WorldWideScience

Sample records for net water flow

  1. Net infiltration of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Recharge in the Death Valley regional ground-water flow system (DVRFS) was estimated from net infiltration simulated by Hevesi and others (2003) using a...

  2. Net zero water

    CSIR Research Space (South Africa)

    Lindeque, M

    2013-01-01

    Full Text Available Is it possible to develop a building that uses a net zero amount of water? In recent years it has become evident that it is possible to have buildings that use a net zero amount of electricity. This is possible when the building is taken off...

  3. Communication nets stochastic message flow and delay

    CERN Document Server

    Kleinrock, Leonard

    2007-01-01

    Considerable research has been devoted to the formulation and solution of problems involving flow within connected networks. Independent of these surveys, an extensive body of knowledge has accumulated on the subject of queues, particularly in regard to stochastic flow through single-node servicing facilities. This text combines studies of connected networks with those of stochastic flow, providing a basis for understanding the general behavior and operation of communication networks in realistic situations.Author Leonard Kleinrock of the Computer Science Department at UCLA created the basic p

  4. Software Tool Integrating Data Flow Diagrams and Petri Nets

    Science.gov (United States)

    Thronesbery, Carroll; Tavana, Madjid

    2010-01-01

    Data Flow Diagram - Petri Net (DFPN) is a software tool for analyzing other software to be developed. The full name of this program reflects its design, which combines the benefit of data-flow diagrams (which are typically favored by software analysts) with the power and precision of Petri-net models, without requiring specialized Petri-net training. (A Petri net is a particular type of directed graph, a description of which would exceed the scope of this article.) DFPN assists a software analyst in drawing and specifying a data-flow diagram, then translates the diagram into a Petri net, then enables graphical tracing of execution paths through the Petri net for verification, by the end user, of the properties of the software to be developed. In comparison with prior means of verifying the properties of software to be developed, DFPN makes verification by the end user more nearly certain, thereby making it easier to identify and correct misconceptions earlier in the development process, when correction is less expensive. After the verification by the end user, DFPN generates a printable system specification in the form of descriptions of processes and data.

  5. Translating Colored Control Flow Nets into Readable Java via Annotated Java Workflow Nets

    DEFF Research Database (Denmark)

    Lassen, Kristian Bisgaard; Tjell, Simon

    2007-01-01

    In this paper, we present a method for developing Java applications from Colored Control Flow Nets (CCFNs), which is a special kind of Colored Petri Nets (CPNs) that we introduce. CCFN makes an explicit distinction between the representation of: The system, the environment of the system, and the ......In this paper, we present a method for developing Java applications from Colored Control Flow Nets (CCFNs), which is a special kind of Colored Petri Nets (CPNs) that we introduce. CCFN makes an explicit distinction between the representation of: The system, the environment of the system......, and the interface between the system and the environment. Our translation maps CCFNs into Anno- tated Java Workflow Nets (AJWNs) as an intermediate step, and these AJWNs are finally mapped to Java. CCFN is intended to enforce the modeler to describe the system in an imperative manner which makes the subsequent...... translation to Java easier to define. The translation to Java preserves data dependencies and control-flow aspects of the source CCFN. This paper contributes to the model-driven software development paradigm, by showing how to model a system, environment, and their interface, as a CCFN and presenting a fully...

  6. Detekce provozu Skype pomocí dat NetFlow

    OpenAIRE

    Šebeň, Patrik

    2012-01-01

    NetFlow je sieťový protokol bežne používaný k zberu informácií o IP tokoch. Avšak existuje možnosť, ako použiť tieto zachytené dáta k identifikácií klientov v Skype komunikácií. Táto práca pojednáva o identifikácií určitých vzorov v Skype protokole a ich detekcií v NetFlow dátach. Týmto spôsobom sme schopný identifikovať nódy a supernódy v sieti Skype. NetFlow is a network protocol commonly used for collectiong IP traffic information. But there is a way to use this collected data for inden...

  7. Can net photosynthesis and water relations provide a clue on the ...

    African Journals Online (AJOL)

    Net photosynthesis, sap flow density (SFD) and water use efficiency (WUE) were measured in a Quercus suber forest in north Tunisia in an attempt to explain the forest decline. In general, sap flow was positively related to light intensity and water loss, indicating that high light intensities can increase the SFD up to the ...

  8. Petri net modeling of encrypted information flow in federated cloud

    Science.gov (United States)

    Khushk, Abdul Rauf; Li, Xiaozhong

    2017-08-01

    Solutions proposed and developed for the cost-effective cloud systems suffer from a combination of secure private clouds and less secure public clouds. Need to locate applications within different clouds poses a security risk to the information flow of the entire system. This study addresses this by assigning security levels of a given lattice to the entities of a federated cloud system. A dynamic flow sensitive security model featuring Bell-LaPadula procedures is explored that tracks and authenticates the secure information flow in federated clouds. Additionally, a Petri net model is considered as a case study to represent the proposed system and further validate the performance of the said system.

  9. Measuring Cloud Service Health Using NetFlow/IPFIX

    DEFF Research Database (Denmark)

    Drago, Idilio; Hofstede, Rick; Sadre, Ramin

    2015-01-01

    The increasing trend of outsourcing services to cloud providers is changing the way computing power is delivered to enterprises and end users. Although cloud services offer several advantages, they also make cloud consumers strongly dependent on providers. Hence, consumers have a vital interest...... to be immediately informed about any problems in their services. This paper aims at a first step toward a network-based approach to monitor cloud services. We focus on severe problems that affect most services, such as outages or extreme server overload, and propose a method to monitor these problems that relies...... solely on the traffic exchanged between users and cloud providers. Our proposal is entirely based on NetFlow/IPFIX data and, therefore, explicitly targets high-speed networks. By combining a methodology to reassemble and classify flow records with stochastic estimations, our proposal has the distinct...

  10. Water Flow Experiments

    Indian Academy of Sciences (India)

    This is a simple exercise in elementary fluid dynamics for the undergraduate and the secondary school level. Here, we explore the flow of water through an orifice at the bottom of a cylindri- cal bottle/tank, first through a tube attached to the bottom of the bottle/tank and then without the tube. The experiment is easy to perform.

  11. Water use efficiency of net primary production in global terrestrial ...

    Indian Academy of Sciences (India)

    Water use efficiency; global terrestrial ecosystems; MODIS; net primary production; evapotranspiration;. Köppen–Geiger climate classification. ... Terrestrial plants fix or trap carbon dioxide via photosynthesis to produce the material ...... S W 2007 Evaluating water stress controls on primary production in biogeochemical and ...

  12. Virtual water flows and trade liberalization.

    Science.gov (United States)

    Ramirez-Vallejo, J; Rogers, P

    2004-01-01

    The linkages between agricultural trade and water resources need to be identified and analyzed to better understand the potential impacts that a full liberalization, or lack thereof, will have on water resources. This paper examines trade of virtual water embodied in agricultural products for most countries of the world. The main purpose of the paper, however, is to examine the impact of trade liberalization on virtual-water trade in the future. Based on a simulation of global agricultural trade, a scenario of full liberalization of agriculture was used to assess the net effect of virtual water flows from the relocation of meat and cereals' trade. The paper also identifies the main reasons behind the changes in the magnitude and direction of the net virtual water trade over time, and shows that virtual water trade flows are independent of water resource endowments, contrary to what the Heckscher-Ohlin Theorem states. Finally, based on a formal model, some input demand functions at the country level are estimated. The estimates of the income and agricultural support elasticities of demand for import of virtual water have the expected sign, and are statistically significant. Variables found to have some explanatory power of the variance of virtual water imports are average income; population; agriculture as value added; irrigated area, and exports of goods and services.

  13. Water Sustainability Assessments for Four Net Zero Water Installations

    Science.gov (United States)

    2013-12-01

    Infrastructure Development and Evaluation PVC Polyvinyl Chloride PX Post Exchange QAP Quality Assurance Plan REMIS Real Estate Management Information System...2010. Standard geospatial data layer quality assurance plan ( QAP ): Water line. SDSFIE 2. 6. 1: water_ling. Version 1. 0. 1, September 2010

  14. Mineralizing urban net-zero water treatment: Phase II field ...

    Science.gov (United States)

    Net-zero water (NZW) systems, or water management systems achieving high recycling rates and low residuals generation so as to avoid water import and export, can also conserve energy used to heat and convey water, while economically restoring local eco-hydrology. However, design and operating experience are extremely limited. The objective of this paper is to present the results of the second phase of operation of an advanced oxidation-based NZW pilot system designed, constructed, and operated for a period of two years, serving an occupied four-person apartment. System water was monitored, either continuously or thrice daily, for routine water quality parameters, minerals, and MicroTox® in-vitro toxicity, and intermittently for somatic and male-specific coliphage, adenovirus, Cryptosporidium, Giardia, emerging organic constituents (non-quantitative), and the Florida drinking water standards. All 115 drinking water standards with the exception of bromate were met in this phase. Neither virus nor protozoa were detected in the treated water, with the exception of measurement of adenovirus genome copies attributed to accumulation of inactive genetic material in hydraulic dead zones. Chemical oxygen demand was mineralized to 90% in treatment. Total dissolved solids were maintained at ∼500 mg/L at steady state, partially through aerated aluminum electrocoagulation. Bromate accumulation is projected to be controlled by aluminum electrocoagulation with separate dispo

  15. WaterNet: The NASA water cycle solutions network - Danubian regional applications

    Science.gov (United States)

    Matthews, Dave; Brilly, Mitja; Kobold, Mira; Zagar, Mark; Houser, Paul

    2008-11-01

    WaterNet is a new international network of researchers, stakeholders, and end-users of remote sensing tools that will benefit the water resources management community. This paper provides an overview and it discusses the concept of solutions networks focusing on the WaterNet. It invites Danubian research and applications teams to join our WaterNet network. The NASA Water cycle Solutions Network's goal is to improve and optimize the sustained ability of water cycle researchers, stakeholders, organizations and networks to interact, identify, harness, and extend NASA research results to augment decision support tools and meet national needs. Our team will develop WaterNet by engaging relevant NASA water cycle research resources and community-of-practice organizations, to develop what we term an "actionable database" that can be used to communicate and connect NASA Water cycle research Results (NWRs) towards the improvement of water-related Decision Support Tools (DSTs). Recognizing that the European Commission and European Space Agency have also developed many related Water Research products (EWRs), we seek to learn about these and network with the EU teams to include their information in the WaterNet actionable data base and Community of Practice. WaterNet will then develop strategies to connect researchers and decision-makers via innovative communication strategies, improved user access to NASA and EU - Danubian resources, improved water cycle research community appreciation for user requirements, improved policymaker, management and stakeholder knowledge of research and application products, and improved identification of pathways for progress. Finally, WaterNet will develop relevant benchmarking and metrics, to understand the network's characteristics, to optimize its performance, and to establish sustainability. This paper provides examples of several NASA products based on remote sensing and land data assimilation systems that integrate remotely sensed and in

  16. WaterNet: The NASA water cycle solutions network - Danubian regional applications

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Dave [Hydromet DSS, LLC, Silverthorne, CO 80498-1848 (United States); Brilly, Mitja [FGG University of Ljubljana (Slovenia); Kobold, Mira; Zagar, Mark [Environmental Agency of the Republic of Slovenia, Ljubljana (Slovenia); Houser, Paul [Center for Research on Environment and Water and George Mason University, Calverton, MD 20705 (United States)], E-mail: hydrometdss@comcast.net

    2008-11-01

    WaterNet is a new international network of researchers, stakeholders, and end-users of remote sensing tools that will benefit the water resources management community. This paper provides an overview and it discusses the concept of solutions networks focusing on the WaterNet. It invites Danubian research and applications teams to join our WaterNet network. The NASA Water cycle Solutions Network's goal is to improve and optimize the sustained ability of water cycle researchers, stakeholders, organizations and networks to interact, identify, harness, and extend NASA research results to augment decision support tools and meet national needs. Our team will develop WaterNet by engaging relevant NASA water cycle research resources and community-of-practice organizations, to develop what we term an 'actionable database' that can be used to communicate and connect NASA Water cycle research Results (NWRs) towards the improvement of water-related Decision Support Tools (DSTs). Recognizing that the European Commission and European Space Agency have also developed many related Water Research products (EWRs), we seek to learn about these and network with the EU teams to include their information in the WaterNet actionable data base and Community of Practice. WaterNet will then develop strategies to connect researchers and decision-makers via innovative communication strategies, improved user access to NASA and EU - Danubian resources, improved water cycle research community appreciation for user requirements, improved policymaker, management and stakeholder knowledge of research and application products, and improved identification of pathways for progress. Finally, WaterNet will develop relevant benchmarking and metrics, to understand the network's characteristics, to optimize its performance, and to establish sustainability. This paper provides examples of several NASA products based on remote sensing and land data assimilation systems that integrate

  17. Influence of flowing water

    Science.gov (United States)

    Wirtz, S.; Zell, A.; Wagner, C.; Seeger, M.; Ries, J. B.

    2009-04-01

    In literature authors often state that turbulence is an important or even "the critical" factor for soil erosion. But in erosion modelling the influence of turbulence is largely disregarded until now. The Reynolds number is often used as value of turbulence for a flowing liquid. In technical physics for example it is used to test the viscoelastic behavior of diluted polymer solutions and their elastic instabilities, in hydraulic engineering to characterise flow processes. Single factors that are included into the calculation of the Reynolds number (flow length, flow velocity and liqiud density) are used in many models but not the viscosity. In a study of rill erosion dynamics in Andalusia the Reynolds number is calculated for the collected samples. The scientific question reads as follow: Is there a correlation between turbulence (Reynolds number) and soil erosion (sediment concentration)? And what kind of influence has the turbulence to soil erosion? The factors for calculation of the Reynolds number are the liquid's density, a characteristic flow velocity, a characteristic flow length and the (dynamic) viscosity. The density of the sample is calculated using sediment concentration and the grain density, the flow velocity has been measured in the field experiments and the viscosity is measured by a cone-plate rheometer. For the flow length, a value of 1 meter is used following the assumption that the processes leading to the measured sediment concentrations mainly take place in the last meter before the sampling point. In the study it was ascertained that 1) high flow velocities cause high sediment concentrations and 2) viscosity increase with increasing sediment concentration. So there should be an influence on Reynolds number. Due to the fact that flow velocity is in the numerator and viscosity in the denominator of the Reynolds equation it could be expected that there are two different sections: In one section the Reynolds number increases with increasing

  18. SSH Compromise Detection using NetFlow/IPFIX

    NARCIS (Netherlands)

    Hofstede, R.J.; Hendriks, Luuk; Sperotto, Anna; Pras, Aiko

    2014-01-01

    Flow-based approaches for SSH intrusion detection have been developed to overcome the scalability issues of host-based alternatives. Although the detection of many SSH attacks in a flow-based fashion is fairly straightforward, no insight is typically provided in whether an attack was successful. We

  19. Net Income, Book Value and Cash Flows: The Value Relevance in Jordanian Economic Sectors

    Directory of Open Access Journals (Sweden)

    DHIAA SHAMKI

    2013-07-01

    Full Text Available This paper examines the value relevance of financial statements variables namely net income, book value and cash flows simultaneously relative to Jordanian services and industrial firms for the period from 2000 to 2009. The main findings of this paper are three- dimensional. First, net income is value relevant, while book value and cash flows are irrelevant. Second, net income is more value relevant than book value and cash flows in both sectors. Third, this value relevance is greater in services sector than in industrial sector. The study shows that net income assist more in explaining market values in Jordanian services and industrial firms. Since research on the value relevance of these variables has neglected Jordan (and the Middle Eastern region, the study tries to fill this practical gap. The study is the first in Jordan that examines the value relevance of net income, book value and cash flows simultaneously and compares this value relevance according to Amman Stock Exchange sectors in one study in Jordan.

  20. Community of Practice Applications from WaterNet: The NASA Water Cycle Solutions Network

    Science.gov (United States)

    Matthews, D.; Brilly, M.; Gregoric, G.; Polajnar, J.; Houser, P.; Rodell, M.; Lehning, M.

    2009-04-01

    WaterNet is a new international network of researchers, stakeholders, and end-users of remote sensing tools that will benefit the water resources management community. It addresses a means for enhancing the social and economic developments of nations by increased use of practical research products from the terrestrial water cycle for making informed decisions. This paper provides a summary of the Water Cycle Community of Practice (CoP) plans and examples of Land Surface Model (LSM) applications for extreme events - floods, droughts, and heavy snowstorms in Europe. It discusses the concept of NASA's solutions networks focusing on the WaterNet. It invites EGU teams to join our WaterNet network. The NASA Water cycle Solutions Network's goal is to improve and optimize the sustained ability of water cycle researchers, stakeholders, organizations and networks to interact, identify, harness, and extend NASA research results to augment decision support tools and meet national needs. Our team is developing WaterNet by engaging relevant NASA water cycle research and community-of-practice organizations, to develop what we term an "actionable database" that can be used to communicate and connect NASA Water cycle research Results (NWRs) towards the improvement of water-related Decision Support Tools (DSTs). Recognizing that the European Commission and European Space Agency have also developed many related research products (EWRs), we seek to learn about these and network with the EU teams to include their information in the WaterNet actionable data base. Recognizing the many existing highly valuable water-related science and application networks in the US and EU, we focus the balance of our efforts on enabling their interoperability - facilitating access and communications among decision-makers and scientists. We present results of our initial focus on identification, collection, and analysis of the two end points, these being the NWRs and EWRs and water related DSTs. We

  1. Net profit flow per country from 1980 to 2009 : The long-term effects of foreign direct investment

    NARCIS (Netherlands)

    Akkermans, Dirk H.M.

    2017-01-01

    Aim of the paper The paper aims at describing and explaining net profit flows per country for the period 1980-2009. Net profit flows result from Foreign Direct Investment (FDI) stock and profit repatriation: inward stock creating a profit outflow and outward FDI stock a profit inflow. Profit flows,

  2. Smolt Responses to Hydrodynamic Conditions in Forebay Flow Nets of Surface Flow Outlets, 2007

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Gary E.; Richmond, Marshall C.; Hedgepeth, J. B.; Ploskey, Gene R.; Anderson, Michael G.; Deng, Zhiqun; Khan, Fenton; Mueller, Robert P.; Rakowski, Cynthia L.; Sather, Nichole K.; Serkowski, John A.; Steinbeck, John R.

    2009-04-01

    This study provides information on juvenile salmonid behaviors at McNary and The Dalles dams that can be used by the USACE, fisheries resource managers, and others to support decisions on long-term measures to enhance fish passage. We researched smolt movements and ambient hydrodynamic conditions using a new approach combining simultaneous acoustic Doppler current profiler (ADCP) and acoustic imaging device (AID) measurements at surface flow outlets (SFO) at McNary and The Dalles dams on the Columbia River during spring and summer 2007. Because swimming effort vectors could be computed from the simultaneous fish and flow data, fish behavior could be categorized as passive, swimming against the flow (positively rheotactic), and swimming with the flow (negatively rheotactic). We present bivariate relationships to provide insight into fish responses to particular hydraulic variables that engineers might consider during SFO design. The data indicate potential for this empirical approach of simultaneous water/fish measurements to lead to SFO design guidelines in the future.

  3. The metabolic regimes of flowing waters

    Science.gov (United States)

    Bernhardt, Emily S.; Heffernan, Jim B.; Grimm, Nancy B.; Stanley, Emily H.; Harvey, Judson; Arroita, M.; Appling, Alison; Cohen, M.J.; McDowell, William H.; Hall, R.O.; Read, Jordan S.; Roberts, B.J.; Stets, Edward; Yackulic, Charles B.

    2018-01-01

    The processes and biomass that characterize any ecosystem are fundamentally constrained by the total amount of energy that is either fixed within or delivered across its boundaries. Ultimately, ecosystems may be understood and classified by their rates of total and net productivity and by the seasonal patterns of photosynthesis and respiration. Such understanding is well developed for terrestrial and lentic ecosystems but our understanding of ecosystem phenology has lagged well behind for rivers. The proliferation of reliable and inexpensive sensors for monitoring dissolved oxygen and carbon dioxide is underpinning a revolution in our understanding of the ecosystem energetics of rivers. Here, we synthesize our current understanding of the drivers and constraints on river metabolism, and set out a research agenda aimed at characterizing, classifying and modeling the current and future metabolic regimes of flowing waters.

  4. Report of the Third Workshop on the Usage of NetFlow/IPFIX in Network Management

    NARCIS (Netherlands)

    Drago, Idilio; Sadre, R.; Pras, Aiko

    2011-01-01

    The Network Management Research Group (NMRG) organized in 2010 the Third Workshop on the Usage of NetFlow/IPFIX in Network Management, as part of the 78th IETF Meeting in Maastricht. Yearly organized since 2007, the workshop is an opportunity for people from both academia and industry to discuss the

  5. Water and energy link in the cities of the future - achieving net zero carbon and pollution emissions footprint.

    Science.gov (United States)

    Novotny, V

    2011-01-01

    This article discusses the link between water conservation, reclamation, reuse and energy use as related to the goal of achieving the net zero carbon emission footprint in future sustainable cities. It defines sustainable ecocities and outlines quantitatively steps towards the reduction of energy use due to water and used water flows, management and limits in linear and closed loop water/stormwater/wastewater management systems. The three phase water energy nexus diagram may have a minimum inflection point beyond which reduction of water demand may not result in a reduction of energy and carbon emissions. Hence, water conservation is the best alternative solution to water shortages and minimizing the carbon footprint. A marginal water/energy chart is developed and proposed to assist planners in developing future ecocities and retrofitting older communities to achieve sustainability.

  6. Simulation of Cavitation Water Flows

    Directory of Open Access Journals (Sweden)

    Piroz Zamankhan

    2015-01-01

    Full Text Available The air-water mixture from an artificially aerated spillway flowing down to a canyon may cause serious erosion and damage to both the spillway surface and the environment. The location of an aerator, its geometry, and the aeration flow rate are important factors in the design of an environmentally friendly high-energy spillway. In this work, an analysis of the problem based on physical and computational fluid dynamics (CFD modeling is presented. The numerical modeling used was a large eddy simulation technique (LES combined with a discrete element method. Three-dimensional simulations of a spillway were performed on a graphics processing unit (GPU. The result of this analysis in the form of design suggestions may help diminishing the hazards associated with cavitation.

  7. A net-jet flow system for mass transfer and microsensor studies of sinking aggregates

    DEFF Research Database (Denmark)

    Ploug, H.; Jørgensen, BB

    1999-01-01

    A flow system was developed which enables studies of hydrodynamics and mass transfer in freely sinking aggregates. The aggregates stabilized their positions in the water phase at an upward flow Velocity which balanced and opposed the sinking velocity of the individual aggregate. The flow field...

  8. Using UML and Petri nets for visualization of business document flow

    Directory of Open Access Journals (Sweden)

    Ivana Rábová

    2012-01-01

    Full Text Available The article deals with two principles of business workflow modeling, Petri nets and UML notation, that are the acceptable approaches to business modeling and can be used also for business documents workflow. The special type of Petri nets, WF-nets and UML activity diagrams are used in this article and both modeling ways are presented on the concrete business workflow and then there are presented and specified their advantage and disadvantage for business documents flows. At beginning it is explained the word workflow in context business documents, its features, principles and using in business environment. After that it is clarified that the UML is OMG’s most-used specification, and the way the world models not only application structure, behavior, and architecture, but also business process, workflows and data structure. Activity diagram UML is good way to show how different workflows in the business are managed, how they start, go and stop. Diagrams also show many different decision paths that can be taken from start to finish. State charts can be used as a detail the transitions or changes of states when documents can go through in the business. They show how a documents moves from one state to another and the rules that govern that change. Petri-nets offer a graphical notation for stepwise processes that include choice, iteration, and concurrent execution. Unlike UML Petri nets have an exact mathematical definition of their execution semantics, with a well-developed mathematical theory for process analysis. In the article there are modeled a special type of Petri nets, the WF-nets. The practical part of article incorporates two models of concrete business documents workflows presented in these notations, their comparison and recommendation for using these diagrams in business process management.

  9. Net capital flows to and the real exchange rate of Western Balkan countries

    Directory of Open Access Journals (Sweden)

    Gabrisch Hubert

    2015-01-01

    Full Text Available This paper uses Granger causality tests to assess the linkages between changes in the real exchange rate and net capital inflows using the example of Western Balkan countries, which have suffered from low competitiveness and external imbalances for many years. The real exchange rate is a measure of a country’s price competitiveness, and the paper uses two concepts: relative unit labour cost and relative inflation differential. The sample consists of six Western Balkan countries for the period 1996-2012, relative to the European Union (EU. The main finding is that changes in the net capital flows precede changes in relative unit labour costs and not vice versa. Also, there is evidence that net capital flows affect the inflation differential of countries, although to a less discernible extent. This suggests that the increasing divergence in the unit labour cost between the EU and Western Balkan countries up to the global financial crisis was at least partly the result of net capital inflows. The paper adds to the ongoing debate on improving cost competitiveness through wage restrictions as the main vehicle to avert the accumulation of current account imbalances. It shows the importance of changes in the exchange rate regime, reform of the interaction between the financial and the real sector, and financial supervision and structural change.

  10. An Integrated Model to Compare Net Electricity Generation for Carbon Dioxide- and Water-Based Geothermal Systems

    Science.gov (United States)

    Agarwal, Vikas

    Utilization of supercritical CO2 as a geothermal fluid instead of water has been proposed by Brown in 2000 and its advantages have been discussed by him and other researchers such as Karsten Pruess and Fouillac. This work assesses the net electricity that could be generated by using supercritical CO2 as a geothermal working fluid and compares it with water under the same temperature and pressure reservoir conditions. This procedure provides a method of direct comparison of water and CO2 as geothermal working fluids, in terms of net electricity generation over time given a constant geothermal fluid flow rate. An integrated three-part model has been developed to determine net electricity generation for CO2- and water-based geothermal reservoirs. This model consists of a wellbore model, reservoir simulation, and surface plant simulation. To determine the bottomhole pressure and temperature of the geothermal fluid (either water or CO2) in the injection well, a wellbore model was developed using fluid-phase, thermodynamic equations of state, fluid dynamics, and heat transfer models. A computer program was developed that solves for the temperature and pressure of the working fluid (either water or CO 2) down the wellbore by simultaneously solving for the fluid thermophysical properties, heat transfer, and frictional losses. For the reservoir simulation, TOUGH2, a general purpose numerical simulator has been used to model the temperature and pressure characteristics of the working fluid in the reservoir. The EOS1 module of TOUGH2 has been used for the water system and the EOS2 module of the TOUGH2 code has been employed for the CO2 case. The surface plant is simulated using CHEMCAD, a chemical process simulator, to determine the net electricity generated. A binary organic (iso-pentane) Rankine cycle is simulated. The calculated net electricity generated for the optimized water and CO2 systems are compared over the working time of the reservoir. Based on the theoretical

  11. Mineralizing urban net-zero water treatment: Phase II field results and design recommendations

    Science.gov (United States)

    Net-zero water (NZW) systems, or water management systems achieving high recycling rates and low residuals generation so as to avoid water import and export, can also conserve energy used to heat and convey water, while economically restoring local eco-hydrology. However, design ...

  12. Flow monitoring explained: from packet capture to data analysis with NetFlow and IPFIX

    NARCIS (Netherlands)

    Hofstede, R.J.; Celeda, Pavel; Trammell, Brian; Drago, Idilio; Sadre, R.; Sperotto, Anna; Pras, Aiko

    2014-01-01

    Flow monitoring has become a prevalent method for monitoring traffic in high-speed networks. By focusing on the analysis of flows, rather than individual packets, it is often said to be more scalable than traditional packet-based traffic analysis. Flow monitoring embraces the complete chain of

  13. Irrigation Alternatives to Meet Army Net Zero Water Goals

    Science.gov (United States)

    2012-05-01

    water requirements and natural precipitation.  Use native or “climate-appropriate” material  Can reduce irrigation water by 50%, stands up better...Design plant groupings based on similar water requirements and rooting depths (hydrozoning)  Design with water use efficiency, potential for water

  14. Comparability of slack water and Lagrangian flow respirometry methods for community metabolic measurements.

    Directory of Open Access Journals (Sweden)

    Emily C Shaw

    Full Text Available Coral reef calcification is predicted to decline as a result of ocean acidification and other anthropogenic stressors. The majority of studies predicting declines based on in situ relationships between environmental parameters and net community calcification rate have been location-specific, preventing accurate predictions for coral reefs globally. In this study, net community calcification and production were measured on a coral reef flat at One Tree Island, Great Barrier Reef, using Lagrangian flow respirometry and slack water methods. Net community calcification, daytime net photosynthesis and nighttime respiration were higher under the flow respirometry method, likely due to increased water flow relative to the slack water method. The two methods also varied in the degrees to which they were influenced by potential measurement uncertainties. The difference in the results from these two commonly used methods implies that some of the location-specific differences in coral reef community metabolism may be due to differences in measurement methods.

  15. Review of oil water core annular flow

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, S.; Mandal, T.K.; Das, G. [Department of Chemical Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Das, P.K. [Department of Mechanical Engineering, Indian Institute of Technology, Kharagpur 721302 (India)

    2009-10-15

    The emerging energy efficient technology in the field of high viscous oil transportation is water-lubricated transport of heavy oil, known as core annular flow or CAF. This paper provides a brief review of the past studies on oil-water core annular flows - including studies on hydrodynamics as well as stability of flow. (author)

  16. The influence of fish culture in floating net cages on microbial indicators of water quality

    National Research Council Canada - National Science Library

    Gorlach-Lira, K; Pacheco, C; Carvalho, L C T; Melo Júnior, H N; Crispim, M C

    2013-01-01

    ... (Oreochromis niloticus) in floating net cages. The physico-chemical parameters, counts of mesophilic total aerobic bacteria, total and thermotolerant coliforms and fecal streptococci, and the presence of Escherichia coli in samples of water...

  17. Water use efficiency of net primary production in global terrestrial ...

    Indian Academy of Sciences (India)

    The carbon and water cycles of terrestrial ecosystems, which are strongly coupled via water use efficiency (WUE), are influenced by global climate change. To explore the relationship between the carbon and water cycles and predict the effect of climate change on terrestrial ecosystems, it is necessary to study the WUE in ...

  18. Constant-net-time headway as a key mechanism behind pedestrian flow dynamics.

    Science.gov (United States)

    Johansson, Anders

    2009-08-01

    We show that keeping a constant lower limit on the net-time headway is the key mechanism behind the dynamics of pedestrian streams. There is a large variety in flow and speed as functions of density for empirical data of pedestrian streams obtained from studies in different countries. The net-time headway, however, stays approximately constant over all these different data sets. By using this fact, we demonstrate how the underlying dynamics of pedestrian crowds, naturally follows from local interactions. This means that there is no need to come up with an arbitrary fit function (with arbitrary fit parameters) as has traditionally been done. Further, by using not only the average density values but the variance as well, we show how the recently reported stop-and-go waves [Helbing, Phys. Rev. E 75, 046109 (2007)] emerge when local density variations take values exceeding a certain maximum global (average) density, which makes pedestrians stop.

  19. The Perspective on Data and Control Flow Analysis in Topological Functioning Models by Petri Nets

    Directory of Open Access Journals (Sweden)

    Asnina Erika

    2014-12-01

    Full Text Available The perspective on integration of two mathematical formalisms, i.e., Colored Petri Nets (CPNs and Topological Functioning Model (TFM, is discussed in the paper. The roots of CPNs are in modeling system functionality. The TFM joins principles of system theory and algebraic topology, and formally bridges the solution domain with the problem domain. It is a base for further automated construction of software design models. The paper discusses a perspective on check of control and data flows in the TFM by CPNs formalism. The research result is definition of mappings from TFMs to CPNs.

  20. Net ecosystem productivity, net primary productivity and ecosystem carbon sequestration in a Pinus radiata plantation subject to soil water deficit

    Energy Technology Data Exchange (ETDEWEB)

    Arneth, A.; Kelleher, F. M. [Lincoln Univ., Soil Sience Dept., Lincoln, (New Zealand); McSeveny, T. M. [Manaaki Whenua-Landcare Research, Lincoln, (New Zealand); Byers, J. N. [Almuth Arneth Landcare Research, Lincoln (New Zealand)

    1998-12-01

    Tree carbon uptake (net primary productivity excluding fine root turnover, NPP`) in pine trees growing in a region of New Zealand subject to summer soil water deficit was investigated jointly with canopy assimilation (A{sub c}) and ecosystem-atmosphere carbon exchange rate (net ecosystem productivity, NEP). Canopy assimilation and NEP were used to drive a biochemically-based and environmentally constrained model validated by seasonal eddy covariance measurements. Over a three year period with variable rainfall annual NPP` and NEP showed significant variations. At the end of the growing season, carbon was mostly allocated to wood, with nearly half to stems and about a quarter to coarse roots. On a biweekly basis NPP` lagged behind A{sub c}, suggesting the occurrence of intermediate carbon storage. On an annual basis, however the NPP`/A{sub c} ratio indicated a conservative allocation of carbon to autotrophic respiration. The combination of data from measurements with canopy and ecosystem carbon fluxes yielded an estimate of heterotrophic respiration (NPP`-NEP) of approximately 30 per cent of NPP` and 50 per cent NEP. The annual values of NEP and NPP` can also be used to derive a `best guess` estimate of the annual below-ground carbon turnover rate, assuming that the annual changes in the soil carbon content is negligible. 46 refs., 7 figs.

  1. Morphometric methods for simulation of water flow

    NARCIS (Netherlands)

    Booltink, H.W.G.

    1993-01-01

    Water flow in structured soils is strongly governed by the occurence of macropores. In this study emphasis was given to combined research of morphology of water- conducting macropores and soil physical measurements on bypass flow. Main research objectives were to: (i) develop and improve

  2. TIGER-NET – enabling an Earth Observation capacity for Integrated Water Resource Management in Africa

    DEFF Research Database (Denmark)

    Walli, A.; Tøttrup, C.; Naeimi, V.

    As part of the TIGER initiative [1] the TIGER-NET project aims to support the assessment and monitoring of water resources from watershed to transboundary basin level delivering indispensable information for Integrated Water Resource Management in Africa through: 1. Development of an open-source ...

  3. Petri Nets Based Modelling of Control Flow for Memory-Aid Interactive Programs in Telemedicine

    CERN Document Server

    Khoromskaia, V K

    2004-01-01

    Petri Nets (PN) based modelling of the control flow for the interactive memory assistance programs designed for personal pocket computers and having special requirements for robustness is considered. The proposed concept allows one to elaborate the programs which can give users a variety of possibilities for a day-time planning in the presence of environmental and time restrictions. First, a PN model for a known simple algorithm is constructed and analyzed using the corresponding state equations and incidence matrix. Then a PN graph for a complicated algorithm with overlapping actions and choice possibilities is designed, supplemented by an example of its analysis. Dynamic behaviour of this graph is tested by tracing of all possible paths of the flow of control using the PN simulator. It is shown that PN based modelling provides reliably predictable performance of interactive algorithms with branched structures and concurrency requirements.

  4. A regional and multi-faceted approach to postgraduate water education - the WaterNet experience in Southern Africa

    Science.gov (United States)

    Jonker, L.; van der Zaag, P.; Gumbo, B.; Rockström, J.; Love, D.; Savenije, H. H. G.

    2012-11-01

    This paper reports the experience of a regional network of academic departments involved in water education that started as a project and evolved, over a period of 12 yr, into an independent network organisation. The paper pursues three objectives. First, it argues that it makes good sense to organise postgraduate education and research on water resources on a regional scale and presents the WaterNet experience as an example that a regional approach can work. Second, it presents preliminary findings and conclusions that the regional approach presented by WaterNet did make a contribution to the capacity needs of the region both in terms of management and research capacity. Third, it draws two generalised lessons from the WaterNet experience. Lesson one pertains to the importance of legitimate ownership and an accountability structure for network effectiveness. Lesson two is related to the financial and intellectual resources required to jointly developing educational programmes through shared experience.

  5. Observations on the decay of a thermocline in a rock bed with no net fluid flow

    Energy Technology Data Exchange (ETDEWEB)

    Beasley, D.E.; Clark, J.A.; Holstege, M.J.

    1985-02-01

    The transient thermal response of a rock bed with no net fluid flow is examined following all-day charging under clear sky conditions. The experimental system consists of 1.86 m/sup 2/ (20 ft/sup 2/) of flat-plate solar collectors using air as the working fluid, a flow control system, and a 0.357 m/sup 3/ (12.6 ft/sup 3/) rock bed for thermal energy storage. A thermocline is established in the bed during charging due to the timevarying nature of the collector outlet temperature. Experimental measurements of the temperature distribution in the bed for a 13-hour stagnation period allow a preliminary estimate of the loss of available energy in the storage medium. The net loss in thermodynamic availability is 30 percent. Since the temperatures in the upper regions of the bed are lower than those in the central regions at the end of charging under clear sky conditions, the possibility of natural convection motion of the fluid in the bed exists. An ''apparent'' local thermal diffusivity is calculated and from comparison with stagnant bed values indicates that natural convection motion may occur in the upper regions of the bed.

  6. Protecting environmental flows through enhanced water licensing and water markets

    Science.gov (United States)

    Erfani, T.; Binions, O.; Harou, J. J.

    2015-02-01

    To enable economically efficient future adaptation to water scarcity some countries are revising water management institutions such as water rights or licensing systems to more effectively protect ecosystems and their services. However, allocating more flow to the environment can mean less abstraction for economic production, or the inability to accommodate new entrants (diverters). Modern licensing arrangements should simultaneously enhance environmental flows and protect water abstractors who depend on water. Making new licensing regimes compatible with tradable water rights is an important component of water allocation reform. Regulated water markets can help decrease the societal cost of water scarcity whilst enforcing environmental and/or social protections. In this article we simulate water markets under a regime of fixed volumetric water abstraction licenses with fixed minimum flows or under a scalable water license regime (using water "shares") with dynamic environmental minimum flows. Shares allow adapting allocations to available water and dynamic environmental minimum flows vary as a function of ecological requirements. We investigate how a short-term spot market manifests within each licensing regime. We use a river-basin-scale hydroeconomic agent model that represents individual abstractors and can simulate a spot market under both licensing regimes. We apply this model to the Great Ouse River basin in eastern England with public water supply, agricultural, energy and industrial water-using agents. Results show the proposed shares with dynamic environmental flow licensing system protects river flows more effectively than the current static minimum flow requirements during a dry historical year, but that the total opportunity cost to water abstractors of the environmental gains is a 10-15% loss in economic benefits.

  7. UV sensitivity of planktonic net community production in ocean surface waters

    OpenAIRE

    Regaudie de Gioux, Aurore; Agustí, Susana; Duarte, Carlos M.

    2014-01-01

    The net plankton community metabolism of oceanic surface waters is particularly important as it more directly affects the partial pressure of CO2 in surface waters and thus the air-sea fluxes of CO2. Plankton communities in surface waters are exposed to high irradiance that includes significant ultraviolet blue (UVB, 280-315 nm) radiation. UVB radiation affects both photosynthetic and respiration rates, increase plankton mortality rates, and other metabolic and chemical processes. Here we tes...

  8. Three Principles of Water Flow in Soils

    Science.gov (United States)

    Guo, L.; Lin, H.

    2016-12-01

    Knowledge of water flow in soils is crucial to understanding terrestrial hydrological cycle, surface energy balance, biogeochemical dynamics, ecosystem services, contaminant transport, and many other Critical Zone processes. However, due to the complex and dynamic nature of non-uniform flow, reconstruction and prediction of water flow in natural soils remain challenging. This study synthesizes three principles of water flow in soils that can improve modeling water flow in soils of various complexity. The first principle, known as the Darcy's law, came to light in the 19th century and suggested a linear relationship between water flux density and hydraulic gradient, which was modified by Buckingham for unsaturated soils. Combining mass balance and the Buckingham-Darcy's law, L.A. Richards quantitatively described soil water change with space and time, i.e., Richards equation. The second principle was proposed by L.A. Richards in the 20th century, which described the minimum pressure potential needed to overcome surface tension of fluid and initiate water flow through soil-air interface. This study extends this principle to encompass soil hydrologic phenomena related to varied interfaces and microscopic features and provides a more cohesive explanation of hysteresis, hydrophobicity, and threshold behavior when water moves through layered soils. The third principle is emerging in the 21st century, which highlights the complex and evolving flow networks embedded in heterogeneous soils. This principle is summarized as: Water moves non-uniformly in natural soils with a dual-flow regime, i.e., it follows the least-resistant or preferred paths when "pushed" (e.g., by storms) or "attracted" (e.g., by plants) or "restricted" (e.g., by bedrock), but moves diffusively into the matrix when "relaxed" (e.g., at rest) or "touched" (e.g., adsorption). The first principle is a macroscopic view of steady-state water flow, the second principle is a microscopic view of interface

  9. UV sensitivity of planktonic net community production in ocean surface waters

    Science.gov (United States)

    Regaudie-de-Gioux, Aurore; Agustí, Susana; Duarte, Carlos M.

    2014-05-01

    The net plankton community metabolism of oceanic surface waters is particularly important as it more directly affects the partial pressure of CO2 in surface waters and thus the air-sea fluxes of CO2. Plankton communities in surface waters are exposed to high irradiance that includes significant ultraviolet blue (UVB, 280-315 nm) radiation. UVB radiation affects both photosynthetic and respiration rates, increase plankton mortality rates, and other metabolic and chemical processes. Here we test the sensitivity of net community production (NCP) to UVB of planktonic communities in surface waters across contrasting regions of the ocean. We observed here that UVB radiation affects net plankton community production at the ocean surface, imposing a shift in NCP by, on average, 50% relative to the values measured when excluding partly UVB. Our results show that under full solar radiation, the metabolic balance shows the prevalence of net heterotrophic community production. The demonstration of an important effect of UVB radiation on NCP in surface waters presented here is of particular relevance in relation to the increased UVB radiation derived from the erosion of the stratospheric ozone layer. Our results encourage design future research to further our understanding of UVB effects on the metabolic balance of plankton communities.

  10. Net profit flow per country from 1980 to 2009: The long-term effects of foreign direct investment

    Science.gov (United States)

    2017-01-01

    Aim of the paper The paper aims at describing and explaining net profit flows per country for the period 1980–2009. Net profit flows result from Foreign Direct Investment (FDI) stock and profit repatriation: inward stock creating a profit outflow and outward FDI stock a profit inflow. Profit flows, especially ‘normal’ ones are not commonly researched. Theoretical background According to world-system theory, countries are part of a system characterised by a core, semi-periphery and periphery, as shown by network analyses of trade relations. Network analyses based on ownership relations of TransNational Corporations (TNCs) show that the top 50 firms that control about 40% of the world economy are almost exclusively located in core countries. So, we may expect a hierarchy in net profit flows with core countries on top and the periphery at the bottom. FDI outflows from the core countries especially rose in the 1990s, so we may expect that the difference has grown in time. Data and results A dataset on 'net profit flow' per country is developed. There are diverging developments in net profit flows since the 1980s, as expected: ever more positive for core countries, negative and ever lower for semi-peripheral and peripheral countries, in particular from the 1990s onwards. A fixed effects quantile regression using publicly available data confirms the prediction that peripheral countries share a unique characteristic: their outward investments do not have a positive influence on net profit flow as is the case with semi-peripheral and core countries. The most probable explanation is that peripheral outward investments are indirectly owned by firms located in core and semi-peripheral countries, so all peripheral profit inflows end up in those countries. PMID:28654644

  11. Net profit flow per country from 1980 to 2009: The long-term effects of foreign direct investment.

    Science.gov (United States)

    Akkermans, Dirk H M

    2017-01-01

    The paper aims at describing and explaining net profit flows per country for the period 1980-2009. Net profit flows result from Foreign Direct Investment (FDI) stock and profit repatriation: inward stock creating a profit outflow and outward FDI stock a profit inflow. Profit flows, especially 'normal' ones are not commonly researched. According to world-system theory, countries are part of a system characterised by a core, semi-periphery and periphery, as shown by network analyses of trade relations. Network analyses based on ownership relations of TransNational Corporations (TNCs) show that the top 50 firms that control about 40% of the world economy are almost exclusively located in core countries. So, we may expect a hierarchy in net profit flows with core countries on top and the periphery at the bottom. FDI outflows from the core countries especially rose in the 1990s, so we may expect that the difference has grown in time. A dataset on 'net profit flow' per country is developed. There are diverging developments in net profit flows since the 1980s, as expected: ever more positive for core countries, negative and ever lower for semi-peripheral and peripheral countries, in particular from the 1990s onwards. A fixed effects quantile regression using publicly available data confirms the prediction that peripheral countries share a unique characteristic: their outward investments do not have a positive influence on net profit flow as is the case with semi-peripheral and core countries. The most probable explanation is that peripheral outward investments are indirectly owned by firms located in core and semi-peripheral countries, so all peripheral profit inflows end up in those countries.

  12. TIGER-NET- Enabling An Earth Observation Capacity For Integrated Water Resource Management In Africa

    Science.gov (United States)

    Walli, A.; Tøttrup, C.; Naeimi, V.; Bauer-Gottwein, P.; Bila, M.; Mufeti, P.; Tumbulto, J. W.; Rajah, C.; Moloele, LS.; Koetz, B.

    2013-12-01

    As part of the TIGER initiative [1] the TIGER-NET project aims to support the assessment and monitoring of water resources from watershed to transboundary basin level delivering indispensable information for Integrated Water Resource Management in Africa through: 1. Development of an open-source Water Observation and Information Systems (WOIS) for monitoring, assessing and inventorying water resources in a cost- effective manner; 2. Capacity building and training of African water authorities and technical centers to fully exploit the increasing observation capacity offered by current and upcoming generations of satellites, including the Sentinel missions. Dedicated application case studies have been developed and demonstrated covering all EO products required by and developed with the participating African water authorities for their water resource management tasks, such as water reservoir inventory, water quality monitoring, water demand planning as well as flood forecasting and monitoring.

  13. Building waste management core indicators through Spatial Material Flow Analysis: net recovery and transport intensity indexes.

    Science.gov (United States)

    Font Vivanco, David; Puig Ventosa, Ignasi; Gabarrell Durany, Xavier

    2012-12-01

    In this paper, the material and spatial characterization of the flows within a municipal solid waste (MSW) management system are combined through a Network-Based Spatial Material Flow Analysis. Using this information, two core indicators are developed for the bio-waste fraction, the Net Recovery Index (NRI) and the Transport Intensity Index (TII), which are aimed at assessing progress towards policy-related sustainable MSW management strategies and objectives. The NRI approaches the capacity of a MSW management system for converting waste into resources through a systematic metabolic approach, whereas the TII addresses efficiency in terms of the transport requirements to manage a specific waste flow throughout the entire MSW management life cycle. Therefore, both indicators could be useful in assessing key MSW management policy strategies, such as the consecution of higher recycling levels (sustainability principle) or the minimization of transport by locating treatment facilities closer to generation sources (proximity principle). To apply this methodological approach, the bio-waste management system of the region of Catalonia (Spain) has been chosen as a case study. Results show the adequacy of both indicators for identifying those points within the system with higher capacity to compromise its environmental, economic and social performance and therefore establishing clear targets for policy prioritization. Moreover, this methodological approach permits scenario building, which could be useful in assessing the outcomes of hypothetical scenarios, thus proving its adequacy for strategic planning. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. A simple flow-concentration modelling method for integrating water ...

    African Journals Online (AJOL)

    National Water Act, 1998), flow requirements are assessed for maintenance low flow, drought low flow and flood conditions. Since water quantity and water quality are often closely linked, it is necessary to ensure that in setting the recommended ...

  15. An experimental investigation of flows from zero-net mass-flux actuators

    Science.gov (United States)

    Holman, Ryan Jay

    Zero-net mass-flux (ZNMF) devices consist of an oscillating driver, a cavity, and a small opening such as a rectangular slot or a circular orifice. The driver produces a series of vortex pairs (or rings) at the slot/orifice which add momentum and circulation to the flow. ZNMF devices are useful tools for flow control applications such as heat transfer, mixing enhancement, and boundary layer separation control. To date much research has been done to qualify and quantify the effects of ZNMF devices in many applications, both experimental and computational. However, a number of issues still remain. First, there is no universally accepted dimensionless parameter space, which makes device characterization and comparison between studies difficult. Second, most experimental studies do not sufficiently quantify the nearfield behavior, which hinders the fundamental understanding of the underlying flow physics. Of particular interest are the regimes of jet formation, and transition from laminar to turbulent-like flow, which are not well understood. Finally, the accuracy of experimental measurements are seldom reported in the literature. This study unifies the experimental and numerical data presented in the literature for ZNMF flowfields exhausting into a quiescent medium. A quantitative experimental database is also generated to completely characterize the topological regions of ZNMF flows over a useful range of the dimensionless parameter space. The database is derived chiefly from two-dimensional velocity field measurements using particle image velocimetry and laser Doppler anemometry. Vorticity, circulation, Reynolds stress, and turbulent kinetic energy is acquired to characterize the resulting flowfield. Significant insight into the behavior of voice coil driven ZNMF devices is uncovered. Design improvements are made by implementing a sinusoidal controller for piston motion and eliminating the need for a sealing membrane in the cavity. It is shown that the proper

  16. Water flow at all scales

    DEFF Research Database (Denmark)

    Sand-Jensen, K.

    2006-01-01

    Continuous water fl ow is a unique feature of streams and distinguishes them from all other ecosystems. The main fl ow is always downstream but it varies in time and space and can be diffi cult to measure and describe. The interest of hydrologists, geologists, biologists and farmers in water fl ow......, and its physical impact, depends on whether the main focus is on the entire stream system, the adjacent fi elds, the individual reaches or the habitats of different species. It is important to learn how to manage fl ow at all scales, in order to understand the ecology of streams and the biology...

  17. Building waste management core indicators through Spatial Material Flow Analysis: Net recovery and transport intensity indexes

    Energy Technology Data Exchange (ETDEWEB)

    Font Vivanco, David, E-mail: font@cml.leidenuniv.nl [Institut de Ciencia i Tecnologia Ambientals (ICTA), Departament d' Enginyeria Quimica, Universitat Autonoma de Barcelona (UAB), 08193 Bellaterra, Barcelona (Spain); Institute of Environmental Sciences (CML), Leiden University, P.O. Box 9518, 2300 RA Leiden (Netherlands); Puig Ventosa, Ignasi [ENT Environment and Management, Carrer Sant Joan 39, First Floor, 08800 Vilanova i la Geltru, Barcelona (Spain); Gabarrell Durany, Xavier [Institut de Ciencia i Tecnologia Ambientals (ICTA), Departament d' Enginyeria Quimica, Universitat Autonoma de Barcelona (UAB), 08193 Bellaterra, Barcelona (Spain)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Sustainability and proximity principles have a key role in waste management. Black-Right-Pointing-Pointer Core indicators are needed in order to quantify and evaluate them. Black-Right-Pointing-Pointer A systematic, step-by-step approach is developed in this study for their development. Black-Right-Pointing-Pointer Transport may play a significant role in terms of environmental and economic costs. Black-Right-Pointing-Pointer Policy action is required in order to advance in the consecution of these principles. - Abstract: In this paper, the material and spatial characterization of the flows within a municipal solid waste (MSW) management system are combined through a Network-Based Spatial Material Flow Analysis. Using this information, two core indicators are developed for the bio-waste fraction, the Net Recovery Index (NRI) and the Transport Intensity Index (TII), which are aimed at assessing progress towards policy-related sustainable MSW management strategies and objectives. The NRI approaches the capacity of a MSW management system for converting waste into resources through a systematic metabolic approach, whereas the TII addresses efficiency in terms of the transport requirements to manage a specific waste flow throughout the entire MSW management life cycle. Therefore, both indicators could be useful in assessing key MSW management policy strategies, such as the consecution of higher recycling levels (sustainability principle) or the minimization of transport by locating treatment facilities closer to generation sources (proximity principle). To apply this methodological approach, the bio-waste management system of the region of Catalonia (Spain) has been chosen as a case study. Results show the adequacy of both indicators for identifying those points within the system with higher capacity to compromise its environmental, economic and social performance and therefore establishing clear targets for policy

  18. Why a regional approach to postgraduate water education makes sense - the WaterNet experience in Southern Africa

    Science.gov (United States)

    Jonker, L.; van der Zaag, P.; Gumbo, B.; Rockström, J.; Love, D.; Savenije, H. H. G.

    2012-03-01

    This paper reports the experience of a regional network of academic departments involved in water education that started as a project and evolved, over a period of 12 yr, into an independent network organisation. The paper pursues three objectives. First, it argues that it makes good sense to organise postgraduate education and research on water resources on a regional scale. This is because water has a transboundary dimension that poses delicate sharing questions, an approach that promotes a common understanding of what the real water-related issues are, results in future water specialists speaking a common (water) language, enhances mutual respect, and can thus be considered an investment in future peace. Second, it presents the WaterNet experience as an example that a regional approach can work and has an impact. Third, it draws three generalised lessons from the WaterNet experience. Lesson 1: For a regional capacity building network to be effective, it must have a legitimate ownership structure and a clear mandate. Lesson 2: Organising water-related training opportunities at a regional and transboundary scale makes sense - not only because knowledge resources are scattered, but also because the topic - water - has a regional and transboundary scope. Lesson 3: Jointly developing educational programmes by sharing expertise and resources requires intense intellectual management and sufficient financial means.

  19. Atlantic water flow through the Faroese Channels

    Directory of Open Access Journals (Sweden)

    B. Hansen

    2017-11-01

    Full Text Available Through the Faroese Channels – the collective name for a system of channels linking the Faroe–Shetland Channel, Wyville Thomson Basin, and Faroe Bank Channel – there is a deep flow of cold waters from Arctic regions that exit the system as overflow through the Faroe Bank Channel and across the Wyville Thomson Ridge. The upper layers, in contrast, are dominated by warm, saline water masses from the southwest, termed Atlantic water. In spite of intensive research over more than a century, there are still open questions on the passage of these waters through the system with conflicting views in recent literature. Of special note is the suggestion that there is a flow of Atlantic water from the Faroe–Shetland Channel through the Faroe Bank Channel, which circles the Faroes over the slope region in a clockwise direction. Here, we combine the observational evidence from ship-borne hydrography, moored current measurements, surface drifter tracks, and satellite altimetry to address these questions and propose a general scheme for the Atlantic water flow through this channel system. We find no evidence for a continuous flow of Atlantic water from the Faroe–Shetland Channel to the Faroe Bank Channel over the Faroese slope. Rather, the southwestward-flowing water over the Faroese slope of the Faroe–Shetland Channel is totally recirculated within the combined area of the Faroe–Shetland Channel and Wyville Thomson Basin, except possibly for a small release in the form of eddies. This does not exclude a possible westward flow over the southern tip of the Faroe Shelf, but even including that, we estimate that the average volume transport of a Circum-Faroe Current does not exceed 0.5 Sv (1 Sv  =  106 m3 s−1. Also, there seems to be a persistent flow of Atlantic water from the western part of the Faroe Bank Channel into the Faroe–Shetland Channel that joins the Slope Current over the Scottish slope. These conclusions will affect

  20. Atlantic water flow through the Faroese Channels

    Science.gov (United States)

    Hansen, Bogi; Poulsen, Turið; Margretha Húsgarð Larsen, Karin; Hátún, Hjálmar; Østerhus, Svein; Darelius, Elin; Berx, Barbara; Quadfasel, Detlef; Jochumsen, Kerstin

    2017-11-01

    Through the Faroese Channels - the collective name for a system of channels linking the Faroe-Shetland Channel, Wyville Thomson Basin, and Faroe Bank Channel - there is a deep flow of cold waters from Arctic regions that exit the system as overflow through the Faroe Bank Channel and across the Wyville Thomson Ridge. The upper layers, in contrast, are dominated by warm, saline water masses from the southwest, termed Atlantic water. In spite of intensive research over more than a century, there are still open questions on the passage of these waters through the system with conflicting views in recent literature. Of special note is the suggestion that there is a flow of Atlantic water from the Faroe-Shetland Channel through the Faroe Bank Channel, which circles the Faroes over the slope region in a clockwise direction. Here, we combine the observational evidence from ship-borne hydrography, moored current measurements, surface drifter tracks, and satellite altimetry to address these questions and propose a general scheme for the Atlantic water flow through this channel system. We find no evidence for a continuous flow of Atlantic water from the Faroe-Shetland Channel to the Faroe Bank Channel over the Faroese slope. Rather, the southwestward-flowing water over the Faroese slope of the Faroe-Shetland Channel is totally recirculated within the combined area of the Faroe-Shetland Channel and Wyville Thomson Basin, except possibly for a small release in the form of eddies. This does not exclude a possible westward flow over the southern tip of the Faroe Shelf, but even including that, we estimate that the average volume transport of a Circum-Faroe Current does not exceed 0.5 Sv (1 Sv = 106 m3 s-1). Also, there seems to be a persistent flow of Atlantic water from the western part of the Faroe Bank Channel into the Faroe-Shetland Channel that joins the Slope Current over the Scottish slope. These conclusions will affect potential impacts from offshore activities in the

  1. Pattern Extraction Algorithm for NetFlow-Based Botnet Activities Detection

    Directory of Open Access Journals (Sweden)

    Rafał Kozik

    2017-01-01

    Full Text Available As computer and network technologies evolve, the complexity of cybersecurity has dramatically increased. Advanced cyber threats have led to current approaches to cyber-attack detection becoming ineffective. Many currently used computer systems and applications have never been deeply tested from a cybersecurity point of view and are an easy target for cyber criminals. The paradigm of security by design is still more of a wish than a reality, especially in the context of constantly evolving systems. On the other hand, protection technologies have also improved. Recently, Big Data technologies have given network administrators a wide spectrum of tools to combat cyber threats. In this paper, we present an innovative system for network traffic analysis and anomalies detection to utilise these tools. The systems architecture is based on a Big Data processing framework, data mining, and innovative machine learning techniques. So far, the proposed system implements pattern extraction strategies that leverage batch processing methods. As a use case we consider the problem of botnet detection by means of data in the form of NetFlows. Results are promising and show that the proposed system can be a useful tool to improve cybersecurity.

  2. A process to estimate net infiltration using a site-scale water-budget approach, Rainier Mesa, Nevada National Security Site, Nevada, 2002–05

    Science.gov (United States)

    Smith, David W.; Moreo, Michael T.; Garcia, C. Amanda; Halford, Keith J.; Fenelon, Joseph M.

    2017-08-29

    This report documents a process used to estimate net infiltration from precipitation, evapotranspiration (ET), and soil data acquired at two sites on Rainier Mesa. Rainier Mesa is a groundwater recharge area within the Nevada National Security Site where recharged water flows through bedrock fractures to a deep (450 meters) water table. The U.S. Geological Survey operated two ET stations on Rainier Mesa from 2002 to 2005 at sites characterized by pinyon-juniper and scrub-brush vegetative cover. Precipitation and ET data were corrected to remove measurement biases and gap-filled to develop continuous datasets. Net infiltration (percolation below the root zone) and changes in root-zone water storage were estimated using a monthly water-balance model.Site-scale water-budget results indicate that the heavily-fractured welded-tuff bedrock underlying thin (<40 centimeters) topsoil is a critical water source for vegetation during dry periods. Annual precipitation during the study period ranged from fourth lowest (182 millimeters [mm]) to second highest (708 mm) on record (record = 55 years). Annual ET exceeded precipitation during dry years, indicating that the fractured-bedrock reservoir capacity is sufficient to meet atmospheric-evaporative demands and to sustain vegetation through extended dry periods. Net infiltration (82 mm) was simulated during the wet year after the reservoir was rapidly filled to capacity. These results support previous conclusions that preferential fracture flow was induced, resulting in an episodic recharge pulse that was detected in nearby monitoring wells. The occurrence of net infiltration only during the wet year is consistent with detections of water-level rises in nearby monitoring wells that occur only following wet years.

  3. Water-in-Water Droplets by Passive Microfluidic Flow Focusing.

    Science.gov (United States)

    Moon, Byeong-Ui; Abbasi, Niki; Jones, Steven G; Hwang, Dae Kun; Tsai, Scott S H

    2016-04-05

    We present a simple microfluidic system that generates water-in-water, aqueous two phase system (ATPS) droplets, by passive flow focusing. ATPS droplet formation is achieved by applying weak hydrostatic pressures, with liquid-filled pipette tips as fluid columns at the inlets, to introduce low speed flows to the flow focusing junction. To control the size of the droplets, we systematically vary the interfacial tension and viscosity of the ATPS fluids and adjust the fluid column height at the fluid inlets. The size of the droplets scales with a power law of the ratio of viscous stresses in the two ATPS phases. Overall, we find a drop size coefficient of variation (CV; i.e., polydispersity) of about 10%. We also find that when drops form very close to the flow focusing junction, the drops have a CV of less than 1%. Our droplet generation method is easily scalable: we demonstrate a parallel system that generates droplets simultaneously and improves the droplet production rate by up to one order of magnitude. Finally, we show the potential application of our system for encapsulating cells in water-in-water emulsions by encapsulating microparticles and cells. To the best of our knowledge, our microfluidic technique is the first that forms low interfacial tension ATPS droplets without applying external perturbations. We anticipate that this simple approach will find utility in drug and cell delivery applications because of the all-biocompatible nature of the water-in-water ATPS environment.

