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Sample records for runner advanced hydropower

  1. Development of a more fish tolerant turbine runner advanced hydropower turbine project. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Cook, T.C.; Hecker, G.E. [Worcester Polytechnic Inst., Holden, MA (United States). Alden Research Lab.; Faulkner, H.B.; Jansen, W. [Northern Research and Engineering Corp., Cambridge, MA (United States)

    1997-01-01

    The Hidrostal pump is a single bladed combined screw/centrifugal pump which has been proven to transport fish with minimal injury. The focus of the ARL/NREC research project was to develop a new runner geometry which is effective in downstream fish passage and hydroelectric power generation. A flow of 1,000 cfs and a head in the range of 75 ft to 100 ft were selected for conceptual design of the new runner. Criteria relative to hydraulic characteristics which are favorable for fish passage were prepared based on a reassessment of the available information. Important criteria used to develop the new runner design included low pressure change rates, minimum absolute pressures, and minimum shear. Other criteria which are reflected in the runner design are a minimum number of blades (only two), minimum total length of leading edges, and large flow passages. Flow characteristics of the new runner were analyzed using two- dimensional and three-dimensional Computational Fluid Dynamic (CFD) models. The basic runner geometry was initially selected using the two-dimensional model. The three-dimensional model was used to investigate the flow characteristics in detail through the entire runner and to refine the design by eliminating potential problem areas at the leading and trailing edges. Results of the analyses indicated that the runner has characteristics which should provide safe fish passage with an overall power efficiency of approximately 90%. The size of the new runner, which is larger than conventional turbine runners with the same design flow and head, will provide engineering, fabrication, and installation.challenges related to the turbine components and the civil works. A small reduction in the overall efficiency would reduce the size of the runner considerably, would simplify the turbine manufacturing operations, and would allow installation of the new turbine at more hydroelectric sites.

  2. Development of a more fish-tolerant turbine runner, advanced hydropower turbine project

    Energy Technology Data Exchange (ETDEWEB)

    Cook, T.C.; Hecker, G.E. [Worcester Polytechnic Inst., Holden, MA (United States). Alden Research Lab.; Faulkner, H.B.; Jansen, W. [Northern Research and Engineering Corp., Woburn, MA (United States)

    1997-02-01

    Alden Research Laboratory, Inc. (ARL) and Northern Research and Engineering Corporation (NREC) conducted a research program to develop a turbine runner which will minimize fish injury and mortality at hydroelectric projects. ARL?NREC have developed a runner shape which minimizes the number of blade leading edges, reduces the pressure versus time and the velocity versus distance gradients within the runner, minimizes or eliminates the clearance between the runner and runner housing, and maximizes the size of the flow passages, all with minimal penalty on turbine efficiency. An existing pump impeller provided the starting point for developing the fish tolerant turbine runner. The Hidrostal pump is a single bladed combined screw/centrifugal pump which has been proven to transport fish with minimal injury. The focus of the ARL/NREC research project was to develop a new runner geometry which is effective in downstream fish passage and hydroelectric power generation. A flow of 1,000 cfs and a head in the range of 75 ft to 100 ft were selected for conceptual design of the new runner. Conceptual design of the new runner began with a re-evaluation of studies which have been previously conducted to identify probable sources of injury to fish passing through hydraulic turbines. Criteria relative to hydraulic characteristics which are favorable for fish passage were prepared based on a reassessment of the available information. Important criteria used to develop the new runner design included low pressure change rates, minimum absolute pressures, and minimum shear. Other criteria which are reflected in the runner design are a minimum number of blades (only two), minimum total length of leading edges, and large flow passages. 86 figs., 5 tabs.

  3. Hydropower

    DEFF Research Database (Denmark)

    Fenhann, Jørgen Villy; Kofoed, Jens Peter

    2010-01-01

    This chapter gives an overview of the various forms of hydropower: conventional hydropower, marine currents, tides, power from salinity gradients, ocean thermal energy conversion and wave power.......This chapter gives an overview of the various forms of hydropower: conventional hydropower, marine currents, tides, power from salinity gradients, ocean thermal energy conversion and wave power....

  4. Advanced hydropower turbine: AHTS-Advanced Hydropower Turbine System Program; Turbinas hidraulicas avancadas: Programa AHTS-Advanced Hydropower Turbine System

    Energy Technology Data Exchange (ETDEWEB)

    Macorin, Adriano De Figueiredo; Tomisawa, Alessandra Terumi; Van Deursen, Gustavo Jose Ferreira; Bermann, Celio [Universidade de Sao Paulo (USP), SP (Brazil)], email: brunosilva@usp.br

    2010-07-01

    Due to a privileged hydrography and energy policies that remounts to the beginning of the 20th century, Brazilian's electrical grid can be considered one of the cleanest in the world regarding the emission of atmospheric pollutants. Nevertheless, as in every human large enterprise, it is well known that hydroelectric power plants also lead to harmful environmental impacts. This article presents the AHTS Program (Advanced Hydropower Turbine System) started in 1994 in USA and developed to assess and conceive new hydro turbines to mitigate two of the main negative impacts of the installation and operation of this kind of power plant: (a) turbine-passed fish mortality and (b) the low dissolved oxygen - DO - levels downstream of the dams. The criteria used to concept the turbines are also justified in this article. As well as the modifications made in each case by the following companies: Alden Research Lab e o Northern Research and Engineering Corporation (ARL/NREC) and Voith Hydro (Voith). (author)

  5. Hydropower

    CSIR Research Space (South Africa)

    Jonker Klunne, W

    2012-10-01

    Full Text Available —that is not consumed in the process, it is, in principle, a renewable form of energy. The use of hydropower can make a contribution to saving exhaustible energy sources such as fossil fuels....

  6. Fish Passage Assessment of an Advanced Hydropower Turbine and Conventional Turbine Using Blade-Strike Modeling

    Directory of Open Access Journals (Sweden)

    Zhiqun Deng

    2011-01-01

    Full Text Available Hydropower is the largest renewable energy source in the world. However, in the Columbia and Snake River basins, several species of Pacific salmon and steelhead have been listed for protection under the Endangered Species Act due to significant declines of fish population. Dam operators and design engineers are thus faced with the task of making hydroelectric facilities more fish friendly through changes in hydro-turbine design and operation. Public Utility District No. 2 of Grant County, Washington, applied for relicensing from the U.S. Federal Energy Regulatory Commission to replace the 10 turbines at Wanapum Dam with advanced hydropower turbines that were designed to increase power generation and improve fish passage conditions. We applied both deterministic and stochastic blade-strike models to compare fish passage performance of the newly installed advanced turbine to an existing turbine. Modeled probabilities were compared to the results of a large-scale live-fish survival study and a Sensor Fish study under the same operational parameters. Overall, injury rates predicted by the deterministic model were higher than experimental rates of injury, while those predicted by the stochastic model were in close agreement with experimental results. Fish orientation at the time of entry into the plane of the leading edges of the turbine runner blades was an important factor contributing to uncertainty in modeled results. The advanced design turbine had slightly higher modeled injury rates than the existing turbine design; however, no statistical evidence suggested significant differences in blade-strike injuries between the two turbines, thus the hypothesis that direct fish survival rate through the advanced hydropower turbine is equal to or higher than that for fish passing through the conventional turbine could not be rejected.

  7. Fish passage assessment of an advanced hydropower turbine and conventional turbine using blade-strike modeling

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Z.; Carlson, T. J.; Dauble, D. D.; Ploskey, G. R. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States)

    2011-07-01

    Hydropower is the largest renewable energy source in the world. However, in the Columbia and Snake River basins, several species of Pacific salmon and steelhead have been listed for protection under the Endangered Species Act due to significant declines of fish population. Dam operators and design engineers are thus faced with the task of making hydroelectric facilities more fish friendly through changes in hydro-turbine design and operation. Public Utility District No. 2 of Grant County, Washington, applied for relicensing from the U.S. Federal Energy Regulatory Commission to replace the 10 turbines at Wanapum Dam with advanced hydropower turbines that were designed to increase power generation and improve fish passage conditions. We applied both deterministic and stochastic blade-strike models to compare fish passage performance of the newly installed advanced turbine to an existing turbine. Modeled probabilities were compared to the results of a large-scale live-fish survival study and a Sensor Fish study under the same operational parameters. Overall, injury rates predicted by the deterministic model were higher than experimental rates of injury, while those predicted by the stochastic model were in close agreement with experimental results. Fish orientation at the time of entry into the plane of the leading edges of the turbine runner blades was an important factor contributing to uncertainty in modeled results. The advanced design turbine had slightly higher modeled injury rates than the existing turbine design; however, no statistical evidence suggested significant differences in blade-strike injuries between the two turbines, thus the hypothesis that direct fish survival rate through the advanced hydropower turbine is equal to or higher than that for fish passing through the conventional turbine could not be rejected. (authors)

  8. Advanced Pumped Storage Hydropower and Ancillary Services Provision

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, Eduard; Gevorgian, Vahan; Mohanpurkar, Manish; Luo, Yusheng; Hovsapian, Rob; Koritarov, Vladimir

    2017-07-12

    This paper presents a high-level overview of the capability of advanced pumped storage hydropower to provide ancillary services including frequency regulation and oscillation damping. Type 3 and Type 4 generators are discussed. The examples given are for a small power system that uses a diesel generator as the main generator and a very large system that uses a gas turbine as the main generator.

  9. Fish Passage Assessment of an Advanced Hydropower Turbine and Conventional Turbine Using Blade-strike Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Zhiqun; Carlson, Thomas J.; Dauble, Dennis D.; Ploskey, Gene R.

    2011-01-04

    In the Columbia and Snake River basins, several species of Pacific salmon were listed under the Endangered Species Act of 1973 due to significant declines of fish population. Dam operators and design engineers are thus faced with the task of making those hydroelectric facilities more ecologically friendly through changes in hydro-turbine design and operation. Public Utility District No. 2 of Grant County, Washington, applied for re-licensing from the U.S. Federal Energy Regulatory Commission to replace the 10 turbines at Wanapum Dam with advanced hydropower turbines that were designed to increase power generation and improve fish passage conditions. We applied both deterministic and stochastic blade-strike models to the newly installed turbine and an existing turbine. Modeled probabilities were compared to the results of a large-scale live fish survival study and a sensor fish study under the same operational parameters. Overall, injury rates predicted by the deterministic model were higher than experimental rates of injury while those predicted by the stochastic model were in close agreement with experiment results. Fish orientation at the time of entry into the plane of the leading edges of the turbine runner blades was an important factor contributing to uncertainty in modeled results. The advanced design turbine had slightly higher modeled injury rates than the existing turbine design; however, there was no statistical evidence that suggested significant differences in blade-strike injuries between the two turbines and the hypothesis that direct fish survival rate through the advanced hydropower turbine is equal or better than that through the conventional turbine could not be rejected.

  10. Development of environmentally advanced hydropower turbine system design concepts

    Energy Technology Data Exchange (ETDEWEB)

    Franke, G.F.; Webb, D.R.; Fisher, R.K. Jr. [Voith Hydro, Inc. (United States)] [and others

    1997-08-01

    A team worked together on the development of environmentally advanced hydro turbine design concepts to reduce hydropower`s impact on the environment, and to improve the understanding of the technical and environmental issues involved, in particular, with fish survival as a result of their passage through hydro power sites. This approach brought together a turbine design and manufacturing company, biologists, a utility, a consulting engineering firm and a university research facility, in order to benefit from the synergy of diverse disciplines. Through a combination of advanced technology and engineering analyses, innovative design concepts adaptable to both new and existing hydro facilities were developed and are presented. The project was divided into 4 tasks. Task 1 investigated a broad range of environmental issues and how the issues differed throughout the country. Task 2 addressed fish physiology and turbine physics. Task 3 investigated individual design elements needed for the refinement of the three concept families defined in Task 1. Advanced numerical tools for flow simulation in turbines are used to quantify characteristics of flow and pressure fields within turbine water passageways. The issues associated with dissolved oxygen enhancement using turbine aeration are presented. The state of the art and recent advancements of this technology are reviewed. Key elements for applying turbine aeration to improve aquatic habitat are discussed and a review of the procedures for testing of aerating turbines is presented. In Task 4, the results of the Tasks were assembled into three families of design concepts to address the most significant issues defined in Task 1. The results of the work conclude that significant improvements in fish passage survival are achievable.

  11. Advanced inflow forecasting for a hydropower plant in an Alpine hydropower regulated catchment - coupling of operational and hydrological forecasts

    Science.gov (United States)

    Tilg, Anna-Maria; Schöber, Johannes; Huttenlau, Matthias; Messner, Jakob; Achleitner, Stefan

    2017-04-01

    Hydropower is a renewable energy source which can help to stabilize fluctuations in the volatile energy market. Especially pumped-storage infrastructures in the European Alps play an important role within the European energy grid system. Today, the runoff of rivers in the Alps is often influenced by cascades of hydropower infrastructures where the operational procedures are triggered by energy market demands, water deliveries and flood control aspects rather than by hydro-meteorological variables. An example for such a highly hydropower regulated river is the catchment of the river Inn in the Eastern European Alps, originating in the Engadin (Switzerland). A new hydropower plant is going to be built as transboundary project at the boarder of Switzerland and Austria using the water of the Inn River. For the operation, a runoff forecast to the plant is required. The challenge in this case is that a high proportion of runoff is turbine water from an upstream situated hydropower cascade. The newly developed physically based hydrological forecasting system is mainly capable to cover natural hydrological runoff processes caused by storms and snow melt but can model only a small degree of human impact. These discontinuous parts of the runoff downstream of the pumped storage are described by means of an additional statistical model which has been developed. The main goal of the statistical model is to forecast the turbine water up to five days in advance. The lead time of the data driven model exceeds the lead time of the used energy production forecast. Additionally, the amount of turbine water is linked to the need of electricity production and the electricity price. It has been shown that especially the parameters day-ahead prognosis of the energy production and turbine inflow of the previous week are good predictors and are therefore used as input parameters for the model. As the data is restricted due to technical conditions, so-called Tobit models have been used to

  12. DOE Hydropower Program Annual Report for FY 2002

    Energy Technology Data Exchange (ETDEWEB)

    Garold L. Sommers; R. T. Hunt

    2003-07-01

    The U.S. Department of Energy (DOE) conducts research on advanced hydropower technology through its hydropower program, which is organized under the Office of Wind and Hydropower Technologies within the Office of Energy Efficiency and Renewable Energy. This annual report describes the various projects supported by the hydropower program in FY 2002. The program=s current focus is on improving the environmental performance of hydropower projects by addressing problems such as fish mortality during passage through turbines, alteration of instream habitat, and water quality in tailwaters. A primary goal of this research is to develop new, environmentally friendly technology. DOE-funded projects have produced new conceptual designs for turbine systems, and these are now being tested in pilot-scale laboratory tests and in the field. New design approaches range from totally new turbine runners to modifications of existing designs. Biological design criteria for these new turbines have also been developed in controlled laboratory tests of fish response to physical stresses, such as hydraulic shear and pressure changes. These biocriteria are being combined with computational tools to locate and eliminate areas inside turbine systems that are damaging to fish. Through the combination of laboratory, field, and computational studies, new solutions are being found to environmental problems at hydropower projects. The diverse program activities continue to make unique contributions to clean energy production in the U.S. By working toward technology improvements that can reduce environmental problems, the program is helping to reposition hydropower as an acceptable, renewable, domestic energy choice.

  13. Runner's Knee

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Runner's Knee KidsHealth / For Teens / Runner's Knee What's in this ... told he had runner's knee. What Is Runner's Knee? Runner's knee is the term doctors use for ...

  14. Hydropower Projects

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-04-02

    The Water Power Program helps industry harness this renewable, emissions-free resource to generate environmentally sustainable and cost-effective electricity. Through support for public, private, and nonprofit efforts, the Water Power Program promotes the development, demonstration, and deployment of advanced hydropower devices and pumped storage hydropower applications. These technologies help capture energy stored by diversionary structures, increase the efficiency of hydroelectric generation, and use excess grid energy to replenish storage reserves for use during periods of peak electricity demand. In addition, the Water Power Program works to assess the potential extractable energy from domestic water resources to assist industry and government in planning for our nation’s energy future. From FY 2008 to FY 2014, DOE’s Water Power Program announced awards totaling approximately $62.5 million to 33 projects focused on hydropower. Table 1 provides a brief description of these projects.

  15. Dan jiang kou hydropower station turbine refurbishment

    Science.gov (United States)

    Zhang, R. Y.; Nie, S. Q.; Bazin, D.; Cheng, J. H.

    2012-11-01

    Dan jiangkou hydropower station refurbished project, isan important project of Chinese refurbishment market. Tianjin Alstom Hydro Co., ltd won this contract by right of good performance and design technology,Its design took into account all the constraints linked to the existing frame. It results in a specific and highly advanced shape.The objective of this paper is to introduce the successful turbine hydraulic design, model test and mechanical design of Dan jiangkou project; and also analyze the cavitation phenomena occurred on runner band surface of Unit 4 after putting into commercial operation. These technology and feedback shall be a good reference and experience for other similar projects

  16. DOE Hydropower Program Annual Report for FY 2003

    Energy Technology Data Exchange (ETDEWEB)

    Cada, Glenn F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Carlson, Thomas J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dauble, Dennis D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hunt, Richard T. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab. (INEEL); Sale, Michael J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sommers, Garold L. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab. (INEEL)

    2004-02-01

    This report describes the progress of the R&D conducted in FY 2003 the under four program areas at the time: (1) Advanced Hydropower Technology (Large Turbine Field Testing, Testing of the Alden/NREC pilot scale runner, and Improved Mitigation Practices); (2) Supporting Research and Testing (Biological Design Criteria, Computer and Physical Modeling, Instrumentation and Controls, and Environmental Analysis); (3) Systems Integration and Technology Acceptance (Wind/Hydro Integration Studies and Technical Support and Outreach); and (4) Engineering and Analysis (Innovative Technology Characterization).

  17. Development of biological criteria for the design of advanced hydropower turbines

    Energy Technology Data Exchange (ETDEWEB)

    Cada, Glenn F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Coutant, Charles C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Whitney, Richard R. [Leavenworth, WA (United States)

    1997-03-01

    A review of the literature related to turbine-passage injury mechanisms suggests the following biological criteria should be considered in the design of new turbines: (1) pressure; (2) cavitation; (3) shear and turbulence; and (4) mechanical injury. Based on the study’s review of fish behavior in relation to hydropower facilities, it provides a number of recommendations to guide both turbine design and additional research.

  18. Hydropower: New construction of an advanced plant upon Lech at Augsburg; WasserKraft: Neubau einer innovativen Anlage am Lech in Augsburg

    Energy Technology Data Exchange (ETDEWEB)

    Ferrari, H.; Zaeh, B. [Hydroprojekt Ingenieurgesellschaft mbH, Buero Muenchen (Germany)

    2007-07-15

    The special problem of sediment transportation in the Lech river was a challenge for the new construction of the hydropower plant near-by Augsburg. The requirements to an advanced power plant operation had to be met with ecological facts. The sediment mangement was awarded by the Bavarian Engineer Price. (GL)

  19. DOE Hydropower Program Biennial Report for FY 2005-2006

    Energy Technology Data Exchange (ETDEWEB)

    Sale, Michael J [ORNL; Cada, Glenn F [ORNL; Acker, Thomas L. [Northern Arizona State University and National Renewable Energy Laboratory; Carlson, Thomas [Pacific Northwest National Laboratory (PNNL); Dauble, Dennis D. [Pacific Northwest National Laboratory (PNNL); Hall, Douglas G. [Idaho National Laboratory (INL)

    2006-07-01

    SUMMARY The U.S. Department of Energy (DOE) Hydropower Program is part of the Office of Wind and Hydropower Technologies, Office of Energy Efficiency and Renewable Energy. The Program's mission is to conduct research and development (R&D) that will increase the technical, societal, and environmental benefits of hydropower. The Department's Hydropower Program activities are conducted by its national laboratories: Idaho National Laboratory (INL) [formerly Idaho National Engineering and Environmental Laboratory], Oak Ridge National Laboratory (ORNL), Pacific Northwest National Laboratory (PNNL), and National Renewable Energy Laboratory (NREL), and by a number of industry, university, and federal research facilities. Programmatically, DOE Hydropower Program R&D activities are conducted in two areas: Technology Viability and Technology Application. The Technology Viability area has two components: (1) Advanced Hydropower Technology (Large Turbine Field Testing, Water Use Optimization, and Improved Mitigation Practices) and (2) Supporting Research and Testing (Environmental Performance Testing Methods, Computational and Physical Modeling, Instrumentation and Controls, and Environmental Analysis). The Technology Application area also has two components: (1) Systems Integration and Technology Acceptance (Hydro/Wind Integration, National Hydropower Collaborative, and Integration and Communications) and (2) Supporting Engineering and Analysis (Valuation Methods and Assessments and Characterization of Innovative Technology). This report describes the progress of the R&D conducted in FY 2005-2006 under all four program areas. Major accomplishments include the following: Conducted field testing of a Retrofit Aeration System to increase the dissolved oxygen content of water discharged from the turbines of the Osage Project in Missouri. Contributed to the installation and field testing of an advanced, minimum gap runner turbine at the Wanapum Dam project in Washington

  20. Summary Report of Advanced Hydropower Innovations and Cost Reduction Workshop at Arlington, VA, November 5 & 6, 2015

    Energy Technology Data Exchange (ETDEWEB)

    O' Connor, Patrick [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rugani, Kelsey [Kearns & West, Inc., San Francisco, CA (United States); West, Anna [Kearns & West, Inc., San Francisco, CA (United States)

    2016-03-01

    On behalf of the U.S. Department of Energy (DOE) Wind and Water Power Technology Office (WWPTO), Oak Ridge National Laboratory (ORNL), hosted a day and half long workshop on November 5 and 6, 2015 in the Washington, D.C. metro area to discuss cost reduction opportunities in the development of hydropower projects. The workshop had a further targeted focus on the costs of small, low-head1 facilities at both non-powered dams (NPDs) and along undeveloped stream reaches (also known as New Stream-Reach Development or “NSD”). Workshop participants included a cross-section of seasoned experts, including project owners and developers, engineering and construction experts, conventional and next-generation equipment manufacturers, and others to identify the most promising ways to reduce costs and achieve improvements for hydropower projects.

  1. System dynamics in hydropower plants

    Energy Technology Data Exchange (ETDEWEB)

    Stuksrud, Dag Birger

    1998-12-31

    The main purpose of this thesis on system dynamics in hydropower plants was to establish new models of a hydropower system where the turbine/conduits and the electricity supply and generation are connected together as one unit such that possible interactions between the two power regimes can be studied. In order to describe the system dynamics as well as possible, a previously developed analytic model of high-head Francis turbines is improved. The model includes the acceleration resistance in the turbine runner and the draft tube. Expressions for the loss coefficients in the model are derived in order to obtain a purely analytic model. The necessity of taking the hydraulic inertia into account is shown by means of simulations. Unstable behaviour and a higher transient turbine speed than expected may occur for turbines with steep characteristics or large draft tubes. The turbine model was verified previously with respect to a high-head Francis turbine; the thesis performs an experimental verification on a low-head Francis turbine and compares the measurements with simulations from the improved turbine model. It is found that the dynamic turbine model is, after adjustment, capable of describing low-head machines as well with satisfying results. The thesis applies a method called the ``Limited zero-pole method`` to obtain new rational approximations of the elastic behaviour in the conduits with frictional damping included. These approximations are used to provide an accurate state space formulation of a hydropower plant. Simulations performed with the new computer programs show that hydraulic transients such as water-hammer and mass oscillations are reflected in the electric grid. Unstable governing performance in the electric and hydraulic parts also interact. This emphasizes the need for analysing the whole power system as a unit. 63 refs., 149 figs., 4 tabs.

  2. Hydropower Baseline Cost Modeling

    Energy Technology Data Exchange (ETDEWEB)

    O' Connor, Patrick W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Zhang, Qin Fen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); DeNeale, Scott T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Chalise, Dol Raj [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Centurion, Emma E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-01-01

    Recent resource assessments conducted by the United States Department of Energy have identified significant opportunities for expanding hydropower generation through the addition of power to non-powered dams and on undeveloped stream-reaches. Additional interest exists in the powering of existing water resource infrastructure such as conduits and canals, upgrading and expanding existing hydropower facilities, and the construction new pumped storage hydropower. Understanding the potential future role of these hydropower resources in the nation’s energy system requires an assessment of the environmental and techno-economic issues associated with expanding hydropower generation. To facilitate these assessments, this report seeks to fill the current gaps in publically available hydropower cost-estimating tools that can support the national-scale evaluation of hydropower resources.

  3. 2014 Hydropower Market Report

    Energy Technology Data Exchange (ETDEWEB)

    Rocío Uría-Martínez, Patrick W. O’Connor, Megan M. Johnson

    2015-04-30

    The U.S. hydropower fleet has been providing clean, reliable power for more than a hundred years. However, no systematic documentation exists of the U.S. fleet and the trends influencing it in recent years. This first-ever Hydropower Market Report seeks to fill this gap and provide industry and policy makers with a quantitative baseline on the distribution, capabilities, and status of hydropower in the United States.

  4. Hydropower development in India

    Energy Technology Data Exchange (ETDEWEB)

    Saxena, Praveen [Govt. of India, New Delhi (India). Ministry of New and Renewable Energy], E-mail: psaxena_98@yahoo.com; Kumar, Arun [Indian Institute of Technology Roorkee, Uttarakhand (India). Alternate Hydro Energy Centre], E-mail: aheciitr@gmail.com

    2011-04-15

    India is posed for large deployment of hydropower in present conducive policy and investment environment. Growing energy demand and concern for carbon emission is making hydropower development more favorable. The Government of India is ensuring a good performance of the new SHP stations by linking the incentives to the SHP developers with the performance of the station. (author)

  5. Hydropower annual report 2003

    Energy Technology Data Exchange (ETDEWEB)

    Cada, Glenn F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Carlson, Thomas J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dauble, Dennis D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hunt, Richard T. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Idaho National Engineering Lab. (INEL); Sale, Michael J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sommers, Garold L. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Idaho National Engineering Lab. (INEL)

    2004-02-01

    This report describes hydropower activities supported by the U.S. Department of Energy (DOE) Wind and Hydropower Program during Fiscal Year 2003 (October 1, 2002 to September 30, 2003). Background on the program, FY03 accomplishments, and future plans are presented in the following sections.

  6. Hydropower Modeling Challenges

    Energy Technology Data Exchange (ETDEWEB)

    Stoll, Brady [National Renewable Energy Lab. (NREL), Golden, CO (United States); Andrade, Juan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cohen, Stuart [National Renewable Energy Lab. (NREL), Golden, CO (United States); Brinkman, Greg [National Renewable Energy Lab. (NREL), Golden, CO (United States); Brancucci Martinez-Anido, Carlo [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-04-19

    Hydropower facilities are important assets for the electric power sector and represent a key source of flexibility for electric grids with large amounts of variable generation. As variable renewable generation sources expand, understanding the capabilities and limitations of the flexibility from hydropower resources is important for grid planning. Appropriately modeling these resources, however, is difficult because of the wide variety of constraints these plants face that other generators do not. These constraints can be broadly categorized as environmental, operational, and regulatory. This report highlights several key issues involving incorporating these constraints when modeling hydropower operations in terms of production cost and capacity expansion. Many of these challenges involve a lack of data to adequately represent the constraints or issues of model complexity and run time. We present several potential methods for improving the accuracy of hydropower representation in these models to allow for a better understanding of hydropower's capabilities.

  7. Hydropower Vision: Full Report

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2016-07-01

    Hydropower has provided clean, affordable, reliable, and renewable electricity in the United States for more than a century. Building on hydropower’s historical significance, and to inform the continued technical evolution, energy market value, and environmental performance of the industry, the U.S. Department of Energy’s (DOE’s) Wind and Water Power Technologies Office has led a first-of-its-kind comprehensive analysis focused on a set of potential pathways for the environmentally sustainable expansion of hydropower (hydropower generation and pumped storage) in the United States.

  8. Hydropower research and development

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    This report is a compilation of information on hydropower research and development (R and D) activities of the Federal government and hydropower industry. The report includes descriptions of on-going and planned R and D activities, 1996 funding, and anticipated future funding. Summary information on R and D projects and funding is classified into eight categories: fish passage, behavior, and response; turbine-related; monitoring tool development; hydrology; water quality; dam safety; operations and maintenance; and water resources management. Several issues in hydropower R and D are briefly discussed: duplication; priorities; coordination; technical/peer review; and technology transfer/commercialization. Project information sheets from contributors are included as an appendix.

  9. Nutrition for endurance runners

    OpenAIRE

    Koukol, Michal

    2014-01-01

    Title: Nutrition for endurance runners Objective: The aim of this bachelor thesis is to explain the importance of training diet, particularly a diet for marathon runners in the age of 30 - 40 years. Proposal of diet composition for marathon runners. Methods: I conducted a literature research of czech and foreign sources regarding training diet to get relevant information. I also searched for scientific papers using the internet database EBSCO and Scorpus. Results: Recommended amount of carboh...

  10. Hydropower's Biogenic Carbon Footprint

    National Research Council Canada - National Science Library

    Scherer, Laura; Pfister, Stephan

    2016-01-01

    .... Little is known about the severity of their emissions at the global scale. Here we show that the carbon footprint of hydropower is far higher than previously assumed, with a global average of 173 kg CO2...

  11. Technology Roadmap: Hydropower

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Hydropower could double its contribution by 2050, reaching 2,000 GW of global capacity and over 7,000 TWh. This achievement, driven primarily by the quest of clean electricity, could prevent annual emissions of up to 3 billion tonnes of CO2 from fossil-fuel plants. The bulk of this growth would come from large plants in emerging economies and developing countries. Hydroelectricity’s many advantages include reliability, proven technology, large storage capacity, and very low operating and maintenance costs. Hydropower is highly flexible, a precious asset for electricity network operators, especially given rapid expansion of variable generation from other renewable energy technologies such as wind power and photovoltaics. Many hydropower plants also provide flood control, irrigation, navigation and freshwater supply. The technology roadmap for Hydropower details action needed from policy makers to allow hydroelectric production to double, and addresses necessary conditions, including resolving environmental issues and gaining public acceptance.

  12. Blade Runner forever

    DEFF Research Database (Denmark)

    Dickson, Thomas

    2003-01-01

    Om de påfaldende ligheder mellem scenografien til Ridley Scotts 'Blade Runner'og de faktuelle bymiljøer i nutidens Tokyo.......Om de påfaldende ligheder mellem scenografien til Ridley Scotts 'Blade Runner'og de faktuelle bymiljøer i nutidens Tokyo....

  13. The Kenyan runners.

    Science.gov (United States)

    Larsen, H B; Sheel, A W

    2015-12-01

    Today the Kenyan dominance in middle- and long-distance running is so profound that it has no equivalence to any other sport in the world. Critical physiological factors for performance in running include maximal oxygen consumption (VO2max), fractional VO2max utilization and running economy (energetic cost of running). Kenyan and non-Kenyan elite runners seem to be able to reach very high, but similar maximal oxygen uptake levels just as there is some indication that untrained Kenyans and non-Kenyans have a similar VO2max. In addition, the fractional utilization of VO2max seems to be very high but similar in Kenyan and European runners. Similarly, no differences in the proportion of slow muscle fibers have been observed when comparing Kenyan elite runners with their Caucasian counterparts. In contrast, the oxygen cost of running at a given running velocity has been found to be lower in Kenyan elite runners relative to other elite runners and there is some indication that this is due to differences in body dimensions. Pulmonary system limitations have been observed in Kenyan runners in the form of exercise-induced arterial hypoxemia, expiratory flow limitation, and high levels of respiratory muscle work. It appears that Kenyan runners do not possess a pulmonary system that confers a physiological advantage. Additional studies on truly elite Kenyan runners are necessary to understand the underlying physiology which permits extraordinary running performances. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Injuries among amateur runners ?

    OpenAIRE

    de Araujo, Mariana Korbage; Baeza, Ricardo Maletta; Zalada, Sandro Ricardo Benites; Alves, Pedro Benzam Rodrigues; Mattos, Carlos Augusto de

    2015-01-01

    Objectives To determine the frequency and severity of injuries that affect amateur runners. Methods This study was conducted by means of a questionnaire applied to 204 amateur runners. Individuals who were under the age of 18 years and those who were unpracticed runners were excluded. The data gathered comprised the number, type, site and degree of severity of the injuries and the individuals? age and sex. Results It was observed that male athletes predominated. The mean age was 32.6???9.3 ye...

  15. Stress fractures in runners.

    Science.gov (United States)

    McCormick, Frank; Nwachukwu, Benedict U; Provencher, Matthew T

    2012-04-01

    Stress fractures are a relatively common entity in athletes, in particular, runners. Physicians and health care providers should maintain a high index of suspicion for stress fractures in runners presenting with insidious onset of focal bone tenderness associated with recent changes in training intensity or regimen. It is particularly important to recognize “high-risk” fractures, as these are associated with an increased risk of complication. A patient with confirmed radiographic evidence of a high-risk stress fracture should be evaluated by an orthopedic surgeon. Runners may benefit from orthotics, cushioned sneakers, interval training, and vitamin/calcium supplementation as a means of stress fracture prevention.

  16. Hydropower and its development

    Directory of Open Access Journals (Sweden)

    Janusz Steller

    2013-09-01

    Full Text Available Even if the documented history of hydropower reaches back as far as 5000 years ago, it owes its rapid acceleration in growth to the industrial revolution at the beginning of the nineteenth century. The end of the twentieth century brought about new challenges associated, on the one hand, with a growing demand for ancillary grid services, and on the other with new requirements for mitigating the environmental impact. Hydropower technology expansion had come about in a manner aiming to at least partially exploit the mechanical energy of sea and ocean waters. This study points out to the most important trends in and barriers to hydropower development, with particular focus on the situation in Poland. This author sees the main threats to Polish hydropower development in how it is perceived solely through the prism of the generation of a particular volume of green energy, and a total underestimation of the quality of electricity supply and the numerous non-energy benefits resulting from hydroelectric power plant operation.

  17. DOE Hydropower Program Annual Report for FY 2001

    Energy Technology Data Exchange (ETDEWEB)

    Sale, M. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cada, G. F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Carlson, T. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dauble, D. D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hunt, R. T. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab. (INEEL); Sommers, G. L. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab. (INEEL); Rinehart, B. N. [Consultant; Flynn, J. V. [U.S. Dept. of Energy, Washington, D.C. (United States); Brookshier, P. A. [U.S. Dept. of Energy, Washington, D.C. (United States)

    2002-04-01

    This annual report describes the various projects supported by the hydropower program in FY 2001. The program’s focus for FY 2002 was on improving the environmental performance of hydropower projects by addressing problems such as fish mortality during passage through turbines, alteration of instream habitat, and water quality in tailwaters. A primary goal of this research was to develop new, environmentally friendly technology. DOE-funded projects have produced new conceptual designs for turbine systems, and these were tested in pilot-scale laboratory tests and in the field. New design approaches range from totally new turbine runners (e.g., work by Alden Research Laboratory and Concepts NREC) to modifications to existing designs (e.g., Voith Siemens work on Minimum Gap Runners). Biological criteria have also been developed in controlled laboratory tests of fish response to physical stresses, such as hydraulic shear and pressure changes. These biocriteria were combined with computational design tools to locate and eliminate damaging areas inside turbine systems.

  18. Standard Modular Hydropower Technology Acceleration Workshop: Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Brennan T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); DeNeale, Scott T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Witt, Adam M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mobley, Miles H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Fernandez, Alisha R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-08-01

    In support of the Department of Energy (DOE) funded Standard Modular Hydropower (SMH) Technology Acceleration project, Oak Ridge National Laboratory (ORNL) staff convened with five small hydropower technology entrepreneurs on June 14 and 15, 2017 to discuss gaps, challenges, and opportunities for small modular hydropower development. The workshop was designed to walk through SMH concepts, discuss the SMH research vision, assess how each participant’s technology aligns with SMH concepts and research, and identify future pathways for mutually beneficial collaboration that leverages ORNL expertise and entrepreneurial industry experience. The goal coming out of the workshop is to advance standardized, scalable, modular hydropower technologies and development approaches with sustained and open dialogue among diverse stakeholder groups.

  19. Hydropower's Biogenic Carbon Footprint.

    Science.gov (United States)

    Scherer, Laura; Pfister, Stephan

    2016-01-01

    Global warming is accelerating and the world urgently needs a shift to clean and renewable energy. Hydropower is currently the largest renewable source of electricity, but its contribution to climate change mitigation is not yet fully understood. Hydroelectric reservoirs are a source of biogenic greenhouse gases and in individual cases can reach the same emission rates as thermal power plants. Little is known about the severity of their emissions at the global scale. Here we show that the carbon footprint of hydropower is far higher than previously assumed, with a global average of 173 kg CO2 and 2.95 kg CH4 emitted per MWh of electricity produced. This results in a combined average carbon footprint of 273 kg CO2e/MWh when using the global warming potential over a time horizon of 100 years (GWP100). Nonetheless, this is still below that of fossil energy sources without the use of carbon capture and sequestration technologies. We identified the dams most promising for capturing methane for use as alternative energy source. The spread among the ~1500 hydropower plants analysed in this study is large and highlights the importance of case-by-case examinations.

  20. Hydropower's Biogenic Carbon Footprint.

    Directory of Open Access Journals (Sweden)

    Laura Scherer

    Full Text Available Global warming is accelerating and the world urgently needs a shift to clean and renewable energy. Hydropower is currently the largest renewable source of electricity, but its contribution to climate change mitigation is not yet fully understood. Hydroelectric reservoirs are a source of biogenic greenhouse gases and in individual cases can reach the same emission rates as thermal power plants. Little is known about the severity of their emissions at the global scale. Here we show that the carbon footprint of hydropower is far higher than previously assumed, with a global average of 173 kg CO2 and 2.95 kg CH4 emitted per MWh of electricity produced. This results in a combined average carbon footprint of 273 kg CO2e/MWh when using the global warming potential over a time horizon of 100 years (GWP100. Nonetheless, this is still below that of fossil energy sources without the use of carbon capture and sequestration technologies. We identified the dams most promising for capturing methane for use as alternative energy source. The spread among the ~1500 hydropower plants analysed in this study is large and highlights the importance of case-by-case examinations.

  1. Injuries among amateur runners.

    Science.gov (United States)

    de Araujo, Mariana Korbage; Baeza, Ricardo Maletta; Zalada, Sandro Ricardo Benites; Alves, Pedro Benzam Rodrigues; de Mattos, Carlos Augusto

    2015-01-01

    To determine the frequency and severity of injuries that affect amateur runners. This study was conducted by means of a questionnaire applied to 204 amateur runners. Individuals who were under the age of 18 years and those who were unpracticed runners were excluded. The data gathered comprised the number, type, site and degree of severity of the injuries and the individuals' age and sex. It was observed that male athletes predominated. The mean age was 32.6 ± 9.3 years with a range from 18 to 68 years, and the injuries were classified as mild, keeping the athlete away from practicing running for fewer than eight days. Sprains, blisters and abrasions were the most frequent injuries, located most often on the lower limbs and predominantly on the feet. In practicing running, sprains, blisters and abrasions occur frequently, but are mild injuries. They mostly affect the lower limbs.

  2. Modeling and dynamic behaviour of hydropower plants

    CERN Document Server

    Kishor, Nand

    2017-01-01

    This book presents a systematic approach to mathematical modeling of different configurations of hydropower plants over four sections - modeling and simulation approaches; control of hydropower plants; operation and scheduling of hydropower plants, including pumped storage; and special features of small hydropower plants.

  3. Hydropower's future, the environment, and global electricity systems

    Energy Technology Data Exchange (ETDEWEB)

    Sternberg, R. [Department of Earth and Environmental Studies, Montclair State University, 1 Normal Ave, Montclair, NJ 07043-1624 (United States)

    2010-02-15

    Hydropower is a well established electricity system on the global scene. Global electricity needs by far exceed the amount of electricity that hydrosystems can provide to meet global electricity needs. Much of the world's hydropower remains to be brought into production. Improved technology, better calibrated environmental parameters for large projects have become the norm in the past 15 years. How and why does hydropower retain a prominent role in electricity production? How and why does hydropower find social acceptance in diverse social systems? How does hydropower project planning address issues beyond electricity generation? How does the systems approach to hydropower installations further analysis of comparative energy sources powering electricity systems? Attention to the environmental impact of hydropower facilities forms an integral part of systems analysis. Similarly, the technical, political and economic variables call for balanced analysis to identify the viability status of hydro projects. Economic competition among energy systems requires in context assessments as these shape decision making in planning of hydropower systems. Moreover, technological change has to be given a time frame during which the sector advances in productivity and share in expanding electricity generation. The low production costs per kWh assure hydropower at this juncture, 2009, a very viable future. (author)

  4. World Small Hydropower Development Report

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Heng; Esser, Lara (ICSGP (China)); Masera, Diego (UNIDO, Vienna (Austria))

    2013-07-01

    Currently, small hydropower plants with a capacity of 10 MW, exist in 148 countries or territories worldwide. Four other countries have been identified with resource potential. This report aims to identify the development status and resource potential of small hydro in various countries, territories and regions throughout the world. Working with experts at the ground level to compile and share existing information, experiences and challenges, one comprehensive report was created. Decision-makers, stakeholders and potential investors clearly need this comprehensive information to more effectively promote small hydropower as a renewable and rural energy source for sustainable development and to overcome the existing development barriers. The findings of this report show that small hydropower potential globally is approximated at almost 173 GW. The figure is arrived by totaling data from a wide range of sources with potential compromise of data integrity to varying degrees. For example, research data on economically feasible potential were more readily available in developed countries than those in the least developed or developing countries. More than half of the world's known hydropower potential is located in Asia, around one third can be found in Europe and the Americas. It is possible in the future that more small hydropower potential might be identified both on the African and American continents. The installed small hydropower capacity (up to 10 MW) is estimated to be 75 GW in 2011/2012. The report provides detailed data for each country/region, including recommendations on the national, regional and international level.

  5. DOE Hydropower Program Annual Report for FY 2004

    Energy Technology Data Exchange (ETDEWEB)

    Sommers, Garold L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hunt, Richard T. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cada, Glenn F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sale, Michael J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dauble, Dennis D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carlson, Thomas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ahlgrimm, James [U.S. Dept. of Energy, Washington, D.C. (United States); Acker, Tomas L. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2005-02-01

    This report describes the progress of the R&D conducted in FY 2004 the under four program areas at the time: (1) Advanced Hydropower Technology (Large Turbine Field Testing, Water Use Optimization, and Improved Mitigation Practices); (2) Supporting Research and Testing (Environmental Performance Testing Methods, Computational and Physical Modeling, Instrumentation and Controls, and Environmental Analysis); (3) Systems Integration and Technology Acceptance (Hydro/Wind Integration, National Hydropower Collaborative, and Integration and Communications); and (4) Supporting Engineering and Analysis (Valuation Methods and Assessments and Characterization of Innovative Technology).

  6. DOE Hydropower Program Biennial Report for FY 2005-2006

    Energy Technology Data Exchange (ETDEWEB)

    Sale, Michael J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cada, Glenn F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Acker, Thomas L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Northern Arizona State Univ., Flagstaff, AZ (United States); Carlson, Thomas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dauble, Dennis D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hall, Douglas G. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2006-07-01

    This report describes the progress of the R&D conducted in FY 2005-2006 the under four program areas at the time: (1) Advanced Hydropower Technology (Large Turbine Field Testing, Water Use Optimization, and Improved Mitigation Practices); (2) Supporting Research and Testing (Environmental Performance Testing Methods, Computational and Physical Modeling, Instrumentation and Controls, and Environmental Analysis); (3) Systems Integration and Technology Acceptance (Hydro/Wind Integration, National Hydropower Collaborative, and Integration and Communications); and (4) Supporting Engineering and Analysis (Valuation Methods and Assessments and Characterization of Innovative Technology).

  7. Hidroenergia 2010: International congress on small hydropower. Conference report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This conference, held in 2010 in Lausanne, Switzerland, gathered together the main stakeholders of the small hydropower community to debate about topics affecting the development of the sector, to exchange experience and to present new advances in the technological area. The two-day conference was held in a total of nine sessions, a poster session and a workshop. The first session was dedicated to water management in the Alps and covered new regulations, administrative procedures and finance issues. Contributions included a review of the present situation and the development of common guidelines to meet the challenge of conflicting technical and environmental objectives, the facilitation of small hydropower in Switzerland and the institutional frameworks involved, recent trends in small hydro project financing and the growing roles of venture capital, private equity and changing market dynamics. Finally the prospects for small hydropower in Serbia were discussed. In two parallel sessions the following topics were looked at: The promotion of small hydropower in Switzerland using various sources of water and remuneration for the power produced, small hydro in the Canton of Vaud, Switzerland, the use of karst groundwater for the underground production of power were looked at as well as the analysis of hydraulic facilities for combining pumped storage hydropower systems and wind power in Austria. The final presentation took a look at the new 'La Tzintre' hydropower project. The parallel session dealt with technical innovations and engineering solutions with presentations on the development of small diagonal turbines, the adaptation of propeller turbines to higher specific needs and the problems encountered in doing so. The use of centrifugal pumps as turbines, including a review of technology and applications were also dealt with. Two further parallel sessions looked at EU-funded projects and sustainability issues. The Sustainable Energy Europe project was

  8. Organizing environmental flow frameworks to meet hydropower mitigation needs

    Science.gov (United States)

    McManamay, Ryan A.; Brewer, Shannon K.; Jager, Henriette; Troia, Matthew J.

    2016-01-01

    The global recognition of the importance of natural flow regimes to sustain the ecological integrity of river systems has led to increased societal pressure on the hydropower industry to change plant operations to improve downstream aquatic ecosystems. However, a complete reinstatement of natural flow regimes is often unrealistic when balancing water needs for ecosystems, energy production, and other human uses. Thus, stakeholders must identify a prioritized subset of flow prescriptions that meet ecological objectives in light of realistic constraints. Yet, isolating aspects of flow regimes to restore downstream of hydropower facilities is among the greatest challenges of environmental flow science due, in part, to the sheer volume of available environmental flow tools in conjunction with complex negotiation-based regulatory procedures. Herein, we propose an organizational framework that structures information and existing flow paradigms into a staged process that assists stakeholders in implementing environmental flows for hydropower facilities. The framework identifies areas where regulations fall short of the needed scientific process, and provide suggestions for stakeholders to ameliorate those situations through advanced preparation. We highlight the strengths of existing flow paradigms in their application to hydropower settings and suggest when and where tools are most applicable. Our suggested framework increases the effectiveness and efficiency of the e-flow implementation process by rapidly establishing a knowledge base and decreasing uncertainty so more time can be devoted to filling knowledge gaps. Lastly, the framework provides the structure for a coordinated research agenda to further the science of environmental flows related to hydropower environments.

  9. Organizing Environmental Flow Frameworks to Meet Hydropower Mitigation Needs

    Science.gov (United States)

    McManamay, Ryan A.; Brewer, Shannon K.; Jager, Henriette I.; Troia, Matthew J.

    2016-09-01

    The global recognition of the importance of natural flow regimes to sustain the ecological integrity of river systems has led to increased societal pressure on the hydropower industry to change plant operations to improve downstream aquatic ecosystems. However, a complete reinstatement of natural flow regimes is often unrealistic when balancing water needs for ecosystems, energy production, and other human uses. Thus, stakeholders must identify a prioritized subset of flow prescriptions that meet ecological objectives in light of realistic constraints. Yet, isolating aspects of flow regimes to restore downstream of hydropower facilities is among the greatest challenges of environmental flow science due, in part, to the sheer volume of available environmental flow tools in conjunction with complex negotiation-based regulatory procedures. Herein, we propose an organizational framework that structures information and existing flow paradigms into a staged process that assists stakeholders in implementing environmental flows for hydropower facilities. The framework identifies areas where regulations fall short of the needed scientific process, and provide suggestions for stakeholders to ameliorate those situations through advanced preparation. We highlight the strengths of existing flow paradigms in their application to hydropower settings and suggest when and where tools are most applicable. Our suggested framework increases the effectiveness and efficiency of the e-flow implementation process by rapidly establishing a knowledge base and decreasing uncertainty so more time can be devoted to filling knowledge gaps. Lastly, the framework provides the structure for a coordinated research agenda to further the science of environmental flows related to hydropower environments.

  10. DOE Hydropower Program biennial report 1996-1997 (with an updated annotated bibliography)

    Energy Technology Data Exchange (ETDEWEB)

    Rinehart, B.N.; Francfort, J.E.; Sommers, G.L. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States); Cada, G.F.; Sale, M.J. [Oak Ridge National Lab., TN (United States)

    1997-06-01

    This report, the latest in a series of biennial Hydropower Program reports sponsored by the US Department of Energy, summarizes the research and development and technology transfer activities of fiscal years 1996 and 1997. The report discusses the activities in the six areas of the hydropower program: advanced hydropower turbine systems; environmental research; hydropower research and development; renewable Indian energy resources; resource assessment; and technology transfer. The report also includes an annotated bibliography of reports pertinent to hydropower, written by the staff of the Idaho National Engineering and Environmental Laboratory, Oak Ridge National Laboratory, Federal and state agencies, cities, metropolitan water districts, irrigation companies, and public and independent utilities. Most reports are available from the National Technical Information Service.

  11. The female runner: gender specifics.

    Science.gov (United States)

    Lynch, Stacy L; Hoch, Anne Z

    2010-07-01

    There has been a tremendous increase in the number of female runners of all ages and abilities in the past 35 years. Women who participate in running and sports are generally healthier and have higher self-esteem. However, unique medical and orthopedic issues exist for the female runner. This article reviews the history of women in sports, physiologic and biomechanic differences between genders, the pregnant runner, knee osteoarthritis, an update on the female athlete triad and the relationship between amenorrhea and endothelial dysfunction associated with athletics. Copyright 2010 Elsevier Inc. All rights reserved.

  12. China's rising hydropower demand challenges water sector

    NARCIS (Netherlands)

    Liu, J.; Zhao, D.; Gerbens-Leenes, Winnie; Guan, D.

    2015-01-01

    Demand for hydropower is increasing, yet the water footprints (WFs) of reservoirs and hydropower, and their contributions to water scarcity, are poorly understood. Here, we calculate reservoir WFs (freshwater that evaporates from reservoirs) and hydropower WFs (the WF of hydroelectricity) in China

  13. Small Hydropower in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Hadjerioua, Boualem [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Johnson, Kurt [Telluride Energy, Telluride, CO (United States)

    2015-09-01

    Small hydropower, defined in this report as hydropower with a generating capacity of up to 10 MW typically built using existing dams, pipelines, and canals has substantial opportunity for growth. Existing small hydropower comprises about 75% of the current US hydropower fleet in terms of number of plants. The economic feasibility of developing new small hydropower projects has substantially improved recently, making small hydropower the type of new hydropower development most likely to occur. In 2013, Congress unanimously approved changes to simplify federal permitting requirements for small hydropower, lowering costs and reducing the amount of time required to receive federal approvals. In 2014, Congress funded a new federal incentive payment program for hydropower, currently worth approximately 1.5 cents/kWh. Federal and state grant and loan programs for small hydropower are becoming available. Pending changes in federal climate policy could benefit all renewable energy sources, including small hydropower. Notwithstanding remaining barriers, development of new small hydropower is expected to accelerate in response to recent policy changes.

  14. Environmental Issues Related to Conventional Hydropower

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Zhiqun; Colotelo, Alison HA; Brown, Richard S.; Carlson, Thomas J.

    2016-04-27

    Hydropower is the largest renewable electrical energy source in the world and has a total global capacity of approximately 1,010 GW from 150 countries. Although hydropower has many environmental advantages, hydropower dams have potential adverse ecological impacts such as fish passage, water quality, and habitat alterations.

  15. EPRI-DOE Conference on Environmentally-Enhanced Hydropower Turbines: Technical Papers

    Energy Technology Data Exchange (ETDEWEB)

    Hogan, T. [Alden Research Laboratory, Inc., Holden, MA (United States)

    2011-12-01

    The EPRI-DOE Conference on Environmentally-Enhanced Hydropower Turbines was a component of a larger project. The goal of the overall project was to conduct the final developmental engineering required to advance the commercialization of the Alden turbine. As part of this effort, the conference provided a venue to disseminate information on the status of the Alden turbine technology as well as the status of other advanced turbines and research on environmentally-friendly hydropower turbines. The conference was also a product of a federal Memorandum of Understanding among DOE, USBR, and USACE to share technical information on hydropower. The conference was held in Washington, DC on May 19 and 20, 2011 and welcomed over 100 attendees. The Conference Organizing Committee included the federal agencies with a vested interest in hydropower in the U.S. The Committee collaboratively assembled this conference, including topics from each facet of the environmentally-friendly conventional hydropower research community. The conference was successful in illustrating the readiness of environmentally-enhanced hydropower technologies. Furthermore, the topics presented illustrated the need for additional deployment and field testing of these technologies in an effort to promote the growth of environmentally sustainable hydropower in the U.S. and around the world.

  16. Hydropower and Sustainable Development: A Journey

    Energy Technology Data Exchange (ETDEWEB)

    Schumann, Kristin; Saili, Lau; Taylor, Richard; Abdel-Malek, Refaat

    2010-09-15

    Hydropower produces 16% of our electricity; it is one of the world's major renewable energy resources. It is playing an important role in enabling communities around the world to meet their power and water needs. The pace of hydropower growth has been rapid but sometimes with little guidance to ensure development is based on sustainability principles. Some of the most promising initiatives to fill the void, such as the Hydropower Sustainability Assessment Protocol, have been driven by the hydropower sector itself. Efforts focus on carrying forward this momentum to obtain a tool for hydropower sustainability agreed across sectors and stakeholders.

  17. Hydropower Baseline Cost Modeling, Version 2

    Energy Technology Data Exchange (ETDEWEB)

    O' Connor, Patrick W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-01

    Recent resource assessments conducted by the United States Department of Energy have identified significant opportunities for expanding hydropower generation through the addition of power to non-powered dams and on undeveloped stream-reaches. Additional interest exists in the powering of existing water resource infrastructure such as conduits and canals, upgrading and expanding existing hydropower facilities, and the construction new pumped storage hydropower. Understanding the potential future role of these hydropower resources in the nation’s energy system requires an assessment of the environmental and techno-economic issues associated with expanding hydropower generation. To facilitate these assessments, this report seeks to fill the current gaps in publically available hydropower cost estimating tools that can support the national-scale evaluation of hydropower resources.

  18. Modelling and controlling hydropower plants

    CERN Document Server

    Munoz-Hernandez, German Ardul; Jones, Dewi Ieuan

    2013-01-01

    Hydroelectric power stations are a major source of electricity around the world; understanding their dynamics is crucial to achieving good performance.  Modelling and Controlling Hydropower Plants discusses practical and well-documented cases of modelling and controlling hydropower station modelling and control, focussing on a pumped storage scheme based in Dinorwig, North Wales.  Single-input-single-output and multiple-input-multiple-output models, which cover the linear and nonlinear characteristics of pump-storage hydroelectric power stations, are reviewed. The most important dynamic features are discussed, and the verification of these models by hardware in the loop simulation is described. To show how the performance of a pump-storage hydroelectric power station can be improved, classical and modern controllers are applied to simulated models of the Dinorwig power plant. These include PID, fuzzy approximation, feed-forward and model-based predictive control with linear and hybrid prediction models. Mod...

  19. Private equity, public affair: Hydropower financing in the Mekong Basin

    NARCIS (Netherlands)

    Merme, V.; Ahlers, R.; Gupta, J.

    2014-01-01

    Large-scale hydropower development is increasingly popular. Although international finance is a significant driver of hydropower market expansion, financial data is relatively obscure and literature remains scarce. This article tracks the financial process in hydropower development in the Mekong

  20. Surge Tank Atlas for Hydropower Plants

    OpenAIRE

    Sandvåg, Simon Utseth

    2016-01-01

    The objective of this master's thesis is to describe the existing surge tank solutions and additional improvements, and to simulate the hydraulic behavior of the surge tanks and how it affects the hydropower plant. The high head hydropower plant Torpa and the low head hydropower plant Åna-Sira are used for the case study, thus the surge tanks can be simulated under different hydraulic conditions. Turbine pressures and mass oscillations after a complete turbine shutdown, and turbine regulation...

  1. Pumped Storage and Potential Hydropower from Conduits

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2015-02-25

    Th is Congressional Report, Pumped Storage Hydropower and Potential Hydropower from Conduits, addresses the technical flexibility that existing pumped storage facilities can provide to support intermittent renewable energy generation. This study considered potential upgrades or retrofit of these facilities, the technical potential of existing and new pumped storage facilities to provide grid reliability benefits, and the range of conduit hydropower opportunities available in the United States.

  2. The Virtual Runner Learning Game

    Directory of Open Access Journals (Sweden)

    Reinhold Behringer

    2014-02-01

    Full Text Available A learning game has been developed which allows learners to study and learn about the significance of three important variables in human physiology (lactate, glycogen, and hydration and their influence on sports performance during running. The player can control the speed of the runner, and as a consequence the resulting physiological processes are simulated in real-time. The performance degradation of the runner due to these processes requires that different strategies for pacing the running speed are applied by the player, depending on the total length of the run. The game has been positively evaluated in a real learning context of academic physiology teaching.

  3. Anthropometric and functional characteristics of Colombian elite long-distance runners

    OpenAIRE

    Ramírez-Vélez, Robinson; Argothy-Bucheli, Rodrigo; Sánchez-Puccini, María Beatriz; Meneses-Echávez, José Francisco; López-Albán, Carlos Alejandro

    2015-01-01

    Objective: To evaluate the anthropometric and physical performance characteristics of elite long-distance runners. Methods: A cross-sectional study in 19 male competitive long-distance runners of national level (age 28.2 ± 6.9 years). A total of 24 anthropometric variables were measured according to the International Society for the Advancement of Kinanthropometry (ISAK) statements. The Heath-Carter method and the formula proposed by Siri, Matiegka, Jackson and Pollock were used to calcula...

  4. Siphon-based turbine - Demonstration project: hydropower plant at a paper factory in Perlen, Switzerland; Demonstrationsprojekt Saugheber - Turbinen. Wasserturbinenanlage Papierfabrik Perlen (WTA-PF)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) describes the demonstration project that concerned the re-activation and refurbishing of a very low-head hydropower installation. The functional principles of the siphon-turbine used are explained and the potential for its use at many low-head sites examined. The authors are of the opinion that innovative technology and simple mechanical concepts could be used to reactivate out-of-use hydropower plant or be used to refurbish existing plant to provide increased efficiency and reliability. Various other points that are to be considered when planning the refurbishment of a hydropower plant such as retaining mechanical and hydraulic symmetry in the plant are listed and concepts for reducing operating costs are discussed. Figures on the three runner-regulated turbines installed in Perlen are quoted.

  5. Heel Pain in Recreational Runners.

    Science.gov (United States)

    Bazzoli, Allan S.; Pollina, Frank S.

    1989-01-01

    Provides physicians with the signs, symptoms, and management of heel/sole pain in recreational runners (usually due to plantar fasciitis, Achilles tendinitis, and calcaneal stress fractures). Remedies involve palliative treatment of symptoms, correction of underlying biomechanical problems, and flexibility exercises. (SM)

  6. The water footprint of electricity from hydropower

    NARCIS (Netherlands)

    Mekonnen, Mesfin; Hoekstra, Arjen Ysbert

    Hydropower accounts for about 16% of the world’s electricity supply. Although dams often have big environmental and social impacts, proponents of hydropower regard it as a comparatively clean, low-cost and renewable form of energy. It has been debated whether hydroelectric generation is merely an

  7. U.S. Hydropower Resource Assessment - California

    Energy Technology Data Exchange (ETDEWEB)

    A. M. Conner; B. N. Rinehart; J. E. Francfort

    1998-10-01

    The U.S. Department of Energy is developing an estimate of the underdeveloped hydropower potential in the United States. For this purpose, the Idaho National Engineering and Environmental Laboratory developed a computer model called Hydropower Evaluation Software (HES). HES measures the undeveloped hydropower resources available in the United States, using uniform criteria for measurement. The software was developed and tested using hydropower information and data provided by the Southwestern Power Administration. It is a menu-driven program that allows the personal computer user to assign environmental attributes to potential hydropower sites, calculate development suitability factors for each site based on the environmental attributes present, and generate reports based on these suitability factors. This report describes the resource assessment results for the State of California.

  8. US hydropower resource assessment for Montana

    Energy Technology Data Exchange (ETDEWEB)

    Francfort, J.E.

    1993-12-01

    The Department of Energy is developing an estimate of the hydropower development potential in this country. The Hydropower Evaluation Software (HES) is a computer model that was developed by the Idaho National Engineering Laboratory for this purpose. The HES measures the potential hydropower resources available in the United States, using uniform criteria for measurement. The software was developed and tested using hydropower information and data provided by the Southwestern Power Administration. It is a dBASE menu-driven software application that allows the personal computer user to assign environmental attributes to potential hydropower sites, calculate development suitability factors for each site based on the environmental attributes present, and generate reports based on these suitability factors. This report details the resource assessment results for the state of Montana.

  9. US hydropower resource assessment for New Hampshire

    Energy Technology Data Exchange (ETDEWEB)

    Francfort, J.E.

    1995-07-01

    The Department of Energy is developing an estimate of the undeveloped hydropower potential in this country. The Hydropower Evaluation Software is a computer model that was developed by the Idaho National Engineering Laboratory for this purpose. The software measures the undeveloped hydropower resources available in the United States, using uniform criteria for measurement. The software was developed and tested using hydropower information and data provided by the Southwestern Power Administration. It is a menu-driven software program that allows the personal computer user to assign environmental attributes to potential hydropower sites, calculate development suitability factors for each site based on the environmental attributes present, and generate reports based on these suitability factors. This report details the resource assessment results for the State of New Hampshire.

  10. US hydropower resource assessment for New Jersey

    Energy Technology Data Exchange (ETDEWEB)

    Connor, A.M.; Francfort, J.E.

    1996-03-01

    The Department of Energy is developing an estimate of the undeveloped hydropower potential in this country. The Hydropower Evaluation Software is a computer model that was developed by the Idaho National Engineering Laboratory for this purpose. The software measures the undeveloped hydropower resources available in the United States, using uniform criteria for measurement. The software was developed and tested using hydropower information and data provided by the Southwestern Power Administration. It is a menu-driven software program that allows the personal computer user to assign environmental attributes to potential hydropower sites, calculate development suitability factors for each site based on the environmental attributes present, and generate reports based on these suitability factors. This report details the resource assessment results for the State of New Jersey.

  11. US hydropower resource assessment for Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Francfort, J.E.

    1994-05-01

    The US Department of Energy is developing an estimate of the hydropower development potential in this country. Hydropower Evaluation Software (HES) is a computer model that was developed by the Idaho National Engineering Laboratory for this purpose. HES measures the potential hydropower resources available in the United States, using uniform criteria for measurement. The software was developed and tested using hydropower information and data provided by the Southwestern Power Administration. It is a dBASE, menu-driven software application. HES allows the personal computer user to assign environmental attributes to potential hydropower sites, calculate development suitability factors for each site based on the environmental attributes present, and generate reports based on these suitability factors. This report details the resource assessment results for the State of Colorado.

  12. US hydropower resource assessment for Kansas

    Energy Technology Data Exchange (ETDEWEB)

    Francfort, J.E.

    1993-12-01

    The Department of Energy is developing an estimate of the hydropower development potential in this country. The Hydropower Evaluation Software (HES) is a computer model that was developed by the Idaho National Engineering Laboratory for this purpose. The HES measures the potential hydropower resources available in the United States, using uniform criteria for measurement. The software was developed and tested using hydropower information and data provided by the Southwestern Power Administration. It is a dBASE menu-driven software application that allows the personal computer user to assign environmental attributes to potential hydropower sites, calculate development suitability factors for each site based on the environmental attributes present, and generate reports based on these suitability factors. This report details the resource assessment results for the state of Kansas.

