Last Glacial Maximum to 2100

    NARCIS (Netherlands)

    Maris, M. N. A.; Van Wessem, J. M.; Van De Berg, W. J.; De Boer, B.; Oerlemans, J.

    2014-01-01

    Due to a scarcity of observations and its long memory of uncertain past climate, the Antarctic Ice Sheet remains a largely unknown factor in the prediction of global sea level change. As the history of the ice sheet plays a key role in its future evolution, in this study we model the Antarctic Ice

  17. Treatment of low level waste water by reverse osmosis

    International Nuclear Information System (INIS)

    Li Kaijun; Zhang Chuanzhi; Xue Qinhua; Liu Meijun

    1987-11-01

    A Study on the removal of certain radioactive elements Such as 141 Ce, 51 Cr 134 Cu, 106 Ru and 131 I by Reverse Osmosis and the effect of surface activity agent on property of membrance are described in this paper. RO model is carried out to examine the treatment of actual reactor waste water and radioactive laundry waste water. The removal efficiency of total β is 98%. Three preprocessing (cloth pocket filtrator, hivefiltrator and zone) and membrane cleaning methods (acid, ozone and spongeball) are also investigated

  18. Natural radiation level in drinking water in Homs city

    International Nuclear Information System (INIS)

    Shweikani, R.; Raja, Gh.

    2008-11-01

    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)

  19. Water-level and recoverable water in storage changes, High Plains aquifer, predevelopment to 2015 and 2013–15

    Science.gov (United States)

    McGuire, Virginia L.

    2017-06-01

    The High Plains aquifer underlies 111.8 million acres (about 175,000 square miles) in parts of eight States—Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. Water-level declines began in parts of the High Plains aquifer soon after the beginning of substantial irrigation with groundwater in the aquifer area (about 1950). This report presents water-level changes and change in recoverable water in storage in the High Plains aquifer from predevelopment (about 1950) to 2015 and from 2013 to 2015.The methods to calculate area-weighted, average water-level changes; change in recoverable water in storage; and total recoverable water in storage used geospatial data layers organized as rasters with a cell size of 500 meters by 500 meters, which is an area of about 62 acres. Raster datasets of water-level changes are provided for other uses.Water-level changes from predevelopment to 2015, by well, ranged from a rise of 84 feet to a decline of 234 feet. Water-level changes from 2013 to 2015, by well, ranged from a rise of 24 feet to a decline of 33 feet. The area-weighted, average water-level changes in the aquifer were an overall decline of 15.8 feet from predevelopment to 2015 and a decline of 0.6 feet from 2013 to 2015. Total recoverable water in storage in the aquifer in 2015 was about 2.91 billion acre-feet, which was a decline of about 273.2 million acre-feet since predevelopment and a decline of 10.7 million acre-feet from 2013 to 2015.

  20. 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...

  1. Dual-Level Material and Psychological Assessment of Urban Water Security in a Water-Stressed Coastal City

    Directory of Open Access Journals (Sweden)

    Yajing Huang

    2015-04-01

    Full Text Available The acceleration of urbanization and industrialization has been gradually aggravating water security issues, such as water shortages, water pollution, and flooding or drought disasters and so on. Water security issues have become a great challenge to urban sustainable development. In this context, we proposed a dual-level material and psychological assessment method to assess urban water security. Psychological security coefficients were introduced in this method to combine material security and residents’ security feelings. A typical water-stressed coastal city in China (Dalian was chosen as a case study. The water security status of Dalian from 2010 to 2012 was analysed dynamically. The results indicated that the Dalian water security statuses from 2010 to 2012 were basically secure, but solutions to improve water security status and solve water resource problems are still required. This dual-level material and psychological assessment for urban water security has improved conventional material assessment through the introduction of psychological security coefficients, which can benefit decision-making for urban water planning, management and protection.

  2. levels of heavy metals in gubi dam water bauchi, nigeria

    African Journals Online (AJOL)

    Ada

    copper and lead were always highest in the suspended materials which indicate the dominant role played by ... essential. However, at high concentrations, these trace metals become toxic (Nurnberg, 1982). Heavy metals in .... mobilization of cobalt minerals into the dam. .... Interaction between sediments and fresh water ...

  3. Determination of lead at nanogram level in water samples by ...

    African Journals Online (AJOL)

    A novel method of chemistry applicable to the determination of trace lead in water samples based on the resonance light scattering (RLS) technique has been developed. In dilute phosphoric acid medium, in the presence of a large excess of I-, Pb(II) can form [PbI4]2-, which further reacts with tetrabutyl ammonium bromide ...

  4. in_focus - Water: Local-level Management | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... in the availability and supply of fresh water are truly a matter of life and death, and ... David B. Brooks is a specialist in natural resources who works with the ... of Energy Conservation, Dr Brooks worked for 6 years with Friends of the Earth ...

  5. Effect of Different Levels of Molasses Fed Through Drinking Water ...

    African Journals Online (AJOL)

    An experiment was conducted to evaluate the effect of molasses fed through drinking water on growth and economic performance of broiler chickens. One hundred and sixty unsexed day old chicks of Anak strain were used. They were divided into four treatment groups with each group having four replicates of ten birds per ...

  6. 77 FR 25721 - Small Entity Compliance Guide: Bottled Water: Quality Standard: Establishing an Allowable Level...

    Science.gov (United States)

    2012-05-01

    ...] Small Entity Compliance Guide: Bottled Water: Quality Standard: Establishing an Allowable Level for di(2... ``Bottled Water: Quality Standard: Establishing an Allowable Level for di(2- ethylhexyl)phthalate--Small... an allowable level for di(2- ethylhexyl)phthalate (DEHP). This final rule is effective April 16, 2012...

  7. 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

    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

  8. Does pan diameter influence carbon monoxide levels during heating of water to boiling point with a camping stove?

    Science.gov (United States)

    Leigh-Smith, Simon; Stevenson, Richard; Watt, Martin; Watt, Ian; McFadyen, Angus; Grant, Stan

    2004-01-01

    To determine whether pan diameter influences carbon monoxide (CO) concentration during heating of water to boiling point with a camping stove. The hypothesis was that increasing pan diameter increases CO concentration because of greater flame dispersal and a larger flame. This was a randomized, prospective study. A Coleman Dual Fuel 533 stove was used to heat pans of water to boiling point, with CO concentration monitored every 30 seconds for 5 minutes. The stove was inside a partially ventilated 200-L cardboard box model that was inside an environmental chamber at -6 degrees C. Water temperature, water volume, and flame characteristics were all standardized. Ten trials were performed for each of 2 pan diameters (base diameters of 165 mm [small] and 220 mm [large]). There was a significant difference (P = .002) between the pans for CO levels at each measurement interval from 60 seconds onward. These differences were markedly larger after 90 seconds, with a mean difference of 185 ppm (95% CI 115, 276 ppm) for all the results from 120 seconds onwards. This study has shown that there is significantly higher CO production with a large-diameter pan compared with a small-diameter pan. These findings were evident by using a camping stove to heat water to boiling point when a maximum blue flame was present throughout. Thus, in enclosed environments it is recommended that small-diameter pans be used in an attempt to prevent high CO levels.

  9. Ready-to-eat vegetables production with low-level water chlorination. An evaluation of water quality, and of its impact on end products.

    Science.gov (United States)

    D'Acunzo, Francesca; Del Cimmuto, Angela; Marinelli, Lucia; Aurigemma, Caterina; De Giusti, Maria

    2012-01-01

    We evaluated the microbiological impact of low-level chlorination (1 ppm free chlorine) on the production of ready-to-eat (RTE) vegetables by monitoring the microbiological quality of irrigation and processing water in two production plants over a 4-season period, as well as the microbiological quality of unprocessed vegetables and RTE product. Water samples were also characterized in terms of some chemical and physico-chemical parameters of relevance in chlorination management. Both producers use water with maximum 1 ppm free chlorine for vegetables rinsing, while the two processes differ by the number of washing cycles. Salmonella spp and Campylobacter spp were detected once in two different irrigation water samples out of nine from one producer. No pathogens were found in the vegetable samples. As expected, the procedure encompassing more washing cycles performed slightly better in terms of total mesophilic count (TMC) when comparing unprocessed and RTE vegetables of the same batch. However, data suggest that low-level chlorination may be insufficient in preventing microbial build-up in the washing equipment and/or batch-to batch cross-contamination.

  10. Drinking cholera: salinity levels and palatability of drinking water in coastal Bangladesh.

    Science.gov (United States)

    Grant, Stephen Lawrence; Tamason, Charlotte Crim; Hoque, Bilqis Amin; Jensen, Peter Kjaer Mackie

    2015-04-01

    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. 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. 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. 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. © 2015 John Wiley & Sons Ltd.

  11. Southern Dobrogea coastal potable water sources and Upper Quaternary Black Sea level changes

    Science.gov (United States)

    Caraivan, Glicherie; Stefanescu, Diana

    2013-04-01

    Maximum (MIS 2), the shoreline retreats eastwards, reaching the 100-120 m isobaths. In these conditions, the surface drainage base level was very low. Phreatic nape closely followed the river valleys dynamics. Mean depth aquifer discharged on the inner shelf , where Sarmatian limestones outcrop. The deep aquifer discharge was restricted by the Capidava- Ovidiu Fault to the north-east and by a presumed seawards longitudinal Fault. This process enabled the migration of the prehistoric human communities, from Asia to Europe, who established settlements on the newly created alluvial plain on the western Black Sea shelf. The Holocene Transgression (MIS 1) determined a sea level rise up to the modern one, and probably higher. Under the pressure of these environmental changes, the Neolithic settlements slowly retreated upstream. During the Greek colonization, the rising sea level caused the salinisation of the previous drinking water phreatic sources. In these conditions, in the Roman Age, a new hydraulic infrastructure had to be developed, using aqueducts for available inland water delivery.

  12. A study of full width at half maximum (FWHM) according to the filter's cut off level in SPECT camera

    Energy Technology Data Exchange (ETDEWEB)

    Park, Soung Ock [Dongnam Health College, Suwon (Korea, Republic of); Kwon, Soo Il [Kyonggi University, Suwon (Korea, Republic of)

    2003-06-15

    Filtering is necessary to reduce statistical noise and to increase image quality in SPECT images. Noises controlled by low-pass filter designed to suppress high spatial frequency in SPECT image. Most SPECT filter function control the degree of high frequency suppression by choosing a cut off frequency. The location of cut off frequency determines the affect image noise and spatial resolution. If select the low cut off frequency, its provide good noise suppression but insufficient image quantity and high cut off frequencies increase the image resolution but insufficient noise suppression. The purpose of this study was to determines the optimum cut off level with comparison of FWHM according to cut off level in each filters-Band-limited, Sheep-logan, Sheep-logan Hanning, Generalized Hamming, Low pass cosine, Parazen and Butterworth filter in SPECT camera. We recorded image along the X, Y, Z-axis with {sup 99m}TcO{sub 4} point source and measured FWHM by use profile curve. We find averaged length is 9.16 mm {approx} 18.14 mm of FWHM in X, Y, and Z-axis, and Band-limited and Generalized Hamming filters measures 9.16 mm at 0.7 cycle/pixel cut off frequency.

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

    International Nuclear Information System (INIS)

    Deng Chen; Zhang Qinshun

    2008-01-01

    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)

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

    International Nuclear Information System (INIS)

    Qian Hong; Ye Jianhua; Qian Fei; Li Chao

    2010-01-01

    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)

  15. Towards risk-based drought management in the Netherlands: making water supply levels transparent to water users

    Science.gov (United States)

    Maat Judith, Ter; Marjolein, Mens; Vuren Saskia, Van; der Vat Marnix, Van

    2016-04-01

    To prepare the Dutch Delta for future droughts and water scarcity, a nation-wide 4-year project, called Delta Programme, assessed the impact of climate change and socio-economic development, and explored strategies to deal with these impacts. The Programme initiated a joint approach to water supply management with stakeholders and developed a national adaptation plan that is able to adapt to future uncertain conditions. The adaptation plan consists of a set of preferred policy pathways - sequences of possible actions and measures through time - to achieve targets while responding in a flexible manner to uncertain developments over time, allowing room to respond to new opportunities and insights. With regard to fresh water allocation, the Delta Programme stated that supplying water of sufficient quality is a shared responsibility that requires cohesive efforts among users in the main and regional water system. The national and local authorities and water users involved agreed that the water availability and, where relevant, the water quality should be as transparent and predictable as possible under normal, dry and extremely dry conditions. They therefore introduced the concept of "water supply service levels", which should describe water availability and quality that can be delivered with a certain return period, for all regions and all relevant water users in the Netherlands. The service levels form an addition to the present policy and should be decided on by 2021. At present water allocation during periods of (expected) water shortage occurs according to a prearranged ranking system (a water hierarchy scheme based on a list of priorities), if water availability drops below a critical low level. The aim is to have supply levels available that are based on the probability of occurrence and economic impact of water shortage, and that are transparent for all water users in the regional water systems and the main water system. As part of the European project

  16. 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

    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.

  17. Ground-water levels in aquifers used for residential supply, Campton Township, Kane County, Illinois

    Science.gov (United States)

    Kay, Robert T.; Kraske, Kurt A.

    1996-01-01

    The U.S. Geological Survey, in cooperation with the Campton Township Board of Trustees, measured water levels in the aquifers used for residential supply in Campton Township, Kane County, Illinois. Aquifers used for residential supply are the shallow and deep aquifers in the glacial drift, composed of unconsolidated sand and gravels; the Alexandrian-Maquoketa aquifer, composed of dolomite and shale of the Alexandrian Series and the Maquoketa Group; the Galena-Platteville aquifer, composed of dolomite of the Platteville and Galena Groups; and the Ancell aquifer, composed of sandstones of the Glenwood Formation and the St. Peter Sanstone. Water-level altitudes in the shallow drift aquifers generally follow surface topography. Analysis of water-level data does not clearly indicate overutilization of these aquifers. Water-level altitudes in the deep drift aquifers decrease from west to east. Comparison of historical depth to water measurements with current (1995) measurements indicates large decreases in water levels in some areas. The deep drift aquifers may be overutilized at these locations. Water-level altitudes in the Alexandrian-Maquoketa aquifer generally decrease from west to east. The potentiometric surface of the aquifer follows the bedrock-surface topography in some locations. Localized low water-level altitudes and large decreases in water levels indicate the Alexandrian-Maquoketa aquifer is overutilized in several areas. Water-level altitudes in the wells finished in the Galena- Platteville aquifer vary by more than 300 feet. Large decreases in water levels in wells finished in the Galena-Platteville aquifer indicate the Galena-Platteville and Alexandrian-Maquoketa aquifers are overutilized in the northern part of the township. Water-level altitudes in the wells finished in the Ancell aquifer are also highly variable. There is no indication that the Ancell aquifer is overutilized.

  18. Nonlinear Stochastic Models for Water Level Dynamics in Closed Lakes

    OpenAIRE

    Mishchenko, A.S.; Zelikin, M.I.; Zelikina, L.F.

    1995-01-01

    This paper presents the results of investigation of nonlinear mathematical models of the behavior of closed lakes using the example of the Caspian Sea. Forecasting the level of the Caspian Sea is crucial both for the economy of the region and for the region's environment. The Caspian Sea is a closed reservoir; it is well known that its level changes considerably due to a variety of factors including global climate change. A series of forecasts exists based on different methods and taking...

  19. Preliminary Assessment of Water Levels in Bedrock Wells in New Hampshire, 1984 to 2007

    Science.gov (United States)

    Ayotte, Joseph D.; Kernen, Brandon M.; Wunsch, David R.; Argue, Denise M.; Bennett, Derek S.; Mack, Thomas J.

    2010-01-01

    Analysis of nearly 60,000 reported values of static water level (SWL, as depth below land surface) in bedrock wells in New Hampshire, aggregated on a yearly basis, showed an apparent deepening of SWL of about 13 ft (4 m) over the period 1984–2007. Water-level data were one-time measurements at each well and were analyzed, in part, to determine if they were suitable for analysis of trends in groundwater levels across the state. Other well characteristics, however, also have been changing over time, such as total well depth, casing length, the length of casing in bedrock, and to some extent, well yield. Analyses indicated that many of the well construction variables are significantly correlated; the apparent declines in water levels may have been caused by some of these factors. Information on changes in water use for the period was not available, although water use may be an important factor affecting water levels.

  20. Water level affects availability of optimal feeding habitats for threatened migratory waterbirds

    DEFF Research Database (Denmark)

    Aharon-Rotman, Yaara; McEvoy, John; Zheng Zhaoju

    2017-01-01

    within the lake. Changing the natural hydrological system will affect waterbirds dependent on water level changes for food availability and accessibility. We tracked two goose species with different feeding behaviors (greater white-fronted geese Anser albifrons [grazing species] and swan geese Anser......Extensive ephemeral wetlands at Poyang Lake, created by dramatic seasonal changes in water level, constitute the main wintering site for migratory Anatidae in China. Reductions in wetland area during the last 15years have led to proposals to build a Poyang Dam to retain high winter water levels...... cygnoides [tuber-feeding species]) during two winters with contrasting water levels (continuous recession in 2015; sustained high water in 2016, similar to those predicted post-Poyang Dam), investigating the effects of water level change on their habitat selection based on vegetation and elevation. In 2015...

  1. The effects of low level chlorination and chlorine dioxide on biofouling control in a once-through service water system

    International Nuclear Information System (INIS)

    Garrett, W.E. Jr.; Laylor, M.M.

    1995-01-01

    Continuous chlorination has been successfully used for the control of Corbicula at a nuclear power plant located on the Chattahoochee River in southeastern Alabama, since 1986. The purpose of this study was to investigate further minimization of chlorine usage and determine if chlorine dioxide is a feasible alternative. Four continuous biocide treatments were evaluated for macro and microfouling control effectiveness, operational feasibility, and environmental acceptability. One semi-continuous chlorination treatment was also evaluated for macrofouling control effectiveness. Higher treatment residuals were possible with chlorine dioxide than with chlorination due to the river discharge limitations. At the levels tested, continuous chlorine dioxide was significantly more effective in providing both macro and microfouling control. Semi-continuous chlorination was just as effective as continuous chlorination for controlling macrofouling. The Corbicula treatment programs that were tested should all provide sufficient control for zebra mussels. Chlorine dioxide was not as cost effective as chlorination for providing macrofouling control. The semi-continuous treatment save 50% on chemical usage and will allow for the simultaneous treatment of two service water systems. Chlorite levels produced during the chlorine dioxide treatments were found to be environmentally acceptable. Levels of trihalomethanes in the chlorinated service water were less than the maximum levels allowed in drinking water

  2. Return momentum effect on reactor coolant water level distribution during mid-loop conditions

    International Nuclear Information System (INIS)

    Seo, Jae Kwang; Yang, Jae Young; Park, Goon Cherl

    2001-01-01

    An accurate prediction of the Reactor Coolant System( RCS) water level is of importance in the determination of the allowable operating range to ensure safety during mid-loop operations. However, complex hydrualic phenomena induced by the Shutdown Cooling System (SCS) return momentum causes different water levels from those in the loop where the water level indicators are located. This was apparently observed at the pre-core cold hydro test of the Younggwang Nuclear Unit 3 (YGN 3) in Korea. In this study, in order to analytically understand the effect of the SCS return momentum on the RCS water level distribution, a model using a one-dimensional momentum and energy conservation for cylindrical channel, hydraulic jump in operating cold leg, water level build-up at the Reactor Vessel (RV) inlet nozzle, Bernoulli constant in downcomer region, and total water volume conservation has been developed. The model predicts the RCS water levels at various RCS locations during the mid-loop conditions and the calculation results were compared with the test data. The analysis shows that the hydraulic jump in the operating cold legs, in conjuction with the pressure drop throughout the RCS, is the main cause creating the water level differences at various RCS locations. The prediction results provide good explanations for the test data and show the significant effect of the SCS return momentum on the RCS water levels

  3. Do Amplitudes of Water Level Fluctuations Affect the Growth and Community Structure of Submerged Macrophytes?

    Science.gov (United States)

    Wang, Mo-Zhu; Liu, Zheng-Yuan; Luo, Fang-Li; Lei, Guang-Chun; Li, Hong-Li

    2016-01-01

    Submerged macrophytes are subjected to potential mechanical stresses associated with fluctuating water levels in natural conditions. However, few experimental studies have been conducted to further understand the effects of water level fluctuating amplitude on submerged macrophyte species and their assemblages or communities. We designed a controlled experiment to investigate the responses of three submerged macrophyte species (Hydrilla verticillata, Ceratophyllum demersum and Elodea nuttallii) and their combinations in communities to three amplitudes (static, ± 30 cm, ± 60 cm) of water level fluctuations. Results showed that water level fluctuating amplitude had little effects on the community performance and the three tested species responded differently. H. verticillata exhibited more growth in static water and it was negatively affected by either of the water level fluctuations amplitude, however, growth parameters of H. verticillata in two fluctuating water level treatments (i.e., ± 30 cm, ± 60 cm) were not significantly different. On the other hand, the growth of C. demersum was not significantly correlated with different amplitude treatments. However, it became more abundant when water levels fluctuated. E. nuttallii was inhibited by the two fluctuating water level treatments, and was less in growth parameters compared to the other species especially in water level fluctuating conditions. The inherent differences in the adaptive capabilities of the tested species indicate that C. demersum or other species with similar responses may be dominant species to restore submerged macrophyte communities with great fluctuating water levels. Otherwise, H. verticillata, E. nuttallii or other species with similar responses could be considered for constructing the community in static water conditions.