  4. An Efficient Scalable Work-Stealing Runtime for Macro Data Flow Processing Using S-Net

    NARCIS (Netherlands)

    Gijsbers, B.; Grelck, C.

    2014-01-01

    S-Net is a declarative coordination language and component technology aimed at radically facilitating software engineering for modern parallel compute systems by near-complete separation of concerns between application (component) engineering and concurrency orchestration. S-Net builds on the

  5. Responses of prawn to water flow rates

    Energy Technology Data Exchange (ETDEWEB)

    Vascotto, G.L.; Nilas, P.U.

    1987-05-28

    An aquarium study to determine the responses of postlarval macrobrachium rosenbergii to varying water changes was carried out. Six week old postlarvae were raised in glass aquaria receiving 0, 1.15, 7.2 and 14.4 water changes per day over a 12 week period. The treatments had significant influences on survival, biomass, and average size of the animals. Maximum survival and highest biomass were found in the 1.15 water turnover treatment; however, this treatment also produced the smallest average size animals. Early high mortalities were attributed to poor growing conditions in the high and low flow treatments, while later mortality appeared to be biomass dependent.

  6. Net Zero Fort Carson: Integrating Energy, Water, and Waste Strategies to Lower the Environmental Impact of a Military Base

    Science.gov (United States)

    Military bases resemble small cities and face similar sustainability challenges. As pilot studies in the U.S. Army Net Zero program, 17 locations are moving to 100% renewable energy, zero depletion of water resources, and/or zero waste to landfill by 2020. Some bases target net z...

  7. Capturing the flow beneath water waves.

    Science.gov (United States)

    Nachbin, A; Ribeiro-Junior, R

    2018-01-28

    Recently, the authors presented two numerical studies for capturing the flow structure beneath water waves (Nachbin and Ribeiro-Junior 2014 Disc. Cont. Dyn. Syst. A 34 , 3135-3153 (doi:10.3934/dcds.2014.34.3135); Ribeiro-Junior et al. 2017 J. Fluid Mech. 812 , 792-814 (doi:10.1017/jfm.2016.820)). Closed orbits for irrotational waves with an opposing current and stagnation points for rotational waves were some of the issues addressed. This paper summarizes the numerical strategies adopted for capturing the flow beneath irrotational and rotational water waves. It also presents new preliminary results for particle trajectories, due to irrotational waves, in the presence of a bottom topography.This article is part of the theme issue 'Nonlinear water waves'. © 2017 The Author(s).

  8. Air-water flow in subsurface systems

    Science.gov (United States)

    Hansen, A.; Mishra, P.

    2013-12-01

    Groundwater traces its roots to tackle challenges of safe and reliable drinking water and food production. When the groundwater level rises, air pressure in the unsaturated Vadose zone increases, forcing air to escape from the ground surface. Abnormally high and low subsurface air pressure can be generated when the groundwater system, rainfall, and sea level fluctuation are favorably combined [Jiao and Li, 2004]. Through this process, contamination in the form of volatile gases may diffuse from the ground surface into residential areas, or possibly move into groundwater from industrial waste sites. It is therefore crucial to understand the combined effects of air-water flow in groundwater system. Here we investigate theoretically and experimentally the effects of air and water flow in groundwater system.

  9. Case study on ground water flow (8)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-01

    The report comprises research activities made in fiscal year 1997 under the contract of Japan Nuclear Fuel Cycle Development Center and the main items are: (1) Evaluation of water permeability through discontinuous hard bedrock in deep strata in relevant with underground disposal of radioactive wastes, (2) Three dimensional analysis of permeated water in bedrock, including flow analysis in T ono district using neuro-network and modification of Evaporation Logging System, (3) Development of hydraulic tests and necessary equipment applicable to measurements of complex dielectric constants of contaminated soils using FUDR-V method, this giving information on soil component materials, (4) Investigation methods and modeling of hydraulics in deep strata, (5) Geological study of ground water using environmental isotopes such as {sup 14}C, {sup 36}Cl and {sup 4}He, particularly measurement of ages of ground water using an accelerator-mass spectrometer, and (6) Re-submerging phenomena affecting the long-term geological stability. (S. Ohno)

  10. Quantitative imaging of water flow in soil and roots using neutron radiography and deuterated water

    Energy Technology Data Exchange (ETDEWEB)

    Zarebanadkouki, Mohsen

    2013-05-08

    Where and how fast do roots take up water? Despite its importance in plant and soil sciences, there is limited experimental information on the location of water uptake along the roots of transpiring plants growing in soil. The answer to this question requires direct and in-situ measurement of the local flow of water into the roots. The aim of this study was to develop and apply a new method to quantify the local fluxes of water into different segments of the roots of intact plants. To this end, neutron radiography was used to trace the transport of deuterated water (D{sub 2}O) into the roots of lupines. Lupines were grown in aluminum containers filled with sandy soil. The soil was partitioned into different compartments using 1 cm-thick layers of coarse sand as capillary barriers. These barriers limited the diffusion of D{sub 2}O within the soil compartments. D{sub 2}O was locally injected into the selected soil compartments during the day (transpiring plants) and night (non-transpiring plants). Transport of D{sub 2}O into roots was then monitored by neutron radiography with spatial resolution of 100 μm and time intervals of 10 seconds. Neutron radiographs showed that: i) transport of D{sub 2}O into roots was faster during the day than during the night; 2) D{sub 2}O quickly moved along the roots towards the shoots during the day, while at night this axial transport was negligible. The differences between day and night measurements were explained by convective transport of D{sub 2}O into the roots. To quantify the net flow of water into roots, a simple convection-diffusion model was developed, where the increase rate of D{sub 2}O concentration in roots depended on the convective transport (net root water uptake) and the diffusion of D{sub 2}O into roots. The results showed that water uptake was not uniform along the roots. Water uptake was higher in the upper soil layers than in the deeper ones. Along an individual roots, the water uptake rate was higher in the

  11. APROACHING THE ECONOMIC DIMENSION OF SUSTAINABLE DEVELOPMENT FROM A FINANCIAL PERSPECTIVE: A CASE STUDY REGARDING CASH - FLOW ANALYSIS AND THE RELATIONSIPS BETWEEN CASH - FLOW AND NET INCOME

    Directory of Open Access Journals (Sweden)

    Diana Elena Vasiu

    2014-10-01

    Full Text Available Europe 2020, a strategy for smart, sustainable and inclusive growth stresses the necessity of smart, sustainable and inclusive growth. The objectives of a sustainable economic development include sustaining economic growth, maximizing private profits and expanding markets. Considering this, economic development must based on facts, not on papers. Therefore, considering the economic dimension of sustainable development, it is important to establish if Romanian companies listed and traded on Bucharest Stock Exchange are able to obtain profit while cash is withdrawn. Even if reported in the income statement, net profit is not simultaneously charged due to accrual accounting that makes the balance sheet provide a static picture of the financial position, while the cash flow statement provides a dynamic picture of it. Therefore, the financial performance analysis based on classical indicators of performance must be accompanied by the analysis of treasury, namely of the cash flow, which provides a comprehensive assessment possibility of the financial performance, flexibility and adaptability of the economic entity, in the context of a highly competitive and often unstable environment. A positive net flows is a confirmation of the economic success of the company representing the concrete expression of the net profit and other pecuniary accumulations, interpreted as the real self-financing investment capacity, which would lead to the real asset growth and thus to the increase of the owners' wealth.

  12. [Endoscopic sinus surgery in flowing water].

    Science.gov (United States)

    Noda, K; Doi, K; Noiri, T; Koizuka, I; Kubo, T

    2000-05-01

    A balloon has been developed that completely fills the choana, preventing water from leaking into the pharynx even when the water is entering into the nasal cavity at a rate of 1000 ml per minute. The balloon enables endoscopic sinus surgery (ESS) to be safely performed in "flowing water". This surgical technique is similar to that used in transurethral resections of the prostate because the tip of the endoscope is kept clean, and blood, debris and resected tissues are continuously removed by the water flow. In addition, the water pressure helps to suppress bleeding. This technique enables ESS to be performed with greater ease and efficiency. We have performed ESS in flowing water on 38 patients with chronic sinusitis under local anaesthesia. No complications, such as water leakage into the pharynx, were encountered, and only a few patients felt discomfort from the insertion of the balloon. Even if the balloon had burst, an emergency could have been easily prevented by withdrawing the endoscope from the nasal cavity and stopping the flow of water. Ultrasonography (USG) was used to examine the water-filled nasal cavity during surgery (SSD-2000 and Micro Tip Radial (ASU-101); Aloka, Ltd., Japan). Using USG, the middle turbinate, the inferior turbinate and the nasal septum could be visualized in a single coronal image. When the sensor was in the posterior ethmoid sinus, the orbit and its optic nerve could also be visualized. Since this surgery is performed under local anesthesia, eye movements can rapidly alter the position of the optic nerve. Thus, visualization of the optic nerve's exact position is extremely important. Unfortunately, USG is not very useful for localizing structures and guiding the surgeon to distant tumors or cysts located behind thick bones, since ultrasound can not penetrate hard masses or bones. In this situation, navigation systems are more reliable than USG. Nevertheless, USG is often useful for depicting surgical sites, especially during a

  13. Quantifying the net benefit impacts of the Troy Waste Water Treatment Plant on Steelhead Habitat in the West Fork Little Bear Creek drainage

    Science.gov (United States)

    Sanchez-Murillo, R.; Brooks, E. S.; Boll, J.

    2010-12-01

    Discharge of waste water treatment plants (WWTPs) typically is viewed to result in water quality impairment. However, WWTPs can also be a source of nutrients to enhance the salmonid food web as well as an efficient way to maintain acceptable water temperature regimes and flow conditions during summer. We observed this paradox in West Fork Little Bear Creek (WFLB) in the City of Troy, Idaho. Despite the nutrient load, the WFLB had the highest Steelhead trout density in the watershed, with a mean density of 13.2 fish/100 m2. The objective of this project was to utilize a water quality model, QUAL2kw, and an ecology assessment to examine how the nutrient load from the WWTP affects: a) habitat conditions for steelhead juveniles, and b) physic-chemical parameters. Four monitoring stations were installed from May through November in 2009 and 2010. An undisturbed creek was used as a control site in 2010. Dissolved oxygen (DO), electrical conductivity, temperature, and discharge were measured continuously at each monitoring station. Weekly samples were collected at each monitoring station and analyzed for nitrate, nitrite, ammonia, total Kjeldahl nitrogen, total phosphorous, and orthophosphates. In 2010, Chlorophyll a was analyzed weekly, while bottom algae biomass was determined monthly. Results show that during summer months, the WWTP provides the majority of the flow (0.1 cfs) in the creek. Water samples and DO measurements taken 200 m downstream of the plant during late summer months indicate that nitrification process leads to low DO level well below the state standard of 6 mg/L for cold water biota. However dissolved oxygen levels recover within 1 km downstream. Discharge data suggest that without the flow from the treatment most of the creek would dry during late summer months. Abundance of macroinverbrates, high primary productivity, and sustained flow during summer suggests that the effluent from the WWTP is a net benefit to the Steelhead habitat in the basin

  14. A model of airport security work flow based on petri net

    Science.gov (United States)

    Dong, Xinming

    2017-09-01

    Extremely long lines at airports in the United States have been sharply criticized. In order to find out the bottleneck in the existing security system and put forward reasonable improvement plans and proposal, the Petri net model and the Markov Chain are introduced in this paper. This paper uses data collected by transportation Security Agency (TSA), assuming the data can represent the average level of all airports in the Unites States, to analysis the performance of security check system. By calculating the busy probabilities and the utilization probabilities, the bottleneck is found. Moreover, recommendation is given based on the parameters’ modification in Petri net model.

  15. Climatic and oceanic forcing of new, net, and diatom production in the North Water

    Science.gov (United States)

    Tremblay, Jean-Eric; Gratton, Yves; Fauchot, Juliette; Price, Neil M.

    New, net, and diatom production in the North Water were estimated during May to July 1998 from in vitro measurements of nitrate uptake and mesoscale temporal changes in the inventories of nitrate, silicate, oxygen, and inorganic carbon (DIC). Sampling stations were divided into two domains according to the position of the dominant water types: the silicate-rich Arctic water (SRAW) and Baffin Bay Water (BBW). BBW dominated in the southeast and was associated with relatively shallow upper mixed layers (UMLs) and weak horizontal advection. A phytoplankton bloom started in late April in BBW and grew slowly over 7 weeks, during which time the build-up of particulate organic nitrogen and carbon accounted for ca. 80% of the nitrate and DIC deficit, respectively. Over half of the new production (1.37 g C m -2 d -1) during this period was attributed to wind-driven replenishment of nitrate in the euphotic zone. The bloom culminated when seasonally declining winds and rising temperatures severed the UML from the deep nutrient reservoir. The same change in weather induced ice melt, stratification, and bloom development in northern SRAW, which had previously been characterized by deep UMLs. Collectively, the results imply that the timing and magnitude of blooms in the North Water are controlled by a succession of oceanic and climatic forcings. New C production in the North Water during April to July (1.11 g C m -2 d -1) was an order of magnitude higher than in adjacent waters and up to 8 times higher than in the Northeast Water polynya. As much as 80% of this production was mediated by diatoms >5 μm, suggesting potentially high and efficient C transfer to the herbivorous food web and deep waters.

  16. 49 CFR 229.111 - Water-flow indicator.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Water-flow indicator. 229.111 Section 229.111....111 Water-flow indicator. (a) Steam generators shall be equipped with an illuminated visual return water-flow indicator. (b) Steam generators shall be equipped with an operable test valve or other means...

  17. Effects of salinity variations on pore water flow in salt marshes

    Science.gov (United States)

    Shen, Chengji; Jin, Guangqiu; Xin, Pei; Kong, Jun; Li, Ling

    2015-06-01

    Spatial and temporal salinity variations in surface water and pore water commonly exist in salt marshes under the combined influence of tidal inundation, precipitation, evapotranspiration, and inland freshwater input. Laboratory experiments and numerical simulations were conducted to investigate how density gradients associated with salinity variations affect pore water flow in the salt marsh system. The results showed that upward salinity (density) gradients could lead to flow instability and the formation of salt fingers. These fingers, varying in size with the distance from the creek, modified significantly the pore water flow field, especially in the marsh interior. While the flow instability enhanced local salt transport and mixing considerably, the net effect was small, causing only a slight increase in the overall mass exchange across the marsh surface. In contrast, downward salinity gradients exerted less influence on the pore water flow in the marsh soil and slightly weakened the surface water and groundwater exchange across the marsh surface. Numerical simulations revealed similar density effects on pore water flow at the field scale under realistic conditions. These findings have important implications for studies of marsh soil conditions concerning plant growth as well as nutrient exchange between the marsh and coastal marine system.

  18. Model estimates of net primary productivity, evaportranspiration, and water use efficiency in the terrestrial ecosystems of the southern United States

    Science.gov (United States)

    Hanqin Tian; Guangsheng Chen; Mingliang Liu; Chi Zhang; Ge Sun; Chaoqun Lu; Xiaofeng Xu; Wei Ren; Shufen Pan; Arthur. Chappelka

    2010-01-01

    The effects of global change on ecosystem productivity and water resources in the southern United States (SUS), a traditionally ‘water-rich’ region and the ‘timber basket’ of the country, are not well quantified. We carried out several simulation experiments to quantify ecosystem net primary productivity (NPP), evapotranspiration (ET)...

  19. Tracer injection techniques in flowing surface water

    Science.gov (United States)

    Wörman, A.

    2009-04-01

    Residence time distributions for flowing water and reactive matter are commonly used integrated properties of the transport process for determining technical issues of water resource management and in eco-hydrological science. Two general issues for tracer techniques are that the concentration-vs-time relation following a tracer injection (the breakthrough curve) gives unique transport information in different parts of the curve and separation of hydromechanical and reactive mechanisms often require simultaneous tracer injections. This presentation discusses evaluation methods for simultaneous tracer injections based on examples of tracer experiments in small rivers, streams and wetlands. Tritiated water is used as a practically inert substance to reflect the actual hydrodynamics, but other involved tracers are Cr(III)-51, P-32 and N-15. Hydromechanical, in-stream dispersion is reflected as a symmetrical spreading of the spatial concentration distribution. This requires that the transport distance over water depth is larger than about five times the flow Peclet number. Transversal retention of both inert and reactive solutes is reflected in terms of the tail of the breakthrough curve. Especially, reactive solutes can have a substantial magnification of the tailing behaviour depending on reaction rates or partitioning coefficients. To accurately discriminate between the effects of reactions and hydromechanical mixing its is relevant to use simultaneous injections of inert and reactive tracers with a sequential or integrated evaluation procedure. As an example, the slope of the P-32 tailing is consistently smaller than that of a simultaneous tritium injection in Ekeby wetland, Eskilstuna. The same applies to N-15 injected in the same experiment, but nitrogen is affected also by a systematic loss due to denitrification. Uptake in stream-bed sediments can be caused by a pumping effect arising when a variable pressure field is created on the stream bottom due to bed

  20. Real-time DDoS attack detection for Cisco IOS using NetFlow

    NARCIS (Netherlands)

    van der Steeg, Daniël; Hofstede, R.J.; Sperotto, Anna; Pras, Aiko

    Flow-based DDoS attack detection is typically performed by analysis applications that are installed on or close to a flow collector. Although this approach allows for easy deployment, it makes detection far from real-time and susceptible to DDoS attacks for the following reasons. First, the fact

  1. Managing Water Sustainability: Virtual Water Flows and Economic Water Productivity Assessment of the Wine Trade between Italy and the Balkans

    Directory of Open Access Journals (Sweden)

    Pier Paolo Miglietta

    2018-02-01

    Full Text Available The management of natural resources in economic activities has become a fundamental issue when considering the perspective of sustainable development. It is necessary to rethink every process in order to reach efficiency from different points of view, not only environmentally but also economically. Water scarcity is growing because of economic and population growth, climate change, and the increasing water demand. Currently, agri-food represents the most water consumptive sector, and the increasing importance of international trade in this industry puts freshwater issues in a global context that should be analyzed and regulated by sustainable policies. This analysis is focused on virtual water flows and economic water productivity related to the wine trade, and aims to evaluate water loss/savings achieved through bilateral trade relations. The choice fell on Italy, the first wine producer in the world, and the Balkan countries. The latter are new markets for wine production/consumption, in which Italian wines are strongly positioned for different reasons. The results show that, from a national point of view and considering wine trade, Italy exports water in virtual form to the Balkan countries, more than it imports, so that in effect it partially uses its own water resources for the wine supply of the Balkans. The latter, on the other hand, being a net importer of wine, partially depends on Italian water resources and exerts less pressure on their own water basins in the supporting wine supply. We also observed that the wine trade between Italy and the Balkans implies global water savings.

  2. Probabilistic and Other Neural Nets in Multi-Hole Probe Calibration and Flow Angularity Pattern Recognition

    Science.gov (United States)

    Baskaran, Subbiah; Ramachandran, Narayanan; Noever, David

    1998-01-01

    The use of probabilistic (PNN) and multilayer feed forward (MLFNN) neural networks are investigated for calibration of multi-hole pressure probes and the prediction of associated flow angularity patterns in test flow fields. Both types of networks are studied in detail for their calibration and prediction characteristics. The current formalism can be applied to any multi-hole probe, however the test results for the most commonly used five-hole Cone and Prism probe types alone are reported in this article.

  3. Multiscale simulation of water flow past a C540 fullerene

    DEFF Research Database (Denmark)

    Walther, Jens Honore; Praprotnik, Matej; Kotsalis, Evangelos M.

    2012-01-01

    We present a novel, three-dimensional, multiscale algorithm for simulations of water flow past a fullerene. We employ the Schwarz alternating overlapping domain method to couple molecular dynamics (MD) of liquid water around the C540 buckyball with a Lattice–Boltzmann (LB) description...... algorithms. We use this method to determine the slip length and hydrodynamic radius for water flow past a buckyball....

  4. Virtual water flows in the international trade of agricultural products of China.

    Science.gov (United States)

    Zhang, Yu; Zhang, Jinhe; Tang, Guorong; Chen, Min; Wang, Lachun

    2016-07-01

    With the rapid development of the economy and population, water scarcity and poor water quality caused by water pollution have become increasingly severe in China. Virtual water trade is a useful tool to alleviate water shortage. This paper focuses on a comprehensive study of China's international virtual water flows from agricultural products trade and completes a diachronic analysis from 2001 to 2013. The results show that China was in trade surplus in relation to the virtual water trade of agricultural products. The exported virtual water amounted to 29.94billionm(3)/yr. while 155.55billionm(3)/yr. was embedded in imported products. The trend that China exported virtual water per year was on the decline while the imported was on a rising trend. Virtual water trade of China was highly concentrated. Not all of the exported products had comparative advantages in virtual water content. Imported products were excessively concentrated on water intensive agricultural products such as soya beans, cotton, and palm oil. The exported virtual water mainly flowed to the Republic of Korea, Hong Kong of China and Japan, while the imported mainly flowed from the United States of America, Brazil and Argentina. From the ethical point of view, the trade partners were classified into four types in terms of "net import" and "water abundance": mutual benefit countries, such as Australia and Canada; unilateral benefit countries, such as Mongolia and Norway; supported countries, such as Egypt and Singapore; and double pressure countries, such as India and Pakistan. Virtual water strategy refers to water resources, agricultural products and human beings. The findings are beneficial for innovating water resources management system, adjusting trade structure, ensuring food security in China, and promoting the construction of national ecological security system. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. A generalized flow path model for water distribution optimization

    Science.gov (United States)

    Hsu, N.; Cheng, W.; Yeh, W. W.

    2008-12-01

    A generalized flow path model is developed for optimizing a water distribution system. The model simultaneously describes a water distribution system in two parts: (1) the water delivery relationships between suppliers and receivers and (2) the physical water delivery system. In the first part, the model considers waters from different suppliers as multiple commodities. This helps the model to clearly describe water deliveries by identifying the relationships between suppliers and receivers. The second part characterizes a physical water distribution network by all possible flow paths. The advantages of the proposed model are that: (1) it is a generalized methodology to optimize water distribution, delivery scheduling, water trade, water transfer, and water exchange under existing reservoir operation rules, contracts, and agreements; (2) it can consider water as multiple commodities if needed; and (3) no simplifications are made for either the physical system or the delivery relationships. The model can be used as a tool for decision making for scheduling optimization. The model optimizes not only the suppliers to each receiver but also their associated flow paths for supplying water. This characteristic leads to the optimum solution that contains the optimal scheduling results and detailed information of water distribution in the physical system. That is, the water right owner, water quantity and its associated flow path of each delivery action are represented explicitly in the results rather than merely an optimized total flow quantity in each arc of a distribution network. The proposed model is first verified by a hypothetical water distribution system. Then, the model is applied to the water distribution system of the Tou-Qian River Basin in northern Taiwan. The results show that the flow path model has the ability to optimize the quantity of each water delivery, the associated flow paths of the delivery, and the strategies of water transfer while considering

  6. Estimation of net ecosystem metabolism of seagrass meadows in the coastal waters of the East Sea and Black Sea using the noninvasive eddy covariance technique

    Science.gov (United States)

    Lee, Jae Seong; Kang, Dong-Jin; Hineva, Elitsa; Slabakova, Violeta; Todorova, Valentina; Park, Jiyoung; Cho, Jin-Hyung

    2017-06-01

    We measured the community-scale metabolism of seagrass meadows in Bulgaria (Byala [BY]) and Korea (Hoopo Bay [HP]) to understand their ecosystem function in coastal waters. A noninvasive in situ eddy covariance technique was applied to estimate net O2 flux in the seagrass meadows. From the high-quality and high-resolution time series O2 data acquired over > 24 h, the O2 flux driven by turbulence was extracted at 15-min intervals. The spectrum analysis of vertical flow velocity and O2 concentration clearly showed well-developed turbulence characteristics in the inertial subrange region. The hourly averaged net O2 fluxes per day ranged from -474 to 326 mmol O2 m-2 d-1 (-19 ± 41 mmol O2 m-2 d-1) at BY and from -74 to 482 mmol O2 m-2 d-1 (31 ± 17 mmol O2 m-2 d-1) at HP. The net O2 production rapidly responded to photosynthetically available radiation (PAR) and showed a good relationship between production and irradiance (P-I curve). The hysteresis pattern of P-I relationships during daytime also suggested increasing heterotrophic respiration in the afternoon. With the flow velocity between 3.30 and 6.70 cm s-1, the community metabolism during daytime and nighttime was significantly increased by 20 times and 5 times, respectively. The local hydrodynamic characteristics may be vital to determining the efficiency of community photosynthesis. The net ecosystem metabolism at BY was estimated to be -17 mmol O2 m-2 d-1, which was assessed as heterotrophy. However, that at HP was 36 mmol O2 m-2 d-1, which suggested an autotrophic state.

  7. Evaluating the Life Cycle Environmental Benefits and Trade-Offs of Water Reuse Systems for Net-Zero Buildings.

    Science.gov (United States)

    Hasik, Vaclav; Anderson, Naomi E; Collinge, William O; Thiel, Cassandra L; Khanna, Vikas; Wirick, Jason; Piacentini, Richard; Landis, Amy E; Bilec, Melissa M

    2017-02-07

    Aging water infrastructure and increased water scarcity have resulted in higher interest in water reuse and decentralization. Rating systems for high-performance buildings implicitly promote the use of building-scale, decentralized water supply and treatment technologies. It is important to recognize the potential benefits and trade-offs of decentralized and centralized water systems in the context of high-performance buildings. For this reason and to fill a gap in the current literature, we completed a life cycle assessment (LCA) of the decentralized water system of a high-performance, net-zero energy, net-zero water building (NZB) that received multiple green building certifications and compared the results with two modeled buildings (conventional and water efficient) using centralized water systems. We investigated the NZB's impacts over varying lifetimes, conducted a break-even analysis, and included Monte Carlo uncertainty analysis. The results show that, although the NZB performs better in most categories than the conventional building, the water efficient building generally outperforms the NZB. The lifetime of the NZB, septic tank aeration, and use of solar energy have been found to be important factors in the NZB's impacts. While these findings are specific to the case study building, location, and treatment technologies, the framework for comparison of water and wastewater impacts of various buildings can be applied during building design to aid decision making. As we design and operate high-performance buildings, the potential trade-offs of advanced decentralized water treatment systems should be considered.

  8. Towards real-time intrusion detection for NetFlow and IPFIX

    NARCIS (Netherlands)

    Hofstede, R.J.; Bartos, Vaclav; Sperotto, Anna; Pras, Aiko

    2013-01-01

    DDoS attacks bring serious economic and technical damage to networks and enterprises. Timely detection and mitigation are therefore of great importance. However, when flow monitoring systems are used for intrusion detection, as it is often the case in campus, enterprise and backbone networks, timely

  9. NetFCM: A Semi-Automated Web-Based Method for Flow Cytometry Data Analysis

    DEFF Research Database (Denmark)

    Frederiksen, Juliet Wairimu; Buggert, Marcus; Karlsson, Annika C.

    2014-01-01

    Multi-parametric flow cytometry (FCM) represents an invaluable instrument to conduct single cell analysis and has significantly increased our understanding of the immune system. However, due to new techniques allowing us to measure an increased number of phenotypes within the immune system, FCM...... for Advancement of Cytometry...

  10. Effect of cholera toxin on glucose absorption and net movements of water and electrolytes in the intestinal loop of sheep.

    Science.gov (United States)

    Hyun, H S; Onaga, T; Mineo, H; Kim, J T; Kato, S

    1996-12-01

    This study was designed to evaluate the effect of cholera toxin on glucose absorption and net movement of water and electrolytes in the jejunal loop of sheep. Intraluminal perfusion was performed at the rate of 1 ml/min with isotonic 10 mM glucose solution. Osmolality was adjusted by adding NaCl, and the outflow solution was collected every 10 min. After a 30 min control period, cholera toxin was applied intraluminally for 30 min at doses of 30, 60, and 120 micrograms/loop. In the control period, water, sodium and chloride were absorbed, while potassium and bicarbonate were secreted. Cholera toxin reversed the net absorption of water, sodium and chloride to net secretions, and this secretory response to cholera toxin was dose-dependent. Bicarbonate secretion was stimulated dose-dependently by cholera toxin. Potassium secretion was also increased at all doses, though this response was not dose-dependent. The net glucose absorption was decreased dose-dependently by cholera toxin. In conclusion, these results indicate that cholera toxin stimulates water and electrolyte secretion, and inhibits glucose absorption in the jejunal loop of sheep.

  11. The importance of base flow in sustaining surface water flow in the Upper Colorado River Basin

    National Research Council Canada - National Science Library

    Miller, Matthew P; Buto, Susan G; Susong, David D; Rumsey, Christine A

    2016-01-01

    ...) water quality model to assess the spatial distribution of base flow, the fraction of streamflow supported by base flow, and estimates of and potential processes contributing to the amount of base...

  12. Relating Water and Air Flow Characteristics in Coarse Granular Materials

    DEFF Research Database (Denmark)

    Andreasen, Rune Røjgaard; Canga, Eriona; Kjærgaard, Charlotte

    2013-01-01

    from air flow data. The objective of this study was, therefore, to investigate if this approach is valid 8 also for coarse granular biofilter media which usually consists of much larger particles than soils. In 9 this paper the connection between the pressure drop – velocity relationships for air...... and water flow was 10 investigated using a common biofilter medium, Leca® consisting of rounded porous particles of 2 – 16 11 mm diameter. Pressure drop – velocity relations for water flow were measured for 14 different Leca ® 12 particle size fractions and compared to measurements of the pressure drop...... – velocity relations for air 13 flow in 36 different Leca® particle size fractions (including the 14 used for water flow). The 14 measurements showed that it is indeed possible to predict the pressure drop – velocity relationship for 15 water flow from the corresponding relationship for air flow not only...

  13. Development of a numerical model for fluid-structure interaction analysis of flow through and around an aquaculture net cage

    DEFF Research Database (Denmark)

    Chen, Hao; Christensen, Erik Damgaard

    2017-01-01

    In the present work, we developed a numerical model for fluid-structure interaction analysis of flow through and around an aquaculture net cage. The numerical model is based on the coupling between the porous media model and the lumped mass structural model. A novel interface was implemented...... was approximated by a set of dynamic porous zones, where the grid cells were updated at every iteration based on the transferred nodal positions from the structural model. A time stepping procedure was introduced, so the solver is applicable in both steady and unsteady conditions. In order to reduce...... the computational effort, sub-cycling was applied for the structural solver within each time step, based on the quasi-steady state assumption. The numerical model was validated against experiments in both steady and unsteady conditions. In general, the agreement is satisfactory....

  14. Pumpage for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set represents ground-water discharged from the Death Valley regional ground-water flow system (DVRFS) through pumped wells. Pumping from wells in...

  15. Secondary flows in the cooling channels of the high-performance light-water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Laurien, E.; Wintterle, Th. [Stuttgart Univ., Institute for Nuclear Technolgy and Energy Systems (IKE) (Germany)

    2007-07-01

    The new design of a High-Performance Light-Water Reactor (HPLWR) involves a three-pass core with an evaporator region, where the compressed water is heated above the pseudo-critical temperature, and two superheater regions. Due to the strong dependency of the supercritical water density on the temperature significant mass transfer between neighboring cooling channels is expected if the temperature is unevenly distributed across the fuel element. An inter-channel flow is then superimposed to the secondary flow vortices induced by the non-isotropy of turbulence. In order to gain insight into the resulting flow patterns as well as into temperature and density distributions within the various subchannels of the fuel element CFD (Computational Fluid Dynamics) calculations for the 1/8 fuel element are performed. For simplicity adiabatic boundary conditions at the moderator box and the fuel element box are assumed. Our investigation confirms earlier results obtained by subchannel analysis that the axial mass flux is significantly reduced in the corner subchannel of this fuel element resulting in a net mass flux towards the neighboring subchannels. Our results provide a first estimation of the magnitude of the secondary flows in the pseudo-critical region of a supercritical light-water reactor. Furthermore, it is demonstrated that CFD is an efficient tool for investigations of flow patterns within nuclear reactor fuel elements. (authors)

  16. Besnoitia besnoiti infections activate primary bovine endothelial cells and promote PMN adhesion and NET formation under physiological flow condition.

    Science.gov (United States)

    Maksimov, P; Hermosilla, C; Kleinertz, S; Hirzmann, J; Taubert, A

    2016-05-01

    Besnoitia besnoiti is an obligate intracellular and emerging coccidian parasite of cattle that mainly infects host endothelial cells during acute infection. We here analyzed early innate immune reactions of B. besnoiti-infected primary bovine umbilical vein endothelial cells (BUVEC). B. besnoiti infections significantly activated BUVEC since the gene transcripts of several adhesion molecules (P-selectin, intercellular adhesion molecule 1(ICAM-1)), chemokines (CXCL1, CXCL8, CCL5), and of COX-2 were significantly upregulated during in vitro infection. Overall, the highest upregulation of most transcripts was observed at 24 or 48 h post infection (p.i.). Enhanced adhesion molecule expression in infected host cells was confirmed by PMN adhesion assays being performed under physiological flow conditions revealing a significantly increased PMN adhesion on B. besnoiti-infected BUVEC layers at 24 h p.i. Furthermore, we were able to illustrate neutrophil extracellular traps (NETs) being released by PMN under physiological flow conditions after adhesion to B. besnoiti-infected BUVEC layers. The present study shows that B. besnoiti infections of primary BUVEC induce a cascade of pro-inflammatory reactions and triggers early innate immune responses.

  17. Self Calibrating Flow Estimation in Waste Water Pumping Stations

    DEFF Research Database (Denmark)

    Kallesøe, Carsten Skovmose; Knudsen, Torben

    2016-01-01

    Knowledge about where waste water is flowing in waste water networks is essential to optimize the operation of the network pumping stations. However, installation of flow sensors is expensive and requires regular maintenance. This paper proposes an alternative approach where the pumps and the waste...... water pit are used for estimating both the inflow and the pump flow of the pumping station. Due to the nature of waste water, the waste water pumps are heavily affected by wear and tear. To compensate for the wear of the pumps, the pump parameters, used for the flow estimation, are automatically...... calibrated. This calibration is done based on data batches stored at each pump cycle, hence makes the approach a self calibrating system. The approach is tested on a pumping station operating in a real waste water network....

  18. Imaging water velocity and volume fraction distributions in water continuous multiphase flows using inductive flow tomography and electrical resistance tomography

    Science.gov (United States)

    Meng, Yiqing; Lucas, Gary P.

    2017-05-01

    This paper presents the design and implementation of an inductive flow tomography (IFT) system, employing a multi-electrode electromagnetic flow meter (EMFM) and novel reconstruction techniques, for measuring the local water velocity distribution in water continuous single and multiphase flows. A series of experiments were carried out in vertical-upward and upward-inclined single phase water flows and ‘water continuous’ gas-water and oil-gas-water flows in which the velocity profiles ranged from axisymmetric (single phase and vertical-upward multiphase flows) to highly asymmetric (upward-inclined multiphase flows). Using potential difference measurements obtained from the electrode array of the EMFM, local axial velocity distributions of the continuous water phase were reconstructed using two different IFT reconstruction algorithms denoted RT#1, which assumes that the overall water velocity profile comprises the sum of a series of polynomial velocity components, and RT#2, which is similar to RT#1 but which assumes that the zero’th order velocity component may be replaced by an axisymmetric ‘power law’ velocity distribution. During each experiment, measurement of the local water volume fraction distribution was also made using the well-established technique of electrical resistance tomography (ERT). By integrating the product of the local axial water velocity and the local water volume fraction in the cross section an estimate of the water volumetric flow rate was made which was compared with a reference measurement of the water volumetric flow rate. In vertical upward flows RT#2 was found to give rise to water velocity profiles which are consistent with the previous literature although the profiles obtained in the multiphase flows had relatively higher central velocity peaks than was observed for the single phase profiles. This observation was almost certainly a result of the transfer of axial momentum from the less dense dispersed phases to the water

  19. The water value-flow concept

    NARCIS (Netherlands)

    Seyam, I.M.; Hoekstra, Arjen Ysbert; Savenije, H.H.G.

    2003-01-01

    The value of water is a key issue in managing water resources in an efficient, equitable and sustainable way. Efforts to assess the value of water are often not linked to the properties of the natural water system, which makes it difficult to analyse upstream–downstream dependency. In order to

  20. Assessment of imaging-in-flow system (FlowCAM) for systematic ballast water management

    NARCIS (Netherlands)

    Romero-Martínez, L.; van Slooten, C.; Nebot, E.; Acevedo-Merino, A.; Peperzak, L.

    2017-01-01

    Assessing the disinfection of ballast water and its compliance with international standards requires determiningthe size, viability, and concentration of planktonic organisms. The FlowCAM(FlowCytometer andMicroscope) isan Imaging FlowCytometry designed to obtain the particle concentration, images,

  1. Horizontal flow barriers for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the surface traces of regional features simulated as horizontal flow barriers in the Death Valley regional ground-water flow system...

  2. Globalisation of water resources: International virtual water flows in relation to international crop trade

    NARCIS (Netherlands)

    Hoekstra, Arjen Ysbert; Hung, P.Q.

    2005-01-01

    The water that is used in the production process of a commodity is called the ‘virtual water’ contained in the commodity. International trade of commodities brings along international flows of virtual water. The objective of this paper is to quantify the volumes of virtual water flows between

  3. Viscosity of Water Interfaces with Hydrophobic Nanopores: Application to Water Flow in Carbon Nanotubes.

    Science.gov (United States)

    Shaat, M

    2017-11-07

    The nanoconfinement of water results in changes in water properties and nontraditional water flow behaviors. The determination of the interfacial interactions between water and hydrophobic surfaces helps in understanding many of the nontraditional behaviors of nanoconfined water. In this study, an approach for the identification of the viscosity of water interfaces with hydrophobic nanopores as a function of the nanopore diameter and water-solid (nanopore) interactions is proposed. In this approach, water in a hydrophobic nanopore is represented as a double-phase water with two distinct viscosities: water interface and water core. First, the slip velocity to pressure gradient ratio of water flow in hydrophobic nanopores is obtained via molecular dynamics (MD) simulations. Then the water interface viscosity is determined via a pressure gradient-based bilayer water flow model. Moreover, the core viscosity and the effective viscosity of water flow in hydrophobic nanopores are derived as functions of the nanopore diameter and water-solid interactions. This approach is utilized to report the interface viscosity, core viscosity, and effective viscosity of water flow in carbon nanotubes (CNTs) as functions of the CNT diameter. Moreover, using the proposed approach, the transition from MD to continuum mechanics is revealed where the bulk water properties are recovered for large CNTs.

  4. Net heterotrophy in Faroe Islands clear-water lakes: causes and consequences for bacterioplankton and phytoplankton

    DEFF Research Database (Denmark)

    Pålsson, C.; Kritzberg, E. S.; Christoffersen, K.

    2005-01-01

    ) and measured the grazing pressure exerted by common mixotrophic species on bacteria. 2. High respiration to primary production (6.6-33.2) and supersaturation of CO2 (830-2140 µatm) implied that the lakes were net heterotrophic and that the pelagic heterotrophic plankton were subsidised by allochthonous organic...... conditions and hence low primary production in combination with an input of allochthonous C with a relatively high availability. 4. Mixotrophic phytoplankton (Cryptomonas spp., Dinobryon spp. and flagellates cf. Ochromonas spp.) constituted a large percentage of the plankton community (17-83%), possibly...... carbon. However, in spite of the apparent high level of net heterotrophy, primary production exceeded bacterial production and the food base for higher trophic levels appeared to be mainly autotrophic. 3. We suggest that the observed net heterotrophy in these lakes was a result of the oligotrophic...

  5. Agricultural virtual water flows within the United States

    Science.gov (United States)

    Dang, Qian; Lin, Xiaowen; Konar, Megan

    2015-02-01

    Trade plays an increasingly important role in the global food system, which is projected to be strained by population growth, economic development, and climate change. For this reason, there has been a surge of interest in the water resources embodied in international trade, referred to as "global virtual water trade." In this paper, we present a comprehensive assessment of virtual water flows within the United States (U.S.), a country with global importance as a major agricultural producer and trade power. This is the first study of domestic virtual water flows based upon intranational food transfer empirical data and it provides insight into how the properties of virtual water transfers vary across scales. We find that the volume of virtual water flows within the U.S. is equivalent to 51% of international flows, which is slightly higher than the U.S. food value and mass shares, due to the fact that water-intensive meat commodities comprise a much larger fraction of food transfers within the U.S.. The U.S. virtual water flow network is more social, homogeneous, and equitable than the global virtual water trade network, although it is still not perfectly equitable. Importantly, a core group of U.S. States is central to the network structure, indicating that both domestic and international trade may be vulnerable to disruptive climate or economic shocks in these U.S. States.

  6. Initial Survey Instructions for Spring Water Monitoring : Flow

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Initial survey instructions for the Spring Water Monitoring - Flow 1.02 survey at Fish Springs National Wildlife Refuge. This coop baseline monitoring survey has...

  7. Modelling flow dynamics in water distribution networks using ...

    African Journals Online (AJOL)

    DR OKE

    Keywords: Artificial neural network; Leakage detection technique; Water distribution; Leakages ... techniques, artificial neural networks (ANNs), genetic algorithms (GA), and probabilistic and evidential reasoning. ANNs are mimicry of ..... Implementation of an online artificial intelligence district meter area flow meter data.

  8. Bridge pressure flow scour for clear water conditions

    Science.gov (United States)

    2009-10-01

    The equilibrium scour at a bridge caused by pressure flow with critical approach velocity in clear-water simulation conditions was studied both analytically and experimentally. The flume experiments revealed that (1) the measured equilibrium scour pr...

  9. Governing urban water flows in China

    NARCIS (Netherlands)

    Zhong, L.

    2007-01-01

    China has been witnessing an unprecedented period of continuous high economic growth during the past three decades. But this has been paralleled by severe environmental challenges, of which water problems are of key importance. This thesis addresses the urban water challenges of contemporary China,

  10. Effect of twine diameter on fishing power of experimental gill nets used in Greenland waters

    DEFF Research Database (Denmark)

    Hovgård, Holger

    1996-01-01

    The relative fishing powers of experimental gill nets were estimated for shorthorn sculpin (Myoxocephalus scorpius), Greenland cod (Gadus ogac), and Atlantic cod (Gadus morhua). The results suggested that fishing power was negatively correlated to the ratio between twine diameter and mesh size...

  11. Flow properties of water-based drilling fluids

    OpenAIRE

    Kristensen, Aleksander

    2013-01-01

    The objective of this master thesis was to investigate the flow properties of water based drilling fluids, utilizing measurements in both the micro and macro scale. The research was performed on two realistic drilling fluids by the use of a viscometer, a rheometer and a realistic flow loop, where the latter represents the macro scale. The research outcome could possibly improve the understanding of flow behavior in wellbores, and remove uncertainties associated with annular friction. The two...

  12. Electrokinetic instability in microchannel ferrofluid/water co-flows

    OpenAIRE

    Le Song; Liandong Yu; Yilong Zhou; Asher Reginald Antao; Rama Aravind Prabhakaran; Xiangchun Xuan

    2017-01-01

    Electrokinetic instability refers to unstable electric field-driven disturbance to fluid flows, which can be harnessed to promote mixing for various electrokinetic microfluidic applications. This work presents a combined numerical and experimental study of electrokinetic ferrofluid/water co-flows in microchannels of various depths. Instability waves are observed at the ferrofluid and water interface when the applied DC electric field is beyond a threshold value. They are generated by the elec...

  13. 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. Both...

  14. Linking flow, water quality and potential effects on aquatic biota ...

    African Journals Online (AJOL)

    Linking the potential effects of altered water quality on aquatic biota, that may result from a change in the flow (discharge) regime, is an essential step in the maintenance of riverine ecological functioning. Determination of the environmental flow requirement of a river (as well as other activities, such as classifying the ...

  15. 33 CFR 2.34 - Waters subject to tidal influence; waters subject to the ebb and flow of the tide; mean high water.

    Science.gov (United States)

    2010-07-01

    ...; waters subject to the ebb and flow of the tide; mean high water. 2.34 Section 2.34 Navigation and....34 Waters subject to tidal influence; waters subject to the ebb and flow of the tide; mean high water. (a) Waters subject to tidal influence and waters subject to the ebb and flow of the tide are waters...

  16. Remote sensing as a tool for watershed-wide estimation of net solar radiation and water loss to the atmosphere

    Science.gov (United States)

    Khorram, S.; Thomas, R. W.

    1976-01-01

    Results are presented for a study intended to develop a general remote sensing-aided cost-effective procedure to estimate watershed-wide water loss to the atmosphere via evapotranspiration and to estimate net solar radiation over the watershed. Evapotranspiration estimation employs a basic two-stage two-phase sample of three information resolution levels. Net solar radiation is taken as one of the variables at each level of evapotranspiration modeling. The input information for models requiring spatial information will be provided by Landsat digital data, environmental satellite data, ground meteorological data, ground sample unit information, and topographic data. The outputs of the sampling-estimation/data bank system will be in-place maps of evapotranspiration on a data resolution element basis, watershed-wide evapotranspiration isopleths, and estimates of watershed and subbasin total evapotranspiration with associated statistical confidence bounds. The methodology developed is being tested primarily on the Spanish Creek Watershed Plumas County, California.

  17. Flow improvers for water injection based on surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Oskarsson, H.; Uneback, I.; Hellsten, M.

    2006-03-15

    In many cases it is desirable to increase the flow of injection water when an oil well deteriorates. It is very costly in offshore operation to lay down an additional water pipe to the injection site. Flow improvers for the injection water will thus be the most cost-effective way to increase the flow rate. During the last years water-soluble polymers have also been applied for this purpose. These drag-reducing polymers are however only slowly biodegraded which has been an incentive for the development of readily biodegradable surfactants as flow improvers for injection water. A combination of a zwitterionic and an anionic surfactant has been tested in a 5.5 inch, 700 m long flow loop containing sulphate brine with salinity similar to sea water. A drag reduction between 75 and 80% was achieved with 119 ppm in solution of the surfactant blend at an average velocity of 1.9 m/s and between 50 and 55% at 2.9 m/s. The surfactants in this formulation were also found to be readily biodegradable in sea water and low bio accumulating which means they have an improved environmental profile compared to the polymers used today. Due to the self-healing properties of the drag-reducing structures formed by surfactants, these may be added before the pump section - contrary to polymers which are permanently destroyed by high shear forces. (Author)

  18. Applicability of energy-positive net-zero water management in Alaska: technology status and case study.

    Science.gov (United States)

    Wu, Tingting; Englehardt, James D; Guo, Tianjiao; Gassie, Lucien; Dotson, Aaron

    2017-11-22

    Challenges of water and wastewater management in Alaska include the potential need for above-grade and freeze-protected piping, high unit energy costs and, in many rural areas, low population density and median annual income. However, recently developed net-zero water (NZW), i.e., nearly closed-loop, direct potable water reuse systems, can retain the thermal energy in municipal wastewater, producing warm treated potable water without the need for substantial water re-heating, heat pumping or transfer, or additional energy conversion. Consequently, these systems are projected to be capable of saving more energy than they use in water treatment and conveyance, in the temperate USA. In this paper, NZW technology is reviewed in terms of potential applicability in Alaska by performing a hypothetical case study for the city of Fairbanks, Alaska. Results of this paper study indicate that in municipalities of Alaska with local engineering and road access, the use of NZW systems may provide an energy-efficient water service option. In particular, case study modeling suggests hot water energy savings are equivalent to five times the energy used for treatment, much greater savings than in mid-latitudes, due largely to the substantially higher energy needed for heating water from a conventional treatment system and lack of need for freeze-protected piping. Further study of the applicability of NZW technology in cold regions, with expanded evaluation in terms of system-wide lifecycle cost, is recommended.

  19. An Experimental Study of Oil / Water Flow in Horizontal Pipes

    Energy Technology Data Exchange (ETDEWEB)

    Elseth, Geir

    2001-07-01

    The purpose of this thesis is to study the behaviour of the simultaneous flow of oil and water in horizontal pipes. In this connection, two test facilities are used. Both facilities have horizontal test sections with inner pipe diameters equal to 2 inches. The largest facility, called the model oil facility, has reservoirs of 1 m{sub 3} of each medium enabling flow rates as high as 30 m{sub 3}/h, which corresponds to mixture velocities as high as 3.35 m/s. The flow rates of oil and water can be varied individually producing different flow patterns according to variations in mixture velocity and input water cut. Two main classes of flows are seen, stratified and dispersed. In this facility, the main focus has been on stratified flows. Pressure drops and local phase fractions are measured for a large number of flow conditions. Among the instruments used are differential pressure transmitters and a traversing gamma densitometer, respectively. The flow patterns that appear are classified in flow pattern maps as functions of either mixture velocity and water cut or superficial velocities. From these experiments a smaller number of stratified flows are selected for studies of velocity and turbulence. A laser Doppler anemometer (LDA) is applied for these measurements in a transparent part of the test section. To be able to produce accurate measurements a partial refractive index matching procedure is used. The other facility, called the matched refractive index facility, has a 0.2 m{sub 3} reservoir enabling mainly dispersed flows. Mixture velocities range from 0.75 m/s to 3 m/s. The fluids in this facility are carefully selected to match the refractive index of the transparent part of the test section. A full refractive index matching procedure is carried out producing excellent optical conditions for velocity and turbulence studies by LDA. In addition, pressure drops and local phase fractions are measured. (author)

  20. Potential structural barriers to ground-water flow, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the surface traces of regional geologic structures designated as potential ground-water flow barriers in an approximately 45,000...

  1. Standardization of flow cytometry in myelodysplastic syndromes: report from the first European LeukemiaNet working conference on flow cytometry in myelodysplastic syndromes

    Science.gov (United States)

    van de Loosdrecht, Arjan A.; Alhan, Canan; Béné, Marie Christine; Della Porta, Matteo G.; Dräger, Angelika M.; Feuillard, Jean; Font, Patricia; Germing, Ulrich; Haase, Detlef; Homburg, Christa H.; Ireland, Robin; Jansen, Joop H.; Kern, Wolfgang; Malcovati, Luca; te Marvelde, Jeroen G.; Mufti, Ghulam J.; Ogata, Kiyoyuki; Orfao, Alberto; Ossenkoppele, Gert J.; Porwit, Anna; Preijers, Frank W.; Richards, Stephen J.; Schuurhuis, Gerrit Jan; Subirá, Dolores; Valent, Peter; van der Velden, Vincent H.J.; Vyas, Paresh; Westra, August H.; de Witte, Theo M.; Wells, Denise A.; Loken, Michael R.; Westers, Theresia M.

    2009-01-01

    The myelodysplastic syndromes are a group of clonal hematopoietic stem cell diseases characterized by cytopenia(s), dysplasia in one or more cell lineages and increased risk of evolution to acute myeloid leukemia (AML). Recent advances in immunophenotyping of hematopoietic progenitor and maturing cells in dysplastic bone marrow point to a useful role for multiparameter flow cytometry (FCM) in the diagnosis and prognostication of myelodysplastic syndromes. In March 2008, representatives from 18 European institutes participated in a European LeukemiaNet (ELN) workshop held in Amsterdam as a first step towards standardization of FCM in myelodysplastic syndromes. Consensus was reached regarding standard methods for cell sampling, handling and processing. The group also defined minimal combinations of antibodies to analyze aberrant immunophenotypes and thus dysplasia. Examples are altered numbers of CD34+ precursors, aberrant expression of markers on myeloblasts, maturing myeloid cells, monocytes or erythroid precursors and the expression of lineage infidelity markers. When applied in practice, aberrant FCM patterns correlate well with morphology, the subclassification of myelodysplastic syndromes, and prognostic scoring systems. However, the group also concluded that despite strong evidence for an impact of FCM in myelodysplastic syndromes, further (prospective) validation of markers and immunophenotypic patterns are required against control patient groups as well as further standardization in multi-center studies. Standardization of FCM in myelodysplastic syndromes may thus contribute to improved diagnosis and prognostication of myelodysplastic syndromes in the future. PMID:19546437

  2. Northern pike bycatch in an inland commercial hoop net fishery: effects of water temperature and net tending frequency on injury, physiology, and survival

    Energy Technology Data Exchange (ETDEWEB)

    Colotelo, Alison HA; Raby, Graham D.; Hasler, Caleb T.; Haxton, Tim; Smokorowski, Karen; Blouin-Demers, Gabriel; Cooke, Steven J.

    2013-01-01

    In lakes and rivers of eastern Ontario (Canada) commercial fishers use hoop nets to target a variety of fishes, but incidentally capture non-target (i.e., bycatch) gamefish species such as northern pike (Esox lucius). Little is known about the consequences of bycatch in inland commercial fisheries, making it difficult to identify regulatory options. Regulations that limit fishing during warmer periods and that require frequent net tending have been proposed as possible strategies to reduce bycatch mortality. Using northern pike as a model, we conducted experiments during two thermal periods (mid-April: 14.45 ± 0.32 °C, and late May: 17.17 ± 0.08 °C) where fish were retained in nets for 2 d and 6 d. A ‘0 d’ control group consisted of northern pike that were angled, immediately sampled and released. We evaluated injury, physiological status and mortality after the prescribed net retention period and for the surviving fish used radio telemetry with manual tracking to monitor delayed post-release mortality. Our experiments revealed that injury levels, in-net mortality, and post-release mortality tended to increase with net set duration and at higher temperatures. Pike exhibited signs of chronic stress and starvation following retention, particularly at higher temperatures. Total mortality rates were negligible for the 2 d holding period at 14 °C, 14% for 6 d holding at 14 °C, 21% for 2 d holding at 17 °C, and 58% for 6 d holding at 17 °C. No mortality was observed in control fish. Collectively, these data reveal that frequent net tending, particularly at warmer temperatures, may be useful for conserving gamefish populations captured as bycatch in inland hoop net fisheries.

  3. TRENDS IN VARIABILITY OF WATER FLOW OF TELEAJEN RIVER

    Directory of Open Access Journals (Sweden)

    N. JIPA

    2012-03-01

    Full Text Available TRENDS IN VARIABILITY OF WATER FLOW OF TELEAJEN RIVER. In the context of climate change at global and regional scale, this study intends to identify the trends in variability of the annual and monthly flow of Teleajen river. The study is based on processing the series of mean, maximum and minimum flows at Cheia and Moara Domnească hydrometric stations (these data were taken from the National Institute of Meteorology and Hydrology. The period of analysis is 1966-1998, statistical methods beeing mostly used, among which the Mann – Kendall test, that identifies the liniar trend and its statistic significance, comes into focus. The trends in the variability of water annual and monthly flows are highlighted. The results obtained show downward trends for the mean and maximum annual flows, and for the minimum water discharge, a downward trend for Cheia station and an upward trend for Moara Domnească station. Knowing the trends in the variability of the rivers’ flow is important empirically in view of taking adequate administration measures of the water resources and managment measures for the risks lead by extreme hidrologic events (floods, low-water, according to the possible identified changes.

  4. Adiabatic Steam-Water Annular Flow in an Annular Geometry

    DEFF Research Database (Denmark)

    Andersen, P. S.; Würtz, J.

    1981-01-01

    Experimental results for fully developed steam-water annular flow in annular geometries are presented. Rod and tube film flow rates and axial pressure gradients were measured for mass fluxes between 500 and 2000 kg/m2s, steam qualities between 20 and 60 per cent and pressures ranging from 3 to 9...... MPa. It was found that the measured tube film flow rate per unit tube perimeter is always many times greater than the corresponding rod film flow rate. Possible explanations for this asymmetry are discussed....

  5. Continuum simulations of water flow past fullerene molecules

    DEFF Research Database (Denmark)

    Popadic, A.; Praprotnik, M.; Koumoutsakos, P.

    2015-01-01

    We present continuum simulations of water flow past fullerene molecules. The governing Navier-Stokes equations are complemented with the Navier slip boundary condition with a slip length that is extracted from related molecular dynamics simulations. We find that several quantities of interest...... as computed by the present model are in good agreement with results from atomistic and atomistic-continuum simulations at a fraction of the cost. We simulate the flow past a single fullerene and an array of fullerenes and demonstrate that such nanoscale flows can be computed efficiently by continuum flow...

  6. Launch Environment Water Flow Simulations Using Smoothed Particle Hydrodynamics

    Science.gov (United States)

    Vu, Bruce T.; Berg, Jared J.; Harris, Michael F.; Crespo, Alejandro C.

    2015-01-01

    This paper describes the use of Smoothed Particle Hydrodynamics (SPH) to simulate the water flow from the rainbird nozzle system used in the sound suppression system during pad abort and nominal launch. The simulations help determine if water from rainbird nozzles will impinge on the rocket nozzles and other sensitive ground support elements.

  7. Water droplet condensation and evaporation in turbulent channel flow

    NARCIS (Netherlands)

    Russo, E; Kuerten, Johannes G.M.; van der Geld, C.W.M.; Geurts, Bernardus J.

    We propose a point-particle model for two-way coupling of water droplets dispersed in the turbulent flow of a carrier gas consisting of air and water vapour. We adopt an Euler–Lagrangian formulation based on conservation laws for the mass, momentum and energy of the continuous phase and on empirical

  8. Zooplankton data collected from zooplankton net casts in Coastal Waters of Washington / Oregon; 01 January 1969 to 31 December 1972 (NODC Accession 9800078)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton data were collected using zooplankton net casts in Coastal Waters of Washington / Oregon. Data were collected from 01 January 1969 to 31 December 1972 by...

  9. A system for calibrating seepage meters used to measure flow between ground water and surface water

    Science.gov (United States)

    Rosenberry, Donald O.; Menheer, Michael A.

    2006-01-01

    A system has been developed for generating controlled rates of seepage across the sediment-water interface representing flow between ground water and surface water. The seepage- control system facilitates calibration and testing of seepage measurement devices commonly called seepage meters. Two slightly different seepage-control systems were evaluated. Both designs make use of a 1.5-m-diameter by 1.5-m-tall polyethylene flux tank partially filled with sand that overlies a pipe manifold and diffuser plate to provide a uniform flux of water through the sand. The flux tank is filled with water to maintain a water depth above the sand bed of about 0.6 m. Flow is generated by routing water through tubing that connects an adjustable-height reservoir to the base of the flux tank, through the diffuser plate and sand, and across the sediment-water interface. Seepage rate is controlled by maintaining a constant water depth in the reservoir while routing flow between the reservoir and the flux tank. The rate of flow is controlled by adjusting the height of the reservoir with a manually operated fork lift. Flow from ground water to surface water (inflow) occurs when the water surface of the reservoir is higher than the water surface of the flux tank. Flow from surface water to ground water (outflow) occurs when the water surface of the reservoir is lower than the water surface of the flux tank. Flow rates as large as ±55 centimeters per day were generated by adjusting the reservoir to the extremes of the operable range of the fork lift. The minimum seepage velocity that the flowmeter can reliably measure is about 7 centimeters per day.

  10. 75 FR 4173 - Water Quality Standards for the State of Florida's Lakes and Flowing Waters

    Science.gov (United States)

    2010-01-26

    ... Protection Agency 40 CFR Part 131 Water Quality Standards for the State of Florida's Lakes and Flowing Waters...; ] ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 131 RIN 2040-AF11 Water Quality Standards for the State of Florida's...: The Environmental Protection Agency (EPA) is proposing numeric nutrient water quality criteria to...

  11. 75 FR 75761 - Water Quality Standards for the State of Florida's Lakes and Flowing Waters

    Science.gov (United States)

    2010-12-06

    ... Protection Agency 40 CFR Part 131 Water Quality Standards for the State of Florida's Lakes and Flowing Waters...#0;#0; ] ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 131 RIN 2040-AF11 Water Quality Standards for... Regulatory Background C. Water Quality Criteria D. EPA Determination Regarding Florida and EPA's Rulemaking...

  12. Improvements to water use and water stress estimates with the addition of IR and net radiometers to weather stations

    Science.gov (United States)

    Evapotranspiration (ET) is often estimated with the Penman-Monteith (P-M) equation. Net radiation (Rn) is a major component of the surface energy balance and an input to the P-M equation, but it is challenging and expensive to measure accurately. For these reasons, most weather stations do not inclu...

  13. One-Water Hydrologic Flow Model (MODFLOW-OWHM)

    Science.gov (United States)

    Hanson, Randall T.; Boyce, Scott E.; Schmid, Wolfgang; Hughes, Joseph D.; Mehl, Steffen W.; Leake, Stanley A.; Maddock, Thomas; Niswonger, Richard G.