  13. SEE HYDROPOWER Project, targeted to improve water resource management for a growing renewable energy production

    Science.gov (United States)

    Peviani, Maximo; Alterach, Julio; Danelli, Andrea

    2010-05-01

    problem, and there is a strong need of a more accurate planning and management optimization of the resources. The partnership includes a well balance mixing of public administrations, agencies ruling hydropower development, water bodies conservation and scientific institutions having the most advanced technology applied to water management and hydropower generation. Furthermore, a permanent "consultant panel" integrated by target groups representatives from different European countries are involved in key decisions and meetings, that guaranty a concrete regional scale participation. The present work reports the overall strategy of the project and the description of the main informatic tools that are under development and implementation in five pilot regions, located in Italy, Austria, Romania, Slovenia and Greece. Keywords: WFD Directive, RES-e Directive, water multi-purpose uses, renewable energy, small hydropower production, environmental balance, minimum environmental flow, flood protection

  14. Multicriterion analysis of hydropower operation

    Energy Technology Data Exchange (ETDEWEB)

    Duckstein, L.; Hobbs, B.F. (Case Western Reserve Univ., Cleveland, OH (US)); Tecle, A. (School of Forestry, Northern Arizona Univ., Flagstaff, AZ (US)); Nachnebel, H.P. (Institute of Water Resources, Univ. fur Bodenkulur, Gregormendelstr. 33, 1180 Wien (AT))

    1989-12-01

    Two examples are presented to show how multicriterion decision-making (MCDM) techniques can help hydropower engineers mitigate the environmental and social effects of hydropower development and operation. A brief introduction and overview of MCDM is presented, consisting of an 11-step process that starts with problem definition and ends with implementation. A typology of MCDM is provided, dividing the techniques into three groups: outranking, distance-based, and value- or utility-based typed. The operation of the Upper Isar River project in Bavaria is analyzed by means of a value technique and an out-ranking technique called multicriterion Q-analysis. Fourteen criteria are considered in that study, including power production, habitat quality for four groups of species, aesthetics, several recreation indices, minimum flows, and phosphorus loadings. The case study of the Erlauf River Division in Austria is evaluated using a distance-based technique, called composite programming, combined with Monte Carlo simulation. An outcome of that study is that the facility's owners have increased the minimum instream flow in order to protect ecological values.

  15. CERN runners scale new heights

    CERN Document Server

    2001-01-01

    On a bright and sunny 1 December last, a team from CERN lifted the honours for the company team event of Switzerland's most popular running race. The occasion was the 24th 'Course de l'Escalade'. Photo : Part of the field in the men's over-50 categories. Gordon Lee (IT) is in the white top, just behind the runner in yellow in the centre of the photo.

  16. Excellent results for CERN runners

    CERN Multimedia

    Hervé Cornet, CERN Running club

    2015-01-01

    As in previous years, thirty or so runners from CERN took part in the Tour du Canton de Genève (more information here, in French only).   The men’s team that won the corporate challenge prize in the Tour du Canton de Genève: (standing, left to right) Patrick Villeton, Phil Hebda, Mika Vesterinen, Steffen Doebert; (sitting, left to right) Guillaume Michet and Camille Ruiz-Llamas. The Laboratory was represented in the corporate challenge by five teams, one of which came first in the men’s category. CERN’s other teams also put in good performances, with one finishing fourth in the men's category and another seventh in the mixed category. Runners from CERN did well in the individual classifications too. All the results can be found here. The Maxi Race team: (left to right) Sebastien Ponce, Alain Cauphy, Klaus Hanke and Christophe Biot. Elsewhere, four CERN runners competed in the finals of the Annecy Maxi Race (site in French only...

  17. Elite Distance Runners and Breastfeeding.

    Science.gov (United States)

    Giles, Audrey R; Phillipps, Breanna; Darroch, Francine E; McGettigan-Dumas, Roisin

    2016-11-01

    Elite female distance runners lack guidelines regarding breastfeeding while training at a high intensity. The purpose of this research was to understand how elite female distance runners manage breastfeeding. Semistructured interviews were conducted with 14 women who had had at least one pregnancy within the past 5 years and had achieved a minimum of the USA Track and Field 2012 Olympic Trials "B" entry standard for running for the marathon or equivalent performance for 1,500 m or longer. Using thematic analysis, we identified the following themes: breastfeeding as a barrier to training and competition, limited access to relevant breastfeeding information, and concerns for the baby's health. Our findings show that despite the considerable barriers with which these women contend, they breastfed at higher rates and for longer duration than members of the general public. Based on our findings, we argue that elite female distance runners' experiences of breastfeeding would be enhanced if more research were conducted on breastfeeding practices while training and competing at an elite level.

  18. CERN runners scale new heights

    CERN Document Server

    2002-01-01

    Part of the field in the men's over-50 categories. Gordon Lee (IT) is in the white top, just behind the runner in yellow in the centre of the photo. On a bright and sunny 1 December last, a team from CERN lifted the honours for the company team event of Switzerland's most popular running race. The occasion was the 24th 'Course de l'Escalade'. The Escalade races wind through the narrow streets of Geneva's Old Town, lined with friends and well-wishers for the event. Since they began in 1978, they have become so popular that the Escalade now ranks among the largest popular running events in Europe. Some 19000 people aged from 5 to 85 donned running shoes to brave the crowds last December. Clearly, not all could run at once, so races by category started at 11am and continued until after 7pm. Distances ranged from about 2 km for the youngest children to 7.5 km for the men's categories. 100 or so runners, men and women, from the top international elite were invited for the race. CERN runners had a double reason t...

  19. Hydropower Manufacturing and Supply Chain Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cotrell, Jason R [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-01-02

    Hydropower Manufacturing and Supply Chain Analysis presentation from the WPTO FY14-FY16 Peer Review. The project objective is to provide data and insights to inform investment strategies, policy, and other decisions to promote economic growth and manufacturing.

  20. Hydropower scene: boost for Dominican power supply

    Energy Technology Data Exchange (ETDEWEB)

    1988-12-01

    When it is completed in 1991, the 150 MW Jiguey-Aguacate multi-purpose hydropower scheme will be the largest hydro project in the Dominican Republic. Construction of the scheme was recommended as a result of various studies carried out by the Instituto Nacional de Recursos Hidraulicos (INDHRI), which examined the hydropower potential of the Niazo river. Work is now in progress on site, with commissioning of the first unit expected in 1990.

  1. Present situation and future prospect of hydropower in China

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Hailun; Yan, Zheng [Department of Electrical Engineering, Shanghai Jiaotong University, Shanghai 200240 (China)

    2009-08-15

    Hydropower is a clean and renewable energy source. Considering the economic, technical and environmental benefits of hydropower, most countries give priority to its development. China has the richest hydro resources on the planet with a total theoretical hydropower potential of 694 GW. Developing hydropower is of great importance to alleviate the energy crisis and environmental pollution resulting from the rapid economic growth of China in the 21st century. This paper provides a survey of hydropower development in China. Over the last five decades, China's hydropower has developed quickly. The installed capacity of hydropower is 145.26 GW presently. Some large hydropower plants have been in operation and many are still under construction, including the Three Gorges Project (TGP) and pumped-storage power stations. Small hydropower development accelerates rural electrification of this country. (author)

  2. Hydropower Resource Assessment of Brazilian Streams

    Energy Technology Data Exchange (ETDEWEB)

    Douglas G. Hall

    2011-09-01

    The Idaho National Laboratory (INL) in collaboration with the U.S. Geological Survey (USGS) with the assistance of the Empresa de Pesquisa Energetica (EPE) and the Agencia Nacional de Energia Electrica (ANEEL) has performed a comprehensive assessment of the hydropower potential of all Brazilian natural streams. The methodology by which the assessment was performed is described. The results of the assessment are presented including an estimate of the hydropower potential for all of Brazil, and the spatial distribution of hydropower potential thus providing results on a state by state basis. The assessment results have been incorporated into a geographic information system (GIS) application for the Internet called the Virtual Hydropower Prospector do Brasil. VHP do Brasil displays potential hydropower sites on a map of Brazil in the context of topography and hydrography, existing power and transportation infrastructure, populated places and political boundaries, and land use. The features of the application, which includes tools for finding and selecting potential hydropower sites and other features and displaying their attributes, is fully described.

  3. Hypernatremia and intravenous fluid resuscitation in collapsed ultramarathon runners.

    Science.gov (United States)

    Hew-Butler, Tamara; Boulter, Jeremy; Mbchb, John Godlonton; Phd, Ross Tucker; Mbchb, Timothy Noakes

    2008-05-01

    To determine if a return to normonatremia is required for symptomatology to resolve in collapsed hypernatremic runners and if intravenous (IV) administration of an isotonic solution would adversely affect serum sodium concentration ([Na+]) in collapsed normonatremic runners. Observational study. 2006 Comrades Marathon. 103 collapsed runners. Final serum [Na] upon discharge. 58% of all collapsed runners were hypernatremic. Hypernatremic runners reported significantly more vomiting than normonatremic runners (79 versus 34%; P 145 mmol/L). A return to normonatremia was not required for hypernatremic runners to "recover" and be discharged from the medical tent. Vomiting either aggravated and/or facilitated the development of hypernatremia. IV administration of 1 L of either (1) a hypotonic solution to hypernatremic runners or (2) an isotonic solution to both normonatremic and hypernatremic runners did not produce any adverse biochemical or cardiovascular changes and can therefore be considered a safe and effective treatment for collapsed runners if used in this context.

  4. Injury risk factors for runners

    Directory of Open Access Journals (Sweden)

    Francisco Rodal Abal

    2013-01-01

    Full Text Available The purpose of this study was to determine those risk factors that may cause running injuries in general, and particularly damage to the muscle mass, and the tendon. Twenty six male and female Galician runners were evaluated about their lower limb flexibility and length, knee Q angle, explosive power and training features such as kilometers and sessions per week, level of competition, shoes, surface, injuries last year, use of insoles, athletic specially, age, weight and height. During next 12 weeks runners continued training as they had been doing regularly and we recorded all injuries that appeared in this period. After that and from the liner regression we obtained different models that explained the variability of general injuries, tendon injuries and damages to the muscle mass. We also find positive correlations between previous injuries and training volume, and these with the dependent variable «injuries in 12 weeks». In regard to tendinopathy and muscle mass injuries, we observed that the synthetic material present in the track is a risk factor for these muscle injuries. Meanwhile, the increasing age and the Q angle, increments the occurrence of tendon injuries.

  5. Quantifying the Value of Hydropower in the Electric Grid: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Key, T. [Electric Power Research Inst. (EPRI), Knovville, TN (United States); Rogers, L. [Electric Power Research Inst. (EPRI), Knovville, TN (United States); Brooks, D. [Electric Power Research Inst. (EPRI), Knovville, TN (United States); Tuohy, A. [Electric Power Research Inst. (EPRI), Knovville, TN (United States)

    2012-12-31

    of energy, capacity, and ancillary services. Many potential improvements to existing hydropower plants were found to be cost-effective. Pumped storage is the most likely form of large new hydro asset expansions in the U.S. however, justifying investments in new pumped storage plants remains very challenging with current electricity market economics. Even over a wide range of possible energy futures, up to 2020, no energy future was found to bring quantifiable revenues sufficient to cover estimated costs of plant construction. Value streams not quantified in this study may provide a different cost-benefit balance and an economic tipping point for hydro. Future studies are essential in the quest to quantify the full potential value. Additional research should consider the value of services provided by advanced storage hydropower and pumped storage at smaller time steps for integration of variable renewable resources, and should include all possible value streams such as capacity value and portfolio benefits i.e.; reducing cycling on traditional generation.

  6. Distance Runners as Models of Optimal Health.

    Science.gov (United States)

    Elrick, H

    1981-01-01

    In brief: Distance runners are suggested as a new model for optimal health standards because normal values are now derived from the American public, which is notorious for its obesity, low level of physical fitness, bad eating habits, use of cigarettes and drugs, and high incidence of cardiovascular and other degenerative diseases. As a group, the 50 distance runners studied showed lower than normal body weight, body fat, resting heart rate, serum cholesterol and triglycerides; higher HDL cholesterol; and lower cholesterol/HDL cholesterol ratios. However, the runners who ate the average American diet sometimes had normal values.

  7. Land Systems Impacts of Hydropower Development

    Science.gov (United States)

    Wu, G. C.; Torn, M. S.

    2016-12-01

    Hydropower is often seen as the low-cost, low-carbon, and high-return technology for meeting rising electricity demand and fueling economic growth. Despite the magnitude and pace of hydropower expansion in many developing countries, the potential land use and land cover change (LULCC), particularly indirect LULCC, resulting from hydropower development is poorly understood. Hydropower-driven LULCC can have multiple impacts ranging from global and local climate modification (e.g., increased extreme precipitation events or increased greenhouse gas emissions), ecosystem degradation and fragmentation, to feedbacks on hydropower generation (e.g., increased sedimentation of the reservoir). As a result, a better understanding of both direct and indirect LULCC impacts can inform a more integrated and low-impact model for energy planning in countries with transitioning or growing energy portfolios. This study uses multi-scale remote sensing imagery (Landsat, MODIS, fine-resolution commercial imagery) to estimate LULCC from past hydropower projects intended primarily for electricity generation in 12 countries in Africa, South and Central America, South Asia, and Southeast Asia. It is important to examine multiple locations to determine how socio-political and environmental context determines the magnitude of LULCC. Previous studies have called for the need to scale-up local case studies to examine "cumulative impacts" of multiple development activities within a watershed. We use a pre-test/post-test quasi-experimental design using a time series of classified images and vegetation indices before and after hydropower plant construction as the response variable in an interrupted time series regression analysis. This statistical technique measures the "treatment" effect of hydropower development on indirect LULCC. Preliminary results show land use change and landscape fragmentation following hydropower development, primarily agricultural and urban in nature. These results suggest

  8. Electrolysis Production of Hydrogen from Wind and Hydropower Workshop Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    None

    2003-09-01

    This document summarizes the opportunities and challenges for low-cost renewable hydrogen production from wind and hydropower. The Workshop on Electrolysis Production of Hydrogen from Wind and Hydropower was held September 9-10, 2003.

  9. World Small Hydropower Development Report 2013 - Southern Africa

    CSIR Research Space (South Africa)

    Jonker Klunne, W

    2013-01-01

    Full Text Available The Southern African region comprises five countries, of which Lesotho, Namibia, Swaziland and South Africa use small hydropower, with Namibia currently having a very limited use of this technology. Botswana does not possess any hydropower plants...

  10. Harnessing Hydropower: The Earth's Natural Resource

    Energy Technology Data Exchange (ETDEWEB)

    None

    2011-04-01

    This document is a layman's overview of hydroelectric power. It includes information on: History of Hydropower; Nature’s Water Cycle; Hydropower Plants; Turbines and Generators; Transmission Systems; power dispatching centers; and Substations. It goes on to discuss The Power Grid, Hydropower in the 21st Century; Energy and the Environment; and how hydropower is useful for Meeting Peak Demands. It briefly addresses how Western Area Power Administration is Responding to Environmental Concerns.

  11. Hydropower potential of the lower Vistula

    Directory of Open Access Journals (Sweden)

    Michał Szydłowski

    2015-03-01

    Full Text Available This paper presents an estimate analysis of the hydropower potential of the lower Vistula River from Warsaw to Gdańsk Bay. The calculations were made for a hydraulic model of the lower Vistula which takes into account potential development of barrages in a cascade system. Results obtained from the model simulations and from hydrological calculations were used to estimate the power of hydropower plants and the average annual energy output from the entire cascade system. The results of calculations indicate significant energy benefits resulting from the development of a cascade of hydropower plants in the lower Vistula. This study does not discuss the cascade project’s economic viability or other aspects of its development (inland waterways, flood control, etc..

  12. Development potential for hydropower; Ausbaupotential der Wasserkraft

    Energy Technology Data Exchange (ETDEWEB)

    Laufer, F.; Groetzinger, S.; Peter, M.; Schmutz, A.

    2004-11-15

    This comprehensive report for the Swiss Federal Office of Energy (SFOE) takes a look at the potential for the development of hydropower in Switzerland. The report updates the energy perspectives made ten years earlier. An overview of Swiss electricity production and consumption is presented and the proportion provided by hydropower is noted. Figures on installed capacity and import/export quantities are presented and discussed. Technological developments and the economical frameworks involved are discussed, as are regulatory measures that can be taken. Theoretical and technically realisable potentials for increased use of hydropower are discussed. The methods used to do this are examined. Strategies and measures to be taken are listed and discussed. An appendix includes data sheets on power plant modelling, including examples

  13. Arming and firing system for DISTANT RUNNER

    Energy Technology Data Exchange (ETDEWEB)

    Skenandore, L.H.; Johnson, J.P.

    1982-03-01

    Sandia A and F systems Division 1132 provided arming and firing support for the DISTANT RUNNER Test Program at White Sands Missile Range. This report describes the field support and the firing system that was used.

  14. Echocardiography to measure fitness of elite runners.

    Science.gov (United States)

    Legaz Arrese, Alejandro; Serrano Ostáriz, Enrique; González Carretero, Mariano; Lacambra Blasco, Isaac

    2005-05-01

    We evaluated the echocardiograms of 134 male and 54 female elite runners who competed over different distances to observe cardiac enlargement and differences among athletes engaged in different types of training, and to relate the echographic dimension with running performance. In male runners, left ventricular (LV) internal diameter at end diastole (LVIDd), LV mass, and left atrial diameter were increased by the length of distance ( P hypertrophy and that it is necessary to establish a new upper limit of abnormal cavity dilatation as indexed LVIDd. The normal systolic function and the relationship between LVIDd and performance indicate that LV enlargement in elite runners is a physiologic adaptation and that echocardiographic assessment can be used to determine the fitness of runners.

  15. Perceived exertion influences pacing among ultramarathon runners ...

    African Journals Online (AJOL)

    ±7.3, p=0.0003; baseline v. post race). A linear increase in RPE was ... of discrepancy between runners' predicted and actual performance. This has implications for designing appropriate goals and pacing strategies for ultraendurance athletes.

  16. Bone health in elite Kenyan runners.

    Science.gov (United States)

    Tam, Nicholas; Santos-Concejero, Jordan; Tucker, Ross; Lamberts, Robert P; Micklesfield, Lisa K

    2018-02-01

    Impact loading in athletes participating in various sports has been positively associated with increased bone mineral density (BMD), but this has not been investigated in elite Kenyan runners. Body composition and site-specific BMD measures quantified with dual x-ray absorptiometry were measured in 15 elite male Kenyan runners and 23 apparently healthy South African males of different ethnicities. Training load and biomechanical variables associated with impact loading, such as joint stiffness, were determined in the elite Kenyan runners. Greater proximal femur (PF) BMD (g · cm -2 ) was higher (P = 0.001, ES = 1.24) in the elite Kenyan runners compared with the controls. Six of the 15 (40%) Kenyan runners exhibited lumbar spine (LS) Z-Scores below -2.0 SD, whereas this was not found in the apparently healthy controls. PFBMD was associated with training load (r = 0.560, P = 0.003) and ankle (r = 0.710, P = 0.004) and knee (r = 0.546, P = 0.043) joint stiffness. Elite Kenyan runners exhibit greater PFBMD than healthy controls, which is associated with higher training load and higher joint stiffness. Our results reaffirm the benefits of impact loading on BMD at a weight-bearing site, while a high prevalence of low LSBMD in the elite Kenyan runners is hypothesised to be the result of a mismatch between energy intake and high training load. Future research investigating energy availability in Kenyan runners and the possible association with musculoskeletal injury should be investigated.

  17. The sustainability of hydropower projects in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    de Methodio Maranhao Neto, Gil; Yana, Laurent

    2010-09-15

    The construction of hydropower plants unquestionably impacts the environment and communities. But countries such as Brazil have been able to build up a sophisticated socio-environmental legislation and institutions as well as a democratic and participative licensing process to protect the nature and the population affected. In some cases, plants greatly contribute towards the creation of local welfare to the population as well as good environmental practices. As a good example of best practices on socio-environmental standards, we will analyze Jirau Hydropower Project, currently under construction on the Madeira River, north of Brazil.

  18. Minimizing water consumption when producing hydropower

    Science.gov (United States)

    Leon, A. S.

    2015-12-01

    In 2007, hydropower accounted for only 16% of the world electricity production, with other renewable sources totaling 3%. Thus, it is not surprising that when alternatives are evaluated for new energy developments, there is strong impulse for fossil fuel or nuclear energy as opposed to renewable sources. However, as hydropower schemes are often part of a multipurpose water resources development project, they can often help to finance other components of the project. In addition, hydropower systems and their associated dams and reservoirs provide human well-being benefits, such as flood control and irrigation, and societal benefits such as increased recreational activities and improved navigation. Furthermore, hydropower due to its associated reservoir storage, can provide flexibility and reliability for energy production in integrated energy systems. The storage capability of hydropower systems act as a regulating mechanism by which other intermittent and variable renewable energy sources (wind, wave, solar) can play a larger role in providing electricity of commercial quality. Minimizing water consumption for producing hydropower is critical given that overuse of water for energy production may result in a shortage of water for other purposes such as irrigation, navigation or fish passage. This paper presents a dimensional analysis for finding optimal flow discharge and optimal penstock diameter when designing impulse and reaction water turbines for hydropower systems. The objective of this analysis is to provide general insights for minimizing water consumption when producing hydropower. This analysis is based on the geometric and hydraulic characteristics of the penstock, the total hydraulic head and the desired power production. As part of this analysis, various dimensionless relationships between power production, flow discharge and head losses were derived. These relationships were used to withdraw general insights on determining optimal flow discharge and

  19. Energy balance in female distance runners.

    Science.gov (United States)

    Beidleman, B A; Puhl, J L; De Souza, M J

    1995-02-01

    Metabolic efficiency was assessed in ovulatory eumenorrheic female distance runners and untrained control subjects of similar age, body weight, and fat-free mass (FFM). Energy intake (EI) was estimated from 3-d dietary records. Energy expenditure (EE) was determined during the same 3-d period from individual heart rate oxygen uptake (HR/VO2) curves during rest and exercise, 24-h HR records, and the thermic effect of meals. The runners and control subjects did not differ in resting metabolic rate statistically adjusted for FFM (kJ/min), the thermic effect of a test meal (kJ/3 h), the energy cost of submaximal physical activity, or EI. EE was higher (P = 0.01) in the runners. Reported EI was lower than EE in both the runners (P = 0.007) and control subjects, (P = 0.006), resulting in energy deficits of -4131 +/- 1185 kJ/d and -1652 +/- 456 kJ/d, respectively. These female runners did not exhibit an enhanced metabolic efficiency compared with the control subjects. It is possible that the energy deficit for both the runners and control subjects was due to both restricted eating and underreporting during the measurement period. Additional studies using longer measurement periods, more sophisticated technology (ie, doubly labeled water, more subjects, and subjects of varying menstrual and energy intake status) are needed to truly answer this question.

  20. 76 FR 81929 - Small Hydropower Development in the United States; Notice of Small/Low-Impact Hydropower Webinar

    Science.gov (United States)

    2011-12-29

    ... Energy Regulatory Commission Small Hydropower Development in the United States; Notice of Small/Low-Impact Hydropower Webinar The Federal Energy Regulatory Commission will host a Small/Low- Impact... guidance on small/low- impact hydropower projects being developed in the Northeast region of the United...

  1. 75 FR 65012 - Small Hydropower Development in the United States; Notice of Small/Low-Impact Hydropower Webinar

    Science.gov (United States)

    2010-10-21

    .../Low- Impact Hydropower Webinar on November 10, 2010, from 12 noon to 1 p.m. Eastern Time. The webinar... introduce the new Small/Low- Impact Hydropower Program website and walk participants through all phases of... Energy Regulatory Commission Small Hydropower Development in the United States; Notice of Small/Low...

  2. The Influence of runner system on production of injection molds

    Directory of Open Access Journals (Sweden)

    Janostik Vaclav

    2016-01-01

    Full Text Available This experimental study describes the influence of runner system on rheological properties during the injection molding process. Economic effects on the amount of production are discussed as well. Autodesk Moldflow Synergy 2016 (Moldflow was used for the study of the injection process. Three suggestions of the runner system, cold runner system, hot runner system and the combination of cold–hot runner system have been promoted. These three variants underwent the rheological and economic analysis. As a result, recommendations for the application of the runner system for the required amount of production have been suggested

  3. Operation of hydropower generation systems in the Alps under future climate and socio-economic drivers

    Science.gov (United States)

    Anghileri, Daniela; Castelletti, Andrea; Burlando, Paolo

    2015-04-01

    Alpine hydropower systems are an important source of renewable energy for many countries in Europe. In Switzerland, for instance, they represent the most important domestic source of renewable energy (around 55%). However, future hydropower production may be threatened by unprecedented challenges, such as a decreasing water availability, due to climate change (CC) and associated glacier retreat, and uncertain operating conditions, such as future power needs and highly fluctuating demand on the energy market. This second aspect has gained increasingly relevance since the massive introduction of solar and wind generating systems in the portfolios of many European countries. Because hydropower systems have the potential to provide backup storage of energy to compensate for fluctuations that are typical, for instance, of solar and wind generation systems, it is important to investigate how the increased demand for flexible operation, together with climate change challenge and fluctuating markets, can impact their operating policies. The Swiss Competence Center on Supply of Electricity (www.sccer-soe.ch) has been recently established to explore new potential paths for the development of future power generation systems. In this context, we develop modelling and optimization tools to design and assess new operation strategies for hydropower systems to increase their reliability, flexibility, and robustness to future operation conditions. In particular, we develop an advanced modelling framework for the integrated simulation of the operation of hydropower plants, which accounts for CC-altered streamflow regimes, new demand and market conditions, as well as new boundary conditions for operation (e.g., aquatic ecosystem conservation). The model construction consists of two primary components: a physically based and spatially distributed hydrological model, which describes the relevant hydrological processes at the basin scale, and an agent based decision model, which

  4. Numerical analysis of solid–liquidtwo-phase turbulent flow in Francis turbine runner with splitter bladesin sandy water

    Directory of Open Access Journals (Sweden)

    Hua Hong

    2015-03-01

    Full Text Available As the key component of a hydroelectric power generation system, hydraulic turbine plays a decisive role in the overall performance of the system. There are many sandy rivers in the world, and turbines working in these rivers are seriously damaged. Therefore, the research of flow in sandy water has great theoretical significance and practical value. Based on the specific hydrological conditions of a hydropower station, the solid–liquid two-phase flow in the whole flow passage of a Francis turbine with splitter blades in sandy water was numerically studied. A geometric model of the whole flow passage of the Francis turbine was established on the basis of given design parameters. The solid–liquid two-phase turbulent flows in Francis turbine runner under three different loads were numerically analyzed by using this model. The three different loads are as follows: Condition 1: single unit with 1/4 load, Condition 2: single unit with 1/2 load, and Condition 3: single unit with full load. The distributions of pressure and sand concentration on the leading side and the suction side of the runner blades, as well as the velocity vector distribution of water and sand on the horizontal section of the runner, were obtained under different load conditions. Therefore, the damages to various flow passage components by sand can be qualitatively predicated under various conditions. To guarantee the safety and stability of the unit, the adverse conditions shall be avoided, which can provide certain reference for plant operation.

  5. Climate Risk in Southern and Eastern Africa's Hydropower Generation

    Science.gov (United States)

    Dalin, C.; Conway, D.; Landman, W.; Osborn, T.

    2016-12-01

    Hydropower comprises a major proportion of electricity production in southern and eastern Africa and is undergoing rapid expansion. Hydropower production in both regions is exposed to high levels of climate variability and regional linkages are strong, yet an understanding of aggregate climate risk is lacking. Here we map regions of coherent precipitation variability with current and planned (2030) hydropower sites, river basin configuration and regional energy grids to assess aggregate exposure to hydropower supply disruption. If fully implemented hydropower will be increasingly concentrated in the Nile basin in eastern Africa and the Zambezi basin in southern Africa. Regions of similar rainfall variability show close alignment with the main sites of hydropower. Future concentration of hydropower will greatly increase the concurrent risk of climate related electricity supply disruption. Nascent electricity sharing mechanisms could mitigate risk but face considerable political and infrastructural challenges.

  6. Hydropower development priority using MCDM method

    Energy Technology Data Exchange (ETDEWEB)

    Supriyasilp, Thanaporn [Department of Civil Engineering, Chiang Mai University, Chiang Mai 50200 (Thailand); Pongput, Kobkiat [Department of Water Resource Engineering, Kasetsart University, Bangkhen Campus, Bangkok 10900 (Thailand); Boonyasirikul, Thana [Electricity Generating Authority of Thailand, Bang Kruai, Nonthaburi 11130 (Thailand)

    2009-05-15

    Hydropower is recognized as a renewable and clean energy sources and its potential should be realized in an environmentally sustainable and socially equitable manner. Traditionally, the decision criteria when analyzing hydropower projects, have been mostly a technical and economical analysis which focused on the production of electricity. However, environmental awareness and sensitivity to locally affected people should also be considered. Multi-criteria decision analysis has been applied to study the potential to develop hydropower projects with electric power greater than 100 kW in the Ping River Basin, Thailand, and to determine the advantages and disadvantages of the projects in five main criteria: electricity generation, engineering and economics, socio-economics, environment, and stakeholder involvement. There are 64 potential sites in the study area. Criteria weights have been discussed and assigned by expert groups for each main criteria and subcriteria. As a consequence of weight assignment, the environmental aspect is the most important aspect in the view of the experts. Two scenarios using expert weight and fair weight have been studied to determine the priority for development of each project. This study has been done to assist policy making for hydropower development in the Ping River Basin. (author)

  7. Thayer Lake Hydropower Development -- Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Matousek, Mark [ORENCO Hydropower, Palo Alto, CA (United States)

    2017-06-30

    The Thayer Lake Hydropower Development (THLD) has been under study since the late 1970’s as Angoon explored opportunities to provide lower cost renewable power to the Community and avoid the high cost of diesel generation. Kootznoowoo Inc. (Kootznoowoo), the tribal corporation for Angoon’s current and past residents, was provided the rights by Congress to develop a hydropower project within the Admiralty Island National Monument. This grant (DE-EE0002504) by the Department of Energy’s (DOE’s) Office of Indian Energy and a matching grant from the Alaska Energy Authority (AEA) were provided to Kootznoowoo to enable the design, engineering and permitting of this hydropower project on Thayer Creek. Prior to the grant, the USFS had performed a final environmental impact statement (FEIS) and issued a Record of Decision (ROD) in 2009 for a 1.2 MW hydropower project on Thayer Creek that would Angoon’s needs with substantial excess capacity for growth. Kootznoowoo hired Alaska Power & Telephone (AP&T) in 2013 to manage this project and oversee its development. AP&T and its subcontractors under Kootznoowoo’s guidance performed several activities, aligned with the task plan defined in the grant.

  8. Relay Runners Catch The Rays

    CERN Multimedia

    2004-01-01

    Athletes sizzled around CERN on Wednesday 19 May at the 34th annual relay race. On one of the warmest days of the year so far, sunkissed competitors ran for the finish line and then straight for the drinks table. The Shabbys were on fire again, hurtling across the line first in a time of 10 min. 42.6 sec. and making an even stronger claim to being hailed as the traditional winners of the race with their fourth triumph in a row. Also on form were the Lynx Runners who won the Veteran's trophy, continuing their winning ways since 2002 and placing 29th overall. Ildefons Magrans of the ALICE Quarks on the Loose team ran the fastest 1000m in a time of 2 min. 47 sec. Second-placed Charmilles Technologies won the Open category in a time of 11 min. 03 sec., taking the prize for teams whose members work in different departments or who come from outside CERN. The OPALadies won the women's trophy and placed 48th. With 9 trophies up for grabs, more than 300 people in 55 teams ran the fun run, covering distances of 1000m ...

  9. Kenyan and Ethiopian distance runners: what makes them so good?

    Science.gov (United States)

    Wilber, Randall L; Pitsiladis, Yannis P

    2012-06-01

    Since the 1968 Mexico City Olympics, Kenyan and Ethiopian runners have dominated the middle- and long-distance events in athletics and have exhibited comparable dominance in international cross-country and road-racing competition. Several factors have been proposed to explain the extraordinary success of the Kenyan and Ethiopian distance runners, including (1) genetic predisposition, (2) development of a high maximal oxygen uptake as a result of extensive walking and running at an early age, (3) relatively high hemoglobin and hematocrit, (4) development of good metabolic "economy/efficiency" based on somatotype and lower limb characteristics, (5) favorable skeletal-muscle-fiber composition and oxidative enzyme profile, (6) traditional Kenyan/Ethiopian diet, (7) living and training at altitude, and (8) motivation to achieve economic success. Some of these factors have been examined objectively in the laboratory and field, whereas others have been evaluated from an observational perspective. The purpose of this article is to present the current data relative to factors that potentially contribute to the unprecedented success of Kenyan and Ethiopian distance runners, including recent studies that examined potential links between Kenyan and Ethiopian genotype characteristics and elite running performance. In general, it appears that Kenyan and Ethiopian distance-running success is not based on a unique genetic or physiological characteristic. Rather, it appears to be the result of favorable somatotypical characteristics lending to exceptional biomechanical and metabolic economy/efficiency; chronic exposure to altitude in combination with moderate-volume, high-intensity training (live high + train high), and a strong psychological motivation to succeed athletically for the purpose of economic and social advancement.

  10. The frequency of anemia and iron deficiency in the runner.

    Science.gov (United States)

    Balaban, E P; Cox, J V; Snell, P; Vaughan, R H; Frenkel, E P

    1989-12-01

    The current consensus is that runners commonly experience a mild anemia influenced by iron deficiency. We compared hematologic parameters of 72 (35 males and 37 females) runners with 48 (27 males and 21 females) nonrunners and assessed the impact of iron supplementation. Male runners had lower hemoglobin (Hb) values than male nonrunners (14.8 vs 15.3 g.dl-1) (P less than 0.05) regardless of iron usage. Female runners had higher (P = 0.05) Hb values than female controls (13.5 vs 12.8 g.dl-1). Female runners off iron had Hbs similar to controls off iron (P = 0.30). Iron parameters (total serum iron, TSI; total iron-binding capacity, TIBC; percent saturation of the TIBC, %sat TIBC; and serum ferritin) of runners vs controls, runners vs runners (on or off iron), and nonrunners vs nonrunners (on or off iron) were comparable except 1) male runners off iron had lower (P less than 0.05) %sat TIBC values (26%) than male runners on iron (34%) and 2) female runners taking iron had ferritin values (32 ng.ml-1) similar to those of female nonrunners taking iron (39 ng.ml-1) but higher (P less than 0.05) than their counterparts off iron (15 and 15 ng.ml-1, respectively). This study concludes that running affects Hb in a variable manner and suggests that the runner's iron status is similar to that of the general population.

  11. Analysis of information systems for hydropower operations: Executive summary

    Science.gov (United States)

    Sohn, R. L.; Becker, L.; Estes, J.; Simonett, D.; Yeh, W.

    1976-01-01

    An analysis was performed of the operations of hydropower systems, with emphasis on water resource management, to determine how aerospace derived information system technologies can effectively increase energy output. Better utilization of water resources was sought through improved reservoir inflow forecasting based on use of hydrometeorologic information systems with new or improved sensors, satellite data relay systems, and use of advanced scheduling techniques for water release. Specific mechanisms for increased energy output were determined, principally the use of more timely and accurate short term (0-7 days) inflow information to reduce spillage caused by unanticipated dynamic high inflow events. The hydrometeorologic models used in predicting inflows were examined in detail to determine the sensitivity of inflow prediction accuracy to the many variables employed in the models, and the results were used to establish information system requirements. Sensor and data handling system capabilities were reviewed and compared to the requirements, and an improved information system concept was outlined.

  12. Strength and Conditioning Habits of Competitive Distance Runners.

    Science.gov (United States)

    Blagrove, Richard C; Brown, Nicola; Howatson, Glyn; Hayes, Philip R

    2017-10-10

    Blagrove, RC, Brown, N, Howatson, G, and Hayes, PR. Strength and conditioning habits of competitive distance runners. J Strength Cond Res XX(X): 000-000, 2017-Targeted strength and conditioning (S&C) programs can potentially improve performance and reduce injury risk factors in competitive runners. However, S&C practices of distance runners are unknown. This study aimed to explore S&C practices of competitive middle- and long-distance runners and examined whether reported frequency of injuries was influenced by training behaviors. One thousand eight hundred eighty-three distance runners (≥15 years old) completed an online survey. All runners who raced competitively were included in data analysis (n = 667). Distance runners mainly engaged with S&C activities to lower risk of injury (63.1%) and improve performance (53.8%). The most common activities used were stretching (86.2%) and core stability exercises (70.2%). Resistance training (RT) and plyometric training (PT) were used by 62.5 and 35.1% of runners, respectively. Junior (under-20) runners include PT, running drills, and circuit training more so than masters runners. Significantly more international standard runners engaged in RT, PT, and fundamental movement skills training compared with competitive club runners. Middle-distance (800-3,000 m) specialists were more likely to include RT, PT, running drills, circuit training, and barefoot exercises in their program than longer-distance runners. Injury frequency was associated with typical weekly running volume and run frequency. Strength and conditioning did not seem to confer a protection against the number of injuries the runners experienced. Practitioners working with distance runners should critically evaluate the current S&C practices of their athletes, to ensure that activities prescribed have a sound evidence-based rationale.

  13. Hydropower resources at risk: The status of hydropower regulation and development - 1997

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, R.T.; Hunt, J.A. [Richard Hunt Associates, Inc., Annapolis, MD (United States)

    1997-09-01

    This report documents today`s hydropower licensing and development status based on published data as follows: (a) Federal Energy Regulatory Commission (FERC) databases, maintained by FERC`s Office of Hydropower Licensing, of: (1) operating FERC-regulated projects, federal projects, and known unlicensed projects; (2) surrendered licenses; and, (3) recent licensing and relicensing actions; (b) Energy Information Administration (EIA) data on installed capacity and generation from 1949 through 1995 for the various resources used to produce electricity in the U.S.; and, (c) FERC licensing orders, and environmental assessments or environmental impact statements for each individual project relicensed since 1980. The analysis conducted to prepare this paper includes the effects of all FERC hydropower licensing actions since 1980, and applies those findings to estimate the costs of hydropower licensing and development activity for the next 15 years. It also quantifies the national cost of hydropower regulation. The future estimates are quite conservative. The are presented in 1996 dollars without speculating on the effects of future inflation, license surrenders, conditions imposed through open-ended license articles, license terms greater than 30 years, or low water years. Instead, they show the most directly predictable influences on licensing outcomes using actual experiences since ECPA (after 1986).

  14. DO RUNNING SHOES PROTECT ALL RUNNERS?

    Directory of Open Access Journals (Sweden)

    Benjamin E.J. Spurgeon

    2005-12-01

    Full Text Available Running is a prevalent physical activity in today's health-conscious society. Over the course of a 1-mile run an individual will make approximately 1600 footstrikes. At the time of contact between foot and ground, impact forces and pronation place large stresses on the structures of the lower extremity. Exposure to repeated impact loading is linked to the development of runners' injuries, including joint degeneration and osteoarthritis (Dekel and Weissman, 1978. Pronation increases the stress in joints, muscles and tendons and is also connected to runners' injuries (James et al., 1978; Denoth, 1986; Stacoff et al., 1988. To prevent injury, running shoes are designed to reduce both impact forces and pronation. However, these innovations in shoe design might not benefit all runners. There are two main groups of runners: rearfoot strikers and midfoot strikers. Rearfoot strikers make initial ground contact with their heel, whereas midfoot strikers make initial ground contact with the mid-region of their foot. Eighty percent of runners are rearfoot strikers with the remainder being midfoot strikers (Kerr et al., 1983. So far, running shoe research has been focused only on rearfoot strikers. Thus, there is a good understanding of the shoe design requirements for these runners. For example, research has shown that the hardness and geometry of shoe-soles can be modified to reduce impact forces and pronation in rearfoot strikers (Luethi and Stacoff, 1987; Nigg and Morlock, 1987. Conversely, midfoot strikers have received no attention from running shoe research. This suggests that there is little understanding of the available techniques to reduce impact forces and pronation in these runners. Indeed, research has shown more pronation in midfoot strikers than in rearfoot strikers for the same shoe (De Wit et al., 1995. Hence, midfoot strikers might be running in poorly designed shoes which predispose them to injury. Do running shoes protect all runners

  15. Hydropower in Turkey: potential and market assessment

    Energy Technology Data Exchange (ETDEWEB)

    2010-10-15

    The Turkish hydropower market provides huge opportunities for investors and suppliers. Successful market entry is not easy, however, as the market is still not fully liberalized, the need for local intelligence is large and the competition is increasing. There are also potential political, reputational and environmental risks, typical for an emerging economy. The World Bank global 'Ease of doing business' ranking (2010), ranks Turkey as number 73 of 183 countries. (Author)

  16. Biofuel Crops Expansion: Evaluating the Impact on the Agricultural Water Scarcity Costs and Hydropower Production with Hydro Economic Modeling

    Science.gov (United States)

    Marques, G.

    2015-12-01

    Biofuels such as ethanol from sugar cane remain an important element to help mitigate the impacts of fossil fuels on the atmosphere. However, meeting fuel demands with biofuels requires technological advancement for water productivity and scale of production. This may translate into increased water demands for biofuel crops and potential for conflicts with incumbent crops and other water uses including domestic, hydropower generation and environmental. It is therefore important to evaluate the effects of increased biofuel production on the verge of water scarcity costs and hydropower production. The present research applies a hydro-economic optimization model to compare different scenarios of irrigated biofuel and hydropower production, and estimates the potential tradeoffs. A case study from the Araguari watershed in Brazil is provided. These results should be useful to (i) identify improved water allocation among competing economic demands, (ii) support water management and operations decisions in watersheds where biofuels are expected to increase, and (iii) identify the impact of bio fuel production in the water availability and economic value. Under optimized conditions, adoption of sugar cane for biofuel production heavily relies on the opportunity costs of other crops and hydropower generation. Areas with a lower value crop groups seem more suitable to adopt sugar cane for biofuel when the price of ethanol is sufficiently high and the opportunity costs of hydropower productions are not conflicting. The approach also highlights the potential for insights in water management from studying regional versus larger scales bundled systems involving water use, food production and power generation.

  17. Superior endurance performance in aging mountain runners.

    Science.gov (United States)

    Burtscher, Martin; Förster, Holger; Burtscher, Johannes

    2008-01-01

    Oxygen uptake at the anaerobic threshold (VO(2)AT) is considered as the main determinant for endurance performance in humans. Endurance performance steeply decreases with aging but seems to be kept exceedingly high in elite mountain runners. To obtain the age- and gender-related upper limits of endurance performance in this sport, we analyzed the results of the World Masters Athletic Championships in Mountain Running 2007. Additionally, to investigate the relationship between the individual VO(2)AT values and running times, laboratory tests were performed in 10 mountain runners. The World Championships race times of the first 5 finishers of the 5-year age groups did not differ significantly from 35 to 49 years. The corresponding mean (+/- SD) values of the VO(2)AT were 68.0 +/- 1.7 ml/min/kg in males and 58.1 +/- 1.9 ml/min/kg in females. In the following age groups up to 70+ there was a decrease in the VO(2)AT of 29.1% in males and 33.9% in females. Thus, at the beginning of the 3rd millennium, elite mountain runners demonstrate that VO(2)AT and probably also VO(2max) may be held at top levels in humans up to the age of 45-49 years in both sexes. Despite the following decrease, endurance capacity remains about 3.5-fold higher in elite mountain runners up to 70+ years when compared to their untrained peers. Copyright 2008 S. Karger AG, Basel.

  18. Nutrition Education for Elite Female Runners.

    Science.gov (United States)

    Clark, Nancy; And Others

    1988-01-01

    A survey of the dietary habits of 115 elite female runners revealed that some did not eat wisely, pointing out nutrition education needs for these subjects in the areas of sweets, vitamin and mineral supplementation, intake of red meat, body weight and body image, eating disorders, calorie intake, and amenorrhea and stress fractures. (Author/CB)

  19. Calcaneal Bone Mass Modification in Recreational Runners.

    Science.gov (United States)

    Escamilla-Martínez, Elena; Martínez-Nova, Alfonso; Gómez-Martín, Beatriz; Sánchez-Rodríguez, Raquel; Fernández-Seguín, Lourdes María; Pedrera-Zamorano, Juan Diego

    2016-11-01

    The calcaneus is the bone of the foot that first receives the impact of running, generating vibrations that might have a positive effect in modifying the trabecular bone mass. The objective of this study was to determine the variation in calcaneal bone density in runners during a 6-month training season, comparing it with a control sample. Bone density of the heel was measured in 33 male recreational runners by means of a contact ultrasonic bone analyzer. Measurements were made on three occasions during a training season: at the beginning, at 350 km, and at 700 km. All of the runners wore the same model of running shoes during this period. Measurements of bone density were also made in a control sample of 62 men who did not engage in physical exercise. There was a significant decrease in mean calcaneal bone density over the course of the training season (from 86.1 dB/MHz to 83.2 dB/MHz; P = .006), but no significant differences with the control sample value (from 80.7 dB/MHz to 81.1 dB/MHz; P = .314). The runners' body composition changed during the study period, with lean mass increasing and fat mass decreasing. Distance running seems to have a negative effect on calcaneal bone mass density during the course of a 700-km training season.

  20. Metabolic factors limiting performance in marathon runners.

    Directory of Open Access Journals (Sweden)

    Benjamin I Rapoport

    2010-10-01

    Full Text Available Each year in the past three decades has seen hundreds of thousands of runners register to run a major marathon. Of those who attempt to race over the marathon distance of 26 miles and 385 yards (42.195 kilometers, more than two-fifths experience severe and performance-limiting depletion of physiologic carbohydrate reserves (a phenomenon known as 'hitting the wall', and thousands drop out before reaching the finish lines (approximately 1-2% of those who start. Analyses of endurance physiology have often either used coarse approximations to suggest that human glycogen reserves are insufficient to fuel a marathon (making 'hitting the wall' seem inevitable, or implied that maximal glycogen loading is required in order to complete a marathon without 'hitting the wall.' The present computational study demonstrates that the energetic constraints on endurance runners are more subtle, and depend on several physiologic variables including the muscle mass distribution, liver and muscle glycogen densities, and running speed (exercise intensity as a fraction of aerobic capacity of individual runners, in personalized but nevertheless quantifiable and predictable ways. The analytic approach presented here is used to estimate the distance at which runners will exhaust their glycogen stores as a function of running intensity. In so doing it also provides a basis for guidelines ensuring the safety and optimizing the performance of endurance runners, both by setting personally appropriate paces and by prescribing midrace fueling requirements for avoiding 'the wall.' The present analysis also sheds physiologically principled light on important standards in marathon running that until now have remained empirically defined: The qualifying times for the Boston Marathon.

  1. Neural-net based coordinated stabilizing control for the exciter and governor loops of low head hydropower plants

    Energy Technology Data Exchange (ETDEWEB)

    Djukanovic, M.; Novicevic, M.; Dobrijevic, D.; Babic, B. [Electrical Engineering Inst. Nikola Tesla, Belgrade (Yugoslavia); Sobajic, D.J. [Electric Power Research Inst., Palo Alto, CA (United States); Pao, Y.H. [Case Western Reserve Univ., Cleveland, OH (United States)]|[AI WARE, Inc., Cleveland, OH (United States)

    1995-12-01

    This paper presents a design technique of a new adaptive optimal controller of the low head hydropower plant using artificial neural networks (ANN). The adaptive controller is to operate in real time to improve the generating unit transients through the exciter input, the guide vane position and the runner blade position. The new design procedure is based on self-organization and the predictive estimation capabilities of neural-nets implemented through the cluster-wise segmented associative memory scheme. The developed neural-net based controller (NNC) whose control signals are adjusted using the on-line measurements, can offer better damping effects for generator oscillations over a wide range of operating conditions than conventional controllers. Digital simulations of hydropower plant equipped with low head Kaplan turbine are performed and the comparisons of conventional excitation-governor control, state-space optimal control and neural-net based control are presented. Results obtained on the non-linear mathematical model demonstrate that the effects of the NNC closely agree with those obtained using the state-space multivariable discrete-time optimal controllers.

  2. Neuro-fuzzy controller of low head hydropower plants using adaptive-network based fuzzy inference system

    Energy Technology Data Exchange (ETDEWEB)

    Djukanovic, M.B. [Inst. Nikola Tesla, Belgrade (Yugoslavia). Dept. of Power Systems; Calovic, M.S. [Univ. of Belgrade (Yugoslavia). Dept. of Electrical Engineering; Vesovic, B.V. [Inst. Mihajlo Pupin, Belgrade (Yugoslavia). Dept. of Automatic Control; Sobajic, D.J. [Electric Power Research Inst., Palo Alto, CA (United States)

    1997-12-01

    This paper presents an attempt of nonlinear, multivariable control of low-head hydropower plants, by using adaptive-network based fuzzy inference system (ANFIS). The new design technique enhances fuzzy controllers with self-learning capability for achieving prescribed control objectives in a near optimal manner. The controller has flexibility for accepting more sensory information, with the main goal to improve the generator unit transients, by adjusting the exciter input, the wicket gate and runner blade positions. The developed ANFIS controller whose control signals are adjusted by using incomplete on-line measurements, can offer better damping effects to generator oscillations over a wide range of operating conditions, than conventional controllers. Digital simulations of hydropower plant equipped with low-head Kaplan turbine are performed and the comparisons of conventional excitation-governor control, state-feedback optimal control and ANFIS based output feedback control are presented. To demonstrate the effectiveness of the proposed control scheme and the robustness of the acquired neuro-fuzzy controller, the controller has been implemented on a complex high-order non-linear hydrogenerator model.

  3. Failures during Load-Frequency Control Maneuvers in an Upgraded Hydropower Plant: Causes, Identification of Causes and Solution Proposals

    Directory of Open Access Journals (Sweden)

    Juan I. Pérez-Díaz

    2015-09-01

    Full Text Available The objective of this paper is to investigate the cause of several unexpected high amplitude oscillations that occurred in the surge tank water level of a real hydropower plant during secondary load-frequency control (LFC maneuvers, after the replacement of the turbine runner, and to propose solutions that allow the power plant to continue providing secondary LFC in a safe and reliable manner. For this purpose, a simulation model has been developed and calibrated from data gathered during several on-site tests. Two different solutions are proposed in order to cope with the observed problem: using a state-dependent load change rate limiter or modifying the hydro turbine governor gains; the turbine governor remains the same as before the runner replacement. The proposed solutions are tested against a set of realistic secondary LFC signals by means of simulations and compared to each other as a function of the probability that the surge tank water level descends below a minimum safe level and the quality of the secondary LFC response. The results presented in the paper demonstrate the validity of the methodology proposed to determine the state-dependent ramp limit, as well as its effectiveness to prevent the surge tank drawdown and to provide clear insight into the trade-off between response quality and power plant safety.

  4. Biomechanical Implications of Training Volume and Intensity in Aging Runners.

    Science.gov (United States)

    Paquette, Max R; DeVita, Paul; Williams, D S Blaise

    2017-10-09

    Running speed is slower in middle-aged compared to younger runners due to reduced ankle but not hip and knee kinetic output. Running-specific training helps attenuate age-related declines in measures of endurance, muscle strength and gait speed. Considering the adaptability of the human body in response to imposed stresses, maintaining training volume and intensity may play a role in modifying running biomechanics in middle-aged runners. To compare running biomechanics between young and middle-aged runners when controlling for the confounding effects of training volume and intensity. 15 middle-aged runners, 15 young runners with similar training volume as the middle-aged group and, 15 young runners with similar preferred training paces (i.e. intensity) as the middle-aged runners participated in the study. Lower limb joint kinetics were calculated from kinematic and ground reaction force data during over-ground running at a submaximal speed and compared among groups. Middle-aged runners ran with similar peak ankle power compared to volume-matched younger runners although peak plantarflexor moment was 10.5% lower in the middle aged group (p = 0.046; Cohen's d = 0.78). Middle-aged runners ran with similar ankle plantarflexor moment and joint power compared to training pace-matched young runners. As expected, no age-related differences were observed in hip and knee kinetics when training volume or pace were matched between age groups. These results suggest that training pace may be more effective in attenuating age-related declines in plantarflexor kinetics in middle-aged runners. From these findings, we propose the hypothesis that both training volume and training pace may play a role in maintaining plantarflexor kinetics but that training pace may have a greater impact on ankle plantarflexor kinetics in middle-aged runners.

  5. A feasibility and implementation model of small-scale hydropower ...

    African Journals Online (AJOL)

    2016-10-04

    Oct 4, 2016 ... Several other site selection parameters were used to evaluate the Kwa Madiba potential small-scale hydropower site, which include accessibility by vehicle, current electrical grid con- nection and future electrical grid connectivity, environmental impact and social impact. Okot (2013) evaluates hydropower.

  6. Climate Change and Hydropower Challenges In Southern Africa ...

    African Journals Online (AJOL)

    The purpose of this study is to address climate change impacts that challenge hydropower production and distribution in southern Africa. Change in temperature and precipitations due to climate change will affect rivers catchments runoff as well as hydropower dams and transmission lines in southern Africa. Evidences of ...

  7. Hydropower Regulatory and Permitting Information Desktop (RAPID) Toolkit

    Energy Technology Data Exchange (ETDEWEB)

    Levine, Aaron L [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-12-19

    Hydropower Regulatory and Permitting Information Desktop (RAPID) Toolkit presentation from the WPTO FY14-FY16 Peer Review. The toolkit is aimed at regulatory agencies, consultants, project developers, the public, and any other party interested in learning more about the hydropower regulatory process.

  8. The potential impacts of climate change on hydropower: An ...

    African Journals Online (AJOL)

    Osborne

    Climate change has the potential to affect hydropower generation by either increasing or reducing ... proven, mature, efficient and cost competitive renewable energy source. Hydropower requires relatively high initial investment but has low operation costs and it offers ... areas to global warming because water resources are.

  9. Future hydropower production in the Lower Zambezi under possible ...

    African Journals Online (AJOL)

    For such a long-term development, the possible impact of climate change on the future production is of essential interest. The objective of the presented study is to assess hydropower generation in the 21st century for a future hydropower development scenario under two climate scenarios. The two climate scenarios ...

  10. U.S. hydropower resource assessment for Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Conner, A.M.; Francfort, J.E.

    1998-08-01

    The US Department of Energy is developing an estimate of the undeveloped hydropower potential in the US. The Hydropower Evaluation Software (HES) is a computer model that was developed by the Idaho National Engineering and Environmental Laboratory for this purpose. HES measures the undeveloped hydropower resources available in the US, using uniform criteria for measurement. The software was developed and tested using hydropower information and data provided by the Southwestern Power Administration. It is a menu-driven program that allows the personal computer user to assign environmental attributes to potential hydropower sites, calculate development suitability factors for each site based on the environmental attributes present, and generate reports based on these suitability factors. This report describes the resource assessment results for the State of Idaho.

  11. U.S. hydropower resource assessment for Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Conner, A.M.; Francfort, J.E.

    1997-12-01

    The US Department of Energy is developing an estimate of the undeveloped hydropower potential in the US. The Hydropower Evaluation Software (HES) is a computer model that was developed by the Idaho National Engineering Laboratory for this purpose. HES measures the undeveloped hydropower resources available in the US, using uniform criteria for measurement. The software was developed and tested using hydropower information and data provided by the Southwestern Power Administration. It is a menu-driven program that allows the personal computer user to assign environmental attributes to potential hydropower sites, calculate development suitability factors for each site based on the environmental attributes present, and generate reports based on these suitability factors. This report describes the resource assessment results for the State of Ohio.

  12. U.S. hydropower resource assessment for Michigan

    Energy Technology Data Exchange (ETDEWEB)

    Conner, A.M.; Francfort, J.E.

    1998-02-01

    The US Department of Energy is developing an estimate of the undeveloped hydropower potential in the US. The Hydropower Evaluation Software (HES) is a computer model that was developed by the Idaho National Engineering and Environmental Laboratory for this purpose. HES measures the undeveloped hydropower resources available in the US, using uniform criteria for measurement. The software was developed and tested using hydropower information and data provided by the Southwestern Power Administration. It is a menu-driven program that allows the personal computer user to assign environmental attributes to potential hydropower sites, calculate development suitability factors for each site based on the environmental attributes present, and generate reports based on these suitability factors. This report describes the resource assessment results for the State of Michigan.

  13. U.S. hydropower resource assessment for New York

    Energy Technology Data Exchange (ETDEWEB)

    Conner, A.M.; Francfort, J.E.

    1998-08-01

    The US Department of Energy is developing an estimate of the undeveloped hydropower potential in the United States. The Hydropower Evaluation Software (HES) is a computer model that was developed by the Idaho National Engineering and Environmental Laboratory for this purpose. HES measures the undeveloped hydropower resources available in the United States, using uniform criteria for measurement. The software was developed and tested using hydropower information and data provided by the Southwestern Power Administration. It is a menu-driven program that allows the personal computer user to assign environmental attributes to potential hydropower sites, calculate development suitability factors for each site based on the environmental attributes present, and generate reports based on these suitability factors. This report describes the resource assessment results for the State of New York.

  14. U.S. hydropower resource assessment for Connecticut

    Energy Technology Data Exchange (ETDEWEB)

    Francfort, J.E.; Rinehart, B.N.

    1995-07-01

    The Department of Energy is developing an estimate of the undeveloped hydro-power potential in the United States. The Hydropower Evaluation Software (HES) is a computer model that was developed by the Idaho National Engineering Laboratory for this purpose. The software measures the undeveloped hydropower resources available in the United States, using uniform criteria for measurement. The software was developed and tested using hydropower information and data provided by the Southwestern Power Administration. It is a menu-driven software program that allows the personal computer user to assign environmental attributes to potential hydropower sites, calculate development suitability factors for each site based on the environmental attributes present, and generate reports based on these suitability factors. This report details the resource assessment results for the State of Connecticut.

  15. U.S. hydropower resource assessment for Maine

    Energy Technology Data Exchange (ETDEWEB)

    Francfort, J.E.; Rinehart, B.N.

    1995-07-01

    The Department of Energy is developing an estimate of the undeveloped hydro-power potential in the United States. The Hydropower Evaluation Software (HES) is a computer model that was developed by the Idaho National Engineering Laboratory for this purpose. The software measures the undeveloped hydropower resources available in the United States, using uniform criteria for measurement. The software was developed and tested using hydropower information and data provided by the Southwestern Power Administration. It is a menu-driven software program that allows the personal computer user to assign environmental attributes to potential hydropower sites, calculate development suitability factors for each site based on the environmental attributes present, and generate reports based on these suitability factors. This report details the resource assessment results for the State of Maine.

  16. U.S. hydropower resource assessment for Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Conner, A.M.; Francfort, J.E.

    1997-10-01

    The US Department of Energy is developing an estimate of the undeveloped hydropower potential in the US. The Hydropower Evaluation Software (HES) is a computer model that was developed by the Idaho National Engineering Laboratory for this purpose. HES measures the undeveloped hydropower resources available in the US, using uniform criteria for measurement. The software was developed and tested using hydropower information and data provided by the Southwestern Power Administration. It is a menu-driven program that allows the personal computer user to assign environmental attributes to potential hydropower sites, calculate development suitability factors for each site based on the environmental attributes present, and generate reports based on these suitability factors. This report describes the resource assessment results for the State of Nevada.

  17. U.S. hydropower resource assessment for Illinois

    Energy Technology Data Exchange (ETDEWEB)

    Conner, A.M.; Francfort, J.E.

    1997-01-01

    The US Department of Energy is developing an estimate of the undeveloped hydropower potential in the US. The Hydropower Evaluation Software (HES) is a computer model that was developed by the Idaho National Engineering Laboratory for this purpose. HES measures the undeveloped hydropower resources available in the US, using uniform criteria for measurement. The software was developed and tested using hydropower information and data provided by the Southwestern Power Administration. It is a menu-driven program that allows the personal computer user to assign environmental attributes to potential hydropower sites, calculate development suitability factors for each site based on the environmental attributes present, and generate reports based on these suitability factors. This report describes the resource assessment results for the State of Illinois.

  18. Efficient Operation of a Multi-purpose Reservoir in Chile: Integration of Economic Water Value for Irrigation and Hydropower

    Science.gov (United States)

    Olivares, M. A.; Gonzalez Cabrera, J. M., Sr.; Moreno, R.

    2016-12-01

    Operation of hydropower reservoirs in Chile is prescribed by an Independent Power System Operator. This study proposes a methodology that integrates power grid operations planning with basin-scale multi-use reservoir operations planning. The aim is to efficiently manage a multi-purpose reservoir, in which hydroelectric generation is competing with other water uses, most notably irrigation. Hydropower and irrigation are competing water uses due to a seasonality mismatch. Currently, the operation of multi-purpose reservoirs with substantial power capacity is prescribed as the result of a grid-wide cost-minimization model which takes irrigation requirements as constraints. We propose advancing in the economic co-optimization of reservoir water use for irrigation and hydropower at the basin level, by explicitly introducing the economic value of water for irrigation represented by a demand function for irrigation water. The proposed methodology uses the solution of a long-term grid-wide operations planning model, a stochastic dual dynamic program (SDDP), to obtain the marginal benefit function for water use in hydropower. This marginal benefit corresponds to the energy price in the power grid as a function of the water availability in the reservoir and the hydrologic scenarios. This function allows capture technical and economic aspects to the operation of hydropower reservoir in the power grid and is generated with the dual variable of the power-balance constraint, the optimal reservoir operation and the hydrologic scenarios used in SDDP. The economic value of water for irrigation and hydropower are then integrated into a basin scale stochastic dynamic program, from which stored water value functions are derived. These value functions are then used to re-optimize reservoir operations under several inflow scenarios.

  19. Impact of startup scheme on Francis runner life expectancy

    Energy Technology Data Exchange (ETDEWEB)

    Gagnon, M; Tahan, S A; Bocher, P [Department of Mechanical Engineering, Ecole de technologie superieure (ETS) 1100, rue Notre-Dame Ouest, Montreal (Canada); Thibault, D, E-mail: martin.gagnon.8@ens.etsmtl.c [Institut de recherche d' Hydro-Quebec (IREQ), 1800, boul. Lionel-Boulet, Varennes, J3X 1S1 (Canada)

    2010-08-15

    Francis runners are subject to complex dynamic forces which might lead to eventual blade cracking and the need for corrective measure. Damage due to cracks in runner blades are usually not a safety issues but might generate unexpected down time and high repair cost. Avoiding the main damaging operating conditions is often the only option left to plant operators to maximize the life expectancy of their runner. The startup scheme is one of the available parameter which is controlled by the end user and could be used to minimize the damage induced to the runner. In this study, two startup schemes have been used to investigate life expectancy of Francis runner using in situ measurements. The results obtained show that the induced damage during the startup event could be significantly reduced with change to the startup scheme. In our opinion, an optimization of the startup scheme with regard to fatigue damage could extend significantly the life expectancy and the reliability of Francis runner.

  20. 76 FR 30937 - Small Hydropower Development in the United States; Notice of Small/Low-Impact Hydropower Webinar

    Science.gov (United States)

    2011-05-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Small Hydropower Development in the United States; Notice of Small/Low-Impact Hydropower Webinar The Federal Energy Regulatory Commission (FERC) will host a Small/ Low-Impact...

  1. Relationship between cytokines and running economy in marathon runners

    Directory of Open Access Journals (Sweden)

    Luna Junior Luiz Antonio

    2016-01-01

    Full Text Available Running economy (RE, expresses the relationship between the energy cost of running (Cr and the work performed by a runner and is an predictor of performance. Given the intense effort of marathon runners during training and competition and the dearth of studies that address performance and cytokines in this population, the objective of the current study was to investigate the relationship between RE and cytokines in marathon runners.

  2. Older Runners Retain Youthful Running Economy Despite Biomechanical Differences

    Science.gov (United States)

    Beck, Owen N.; Kipp, Shalaya; Roby, Jaclyn M.; Grabowski, Alena M.; Kram, Rodger; Ortega, Justus D.

    2015-01-01

    Purpose Sixty-five years of age typically marks the onset of impaired walking economy. However, running economy has not been assessed beyond the age of 65 years. Furthermore, a critical determinant of running economy is the spring-like storage and return of elastic energy from the leg during stance, which is related to leg stiffness. Therefore, we investigated whether runners over the age of 65 years retain youthful running economy and/or leg stiffness across running speeds. Methods Fifteen young and fifteen older runners ran on a force-instrumented treadmill at 2.01, 2.46, and 2.91 m·s−1. We measured their rates of metabolic energy consumption (i.e. metabolic power), ground reaction forces, and stride kinematics. Results There were only small differences in running economy between young and older runners across the range of speeds. Statistically, the older runners consumed 2–9% less metabolic energy than the young runners across speeds (p=0.012). Also, the leg stiffness of older runners was 10–20% lower than that of young runners across the range of speeds (p=0.002) and in contrast to the younger runners, the leg stiffness of older runners decreased with speed (prunning economy despite biomechanical differences. It may be that vigorous exercise, such as running, prevents the age related deterioration of muscular efficiency, and therefore may make everyday activities easier. PMID:26587844

  3. The fastest runner on artificial legs: different limbs, similar function?

    National Research Council Canada - National Science Library

    Peter G. Weyand; Matthew W. Bundle; Craig P. McGowan; Alena Grabowski; Mary Beth Brown; Rodger Kram; Hugh Herr

    2009-01-01

    The recent competitive successes of a bilateral, transtibial amputee sprint runner who races with modern running prostheses has triggered an international controversy regarding the relative function...