  4. Do Amplitudes of Water Level Fluctuations Affect the Growth and Community Structure of Submerged Macrophytes?

    Directory of Open Access Journals (Sweden)

    Mo-Zhu Wang

    Full Text Available Submerged macrophytes are subjected to potential mechanical stresses associated with fluctuating water levels in natural conditions. However, few experimental studies have been conducted to further understand the effects of water level fluctuating amplitude on submerged macrophyte species and their assemblages or communities. We designed a controlled experiment to investigate the responses of three submerged macrophyte species (Hydrilla verticillata, Ceratophyllum demersum and Elodea nuttallii and their combinations in communities to three amplitudes (static, ± 30 cm, ± 60 cm of water level fluctuations. Results showed that water level fluctuating amplitude had little effects on the community performance and the three tested species responded differently. H. verticillata exhibited more growth in static water and it was negatively affected by either of the water level fluctuations amplitude, however, growth parameters of H. verticillata in two fluctuating water level treatments (i.e., ± 30 cm, ± 60 cm were not significantly different. On the other hand, the growth of C. demersum was not significantly correlated with different amplitude treatments. However, it became more abundant when water levels fluctuated. E. nuttallii was inhibited by the two fluctuating water level treatments, and was less in growth parameters compared to the other species especially in water level fluctuating conditions. The inherent differences in the adaptive capabilities of the tested species indicate that C. demersum or other species with similar responses may be dominant species to restore submerged macrophyte communities with great fluctuating water levels. Otherwise, H. verticillata, E. nuttallii or other species with similar responses could be considered for constructing the community in static water conditions.

  5. Do Amplitudes of Water Level Fluctuations Affect the Growth and Community Structure of Submerged Macrophytes?

    Science.gov (United States)

    Wang, Mo-Zhu; Liu, Zheng-Yuan; Luo, Fang-Li; Lei, Guang-Chun; Li, Hong-Li

    2016-01-01

    Submerged macrophytes are subjected to potential mechanical stresses associated with fluctuating water levels in natural conditions. However, few experimental studies have been conducted to further understand the effects of water level fluctuating amplitude on submerged macrophyte species and their assemblages or communities. We designed a controlled experiment to investigate the responses of three submerged macrophyte species (Hydrilla verticillata, Ceratophyllum demersum and Elodea nuttallii) and their combinations in communities to three amplitudes (static, ± 30 cm, ± 60 cm) of water level fluctuations. Results showed that water level fluctuating amplitude had little effects on the community performance and the three tested species responded differently. H. verticillata exhibited more growth in static water and it was negatively affected by either of the water level fluctuations amplitude, however, growth parameters of H. verticillata in two fluctuating water level treatments (i.e., ± 30 cm, ± 60 cm) were not significantly different. On the other hand, the growth of C. demersum was not significantly correlated with different amplitude treatments. However, it became more abundant when water levels fluctuated. E. nuttallii was inhibited by the two fluctuating water level treatments, and was less in growth parameters compared to the other species especially in water level fluctuating conditions. The inherent differences in the adaptive capabilities of the tested species indicate that C. demersum or other species with similar responses may be dominant species to restore submerged macrophyte communities with great fluctuating water levels. Otherwise, H. verticillata, E. nuttallii or other species with similar responses could be considered for constructing the community in static water conditions. PMID:26735689

  6. Fuzzy logic control of water level in advanced boiling water reactor

    International Nuclear Information System (INIS)

    Lin, Chaung; Lee, Chi-Szu; Raghavan, R.; Fahrner, D.M.

    1995-01-01

    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

  7. Approach to calculating upper bounds on maximum individual doses from the use of contaminated well water following a WIPP repository breach. Report EEG-9

    International Nuclear Information System (INIS)

    Spiegler, P.

    1981-09-01

    As part of the assessment of the potential radiological consequences of the proposed Waste Isolation Pilot Plant (WIPP), this report evaluates the post-closure radiation dose commitments associated with a possible breach event which involves dissolution of the repository by groundwaters and subsequent transport of the nuclear waste through an aquifer to a well assumed to exist at a point 3 miles downstream from the repository. The concentrations of uranium and plutonium isotopes at the well are based on the nuclear waste inventory presently proposed for WIPP and basic assumptions concerning the transport of waste as well as treatment to reduce the salinity of the water. The concentrations of U-233, Pu-239, and Pu-240, all radionuclides originally emplaced as waste in the repository, would exceed current EPA drinking water limits. The concentrations of U-234, U-235, and U-236, all decay products of plutonium isotopes originally emplaced as waste, would be well below current EPA drinking water limits. The 50-year dose commitments from one year of drinking treated water contaminated with U-233 or Pu-239 and Pu-240 were found to be comparable to a one-year dose from natural background. The 50-year dose commitments from one year of drinking milk would be no more than about 1/5 the dose obtained from ingestion of treated water. These doses are considered upper bounds because of several very conservative assumptions which are discussed in the report

  8. Comparison of 1972 and 1996 water levels in the Goleta central ground-water subbasin, Santa Barbara County, California

    Science.gov (United States)

    Kaehler, Charles A.; Pratt, David A.; Paybins, Katherine S.

    1997-01-01

    Ground-water levels for 1996 were compared with 1972 water levels to determine if a "drought buffer" currently exists. The drought buffer was defined previously, in a litigated settlement involving the Goleta Water District, as the 1972 water level in the Central ground-water subbasin. To make this deter mination, a network of 15 well sites was selected, water levels were measured monthly from April through December 1996, and the 1996 water-level data were compared with1972 data. The study was done in cooperation with the Goleta Water District. The 1972-1996 water-level-altitude changes for corresponding months of the comparison years were averaged for each network well. These averaged changes ranged from a rise of 9.4 ft for well 2N2 to a decline of 45.0 ft for well 8K8. The results of the comparison indicate a rise in water level at 1 site (well 2N2) and a decline at 14 sites. The mean of the 14 negative average values was a decline of 24.0 ft. The altitude of the bottom of well 2N2 was higher than the bottom altitudes at the other network sites, and this well is located a few feet from a fault that acts as a hydrologic barrier. The results of the water-level comparison for the Central subbasin were influenced to some unknown degree by the areal distribution of the set of wells selected for the network and the vertical dis tribution of the perforated intervals of the wells. For this reason, the mean water-level change--a decline of 21.8 ft--calculated from the averages of the month-to-month changes for the 15 network sites, should be used with caution. In addition, the number of usable individual monthly comparison measurements available for an individual site ranged from one to nine, and averaged six. Therefore, a weighted mean of the monthly averages was calculated on the basis of the number of comparison measurements available for each site. The weighted mean is a decline of 20.9 ft. All Central subbasin wells that were idle (that is, were not being pumped

  9. Levels of trace metals in water and sediment from Tyume River and ...

    African Journals Online (AJOL)

    Levels of trace metals (Cd, Pb, Co, Zn Cu and Ni) were determined in water and sediment ... mg/l) and Pb (0.021 ± 0.004 to 0.035 ± 0.001 mg/l) were found in the river water, ... Key words: trace metals, water, sediment, farmland, Tyume River

  10. Nitrate and ammonium levels of some water bodies and their ...

    African Journals Online (AJOL)

    The present study examined the nitrate (NO3-) and ammonium (NH4+) levels of Rivers Wouri and Dibamba and some streams that feed them. The interaction of NO3- and NH4+ with some soil properties was also investigated. It was necessitated by the usage of these rivers for livelihood, despite the deposition of discharges ...

  11. An integrated investigation of lake storage and water level changes in the Paiku Co basin, central Himalayas

    Science.gov (United States)

    Lei, Yanbin; Yao, Tandong; Yang, Kun; Bird, Broxton W.; Tian, Lide; Zhang, Xiaowen; Wang, Weicai; Xiang, Yang; Dai, Yufeng; Lazhu; Zhou, Jing; Wang, Lei

    2018-07-01

    Since the late 1990s, lakes in the southern Tibetan Plateau (TP) have shrunk considerably, which contrasts with the rapid expansion of lakes in the interior TP. Although these spatial trends have been well documented, the underlying hydroclimatic mechanisms are not well understood. Since 2013, we have carried out comprehensive water budget observations at Paiku Co, an alpine lake in the central Himalayas. In this study, we investigate water storage and lake level changes on seasonal to decadal time scales based on extensive in-situ measurements and satellite observations. Bathymetric surveys show that Paiku Co has a mean and maximum water depth of 41.1 m and 72.8 m, respectively, and its water storage was estimated to be 109.3 × 108 m3 in June 2016. On seasonal scale between 2013 and 2017, Paiku Co's lake level decreased slowly between January and May, increased considerably between June and September, and then decreased rapidly between October and January. On decadal time scale, Paiku Co's lake level decreased by 3.7 ± 0.3 m and water storage reduced by (10.2 ± 0.8) × 108 m3 between 1972 and 2015, accounting for 8.5% of the total water storage in 1972. This change is consistent with a trend towards drier conditions in the Himalaya region during the recent decades. In contrast, glacial lakes within Paiku Co's basin expanded rapidly, indicating that, unlike Paiku Co, glacial meltwater was sufficient to compensate the effect of the reduced precipitation.

  12. 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)

    Khawaja, H.A.; Khattak, I.

    2008-01-01

    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)

  13. Maximum Quantum Entropy Method

    OpenAIRE

    Sim, Jae-Hoon; Han, Myung Joon

    2018-01-01

    Maximum entropy method for analytic continuation is extended by introducing quantum relative entropy. This new method is formulated in terms of matrix-valued functions and therefore invariant under arbitrary unitary transformation of input matrix. As a result, the continuation of off-diagonal elements becomes straightforward. Without introducing any further ambiguity, the Bayesian probabilistic interpretation is maintained just as in the conventional maximum entropy method. The applications o...

  14. Maximum power demand cost

    International Nuclear Information System (INIS)

    Biondi, L.

    1998-01-01

    The charging for a service is a supplier's remuneration for the expenses incurred in providing it. There are currently two charges for electricity: consumption and maximum demand. While no problem arises about the former, the issue is more complicated for the latter and the analysis in this article tends to show that the annual charge for maximum demand arbitrarily discriminates among consumer groups, to the disadvantage of some [it

  15. Recent Changes in Land Water Storage and Its Contribution to Sea Level Variations

    Science.gov (United States)

    Wada, Yoshihide; Reager, John T.; Chao, Benjamin F.; Wang, Jida; Lo, Min-Hui; Song, Chunqiao; Li, Yuwen; Gardner, Alex S.

    2016-01-01

    Sea level rise is generally attributed to increased ocean heat content and increased rates glacier and ice melt. However, human transformations of Earth's surface have impacted water exchange between land, atmosphere, and ocean, ultimately affecting global sea level variations. Impoundment of water in reservoirs and artificial lakes has reduced the outflow of water to the sea, while river runoff has increased due to groundwater mining, wetland and endorheic lake storage losses, and deforestation. In addition, climate-driven changes in land water stores can have a large impact on global sea level variations over decadal timescales. Here, we review each component of negative and positive land water contribution separately in order to highlight and understand recent changes in land water contribution to sea level variations.

  16. The Water Footprint as an indicator of environmental sustainability in water use at the river basin level.

    Science.gov (United States)

    Pellicer-Martínez, Francisco; Martínez-Paz, José Miguel

    2016-11-15

    One of the main challenges in water management is to determine how the current water use can condition its availability to future generations and hence its sustainability. This study proposes the use of the Water Footprint (WF) indicator to assess the environmental sustainability in water resources management at the river basin level. The current study presents the methodology developed and applies it to a case study. The WF is a relatively new indicator that measures the total volume of freshwater that is used as a production factor. Its application is ever growing in the evaluation of water use in production processes. The calculation of the WF involves water resources (blue), precipitation stored in the soil (green) and pollution (grey). It provides a comprehensive assessment of the environmental sustainability of water use in a river basin. The methodology is based upon the simulation of the anthropised water cycle, which is conducted by combining a hydrological model and a decision support system. The methodology allows the assessment of the environmental sustainability of water management at different levels, and/or ex-ante analysis of how the decisions made in water planning process affect sustainability. The sustainability study was carried out in the Segura River Basin (SRB) in South-eastern Spain. The SRB is among the most complex basins in Europe, given its special peculiarities: competition for the use, overexploitation of aquifers, pollution, alternative sources, among others. The results indicate that blue water use is not sustainable due to the generalised overexploitation of aquifers. They also reveal that surface water pollution, which is not sustainable, is mainly caused by phosphate concentrations. The assessment of future scenarios reveals that these problems will worsen if no additional measures are implemented, and therefore the water management in the SRB is environmentally unsustainable in both the short- and medium-term. Copyright © 2016

  17. Investigation of natural radioactivity level of the waters in the tibet autonomous region

    International Nuclear Information System (INIS)

    Zhang Tianhua; Li Yankun; Yao Ke; Pan Chengchang

    1995-01-01

    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

  18. Investigation of natural radioactivity level of the waters in Inner Mongolia

    International Nuclear Information System (INIS)

    Du Xuelin; Li Wenyuan; Fu Su

    1993-01-01

    The authors reports the investigation results of natural radioactivity level in rivers, lakes, reservoirs, springs, wells and tap water in Inner Mongolia Autonomous Region. There were totally 326 samples collected from 178 measuring points. The results show that the radioactivity level of varied water bodies of the region was within normal natural background

  19. Investigation of natural radioactivity level of the waters in Guangxi Zhuangzu Autonomous Region

    International Nuclear Information System (INIS)

    Yang Mingshen; Ming Chuanbao; Dai Guozhi; Liang Runping; Chen Xiuyu; Yang Gang; Jin Mei

    1993-01-01

    This paper reports the investigation results of natural radioactivity level in river, lake reservoir, spring, well and tap water in Guangxi Zhuangzu Autonomous Region. There were totally 194 samples collected from 143 measuring points. The results show that the radioactivity level of varied water bodies of the region was within normal natural background

  20. Investigation of natural radioactivity level of the waters in the Ningxia Hui Autonomous Region

    International Nuclear Information System (INIS)

    Jing Yupei; Wang Li; Tian Yi; Ai Xianyuan; Liang Ningbu

    1995-01-01

    This paper reports the investigation results of natural radioactivity level in river, lake, reservoir, spring, well and tap water in the Ningxia Hui Autonomous Region. There were totally 117 samples collected from 84 measuring points. The results show that the radioactivity level of varied water bodies of the region was within normal natural background

  1. Observations and estimates of wave-driven water level extremes at the Marshall Islands

    Science.gov (United States)

    Merrifield, M. A.; Becker, J. M.; Ford, M.; Yao, Y.

    2014-10-01

    Wave-driven extreme water levels are examined for coastlines protected by fringing reefs using field observations obtained in the Republic of the Marshall Islands. The 2% exceedence water level near the shoreline due to waves is estimated empirically for the study sites from breaking wave height at the outer reef and by combining separate contributions from setup, sea and swell, and infragravity waves, which are estimated based on breaking wave height and water level over the reef flat. Although each component exhibits a tidal dependence, they sum to yield a 2% exceedence level that does not. A hindcast based on the breaking wave height parameterization is used to assess factors leading to flooding at Roi-Namur caused by an energetic swell event during December 2008. Extreme water levels similar to December 2008 are projected to increase significantly with rising sea level as more wave and tide events combine to exceed inundation threshold levels.

  2. Testing and use of radar water level sensors by the U.S. Geological Survey

    Science.gov (United States)

    Fulford, Janice M.

    2016-01-01

    The United States Geological Survey uses water-level (or stage) measurements to compute streamflow at over 8000 stream gaging stations located throughout the United States (waterwatch.usgs.gov, 2016). Streamflow (or discharge) is computed at five minute to hourly intervals from a relationship between water level and discharge that is uniquely determined for each station. The discharges are posted hourly to WaterWatch (waterwatch. usgs.gov) and are used by water managers to issue flood warnings and manage water supply and by other users of water information to make decisions. The accuracy of the water-level measurement is vital to the accuracy of the computed discharge. Because of the importance of water-level measurements, USGS has an accuracy policy of 0.02 ft or 0.2 percent of reading (whichever is larger) (Sauer and Turnipseed, 2010). Older technologies, such as float and shaft-encoder systems, bubbler systems and submersible pressure sensors, provide the needed accuracy but often require extensive construction to install and are prone to malfunctioning and damage from floating debris and sediment. No stilling wells or orifice lines need to be constructed for radar installations. During the last decade testing by the USGS Hydrologic Instrumentation Facility(HIF) found that radar water-level sensors can provide the needed accuracy for water-level measurements and because the sensor can be easily attached to bridges, reduce the construction required for installation. Additionally, the non-contact sensing of water level minimizes or eliminates damage and fouling from floating debris and sediment. This article is a brief summary of the testing efforts by the USGS HIF and field experiences with models of radar water-level sensors in streamflow measurement applications. Any use of trade names in this article is for descriptive purposes only and does not imply endorsement by the U.S. Government.

