Local diurnal wind-driven variabiity and upwelling in a small coastal embayment

NASA Astrophysics Data System (ADS)

Walter, R. K.; Reid, E. C.; Davis, K. A.; Armenta, K. J.; Merhoff, K.; Nidzieko, N.

2017-12-01

The oceanic response to high-frequency local diurnal wind forcing is examined in a small coastal embayment located along an understudied stretch of the central California coast. We show that local diurnal wind forcing is the dominant control on nearshore temperature variability and circulation patterns. A complex empirical orthogonal function (CEOF) analysis of velocities in San Luis Obispo Bay reveals that the first-mode CEOF amplitude time series, which accounts for 47.9% of the variance, is significantly coherent with the local wind signal at the diurnal frequency and aligns with periods of weak and strong wind forcing. The diurnal evolution of the hydrographic structure and circulation in the bay is examined using both individual events and composite-day averages. During the late afternoon, the local wind strengthens and results in a sheared flow with near-surface warm waters directed out of the bay and a compensating flow of colder waters into the bay over the bottom portion of the water column. This cold water intrusion into the bay causes isotherms to shoal toward the surface and delivers subthermocline waters to shallow reaches of the bay, representing a mechanism for small-scale upwelling. When the local winds relax, the warm water mass advects back into the bay in the form of a buoyant plume front. Local diurnal winds are expected to play an important role in nearshore dynamics and local upwelling in other small coastal embayments with important implications for various biological and ecological processes.

Local diurnal wind-driven variability and upwelling in a small coastal embayment

NASA Astrophysics Data System (ADS)

Walter, Ryan K.; Reid, Emma C.; Davis, Kristen A.; Armenta, Kevin J.; Merhoff, Kevin; Nidzieko, Nicholas J.

2017-02-01

The oceanic response to high-frequency local diurnal wind forcing is examined in a small coastal embayment located along an understudied stretch of the central California coast. We show that local diurnal wind forcing is the dominant control on nearshore temperature variability and circulation patterns. A complex empirical orthogonal function (CEOF) analysis of velocities in San Luis Obispo Bay reveals that the first-mode CEOF amplitude time series, which accounts for 47.9% of the variance, is significantly coherent with the local wind signal at the diurnal frequency and aligns with periods of weak and strong wind forcing. The diurnal evolution of the hydrographic structure and circulation in the bay is examined using both individual events and composite-day averages. During the late afternoon, the local wind strengthens and results in a sheared flow with near-surface warm waters directed out of the bay and a compensating flow of colder waters into the bay over the bottom portion of the water column. This cold water intrusion into the bay causes isotherms to shoal toward the surface and delivers subthermocline waters to shallow reaches of the bay, representing a mechanism for small-scale upwelling. When the local winds relax, the warm water mass advects back into the bay in the form of a buoyant plume front. Local diurnal winds are expected to play an important role in nearshore dynamics and local upwelling in other small coastal embayments with important implications for various biological and ecological processes.

Quiet airfoils for small and large wind turbines

DOEpatents

Tangler, James L [Boulder, CO; Somers, Dan L [Port Matilda, PA

2012-06-12

Thick airfoil families with desirable aerodynamic performance with minimal airfoil induced noise. The airfoil families are suitable for a variety of wind turbine designs and are particularly well-suited for use with horizontal axis wind turbines (HAWTs) with constant or variable speed using pitch and/or stall control. In exemplary embodiments, a first family of three thick airfoils is provided for use with small wind turbines and second family of three thick airfoils is provided for use with very large machines, e.g., an airfoil defined for each of three blade radial stations or blade portions defined along the length of a blade. Each of the families is designed to provide a high maximum lift coefficient or high lift, to exhibit docile stalls, to be relatively insensitive to roughness, and to achieve a low profile drag.

FEM Simulation of Small Wind Power Generating System Using PMSG

NASA Astrophysics Data System (ADS)

Kesamaru, Katsumi; Ohno, Yoshihiro; Sonoda, Daisuke

The paper describes a new approach to simulate the small wind power generating systems using PMSG, in which the output is connected to constant resistive load, such as heaters, through the rectifier and the dc chopper. The dynamics of the wind power generating system is presented, and it is shown by simulation results that this approach is useful for system dynamics, such as starting phenomena.

