Development of a more fish-tolerant turbine runner, advanced hydropower turbine project
International Nuclear Information System (INIS)
Cook, T.C.; Hecker, G.E.
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
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)
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.
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).
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.
Development of a 5kw Francis Turbine Runner Using Computation ...
African Journals Online (AJOL)
First Lady
energy obtained is known as hydro-electric power which is one of the cheapest forms ... Turgo) used for hydropower generation (Sabourin et al., 1996). The Awba ... Function of draft tube is to convert unused kinetic energy at the exit of runner.
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)
Experimental Pressure Measurements on Hydropower Turbine Runners
Energy Technology Data Exchange (ETDEWEB)
Harding, Samuel F.; Richmond, Marshall C.
2017-04-28
The range of hydrodynamic operating conditions to which the turbine is exposed results in significant pressure fluctuations on both the pressure and suction sides of the blades. Understanding these dynamic pressures has a range of applications. Structurally, the resulting dynamic loads are significant in understanding the design life and maintenance schedule of the bearing, shafts and runner components. The pulsing pressures have also been seen to have a detrimental effect on the surface condition of the blades. Biologically, the pressure gradients and pressure extremes are the primary driver of barotrauma for fish passing through hydroturbines. Improvements in computational fluid dynamics (CFD) can be used to simulate such unsteady pressures in the regions of concern. High frequency model scale and prototype measurements of pressures at the blade are important in the validation of these models. Experimental characterization of pressure fields over hydroturbine blades has been demonstrated by a number of studies which using multiple pressure transducers to map the pressure contours on the runner blades. These have been performed at both model and prototype scales, often to validate computational models of the pressure and flow fields over the blades. This report provides a review of existing studies in which the blade pressure was measured in situ. The report assesses the technology for both model and prototype scale testing. The details of the primary studies in this field are reported and used to inform the types of hardware required for similar experiments based on the Ice Harbor Dam owned by the US Corps of Engineers on the Snake River, WA, USA. Such a study would be used to validate the CFD performed for the BioPA.
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
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.
Development of environmentally advanced hydropower turbine system design concepts
International Nuclear Information System (INIS)
Franke, G.F.; Webb, D.R.; Fisher, R.K. Jr.
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
A progress report on DOE's advanced hydropower turbine systems program
International Nuclear Information System (INIS)
Sale, M.J.; Cada, G.F.; Rinehart, B.E.
1997-01-01
Recent hydropower research within the U.S. Department of Energy (DOE) has focused on the development of new turbine designs that can produce hydroelectricity without such adverse environmental affects as fish entrainment/impingement or degradation of water quality. In partnership with the hydropower industry, DOE's advanced turbine program issued a Request for Proposals for conceptual designs in October 1994. Two contracts were awarded for this initial program phase, work on which will be complete this year. A technical advisory committee with representatives from industry, regulatory agencies, and natural resource agencies was also formed to guide the DOE turbine research. The lack of quantitative biological performance criteria was identified by the committee as a critical knowledge gap. To fill this need, a new literature review was completed on the mechanisms of fish mortality during turbine passage (e.g., scrape/strike, shear, press change, etc.), ways that fish behavior affects their location and orientation in turbines, and how these turbine passage stresses can be measured. Thus year, new Laboratory tests will be conducted on fish response to shear, the least-well understood mechanism of stress. Additional testing of conceptual turbine designs depends on the level of federal funding for this program
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
Load variation effects on the pressure fluctuations exerted on a Kaplan turbine runner
International Nuclear Information System (INIS)
Amiri, K; Cervantes, M J; Mulu, B; Raisee, M
2014-01-01
Introduction of intermittent electricity production systems like wind power and solar systems to electricity market together with the consumption-based electricity production resulted in numerous start/stops, load variations and off-design operation of water turbines. The hydropower systems suffer from the varying loads exerted on the stationary and rotating parts of the turbines during load variations which they are not designed for. On the other hand, investigations on part load operation of single regulated turbines, i.e., Francis and propeller, proved the formation of rotating vortex rope (RVR) in the draft tube. The RVR induces oscillating flow both in plunging and rotating modes which results in oscillating force with two different frequencies on the runner blades, bearings and other rotating parts of the turbine. The purpose of this study is to investigate the effect of transient operations on the pressure fluctuations on the runner and mechanism of the RVR formation/mitigation. Draft tube and runner blades of the Porjus U9 model, a Kaplan turbine, were equipped with pressure sensors. The model was run in off-cam mode during different load variation conditions to check the runner performance under unsteady condition. The results showed that the transients between the best efficiency point and the high load happens in a smooth way while transitions to/from the part load, where rotating vortex rope (RVR) forms in the draft tube induces high level of fluctuations with two frequencies on the runner; plunging and rotating mode of the RVR
Load variation effects on the pressure fluctuations exerted on a Kaplan turbine runner
Amiri, K.; Mulu, B.; Raisee, M.; Cervantes, M. J.
2014-03-01
Introduction of intermittent electricity production systems like wind power and solar systems to electricity market together with the consumption-based electricity production resulted in numerous start/stops, load variations and off-design operation of water turbines. The hydropower systems suffer from the varying loads exerted on the stationary and rotating parts of the turbines during load variations which they are not designed for. On the other hand, investigations on part load operation of single regulated turbines, i.e., Francis and propeller, proved the formation of rotating vortex rope (RVR) in the draft tube. The RVR induces oscillating flow both in plunging and rotating modes which results in oscillating force with two different frequencies on the runner blades, bearings and other rotating parts of the turbine. The purpose of this study is to investigate the effect of transient operations on the pressure fluctuations on the runner and mechanism of the RVR formation/mitigation. Draft tube and runner blades of the Porjus U9 model, a Kaplan turbine, were equipped with pressure sensors. The model was run in off-cam mode during different load variation conditions to check the runner performance under unsteady condition. The results showed that the transients between the best efficiency point and the high load happens in a smooth way while transitions to/from the part load, where rotating vortex rope (RVR) forms in the draft tube induces high level of fluctuations with two frequencies on the runner; plunging and rotating mode of the RVR.
Analysis of a pico tubular-type hydro turbine performance by runner blade shape using CFD
Park, J. H.; Lee, N. J.; Wata, J. V.; Hwang, Y. C.; Kim, Y. T.; Lee, Y. H.
2012-11-01
There has been a considerable interest recently in the topic of renewable energy. This is primarily due to concerns about environmental impacts of fossil fuels. Moreover, fluctuating and rising oil prices, increase in demand, supply uncertainties and other factors have led to increased calls for alternative energy sources. Small hydropower, among other renewable energy sources, has been evaluated to have adequate development value because it is a clean, renewable and abundant energy resource. In addition, small hydropower has the advantage of low cost development by using rivers, agricultural reservoirs, sewage treatment plants, waterworks and water resources. The main concept of the tubular-type hydro turbine is based on the difference in water pressure levels in pipe lines, where the energy which was initially wasted by using a reducing valve at the pipeline of waterworks, is collected by turbine in the hydro power generator. In this study, in order to acquire the performance data of a pico tubular-type hydro turbine, the output power, head and efficiency characteristics by different runner blade shapes are examined. The pressure and velocity distributions with the variation of guide vane and runner vane angle on turbine performance are investigated by using a commercial CFD code.
2013-11-29
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project Nos. 14521-001, 14561-000] KC Small Hydro LLC; Advanced Hydropower, Inc.; Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments, Motions To Intervene, and Competing Applications On May 13, 2013, KC Scoby...
Engineering & Performance of DuoTurbo: Microturbine with Counter-Rotating Runners
Biner, D.; Hasmatuchi, V.; Violante, D.; Richard, S.; Chevailler, S.; Andolfatto, L.; Avellan, F.; Münch, C.
2016-11-01
Considering the nuclear phase-out strategy of several European countries and the future tendency to promote renewable energies, the exploitation of small hydropower sites (industrial partners. The modular in-line “plug & play” technology requires low investment, reaching economic feasibility with an available power between 5 kW and 25 kW. One stage of the microturbine consists of two axial counter-rotating runners that form a compact independent unit. Each runner of the turbine holds its own rim generator, the DuoTurbo-configuration involving that each hydraulic runner is integral with each electrical rotor. The possibility of stacking several stages in series enables covering quite a wide range of hydraulic power and, thus, recovering a maximum of energy dissipated in release valves of water supply systems. The present work introduces the global concept of the implemented prototype of the DuoTurbo-microturbine, to target a maximal injected power of 5 kW for a discharge of 9 l/s and a head of 24.5 m per stage. The main features of the hydraulic, the mechanical, the electrical and the electronic design are presented. The hydraulic performance is, then, assessed using CFD simulations for the expected operating range. Finally, the performance measurements of the single-stage prototype installed in the hydraulic test rig of the HES-SO Valais//Wallis are presented.
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.
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....
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.
Hydropower: Partnership with the Environment
Energy Technology Data Exchange (ETDEWEB)
None
2001-06-01
This brochure provides useful information on types of hydroelectric facilities as well as general information on capacity, generation, environmental issues, and advanced conventional hydropower technology within the United States.
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.
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.
International Nuclear Information System (INIS)
Bergant, A; Gregorc, B; Gale, J
2012-01-01
This paper deals with critical flow regimes that may induce unacceptable water hammer in Kaplan turbine hydropower plants. Water hammer analysis should be performed for normal, emergency and catastrophic operating conditions. Hydropower plants with Kaplan turbines are usually comprised of relatively short inlet and outlet conduits. The rigid water hammer theory can be used for this case. For hydropower plants with long penstocks the elastic water hammer should be used. Some Kaplan turbine units are installed in systems with long open channels. In this case, water level oscillations in the channels should be carefully investigated. Computational results are compared with results of measurements in recently rehabilitated seven Drava river hydroelectric power plants in Slovenia. Water hammer in the six power plants is controlled by appropriate adjustment of the wicket gates and runner blades closing/opening manoeuvres. Due to very long inflow and outflow open channels in Zlatolicje HPP a special vaned pressure regulating device attenuates extreme pressures in Kaplan turbine flow-passage system and controls unsteady flow in both open channels. Comparisons of results include normal operating regimes. The agreement between computed and measured results is reasonable.
Bergant, A.; Gregorc, B.; Gale, J.
2012-11-01
This paper deals with critical flow regimes that may induce unacceptable water hammer in Kaplan turbine hydropower plants. Water hammer analysis should be performed for normal, emergency and catastrophic operating conditions. Hydropower plants with Kaplan turbines are usually comprised of relatively short inlet and outlet conduits. The rigid water hammer theory can be used for this case. For hydropower plants with long penstocks the elastic water hammer should be used. Some Kaplan turbine units are installed in systems with long open channels. In this case, water level oscillations in the channels should be carefully investigated. Computational results are compared with results of measurements in recently rehabilitated seven Drava river hydroelectric power plants in Slovenia. Water hammer in the six power plants is controlled by appropriate adjustment of the wicket gates and runner blades closing/opening manoeuvres. Due to very long inflow and outflow open channels in Zlatoličje HPP a special vaned pressure regulating device attenuates extreme pressures in Kaplan turbine flow-passage system and controls unsteady flow in both open channels. Comparisons of results include normal operating regimes. The agreement between computed and measured results is reasonable.
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)
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.
Lower extremity injuries in runners. Advances in prediction.
Macera, C A
1992-01-01
Recreational and competitive running is practised by many individuals to improve cardiorespiratory function and general well-being. The major negative aspect of running is the high rate of injuries to the lower extremities. Several well-designed population-based studies have found no major differences in injury rates between men and women; no increasing effect of age on injuries; a declining injury rate with more years of running experience; no substantial effect of weight or height; an uncertain effect of psychological factors; and a strong effect of previous injury on future injuries. Among the modifiable risk factors studied, weekly distance is the strongest predictor of future injuries. Other training characteristics (speed, frequency, surface, timing) have little or no effect on future injuries after accounting for distance run. More studies are needed to address the effects of appropriate stretching practices and abrupt change in training patterns. For recreational runners who have sustained injuries, especially within the past year, a reduction in running to below 32 km per week is recommended. For those about to begin a running programme, moderation is the best advice. For competitive runners, great care should be taken to ensure that prior injuries are sufficiently healed before attempting any racing event, particularly a marathon.
A Summary of Environmentally Friendly Turbine Design Concepts
Energy Technology Data Exchange (ETDEWEB)
Odeh, Mufeed [United States Geological Survey - BRD, Turners Falls, MA (United States)
1999-07-01
The Advanced Hydropower Turbine System Program (AHTS) was created in 1994 by the U.S. Department of Energy, Electric Power Research Institute, and the Hydropower Research Foundation. The Program’s main goal is to develop “environmentally friendly” hydropower turbines. The Program’s first accomplishment was the development of conceptual designs of new environmentally friendly turbines. In order to do so, two contractors were competitively selected. The ARL/NREC team of engineers and biologists provided a conceptual design for a new turbine runner*. The new runner has the potential to generate hydroelectricity at close to 90% efficiency. The Voith team produced new fish-friendly design criteria for Kaplan and Francis turbines that can be incorporated in units during rehabilitation projects or in new hydroelectric facilities**. These include the use of advanced plant operation, minimum gap runners, placement of wicket gates behind stay vanes, among others. The Voith team will also provide design criteria on aerating Francis turbines to increase dissolved oxygen content. Detailed reviews of the available literature on fish mortality studies, causation of injuries to fish, and available biological design criteria that would assist in the design of fish-friendly turbines were performed. This review identified a need for more biological studies in order to develop performance criteria to assist turbine manufacturers in designing a more fish-friendly turbine.
CSIR Research Space (South Africa)
Jonker Klunne, W
2012-10-01
Full Text Available Hydropower is currently the most common source of renewable energy, accounting for more than 3,400 terawatts, or about 16 percent of global electricity production, in 2010. As hydropower uses a fuel—water from the hydrologic cycle...
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).
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.
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.
International Nuclear Information System (INIS)
Raesaar, Peeter
1997-01-01
Long life practice has proved that small hydropower is not a beaten track in the global energy field. Before the Second World War small hydropower was rather well developed in Estonia as well. Being neglected during the years of Soviet occupation, it is rather important to help it to regain its position in the Estonian energy system once again. Our hydropower potential is not big, but it has got a good established position as an energy saving measure. By now we have some good examples of restored hydropower stations on commercial basis to be optimistic about the future
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).
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.
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.
Research on Darrieus-type hydraulic turbine for extra-low head hydropower utilization
International Nuclear Information System (INIS)
Furukawa, A; Watanabe, S; Okuma, K
2012-01-01
A Darrieus-type turbine has been investigated for extra-low head hydropower utilization. In the present paper, authors'research on Darrieus-type hydraulic turbine is briefly reviewed. The working principle of Darrieus turbine is explained with advantage of its simple structure, at first. Then the fluid-dynamic difference between rotating and linear motions of a blade in a uniform flow is clarified with guiding principle of high performance design of Darrieus turbine. Cavitation problem is also described. Next, effects of duct-casing, consisting of an intake, runner section and draft tube, are discussed and a simplified structure of Darrieus turbine is shown by installing the inlet nozzle. Finally, in the practical use, an adjustment of inlet nozzle section by lowering the inlet nozzle height is proposed when flow rate is varied temporally and seasonally.
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.
Studies on water turbine runner which fish can pass through: In case of single stage axial runner
International Nuclear Information System (INIS)
Shimizu, Yukimari; Maeda, Takao; Nagoshi, Osamu; Ieda, Kazuma; Shinma, Hisako; Hagimoto, Michiko
1994-01-01
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
Small Hydropower - The comeback of small hydropower stations
International Nuclear Information System (INIS)
Niederhaeusern, A.
2008-01-01
This issue of the 'Erneuerbare Energien' (renewable energies) magazine published by the Swiss Solar Energy Society takes a look at small hydropower projects in Switzerland. In a number of interviews and articles, various topics concerning small hydropower are dealt with. First of all, an interview with Bruno Guggisberg, previously responsible for small hydro at the Swiss Federal Office of Energy, examines the potential of small hydro and the various political, technical and economic influences on such projects. Further articles provide an overview of the various types of small hydro schemes, including power generation using height differences in drinking-water and wastewater installations. As far as the components of small hydro schemes are concerned, various types of turbines and further system components that are needed are examined. A further article takes a look at the small hydro market and the market players involved. Ecological aspects and research activities are discussed in further articles. In a second interview with Martin Boelli, presently responsible for small hydropower at the Swiss Federal Office of Energy, the unused potential for the use of hydropower in Switzerland is discussed. Examples of small-scale hydro schemes are examined and the support offered by the Small Hydropower Program is discussed. Finally the question is asked, if the small hydro market in Switzerland is overheated as a result of promotion schemes such as cost-covering remuneration for electricity from renewable energy sources.
Proven but new. Innovation of hydropower
Energy Technology Data Exchange (ETDEWEB)
Harreiter, Herfried [Verbund Hydro Power AG, Vienna (Austria); Godde, Dominik [E.ON Generation GmbH, Hannover (Germany); Zickermann, Richard [ALSTOM (Schweiz) AG, Baden (Switzerland)
2012-07-01
Hydropower has been utilised traditionally and its technology is being further developed and advanced. Current developments are addressed by outlining the challenges for operators and manufacturers. The case examples show a wide range of possible innovations. This refers to single components up to novel overall concepts like hybrid plants and compact turbine plants as well as run-of-river power plants. (orig.)
Renewable Energy Essentials: Hydropower
Energy Technology Data Exchange (ETDEWEB)
NONE
2010-07-01
Hydropower is currently the most common form of renewable energy and plays an important part in global power generation. Worldwide hydropower produced 3 288 TWh, just over 16% of global electricity production in 2008, and the overall technical potential for hydropower is estimated to be more than 16 400 TWh/yr.
Energy Technology Data Exchange (ETDEWEB)
Grether, Stefanie; Graulich, Kathrin; Griesshammer, Rainer
2009-11-20
Top runners - that is, devices with the most efficient advanced technology - are offered by the manufacturers too rare, and are required too little from the consumers. Under this aspect, the project under consideration accompanies scientifically the practical implementation in the preparatory phase of a presumably TopRunner pulse program. In addition, three other objectives are pursued: (1) Development of a product database for top runner products; (2) Construction of a comprehensive power saving brochure for the consumer advice (content and layout); (3) Design of a e-learning concept for power saving advice.
Gastrointestinal disturbances in marathon runners.
Riddoch, C; Trinick, T
1988-06-01
The purpose of this survey was to investigate the prevalence of running-induced gastrointestinal (GI) disturbances in marathon runners. A questionnaire was completed by 471 of the estimated 1,750 competitors in the 1986 Belfast City Marathon. Eighty-three per cent of respondents indicated that they occasionally or frequently suffered one or more GI disturbances during or immediately after running. The urge to have a bowel movement (53%) and diarrhoea (38%) were the most common symptoms, especially among female runners (74% and 68% respectively). Upper GI tract symptoms were experienced more by women than men (p less than 0.05) and more by younger runners than older runners (p less than 0.01). Women also suffered more lower GI tract symptoms than men (p less than 0.05) with younger runners showing a similar trend. Both upper and lower tract symptoms were more common during a "hard" run than an "easy" run (p less than 0.01) and were equally as common both during and after running. Of those runners who suffered GI disturbances, 72% thought that running was the cause and 29% believed their performance to be adversely affected. There was no consensus among sufferers as to the causes of symptoms and a wide variety of "remedies" were suggested. GI disturbances are common amongst long-distance runners and their aetiology is unknown. Medical practitioners should be aware of this when dealing with patients who run.
Hydropower externalities: A meta-analysis
International Nuclear Information System (INIS)
Mattmann, Matteo; Logar, Ivana; Brouwer, Roy
2016-01-01
This paper presents a meta-analysis of existing research related to the economic valuation of the external effects of hydropower. A database consisting of 81 observations derived from 29 studies valuing the non-market impacts of hydropower electricity generation is constructed with the main aim to quantify and explain the economic values for positive and negative hydropower externalities. Different meta-regression model specifications are used to test the robustness of significant determinants of non-market values, including different types of hydropower impacts. The explanatory and predictive power of the estimated models is relatively high. Whilst controlling for sample and study characteristics, we find significant evidence for public aversion towards deteriorations of landscape, vegetation and wildlife caused by hydropower projects. There is however only weak evidence of willingness to pay for mitigating these effects. The main positive externality of hydropower generation, the avoidance of greenhouse gas emission, positively influences welfare estimates when combined with the share of hydropower in national energy production. Sensitivity to scope is detected, but not linked to specific externalities or non-market valuation methods. - Highlights: • A global meta-analysis of valuation studies of hydropower externalities is presented. • Positive and negative externalities are distinguished. • Welfare losses due to environmental deteriorations outweigh gains of GHG reductions. • There is only weak evidence of public WTP for mitigating negative externalities. • The non-market values of hydropower externalities are sensitive to scope.
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.
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.
2013-03-06
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 11169-029] Mayo Hydropower, LLC, Avalon Hydropower, LLC; Notice of Application for Transfer of License, and Soliciting Comments and Motions To Intervene On November 20, 2012, Mayo Hydropower, LLC (transferor) and Avalon Hydropower...
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.
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.
Ankle plantarflexion strength in rearfoot and forefoot runners: a novel clusteranalytic approach.
Liebl, Dominik; Willwacher, Steffen; Hamill, Joseph; Brüggemann, Gert-Peter
2014-06-01
The purpose of the present study was to test for differences in ankle plantarflexion strengths of habitually rearfoot and forefoot runners. In order to approach this issue, we revisit the problem of classifying different footfall patterns in human runners. A dataset of 119 subjects running shod and barefoot (speed 3.5m/s) was analyzed. The footfall patterns were clustered by a novel statistical approach, which is motivated by advances in the statistical literature on functional data analysis. We explain the novel statistical approach in detail and compare it to the classically used strike index of Cavanagh and Lafortune (1980). The two groups found by the new cluster approach are well interpretable as a forefoot and a rearfoot footfall groups. The subsequent comparison study of the clustered subjects reveals that runners with a forefoot footfall pattern are capable of producing significantly higher joint moments in a maximum voluntary contraction (MVC) of their ankle plantarflexor muscles tendon units; difference in means: 0.28Nm/kg. This effect remains significant after controlling for an additional gender effect and for differences in training levels. Our analysis confirms the hypothesis that forefoot runners have a higher mean MVC plantarflexion strength than rearfoot runners. Furthermore, we demonstrate that our proposed stochastic cluster analysis provides a robust and useful framework for clustering foot strikes. Copyright © 2014 Elsevier B.V. All rights reserved.
Assessing Climate Change Impacts on Global Hydropower
Directory of Open Access Journals (Sweden)
Aanund Killingtveit
2012-02-01
Full Text Available Currently, hydropower accounts for close to 16% of the world’s total power supply and is the world’s most dominant (86% source of renewable electrical energy. The key resource for hydropower generation is runoff, which is dependent on precipitation. The future global climate is uncertain and thus poses some risk for the hydropower generation sector. The crucial question and challenge then is what will be the impact of climate change on global hydropower generation and what are the resulting regional variations in hydropower generation potential? This paper is a study that aims to evaluate the changes in global hydropower generation resulting from predicted changes in climate. The study uses an ensemble of simulations of regional patterns of changes in runoff, computed from global circulation models (GCM simulations with 12 different models. Based on these runoff changes, hydropower generation is estimated by relating the runoff changes to hydropower generation potential through geographical information system (GIS, based on 2005 hydropower generation. Hydropower data obtained from EIA (energy generation, national sites, FAO (water resources and UNEP were used in the analysis. The countries/states were used as computational units to reduce the complexities of the analysis. The results indicate that there are large variations of changes (increases/decreases in hydropower generation across regions and even within regions. Globally, hydropower generation is predicted to change very little by the year 2050 for the hydropower system in operation today. This change amounts to an increase of less than 1% of the current (2005 generation level although it is necessary to carry out basin level detailed assessment for local impacts which may differ from the country based values. There are many regions where runoff and hydropower generation will increase due to increasing precipitation, but also many regions where there will be a decrease. Based on this
Trabecular bone in the calcaneus of runners.
Best, Andrew; Holt, Brigitte; Troy, Karen; Hamill, Joseph
2017-01-01
Trabecular bone of the human calcaneus is subjected to extreme repetitive forces during endurance running and should adapt in response to this strain. To assess possible bone functional adaptation in the posterior region of the calcaneus, we recruited forefoot-striking runners (n = 6), rearfoot-striking runners (n = 6), and non-runners (n = 6), all males aged 20-41 for this institutionally approved study. Foot strike pattern was confirmed for each runner using a motion capture system. We obtained high resolution peripheral computed tomography scans of the posterior calcaneus for both runners and non-runners. No statistically significant differences were found between runners and nonrunners or forefoot strikers and rearfoot strikers. Mean trabecular thickness and mineral density were greatest in forefoot runners with strong effect sizes (forefoot strikers, likely an artifact of greater running volume and earlier onset of running in this subgroup; thus, individuals with the greatest summative loading stimulus had, after body mass adjustment, the thickest trabeculae. Further study with larger sample sizes is necessary to elucidate the role of footstrike on calcaneal trabecular structure. To our knowledge, intraspecific body mass correlations with measures of trabecular robusticity have not been reported elsewhere. We hypothesize that early adoption of running and years of sustained moderate volume running stimulate bone modeling in trabeculae of the posterior calcaneus.
Organizing Environmental Flow Frameworks to Meet Hydropower Mitigation Needs
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.
Tapering strategies in elite British endurance runners.
Spilsbury, Kate L; Fudge, Barry W; Ingham, Stephen A; Faulkner, Steve H; Nimmo, Myra A
2015-01-01
The aim of the study was to explore pre-competition training practices of elite endurance runners. Training details from elite British middle distance (MD; 800 m and 1500 m), long distance (LD; 3000 m steeplechase to 10,000 m) and marathon (MAR) runners were collected by survey for 7 days in a regular training (RT) phase and throughout a pre-competition taper. Taper duration was [median (interquartile range)] 6 (3) days in MD, 6 (1) days in LD and 14 (8) days in MAR runners. Continuous running volume was reduced to 70 (16)%, 71 (24)% and 53 (12)% of regular levels in MD, LD and MAR runners, respectively (P training (MD; 53 (45)%, LD; 67 (23)%, MAR; 64 (34)%, P training intensity was above race speed in LD and MAR runners (112 (27)% and 114 (3)%, respectively, P training undertaken prior to the taper in elite endurance runners is predictive of the tapering strategy implemented before competition.
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.
The future of hydropower planning modeling
Haas, J.; Zuñiga, D.; Nowak, W.; Olivares, M. A.; Castelletti, A.; Thilmant, A.
2017-12-01
Planning the investment and operation of hydropower plants with optimization tools dates back to the 1970s. The focus used to be solely on the provision of energy. However, advances in computational capacity and solving algorithms, dynamic markets, expansion of renewable sources, and a better understanding of hydropower environmental impacts have recently led to the development of novel planning approaches. In this work, we provide a review, systematization, and trend analysis of these approaches. Further, through interviews with experts, we outline the future of hydropower planning modeling and identify the gaps towards it. We classified the found models along environmental, economic, multipurpose and technical criteria. Environmental interactions include hydropeaking mitigation, water quality protection and limiting greenhouse gas emissions from reservoirs. Economic and regulatory criteria consider uncertainties of fossil fuel prices and relicensing of water rights and power purchase agreements. Multipurpose considerations account for irrigation, tourism, flood protection and drinking water. Recently included technical details account for sedimentation in reservoirs and variable efficiencies of turbines. Additional operational considerations relate to hydrological aspects such as dynamic reservoir inflows, water losses, and climate change. Although many of the above criteria have been addressed in detail on a project-to-project basis, models remain overly simplistic for planning large power fleets. Future hydropower planning tools are expected to improve the representation of the water-energy nexus, including environmental and multipurpose criteria. Further, they will concentrate on identifying new sources of operational flexibility (e.g. through installing additional turbines and pumps) for integrating renewable energy. The operational detail will increase, potentially emphasizing variable efficiencies, storage capacity losses due to sedimentation, and the
Modeling and dynamic behaviour of hydropower plants
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.
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.
Trabecular bone in the calcaneus of runners.
Directory of Open Access Journals (Sweden)
Andrew Best
Full Text Available Trabecular bone of the human calcaneus is subjected to extreme repetitive forces during endurance running and should adapt in response to this strain. To assess possible bone functional adaptation in the posterior region of the calcaneus, we recruited forefoot-striking runners (n = 6, rearfoot-striking runners (n = 6, and non-runners (n = 6, all males aged 20-41 for this institutionally approved study. Foot strike pattern was confirmed for each runner using a motion capture system. We obtained high resolution peripheral computed tomography scans of the posterior calcaneus for both runners and non-runners. No statistically significant differences were found between runners and nonrunners or forefoot strikers and rearfoot strikers. Mean trabecular thickness and mineral density were greatest in forefoot runners with strong effect sizes (<0.80. Trabecular thickness was positively correlated with weekly running distance (r2 = 0.417, p<0.05 and years running (r2 = 0.339, p<0.05 and negatively correlated with age at onset of running (r2 = 0.515, p<0.01 Trabecular thickness, mineral density and bone volume ratio of nonrunners were highly correlated with body mass (r2 = 0.824, p<0.05 and nonrunners were significantly heavier than runners (p<0.05. Adjusting for body mass revealed significantly thicker trabeculae in the posterior calcaneus of forefoot strikers, likely an artifact of greater running volume and earlier onset of running in this subgroup; thus, individuals with the greatest summative loading stimulus had, after body mass adjustment, the thickest trabeculae. Further study with larger sample sizes is necessary to elucidate the role of footstrike on calcaneal trabecular structure. To our knowledge, intraspecific body mass correlations with measures of trabecular robusticity have not been reported elsewhere. We hypothesize that early adoption of running and years of sustained moderate volume running stimulate bone modeling in trabeculae of the
Fat intake and injury in female runners.
Gerlach, Kristen E; Burton, Harold W; Dorn, Joan M; Leddy, John J; Horvath, Peter J
2008-01-03
Our purpose was to determine the relationship between energy intake, energy availability, dietary fat and lower extremity injury in adult female runners. We hypothesized that runners who develop overuse running-related injuries have lower energy intakes, lower energy availability and lower fat intake compared to non-injured runners. Eighty-six female subjects, running a minimum of 20 miles/week, completed a food frequency questionnaire and informed us about injury incidence over the next year. Injured runners had significantly lower intakes of total fat (63 +/- 20 vs. 80 +/- 50 g/d) and percentage of kilocalories from fat (27 +/- 5 vs. 30 +/- 8 %) compared with non-injured runners. A logistic regression analysis found that fat intake was the best dietary predictor, correctly identifying 64% of future injuries. Lower energy intake and lower energy availability approached, but did not reach, a significant association with overuse injury in this study. Fat intake is likely associated with injury risk in female runners. By documenting these associations, better strategies can be developed to reduce running injuries in women.
Environmental impact of hydropower systems
International Nuclear Information System (INIS)
Malai, Marius
1996-01-01
The installed hydropower potential of Romania is evaluated to 15,700 MW and 42 billion MWh/year power generation. Only 39% of this potential are currently being utilized. In this note, the impact of Somes-Tarnita and Mariselu-Cluj hydropower systems on the environment is presented. Also, the socio-economic effects on the local communities are considered. These two hydropower systems supply a total electric power of 470 GWh/year
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.
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.
US Hydropower Resource Assessment for Massachusetts
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 hydropower 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 Commonwealth of Massachusetts.
The importance of hydropower in Austria
International Nuclear Information System (INIS)
Kobau, R.; Pirker, O.; Spolwind, R.; Weiss, B.
2009-01-01
This article discusses the importance of hydropower-based power generation in Austria as a clean and emission-free source of electricity. The contribution made to total electricity generation is examined and figures are quoted. Hydropower is provided from both storage dams and run-of-river power stations such as those on the river Danube. The use of the various types of hydropower in connection with their economic optimisation, for example for the supply of valuable peak power, is discussed. The promotion of hydropower within the scope of European climate-protection efforts is examined. Projects concerning the augmentation of hydropower capacities are discussed and three exemplary projects are briefly described. Finally, the situation in Austria is compared with that to be found in neighbouring Switzerland.
US hydropower resource assessment for Texas
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 Texas.
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.
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.
Fat intake and injury in female runners
Directory of Open Access Journals (Sweden)
Leddy John J
2008-01-01
Full Text Available Abstract Background Our purpose was to determine the relationship between energy intake, energy availability, dietary fat and lower extremity injury in adult female runners. We hypothesized that runners who develop overuse running-related injuries have lower energy intakes, lower energy availability and lower fat intake compared to non-injured runners. Methods Eighty-six female subjects, running a minimum of 20 miles/week, completed a food frequency questionnaire and informed us about injury incidence over the next year. Results Injured runners had significantly lower intakes of total fat (63 ± 20 vs. 80 ± 50 g/d and percentage of kilocalories from fat (27 ± 5 vs. 30 ± 8 % compared with non-injured runners. A logistic regression analysis found that fat intake was the best dietary predictor, correctly identifying 64% of future injuries. Lower energy intake and lower energy availability approached, but did not reach, a significant association with overuse injury in this study. Conclusion Fat intake is likely associated with injury risk in female runners. By documenting these associations, better strategies can be developed to reduce running injuries in women.
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.
2010-10-21
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. AD09-9-000] Small Hydropower Development in the United States; Notice of Small/Low-Impact Hydropower Webinar October 13, 2010. The Federal Energy Regulatory Commission will host a Small/Low- Impact Hydropower Webinar on November 10, 2010, from...
Hydropower - internalized costs and externalized benefits
International Nuclear Information System (INIS)
Koch, F.H.
2002-01-01
The benefits of hydropower consist of the minimal level of noxious and greenhouse gas emissions, it's energy security from political instability, and its renewable, non-depletable nature. The costs of hydropower consist of negative effects on the river ecosystem and of social changes in communities in the vicinity of large projects. Public awareness of these costs has increased dramatically during the past two decades, and new hydro projects will not get approval unless adequate mitigation measures are taken to avoid, offset, or compensate for adverse environmental and social effects. To a very large extent, the hydropower industry has internalized what were previously social and environmental externalities. However, hydropower operators do not receive any compensation for the benefits, and to date their competitors (coal, natural gas, oil) have not been required to internalize their adverse environmental externalities. (emissions, depletion of supplies, and sometimes dependence on imported primary energy sources). This creates an uneven playing field, and the hydropower industry enthusiastically welcomes a discussion of this issue, and eventually measures to rectify the situation. The IEA Hydropower Agreement has completed a major international study on the environmental and social impacts of hydropower, and one major component of this study was a Life Cycle Assessment and comparison of all the most important electricity generation technologies. (author)
... require a lot of knee bending, such as biking, jumping, or skiing. Runner's knee happens when the ... is out of alignment, activities like running or biking can wear down the cartilage of the kneecap ( ...
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
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.
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.
2011-12-29
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. AD09-9-000] 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 Hydropower Webinar on January 25, 2012, from 12:00 noon to 1:30 p.m...
2011-05-27
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. AD09-9-000] 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 Hydropower Webinar on June 22, 2011, from 12 noon to 1 p.m...
Influence of the rotor-stator interaction on the dynamic stresses of Francis runners
International Nuclear Information System (INIS)
Guillaume, R; Scolaro, D; Deniau, J L; Colombet, C
2012-01-01
Thanks to advances in computing capabilities and Computational Fluid Dynamics (CFD) techniques, it is now possible to calculate realistic unsteady pressure fields in Francis turbines. This paper will explain methods to calculate the structural loads and the dynamic behaviour in order to optimize the turbine design and maximize its reliability and lifetime. Depending on the operating conditions of a Francis turbine, different hydraulic phenomena may impact the mechanical behaviour of the structure. According to their nature, these highly variable phenomena should be treated differently and specifically in order to estimate the potential risks arising on submerged structures, in particular the runner. The operating condition studied thereafter is the point at maximum power with the maximum head. Under this condition, the runner is excited by only one dynamic phenomenon named the Rotor-Stator Interaction (RSI). The origin of the phenomenon is located on the radial gap of the turbine and is the source of pressure fluctuations. A fluid-structure analysis is performed to observe the influence of that dynamic pressure field on the runner behaviour. The first part of the paper deals with the unsteady fluid computation. The RSI phenomenon is totally unsteady so the fluid simulation must take into account the entire machine and its rotation movement, in order to obtain a dynamic pressure field. In the second part of the paper, a method suitable for the RSI study is developed. It is known that the fluctuating pressure in this gap can be described as a sum of spatial components. By evaluating these components in the CFD results and on the scale model, it is possible to assess the relevance of the numerical results on the whole runner. After this step, the numerical pressure field can be used as the dynamic load of the structure. The final part of the paper presentsthe mechanical finite element calculations. A modal analysis of the runner in water and a harmonic analysis of its
New parameters influencing hydraulic runner lifetime
International Nuclear Information System (INIS)
Sabourin, M; Bouffard, D A; Thibault, D; Levesque, M
2010-01-01
Traditionally, hydraulic runner mechanical design is based on calculation of static stresses. Today, validation of hydraulic runner design in terms of reliability requires taking into account the fatigue effect of dynamics loads. A damage tolerant approach based on fracture mechanics is the method chosen by Alstom and Hydro-Quebec to study fatigue damage in runners. This requires a careful examination of all factors influencing material fatigue behavior. Such material behavior depends mainly on the chemical composition, microstructure and thermal history of the component, and on the resulting residual stresses. Measurement of fracture mechanics properties of various steels have demonstrated that runner lifetime can be significantly altered by differences in the manufacturing process, although remaining in accordance with agreed practices and standards such as ASTM. Carbon content and heat treatment are suspected to influence fatigue lifetime. This will have to be investigated by continuing the current research.