  3. Type GQS-1 high pressure steam manifold water level monitoring system

    International Nuclear Information System (INIS)

    Li Nianzu; Li Beicheng; Jia Shengming

    1993-10-01

    The GQS-1 high pressure steam manifold water level monitoring system is an advanced nuclear gauge that is suitable for on-line detecting and monitor in high pressure steam manifold water level. The physical variable of water level is transformed into electrical pulses by the nuclear sensor. A computer is equipped for data acquisition, analysis and processing and the results are displayed on a 14 inch color monitor. In addition, a 4 ∼ 20 mA output current is used for the recording and regulation of water level. The main application of this gauge is for on-line measurement of high pressure steam manifold water level in fossil-fired power plant and other industries

  4. Relations between vegetation and water level in groundwater dependent terrestrial ecosystems (GWDTEs)

    DEFF Research Database (Denmark)

    Munch Johansen, Ole; Andersen, Dagmar Kappel; Ejrnæs, Rasmus

    2018-01-01

    , management and conservation of fens are constrained by limited knowledge on the relations between vegetation and measurable hydrological conditions. This study investigates the relations between vegetation and water level dynamics in groundwater dependent wetlands in Denmark. A total of 35 wetland sites...... across Denmark were included in the study. The sites represent a continuum of wetlands with respect to vegetation and hydrological conditions. Water level was measured continuously using pressure transducers at each site. Metrics expressing different hydrological characteristics, such as mean water level...... and low and high water level periods, were calculated based on the water level time series. A complete plant species list was recorded in plots covering 78.5 m2 at each site. Community metrics such as total number of species and the number of bryophytes were generated from the species lists and Ellenberg...

  5. Projections of extreme water level events for atolls in the western Tropical Pacific

    Science.gov (United States)

    Merrifield, M. A.; Becker, J. M.; Ford, M.; Yao, Y.

    2014-12-01

    Conditions that lead to extreme water levels and coastal flooding are examined for atolls in the Republic of the Marshall Islands based on a recent field study of wave transformations over fringing reefs, tide gauge observations, and wave model hindcasts. Wave-driven water level extremes pose the largest threat to atoll shorelines, with coastal levels scaling as approximately one-third of the incident breaking wave height. The wave-driven coastal water level is partitioned into a mean setup, low frequency oscillations associated with cross-reef quasi-standing modes, and wind waves that reach the shore after undergoing high dissipation due to breaking and bottom friction. All three components depend on the water level over the reef; however, the sum of the components is independent of water level due to cancelling effects. Wave hindcasts suggest that wave-driven water level extremes capable of coastal flooding are infrequent events that require a peak wave event to coincide with mid- to high-tide conditions. Interannual and decadal variations in sea level do not change the frequency of these events appreciably. Future sea-level rise scenarios significantly increase the flooding threat associated with wave events, with a nearly exponential increase in flooding days per year as sea level exceeds 0.3 to 1.0 m above current levels.

  6. Urban stormwater - greywater management system for sustainable urban water management at sub-watershed level

    Science.gov (United States)

    Singh Arora, Amarpreet

    2017-11-01

    Urban water management involves urban water supply (import, treatment and distribution of water), urban wastewater management (collection, treatment and disposal of urban sewage) and urban storm water management. Declining groundwater tables, polluted and declining sources of water, water scarcity in urban areas, unsatisfactory urban water supply and sanitation situation, pollution of receiving water bodies (including the ground water), and urban floods have become the concerns and issues of sustainable urban water management. This paper proposes a model for urban stormwater and sewage management which addresses these concerns and issues of sustainable urban water management. This model proposes segregation of the sewage into black water and greywater, and urban sub-watershed level stormwater-greywater management systems. During dry weather this system will be handling only the greywater and making the latter available as reclaimed water for reuse in place of the fresh water supply. During wet weather, the system will be taking care of (collection and treatment) both the storm water and the greywater, and the excess of the treated water will be disposed off through groundwater recharging. Application of this model in the Patiala city, Punjab, INDIA for selected urban sub-watersheds has been tried. Information and background data required for the conceptualization and design of the sub-watershed level urban stormwater-greywater management system was collected and the system has been designed for one of the sub-watersheds in the Patiala city. In this paper, the model for sustainable urban water management and the design of the Sub-watershed level Urban Stormwater-Greywater Management System are described.

  7. Water level observations from Unmanned Aerial Vehicles for improving estimates of surface water-groundwater interaction

    DEFF Research Database (Denmark)

    Bandini, Filippo; Butts, Michael; Vammen Jacobsen, Torsten

    2017-01-01

    spatial resolution; ii) spatially continuous profiles along or across the water body; iii) flexible timing of sampling. A semi-synthetic study was conducted to analyse the value of the new UAV-borne datatype for improving hydrological models, in particular estimates of GW (Groundwater)- SW (Surface Water...

  8. Water level determination for transportation projects : mean high water manual, final report, November 2009.

    Science.gov (United States)

    2009-11-01

    To ensure proficient network management and safe usage of navigable waterways especially in waters that are : subject to tides, it is essential that the height of the water at various tidal phases be known. This knowledge is also : essential for prop...

  9. Effects of water level on three wetlands soil seed banks on the Tibetan Plateau.

    Directory of Open Access Journals (Sweden)

    Miaojun Ma

    Full Text Available BACKGROUND: Although the effect of water level on germination in soil seed banks has been documented in many ecosystems, the mechanism is not fully understood, and to date no empirical studies on this subject exist. Further, no work has been done on the effect of water level on seed banks of drying and saline-alkaline wetlands in alpine areas on the Tibetan Plateau. METHODOLOGY: We examined the effects of water level (0 cm, 5 cm and 10 cm on seed germination and seedling establishment from soil seed banks at 0-5 cm and 5-10 cm depths in typical, drying, and saline-alkaline wetlands. We also explore the potential role of soil seed bank in restoration of drying and saline-alkaline wetlands. PRINCIPAL FINDINGS: Species richness decreased with increase in water level, but there almost no change in seed density. A huge difference exists in species composition of the seed bank among different water levels in all three wetlands, especially between 0 cm and 5 cm and 0 cm and 10 cm. Similarity of species composition between seed bank and plant community was higher in 0 cm water level in drying wetland than in the other two wetlands. The similarity was much higher in 0 cm water level than in 5 cm and 10 cm water levels in all three wetlands. Species composition of the alpine wetland plant community changed significantly after drying and salinization, however, species composition of the seed bank was unchanged regardless of the environment change. CONCLUSIONS/SIGNIFICANCE: Water level greatly affects seed bank recruitment and plant community establishment. Further, different water levels in restored habitats are likely to determine its species composition of the plant community. The seed bank is important in restoration of degraded wetlands. Successful restoration of drying and salinization wetlands could depend on the seed bank.

  10. Density and viscosity study of nicotinic acid and nicotinamide in dilute aqueous solutions at and around the temperature of the maximum density of water

    International Nuclear Information System (INIS)

    Dhondge, Sudhakar S.; Dahasahasra, Prachi N.; Paliwal, Lalitmohan J.; Deshmukh, Dinesh W.

    2014-01-01

    Highlights: • Volumetric and transport behaviour of aqueous solutions of important vitamins are reported. • Various interactions of nicotinic acid and nicotinamide with water have been reported. • The temperature dependence of interactions between solute and solvent is discussed. • The study indicates that nicotinamide is more hydrated as compared to nicotinic acid. - Abstract: In the present study, we report experimental densities (ρ) and viscosities (η) of aqueous solutions of nicotinic acid and nicotinamide within the concentration range (0 to 0.1) mol · kg −1 at T = (275.15, 277.15 and 279.15) K. These parameters are then used to obtain thermodynamic and transport functions such as apparent molar volume of solute (V ϕ ), limiting apparent molar volume of solute (V ϕ 0 ), limiting apparent molar expansivity of solute (E ϕ 0 ), coefficient of thermal expansion (α ∗ ), Jones–Dole equation viscosity A, B and D coefficients, temperature derivative of B coefficient i.e. (dB/dT) and hydration number (n H ), etc. The activation parameters of viscous flow for the binary mixtures have been determined and discussed in terms of Eyring’s transition state theory. These significant parameters are helpful to study the structure promoting or destroying tendency of solute and various interactions present in (nicotinic acid + water) and (nicotinamide + water) binary mixtures

  11. On the predictability of high water level along the US East Coast: can the Florida Current measurement be an indicator for flooding caused by remote forcing?

    Science.gov (United States)

    Ezer, Tal; Atkinson, Larry P.

    2017-06-01

    Recent studies show that in addition to wind and air pressure effects, a significant portion of the variability of coastal sea level (CSL) along the US East Coast can be attributed to non-local factors such as variations in the Gulf Stream and the North Atlantic circulation; these variations can cause unpredictable coastal flooding. The Florida Current transport (FCT) measurement across the Florida Straits monitors those variations, and thus, the study evaluated the potential of using the FCT as an indicator for anomalously high water level along the coast. Hourly water level data from 12 tide gauge stations over 12 years are used to construct records of maximum daily water levels (MDWL) that are compared with the daily FCT data. An empirical mode decomposition (EMD) approach is used to divide the data into high-frequency modes (periods T anti-correlated with MDWL in high-frequency modes but positively correlated with MDWL in low-frequency modes. FCC on the other hand is always anti-correlated with MDWL for all frequency bands, and the high water signal lags behind FCC for almost all stations, thus providing a potential predictive skill (i.e., whenever a weakening trend is detected in the FCT, anomalously high water is expected along the coast over the next few days). The MDWL-FCT correlation in the high-frequency modes is maximum in the lower Mid-Atlantic Bight, suggesting influence from the meandering Gulf Stream after it separates from the coast. However, the correlation in low-frequency modes is maximum in the South Atlantic Bight, suggesting impact from variations in the wind pattern over subtropical regions. The middle-frequency and low-frequency modes of the FCT seem to provide the best predictor for medium to large flooding events; it is estimated that ˜10-25% of the sea level variability in those modes can be attributed to variations in the FCT. An example from Hurricane Joaquin (September-October, 2015) demonstrates how an offshore storm that never made

  12. Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model

    International Nuclear Information System (INIS)

    Tucci, P.

    2001-01-01

    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

  13. Predicted impacts of future water level decline on monitoring wells using a ground-water model of the Hanford Site

    International Nuclear Information System (INIS)

    Wurstner, S.K.; Freshley, M.D.

    1994-12-01

    A ground-water flow model was used to predict water level decline in selected wells in the operating areas (100, 200, 300, and 400 Areas) and the 600 Area. To predict future water levels, the unconfined aquifer system was stimulated with the two-dimensional version of a ground-water model of the Hanford Site, which is based on the Coupled Fluid, Energy, and Solute Transport (CFEST) Code in conjunction with the Geographic Information Systems (GIS) software package. The model was developed using the assumption that artificial recharge to the unconfined aquifer system from Site operations was much greater than any natural recharge from precipitation or from the basalt aquifers below. However, artificial recharge is presently decreasing and projected to decrease even more in the future. Wells currently used for monitoring at the Hanford Site are beginning to go dry or are difficult to sample, and as the water table declines over the next 5 to 10 years, a larger number of wells is expected to be impacted. The water levels predicted by the ground-water model were compared with monitoring well completion intervals to determine which wells will become dry in the future. Predictions of wells that will go dry within the next 5 years have less uncertainty than predictions for wells that will become dry within 5 to 10 years. Each prediction is an estimate based on assumed future Hanford Site operating conditions and model assumptions

  14. Interpretation of changes in water level accompanying fault creep and implications for earthquake prediction.

    Science.gov (United States)

    Wesson, R.L.

    1981-01-01

    Quantitative calculations for the effect of a fault creep event on observations of changes in water level in wells provide an approach to the tectonic interpretation of these phenomena. For the pore pressure field associated with an idealized creep event having an exponential displacement versus time curve, an analytic expression has been obtained in terms of exponential-integral functions. The pore pressure versus time curves for observation points near the fault are pulselike; a sharp pressure increase (or decrease, depending on the direction of propagation) is followed by more gradual decay to the normal level after the creep event. The time function of the water level change may be obtained by applying the filter - derived by A.G.Johnson and others to determine the influence of atmospheric pressure on water level - to the analytic pore pressure versus time curves. The resulting water level curves show a fairly rapid increase (or decrease) and then a very gradual return to normal. The results of this analytic model do not reproduce the steplike changes in water level observed by Johnson and others. If the procedure used to obtain the water level from the pore pressure is correct, these results suggest that steplike changes in water level are not produced by smoothly propagating creep events but by creep events that propagate discontinuously, by changes in the bulk properties of the region around the well, or by some other mechanism.-Author

  15. Storm Surge Reconstruction and Return Water Level Estimation in Southeast Asia for the 20th Century

    NARCIS (Netherlands)

    Cid, Alba; Wahl, Thomas; Chambers, Don P.; Muis, Sanne

    2018-01-01

    We present a methodology to reconstruct the daily maximum storm surge levels, obtained from tide gauges, based on the surrounding atmospheric conditions from an atmospheric reanalysis (20th Century Reanalysis-20CR). Tide gauge records in Southeast Asia are relatively short, so this area is often

  16. Origin of elevated water levels encountered in Pahute Mesa emplacement boreholes: Preliminary investigations

    International Nuclear Information System (INIS)

    Brikowski, T.; Chapman, J.; Lyles, B.; Hokett, S.

    1993-11-01

    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

  17. A linear bi-level multi-objective program for optimal allocation of water resources.

    Directory of Open Access Journals (Sweden)

    Ijaz Ahmad

    Full Text Available This paper presents a simple bi-level multi-objective linear program (BLMOLP with a hierarchical structure consisting of reservoir managers and several water use sectors under a multi-objective framework for the optimal allocation of limited water resources. Being the upper level decision makers (i.e., leader in the hierarchy, the reservoir managers control the water allocation system and tend to create a balance among the competing water users thereby maximizing the total benefits to the society. On the other hand, the competing water use sectors, being the lower level decision makers (i.e., followers in the hierarchy, aim only to maximize individual sectoral benefits. This multi-objective bi-level optimization problem can be solved using the simultaneous compromise constraint (SICCON technique which creates a compromise between upper and lower level decision makers (DMs, and transforms the multi-objective function into a single decision-making problem. The bi-level model developed in this study has been applied to the Swat River basin in Pakistan for the optimal allocation of water resources among competing water demand sectors and different scenarios have been developed. The application of the model in this study shows that the SICCON is a simple, applicable and feasible approach to solve the BLMOLP problem. Finally, the comparisons of the model results show that the optimization model is practical and efficient when it is applied to different conditions with priorities assigned to various water users.

  18. Comparisons of maximum deformation and failure forces at the implant–abutment interface of titanium implants between titanium-alloy and zirconia abutments with two levels of marginal bone loss

    Science.gov (United States)

    2013-01-01

    Background Zirconia materials are known for their optimal aesthetics, but they are brittle, and concerns remain about whether their mechanical properties are sufficient for withstanding the forces exerted in the oral cavity. Therefore, this study compared the maximum deformation and failure forces of titanium implants between titanium-alloy and zirconia abutments under oblique compressive forces in the presence of two levels of marginal bone loss. Methods Twenty implants were divided into Groups A and B, with simulated bone losses of 3.0 and 1.5 mm, respectively. Groups A and B were also each divided into two subgroups with five implants each: (1) titanium implants connected to titanium-alloy abutments and (2) titanium implants connected to zirconia abutments. The maximum deformation and failure forces of each sample was determined using a universal testing machine. The data were analyzed using the nonparametric Mann–Whitney test. Results The mean maximum deformation and failure forces obtained the subgroups were as follows: A1 (simulated bone loss of 3.0 mm, titanium-alloy abutment) = 540.6 N and 656.9 N, respectively; A2 (simulated bone loss of 3.0 mm, zirconia abutment) = 531.8 N and 852.7 N; B1 (simulated bone loss of 1.5 mm, titanium-alloy abutment) = 1070.9 N and 1260.2 N; and B2 (simulated bone loss of 1.5 mm, zirconia abutment) = 907.3 N and 1182.8 N. The maximum deformation force differed significantly between Groups B1 and B2 but not between Groups A1 and A2. The failure force did not differ between Groups A1 and A2 or between Groups B1 and B2. The maximum deformation and failure forces differed significantly between Groups A1 and B1 and between Groups A2 and B2. Conclusions Based on this experimental study, the maximum deformation and failure forces are lower for implants with a marginal bone loss of 3.0 mm than of 1.5 mm. Zirconia abutments can withstand physiological occlusal forces applied in the anterior region. PMID

  19. [Modern problems of maintenance of hygienic safety of drinking water consumption at the regional level].

    Science.gov (United States)

    Tulakin, A V; Tsyplakova, G V; Ampleeva, G P; Kozyreva, O N; Pivneva, O S; Trukhina, G M

    Problems of hygienic reliability of the drinking water use in regions of the Russian Federation are observed in the article. The optimization of the water use was shown must be based on the bearing in mind of regional peculiarities of the shaping of water quality of groundwater and surface sources of the water use, taking into account of the effectiveness of regional water protection programs, programs for water treatment, coordination of the activity of economic entities and oversight bodies in the management of water quality on the basis of socio-hygienic monitoring. Regional problems requiring hygienic justification and accounting, include such issues as complex hydrological, hydrogeological, climatic and geographical conditions, pronouncement of the severity of anthropogenic pollution of sources of water supply, natural conditions of the shaping of water quality, efficiency of the water treatment. There is need in the improvement of the problems of the water quality monitoring, including with the use of computer technology, which allows to realize regional hygienic monitoring and spatial-temporal analysis of the water quality, to model the water quality management, to predict conditions of the water use by population in regions taking into account peculiarities of the current health situation. In the article there is shown the practicability of the so-called complex concept of multiple barriers suggesting the combined use of chemical oxidation and physical methods of the preparation of drinking water. It is required the further development of legislation for the protection of water bodies from pollution with the bigging up the status of sanitary protection zones; timely revision of the regulatory framework, establishing sanitary-epidemiological requirements to potable water and drinking water supply. The problem of the provision of the population with safe drinking water requires complex solution within the framework of the implementation of target programs

  20. Numerical evaluation of the water saturation in a high level radioactive waste disposal

    International Nuclear Information System (INIS)

    Benet, L.V.; Bouillet, Ch.; Tulita, C.; Wendling, J.