Small Wind Electric Systems: A Guide Produced for the Tennessee Valley Authority (Revised) (Brochure)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2009-06-01

Small Wind Electric Systems: A Guide Produced for the Tennessee Valley Authority provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connectmore » a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a regional wind resource map and a list of incentives and contacts for more information.« less

Small Horizontal Axis Wind Turbine under High Speed Operation: Study of Power Evaluation

NASA Astrophysics Data System (ADS)

Moh. M. Saad, Magedi; Mohd, Sofian Bin; Zulkafli, Mohd Fadhli Bin; Abdullah, Aslam Bin; Rahim, Mohammad Zulafif Bin; Subari, Zulkhairi Bin; Rosly, Nurhayati Binti

2017-10-01

Mechanical energy is produced through the rotation of wind turbine blades by air that convert the mechanical energy into electrical energy. Wind turbines are usually designed to be use for particular applications and design characteristics may vary depending on the area of use. The variety of applications is reflected on the size of turbines and their infrastructures, however, performance enhancement of wind turbine may start by analyzing the small horizontal axis wind turbine (SHAWT) under high wind speed operation. This paper analyzes the implementations of SHAWT turbines and investigates their performance in both simulation and real life. Depending on the real structure of the rotor geometry and aerodynamic test, the power performance of the SHAWT was simulated using ANSYS-FLUENT software at different wind speed up to 33.33 m/s (120km/h) in order to numerically investigate the actual turbine operation. Dynamic mesh and user define function (UDF) was used for revolving the rotor turbine via wind. Simulation results were further validated by experimental data and hence good matching was yielded. And for reducing the energy producing cost, car alternator was formed to be used as a small horizontal wind turbine. As a result, alternator-based turbine system was found to be a low-cost solution for exploitation of wind energy.

Active Tailoring of Lift Distribution to Enhance Cruise Performance

NASA Technical Reports Server (NTRS)

Flamm, Jeffrey D. (Technical Monitor); Pfeiffer, Neal J.; Christians, Joel G.

2005-01-01

During Phase I of this project, Raytheon Aircraft Company (RAC) has analytically and experimentally evaluated key components of a system that could be implemented for active tailoring of wing lift distribution using low-drag, trailing-edge modifications. Simple systems such as those studied by RAC could be used to enhance the cruise performance of a business jet configuration over a range of typical flight conditions. The trailing-edge modifications focus on simple, deployable mechanisms comprised of extendable small flap panels over portions of the span that could be used to subtly but positively optimize the lift and drag characteristics. The report includes results from low speed wind tunnel testing of the trailing-edge devices, descriptions of potential mechanisms for automation, and an assessment of the technology.

Small wind systems field evaluation. Volume I. Program description. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dodge, D.M.; Liske, C.

1982-07-01

A Field Evaluation Program (FEP) was developed in 1978 to assist in the commercialization process for small wind systems. The program is described, and a description is provided of the institutional issues and barriers encountered and measures taken to assist the state and local governments in resolving them. Barriers were found to involve not only government regulations, but also the distribution of costs and benefits of wind technology and the rate of diffusion of knowledge about wind technology. The availability of capital to finance the production and purchase of wind machines, and the training of qualified dealers and service personnelmore » were also considerable problem areas. (LEW)« less

Navy Applications Experience with Small Wind Power Systems

DTIC Science & Technology

1985-05-01

present state-of-the-art in small WECS technology, including environmental concerns, is reviewed. Also presented is how the technology is advancing to...environmental concerns, is reviewed. Also presented is how the technology is advancing to improve reliability and avail- ability for effectively using...VAWT technology is still in its early stages of development. The horizontal-axis wind turbine (HAWT) technology has advanced to third and fourth

Analyzing the dynamic response of rotating blades in small-scale wind turbines

NASA Astrophysics Data System (ADS)

Hsiung, Wan-Ying; Huang, Yu-Ting; Loh, Chin-Hsiung; Loh, Kenneth J.; Kamisky, Robert J.; Nip, Danny; van Dam, Cornelis