New parameters influencing hydraulic runner lifetime
Energy Technology Data Exchange (ETDEWEB)
Sabourin, M; Bouffard, D A [Alstom Hydro Canada Inc, Hydraulic Engineering, 1350 chemin St-Roch, Sorel-Tracy (Quebec), J3P 5P9 (Canada); Thibault, D [Hydro-Quebec, Institut de Recherche d' Hydro-Quebec 1800 boul. Lionel-Boulet, Varennes (Quebec), J3X 1S1 (Canada); Levesque, M, E-mail: michel.sabourin@power.alstom.co [Ecole Polytechnique de Montreal, Departement de genie mecanique C.P.6079, succ. Centre-ville, Montreal (Quebec), H3C 3A7 (Canada)
2010-08-15
Traditionally, hydraulic runner mechanical design is based on calculation of static stresses. Today, validation of hydraulic runner design in terms of reliability requires taking into account the fatigue effect of dynamics loads. A damage tolerant approach based on fracture mechanics is the method chosen by Alstom and Hydro-Quebec to study fatigue damage in runners. This requires a careful examination of all factors influencing material fatigue behavior. Such material behavior depends mainly on the chemical composition, microstructure and thermal history of the component, and on the resulting residual stresses. Measurement of fracture mechanics properties of various steels have demonstrated that runner lifetime can be significantly altered by differences in the manufacturing process, although remaining in accordance with agreed practices and standards such as ASTM. Carbon content and heat treatment are suspected to influence fatigue lifetime. This will have to be investigated by continuing the current research.
Liao, Tzu-Chieh; Keyak, Joyce H; Powers, Christopher M
2018-02-27
The purpose of this study is to determine whether recreational runners with patellofemoral pain (PFP) exhibit greater peak patella cartilage stress compared to pain-free runners. A secondary purpose was to determine the kinematic and/or kinetic predictors of peak patella cartilage stress during running. Twenty-two female recreational runners participated (12 with PFP and 10 pain-free controls). Patella cartilage stress profiles were quantified using subject-specific finite element models simulating the maximum knee flexion angle during stance phase of running. Input parameters to the finite element model included subject-specific patellofemoral joint geometry, quadriceps muscle forces, and lower extremity kinematics in the frontal and transverse planes. Tibiofemoral joint kinematics and kinetics were quantified to determine the best predictor of stress using stepwise regression analysis. Compared to the pain-free runners, those with PFP exhibited greater peak hydrostatic pressure (PFP vs. control, 21.2 ± 5.6 MPa vs. 16.5 ± 4.6 MPa) and maximum shear stress (11.3 ± 4.6 MPa vs. 8.7 ± 2.3 MPa). Knee external rotation was the best predictor of peak hydrostatic pressure and peak maximum shear stress (38% and 25% of variances, respectively) followed by the knee extensor moment (21% and 25% of variances, respectively). Runners with PFP exhibit greater peak patella cartilage stress during running compared to pain-free individuals. The combination of knee external rotation and a high knee extensor moment best predicted elevated peak stress during running.
Hydropower's role in delivering sustainability
International Nuclear Information System (INIS)
Altinbilek, D.; Seelos, K.; Taylor, R.
2005-01-01
Johannesburg's World Summit on Sustainable Development stipulated in its Implementation Plan that hydropower of all scales should be included in the drive to increase the contribution of renewable energy. This can be achieved through the plant-life extension and upgrading of existing schemes as well as by the sustainable development of new projects according to the needs, opportunities and resources available. Hydropower is the world's largest source of renewable energy used for power generation; it accounts for 19 percent of the world's supply (by 2010 wind power is expected to contribute 0.6 percent and solar power 0.12 percent. Hydropower is also a truly global resource, as more than 150 countries generate hydroelectric power. There is about 730 GW of hydro capacity in operation worldwide, generating 2650 TWh/year. A further 101 GW is under construction and 338 GW is at the planning stage. Hydropower plays an important role in reducing global GhG emissions by an estimated 10 percent per annum; in its current role, hydropower offsets 4.4 million barrels of oil-equivalent (thermal electric generation) each day. There is vast unexploited potential worldwide for new hydro plants, with only 33 percent of the economic potential having been developed so far. The majority of the remaining potential exists in lesser developed countries in Asia, South America and Africa. For example, Europe has developed 75 percent of its economic potential, whereas Africa has only developed seven percent. Hydropower technologies are reliable, advanced and efficient. The energy conversion efficiency of 80 to 93 percent is far higher than that for other major types of power plant. The level of service from the various types of hydro scheme varies from base-load supply, typically from run-of-river schemes, to peak-load and system-back-up services from hydro storage schemes. In regions where there is long-developed hydro capacity, plant-life extension can be achieved by the replacement of
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
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.
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)
Pheakdey, Heng
2017-01-01
To solve its chronic power shortage, the Government of Cambodia has placed the development of hydropower as one of the national priorities. With a total of US$2.4bn in investment, China is the most prominent player in hydropower development in Cambodia. The increase of hydropower projects and
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)
China's rising hydropower demand challenges water sector
Liu, Junguo; Zhao, Dandan; Gerbens-Leenes, Winnie; Guan, Dabo
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
Land Systems Impacts of Hydropower Development
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
Hydropower: Setting a Course for Our Energy Future
Energy Technology Data Exchange (ETDEWEB)
2004-07-01
Hydropower is an annual publication that provides an overview of the Department of Energy's Hydropower Program. The mission of the program is to conduct research and development that will increase the technical, societal, and environmental benefits of hydropower and provide cost-competitive technologies that enable the development of new and incremental hydropower capacity.
Development potential for hydropower
International Nuclear Information System (INIS)
Laufer, F.; Groetzinger, S.; Peter, M.; Schmutz, A.
2004-11-01
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
Infectious episodes in runners before and after a roadrace.
Nieman, D C; Johanssen, L M; Lee, J W
1989-09-01
Various researchers have implied that regular and moderate exercise training may improve the ability of the immune system to protect the host from infection. In contrast, acute, maximal, and exhaustive exercise may have negative effects of the immune system. This study compared the incidence of infectious episodes in 273 runners during a two month training period prior to a 5 K, 10 K, or half-marathon race. In addition, the effect of the race experience on infectious episodes was studied. Twenty-five percent of the runners training more than 15 miles per week reported at least one infectious episode as compared with 34.3% of runners training less than 15 miles per week (p = 0.09). Only 6.8% of the runners preparing for the half-marathon race reported becoming sick with the flu versus 17.9% of the 5 K and 10 K runners (p = 0.067). During the week following the roadrace, runners did not report an increase in infectious episodes as compared to the week prior to the race. These trends suggest that runners with a more serious commitment to regular exercise may experience less infectious episodes than recreational runners because of both direct and indirect affects on immunosurveillance. In addition, the stressful race experience does not appear to increase risk of acquiring an acute respiratory infection.
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.
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.
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.
Multi-objective shape optimization of runner blade for Kaplan turbine
International Nuclear Information System (INIS)
Power machines LMZ, Saint Petersburg (Russian Federation))" data-affiliation=" (OJSC Power machines LMZ, Saint Petersburg (Russian Federation))" >Semenova, A; Power machines LMZ, Saint Petersburg (Russian Federation))" data-affiliation=" (OJSC Power machines LMZ, Saint Petersburg (Russian Federation))" >Pylev, I; Chirkov, D; Lyutov, A; Chemy, S; Skorospelov, V
2014-01-01
Automatic runner shape optimization based on extensive CFD analysis proved to be a useful design tool in hydraulic turbomachinery. Previously the authors developed an efficient method for Francis runner optimization. It was successfully applied to the design of several runners with different specific speeds. In present work this method is extended to the task of a Kaplan runner optimization. Despite of relatively simpler blade shape, Kaplan turbines have several features, complicating the optimization problem. First, Kaplan turbines normally operate in a wide range of discharges, thus CFD analysis of each variant of the runner should be carried out for several operation points. Next, due to a high specific speed, draft tube losses have a great impact on the overall turbine efficiency, and thus should be accurately evaluated. Then, the flow in blade tip and hub clearances significantly affects the velocity profile behind the runner and draft tube behavior. All these features are accounted in the present optimization technique. Parameterization of runner blade surface using 24 geometrical parameters is described in details. For each variant of runner geometry steady state three-dimensional turbulent flow computations are carried out in the domain, including wicket gate, runner, draft tube, blade tip and hub clearances. The objectives are maximization of efficiency in best efficiency and high discharge operation points, with simultaneous minimization of cavitation area on the suction side of the blade. Multiobjective genetic algorithm is used for the solution of optimization problem, requiring the analysis of several thousands of runner variants. The method is applied to optimization of runner shape for several Kaplan turbines with different heads
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.
Multi-objective shape optimization of runner blade for Kaplan turbine
Semenova, A.; Chirkov, D.; Lyutov, A.; Chemy, S.; Skorospelov, V.; Pylev, I.
2014-03-01
Automatic runner shape optimization based on extensive CFD analysis proved to be a useful design tool in hydraulic turbomachinery. Previously the authors developed an efficient method for Francis runner optimization. It was successfully applied to the design of several runners with different specific speeds. In present work this method is extended to the task of a Kaplan runner optimization. Despite of relatively simpler blade shape, Kaplan turbines have several features, complicating the optimization problem. First, Kaplan turbines normally operate in a wide range of discharges, thus CFD analysis of each variant of the runner should be carried out for several operation points. Next, due to a high specific speed, draft tube losses have a great impact on the overall turbine efficiency, and thus should be accurately evaluated. Then, the flow in blade tip and hub clearances significantly affects the velocity profile behind the runner and draft tube behavior. All these features are accounted in the present optimization technique. Parameterization of runner blade surface using 24 geometrical parameters is described in details. For each variant of runner geometry steady state three-dimensional turbulent flow computations are carried out in the domain, including wicket gate, runner, draft tube, blade tip and hub clearances. The objectives are maximization of efficiency in best efficiency and high discharge operation points, with simultaneous minimization of cavitation area on the suction side of the blade. Multiobjective genetic algorithm is used for the solution of optimization problem, requiring the analysis of several thousands of runner variants. The method is applied to optimization of runner shape for several Kaplan turbines with different heads.
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.
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.
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...... and migration studies as well as practical considerations for the use of autoethnography in psychological research and practice.......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....... From there, we continue with a Heideggerian existential-phenomenological analysis of the ‘boundary situation’ when the project of competitive running is challenged due to environmental and cultural barriers in the migration. Our empirical inquiry is based on the first author's autoethnographic account...
International Nuclear Information System (INIS)
Piro, P.
2010-01-01
On average the hydro-power sector produces 12% of the electrical power in France. A quarter of this production might pass to another operator than EDF because the end of some grants is nearing (2012 for 12 installations). In France the power of rivers belongs to the state that gives operators grants to harness it. The allowance lasts 75 years usually but for installations below 4.5 MW a permanent and definitive grant is allowed. Most installations are ancient and their investment have been paid off since a long, so hydro-power is the most profitable renewable energy in France. A lot of bidders are expected. Each bid will be assessed on 3 criteria: -) the global energy efficiency of the waterfall, -) a balanced management of the water resource, and -) an economic and financial offer to the state. The balance between the different uses of water is getting more delicate to reach and this renewal of grants will be an opportunity for the state to impose a better preservation of the environment. In July 2008, the French government announced a program for the re launching of the hydro-power, this program has been reduced and now only 3000 GWh supplementary are expected by 2020. (A.C.)
Hydropower development trends from a technological paradigm perspective
International Nuclear Information System (INIS)
Xu, Jiuping; Ni, Ting; Zheng, Bobo
2015-01-01
Highlights: • We propose a novel concept of hydropower development technological paradigm. • We create a data analysis system to visualize the keyword foci. • Future trajectories include hybrid power systems and resources from seawater. • The HDTP consists of a three-stage evolution and a policy framework. • The HDTP provides a how-to-do solution for the soft path. - Abstract: Hydropower has long been considered the backbone of the power generation sector in low-carbon and sustainable energy systems. Yet, as reliance on hydropower has been generally declining, the world is awakening to the need to fundamentally rethink the way hydropower is developed and managed. The paper proposes a systematic methodology to research the development trends and find a more sustainable hydropower path. Literature mining using the data analysis system and the technological paradigm theory were adopted to conduct the research. The keyword visualization results were found to meet the laws for the three phases of the technological paradigm. Specific key areas, such as small hydropower plants, hybrid power systems, and hydropower from seawater were identified as past, present and near future trajectories. To further accelerate hydropower development, specific subsidies and incentives need to be provided in areas such as capital costs and technological support. The study paves the way for a soft path solution which complements the hard path in hydropower field
China's rising hydropower demand challenges water sector.
Liu, Junguo; Zhao, Dandan; Gerbens-Leenes, P W; Guan, Dabo
2015-07-09
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 based on data from 875 representative reservoirs (209 with power plants). In 2010, the reservoir WF totaled 27.9 × 10(9) m(3) (Gm(3)), or 22% of China's total water consumption. Ignoring the reservoir WF seriously underestimates human water appropriation. The reservoir WF associated with industrial, domestic and agricultural WFs caused water scarcity in 6 of the 10 major Chinese river basins from 2 to 12 months annually. The hydropower WF was 6.6 Gm(3) yr(-1) or 3.6 m(3) of water to produce a GJ (10(9) J) of electricity. Hydropower is a water intensive energy carrier. As a response to global climate change, the Chinese government has promoted a further increase in hydropower energy by 70% by 2020 compared to 2012. This energy policy imposes pressure on available freshwater resources and increases water scarcity. The water-energy nexus requires strategic and coordinated implementations of hydropower development among geographical regions, as well as trade-off analysis between rising energy demand and water use sustainability.
Hydropower externalities: a meta analysis
Mattmann, M.; Logar, I.; Brouwer, R.
2016-01-01
This paper presents a meta-analysis of existing research related to the economic valuation of the external effects of hydropower. A database consisting of 81 observations derived from 29 studies valuing the non-market impacts of hydropower electricity generation is constructed with the main aim to
Mini and micro hydropower systems in India
International Nuclear Information System (INIS)
Kothari, D.P.
1992-01-01
Hydropower is one of the renewable sources of energy. In the field of hydropower, even though small/mini/micro hydropower systems make fractional increases in the overall energy production, their impact on the local areas in which they are sited can be significant in stimulating growth of rural industry and in meeting the basic energy needs of the local population for domestic and agricultural use. They also help in reducing demand on other non-renewable polluting resources like fossil fuels. Moreover as compared to big hydropower systems, small hydropower systems are cost competitive and minimally disruptive to the environment. They require less time for construction and reduce transmission losses. They can be designed to suit the limits of water resources available and can be tailored to the needs of the end-use market. Aspects of small hydropower projects which needs to be studied are listed. Modelling of turbines and generators for such projects, and factors to be considered in selection of suitable turbine and generator for a particular small hydropower system are discussed. The technology for small hydropower systems is well developed and available in India. The present estimated potential of such systems in India is 5000 MW out of which 207 MW is harnessed. These small hydropower plants are mostly located in the northern states like Jammu and Kashmir, Uttar Pradesh, Punjab, and Rajasthan. Construction works for 234 MW at 88 sites are going on. During the 8th plan period, 218.5 MW is planned to be developed with an outlay of Rs. 548.25 crores. It is suggested that special subsidies and liberal term loans should be made available for implementing such systems. (M.G.B.). 8 refs., 2 tabs., 1 fig
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.
Prescribed and self-reported seasonal training of distance runners.
Hewson, D J; Hopkins, W G
1995-12-01
A survey of 123 distance-running coaches and their best runners was undertaken to describe prescribed seasonal training and its relationship to the performance and self-reported training of the runners. The runners were 43 females and 80 males, aged 24 +/- 8 years (mean +/- S.D.), training for events from 800 m to the marathon, with seasonal best paces of 86 +/- 6% of sex- and age-group world records. The coaches and runners completed a questionnaire on typical weekly volumes of interval and strength training, and typical weekly volumes and paces of moderate and hard continuous running, for build-up, pre-competition, competition and post-competition phases of a season. Prescribed training decreased in volume and increased in intensity from the build-up through to the competition phase, and had similarities with 'long slow distance' training. Coaches of the faster runners prescribed longer build-ups, greater volumes of moderate continuous running and slower relative paces of continuous running (r = 0.19-0.36, P training close to competition pace. The mean training volumes and paces prescribed by the coaches were similar to those reported by the runners, but the correlations between prescribed and reported training were poor (r = 0.2-0.6). Coaches may therefore need to monitor their runners' training more closely.
Hydrodynamics automatic optimization of runner blades for reaction hydraulic turbines
Balint, D.; Câmpian, V.; Nedelcu, D.; Megheles, O.
2012-11-01
The aim of this paper is to optimize the hydrodynamics of the runner blades of hydraulic turbines. The runner presented is an axial Kaplan one, but the methodology is common also to Francis runners. The whole methodology is implemented in the in-house software QTurbo3D. The effect of the runner blades geometry modification upon its hydrodynamics is shown both from energetic and cavitation points of view.
Hydrodynamics automatic optimization of runner blades for reaction hydraulic turbines
International Nuclear Information System (INIS)
Balint, D; Câmpian, V; Nedelcu, D; Megheles, O
2012-01-01
The aim of this paper is to optimize the hydrodynamics of the runner blades of hydraulic turbines. The runner presented is an axial Kaplan one, but the methodology is common also to Francis runners. The whole methodology is implemented in the in-house software QTurbo3D. The effect of the runner blades geometry modification upon its hydrodynamics is shown both from energetic and cavitation points of view.
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.
Critical evaluation of the hydropower applications in Greece
Energy Technology Data Exchange (ETDEWEB)
Kaldellis, J.K. [Laboratory of Soft Energy Applications and Environmental Protection, TEI Piraeus, P.O. Box 41046, Athens 12201 (Greece)
2008-01-15
Hydropower is a proven technology for electricity generation, contributing with almost 20% to the fulfilment of the planet electricity demand. Hydropower is also renewable because it draws its essential energy from the sun and particularly from the hydrological cycle. Greece and more precisely the west and north part of the mainland possesses significant hydropower potential that is up to now partially exploited. In the present survey, one investigates the existing situation concerning the applications of hydropower plants in Greece, while the results obtained are compared with the corresponding international and European situation. Subsequently, emphasis is laid on estimating the electricity-generation utilization degree of the existing large hydropower stations, using 25-year long official data. The results obtained underline the fact that the electricity generation is not a priority for the national water management policy and most Greek hydropower stations are used mainly to meet the corresponding peak load demand. On the other hand, increased interest to create numerous new small hydropower plants throughout Greece has been expressed during the last 5 years. According to the information gathered and analyzed, one may state that the available local hydropower potential is quite promising and can substantially contribute to the accomplishment of the national-EU target to cover the 21% of the corresponding electricity consumption from renewable resources. For this purpose one should first define an approved and rational water resources management plan and secondly support the increased utilization of large and small hydropower plants for electricity generation. In this case, properly designed hydropower plants should lead to considerable profits, contributing also in the country's independency from imported oil and accomplishing the Kyoto protocol obligations. (author)
Evaluation of economic rent of hydropower projects
International Nuclear Information System (INIS)
Shrestha, Ram M.; Abeygunawardana, A.M.A.K.
2009-01-01
Existing studies have mostly estimated the ex post economic rent of hydropower for the hydroelectric system of a province or a country as a whole and have ignored the site- or project-specific variations in the economic rent of hydropower plants. Further, most of the existing studies have used simplified methods to calculate the rent ex post. This paper presents a rigorous methodology for estimation of site-specific (i.e., project specific) economic rent of hydropower ex ante. It applies the methodology in the case of a hydropower project and analyzes the sensitivity of the rent to variations in some key parameters.
Minimizing water consumption when producing hydropower
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
Hydro-power: a long history, a bright future
Energy Technology Data Exchange (ETDEWEB)
Deudney, D
1981-07-01
A brief history of the spread of hydro-power in the world was given. Tables showing hydro-power potential and use, and the % electricity from hydro-power for 13 countries were included along with a graph showing % hydro-power operating, planned and under construction by region. The need for committed and farsighted political leadership for future development and the possibility of hydro production reaching 4 to 6 times its present level were discussed.
Climate Risk in Southern and Eastern Africa's Hydropower Generation
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.
Hydropower engineering. Paper no. IGEC-1-005
International Nuclear Information System (INIS)
Cervantes, M.
2005-01-01
Hydropower, one of the corner stones of sustainable energy development, is the largest renewable source of energy. There is a large demand worldwide for people trained to design, operate, maintain and optimise hydropower systems. Hydro Power University, a name which encompasses both education, research and development within hydropower in Sweden, offers a unique and broad international masters programme within hydropower engineering including civil, mechanical and electrical engineering. The programme is the result of a close collaboration between Lulea University of Technology and Uppsala University, at the research and education level. This master programme, Hydropower Engineering, is open to both Swedish and foreign students free of charge. It aims to provide students with state of the art knowledge and experience on parts of the hydropower system such as turbine technology, generator design, rotor dynamics, tribology, dams/dam safety, maintenance and operation and environmental aspects. World unique laboratory experiments are offered to the students at Porjus and Alvkarleby, Sweden. The Porjus Hydropower Centre offers world unique facilities: two full scale turbines of 10 MW each, one with the latest generator technology - Powerformer. The turbines are exclusively dedicated for use in education, research and development. State of the art in measurement technology is available. Both units are at the centre of each education programme offered by the Hydro Power University. In Alvkarleby, spillways, discharge capacity and turbines model testing can be undertaken at the Vattenfall laboratory also with state of the art experimental material and highly qualified staff. The large number of applications from developing countries indicates a need of scholarships, which needs to be resolved for the development of hydropower. (author)
Dynamic behaviour of pump-turbine runner: From disk to prototype runner
International Nuclear Information System (INIS)
Huang, X X; Egusquiza, E; Valero, C; Presas, A
2013-01-01
In recent decades, in order to increase output power of hydroelectric turbomachinery, the design head and the flow rate of the hydraulic turbines have been increased greatly. This has led to serious vibratory problems. The pump-turbines have to work at various operation conditions to satisfy the requirements of the power grid. However, larger hydraulic forces will result in high vibration levels on the turbines, especially, when the machines operate at off-design conditions. Due to the economic considerations, the pump-turbines are built as light as possible, which will change the dynamic response of the structures. According to industrial cases, the fatigue damage of the pump-turbine runner induced by hydraulic dynamic forces usually happens on the outer edge of the crown, which is near the leading edges of blades. To better understand the reasons for this kind of fatigue, it is extremely important to investigate the dynamic response behaviour of the hydraulic turbine, especially the runner, by experimental measurement and numerical simulation. The pump-turbine runner has a similar dynamic response behaviour of the circular disk. Therefore, in this paper the dynamic response analyses for circular disks with different dimensions and disk-blades-disk structures were carried out to better understand the fundamental dynamic behaviour for the complex turbomachinery. The influences of the pattern and number of blades were discussed in detail
KINEMATIC CHANGES DURING A MARATHON FOR FAST AND SLOW RUNNERS
Directory of Open Access Journals (Sweden)
Maggie Chan-Roper
2012-03-01
Full Text Available The purpose of this study was to describe kinematic changes that occur during an actual marathon. We hypothesized that (1 certain running kinematic measures would change between kilometres 8 and 40 (miles 5 and 25 of a marathon and (2 fast runners would demonstrate smaller changes than slow runners. Subjects (n = 179 were selected according to finish time (Range = 2:20:47 to 5:30:10. Two high-speed cameras were used to measure sagittal-plane kinematics at kilometres 8 and 40 of the marathon. The dependent variables were stride length, contact time, peak knee flexion during support and swing, and peak hip flexion and extension during swing. Two-tailed paired t-tests were used to compare dependent variables between kilometres 8 and 40 for all subjects, and regression analyses were used to determine whether faster runners exhibited smaller changes (between miles 5 and 25 than slower runners. For all runners, every dependent variable changed significantly between kilometres 8 and 40 (p < 0.001. Stride length increased 1.3%, contact time increased 13.1%, peak knee flexion during support decreased 3.2%, and peak hip extension, knee flexion, and hip flexion during swing decreased 27.9%, increased 4.3%, and increased 7.4%, respectively (p < 0.001. Among these significant changes, all runners generally changed the same from kilometres 8 and 40 except that fast runners decreased peak knee flexion during support less than the slow runners (p < 0.002. We believe that these changes, for all runners (fast and slow, were due to fatigue. The fact that fast runners maintained knee flexion during support more consistently might be due to their condition on the race day. Strengthening of knee extensor muscles may facilitate increased knee flexion during support throughout a marathon
Prospective comparison of running injuries between shod and barefoot runners.
Altman, Allison R; Davis, Irene S
2016-04-01
Advocates of barefoot running suggest that it is more natural and may be a way to minimise injury risk. In contrast, opponents believe shoes are needed to adequately cushion and support the foot. However, to date, there have been no prospective studies of injury patterns in barefoot and shod runners. The purpose of this study was to compare the incidence and rate of injuries between shod and barefoot runners. A prospective survey was conducted over the course of a year among 201 (107 barefoot and 94 shod) adult runners. Information regarding injuries and mileage was logged monthly using a custom, web-based database program. The number of injured runners, number of injuries per runner and injury rates were compared between habitual barefoot and habitual shod runners. Both musculoskeletal and plantar surface injuries were assessed. Statistically fewer overall, diagnosed, musculoskeletal injuries/runner were noted in the barefoot group. However, injury rates were not statistically different between groups due to significantly less mileage run in the barefoot group. As expected, barefoot runners sustained a statistically greater number of injuries to the plantar surface of the foot. The descriptive analysis suggests a greater number of calf injuries, but lower number of knee and hip injuries in the barefoot group. Additionally barefoot runners reported less plantar fasciitis than the shod group. Barefoot running is associated with fewer overall musculoskeletal injuries/runner, but similar injury rates. A larger scale cohort is needed to more accurately assess differences in individual injuries between these two groups. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Excellent results for CERN runners
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...
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.
Health implications of hydropower development
International Nuclear Information System (INIS)
Biswas, A.K.
1982-01-01
Hydropower development had been neglected in many countries during the past few decades, but the situation dramatically changed during the 1970s owing to the constantly increasing costs of electricity generation by fossil-fuel and nuclear power plants. Currently, hydroelectric generation accounts for approximately 23% of total global electricity supply. Much of the hydropower potential in developing countries of Africa, Asia and Latin America still remains to be exploited. Like any other source of energy, hydropower development has several health impacts. Conceptually, health implications of hydropower development can be divided into two broad categories: short-term and long-term problems. Short-term health impacts occur during the planning, construction and immediate post-construction phases, whereas long-term impacts stem from the presence of large man-made lakes, development of extensive canal systems, alteration of the ecosystem of the area, and changing socio-economic conditions. Longer-term impacts are further classified into two categories: introduction of new diseases and/or intensification of existing ones due to the improvements of the habitats of disease-carrying vectors, and health problems arising from resettlement of the people whose homes and land-holdings are inundated by the reservoirs. All these impacts are discussed in detail. Health impacts of hydropower developments have not yet been studied extensively. It is often implicitly assumed that health impacts of major dams are minor compared with other social and environmental impacts. Future studies could possibly reverse this assumption. (author)
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.
Risk management of hydropower development in China
International Nuclear Information System (INIS)
Tang, Wenzhe; Li, Zhuoyu; Qiang, Maoshan; Wang, Shuli; Lu, Youmei
2013-01-01
There is a rapidly increasing demand for hydropower in China. However, little research has been conducted to systematically investigate the overall aspects of hydropower development risks. With support of the data collected from a fieldwork survey, this study reports the multiple facets of hydropower development risks in China as perceived by main project participants. All groups have a common view on the criticality of safety, and the groups also have their own priorities, i.e., resettlement of migrants, incompetence of subcontractors, project delay, inadequate or incorrect design, premature failure of facilities and ecological and environmental impacts are the key risks to clients, whereas quality of work, financial related risks, reputation, and claims and disputes are the main concerns to contractors. A case study of Three Gorges Project further demonstrates that, hydropower development risks can be effectively managed by encouraging joint efforts of all participants to achieve the goals on producing renewable energy, reducing emissions of CO 2 , and providing important social/economical benefits. Future hydropower development should emphasize the interactions between project delivery, environmental, and economical processes to reach appropriate trade-offs among involving stakeholders, by adequately considering the inter-relations between project participants' risks as well as hydropower project's externalities on a broad view. - Highlights: • Largely attributed to unforeseen geology conditions, safety is critical in hydropower development. • Resettlement of migrants is the principal risk to clients, whereas quality of works is the first concern to contractors. • One group's risks are typically related to others', needing collaborative risk management by participants. • Three Gorges Project plays a key role on producing renewable energy, and providing social/economical benefits. • Hydropower development should emphasize the interactions between
Gender differences in gait kinematics in runners with iliotibial band syndrome.
Phinyomark, A; Osis, S; Hettinga, B A; Leigh, R; Ferber, R
2015-12-01
Atypical running gait biomechanics are considered a primary factor in the etiology of iliotibial band syndrome (ITBS). However, a general consensus on the underpinning kinematic differences between runners with and without ITBS is yet to be reached. This lack of consensus may be due in part to three issues: gender differences in gait mechanics, the preselection of discrete biomechanical variables, and/or relatively small sample sizes. Therefore, this study was designed to address two purposes: (a) examining differences in gait kinematics for male and female runners experiencing ITBS at the time of testing and (b) assessing differences in gait kinematics between healthy gender- and age-matched runners as compared with their ITBS counterparts using waveform analysis. Ninety-six runners participated in this study: 48 ITBS and 48 healthy runners. The results show that female ITBS runners exhibited significantly greater hip external rotation compared with male ITBS and female healthy runners. On the contrary, male ITBS runners exhibited significantly greater ankle internal rotation compared with healthy males. These results suggest that care should be taken to account for gender when investigating the biomechanical etiology of ITBS. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
75 FR 16456 - Inglis Hydropower, LLC; Notice Soliciting Scoping Comments
2010-04-01
... Hydropower, LLC; Notice Soliciting Scoping Comments March 26, 2010. Take notice that the following...: Inglis Hydropower, LLC. e. Name of Project: Inglis Hydropower Project. f. Location: The proposed project... Commission staff intends to prepare a single Environmental Assessment (EA) for the Inglis Hydropower Project...
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.
Resource and utilization of Estonian hydropower
International Nuclear Information System (INIS)
Raesaar, P.
2005-01-01
An overview of the Estonian hydropower resources and their utilization at present as well as prospective for the future are presented in this paper. A short overview of advantages of small hydropower stations and related issues is given. Some technological aspects are treated briefly. (authors)
Low-head hydropower impacts on steam dissolved oxygen
International Nuclear Information System (INIS)
Thene, J.R.; Stefan, H.G.; Daniil, E.I.
1989-01-01
A method to evaluate the effect of hydropower development on downstream dissolved oxygen (DO) is presented for a low head dam. Water, previously aerated during release over spillways and under gates, is diverted through the hydropower facility without further aeration. The oxygen transfer that occurs as a result of air entrainment at the various release points of a dam is measured. Oxygen transfer efficiencies are calculated and incorporated into an oxygen transfer model to predict average release DO concentrations. This model is used to systematically determine the effect of hydropower operation on downstream DO. Operational alternatives are investigated and a simple operational guide is developed to mitigate the effects of hydropower operation. Combinations of reduced generation and optimal releases from the dam allow the hydropower facility to operate within DO standards
Cost of enlarged operating zone for an existing Francis runner
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
Efficient runner safety assessment during early design phase and root cause analysis
International Nuclear Information System (INIS)
Liang, Q W; Lais, S; Gentner, C; Braun, O
2012-01-01
Fatigue related problems in Francis turbines, especially high head Francis turbines, have been published several times in the last years. During operation the runner is exposed to various steady and unsteady hydraulic loads. Therefore the analysis of forced response of the runner structure requires a combined approach of fluid dynamics and structural dynamics. Due to the high complexity of the phenomena and due to the limitation of computer power, the numerical prediction was in the past too expensive and not feasible for the use as standard design tool. However, due to continuous improvement of the knowledge and the simulation tools such complex analysis has become part of the design procedure in ANDRITZ HYDRO. This article describes the application of most advanced analysis techniques in runner safety check (RSC), including steady state CFD analysis, transient CFD analysis considering rotor stator interaction (RSI), static FE analysis and modal analysis in water considering the added mass effect, in the early design phase. This procedure allows a very efficient interaction between the hydraulic designer and the mechanical designer during the design phase, such that a risk of failure can be detected and avoided in an early design stage.The RSC procedure can also be applied to a root cause analysis (RCA) both to find out the cause of failure and to quickly define a technical solution to meet the safety criteria. An efficient application to a RCA of cracks in a Francis runner is quoted in this article as an example. The results of the RCA are presented together with an efficient and inexpensive solution whose effectiveness could be proven again by applying the described RSC technics. It is shown that, with the RSC procedure developed and applied as standard procedure in ANDRITZ HYDRO such a failure is excluded in an early design phase. Moreover, the RSC procedure is compatible with different commercial and open source codes and can be easily adapted to apply for
Efficient runner safety assessment during early design phase and root cause analysis
Liang, Q. W.; Lais, S.; Gentner, C.; Braun, O.
2012-11-01
Fatigue related problems in Francis turbines, especially high head Francis turbines, have been published several times in the last years. During operation the runner is exposed to various steady and unsteady hydraulic loads. Therefore the analysis of forced response of the runner structure requires a combined approach of fluid dynamics and structural dynamics. Due to the high complexity of the phenomena and due to the limitation of computer power, the numerical prediction was in the past too expensive and not feasible for the use as standard design tool. However, due to continuous improvement of the knowledge and the simulation tools such complex analysis has become part of the design procedure in ANDRITZ HYDRO. This article describes the application of most advanced analysis techniques in runner safety check (RSC), including steady state CFD analysis, transient CFD analysis considering rotor stator interaction (RSI), static FE analysis and modal analysis in water considering the added mass effect, in the early design phase. This procedure allows a very efficient interaction between the hydraulic designer and the mechanical designer during the design phase, such that a risk of failure can be detected and avoided in an early design stage.The RSC procedure can also be applied to a root cause analysis (RCA) both to find out the cause of failure and to quickly define a technical solution to meet the safety criteria. An efficient application to a RCA of cracks in a Francis runner is quoted in this article as an example. The results of the RCA are presented together with an efficient and inexpensive solution whose effectiveness could be proven again by applying the described RSC technics. It is shown that, with the RSC procedure developed and applied as standard procedure in ANDRITZ HYDRO such a failure is excluded in an early design phase. Moreover, the RSC procedure is compatible with different commercial and open source codes and can be easily adapted to apply for
A model of the environmental impacts of hydropower projects
International Nuclear Information System (INIS)
Kemppainen, T.; Haemaelaeinen, I.
1992-01-01
The aim was to create a model of the effects of hydropower modernization and extension projects in Finland. To illustrate the effects of hydropower projects a checklist in the form of matrice was constructed. In this matrice all issues that could be significant in future hydropower projects were collected. Stable physical environmental changes are the starting-point for this matrice. The temporary change of hydropower constructions have also been under consideration. These are mainly environmental changes during construction. In chapter two the effects of hydropower modernization and extension projects physical environmental changes were examined. In chapter three the matrice was applied to some example cases. The cases were chosen to represent future hydropower projects. In addition these example cases represent urban areas, rural areas and uninhabited areas. The example cases were the extension of Tainionkoski hydropower plant at Vuoksi river, the modernization of Aeetsae power plant at Kokemaeenjoki river, the modernization of Stadsfors power plant at Lapuanjoki river in the centre of Uusikaarlepyy town and the construction of Kaitfors power plant at Perhonjoki river. Conclusions from usability of the model can be drawn on the ground of the example cases. The purpose of the model is to produce a checklist of estimated environmental effects in hydropower project of various kinds. Examination of issues within the model depends on local circumstances. Endangered animal and plant species, for example, can be studied and estimated only if endangered animal and plant species exist in the area of hydropower plant. Furthermore, the direction and extent of environmental effects depend on the local circumstances. The model is mainly a checklist of environmental effects caused by hydropower plant projects
Hydropower in China at present and its further development
Energy Technology Data Exchange (ETDEWEB)
Chang, XiaoLin; Zhou, Wei [State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072 (China); Liu, Xinghong [School of Civil and Architectural Engineering, Wuhan University, Wuhan 430072 (China)
2010-11-15
At present, China's economic development faces energy challenge, and the appropriate solution of energy bottleneck is the key to healthy, rapid and sustainable development. China's gross amount of hydraulic resource ranks first in the world; however, because of low level of development, hydraulic resource has a broad development prospect. Now, China's hydropower development is in its peak period. By the end of 2004, the gross installed hydropower capacity of China broke through 100 million kW. From there, it has remained in the top slot worldwide. The vigorous development of hydropower is necessary because of the energy shortage and environmental pollution in China in order to attain sustainable development of China's economy. Abundant hydraulic resource, huge market demands, the strategy of western development and the favorable environment of economic development provide hydropower construction with unprecedented advantages and opportunities. Chins hydropower development aims at an installed hydropower capacity of up to 194 million kW by 2010, accounting for 23.1% of the gross installed power capacity and 35% of hydropower resource. Finally, we present the general condition of Three Gorges project as well as the new mode of hydropower development of Three Gorges Project Corporation, i.e., cascade development. (author)
Gis-based procedures for hydropower potential spotting
Energy Technology Data Exchange (ETDEWEB)
Larentis, Dante G.; Collischonn, Walter; Tucci, Carlos E.M. [Instituto de Pesquisas Hidraulicas da UFRGS, Av. Bento Goncalves, 9500, CEP 91501-970, Caixa Postal 15029, Porto Alegre, RS (Brazil); Olivera, Francisco (Texas A and M University, Zachry Department of Civil Engineering 3136 TAMU, College Station, TX 77843-3136, US)
2010-10-15
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. 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 large-scale survey of hydropower potential sites to be applied in the inception phase of hydroelectric development planning. The sequence of procedures to identify hydropower sites is based on remote sensing and regional streamflow data and was automated within a GIS-based computational program: Hydrospot. The program allows spotting more potential sites along the drainage network than it would be possible in a traditional survey study, providing different types of dam-powerhouse layouts and two types (operating modes) of projects: run-of-the-river and storage projects. Preliminary results from its applications in a hydropower-developed basin in Brazil have shown Hydrospot's limitations and potentialities in giving support to the mid-to-long-term planning of the electricity sector. (author)
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
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.