    2010-01-01

    Document available in extended abstract form only. This work is a contribution of the ANDRA's program of numerical simulations of the evolution in time of hydrogeological flows in a radioactive waste repository in deep clay formations. This study aims at evaluating the water contact areas with steel for corrosion modeling in a High-Level radioactive waste disposal, from the building to the total saturation, more than 100 000 years later [HSPA6b]. Energy release by radioactive spent fuel and thermal expansion of the interstitial water is taken into account in the models. Thermal transfers in the porous media and free convection in the gaps (Navier-Stokes equations) are computed with a linear Finite Element scheme. The mass transfers in the porous media are solved with a P0-P1 Mixed Finite Element method (Richard's equations during exploitation and two phases flow equations after the closure). All numerical simulations are performed with the Cast3M code (http://wwwcast3m. cea.fr/). During the exploitation, the H-L radioactive waste storage cell is not supposed to be hermetically closed. The pressure in the storage cell remains atmospheric and mass transfers towards the main gallery are possible. So a seepage boundary condition is used on excavation surface in order to provide evolution in time of saturation limit along the storage cell. For each cell of the boundary mesh: - No water flux is imposed in contact with unsaturated media. - Atmospheric pressure is imposed in contact with saturated media. A relative humidity of 50% is imposed for the atmosphere in the gallery. Vapour diffusive flux is implemented in Richard's equations with a suction pressure formula according to Kelvin law. Temperature impact on vapour flux is neglected. Vapour diffusive flux is significant in the concrete wall of gallery due to the ventilation. The free convection steady state in the gap is solved at different times of the thermal transient to evaluate location of

  1. Impact of water-level changes to aquatic vegetation in small oligotrophic lakes

    Directory of Open Access Journals (Sweden)

    Egert VANDEL

    2016-06-01

    Full Text Available This study demonstrates the effect of drastic water-level changes to the aquatic vegetation in three small oligotrophic lakes situated in Kurtna Kame Field in north-eastern Estonia. The area holds around 40 lakes in 30 km2 of which 18 lakes are under protection as Natura Habitat lakes (Natura 2000 network. The area is under a strong human impact as it is surrounded by oil shale mines, sand quarry, peat harvesting field etc. The most severe impact comes from the groundwater intake established in 1972 in the vicinity of three studied lakes. The exploitation of groundwater led to drastic water-level drops. In 1980s the water-level drops were measured to be up to 3 to 4 meters compared to the levels of 1946. Lake Martiska and Lake Kuradijärv were severely affected and only 29% and 45% of lake area respectively and 21% of initial volume remained. Both lakes were described as oligotrophic lakes before severe human impact and held characteristic macrophytes such as Isoëtes lacustris L., Sparganium angustifolium Michx and Lobelia dortmanna L. As the water level declined the lakes lost their rare characteristic species and can now be described more as a meso- or even eutrophic lakes. When the volume of groundwater abstraction decreased in the 1990s the water levels started to recover but did not reach the natural levels of pre-industrialized era. Also the vegetation did not show any signs of recovery. In 2012 the pumping rates increased again causing a new rapid decline in water levels which almost exceed the previous minimum levels. The water-level monitoring alongside with the macrophyte monitoring data gives us a good case study on how the long term abrupt water-level changes can affect the aquatic vegetation

  2. Virtual Crop Water Export Analysis: The Case of Greece at River Basin District Level

    Directory of Open Access Journals (Sweden)

    Nikolaos Mellios

    2018-05-01

    Full Text Available An analysis of virtual crop water export through international trade is conducted for Greece, downscaled to the River Basin District (RBD level, in order to identify critical “hotspots” of localized water shortage in the country. A computable general equilibrium model (MAGNET was used to obtain the export shares of crops and associated irrigation water was calculated for all major crops in Greece. A distinction between virtual crop water locally consumed and traded internationally was made for all Greek RBDs. Cotton was identified as a large water consumer and virtual water exporter, while GR08 and GR10 were identified as the RBDs mostly impacted. The value of virtual water exported was calculated for all crop types and fruits and vegetables were identified as the crop most beneficial, since they consume the least water for the obtained value.

  3. DATA QUALIFICATION REPORT: WATER-LEVEL DATA FROM THE NYE COUNTY EARLY WARNING DRILLING PROGRAM

    Energy Technology Data Exchange (ETDEWEB)

    F. H. Dove, P. Sanchez, and L. Saraka

    2000-04-21

    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.

  4. DATA QUALIFICATION REPORT: WATER-LEVEL DATA FROM THE NYE COUNTY EARLY WARNING DRILLING PROGRAM

    International Nuclear Information System (INIS)

    F. H. Dove, P. Sanchez, and L. Saraka

    2000-01-01

    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

  5. Maximum likely scale estimation

    DEFF Research Database (Denmark)

    Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo

    2005-01-01

    A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and/or ...

  6. Robust Maximum Association Estimators

    NARCIS (Netherlands)

    A. Alfons (Andreas); C. Croux (Christophe); P. Filzmoser (Peter)

    2017-01-01

    textabstractThe maximum association between two multivariate variables X and Y is defined as the maximal value that a bivariate association measure between one-dimensional projections αX and αY can attain. Taking the Pearson correlation as projection index results in the first canonical correlation

  7. Gauging leaf-level contributions to landscape-level water loss within a Western US dryland fores

    Science.gov (United States)

    Murphy, P.; Potts, D. L.; Minor, R. L.; Hamerlynck, E. P.; Sutter, L., Jr.; Barron-Gafford, G.

    2017-12-01

    Western US forests represent a large constituent of the North American water and carbon cycles, yet the primary controls on water loss from these ecosystems remains unknown. In dryland forests, such as those found in the Southwestern US, water availability is key to ecosystem function, and the timing and magnitude of water loss can have lasting effects on the health of these communities. One poorly defined part of the water balance in these forests is the partitioning of evapotranspiration (ET) into evaporation (E; blue flow) to transpiration (T; green flow). A study of water fluxes at multiple scales in a semiarid montane forest in Southern Arizona speaks to the partitioning of these two water flows. Within the footprint of an eddy covariance system, which estimates ecosystem ET, we have examined the impacts of variation in climate, species makeup, and topographic position on E and T. This was done using leaf-level measures of T, pedon-scale measures of E, and whole-tree water loss by way of sap flux sensors. Where available, we have examined E, T, and ET fluxes across multiple seasons and years of highly variable precipitation records. Understanding the partitioning of ET is crucial, considering that projected changes to dryland ecosystems include longer periods of drought separated by heavier precipitation events. At a moment when potential impacts of changing climate on dryland structure and function are poorly understood, a stronger comprehension of these blue and green water flows is necessary to forecast the productivity of Western US forests into the future.

  8. Interannual water-level fluctuations and the vegetation of prairie potholes: Potential impacts of climate change

    Science.gov (United States)

    van der Valk, Arnold; Mushet, David M.

    2016-01-01

    Mean water depth and range of interannual water-level fluctuations over wet-dry cycles in precipitation are major drivers of vegetation zone formation in North American prairie potholes. We used harmonic hydrological models, which require only mean interannual water depth and amplitude of water-level fluctuations over a wet–dry cycle, to examine how the vegetation zones in a pothole would respond to small changes in water depth and/or amplitude of water-level fluctuations. Field data from wetlands in Saskatchewan, North Dakota, and South Dakota were used to parameterize harmonic models for four pothole classes. Six scenarios in which small negative or positive changes in either mean water depth, amplitude of interannual fluctuations, or both, were modeled to predict if they would affect the number of zones in each wetland class. The results indicated that, in some cases, even small changes in mean water depth when coupled with a small change in amplitude of water-level fluctuations can shift a prairie pothole wetland from one class to another. Our results suggest that climate change could alter the relative proportion of different wetland classes in the prairie pothole region.

  9. Subseasonal to Seasonal Predictions of U.S. West Coast High Water Levels

    Science.gov (United States)

    Khouakhi, A.; Villarini, G.; Zhang, W.; Slater, L. J.

    2017-12-01

    Extreme sea levels pose a significant threat to coastal communities, ecosystems, and assets, as they are conducive to coastal flooding, coastal erosion and inland salt-water intrusion. As sea levels continue to rise, these sea level extremes - including occasional minor coastal flooding experienced during high tide (nuisance floods) - are of concern. Extreme sea levels are increasing at many locations around the globe and have been attributed largely to rising mean sea levels associated with intra-seasonal to interannual climate processes such as the El Niño-Southern Oscillation (ENSO). Here, intra-seasonal to seasonal probabilistic forecasts of high water levels are computed at the Toke Point tide gage station on the US west coast. We first identify the main climate drivers that are responsible for high water levels and examine their predictability using General Circulation Models (GCMs) from the North American Multi-Model Ensemble (NMME). These drivers are then used to develop a probabilistic framework for the seasonal forecasting of high water levels. We focus on the climate controls on the frequency of high water levels using the number of exceedances above the 99.5th percentile and above the nuisance flood level established by the National Weather Service. Our findings indicate good forecast skill at the shortest lead time, with the skill that decreases as we increase the lead time. In general, these models aptly capture the year-to-year variability in the observational records.

  10. The status of pesticide pollution in surface waters (rivers and lakes) of Greece. Part I. Review on occurrence and levels

    International Nuclear Information System (INIS)

    Konstantinou, Ioannis K.; Hela, Dimitra G.; Albanis, Triantafyllos A.

    2006-01-01

    This review evaluates and summarizes the results of long-term research projects, monitoring programs and published papers concerning the pollution of surface waters (rivers and lakes) of Greece by pesticides. Pesticide classes mostly detected involve herbicides used extensively in corn, cotton and rice production, organophosphorus insecticides as well as the banned organochlorines insecticides due to their persistence in the aquatic environment. The compounds most frequently detected were atrazine, simazine, alachlor, metolachlor and trifluralin of the herbicides, diazinon, parathion methyl of the insecticides and lindane, endosulfan and aldrin of the organochlorine pesticides. Rivers were found to be more polluted than lakes. The detected concentrations of most pesticides follow a seasonal variation, with maximum values occurring during the late spring and summer period followed by a decrease during winter. Nationwide, in many cases the reported concentrations ranged in low ppb levels. However, elevated concentrations were recorded in areas of high pesticide use and intense agricultural practices. Generally, similar trends and levels of pesticides were found in Greek rivers compared to pesticide contamination in other European rivers. Monitoring of the Greek water resources for pesticide residues must continue, especially in agricultural regions, because the nationwide patterns of pesticide use are constantly changing. Moreover, emphasis should be placed on degradation products not sufficiently studied so far. - Information on pesticide pollution of surface waters in Greece is reviewed

  11. The effect of water level in a prey-predator interactions: A nonlinear analysis study

    International Nuclear Information System (INIS)

    Chiboub Fellah, N.; Bouguima, S.M.; Moussaoui, A.

    2012-01-01

    Highlights: ► A new model describing the interaction between predator and prey in Parloup Lake. ► Existence of periodic solution is proved. ► Seasonal variation in water level is an important factor for persitence. - Abstract: Water level may influence local community dynamics. We examine how seasonal variations in water level affect the outcome of prey-predator interactions in Parloup Lake in the south of France. We propose a new model to describe the annual cycle of persistence by using continuation theorem of coincidence degree.

  12. Use of inexpensive pressure transducers for measuring water levels in wells

    Science.gov (United States)

    Keeland, B.D.; Dowd, J.F.; Hardegree, W.S.

    1997-01-01

    Frequent measurement of below ground water levels at multiple locations is an important component of many wetland ecosystem studies. These measurements, however, are usually time consuming, labor intensive, and expensive. This paper describes a water-level sensor that is inexpensive and easy to construct. The sensor is placed below the expected low water level in a shallow well and, when connected to a datalogger, uses a pressure transducer to detect groundwater or surface water elevations. Details of pressure transducer theory, sensor construction, calibration, and examples of field installations are presented. Although the transducers must be individually calibrated, the sensors have a linear response to changing water levels (r2 ??? .999). Measurement errors resulting from temperature fluctuations are shown to be about 4 cm over a 35??C temperature range, but are minimal when the sensors are installed in groundwater wells where temperatures are less variable. Greater accuracy may be obtained by incorporating water temperature data into the initial calibration (0.14 cm error over a 35??C temperature range). Examples of the utility of these sensors in studies of groundwater/surface water interactions and the effects of water level fluctuations on tree growth are provided. ?? 1997 Kluwer Academic Publishers.

  13. Miniaturized Water Flow and Level Monitoring System for Flood Disaster Early Warning

    Science.gov (United States)

    Ifedapo Abdullahi, Salami; Hadi Habaebi, Mohamed; Surya Gunawan, Teddy; Rafiqul Islam, MD

    2017-11-01

    This study presents the performance of a prototype miniaturised water flow and water level monitoring sensor designed towards supporting flood disaster early warning systems. The design involved selection of sensors, coding to control the system mechanism, and automatic data logging and storage. During the design phase, the apparatus was constructed where all the components were assembled using locally sourced items. Subsequently, under controlled laboratory environment, the system was tested by running water through the inlet during which the flow rate and rising water levels are automatically recorded and stored in a database via Microsoft Excel using Coolterm software. The system is simulated such that the water level readings measured in centimeters is output in meters using a multiplicative of 10. A total number of 80 readings were analyzed to evaluate the performance of the system. The result shows that the system is sensitive to water level rise and yielded accurate measurement of water level. But, the flow rate fluctuates due to the manual water supply that produced inconsistent flow. It was also observed that the flow sensor has a duty cycle of 50% of operating time under normal condition which implies that the performance of the flow sensor is optimal.

  14. Preliminary assessment of the impact of fluctuating water levels on northern pike in Reindeer Lake

    International Nuclear Information System (INIS)

    Chen, M.

    1993-03-01

    Reindeer Lake in north eastern Saskatchewan regulates water levels for the Island Falls hydroelectric power plant. Since inception of the Whitesand Dam on the lake, there have been concerns that fluctuating water levels could be adversely impacting the habitat and population of northern pike in the lake. The extent of water level fluctuations during the pike spawning period of Reindeer Lake and its effect on spawning success was investigated. Since construction of the Whitesand Dam in 1942 Reindeer Lake water levels have averaged ca 1.71 m higher than had the dam not existed, creating ca 430 km 2 of new surface area. Much of this area is shallow water and prone to growth of aquatic vegetation, which is suitable spawning and nursery habitat for northern pike. Annual and periodic water level fluctuations of Reindeer Lake have been higher than under natural conditions. During northern pike spawning and nursing periods, water levels in the lake have generally increased, in 60 out of 64 y. It is concluded that operation of the dam has not caused any direct negative impacts on the northern pike habitat in the lake. 2 refs., 4 figs., 4 tabs

  15. Pulsating potentiometric titration technique for assay of dissolved oxygen in water at trace level.

    Science.gov (United States)

    Sahoo, P; Ananthanarayanan, R; Malathi, N; Rajiniganth, M P; Murali, N; Swaminathan, P

    2010-06-11

    A simple but high performance potentiometric titration technique using pulsating sensors has been developed for assay of dissolved oxygen (DO) in water samples down to 10.0 microg L(-1) levels. The technique involves Winkler titration chemistry, commonly used for determination of dissolved oxygen in water at mg L(-1) levels, with modification in methodology for accurate detection of end point even at 10.0 microg L(-1) levels DO present in the sample. An indigenously built sampling cum pretreatment vessel has been deployed for collection and chemical fixing of dissolved oxygen in water samples from flowing water line without exposure to air. A potentiometric titration facility using pulsating sensors developed in-house is used to carry out titration. The power of the titration technique has been realised in estimation of very dilute solution of iodine equivalent to 10 microg L(-1) O(2). Finally, several water samples containing dissolved oxygen from mg L(-1) to microg L(-1) levels were successfully analysed with excellent reproducibility using this new technique. The precision in measurement of DO in water at 10 microg L(-1) O(2) level is 0.14 (n=5), RSD: 1.4%. Probably for the first time a potentiometric titration technique has been successfully deployed for assay of dissolved oxygen in water samples at 10 microg L(-1) levels. Copyright 2010 Elsevier B.V. All rights reserved.

  16. Pulsating potentiometric titration technique for assay of dissolved oxygen in water at trace level

    International Nuclear Information System (INIS)

    Sahoo, P.; Ananthanarayanan, R.; Malathi, N.; Rajiniganth, M.P.; Murali, N.; Swaminathan, P.

    2010-01-01

    A simple but high performance potentiometric titration technique using pulsating sensors has been developed for assay of dissolved oxygen (DO) in water samples down to 10.0 μg L -1 levels. The technique involves Winkler titration chemistry, commonly used for determination of dissolved oxygen in water at mg L -1 levels, with modification in methodology for accurate detection of end point even at 10.0 μg L -1 levels DO present in the sample. An indigenously built sampling cum pretreatment vessel has been deployed for collection and chemical fixing of dissolved oxygen in water samples from flowing water line without exposure to air. A potentiometric titration facility using pulsating sensors developed in-house is used to carry out titration. The power of the titration technique has been realised in estimation of very dilute solution of iodine equivalent to 10 μg L -1 O 2 . Finally, several water samples containing dissolved oxygen from mg L -1 to μg L -1 levels were successfully analysed with excellent reproducibility using this new technique. The precision in measurement of DO in water at 10 μg L -1 O 2 level is 0.14 (n = 5), RSD: 1.4%. Probably for the first time a potentiometric titration technique has been successfully deployed for assay of dissolved oxygen in water samples at 10 μg L -1 levels.

  17. Carbon isotope fractionation during diamond growth in depleted peridotite: Counterintuitive insights from modelling water-maximum CHO fluids as multi-component systems

    Science.gov (United States)

    Stachel, T.; Chacko, T.; Luth, R. W.

    2017-09-01

    Because of the inability of depleted cratonic peridotites to effectively buffer oxygen fugacities when infiltrated by CHO or carbonatitic fluids, it has been proposed recently (Luth and Stachel, 2014) that diamond formation in peridotites typically does not occur by rock-buffered redox reactions as previously thought but by an oxygen-conserving reaction in which minor coexisting CH4 and CO2 components in a water-rich fluid react to form diamond (CO2 + CH4 = 2C + 2H2O). In such fluid-buffered systems, carbon isotope fractionation during diamond precipitation occurs in the presence of two dominant fluid carbon species. Carbon isotope modelling of diamond precipitation from mixed CH4- and CO2-bearing fluids reveals unexpected fundamental differences relative to diamond crystallization from a single carbon fluid species: (1) irrespective of which carbon fluid species (CH4 or CO2) is dominant in the initial fluid, diamond formation is invariably associated with progressive minor (diamond in 13C as crystallization proceeds. This is in contrast to diamond precipitation by rock-buffered redox processes from a fluid containing only a single carbon species, which can result in either progressive 13C enrichment (CO2 or carbonate fluids) or 13C depletion (CH4 fluids) in the diamond. (2) Fluid speciation is the key factor controlling diamond δ13 C values; as XCO2 (XCO2 = CO2/[CO2 + CH4]) in the initial fluid increases from 0.1 to 0.9 (corresponding to an increase in fO2 of 0.8 log units), the carbon isotope composition of the first-precipitated diamond decreases by 3.7‰. The tight mode in δ13C of - 5 ± 1 ‰ for diamonds worldwide places strict constraints on the dominant range of XCO2 in water-rich fluids responsible for diamond formation. Specifically, precipitation of diamonds with δ13C values in the range -4 to -6‰ from mantle-derived fluids with an average δ13C value of -5‰ (derived from evidence not related to diamonds) requires that diamond-forming fluids were

  18. Development of capacitive sensor for automatically measuring tumbler water level with FEA simulation.

    Science.gov (United States)

    Wei, Qun; Kim, Mi-Jung; Lee, Jong-Ha

    2018-01-01

    Drinking water has several advantages that have already been established, such as improving blood circulation, reducing acid in the stomach, etc. However, due to people not noticing the amount of water they consume every time they drink, most people drink less water than the recommended daily allowance. In this paper, a capacitive sensor for developing an automatic tumbler to measure water level is proposed. Different than in previous studies, the proposed capacitive sensor was separated into two sets: the main sensor for measuring the water level in the tumbler, and the reference sensor for measuring the incremental level unit. In order to confirm the feasibility of the proposed idea, and to optimize the shape of the sensor, a 3D model of the capacitive sensor with the tumbler was designed and subjected to Finite Element Analysis (FEA) simulation. According to the simulation results, the electrodes were made of copper and assembled in a tumbler manufactured by a 3D printer. The tumbler was filled with water and was subjected to experiments in order to assess the sensor's performance. The comparison of experimental results to the simulation results shows that the measured capacitance value of the capacitive sensor changed linearly as the water level varied. This proves that the proposed sensor can accurately measure the water level in the tumbler. Additionally, by use of the curve fitting method, a compensation algorithm was found to match the actual level with the measured level. The experimental results proved that the proposed capacitive sensor is able to measure the actual water level in the tumbler accurately. A digital control part with micro-processor will be designed and fixed on the bottom of the tumbler for developing a smart tumbler.