2014-03-01

The objective of this study was to validate modal analysis, system identification and damage detection of small-scale rotating wind turbine blades in the laboratory and in the field. Here, wind turbine blades were instrumented with accelerometers and strain gages, and data acquisition was achieved using a prototype wireless sensing system. In the first portion of this study conducted in the laboratory, sensors were installed onto metallic structural elements that were fabricated to be representative of an actual wind blade. In order to control the excitation (rotation of the wind blade), a motor was used to spin the blades at controlled angular velocities. The wind turbine was installed on a shaking table for testing under rotation of turbine blades. Data measured by the sensors were recorded while the blade was operated at different speeds. On the other hand, the second part of this study utilized a small-scale wind turbine system mounted on the rooftop of a building. The main difference, as compared to the lab tests, was that the field tests relied on actual wind excitations (as opposed to a controlled motor). The raw data from both tests were analyzed using signal processing and system identification techniques for deriving the model response of the blades. The multivariate singular spectrum analysis (MSSA) and covariance-driven stochastic subspace identification method (SSI-COV) were used to identify the dynamic characteristics of the system. Damage of one turbine blade (loose bolts connection) in the lab test was also conducted. The extracted modal properties for both undamaged and damage cases under different ambient or forced excitations (earthquake loading) were compared. These tests confirmed that dynamic characterization of rotating wind turbines was feasible, and the results will guide future monitoring studies planned for larger-scale systems.

Jobs and Economic Development Impacts from Small Wind: JEDI Model in the Works (Presentation)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tegen, S.

2012-06-01

This presentation covers the National Renewable Energy Laboratory's role in economic impact analysis for wind power Jobs and Economic Development Impacts (JEDI) models, JEDI results, small wind JEDI specifics, and a request for information to complete the model.

Development and comparisons of wind retrieval algorithms for small unmanned aerial systems

NASA Astrophysics Data System (ADS)

Bonin, T. A.; Chilson, P. B.; Zielke, B. S.; Klein, P. M.; Leeman, J. R.

2012-12-01

Recently, there has been an increase in use of Unmanned Aerial Systems (UASs) as platforms for conducting fundamental and applied research in the lower atmosphere due to their relatively low cost and ability to collect samples with high spatial and temporal resolution. Concurrent with this development comes the need for accurate instrumentation and measurement methods suitable for small meteorological UASs. Moreover, the instrumentation to be integrated into such platforms must be small and lightweight. Whereas thermodynamic variables can be easily measured using well aspirated sensors onboard, it is much more challenging to accurately measure the wind with a UAS. Several algorithms have been developed that incorporate GPS observations as a means of estimating the horizontal wind vector, with each algorithm exhibiting its own particular strengths and weaknesses. In the present study, the performance of three such GPS-based wind-retrieval algorithms has been investigated and compared with wind estimates from rawinsonde and sodar observations. Each of the algorithms considered agreed well with the wind measurements from sounding and sodar data. Through the integration of UAS-retrieved profiles of thermodynamic and kinematic parameters, one can investigate the static and dynamic stability of the atmosphere and relate them to the state of the boundary layer across a variety of times and locations, which might be difficult to access using conventional instrumentation.

Comparison and application of wind retrieval algorithms for small unmanned aerial systems

NASA Astrophysics Data System (ADS)

Bonin, T. A.; Chilson, P. B.; Zielke, B. S.; Klein, P. M.; Leeman, J. R.

2013-07-01

Recently, there has been an increase in use of Unmanned Aerial Systems (UASs) as platforms for conducting fundamental and applied research in the lower atmosphere due to their relatively low cost and ability to collect samples with high spatial and temporal resolution. Concurrent with this development comes the need for accurate instrumentation and measurement methods suitable for small meteorological UASs. Moreover, the instrumentation to be integrated into such platforms must be small and lightweight. Whereas thermodynamic variables can be easily measured using well-aspirated sensors onboard, it is much more challenging to accurately measure the wind with a UAS. Several algorithms have been developed that incorporate GPS observations as a means of estimating the horizontal wind vector, with each algorithm exhibiting its own particular strengths and weaknesses. In the present study, the performance of three such GPS-based wind-retrieval algorithms has been investigated and compared with wind estimates from rawinsonde and sodar observations. Each of the algorithms considered agreed well with the wind measurements from sounding and sodar data. Through the integration of UAS-retrieved profiles of thermodynamic and kinematic parameters, one can investigate the static and dynamic stability of the atmosphere and relate them to the state of the boundary layer across a variety of times and locations, which might be difficult to access using conventional instrumentation.

Planetary Wind Determination by Doppler Tracking of a Small Entry Probe Network

NASA Astrophysics Data System (ADS)

Atkinson, D. H.; Asmar, S.; Lazio, J.; Preston, R. A.