    2014-01-01

    The One-Water Hydrologic Flow Model (MF-OWHM) is a MODFLOW-based integrated hydrologic flow model (IHM) that is the most complete version, to date, of the MODFLOW family of hydrologic simulators needed for the analysis of a broad range of conjunctive-use issues. Conjunctive use is the combined use of groundwater and surface water. MF-OWHM allows the simulation, analysis, and management of nearly all components of human and natural water movement and use in a physically-based supply-and-demand framework. MF-OWHM is based on the Farm Process for MODFLOW-2005 (MF-FMP2) combined with Local Grid Refinement (LGR) for embedded models to allow use of the Farm Process (FMP) and Streamflow Routing (SFR) within embedded grids. MF-OWHM also includes new features such as the Surface-water Routing Process (SWR), Seawater Intrusion (SWI), and Riparian Evapotrasnpiration (RIP-ET), and new solvers such as Newton-Raphson (NWT) and nonlinear preconditioned conjugate gradient (PCGN). This IHM also includes new connectivities to expand the linkages for deformation-, flow-, and head-dependent flows. Deformation-dependent flows are simulated through the optional linkage to simulated land subsidence with a vertically deforming mesh. Flow-dependent flows now include linkages between the new SWR with SFR and FMP, as well as connectivity with embedded models for SFR and FMP through LGR. Head-dependent flows now include a modified Hydrologic Flow Barrier Package (HFB) that allows optional transient HFB capabilities, and the flow between any two layers that are adjacent along a depositional or erosional boundary or displaced along a fault. MF-OWHM represents a complete operational hydrologic model that fully links the movement and use of groundwater, surface water, and imported water for consumption by irrigated agriculture, but also of water used in urban areas and by natural vegetation. Supply and demand components of water use are analyzed under demand-driven and supply

  14. Anuga Software for Numerical Simulations of Shallow Water Flows

    OpenAIRE

    Mungkasi, Sudi; Roberts, Stephen Gwyn

    2012-01-01

    Shallow water flows are governed by the shallow water wave equations, also known as the Saint-Venant system. This paper presents a finite volume method used to solve the two-dimensional shallow water wave equations and how the finite volume method is implemented in ANUGA software. This finite volume method is the numerical method underlying the software. ANUGA is open source software developed by Australian National University (ANU) and Geoscience Australia (GA). This software uses the finite...

  15. ANUGA SOFTWARE FOR NUMERICAL SIMULATIONS OF SHALLOW WATER FLOWS

    OpenAIRE

    Sudi Mungkasi; Stephen Gwyn Roberts

    2012-01-01

    Shallow water flows are governed by the shallow water wave equations, also known as the Saint-Venant system. This paper presents a finite volume method used to solve the two-dimensional shallow water wave equations and how the finite volume method is implemented in ANUGA software. This finite volume method is the numerical method underlying the software. ANUGA is open source software developed by Australian National University (ANU) and Geoscience Australia (GA). This software uses the finite...

  16. Water flow experiments and analyses on the cross-flow type mercury target model with the flow guide plates

    CERN Document Server

    Haga, K; Kaminaga, M; Hino, R

    2001-01-01

    A mercury target is used in the spallation neutron source driven by a high-intensity proton accelerator. In this study, the effectiveness of the cross-flow type mercury target structure was evaluated experimentally and analytically. Prior to the experiment, the mercury flow field and the temperature distribution in the target container were analyzed assuming a proton beam energy and power of 1.5 GeV and 5 MW, respectively, and the feasibility of the cross-flow type target was evaluated. Then the average water flow velocity field in the target mock-up model, which was fabricated from Plexiglass for a water experiment, was measured at room temperature using the PIV technique. Water flow analyses were conducted and the analytical results were compared with the experimental results. The experimental results showed that the cross-flow could be realized in most of the proton beam path area and the analytical result of the water flow velocity field showed good correspondence to the experimental results in the case w...

  17. Boundary of the area contributing flow to the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the boundary of the area contributing ground-water flow to the Death Valley regional ground-water flow-system (DVRFS) model domain. The...

  18. Effect of Water Flows on Ship Traffic in Narrow Water Channels Based on Cellular Automata

    Directory of Open Access Journals (Sweden)

    Hu Hongtao

    2017-11-01

    Full Text Available In narrow water channels, ship traffic may be affected by water flows and ship interactions. Studying their effects can help maritime authorities to establish appropriate management strategies. In this study, a two-lane cellular automation model is proposed. Further, the behavior of ship traffic is analyzed by setting different water flow velocities and considering ship interactions. Numerical experiment results show that the ship traffic density-flux relation is significantly different from the results obtained by classical models. Furthermore, due to ship interactions, the ship lane-change rate is influenced by the water flow to a certain degree.

  19. Behaviour of Corophium volutator in Still versus Flowing Water

    Science.gov (United States)

    Ford, R. B.; Paterson, D. M.

    2001-03-01

    Swimming behaviour in post-settlement Corophium volutator is more frequent at times of flow and is an important process controlling its distribution. It is not known, however, if swimming behaviour differs in still and flowing water, a question whose answer has important consequences for scales of movement of C. volutator. This study investigates the effect of flowing water on the initial 20 min of swimming and settling behaviour of C. volutator. In addition, this study tests the applicability of Gust's Microcosm, a new recirculating flume designed for stability testing of sediments, for use in behavioural observations of organisms in flow. Settling behaviour does not differ between still and flowing water. The same behaviour in flowing water can however result in a 60-fold increase in dispersal distance for the studied site, (from 0·7 to 43 cm) without any increase in time in the water column. Settling has been observed as an active process up to a friction velocity (U *) of 0·75 cm s -1, with C. volutator controlling both their time of entry to and length of time within the water column. Below a U *of 0·75 cm s -1settling is affected by the size of the amphipod. Increased current alone was also observed not to initiate swimming behaviour from non-desirable sediments up to a friction velocity (U *) of 1·02 cm s -1. These findings are discussed in light of their significance in the field. Gust's Microcosm is concluded to create realistic flow conditions for the field and will be useful when suspended sediment loads are low and complete viewing of the behavioural chamber from above is unnecessary.

  20. Performance of 4600-pound-thrust centrifugal-flow-type turbojet engine with water-alcohol injection at inlet

    Science.gov (United States)

    Glasser, Philip W

    1950-01-01

    An experimental investigation of the effects of injecting a water-alcohol mixture of 2:1 at the compressor inlet of a centrifugal-flow type turbojet engine was conducted in an altitude test chamber at static sea-level conditions and at an altitude of 20,000 feet with a flight Mach number of 0.78 with an engine operating at rated speed. The net thrust was augmented by 0.16 for both flight conditions with a ratio of injected liquid to air flow of 0.05. Further increases in the liquid-air ratio did not give comparable increases in thrust.

  1. Investigation of water-water interface in dam break flow with a wet bed

    Science.gov (United States)

    Ye, Zhouteng; Zhao, Xizeng

    2017-05-01

    The evolution of water-water interface between reservoir and ambient water in dam break flow with a wet bed is numerically investigated based on a two-liquid Volume of Fluid (VOF) method. The VOF method is employed to capture both the free surface and water-water interface under Eulerian grids. The modification to VOF method prevents the intersection problem from happening on the water-water interface. The initial stage and long channel propagation of dam break flow are investigated numerically according to the experiments of Jánosi et al. (2004) and Ozmen-Cagatay and Kocaman (2010). The comparison of free surface and water-water interface evolution have good agreement with the published experimental and numerical results. The evolution of water-water interface at the initial stage of dam break flow and the analysis of gate thickness, gate removal velocity and ambient water depth effects are further examined. Besides, propagations of dam break flow in a long channel are investigated, a time difference between the propagation of water-water interface and dam break wave front is found.

  2. Harbor seals (Phoca vitulina can perceive optic flow under water.

    Directory of Open Access Journals (Sweden)

    Nele Gläser

    Full Text Available Optic flow, the pattern of apparent motion elicited on the retina during movement, has been demonstrated to be widely used by animals living in the aerial habitat, whereas underwater optic flow has not been intensively studied so far. However optic flow would also provide aquatic animals with valuable information about their own movement relative to the environment; even under conditions in which vision is generally thought to be drastically impaired, e. g. in turbid waters. Here, we tested underwater optic flow perception for the first time in a semi-aquatic mammal, the harbor seal, by simulating a forward movement on a straight path through a cloud of dots on an underwater projection. The translatory motion pattern expanded radially out of a singular point along the direction of heading, the focus of expansion. We assessed the seal's accuracy in determining the simulated heading in a task, in which the seal had to judge whether a cross superimposed on the flow field was deviating from or congruent with the actual focus of expansion. The seal perceived optic flow and determined deviations from the simulated heading with a threshold of 0.6 deg of visual angle. Optic flow is thus a source of information seals, fish and most likely aquatic species in general may rely on for e. g. controlling locomotion and orientation under water. This leads to the notion that optic flow seems to be a tool universally used by any moving organism possessing eyes.

  3. Experimental measurements of the cavitating flow after horizontal water entry

    Science.gov (United States)

    Tat Nguyen, Thang; Hai, Duong Ngoc; Quang Thai, Nguyen; Phuong, Truong Thi

    2017-10-01

    Water-entry cavitating flow is of considerable importance in underwater high-speed applications. That is because of the drag-reduction effect that concerns the presence of a cavity around moving objects. Though the study of the flow has long been carried out, little data are documented in literature so far. Besides, currently, in the case of unsteady flow, experimental measurements of some flow parameters such as the cavity pressure still encounter difficulties. Hence continuing research efforts are of important significance. The objective of this study is to investigate experimentally the unsteady cavitating flow after the horizontal water entry of projectiles. An experimental apparatus has been developed. Qualitative and quantitative optical visualizations of the flow have been carried out by using high-speed videography. Digital image processing has been applied to analyzing the recorded flow images. Based on the known correlations between the ellipsoidal super-cavity’s size and the corresponding cavitation number, the cavity pressure has been measured by utilizing the data of image processing. A comparison between the partial- and super-cavitating flow regimes is reported. The received results can be useful for the design of high-speed underwater projectiles.

  4. State Token Petri Net modeling method for formal verification of computerized procedure including operator's interruptions of procedure execution flow

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yun Goo [Central Research Institute, Korea Hydro and Nuclear Power Co., LTD, Daejeon (Korea, Republic of); Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2012-12-15

    The Computerized Procedure System (CPS) is one of the primary operating support systems in the digital Main Control Room. The CPS displays procedure on the computer screen in the form of a flow chart, and displays plant operating information along with procedure instructions. It also supports operator decision making by providing a system decision. A procedure flow should be correct and reliable, as an error would lead to operator misjudgement and inadequate control. In this paper we present a modeling for the CPS that enables formal verification based on Petri nets. The proposed State Token Petri Nets (STPN) also support modeling of a procedure flow that has various interruptions by the operator, according to the plant condition. STPN modeling is compared with Coloured Petri net when they are applied to Emergency Operating Computerized Procedure. A converting program for Computerized Procedure (CP) to STPN has been also developed. The formal verification and validation methods of CP with STPN increase the safety of a nuclear power plant and provide digital quality assurance means that are needed when the role and function of the CPS is increasing.

  5. Estimating critical water supply for debris flow initiation in Norway

    Science.gov (United States)

    Meyer, N. K.; Dyrrdal, A. V.; Frauenfelder, R.; Etzelmüller, B.; Nadim, F.

    2012-04-01

    Debris flows frequently affect the Norwegian road and railway infrastructure, especially during spring and autumn. While the debris flow activity in autumn is mainly due to the occurrence of extreme rainfall events, debris flows in spring often occur during periods of rapid snow melt. Existing rainfall threshold values that indicate critical conditions for debris-flow initiation are largely based on precipitation data recorded by meteorological stations. However, during winter the measured amount of precipitation (accumulated as snow) can differ significantly from the actual amount of water that is released to the ground, which is in turn the more critical factor for debris flow initiation. In this study, the data on the actual water supply by the Norwegian Water and Energy Directorate (NVE), and the Norwegian Meteorological Institute (met.no) were used to assess the threshold values. Compared to rainfall data, these data define the hydro-meteorological threshold conditions more accurately throughout the year - i.e. the debris flow triggering conditions due to snow accumulation in autumn and winter and snow melt in spring and summer. Three intensity-duration threshold curves were derived by analyzing the data on 502 past debris flows for water supply durations of 1 to 7 days. Normalization of the data was accomplished using the local "precipitation day normal" to account for regional differences in climate. The minimum threshold indicates the lower boundary above which debris-flow occurrence has been recorded and ranges between 6 and 63 mm/day for different locations and durations. The medium threshold (ranging between 7 and 131 mm/day) characterizes the conditions that are likely to initiate debris flows. Water supply rates exceeding the maximum threshold are regarded as a certain trigger and lie between 12 and 250 mm/day. Based on the obtained threshold curves a frequency analysis over durations of 1, 3 and 7 days for the period 1981-2010 was conducted

  6. Unstable Pore-Water Flow in Intertidal Wetlands

    Science.gov (United States)

    Barry, D. A.; Shen, C.; Li, L.

    2014-12-01

    Salt marshes are important intertidal wetlands strongly influenced by interactions between surface water and groundwater. Bordered by coastal water, the marsh system undergoes cycles of inundation and exposure driven by the tide. This leads to dynamic, complex pore-water flow and solute transport in the marsh soil. Pore-water circulations occur over vastly different spatial and temporal scales with strong link to the marsh topography. These circulations control solute transport between the marsh soil and the tidal creek, and ultimately affect the overall nutrient exchange between the marsh and coastal water. The pore-water flows also dictate the soil condition, particularly aeration, which influences the marsh plant growth. Numerous studies have been carried out to examine the pore-water flow process in the marsh soil driven by tides, focusing on stable flow with the assumption of homogeneity in soil and fluid properties. This assumption, however, is questionable given the actual inhomogeneous conditions in the field. For example, the salinity of surface water in the tidal creek varies temporally and spatially due to the influence of rainfall and evapotranspiration as well as the freshwater input from upland areas to the estuary, creating density gradients across the marsh surface and within the marsh soil. Many marshes possess soil stratigraphy with low-permeability mud typically overlying high-permeability sandy deposits. Macropores such as crab burrows are commonly distributed in salt marsh sediments. All these conditions are prone to the development of non-uniform, unstable preferential pore-water flow in the marsh soil, for example, funnelling and fingering. Here we present results from laboratory experiments and numerical simulations to explore such unstable flow. In particular, the analysis aims to address how the unstable flow modifies patterns of local pore-water movement and solute transport, as well as the overall exchange between the marsh soil and

  7. Gas-Water Flow Behavior in Water-Bearing Tight Gas Reservoirs

    Directory of Open Access Journals (Sweden)

    Renyi Cao

    2017-01-01

    Full Text Available Some tight sandstone gas reservoirs contain mobile water, and the mobile water generally has a significant impact on the gas flowing in tight pores. The flow behavior of gas and water in tight pores is different than in conventional formations, yet there is a lack of adequate models to predict the gas production and describe the gas-water flow behaviors in water-bearing tight gas reservoirs. Based on the experimental results, this paper presents mathematical models to describe flow behaviors of gas and water in tight gas formations; the threshold pressure gradient, stress sensitivity, and relative permeability are all considered in our models. A numerical simulator using these models has been developed to improve the flow simulation accuracy for water-bearing tight gas reservoirs. The results show that the effect of stress sensitivity becomes larger as water saturation increases, leading to a fast decline of gas production; in addition, the nonlinear flow of gas phase is aggravated with the increase of water saturation and the decrease of permeability. The gas recovery decreases when the threshold pressure gradient (TPG and stress sensitivity are taken into account. Therefore, a reasonable drawdown pressure should be set to minimize the damage of nonlinear factors to gas recovery.

  8. Parametric study on flow dispersion of water sprinkle

    Science.gov (United States)

    Tan, R. C.; Khafar, M. H. A.; Abdullah, N. I. S.; Chendang, R. N.; Taib, I.; Asmuin, N.; Ramli, Y.; Seri, S. M.; Mohammed, A. N.

    2017-09-01

    Although water sprinkler is used extensively in agriculture, little effort had been made to improve its performance, resulting in many sprinkler head available at market having less optimum design. Thus, this study aims to improve the basic design of water sprinkler head by conducting a parametric study on the effect of model geometry due to different flow characteristics. A common type of water sprinkler is modelled with computer aided design software and various changes such as enlarging nozzle diameter from 4mm to 8mm, changing vane angle from 70 degrees to 45 degrees are made to the original model. The models were simulated with computational fluid dynamics (CFD) software to investigate how the variation in geometry affects the flow of water and the performance of sprinkler head. The performance of water sprinkler is compared to original model in terms of watering distance, area of spray and velocity of water jet in air. The result of this study shows that enlarge the nozzle diameter have a positive effect on the velocity of water jet in air and the area covered by water jet but it drastically decreases the watering distance of sprinkler. Besides that, changing the angle of vane from 70 degrees to 45 degrees decrease the watering distance slightly and it concentrates the water into a fine jet that cover a small area. To reduce the effect, grooves can be added to the vane to increase the divergence of water spray. Reducing the angle of curvature from 10 degrees to 5 degrees improves the watering distance. The angle of curvature can be reduced more to increase the watering distance further.

  9. Enhancing resilience to water flow uncertainty by integrating environmental flows into water management in the Amudarya River, Central Asia

    Science.gov (United States)

    Schlüter, Maja; Khasankhanova, Gulchekhra; Talskikh, Vladislav; Taryannikova, Raisa; Agaltseva, Natalya; Joldasova, Ilya; Ibragimov, Rustam; Abdullaev, Umid

    2013-11-01

    The wetlands of the Amudarya River delta in Uzbekistan provide valuable ecosystem services to the local human population which has suffered severely from the loss of the Aral Sea, desertification and the post-soviet socio-economic transition. The region is also particularly vulnerable to the impacts of climate change as a recent severe drought has shown. In this contribution, we assess the potential and implications of incorporating environmental flows into management of the Amudarya River for improving the provision of wetland ecosystem services and enhancing resilience of the social-ecological system to river runoff uncertainty. Our assessment is based on analyses of 1) the current vulnerability of deltaic wetlands to years of low water availability, 2) expected regional climate change and its impact on water flows to the wetlands, and 3) alternative water use options to enhance environmental flows under a changing climate. The results provide a ranking of these options with respect to their benefits for the provision of environmental flows and implications for agriculture. Their realization, however, poses challenges that cannot be tackled by technical interventions of redistribution and efficiency increase alone but call for institutional changes and moves towards multi-purpose water use. The diversification of impacts and livelihood options would allow enhancing the resilience of the social-ecological system to climate or socio-politically induced changes in water flow.

  10. Sap flow index as an indicator of water storage use

    Directory of Open Access Journals (Sweden)

    Nadezhdina Nadezhda

    2015-06-01

    Full Text Available Symmetrical temperature difference also known as the sap flow index (SFI forms the basis of the Heat Field Deformation sap flow measurement and is simultaneously collected whilst measuring the sap flow. SFI can also be measured by any sap flow method applying internal continuous heating through the additional installation of an axial differential thermocouple equidistantly around a heater. In earlier research on apple trees SFI was found to be an informative parameter for tree physiological studies, namely for assessing the contribution of stem water storage to daily transpiration. The studies presented in this work are based on the comparative monitoring of SFI and diameter in stems of different species (Pseudotsuga menziesii, Picea omorika, Pinus sylvestris and tree sizes. The ability of SFI to follow the patterns of daily stem water storage use was empirically confirmed by our data. Additionally, as the HFD multipointsensors can measure sap flow at several stem sapwood depths, their use allowed to analyze the use of stored water in different xylem layers through SFI records. Radial and circumferential monitoring of SFI on large cork oak trees provided insight into the relative magnitude and timing of the contribution of water stored in different sapwood layers or stem sectors to transpiration.

  11. Alternate conceptual model of ground water flow at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    Attempts to predict the performance of a high-level nuclear waste repository in the United States have lead to the development of alternative conceptual models of the ground watre flow field in which the repository will be located. This step has come about because of the lage uncertainties involved in predicting the movement of water and radionuclides through an unsaturated fractured rock. Further, one of the standards to which we are comparing performance is probabilistic, so we are forced to try to conceive of all credible scenarios by which ground water may intersect the repository horizon and perhaps transport radionuclides to a given compliance boundary. To simplify this task, the DOE set about identifying alternative conceptual models of ground water flow which are consistent with existing data. Modeling these concepts necessitates the use of simplifying assumptions. Among the modeling assumptions commonly utilized by analysts of the Yucca Mountain site are those of uniformly distributed, small volumes of recharge and matrix or porous media flow. Most scientists would agree that recharge at Yucca Mountain does not occur in this ideal and simplified fashion, yet modeling endeavors continue to commonly utilize this approach. In this paper, we examine the potential effects of focused recharge on the flow field at Yucca Mountain in concert with a fractured matrix and non-equilibrium view of ground water flow.

  12. Flow Accelerated Corrosion: Effect of Water Chemistry and Database Construction

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Hee; Kim, Kyung Mo; Lee, Gyeong Geun; Kim, Dong Jin [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Flow accelerated corrosion (FAC) of carbon steel piping in pressurized water reactors (PWRs) has been a major issue in nuclear industry. Severe accidents at Surry Unit 2 in 1986 and Mihama Unit 3 in 2004 initiated the world wide interest in this area. FAC is a dissolution process of the protective oxide layer on carbon steel or low-alloy steel when these parts are exposed to flowing water (single-phase) or wet steam (two-phase). In a single-phase flow, a scalloped, wavy, or orange peel and in a two-phase flow, tiger striping is observed, respectively. FAC is affected by many parameters, like material composition, pH, dissolved oxygen (DO), flow velocity, system pressure, and steam quality. This paper describes the water chemistry factors influencing on FAC and the database is then constructed using literature data. In order to minimize FAC in NPPs, the optimal method is to control water chemistry parameters. However, quantitative data about FAC have not been published for proprietary reason even though qualitative behaviors of FAC have been well understood. A database was constructed using experimental data in literature. Accurate statistical analysis will be performed using this database to identify the relationship between the FAC rate and test environment.

  13. Water: The Flow of Women's Work. Water in Africa.

    Science.gov (United States)

    Cohen, Amy

    The Water in Africa Project was realized over a 2-year period by a team of Peace Corps volunteers, World Wise Schools (WWS) classroom teachers, and WWS staff members. As part of an expanded, detailed design, resources were collected from over 90 volunteers serving in African countries, photos and stories were prepared, and standards-based learning…

  14. Water Flow Performance of a Superscale Model of the Fastrac Liquid Oxygen Pump

    Science.gov (United States)

    Skelley, Stephen; Zoladz, Thomas

    2001-01-01

    . Likewise, only small circumferential variations in steady-state were observed from 80% to 120% of the design flow coefficient, matching the computational predictions and confirming that the integrated design approach has minimized any exit volute-induced distortions. The test article exhibited suction performance trends typically observed in inducer designs with virtually constant head rise with decreasing inlet pressure until complete pump head breakdown. Unfortunately, the net positive suction head at 3% head fall-off occurred far below that predicted at all tested flow coefficients, resulting in a negative net positive suction head margin at the design point in water. Additional testing to map the unsteady pressure environment was conducted and cavitation-induced flow disturbances at the inducer inlet were observed. Two distinct disturbances were identified, one rotating and one stationary relative to the fixed frame of reference, while the transition from one regime to the next produced significant effects on the steady state pump performance. The impact of the unsteady phenomena and the corresponding energy losses on the unexpectedly poor pump performance is also discussed.

  15. Surface water quality deterioration during low-flow

    Science.gov (United States)

    Hellwig, Jost; Stahl, Kerstin; Lange, Jens

    2017-04-01

    Water quality deterioration during low streamflow has mostly been linked to a lower dilution potential for pollutants. Some studies have also found spatial heterogeneities and a different behavior of different water quality parameters. Even though the general mechanisms that cause water quality changes during low-flow are well understood, only a few efforts have been made to explain the differences in the magnitudes of observed deteriorations. We investigated 72 catchments across the federal state of Baden-Wuerttemberg, Germany, for changes in water quality during low-flow events. Data from the state's water quality monitoring network provided seven water quality parameters (water temperature, electrical conductivity, concentrations of chloride, sodium, sulfate, nitrate and phosphate), which we statistically related to streamflow variability. Water temperatures increased during low flow in summer but decreased during low flow in winter. Nitrate concentrations revealed high spatial heterogeneity with about one third of the stations showing decreasing values during drought. For all other parameters concentrations rose during low-flow with only a few exceptions. Despite consistent trend directions, the magnitudes of changes with streamflow differed markedly across the state. Both multiple linear regression and a multiple analysis of variances were applied to explain these differences with the help of catchment characteristics. Results indicated that for sulfate and conductivity geology of the catchments was the most important control whereas for chloride, sodium and nitrate sewage treatment plants had largest influence. For phosphate no clear control could be identified. Independent from the applied method, land use was a less important control on river water quality during drought than geology or inflow from sewage treatment plants. These results show that the effects of diffuse and point sources, as well as those of natural and anthropogenic sources differ for

  16. Material-property zones used in the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Zones in this data set represent spatially contiguous areas that influence ground-water flow in the Death Valley regional ground-water flow system (DVRFS), an...

  17. A flow cytometry-based screen of nuclear envelope transmembrane proteins identifies NET4/Tmem53 as involved in stress-dependent cell cycle withdrawal.

    Directory of Open Access Journals (Sweden)

    Nadia Korfali

    2011-04-01

    Full Text Available Disruption of cell cycle regulation is one mechanism proposed for how nuclear envelope protein mutation can cause disease. Thus far only a few nuclear envelope proteins have been tested/found to affect cell cycle progression: to identify others, 39 novel nuclear envelope transmembrane proteins were screened for their ability to alter flow cytometry cell cycle/DNA content profiles when exogenously expressed. Eight had notable effects with seven increasing and one decreasing the 4N:2N ratio. We subsequently focused on NET4/Tmem53 that lost its effects in p53(-/- cells and retinoblastoma protein-deficient cells. NET4/TMEM53 knockdown by siRNA altered flow cytometry cell cycle/DNA content profiles in a similar way as overexpression. NET4/TMEM53 knockdown did not affect total retinoblastoma protein levels, unlike nuclear envelope-associated proteins Lamin A and LAP2α. However, a decrease in phosphorylated retinoblastoma protein was observed along with a doubling of p53 levels and a 7-fold increase in p21. Consequently cells withdrew from the cell cycle, which was confirmed in MRC5 cells by a drop in the percentage of cells expressing Ki-67 antigen and an increase in the number of cells stained for ß-galactosidase. The ß-galactosidase upregulation suggests that cells become prematurely senescent. Finally, the changes in retinoblastoma protein, p53, and p21 resulting from loss of NET4/Tmem53 were dependent upon active p38 MAP kinase. The finding that roughly a fifth of nuclear envelope transmembrane proteins screened yielded alterations in flow cytometry cell cycle/DNA content profiles suggests a much greater influence of the nuclear envelope on the cell cycle than is widely held.

  18. Virtual water trade flows and savings under climate change

    Science.gov (United States)

    Konar, Megan; Hussein, Zekarias; Hanasaki, Naota; Mauzerall, Denise; Rodriguez-Iturbe, Ignacio

    2014-05-01

    The international trade of food commodities links water and food systems, with important implications for both water and food security. The embodied water resources associated with food trade are referred to as `virtual water trade'. We present the first study of the impact of climate change on global virtual water trade flows and associated savings for the year 2030. In order to project virtual water trade and savings under climate change, it is essential to obtain projections of both bilateral crop trade and the virtual water content of crops in each country of production. We use the Global Trade Analysis Project model to estimate bilateral crop trade under changes in agricultural productivity for rice, soy, and wheat. We use the H08 global hydrologic model to determine the impact of climatic changes to crop evapotranspiration for rice, soy, and wheat in each country of production. Then, we combine projections of bilateral crop trade with estimates of virtual water content to obtain virtual water trade flows under climate change. We find that the total volume of virtual water trade is likely to go down under climate change, due to decreased crop trade from higher crop prices under scenarios of declining crop yields and due to decreased virtual water content under high agricultural productivity scenarios. However, the staple food trade is projected to save more water across most climate change scenarios, largely because the wheat trade re-organizes into a structure where large volumes of wheat are traded from relatively water-efficient exporters to less efficient importers.

  19. Virtual water trade flows and savings under climate change

    Directory of Open Access Journals (Sweden)

    M. Konar

    2013-08-01

    Full Text Available The international trade of food commodities links water and food systems, with important implications for both water and food security. The embodied water resources associated with food trade are referred to as "virtual water trade". We present the first study of the impact of climate change on global virtual water trade flows and associated savings for the year 2030. In order to project virtual water trade and savings under climate change, it is essential to obtain projections of both bilateral crop trade and the virtual water content of crops in each country of production. We use the Global Trade Analysis Project model to estimate bilateral crop trade under changes in agricultural productivity for rice, soy, and wheat. We use the H08 global hydrologic model to determine the impact of climatic changes to crop evapotranspiration for rice, soy, and wheat in each country of production. Then, we combine projections of bilateral crop trade with estimates of virtual water content to obtain virtual water trade flows under climate change. We find that the total volume of virtual water trade is likely to go down under climate change, due to decreased crop trade from higher crop prices under scenarios of declining crop yields and due to decreased virtual water content under high agricultural productivity scenarios. However, the staple food trade is projected to save more water across most climate change scenarios, largely because the wheat trade re-organizes into a structure where large volumes of wheat are traded from relatively water-efficient exporters to less efficient importers.

  20. Flow based vs. demand based energy-water modelling

    Science.gov (United States)

    Rozos, Evangelos; Nikolopoulos, Dionysis; Efstratiadis, Andreas; Koukouvinos, Antonios; Makropoulos, Christos

    2015-04-01

    The water flow in hydro-power generation systems is often used downstream to cover other type of demands like irrigation and water supply. However, the typical case is that the energy demand (operation of hydro-power plant) and the water demand do not coincide. Furthermore, the water inflow into a reservoir is a stochastic process. Things become more complicated if renewable resources (wind-turbines or photovoltaic panels) are included into the system. For this reason, the assessment and optimization of the operation of hydro-power systems are challenging tasks that require computer modelling. This modelling should not only simulate the water budget of the reservoirs and the energy production/consumption (pumped-storage), but should also take into account the constraints imposed by the natural or artificial water network using a flow routing algorithm. HYDRONOMEAS, for example, uses an elegant mathematical approach (digraph) to calculate the flow in a water network based on: the demands (input timeseries), the water availability (simulated) and the capacity of the transmission components (properties of channels, rivers, pipes, etc.). The input timeseries of demand should be estimated by another model and linked to the corresponding network nodes. A model that could be used to estimate these timeseries is UWOT. UWOT is a bottom up urban water cycle model that simulates the generation, aggregation and routing of water demand signals. In this study, we explore the potentials of UWOT in simulating the operation of complex hydrosystems that include energy generation. The evident advantage of this approach is the use of a single model instead of one for estimation of demands and another for the system simulation. An application of UWOT in a large scale system is attempted in mainland Greece in an area extending over 130×170 km². The challenges, the peculiarities and the advantages of this approach are examined and critically discussed.

  1. Stationary flow solution for water levels in open channels

    NARCIS (Netherlands)

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

    2010-01-01

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

  2. Two - Dimensional Mathematical Model of Water Flow in Open ...

    African Journals Online (AJOL)

    The irrotational flow condition is used for simplification of the system of the governing shallow water equations and the final nonlinear differential equation is solved for the unknown energy head using the finite element method. A one - dimensional problem was solved with diffusion hydraulic model (DHM), energy diffusion ...

  3. Forecasting water flows in Pakistan's Indus River | IDRC ...

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

    2011-07-15

    Jul 15, 2011 ... A Pakistan-Canada research partnership has led to the launch of a sophisticated forecasting system that promises to help Pakistani authorities accurately estimate how much water flows into the Indus River — the lifeline of one of the largest irrigation networks in the world.

  4. Water Flow Simulation using Smoothed Particle Hydrodynamics (SPH)

    Science.gov (United States)

    Vu, Bruce; Berg, Jared; Harris, Michael F.

    2014-01-01

    Simulation of water flow from the rainbird nozzles has been accomplished using the Smoothed Particle Hydrodynamics (SPH). The advantage of using SPH is that no meshing is required, thus the grid quality is no longer an issue and accuracy can be improved.

  5. Water Pipeline Network Analysis Using Simultaneous Loop Flow ...

    African Journals Online (AJOL)

    2013-03-01

    Mar 1, 2013 ... solving for the unknown in water network analysis. It is based on a loop iterative computation. Newton-Raphson method is a better technique for solving the network problems; however, the method adopted here computes simultaneous flow corrections for all loops, hence, the best since the computational.

  6. Climate influences on upper Limpopo River flow | Jury | Water SA

    African Journals Online (AJOL)

    This study demonstrates how the regional climate affects river flow in the upper Limpopo Valley of southern Africa (21–24.5S, 26–30E). The catchment basin receives inflow from the Crocodile, Marico, Mahalapse and Lotsane Rivers, and lies on the eastern fringe of the Kalahari plateau, known for water-deficit conditions.

  7. Hydrogel Regulation of Xylem Water Flow: An Alternative Hypothesis

    NARCIS (Netherlands)

    Doorn, van W.G.; Hiemstra, T.; Fanourakis, D.

    2011-01-01

    The concentration of cations in the xylem sap influences the rate of xylem water flow in angiosperm plants. It has been speculated that this is due to the shrinking and swelling of pectins in the pit membranes. However, there is as yet minimal evidence for the presence of pectin in pit membranes of

  8. Estimation of preferred water flow parameters for four species of ...

    African Journals Online (AJOL)

    Mean water column velocities at each sampled stone were measured using a mini current meter, while flow velocities closer to the boundary layer where blackfly larvae occurred were estimated using indirect techniques (standard hemispheres and aerating tablets). Standard hemispheres were also used to calculate more ...

  9. Characterization of horizontal air–water two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Ran; Kim, Seungjin, E-mail: skim@psu.edu

    2017-02-15

    Highlights: • A visualization study is performed to develop flow regime map in horizontal flow. • Database in horizontal bubbly flow is extended using a local conductivity probe. • Frictional pressure drop analysis is performed in horizontal bubbly flow. • Drift flux analysis is performed in horizontal bubbly flow. - Abstract: This paper presents experimental studies performed to characterize horizontal air–water two-phase flow in a round pipe with an inner diameter of 3.81 cm. A detailed flow visualization study is performed using a high-speed video camera in a wide range of two-phase flow conditions to verify previous flow regime maps. Two-phase flows are classified into bubbly, plug, slug, stratified, stratified-wavy, and annular flow regimes. While the transition boundaries identified in the present study compare well with the existing ones (Mandhane et al., 1974) in general, some discrepancies are observed for bubbly-to-plug/slug, and plug-to-slug transition boundaries. Based on the new transition boundaries, three additional test conditions are determined in horizontal bubbly flow to extend the database by Talley et al. (2015a). Various local two-phase flow parameters including void fraction, interfacial area concentration, bubble velocity, and bubble Sauter mean diameter are obtained. The effects of increasing gas flow rate on void fraction, bubble Sauter mean diameter, and bubble velocity are discussed. Bubbles begin to coalesce near the gas–liquid layer instead of in the highly packed region when gas flow rate increases. Using all the current experimental data, two-phase frictional pressure loss analysis is performed using the Lockhart–Martinelli method. It is found that the coefficient C = 24 yields the best agreement with the data with the minimum average difference. Moreover, drift flux analysis is performed to predict void-weighted area-averaged bubble velocity and area-averaged void fraction. Based on the current database, functional

  10. Assessing changes in water flow regulation in Chongqing region, China.

    Science.gov (United States)

    Xiao, Yang; Xiao, Qiang; Ouyang, Zhiyun; Maomao, Qin

    2015-06-01

    Water flow regulation is an important ecosystem service that significantly impacts on ecological quality and social benefits. With the aim of improving our understanding of ecosystems and proposing strategies for optimizing ecosystem services, a geographic information system (GIS)-based approach was designed to estimate and map regulated water flow in the Chongqing region of China. In this study, we applied the integrated valuation of environmental services and tradeoffs (InVEST) model and mathematical simulations to estimate the provision of the regulated water flow across space and time in 2000, 2005, and 2010. The results indicated that this ecosystem service had improved by 2.07 % from 2000 to 2010 as a result of human activities (such as vegetation restoration) and climatic interaction. Places with positive changes mainly occurred in high mountain areas, whereas places with negative changes were mainly distributed in resettlement areas along the Yangtze River. The type of ecosystem in areas with high mountains and steep slopes was a relatively minor contributor to the total service, but this ecosystem had the higher water flow regulation capacity. Moreover, with the increase in altitude and slope, the percentage contribution of forest increased significantly from 2000 to 2010; by contrast, the percentage contribution of cropland decreased rapidly. As for the impacts, the spatial variation of water flow regulation in the Chongqing region had a significant relation with climate and human activities at the regional scale. These results provided specific information that could be used to strengthen necessary public awareness about the protection and restoration of ecosystems.

  11. Nonequilibrium water dynamics in the rhizosphere: How mucilage affects water flow in soils

    Science.gov (United States)

    Kroener, Eva; Zarebanadkouki, Mohsen; Kaestner, Anders; Carminati, Andrea

    2014-08-01

    The flow of water from soil to plant roots is controlled by the properties of the narrow region of soil close to the roots, the rhizosphere. In particular, the hydraulic properties of the rhizosphere are altered by mucilage, a polymeric gel exuded by the roots. In this paper we present experimental results and a conceptual model of water flow in unsaturated soils mixed with mucilage. A central hypothesis of the model is that the different drying/wetting rate of mucilage compared to the bulk soil results in nonequilibrium relations between water content and water potential in the rhizosphere. We coupled this nonequilibrium relation with the Richards equation and obtained a constitutive equation for water flow in soil and mucilage. To test the model assumptions, we measured the water retention curve and the saturated hydraulic conductivity of sandy soil mixed with mucilage from chia seeds. Additionally, we used neutron radiography to image water content in a layer of soil mixed with mucilage during drying and wetting cycles. The radiographs demonstrated the occurrence of nonequilibrium water dynamics in the soil-mucilage mixture. The experiments were simulated by numerically solving the nonequilibrium model. Our study provides conceptual and experimental evidences that mucilage has a strong impact on soil water dynamics. During drying, mucilage maintains a greater soil water content for an extended time, while during irrigation it delays the soil rewetting. We postulate that mucilage exudation by roots attenuates plant water stress by modulating water content dynamics in the rhizosphere.

  12. Combined effect of virus infection and water stress on water flow and water economy in grapevines.

    Science.gov (United States)

    El Aou-Ouad, Hanan; Pou, Alicia; Tomás, Magdalena; Montero, Rafael; Ribas-Carbo, Miquel; Medrano, Hipólito; Bota, Josefina

    2017-06-01

    Water limitation is one of the major threats affecting grapevine production. Thus, improving water-use efficiency (WUE) is crucial for a sustainable viticulture industry in Mediterranean regions. Under field conditions, water stress (WS) is often combined with viral infections as those are present in major grape-growing areas worldwide. Grapevine leafroll-associated virus 3 (GLRaV-3) is one of the most important viruses affecting grapevines. Indeed, the optimization of water use in a real context of virus infection is an important topic that needs to be understood. In this work, we have focused our attention on determining the interaction of biotic and abiotic stresses on WUE and hydraulic conductance (Kh ) parameters in two white grapevine cultivars (Malvasia de Banyalbufar and Giró Ros). Under well-watered (WW) conditions, virus infection provokes a strong reduction (P < 0.001) in Kpetiole in both cultivars; however, Kleaf was only reduced in Malvasia de Banyalbufar. Moreover, the presence of virus also reduced whole-plant hydraulic conductance (Khplant ) in 2013 and 2014 for Malvasia de Banyalbufar and in 2014 for Giró Ros. Thus, the effect of virus infection on water flow might explain the imposed stomatal limitation. Under WS conditions, the virus effect on Kplant was negligible, because of the bigger effect of WS than virus infection. Whole-plant WUE (WUEWP ) was not affected by the presence of virus neither under WW nor under WS conditions, indicating that plants may adjust their physiology to counteract the virus infection by maintaining a tight stomatal control and by sustaining a balanced carbon change. © 2017 Scandinavian Plant Physiology Society.

  13. Water flows in the Spanish economy: agri-food sectors, trade and households diets in an input-output framework.

    Science.gov (United States)

    Cazcarro, Ignacio; Duarte, Rosa; Sánchez-Chóliz, Julio

    2012-06-19

    Seeking to advance our knowledge of water flows and footprints and the factors underlying them, we apply, on the basis of an extended 2004 Social Accounting Matrix for Spain, an open Leontief model in which households and foreign trade are the exogenous accounts. The model shows the water embodied in products bought by consumers (which we identify with the Water Footprint) and in trade (identified with virtual water trade). Activities with relevant water inflows and outflows such as the agrarian sector, textiles, and the agri-food industry are examined in detail using breakdowns of the relevant accounts. The data reflect only physical consumption, differentiating between green and blue water. The results reveal that Spain is a net importer of water. Flows are then related to key trading partners to show the large quantities involved. The focus on embodied (or virtual) water by activity is helpful to distinguish indirect from direct consumption as embodied water can be more than 300 times direct consumption in some food industry activities. Finally, a sensitivity analysis applied to changes in diets shows the possibility of reducing water uses by modifying households' behavior to encourage healthier eating.

  14. A Guide for Using the Transient Ground-Water Flow Model of the Death Valley Regional Ground-Water Flow System, Nevada and California

    Energy Technology Data Exchange (ETDEWEB)

    Joan B. Blainey; Claudia C. Faunt, and Mary C. Hill

    2006-05-16

    This report is a guide for executing numerical simulations with the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California using the U.S. Geological Survey modular finite-difference ground-water flow model, MODFLOW-2000. Model inputs, including observations of hydraulic head, discharge, and boundary flows, are summarized. Modification of the DVRFS transient ground-water model is discussed for two common uses of the Death Valley regional ground-water flow system model: predictive pumping scenarios that extend beyond the end of the model simulation period (1998), and model simulations with only steady-state conditions.

  15. CFD simulation of horizontal oil-water flow with matched density and medium viscosity ratio in different flow regimes

    OpenAIRE

    Shi, Jing; Gourma, Mustapha; Yeung, Hoi

    2017-01-01

    Simulation of horizontal oil-water flow with matched density and medium viscosity ratio (μo/μw=18.8) in several different flow regimes (core annular flow, oil plugs/bubbles in water and dispersed flow) was performed with the CFD package FLUENT in this study. The volume of fluid (VOF) multiphase flow modeling method in conjunction with the SST k-ω scheme was applied to simulate the oil-water flow. The influences of the turbulence schemes and wall contact angles on the simulation results were i...

  16. Net removal of dissolved organic carbon in the anoxic waters of the Black Sea

    NARCIS (Netherlands)

    Margolin, A.R.; Gerringa, L.J.A.; Hansell, D.A.; Rijkenberg, M.J.A.

    2016-01-01

    Dissolved organic carbon (DOC) concentrations in the deep Black Sea are ~2.5 times higher than found in the globalocean. The two major external sources of DOC are rivers and the Sea of Marmara, a transit point for waters from theMediterranean Sea. In addition, expansive phytoplankton blooms

  17. Continuous-Flow System Produces Medical-Grade Water

    Science.gov (United States)

    Akse, James R.; Dahl, Roger W.; Wheeler, Richard R.

    2009-01-01

    A continuous-flow system utilizes microwave heating to sterilize water and to thermally inactivate endotoxins produced in the sterilization process. The system is designed for use in converting potable water to medical-grade water. Systems like this one could be used for efficient, small-scale production of medical- grade water in laboratories, clinics, and hospitals. This system could be adapted to use in selective sterilization of connections in ultra-pure-water-producing equipment and other equipment into which intrusion by microorganisms cannot be tolerated. Lightweight, port - able systems based on the design of this system could be rapidly deployed to remote locations (e.g., military field hospitals) or in response to emergencies in which the normal infrastructure for providing medical-grade water is disrupted. Larger systems based on the design of this system could be useful for industrial production of medical-grade water. The basic microwave-heating principle of this system is the same as that of a microwave oven: An item to be heated, made of a lossy dielectric material (in this case, flowing water) is irradiated with microwaves in a multimode microwave cavity. The heating is rapid and efficient because it results from absorption of microwave power throughout the volume of the lossy dielectric material. In this system, a copper tube having a length of 49.5 cm and a diameter of 2.25 cm serves as both the microwave cavity and the sterilization chamber. Microwave power is fed via a coaxial cable to an antenna mounted inside the tube at mid-length (see figure). Efficient power transfer occurs due to the shift in wavelength associated with the high permittivity of water combined with the strong coupling of 2.45-GHz microwaves with rotational-vibrational transitions of the dipolar water molecule.

  18. Surfactant-induced flow compromises determination of air-water interfacial areas by surfactant miscible-displacement.

    Science.gov (United States)

    Costanza-Robinson, Molly S; Henry, Eric J

    2017-03-01

    Surfactant miscible-displacement (SMD) column experiments are used to measure air-water interfacial area (AI) in unsaturated porous media, a property that influences solute transport and phase-partitioning. The conventional SMD experiment results in surface tension gradients that can cause water redistribution and/or net drainage of water from the system ("surfactant-induced flow"), violating theoretical foundations of the method. Nevertheless, the SMD technique is still used, and some suggest that experimental observations of surfactant-induced flow represent an artifact of improper control of boundary conditions. In this work, we used numerical modeling, for which boundary conditions can be perfectly controlled, to evaluate this suggestion. We also examined the magnitude of surfactant-induced flow and its impact on AI measurement during multiple SMD flow scenarios. Simulations of the conventional SMD experiment showed substantial surfactant-induced flow and consequent drainage of water from the column (e.g., from 75% to 55% SW) and increases in actual AI of up to 43%. Neither horizontal column orientation nor alternative boundary conditions resolved surfactant-induced flow issues. Even for simulated flow scenarios that avoided surfactant-induced drainage of the column, substantial surfactant-induced internal water redistribution occurred and was sufficient to alter surfactant transport, resulting in up to 23% overestimation of AI. Depending on the specific simulated flow scenario and data analysis assumptions used, estimated AI varied by nearly 40% and deviated up to 36% from the system's initial AI. We recommend methods for AI determination that avoid generation of surface-tension gradients and urge caution when relying on absolute AI values measured via SMD. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Continuum simulations of water flow in carbon nanotube membranes

    DEFF Research Database (Denmark)

    Popadić, A.; Walther, Jens Honore; Koumoutsakos, P-

    2014-01-01

    We propose the use of the Navier–Stokes equations subject to partial-slip boundary conditions to simulate water flows in Carbon NanoTube (CNT) membranes. The finite volume discretizations of the Navier–Stokes equations are combined with slip lengths extracted from molecular dynamics (MD) simulati......We propose the use of the Navier–Stokes equations subject to partial-slip boundary conditions to simulate water flows in Carbon NanoTube (CNT) membranes. The finite volume discretizations of the Navier–Stokes equations are combined with slip lengths extracted from molecular dynamics (MD......) simulations to predict the pressure losses at the CNT entrance as well as the enhancement of the flow rate in the CNT. The flow quantities calculated from the present hybrid approach are in excellent agreement with pure MD results while they are obtained at a fraction of the computational cost. The method...... enables simulations of system sizes and times well beyond the present capabilities of MD simulations. Our simulations provide an asymptotic flow rate enhancement and indicate that the pressure losses at the CNT ends can be reduced by reducing their curvature. More importantly, our results suggest...

  20. Geomorphological control on groundwater flow, transit times and water quality

    Science.gov (United States)

    de Dreuzy, Jean-Raynald; Marçais, Jean; Kolbe, Tamara; Courtois, Quentin; Longuevergne, Laurent; Steer, Philippe; Davy, Philippe; Thomas, Zahra; Le Carlier, Christian; Guillocheau, François; Pinay, Gilles

    2017-04-01

    In weathered zones, subsurface flows remain shallow and strongly depend on the geomorphological evolution of the landscape. Weathered profiles have limited depths. Subsurface circulations follow the structure of the hydrological catchment. Surface and subsurface flows are strongly coupled by rapid responses of saturations to recharge. Some of the circulations are indeed fast with surface/subsurface signatures and transit times of the order of some weeks to some months. Most of the water is however much older as revealed by anthropogenic tracers. For example, in the western crystalline basement of France, characteristic transit times are more of the order of decades. Detailed groundwater flow and transport modelling in well-documented sites show that behaviour of weathered zones is intermediary between hydrology and hydrogeology. While organization of flows is strongly constrained by topography like for hydrology, transit times are however much longer like in hydrogeology. Based on several catchments, we propose quantitative indicators to relate geomorphology with subsurface flow organization. We integrate geological constrains and saturation capacities to derive transit-time dynamics. We discuss the consequences on water quality linked to kinetically-controlled degradation of non-point source contaminants.

  1. Flow enhancement of water flow through silica slit pores with graphene-coated walls

    DEFF Research Database (Denmark)

    Walther, J. H.; Popadic, A.; Koumoutsakos, P.

    We present continuum simulations of water flow past fullerene molecules. The governing Navier-Stokes equations are complemented with the Navier slip bound-ary condition with a slip length that is extracted from related molecular dynamics simulations. We find that several quantities of interest...

  2. What maintains the waters flowing in our rivers?

    Science.gov (United States)

    Vasconcelos, Vitor Vieira

    2017-07-01

    This article discusses how new contributions from hydrogeological science in the 20th and 21st centuries have allowed for a better understanding of the processes that affect the maintenance of river flows. Moreover, the way in which this knowledge has been conveyed beyond academia and has been gradually incorporated into public policy for natural resource management is also discussed. This article explains the development of several approaches used to understand the relationships among the management of aquifers, vegetation and river flows, including water balance, aquifer recharge, the piston effect, seasonal effects, and safe and sustainable yields. Additionally, the current challenges regarding the modeling of hydrological processes that integrate groundwater and surface waters are discussed. Examples of studies applied in Brazil that demonstrate these processes and stimulate thought regarding water management strategies are presented. In light of the case studies, it is possible to propose different strategies, each adapted for specific hydrogeological context to maximize aquifer recharge or base flow maintenance. Based on these strategies, the role of infiltration ponds and other artificial recharge techniques is re-evaluated in the context of the mitigation of environmental impacts on the maintenance of river flows. Proposals for the improvement of public policies regarding the payment of related environmental services to stimulate investment in aquifer recharge and the maintenance of base flow, for which the goal is to attain win-win-win situations for the environment, farmers and water users, while preventing land speculation, are discussed. Lastly, a conceptual model for the dissemination of hydrogeological knowledge in public policies is provided, and its challenges and possibilities are discussed.

  3. Fiscal Year 2013 Net Zero Energy-Water-Waste Portfolio for Fort Leonard Wood

    Science.gov (United States)

    2014-12-01

    Stormwater Management Implement and achieve objectives from USEPA Army Policy Army Sustainable Design and Development Policy, December 2013...facilities with follow-up projects, ERDC/CERL SR-14-11 54 and established stormwater management requirements. EO 13514 extend- ed water reduction...EnEff Stadt (a comprehen- sive approach to urban areas with local and district heating networks), the World Bank Energy Sector Management Assistance

  4. Hydroelectric power plant with variable flow on drinking water adduction

    Science.gov (United States)

    Deaconu, S. I.; Babău, R.; Popa, G. N.; Gherman, P. L.

    2018-01-01

    The water feeding system of the urban and rural localities is mainly collected with feed pipes which can have different lengths and different levels. Before using, water must be treated. Since the treatment take place in the tanks, the pressure in the inlet of the station must be diminished. Many times the pressure must be reduced with 5-15 Barr and this is possible using valves, cavils, and so on. The flow capacity of the water consumption is highly fluctuating during one day, depending on the season, etc. This paper presents a method to use the hydroelectric potential of the feed pipes using a hydraulic turbine instead of the classical methods for decreasing the pressure. To avoid the dissipation of water and a good behavior of the power parameters it is used an asynchronous generator (AG) which is coupled at the electrical distribution network through a static frequency converter (SFC). The turbine has a simple structure without the classical devices (used to regulate the turbine blades). The speed of rotation is variable, depending on the necessary flow capacity in the outlet of the treatment station. The most important element of the automation is the static frequency converter (SFC) which allows speeds between 0 and 1.5 of the rated speed of rotation and the flow capacity varies accordingly with it.

  5. Modelling effects of seasonal variation in water table depth on net ecosystem CO2 exchange of a tropical peatland

    Science.gov (United States)

    Mezbahuddin, M.; Grant, R. F.; Hirano, T.

    2014-02-01

    Seasonal variation in water table depth (WTD) determines the balance between aggradation and degradation of tropical peatlands. Longer dry seasons together with human interventions (e.g. drainage) can cause WTD drawdowns making tropical peatland C storage highly vulnerable. Better predictive capacity for effects of WTD on net CO2 exchange is thus essential to guide conservation of tropical peat deposits. Mathematical modelling of basic eco-hydrological processes under site-specific conditions can provide such predictive capacity. We hereby deploy a process-based mathematical model ecosys to study effects of seasonal variation in WTD on net ecosystem productivity (NEP) of a drainage affected tropical peat swamp forest at Palangkaraya, Indonesia. Simulated NEP suggested that the peatland was a C source (NEP ~ -2 g C m-2 d-1, where a negative sign represents a C source and a positive sign a C sink) during rainy seasons with shallow WTD, C neutral or a small sink (NEP ~ +1 g C m-2 d-1) during early dry seasons with intermediate WTD and a substantial C source (NEP ~ -4 g C m-2 d-1) during late dry seasons with deep WTD from 2002 to 2005. These values were corroborated by regressions (P 0.8, intercepts approaching 0 and slopes approaching 1. We also simulated a gradual increase in annual NEP from 2002 (-609 g C m-2) to 2005 (-373 g C m-2) with decreasing WTD which was attributed to declines in duration and intensity of dry seasons following the El Niño event of 2002. This increase in modelled NEP was corroborated by EC-gap filled annual NEP estimates. Our modelling hypotheses suggested that (1) poor aeration in wet soils during shallow WTD caused slow nutrient (predominantly phosphorus) mineralization and consequent slow plant nutrient uptake that suppressed gross primary productivity (GPP) and hence NEP (2) better soil aeration during intermediate WTD enhanced nutrient mineralization and hence plant nutrient uptake, GPP and NEP and (3) deep WTD suppressed NEP through a

  6. Nonlinear analysis of gas-water/oil-water two-phase flow in complex networks

    CERN Document Server

    Gao, Zhong-Ke; Wang, Wen-Xu

    2014-01-01

    Understanding the dynamics of multi-phase flows has been a challenge in the fields of nonlinear dynamics and fluid mechanics. This chapter reviews our work on two-phase flow dynamics in combination with complex network theory. We systematically carried out gas-water/oil-water two-phase flow experiments for measuring the time series of flow signals which is studied in terms of the mapping from time series to complex networks. Three network mapping methods were proposed for the analysis and identification of flow patterns, i.e. Flow Pattern Complex Network (FPCN), Fluid Dynamic Complex Network (FDCN) and Fluid Structure Complex Network (FSCN). Through detecting the community structure of FPCN based on K-means clustering, distinct flow patterns can be successfully distinguished and identified. A number of FDCN’s under different flow conditions were constructed in order to reveal the dynamical characteristics of two-phase flows. The FDCNs exhibit universal power-law degree distributions. The power-law exponent ...

  7. Catchment organisation, free energy dynamics and network control on critical zone water flows

    Science.gov (United States)

    Zehe, E.; Ehret, U.; Kleidon, A.; Jackisch, C.; Scherer, U.; Blume, T.

    2012-04-01

    as that these flow structures organize and dominate flows of water, dissolved matter and sediments during rainfall driven conditions at various scales: - Surface connected vertical flow structures of anecic worm burrows or soil cracks organize and dominated vertical flows at the plot scale - this is usually referred to as preferential flow; - Rill networks at the soil surface organise and dominate hillslope scale overland flow response and sediment yields; - Subsurface pipe networks at the bedrock interface organize and dominate hillslope scale lateral subsurface water and tracer flows; - The river net organizes and dominates flows of water, dissolved matter and sediments to the catchment outlet and finally across continental gradients to the sea. Fundamental progress with respect to the parameterization of hydrological models, subscale flow networks and to understand the adaptation of hydro-geo ecosystems to change could be achieved by discovering principles that govern the organization of catchments flow networks in particular at least during steady state conditions. This insight has inspired various scientists to suggest principles for organization of ecosystems, landscapes and flow networks; as Bejans constructural law, Minimum Energy Expenditure , Maximum Entropy Production. In line with these studies we suggest that a thermodynamic/energetic treatment of the catchment is might be a key for understanding the underlying principles that govern organisation of flow and transport. Our approach is to employ a) physically based hydrological model that address at least all the relevant hydrological processes in the critical zone in a coupled way, behavioural representations of the observed organisation of flow structures and textural elements, that are consistent with observations in two well investigated research catchments and have been tested against distributed observations of soil moisture and catchment scale discharge; to simulate the full concert of hydrological

  8. Analysis of a solar collector field water flow network

    Science.gov (United States)

    Rohde, J. E.; Knoll, R. H.

    1976-01-01

    A number of methods are presented for minimizing the water flow variation in the solar collector field for the Solar Building Test Facility at the Langley Research Center. The solar collector field investigated consisted of collector panels connected in parallel between inlet and exit collector manifolds to form 12 rows. The rows were in turn connected in parallel between the main inlet and exit field manifolds to complete the field. The various solutions considered included various size manifolds, manifold area change, different locations for the inlets and exits to the manifolds, and orifices or flow control valves. Calculations showed that flow variations of less than 5 percent were obtainable both inside a row between solar collector panels and between various rows.

  9. Modelling water flow under glaciers and ice sheets

    Science.gov (United States)

    Flowers, Gwenn E.

    2015-01-01

    Recent observations of dynamic water systems beneath the Greenland and Antarctic ice sheets have sparked renewed interest in modelling subglacial drainage. The foundations of today's models were laid decades ago, inspired by measurements from mountain glaciers, discovery of the modern ice streams and the study of landscapes evacuated by former ice sheets. Models have progressed from strict adherence to the principles of groundwater flow, to the incorporation of flow ‘elements’ specific to the subglacial environment, to sophisticated two-dimensional representations of interacting distributed and channelized drainage. Although presently in a state of rapid development, subglacial drainage models, when coupled to models of ice flow, are now able to reproduce many of the canonical phenomena that characterize this coupled system. Model calibration remains generally out of reach, whereas widespread application of these models to large problems and real geometries awaits the next level of development. PMID:27547082

  10. Dinoflagellate bioluminescence in response to mechanical stimuli in water flows

    Directory of Open Access Journals (Sweden)

    A. S. Cussatlegras

    2005-01-01

    Full Text Available Bioluminescence of plankton organisms induced by water movements has long been observed and is still under investigations because of its great complexity. In particular, the exact mechanism occurring at the level of the cell has not been yet fully understood. This work is devoted to the study of the bioluminescence of the dinoflagellates plankton species Pyrocystis noctiluca in response to mechanical stimuli generated by water flows. Several experiments were performed with different types of flows in a Couette shearing apparatus. All of them converge to the conclusion that stationary homogeneous laminar shear does not trigger massive bioluminescence, but that acceleration and shear are both necessary to stimulate together an intense bioluminescence response. The distribution of the experimental bioluminescence thresholds is finally calculated from the light emission response for the Pyrocystis noctiluca species.

  11. Ground-water flow and quality near Canon City, Colorado

    Science.gov (United States)

    Hearne, G.A.; Litke, D.W.

    1987-01-01

    Water in aquifers that underlie the Lincoln Park area near Canon City, Colorado, contains measurable concentrations of chemical constituents that are similar to those in raffinate (liquid waste) produced by a nearby uranium ore processing mill. The objective of this study was to expand the existing geohydrologic data base by collecting additional geohydrologic and water quality, in order to refine the description of the geohydrologic and geochemical systems in the study area. Geohydrologic data were collected from nine tests wells drilled in the area between the U.S. Soil Conservation Service dam and Lincoln Park. Lithologic and geophysical logs of these wells indicated that the section of Vermejo Formation penetrated consisted of interbedded sandstone and shale. The sandstone beds had a small porosity and small hydraulic conductivity. Groundwater flow from the U.S. Soil Conservation Service dam to Lincoln Park seemed to be along an alluvium-filled channel in the irregular and relatively undescribed topography of the Vermejo Formation subcrop. North of the De Weese Dye Ditch, the alluvium becomes saturated and groundwater generally flows to the northeast. Water samples from 28 sites were collected and analyzed for major ions and trace elements; selected water samples also were analyzed for stable isotopes; samples were collected from wells near the uranium ore processing mill, from privately owned wells in Lincoln Park, and from the test wells drilled in the intervening area. Results from the quality assurance samples indicate that cross-contamination between samples from different wells was avoided and that the data are reliable. Water in the alluvial aquifer underlying Lincoln Park is mainly a calcium bicarbonate type. Small variations in the composition of water in the alluvial aquifer appears to result from a reaction of water leaking from the De Weese Dye Ditch with alluvial material. Upward leakage from underlying aquifers does not seem to be significant in

  12. Denitrification in wood chip bioreactors at different water flows.

    Science.gov (United States)

    Greenan, Colin M; Moorman, Thomas B; Parkin, Timothy B; Kaspar, Thomas C; Jaynes, Dan B

    2009-01-01

    Subsurface drainage in agricultural watersheds exports a large quantity of nitrate-nitrogen (NO(3)-N) and concentrations frequently exceed 10 mg L(-1). A laboratory column study was conducted to investigate the ability of a wood chip bioreactor to promote denitrification under mean water flow rates of 2.9, 6.6, 8.7 and 13.6 cm d(-1) which are representative of flows entering subsurface drainage tiles. Columns were packed with wood chips and inoculated with a small amount of oxidized till and incubated at 10 degrees C. Silicone sampling cells at the effluent ports were used for N(2)O sampling. (15)Nitrate was added to dosing water at 50 mg L(-1) and effluent was collected and analyzed for NO(3)-N, NH(4)-N, and dissolved organic carbon. Mean NO(3)-N concentrations in the effluent were 0.0, 18.5, 24.2, and 35.3 mg L(-1) for the flow rates 2.9, 6.6, 8.7, and 13.6 cm d(-1), respectively, which correspond to 100, 64, 52, and 30% efficiency of removal. The NO(3)-N removal rates per gram of wood increased with increasing flow rates. Denitrification was found to be the dominant NO(3)-N removal mechanism as immobilization of (15)NO(3)-N was negligible compared with the quantity of (15)NO(3)-N removed. Nitrous oxide production from the columns ranged from 0.003 to 0.028% of the N denitrified, indicating that complete denitrification generally occurred. Based on these observations, wood chip bioreactors may be successful at removing significant quantities of NO(3)-N, and reducing NO(3)-N concentration from water moving to subsurface drainage at flow rates observed in central Iowa subsoil.