  19. Monitoring Vertical Crustal Deformation and Gravity Variations during Water Level Changes at the Three Gorges Reservoir

    Directory of Open Access Journals (Sweden)

    WANG Wei

    2017-06-01

    Full Text Available Monitoring vertical crustal deformation and gravity changes during water level changes at the Three Gorges reservoir is important for the safe operation of the Three Gorges Dam and for the monitoring and prevention of a regional geological disaster. In this study, we determined vertical crustal deformation and gravity changes during water level variations of the Three Gorges reservoir from direct calculations and actual measurements and a comprehensive solution. We used water areas extracted image data from the ZY-3 satellite and water level data to calculate gravity changes and vertical crustal deformation caused by every 5 m change in the water level due to storage and drainage of the Three Gorges reservoir from 145 m to 175 m. The vertical crustal deformation was up to 30 mm. The location of gravity change above 20 μ Gal(1 Gal=10-2 m/s2 was less than 2 km from the centerline of the Yangtze River. The CORS ES13 in Badong, near the reservoir, measured the vertical crustal deformation during water level changes. Because of the small number of CORS and gravity stations in the Three Gorges reservoir area, monitoring deformation and gravity related to changes in the Three Gorges reservoir water level cannot be closely followed. Using 26 CORS and some of the gravity stations in the Three Gorges area and based on loading deformation and the spherical harmonic analysis method, an integrated solution of vertical deformation and gravity variations during water level changes of the reservoir was determined, which is consistent with the actual CORS monitoring results. By comparison, we found that an integrated solution based on a CORS network can effectively enhance the capability of monitoring vertical crustal deformation and gravity changes during water level variations of the reservoir.

  20. Simulation of the effects of rainfall and groundwater use on historical lake water levels, groundwater levels, and spring flows in central Florida

    Science.gov (United States)

    O'Reilly, Andrew M.; Roehl, Edwin A.; Conrads, Paul; Daamen, Ruby C.; Petkewich, Matthew D.

    2014-01-01

    The urbanization of central Florida has progressed substantially in recent decades, and the total population in Lake, Orange, Osceola, Polk, and Seminole Counties more than quadrupled from 1960 to 2010. The Floridan aquifer system is the primary source of water for potable, industrial, and agricultural purposes in central Florida. Despite increases in groundwater withdrawals to meet the demand of population growth, recharge derived by infiltration of rainfall in the well-drained karst terrain of central Florida is the largest component of the long-term water balance of the Floridan aquifer system. To complement existing physics-based groundwater flow models, artificial neural networks and other data-mining techniques were used to simulate historical lake water level, groundwater level, and spring flow at sites throughout the area. Historical data were examined using descriptive statistics, cluster analysis, and other exploratory analysis techniques to assess their suitability for more intensive data-mining analysis. Linear trend analyses of meteorological data collected by the National Oceanic and Atmospheric Administration at 21 sites indicate 67 percent of sites exhibited upward trends in air temperature over at least a 45-year period of record, whereas 76 percent exhibited downward trends in rainfall over at least a 95-year period of record. Likewise, linear trend analyses of hydrologic response data, which have varied periods of record ranging in length from 10 to 79 years, indicate that water levels in lakes (307 sites) were about evenly split between upward and downward trends, whereas water levels in 69 percent of wells (out of 455 sites) and flows in 68 percent of springs (out of 19 sites) exhibited downward trends. Total groundwater use in the study area increased from about 250 million gallons per day (Mgal/d) in 1958 to about 590 Mgal/d in 1980 and remained relatively stable from 1981 to 2008, with a minimum of 559 Mgal/d in 1994 and a maximum of 773

  1. Further European initiatives and regulations concerning radiation protection: drinking water guideline, maximum permissible contamination in food products and feeding stuff; Weitere europaeische Initiativen und Regelungen im Strahlenschutz. Trinkwasserrichtlinie, maximal zulaessige Kontaminationswerte in Nahrungs- und Futtermitteln

    Energy Technology Data Exchange (ETDEWEB)

    Mundigl, Stefan [Europaeische Kommission, Generaldirektion Energie, Luxemburg (Luxembourg). Abt. D3 - Strahlenschutz, EUFO 4150

    2013-07-01

    The radiation protection community has observed intensively the development of basic safety standards concerning protection against hazards of ionizing radiation. The new core part of the European radiation protection legislation is complemented by several specialized regulations relevant for radiation protection. Besides the existing regulations in the field of emergency protection the European Commission initiated a drinking water guideline that will be published in the near future. Furthermore the European commission approved a revised regulation concerning the maximum permissible contamination limits for food products and feeding stuff in case of a future nuclear accident. Together with the new radiation protection basic standards a new complete, coherent and modernized European regulation package will be accomplished.

  2. Observations and a linear model of water level in an interconnected inlet-bay system

    Science.gov (United States)

    Aretxabaleta, Alfredo; Ganju, Neil K.; Butman, Bradford; Signell, Richard

    2017-01-01

    A system of barrier islands and back-barrier bays occurs along southern Long Island, New York, and in many coastal areas worldwide. Characterizing the bay physical response to water level fluctuations is needed to understand flooding during extreme events and evaluate their relation to geomorphological changes. Offshore sea level is one of the main drivers of water level fluctuations in semienclosed back-barrier bays. We analyzed observed water levels (October 2007 to November 2015) and developed analytical models to better understand bay water level along southern Long Island. An increase (∼0.02 m change in 0.17 m amplitude) in the dominant M2 tidal amplitude (containing the largest fraction of the variability) was observed in Great South Bay during mid-2014. The observed changes in both tidal amplitude and bay water level transfer from offshore were related to the dredging of nearby inlets and possibly the changing size of a breach across Fire Island caused by Hurricane Sandy (after December 2012). The bay response was independent of the magnitude of the fluctuations (e.g., storms) at a specific frequency. An analytical model that incorporates bay and inlet dimensions reproduced the observed transfer function in Great South Bay and surrounding areas. The model predicts the transfer function in Moriches and Shinnecock bays where long-term observations were not available. The model is a simplified tool to investigate changes in bay water level and enables the evaluation of future conditions and alternative geomorphological settings.

  3. Levels of trace metals in water and sediment from Tyume River and ...

    African Journals Online (AJOL)

    Higher levels of Cd (0.038 ± 0.004 to 0.044 ± 0.003 mg/l) and Pb (0.021 ± 0.004 to 0.035 ± 0.001 mg/l) were found in the river water, which may be detrimental to the “health” of the aquatic ecosystem and the rural communities that utilise the river water for ... Key words: trace metals, water, sediment, farmland, Tyume River

  4. Development and application of YSJ-1 type oil-water interface level gauge

    International Nuclear Information System (INIS)

    Sun Punan

    2003-01-01

    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

  5. 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.

  6. Effects of Barometric Fluctuations on Well Water-Level Measurements and Aquifer Test Data

    Energy Technology Data Exchange (ETDEWEB)

    FA Spane, Jr.

    1999-12-16

    The Pacific Northwest National Laboratory, as part of the Hanford Groundwater Monitoring Project, examines the potential for offsite migration of contamination within underlying aquifer systems. Well water-level elevation measurements from selected wells within these aquifer systems commonly form the basis for delineating groundwater-flow patterns (i.e., flow direction and hydraulic gradient). In addition, the analysis of water-level responses obtained in wells during hydrologic tests provides estimates of hydraulic properties that are important for evaluating groundwater-flow velocity and transport characteristics. Barometric pressure fluctuations, however, can have a discernible impact on well water-level measurements. These barometric effects may lead to erroneous indications of hydraulic head within the aquifer. Total hydraulic head (i.e., sum of the water-table elevation and the atmospheric pressure at the water-table surface) within the aquifer, not well water-level elevation, is the hydrologic parameter for determining groundwater-flow direction and hydraulic gradient conditions. Temporal variations in barometric pressure may also adversely affect well water-level responses obtained during hydrologic tests. If significant, adjustments or removal of these barometric effects from the test-response record may be required for quantitative hydraulic property determination. This report examines the effects of barometric fluctuations on well water-level measurements and evaluates adjustment and removal methods for determining areal aquifer head conditions and aquifer test analysis. Two examples of Hanford Site unconfined aquifer tests are examined that demonstrate barometric response analysis and illustrate the predictive/removal capabilities of various methods for well water-level and aquifer total head values. Good predictive/removal characteristics were demonstrated with best corrective results provided by multiple-regression deconvolution methods.

  7. A simple procedure to model water level fluctuations in partially inundated wetlands

    NARCIS (Netherlands)

    Spieksma, JFM; Schouwenaars, JM

    When modelling groundwater behaviour in wetlands, there are specific problems related to the presence of open water in small-sized mosaic patterns. A simple quasi two-dimensional model to predict water level fluctuations in partially inundated wetlands is presented. In this model, the ratio between

  8. Data quality assurance in pressure transducer-based automatic water level monitoring

    Science.gov (United States)

    Submersible pressure transducers integrated with data loggers have become relatively common water-level measuring devices used in flow or well water elevation measurements. However, drift, linearity, hysteresis and other problems can lead to erroneous data. Researchers at the USDA-ARS in Watkinsvill...

  9. 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 ...

  10. Accessibility levels to potable Water Supply in Rural Areas of Akwa ...

    African Journals Online (AJOL)

    `123456789jkl''''#

    1987-09-23

    Sep 23, 1987 ... number of water boreholes in the communities were collected and analyzed. The population of the communities provided a basis for evolving an index that measured the levels of access to potable water supply in the study area. The use of GIS was subsequently employed to map out the study area on the ...

  11. Development of a Regional Neural Network for Coastal Water Level Predictions

    National Research Council Canada - National Science Library

    Huang, Wenrui; Murray, Catherine; Kraus, Nicholas; Rosati, Julie

    2003-01-01

    .... Fortunately, the US National Oceanographic and Atmospheric Administration (NOAA) has a national network of water level monitoring stations distributed in regional scale that has been operating for several decades...

  12. Relationships among gender, cognitive style, academic major, and performance on the Piaget water-level task.

    Science.gov (United States)

    Hammer, R E; Hoffer, N; King, W L

    1995-06-01

    Many researchers have found that more college-age adults than would be expected fail Piaget's water-level task, with women failing more frequently than men. It has been hypothesized that differences in cognitive style may account for performance differences on the water-level task. In the present study, 27 male and 27 female architectural students and 27 male and 27 female liberal-arts students were assessed for their performance on both Piaget's Water-level Task and Witkin's Group Embedded Figures Test. No difference was found in performance of male and female architectural students on either task, but male liberal-arts students scored significantly higher than female liberal-arts students on both measures. A disembedding cognitive style predicted success on the water-level task for the architectural students but not for the liberal arts students.

  13. Great Lakes Daily Ice Observations at NOAA Water Level Gauge Sites, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — 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...

  14. SHORT-TERM AND LONG-TERM WATER LEVEL PREDICTION AT ONE RIVER MEASUREMENT LOCATION

    Directory of Open Access Journals (Sweden)

    Rudolf Scitovski

    2012-12-01

    Full Text Available Global hydrological cycles mainly depend on climate changes whose occurrence is predominantly triggered by solar and terrestrial influence, and the knowledge of the high water regime is widely applied in hydrology. Regular monitoring and studying of river water level behavior is important from several perspectives. On the basis of the given data, by using modifications of general approaches known from literature, especially from investigation in hydrology, the problem of long- and short-term water level forecast at one river measurement location is considered in the paper. Long-term forecasting is considered as the problem of investigating the periodicity of water level behavior by using linear-trigonometric regression and short-term forecasting is based on the modification of the nearest neighbor method. The proposed methods are tested on data referring to the Drava River level by Donji Miholjac, Croatia, in the period between the beginning of 1900 and the end of 2012.

  15. 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...

  16. Back-Analyses of Landfill Instability Induced by High Water Level: Case Study of Shenzhen Landfill

    Directory of Open Access Journals (Sweden)

    Ren Peng

    2016-01-01

    Full Text Available In June 2008, the Shenzhen landfill slope failed. This case is used as an example to study the deformation characteristics and failure mode of a slope induced by high water levels. An integrated monitoring system, including water level gauges, electronic total stations, and inclinometers, was used to monitor the slope failure process. The field measurements suggest that the landfill landslide was caused by a deep slip along the weak interface of the composite liner system at the base of the landfill. The high water level is considered to be the main factor that caused this failure. To calculate the relative interface shear displacements in the geosynthetic multilayer liner system, a series of numerical direct shear tests were carried out. Based on the numerical results, the composite lining system simplified and the centrifuge modeling technique was used to quantitatively evaluate the effect of water levels on landfill instability.

  17. Back-Analyses of Landfill Instability Induced by High Water Level: Case Study of Shenzhen Landfill

    Science.gov (United States)

    Peng, Ren; Hou, Yujing; Zhan, Liangtong; Yao, Yangping

    2016-01-01

    In June 2008, the Shenzhen landfill slope failed. This case is used as an example to study the deformation characteristics and failure mode of a slope induced by high water levels. An integrated monitoring system, including water level gauges, electronic total stations, and inclinometers, was used to monitor the slope failure process. The field measurements suggest that the landfill landslide was caused by a deep slip along the weak interface of the composite liner system at the base of the landfill. The high water level is considered to be the main factor that caused this failure. To calculate the relative interface shear displacements in the geosynthetic multilayer liner system, a series of numerical direct shear tests were carried out. Based on the numerical results, the composite lining system simplified and the centrifuge modeling technique was used to quantitatively evaluate the effect of water levels on landfill instability. PMID:26771627

  18. Changes in blood lead levels associated with use of chloramines in water treatment systems.

    Science.gov (United States)

    Miranda, Marie Lynn; Kim, Dohyeong; Hull, Andrew P; Paul, Christopher J; Galeano, M Alicia Overstreet

    2007-02-01

    More municipal water treatment plants are using chloramines as a disinfectant in order to reduce carcinogenic by-products. In some instances, this has coincided with an increase in lead levels in drinking water in those systems. Lead in drinking water can be a significant health risk. We sought to test the potential effect of switching to chloramines for disinfection in water treatment systems on childhood blood lead levels using data from Wayne County, located in the central Coastal Plain of North Carolina. We constructed a unified geographic information system (GIS) that links blood lead screening data with age of housing, drinking water source, and census data for 7,270 records. The data were analyzed using both exploratory methods and more formal multivariate techniques. The analysis indicates that the change to chloramine disinfection may lead to an increase in blood lead levels, the impact of which is progressively mitigated in newer housing. Introducing chloramines to reduce carcinogenic by-products may increase exposure to lead in drinking water. Our research provides guidance on adjustments in the local childhood lead poisoning prevention program that should accompany changes in water treatment. As similar research is conducted in other areas, and the underlying environmental chemistry is clarified, water treatment strategies can be optimized across the multiple objectives that municipalities face in providing high quality drinking water to local residents.

  19. 46 CFR 52.01-110 - Water-level indicators, water columns, gauge-glass connections, gauge cocks, and pressure gauges...

    Science.gov (United States)

    2010-10-01

    ... § 52.01-110 Water-level indicators, water columns, gauge-glass connections, gauge cocks, and pressure... 46 Shipping 2 2010-10-01 2010-10-01 false Water-level indicators, water columns, gauge-glass connections, gauge cocks, and pressure gauges (modifies PG-60). 52.01-110 Section 52.01-110 Shipping COAST...

  20. Maximum power point tracking

    International Nuclear Information System (INIS)

    Enslin, J.H.R.

    1990-01-01

    A well engineered renewable remote energy system, utilizing the principal of Maximum Power Point Tracking can be m ore cost effective, has a higher reliability and can improve the quality of life in remote areas. This paper reports that a high-efficient power electronic converter, for converting the output voltage of a solar panel, or wind generator, to the required DC battery bus voltage has been realized. The converter is controlled to track the maximum power point of the input source under varying input and output parameters. Maximum power point tracking for relative small systems is achieved by maximization of the output current in a battery charging regulator, using an optimized hill-climbing, inexpensive microprocessor based algorithm. Through practical field measurements it is shown that a minimum input source saving of 15% on 3-5 kWh/day systems can easily be achieved. A total cost saving of at least 10-15% on the capital cost of these systems are achievable for relative small rating Remote Area Power Supply systems. The advantages at larger temperature variations and larger power rated systems are much higher. Other advantages include optimal sizing and system monitor and control

  1. Cadmium accumulation in soils caused by contaminated irrigation water in relation to safety level of enviromental water

    Energy Technology Data Exchange (ETDEWEB)

    Ito, H; Iimura, K

    1974-01-01

    Adsorption of cadmium on the soil from irrigation water contaminated by human production activites were investigated. Both in the equilibrium and column experiments, the soils adsorbed more than 90 per cent of cadmium from the water containing 0.01 ppm cadmium and 18 or 300 ppm calcium. The amounts of cadmium adsorbed by the soils in the equilibrium experiments increased with the increasing concentrations (0.001-10 ppm) in accordance with the Freundlich's adsorption formula, the indices of which were near unity. In column experiments, the proportions of cadmium adsorbed by the soils from the water containing 0.01 ppm cadmium and 18 ppm calcium were equal to or more than those of calcium. It was estimated that if the water containing 0.01 ppm cadmium, that is the safety level of environmental water for human health by WHO and adopted as the permissible concentration by the Japanese Government, were irrigated in paddy fields, cadmium contents of the soils would exceed 1 ppm within a few years. Furthermore, on some of those contaminated soils, brown rice containing more than 1 ppm cadmium, that is the permissible concentration in brown rice authorised by the Japanese Government, will be produced. From the viewpoint of soil conservation from contamination, it is suggested that the permissible concentration of cadmium in the environment water should be lowered to at least one tenth of the present level. The exchange equilibriums in the soils between Cd and Ca and Cd and Na were discussed.

  2. 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.

  3. Regional Sea Level Scenarios for Coastal Risk Management: Managing the Uncertainty of Future Sea Level Change and Extreme Water Levels for Department of Defense Coastal Sites Worldwide

    Science.gov (United States)

    2016-04-01

    authors and do not necessarily reflect the view of the authors’ Agencies. MANAGING THE UNCERTAINTY OF FUTURE SEA LEVEL CHANGE AND EXTREME WATER LEVELS FOR...COASTAL RISK MANAGEMENT 2-20 contingent probabilities given their dependence on non-probabilistic emissions futures, have extended the ranges of...flood risk provides confidence in the associated projection as a true minimum value for risk management purposes. The contemporary rate observed by

  4. Water Level Fluctuations in the Congo Basin Derived from ENVISAT Satellite Altimetry

    Directory of Open Access Journals (Sweden)

    Mélanie Becker

    2014-09-01

    Full Text Available In the Congo Basin, the elevated vulnerability of food security and the water supply implies that sustainable development strategies must incorporate the effects of climate change on hydrological regimes. However, the lack of observational hydro-climatic data over the past decades strongly limits the number of studies investigating the effects of climate change in the Congo Basin. We present the largest altimetry-based dataset of water levels ever constituted over the entire Congo Basin. This dataset of water levels illuminates the hydrological regimes of various tributaries of the Congo River. A total of 140 water level time series are extracted using ENVISAT altimetry over the period of 2003 to 2009. To improve the understanding of the physical phenomena dominating the region, we perform a K-means cluster analysis of the altimeter-derived river level height variations to identify groups of hydrologically similar catchments. This analysis reveals nine distinct hydrological regions. The proposed regionalization scheme is validated and therefore considered reliable for estimating monthly water level variations in the Congo Basin. This result confirms the potential of satellite altimetry in monitoring spatio-temporal water level variations as a promising and unprecedented means for improved representation of the hydrologic characteristics in large ungauged river basins.