2017-12-01

To understand the origin and chemical/dynamical evolution of planetary atmospheres, measurements of atmospheric chemistries and processes including dynamics are needed. In situ measurements of planetary winds have been demonstrated on multiple occasions, including the Pioneer multiprobe and Venera missions to Venus, and the Galileo/Jupiter and Huygens/Titan probes. However, with the exception of Pioneer Venus, the retrieval of the zonal (east-west) wind profile has been limited to a single atmospheric slice. significantly improved understanding of the global dynamics requires sampling of multiple latitudes, times of day, and seasons. Simultaneous tracking of a small network of probes would enable measurements of spatially distributed winds providing a substantially improved characterization of a planet's global atmospheric circulation. Careful selection of descent locations would provide wind measurements at latitudes receiving different solar insolations, longitudes reflecting different times of day, and different seasons if both hemispheres are targeted. Doppler wind retrievals are limited by the stability of the probe and carrier spacecraft clocks, and must be equipped with an ultrastable oscillator, accelerometers for reconstructing the probe entry trajectory, and pressure / temperature sensors for determination of descent speed. A probe were equipped with both absolute and dynamic pressure sensors can measure planet center-relative and atmosphere-relative descent speeds, enabling the measurement of vertical winds from convection or atmospheric waves. Possible ambiguities arising from the assumption of no north-south winds could be removed if the probe were simultaneously tracked from the carrier spacecraft as well as from the Earth or a second spacecraft. The global circulation of an atmosphere comprising waves and flows that vary with location and depth is inherently tied to the thermal, chemical, and energy structure of the atmosphere. Wind measurements

Small is different: RPC observations of a small scale comet interacting with the solar wind

NASA Astrophysics Data System (ADS)

Nilsson, Hans; Burch, James L.; Carr, Christopher M.; Eriksson, Anders I.; Glassmeier, Karl-Heinz; Henri, Pierre; Rosetta Plasma Consortium Team

2016-10-01

Rosetta followed comet 67P from low activity at more than 3 AU heliocentric distance to peak activity at perihelion and then out again. We study the evolution of the dynamic plasma environment using data from the Rosetta Plasma Consortium (RPC). Observations of cometary plasma began in August 2014, at a distance of 100 km from the comet nucleus and at 3.6 AU from the Sun. As the comet approached the Sun, outgassing from the comet increased, as did the density of the cometary plasma. Measurements showed a highly heterogeneous cold ion environment, permeated by the solar wind. The solar wind was deflected due to the mass loading from newly added cometary plasma, with no discernible slowing down. The magnetic field magnitude increased significantly above the background level, and strong low frequency waves were observed in the magnetic field, a.k.a. the "singing comet". Electron temperatures were high, leading to a frequently strongly negative spacecraft potential. In mid to late April 2015 the solar wind started to disappear from the observation region. This was associated with a solar wind deflection reaching nearly 180°, indicating that mass loading became efficient enough to form a solar wind-free region. Accelerated water ions, moving mainly in the anti-sunward direction, kept being observed also after the solar wind disappearance. Plasma boundaries began to form and a collisionopause was tentatively identified in the ion and electron data. At the time around perihelion, a diamagnetic cavity was also observed, at a surprisingly large distance from the comet. In late 2016 the solar wind re-appeared at the location of Rosetta, allowing for studies of asymmetry of the comet ion environment with respect to perihelion. A nightside excursion allowed us to get a glimpse of the electrodynamics of the innermost part of the plasma tail. Most of these phenomena are dependent on the small-scale physics of comet 67P, since for most of the Rosetta mission the solar wind

Economic analysis of small wind-energy conversion systems

NASA Astrophysics Data System (ADS)

Haack, B. N.

1982-05-01

A computer simulation was developed for evaluating the economics of small wind energy conversion systems (SWECS). Input parameters consisted of initial capital investment, maintenance and operating costs, the cost of electricity from other sources, and the yield of electricity. Capital costs comprised the generator, tower, necessity for an inverter and/or storage batteries, and installation, in addition to interest on loans. Wind data recorded every three hours for one year in Detroit, MI was employed with a 0.16 power coefficient to extrapolate up to hub height as an example, along with 10 yr of use variances. A maximum return on investment was found to reside in using all the energy produced on site, rather than selling power to the utility. It is concluded that, based on a microeconomic analysis, SWECS are economically viable at present only where electric rates are inordinately high, such as in remote regions or on islands.