  4. Older Runners Retain Youthful Running Economy despite Biomechanical Differences.

    Science.gov (United States)

    Beck, Owen N; Kipp, Shalaya; Roby, Jaclyn M; Grabowski, Alena M; Kram, Rodger; Ortega, Justus D

    2016-04-01

    Sixty-five years of age typically marks the onset of impaired walking economy. However, running economy has not been assessed beyond the age of 65 yr. Furthermore, a critical determinant of running economy is the spring-like storage and return of elastic energy from the leg during stance, which is related to leg stiffness. Therefore, we investigated whether runners older than 65 yr retain youthful running economy and/or leg stiffness across running speeds. Fifteen young and 15 older runners ran on a force-instrumented treadmill at 2.01, 2.46, and 2.91 m·s(-1). We measured their rates of metabolic energy consumption (i.e., metabolic power), ground reaction forces, and stride kinematics. There were only small differences in running economy between young and older runners across the range of speeds. Statistically, the older runners consumed 2% to 9% less metabolic energy than the young runners across speeds (P = 0.012). Also, the leg stiffness of older runners was 10% to 20% lower than that of young runners across the range of speeds (P = 0.002), and in contrast to the younger runners, the leg stiffness of older runners decreased with speed (P economy despite biomechanical differences. It may be that vigorous exercise, such as running, prevents the age related deterioration of muscular efficiency and, therefore, may make everyday activities easier.

  5. Studies on water turbine runner which fish can pass through: In case of single stage axial runner

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Yukimari; Maeda, Takao; Nagoshi, Osamu [Mie Univ., Tsu (Japan); Ieda, Kazuma [Toyoda Autoloom Co. Ltd., Hekinan, Aichi (Japan); Shinma, Hisako [National Research Inst. of Aquaculture, Tamaki, Mie (Japan); Hagimoto, Michiko [Minolta Camera Co. Ltd., Osaka (Japan)

    1994-12-31

    The relationship between water turbine runner design and operation and the safe passage of fish through the turbine is studied. The kinds of fish used in the tests are a dace, a sweet fish and a small salmon. A single stage axial runner is used. The velocity and pressure distributions were measured inside the turbine casing and along the casing wall. Many pictures showing fish passing through the rotating runner were taken and analyzed. The swimming speed of the fish was examined from video recordings. Fish pass through the runner more rapidly when they can determine and choose the easier path. Injury and mortality of fish are affected by the runner speed and the location of impact of the runner on the fish body.

  6. Present and future hydropower scheduling in Statkraft

    Science.gov (United States)

    Bruland, O.

    2012-12-01

    Statkraft produces close to 40 TWH in an average year and is one of the largest hydropower producers in Europe. For hydropower producers the scheduling of electricity generation is the key to success and this depend on optimal use of the water resources. The hydrologist and his forecasts both on short and on long terms are crucial to this success. The hydrological forecasts in Statkraft and most hydropower companies in Scandinavia are based on lumped models and the HBV concept. But before the hydrological model there is a complex system for collecting, controlling and correcting data applied in the models and the production scheduling and, equally important, routines for surveillance of the processes and manual intervention. Prior to the forecasting the states in the hydrological models are updated based on observations. When snow is present in the catchments snow surveys are an important source for model updating. The meteorological forecast is another premise provider to the hydrological forecast and to get as precise meteorological forecast as possible Statkraft hires resources from the governmental forecasting center. Their task is to interpret the meteorological situation, describe the uncertainties and if necessary use their knowledge and experience to manually correct the forecast in the hydropower production regions. This is one of several forecast applied further in the scheduling process. Both to be able to compare and evaluate different forecast providers and to ensure that we get the best available forecast, forecasts from different sources are applied. Some of these forecasts have undergone statistical corrections to reduce biases. The uncertainties related to the meteorological forecast have for a long time been approached and described by ensemble forecasts. But also the observations used for updating the model have a related uncertainty. Both to the observations itself and to how well they represent the catchment. Though well known, these

  7. Pacing accuracy in collegiate and recreational runners.

    Science.gov (United States)

    Green, J Matthew; Sapp, Amber L; Pritchett, Robert C; Bishop, Phil A

    2010-02-01

    To examine runners' ability to produce a prescribed pace, we compared prescribed versus actual 400 m splits for collegiate (COL, n = 12) and recreational runners (REC, n = 16). Participants completed a VO(2max) trial and on a 400 m track, three 3,200 m time trials. During three subsequent sessions, participants completed 800 m warm-up; then, based on their fastest 3,200 m steady pace, subjects completed six laps total at three prescribed paces: (a) 2x 400 m at 7% slower than steady pace (SLO), (b) 2x 400 m at steady pace (AT) and (c) 2x 400 m at 7% faster than steady pace (FAS). Instructions were to complete the sets of two laps in prescribed times (e.g., 75 s per 400 m) (no feedback). Deviation scores (absolute value of difference: prescribed vs. actual time) (s) for each 400 m lap were compared using a 2 (group) x 3 (trial) repeated measures ANOVA. Main effects for deviations among trials SLO (7.3 +/- 6.5), AT (6.6 +/- 6.9) and FAS (6.2 +/- 5.7) were not significantly different (p > 0.05). However, group main effect for deviation scores was significantly (p runners resulted in improved pacing accuracy.

  8. Perceived Muscle Soreness in Recreational Female Runners.

    Science.gov (United States)

    Burnett, D; Smith, K; Smeltzer, C; Young, K; Burns, S

    The purpose of this study was to determine if rating of perceived exertion correlated with perceived muscle soreness during delayed onset muscle soreness (DOMS) in female runners. This study examined the pre and post running economy measures and perceived muscle soreness before and after a 30-min downhill run (DHR) at -15% grade and 70% of the subjects predetermined maximum oxygen uptake (VO2 peak). Six female recreational runners (mean age = 24.5) performed level running at 65%, 75%, and 85% of their VO2 peak prior to DHR (baseline economy runs), as well as, immediately following and 4 successive days after the DHR. Subjective response related to perceived muscle soreness increased significantly from a mean of 2 (pre DHR) to 62 (2 days post DHR) on a scale of 1-100. Creatine kinase levels and oxygen consumption increased post DHR compared to pre DHR. Rating of perceived exertion did not change between the economy runs performed prior to or at any point after the DHR. Perceived muscle soreness is a better tool than the RPE scale to monitor exercise intensity for recreational female runners during periods of DOMS and running economy is adversely affected by DOMS.

  9. Experiences with environmentally adapted Kaplan runners; Erfarenheter med miljoeanpassade Kaplanloephjul

    Energy Technology Data Exchange (ETDEWEB)

    Ukonsaari; Jan

    2012-08-15

    This study concerns environmentally adapted Kaplan runners, which have no oil for lubricating the blade regulation mechanisms and bearings. The runners are water or air filled with self lubricated bearings. Recent design also includes regulation system pressure increase and servo motor placement below runner centre and environmentally adapted synthetic ester as hydraulic fluid. These together with power output increase and efficiency optimization are suspected sources of poor runner function. Of 37 runners 43 % have had some kind of problem and 30 % bearing or mechanism related ones. When the axial blade bearing problems are excluded the problems occurred at 16 %. Deeper look into the design of newer runners shows that only bronze based runner hubs is significantly more problem dense regarding regulation mechanisms (50 %). Hidden figures of increased runner regulation forces are suspected. All problems cannot be explained and the young machines limit the experiences. The working group's opinion and bring ups of historical and present examples during the work show evidence that the old oil filled runners function is far from perfect, nor the life length. The future is not with oil filled runner hubs. Main parts of the discovered problems have been solved and can be resolved by thorough design analysis. One future concern is what effects the recent design changes will cause due to increase demand for power output changes including the number of starts and stops. That is why the working group's recommendation is to put joint effort into material fatigue and in which a first step is to identify the real forces the runners are exposed to.

  10. Bridging the Information Gap: Remote Sensing and Micro Hydropower Feasibility in Data-Scarce Regions

    Science.gov (United States)

    Muller, Marc Francois

    Access to electricity remains an impediment to development in many parts of the world, particularly in rural areas with low population densities and prohibitive grid extension costs. In that context, community-scale run-of-river hydropower---micro-hydropower---is an attractive local power generation option, particularly in mountainous regions, where appropriate slope and runoff conditions occur. Despite their promise, micro hydropower programs have generally failed to have a significant impact on rural electrification in developing nations. In Nepal, despite very favorable conditions and approximately 50 years of experience, the technology supplies only 4% of the 10 million households that do not have access to the central electricity grid. These poor results point towards a major information gap between technical experts, who may lack the incentives or local knowledge needed to design appropriate systems for rural villages, and local users, who have excellent knowledge of the community but lack technical expertise to design and manage infrastructure. Both groups suffer from a limited basis for evidence-based decision making due to sparse environmental data available to support the technical components of infrastructure design. This dissertation draws on recent advances in remote sensing data, stochastic modeling techniques and open source platforms to bridge that information gap. Streamflow is a key environmental driver of hydropower production that is particularly challenging to model due to its stochastic nature and the complexity of the underlying natural processes. The first part of the dissertation addresses the general challenge of Predicting streamflow in Ungauged Basins (PUB). It first develops an algorithm to optimize the use of rain gauge observations to improve the accuracy of remote sensing precipitation measures. It then derives and validates a process-based model to estimate streamflow distribution in seasonally dry climates using the stochastic

  11. Modular Hydropower Engineering and Pilot Scale Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Chesser, Phillip C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-09-01

    Emrgy has developed, prototyped and tested a modular hydropower system for renewable energy generation. ORNL worked with Emrgy to demonstrate the use of additive manufacturing in the production of the hydrofoils and spokes for the hydrokinetic system. Specifically, during Phase 1 of this effort, ORNL printed and finished machined patterns for both the hydrofoils and spokes that were subsequently used in a sand casting manufacturing process. Emrgy utilized the sand castings for a pilot installation in Denver, CO, where the parts represented an 80% cost savings from the previous prototype build that was manufactured using subtractive manufacturing. In addition, the castings were completed with ORNL’s newly developed AlCeMg alloy that will be tested for performance improvements including higher corrosion resistance in a water application than the 6160 alloy used previously

  12. Acute renal failure in four Comrades Marathon runners ingesting the ...

    African Journals Online (AJOL)

    Objectives. To evaluate common factors associated with the development of acute renal failure (ARF) in Comrades Marathon runners. Methods. This was a retrospective case series of 4 runners hospitalised post-race with ARF in the 89 km 2010 Comrades Marathon. The outcome measures were incidence of analgesic use, ...

  13. An elite runner with cerebral palsy: cost of running determines ...

    African Journals Online (AJOL)

    ... AL) appears to account for much of the difference in performance compared to able-bodied runners. The results provide both insight into the physiological limitations of runners with CP and support for the Joyner model of competitive running performance. Keywords: biomechanics, athletic training, exercise performance, ...

  14. Development of a 5kw Francis Turbine Runner Using Computation ...

    African Journals Online (AJOL)

    A small scale Francis turbine runner for a turbine located at Awba dam in the University of Ibadan with designed head and flow rate of 6m and 0.244m3/s is designed. The basic design of the Francis turbine runner is completed based on basic fluid dynamics turbo machinery principles. A 2-D and 3-D steady state, ...

  15. Physique characteristics of world-class African long distance runners

    African Journals Online (AJOL)

    The purposes of the study were to describe the physique characteristics (body composition and somatotypes) of world class African male and female long distance (LD) runners and to determine by means of a discriminant analysis which variables best discriminated among the male and female LD runners. Anthropometric ...

  16. Myocardial infarction & sudden death in recreational master marathon runners.

    Science.gov (United States)

    Finn, Suzanne Elizabeth; Coviello, Jessica

    2011-02-01

    This review of the current literature on myocardial infarction and sudden death in recreational master marathon runners aims to help raise awareness of the scope of the problem to primary care providers, and to provide guidelines for educating and screening in recreational master marathon runners.

  17. Cost of enlarged operating zone for an existing Francis runner

    Science.gov (United States)

    Monette, Christine; Marmont, Hugues; Chamberland-Lauzon, Joël; Skagerstrand, Anders; Coutu, André; Carlevi, Jens

    2016-11-01

    Traditionally, hydro power plants have been operated close to best efficiency point, the more stable operating condition for which they have been designed. However, because of changes in the electricity market, many hydro power plants operators wish to operate their machines differently to fulfil those new market needs. New operating conditions can include whole range operation, many start/stops, extensive low load operation, synchronous condenser mode and power/frequency regulation. Many of these new operating conditions may impose more severe fatigue damage than the traditional base load operation close to best efficiency point. Under these conditions, the fatigue life of the runner may be significantly reduced and reparation or replacement cost might occur sooner than expected. In order to design reliable Francis runners for those new challenging operating scenarios, Andritz Hydro has developed various proprietary tools and design rules. These are used within Andritz Hydro to design mechanically robust Francis runners for the operating scenarios fulfilling customer's specifications. To estimate residual life under different operating scenarios of an existing runner designed years ago for best efficiency base load operation, Andritz Hydro's design rules and tools would necessarily lead to conservative results. While the geometry of a new runner can be modified to fulfil all conservative mechanical design rules, the predicted fatigue life of an existing runner under off-design operating conditions may appear rather short because of the conservative safety factor included in the calculations. The most precise and reliable way to calculate residual life of an existing runner under different operating scenarios is to perform a strain gauge measurement campaign on the runner. This paper presents the runner strain gage measurement campaign of a mid-head Francis turbine over all the operating conditions available during the test, the analysis of the measurement signals

  18. Hydropower's Contribution to Energy Security

    Energy Technology Data Exchange (ETDEWEB)

    Altinbilek, D.; Abdel-Malek, R.; Devernay, J.M.; Gill, R.; Leney, S.; Moss, Terry; Schiffer, H.P.; Taylor, R.M.

    2007-07-01

    The role of hydropower within mixed power systems is analysed from the point of view of both quantitative and qualitative performance. Interrelationships with all other generation technologies are discussed and synergies identified. Resources, sustainability criteria and investment challenges are reviewed in the context of development. The objective of the paper is to define hydropower's contribution within the clean, clever and competitive markets of the future.

  19. Estimating the future ice sheet hydropower potential in Paakitsoq, Ilulissat, West Greenland

    DEFF Research Database (Denmark)

    Ahlstrøm, Andreas P.; Mottram, R.H.; Nielsen, C.

    2008-01-01

    of meltwater during the summer season. However, geometrical changes in the ice sheet, for example due to a retreat or an advance of the ice sheet margin, could change the hydrological catchment within the ice sheet. Such a change would have a devastating economical impact as a hydropower plant is a significant...... long-term investment for an Arctic community of modest population. Here we present a new bedrock and surface map of the Paakitsoq/Swiss Camp part of the Greenland ice sheet and a prediction of the future discharge up to 2080 AD using regional climate model output, dynamic ice sheet modelling...

  20. Iron excess in recreational marathon runners.

    Science.gov (United States)

    Mettler, S; Zimmermann, M B

    2010-05-01

    Iron deficiency and anemia may impair athletic performance, and iron supplements are commonly consumed by athletes. However, iron overload should be avoided because of the possible long-term adverse health effects. We investigated the iron status of 170 male and female recreational runners participating in the Zürich marathon. Iron deficiency was defined either as a plasma ferritin (PF) concentration or =4.5 (functional iron deficiency). After excluding subjects with elevated C-reactive protein concentrations, iron overload was defined as PF >200 microg/l. Iron depletion was found in only 2 out of 127 men (1.6% of the male study population) and in 12 out of 43 (28.0%) women. Functional iron deficiency was found in 5 (3.9%) and 11 (25.5%) male and female athletes, respectively. Body iron stores, calculated from the sTfR/PF ratio, were significantly higher (Prunners. Median PF among males was 104 microg/l, and the upper limit of the PF distribution in males was 628 microg/l. Iron overload was found in 19 out of 127 (15.0%) men but only 2 out of 43 in women (4.7%). Gender (male sex), but not age, was a predictor of higher PF (Prunners but in runners had signs of iron overload. Although iron supplements are widely used by athletes in an effort to increase performance, our findings indicate excess body iron may be common in male recreational runners and suggest supplements should only be used if tests of iron status indicate deficiency.

  1. Running, Being, and Beijing—An Existential Exploration of a Runner Identity

    DEFF Research Database (Denmark)

    Ronkainen, Noora; Harrison, Marlen Elliot; Ryba, Tatiana

    2014-01-01

    In this research, we explore the negotiation of a conflicted runner identity in a Finnish runner's short-term migration to Beijing, China. We examine the historical and cultural construction of the runner identity and discuss the current discourses that constitute the modern runner subjectivities...

  2. Addressing biogenic greenhouse gas emissions from hydropower in LCA.

    Science.gov (United States)

    Hertwich, Edgar G

    2013-09-03

    The ability of hydropower to contribute to climate change mitigation is sometimes questioned, citing emissions of methane and carbon dioxide resulting from the degradation of biogenic carbon in hydropower reservoirs. These emissions are, however, not always addressed in life cycle assessment, leading to a bias in technology comparisons, and often misunderstood. The objective of this paper is to review and analyze the generation of greenhouse gas emissions from reservoirs for the purpose of technology assessment, relating established emission measurements to power generation. A literature review, data collection, and statistical analysis of methane and CO2 emissions are conducted. In a sample of 82 measurements, methane emissions per kWh hydropower generated are log-normally distributed, ranging from micrograms to 10s of kg. A multivariate regression analysis shows that the reservoir area per kWh electricity is the most important explanatory variable. Methane emissions flux per reservoir area are correlated with the natural net primary production of the area, the age of the power plant, and the inclusion of bubbling emissions in the measurement. Even together, these factors fail to explain most of the variation in the methane flux. The global average emissions from hydropower are estimated to be 85 gCO2/kWh and 3 gCH4/kWh, with a multiplicative uncertainty factor of 2. GHG emissions from hydropower can be largely avoided by ceasing to build hydropower plants with high land use per unit of electricity generated.

  3. Anthropometric and functional characteristics of Colombian elite long-distance runners

    Directory of Open Access Journals (Sweden)

    Ramírez-Vélez, Robinson

    2015-07-01

    Full Text Available Objective: To evaluate the anthropometric and physical performance characteristics of elite long-distance runners. Methods: A cross-sectional study in 19 male competitive long-distance runners of national level (age 28.2 ± 6.9 years. A total of 24 anthropometric variables were measured according to the International Society for the Advancement of Kinanthropometry (ISAK statements. The Heath-Carter method and the formula proposed by Siri, Matiegka, Jackson and Pollock were used to calculate the somatotype and the body composition, respectively. Ergospirometry VO (2 max, Vertical Jump Test and the Wingate Test were used as functional indicators. Results: Regarding body composition, we found fat mass percentage 13.3 ± 3.2; muscle mass 47.3 ± 2.5%, and body adiposity index 24.1 ± 3.3. Somatotype profile was the mesomorphic-balanced (3.6-4.0-2.1. Mean values of functional tests with their standard deviations were: VO(2 máx (mL•kg-1•min-1 42.6 ± 8.1; anaerobic power 106.0 ± 31.8 kg•s-1, and anaerobic capacity 6501.0 ± 1831.6 K/jul. Conclusion: These results may provide a profile of long-distance runners that can be used as training targets for developing athletes. The results may also provide information for training and tactical emphasis.

  4. Failure analysis of a Francis turbine runner

    Energy Technology Data Exchange (ETDEWEB)

    Frunzaverde, D; Campian, V [Research Center in Hydraulics, Automation and Heat Transfer, ' Eftimie Murgu' University of Resita P-ta Traian Vuia 1-4, RO-320085, Resita (Romania); Muntean, S [Centre of Advanced Research in Engineering Sciences, Romanian Academy - Timisoara Branch Bv. Mihai Viteazu 24, RO-300223, Timisoara (Romania); Marginean, G [University of Applied Sciences Gelsenkirchen, Neidenburger Str. 10, 45877 Gelsenkirchen (Germany); Marsavina, L [Department of Strength, ' Politehnica' University of Timisoara, Bv. Mihai Viteazu 1, RO-300222, Timisoara (Romania); Terzi, R; Serban, V, E-mail: gabriela.marginean@fh-gelsenkirchen.d, E-mail: d.frunzaverde@uem.r [Ramnicu Valcea Subsidiary, S.C. Hidroelectrica S.A., Str. Decebal 11, RO-240255, Ramnicu Valcea (Romania)

    2010-08-15

    The variable demand on the energy market requires great flexibility in operating hydraulic turbines. Therefore, turbines are frequently operated over an extended range of regimes. Francis turbines operating at partial load present pressure fluctuations due to the vortex rope in the draft tube cone. This phenomenon generates strong vibrations and noise that may produce failures on the mechanical elements of the machine. This paper presents the failure analysis of a broken Francis turbine runner blade. The failure appeared some months after the welding repair work realized in situ on fatigue cracks initiated near to the trailing edge at the junction with the crown, where stress concentration occurs. In order to determine the causes that led to the fracture of the runner blade, the metallographic investigations on a sample obtained from the blade is carried out. The metallographic investigations included macroscopic and microscopic examinations, both performed with light and scanning electron microscopy, as well as EDX - analyses. These investigations led to the conclusion, that the cracking of the blade was caused by fatigue, initiated by the surface unevenness of the welding seam. The failure was accelerated by the hydrogen embrittlement of the filling material, which appeared as a consequence of improper welding conditions. In addition to the metallographic investigations, numerical computations with finite element analysis are performed in order to evaluate the deformation and stress distribution on blade.

  5. Marathon runners: how do they age?

    Science.gov (United States)

    Trappe, Scott

    2007-01-01

    Marathon running performance among men and women is generally fastest, as indicated by world record performances, when individuals are 25-35 years old. The time to complete a marathon gradually increases with age, with substantial losses in performance after the age of 70 years. A decline in cardiovascular capacity of 0.5% per decade occurs in highly trained distance runners, while a 1.0% and 1.5% decline per decade occurs in moderately trained and untrained individuals, respectively. In middle-aged veteran runners, skeletal muscle continues to have high aerobic potential, while a decline in muscle cell size and contractile performance are apparent. These changes in the skeletal muscle profile may contribute to distance running performance with age. The changes in physiological function and running performance with age are closely related to the level of distance run training. Current research supports the concept that continued running late into life attenuates a decline in physiological function with age and is beneficial for overall health.

  6. Metaheuristic Approaches for Hydropower System Scheduling

    Directory of Open Access Journals (Sweden)

    Ieda G. Hidalgo

    2015-01-01

    Full Text Available This paper deals with the short-term scheduling problem of hydropower systems. The objective is to meet the daily energy demand in an economic and safe way. The individuality of the generating units and the nonlinearity of their efficiency curves are taken into account. The mathematical model is formulated as a dynamic, mixed integer, nonlinear, nonconvex, combinatorial, and multiobjective optimization problem. We propose two solution methods using metaheuristic approaches. They combine Genetic Algorithm with Strength Pareto Evolutionary Algorithm and Ant Colony Optimization. Both approaches are divided into two phases. In the first one, to maximize the plant’s net generation, the problem is solved for each hour of the day (static dispatch. In the second phase, to minimize the units’ switching on-off, the day is considered as a whole (dynamic dispatch. The proposed methodology is applied to two Brazilian hydroelectric plants, in cascade, that belong to the national interconnected system. The nondominated solutions from both approaches are presented. All of them meet demand respecting the physical, electrical, and hydraulic constraints.

  7. Advanced manufacturing technologies of large martensitic stainless steel castings with ultra low carbon and high cleanliness

    Directory of Open Access Journals (Sweden)

    Lou Yanchun

    2010-11-01

    Full Text Available The key manufacturing technologies associated with composition, microstructure, mechanical properties, casting quality and key process control for large martensitic stainless steel castings are involved in this paper. The achievements fully satisfied the technical requirements of the large 700 MW stainless steel hydraulic turbine runner for the Three Gorges Hydropower Station, and become the major technical support for the design and manufacture of the largest 700 MW hydraulic turbine generator unit in the world developed through our own efforts. The characteristics of a new high yield to tensile strength (Rp0.2/Rm ratio and high obdurability martensitic stainless steel with ultra low carbon and high cleanliness are also described. Over the next ten years, the large martensitic stainless steel castings and advanced manufacturing technologies will see a huge demand in clean energy industry such as nuclear power, hydraulic power at home and abroad. Therefore, the new high yield o tensile strength (Rp0.2/Rm ratio and high obdurability martensitic stainless steel materials, the fast and flexible manufacturing technologies of large size castings, and new environment friendly sustainable process will face new challenges and opportunities.

  8. Small hydropower for rural electrification in South Africa - using experiences from other African countries

    CSIR Research Space (South Africa)

    Jonker Klunne, WE

    2009-10-01

    Full Text Available Local hydropower sources can play an important role in the electrification of rural areas in South Africa remote from the national electricity grid. To ensure the sustainability of hydropower developments it is essential that lessons learned...

  9. Multi-model assessment of global hydropower and cooling water discharge potential under climate change

    NARCIS (Netherlands)

    van Vliet, M. T H; van Beek, L. P H; Eisner, S.; Flörke, M.; Wada, Y.; Bierkens, M. F P

    2016-01-01

    Worldwide, 98% of total electricity is currently produced by thermoelectric power and hydropower. Climate change is expected to directly impact electricity supply, in terms of both water availability for hydropower generation and cooling water usage for thermoelectric power. Improved understanding

  10. Oral Contraceptives and Bone Health in Female Runners

    National Research Council Canada - National Science Library

    Kelsey, Jennifer

    2000-01-01

    .... This study is a two-year randomized trial of the effects of oral contraceptives on bone mass and stress fracture incidence among 150 female competitive distance runners in the age range 18-25 years...

  11. Oral Contraceptives and Bone Health in Female Runners

    National Research Council Canada - National Science Library

    Kelsey, Jennifer

    1999-01-01

    .... This study is a two-year randomized trial of the effects of oral contraceptives on bone mass and stress fracture incidence among 150 female competitive cross country runners in the age range 18-25 years...

  12. Cardiac responses to exercise in child distance runners.

    Science.gov (United States)

    Rowland, T; Goff, D; Popowski, B; DeLuca, P; Ferrone, L

    1998-08-01

    Cardiovascular responses to exercise in trained endurance child athletes have been largely unexplored. Doppler echocardiography was utilized to compare cardiac variables during progressive upright cycle exercise to exhaustion in trained male prepubertal distance runners (n = 8) and untrained control boys (n = 14). Athletes demonstrated a greater maximal stroke index and cardiac index. Stroke volume rose progressively with increasing workloads in the runners but remained stable beyond low intensities in the non-athletes. No significant differences in stroke volume were observed between the two groups at rest. This contrasts with the greater resting stroke volumes typically seen in adult endurance athletes compared to non-athletes. Likewise, values for maximal stroke index were less in the child runners than those typically seen in trained adults. This study demonstrated that the stroke volume response to exercise differs in boy runners compared to non-athletes. The findings also suggest quantitative differences in such responses between prepubertal and young adult athletes.

  13. Being Thin Could Boost Stress Fracture Risk in Female Runners

    Science.gov (United States)

    ... news/fullstory_166853.html Being Thin Could Boost Stress Fracture Risk in Female Runners Researcher says less muscle ... low body weight are more likely to have stress fractures and take longer to recover from them, according ...

  14. Footfall patterns of a runner with an Achilles tendon rupture

    Directory of Open Access Journals (Sweden)

    Daniel Jandacka

    2017-12-01

    Conclusion: Footfall patterns can be an adaptation to reduce the loading on a previously injured AT. It appears that runners may consider using a rearfoot footfall pattern during running to reduce the stress on the AT.

  15. Study of speed endurance middle distance runners

    Directory of Open Access Journals (Sweden)

    R.V. Golovaschenko

    2013-12-01

    Full Text Available Purpose : To investigate the boost performance speed endurance runners who specialize in middle-distance running . Material and methods : The study involved team members Vinnytsia region in an amount of 44 people, whose average age was 20,2 ± 2,1 years. Classes are held during the 21-day mesocycle, 5 times a week, twice a day. Things were aimed at enhancing the development of indicators of special speed endurance. Results : The dynamics of the running speed of the model segments that characterize speed endurance athletes. Proved that the improved running 400 meter intervals helps reduce travel time competitive distance of 1500 meters. Conclusion : The use of the program contributes to higher speed endurance, which determines the result in the women's 1,500 meters.

  16. Effect of age and performance on pacing of marathon runners

    OpenAIRE

    Nikolaidis PT; Knechtle B

    2017-01-01

    Pantelis Theodoros Nikolaidis,1 Beat Knechtle2,3 1Exercise Physiology Laboratory, Attiki, Greece; 2Gesundheitszentrum St. Gallen, St. Gallen, 3Institute of Primary Care, University of Zurich, Zurich, Switzerland Abstract: Pacing strategies in marathon runners have previously been examined, especially with regard to age and performance level separately. However, less information about the age × performance interaction on pacing in age-group runners exists. The aim of the present stud...

  17. Quantifying the Value of Hydropower in the Electric Grid. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Key, T. [Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

    2013-02-01

    The report summarizes a 3-year DOE study focused on defining value of hydropower assets in a changing electric grid. The study looked at existing large hydropower operations in the U.S., models for different electricity futures, markets, costs of existing and new technologies as well as trends related to hydropower investments in other parts of the world.

  18. Small hydropower in Southern Africa – an overview of five countries in the region

    NARCIS (Netherlands)

    Jonker Klunne, Wim

    2013-01-01

    This paper looks at the status of small hydropower in Lesotho, Mozambique, South Africa, Swaziland and Zimbabwe. For each country, an overview will be given of the electricity sector and the role of hydropower, the potential for small hydropower and the expected future of this technology. Small

  19. 18 CFR 141.14 - Form No. 80, Licensed Hydropower Development Recreation Report.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Form No. 80, Licensed Hydropower Development Recreation Report. 141.14 Section 141.14 Conservation of Power and Water Resources... Hydropower Development Recreation Report. The form of the report, Licensed Hydropower Development Recreation...

  20. State Models to Incentivize and Streamline Small Hydropower Development

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, Taylor [National Renewable Energy Lab. (NREL), Golden, CO (United States); Levine, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States); Johnson, Kurt [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-10-31

    In 2016, the hydropower fleet in the United States produced more than 6 percent (approximately 265,829 gigawatt-hours [GWh]) of the total net electricity generation. The median-size hydroelectric facility in the United States is 1.6 MW and 75 percent of total facilities have a nameplate capacity of 10 MW or less. Moreover, the U.S. Department of Energy's Hydropower Vision study identified approximately 79 GW hydroelectric potential beyond what is already developed. Much of the potential identified is at low-impact new stream-reaches, existing conduits, and non-powered dams with a median project size of 10 MW or less. To optimize the potential and value of small hydropower development, state governments are crafting policies that provide financial assistance and expedite state and federal review processes for small hydroelectric projects. This report analyzes state-led initiatives and programs that incentivize and streamline small hydroelectric development.

  1. Regulatory Approaches for Adding Capacity to Existing Hydropower Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Levine, Aaron L. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Curtis, Taylor L. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kazerooni, Borna [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-10-24

    In 2015, hydroelectric generation accounted for more than 6 percent of total net electricity generation in the United States and 46 percent of electricity generation from all renewables. The United States has considerable hydroelectric potential beyond what is already being developed. Nearly 7 GW of this potential is found by adding capacity to existing hydropower facilities. To optimize the value of hydroelectric generation, the U.S. Department of Energy's Hydropower Vision Study highlights the importance of adding capacity to existing facilities. This report provides strategic approaches and considerations for Federal Energy Regulatory Commission licensed and exempt hydropower facilities seeking to increase generation capacity, which may include increases from efficiency upgrades. The regulatory approaches reviewed for this report include capacity and non-capacity amendments, adding capacity during relicensing, and adding capacity when converting a license to a 10-MW exemption.

  2. A Holistic Framework for Environmental Flows Determination in Hydropower Contexts

    Energy Technology Data Exchange (ETDEWEB)

    McManamay, Ryan A [ORNL; Bevelhimer, Mark S [ORNL

    2013-05-01

    Among the ecological science community, the consensus view is that the natural flow regime sustains the ecological integrity of river systems. This prevailing viewpoint by many environmental stakeholders has progressively led to increased pressure on hydropower dam owners to change plant operations to affect downstream river flows with the intention of providing better conditions for aquatic biological communities. Identifying the neccessary magnitude, frequency, duration, timing, or rate of change of stream flows to meet ecological needs in a hydropower context is challenging because the ecological responses to changes in flows may not be fully known, there are usually a multitude of competing users of flow, and implementing environmental flows usually comes at a price to energy production. Realistically, hydropower managers must develop a reduced set of goals that provide the most benefit to the identified ecological needs. As a part of the Department of Energy (DOE) Water Power Program, the Instream Flow Project (IFP) was carried out by Oak Ridge National Laboratory (ORNL), Pacific Northwest National Laboratory (PNNL), and Argon National Laboratory (ANL) as an attempt to develop tools aimed at defining environmental flow needs for hydropower operations. The application of these tools ranges from national to site-specific scales; thus, the utility of each tool will depend on various phases of the environmental flow process. Given the complexity and sheer volume of applications used to determine environmentally acceptable flows for hydropower, a framework is needed to organize efforts into a staged process dependent upon spatial, temporal, and functional attributes. By far, the predominant domain for determining environmental flows related to hydropower is within the Federal Energy Regulatory Commission (FERC) relicensing process. This process can take multiple years and can be very expensive depending on the scale of each hydropower project. The utility of such a

  3. Exemplary Design Envelope Specification for Standard Modular Hydropower Technology

    Energy Technology Data Exchange (ETDEWEB)

    Witt, Adam M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Smith, Brennan T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Tsakiris, Achilleas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Papanicolaou, Thanos [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Pries, Jason L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Burress, Timothy A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Stewart, Kevin M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lee, Kyutae [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); DeNeale, Scott T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bevelhimer, Mark S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pracheil, Brenda M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McManamay, Ryan A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ekici, Kivanc [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Kutz, Benjamin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Curd, Shelaine L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bishop, Norm [Knight Piesold, Denver, CO (United States); Welch, Tim [U.S. Department of Energy (DOE), Washington, DC (United States). Office of Energy Efficiency and Renewable Energy (EERE); Rabon, Daniel [U.S. Department of Energy (DOE), Washington, DC (United States). Office of Energy Efficiency and Renewable Energy (EERE); Fernandez, Alisha [McKeown and Associates, Moberly, MO (United States)

    2017-02-01

    Hydropower is an established, affordable renewable energy generation technology supplying nearly 18% of the electricity consumed globally. A hydropower facility interacts continuously with the surrounding water resource environment, causing alterations of varying magnitude in the natural flow of water, energy, fish, sediment, and recreation upstream and downstream. A universal challenge in facility design is balancing the extraction of useful energy and power system services from a stream with the need to maintain ecosystem processes and natural environmental function. On one hand, hydroelectric power is a carbon-free, renewable, and flexible asset to the power system. On the other, the disruption of longitudinal connectivity and the artificial barrier to aquatic movement created by hydraulic structures can produce negative impacts that stress fresh water environments. The growing need for carbon-free, reliable, efficient distributed energy sources suggests there is significant potential for hydropower projects that can deploy with low installed costs, enhanced ecosystem service offerings, and minimal disruptions of the stream environment.

  4. Arterial stiffness and wave reflections in marathon runners.

    Science.gov (United States)

    Vlachopoulos, Charalambos; Kardara, Despina; Anastasakis, Aris; Baou, Katerina; Terentes-Printzios, Dimitrios; Tousoulis, Dimitris; Stefanadis, Christodoulos

    2010-09-01

    Regular aerobic exercise has beneficial effects on the cardiovascular system. Marathon running is an aerobic and extremely vigorous exercise. Arterial stiffness and wave reflections are independent predictors of cardiovascular risk. We investigated the acute effect of marathon race on aortic stiffness and wave reflections, as well as possible chronic alterations of these indexes in marathon runners. We studied 49 marathon runners (age 38 +/- 9 years) and 46 recreationally active control subjects (age 37 +/- 5 years). To investigate the acute effect of marathon race, a subgroup of 20 runners was evaluated after the race as well. Aortic stiffness was evaluated with carotid-femoral pulse wave velocity (PWV) and wave reflections with augmentation index (AIx). Marathon runners had significantly higher systolic, diastolic, pulse (both aortic and brachial), and mean pressures compared to controls (P Marathon runners had significantly higher PWV (6.89 m/s vs. 6.33 m/s, P Marathon race caused a significant fall in both AIx (12.2% vs. -5.8%, P marathon race, whereas aortic stiffness was not altered. Moreover, marathon runners have increased aortic stiffness and pressures, whereas wave reflections indexes do not differ compared to controls.

  5. Outrunning the risks: a behavioral risk profile of runners.

    Science.gov (United States)

    Heath, G W; Kendrick, J S

    1989-01-01

    There is a need to assess better the relationship between physical activity and other health behaviors through population-based studies. Using the state-based Behavioral Risk Factor Surveillance System, we examined the behavioral risk factors of smoking, alcohol use, hypertension detection, obesity, seat-belt use, and physical activity in 2,412 runners and 26,538 nonrunners. Our analyses demonstrated marked differences in behavioral risk profiles between runners and nonrunners. Runners, regardless of the amount of running, were more likely to be nonsmokers, be of normal weight, be normotensive, and regularly use seat belts than were nonrunners of similar age and sex. Patterns of alcohol use were not different when comparing male runners with male nonrunners. However, female runners were more likely to drink and drive and to use alcohol on a chronic basis compared to their nonrunning counterparts. The "runner's lifestyle" may convey a certain level of protection from chronic disorders that are associated with these risk factors. However, further prospective studies are needed to examine in more detail the relationship of running to the risks and/or benefits for improved health.

  6. Aerobic exercise capacity at sea level and at altitude in Kenyan boys, junior and senior runners compared with Scandinavian runners.

    Science.gov (United States)

    Saltin, B; Larsen, H; Terrados, N; Bangsbo, J; Bak, T; Kim, C K; Svedenhag, J; Rolf, C J

    1995-08-01

    The aim of this study was to characterize Kenyan runners in regard to their oxygen uptake and blood and ammonia responses when running. Untrained Kenyan boys (14.2 +/- 0.2 years) and Scandinavian runners were included for comparison. The studies were performed at altitude (approximately 2.000 m.a.s.l.) and, for several Kenyan and Scandinavian runners, at sea level as well. At altitude sedentary adolescent Kenyan boys had a mean maximal oxygen uptake (VO2max) of 47 (44-51) ml.kg-1.min-1, whereas similarly aged boys regularly walking or running but not training for competition reached above 62 (58-71) ml.kg-1.min-1 in VO2max. Kenyan runners in active training had 68 +/- 1.4 ml.kg-1.min-1 at altitude and 79.9 +/- 1.4 ml.kg-1.min-1 at sea level, with individuals reaching 85 ml.kg-1.min-1. The best Scandinavian runners were not significantly different from the Kenyan runners in VO2max both at altitude and at sea level, but none of the Scandinavians reached as high individual values as observed for some Kenyan runners. The running efficiency, determined as the oxygen cost at a given running speed, was less in the Kenyan runners, and the difference became more pronounced when body weight was expressed in ml.kg-0.75 min-1. Blood lactate concentration was in general lower in the Kenyan than in the Scandinavian runners, and the Kenyans also had extremely low ammonia accumulation in the blood even at very high exercise intensities. It is concluded that it is the physical activity during childhood, combined with intense training as teenagers that brings about the high VO2max observed in some Kenyan runners. Their high aerobic capacity, as well as their good running economy, makes them such superior runners. In addition, their low blood lactate and ammonia accumulation in blood when running may also be contributing factors.

  7. Simulation and Modeling Capability for Standard Modular Hydropower Technology

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Kevin M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Smith, Brennan T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Witt, Adam M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); DeNeale, Scott T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bevelhimer, Mark S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pries, Jason L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Burress, Timothy A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kao, Shih-Chieh [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mobley, Miles H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lee, Kyutae [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Curd, Shelaine L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Tsakiris, Achilleas [Univ. of Tennessee, Knoxville, TN (United States); Mooneyham, Christian [Univ. of Tennessee, Knoxville, TN (United States); Papanicolaou, Thanos [Univ. of Tennessee, Knoxville, TN (United States); Ekici, Kivanc [Univ. of Tennessee, Knoxville, TN (United States); Whisenant, Matthew J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Welch, Tim [US Department of Energy, Washington, DC (United States); Rabon, Daniel [US Department of Energy, Washington, DC (United States)

    2017-08-01

    Grounded in the stakeholder-validated framework established in Oak Ridge National Laboratory’s SMH Exemplary Design Envelope Specification, this report on Simulation and Modeling Capability for Standard Modular Hydropower (SMH) Technology provides insight into the concepts, use cases, needs, gaps, and challenges associated with modeling and simulating SMH technologies. The SMH concept envisions a network of generation, passage, and foundation modules that achieve environmentally compatible, cost-optimized hydropower using standardization and modularity. The development of standardized modeling approaches and simulation techniques for SMH (as described in this report) will pave the way for reliable, cost-effective methods for technology evaluation, optimization, and verification.

  8. The influence of climate change on Tanzania's hydropower sustainability

    Science.gov (United States)

    Sperna Weiland, Frederiek; Boehlert, Brent; Meijer, Karen; Schellekens, Jaap; Magnell, Jan-Petter; Helbrink, Jakob; Kassana, Leonard; Liden, Rikard

    2015-04-01

    Economic costs induced by current climate variability are large for Tanzania and may further increase due to future climate change. The Tanzanian National Climate Change Strategy addressed the need for stabilization of hydropower generation and strengthening of water resources management. Increased hydropower generation can contribute to sustainable use of energy resources and stabilization of the national electricity grid. To support Tanzania the World Bank financed this study in which the impact of climate change on the water resources and related hydropower generation capacity of Tanzania is assessed. To this end an ensemble of 78 GCM projections from both the CMIP3 and CMIP5 datasets was bias-corrected and down-scaled to 0.5 degrees resolution following the BCSD technique using the Princeton Global Meteorological Forcing Dataset as a reference. To quantify the hydrological impacts of climate change by 2035 the global hydrological model PCR-GLOBWB was set-up for Tanzania at a resolution of 3 minutes and run with all 78 GCM datasets. From the full set of projections a probable (median) and worst case scenario (95th percentile) were selected based upon (1) the country average Climate Moisture Index and (2) discharge statistics of relevance to hydropower generation. Although precipitation from the Princeton dataset shows deviations from local station measurements and the global hydrological model does not perfectly reproduce local scale hydrographs, the main discharge characteristics and precipitation patterns are represented well. The modeled natural river flows were adjusted for water demand and irrigation within the water resources model RIBASIM (both historical values and future scenarios). Potential hydropower capacity was assessed with the power market simulation model PoMo-C that considers both reservoir inflows obtained from RIBASIM and overall electricity generation costs. Results of the study show that climate change is unlikely to negatively affect the

  9. Loss of European silver eel passing a hydropower station

    DEFF Research Database (Denmark)

    Pedersen, Michael Ingemann; Jepsen, Niels; Aarestrup, Kim

    2012-01-01

    The aim of this study was to assess escapement success of silver eels, Anguilla anguilla (L.), in a lowland river while passing a reservoir and a hydropower station. It was hypothesized that passage success would be lowest at the hydropower station and that survival and migration speed would...... be highest in the free-flowing river section upstream the reservoir. Forty-five female silver eels 56–86 cm in length were tagged with acoustic transmitters and released in November 2006. Their migration was monitored via automatic listening stations (ALS) in various sections of the river, covering a total...

  10. Memorandum of Understanding for Hydropower Two-Year Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-04-01

    On March 24, 2010, the Department of the Army (DOA) through the U.S. Army Corps of Engineers (USACE or Corps), the Department of Energy, and the Department of the Interior signed the Memorandum of Understanding (MOU) for Hydropower. The purpose of the MOU is to “help meet the nation’s needs for reliable, affordable, and environmentally sustainable hydropower by building a long-term working relationship, prioritizing similar goals, and aligning ongoing and future renewable energy development efforts.” This report documents efforts so far.

  11. Balancing hydropower production and river bed incision in operating a run-of-river hydropower scheme along the River Po

    Science.gov (United States)

    Denaro, Simona; Dinh, Quang; Bizzi, Simone; Bernardi, Dario; Pavan, Sara; Castelletti, Andrea; Schippa, Leonardo; Soncini-Sessa, Rodolfo

    2013-04-01

    Water management through dams and reservoirs is worldwide necessary to support key human-related activities ranging from hydropower production to water allocation, and flood risk mitigation. Reservoir operations are commonly planned in order to maximize these objectives. However reservoirs strongly influence river geomorphic processes causing sediment deficit downstream, altering the flow regime, leading, often, to process of river bed incision: for instance the variations of river cross sections over few years can notably affect hydropower production, flood mitigation, water supply strategies and eco-hydrological processes of the freshwater ecosystem. The river Po (a major Italian river) has experienced severe bed incision in the last decades. For this reason infrastructure stability has been negatively affected, and capacity to derive water decreased, navigation, fishing and tourism are suffering economic damages, not to mention the impact on the environment. Our case study analyzes the management of Isola Serafini hydropower plant located on the main Po river course. The plant has a major impact to the geomorphic river processes downstream, affecting sediment supply, connectivity (stopping sediment upstream the dam) and transport capacity (altering the flow regime). Current operation policy aims at maximizing hydropower production neglecting the effects in term of geomorphic processes. A new improved policy should also consider controlling downstream river bed incision. The aim of this research is to find suitable modeling framework to identify an operating policy for Isola Serafini reservoir able to provide an optimal trade-off between these two conflicting objectives: hydropower production and river bed incision downstream. A multi-objective simulation-based optimization framework is adopted. The operating policy is parameterized as a piecewise linear function and the parameters optimized using an interactive response surface approach. Global and local

  12. ESTIMATING HYDROPOWER POTENTIAL OF SMALL RIVERS OF REPUBLIC OF MOLDOVA USING GIS

    Directory of Open Access Journals (Sweden)

    T. CASTRAVEŢ

    2018-06-01

    Full Text Available Estimating hydropower potential of small rivers of Republic of Moldova using GIS, The increasing demand for energy, especially from renewable and sustainable sources, spurs the development of small hydropower plants and encourages investment in new survey studies (Larentis et al., 2010. Preliminary hydropower survey studies usually carry huge uncertainties about the technical, economic and environmental feasibility of the undeveloped potential. This paper presents a methodology for hydropower potential sites assessment. The sequence of procedures to identify hydropower sites is based on remote sensing data and streamflow and rainfall data and was automated within GIS environment.

  13. A hydro-economic model for water level fluctuations: combining limnology with economics for sustainable development of hydropower.

    Science.gov (United States)

    Hirsch, Philipp Emanuel; Schillinger, Sebastian; Weigt, Hannes; Burkhardt-Holm, Patricia

    2014-01-01

    Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reservoirs are influenced by the operator of a hydropower plant, who discharges water through the turbines or stores water in the reservoir, in a fashion that maximizes profit. This rationale governs the seasonal operation scheme and hence determines the water levels within the boundaries of the reservoir's water balance. For progress towards a sustainable development of hydropower, the benefits of this form of electricity generation have to be weighed against the possible detrimental effects of the anthropogenic water level fluctuations. We developed a hydro-economic model that combines an economic optimization function with hydrological estimators of the water balance of a reservoir. Applying this model allowed us to accurately predict water level fluctuations in a reservoir. The hydro-economic model also allowed for scenario calculation of how water levels change with climate change scenarios and with a change in operating scheme of the reservoir (increase in turbine capacity). Further model development will enable the consideration of a variety of additional parameters, such as water withdrawal for irrigation, drinking water supply, or altered energy policies. This advances our ability to sustainably manage water resources that must meet both economic and environmental demands.

  14. A Hydro-Economic Model for Water Level Fluctuations: Combining Limnology with Economics for Sustainable Development of Hydropower

    Science.gov (United States)

    Hirsch, Philipp Emanuel; Schillinger, Sebastian; Weigt, Hannes; Burkhardt-Holm, Patricia

    2014-01-01

    Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reservoirs are influenced by the operator of a hydropower plant, who discharges water through the turbines or stores water in the reservoir, in a fashion that maximizes profit. This rationale governs the seasonal operation scheme and hence determines the water levels within the boundaries of the reservoir's water balance. For progress towards a sustainable development of hydropower, the benefits of this form of electricity generation have to be weighed against the possible detrimental effects of the anthropogenic water level fluctuations. We developed a hydro-economic model that combines an economic optimization function with hydrological estimators of the water balance of a reservoir. Applying this model allowed us to accurately predict water level fluctuations in a reservoir. The hydro-economic model also allowed for scenario calculation of how water levels change with climate change scenarios and with a change in operating scheme of the reservoir (increase in turbine capacity). Further model development will enable the consideration of a variety of additional parameters, such as water withdrawal for irrigation, drinking water supply, or altered energy policies. This advances our ability to sustainably manage water resources that must meet both economic and environmental demands. PMID:25526619

  15. A hydro-economic model for water level fluctuations: combining limnology with economics for sustainable development of hydropower.

    Directory of Open Access Journals (Sweden)

    Philipp Emanuel Hirsch

    Full Text Available Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reservoirs are influenced by the operator of a hydropower plant, who discharges water through the turbines or stores water in the reservoir, in a fashion that maximizes profit. This rationale governs the seasonal operation scheme and hence determines the water levels within the boundaries of the reservoir's water balance. For progress towards a sustainable development of hydropower, the benefits of this form of electricity generation have to be weighed against the possible detrimental effects of the anthropogenic water level fluctuations. We developed a hydro-economic model that combines an economic optimization function with hydrological estimators of the water balance of a reservoir. Applying this model allowed us to accurately predict water level fluctuations in a reservoir. The hydro-economic model also allowed for scenario calculation of how water levels change with climate change scenarios and with a change in operating scheme of the reservoir (increase in turbine capacity. Further model development will enable the consideration of a variety of additional parameters, such as water withdrawal for irrigation, drinking water supply, or altered energy policies. This advances our ability to sustainably manage water resources that must meet both economic and environmental demands.

  16. [Urinary incontinence in non-professional female marathon runners].

    Science.gov (United States)

    Abitteboul, Y; Leonard, F; Mouly, L; Riviere, D; Oustric, S

    2015-09-01

    To determine the prevalence of urinary incontinence within a population of female recreational runners during a marathon. Observational study carried on a marathon from the analysis of questionnaire handed to the participants before the beginning of the marathon. The questionnaire was handed to 800 participants and among them, 517 (64.6%) agreed to fill it. Among the participants, 268 (52.4%) were marathon runners and 243 (47.5%) were relay runners. Mean age of the runners was 41.1 (±9.7), 479 (93.7%) of them were caucasian, mean body mass index was 20,7 (±1.9) kg/m(2) and 173 (34%) were nulliparous. Among responders, 157 (30.7%) runners declared to have urinary incontinence symptoms (any circumstances). Among 157 runners who declared an urinary incontinence, 83 (52,9%) presented with urinary leaks during the running. In half of the cases, these urinary leaks usually arose at the end of race. Urinary incontinence during coughing, sneezing or laughing was reported by 96/517 (18,5%) women. The prevalence of urge urinary incontinence was 63/517 (12%). Concerning the frequency of urinary incontinence, 39/517 (7.5%) women reported at least once weekly. For urinary incontinence bother, scores on the Visual Analogue Scale (VAS 0 to 100) was 1.6 (±1.7). In this series, the prevalence of urinary incontinence was 30.7% within a population of female recreational runners. This rate seems to be similar to the current prevalence in the general population. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  17. Hydropower Optimization Using Artificial Neural Network Surrogate Models of a High-Fidelity Hydrodynamics and Water Quality Model

    Science.gov (United States)

    Shaw, Amelia R.; Smith Sawyer, Heather; LeBoeuf, Eugene J.; McDonald, Mark P.; Hadjerioua, Boualem

    2017-11-01

    Hydropower operations optimization subject to environmental constraints is limited by challenges associated with dimensionality and spatial and temporal resolution. The need for high-fidelity hydrodynamic and water quality models within optimization schemes is driven by improved computational capabilities, increased requirements to meet specific points of compliance with greater resolution, and the need to optimize operations of not just single reservoirs but systems of reservoirs. This study describes an important advancement for computing hourly power generation schemes for a hydropower reservoir using high-fidelity models, surrogate modeling techniques, and optimization methods. The predictive power of the high-fidelity hydrodynamic and water quality model CE-QUAL-W2 is successfully emulated by an artificial neural network, then integrated into a genetic algorithm optimization approach to maximize hydropower generation subject to constraints on dam operations and water quality. This methodology is applied to a multipurpose reservoir near Nashville, Tennessee, USA. The model successfully reproduced high-fidelity reservoir information while enabling 6.8% and 6.6% increases in hydropower production value relative to actual operations for dissolved oxygen (DO) limits of 5 and 6 mg/L, respectively, while witnessing an expected decrease in power generation at more restrictive DO constraints. Exploration of simultaneous temperature and DO constraints revealed capability to address multiple water quality constraints at specified locations. The reduced computational requirements of the new modeling approach demonstrated an ability to provide decision support for reservoir operations scheduling while maintaining high-fidelity hydrodynamic and water quality information as part of the optimization decision support routines.

  18. Short-term hydropower production planning by stochastic programming

    DEFF Research Database (Denmark)

    Fleten, Stein-Erik; Kristoffersen, Trine

    2008-01-01

    Within the framework of multi-stage mixed-integer linear stochastic programming we develop a short-term production plan for a price-taking hydropower plant operating under uncertainty. Current production must comply with the day-ahead commitments of the previous day which makes short...

  19. Future hydropower production in the Lower Zambezi under possible ...

    African Journals Online (AJOL)

    2014-01-15

    Jan 15, 2014 ... considering climate risk in technical design and financial assessment of hydropower projects in the region. Keywords: Zambezi River .... freely available reservoir simulation software developed and maintained by the US ... level at the top of the guide curve elevation, while obeying all further defined rules ...

  20. Requirements and benefits of flow forecasting for improving hydropower generation

    NARCIS (Netherlands)

    Dong, Xiaohua; Vrijling, J.K.; Dohmen-Janssen, Catarine M.; Ruigh, E.; Booij, Martijn J.; Stalenberg, B.; Hulscher, Suzanne J.M.H.; van Gelder, P.H.A.J.M.; Verlaan, M.; Zijderveld, A.; Waarts, P.

    2005-01-01

    This paper presents a methodology to identify the required lead time and accuracy of flow forecasting for improving hydropower generation of a reservoir, by simulating the benefits (in terms of electricity generated) obtained from the forecasting with varying lead times and accuracies. The

  1. modelling of hydropower reservoir variables for energy generation

    African Journals Online (AJOL)

    Osondu

    hydropower is found to be of highest grade of energy (Sambo, 2006). Hydroelectricity comes from the conversion of potential energy of water through turbines and electric generator system. Aliyu and Elegba (1990) indicated that Nigeria is endowed with several potential renewable sources of energy and identified a total of ...

  2. Modeling of Reservoir Inflow for Hydropower Dams Using Artificial ...

    African Journals Online (AJOL)

    The stream flow at the three hydropower reservoirs in Nigeria were modeled using hydro-meteorological parameters and Artificial Neural Network (ANN). The model revealed positive relationship between the observed and the modeled reservoir inflow with values of correlation coefficient of 0.57, 0.84 and 0.92 for Kainji, ...

  3. A feasibility and implementation model of small-scale hydropower ...

    African Journals Online (AJOL)

    Large numbers of households and communities will not be connected to the national electricity grid for the foreseeable future due to high cost of transmission and distribution systems to remote communities and the relatively low electricity demand within rural communities. Small-scale hydropower used to play a very ...

  4. The potential impacts of climate change on hydropower: An ...

    African Journals Online (AJOL)

    Osborne

    Key words: Climate change, discharge rate, hydropower, Malawi, precipitation, temperature. INTRODUCTION. Environmental change, manifested by climate change and variability, is no longer a mythical discourse; the scientific consensus is not only that, human activities have contributed to it significantly, but the change is ...

  5. Systematic high-resolution assessment of global hydropower potential

    NARCIS (Netherlands)

    Hoes, Olivier A C; Meijer, Lourens J J; Van Der Ent, Ruud J.; Van De Giesen, Nick C.

    2017-01-01

    Population growth, increasing energy demand and the depletion of fossil fuel reserves necessitate a search for sustainable alternatives for electricity generation. Hydropower could replace a large part of the contribution of gas and oil to the present energy mix. However, previous high-resolution

  6. The blue water footprint of electricity from hydropower

    NARCIS (Netherlands)

    Mekonnen, Mesfin; Hoekstra, Arjen Ysbert

    2012-01-01

    Hydropower accounts for about 16% of the world's electricity supply. It has been debated whether hydroelectric generation is merely an in-stream water user or whether it also consumes water. In this paper we provide scientific support for the argument that hydroelectric generation is in most cases a

  7. assessment of the hydropower potential of kangimi reservoir

    African Journals Online (AJOL)

    2012-11-03

    Nov 3, 2012 ... Department of Water Resources and Environmental Engineering, Ahmadu Bello University, Zaria, Nigeria. ... Kangimi reservoir to conjunctively meet the water demands for the newly proposed hydropower and designed water supply and ..... basins and leading to environmental degradation and farmland ...

  8. Quadrennial Technology Review 2015: Technology Assessments--Hydropower

    Energy Technology Data Exchange (ETDEWEB)

    Sam Baldwin, Gilbert Bindewald, Austin Brown, Charles Chen, Kerry Cheung, Corrie Clark, Joe Cresko,

    2015-10-07

    Hydropower has provided reliable and flexible base and peaking power generation in the United States for more than a century, contributing on average 10.5% of cumulative U.S. power sector net generation over the past six and one-half decades (1949–2013). It is the nation’s largest source of renewable electricity, with 79 GW of generating assets and 22 GW of pumped-storage assets in service, with hydropower providing half of all U.S. renewable power-sector generation (50% in 2014). In addition to this capacity, the U.S. Department of Energy (DOE) has identified greater than 80 GW of new hydropower resource potential: at least 5 GW from rehabilitation and expansion of existing generating assets, up to 12 GW of potential at existing dams without power facilities, and over 60 GW of potential low-impact new development (LIND) in undeveloped stream reaches. However, despite this growth potential, hydropower capacity and production growth have stalled in recent years, with existing assets even experiencing decreases in capacity and production from lack of sustaining investments in infrastructure and increasing constraints on water use.

  9. Reconnaissance Report for Hydropower Redevelopment at Sault Ste. Marie, Michigan.

    Science.gov (United States)

    1981-01-01

    Chairman Sugarman regarding the feasibility study on hydropower redevelopment at Sault Ste. Marie, Michigan The Commission would appreciate being...United States Government in a timely fashion. Sincerely, David A. LaRoche Secretary United States Section cc: Wingate Lloyd, Department of State F-II-8

  10. Development of Sustainability Assessment Framework in Hydropower sector

    Science.gov (United States)

    Soliha Sahimi, Nur; Turan, Faiz Mohd; Johan, Kartina

    2017-08-01

    Nowadays, Malaysian demand in energy sector was drastically increase due to technological developments. Since, hydropower is one of potential renewable energy source in Malaysia. The largest electricity utility company, Tenaga Nasional Berhad was provide an electricity to more than seven million people via independent suppliers in peninsular Malaysia and Sabah by intended a potential sustainable hydropower system. In order to increasingly the power capacity from current use, 1882 MW to more than 3000 MW by years 2020. In this study, the environmental issues and also the penalty to the responsible company especially on Tenaga Nasional Berhad (TNB) towards their project or business are one of the problems. Other than that, every project or business has to prepare a sustainability statement or sustainability report as vital to Bursa Malaysia Securities Berhad under their listing requirements. Next, the sustainability performance on their project cannot be determined to achieve the key performance indicators (KPI) satisfaction from Government, stakeholder or any responsible agencies. This study presents an exhaustive review of these studies and suggests a direction for future developments. Sustainability Assessment framework or self-assessment is decidedly as a significant framework to assist towards sustainability reporting and to produce a Sustainability index for Hydropower sector using a mathematical model study. The results reveal that, the quantitative measurement from Sustainability Assessment framework to Systematic Sustainability Asssesment tool can be produce. In doing so, it is possible to improve the performance of the project especially in hydropower planner.

  11. False Shades of Green: The Case of Brazilian Amazonian Hydropower

    Directory of Open Access Journals (Sweden)

    James Randall Kahn

    2014-09-01

    Full Text Available The Federal Government of Brazil has ambitious plans to build a system of 58 additional hydroelectric dams in the Brazilian Amazon, with Hundreds of additional dams planned for other countries in the watershed. Although hydropower is often billed as clean energy, we argue that the environmental impacts of this project are likely to be large, and will result in substantial loss of biodiversity, as well as changes in the flows of ecological services. Moreover, the projects will generate significant greenhouse gas emissions from deforestation and decay of organic matter in the reservoirs. These emissions are equivalent to the five years of emissions that would be generated by gas powered plants of equivalent capacity. In addition, we examine the economic benefits of the hydropower in comparison to new alternatives, such as photovoltaic energy and wind power. We find that current costs of hydropower exceed alternatives, and the costs of costs of these alternatives are likely to fall substantially below those of hydropower, while the environmental damages from the dams will be extensive and irreversible.

  12. Estimated cumulative sediment trapping in future hydropower reservoirs in Africa

    Science.gov (United States)

    Lucía, Ana; Berlekamp, Jürgen; Zarfl, Christiane

    2017-04-01

    Despite a rapid economic development in Sub-Saharan Africa, almost 70% of the human population in this area remain disconnected from electricity access (International Energy Agency 2011). Mitigating climate change and a search for renewable, "climate neutral" electricity resources are additional reasons why Africa will be one key centre for future hydropower dam building, with only 8% of the technically feasible hydropower potential actually exploited. About 300 major hydropower dams with a total capacity of 140 GW are currently under construction (11.4%) or planned (88.6%) (Zarfl et al. 2015). Despite the benefits of hydropower dams, fragmentation of the rivers changes the natural flow, temperature and sediment regime. This has consequences for a high number of people that directly depend on the primary sector linked to rivers and floodplains. But sediment trapping in the reservoir also affects dam operation and decreases its life span. Thus, the objective of this work is to quantify the dimension of sediment trapping by future hydropower dams in African river basins. Soil erosion is described with the universal soil loss equation (Wischmeier & Smith 1978) and combined with the connectivity index (Cavalli et al. 2013) to estimate the amount of eroded soil that reaches the fluvial network and finally ends up in the existing (Lehner et al. 2011) and future reservoirs (Zarfl et al. 2015) per year. Different scenarios assuming parameter values from the literature are developed to include model uncertainty. Estimations for existing dams will be compared with literature data to evaluate the applied estimation method and scenario assumptions. Based on estimations for the reservoir volume of the future dams we calculated the potential time-laps of the future reservoirs due to soil erosion and depending on their planned location. This approach could support sustainable decision making for the location of future hydropower dams. References Cavalli, M., Trevisani, S., Comiti

  13. Applications of the Rapid Prototyping Technology to Manufacture the Pelton Runners

    Directory of Open Access Journals (Sweden)

    Dorian Nedelcu

    2013-05-01

    Full Text Available The paper presents an application of the Rapid Prototyping technology using Objet Desktop 3D Printer to manufacture two Pelton runners that are destined for experimental measurements on a Pelton microturbine. The runners are different by bucket’s number and the bucket’s geometry of the second runner is similar with those of the first runner, but scaled in all directions with the bucket’s numbers ratio.

  14. Comparison of foot strike patterns of barefoot and minimally shod runners in a recreational road race

    OpenAIRE

    Peter Larson

    2014-01-01

    Background: Previous studies of foot strike patterns of distance runners in road races have typically found that the overwhelming majority of shod runners initially contact the ground on the rearfoot. However, none of these studies has attempted to quantify foot strike patterns of barefoot or minimally shod runners. This study classifies foot strike patterns of barefoot and minimally shod runners in a recreational road race. Methods: High-speed video footage was obtained of 169 barefoot an...