China’s rising hydropower demand challenges water sector
Liu, Junguo; Zhao, Dandan; Gerbens-Leenes, P. W.; Guan, Dabo
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 based on data from 875 representative reservoirs (209 with power plants). In 2010, the reservoir WF totaled 27.9 × 109 m3 (Gm3), or 22% of China’s total water consumption. Ignoring the reservoir WF seriously underestimates human water appropriation. The reservoir WF associated with industrial, domestic and agricultural WFs caused water scarcity in 6 of the 10 major Chinese river basins from 2 to 12 months annually. The hydropower WF was 6.6 Gm3 yr−1 or 3.6 m3 of water to produce a GJ (109 J) of electricity. Hydropower is a water intensive energy carrier. As a response to global climate change, the Chinese government has promoted a further increase in hydropower energy by 70% by 2020 compared to 2012. This energy policy imposes pressure on available freshwater resources and increases water scarcity. The water-energy nexus requires strategic and coordinated implementations of hydropower development among geographical regions, as well as trade-off analysis between rising energy demand and water use sustainability. PMID:26158871
Hydropower harvesting from a small scale reciprocating system
Energy Technology Data Exchange (ETDEWEB)
Malla, Ramesh B.; Shrestha, Binu; Bagtzoglou, Amvrossios; Drasdis, Jonathon [Department of Civil and Environmental Engineering, University of Connecticut, 261 Glenbrook Road, Storrs, CT 06269-2037 (United States); Johnson, Paul [eGen LLC, 1084 Shennecossett Road, Groton, CT 06340 (United States)
2011-05-15
Conventional hydropower systems that can take advantage of low head movement of water require substantial flow rates. However, these systems cannot harvest hydro energy from small sources of water with low head and low discharge, such as streams and creeks. The reciprocating hydropower system discussed in this paper can harvest power from such low flow discharge and low head sources. This paper presents a detailed proof-of-concept study of the hydropower model, including the underlining theoretical principles. Laboratory test results demonstrating the dependence of the lift force in the reciprocating small scale hydropower model as a function of flow velocity, size and rotational speed of the cylinder and comparison of the results with a previous study are also included. Two methods of power harvesting from the output displacement obtained from the hydropower system are discussed. The first employs electromagnetic induction principles and the other is based on a linear inertial generator using a conventional second order spring mass damper system. Finally, results from a finite element analysis of the hydropower system are presented and facilitate future design of the structural aspects of the housing for the reciprocating cylinder. (author)
The role of hydropower in environment ally sustainable energy development
International Nuclear Information System (INIS)
Gabriel, H.F.
2005-01-01
Hydropower has historically been the renewable energy leader, and from a technical-cost perspective, is very likely to remain the only viable renewable energy source for many countries. In recent years, hydropower has been much maligned, especially by NGOs, for not being a sustainable source of energy. Though hydropower is clearly a renewable source of energy, but the question arises whether it can also be sustainable. Hydropower can play an increasingly important role in enabling communities around the world to meet sustainability objectives. To become more accepted as a key contributor to sustainable energy systems, new and existing hydropower projects need to be built and operated in an environmentally, socially and economically sustainable manner. This paper highlights the sustain ability aspects of hydropower and discusses the criteria for selection of environmentally friendly hydropower project sites so that that hydropower can be developed in a sustainable manner and once again be considered favorably in the planning of generation mix for new energy development. Sustainability of hydropower projects involves treating both the social and environmental sustainability of the project at an early stage and including the interests of all stakeholders of the project. As a case study, the Ghazi- Barotha Hydropower Project (GBHP) in Pakistan has been selected, as it is the best example in managing the social issues and gaining public acceptance because of proper planning and addressing environmental and social issues at an early stage. (author)
An estimation of the Swiss hydropower rent
International Nuclear Information System (INIS)
Banfi, Silvia; Filippini, Massimo; Mueller, Adrian
2005-01-01
The electricity generation in Switzerland is mostly based on hydropower (∼58%) and nuclear power (∼38%). The exploitation of water in the hydropower sector can generate significant economic rent. One possibility to capture this rent is through royalties or fees. This system has been used in Switzerland since many decades. However, the actual water fee system is not flexible and does not take into consideration different production costs between the type and location of hydropower plants. Furthermore, storage plants can sell electricity to a higher price than run-of-river plants. A flexible system is needed in a liberalized electricity market, to take into account these different production situations and the fact that prices may vary considerably over time. The main goal of this paper is to calculate the potential economic rent that could be generated in the Swiss hydropower sector under a future liberalized market. Based on the results of the paper, it can be concluded that the introduction of a flexible fee system could improve the competitiveness of the hydropower sector and promote an energy system based on renewable energy sources
Kenyan and Ethiopian distance runners: what makes them so good?
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.
Conflicting hydropower development and aquatic ecosystem conservation in Bhutan
Wi, S.; Yang, Y. C. E.
2017-12-01
Hydropower is one of the clean energy sources that many Himalayan countries are eager to develop to solve their domestic energy deficit issue such as India, Nepal and Pakistan. Like other Himalayan countries, Bhutan also has a great potential for hydropower development. However, Bhutan is one of few countries that has a domestic energy surplus and export its hydropower generation to neighboring countries (mainly to India). Exporting hydropower is one of the major economic sources in Bhutan. However, constructions of dams and reservoirs for hydropower development inevitably involve habitat fragmentation, causing a conflict of interest with the pursuit of value in aquatic ecosystem conservation. The objectives of this study is to 1) develop a distributed hydrologic model with snow and glacier module to simulate the hydrologic regimes of seven major watersheds in Bhutan; 2) apply the hydrologic model to compute hydropower generation for all existing and potential dams; 3) evaluate cascade impacts of each individual dam on downstream regions by employing three hydro-ecological indicators: the River Connectivity Index (RCI), Dendritic Connectivity Index (DCI), total affected river stretch (ARS), and 4) analyze the tradeoffs between hydropower generation and river connectivity at the national scale by means of a multiple objective genetic algorithm. Modeling results of three Pareto Fronts between ecological indicators and hydropower generation accompany with future energy export targets from the government can inform dam selections that maximizing hydropower generation while minimizing the impact on the aquatic ecosystem (Figure 1a). The impacts of climate change on these Pareto front are also explored to identify robust dam selection under changing temperature and precipitation (Figure 1b).
Iliotibial band syndrome in runners: a systematic review.
van der Worp, Maarten P; van der Horst, Nick; de Wijer, Anton; Backx, Frank J G; Nijhuis-van der Sanden, Maria W G
2012-11-01
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 14%. In order to facilitate the evidence-based management of ITBS in runners, more needs to be learned about the aetiology, diagnosis and treatment of this injury. This article provides a systematic review of the literature on the aetiology, diagnosis and treatment of ITBS in runners. The Cochrane Library, MEDLINE, EMBASE, CINAHL, Web of Science, and reference lists were searched for relevant articles. Systematic reviews, clinical trials or observational studies involving adult runners (>18 years) that focused on the aetiology, diagnosis and/or treatment of ITBS were included and articles not written in English, French, German or Dutch were excluded. Two reviewers independently screened search results, assessed methodological quality and extracted data. The sum of all positive ratings divided by the maximum score was the percentage quality score (QS). Only studies with a QS higher than 60% were included in the analysis. The following data were extracted: study design; number and characteristics of participants; diagnostic criteria for ITBS; exposure/treatment characteristics; analyses/outcome variables of the study; and setting and theoretical perspective on ITBS. The studies of the aetiology of ITBS in runners provide limited or conflicting evidence and it is not clear whether hip abductor weakness has a major role in ITBS. The kinetics and kinematics of the hip, knee and/or ankle/foot appear to be considerably different in runners with ITBS to those without. The biomechanical studies involved small samples, and data seem to have been influenced by sex, height and weight of participants. Although most studies monitored the management of ITBS using clinical tests, these tests have not
CERN runners scale new heights
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...
The occurrence of injuries in recreational runners in Wroclaw
Directory of Open Access Journals (Sweden)
Kamil Michalik
2017-04-01
Full Text Available Introduction. Practicing sports activities e.g. running exposes individuals to physical injuries. Aim. Aim of the study was to determine the occurrence of injuries in runners training long running in Wrocław. The second aim was to investigate injury risk factors in runners. Materials and methods. In the study participated 255 subjects (157 man and 98 woman. The subjects were members in a running association WKB PIAST Wrocław, PRO-RUN Wrocław as well as non associated runners. In the study a diagnostic survey was used. Results. In this study 61% (n=156 of participants were injured, while 39% (n=100 trained without any injuries. Conclusions. The runners suffered from overloads in plantar fascia, cuff muscles and quadriceps muscles. The main injury factors were improper training loads and training surface.
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
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..
Private equity, public affair: Hydropower financing in the Mekong Basin
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
Metabolic factors limiting performance in marathon runners.
Rapoport, Benjamin I
2010-10-21
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.
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.
Hydropower's Biogenic Carbon Footprint.
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.
Hydropower's Biogenic Carbon Footprint
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. PMID:27626943
The water footprint of electricity from hydropower
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
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.
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.
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.
Hybrid Model Predictive Control as a LFC solution in Hydropower Plants
Directory of Open Access Journals (Sweden)
Donaisky Emerson
2015-01-01
Full Text Available For Electric Power System safety and stable operation, planning and analysis by using simulation environments are necessary. An important point for frequency stability analysis is, on one hand, an adequate representation of Load-Frequency Control (LFC loops and, on the other hand, the design of advanced control strategies to deal with the power system dynamic complexity. Therefore, in this paper we propose to represent the group turbine/penstock, found in hydropower plants, in a Piecewise Affine (PWA modelling structure. Based on such modelling, we also propose the use of a Hybrid Model Predictive algorithm to be use as a control law in LFC loops. Among the advantages of this PWA representation is the use of this model in the controller algorithm, thereby improving the Load-Frequency Control performance. Simulation results, on a 200 MW hydropower plant compares the performance of predictive control strategy presented with the classical PID control strategy in an isolated condition.
Foot-strike haemolysis in an ultramarathon runner.
Fazal, Abid A; Whittemore, Mary S; DeGeorge, Katharine C
2017-12-13
This case report describes mild anaemia and intravascular haemolysis in an otherwise healthy 41-year-old ultramarathon runner. In long-distance endurance athletes, trace gastrointestinal bleeding and plasma volume expansion are recognised sources of mild anaemia, often found incidentally. However, repetitive forceful foot striking can lead to blood cell lysis in the feet, resulting in a mild macrocytic anaemia and intravascular haemolysis, as was demonstrated in the patient described herein. Mild anaemia in runners, often called 'runner's pseudoanaemia', is typically clinically insignificant and does not require intervention. However, an unexplained anaemia can cause undue worry for otherwise healthy patients and lead to costly further testing, providing an argument against routine testing with complete blood counts in healthy, asymptomatic patients. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Haematological status in elite long-distance runners
DEFF Research Database (Denmark)
Suetta, C; Kanstrup, I L; Fogh-Andersen, N
1996-01-01
In 10 female and eight male Danish elite middle- and long-distance runners, haematological status, including blood volume, was examined. Haemoglobin, haematocrit and serum (s)-ferritin concentrations were all within the normal range. In both men and women, blood volume, plasma volume...... and erythrocyte volume were increased in relation to various reference values. However, the runners had a low body weight due to a reduced fat level, 9.5% (7.3-15.1%) fat for the women, 5.9% (5.0-8.8%) fat (median and ranges) for the men, measured by dual-energy X-ray absorptiometry (DEXA) scanning. When...... the runners' body weights were 'normalized' to a reference population (25% fat for women, 15% fat for men), only plasma volume remained increased in relation to body weight for the women, whereas all the volumes remained increased for the men. This confirms that endurance training induces a true increased...
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
Incidence of chronic knee lesions in long-distance runners based on training level: Findings at MRI
International Nuclear Information System (INIS)
Schueller-Weidekamm, Claudia; Schueller, Gerd; Uffmann, Martin; Bader, Till
2006-01-01
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
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.
Optimizing Wind And Hydropower Generation Within Realistic Reservoir Operating Policy
Magee, T. M.; Clement, M. A.; Zagona, E. A.
2012-12-01
Previous studies have evaluated the benefits of utilizing the flexibility of hydropower systems to balance the variability and uncertainty of wind generation. However, previous hydropower and wind coordination studies have simplified non-power constraints on reservoir systems. For example, some studies have only included hydropower constraints on minimum and maximum storage volumes and minimum and maximum plant discharges. The methodology presented here utilizes the pre-emptive linear goal programming optimization solver in RiverWare to model hydropower operations with a set of prioritized policy constraints and objectives based on realistic policies that govern the operation of actual hydropower systems, including licensing constraints, environmental constraints, water management and power objectives. This approach accounts for the fact that not all policy constraints are of equal importance. For example target environmental flow levels may not be satisfied if it would require violating license minimum or maximum storages (pool elevations), but environmental flow constraints will be satisfied before optimizing power generation. Additionally, this work not only models the economic value of energy from the combined hydropower and wind system, it also captures the economic value of ancillary services provided by the hydropower resources. It is recognized that the increased variability and uncertainty inherent with increased wind penetration levels requires an increase in ancillary services. In regions with liberalized markets for ancillary services, a significant portion of hydropower revenue can result from providing ancillary services. Thus, ancillary services should be accounted for when determining the total value of a hydropower system integrated with wind generation. This research shows that the end value of integrated hydropower and wind generation is dependent on a number of factors that can vary by location. Wind factors include wind penetration level
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
sheet has emphasized the risk of sudden changes in catchment supply. In this study, we present a thorough investigation of hydropower feasibility at the Paakitsoq basin, near Ilulissat in West Greenland. The catchment is completely dominated by the Greenland ice sheet which provides large quantities...... 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...
Bone stress in runners with tibial stress fracture.
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.
Developing a module for estimating climate warming effects on hydropower pricing in California
International Nuclear Information System (INIS)
Guégan, Marion; Uvo, Cintia B.; Madani, Kaveh
2012-01-01
Climate warming is expected to alter hydropower generation in California through affecting the annual stream-flow regimes and reducing snowpack. On the other hand, increased temperatures are expected to increase hydropower demand for cooling in warm periods while decreasing demand for heating in winter, subsequently altering the annual hydropower pricing patterns. The resulting variations in hydropower supply and pricing regimes necessitate changes in reservoir operations to minimize the revenue losses from climate warming. Previous studies in California have only explored the effects of hydrological changes on hydropower generation and revenues. This study builds a long-term hydropower pricing estimation tool, based on artificial neural network (ANN), to develop pricing scenarios under different climate warming scenarios. Results suggest higher average hydropower prices under climate warming scenarios than under historical climate. The developed tool is integrated with California's Energy-Based Hydropower Optimization Model (EBHOM) to facilitate simultaneous consideration of climate warming on hydropower supply, demand and pricing. EBHOM estimates an additional 5% drop in annual revenues under a dry warming scenario when climate change impacts on pricing are considered, with respect to when such effects are ignored, underlining the importance of considering changes in hydropower demand and pricing in future studies and policy making. - Highlights: ► Addressing the major gap in previous climate change and hydropower studies in California. ► Developing an ANN-based long-term hydropower price estimation tool. ► Estimating climate change effects on hydropower demand and pricing in California. ► Investigating the sensitivity of hydropower operations to future price changes. ► Underlining the importance of consideration of climate change impacts on electricity pricing.
Half-marathon and full-marathon runners' hydration practices and perceptions.
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 performance during runs greater than 1 hour (P 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. Greater attention should be paid to informing runners of valid techniques to monitor hydration status and developing an appropriate individualized hydration strategy.
Development of a pump-turbine runner based on multiobjective optimization
International Nuclear Information System (INIS)
Xuhe, W; Baoshan, Z; Lei, T; Jie, Z; Shuliang, C
2014-01-01
As a key component of reversible pump-turbine unit, pump-turbine runner rotates at pump or turbine direction according to the demand of power grid, so higher efficiencies under both operating modes have great importance for energy saving. In the present paper, a multiobjective optimization design strategy, which includes 3D inverse design method, CFD calculations, response surface method (RSM) and multiobjective genetic algorithm (MOGA), is introduced to develop a model pump-turbine runner for middle-high head pumped storage plant. Parameters that controlling blade shape, such as blade loading and blade lean angle at high pressure side are chosen as input parameters, while runner efficiencies under both pump and turbine modes are selected as objective functions. In order to validate the availability of the optimization design system, one runner configuration from Pareto front is manufactured for experimental research. Test results show that the highest unit efficiency is 91.0% under turbine mode and 90.8% under pump mode for the designed runner, of which prototype efficiencies are 93.88% and 93.27% respectively. Viscous CFD calculations for full passage model are also conducted, which aim at finding out the hydraulic improvement from internal flow analyses
Exaggerated gonadotropin response to luteinizing hormone-releasing hormone in amenorrheic runners.
Yahiro, J; Glass, A R; Fears, W B; Ferguson, E W; Vigersky, R A
1987-03-01
Most studies of exercise-induced amenorrhea have compared amenorrheic athletes (usually runners) with sedentary control subjects. Such comparisons will identify hormonal changes that develop as a result of exercise training but cannot determine which of these changes play a role in causing amenorrhea. To obviate this problem, we assessed reproductive hormone status in a group of five amenorrheic runners and compared them to a group of six eumenorrheic runners matched for body fatness, training intensity, and exercise performance. Compared to the eumenorrheic runners, the amenorrheic runners had lower serum estradiol concentrations, similar basal serum luteinizing hormone and follicle-stimulating hormone concentrations, and exaggerated responses of serum gonadotropins after administration of luteinizing hormone-releasing hormone (100 micrograms intravenous bolus). Serum prolactin levels, both basally and after thyrotropin-releasing hormone administration (500 micrograms intravenous bolus) or treadmill exercise, was similar in the two groups, as were serum thyroid function tests (including thyrotropin response to thyrotropin-releasing hormone). Changes in serum cortisol levels after short-term treadmill exercise were similar in both groups, and serum testosterone levels increased after exercise only in the eumenorrheic group. In neither group did such exercise change serum luteinizing hormone, follicle-stimulating hormone, or thyrotropin levels. We concluded that exercise-induced amenorrhea is not solely related to the development of increased prolactin output after exercise training. The exaggerated gonadotropin response to luteinizing hormone-releasing hormone seen in amenorrheic runners in comparison with matched eumenorrheic runners is consistent with a hypothalamic etiology for the menstrual dysfunction, analogous to that previously described in "stress-induced" or "psychogenic" amenorrhea.
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.
Dietary supplement usage and motivation in Brazilian road runners.
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.
Validations of CFD against detailed velocity and pressure measurements in water turbine runner flow
Nilsson, H.; Davidson, L.
2003-03-01
This work compares CFD results with experimental results of the flow in two different kinds of water turbine runners. The runners studied are the GAMM Francis runner and the Hölleforsen Kaplan runner. The GAMM Francis runner was used as a test case in the 1989 GAMM Workshop on 3D Computation of Incompressible Internal Flows where the geometry and detailed best efficiency measurements were made available. In addition to the best efficiency measurements, four off-design operating condition measurements are used for the comparisons in this work. The Hölleforsen Kaplan runner was used at the 1999 Turbine 99 and 2001 Turbine 99 - II workshops on draft tube flow, where detailed measurements made after the runner were used as inlet boundary conditions for the draft tube computations. The measurements are used here to validate computations of the flow in the runner.The computations are made in a single runner blade passage where the inlet boundary conditions are obtained from an extrapolation of detailed measurements (GAMM) or from separate guide vane computations (Hölleforsen). The steady flow in a rotating co-ordinate system is computed. The effects of turbulence are modelled by a low-Reynolds number k- turbulence model, which removes some of the assumptions of the commonly used wall function approach and brings the computations one step further.
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
-based local grid is supplied. In this case, the PV-battery system will operate as a PQ bus to inject the desired active and reactive powers to local grid, while the hydropower station will act as a slack bus which maintains its voltage amplitude and frequency. An integrated small-signal state-space model......, 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...
MAXIMIZING HYDROPOWER PRODUCTION FROM RESERVOIRS:THE CASE STUDY OF MARKABA
International Nuclear Information System (INIS)
Jaafar, H.
2014-01-01
Hydropower is a form of renewable energy that is clean and cheap. Under uncertain climatic conditions, maximization of hydropower production becomes a challenging task.Stochastic Dynamic programming (SDP) is a promising optimization algorithm that is usedfor complex non-linear reservoir operational policies and strategies.In this research, a combined simulation-SDPoptimization model isdeveloped andverified for maximizing large-scale hydropower production in a monthly time step. The model isdeveloped to generate optimal operational policies for the Qarawn reservoir in Lebanon and test these policies in real time conditions. The model isused to derive operational regimes for the Qarawn reservoirunder varying flows using transitional probability matrices. Simulating the derived rules and the generated operational policies proved effective in maximizingthe hydropower production from the Markaba power plant. The model could be successfully applied to other hydropower dams in the region. (author)
Assessment of small hydropower potential by software. Case study
Directory of Open Access Journals (Sweden)
Moldoveanu Alexandru
2017-01-01
Full Text Available The rivers hydropower potential is considered one of the oldest renewable energy source used in the electricity production process. A method to investigate the possibility to construct a micro hydropower system on a small river is presented. The analysis and the hydropower assessment were done by using Vapidro-Aste software. Results point out that micro-hydro units can be implemented in remote locations or hybrid renewable energy systems, while the environmental flow is guaranteed.
Modelling the feasibility of retrofitting hydropower to existing South ...
African Journals Online (AJOL)
sources (including nuclear energy) will be nearly 30% (Eskom,. 2011). South Africa ... Hydropower has the following advantages over other forms of .... well as negative environmental impacts. ... Potential environmental impacts of hydropower.
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
Kinematic classification of iliotibial band syndrome in runners.
Grau, S; Krauss, I; Maiwald, C; Axmann, D; Horstmann, T; Best, R
2011-04-01
Several inconsistent causative biomechanical factors are considered to be crucial in the occurrence of iliotibial band syndrome (ITBS). The focus of this study was on assessing differences in the kinematic characteristics between healthy runners [control group (CO)] and runners with ITBS in order to recommend treatment strategies to deal with this injury. Three-dimensional kinematics of barefoot running was used in the biomechanical setup. Both groups were matched with respect to gender, height and weight. After determining drop outs, the final population comprised 36 subjects (26 male and 10 female): 18 CO and 18 ITBS (13 male and five female, each). Kinematic evaluations indicate less hip adduction and frontal range of motion at the hip joint in runners with ITBS. Furthermore, maximum hip flexion velocity and maximum knee flexion velocity were lower in runners with ITBS. Lack of joint coordination, expressed as earlier hip flexion and a tendency toward earlier knee flexion, was found to be another discriminating variable in subjects with ITBS compared with CO subjects. We assume that an increase in range of motion at the hip joint, stretching of the hip abductors, as well as stretching the hamstrings, calf muscles and hip flexors will help treat ITBS. © 2009 John Wiley & Sons A/S.
Shin Splints 101: Explaining Shin Splints to Young Runners
Newlin, Dana; Smith, Darla S.
2011-01-01
Shin splints are a common but often confusing injury. Sources disagree on both the cause of the injury and the anatomical source of the pain. Some blame shin splints on foot pronation, footstrike pattern, or arch height. Regardless of what causes the condition, it affects many runners, beginning in some at a young age. Young runners often have…
Lower limb dynamics vary in shod runners who acutely transition to barefoot running.
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.
Barefoot-simulating footwear associated with metatarsal stress injury in 2 runners.
Giuliani, Jeffrey; Masini, Brendan; Alitz, Curtis; Owens, Brett D
2011-07-07
Stress-related changes and fractures in the foot are frequent in runners. However, the causative factors, including anatomic and kinematic variables, are not well defined. Footwear choice has also been implicated in contributing to injury patterns with changes in force transmission and gait analyses reported in the biomechanical literature. Despite the benefits of footwear, there has been increased interest among the running community in barefoot running with proposed benefits including a decreased rate of injury. We report 2 cases of metatarsal stress fracture in experienced runners whose only regimen change was the adoption of barefoot-simulating footwear. One was a 19-year-old runner who developed a second metatarsal stress reaction along the entire diaphysis. The second case was a 35-year-old ultra-marathon runner who developed a fracture in the second metatarsal diaphysis after 6 weeks of use of the same footwear. While both stress injuries healed without long-term effects, these injuries are alarming in that they occurred in experienced male runners without any other risk factors for stress injury to bone. The suspected cause for stress injury in these 2 patients is the change to barefoot-simulating footwear. Runners using these shoes should be cautioned on the potential need for gait alterations from a heel-strike to a midfoot-striking pattern, as well as cautioned on the symptoms of stress injury. Copyright 2011, SLACK Incorporated.
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.
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.
Game theory competition analysis of reservoir water supply and hydropower generation
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.
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.
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.
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, ...
Refurbishment of hydropower generation plants
International Nuclear Information System (INIS)
Kofler, W.
2001-01-01
This article presents the factors taken into consideration and the methods used for the management of refurbishment work in the hydropower installations of the TUWAG - a Tyrolean hydropower company in Austria. The technical and financial advantages to be gained from refurbishment are discussed and the requirements placed on the structuring of refurbishment projects are described. Various factors such as plant operation and maintenance, increased returns through better efficiency and cost reduction through lower wear and tear and reduced risk of failure are discussed. Annexes to the article cover monitoring and measurement techniques, the simulation of mechanical and hydraulic conditions, profitability calculations and turbine management
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
Addressing biogenic greenhouse gas emissions from hydropower in LCA.
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.
Short-term forecasting model for aggregated regional hydropower generation
International Nuclear Information System (INIS)
Monteiro, Claudio; Ramirez-Rosado, Ignacio J.; Fernandez-Jimenez, L. Alfredo
2014-01-01
Highlights: • Original short-term forecasting model for the hourly hydropower generation. • The use of NWP forecasts allows horizons of several days. • New variable to represent the capacity level for generating hydroelectric energy. • The proposed model significantly outperforms the persistence model. - Abstract: This paper presents an original short-term forecasting model of the hourly electric power production for aggregated regional hydropower generation. The inputs of the model are previously recorded values of the aggregated hourly production of hydropower plants and hourly water precipitation forecasts using Numerical Weather Prediction tools, as well as other hourly data (load demand and wind generation). This model is composed of three modules: the first one gives the prediction of the “monthly” hourly power production of the hydropower plants; the second module gives the prediction of hourly power deviation values, which are added to that obtained by the first module to achieve the final forecast of the hourly hydropower generation; the third module allows a periodic adjustment of the prediction of the first module to improve its BIAS error. The model has been applied successfully to the real-life case study of the short-term forecasting of the aggregated hydropower generation in Spain and Portugal (Iberian Peninsula Power System), achieving satisfactory results for the next-day forecasts. The model can be valuable for agents involved in electricity markets and useful for power system operations
Hydropower and biomass as renewable energy sources in Turkey
International Nuclear Information System (INIS)
Kaygusuz, K.
2001-01-01
When talking about renewable energy sources today, the most important and economical energy sources for Turkey are hydropower and biomass.The present study gives a review of production, consumption, and economics of hydropower and biomass as renewable energy sources in Turkey. Turkey has a total gross hydropower potential of 433 GW, but only 125 GW of the total hydroelectric potential of Turkey can be economically used. By the commissioning of new hydropower plants, which are under construction, 36% of the economically usable potential of the country could be tapped. On the other hand, biomass (wood and wastes) energy is the second most important renewable energy source for Turkey. However, the biomass energy sources of Turkey are limited. In 1998, the biomass share of the total energy consumption of the country is 10%. In this study, the potential of important biomass energy sources and animal solid wastes of the country were determined. The effects of hydropower and biomass usage on the environment were also discussed. Considering total cereal products and fatty seed plants, approximately 50-60 million tons per year of biomass and 8-10 million tons of solid matter animal waste are produced, and 70% of total biomass is seen as being usable for energy. Some useful suggestions and recommendations are also presented. The present study shows that there is an important potential for hydropower and biomass energy sources in Turkey. (author)
Estimation of economic parameters of U.S. hydropower resources
Energy Technology Data Exchange (ETDEWEB)
Hall, Douglas G. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab. (INEEL); Hunt, Richard T. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab. (INEEL); Reeves, Kelly S. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab. (INEEL); Carroll, Greg R. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab. (INEEL)
2003-06-01
Tools for estimating the cost of developing and operating and maintaining hydropower resources in the form of regression curves were developed based on historical plant data. Development costs that were addressed included: licensing, construction, and five types of environmental mitigation. It was found that the data for each type of cost correlated well with plant capacity. A tool for estimating the annual and monthly electric generation of hydropower resources was also developed. Additional tools were developed to estimate the cost of upgrading a turbine or a generator. The development and operation and maintenance cost estimating tools, and the generation estimating tool were applied to 2,155 U.S. hydropower sites representing a total potential capacity of 43,036 MW. The sites included totally undeveloped sites, dams without a hydroelectric plant, and hydroelectric plants that could be expanded to achieve greater capacity. Site characteristics and estimated costs and generation for each site were assembled in a database in Excel format that is also included within the EERE Library under the title, “Estimation of Economic Parameters of U.S. Hydropower Resources - INL Hydropower Resource Economics Database.”
Reevaluation of Turkey's hydropower potential and electric energy demand
International Nuclear Information System (INIS)
Yueksek, Omer
2008-01-01
This paper deals with Turkey's hydropower potential and its long-term electric energy demand predictions. In the paper, at first, Turkey's energy sources are briefly reviewed. Then, hydropower potential is analyzed and it has been concluded that Turkey's annual economically feasible hydropower potential is about 188 TWh, nearly 47% greater than the previous estimation figures of 128 TWh. A review on previous prediction models for Turkey's long-term electric energy demand is presented. In order to predict the future demand, new increment ratio scenarios, which depend on both observed data and future predictions of population, energy consumption per capita and total energy consumption, are developed. The results of 11 prediction models are compared and analyzed. It is concluded that Turkey's annual electric energy demand predictions in 2010, 2015 and 2020 vary between 222 and 242 (average 233) TWh; 302 and 356 (average 334) TWh; and 440 and 514 (average 476) TWh, respectively. A discussion on the role of hydropower in meeting long-term demand is also included in the paper and it has been predicted that hydropower can meet 25-35% of Turkey's electric energy demand in 2020
Examining injury risk and pain perception in runners using minimalist footwear.
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.
International Nuclear Information System (INIS)
Wang, Bing; Liang, Xiao-Jie; Zhang, Hao; Wang, Lu; Wei, Yi-Ming
2014-01-01
This paper analyzes the long-term relationships between hydropower generation and climate factors (precipitation), hydropower generation capacity (installed capacity of hydropower station) to quantify the vulnerability of renewable energy production in China for the case of hydropower generation. Furthermore, this study applies Grey forecasting model to forecast precipitation in different provinces, and then sets up different scenarios for precipitation based on the IPCC Special Report on Emission Scenarios and results from PRECIS (Providing Regional Climate projections for Impacts Studies) model. The most important result found in this research is the increasing hydropower vulnerability of the poorest regions and the main hydropower generation provinces of China to climate change. Other main empirical results reveal that the impacts of climate change on the supply of hydropower generation in China will be noteworthy for the society. Different scenarios have different effects on hydropower generation, of which A2 scenario (pessimistic, high emission) has the largest. Meanwhile, the impacts of climate change on hydropower generation of every province are distinctly different, of which the Southwest part has the higher vulnerability than the average level while the central part lower. - Highlights: • The hydropower vulnerability will be enlarged with the rapid increase of hydropower capacity. • Modeling the vulnerability of hydropower in different scenarios and different provinces. • The increasing hydropower vulnerability of the poorest regions to climate change. • The increasing hydropower vulnerability of the main hydropower generation provinces. • Rainfall pattern caused by climate change would be the reason for the increasing vulnerability
Dynamic analysis of a pumped-storage hydropower plant with random power load
Zhang, Hao; Chen, Diyi; Xu, Beibei; Patelli, Edoardo; Tolo, Silvia
2018-02-01
This paper analyzes the dynamic response of a pumped-storage hydropower plant in generating mode. Considering the elastic water column effects in the penstock, a linearized reduced order dynamic model of the pumped-storage hydropower plant is used in this paper. As the power load is always random, a set of random generator electric power output is introduced to research the dynamic behaviors of the pumped-storage hydropower plant. Then, the influences of the PI gains on the dynamic characteristics of the pumped-storage hydropower plant with the random power load are analyzed. In addition, the effects of initial power load and PI parameters on the stability of the pumped-storage hydropower plant are studied in depth. All of the above results will provide theoretical guidance for the study and analysis of the pumped-storage hydropower plant.
Evaluation of the dynamic behavior of a Pelton runner based on strain gauge measurements
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.
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...... that within the study period, only 23% of the tagged eels reached the tidal limit, mainly due to difficulties in passing the hydropower dam. With such high loss-rates, the escapement goals set in the management plan cannot be achieved...
Foot strike patterns of recreational and sub-elite runners in a long-distance road race.
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.
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.
75 FR 67993 - Hydropower Resource Assessment at Existing Reclamation Facilities-Draft Report
2010-11-04
... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Hydropower Resource Assessment at Existing... comment the ``Hydropower Resource Assessment at Existing Reclamation Facilities'' (HRA) Draft Report. The HRA is an assessment of the economic and technical potential for hydropower development at existing...
75 FR 81643 - Hydropower Resource Assessment at Existing Reclamation Facilities-Draft Report
2010-12-28
... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Hydropower Resource Assessment at Existing... period for review of the Hydropower Resource Assessment at Existing Reclamation Facilities Draft Report... sustainable, affordable hydropower for our national electricity supplies. Reclamation has 476 dams and 8,116...
Physiological and training characteristics of recreational marathon runners
Gordon, Dan; Wightman, Sarah; Basevitch, Itay; Johnstone, James; Espejo-Sanchez, Carolina; Beckford, Chelsea; Boal, Mariette; Scruton, Adrian; Ferrandino, Mike; Merzbach, Viviane
2017-01-01
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...
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.
Bridging the Information Gap: Remote Sensing and Micro Hydropower Feasibility in Data-Scarce Regions
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
The influence of climate change on Tanzania's hydropower sustainability
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
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.
Ultra-obligatory running among ultramarathon runners.
Hoffman, Martin D; Krouse, Rhonna
2018-01-01
Participants in the Ultrarunners Longitudinal TRAcking (ULTRA) Study were asked to answer "yes" or "no" to the question "If you were to learn, with absolute certainty, that ultramarathon running is bad for your health, would you stop your ultramarathon training and participation?" Among the 1349 runners, 74.1% answered "no". Compared with those answering "yes", they were younger (p life meaning (p = 0.0002) scores on the Motivations of Marathoners Scales. Despite a high health orientation, most ultramarathon runners would not stop running if they learned it was bad for their health as it appears to serve their psychological and personal achievement motivations and their task orientation such that they must perceive enhanced benefits that are worth retaining at the risk of their health.
78 FR 55251 - Hydropower Regulatory Efficiency Act of 2013; Notice of Workshop
2013-09-10
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. AD13-9-000] Hydropower... hydropower development at non-powered dams and closed-loop pumped storage projects in compliance with section 6 of the Hydropower Regulatory Efficiency Act of 2013. Participants should be prepared to discuss...
Kibler, K. M.; Alipour, M.
2017-12-01
Diversion hydropower has been shown to significantly alter river flow regimes by dewatering diversion bypass reaches. Data scarcity is one of the foremost challenges to establishing environmental flow regimes below diversion hydropower dams, especially in regions of sparse hydro-meteorological observation. Herein, we test two prediction strategies for generating daily flows in rivers developed with diversion hydropower: a catchment similarity model, and a rainfall-runoff model selected by multi-objective optimization based on soft data. While both methods are designed for ungauged rivers embedded within large regions of sparse hydrologic observation, one is more complex and computationally-intensive. The objective of this study is to assess the benefit of using complex modeling tools in data-sparse landscapes to support design of environmental flow regimes. Models were tested in gauged catchments and then used to simulate a 28-year record of daily flows in 32 ungauged rivers. After perturbing flows with the hydropower diversion, we detect alteration using Indicators of Hydrologic Alteration (IHA) metrics and compare outcomes of the two modeling approaches. The catchment similarity model simulates low flows well (Nash-Sutcliff efficiency (NSE) = 0.91), but poorly represents moderate to high flows (overall NSE = 0.25). The multi-objective rainfall-runoff model performs well overall (NSE = 0.72). Both models agree that flow magnitudes and variability consistently decrease following diversion as temporally-dynamic flows are replaced by static minimal flows. Mean duration of events sustained below the pre-diversion Q75 and mean hydrograph rise and fall rates increase. While we see broad areas of agreement, significant effects and thresholds vary between models, particularly in the representation of moderate flows. Thus, use of simplified streamflow models may bias detected alterations or inadequately characterize pre-regulation flow regimes, providing inaccurate
Fuzzy rule-based model for hydropower reservoirs operation
Energy Technology Data Exchange (ETDEWEB)
Moeini, R.; Afshar, A.; Afshar, M.H. [School of Civil Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)
2011-02-15
Real-time hydropower reservoir operation is a continuous decision-making process of determining the water level of a reservoir or the volume of water released from it. The hydropower operation is usually based on operating policies and rules defined and decided upon in strategic planning. This paper presents a fuzzy rule-based model for the operation of hydropower reservoirs. The proposed fuzzy rule-based model presents a set of suitable operating rules for release from the reservoir based on ideal or target storage levels. The model operates on an 'if-then' principle, in which the 'if' is a vector of fuzzy premises and the 'then' is a vector of fuzzy consequences. In this paper, reservoir storage, inflow, and period are used as premises and the release as the consequence. The steps involved in the development of the model include, construction of membership functions for the inflow, storage and the release, formulation of fuzzy rules, implication, aggregation and defuzzification. The required knowledge bases for the formulation of the fuzzy rules is obtained form a stochastic dynamic programming (SDP) model with a steady state policy. The proposed model is applied to the hydropower operation of ''Dez'' reservoir in Iran and the results are presented and compared with those of the SDP model. The results indicate the ability of the method to solve hydropower reservoir operation problems. (author)
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.