  13. Control algorithm for multiscale flow simulations of water

    DEFF Research Database (Denmark)

    Kotsalis, E. M.; Walther, Jens Honore; Kaxiras, E.

    2009-01-01

    We present a multiscale algorithm to couple atomistic water models with continuum incompressible flow simulations via a Schwarz domain decomposition approach. The coupling introduces an inhomogeneity in the description of the atomistic domain and prevents the use of periodic boundary conditions....... The use of a mass conserving specular wall results in turn to spurious oscillations in the density profile of the atomistic description of water. These oscillations can be eliminated by using an external boundary force that effectively accounts for the virial component of the pressure. In this Rapid...

  14. Translational versus rotational energy flow in water solvation dynamics

    Science.gov (United States)

    Rey, Rossend; Hynes, James T.

    2017-09-01

    Early molecular dynamics simulations discovered an important asymmetry in the speed of water solvation dynamics for charge extinction and charge creation for an immersed solute, a feature representing a first demonstration of the breakdown of linear response theory. The molecular level mechanism of this asymmetry is examined here via a novel energy flux theoretical approach coupled to geometric probes. The results identify the effect as arising from the translational motions of the solute-hydrating water molecules rather than their rotational/librational motions, even though the latter are more rapid and dominate the energy flow.

  15. Contributions to flow techniques and mass spectrometry in water analysis

    OpenAIRE

    Santos, Inês Carvalho dos

    2015-01-01

    In this thesis, the use of different flow systems was exploited along with the use of different detection techniques for the development of simple, robust, and automated analytical procedures. With the purpose to perform in-line sample handling and pretreatment operations, different separation units were used. The main target for these methods was waters samples. The first procedure was based on a sequential injection analysis (SIA) system for carbon speciation (alkalinity, dis...

  16. Electrokinetic instability in microchannel ferrofluid/water co-flows

    Science.gov (United States)

    Song, Le; Yu, Liandong; Zhou, Yilong; Antao, Asher Reginald; Prabhakaran, Rama Aravind; Xuan, Xiangchun

    2017-04-01

    Electrokinetic instability refers to unstable electric field-driven disturbance to fluid flows, which can be harnessed to promote mixing for various electrokinetic microfluidic applications. This work presents a combined numerical and experimental study of electrokinetic ferrofluid/water co-flows in microchannels of various depths. Instability waves are observed at the ferrofluid and water interface when the applied DC electric field is beyond a threshold value. They are generated by the electric body force that acts on the free charge induced by the mismatch of ferrofluid and water electric conductivities. A nonlinear depth-averaged numerical model is developed to understand and simulate the interfacial electrokinetic behaviors. It considers the top and bottom channel walls’ stabilizing effects on electrokinetic flow through the depth averaging of three-dimensional transport equations in a second-order asymptotic analysis. This model is found accurate to predict both the observed electrokinetic instability patterns and the measured threshold electric fields for ferrofluids of different concentrations in shallow microchannels.

  17. Topology changes in a water-oil swirling flow

    Science.gov (United States)

    Carrión, Luis; Herrada, Miguel A.; Shtern, Vladimir N.

    2017-03-01

    This paper reveals the flow topology hidden in the experimental study by Fujimoto and Takeda ["Topology changes of the interface between two immiscible liquid layers by a rotating lid," Phys. Rev. E 80, 015304(R) (2009)]. Water and silicone oil fill a sealed vertical cylindrical container. The rotating top disk induces the meridional circulation and swirl of both fluids. As the rotation strength Reo increases, the interface takes shapes named, by the authors, hump, cusp, Mt. Fuji, and bell. Our numerical study reproduces the interface geometry and discloses complicated flow patterns. For example at Reo = 752, where the interface has the "Mt. Fuji" shape, the water motion has three bulk cells and the oil motion has two bulk cells. This topology helps explain the interface geometry. In addition, our study finds that the steady axisymmetric flow suffers from the shear-layer instability for Reo > 324, i.e., before the interface becomes remarkably deformed. The disturbance energy is concentrated in the water depth. This explains why the instability does not significantly affect the interface shape in the experiment.

  18. Experimental investigation of stabilization of flowing water temperature with a water-PCM heat exchanger

    Directory of Open Access Journals (Sweden)

    Charvat Pavel

    2014-03-01

    Full Text Available Experiments have been carried out in order to investigate the stabilization of water temperature with a water-PCM heat exchanger. The water-PCM heat exchanger was of a rather simple design. It was a round tube, through which the water flowed, surrounded with an annular layer of PCM. The heat exchanger was divided into one meter long segments (modules and the water temperature was monitored at the outlet of each of the segments. A paraffin-based PCM with the melting temperature of 42 °C was used in the experiments. The experimental set-up consisted of two water reservoirs kept at different temperatures, the water-PCM heat exchanger, PC controlled valves and a data acquisition system. As the first step a response to a step change in the water temperature at the inlet of the heat exchanger was investigated. Subsequently, a series of experiments with a square wave change of temperature at the inlet of the exchanger were carried out. The square wave temperature profile was achieved by periodic switching between the two water reservoirs. Several amplitudes and periods of temperature square wave were used. The results of experiments show that a water-PCM heat exchanger can effectively be used to stabilize the flowing water temperature when the inlet temperature changes are around the melting range of the PCM.

  19. Assessing the urban water balance: the Urban Water Flow Model and its application in Cyprus.

    Science.gov (United States)

    Charalambous, Katerina; Bruggeman, Adriana; Lange, Manfred A

    2012-01-01

    Modelling the urban water balance enables the understanding of the interactions of water within an urban area and allows for better management of water resources. However, few models today provide a comprehensive overview of all water sources and uses. The objective of the current paper was to develop a user-friendly tool that quantifies and visualizes all water flows, losses and inefficiencies in urban environments. The Urban Water Flow Model was implemented in a spreadsheet and includes a water-savings application that computes the contributions of user-selected saving options to the overall water balance. The model was applied to the coastal town of Limassol, Cyprus, for the hydrologic years 2003/04-2008/09. Data were collected from the different authorities and hydrologic equations and estimations were added to complete the balance. Average precipitation was 363 mm/yr, amounting to 25.4 × 10(6)m(3)/yr, more than double the annual potable water supply to the town. Surface runoff constituted 29.6% of all outflows, while evapotranspiration from impervious areas was 21.6%. Possible potable water savings for 2008/09 were estimated at 5.3 × 10(3) m(3), which is 50% of the total potable water provided to the area. This saving would also result in a 6% reduction of surface runoff.

  20. Modeling of Kinetics of Air Entrainment in Water Produced by Vertically Falling Water Flow

    Directory of Open Access Journals (Sweden)

    Adelė VAIDELIENĖ

    2014-09-01

    Full Text Available This study analyzes the process of air entrainment in water caused by vertically falling water flow in the free water surface. The new kinetic model of air entrainment in water was developed. This model includes the process of air entrapment, as well as air removal, water sputtering and resorption. For the experimental part of this study a new method based on digital image processing was developed. Theoretical and experimental methods were used for determining air concentration and its distribution in water below the air-water interface. A new presented mathematical model of air entrainment process allows determining of air bubbles and water droplets concentrations distribution. The obtained theoretical and experimental results were in good agreement. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4871

  1. Early regimes of water capillary flow in slit silica nanochannels.

    Science.gov (United States)

    Oyarzua, Elton; Walther, Jens H; Mejía, Andrés; Zambrano, Harvey A

    2015-06-14

    Molecular dynamics simulations are conducted to investigate the initial stages of spontaneous imbibition of water in slit silica nanochannels surrounded by air. An analysis is performed for the effects of nanoscopic confinement, initial conditions of liquid uptake and air pressurization on the dynamics of capillary filling. The results indicate that the nanoscale imbibition process is divided into three main flow regimes: an initial regime where the capillary force is balanced only by the inertial drag and characterized by a constant velocity and a plug flow profile. In this regime, the meniscus formation process plays a central role in the imbibition rate. Thereafter, a transitional regime takes place, in which, the force balance has significant contributions from both inertia and viscous friction. Subsequently, a regime wherein viscous forces dominate the capillary force balance is attained. Flow velocity profiles identify the passage from an inviscid flow to a developing Poiseuille flow. Gas density profiles ahead of the capillary front indicate a transient accumulation of air on the advancing meniscus. Furthermore, slower capillary filling rates computed for higher air pressures reveal a significant retarding effect of the gas displaced by the advancing meniscus.

  2. Mechanisms of flow and water mass variability in Denmark Strait

    Science.gov (United States)

    Moritz, Martin; Jochumsen, Kerstin; Quadfasel, Detlef; Mashayekh Poul, Hossein; Käse, Rolf H.

    2017-04-01

    The dense water export through Denmark Strait contributes significantly to the lower limb of the Atlantic Meridional Overturning Circulation. Overflow water is transported southwestward not only in the deep channel of the Strait, but also within a thin bottom layer on the Greenland shelf. The flow on the shelf is mainly weak and barotropic, exhibiting many recirculations, but may eventually contribute to the overflow layer in the Irminger Basin by spilling events in the northern Irminger Basin. Especially the circulation around Dohrn Bank and the Kangerdlussuaq Trough contribute to the shelf-basin exchange. Moored observations show the overflow in Denmark Strait to be stable during the last 20 years (1996-2016). Nevertheless, flow variability was noticed on time scales of eddies and beyond, i.e. on weekly and interannual scales. Here, we use a combination of mooring data and shipboard hydrographic and current data to address the dominant modes of variability in the overflow, which are (i) eddies, (ii) barotropic pulsations of the plume, (iii) lateral shifts of the plume core position, and (iv) variations in vertical extension, i.e. varying overflow thickness. A principle component analysis is carried out and related to variations in sea surface height and wind stress, derived from satellite measurements. Furthermore, a test for topographic waves is performed. Shelf contributions to the overflow core in the Irminger Basin are identified from measurements of temperature and salinity, as well as velocity, which were obtained during recent cruises in the region. The flow and water mass pattern obtained from the observational data is compared to simulations in a high resolution regional model (ROMS), where tracer release experiments and float deployments were carried out. The modelling results allow a separation between different atmospheric forcing modes (NAO+ vs NAO- situations), which impact the water mass distribution and alter the dense water pathways on the

  3. 77 FR 74449 - Water Quality Standards for the State of Florida's Lakes and Flowing Waters; Proposed Rule; Stay

    Science.gov (United States)

    2012-12-14

    ... AGENCY 40 CFR Part 131 RIN 2040-AF41 Water Quality Standards for the State of Florida's Lakes and Flowing... regulation the ``Water Quality Standards for the State of Florida's Lakes and Flowing Waters; Final Rule... Information Does this action apply to me? Citizens concerned with water quality in Florida may be interested...

  4. 75 FR 45579 - Water Quality Standards for the State of Florida's Lakes and Flowing Waters; Supplemental Notice...

    Science.gov (United States)

    2010-08-03

    ... AGENCY 40 CFR Part 131 RIN 2040-AF11 Water Quality Standards for the State of Florida's Lakes and Flowing... 26, 2010, notice of proposed rulemaking (NPRM), proposing numeric nutrient water quality criteria to..., ``Water Quality Standards for the State of Florida's Lakes and Flowing Waters.'' This supplemental notice...

  5. Effects of rainfall on water quality in six sequentially disposed fishponds with continuous water flow

    Directory of Open Access Journals (Sweden)

    LH. Sipaúba-Tavares

    Full Text Available An investigation was carried out during the rainy period in six semi-intensive production fish ponds in which water flowed from one pond to another without undergoing any treatment. Eight sampling sites were assigned at pond outlets during the rainy period (December-February. Lowest and highest physical and chemical parameters of water occurred in pond P1 (a site near the springs and in pond P4 (a critical site that received allochthonous material from the other ponds and also from frog culture ponds, respectively. Pond sequential layout caused concentration of nutrients, chlorophyll-a and conductivity. Seasonal rains increased the water flow in the ponds and, consequently, silted more particles and other dissolved material from one fish pond to another. Silting increased limnological variables from P3 to P6. Although results suggest that during the period under analysis, rainfall affected positively the ponds' water quality and since the analyzed systems have been aligned in a sequential layout with constant water flow from fish ponds and parallel tanks without any previous treatment, care has to be taken so that an increase in rain-induced water flow does not have a contrary effect in the fish ponds investigated.

  6. Altitudes of the top of model layers for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the altitudes of the tops of 16 model layers simulated in the Death Valley regional ground-water flow system (DVRFS) transient flow...

  7. ANUGA SOFTWARE FOR NUMERICAL SIMULATIONS OF SHALLOW WATER FLOWS

    Directory of Open Access Journals (Sweden)

    Sudi Mungkasi

    2012-07-01

    Full Text Available Shallow water flows are governed by the shallow water wave equations, also known as the Saint-Venant system. This paper presents a finite volume method used to solve the two-dimensional shallow water wave equations and how the finite volume method is implemented in ANUGA software. This finite volume method is the numerical method underlying the software. ANUGA is open source software developed by Australian National University (ANU and Geoscience Australia (GA. This software uses the finite volume method with triangular domain discretisation for the computation. Four test cases are considered in order to evaluate the performance of the software. Overall, ANUGA is a robust software to simulate two-dimensional shallow water flows. Arus air dangkal diatur dalam persamaan gelombang air dangkal, dikenal sebagai sistem Saint-Venant. Penelitian ini menyajikan metode finite volumeyang digunakan untuk menyelesaikan persamaan gelombang air dangkal dua dimensi dan bagaimana metode finite volumediimplementasikan dalam perangkat lunak ANUGA. Metode finite volumeadalah metode numerik yang mendasari perangkat lunakANUGA. ANUGA sendiri adalah perangkat lunak open source yang dikembangkan oleh Australian National University(ANU dan Geoscience Australia (GA. Perangkat lunak ini menggunakan metode finite volumedengan diskritisasi domain segitiga dalam proseskomputasi. Empat uji kasus digunakan untuk mengevaluasi kinerja perangkat lunak. Secara keseluruhan, ANUGA adalah perangkat lunak yang robust untuk mensimulasikan dua dimensi aliran arus air dangkal.

  8. Water Resource Inventory and Assessment - Flow Map Poster: Ankeny National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This flow map depicts the flow and control of water on Ankeny National Wildlife Refuge. It was produced as part of the Water Resource Inventory and Assessment...

  9. Subregions of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the subregions of the transient ground-water flow model of the Death Valley regional ground-water flow system (DVRFS). Subregions are...

  10. Water Resource Inventory and Assessment - Flow Map Poster: William L. Finley National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This flow map depicts the flow and control of water on William L. Finley National Wildlife Refuge. It was produced as part of the Water Resource Inventory and...

  11. Numerical study of saturation steam/water mixture flow and flashing initial sub-cooled water flow inside throttling devices

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    In this work, a Computational Fluid-Dynamics (CFD) approach to model this phenomenon inside throttling devices is proposed. To validate CFD results, different nozzle geometries are analyzed, comparing numerical results with experimental data. Two cases are studied: Case 1: saturation steam/water mixture flow inside 2D convergent-divergent nozzle (inlet, outlet and throat diameter of nozzle are 0.1213m, 0.0452m and 0.0191m respectively). In this benchmark, a range of total inle...

  12. Water flow in soil from organic dairy rotations

    DEFF Research Database (Denmark)

    Lamandé, Mathieu; Eriksen, Jørgen; Krogh, Paul Henning

    2017-01-01

    Managed grasslands are characterized by rotations of leys and arable crops. The regime of water flow evolves during the leys because of earthworm and root activity, climate and agricultural practices (fertilizer, cutting and cattle trampling). The effects of duration of the leys, cattle trampling...... and fertilizer practice on the movement of water through sandy loam soil profiles were investigated in managed grassland of a dairy operation. Experiments using tracer chemicals were performed, with or without cattle slurry application, with cutting or grazing, in the 1st and the 3rd year of ley, and in winter...... rye. Each plot was irrigated for an hour with 18·5 mm of water containing a conservative tracer, potassium bromide; 24 h after irrigation, macropores >1 mm were recorded visually on a horizontal plan of 0·7 m2 at five depths (10, 30, 40, 70 and 100 cm). The bromide (Br−) concentration in soil was also...

  13. Seasonal trends of light-saturated net photosynthesis and stomatal conductance of loblolly pine trees grown in contrasting environments of nutrition, water and carbon dioxide

    Science.gov (United States)

    Ramesh Murthy; Stanley J. Zarnoch; P.M. Dougherty

    1997-01-01

    Repeated measures analysis was used to evaluate the effect of long-term CO2 enhancement on seasonal trends of light-saturated rates of net photosynthesis (Asat) and stomatal conductance to water vapour (gsat) of 9-year-old loblolly pine (Pinus taeda L.; trees grown in a 2x2...

  14. Evaluating renewable natural resources flow and net primary productivity with a GIS-Emergy approach: A case study of Hokkaido, Japan.

    Science.gov (United States)

    Wang, Chengdong; Zhang, Shenyan; Yan, Wanglin; Wang, Renqing; Liu, Jian; Wang, Yutao

    2016-11-18

    Renewable natural resources, such as solar radiation, rainfall, wind, and geothermal heat, together with ecosystem services, provide the elementary supports for the sustainable development of human society. To improve regional sustainability, we studied the spatial distributions and quantities of renewable natural resources and net primary productivity (NPP) in Hokkaido, which is the second largest island of Japan. With the help of Geographic Information System (GIS) software, distribution maps for each type of renewable natural resource were generated by kriging interpolation based on statistical records. A composite map of the flow of all types of renewable natural resources was also generated by map layer overlapping. Additionally, we utilized emergy analysis to convert each renewable flow with different attributes into a unified unit (i.e., solar equivalent joules [sej]). As a result, the spatial distributions of the flow of renewable natural resources of the Hokkaido region are presented in the form of thematic emergy maps. Thus, the areas with higher renewable emergy can be easily visualized and identified. The dominant renewable flow in certain areas can also be directly distinguished. The results can provide useful information for regional sustainable development, environmental conservation and ecological management.

  15. Evaluating renewable natural resources flow and net primary productivity with a GIS-Emergy approach: A case study of Hokkaido, Japan

    Science.gov (United States)

    Wang, Chengdong; Zhang, Shenyan; Yan, Wanglin; Wang, Renqing; Liu, Jian; Wang, Yutao

    2016-11-01

    Renewable natural resources, such as solar radiation, rainfall, wind, and geothermal heat, together with ecosystem services, provide the elementary supports for the sustainable development of human society. To improve regional sustainability, we studied the spatial distributions and quantities of renewable natural resources and net primary productivity (NPP) in Hokkaido, which is the second largest island of Japan. With the help of Geographic Information System (GIS) software, distribution maps for each type of renewable natural resource were generated by kriging interpolation based on statistical records. A composite map of the flow of all types of renewable natural resources was also generated by map layer overlapping. Additionally, we utilized emergy analysis to convert each renewable flow with different attributes into a unified unit (i.e., solar equivalent joules [sej]). As a result, the spatial distributions of the flow of renewable natural resources of the Hokkaido region are presented in the form of thematic emergy maps. Thus, the areas with higher renewable emergy can be easily visualized and identified. The dominant renewable flow in certain areas can also be directly distinguished. The results can provide useful information for regional sustainable development, environmental conservation and ecological management.

  16. Power plant intakes performance in low flow water bodies

    Directory of Open Access Journals (Sweden)

    Yasser M. Shawky

    2015-04-01

    Full Text Available This research aims to study the hot water recirculation at the power plants intakes due to the discharge from the plant cooling system into a low flow receiving water body. To achieve this objective, a 3Dnumerical model was employed to study the effect of the main parameters in this phenomena such as the plant intake length (L, the distance between the plant intake and outfall (S, the water depth under the intake skimmer wall (h and the water depth just upstream the intake (D on the recirculation of hot water to the plant intake. Eight scenarios were tested and two mathematical formulas accounting for the effect of these parameters on the hot water concentration at the plant intake were deduced. Physical model tests were carried out to verify the accuracy of the two deduced formulas. The study results indicated that the measured thermal concentrations in the physical model tests coincide with those calculated by the two above-mentioned mathematical formulas.

  17. Nitrogen distribution and cycling through water flows in a subtropical bamboo forest under high level of atmospheric deposition.

    Directory of Open Access Journals (Sweden)

    Li-hua Tu

    Full Text Available BACKGROUND: The hydrological cycle is an important way of transportation and reallocation of reactive nitrogen (N in forest ecosystems. However, under a high level of atmospheric N deposition, the N distribution and cycling through water flows in forest ecosystems especially in bamboo ecosystems are not well understood. METHODOLOGY/PRINCIPAL FINDINGS: In order to investigate N fluxes through water flows in a Pleioblastus amarus bamboo forest, event rainfall/snowfall (precipitation, PP, throughfall (TF, stemflow (SF, surface runoff (SR, forest floor leachate (FFL, soil water at the depth of 40 cm (SW1 and 100 cm (SW2 were collected and measured through the whole year of 2009. Nitrogen distribution in different pools in this ecosystem was also measured. Mean N pools in vegetation and soil (0-1 m were 351.7 and 7752.8 kg ha(-1. Open field nitrogen deposition at the study site was 113.8 kg N ha(-1 yr(-1, which was one of the highest in the world. N-NH4(+, N-NO3(- and dissolved organic N (DON accounted for 54%, 22% and 24% of total wet N deposition. Net canopy accumulated of N occurred with N-NO3(- and DON but not N-NH4(+. The flux of total dissolved N (TDN to the forest floor was greater than that in open field precipitation by 17.7 kg N ha(-1 yr(-1, due to capture of dry and cloudwater deposition net of canopy uptake. There were significant negative exponential relationships between monthly water flow depths and monthly mean TDN concentrations in PP, TF, SR, FFL and SW1. CONCLUSIONS/SIGNIFICANCE: The open field nitrogen deposition through precipitation is very high over the world, which is the main way of reactive N input in this bamboo ecosystem. The water exchange and N consume mainly occurred in the litter floor layer and topsoil layer, where most of fine roots of bamboo distributed.

  18. Energy saving for OpenFlow switch on the NetFPGA platform based on queue engineering.

    Science.gov (United States)

    Vu, Tran Hoang; Luc, Vu Cong; Quan, Nguyen Trung; Thanh, Nguyen Huu; Nam, Pham Ngoc

    2015-01-01

    Data centers play an important role in our daily activities. The increasing demand on data centers in both scale and size has led to huge energy consumption that rises the cost of data centers. Besides, environmental impacts also increase considerably due to a large amount of carbon emissions. In this paper, we present a design aimed at green networking by reducing the power consumption for routers and switches. Firstly, we design the Balance Switch on the NetFPGA platform to save consumed energy based on Queue Engineering. Secondly, we design the test-bed system to precisely measure the consumed energy of our switches. Experimental results show that energy saving of our switches is about 30% - 35% of power consumption according to variation of input traffic compared with normal Openflow Switch. Finally, we describe performance evaluations.

  19. Water-tunnel study of transition flow around circular cylinders

    Science.gov (United States)

    Almosnino, D.; Mcalister, K. W.

    1984-01-01

    The recently reported phenomenon of asymmetric flow separation from a circular cylinder in the critical Reynolds number regime has been confirmed in a water-tunnel experiment. For the first time, an attempt was made to visualize the wake of the cylinder during the transition from subcritical to critical flow and to correlate the visualizations with lift and drag measurements. The occurrence of a dominant asymmetric-flow state was quite repeatable, both when increasing and decreasing the Reynolds number, resulting in a mean lift coefficient of C sub L approx 1.2 and a shift in the angle of the wake by about 12 deg. A distinctive step change in the drag and shedding frequency was also found to occur. A hysteresis was confirmed to exist in this region as the Reynolds number was cycled over the transition range. Both boundaries of the asymmetry appear to be supercritical bifurcations in the flow. The asymmetry was normally steady in the mean; however, there were instances when the direction of the asymmetry reversed and remained so for the duration of the Reynolds number sweep through this transition region. A second asymmetry was observed at a higher Reynolds number; however, the mean lift coefficient was much lower, and the direction of the asymmetry was not observed to reverse. Introducing a small local disturbance into the boundary layer was found to prevent the critical asymmetry from developing along the entire span of the cylinder.

  20. Flow-induced vibration of component cooling water heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, Y.S.; Chen, S.S. (Taiwan Power Co., Taipei (Taiwan). Nuclear Engineering Dept.; Argonne National Lab., IL (USA))

    1990-01-01

    This paper presents an evaluation of flow-induced vibration problems of component cooling water heat exchangers in one of Taipower's nuclear power stations. Specifically, it describes flow-induced vibration phenomena, tests to identify the excitation mechanisms, measurement of response characteristics, analyses to predict tube response and wear, various design alterations, and modifications of the original design. Several unique features associated with the heat exchangers are demonstrated, including energy-trapping modes, existence of tube-support-plate (TSP)-inactive modes, and fluidelastic instability of TSP-active and -inactive modes. On the basis of this evaluation, the difficulties and future research needs for the evaluation of heat exchangers are identified. 11 refs., 19 figs., 3 tabs.

  1. Impacts of climate and land use change on ecosystem hydrology and net primary productivity: Linking water availability to food security in Asia

    Science.gov (United States)

    Dangal, S. R. S.; Tian, H.; Pan, S.; Zhang, B.; Yang, J.

    2015-12-01

    The nexus approach to food, water and energy security in Asia is extremely important and relevant as the region has to feed two-third of the world's population and accounts for 59% of the global water consumption. The distribution pattern of food, water and energy resources have been shaped by the legacy effect of both natural and anthropogenic disturbances and therefore are vulnerable to climate change and human activities including land use/cover change (LUCC) and land management (irrigation and nitrogen fertilization). In this study, we used the Dynamic Land Ecosystem Model (DLEM) to examine the effects of climate change, land use/cover change, and land management practices (irrigation and nitrogen fertilization) on the spatiotemporal trends and variability in water availability and its role in limiting net primary productivity (NPP) and food security in the 20th and early 21st centuries. Our specific objectives are to quantify how climate change, LUCC and other environmental changes have interactively affected carbon and water dynamics across the Asian region. In particular, we separated the Asian region into several sub-region based on the primary limiting factor - water, food and energy. We then quantified how changes in environmental factors have altered the water and food resources during the past century. We particularly focused on Net Primary Productivity (NPP) and water cycle (Evapotranspiration, discharge, and runoff) as a measure of available food and water resources, respectively while understanding the linkage between food and water resources in Asia.

  2. Effect of Floating Vegetation on Wind Flow and Wave in Closed Water Body

    OpenAIRE

    Ozaki, Akinori; Mori, Ken; Hirai, Yasumaru; Hamagami, Kunihiko

    2009-01-01

    When we address a water quality problem in some closed water bodies, it is very important to solve the relationship between the disturbances and flow. Turbulent and convective flows may be induced by mechanical and thermal disturbances, respectively. Disturbances induce the circulation flow of water environmental substance and the water quality depends on this circulation. It is considered that when a mechanical disturbance act on the water surface, the generation of turbulent energy at the w...

  3. Model grid and infiltration values for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the model grid and infiltration values simulated in the transient ground-water flow model of the Death Valley regional ground-water...

  4. Discharge areas for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set represents discharge areas in the Death Valley regional ground-water flow system (DVRFS) transient model. Natural ground-water discharge occurs...

  5. Net Locality

    DEFF Research Database (Denmark)

    de Souza e Silva, Adriana Araujo; Gordon, Eric

    Provides an introduction to the new theory of Net Locality and the profound effect on individuals and societies when everything is located or locatable. Describes net locality as an emerging form of location awareness central to all aspects of digital media, from mobile phones, to Google Maps...... of emerging technologies, from GeoCities to GPS, Wi-Fi, Wiki Me, and Google Android....

  6. Net Neutrality

    DEFF Research Database (Denmark)

    Savin, Andrej

    2017-01-01

    Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else.......Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else....

  7. Simple and Multiple Water Fuel Emulsions Preparation in Helical Flow

    OpenAIRE

    DLUSKA, Ewa; WRONSKI, Robert HUBACZ and Stanislaw; HUBACZ, Robert

    2014-01-01

    This paper presents a method of simple and multiple water fuel emulsions preparation in a liquid-liquid contactor with Couette-Taylor flow (CTF contactor). This method concerns the integration of the CTF contactor with diesel engines for the injection of just-prepared emulsions. Stable simple O/W and multiple O/W/O emulsions, both with quite narrow drop size distribution, have been prepared. The strong influence of operating conditions in the CTF contactor on mean drop size of the d...

  8. Comparing efficacy of a sweep net and a dip method for collection of mosquito larvae in large bodies of water in South Africa [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Katherine K. Brisco

    2016-04-01

    Full Text Available In this study we tested an alternative method for collecting mosquito larvae called the sweep net catch method and compared its efficiency to that of the traditional dip method. The two methods were compared in various water bodies within Kruger National Park and Lapalala Wilderness area, South Africa. The sweep net catch method performed 5 times better in the collection of Anopheles larvae and equally as well as the dip method in the collection of Culex larvae (p =8.58 x 10-5. Based on 15 replicates the collector’s experience level did not play a significant role in the relative numbers of larvae collected using either method. This simple and effective sweep net catch method will greatly improve the mosquito larval sampling capacity in the field setting.

  9. Numerical simulation of water and sand blowouts when penetrating through shallow water flow formations in deep water drilling

    Science.gov (United States)

    Ren, Shaoran; Liu, Yanmin; Gong, Zhiwu; Yuan, Yujie; Yu, Lu; Wang, Yanyong; Xu, Yan; Deng, Junyu

    2018-02-01

    In this study, we applied a two-phase flow model to simulate water and sand blowout processes when penetrating shallow water flow (SWF) formations during deepwater drilling. We define `sand' as a pseudo-component with high density and viscosity, which can begin to flow with water when a critical pressure difference is attained. We calculated the water and sand blowout rates and analyzed the influencing factors from them, including overpressure of the SWF formation, as well as its zone size, porosity and permeability, and drilling speed (penetration rate). The obtained data can be used for the quantitative assessment of the potential severity of SWF hazards. The results indicate that overpressure of the SWF formation and its zone size have significant effects on SWF blowout. A 10% increase in the SWF formation overpressure can result in a more than 90% increase in the cumulative water blowout and a 150% increase in the sand blowout when a typical SWF sediment is drilled. Along with the conventional methods of well flow and pressure control, chemical plugging, and the application of multi-layer casing, water and sand blowouts can be effectively reduced by increasing the penetration rate. As such, increasing the penetration rate can be a useful measure for controlling SWF hazards during deepwater drilling.

  10. GeoSteamNet: A computer code to simulate geothermal steam flow in a pipeline network; GeoSteamNet: Programa de computo para simular el flujo de vapor geotermico de una red de vaporductos

    Energy Technology Data Exchange (ETDEWEB)

    Verma P., Mahendra; Aragon A., Alfonso [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: mahendra@iie.org.mx; Ruiz L., Alejando; Mendoza C., Alfredo [Comision Federal de Electricidad, Campo Geotermico Los Azufres, Campamento Agua Fria, Michoacan (Mexico)

    2011-07-15

    A computer package, GeoSteamNet, was developed to simulate steam transport in a pipeline network of a geothermal field. The fluid motion is governed by the following basic principles: conservation of mass, linear momentum principle (Newton's second law or the Navier Stokes equations), and the first and second laws of thermodynamics. The second law of thermodynamics defines the direction of a spontaneous process, which is indirectly validated in the algorithm as vapor flows from high-to-low pressure, and heat flows from high-to-low temperatures. The nonlinear equations are solved with the Newton-Raphson method. Using the ActiveX component OrificeMeter, the steam-flow balance was calculated for power plants U-15 and U-16 in Los Azufres Geothermal Field, Mich., in February 2009. U-15 was fed by the production wells AZ-04, AZ-28, AZ-30, AZ-65D, and AZ-66, whereas wells AZ-28A, AZ-45, AZ-56, AZ-67, AZ-69D were connected to U-16. The analytical error is within {+-}4%, which is acceptable for practical purposes for steam-supply management, considering the uncertainties in parameters, such as pressure, temperature, pressure fluctuation at the wellhead, etc. The steam simulation results by GeoSteamNet for a hypothetical-pipeline network in a geothermal system with two production wells and a power plant illustrate its functionality. Several points need to be emphasized. For a specific geometry-pipeline network, there is only a certain amount of mass (vapor) that can be transported at a given pressure at the wellheads and the power plant. The construction and modification of a pipeline network is very expensive and the production of geothermal wells depends on many natural factors; therefore, there is need to conduct a tolerance study for each component of the network. A simulation study of the virtual-pipeline network for the design of a geothermal power plant can save money, effort, and time. [Spanish] Se desarrollo un paquete de computo, GeoSteamNet, para simular el

  11. Characterization of ground-water flow between the Canisteo Mine Pit and surrounding aquifers, Mesabi Iron Range, Minnesota

    Science.gov (United States)

    Jones, Perry M.

    2002-01-01

    The U.S. Geological Survey, in cooperation with the Minnesota Department of Natural Resources, conducted a study to characterize ground-water flow conditions between the Canisteo Mine Pit, Bovey, Minnesota, and surrounding aquifers following mine abandonment. The objective of the study was to estimate the amount of steady-state, ground-water flow between the Canisteo Mine Pit and surrounding aquifers at pit water-level altitudes below the level at which surface-water discharge from the pit may occur. Single-well hydraulic tests and stream-hydrograph analyses were conducted to estimate horizontal hydraulic conductivities and ground-water recharge rates, respectively, for glacial aquifers surrounding the mine pit. Average hydraulic conductivity values ranged from 0.05 to 5.0 ft/day for sands and clays and from 0.01 to 121 ft/day for coarse sands, gravels, and boulders. The 15-year averages for the estimated annual recharge using the winter records and the entire years of record for defining baseflow recession rates were 7.07 and 7.58 in., respectively. These recharge estimates accounted for 25 and 27 percent, respectively, of the average annual precipitation for the 1968-82 streamflow monitoring period. Ground-water flow rates into and out of the mine pit were estimated using a calibrated steady-state, ground-water flow model simulating an area of approximately 75 mi2 surrounding the mine pit. The model residuals, or difference between simulated and measured water levels, for 15 monitoring wells adjacent to the mine pit varied between +28.65 and –3.78 ft. The best-match simulated water levels were within 4 ft of measured water levels for 9 of the 15 wells, and within 2 ft for 4 of the wells. The simulated net ground-water flow into the Canisteo Mine Pit was +1.34 ft3/s, and the net ground-water flow calculated from pit water levels measured between July 5, 1999 and February 25, 2001 was +5.4 ft3/s. Simulated water levels and ground-water flow to and from the mine

  12. Microscale Modelling of Water and Gas-Water Flows in Subsea Sand Sediment

    Science.gov (United States)

    Sato, T.; Sugita, T.; Hirabayashi, S.; Nagao, J.; Jin, Y.; Kiyono, F.

    2009-12-01

    Methane hydrate is a promising energy resource in the near future. Its production is a current hot topic and flow of methane gas with water in sediment sand layer is very important to predict the production rate. In this study, permeability of microscale sand layer was numerically simulated by a three-dimensional lattice Boltzmann method. Shapes of real sands were extracted by series expansion of spherical harmonics using CT-scan images of real subsea core samples. These extracted sands were located in a cubic lattice domain by a simulated annealing method to fit to given porosities. Pressure difference was imposed at the both end faces of the domain to flow water and methane gas. By this simulation, permeability of water phase and water-gas two-phase flow were analysed and compared well with existing models. This work was financially supported by Japan's Methane Hydrate R&D Program planned by Ministry of Economy, Trade and Industry (METI). 3D image of an extracted frame-sand grain Distribution of gas and water phases in computational domain for Sw=0.80

  13. Boundary of the ground-water flow model by IT Corporation (1996), for the Death Valley regional ground-water flow system study, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the boundary of the steady-state ground-water flow model built by IT Corporation (1996). The regional, 20-layer ground-water flow model...

  14. Tangible Landscape: Cognitively Grasping the Flow of Water

    Science.gov (United States)

    Harmon, B. A.; Petrasova, A.; Petras, V.; Mitasova, H.; Meentemeyer, R. K.

    2016-06-01

    Complex spatial forms like topography can be challenging to understand, much less intentionally shape, given the heavy cognitive load of visualizing and manipulating 3D form. Spatiotemporal processes like the flow of water over a landscape are even more challenging to understand and intentionally direct as they are dependent upon their context and require the simulation of forces like gravity and momentum. This cognitive work can be offloaded onto computers through 3D geospatial modeling, analysis, and simulation. Interacting with computers, however, can also be challenging, often requiring training and highly abstract thinking. Tangible computing - an emerging paradigm of human-computer interaction in which data is physically manifested so that users can feel it and directly manipulate it - aims to offload this added cognitive work onto the body. We have designed Tangible Landscape, a tangible interface powered by an open source geographic information system (GRASS GIS), so that users can naturally shape topography and interact with simulated processes with their hands in order to make observations, generate and test hypotheses, and make inferences about scientific phenomena in a rapid, iterative process. Conceptually Tangible Landscape couples a malleable physical model with a digital model of a landscape through a continuous cycle of 3D scanning, geospatial modeling, and projection. We ran a flow modeling experiment to test whether tangible interfaces like this can effectively enhance spatial performance by offloading cognitive processes onto computers and our bodies. We used hydrological simulations and statistics to quantitatively assess spatial performance. We found that Tangible Landscape enhanced 3D spatial performance and helped users understand water flow.

  15. Seasonal and Topographic Variation in Net Primary Productivity and Water Use Efficiency in a Southwest Sky Island Fores

    Science.gov (United States)

    Murphy, P.; Minor, R. L.; Sanchez-Canete, E. P.; Potts, D. L.; Barron-Gafford, G.

    2016-12-01

    Western North American Forests represent an uncertain sink for atmospheric carbon. While understanding of the physical drivers of productivity in these forests has grown in the last decade, the relative influence of topographic position in the complex terrain of montane systems remains understudied. The high-latitude mixed conifer forest ecosystems of the southern Arizona Madrean Sky Islands are characterized by low precipitation, high annual variation in temperature, and heterogeneous topography. Eddy covariance measurements these forests show distinct seasonal trends due to temperature and bi-modal precipitation patterns, but these measurements are unable to resolve potential differences in physiological function on opposing north and south aspects within the footprint of the tower. Most of the year, north aspects receive less energy input due to the oblique angle of incoming solar radiation, leading to a divergence in soil moistures and temperatures. However, overall movement of energy and material is much higher on these north aspects on an annual basis. The implications of these differences for net primary productivity (NPP) and water use efficiency (WUE) are poorly addressed in the literature. We evaluated the relative control that topography has on the physical environment (soil moisture and temperature) and how these factors affect water stress, NPP, and WUE. We combined leaf-level measurements of photosynthesis and transpiration with other physiological and meteorological measurements to determine how the dominant vegetation functions as a result of microclimatic conditions. Initial results from the spring and summer measurement periods suggest topographical differences in microclimate, resulting in differences in NPP in the spring, but not the summer. Also, each of the three species on the same aspect responded differently to the same microclimatic conditions, underscoring interspecific variation at the site. How might these patterns change throughout an

  16. An Investigation of the Water Flow Past the Butterfly Valve

    Science.gov (United States)

    Chaiworapuek, Weerachai; Champagne, Jean-Yves; El Haj em, Mahmoud; Kittichaikan, Chawalit

    2010-06-01

    This paper presents a numerical simulation of flow past the butterfly valve using Commercial Fluid Dynamics software FLUENT. In static analysis, the positions of the disk were set to be 0° (completely opened), 30°, 45°, 60° and 75° under 1, 2 and 3 m/s water speed. The angular velocities were set to be 0.039 and 1.57 rad/s under 1 m/s water speed in dynamic analysis. The study focuses on the investigation of the characteristic of loss coefficient and torque behavior of the 150 mm and 300 mm in diameter butterfly valves. From the results obtained, it was found that the loss coefficient and torque increased when the disk angle was increased. By increasing the water speed, the loss coefficient remained constant while the torque increased. In dynamic analysis of both angular speeds, the maximum torque occurred at 70°-80° in closing turn and 100°-110° in opening turn. The experiment was also carried out to verify the numerical results. By comparing between the experimental and numerical results, it was found that the loss coefficients and torques obtained from these methods were similar.

  17. Modelling the Flow of Water in Stratified Layers of Sand | Popoola ...

    African Journals Online (AJOL)

    The phenomenon of deflection of flow of water in porous media of different porosities with porosity ratio,Ψ , is similar to the fact that there is deviation in fluid flow in a pair of media of different densities. Theoretically, the relationship between preferred direction of flow of water,Θ , and the sand layers of porosity ratio, Ψ was ...

  18. A Potential Approach for Low Flow Selection in Water Resource Supply and Management

    Science.gov (United States)

    Ying Ouyang

    2012-01-01

    Low flow selections are essential to water resource management, water supply planning, and watershed ecosystem restoration. In this study, a new approach, namely the frequent-low (FL) approach (or frequent-low index), was developed based on the minimum frequent-low flow or level used in minimum flows and/or levels program in northeast Florida, USA. This FL approach was...

  19. The effect of surfactants on upward air-water pipe flow at various inclinations

    NARCIS (Netherlands)

    van Nimwegen, A.T.; Portela, L.; Henkes, R.A.W.M.

    2016-01-01

    In this work, we extend our previous efforts on the effect of surfactants on air-water flow in a vertical pipe by also considering pipe inclinations between 20° (with respect to horizontal) and vertical. For air-water flow, independent of the inclination, there is a regular annular flow at large

  20. Instream water use in the United States: water laws and methods for determining flow requirements

    Science.gov (United States)

    Lamb, Berton L.; Doerksen, Harvey R.

    1987-01-01

    Water use generally is divided into two primary classes - offstream use and instream use. In offstream use, sometimes called out-of-stream or diversionary use, water is withdrawn (diverted) from a stream or aquifer and transported to the place of use. Examples are irrigated agriculture, municipal water supply, and industrial use. Each of these offstream uses, which decreases the volume of water available downstream from the point of diversion, is discussed in previous articles in this volume. Instream use, which generally does not diminish the flow downstream from its point of use, and its importance are described in this article. One of the earliest instream uses of water in the United States was to turn the water wheels that powered much of the Nation's industry in the 18th and 19th centuries. Although a small volume of water might have been diverted to a mill near streamside, that water usually was returned to the stream near the point of diversion and, thus, the flow was not diminished downstream from the mill. Over time, the generation of hydroelectric power replaced mill wheels as a means of converting water flow into energy. Since the 1920's, the generation of hydroelectric power increasingly has become a major instream use of water. By 1985, more than 3 billion acre-feet of water (3,050,000 million gallons per day) was used annually for hydropower generation (Solley and others, 1988, p. 45)-enough water to cover the State of Colorado to a depth of 51 feet. Navigation is another instream use with a long history. The Lewis and Clark expedition journals and many of Mark Twain's novels illustrate the extent to which the Nation originally depended on adequate streamfiows for basic transportation. Navigation in the 1980's is still considered to be an instream use; however, it often is based upon a stream system that has been modified greatly through channelization, diking, and construction of dams and locks. The present (1987) inland water navigation system in

  1. Interacting effects of elevated temperature and additional water on plant physiology and net ecosystem carbon fluxes in a high Arctic ecosystem

    Science.gov (United States)

    Maseyk, Kadmiel; Seibt, Ulrike; Lett, Céline; Lupascu, Massimo; Czimczik, Claudia; Sullivan, Patrick; Welker, Jeff

    2013-04-01

    Arctic ecosystems are experiencing temperature increases more strongly than the global average, and increases in precipitation are also expected amongst the climate impacts on this region in the future. These changes are expected to strongly influence plant physiology and soil biogeochemistry with subsequent implications for system carbon balance. We have investigated the effects of a long-term (10 years) increase in temperature, soil water and the combination of both on a tundra ecosystem at a field manipulation experiment in NW Greenland. Leaf gas exchange, chlorophyll fluorescence, carbon (C) and nitrogen (N) content and leaf isotopic composition, and leaf morphology were measured on Salix arctica plants in treatment and control plots in June-July 2011, and continuous measurements of net plant and soil fluxes of CO2 and water were made using automatic chambers coupled to a trace gas laser analyzer. Plants in the elevated temperature (T2) treatment had the highest photosynthetic capacity in terms of net CO2 assimilation rates and photosystem II efficiencies, and lowest rates of non-photochemical energy dissipation during photosynthesis. T2 plants also had the highest leaf N content, specific leaf area (SLA) and saturation light level of photosynthesis. It appears that warming increases soil N availability, which the plants direct towards increasing photosynthetic capacity and producing larger thinner leaves. On the other hand, the plants in the plots with both elevated temperatures and additional water (T2W) had the lowest photosystem II efficiencies and the highest rates of non-photochemical energy dissipation, due more to higher levels of constitutive energy dissipation than regulated thermal quenching. Watering, both in combination with higher temperatures and alone (W treatment), also reduced leaf SLA and leaf N relative to control plots. However, net photosynthetic rates remained similar to control plants, due in part to higher stomatal conductance (W) and

  2. Impacts of changing cropping pattern on virtual water flows related to crops transfer: a case study for the Hetao irrigation district, China.

    Science.gov (United States)

    Liu, Jing; Wu, Pute; Wang, Yubao; Zhao, Xining; Sun, Shikun; Cao, Xinchun

    2014-11-01

    Analysis of cropping patterns is a prerequisite for their optimisation, and evaluation of virtual water flows could shed new light on water resources management. This study is intended to explore the effects of cropping pattern changes between 1960 and 2008 on virtual water flows related to crops transfer in the Hetao irrigation district, China. (1) The sown area of crops increased at an average rate of 3.57 × 10(3) ha year(-1) while the proportion of sown grain crops decreased from 92.83% in the 1960s to 50.22% in the 2000s. (2) Virtual water content decreased during the study period while net virtual water exports increased since the 1980s. (3) Assuming that the cropping pattern was constant and was equal to the average 1960s value, accumulated net virtual water export in 1980-2008 would have been 4.76 × 10(9) m(3) greater than that in the actual cropping pattern scenario. Cropping pattern changes in the Hetao irrigation district could not only be seen as resulting from the pursuit for higher economic returns, but also as a feedback response to limited water resources. A systematic framework is still needed for future cropping pattern planning by taking food security, continued agricultural expansion and other constraints into consideration. © 2014 Society of Chemical Industry.

  3. Water flows, energy demand, and market analysis of the informal water sector in Kisumu, Kenya.

    Science.gov (United States)

    Sima, Laura C; Kelner-Levine, Evan; Eckelman, Matthew J; McCarty, Kathleen M; Elimelech, Menachem

    2013-03-01

    In rapidly growing urban areas of developing countries, infrastructure has not been able to cope with population growth. Informal water businesses fulfill unmet water supply needs, yet little is understood about this sector. This paper presents data gathered from quantitative interviews with informal water business operators (n=260) in Kisumu, Kenya, collected during the dry season. Sales volume, location, resource use, and cost were analyzed by using material flow accounting and spatial analysis tools. Estimates show that over 76% of the city's water is consumed by less than 10% of the population who have water piped into their dwellings. The remainder of the population relies on a combination of water sources, including water purchased directly from kiosks (1.5 million m3 per day) and delivered by hand-drawn water-carts (0.75 million m3 per day). Energy audits were performed to compare energy use among various water sources in the city. Water delivery by truck is the highest per cubic meter energy demand (35 MJ/m3), while the city's tap water has the highest energy use overall (21,000 MJ/day). We group kiosks by neighborhood and compare sales volume and cost with neighborhood-level population data. Contrary to popular belief, we do not find evidence of price gouging; the lowest prices are charged in the highest-demand low-income area. We also see that the informal sector is sensitive to demand, as the number of private boreholes that serve as community water collection points are much larger where demand is greatest.

  4. Water flow algorithm decision support tool for travelling salesman problem

    Science.gov (United States)

    Kamarudin, Anis Aklima; Othman, Zulaiha Ali; Sarim, Hafiz Mohd

    2016-08-01

    This paper discuss about the role of Decision Support Tool in Travelling Salesman Problem (TSP) for helping the researchers who doing research in same area will get the better result from the proposed algorithm. A study has been conducted and Rapid Application Development (RAD) model has been use as a methodology which includes requirement planning, user design, construction and cutover. Water Flow Algorithm (WFA) with initialization technique improvement is used as the proposed algorithm in this study for evaluating effectiveness against TSP cases. For DST evaluation will go through usability testing conducted on system use, quality of information, quality of interface and overall satisfaction. Evaluation is needed for determine whether this tool can assists user in making a decision to solve TSP problems with the proposed algorithm or not. Some statistical result shown the ability of this tool in term of helping researchers to conduct the experiments on the WFA with improvements TSP initialization.

  5. FEWA: a Finite Element model of Water flow through Aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, G.T.; Huff, D.D.

    1983-11-01

    This report documents the implementation and demonstration of a Finite Element model of Water flow through Aquifers (FEWA). The particular features of FEWA are its versatility and flexibility to deal with as many real-world problems as possible. Point as well as distributed sources/sinks are included to represent recharges/pumpings and rainfall infiltrations. All sources/sinks can be transient or steady state. Prescribed hydraulic head on the Dirichlet boundaries and fluxes on Neumann or Cauchy boundaries can be time-dependent or constant. Source/sink strength over each element and node, hydraulic head at each Dirichlet boundary node, and flux at each boundary segment can vary independently of each other. Either completely confined or completely unconfined aquifers, or partially confined and partially unconfined aquifers can be dealt with effectively. Discretization of a compound region with very irregular curved boundaries is made easy by including both quadrilateral and triangular elements in the formulation. Large-field problems can be solved efficiently by including a pointwise iterative solution strategy as an optional alternative to the direct elimination solution method for the matrix equation approximating the partial differential equation of groundwater flow. FEWA also includes transient flow through confining leaky aquifers lying above and/or below the aquifer of interest. The model is verified against three simple cases to which analytical solutions are available. It is then demonstrated by two examples of how the model can be applied to heterogeneous and anisotropic aquifers with transient boundary conditions, time-dependent sources/sinks, and confining aquitards for a confined aquifer of variable thickness and for a free surface problem in an unconfined aquifer, respectively. 20 references, 25 figures, 8 tables.

  6. Sap flow index as an indicator of water storage use

    National Research Council Canada - National Science Library

    Nadezhda Nadezhdina; Jan Čermák; Alec Downey; Valeriy Nadezhdin; Martti Perämäki; Jorge Soares David; Clara A. Pinto; Teresa Soares David

    2015-01-01

    Symmetrical temperature difference also known as the sap flow index (SFI) forms the basis of the Heat Field Deformation sap flow measurement and is simultaneously collected whilst measuring the sap flow...

  7. Flow loop studies with AMAX coal-water mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Wildman, D.J.; Ekmann, J.M.

    1984-03-01

    The coal-water mixtures (CWM) with a stabilizer and the CWM without stabilizers were successfully transported through a flow loop facility under a variety of conditions. The handling characteristics of both CWM were reasonable. The mix tank mixer was not needed during nontesting hours to prevent settling of either material. After several days of transporting the nonstabilized material in the loop facility, the viscosity-reducing agent became ineffective. It was necessary to increase the concentration of the viscosity-reducing agent. The material with stabilizer could not be transported through the loop facility at mass flow rates greater than 209 lb/min until overnight shearing of the CWM in the tank. The CWM without a stabilizer appeared to be slightly shear-thickening, whereas the stabilized CWM initially exhibited shear-thinning behavior. The pressure losses measured for the nonstabilized material were similar to the pressure losses measured for CWM prepared at PETC with three or four percent higher concentration of Pittsburgh seam coal. Tests performed with the stabilized CWM experienced pressure losses similar to CWM prepared at PETC with Pittsburgh seam coal of five to seven percent higher concentration. Tests 1A, 2A, 1B, and 2B were not included in the comparison of in-house-prepared CWM due to differences in pretest handling procedures. 1 figure, 2 tables.

  8. Estimates of the impacts of invasive alien plants on water flows in ...

    African Journals Online (AJOL)

    The adverse impacts of alien plant invasions on water flows have been a prime motivation for South Africa's Working for Water Programme. The approach used in this study builds on a previous national assessment in 1998 by incorporating factors that limit plant water-use, information from recent research and improved flow ...

  9. Patterns of a slow air-water flow in a semispherical container

    DEFF Research Database (Denmark)

    Balci, Adnan; Brøns, Morten; Herrada, Miguel A.

    2016-01-01

    This numerical study analyzes the development of eddies in a slow steady axisymmetric air-water flow in a sealed semispherical container, driven by a rotating top disk. As the water height, Hw, increases, new flow cells emerge in both water and air. First, an eddy emerges near the axis-bottom int...

  10. How Green Water Flows structure be a decision indicator for ecological water allocation in arid Ejina Delta, China.

    Science.gov (United States)

    Yu, J.; Du, C.; Zhang, Y.; Liu, X.

    2014-12-01

    Green water flows, a key ecohydrological process, dominates the hydrological cycle in arid region. The structure of green water flows reflects the landscape water consumption characteristics and can be easily obtained by means of remote sensing approach. In arid region, limited fresh water and fragile environment resulted in sharp contradictions between economy and natural ecosystem concerning water demands. To rationally allocate economic and ecological water use, to maximize the regional freshwater use efficiency, is the route one must take for sustainable development in arid area. The pursuit of the most necessary ecological protection function and the maximum ecological water use efficiency is the key to ecological water allocation. However, we are short of simple and quick detectable variables or indexes to assess ecological water allocation decision. This paper introduced the green water flows structure as a decision variable, chose Heihe river flow allocation to downstream Ejina Delta for ecological protection as an example, put forward why and how green water flows structure could be used for ecological water allocation decision. The authors expect to provide reference for integrated fresh water resources management practice in arid region.

  11. The Landlab OverlandFlow component: a Python library for computing shallow-water flow across watersheds

    OpenAIRE

    Adams, Jordan M.; Gasparini, Nicole M.; Hobley, Daniel E. J.; Tucker, Gregory E.; Hutton, Eric W. H.; Nudurupati, Sai S.; Istanbulluoglu, Erkan

    2016-01-01

    Hydrologic models and modeling components are used in a wide range of applications. Rainfall-runoff models are used to investigate the evolution of hydrologic variables, such as soil moisture and surface water discharge, throughout one or more rainfall events. Longer-term landscape evolution models also include aspects of hydrology, albeit in a highly simplified manner, in order to approximate how flowing water shapes landscapes. Here we illustrate how the OverlandFlow hydrologic component co...

  12. Africa-wide monitoring of small surface water bodies using multisource satellite data: a monitoring system for FEWS NET: chapter 5

    Science.gov (United States)

    Velpuri, Naga Manohar; Senay, Gabriel B.; Rowland, James; Verdin, James P.; Alemu, Henok; Melesse, Assefa M.; Abtew, Wossenu; Setegn, Shimelis G.

    2014-01-01

    Continental Africa has the highest volume of water stored in wetlands, large lakes, reservoirs, and rivers, yet it suffers from problems such as water availability and access. With climate change intensifying the hydrologic cycle and altering the distribution and frequency of rainfall, the problem of water availability and access will increase further. Famine Early Warning Systems Network (FEWS NET) funded by the United States Agency for International Development (USAID) has initiated a large-scale project to monitor small to medium surface water points in Africa. Under this project, multisource satellite data and hydrologic modeling techniques are integrated to monitor several hundreds of small to medium surface water points in Africa. This approach has been already tested to operationally monitor 41 water points in East Africa. The validation of modeled scaled depths with field-installed gauge data demonstrated the ability of the model to capture both the spatial patterns and seasonal variations. Modeled scaled estimates captured up to 60 % of the observed gauge variability with a mean root-mean-square error (RMSE) of 22 %. The data on relative water level, precipitation, and evapotranspiration (ETo) for water points in East and West Africa were modeled since 1998 and current information is being made available in near-real time. This chapter presents the approach, results from the East African study, and the first phase of expansion activities in the West Africa region. The water point monitoring network will be further expanded to cover much of sub-Saharan Africa. The goal of this study is to provide timely information on the water availability that would support already established FEWS NET activities in Africa. This chapter also presents the potential improvements in modeling approach to be implemented during future expansion in Africa.

  13. Evaluation of flow regime of turbidity currents entering Dez Reservoir using extended shallow water model

    OpenAIRE

    Valery Ivanovich ELFIMOV; Hamid KHAKZAD

    2014-01-01

    In this study, the performance of the extended shallow water model (ESWM) in evaluation of the flow regime of turbidity currents entering the Dez Reservoir was investigated. The continuity equations for fluid and particles and the Navier-Stokes equations govern the entire flow of turbidity currents. The shallow water equations governing the flow of the depositing phase of turbidity currents are derived from these equations. A case study was conducted on the flow regime of turbidity currents e...

  14. Visualization study of the stream line and secondary flow in the running-water bathtub

    Science.gov (United States)

    Kamei, Shuya; Isshiki, Seita; Takahashi, Akira

    2003-07-01

    By the injecting nozzles' position of the pressurized head tank attached to the water bathtub, water jet flow can be injected to the rectangular water bathtub or diffuser shape water bathtub. The fluid velocity can be set to two kinds of speeds in these bathtubs. The purpose of present study is to visualize flow pattern inside water bathtub. The water bathtub having uniform water flow can be utilized as a very small pool in which everybody can enjoy swimming or can practice physical exercise for health. The utility values for water bathtub can be found in many fields. In this study, we use small transparent rectangular water bathtub made of acrylic resin and materials for the observation of flow pattern inside in it. The method how to make uniform flow inside water bathtub is by injecting water from many jet nozzles attached to the pressurized water tank situated in the front side of water bathtub. Then the downstream water is rejected from overflow bank attached to the rear side of water bathtub. The experiment to visualize flow inside bathtubs is carried out by using liquid and powder as tracers. Much technical knowledge is obtained by the present study.

  15. Water temperature in irrigation return flow from the Upper Snake Rock watershed

    Science.gov (United States)

    Water returning to a river from an irrigated watershed could increase the water temperature in the river. The objective of this study was to compare the temperature of irrigation return flow water with the temperature of the diverted irrigation water. Water temperature was measured weekly in the mai...

  16. Visualization of water flow during filtration using flat filtration materials

    Directory of Open Access Journals (Sweden)

    Hrůza Jakub

    2012-04-01

    Full Text Available Filtration materials are very important elements of some industrial appliances. Water filtration is a separation of solid materials from fluid. Solid particles are captured on the frontal area of the filtration textile and only liquid passes through it. It is important to know the filtration process in a detailed way to be able to develop filtration materials. Visualization of filtration process enables a better view of the filtration. This method also enables to determine efficiency and homogeneity of filtration using image analysis. For this purpose, a new waterfiltration measuring setup was proposed and constructed. Filtration material is mounted into the optically transparent place in the setup. Laser sheet is directed into this place as in the case of Particle Image Velocimetry measuring method. Monochrome and sensitive camera records the light scattered by seeding particles in water. The seeding particles passing through the filter serve for measuring filtration efficiency, and also for visualization of filtration process. Filtration setup enables to measure also the pressure drop and a flow. The signals are processed by National Instruments compactDAQ system and UMA software. Microfibrous and nanofibrous filtration materials are tested by this measuring method. In the case of nanofibrous filtration, appropriate size of seeding particles is needed to be used to perform a process of filtration.

  17. Visualization of water flow during filtration using flat filtration materials

    Science.gov (United States)

    Bílek, Petr; Šidlof, Petr; Hrůza, Jakub

    2012-04-01

    Filtration materials are very important elements of some industrial appliances. Water filtration is a separation of solid materials from fluid. Solid particles are captured on the frontal area of the filtration textile and only liquid passes through it. It is important to know the filtration process in a detailed way to be able to develop filtration materials. Visualization of filtration process enables a better view of the filtration. This method also enables to determine efficiency and homogeneity of filtration using image analysis. For this purpose, a new waterfiltration measuring setup was proposed and constructed. Filtration material is mounted into the optically transparent place in the setup. Laser sheet is directed into this place as in the case of Particle Image Velocimetry measuring method. Monochrome and sensitive camera records the light scattered by seeding particles in water. The seeding particles passing through the filter serve for measuring filtration efficiency, and also for visualization of filtration process. Filtration setup enables to measure also the pressure drop and a flow. The signals are processed by National Instruments compactDAQ system and UMA software. Microfibrous and nanofibrous filtration materials are tested by this measuring method. In the case of nanofibrous filtration, appropriate size of seeding particles is needed to be used to perform a process of filtration.