  15. A procedure for assessing climate change impacts on hydropower

    Energy Technology Data Exchange (ETDEWEB)

    Hamududu, B.; Jjunju, E.; Killingtveit, Aa.; Alfredsen, K.

    2010-07-01

    Full text: Ever since climate change was highlighted as an important issue in water related projects, various procedures have been used by different researchers to gain indications of likely impact of climate change on hydropower. Though all methods give results, comparisons of these results is not ideal and may be difficult due to large differences in methods used. This paper is an attempt to propose an ideal procedure or process of estimating the impact of climate change on hydropower production in a basin. The paper describes where to begin, what future climate change projections are necessary, and where to get such data. It also shows highlights various techniques that are available and could be applied to climate projections in order to down scale the large scale projections from global climate models to site or basin climate. Another technique that has been applied is the delta approach or perturbation methods that transfer changes in meteorological variables between the control and the scenario simulations from the regional climate model to a database of observed meteorological data. Further it highlights various ways of transforming basin climate variables that can be used in hydrological modeling to produce runoff series. The paper also discusses applicability of hydrological modeling strategies for climate predictions in relation to stationarity in models and how this will influence climate predictions. The runoff is the input into hydropower systems and hydropower simulations to get the desired hydropower production in the future. In all these steps, different approaches for processing are highlighted. The paper ends with a section on different sources of uncertainties in climate projections. Finally some concluding remarks are given on the reliability of the results from various methodologies. A case study on Zambezi River basin is given towards the end illustrating the differences resulting from different methodologies. (Author)

  16. Regulatory approaches for addressing dissolved oxygen concerns at hydropower facilities

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Mark J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cada, Glenn F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sale, Michael J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Eddlemon, Gerald K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2003-03-01

    Low dissolved oxygen (DO) concentrations are a common water quality problem downstream of hydropower facilities. At some facilities, structural improvements (e.g. installation of weir dams or aerating turbines) or operational changes (e.g., spilling water over the dam) can be made to improve DO levels. In other cases, structural and operational approaches are too costly for the project to implement or are likely to be of limited effectiveness. Despite improvements in overall water quality below dams in recent years, many hydropower projects are unable to meet state water quality standards for DO. Regulatory agencies in the U.S. are considering or implementing dramatic changes in their approach to protecting the quality of the Nation’s waters. New policies and initiatives have emphasized flexibility, increased collaboration and shared responsibility among all parties, and market-based, economic incentives. The use of new regulatory approaches may now be a viable option for addressing the DO problem at some hydropower facilities. This report summarizes some of the regulatory-related options available to hydropower projects, including negotiation of site-specific water quality criteria, use of biological monitoring, watershed-based strategies for the management of water quality, and watershed-based trading. Key decision points center on the health of the local biological communities and whether there are contributing impacts (i.e., other sources of low DO effluents) in the watershed. If the biological communities downstream of the hydropower project are healthy, negotiation for site-specific water quality standards or biocriteria (discharge performance criteria based on characteristics of the aquatic biota) might be pursued. If there are other effluent dischargers in the watershed that contribute to low DO problems, watershed-scale strategies and effluent trading may be effective. This report examines the value of regulatory approaches by reviewing their use in

  17. The blue water footprint of electricity from hydropower

    Directory of Open Access Journals (Sweden)

    M. M. Mekonnen

    2012-01-01

    Full Text Available Hydropower accounts for about 16% of the world's electricity supply. It has been debated whether hydroelectric generation is merely an in-stream water user or whether it also consumes water. In this paper we provide scientific support for the argument that hydroelectric generation is in most cases a significant water consumer. The study assesses the blue water footprint of hydroelectricity – the water evaporated from manmade reservoirs to produce electric energy – for 35 selected sites. The aggregated blue water footprint of the selected hydropower plants is 90 Gm3 yr−1, which is equivalent to 10% of the blue water footprint of global crop production in the year 2000. The total blue water footprint of hydroelectric generation in the world must be considerably larger if one considers the fact that this study covers only 8% of the global installed hydroelectric capacity. Hydroelectric generation is thus a significant water consumer. The average water footprint of the selected hydropower plants is 68 m3 GJ−1. Great differences in water footprint among hydropower plants exist, due to differences in climate in the places where the plants are situated, but more importantly as a result of large differences in the area flooded per unit of installed hydroelectric capacity. We recommend that water footprint assessment is added as a component in evaluations of newly proposed hydropower plants as well as in the evaluation of existing hydroelectric dams, so that the consequences of the water footprint of hydroelectric generation on downstream environmental flows and other water users can be evaluated.

  18. Sulfur status in long distance runners

    Science.gov (United States)

    Kovacs, L.; Zamboni, C.; Lourenço, T.; Macedo, D.

    2015-07-01

    In sports medicine, sulfur plays an important role and its deficiency can cause muscle injury affecting the performance of the athletes. However, its evaluation is unusual in conventional clinical practice. In this study the sulfur levels were determined in Brazilian amateur athlete's blood using Neutron Activation Analyses (NAA) technique. Twenty six male amateur runners, age 18 to 36 years, participated of this study. The athletes had a balanced diet, without multivitamin/mineral supplements. The blood collection was performed at LABEX (Laboratoriode Bioquimica do Exercicio, UNICAMP-SP) and the samples were irradiated for 300 seconds in a pneumatic station in the nuclear reactor (IEA-R1, 3-4.5MW, pool type) at IPEN/CNEN-SP. The results were compared with the control group (subjects of same age but not involved with physical activities) and showed that the sulfur concentration was 44% higher in amateurs athletes than control group. These data can be considered for preparation of balanced diet, as well as contributing for proposing new protocols of clinical evaluation.

  19. Sex Differences in Limb and Joint Stiffness in Recreational Runners

    Directory of Open Access Journals (Sweden)

    Sinclair Jonathan

    2015-09-01

    Full Text Available Purpose. Female runners are known to be at greater risk from chronic running injuries than age-matched males, although the exact mechanisms are often poorly understood. The aim of the current investigation was to determine if female recreational runners exhibit distinct limb and joint stiffness characteristics in relation to their male counterparts. Methods. Fourteen male and fourteen female runners ran over a force platform at 4.0 m · s-1. Lower limb kinematics were collected using an eight-camera optoelectric motion capture system operating at 250 Hz. Measures of limb and joint stiffness were calculated as a function of limb length and joint moments divided by the extent of limb and joint excursion. All stiffness and joint moment parameters were normalized to body mass. Sex differences in normalized limb and knee and ankle joint stiffness were examined statistically using independent samples t tests. Results. The results indicate that normalized limb (male = 0.18 ± 0.07, female = 0.37 ± 0.10 kN · kg · m-1 and knee stiffness (male = 5.59 ± 2.02, female = 7.34 ± 1.78 Nm · kg · rad-1 were significantly greater in female runners. Conclusions. On the basis that normalized knee and limb stiffness were shown to be significantly greater in female runners, the findings from the current investigation may provide further insight into the aetiology of the distinct injury patterns observed between sexes.

  20. Left ventricular function in endurance runners during exercise.

    Science.gov (United States)

    Jensen-Urstad, M; Bouvier, F; Nejat, M; Saltin, B; Brodin, L A

    1998-10-01

    Left ventricular function in elite runners and controls was compared by means of nuclear angiocardiography. Fifteen middle- or long-distance runners and a control group of 10 sedentary to moderately physically active subjects were studied at rest and during semi-sitting incremental exercise. Ejection fraction was higher in the runners than the controls both at rest and during exercise. At the transition from rest to exercise left ventricular end-diastolic volume initially increased similarly in runners and controls by an average of 14 and 12%, respectively, with an increase in stroke volume by approximately 25 and 23%. The parallel increase in stroke volume and left ventricular end-diastolic volume could at least partly be because of the Frank-Starling mechanism. With increasing workloads, left ventricular end-diastolic volume and ejection fraction remained fairly constant, resulting in an unchanged stroke volume from the lowest to the highest exercise intensity. This was in the runners accomplished by a 41% increase in peak filling rate and a 38% increase in peak emptying rate with similar changes observed in the controls. This has to be due to increased myocardial contractility paralleling the systolic shortening with increasing heart rate. We conclude that endurance-trained athletes have a better systolic function expressed as higher ejection fraction both at rest and during exercise than untrained subjects reflecting an enhanced myocardial contractility contributing to the maintenance of a large stroke volume during exercise. The regulatory mechanisms however, appear to be similar for athletes and healthy controls.

  1. Hip Biomechanics Are Altered in Male Runners with Achilles Tendinopathy.

    Science.gov (United States)

    Creaby, Mark W; Honeywill, Conor; Franettovich Smith, Melinda M; Schache, Anthony G; Crossley, Kay M

    2017-03-01

    Achilles tendinopathy (AT) is a prevalent injury in running sports. Understanding the biomechanical factors associated with AT will assist in its management and prevention. The purpose of this study was to compare hip and ankle kinematics and kinetics in runners with and without AT. Fourteen male runners with AT and 11 healthy male runners (CTRL) ran over ground while lower-limb joint motion and ground reaction force data were synchronously captured. Hip and ankle joint angles, moments, and impulses in all three planes (sagittal, transverse, and frontal) were extracted for analysis. Independent t-tests were used to compare the differences between the AT and the CTRL groups for the biomechanical variables of interest. After Bonferroni adjustment, an alpha level of 0.0026 was set for all analyses. The AT group exhibited an increased peak hip external rotation moment (P = 0.001), hip external rotation impulse (P biomechanics were observed. This study presents preliminary evidence indicating that male runners with AT display altered hip biomechanics with respect to their healthy counterparts. Because of the retrospective design of the study, it is unknown whether these alterations are a predisposing factor for the disorder, a result of the condition, or a combination of both. The results of this study suggest that optimizing hip joint function should be considered in the rehabilitation of runners with AT.

  2. Running economy assessment within cardiopulmonary exercise testing for recreational runners.

    Science.gov (United States)

    Engeroff, Tobias; Bernardi, Andreas; Vogt, Lutz; Banzer, Winfried

    2016-03-01

    The aim of this study was to evaluate the influence of running economy (RE) on running performance within recreational runners of different maximal aerobic capacity, and the feasibility of RE assessment within routine cardiopulmonary exercise testing (CPET). Sixty-eight recreational runners (m: 49, f: 19; age: 21-54) completed a graded exercise test (GXT) until exhaustion. Maximal oxygen uptake and respiratory compensation point were obtained via CPET. RE was calculated as relative oxygen uptake per covered distance (mL/kg/km) one step below respiratory compensation point (RCP). Subjects were grouped for RE via median split and categorized into one of six fitness levels (Very Poor, Poor, Fair, Good, Excellent, Superior) (ACSM 2010). Irrespective of fitness levels, recreational runners with a more energy efficient movement (RErunners within VO2max categories Good and Superior differed significantly (Precreational distance runners within a broad range of maximal aerobic capacity. Complementing routine CPET with RE assessment at physiological threshold intensities and ACSM based categorization seems feasible to delineate the impact of movement efficiency and aerobic fitness on performance in recreational runners.

  3. Blade Runner : entre o passado e o futuro Blade Runner : betwen past and future

    Directory of Open Access Journals (Sweden)

    Paulo Menezes

    1999-05-01

    Full Text Available Blade Runner é muito mais do que um filme sobre o futuro. A versão remontada por Ridley Scott, em 1993, remete a dimensões que a versão que vimos inicialmente nos cinemas dissolvia. Problematiza de maneira contundente as relações entre passado, presente e futuro, questionando a concepção de tempo linear e as relações do homem com o seu próprio tempo e a sua própria história. Aqui, a temporalidade do que poderia ser chamado de propriamente humano constitui-se nas relações que o homem trava com a sua própria memória buscando, a partir disso, a comprovação de sua existência enquanto ser e, portanto, enquanto dono de seu passado e de sua própria vida.Blade Runner is not only a film about the future. The Ridley Scott's version, remaked in 1993, show us dimensions that the first one had dissolved. Relations concerning past, present and future are the emphasis now, in order to question the linear conception of time and the relations between men and his own time and history. The temporality of the so called specific human kind emerges from the search towards his own memory which can prove his existence as human being and thus as master of his past and live.

  4. Eco-runner team Delft; the most fuel efficient vehicle in the world

    NARCIS (Netherlands)

    Rijks, F.

    2014-01-01

    The slogan, ‘Eco-Runner: the most fuel efficient vehicle in the world’ of the Eco-Runner Team Delft says it all: designing and building the most fuel efficient vehicle in the world. The Eco-Runner Team is a ‘D:DREAM Team’ where students from various faculties work together to design and build

  5. The Influence of Matching Populations on Kinematic and Kinetic Variables in Runners with Iliotibial Band Syndrome

    Science.gov (United States)

    Grau, Stefan; Maiwald, Christian; Krauss, Inga; Axmann, Detlef; Horstmann, Thomas

    2008-01-01

    The purpose of this study was to assess how participant matching influences biomechanical variables when comparing healthy runners and runners with iliotibial band syndrome (ITBS). We examined 52 healthy runners (CO) and 18 with ITBS, using three-dimensional kinematics and pressure distribution. The study population was matched in three ways and…

  6. It's a Matter of Mind! Cognitive Functioning Predicts the Athletic Performance in Ultra-Marathon Runners.

    Directory of Open Access Journals (Sweden)

    Giorgia Cona

    Full Text Available The present study was aimed at exploring the influence of cognitive processes on performance in ultra-marathon runners, providing an overview of the cognitive aspects that characterize outstanding runners. Thirty runners were administered a battery of computerized tests right before their participation in an ultra-marathon. Then, they were split according to the race rank into two groups (i.e., faster runners and slower runners and their cognitive performance was compared. Faster runners outperformed slower runners in trials requiring motor inhibition and were more effective at performing two tasks together, successfully suppressing the activation of the information for one of the tasks when was not relevant. Furthermore, slower runners took longer to remember to execute pre-defined actions associated with emotional stimuli when such stimuli were presented. These findings suggest that cognitive factors play a key role in running an ultra-marathon. Indeed, if compared with slower runners, faster runners seem to have a better inhibitory control, showing superior ability not only to inhibit motor response but also to suppress processing of irrelevant information. Their cognitive performance also appears to be less influenced by emotional stimuli. This research opens new directions towards understanding which kinds of cognitive and emotional factors can discriminate talented runners from less outstanding runners.

  7. Middle age male distance runners: physiological and psychological profiles.

    Science.gov (United States)

    Maresh, C M; Sheckley, B G; Allen, G J; Camaione, D N; Sinatra, S T

    1991-09-01

    This study investigated 4 research questions addressing exercise capabilities and psychological characteristics of middle-age (30 to 50 years) male runners. Subjects provided an extensive running history, completed the Multidimensional Anger Inventory, completed the Myers-Briggs Type Indicator, and performed a treadmill running test to volitional exhaustion. Another aspect of the study compared anticipatory and posttest reactions to the treadmill test experience to actual test results. The findings suggest that these runners have common personality profiles, that long-term involvement in running and training is associated with a positive sense of self, and that lifelong aerobic exercise is associated with high cardiovascular fitness. Although the research design does not permit causal or predictive conclusions, the study provides valuable additional baseline information for physicians and fitness professionals who serve middle aged male runners.

  8. Echocardiographic left ventricular masses in distance runners and weight lifters

    Science.gov (United States)

    Longhurst, J. C.; Gonyea, W. J.; Mitchell, J. H.; Kelly, A. R.

    1980-01-01

    The relationships of different forms of exercise training to left ventricular mass and body mass are investigated by echocardiographic studies of weight lifters, long-distance runners, and comparatively sized untrained control subjects. Left ventricular mass determinations by the Penn convention reveal increased absolute left ventricular masses in long-distance runners and competitive weight lifters with respect to controls matched for age, body weight, and body surface area, and a significant correlation between ventricular mass and lean body mass. When normalized to lean body mass, the ventricular masses of distance runners are found to be significantly higher than those of the other groups, suggesting that dynamic training elevates left ventricular mass compared to static training and no training, while static training increases ventricular mass only to the extent that lean body mass is increased.

  9. Dietary supplement usage and motivation in Brazilian road runners.

    Science.gov (United States)

    Salgado, José Vítor Vieira; Lollo, Pablo Christiano Barboza; Amaya-Farfan, Jaime; Chacon-Mikahil, Mara PatríciaTraina

    2014-01-01

    The consumption of dietary supplements is highest among athletes and it can represent potential a health risk for consumers. The aim of this study was to determine the prevalence of consumption of dietary supplements by road runners. We interviewed 817 volunteers from four road races in the Brazilian running calendar. The sample consisted of 671 male and 146 female runners with a mean age of 37.9 ± 12.4 years. Of the sample, 28.33% reported having used some type of dietary supplement. The main motivation for this consumption is to increase in stamina and improve performance. The probability of consuming dietary supplements increased 4.67 times when the runners were guided by coaches. The consumption of supplements was strongly correlated (r = 0.97) with weekly running distance, and also highly correlated (r = 0.86) with the number of years the sport had been practiced. The longer the runner had practiced the sport, the higher the training volume and the greater the intake of supplements. The five most frequently cited reasons for consumption were: energy enhancement (29.5%), performance improvement (17.1%), increased level of endurance (10.3%), nutrient replacement (11.1%), and avoidance of fatigue (10.3%). About 30% of the consumers declared more than one reason for taking dietary supplements. The most consumed supplements were: carbohydrates (52.17%), vitamins (28.70%), and proteins (13.48%). Supplement consumption by road runners in Brazil appeared to be guided by the energy boosting properties of the supplement, the influence of coaches, and the experience of the user. The amount of supplement intake seemed to be lower among road runners than for athletes of other sports. We recommend that coaches and nutritionists emphasise that a balanced diet can meet the needs of physically active people.

  10. Hydro-abrasive erosion on coated Pelton runners: Partial calibration of the IEC model based on measurements in HPP Fieschertal

    Science.gov (United States)

    Felix, D.; Abgottspon, A.; Albayrak, I.; Boes, R. M.

    2016-11-01

    At medium- and high-head hydropower plants (HPPs) on sediment-laden rivers, hydro-abrasive erosion on hydraulic turbines is a major economic issue. For optimization of such HPPs, there is an interest in equations to predict erosion depths. Such a semi-empirical equation suitable for engineering practice is proposed in the relevant guideline of the International Electrotechnical Commission (IEC 62364). However, for Pelton turbines no numerical values of the model's calibration parameters have been available yet. In the scope of a research project at the high-head HPP Fieschertal, Switzerland, the particle load and the erosion on the buckets of two hard-coated 32 MW-Pelton runners have been measured since 2012. Based on three years of field data, the numerical values of a group of calibration parameters of the IEC erosion model were determined for five application cases: (i) reduction of splitter height, (ii) increase of splitter width and (iii) increase of cut-out depth due to erosion of mainly base material, as well as erosion of coating on (iv) the splitter crests and (v) inside the buckets. Further laboratory and field investigations are recommended to quantify the effects of individual parameters as well as to improve, generalize and validate erosion models for uncoated and coated Pelton turbines.

  11. Projected impacts of climate change on hydropower potential in China

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xingcai; Tang, Qiuhong; Voisin, Nathalie; Cui, Huijuan

    2016-01-01

    Hydropower is an important renewable energy source in China, but it is sensitive to climate change, because the changing climate may alter hydrological conditions (e.g., river flow and reservoir storage). Future changes and associated uncertainties in China's gross hydropower potential (GHP) and developed hydropower potential (DHP) are projected using simulations from eight global hydrological models (GHMs), including a large-scale reservoir regulation model, forced by five general circulation models (GCMs) with climate data under two representative concentration pathways (RCP2.6 and RCP8.5). Results show that the estimation of the present GHP of China is comparable to other studies; overall, the annual GHP is projected to change by −1.7 to 2 % in the near future (2020–2050) and increase by 3 to 6 % in the late 21st century (2070–2099). The annual DHP is projected to change by −2.2 to −5.4 % (0.7–1.7 % of the total installed hydropower capacity (IHC)) and −1.3 to −4 % (0.4–1.3 % of total IHC) for 2020–2050 and 2070–2099, respectively. Regional variations emerge: GHP will increase in northern China but decrease in southern China – mostly in south central China and eastern China – where numerous reservoirs and large IHCs currently are located. The area with the highest GHP in southwest China will have more GHP, while DHP will reduce in the regions with high IHC (e.g., Sichuan and Hubei) in the future. The largest decrease in DHP (in %) will occur in autumn or winter, when streamflow is relatively low and water use is competitive. Large ranges in hydropower estimates across GHMs and GCMs highlight the necessity of using multimodel assessments under climate change conditions. This study prompts the consideration of climate change in planning for hydropower development and operations in China, to be further combined with a socioeconomic analysis for strategic expansion.

  12. Normative values of eccentric hip abduction strength in novice runners

    DEFF Research Database (Denmark)

    Jørgensen, Daniel Ramskov; Pedersen, Mette Broen; Kastrup, Kristrian

    2014-01-01

    normative values of maximal eccentric hip abduction strength in novice runners. METHODS: Novice healthy runners (n = 831) were recruited through advertisements at a hospital and a university. Maximal eccentric hip abduction strength was measured with a hand-held dynamometer. The demographic variables...... associated with maximal eccentric hip abduction strength from a univariate analysis were included in a multivariate linear regression model. Based on the results from the regression model, a regression equation for normative hip abduction strength is presented. RESULTS: A SIGNIFICANT DIFFERENCE IN MAXIMAL...

  13. Diet intake and endurance performance in Kenyan runners

    DEFF Research Database (Denmark)

    Christensen, Dirk Lund

    2004-01-01

    in carbohydrate and total protein, but low to borderline in a few essential amino acids. The timing of diet intake – immediately after training sessions – is optimal for skeletal muscle glycogen resynthesis that is enhanced without the help of insulin up to 60 min after cessation of exercise. Whether the total...... energy intake of the Kenyan runners is adequate is debatable. However, chronic undernutrition is not possible for athletes who engage in daily high-quality and -quantity physical exercise throughout most of the year. It is suggested that Kenyan runners participate in well-controlled, laboratory studies...

  14. Pre- and postmarathon training habits of nonelite runners

    Directory of Open Access Journals (Sweden)

    Angela M Voight

    2011-03-01

    Full Text Available Angela M Voight1, William O Roberts1, Scott Lunos2, Lisa S Chow31Department of Family Medicine and Community Health; 2Biostatistical Design and Analysis Center, Clinical and Translational Science Institute; 3Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, University of Minnesota, Minneapolis, MN, USABackground: Despite the increasing popularity of marathons, little research has examined the training habits of nonelite marathon runners. Given that nonelite runners, particularly those with a competitive motive, have a higher risk for injury than experienced elite runners, it is important for physicians to understand the training program and features that might distinguish running performance and injury rates in this population.Hypothesis: We hypothesized that nonelite runners who qualify for the Boston Marathon (“qualifiers” would have higher running volumes, more running sessions per week, lower injury rates, and lower body mass index (BMI than nonqualifying runners.Study design: A cross-sectional Web-based survey of runners (convenience sample at 1 month (n = 50 and 6 months (n = 41 after participation in the 2008 Twin Cities Marathon (TCM that acquired data on anthropometric measures, demographic data, finishing time, premarathon/current training program, and self-reported injury.Results: Thirteen of 50 initial survey respondents were classified as a “qualifier” based on their finishing time. Mean BMI was significantly lower in the qualifiers at 1 month (22.0 versus 23.9 kg/m2, P = 0.0267 but not 6 months postmarathon. There were no significant differences in training volume (running frequency, run length, or cross-training volume or injury rates between qualifiers and nonqualifiers. Prior to the 2008 TCM, 54% of runners included cross-training in their exercise program, which increased significantly to 74% 1 month postmarathon (P = 0.0039 and 71% 6 months postmarathon (P = 0.0325. There was no association

  15. Blade Runner, pós-modernidade e totalitarismo

    Directory of Open Access Journals (Sweden)

    Aldo Dinucci

    2013-10-01

    Full Text Available Em 2012 tivemos o trigésimo aniversário tanto do lançamento do filme Blade Runner, do diretor Ridley Scott, quanto da morte do escritor de ficção científica Philip K. Dick, cujo livro intitulado Do Androids Dream of Electric Sheep? (Sonham os Androides com carneiros elétricos? inspirou a película. Nas páginas seguintes, analisarei alguns aspectos do filme Blade Runner, mostrando que se pode ver nele uma metáfora da pós-modernidade e do totalitarismo que acompanha esta última.

  16. Effects of menstrual phase and amenorrhea on exercise performance in runners.

    Science.gov (United States)

    De Souza, M J; Maguire, M S; Rubin, K R; Maresh, C M

    1990-10-01

    There are few well controlled studies in terms of subject selection, menstrual classification, and exercise protocol that have examined both maximal and submaximal exercise responses during different phases of the menstrual cycle in eumenorrheic runners and compared these runners to amenorrheic runners. Thus, the purpose of this study was to measure selected physiological and metabolic responses to maximal and submaximal exercise during two phases of the menstrual cycle in eumenorrheic runners and amenorrheic runners. Eight eumenorrheic runners (29.0 +/- 4.2 yr) and eight amenorrheic runners (24.5 +/- 5.7 yr) matched for physical, gynecological, and training characteristics were studied. The eumenorrheic runners performed one maximal and one submaximal (40 min at 80% VO2max) treadmill run during both the early follicular (days 2-4) and midluteal (6-8 d from LH surge) phases. The amenorrheic runners performed one maximal and one submaximal (40 min at 80% VO2max) treadmill run. Cycle phases were documented by urinary luteinizing hormone and progesterone assays and by plasma estradiol and progesterone assays. No differences were observed in oxygen uptake, minute ventilation, heart rate, respiratory exchange ratio, rating of perceived exertion, time to fatigue (maximal), and plasma lactate (following the maximal and submaximal exercise tests) between the follicular and luteal phases in the eumenorrheic runners and the amenorrheic runners. We conclude that neither menstrual phase (follicular vs luteal) nor menstrual status (eumenorrheic vs amenorrheic) alters or limits exercise performance in female athletes.

  17. Achilles tendinopathy in amateur runners: role of adiposity (Tendinopathies and obesity).

    Science.gov (United States)

    Abate, Michele; Oliva, Francesco; Schiavone, Cosima; Salini, Vincenzo

    2012-01-01

    Obesity is an important risk factor for Achilles tendinopathy, and running is usually carried out to reduce excess body weight. Aim of this study was to evaluate the prevalence of Achilles tendinopathy in young over-weight amateur runners. MALE RUNNERS AND NON RUNNERS WERE RECRUITED AND, IN EACH CATEGORY, DIVIDED IN TWO GROUPS: normal weight, and overweight. Data about Achilles tendon thickness, vascularisation and structural abnormalities were collected using a Power Doppler Ultrasonography device. Achilles tendon thickness was greater in both normal weight or overweight runners, but the difference was significant only in normal weight subjects. In non - runners, thickness was significantly higher only in over-weight subjects. Sonographic abnormalities were significantly prevalent in overweight runners. Running is associated to a physiologic hypertrophy of Achilles tendon in normal weight subjects. Overweight runners may precociously develop tendon abnormalities, due to the increased stress and the unfavourable milieu of repair.

  18. The Grossmatt hydro-power station; Wasserkraftwerk Grossmatt. Konzessionsprojekt

    Energy Technology Data Exchange (ETDEWEB)

    Hintermann, M.

    2006-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) presents the project for a small hydropower station on the Birs river in north-western Switzerland. The report reviews the history of the project, in which a new 385 kW-hydro-power station at the site of an earlier installation is foreseen. Details are presented on the investigations made and on the co-ordination with the owners of the hydro-power station situated up-river, the local power utility and the local authorities. Also, the requirements placed on the project by the fishing authorities are quoted and the solution foreseen is described. Also discussed are the requirements placed on the project by legislation on environmental impact and flood protection. Figures on electrical energy production and building costs are presented.

  19. PREDICTION OF TOTAL DISSOLVED GAS EXCHANGE AT HYDROPOWER DAMS

    Energy Technology Data Exchange (ETDEWEB)

    Hadjerioua, Boualem [ORNL; Pasha, MD Fayzul K [ORNL; Stewart, Kevin M [ORNL; Bender, Merlynn [Bureau of Reclamation; Schneider, Michael L. [U.S. Army Corps of Engineers

    2012-07-01

    Total dissolved gas (TDG) supersaturation in waters released at hydropower dams can cause gas bubble trauma in fisheries resulting in physical injuries and eyeball protrusion that can lead to mortality. Elevated TDG pressures in hydropower releases are generally caused by the entrainment of air in spillway releases and the subsequent exchange of atmospheric gasses into solution during passage through the stilling basin. The network of dams throughout the Columbia River Basin (CRB) are managed for irrigation, hydropower production, flood control, navigation, and fish passage that frequently result in both voluntary and involuntary spillway releases. These dam operations are constrained by state and federal water quality standards for TDG saturation which balance the benefits of spillway operations designed for Endangered Species Act (ESA)-listed fisheries versus the degradation to water quality as defined by TDG saturation. In the 1970s, the United States Environmental Protection Agency (USEPA), under the federal Clean Water Act (Section 303(d)), established a criterion not to exceed the TDG saturation level of 110% in order to protect freshwater and marine aquatic life. The states of Washington and Oregon have adopted special water quality standards for TDG saturation in the tailrace and forebays of hydropower facilities on the Columbia and Snake Rivers where spillway operations support fish passage objectives. The physical processes that affect TDG exchange at hydropower facilities have been studied throughout the CRB in site-specific studies and routine water quality monitoring programs. These data have been used to quantify the relationship between project operations, structural properties, and TDG exchange. These data have also been used to develop predictive models of TDG exchange to support real-time TDG management decisions. These empirically based predictive models have been developed for specific projects and account for both the fate of spillway and

  20. Asynchrony of wind and hydropower resources in Australia.

    Science.gov (United States)

    Gunturu, Udaya Bhaskar; Hallgren, Willow

    2017-08-18

    Wind and hydropower together constitute nearly 80% of the renewable capacity in Australia and their resources are collocated. We show that wind and hydro generation capacity factors covary negatively at the interannual time scales. Thus, the technology diversity mitigates the variability of renewable power generation at the interannual scales. The asynchrony of wind and hydropower resources is explained by the differential impact of the two modes of the El Ni˜no Southern Oscillation - canonical and Modoki - on the wind and hydro resources. Also, the Modoki El Ni˜no and the Modoki La Ni˜na phases have greater impact. The seasonal impact patterns corroborate these results. As the proportion of wind power increases in Australia's energy mix, this negative covariation has implications for storage capacity of excess wind generation at short time scales and for generation system adequacy at the longer time scales.

  1. Asynchrony of wind and hydropower resources in Australia

    KAUST Repository

    Gunturu, Udaya

    2017-08-14

    Wind and hydropower together constitute nearly 80% of the renewable capacity in Australia and their resources are collocated. We show that wind and hydro generation capacity factors covary negatively at the interannual time scales. Thus, the technology diversity mitigates the variability of renewable power generation at the interannual scales. The asynchrony of wind and hydropower resources is explained by the differential impact of the two modes of the El Ni˜no Southern Oscillation – canonical and Modoki – on the wind and hydro resources. Also, the Modoki El Ni˜no and the Modoki La Ni˜na phases have greater impact. The seasonal impact patterns corroborate these results. As the proportion of wind power increases in Australia’s energy mix, this negative covariation has implications for storage capacity of excess wind generation at short time scales and for generation system adequacy at the longer time scales.

  2. Small hydropower station in Lavin - Preliminary study; Kleinwasserkraftwerk Lavin - Vorstudie

    Energy Technology Data Exchange (ETDEWEB)

    Merz, F.

    2008-05-15

    This illustrated final report for the Swiss Federal Office of Energy (SFOE) presents the results of a preliminary study regarding a proposed small hydropower installation on the alpine river Lavinuoz in Lavin, Switzerland. The geographical situation with mountains and glaciers in the catchment area of the proposed hydropower installation is discussed as are the appropriate water catchment installations. Possible dangers caused by avalanches and rock fall are examined. The power to be produced - 5,500,000 kWh/y - by the turbine which is nominally rated at 1350 kW is discussed, as are estimates of production costs. Figures on the investments required and the economic feasibility of the project are discussed, as are environmental factors that are to be taken into account.

  3. Environmental certification for small hydropower plants; Umweltzertifizierung Kleinwasserkraftwerke

    Energy Technology Data Exchange (ETDEWEB)

    Truffer, B.; Meier, W.; Vollenweider, S. [Eidgenoessische Anstalt fuer Wasserversorgung, Abwasserreinigung und Gewaesserschutz (EAWAG), Kastanienbaum (Switzerland); Seiler, B.; Dettli, R. [Econcept AG, Zuerich (Switzerland)

    2001-07-01

    This report for the Swiss Federal Institute for Environmental Science and Technology describes product-differentiation options for small hydropower plant in Switzerland and proposes a form of differentiation based on ecological characteristics as a promising market strategy. The labels created in various countries to assure customers of the environmental compatibility of 'green' power production are looked at. In particular, the implications for small hydropower plant associated with the Swiss green power labelling procedure introduced by the Association for the Promotion of Environmentally Sound Electricity (VUE) are discussed. The report proposes a simplified procedure for these small power stations and presents a sample calculation for the overall costs of certification. The report is rounded off with four detailed case studies in which the necessary upgrades to the plant and associated costs are discussed in detail.

  4. Methane Ebullition in Temperate Hydropower Reservoirs and Implications for US Policy on Greenhouse Gas Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Benjamin L.; Arntzen, Evan V.; Goldman, Amy E.; Richmond, Marshall C.

    2017-07-21

    The United States is home to more than 87,000 dams, 2,198 of which are actively used for hydropower production. With the December 2015 consensus adoption of the United Nations Framework Convention on Climate Change’s Paris Agreement, it is imperative for the U.S. to accurately quantify greenhouse gas fluxes from its hydropower reservoirs. Methane ebullition, or methane bubbles originating from river or lake sediments, can account for nearly all of a reservoir’s methane emissions to the atmosphere. However, methane ebullition in hydropower reservoirs has been studied in only three temperate locations, none of which are in the United States. This study measures high ebullitive methane fluxes from two hydropower reservoirs in eastern Washington, synthesizes the known information about methane ebullition from tropical, boreal, and temperate hydropower reservoirs, and investigates the implications for U.S. hydropower management and growth.

  5. Hydropower versus irrigation—an analysis of global patterns

    Science.gov (United States)

    Zeng, Ruijie; Cai, Ximing; Ringler, Claudia; Zhu, Tingju

    2017-03-01

    Numerous reservoirs around the world provide multiple flow regulation functions; key among these are hydroelectricity production and water releases for irrigation. These functions contribute to energy and food security at national, regional and global levels. While reservoir operations for hydroelectricity production might support irrigation, there are also well-known cases where hydroelectricity production reduces water availability for irrigated food production. This study assesses these relationships at the global level using machine-learning techniques and multi-source datasets. We find that 54% of global installed hydropower capacity (around 507 thousand Megawatt) competes with irrigation. Regions where such competition exists include the Central United States, northern Europe, India, Central Asia and Oceania. On the other hand, 8% of global installed hydropower capacity (around 79 thousand Megawatt) complements irrigation, particularly in the Yellow and Yangtze River Basins of China, the East and West Coasts of the United States and most river basins of Southeast Asia, Canada and Russia. No significant relationship is found for the rest of the world. We further analyze the impact of climate variables on the relationships between hydropower and irrigation. Reservoir flood control functions that operate under increased precipitation levels appear to constrain hydroelectricity production in various river basins of the United States, South China and most basins in Europe and Oceania. On the other hand, increased reservoir evaporative losses and higher irrigation requirements due to higher potential evaporation levels may lead to increased tradeoffs between irrigation and hydropower due to reduced water availability in regions with warmer climates, such as India, South China, and the Southern United States. With most reservoirs today being built for multiple purposes, it is important for policymakers to understand and plan for growing tradeoffs between key

  6. The Development of Brazilian Municipalities Flooded by Hydropower Plants

    Science.gov (United States)

    Araujo, N.; Moretto, E. M.; Roquetti, D. R.; Beduschi, L. C.; Praia, A.; Pulice, S.; Albiach, E.; Athayde, S.

    2016-12-01

    Hydropower plants cause negative environmental impacts during the phases of construction and operation. On the other hand, there is a general assumption that these projects also induce local development of the affected places, since there is a great influx of social and financial capital brought locally, especially during the construction phase the relationship between hydropower plant implementation s and local development has been controversial in the Environmental Impact Assessment field, and there is no empirical evidence showing how hydroelectric dam construction affects local development. Considering municipal development as a kind of local development and operationalizing the concept of human development by adopting income, longevity and education dimensions defined by Amartya Sen, this study aimed to verify empirical evidences regarding the role of hydropower plants in human development of their flooded municipalities in Brazil. For this, we considered 134 hydroelectric plants and correspondent 641 flooded municipalities, for which 155 human development indicators were obtained for the period of 2000 to 2010. Results obtained from statistical correlation analysis and their assumption tests showed that increases in the municipal flooded area and increases in the period of flooding - to which a given municipality is submitted - were associated with lower performances of human development indicators. Specifically, increases in social inequality, poverty and lower performances of longevity and education were detected for the flooded municipalities. We also found that the financial compensation was associated with better performance of municipal income and lower performances of education and longevity. Finally, approaching the growth poles theory of François Perroux and the productive linkages theory of Albert Hirschman, we suggest that the size of the flooded areas, the flooding period and the financial compensation may lead to an enclave situation in

  7. World Small Hydropower Development Report 2013 - Eastern Africa

    CSIR Research Space (South Africa)

    Jonker Klunne, W

    2013-01-01

    Full Text Available cent) in electricity generation in Burundi, Ethiopia, Zambia, Mozambique and Malawi and it produces a significant amount of electricity in Uganda, Zimbabwe, Tanzania, Madagascar and Kenya. The island topography of Seychelles is not suitable... Energy Information Portal – Reegle3 d. Burundi information: International Renewable Energy Agency. Renewable Energy Profiles4 e. The International Journal on Hydropower & Dams5 f. Kenya, Ministry of Energy6 g. Madagascar, Agence de Développement de l...

  8. When and how to activate large new hydropower reservoirs

    Science.gov (United States)

    Geressu, Robel; Harou, Julien

    2016-04-01

    Water resources system planners are increasingly required to address multiple long and short-term management objectives and the trade-offs these imply. Expansion planning in hydropower reservoir systems, where assets either temporarily or permanently reduce each other's performance, is a complex and potentially conflictual task requiring attention to multiple impacts. This paper proposes a multi-criteria scheduling approach considering many objectives and their associated uncertainties. The method considers the coordination and flexibility of reservoir operation in different expansion stages. The impact of abstraction (i.e., during filling of new reservoirs) and regulation of inflows by upstream reservoirs, is represented by simultaneously optimizing the storage size of reservoirs. Sensitivity analysis of performance given financial uncertainty and hydrological variability reveals which expansion schedules are robust to a wide range of future conditions. This informs how alternative designs compare in multiple performance dimensions and can serve stakeholders with differing attitudes towards risk and opportunity. The method is applied to proposed Blue Nile hydropower reservoirs to find efficient new dam activation schedules considering energy revenues, downstream release requirements, and energy generation during reservoir filling periods. Results take the form of Pareto-optimal trade-offs where each point on the curve or surface represents asset choices, size, activation date, and filling period reservoir operating rules. The results help explore the complex planning and management issues involved in the Blue Nile and demonstrate a possible approach to negotiate the design, filling and coordinated use of hydropower reservoirs.

  9. The role of energy systems on hydropower in Turkey

    Directory of Open Access Journals (Sweden)

    Yuksel Ibrahim

    2017-01-01

    Full Text Available Over the last two decades, global electricity production has more than doubled and electricity demand is rising rapidly around the world as economic development spreads to emerging economies. Not only has electricity demand increased significantly, it is the fastest growing end-use of energy. Therefore, technical, economic and environmental benefits of hydroelectric power make it an important contributor to the future world energy mix, particularly in the developing countries. On the other hand, the hydropower industry is closely linked to both water management and renewable energy production, and so has a unique role to play in contributing to sustainable development in a world where billions of people lack access to safe drinking water and adequate energy supplies. In addition to, approximately 1.6 billion people have no access to electricity and about 1.1 billion are without adequate water supply. However, resources for hydropower development are widely spread around the world. Potential exists in about 150 countries, and about 70% of the economically feasible potential remains to be developed-mostly in developing countries where the needs are most urgent. This paper deals with renewable energy systems and the role of hydropower in Turkey.

  10. The role of energy systems on hydropower in Turkey

    Science.gov (United States)

    Yuksel, Ibrahim; Arman, Hasan; Halil Demirel, Ibrahim

    2017-11-01

    Over the last two decades, global electricity production has more than doubled and electricity demand is rising rapidly around the world as economic development spreads to emerging economies. Not only has electricity demand increased significantly, it is the fastest growing end-use of energy. Therefore, technical, economic and environmental benefits of hydroelectric power make it an important contributor to the future world energy mix, particularly in the developing countries. On the other hand, the hydropower industry is closely linked to both water management and renewable energy production, and so has a unique role to play in contributing to sustainable development in a world where billions of people lack access to safe drinking water and adequate energy supplies. In addition to, approximately 1.6 billion people have no access to electricity and about 1.1 billion are without adequate water supply. However, resources for hydropower development are widely spread around the world. Potential exists in about 150 countries, and about 70% of the economically feasible potential remains to be developed-mostly in developing countries where the needs are most urgent. This paper deals with renewable energy systems and the role of hydropower in Turkey.

  11. Fuzzy multiobjective models for optimal operation of a hydropower system

    Science.gov (United States)

    Teegavarapu, Ramesh S. V.; Ferreira, André R.; Simonovic, Slobodan P.

    2013-06-01

    Optimal operation models for a hydropower system using new fuzzy multiobjective mathematical programming models are developed and evaluated in this study. The models use (i) mixed integer nonlinear programming (MINLP) with binary variables and (ii) integrate a new turbine unit commitment formulation along with water quality constraints used for evaluation of reservoir downstream impairment. Reardon method used in solution of genetic algorithm optimization problems forms the basis for development of a new fuzzy multiobjective hydropower system optimization model with creation of Reardon type fuzzy membership functions. The models are applied to a real-life hydropower reservoir system in Brazil. Genetic Algorithms (GAs) are used to (i) solve the optimization formulations to avoid computational intractability and combinatorial problems associated with binary variables in unit commitment, (ii) efficiently address Reardon method formulations, and (iii) deal with local optimal solutions obtained from the use of traditional gradient-based solvers. Decision maker's preferences are incorporated within fuzzy mathematical programming formulations to obtain compromise operating rules for a multiobjective reservoir operation problem dominated by conflicting goals of energy production, water quality and conservation releases. Results provide insight into compromise operation rules obtained using the new Reardon fuzzy multiobjective optimization framework and confirm its applicability to a variety of multiobjective water resources problems.

  12. Iliotibial band syndrome in runners: a systematic review

    NARCIS (Netherlands)

    Worp, M.P. van der; Horst, N. van der; Wijer, A. de; Backx, F.J.; Nijhuis-Van der Sanden, M.W.G.

    2012-01-01

    BACKGROUND: The popularity of running is still growing and, as participation increases, the incidence of running-related injuries will also rise. Iliotibial band syndrome (ITBS) is the most common injury of the lateral side of the knee in runners, with an incidence estimated to be between 5% and

  13. Normative values of eccentric hip abduction strength in novice runners

    DEFF Research Database (Denmark)

    Ramskov, D; Pedersen, M B; Kastrup, K

    2014-01-01

    PURPOSE: Low eccentric strength of the hip abductors, might increase the risk of patellofemoral pain syndrome and iliotibial band syndrome in runners. No normative values for maximal eccentric hip abduction strength have been established. Therefore the purpose of this study was to establish norma...

  14. Runner Peanut Growth, Maturity, and Flavor Response to Prohexadione Calcium

    Science.gov (United States)

    One major challenge to producing runner market type peanuts in west Texas is the potential for early frost and poor crop maturity that could result in flavor problems. Prohexadione calcium is a plant growth regulator that inhibits the synthesis of gibberellic acid in peanut resulting in reduced vin...

  15. A modification method on runner blades in a Bulb turbine

    Energy Technology Data Exchange (ETDEWEB)

    Yang, W; Wu, Y; Liu, S, E-mail: yang-w03@mails.tsinghua.edu.c [Department of Thermal Engineering, Tsinghua University No.1 Tsinghua Park Haidian District, Beijing, 100084 (China)

    2010-08-15

    In this paper a modification method of the runner blades in a Bulb turbine is proposed, in which the main scale of the runner is maintained. In the modification method the runner blade is expressed by a gather of coordinate points. In order to make the modification simple and efficient, one of the coordinate is fixed and only the angles of the points are changed according to different modification purposes. The Bezier curve is applied to keep the modified blades smooth. For the purpose of verification, the modification method is used in some a prototype Bulb turbine in China. In order to check the modification effectiveness, a three dimensional turbulent computation is carried out through the whole passage including the bulb body, guide vanes, runner and draft tube of a prototype Bulb turbine under its rated operation. An SST k-{omega} turbulence model is used during the flow simulation. The performance prediction of the bulb turbine is conducted by the steady flow simulation. Comparisons of the computational results between the original turbine and a modified one indicate that the modification method is practical and can improve the performance of the bulb turbine.

  16. Time Evolution of Sublingual Microcirculatory Changes in Recreational Marathon Runners.

    Science.gov (United States)

    Pranskunas, Andrius; Arstikyte, Justina; Pranskuniene, Zivile; Bernatoniene, Jurga; Kiudulaite, Inga; Vaitkaitiene, Egle; Vaitkaitis, Dinas; Brazaitis, Marius

    2017-01-01

    We aimed to evaluate changes in sublingual microcirculation induced by a marathon race. Thirteen healthy male controls and 13 male marathon runners volunteered for the study. We performed sublingual microcirculation, using a Cytocam-IDF device (Braedius Medical, Huizen, Netherlands), and systemic hemodynamic measurements four times: 24 hours prior to their participation in the Kaunas Marathon (distance: 41.2 km), directly after finishing the marathon, 24 hours after the marathon, and one week after the marathon. The marathon runners exhibited a higher functional capillary density (FCD) and total vascular density of small vessels at the first visit compared with the controls. Overall, we did not find any changes in sublingual microcirculation of the marathon runners at any of the other visits. However, in a subgroup of marathon runners with a decreased FCD compared to the subgroup with increased FCD, the subgroup with decreased FCD had shorter running time (190.37 ± 30.2 versus 221.80 ± 23.4 min, p = 0.045), ingested less fluids (907 ± 615 versus 1950 ± 488 mL, p = 0.007) during the race, and lost much more weight (-2.4 ± 1.3 versus -1.0 ± 0.8 kg, p = 0.041). Recreational marathon running is not associated with an alteration of sublingual microcirculation. However, faster running and dehydration may be crucial for further impairing microcirculation.

  17. Sex differences in knee loading in recreational runners.

    Science.gov (United States)

    Sinclair, J; Selfe, J

    2015-07-16

    Patellofemoral pain is the most common chronic pathology in recreational runners. Female runners are at greater risk of developing patellofemoral pain, although the exact mechanism behind this is not fully understood. This study aimed to determine whether female recreational runners exhibit distinct knee loading compared to males. Fifteen males and 15 females recreational runners underwent 3D running analysis at 4.0 ms(-1)±5%. Sagittal/coronal joint moments, patellofemoral contact forces (PTF) and pressures (PCP) were compared between sexes. The results show that females exhibited significantly greater knee extension (p<0.008, pη(2)=0.27: males=3.04; females=3.47 N m kg(-1)) and abduction (p<0.008, pη(2)=0.28: males=0.54; females=0.82 N m kg(-1)) moments as well as PTF (p<0.008, pη(2)=0.29: males=3.25; females=3.84 B.W.) and PCP (p<0.008, pη(2)=0.26: males=7.96; females=9.27 MPa) compared to males. Given the proposed relationship between knee joint loading and patellofemoral pathology, the current investigation provides insight into the incidence of patellofemoral pain in females. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Time Evolution of Sublingual Microcirculatory Changes in Recreational Marathon Runners

    Directory of Open Access Journals (Sweden)

    Andrius Pranskunas

    2017-01-01

    Full Text Available We aimed to evaluate changes in sublingual microcirculation induced by a marathon race. Thirteen healthy male controls and 13 male marathon runners volunteered for the study. We performed sublingual microcirculation, using a Cytocam-IDF device (Braedius Medical, Huizen, Netherlands, and systemic hemodynamic measurements four times: 24 hours prior to their participation in the Kaunas Marathon (distance: 41.2 km, directly after finishing the marathon, 24 hours after the marathon, and one week after the marathon. The marathon runners exhibited a higher functional capillary density (FCD and total vascular density of small vessels at the first visit compared with the controls. Overall, we did not find any changes in sublingual microcirculation of the marathon runners at any of the other visits. However, in a subgroup of marathon runners with a decreased FCD compared to the subgroup with increased FCD, the subgroup with decreased FCD had shorter running time (190.37±30.2 versus 221.80±23.4 min, p=0.045, ingested less fluids (907±615 versus 1950±488 mL, p=0.007 during the race, and lost much more weight (-2.4±1.3 versus -1.0±0.8 kg, p=0.041. Recreational marathon running is not associated with an alteration of sublingual microcirculation. However, faster running and dehydration may be crucial for further impairing microcirculation.

  19. NSAID and other analgesic use by endurance runners during ...

    African Journals Online (AJOL)

    Background. An increasing popularity of ultra-endurance events coupled with excessive or inappropriate non-steroidal anti-inflammatory drug (NSAID) use during such events could pose considerable potential risks to runners' health. Objective. To evaluate the incidence of NSAID and other analgesic use in distance ...

  20. [Stability of the "amok runner syndrome"].

    Science.gov (United States)

    Adler, L; Marx, D; Apel, H; Wolfersdorf, M; Hajak, G

    2006-10-01

    Running amok is considered a rare but dangerous act of violence which has been investigated predominantly on a case by case basis. German-wide data on amok cases covering the decades 1980 - 1989 and 1991 - 2000 were used to perform the first epidemiological study world-wide on the stability of socio-demographic, criminological and psychiatric variables of amok behaviour. A content analysis study on nation-wide press reports of amok cases included a total of 104 subjects who were identified by combined homicidal-suicidal acts of violence and fulfilled structured criteria originally defined according to former Malayan amok events. Amok cases in both decades were comparable except for the significant increase of weapon use, especially of firearms. Total prevalence showed a tendency to decline from 1 : 5.5 million to 1 : 8.5 million men per year, females were involved in rare single cases only. The male offenders showed a bimodal age distribution with a mean of 35 years. They were professionally well qualified, but had a 5 - 7fold higher risk of unemployment than the normal population. Motives and reasons for running amok were serious but not unusual, they varied widely and addressed all areas of daily life. Most offenders were characterized by abnormal personality patterns such as passive, aggressive, impulsive and paranoid and were in possession of firearms and previously convicted. Psychiatric diseases such as psychosis, paranoia, depression or personality disorders were present in more than 50 % of cases; further 20 % were intoxicated. The presence of psychiatric disorders influenced patterns of violent behaviour in individual subjects. Victims were predominantly unknown to the offenders. Close to one third of the amok runners committed suicide or were killed by legal authorities. Amok represents a temporarily stable syndrome of extreme violent behaviour even in modern industrialized societies. Subjects exhibit a complex combination of serious causative motives

  1. Harnessing the hydropower potential in Africa: What should be the place and role of Grand Inga hydropower project?

    Energy Technology Data Exchange (ETDEWEB)

    Fall, Latsoucabe

    2010-09-15

    Harnessing Africa's huge hydropower potential should be made a priority for the sustainable development of the Continent. Particularly, Grand Inga hydropower project in DRC, due to its gigantic size (40,000 MW) and favourable natural characteristics, could be 'Africa's flagship Project of the 21st Century' offering enormous comparative advantages and opportunities for the benefits of the entire African Continent. Nevertheless, to make it a feasible and palpable 'Model Project', capable of producing clean and affordable energy, the paper tries to respond to key questions on the several daunting challenges to address for its sustainable, cost-effective and timely development and operation.

  2. ANTHROPOMETRIC, GAIT AND STRENGTH CHARACTERISTICS OF KENYAN DISTANCE RUNNERS

    Directory of Open Access Journals (Sweden)

    Pui W. Kong

    2008-12-01

    Full Text Available This study intended to take a biomechanical approach to understand the success of Kenyan distance runners. Anthropometric, gait and lower extremity strength characteristics of six elite Kenyan distance runners were analyzed. Stride frequency, relative stride length and ground contact time were measured at five running speeds (3.5 - 5.4 m/s using a motion capture system. Isometric knee extension and flexion torques were measured at six angles and hamstrings and quadriceps (H:Q ratios at three angular velocities were determined using an isokinetic dynamometer. These runners were characterized by a low body mass index (20.1 ± 1.8 kg·m- 2, low percentage body fat (5.1 ± 1.6% and small calf circumference (34.5 ± 2.3 cm. At all running speeds, the ground contact time was shorter (p < 0.05 during right (170 - 212 ms compared to left (177 - 220 ms foot contacts. No bilateral difference was observed in other gait or strength variables. Their maximal isometric strength was lower than other runners (knee extension: 1.4 - 2.6 Nm·kg-1, knee flexion: 1.0 - 1.4 Nm·kg-1 but their H:Q ratios were higher than athletes in other sports (1.03 ± 0.51 at 60o/s, 1.44 ± 0.46 at 120o/s, 1.59 ± 0.66 at 180o/s. The slim limbs of Kenyan distance runners may positively contribute to performance by having a low moment of inertia and thus requiring less muscular effort in leg swing. The short ground contact time observed may be related to good running economy since there is less time for the braking force to decelerate forward motion of the body. These runners displayed minor gait asymmetry, though the difference may be too small to be practically significant. Further investigations are needed to confirm whether the bilateral symmetry in strength and high H:Q ratios are related to genetics, training or the lack of injuries in these runners

  3. Reduced incidence of cardiac arrhythmias in walkers and runners.

    Directory of Open Access Journals (Sweden)

    Paul T Williams

    Full Text Available Walking is purported to reduce the risk of atrial fibrillation by 48%, whereas jogging is purported to increase its risk by 53%, suggesting a strong anti-arrhythmic benefit of walking over running. The purpose of these analyses is to compare incident self-reported physician-diagnosed cardiac arrhythmia to baseline energy expenditure (metabolic equivalent hours per day, METhr/d from walking, running and other exercise.Proportional hazards analysis of 14,734 walkers and 32,073 runners.There were 1,060 incident cardiac arrhythmias (412 walkers, 648 runners during 6.2 years of follow-up. The risk for incident cardiac arrhythmias declined 4.4% per baseline METhr/d walked by the walkers, or running in the runners (P = 0.0001. Specifically, the risk declined 14.2% (hazard ratio: 0.858 for 1.8 to 3.6 METhr/d, 26.5% for 3.6 to 5.4 METhr/d, and 31.7% for ≥5.4 METhr/d, relative to <1.8 METhr/d. The risk reduction per METhr/d was significantly greater for walking than running (P<0.01, but only because walkers were at 34% greater risk than runners who fell below contemporary physical activity guideline recommendations; otherwise the walkers and runners had similar risks for cardiac arrhythmias. Cardiac arrhythmias were unrelated to walking and running intensity, and unrelated to marathon participation and performance.The risk for cardiac arrhythmias was similar in walkers and runners who expended comparable METhr/d during structured exercise. We found no significant risk increase for self-reported cardiac arrhythmias associated with running distance, exercise intensity, or marathon participation. Rhythm abnormalities were based on self-report, precluding definitive categorization of the nature of the rhythm disturbance. However, even if the runners' arrhythmias include sinus bradycardia due to running itself, there was no increase in arrhythmias with greater running distance.

  4. Integrating hydropower and intermittent climate-related renewable energies: a call for hydrology

    Science.gov (United States)

    Francois, Baptiste; Anquetin, Sandrine; Creutin, Jean-Dominique; Engeland, Kolbjorn; Favre, Anne-Catherine; Hingray, Benoit; Ramos, Maria-Helena; Raynaud, Damien; Renard, Benjamin; Sauquet, Eric; Sauterleute, Julian-Friedrich; Vidal, Jean-Philippe; Warland, Geir

    2014-05-01

    Currently, the debate about the role of hydropower as energy storage and balancing energy source in context of high intermittency and variability of solar and wind energy exposes hydrologists to new challenges. There is a common consensus that a high penetration of wind and solar energies can only be achieved if the issues to their intermittent power outputs are solved - issues which can be at least partially approached by means of hydropower systems. Indeed, unlike wind and solar energies which are only produced when wind and sun are available, hydro resources can be stored in reservoirs for later use. Finally, the energy production should balance the energy demand which is to a large degree, controlled by weather variables, especially temperature. However, despite substantial work on the space-time variability of each individual hydro-meteorological variable, advances on the joint analysis of the processes that are underlying this integration are more limited. In this commentary, we analyze three specific challenges dedicated to the hydrological community. They aim to improve the integration of hydropower with solar and wind energy sources to make more effective the use of renewable energy and water resources. These challenges are: i) the need to provide a new hydro-meteorological framework for the analysis of the space-time co-fluctuations between runoff regimes and solar, wind and temperature variables; ii) understanding how processes like land-use and climate change affect the nature of these co-fluctuations; and iii) the need to develop means for a quantitative analysis of interactions between the use of water for power generation and other water uses including the preservation of aquatic ecosystems. In some way, the success of climate change mitigation policies based on high intermittent energy integration will depend on how these different challenges have been achieved by hydrologist community. The work presented is part of the FP7 project COMPLEX

  5. Reduced incidence of cardiac arrhythmias in walkers and runners.

    Science.gov (United States)

    Williams, Paul T; Franklin, Barry A

    2013-01-01

    Walking is purported to reduce the risk of atrial fibrillation by 48%, whereas jogging is purported to increase its risk by 53%, suggesting a strong anti-arrhythmic benefit of walking over running. The purpose of these analyses is to compare incident self-reported physician-diagnosed cardiac arrhythmia to baseline energy expenditure (metabolic equivalent hours per day, METhr/d) from walking, running and other exercise. Proportional hazards analysis of 14,734 walkers and 32,073 runners. There were 1,060 incident cardiac arrhythmias (412 walkers, 648 runners) during 6.2 years of follow-up. The risk for incident cardiac arrhythmias declined 4.4% per baseline METhr/d walked by the walkers, or running in the runners (P = 0.0001). Specifically, the risk declined 14.2% (hazard ratio: 0.858) for 1.8 to 3.6 METhr/d, 26.5% for 3.6 to 5.4 METhr/d, and 31.7% for ≥5.4 METhr/d, relative to cardiac arrhythmias. Cardiac arrhythmias were unrelated to walking and running intensity, and unrelated to marathon participation and performance. The risk for cardiac arrhythmias was similar in walkers and runners who expended comparable METhr/d during structured exercise. We found no significant risk increase for self-reported cardiac arrhythmias associated with running distance, exercise intensity, or marathon participation. Rhythm abnormalities were based on self-report, precluding definitive categorization of the nature of the rhythm disturbance. However, even if the runners' arrhythmias include sinus bradycardia due to running itself, there was no increase in arrhythmias with greater running distance.

  6. Bone stress in runners with tibial stress fracture.

    Science.gov (United States)

    Meardon, Stacey A; Willson, John D; Gries, Samantha R; Kernozek, Thomas W; Derrick, Timothy R

    2015-11-01

    Combinations of smaller bone geometry and greater applied loads may contribute to tibial stress fracture. We examined tibial bone stress, accounting for geometry and applied loads, in runners with stress fracture. 23 runners with a history of tibial stress fracture & 23 matched controls ran over a force platform while 3-D kinematic and kinetic data were collected. An elliptical model of the distal 1/3 tibia cross section was used to estimate stress at 4 locations (anterior, posterior, medial and lateral). Inner and outer radii for the model were obtained from 2 planar x-ray images. Bone stress differences were assessed using two-factor ANOVA (α=0.05). Key contributors to observed stress differences between groups were examined using stepwise regression. Runners with tibial stress fracture experienced greater anterior tension and posterior compression at the distal tibia. Location, but not group, differences in shear stress were observed. Stepwise regression revealed that anterior-posterior outer diameter of the tibia and the sagittal plane bending moment explained >80% of the variance in anterior and posterior bone stress. Runners with tibial stress fracture displayed greater stress anteriorly and posteriorly at the distal tibia. Elevated tibial stress was associated with smaller bone geometry and greater bending moments about the medial-lateral axis of the tibia. Future research needs to identify key running mechanics associated with the sagittal plane bending moment at the distal tibia as well as to identify ways to improve bone geometry in runners in order to better guide preventative and rehabilitative efforts. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Genetic aspects of athletic performance: the African runners phenomenon

    Directory of Open Access Journals (Sweden)

    Vancini RL

    2014-05-01

    Full Text Available Rodrigo Luiz Vancini,1 João Bosco Pesquero,2 Rafael Júlio Fachina,3,4 Marília dos Santos Andrade,1 João Paulo Borin,3 Paulo César Montagner,3 Claudio Andre Barbosa de Lira51Centro de Educação Física e Desportos, Universidade Federal do Espírito Santo, Vitória, Espírito Santo, Brazil; 2Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, Brazil; 3Departamento de Ciência do Esporte, Faculdade de Educação Física, Universidade Estadual de Campinas, Campinas, Brazil; 4Confederação Brasileira de Basquetebol, Rio de Janeiro, Brazil; 5Setor de Fisiologia Humana e do Exercício, Faculdade de Educação Física, Universidade Federal de Goiás, Goiânia, BrazilAbstract: The current dominance of African runners in long-distance running is an intriguing phenomenon that highlights the close relationship between genetics and physical performance. Many factors in the interesting interaction between genotype and phenotype (eg, high cardiorespiratory fitness, higher hemoglobin concentration, good metabolic efficiency, muscle fiber composition, enzyme profile, diet, altitude training, and psychological aspects have been proposed in the attempt to explain the extraordinary success of these runners. Increasing evidence shows that genetics may be a determining factor in physical and athletic performance. But, could this also be true for African long-distance runners? Based on this question, this brief review proposed the role of genetic factors (mitochondrial deoxyribonucleic acid, the Y chromosome, and the angiotensin-converting enzyme and the alpha-actinin-3 genes in the amazing athletic performance observed in African runners, especially the Kenyans and Ethiopians, despite their environmental constraints.Keywords: genes, genotype, physical exercise, endurance runners

  8. Musculoskeletal pain is prevalent among recreational runners who are about to compete: an observational study of 1049 runners

    NARCIS (Netherlands)

    Lopes, A.D.; Costa, L.O.P.; Saragiotto, B.T.; Yamato, T.P.; Adami, F.; Verhagen, E.A.L.M.

    2011-01-01

    Question: What is the prevalence and nature of musculoskeletal pain in recreational runners immediately before a race? Design: Cross-sectional survey. Participants: Adults intending to compete in a recreational running race between 5000 and 10 000 metres. Measures: Demographic data collected about

  9. Influence of endurance running on calcaneal bone stiffness in male and female runners.

    Science.gov (United States)

    Lara, Beatriz; Salinero, Juan José; Gutiérrez, Jorge; Areces, Francisco; Abián-Vicén, Javier; Ruiz-Vicente, Diana; Gallo-Salazar, César; Jiménez, Fernando; Del Coso, Juan

    2016-02-01

    The aim of this investigation was to determine the influence of endurance running on calcaneus bone stiffness in male and female runners. A total of 122 marathoners (longer distance runners, men = 101; women = 21) and 81 half-marathon and 10-km runners (shorter distance runners; men = 48; women = 33), competing in an international running event, underwent an ultrasonographic assessment of the right and left calcaneus. Calcaneus bone stiffness was estimated using the measurements of the speed of sound (SOS) and broadband ultrasound attenuation (BUA). Seventy-five age-matched sedentary people served as the control group. Male and female longer distance runners and shorter distance runners presented higher values than sedentary counterparts in SOS (P < 0.05), and calcaneus stiffness (P < 0.05). Although there were no significant differences between longer distance and shorter distance runners in the ultrasonographic variables, longer distance runners presented greater effects size in SOS (1.00 vs. 0.93 males; 1.10 vs. 0.77 females), BUA (0.62 vs. 0.25 males; 0.89 vs. 0.20 females) and calcaneus stiffness (0.88 vs. 0.66 males; 1.20 vs. 0.60 females) than shorter distance endurance runners. Calcaneus bone stiffness was higher in all endurance runners compared to a sedentary control population. The volume of ground reaction forces which occur during endurance running might induce the adaptation of the calcaneus bone.