A Comprehensive Analysis of Small-Passerine Fatalities from Collision with Turbines at Wind Energy Facilities

PubMed Central

Erickson, Wallace P.; Wolfe, Melissa M.; Bay, Kimberly J.; Johnson, Douglas H.; Gehring, Joelle L.

2014-01-01

Small passerines, sometimes referred to as perching birds or songbirds, are the most abundant bird group in the United States (US) and Canada, and the most common among bird fatalities caused by collision with turbines at wind energy facilities. We used data compiled from 116 studies conducted in the US and Canada to estimate the annual rate of small-bird fatalities. It was necessary for us to calculate estimates of small-bird fatality rates from reported all-bird rates for 30% of studies. The remaining 70% of studies provided data on small-bird fatalities. We then adjusted estimates to account for detection bias and loss of carcasses from scavenging. These studies represented about 15% of current operating capacity (megawatts [MW]) for all wind energy facilities in the US and Canada and provided information on 4,975 bird fatalities, of which we estimated 62.5% were small passerines comprising 156 species. For all wind energy facilities currently in operation, we estimated that about 134,000 to 230,000 small-passerine fatalities from collision with wind turbines occur annually, or 2.10 to 3.35 small birds/MW of installed capacity. When adjusted for species composition, this indicates that about 368,000 fatalities for all bird species are caused annually by collisions with wind turbines. Other human-related sources of bird deaths, (e.g., communication towers, buildings [including windows]), and domestic cats) have been estimated to kill millions to billions of birds each year. Compared to continent-wide population estimates, the cumulative mortality rate per year by species was highest for black-throated blue warbler and tree swallow; 0.043% of the entire population of each species was estimated to annually suffer mortality from collisions with turbines. For the eighteen species with the next highest values, this estimate ranged from 0.008% to 0.038%, much lower than rates attributed to collisions with communication towers (1.2% to 9.0% for top twenty species). PMID

A comprehensive analysis of small-passerine fatalities from collisions with turbines at wind energy facilities

USGS Publications Warehouse

Erickson, Wallace P.; Wolfe, Melissa M.; Bay, Kimberly J.; Johnson, Douglas H.; Gehring, Joelle L.

2014-01-01

Small passerines, sometimes referred to as perching birds or songbirds, are the most abundant bird group in the United States (US) and Canada, and the most common among bird fatalities caused by collision with turbines at wind energy facilities. We used data compiled from 39 studies conducted in the US and Canada to estimate the annual rate of small-bird fatalities. It was necessary for us to calculate estimates of small-bird fatality rates from reported all-bird rates for 30% of studies. The remaining 70% of studies provided data on small-bird fatalities. We then adjusted estimates to account for detection bias and loss of carcasses from scavenging. These studies represented about 15% of current operating capacity (megawatts [MW]) for all wind energy facilities in the US and Canada and provided information on 4,975 bird fatalities, of which we estimated 62.5% were small passerines comprising 156 species. For all wind energy facilities currently in operation, we estimated that about 134,000 to 230,000 small-passerine fatalities from collision with wind turbines occur annually, or 2.10 to 3.35 small birds/MW of installed capacity. When adjusted for species composition, this indicates that about 368,000 fatalities for all bird species are caused annually by collisions with wind turbines. Other human-related sources of bird deaths, (e.g., communication towers, buildings [including windows]), and domestic cats) have been estimated to kill millions to billions of birds each year. Compared to continent-wide population estimates, the cumulative mortality rate per year by species was highest for black-throated blue warbler and tree swallow; 0.043% of the entire population of each species was estimated to annually suffer mortality from collisions with turbines. For the eighteen species with the next highest values, this estimate ranged from 0.008% to 0.038%, much lower than rates attributed to collisions with communication towers (1.2% to 9.0% for top twenty species).

A comprehensive analysis of small-passerine fatalities from collision with turbines at wind energy facilities.