  18. RESTful NET

    CERN Document Server

    Flanders, Jon

    2008-01-01

    RESTful .NET is the first book that teaches Windows developers to build RESTful web services using the latest Microsoft tools. Written by Windows Communication Foundation (WFC) expert Jon Flanders, this hands-on tutorial demonstrates how you can use WCF and other components of the .NET 3.5 Framework to build, deploy and use REST-based web services in a variety of application scenarios. RESTful architecture offers a simpler approach to building web services than SOAP, SOA, and the cumbersome WS- stack. And WCF has proven to be a flexible technology for building distributed systems not necessa

  19. Simulation of the Regional Ground-Water-Flow System and Ground-Water/Surface-Water Interaction in the Rock River Basin, Wisconsin

    Science.gov (United States)

    Juckem, Paul F.

    2009-01-01

    A regional, two-dimensional, areal ground-water-flow model was developed to simulate the ground-water-flow system and ground-water/surface-water interaction in the Rock River Basin. The model was developed by the U.S. Geological Survey (USGS), in cooperation with the Rock River Coalition. The objectives of the regional model were to improve understanding of the ground-water-flow system and to develop a tool suitable for evaluating the effects of potential regional water-management programs. The computer code GFLOW was used because of the ease with which the model can simulate ground-water/surface-water interactions, provide a framework for simulating regional ground-water-flow systems, and be refined in a stepwise fashion to incorporate new data and simulate ground-water-flow patterns at multiple scales. The ground-water-flow model described in this report simulates the major hydrogeologic features of the modeled area, including bedrock and surficial aquifers, ground-water/surface-water interactions, and ground-water withdrawals from high-capacity wells. The steady-state model treats the ground-water-flow system as a single layer with hydraulic conductivity and base elevation zones that reflect the distribution of lithologic groups above the Precambrian bedrock and a regionally significant confining unit, the Maquoketa Formation. In the eastern part of the Basin where the shale-rich Maquoketa Formation is present, deep ground-water flow in the sandstone aquifer below the Maquoketa Formation was not simulated directly, but flow into this aquifer was incorporated into the GFLOW model from previous work in southeastern Wisconsin. Recharge was constrained primarily by stream base-flow estimates and was applied uniformly within zones guided by regional infiltration estimates for soils. The model includes average ground-water withdrawals from 1997 to 2006 for municipal wells and from 1997 to 2005 for high-capacity irrigation, industrial, and commercial wells. In addition

  20. A study on high-viscosity oil-water two-phase flow in horizontal pipes

    OpenAIRE

    Shi, Jing

    2015-01-01

    A study on high-viscosity oil-water flow in horizontal pipes has been conducted applying experimental, mechanism analysis and empirical modelling, and CFD simulation approaches. A horizontal 1 inch flow loop was modified by adding a designed sampling section to achieve water holdup measurement. Experiments on high-viscosity oil-water flow were conducted. Apart from the data obtained in the present experiments, raw data from previous experiments conducted in the same resea...

  1. Does water content or flow rate control colloid transport in unsaturated porous media?

    Science.gov (United States)

    Knappenberger, Thorsten; Flury, Markus; Mattson, Earl D; Harsh, James B

    2014-04-01

    Mobile colloids can play an important role in contaminant transport in soils: many contaminants exist in colloidal form, and colloids can facilitate transport of otherwise immobile contaminants. In unsaturated soils, colloid transport is, among other factors, affected by water content and flow rate. Our objective was to determine whether water content or flow rate is more important for colloid transport. We passed negatively charged polystyrene colloids (220 nm diameter) through unsaturated sand-filled columns under steady-state flow at different water contents (effective water saturations Se ranging from 0.1 to 1.0, with Se = (θ - θr)/(θs - θr)) and flow rates (pore water velocities v of 5 and 10 cm/min). Water content was the dominant factor in our experiments. Colloid transport decreased with decreasing water content, and below a critical water content (Se colloid transport was inhibited, and colloids were strained in water films. Pendular ring and water film thickness calculations indicated that colloids can move only when pendular rings are interconnected. The flow rate affected retention of colloids in the secondary energy minimum, with less colloids being trapped when the flow rate increased. These results confirm the importance of both water content and flow rate for colloid transport in unsaturated porous media and highlight the dominant role of water content.

  2. Low-flow-storage solar system for domestic hot water; Low-flow Speicherkonzept fuer die solare Trinkwassererwaermung

    Energy Technology Data Exchange (ETDEWEB)

    Leibfried, U. [CONSOLAR Energiespeicher- und Regelungssysteme GmbH, Frankfurt am Main (Germany)

    2004-09-01

    Solar domestic hot water treatment relies on effective and insulated reservoirs to maximize solar efficiency. The article describes a newly developed low flow stratification tank. Key feature of this system is the spiral flow of the coolant in countermovement to the drinking water being heated. (orig.) [German] Bei der Solaren Trinkwassererwaermung ist der Einsatz effektiver Speichersysteme notwendig, um den solaren Ertrag zu maximieren. Im Bericht wird ein low-flow Speicherkonzept vorgestellt. Bei diesem System stroemt der vom Solarkollektor kommende Waermetraeger spiralfoermig von oben nach unten im Gegenstrom zu sich erwaermenden Trinkwasser. (orig.)

  3. Petri Nets

    Indian Academy of Sciences (India)

    Associate Professor of. Computer Science and. Automation at the Indian. Institute of Science,. Bangalore. His research interests are broadly in the areas of stochastic modeling and scheduling methodologies for future factories; and object oriented modeling. GENERAL I ARTICLE. Petri Nets. 1. Overview and Foundations.

  4. Petri Nets

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 8. Petri Nets - Overview and Foundations. Y Narahari. General Article Volume 4 Issue 8 August 1999 pp ... Author Affiliations. Y Narahari1. Department ot Computer Science and Automation, Indian Institute of Science, Bangalore 560 012, India.

  5. Development of neutron measurement techniques in reactor diagnostics and determination of water content and water flow

    Energy Technology Data Exchange (ETDEWEB)

    Avdic, Senada

    2000-09-01

    The present thesis deals with three comparatively different topics in neutron physics research. These topics are as follows: construction and experimental investigation of a new detector, capable of measuring the neutron current, and investigation of the possibility to use it for the localisation of a neutron source in a simple experimental arrangement; execution of neutron transmission measurements based on a stationary neutron generator, and the study of their suitability for determining the volume porosity of geological samples; study of the possibility for improving the accuracy of water flow measurements based on the pulsed neutron activation technique. The first subject of this thesis concerns the measurement of the neutron current by a newly constructed detector. The motivation for this work stems from a recent suggestion that the performance of core monitoring methods could be enhanced if, in addition to the scalar neutron flux, also the neutron current was measured. To this end, a current detector was based on a scintillator mounted on a fibre and a Cd layer on one side of the detector. The measurements of the 2-D neutron current were performed in an experimental system by using this detector. The efficiency of the detector in reactor diagnostics was illustrated by demonstrating that the position of a neutron source can be determined by measuring the scalar neutron flux and the neutron current in one spatial point. The results of measurement and calculation show both the suitability of the detector construction for the measurement of the neutron current vector and the use of the current in diagnostics and monitoring. The second subject of this thesis concerns fast neutron transmission measurements, based on a stationary neutron generator, for determining the volume porosity of a sample in a model experiment. Such a technique could be used in field measurements with obvious advantages in comparison with thermal neutron transmission techniques, which can

  6. Initial hydraulic heads for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the hydraulic-head values in 16 model layers used to initiate the transient simulation of the Death Valley regional ground-water flow...

  7. Lateral boundary of the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the lateral boundary and model domain of the area simulated by the transient ground-water flow model of the Death Valley regional...

  8. Passive sampling of perfluorinated chemicals in water: Flow rate effects on chemical uptake

    NARCIS (Netherlands)

    Kaserzon, S.L.; Vermeirssen, E.L.M.; Hawker, D.W.; Kennedy, K.; Bentley, C.; Thompson, J.; Booij, K.; Mueller, J.F.

    2013-01-01

    A recently developed modified polar organic chemical integrative sampler (POCIS) provides a means for monitoring perfluorinated chemicals (PFCs) in water. However, changes in external flow rates may alter POCIS sampling behaviour and consequently affect estimated water concentrations of analytes. In

  9. Water Withdrawals, Use, and Wastewater Return Flows in the Concord River Basin, Eastern Massachusetts, 1996-2000

    Science.gov (United States)

    Barlow, Lora K.; Hutchins, Linda M.; DeSimone, Leslie A.

    2009-01-01

    total water use in the basin. Wastewater return flows discharged in the basin were estimated at 11,800 Mgal/yr, of which 6,620 Mgal/yr were discharged from municipal wastewater-treatment facilities to surface waters and 5,190 Mgal/yr were self-disposed through septic systems to ground water; wastewater disposed through septic systems was generated by both public- and self-supply use. Water use and management in the Concord River Basin resulted in an estimated import of 6,460 Mgal/yr of potable water for public supply and an estimated export of 6,590 Mgal/yr of wastewater. Water was imported into the Assabet, Sudbury, and Lower Concord (the area draining directly to the Concord River) River Basins for public supply. Wastewater was imported into the Assabet River Basin, but exported from the Sudbury and Lower Concord River Basins. Of the 25 subbasins in the Concord River Basin for which water use was analyzed, 20 subbasins imported potable water, 4 subbasins exported potable water (Fort Meadow Brook, Indian Brook, Lower Sudbury River, and Whitehall Brook), and potable water was neither imported nor exported in one subbasin (Elizabeth Brook). Wastewater was imported into the Assabet Headwaters, Assabet Main Stem, and Hop Brook subbasins; wastewater was neither imported to nor exported from the Elizabeth Brook, Nashoba Brook, and Pine Brook subbasins; and wastewater was exported from all other subbasins. Water use and management in the basin also resulted in a net transfer of water from ground water to surface water, discharged as wastewater, of about 4,000 Mgal/yr.

  10. Stability of Water Lubricated Flow of Yield Stress Fluid in Sloping Pipe

    OpenAIRE

    Decruppe J.; Nsom B.; Ahmad A

    2010-01-01

    To facilitate the transport of viscous crudes in a pipe, an immiscible lubricating liquid, usually water, is added. In such configuration, the water migrates into the regions of high shear at the pipe wall where it lubricates the flow. The pumping pressures being balanced by wall shear stresses in the water, the flow therefore requires pressures comparable to pumping water alone, at the same total throughput [1]. So significant savings in pumping power can be derived from this process p...

  11. Coupled eco-hydrology and biogeochemistry algorithms enable the simulation of water table depth effects on boreal peatland net CO2 exchange

    Science.gov (United States)

    Mezbahuddin, Mohammad; Grant, Robert F.; Flanagan, Lawrence B.

    2017-12-01

    Water table depth (WTD) effects on net ecosystem CO2 exchange of boreal peatlands are largely mediated by hydrological effects on peat biogeochemistry and the ecophysiology of peatland vegetation. The lack of representation of these effects in carbon models currently limits our predictive capacity for changes in boreal peatland carbon deposits under potential future drier and warmer climates. We examined whether a process-level coupling of a prognostic WTD with (1) oxygen transport, which controls energy yields from microbial and root oxidation-reduction reactions, and (2) vascular and nonvascular plant water relations could explain mechanisms that control variations in net CO2 exchange of a boreal fen under contrasting WTD conditions, i.e., shallow vs. deep WTD. Such coupling of eco-hydrology and biogeochemistry algorithms in a process-based ecosystem model, ecosys, was tested against net ecosystem CO2 exchange measurements in a western Canadian boreal fen peatland over a period of drier-weather-driven gradual WTD drawdown. A May-October WTD drawdown of ˜ 0.25 m from 2004 to 2009 hastened oxygen transport to microbial and root surfaces, enabling greater microbial and root energy yields and peat and litter decomposition, which raised modeled ecosystem respiration (Re) by 0.26 µmol CO2 m-2 s-1 per 0.1 m of WTD drawdown. It also augmented nutrient mineralization, and hence root nutrient availability and uptake, which resulted in improved leaf nutrient (nitrogen) status that facilitated carboxylation and raised modeled vascular gross primary productivity (GPP) and plant growth. The increase in modeled vascular GPP exceeded declines in modeled nonvascular (moss) GPP due to greater shading from increased vascular plant growth and moss drying from near-surface peat desiccation, thereby causing a net increase in modeled growing season GPP by 0.39 µmol CO2 m-2 s-1 per 0.1 m of WTD drawdown. Similar increases in GPP and Re caused no significant WTD effects on modeled

  12. Coupled eco-hydrology and biogeochemistry algorithms enable the simulation of water table depth effects on boreal peatland net CO2 exchange

    Directory of Open Access Journals (Sweden)

    M. Mezbahuddin

    2017-12-01

    Full Text Available Water table depth (WTD effects on net ecosystem CO2 exchange of boreal peatlands are largely mediated by hydrological effects on peat biogeochemistry and the ecophysiology of peatland vegetation. The lack of representation of these effects in carbon models currently limits our predictive capacity for changes in boreal peatland carbon deposits under potential future drier and warmer climates. We examined whether a process-level coupling of a prognostic WTD with (1 oxygen transport, which controls energy yields from microbial and root oxidation–reduction reactions, and (2 vascular and nonvascular plant water relations could explain mechanisms that control variations in net CO2 exchange of a boreal fen under contrasting WTD conditions, i.e., shallow vs. deep WTD. Such coupling of eco-hydrology and biogeochemistry algorithms in a process-based ecosystem model, ecosys, was tested against net ecosystem CO2 exchange measurements in a western Canadian boreal fen peatland over a period of drier-weather-driven gradual WTD drawdown. A May–October WTD drawdown of  ∼  0.25 m from 2004 to 2009 hastened oxygen transport to microbial and root surfaces, enabling greater microbial and root energy yields and peat and litter decomposition, which raised modeled ecosystem respiration (Re by 0.26 µmol CO2 m−2 s−1 per 0.1 m of WTD drawdown. It also augmented nutrient mineralization, and hence root nutrient availability and uptake, which resulted in improved leaf nutrient (nitrogen status that facilitated carboxylation and raised modeled vascular gross primary productivity (GPP and plant growth. The increase in modeled vascular GPP exceeded declines in modeled nonvascular (moss GPP due to greater shading from increased vascular plant growth and moss drying from near-surface peat desiccation, thereby causing a net increase in modeled growing season GPP by 0.39 µmol CO2 m−2 s−1 per 0.1 m of WTD drawdown. Similar increases in

  13. Groundwater flow and water budget in the surficial and Floridan aquifer systems in east-central Florida

    Science.gov (United States)

    Sepulveda, Nicasio; Tiedeman, Claire R.; O'Reilly, Andrew M.; Davis, Jeffrey B.; Burger, Patrick

    2012-01-01

    per liter in the Floridan aquifer system. Potential flow across the interface represented by this chloride concentration is simulated by the General Head Boundary Package. During 1995 through 2006, there were no major groundwater withdrawals near the freshwater and saline-water interface, making the general head boundary a suitable feature to estimate flow through the interface. The east-central Florida transient model was calibrated using the inverse parameter estimation code, PEST. Steady-state models for 1999 and 2003 were developed to estimate hydraulic conductivity (K) using average annual heads and spring flows as observations. The spatial variation of K was represented using zones of constant values in some layers, and pilot points in other layers. Estimated K values were within one order of magnitude of aquifer performance test data. A simulation of the final two years (2005-2006) of the 12-year model, with the K estimates from the steady-state calibration, was used to guide the estimation of specific yield and specific storage values. The final model yielded head and spring-flow residuals that met the calibration criteria for the 12-year transient simulation. The overall mean residual for heads, defining residual as simulated minus measured value, was -0.04 foot. The overall root-mean square residual for heads was less than 3.6 feet for each year in the 1995 to 2006 simulation period. The overall mean residual for spring flows was -0.3 cubic foot per second. The spatial distribution of head residuals was generally random, with some minor indications of bias. Simulated average ET over the 1995 to 2006 period was 34.47 inches per year, compared to the calculated average ET rate of 36.39 inches per year from the model-independent water-budget analysis. Simulated average net recharge to the surficial aquifer system was 3.58 inches per year, compared with the calculated average of 3.39 inches per year from the model-independent water-budget analysis. Groundwater

  14. within plant resistance to water flow in tomato and sweet melons ...

    African Journals Online (AJOL)

    Administrator

    In the evaporative flux method, measure- ments of transpiration flux and leaf water potential were used to calculate the total resistance to water flow using .... Plant resistance is modulated by changes in the status of water conducting system, ... The understanding of plant water relations in crop species have implications for ...

  15. Estimating drain flow from measured water table depth in layered soils under free and controlled drainage

    Science.gov (United States)

    Saadat, Samaneh; Bowling, Laura; Frankenberger, Jane; Kladivko, Eileen

    2018-01-01

    Long records of continuous drain flow are important for quantifying annual and seasonal changes in the subsurface drainage flow from drained agricultural land. Missing data due to equipment malfunction and other challenges have limited conclusions that can be made about annual flow and thus nutrient loads from field studies, including assessments of the effect of controlled drainage. Water table depth data may be available during gaps in flow data, providing a basis for filling missing drain flow data; therefore, the overall goal of this study was to examine the potential to estimate drain flow using water table observations. The objectives were to evaluate how the shape of the relationship between drain flow and water table height above drain varies depending on the soil hydraulic conductivity profile, to quantify how well the Hooghoudt equation represented the water table-drain flow relationship in five years of measured data at the Davis Purdue Agricultural Center (DPAC), and to determine the impact of controlled drainage on drain flow using the filled dataset. The shape of the drain flow-water table height relationship was found to depend on the selected hydraulic conductivity profile. Estimated drain flow using the Hooghoudt equation with measured water table height for both free draining and controlled periods compared well to observed flow with Nash-Sutcliffe Efficiency values above 0.7 and 0.8 for calibration and validation periods, respectively. Using this method, together with linear regression for the remaining gaps, a long-term drain flow record for a controlled drainage experiment at the DPAC was used to evaluate the impacts of controlled drainage on drain flow. In the controlled drainage sites, annual flow was 14-49% lower than free drainage.

  16. Flow patterns and pressure drop in air/water two-phase flow in horizontal helicoidal pipes

    Energy Technology Data Exchange (ETDEWEB)

    Awwad, A.; Xin, R.C.; Dong, Z.F.; Ebadian, M.A. [Florida International Univ., Miami, FL (United States). Dept. of Mechanical Engineering; Soliman, H.M. [Univ. of Manitoba, Winnipeg, Manitoba (Canada). Dept. of Mechanical Engineering

    1995-12-01

    An experimental investigation is conducted for air/water two-phase flow in horizontal helicoidal pipes. The helicoidal pipes are constructed of 25.4 mm I.D. Tygon tubing wrapped around cylindrical concrete forms with outside diameters of 62 cm and 124 cm. The helix angles of the helicoidal pipes vary from 1 to 20 deg. The experiments are performed for superficial water velocity in a range of U{sub L} = 0.008 {approximately} 2.2 m/s and for superficial air velocity in a range of U{sub G} = 0.2 {approximately} 50 m/s. The flow patterns are discerned and recorded photographically. The pressure drop of the air/water two-phase flow in the coils is measured and the Lockhart-Martinelli approach is used to analyze the data. The results are presented in the form of frictional pressure drop multipliers versus the Lockhart-Martinelli parameter. It was found that the flow patterns differ greatly from those of the straight pipe, and that the frictional pressure drop multipliers depend on both the Lockhart-Martinelli parameter and the flow rates. The correlation of the frictional pressure drop has been provided based on the current data. Furthermore, it was also found that the helix angle of the helicoidal pipe had almost no effect on the air/water two-phase flow pressure drop in the present experimental ranges.

  17. Source Water Flow Pathways In Forested, Mountain, Headwater Streams: A Link Between Sediment Movement Patterns And Stream Water Chemistry.

    Science.gov (United States)

    Martin, S.; Conklin, M. H.; Liu, F.

    2015-12-01

    Three years of continuous and discrete sediment and water quality data, from four forested, mountain, headwater catchments in the Sierra Nevada, is used to identify water sources, determine the importance of sub-surface flow pathways, detect any changes in source waters due to seasonal variation or drought, and link flow pathways with observed patterns of in-channel sediment movement within the study watersheds. Patterns in stream chemistry and turbidity point to infiltration as the dominant flow pathway within these catchments. Data support a flow pathway conceptual model in which precipitation water infiltrates into the shallow or deeper subsurface, increasing the hydraulic head of the water table and pushing pre-event water into the stream ahead of event water. Study catchments contain perennial streams and are characterized by a Mediterranean climate with a distinct wet and dry season. Sites are located in the rain-snow transition zone with snow making up 40 to 60 percent of average annual precipitation. Barring human disturbances such as logging/grazing (compaction) or fire (hydrophobicity), catchment soils have high infiltration capacities. Springs and seeps maintain baseflow during the summer low-flow season, and shifting chemical signals within the streams indicate the increased importance of sub-surface water sources during drought years. End-member mixing analysis was conducted to identify possible water end members. Turbidity hysteresis patterns described by previous studies show in-channel sources are dominant for discharge events year round, and there is no difference in fine sediment delivery to streams with or without a soil protecting layer of snow on the land surface. The dominance of sub-surface water sources and evidence for infiltration flow fits with turbidity data, as little material is reaching the stream due to erosive overland flow. An understanding of flow pathways provides a foundation for sustainable land use management in forested

  18. Basal interstitial water pressure in laboratory debris flows over a rigid bed in an open channel

    Directory of Open Access Journals (Sweden)

    N. Hotta

    2012-08-01

    Full Text Available Measuring the interstitial water pressure of debris flows under various conditions gives essential information on the flow stress structure. This study measured the basal interstitial water pressure during debris flow routing experiments in a laboratory flume. Because a sensitive pressure gauge is required to measure the interstitial water pressure in shallow laboratory debris flows, a differential gas pressure gauge with an attached diaphragm was used. Although this system required calibration before and after each experiment, it showed a linear behavior and a sufficiently high temporal resolution for measuring the interstitial water pressure of debris flows. The values of the interstitial water pressure were low. However, an excess of pressure beyond the hydrostatic pressure was observed with increasing sediment particle size. The measured excess pressure corresponded to the theoretical excess interstitial water pressure, derived as a Reynolds stress in the interstitial water of boulder debris flows. Turbulence was thought to induce a strong shear in the interstitial space of sediment particles. The interstitial water pressure in boulder debris flows should be affected by the fine sediment concentration and the phase transition from laminar to turbulent debris flow; this should be the subject of future studies.

  19. Bifurcations of a creeping air–water flow in a conical container

    DEFF Research Database (Denmark)

    Balci, Adnan; Brøns, Morten; Herrada, Miguel A.

    2016-01-01

    This numerical study describes the eddy emergence and transformations in a slow steady axisymmetric air–water flow, driven by a rotating top disk in a vertical conical container. As water height (Formula presented.) and cone half-angle (Formula presented.) vary, numerous flow metamorphoses occur....

  20. Dynamics of transpiration, sap flow and use of stored water in tropical forest canopy trees.

    Science.gov (United States)

    Frederick C. Meinzer; Shelley A. James; Guillermo. Goldstein

    2004-01-01

    In large trees the daily onset of transpiration causes water to be withdrawn from internal storage compartments resulting in lags between changes in transpiration and sap flow at the base of the tree. We measured time courses of sap flow, hydraulic resistance, plant water potential and stomatal resistance in co-occuring tropical forest canopy trees with trunk diameters...

  1. Impacts of impervious cover, water withdrawals, and climate change on river flows in the conterminous US

    Science.gov (United States)

    P. V. Caldwell; G. Sun; S. G. McNulty; E. C. Cohen; J. A. Moore Myers

    2012-01-01

    Rivers are essential to aquatic ecosystem and societal sustainability, but are increasingly impacted by water withdrawals, land-use change, and climate change. The relative and cumulative effects of these stressors on continental river flows are relatively unknown. In this study, we used an integrated water balance and flow routing model to evaluate the impacts of...

  2. Instream flow and water regime of selected riparian habitats in west-central Montana

    Science.gov (United States)

    Stephanie K. Mulica; Donald F. Potts; Robert D. Pfister

    2002-01-01

    Groundwater and surface water extraction and diversion for agricultural and human use has become common practice in the arid and semi-arid western United States. Surface water and groundwater are often not effectively managed during these processes, and few laws exist to protect riparian vegetation in the case of depletion of in-stream flows. "Instream flow"...

  3. A Device to Emulate Diffusion and Thermal Conductivity Using Water Flow

    Science.gov (United States)

    Blanck, Harvey F.

    2005-01-01

    A device designed to emulate diffusion and thermal conductivity using flowing water is reviewed. Water flowing through a series of cells connected by a small tube in each partition in this plastic model is capable of emulating diffusion and thermal conductivity that occurs in variety of systems described by several mathematical equations.

  4. CFD model of multiphase flow in the abrasive water jet tool

    OpenAIRE

    Říha, Zdeněk

    2015-01-01

    The possibility of using CFD fluid flow modeling in area of tools with abrasive water jet is described in the paper. The correct function of such tool is based on proper setting of multiphase flow of water, air and solid particles in the inner space of the tool. The multiphase fluid flow numerical simulation can provide information which show relation between the geometry and the flow field. Then, this stable CFD model of multiphase flow creates key to design of the tool able to work wi...

  5. Methylmercury and other chemical constituents in Pacific coastal fog water from seven sites in Central/Northern California (FogNet) during the summer of 2014

    Science.gov (United States)

    Weiss-Penzias, P. S.; Heim, W. A.; Fernandez, D.; Coale, K. H.; Oliphant, A. J.; Dann, D.; Porter, M.; Hoskins, D.; Dodge, C.

    2014-12-01

    This project investigates the mercury content in summertime Pacific coastal fog in California and whether fog could be an important vector for ocean emissions of mercury to be deposited via fog drip to upland coastal ecosystems. Efforts began in early 2014 with the building of 7 active-strand fog collectors based on the Colorado State University Caltech CASCC design. The new UCSC CASCC includes doors sealing the collector which open under microcomputer control based on environmental sensing (relative humidity). Seven sites spanning from Trinidad in the north to Marina in the south have collected samples June-August 2014 under a project called FogNet. Fog conditions were favorable for collecting large water volumes (> 250 mL) at many sites. Fog samplers were cleaned with soap and deionized water daily and field blanks taken immediately following cleaning. Fog water samples were collected overnight, split into an aliquot for anion and DOC/DIC analysis and the remaining sample was acidified. Monomethyl mercury (MMHg) concentrations in samples and field blanks for 3 sites in FogNet are shown in the accompanying figure. The range of MMHg concentrations from 10 fog water samples > 100 mL in volume was 0.9-9.3 ng/L (4.5-46.4 pM). Elevated MMHg concentrations (> 5 ng/L, 25 pM) were observed at 2 sites: UC Santa Cruz and Bodega Bay. The field blanks produced MMHg concentrations of 0.08-0.4 ng/L (0.4-2.0 pM), which was on average < 10% of the sample concentration and suggests the artifact due to sampling was small. The observed MMHg concentrations in fog water observed is this study are 1-2 orders of magnitude greater than MMHg concentrations seen previously in rain water samples from the California coast suggesting an additional source of MMHg to fog. Shipboard measurements of dimethyl mercury (DMHg) in coastal California seawater during the time period of FogNet operations (summer 2014) reveal surface waters that were supersaturated in DMHg which represents a potential

  6. A water balance model to estimate flow through the Old and Middle River corridor

    Science.gov (United States)

    Andrews, Stephen W.; Gross, Edward S.; Hutton, Paul H.

    2016-01-01

    We applied a water balance model to predict tidally averaged (subtidal) flows through the Old River and Middle River corridor in the Sacramento–San Joaquin Delta. We reviewed the dynamics that govern subtidal flows and water levels and adopted a simplified representation. In this water balance approach, we estimated ungaged flows as linear functions of known (or specified) flows. We assumed that subtidal storage within the control volume varies because of fortnightly variation in subtidal water level, Delta inflow, and barometric pressure. The water balance model effectively predicts subtidal flows and approaches the accuracy of a 1–D Delta hydrodynamic model. We explore the potential to improve the approach by representing more complex dynamics and identify possible future improvements.

  7. Hardware Development of Ultrasonic Tomography for Composition Determination of Water and Oil Flow

    Directory of Open Access Journals (Sweden)

    Ruzairi Abdul Rahim

    2007-01-01

    Full Text Available A monitoring system for water and oil flow using ultrasonic Tomography is implemented. Information such as the type of flow, the composition of the water and oil can be obtained from the system. The composition of the flow is determined based on the propagation time of the ultrasonic waves. The ultrasonic Tomography system includes the sensors fixture design, signal conditioning circuits and image reconstruction software. The image reconstruction algorithm that used is the Linear Back Projection (LBP algorithm.

  8. A two-step approach to estimating selectivity and fishing power of research gill nets used in Greenland waters

    DEFF Research Database (Denmark)

    Hovgård, Holger

    1996-01-01

    Catches of Atlantic cod (Gadus morhua) from Greenland gill-net surveys were analyzed by a two-step approach. In the initial step the form of the selection curve was identified as binormal, which was caused by fish being gilled or caught by the maxillae. Both capture processes could be described...... by normal distributions and could be related to mesh size in accordance with the principle of geometrical similarity. In the second step the selection parameters were estimated by a nonlinear least squares fit. The model also estimated the relative efficiency of the two capture processes and the fishing...

  9. Water Management for Competing Uses: Environmental Flows in the Transboundary Rio Grande/Rio Bravo

    Science.gov (United States)

    Sandoval Solis, S.; McKinney, D. C.

    2011-12-01

    Introduction Due to high water demand, the scarcity of water, and the complexity of water allocation, environmental flows have not been considered as an integral part of the water management in the Rio Grande/Rio Bravo transboundary basin. The Big Bend reach is located between the cities of Presidio/Ojinaga to Amistad international reservoir, along the main stream (Fig. 1). Important environmental habitats such as the Big Bend National and State Park in the U.S., the Maderas del Carmen, Cañon de Santa Elena and Ocampo natural reserved areas in Mexico are ecologically threatened because of the lack of environmental water management policies. Several efforts have been undertaken by scientists, government agencies and NGOs to determine the environmental flows for this reach and water management policies that can provide these flows. Objective The objective of this research is to describe a water management policy that can conciliate environmental and human water uses in the Big Bend region. In other words, define a policy that can provide environmental flows without harming water supply for stakeholders or increasing flood risk, within legal and physical constraints of the system. Methodology First, the system was characterized identifying water users, hydraulic infrastructure, and water allocation according to state, federal and international regulations. Second, a hydrograph for environmental flows was proposed that mimics the hydrologic characteristics of the prior dam alteration. Third, a water planning model was constructed to evaluate alternative policies. Fourth, the water management is proposed to provide environmental restoration flows from Luis L. Leon reservoir. This policy considers mechanisms that reduce flooding and drought risks, while meting national and international water regulations. Results Three types of natural flow regimes are considered: (1) median flows aimed to provide the base flow in the region, (2) high flows to provide transversal

  10. Diverting the flow : gender equity and water in South Asia

    NARCIS (Netherlands)

    Zwarteveen, M.Z.; Ahmed, S.; Gautam, S.R.

    2012-01-01

    Across the South Asian region, water determines livelihoods and in some cases even survival. However, water also creates exclusions. Access to water, and its social organization, are intimately tied up with power relations. This book provides an overview of gender, equity and water issues relevant

  11. Hydrology and simulation of ground-water flow in the Tooele Valley ground-water basin, Tooele County, Utah

    Science.gov (United States)

    Stolp, Bernard J.; Brooks, Lynette E.

    2009-01-01

    Ground water is the sole source of drinking water within Tooele Valley. Transition from agriculture to residential land and water use necessitates additional understanding of water resources. The ground-water basin is conceptualized as a single interconnected hydrologic system consisting of the consolidated-rock mountains and adjoining unconsolidated basin-fill valleys. Within the basin fill, unconfined conditions exist along the valley margins and confined conditions exist in the central areas of the valleys. Transmissivity of the unconsolidated basin-fill aquifer ranges from 1,000 to 270,000 square feet per day. Within the consolidated rock of the mountains, ground-water flow largely is unconfined, though variability in geologic structure, stratigraphy, and lithology has created some areas where ground-water flow is confined. Hydraulic conductivity of the consolidated rock ranges from 0.003 to 100 feet per day. Ground water within the basin generally moves from the mountains toward the central and northern areas of Tooele Valley. Steep hydraulic gradients exist at Tooele Army Depot and near Erda. The estimated average annual ground-water recharge within the basin is 82,000 acre-feet per year. The primary source of recharge is precipitation in the mountains; other sources of recharge are irrigation water and streams. Recharge from precipitation was determined using the Basin Characterization Model. Estimated average annual ground-water discharge within the basin is 84,000 acre-feet per year. Discharge is to wells, springs, and drains, and by evapotranspiration. Water levels at wells within the basin indicate periods of increased recharge during 1983-84 and 1996-2000. During these periods annual precipitation at Tooele City exceeded the 1971-2000 annual average for consecutive years. The water with the lowest dissolved-solids concentrations exists in the mountain areas where most of the ground-water recharge occurs. The principal dissolved constituents are calcium

  12. Change regularity of water quality parameters in leakage flow conditions and their relationship with iron release.

    Science.gov (United States)

    Liu, Jingqing; Shentu, Huabin; Chen, Huanyu; Ye, Ping; Xu, Bing; Zhang, Yifu; Bastani, Hamid; Peng, Hongxi; Chen, Lei; Zhang, Tuqiao

    2017-11-01

    The long-term stagnation in metal water supply pipes, usually caused by intermittent consumption patterns, will cause significant iron release and water quality deterioration, especially at the terminus of pipelines. Another common phenomenon at the terminus of pipelines is leakage, which is considered helpful by allowing seepage of low-quality drinking water resulting from long-term stagnation. In this study, the effect of laminar flow on alleviating water quality deterioration under different leakage conditions was investigated, and the potential thresholds of the flow rate, which can affect the iron release process, were discussed. Based on a galvanized pipe and ductile cast iron pipe pilot platform, which was established at the terminus of pipelines, this research was carried out by setting a series of leakage rate gradients to analyze the influence of different leakage flow rates on iron release, as well as the relationship with chemical and biological parameters. The results showed that the water quality parameters were obviously influenced by the change in flow velocity. Water quality was gradually improved with an increase in flow velocity, but its change regularity reflected a diversity under different flow rates (p water distribution system, when the bulk water was at the critical laminar flow velocity, the concentration of total iron, the quantity and rate of total iron release remain relatively in an ideal and safe situation. Copyright © 2017. Published by Elsevier Ltd.

  13. KM3NeT

    CERN Multimedia

    KM3NeT is a large scale next-generation neutrino telescope located in the deep waters of the Mediterranean Sea, optimized for the discovery of galactic neutrino sources emitting in the TeV energy region.

  14. eWaterCycle visualisation. combining the strength of NetCDF and Web Map Service: ncWMS

    Science.gov (United States)

    Hut, R.; van Meersbergen, M.; Drost, N.; Van De Giesen, N.

    2016-12-01

    As a result of the eWatercycle global hydrological forecast we have created Cesium-ncWMS, a web application based on ncWMS and Cesium. ncWMS is a server side application capable of reading any NetCDF file written using the Climate and Forecasting (CF) conventions, and making the data available as a Web Map Service(WMS). ncWMS automatically determines available variables in a file, and creates maps colored according to map data and a user selected color scale. Cesium is a Javascript 3D virtual Globe library. It uses WebGL for rendering, which makes it very fast, and it is capable of displaying a wide variety of data types such as vectors, 3D models, and 2D maps. The forecast results are automatically uploaded to our web server running ncWMS. In turn, the web application can be used to change the settings for color maps and displayed data. The server uses the settings provided by the web application, together with the data in NetCDF to provide WMS image tiles, time series data and legend graphics to the Cesium-NcWMS web application. The user can simultaneously zoom in to the very high resolution forecast results anywhere on the world, and get time series data for any point on the globe. The Cesium-ncWMS visualisation combines a global overview with local relevant information in any browser. See the visualisation live at forecast.ewatercycle.org

  15. Flow Simulation of Solid Rocket Motors. 1; Injection Induced Water-Flow Tests from Porous Media

    Science.gov (United States)

    Ramachandran, N.; Yeh, Y. P.; Smith, A. W.; Heaman, J. P.

    1999-01-01

    Prior to selecting a proper porous material for use in simulating the internal port flow of a solid rocket motor (SRM), in cold-flow testing, the flow emerging from porous materials is experimentally investigated. The injection-flow emerging from a porous matrix always exhibits a lumpy velocity profile that is spatially stable and affects the development of the longitudinal port flow. This flow instability, termed pseudoturbulence, is an inherent signature of the porous matrix and is found to generally increase with the wall porosity and with the injection flow rate. Visualization studies further show that the flow from porous walls made from shaving-type material (sintered stainless-steel) exhibits strong recirculation zones that are conspicuously absent in walls made from nodular or spherical material (sintered bronze). Detailed flow visualization observations and hot-film measurements are reported from tests of injection-flow and a coupled cross-flow from different porous wall materials. Based on the experimental data, discussion is provided on the choice of suitable material for SRM model testing while addressing the consequences and shortcomings from such a test.

  16. Hydrogeology of, and Simulation of Ground-Water Flow In, the Pohatcong Valley, Warren County, New Jersey

    Science.gov (United States)

    Carleton, Glen B.; Gordon, Alison D.

    2007-01-01

    A numerical ground-water-flow model was constructed to simulate ground-water flow in the Pohatcong Valley, including the area within the U.S. Environmental Protection Agency Pohatcong Valley Ground Water Contamination Site. The area is underlain by glacial till, alluvial sediments, and weathered and competent carbonate bedrock. The northwestern and southeastern valley boundaries are regional-scale thrust faults and ridges underlain by crystalline rocks. The unconsolidated sediments and weathered bedrock form a minor surficial aquifer and the carbonate rocks form a highly transmissive fractured-rock aquifer. Ground-water flow in the carbonate rocks is primarily downvalley towards the Delaware River, but the water discharges through the surficial aquifer to Pohatcong Creek under typical conditions. The hydraulic characteristics of the carbonate-rock aquifer are highly heterogeneous. Horizontal hydraulic conductivities span nearly five orders of magnitude, from 0.5 feet per day (ft/d) to 1,800 ft/d. The maximum transmissivity calculated is 37,000 feet squared per day. The horizontal hydraulic conductivities calculated from aquifer tests using public supply wells open to the Leithsville Formation and Allentown Dolomite are 34 ft/d (effective hydraulic conductivity) and 85 to 190 ft/d (minimum and maximum hydraulic conductivity, respectively, yielding a horizontal anisotropy ratio of 0.46). Stream base-flow data were used to estimate the net gain (or loss) for selected reaches on Brass Castle Creek, Shabbecong Creek, three smaller tributaries to Pohatcong Creek, and for five reaches on Pohatcong Creek. Estimated mean annual base flows for Brass Castle Creek, Pohatcong Creek at New Village, and Pohatcong Creek at Carpentersville (from correlations of partial- and continuous-record stations) are 2.4, 25, and 45 cubic feet per second (ft3/s) (10, 10, and 11 inches per year (in/yr)), respectively. Ground-water ages estimated using sulfur hexafluoride (SF6

  17. Numerical study of the air-flow in an oscillating water column wave energy converter

    Energy Technology Data Exchange (ETDEWEB)

    Paixao Conde, J.M. [Department of Mechanical and Industrial Engineering, Faculty of Sciences and Technology, New University of Lisbon, Monte de Caparica, 2829-516 Caparica (Portugal); IDMEC, Instituto Superior Tecnico, Technical University of Lisbon, 1049-001 Lisboa (Portugal); Gato, L.M.C. [IDMEC, Instituto Superior Tecnico, Technical University of Lisbon, 1049-001 Lisboa (Portugal)

    2008-12-15

    The paper presents a numerical study of the air-flow in a typical pneumatic chamber geometry of an oscillating water column (OWC)-type wave energy converter (WEC), equipped with two vertical-axis air turbines, asymmetrically placed on the top of the chamber. Outwards and inwards, steady and periodic, air-flow calculations were performed to investigate the flow distribution at the turbines' inlet sections, as well as the properties of the air-jet impinging on the water free-surface. The original design of the OWC chamber is likely to be harmful for the operation of the turbines due to the possible air-jet-produced water-spray at the water free-surface subsequently ingested by the turbine. A geometry modification of the air chamber, using a horizontal baffle-plate to deflect the air from the turbines, is proposed and proved to be very effective in reducing the risk of water-spray production from the inwards flow. The flow distribution at the turbines' inlet sections for the outwards flow was found to be fairly uniform for the geometries considered, providing good inlet flow conditions for the turbines. Steady flow was found to be an acceptable model to study the air-flow inside the pneumatic chamber of an OWC-WEC. (author)

  18. An Investigation into Air-Sand-Water Three-Phase Flow through the Sandblasting Nozzle

    Directory of Open Access Journals (Sweden)

    M. Abbasalizadeh

    2013-09-01

    Full Text Available The numerical analysis of air-sand-water three-phase turbulent flow through converging-diverging nozzle is investigated for employing on sandblasting systems. For this purpose-dispersed flow of air-sand-water by various airs inlet pressures and different mass flow rates of sand particles and water droplets were considered. Two-way turbulence coupling between particles/droplets and airflow as well as interference between the incident streams of particles and rebounded from the wall were applied in the numerical model. In addition, the shock wave, which is produced in supersonic flow at diverging part of nozzle, was considered. In this study the Realizable k-ε and Discrete Phase models were utilized for simulating of multi-phase turbulent flow through the converging-diverging nozzle. As review of literature indicates there is not any experimental or analytical data on three-phase flow through the nozzle, consequently for validation of model, the same turbulent and multi-phase models were utilized on air-water two-phase flow. The obtained results were in good agreement with the experimental data. According to the results of three-phase flow simulation, the averaged exhaust momentum of sand particles had inverse proportion with water mass flow rate, and increasing of air inlet pressure had significant effect on mean exhaust velocity of sand particles.

  19. Influence of cold-water immersion on limb blood flow after resistance exercise.

    Science.gov (United States)

    Mawhinney, Chris; Jones, Helen; Low, David A; Green, Daniel J; Howatson, Glyn; Gregson, Warren

    2017-06-01

    This study determined the influence of cold (8°C) and cool (22°C) water immersion on lower limb and cutaneous blood flow following resistance exercise. Twelve males completed 4 sets of 10-repetition maximum squat exercise and were then immersed, semi-reclined, into 8°C or 22°C water for 10-min, or rested in a seated position (control) in a randomized order on different days. Rectal and thigh skin temperature, muscle temperature, thigh and calf skin blood flow and superficial femoral artery blood flow were measured before and after immersion. Indices of vascular conductance were calculated (flux and blood flow/mean arterial pressure). The colder water reduced thigh skin temperature and deep muscle temperature to the greatest extent (P cold and cool water similarly reduce femoral artery and cutaneous blood flow responses but not muscle temperature following resistance exercise.

  20. High performance in low-flow solar domestic hot water systems

    Energy Technology Data Exchange (ETDEWEB)

    Dayan, M.

    1997-12-31

    Low-flow solar hot water heating systems employ flow rates on the order of 1/5 to 1/10 of the conventional flow. Low-flow systems are of interest because the reduced flow rate allows smaller diameter tubing, which is less costly to install. Further, low-flow systems result in increased tank stratification. Lower collector inlet temperatures are achieved through stratification and the useful energy produced by the collector is increased. The disadvantage of low-flow systems is the collector heat removal factor decreases with decreasing flow rate. Many solar domestic hot water systems require an auxiliary electric source to operate a pump in order to circulate fluid through the solar collector. A photovoltaic driven pump can be used to replace the standard electrical pump. PV driven pumps provide an ideal means of controlling the flow rate, as pumps will only circulate fluid when there is sufficient radiation. Peak performance was always found to occur when the heat exchanger tank-side flow rate was approximately equal to the average load flow rate. For low collector-side flow rates, a small deviation from the optimum flow rate will dramatically effect system performance.

  1. Quantifying water flow and retention in an unsaturated fracture-facial domain

    Science.gov (United States)

    Nimmo, John R.; Malek-Mohammadi, Siamak

    2015-01-01

    Hydrologically significant flow and storage of water occur in macropores and fractures that are only partially filled. To accommodate such processes in flow models, we propose a three-domain framework. Two of the domains correspond to water flow and water storage in a fracture-facial region, in addition to the third domain of matrix water. The fracture-facial region, typically within a fraction of a millimeter of the fracture wall, includes a flowing phase whose fullness is determined by the availability and flux of preferentially flowing water, and a static storage portion whose fullness is determined by the local matric potential. The flow domain can be modeled with the source-responsive preferential flow model, and the roughness-storage domain can be modeled with capillary relations applied on the fracture-facial area. The matrix domain is treated using traditional unsaturated flow theory. We tested the model with application to the hydrology of the Chalk formation in southern England, coherently linking hydrologic information including recharge estimates, streamflow, water table fluctuation, imaging by electron microscopy, and surface roughness. The quantitative consistency of the three-domain matrix-microcavity-film model with this body of diverse data supports the hypothesized distinctions and active mechanisms of the three domains and establishes the usefulness of this framework.

  2. Ground-water flow and quality in Wisconsin's shallow aquifer system

    Science.gov (United States)

    Kammerer, P.A.

    1995-01-01

    The areal concentration distribution of commonmineral constituents and properties of ground water in Wisconsin's shallow aquifer system are described in this report. Maps depicting the water quality and the altitude of the water table are included. The shallow aquifer system in Wisconsin, composed of unconsolidated sand and gravel and shallow bedrock, is the source of most potable ground-water supplies in the State. Most ground water in the shallow aquifer system moves in local flow systems, but it interacts with regional flow systems in some areas.

  3. Stability of Water Lubricated Flow of Yield Stress Fluid in Sloping Pipe

    Directory of Open Access Journals (Sweden)

    Decruppe J.

    2010-06-01

    Full Text Available To facilitate the transport of viscous crudes in a pipe, an immiscible lubricating liquid, usually water, is added. In such configuration, the water migrates into the regions of high shear at the pipe wall where it lubricates the flow. The pumping pressures being balanced by wall shear stresses in the water, the flow therefore requires pressures comparable to pumping water alone, at the same total throughput [1]. So significant savings in pumping power can be derived from this process provided that it is well monitored. Indeed, instabilities usually take place at the oil/water interface and they constitute an important source of energy dissipation. Precisely, a core annular flow is known to undergo a long-wave instability of capillary type, modified by shear occuring at low Reynolds. Above a given critical Reynolds number, the flow is unstable to shorter waves which leads to an emulsification system of water droplets in oil. In present work, an experimental study of the stability of sloping plane Poiseuille flow of well characterized viscoplastic mineral oils lubricated by water was performed. The investigation was carried out by means of image analysis based on spatiotemporal diagrams (STD. Notably indicated are the effects of bed slope, flow rates ratio and oil rheology on flow stability.

  4. Lithospheric Dynamics of Mars: Water, Flow, and Failure

    Science.gov (United States)

    Grimm, Robert E.; Harrison, Keith

    2004-01-01

    Some of the largest Martian erosive features were influenced by groundwater, and include valley networks, outflow channels, and possibly landslides. We argue that hydrothermal systems attending crustal formation processes were able to drive sufficient groundwater to the surface to form the Noachian southern highlands valley networks, which show a spatial correlation to crustal magnetic anomalies, also results of crustal formation. Hydrothermal activity is quantified through numerical simulations of convection in a porous medium due to the presence of a hot intruded magma chamber. The parameter space includes magma chamber depth, volume, aspect ratio, and host rock permeability and porosity. For permeabilities as low as l0(exp -17) sq m and intrusion volumes as low as 50 km , the total discharge due to intrusions building that part of the southern highlands crust associated with magnetic anomalies spans a comparable range as the inferred discharge from the overlying valley networks. The Hesperian circum-Chryse outflow channels are further manifestations of groundwater discharge and Clifford and Parker (2001) suggest that the large volumes of water required for their formation flows beneath a confining cryosphere from the South Pole where meltwater beneath an ice cap recharges a global aquifer. We argue that recharge occurs instead over the nearby Tharsis aquifer at high obliquity, assisted by cryosphere melting due to volcanic activity. Numerical simulations quantify the strength and duration of outflow discharge given either South Polar or Tharsis recharge. The contribution of South Pole recharge given Clifford and Parker aquifer properties is negligible compared to that of the initial Tharsis inventory. Tharsis recharge, despite the restrictions of improved aquifer properties, makes a significant contribution and, unlike South Pole recharge under the same conditions, fulfills discharge requirements. Groundwater may have influenced long run-out landslide formation

  5. An experimental study of on-line measurement of water fraction in gas-oil-water three-phase flow

    Science.gov (United States)

    Chen, K.; Guo, L. J.; Ye, J.

    2012-03-01

    Gas-oil-water two-or three-phase flow is widely encountered in industry, such as petroleum chemical industry, bio-chemicals, food chemicals, and mineral engineering and energy projects. Two kinds of on-line measurement technique, which are double-ring conductance sensor and double-helical capacitance sensor, for water fraction in oil-water two-phase flow and gas-oil-water three-phase flow were developed in this paper. The calibration results shows that the responses of the two sensors are good enough as the variation of water fraction. And on the other hand, it is possible that the oil and the gas regard as one phase in gas-oil-water three-phase flow by using double-helical capacitance sensor, and the ratio between water and gas has no effect with the output signal. The range of water fraction which can be measured becomes bigger and bigger because of the using of new circuit. So the capacitance sensor is better enough to measure water fraction in the three phases flow. During dynamic experiment, because of phase inversion phenomenon between oil and water, the conductance sensor outputs poorly, however the capacitance sensor performs somewhat fine. The reason for the error using capacitance sensor is the edge effect of the capacitance. The experiment results show that the edge effect of the double-helical capacitance sensor causes that the output is smaller so that the measuring water fraction is a litter larger than the actual value. And when the variation of water fraction is above 10%, the edge effect of capacitance sensor can be almost neglected. On the contrary, when the variation of water fraction is below 10%, the edge effect is so lager than the results above that it cannot be ignored. Consequently, the double-helical capacitance probe is more suitable for measuring water fraction in slug flow and oil-water emulsion, in which the results agree better with static calibration than that in bubble flow.

  6. Human well-being values of environmental flows enhancing social equity in integrated water resources management

    NARCIS (Netherlands)

    Meijer, K.S.

    2007-01-01

    This dissertation discusses how the importance of river flow-sustained ecosystems for local communities can be quantified for the purpose of balancing water supply and demand in Integrated Water Resources Management. Due to the development of water resources, for example through the construction of

  7. Influence of soil structure and root water uptake strategy on unsaturated flow in heterogeneous media

    NARCIS (Netherlands)

    Kuhlmann, A.; Neuweiler, I.; Zee, van der S.E.A.T.M.; Helmig, R.

    2012-01-01

    We analyze the combined effects of the spatial variability of soil hydraulic properties and the water uptake by plant roots on unsaturated water flow. For this analysis, we use a simplified macroscopic root water uptake model which is usually applied only for homogeneous or layered soil and

  8. MODFLOW-based coupled surface water routing and groundwater-flow simulation

    Science.gov (United States)

    Hughes, Joseph D.; Langevin, Christian D.; White, Jeremy T.

    2015-01-01

    In this paper, we present a flexible approach for simulating one- and two-dimensional routing of surface water using a numerical surface water routing (SWR) code implicitly coupled to the groundwater-flow process in MODFLOW. Surface water routing in SWR can be simulated using a diffusive-wave approximation of the Saint-Venant equations and/or a simplified level-pool approach. SWR can account for surface water flow controlled by backwater conditions caused by small water-surface gradients or surface water control structures. A number of typical surface water control structures, such as culverts, weirs, and gates, can be represented, and it is possible to implement operational rules to manage surface water stages and streamflow. The nonlinear system of surface water flow equations formulated in SWR is solved by using Newton methods and direct or iterative solvers. SWR was tested by simulating the (1) Lal axisymmetric overland flow, (2) V-catchment, and (3) modified Pinder-Sauer problems. Simulated results for these problems compare well with other published results and indicate that SWR provides accurate results for surface water-only and coupled surface water/groundwater problems. Results for an application of SWR and MODFLOW to the Snapper Creek area of Miami-Dade County, Florida, USA are also presented and demonstrate the value of coupled surface water and groundwater simulation in managed, low-relief coastal settings.

  9. Water flow and pesticide transport in cultivated sandy soils : experimental data on complications

    NARCIS (Netherlands)

    Leistra, M.; Boesten, J.J.T.I.

    2010-01-01

    The risk of leaching of agricultural pesticides from soil to groundwater and water courses has to be evaluated. Complications in water flow and pesticide transport in humic-sandy and loamy-sandy soil profiles can be expected to increase the risk of leaching. Much of the precipitation water is

  10. Granular flows at recurring slope lineae on Mars indicate a limited role for liquid water

    Science.gov (United States)

    Dundas, Colin M.; McEwen, Alfred S.; Chojnacki, Matthew; Milazzo, Moses P.; Byrne, Shane; McElwaine, Jim N.; Urso, Anna

    2017-12-01

    Recent liquid water flow on Mars has been proposed based on geomorphological features, such as gullies. Recurring slope lineae — seasonal flows that are darker than their surroundings — are candidate locations for seeping liquid water on Mars today, but their formation mechanism remains unclear. Topographical analysis shows that the terminal slopes of recurring slope lineae match the stopping angle for granular flows of cohesionless sand in active Martian aeolian dunes. In Eos Chasma, linea lengths vary widely and are longer where there are more extensive angle-of-repose slopes, inconsistent with models for water sources. These observations suggest that recurring slope lineae are granular flows. The preference for warm seasons and the detection of hydrated salts are consistent with some role for water in their initiation. However, liquid water volumes may be small or zero, alleviating planetary protection concerns about habitable environments.

  11. Signal classification and event reconstruction for acoustic neutrino detection in sea water with KM3NeT

    Science.gov (United States)

    Kießling, Dominik

    2017-03-01

    The research infrastructure KM3NeT will comprise a multi cubic kilometer neutrino telescope that is currently being constructed in the Mediterranean Sea. Modules with optical and acoustic sensors are used in the detector. While the main purpose of the acoustic sensors is the position calibration of the detection units, they can be used as instruments for studies on acoustic neutrino detection, too. In this article, methods for signal classification and event reconstruction for acoustic neutrino detectors will be presented, which were developed using Monte Carlo simulations. For the signal classification the disk-like emission pattern of the acoustic neutrino signal is used. This approach improves the suppression of transient background by several orders of magnitude. Additionally, an event reconstruction is developed based on the signal classification. An overview of these algorithms will be presented and the efficiency of the classification will be discussed. The quality of the event reconstruction will also be presented.

  12. Signal classification and event reconstruction for acoustic neutrino detection in sea water with KM3NeT

    Directory of Open Access Journals (Sweden)

    Kießling Dominik

    2017-01-01

    Full Text Available The research infrastructure KM3NeT will comprise a multi cubic kilometer neutrino telescope that is currently being constructed in the Mediterranean Sea. Modules with optical and acoustic sensors are used in the detector. While the main purpose of the acoustic sensors is the position calibration of the detection units, they can be used as instruments for studies on acoustic neutrino detection, too. In this article, methods for signal classification and event reconstruction for acoustic neutrino detectors will be presented, which were developed using Monte Carlo simulations. For the signal classification the disk–like emission pattern of the acoustic neutrino signal is used. This approach improves the suppression of transient background by several orders of magnitude. Additionally, an event reconstruction is developed based on the signal classification. An overview of these algorithms will be presented and the efficiency of the classification will be discussed. The quality of the event reconstruction will also be presented.

  13. Core Flow Distribution from Coupled Supercritical Water Reactor Analysis

    Directory of Open Access Journals (Sweden)

    Po Hu

    2014-01-01

    Full Text Available This paper introduces an extended code package PARCS/RELAP5 to analyze steady state of SCWR US reference design. An 8 × 8 quarter core model in PARCS and a reactor core model in RELAP5 are used to study the core flow distribution under various steady state conditions. The possibility of moderator flow reversal is found in some hot moderator channels. Different moderator flow orifice strategies, both uniform across the core and nonuniform based on the power distribution, are explored with the goal of preventing the reversal.

  14. Flow and transport in water repellent sandy soils

    NARCIS (Netherlands)

    Ritsema, C.J.

    1998-01-01

    Water repellency in soils is currently receiving increasing attention from scientists and policy makers, due to the adverse and sometimes devastating effects of soil water repellency on environmental quality and agricultural crop production. Soil water repellency often leads to severe

  15. Fire flow water consumption in sprinklered and unsprinklered buildings an assessment of community impacts

    CERN Document Server

    Code Consultants, Inc.

    2012-01-01

    Fire Flow Water Consumption in Sprinklered and Unsprinklered Buildings offers a detailed analysis for calculating the fire water demand required in buildings with existing and non-existant sprinkler systems. The installation of automatic sprinkler systems can significantly reduce the amount of water needed during a fire, but it requires water for commissioning, inspection, testing, and maintenance (CITM). This book provides an estimate of fire water used under both fire conditions, including CITM, to allow communities to develop fire water fees for both sprinklered and unsprinklered buildings that are proportional to the anticipated fire water usage. The types of buildings analyzed include residential (family dwellings as well as those up to four stories in height), business, assembly, institutional, mercantile, and storage facilities. Water volume was studied using guidelines from the International Code Council, the National Fire Protection Association, and the Insurance Services Office. Fire Flow Water Cons...

  16. A water tunnel flow visualization study of the vortex flow structures on the F/A-18 aircraft

    Science.gov (United States)

    Sandlin, Doral R.; Ramirez, Edgar J.

    1991-01-01

    The vortex flow structures occurring on the F/A-18 aircraft at high angles of attack were studied. A water tunnel was used to gather flow visualization data on the forebody vortex and the wing leading edge extension vortex. The longitudinal location of breakdown of the leading edge vortex was found to be consistently dependent on the angle of attack. Other parameters such as Reynolds number, model scale, and model fidelity had little influence on the overall behavior of the flow structures studied. The lateral location of the forebody vortex system was greatly influenced by changes in the angle of sideslip. Strong interactions can occur between the leading edge extension vortex and the forebody vortex. Close attention was paid to vortex induced flows on various airframe components of the F/A-18. Reynolds number and angle of attack greatly affected the swirling intensity, and therefore the strength of the studied vortices. Water tunnel results on the F/A-18 correlated well with those obtained in similar studies at both full and sub scale levels. The water tunnel can provide, under certain conditions, good simulations of realistic flows in full scale configurations.

  17. 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.

  18. Flow cytometry total cell counts : A field study assessing microbiological water quality and growth in unchlorinated drinking water distribution systems

    NARCIS (Netherlands)

    Liu, G.; Van der Mark, E.J.; Verberk, J.Q.; Van Dijk, J.C.

    2013-01-01

    e objective of this study was to evaluate the application of flow cytometry total cell counts (TCCs) as a parameter to assess microbial growth in drinking water distribution systems and to determine the relationships between different parameters describing the biostability of treated water. A

  19. Summary of Spring Flow and Surface Water Flow at Wetland Sites in the Albion Basin, Little Cottonwood Canyon, Alta, Utah

    Science.gov (United States)

    Skalbeck, J.; MacAlister, E. A.; Potter, N. A.; Clancy, J.

    2016-12-01

    A hydrologic and geochemical investigation of the Albion Basin was initiated in August 2005 that included reviewing existing reports, publications, maps, and other available data and preparing a phased research plan. Annual field investigations have continued with the goal to evaluate watershed characteristics of the Albion Basin and provide scientific information for use in watershed management decisions. The late July 2016 field season represents the 11th monitoring period for this investigation. Annual monitoring consists of collecting: (1) automated water levels using pressure transducers, (2) manual water levels using an electronic sounder, (3) field water parameters (temperature, pH, electrical conductivity), and (4) water samples for laboratory chemical analysis of major cations and anions. Water samples have been collected from piezometers, springs, surface water, and snow to characterize the potential source water for the wetland areas. A reconnaissance survey of springs located in each of the wetland areas (Albion Basin Fen, Catherine's Pass, and Collins/Sugarloaf) within the basin was performed during the August 2013 field season. A record of general vegetation and rock type, water field water parameter measurements, and relative flow characteristics were collected at each spring location. Subsequent surveys were performed during the 2014, 2015, and 2016 field seasons. Flow rates were measured using a simple weir (PVC pipe) to fill either a 16 ounce plastic cup or 5 gallon bucket and timed with a stop watch. Measurement of inflow and outflow for each wetland are analyzed with respect to the wetland area. Results show seasonal variation of source contribution between wetland areas. The goal is to assess the contribution of source water and to identify the volume of water needed to support each wetland area. This data may be useful for future evaluation of water diversions within the basin and assessing the effects of climate change on the watershed.

  20. Computational Flow Dynamic Simulation of Micro Flow Field Characteristics Drainage Device Used in the Process of Oil-Water Separation

    Directory of Open Access Journals (Sweden)

    Guangya Jin

    2017-01-01

    Full Text Available Aqueous crude oil often contains large amounts of produced water and heavy sediment, which seriously threats the safety of crude oil storage and transportation. Therefore, the proper design of crude oil tank drainage device is prerequisite for efficient purification of aqueous crude oil. In this work, the composition and physicochemical properties of crude oil samples were tested under the actual conditions encountered. Based on these data, an appropriate crude oil tank drainage device was developed using the principle of floating ball and multiphase flow. In addition, the flow field characteristics in the device were simulated and the contours and streamtraces of velocity magnitude at different nine moments were obtained. Meanwhile, the improvement of flow field characteristics after the addition of grids in crude oil tank drainage device was validated. These findings provide insights into the development of effective selection methods and serve as important references for oil-water separation process.