Hydropower development in the Philippines
International Nuclear Information System (INIS)
Lopez, P.L.
1997-01-01
The present policy on energy development is geared towards harnessing renewable and indigenous energy resource which can offer clean, abundant and efficient power supply for the country. a review of the current generation mix of the power system, especially the Luzon grid will establish a high dependency in imported fuel - oil and coal to power our generating plants. Thus, the policy of reducing dependence on imported fuel will depend largely on the success of tapping the alternative renewable and indigenous sources. The sustainable development era of the 90's brought fresh interest on the performance and commercial viability of indigenous and/or renewable sources of energy such as wind, solar, geothermal, natural gas and water power or hydropower. Among these alternative renewable sources, water or hydropower is the most readily available, and will produce clean domestic source of electricity - no carbon dioxide, sulfur dioxide, nitrous oxide or any other air emissions. The potential is available in most parts of the country that are mountainous and have high rainfall. In terms of production, hydropower leads as the most developed and more proven in terms of commercial viability. It is also more reliable, efficient and less expensive than geothermal, biomass, wind and solar energy, as will be shown later. (author)
Metallurgical and fatigue assessments of welds in cast welded hydraulic turbine runners
International Nuclear Information System (INIS)
Trudel, A; Sabourin, M
2014-01-01
Decades of hydraulic turbine operation around the world have shown one undeniable fact; welded turbine runners can be prone to fatigue cracking, especially in the vicinity of welds. In this regard, three factors are essential to consider in runner fatigue assessments: (1) the runner's design, which can induce stress concentrations in the fillets, (2) the casting process, which inherently creates defects such as shrinkage cavities and (3) the welding process, which induces significant residual stresses as well as a heat affected zone in the cast pieces near the interface with the filler metal. This study focuses on the latter, the welding process, with emphasis on the influence of the heat affected zone on the runner's fatigue behavior. In a recently concluded study by a large research consortium in Montreal, the microstructure and fatigue crack propagation properties of a CA6NM runner weld heat affected zone were thoroughly investigated to find if this zone deteriorates the runner's resistance to fatigue cracking. The main results showed that this zone's intrinsic fatigue crack propagation resistance is only slightly lower than the unaffected base metal because of its somewhat finer martensitic microstructure leading to a less tortuous crack path. However, it was also confirmed that weld-induced residual stresses represent the dominant influencing factor regarding fatigue crack propagation, though post-weld heat treatments are usually very effective in reducing such residual stresses. This paper aims to further confirm, through a case study, that the weld-induced heat affected zone does not compromise the reliability of welded turbine runners when its fatigue crack propagation properties are considered in fatigue damage models
Increased Vertebral Bone Mineral in Response to Reduced Exercise in Amenorrheic Runners
Lindberg, Jill S.; Hunt, Marjorie M.; Wade, Charles E.; Powell, Malcolm R.; Ducey, Diane E.
1987-01-01
Seven female runners found to have exercise-induced amenorrhea and decreased bone mineral were reevaluated after 15 months. During the 15-month period, four runners took supplemental calcium and reduced their weekly running distance by 43%, resulting in an average 5% increase in body weight, increased estradiol levels and eumenorrhea. Bone mineral content increased from 1.003±0.097 to 1.070±0.089 grams per cm.2 Three runners continued to have amenorrhea, with no change in running distance or ...
Integrating Economic and Ecological Benchmarking for a Sustainable Development of Hydropower
Directory of Open Access Journals (Sweden)
Philipp Emanuel Hirsch
2016-08-01
Full Text Available Hydropower reservoirs play an increasingly important role for the global electricity supply. Reservoirs are anthropogenically-dominated ecosystems because hydropower operations induce artificial water level fluctuations (WLF that exceed natural fluctuations in frequency and amplitude. These WLF have detrimental ecological effects, which can be quantified as losses to ecosystem primary production due to lake bottoms that fall dry. To allow for a sustainable development of hydropower, these “ecological costs” of WLF need to be weighed against the “economic benefits” of hydropower that can balance and store intermittent renewable energy. We designed an economic hydropower operation model to derive WLF in large and small reservoirs for three different future energy market scenarios and quantified the according losses in ecosystem primary production in semi-natural outdoor experiments. Our results show that variations in market conditions affect WLF differently in small and large hydropower reservoirs and that increasing price volatility magnified WLF and reduced primary production. Our model allows an assessment of the trade-off between the objectives of preserving environmental resources and economic development, which lies at the core of emerging sustainability issues.
Serum creatine kinase elevations in ultramarathon runners at high altitude.
Magrini, Danielle; Khodaee, Morteza; San-Millán, Iñigo; Hew-Butler, Tamara; Provance, Aaron J
2017-05-01
Creatine kinase (CK) is a sensitive enzyme marker for muscle damage in athletes. Elevated CK levels have been reported in many endurance physical activities. The consequence and possible long-term sequela of the CK elevation in athletes is unknown. There is a paucity of literature stating actual numerical values of CK associated with competing in an ultramarathon with extreme environmental conditions. Our hypothesis was that the serum CK levels increase significantly as a result of running a 161 km ultramarathon at high altitude. This was a prospective observational study of participants of the Leadville 100 ultramarathon race in Leadville, Colorado at high altitude (2800-3840 m) in August 2014. We collected blood samples from sixty-four volunteer runners before and eighty-three runners immediately after the race. Out of 669 athletes who started the race, 352 successfully completed the race in less than the 30-hour cut-off time (52%). The majority of runners were male (84%). We were able to collect both pre- and post-race blood samples from 36 runners. Out of these 36 runners, the mean pre-race CK was increased from 126 ± 64 U/L to 14,569 ± 14,729 U/L (p athletes' age, BMI, or finishing time. Significant elevation of CK level occurs as a result of running ultramarathons. The majority of athletes with significantly elevated CK levels were asymptomatic and required no major medical attention.
Physiological characteristics of the best Eritrean runners-exceptional running economy.
Lucia, Alejandro; Esteve-Lanao, Jonathan; Oliván, Jesús; Gómez-Gallego, Félix; San Juan, Alejandro F; Santiago, Catalina; Pérez, Margarita; Chamorro-Viña, Carolina; Foster, Carl
2006-10-01
Despite their young age, limited training history, and lack of running tradition compared with other East African endurance athletes (e.g., Kenyans and Ethiopians), male endurance runners from Eritrea have recently attained important running successes. The purposes of our study were (i) to document the main physical and physiological characteristics of elite black Eritrean distance runners (n = 7; age: 22 +/- 3 years) and (ii) to compare them with those of their elite white Spanish counterparts. For this second purpose we selected a control group of elite Spanish runners (n = 9; 24 +/- 2 years), owing to the traditionally high success of Spanish athletes in long-distance running compared with other white runners, especially in cross-country competitions. The subjects' main anthropometric characteristics were determined, together with their maximum oxygen uptake (VO2 max) and VO2 (mL.kg(-1).min(-1)), blood lactate, and ammonia concentrations while running at 17, 19, or 21 km.h(-1). The body mass index (18.9 +/- 1.5 kg.m(-2)) and maximal calf circumference (30.9 +/- 1.5 cm) was lower in Eritreans than in Spaniards (20.5 +/- 1.7 kg.m(-2) and 33.9 +/- 2.0 cm, respectively) (p economy of Eritreans is associated, at least partly, with anthropometric variables. Comparison of their submaximal running cost with other published data suggests that superior running economy, rather than enhanced aerobic capacity, may be the common denominator in the success of black endurance runners of East African origin.
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.
Sports drink consumption and dental erosion among amateur runners.
Antunes, Leonardo S; Veiga, Lais; Nery, Victor S; Nery, Caio C; Antunes, Lívia A
2017-01-01
This cross-sectional study assessed the prevalence and potential risk factors for dental erosion in amateur athletes at running events. After a sample calculation, 108 runners from the state of Rio de Janeiro, Brazil, were selected and examined for dental wear by a single trained and calibrated evaluator (kappa = 1.00). To identify risk factors, the runners were interviewed by using a standardized, semi-structured questionnaire. The average (SD) age of the runners was 34.2 (11.45), and the prevalence of dental erosion was 19.4%. Gastroesophageal reflux, running frequency per week, and time expended during competition were associated with dental erosion (P dental erosion was not significant (P > 0.05). In conclusion, dental erosion was not associated with use of isotonic drinks. However, frequency of exercise per week and gastroesophageal reflux were risk factors for dental erosion.
Increased vertebral bone mineral in response to reduced exercise in amenorrheic runners.
Lindberg, J S; Powell, M R; Hunt, M M; Ducey, D E; Wade, C E
1987-01-01
Seven female runners found to have exercise-induced amenorrhea and decreased bone mineral were reevaluated after 15 months. During the 15-month period, four runners took supplemental calcium and reduced their weekly running distance by 43%, resulting in an average 5% increase in body weight, increased estradiol levels and eumenorrhea. Bone mineral content increased from 1.003+/-0.097 to 1.070+/-0.089 grams per cm.(2) Three runners continued to have amenorrhea, with no change in running distance or body weight. Estradiol levels remained abnormally low and there was no significant change in the bone mineral content, although all three took supplemental calcium. We found that early osteopenia associated with exercise-induced menstrual dysfunction improved when runners reduced their running distance, gained weight and became eumenorrheic.
Iron excess in recreational marathon runners.
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 (Pmarathon runners. 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 (Pperformance, 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.
Developing hydropower overseas
International Nuclear Information System (INIS)
Smith, W.B.
1991-01-01
This article examines how the National Hydropower Association (NHA) has found ways to support its members who desire to expand their business programs to foreign markets through participation in a wide range of government programs. The topics of the article include the market in developing countries, the certificate of review, products and services, and domestic and international competition
Influence of El Niño Southern Oscillation on global hydropower production
Ng, Jia Yi; Turner, Sean; Galelli, Stefano
2016-04-01
Hydropower contributes significantly to meeting the world's energy demand, accounting for at least 16% of total electrical output. Its role as a mature and cost competitive renewable energy source is expected to become increasingly important as the world transits to a low-carbon economy. A key component of hydropower production is runoff, which is highly dependent on precipitation and other climate variables. As such, it becomes critical to understand how the drivers of climate variability impact hydropower production. One globally-important driver is the El Niño Southern Oscillation (ENSO). While it is known that ENSO influences hydrological processes, the potential value of its associated teleconnection in design related tasks has yet to be explored at the global scale. Our work seeks to characterize the impact of ENSO on global hydropower production so as to quantify the potential for increased production brought about by incorporating climate information within reservoir operating models. We study over 1,500 hydropower reservoirs - representing more than half the world's hydropower capacity. A historical monthly reservoir inflow time series is assigned to each reservoir from a 0.5 degree gridded global runoff dataset. Reservoir operating rules are designed using stochastic dynamic programming, and storage dynamics are simulated to assess performance under the climate conditions of the 20th century. Results show that hydropower reservoirs in the United States, Brazil, Argentina, Australia, and Eastern China are strongly influenced by ENSO episodes. Statistically significant lag correlations between ENSO indicators and hydropower production demonstrate predictive skill with lead times up to several months. Our work highlights the potential for using these indicators to increase the contribution of existing hydropower plants to global energy supplies.
Hydropower systems planning in distribution networks based on GIS
Energy Technology Data Exchange (ETDEWEB)
Ramirez-Rosado, I.J.; Zorzano-Santamaria, P.; Fernandez-Jiminez, L.A.; Garcia-Garrido, E.; Zorzano-Alba, E.; Lara-Santillan, P.M.; Mendoza-Villena, M. [La Rioja Univ., La Rioja (Spain). Dept. of Electrical Engineering
2005-07-01
Planning models for hydraulic energy systems developed with a new computational geographic information system (GIS) tool were presented. The GIS tool was used to identify sections of rivers that are suitable for small-scale run-of-river hydropower generation in the La Rioja region of Spain. The tool was also used to evaluate economic data related to financing grants, technological costs, installation costs, and forecast demands for various consumption scenarios. Case studies of 2 hydropower systems were used to test the tool. The planning models were based on levelized electric costs (LEC) of run-of-river hydropower systems, and enabled the systems to be analyzed in isolation as well as when connected to an existing electricity network. Results of the modelling studies showed that the tool is capable of analyzing the LEC of potential hydropower systems in a range of different scenarios while maintaining the geographic characteristics and requirements of individual regions. 7 refs., 4 figs.
Hydropower in the Southeast: Balancing Lakeview and Production Optimization
Engstrom, J.
2017-12-01
Hydropower is the most important source of renewable electricity in Southeastern U.S. However, the region is repeatedly struck by droughts, and there are many conflicting interests in the limited water resource. This study takes a historical perspective and investigates how hydropower production patterns have changed over time, considering both natural drivers and human dimensions. Hydropower production is strongly tied to the natural variability of large-scale atmospheric drivers (teleconnections) as they affect the water availability in the whole river system and partly also the market demand. To balance the water resource between different interests is a complex task, and the conflicting interests vary by basin, sometimes over a relatively small geographic area. Here road networks adjacent to the hydropower reservoirs are used as an indicator of human development and recreational activities. Through a network analysis of the historical development of road networks surrounding the reservoir, the local and regional conflicting interests are identified and the influence on renewable electricity production quantified.
Surrogate runner model for draft tube losses computation within a wide range of operating points
International Nuclear Information System (INIS)
Susan-Resiga, R; Ciocan, T; Muntean, S; De Colombel, T; Leroy, P
2014-01-01
We introduce a quasi two-dimensional (Q2D) methodology for assessing the swirling flow exiting the runner of hydraulic turbines at arbitrary operating points, within a wide operating range. The Q2D model does not need actual runner computations, and as a result it represents a surrogate runner model for a-priori assessment of the swirling flow ingested by the draft tube. The axial, radial and circumferential velocity components are computed on a conical section located immediately downstream the runner blades trailing edge, then used as inlet conditions for regular draft tube computations. The main advantage of our model is that it allows the determination of the draft tube losses within the intended turbine operating range in the early design stages of a new or refurbished runner, thus providing a robust and systematic methodology to meet the optimal requirements for the flow at the runner outlet
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
libRoadRunner: a high performance SBML simulation and analysis library.
Somogyi, Endre T; Bouteiller, Jean-Marie; Glazier, James A; König, Matthias; Medley, J Kyle; Swat, Maciej H; Sauro, Herbert M
2015-10-15
This article presents libRoadRunner, an extensible, high-performance, cross-platform, open-source software library for the simulation and analysis of models expressed using Systems Biology Markup Language (SBML). SBML is the most widely used standard for representing dynamic networks, especially biochemical networks. libRoadRunner is fast enough to support large-scale problems such as tissue models, studies that require large numbers of repeated runs and interactive simulations. libRoadRunner is a self-contained library, able to run both as a component inside other tools via its C++ and C bindings, and interactively through its Python interface. Its Python Application Programming Interface (API) is similar to the APIs of MATLAB ( WWWMATHWORKSCOM: ) and SciPy ( HTTP//WWWSCIPYORG/: ), making it fast and easy to learn. libRoadRunner uses a custom Just-In-Time (JIT) compiler built on the widely used LLVM JIT compiler framework. It compiles SBML-specified models directly into native machine code for a variety of processors, making it appropriate for solving extremely large models or repeated runs. libRoadRunner is flexible, supporting the bulk of the SBML specification (except for delay and non-linear algebraic equations) including several SBML extensions (composition and distributions). It offers multiple deterministic and stochastic integrators, as well as tools for steady-state analysis, stability analysis and structural analysis of the stoichiometric matrix. libRoadRunner binary distributions are available for Mac OS X, Linux and Windows. The library is licensed under Apache License Version 2.0. libRoadRunner is also available for ARM-based computers such as the Raspberry Pi. http://www.libroadrunner.org provides online documentation, full build instructions, binaries and a git source repository. hsauro@u.washington.edu or somogyie@indiana.edu Supplementary data are available at Bioinformatics online. Published by Oxford University Press 2015. This work is written
Chow, Tong-Hsien; Chen, Yih-Shyuan; Wang, Jia-Chang
2018-01-01
Plantar pressure measurement is effective for assessing plantar loading and can be applied to evaluating foot performance. We sought to explore the characteristics of plantar pressures in elite sprinters and recreational runners during static standing and walking. Arch index (AI) values, regional plantar pressure distributions (PPDs), and footprint characteristics were examined in 80 elite sprinters and 90 recreational runners using an optical plantar pressure measurement system. Elite sprinters' pain profiles were examined to evaluate their most common pain areas. In recreational runners, AI values in males were in the normal range and in females were high arch type. The AI values were significantly lower in elite sprinters than in recreational runners. In elite sprinters, particularly males, the static PPD of both feet was higher at the medial metatarsal bone and the lateral heel and lower at the medial and lateral longitudinal arches. Elite male sprinters' PPD of both feet was mainly transferred to the medial metatarsal bone and decreased at the lateral longitudinal arch and the medial heel during the midstance phase of walking. The lateral knee joint and biceps femoris were the most common sites of musculoskeletal pain in elite sprinters. Elite sprinters' AI values could be classified as high arches, and their PPD tended to parallel the features of runners and high-arched runners. These findings correspond to the profile of patellofemoral pain syndrome (PFPS)-related plantar pressure. The pain profiles seemed to resonate with the symptoms of high-arched runners and PFPS. A possible link between high-arched runners and PFPS warrants further study.
Mei, Qichang; Fernandez, Justin; Fu, Weijie; Feng, Neng; Gu, Yaodong
2015-08-01
Running is one of the most accessible physical activities and running with and without footwear has attracted extensive attention in the past several years. In this study 18 habitually male unshod runners and 20 habitually male shod runners (all with dominant right feet) participated in a running test. A Vicon motion analysis system was used to capture the kinematics of each participant's lower limb. The in-shoe plantar pressure measurement system was employed to measure the pressure and force exerted on the pressure sensors of the insole. The function of a separate hallux in unshod runners is analyzed through the comparison of plantar pressure parameters. Owing to the different strike patterns in shod and unshod runners, peak dorsiflexion and plantarflexion angle were significantly different. Habitually shod runners exhibited a decreased foot strike angle (FSA) under unshod conditions; and the vertical average loading rate (VALR) of shod runners under unshod conditions was larger than that under shod conditions. This suggests that the foot strike pattern is more important than the shod or unshod running style and runners need to acquire the technique. It can be concluded that for habitually unshod runners the separate hallux takes part of the foot loading and reduces loading to the forefoot under shod conditions. The remaining toes of rearfoot strike (RFS) runners function similarly under unshod conditions. These morphological features of shod and unshod runners should be considered in footwear design to improve sport performance and reduce injury. Copyright © 2015 Elsevier B.V. All rights reserved.
An empirical analysis of the hydropower portfolio in Pakistan
International Nuclear Information System (INIS)
Siddiqi, Afreen; Wescoat, James L.; Humair, Salal; Afridi, Khurram
2012-01-01
The Indus Basin of Pakistan with 800 hydropower project sites and a feasible hydropower potential of 60 GW, 89% of which is undeveloped, is a complex system poised for large-scale changes in the future. Motivated by the need to understand future impacts of hydropower alternatives, this study conducted a multi-dimensional, empirical analysis of the full hydropower portfolio. The results show that the full portfolio spans multiple scales of capacity from mega (>1000 MW) to micro (<0.1 MW) projects with a skewed spatial distribution within the provinces, as well as among rivers and canals. Of the total feasible potential, 76% lies in two (out of six) administrative regions and 68% lies in two major rivers (out of more than 125 total channels). Once projects currently under implementation are commissioned, there would be a five-fold increase from a current installed capacity of 6720 MW to 36759 MW. It is recommended that the implementation and design decisions should carefully include spatial distribution and environmental considerations upfront. Furthermore, uncertainties in actual energy generation, and broader hydrological risks due to expected climate change effects should be included in the current planning of these systems that are to provide service over several decades into the future. - Highlights: ► Pakistan has a hydropower potential of 60 GW distributed across 800 projects. ► Under-development projects will realize 36.7 GW of this potential by 2030. ► Project locations are skewed towards some sub-basins and provinces. ► Project sizes are very diverse and have quite limited private sector ownership. ► Gaps in data prevent proper risk assessment for Pakistan's hydropower development.
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, ...
Hydropower Impacts on Electrical System Production Costs in the Southwest United States
Directory of Open Access Journals (Sweden)
Dominique M. Bain
2018-02-01
Full Text Available The Colorado River is an important natural resource for the Southwestern United States. Predicted climate change impacts include increased temperature, decreased rainfall and increased probability of drought in this region. Given the large amount of hydropower on the Colorado River and its importance to the bulk electricity system, this purpose of this study was to quantify the value hydropower in operating the electrical system, and examined changes in hydropower value and electricity costs under different possible future drought conditions and regional generation scenarios. The goal was to better understand how these scenarios affect operating costs of the bulk electrical system, as well as the value of the hydropower produced, and proposed a method for doing so. The calculated value of the hydroelectric power was nearly double the mean locational marginal price in the study area, about $73 to $75 for most scenarios, demonstrating a high value of the hydropower. In general, it was found that reduced water availability increased operating costs, and increased the value of the hydropower. A calculated value factor showed that when less hydroelectric power is available, the hydropower is more valuable. Furthermore, the value factor showed that the value of hydro increases with the addition of solar or the retirement of thermal generating resources.
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.
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
Bridging the gap between metallurgy and fatigue reliability of hydraulic turbine runners
International Nuclear Information System (INIS)
Thibault, D; Gagnon, M; Godin, S
2014-01-01
The failure of hydraulic turbine runners is a very rare event. Hence, in order to assess the reliability of these components, one cannot rely on statistical models based on the number of failures in a given population. However, as there is a limited number of degradation mechanisms involved, it is possible to use physically-based reliability models. Such models are more complicated but have the advantage of being able to account for physical parameters in the prediction of the evolution of runner degradation. They can therefore propose solutions to help improve reliability. With the use of such models, the effect of materials properties on runner reliability can easily be illustrated. This paper will present a brief review of the Kitagawa-Takahashi diagram that links the damage tolerance approach, based on fracture mechanics, to the stress or strain-life approaches. This diagram is at the centre of the reliability model used in this study. Using simplified response spectra obtained from on-site runner stress measurements, the paper will show how fatigue reliability is impacted by materials fatigue properties, namely fatigue crack propagation behaviour and fatigue limit obtained on S-N curves. It will also present a review of the most important microstructural features of 13%Cr- 4%Ni stainless steels used for runner manufacturing and will review how they influence fatigue properties in an effort to bridge the gap between metallurgy and turbine runners reliability
[Diseases and overuse injuries of the lower extremities in long distance runners].
Tschopp, M; Brunner, F
2017-06-01
Running is one of the most popular sports worldwide, with running events attracting hundreds of thousands of runners of all age groups. Running is an effective way to improve health but is also associated with a high risk of injuries. Up to 50% of regular runners report having more than one injury each year. Some injuries are caused by an accident but most are caused by overuse. The most frequent diagnoses are patellofemoral pain syndrome, tibial stress syndrome (shin splint), Achilles tendinopathy, iliotibial band friction syndrome (runner's knee), plantar fasciitis and stress fractures of the metatarsals and tibia. The knee is the most frequently injured joint in runners at all distances. Hamstring injuries are typically acute resulting in a sudden, sharp pain in the posterior thigh. Hip injuries are less common but it can be more difficult to make the correct diagnosis and treatment is more complex. Clinicians confronted by runners with shin pain must distinguish between stress fractures of the tibia, tibial stress syndrome (shin splints) and chronic exertional compartment syndrome. Foot and ankle injuries are the most common injuries reported by long distance and marathon runners. Excess body weight and the number of kilometers run per week are high risk factors for injuries. The roles of other factors, such as shoes, stretching and biomechanics are less clear. A detailed anamnesis and physical examination are important for the correct diagnosis or the necessity for further diagnostic imaging and subsequent therapy.
Foot strike patterns and collision forces in habitually barefoot versus shod runners.
Lieberman, Daniel E; Venkadesan, Madhusudhan; Werbel, William A; Daoud, Adam I; D'Andrea, Susan; Davis, Irene S; Mang'eni, Robert Ojiambo; Pitsiladis, Yannis
2010-01-28
Humans have engaged in endurance running for millions of years, but the modern running shoe was not invented until the 1970s. For most of human evolutionary history, runners were either barefoot or wore minimal footwear such as sandals or moccasins with smaller heels and little cushioning relative to modern running shoes. We wondered how runners coped with the impact caused by the foot colliding with the ground before the invention of the modern shoe. Here we show that habitually barefoot endurance runners often land on the fore-foot (fore-foot strike) before bringing down the heel, but they sometimes land with a flat foot (mid-foot strike) or, less often, on the heel (rear-foot strike). In contrast, habitually shod runners mostly rear-foot strike, facilitated by the elevated and cushioned heel of the modern running shoe. Kinematic and kinetic analyses show that even on hard surfaces, barefoot runners who fore-foot strike generate smaller collision forces than shod rear-foot strikers. This difference results primarily from a more plantarflexed foot at landing and more ankle compliance during impact, decreasing the effective mass of the body that collides with the ground. Fore-foot- and mid-foot-strike gaits were probably more common when humans ran barefoot or in minimal shoes, and may protect the feet and lower limbs from some of the impact-related injuries now experienced by a high percentage of runners.
Melanoma markers in marathon runners: increase with sun exposure and physical strain.
Richtig, Erika; Ambros-Rudolph, Christina M; Trapp, Michael; Lackner, Helmut K; Hofmann-Wellenhof, Rainer; Kerl, Helmut; Schwaberger, Guenther
2008-01-01
Marathon runners seem to have an increased melanoma risk. To identify potential melanoma markers. 150 marathon runners volunteered to take part in the skin cancer screening campaign. After the runners completed a questionnaire about melanoma risk factors, types of sportswear and training programs, they received a total skin examination. The number of lentigines and nevi on the left shoulder and the left buttock were counted in each participant using templates in standardized positions. The potential association of training sportswear and training parameters with the number of lentigines and nevi on the left shoulder was evaluated. The mean number of lentigines on the left shoulder was 19.6 +/- 18.2 (SD), whereas no lentigines were found on the left buttock (p = 0.000). The number of nevi also differed significantly between the 2 localizations with higher numbers on the left shoulder (p = 0.000). While lifetime sunburn history and type of sportswear correlated with the number of lentigines, training parameters had an impact on the number of nevi. Independent of their mean weekly running time, runners with higher heart rates while training, higher training velocities and higher physical strain indexes showed more nevi on the shoulder than the other runners (p = 0.029, 0.046, 0.038, respectively). Sun exposure and high physical strain lead to an increase in melanoma markers such as lentigines and nevi in marathon runners. Copyright 2008 S. Karger AG, Basel.
2012-08-24
...: Alternatives Process in Hydropower Licensing AGENCY: Office of the Secretary, Office of Environmental Policy... approval for the collection of information for Alternatives Process in Hydropower Licensing. This... comments should reference Alternatives Process in Hydropower Licensing. FOR FURTHER INFORMATION CONTACT: To...
Renewable energy in the Baltic countries: the case of hydropower
International Nuclear Information System (INIS)
Punys, P.; Dumbrauskas, A.; Rimkus, Z.; Streimikiene, D.
2006-01-01
This paper analyses the use of renewable energy sources (RES) dedicated mainly for electricity generation in the Baltic countries (Estonia, Latvia and Lithuania). Hydropower sector including both large (medium) and small power plants is particularly considered. The region has very limited energy resources of its own and is heavily dependent on the import of the primary energy sources (in some way except Estonia). The main objective of energy policy of the Baltic countries is to reduce such a total dependence by favouring the use of RES. A brief description of energy sector is given, focusing on electricity generation. RES potential currently in use and to be exploited in the future, buy- back rates of the key sources are presented. The countries' target broken down according to the individual RES to meet the EU 'green' electricity directive (2001/77/CE) are presented. Small and large hydropower potential is analyzed, a general overview of hydro-plants in operation and planned schemes is provided. A particular attention is devoted to environmental and social aspects of hydropower development. The requirements of the protected areas in relation to dam construction are analyzed, an estimation of resistance to small hydropower development is shown. The environmental legislation including forbidden rivers for damming actually in force in the Baltic countries is considered; hydropower image perceptible by general public, NGOs and official environmental bodies are discussed. The causes and legal basis of the promulgation of the list of forbidden rivers are revealed. A conclusion is drawn that the contradiction between two EU legal frameworks - environmental protection and promotion of renewables, in the case of hydropower, exists. The evaluation of the quantitative impact of the forbidden rivers on small hydropower resources in Lithuania proves. the environmental legislation is one of the strictest in the European countries. (authors)
The potential micro-hydropower projects in Nakhon Ratchasima province, Thailand
International Nuclear Information System (INIS)
Kosa, Preeyaphorn; Chinkulkijniwat, Avirut; Horpibulsuk, Suksun; Kulworawanichpong, Thanatchai; Srivoramas, Rerkchai; Teaumroong, Neung
2011-01-01
At present, fossil fuel energy is commonly used in developing countries, including Thailand. The tendency to use fossil fuel energy is continuously increasing, and the price of fossil fuels is rising. Thus, renewable energy is of interest. Hydropower is one of the oldest renewable energy forms known and one of the best solutions for providing electricity to rural communities. The present paper aims to determine the potential micro-hydropower sites that could provide more than 50 kW but not over 10 MW in Nakhon Ratchasima Province, Thailand. Both reservoir and run-of-the-river schemes are considered for the assessment of potential micro-hydropower sites. For the reservoir scheme, the discharge in the reservoir is employed for generating micro-hydropower electricity. This installation can be carried out without major modifications to the dam. The run-of-the-river scheme diverts water flow from the river mainstream to the intake via a pressure pipe or an open canal, which is then conveyed to the turbine via a penstock to generate electricity. The results showed that there are 6 suitable projects for the reservoir scheme and 11 suitable projects for the run-of-the-river. The maximum power load was 6000 kW and 320 kW for the reservoir and the run-of-the-river schemes, respectively. Hydropower from the run-of-the-river scheme is more suitable than hydropower from the reservoir scheme because of the many mountains in this province. The designed head for the run-of-the-river scheme is thus generally higher than that for the reservoir scheme. Because stream flow during the dry season is very low, electricity can only be produced in the wet season. This research is a pilot study to determine the potential sites of micro-hydropower projects. (author)
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
Hot Runner Mold Design of Fan Diverter Parts
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.
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.
Foot strike and injury rates in endurance runners: a retrospective study.
Daoud, Adam I; Geissler, Gary J; Wang, Frank; Saretsky, Jason; Daoud, Yahya A; Lieberman, Daniel E
2012-07-01
This retrospective study tests if runners who habitually forefoot strike have different rates of injury than runners who habitually rearfoot strike. We measured the strike characteristics of middle- and long-distance runners from a collegiate cross-country team and quantified their history of injury, including the incidence and rate of specific injuries, the severity of each injury, and the rate of mild, moderate, and severe injuries per mile run. Of the 52 runners studied, 36 (69%) primarily used a rearfoot strike and 16 (31%) primarily used a forefoot strike. Approximately 74% of runners experienced a moderate or severe injury each year, but those who habitually rearfoot strike had approximately twice the rate of repetitive stress injuries than individuals who habitually forefoot strike. Traumatic injury rates were not significantly different between the two groups. A generalized linear model showed that strike type, sex, race distance, and average miles per week each correlate significantly (P strike have significantly higher rates of repetitive stress injury than those who mostly forefoot strike. This study does not test the causal bases for this general difference. One hypothesis, which requires further research, is that the absence of a marked impact peak in the ground reaction force during a forefoot strike compared with a rearfoot strike may contribute to lower rates of injuries in habitual forefoot strikers.
2012-05-22
...: Alternatives Process in Hydropower Licensing AGENCY: Office of the Secretary, Office of Environmental Policy... the Alternatives Process in Hydropower Licensing, OMB Control Number 1094-0001. FOR FURTHER... more of the Departments develop for inclusion in a hydropower license issued by the Federal Energy...
Modelling the feasibility of retrofitting hydropower to existing South ...
African Journals Online (AJOL)
An investigation was carried out with the primary objective of ascertaining whether it is possible to develop a model for determining the feasibility of retrofitting hydropower to existing dams in South Africa. The need for such a model is primarily due to the growing importance of small-scale hydropower projects resulting from ...
2010-10-26
... Hydropower, LLC; Notice of Application Ready for Environmental Analysis and Soliciting Comments...: Inglis Hydropower, LLC. e. Name of Project: Inglis Hydropower Project. f. Location: The project would be... ready for environmental analysis at this time. l. The proposed 2.0-megawatt Inglis Hydropower Project...
Running Economy: Neuromuscular and Joint Stiffness Contributions in Trained Runners.
Tam, Nicholas; Tucker, Ross; Santos-Concejero, Jordan; Prins, Danielle; Lamberts, Robert P
2018-05-29
It is debated whether running biomechanics make good predictors of running economy, with little known information about the neuromuscular and joint stiffness contributions to economical running gait. The aim of this study was to understand the relationship between certain neuromuscular and spatiotemporal biomechanical factors associated with running economy. Thirty trained runners performed a 6-minute constant-speed running set at 3.3 m∙s -1 , where oxygen consumption was assessed. Overground running trials were also performed at 3.3 m∙s -1 to assess kinematics, kinetics and muscle activity. Spatiotemporal gait variables, joint stiffness, pre-activation and stance phase muscle activity (gluteus medius; rectus femoris (RF); biceps femoris(BF); peroneus longus (PL); tibialis anterior (TA); gastrocnemius lateralis and medius (LG and MG) were variables of specific interest and thus determined. Additionally, pre-activation and ground contact of agonist:antagonist co-activation were calculated. More economical runners presented with short ground contact times (r=0.639, p<0.001) and greater strides frequencies (r=-0.630, p<0.001). Lower ankle and greater knee stiffness were associated with lower oxygen consumption (r=0.527, p=0.007 & r=0.384, p=0.043, respectively). Only LG:TA co-activation during stance were associated with lower oxygen cost of transport (r=0.672, p<0.0001). Greater muscle pre-activation and bi-articular muscle activity during stance were associated with more economical runners. Consequently, trained runners who exhibit greater neuromuscular activation prior to and during ground contact, in turn optimise spatiotemporal variables and joint stiffness, will be the most economical runners.
Directory of Open Access Journals (Sweden)
Daqing Zhou
2018-04-01
Full Text Available The transient characteristic of the power-off process is investigated due to its close relation to hydraulic facilities’ safety in a pumped storage hydropower (PSH. In this paper, power-off transient characteristics of a PSH station in pump mode was studied using a three-dimensional (3D unsteady numerical method based on a single-phase and volume of fluid (SP-VOF coupled model. The computational domain covered the entire flow system, including reservoirs, diversion tunnel, surge tank, pump-turbine unit, and tailrace tunnel. The fast changing flow fields and dynamic characteristic parameters, such as unit flow rate, runner rotate speed, pumping lift, and static pressure at measuring points were simulated, and agreed well with experimental results. During the power-off transient process, the PSH station underwent pump mode, braking mode, and turbine mode, with the dynamic characteristics and inner flow configurations changing significantly. Intense pressure fluctuation occurred in the region between the runner and guide vanes, and its frequency and amplitude were closely related to the runner’s rotation speed and pressure gradient, respectively. While the reversed flow rate of the PSH unit reached maximum, some parameters, such as static pressure, torque, and pumping lift would suddenly jump significantly, due to the water hammer effect. The moment these marked jumps occurred was commonly considered as the most dangerous moment during the power-off transient process, due to the blade passages being clogged by vortexes, and chaos pressure distribution on the blade surfaces. The results of this study confirm that 3D SP-VOF hybrid simulation is an effective method to reveal the hydraulic mechanism of the PSH transient process.
Damages and methods for reparation; Hydropower structures; Skador och reparationsmetoder
Energy Technology Data Exchange (ETDEWEB)
Sandstroem, Tomas
2008-10-15
As the focus of the Swedish Hydropower Industry shifted from the developing phase of the 20th century to the present phase of managing and maintenance of the hydropower plants and the adherent structures knowledge regarding issues concerning repair work and degradation processes of concrete has become truly important. Hydropower structures are submitted to live loads (for example caused by ice, water, snow and wind) and physical attacks such as Freeze/thaw, leaching and erosion (abrasion and cavitation). Hydropower structures are also submitted to chemical and electro chemical attacks like ASR and corrosion of the reinforcement bars. All of the mentioned processes have a negative affect on concrete structures service life. As it is today the Hydropower Industry possesses a rather high degree of knowledge concerning principal repair and strengthening techniques like shotcreting and grouting. The purpose of this report is (1) to point out the Swedish Hydropower Industry's need for extensive knowledge regarding overlays and toppings and (2) the potential advantages of overlays and toppings as repair techniques with respect to hydropower environments and the corresponding degradation processes acting on those structures. The performance of repairing a concrete structure using overlays or toppings is principally executed by the removal (totally or partially) of the damaged concrete surface, afterwards a new concrete overlay or topping is applied. The overlay must be able to withstand the live loads and the physical, chemical and electro-chemical attacks that are acting on the structure. The overlay is also required to co-operate with, and protect, the host material for a very long time. This report deals with the most common types of physical and chemical processes that are acting in Hydropower environments and the damages that they are causing concrete structures. Some of the common principal repair techniques that can be used when repairing the damaged concrete
Water-quality impact assessment for hydropower
International Nuclear Information System (INIS)
Daniil, E.I.; Gulliver, J.; Thene, J.R.