PubMed

Erickson, Wallace P; Wolfe, Melissa M; Bay, Kimberly J; Johnson, Douglas H; Gehring, Joelle L

2014-01-01

Small passerines, sometimes referred to as perching birds or songbirds, are the most abundant bird group in the United States (US) and Canada, and the most common among bird fatalities caused by collision with turbines at wind energy facilities. We used data compiled from 116 studies conducted in the US and Canada to estimate the annual rate of small-bird fatalities. It was necessary for us to calculate estimates of small-bird fatality rates from reported all-bird rates for 30% of studies. The remaining 70% of studies provided data on small-bird fatalities. We then adjusted estimates to account for detection bias and loss of carcasses from scavenging. These studies represented about 15% of current operating capacity (megawatts [MW]) for all wind energy facilities in the US and Canada and provided information on 4,975 bird fatalities, of which we estimated 62.5% were small passerines comprising 156 species. For all wind energy facilities currently in operation, we estimated that about 134,000 to 230,000 small-passerine fatalities from collision with wind turbines occur annually, or 2.10 to 3.35 small birds/MW of installed capacity. When adjusted for species composition, this indicates that about 368,000 fatalities for all bird species are caused annually by collisions with wind turbines. Other human-related sources of bird deaths, (e.g., communication towers, buildings [including windows]), and domestic cats) have been estimated to kill millions to billions of birds each year. Compared to continent-wide population estimates, the cumulative mortality rate per year by species was highest for black-throated blue warbler and tree swallow; 0.043% of the entire population of each species was estimated to annually suffer mortality from collisions with turbines. For the eighteen species with the next highest values, this estimate ranged from 0.008% to 0.038%, much lower than rates attributed to collisions with communication towers (1.2% to 9.0% for top twenty species).

Small-scale wind disturbances observed by the MU radar during the passage of typhoon Kelly

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sato, Kaoru

1993-02-14

This paper describes small-scale wind disturbances associated with Typhoon Kelly (October 1987) that were observed by the MU radar, one of the MST (mesosphere, stratosphere, and troposphere) radars, for about 60 hours with fine time and height resolution. To elucidate the background of small-scale disturbances, synoptic-scale variation in atmospheric stability related to the typhoon structure during the observation is examined. When the typhoon passed near the MU radar site, the structure was no longer axisymmetric. There is deep convection only in north-northeast side of the typhoon while convection behind it is suppressed by a synoptic-scale cold air mass moving eastwardmore » to the west of the typhoon. A change in atmospheric stability over the radar site as indicated by echo power profiles is likely due to the passage of the sharp transition zone of convection. Strong small-scale wind disturbances were observed around the typhoon passage. The statistical characteristics are different before (BT) and after (AT) the typhoon passage, especially in frequency spectra of vertical wind fluctuations. The spectra for BT are unique compared with earlier studies of vertical winds observed by VHF radars. Another difference is dominance of a horizontal wind component with a vertical wavelength of about 3 km, observed only in AT. Further analyses are made of characteristics and vertical momentum fluxes for dominant disturbances. Some disturbances are generated to remove the momentum of cyclonic wind rotation of the typhoon. Deep convection, topographic effects in strong winds, and strong vertical shear of horizontal winds around an inversion layer are possible sources of the disturbances. Two monochromatic disturbances lasting for more than 10 h in the lower stratosphere observed in BT and AT are identified as inertio-gravity waves, by obtaining wave parameters consistent with all observed quantities. Both of the inertio-gravity waves propagate energy away from the

A summary of impacts of wind power integration on power system small-signal stability

NASA Astrophysics Data System (ADS)

Yan, Lei; Wang, Kewen

2017-05-01

Wind power has been increasingly integrated into power systems over the last few decades because of the global energy crisis and the pressure on environmental protection, and the stability of the system connected with wind power is becoming more prominent. This paper summaries the research status, achievements as well as deficiencies of the research on the impact of wind power integration on power system small-signal stability. In the end, the further research needed are discussed.

Aerodynamic tailoring of the Learjet Model 60 wing

NASA Technical Reports Server (NTRS)

Chandrasekharan, Reuben M.; Hawke, Veronica M.; Hinson, Michael L.; Kennelly, Robert A., Jr.; Madson, Michael D.

1993-01-01

The wing of the Learjet Model 60 was tailored for improved aerodynamic characteristics using the TRANAIR transonic full-potential computational fluid dynamics (CFD) code. A root leading edge glove and wing tip fairing were shaped to reduce shock strength, improve cruise drag and extend the buffet limit. The aerodynamic design was validated by wind tunnel test and flight test data.