  10. Cardiac biomarkers, electrolytes, and other analytes in collapsed marathon runners: implications for the evaluation of runners following competition.

    Science.gov (United States)

    Siegel, Arthur J; Januzzi, James; Sluss, Patrick; Lee-Lewandrowski, Elizabeth; Wood, Malissa; Shirey, Terry; Lewandrowski, Kent B

    2008-06-01

    We measured analytes in collapsed Boston Marathon runners to compare with changes in asymptomatic runners. Of collapsed runners at the 2007 marathon, 18.2% had a measurable cardiac troponin T (cTnT) value with a mean postrace level of 0.017 ng/mL (0.017 microg/L; SD, 0.02 ng/mL [0.02 microg/L]). Three subjects had cTnT values above the cutoff (0.10 ng/mL [0.10 microg/L]) typically used for the diagnosis of acute myocardial infarction. The mean and median N-terminal pro-B-type natriuretic peptide levels were 73 ng/L (SD, 77.3 ng/L) and 54.3 ng/L (interquartile range, 22.8-87.3 ng/L), respectively, in collapsed runners. Only 4.9% had values more than the age-specific normal value (<125 ng/L for subjects younger than 75 years). In collapsed subjects at the 2006 marathon, 18.0% had an abnormal sodium value, including 18 cases of hypernatremia and 7 cases of hyponatremia. The ionized calcium level was low in 49% of subjects, and the ionized magnesium level was low in 19.5% and elevated in 1 subject. The blood lactate level was elevated in 95% of subjects. The frequency of elevated postrace cTnT levels in collapsed athletes after endurance exercise is similar to that in asymptomatic runners. Other metabolic abnormalities, including hypernatremia, hyponatremia, low ionized calcium and magnesium levels, and lactic acidosis may contribute to muscle fatigue and collapse.

  11. Incidence of chronic knee lesions in long-distance runners based on training level: Findings at MRI

    Energy Technology Data Exchange (ETDEWEB)

    Schueller-Weidekamm, Claudia [Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)]. E-mail: claudia.schueller-weidekamm@meduniwien.ac.at; Schueller, Gerd [Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Uffmann, Martin [Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Bader, Till [Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)

    2006-05-15

    Purpose: The purpose of this study was to evaluate the incidence of chronic knee changes in long-distance runners based on the training status, including distance, running frequency, training pace, and running experience. Methods: MRI of the knee was performed in 26 non-professional runners 5 days after their last training unit. Lesions of the menisci and cartilage (5-point scale), bone marrow and ligaments (3-point scale), and joint effusion were evaluated. A total score comprising all knee lesions in each runner was evaluated. The incidence of the knee changes was correlated with the training level, gender, and age of the runners. Results: Grade 1 lesions of the menisci were found in six runners with a high training level, and in only four runners with a low training level. Grade 1 cartilage lesions were found in three high-trained runners and in one low-trained runner, and grade 2 lesions were found in one high-trained runner and in two low-trained runners, respectively. Grade 1 anterior cruciate ligament lesions were seen in three runners with a high- and in two runners with a low-training level. Runners with a higher training level showed a statistically significant higher score for all chronic knee lesions than those with a lower training level (p < 0.05). Conclusions: MRI findings indicate that a higher training level in long-distance runners is a risk factor for chronic knee lesions.

  12. Effect of age and performance on pacing of marathon runners

    Directory of Open Access Journals (Sweden)

    Nikolaidis PT

    2017-08-01

    Full Text Available Pantelis Theodoros Nikolaidis,1 Beat Knechtle2,3 1Exercise Physiology Laboratory, Attiki, Greece; 2Gesundheitszentrum St. Gallen, St. Gallen, 3Institute of Primary Care, University of Zurich, Zurich, Switzerland Abstract: Pacing strategies in marathon runners have previously been examined, especially with regard to age and performance level separately. However, less information about the age × performance interaction on pacing in age-group runners exists. The aim of the present study was to examine whether runners with similar race time and at different age differ for pacing. Data (women, n=117,595; men, n=180,487 from the “New York City Marathon” between 2006 and 2016 were analyzed. A between–within subjects analysis of variance showed a large main effect of split on race speed (p<0.001, η2=0.538 with the fastest speed in the 5–10 km split and the slowest in the 35–40 km. A small sex × split interaction on race speed was found (p<0.001, η2=0.035 with men showing larger increase in speed at 5 km and women at 25 km and 40 km (end spurt. An age-group × performance group interaction on Δspeed was shown for both sexes at 5 km, 10 km, 15 km, 20 km, 25 km, 30 km, 35 km, and 40 km (p<0.001, 0.001≤η2≤0.004, where athletes in older age-groups presented a relatively more even pace compared with athletes in younger age-groups, a trend that was more remarkable in the relatively slow performance groups. So far, the present study is the first one to observe an age × performance interaction on pacing; ie, older runners pace differently (smaller changes than younger runners with similar race time. These findings are of great practical interest for coaches working with marathon runners of different age, but similar race time. Keywords: running, master athlete, endurance, aerobic capacity, fatigue, gender, race time

  13. 77 FR 51551 - Proposed Renewal of Information Collection: Alternatives Process in Hydropower Licensing

    Science.gov (United States)

    2012-08-24

    ... Office of the Secretary Proposed Renewal of Information Collection: Alternatives Process in Hydropower..., Department of the Interior is announcing its intention to request renewal approval for the collection of information for Alternatives Process in Hydropower Licensing. This collection request has been forwarded to...

  14. 77 FR 30308 - Proposed Renewal of Information Collection: Alternatives Process in Hydropower Licensing

    Science.gov (United States)

    2012-05-22

    ... Office of the Secretary Proposed Renewal of Information Collection: Alternatives Process in Hydropower... Process in Hydropower Licensing, OMB Control Number 1094-0001. FOR FURTHER INFORMATION CONTACT: To request... mail to [email protected] . SUPPLEMENTARY INFORMATION: I. Abstract This notice is for renewal of...

  15. 75 FR 7469 - Panel Member List for Hydropower Licensing Study Dispute Resolution; Notice Extending Filing Date...

    Science.gov (United States)

    2010-02-19

    ... Energy Regulatory Commission Panel Member List for Hydropower Licensing Study Dispute Resolution; Notice Extending Filing Date for Applications for Panel Member List for Hydropower Licensing Study Dispute...) requested applications to be included on a list of resource experts willing to serve as a third panel member...

  16. "Fish Friendly" Hydropower Turbine Development and Deployment. Alden Turbine Preliminary Engineering and Model Testing

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, D. [Electric Power Research Institute, Palo Alto, CA (United States)

    2011-10-01

    This report presents the results of a collaborative research project funded by the Electric Power Research Institute (EPRI), the U.S. Department of Energy (DOE), and hydropower industry partners with the objective of completing the remaining developmental engineering required for a “fish-friendly” hydropower turbine called the Alden turbine.

  17. An optimal hydropower contract load determination method considering both human and riverine ecosystem needs

    Science.gov (United States)

    Yin, Xin'an; Yang, Zhifeng; Liu, Cailing; Zhao, Yanwei

    2015-09-01

    In this research, a new method is developed to determine the optimal contract load for a hydropower reservoir, which is achieved by incorporating environmental flows into the determination process to increase hydropower revenues, while mitigating the negative impacts of hydropower generation on riverine ecosystems. In this method, the degree of natural flow regime alteration is adopted as a constraint of hydropower generation to protect riverine ecosystems, and the maximization of mean annual revenue is set as the optimization objective. The contract load in each month and the associated reservoir operating parameters were simultaneously optimized by a genetic algorithm. The proposed method was applied to China's Wangkuai Reservoir to test its effectiveness. The new method offers two advantages over traditional studies. First, it takes into account both the economic benefits and the ecological needs of riverine systems, rather than only the economic benefits, as in previous methods. Second, although many measures have been established to mitigate the negative ecological impacts of hydropower generation, few have been applied to the hydropower planning stage. Thus, since the contract load is an important planning parameter for hydropower generation, influencing both economic benefits and riverine ecosystem protection, this new method could provide guidelines for the establishment of river protection measures at the hydropower planning stage.

  18. Assessing residual hydropower potential of the La Plata Basin accounting for future user demands

    Directory of Open Access Journals (Sweden)

    I. Popescu

    2012-08-01

    Full Text Available La Plata Basin is shared by five countries (Argentina, Bolivia, Brazil, Paraguay and Uruguay, which have fast growing economies in South America. These countries need energy for their sustainable development; hence, hydropower can play a very important role as a renewable clean source of energy. This paper presents an analysis of the current hydropower production and electricity demand in La Plata Basin (LPB, and it analyses the maximum and residual hydropower potential of the basin for a horizon of 30 yr (i.e. year 2040. Current hydropower production is estimated based on historical available data, while future energy production is deduced from the available water in the catchment (estimated based on measured hydrographs of the past years, whereas electricity demand is assessed by correlating existing electricity demand with the estimated population growth and economic development. The maximum and residual hydropower potential of the basin were assessed for the mean annual flows of the present hydrological regime (1970–2000 and topographical characteristics of the area.

    Computations were performed using an integrated GIS environment called VAPIDRO-ASTE released by the Research on Energy System (Italy. The residual hydropower potential of the basin is computed considering first that the water supply needs for population, industry and agriculture are served, and then hydropower energy is produced. The calculated hydropower production is found to be approximately half of the estimated electricity demand, which shows that there is a need to look for other sources of energy in the future.

  19. Assessing residual hydropower potential of the La Plata Basin accounting for future user demands

    Science.gov (United States)

    Popescu, I.; Brandimarte, L.; Perera, M. S. U.; Peviani, M.

    2012-08-01

    La Plata Basin is shared by five countries (Argentina, Bolivia, Brazil, Paraguay and Uruguay), which have fast growing economies in South America. These countries need energy for their sustainable development; hence, hydropower can play a very important role as a renewable clean source of energy. This paper presents an analysis of the current hydropower production and electricity demand in La Plata Basin (LPB), and it analyses the maximum and residual hydropower potential of the basin for a horizon of 30 yr (i.e. year 2040). Current hydropower production is estimated based on historical available data, while future energy production is deduced from the available water in the catchment (estimated based on measured hydrographs of the past years), whereas electricity demand is assessed by correlating existing electricity demand with the estimated population growth and economic development. The maximum and residual hydropower potential of the basin were assessed for the mean annual flows of the present hydrological regime (1970-2000) and topographical characteristics of the area. Computations were performed using an integrated GIS environment called VAPIDRO-ASTE released by the Research on Energy System (Italy). The residual hydropower potential of the basin is computed considering first that the water supply needs for population, industry and agriculture are served, and then hydropower energy is produced. The calculated hydropower production is found to be approximately half of the estimated electricity demand, which shows that there is a need to look for other sources of energy in the future.

  20. Multi-model assessment of global hydropower and cooling water discharge potential under climate change

    NARCIS (Netherlands)

    Vliet, van M.T.H.; Beek, van L.P.H.; Eisner, S.; Flörke, M.; Wada, Y.; Bierkens, M.F.P.

    2016-01-01

    Worldwide, 98% of total electricity is currently produced by thermoelectric power and hydropower. Climate change is expected to directly impact electricity supply, in terms of both water availability for hydropower generation and cooling water usage for thermoelectric power. Improved

  1. Complementing hydropower with PV and wind: optimal energy mix in a fully renewable Switzerland

    Science.gov (United States)

    Dujardin, Jérôme; Kahl, Annelen; Kruyt, Bert; Lehning, Michael

    2017-04-01

    Like several other countries, Switzerland plans to phase out its nuclear power production and will replace most or all of it by renewables. Switzerland has the chance to benefit from a large hydropower potential and has already exploited almost all of it. Currently about 60% of the Swiss electricity consumption is covered by hydropower, which will eventually leave a gap of about 40% to the other renewables mainly composed of photovoltaics (PV) and wind. With its high flexibility, storage hydropower will play a major role in the future energy mix, providing valuable power and energy balance. Our work focuses on the interplay between PV, wind and storage hydropower, to analyze the dynamics of this complex system and to identify the best PV-wind mixing ratio. Given the current electricity consumption and the currently installed pumping capacity of the storage hydropower plants, it appears that the Swiss hydropower system can completely alleviate the intermittency of PV and wind. However, some seasonal mismatch between production and demand will remain, but we show that oversizing the production from PV and wind or enlarging the reservoir capacity can be a solution to keep it to an acceptable level or even eliminate it. We found that PV, wind and hydropower performs the best together when the share of PV in the solar - wind mix is between 20 and 60%. These findings are quantitatively specific for Switzerland but qualitatively transferable to similar mountainous environments with abundant hydropower resources.

  2. High-resolution assessment of global technical and economic hydropower potential

    NARCIS (Netherlands)

    Gernaat, David E.H.J.; Bogaart, Patrick W.; Vuuren, van Detlef P.; Biemans, Hester; Niessink, Robin

    2017-01-01

    Hydropower is the most important renewable energy source to date, providing over 72% of all renewable electricity globally. Yet, only limited information is available on the global potential supply of hydropower and the associated costs. Here we provide a high-resolution assessment of the technical

  3. Small Hydropower Plants in Pomerania: The Example of Evolution of Modern Industrial Brick Architecture

    Science.gov (United States)

    Macikowski, Bartosz

    2017-10-01

    hydropower plants should be one of the carriers of the new progressive architecture. In fact, in the case of the Pomeranian hydropower plants, their technical solutions were among the most advanced and progressive solutions of those times, sometimes even experimental, adjusted to the diversity of local geographical conditions. Regardless of that, the architecture of the Pomeranian power plants was rather reflecting the diversity and dynamism of the aesthetic discourse of the time (sometimes even representing and adopting traditional or historical forms). The cascade of the power plants Podgaje (1928), Jastrowie (1930), and Ptusza (1930), all part of the same investment on the river Gwda, can be the example of the absorption and development of new aesthetic trends within the same stream of clinker architecture. The paper describes selected examples of Pomeranian power plants as a comparative study which could illustrate the evolution of the brick architecture of the beginning of the 20th century.

  4. Experimental investigation of a Kaplan runner under steady-state and transient operations

    OpenAIRE

    Amiri, Kaveh

    2016-01-01

    Hydropower is a key part in electricity production nowadays. Hydropower electricity production rose to 3579.5 TWh in 2013, ranked as the second source of electricity production in the world after fossil fuels. It is the principle source of renewable electricity production, producing 16.2% of the electricity in 2013, accounting for 78% of the renewable electricity production in the world. Specifically in Sweden, hydropower is the main source of electricity production producing 47.5% of the req...

  5. Interactions between land use, climate and hydropower in Scotland

    Science.gov (United States)

    Sample, James

    2015-04-01

    To promote the transition towards a low carbon economy, the Scottish Government has adopted ambitious energy targets, including generating all electricity from renewable sources by 2020. To achieve this, continued investment will be required across a range of sustainable technologies. Hydropower has a long history in Scotland and the present-day operational capacity of ~1.5 GW makes a substantial contribution to the national energy budget. In addition, there remains potential for ~500 MW of further development, mostly in the form of small to medium size run-of-river schemes. Climate change is expected to lead to an intensification of the global hydrological cycle, leading to changes in both the magnitude and seasonality of river flows. There may also be indirect effects, such as changing land use, enhanced evapotranspiration rates and an increased demand for irrigation, all of which could affect the water available for energy generation. Preliminary assessments of hydropower commonly use flow duration curves (FDCs) to estimate the power generation potential at proposed new sites. In this study, we use spatially distributed modelling to generate daily and monthly FDCs on a 1 km by 1 km grid across Scotland, using a variety of future land use and climate change scenarios. Parameter-related uncertainty in the model has been constrained using Bayesian Markov Chain Monte Carlo (MCMC) techniques to derive posterior probability distributions for key model parameters. Our results give an indication of the sensitivity and vulnerability of Scotland's run-of-river hydropower resources to possible changes in climate and land use. The effects are spatially variable and the range of uncertainty is sometimes large, but consistent patterns do emerge. For example, many locations are predicted to experience enhanced seasonality, with significantly lower power generation potential in the summer months and greater potential during the autumn and winter. Some sites may require

  6. Assessment of the Effects of Climate Change on Federal Hydropower

    Energy Technology Data Exchange (ETDEWEB)

    Sale, Michael J. [M.J. Sale and Associates, Hanson, MA (United States); Shih-Chieh, Kao [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ashfaq, Moetasim [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kaiser, Dale P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Martinez, Rocio [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Webb, Cindy [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wei, Yaxing [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2012-10-01

    As directed by Congress in Section 9505 of the SECURE Water Act of 2009 (Public Law 111-11), the US Department of Energy (DOE), in consultation with the federal Power Marketing Administrations (PMAs) and other federal agencies, including federal dam owners, has prepared a comprehensive assessment examining the effects of climate change on water available for hydropower at federal facilities and on the marketing of power from these federal facilities. This Oak Ridge National Laboratory report, referred to as the “9505 Assessment,” describes the technical basis for the report to Congress that was called for in the SECURE Water Act.

  7. Decision making algorithms for hydro-power plant location

    CERN Document Server

    Majumder, Mrinmoy

    2013-01-01

    The present study has attempted to apply the advantage of neuro-genetic algorithms for optimal decision making in maximum utilization of natural resources. Hydro-power is one of the inexpensive, but a reliable source of alternative energy which is foreseen as the possible answer to the present crisis in the energy sector. However, the major problem related to hydro-energy is its dependency on location. An ideal location can produce maximum energy with minimum loss. Besides, such power-plant also requires substantial amount of land which is a precious resource nowadays due to the rapid and unco

  8. Effects of Climate Change on Federal Hydropower. Report to Congress

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-08-01

    This is a formal Department of Energy report to Congress. It outlines the findings of an assessment directed by Congress in Section 9505 of the SECURE Water Act of 2009 (Public Law 111-11), the US Department of Energy (DOE), in consultation with the federal Power Marketing Administrations (PMAs) and other federal agencies, including federal dam owners, has prepared a comprehensive assessment examining the effects of climate change on water available for hydropower at federal facilities and on the marketing of power from these federal facilities.

  9. The effect of shoe type on gait in forefoot strike runners during a 50-km run

    OpenAIRE

    Kasmer, Mark E.; Ketchum, Nicholas C.; Liu, Xue-Cheng

    2014-01-01

    Purpose: To observe the relative change in foot-strike pattern, pressure characteristics, surface electromyography (sEMG) recordings, and stride characteristics in forefoot strike runners wearing both minimalist and traditional shoes during a 50-km run. Methods: Four experienced minimalist runners were enrolled in this study. Each runner ran a 50-km simulated run in both minimalist shoes and traditional shoes. Pressure data, sEMG recordings, and limited 3D motion capture data were collecte...

  10. Eco-runner team Delft; the most fuel efficient vehicle in the world

    OpenAIRE

    Rijks, F.

    2014-01-01

    The slogan, ‘Eco-Runner: the most fuel efficient vehicle in the world’ of the Eco-Runner Team Delft says it all: designing and building the most fuel efficient vehicle in the world. The Eco-Runner Team is a ‘D:DREAM Team’ where students from various faculties work together to design and build extremely efficient, hydrogen powered vehicles and conduct research in the fields of aerodynamics, structures, electronics, hydrogen fuel cells and driving strategies.

  11. Frequency Stability of Hierarchically Controlled Hybrid Photovoltaic-Battery-Hydropower Microgrids

    DEFF Research Database (Denmark)

    Guan, Yajuan; Quintero, Juan Carlos Vasquez; Guerrero, Josep M.

    2015-01-01

    is derived to analyze the system stability of the hybrid microgrid. The simulation results show system frequency and voltage stability for a hybrid microgrid demonstration which includes 2 MWp PV installations, a 15.2 MWh battery system, and a 12.8 MVA hydropower plant. Experimental results on a small......Hybrid photovoltaic (PV) -battery-hydropower microgrids can be considered to enhance electricity accessibility and availability in remote areas. However, the coexistence of different renewable energy sources with different inertias and control strategies may affect system stability. In this paper......, a hierarchical controller for hybrid PV-battery-hydropower microgrid is proposed in order to achieve the parallel operation of hydropower and PV-battery system with different rates, and to guarantee power sharing performance among PV voltage controlled inverters, while the required power to hydropower...

  12. Nerve entrapment of the foot and ankle in runners.

    Science.gov (United States)

    Murphy, P C; Baxter, D E

    1985-10-01

    In the 10 years 1972 through 1982, the senior author performed 21 operations on 15 runners with persistent foot and ankle pain. The operative procedures involved decompression of peripheral nerves in the foot and ankle, consisting of release of soft tissues in the tarsal tunnel and foot or removal of abnormal bony excrescences that were irritating these nerves. All 15 runners had good to excellent results and all returned to their preinjury running status, including the competitive athletes. Foot and ankle pain is best treated conservatively, but when signs and symptoms culled from a careful history and physical examination reflect a nerve entrapment syndrome, surgical intervention has its place in the armamentarium of the surgeon.

  13. [Long-term success and risk for marathon runners].

    Science.gov (United States)

    Schueller-Weidekamm, C

    2010-05-01

    The popularity of marathon running has increased during recent years, which is reflected by the dramatic increase in the number of competitions and participants. Running a marathon itself does not usually cause any severe lesions of the joints but the problems mostly occur during training prior to the marathon. Before the event runners often question whether they can successfully take part in the competition and cope with the pain that might occur during running. In addition to the rare acute trauma, which is in general caused by falls or slipping, chronic injuries are of particular relevance for long distance running.This article describes the typical patterns of injuries to long distance runners, the positive effects of running a marathon and the risk factors for injuries.

  14. The impacts of climate change on a Norwegian high-head hydropower plant

    Energy Technology Data Exchange (ETDEWEB)

    Chernet, Haregewoin Haile; Alfredsen, Knut; Killintveit, Aanund

    2010-07-01

    Full text: Norway relies on hydropower for 99 percent of the electricity production and thus Hydropower is important for Norway today and in the future energy system. The work presented in this paper shows how a high-head hydropower system in Norway will be affected in the future climate. The Aurland Hydropower system, operated by E-Co Vannkraft, Norway is the test case for the study. The Aurland hydropower system has many reservoirs and transfer systems and is considered to be one of the complex systems in Norway, but also a typical example of a Norwegian high head system. The nMAG Hydropower simulation model, which has been developed at the Norwegian Hydro technical Laboratory, is used to simulate the hydropower system. Historical and future inflow series were transposed from the neighbouring catchment Flaamselvi using scaling based on area and specific runoff, as there is no discharge station in Aurland catchment with long unregulated inflow series to set up the model and to be used for developing future climate scenarios. To generate the future inflow series for the analysis, the HBV hydrological model is calibrated for the Flaamselvi catchment. The model is then used to generate future inflow series of using the Hadley GCM (HADAm3) and A2, B2 climate scenarios. The operation of the hydropower system is then simulated for the period 2071 -2100 to see how future power production is affected by the change in the inflow conditions. The HBV model is also used to see how snow accumulation will be affected in the future as snow melt is important for Norwegian reservoir and hydropower systems. The Hydrologic scenarios under climate change imply an average increase in runoff for the system. Snow accumulation will decrease with sooner snow melt and more winter precipitation as rain. The hydropower simulation results show that associated with the increase in runoff there is an increase in energy generation with 10-20% under the current reservoir operation strategies

  15. A Comparison of Dietary Habits between Recreational Runners and a Randomly Selected Adult Population in Slovenia.

    Science.gov (United States)

    Škof, Branko; Rotovnik Kozjek, Nada

    2015-09-01

    The aim of the study was to compare the dietary habits of recreational runners with those of a random sample of the general population. We also wanted to determine the influence of gender, age and sports performance of recreational runners on their basic diet and compliance with recommendations in sports nutrition. The study population consisted of 1,212 adult Slovenian recreational runners and 774 randomly selected residents of Slovenia between the ages of 18 and 65 years. The data on the dietary habits of our subjects was gathered by means of two questionnaires. The following parameters were evaluated: the type of diet, a food pattern, and the frequency of consumption of individual food groups, the use of dietary supplements, fluid intake, and alcohol consumption. Recreational runners had better compliance with recommendations for healthy nutrition than the general population. This pattern increased with the runner's age and performance level. Compared to male runners, female runners ate more regularly and had a more frequent consumption of food groups associated with a healthy diet (fruit, vegetables, whole grain foods, and low-fat dairy products). The consumption of simple sugars and use of nutritional supplements by well-trained runners was inadequate with values recommended for physically active individuals. Recreational runners are an exemplary population group that actively seeks to adopt a healthier lifestyle.

  16. A prospective study on time to recovery in 254 injured novice runners.

    Directory of Open Access Journals (Sweden)

    Rasmus Oestergaard Nielsen

    Full Text Available Describe the diagnoses and the time to recovery of running-related injuries in novice runners.Prospective cohort study on injured runners.This paper is a secondary data analysis of a 933-person cohort study (DANO-RUN aimed at characterizing risk factors for injury in novice runners. Among those sustaining running-related injuries, the types of injuries and time to recovery is described in the present paper. All injured runners were diagnosed after a thorough clinical examination and then followed prospectively during their recovery. If they recovered completely from injury, time to recovery of each injury was registered.A total of 254 runners were injured. The proportion of runners diagnosed with medial tibial stress syndrome was 15%, 10% for patellofemoral pain, 9% for medial meniscal injury, 7% for Achilles tendinopathy and 5% for plantar fasciitis. Among the 220 runners (87% recovering from their injury, the median time to recovery was 71 days (minimum  = 9 days, maximum  = 617 days.Medial tibial stress syndrome was the most common injury followed by patellofemoral pain, medial meniscal injury and Achilles tendinopathy. Half of the injured runners were unable to run 2×500 meters without pain after 10 weeks. Almost 5% of the injured runners received surgical treatment.

  17. A prospective study on time to recovery in 254 injured novice runners.

    Science.gov (United States)

    Nielsen, Rasmus Oestergaard; Rønnow, Lotte; Rasmussen, Sten; Lind, Martin

    2014-01-01

    Describe the diagnoses and the time to recovery of running-related injuries in novice runners. Prospective cohort study on injured runners. This paper is a secondary data analysis of a 933-person cohort study (DANO-RUN) aimed at characterizing risk factors for injury in novice runners. Among those sustaining running-related injuries, the types of injuries and time to recovery is described in the present paper. All injured runners were diagnosed after a thorough clinical examination and then followed prospectively during their recovery. If they recovered completely from injury, time to recovery of each injury was registered. A total of 254 runners were injured. The proportion of runners diagnosed with medial tibial stress syndrome was 15%, 10% for patellofemoral pain, 9% for medial meniscal injury, 7% for Achilles tendinopathy and 5% for plantar fasciitis. Among the 220 runners (87%) recovering from their injury, the median time to recovery was 71 days (minimum  = 9 days, maximum  = 617 days). Medial tibial stress syndrome was the most common injury followed by patellofemoral pain, medial meniscal injury and Achilles tendinopathy. Half of the injured runners were unable to run 2×500 meters without pain after 10 weeks. Almost 5% of the injured runners received surgical treatment.

  18. The fastest runner on artificial legs: different limbs, similar function?

    Science.gov (United States)

    Weyand, Peter G; Bundle, Matthew W; McGowan, Craig P; Grabowski, Alena; Brown, Mary Beth; Kram, Rodger; Herr, Hugh

    2009-09-01

    The recent competitive successes of a bilateral, transtibial amputee sprint runner who races with modern running prostheses has triggered an international controversy regarding the relative function provided by his artificial limbs. Here, we conducted three tests of functional similarity between this amputee sprinter and competitive male runners with intact limbs: the metabolic cost of running, sprinting endurance, and running mechanics. Metabolic and mechanical data, respectively, were acquired via indirect calorimetry and ground reaction force measurements during constant-speed, level treadmill running. First, we found that the mean gross metabolic cost of transport of our amputee sprint subject (174.9 ml O(2)*kg(-1)*km(-1); speeds: 2.5-4.1 m/s) was only 3.8% lower than mean values for intact-limb elite distance runners and 6.7% lower than for subelite distance runners but 17% lower than for intact-limb 400-m specialists [210.6 (SD 13.2) ml O(2)*kg(-1)*km(-1)]. Second, the speeds that our amputee sprinter maintained for six all-out, constant-speed trials to failure (speeds: 6.6-10.8 m/s; durations: 2-90 s) were within 2.2 (SD 0.6)% of those predicted for intact-limb sprinters. Third, at sprinting speeds of 8.0, 9.0, and 10.0 m/s, our amputee subject had longer foot-ground contact times [+14.7 (SD 4.2)%], shorter aerial [-26.4 (SD 9.9)%] and swing times [-15.2 (SD 6.9)%], and lower stance-averaged vertical forces [-19.3 (SD 3.1)%] than intact-limb sprinters [top speeds = 10.8 vs. 10.8 (SD 0.6) m/s]. We conclude that running on modern, lower-limb sprinting prostheses appears to be physiologically similar but mechanically different from running with intact limbs.

  19. Concentration of Ca in blood of amateur runners using NAA

    Science.gov (United States)

    Kovacs, L.; Zamboni, C. B.; Metairon, S.; Nunes, L. A. S.; Lourenço, T. F.; Macedo, D. V.

    2013-05-01

    In this study the Ca levels were determined in amateur runners blood at LABEX (Laboratório de Bioquímica do Exercício - UNICAMP, Brazil), using Neutron Activation Analyses (NAA) technique. The range established at rest (162 - 410 mgL-1) when compared with control group (51 - 439 mgL-1) suggests that there is a dependency of these limits in the function of the adopted physical training.

  20. Concentration of Ca in blood of amateur runners using NAA

    Energy Technology Data Exchange (ETDEWEB)

    Kovacs, L.; Zamboni, C. B.; Metairon, S. [Instituto de Pesquisas Energeticas e Nucleares (IPEN / CNEN - SP) - Centro do Reator de Pesquisas Av. Professor Lineu Prestes, 2242 - 05508-000 Sao Paulo, SP (Brazil); Nunes, L. A. S.; Lourenco, T. F.; Macedo, D. V. [Universidade Estadual de Campinas - UNICAMP - Laboratorio de Bioquimica do Exercicio - LABEX Cidade Universitaria 13083-970 - Campinas, SP Brazil - Caixa-Postal: 6109 (Brazil)

    2013-05-06

    In this study the Ca levels were determined in amateur runners blood at LABEX (Laboratorio de Bioquimica do Exercicio - UNICAMP, Brazil), using Neutron Activation Analyses (NAA) technique. The range established at rest (162 - 410 mgL{sup -1}) when compared with control group (51 - 439 mgL{sup -1}) suggests that there is a dependency of these limits in the function of the adopted physical training.

  1. Differences in Spatiotemporal Parameters Between Trained Runners and Untrained Participants.

    Science.gov (United States)

    Gómez-Molina, Josué; Ogueta-Alday, Ana; Stickley, Christopher; Cámara, Jesús; Cabrejas-Ugartondo, Jon; García-López, Juan

    2017-08-01

    Gómez-Molina, J, Ogueta-Alday, A, Stickley, C, Tobalina, JC, Cabrejas-Ugartondo, J, and García-López, J. Differences in spatiotemporal parameters between trained runners and untrained participants. J Strength Cond Res 31(8): 2169-2175, 2017-The aim of this study was to compare the spatiotemporal parameters of trained runners and untrained participants with the same foot strike pattern (rearfoot) during running at controlled speeds. Twenty-one participants were classified in 2 groups according to their training experience: Trained (n = 10, amateur runners with long distance training experience) and Untrained (n = 11, healthy untrained participants). Anthropometric variables were recorded, and the participants performed both a submaximal (between 9 and 15 km·h) and a graded exercise running test (from 6 km·h until exhaustion) on a treadmill. Physiological (V[Combining Dot Above]O2max, heart rate, running economy [RE], peak speed …) and biomechanical variables (contact and flight times, step rate, and length) were simultaneously registered. Trained runners showed higher step rate and shorter step length than the Untrained group at the same running speeds (between 4 and 7%, p ≤ 0.05) and at the same physiological intensities (between 7 and 11%, p ≤ 0.05). However, there were no differences in contact and flight times between groups. Significant differences (p ≤ 0.05) and large effect sizes (Cohen's d) between groups were found for body mass, sum of 6 skinfolds, V[Combining Dot Above]O2max, peak speed, and ventilatory threshold and respiratory compensation threshold speeds. The Trained group also showed a ∼7% better RE (ml·kg·km) than the Untrained group. In conclusion, adopting higher step rate and shorter step length may be an adaptive mechanism of the Trained group to reduce injury risk and possibly improve RE. However, contact and flight times were consistent regardless of training level.

  2. Evaluation nutrition of representative and recreational endurance runners

    OpenAIRE

    Jančová, Jana

    2017-01-01

    This bachelor thesis focused on the comparison nutrition of representative and recreational endurance runners. First part is theoretical. It deals with general concepts which are very important for understanding entire work. From general concepts it goes to specific sport nutrition focused on endurance. Practical part evaluates results, which were obtained from respondents. This is an analysis of four-day diet in two groups of people, followed by comparison and evaluation. Respondents from fi...

  3. Recreational road runners: injuries, training, demographics and physical characteristics

    Directory of Open Access Journals (Sweden)

    Joris Pazin

    2008-07-01

    Full Text Available http://dx.doi.org/10.5007/1980-0037.2008v10n3p277 The purpose of this study was to study recreational road runners in order to identify: their physical characteristics, demographics, running profile (training distance, frequency, duration, and experience and the prevalence of injuries and their association with age, running profile, and other sports practiced. Body mass, height (from which BMI was calculated and waist circumference were also measured. The sample of runners was composed of 115 men who participated in two events organized in Santa Catarina State, Brazil, in 2006: 22nd Maratona de Blumenau and 5th Desafio Praias e Trilhas (Florianópolis. The data were analyzed with descriptive statistics and the chi-square test to identify associations between injury prevalence and other variables (p<.05. The majority of the runners were aged between 18 and 50 years (63.2%, with 36.8% older than 50 years. In terms of educational level 24.3% had attended only elementary school, 35.4% high school, and 40% degree courses. Monthly family income (based on Brazilian minimum wage in Reais - R$ 380.00 varied between R$ 300 and R$ 999 for 23.3% of the runners, between R$ 1000 and R$ 2900 for 45.2%, and above R$ 3000 for 31.3% of them. Seventy two percent of them have been running regularly for more than 6 years, and 57% had received specialist guidance for running; 56.5% run more than 64 km/week. The injury prevalence for one year was 37.7%; BMI and waist circumference were within healthy limits. No associations were found between injury prevalence and other variables studied.

  4. Blood flow restriction exercise in sprinters and endurance runners.

    Science.gov (United States)

    Takada, Shingo; Okita, Koichi; Suga, Tadashi; Omokawa, Masashi; Morita, Noriteru; Horiuchi, Masahiro; Kadoguchi, Tomoyasu; Takahashi, Masashige; Hirabayashi, Kagami; Yokota, Takashi; Kinugawa, Shintaro; Tsutsui, Hiroyuki

    2012-03-01

    We demonstrated that blood flow restriction (BFR) remarkably enhances muscular metabolic stress in resistance exercise, although there is a wide range of individual differences in the responses. It is possible that these differences could be due to training status and muscular physiological characteristics. We investigated intramuscular metabolic responses during low-intensity resistance exercise with BFR between two different types of track athletes. Twelve age-matched male track athletes (sprinter group, n = 6; endurance runner group, n = 6) were recruited and performed unilateral plantarflexion (30 repetitions per minute). The exercise protocols were as follows: low-intensity exercise at 20% of one-repetition maximum (1RM) (L), high-intensity exercise at 65% 1RM without BFR (1.3 times of systolic blood pressure), L with BFR for 2 min (L-BFR), and prolonged exercise time in L-BFR for 3 min (prolonged BFR). Metabolic stress, defined as phosphocreatine and intramuscular pH decrease, and muscle fiber recruitment were evaluated using P magnetic resonance spectroscopy. Endurance runners showed higher peak oxygen uptake and lower muscle strength than sprinters. Phosphocreatine decreases in endurance runners during exercise with BFR protocols were significantly greater than those in sprinters (P sprinters (P < 0.05). The changes in intramuscular pH and the incidence of fast-twitch fiber recruitment did not show a statistical difference between the two groups. Phosphocreatine decreases in L-BFR were significantly correlated with peak oxygen uptake (P < 0.05). The effects of low-intensity resistance exercise with BFR are greater in endurance runners according to higher aerobic capacity.

  5. CERN runners on the podium for the Escalade race

    CERN Multimedia

    Caroline Duc

    2012-01-01

    For the last race of the season, CERN runners distinguished themselves by notching up third place in the inter-entreprises category of the Escalade, Geneva’s famous running race across the city.   Some of the runners from the CERN team. On Friday 30 November and Saturday 1 December, 35 runners from CERN braved the chilly Geneva weather to take part in the 35th Escalade race. With 81 teams competing in the race, the group representing the Laboratory took third place in the inter-entreprises category, behind the Hôpitaux Universitaires de Genève and the Panards Migros teams.   CERN’s Helenka Przysiezniak, Steffen Doebert and Camille Ruiz Llamas also distinguished themselves individually by finishing eighth, sixth and fourth in their respective categories and Patrick Villeton achieved a very good ranking in the DUC race on Friday evening and in the classic race on Saturday. Congratulations to everyone who participated and see you next ...

  6. Emotions and trait emotional intelligence among ultra-endurance runners.

    Science.gov (United States)

    Lane, Andrew M; Wilson, Mathew

    2011-07-01

    The aim of this study was to investigate relationships between trait emotional intelligence and emotional state changes over the course of an ultra-endurance foot race covering a route of approximately 175 miles (282 km) and held in set stages over six days. A repeated measures field design that sought to maintain ecological validity was used. Trait emotional intelligence was defined as a relatively stable concept that should predict adaptive emotional states experienced over the duration of the race and therefore associate with pleasant emotions during a 6-stage endurance event. Thirty-four runners completed a self-report measure of trait emotional intelligence before the event started. Participants reported emotional states before and after each of the six races. Repeated measures ANOVA results showed significant variations in emotions over time and a main effect for trait emotional intelligence. Runners high in self-report trait emotional intelligence also reported higher pleasant and lower unpleasant emotions than runners low in trait emotional intelligence. Findings lend support to the notion that trait emotional intelligence associates with adaptive psychological states, suggesting that it may be a key individual difference that explains why some athletes respond to repeated bouts of hard exercise better than others. Future research should test the effectiveness of interventions designed to enhance trait emotional intelligence and examine the attendant impact on emotional responses to intense exercise during multi-stage events. Copyright © 2011. Published by Elsevier Ltd.

  7. Hot Runner Mold Design of Fan Diverter Parts

    Science.gov (United States)

    Juan, D. J.; Cheng, Y. L.

    2017-09-01

    In this study, we discuss the case of plastic parts for the production of fan steering gear shaft parts injection molding, and use POM plastic steel to produce plastic parts from traditional cold runners. Because of the parts have a hole, which need side slide. The runner produce more waste after plastic parts injection make the runner waste account for the cost is relatively high, the cost of stock preparation is relatively increased when the product quantity demanded is great. After the crushing treatment of the waste, the backfill will affect the quality, and in the crushing process, the volume generated will make the operator to withstand up to 130 dB of noise. The actual test results show that the production cycle reduce 6.25%, while the production yield increase by about 5% and material costs reduced by 2% . It can be recovered within a year, not to mention the increase of the quality and reduction the noise on the staff of the benefit is impossible to estimate.

  8. Acute kinematics changes in marathon runners using different footwear.

    Science.gov (United States)

    Soares, Tania Socorro Amorim; Oliveira, Camila Fonseca de; Pizzuto, Federico; Manuel Garganta, Rui; Vila-Boas, João Paulo; Paiva, Mario Casimiro da Anunciação

    2017-06-22

    The effects of running with or without shoes on injury prevention have been extensively studied, and several investigations have assessed biomechanical differences between them. However, findings are not consensual and further insights on biomechanical load associated with differently shod or barefoot conditions may be needed. This study aimed to observe if habitually shod marathon runners show acute alterations when running barefoot or with minimalist shoes, and to determine whether the running kinematical adaptations of wearing minimalist shoes were similar to barefoot running. Twelve male marathon runners ran on the treadmill at their average marathon pace in different footwear conditions: habitual running shoes, minimalist shoes, and barefoot. High-resolution infrared cameras and visual 3D software were used to assess kinematic data. The following parameters were studied: foot strike angle, cycle time, stance time, normalized stride length, hip, knee, and ankle angular position at initial contact, and their respective range-of-motion (ROM) during stance phase. Contrary to the expectations, it was found that highly trained habitually shod elite marathon runners changed their lower limb kinematic pattern both when running barefoot or wearing minimalist shoes. Minimalist shoes showed a trend towards intermediate biomechanical effects between running with and without shoes.

  9. Kinematic Gait Patterns in Competitive and Recreational Runners.

    Science.gov (United States)

    Clermont, Christian A; Osis, Sean T; Phinyomark, Angkoon; Ferber, Reed

    2017-08-01

    Certain homogeneous running subgroups demonstrate distinct kinematic patterns in running; however, the running mechanics of competitive and recreational runners are not well understood. Therefore, the purpose of this study was to determine whether we could separate and classify competitive and recreational runners according to gait kinematics using multivariate analyses and a machine learning approach. Participants were allocated to the 'competitive' (n = 20) or 'recreational' group (n = 15) based on age, sex, and recent race performance. Three-dimensional (3D) kinematic data were collected during treadmill running at 2.7 m/s. A support vector machine (SVM) was used to determine if the groups were separable and classifiable based on kinematic time point variables as well as principal component (PC) scores. A cross-fold classification accuracy of 80% was found between groups using the top 5 ranked time point variables, and the groups could be separated with 100% cross-fold classification accuracy using the top 14 ranked PCs explaining 60.29% of the variance in the data. The features were primarily related to pelvic tilt, as well as knee flexion and ankle eversion in late stance. These results suggest that competitive and recreational runners have distinct, 'typical' running patterns that may help explain differences in injury mechanisms.

  10. An empirical study of race times in recreational endurance runners.

    Science.gov (United States)

    Vickers, Andrew J; Vertosick, Emily A

    2016-01-01

    Studies of endurance running have typically involved elite athletes, small sample sizes and measures that require special expertise or equipment. We examined factors associated with race performance and explored methods for race time prediction using information routinely available to a recreational runner. An Internet survey was used to collect data from recreational endurance runners (N = 2303). The cohort was split 2:1 into a training set and validation set to create models to predict race time. Sex, age, BMI and race training were associated with mean race velocity for all race distances. The difference in velocity between males and females decreased with increasing distance. Tempo runs were more strongly associated with velocity for shorter distances, while typical weekly training mileage and interval training had similar associations with velocity for all race distances. The commonly used Riegel formula for race time prediction was well-calibrated for races up to a half-marathon, but dramatically underestimated marathon time, giving times at least 10 min too fast for half of runners. We built two models to predict marathon time. The mean squared error for Riegel was 381 compared to 228 (model based on one prior race) and 208 (model based on two prior races). Our findings can be used to inform race training and to provide more accurate race time predictions for better pacing.

  11. Recommendations for healthy nutrition in female endurance runners: an update

    Directory of Open Access Journals (Sweden)

    Louise eDeldicque

    2015-05-01

    Full Text Available The purpose of this review is to present the basic principles of a healthy nutrition in female endurance runner enriched by the latest scientific recommendations. Female endurance runners are a specific population of athletes who need to take specifically care of daily nutrition due to the high load of training and the necessity to keep a rather low body mass. This paradoxical situation can create some nutritional imbalances and deficiencies. Female endurance athletes should pay attention to their total energy intake, which is often lower than their energy requirement. The minimal energy requirement has been set to 45kcal/kg fat free mass/day plus the amount of energy needed for physical activity. The usual recommended amount of 1.2-1.4g protein/kg/day has recently been questioned by new findings suggesting that 1.6g/kg/day would be more appropriate for female athletes. Although a bit less sensitive to carbohydrate loading than their male counterparts, female athletes can benefit from this nutritional strategy before a race if the amount of carbohydrates reaches 8g/kg/day and if their daily total energy intake is sufficient. A poor iron status is a common issue in female endurance runners but iron-enriched food as well as iron supplementation may help to counterbalance this poor status. Finally, they should also be aware that they may be at risk for low calcium and vitamin D levels.

  12. Assessment of Dissolved Oxygen Mitigation at Hydropower Dams Using an Integrated Hydrodynamic/Water Quality/Fish Growth Model

    Energy Technology Data Exchange (ETDEWEB)

    Bevelhimer, Mark S [ORNL; Coutant, Charles C [ORNL

    2006-07-01

    Dissolved oxygen (DO) in rivers is a common environmental problem associated with hydropower projects. Approximately 40% of all FERC-licensed projects have requirements to monitor and/or mitigate downstream DO conditions. Most forms of mitigation for increasing DO in dam tailwaters are fairly expensive. One area of research of the Department of Energy's Hydropower Program is the development of advanced turbines that improve downstream water quality and have other environmental benefits. There is great interest in being able to predict the benefits of these modifications prior to committing to the cost of new equipment. In the case of turbine replacement or modification, there is a need for methods that allow us to accurately extrapolate the benefits derived from one or two turbines with better design to the replacement or modification of all turbines at a site. The main objective of our study was to demonstrate a modeling approach that integrates the effects of flow and water quality dynamics with fish bioenergetics to predict DO mitigation effectiveness over long river segments downstream of hydropower dams. We were particularly interested in demonstrating the incremental value of including a fish growth model as a measure of biological response. The models applied are a suite of tools (RMS4 modeling system) originally developed by the Tennessee Valley Authority for simulating hydrodynamics (ADYN model), water quality (RQUAL model), and fish growth (FISH model) as influenced by DO, temperature, and available food base. We parameterized a model for a 26-mile reach of the Caney Fork River (Tennessee) below Center Hill Dam to assess how improvements in DO at the dam discharge would affect water quality and fish growth throughout the river. We simulated different types of mitigation (i.e., at the turbine and in the reservoir forebay) and different levels of improvement. The model application successfully demonstrates how a modeling approach like this one can be

  13. Small hydropower plants standardization, between myth and reality

    Science.gov (United States)

    Paraschivescu, A. V.; Ahmad-Rashid, K.; Popa, F.; Popa, B.

    2017-01-01

    Many providers for small hydropower plants equipment have tried to standardize the components and even the entire equipment. So called “compact turbines” were launched on the market, ensuring the pre-designed solution of the modular components, but usually with lower efficiency then turbines specially designed for a certain site. For civil works it is possible to standardize some components, such as the powerhouse, the surge tank or the headrace, but not the intake and the weir. Part of the hydropower plants can be standardized, but not the entire project, because there are a lot of variables that influence the design. Among these, the dimension, materials and design of the canal and the penstock are given by the hydrology, topography and the geology of the project’s area. This paper presents an attempt at standardization by using different heads and different installed flows. The case study is made on the Lukosi River from Tanzania, because there is a good hydrological database on power and energy calculation. For the powerhouse, pressure tower and intake dimensioning, the assumptions and materials considered cover all challenges that could appear in the geological and topographical structure of the project’s area (worst case, most expensive). The study has highlighted African climatologic and hydrological conditions and the adapting of current technology to these conditions.

  14. DOE/PSU Graduate Student Fellowship Program for Hydropower

    Energy Technology Data Exchange (ETDEWEB)

    Cimbala, John M. [Pennsylvania State Univ., State College, PA (United States)

    2014-03-30

    The primary objective of this project is to stimulate academic interest in the conventional hydropower field by supplying research support for at least eight individual Master of Science (MS) or Doctoral (PhD) level research projects, each consisting of a graduate student supervised by a faculty member. We have completed many of the individual student research projects: 2 PhD students have finished, and 4 are still working towards their PhD degree. 4 MS students have finished, and 2 are still working towards their MS degree, one of which is due to finish this April. In addition, 4 undergraduate student projects have been completed, and one is to be completed this April. These projects were supervised by 7 faculty members and an Advisory/Review Panel. Our students and faculty have presented their work at national or international conferences and have submitted several journal publications. Three of our graduate students (Keith Martin, Dan Leonard and Hosein Foroutan) have received HRF Fellowships during the course of this project. All of the remaining students are anticipated to be graduated by the end of Fall Semester 2014. All of the tasks for this project will have been completed once all the students have been graduated, although it will be another year or two until all the journal publications have been finalized based on the work performed as part of this DOE Hydropower project.

  15. Relative functional buffering capacity in 400-meter runners, long-distance runners and untrained individuals.

    Science.gov (United States)

    Röcker, K; Striegel, H; Freund, T; Dickhuth, H H

    1994-01-01

    Buffering is a factor which influences performance in short and middle-term endurance by compensating exercise acidosis. The aim of the study was to establish whether respiration parameters are a relative measure of buffering capacity and to study the influence of buffering on specific performance parameters. Three groups (each of ten subjects) with defined degrees of adaptation [untrained (UT), aerobic-trained (AeT) and elite 400-m runners (AnT) with a best time of 48.47 +/- 0.98 s] were examined in an incremental multi-stage test on the treadmill. Breath-by-breath gas analysis was performed using mass spectrometry and computer routines. Serum lactate concentrations were determined at each exercise level until subjective exhaustion. A value for the relative functional buffering capacity (relFB) was calculated using exercise metabolic parameters. Running speed at the lactate threshold was used as the starting point of buffering. The start of respiratory compensation of acidosis (RCP) was taken as the endpoint of buffering. RCP was determined at the point of decrease in end-tidal CO2 content (CO2-ET). RelFB was given in percent of buffering to running speed at RCP. Group AnT attained the same maximum performance data (maximum running speed, maximum rate of O2 consumption) as group AeT. However, these values were attained in group AnT with a significantly higher relFB (AnT: 31.0 +/- 3.2% vs. AeT: 15.7 +/- 3.9%, P < 0.0001), while a higher lactate threshold indicated a greater oxidative capacity in AeT (AeT: 3.07 +/- 0.26 m.s-1 vs. AnT: 2.68 +/- 0.22 m.s-1).(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Wind-Driven Ecological Flow Regimes Downstream from Hydropower Dams

    Science.gov (United States)

    Kern, J.; Characklis, G. W.

    2012-12-01

    Conventional hydropower can be turned on and off quicker and less expensively than thermal generation (coal, nuclear, or natural gas). These advantages enable hydropower utilities to respond to rapid fluctuations in energy supply and demand. More recently, a growing renewable energy sector has underlined the need for flexible generation capacity that can complement intermittent renewable resources such as wind power. While wind power entails lower variable costs than other types of generation, incorporating it into electric power systems can be problematic. Due to variable and unpredictable wind speeds, wind power is difficult to schedule and must be used when available. As a result, integrating large amounts of wind power into the grid may result in atypical, swiftly changing demand patterns for other forms of generation, placing a premium on sources that can be rapidly ramped up and down. Moreover, uncertainty in wind power forecasts will stipulate increased levels of 'reserve' generation capacity that can respond quickly if real-time wind supply is less than expected. These changes could create new hourly price dynamics for energy and reserves, altering the short-term financial signals that hydroelectric dam operators use to schedule water releases. Traditionally, hourly stream flow patterns below hydropower dams have corresponded in a very predictable manner to electricity demand, whose primary factors are weather (hourly temperature) and economic activity (workday hours). Wind power integration has the potential to yield more variable, less predictable flows at hydro dams, flows that at times could resemble reciprocal wind patterns. An existing body of research explores the impacts of standard, demand-following hydroelectric dams on downstream ecological flows; but weighing the benefits of increased reliance on wind power against further impacts to ecological flows may be a novel challenge for the environmental community. As a preliminary step in meeting this

  17. Musculoskeletal pain is prevalent among recreational runners who are about to compete: an observational study of 1049 runners.

    Science.gov (United States)

    Lopes, Alexandre Dias; Costa, Leonardo Oliveira Pena; Saragiotto, Bruno Tirotti; Yamato, Tiê Parma; Adami, Fernando; Verhagen, Evert

    2011-01-01

    What is the prevalence and nature of musculoskeletal pain in recreational runners immediately before a race? Cross-sectional survey. Adults intending to compete in a recreational running race between 5000 and 10 000 metres. Demographic data collected about the respondents included: age, gender, height, weight, duration of running experience, distance run per week, number of training sessions per week, training surface, and use of coaching. Respondents were asked if they had any pain. If pain was present, data were collected regarding its location, duration, current intensity, and behaviour. All data were self-reported. Data were collected from 1049 runners at five recreational races in São Paulo, Brazil. Of these respondents, 227 (22%) reported musculoskeletal pain before the race. Male respondents reported a greater running experience, a higher distance run per week, and a greater body mass index. Despite this, the prevalence of pain was 20% among the 796 male respondents and 27% among the 253 female respondents (RR 1.35, 95% CI 1.05 to 1.72). Where pain was present, it was typical of overuse injuries and its duration, intensity, and behaviour were similar between male and female respondents. The prevalence of musculoskeletal pain in recreational runners about to compete is substantial. Physiotherapists might be able to circumvent worsening of existing overuse injuries in this population with advice and preventive interventions. Copyright © 2011 Australian Physiotherapy Association. Published by .. All rights reserved.

  18. Plasma lipid and lipoprotein profile in elderly male long-distance runners.

    Science.gov (United States)

    Higuchi, M; Fuchi, T; Iwaoka, K; Yamakawa, K; Kobayashi, S; Tamai, T; Takai, H; Nakai, T

    1988-04-01

    The purpose of this study was to evaluate plasma lipid and lipoprotein profiles in 30 elderly male long-distance runners (aged 66 +/- 5 years, body fat 12 +/- 2%, mean +/- SD) by comparing them with 30 middle-aged untrained men (43 +/- 8 years, 17 +/- 3%), 30 middle-aged endurance-trained men (45 +/- 8 years, 12 +/- 2%) who were matched for training distance to the elderly runners, and 15 elderly sedentary persons (65 +/- 4 years, 16 +/- 4%). Both elderly and middle-aged runners averaged 43 km/week in the latest year. Maximal oxygen uptake in the elderly runners (48 +/- 5 ml/kg/min) was 60% higher than in age-matched untrained men, but 15% lower than in middle-aged runners. Plasma high-density lipoprotein cholesterol (HDLC) was significantly higher in the elderly runners than in their age-matched counterparts (77 vs. 59 mg/dl), but not different from the middle-aged runners. The middle-aged runners had lower plasma low-density lipoprotein cholesterol (LDLC) concentrations than their untrained counterparts (114 vs. 129 mg/dl), whereas LDLC level in the elderly runners was almost identical to that of the age-matched untrained men (127 vs. 119 mg/dl). Total cholesterol concentration in the elderly runners (219 mg/dl) was 11% higher than in the age-matched untrained men, whereas there was no difference between the middle-aged trained and untrained men. The remarkable reduction of the LDLC/HDLC ratio in the elderly runners, therefore, is attributable to the elevated HDLC rather than lowered LDLC compared with the age-matched sedentary men (1.7 vs. 2.2).(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Portfolio optimisation for hydropower producers that balances riverine ecosystem protection and producer needs

    Science.gov (United States)

    Yin, X. A.; Yang, Z. F.; Liu, C. L.

    2014-04-01

    In deregulated electricity markets, hydropower portfolio design has become an essential task for producers. The previous research on hydropower portfolio optimisation focused mainly on the maximisation of profits but did not take into account riverine ecosystem protection. Although profit maximisation is the major objective for producers in deregulated markets, protection of riverine ecosystems must be incorporated into the process of hydropower portfolio optimisation, especially against a background of increasing attention to environmental protection and stronger opposition to hydropower generation. This research seeks mainly to remind hydropower producers of the requirement of river protection when they design portfolios and help shift portfolio optimisation from economically oriented to ecologically friendly. We establish a framework to determine the optimal portfolio for a hydropower reservoir, accounting for both economic benefits and ecological needs. In this framework, the degree of natural flow regime alteration is adopted as a constraint on hydropower generation to protect riverine ecosystems, and the maximisation of mean annual revenue is set as the optimisation objective. The electricity volumes assigned in different electricity submarkets are optimised by the noisy genetic algorithm. The proposed framework is applied to China's Wangkuai Reservoir to test its effectiveness. The results show that the new framework could help to design eco-friendly portfolios that can ensure a planned profit and reduce alteration of the natural flow regime.

  20. Accelerating Sustainability by Hydropower Development in China: The Story of HydroLancang

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    2017-07-01

    Full Text Available Sustainable development is a shared responsibility. Accelerating sustainability of water–energy–people nexus and building a common awareness of issues pertaining to sustainable development are essential for any sort of success in this direction. Hydropower has been a useful sustainable energy for development, yet highly controversial. This paper reviews the overall situation of hydropower development and China’s energy reforms and policies, accompanied with a case study of hydropower development the Lancang River by the HydroLancang, aiming to illustrate the two opposite sides of hydropower development—economy and environment. The paper concludes with a neutral view of hydropower as the necessary facilitator for development. Water is a shared responsibility. Hydropower might not be the optimum solution to eliminate the tension between human demand of energy and finite natural resource and the rising pressure of climate change worldwide, but it serves well as an “Electricity Bridge” before better alternatives become available. This is a more balanced view of hydropower rather than two extreme viewpoints that present themselves: on the one hand, exaggerated claims of the human power to tame the wild river, and, on the other hand, the idealistic fantasy of preserving nature by abandoning all human activity.

  1. Methane Ebullition in Temperate Hydropower Reservoirs and Implications for US Policy on Greenhouse Gas Emissions

    Science.gov (United States)

    Miller, Benjamin L.; Arntzen, Evan V.; Goldman, Amy E.; Richmond, Marshall C.

    2017-10-01

    The United States is home to 2198 dams actively used for hydropower production. With the December 2015 consensus adoption of the United Nations Framework Convention on Climate Change Paris Agreement, it is important to accurately quantify anthropogenic greenhouse gas emissions. Methane ebullition, or methane bubbles originating from river or lake sediments, has been shown to account for nearly all methane emissions from tropical hydropower reservoirs to the atmosphere. However, distinct ebullitive methane fluxes have been studied in comparatively few temperate hydropower reservoirs globally. This study measures ebullitive and diffusive methane fluxes from two eastern Washington reservoirs, and synthesizes existing studies of methane ebullition in temperate, boreal, and tropical hydropower reservoirs. Ebullition comprises nearly all methane emissions (>97%) from this study's two eastern Washington hydropower reservoirs to the atmosphere. Summer methane ebullition from these reservoirs was higher than ebullition in six southeastern U.S. hydropower reservoirs, however it was similar to temperate reservoirs in other parts of the world. Our literature synthesis suggests that methane ebullition from temperate hydropower reservoirs can be seasonally elevated compared to tropical climates, however annual emissions are likely to be higher within tropical climates, emphasizing the possible range of methane ebullition fluxes and the need for the further study of temperate reservoirs. Possible future changes to the Intergovernmental Panel on Climate Change and UNFCCC guidelines for national greenhouse gas inventories highlights the need for accurate assessment of reservoir emissions.

  2. A GIS based assessment of hydropower potential in Hornád basin

    Directory of Open Access Journals (Sweden)

    �ofia Kuzevičová

    2013-12-01

    Full Text Available The issue of efficient use of hydropower, ones of the available renewable resources is currently in the process of sustainable development of each country, often addressing the issue. Incite multiple aspects. It is now seen just growing interest in exploiting the potential of hydropower. On the basis of active efforts are developed to map the total quantity of usability hydropower at basin level in Slovakia. GIS as a powerful and sophisticated tool for processing spatially localized information and offers support for renewable energy sources (not excluding the field of hydropower. Through the integration of spatial data allows assessing the real problems and thus contributing effectively to make rational decisions. Especially in the field of hydropower projects have GIS well founded importance. Of course is important to mention that the potential for hydroelectric power is useless without the operation of hydropower that converts water into electrical energy. For the needs of administrators of watercourses and operators of water systems, the proposed model can be an important tool for decision-making in relation to its implementation activities. Contribution to the design solutions for potential hydropower will address river basin Hornád.

  3. The Role of Hydropower in Climate Change Mitigation and Adaptation: A Review

    Directory of Open Access Journals (Sweden)

    Luis Berga

    2016-09-01

    Full Text Available Hydropower is a clean, renewable, and environmentally friendly source of energy. It produces 3930 (TW.h.a−1, and yields 16% of the world’s generated electricity and about 78% of renewable electricity generation (in 2015. Hydropower and climate change show a double relationship. On the one hand, as an important renewable energy resource, hydropower contributes significantly to the avoidance of greenhouse gas (GHG emissions and to the mitigation of global warming. On the other hand, climate change is likely to alter river discharge, impacting water availability and hydropower generation. Hydropower contributes significantly to the reduction of GHG emissions and to energy supply security. Compared with conventional coal power plants, hydropower prevents the emission of about 3 GT CO2 per year, which represents about 9% of global annual CO2 emissions. Hydropower projects may also have an enabling role beyond the electricity sector, as a financing instrument for multipurpose reservoirs and as an adaptive measure regarding the impacts of climate change on water resources, because regulated basins with large reservoir capacities are more resilient to water resource changes, less vulnerable to climate change, and act as a storage buffer against climate change. At the global level, the overall impact of climate change on existing hydropower generation may be expected to be small, or even slightly positive. However, there is the possibility of substantial variations across regions and even within countries. In conclusion, the general verdict on hydropower is that it is a cheap and mature technology that contributes significantly to climate change mitigation, and could play an important role in the climate change adaptation of water resource availability. However, careful attention is necessary to mitigate the substantial environmental and social costs. Roughly more than a terawatt of capacity could be added in upcoming decades.

  4. Dynamic Modeling of Adjustable-Speed Pumped Storage Hydropower Plant: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, E.; Singh, M.; Gevorgian, V.; Mohanpurkar, M.; Havsapian, R.; Koritarov, V.

    2015-04-06

    Hydropower is the largest producer of renewable energy in the U.S. More than 60% of the total renewable generation comes from hydropower. There is also approximately 22 GW of pumped storage hydropower (PSH). Conventional PSH uses a synchronous generator, and thus the rotational speed is constant at synchronous speed. This work details a hydrodynamic model and generator/power converter dynamic model. The optimization of the hydrodynamic model is executed by the hydro-turbine controller, and the electrical output real/reactive power is controlled by the power converter. All essential controllers to perform grid-interface functions and provide ancillary services are included in the model.

  5. Safety requirements to the operation of hydropower plants; Sicherheit beim Betrieb von Wasserkraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Lux, Reinhard [Berufsgenossenschaft Energie Textil Elektro Medienerzeugnisse (BG ETEM), Koeln (Germany)

    2011-07-01

    Employers have to take into account various safety and health requirements relating to the design, construction, operation and maintenance of hydropower plants. Especially the diversity of the hydropower plant components requires the consideration of different safety and health aspects. In 2011 the ''Fachausschuss Elektrotechnik'' (expert committee electro-technics) of the institution for statutory accident insurance and prevention presented a new ''BG-Information'' dealing with ''Safe methods operating hydropower plants''. The following article gives an introduction into the conception and the essential requirements of this new BG-Information. (orig.)

  6. DOE Hydropower Program biennial report 1990--1991 (with updated annotated bibliography)

    Energy Technology Data Exchange (ETDEWEB)

    Chappell, J.R.; Rinehart, B.N.; Sommers, G.L. (Idaho National Engineering Lab., Idaho Falls, ID (United States)); Sale, M.J. (Oak Ridge National Lab., TN (United States))

    1991-07-01

    This report summarizes the activities of the US Department of Energy's (DOE) Hydropower Program for fiscal years 1990 and 1991, and provides an annotated bibliography of research, engineering, operations, regulations, and costs of projects pertinent to hydropower development. The Hydropower Program is organized as follows: background (including Technology Development and Engineering Research and Development); Resource Assessment; National Energy Strategy; Technology Transfer; Environmental Research; and, the bibliography discusses reports written by both private and non-Federal Government sectors. Most reports are available from the National Technical Information Service. 5 figs., 2 tabs.