  1. Comparisons of the hydraulics of water flows in Martian outflow channels with flows of similar scale on earth

    Science.gov (United States)

    Komar, P. D.

    1979-01-01

    The hydraulics of channelized water flows on Mars and the resulting sediment transport rates are calculated, and similar computations are performed for such terrestrial analogs as the Mississippi River and the catastrophic Lake Missoula floods that formed the Channeled Scabland in eastern Washington State. The morphologies of deep-sea channels formed by catastrophic turbidity currents are compared with the Martian channels, many similarities are pointed out, and the hydraulics of the various flows are compared. The results indicate that the velocities, discharges, bottom shear stresses, and sediment-transport capacity of water flows along the Martian channels would be comparable to those of the oceanic turbidity currents and the Lake Missoula floods. It is suggested that the submarine canyons from which turbidity currents originate are the terrestrial counterparts to the chaotic-terrain areas or craters that serve as sources for many of the Martian channels.

  2. Analysis of virtual water flows associated with the trade of maize in the SADC region: importance of scale

    Directory of Open Access Journals (Sweden)

    J. M. Dabrowski

    2009-10-01

    Full Text Available The concept of virtual water encourages a country to view agricultural crops in terms of the amount of water required to produce those crops, with a view to implementing trading policies that promote the saving of scarce water resources. Recently, increased attention has focussed on partitioning the virtual water content of crops into green and blue water (derived from rainfall and irrigation, respectively as the latter has higher opportunity costs associated with its use and therefore impacts directly on scarcity. Maize is the most important crop traded within the SADC region. South Africa is the largest producer and exporter of maize, with the majority of its exports destined for other SADC countries. In comparison to other SADC countries, South Africa produces maize relatively efficiently, with a low virtual water content and a high green (868 m3 t−1 to blue (117 m3 t−1 water ratio. The blue water content is however higher than for maize produced in all other SADC countries, with the exception of Namibia (211 m3 t−1. Current trade patterns therefore result in a net expenditure of blue water (66×106 m3, almost all of which is exported by South Africa (65×106 m3. South Africa is one of the most water scarce countries in the region and analysis of virtual water flows indicates that current SADC maize trading patterns are influenced by national productivity as opposed to water scarcity. The virtual water content of maize was estimated for each of South Africa's nineteen Water Management Area's (WMA and used as a proxy to represent water use efficiency for maize production. The virtual water content varied widely across all of the WMAs, ranging from 360 m3 t−1 in the Ustutu Mhlatuze to 1000 m3 t−1 in the Limpopo. A comparison of the virtual water content and production of maize

  3. Modelling air―water flows in bottom outlets of dams

    OpenAIRE

    Liu, Ting

    2014-01-01

    If air is entrained in a bottom outlet of a dam in an uncontrolled way, the resulting air pockets may cause problems such as blowback, blowout and loss of discharge capacity. In order to provide guidance for bottom outlet design and operation, this study examines how governing parameters affect air entrainment, air-pocket transport and de-aeration and the surrounding flow structure in pipe flows. Both experimental and numerical approaches are used. Air can be entrained into the bottom outlet ...

  4. Experimental investigation on water flow in cubic arrays of spheres

    Science.gov (United States)

    Huang, K.; Wan, J. W.; Chen, C. X.; He, L. Q.; Mei, W. B.; Zhang, M. Y.

    2013-06-01

    One-dimensional uniform flow in homogeneous porous media was experimentally investigated. Head drop experiments were conducted in four test tubes with cubic arrays of spheres in diameter 3 mm, 5 mm, 8 mm and 10 mm. The experimental results indicate that Darcy’s law should be an approximate expression by neglecting the inertial term for flow at low velocity. Nonlinearity is attributed to inertial term in porous medium before the turbulent flow emerges. Forchheimer equation with constant coefficients can well predict the flow in porous medium. The relationship between the diameter of the particles and the coefficients a and b in the equations were verified. Different Ergun type equations were used to predict the head drop and compared to the experimental data. It shows that the Irmay equation could well predict the fluid flow in cubic arrays of spheres, while the prediction of head drop by Ergun equation was much higher than observed data. It indicates that the coefficients α and β in the Ergun type equations have certain relations with porosity or the pore structure and would vary for different medium. The discontinuity observed was interpreted by transition from steady flow to weakly turbulence and compared with previous studies.

  5. Estimating Monthly Water Withdrawals, Return Flow, and Consumptive Use in the Great Lakes Basin

    Science.gov (United States)

    Shaffer, Kimberly H.; Stenback, Rosemary S.

    2010-01-01

    Water-resource managers and planners require water-withdrawal, return-flow, and consumptive-use data to understand how anthropogenic (human) water use affects the hydrologic system. Water models like MODFLOW and GSFLOW use calculations and input values (including water-withdrawal and return flow data) to simulate and predict the effects of water use on aquifer and stream conditions. Accurate assessments of consumptive use, interbasin transfer, and areas that are on public supply or sewer are essential in estimating the withdrawal and return-flow data needed for the models. As the applicability of a model to real situations depends on accurate input data, limited or poor water-use data hampers the ability of modelers to simulate and predict hydrologic conditions. Substantial differences exist among the many agencies nationwide that are responsible for compiling water-use data including what data are collected, how the data are organized, how often the data are collected, quality assurance, required level of accuracy, and when data are released to the public. This poster presents water-use information and estimation methods summarized from recent U.S. Geological Survey (USGS) reports with the intent to assist water-resource managers and planners who need estimates of monthly water withdrawals, return flows, and consumptive use. This poster lists references used in Shaffer (2009) for water withdrawals, consumptive use, and return flows. Monthly percent of annual withdrawals and monthly consumptive-use coefficients are used to compute monthly water withdrawals, consumptive use, and return flow for the Great Lakes Basin.

  6. Measuring device for purging water flow rate in control rod drive

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Hiroshi.

    1993-11-12

    The device of the present invention enables highly accurate measurement for an amount of purging water supplied to control rod drives of a BWR type reactor. That is, purging water is supplied from an inlet of a scram line of the control rod drives. A temperature measuring portion is disposed, for measuring temperature fluctuation of purging water, to a hydropressure control unit for providing pressure and flow rate of water required for supplying the purging water and scram operation. An instrumentation section is disposed for calculating the flow rate of purging water based on the measured data obtained in the section. An output device is disposed for outputting a flow rate value of the purging water based on the result of the calculation obtained therein. With such a constitution, flow rate of the purging water can be measured quantitatively at the hydropressure control unit. Accordingly, influences, such as fluctuation of reactor core temperature are reduced, and accuracy for the measurement of the purging water flow rate is improved. As a result, reactor safety and maintainability can be improved. (I.S.).

  7. The Detection of Water Flow in Rectangular Microchannels by Terahertz Time Domain Spectroscopy.

    Science.gov (United States)

    Song, Yan; Zhao, Kun; Zuo, Jian; Wang, Cuicui; Li, Yizhang; Miao, Xinyang; Zhao, Xiaojing

    2017-10-13

    Flow characteristics of water were tested in a rectangular microchannel for Reynolds number (Re) between 0 and 446 by terahertz time domain spectroscopy (THz-TDS). Output THz peak trough intensities and the calculated absorbances of the flow were analyzed theoretically. The results show a rapid change for Re flow beginning nearly at Re = 250. Then this finding is confirmed in the plot of the flow resistant. Our results demonstrate that the THz-TDS could be a valuable tool to monitor and character the flow performance in microscale structures.

  8. Microbial activity in district cooling nets; Mikrobiell Aktivitet i Fjaerrkylenaet

    Energy Technology Data Exchange (ETDEWEB)

    Nordling, Magnus [Swedish Corrosion Inst., Stockholm (Sweden)

    2004-07-01

    Four district cooling nets with varying water quality have been investigated according to presence of microbially related problems. The aim has been to formulate recommendations regarding the water quality and regarding other procedures that might reduce the risk for biofilm formation and microbial corrosion. The method has consisted of using so called exposure containers, connected to each net. The water has been allowed to flow through the exposure containers where coupons of carbon steel have been exposed. The coupons have been withdrawn at different times, and analysed regarding the presence of biofilm and corrosion attack. Analyses have also been made regarding the amount of a number of different types of micro-organisms in the biofilm and in the district cooling water. The project has been divided in two phases. During the first phase of the project only two nets were investigated, one with municipal water and one with water of district heating quality, i.e. degassed and deionised. Biofilms could be seen on the coupons from both nets, even though the exposure time only had been 1.5 month. Considerable concentrations of micro-organisms were found in the biofilms and in the water for both nets, however much larger amounts for the net with municipal water. During the second phase of the project four nets were investigated, two with mainly municipal water and two with water of district heating quality. Here, on the other hand, it could be seen that the two nets with municipal water had micro-organisms of equivalent or lower concentrations compared to the two nets with water of district heating quality. One explanation to this is that the colouring substance pyranine is added to these two nets. Pyranine is added for the purpose of easily detecting a leakage but is at the same time a carbon compound, and as such a possible nutrient for the micro-organisms. This illustrates the importance of having the district cooling water as free from additives as possible. Other

  9. Quantifying green water flows for improved Integrated Land and Water Resource Management under the National Water Act of South Africa: A review on hydrological research in South Africa.

    Science.gov (United States)

    Jarmain, C.; Everson, C. S.; Gush, M. B.; Clulow, A. D.

    2009-09-01

    The contribution of hydrological research in South Africa in quantifying green water flows for improved Integrated Land and Water Resources Management is reviewed. Green water refers to water losses from land surfaces through transpiration (seen as a productive use) and evaporation from bare soil (seen as a non-productive use). In contrast, blue water flows refer to streamflow (surface water) and groundwater / aquifer recharge. Over the past 20 years, a number of methods have been used to quantify the green water and blue water flows. These include micrometeorological techniques (e.g. Bowen ratio energy balance, eddy covariance, surface renewal, scintillometry, lysimetry), field scale models (e.g. SWB, SWAP), catchment scale hydrological models (e.g. ACRU, SWAT) and more recently remote sensing based models (e.g. SEBAL, SEBS). The National Water Act of South Africa of 1998 requires that water resources are managed, protected and used (developed, conserved and controlled) in an equitable way which is beneficial to the public. The quantification of green water flows in catchments under different land uses has been pivotal in (a) regulating streamflow reduction activities (e.g. forestry) and the management of alien invasive plants, (b) protecting riparian and wetland areas through the provision of an ecological reserve, (c) assessing and improving the water use efficiency of irrigated pastures, fruit tree orchards and vineyards, (d) quantifying the potential impact of future land uses like bio-fuels (e.g. Jatropha) on water resources, (e) quantifying water losses from open water bodies, and (f) investigating "biological” mitigation measures to reduce the impact of polluted water resources as a result of various industries (e.g. mining). This paper therefore captures the evolution of measurement techniques applied across South Africa, the impact these results have had on water use and water use efficiency and the extent to which it supported the National Water Act of

  10. Computer code of two-phase flow in geothermal wells producing water and/or water-carbon dioxide mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Tanka, Shouichi; Nishi, Kosuke

    1988-01-01

    Mathematical well models are developed for pure water and for water-carbon dioxide mixtures. For the slug flow regime, three correlations (Orkiszewski’s, Nicklin’s and modified Nicklin’s) are compared. An equation-of-state package for water-carbon dioxide mixtures is proposed as a function of pressure and temperature. The predicted values are compared with sixteen field cases, in which the maximum carbon dioxide content is 2.8 %.

  11. Linking Flow Regime and Water Quality in Rivers: a Challenge to Adaptive Catchment Management

    Directory of Open Access Journals (Sweden)

    Christer Nilsson

    2008-12-01

    Full Text Available Water quality describes the physicochemical characteristics of the water body. These vary naturally with the weather and with the spatiotemporal variation of the water flow, i.e., the flow regime. Worldwide, biota have adapted to the variation in these variables. River channels and their riparian zones contain a rich selection of adapted species and have been able to offer goods and services for sustaining human civilizations. Many human impacts on natural riverine environments have been destructive and present opportunities for rehabilitation. It is a big challenge to satisfy the needs of both humans and nature, without sacrificing one or the other. New ways of thinking, new policies, and institutional commitment are needed to make improvements, both in the ways water flow is modified in rivers by dam operations and direct extractions, and in the ways runoff from adjacent land is affected by land-use practices. Originally, prescribed flows were relatively static, but precepts have been developed to encompass variation, specifically on how water could be shared over the year to become most useful to ecosystems and humans. A key aspect is how allocations of water interact with physicochemical variation of water. An important applied question is how waste releases and discharge can be managed to reduce ecological and sanitary problems that might arise from inappropriate combinations of flow variation and physicochemical characteristics of water. We review knowledge in this field, provide examples on how the flow regime and the water quality can impact ecosystem processes, and conclude that most problems are associated with low-flow conditions. Given that reduced flows represent an escalating problem in an increasing number of rivers worldwide, managers are facing enormous challenges.

  12. Smolt Passage Behavior and Flow-Net Relationship in the Forebay of John Day Dam, 1984-1985 Final Report of Research.

    Energy Technology Data Exchange (ETDEWEB)

    Giorgi, Albert E.

    1985-12-01

    The migration routes of downstream migrant salmonids in the forebay of John Day Dam were defined and assessed in relation to current velocities and water turbidity and temperature. Forebay current patterns were obtained from current meters at fixed sampling stations, the distribution of outmigrants was determined from purse seine sampling, and migration routes of yearling chinook salmon and steelhead were identified by radio telemetry techniques. All species of emigrating salmonids alter their distribution across the forebay as they approach the dam. Fish abundance was positively correlated with water clarity. There was no evidence to suggest that the migration routes were in response to current patterns in the forebay. Radio telemetry studies demonstrated that a certain segment of yearling chinook salmon approaching the dam are predisposed to spill passage (Washington side of the river) by virtue of their lateral position across the forebay. A new application of radio tag methodology was assessed and found to be useful in evaluating the effectiveness of spill for bypassing outmigrant salmon. A program system and cartographic model was developed which displays for any specified hour forebay current patterns at prevailing river flows and dam operations. The system can be used at other dam sites where investigations may wish to detail forebay current patterns.

  13. Flow system boundary by D'Agnese and others (1997) for the Death Valley regional ground-water flow system study, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the flow-system boundary encompassing the regional ground-water flow model by D'Agnese and others (1997). The boundary encompasses an...

  14. What part of natural flow can be considered a "water resource"?

    Directory of Open Access Journals (Sweden)

    V. Andréassian

    2015-04-01

    Full Text Available In this paper, we discuss an unfortunate semantic shortcut – the use of the expression "water resources" as a synonym for "river/groundwater flow" – which causes great confusion in all Water Security-related discussions. We show that only a part of the flow can be considered a resource, and that the efficiency of the flow-to-resource conversion is a complex function of: (i the hydrologic regime, (ii environmental constraints (in-stream reserved flows, (iii the type of water demand, and (iv the existence of artificial reservoirs. Last, we illustrate how the flow-to-resource conversion can be affected by future climatic changes. Hydrologic data and climate change simulations for three French rivers (the rivers Vilaine, Durance and Garonne are used to illustrate this discussion.

  15. Water Flow in Karst Aquifer Considering Dynamically Variable Saturation Conduit

    Science.gov (United States)

    Tan, Chaoqun; Hu, Bill X.

    2017-04-01

    The karst system is generally conceptualized as dual-porosity system, which is characterized by low conductivity and high storage continuum matrix and high conductivity and quick flow conduit networks. And so far, a common numerical model for simulating flow in karst aquifer is MODFLOW2005-CFP, which is released by USGS in 2008. However, the steady-state approach for conduit flow in CFP is physically impractical when simulating very dynamic hydraulics with variable saturation conduit. So, we adopt the method proposed by Reimann et al. (2011) to improve current model, in which Saint-Venant equations are used to model the flow in conduit. Considering the actual background that the conduit is very big and varies along flow path and the Dirichlet boundary varies with rainfall in our study area in Southwest China, we further investigate the influence of conduit diameter and outflow boundary on numerical model. And we also analyze the hydraulic process in multi-precipitation events. We find that the numerical model here corresponds well with CFP for saturated conduit, and it could depict the interaction between matrix and conduit during very dynamic hydraulics pretty well compare with CFP.

  16. Toward a conceptual model relating chemical reaction fronts to water flow paths in hills

    Science.gov (United States)

    Brantley, Susan L.; Lebedeva, Marina I.; Balashov, Victor N.; Singha, Kamini; Sullivan, Pamela L.; Stinchcomb, Gary

    2017-01-01

    Both vertical and lateral flows of rock and water occur within eroding hills. Specifically, when considered over geological timeframes, rock advects vertically upward under hilltops in landscapes experiencing uplift and erosion. Once rock particles reach the land surface, they move laterally and down the hillslope because of erosion. At much shorter timescales, meteoric water moves vertically downward until it reaches the regional water table and then moves laterally as groundwater flow. Water can also flow laterally in the shallow subsurface as interflow in zones of permeability contrast. Interflow can be perched or can occur during periods of a high regional water table. The depths of these deep and shallow water tables in hills fluctuate over time. The fluctuations drive biogeochemical reactions between water, CO2, O2, and minerals and these in turn drive fracturing. The depth intervals of water table fluctuation for interflow and groundwater flow are thus reaction fronts characterized by changes in composition, fracture density, porosity, and permeability. The shallow and deep reaction zones can separate over meters in felsic rocks. The zones act like valves that reorient downward unsaturated water flow into lateral saturated flow. The valves also reorient the upward advection of rock into lateral flow through solubilization. In particular, groundwater removes highly soluble, and interflow removes moderately soluble minerals. As rock and water moves through the system, hills may evolve toward a condition where the weathering advance rate, W, approaches the erosion rate, E. If W = E, the slopes of the deep and shallow reaction zones and the hillsides must allow removal of the most soluble, moderately soluble, and least soluble minerals respectively. A permeability architecture thus emerges to partition each evolving hill into dissolved and particulate material fluxes as it approaches steady state.

  17. Water flow in soil and plants: the importance of good contacts

    Science.gov (United States)

    Carminati, A.

    2009-04-01

    Water flow in unsaturated porous media is controlled by the continuity of the liquid phase through the pore system. In many cases, the pore system is composed of regions with different material properties separated by interfaces containing macro-pores or gaps that are easily drained. When these gaps are drained the continuity of the liquid flow path may break, with a consequent decrease in the conductivity of the medium. We present two examples demonstrating the controlling role of interfaces on water flow. The first example describes an aggregated soil. Due to the aggregate roughness, the inter-aggregate contacts contain macro-pores which are rapidly drained. The hydraulic behavior of contacts varies from highly conductive when water fills the contact to a bottle-neck to flow as water pressure drops and contact asperities rapidly drained. The conductivity of the system is determined by the water-filled contact area between aggregates, rather then by the average volumetric water content. The second example refers to the contacts between soil and roots. By means of X-ray tomography we showed that during periods of drought, roots shrink and may lose contact with the soil, with a consequent reduction in water uptake. When the soil is irrigated again, roots swell partially refilling the gaps. Opening and closing of gaps may help plant to optimize water use, to prevent water loss when soil dries, and to restore the soil-root continuity after irrigation. Additionally, soil-root continuity is improved by root exudates and root hairs, which make the soil-root interface a complex and dynamic biomaterial with specific and unique properties. These two examples show that interfaces between heterogeneous media can have a big impact on water flow in porous media and demonstrate that volumetric averaging for predicting transport properties can lead to wrong results. An approach based on flow cross sections and interfacial properties may be the way to a deeper understanding and

  18. Metabolic inhibition of root water flow in red-osier dogwood (Cornus stolonifera) seedlings

    National Research Council Canada - National Science Library

    M. Kamaluddin; Janusz J. Zwiazek

    2001-01-01

    .... NaN3 significantly decreased root water flow rates (Qv). It also induced a significant reduction in root respiration and reduced stomatal conductance to a greater extent in intact seedlings than in excised shoots...

  19. Hydrogeologic map of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset represents the surface hydrogeology of an approximately 45,000 square-kilometer area of the Death Valley regional ground-water flow system...

  20. Water Level Altitude Contours for the Diamond Valley Flow System, Central Nevada, 2012

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data were created as part of a hydrologic study to characterize groundwater budgets and water quality in the Diamond Valley Flow System (DVFS), central Nevada....

  1. Changing patterns of global agri-food trade and virtual water flows

    OpenAIRE

    Schwarz, Jana; Mathijs, Erik; Maertens, Miet

    2015-01-01

    An updated version of this working paper is published as: Schwarz, J., Mathijs, E. and Maertens, M. (2015) Changing Patterns of Global Agri-Food Trade and the Economic Efficiency of Virtual Water Flows. Sustainability 7, 5542-5563

  2. Flow Behaviour of Creosote-in-Water Emulsions through Straight and Square Wave Capillary Tubes

    National Research Council Canada - National Science Library

    Podolsak, A.K; Tiu, C

    1994-01-01

    ...) and water-in-creosote (W/O) emulsions at moderate shear rates. This paper investigates the flow of O/Wemulsions in straight and square-wave capillaries at high shear rates, as a preludeto predicting timber treatability...

  3. Study area boundary for the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set represents the Death Valley regional ground-water flow system (DVRFS) study area which encompasses approximately 100,000-square kilometers in...

  4. Intra-EU agricultural trade, virtual water flows and policy implications.

    Science.gov (United States)

    Antonelli, M; Tamea, S; Yang, H

    2017-06-01

    The development of approaches to tackle the European Union (EU) water-related challenges and shift towards sustainable water management and use is one of the main objectives of Horizon 2020, the EU strategy to lead a smart, sustainable and inclusive growth. The EU is an increasingly water challenged area and is a major agricultural trader. As agricultural trade entails an exchange of water embodied in goods as a factor of production, this study investigates the region's water-food-trade nexus by analysing intra-regional virtual water trade (VWT) in agricultural products. The analysed period (1993-2011) comprises the enactment of the Water Framework Directive (WFD) in the year 2000. Aspects of the VWT that are relevant for the WFD are explored. The EU is a net importer of virtual water (VW) from the rest of the world, but intra-regional VWT represents 46% of total imports and 75% of total exports. Five countries account for 60% of total VW imports (Germany, France, Italy, The Netherlands, Belgium) and 65% of total VW exports (The Netherlands, France, Germany, Belgium and Spain). Intra-EU VWT more than doubled over the period considered, while trade with extra-EU countries did not show such a marked trend. In the same period, blue VWT increased significantly within the region and net import from the rest of the world slightly decreased. Water scarce countries, such as Spain and Italy, are major exporters of blue water in the region. The traded volumes of VW have been increasing almost monotonically over the years, and with a substantial increase after 2000. The overall trend in changes in VWT does not seem to be in accordance with the WFD goals. This study demonstrated that VWT analyses can help evaluate intertwining effects of water, agriculture and trade policies which are often made separately in respective sectors. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. The Transitional Backward-Facing Step Flow in a Water Channel with Variable Expansion Geometry

    OpenAIRE

    Tihon, J. (Jaroslav); Pěnkavová, V. (Věra); Havlica, J. (Jaromír); Šimčík, M. (Miroslav)

    2012-01-01

    The backward-facing step flow is investigated experimentally and numerically at moderate Reynolds numbers. The different channel expansion ratios (ER = 1.4, 2, 2.5, and 4) and inlet flow conditions (steady and pulsatile) are applied with the aim to analyze the structure and stability of the flow behind the step. The electrodiffusion technique is used to measure the wall shear rate along the experimental water channel. The direction sensitive sensors detect the near-wall extent of different fl...

  6. Three-dimensional flow measurement of a water flow in a sphere-packed pipe by digital holographic PTV

    Energy Technology Data Exchange (ETDEWEB)

    Satake, Shin-ichi, E-mail: satake@te.noda.tus.ac.jp [Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585 (Japan); Aoyagi, Yusuke [Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585 (Japan); Unno, Noriyuki [Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585 (Japan); Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083 (Japan); Yuki, Kazuhisa [Department of Mechanical Engineering, Tokyo University of Science, Yamaguchi, Daigaku-dori 1-1-1, Sanyo-Onoda, Yamaguchi 756-0884 (Japan); Seki, Yohji; Enoeda, Mikio [Japan Atomic Energy Agency, Blanket Technology Group, 801-1 Mukoyama, Naka-shi, Ibaraki-ken 311-0193 (Japan)

    2015-10-15

    A water cooled ceramic breeder for ITER and DEMO of a nuclear fusion reactor plays a significant role in the design of a blanket module. Pebbles of a ceramic tritium breeder are packed in a container of the blanket. Investigation of the flow behavior is necessary in an actual environment of a facility where pressure drop takes place under a complex flow such as in case of the container for the pebble bed. For the development of a facility, it is necessary to be able to monitor fluid motion of a basic flow such as a sphere-packed pipe (SPP). In the present study, to discern the complex flow structures in SPP, digital holographic PTV visualization is carried out by a refractive index-matching method using a water employed as a working fluid. The water is chosen to be able to adjust its refractive index to match to that of the MEXFLON pebble with an index of 1.33. Hologram fringe images of particles behind the spheres can be observed, and the particles’ positions can be reconstructed by a digital hologram. Consequently, 3-D velocity-fields around the spheres are obtained by the reconstructed particles’ positions. The velocity between pebbles is found to be convergence and divergence regions in the SPP.

  7. Weighted Interior Penalty discretization of fully nonlinear and weakly dispersive free surface shallow water flows

    OpenAIRE

    Di Pietro, Daniele,; Marche, Fabien,

    2017-01-01

    In this paper, we further investigate the use of a fully discontinuous Finite Element discrete formulation for the study of shallow water free surface flows in the fully nonlinear and weakly dis-persive flow regime. We consider a decoupling strategy in which we approximate the solutions of the classical shallow water equations supplemented with a source term globally accounting for the non-hydrostatic effects. This source term can be computed through the resolution of elliptic second-order li...

  8. One-dimensional model for heat transfer to a supercritical water flow in a tube

    NARCIS (Netherlands)

    Sallevelt, J.L.H.P.; Withag, J.A.M.; Bramer, Eduard A.; Brilman, Derk Willem Frederik; Brem, Gerrit

    2012-01-01

    Heat transfer in water at supercritical pressures has been investigated numerically using a one-dimensional modeling approach. A 1D plug flow model has been developed in order to make fast predictions of the bulk-fluid temperature in a tubular flow. The chosen geometry is a vertical tube with an

  9. Improving mixing efficiency in a closed circuit water flow rig for ...

    African Journals Online (AJOL)

    Investigations were conducted on a laboratory scale water flow rig to determine the flow characteristics for improving mixing efficiency in the tanks for radiotracer studies. Approximately 20 mCi eluates of 68Ga from 68Ge/ 68Ga generator were injected into the fluid at 1.0 and 1.2 minutes pulses in a second and third ...

  10. Detailed structure of pipe flow with water hammer oscillations | Kioni ...

    African Journals Online (AJOL)

    Herein, the evolution and detailed structure of velocity and pressure fields of an oscillating axi-symmetric pipe flow arising from a rapid closure of a valve has been determined through the solution, by the Finite Volume technique, of the full Navier Stokes equations. The method correctly predicts the distortion of the pressure ...

  11. Low-Flow Water Study for the Missouri River.

    Science.gov (United States)

    2008-08-01

    The (MoDOT) retained TranSystems to identify and review low-flow industry : trends, equipment and strategies used in inland navigation settings throughout the United States and worldwide which : may be transferable to the Missouri River and which cou...

  12. Non-equilibrium water flow in multimodal soil porous system

    Science.gov (United States)

    Kodesova, R.; Nikodem, A.; Jirku, V.

    2009-04-01

    Soil hydraulic properties of various horizons of Haplic Luvisol were studied under the laboratory and field conditions. Multistep outflow experiments were performed in the laboratory, and tension disk and Guelph permeameter tests were carried out in the field. The dual-permeability flow model in HYDRUS-1D and HYDRUS-2D were used to estimate the soil hydraulic parameters of matrix and macropore domains from the laboratory and field transient flow data via numerical inversion. First, the laboratory experimental data were analyzed to obtain soil hydraulic properties of the one-dimensional (small column) dual-permeability system. Parameters obtained for the matrix domains were then used to analyze field transient flow data of both permeameters tests to estimate parameters of macropore domains in the radially symmetric dual-permeability system. Results showed impact of various pore fractions (gravitational and large capillary pores) and multimodality of soil porous system, which were previously documented by Kodesova et al. (2008) in the micromorphological images, on preferential flow occurrence in structured soils. Acknowledgement: Authors acknowledge the financial support of the Grant Agency of the Czech Republic grant No. 526/08/0434, and the Ministry of Education, Youth and Sports grant No. MSM 6046070901.

  13. Model reduced variational data assimilation for shallow water flow models

    NARCIS (Netherlands)

    Altaf, M.U.

    2011-01-01

    Identifying uncertain parameters in large-scale numerical flow models can be done using the variational method. However, for implementing the variational method the adjoint model have to be available, which requires highly complex computer code and maintenance and thus hampers its applications. To

  14. [Stem sap flow and water consumption of Tamarix ramosissima in hinterland of Taklimakan Desert].

    Science.gov (United States)

    Xu, Hao; Zhang, Xi-Ming; Yan, Hai-Long; Yao, Shi-Jun

    2007-04-01

    From April to November 2005, the stem sap flow and water consumption of Tamarix ramosissima in the hinterland of Taklimakan Desert was measured by Flow-32 System. The results showed that, in the extremely arid hinterland of Taklimakan Desert and under enough water supply, the average daily water consumption of T. ramosissima with a stem diameter of 3.5 cm and 2.0 cm was 6.322 kg and 1.179 kg, respectively in one growth season. The stem sap flow of T. ramosissima presented a single-peaked curve, with an obvious day and night variation rhythm and fluctuated with environment factors. Under enough water supply, the environmenal factors such as total radiation, wind speed and air temperature were the main factors affecting the stem sap flow, and the dynamics of stem sap flow could be predicted by the liner regression model based on total radiation and wind speed. Because of the extremely arid environment and enough water supply, T. ramosissima had a relatively higher stem sap flow rate and a great water consumption.

  15. Sensitivity of boreal forest regional water flux and net primary production simulations to sub-grid-scale land cover complexity

    Science.gov (United States)

    Kimball, J. S.; Running, S. W.; Saatchi, S. S.

    1999-11-01

    We use a general ecosystem process model (BIOME-BGC) coupled with remote sensing information to evaluate the sensitivity of boreal forest regional evapotranspiration (ET) and net primary production (NPP) to land cover spatial scale. Simulations were conducted over a 3 year period (1994-1996) at spatial scales ranging from 30 to 50 km within the BOREAS southern modeling subarea. Simulated fluxes were spatially complex, ranging from 0.1 to 3.9 Mg C ha-1 yr-1 and from 18 to 29 cm yr-1. Biomass and leaf area index heterogeneity predominantly controlled this complexity, while biophysical differences between deciduous and coniferous vegetation were of secondary importance. Spatial aggregation of land cover characteristics resulted in mean monthly NPP estimation bias from 25 to 48% (0.11-0.20 g C m-2 d-1) and annual estimation errors from 2 to 14% (0.04-0.31 Mg C ha-1 yr-1). Error was reduced at longer time intervals because coarse scale overestimation errors during spring were partially offset by underestimation of fine scale results during summer and winter. ET was relatively insensitive to land cover spatial scale with an average bias of less than 5% (0.04 kg m-2 d-1). Factors responsible for differences in scaling behavior between ET and NPP included compensating errors for ET calculations and boreal forest spatial and temporal NPP complexity. Careful consideration of landscape spatial and temporal heterogeneity is necessary to identify and mitigate potential error sources when using plot scale information to understand regional scale patterns. Remote sensing data integrated within an ecological process model framework provides an efficient mechanism to evaluate scaling behavior, interpret patterns in coarse resolution data, and identify appropriate scales of operation for various processes.

  16. Prediction of unsaturated flow and water backfill during infiltration in layered soils

    Science.gov (United States)

    Cui, Guotao; Zhu, Jianting

    2018-02-01

    We develop a new analytical infiltration model to determine water flow dynamics around layer interfaces during infiltration process in layered soils. The model mainly involves the analytical solutions to quadratic equations to determine the flux rates around the interfaces. Active water content profile behind the wetting front is developed based on the solution of steady state flow to dynamically update active parameters in sharp wetting front infiltration equations and to predict unsaturated flow in coarse layers before the front reaches an impeding fine layer. The effect of water backfill to saturate the coarse layers after the wetting front encounters the impeding fine layer is analytically expressed based on the active water content profiles. Comparison to the numerical solutions of the Richards equation shows that the new model can well capture water dynamics in relation to the arrangement of soil layers. The steady state active water content profile can be used to predict the saturation state of all layers when the wetting front first passes through these layers during the unsteady infiltration process. Water backfill effect may occur when the unsaturated wetting front encounters a fine layer underlying a coarse layer. Sensitivity analysis shows that saturated hydraulic conductivity is the parameter dictating the occurrence of unsaturated flow and water backfill and can be used to represent the coarseness of soil layers. Water backfill effect occurs in coarse layers between upper and lower fine layers when the lower layer is not significantly coarser than the upper layer.

  17. Linking soil- and stream-water chemistry based on a Riparian Flow-Concentration Integration Model

    Directory of Open Access Journals (Sweden)

    J. Seibert

    2009-12-01

    Full Text Available The riparian zone, the last few metres of soil through which water flows before entering a gaining stream, has been identified as a first order control on key aspects of stream water chemistry dynamics. We propose that the distribution of lateral flow of water across the vertical profile of soil water chemistry in the riparian zone provides a conceptual explanation of how this control functions in catchments where matrix flow predominates. This paper presents a mathematical implementation of this concept as well as the model assumptions. We also present an analytical solution, which provides a physical basis for the commonly used power-law flow-load equation. This approach quantifies the concept of riparian control on stream-water chemistry providing a basis for testing the concept of riparian control. By backward calculation of soil-water-chemistry profiles, and comparing those with observed profiles we demonstrate that the simple juxtaposition of the vertical profiles of water flux and soil water chemistry provides a plausible explanation for observed variations in stream water chemistry of several major stream components such as Total Organic Carbon (TOC, magnesium, calcium and chloride. The "static" implementation of the model structure presented here provides a basis for further development to account for seasonal influences and hydrological hysteresis in the representation of hyporheic, riparian, and hillslope processes.

  18. Quantitative description of the relation between protein net charge and protein adsorption to air-water interfaces

    NARCIS (Netherlands)

    Wierenga, P.A.; Meinders, M.B.J.; Egmond, M.R.; Voragen, A.G.J.; Jongh, H.H.J.de

    2005-01-01

    In this study a set of chemically engineered variants of ovalbumin was produced to study the effects of electrostatic charge on the adsorption kinetics and resulting surface pressure at the air-water interface. The modification itself was based on the coupling of succinic anhydride to lysine

  19. SIMULATION OF NET INFILTRATION FOR MODERN AND POTENTIAL FUTURE CLIMATES

    Energy Technology Data Exchange (ETDEWEB)

    J.A. Heveal

    2000-06-16

    This Analysis/Model Report (AMR) describes enhancements made to the infiltration model documented in Flint et al. (1996) and documents an analysis using the enhanced model to generate spatial and temporal distributions over a model domain encompassing the Yucca Mountain site, Nevada. Net infiltration is the component of infiltrated precipitation, snowmelt, or surface water run-on that has percolated below the zone of evapotranspiration as defined by the depth of the effective root zone, the average depth below the ground surface (at a given location) from which water is removed by evapotranspiration. The estimates of net infiltration are used for defining the upper boundary condition for the site-scale 3-dimensional Unsaturated-Zone Ground Water Flow and Transport (UZ flow and transport) Model (CRWMS M&O 2000a). The UZ flow and transport model is one of several process models abstracted by the Total System Performance Assessment model to evaluate expected performance of the potential repository at Yucca Mountain, Nevada, in terms of radionuclide transport (CRWMS M&O 1998). The net-infiltration model is important for assessing potential repository-system performance because output from this model provides the upper boundary condition for the UZ flow and transport model that is used to generate flow fields for evaluating potential radionuclide transport through the unsaturated zone. Estimates of net infiltration are provided as raster-based, 2-dimensional grids of spatially distributed, time-averaged rates for three different climate stages estimated as likely conditions for the next 10,000 years beyond the present. Each climate stage is represented using a lower bound, a mean, and an upper bound climate and corresponding net-infiltration scenario for representing uncertainty in the characterization of daily climate conditions for each climate stage, as well as potential climate variability within each climate stage. The set of nine raster grid maps provide spatially

  20. Estimating water consumption of potential natural vegetation on global dry lands: building an LCA framework for green water flows.

    Science.gov (United States)

    Núñez, Montserrat; Pfister, Stephan; Roux, Philippe; Antón, Assumpció

    2013-01-01

    This study aimed to provide a framework for assessing direct soil-water consumption, also termed green water in the literature, in life cycle assessment (LCA). This was an issue that LCA had not tackled before. The approach, which is applied during the life cycle inventory phase (LCI), consists of quantifying the net change in the evapo(transpi)ration of the production system compared to the natural reference situation. Potential natural vegetation (PNV) is used as the natural reference situation. In order to apply the method, we estimated PNV evapotranspiration adapted to local biogeographic conditions, on global dry lands, where soil-water consumption impacts can be critical. Values are reported at different spatial aggregation levels: 10-arcmin global grid, ecoregions (501 units), biomes (14 units), countries (124 units), continents, and a global average, to facilitate the assessment for different spatial information detail levels available in the LCI. The method is intended to be used in rain-fed agriculture and rainwater harvesting contexts, which includes direct soil moisture uptake by plants and rainwater harvested and then reused in production systems. The paper provides the necessary LCI method and data for further development of impact assessment models and characterization factors to evaluate the environmental effects of the net change in evapo(transpi)ration.

  1. Simulation of the Effects of Water Withdrawals, Wastewater Return Flows, and Land-Use Change on Streamflow in the Blackstone River Basin, Massachusetts and Rhode Island

    Science.gov (United States)

    Barbaro, Jeffrey R.

    2007-01-01

    . Ratios of long-term (1960?2004) simulated flows with 1996?2001 water use (representing the net effect of withdrawals and wastewater-return flows) to long-term simulated flows with no water use indicated that, for many reaches, 1996?2001 water use did not deplete flows at the 90-percent flow duration substantially compared to flows unaffected by water use. Flows generally were more severely depleted in the reaches that include surface-water supplies for the larger cities in the basin (Kettle and Tatnuck Brooks, Worcester, Mass. water supply; Quinsigamond River, Shrewsbury, Mass. water supply; Crookfall Brook, Woonsocket, R.I. water supply; and Abbott Run, Pawtucket, R.I. water supply). These reaches did not have substantial wastewater-return flows that could offset the effects of the withdrawals. In contrast, wastewater-return flows from the Upper Blackstone Wastewater Treatment Facility in Millbury, Mass. increased flows at the 90-percent flow duration in the main stem of the Blackstone River compared to no-water-use conditions. Under the assumptions used to develop the buildout scenario, nearly all of the new water withdrawals were returned to the Blackstone River Basin at municipal wastewater-treatment plants or on-site septic systems. Consequently, buildout generally had small effects on simulated low flows in the Blackstone River and most of the major tributary streams compared to flows with 1996?2001 water use. To evaluate the effects of water use on flows in the rivers and major tributary streams in the Rhode Island part of the basin in greater detail, the magnitudes of water withdrawals and wastewater-return flows in relation to simulated streamflow were calculated as unique ratios for individual HSPF subbasins, total contributing areas to HSPF subbasins, and total contributing areas to the major tributary streams. For recent conditions (1996?2001 withdrawals and 1995?1999 land use), ratios of average summer (June through September) withdrawals to the l

  2. Formation of thermal flow fields and chemical transport in air and water by atmospheric plasma

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Tetsuji; Morfill, Gregor E [Max-Planck Institute for Extraterrestrial Physics, 85748 Garching (Germany); Iwafuchi, Yutaka [Graduate School of Engineering, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 9808577 (Japan); Sato, Takehiko, E-mail: sato@ifs.tohoku.ac.jp [Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 9808577 (Japan)

    2011-05-15

    Cold atmospheric plasma is a potential tool for medical purposes, e.g. disinfection/sterilization. In order for it to be effective and functional, it is crucial to understand the transport mechanism of chemically reactive species in air as well as in liquid. An atmospheric plasma discharge was produced between a platinum pin electrode and the surface of water. The thermal flow field of a cold atmospheric plasma as well as its chemical components was measured. A gas flow with a velocity of around 15 m s{sup -1} to the water's surface was shown to be induced by the discharge. This air flow induced a circulating flow in the water from the discharge point at the water's surface because of friction. It was also demonstrated that the chemical components generated in air dissolved in water and the properties of the water changed. The reactive species were believed to be distributed mainly by convective transport in water, because the variation in the pH profile indicated by a methyl red solution resembled the induced flow pattern.

  3. 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.

  4. A comparison of the coupled fresh water-salt water flow and the Ghyben-Herzberg sharp interface approaches to modeling of transient behavior in coastal aquifer systems

    Science.gov (United States)

    Essaid, H.I.

    1986-01-01

    A quasi-three dimensional finite difference model which simulates coupled, fresh water and salt water flow, separated by a sharp interface, is used to investigate the effects of storage characteristics, transmissivity, boundary conditions and anisotropy on the transient responses of such flow systems. The magnitude and duration of the departure of aquifer response from the behavior predicted using the Ghyben-Herzberg, one-fluid approach is a function of the ease with which flow can be induced in the salt water region. In many common hydrogeologic settings short-term fresh water head responses, and transitional responses between short-term and long-term, can only be realistically reproduced by including the effects of salt water flow on the dynamics of coastal flow systems. The coupled fresh water-salt water flow modeling approach is able to reproduce the observed annual fresh water head response of the Waialae aquifer of southeastern Oahu, Hawaii. ?? 1986.

  5. Fragmented Flows: Water Supply in Los Angeles County

    Science.gov (United States)

    Pincetl, Stephanie; Porse, Erik; Cheng, Deborah

    2016-08-01

    In the Los Angeles metropolitan region, nearly 100 public and private entities are formally involved in the management and distribution of potable water—a legacy rooted in fragmented urban growth in the area and late 19th century convictions about local control of services. Yet, while policy debates focus on new forms of infrastructure, restructured pricing mechanisms, and other technical fixes, the complex institutional architecture of the present system has received little attention. In this paper, we trace the development of this system, describe its interconnections and disjunctures, and demonstrate the invisibility of water infrastructure in LA in multiple ways—through mapping, statistical analysis, and historical texts. Perverse blessings of past water abundance led to a complex, but less than resilient, system with users accustomed to cheap, easily accessible water. We describe the lack of transparency and accountability in the current system, as well as its shortcomings in building needed new infrastructure and instituting new water rate structures. Adapting to increasing water scarcity and likely droughts must include addressing the architecture of water management.

  6. First testing of an AUV mission planning and guidance system for water quality monitoring and fish behavior observation in net cage fish farming

    Directory of Open Access Journals (Sweden)

    D. Karimanzira

    2014-12-01

    Full Text Available Recently, underwater vehicles have become low cost, reliable and affordable platforms for performing various underwater tasks. While many aquaculture systems are closed with no harmful output, open net cage fish farms and land-based fish farms can discharge significant amounts of wastewater containing nutrients, chemicals, and pharmaceuticals that impact on the surrounding environment. Although aquaculture development has often occurred outside a regulatory framework, government oversight is increasingly common at both the seafood quality control level, and at baseline initiatives addressing the basic problem of pollution generated by culture operations, e.g. the European marine and maritime directives. This requires regular, sustainable and cost-effective monitoring of the water quality. Such monitoring needs devices to detect the water quality in a large sea area at different depths in real time. This paper presents a concept for a guidance system for a carrier (an autonomous underwater vehicle of such devices for the automated detection and analysis of water quality parameters.

  7. Estimates of consumptive use and ground-water return flow using water budgets in Palo Verde Valley, California

    Science.gov (United States)

    Owen-Joyce, Sandra J.; Kimsey, Steven L.

    1987-01-01

    Palo Verde Valley, California, is an agricultural area in the flood plain of the Colorado River where irrigation water is diverted from the river and groundwater is discharged to a network of drainage ditches and (or) the river. Consumptive use by vegetation and groundwater return flow were calculated using water budgets. Consumptive use by vegetation was 484,000 acre-ft in 1981, 453,600 acre-ft in 1982, 364,400 acre-ft in 1983, and 374,300 acre-ft in 1984. The consumptive-use estimates are most sensitive to two measured components of the water budget, the diversion at Palo Verde Dam and the discharge from drainage ditches to the river. Groundwater return flow was 31,700 acre-ft in 1981, 24,000 acre-ft in 1982, 2,500 acre-ft in 1983, and 7 ,900 acre-ft in 1984. The return-flow estimates are most sensitive to discharge from drainage ditches; various irrigation requirements and crop areas, particularly alfalfa; the diversion at Palo Verde Dam; and the estimate of consumptive use. During increasing flows in the river, the estimate of groundwater return flow is sensitive also to change in groundwater storage. Change in groundwater storage was estimated to be -5,700 acre-ft in 1981, -12,600 acre-ft in 1982, 5,200 acre-ft in 1983, and 11 ,600 acre-ft in 1984. Changes in storage can be a significant component in the water budget used to estimate groundwater return flow but is negligible in the water budget used to estimate consumptive use. Change in storage was 1 to 3% of annual consumptive use. Change in storage for the area drained by the river ranged from 7 to 96% of annual groundwater return flow during the 4 years studied. Consumptive use calculated as diversions minus return flows was consistently lower than consumptive use calculated in a water budget. Water-budget estimates of consumptive use account for variations in precipitation, tributary inflow, river stage, and groundwater storage. The calculations for diversions minus return flows do not account for these

  8. Large eddy simulation of water flow over series of dunes

    Directory of Open Access Journals (Sweden)

    Jun LU

    2011-12-01

    Full Text Available Large eddy simulation was used to investigate the spatial development of open channel flow over a series of dunes. The three-dimensional filtered Navier-Stokes (N-S equations were numerically solved with the fractional-step method in sigma coordinates. The subgrid-scale turbulent stress was modeled with a dynamic coherent eddy viscosity model proposed by the authors. The computed velocity profiles are in good agreement with the available experimental results. The mean velocity and the turbulent Reynolds stress affected by a series of dune-shaped structures were compared and analyzed. The variation of turbulence statistics along the flow direction affected by the wavy bottom roughness has been studied. The turbulent boundary layer in a complex geographic environment can be simulated well with the proposed large eddy simulation (LES model.

  9. Impacts of impervious cover, water withdrawals, and climate change on river flows in the conterminous US

    Science.gov (United States)

    Caldwell, P. V.; Sun, G.; McNulty, S. G.; Cohen, E. C.; Moore Myers, J. A.

    2012-08-01

    Rivers are essential to aquatic ecosystem and societal sustainability, but are increasingly impacted by water withdrawals, land-use change, and climate change. The relative and cumulative effects of these stressors on continental river flows are relatively unknown. In this study, we used an integrated water balance and flow routing model to evaluate the impacts of impervious cover and water withdrawal on river flow across the conterminous US at the 8-digit Hydrologic Unit Code (HUC) watershed scale. We then estimated the impacts of projected change in withdrawals, impervious cover, and climate under the B1 "Low" and A2 "High" emission scenarios on river flows by 2060. Our results suggest that compared to no impervious cover, 2010 levels of impervious cover increased river flows by 9.9% on average with larger impacts in and downstream of major metropolitan areas. In contrast, compared to no water withdrawals, 2005 withdrawals decreased river flows by 1.4% on average with larger impacts in heavily irrigated arid regions of Western US. By 2060, impacts of climate change were predicted to overwhelm the potential gain in river flow due to future changes in impervious cover and add to the potential reduction in river flows from withdrawals, decreasing mean annual river flows from 2010 levels by 16% on average. However, increases in impervious cover by 2060 may offset the impact of climate change during the growing season in some watersheds. Large water withdrawals will aggravate the predicted impact of climate change on river flows, particularly in the Western US. Predicted ecohydrological impacts of land cover, water withdrawal, and climate change will likely include alteration of the terrestrial water balance, stream channel habitat, riparian and aquatic community structure in snow-dominated basins, and fish and mussel extirpations in heavily impacted watersheds. These changes may also require new infrastructure to support increasing anthropogenic demand for water

  10. Impacts of impervious cover, water withdrawals, and climate change on river flows in the conterminous US

    Directory of Open Access Journals (Sweden)

    P. V. Caldwell

    2012-08-01

    Full Text Available Rivers are essential to aquatic ecosystem and societal sustainability, but are increasingly impacted by water withdrawals, land-use change, and climate change. The relative and cumulative effects of these stressors on continental river flows are relatively unknown. In this study, we used an integrated water balance and flow routing model to evaluate the impacts of impervious cover and water withdrawal on river flow across the conterminous US at the 8-digit Hydrologic Unit Code (HUC watershed scale. We then estimated the impacts of projected change in withdrawals, impervious cover, and climate under the B1 "Low" and A2 "High" emission scenarios on river flows by 2060. Our results suggest that compared to no impervious cover, 2010 levels of impervious cover increased river flows by 9.9% on average with larger impacts in and downstream of major metropolitan areas. In contrast, compared to no water withdrawals, 2005 withdrawals decreased river flows by 1.4% on average with larger impacts in heavily irrigated arid regions of Western US. By 2060, impacts of climate change were predicted to overwhelm the potential gain in river flow due to future changes in impervious cover and add to the potential reduction in river flows from withdrawals, decreasing mean annual river flows from 2010 levels by 16% on average. However, increases in impervious cover by 2060 may offset the impact of climate change during the growing season in some watersheds. Large water withdrawals will aggravate the predicted impact of climate change on river flows, particularly in the Western US. Predicted ecohydrological impacts of land cover, water withdrawal, and climate change will likely include alteration of the terrestrial water balance, stream channel habitat, riparian and aquatic community structure in snow-dominated basins, and fish and mussel extirpations in heavily impacted watersheds. These changes may also require new infrastructure to support increasing anthropogenic

  11. Fluid flow separation in a reactor pressure vessel during an ECC injection. Single phase flow and two phase flow (air-water) experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Thierry Bichet; Alain Martin [EDF - Research and Development Division - Fluid Mechanics and Heat Transfert 6, quai Watier - B.P. 49 - 78401 Chatou CEDEX 01 (France); Frederic Beaud [EDF/ Industry - Basic Design Department., 12-14, Avenue Dutrievoz 69628 Villeurbanne CEDEX (France)

    2005-07-01

    Full text of publication follows: Within the framework of the nuclear power plant lifetime issue, the assessment of the French 900 MWe (3-loops) series reactor pressure vessel (RPV) integrity has been performed. A simplified analysis has shown that the most severe loading conditions are given by the small break loss of coolant accidents due to the pressurized injection of cold water (9 deg. C) into the cold leg and down comer of the RPV. During these transient scenarios, single or two-phase (uncovered cold leg) flows have been shown in the cold leg, depending on the crack size and RPV model (900 MWe or 1300 MWe). An experimental study has been carried out, on the one hand, to consolidate the numerical results obtained with CFD home code (Code-Saturne) which mainly showed the stratified flow in the cold leg and the fluid flow separation and its oscillations in the down comer during a single phase scenario. These physical phenomena are important for the thermal RPV loading assessment. On the other hand, the absence of experimental two-phase data necessitated to carry out an experimental study around the mixing area behavior (free surface, stratified flow) during an ECC injection with an uncovered cold leg. The new EDF R and D mock up, called HYBISCUS, is a facility which is made out of Plexiglas (atmosphere pressure) and represents a half scale CP0 geometry with one cold leg and part of the down comer. The mock up modularity allows us to insert representative ECC nozzles and a thermal shield. In reference to the reactor scenarios, the experimental operating conditions are derived from the conservation of the density effects (Froude number). For that, a heated salted water flow is used to represent the ECC injection whereas water represents the cold leg fluid. This mock up has been defined in order to represent single phase flow (cold leg and down comer full of water) or two-phase flow (uncovered cold leg) ECC scenarios. This paper reports experimental results

  12. Magnetic field-enhanced sedimentation of nanopowder magnetite in water flow.

    Science.gov (United States)

    Bakhteeva, Iu; Medvedeva, I; Byzov, I; Zhakov, S; Yermakov, A; Uimin, M; Shchegoleva, N

    2015-01-01

    Sedimentation dynamics of magnetite (γ-Fe3O4) nanopowder (10-20 nm) in water in a gradient magnetic field Bmax=0.3 T, (dB/dz)max=0.13 T/cm was studied for different water flow speeds and starting particle concentrations (0.1 and 1.0 g/l). The aggregates formation in water was monitored under the same conditions. In cyclical water flow, the velocity of particle sedimentation increases significantly in comparison to its rate in still water, which corresponds to the intensified aggregate formation. However, at a water flow speed more than 0.1 cm/s sedimentation velocity slows down, which might be connected to aggregate destruction in a faster water flow. Correlation between sedimentation time and the nanoparticle concentration in water does not follow the trend expected for spherical superparamagnetic particles. In our case sedimentation time is shorter for c=0.1 g/l in comparison with that for c=1 g/l. We submit that such a feature is caused by particle self-organization in water into complex structures of fractal type. This effect is unexplained in the framework of existing theoretical models of colloids systems, so far. Provisional recommendations are suggested for the design of a magnetic separator on the permanent magnets base. The main device parameters are magnetic field intensity B≥0.1 T, magnetic field gradient (dB/dz)max≈(0.1-0.2) T/cm, and water flow speed V<0.15 cm/s. For particle concentration c=1 g/l, purification of water from magnetite down to ecological and hygienic standards is reached in 80 min, for c=0.1 g/l the time is reduced down to 50 min.

  13. The representativeness of water samples from the outlet of flowing wells in an unconfined aquifer

    Science.gov (United States)

    Jiang, Xiao-Wei; Zhang, Zhi-Yuan; Wan, Li; Wang, Xu-Sheng; Wang, Jun-Zhi

    2017-04-01

    The representativeness of a groundwater sample is often confused by the mixture of groundwater from different depths of a well, especially when length of well screen is long. In a basin where groundwater flow is driven by topography, a well without casing could become a flowing well in topographic lows as long as the well is drilled deep enough. In this case, a water sample could be easily collected at the outlet of the flowing well without pumping. A recent field study in the Ordos basin shows that groundwater samples from the outlets of flowing wells with different depths differs greatly in chemical components. For the flowing wells penetrates to the deep part of the basin with depths ranging between 700 m and 970 m, it was found out that the concentrations of most chemical components of waters sampled at the outlets increases significantly with well depth. However, the hydraulic mechanism of the well depth-dependent hydrochemistry of mixed water sample is not clear. In this study, a 3-D unit basin expanded from Tóth's classic 2-D unit basin model was adopted to study the origin of water from different depths and the representativeness of water sampled at the outlet of a flowing well. The flowing well was modeled by the revised multi-node well (MNW2) Package in MODFLOW by setting a limit head equaling to the land surface and specifying an artificially high discharge rate. By considering well loss, we found the zone with development of flowing wells is smaller than the zone with positive values of head exceeding land surface. As long as the water table is a subdued replica of the land surface, the deep part of the flowing well receives discharge from the aquifer, while part of groundwater in the shallow part of the flowing well returns to the aquifer. The boundary between groundwater inflow and outflow is found to be sensitive to the ratio of water table to land surface, the distance away from the valley and the depth of the flowing well. In the segment of

  14. Mode pattern of internal flow in a water droplet on a vibrating hydrophobic surface.

    Science.gov (United States)

    Kim, Hun; Lim, Hee-Chang

    2015-06-04

    The objective of this study is to understand the mode pattern of the internal flow in a water droplet placed on a hydrophobic surface that periodically and vertically vibrates. As a result, a water droplet on a vibrating hydrophobic surface has a typical shape that depends on each resonance mode, and, additionally, we observed a diversified lobe size and internal flows in the water droplet. The size of each lobe at the resonance frequency was relatively greater than that at the neighboring frequencies, and the internal flow of the nth order mode was also observed in the flow visualization. In general, large symmetrical flow streams were generated along the vertical axis in each mode, with a large circulating movement from the bottom to the top, and then to the triple contact line along the droplet surface. In contrast, modes 2 and 4 generated a Y-shaped flow pattern, in which the flow moved to the node point in the lower part of the droplet, but modes 6 and 8 had similar patterns, with only a little difference. In addition, as a result of the PIV measurement, while the flow velocity of mode 4 was faster than that of model 2, those of modes 6 and 8 were almost similar.

  15. Modeling Flow Rate to Estimate Hydraulic Conductivity in a Parabolic Ceramic Water Filter

    Directory of Open Access Journals (Sweden)

    Ileana Wald

    2012-01-01

    Full Text Available In this project we model volumetric flow rate through a parabolic ceramic water filter (CWF to determine how quickly it can process water while still improving its quality. The volumetric flow rate is dependent upon the pore size of the filter, the surface area, and the height of water in the filter (hydraulic head. We derive differential equations governing this flow from the conservation of mass principle and Darcy's Law and find the flow rate with respect to time. We then use methods of calculus to find optimal specifications for the filter. This work is related to the research conducted in Dr. James R. Mihelcic's Civil and Environmental Engineering Lab at USF.

  16. Well balancing of the SWE schemes for moving-water steady flows

    Science.gov (United States)

    Caleffi, Valerio; Valiani, Alessandro

    2017-08-01

    In this work, the exact reproduction of a moving-water steady flow via the numerical solution of the one-dimensional shallow water equations is studied. A new scheme based on a modified version of the HLLEM approximate Riemann solver (Dumbser and Balsara (2016) [18]) that exactly preserves the total head and the discharge in the simulation of smooth steady flows and that correctly dissipates mechanical energy in the presence of hydraulic jumps is presented. This model is compared with a selected set of schemes from the literature, including models that exactly preserve quiescent flows and models that exactly preserve moving-water steady flows. The comparison highlights the strengths and weaknesses of the different approaches. In particular, the results show that the increase in accuracy in the steady state reproduction is counterbalanced by a reduced robustness and numerical efficiency of the models. Some solutions to reduce these drawbacks, at the cost of increased algorithm complexity, are presented.

  17. Simulation of the solidification in a channel of a water-cooled glass flow

    Directory of Open Access Journals (Sweden)

    G. E. Ovando Chacon

    2014-12-01

    Full Text Available A computer simulation study of a laminar steady-state glass flow that exits from a channel cooled with water is reported. The simulations are carried out in a two-dimensional, Cartesian channel with a backward-facing step for three different angles of the step and different glass outflow velocities. We studied the interaction of the fluid dynamics, phase change and thermal behavior of the glass flow due to the heat that transfers to the cooling water through the wall of the channel. The temperature, streamline, phase change and pressure fields are obtained and analyzed for the glass flow. Moreover, the temperature increments of the cooling water are characterized. It is shown that, by reducing the glass outflow velocity, the solidification is enhanced; meanwhile, an increase of the step angle also improves the solidification of the glass flow.

  18. Amsterdam as a Sustainable European Metropolis : Integration of Water, Energy and Material Flows

    NARCIS (Netherlands)

    Van Der Hoek, J.P.; Struker, A.; Danschutter, J.E.M.

    2013-01-01

    Amsterdam has the ambition to develop as a competitive and sustainable European metropolis. The flows of energy, water and resources within the urban environment have a large potential to contribute to this ambition. The overall mass balances of phosphate, food, water, energy and material imports in

  19. Optimization of ships in shallow water with viscous flow computations and surrogate modeling

    NARCIS (Netherlands)

    Rotteveel, E.; van der Ploeg, A; Hekkenberg, R.G.; Nielsen, U.D.; Jensen et al, J.J.

    2016-01-01

    Shallow water effects change the flow around a ship significantly which can affect the optimum design of the hull. This paper describes a study into the optimization of the aft ship region for various water depths. The research focuses on variations of the following parameters of a hull form: The

  20. CFD Study of Fluid Flow in an All-glass Evacuated Tube Solar Water Heater

    DEFF Research Database (Denmark)

    Ai, Ning; Fan, Jianhua; Li, Yumin

    2008-01-01

    Abstract: The all-glass evacuated tube solar water heater is one of the most widely used solar thermal technologies. The aim of the paper is to investigate fluid flow in the solar water heater by means of computational fluid dynamics (CFD). The investigation was carried out with a focus...

  1. Interfacial wave behavior in oil-water channel flows: Prospects for a general understanding

    Energy Technology Data Exchange (ETDEWEB)

    McCready, M.J.; Uphold, D.D.; Gifford, K.A. [Univ. of Notre Dame, IN (United States)

    1997-12-31

    Oil-water pressure driven channel flow is examined as a model for general two-layer flows where interfacial disturbances are important. The goal is to develop sufficient understanding of this system so that the utility and limitations of linear and nonlinear theories can be known a priori. Experiments show that sometimes linear stability is useful at predicting the steady or dominant evolving waves. However in other situations there is no agreement between the linearly fastest growing wave and the spectral peak. An interesting preliminary result is that the bifurcation to interfacial waves is supercritical for all conditions that were studied for an oil-water channel flow, gas-liquid channel flow and two-liquid Couette flow. However, three different mechanisms are dominant for each of these three situations.