1991-01-01
A methodology to assess the impact of a hydropower facility on downstream water quality is described. Negative impacts can result from the substitution of discharges aerated over a spillway with minimally aerated turbine discharges that are often withdrawn from lower reservoir levels, where dissolved oxygen (DO) is typically low. Three case studies illustrate the proposed method and problems that can be encountered. Historic data are used to establish the probability of low-dissolved-oxygen occurrences. Synoptic surveys, combined with downstream monitoring, give an overall picture of the water-quality dynamics in the river and the reservoir. Spillway aeration is determined through measurements and adjusted for temperature. Theoretical computations of selective withdrawal are sensitive to boundary conditions, such as the location of the outlet-relative to the reservoir bottom, but withdrawal from the different layers is estimated from measured upstream and downstream temperatures and dissolved-oxygen profiles. Based on field measurements, the downstream water quality under hydropower operation is predicted. Improving selective withdrawal characteristics or diverting part of the flow over the spillway provided cost-effective mitigation solutions for small hydropower facilities (less than 15 MW) because of the low capital investment required
The Runners and Injury Longitudinal Study: Injury Recovery Supplement (TRAILS_IR)
2013-08-01
2) develop statistical models that integrate biomechanical, behavioral, and psychological risk factors for injury, (3) determine the length of...Running Mechanics and Flexibility Between Runners in Minimalist and Traditional Footwear ”......14...annual meeting entitled “Differences in Running Mechanics and Flexibility between Runners in Minimalist and Traditional Footwear ”. The following
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
Altered neuroendocrine regulation of gonadotropin secretion in women distance runners.
Veldhuis, J D; Evans, W S; Demers, L M; Thorner, M O; Wakat, D; Rogol, A D
1985-09-01
We tested the hypothesis that the neuroendocrine control of gonadotropin secretion is altered in certain women distance runners with secondary amenorrhea. To this end, we quantitated the frequency and amplitude of spontaneous pulsatile LH secretion during a 24-h interval in nine such women. The ability of the pituitary gland to release LH normally was assessed by administration of graded bolus doses of GnRH during the subsequent 8 h. Compared to normally menstruating women, six of nine amenorrheic distance runners had a distinct reduction in spontaneous LH pulse frequency, with one, three, six, five, four, or two pulses per 24 h (normal, 8-15 pulses/24 h). This reduction in LH pulse frequency occurred without any significant alterations in plasma concentrations of estradiol and free testosterone or 24-h integrated serum concentrations of LH, FSH, or PRL. Moreover, in long-distance runners, the capacity of the pituitary gland to release LH was normal or accentuated in response to exogenous pulses of GnRH. In the six women athletes with diminished spontaneous LH pulsatility, acute ovarian responsiveness also was normal, since serum estradiol concentrations increased normally in response to the GnRH-induced LH pulses. Although long-distance runners had significantly lower estimated percent body fat compared to control women, specific changes in pulsatile gonadotropin release did not correlate with degree of body leanness. In summary, certain long-distance runners with secondary amenorrhea or severe oligomenorrhea have unambiguously decreased spontaneous LH pulse frequency with intact pituitary responsiveness to GnRH. This neuroendocrine disturbance may be relevant to exercise-associated amenorrhea, since pulsatile LH release is a prerequisite for cyclic ovarian function. We speculate that such alterations in pulsatile LH release in exercising women reflect an adaptive response of the hypothalamic pulse generator controlling the intermittent GnRH signal to the
Hydropower is not plain sailing all the way
International Nuclear Information System (INIS)
De Vries, E.
1991-01-01
A report is given of the conference Hidroenergia 1991, which was held in Nice, France, from 12 to 15 June. The author highlights the subjects on the problems of implementing hydro-power, and the environmental effects of the use of hydro-power. Special attention is paid to the activities of the European Community to limit the constraints, which form hindrances to the development of hydroelectric power. 2 ills., 3 refs
Echocardiographic left ventricular masses in distance runners and weight lifters
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.
Normative values of eccentric hip abduction strength in novice runners
DEFF Research Database (Denmark)
Ramskov, D; Pedersen, M B; Kastrup, K
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...... was found, p values were identified using a regression equation adjusting for age and gender. Based on this, the equation to calculate normative values for relative eccentric hip abduction strength became: (1.600 + (age * -0.005) + (gender (1 = male / 0 = female) * 0.215) ± 1 or 2 * 0......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...
Maximal respiratory pressures and pulmonary function in male runners.
Cordain, L; Glisan, B J; Latin, R W; Tucker, A; Stager, J M
1987-01-01
To determine the effects of long term exercise on respiratory muscle strength, maximal inspiratory (Pl max) and expiratory (PE max) pressures, pulmonary volumes and capacities and anthropometric parameters were measured in a group of 101 male runners aged 16 to 58 years. The runners exhibited significantly (p less than 0.05) lower PE max (202 +/- 41 cm H2O and significantly greater residual lung volumes (RV) (2.08 +/- 0.49 L) than predicted values for normal subjects of similar height and age...
Development activities, challenges and prospects for the hydropower sector in Austria
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.
78 FR 58535 - Hydropower Regulatory Efficiency Act of 2013; Supplemental Notice of Workshop
2013-09-24
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. AD13-9-000] Hydropower... license for hydropower development at non-powered dams and closed-loop pumped storage projects in compliance with section 6 of the Hydropower Regulatory Efficiency Act of 2013. The workshop will be held in...
The Grossmatt hydro-power station
International Nuclear Information System (INIS)
Hintermann, M.
2006-01-01
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
Operating multireservoir hydropower systems for downstream water quality
International Nuclear Information System (INIS)
Hayes, D.F.
1990-01-01
Hydropower reservoir operations often impact tailwater quality and water quality in the stream or river below the impoundment for many miles. Determining optimal operating strategies for a system of hydropower reservoirs involves solving a highly dimensional nonlinear, nonconvex optimization problem. This research adds the additional complexities of downstream water quality considerations within the optimization formulation to determine operating strategies for a system of hydropower reservoirs operating in series (tandem) or parallel. The formulation was used to determine operating strategies for six reservoirs of the upper Cumberland river basin in Tennessee and Kentucky. Significant dissolved oxygen (DO) violations occur just upstream of Nashville, Tennessee below Old Hickory dam during the months of August and September. Daily reservoir releases were determined for the period of June through September which would produce the maximum hydropower revenue while meeting downstream water quality objectives. Optimal releases for three operational strategies were compared to historical operations for the years 1985, 1986, and 1988. These strategies included: spilling as necessary to meet water quality criteria, near normal operation (minimal spills), and drawdown of reservoirs as necessary to meet criteria without spills. Optimization results showed an 8% to 15% hydropower loss may be necessary to meet water quality criteria through spills and a 2% to 9% improvement in DO below Old Hickory may be possible without significant spills. Results also showed that substantial increases in initial headwater elevations would be necessary to meet daily DO criteria and avoid spills. The optimal control theory algorithm used to solve the problem proved to be an efficient and robust solver of this large optimization problem
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.
CERN runners on the podium for the Escalade race
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 ...
Greenhouse gas emissions of hydropower in the Mekong River Basin
Räsänen, Timo A.; Varis, Olli; Scherer, Laura; Kummu, Matti
2018-03-01
The Mekong River Basin in Southeast Asia is undergoing extensive hydropower development, but the magnitudes of related greenhouse gas emissions (GHG) are not well known. We provide the first screening of GHG emissions of 141 existing and planned reservoirs in the basin, with a focus on atmospheric gross emissions through the reservoir water surface. The emissions were estimated using statistical models that are based on global emission measurements. The hydropower reservoirs (119) were found to have an emission range of 0.2-1994 kg CO2e MWh-1 over a 100 year lifetime with a median of 26 kg CO2e MWh-1. Hydropower reservoirs facilitating irrigation (22) had generally higher emissions reaching over 22 000 kg CO2e MWh-1. The emission fluxes for all reservoirs (141) had a range of 26-1813 000 t CO2e yr-1 over a 100 year lifetime with a median of 28 000 t CO2e yr-1. Altogether, 82% of hydropower reservoirs (119) and 45% of reservoirs also facilitating irrigation (22) have emissions comparable to other renewable energy sources (equalling even the emission from fossil fuel power plants (>380 kg CO2e MWh-1). These results are tentative and they suggest that hydropower in the Mekong Region cannot be considered categorically as low-emission energy. Instead, the GHG emissions of hydropower should be carefully considered case-by-case together with the other impacts on the natural and social environment.
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...
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.
Greenhouse gas emissions from hydropower. The state of research in 1996
International Nuclear Information System (INIS)
Gagnon, L.; Vate, J.F. van de
1997-01-01
This paper reports on the findings of a recent IAEA expert meeting on the assessment of greenhouse gas (GHG) emissions from the full 'lifecycle' of hydropower. It discusses the different categories of hydropower plants in view of the two main sources of GHG emissions: first, direct and indirect emissions associated with the construction of the plants; second, emissions from decaying biomass from land flooded by hydro reservoirs. In terms of GHG emissions, this paper shows that, in most cases, hydropower is a good alternative to fossil fuelled power generation. For hydropower plants in cold climate, a typical GHG emission factor is 15 g CO 2 equivalent/kWh, which is 30-60 times less than the factors of usual fossil fuel generation. For some hydropower plants in tropical climates, theoretical calculations have shown that reservoir emissions could be very high. However, no measurements of emission were taken from tropical reservoirs and the current level of research does not allow for a reliable evaluation. Research is urgently needed in humid tropical climates. (author)
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.
Energy Technology Data Exchange (ETDEWEB)
Jepsen, Dirk; Reintjes, Norbert [Institut fuer Oekologie und Politik GmbH (OEKOPOL), Hamburg (Germany); Rubik, Frieder; Stecker, Rebecca; Engel, Florian; Eisenhauer, Patrik [Institut fuer Oekologische Wirtschaftsforschung (IOEW) gGmbH, Berlin (Germany); Schomerus, Thomas; Spengler, Laura [Leuphana Univ., Lueneburg (Germany)
2011-06-15
This publication shows that the environmental ministers of the EU member states are largely agreed that a new generation of green legislation with dynamic standards is needed in order to create strong incentives for resource-efficient innovation. The German Federal Government has recognised the potential of this approach and is making a political drive for the introduction of a top-runner promotion scheme at EU level. A scheme of the same kind has also been incorporated in Germany's energy efficiency action plan. The top runner promotion scheme is a system of requirements and incentives for the promotion of the best and most efficient products on the market. It can also serve as a guiding model for product-related environmental protection in Germany. In its general considerations of the interaction between community law and national law in the implementation of the top runner promotion scheme on the basis of the Ecodesign Directive and in a special analysis based on the example of boilers and small-scale firing installations the present study shows that there is a trend of steady curtailment of the legislator's scope of influence. If any national scope for product-related regulation does still exist, then only in niches, but not in a manner that would permit the legal implementation of broad concepts.
Hydropower development and the meaning of place. Multi-ethnic hydropower struggles in Sikkim, India
Dukpa, Rinchu Doma; Joshi, Deepa; Boelens, Rutgerd
2018-01-01
Academic research and media tend to emphasize the strong opposition to hydropower development in Sikkim, India, and position this as resistance to an environmentally-destructive, trans-local development, particularly by the culturally-rooted, ethnic minority Bhutia and Lepcha communities. There are
Isokinetic analysis of ankle and ground reaction forces in runners and triathletes
Directory of Open Access Journals (Sweden)
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.
Disappearing rivers — The limits of environmental assessment for hydropower in India
International Nuclear Information System (INIS)
Erlewein, Alexander
2013-01-01
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
High-resolution assessment of global technical and economic hydropower potential
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
77 FR 2286 - Northern Illinois Hydropower, LLC; Notice of Meeting
2012-01-17
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 12717-002] Northern Illinois Hydropower, LLC; Notice of Meeting a. Date and Time of Meeting: Thursday, January 26, 2012 from 11... Meeting: Commission staff will meet with Northern Illinois Hydropower, LLC to discuss potentially moving...
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.
MR imaging of the knee in marathon runners before and after competition
International Nuclear Information System (INIS)
Krampla, W.; Mayrhofer, R.; Malcher, J.; Urban, M.; Hruby, W.; Kristen, K.H.
2001-01-01
Objective. To evaluate the findings in MRI-studies of the knee in recreational long-distance runners after competition and to assess the reversibility of the findings.Design and patients. Eight recreational long-distance runners underwent MRI studies of the knee before, immediately after and 6-8 weeks after taking part in the Vienna City Marathon. The studies were evaluated regarding alterations of pre-existing lesions and new pathological findings.Results. In six runners without major pre-existing alterations no negative effects were experienced. In one runner with pre-existing grade III alterations of the menisci, signs of progressive osteoarthritis were experienced 2 months after the competition. In all other cases increased meniscal signal alterations and minor signal changes in the bone marrow after the race were transitory.Conclusion. In healthy individuals no negative long-term-effects were experienced. Pre-existing high-grade lesions of the menisci might be a predisposing risk for osteoarthritis, triggered by the stress of long-distance running. (orig.)
Reid, Stephen A; King, M Jonathan
2007-07-01
To determine if exercise-associated hyponatremia (EAH) was a cause of morbidity among runners requiring medical care at an Australian mountain ultramarathon. Case series. Six Foot Track mountain ultramarathon, New South Wales, Australia, March 2006. Runners presenting to the medical facility. Serum biochemistry. No cases of exercise-associated hyponatremia were identified among 9 athletes (from 775 starters) who were treated with intravenous fluid therapy. Unwell runners had a mean serum (Na) of 143 mmol/L (range 138-147 mmol/L). All runners tested had elevated serum urea and creatinine concentrations. In this setting, EAH was not a significant cause of morbidity.
Unsteady load on an oscillating Kaplan turbine runner
Puolakka, O.; Keto-Tokoi, J.; Matusiak, J.
2013-02-01
A Kaplan turbine runner oscillating in turbine waterways is subjected to a varying hydrodynamic load. Numerical simulation of the related unsteady flow is time-consuming and research is very limited. In this study, a simplified method based on unsteady airfoil theory is presented for evaluation of the unsteady load for vibration analyses of the turbine shaft line. The runner is assumed to oscillate as a rigid body in spin and axial heave, and the reaction force is resolved into added masses and dampings. The method is applied on three Kaplan runners at nominal operating conditions. Estimates for added masses and dampings are considered to be of a magnitude significant for shaft line vibration. Moderate variation in the added masses and minor variation in the added dampings is found in the frequency range of interest. Reference results for added masses are derived by solving the boundary value problem for small motions of inviscid fluid using the finite element method. Good correspondence is found in the added mass estimates of the two methods. The unsteady airfoil method is considered accurate enough for design purposes. Experimental results are needed for validation of unsteady load analyses.
Coherence between institutions and technologies - The case of mini hydropower in Switzerland
Crettenand, Nicolas
2009-01-01
Switzerland, with the forecasted electricity gap between domestic production and demand, aims to significantly increase renewable energy sources including hydropower. Mini hydropower (below 1MW) currently has considerable unused technical potential. As a renewable energy source (RES) it can contribute to climate change mitigation. CO2-taxes or emission trading systems (ETS) for planned thermal power plants could help facilitate mini hydropower (MHP). The technology is mature, but requires ade...
Directory of Open Access Journals (Sweden)
E. L. Mikhalyuk
2014-04-01
Full Text Available Aims. To determine the autonomic provision of the central hemodynamics and physical performance in middle distance sportswomen-runners. Methods and results. A comprehensive survey of 34 sportswomen-sprinters, qualifications from II-III level to the IMS, was carried out. For the analysis of vegetative cardiovascular regulation mathematical methods of HRV were used. In middle distance sportswomen-runners with qualifications of MS-IMS parasympathetic link of autonomic nervous system, hypokinetic types of circulation, large quantities of physical performance and index of functional state prevail compared with sportswomen-runners with qualifications of CMS, I-st, II-nd and III-rd level. Conclusion. Correlation analysis showed a significant interconnection, indicating that the optimal vegetative providing of training process of middle distance runners is accompanied by hypokinetic TC and high digits of PWC170/kg and IFS.
Evaluating the marginal utility principle for long-term hydropower scheduling
International Nuclear Information System (INIS)
Zhao, Tongtiegang; Zhao, Jianshi; Liu, Pan; Lei, Xiaohui
2015-01-01
Highlights: • Analysis of one-, two- and multi-period hydropower scheduling. • Derivation of marginal cost and marginal return of carry-over storage. • Evaluation of the marginal utility principle in a case study of the Three Gorges Reservoir. - Abstract: The conversion of the potential energy of dammed water into hydropower depends on both reservoir storage and release, which are the major difficulties in hydropower reservoir operation. This study evaluates the marginal utility principle, which determines the optimal carry-over storage between periods, for long-term hydropower scheduling. Increasing marginal cost and decreasing marginal return are two important characteristics that determine the marginal utility principle in water supply. However, the notion of decreasing marginal return is inapplicable in hydropower scheduling. Instead, the carry-over storage from one period has an increasing marginal contribution to the power generation in the next period. Although carry-over storage incurs an increasing marginal cost to the power generation in the current period, the marginal return is higher than the marginal cost. The marginal return from the carry-over storage further increases in the multi-period case. These findings suggest saving as much carry-over storage as possible, which is bounded by the operational constraints of storage capacity, environmental flow, and installed capacity in actual hydropower scheduling. The marginal utility principle is evaluated for a case study of the Three Gorges Reservoir, and the effects of the constraints are discussed. Results confirm the theoretical findings and show that the marginal return from carry-over storage is larger than the marginal cost. The operational constraints help determine the optimal carry-over storage.
International Nuclear Information System (INIS)
Brookshier, P.; Newman, Gemma
2001-01-01
The latest US research into ways of reducing the harm to fish from hydroelectric turbines is outlined. Laboratory studies, field studies and advanced computational studies are being carried out to improve the understanding of and reduce the effects of stress and injury to fish from turbines. The Advanced Hydro Turbine System programme is part of the Department of Energy's Hydropower Programme. Turbine passage injuries are caused by a number of mechanisms, leaving the fish either dead or stunned. Advanced turbine technology can help to minimise fish injury and can add dissolved oxygen to the discharged water, thus improving water quality. Turbine modifications are aimed at all species, but studies have focussed on salmon, trout and eels. The new minimum gap runner (MGR) appear as efficient as standard Kaplan turbines
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…
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.
The future of hydropower in Europe: Interconnecting climate, markets and policies
International Nuclear Information System (INIS)
Gaudard, Ludovic; Romerio, Franco
2014-01-01
Highlights: • Connecting the knowledges from various domains, in particular economics, engineering, policy and hydrology. • Giving the keys to assess the linking between hydropower, climate and electricity market. • Making an overall analysis. - Abstract: Hydropower is very important for electricity supply security in the European inter-connexion as well as for the economy of regions (primarily peripheral) that possess water resources. Its future may however be jeopardized by several factors: climate change, the development of new renewable energy, the creation of super and micro-grids, and progress in power storage technology. Energy and climate policy, as well as electricity market design and dynamics play a pivotal role. This article carries out a comprehensive analysis of all these factors and discusses the future of hydropower. This discussion follows an overview of the present situation and of future drivers. The technical, environmental, economic and political aspects of the problem are analyzed with an interdisciplinary approach. The stakes as well as the uncertainties are highlighted. The conclusion is that hydropower has a promising future, particularly in light of emerging sustainable energy policy, but that the risks should not be overlooked. Academics will find a comprehensive interdisciplinary analysis of hydropower in this article, whereas public bodies, communities and hydropower companies can identify the strategic variables that should be taken into consideration in the decision making process. The end of water concessions or authorizations is also evoked
Chen, T L; An, W W; Chan, Z Y S; Au, I P H; Zhang, Z H; Cheung, R T H
2016-03-01
Tibial stress fracture is a common injury in runners. This condition has been associated with increased impact loading. Since vertical loading rates are related to the landing pattern, many heelstrike runners attempt to modify their footfalls for a lower risk of tibial stress fracture. Such effect of modified landing pattern remains unknown. This study examined the immediate effects of landing pattern modification on the probability of tibial stress fracture. Fourteen experienced heelstrike runners ran on an instrumented treadmill and they were given augmented feedback for landing pattern switch. We measured their running kinematics and kinetics during different landing patterns. Ankle joint contact force and peak tibial strains were estimated using computational models. We used an established mathematical model to determine the effect of landing pattern on stress fracture probability. Heelstrike runners experienced greater impact loading immediately after landing pattern switch (Ptibial strains and the risk of tibial stress fracture in runners with different landing patterns (P>0.986). Immediate transitioning of the landing pattern in heelstrike runners may not offer timely protection against tibial stress fracture, despite a reduction of impact loading. Long-term effects of landing pattern switch remains unknown. Copyright © 2016 Elsevier Ltd. All rights reserved.
Sustainability Risk Evaluation for Large-Scale Hydropower Projects with Hybrid Uncertainty
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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.
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.
Valuing trade-offs of river ecosystem services in large hydropower development in Tibet, China
Yu, B.; Xu, L.
2015-12-01
Hydropower development can be considered as a kind of trade-offs of ecosystem services generated by human activity for their economic and energy demand, because it can increase some river ecosystem services but decrease others. In this context, an ecosystem service trade-off framework in hydropower development was proposed in this paper. It aims to identify the ecological cost of river ecosystem and serve for the ecological compensation during hydropower development, for the hydropower services cannot completely replace the regulating services of river ecosystem. The valuing trade-offs framework was integrated by the influenced ecosystem services identification and ecosystem services valuation, through ecological monitoring and ecological economic methods, respectively. With a case study of Pondo hydropower project in Tibet, China, the valuing trade-offs of river ecosystem services in large hydropower development was illustrated. The typical ecological factors including water, sediment and soil were analyzed in this study to identify the altered river ecosystem services by Pondo hydropower project. Through the field monitoring and valuation, the results showed that the Lhasa River ecosystem services value could be changed annually by Pondo hydropower project with the increment of 5.7E+8CNY, and decrement of 5.1E+7CNY. The ecological compensation for river ecosystem should be focus on water and soil conservation, reservoir dredging and tributaries habitat protection.
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.
Predictor Variables for Marathon Race Time in Recreational Female Runners
Schmid, Wiebke; Knechtle, Beat; Knechtle, Patrizia; Barandun, Ursula; Rüst, Christoph Alexander; Rosemann, Thomas; Lepers, Romuald
2012-01-01
Purpose 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. Methods 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-varia...
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.
Risk factors for stress fracture among young female cross-country runners.
Kelsey, Jennifer L; Bachrach, Laura K; Procter-Gray, Elizabeth; Nieves, Jeri; Greendale, Gail A; Sowers, Maryfran; Brown, Byron W; Matheson, Kim A; Crawford, Sybil L; Cobb, Kristin L
2007-09-01
To identify risk factors for stress fracture among young female distance runners. Participants were 127 competitive female distance runners, aged 18-26, who provided at least some follow-up data in a randomized trial among 150 runners of the effects of oral contraceptives on bone health. After completing a baseline questionnaire and undergoing bone densitometry, they were followed an average of 1.85 yr. Eighteen participants had at least one stress fracture during follow-up. Baseline characteristics associated (Pstress fracture occurrence were one or more previous stress fractures (rate ratio [RR] [95% confidence interval]=6.42 (1.80-22.87), lower whole-body bone mineral content (RR=2.70 [1.26-5.88] per 1-SD [293.2 g] decrease), younger chronologic age (RR=1.42 [1.05-1.92] per 1-yr decrease), lower dietary calcium intake (RR=1.11 [0.98-1.25] per 100-mg decrease), and younger age at menarche (RR=1.92 [1.15-3.23] per 1-yr decrease). Although not statistically significant, a history of irregular menstrual periods was also associated with increased risk (RR=3.41 [0.69-16.91]). Training-related factors did not affect risk. The results of this and other studies indicate that risk factors for stress fracture among young female runners include previous stress fractures, lower bone mass, and, although not statistically significant in this study, menstrual irregularity. More study is needed of the associations between stress fracture and age, calcium intake, and age at menarche. Given the importance of stress fractures to runners, identifying preventive measures is of high priority.
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.
Optimization of Mangala Hydropower Station, Pakistan, using Optimization Techniques
Directory of Open Access Journals (Sweden)
Zaman Muhammad
2017-01-01
Full Text Available Hydropower generation is one of the key element in the economy of a country. The present study focusses on the optimal electricity generation from the Mangla reservoir in Pakistan. A mathematical model has been developed for the Mangla hydropower station and particle swarm and genetic algorithm optimization techniques were applied at this model for optimal electricity generation. Results revealed that electricity production increases with the application of optimization techniques at the proposed mathematical model. Genetic Algorithm can produce maximum electricity than Particle swarm optimization but the time of execution of particle swarm optimization is much lesser than the Genetic algorithm. Mangla hydropower station can produce up to 59*109 kWh electricity by using the flows optimally than 47*108 kWh production from traditional methods.
Small hydropower in Southern Africa – an overview of five countries in the region
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
2013-11-18
... Hydropower LLC; Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments, Motions To Intervene, and Competing Applications On August 14, 2013, Houtama Hydropower LLC filed an.... Hampton, CEO, Houtama Hydropower [[Page 69081
Medial tibial stress syndrome in high school cross-country runners: incidence and risk factors.
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.
A new framework for sustainable hydropower development project
Johan, Kartina; Turan, Faiz Mohd; Gani, Nur Syazwani Abdul
2018-03-01
This project studies on the establishment of a new framework for sustainable hydropower development. A hydropower development is listed as one of the prescribed activities under the Environmental Quality Order 1987. Thus, Environmental Impact Assessment (EIA) guidelines must be referred to comply with the Department of Environment (DoE) requirements. In order to execute EIA, an assessment tool that will be utilized in the final evaluation phase must be determined. The selected assessment tool that will be used is Systematic Sustainability Assessment(SSA) which is a new integrated tool to evaluate the sustainability performance. A pilot run is conducted in five different departments within the Energy Company to validate the efficiency of the SSA tool. The parameters to be evaluated are constructed aligned with the Sustainable Development Goals (SDG) to maintain the sustainability features. Consequently, the performance level of the sustainability with respect to People, Planet and Profit (3P’s) is able to be discovered during evaluation phase in the hydropower development for continuous improvement.
Time Evolution of Sublingual Microcirculatory Changes in Recreational Marathon Runners.
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.
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.
Do Running Kinematic Characteristics Change over a Typical HIIT for Endurance Runners?
García-Pinillos, Felipe; Soto-Hermoso, Víctor M; Latorre-Román, Pedro Á
2016-10-01
García-Pinillos, F, Soto-Hermoso, VM, and Latorre-Román, PÁ. Do running kinematic characteristics change over a typical HIIT for endurance runners?. J Strength Cond Res 30(10): 2907-2917, 2016-The purpose of this study was to describe kinematic changes that occur during a common high-intensity intermittent training (HIIT) session for endurance runners. Twenty-eight male endurance runners participated in this study. A high-speed camera was used to measure sagittal-plane kinematics at the first and the last run during a HIIT (4 × 3 × 400 m). The dependent variables were spatial-temporal variables, joint angles during support and swing, and foot strike pattern. Physiological variables, rate of perceived exertion, and athletic performance were also recorded. No significant changes (p ≥ 0.05) in kinematic variables were found during the HIIT session. Two cluster analyses were performed, according to the average running pace-faster vs. slower, and according to exhaustion level reached-exhausted group vs. nonexhausted group (NEG). At first run, no significant differences were found between groups. As for the changes induced by the running protocol, significant differences (p ≤ 0.05) were found between faster and slower athletes at toe-off in θhip and θknee, whereas some changes were found in NEG in θhip during toe-off (+4.3°) and θknee at toe-off (-5.2°) during swing. The results show that a common HIIT session for endurance runners did not consistently or substantially perturb the running kinematics of trained male runners. Additionally, although some differences between groups have been found, neither athletic performance nor exhaustion level reached seems to be determinant in the kinematic response during a HIIT, at least for this group of moderately trained endurance runners.
Economic implications of climate-driven trends in global hydropower generation
Turner, S. W. D.; Galelli, S.; Hejazi, M. I.; Clarke, L.; Edmonds, J.; Kim, S. H.
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 how these impacts could affect the composition of global electricity supply, and what those changes could mean for power sector emissions and investment needs in the 21st century. Regional hydropower projections are developed for two emissions scenarios by forcing a coupled global hydrological and dam model (1593 major hydropower dams; 54% global installed capacity) with downscaled, bias-corrected climate realizations derived from sixteen General Circulation Models (GCMs). To incorporate possible non-linearity in hydropower response to climate change, dam simulations incorporate plant specifications (e.g., maximum turbine flow), reservoir storage dynamics, reservoir bathymetry, evaporation losses and bespoke, site specific operations. Consequent impacts on regional and global-level electricity generation and associated emissions and investment costs are examined using the Global Change Assessment Model (GCAM). We show that changes in hydropower generation resulting from climate change can shift power demands onto and away from carbon intensive technologies, resulting in significant impacts on CO2 emissions for several regions. Many of these countries are also highly vulnerable to investment impacts (costs of new electricity generating facilities to make up for shortfalls in hydro), which in some cases amount to tens of billions of dollars by 2100. The Balkans region—typified by weak economies in a drying region that relies heavily on hydropower—emerges as the most vulnerable. Reduced impacts of climate change on hydropower production under a low emissions scenario coincide with increased costs of marginal power generating capacity (low emissions requires greater uptake of clean generating technologies, which are more expensive). This means impacts on power sector investment costs are similar for high
Modelling and controlling hydropower plants
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...
Hydropower strategy for the Philippines
International Nuclear Information System (INIS)
McCandless, D.H.
1995-01-01
The government-owned National Power Corporation (NPC) of the Philippines is in the early stages of a complete privatisation programme. The electric power sector is expected eventually to be structured around a company that will own the major transmission facilities and will serve as a broker of power and energy between generating companies and the existing distribution companies, Rural Electric Co-operations and other power users. NPC's non-transmission assets will probably be spun-off into various corporations including three generating companies, an engineering and services company and a company owning the Calivaya-Botocan-Kalayaan hydro complex. Plans for increased capacity include a real term increase in the hydropower contribution although it will decline as a percentage of the energy mix as coal and gas plants are developed. Details of the privatisation of specific hydropower projects in the Luzon, Visayas and Mindanao grids are described. (U.K.)
Hydropower recovery in water supply systems: Models and case study
International Nuclear Information System (INIS)
Vilanova, Mateus Ricardo Nogueira; Balestieri, José Antônio Perrella
2014-01-01
Highlights: • We present hydropower recovery models for water supply systems. • Hydropower recovery potential in water supply systems is highly variable. • The case studied could make the supply systems self-sufficient in terms of energy. • Hydropower recovery can reduce GHGs emissions and generate carbon credits. - Abstract: The energy efficiency of water supply systems can be increased through the recovery of hydraulic energy implicit to the volumes of water transported in various stages of the supply process, which can be converted into electricity through hydroelectric recovery systems. Such a process allows the use of a clean energy source that is usually neglected in water supplies, reducing its dependence on energy from the local network and the system’s operation costs. This article evaluates the possibilities and benefits of the use of water supply facilities, structures and equipment for hydraulic energy recovery, addressing several applicable hydroelectric models. A real case study was developed in Brazil to illustrate the technical, economic and environmental aspects of hydropower recovery in water supply systems
Analysis of the cost for the refurbishment of small hydropower plants
International Nuclear Information System (INIS)
Ogayar, B.; Vidal, P.G.; Hernandez, J.C.
2009-01-01
In view of all the concerns associated with fossil fuels and energy demand it is appropriate to investigate the large number of abandoned small hydropower plants. In order to solve the difficulty implied, by a viability study on the refurbishment of a small hydropower plant, a series of simple equations has been developed based on the economic optimization of the different elements. These equations can also be used for completely new hydropower plants. The result of this study will allow us to obtain quite approximate costs for the refurbishment of old hydropower plants, or the construction of new ones. These data on costs will act as a reference to examine real possibilities of refurbishment through different tools of financial and economic analysis. Although the equations developed have used unitary prices referring to Spain, they will be applicable to other countries just changing those prices for those of the country, required. (author)
Can self-reported BMI be used as a valid measure among novice runners
DEFF Research Database (Denmark)
Juul, Martin Serup; Nielsen, R.O.; Rasmussen, Sten
There is an increased risk of running related injuries (RRI) among novice runners with a Body Mass Index (BMI) above 25. Information about BMI can be collected through questionnaires, when studies investigate if there is an association between BMI and RRI among novice runners. But can self...... of RRI. Healthy novice runners between the age of 18 to 65 and without lower extremity injuries were able to participate in the study. During July and August 2011 the participants were included in the study based on an online questionnaire. 1532 persons completed the questionnaire, of these, 970 were...
Hydropower reservoirs: cytotoxic and genotoxic assessment using the Allium cepa root model.
Rambo, Cassiano Lazarotto; Zanotelli, Patrícia; Dalegrave, Daniela; De Nez, Dinara; Szczepanik, Jozimar; Carazek, Fábio; Franscescon, Francini; Rosemberg, Denis Broock; Siebel, Anna Maria; Magro, Jacir Dal
2017-03-01
Hydropower offers a reliable source of electricity in several countries, and Brazil supplies its energy needs almost entirely through hydropower plants. Nevertheless, hydropower plants comprise large buildings and water reservoirs and dams, resulting in huge ecological disruptions. Here, we analyzed the impact of four hydropower reservoirs construction in metals and pesticides incidence and the cytotoxic and genotoxic potential of sediment elutriate of rivers from southern Brazil. Our analyses have evidenced the elevated incidence of different metals (lead, iron, cadmium, and chrome) and pesticides (methyl parathion, atrazine, and 2,4-dichlorophenoxyacetic acid). We showed that Allium cepa exposed to sediment elutriates did not change the seed germination rate and mitotic index. However, roots from Allium cepa exposed to reservoirs sediment elutriates showed increased occurrence of chromosomal aberrations and nuclear abnormalities. Therefore, the results obtained in our study indicate that sediment from reservoirs present elevated concentration of metals and pesticides and a significant genotoxic potential. Taken together, our data support that hydropower reservoirs represent an environmental scenario that could impact surrounding wildlife and population.
Arming and firing system for DISTANT RUNNER
International Nuclear Information System (INIS)
Skenandore, L.H.; Johnson, J.P.
1982-01-01
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
Assessing residual hydropower potential of the La Plata Basin accounting for future user demands
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.
Climate change impacts and greenhouse gas mitigation effects on U.S. hydropower generation
International Nuclear Information System (INIS)
Boehlert, Brent; Strzepek, Kenneth M.; Gebretsadik, Yohannes; Swanson, Richard; McCluskey, Alyssa; Neumann, James E.; McFarland, James; Martinich, Jeremy
2016-01-01
Highlights: • Analyze contiguous U.S. hydropower generation under various emissions scenarios. • Employ systems model that allocates water to competing uses in 2119 river basins. • Average U.S. generation increases under climate change, but falls under low flows. • Mitigation benefits are $2-$4 billion/year due to high values of carbon-free energy. - Abstract: Climate change will have potentially significant effects on hydropower generation due to changes in the magnitude and seasonality of river runoff and increases in reservoir evaporation. These physical impacts will in turn have economic consequences through both producer revenues and consumer expenditures. We analyze the physical and economic effects of changes in hydropower generation for the contiguous U.S. in futures with and without global-scale greenhouse gas (GHG) mitigation, and across patterns from 18 General Circulation Models. Using a monthly water resources systems model of 2119 river basins that routes simulated river runoff through reservoirs, and allocates water to potentially conflicting and climate dependent demands, we provide a first-order estimate of the impacts of various projected emissions outcomes on hydropower generation, and monetize these impacts using outputs from an electric sector planning model for over 500 of the largest U.S. hydropower facilities. We find that, due to generally increasing river runoff under higher emissions scenarios in the Pacific Northwest, climate change tends to increase overall hydropower generation in the contiguous U.S. During low flow months, generation tends to fall with increasing emissions, potentially threatening the estimated low flow, firm energy from hydropower. Although global GHG mitigation slows the growth in hydropower generation, the higher value placed on carbon-free hydropower leads to annual economic benefits ranging from $1.8 billion to $4.3 billion. The present value of these benefits to the U.S. from global greenhouse gas
Long-term scheduling of large cascade hydropower stations in Jinsha River, China
International Nuclear Information System (INIS)
Wang, Chao; Zhou, Jianzhong; Lu, Peng; Yuan, Liu
2015-01-01
Highlights: • Proposing a Gaussian group selection strategy to overcome premature convergence. • Multi-population ant are developed to enhance the search ability. • Proposing a circulatory solution correction to handle constraints. • Numerical and real hydropower system simulation are used to verify its performance. • Compensation analysis has been done to large hydropower stations in Jinsha River. - Abstract: The Jinsha River is the third longest river in the world. It consists of four large hydropower stations with total installed capacity 42,960 MW lying on the upper stretches of the Yangtze River, which is the longest river in the word. Due to the great potential of large cascade hydropower stations on power generation, long-term scheduling of large cascade hydropower stations (LSLCHS) plays an important role in electrical power system. As more and more concentrations focused on the optimal operation of large cascade hydropower stations, the LSLCHS has been taken into a multi-dimensional, non-convex and non-linear optimization problem due to its complicated hydraulic connection relationships and varieties of complex constraints with considering its power generation, shipping and ecological characteristics. In order to solve this problem, a multi-population ant colony optimization for continuous domain (MACO R ) is proposed in this paper. A Gaussian group selection strategy is applied to overcome premature convergence and ants with different characteristics are employed to enhance search ability, and circulatory solution correction strategy is presented to handle outflow, water level and output constraints. Furthermore, the efficiency and stability of MACO R are verified by its more desirable results in comparison to other latest works in numerical simulation, and it can be a viable alternative for solving those complicated optimal problems. With the applications in hydropower operation, LSLCHS can obtain more power generation benefit than other
Multiobjective optimal design of runner blade using efficiency and draft tube pulsation criteria
International Nuclear Information System (INIS)
Pilev, I M; Sotnikov, A A; Rigin, V E; Semenova, A V; Cherny, S G; Chirkov, D V; Bannikov, D V; Skorospelov, V A
2012-01-01
In the present work new criteria of optimal design method for turbine runner [1] are proposed. Firstly, based on the efficient method which couples direct simulation of 3D turbulent flow and engineering semi empirical formulas, the combined method is built for hydraulic energy losses estimation in the whole turbine water passage and the efficiency criterion is formulated. Secondly, the criterion of dynamic loads minimization is developed for those caused by vortex rope precession downstream of the runner. This criterion is based on the finding that the monotonic increase of meridional velocity component in the direction to runner hub, downstream of its blades, provides for decreasing the intensity of vortex rope and thereafter, minimization of pressure pulsation amplitude. The developed algorithm was applied to optimal design of 640 MW Francis turbine runner. It can ensure high efficiency at best efficiency operating point as well as diminished pressure pulsations at full load regime.