  7. DOE Hydropower Program biennial report 1992--1993 (with an updated annotated bibliography)

    Energy Technology Data Exchange (ETDEWEB)

    Cada, G.F.; Sale, M.J. [Oak Ridge National Lab., TN (United States); Francfort, J.E.; Rinehart, B.N.; Sommers, G.L. [EG and G Idaho, Inc., Idaho Falls, ID (United States)

    1993-07-01

    This report, the latest in a series of annual/biennial Hydropower Program reports sponsored by the US Department of Energy, summarizes the research and development and technology transfer activities of fiscal years 1992 and 1993. The report discusses the activities in the four areas of the hydropower program: Environmental research; resource assessment; research coat shared with industry; and technology transfer. The report also offers an annotated bibliography of reports pertinent to hydropower, written by persons in Federal and state agencies, cities, metropolitan water districts, irrigation companies, and public and independent utilities. Most reports are available from the National Technical Information Service.

  8. The use of hydropower in South Tyrol; Wasserkraftnutzung in Suedtirol. Ausgangsvoraussetzungen, Bedeutung und Akteure

    Energy Technology Data Exchange (ETDEWEB)

    Berger, W. [Orizzonti, Verona (Italy)

    2007-12-03

    The Autonomous Province of Bolzano in the north of Italy is richly endowed with water ressources, which provided an essential basis for industrial development in the last century. Even today electricity production, exceeding consumption figures of the Province, is almost entirely based on hydropower. At the main river Adige and its tributaries there are currently about 850 hydropower plants in operation. Nearly 85% of the installed power are owned by only four electric utilities. The Region Trentino-Alto Adige shows a higher capacity per inhabitant and per surface of electricity generation from hydropower than Austria, internationally renowned for her exploitation of this ressource. (orig.)

  9. DOE Hydropower Program biennial report 1994--1995 with an updated annotated bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Rinehart, B.N.; Francfort, J.E.; Sommers, G.L. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States); Cada, G.F.; Sale, M.J. [Oak Ridge National Lab., TN (United States)

    1995-05-01

    This report, the latest in a series of annual/biennial Hydropower Program reports sponsored by the US Department of Energy, summarizes the research and development and technology transfer activities of fiscal years 1994 and 1995. The report discusses the activities in the four areas of the hydropower program: Environmental Research; Resource Assessment; Research Cost-Shared with Industry; and Technology Transfer. The report also includes an annotated bibliography of reports pertinent to hydropower, written by the staff of the Idaho National Engineering Laboratory, Oak Ridge National Laboratory, Federal and state agencies, cities, metropolitan water districts, irrigation companies, and public and independent utilities. Most reports are available from the National Technical Information Service.

  10. Evaluation of the dynamic behavior of a Pelton runner based on strain gauge measurements

    Science.gov (United States)

    Mack, Reiner; Probst, Christian

    2016-11-01

    A reliable mechanical design of Pelton runners is very important in the layout of new installations and modernizations. Especially in horizontal machines, where the housing is not embedded into concrete, a rupture of a runner bucket can have severe consequences. Even if a crack in the runner is detected on time, the outage time that follows the malfunction of the runner is shortening the return of investment. It is a fact that stresses caused by the runner rotation and the jet forces are superposed by high frequent dynamic stresses. In case of resonance it even can be the dominating effect that is limiting the lifetime of a runner. Therefore a clear understanding of the dynamic mechanisms is essential for a safe runner design. This paper describes the evaluation of the dynamic behavior of a Pelton runner installed in a model turbine based on strain gauge measurements. Equipped with strain gauges at the root area of the buckets, the time responses of the strains under the influence of various operational parameters were measured. As a result basic theories for the jet bucket excitation were verified and the influence of the water mass was detected by evaluating the frequency shift in case of resonance. Furthermore, the influence of the individual bucket masses onto the dynamic behaviour for different mode shapes got measured.

  11. CFD Simulation and Optimization of Very Low Head Axial Flow Turbine Runner

    Directory of Open Access Journals (Sweden)

    Yohannis Mitiku Tobo

    2015-10-01

    Full Text Available The main objective of this work is Computational Fluid Dynamics (CFD modelling, simulation and optimization of very low head axial flow turbine runner  to be used to drive  a centrifugal pump of turbine-driven pump. The ultimate goal of the optimization is to produce a power of 1kW at head less than 1m from flowing  river to drive centrifugal pump using mechanical coupling (speed multiplier gear directly. Flow rate, blade numbers, turbine rotational speed, inlet angle are parameters used in CFD modeling,  simulation and design optimization of the turbine runner. The computed results show that power developed by a turbine runner increases with increasing flow rate. Pressure inside the turbine runner increases with flow rate but, runner efficiency increases for some flow rate and almost constant thereafter. Efficiency and power developed by a runner drops quickly if turbine speed increases due to higher pressure losses and conversion of pressure energy to kinetic energy inside the runner. Increasing blade number increases power developed but, efficiency does not increase always. Efficiency increases for some blade number and drops down due to the fact that  change in direction of the relative flow vector at the runner exit, which decreases the net rotational momentum and increases the axial flow velocity.

  12. Plasma LDH isozyme after 400-m sprinting in long-distance runners and untrained subjects.

    Science.gov (United States)

    Ohkuwa, T; Miyamura, M

    1986-01-01

    Plasma LDH activity and LDH isozyme following 400-m sprinting were determined in 8 long-distance runners and 7 untrained subjects. There is a significant correlation between the mean velocity of the 400-m sprint and LDH-5 or LDH-4+5 in the long-distance runners, but not in the untrained subjects.

  13. Differences in kinetic asymmetry between injured and noninjured novice runners : A prospective cohort study

    NARCIS (Netherlands)

    Bredeweg, S. W.; Buist, I.; Kluitenberg, B.

    Purpose: The purpose of this prospective study was to describe natural levels of asymmetry in running, compare levels of asymmetry between injured and noninjured novice runners and compare kinetic variables between the injured and noninjured lower limb within the novice runners with an injury.

  14. Yoga and psychophysiological determinants of cardiovascular health: comparing yoga practitioners, runners, and sedentary individuals.

    Science.gov (United States)

    Satin, Jillian R; Linden, Wolfgang; Millman, Roanne D

    2014-04-01

    The evidence of cardiovascular benefits of yoga is promising, but lacks demonstrations of specificity compared to other interventions. The present cross-sectional study examined cardiovascular health markers in long-term practitioners of yoga (yogis), runners, and sedentary individuals. We compared physiological, psychological, and lifestyle variables associated with cardiovascular health across groups. Yogis (n = 47) and runners (n = 46) showed favorable profiles compared to sedentary individuals (n = 52) on heart rate, heart rate variability, depression, perceived stress, and cigarette smoking. Runners and male yogis showed superior aerobic fitness compared to the sedentary group. Runners reported greater social support compared to other groups. Yogis demonstrated a lower respiration rate compared to sedentary individuals and were more likely to refrain from eating meat compared to other groups. Yogis and runners demonstrated several cardiovascular health advantages over sedentary individuals. Our findings raise the possibility that yoga may improve aerobic fitness in men but not women.

  15. Effects of foot orthoses on Achilles tendon load in recreational runners.

    Science.gov (United States)

    Sinclair, J; Isherwood, J; Taylor, P J

    2014-09-01

    Achilles tendon pathology is a frequently occurring musculoskeletal disorder in runners. Foot orthoses have been shown to reduce the symptoms of pain in runners but their mechanical effects are still not well understood. This study aimed to examine differences in Achilles tendon load when running with and without orthotic intervention. Twelve male runners ran at 4.0 m·s(-1). Ankle joint moments and Achilles tendon forces were compared when running with and without orthotics. The results indicate that running with foot orthotics was associated with significant reductions in Achilles tendon load compared to without orthotics. In addition to providing insight into the mechanical effects of orthotics in runners, the current investigation suggests that via reductions in Achilles tendon load, foot orthoses may serve to reduce the incidence of chronic Achilles tendon pathologies in runners. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Project SHARE Sustainable Hydropower in Alpine Rivers Ecosystems

    Science.gov (United States)

    Mammoliti Mochet, Andrea

    2010-05-01

    SHARE - Sustainable Hydropower in Alpine Rivers Ecosystems is a running project early approved and co funded by the European regional development fund in the context of the European Territorial Cooperation Alpine Space programme 2007 - 2013: the project is formally ongoing from August 2009 and it will end July 2012. Hydropower is the most important renewable resource for electricity production in alpine areas: it has advantages for the global CO2 balance but creates serious environmental impacts. RES-e Directives require renewable electricity enhance but, at the same time, the Water Framework Directive obliges member States to reach or maintain a water bodies "good" ecological status, intrinsically limiting the hydropower exploitation. Administrators daily face an increasing demand of water abstraction but lack reliable tools to rigorously evaluate their effects on mountain rivers and the social and economical outputs on longer time scale. The project intends to develop, test and promote a decision support system to merge on an unprejudiced base, river ecosystems and hydropower requirements. This approach will be led using existing scientific tools, adjustable to transnational, national and local normative and carried on by permanent panel of administrators and stakeholders. Scientific knowledge related to HP & river management will be "translated" by the communication tools and spent as a concrete added value to build a decision support system. In particular, the Multicriteria Analysis (MCA) will be applied to assess different management alternatives where a single-criterion approach (such as cost-benefit analysis) falls short, especially where environmental, technical, economic and social criteria can't be quantified by monetary values. All the existing monitoring databases will be used and harmonized with new information collected during the Pilot case studies. At the same time, all information collected will be available to end users and actors of related

  17. Outlook for hydropower in Latin America and the Caribbean

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Sierra, G. (OLADE, Quito (Ecuador))

    1993-02-01

    In the last two decades, the Latin America/Carribean region has become increasingly dependent on electricity to meet growing demands for energy. Hydropower is the prevailing source for meeting this need. Hydroelectric generation increased at an annual average rate of nearly 9% between 1971 and 1989. HYdro now provides more than two-thirds of total electric power generated in Latin America and the Caribbean. The only other predominant source used for electric generation is fossil fuels. In this region there are several trends developing. They include: developing more small hydro facilities, opportunities for sharing water resources, an interest in changing the approach to water use regulation, and possibilities for more participation by the private sector. Overall, hydro appears to have a favorable competitive position in the power industry in the Latin America/Caribbean region.

  18. Hydrograph variances over different timescales in hydropower production networks

    Science.gov (United States)

    Zmijewski, Nicholas; Wörman, Anders

    2016-08-01

    The operation of water reservoirs involves a spectrum of timescales based on the distribution of stream flow travel times between reservoirs, as well as the technical, environmental, and social constraints imposed on the operation. In this research, a hydrodynamically based description of the flow between hydropower stations was implemented to study the relative importance of wave diffusion on the spectrum of hydrograph variance in a regulated watershed. Using spectral decomposition of the effluence hydrograph of a watershed, an exact expression of the variance in the outflow response was derived, as a function of the trends of hydraulic and geomorphologic dispersion and management of production and reservoirs. We show that the power spectra of involved time-series follow nearly fractal patterns, which facilitates examination of the relative importance of wave diffusion and possible changes in production demand on the outflow spectrum. The exact spectral solution can also identify statistical bounds of future demand patterns due to limitations in storage capacity. The impact of the hydraulic description of the stream flow on the reservoir discharge was examined for a given power demand in River Dalälven, Sweden, as function of a stream flow Peclet number. The regulation of hydropower production on the River Dalälven generally increased the short-term variance in the effluence hydrograph, whereas wave diffusion decreased the short-term variance over periods of <1 week, depending on the Peclet number (Pe) of the stream reach. This implies that flow variance becomes more erratic (closer to white noise) as a result of current production objectives.

  19. Index of mechanical efficiency in competitive and recreational long distance runners.

    Science.gov (United States)

    McBride, Jeffrey M; Davis, Judith A; Alley, Jessica R; Knorr, Daniel P; Goodman, Courtney L; Snyder, James G; Battista, Rebecca A

    2015-01-01

    The purpose of this investigation was to compare external work and net energy expenditure during a bout of repetitive stretch-shortening cycles between competitive and recreational long-distance runners. Participants were divided into either competitive or recreational runners based on their maximal oxygen consumption and self-reported 1600 m times. The stretch-shortening cycle involved a repetitive hopping protocol on a force plate while measuring oxygen consumption and lactate accumulation for a total of 10 min. External work and net energy expenditure were calculated for 3 min after steady state was achieved and the ratio between these variables was utilised as an index of mechanical efficiency. Lower extremity stiffness was calculated during this interval as well. Net energy expenditure was significantly lower in competitive runners (152.6 ± 33.3 kJ) in comparison to recreational runners (200.6 ± 41.4 kJ) (P = 0.02) given similar amounts of external work performed in both groups (competitive runners = 65.6 ± 20.1 kJ, recreational runners = 68.8 ± 12.1 kJ) (P = 0.67). Index of mechanical efficiency was significantly different between competitive runners (43.2 ± 9.0%) and recreational runners (34.8 ± 5.3%) (P = 0.03). No significant differences were found in lower extremity stiffness (P = 0.64). Competitive distance runners can perform similar levels of external work with lower net energy expenditure and thus a higher index of mechanical efficiency during repetitive stretch-shortening cycles in comparison to recreational runners with similar values of lower extremity stiffness. This ability could possibly be due differences in muscle-tendon length changes, muscle pre-activation, cross-bridge potentiation and short-latency reflex responses as a result of training which should be considered for future investigation.

  20. COMPARISON OF SELECTED PHYSIOLOGICAL VARIABLES OF PLAYERS BELONGING TO VARIOUS DISTANCE RUNNERS

    Directory of Open Access Journals (Sweden)

    Satpal Yadav

    2009-12-01

    Full Text Available The purpose of the study was to compare the selected physiological variables namely; maximum oxygen consumption, vital capacity, resting heart rate and hemoglobin content among various distance runners. Thesubjects were selected from the male athlete’s of Gwalior district of various distance runners i.e. short, middle and long distance runners for this study. Ten (10 male athletes from each groups namely short, middle and long distance groups were selected as the subject for the study. Selected physiological variables such as maximum oxygen consumption, vital capacity, resting heart rate and hemoglobin content were presented to compare the players belonging to various distance runners namely short, middle and long distance. To see the significant difference of selected physiological variables among the players belonging to various distance runners the analysis of variance “F-ratio” was applied at.05 level of significance. For further analysis “Post-Hoc Test” (LSD Test was applied. The short distance runners had shown significantly different level of VO2 max (72.727 in comparison to middle distance (75.854 and long distance (77.094 runners. However, the middle and long distance runners had shown more or less same level of VO2. Further long distance runners had shown better efficiency of heart as its mean value (56.3 was lowest among all the three groups in relation to resting heartrate. On the other hand long, middle and short distance runners had shown more or less same vital capacity and hemoglobin content with a small range of variation.

  1. Reproductive system function in women cross-country runners.

    Science.gov (United States)

    Wakat, D K; Sweeney, K A; Rogol, A D

    1982-01-01

    Reproductive system function in women cross-country runners. Med. Sci. Sports Exercise, Vol. 14, No. 4, pp. 263-269, 1982. The incidence and etiology of altered menstrual cycle function in women engaged in endurance athletic activities were investigated by studying endocrine, anthropometric, and training parameters in 41 cross-country runners. The prevalence of altered menstrual cycle patterns was significantly higher in the subjects than in college-aged; 49% reported normal cycles and 51% were either oligomenorrheic (46%) or amenorrheic (5%). No significant differences between those reporting normal menstrual cycling (N) and those reporting oligo/amenorrhea (O/A) were found in the following areas: number of miles run/week, number of years of training, age when training began, sum of skinfold thicknesses, somatotype, or post-exercise levels of growth hormone, prolactin, or hematocrit. However, a difference (P less than 0.05) was found in the mean age of menarche (N = 12.9 +/- 0.3 yr; O/A = 14.3 +/- 0.5 yr). In addition, more O/A (68%) than N (42%) began training in the year of or prior to menarche. Evaluation of seven runners from one school who qualified for the national meet (1 amenorrheic, 5 oligomenorrheic, and 1 normal) revealed that the basal estrogen, progesterone, prolactin, and thyroid hormone levels were normal and that there were normal luteinizing hormone and follicle-stimulating hormone responses to synthetic gonadotropin-releasing hormone (GnRH). These data are consistent with an alteration of hypothalamic-pituitary-ovarian function above the level of the pituitary.

  2. Anthropometric characteristics of top-class Kenyan marathon runners.

    Science.gov (United States)

    Vernillo, G; Schena, F; Berardelli, C; Rosa, G; Galvani, C; Maggioni, M; Agnello, L; La Torre, A

    2013-08-01

    This study aims to: 1) describe the current anthropometric profiles of Kenyan marathon runners and 2) establish a set of reference values useful for future investigations on athlete selection, talent identification, and training programme development. The participants were 14 male top-class Kenyan marathon runners (mean [s] age 27.71 [3.75] yrs, height 171.21 [6.12] cm, body mass 57.71 [4.02] kg, marathon personal best 02h 07min 16s (01min 55s); training volume: 180-220 km·wk-1; high:low intensity training ratio: 1:2). The anthropometric profiles included the measurement of skinfolds, and segment lengths, breadths, and girths. To estimate body density (BD) multiple regression equations were calculated using the sum of 7-skinfolds method and then converted to percentage of body fat (%BF). The somatotype, somatotype dispersion mean (SDM), somatotype attitudinal mean (SAM), and height to weight ratio (HWR) as well as the skinfolds extremity to trunk ratio (E:T) were also calculated. The mean (s) of BD, %BF, SDM, SAM, HWR and E:T were 1.13 (0.02), 8.87 (0.07) %, 4.58 (3.62), 0.51 (0.09), 44.32 (1.06), and 0.36 (0.11), respectively. The mean (s) endomorphy, mesomorphy, and ectomorphy were 1.53 (0.32), 1.61 (1.81), and 3.86 (0.78), respectively. Top-class Kenyan marathon runners seem to have ectomorphy as dominant, with endomorphy and mesomorphy more than one-half unit lower. Despite population comparisons would be required to identify any connection between specific anthropometric dimensions, these reference data should be useful to practitioners and researchers, providing useful information for talent identification and development and for the assessment of training progression in marathon.

  3. Resting MAPK expression in chronically trained endurance runners.

    Science.gov (United States)

    Nicoll, Justin X; Fry, Andrew C; Galpin, Andrew J; Thomason, Donald B; Moore, Christopher A

    2017-10-01

    There is a paucity of research investigating the expression of mitogen-activated protein kinases (MAPK) in chronically trained (CT) athletes. Thus, it is unclear how MAPK may contribute to performance and muscle adaptation in CT subjects. The purpose of this study was to determine MAPK total protein, and phosphorylated expression of extracellular signal-regulated kinases 1 and 2 (ERK1/2), c-Jun N-terminal kinase (JNK), and p38-MAPK (p38) between untrained, and chronically trained runners. Tissue samples were analysed from sedentary (SED; n = 5) controls and chronically trained runners (CT; n = 5). Resting muscle biopsy samples were analysed for total-MAPK - and ratio of phosphorylated/total (p-MAPK) - ERK1/2, JNK, and p38-MAPK via western blotting. Mann-Whitney U tests and effect sizes were utilized to determine differences in total MAPK protein content and phosphorylation status between SED and CT subjects. There was no difference in total-MAPK expression between SED and CT (p > .05). p-p38-MAPK tended to be greater for CT compared to SED (p = .07). There were moderate effect sizes of decreased pERK/total-ERK (d = -0.69) and increased pJNK/total-JNK (d = 0.54) in CT compared to SED. There was a positive correlation between p-p38-MAPK/total-MAPK and the percentage of type I fibres (r = 0.73, p = .016). Contrary to previous studies, chronic endurance training does not greatly influence total MAPK protein expression in chronically trained runners. However, resting phosphorylation of p38-MAPK may contribute to enhanced oxidative metabolism at chronically trained levels. These alterations are likely involved in the different physiological adaptations that occur following long-term training or at highly competitive levels.

  4. Does polarized training improve performance in recreational runners?

    Science.gov (United States)

    Muñoz, Iker; Seiler, Stephen; Bautista, Javier; España, Javier; Larumbe, Eneko; Esteve-Lanao, Jonathan

    2014-03-01

    To quantify the impact of training-intensity distribution on 10K performance in recreational athletes. 30 endurance runners were randomly assigned to a training program emphasizing low-intensity, sub-ventilatory-threshold (VT), polarized endurance-training distribution (PET) or a moderately high-intensity (between-thresholds) endurance-training program (BThET). Before the study, the subjects performed a maximal exercise test to determine VT and respiratory-compensation threshold (RCT), which allowed training to be controlled based on heart rate during each training session over the 10-wk intervention period. Subjects performed a 10-km race on the same course before and after the intervention period. Training was quantified based on the cumulative time spent in 3 intensity zones: zone 1 (low intensity, RCT). The contribution of total training time in each zone was controlled to have more low-intensity training in PET (±77/3/20), whereas for BThET the distribution was higher in zone 2 and lower in zone 1 (±46/35/19). Both groups significantly improved their 10K time (39min18s ± 4min54s vs 37min19s ± 4min42s, P runners who actually performed the most PET (n = 6) and BThET (n = 16) distributions showed greater improvement in PET by 1.29 standardized Cohen effect-size units (90% CI 0.31-2.27, P = .038). Polarized training can stimulate greater training effects than between-thresholds training in recreational runners.

  5. PlateRunner: A Search Engine to Identify EMR Boilerplates.

    Science.gov (United States)

    Divita, Guy; Workman, T Elizabeth; Carter, Marjorie E; Redd, Andrew; Samore, Matthew H; Gundlapalli, Adi V

    2016-01-01

    Medical text contains boilerplated content, an artifact of pull-down forms from EMRs. Boilerplated content is the source of challenges for concept extraction on clinical text. This paper introduces PlateRunner, a search engine on boilerplates from the US Department of Veterans Affairs (VA) EMR. Boilerplates containing concepts should be identified and reviewed to recognize challenging formats, identify high yield document titles, and fine tune section zoning. This search engine has the capability to filter negated and asserted concepts, save and search query results. This tool can save queries, search results, and documents found for later analysis.

  6. Physiological and training characteristics of recreational marathon runners.

    Science.gov (United States)

    Gordon, Dan; Wightman, Sarah; Basevitch, Itay; Johnstone, James; Espejo-Sanchez, Carolina; Beckford, Chelsea; Boal, Mariette; Scruton, Adrian; Ferrandino, Mike; Merzbach, Viviane

    2017-01-01

    The aim of this study was to examine the physical and training characteristics of recreational marathon runners within finish time bandings (2.5-3 h, 3-3.5 h, 3.5-4 h, 4-4.5 h and >4.5 h). A total of 97 recreational marathon runners (age 42.4 ± 9.9 years; mass 69.2 ± 11.3 kg; stature 172.8 ± 9.1 cm), with a marathon finish time of 229.1 ± 48.7 min, of whom n = 34 were female and n = 63 were male, completed an incremental treadmill test for the determination of lactate threshold (LT1), lactate turn point (LT2) and running economy (RE). Following a 7-min recovery, they completed a test to volitional exhaustion starting at LT2 for the assessment of [Formula: see text]. In addition, all participants completed a questionnaire gathering information on their current training regimes exploring weekly distances, training frequencies, types of sessions, longest run in a week, with estimations of training speed, and load and volume derived from these data. Training frequency was shown to be significantly greater for the 2.5-3 h group compared to the 3.5-4 h runners (P 4.5 h group (P = 0.004), while distance per session (km·session-1) was significantly greater for the 2.5-3 h group (16.1 ± 4.2) compared to the 3.5-4 h group (15.5 ± 5.2; P = 0.01) and >4.5 h group (10.3 ± 2.6; P = 0.001). Race speed correlated with LT1 (r = 0.791), LT2 (r = 0.721) and distance per session (r = 0.563). The data highlight profound differences for key components of marathon running ([Formula: see text], LT1, LT2, RE and % [Formula: see text]) within a group of recreational runners with the discriminating training variables being training frequency and the absolute training speed.

  7. Predictor variables for marathon race time in recreational female runners.

    Science.gov (United States)

    Schmid, Wiebke; Knechtle, Beat; Knechtle, Patrizia; Barandun, Ursula; Rüst, Christoph Alexander; Rosemann, Thomas; Lepers, Romuald

    2012-06-01

    We intended to determine predictor variables of anthropometry and training for marathon race time in recreational female runners in order to predict marathon race time for future novice female runners. Anthropometric characteristics such as body mass, body height, body mass index, circumferences of limbs, thicknesses of skin-folds and body fat as well as training variables such as volume and speed in running training were related to marathon race time using bi- and multi-variate analysis in 29 female runners. The marathoners completed the marathon distance within 251 (26) min, running at a speed of 10.2 (1.1) km/h. Body mass (r=0.37), body mass index (r=0.46), the circumferences of thigh (r=0.51) and calf (r=0.41), the skin-fold thicknesses of front thigh (r=0.38) and of medial calf (r=0.40), the sum of eight skin-folds (r=0.44) and body fat percentage (r=0.41) were related to marathon race time. For the variables of training, maximal distance ran per week (r=- 0.38), number of running training sessions per week (r=- 0.46) and the speed of the training sessions (r= - 0.60) were related to marathon race time. In the multi-variate analysis, the circumference of calf (P=0.02) and the speed of the training sessions (P=0.0014) were related to marathon race time. Marathon race time might be partially (r(2)=0.50) predicted by the following equation: Race time (min)=184.4 + 5.0 x (circumference calf, cm) -11.9 x (speed in running during training, km/h) for recreational female marathoners. Variables of both anthropometry and training were related to marathon race time in recreational female marathoners and cannot be reduced to one single predictor variable. For practical applications, a low circumference of calf and a high running speed in training are associated with a fast marathon race time in recreational female runners.

  8. CFD modeling and simulation of a hydropower system in generating clean electricity from water flow

    National Research Council Canada - National Science Library

    Akinyemi, Oladapo S; Liu, Yucheng

    2015-01-01

    ...) modeling and simulation. Performance of paddle wheels in producing hydropower out of running water under different speeds was evaluated, and effects of side and bottom fins and paddle wheel shape on power generation were...

  9. Impact of Variation Orders on Time and Cost in Mega Hydropower Projects of Pakistan

    National Research Council Canada - National Science Library

    Hashim Hanif; Muhammad Bilal Khurshid; Søren Munch Lindhard; Zuhaib Aslam

    2016-01-01

    .... The results illustrate that errors and omissions in design, changes in scope and changes in design were among the three top contributing factors to VOs in hydropower projects that resulted in time and cost overruns...

  10. Development activities, challenges and prospects for the hydropower sector in Austria

    Science.gov (United States)

    Wagner, Beatrice; Hauer, Christoph; Habersack, Helmut

    2017-04-01

    This contribution intends to give an overview of hydropower development activities in Austria and deepen the knowledge on actual strategies and planning documents. Thereby, the focus is on a climate and energy policy based perspective, also analyzing economic trends at the hydropower sector due to energy market changes in the last years. This includes a comparison with other political strategies and programs dealing with hydropower exploitation based on selected countries. With respect to technology developments, a concise review on technological innovations, such as hydrokinetic energy conversion systems, and new constructive designs of conventional hydropower plants in Austria will be given. Moreover, potential impacts on environment and aquatic ecosystems are described. Finally, key challenges and prospects will be identified and discussed.

  11. Flow management for hydropower extirpates aquatic insects, undermining river food webs

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Two unique datasets were gathered to document whether flow management for hydropower affects the abundance and diversity of aquatic insect assemblages. The first...

  12. A Multi-Year Plan for Research, Development, and Prototype Testing of Standard Modular Hydropower Technology

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Brennan T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Welch, Tim [U.S. Department of Energy (DOE), Washington, DC (United States).Office of Energy Efficiency and Renewable Energy (EERE); Witt, Adam M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Stewart, Kevin M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lee, Kyutae [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); DeNeale, Scott T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bevelhimer, Mark S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Burress, Timothy A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pracheil, Brenda M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pries, Jason L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); O' Connor, Patrick W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Curd, Shelaine L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ekici, Kivanc [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Papanicolaou, Thanos [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Tsakiris, Achilleas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Kutz, Benjamin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Bishop, Norm [Knight Piesold, Denver, CO (United States); McKeown, Alisha [McKeown and Associates, Moberly, MO (United States); Rabon, Daniel [U.S. Department of Energy (DOE), Washington, DC (United States).Office of Energy Efficiency and Renewable Energy (EERE); Zimmerman, Gregory P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Uria Martinez, Rocio [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McManamay, Ryan A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-02-01

    The Multi-Year Plan for Research, Development, and Prototype Testing of Standard Modular Hydropower Technology (MYRP) presents a strategy for specifying, designing, testing, and demonstrating the efficacy of standard modular hydropower (SMH) as an environmentally compatible and cost-optimized renewable electricity generation technology. The MYRP provides the context, background, and vision for testing the SMH hypothesis: if standardization, modularity, and preservation of stream functionality become essential and fully realized features of hydropower technology, project design, and regulatory processes, they will enable previously unrealized levels of new project development with increased acceptance, reduced costs, increased predictability of outcomes, and increased value to stakeholders. To achieve success in this effort, the MYRP outlines a framework of stakeholder-validated criteria, models, design tools, testing facilities, and assessment protocols that will facilitate the development of next-generation hydropower technologies.

  13. Enhancing the resiliency of small hydropower projects: environmental function, modularity, and stakeholder elicitation as design priorities

    Energy Technology Data Exchange (ETDEWEB)

    Witt, Adam M [ORNL; Smith, Brennan T [ORNL

    2017-01-01

    Small hydropower plants supply reliable renewable energy to the grid, though few new plants have been developed in the Unites States over the past few decades due to complex environmental challenges and poor project economics. This paper describes the current landscape of small hydropower development, and introduces a new approach to facility design that co-optimizes the extraction of hydroelectric power from a stream with other important environmental functions such as fish, sediment, and recreational passage. The approach considers hydropower facilities as an integrated system of standardized interlocking modules, designed to sustain stream functions, generate power, and interface with the streambed. It is hypothesized that this modular eco-design approach, when guided by input from the broader small hydropower stakeholder community, can lead to cost savings across the facility, reduced licensing and approval timelines, and ultimately, to enhanced resiliency through improved environmental performance over the lifetime of the project.

  14. Small hydropower stations in Greece: The local people's attitudes in a mountainous prefecture

    Energy Technology Data Exchange (ETDEWEB)

    Malesios, Chrisovalantis [Department of Agricultural Development, Democritus University of Thrace, Pantazidou 193, 68200 Orestiada (Greece); Arabatzis, Garyfallos [Department of Forestry and Management of the Environment and Natural Resources, Democritus University of Thrace, Pantazidou 193, Orestiada (Greece)

    2010-12-15

    During the last years, it has become evident that operation of hydropower stations creates discussions and different views on the local communities. Especially, although the issue of operation of small hydropower (SHP) stations or plants is of considerable interest in Greece, almost no study has been conducted to investigate the current status of Greek citizens' attitudes towards utilization of the available hydropower potential through SHP. The present study, therefore, aims to examine in the prefecture of Ioannina, Greece, the local people's attitudes on operation of SHP stations in connection with the increased public interest for environmental and social dimensions of small hydropower stations, and to determine how these attitudes change with respect to various factors. (author)

  15. 75 FR 24937 - Northern Illinois Hydropower, LLC; Notice of Application Accepted for Filing and Soliciting...

    Science.gov (United States)

    2010-05-06

    ... Zdunich, Northern Illinois Hydropower, LLC, 801 Oakland Avenue, Joliet, IL 60435, (312) 320-1610. i. FERC... Road Dam and reservoir and would consist of: (1) A new 90-foot-by 118-foot concrete powerhouse between...

  16. Finding Multiple Optimal Solutions to Optimal Load Distribution Problem in Hydropower Plant

    Directory of Open Access Journals (Sweden)

    Xinhao Jiang

    2012-05-01

    Full Text Available Optimal load distribution (OLD among generator units of a hydropower plant is a vital task for hydropower generation scheduling and management. Traditional optimization methods for solving this problem focus on finding a single optimal solution. However, many practical constraints on hydropower plant operation are very difficult, if not impossible, to be modeled, and the optimal solution found by those models might be of limited practical uses. This motivates us to find multiple optimal solutions to the OLD problem, which can provide more flexible choices for decision-making. Based on a special dynamic programming model, we use a modified shortest path algorithm to produce multiple solutions to the problem. It is shown that multiple optimal solutions exist for the case study of China’s Geheyan hydropower plant, and they are valuable for assessing the stability of generator units, showing the potential of reducing occurrence times of units across vibration areas.

  17. Improving the sustainability of village hydropower in eastern and southern Africa

    CSIR Research Space (South Africa)

    Jonker Klunne, WJ

    2010-08-31

    Full Text Available Although small hydropower projects have been implemented in several countries on the continent, information on the current state of affairs is scattered, incomplete and sometimes even inconsistent. To a limited extent information is available...

  18. Fish-Friendly Hydropower Turbine Development & Deployment: Alden Turbine Preliminary Engineering and Model Testing

    Energy Technology Data Exchange (ETDEWEB)

    Foust, J. [Voith Hydro, Inc., York, PA (USA); Hecker, G. [Alden Research Laboratory, Inc., Holden, MA (USA); Li, S. [Alden Research Laboratory, Inc., Holden, MA (USA); Allen, G. [Alden Research Laboratory, Inc., Holden, MA (USA)

    2011-10-01

    The Alden turbine was developed through the U.S. Department of Energy's (DOE's) former Advanced Hydro Turbine Systems Program (1994-2006) and, more recently, through the Electric Power Research Institute (EPRI) and the DOE's Wind & Water Power Program. The primary goal of the engineering study described here was to provide a commercially competitive turbine design that would yield fish passage survival rates comparable to or better than the survival rates of bypassing or spilling flow. Although the turbine design was performed for site conditions corresponding to 92 ft (28 m) net head and a discharge of 1500 cfs (42.5 cms), the design can be modified for additional sites with differing operating conditions. During the turbine development, design modifications were identified for the spiral case, distributor (stay vanes and wicket gates), runner, and draft tube to improve turbine performance while maintaining features for high fish passage survival. Computational results for pressure change rates and shear within the runner passage were similar in the original and final turbine geometries, while predicted minimum pressures were higher for the final turbine. The final turbine geometry and resulting flow environments are expected to further enhance the fish passage characteristics of the turbine. Computational results for the final design were shown to improve turbine efficiencies by over 6% at the selected operating condition when compared to the original concept. Prior to the release of the hydraulic components for model fabrication, finite element analysis calculations were conducted for the stay vanes, wicket gates, and runner to verify that structural design criteria for stress and deflections were met. A physical model of the turbine was manufactured and tested with data collected for power and efficiency, cavitation limits, runaway speed, axial and radial thrust, pressure pulsations, and wicket gate torque. All parameters were observed to fall

  19. Turbine Aeration Design Software for Mitigating Adverse Environmental Impacts Resulting From Conventional Hydropower Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Gulliver, John S. [Univ. of Minnesota, Minneapolis, MN (United States)

    2015-03-01

    Conventional hydropower turbine aeration test-bed for computational routines and software tools for improving environmental mitigation technologies for conventional hydropower systems. In achieving this goal, we have partnered with Alstom, a global leader in energy technology development and United States power generation, with additional funding from the Initiative for Renewable Energy and the Environment (IREE) and the College of Science and Engineering (CSE) at the UMN

  20. 2014 Water Power Program Peer Review: Hydropower Technologies, Compiled Presentations (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    2014-02-01

    This document represents a collection of all presentations given during the EERE Wind and Water Power Program's 2014 Hydropower Peer Review. The purpose of the meeting was to evaluate DOE-funded hydropower and marine and hydrokinetic R&D projects for their contribution to the mission and goals of the Water Power Program and to assess progress made against stated objectives.

  1. Integrated management of the Blue Nile Basin in Ethiopia: Hydropower and irrigation modeling

    OpenAIRE

    Block, Paul J.

    2007-01-01

    "Ethiopia is at a critical crossroads with a large and increasing population, a depressed national economy, insufficient agricultural production, and a low number of developed energy sources. The upper Blue Nile basin harbors considerable untapped potential for irrigation and hydropower development and expansion. Numerous hydrologic models have been developed to assess hydropower and agricultural irrigation potential within the basin, yet often fail to adequately address critical aspects, inc...

  2. Optimization of cascade hydropower system operation by genetic algorithm to maximize clean energy output

    Directory of Open Access Journals (Sweden)

    Aida Tayebiyan

    2016-06-01

    Full Text Available Background: Several reservoir systems have been constructed for hydropower generation around the world. Hydropower offers an economical source of electricity with reduce carbon emissions. Therefore, it is such a clean and renewable source of energy. Reservoirs that generate hydropower are typically operated with the goal of maximizing energy revenue. Yet, reservoir systems are inefficiently operated and manage according to policies determined at the construction time. It is worth noting that with little enhancement in operation of reservoir system, there could be an increase in efficiency of the scheme for many consumers. Methods: This research develops simulation-optimization models that reflect discrete hedging policy (DHP to manage and operate hydropower reservoir system and analyse it in both single and multireservoir system. Accordingly, three operational models (2 single reservoir systems and 1 multi-reservoir system were constructed and optimized by genetic algorithm (GA. Maximizing the total power generation in horizontal time is chosen as an objective function in order to improve the functional efficiency in hydropower production with consideration to operational and physical limitations. The constructed models, which is a cascade hydropower reservoirs system have been tested and evaluated in the Cameron Highland and Batang Padang in Malaysia. Results: According to the given results, usage of DHP for hydropower reservoir system operation could increase the power generation output to nearly 13% in the studied reservoir system compared to present operating policy (TNB operation. This substantial increase in power production will enhance economic development. Moreover, the given results of single and multi-reservoir systems affirmed that hedging policy could manage the single system much better than operation of the multi-reservoir system. Conclusion: It can be summarized that DHP is an efficient and feasible policy, which could be used

  3. The Limits of Social Protection: The Case of Hydropower Dams and Indigenous Peoples' Land

    OpenAIRE

    Cooke, Majid Fadzilah; Nordensvard, Johan; Saat, Bin Gusni; Urban, Frauke; Siciliano, Giuseppina

    2017-01-01

    Hydropower dams have been criticized for their social and environmental implications. There have been attempts to create international social standards for hydropower dam projects but these standards have had limited impact. This article uses an extended environmental justice framework to make sense of the resettlement and compensation schemes for Indigenous peoples who were resettled for the construction of the Bakun dam in Borneo, East Malaysia. The article therefore analyses the social pro...

  4. Investments in hydropower from a political ecology perspective. Case study: Hidro Santa Cruz

    OpenAIRE

    Mazariegos Samayoa, Zoila Sofia Lorena

    2016-01-01

    This thesis intends to explore and analyse the discrepancies that exist between the accepted global narratives that promote investing in hydropower projects with the argument that it will bring development, economic growth and access to clean and affordable energy in developing countries, and the demands of the local communities where the hydropower projects are being built. By using a political ecology approach, the thesis aims to analyse the existing narratives and power relations in hydrop...

  5. Game theory competition analysis of reservoir water supply and hydropower generation

    Science.gov (United States)

    Lee, T.

    2013-12-01

    The total installed capacity of the power generation systems in Taiwan is about 41,000 MW. Hydropower is one of the most important renewable energy sources, with hydropower generation capacity of about 4,540 MW. The aim of this research is to analyze competition between water supply and hydropower generation in water-energy systems. The major relationships between water and energy systems include hydropower generation by water, energy consumption for water system operation, and water consumption for energy system. In this research, a game-theoretic Cournot model is formulated to simulate oligopolistic competition between water supply, hydropower generation, and co-fired power generation in water-energy systems. A Nash equilibrium of the competitive market is derived and solved by GAMS with PATH solver. In addition, a case study analyzing the competition among water supply and hydropower generation of De-ji and Ku-Kuan reservoirs, Taipower, Star Energy, and Star-Yuan power companies in central Taiwan is conducted.

  6. Disappearing rivers — The limits of environmental assessment for hydropower in India

    Energy Technology Data Exchange (ETDEWEB)

    Erlewein, Alexander, E-mail: erlewein@sai.uni-heidelberg.de

    2013-11-15

    The mountain rivers of the Indian Himalaya possess a vast potential for hydropower generation. After decades of comparatively modest development recent years have seen a major intensification in the construction of new hydropower dams. Although increasingly portrayed as a form of renewable energy generation, hydropower development may lead to extensive alterations of fluvial systems and conflicts with resource use patterns of local communities. To appraise and reduce adverse effects is the purpose of statutory Environmental Impact Assessments (EIA) and corresponding mitigation plans. However, in the light of ambitious policies for hydropower expansion conventional approaches of environmental assessment are increasingly challenged to keep up with the intensity and pace of development. This paper aims to explore the systemic limitations of environmental assessment for hydropower development in the Indian state of Himachal Pradesh. Based on a qualitative methodology involving interviews with environmental experts, document reviews and field observations the study suggests that the current practice of constraining EIAs to the project level fails to address the larger effects of extensive hydropower development. Furthermore, it is critically discussed as to what extent the concept of Strategic Environmental Assessment (SEA) might have the potential to overcome existing shortcomings.

  7. A multi-scale spatial approach to address environmental effects of small hydropower development.

    Science.gov (United States)

    McManamay, Ryan A; Samu, Nicole; Kao, Shih-Chieh; Bevelhimer, Mark S; Hetrick, Shelaine C

    2015-01-01

    Hydropower development continues to grow worldwide in developed and developing countries. While the ecological and physical responses to dam construction have been well documented, translating this information into planning for hydropower development is extremely difficult. Very few studies have conducted environmental assessments to guide site-specific or widespread hydropower development. Herein, we propose a spatial approach for estimating environmental effects of hydropower development at multiple scales, as opposed to individual site-by-site assessments (e.g., environmental impact assessment). Because the complex, process-driven effects of future hydropower development may be uncertain or, at best, limited by available information, we invested considerable effort in describing novel approaches to represent environmental concerns using spatial data and in developing the spatial footprint of hydropower infrastructure. We then use two case studies in the US, one at the scale of the conterminous US and another within two adjoining rivers basins, to examine how environmental concerns can be identified and related to areas of varying energy capacity. We use combinations of reserve-design planning and multi-metric ranking to visualize tradeoffs among environmental concerns and potential energy capacity. Spatial frameworks, like the one presented, are not meant to replace more in-depth environmental assessments, but to identify information gaps and measure the sustainability of multi-development scenarios as to inform policy decisions at the basin or national level. Most importantly, the approach should foster discussions among environmental scientists and stakeholders regarding solutions to optimize energy development and environmental sustainability.

  8. Multi-fidelity design optimization of Francis turbine runner blades

    Science.gov (United States)

    Bahrami, S.; Tribes, C.; von Fellenberg, S.; Vu, T. C.; Guibault, F.

    2014-03-01

    A robust multi-fidelity design algorithm has been developed, focusing to efficiently handle industrial hydraulic runner design considerations. The computational task is split between low- and high-fidelity phases in order to properly balance the CFD cost and required accuracy in different design stages. In the low-fidelity phase, a derivative-free optimization method employs an inviscid flow solver to obtain the major desired characteristics of a good design in a relatively fast iterative process. A limited number of candidates are selected among feasible optimization solutions by a newly developed filtering process. The main function of the filtering process is to select some promising candidates to be sent into the high-fidelity phase, which have significantly different geometries, and also are dominant in their own territories. The high-fidelity phase aims to accurately evaluate those promising candidates in order to select the one which is closest to design targets. A low-head runner case study has shown the ability of this methodology to identify an optimized blade through a relatively low computational effort, which is significantly different from the base geometry.

  9. Predictive Variables of Half-Marathon Performance for Male Runners.

    Science.gov (United States)

    Gómez-Molina, Josué; Ogueta-Alday, Ana; Camara, Jesus; Stickley, Christoper; Rodríguez-Marroyo, José A; García-López, Juan

    2017-06-01

    The aims of this study were to establish and validate various predictive equations of half-marathon performance. Seventy-eight half-marathon male runners participated in two different phases. Phase 1 (n = 48) was used to establish the equations for estimating half-marathon performance, and Phase 2 (n = 30) to validate these equations. Apart from half-marathon performance, training-related and anthropometric variables were recorded, and an incremental test on a treadmill was performed, in which physiological (VO2max, speed at the anaerobic threshold, peak speed) and biomechanical variables (contact and flight times, step length and step rate) were registered. In Phase 1, half-marathon performance could be predicted to 90.3% by variables related to training and anthropometry (Equation 1), 94.9% by physiological variables (Equation 2), 93.7% by biomechanical parameters (Equation 3) and 96.2% by a general equation (Equation 4). Using these equations, in Phase 2 the predicted time was significantly correlated with performance (r = 0.78, 0.92, 0.90 and 0.95, respectively). The proposed equations and their validation showed a high prediction of half-marathon performance in long distance male runners, considered from different approaches. Furthermore, they improved the prediction performance of previous studies, which makes them a highly practical application in the field of training and performance.

  10. Predictive Variables of Half-Marathon Performance for Male Runners

    Directory of Open Access Journals (Sweden)

    Josué Gómez-Molina, Ana Ogueta-Alday, Jesus Camara, Christoper Stickley, José A. Rodríguez-Marroyo, Juan García-López

    2017-06-01

    Full Text Available The aims of this study were to establish and validate various predictive equations of half-marathon performance. Seventy-eight half-marathon male runners participated in two different phases. Phase 1 (n = 48 was used to establish the equations for estimating half-marathon performance, and Phase 2 (n = 30 to validate these equations. Apart from half-marathon performance, training-related and anthropometric variables were recorded, and an incremental test on a treadmill was performed, in which physiological (VO2max, speed at the anaerobic threshold, peak speed and biomechanical variables (contact and flight times, step length and step rate were registered. In Phase 1, half-marathon performance could be predicted to 90.3% by variables related to training and anthropometry (Equation 1, 94.9% by physiological variables (Equation 2, 93.7% by biomechanical parameters (Equation 3 and 96.2% by a general equation (Equation 4. Using these equations, in Phase 2 the predicted time was significantly correlated with performance (r = 0.78, 0.92, 0.90 and 0.95, respectively. The proposed equations and their validation showed a high prediction of half-marathon performance in long distance male runners, considered from different approaches. Furthermore, they improved the prediction performance of previous studies, which makes them a highly practical application in the field of training and performance.

  11. Kinematic gait patterns in healthy runners: A hierarchical cluster analysis.

    Science.gov (United States)

    Phinyomark, Angkoon; Osis, Sean; Hettinga, Blayne A; Ferber, Reed

    2015-11-05

    Previous studies have demonstrated distinct clusters of gait patterns in both healthy and pathological groups, suggesting that different movement strategies may be represented. However, these studies have used discrete time point variables and usually focused on only one specific joint and plane of motion. Therefore, the first purpose of this study was to determine if running gait patterns for healthy subjects could be classified into homogeneous subgroups using three-dimensional kinematic data from the ankle, knee, and hip joints. The second purpose was to identify differences in joint kinematics between these groups. The third purpose was to investigate the practical implications of clustering healthy subjects by comparing these kinematics with runners experiencing patellofemoral pain (PFP). A principal component analysis (PCA) was used to reduce the dimensionality of the entire gait waveform data and then a hierarchical cluster analysis (HCA) determined group sets of similar gait patterns and homogeneous clusters. The results show two distinct running gait patterns were found with the main between-group differences occurring in frontal and sagittal plane knee angles (Pgait strategies. These results suggest care must be taken when selecting samples of subjects in order to investigate the pathomechanics of injured runners. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. A prospective study of iliotibial band strain in runners.

    Science.gov (United States)

    Hamill, Joseph; Miller, Ross; Noehren, Brian; Davis, Irene

    2008-10-01

    Iliotibial band syndrome is the leading cause of lateral knee pain in runners. It is thought that pain develops from strain on the iliotibial band due to friction of the iliotibial band sliding over the lateral femoral epicondyle. The purpose of this study was to investigate mechanical strain in the iliotibial band as a possible causative factor in the development of iliotibial band syndrome. From a large prospective study, female runners who incurred iliotibial band syndrome during the study were compared to a control group who incurred no injuries. Strain, strain rate and duration of impingement were determined from a musculoskeletal model of the lower extremity. The results indicated that the iliotibial band syndrome subjects exhibited greater strain throughout the support period, but particularly at midsupport compared to the control group. Strain rate was significantly greater in the iliotibial band syndrome group compared to the control group and was greater in the involved limb of the iliotibial band syndrome group compared to their contralateral limb. However, there were no differences in the duration of impingement between the groups. This study indicates that a major factor in the development of iliotibial band syndrome is strain rate. Therefore, we suggest that strain rate, rather than the magnitude of strain, may be a causative factor in developing iliotibial band syndrome. The effect size (>0.5) indicated that strain rate may be biologically significant in the etiology of iliotibial band syndrome.

  13. Practical management of iliotibial band friction syndrome in runners.

    Science.gov (United States)

    Fredericson, Michael; Weir, Adam

    2006-05-01

    This article outlines the practical management of iliotibial band friction syndrome (ITBFS) in running athletes. ITBFS is the most common cause of lateral knee pain in runners and is related to repetitive friction of the iliotibial band sliding over the lateral femoral epicondyle. Runners predisposed to this injury are typically in a phase of over training and often have underlying weakness of the hip abductor muscles. The diagnosis of ITBFS is clinical and is based on a thorough patient history and physical exam. In the acute phase, treatment includes activity modification, ice, nonsteroidal anti-inflammatory medication, and corticosteroid injection in cases of severe pain or swelling. During the subacute phase emphasis is on stretching of the iliotibial band and soft tissue therapy for any myofascial restrictions. The recovery phase focuses on a series of exercises to improve hip abductor strength and integrated movement patterns. The final return to running phase is begun with an every other day program, starting with easy sprints and avoidance of hill training with a gradual increase in frequency and intensity. In rare refractory cases that do not respond to conservative treatment, surgery can be considered.

  14. Recreational runners with patellofemoral pain exhibit elevated patella water content.

    Science.gov (United States)

    Ho, Kai-Yu; Hu, Houchun H; Colletti, Patrick M; Powers, Christopher M

    2014-09-01

    Increased bone water content resulting from repetitive patellofemoral joint overloading has been suggested to be a possible mechanism underlying patellofemoral pain (PFP). To date, it remains unknown whether persons with PFP exhibit elevated bone water content. The purpose of this study was to determine whether recreational runners with PFP exhibit elevated patella water content when compared to pain-free controls. Ten female recreational runners with a diagnosis of PFP (22 to 39years of age) and 10 gender, age, weight, height, and activity matched controls underwent chemical-shift-encoded water-fat magnetic resonance imaging (MRI) to quantify patella water content (i.e., water-signal fraction). Differences in bone water content of the total patella, lateral aspect of the patella, and medial aspect of the patella were compared between groups using independent t tests. Compared with the control group, the PFP group demonstrated significantly greater total patella bone water content (15.4±3.5% vs. 10.3±2.1%; P=0.001), lateral patella water content (17.2±4.2% vs. 11.5±2.5%; P=0.002), and medial patella water content (13.2±2.7% vs. 8.4±2.3%; Prunners with PFP is suggestive of venous engorgement and elevated extracellular fluid. In turn, this may lead to an increase in intraosseous pressure and pain. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. An improved method for evaluating ecological suitability of hydropower development by considering water footprint and transportation connectivity in Tibet, China.

    Science.gov (United States)

    Cui, Guannan; Wang, Xuan; Xu, Linyu; Zhang, Jin; Yu, Bing

    2014-01-01

    Ecological suitability evaluation for hydropower development is effective in locating the most suitable area for construction and emphasizes a clear direction for water resources governance. In this paper, water footprints and transportation connectivity were introduced to improve the existing ecological suitability evaluation application for hydropower development by revising the defects of the traditional indicator system. The following conclusions were reached. (1) Tibet was in a state of water use surplus; the prospect of further hydropower development is positive. (2) Chamdo, Lhasa and Nyingchi excelled in water use efficiency, and Ali was placed last. Nakchu was slightly superior to Ali, but it lagged behind the southern regions. Lhasa, Chamdo, Nyingchi, Xigaze and Shannan were suitable for hydropower development, which could further meet local needs and benefit other regions of China. (3) The evaluation results were in accordance with the actual eco-environmental conditions of the built hydropower projects, indicating that current hydropower development planning was basically reasonable.

  16. Defoliation of strawberry mother plants for the production of runner tips

    Directory of Open Access Journals (Sweden)

    Miriane Dal Picio

    2014-07-01

    Full Text Available The objective of this work was to determine the sink-source relationships and their effects on the number and growth of runner tips of 'Camino Real' strawberry stock plants. Three types of sources were evaluated: one defoliation at 96 days after planting (DAP, two defoliations at 50 and 96 DAP, and mother plants without defoliation. Four types of sink were accessed: runner tips collected weekly and monthly, four stolons with rooted runner tips in pots, and four freely-grown stolons. A completely randomized experimental design was used in a split-plot arrangement, with four replicates. The source types were placed in the plots, and sink types in the subplots. The number of runner tips, the crown diameter, and the dry matter mass were determined. Number and growth of tips were higher on plants without defoliation, and decreased 44.7% on twice-defoliated mother plants. The two-defoliation management did not reduce runner tip dry matter mass only on plants with rooted stolons, which produced runner tips 50% heavier. Defoliation of mother plants bearing rooting stolons can be used to reduce their growth, without reducing the emission and growth of runner tips.

  17. Determination and generalization of the effects of design parameters on Francis turbine runner performance

    Directory of Open Access Journals (Sweden)

    Ece Ayli

    2016-01-01

    Full Text Available The runner design is the most challenging part of the turbine design process. Several parameters determine the performance and cavitation characteristics of the runner: the metal angle (flow beta angle, the alpha angle, the blade beta angle, the runner inlet and outlet diameters, and the blade height. All of these geometrical parameters need to be optimized to ensure that the head, flow rate and power requirements of the system are met. A hydraulic designer has to allocate time to optimize these parameters and should be experienced in carrying out the iterative design process. In this article, the turbine runner parameters that affect the performance and cavitation characteristics of designed turbines are examined in detail. Furthermore, turbines are custom designed according to the properties of hydroelectric power plants; this makes the design process even more challenging, as the rotational speed, runner geometry, system head and flow rate vary for each turbine. The effects of the design parameters are examined for four different turbine runners specifically designed and used in actual power plants in order to obtain general results and generalizations applicable to turbine design aided by computational fluid dynamics (CFD. The flow behavior, flow angles, head losses, pressure distribution, and cavitation characteristics are computed, analyzed, and compared. To assist hydraulic designers, the general influences of these parameters on the performance of turbines are summarized and empirical formulations are derived for runner performance characterization.

  18. Stroke volume does not plateau during graded exercise in elite male distance runners.

    Science.gov (United States)

    Zhou, B; Conlee, R K; Jensen, R; Fellingham, G W; George, J D; Fisher, A G

    2001-11-01

    Stroke volume (SV) responses during graded treadmill exercise were studied in 1) elite male distance runners (N = 5), 2) male university distance runners (N = 10), and 3) male untrained university students (N = 10). Cardiac output (Q) and SV were determined by a modified acetylene rebreathing procedure. There were no differences in SV responses among the three groups during the transition from rest to light exercise (P > 0.05). However, the rates of change of SV during light to maximal exercise in untrained subjects (slope = -0.1544 mL x beat(-1)) and university distance runners (slope = 0.1041) did not change, whereas it dramatically increased (P runners (slope = 0.6734). Moreover, the elite distance runners showed a further slope increase in SV when heart rate was above 160 bpm, which resulted in an average maximal SV of 187 +/- 14 mL x beat(-1) compared with 145 +/- 8 and 128 +/- 14 mL x beat(-1) in the university runners and untrained students, respectively (P runners and untrained university students support the classic observation that SV plateaus at about 40% of maximal oxygen consumption despite increasing intensity of exercise. In contrast, stroke volume in the elite athletes does not plateau but increases continuously with increasing intensity of exercise over the full range of the incremental exercise test.

  19. Responses of distance runners and sprinters to exercise in a hot environment.

    Science.gov (United States)

    Irion, G L

    1987-10-01

    The responses of highly trained distance runners and track sprinters and age-matched untrained men were compared during bicycle ergometry in a 40 degree temperature-controlled environmental chamber. There were no differences among groups in rectal temperature following the 90 min exercise bout. Distance runners had a lower heart rate than either sprinters or untrained subjects. There was no difference in heart rate between sprinters and untrained subjects. Distance runners and sprinters had a much greater sweat rate than untrained subjects and dissipated a greater proportion of their total heat load by evaporation of sweat. Sprinters, however, had a lower sweat rate than distance runners in the hot environment and could only maintain as low a skin temperature as distance runners for 75 min of the 90 min session. Both aerobic training and anaerobic training confer some degree of protection from heat injury during exercise in a hot environment. However, sprinters have a higher heart rate and cannot sustain a low skin temperature as long as distance runners. Sprinters lost their advantage over untrained subjects in skin temperature after 75 min of exercise in a hot environment and did not have a lower heart rate than untrained subjects. Distance runners had a significantly lower heart rate and maintained a lower skin temperature than untrained subjects for the entire 90 min exercise bout.

  20. Relationship between foot strike pattern, running speed, and footwear condition in recreational distance runners.

    Science.gov (United States)

    Cheung, Roy T H; Wong, Rodney Y L; Chung, Tim K W; Choi, R T; Leung, Wendy W Y; Shek, Diana H Y

    2017-06-01

    Compared to competitive runners, recreational runners appear to be more prone to injuries, which have been associated with foot strike patterns. Surprisingly, only few studies had examined the foot strike patterns outside laboratories. Therefore, this study compared the foot strike patterns in recreational runners at outdoor tracks with previously reported data. We also investigated the relationship between foot strike pattern, speed, and footwear in this cohort. Among 434 recreational runners analysed, 89.6% of them landed with rearfoot strike (RFS). Only 6.9 and 3.5% landed with midfoot and forefoot, respectively. A significant shift towards non-RFS was observed in our cohort, when compared with previously reported data. When speed increased by 1 m/s, the odds of having forefoot strike and midfoot strike relative to RFS increased by 2.3 times and 2.6 times, respectively. Runners were 9.2 times more likely to run with a forefoot strike in minimalists compared to regular running shoes, although 70% of runners in minimalists continued to use a RFS. These findings suggest that foot strike pattern may differ across running conditions and runners should consider these factors in order to mitigate potential injury.

  1. Running economy and body composition between competitive and recreational level distance runners.

    Science.gov (United States)

    Mooses, Martin; Jürimäe, J; Mäestu, J; Mooses, K; Purge, P; Jürimäe, T

    2013-09-01

    The aim of the present study was to compare running economy between competitive and recreational level athletes at their individual ventilatory thresholds on track and to compare body composition parameters that are related to the individual running economy measured on track. We performed a cross-sectional analysis of a total 45 male runners classified as competitive runners (CR; n = 28) and recreational runners (RR; n = 17). All runners performed an incremental test on treadmill until voluntary exhaustion and at least 48 h later a 2 × 2000 m test at indoor track with intensities according to ventilatory threshold 1, ventilator threshold 2. During the running tests, athletes wore portable oxygen analyzer. Body composition was measured with Dual energy X-ray absorptiometry (DXA) method. Running economy at the first ventilatory threshold was not significantly related to any of the measured body composition values or leg mass ratios either in the competitive or in the recreational runners group. This study showed that there was no difference in the running economy between distance runners with different performance level when running on track, while there was a difference in the second ventilatory threshold speed in different groups of distance runners. Differences in running economy between competitive and recreational athletes cannot be explained by body composition and/or different leg mass ratios.

  2. INFLUENCE OF INJURY ON DYNAMIC POSTURAL CONTROL IN RUNNERS.

    Science.gov (United States)

    Meardon, Stacey; Klusendorf, Anna; Kernozek, Thomas

    2016-06-01

    Injury has been linked with altered postural control in active populations. The association between running injury and dynamic postural control has not been examined. The purpose of this study was to examine dynamic postural control in injured and uninjured runners using the Star Excursion Balance Test (SEBT), Time to Stabilization (TTS) of ground reaction forces following a single-leg landing, and postural stability indices reflecting the fluctuations in GRFs during single-leg landing and stabilization tasks (forward and lateral hop). It was hypothesized that dynamic postural control differences would exist between runners with a history of injury that interrupted training for ≥7 days (INJ) when compared to runners without injury (CON). Case-control study. Twenty-two INJ (14 F, 8 M; 23.7 ± 2.1 y; 22.3 ± 2.8 kg/m2; 29.5 ± 16.3 mi/wk) currently running > 50% pre-injury mileage without pain were compared with twenty-two matched CON (14F, 8M; 22.7 ± 1.2 y; 22.7 ± 2.7 kg/m2; 31.2 ± 19.6 mi/wk). INJ group was stratified by site of injury into two groups (Hip/Thigh/Knee and Lower Leg/Ankle/Foot) for secondary analysis. Leg length-normalized anterior, posterolateral, and posteromedial reach distances on the SEBT, medial/lateral and anterior/posterior ground reaction force TTS, directional postural stability indices, and a composite dynamic postural stability index (DPSI), were assessed using mixed model ANOVA (α=0.05) and effect sizes (d). No group X direction interaction or group differences were observed for the SEBT (p=0.51, 0.71) or TTS (p=0.83, 0.72) measures. A group X direction interaction was found for postural stability indices during the forward landing task (ppostural stability index (VPSI) (p=0.01 for both, d=0.80, 0.95) and DPSI (p=0.01, 0.02, d=0.75, 0.93) when compared to CON suggesting impaired balance control. A group X direction interaction was also found for postural stability indices during the lateral landing

  3. Physiological and training characteristics of recreational marathon runners

    Directory of Open Access Journals (Sweden)

    Gordon D

    2017-11-01

    Full Text Available Dan Gordon,1 Sarah Wightman,2 Itay Basevitch,1 James Johnstone,1 Carolina Espejo-Sanchez,1 Chelsea Beckford,1 Mariette Boal,1 Adrian Scruton,1 Mike Ferrandino,1 Viviane Merzbach1 1Cambridge Centre for Sport and Exercise Sciences, Anglia Ruskin University, 2The Flying Runner, Cambridge, UK Purpose: The aim of this study was to examine the physical and training characteristics of recreational marathon runners within finish time bandings (2.5–3 h, 3–3.5 h, 3.5–4 h, 4–4.5 h and >4.5 h.Materials and methods: A total of 97 recreational marathon runners (age 42.4 ± 9.9 years; mass 69.2 ± 11.3 kg; stature 172.8 ± 9.1 cm, with a marathon finish time of 229.1 ± 48.7 min, of whom n = 34 were female and n = 63 were male, completed an incremental treadmill test for the determination of lactate threshold (LT1, lactate turn point (LT2 and running economy (RE. Following a 7-min recovery, they completed a test to volitional exhaustion starting at LT2 for the assessment of VO2max. In addition, all participants completed a questionnaire gathering information on their current training regimes exploring weekly distances, training frequencies, types of sessions, longest run in a week, with estimations of training speed, and load and volume derived from these data.Results: Training frequency was shown to be significantly greater for the 2.5–3 h group compared to the 3.5–4 h runners (P < 0.001 and >4.5 h group (P = 0.004, while distance per session (km⋅session–1 was significantly greater for the 2.5–3 h group (16.1 ± 4.2 compared to the 3.5–4 h group (15.5 ± 5.2; P = 0.01 and >4.5 h group (10.3 ± 2.6; P = 0.001. Race speed correlated with LT1 (r = 0.791, LT2 (r = 0.721 and distance per session (r = 0.563.Conclusion: The data highlight profound differences for key components of marathon running (VO2max, LT1, LT2, RE and % VO2max within a group of recreational runners with the discriminating training variables being training

  4. Anthropometric and training characteristics of female marathon runners as determinants of distance running performance.

    Science.gov (United States)

    Bale, P; Rowell, S; Colley, E

    1985-01-01

    The purpose of this study was to determine how female marathon runners of varying standards differed in body composition and physique and in their training regimes, and secondly to develop predictors of distance running performance from the anthropometric and training variables. Female marathon runners (n = 36), all participants in a national 10 mile (16 km) road racing championship, were divided into three groups according to their best time for the 26.2 mile race. They were assessed for body composition and somatotype using anthropometric techniques and completed a questionnaire about their current training for the marathon. No difference was found between the groups of distance runners when measured for height, bone widths and circumferences. The three groups were found to have similar body weights of approximately 53 kg, a value which is much lower than the average for sedentary women, but which compares favourably with those from previous studies of female long distance runners. While all the runners had a lower per cent fat, as measured from skinfold thicknesses, than sedentary women, the elite runners were seen to have significantly lower values (P less than 0.05) than the other two groups. The difference in body fat was particularly reflected in the triceps skinfold value. There was also a tendency for the elite runners to be more ectomorphic and less endomorphic than the others. The better runners were seen, on the whole, to have been running longer, and to have more strenuous regimes, both in terms of intensity of training and distance run per week. Multiple regression and discriminant function analyses indicated that the number of training sessions per week and the number of years training were the best predictors of competitive performance at both 10 mile and marathon distances. They also indicated that a female long distance runner with a slim physique high in ectomorphy has the greatest potential for success.