  2. Water and mass budgets of a vertical-flow constructed wetland used for wastewater treatment

    NARCIS (Netherlands)

    Meuleman, Arthur F M; Van Logtestijn, Richard; Rijs, Gerard B J; Verhoeven, Jos T A

    To estimate the nutrient and organic matter (Biological Oxygen Demand (BODs) and Chemical Oxygen Demand (COD)) removal capacity of a constructed vertical-flow wetland in The Netherlands, a water and nutrient budget study was conducted. Also bacterial water quality enhancement was measured. The

  3. Numerical modeling of coupled water flow and heat transport in soil and snow

    Science.gov (United States)

    Thijs J. Kelleners; Jeremy Koonce; Rose Shillito; Jelle Dijkema; Markus Berli; Michael H. Young; John M. Frank; William Massman

    2016-01-01

    A one-dimensional vertical numerical model for coupled water flow and heat transport in soil and snow was modified to include all three phases of water: vapor, liquid, and ice. The top boundary condition in the model is driven by incoming precipitation and the surface energy balance. The model was applied to three different terrestrial systems: A warm desert bare...

  4. Influence of sampling strategy on detecting preferential flow paths in water-repellent sand

    NARCIS (Netherlands)

    Ritsema, C.J.; Dekker, L.W.

    1996-01-01

    A sample spacing up to 22 cm over a distance of several metres is just sufficient to collect information about preferential flow paths in a water-repellent sandy soil. When larger sample spacings were used, the water content distributions became more horizontally stratified. Increasing the sample

  5. Interrelationships of petiole air canal architecture, water depth and convective air flow in Nymphaea odorata (Nymphaeaceae)

    Science.gov (United States)

    Premise of the study--Nymphaea odorata grows in water up to 2 m deep, producing fewer, larger leaves in deeper water. This species has a convective flow system that moves gases from younger leaves through submerged parts to older leaves, aerating submerged parts. Petiole air canals are in the conv...

  6. The influence of water flow (reversal) on bond strength development in young masonry

    NARCIS (Netherlands)

    Groot, C.; Larbi, J.

    1999-01-01

    Water loss from the fresh mortar is believed to be related to mortar-brick bond strength development in masonry. Recent research on mortar-brick bond has shown that, particularly, effects of water flow on the composition and the hydration conditions of the mortar-brick interface have to be taken

  7. Within plant resistance to water flow in tomato and sweet melons ...

    African Journals Online (AJOL)

    In the evaporative flux method, measurements of transpiration flux and leaf water potential were used to calculate the total resistance to water flow using Ohm's law analogy. Measurements of tranpiration flux (Q) relationship, plant resistance calculated from the slope of their relationship, ranged from 6.57x10-01 to ...

  8. Uncertainty in Multimodel Water Flow Simulation Associated with Pedotransfer Functions and Weighing Methods

    Science.gov (United States)

    Multimodeling (MM) has been developed during the last decade to improve prediction capability of hydrological models. The MM combined with the pedotransfer functions (PTFs) was successfully applied to soil water flow simulations. This study examined the uncertainty in water content simulations assoc...

  9. Water pumping and analysis of flow in burrowing zoobenthos - a short overview

    DEFF Research Database (Denmark)

    Riisgård, H. U.; Larsen, Poul Scheel

    2002-01-01

    Measurement of water pumping rates of burrowing animals is of crucial importance for the study of many processes both within and above the sea floor. This short review deals with water pumping and analysis of flow, including available techniques and bio-fluid mechanical theory, in burrowing deposit...

  10. Evaluation of 2D shallow-water model for spillway flow with a complex geometry

    Science.gov (United States)

    Although the two-dimensional (2D) shallow water model is formulated based on several assumptions such as hydrostatic pressure distribution and vertical velocity is negligible, as a simple alternative to the complex 3D model, it has been used to compute water flows in which these assumptions may be ...

  11. Farm level optimal water management : assistant for irrigation under deficit (FLOW-AID)

    NARCIS (Netherlands)

    Balendonck, J.; Stanghellini, C.; Hemming, J.; Kempkes, F.L.K.; Tuijl, van B.A.J.

    2008-01-01

    FLOW-AID is an on-going 6th Framework European project (2006-2009) with the objective to contribute to sustainable irrigated agriculture by developing an irrigation management system that can be used for crop production in cases with limited water supply and marginal water quality. The project

  12. Farm level optimal water management: Assistant for irrigation under Defecit (FLOW-AID)

    NARCIS (Netherlands)

    Balendonck, J.; Stanghellini, C.; Hemming, J.; Kempkes, F.L.K.; Tuijl, van B.A.J.

    2009-01-01

    Flow-aid is an on-going 6th Framework European project (2006-2009) with the objective to contribute to sustainable irrigated agriculture by developing an irrigation management system that can be used for crop production in cases with limited water supply and marginal water quality. The project

  13. Hydrology and simulation of ground-water flow in Kamas Valley, Summit County, Utah

    Science.gov (United States)

    Brooks, L.E.; Stolp, B.J.; Spangler, L.E.

    2003-01-01

    Kamas Valley, Utah, is located about 50 miles east of Salt Lake City and is undergoing residential development. The increasing number of wells and septic systems raised concerns of water managers and prompted this hydrologic study. About 350,000 acre-feet per year of surface water flows through Kamas Valley in the Weber River, Beaver Creek, and Provo River, which originate in the Uinta Mountains east of the study area. The ground-water system in this area consists of water in unconsolidated deposits and consolidated rock; water budgets indicate very little interaction between consolidated rock and unconsolidated deposits. Most recharge to consolidated rock occurs at higher altitudes in the mountains and discharges to streams and springs upgradient of Kamas Valley. About 38,000 acre-feet per year of water flows through the unconsolidated deposits in Kamas Valley. Most recharge is from irrigation and seepage from major streams; most discharge is to Beaver Creek in the middle part of the valley. Long-term water-level fluctuations range from about 3 to 17 feet. Seasonal fluctuations exceed 50 feet. Transmissivity varies over four orders of magnitude in both the unconsolidated deposits and consolidated rock and is typically 1,000 to 10,000 feet squared per day in unconsolidated deposits and 100 feet squared per day in consolidated rock as determined from specific capacity. Water samples collected from wells, streams, and springs had nitrate plus nitrite concentrations (as N) substantially less than 10 mg/L. Total and fecal coliform bacteria were detected in some surface-water samples and probably originate from livestock. Septic systems do not appear to be degrading water quality. A numerical ground-water flow model developed to test the conceptual understanding of the ground-water system adequately simulates water levels and flow in the unconsolidated deposits. Analyses of model fit and sensitivity were used to refine the conceptual and numerical models.

  14. Towards a comprehensive assessment and framework for low and high flow water risks

    Science.gov (United States)

    Motschmann, Alina; Huggel, Christian; Drenkhan, Fabian; León, Christian

    2017-04-01

    Driven by international organizations such as the Intergovernmental Panel on Climate Change (IPCC) the past years have seen a move from a vulnerability concept of climate change impacts towards a risk framework. Risk is now conceived at the intersection of climate-driven hazard and socioeconomic-driven vulnerability and exposure. The concept of risk so far has been mainly adopted for sudden-onset events. However, for slow-onset and cumulative climate change impacts such as changing water resources there is missing clarity and experience how to apply a risk framework. Research has hardly dealt with the challenge of how to integrate both low and high flow risks in a common framework. Comprehensive analyses of risks related to water resources considering climate change within multi-dimensional drivers across different scales are complex and often missing in climate-sensitive mountain regions where data scarcity and inconsistencies represent important limitations. Here we review existing vulnerability and risk assessments of low and high flow water conditions and identify critical conceptual and practical gaps. Based on this, we develop an integrated framework for low and high flow water risks which is applicable to both past and future conditions. The framework explicitly considers a water balance model simulating both water supply and demand on a daily basis. We test and apply this new framework in the highly glacierized Santa River catchment (SRC, Cordillera Blanca, Peru), representative for many developing mountain regions with both low and high flow water risks and poor data availability. In fact, in the SRC, both low and high flow hazards, such as droughts and floods, play a central role especially for agricultural, hydropower, domestic and mining use. During the dry season (austral winter) people are increasingly affected by water scarcity due to shrinking glaciers supplying melt water. On the other hand during the wet season (austral summer) high flow water

  15. Application of Tank Model for Predicting Water Balance and Flow Discharge Components of Cisadane Upper Catchment

    Directory of Open Access Journals (Sweden)

    Nana Mulyana Arifjaya

    2012-01-01

    Full Text Available The concept of hydrological tank model was well described into four compartments (tanks. The first tank (tank A comprised of one vertical (qA0 and two lateral (qA1 and qA2 water flow components and tank B comprised of one vertical (qB0 and one lateral (qB1 water flow components. Tank C comprised of one vertical (qC0 and one lateral (qC1 water flow components, whereas tank D comprised of one lateral water flow component (qD1.  These vertical water flows would also contribute to the depletion of water flow in the related tanks but would replenish tanks in the deeper layers. It was assumed that at all lateral water flow components would finally accumulate in one stream, summing-up of the lateral water flow, much or less, should be equal to the water discharge (Qo at specified time concerns. Tank A received precipitation (R and evapo-transpiration (ET which was its gradientof (R-ET over time would become the driving force for the changes of water stored in the soil profiles and thosewater flows leaving the soil layer.  Thus tank model could describe th vertical and horizontal water flow withinthe watershed. The research site was Cisadane Upper Catchment, located at Pasir Buncir Village of CaringinSub-District within the Regency of Bogor in West Java Province.  The elevations ranged 512 –2,235 m above sealevel, with a total drainage area of 1,811.5 ha and total length of main stream of 14,340.7 m.  The land cover wasdominated by  forest  with a total of 1,044.6 ha (57.67%,  upland agriculture with a total of 477.96 ha (26.38%,mixed garden with a total of 92.85 ha(5.13% and semitechnical irigated rice field with a total of 196.09 ha (10,8%.  The soil was classified as hydraquent (96.6% and distropept (3.4%.  Based on the calibration of tank model application in the study area, the resulting coefficient of determination (R2 was 0.72 with model efficiency (NSEof= 0.75, thus tank model could well illustrate the water flow distribution of

  16. Effect of air on water capillary flow in silica nanochannels

    DEFF Research Database (Denmark)

    Zambrano, Harvey; Walther, Jens Honore; Oyarzua, Elton

    2013-01-01

    in sub 10 nm silica channels. The capillary filling speed is computed in channels subjected to different air pressures. In order to describe the interactions between the species, an effective force field is developed, which is calibrated by reproducing the water contact angle. The results show...... that the capillary filling speed qualitatively follows the classical Washburn model, however, quantitatively it is lower than expected. Furthermore, it is observed that the deviations increase as air pressure is higher. We attribute the deviations to amounts of air trapped at the silica-water interface which leads...

  17. Optimality and Conductivity for Water Flow: From Landscapes, to Unsaturated Soils, to Plant Leaves

    Energy Technology Data Exchange (ETDEWEB)

    Liu, H.H.

    2012-02-23

    Optimality principles have been widely used in many areas. Based on an optimality principle that any flow field will tend toward a minimum in the energy dissipation rate, this work shows that there exists a unified form of conductivity relationship for three different flow systems: landscapes, unsaturated soils and plant leaves. The conductivity, the ratio of water flux to energy gradient, is a power function of water flux although the power value is system dependent. This relationship indicates that to minimize energy dissipation rate for a whole system, water flow has a small resistance (or a large conductivity) at a location of large water flux. Empirical evidence supports validity of the relationship for landscape and unsaturated soils (under gravity dominated conditions). Numerical simulation results also show that the relationship can capture the key features of hydraulic structure for a plant leaf, although more studies are needed to further confirm its validity. Especially, it is of interest that according to this relationship, hydraulic conductivity for gravity-dominated unsaturated flow, unlike that defined in the classic theories, depends on not only capillary pressure (or saturation), but also the water flux. Use of the optimality principle allows for determining useful results that are applicable to a broad range of areas involving highly non-linear processes and may not be possible to obtain from classic theories describing water flow processes.

  18. Effect of stone content on water flow velocity over Loess slope: Frozen soil

    Science.gov (United States)

    Ban, Yunyun; Lei, Tingwu; Feng, Ren; Qian, Dengfeng

    2017-11-01

    Soils in high-altitude or -latitude regions are commonly rich in stone fragments, which are frequently frozen. The hydrodynamics of water flow over frozen, stony slopes must be investigated to understand soil erosion and sediment transportation. The objective of this laboratory experiments was to measure water flow velocity over frozen slopes with different stone contents by using electrolyte trace method. The experiments were performed under slope gradients of 5°, 10°, 15°, and 20°; flow discharge rates of 1, 2, 4, and 8 L/min; and stone contents of 0%, 10%, 20%, and 50% on mass basis. Nine equidistant sensors were used to measure flow velocity along flume from the top of the slope. Results indicated that stone content significantly affected flow velocity under increasing slope gradient. The increase in stone content rapidly reduced the flow velocity. The flow velocities over frozen slopes were 1.21 to 1.30 times of those over non-frozen slopes under different slope gradients and flow rates. When the stone content increased from 0% to 20%, proportions gradually decreased from 52% to 25% and 13%. Additionally, flow velocities over frozen and non-frozen soil slopes became gradually similar with increasing stone content. This study will help elucidate the hydrodynamics, soil erosion, and sediment transport behaviors of frozen or partially unfrozen hillslopes with different stone contents.

  19. Fluid flow and heat transfer in an air-to-water double-pipe heat exchanger

    Science.gov (United States)

    Sheikholeslami, M.; Gorji-Bandpy, M.; Ganji, D. D.

    2015-11-01

    This paper reports experimental and numerical investigations on flow and heat transfer in an air-to-water double-pipe heat exchanger. The working fluids are air and water. To achieve fully developed conditions, the heat exchanger was built with additional lengths before and after the test section. The inner and outer tube was made from copper and Plexiglas, respectively. The experiments are conducted in the range of air flow Reynolds number for various cases with different water flow rate and water inlet temperature. Correlations for the Nusselt number and friction factor are presented according to experimental data. Also the commercial code ANSYS 15 is used for numerical simulation. Results show that the Nusselt number is an increasing function of Reynolds number and Prandtl number which are calculated at bulk temperature.

  20. The Research on Metrological Characteristics of House Water Meters during Transitional Flow Regimes

    Directory of Open Access Journals (Sweden)

    Inga Briliūtė

    2011-04-01

    Full Text Available The purpose of this research is to find the influence of transitional flow regimes on inlet water meters. Four construction types of mechanical inlet water meters (each capacity Q = 10 m3/h were investigated. The biggest additional volume 0,12–0,26% when Q = 0,2…2 m3/h shows single-jet vane wheel meter. This additional volume is less 0,06–0,13% for the multi-jet concentric water meter. The minimum influence of transitional flow regimes was for turbine water meters till 0,1% for all flow range. The volumetric meters are not sensitive for this effect.Article in Lithuanian

  1. Modelling flow dynamics in water distribution networks using ...

    African Journals Online (AJOL)

    Computational approaches can be used to detect leakages in water distribution networks. One such approach is the Artificial Neural Networks (ANNs) technique. The advantage of ANNs is that they are robust and can be used to model complex linear and non-linear systems without making implicit assumptions. ANNs can ...

  2. two - dimensional mathematical model of water flow in open

    African Journals Online (AJOL)

    ES Obe

    1996-09-01

    Sep 1, 1996 ... simplification of the system of the governing shallow water equations and the final nonlinear differential equation is solved for the unknown energy head using the finite element method. A one - dimensional problem was solved with diffusion hydraulic model (DHM), energy diffusion hydraulic model (EDHM) ...

  3. Water flow and nitrate leaching in a layered silt loam

    NARCIS (Netherlands)

    Vos, J.A.; Hesterberg, D.L.R.; Raats, P.A.C.

    2000-01-01

    Nitrate (NO3) leaching was studied for a winter leaching period in a layered calcareous silt loam with tile-drains at about 1-m depth and 12-m spacing. Groundwater levels, drain discharge rates, and NO3 concentrations in the drainage water were monitored, and the soil hydraulic characteristics were

  4. Comments on: A flow balance approach to scenarios for water ...

    African Journals Online (AJOL)

    drinie

    I would like to offer a brief comment on the above paper, which appeared in Water SA 25 (4), October 1999. Reuse of treated sewage effluent is essential to the survival of this country and this paper correctly highlights that this important resource is not being optimally used. I am concerned though that the research ...

  5. Early Regimes of Water Capillary Flow in Slit Silica Nanochannels

    DEFF Research Database (Denmark)

    Oyarzua, Elton; Walther, Jens Honore; Mejia, Andres

    2015-01-01

    Molecular dynamics simulations are conducted to investigate the initial stages of spontaneous imbibitionof water in slit silica nanochannels surrounded by air. An analysis is performed for the effects of nanoscopicconfinement, initial conditions of liquid uptake and air pressurization on the dyna...

  6. simulation of vertical water flow through vadose zone

    African Journals Online (AJOL)

    HOD

    hydrological cycle because it holds only a minute fraction of the earth's fresh water as investigated by. [1]. Vadose ... within this zone has applications in fields of hydrology, agriculture and soil engineering [2] and is critical to ... The vegetation cover is Sudan Savannah type, characterized by scattered short trees, shrubs and.

  7. Normalization of water flow rate for external fire fighting of the buildings in settlements with zone water supply

    Directory of Open Access Journals (Sweden)

    Deryushev Leonid Georgievich

    2014-12-01

    Full Text Available In the article the requirements for fire safety assurance are justified for the objects, in which water is supplied with account for serial and parallel area zoning. In the process of zoning the district is segregated into such parts, for which head rate in any point of selection of water from network will not exceed 6 bar. In the current regulatory rules the requirements for the calculation of the costs of water points are stated, as well as in case of extinguishing fires at the sites with water-supply systems zones. It is recommended to analyze each zone of the system of water-supply separately, without interrelation with the common water feeders, water consumers and services of fire extinguishing. Such an approach to assign water discharge for fire extinguishing results in the decrease of fire safety of an object, deforms calculation technique of outside systems of water-supply of the similar-type objects located in different parts of the terrain. Taking the number of fires and water consumption for fire suppression by the number of residents in each zone, we thus underestimate the capacity of the pipeline system. It is offered to make changes in Norms and Standards in force on fire safety of settlements. The recommendations on regulation of the number of fires and water flow for fire fighting in residential objects with zoned systems of water-supply are formulated.

  8. Quantitative neutron imaging of water distribution, venation network and sap flow in leaves.

    Science.gov (United States)

    Defraeye, Thijs; Derome, Dominique; Aregawi, Wondwosen; Cantré, Dennis; Hartmann, Stefan; Lehmann, Eberhard; Carmeliet, Jan; Voisard, Frédéric; Verboven, Pieter; Nicolai, Bart

    2014-08-01

    Quantitative neutron imaging is a promising technique to investigate leaf water flow and transpiration in real time and has perspectives towards studies of plant response to environmental conditions and plant water stress. The leaf hydraulic architecture is a key determinant of plant sap transport and plant-atmosphere exchange processes. Non-destructive imaging with neutrons shows large potential for unveiling the complex internal features of the venation network and the transport therein. However, it was only used for two-dimensional imaging without addressing flow dynamics and was still unsuccessful in accurate quantification of the amount of water. Quantitative neutron imaging was used to investigate, for the first time, the water distribution in veins and lamina, the three-dimensional venation architecture and sap flow dynamics in leaves. The latter was visualised using D2O as a contrast liquid. A high dynamic resolution was obtained by using cold neutrons and imaging relied on radiography (2D) as well as tomography (3D). The principle of the technique was shown for detached leaves, but can be applied to in vivo leaves as well. The venation network architecture and the water distribution in the veins and lamina unveiled clear differences between plant species. The leaf water content could be successfully quantified, though still included the contribution of the leaf dry matter. The flow measurements exposed the hierarchical structure of the water transport pathways, and an accurate quantification of the absolute amount of water uptake in the leaf was possible. Particular advantages of neutron imaging, as compared to X-ray imaging, were identified. Quantitative neutron imaging is a promising technique to investigate leaf water flow and transpiration in real time and has perspectives towards studies of plant response to environmental conditions and plant water stress.

  9. Surface-flow wetland for water reclamation at Batamindo Industrial Park

    OpenAIRE

    Salim Chris; Rachmania Andita; Dewi Rahma

    2017-01-01

    The reclamation of wastewater as clean water resource is essential in the concept of water conservation. In industries, this will also lead to overall plant operational cost reduction. In this study, a pilot-scale surface-flow constructed wetland system filled with water hyacinth was used to treat effluent from existing sewage treatment plant at Batamindo Industrial Park. The sewage treatment plant effluent with quality fulfilling the regulation of Indonesian Ministry of Environment No.5/2014...

  10. Hydrogeology and simulation of ground-water flow in the Sandstone Aquifer, northeastern Wisconsin

    Science.gov (United States)

    Conlon, T.D.

    1998-01-01

    Municipalities in the lower Fox River Valley in northeastern Wisconsin obtain their water supply from a series of permeable sandstones and carbonates of Cambrian to Ordovician age. Withdrawals from this "sandstone aquifer" have resulted in water levels declining at a rate of more than 2 feet per year. The U.S. Geological Survey, in cooperation with the major water utilities in the Fox Cities area, the East Central Wisconsin Regional Planning Commission and the Wisconsin Geological and Natural History Survey, collected hydrogeological data and constructed a quasithree- dimensional, transient ground-water-flow model for use as a tool in assessing the water resources of the sandstone aquifer.

  11. Hydrogeology and simulation of ground-water flow near the Lantana Landfill, Palm Beach County, Florida

    Science.gov (United States)

    Russell, G.M.; Wexler, E.J.

    1993-01-01

    The Lantana landfill in Palm Beach County has a surface that is 40 to 50 feet above original ground level and consists of about 250 acres of compacted garbage and trash. Parts of the landfill are below the water table. Surface-resistivity measurements and water-quality analyses indicate that leachate-enriched ground water along the eastern perimeter of the landfill has moved about 500 feet eastward toward an adjacent lake. Concentrations of chloride and nutrients within the leachate-enriched ground water were greater than background concentrations. The surficial aquifer system in the area of the landfill consists primarily of sand of moderate permeability, from land surface to a depth of about 68 feet deep, and consists of sand interbedded with sandstone and limestone of high permeability from a depth of about 68 feet to a depth of 200 feet. The potentiometric surface in the landfill is higher than that in adjacent areas to the east, indicating ground-water movement from the landfill toward a lake to the east. Steady-state simulation of ground-water flow was made using a telescoping-grid technique where a model covering a large area is used to determine boundaries and fluxes for a finer scale model. A regional flow model encompassing a 500-square mile area in southeastern Palm Beach County was used to calculate ground-water fluxes in a 126.5-square mile subregional area. Boundary fluxes calculated by the subregional model were then used to calculate boundary fluxes for a local model of the 3.75-square mile area representing the Lantana landfill site and vicinity. Input data required for simulating ground-water flow in the study area were obtained from the regional flow models, thus, effectively coupling the models. Additional simulations were made using the local flow model to predict effects of possible remedial actions on the movement of solutes in the ground-water system. Possible remedial actions simulated included capping the landfill with an impermeable layer

  12. Flow paths of water and sediment in a tidal marsh: relations with marsh developmental stage and tidal inundation height

    NARCIS (Netherlands)

    Temmerman, S.; Bouma, T.J.; Govers, G.; Lauwaet, D.

    2005-01-01

    This study provides new insights in the relative role of tidal creeks and the marsh edge in supplying water and sediments to and from tidal marshes for a wide range of tidal inundation cycles with different high water levels and for marsh zones of different developmental stage. Net import or export

  13. Complexity Metrics for Workflow Nets

    DEFF Research Database (Denmark)

    Lassen, Kristian Bisgaard; van der Aalst, Wil M.P.

    2009-01-01

    Process modeling languages such as EPCs, BPMN, flow charts, UML activity diagrams, Petri nets, etc.\\ are used to model business processes and to configure process-aware information systems. It is known that users have problems understanding these diagrams. In fact, even process engineers and system...

  14. Interrelationships of petiolar air canal architecture, water depth, and convective air flow in Nymphaea odorata (Nymphaeaceae).

    Science.gov (United States)

    Richards, Jennifer H; Kuhn, David N; Bishop, Kristin

    2012-12-01

    Nymphaea odorata grows in water up to 2 m deep, producing fewer larger leaves in deeper water. This species has a convective flow system that moves gases from younger leaves through submerged parts to older leaves, aerating submerged parts. Petiolar air canals are the convective flow pathways. This study describes the structure of these canals, how this structure varies with water depth, and models how convective flow varies with depth. • Nymphaea odorata plants were grown at water depths from 30 to 90 cm. Lamina area, petiolar cross-sectional area, and number and area of air canals were measured. Field-collected leaves and leaves from juvenile plants were analyzed similarly. Using these data and data from the literature, we modeled how convective flow changes with water depth. • Petioles of N. odorata produce two central pairs of air canals; additional pairs are added peripherally, and succeeding pairs are smaller. The first three pairs account for 96% of air canal area. Air canals form 24% of petiolar cross-sectional area. Petiolar and air canal cross-sectional areas increase with water depth. Petiolar area scales with lamina area, but the slope of this relationship is lower in 90 cm water than at shallower depths. In our model, the rate of convective flow varied with depth and with the balance of influx to efflux leaves. • Air canals in N. odorata petioles increase in size and number in deeper water but at a decreasing amount in relation to lamina area. Convective flow also depends on the number of influx to efflux laminae.

  15. Measurement of Vapor Flow As an Important Source of Water in Dry Land Eco-Hydrology

    Science.gov (United States)

    Wang, Z.; He, Z.; Wang, Y.; Gao, Z.; Hishida, K.

    2014-12-01

    When the temperature of land surface is lower than that of air and deeper soils, water vapor gathers toward the ground surface where dew maybe formed depending on the prevailing dew point and wind speed. Some plants are able to absorb the dew and vapor flow while the soil can readily absorb both. Certain animals such as desert beetles and ants harvest the dew or fog for daily survival. Recently, it is also realized that the dew and vapor flow can be a life-saving amount of water for plant survival at the driest seasons of the year in arid and semi-arid regions. Researches are conducted to quantify the amount of near-surface vapor flow in arid and semi-arid regions in China and USA. Quantitative leaf water absorption and desorption functions were derived based on laboratory experiments. Results show that plant leaves absorb and release water at different speeds depending on species and varieties. The "ideal" native plants in the dry climates can quickly absorb water and slowly release it. This water-holding capacity of plant is characterized by the absorption and desorption functions derived for plant physiology and water balance studies. Field studies are conducted to measure the dynamic vapor flow movements from the atmosphere and the groundwater table to soil surface. Results show that dew is usually formed on soil and plant surfaces during the daily hours when the temperature gradients are inverted toward the soil surface. The amount of dew harvested using gravels on the soil surface was enough to support water melon agriculture on deserts. The vapor flow can be effectively intercepted by artificially seeded plants in semi-arid regions forming new forests. New studies are attempted to quantify the role of vapor flow for the survival of giant sequoias in the southern Sierra Nevada Mountains of California.

  16. The Finite Element Analysis for a Mini-Conductance Probe in Horizontal Oil-Water Two-Phase Flow

    Directory of Open Access Journals (Sweden)

    Weihang Kong

    2016-08-01

    Full Text Available Oil-water two-phase flow is widespread in petroleum industry processes. The study of oil-water two-phase flow in horizontal pipes and the liquid holdup measurement of oil-water two-phase flow are of great importance for the optimization of the oil production process. This paper presents a novel sensor, i.e., a mini-conductance probe (MCP for measuring pure-water phase conductivity of oil-water segregated flow in horizontal pipes. The MCP solves the difficult problem of obtaining the pure-water correction for water holdup measurements by using a ring-shaped conductivity water-cut meter (RSCWCM. Firstly, using the finite element method (FEM, the spatial sensitivity field of the MCP is investigated and the optimized MCP geometry structure is determined in terms of the characteristic parameters. Then, the responses of the MCP for the oil-water segregated flow are calculated, and it is found that the MCP has better stability and sensitivity to the variation of water-layer thickness in the condition of high water holdup and low flow velocity. Finally, the static experiments for the oil-water segregated flow were carried out and a novel calibration method for pure-water phase conductivity measurements was presented. The validity of the pure-water phase conductivity measurement with segregated flow in horizontal pipes was verified by experimental results.

  17. Dynamic features of bubble induced by a nanosecond pulse laser in still and flowing water

    Science.gov (United States)

    Charee, Wisan; Tangwarodomnukun, Viboon

    2018-03-01

    Underwater laser ablation techniques have been developed and employed to synthesis nanoparticles, to texture workpiece surface and to assist the material removal in laser machining process. However, the understanding of laser-material-water interactions, bubble formation and effects of water flow on ablation performance has still been very limited. This paper thus aims at exploring the formation and collapse of bubbles during the laser ablation of silicon in water. The effects of water flow rate on bubble formation and its consequences to the laser disturbance and cut features obtained in silicon were observed by using a high speed camera. A nanosecond pulse laser emitting the laser pulse energy of 0.2-0.5 mJ was employed in the experiment. The results showed that the bubble size was found to increase with the laser pulse energy. The use of high water flow rate can importantly facilitate the ejection of ablated particles from the workpiece surface, hence resulting in less deposition to the work surface and minimizing any disturbance to the laser beam during the ablation in water. Furthermore, a clean micro-groove in silicon wafer can successfully be produced when the process was performed in the high water flow rate condition. The findings of this study could provide an essential guideline for process selection, control and improvement in the laser micro-/submicro-fabrication using the underwater technique.

  18. Flow resistance reduction of coal water slurry through gas phase addition

    Directory of Open Access Journals (Sweden)

    Robak Jolanta

    2016-01-01

    Full Text Available One of the main advantages of coal water slurry fuel (CWS is a physical form that allows, among others, their transfer by pipelines over long distances. For this form of transport actions towards reducing the flow resistance of the transmitted medium are important. One of the treatments leading to reduction in the flow resistance of suspensions is to introduce gas into the stream of flowing slurry. The goal of that action is to either loosen the structure of densely packed grains or increase the velocity of the suspension. The paper presents the flow resistance of CWS in a horizontal pipeline and the effect of addition of the gas phase on the resistance level. The investigation was carried out with the use of a research stand enabling to measure the flow resistance of the multiphase/multicomponent systems. The measured diameter and length of sections were respectively: 0.03 and 2 m. The coal-water slurries (based on steam coals with concentration of dry coal in the range of 51 do 60% obtained by wet milling in a drum mill were used. During the tests, the following parameters were measured: slurry flow rate, air flow rate, temperature and pressure difference in inlet and outlet of the measured section. The volume flow rate of slurry fuel was in the range of 30 to 110 dm3/min while the volume flow rate of air was from 0.15 to 4 m3/h. Based on the obtained results, the slurry flow resistance as a function of the flow rate and share of introduced air was evaluated. The performed research allowed for assessment of flow resistance reduction condition and to determine the pipe flow curves for different temperatures. It was found that the effect of reducing the flow resistance of the coal slurry by introducing gas into the flow tube depended on the volumetric flow rate, and thus the linear velocity of the slurry. Under the experimental condition, this effect only occurred at low flow rates (30 - 50 dm3/min and low temperature of the suspension. The

  19. A coupled surface-water and ground-water flow model (MODBRANCH) for simulation of stream-aquifer interaction

    Science.gov (United States)

    Swain, Eric D.; Wexler, Eliezer J.

    1996-01-01

    Ground-water and surface-water flow models traditionally have been developed separately, with interaction between subsurface flow and streamflow either not simulated at all or accounted for by simple formulations. In areas with dynamic and hydraulically well-connected ground-water and surface-water systems, stream-aquifer interaction should be simulated using deterministic responses of both systems coupled at the stream-aquifer interface. Accordingly, a new coupled ground-water and surface-water model was developed by combining the U.S. Geological Survey models MODFLOW and BRANCH; the interfacing code is referred to as MODBRANCH. MODFLOW is the widely used modular three-dimensional, finite-difference ground-water model, and BRANCH is a one-dimensional numerical model commonly used to simulate unsteady flow in open- channel networks. MODFLOW was originally written with the River package, which calculates leakage between the aquifer and stream, assuming that the stream's stage remains constant during one model stress period. A simple streamflow routing model has been added to MODFLOW, but is limited to steady flow in rectangular, prismatic channels. To overcome these limitations, the BRANCH model, which simulates unsteady, nonuniform flow by solving the St. Venant equations, was restructured and incorporated into MODFLOW. Terms that describe leakage between stream and aquifer as a function of streambed conductance and differences in aquifer and stream stage were added to the continuity equation in BRANCH. Thus, leakage between the aquifer and stream can be calculated separately in each model, or leakages calculated in BRANCH can be used in MODFLOW. Total mass in the coupled models is accounted for and conserved. The BRANCH model calculates new stream stages for each time interval in a transient simulation based on upstream boundary conditions, stream properties, and initial estimates of aquifer heads. Next, aquifer heads are calculated in MODFLOW based on stream

  20. Measurement of vertical oil-in-water two-phase flow using dual-modality ERT–EMF system

    OpenAIRE

    Faraj, Yousef; Wang, Mi; Jia, Jiabin; Wang, Qiang; Xie, Cheng-gang; Oddie, Gary; Primrose, Ken; Qiu, Changhua

    2015-01-01

    Oil-in-water two-phase flows are often encountered in the upstream petroleum industry. The measurement of phase flow rates is of particular importance for managing oil production and water disposal and/or water reinjection. The complexity of oil-in-water flow structures creates a challenge to flow measurement. This paper proposes a new method of two-phase flow metering, which is based on the use of dual-modality system and multidimensional data fusion. The Electrical Resistance Tomography sys...

  1. Detection of artificial water flows by the lateral line system of a benthic feeding cichlid fish.

    Science.gov (United States)

    Schwalbe, Margot A B; Sevey, Benjamin J; Webb, Jacqueline F

    2016-04-01

    The mechanosensory lateral line system of fishes detects water motions within a few body lengths of the source. Several types of artificial stimuli have been used to probe lateral line function in the laboratory, but few studies have investigated the role of flow sensing in benthic feeding teleosts. In this study, we used artificial flows emerging from a sandy substrate to assess the contribution of flow sensing to prey detection in the peacock cichlid, Aulonocara stuartgranti, which feeds on benthic invertebrates in Lake Malawi. Using a positive reinforcement protocol, we trained fish to respond to flows lacking the visual and chemical cues generated by tethered prey in prior studies with A. stuartgranti Fish successfully responded to artificial flows at all five rates presented (characterized using digital particle image velocimetry), and showed a range of flow-sensing behaviors, including an unconditioned bite response. Immediately after lateral line inactivation, fish rarely responded to flows and the loss of vital fluorescent staining of hair cells (with 4-di-2-ASP) verified lateral line inactivation. Within 2 days post-treatment, some aspects of flow-sensing behavior returned and after 7 days, flow-sensing behavior and hair cell fluorescence both returned to pre-treatment levels, which is consistent with the reported timing of hair cell regeneration in other vertebrates. The presentation of ecologically relevant water flows to assess flow-sensing behaviors and the use of a positive reinforcement protocol are methods that present new opportunities to study the role of flow sensing in the feeding ecology of benthic feeding fishes. © 2016. Published by The Company of Biologists Ltd.

  2. Investigation of low-frequency-oscillating water flow in metal foam with 10 pores per inch

    Science.gov (United States)

    Bağcı, Ö.; Arbak, A.; De Paepe, M.; Dukhan, N.

    2018-01-01

    In this study, oscillating water flow in metal foam with open cells is investigated experimentally. The metal foam sample has a porosity of 88% and 10 pores. The water was oscillated in the test section with three frequencies between 0.116 Hz and 0.348 Hz, which are considered low for water oscillation, and three flow displacements ranging between 74.35 mm and 111.53 mm. The combinations of frequencies of displacements were studied for their impacts of dimensional and non-dimensional pressure loss quantities. To this purpose, friction factor was correlated as a function of kinetic Reynolds number. The same metal foam sample was studied by exposing it to steady-state water flow to investigate its permeability and drag coefficient in low-velocity flow regimes. The friction factor distribution for oscillating flow was found to be over that found for steady state. The outcomes of the study are important for studying heat transfer under the same flow conditions.

  3. Algal diversity in flowing waters at an acidic mine drainage "barrens" in central Pennsylvania, USA.

    Science.gov (United States)

    Prasanna, Radha; Ratha, Sachitra Kumar; Rojas, Claudia; Bruns, Mary Ann

    2011-11-01

    Microscopic investigations were undertaken to decipher the diversity in the lotic algal communities from acidic waters (pH 2.4-3.2) flowing overland in sheets and channels at an acid mine drainage (AMD) barrens near Kylertown, PA, USA. Microscopic observations, supplemented with taxonomic keys, aided in identification of the dominant algae, and measurement of carbon from adjacent soils was undertaken. The unicellular protist Euglena sp. was most abundant in slower flowing waters (i.e., pool near point of emergence and surficial flow sheets), while Ulothrix sp. was most abundant in faster flowing water from the central stream channel. A diverse range of unicellular microalgae such as Chlorella, Cylindrocystis, Botryococcus, and Navicula and several filamentous forms identified as Microspora, Cladophora, and Binuclearia were also recorded. The observed high algal diversity may be related to the long duration of AMD flow at this site which has led to the development of adapted algal communities. The comparatively higher carbon content in soil materials adjacent to slower flowing water sampling locations provides evidence for the important role of algae as primary producers in this extreme environment.

  4. Passive sampling of perfluorinated chemicals in water: flow rate effects on chemical uptake.

    Science.gov (United States)

    Kaserzon, Sarit L; Vermeirssen, Etiënne L M; Hawker, Darryl W; Kennedy, Karen; Bentley, Christie; Thompson, Jack; Booij, Kees; Mueller, Jochen F

    2013-06-01

    A recently developed modified polar organic chemical integrative sampler (POCIS) provides a means for monitoring perfluorinated chemicals (PFCs) in water. However, changes in external flow rates may alter POCIS sampling behaviour and consequently affect estimated water concentrations of analytes. In this work, uptake kinetics of selected PFCs, over 15 days, were investigated. A flow-through channel system was employed with spiked river water at flow rates between 0.02 and 0.34 m s(-1). PFC sampling rates (Rs) (0.09-0.29 L d(-1) depending on analyte and flow rate) increased from the lowest to highest flow rate employed for some PFCs (MW ≤ 464) but not for others (MW ≥ 500). Rs's for some of these smaller PFCs were increasingly less sensitive to flow rate as this increased within the range investigated. This device shows promise as a sampling tool to support monitoring efforts for PFCs in a range of flow rate conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Neuronal Responses to Water Flow in the Marine Slug Tritonia diomedea

    Directory of Open Access Journals (Sweden)

    James A. Murray

    2005-01-01

    Full Text Available The marine slug Tritonia diomedea mustrely on its ability to touch and smell in order to navigate because it is blind. The primaryfactor that influences its crawling direction is the direction of water flow (caused bytides in nature. The sensory cells that detect flow and determine flow directionhave not been identified. The lateral branch of Cerebral Nerve 2 (latCeN2 has beenidentified as the nerve that carries sensory axons to the brain from the flow receptors inthe oral tentacles. Backfilling this nerve to the brain resulted in the labeling of a numberof cells located throughout the brain. Most of the labeled cells are concentrated in the cerebral ganglion where the nerve enters thebrain. The medial and lateral branches of CeN2 were backfilled for comparison of thepattern of cells from each nerve. A map of the cells innervated by latCeN2 reveals thelocation of the stained cells. Extracellular recording from latCeN2 revealed itsinvolvement in the detection of water flow and orientation. The nerve becomes activein response to water flow stimulation. Intracellular recordings of the electricalactivity of these cells in a live animal will be the next step to determine if these cells arethe flow receptors.

  6. Neuronal responses to water flow in the marine slug tritonia diomedea

    Directory of Open Access Journals (Sweden)

    Jeffrey Blackwell

    2005-07-01

    Full Text Available The marine slug Tritonia diomedea must rely on its ability to touch and smell in order to navigate because it is blind. The primary factor that influences its crawling direction is the direction of water flow (caused by tides in nature. The sensory cells that detect flow and determine flow direction have not been identified. The lateral branch of Cerebral Nerve 2 (latCeN2 has been identified as the nerve that carries sensory axons to the brain from the flow receptors inthe oral tentacles. Backfilling this nerve to the brain resulted in the labeling of a number of cells located throughout the brain. Most of the labeled cells are concentrated in the cerebral ganglion where the nerve enters the brain. The medial and lateral branches of CeN2 were backfilled for comparison of the pattern of cells from each nerve. A map of the cells innervated by latCeN2 reveals the location of the stained cells. Extracellular recording from latCeN2 revealed its involvement in the detection of water flow and orientation. The nerve becomes active in response to water flow stimulation. Intracellular recordings of the electrical activity of these cells in a live animal will be the next step to determine if these cells are the flow receptors.

  7. Evaluation of flow regime of turbidity currents entering Dez Reservoir using extended shallow water model

    Directory of Open Access Journals (Sweden)

    Valery Ivanovich ELFIMOV

    2014-07-01

    Full Text Available In this study, the performance of the extended shallow water model (ESWM in evaluation of the flow regime of turbidity currents entering the Dez Reservoir was investigated. The continuity equations for fluid and particles and the Navier-Stokes equations govern the entire flow of turbidity currents. The shallow water equations governing the flow of the depositing phase of turbidity currents are derived from these equations. A case study was conducted on the flow regime of turbidity currents entering the Dez Reservoir in Iran from January 2002 to July 2003. Facing a serious sedimentation problem, the dead storage of the Dez Reservoir will be full in the coming 10 years, and the inflowing water in the hydropower conduit system is now becoming turbid. Based on the values of the dimensionless friction number ( and dimensionless entrainment number ( of turbidity currents, and the coefficient of determination between the observed and predicted deposit depths (R2 = 0.86 for the flow regime of negligible friction and negligible entrainment (NFNE, the flow regime of turbidity currents coming into the Dez Reservoir is considered to be NFNE. The results suggest that the ESWM is an appropriate approach for evaluation of the flow regime of turbidity currents in dam reservoirs where the characteristics of turbidity currents, such as the deposit depth, must be evaluated.

  8. Water flow through the polypropylene-based geotextiles.

    CSIR Research Space (South Africa)

    Patanaik, A

    2008-06-01

    Full Text Available Metropolitan University, Port Elizabeth 6031, South Africa Received 5 December 2007; accepted 19 January 2008 DOI 10.1002/app.28050 Published online 12 March 2008 in Wiley InterScience (www.interscience.wiley.com). ABSTRACT: This article presents... of production and product can be manufactured in a very short time. The poly- propylene fiber based nonwoven geotextiles offer fur- ther advantages due to their chemical inertness, low water absorption and quick drying capacity, which makes them ideal...

  9. Visualization of water flow during filtration using flat filtration materials

    OpenAIRE

    Hrůza Jakub; Šidlof Petr; Bílek Petr

    2012-01-01

    Filtration materials are very important elements of some industrial appliances. Water filtration is a separation of solid materials from fluid. Solid particles are captured on the frontal area of the filtration textile and only liquid passes through it. It is important to know the filtration process in a detailed way to be able to develop filtration materials. Visualization of filtration process enables a better view of the filtration. This method also enables to determine efficiency and homo...

  10. Microbiology quality in continuous water flow fish ponds

    OpenAIRE

    Lúcia Helena Sipaúba-Tavares; Luiz Augusto Amaral; Carla Fernandes Macedo

    2011-01-01

    The study verified sanitary aspects in fish ponds with sequential disposal and the effect of the tanks effluent in parallel in the system. Six fish ponds were studied in the dry and the rainy periods and were analyzed microbiological aspects (thermo tolerant coliforms, total coliforms and heterotrophic bacteria), DBO5 and DQO. It had contamination in the water of supplying for thermo tolerant coliforms, either of human or animals, compromising all the fish ponds studied with sanitary indices ...

  11. Data flows and water woes: The Utah Data Center

    Directory of Open Access Journals (Sweden)

    Mél Hogan

    2015-07-01

    Full Text Available Using a new materialist line of questioning that looks at the agential potentialities of water and its entanglements with Big Data and surveillance, this article explores how the recent Snowden revelations about the National Security Agency (NSA have reignited media scholars to engage with the infrastructures that enable intercepting, hosting, and processing immeasurable amounts of data. Focusing on the expansive architecture, location, and resource dependence of the NSA’s Utah Data Center, I demonstrate how surveillance and privacy can never be disconnected from the material infrastructures that allow and render natural the epistemological state of mass surveillance. Specifically, I explore the NSA’s infrastructure and the million of gallons of water it requires daily to cool its servers, while located in one of the driest states in the US. Complicating surveillance beyond the NSA, as also already imbricated with various social media companies, this article questions the emplacement and impact of corporate data centers more generally, and the changes they are causing to the landscape and local economies. I look at how water is an intriguing and politically relevant part of the surveillance infrastructure and how it has been constructed as the main tool for activism in this case, and how it may eventually help transform the public’s conceptualization of Big Data, as deeply material.

  12. Higher energy efficiency and better water quality by using model predictive flow control at water supply systems

    NARCIS (Netherlands)

    Bakker, M.; Verberk, J.Q.J.C.; Palmen, L.J.; Sperber, V.; Bakker, G.

    2011-01-01

    Half of all water supply systems in the Netherlands are controlled by model predictive flow control; the other half are controlled by conventional level based control. The differences between conventional level based control and model predictive control were investigated in experiments at five full

  13. Glaciation and regional ground-water flow in the Fennoscandian Shield: Site 94

    Science.gov (United States)

    Provost, Alden M.; Voss, Clifford I.; Neuzil, C.E.

    1998-01-01

    Results from a regional-scale ground-water flow model of the Fennoscandian shield suggest that ground-water flow is strongly affected by surface conditions associated with climatic change and glaciation. The model was used to run a series of numerical simulations of variable-density ground-water flow in a 1500-km-long and approximately 10-km-deep cross-section that passes through southern Sweden. Ground-water flow and shield brine transport in the cross-sectional model are controlled by an assumed time evolution of surface conditions over the next 140 ka. Simulations show that, under periglacial conditions, permafrost may locally or extensively impede the free recharge or discharge of ground water. Below cold-based glacial ice, no recharge or discharge of ground water occurs. Both of these conditions result in the settling of shield brine and consequent freshening of near-surface water in areas of natural discharge blocked by permafrost. The presence of warm-based ice with basal melting creates a potential for ground-water recharge rates much larger than under present, ice-free conditions. Recharging basal meltwater can reach depths of a few kilometers in a few thousand years. The vast majority of recharged water is accommodated through storage in the volume of bedrock below the local area of recharge; regional (lateral) redistribution of recharged water by subsurface flow is minor over the duration of a glacial advance (~10 ka). During glacial retreat, the weight of the ice overlying a given surface location decreases, and significant upward flow of ground water may occur below the ice sheet due to pressure release, despite the continued potential for recharge of basal meltwater. Excess meltwater must exit from below the glacier through subglacial cavities and channels. Subsurface penetration of meltwater during glacial advance and up-flow during glacial retreat are greatest if the loading efficiency of the shield rock is low. The maximum rate of ground-water

  14. Malignant human cell transformation of Marcellus Shale gas drilling flow back water.

    Science.gov (United States)

    Yao, Yixin; Chen, Tingting; Shen, Steven S; Niu, Yingmei; DesMarais, Thomas L; Linn, Reka; Saunders, Eric; Fan, Zhihua; Lioy, Paul; Kluz, Thomas; Chen, Lung-Chi; Wu, Zhuangchun; Costa, Max; Zelikoff, Judith

    2015-10-01

    The rapid development of high-volume horizontal hydraulic fracturing for mining natural gas from shale has posed potential impacts on human health and biodiversity. The produced flow back waters after hydraulic stimulation are known to carry high levels of saline and total dissolved solids. To understand the toxicity and potential carcinogenic effects of these wastewaters, flow back waters from five Marcellus hydraulic fracturing oil and gas wells were analyzed. The physicochemical nature of these samples was analyzed by inductively coupled plasma mass spectrometry and scanning electron microscopy/energy dispersive X-ray spectroscopy. A cytotoxicity study using colony formation as the endpoint was carried out to define the LC50 values of test samples using human bronchial epithelial cells (BEAS-2B). The BEAS-2B cell transformation assay was employed to assess the carcinogenic potential of the samples. Barium and strontium were among the most abundant metals in these samples and the same metals were found to be elevated in BEAS-2B cells after long-term treatment. BEAS-2B cells treated for 6weeks with flow back waters produced colony formation in soft agar that was concentration dependent. In addition, flow back water-transformed BEAS-2B cells show better migration capability when compared to control cells. This study provides information needed to assess the potential health impact of post-hydraulic fracturing flow back waters from Marcellus Shale natural gas mining. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. VOF modelling of gas–liquid flow in PEM water electrolysis cell micro-channels

    DEFF Research Database (Denmark)

    Lafmejani, Saeed Sadeghi; Olesen, Anders Christian; Kær, Søren Knudsen

    2017-01-01

    In this study, the gaseliquid flow through an interdigitated anode flow field of a PEM water electrolysis cell (PEMEC) is analysed using a three-dimensional, transient, computational fluid dynamics (CFD) model. To account for two-phase flow, the volume of fluid (VOF) method in ANSYS Fluent 17.2 i...... that comprises multiphase flow in porous media and micro-channel, electro-chemistry in catalyst layers, ion transport in membrane, hydrogen evolution, etc. The model can aid in the study of gaseliquid flow and its impact on the performance of a PEMEC........2 is used. The modelled geometry consists of the anode channels and the anode transport layer (ATL). To reduce the complexity of the phenomena governing PEMEC operation, the dependence upon electro-chemistry is disregarded. Instead, a fixed source of the gas is applied at the interface between the ATL......In this study, the gaseliquid flow through an interdigitated anode flow field of a PEM water electrolysis cell (PEMEC) is analysed using a three-dimensional, transient, computational fluid dynamics (CFD) model. To account for two-phase flow, the volume of fluid (VOF) method in ANSYS Fluent 17...

  16. Phase distribution of nitrogen-water two-phase flow in parallel micro channels

    Science.gov (United States)

    Zhou, Mi; Wang, Shuangfeng; Zhou, You

    2017-04-01

    The present work experimentally investigated the phase splitting characteristics of gas-liquid two-phase flow passing through a horizontal-oriented micro-channel device with three parallel micro-channels. The hydraulic diameters of the header and the branch channels were 0.6 and 0.4 mm, respectively. Five different liquids, including de-ionized water and sodium dodecyl sulfate (SDS) solution with different concentration were employed. Different from water, the surface tension of SDS solution applied in this work decreased with the increment of mass concentration. Through series of visual experiments, it was found that the added SDS surfactant could obviously facilitate the two-phase flow through the parallel micro channels while SDS solution with low concentration would lead to an inevitable blockage of partial outlet branches. Experimental results revealed that the two phase distribution characteristics depended highly on the inlet flow patterns and the outlet branch numbers. To be specific, at the inlet of slug flow, a large amount of gas preferred flowing into the middle branch channel while the first branch was filled with liquid. However, when the inlet flow pattern was shifted to annular flow, all of the gas passed through the second and the last branches, with a little proportion of liquid flowing into the first channel. By comparison with the experimental results obtained from a microchannel device with five parallel micro-T channels, uneven distribution of the two phase can be markedly noticed in our present work.

  17. Investigation into the effect of water chemistry on corrosion product formation in areas of accelerated flow

    Science.gov (United States)

    McGrady, John; Scenini, Fabio; Duff, Jonathan; Stevens, Nicholas; Cassineri, Stefano; Curioni, Michele; Banks, Andrew

    2017-09-01

    The deposition of CRUD (Chalk River Unidentified Deposit) in the primary circuit of a Pressurised Water Reactor (PWR) is known to preferentially occur in regions of the circuit where flow acceleration of coolant occurs. A micro-fluidic flow cell was used to recreate accelerated flow under simulated PWR conditions, by flowing water through a disc with a central micro-orifice. CRUD deposition was reproduced on the disc, and CRUD Build-Up Rates (BUR) in various regions of the disc were analysed. The effect of the local environment on BUR was investigated. In particular, the effect of flow velocity, specimen material and Fe concentration were considered. The morphology and composition of the deposits were analysed with respect to experimental conditions. The BUR of CRUD was found to be sensitive to flow velocity and Fe concentration, suggesting that mass transfer is an important factor. The morphology of the deposit was affected by the specimen material indicating a dependence on surface/particle electrostatics meaning surface chemistry plays an important role in deposition. The preferential deposition of CRUD in accelerated flow regions due to electrokinetic effects was observed and it was shown that higher Fe concentrations in solution increased BURs within the orifice whereas increased flow velocity reduced BURs.

  18. Countercurrent Air-Water Flow in a Scale-Down Model of a Pressurizer Surge Line

    Directory of Open Access Journals (Sweden)

    Takashi Futatsugi

    2012-01-01

    Full Text Available Steam generated in a reactor core and water condensed in a pressurizer form a countercurrent flow in a surge line between a hot leg and the pressurizer during reflux cooling. Characteristics of countercurrent flow limitation (CCFL in a 1/10-scale model of the surge line were measured using air and water at atmospheric pressure and room temperature. The experimental results show that CCFL takes place at three different locations, that is, at the upper junction, in the surge line, and at the lower junction, and its characteristics are governed by the most dominating flow limitation among the three. Effects of inclination angle and elbows of the surge line on CCFL characteristics were also investigated experimentally. The effects of inclination angle on CCFL depend on the flow direction, that is, the effect is large for the nearly horizontal flow and small for the vertical flow at the upper junction. The presence of elbows increases the flow limitation in the surge line, whereas the flow limitations at the upper and lower junctions do not depend on the presence of elbows.

  19. Geohydrological characterization, water-chemistry, and ground-water flow simulation model of the Sonoma Valley area, Sonoma County, California

    Science.gov (United States)

    Farrar, Christopher D.; Metzger, Loren F.; Nishikawa, Tracy; Koczot, Kathryn M.; Reichard, Eric G.; Langenheim, V.E.

    2006-01-01

    The Sonoma Valley, located about 30 miles north of San Francisco, is one of several basins in Sonoma County that use a combination of ground water and water delivered from the Russian River for supply. Over the past 30 years, Sonoma Valley has experienced rapid population growth and land-use changes. In particular, there has been a significant increase in irrigated agriculture, predominantly vineyards. To provide a better understanding of the ground-water/surface-water system in Sonoma Valley, the U.S. Geological Survey compiled and evaluated existing data, collected and analyzed new data, and developed a ground-water flow model to better understand and manage the ground-water system. The new data collected include subsurface lithology, gravity measurements, groundwater levels, streamflow gains and losses, temperature, water chemistry, and stable isotopes. Sonoma Valley is drained by Sonoma Creek, which discharges into San Pablo Bay. The long-term average annual volume of precipitation in the watershed is estimated to be 269,000 acre-feet. Recharge to the ground-water system is primarily from direct precipitation and Sonoma Creek. Discharge from the ground-water system is predominantly outflow to Sonoma Creek, pumpage, and outflow to marshlands and to San Pablo Bay. Geologic units of most importance for groundwater supply are the Quaternary alluvial deposits, the Glen Ellen Formation, the Huichica Formation, and the Sonoma Volcanics. In this report, the ground-water system is divided into three depth-based geohydrologic units: upper (less than 200 feet below land surface), middle (between 200 and 500 feet), and lower (greater than 500 feet). Synoptic streamflow measurements were made along Sonoma Creek and indicate those reaches with statistically significant gains or losses. Changes in ground-water levels in wells were analyzed by comparing historical contour maps with the contour map for 2003. In addition, individual hydrographs were evaluated to assess temporal

  20. Hydrology and simulation of ground-water flow in Juab Valley, Juab County, Utah.

    Science.gov (United States)

    Thiros, Susan A.; Stolp, Bernard J.; Hadley, Heidi K.; Steiger, Judy I.

    1996-01-01

    Plans to import water to Juab Valley, Utah, primarily for irrigation, are part of the Central Utah Project. A better understanding of the hydrology of the valley is needed to help manage the water resources and to develop conjunctive-use plans.The saturated unconsolidated basin-fill deposits form the ground-water system in Juab Valley. Recharge is by seepage from streams, unconsumed irrigation water, and distribution systems; infiltration of precipitation; and subsurface inflow from consolidated rocks that surround the valley. Discharge is by wells, springs, seeps, evapotranspiration, and subsurface outflow to consolidated rocks. Ground-water pumpage is used to supplement surface water for irrigation in most of the valley and has altered the direction of groundwater flow from that of pre-ground-water development time in areas near and in Nephi and Levan.Greater-than-average precipitation during 1980-87 corresponds with a rise in water levels measured in most wells in the valley and the highest water level measured in some wells. Less-than average precipitation during 1988-91 corresponds with a decline in water levels measured during 1988-93 in most wells. Geochemical analyses indicate that the sources of dissolved ions in water sampled from the southern part of the valley are the Arapien Shale, evaporite deposits that occur in the unconsolidated basin-fill deposits, and possibly residual sea water that has undergone evaporation in unconsolidated basin-fill deposits in selected areas. Water discharging from a spring at Burriston Ponds is a mixture of about 70 percent ground water from a hypothesized flow path that extends downgradient from where Salt Creek enters Juab Valley and 30 percent from a hypothesized flow path from the base of the southern Wasatch Range.The ground-water system of Juab Valley was simulated by using the U.S. Geological Survey modular, three-dimensional, finite-difference, ground-water flow model. The numerical model was calibrated to simulate

  1. 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...

  2. Controlling factors for water residence time and flow patterns in Ekeby treatment wetland, Sweden

    Science.gov (United States)

    Kjellin, Johan; Wörman, Anders; Johansson, Håkan; Lindahl, Anna

    2007-04-01

    Treatment wetlands play an important role in reducing nutrient content and heavy metals in wastewater and run-off water. The treatment efficiency strongly depends on flow pattern and residence times of the water. Here, we study the impact of different factors on water flow patterns based on a tracer experiment with tritiated water in a 2.6 ha constructed wetland pond. A 2D flow and inert transport model was used to evaluate the relative importance of bottom topography, vegetation distribution, water exchange with stagnant zones and dispersion. Results from computer simulations and independent measurements of friction losses as well as wetland geometry showed that variations in bottom topography, formed by several deep zones, decreased the variance in water residence times to a minor extent. Heterogeneity in vegetation, on the other hand, significantly contributed to the spread in water residence times and explained the multiple peaks observed in the breakthrough curves. Analyses showed that in the Ekeby treatment wetland, basin shape explained about 10% of the variance in the observed residence times, whereas vegetation explained about 60-80%. To explain all variance secondary factors were needed, such as dispersion and water exchange with stagnant zones. These were shown to contribute to the spread of residence times and primarily to the long tail of the observed breakthrough curves.

  3. Water imbibition by mica pores: what happens when capillary flow is suppressed?

    Science.gov (United States)

    Fang, Chao; Qiao, Rui

    2017-11-01

    The imbibition of liquids into porous media plays a critical role in numerous applications. Most prior studies focused on imbibition driven by capillary flows. In this work, we study the imbibition of water into slit-shaped mica pores filled with pressurized methane using molecular simulations. Despite that capillary flow is suppressed by the high gas pressure, water is imbibed into the pore as monolayer liquid films. Since the classical hydrodynamic flow is not readily applicable for the monolayer water film propagating on the mica wall and the imbibition is driven by the strong affinity of water molecules to the mica walls, the observed imbibition is best taken as surface hydration. We show that the dynamics of water's imbibition front follows a simple diffusive scaling law. The effective diffusion coefficient of the imbibition front, however, is more than ten times larger than the diffusion coefficient of the water molecules in the water film adsorbed on the mica walls. Using a molecular theory originally developed for the spreading of monolayer films on solid substrates, we clarify the mechanism underlying the rapid water imbibition observed here.

  4. Blue Planet dialysis: novel water-sparing strategies for reducing dialysate flow.

    Science.gov (United States)

    Molano-Triviño, Alejandra; Wancjer, Benjamin; Neri, Mauro M; Karopadi, Akash N; Rosner, Mitchell; Ronco, Claudio

    2017-11-08

    Hemodialysis (HD) is an expensive therapy in economic and in ecological terms, owing to a high carbon footprint and significant consumption of natural sources, especially water. Our aim was to review strategies to diminish waste of water in maintenance dialysis, exploring previously described water reuse trends and less known strategies for reducing the dialysate flow. We conducted a systematic review of water-sparing strategies, including the reuse of reverse osmosis rejected water and the reduction of dialysate flux. We performed a search in Medline, Pubmed, Scielo, OVID and Biblioteca Redentor, using key words: Dialysate flow rate, Dialysate flux, and decrease; excluding: online, peritoneal, continuous, blood access, needle, hemodiafiltration, acute, pharmacokinetics, increase. We limited our search to adult humans or in vitro trials in English, Spanish, Italian and Portuguese, between January 1980 and June 2017. We found 816 trials. 37 articles were retrieved for review, and 11 articles were analyzed. Conservation of water in chronic HD should be considered an important responsibility of healthcare practitioners all over the world. We present a wider usage of dialysate flow rates, considering that it would lead to significant water conservation without much compromise on dialysis efficacy in small patients. We believe that further investigation into the utility of reduced dialysate flux in different populations is needed to broaden our understanding of how we can use these techniques in order to significantly reduce water consumption during chronic HD while still ensuring optimum efficacy and efficiency of the therapy.