International Nuclear Information System (INIS)
Miclosina, C O; Balint, D I; Campian, C V; Frunzaverde, D; Ion, I
2012-01-01
This paper deals with the optimization of the axial hydraulic turbines of Kaplan type. The optimization of the runner blade is presented systematically from two points of view: hydrodynamic and constructive. Combining these aspects in order to gain a safer operation when unsteady effects occur in the runner of the turbine is attempted. The design and optimization of the runner blade is performed with QTurbo3D software developed at the Center for Research in Hydraulics, Automation and Thermal Processes (CCHAPT) from 'Eftimie Murgu' University of Resita, Romania. QTurbo3D software offers possibilities to design the meridian channel of hydraulic turbines design the blades and optimize the runner blade. 3D modeling and motion analysis of the runner blade operating mechanism are accomplished using SolidWorks software. The purpose of motion study is to obtain forces, torques or stresses in the runner blade operating mechanism, necessary to estimate its lifetime. This paper clearly states the importance of combining the hydrodynamics with the structural design in the optimization procedure of the runner of hydraulic turbines.
Miclosina, C. O.; Balint, D. I.; Campian, C. V.; Frunzaverde, D.; Ion, I.
2012-11-01
This paper deals with the optimization of the axial hydraulic turbines of Kaplan type. The optimization of the runner blade is presented systematically from two points of view: hydrodynamic and constructive. Combining these aspects in order to gain a safer operation when unsteady effects occur in the runner of the turbine is attempted. The design and optimization of the runner blade is performed with QTurbo3D software developed at the Center for Research in Hydraulics, Automation and Thermal Processes (CCHAPT) from "Eftimie Murgu" University of Resita, Romania. QTurbo3D software offers possibilities to design the meridian channel of hydraulic turbines design the blades and optimize the runner blade. 3D modeling and motion analysis of the runner blade operating mechanism are accomplished using SolidWorks software. The purpose of motion study is to obtain forces, torques or stresses in the runner blade operating mechanism, necessary to estimate its lifetime. This paper clearly states the importance of combining the hydrodynamics with the structural design in the optimization procedure of the runner of hydraulic turbines.
Development of Sustainability Assessment Framework in Hydropower sector
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.
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.
Hydropower, an integral part of Canada's climate change strategy
International Nuclear Information System (INIS)
Fortin, P.
1999-01-01
The development and implementation of a climate change policy could be among the most far-reaching environmental initiatives ever embarked upon in Canada and abroad. If Canada is to stabilize or reduce its Greenhouse Gas (GHG) emissions over the long term, a significant adjustment to Canadian industry will be required as we move away from fossil fuel-intensive and GHG producing activities. Future hydroelectric projects provide Canada with a unique opportunity to significantly reduce the costs associated with stabilizing its GHG emissions. In addition, the energy storage and dispatchability associated with hydropower can support development of other low emitting renewable resources such as wind and solar. This document discusses the potential role of hydropower as a tool to reduce emissions, recommends action to reduce barriers facing hydropower and comments on some of the policy tools available to manage Canada's GHG emissions. (author)
Factors affecting running economy in trained distance runners.
Saunders, Philo U; Pyne, David B; Telford, Richard D; Hawley, John A
2004-01-01
Running economy (RE) is typically defined as the energy demand for a given velocity of submaximal running, and is determined by measuring the steady-state consumption of oxygen (VO2) and the respiratory exchange ratio. Taking body mass (BM) into consideration, runners with good RE use less energy and therefore less oxygen than runners with poor RE at the same velocity. There is a strong association between RE and distance running performance, with RE being a better predictor of performance than maximal oxygen uptake (VO2max) in elite runners who have a similar VO2max). RE is traditionally measured by running on a treadmill in standard laboratory conditions, and, although this is not the same as overground running, it gives a good indication of how economical a runner is and how RE changes over time. In order to determine whether changes in RE are real or not, careful standardisation of footwear, time of test and nutritional status are required to limit typical error of measurement. Under controlled conditions, RE is a stable test capable of detecting relatively small changes elicited by training or other interventions. When tracking RE between or within groups it is important to account for BM. As VO2 during submaximal exercise does not, in general, increase linearly with BM, reporting RE with respect to the 0.75 power of BM has been recommended. A number of physiological and biomechanical factors appear to influence RE in highly trained or elite runners. These include metabolic adaptations within the muscle such as increased mitochondria and oxidative enzymes, the ability of the muscles to store and release elastic energy by increasing the stiffness of the muscles, and more efficient mechanics leading to less energy wasted on braking forces and excessive vertical oscillation. Interventions to improve RE are constantly sought after by athletes, coaches and sport scientists. Two interventions that have received recent widespread attention are strength training and
Prevalence of allergy and upper respiratory tract symptoms in runners of the London marathon.
Robson-Ansley, Paula; Howatson, Glyn; Tallent, Jamie; Mitcheson, Kelly; Walshe, Ian; Toms, Chris; DU Toit, George; Smith, Matt; Ansley, Les
2012-06-01
The prevalence of self-reported upper respiratory tract (URT) symptoms in athletes has been traditionally associated with opportunistic infection during the temporal suppression of immune function after prolonged exercise. There is little evidence for this, and a competing noninfectious hypothesis has been proposed, whereby the exercise-induced immune system modulations favor the development of atopy and allergic disease, which manifests as URT symptoms. The aim of this study was to examine the association between allergy and URT symptoms in runners after an endurance running event. Two hundred eight runners from the 2010 London Marathon completed the validated Allergy Questionnaire for Athletes (AQUA) and had serum analyzed for total and specific immunoglobulin E response to common inhalant allergens. Participants who completed the marathon and nonrunning controls who lived in the same household were asked to complete a diary on URT symptoms. Forty percent of runners had allergy as defined by both a positive AQUA and elevated specific immunoglobulin E. Forty-seven percent of runners experienced URT symptoms after the marathon. A positive AQUA was a significant predictor of postmarathon URT symptoms in runners. Only 19% of nonrunning controls reported symptoms. The prevalence of allergy in recreational marathon runners was similar to that in elite athletes and higher than that in the general population. There was a strong association between a positive AQUA and URT symptoms. The low proportion of households in which both runners and nonrunners were symptomatic suggests that the nature of symptoms may be allergic or inflammatory based rather than infectious. Allergy is a treatable condition, and its potential effect on performance and health may be avoided by accurate clinical diagnosis and management. Both athletes' and coaches' awareness of the potential implications of poorly managed allergy needs to be raised.
Comparison of running and cycling economy in runners, cyclists, and triathletes.
Swinnen, Wannes; Kipp, Shalaya; Kram, Rodger
2018-07-01
Exercise economy is one of the main physiological factors determining performance in endurance sports. Running economy (RE) can be improved with running-specific training, while the improvement of cycling economy (CE) with cycling-specific training is controversial. We investigated whether exercise economy reflects sport-specific skills/adaptations or is determined by overall physiological factors. We compared RE and CE in 10 runners, 9 cyclists and 9 triathletes for running at 12 km/h and cycling at 200 W. Gross rates of oxygen consumption and carbon dioxide production were collected and used to calculate gross metabolic rate in watts for both running and cycling. Runners had better RE than cyclists (917 ± 107 W vs. 1111 ± 159 W) (p < 0.01). Triathletes had intermediate RE values (1004 ± 98 W) not different from runners or cyclists. CE was not different (p = 0.20) between the three groups (runners: 945 ± 60 W; cyclists: 982 ± 44 W; triathletes: 979 ± 54 W). RE can be enhanced with running-specific training, but CE is independent of cycling-specific training.
Food and macronutrient intake of male adolescent Kalenjin runners in Kenya
DEFF Research Database (Denmark)
Christensen, Dirk L; Van Hall, Gerrit; Hambraeus, Leif
2002-01-01
A nutritional survey based on twelve adolescent male Kalenjin runners in Kenya during a 2-week field study was carried out in order to determine the composition of their diet and make a comparison with macronutrient recommendations for athletes. Food samples were collected for analysis of macronu......A nutritional survey based on twelve adolescent male Kalenjin runners in Kenya during a 2-week field study was carried out in order to determine the composition of their diet and make a comparison with macronutrient recommendations for athletes. Food samples were collected for analysis...... of macronutrient distribution and energy content from main meals and the macronutrient distribution and energy content of additional food intake were based on the information of a 24 h recall interview and estimated from food tables. The diet of the Kalenjin runners was very high in carbohydrate (71 % 8.7 g...
Environmental certification for small hydropower plants
International Nuclear Information System (INIS)
Truffer, B.; Meier, W.; Vollenweider, S.; Seiler, B.; Dettli, R.
2001-01-01
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
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.
2013-10-09
... District; Notice of Preliminary Determination of a Qualifying Conduit Hydropower Facility and Soliciting... construct a qualifying conduit hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the Hydropower Regulatory Efficiency Act of 2013 (HREA). The Corbett Hydroelectric...
2012-09-20
... Hydropower, LLC; Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments, Motions To Intervene, and Competing Applications On May 18, 2012, Inglis Hydropower, LLC filed an... study the feasibility of a hydropower project located at the Inglis Bypass Channel, located on the...
2010-09-28
... Hydropower, LLC; Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments... on July 16, 2010, Coastal Hydropower, LLC filed an application for a preliminary permit, pursuant to... generation of the project would be 7.9 gigawatt-hours. Applicant Contact: Neil Anderson, Coastal Hydropower...
2012-05-25
... Hydropower, LLC; Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments, Motions To Intervene, and Competing Applications On April 12, 2012, Coastal Hydropower, LLC filed an... generation of 31.5 gigawatt-hours. Applicant Contact: Neil Anderson, Coastal Hydropower, LLC, Key Centre, 601...
Hydraulic design and optimization of a modular pump-turbine runner
International Nuclear Information System (INIS)
Schleicher, W.C.; Oztekin, A.
2015-01-01
Highlights: • A modular pumped-storage scheme using elevated water storage towers is investigated. • The pumped-storage scheme also aides in the wastewater treatment process. • A preliminary hydraulic pump-turbine runner design is created based on existing literature. • The preliminary design is optimized using a response surface optimization methodology. • The performance and flow fields between preliminary and optimized designs are compared. - Abstract: A novel modular pumped-storage scheme is investigated that uses elevated water storage towers and cement pools as the upper and lower reservoirs. The scheme serves a second purpose as part of the wastewater treatment process, providing multiple benefits besides energy storage. A small pumped-storage scheme has been shown to be a competitive energy storage solution for micro renewable energy grids; however, pumped-storage schemes have not been implemented on scales smaller than megawatts. Off-the-shelf runner designs are not available for modular pumped-storage schemes, so a custom runner design is sought. A preliminary hydraulic design for a pump-turbine runner is examined and optimized for increased pumping hydraulic efficiency using a response surface optimization methodology. The hydraulic pumping efficiency was found to have improved by 1.06% at the best efficiency point, while turbine hydraulic efficiency decreased by 0.70% at the turbine best efficiency point. The round-trip efficiency for the system was estimated to be about 78%, which is comparable to larger pumped-storage schemes currently in operation
Time Evolution of Sublingual Microcirculatory Changes in Recreational Marathon Runners
Arstikyte, Justina; Vaitkaitiene, Egle; Vaitkaitis, Dinas
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. PMID:28828386
Resource rent taxation and benchmarking-A new perspective for the Swiss hydropower sector
International Nuclear Information System (INIS)
Banfi, Silvia; Filippini, Massimo
2010-01-01
The electricity generation in Switzerland is mainly based on hydropower (55% of total production). The exploitation of water in the hydropower sector can generate significant so-called resource rents. These are defined by the surplus return above the value of capital, labor, materials, and energy used to exploit hydropower. In Switzerland, hydropower producers pay to the State a fixed fee per kW gross capacity. With this system the substantial differences in costs, revenues and in the production characteristics of the hydropower plants are not taken into account. In this context, the following paper has two main goals: (1) to discuss the introduction in the Swiss hydropower sector of a new payment system based on a resource rent tax; (2) To propose a combination of a RRT system with a benchmarking analysis of the production cost obtained through the estimation of a stochastic frontier variable cost function. We estimate a true random effects stochastic frontier variable cost function using panel data in order to overcome the asymmetric information problem. In addition, using the information on cost efficiency of the single companies, we show how to introduce in the RRT scheme a benchmark system which gives incentives to minimize the production costs.
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.
Luedke, Lace E; Heiderscheit, Bryan C; Williams, D S Blaise; Rauh, Mitchell J
2015-11-01
High school cross country runners have a high incidence of overuse injuries, particularly to the knee and shin. As lower extremity strength is modifiable, identification of strength attributes that contribute to anterior knee pain (AKP) and shin injuries may influence prevention and management of these injuries. To determine if a relationship existed between isometric hip abductor, knee extensor and flexor strength and the incidence of AKP and shin injury in high school cross country runners. Sixty-eight high school cross country runners (47 girls, 21 boys) participated in the study. Isometric strength tests of hip abductors, knee extensors and flexors were performed with a handheld dynamometer. Runners were prospectively followed during the 2014 interscholastic cross country season for occurrences of AKP and shin injury. Bivariate logistic regression was used to examine risk relationships between strength values and occurrence of AKP and shin injury. During the season, three (4.4%) runners experienced AKP and 13 (19.1%) runners incurred a shin injury. Runners in the tertiles indicating weakest hip abductor (chi-square = 6.140; p=0.046), knee extensor (chi-square = 6.562; p=0.038), and knee flexor (chi-square = 6.140; p=0.046) muscle strength had a significantly higher incidence of AKP. Hip and knee muscle strength was not significantly associated with shin injury. High school cross country runners with weaker hip abductor, knee extensor and flexor muscle strength had a higher incidence of AKP. Increasing hip and knee muscle strength may reduce the likelihood of AKP in high school cross country runners. 2b.
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.
Long-term success and risk for marathon runners
International Nuclear Information System (INIS)
Schueller-Weidekamm, C.
2010-01-01
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. (orig.) [de
Environmental sustainability assessment of hydropower plant in Europe using life cycle assessment
Mahmud, M. A. P.; Huda, N.; Farjana, S. H.; Lang, C.
2018-05-01
Hydropower is the oldest and most common type of renewable source of electricity available on this planet. The end of life process of hydropower plant have significant environmental impacts, which needs to be identified and minimized to ensure an environment friendly power generation. However, identifying the environmental impacts and health hazards are very little explored in the hydropower processing routes despite a significant quantity of production worldwide. This paper highlight the life-cycle environmental impact assessment of the reservoir based hydropower generation system located in alpine and non-alpine region of Europe, addressing their ecological effects by the ReCiPe and CML methods under several impact-assessment categories such as human health, ecosystems, global warming potential, acidification potential, etc. The Australasian life-cycle inventory database and SimaPro software are utilized to accumulate life-cycle inventory dataset and to evaluate the impacts. The results reveal that plants of alpine region offer superior environmental performance for couple of considered categories: global warming and photochemical oxidation, whilst in the other cases the outcomes are almost similar. Results obtained from this study will take part an important role in promoting sustainable generation of hydropower, and thus towards environment friendly energy production.
2010-09-28
... Hydropower, LLC; Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments... on July 16, 2010, Coastal Hydropower, LLC filed an application for a preliminary permit, pursuant to... Hydropower, LLC, Key Centre, 601 108th Avenue, NE., Suite 1900, Bellevue, WA 98004; phone: (425) 943-7690...
2013-10-29
... Hydropower, Inc.; Notice of Subsequent Draft License Application (DLA) and Draft Preliminary Draft... Hydropower, Inc. e. Name of Project: Sweetheart Lake Hydroelectric Project. f. Location: At the confluence of..., Business Manager, Juneau Hydropower, Inc., P.O. Box 22775, Juneau, AK 99802; 907-789-2775, email: duff...
2010-10-12
... Illinois Hydropower, LLC; Notice of Application Ready for Environmental Analysis and Soliciting Comments...: Northern Illinois Hydropower, LLC. e. Name of Project: Dresden Island Project. f. Location: U.S. Army Corps... Zdunich, Northern Illinois Hydropower, LLC, 801 Oakland Avenue, Joliet, IL 60435, (312) 320-1610. i. FERC...
2013-10-23
... Preliminary Determination of a Qualifying Conduit Hydropower Facility and Soliciting Comments and Motions To... of intent to construct a qualifying conduit hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the Hydropower Regulatory Efficiency Act of 2013 (HREA). The...
2010-10-12
... Illinois Hydropower, LLC; Notice of Application Ready for Environmental Analysis and Soliciting Comments...: Northern Illinois Hydropower, LLC. e. Name of Project: Brandon Road Hydroelectric Project. f. Location: U.S... Hydropower, LLC, 801 Oakland Avenue, Joliet, IL 60435, (312) 320-1610. i. FERC Contact: Janet Hutzel, (202...
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.
Hydropower in Southeast United States, -a Hydroclimatological Perspective
Engstrom, J.
2016-12-01
Hydropower is unique among renewable energy sources for the ability to store its fuel (water) in reservoirs. The relationship between discharge, macro-scale drivers, and production is complex since production depends not only on water availability, but also upon decisions made by the institution owning the facility that has to consider many competing interests including economics, drinking water supply, recreational uses, etc. This analysis shows that the hydropower plants in Southeast U.S. (AL, GA, NC, SC, and TN) exhibit considerable year to year variability in production. Although the hydroclimatology of the Southeast U.S. has been analyzed partially, no previous study has linked the region's hydroelectricity production to any reported causes of interannual hydroclimatological variability, as has been completed in other regions. Due to the current short-term hydroelectricity production forecasts, the water resource is not optimized from a hydropower perspective as electricity generating potential is not maximized. The results of this study highlight the amount of untapped hydroelectricity that could be produced if long term hydroclimate and large-scale climate drivers were considered in production forecasts.
The multipurpose water use of hydropower reservoir: the SHARE concept
International Nuclear Information System (INIS)
Branche, E.
2017-01-01
Multipurpose hydropower reservoirs are designed and/or operated to provide services beyond electricity generation, such as water supply, flood and drought management, irrigation, navigation, fisheries, environmental services and recreational activities, etc. While these objectives (renewable and power services, water quantity management, ecosystem services, economic growth and local livelihoods) can conflict at times, they are also often complementary. Although there are no universal solutions, there are principles that can be shared and adapted to local contexts. Indeed the development and/or operation of such multipurpose hydropower reservoirs to reach sustainable water management should rely on the following principles: shared vision, shared resource, shared responsibilities, shared rights and risks, shared costs and benefits. These principles and acknowledgement of joint sharing among all the stakeholders are essential to successful development and management of multipurpose hydropower reservoirs, and should frame all phases from early stage to operation. The SHARE concept also gives guidance. Based on 12 worldwide case studies of multipurpose hydropower reservoirs, the SHARE concept was developed and proposed as a solution to address this issue. A special focus will be presented on the Durance-Verdon Rivers in France. (author)
Energy Technology Data Exchange (ETDEWEB)
Hou, Hongfei; Deng, Zhiqun; Martinez, Jayson; Fu, Tao; Duncan, Joanne; Johnson, Gary; Lu, Jun; Skalski, John; Townsend, Richard; Tan, Li
2018-04-01
Currently, approximately 16% of the world’s electricity and over 80% of the world’s renewable electricity is generated from hydropower resources, and there is potential for development of a significant amount of new hydropower capacity. However, in practice, realizing all the potential hydropower resource is limited by various factors, including environmental effects and related mitigation requirements. That is why hydropower regulatory requirements frequently call for targets to be met regarding fish injury and mortality rates. Hydropower Biological Evaluation Toolset (HBET), an integrated suite of software tools, is designed to characterize hydraulic conditions of hydropower structures and provide quantitative estimates of fish injury and mortality rates due to various physical stressors including strike, pressure, and shear. HBET enables users to design new studies, analyze data, perform statistical analyses, and evaluate biological responses. In this paper, we discuss the features of the HBET software and describe a case study that illustrates its functionalities. HBET can be used by turbine manufacturers, hydropower operators, and regulators to design and operate hydropower systems that minimize ecological impacts in a cost-effective manner.
2010-04-09
... Illinois Hydropower, LLC; Notice of Application Accepted for Filing and Soliciting Motions To Intervene and... No.: 12626-002. c. Date filed: March 31, 2009. d. Applicant: Northern Illinois Hydropower, LLC. e... Power Act, 16 U.S.C. 791(a)-825(r). h. Applicant Contact: Damon Zdunich, Northern Illinois Hydropower...
2010-05-06
... Illinois Hydropower, LLC; Notice of Application Accepted for Filing and Soliciting Motions To Intervene and... No.: 12717-002. c. Date filed: May 27, 2009. d. Applicant: Northern Illinois Hydropower, LLC. e. Name... Hydropower, LLC, 801 Oakland Avenue, Joliet, IL 60435, (312) 320-1610. i. FERC Contact: Dr. Nicholas Palso...
76 FR 12103 - Erie Boulevard Hydropower, L.P; Notice of Settlement Agreement and Soliciting Comments
2011-03-04
... Hydropower, L.P; Notice of Settlement Agreement and Soliciting Comments Take notice that the following... Boulevard Hydropower, L.P. e. Location: The existing multi-development project is located on the Oswegatchie... 791 (a)-825(r) h. Applicant Contact: Daniel Daoust, Erie Boulevard Hydropower, 33 West 1st Street...
Reliability and accuracy of Cooper's test in male long distance runners
J.R. Alvero-Cruz; M.A. Giráldez García; E.A. Carnero
2017-01-01
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 ...
Directory of Open Access Journals (Sweden)
Sen-Kuang Hou
Full Text Available Ultramarathon is a high endurance exercise associated with a wide range of exercise-related problems, such as acute kidney injury (AKI. Early recognition of individuals at risk of AKI during ultramarathon event is critical for implementing preventative strategies.To investigate the impact of speed variability to identify the exercise-related acute kidney injury anticipatively in ultramarathon event.This is a prospective, observational study using data from a 100 km ultramarathon in Taipei, Taiwan. The distance of entire ultramarathon race was divided into 10 splits. The mean and variability of speed, which was determined by the coefficient of variation (CV in each 10 km-split (25 laps of 400 m oval track were calculated for enrolled runners. Baseline characteristics and biochemical data were collected completely 1 week before, immediately post-race, and one day after race. The main outcome was the development of AKI, defined as Stage II or III according to the Acute Kidney Injury Network (AKIN criteria. Multivariate analysis was performed to determine the independent association between variables and AKI development.26 ultramarathon runners were analyzed in the study. The overall incidence of AKI (in all Stages was 84.6% (22 in 26 runners. Among these 22 runners, 18 runners were determined as Stage I, 4 runners (15.4% were determined as Stage II, and none was in Stage III. The covariates of BMI (25.22 ± 2.02 vs. 22.55 ± 1.96, p = 0.02, uric acid (6.88 ± 1.47 vs. 5.62 ± 0.86, p = 0.024, and CV of speed in specific 10-km splits (from secondary 10 km-split (10th - 20th km-split to 60th - 70th km-split were significantly different between runners with or without AKI (Stage II in univariate analysis and showed discrimination ability in ROC curve. In the following multivariate analysis, only CV of speed in 40th - 50th km-split continued to show a significant association to the development of AKI (Stage II (p = 0.032.The development of exercise
Investigation of distributor vane jets to decrease the unsteady load on hydro turbine runner blades
Lewis, B. J.; Cimbala, J. M.; Wouden, A. M.
2012-11-01
As the runner blades of a Francis hydroturbine pass though the wakes created from the wicket gates, they experience a significant change in absolute velocity, flow angle, and pressure. The concept of adding jets to the trailing edge of the wicket gates is proposed as a method for reducing the dynamic load on the hydroturbine runner blades. Computational experiments show a decrease in velocity variation experienced by the runner blade with the addition of the jets. The decrease in velocity variation resulted in a 43% decrease in global torque variation at the runner passing frequency. However, an increased variation was observed at the wicket gate passing frequency. Also, a 5.7% increase in average global torque was observed with the addition of blowing from the trailing-edge of the wicket gates.
Investigation of distributor vane jets to decrease the unsteady load on hydro turbine runner blades
International Nuclear Information System (INIS)
Lewis, B J; Cimbala, J M; Wouden, A M
2012-01-01
As the runner blades of a Francis hydroturbine pass though the wakes created from the wicket gates, they experience a significant change in absolute velocity, flow angle, and pressure. The concept of adding jets to the trailing edge of the wicket gates is proposed as a method for reducing the dynamic load on the hydroturbine runner blades. Computational experiments show a decrease in velocity variation experienced by the runner blade with the addition of the jets. The decrease in velocity variation resulted in a 43% decrease in global torque variation at the runner passing frequency. However, an increased variation was observed at the wicket gate passing frequency. Also, a 5.7% increase in average global torque was observed with the addition of blowing from the trailing-edge of the wicket gates.
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
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.
Private hydro: is it a runner?
International Nuclear Information System (INIS)
Head, C.R.
1993-01-01
The prospects for hydropower around the world is briefly reviewed. The resurgence in private development of energy sources means there is a potentially huge market which has still to be developed. Topics include site and scheme layout, hydrology and sizing, hydrological risk and financing. (UK)
India's hydropower vision to 2030 - environmental issues
International Nuclear Information System (INIS)
Goel, R.S.
2004-01-01
The economic advantages of hydropower has been enhanced in the recent years with the steep increases in the energy costs from fossil fuel and the rapid approaching limits to the exploitable resources of such fuels. It is a matter of concern that the share of hydropower in the total installed capacity in India has been declining in successive plans. In the 1962-63, hydro projects had a 50% share in the total installed capacity which has declined to 24%. Such a dismal share of hydro thermal mix is adversely affecting the optimal utilisation of natural and financial resources besides resulting in failure of power grids. Even a layman can appreciate that in the situation of monsoonic weather the storage of river flows during floods is unavoidable not only to meet the basic needs of bulging population for diverse uses but also to moderate the floods, droughts and poverty. This article focuses on the environmental issues related to hydropower and river valley projects, while pinpointing the vital need of large storage projects in India. The water is becoming scarcer in India due to bulging population; but the environmental activism and biased media reporting are creating large scale obstructions in the execution of hydro projects
The environmental impacts of peaking at hydropower plants
International Nuclear Information System (INIS)
Halleraker, Jo Halvard
2001-01-01
A recent energy act in Norway allows hydropower plants to be operated so that hydro peaking is permitted. However, it is uncertain how fish react to the variations in discharge and depth that follow hydro peaking. SINTEF Energy Research is cooperating with other research institutions to investigate the consequences of these variations on the biota. Among the research tools is an aqua channel which is an indoor laboratory flume where fish behaviour can be studied in detail. It has been constructed to provide the hydropower industry and public authorities with means of better determining the effects of hydro peaking. (author)
Microclimate Variation and Estimated Heat Stress of Runners in the 2020 Tokyo Olympic Marathon
Directory of Open Access Journals (Sweden)
Eichi Kosaka
2018-05-01
Full Text Available The Tokyo 2020 Olympic Games will be held in July and August. As these are the hottest months in Tokyo, the risk of heat stress to athletes and spectators in outdoor sporting events is a serious concern. This study focuses on the marathon races, which are held outside for a prolonged time, and evaluates the potential heat stress of marathon runners using the COMFA (COMfort FormulA Human Heat Balance (HBB Model. The study applies a four-step procedure: (a measure the thermal environment along the marathon course; (b estimate heat stress on runners by applying COMFA; (c identify locations where runners may be exposed to extreme heat stress; and (d discuss measures to mitigate the heat stress on runners. On clear sunny days, the entire course is rated as ‘dangerous’ or ‘extremely dangerous’, and within the latter half of the course, there is a 10-km portion where values continuously exceed the extremely dangerous level. Findings illustrate which stretches have the highest need for mitigation measures, such as starting the race one hour earlier, allowing runners to run in the shade of buildings or making use of urban greenery including expanding the tree canopy.
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
77 FR 27451 - Boott Hydropower, Inc.; Notice of Section 106 Consultation Meeting
2012-05-10
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 2790-055] Boott Hydropower, Inc.; Notice of Section 106 Consultation Meeting On May 24, 2012, Federal Energy Regulatory Commission... Historic Preservation, Boott Hydropower, Inc., and any other consulting parties for the section 106 process...
Hydropower assessment of Bolivia—A multisource satellite data and hydrologic modeling approach
Velpuri, Naga Manohar; Pervez, Shahriar; Cushing, W. Matthew
2016-11-28
This study produced a geospatial database for use in a decision support system by the Bolivian authorities to investigate further development and investment potentials in sustainable hydropower in Bolivia. The study assessed theoretical hydropower of all 1-kilometer (km) stream segments in the country using multisource satellite data and a hydrologic modeling approach. With the assessment covering the 2 million square kilometer (km2) region influencing Bolivia’s drainage network, the potential hydropower figures are based on theoretical yield assuming that the systems generating the power are 100 percent efficient. There are several factors to consider when determining the real-world or technical power potential of a hydropower system, and these factors can vary depending on local conditions. Since this assessment covers a large area, it was necessary to reduce these variables to the two that can be modeled consistently throughout the region, streamflow or discharge, and elevation drop or head. First, the Shuttle Radar Topography Mission high-resolution 30-meter (m) digital elevation model was used to identify stream segments with greater than 10 km2 of upstream drainage. We applied several preconditioning processes to the 30-m digital elevation model to reduce errors and improve the accuracy of stream delineation and head height estimation. A total of 316,500 1-km stream segments were identified and used in this study to assess the total theoretical hydropower potential of Bolivia. Precipitation observations from a total of 463 stations obtained from the Bolivian Servicio Nacional de Meteorología e Hidrología (Bolivian National Meteorology and Hydrology Service) and the Brazilian Agência Nacional de Águas (Brazilian National Water Agency) were used to validate six different gridded precipitation estimates for Bolivia obtained from various sources. Validation results indicated that gridded precipitation estimates from the Tropical Rainfall Measuring Mission
The oil pressure test of the hydraulic impeller blade
Ye, Wen-bo; Jia, Li-tao
2017-12-01
This article introduced the structure of the Kaplan runner in hydropower station and the operating process of the oil pressure test has been described. What’s more, the whole process, including filling oil to the runner hub, the movement of the runner blade, the oil circuit, have been presented in detail.Since the manipulation of the oil circuit which controlled by three Valve groups consisting of six valves was complicated, the author is planning to replace them with 3-position 3-way electromagnetic valves, so we can simplify the operation procedure.The author hopes this article can provide technical reference for the oil pressure test.
Foot strike patterns of runners at the 15-km point during an elite-level half marathon.
Hasegawa, Hiroshi; Yamauchi, Takeshi; Kraemer, William J
2007-08-01
There are various recommendations by many coaches regarding foot landing techniques in distance running that are meant to improve running performance and prevent injuries. Several studies have investigated the kinematic and kinetic differences between rearfoot strike (RFS), midfoot strike (MFS), and forefoot strike (FFS) patterns at foot landing and their effects on running efficiency on a treadmill and over ground conditions. However, little is known about the actual condition of the foot strike pattern during an actual road race at the elite level of competition. The purpose of the present study was to document actual foot strike patterns during a half marathon in which elite international level runners, including Olympians, compete. Four hundred fifteen runners were filmed by 2 120-Hz video cameras in the height of 0.15 m placed at the 15.0-km point and obtained sagittal foot landing and taking off images for 283 runners. Rearfoot strike was observed in 74.9% of all analyzed runners, MFS in 23.7%, and FFS in 1.4%. The percentage of MFS was higher in the faster runners group, when all runners were ranked and divided into 50 runner groups at the 15.0-km point of the competition. In the top 50, which included up to the 69th place runner in actual order who passed the 15-km point at 45 minutes, 53 second (this speed represents 5.45 m x s(-1), or 15 minutes, 17 seconds per 5 km), RFS, MFS, and FFS were 62.0, 36.0, and 2.0%, respectively. Contact time (CT) clearly increased for the slower runners, or the placement order increased (r = 0.71, p strike was observed in 42% of all runners. The percentage of INV for MFS was higher than for RFS and FFS (62.5, 32.0, and 50%, respectively). The CT with INV for MFS + FFS was significantly shorter than the CT with and without INV for RFS. Furthermore, the CT with INV was significantly shorter than push-off time without INV for RFS. The findings of this study indicate that foot strike patterns are related to running speed. The
The role of hydropower in electric power integration of Asian countries
Belyaev, Lev; Savelyev, Vladimir; Chudinova, Lyudmila
2018-01-01
The possible role of hydropower plants in formation and operation of interstate power pools is described based on the generalization of the world experience. Peculiarities of the influence of hydropower on development of interstate electric ties in this part of the world and potential effects are showed on the example of Central and Northeast Asia.
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.
The impact of global change on the hydropower potential of Europe: a model-based analysis
International Nuclear Information System (INIS)
Lehner, Bernhard; Czisch, Gregor; Vassolo, Sara
2005-01-01
This study presents a model-based approach for analyzing the possible effects of global change on Europe's hydropower potential at a country scale. By comparing current conditions of climate and water use with future scenarios, an overview is provided of today's potential for hydroelectricity generation and its mid- and long-term prospects. The application of the global water model WaterGAP for discharge calculations allows for an integrated assessment, taking both climate and socioeconomic changes into account. This study comprises two key parts: First, the 'gross' hydropower potential is analyzed, in order to outline the general distribution and trends in hydropower capabilities across Europe. Then, the assessment focuses on the 'developed' hydropower potential of existing hydropower plants, in order to allow for a more realistic picture of present and future electricity production. For the second part, a new data set has been developed which geo-references 5991 European hydropower stations and distinguishes them into run-of-river and reservoir stations. The results of this study present strong indications that, following moderate climate and global change scenario assumptions, severe future alterations in discharge regimes have to be expected, leading to unstable regional trends in hydropower potentials with reductions of 25% and more for southern and southeastern European countries
Physiological and training characteristics of recreational marathon runners.
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.
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.
[Impacts of large hydropower station on benthic algal communities].
Jia, Xing-Huan; Jiang, Wan-Xiang; Li, Feng-Qing; Tang, Tao; Duan, Shu-Gui; Cai, Qing-Hua
2009-07-01
To investigate the impacts of large hydropower station in Gufu River on benthic algae, monthly samplings were conducted from September 2004 to June 2007 at the site GF04 which was impacted by the hydropower station, with the site GL03 in Gaolan River as reference. During sampling period, no significant differences were observed in the main physicochemical variables between GF04 and GL03, but the hydrodynamics differed significantly. GL03 was basically at a status of slow flow; while GF04, owing to the discharging from the reservoir, was at a riffle status during more than 60% of the sampling period. Such a difference in hydrodynamics induced significant differences in the community similarity of benthic algae and the relative abundance of unattached diatoms, erect diatoms, and stalked diatoms between GF04 and GL03, which could better reflect the impacts of irregular draw-off by large hydropower station on river eco-system.
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
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...
The calculation interest for administration of hydropower in the long-term
International Nuclear Information System (INIS)
2005-01-01
A review of important findings in newer, economic literature on discount rate in the long term is presented. Based on this review, two questions relating to the administration of Norwegian hydropower resources are briefly discussed. Firstly, which discount rate should be used as basis when valuating the existent Norwegian hydropower plants? Secondly, how should the socio-economic discount rate for investments in hydro projects be determined compared relatively to other types of investments in the power sector? The main conclusion is that the existing rate for administration of hydropower need not be substituted. Neither theory nor empiricism provides a conclusive answer. Certain relevant aspects that may be further investigated are put forth (ml)
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
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 dif- ferent sources, but is incomplete and inconsistent. This lack of information severely hampers the abili- ty to learn from past experiences and creates a bar- rier to the uptake of the technology (Gaul et al., 2010). 14 Journal of Energy... of lack of infor- mation by providing an overview of the status of small hydropower in five southern African countries. Defining small hydropower No internationally agreed definitions exist for the different sizes of hydropower. A generic distinction...
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.
Lucas-Cuevas, Angel Gabriel; Priego Quesada, José Ignacio; Giménez, José Vicente; Aparicio, Inma; Jimenez-Perez, Irene; Pérez-Soriano, Pedro
2016-11-01
Runners tend to shift from a rearfoot to a forefoot strike pattern when running barefoot. However, it is unclear how the first attempts at running barefoot affect habitually rearfoot shod runners. Due to the inconsistency of their recently adopted barefoot technique, a number of new barefoot-related running injuries are emerging among novice barefoot runners. The aim of this study was therefore to analyse the influence of three running conditions (natural barefoot [BF], barefoot with a forced rearfoot strike [BRS], and shod [SH]) on muscle activity and impact accelerations in habitually rearfoot shod runners. Twenty-two participants ran at 60% of their maximal aerobic speed while foot strike, tibial and head impact accelerations, and tibialis anterior (TA), peroneus longus (PL), gastrocnemius medialis (GM) and gastrocnemius lateralis (GL) muscle activity were registered. Only 68% of the runners adopted a non-rearfoot strike pattern during BF. Running BF led to a reduction of TA activity as well as to an increase of GL and GM activity compared to BRS and SH. Furthermore, BRS increased tibial peak acceleration, tibial magnitude and tibial acceleration rate compared to SH and BF. In conclusion, 32% of our runners showed a rearfoot strike pattern at the first attempts at running barefoot, which corresponds to a running style (BRS) that led to increased muscle activation and impact accelerations and thereby to a potentially higher risk of injury compared to running shod.