  5. Analysis of the relationship between water level fluctuation and seismicity in the Three Gorges Reservoir (China

    Directory of Open Access Journals (Sweden)

    Lifen Zhang

    2017-03-01

    Full Text Available The Three Gorges Reservoir is a good site for the further researches on reservoir induced seismicity due to decades' seismic monitoring. After the first water impounding in 2003, seismic activity becomes more frequent than that before water impoundment. In order to quantitatively study, the relationship between the water level fluctuation and earthquakes in TGR, we introduced statistical methods to attain the goal. First of all, we relocated the earthquakes in TGR region with double difference method and divided the earthquakes into 5 clusters with clustering analysis method. Secondly, to examine the impacts of water level fluctuation in different water filling stages on the seismic activity in the 5 clusters, a series of statistical analyses are applied. Pearson correlation results show that only the 175 m water level fluctuation has significantly positive impacts on the seismic activity in clusters Ⅰ, Ⅱ, Ⅲ and Ⅴ with correlation coefficients of 0.44, 0.38, 0.66 and 0.63. Cross-correlation analysis demonstrates that 0, 1, 0 and 0 month time delay separately for the clusters Ⅰ, Ⅱ, Ⅲ and Ⅴ exists. It illustrated the influences of the water loading and pore pressure diffusion on induced earthquakes. Cointegration tests and impulse response analysis denoted that the 175 m water level only had long term and significant effects just on the seismic events in the intersection region of the Fairy Mount Fault and Nine-brook Fault. One standard deviation shock to 175 m water level increased the seismic activity in cluster Ⅴ for the first 3 months, and then the negative influence was shown. After 7 months, the negative impulse response becomes stable. The long-term effect of the 175 m water impoundment also proved the important role of pore pressure diffusion in RIS with time.

  6. Assessment and the levels of radioactivity of natural radionuclides in drinking waters in China

    International Nuclear Information System (INIS)

    Liu Yulan

    1989-03-01

    In order to assess the levels of radioactivity of natural radionuclides in drinking waters and to estimate the internal doses of the population of China from ingestion, 1650 samples of waters were collected from normal radiation background areas of 28 provinces or autonomous regions of China. Radioactivity levels of U, Th, 226 Ra and 40 K in drinking waters were determined. The levels and the characteristics of distribution of 4 radionuclides are given. The results show that radioactivity levels in the southeast China are lower than in the north and northwest China. The average radioactivity levles of the 4 radionuclides in China close to the average levels given in UNSCEAR 1986 report. The result of estimation of internal doses from ingestion in the population of China is below the corresponding results given in UNSCEAR 1986 report, but near the result given by ICRP

  7. Trench water chemistry at commercially operated low-level radioactive waste disposal sites

    International Nuclear Information System (INIS)

    Pietrzak, R.F.; Dayal, R.; Kinsley, M.T.; Clinton, J.; Czyscinski, K.S.; Weiss, A.J.

    1982-01-01

    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 60 Co, in solution. 4 figures, 5 tables

  8. Monitoring of Water-Level Fluctuation of Lake Nasser Using Altimetry Satellite Data

    Science.gov (United States)

    El-Shirbeny, Mohammed A.; Abutaleb, Khaled A.

    2018-05-01

    Apart from the Renaissance Dam and other constructed dams on the River Nile tributaries, Egypt is classified globally as a state of scarce water. Egypt's water resources are very limited and do not contribute a significant amount to its water share except the River Nile (55.5 billion m3/year). While the number of population increases every year, putting more stress on these limited resources. This study aims to use remote-sensing data to assess the change in surface area and water-level variation in Lake Nasser using remote-sensing data from Landsat-8 and altimetry data. In addition, it investigates the use of thermal data from Landsat-8 to calculate water loss based on evaporation from Lake Nasser. The eight Landsat-8 satellite images were used to study the change in surface area of Lake Nasser representing winter (January) and summer (June/July) seasons in two consecutive years (2015 and 2016). Time series analyses for 10-day temporal resolution water-level data from Jason-2/OSTM and Jason-3 altimetry was carried out to investigate water-level trends over the long term (1993 and 2016) and short term (2015-2016) in correspondence with the change of the surface area. Results indicated a shrink in the lake surface area in 2016 of approximately 14% compared to the 2015 area. In addition, the evaporation rate in the lake is very high causing a loss of approximately 20% of the total water share from the river Nile.

  9. 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.

  10. The effect of applying different water levels and irrigation frequencies in propagating rosemary (Rosmarinus officinalis L.

    Directory of Open Access Journals (Sweden)

    Javier Giovanni Álvarez Herrera

    2010-01-01

    Full Text Available Rosemary seedlings are obtained by vegetative propagation because the seeds present low viability. Despite being an expanding crop, there is little information on water consumption during the propagation stage. Water levels and irrigation frequencies were therefore applied using a completely randomised design having a 4 x 2 factorial arrangement. The first factor concerned irrigation frequency (4 and 8 days and the second concerned water level (0.6, 0.8, 1.0 and 1.2 evaporation inside the greenhouse. A 1.0 coefficient combined with 4-day irrigation frequency presented the best results regarding height (39.3 cm, fresh weight, dry weight and branch length (146 cm. Water level affected the fresh and dry weight of leaves regardless of frequency. Relative water content in leaves did not present differences due to environmental conditions minimising treatment effect. Rooting percent- tage showed no significant differences regarding irrigation frequency or water level. Irrigation frequency did not affect rosemary growing pattern because sphagnum retains high moisture content. The best branch number (34 was obtained with 1.0 coefficient and 4-day frequency, this being important from the production point of view because this is the material which is sold. Water management changes photoassimilate distribution in rosemary plants.

  11. 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.

  12. Measuring water level in rivers and lakes from lightweight Unmanned Aerial Vehicles

    DEFF Research Database (Denmark)

    Bandini, Filippo; Jakobsen, Jakob; Olesen, Daniel Haugård

    2017-01-01

    The assessment of hydrologic dynamics in rivers, lakes, reservoirs and wetlands requires measurements of water level, its temporal and spatial derivatives, and the extent and dynamics of open water surfaces. Motivated by the declining number of ground-based measurement stations, research efforts...... complex water dynamics. Unmanned Aerial Vehicles (UAVs) can fill the gap between spaceborne and ground-based observations, and provide high spatial resolution and dense temporal coverage data, in quick turn-around time, using flexible payload design. This study focused on categorizing and testing sensors......, which comply with the weight constraint of small UAVs (around 1.5 kg), capable of measuring the range to water surface. Subtracting the measured range from the vertical position retrieved by the onboard Global Navigation Satellite System (GNSS) receiver, we can determine the water level (orthometric...

  13. Background level of natural radioactivities in a giant water Cherenkov detector and its surrounding environment

    International Nuclear Information System (INIS)

    Yamamoto, Masayoshi; Sakanoue, Masanobu; Komura, Kazuhisa; Ueno, Kaoru

    1989-01-01

    The KAMIOKANDE-II water Cherenkov detector for the measurement of nucleon decay and/or solar neutrino has been operating in the underground laboratory at a depth of 2,700 m.w.e. (meter water equivalent) in Kamioka mine of Gifu Prefecture. Concentrations of 238 U, 232 Th, 226 Ra and 222 Rn as the major background sources have been measured for various kinds of rocks, mine water, mine air and high purity water used as a detector during the period from August 1986 to December 1987. The concentration levels of these radionuclides and their seasonal variation have become clear. Some of these results have provided useful informations for decreasing the background level of water Cherenkov detector. (author)

  14. Maximum entropy methods

    International Nuclear Information System (INIS)

    Ponman, T.J.

    1984-01-01

    For some years now two different expressions have been in use for maximum entropy image restoration and there has been some controversy over which one is appropriate for a given problem. Here two further entropies are presented and it is argued that there is no single correct algorithm. The properties of the four different methods are compared using simple 1D simulations with a view to showing how they can be used together to gain as much information as possible about the original object. (orig.)

  15. Human impacts on tides overwhelm the effect of sea level rise on extreme water levels in the Rhine-Meuse delta

    NARCIS (Netherlands)

    Vellinga, N. E.; Hoitink, A. J F; van der Vegt, M.; Zhang, W.; Hoekstra, P.

    2014-01-01

    With the aim to link tidal and subtidal water level changes to human interventions, 70. years of water level data for the Rhine-Meuse tidal river network is analysed using a variety of statistical methods. Using a novel parameterization of probability density functions, mean high and low water

  16. Identification of Trihalomethanes (THMs Levels in Water Supply: A Case Study in Perlis, Malaysia

    Directory of Open Access Journals (Sweden)

    Ab Jalil Mohd Faizal

    2018-01-01

    Full Text Available In Malaysia, chlorination is used for drinking water disinfection at water treatment plants due to its cost-effectiveness and efficiency. However, the use of chlorine poses potential health risks due to the formation of disinfection by-products such as trihalomethanes (THMs. THMs are formed due to the reaction between chlorine and some natural organic matter. The objective of the study is to analyze the level of THMs in the water supply in Perlis, Malaysia. The water samples were collected from end-user tap water near the water treatment plant (WTP located in Perlis, including Timah Tasoh WTP, Kampung Sungai Baru WTP, Arau Phase I, II, III, and IV WTPs. The THMs were analyzed using a Gas Chromatography-Mass Spectrometry (GC/MS. The results showed that the water supply from Timah Tasoh WTP generates the most THMs, whereas Kuala Sungai Baru shows the fewest amounts of total THMs. In conclusion, the presence of THMs in tap water has caused great concern since these components can cause cancer in humans. Therefore, the identification of THM formation is crucial in order to make sure that the tap water quality remains at acceptable safety levels.

  17. Identification of Trihalomethanes (THMs) Levels in Water Supply: A Case Study in Perlis, Malaysia

    Science.gov (United States)

    Jalil, Mohd Faizal Ab; Hamidin, Nasrul; Anas Nagoor Gunny, Ahmad; Nihla Kamarudzaman, Ain

    2018-03-01

    In Malaysia, chlorination is used for drinking water disinfection at water treatment plants due to its cost-effectiveness and efficiency. However, the use of chlorine poses potential health risks due to the formation of disinfection by-products such as trihalomethanes (THMs). THMs are formed due to the reaction between chlorine and some natural organic matter. The objective of the study is to analyze the level of THMs in the water supply in Perlis, Malaysia. The water samples were collected from end-user tap water near the water treatment plant (WTP) located in Perlis, including Timah Tasoh WTP, Kampung Sungai Baru WTP, Arau Phase I, II, III, and IV WTPs. The THMs were analyzed using a Gas Chromatography-Mass Spectrometry (GC/MS). The results showed that the water supply from Timah Tasoh WTP generates the most THMs, whereas Kuala Sungai Baru shows the fewest amounts of total THMs. In conclusion, the presence of THMs in tap water has caused great concern since these components can cause cancer in humans. Therefore, the identification of THM formation is crucial in order to make sure that the tap water quality remains at acceptable safety levels.

  18. Theory of energy level and its application in water-loop heat pump system

    International Nuclear Information System (INIS)

    Yu, Qi Dong

    2017-01-01

    Highlights: • Novel theory of saving energy and its application in water loop heat pump. • Reverse energy caused by units to water loop and its solution. • New method for determining the energy-saving range of water loop heat pump. • Capacity model of auxiliary heat source and its size for all building types. • Advice for reducing total energy consumption of water loop heat pump. - Abstract: It is a difficult problem to how to determine the reverse energy caused by units to water loop when a water-loop heat pump (WLHP) is in cooling and heating simultaneous mode, which not only has a great impact on energy-saving rate but also decides the use of auxiliary heat source in winter. This paper presents a theory of energy level to improve the research on WLHP system by using the relationship among building, circulating water and units. In this theory, the circulating water replaces building load as a new method to convert the reverse energy into energy change of circulating water and the equation of energy level also is built to determine the energy-saving range of WLHP system and report the capacity model of auxiliary heat source for all building types. An office building with different auxiliary powers is tested to analyze system operation characteristic and the effect of auxiliary heat source on unit and system and the results validate previous conclusions and suggest that an energy balance should be considered between units and auxiliary power to improve overall operation.

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

    International Nuclear Information System (INIS)

    Marine, I.W.

    1975-01-01

    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.)

  20. Gestational exposure to high perchlorate concentrations in drinking water and neonatal thyroxine levels.

    Science.gov (United States)

    Amitai, Yona; Winston, Gary; Sack, Joseph; Wasser, Janice; Lewis, Matthew; Blount, Benjamin C; Valentin-Blasini, Liza; Fisher, Nirah; Israeli, Avi; Leventhal, Alex

    2007-09-01

    To assess the effect of gestational perchlorate exposure through drinking water on neonatal thyroxine (T(4)). T(4) values were compared among newborns in Ramat Hasharon, Israel, whose mothers resided in suburbs where drinking water contained perchlorate water exclusively (as determined by a telephone interview) were analyzed as a subset. Serum perchlorate levels in blood from donors residing in the area were used as proxy indicators of exposure. Neonatal T(4) values (mean +/- SD) in the very high, high, and low exposure groups were 13.9 +/- 3.8, 13.9 +/- 3.4, and 14.0 +/- 3.5 microg/dL, respectively (p = NS). Serum perchlorate concentrations in blood from donors residing in areas corresponding to these groups were 5.99 +/- 3.89, 1.19 +/- 1.37, and 0.44 +/- 0.55 microg/L, respectively. T(4) levels of neonates with putative gestational exposure to perchlorate in drinking water were not statistically different from controls. This study finds no change in neonatal T(4) levels despite maternal consumption of drinking water that contains perchlorate at levels in excess of the Environmental Protection Agency (EPA) drinking water equivalent level (24.5 microg/L) based on the National Research Council reference dose (RfD) [0.7 microg/(kg.day)]. Therefore the perchlorate RfD is likely to be protective of thyroid function in neonates of mothers with adequate iodide intake.

  1. 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.

  2. Assessment of impacts from water level fluctuations on fish in the Hanford Reach, Columbia River

    Energy Technology Data Exchange (ETDEWEB)

    Becker, C.D.; Fickeisen, D.H.; Montgomery, J.C.

    1981-05-01

    Observations on the effects of water level fluctuations in the Hanford Reach of the Columbia River, Washington, were made in 1976 and 1977. The two years provided contrasting flow regimes: high water and fluctuations of greater magnitude prevailed in 1976; low water and higher temperatures prevailed in 1977. Situations where fish and other aquatic organisms were destroyed by changing water levels were observed and evaluated each year in three study areas: Hanford, F-Area, and White Bluffs sloughs. Losses primarily were due to stranding, entrapment (with or without complete dewatering), and predation. Juvenile fish were more susceptible to entrapment and stranding than were adult fish. Estimates of actual losses were biased and conservative because relatively few fish could be found after each decline of water level and dewatering. The most valued species of fish affected by water level fluctuations at Hanford were the anadromus fall chinook salmon (Oncorhynchus tshawytscha) and the resident smallmouth bass (Micropterus dolomieui). Crucial periods for chinook salmon occurred during winter when incubating eggs were in the gravel of the main channel, and before and during seaward migration in the spring when fry were abundant in shoreline zones. The crucial period for smallmouth bass was during spring and early summer when adults were spawning in warmed sloughs and shoreline zones. Chinook salmon and smallmouth bass fry were vulnerable to stranding and entrapment, and smallmouth bass nests were susceptible to exposure and temperature changes resulting from repeated water level fluctuations. Thus, flow manipulation may be crucial to their survival. The extent to which other species of riverine fish were affected by water level fluctuations depended upon their use of shoreline zones for spawning and rearing young.

  3. Combining urbanization and hydrodynamics data to evaluate sea level rise impacts on coastal water resources

    Science.gov (United States)

    Young, C. R.; Martin, J. B.

    2016-02-01

    Assessments of the potential for salt water intrusion due to sea level rise require consideration of both coastal hydrodynamic and human activity thresholds. In siliciclastic systems, sea level rise may cause salt intrusion to coastal aquifers at annual or decadal scales, whereas in karst systems salt intrudes at the tidal scalse. In both cases, human activity impacts the freshwater portion of the system by altering the water demand on the aquifer. We combine physicochemical and human activity data to evaluate impact of sea level rise on salt intrusion to siliclastic (Indian River Lagoon, Fl, USA) and karst (Puerto Morelos, Yucatan, Mexico) systems under different sea level rise rate scenarios. Two hydrodynamic modeling scenarios are considered; flux controlled and head controlled. Under a flux controlled system hydraulic head gradients remain constant during sea level rise while under a head controlled system hydraulic graidents diminish, allowing saltwater intrusion. Our model contains three key terms; aquifer recharge, groundwater discharge and hydraulic conductivity. Groundwater discharge and hydraulic conductivity were calculated based on high frequency (karst system) and decadal (siliciclastic system) field measurements. Aquifer recharge is defined as precipitation less evapotranspiration and water demand was evaluated based on urban planning data that provided the regional water demand. Water demand includes agricultural area, toursim, traffic patterns, garbage collection and total population. Water demand was initially estimated using a partial leaset squares regression based on these variables. Our model indicates that water demand depends most on agricultural area, which has changed significantly over the last 30 years. In both systems, additional water demand creates a head controlled scenario, thus increaseing the protential fo salt intrusion with projected sea level rise.

  4. The need for the use of high-level radiation in water treatment and in waste-water (sewage) treatment

    International Nuclear Information System (INIS)

    Nielson, N.E.

    1975-01-01

    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)

  5. Characterising Bedrock Aquifer Systems in Korea Using Paired Water-Level Monitoring Data

    Directory of Open Access Journals (Sweden)

    Jae Min Lee

    2017-06-01

    Full Text Available This study focused on characterising aquifer systems based on water-level changes observed systematically at 159 paired groundwater monitoring wells throughout Korea. Using spectral analysis, principal component analysis (PCA, and cross-correlation analysis with linear regression, aquifer conditions were identified from the comparison of water-level changes in shallow alluvial and deep bedrock monitoring wells. The spectral analysis could identify the aquifer conditions (i.e., unconfined, semi-confined and confined of 58.5% of bedrock wells and 42.8% of alluvial wells: 93 and 68 wells out of 159 wells, respectively. Even among the bedrock wells, 50 wells (53.7% exhibited characteristics of the unconfined condition, implying significant vulnerability of the aquifer to contaminants from the land surface and shallow depths. It appears to be better approach for deep bedrock aquifers than shallow alluvial aquifers. However, significant portions of the water-level changes remained unclear for categorising aquifer conditions due to disturbances in data continuity. For different aquifer conditions, PCA could show typical pattern and factor scores of principal components. Principal component 1 due to wet-and-dry seasonal changes and water-level response time was dominant covering about 55% of total variances of each aquifer conditions, implying the usefulness of supplementary method of aquifer characterisation. Cross-correlation and time-lag analysis in the water-level responses to precipitations clearly show how the water levels in shallow and deep wells correspond in time scale. No significant differences in time-lags was found between shallow and deep wells. However, clear time-lags were found to be increasing from unconfined to confined conditions: from 1.47 to 2.75 days and from 1.78 to 2.75 days for both shallow alluvial and deep bedrock wells, respectively. In combination of various statistical methods, three types of water-level fluctuation

  6. Design of the Demineralized Water Make-up Line to Maintain the Normal Pool Water Level of the Reactor Pool in the Research Reactor

    International Nuclear Information System (INIS)

    Yoon, Hyun Gi; Choi, Jung Woon; Yoon, Ju Hyeon; Chi, Dae Young

    2012-01-01

    In many research reactors, hot water layer system (HWLS) is used to minimize the pool top radiation level. Reactor pool divided into the hot water layer at the upper part of pool and the cold part below the hot water layer with lower temperature during normal operation. Water mixing between these layers is minimized because the hot water layer is formed above cold water. Therefore the hot water layer suppresses floatation of cold water and reduces the pool top radiation level. Pool water is evaporated form the surface to the building hall because of high temperature of the hot water layer; consequently the pool level is continuously fallen. Therefore, make-up water is necessary to maintain the normal pool level. There are two way to supply demineralized water to the pool, continuous and intermittent methods. In this system design, the continuous water make-up method is adopted to minimize the disturbance of the reactor pool flow. Also, demineralized water make-up is connected to the suction line of the hot water layer system to raise the temperature of make-up water. In conclusion, make-up demineralized water with high temperature is continuously supplied to the hot water layer in the pool

  7. Radar Based Flow and Water Level Forecasting in Sewer Systems:a danisk case study

    OpenAIRE

    Thorndahl, Søren; Rasmussen, Michael R.; Grum, M.; Neve, S. L.