  5. Medial and Lateral Heel Whips: Prevalence and Characteristics in Recreational Runners.

    Science.gov (United States)

    Souza, Richard B; Hatamiya, Nicolas; Martin, Carly; Aramaki, Andrew; Martinelli, Brian; Wong, Jamie; Luke, Anthony

    2015-08-01

    To investigate the prevalence and characteristics of recreational runners with medial and lateral heel whips. Observational cohort study. Clinical research laboratory. A total of 256 recreationally active runners and joggers participated. High-definition video was acquired from a posterior view while runners ran at a self-selected pace on a treadmill. Heel whips, defined as the medial or lateral rotation of the foot in the transverse plane during initial swing, were measured with Dartfish software. Subjects were stratified by direction (medial and lateral) and severity (W_5-10 = 5-10 degrees; W_10+ = >10 degrees) of heel whip. Body mass index and gender comparisons, as well as measurement reliability, also were explored. Mean heel whip angle across runners was 0.4 degrees (medial) with a standard deviation of 9.2 degrees. Of the 512 feet analyzed, 274 (54%) demonstrated a 5 degree whip or greater. There was a similar number of medial and lateral heel whips observed (27% each). Female runners were twice as likely to demonstrate a lateral heel whip of greater than 8.9 degrees. Overweight runners had more medially directed whips when compared with normal and underweight runners. More than half of the recreational runners studied were observed to have a medial or lateral heel whip of greater than 5 degrees. These data reveal the age, body mass index, and gender distribution of recreational runners with and without heel whips. Copyright © 2015 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  6. The effects of plantar fasciitis and pain on plantar pressure distribution of recreational runners.

    Science.gov (United States)

    Ribeiro, Ana Paula; Trombini-Souza, Francis; Tessutti, Vitor D; Lima, Fernanda R; João, Sílvia M A; Sacco, Isabel C N

    2011-02-01

    Plantar fasciitis is the third most frequent injury in runners. Despite its high prevalence, its pathogenesis remains inconclusive. The literature reports overload as the basic mechanism for its development. However, the way that these plantar loads are distributed on the foot surface of runners with plantar fasciitis and the effects of pain on this mechanical factor has not yet been investigated. Therefore, the aim of this study was to evaluate and compare the plantar pressure distributions during running in runners with symptom or history of plantar fasciitis and runners without the disease. Forty-five recreational runners with plantar fasciitis (30 symptomatic and 15 with previous history of the disease) and 60 runners without plantar fasciitis (control group) were evaluated. Pain was assessed by a visual analogue scale. All runners were evaluated by means of the Pedar system insoles during running forty meters at a speed of 12(5%) km/h, using standard sport footwear. Two-way ANOVAS were employed to investigate the main and interaction effects between groups and plantar areas. No interaction effects were found for any of the investigated variables: peak pressure (P = 0.61), contact area (P = 0.38), contact time (P = 0.91), and the pressure-time integral (P = 0.50). These findings indicated that the patterns of plantar pressure distribution were not affected in recreational runners with plantar fasciitis when compared to control runners. Pain also did not interfere with the dynamic patterns of the plantar pressure distributions. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. The morphology of foot soft tissues is associated with running shoe type in healthy recreational runners.

    Science.gov (United States)

    Zhang, Xianyi; Delabastita, Tijs; Lissens, Joselien; De Beenhouwer, Floor; Vanwanseele, Benedicte

    2017-11-22

    To determine the differences in the morphology of foot soft tissues between runners using different types of running shoes. Cross-sectional study. Thirty-eight recreational runners were divided into four groups based on running shoe type, namely, neutral shoes, motion control shoes, minimalistic shoes and neutral shoes with custom-made insoles. An arch height index and a relative arch deformation index were calculated for each participant. An ultrasound device was used to measure the cross-sectional area and/or the thickness of selected intrinsic foot muscles (abductor hallucis, flexor hallucis brevis and flexor digitorum brevis) and extrinsic foot muscles (flexor digitorum longus, tibialis anterior and the peroneus muscles), and the thickness of the plantar fascia, Achilles tendon and heel pad. Recreational runners using minimalistic shoes demonstrated stiffer foot arches than those using neutral shoes. Among the selected foot muscles, only abductor hallucis showed a significant morphological difference between shoe groups. Runners using minimalistic shoes had the thickest abductor hallucis. The minimalistic shoe runners also showed a thinner proximal plantar fascia and a thicker Achilles tendon than other runners. Insole runners had a thinner heel pad than neutral shoe runners. This study suggests that the morphology of foot soft tissues is associated with running shoe type in recreational runners. A sudden change in running shoe type without adjusting training volume should be undertaken with caution, since it may take time for foot soft tissues to adapt to a new shoe condition. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  8. Lower limb dynamics vary in shod runners who acutely transition to barefoot running.

    Science.gov (United States)

    Hashish, Rami; Samarawickrame, Sachithra D; Powers, Christopher M; Salem, George J

    2016-01-25

    Relative to traditional shod rear-foot strike (RFS) running, habituated barefoot running is associated with a forefoot-strike (FFS) and lower loading rates. Accordingly, barefoot running has been purported to reduce lower-extremity injury risk. Investigations, however, indicate that novice barefoot runners may not innately adopt a FFS. Therefore, the purpose of this study was to examine lower-extremity dynamics of habitually shod runners who acutely transition to barefoot running. 22 recreational RFS runners were included in this investigation. This laboratory controlled study consisted of two visits one-week apart, examining habitually shod, then novice barefoot running. Foot-strike patterns and loading rates were determined using motion analysis and force plates, and joint energy absorption was calculated using inverse dynamics. Of the 22 runners, 8 maintained a RFS, 9 adopted a MFS, and 5 adopted a FFS during novice barefoot running. All runners demonstrated a reduction in knee energy absorption when running barefoot; MFS and FFS runners also demonstrated a significant increase in ankle energy absorption. Runners who maintained a RFS presented with loading rates significantly higher than traditional shoe running, whereas FFS runners demonstrated a significant reduction in loading rate. Mid-foot strikers did not demonstrate a significant change in loading rate. These results indicate that habitually shod RFS runners demonstrate a variety of foot-strike and lower-extremity dynamic responses during the acute transition to barefoot running. Accordingly, explicit instruction regarding foot-strike patterns may be necessary if transitioning to barefoot. Long-term prospective studies are required in order to determine the influence of FFS barefoot running on injury rates. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Energy Recovery Hydropower: Prospects for Off-Setting Electricity Costs for Agricultural, Municipal, and Industrial Water Providers and Users; July 2017 - September 2017

    Energy Technology Data Exchange (ETDEWEB)

    Levine, Aaron L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Curtis, Taylor L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Johnson, Kurt [Telluride Energy; Telluride, CO (United States)

    2018-01-11

    Energy recovery hydropower is one of the most cost-effective types of new hydropower development because it is constructed utilizing existing infrastructure, and it is typically able to complete Federal Energy Regulatory Commission (FERC) review in 60 days. Recent changes in federal and state policy have supported energy recovery hydropower. In addition, some states have developed programs and policies to support energy recovery hydropower, including resource assessments, regulatory streamlining initiatives, and grant and loan programs to reduce project development costs. This report examines current federal and state policy drivers for energy recovery hydropower, reviews market trends, and looks ahead at future federal resource assessments and hydropower reform legislation.

  10. Defoliation of strawberry mother plants for the production of runner tips

    OpenAIRE

    Miriane Dal Picio; Jerônimo Luiz Andriolo; Francieli Lima Cardoso; Maíne Alessandra Lerner; Jéssica Maronez de Souza

    2014-01-01

    The objective of this work was to determine the sink-source relationships and their effects on the number and growth of runner tips of 'Camino Real' strawberry stock plants. Three types of sources were evaluated: one defoliation at 96 days after planting (DAP), two defoliations at 50 and 96 DAP, and mother plants without defoliation. Four types of sink were accessed: runner tips collected weekly and monthly, four stolons with rooted runner tips in pots, and four freely-grown stolons. A comple...

  11. The Interconnectedness of Diet Choice and Distance Running: Results of the Research Understanding the NutritioN of Endurance Runners (RUNNER) Study.

    Science.gov (United States)

    Turner-McGrievy, Gabrielle M; Moore, Wendy J; Barr-Anderson, Daheia

    2015-10-19

    This study examined differences in diet, particularly vegetarian and vegan, among ultramarathon and other long distance runners. Participants who had completed a half- (HALF), full- (FULL), or ultramarathon (ULTRA) in the past 12 months were recruited to complete an online survey assessing current diet, reason for diet, and other dietary behaviors. A total of 422 participants completed the survey (n=125 ULTRA, n=152 FULL, n=145 HALF). More ULTRA participants were men (63%) (vs. FULL (37%) and HALF (23%)) and ULTRA participants reported significantly more years of running (16.2 ± 13.6) than FULL (12.1 ± 11.1, Pvegan/vegetarian diet than HALF and FULL marathoners combined (B=1.94, 95% CI=1.08, 3.48) and reported following their current diet longer (13.7±15.3 years) than HALF participants (8.6±12.1 years, P=0.01). ULTRA participants more commonly cited environmental concerns whereas HALF and FULL participants cited weight loss or maintenance as a reason for following their current diet. There was no difference in diet quality between ULTRA and other runners but vegan and vegetarian runners had higher diet quality scores than non-vegetarian runners (Pdiet, and diet choice and can help guide nutrition, exercise, and psychology professionals who are working with distance runners.

  12. Rogun – Hydropower Generating Controversy in Central Asia

    Directory of Open Access Journals (Sweden)

    Lea Melnikovová

    2014-01-01

    Full Text Available The aim of this paper is to analyse the current conflict between Uzbekistan and Tajikistan over shared water resources, and propose an adequate solution. The tensions between the two countries are associated with the completion of a huge dam on a river on the Tajik territory. Such construction may have a negative impact on Uzbekistan’s irrigation needs since it may restrict inflow to the Amudarya River which is Uzbekistan’s key water resource. While Tajikistan intends to use water for hydropower, Uzbekistan needs water mainly for its cotton fields. This paper analyses the background, benefits and risks of the dam, roots of the tension, and suggests methods of resolving them. Based on the current dispute, the problem of shared water resources is generalized, discussed and two complementary approaches are presented. The international water law offers a set of guidelines applicable on transboundary water conflicts; the significance of the 1997 UN Convention concerning the law of the non-navigational uses of international watercourses is emphasized. Another instrument to grasp this problem is the game theory. The water allocation problem can be described using the Nash bargaining solution. This paper demonstrates that both approaches can contribute to resolving existing disputes over shared water resources.

  13. Return to Competition in a Chronic Low Back Pain Runner: Beyond a Therapeutic Exercise Approach, a Case Report.

    Science.gov (United States)

    Veneziani, Sergio; Doria, Christian; Falciati, Luca; Castelli, Claudio Carlo; Illic, Giorgio Fanò

    2014-09-23

    Chronic low back pain (CLBP) is a disabling condition affecting both quality of life and performance in athletes. Several approaches have been proposed in the field of physiotherapy, manual therapy, physical exercise and counseling. None apparently is outdoing the other with the exception of trunk stability exercises in specific conditions. The present paper describes a clinical success in managing a CLBP runner affected by MRI documented disk herniation via dietary change. Dietary changes allowed our patient that had failed with previous standard therapeutic approaches, to regain an optimal pain-free condition. We advance the hypothesis that a visceral-autonomic concomitant or primary disturbance possibly generating mild gastrointestinal discomfort in CLBP patients should be ruled out as a possible cause of pain and disability at the somato-motor level.

  14. Gastrointestinal complaints in runners are not due to small intestinal bacterial overgrowth

    Directory of Open Access Journals (Sweden)

    Bärtsch Peter

    2011-07-01

    Full Text Available Abstract Background Gastrointestinal complaints are common among long distance runners. We hypothesised that small intestinal bacterial overgrowth (SIBO is present in long distance runners frequently afflicted with gastrointestinal complaints. Findings Seven long distance runners (5 female, mean age 29.1 years with gastrointestinal complaints during and immediately after exercise without known gastrointestinal diseases performed Glucose hydrogen breath tests for detection of SIBO one week after a lactose hydrogen breath test checking for lactose intolerance. The most frequent symptoms were diarrhea (5/7, 71% and flatulence (6/7, 86%. The study was conducted at a laboratory. In none of the subjects a pathological hydrogen production was observed after the intake of glucose. Only in one athlete a pathological hydrogen production was measured after the intake of lactose suggesting lactose intolerance. Conclusions Gastrointestinal disorders in the examined long distance runners were not associated with small intestinal bacterial overgrowth.

  15. Bronchial epithelial damage after a half-marathon in nonasthmatic amateur runners

    National Research Council Canada - National Science Library

    Chimenti, Laura; Morici, Giuseppe; Paternò, Alessandra; Santagata, Roberta; Bonanno, Anna; Profita, Mirella; Riccobono, Loredana; Bellia, Vincenzo; Bonsignore, Maria R

    2010-01-01

    High neutrophil counts in induced sputum have been found in nonasthmatic amateur runners at rest and after a marathon, but the pathogenesis of airway neutrophilia in athletes is still poorly understood...

  16. Achilles tendinopathy in amateur runners: role of adiposity (Tendinopathies and obesity)

    OpenAIRE

    Abate, Michele; Oliva, Francesco; Schiavone, Cosima; Salini, Vincenzo

    2012-01-01

    Obesity is an important risk factor for Achilles tendinopathy, and running is usually carried out to reduce excess body weight. Aim of this study was to evaluate the prevalence of Achilles tendinopathy in young over-weight amateur runners.

  17. Differences in kinetic variables between injured and noninjured novice runners : A prospective cohort study

    NARCIS (Netherlands)

    Bredeweg, Steef W.; Kluitenberg, Bas; Bessem, Bram; Buist, Ida

    Objectives: This prospective study examined differences in kinetic variables between injured and noninjured novice female and male runners and their potential contribution to RRIs. Design: A prospective cohort study. Methods: At baseline vertical ground reaction forces were assessed with an

  18. Le controfigure di Dio. Da Blade Runner ad Avatar

    Directory of Open Access Journals (Sweden)

    Nicoletta Vallorani

    2011-06-01

    Full Text Available The issue of the relationship between the creator and his/her creature has been often dealt with  in dystopia and science fiction films, and in recent times it has taken on a specific flavor, less related to the implications of science and more connected to a symbolic dimension that goes  back to the Bible as a fruitful reservoir of myths and archetypes. The Biblical parable of the creation  in particular flows into narratives recalling familiar names and places, but deeply revising the  creator/creature relationship, that is unfolded through the poetic unacceptability of death in Blade  Runner (1982 and the possibility of a new life in a new body dwelling in the fictional Eden of Avatar (2010.

  19. Scenario Analysis on Global Hydropower Development Paths and Their Contribution to GHG Mitigation Utilizing a Dynamic CGE Model

    Science.gov (United States)

    Qian, Z.; Hanasaki, N.; Fujimori, S.; Masaki, Y.; Hijioka, Y.

    2015-12-01

    Currently, hydropower accounts for 16% of the worldwide electricity power supply and 86% of the total renewable electricity energy source due to its low cost, low greenhouse gas (GHG) emission, and relatively high reliability. It is well known that the global hydropower has not yet been fully developed, but the future paths of development and corresponding contribution to GHG mitigation in each region combined with socioeconomic activities are less known. Here we investigated following three questions. How much will hydropower generation increase in the future? Will hydropower generation reach the economically exploitable capability (EEC)? If this will be the case, when and where will it occur? How much GHG emission will be reduced by adding new hydropower? In order to address these questions, we used the AIM/CGE model, a dynamic computable general equilibrium model to quantify the global hydropower development paths and corresponding GHG mitigation contribution for 17 regions in the world associated with a socio-economic scenario termed SSP2. We compared two scenarios with different assumptions on EEC. One is BAU which takes EEC from the report of "World Energy Resources", the other is FIX_BAU which fix EEC at the current hydropower generation amount throughout the research period (2005-2100) or no additional installation of hydropower plants. The comparison between two scenarios indicated that promoting hydropower development contributed to GHG emission reduction globally but the magnitude varied by region. For example we found that in North Africa, hydropower development grew fast because of the rapid economic development, but it reached EEC as soon as in 2040 because of limitation in EEC due to its climatic and geographical conditions. Conversely, in Brazil, it grew steadily and did not reach its abundant EEC. Consequently, GHG mitigation contribution of North Africa is far less than Brazil. This research provides important information for policy makers to

  20. Predicting race time in male amateur marathon runners.

    Science.gov (United States)

    Salinero, Juan J; Soriano, María L; Lara, Beatriz; Gallo-Salazar, César; Areces, Francisco; Ruiz-Vicente, Diana; Abián-Vicén, Javier; González-Millán, Cristina; Del Coso, Juan

    2017-09-01

    The aim of the study was to analyze the relationship between anthropometry, training characteristics, muscular strength and effort-related cardiovascular response and marathon race time in male amateur runners. A total of 84 male amateur marathon runners aged between 23 and 70 years took part in this study (41.0±9.5 years). All of them competed in the 2013 edition of the Madrid Marathon with a finish time between 169.8 and 316 minutes (226.0±28.5 minutes). Age, running experience, number of marathon races finished, mean kilometers run weekly in the last three months, and previous personal best time in the 10 km, half marathon and marathon were recorded. Moreover, anthropometric characteristics, and the results from the Ruffier Test and a whole-body isometric force test were measured. After the marathon, the race time was registered. Training volume (r=-0.479; P=0.001), previous running milestones (marathon r=0.756; half-marathon r=0.812; 10-km r=0.732; P0.50. The best, including body fat percentage, heart rate change during the recovery after the Ruffier Test and the half-marathon race time, was strongly correlated with real marathon performance (r=0.77; P<0.001). A second regression model was proposed replacing the half-marathon performance with the 10-km race time, reducing the correlation to 0.73 (P<0.001). Marathon performance could be partially predicted by two different equations, including body fat percentage, recovery heart rate in the Ruffier Test and a half-marathon or 10-km performance.

  1. Foot Morphological Difference between Habitually Shod and Unshod Runners.

    Directory of Open Access Journals (Sweden)

    Yang Shu

    Full Text Available Foot morphology and function has received increasing attention from both biomechanics researchers and footwear manufacturers. In this study, 168 habitually unshod runners (90 males whose age, weight & height were 23±2.4 years, 66±7.1 kg & 1.68±0.13 m and 78 females whose age, weight & height were 22±1.8 years, 55±4.7 kg & 1.6±0.11 m (Indians and 196 shod runners (130 males whose age, weight & height were 24±2.6 years, 66±8.2 kg & 1.72±0.18 m and 66 females whose age, weight & height were 23±1.5 years, 54±5.6 kg & 1.62±0.15 m (Chinese participated in a foot scanning test using the easy-foot-scan (a three-dimensional foot scanning system to obtain 3D foot surface data and 2D footprint imaging. Foot length, foot width, hallux angle and minimal distance from hallux to second toe were calculated to analyze foot morphological differences. This study found that significant differences exist between groups (shod Chinese and unshod Indians for foot length (female p = 0.001, width (female p = 0.001, hallux angle (male and female p = 0.001 and the minimal distance (male and female p = 0.001 from hallux to second toe. This study suggests that significant differences in morphology between different ethnicities could be considered for future investigation of locomotion biomechanics characteristics between ethnicities and inform last shape and design so as to reduce injury risks and poor performance from mal-fit shoes.

  2. Exercise Behaviors and Health Conditions of Runners After Childbirth

    Science.gov (United States)

    Blyholder, Liga; Chumanov, Elizabeth; Carr, Kathleen; Heiderscheit, Bryan

    2016-01-01

    Background: With a recent increase in running popularity, more women choose to run during and after pregnancy. Little research has examined exercise behaviors and postpartum health conditions of runners. Hypothesis: Antenatal and postpartum exercise is beneficial in reducing certain postpartum health conditions. Study Design: Cross-sectional study. Level of Evidence: Level 5. Methods: A self-administered, online survey was developed that consisted of questions regarding antenatal and postpartum exercise behaviors, maternal history, and postpartum health conditions. The survey was completed by 507 postpartum women who were running a minimum of once per week. Results: Seventy-two percent of participants ran regularly during pregnancy, with 38% reporting running in the third trimester. Women with musculoskeletal pain during pregnancy were more likely to experience pain on return to running postpartum (odds ratio [OR], 3.08; 95% confidence interval [CI], 1.64-5.88). A birth spacing of women and those who reported a Caesarean section delivery were more likely to report abdominal separation (OR, 2.11; 95% CI, 1.08-4.26 and OR, 2.20; 95% CI, 1.05-4.70, respectively). Antenatal weight training decreased the odds of postpartum pain (OR, 0.52; 95% CI, 0.28-0.94), stress urinary incontinence (OR, 0.46; 95% CI, 0.21-0.98), and abdominal separation (OR, 0.51; 95% CI, 0.26-0.96). Conclusion: Musculoskeletal pain, stress urinary incontinence, and abdominal separation are prevalent conditions among postpartum runners and are more likely to occur with specific maternal history characteristics. Antenatal weight training may reduce the odds of each of these conditions. Clinical Relevance: Strengthening exercises during pregnancy may prevent weakening and dysfunction of the abdominal and pelvic floor muscles, decreasing the odds of pain, stress urinary incontinence, and abdominal separation after pregnancy. PMID:27742879

  3. Exercise Behaviors and Health Conditions of Runners After Childbirth.

    Science.gov (United States)

    Blyholder, Liga; Chumanov, Elizabeth; Carr, Kathleen; Heiderscheit, Bryan

    2016-10-14

    With a recent increase in running popularity, more women choose to run during and after pregnancy. Little research has examined exercise behaviors and postpartum health conditions of runners. Antenatal and postpartum exercise is beneficial in reducing certain postpartum health conditions. Cross-sectional study. Level 5. A self-administered, online survey was developed that consisted of questions regarding antenatal and postpartum exercise behaviors, maternal history, and postpartum health conditions. The survey was completed by 507 postpartum women who were running a minimum of once per week. Seventy-two percent of participants ran regularly during pregnancy, with 38% reporting running in the third trimester. Women with musculoskeletal pain during pregnancy were more likely to experience pain on return to running postpartum (odds ratio [OR], 3.08; 95% CI, 1.64-5.88). A birth spacing of Antenatal weight training decreased the odds of postpartum pain (OR, 0.52; 95% CI, 0.28-0.94), stress urinary incontinence (OR, 0.46; 95% CI, 0.21-0.98), and abdominal separation (OR, 0.51; 95% CI, 0.26-0.96). Musculoskeletal pain, stress urinary incontinence, and abdominal separation are prevalent conditions among postpartum runners and are more likely to occur with specific maternal history characteristics. Antenatal weight training may reduce the odds of each of these conditions. Strengthening exercises during pregnancy may prevent weakening and dysfunction of the abdominal and pelvic floor muscles, decreasing the odds of pain, stress urinary incontinence, and abdominal separation after pregnancy. © 2016 The Author(s).

  4. Empirical analysis on the runners' velocity distribution in city marathons

    Science.gov (United States)

    Lin, Zhenquan; Meng, Fan

    2018-01-01

    In recent decades, much researches have been performed on human temporal activity and mobility patterns, while few investigations have been made to examine the features of the velocity distributions of human mobility patterns. In this paper, we investigated empirically the velocity distributions of finishers in New York City marathon, American Chicago marathon, Berlin marathon and London marathon. By statistical analyses on the datasets of the finish time records, we captured some statistical features of human behaviors in marathons: (1) The velocity distributions of all finishers and of partial finishers in the fastest age group both follow log-normal distribution; (2) In the New York City marathon, the velocity distribution of all male runners in eight 5-kilometer internal timing courses undergoes two transitions: from log-normal distribution at the initial stage (several initial courses) to the Gaussian distribution at the middle stage (several middle courses), and to log-normal distribution at the last stage (several last courses); (3) The intensity of the competition, which is described by the root-mean-square value of the rank changes of all runners, goes weaker from initial stage to the middle stage corresponding to the transition of the velocity distribution from log-normal distribution to Gaussian distribution, and when the competition gets stronger in the last course of the middle stage, there will come a transition from Gaussian distribution to log-normal one at last stage. This study may enrich the researches on human mobility patterns and attract attentions on the velocity features of human mobility.

  5. Mixed maximal and explosive strength training in recreational endurance runners.

    Science.gov (United States)

    Taipale, Ritva S; Mikkola, Jussi; Salo, Tiina; Hokka, Laura; Vesterinen, Ville; Kraemer, William J; Nummela, Ari; Häkkinen, Keijo

    2014-03-01

    Supervised periodized mixed maximal and explosive strength training added to endurance training in recreational endurance runners was examined during an 8-week intervention preceded by an 8-week preparatory strength training period. Thirty-four subjects (21-45 years) were divided into experimental groups: men (M, n = 9), women (W, n = 9), and control groups: men (MC, n = 7), women (WC, n = 9). The experimental groups performed mixed maximal and explosive exercises, whereas control subjects performed circuit training with body weight. Endurance training included running at an intensity below lactate threshold. Strength, power, endurance performance characteristics, and hormones were monitored throughout the study. Significance was set at p ≤ 0.05. Increases were observed in both experimental groups that were more systematic than in the control groups in explosive strength (12 and 13% in men and women, respectively), muscle activation, maximal strength (6 and 13%), and peak running speed (14.9 ± 1.2 to 15.6 ± 1.2 and 12.9 ± 0.9 to 13.5 ± 0.8 km Ł h). The control groups showed significant improvements in maximal and explosive strength, but Speak increased only in MC. Submaximal running characteristics (blood lactate and heart rate) improved in all groups. Serum hormones fluctuated significantly in men (testosterone) and in women (thyroid stimulating hormone) but returned to baseline by the end of the study. Mixed strength training combined with endurance training may be more effective than circuit training in recreational endurance runners to benefit overall fitness that may be important for other adaptive processes and larger training loads associated with, e.g., marathon training.

  6. Opinions of Veteran Runners on The Influence Between Long-Distance Running and Holistically Interpreted Health

    Directory of Open Access Journals (Sweden)

    Oborný Josef

    2016-11-01

    Full Text Available The objective of the research was to determine the cognitive basis, the classification and evaluation of the long experience of long-distance runners in the senior category in relation to the perception of running as a factor in their overall health and wellbeing. Research was conducted with a sample of male and female long-distance runners with long experience in domestic and foreign longdistance running events in veteran categories. Oral and written interviews with the same questions were used to acquire information on the correlation between holistically understood health and long-term participation in long-distance running. The interview design allowed respondents to express their opinion on the questions in more detail through additional notes. A quantitative analysis of the acquired data was conducted using standard mathematical operations and the incidence of responses in percentage terms. The hypotheses were tested using a test on the parameter p of a binomial distribution and a median test. Senior-age long-distance runners’ decision to take up running was found to have both heteronomous motivation (encouragement by a sports teacher, admiration for other runners, persuasion by colleagues and autonomous motivation (an internal need to run, a means for overcoming mental stress and restoring internal balance, the need to lose weight, elimination of health problems, the desire to compete. The majority of runners agreed that long-distance running had a positive effect on their overall health and physical condition. Long-distance runners rated the effect of long-distance running on their social and personal wellbeing to be greater than three on a five-point scale did. There is no statistically significant difference between the number of runners who think that long practice of running has some negative effects on their health and the number of runners who think that it has no negative effects. The majority of runners think that their health

  7. Health Culture and Running: Non-Elite Runners' Understandings of Doping and Supplementation.

    Science.gov (United States)

    Henning, April D

    2015-01-01

    Participants at the non-elite level of road running often take up the sport for purposes of health, as a way of taking responsibility for their own well-being. Often, these runners use dietary supplements as a way to improve health and to potentially enhance running performance. Supplements are distinct from banned performance enhancing drugs (PEDs), as they are legal and widely available, though very loosely regulated. Research demonstrates that the line between supplements and banned PEDs is increasingly blurry as cases of cross-contaminated and mislabeled supplements continue to be found. Such products may pose health risks to unsuspecting consumers. Despite anti-doping agencies' warnings to elite runners about these risks, non-elite runners are rarely told by any sport or anti-doping body to be wary of supplements. They are, however, inundated with media coverage of doping scandals usually involving only a few of the substances banned in sport. In short, these runners are often left to navigate supplement use on their own and many conflate supplement availability with safety. This article explores these routine dietary supplement practices among non-elite runners. Drawing from interviews with 28 non-elite runners in New York City, I discuss the perceptions and understandings of doping and dietary supplement use within the context of health culture. Interview data reveal that the social acceptance of dietary supplements and their widespread use among the broader public reinforce the notion among non-elite runners that such products are objectively safe and healthy. I argue that based on their assumptions of supplement safety, non-elite runners view dietary supplements as distinctly different from PEDs and that this difference encourages their use as health and performance aids.

  8. A Rare Congenital Heart Disease in an Elderly Long-Distance Runner: A Case Report

    OpenAIRE

    Bhamidipati, K. R.; Shah, N. C.; Connaughton, M. C.

    2012-01-01

    Introduction. Cor triatriatum is a rare congenital heart disease found incidentally in children. Although cor triatriatum can be an incidental finding in asymptomatic adults; it is extremely rare to find elderly patients without symptoms and is unique in a long distance runner. Case Presentation. We present the case of an 83-year-old long-distance runner with cor triatriatum sinistrum and atrial fibrillation who continues to be asymptomatic and has continued to run long distances, retaini...

  9. Intrinsic foot muscle volume in experienced runners with and without chronic plantar fasciitis.

    Science.gov (United States)

    Cheung, R T H; Sze, L K Y; Mok, N W; Ng, G Y F

    2016-09-01

    Plantar fasciitis, a common injury in runners, has been speculated to be associated with weakness of the intrinsic foot muscles. A recent study reported that atrophy of the intrinsic forefoot muscles might contribute to plantar fasciitis by destabilizing the medial longitudinal arch. However, intrinsic foot muscle volume difference between individuals with plantar fasciitis and healthy counterparts remains unknown. This study examined the relationship of intrinsic foot muscle volume and incidence of plantar fasciitis. Case-control study. 20 experienced (≥5 years) runners were recruited. Ten of them had bilateral chronic (≥2 years) plantar fasciitis while the others were healthy characteristics-matched runners. Intrinsic muscle volumes of the participants' right foot were scanned with a 1.5T magnetic resonance system and segmented using established methods. Body-mass normalized intrinsic foot muscle volumes were compared between runners with and without chronic plantar fasciitis. There was significant greater rearfoot intrinsic muscle volume in healthy runners than runners with chronic plantar fasciitis (Cohen's d=1.13; p=0.023). A similar trend was also observed in the total intrinsic foot muscle volume but it did not reach a statistical significance (Cohen's d=0.92; p=0.056). Forefoot volume was similar between runners with and without plantar fasciitis. These results suggest that atrophy of intrinsic foot muscles may be associated with symptoms of plantar fasciitis in runners. These findings may provide useful information in rehabilitation strategies of chronic plantar fasciitis. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  10. Reliability and accuracy of Cooper's test in male long distance runners

    OpenAIRE

    Alvero-Cruz, J. R.; M.A. Giráldez García; Carnero, E.A.

    2016-01-01

    Objective: Endurance capacity can be assessed by field test such as Cooper's test; however, reliability and accuracy are rarely reported in the literature. It was our aims to describe reliability and accuracy of Cooper's test in long distance runners. Method: Fifteen male long distance runners performed twice all-out Cooper's test in a 400 m track. Total distance covered, maximum heart rate (HR) and rate of perceived exertion were recorded. Bias correction factor (Bc) was used to describe ...

  11. Comparison of left ventricular mechanics in runners versus bodybuilders using speckle tracking echocardiography

    OpenAIRE

    Szauder, Ipoly; Kov?cs, Attila; Pavlik, G?bor

    2015-01-01

    Background Athlete?s heart is a common definition for a broad spectrum of adaptations induced by intense exercise. We intended to compare left ventricular (LV) mechanics in two sports disciplines with different exercise nature: marathon runners (endurance) and bodybuilders (power). Methods 24 marathon or ultramarathon runners (R), 14 bodybuilders (B) and 15 healthy, sedentary male volunteers (N) were investigated. Beyond standard echocardiographic protocol, parasternal short-axis and apical r...

  12. Lower-limb dynamics and clinical outcomes for habitually shod runners who transition to barefoot running.

    Science.gov (United States)

    Hashish, Rami; Samarawickrame, Sachithra D; Sigward, Susan; Azen, Stanley P; Salem, George J

    2018-01-01

    Recent investigations have revealed lower vertical loading rates and knee energy absorption amongst experienced barefoot runners relative to those who rear-foot strike (RFS). Although this has led to an adoption of barefoot running amongst many recreational shoe runners, recent investigations indicate that the experienced barefoot pattern is not immediately realized. Therefore, the purpose this investigation was to quantify changes in lower-extremity dynamics and clinical outcomes measures for habitually shod runners who perform a transition to barefoot running. We examined lower-extremity dynamics and clinical outcomes for 26 RFS shod runners who performed an 8-10 week transition to barefoot running. Runners were evaluated at the University of Southern California's Musculoskeletal Biomechanics Research Laboratory. Foot-strike patterns, vertical load rates, and joint energetics were evaluated before and after the transition using inverse dynamics. Clinical assessments were conducted throughout the transition by two licensed clinicians. Eighteen of the 26 runners successfully completed the transition: 7 maintained a RFS, 8 adopted a mid-foot strike (MFS), and 3 adopted a forefoot strike (FFS) during novice barefoot running. Following the transition, novice MFS/FFS runners often demonstrated reversions in strike-patterns and associated reductions in ankle energetics. We report no change in loading rates and knee energy absorption across transition time points. Importantly, there were no adverse events other than transient pain and soreness. These findings indicate that runners do not innately adopt the biomechanical characteristics thought to lower injury risk in-response to an uninstructed barefoot running transition. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. The future of small hydropower within the European union. An environmental policy study based on the European Water framework directive and the renewable energy directive

    NARCIS (Netherlands)

    Pabbruwee, Kees

    2006-01-01

    Small hydropower facilities according to European Union (EU) standards have an installed capacity of less than 10 MW. The Renewable Energy Directive has set targets for installed capacity and electricity produced by small hydropower facilities to be reach

  14. Value of ecosystem hydropower service and its impact on the payment for ecosystem services.

    Science.gov (United States)

    Fu, B; Wang, Y K; Xu, P; Yan, K; Li, M

    2014-02-15

    Hydropower is an important service provided by ecosystems. We surveyed all the hydropower plants in the Zagunao River Basin, Southwest China. Then, we assessed the hydropower service by using the InVEST (The Integrated Value and Tradeoff of Ecosystem Service Tools) model. Finally, we discussed the impact on ecological compensation. The results showed that: 1) hydropower service value of ecosystems in the Zagunao River Basin is 216.29 Euro/hm(2) on the average, of which the high-value area with more than 475.65 Euro/hm(2) is about 750.37 km(2), accounting for 16.12% of the whole watershed, but it provides 53.47% of the whole watershed service value; 2) ecosystem is an ecological reservoir with a great regulation capacity. Dams cannot completely replace the reservoir water conservation function of ecosystems, and has high economic and environmental costs that must be paid as well. Compensation for water conservation services should become an important basis for ecological compensation of hydropower development. 3) In the current PES cases, the standard of compensation is generally low. Cascade development makes the value of upstream ecosystem services become more prominent, reflecting the differential rent value, and the value of ecosystem services should be based on the distribution of differentiated ecological compensation. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Hydropower developments in Canada: number, size and jurisdictional and ecological distribution

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Peter G.; Hanneman, Matt; Cheng, Ryan [Global Forest Watch Canada (Canada)

    2011-08-15

    For over 200 years, energy production and consumption, along with all human activities, have been contributing to global warming. This report is part of a project that examines 10 major energy sectors to provide information on Canada's energy options in the face of climate change; this present study gives information on hydropower reservoirs and associated dams in Canada. The mapping, jurisdictional and ecological distribution of reservoirs and dams across Canada is provided herein. Canada's hydropower installations are composed of 271 large hydropower facilities covering 58,015 km2 with a capacity of 71,857 MW, accounting for 44% of Canada's total technical hydroelectric capacity. Quebec, Ontario and British Columbia are the provinces with the most large hydropower dams; 19% of the watersheds are occupied in part by hydropower reservoirs and the taiga shield, boreal shield and montane cordillera ecozones contain most of the reservoir areas. The majority of future developments are expected to be built within 5km of intact forest landscapes.

  16. Examining global electricity supply vulnerability to climate change using a high-fidelity hydropower dam model.

    Science.gov (United States)

    Turner, Sean W D; Ng, Jia Yi; Galelli, Stefano

    2017-07-15

    An important and plausible impact of a changing global climate is altered power generation from hydroelectric dams. Here we project 21st century global hydropower production by forcing a coupled, global hydrological and dam model with three General Circulation Model (GCM) projections run under two emissions scenarios. Dams are simulated using a detailed model that accounts for plant specifications, storage dynamics, reservoir bathymetry and realistic, optimized operations. We show that the inclusion of these features can have a non-trivial effect on the simulated response of hydropower production to changes in climate. Simulation results highlight substantial uncertainty in the direction of change in globally aggregated hydropower production (~-5 to +5% change in mean global production by the 2080s under a high emissions scenario, depending on GCM). Several clearly impacted hotspots are identified, the most prominent of which encompasses the Mediterranean countries in southern Europe, northern Africa and the Middle East. In this region, hydropower production is projected to be reduced by approximately 40% on average by the end of the century under a high emissions scenario. After accounting for each country's dependence on hydropower for meeting its current electricity demands, the Balkans countries emerge as the most vulnerable (~5-20% loss in total national electricity generation depending on country). On the flipside, a handful of countries in Scandinavia and central Asia are projected to reap a significant increase in total electrical production (~5-15%) without investing in new power generation facilities. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Sustainability Risk Evaluation for Large-Scale Hydropower Projects with Hybrid Uncertainty

    Directory of Open Access Journals (Sweden)

    Weiyao Tang

    2018-01-01

    Full Text Available As large-scale hydropower projects are influenced by many factors, risk evaluations are complex. This paper considers a hydropower project as a complex system from the perspective of sustainability risk, and divides it into three subsystems: the natural environment subsystem, the eco-environment subsystem and the socioeconomic subsystem. Risk-related factors and quantitative dimensions of each subsystem are comprehensively analyzed considering uncertainty of some quantitative dimensions solved by hybrid uncertainty methods, including fuzzy (e.g., the national health degree, the national happiness degree, the protection of cultural heritage, random (e.g., underground water levels, river width, and fuzzy random uncertainty (e.g., runoff volumes, precipitation. By calculating the sustainability risk-related degree in each of the risk-related factors, a sustainable risk-evaluation model is built. Based on the calculation results, the critical sustainability risk-related factors are identified and targeted to reduce the losses caused by sustainability risk factors of the hydropower project. A case study at the under-construction Baihetan hydropower station is presented to demonstrate the viability of the risk-evaluation model and to provide a reference for the sustainable risk evaluation of other large-scale hydropower projects.

  18. Examining injury risk and pain perception in runners using minimalist footwear.

    Science.gov (United States)

    Ryan, Michael; Elashi, Maha; Newsham-West, Richard; Taunton, Jack

    2014-08-01

    This study examines the effect of progressive increases in footwear minimalism on injury incidence and pain perception in recreational runners. One hundred and three runners with neutral or mild pronation were randomly assigned a neutral (Nike Pegasus 28), partial minimalist (Nike Free 3.0 V2) or full minimalist shoe (Vibram 5-Finger Bikila). Runners underwent baseline testing to record training and injury history, as well as selected anthropometric measurements, before starting a 12-week training programme in preparation for a 10 km event. Outcome measures included number of injury events, Foot and Ankle Disability (FADI) scores and visual analogue scale pain rating scales for regional and overall pain with running. 99 runners were included in final analysis with 23 injuries reported; the neutral shoe reporting the fewest injuries (4) and the partial minimalist shoe (12) the most. The partial minimalist shoe reported a significantly higher rate of injury incidence throughout the 12-week period. Runners in the full minimalist group reported greater shin and calf pain. Running in minimalist footwear appears to increase the likelihood of experiencing an injury, with full minimalist designs specifically increasing pain at the shin and calf. Clinicians should exercise caution when recommending minimalist footwear to runners otherwise new to this footwear category who are preparing for a 10 km event. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  19. Numerical study on unidirectional fluid–solid coupling of Francis turbine runner

    Directory of Open Access Journals (Sweden)

    Kan Kan

    2015-03-01

    Full Text Available To analyze the fluid–solid coupling stress characteristics of the Francis turbine runner comprehensively, based on the Reynolds-averaged Navier–Stokes equations and shear stress transport k-ω turbulence model, this article performs numerical simulation of three-dimensional steady incompressible turbulent flow through the whole passage of a certain large Francis turbine under multiple operating conditions with Computational Fluid Dynamic software CFX and contrasts the result with that model test conversion. With the help of ANSYS workbench platform, equivalent stress, deformation distribution, and variation of the runner under multiple operating conditions are obtained through loading the water pressure on the runner blade as structural plane load to blades by the method of unidirectional fluid–solid coupling. The results show that under small flow operating conditions, flow patterns in the runner are disordered, the stress on the blade distributes unevenly, and the maximum stress lies on the influent side of the blades connected to the band; as the flow increases, the stress appears intensively around the effluent side of the blades connected to the runner crown. The maximum deformation first decreases and then increases as the flow increases. The deformation area expands from the middle effluent side of blades to the band. The results can be found in the researches on the structure design and the safety and stability of the Francis turbine runner.

  20. How do elite endurance runners alter movements of the spine and pelvis as running speed increases?

    Science.gov (United States)

    Preece, Stephen J; Mason, Duncan; Bramah, Christopher

    2016-05-01

    Elite endurance runners are characterised by their performance ability and higher running economy. However, there is relatively little research aimed at identifying the biomechanical characteristics of this group. This study aimed to understand how motions of the pelvis, lumbar spine and thorax change with speed in a cohort of elite endurance runners (n=14) and a cohort of recreational runners (n=14). Kinematic data were collected during over ground running at four speeds ranging from 3.3 to 5.6ms(-1) and a linear mixed model used to understand the effect of speed on both range of motion and mean sagittal inclination. The results showed the two groups to exhibit similar changes in range of motion as speed was increased, with the most pronounced increases being observed in the transverse plane. However, the adaptation of thorax inclination with speed differed between the two groups. Whereas the recreational runners increased thorax inclination as running speed was increased, elite endurance runners consistently maintained a more upright thorax position. This is the first study to identify specific differences in upper body motions between recreational and elite runners and the findings may have implications for training protocols aimed at improving running performance. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Medial tibial stress syndrome in high school cross-country runners: incidence and risk factors.

    Science.gov (United States)

    Plisky, Melody S; Rauh, Mitchell J; Heiderscheit, Bryan; Underwood, Frank B; Tank, Robert T

    2007-02-01

    Prospective cohort. To determine (1) the cumulative seasonal incidence and overall injury rate of medial tibial stress syndrome (MTSS) and (2) risk factors for MTSS with a primary focus on the relationship between navicular drop values and MTSS in high school cross-country runners. MTSS is a common injury among runners. However, few studies have reported the injury rate and risk factors for MTSS among adolescent runners. Data collected included measurement of bilateral navicular drop and foot length, and a baseline questionnaire regarding the runner's height, body mass, previous running injury, running experience, and orthotic or tape use. Runners were followed during the season to determine athletic exposures (AEs) and occurrence of MTSS. The overall injury rate for MTSS was 2.8/1000 AEs. Although not statistically different, girls had a higher rate (4.3/1000 AEs) than boys (1.7/1000 AEs) (P = .11). Logistic regression modeling indicated that only gender and body mass index (BMI) were significantly associated with the occurrence of MTSS. However, when controlled for orthotic use, only BMI was associated with risk of MTSS. No significant associations were found between MTSS and navicular drop or foot length. Our findings suggest that navicular drop may not be an appropriate measure to identify runners who may develop MTSS during a cross-country season; thus, additional studies are needed to identify appropriate preseason screening tools.

  2. Caffeine has a small effect on 5-km running performance of well-trained and recreational runners.

    Science.gov (United States)

    O'Rourke, Matthew P; O'Brien, Brendan J; Knez, Wade L; Paton, Carl D

    2008-04-01

    The purpose of this study was to investigate if caffeine ingestion improves 5-km time-trial performance in well-trained and recreational runners. Using a double-blind placebo-controlled design, 15 well-trained and 15 recreational runners completed two randomized 5-km time-trials, after ingestion of either 5mgkg(-1) of caffeine or a placebo. Caffeine ingestion significantly improved 5-km running performance in both the well-trained and recreational runners. In comparison to the placebo trial, the caffeine trial resulted in 1.1% (90% CI 0.4-1.6) and 1.0% (0.2-2%) faster times for the well-trained and recreational runners. Reliability testing of the recreational runners indicated a test-retest error of measurement of 1.4%. We conclude that caffeine ingestion is likely to produce small but significant gains in 5-km running performance for both well-trained and recreational runners.

  3. An ecological economic assessment of flow regimes in a hydropower dominated river basin: the case of the lower Zambezi River, Mozambique.

    Science.gov (United States)

    Fanaian, Safa; Graas, Susan; Jiang, Yong; van der Zaag, Pieter

    2015-02-01

    The flow regime of rivers, being an integral part of aquatic ecosystems, provides many important services benefiting humans in catchments. Past water resource developments characterized by river embankments and dams, however, were often dominated by one (or few) economic use(s) of water. This results in a dramatically changed flow regime negatively affecting the provision of other ecosystem services sustained by the river flow. This study is intended to demonstrate the value of alternative flow regimes in a river that is highly modified by the presence of large hydropower dams and reservoirs, explicitly accounting for a broad range of flow-dependent ecosystem services. In this study, we propose a holistic approach for conducting an ecological economic assessment of a river's flow regime. This integrates recent advances in the conceptualization and classification of ecosystem services (UK NEA, 2011) with the flow regime evaluation technique developed by Korsgaard (2006). This integrated approach allows for a systematic comparison of the economic values of alternative flow regimes, including those that are considered beneficial for aquatic ecosystems. As an illustration, we applied this combined approach to the Lower Zambezi Basin, Mozambique. Empirical analysis shows that even though re-operating dams to create environmentally friendly flow regimes reduces hydropower benefits, the gains to goods derived from the aquatic ecosystem may offset the forgone hydropower benefits, thereby increasing the total economic value of river flow to society. The proposed integrated flow assessment approach can be a useful tool for welfare-improving decision-making in managing river basins. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Bedload pulses in a hydropower affected alpine gravel bed river

    Science.gov (United States)

    Aigner, Johann; Kreisler, Andrea; Rindler, Rolf; Hauer, Christoph; Habersack, Helmut

    2017-08-01

    This study investigated the sediment resupply and transport dynamics at the Upper Drau River upstream of Lienz (Eastern Tyrol, Austria). Due to a hydropower plant, a 24 km long river reach of this alpine gravel bed river is under residual flow conditions, although sediment is still resupplied into the reach through many active torrents and tributaries. As a result, sediment deposition in the residual flow reach intensified, hence increasing maintenance efforts to stabilize this river section and ensure flood protection. In combination with a new sediment management program, a continuous bedload monitoring system was installed 2 km downstream of the residual reach in 2001 to support the development of adapted sediment management strategies. The surrogate bedload monitoring system consists of 16 impact plate geophones, installed over a 17 m wide cross section. The unprecedented 15-year dataset of high-resolution bedload intensity revealed a complex process of gravel storage and intermittent resupply from the residual reach, allowing the authors a detailed analysis of frequently occurring bedload pulses. These transport features are triggered by increased discharges during floods in the residual reach and created pronounced anticlockwise bedload hysteresis or, with a temporal shift to the event peak, caused distinct shifts in the bedload activity downstream. Bedload pulses produce very high bedload fluxes while in transit, tend to increase bedload flux in the post-event phase, and can alter and reduce the upstream sediment storage leading to a lowering of bedload availability for future pulses. The observed time lags between main discharge events and the arrival of the macro-pulses are correlated with mean water discharge during pulse propagation, thus enabling a prediction of the pulse arrival at the monitoring station solely based on the hydrograph. In combination with the hydrological setup of the reach, the observed bedload pulse time lags allowed an estimation of

  5. Small hydropower station Duennern Olten, Switzerland; Kleinwasserkraftwerk Munzingerareal, Duennern Olten. Vorprojekt

    Energy Technology Data Exchange (ETDEWEB)

    Eichenberger, P.

    2007-07-15

    This illustrated technical report for the Swiss Federal Office of Energy (SFOE) describes work done on the preliminary project for a small hydropower project to be realised in Olten, Switzerland. The goal of this project is to build a new hydropower installation on the Duennern stream in which the approximately 10 metres difference in height is to be used to generate around 1.6 GWh of power annually using a 345 kW turbine. The present situation is described as far as the existing channelled stream, water quantities and concessions, land ownership etc. are concerned. Four variants for the realisation of the new hydropower installation are presented and discussed. The report recommends a single variant that should be further studied and lists details of the project, including plans and cost estimates.

  6. Study on the adverse effects of hydropower development on international shipping

    Science.gov (United States)

    Wang, Changhong

    2017-04-01

    The Lancang - Mekong river is an important international waterway to Southeast Asia and South Asia, which has important strategic significance for promoting regional economic cooperation and safeguarding national economic and security interests. On the Mekong River, the main aim is to develop hydropower resources utilization and shipping. River Hydropower Stations are in Laos and designed by foreign enterprises according to the construction of BOT. In this study, on the basis of a lot of research work and extensive collection of relevant information, and, through in-depth analysis of research, it reveals that the upper Mekong River hydropower development have many adverse effects on international shipping, put forward related suggestions for the healthy and sustainable development of international shipping.

  7. Hydropower flexibility and transmission expansion to support integration of offshore wind

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos Antonio; Farahmand, Hossein; Jaehnert, S.

    2016-01-01

    systems are a very good option for balancing the natural variability of wind power production, especially when installed offshore. The flexibility of hydropower systems allows power systems with a high share of RES to maintain stability. The analysis presented indicates that the value of hydropower......In 2013, offshore wind grew over 50%. This increase, concentrated in a relatively small geographical area, can lead to an increased variability of the power produced by offshore wind. The variability is one of the key issues, along transmission, in integrating offshore wind power. Hydro power...... of hydro generation can match the variability of offshore wind, allowing for larger shares of variable generation to be integrated in the power systems without decreasing its stability. The analysis includes two interrelated models, a market model and a flow-based model. The results show that hydropower...

  8. Partial constraint satisfaction approaches for optimal operation of a hydropower system

    Science.gov (United States)

    Ferreira, Andre R.; Teegavarapu, Ramesh S. V.

    2012-09-01

    Optimal operation models for a hydropower system using partial constraint satisfaction (PCS) approaches are proposed and developed in this study. The models use mixed integer nonlinear programming (MINLP) formulations with binary variables. The models also integrate a turbine unit commitment formulation along with water quality constraints used for evaluation of reservoir downstream water quality impairment. New PCS-based models for hydropower optimization formulations are developed using binary and continuous evaluator functions to maximize the constraint satisfaction. The models are applied to a real-life hydropower reservoir system in Brazil. Genetic Algorithms (GAs) are used to solve the optimization formulations. Decision maker's preferences towards power production targets and water quality improvements are incorporated using partial satisfaction constraints to obtain compromise operating rules for a multi-objective reservoir operation problem dominated by conflicting goals of energy production, water quality and consumptive water uses.

  9. Numerical Analysis of Flow in Kaplan Turbine Runner Blades Anticavitation Lip with Modified Hydro-dynamic Profile

    Directory of Open Access Journals (Sweden)

    Vasile Cojocaru

    2011-09-01

    Full Text Available In order to increase the lifetime of runner blades of Kaplan turbines damaged by cavitation erosion, an anticavitation lip is attached to the periphery of the runner blades on the suction side. The anticavitation lip overtakes the cavitation pitting which appears between the runner blades and the runner chamber. A blade with the original anticavitation lip was modeled using CAE. The numerical simulations showed the tip vortex position and the source of the cavitation erosion. Using these data, a modified profile of the anticavitation lip was designed.

  10. Foot strike patterns of recreational and sub-elite runners in a long-distance road race.

    Science.gov (United States)

    Larson, Peter; Higgins, Erin; Kaminski, Justin; Decker, Tamara; Preble, Janine; Lyons, Daniela; McIntyre, Kevin; Normile, Adam

    2011-12-01

    Although the biomechanical properties of the various types of running foot strike (rearfoot, midfoot, and forefoot) have been studied extensively in the laboratory, only a few studies have attempted to quantify the frequency of running foot strike variants among runners in competitive road races. We classified the left and right foot strike patterns of 936 distance runners, most of whom would be considered of recreational or sub-elite ability, at the 10 km point of a half-marathon/marathon road race. We classified 88.9% of runners at the 10 km point as rearfoot strikers, 3.4% as midfoot strikers, 1.8% as forefoot strikers, and 5.9% of runners exhibited discrete foot strike asymmetry. Rearfoot striking was more common among our sample of mostly recreational distance runners than has been previously reported for samples of faster runners. We also compared foot strike patterns of 286 individual marathon runners between the 10 km and 32 km race locations and observed increased frequency of rearfoot striking at 32 km. A large percentage of runners switched from midfoot and forefoot foot strikes at 10 km to rearfoot strikes at 32 km. The frequency of discrete foot strike asymmetry declined from the 10 km to the 32 km location. Among marathon runners, we found no significant relationship between foot strike patterns and race times.

  11. Alpine hydropower in a low carbon economy: Assessing the local implication of global policies

    Science.gov (United States)

    Anghileri, Daniela; Castelletti, Andrea; Burlando, Paolo

    2016-04-01

    In the global transition towards a more efficient and low-carbon economy, renewable energy plays a major role in displacing fossil fuels, meeting global energy demand while reducing carbon dioxide emissions. In Europe, Variable Renewable Sources (VRS), such as wind and solar power sources, are becoming a relevant share of the generation portfolios in many countries. Beside the indisputable social and environmental advantages of VRS, on the short medium term the VRS-induced lowering energy prices and increasing price's volatility might challenge traditional power sources and, among them, hydropower production, because of smaller incomes and higher maintenance costs associated to a more flexible operation of power systems. In this study, we focus on the Swiss hydropower sector analysing how different low-carbon targets and strategies established at the Swiss and European level might affect energy price formation and thus impact - through hydropower operation - water availability and ecosystems services at the catchment scale. We combine a hydrological model to simulate future water availability and an electricity market model to simulate future evolution of energy prices based on official Swiss and European energy roadmaps and CO2 price trends in the European Union. We use Multi-Objective optimization techniques to design alternative hydropower reservoir operation strategies, aiming to maximise the hydropower companies' income or to provide reliable energy supply with respect to the energy demand. This integrated model allows analysing to which extent global low-carbon policies impact reservoir operation at the local scale, and to gain insight on how to prioritise compensation measures and/or adaptation strategies to mitigate the impact of VRS on hydropower companies in increasingly water constrained settings. Numerical results are shown for a real-world case study in the Swiss Alps.

  12. A methodology to quantify and optimize time complementarity between hydropower and solar PV systems

    Science.gov (United States)

    Kougias, Ioannis; Szabó, Sándor; Monforti-Ferrario, Fabio; Huld, Thomas; Bódis, Katalin

    2016-04-01

    Hydropower and solar energy are expected to play a major role in achieving renewable energy sources' (RES) penetration targets. However, the integration of RES in the energy mix needs to overcome the technical challenges that are related to grid's operation. Therefore, there is an increasing need to explore approaches where different RES will operate under a synergetic approach. Ideally, hydropower and solar PV systems can be jointly developed in such systems where their electricity output profiles complement each other as much as possible and minimize the need for reserve capacities and storage costs. A straightforward way to achieve that is by optimizing the complementarity among RES systems both over time and spatially. The present research developed a methodology that quantifies the degree of time complementarity between small-scale hydropower stations and solar PV systems and examines ways to increase it. The methodology analyses high-resolution spatial and temporal data for solar radiation obtained from the existing PVGIS model (available online at: http://re.jrc.ec.europa.eu/pvgis/) and associates it with hydrological information of water inflows to a hydropower station. It builds on an exhaustive optimization algorithm that tests possible alterations of the PV system installation (azimuth, tilt) aiming to increase the complementarity, with minor compromises in the total solar energy output. The methodology has been tested in several case studies and the results indicated variations among regions and different hydraulic regimes. In some cases a small compromise in the solar energy output showed significant increases of the complementarity, while in other cases the effect is not that strong. Our contribution aims to present these findings in detail and initiate a discussion on the role and gains of increased complementarity between solar and hydropower energies. Reference: Kougias I, Szabó S, Monforti-Ferrario F, Huld T, Bódis K (2016). A methodology for

  13. Framing hydropower as green energy: assessing drivers, risks and tensions in the Eastern Himalayas

    Science.gov (United States)

    Ahlers, R.; Budds, J.; Joshi, D.; Merme, V.; Zwarteveen, M.

    2015-04-01

    The culturally and ecologically diverse region of the Eastern Himalayas is the target of ambitious hydropower development plans. Policy discourses at national and international levels position this development as synergistically positive: it combines the production of clean energy to fuel economic growth at regional and national levels with initiatives to lift poor mountain communities out of poverty. Different from hydropower development in the 20th century in which development agencies and banks were important players, contemporary initiatives importantly rely on the involvement of private actors, with a prominent role of the private finance sector. This implies that hydropower development is not only financially viable but also understood as highly profitable. This paper examines the new development of hydropower in the Eastern Himalayas of Nepal and India. It questions its framing as green energy, interrogates its links with climate change, and examines its potential for investment and capital accumulation. To do this, we also review the evidence on the extent to which its construction and operation may modify existing hydrogeological processes and ecosystems, as well as its impacts on the livelihoods of diverse groups of people that depend on these. The paper concludes that hydropower development in the region is characterized by inherent contentions and uncertainties, refuting the idea that dams constitute development projects whose impacts can be simply predicted, controlled and mitigated. Indeed, in a highly complex geological, ecological, cultural and political context that is widely regarded to be especially vulnerable to the effects of climate change, hydropower as a development strategy makes for a toxic cocktail.

  14. Water, energy and agricultural landuse trends at Shiroro hydropower station and environs

    Science.gov (United States)

    Adegun, Olubunmi; Ajayi, Olalekan; Badru, Gbolahan; Odunuga, Shakirudeen

    2018-02-01

    The study examines the interplay among water resources, hydropower generation and agricultural landuse at the Shiroro hydropower station and its environs, in north-central Nigeria. Non-parametric trend analysis, hydropower footprint estimation, reservoir performance analysis, change detection analysis, and inferential statistics were combined to study the water-energy and food security nexus. Results of Mann-Kendall test and Sen's slope estimator for the period 1960 to 2013 showed a declining rainfall trend at Jos, around River Kaduna headwaters at -2.6 mm yr-1, while rainfall at Kaduna and Minna upstream and downstream of the reservoir respectively showed no trend. Estimates of hydropower footprint varied between 130.4 and 704.1 m3 GJ-1 between 1995 and 2013. Power generation reliability and resilience of the reservoir was 31.6 and 38.5 % respectively with year 2011 being the most vulnerable and least satisfactory. In addition to poor reliability and resilience indices, other challenges militating against good performance of hydropower generation includes population growth and climate change issues as exemplified in the downward trend observed at the headwaters. Water inflow and power generation shows a weak positive relationship with correlation coefficient (r) of 0.48, indicating less than optimal power generation. Total area of land cultivated increased from 884.59 km2 in 1986 prior to the commissioning of the hydropower station to 1730.83 km2 in 2016 which signifies an increased contribution of the dam to ensuring food security. The reality of reducing upstream rainfall amount coupled with high water footprint of electricity from the reservoir, therefore requires that a long term roadmap to improve operational coordination and management have to be put in place.

  15. Water, energy and agricultural landuse trends at Shiroro hydropower station and environs

    Directory of Open Access Journals (Sweden)

    O. Adegun

    2018-02-01

    Full Text Available The study examines the interplay among water resources, hydropower generation and agricultural landuse at the Shiroro hydropower station and its environs, in north-central Nigeria. Non-parametric trend analysis, hydropower footprint estimation, reservoir performance analysis, change detection analysis, and inferential statistics were combined to study the water-energy and food security nexus. Results of Mann–Kendall test and Sen's slope estimator for the period 1960 to 2013 showed a declining rainfall trend at Jos, around River Kaduna headwaters at −2.6 mm yr−1, while rainfall at Kaduna and Minna upstream and downstream of the reservoir respectively showed no trend. Estimates of hydropower footprint varied between 130.4 and 704.1 m3 GJ−1 between 1995 and 2013. Power generation reliability and resilience of the reservoir was 31.6 and 38.5 % respectively with year 2011 being the most vulnerable and least satisfactory. In addition to poor reliability and resilience indices, other challenges militating against good performance of hydropower generation includes population growth and climate change issues as exemplified in the downward trend observed at the headwaters. Water inflow and power generation shows a weak positive relationship with correlation coefficient (r of 0.48, indicating less than optimal power generation. Total area of land cultivated increased from 884.59 km2 in 1986 prior to the commissioning of the hydropower station to 1730.83 km2 in 2016 which signifies an increased contribution of the dam to ensuring food security. The reality of reducing upstream rainfall amount coupled with high water footprint of electricity from the reservoir, therefore requires that a long term roadmap to improve operational coordination and management have to be put in place.

  16. Development of New, Low-Head Hydropower Turbine - Modeling & Laboratory Test DE-EE0005426

    Energy Technology Data Exchange (ETDEWEB)

    Krouse, Wayne [Hydro Green Energy, Westmont, IL (United States)

    2014-12-05

    Hydro Green Energy, LLC (HGE) will complete the design, fabrication and laboratory testing of a scaled, vertically stackable, low-head hydropower turbine called the Modular Bulb Turbine (MBT). HGE will also complete a summary report that includes the laboratory testing results and analysis of the tests. Project Goals: Design, model and test modular bulb turbine for installation in numerous HGE low-head hydropower projects at non-powered USACE dams. Project Results: The sub-scale prototype was tested successfully at a leading US hydraulic laboratory. Laboratory data results agreed well with predicted results from numerical modeling.

  17. Hydropower : A Regulatory Guide to Permitting and Licensing in Idaho, Montana, Oregon, and Washington.

    Energy Technology Data Exchange (ETDEWEB)

    McCoy, Gilbert A.

    1992-12-01

    The design, construction and operation of a hydropower project can result in many potential impacts. These potential impacts are of concern to a host of federal, state, and local authorities. Early consultation with land and water management, fish and wildlife resource protection, and health and human safety-oriented agencies should occur to determine specific concerns and study requirements for each proposed project. This Guide to Permitting and Licensing outlines the characteristic features of attractive hydropower sites; summarizes an array of developmental constraints; illustrates potential environmental impacts and concerns; and summarizes all federal, state, and local permitting and licensing requirements.

  18. Hydropower: A Regulatory Guide to Permitting and Licensing in Idaho, Montana, Oregon, and Washington.

    Energy Technology Data Exchange (ETDEWEB)

    McCoy, Gilbert A.

    1992-12-01

    The design, construction and operation of a hydropower project can result in many potential impacts. These potential impacts are of concern to a host of federal, state, and local authorities. Early consultation with land and water management, fish and wildlife resource protection, and health and human safety-oriented agencies should occur to determine specific concerns and study requirements for each proposed project. This Guide to Permitting and Licensing outlines the characteristic features of attractive hydropower sites; summarizes an array of developmental constraints; illustrates potential environmental impacts and concerns; and summarizes all federal, state, and local permitting and licensing requirements.