Videbæk, Solvej; Bueno, Andreas Moeballe; Nielsen, Rasmus Oestergaard; Rasmussen, Sten
2015-07-01
No systematic review has identified the incidence of running-related injuries per 1000 h of running in different types of runners. The purpose of the present review was to systematically search the literature for the incidence of running-related injuries per 1000 h of running in different types of runners, and to include the data in meta-analyses. A search of the PubMed, Scopus, SPORTDiscus, PEDro and Web of Science databases was conducted. Titles, abstracts, and full-text articles were screened by two blinded reviewers to identify prospective cohort studies and randomized controlled trials reporting the incidence of running-related injuries in novice runners, recreational runners, ultra-marathon runners, and track and field athletes. Data were extracted from all studies and comprised for further analysis. An adapted scale was applied to assess the risk of bias. After screening 815 abstracts, 13 original articles were included in the main analysis. Running-related injuries per 1000 h of running ranged from a minimum of 2.5 in a study of long-distance track and field athletes to a maximum of 33.0 in a study of novice runners. The meta-analyses revealed a weighted injury incidence of 17.8 (95% confidence interval [CI] 16.7-19.1) in novice runners and 7.7 (95% CI 6.9-8.7) in recreational runners. Heterogeneity in definitions of injury, definition of type of runner, and outcome measures in the included full-text articles challenged comparison across studies. Novice runners seem to face a significantly greater risk of injury per 1000 h of running than recreational runners.
Estimating the Effects of Climate Change on Federal Hydropower and Power Marketing
Energy Technology Data Exchange (ETDEWEB)
Sale, Michael J [ORNL; Kao, Shih-Chieh [ORNL; Uria Martinez, Rocio [ORNL; Wei, Yaxing [ORNL
2011-01-01
The U.S. Department of Energy is currently preparing an assessment of the effects of climate change on federal hydropower, as directed by Congress in Section 9505 of the Secure Water Act of 2009 (P.L. 111-11). This paper describes the assessment approach being used in a Report to Congress currently being prepared by Oak Ridge National Laboratory. The 9505 assessment will examine climate change effects on water available for hydropower operations and the future power supplies marketed from federal hydropower projects. It will also include recommendations from the Power Marketing Administrations (PMAs) on potential changes in operation or contracting practices that could address these effects and risks of climate change. Potential adaption and mitigation strategies will also be identified. Federal hydropower comprises approximately half of the U.S. hydropower portfolio. The results from the 9505 assessment will promote better understanding among federal dam owners/operators of the sensitivity of their facilities to water availability, and it will provide a basis for planning future actions that will enable adaptation to climate variability and change. The end-users of information are Congressional members, their staff, the PMAs and their customers, federal dam owners/operators, and the DOE Water Power Program.
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.
Modeling Net Land Occupation of Hydropower Reservoirs in Norway for Use in Life Cycle Assessment.
Dorber, Martin; May, Roel; Verones, Francesca
2018-02-20
Increasing hydropower electricity production constitutes a unique opportunity to mitigate climate change impacts. However, hydropower electricity production also impacts aquatic and terrestrial biodiversity through freshwater habitat alteration, water quality degradation, and land use and land use change (LULUC). Today, no operational model exists that covers any of these cause-effect pathways within life cycle assessment (LCA). This paper contributes to the assessment of LULUC impacts of hydropower electricity production in Norway in LCA. We quantified the inundated land area associated with 107 hydropower reservoirs with remote sensing data and related it to yearly electricity production. Therewith, we calculated an average net land occupation of 0.027 m 2 ·yr/kWh of Norwegian storage hydropower plants for the life cycle inventory. Further, we calculated an adjusted average land occupation of 0.007 m 2 ·yr/kWh, accounting for an underestimation of water area in the performed maximum likelihood classification. The calculated land occupation values are the basis to support the development of methods for assessing the land occupation impacts of hydropower on biodiversity in LCA at a damage level.
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...
Energy Technology Data Exchange (ETDEWEB)
Lee, Peter G.; Cheng, Ryan; Scheelar, Catherine [Global Forest Watch Canada (Canada)
2011-11-15
Hydropower is an important source of energy for Canada, accounting for 60% of the electricity generation mix. It is therefore important to understand the environmental performance of such developments in terms of greenhouse gas emissions and environmental impacts. From study of the Eastmain-1 reservoir, it has been extrapolated that hydropower facilities emit between 20 and 36 kilograms of CO2 per megawatt-hour. Hydropower facilities emissions are thus significantly lower than those of fossil fuel facilities, which can emit up to 1,000 kg of CO2 per MW/h. However, hydro projects have several other environmental impacts, such as habitat degradation, bio-accumulation of methyl mercury, and important sediment flow changes. The 271 large hydropower facilities affect 130,000 km of rivers and tens of thousands square kilometres of adjacent habitat. This study pointed out that despite being a low emitter of carbon dioxide, the hydropower sector has significant environmental impacts which require further assessment.
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.
Socio environmental policy and populational resettlement in hydropower plants
International Nuclear Information System (INIS)
Regini Nuti, Mirian; Feitosa Garcia, Marcia
2003-01-01
This paper aims to discuss the resettlement process caused by hydropower plants considering the Brazilian Power Sector ongoing context It is based on the analysis of the hydropower plants that started operation phase in the last tem years There are 17 projects provoking the displacement of 21000 families The paper presents the resettlement modalities used in these projects Finally, the main aspects of the resettlement process in the last decade are focused in order to contribute to the Brazilian Power Sector Resettlement Guidelines improvement and actualization
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
2010-08-19
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 2790-055] Boott Hydropower... Hydropower, Inc. and Eldred L Field Hydroelectric Facility Trust. e. Name of Project: Lowell Hydroelectric... Affairs Coordinator, Boott Hydropower, Inc., One Tech Drive, Suite 220, Andover, MA 01810. Tel: (978) 681...
Small hydropower station in Lavin - Preliminary study
International Nuclear Information System (INIS)
Merz, F.
2008-05-01
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.
The role of hydropower in meeting Turkey's electric energy demand
International Nuclear Information System (INIS)
Yuksek, Omer; Komurcu, Murat Ihsan; Yuksel, Ibrahim; Kaygusuz, Kamil
2006-01-01
The inherent technical, economic and environmental benefits of hydroelectric power, make it an important contributor to the future world energy mix, particularly in the developing countries. These countries, such as Turkey, have a great and ever-intensifying need for power and water supplies and they also have the greatest remaining hydro potential. From the viewpoint of energy sources such as petroleum and natural gas, Turkey is not a rich country; but it has an abundant hydropower potential to be used for generation of electricity and must increase hydropower production in the near future. This paper deals with policies to meet the increasing electricity demand for Turkey. Hydropower and especially small hydropower are emphasized as Turkey's renewable energy sources. The results of two case studies, whose results were not taken into consideration in calculating Turkey's hydro electric potential, are presented. Turkey's small hydro power potential is found to be an important energy source, especially in the Eastern Black Sea Region. The results of a study in which Turkey's long-term demand has been predicted are also presented. According to the results of this paper, Turkey's hydro electric potential can meet 33-46% of its electric energy demand in 2020 and this potential may easily and economically be developed
Excessive exercise habits of runners as new signs of hypertension and arrhythmia.
Kim, Young-Joo; Kim, Chul-Hyun; Park, Kyoung-Min
2016-08-15
Excessive exercise may induce arrhythmia, and this risk is higher in middle-aged people. The study aim was to compare the exercise characteristics of middle-aged runners participating in excessive endurance exercise. The subjects of this study were 552 runners (mean age; 49.0±7.4years) without structural heart disease who performed exercise at least twice per week, had consistently exercised for at least three years, and had finished at least five marathons. The arrhythmia runner group (ARG, n=14) and normal runner group (NRG, n=538) were compared with regard to hemodynamic response, cardiorespiratory fitness level, training history, number of finished races, finishing times, and exercise habits. The mean resting systolic (134.0±15.8mmHg) and diastolic (85.8±10.9mmHg) blood pressure values indicated pre-hypertension, while the mean maximal SBP (213.7±27.4mmHg) values indicated exercise-induced hypertension. The VO2max was significantly higher and the maximal DBP was significantly lower in the ARG than in the NRG (phypertension and exercise-induced hypertension, and the ARG had higher VO2max values, greater exercise intensities, and longer training histories than the NRG. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Predisposing Risk Factors and Stress Fractures in Division I Cross Country Runners.
Giffin, Kaci L; Knight, Kathy B; Bass, Martha A; Valliant, Melinda W
2017-11-11
The purpose of this study was to explore factors associated with increased stress fractures in collegiate cross country runners. Participants in this study were 42 male and female cross country runners at a Division I university. Each athlete completed a questionnaire regarding smoking status, vitamin/mineral intake, previous stress fracture history, birth control usage, menstrual status, and demographic information. Nutritional assessment via a 3-day food record and measurements of whole body, lumbar spine, and hip bone mineral densities (BMD) were also conducted on each athlete. Results indicated that 40% of the female and 35% of the male runners reported a history of stress fracture, and that all of these did not meet the recommended daily energy intake or adequate intakes for calcium or Vitamin D required for their amount of training. Two-tailed t-test found statistically higher incidences of lumbar spine BMD in males and females whose daily calcium and Vitamin D intakes were below minimum requirements as well as for women whose caloric intake was below the required level. When data on the lumbar spine was evaluated, 31% of participants (31.8% of the male and 30% of the female runners) were identified as having osteopenia and 4.8% with osteoporosis. Results warrant a need for future longitudinal studies.
Serum lipid levels and steroidal hormones in women runners with irregular menses.
Thompson, D L; Snead, D B; Seip, R L; Weltman, J Y; Rogol, A D; Weltman, A
1997-02-01
This study compared the lipid profile of women runners with menstrual cycle irregularities with their normally menstruating counterparts. Relationships among selected steroid hormones and serum lipid levels in 10 eumenorrheic (EU) and 8 oligo-/amenorrheic (O/A) women runners and 6 eumenorrheic controls (CON) were examined. Serum 17 beta-estradiol (E2), progesterone (Prog), and dehydroepiandrosterone-sulfate (DHEAS) concentrations were determined in daily blood samples for 21 days, and integrated concentrations were calculated. Fasting blood samples were analyzed for total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), HDL2, HDL3, triglycerides (Trig), and apolipoproteins A-1, A-II, and B. The O/A group had significantly lower E2 and Prog than EU or CON groups. Women in the CON group had lower HDL-C and HDL3 than the runners. With all women grouped together, E2 was not significantly correlated with any measured blood lipid parameters. On the other hand, DHEAS was significantly correlated with HDL-C, HDL2, and apolipoprotein A-I. These data demonstrate that women runners, regardless of menstrual cycle status, exhibit higher HDL-C concentrations than CON and supports previous research reporting a positive association between DHEAS and HDL-C.
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.
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.
Hydropower | Climate Neutral Research Campuses | NREL
project. Options usually include self-financing, issuing bonds, or obtaining third-party financing from how hydropower may fit into your climate action plans. Campus Options Considerations Sample Project to handle permitting issues? Does your campus need a hydraulics laboratory? Is financing available
2013-10-08
... Hydropower Company, LLC; Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments, Motions To Intervene, and Competing Applications On August 20, 2013, the New England Hydropower Company... river are owned by the city of Meriden. Applicant Contact: Mr. Michael C. Kerr, New England Hydropower...
2013-11-05
... City, UT; Notice of Preliminary Determination of a Qualifying Conduit Hydropower Facility and... Grove City, Utah (Pleasant Grove) filed a notice of intent to construct a qualifying conduit hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the Hydropower...
2010-02-19
... List for Hydropower Licensing Study Dispute Resolution; Notice Extending Filing Date for Applications for Panel Member List for Hydropower Licensing Study Dispute Resolution February 4, 2010. On October... on a list of resource experts willing to serve as a third panel member in the Commission's hydropower...
2013-08-30
... Sandpoint, Idaho; Notice of Preliminary Determination of a Qualifying Conduit Hydropower Facility and... intent to construct a qualifying conduit hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the Hydropower Regulatory Efficiency Act of 2013 (HREA). The Little...
2013-10-09
..., Oregon; Notice of Preliminary Determination of a Qualifying Conduit Hydropower Facility and Soliciting... of intent to construct a qualifying conduit hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the Hydropower Regulatory Efficiency Act of 2013 (HREA). The...
Directory of Open Access Journals (Sweden)
Zbigniew Jastrzębski
2016-10-01
Full Text Available Objectives: The objective of the study was to reveal morphology, electrolyte and chosen biochemical parameters in terms of health risk in runners in reference to their age and running speed in the case of running a distance of 100 km, which occur after 12 h or 24 h of recovery. Material and Methods: Fourteen experienced, male, amateur, ultra-marathon runners, divided into two age and two speed groups took part in the 100-km run. Blood samples for analyses indexes were collected from the ulnar vein just before the run, after 25 km, 50 km, 75 km and 100 km, as well as 12 h and 24 h after termination of the run. Results: The sustained ultramarathon run along with the distance covered (p < 0.05 caused an increase in myoglobin (max 90-fold, bilirubin (max 2.8-fold and total antioxidant status (max 1.15-fold, which also continued during the recovery. Significant changes in the number of white blood cells were observed with each sequential course and could be associated with muscle damage. The electrolyte showed changes towards slight hyperkalemia, but no changes in natrium and calcium concentrations. There were no significant differences between the age and speed groups for all the parameters after completing the 100-km run as well as after 12 h and 24 h of recovery. Conclusions: Considering changes in blood morphology and chosen biochemical parameters in ultra-marathon runners during a 100-km run it can be stated that such an exhausting effort may be dangerous for human health due to metabolic changes and large damage to the organs. Negative metabolic changes are independent of age of an ultramarathon runner and occur both in younger (32±5.33 years and older participants (50.56±9.7 years. It can be concluded that organ damage and negative metabolic changes during a 100-km run occur similarly in participants less experienced as well as in well trained runners. Int J Occup Med Environ Health 2016;29(5:801–814
Conway, Declan; Dalin, Carole; Landman, Willem A.; Osborn, Timothy J.
2017-12-01
Hydropower comprises a significant and rapidly expanding proportion of electricity production in eastern and southern Africa. In both regions, hydropower is exposed to high levels of climate variability and regional climate linkages are strong, yet an understanding of spatial interdependences is lacking. Here we consider river basin configuration and define regions of coherent rainfall variability using cluster analysis to illustrate exposure to the risk of hydropower supply disruption of current (2015) and planned (2030) hydropower sites. Assuming completion of the dams planned, hydropower will become increasingly concentrated in the Nile (from 62% to 82% of total regional capacity) and Zambezi (from 73% to 85%) basins. By 2030, 70% and 59% of total hydropower capacity will be located in one cluster of rainfall variability in eastern and southern Africa, respectively, increasing the risk of concurrent climate-related electricity supply disruption in each region. Linking of nascent regional electricity sharing mechanisms could mitigate intraregional risk, although these mechanisms face considerable political and infrastructural challenges.
A review of Environmental Impact Assessment parameters required for set up of a hydropower project
International Nuclear Information System (INIS)
Roy, Pankaj Kumar; Mazumdar, Asis
2013-01-01
Environmental Impact Assessment in general, hydro-meteorological conditions, topography, hydrology, water availability analysis of a river system, importance of hydropower and feasibility study of Environmental Impact assessment due to the construction of the hydropower plant have been discussed in this research work. The site selection is one of the major components so far the hydropower is concerned and also the minimum flow should have known to us so that the capacity of a hydropower plant can be predicted. The sustainable flow, which refers the flow is available throughout the year, has been calculated based on flow duration curve. This study highlights the environmental impact assessment particularly related to hydropower project. Here the study area a district town located in the eastern region of India on the banks of river Kosi has been considered. The historical rainfall and the river discharge data have been collected from various organizations. The stage-discharge correlation and hydrological parameters related to hydropower have been analyzed and also to discuss the review of environmental impact assessment in hydropower project. The EIA analysis can be also carried out by using fuzzy logic wherein the EIA parameters can be given different weight-age based on the various survey reports that have been carried out at different places at different time. Such analysis has also been provided below based on the various data obtained.
Transient myocardial tissue and function changes during a marathon in less fit marathon runners.
Gaudreault, Valerie; Tizon-Marcos, Helena; Poirier, Paul; Pibarot, Philippe; Gilbert, Philippe; Amyot, Marc; Rodés-Cabau, Josep; Després, Jean-Pierre; Bertrand, Olivier; Larose, Eric
2013-10-01
Although regular physical activity improves health, strenuous exercise might transiently increase cardiac risk. Training and fitness might provide protection. We prospectively studied 20 recreational marathon runners without known cardiovascular disease or symptoms: at peak training before, immediately after, and 3 months after a 42.2-km marathon. Changes in global/segmental myocardial function, edema, resting perfusion, and fibrosis were measured. At peak training, runners exercised 8.1 ± 2.3 hours and 62 ± 18 km per week with mean maximal oxygen consumption (VO2max) of 53.2 ± 8.3 mL/kg/min. In response to the marathon, global left ventricular and right ventricular ejection fraction decreased in half of the runners; these runners had poorer peak training distance, training time, and fitness level. Change in global left ventricular ejection fraction was associated with VO2max. Overall, 36% of segments developed edema, 53% decreased function, and 59% decreased perfusion. Significant agreement was observed between segment decreasing function, decreasing perfusion, and developing edema. Myocardial changes were reversible at 3 months. Completing a marathon leads to localized myocardial edema, diminished perfusion, and decreased function occurring more extensively in less trained and fit runners. Although reversible, these changes might contribute to the transient increase in cardiac risk reported during sustained vigorous exercise. Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
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
A multi-scale spatial approach to address environmental effects of small hydropower development.
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.
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.
Water, energy and agricultural landuse trends at Shiroro hydropower station and environs
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.
Socio-environmental integration of hydropower facilities
International Nuclear Information System (INIS)
Harby, Atle; Forseth, Torbjoern; Ruud, Audun; Bakken, Tor Haakon
2017-01-01
Centre for Environmental Design of Renewable Energy (CEDREN) is a research centre focusing on hydropower production and environmental impacts of hydropower. The main objective of CEDREN is to develop and communicate design solutions for renewable energy production that address environmental and societal challenges at local, regional, national and global levels. Environmental design means that planning, building and operation have to include technical, economic, environmental and socio-political aspects throughout the whole life-span of the project. Methods and tools to ensure environmental design are developed in CEDREN and applied to case studies in Norway and internationally. These methods and tools focus on finding physical and biological bottlenecks for affected species and ecosystems by mapping, modelling and analysis of both physical conditions and ecological status. CEDREN proposes different measures, tools and methods to improve the environmental conditions as well as how to maintain or increase the power production. In addition, a strong focus must be made on political governance to ensure more representative participation of relevant stakeholders in the process of finding the best technical, economic and political solutions for power production, the environment and the society. Key research findings used to develop relationships between physical factors like flow, flow fluctuations, water temperature, water velocity, water depth and water-covered area and biological response will be shown. Examples of improved methods for better planning procedures with stakeholder engagement will be proposed. Examples of methods and tools for environmental design of hydropower will be given for several regulated rivers in Norway and abroad. (authors)
2013-09-16
..., Vermont; Notice of Preliminary Determination of a Qualifying Conduit Hydropower Facility and Soliciting... construct a qualifying conduit hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the Hydropower Regulatory Efficiency Act of 2013 (HREA). The Nelson Street 17 kW...
2011-02-11
... Hydropower, LLC; Notice of Scoping Meetings and Environmental Site Review and Soliciting Scoping Comments.... c. Date filed: July 12, 2010. d. Applicant: Great River Hydropower, LLC. e. Name of Project: Upper... 796-foot-long by 46-foot-wide by 25-foot-high concrete hydropower structure consisting of 30 turbine...
2010-03-05
... Hydropower, LLC; Notice of Application Accepted for Filing and Soliciting Motions To Intervene and Protests... No.: P-12783-003. c. Date filed: July 22, 2009. d. Applicant: Inglis Hydropower, LLC. e. Name of Project: Inglis Hydropower Project. f. Location: The proposed project would be located at the existing...
Relationship between Achilles tendon properties and foot strike patterns in long-distance runners.
Kubo, Keitaro; Miyazaki, Daisuke; Tanaka, Shigeharu; Shimoju, Shozo; Tsunoda, Naoya
2015-01-01
The purpose of this study was to investigate the relationship between Achilles tendon properties and foot strike patterns in long-distance runners. Forty-one highly trained male long-distance runners participated in this study. Elongation of the Achilles tendon and aponeurosis of the medial gastrocnemius muscle were measured using ultrasonography, while the participants performed ramp isometric plantar flexion up to the voluntary maximum. The relationship between the estimated muscle force and tendon elongation during the ascending phase was fit to a linear regression, the slope of which was defined as stiffness. In addition, the cross-sectional area of the Achilles tendon was measured using ultrasonography. Foot strike patterns (forefoot, midfoot and rearfoot) during running were determined at submaximal velocity (18 km · h(-1)) on a treadmill. The number of each foot strike runner was 12 for the forefoot (29.3%), 12 for the midfoot (29.3%) and 17 for the rearfoot (41.5%). No significant differences were observed in the variables measured for the Achilles tendon among the three groups. These results suggested that the foot strike pattern during running did not affect the morphological or mechanical properties of the Achilles tendon in long-distance runners.
Estimated cumulative sediment trapping in future hydropower reservoirs in Africa
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
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.
DOE Hydropower Program biennial report 1994--1995 with an updated annotated bibliography
International Nuclear Information System (INIS)
Rinehart, B.N.; Francfort, J.E.; Sommers, G.L.; Cada, G.F.; Sale, M.J.
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
Santos-Concejero, J; Granados, C; Irazusta, J; Bidaurrazaga-Letona, I; Zabala-Lili, J; Tam, N; Gil, S M
2013-09-01
The purpose of this study was to investigate the relationship between biomechanical variables and running economy in North African and European runners. Eight North African and 13 European male runners of the same athletic level ran 4-minute stages on a treadmill at varying set velocities. During the test, biomechanical variables such as ground contact time, swing time, stride length, stride frequency, stride angle and the different sub-phases of ground contact were recorded using an optical measurement system. Additionally, oxygen uptake was measured to calculate running economy. The European runners were more economical than the North African runners at 19.5 km · h(-1), presented lower ground contact time at 18 km · h(-1) and 19.5 km · h(-1) and experienced later propulsion sub-phase at 10.5 km · h(-1),12 km · h(-1), 15 km · h(-1), 16.5 km · h(-1) and 19.5 km · h(-1) than the European runners (P Running economy at 19.5 km · h(-1) was negatively correlated with swing time (r = -0.53) and stride angle (r = -0.52), whereas it was positively correlated with ground contact time (r = 0.53). Within the constraints of extrapolating these findings, the less efficient running economy in North African runners may imply that their outstanding performance at international athletic events appears not to be linked to running efficiency. Further, the differences in metabolic demand seem to be associated with differing biomechanical characteristics during ground contact, including longer contact times.
2013-10-16
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. AD13-9-000] Hydropower... recommendations on the feasibility of a two-year process for the issuance of a license for hydropower development... Hydropower Regulatory Efficiency Act of 2013. The workshop will be held in the Commission Meeting Room at 888...
78 FR 79433 - Mahoning Hydropower, LLC, Ohio, Notice of Availability of Environmental Assessment
2013-12-30
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13953-002] Mahoning Hydropower, LLC, Ohio, Notice of Availability of Environmental Assessment In accordance with the National... Hydropower, LLC's application for a license to construct, operate, and maintain the Lake Milton Hydroelectric...
Determining the effect of key climate drivers on global hydropower production
Galelli, S.; Ng, J. Y.; Lee, D.; Block, P. J.
2017-12-01
Accounting for about 17% of total global electrical power production, hydropower is arguably the world's main renewable energy source and a key asset to meet Paris climate agreements. A key component of hydropower production is water availability, which depends on both precipitation and multiple drivers of climate variability acting at different spatial and temporal scales. To understand how these drivers impact global hydropower production, we study the relation between four patterns of ocean-atmosphere climate variability (i.e., El Niño Southern Oscillation, Pacific Decadal Oscillation, North Atlantic Oscillation, and Atlantic Multidecadal Oscillation) and monthly time series of electrical power production for over 1,500 hydropower reservoirs—obtained via simulation with a high-fidelity dam model forced with 20th century climate conditions. Notably significant relationships between electrical power productions and climate variability are found in many climate sensitive regions globally, including North and South America, East Asia, West Africa, and Europe. Coupled interactions from multiple, simultaneous climate drivers are also evaluated. Finally, we highlight the importance of using these climate drivers as an additional source of information within reservoir operating rules where the skillful predictability of inflow exists.
Shorter Ground Contact Time and Better Running Economy: Evidence From Female Kenyan Runners.
Mooses, Martin; Haile, Diresibachew W; Ojiambo, Robert; Sang, Meshack; Mooses, Kerli; Lane, Amy R; Hackney, Anthony C
2018-06-25
Mooses, M, Haile, DW, Ojiambo, R, Sang, M, Mooses, K, Lane, AR, and Hackney, AC. Shorter ground contact time and better running economy: evidence from female Kenyan runners. J Strength Cond Res XX(X): 000-000, 2018-Previously, it has been concluded that the improvement in running economy (RE) might be considered as a key to the continued improvement in performance when no further increase in V[Combining Dot Above]O2max is observed. To date, RE has been extensively studied among male East African distance runners. By contrast, there is a paucity of data on the RE of female East African runners. A total of 10 female Kenyan runners performed 3 × 1,600-m steady-state run trials on a flat outdoor clay track (400-m lap) at the intensities that corresponded to their everyday training intensities for easy, moderate, and fast running. Running economy together with gait characteristics was determined. Participants showed moderate to very good RE at the first (202 ± 26 ml·kg·km) and second (188 ± 12 ml·kg·km) run trials, respectively. Correlation analysis revealed significant relationship between ground contact time (GCT) and RE at the second run (r = 0.782; p = 0.022), which represented the intensity of anaerobic threshold. This study is the first to report the RE and gait characteristics of East African female athletes measured under everyday training settings. We provided the evidence that GCT is associated with the superior RE of the female Kenyan runners.
Frequency Stability of Hierarchically Controlled Hybrid Photovoltaic-Battery-Hydropower Microgrids
DEFF Research Database (Denmark)
Guan, Yajuan; Vasquez, Juan Carlos; Guerrero, Josep M.
2014-01-01
Hybrid photovolvaic battery-hydropower microgrids can increase electricity accessibility and availability in remote areas. In those microgrids with grid-connected and islanded modes capabilities, seamless transition between both modes is needed as well. However, the different resources with conve......Hybrid photovolvaic battery-hydropower microgrids can increase electricity accessibility and availability in remote areas. In those microgrids with grid-connected and islanded modes capabilities, seamless transition between both modes is needed as well. However, the different resources...
Risk factors for lower extremity injuries among male marathon runners.
Van Middelkoop, M; Kolkman, J; Van Ochten, J; Bierma-Zeinstra, S M A; Koes, B W
2008-12-01
The aim of this study is to identify risk factors for lower extremity injuries in male marathon runners. A random sample of 1500 recreational male marathon runners was drawn. Possible risk factors were obtained from a baseline questionnaire 1 month before the start of the marathon. Information on injuries sustained shortly before or during the marathon was obtained using a post-race questionnaire. Of the 694 male runners who responded to the baseline and post-race questionnaire, 28% suffered a self-reported running injury on the lower extremities in the month before or during the marathon run. More than six times race participation in the previous 12 months [odds ratio (OR) 1.66; confidence interval (CI) 1.08-2.56], a history of running injuries (OR 2.62; CI 1.82-3.78), high education level (OR 0.73; CI 0.51-1.04) and daily smoking (OR 0.23; CI 0.05-1.01) were associated with the occurrence of lower extremity injuries. Among the modifiable risk factor studies, a training distance training is a strong protective factor for knee injuries. Other training characteristics appear to have little or no effect on future injuries.
Peng, Guoyi; Cao, Shuliang; Ishizuka, Masaru; Hayama, Shinji
2002-06-01
This paper is concerned with the design optimization of axial flow hydraulic turbine runner blade geometry. In order to obtain a better design plan with good performance, a new comprehensive performance optimization procedure has been presented by combining a multi-variable multi-objective constrained optimization model with a Q3D inverse computation and a performance prediction procedure. With careful analysis of the inverse design of axial hydraulic turbine runner, the total hydraulic loss and the cavitation coefficient are taken as optimization objectives and a comprehensive objective function is defined using the weight factors. Parameters of a newly proposed blade bound circulation distribution function and parameters describing positions of blade leading and training edges in the meridional flow passage are taken as optimization variables.The optimization procedure has been applied to the design optimization of a Kaplan runner with specific speed of 440 kW. Numerical results show that the performance of designed runner is successfully improved through optimization computation. The optimization model is found to be validated and it has the feature of good convergence. With the multi-objective optimization model, it is possible to control the performance of designed runner by adjusting the value of weight factors defining the comprehensive objective function. Copyright
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
Oxygen consumption of elite distance runners on an anti-gravity treadmill®.
McNeill, David K P; Kline, John R; de Heer, Hendrick D; Coast, J Richard
2015-06-01
Lower body positive pressure (LBPP), or 'anti-gravity' treadmills® have become increasingly popular among elite distance runners. However, to date, few studies have assessed the effect of body weight support (BWS) on the metabolic cost of running among elite runners. This study evaluated how BWS influenced the relationship between velocity and metabolic cost among 6 elite male distance runners. Participants ran three- 16 minute tests consisting of 4 stages of 4 minutes at 8, 7, 6 and 5 min·mile(-1) pace (3.35, 3.84, 4.47 and 5.36 m·s(-1)), while maintaining an aerobic effort (Respiratory Exchange Ratio ≤1.00). One test was run on a regular treadmill, one on an anti-gravity treadmill with 40% BWS and one with 20% BWS being provided. Expired gas data were collected and regression equations used to determine and compare slopes. Significant decreases in oxygen uptake (V̇O2) were found with each increase in BWS (p rate, perceived exertion or directly measured oxygen uptake) should be used to guide training intensity when training on the LBPP treadmill. Key pointsWith increasing amounts of body weight-support (BWS), the slope of the relationship between velocity and oxygen consumption (ΔVO2/Δv) decreases significantly. This means the change in oxygen consumption (VO2) is significantly smaller over a given change in velocity at higher amounts of BWS.There is a non-linear decrease in VO2 with increasing BWS. As such, with each increment in the amount of BWS provided, the reduction in VO2 becomes increasingly smaller.This paper provides first of its kind data on the effects of BWS on the cost of running among highly trained, elite runners. The outcomes of this study are in line with previous findings among non-elite runners.
Establishment and evaluation of operation function model for cascade hydropower station
Chang-ming Ji; Ting Zhou; Hai-tao Huang
2010-01-01
Toward solving the actual operation problems of cascade hydropower stations under hydrologic uncertainty, this paper presents the process of extraction of statistical characteristics from long-term optimal cascade operation, and proposes a monthly operation function algorithm for the actual operation of cascade hydropower stations through the identification, processing, and screening of available information during long-term optimal operation. Applying the operation function to the cascade hy...
Treatise on water hammer in hydropower standards and guidelines
International Nuclear Information System (INIS)
Bergant, A; Mazij, J; Karney, B; Pejović, S
2014-01-01
This paper reviews critical water hammer parameters as they are presented in official hydropower standards and guidelines. A particular emphasize is given to a number of IEC standards and guidelines that are used worldwide. The paper critically assesses water hammer control strategies including operational scenarios (closing and opening laws), surge control devices (surge tank, pressure regulating valve, flywheel, etc.), redesign of the water conveyance system components (tunnel, penstock), or limitation of operating conditions (limited operating range) that are variably covered in standards and guidelines. Little information is given on industrial water hammer models and solutions elsewhere. These are briefly introduced and discussed in the light of capability (simple versus complex systems), availability of expertise (in house and/or commercial) and uncertainty. The paper concludes with an interesting water hammer case study referencing the rules and recommendations from existing hydropower standards and guidelines in a view of effective water hammer control. Recommendations are given for further work on development of a special guideline on water hammer (hydraulic transients) in hydropower plants
Treatise on water hammer in hydropower standards and guidelines
Bergant, A.; Karney, B.; Pejović, S.; Mazij, J.
2014-03-01
This paper reviews critical water hammer parameters as they are presented in official hydropower standards and guidelines. A particular emphasize is given to a number of IEC standards and guidelines that are used worldwide. The paper critically assesses water hammer control strategies including operational scenarios (closing and opening laws), surge control devices (surge tank, pressure regulating valve, flywheel, etc.), redesign of the water conveyance system components (tunnel, penstock), or limitation of operating conditions (limited operating range) that are variably covered in standards and guidelines. Little information is given on industrial water hammer models and solutions elsewhere. These are briefly introduced and discussed in the light of capability (simple versus complex systems), availability of expertise (in house and/or commercial) and uncertainty. The paper concludes with an interesting water hammer case study referencing the rules and recommendations from existing hydropower standards and guidelines in a view of effective water hammer control. Recommendations are given for further work on development of a special guideline on water hammer (hydraulic transients) in hydropower plants.
Wirnitzer, Katharina; Seyfart, Tom; Leitzmann, Claus; Keller, Markus; Wirnitzer, Gerold; Lechleitner, Christoph; Rüst, Christoph Alexander; Rosemann, Thomas; Knechtle, Beat
2016-01-01
Beneficial and detrimental effects of various vegetarian and vegan diets on the health status are well known. Considering the growing background numbers of vegetarians and vegans, the number of vegetarian and vegan runners is likely to rise, too. Therefore, the Nutrition and Running High Mileage (NURMI) Study was designed as a comparative study to investigate the prevalence of omnivores, vegetarians, and vegans in running events and to detect potential differences in running performance comparing these three subgroups. The NURMI Study will be conducted in three steps following a cross-sectional design. Step 1 will determine epidemiological aspects of endurance runners (any distance) using a short standardized questionnaire. Step 2 will investigate dietary habits and running history from eligible participants (capable of running a half-marathon at least) using an extended standardized questionnaire. Step 3 will collect data after a running event on finishing time and final ranking as well as a post-race rating of perceived exertion, mood status, nutrient and fluid intake during the race. Our study will provide a major contribution to overcome the lack of data on the prevalence and running performance of vegetarian and vegan runners in endurance running events. We estimate the prevalence of vegetarians and vegans participating in a running event to be less compared to the respective proportion of vegetarians and vegans to the general population. Furthermore we will validate the subject's self-assessment of their respective diet. This comparative study may identify possible effects of dietary behavior on running performance und may detect possible differences between the respective subgroups: omnivorous, vegetarian and vegan runners. Trial registration Current controlled trials, ISRCTN73074080.
World Small Hydropower Development Report 2013 - Zimbabwe
CSIR Research Space (South Africa)
Jonker Klunne, W
2013-01-01
Full Text Available in 2006. With the current economic and political situation in Zimbabwe improving, the drive by the Government to encourage independent power producers, the prospects for the development of small hydropower are promising....
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.
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.
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.
Directory of Open Access Journals (Sweden)
M. J. Laye
2015-01-01
Full Text Available High levels of cardiovascular fitness (CRF and physical activity (PA are associated with decreased mortality and risk to develop metabolic diseases. The independent contributions of CRF and PA to metabolic disease risk factors are unknown. We tested the hypothesis that runners who run consistently >50 km/wk and/or >2 marathons/yr for the last 5 years have superior metabolic fitness compared to matched sedentary subjects (CRF, age, gender, and BMI. Case-control recruitment of 31 pairs of runner-sedentary subjects identified 10 matched pairs with similar VO2max (mL/min/kg (similar-VO2max. The similar-VO2max group was compared with a group of age, gender, and BMI matched pairs who had the largest difference in VO2max (different-VO2max. Primary outcomes that defined metabolic fitness including insulin response to an oral glucose tolerance test, fasting lipids, and fasting insulin were superior in runners versus sedentary controls despite similar VO2max. Furthermore, performance (velocity at VO2max, running economy, improved exercise metabolism (lactate threshold, and skeletal muscle levels of mitochondrial proteins were superior in runners versus sedentary controls with similar VO2max. In conclusion subjects with a high amount of PA have more positive metabolic health parameters independent of CRF. PA is thus a good marker against metabolic diseases.
2011-03-25
.... APHIS-2010-0101] RIN 0579-AD39 Importation of French Beans and Runner Beans From the Republic of Kenya... French beans and runner beans from the Republic of Kenya into the United States. As a condition of entry... French beans and runner beans from the Republic of Kenya into the United States while continuing to...
Life cycle greenhouse gas emissions estimation for small hydropower schemes in India
International Nuclear Information System (INIS)
Varun; Prakash, Ravi; Bhat, I.K.
2012-01-01
This paper presents for the first time correlations for greenhouse gas (GHG) emissions from small hydropower schemes in India. In this paper an attempt has been made to develop life cycle GHG emissions correlations for three different types of small hydropower schemes (run-of river, canal based and dam-toe) in India. It has been found out that GHG emissions depend on the head and capacity of the small hydropower project. The results obtained from correlations show good agreement with the estimated results using EIO-LCA (Economic Input–Output-Life Cycle Assessment) technique. These correlations may be useful for the development of new small hydropower (SHP) schemes, as they can be used to predict life cycle GHG emissions based on capacity, head and type of SHP schemes. -- Highlights: ► A study has been carried out for the Life Cycle Greenhouse gas emissions estimation for SHP schemes in India. ► Around 145 SHP schemes have been studied and their GHG emissions have been estimated. ► Based upon these results correlations have been developed for three different types of SHP schemes.