  5. How fast does water flow in carbon nanotubes?

    DEFF Research Database (Denmark)

    Kannam, Sridhar; Todd, Billy; Hansen, Jesper Schmidt

    2013-01-01

    the slip length using equilibrium molecular dynamics (EMD) simulations, from which the interfacial friction between water and carbon nanotubes can be found, and also via external field driven non-equilibrium molecular dynamics simulations (NEMD). We discuss some of the issues in simulation studies which...... may be reasons for the large disagreements reported. By using the EMD method friction coefficient to determine the slip length, we overcome the limitations of NEMD simulations. In NEMD simulations, for each tube we apply a range of external fields to check the linear response of the fluid to the field...

  6. Net transport of suspended matter due to tidal straining

    Science.gov (United States)

    Jones, S. E.; Jago, C. F.; Simpson, J. H.; Rippeth, T. P.

    2003-04-01

    Net transport of suspended particulate matter (SPM) is well-known in tidal regions where there is time-velocity asymmetry due to frictional modification of the tide in shallow water. We present here observations which show a new mechanism for net flux of SPM in response to tidal straining in a region of freshwater influence (ROFI). In situ measurements of the particle size of suspended particulate matter (SPM) and turbulent energy dissipation have been made at a site in Liverpool Bay (Irish Sea) where there is significant resuspension of particles from the muddy sand substrate during spring tides. This is a ROFI where tidal straining dominates the temporal development of turbulence. On a spring tide the water column tries to stratify on the ebb and destratify on the flood, but these tendencies are masked by mixing due to tidal stirring. Nevertheless, there is a marked excess of TKE dissipation rate E on the flood, especially in the upper part of the water column. Resuspension occurs on both flood and ebb, but SPM flux is strongly asymmetric with a net shorewards component. Asymmetry is most pronounced for the larger particles which comprise most of the mass. Enhanced ? on the flood mixes large particles upwards into faster flowing water, which increases the flux. Comparable upwards mixing of large particles does not occur on the ebb where enhanced E is confined to slower bottom waters. The net flux is not seen on neap tides because, although there is more stratification due to tidal straining, there is essentially no resuspension. The net flux on springs is undoubtedly an important component of SPM transport (and any comparable particulates) in coastal regions.

  7. How Important Is Connectivity for Surface Water Fluxes? A Generalized Expression for Flow Through Heterogeneous Landscapes

    Science.gov (United States)

    Larsen, Laurel G.; Ma, Jie; Kaplan, David

    2017-10-01

    How important is hydrologic connectivity for surface water fluxes through heterogeneous floodplains, deltas, and wetlands? While significant for management, this question remains poorly addressed. Here we adopt spatial resistance averaging, based on channel and patch configuration metrics quantifiable from aerial imagery, to produce an upscaled rate law for discharge. Our model suggests that patch coverage largely controls discharge sensitivity, with smaller effects from channel connectivity and vegetation patch fractal dimension. However, connectivity and patch configuration become increasingly important near the percolation threshold and at low water levels. These effects can establish positive feedbacks responsible for substantial flow change in evolving landscapes (14-36%, in our Everglades case study). Connectivity also interacts with other drivers; flow through poorly connected hydroscapes is less resilient to perturbations in other drivers. Finally, we found that flow through heterogeneous patches is alone sufficient to produce non-Manning flow-depth relationships commonly observed in wetlands but previously attributed to depth-varying roughness.

  8. Flow Patterns Transition Law of Oil-Water Two-Phase Flow under a Wide Range of Oil Phase Viscosity Condition

    OpenAIRE

    Wei Wang(College of William and Mary); Wei Cheng; Kai Li; Chen Lou; Jing Gong

    2013-01-01

    A systematic work on the prediction of flow patterns transition of the oil-water two-phase flows is carried out under a wide range of oil phase viscosities, where four main flow regimes are considered including stratified, dispersed, core-annular, and intermittent flow. For oil with a relatively low viscosity, VKH criterion is considered for the stability of stratified flow, and critical drop size model is distinguished for the transition of o/w and w/o dispersed flow. For oil with a high vis...

  9. Water flowing north of the border: export agriculture and water politics in a rural community in Baja California.

    Science.gov (United States)

    Zlolniski, Christian

    2011-01-01

    Favored by neoliberal agrarian policies, the production of fresh crops for international markets has become a common strategy for economic development in Mexico and other Latin American countries. But as some scholars have argued, the global fresh produce industry in developing countries in which fresh crops are produced for consumer markets in affluent nations implies “virtual water flows,” the transfer of high volumes of water embedded in these crops across international borders. This article examines the local effects of the production of fresh produce in the San Quintín Valley in northwestern Mexico for markets in the United States. Although export agriculture has fostered economic growth and employment opportunities for indigenous farm laborers, it has also led to the overexploitation of underground finite water resources, and an alarming decline of the quantity and quality of water available for residents’ domestic use. I discuss how neoliberal water policies have further contributed to water inequalities along class and ethnic lines, the hardships settlers endure to secure access to water for their basic needs, and the political protests and social tensions water scarcity has triggered in the region. Although the production of fresh crops for international markets is promoted by organizations such as the World Bank and Inter-American Development Bank as a model for economic development, I argue that it often produces water insecurity for the poorest, threatening the UN goal of ensuring access to clean water as a universal human right.

  10. Mathematical modelling of surface water-groundwater flow and salinity interactions in the coastal zone

    Science.gov (United States)

    Spanoudaki, Katerina; Kampanis, Nikolaos A.

    2014-05-01

    Coastal areas are the most densely-populated areas in the world. Consequently water demand is high, posing great pressure on fresh water resources. Climatic change and its direct impacts on meteorological variables (e.g. precipitation) and indirect impact on sea level rise, as well as anthropogenic pressures (e.g. groundwater abstraction), are strong drivers causing groundwater salinisation and subsequently affecting coastal wetlands salinity with adverse effects on the corresponding ecosystems. Coastal zones are a difficult hydrologic environment to represent with a mathematical model due to the large number of contributing hydrologic processes and variable-density flow conditions. Simulation of sea level rise and tidal effects on aquifer salinisation and accurate prediction of interactions between coastal waters, groundwater and neighbouring wetlands requires the use of integrated surface water-groundwater models. In the past few decades several computer codes have been developed to simulate coupled surface and groundwater flow. In these numerical models surface water flow is usually described by the 1-D Saint Venant equations (e.g. Swain and Wexler, 1996) or the 2D shallow water equations (e.g. Liang et al., 2007). Further simplified equations, such as the diffusion and kinematic wave approximations to the Saint Venant equations, are also employed for the description of 2D overland flow and 1D stream flow (e.g. Gunduz and Aral, 2005). However, for coastal bays, estuaries and wetlands it is often desirable to solve the 3D shallow water equations to simulate surface water flow. This is the case e.g. for wind-driven flows or density-stratified flows. Furthermore, most integrated models are based on the assumption of constant fluid density and therefore their applicability to coastal regions is questionable. Thus, most of the existing codes are not well-suited to represent surface water-groundwater interactions in coastal areas. To this end, the 3D integrated

  11. Theoretical study of motion of small spherical air bubbles in a uniform shear flow of water

    Directory of Open Access Journals (Sweden)

    Syed Murtuza Mehdi

    2015-02-01

    Full Text Available A simple Couette flow velocity profile with an appropriate correlation for the free terminal rise velocity of a single bubble in a quiescent liquid can produce reliable results for the trajectories of small spherical air bubbles in a low-viscosity liquid (water provided the liquid remains under uniform shear flow. Comparison of the model adopted in this paper with published results has been accomplished. Based on this study it has also been found that the lift coefficient in water is higher than its typical value in a high-viscosity liquid and therefore a modified correlation for the lift coefficient in a uniform shear flow of water within the regime of the Eötvös number 0.305≤Eo≤1.22 is also presented.

  12. An isotopic model for basal freeze-on associated with subglacial upward flow of pore water

    Science.gov (United States)

    Souchez, R.; Samyn, D.; Lorrain, R.; Pattyn, F.; Fitzsimons, S.

    2004-01-01

    Subglacial freezing in polar glaciers can have a significant dynamical effect. Recent studies have shown that freezing of pore water flowing upward through subglacial fine-grained sediments at the freezing interface and progression of this freezing front downward are responsible for fast ice flow stoppage in ice streams. The upward pore water flow leads to the formation of debris-bearing basal ice layers. A model for stable isotope composition, both in δD and δ18O, is developed for predicting the isotopic composition of the ice segregated by such a mechanism. The development of this isotopic model for water films present along the grains of the subglacial sediment predicts the absence of apparent fractionation for the ice formed. This prediction is tested against two East Antarctic outlet glaciers by studying the δD-δ18O relationships in the basal ice layers of these glaciers.

  13. Ground water stratification and delivery of nitrate to an incised stream under varying flow conditions.

    Science.gov (United States)

    Böhlke, J K; O'Connell, Michael E; Prestegaard, Karen L

    2007-01-01

    Ground water processes affecting seasonal variations of surface water nitrate concentrations were investigated in an incised first-order stream in an agricultural watershed with a riparian forest in the coastal plain of Maryland. Aquifer characteristics including sediment stratigraphy, geochemistry, and hydraulic properties were examined in combination with chemical and isotopic analyses of ground water, macropore discharge, and stream water. The ground water flow system exhibits vertical stratification of hydraulic properties and redox conditions, with sub-horizontal boundaries that extend beneath the field and adjacent riparian forest. Below the minimum water table position, ground water age gradients indicate low recharge rates (2-5 cm yr(-1)) and long residence times (years to decades), whereas the transient ground water wedge between the maximum and minimum water table positions has a relatively short residence time (months to years), partly because of an upward increase in hydraulic conductivity. Oxygen reduction and denitrification in recharging ground waters are coupled with pyrite oxidation near the minimum water table elevation in a mottled weathering zone in Tertiary marine glauconitic sediments. The incised stream had high nitrate concentrations during high flow conditions when much of the ground water was transmitted rapidly across the riparian zone in a shallow oxic aquifer wedge with abundant outflow macropores, and low nitrate concentrations during low flow conditions when the oxic wedge was smaller and stream discharge was dominated by upwelling from the deeper denitrified parts of the aquifer. Results from this and similar studies illustrate the importance of near-stream geomorphology and subsurface geology as controls of riparian zone function and delivery of nitrate to streams in agricultural watersheds.

  14. Hydroecological factors governing surface water flow on a low-gradient floodplain

    Science.gov (United States)

    Harvey, Judson W.; Schaffranek, Raymond W.; Noe, Gregory B.; Larsen, Laurel G.; Nowacki, Daniel; ,

    2009-01-01

    "Interrelationships between hydrology and aquatic ecosystems are better understood in streams and rivers compared to their surrounding floodplains. Our goal was to characterize the hydrology of the Everglades ridge and slough floodplain ecosystem, which is valued for the comparatively high biodiversity and connectivity of its parallel-drainage features but which has been degraded over the past century in response to flow reductions associated with flood control. We measured flow velocity, water depth, and wind velocity

  15. Documentation of finite-difference model for simulation of three-dimensional ground-water flow

    Science.gov (United States)

    Trescott, Peter C.; Larson, S.P.

    1976-01-01

    User experience has indicated that the documentation of the model of three-dimensional ground-water flow (Trescott and Larson, 1975) should be expanded. This supplement is intended to fulfill that need. The original report emphasized the theory of the strongly implicit procedure, instructions for using the groundwater-flow model, and practical considerations for application. (See also W76-02962 and W76-13085) (Woodard-USGS)

  16. Effects of historic forest disturbance on water quality and flow in the Interior Western U.S

    Science.gov (United States)

    M. Matyjasik; G. Moisen; C. Combe; T. Hathcock; S. Mitts; M. Hernandez; T. Frescino; T. Schroeder

    2014-01-01

    Water quality and flow is affected my many complex factors in the Interior Western U.S. While many studies focus on individual water parameters response to a limited number of changing conditions, little work looks at long term effects of diverse forest disturbances on a broader array of water quality and flow metrics. The U.S. Forest Service Forest Inventory and...

  17. Physiological plasticity to water flow habitat in the damselfish, Acanthochromis polyacanthus: linking phenotype to performance.

    Directory of Open Access Journals (Sweden)

    Sandra A Binning

    Full Text Available The relationships among animal form, function and performance are complex, and vary across environments. Therefore, it can be difficult to identify morphological and/or physiological traits responsible for enhancing performance in a given habitat. In fishes, differences in swimming performance across water flow gradients are related to morphological variation among and within species. However, physiological traits related to performance have been less well studied. We experimentally reared juvenile damselfish, Acanthochromis polyacanthus, under different water flow regimes to test 1 whether aspects of swimming physiology and morphology show plastic responses to water flow, 2 whether trait divergence correlates with swimming performance and 3 whether flow environment relates to performance differences observed in wild fish. We found that maximum metabolic rate, aerobic scope and blood haematocrit were higher in wave-reared fish compared to fish reared in low water flow. However, pectoral fin shape, which tends to correlate with sustained swimming performance, did not differ between rearing treatments or collection sites. Maximum metabolic rate was the best overall predictor of individual swimming performance; fin shape and fish total length were 3.3 and 3.7 times less likely than maximum metabolic rate to explain differences in critical swimming speed. Performance differences induced in fish reared in different flow environments were less pronounced than in wild fish but similar in direction. Our results suggest that exposure to water motion induces plastic physiological changes which enhance swimming performance in A. polyacanthus. Thus, functional relationships between fish morphology and performance across flow habitats should also consider differences in physiology.

  18. Water Flow Testing and Unsteady Pressure Analysis of a Two-Bladed Liquid Oxidizer Pump Inducer

    Science.gov (United States)

    Schwarz, Jordan B.; Mulder, Andrew; Zoladz, Thomas

    2011-01-01

    The unsteady fluid dynamic performance of a cavitating two-bladed oxidizer turbopump inducer was characterized through sub-scale water flow testing. While testing a novel inlet duct design that included a cavitation suppression groove, unusual high-frequency pressure oscillations were observed. With potential implications for inducer blade loads, these high-frequency components were analyzed extensively in order to understand their origins and impacts to blade loading. Water flow testing provides a technique to determine pump performance without the costs and hazards associated with handling cryogenic propellants. Water has a similar density and Reynolds number to liquid oxygen. In a 70%-scale water flow test, the inducer-only pump performance was evaluated. Over a range of flow rates, the pump inlet pressure was gradually reduced, causing the flow to cavitate near the pump inducer. A nominal, smooth inducer inlet was tested, followed by an inlet duct with a circumferential groove designed to suppress cavitation. A subsequent 52%-scale water flow test in another facility evaluated the combined inducer-impeller pump performance. With the nominal inlet design, the inducer showed traditional cavitation and surge characteristics. Significant bearing loads were created by large side loads on the inducer during synchronous cavitation. The grooved inlet successfully mitigated these loads by greatly reducing synchronous cavitation, however high-frequency pressure oscillations were observed over a range of frequencies. Analytical signal processing techniques showed these oscillations to be created by a rotating, multi-celled train of pressure pulses, and subsequent CFD analysis suggested that such pulses could be created by the interaction of rotating inducer blades with fluid trapped in a cavitation suppression groove. Despite their relatively low amplitude, these high-frequency pressure oscillations posed a design concern due to their sensitivity to flow conditions and

  19. Geohydrology and simulations of ground-water flow at Verona well field, Battle Creek, Michigan, 1988

    Science.gov (United States)

    Lynch, E.A.; Grannemann, N.G.

    1997-01-01

    Public water supply for the city of Battle Creek, Mich. is withdrawn from the Marshall Sandstone through wells at the Verona well field. Analysis of borehole acoustic televiewer, gamma, and single-point-resistance logs from wells in Bailey Park, near the well field, indicates 12 fracture zones in the Marshall Sandstone. Further interpretation of flow-meter and temperature logs from the same wells indicates that the fracture zones are locally interconnected but appear to remain isolated over a lateral distance of 3,000 feet. Organic chemicals were detected in water samples collected from water-supply wells in the Verona well field in 1981. In 1985, six water-supply wells were converted to purge wells to intercept organic chemicals and divert them from the remaining water-supply wells. Removal of these wells from service resulted in a water-supply shortage. A proposal in which an alternative purge system could be installed so that wells that are out of service may be reactivated was examined. A ground-water-flow model developed for this study indicates that, under the current purge configuration, most water from contaminant-source areas either is captured by purge wells or flows to the Battle Creek River. Some water, however, is captured by three water-supply wells. Model simulations indicate that with the addition of eight purge wells, the well field would be protected from contamination, most water from the contaminant-source areas would be captured by the purge system, and only a small portion would flow to the Battle Creek River. In an effort to augment the city's water supply, the potential for expansion of the Verona well field to the northeast also was investigated. Because of the addition of three municipal wells northeast of the well field, some water from the site of a gasoline spill may be captured by two water-supply wells. Ground water in the area northeast of Verona well field contains significantly lower concentrations of iron, manganese, and calcium

  20. Numerical Simulation of Water Jet Flow Using Diffusion Flux Mixture Model

    Directory of Open Access Journals (Sweden)

    Zhi Shang

    2014-01-01

    Full Text Available A multidimensional diffusion flux mixture model was developed to simulate water jet two-phase flows. Through the modification of the gravity using the gradients of the mixture velocity, the centrifugal force on the water droplets was able to be considered. The slip velocities between the continuous phase (gas and the dispersed phase (water droplets were able to be calculated through multidimensional diffusion flux velocities based on the modified multidimensional drift flux model. Through the numerical simulations, comparing with the experiments and the simulations of traditional algebraic slip mixture model on the water mist spray, the model was validated.

  1. Treatment of fishpond water by recirculating horizontal and vertical flow constructed wetlands in the tropics

    DEFF Research Database (Denmark)

    Konnerup, Dennis; Trang, Ngo Thuy Diem; Brix, Hans

    2011-01-01

    Common practice of aquaculture in Vietnam and other countries in South East Asia involves frequent discharge of polluted water into rivers which results in eutrophication and degradation of receiving water bodies. There is therefore a need to develop improved aquaculture systems which have a more...... quantities of phytoplankton algae were removed in the CWs but abundance of toxic algae such as Microcystis was low. It is concluded that particularly vertical flow CWs have great potential for treatment of fishpond water in recirculating aquaculture systems in the tropics as the discharge of polluted water...

  2. Determination of flow rates of oil, water and gas in pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Roach, G.J.; Watt, J.S.; Zastawny, H.W. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Lucas Heights, NSW (Australia). Div. of Mineral Physics

    1993-12-31

    This paper describes a multiphase flow meter developed by CSIRO for determining of the flow rates of oil, water and gas in high pressure pipelines, and the results of a trial of this flow meter on an offshore oil platform. Two gamma-ray transmission gauges are mounted about a pipeline carrying the full flow of oil, water and gas. The flow rates are determined by combining single energy gamma-ray transmission measurements which determine the mass per unit area of fluids in the gamma-ray beam as a function of time, dual energy gamma-ray transmission (DUET) which determine the approximate mass fraction of oil in the liquids, cross-correlation of gamma-ray transmission measurements, with one gauge upstream of the other, which determines flow velocity, pressure and temperature measurements, and knowledge of the specific gravities of oil and (salt) water, and solubility of the gas in the liquids, all as a function of pressure and temperature. 3 figs.

  3. Behavior of CO2/water flow in porous media for CO2geological storage.

    Science.gov (United States)

    Jiang, Lanlan; Yu, Minghao; Liu, Yu; Yang, Mingjun; Zhang, Yi; Xue, Ziqiu; Suekane, Tetsuya; Song, Yongchen

    2017-04-01

    A clear understanding of two-phase fluid flow properties in porous media is of importance to CO 2 geological storage. The study visually measured the immiscible and miscible displacement of water by CO 2 using MRI (magnetic resonance imaging), and investigated the factor influencing the displacement process in porous media which were filled with quartz glass beads. For immiscible displacement at slow flow rates, the MR signal intensity of images increased because of CO 2 dissolution; before the dissolution phenomenon became inconspicuous at flow rate of 0.8mLmin -1 . For miscible displacement, the MR signal intensity decreased gradually independent of flow rates, because supercritical CO 2 and water became miscible in the beginning of CO 2 injection. CO 2 channeling or fingering phenomena were more obviously observed with lower permeable porous media. Capillary force decreases with increasing particle size, which would increase permeability and allow CO 2 and water to invade into small pore spaces more easily. The study also showed CO 2 flow patterns were dominated by dimensionless capillary number, changing from capillary finger to stable flow. The relative permeability curve was calculated using Brooks-Corey model, while the results showed the relative permeability of CO 2 slightly decreases with the increase of capillary number. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. A study on effects of ceramic foam filter on flow aspect through water modeling experiment

    Directory of Open Access Journals (Sweden)

    Ho-Young Hwang

    2017-05-01

    Full Text Available Casting defects that are closely related to entrapped air bubbles and metallic oxides occur very frequently in the sand mold casting process. Many researchers have shown that these defects can be reduced by adopting an appropriate gating system design. However, it is difficult for field engineers to identify a specific gating system that is more appropriate for their products. In this study, we tried to draw a comparison between two gating system designs with and without a ceramic foam filter. The ceramic foam filter was added to the horizontal runner just after the down sprue to prevent air bubble generation and reduce turbulence without a change of gating system design. The water modeling experiment was conducted with four different amounts of the initial volumes of water in the reservoir to verify the effects of initial pouring velocity. The results of the experiment applying the filter showed remarkably changed flow characteristics. The use of the filter was found to convert the flow pattern of water in the desired direction. The ceramic foam filter performed well to reduce flow velocity and stabilize the water stream.The flow pattern without a filter can be improved significantly even with the the use of just a 10 PPI irregular filter. Although the study confirmed that use of the filter may change the flow characteristics, it needs to be noted that the use of the ceramic filter alone cannot solve all the problems caused by a poorly designed gating system.

  5. Device for removing floating liquid impurities, oil, from a flowing water surface

    Energy Technology Data Exchange (ETDEWEB)

    Szereday, P.

    1983-02-08

    Separation of impure surface water layer, separation of mixture of impurities and water and method for implementation of discharging impurities separated, according to which local water level lowering required for flowing impure surface water layer through overflow spillway is performed in conformity with the bernoulli formula by suction effect produced and maintained by increasing flow rate, while separation taking place in the same step is carried out by the transient decrease of flow rate, then by change of direction. By turbulent-free inflow without decrease of rate really excellent scraping efficiency can be achieved. The device for carrying out said method comprises a submersion body of submersion depth first increasing downstream then decreasing, provided with opening serving as hopper to produce suction effect , on bottom in range of greatest submersion cross-section or behind latter, with adjustable spillway on front end on side of inflow, whereas with baffle plate controlling direction of flow and defining cross-section in inner space of submersion body, and with a flow-free zone for collecting the impurities separated.

  6. Energy Harvesting from Fluid Flow in Water Pipelines for Smart Metering Applications

    Science.gov (United States)

    Hoffmann, D.; Willmann, A.; Göpfert, R.; Becker, P.; Folkmer, B.; Manoli, Y.

    2013-12-01

    In this paper a rotational, radial-flux energy harvester incorporating a three-phase generation principle is presented for converting energy from water flow in domestic water pipelines. The energy harvester together with a power management circuit and energy storage is used to power a smart metering system installed underground making it independent from external power supplies or depleting batteries. The design of the radial-flux energy harvester is adapted to the housing of a conventional mechanical water flow meter enabling the use of standard components such as housing and impeller. The energy harvester is able to generate up to 720 mW when using a flow rate of 20 l/min (fully opened water tab). A minimum flow rate of 3 l/min is required to get the harvester started. In this case a power output of 2 mW is achievable. By further design optimization of the mechanical structure including the impeller and magnetic circuit the threshold flow rate can be further reduced.

  7. Use of a ground-water flow model with particle tracking to evaluate ground-water vulnerability, Clark County, Washington

    Science.gov (United States)

    Snyder, D.T.; Wilkinson, J.M.; Orzol, L.L.

    1996-01-01

    A ground-water flow model was used in conjunction with particle tracking to evaluate ground-water vulnerability in Clark County, Washington. Using the particle-tracking program, particles were placed in every cell of the flow model (about 60,000 particles) and tracked backwards in time and space upgradient along flow paths to their recharge points. A new computer program was developed that interfaces the results from a particle-tracking program with a geographic information system (GIS). The GIS was used to display and analyze the particle-tracking results. Ground-water vulnerability was evaluated by selecting parts of the ground-water flow system and combining the results with ancillary information stored in the GIS to determine recharge areas, characteristics of recharge areas, downgradient impact of land use at recharge areas, and age of ground water. Maps of the recharge areas for each hydrogeologic unit illustrate the presence of local, intermediate, or regional ground-water flow systems and emphasize the three-dimensional nature of the ground-water flow system in Clark County. Maps of the recharge points for each hydrogeologic unit were overlaid with maps depicting aquifer sensitivity as determined by DRASTIC (a measure of the pollution potential of ground water, based on the intrinsic characteristics of the near-surface unsaturated and saturated zones) and recharge from on-site waste-disposal systems. A large number of recharge areas were identified, particularly in southern Clark County, that have a high aquifer sensitivity, coincide with areas of recharge from on-site waste-disposal systems, or both. Using the GIS, the characteristics of the recharge areas were related to the downgradient parts of the ground-water system that will eventually receive flow that has recharged through these areas. The aquifer sensitivity, as indicated by DRASTIC, of the recharge areas for downgradient parts of the flow system was mapped for each hydrogeologic unit. A number of

  8. Applications of Continuous-Flow Photochemistry in Organic Synthesis, Material Science, and Water Treatment.

    Science.gov (United States)

    Cambié, Dario; Bottecchia, Cecilia; Straathof, Natan J W; Hessel, Volker; Noël, Timothy

    2016-09-14

    Continuous-flow photochemistry in microreactors receives a lot of attention from researchers in academia and industry as this technology provides reduced reaction times, higher selectivities, straightforward scalability, and the possibility to safely use hazardous intermediates and gaseous reactants. In this review, an up-to-date overview is given of photochemical transformations in continuous-flow reactors, including applications in organic synthesis, material science, and water treatment. In addition, the advantages of continuous-flow photochemistry are pointed out and a thorough comparison with batch processing is presented.

  9. Continuum Navier-Stokes modelling of water flow past fullerene molecules

    DEFF Research Database (Denmark)

    Walther, J. H.; Popadic, A.; Koumoutsakos, P.

    We present continuum simulations of water flow past fullerene molecules. The governing Navier-Stokes equations are complemented with the Navier slip boundary condition with a slip length that is extracted from related molecular dynamics simulations. We find that several quantities of interest...... as computed by the present model are in good agreement with results from atomistic and atomistic-continuum simulations at a fraction of the computational cost. We simulate the flow past a single fullerene and an array of fullerenes and demonstrate that such nanoscale flows can be computed efficiently...

  10. Application of flow cytometry to monitor assimilable organic carbon (AOC) and microbial community changes in water.

    Science.gov (United States)

    Elhadidy, Ahmed M; Van Dyke, Michele I; Peldszus, Sigrid; Huck, Peter M

    2016-11-01

    Flow cytometry is an efficient monitoring tool for rapid cell counting, and can be applied to research on water quality and treatment. In this study, a method that employs flow cytometry and a natural microbial inoculum to determine assimilable organic carbon (AOC) was adapted for use with challenging surface waters that have a high organic and particle content, and subsequently applied in a long term river water study. AOC method optimization showed that river water bacteria could pass through a 0.2μm membrane filter, and therefore membrane filtration combined with heat treatment was required for sample sterilization. Preparation of the natural river inoculum with an acceptable yield value could only be achieved when grown using the natural water source, since growth was limited on different types of inorganic minimal media and in natural spring water. The resulting flow cytometry AOC method was reliable and reproducible, and results were comparable to the standard plate count AOC method. Size exclusion chromatography showed that both high and low molecular weight organic matter fractions were utilized by the natural AOC inoculum. Flow cytometry was used to measure both AOC levels and total cell counts in a long term study to monitor the water quality of a river which was used as a drinking water source. The method could distinguish between high nucleic acid (HNA) and low nucleic acid (LNA) groups of bacteria, and HNA bacteria were found to respond faster than LNA bacteria to seasonal changes in nutrients and water temperature. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Effects of flow and water chemistry on lead release rates from pipe scales.

    Science.gov (United States)

    Xie, Yanjiao; Giammar, Daniel E

    2011-12-01

    Lead release from pipe scales was investigated under different water compositions, stagnation times, and flow regimes. Pipe scales containing PbO(2) and hydrocerussite (Pb(3)(OH)(2)(CO(3))(2)) were developed on lead pipes by conditioning the pipes with water containing free chlorine for eight months. Water chemistry and the composition of the pipe scales are two key factors affecting lead release from pipe scales. The water rarely reached equilibrium with pipe scales within one day, which makes solid-water contact time and corrosion product dissolution rates the controlling factors of lead concentrations for the conditions tested. Among five water compositions studied, a solution with orthophosphate had the lowest dissolved lead release rate and highest particulate lead release rate. Free chlorine also decreased the dissolved lead release rate at stagnant conditions. Water flow increased rates of release of both dissolved and particulate lead by accelerating the mass transfer of lead out of the porous pipe scales and by physically destabilizing pipe scales. Dissolved lead comprised the majority of the lead released at both stagnant and laminar flow conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Nitrogen doping effect on flow-induced voltage generation from graphene-water interface

    Science.gov (United States)

    Okada, Takeru; Kalita, Golap; Tanemura, Masaki; Yamashita, Ichiro; Meyyappan, M.; Samukawa, Seiji

    2018-01-01

    Liquid-flow-induced generation of electricity using nanocarbons, particularly graphene-water interface, has received attention for energy harvesting. Here, we have obtained voltage generation from a single water droplet motion on graphene. We have investigated the effect of the graphene surface condition on flow-induced voltage generation, which is controlled by heteroatom doping. Nitrogen-doped graphene shows three times higher voltage generation compared to pristine graphene due to the doping-induced surface charge of graphene. Graphene surface potential tuning by doping is shown to play an important role in voltage generation.

  13. Martian base agriculture: The effect of low gravity on water flow, nutrient cycles, and microbial biomass dynamics

    Science.gov (United States)

    Maggi, Federico; Pallud, Céline

    2010-11-01

    The latest advances in bioregenerative strategies for long-term life support in extraterrestrial outposts such as on Mars have indicated soil-based cropping as an effective approach for waste decomposition, carbon sequestration, oxygen production, and water biofiltration as compared to hydroponics and aeroponics cropping. However, it is still unknown if cropping using soil systems could be sustainable in a Martian greenhouse under a gravity of 0.38 g. The most challenging aspects are linked to the gravity-induced soil water flow; because water is crucial in driving nutrient and oxygen transport in both liquid and gaseous phases, a gravitational acceleration lower than g = 9.806 m s -2 could lead to suffocation of microorganisms and roots, with concomitant emissions of toxic gases. The effect of Martian gravity on soil processes was investigated using a highly mechanistic model previously tested for terrestrial crops that couples soil hydraulics and nutrient biogeochemistry. Net leaching of NO3- solute, gaseous fluxes of NH 3, CO 2, N 2O, NO and N 2, depth concentrations of O 2, CO 2 and dissolved organic carbon (DOC), and pH in the root zone were calculated for a bioregenerative cropping unit under gravitational acceleration of Earth and for its homologous on Mars, but under 0.38 g. The two cropping units were treated with the same fertilizer type and rate, and with the same irrigation regime, but under different initial soil moisture content. Martian gravity reduced water and solute leaching by about 90% compared to Earth. This higher water holding capacity in soil under Martian gravity led to moisture content and nutrient concentrations that favoured the metabolism of various microbial functional groups, whose density increased by 5-10% on Mars as compared to Earth. Denitrification rates became substantially more important than on Earth and ultimately resulted in 60%, 200% and 1200% higher emissions of NO, N 2O and N 2 gases, respectively. Similarly, O 2 and DOC

  14. Water quality and quantity and simulated surface-water and groundwater flow in the Laurel Hill Creek Basin, southwestern Pennsylvania, 1991–2007

    Science.gov (United States)

    Galeone, Daniel G.; Risser, Dennis W.; Eicholtz, Lee W.; Hoffman, Scott A.

    2017-07-10

    central sections was 0.24 and 0.05 ft3/s/mi2, respectively. In general, as the drainage area increased for tributary basins, the streamflow per unit area increased.Criteria established by the Pennsylvania Department of Environmental Protection indicate that the safe yield of water withdrawals from the Laurel Hill Creek Basin is 1.43 million gallons per day (Mgal/d). Water-use data for 2009 indicate that net (water withdrawals subtracted by water discharges) water withdrawals from groundwater and surface-water sources in the basin were approximately 1.93 Mgal/d. Water withdrawals were concentrated in the upper part of the basin with approximately 80 percent of the withdrawals occurring in the upper 36 mi2 of the basin. Three subbasins—Allen Creek, Kooser Run, and Shafer Run— in the upper part were affected the most by water withdrawals such that safe yields were exceeded by more than 1,000 percent in the first two and more than 500 percent in the other. In the subbasin of Shafer Run, intermittent streamflow characterizes sections that historically have been perennial.The GSFLOW model of the Laurel Hill Creek Basin is a simple one-layer representation of the groundwater flow system. The GSFLOW model was primarily calibrated to reduce the error term associated with base-flow periods. The total amount of observed streamflow at the Laurel Hill Creek at Ursina, Pa. streamflow-gaging station and the simulated streamflow were within 0.1 percent over the entire modeled period; however, annual differences between simulated and observed streamflow showed a range of -27 to 24 percent from 1992 to 2007 with nine of the years having less than a 10-percent difference. The primary source of simulated streamflow in the GSFLOW model was the subsurface (interflow; 62 percent), followed by groundwater (25 percent) and surface runoff (13 percent). Most of the simulated subsurface flow that reached the stream was in the form of slow flow as opposed to preferential (fast) interflow.

  15. Factors influencing arsenic and nitrate removal from drinking water in a continuous flow electrocoagulation (EC) process.

    Science.gov (United States)

    Kumar, N Sanjeev; Goel, Sudha

    2010-01-15

    An experimental study was conducted under continuous flow conditions to evaluate some of the factors influencing contaminant removal by electrocoagulation (EC). A bench-scale simulation of drinking water treatment was done by adding a filtration column after a rectangular EC reactor. Contaminant removal efficiency was determined for voltages ranging from 10 to 25 V and a comparative study was done with distilled water and tap water for two contaminants: nitrate and arsenic(V). Maximum removal efficiency was 84% for nitrate at 25 V and 75% for arsenic(V) at 20 V. No significant difference in contaminant removal was observed in tap water versus distilled water. Increase in initial As(V) concentration from 1 ppm to 2 ppm resulted in a 10% increase in removal efficiency. Turbidity in the EC reactor effluent was 52 NTU and had to be filtered to achieve acceptable levels of final turbidity (5 NTU) at steady-state. The flow regime in the continuous flow reactor was also evaluated in a tracer study to determine whether it is a plug flow reactor (PFR) or constantly stirred tank reactor (CSTR) and the results show that this reactor was close to an ideal CSTR, i.e., it was fairly well-mixed.

  16. Water scarcity, groundwater and base flow in Dutch catchments: effects of climate and human impact

    Science.gov (United States)

    Hendriks, D. M. D.; van Ek, R.; Kuijper, M. J. M.

    2012-04-01

    During recent years (2003, 2006 en 2008) water boards in the Netherlands have had to cope with drought and water scarcity. Because of human impacts in the area, like groundwater abstraction and extensive drainage, the upper parts of streams run dry during low precipitation periods. The lack of water is a risk for the environmental flow needs of the streams. In addition, agricultural areas encounter problems due to low groundwater levels and limited availability of water for spray irrigation. Such problems are likely to occur more frequent in the future, because of increasing frequency of dry spells, reduced water intake possibilities from large rivers and a higher demand for water for agriculture and other land use functions. Several studies have been carried out to investigate the possibilities for structural improvement of groundwater and base flow conditions, thereby improving the situation of agriculture and ecology (Hendriks et al., 2010; Kuijper et al., 2012). The effects of both climate change and unsustainable use of water resources on base flow were assessed at various scales. For this purpose, spatially distributed groundwater models with fine meshed grids (25x25 m) were used to simultaneously assess the effects of climate and human impacts on both groundwater conditions and surface water discharge. Climatic effects were assessed by comparison of meteorologically dry and average years, as well as through climate scenarios from the Royal Dutch Weather Service (KNMI). Human impacts were assessed by modeling various scenarios with reduced or increased drainage and groundwater abstraction, including a scenario of the undisturbed situation. Also, the impact of stream morphology was studied. The suitability of a new modeling approach (Van der Velde et al., 2009), allowing a fast assessment of discharge with high accuracy, was tested to improve discharge simulations from groundwater models. Model results show that extensive drainage systems have a large impact

  17. Global network of embodied water flow by systems input-output simulation

    Science.gov (United States)

    Chen, Zhanming; Chen, Guoqian; Xia, Xiaohua; Xu, Shiyun

    2012-09-01

    The global water resources network is simulated in the present work for the latest target year with statistical data available and with the most detailed data disaggregation. A top-down approach of systems inputoutput simulation is employed to track the embodied water flows associated with economic flows for the globalized economy in 2004. The numerical simulation provides a database of embodied water intensities for all economic commodities from 4928 producers, based on which the differences between direct and indirect water using efficiencies at the global scale are discussed. The direct and embodied water uses are analyzed at continental level. Besides, the commodity demand in terms of monetary expenditure and the water demand in terms of embodied water use are compared for the world as well as for three major water using regions, i.e., India, China, and the United States. Results show that food product contributes to a significant fraction for water demand, despite the value varies significantly with respect to the economic status of region.

  18. Design and numerical simulation on an auto-cumulative flowmeter in horizontal oil-water two-phase flow

    Science.gov (United States)

    Xie, Beibei; Kong, Lingfu; Kong, Deming; Kong, Weihang; Li, Lei; Liu, Xingbin; Chen, Jiliang

    2017-11-01

    In order to accurately measure the flow rate under the low yield horizontal well conditions, an auto-cumulative flowmeter (ACF) was proposed. Using the proposed flowmeter, the oil flow rate in horizontal oil-water two-phase segregated flow can be finely extracted. The computational fluid dynamics software Fluent was used to simulate the fluid of the ACF in oil-water two-phase flow. In order to calibrate the simulation measurement of the ACF, a novel oil flow rate measurement method was further proposed. The models of the ACF were simulated to obtain and calibrate the oil flow rate under different total flow rates and oil cuts. Using the finite-element method, the structure of the seven conductance probes in the ACF was simulated. The response values for the probes of the ACF under the conditions of oil-water segregated flow were obtained. The experiments for oil-water segregated flow under different heights of the oil accumulation in horizontal oil-water two-phase flow were carried out to calibrate the ACF. The validity of the oil flow rate measurement in horizontal oil-water two-phase flow was verified by simulation and experimental results.

  19. Design and numerical simulation on an auto-cumulative flowmeter in horizontal oil-water two-phase flow.

    Science.gov (United States)

    Xie, Beibei; Kong, Lingfu; Kong, Deming; Kong, Weihang; Li, Lei; Liu, Xingbin; Chen, Jiliang

    2017-11-01

    In order to accurately measure the flow rate under the low yield horizontal well conditions, an auto-cumulative flowmeter (ACF) was proposed. Using the proposed flowmeter, the oil flow rate in horizontal oil-water two-phase segregated flow can be finely extracted. The computational fluid dynamics software Fluent was used to simulate the fluid of the ACF in oil-water two-phase flow. In order to calibrate the simulation measurement of the ACF, a novel oil flow rate measurement method was further proposed. The models of the ACF were simulated to obtain and calibrate the oil flow rate under different total flow rates and oil cuts. Using the finite-element method, the structure of the seven conductance probes in the ACF was simulated. The response values for the probes of the ACF under the conditions of oil-water segregated flow were obtained. The experiments for oil-water segregated flow under different heights of the oil accumulation in horizontal oil-water two-phase flow were carried out to calibrate the ACF. The validity of the oil flow rate measurement in horizontal oil-water two-phase flow was verified by simulation and experimental results.

  20. Interactive effects of water table and precipitation on net CO2 assimilation of three co-occurring Sphagnum mosses differing in distribution above the water table

    NARCIS (Netherlands)

    Robroek, B.J.M.; Schouten, M.G.C.; Limpens, J.; Berendse, F.; Poorter, H.

    2009-01-01

    Sphagnum cuspidatum, S. magellanicum and S. rubellum are three co-occurring peat mosses, which naturally have a different distribution along the microtopographical gradient of the surface of peatlands. We set out an experiment to assess the interactive effects of water table (low: -10 cm and high:

  1. System design and treatment efficiency of a surface flow constructed wetland receiving runoff impacted stream water.

    Science.gov (United States)

    Maniquiz, M C; Choi, J Y; Lee, S Y; Kang, C G; Yi, G S; Kim, L H

    2012-01-01

    This study reported the efficiency of a free water surface flow constructed wetland (CW) system that receives runoff impacted stream water from a forested and agricultural watershed. Investigations were conducted to examine the potential effect of hydraulic fluctuations on the CW as a result of storm events and the changes in water quality along the flow path of the CW. Based on the results, the incoming pollutant concentrations were increased during storm events and greater at the near end of the storm than at the initial time of storm. A similar trend was observed to the concentrations exiting the CW due to the wetland being a relatively small percentage of the watershed (time during storm events. The concentrations of most pollutants were significantly reduced (p retention of most pollutants during storm events as the actual water quality of the outflow was significantly better by 21-71% than the inflow and the levels of pollutants were reduced to appreciable levels.

  2. Experimental study on the flow regimes and pressure gradients of air-oil-water three-phase flow in horizontal pipes.

    Science.gov (United States)

    Al-Hadhrami, Luai M; Shaahid, S M; Tunde, Lukman O; Al-Sarkhi, A

    2014-01-01

    An experimental investigation has been carried out to study the flow regimes and pressure gradients of air-oil-water three-phase flows in 2.25 ID horizontal pipe at different flow conditions. The effects of water cuts, liquid and gas velocities on flow patterns and pressure gradients have been studied. The experiments have been conducted at 20 °C using low viscosity Safrasol D80 oil, tap water and air. Superficial water and oil velocities were varied from 0.3 m/s to 3 m/s and air velocity varied from 0.29 m/s to 52.5 m/s to cover wide range of flow patterns. The experiments were performed for 10% to 90% water cuts. The flow patterns were observed and recorded using high speed video camera while the pressure drops were measured using pressure transducers and U-tube manometers. The flow patterns show strong dependence on water fraction, gas velocities, and liquid velocities. The observed flow patterns are stratified (smooth and wavy), elongated bubble, slug, dispersed bubble, and annular flow patterns. The pressure gradients have been found to increase with the increase in gas flow rates. Also, for a given superficial gas velocity, the pressure gradients increased with the increase in the superficial liquid velocity. The pressure gradient first increases and then decreases with increasing water cut. In general, phase inversion was observed with increase in the water cut. The experimental results have been compared with the existing unified Model and a good agreement has been noticed.

  3. Flow Patterns Transition Law of Oil-Water Two-Phase Flow under a Wide Range of Oil Phase Viscosity Condition

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2013-01-01

    Full Text Available A systematic work on the prediction of flow patterns transition of the oil-water two-phase flows is carried out under a wide range of oil phase viscosities, where four main flow regimes are considered including stratified, dispersed, core-annular, and intermittent flow. For oil with a relatively low viscosity, VKH criterion is considered for the stability of stratified flow, and critical drop size model is distinguished for the transition of o/w and w/o dispersed flow. For oil with a high viscousity, boundaries of core-annular flow are based on criteria proposed by Bannwart and Strazza et al. and neutral stability law ignoring that the velocity of the viscous phase is introduced for stratified flow. Comparisons between predictions and quantities of available data in both low and high viscosity oil-water flow from literatures show a good agreement. The framework provides extensive information about flow patterns transition of oil-water two-phase flow for industrial application.

  4. Standardization of flow cytometry in myelodysplastic syndromes: a report from an international consortium and the European LeukemiaNet Working Group.

    NARCIS (Netherlands)

    Westers, T.M.; Ireland, R.; Kern, W.; Alhan, C.; Balleisen, J.S.; Bettelheim, P.; Burbury, K.; Cullen, M.; Cutler, J.A.; Porta, M.G. Della; Drager, A.M.; Feuillard, J.; Font, P.; Germing, U.; Haase, D.; Johansson, U.; Kordasti, S.; Loken, M.R.; Malcovati, L.; Marvelde, J.G. Te; Matarraz, S.; Milne, T.; Moshaver, B.; Mufti, G.J.; Ogata, K.; Orfao, A.; Porwit, A.; Psarra, K.; Richards, S.J.; Subira, D.; Tindell, V.; Vallespi, T.; Valent, P.; Velden, V.H. van der; Witte, T.J.M. de; Wells, D.A.; Zettl, F.; Bene, M.C.; Loosdrecht, A.A. van de

    2012-01-01

    Flow cytometry (FC) is increasingly recognized as an important tool in the diagnosis and prognosis of myelodysplastic syndromes (MDS). However, validation of current assays and agreement upon the techniques are prerequisites for its widespread acceptance and application in clinical practice.

  5. 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

    2017-01-01

    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.

  6. Impact and Mitigation of Nutrient Pollution and Overland Water Flow Change on the Florida Everglades, USA

    OpenAIRE

    Kristin Schade-Poole; Gregory Möller

    2016-01-01

    A subtropical watershed and wetland covering nearly 47,000 km2 in the southeastern United States, the Florida Everglades is a degraded, human-dominated environment. As a unique and important ecosystem, the Everglades provide a variety of important environmental services for society and nature. Over the past century and a half, anthropogenic actions have severely impacted the Everglades by disrupting the natural water flow and causing water pollution. As a result, the native flora and fauna ha...

  7. On calculation of a steam-water flow in a geothermal well

    Science.gov (United States)

    Shulyupin, A. N.; Chermoshentseva, A. A.

    2013-08-01

    Approaches to calculation of a steam-water flow in a geothermal well are considered. For hydraulic applications, a WELL-4 model of a steam-water well is developed. Data obtained using this model are compared with experimental data and also with calculations by similar models including the well-known HOLA model. The capacity of the A-2 well in the Mutnovskoe flash-steam field (Kamchatka half-island, Russia) after planned reconstruction is predicted.

  8. Ultrabroadband THz Time-Domain Spectroscopy of a Free-Flowing Water Film

    DEFF Research Database (Denmark)

    Wang, Tianwu; Pedersen, Pernille Klarskov; Jepsen, Peter Uhd

    2014-01-01

    of liquid water using two different THz-TDS setups. The extracted absorption coefficient and refractive index of water are in agreement with previous results reported in the literature. With this we show that the thin free-flowing liquid film is a versatile tool for windowless, ultrabroadband THz......-TDS with sub-100-femtosecond time resolution of aqueous solutions in transmission mode in the important cross-over region between vibrational and relaxational dynamics....

  9. Some geological implications of the flow of clay-water mixtures

    OpenAIRE

    Rocco, Stefano

    2017-01-01

    This thesis investigates three problems in the general area of environmental fluid mechanics. The first two problems are related to liquid or gas flow through clay-water suspensions, with relevance for the underground storage of radioactive waste and also for understanding the mechanism of eruption in mud volcanoes. The third problem centres on the different problem of mixing in a turbulent buoyant plume. First, the injection of gas and water from a central source into a two-dimensional l...

  10. In-pipe water quality monitoring in water supply systems under steady and unsteady state flow conditions: a quantitative assessment.

    Science.gov (United States)

    Aisopou, Angeliki; Stoianov, Ivan; Graham, Nigel J D

    2012-01-01

    Monitoring the quality of drinking water from the treatment plant to the consumers tap is critical to ensure compliance with national standards and/or WHO guideline levels. There are a number of processes and factors affecting the water quality during transmission and distribution which are little understood. A significant obstacle for gaining a detailed knowledge of various physical and chemical processes and the effect of the hydraulic conditions on the water quality deterioration within water supply systems is the lack of reliable and low-cost (both capital and O & M) water quality sensors for continuous monitoring. This paper has two objectives. The first one is to present a detailed evaluation of the performance of a novel in-pipe multi-parameter sensor probe for reagent- and membrane-free continuous water quality monitoring in water supply systems. The second objective is to describe the results from experimental research which was conducted to acquire continuous water quality and high-frequency hydraulic data for the quantitative assessment of the water quality changes occurring under steady and unsteady-state flow conditions. The laboratory and field evaluation of the multi-parameter sensor probe showed that the sensors have a rapid dynamic response, average repeatability and unreliable accuracy. The uncertainties in the sensor data present significant challenges for the analysis and interpretation of the acquired data and their use for water quality modelling, decision support and control in operational systems. Notwithstanding these uncertainties, the unique data sets acquired from transmission and distribution systems demonstrated the deleterious effect of unsteady state flow conditions on various water quality parameters. These studies demonstrate: (i) the significant impact of the unsteady-state hydraulic conditions on the disinfectant residual, turbidity and colour caused by the re-suspension of sediments, scouring of biofilms and tubercles from the

  11. Experimental study of ionic liquid-water flow in T-shaped microchannels with different aspect ratios

    Science.gov (United States)

    Yagodnitsyna, A. A.; Kovalev, A. V.; Bilsky, A. V.

    2017-09-01

    Flow regimes of immiscible ionic liquid - water flow in T-shaped microchannels with 160 um hydraulic diameter and 1:2 and 1:4 aspect ratios are experimentally studied in the present work. Plug length and velocity were measured using high-speed visualization of the flow. Flow pattern maps were drawn for two channels. Parallel flow was shown to prevail for 1:4 aspect ratio channel in comparison to 1:2.

  12. Impact and Mitigation of Nutrient Pollution and Overland Water Flow Change on the Florida Everglades, USA

    Directory of Open Access Journals (Sweden)

    Kristin Schade-Poole

    2016-09-01

    Full Text Available A subtropical watershed and wetland covering nearly 47,000 km2 in the southeastern United States, the Florida Everglades is a degraded, human-dominated environment. As a unique and important ecosystem, the Everglades provide a variety of important environmental services for society and nature. Over the past century and a half, anthropogenic actions have severely impacted the Everglades by disrupting the natural water flow and causing water pollution. As a result, the native flora and fauna have been displaced, important habitats have been lost, invasive species have become prevalent, and water contaminant concentrations have increased. Accelerating efforts are being made towards preserving the Everglades ecosystem by restoring water flow and improving water quality. To explore this complex and important aquatic ecosystem, we critically review the relevant environmental history, major terrestrial and aquatic characteristics and dynamics, engineered changes to water flow, major sources and impacts of nutrient pollution, trends in system response to pollution and mitigation actions, and recent regulatory efforts driving restoration.

  13. Decomposition behavior of hemicellulose and lignin in the step-change flow rate liquid hot water.

    Science.gov (United States)

    Zhuang, Xinshu; Yu, Qiang; Wang, Wen; Qi, Wei; Wang, Qiong; Tan, Xuesong; Yuan, Zhenhong

    2012-09-01

    Hemicellulose and lignin are the main factors limiting accessibility of hydrolytic enzymes besides the crystallinity of cellulose. The decomposition behavior of hemicellulose and lignin in the step-change flow rate hot water system was investigated. Xylan removal increased from 64.53% for batch system (solid concentration 4.25% w/v, 18 min, 184°C) to 83.78% at high flow rates of 30 ml/min for 8 min, and then 10 ml/min for 10 min. Most of them (80-90%) were recovered as oligosaccharide. It was hypothesized that the flowing water could enhance the mass transfer to improve the sugars recovery. In addition, the solubilization mechanism of lignin in the liquid hot water was proposed according to the results of Fourier transform-infrared spectroscopy and scanning electron microscopy of the water-insoluble fraction and gas chromatography-mass spectrometry of the water-soluble fraction. It was proposed that lignin in the liquid hot water first migrated out of the cell wall in the form of molten bodies, and then flushed out of the reactor. A small quantity of them was further degraded into monomeric products such as vanillin, syringe aldehyde, coniferyl aldehyde, ferulic acid, and p-hydroxy-cinnamic acid. All of these observations would provide important information for the downstream processing, such as purification and concentration of sugars and the enzymatic digestion of residual solid.

  14. Ground-Water Flow, 2004-07, and Water Quality, 1992-2007, in McBaine Bottoms, Columbia, Missouri

    Science.gov (United States)

    Smith, Brenda Joyce; Richards, Joseph M.

    2008-01-01

    The U.S. Geological Survey, in cooperation with the city of Columbia, Missouri, and the Missouri Department of Conservation, collected ground-water quality data, surface-water quality data, and water-level data in McBaine Bottoms, southwest of Columbia. McBaine Bottoms, adjacent to the Missouri River, is the location of the municipal-supply well field for the city of Columbia, the city of Columbia wastewater-treatment wetlands, and the Missouri Department of Conservation Eagle Bluffs Conservation Area. This report describes the ground-water flow and water quality of McBaine Bottoms and provides information to better understand the interaction between treated effluent from the wetlands used on the Eagle Bluffs Conservation Area and the water in the alluvial aquifer that is pumped from the city of Columbia municipal-supply well field. Changes in major chemical constituent concentrations have been detected at several sampling sites between pre- and post-effluent application data. Analysis of post-effluent data indicates substantial changes in calcium, potassium, sodium, chloride, and sulfate concentrations in ground water. These changes became apparent shortly after the beginning of the operation of the wastewater-treatment wetland in 1994 and the formation of the Eagle Bluffs Conservation Area, which uses the treated effluent as a water source for the management of migratory water fowl. The changes have continued throughout the 15 years of sample collection. The concentrations of these major chemical constituents are on the mixing continuum between pre-effluent ground water as one end member and the treated wastewater effluent as the other end member. For monitoring wells that had changes in major chemical constituent concentrations, the relative percentage of treated effluent in the ground water, assuming chloride is conservative, ranged from 6 to 88 percent. Twenty-two monitoring wells throughout McBaine Bottoms have been affected by effluent based on chloride

  15. Water flow and multicomponent solute transport in drip-irrigated lysimeters

    Science.gov (United States)

    Raij, Iael; Šimůnek, Jiří; Ben-Gal, Alon; Lazarovitch, Naftali

    2016-08-01

    Controlled experiments and modeling are crucial components in the evaluation of the fate of water and solutes in environmental and agricultural research. Lysimeters are commonly used to determine water and solute balances and assist in making sustainable decisions with respect to soil reclamation, fertilization, or irrigation with low-quality water. While models are cost-effective tools for estimating and preventing environmental damage by agricultural activities, their value is highly dependent on the accuracy of their parameterization, often determined by calibration. The main objective of this study was to use measured major ion concentrations collected from drip-irrigated lysimeters to calibrate the variably saturated water flow model HYDRUS (2D/3D) coupled with the reactive transport model UNSATCHEM. Irrigation alternated between desalinated and brackish waters. Lysimeter drainage and soil solution samples were collected for chemical analysis and used to calibrate the model. A second objective was to demonstrate the potential use of the calibrated model to evaluate lower boundary design options of lysimeters with respect to leaching fractions determined using drainage water fluxes, chloride concentrations, and overall salinity of drainage water, and exchangeable sodium percentage (ESP) in the profile. The model showed that, in the long term, leaching fractions calculated with electrical conductivity values would be affected by the lower boundary condition pressure head, while those calculated with chloride concentrations and water fluxes would not be affected. In addition, clear dissimilarities in ESP profiles were found between lysimeters with different lower boundary conditions, suggesting a potential influence on hydraulic conductivities and flow patterns.

  16. Surface-flow wetland for water reclamation at Batamindo Industrial Park

    Directory of Open Access Journals (Sweden)

    Salim Chris

    2017-01-01

    Full Text Available The reclamation of wastewater as clean water resource is essential in the concept of water conservation. In industries, this will also lead to overall plant operational cost reduction. In this study, a pilot-scale surface-flow constructed wetland system filled with water hyacinth was used to treat effluent from existing sewage treatment plant at Batamindo Industrial Park. The sewage treatment plant effluent with quality fulfilling the regulation of Indonesian Ministry of Environment No.5/2014/XLVII-Group I was treated further to meet the raw water quality standard of Class I defined by Indonesian Government Regulation No.82/2001 as potable water resource. The system was able to maintain high chemical oxygen demand removal efficiency of around 80% from initial value of 100 mg/L in sewage treatment plant effluent despite the change of flow rate from 10 to 40 m3/day (corresponding to hydraulic retention time of 2 to 0.5 days in constructed wetland respectively. The constructed wetland could successfully increase dissolved oxygen concentration, remove coliform bacteria and improve clarity (reduce turbidity of water while maintaining neutral pH and low TSS values. Some additional post-treatments such as simple aeration and ultraviolet irradiation may improve the water quality further to meet the Class I Standard of potable water resource.

  17. A Hydrological Concept including Lateral Water Flow Compatible with the Biogeochemical Model ForSAFE

    Directory of Open Access Journals (Sweden)

    Giuliana Zanchi

    2016-03-01

    Full Text Available The study presents a hydrology concept developed to include lateral water flow in the biogeochemical model ForSAFE. The hydrology concept was evaluated against data collected at Svartberget in the Vindeln Research Forest in Northern Sweden. The results show that the new concept allows simulation of a saturated and an unsaturated zone in the soil as well as water flow that reaches the stream comparable to measurements. The most relevant differences compared to streamflow measurements are that the model simulates a higher base flow in winter and lower flow peaks after snowmelt. These differences are mainly caused by the assumptions made to regulate the percolation at the bottom of the simulated soil columns. The capability for simulating lateral flows and a saturated zone in ForSAFE can greatly improve the simulation of chemical exchange in the soil and export of elements from the soil to watercourses. Such a model can help improve the understanding of how environmental changes in the forest landscape will influence chemical loads to surface waters.

  18. A detailed characterization of viscous oil-water flows downward sudden contractions in horizontal pipes

    Science.gov (United States)

    Colombo, Luigi P. M.; Guilizzoni, Manfredo; Sotgia, Giorgio

    2014-11-01

    Two-phase flows of viscous oil and water through singularities such as sudden area contractions/expansions have been taken into limited consideration in the relevant scientific literature. Nevertheless, they play a role of primary importance in industrial systems, for instance, but not only, in the exploitation of oil wells and pipelines. The proposed work is based on the comparison of photographic images of the flow patterns taken from three points of view, i.e. upper, lower and frontal, thanks to a couple of mirrors ±45° inclined with respect to the horizontal plane. Oil-water flow regimes have been observed both upward and downward of five horizontal test sections with diameter ratios d/D = 40/50, 30/50, 30/40, respectively. The observed structures of the oil-water interface, especially for core-annular flows, has suggested also detecting flow patterns in a 30 mm straight pipe for sake of comparison. Actually, the shape of the oil-core interface appears significantly influenced by the sharp-edged area change as well as by the expected momentum variation.

  19. Technical feasibility study for the D-T neutron monitor using activation of the flowing water

    Energy Technology Data Exchange (ETDEWEB)

    Uno, Yoshitomo; Kaneko, Junichi; Nishitani, Takeo; Maekawa, Fujio; Tanaka, Teruya; Ikeda, Yujiro; Takeuchi, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-03-01

    The experimental study of technical feasibility for the D-T neutron monitor using activation of the flowing water was performed at FNS/JAERI as the ITER/EDA R and D Task T499. The temporal resolution for pulsed neutrons was measured and dependence of the temporal resolution on flowing velocity was studied. The temporal resolution of 50 ms that is better than 100 ms of the requirement for ITER was achieved. We found that the temporal resolution is determined by a turbulent dispersion of the flow. The experiment for validation of the method determining the absolute D-T neutron flux was carried out by using the stainless steel (SS 316)/Water assembly to simulate the neutron field in the blanket region of ITER. The neutron emission rate measured with the water activation has a good agreement with that with the neutron yield monitor with associated {alpha} detector, and this technique shows the accuracy of the absolute neutron flux better than 10%. At the application on ITER-FEAT, the neutron activation with fluid flow has a dynamic range of 50 kW - 500 MW operation with a temporal resolution of 78 ms at the flow velocity of 10 m/s. (author)

  20. Cerberus Fossae and Elysium Planitia Lavas, Mars: Source Vents, Flow Rates, Edifice Styles and Water Interactions

    Science.gov (United States)

    Sakimoto, S. E. H.; Gregg, T. K. P.

    2004-01-01

    The Cerberus Fossae and Elysium Planitia regions have been suggested as some of the youngest martian surfaces since the Viking mission, although there was doubt whether the origins were predominantly volcanic or fluvial. The Mars Global Surveyor and Mars Odyssey Missions have shown that the region is certainly young in terms of the topographic preservation and the youthful crater counts (e.g. in the tens to a few hundred million yrs.). Numerous authors have shown that fluvial and volcanic features share common flow paths and vent systems, and that there is evidence for some interaction between the lava flows and underlying volatiles as well as the use by lavas and water of the same vent system. Given the youthful age and possible water-volcanism interaction environment, we'd like constraints on water and volcanic flux rates and interactions. Here, we model ranges of volcanic flow rates where we can well-constrain them, and consider the modest flow rate results results in context with local eruption styles, and track vent locations, edifice volumes, and flow sources and data.