    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 promis...

  8. Variation of radon levels in spring water with meteorological parameters and seismic events in Garhwal Himalayas

    International Nuclear Information System (INIS)

    Prasad, Yogesh; Prasad, Ganesh; Negi, M.S.; Ramola, R.C.; Choubey, V.M.

    2006-01-01

    Radon is being measured continuously in spring water at Badshahi Thaul Campus, Tehri Garhwal in Himalayan region by using radon emanometer since December 2002. An effort was made to correlate the variance of radon concentration in spring water with meteorological parameters and seismic events in study area. The positive correlation (coefficient = 0.79, 0.53, 0.60 and 0.70) was observed between measured radon concentration and minimum and maximum temperature, relative humidity and water discharge rate from the spring, respectively. However, no correlation was recorded between radon concentration and rain fall in the study area. Sudden increase in radon concentration in spring water were observed before the earthquakes occurred on 24 January 2003 of magnitude 3.4 on Richter scale having epicenter near Uttarkashi in Garhwal Himalaya and on 31 January 2003 of magnitude 3.1 on Richter scale having epicenter almost in same area. Similar changes in radon concentration were recorded before the earthquakes occurred on 4 April 2003 with magnitude 4.0 having epicenter near Almora in Kumaon Himalaya and on 26 May 2003 having magnitude 3.5 in Chamoli region of Garhwal Himalaya. Regular radon anomaly was recorded with micro seismic events from 5th August to 4th September 2003, which is discussed in detail. The impact of non geophysical and geophysical events on radon concentration in spring water is discussed in details. This type of study will help us to develop earthquake alarm model from radon in near future. (author)

  9. Transpiration response of upland rice to water deficit changed by different levels of eucalyptus biochar

    Directory of Open Access Journals (Sweden)

    Rogério Gomes Pereira

    2012-05-01

    Full Text Available The objective of this work was to evaluate the effect of eucalyptus biochar on the transpiration rate of upland rice 'BRSMG Curinga' as an alternative means to decrease the effect of water stress on plant growth and development. Two-pot experiments were carried out using a completely randomized block design, in a split-plot arrangement, with six replicates. Main plots were water stress (WS and no-water stress (NWS, and the subplots were biochar doses at 0, 6, 12 and 24% in growing medium (sand. Total transpirable soil water (TTSW, the p factor - defined as the average fraction of TTSW which can be depleted from the root zone before water stress limits growth -, and the normalized transpiration rate (NTR were determined. Biochar addition increased TTSW and the p factor, and reduced NTR. Consequently, biochar addition was able to change the moisture threshold (p factor of the growing medium, up to 12% maximum concentration, delaying the point where transpiration declines and affects yield.

  10. The ecological effects of water level fluctuation and phosphate enrichment in mesotrophic peatlands are strongly mediated by soil chemistry

    NARCIS (Netherlands)

    Mettrop, I.S.; Rutte, M.D.; Kooijman, A.M.; Lamers, L.P.M.

    2015-01-01

    Since the re-establishment of a more natural water regime is considered by water management in wetlands with artificially stable water levels, the biogeochemical and ecological effects of water level fluctuation with different nutrient loads should be investigated. This is particularly important for

  11. Analysis of changes in water-level dynamics at selected sites in the Florida Everglades

    Science.gov (United States)

    Conrads, Paul; Benedict, Stephen T.

    2013-01-01

    The historical modification and regulation of the hydrologic patterns in the Florida Everglades have resulted in changes in the ecosystem of South Florida and the Florida Everglades. Since the 1970s, substantial focus has been given to the restoration of the Everglades ecosystem. The U.S. Geological Survey through its Greater Everglades Priority Ecosystem Science and National Water-Quality Assessment Programs has been providing scientific information to resource managers to assist in the Everglades restoration efforts. The current investigation included development of a simple method to identify and quantify changes in historical hydrologic behavior within the Everglades that could be used by researchers to identify responses of ecological communities to those changes. Such information then could be used by resource managers to develop appropriate water-management practices within the Everglades to promote restoration. The identification of changes in historical hydrologic behavior within the Everglades was accomplished by analyzing historical time-series water-level data from selected gages in the Everglades using (1) break-point analysis of cumulative Z-scores to identify hydrologic changes and (2) cumulative water-level frequency distribution curves to evaluate the magnitude of those changes. This analytical technique was applied to six long-term water-level gages in the Florida Everglades. The break-point analysis for the concurrent period of record (1978–2011) identified 10 common periods of changes in hydrologic behavior at the selected gages. The water-level responses at each gage for the 10 periods displayed similarity in fluctuation patterns, highlighting the interconnectedness of the Florida Everglades hydrologic system. While the patterns were similar, the analysis also showed that larger fluctuations in water levels between periods occurred in Water Conservation Areas 2 and 3 in contrast to those in Water Conservation Area 1 and the Everglades

  12. Maximum Entropy Fundamentals

    Directory of Open Access Journals (Sweden)

    F. Topsøe

    2001-09-01

    Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over

  13. Sedimentary noise and sea levels linked to land-ocean water exchange and obliquity forcing.

    Science.gov (United States)

    Li, Mingsong; Hinnov, Linda A; Huang, Chunju; Ogg, James G

    2018-03-08

    In ancient hothouses lacking ice sheets, the origins of large, million-year (myr)-scale sea-level oscillations remain a mystery, challenging current models of sea-level change. To address this mystery, we develop a sedimentary noise model for sea-level changes that simultaneously estimates geologic time and sea level from astronomically forced marginal marine stratigraphy. The noise model involves two complementary approaches: dynamic noise after orbital tuning (DYNOT) and lag-1 autocorrelation coefficient (ρ 1 ). Noise modeling of Lower Triassic marine slope stratigraphy in South China reveal evidence for global sea-level variations in the Early Triassic hothouse that are anti-phased with continental water storage variations in the Germanic Basin. This supports the hypothesis that long-period (1-2 myr) astronomically forced water mass exchange between land and ocean reservoirs is a missing link for reconciling geological records and models for sea-level change during non-glacial periods.

  14. Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model

    International Nuclear Information System (INIS)

    K. Rehfeldt

    2004-01-01

    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

  15. Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model

    Energy Technology Data Exchange (ETDEWEB)

    K. Rehfeldt

    2004-10-08

    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

  16. 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.

  17. 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

  18. Plasticity in leaf-level water relations of tropical rainforest trees in response to experimental drought.

    Science.gov (United States)

    Binks, Oliver; Meir, Patrick; Rowland, Lucy; da Costa, Antonio Carlos Lola; Vasconcelos, Steel Silva; de Oliveira, Alex Antonio Ribeiro; Ferreira, Leandro; Christoffersen, Bradley; Nardini, Andrea; Mencuccini, Maurizio

    2016-07-01

    The tropics are predicted to become warmer and drier, and understanding the sensitivity of tree species to drought is important for characterizing the risk to forests of climate change. This study makes use of a long-term drought experiment in the Amazon rainforest to evaluate the role of leaf-level water relations, leaf anatomy and their plasticity in response to drought in six tree genera. The variables (osmotic potential at full turgor, turgor loss point, capacitance, elastic modulus, relative water content and saturated water content) were compared between seasons and between plots (control and through-fall exclusion) enabling a comparison between short- and long-term plasticity in traits. Leaf anatomical traits were correlated with water relation parameters to determine whether water relations differed among tissues. The key findings were: osmotic adjustment occurred in response to the long-term drought treatment; species resistant to drought stress showed less osmotic adjustment than drought-sensitive species; and water relation traits were correlated with tissue properties, especially the thickness of the abaxial epidermis and the spongy mesophyll. These findings demonstrate that cell-level water relation traits can acclimate to long-term water stress, and highlight the limitations of extrapolating the results of short-term studies to temporal scales associated with climate change. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  19. Evolution of caesium 137 levels in coconut water and copra in french Polynesia, since 1967

    International Nuclear Information System (INIS)

    Kabis de Saint-Chamas, L.; Bablet, J.P.; Ducousso, R.; Arnould, C.

    1991-01-01

    Nuclear experiments have been carried out by France in french Polynesia since 1966. The tests were first atmospheric, they have been underground since 1975. The experiment monitoring programme includes monitoring of 137 Cs contents in coconuts from the whole french polynesian territory. The methodology is described and the results of the 2 589 samples collected for 1967 to 1988 are presented. The maximum content found since 1967 is 52 Bq.kg -1 for coconut water and 289 Bq.kg -1 for coconut copra. The decrease of 137 Cs content is constant without discontinuity, whatever the distance from the explosion sites. The committed dose equivalent from 137 Cs delivered by coconut water and copra consumption represents only a few microsieverts a year [fr

  20. Probable maximum flood control

    International Nuclear Information System (INIS)

    DeGabriele, C.E.; Wu, C.L.

    1991-11-01

    This study proposes preliminary design concepts to protect the waste-handling facilities and all shaft and ramp entries to the underground from the probable maximum flood (PMF) in the current design configuration for the proposed Nevada Nuclear Waste Storage Investigation (NNWSI) repository protection provisions were furnished by the United States Bureau of Reclamation (USSR) or developed from USSR data. Proposed flood protection provisions include site grading, drainage channels, and diversion dikes. Figures are provided to show these proposed flood protection provisions at each area investigated. These areas are the central surface facilities (including the waste-handling building and waste treatment building), tuff ramp portal, waste ramp portal, men-and-materials shaft, emplacement exhaust shaft, and exploratory shafts facility

  1. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1988-01-01

    The maximum entropy (MaxEnt) principle has been successfully used in image reconstruction in a wide variety of fields. We review the need for such methods in data analysis and show, by use of a very simple example, why MaxEnt is to be preferred over other regularizing functions. This leads to a more general interpretation of the MaxEnt method, and its use is illustrated with several different examples. Practical difficulties with non-linear problems still remain, this being highlighted by the notorious phase problem in crystallography. We conclude with an example from neutron scattering, using data from a filter difference spectrometer to contrast MaxEnt with a conventional deconvolution. 12 refs., 8 figs., 1 tab

  2. Solar maximum observatory

    International Nuclear Information System (INIS)

    Rust, D.M.

    1984-01-01

    The successful retrieval and repair of the Solar Maximum Mission (SMM) satellite by Shuttle astronauts in April 1984 permitted continuance of solar flare observations that began in 1980. The SMM carries a soft X ray polychromator, gamma ray, UV and hard X ray imaging spectrometers, a coronagraph/polarimeter and particle counters. The data gathered thus far indicated that electrical potentials of 25 MeV develop in flares within 2 sec of onset. X ray data show that flares are composed of compressed magnetic loops that have come too close together. Other data have been taken on mass ejection, impacts of electron beams and conduction fronts with the chromosphere and changes in the solar radiant flux due to sunspots. 13 references

  3. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1989-01-01

    The maximum entropy (MaxEnt) principle has been successfully used in image reconstruction in a wide variety of fields. The author reviews the need for such methods in data analysis and shows, by use of a very simple example, why MaxEnt is to be preferred over other regularizing functions. This leads to a more general interpretation of the MaxEnt method, and its use is illustrated with several different examples. Practical difficulties with non-linear problems still remain, this being highlighted by the notorious phase problem in crystallography. He concludes with an example from neutron scattering, using data from a filter difference spectrometer to contrast MaxEnt with a conventional deconvolution. 12 refs., 8 figs., 1 tab

  4. Functional Maximum Autocorrelation Factors

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Nielsen, Allan Aasbjerg

    2005-01-01

    MAF outperforms the functional PCA in concentrating the interesting' spectra/shape variation in one end of the eigenvalue spectrum and allows for easier interpretation of effects. Conclusions. Functional MAF analysis is a useful methods for extracting low dimensional models of temporally or spatially......Purpose. We aim at data where samples of an underlying function are observed in a spatial or temporal layout. Examples of underlying functions are reflectance spectra and biological shapes. We apply functional models based on smoothing splines and generalize the functional PCA in......\\verb+~+\\$\\backslash\\$cite{ramsay97} to functional maximum autocorrelation factors (MAF)\\verb+~+\\$\\backslash\\$cite{switzer85,larsen2001d}. We apply the method to biological shapes as well as reflectance spectra. {\\$\\backslash\\$bf Methods}. MAF seeks linear combination of the original variables that maximize autocorrelation between...

  5. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yunji; Jing, Bing-Yi; Gao, Xin

    2015-01-01

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  6. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan

    2015-02-12

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  7. Application of environmental isotopes to determine the cause of rising water levels in Lake Beseka, Ethiopia

    International Nuclear Information System (INIS)

    Zemedagegnehu, E.; Travi, Y.; Aggarwal, P.

    1999-01-01

    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 Km 2 to the present 40 Km 2 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

  8. Analysis of the impact of water level fluctuations on macrophytes in Miyun Reservoir after receiving water transferred by the South-to-North Water Diversion Project

    Science.gov (United States)

    Yu, L.; Gu, H.; Lou, C. H.; Zhang, L.; Meng, Q. Y.

    2016-08-01

    As the main primary producers in aquatic ecosystems, macrophytes affect the structure and function of aquatic ecosystems, and their distribution is controlled by water depth. Miyun Reservoir in Beijing will have to experience substantial changes in water level and surface area as it begins to receive water transferred by the South-to-North Water Diversion Project, which will have an adverse impact on the macrophytes growing there. In this study, a hydrodynamic model was constructed with MIKE21 and then used in a simulation in three scenarios: dry year, normal year and wet year. The results suggest that during water diversion, the annual and interannual water level fluctuations will be too significant for them to adapt and as a result, the original macrophytes in the reservoir tend to die and disappear completely. The area of the zone suitable for macrophyte growth, or suitable growth zone (SGZ), fluctuated. Restricted by the main dam and auxiliary dam to its south, the overall suitable growth zone moved toward the northeast and northwest of the reservoir, with a northeastward movement of its centroid. The distance and path of movement varied between scenarios. After the water diversion was completed, the suitable growth zone shrunk in the three scenarios. It is predicted that the macrophyte species diversity and richness of the reservoir can recover to the levels recorded before water diversion only in dry year. These results suggest that manual interventions should be implemented after water diversion to speed up the natural recovery of aquatic plant communities in Miyun Reservoir and thereby maintain the stability of the aquatic ecosystem.

  9. Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation.

    Science.gov (United States)

    Susko, Michele L; Bloom, Michael S; Neamtiu, Iulia A; Appleton, Allison A; Surdu, Simona; Pop, Cristian; Fitzgerald, Edward F; Anastasiu, Doru; Gurzau, Eugen S

    2017-04-01

    High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiṣ County, Romania. Women (n=94) with planned pregnancies of 5-20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Level of Fluoride in Soil, Grain and Water in Jalgaon District, Maharashtra, India.

    Science.gov (United States)

    Naik, Rahul Gaybarao; Dodamani, Arun Suresh; Vishwakarma, Prashanth; Jadhav, Harish Chaitram; Khairnar, Mahesh Ravindra; Deshmukh, Manjiri Abhay; Wadgave, Umesh

    2017-02-01

    Fluoride has an influence on both oral as well as systemic health. The major source of fluoride to body is through drinking water as well as through diet. Staple diet mainly depends on local environmental factors, food grains grown locally, its availability etc. Determination of fluoride level in these food grains is important. So, estimation of the amount of fluoride in grains and its relation to the sources of fluoride used for their cultivation viz., soil and water is important. To estimate the relation of fluoride concentration in grains (Jowar) with respect to that of soil and water used for their cultivation. Fifteen samples each of soil, water and grains were collected using standardized method from the same farm fields of randomly selected villages of Jalgaon district. Fluoride ion concentration was determined in laboratory using SPADNS technique. Mean difference in fluoride levels in between the groups were analyzed using ANOVA and Post-Hoc Tukey test. Linear regression method was applied to analyse the association of the fluoride content of grain with water and soil. There was a significant difference in between mean fluoride levels of soil and water (pwater and grain was found to be non significant (p=0.591). Also fluoride levels in all the three groups showed significant association with each other. Fluoride level of soil, grains and water should be adjusted to an optimum level. Soil has positive correlation with respect to uptake of fluoride by Jowar grains. So, Jowar grains with optimum fluoride content should be made available in the commercial markets so that oral and general health can be benefitted.

  11. Inferring time‐varying recharge from inverse analysis of long‐term water levels

    Science.gov (United States)

    Dickinson, Jesse; Hanson, R.T.; Ferré, T.P.A.; Leake, S.A.

    2004-01-01

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

  12. 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.

  13. Hydration level is an internal variable for computing motivation to obtain water rewards in monkeys.

    Science.gov (United States)

    Minamimoto, Takafumi; Yamada, Hiroshi; Hori, Yukiko; Suhara, Tetsuya

    2012-05-01

    In the process of motivation to engage in a behavior, valuation of the expected outcome is comprised of not only external variables (i.e., incentives) but also internal variables (i.e., drive). However, the exact neural mechanism that integrates these variables for the computation of motivational value remains unclear. Besides, the signal of physiological needs, which serves as the primary internal variable for this computation, remains to be identified. Concerning fluid rewards, the osmolality level, one of the physiological indices for the level of thirst, may be an internal variable for valuation, since an increase in the osmolality level induces drinking behavior. Here, to examine the relationship between osmolality and the motivational value of a water reward, we repeatedly measured the blood osmolality level, while 2 monkeys continuously performed an instrumental task until they spontaneously stopped. We found that, as the total amount of water earned increased, the osmolality level progressively decreased (i.e., the hydration level increased) in an individual-dependent manner. There was a significant negative correlation between the error rate of the task (the proportion of trials with low motivation) and the osmolality level. We also found that the increase in the error rate with reward accumulation can be well explained by a formula describing the changes in the osmolality level. These results provide a biologically supported computational formula for the motivational value of a water reward that depends on the hydration level, enabling us to identify the neural mechanism that integrates internal and external variables.

  14. 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

  15. A Hydro-Economic Model for Water Level Fluctuations: Combining Limnology with Economics for Sustainable Development of Hydropower

    Science.gov (United States)

    Hirsch, Philipp Emanuel; Schillinger, Sebastian; Weigt, Hannes; Burkhardt-Holm, Patricia

    2014-01-01

    Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reservoirs are influenced by the operator of a hydropower plant, who discharges water through the turbines or stores water in the reservoir, in a fashion that maximizes profit. This rationale governs the seasonal operation scheme and hence determines the water levels within the boundaries of the reservoir's water balance. For progress towards a sustainable development of hydropower, the benefits of this form of electricity generation have to be weighed against the possible detrimental effects of the anthropogenic water level fluctuations. We developed a hydro-economic model that combines an economic optimization function with hydrological estimators of the water balance of a reservoir. Applying this model allowed us to accurately predict water level fluctuations in a reservoir. The hydro-economic model also allowed for scenario calculation of how water levels change with climate change scenarios and with a change in operating scheme of the reservoir (increase in turbine capacity). Further model development will enable the consideration of a variety of additional parameters, such as water withdrawal for irrigation, drinking water supply, or altered energy policies. This advances our ability to sustainably manage water resources that must meet both economic and environmental demands. PMID:25526619

  16. A hydro-economic model for water level fluctuations: combining limnology with economics for sustainable development of hydropower.