Basin-scale impacts of hydropower development on the Mompós Depression wetlands, Colombia
Angarita, Héctor; Wickel, Albertus J.; Sieber, Jack; Chavarro, John; Maldonado-Ocampo, Javier A.; Herrera-R., Guido A.; Delgado, Juliana; Purkey, David
2018-05-01
A number of large hydropower dams are currently under development or in an advanced stage of planning in the Magdalena River basin, Colombia, spelling uncertainty for the Mompós Depression wetlands, one of the largest wetland systems in South America at 3400 km2. Annual large-scale inundation of floodplains and their associated wetlands regulates water, nutrient, and sediment cycles, which in turn sustain a wealth of ecological processes and ecosystem services, including critical food supplies. In this study, we implemented an integrated approach focused on key attributes of ecologically functional floodplains: (1) hydrologic connectivity between the river and the floodplain, and between upstream and downstream sections; (2) hydrologic variability patterns and their links to local and regional processes; and (3) the spatial scale required to sustain floodplain-associated processes and benefits, like migratory fish biodiversity. The implemented framework provides an explicit quantification of the nonlinear or direct response relationship of those considerations with hydropower development. The proposed framework was used to develop a comparative analysis of the potential effects of the hydropower expansion necessary to meet projected 2050 electricity requirements. As part of this study, we developed an enhancement of the Water Evaluation and Planning system (WEAP) that allows resolution of the floodplains water balance at a medium scale (˜ 1000 to 10 000 km2) and evaluation of the potential impacts of upstream water management practices. In the case of the Mompós Depression wetlands, our results indicate that the potential additional impacts of new hydropower infrastructure with respect to baseline conditions can range up to one order of magnitude between scenarios that are comparable in terms of energy capacity. Fragmentation of connectivity corridors between lowland floodplains and upstream spawning habitats and reduction of sediment loads show the greatest
Mini-hydropower development in human province of China and its position in the national economy
International Nuclear Information System (INIS)
Daogao, L.
1991-01-01
Hunan province is situated in the southern part of the middle reaches of Yangtze River. With a population of 61 million, it covers an area of about 211,800 km 2 , equivalent to forty percents of the territorial area of France. Throughout the province, there are more than 5300 rivers and 13000 reservoirs completed before 1991, of which over 7300 mini-hydropower stations are under operation. The theoretical hydropower potential is 15320 MW among them 12990 MW can be exploited with a total installed capacity of 1320 MW and an annual generation output of 4150 GWh. The paper will describe the general condition of the hydropower resources, development of mini-hydropower in Human province and its positive role in the national economy. Additionally, the standard of classification, the type of equipment for the medium and small-sized hydropower plants and market conditions in Hunan will be also involved in the paper. 5 tabs
The Effect of Clinical Pilates on Functional Movement in Recreational Runners.
Laws, Anna; Williams, Sean; Wilson, Cassie
2017-09-01
Biomechanical imbalances and inefficient functional movements are considered contributing factors to running-related injuries. Clinical Pilates uses a series of exercises focused on retraining normal movement patterns. This study investigated whether a 6-week course of Clinical Pilates improves functional movement and thereby, potentially, reduces the risk of running-related injuries associated with movement dysfunction. A modified functional movement screen was used to analyze the functional movement ability of forty runners. Forty participants completed a 6-week course of Clinical Pilates delivered by a Clinical Pilates instructor. The movement screen was carried out 3 times for each runner: 6 weeks pre-intervention (baseline), within one week pre-intervention (pre) and within one week post-intervention (post). Repeated-measures analysis of variance and post-hoc tests found significant increases in scores between baseline and post (mean±SD; 13.4±2.4 vs. 17.0±1.7, pPilates significantly improves functional movement in recreational runners, and this may lead to a reduction in the risk of running-related injuries. © Georg Thieme Verlag KG Stuttgart · New York.
Dataset for case studies of hydropower unit commitment
Directory of Open Access Journals (Sweden)
Jinwen Wang
2018-06-01
Full Text Available This paper presents the data all needed for nine case studies of hydropower unit commitment, which determines the optimal operating zones and generating discharges of units after the quarter-hourly releases and water heads are derived by the operation of cascaded hydropower reservoirs. The power output function and feasible operating zones of units are provided, and optimization solvers are used to acquire the results in detail for the case studies, including the quarter-hourly generating discharges, power generations, as well as operating zones of individual units. Performance indices, including the spillage, energy production, and the low-efficiency generating rate, are summarized for all case studies and can be readily used for comparison between algorithms in future.
Energy Technology Data Exchange (ETDEWEB)
None
1979-02-01
In August 1978, the United States Department of Energy and the Turlock Irrigation District entered into a cooperative agreement for a Joint District's Low-Head Hydropower Assessment Study. The purpose of the agreement was to carry out a study of the hydropower potential at sites within the borders of the Turlock, Merced, South San Joaquin, and Oakdale Irrigation Districts in California. The required data were gathered and analyzed. The results of this study indicate the total potential small hydropower capacity with the Joint Districts is 19,560 kW installed with an annual energy generation of 68,561,800 kWh. This is equivalent to oil-savings of 118,616 barrels per y.
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.)
Increased Circulating Anti-inflammatory Cells in Marathon-trained Runners.
Rehm, K; Sunesara, I; Marshall, G D
2015-10-01
Exercise training can alter immune function. Marathon training has been associated with an increased susceptibility to infectious diseases and an increased activity of inflammatory-based diseases, but the precise mechanisms are unknown. The purpose of this study was to compare levels of circulating CD4+ T cell subsets in the periphery of marathon-trained runners and matched non-marathon controls. 19 recreational marathoners that were 4 weeks from running a marathon and 19 demographically-matched healthy control subjects had the percentage of CD4+ T cell subpopulations (T helper 1, T helper 2, T helper 1/T helper 2 ratio, regulatory T cells, CD4+ IL10+, and CD4+ TGFβ+ (Transforming Growth Factor-beta) measured by flow cytometry. Marathon-trained runners had significantly less T helper 1 and regulatory T cells and significantly more T helper 2, CD4+ IL10+, and TGFβ+ cells than the control subjects. The alterations in the percentage of T helper 1 and T helper 2 cells led to a significantly lower T helper 1/T helper 2 ratio in the marathon-trained runners. These data suggest that endurance-based training can increase the number of anti-inflammatory cells. This may be a potential mechanism for the increased incidence of both infectious and inflammatory diseases observed in endurance athletes. © Georg Thieme Verlag KG Stuttgart · New York.
Parshad, Rana D; McGregor, Stephen J; Busa, Michael A; Skufca, Joseph D; Bollt, Erik
2012-01-01
Control entropy (CE) is a complexity analysis suitable for dynamic, non-stationary conditions which allows the inference of the control effort of a dynamical system generating the signal. These characteristics make CE a highly relevant time varying quantity relevant to the dynamic physiological responses associated with running. Using High Resolution Accelerometry (HRA) signals we evaluate here constraints of running gait, from two different groups of runners, highly trained collegiate and untrained runners. To this end,we further develop the control entropy (CE) statistic to allow for group analysis to examine the non-linear characteristics of movement patterns in highly trained runners with those of untrained runners, to gain insight regarding gaits that are optimal for running. Specifically, CE develops response time series of individuals descriptive of the control effort; a group analysis of these shapes developed here uses Karhunen Loeve Analysis (KL) modes of these time series which are compared between groups by application of a Hotelling T² test to these group response shapes. We find that differences in the shape of the CE response exist within groups, between axes for untrained runners (vertical vs anterior-posterior and mediolateral vs anterior-posterior) and trained runners (mediolateral vs anterior-posterior). Also shape differences exist between groups by axes (vertical vs mediolateral). Further, the CE, as a whole, was higher in each axis in trained vs untrained runners. These results indicate that the approach can provide unique insight regarding the differing constraints on running gait in highly trained and untrained runners when running under dynamic conditions. Further, the final point indicates trained runners are less constrained than untrained runners across all running speeds.
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.
Geothermal and hydropower production in Iceland
International Nuclear Information System (INIS)
Rosa, D.J.
1993-01-01
This paper analyzes the impact of current and future development of geothermal and hydropower production on the economy of Iceland. Natural conditions in Iceland favor the increased utilization and development of both of these abundant power sources. The mean surface run-off in Iceland is about 50 l/s/km 2 (liters per second per square kilometer), with a large part of the country consisting of a plateau more than 400 meters above sea level. More than half of the country is above 500 meters above sea level. ne technically harnessable hydropower potential is estimated at 64 TWh/year (terawatthours per year), of which 30 TWh/year is considered economically and environmentally harnessable. In addition, Iceland has abundant geothermal energy sources. A quarter of the entire country is a volcanic area. Keeping in mind that geothermal resources are not strictly renewable, it is estimated that the potential power production from this source is 20 TWh/year. Present utilization of these two resources totals only 4.2 TWh/year, or only about 8% of Iceland's aggregate potential. There are many issues facing Iceland today as it considers development opportunities utilizing both of these abundant power supplies. This paper will first consider the technical aspects of both hydropower and geothermal power production in Iceland. Then, the economic consequences of alternative utilization of these energy sources will be evaluated. The first alternative to be considered will be the direct export of power by HVDC submarine cable to other countries, such as Scotland or the United Kingdom. Iceland could, as a second alterative, concentrate its efforts on bringing in energy intensive industries into the country
Di Lodovico, Laura; Dubertret, Caroline; Ameller, Aurely
2018-02-01
Excessive exercise is frequently associated with eating disorders and may degenerate into exercise addiction. We still don't know whether runners at risk for eating disorders are at risk for exercise addiction. Our aim is to assess: 1) risk for exercise addiction in runners at risk for eating disorders and 2) socio-demographic, behavioral and psychological characteristics distinguishing runners at-risk from not-at-risk for eating disorders. We assessed risk for eating disorders and exercise addiction using the SCOFF questionnaire and the Exercise Addiction Inventory personality traits with the Big-Five Inventory Test, socio-demographic data, eating and training habits in a sample of 154 healthy runners. Twenty five subjects had a score of ≥2 at the SCOFF and were included in the group "at risk for eating disorders". In this group, we found a higher percentage of subjects at risk for exercise addiction (p=0.01) and higher average scores at the Exercise Addiction Inventory (p=0.01) than runners not at risk (N=136). Runners at risk were statistically younger (p=0.03), women (p=0.001), started running to lose weight more often (p=0.03), lost more kilos since affiliation in their running club (p=0.04), and were characterized by neurotic traits using the Big-Five-Inventory Test (p=3.10 -6 ). Screening for exercise addiction and mood disorders could lead to a more accurate management of runners at risk for eating disorders. Identifying vulnerable individuals will facilitate the prevention of eating disorders and preserve the benefits of sport practice. Copyright © 2018. Published by Elsevier Inc.
2010-10-05
... Hydropower, Inc.; Notice of Intent To File License Application, Filing of Pre-Application Document, and....: 13563-001. c. Dated Filed: July 28, 2010. d. Submitted By: Juneau Hydropower, Inc. e. Name of Project... Commission's regulations. h. Potential Applicant Contact: Duff W. Mitchell, Juneau Hydropower, Inc., P.O. Box...
2010-08-02
... Hydropower, LLC; Notice of Application Tendered for Filing With the Commission and Soliciting Additional... License. b. Project No.: P-13637-001. c. Date filed: July 12, 2010. d. Applicant: Great River Hydropower.... 21, and would consist of the following facilities: (1) A new hydropower structure, located about 100...
2012-02-08
... Hydropower, LLC; Notice of Intent To File License Application, Filing of Pre-Application Document, and...: December 7, 2011. d. Submitted By: Mahoning Hydropower, LLC. e. Name of Project: Berlin Lake Hydroelectric... Hydropower, LLC, 11365 Normandy Lane, Chagrin Falls, OH 44023; (440) 804-6627; [email protected] i. FERC...
2011-08-17
... Hydropower, Inc.; Notice of Scoping Meeting and Site Visit and Soliciting Scoping Comments for an Applicant...: Alternative Licensing Process. b. Project No.: 13563-001. c. Applicant: Juneau Hydropower, Inc. d. Name of... Mitchell, Business Manager, Juneau Hydropower, Inc., P.O. Box 22775, Juneau, AK 99802; 907-789-2775, e...
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
Resonance sensitivity of hydropower and pumping stations
Energy Technology Data Exchange (ETDEWEB)
Popescu, M.; Halanay, A.
1984-09-01
Comparative analysis of resonance diagrams for several hydropower and pumping stations with surge tanks and air chambers shows large differences in the maximum resonance pressures. A strategy is advocated which consists of hydraulic resonance computations coupled with practical surveillance measures during the operation of resonance sensitive hydraulic systems. A fundamental hydraulic scheme is considered consisting of a reservoir, a pressure tunnel, a surge tank, a penstock and a turbine combined into a hydropower station. It is suggested that for each hydraulic surge system it is necessary to carry out special resonance analyses following the normal procedure to obtain the resonance sensitivity. For hydraulic systems which are resonance sensitive, mechanical electronic equipment should be used to measure non-stationary pressures of the water in the conduit as a way of continuous surveillance during functioning. 6 references, 6 figures.
INFLUENCE OF INJURY ON DYNAMIC POSTURAL CONTROL IN RUNNERS.
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
Reprint of “The future of hydropower in Europe: Interconnecting climate, markets and policies”
International Nuclear Information System (INIS)
Gaudard, Ludovic; Romerio, Franco
2014-01-01
Highlights: • Connecting the knowledges from various domains, in particular economics, engineering, policy and hydrology. • Giving the keys to assess the linking between hydropower, climate and electricity market. • Making an overall analysis. - Abstract: Hydropower is very important for electricity supply security in the European inter-connexion as well as for the economy of regions (primarily peripheral) that possess water resources. Its future may however be jeopardized by several factors: climate change, the development of new renewable energy, the creation of super and micro-grids, and progress in power storage technology. Energy and climate policy, as well as electricity market design and dynamics play a pivotal role. This article carries out a comprehensive analysis of all these factors and discusses the future of hydropower. This discussion follows an overview of the present situation and of future drivers. The technical, environmental, economic and political aspects of the problem are analyzed with an interdisciplinary approach. The stakes as well as the uncertainties are highlighted. The conclusion is that hydropower has a promising future, particularly in light of emerging sustainable energy policy, but that the risks should not be overlooked. Academics will find a comprehensive interdisciplinary analysis of hydropower in this article, whereas public bodies, communities and hydropower companies can identify the strategic variables that should be taken into consideration in the decision making process. The end of water concessions or authorizations is also evoked
Effect of Jet Shape on Flow and Torque Characteristics of Pelton Turbine Runner
Vishal Gupta,; Dr. Vishnu Prasad
2014-01-01
In Pelton turbine, the energy carried by water is converted into kinetic energy by providing nozzle at the end of penstock. The shape of jet affects the force and torque on the bucket and runner of turbine. The nozzle of circular cross section is commonly used. In this paper attempt has been made to study the effect of four different jet shapes on the flow and torque characteristics of Pelton turbine runner through numerical simulation.
Longtan hydropower project and the financial constraints
International Nuclear Information System (INIS)
Ding Zhao.
1995-01-01
China has large untapped resources of hydropower, including such schemes as the Longtan project on the Hongshui river. Despite the attractiveness of the resource and China's need for power, development of these projects is constrained by financial problems. (Author)
International Nuclear Information System (INIS)
Hasler, C.T.; Cooke, S.J.; Patterson, D.A.
2009-01-01
Hydropower infrastructure and the operational strategies used by power utilities have the potential to change local aquatic environments. However, few studies have evaluated sub-organismal responses such as physiological consequences of individual fish to fluctuating flows or hydropower infrastructure such as fishways or turbines. Rather than review the impacts of hydropower on fish, this paper detailed the behavioural, energetic, genomic, molecular, forensic, isotopic, and physiological tools available for studying sub-organismal responses of fish to hydropower infrastructure and operating procedures with a critical assessment of their benefits and limitations. A brief summary of the current state of knowledge regarding the 12 types of tools was provided along with their usefulness in fisheries science and environmental management. The benefits and limitations of using these techniques for evaluating hydropower impacts on fish and fish habitat were discussed. Two case studies were presented to demonstrate how the inclusion of individual-based information into hydropower research has helped to improve the understanding of complex fish and hydropower issues. Practitioners can use the expanded toolbox to assess fishway performance, migration delays, and fish responses to fluctuating flows through a mechanistic approach. These tools are also relevant for evaluating other anthropogenic impacts such as water withdrawal for irrigation or drinking water, habitat alteration, and fisheries interactions. The expanded toolbox can contribute to a more sustainable hydropower industry by providing regulators with tools for making informed decisions and evaluating compliance issues. 150 refs., 1 tab., 4 figs
Cardiovascular Risks in Long Distance Runners.
Witham, Bethany Rolfe; Babbitt, Keven
Distance running has become increasingly popular since the 1970s. Despite the health benefits, long-distance running has been associated with an increased risk for cardiac events. Healthcare professionals should be familiar with distance running cardiac risk factors and preparticipation screening recommendations from the American Heart Association, and should screen and educate patients during healthcare encounters. Nurses are particularly well suited to educate runners on risks and symptoms of cardiac dysfunction.
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...
International Nuclear Information System (INIS)
Siegel, A.J.; Silverman, L.M.; Holman, B.L.
1985-01-01
Elevated cardiac enzyme values in asymptomatic marathon runners after competition can arise from skeletal muscle through exertional rhabdomyolysis, silent injury to the myocardium, or a combined tissue source. Peak post-race levels of the MB isoenzyme of creatine kinase are similar to values in patients with acute myocardial infarction. Previously reported normal results of infarct-avid myocardial scintigraphy with technetium 99m pyrophosphate in runners after competition suggest a non-cardiac source but cannot exclude silent injury to the myocardium. Therefore, thallium 201 myocardial perfusion imaging was performed in runners immediately after competition together with determination of sequential cardiac enzyme levels. Among 15 runners tested, the average peak in serum MB creatine kinase 24 hours after the race was 128 IU/liter with a cumulative MB creatine kinase release of 117 IU/liter; these values are comparable to those in patients with acute transmural myocardial infarction. Thallium 201 myocardial scintigraphic results were normal in five runners randomly selected from those who volunteered for determination of sequential blood levels. It is concluded that elevations of serum MB creatine kinase in marathon runners arise from a skeletal muscle source and that thallium 201 myocardial scintigraphy is useful to assess runners for myocardial injury when clinical questions arise
Energy Technology Data Exchange (ETDEWEB)
Jorde, K.
2007-07-01
This revised final report on the development of a research programme for the Swiss Federal Office of Energy (SFOE) describes the proposals for the development of a concept for Swiss hydropower research activities for the period 2008 - 2011. According to the authors, the new research programme will not only include activities in the small hydropower area, but rather all aspects of hydropower usage, including dams and large hydropower stations. The results of a survey made concerning research and further education in the hydropower area are discussed. These results formed the basis of the new concept. The report also presents a review of the present situation with regard to hydrological questions and dams as well as mechanical and electrical equipment. The education and training of professionals is looked at and national and international co-operation in the hydropower area is also discussed. Future developments are looked at, as are the economic aspects of the use of hydropower. Measures to be taken in the research area are proposed.
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
2011-01-13
... Hydropower, LLC; Notice of Application Accepted for Filing and Soliciting Motions To Intervene and Protests... No.: P-13637-001. c. Date filed: July 12, 2010. d. Applicant: Great River Hydropower, LLC. e. Name of...: (1) A new 796-foot-long by 46-foot-wide by 25-foot-high concrete hydropower structure consisting of...
van Vliet, M. T H; van Beek, L. P H|info:eu-repo/dai/nl/14749799X; Eisner, S.; Flörke, M.; Wada, Y.|info:eu-repo/dai/nl/341387819; Bierkens, M. F P|info:eu-repo/dai/nl/125022794
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
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
Peak Operation of Cascaded Hydropower Plants Serving Multiple Provinces
Directory of Open Access Journals (Sweden)
Jianjian Shen
2015-10-01
Full Text Available The bulk hydropower transmission via trans-provincial and trans-regional power networks in China provides great operational flexibility to dispatch power resources between multiple power grids. This is very beneficial to alleviate the tremendous peak load pressure of most provincial power grids. This study places the focus on peak operations of cascaded hydropower plants serving multiple provinces under a regional connected AC/DC network. The objective is to respond to peak loads of multiple provincial power grids simultaneously. A two-stage search method is developed for this problem. In the first stage, a load reconstruction strategy is proposed to combine multiple load curves of power grids into a total load curve. The purpose is to deal with different load features in load magnitudes, peaks and valleys. A mutative-scale optimization method is then used to determine the generation schedules of hydropower plants. In the second stage, an exterior point search method is established to allocate the generation among multiple receiving power grids. This method produces an initial solution using the load shedding algorithm, and further improves it by iteratively coordinating the generation among different power grids. The proposed method was implemented to the operations of cascaded hydropower plants on Xin-Fu River and another on Hongshui River. The optimization results in two cases satisfied the peak demands of receiving provincial power grids. Moreover, the maximum load difference between peak and valley decreased 12.67% and 11.32% in Shanghai Power Grid (SHPG and Zhejiang Power Grid (ZJPG, exceeding by 4.85% and 6.72% those of the current operational method, respectively. The advantage of the proposed method in alleviating peak-shaving pressure is demonstrated.
Rochat, Nadège; Hauw, Denis; Gür, Gaëlle; Seifert, Ludovic
2018-03-01
Recreational trail runners often participate in online community forums where they can freely read posted messages, join discussions and/or introduce new discussion topics. This tool can enhance learning as runners connect with other trail runners and reflect on how they can better organize their own practice. Studying forum activity would provide greater insight into the relationship between field practice and dedicated forums. The aim of this study was therefore to detect the topics discussed online by trail runners in order to understand how they collectively look for solutions that help them adapt to issues that emerge during actual practice. The discussion topics (n = 171) on the forum hosted by the Raidlight brand were examined using inductive content analysis, which distinguished two general dimensions. The first dimension was training and had four first-order themes (i.e., "specific trail running sessions", "complementary trail running sessions". "training plans" and "specific questions about races") grouped into two second-order themes (i.e., "training session contents" and "structure and schedule"). The second dimension was health and had seven first-order themes (i.e., "tendinitis", "muscle issues", "foot issues", "sprains and fractures", "pain", "physiology" and "substances and practitioners") grouped into two second-order themes (i.e., "pain and injury" and "prevention"). The results indicate that the issues that trail runners discuss on forums are significant and that the successions of questions and solutions are a fruitful means for building, enriching and adjusting their activity as they cope with constraints. As a practical consequence, suggestions for improving such online platforms are made.
The role of energy systems on hydropower in Turkey
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.
Small hydropower plants in the region of Mariovo (Macedonia)
International Nuclear Information System (INIS)
Panovski, Sotir; Anastasov, Ljupcho
2003-01-01
In this paper the results of an initial Pre-feasibility study within the framework of the PHARE Programme for Cross Border Cooperation between Republic of Macedonia and Republic of Greece. In this study we have looked at the existing research originating from three sources. The Strategies for Economic Development of Republic of Macedonia, the Development Plans of the Electric Power Company of Macedonia as well as the existing technical documentation and studies on a level of idea projects for specific location for small hydropower plants in Mariovo region. Furthermore, analysis and evaluation of this documentation is included. Research done in this region has produced evidence of numerous potential locations for small hydropower plants (total of 46) generating power between 58 kW and 4900 kW, discharging between 0,082 m 3 /s and 30 m 3 /s with a head between 6 m and 208 m for which we have detailed data. Furthermore, in the paper we pay attention to the enormous and so far unrealised hydro energetic power which could be utilised by constructing small hydropower plants in Republic of Macedonia. specifically in the Mariovo region. (Original)
Exploring Experience of Runners with Sports Tracking Technology
Kuru, Armagan
2016-01-01
Running has been perceived as an easy way of becoming physically active. Over time, amateur runners start to use technology to keep track of their training and be aware of their improvement. In that sense, this article explores runners’ experience with activity tracking technology. After giving a
Vesterinen, V; Häkkinen, K; Hynynen, E; Mikkola, J; Hokka, L; Nummela, A
2013-03-01
The aim of this study was to investigate whether nocturnal heart rate variability (HRV) can be used to predict changes in endurance performance during 28 weeks of endurance training. The training was divided into 14 weeks of basic training (BTP) and 14 weeks of intensive training periods (ITP). Endurance performance characteristics, nocturnal HRV, and serum hormone concentrations were measured before and after both training periods in 28 recreational endurance runners. During the study peak treadmill running speed (Vpeak ) improved by 7.5 ± 4.5%. No changes were observed in HRV indices after BTP, but after ITP, these indices increased significantly (HFP: 1.9%, P=0.026; TP: 1.7%, P=0.007). Significant correlations were observed between the change of Vpeak and HRV indices (TP: r=0.75, PHRV among recreational endurance runners, it seems that moderate- and high-intensity training are needed. This study showed that recreational endurance runners with a high HRV at baseline improved their endurance running performance after ITP more than runners with low baseline HRV. © 2011 John Wiley & Sons A/S.
International Nuclear Information System (INIS)
Kelly-Richards, Sarah; Silber-Coats, Noah; Crootof, Arica; Tecklin, David; Bauer, Carl
2017-01-01
The transition to renewable energy technologies raises new and important governance questions. With small hydropower (SHP) expanding as part of renewable energy and climate mitigation strategies, this review assesses its impacts and identifies escalating policy issues. To provide a comprehensive literature review of small hydropower, we evaluated over 3600 articles and policy documents. This review identified four major concerns: (1) confusion in small hydropower definitions is convoluting scholarship and policy-making; (2) there is a lack of knowledge and acknowledgement of small hydropower’s social, environmental, and cumulative impacts; (3) small hydropower’s promotion as a climate mitigation strategy can negatively affect local communities, posing contradictions for climate change policy; and (4) institutional analysis is needed to facilitate renewable energy integration with existing environmental laws to ensure sustainable energy development. For readers interested in small hydropower, we clarify areas of confusion in definition and explain the corresponding impacts for distinct system designs. For a broader readership, we situate small hydropower implementation within international trends of renewable energy development – the contradictory impacts of climate change policy, emerging dynamics in energy finance, and reliance on market mechanisms. Our paper provides a timely contribution to scholarship on small hydropower and the transition to renewable energy. - Highlights: • Confusion in small hydropower definitions is convoluting small hydropower debates. • Small hydropower’s negative impacts are largely overlooked in policy discussions. • Small hydropower exemplifies paradoxical problems with climate change policy. • Policies needed to integrate renewable energy development with national environmental institutions.
International Nuclear Information System (INIS)
Mirumachi, Naho; Torriti, Jacopo
2012-01-01
Gaining public acceptance is one of the main issues with large-scale low-carbon projects such as hydropower development. It has been recommended by the World Commission on Dams that to gain public acceptance, public involvement is necessary in the decision-making process (). As financially-significant actors in the planning and implementation of large-scale hydropower projects in developing country contexts, the paper examines the ways in which public involvement may be influenced by international financial institutions. Using the case study of the Nam Theun 2 Hydropower Project in Laos, the paper analyses how public involvement facilitated by the Asian Development Bank had a bearing on procedural and distributional justice. The paper analyses the extent of public participation and the assessment of full social and environmental costs of the project in the Cost-Benefit Analysis conducted during the project appraisal stage. It is argued that while efforts were made to involve the public, there were several factors that influenced procedural and distributional justice: the late contribution of the Asian Development Bank in the project appraisal stage; and the issue of non-market values and discount rate to calculate the full social and environmental costs. - Highlights: ► Public acceptance in large-scale hydropower projects is examined. ► Both procedural and distributional justice are important for public acceptance. ► International Financial Institutions can influence the level of public involvement. ► Public involvement benefits consideration of non-market values and discount rates.
Hespanhol Junior, Luiz Carlos; Pena Costa, Leonardo Oliveira; Lopes, Alexandre Dias
2013-12-01
What is the incidence of running-related injuries (RRIs) in recreational runners? Which personal and training characteristics predict RRIs in recreational runners? Prospective cohort study. A total of 200 recreational runners answered a fortnightly online survey containing questions about their running routine, races, and presence of RRI. These runners were followed-up for a period of 12 weeks. The primary outcome of this study was running-related injury. The incidence of injuries was calculated taking into account the exposure to running and was expressed by RRI/1000 hours. The association between potential predictive factors and RRIs was estimated using generalised estimating equation models. A total of 84 RRIs were registered in 60 (31%) of the 191 recreational runners who completed all follow-up surveys. Of the injured runners 30% (n=18/60) developed two or more RRIs, with 5/18 (28%) being recurrences. The incidence of RRI was 10 RRI/1000 hours of running exposure. The main type of RRI observed was muscle injuries (30%, n=25/84). The knee was the most commonly affected anatomical region (19%, n=16/84). The variables associated with RRI were: previous RRI (OR 1.88, 95% CI 1.01 to 3.51), duration of training although the effect was very small (OR 1.01, 95% CI 1.00 to 1.02), speed training (OR 1.46, 95% CI 1.02 to 2.10), and interval training (OR 0.61, 95% CI 0.43 to 0.88). Physiotherapists should be aware and advise runners that past RRI and speed training are associated with increased risk of further RRI, while interval training is associated with lower risk, although these associations may not be causative. Copyright © 2013 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.
Hydropower, an energy source whose time has come again
1980-01-01
Recent price increases in imported oil demonstrate the urgency for the U.S. to rapidly develop its renewable resources. One such renewable resource for which technology is available now is hydropower. Studies indicate that hydropower potential, particularly at existing dam sites, can save the county hundreds of thousands of barrels of oil per day. But problems and constraints-economic, environmental, institutional, and operational-limit is full potential. Federal programs have had little impact on helping to bring hydro projects on line. Specifically, the Department of Energy's Small Hydro Program could do more to overcome hydro constraints and problems through an effective outreach program and more emphasis on demonstration projects.
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.
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.
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.
Veselka, T. D.; Poch, L.
2011-12-01
Integrating high penetration levels of wind and solar energy resources into the power grid is a formidable challenge in virtually all interconnected systems due to the fact that supply and demand must remain in balance at all times. Since large scale electricity storage is currently not economically viable, generation must exactly match electricity demand plus energy losses in the system as time unfolds. Therefore, as generation from variable resources such as wind and solar fluctuate, production from generating resources that are easier to control and dispatch need to compensate for these fluctuations while at the same time respond to both instantaneous change in load and follow daily load profiles. The grid in the Western U.S. is not exempt to grid integration challenges associated with variable resources. However, one advantage that the power system in the Western U.S. has over many other regional power systems is that its footprint contains an abundance of hydropower resources. Hydropower plants, especially those that have reservoir water storage, can physically change electricity production levels very quickly both via a dispatcher and through automatic generation control. Since hydropower response time is typically much faster than other dispatchable resources such as steam or gas turbines, it is well suited to alleviate variable resource grid integration issues. However, despite an abundance of hydropower resources and the current low penetration of variable resources in the Western U.S., problems have already surfaced. This spring in the Pacific Northwest, wetter than normal hydropower conditions in combination with transmission constraints resulted in controversial wind resource shedding. This action was taken since water spilling would have increased dissolved oxygen levels downstream of dams thereby significantly degrading fish habitats. The extent to which hydropower resources will be able to contribute toward a stable and reliable Western grid is
Vitamin and mineral intake of twelve adolescent male Kalenjin runners in western Kenya
DEFF Research Database (Denmark)
Christensen, Dirk Lund; Jakobsen, Jette; Friis, H
2005-01-01
runners was carried out to determine their micronutrient intake. MAIN OUTCOME MEASURES: Over a two-week period, samples of the main eaten food were collected for analysis of micronutrient distribution and a daily 24 recall interview performed to determine additional food intake. RESULTS: The estimated...... mg, 1309 microg, and 79 microg, respectively. CONCLUSION: Total daily micronutrient intake of the twelve Kalenjin runners was far from adequate compared to FAO/WHO daily recommended and suggested adequate intake....
Racial Discrimination Towards the Hazaras as Reflected in Khaled Hosseini's the Kite Runner
Handayani, Fadlilah Satya
2016-01-01
Khaled Hosseini's novel entitled The Kite Runner is an American bestseller novel that represents racial conflict between the Pashtuns and Hazaras, two different races and ethnics in Afghanistan. The aims of this study are to find out the causes of racial discrimination, to analyze examples of racial discrimination, and to analyze the impacts of racial discrimination as depicted in The Kite Runner. Sociological approach and theories on racism and racial discrimination are used in this study. T...
Impact of glacier shrinkage and adapted hydropower potential in the Swiss Alps
International Nuclear Information System (INIS)
Terrier, Stephane; Bieri, Martin; Jordan, Frederic; Schleiss, Anton J.
2015-01-01
Global warming is an alarming reality and likely leads to an increase of multiple pressures on socio-economic systems. However, in high-mountain regions it might also become an opportunity to adapt existing hydropower schemes and to develop new projects to this reality. In the Alps, the melting of glaciers first produces over the near future an increase of the average annual discharge depending on glacier and catchment characteristics, especially during the summer season. Nevertheless after a certain time, significant decrease of runoff related to glacier melting must be considered for hydropower management. Moreover, the shrinking glaciers free new areas, having the potential for the construction of new dams and reservoirs. The opportunity to build new dams and hydropower plants downstream of retreating glaciers is studied using two models. The first (GlabTop) is used to predict the future topography and geomorphology underneath the melting glaciers, in order to define the optimal locations of the future dams and reservoirs. Secondly, the RS3.0 CLIMATE rainfall-runoff hydrological model computes the glacier evolution, the river discharge at the outlet of the catchment area as well as the hydropower production of the new schemes. As a case study the Upper Aare River basin in Switzerland is presented. The opportunity of the construction of a new dam and a hydropower plant is studied, including its economic benefit. The result of the case study provides a basis to assess the potential of investing in such projects to ensure the Swiss hydroelectricity production also in future as well as peak energy for the European grid. (authors)
Emotions and trait emotional intelligence among ultra-endurance runners.
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.
Steady and transient regimes in hydropower plants
Gajic, A.
2013-12-01
Hydropower plant that has been in operation for about 30 years has to be reconstructed. They have already installed 12 Kaplan turbines, the largest in the world at that time. The existing CAM relationship was determined based on hydraulic model tests and checked by efficiency on-site tests. It was also tested based on turbine bearing vibrations. In order to discover vibrations and long cracks on stay vanes detailed on-site measurements were performed. Influence of the modification of the trailing edges on the dynamic stresses of the stay vanes is also shown. In order to improve power output transient regimes were analyzed, both experimentally and numerically. Reversible hydropower plant, a pioneer in Europe since it was the first Pump storage power plant constructed with the highest head pump-turbines in the world. Analyses of transient regimes discover some problems with S-shaped characteristics coupled with non-symmetrical penstock.
Steady and transient regimes in hydropower plants
International Nuclear Information System (INIS)
Gajic, A
2013-01-01
Hydropower plant that has been in operation for about 30 years has to be reconstructed. They have already installed 12 Kaplan turbines, the largest in the world at that time. The existing CAM relationship was determined based on hydraulic model tests and checked by efficiency on-site tests. It was also tested based on turbine bearing vibrations. In order to discover vibrations and long cracks on stay vanes detailed on-site measurements were performed. Influence of the modification of the trailing edges on the dynamic stresses of the stay vanes is also shown. In order to improve power output transient regimes were analyzed, both experimentally and numerically. Reversible hydropower plant, a pioneer in Europe since it was the first Pump storage power plant constructed with the highest head pump-turbines in the world. Analyses of transient regimes discover some problems with S-shaped characteristics coupled with non-symmetrical penstock
Some physiological demands of a half-marathon race on recreational runners.
Williams, C; Nute, M L
1983-09-01
The purpose of this study was to assess the physiological demands of a half-marathon race on a group of ten recreational runners (8 men and 2 women). The average running speed was 223.1 +/- 22.7 m.min-1 (mean +/- SD) for the group and this represented 79 +/- 5% VO2 max for these runners. There was a good correlation between VO2 max and performance time for the race (4 = -0.81; p less than 0.01) and an even better correlation between running speed equivalent to a blood lactate concentration of 4 mmol.l-1 and performance times (r = -0.877; p less than 0.01). The blood lactate concentration os 4 of the runners at the end of the race was 5.65 +/- 1.42 mmol.l-1 (mean +/- SD) and the estimated energy expenditure for the group was 6.22 M.J. While there was only a poor correlation between total energy expenditure and performance time for the race, the correlation coefficient was improved when the energy expenditure of each individual was expressed in KJ.kg-1 min-1 (r = 0.938; p less than 0.01).
Kinetic Risk Factors of Running-Related Injuries in Female Recreational Runners.
Napier, Christopher; MacLean, Christopher L; Maurer, Jessica; Taunton, Jack E; Hunt, Michael A
2018-05-30
Our objective was to prospectively investigate the association of kinetic variables with running-related injury (RRI) risk. Seventy-four healthy female recreational runners ran on an instrumented treadmill while 3D kinetic and kinematic data were collected. Kinetic outcomes were vertical impact transient, average vertical loading rate, instantaneous vertical loading rate, active peak, vertical impulse, and peak braking force (PBF). Participants followed a 15-week half-marathon training program. Exposure time (hours of running) was calculated from start of program until onset of injury, loss to follow-up, or end of program. After converting kinetic variables from continuous to ordinal variables based on tertiles, Cox proportional hazard models with competing risks were fit for each variable independently, before analysis in a forward stepwise multivariable model. Sixty-five participants were included in the final analysis, with a 33.8% injury rate. PBF was the only kinetic variable that was a significant predictor of RRI. Runners in the highest tertile (PBF recreational runners and should be considered as a target for gait retraining interventions. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.