  19. Evaluating run of the river hydropower feasibility and efficiency under climate change for UK study sites

    Science.gov (United States)

    Pasten-Zapata, Ernesto; Moggridge, Helen; Jones, Julie

    2015-04-01

    As renewable energy generation has been encouraged by the UK Government, hydropower importance has also been highlighted. Moreover, the UK Environment Agency has mapped feasible run of the river (ROR) hydropower sites within England and Wales and small hydropower schemes have been provided with economic grants by the Government to support their initial operation. However, ROR hydropower schemes depend on the available river flow volumes and are therefore vulnerable to variations in river regimes. Therefore, an analysis of the impacts of climate change towards existing and feasible run of the river schemes is important and required. The main objective of this research is to evaluate the impacts of climate change on river regimes and its implications to installed and feasible ROR hydropower operations by analyzing four study sites distributed across the UK. Study sites present different characteristics accounting for diverse properties of hydropower schemes including: catchment characteristics (topography, land use, climate, etc.), turbine type, turbine efficiency and head. Both feasible and currently operating schemes will be included in the analysis. Operating sites will be analysed according to their installed turbine type, hands off flow and maximum generation. On the other hand, feasible sites will be analysed considering different possible turbine types and changes in river flow that could affect the hands off flow and maximum generation thresholds. Future climate is simulated based on the temperature and precipitation outputs from Global Climate Models. Due to their relatively coarse resolution, output from these models will be downscaled, bias corrected and coupled to previously calibrated and validated hydrological models for each of the study catchments (linked to poster in session CL5.5/CR3.7/HS4.8/SSS12.14). By coupling model simulations of future climate change and hydrological models, future river flow volumes will be estimated and used as inputs for

  20. The Economic Benefits Of Multipurpose Reservoirs In The United States- Federal Hydropower Fleet

    Energy Technology Data Exchange (ETDEWEB)

    Hadjerioua, Boualem [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Witt, Adam M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Stewart, Kevin M. [Dept. of Energy (DOE), Washington DC (United States). Office of Energy Efficiency and Renewable Energy (EERE); Bonnet Acosta, Marisol [Dept. of Energy (DOE), Washington DC (United States). Office of Energy Efficiency and Renewable Energy (EERE); Mobley, Miles [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-01

    The United States is home to over 80,000 dams, of which approximately 3% are equipped with hydroelectric generating capabilities. When a dam serves as a hydropower facility, it provides a variety of energy services that range from clean, reliable power generation to load balancing that supports grid stability. In most cases, the benefits of dams and their associated reservoirs go far beyond supporting the nation s energy demand. As evidenced by the substantial presence of non-powered dams with the ability to store water in large capacities, the primary purpose of a dam may not be hydropower, but rather one of many other purposes. A dam and reservoir may support navigation, recreation, flood control, irrigation, and water supply, with each multipurpose benefit providing significant social and economic impacts on a local, regional, and national level. When hydropower is one of the services provided by a multipurpose reservoir, it is then part of an integrated system of competing uses. Operating rules, management practices, consumer demands, and environmental constraints must all be balanced to meet the multipurpose project s objectives. When federal dams are built, they are authorized by Congress to serve one or more functions. Legislation such as the Water Resources Development Act regulates the operation of the facility in order to coordinate the authorized uses and ensure the dam s intended objectives are being met. While multipurpose reservoirs account for billions of dollars in contributions to National Economic Development (NED) every year, no attempt has been made to evaluate their benefits on a national scale. This study is an on-going work conducted by Oak Ridge National Laboratory in an effort to estimate the economic benefits of multipurpose hydropower reservoirs in the United States. Given the important role that federal hydropower plays in the U.S., the first focus of this research will target the three main federal hydropower owners Tennessee Valley

  1. Integration of Hydropower in a Competitive power market model for water-energy scenario analysis

    DEFF Research Database (Denmark)

    Pereira Cardenal, Silvio Javier; Carrion-Sanchez, Laura; Arnbjerg-Nielsen, Karsten

    2011-01-01

    for the management of both water and energy resources, and should be assessed. We propose a coupled water-energy modeling approach in which a hydrological model imposes the water constraints on the power system model; hydropower generation is bid to the power market based on the hydrological state of the system....... The hydropower bidding strategy showed reasonable performance when tested in a simplified model of a competitive power market.......Hydrological systems and power systems are strongly linked: water is needed for most electricity generation technologies, and electricity is required for all stages of water usage. Growing water and energy demands, and potential climate changes suggest this relationship will become more important...

  2. Impacts of climate change on water resources and hydropower systems in central and southern Africa

    Energy Technology Data Exchange (ETDEWEB)

    Hamududu, Byman H.

    2012-11-15

    Climate change is altering hydrological processes with varying degrees in various regions of the world. This research work investigates the possible impacts of climate change on water resource and Hydropower production potential in central and southern Africa. The Congo, Zambezi and Kwanza, Shire, Kafue and Kabompo basins that lie in central and southern Africa are used as case studies. The review of climate change impact studies shows that there are few studies on impacts of climate change on hydropower production. Most of these studies were carried out in Europe and north America and very few in Asia, south America and Africa. The few studies indicate that southern Africa would experience reduction in precipitation and runoff, consequently reductions in hydropower production. There are no standard methods of assessing the resulting impacts. Two approaches were used to assess the impacts of climate change on water resources and hydropower. One approach is lumping changes on country or regional level and use the mean climate changes on mean annual flows as the basis for regional changes in hydropower production. This is done to get an overall picture of the changes on global and regional level. The second approach is a detailed assessment process in which downscaling, hydrological modelling and hydropower simulations are carried out. The possible future climate scenarios for the region of central and southern Africa depicted that some areas where precipitation are likely to have increases while other, precipitation will reduce. The region northern Zambia and southern Congo showed increases while the northern Congo basin showed reductions. Further south in southern African region, there is a tendency of decreases in precipitation. To the west, in Angola, inland showed increases while towards the coast highlighted some decreases in precipitation. On a global scale, hydropower is likely to experience slight changes (0.08%) due to climate change by 2050. Africa is

  3. Half-Marathon and Full-Marathon Runners' Hydration Practices and Perceptions

    Science.gov (United States)

    O'Neal, Eric K.; Wingo, Jonathan E.; Richardson, Mark T.; Leeper, James D.; Neggers, Yasmine H.; Bishop, Phil A.

    2011-01-01

    Context: The behaviors and beliefs of recreational runners with regard to hydration maintenance are not well elucidated. Objective: To examine which beverages runners choose to drink and why, negative performance and health experiences related to dehydration, and methods used to assess hydration status. Design: Cross-sectional study. Setting: Marathon registration site. Patients or Other Participants: Men (n = 146) and women (n = 130) (age = 38.3 ± 11.3 years) registered for the 2010 Little Rock Half-Marathon or Full Marathon. Intervention(s): A 23-item questionnaire was administered to runners when they picked up their race timing chips. Main Outcome Measure(s): Runners were separated into tertiles (Low, Mod, High) based on z scores derived from training volume, expected performance, and running experience. We used a 100-mm visual analog scale with anchors of 0 (never) and 100 (always). Total sample responses and comparisons between tertile groups for questionnaire items are presented. Results: The High group (58±31) reported greater consumption of sport beverages in exercise environments than the Low (42 ± 35 mm) and Mod (39 ± 32 mm) groups (P runners experienced 1 or more incidents in which they believed dehydration resulted in a major performance decrement, and 45% perceived dehydration to have resulted in adverse health effects. Twenty percent of runners reported monitoring their hydration status. Urine color was the method most often reported (7%), whereas only 2% reported measuring changes in body weight. Conclusions: Greater attention should be paid to informing runners of valid techniques to monitor hydration status and developing an appropriate individualized hydration strategy. PMID:22488182

  4. Bone density and cyclic ovarian function in trained runners and active controls.

    Science.gov (United States)

    Winters, K M; Adams, W C; Meredith, C N; Loan, M D; Lasley, B L

    1996-07-01

    This study was conducted to determine whether rigorous exercise training adversely affects ovarian hormone levels and bone health in cyclically menstruating trained runners. Ovarian hormones, bone mineral density (BMD), body composition, 3-d diet records, 3-d estimated energy expenditure, and menstrual histories were evaluated in 10 trained collegiate runners and 10 moderately active controls. The trained runners had lower total body calcium per kg of soft lean tissue measured by DEXA (P = 0.045). Half of the trained runners had experienced stress fractures compared with only one of the moderately active controls. The trained runners' lumbar (L2-L4) BMD (1.178 g.cm-2) was not significantly different from that of the active controls (1.283 g.cm-2) (P = 0.074) but, for all subjects combined, there wasa significant inverse relation between L2-L4 BMD and distance run per week (P = 0.036). Further, adding age, body weight, percent body fat, daily energy intake, and daily calcium intake to a stepwise multiple regression analysis did not significantly improve predictive precision. The trained runners consumed nearly twice the amount of calcium (1089 mg.d-1 vs 641 mg.d-1, respectively; P = 0.036), while intake of other nutrients did not differ significantly between groups. Urinary estrone conjugates (E1C) were lower in the trained runners during the early follicular phase (P = 0.028), while pregnanediol-3-glucuronide (PdG) was not significantly different between groups during the luteal phase (P = 0.213). Thus, it appears that lower estrogen production, especially during the early follicular phase, and not progesterone, is associated with lower whole body calcium per kg of soft lean tissue and, probably, L2-L4 BMD. Results of this study also suggest that regular menstrual cycles do not imply normal ovarian hormone function in young women who are engaged in either recreational or competitive running.

  5. Ovarian impairments of female recreational distance runners during a season of training.

    Science.gov (United States)

    Rosetta, L; Harrison, G A; Read, G F

    1998-01-01

    This study was carried out to investigate the relationship between the level of training and the impairment of ovarian function among female recreational distance runners, and its reversibility. Thirty-six female distance runners self-recorded, for 7 consecutive days each month, the duration and distance of daily running from October 1989 to May 1990 in Great Britain. During the last 3 months of the survey, saliva samples were taken for progesterone assay and a subsample was measured for body composition. No trend in weight loss was observed over the season of training. Amenorrheic (AM) and oligomenorrheic (Oligo) runners had a significantly lower body mass index than eumenorrheic (EU) and irregularly menstruating (IM) runners. The amenorrheic and oligomenorrheic subjects did not show any rise in progesterone, at any time, during the 3 months of sampling. The eumenorrheic subjects showed evidence of a rise in progesterone, though the mean level was always significantly lower than that of sedentary controls. The most severely impaired runners (AM and Oligo) ran more than EU or irregularly menstruating runners in this sample, had lower body weight, a younger age and had a significantly lower body mass index (BMI). They tended to run faster during training sessions than those with apparently normal menstrual cycle or just irregular periods. It is suggested that low BMI, which is an indicator of body energy stores, reflects the intensity of regular training runs among female athletes with a stable body weight. It is possible that repeated elevations of beta-endorphins or other suppressors of gonadotropin release, secreted above a level of training commonly exceeded by long distance runners, when concurrent with energy restriction, could contribute to impairment of menstrual cycle.

  6. A comparison of negative joint work and vertical ground reaction force loading rates in Chi runners and rearfoot-striking runners.

    Science.gov (United States)

    Goss, Donald Lee; Gross, Michael T

    2013-10-01

    Observational. To compare lower extremity negative joint work and vertical ground reaction force loading rates in rearfoot-striking (RS) and Chi runners. Alternative running styles such as Chi running have become a popular alternative to RS running. Proponents assert that this running style reduces knee joint loading and ground reaction force loading rates. Twenty-two RS and 12 Chi runners ran for 5 minutes at a self-selected speed on an instrumented treadmill. A 3-D motion analysis system was used to obtain kinematic data. Average vertical ground reaction force loading rate and negative work of the ankle dorsiflexors, ankle plantar flexors, and knee extensors were computed during the stance phase. Groups were compared using a 1-way analysis of covariance for each variable, with running speed and age as covariates. On average, RS runners demonstrated greater knee extensor negative work (RS, -0.332 J/body height × body weight [BH·BW]; Chi, -0.144 J/BH·BW; Preaction force loading rates than Chi runners (RS, 68.6 BW/s; Chi, 43.1 BW/s; Prates and knee extensor work, but may increase work of the ankle plantar flexors.

  7. IEA Wind Task 24 Integration of Wind and Hydropower Systems; Volume 1: Issues, Impacts, and Economics of Wind and Hydropower Integration

    Energy Technology Data Exchange (ETDEWEB)

    Acker, T.

    2011-12-01

    This report describes the background, concepts, issues and conclusions related to the feasibility of integrating wind and hydropower, as investigated by the members of IEA Wind Task 24. It is the result of a four-year effort involving seven IEA member countries and thirteen participating organizations. The companion report, Volume 2, describes in detail the study methodologies and participant case studies, and exists as a reference for this report.

  8. Head losses in small hydropower plant trash racks (SHP

    Directory of Open Access Journals (Sweden)

    N. Walczak

    2016-12-01

    Full Text Available Small hydropower plants (SHP are technical facilities that are part of alternative energy sources [Paish 2002]. They are primarily characterised by low unit power (in Poland below 5 MW and are often constructed on existing barrages. Electrical current produced by these plants is used to meet local demand. Considering the exploitation of SHPs, it is important to ensure a stable flow through turbines. Aggidis et al. [2010] analysed SHP equipment costs depending on the turbine set. The turbines are protected against damage with trash racks applied for capturing water-borne detritus, such as plant debris carried by water. However, trash racks as solid equipment of SHPs cause head losses, and as a consequence reduce the efficiency of the system. These losses result not only from the spacing of bars, their shape and the technical condition of the inlet chamber, but also from plant debris, its nature, and the quantity of accumulated material that effectively limits the flow. The plant debris captured on trash racks is characterised by diversity in terms of species composition related to the vegetation period and the area where hydraulic facilities are located. Therefore, it is important to maintain trash racks clean by regular removal of the accumulated material. In this context, modernised and newly built power plants are fitted with mechanical cleaners. In older facilities, manual intervention for regular cleaning is required. The present study analyses how the bar shape and the orientation angle of trash racks as well as the accumulated plant debris affect head losses. The results were obtained from laboratory tests. The research examined the impact the inclination angle of trash racks (30°, 60° and 80° has on head loss values for three different shapes of bars (cylindrical, angled and flat rectangular and various weight portions of plant debris (0.25, 0.375 and 0.5 kg. The summarised losses were determined by measuring the difference in water

  9. Dynamic Patterns of Forces and Loading Rate in Runners with Unilateral Plantar Fasciitis: A Cross-Sectional Study.

    Directory of Open Access Journals (Sweden)

    Ana Paula Ribeiro

    Full Text Available The etiology of plantar fasciitis (PF has been related to several risk factors, but the magnitude of the plantar load is the most commonly described factor. Although PF is the third most-common injury in runners, only two studies have investigated this factor in runners, and their results are still inconclusive regarding the injury stage.Analyze and compare the plantar loads and vertical loading rate during running of runners in the acute stage of PF to those in the chronic stage of the injury in relation to healthy runners.Forty-five runners with unilateral PF (30 acute and 15 chronic and 30 healthy control runners were evaluated while running at 12 km/h for 40 meters wearing standardized running shoes and Pedar-X insoles. The contact area and time, maximum force, and force-time integral over the rearfoot, midfoot, and forefoot were recorded and the loading rate (20-80% of the first vertical peak was calculated. Groups were compared by ANOVAs (p<0.05.Maximum force and force-time integral over the rearfoot and the loading rate was higher in runners with PF (acute and chronic compared with controls (p<0.01. Runners with PF in the acute stage showed lower loading rate and maximum force over the rearfoot compared to runners in the chronic stage (p<0.01.Runners with PF showed different dynamic patterns of plantar loads during running over the rearfoot area depending on the injury stage (acute or chronic. In the acute stage of PF, runners presented lower loading rate and forces over the rearfoot, possibly due to dynamic mechanisms related to pain protection of the calcaneal area.

  10. What do recreational runners think about risk factors for running injuries? A descriptive study of their beliefs and opinions.

    Science.gov (United States)

    Saragiotto, Bruno Tirotti; Yamato, Tiê Parma; Lopes, Alexandre Dias

    2014-10-01

    Qualitative study based on semi-structured interviews. To describe the beliefs and opinions of runners about risk factors associated with running injuries. Despite the health benefits of running, a high prevalence of injury has been reported in runners. Preventive strategies for running injuries may be more successful with a better knowledge of runners' beliefs. A semi-structured interview of recreational runners was based on the question, "What do you think can cause injuries in runners?" Analysis of the interviews was performed in 3 steps: (1) organizing the data into thematic units, (2) reading and reorganizing the data according to frequency of citation, and (3) interpreting and summarizing the data. The runner interviews were continued until no new beliefs and opinions of runners regarding injuries were being added to the data, indicating saturation of the topic. A total of 95 recreational runners (65 men, 30 women) between the ages of 19 and 71 years were interviewed. Of those interviewed, the average running experience was 5.5 years and approximately 45% had experienced a running-related injury in the past. The factors suggested by the runners were divided into extrinsic and intrinsic factors. The most cited extrinsic factors were "not stretching," "excess of training," "not warming up," "lack of strength," and "wearing the wrong shoes." For the intrinsic factors, the main terms cited were "not respecting the body's limitations" and "foot-type changes." Recreational runners mainly attributed injury to factors related to training, running shoes, and exceeding the body's limits. Knowing the factors identified in this study may contribute to the development of better educational strategies to prevent running injuries, as some of the runners' beliefs are not supported by the research literature.

  11. ACCURACY OF SELF-REPORTED FOOT STRIKE PATTERN IN INTERCOLLEGIATE AND RECREATIONAL RUNNERS DURING SHOD RUNNING.

    Science.gov (United States)

    Bade, Michael B; Aaron, Katie; McPoil, Thomas G

    2016-06-01

    Clinicians are interested in the foot strike pattern (FSP) in runners because of the suggested relationship between the strike pattern and lower extremity injury. The purpose of this study was to assess the ability of collegiate cross-country runners and recreational runners to self-report their foot strike pattern during running. Cross-sectional Study. Twenty-three collegiate cross-country and 23 recreational runners voluntarily consented to participate. Inclusion criteria included running at least 18 miles per week, experience running on a treadmill, no history of lower extremity congenital or traumatic deformity, or acute injury three months prior to the start of the study. All participants completed a pre-test survey to indicate their typical foot strike pattern during a training run (FSPSurvey). Prior to running, reflective markers were placed on the posterior midsole and the vamp of the running shoe. A high-speed camera was used to film each runner in standing and while running at his or her preferred speed on a treadmill. The angle between the vector formed by the two reflective markers and the superior surface of the treadmill was used to calculate the foot strike angle (FSA). To determine the foot strike pattern from the video data (FSPVideo), the static standing angle was subtracted from the FSA at initial contact of the shoe on the treadmill. In addition to descriptive statistics, percent agreement and Chi square analysis was used to determine distribution differences between the video analysis results and the survey. The results of the chi-square analysis on the distribution of the FSPSurvey in comparison to the FSPVideo were significantly different for both the XCRunners (p Runners (p recreational runners could correctly self-identified their foot strike pattern 56.5% and 43.5% of the time, respectively. The findings of this study suggest that the clinician cannot depend on an experienced runner to correctly self-identify their FSP. Clinicians

  12. Influence of chronic exercise on carotid atherosclerosis in marathon runners.

    Science.gov (United States)

    Taylor, Beth A; Zaleski, Amanda L; Capizzi, Jeffrey A; Ballard, Kevin D; Troyanos, Christopher; Baggish, Aaron L; D'Hemecourt, Pierre A; Dada, Marcin R; Thompson, Paul D

    2014-02-14

    The effect of habitual, high-intensity exercise training on the progression of atherosclerosis is unclear. We assessed indices of vascular health (central systolic blood pressure (SBP) and arterial stiffness as well as carotid intima-medial thickness (cIMT)) in addition to cardiovascular risk factors of trained runners versus their untrained spouses or partners to evaluate the impact of exercise on the development of carotid atherosclerosis. field study at Boston Marathon. 42 qualifiers (mean age±SD: 46±13 years, 21 women) for the 2012 Boston Marathon and their sedentary domestic controls (46±12 years, n=21 women). We measured medical and running history, vital signs, anthropometrics, blood lipids, C reactive protein (CRP), 10 years Framingham risk, central arterial stiffness and SBP and cIMT. Multiple cardiovascular risk factors, including CRP, non-high-density lipoprotein cholesterol, triglycerides, heart rate, body weight and body mass index (all p0.31) and were associated with age (all r≥0.41; p0.08 for interactions). The amplification of the central pressure waveform (augmentation pressure at heart rate 75 bpm) was also not different between the two groups (p=0.07) but was related to age (p<0.01) and group (p=0.02) in a multiple linear regression model. Habitual endurance exercise improves the cardiovascular risk profile, but does not reduce the magnitude of carotid atherosclerosis associated with age and cardiovascular risk factors.

  13. Phosphate-solubilizing bacteria associated with runner bean rhizosphere

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    Mihalache Gabriela

    2015-01-01

    Full Text Available Soil microorganisms, especially rhizobacteria, play a key role in soil phosphorus (P dynamics and the subsequent availability of phosphate to plants. Utilization of phosphate-solubilizing bacteria as biofertilizers instead of synthetic chemicals is known to improve plant growth through the supply of plant nutrients, and may help to sustain environmental health and soil productivity. The main purpose of this study was to identify new phosphate-solubilizing bacteria isolated from runner bean rhizosphere. Ten out of 25 isolated bacterial strains solubilized Ca3(PO42 in qualitative and quantitative P-solubilization. The strain that exhibited the highest potential to solubilize Ca3(PO42, was selected for further determination of the mechanisms involved in the process. The medium pH was measured, organic acids released in the culture medium were identified by HPLC analysis, and the acid and alkaline phosphatase activities were determined. Our results showed that strain R7 solubilized phosphorous through the production of various organic acids such as lactic, isocitric, tartaric and pyruvic acids, and that it can be used as a potential biofertilizer.

  14. Isokinetic analysis of ankle and ground reaction forces in runners and triathletes

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    Natália Mariana Silva Luna

    2012-09-01

    Full Text Available OBJECTIVE: To analyze and compare the vertical component of ground reaction forces and isokinetic muscle parameters for plantar flexion and dorsiflexion of the ankle between long-distance runners, triathletes, and nonathletes. METHODS: Seventy-five males with a mean age of 30.26 (±6.5 years were divided into three groups: a triathlete group (n=26, a long-distance runner group (n = 23, and a non-athlete control group. The kinetic parameters were measured during running using a force platform, and the isokinetic parameters were measured using an isokinetic dynamometer. RESULTS: The non-athlete control group and the triathlete group exhibited smaller vertical forces, a greater ground contact time, and a greater application of force during maximum vertical acceleration than the long-distance runner group. The total work (180º/s was greater in eccentric dorsiflexion and concentric plantar flexion for the non-athlete control group and the triathlete group than the long-distance runner group. The peak torque (60º/s was greater in eccentric plantar flexion and concentric dorsiflexion for the control group than the athlete groups. CONCLUSIONS: The athlete groups exhibited less muscle strength and resistance than the control group, and the triathletes exhibited less impact and better endurance performance than the runners.

  15. Half-marathon and full-marathon runners' hydration practices and perceptions.

    Science.gov (United States)

    O'Neal, Eric K; Wingo, Jonathan E; Richardson, Mark T; Leeper, James D; Neggers, Yasmine H; Bishop, Phil A

    2011-01-01

    The behaviors and beliefs of recreational runners with regard to hydration maintenance are not well elucidated. To examine which beverages runners choose to drink and why, negative performance and health experiences related to dehydration, and methods used to assess hydration status. Cross-sectional study. Marathon registration site. Men (n = 146) and women (n = 130) (age = 38.3 ± 11.3 years) registered for the 2010 Little Rock Half-Marathon or Full Marathon. A 23-item questionnaire was administered to runners when they picked up their race timing chips. Runners were separated into tertiles (Low, Mod, High) based on z scores derived from training volume, expected performance, and running experience. We used a 100-mm visual analog scale with anchors of 0 (never) and 100 (always). Total sample responses and comparisons between tertile groups for questionnaire items are presented. The High group (58±31) reported greater consumption of sport beverages in exercise environments than the Low (42 ± 35 mm) and Mod (39 ± 32 mm) groups (P sport beverages to be superior to water in meeting hydration needs (P hydration status. Urine color was the method most often reported (7%), whereas only 2% reported measuring changes in body weight. Greater attention should be paid to informing runners of valid techniques to monitor hydration status and developing an appropriate individualized hydration strategy.

  16. COMPARATIVE KINEMATIC MEASURES OF TREADMILL RUNNING WITH OR WITHOUT BODY WEIGHT SUPPORT IN RUNNERS

    Directory of Open Access Journals (Sweden)

    Duane Millslagle

    2005-12-01

    Full Text Available Treadmill walking and running using a supportive harness has been used as a training method to rehabilitate injured patients' walking or running gait. Comparison of full weight support (FWS and body weight support (BWS kinematic measures in competitive runners has received little attention. The purpose of this study was to compare selected FWS to BWS kinematic measures in healthy competitive runners. Ten male runners (age = 21.4 ± 1.5 years with a training regimen averaging 64 km per week at 3.8 m·s-1 participated. All participants ran three 3-minute trials. The randomized trial conditions were: FWS, 20% BWS, and 40% BWS. All conditions were videotaped with 2 cameras and a 21-point, 3-D model was generated for analysis. From the position-time data, cycle length (CL, cycle frequency (CF, time of contact (TC, hip-, knee-, ankle- range of motion in degrees (H-ROM, K-ROM, and A-ROM, respectively, and vertical displacement of the center of mass (COM were derived and compared. With increasing support conditions, cycle length increased. Cycle frequency, hip and ankle angle ranges, and COM vertical displacement decreased (p 0.05. BWS running produced significant changes in selected kinematic measures. These changes may provide insight into runners' behavior when using BWS in training or recovery from competition. Additional investigation of BWS training affect with competitive runners would be recommended

  17. Body composition by x-ray absorptiometry and bioelectrical impedance in female runners.

    Science.gov (United States)

    Pichard, C; Kyle, U G; Gremion, G; Gerbase, M; Slosman, D O

    1997-11-01

    Body composition interests athletes since athletic performance is influenced by and dependent on the proportion and total amount of fat-free mass (FFM) and fat mass. The use of bioelectrical impedance (BIA) has increased recently since portable instruments make the measurements easy to execute and relatively inexpensive. The purpose of this study was to test the degree of relationship between FFM and fat mass calculated in elite female runners with 12 different BIA formulas reported in the literature and measured by dual-energy x-ray absorptiometry (DXA). The present study shows that body composition by BIA is valid in female runners. Prediction equations used to calculate FFM and fat mass must be appropriate for this population subgroup and validated against other methods, such as DXA and hydrodensitometry. Those formulas that performed well in the controls gave poor results in the female runner and vice versa. The below average fat mass noted in female runners suggests that prediction equations for untrained women with average fat mass are inappropriate. The formula by RJL Systems-2 for women: FFM = 5.091 + 0.6483.height2/resistance + 0.1996.weight gave best predictions of FFM in female runners. Further research is necessary to validate BIA prediction formulas in other athletes.

  18. Anatomically asymmetrical runners move more asymmetrically at the same metabolic cost.

    Science.gov (United States)

    Seminati, Elena; Nardello, Francesca; Zamparo, Paola; Ardigò, Luca P; Faccioli, Niccolò; Minetti, Alberto E

    2013-01-01

    We hypothesized that, as occurring in cars, body structural asymmetries could generate asymmetry in the kinematics/dynamics of locomotion, ending up in a higher metabolic cost of transport, i.e. more 'fuel' needed to travel a given distance. Previous studies found the asymmetries in horses' body negatively correlated with galloping performance. In this investigation, we analyzed anatomical differences between the left and right lower limbs as a whole by performing 3D cross-correlation of Magnetic Resonance Images of 19 male runners, clustered as Untrained Runners, Occasional Runners and Skilled Runners. Running kinematics of their body centre of mass were obtained from the body segments coordinates measured by a 3D motion capture system at incremental running velocities on a treadmill. A recent mathematical procedure quantified the asymmetry of the body centre of mass trajectory between the left and right steps. During the same sessions, runners' metabolic consumption was measured and the cost of transport was calculated. No correlations were found between anatomical/kinematic variables and the metabolic cost of transport, regardless of the training experience. However, anatomical symmetry significant correlated to the kinematic symmetry, and the most trained subjects showed the highest level of kinematic symmetry during running. Results suggest that despite the significant effects of anatomical asymmetry on kinematics, either those changes are too small to affect economy or some plastic compensation in the locomotor system mitigates the hypothesized change in energy expenditure of running.

  19. Anatomically asymmetrical runners move more asymmetrically at the same metabolic cost.

    Directory of Open Access Journals (Sweden)

    Elena Seminati

    Full Text Available We hypothesized that, as occurring in cars, body structural asymmetries could generate asymmetry in the kinematics/dynamics of locomotion, ending up in a higher metabolic cost of transport, i.e. more 'fuel' needed to travel a given distance. Previous studies found the asymmetries in horses' body negatively correlated with galloping performance. In this investigation, we analyzed anatomical differences between the left and right lower limbs as a whole by performing 3D cross-correlation of Magnetic Resonance Images of 19 male runners, clustered as Untrained Runners, Occasional Runners and Skilled Runners. Running kinematics of their body centre of mass were obtained from the body segments coordinates measured by a 3D motion capture system at incremental running velocities on a treadmill. A recent mathematical procedure quantified the asymmetry of the body centre of mass trajectory between the left and right steps. During the same sessions, runners' metabolic consumption was measured and the cost of transport was calculated. No correlations were found between anatomical/kinematic variables and the metabolic cost of transport, regardless of the training experience. However, anatomical symmetry significant correlated to the kinematic symmetry, and the most trained subjects showed the highest level of kinematic symmetry during running. Results suggest that despite the significant effects of anatomical asymmetry on kinematics, either those changes are too small to affect economy or some plastic compensation in the locomotor system mitigates the hypothesized change in energy expenditure of running.

  20. Rearfoot alignment and medial longitudinal arch configurations of runners with symptoms and histories of plantar fasciitis

    Directory of Open Access Journals (Sweden)

    Ana Paula Ribeiro

    2011-01-01

    Full Text Available OBJECTIVE: To evaluate and compare rearfoot alignment and medial longitudinal arch index during static postures in runners, with and without symptoms and histories of plantar fasciitis (PF. INTRODUCTION: PF is the third most common injury in runners but, so far, its etiology remains unclear. In the literature, rearfoot misalignment and conformations of the longitudinal plantar arch have been described as risk factors for the development of PF. However, in most of the investigated literature, the results are still controversial, mainly regarding athletic individuals and the effects of pain associated with these injuries. METHODS: Forty-five runners with plantar fasciitis (30 symptomatic and 15 with previous histories of injuries and 60 controls were evaluated. Pain was assessed by a visual analogue scale. The assessment of rearfoot alignment and the calculations of the arch index were performed by digital photographic images. RESULTS: There were observed similarities between the three groups regarding the misalignments of the rearfoot valgus. The medial longitudinal arches were more elevated in the group with symptoms and histories of PF, compared to the control runners. CONCLUSIONS: Runners with symptoms or histories of PF did not differ in rearfoot valgus misalignments, but showed increases in the longitudinal plantar arch during bipedal static stance, regardless of the presence of pain symptoms.

  1. Rearfoot alignment and medial longitudinal arch configurations of runners with symptoms and histories of plantar fasciitis

    Science.gov (United States)

    Ribeiro, Ana Paula; Trombini-Souza, Francis; Tessutti, Vitor; Lima, Fernanda Rodrigues; de Camargo Neves Sacco, Isabel; João, Sílvia Maria Amado

    2011-01-01

    OBJECTIVE: To evaluate and compare rearfoot alignment and medial longitudinal arch index during static postures in runners, with and without symptoms and histories of plantar fasciitis (PF). INTRODUCTION: PF is the third most common injury in runners but, so far, its etiology remains unclear. In the literature, rearfoot misalignment and conformations of the longitudinal plantar arch have been described as risk factors for the development of PF. However, in most of the investigated literature, the results are still controversial, mainly regarding athletic individuals and the effects of pain associated with these injuries. METHODS: Forty-five runners with plantar fasciitis (30 symptomatic and 15 with previous histories of injuries) and 60 controls were evaluated. Pain was assessed by a visual analogue scale. The assessment of rearfoot alignment and the calculations of the arch index were performed by digital photographic images. RESULTS: There were observed similarities between the three groups regarding the misalignments of the rearfoot valgus. The medial longitudinal arches were more elevated in the group with symptoms and histories of PF, compared to the control runners. CONCLUSIONS: Runners with symptoms or histories of PF did not differ in rearfoot valgus misalignments, but showed increases in the longitudinal plantar arch during bipedal static stance, regardless of the presence of pain symptoms. PMID:21808870

  2. Incidence of Iron Deficiency and Iron Deficient Anemia in Elite Runners and Triathletes.

    Science.gov (United States)

    Coates, Alexandra; Mountjoy, Margo; Burr, Jamie

    2017-09-01

    To assess the incidence of iron deficiency (ID), and iron deficient anemia (IDA) within a cohort of highly trained runners and triathletes, and to examine the association of oral iron supplementation history with serum ferritin (sFe) and hemoglobin (Hb) concentrations. A retrospective analysis of routine blood test data taken from 2009 to 2015 from (n = 38) elite level runners and triathletes between the ages of 21 to 36 years. Oral iron supplement intake was assessed through a questionnaire. Triathletes (female, FT; male, MT) and runners (female, FR; male, MR) had higher incidence of at least 1 episode of ID (FT 60.0%, MT 37.5%, FR 55.6%, MR 31.3%) compared with values reported in the literature for endurance athletes (20%-50% females, 0%-17% males). Male triathletes and runners had a higher incidence of IDA than their female teammates (25% MT, 20% FT, 6.3% for MR, 0% FR), a finding which has previously not been reported. Hemoglobin concentrations were low, with incidence of Hb iron (mean 94 ± 115 mg/d), there was no observed correlation between iron intake and sFe or Hb. Even with monitoring and treatment in place, ID and IDA are significant concerns for the health and performance of elite runners and triathletes, and this issue affects males and females.

  3. Is the rearfoot pattern the most frequently foot strike pattern among recreational shod distance runners?

    Science.gov (United States)

    de Almeida, Matheus Oliveira; Saragiotto, Bruno Tirotti; Yamato, Tiê Parma; Lopes, Alexandre Dias

    2015-02-01

    To determine the distribution of the foot strike patterns among recreational shod runners and to compare the personal and training characteristics between runners with different foot strike patterns. Cross-sectional study. Areas of running practice in São Paulo, Brazil. 514 recreational shod runners older than 18 years and free of injury. Foot strike patterns were evaluated with a high-speed camera (250 Hz) and photocells to assess the running speed of participants. Personal and training characteristics were collected through a questionnaire. The inter-rater reliability of the visual foot strike pattern classification method was 96.7% and intra-rater reliability was 98.9%. 95.1% (n = 489) of the participants were rearfoot strikers, 4.1% (n = 21) were midfoot strikers, and four runners (0.8%) were forefoot strikers. There were no significant differences between strike patterns for personal and training characteristics. This is the first study to demonstrate that almost all recreational shod runners were rearfoot strikers. The visual method of evaluation seems to be a reliable and feasible option to classify foot strike pattern. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. FOOT AND LOWER LIMB DISEASES IN RUNNERS: ASSESSMENT OF RISK FACTORS

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    Francesco Di Caprio

    2010-12-01

    Full Text Available The present study analyzed the impact of the running style and the morphologic and functional characteristics of the foot on the incidence of non-traumatic foot and lower limb disorders in runners. From January 2004 to December 2008, we prospectively examined 166 runners, both recreational and competitive, involved in various running specialities, from three athletics clubs in Northern Italy. They were 86 males and 80 females, with a mean age of 31.1 ± 12.2 years. We considered non-traumatic foot and lower limb diseases reported during the follow-up period, which resulted in a minimum sport rest of two weeks. The incidence of these diseases was examined with respect to general characteristics, type of activity, foot morphology, running style. 59% of athletes reported one or more diseases. The most common were plantar fasciitis (31% of athletes and Achilles tendinopathies (24%. Overall, the more prone to injuries were males (60.9% of cases, competitive runners (70.9%, middle-distance runners (51.7%, and those using spike shoes (80.3%. Age, body weight and height were not important predictors of running injuries in general. Considering the morphological characteristics of the foot, the most prone to injury were the varus hindfoot (87.5% of cases and the cavus arch (71.4%. In conclusion, a deep knowledge of the factors predisposing runners to specific diseases, often chronic and highly debilitating for the athlete, may allow implementing effective therapeutic measures

  5. Body composition and two-compartment model assumptions in male long distance runners.

    Science.gov (United States)

    Penn, I W; Wang, Z M; Buhl, K M; Allison, D B; Burastero, S E; Heymsfield, S B

    1994-03-01

    Long distance running increases bone mineral mass, skeletal muscle weight, and extracellular fluid volume. Each of these changes may have an impact on classic two-compartment body composition methods that assume a constant fat-free body mass (FFM) density (1.100 g.cc-1), potassium content (65 mmol.kg-1 FFM), and hydration (0.73 kg H2O.kg-1 FFM). The aims of the present study were: to use newly developed multi-component methods to evaluate the validity of two-compartment methods in white male recreational long-distance runners (N = 10); and to compare the body composition of these runners to sedentary controls (N = 10) of similar age, body weight, and body mass index. Runners had a significantly smaller fraction of body weight as fat (P = 0.001) and a larger fraction of FFM as lower extremity skeletal muscle (P = 0.045) and bone (P = 0.049). Although FFM constituted a larger proportion of body weight in the runners, the fractional contributions of water, protein, and mineral were similar to those in the control group. There were no significant differences between the two groups in density of FFM, total body potassium/FFM, and total body water/FFM. New methods thus allow in-depth analyses of body composition in athletes, with results suggesting that classic two-compartment methods are valid in white recreational long-distance runners.

  6. Biomechanical risk factors in the development of medial tibial stress syndrome in distance runners.

    Science.gov (United States)

    Tweed, Jo L; Campbell, Jackie A; Avil, Steven J

    2008-01-01

    We investigated the relationship between functional and static foot posture and medial tibial stress syndrome in distance runners. Twenty-eight runners with a clinical diagnosis of medial tibial stress syndrome and 12 asymptomatic runners were assessed with the Foot Posture Index to measure static overpronation. Range of motion was measured at the talocrural joint, with the knee extended and flexed as was range of motion at the first metatarsophalangeal joint and the angular difference between the neutral and relaxed calcaneal stance positions. Each participant was then videotaped while running on a treadmill shod and unshod. This videotape was analyzed using freeze frame to identify abnormal or mistimed pronation at each phase of gait. The results were analyzed using logistic regression to give the probability that a runner is likely to experience medial tibial stress syndrome, predicted from the static measurements and dynamic observations. Variables identified as being significant predictors of medial tibial stress syndrome were the difference between the neutral and relaxed calcaneal stance positions, range of motion of the talocrural joint with the knee extended, early heel lift and abductory twist during gait, and apropulsive gait. Runners with suspected symptoms of medial tibial stress syndrome should be assessed dynamically and statically for abnormal or mistimed pronation.

  7. Hydropower Production in Future Climate Scenarios; the Case for the Zambezi River

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    Byman H. Hamududu

    2016-06-01

    Full Text Available Climate change remains a threat to water resources projects in southern Africa where impacts resulting from changes in climate are projected to be negative and worse than in most other regions of the world. This work presents an assessment of the impacts of climate change on water resources and hydropower production potential in the Zambezi River Basin. Future climate scenarios projected through the five General Circulation Model (GCM outputs are used as input in the impact assessment. The future projected climate scenarios are downscaled to find local and regional changes, and used in the Hydrologiska Byråns Vattenbalansavdelning (HBV hydrological model to assess climate change impacts on water resources in the river basin. According to the simulations, air temperature and potential evaporation are projected to increase, while rainfall is projected to decrease. The Zambezi hydropower system is likely to be affected negatively as a result of future climate changes. Increasing air temperature leading to increased evaporation, and reduced rainfall, both contribute to a decrease in resulting river flows and increased reservoir evaporation. Consequently, the decrease in water resources will lead to decreased hydropower production potential, by 9% in 2020s, 18% in 2050s and 28% in 2080s in the hydropower system, for a medium emission scenario, A1B.

  8. Hydropower and Water Framework Directive. Appendix 1; Wasserkraftnutzung und Wasserrahmenrichtlinien. Anhang 1

    Energy Technology Data Exchange (ETDEWEB)

    Keuneke, Rita; Dumont, Ulrich [Ingenieurbuero Floecksmuehle, Aachen (Germany)

    2011-11-15

    The contribution under consideration is the first appendix to the environmental research plan of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (Berlin, Federal Republic of Germany) on ''Hydropower and Water Framework Directive''. This appendix contains a description of the locations in the tributaries of the German river Weser.

  9. The degree of rationality in actual bidding of hydropower at Nord Pool

    DEFF Research Database (Denmark)

    Alnæs, Erik Nicholas; Grøndahl, Roger; Fleten, Stein-Erik

    2013-01-01

    In deregulated electricity markets, power producers bid to sell tomorrow's generation in day-ahead auctions. We analyse bids submitted by three medium to large sized Norwegian reservoir hydropower producers over four two-week periods in 2011. Being price takers, the producers maximize their profi...

  10. Dependence of hydropower energy generation on forests in the Amazon Basin at local and regional scales.

    Science.gov (United States)

    Stickler, Claudia M; Coe, Michael T; Costa, Marcos H; Nepstad, Daniel C; McGrath, David G; Dias, Livia C P; Rodrigues, Hermann O; Soares-Filho, Britaldo S

    2013-06-04

    Tropical rainforest regions have large hydropower generation potential that figures prominently in many nations' energy growth strategies. Feasibility studies of hydropower plants typically ignore the effect of future deforestation or assume that deforestation will have a positive effect on river discharge and energy generation resulting from declines in evapotranspiration (ET) associated with forest conversion. Forest loss can also reduce river discharge, however, by inhibiting rainfall. We used land use, hydrological, and climate models to examine the local "direct" effects (through changes in ET within the watershed) and the potential regional "indirect" effects (through changes in rainfall) of deforestation on river discharge and energy generation potential for the Belo Monte energy complex, one of the world's largest hydropower plants that is currently under construction on the Xingu River in the eastern Amazon. In the absence of indirect effects of deforestation, simulated deforestation of 20% and 40% within the Xingu River basin increased discharge by 4-8% and 10-12%, with similar increases in energy generation. When indirect effects were considered, deforestation of the Amazon region inhibited rainfall within the Xingu Basin, counterbalancing declines in ET and decreasing discharge by 6-36%. Under business-as-usual projections of forest loss for 2050 (40%), simulated power generation declined to only 25% of maximum plant output and 60% of the industry's own projections. Like other energy sources, hydropower plants present large social and environmental costs. Their reliability as energy sources, however, must take into account their dependence on forests.

  11. Sustainable Effects of Small Hydropower Substituting Firewood Program in Majiang County, Guizhou Province, China

    Directory of Open Access Journals (Sweden)

    Xiaoxia Zhang

    2017-06-01

    Full Text Available Small hydropower substituting fuel (SHSF is an ecological environment protection program to improve regional ecosystems and alleviate poverty. However, the sustainability of SHSF programs remains controversial due to lingering doubts about its potential for socioeconomic development and its environmental impacts. The sustainability of SHSF was examined based on field investigations and household questionnaire surveys. The results were as follows: (1 Biomass of SHSF protected masson pine (Pinus massoniana and weeping cypress (Platycladus orientalis plantations were 11.06 t·ha−1 and 7.15 t·ha−1 higher than unprotected plantations, respectively. Furthermore, the differences in ecosystem biomass were mainly derived from arbor biomass. While the energy conversion efficiency based on field investigations was merely 1.28 kg (kWh−1, which was only 64% of the empirical value and 54% of the guideline for accounting for the ecological benefit of small hydropower substituting fuel. (2 Households’ total income in SHSF villages was higher than in households with access to a hydropower plant but no substituting fuel or households with no hydropower plant. (3 Most of the households had a positive attitude towards SHSF because of its cheaper electricity and associated ecological environmental improvements. Overall, our results suggest optimistic and sustainable prospects for the SHSF program; however, continued education and policy communications are needed to sustain program success.

  12. Exploring the hydropower potential of future ice-free glacier basins

    Science.gov (United States)

    Round, Vanessa; Farinotti, Daniel; Huss, Matthias

    2017-04-01

    The retreat of glaciers over the next century will present new challenges related to water availability and cause significant changes to the landscape. The construction of dams in areas becoming ice-free has previously been suggested as a mitigation measure against changes to water resources in the European Alps. In Switzerland, a number of hydropower dams already exist directly below glaciers, and the hydropower potential of natural lakes left by retreating glaciers has been recognised. We expand these concepts to the regional, and ultimately global, scale to assess the potential of creating hydropower dams in glacier basins, encouraged by advantages such as relatively low ecological and social impacts, and the possibility to replicate the water storage capabilities of glaciers. In a first order assessment, dam volumes are computed using a subglacial topography model and dam walls simulated at the terminus of each glacier. Potential power production is then estimated from projected glacier catchment runoff until 2100 based on the Global Glacier Evolution Model (GloGEM), and penstock head approximated from a global digital elevation model. Based on this, a feasibility ranking system is presented which takes into account various proxies for cost, demand and impact, such as proximity to populations and existing infrastructure, geological risks and threatened species. The ultimate objective is to identify locations of glacier retreat which could most feasibly and beneficially be used for hydropower production.

  13. Evaluating financial risk management strategies under climate change for hydropower producers on the Great Lakes

    Science.gov (United States)

    Meyer, Eliot S.; Characklis, Gregory W.; Brown, Casey

    2017-03-01

    Hydropower on the Great Lakes makes up a substantial fraction of regional electricity generation capacity. Hydropower producers on the Niagara River (flowing between lakes Erie and Ontario) operate as run-of-river, and changing lake levels alter interlake flows reducing both generation and revenues. Index-based insurance contracts, wherein contract payouts are linked to lake levels, offer a tool for mitigating this risk. As a potentially useful tool, pricing of financial insurance is typically based on historical behavior of the index. However, uncertainty with respect to the impacts of climate change on lake level behavior and how this might translate to increased (or decreased) risk for those selling or buying the insurance remains unexplored. Portfolios of binary index-insurance contracts are developed for hydropower producers on the Niagara River, and their performance is evaluated under a range of climate scenarios. Climate Informed Decision Analysis is used to inform the sensitivity of these portfolios to potential shifts in long-term, climatological variations in water level behavior. Under historical conditions, hydropower producers can use portfolios costing 0.5% of mean revenues to increase their minimum revenue threshold by approximately 18%. However, a one standard deviation decrease in the 50 year mean water level potentially doubles the frequency with which these portfolios would underperform from the perspective of a potential insurer. Trade-offs between portfolio cost and the frequency of underperformance are investigated over a range of climate futures.

  14. History of Electricity in Lesotho and The Place of 'Muela Hydropower ...

    African Journals Online (AJOL)

    This paper examines the history of electricity in Lesotho from the colonial time to the present within the broader framework of socio-economic development. Taking the 'Muela hydropower plant, the Lesotho Electricity Corporation and the Southern African Power Pool as illustration, the paper raises three related arguments.

  15. Tools for Small Hydropower Plant Resource Planning and Development: A Review of Technology and Applications

    Directory of Open Access Journals (Sweden)

    Gitana Vyciene

    2011-08-01

    Full Text Available This paper reviews and compares software tools for the planning and design of small hydropower (SHP plants. The main emphasis is on small scale hydropower resource assessment computer tools and methodologies for the development of SHP plants corresponding to a preliminary or prefeasibility study level. The paper presents a brief evaluation of the historic software tools and the current tools used in the small hydro industry. The reviewed tools vary from simple initial estimates to quite sophisticated software. The integration of assessment tools into Geographic Information System (GIS environments has led to a leap forward in the strengthening of the evaluation of the power potential of water streams in the case of the spatial variability of different factors affecting stream power. A number of countries (e.g., Canada, Italy, Norway, Scotland and the US have re-assessed their hydropower capacities based on spatial information of their water stream catchments, developing tools for automated hydro-site identification and deploying GIS-based tools, so-called Atlases, of small-scale hydropower resources on the Internet. However, a reliable assessment of real SHP site feasibility implies some “on the ground” surveying, but this traditional assessment can be greatly facilitated using GIS techniques that involve the spatial variability of catchment characteristics.

  16. Framing hydropower as green energy: assessing drivers, risks and tensions in the Eastern Himalayas

    NARCIS (Netherlands)

    Ahlers, R.; Budds, J.; Joshi, D.; Verme, V.; Zwarteveen, M.Z.

    2015-01-01

    The culturally and ecologically diverse region of the Eastern Himalayas is the target of ambitious hydropower development plans. Policy discourses at national and international levels position this development as synergistically positive: it ombines the production of clean energy to fuel economic

  17. Framing hydropower as green energy: assessing drivers, risks and tensions in the Eastern Himalayas

    NARCIS (Netherlands)

    Ahlers, R.; Budds, J.; Joshi, D.; Merme, V.; Zwarteveen, M.

    2015-01-01

    The culturally and ecologically diverse region of the Eastern Himalayas is the target of ambitious hydropower development plans. Policy discourses at national and international levels position this development as synergistically positive: it combines the production of clean energy to fuel economic

  18. Framing hydropower as green energy: assessing drivers, risks and tensions in the Eastern Himalayas

    NARCIS (Netherlands)

    Ahlers, R.; Budds, J.; Joshi, D.; Merme, V.; Zwarteveen, M.Z.

    2014-01-01

    The culturally and ecologically diverse region of the Eastern Himalayas is the target of ambitious hydropower development plans. Policy discourses at national and international levels position this development as synergistically positive: it combines the production of clean energy to fuel economic

  19. Dilemmas of hydropower development in Vietnam : between dam-induced displacement and sustainable development

    NARCIS (Netherlands)

    Ty, P.H.

    2015-01-01

    The goal of this book is to explain the controversies related to hydropower development in Vietnam in order to make policy recommendations for equitable and sustainable development. This book focuses on the analysis of emerging issues, such as land acquisition, compensation for losses, displacement

  20. Evaluation of Power Generation Efficiency of Cascade Hydropower Plants: A Case Study

    Directory of Open Access Journals (Sweden)

    Jiahua Wei

    2013-02-01

    Full Text Available Effective utilization of scarce water resources has presented a significant challenge to respond to the needs created by rapid economic growth in China. In this study, the efficiency of the joint operation of the Three Gorges and Gezhouba cascade hydropower plants in terms of power generation was evaluated on the basis of a precise simulation-optimization technique. The joint operation conditions of the Three Gorges and Gezhouba hydropower plants between 2004 and 2010 were utilized in this research in order to investigate the major factors that could affect power output of the cascade complex. The results showed that the current power output of the Three Gorges and Gezhouba cascade complex had already reached around 90% of the maximum theoretical value. Compared to other influencing factors evaluated in this study, the accuracy of hydrological forecasts and flood control levels can have significant impact on the power generating efficiency, whereas the navigation has a minor influence. This research provides a solid quantitative-based methodology to assess the operation efficiency of cascade hydropower plants, and more importantly, proposes potential methods that could improve the operation efficiency of cascade hydropower plants.

  1. Hydropower, Anti-Politics, and the Opening of New Political Spaces in the Eastern Himalayas

    NARCIS (Netherlands)

    Huber, A.; Joshi, D.

    2015-01-01

    Hydropower has lately been advocated by a multi-scalar public–private policy nexus for marrying objectives of green growth and climate mitigation. Such discursive constructions are reminiscent of a consensual development politics, which contradicts and overlooks long-standing socio-environmental

  2. Small hydropower in Southern Africa: an overview of five countries in the region

    CSIR Research Space (South Africa)

    Jonker Klunne, W

    2013-08-01

    Full Text Available frameworks that facilitate IPPs and Power Purchase Agreements with the national utility do provide a basis for (local) commercial banks to provide finance. Off-grid hydropower for rural electrification purposes sees activities in the countries with an active...

  3. National hydroelectric power resources study. Preliminary inventory of hydropower resources. Volume 1. Pacific Northwest region

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-07-01

    The preliminary inventory and analysis procedures provide a comprehensive assessment of the undeveloped hydroelectric power potential in the US and determines which sites merit more thorough investigation. Over 5400 existing structures have been identified as having the physical potential to add hydropower plants or increase hydropower output thereby increasing our present hydropower capacity from a total of 64,000 MW to 158,000 MW and our energy from 280,000 GWH to 503,000 GWH. While the physical potential for this increase is clearly available, some of these projects will undoubtedly not satisfy more-detailed economic analysis as well as the institutional and environmental criteria which will be imposed upon them. Summary tables include estimates of the potential capacity and energy at each site in the inventory. In some cases, individual projects may be site alternatives to others in the same general location, when only one can be considered for hydropower development. The number of sites per state is identified, but specific information is included for only the sites in Alaska, Idaho, Oregon, and Washington in this first volume.

  4. Climate impacts on hydropower and consequences for global electricity supply investment needs

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Sean W. D.; Hejazi, Mohamad; Kim, Son H.; Clarke, Leon; Edmonds, Jae

    2017-12-01

    Recent progress in global scale hydrological and dam modeling has allowed for the study of climate change impacts on global hydropower production. Here we explore the possible consequences of these impacts for the electricity supply sector. Regional hydropower projections are developed for two emissions scenarios by forcing a coupled global hydrological and dam model with downscaled, bias-corrected climate realizations derived from sixteen general circulation models. Consequent impacts on power sector composition and associated emissions and investment costs are explored using the Global Change Assessment Model (GCAM). Changes in hydropower generation resulting from climate change can shift power demands onto and away from carbon intensive technologies, resulting in significant impacts on power sector CO2 emissions for certain world regions—primarily those located in Latin America, as well as Canada and parts of Europe. Reduced impacts of climate change on hydropower production under a low emissions scenario coincide with increased costs of marginal power generating capacity—meaning impacts on power sector investment costs are similar for high and low emissions scenarios. Individual countries where impacts on investment costs imply significant risks or opportunities are identified.

  5. Hydropower-induced land use change in Fincha's watershed, werstern Ethiopia: analysis and impacts

    NARCIS (Netherlands)

    Bezuayehu, T.O.; Sterk, G.

    2008-01-01

    The present article analyzes the land use dynamics caused by hydropower dam construction in 1973 in the Fincha'a watershed (1318 km2), a tributary of the Blue Nile. Aerial photos (1957 and 1980) and an ASTER satellite image of 2001 were used to make 3 land use maps of the watershed using a

  6. High-resolution assessment of global technical and economic hydropower potential

    Science.gov (United States)

    Gernaat, David E. H. J.; Bogaart, Patrick W.; Vuuren, Detlef P. van; Biemans, Hester; Niessink, Robin

    2017-10-01

    Hydropower is the most important renewable energy source to date, providing over 72% of all renewable electricity globally. Yet, only limited information is available on the global potential supply of hydropower and the associated costs. Here we provide a high-resolution assessment of the technical and economic potential of hydropower at a near-global scale. Using 15"×15" discharge and 3"×3" digital elevation maps, we built virtual hydropower installations at >3.8 million sites across the globe and calculated their potential using cost optimization methods. This way we identified over 60,000 suitable sites, which together represent a remaining global potential of 9.49 PWh yr-1 below US0.50 kWh-1. The largest remaining potential is found in Asia Pacific (39%), South America (25%) and Africa (24%), of which a large part can be produced at low cost (

  7. Viewpoint – Better Management of Hydropower in an Era of Climate Change

    Directory of Open Access Journals (Sweden)

    Jamie Pittock

    2010-06-01

    Full Text Available Ten years ago the World Commission on Dams (WCD report established new standards for the sustainable development of water infrastructure, but the hopes many of us had then for a new era of more thoughtful development have been attenuated by the resilience of the hydraulic bureaucracy and the emergence of new influences on the hydropower debate. Particularly important is the impact of climate change as a driver of government policies in favour of hydropower, water storage and inter-basin water transfers. As a former Director of Freshwater for WWF International and now as a researcher on the water-energy nexus, I spent much of the past decade seeking to influence the direction of water infrastructure development, and in this viewpoint I have been asked to reflect on the changes that have occurred, and the opportunities in an era of climate change to reduce the environmental and social impacts of hydropower development while maximising the benefits. Better outcomes are more likely with a renewed focus on limiting the perverse impacts of climate change policies, implementing standards for certification of more sustainable hydropower, building capacities within developing countries, and enhancing management of existing dams.

  8. 76 FR 65717 - Erie Boulevard Hydropower, L.P.; Notice of Availability of Environmental Assessment

    Science.gov (United States)

    2011-10-24

    ... Energy Regulatory Commission Erie Boulevard Hydropower, L.P.; Notice of Availability of Environmental Assessment In accordance with the National Environmental Policy Act of 1969 and the Federal Energy Regulatory... has prepared an Environmental Assessment (EA) for the project. The project does not occupy any federal...

  9. 76 FR 35208 - Boott Hydropower, Inc.; Notice of Availability of Draft Environmental Assessment

    Science.gov (United States)

    2011-06-16

    ... Federal Energy Regulatory Commission Boott Hydropower, Inc.; Notice of Availability of Draft Environmental Assessment In accordance with the National Environmental Policy Act of 1969 and the Federal Energy Regulatory... draft environmental assessment (draft EA). The project is located on the Merrimack River in Middlesex...

  10. 76 FR 40719 - Northern Illinois Hydropower, LLC; Notice of Availability of Environmental Assessment

    Science.gov (United States)

    2011-07-11

    ... Energy Regulatory Commission Northern Illinois Hydropower, LLC; Notice of Availability of Environmental Assessment In accordance with the National Environmental Policy Act of 1969 and the Federal Energy Regulatory... a multi-project environmental assessment (EA), which analyzes the potential environmental effects of...

  11. 76 FR 46287 - Erie Boulevard Hydropower, L.P.; Notice of Availability of Environmental Assessment

    Science.gov (United States)

    2011-08-02

    ... Energy Regulatory Commission Erie Boulevard Hydropower, L.P.; Notice of Availability of Environmental Assessment In accordance with the National Environmental Policy Act of 1969 and the Federal Energy Regulatory... environmental assessment (EA). The project is located on the Sacandaga River in Saratoga County, New York. The...

  12. 76 FR 80924 - Boott Hydropower, Inc.; Notice of Availability of Final Environmental Assessment

    Science.gov (United States)

    2011-12-27

    ... Energy Regulatory Commission Boott Hydropower, Inc.; Notice of Availability of Final Environmental Assessment In accordance with the National Environmental Policy Act of 1969 and ] the Federal Energy... an environmental assessment (EA). The project is located on the Merrimack River in Middlesex County...

  13. 78 FR 79433 - Mahoning Hydropower, LLC, Ohio, Notice of Availability of Environmental Assessment

    Science.gov (United States)

    2013-12-30

    ... Energy Regulatory Commission Mahoning Hydropower, LLC, Ohio, Notice of Availability of Environmental Assessment In accordance with the National Environmental Policy Act of 1969 and the Federal Energy Regulatory... Resources. The project would not occupy federal lands. Staff prepared an environmental assessment (EA...

  14. 78 FR 71601 - KC Small Hydro LLC; Advanced Hydropower, Inc.; Notice of Preliminary Permit Application Accepted...

    Science.gov (United States)

    2013-11-29

    ... electrical control booth constructed on top of the intake tower; and (3) a 700- foot-long, 13.2 kilo-Volt (kV... 4.36. Comments, motions to intervene, notices of intent, and competing applications may be filed...

  15. Energy-Water Nexus Relevant to Baseload Electricity Source Including Mini/Micro Hydropower Generation

    Science.gov (United States)

    Fujii, M.; Tanabe, S.; Yamada, M.

    2014-12-01

    Water, food and energy is three sacred treasures that are necessary for human beings. However, recent factors such as population growth and rapid increase in energy consumption have generated conflicting cases between water and energy. For example, there exist conflicts caused by enhanced energy use, such as between hydropower generation and riverine ecosystems and service water, between shale gas and ground water, between geothermal and hot spring water. This study aims to provide quantitative guidelines necessary for capacity building among various stakeholders to minimize water-energy conflicts in enhancing energy use. Among various kinds of renewable energy sources, we target baseload sources, especially focusing on renewable energy of which installation is required socially not only to reduce CO2 and other greenhouse gas emissions but to stimulate local economy. Such renewable energy sources include micro/mini hydropower and geothermal. Three municipalities in Japan, Beppu City, Obama City and Otsuchi Town are selected as primary sites of this study. Based on the calculated potential supply and demand of micro/mini hydropower generation in Beppu City, for example, we estimate the electricity of tens through hundreds of households is covered by installing new micro/mini hydropower generation plants along each river. However, the result is based on the existing infrastructures such as roads and electric lines. This means that more potentials are expected if the local society chooses options that enhance the infrastructures to increase micro/mini hydropower generation plants. In addition, further capacity building in the local society is necessary. In Japan, for example, regulations by the river law and irrigation right restrict new entry by actors to the river. Possible influences to riverine ecosystems in installing new micro/mini hydropower generation plants should also be well taken into account. Deregulation of the existing laws relevant to rivers and

  16. The Second Assessment of the Effects of Climate Change on Federal Hydropower

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Shih-Chieh [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ashfaq, Moetasim [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Naz, Bibi S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Uria Martinez, Rocio [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rastogi, Deeksha [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mei, Rui [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jager, Yetta [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Samu, Nicole M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sale, Michael J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-09-01

    Hydropower is a key contributor to the US renewable energy portfolio due to its established development history and the diverse benefits it provides to the electric power system. Ensuring the sustainable operation of existing hydropower facilities is of great importance to the US renewable energy portfolio and the reliability of electricity grid. As directed by Congress in Section 9505 of the SECURE Water Act (SWA) of 2009 (Public Law 111-11), the US Department of Energy (DOE), in consultation with the federal Power Marketing Administrations (PMAs) and other federal agencies, has prepared a second quinquennial report on examining the potential effects of climate change on water available for hydropower at federal facilities and on the marketing of power from these federal facilities. This Oak Ridge National Laboratory (ORNL) Technical Memorandum, referred to as the 9505 assessment, describes the technical basis for the report to Congress that was called for in the SWA. To evaluate the potential climate change effects on 132 federal hydropower plants across the entire US, a spatially consistent assessment approach is designed to enable an interregional comparison. This assessment uses a series of models and methods with different spatial resolutions to gradually downscale the global climate change signals into watershed-scale hydrologic projections to support hydropower impact assessment. A variety of historic meteorological and hydrologic observations, hydropower facility characteristics, and geospatial datasets is collected to support model development, calibration, and verification. Among most of the federal hydropower plants throughout the US, the most important climate change effect on hydrology is likely to be the trend toward earlier snowmelt and change of runoff seasonality. Under the projections of increasing winter/spring runoff and decreasing summer/fall runoff, water resource managers may need to consider different water use allocations. With the

  17. Crawling to the finish line-why do endurance runners collapse? Implications for understanding the mechanisms underlying fatigue and pacing.

    NARCIS (Netherlands)

    St Clair Gibson, A; de Koning, J.J.; Thompson, K.G.; Roberts, W.O.; Micklewright, D.; Raglin, J.; Foster, C.

    2013-01-01

    Effective regulation of pace enables the majority of runners to complete competitive endurance events without mishap. However, some runners do experience exercise-induced collapse associated with postural hypotension, which in rare cases results from life-threatening conditions such as cardiac

  18. Effect of increased and maintained frequency of speed endurance training on performance and muscle adaptations in runners

    DEFF Research Database (Denmark)

    Skovgaard, Casper; Almquist, Nicki Winfield; Bangsbo, Jens

    2017-01-01

    The aim of the study was, in runners accustomed to speed endurance training (SET), to examine the effect of increased and maintained frequency of SET on performance and muscular adaptations. After familiarization (FAM) to SET, eighteen male (n=14) and female (n=4) runners (VO2-max: 57.3±3.4 ml...

  19. What are the Differences in Injury Proportions Between Different Populations of Runners? : A Systematic Review and Meta-Analysis

    NARCIS (Netherlands)

    Kluitenberg, Bas; van Middelkoop, Marienke; Diercks, Ron; van der Worp, Henk

    Background Many runners suffer from injuries. No information on high-risk populations is available so far though. Objectives The aims of this study were to systematically review injury proportions in different populations of runners and to compare injury locations between these populations. Data

  20. No effect of a graded training program on the number of running-related injuries in novice runners

    NARCIS (Netherlands)

    Buist, Ida; Bredeweg, Steef W.; van Mechelen, Willem; Lemmink, Koen A. P. M.; Pepping, Gert-Jan; Diercks, Ron L.

    Background: Although running has positive effects on health and fitness, the incidence of a running-related injury (RRI) is high. Research on prevention of RRI is scarce; to date, no studies have involved novice runners. Hypothesis: A graded training program for novice runners will lead to a