    Directory of Open Access Journals (Sweden)

    Philipp Emanuel Hirsch

    Full Text Available Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reservoirs are influenced by the operator of a hydropower plant, who discharges water through the turbines or stores water in the reservoir, in a fashion that maximizes profit. This rationale governs the seasonal operation scheme and hence determines the water levels within the boundaries of the reservoir's water balance. For progress towards a sustainable development of hydropower, the benefits of this form of electricity generation have to be weighed against the possible detrimental effects of the anthropogenic water level fluctuations. We developed a hydro-economic model that combines an economic optimization function with hydrological estimators of the water balance of a reservoir. Applying this model allowed us to accurately predict water level fluctuations in a reservoir. The hydro-economic model also allowed for scenario calculation of how water levels change with climate change scenarios and with a change in operating scheme of the reservoir (increase in turbine capacity. Further model development will enable the consideration of a variety of additional parameters, such as water withdrawal for irrigation, drinking water supply, or altered energy policies. This advances our ability to sustainably manage water resources that must meet both economic and environmental demands.

  17. A hydro-economic model for water level fluctuations: combining limnology with economics for sustainable development of hydropower.

    Science.gov (United States)

    Hirsch, Philipp Emanuel; Schillinger, Sebastian; Weigt, Hannes; Burkhardt-Holm, Patricia

    2014-01-01

    Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reservoirs are influenced by the operator of a hydropower plant, who discharges water through the turbines or stores water in the reservoir, in a fashion that maximizes profit. This rationale governs the seasonal operation scheme and hence determines the water levels within the boundaries of the reservoir's water balance. For progress towards a sustainable development of hydropower, the benefits of this form of electricity generation have to be weighed against the possible detrimental effects of the anthropogenic water level fluctuations. We developed a hydro-economic model that combines an economic optimization function with hydrological estimators of the water balance of a reservoir. Applying this model allowed us to accurately predict water level fluctuations in a reservoir. The hydro-economic model also allowed for scenario calculation of how water levels change with climate change scenarios and with a change in operating scheme of the reservoir (increase in turbine capacity). Further model development will enable the consideration of a variety of additional parameters, such as water withdrawal for irrigation, drinking water supply, or altered energy policies. This advances our ability to sustainably manage water resources that must meet both economic and environmental demands.

  18. 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.

  19. Modeling Caspian Sea water level oscillations under different scenarios of increasing atmospheric carbon dioxide concentrations.

    Science.gov (United States)

    Roshan, Gholamreza; Moghbel, Masumeh; Grab, Stefan

    2012-12-12

    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.

  20. Non-renewable water use on the globe and its implication to sea level change

    Science.gov (United States)

    Oki, T.; Pokhrel, Y. N.; Hanasaki, N.; Koirala, S.; Kanae, S.

    2012-12-01

    The real hydrological cycles on the Earth are not natural anymore. Global hydrological model simulations of the water cycle and available water resources should have an ability to consider the effects of human interventions on hydrological cycles. Anthropogenic activity modules, such as reservoir operation, crop growth and water demand in croplands, and environmental flows, were incorporated into a land surface model to form a new model, MAT-HI. Total terrestrial water storages (TWS) in large river basins were estimated using the new model by off-line simulation, and compared with the TWS observed by GRACE for 2002-2007. MAT-HI was further coupled with a module representing the ground water level fluctuations, and consists a new land surface scheme HiGW-MAT (Human Intervention and Ground Water coupled MATSIRO). HiGW-MAT is also associated with a scheme tracing the origin and flow path with the consideration on the sources of water withdrawal from stream flow, medium-size reservoirs and nonrenewable groundwater in addition to precipitation to croplands which enabled the assessment of the origin of water producing major crops. Areas highly dependent on nonrenewable groundwater are detected in the Pakistan, Bangladesh, Western part of India, north and western parts of China, some regions in the Arabian Peninsula, and the western part of the United States through Mexico. Cumulative nonrenewable groundwater withdrawals estimated by the model are corresponding fairly well with the country statistics of total groundwater withdrawals. Ground water table depletions in large aquifers in US estimated by HiGW-MAT were compared with in-situ observational data, and the correspondences are very good. Mean global exploitation of ground water for 2000 estimated by HiGW-MAT is 360 km3/y as an excess of ground water withdrawal over natural recharge into aquifer. This unsustainable groundwater use, together with artificial reservoir water impoundment, climate-driven changes in

  1. Towards tributyltin quantification in natural water at the Environmental Quality Standard level required by the Water Framework Directive.

    Science.gov (United States)

    Alasonati, Enrica; Fettig, Ina; Richter, Janine; Philipp, Rosemarie; Milačič, Radmila; Sčančar, Janez; Zuliani, Tea; Tunç, Murat; Bilsel, Mine; Gören, Ahmet Ceyhan; Fisicaro, Paola

    2016-11-01

    The European Union (EU) has included tributyltin (TBT) and its compounds in the list of priority water pollutants. Quality standards demanded by the EU Water Framework Directive (WFD) require determination of TBT at so low concentration level that chemical analysis is still difficult and further research is needed to improve the sensitivity, the accuracy and the precision of existing methodologies. Within the frame of a joint research project "Traceable measurements for monitoring critical pollutants under the European Water Framework Directive" in the European Metrology Research Programme (EMRP), four metrological and designated institutes have developed a primary method to quantify TBT in natural water using liquid-liquid extraction (LLE) and species-specific isotope dilution mass spectrometry (SSIDMS). The procedure has been validated at the Environmental Quality Standard (EQS) level (0.2ngL(-1) as cation) and at the WFD-required limit of quantification (LOQ) (0.06ngL(-1) as cation). The LOQ of the methodology was 0.06ngL(-1) and the average measurement uncertainty at the LOQ was 36%, which agreed with WFD requirements. The analytical difficulties of the method, namely the presence of TBT in blanks and the sources of measurement uncertainties, as well as the interlaboratory comparison results are discussed in detail. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation

    International Nuclear Information System (INIS)

    Susko, Michele L.; Bloom, Michael S.; Neamtiu, Iulia A.; Appleton, Allison A.; Surdu, Simona; Pop, Cristian; Fitzgerald, Edward F.; Anastasiu, Doru

    2017-01-01

    High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiá¹£ County, Romania. Women (n=94) with planned pregnancies of 5–20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1 µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. - Highlights: • We assessed low level drinking water arsenic as a predictor of fecundability. • Arsenic did

  3. Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation

    Energy Technology Data Exchange (ETDEWEB)

    Susko, Michele L. [Department of Epidemiology and Biostatistics, University at Albany, State University of New York, Rensselaer, New York (United States); Bloom, Michael S., E-mail: mbloom@albany.edu [Department of Epidemiology and Biostatistics, University at Albany, State University of New York, Rensselaer, New York (United States); Department of Environmental Health Sciences, University at Albany, State University of New York, Rensselaer, New York (United States); Neamtiu, Iulia A. [Health Department, Environmental Health Center, Cluj-Napoca (Romania); IMOGEN Research Institute, Cluj-Napoca (Romania); Appleton, Allison A. [Department of Epidemiology and Biostatistics, University at Albany, State University of New York, Rensselaer, New York (United States); Surdu, Simona [Department of Environmental Health Sciences, University at Albany, State University of New York, Rensselaer, New York (United States); Pop, Cristian [Physico-chemical and Biotoxicological Analysis Laboratory, Environmental Health Center, Cluj-Napoca (Romania); Cluj School of Public Health - College of Political, Administrative and Communication Sciences, Babeș-Bolyai University, Cluj-Napoca (Romania); Faculty of Environmental Science and Engineering, Babeș-Bolyai University, Cluj-Napoca (Romania); Fitzgerald, Edward F. [Department of Epidemiology and Biostatistics, University at Albany, State University of New York, Rensselaer, New York (United States); Department of Environmental Health Sciences, University at Albany, State University of New York, Rensselaer, New York (United States); Anastasiu, Doru [University of Medicine and Pharmacy “Victor Babeș”, Timișoara (Romania); Obstetrics and Gynecology Department of the Emergency County Hospital, Timișoara (Romania); and others

    2017-04-15

    High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiá¹£ County, Romania. Women (n=94) with planned pregnancies of 5–20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1 µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. - Highlights: • We assessed low level drinking water arsenic as a predictor of fecundability. • Arsenic did

  4. Study of the influence of storage conditions on the quality and migration levels of antimony in polyethylene terephthalate-bottled water.

    Science.gov (United States)

    Payán, Luis; Poyatos, M Teresa; Muñoz, Lucía; La Rubia, M Dolores; Pacheco, Rafael; Ramos, Natividad

    2017-06-01

    The main objectives of this study are to determine the presence of antimony in water stored in polyethylene terephthalate bottles and the influence of temperature and time over the migration levels. For this purpose, Sb determination was carried out in water at different experimental conditions: storage for one to three weeks at 25 to 80 ℃; long-term (six months) storage at room temperature between 16 and 24 ℃ and storage in car during summer which is a common consumer's habit. In addition, water quality analysis was developed after different time-temperature storage conditions. All the samples at the end of their storage conditions were analyzed by inductively coupled plasma mass spectrometry. The limit of detection and quantification were 0.50 and 0.80 µg/L, respectively. The results for the bottled water stored during six months indicated that the average Sb concentration was 0.332 ± 0.015 µg/L. This value is below the European maximum permissible migration level of 5 µg/L. With regard to the newly bottled water, no Sb was detected at the initial time for all temperatures studied. However, the Sb concentration in water increased with both time and temperature. The levels of Sb started exceeding the European limits when the samples were stored at 60 ℃ for two weeks.

  5. Determination of activity concentration levels of (238)U, (232)Th, and (40)K in drinking water in a gold mine in Ghana.

    Science.gov (United States)

    Awudu, A R; Darko, E O; Schandorf, C; Hayford, E K; Abekoe, M K; Ofori-Danson, P K

    2010-08-01

    The study of the activity concentration levels of uranium, thorium and potassium in drinking water from different locations in a gold mine in the Ashanti Region of Ghana was conducted using gamma spectrometry. The mean outdoor absorbed gamma dose rates at 1 m from the water were 0.524 nGy h, 0.422 nGy h, and 0.252 nGy h for groundwater, surface water, and treated water, respectively. The results obtained for the activity concentration levels of U and Th are found to be within the maximum acceptable concentration levels of 3.0 Bq L and 0.6 Bq L, respectively, recommended by the World Health Organization. The overall mean outdoor gamma dose rate is 0.41 nGy h and the corresponding outdoor annual effective dose obtained for adult members of the public for drinking water from the mines is 3.58 muSv y. This value is found to be within the 10.0 muSv per annum (0.01 mSv per annum) for public exposure control set by the World Health Organization. Therefore, the mining activities on drinking water studied did not show any significant radiological health implications on the public.

  6. Water level fluctuations in the Congo basin derived from ENVISAT satellite altimetry

    OpenAIRE

    Becker, M.; da Silva, J. S.; Calmant, Stéphane; Robinet, V.; Linguet, L.; Seyler, Frédérique

    2014-01-01

    In the Congo Basin, the elevated vulnerability of food security and the water supply implies that sustainable development strategies must incorporate the effects of climate change on hydrological regimes. However, the lack of observational hydro-climatic data over the past decades strongly limits the number of studies investigating the effects of climate change in the Congo Basin. We present the largest altimetry-based dataset of water levels ever constituted over the entire Congo Basin. This...

  7. Measurement of the heavy water level in the fuel channels of the RA reactor - Annex 11

    International Nuclear Information System (INIS)

    Nikolic, M.

    1964-01-01

    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

  8. Treatability tests on water from a low-level waste burial ground

    International Nuclear Information System (INIS)

    Taylor, P.A.

    1990-01-01

    Lab-scale treatability tests on trench water from a low-level waste burial ground have shown that the water can be successfully treated by existing wastewater treatment plants at Oak Ridge National Laboratory. Water from the four most highly contaminated trenches that had been identified to date was used in the treatability tests. The softening and ion exchange processes used in the Process Wastewater Treatment Plant removed Sr-90 from the trench water, which was the only radionuclide present at above the discharge limits. The air stripping and activated carbon adsorption processes used in the Nonradiological Wastewater Treatment Plant removed volatile and semi-volatile organics, which were the main contaminants in the trench water, to below detection limits. 6 refs., 2 figs., 7 tabs

  9. 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.

  10. Units 3 and 4 steam generators new water level control system

    International Nuclear Information System (INIS)

    Dragoev, D.; Genov, St.

    2001-01-01

    The Steam Generator Water Level Control System is one of the most important for the normal operation systems, related to the safety and reliability of the units. The main upgrading objective for the SG level and SGWLC System modernization is to assure an automatic maintaining of the SG level within acceptable limits (below protections and interlocks) from 0% to 100% of the power in normal operation conditions and in case of transients followed by disturbances in the SG controlled parameters - level, steam flow, feedwater flow and/or pressure/temperature. To achieve this objective, the computerized controllers of new SG water level control system follows current computer control technology and is implemented together with replacement of the feedwater control valves and the needed I and C equipment. (author)

  11. Wave energy level and geographic setting correlate with Florida beach water quality.

    Science.gov (United States)

    Feng, Zhixuan; Reniers, Ad; Haus, Brian K; Solo-Gabriele, Helena M; Kelly, Elizabeth A

    2016-03-15

    Many recreational beaches suffer from elevated levels of microorganisms, resulting in beach advisories and closures due to lack of compliance with Environmental Protection Agency guidelines. We conducted the first statewide beach water quality assessment by analyzing decadal records of fecal indicator bacteria (enterococci and fecal coliform) levels at 262 Florida beaches. The objectives were to depict synoptic patterns of beach water quality exceedance along the entire Florida shoreline and to evaluate their relationships with wave condition and geographic location. Percent exceedances based on enterococci and fecal coliform were negatively correlated with both long-term mean wave energy and beach slope. Also, Gulf of Mexico beaches exceeded the thresholds significantly more than Atlantic Ocean ones, perhaps partially due to the lower wave energy. A possible linkage between wave energy level and water quality is beach sand, a pervasive nonpoint source that tends to harbor more bacteria in the low-wave-energy environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Treating cooling pond water for Wabamun Lake level mitigation project in Alberta

    International Nuclear Information System (INIS)

    Anon

    2004-01-01

    Dealing with the challenge of recharging Wabamun Lake by treating nearby cooling pond water, fed by the North Saskatchewan River, and returning it to the lake, is discussed. To deal with the problem, TransAlta Utilities constructed a treatment plant in 1997 next to the 2,029 MW Sundance power plant to mitigate the effect the power plant's ongoing and historical effect on the lake's water level. The objective of the treatment plant is to treat cooling pond water and return it to the lake to raise water levels there, which have been significantly reduced over the last 25 years mostly by power plant intake, but also by lack of rainfall, surface runoff, and natural evaporation. At the Treatment Facility the water to be treated is first chlorinated to kill zooplankton, algae and bacteria, followed by adjusting the pH using sulfuric acid. Alum coagulant is used to destabilize colour, particles and colloids. The next step is feeding the water to the Actiflo clarifiers which use microsand to provide increased surface area for floc attachment, and to act as ballast. Clarified water from the Actiflo system is then fed to to the Dusenflo filters to remove the largest particles of suspended solids, and through a finer sand media to remove the remaining turbidity, colour and bacteria. Thiosulfate is used in the ozonation system to inactivate any remaining bacteria and zooplankton in the filtered water, before discharging it to the lake. The cooling towers, which are part of the system, ensure that the treated water returned to the lake is kept at a constant temperature, varying no more than three degrees C from the lake water temperature. 3 figs

  13. Monitoring of fluoride and iodide levels in drinking water using ion selective electrodes

    International Nuclear Information System (INIS)

    Ahmed, R.; Viqar-Un-Nisa; Hussain, M.; Tanwir, R.; Qureshi, S.A.

    2004-01-01

    Fluoride and iodide, the most important constituents of drinking water are essential as well as toxic depending on their levels. For their analysis in water mostly ion-selective electrodes, spectrophotometry, titrimetry and coulometry etc; have been used and literature has been briefly reviewed. Ion-selective electrodes offer an efficient method for the measurement of the two halides and were mostly used during this work. Fabrication of these electrodes is briefly described. Comparison of results obtained by ion selective electrode and coulometry is given. Recoveries of the added fluoride ions from the samples were good. A large number of water samples from Rawalpindi-Islamabad area were analyzed for fluoride and iodide. Levels of fluoride and iodide from two main water reservoirs of Rawalpindi and Islamabad are reported before and after treatment. Both surface and ground water samples were analyzed and results are compared and discussed. Some samples from northern areas were also analyzed for iodide and fluoride and compared. Intake of fluoride and iodide from water of different areas is also compared. Water samples, which caused bone deformation in certain areas in Punjab due to excess fluoride, were also analyzed for fluoride and results are presented. (author)

  14. Detection of ultra-low levels of DNA changes by drinking water: epidemiologically important finding.

    Science.gov (United States)

    Kumari, Parmila; Kamiseki, Meiko; Biyani, Manish; Suzuki, Miho; Nemoto, Naoto; Aita, Takuyo; Nishigaki, Koichi

    2015-02-01

    The safety of drinking water is essential to our health. In this context, the mutagenicity of water needs to be checked strictly. However, from the methodological limit, the lower concentration (less than parts per million) of mutagenicity could not be detected, though there have been of interest in the effect of less concentration mutagens. Here, we describe a highly sensitive mutation assay that detects mutagens at the ppb level, termed genome profiling-based mutation assay (GPMA). This consists of two steps; (i) Escherichia coli culture in the medium with/without mutagens and (ii) Genome profiling (GP) method (an integrated method of random PCR, temperature gradient gel electrophoresis and computer-aided normalization). Owing to high sensitivity of this method, very low concentration of mutagens in tap water could be directly detected without introducing burdensome concentration processes, enabling rapid measurement of low concentration samples. Less expectedly, all of the tap waters tested (22 samples) were shown to be significantly mutagenic while mineral waters were not. Resultantly, this article informs two facts that the GPMA method is competent to measure the mutagenicity of waters directly and the experimental results supported the former reports that the city tap waters contain very low level of mutagenicity reagent trihalomethanes. © The Authors 2014. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  15. Effect of Jeju Water on Blood Glucose Levels in Diabetic Patients: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Gwanpyo Koh

    2013-01-01

    Full Text Available Jeju water is the groundwater of Jeju Island, a volcanic island located in Republic of Korea. We investigated whether Jeju water improved glycemic control in patients with diabetes. This was a 12-week single-center, double-blind, randomized, and controlled trial. The subjects daily drank a liter of one of three kinds of water: two Jeju waters (S1 and S2 and Seoul tap water (SS. The primary outcome was the proportion of patients in the per-protocol (PP population achieving glycated hemoglobin (HbA1c < 7.0% at week 12. In total, 196 patients were randomized and analyzed in the intention-to-treat (ITT population (66 consuming S1, 63 consuming S2, and 67 consuming SS; 146 patients were considered in the PP population. There were no significant differences in the primary outcomes of the groups consuming S1, S2, or SS. However, the percentage of patients achieving HbA1c < 8% was significantly higher in the S2 group than in the SS group. In the ITT population, the 12-week HbA1c and fructosamine levels were lo