Modeling circulation patterns induced by spatial cross-shore wind variability in a small-size coastal embayment

NASA Astrophysics Data System (ADS)

Cerralbo, Pablo; Espino, Manuel; Grifoll, Manel

2016-08-01

This contribution shows the importance of the cross-shore spatial wind variability in the water circulation in a small-sized micro-tidal bay. The hydrodynamic wind response at Alfacs Bay (Ebro River delta, NW Mediterranean Sea) is investigated with a numerical model (ROMS) supported by in situ observations. The wind variability observed in meteorological measurements is characterized with meteorological model (WRF) outputs. From the hydrodynamic simulations of the bay, the water circulation response is affected by the cross-shore wind variability, leading to water current structures not observed in the homogeneous-wind case. If the wind heterogeneity response is considered, the water exchange in the longitudinal direction increases significantly, reducing the water exchange time by around 20%. Wind resolutions half the size of the bay (in our case around 9 km) inhibit cross-shore wind variability, which significantly affects the resultant circulation pattern. The characteristic response is also investigated using idealized test cases. These results show how the wind curl contributes to the hydrodynamic response in shallow areas and promotes the exchange between the bay and the open sea. Negative wind curl is related to the formation of an anti-cyclonic gyre at the bay's mouth. Our results highlight the importance of considering appropriate wind resolution even in small-scale domains (such as bays or harbors) to characterize the hydrodynamics, with relevant implications in the water exchange time and the consequent water quality and ecological parameters.

Cost effectiveness of computer tailored and non-tailored smoking cessation letters in general practice: randomised controlled trial

PubMed Central

Lennox, A Scott; Osman, Liesl M; Reiter, Ehud; Robertson, Roma; Friend, James; McCann, Ian; Skatun, Diane; Donnan, Peter T

2001-01-01

cost effective than computer tailored letters or no letters. What is already known on this topicBrief opportunistic advice on stopping smoking that is given face to face by health professionals increases rates of cessation by 2-3%Intensive, expert-led interventions increase cessation rates by up to 20% or more but are expensive and reach only a small proportion of smokersWritten advice tailored to an individual's “stage of change” (intention to stop in a particular period of time) has been claimed to be as effective as intensive interventions, but previous studies of tailored written advice did not biochemically validate cessationWhat this paper addsA simple standard letter sent to patients of general practices that gave brief advice on stopping smoking increased the biochemically validated rate of cessation by 2%A letter tailored to the individual's “stage of change” was not more effective than the non-tailored standard letterAlthough the increase in cessation resulting from the non-tailored standard letter was small, this intervention was highly cost effective PMID:11397745

A Flight Dynamics Model for a Small Glider in Ambient Winds

NASA Technical Reports Server (NTRS)

Beeler, Scott C.; Moerder, Daniel D.; Cox, David E.

2003-01-01

In this paper we describe the equations of motion developed for a point-mass zero-thrust (gliding) aircraft model operating in an environment of spatially varying atmospheric winds. The wind effects are included as an integral part of the flight dynamics equations, and the model is controlled through the three aerodynamic control angles. Formulas for the aerodynamic coefficients for this model are constructed to include the effects of several different aspects contributing to the aerodynamic performance of the vehicle. Characteristic parameter values of the model are compared with those found in a different set of small glider simulations. We execute a set of example problems which solve the glider dynamics equations to find the aircraft trajectory given specified control inputs. The ambient wind conditions and glider characteristics are varied to compare the simulation results under these different circumstances.

A Flight Dynamics Model for a Small Glider in Ambient Winds

NASA Technical Reports Server (NTRS)

Beeler, Scott C.; Moerder, Daniel D.; Cox, David E.

2003-01-01

In this paper we describe the equations of motion developed for a point-mass zero-thrust (gliding) aircraft model operating in an environment of spatially varying atmospheric winds. The wind effects are included as an integral part of the flight dynamics equations, and the model is controlled through the three aerodynamic control angles. Formulas for the aerodynamic coefficients for this model are constructed to include the effects of several different aspects contributing to the aerodynamic performance of the vehicle. Characteristic parameter values of the model are compared with those found in a different set of small glider simulations. We execute a set of example problems which solve the glider dynamics equations to find aircraft trajectory given specified control inputs. The ambient wind conditions and glider characteristics are varied to compare the simulation results under these different circumstances.

Persistence Characteristics of Wind-Tunnel Pressure Signatures From Two Similar Models

NASA Technical Reports Server (NTRS)

Mack, Robert J.

2004-01-01

Pressure signatures generated by two sonic-boom wind-tunnel models and measured at Mach 2 are presented, analyzed, and discussed. The two wind-tunnel models differed in length and span by a factor of fourteen, but were similar in wing-body planform shape. The geometry of the larger model had been low-boom tailored to generate a flat top ground pressure signature, and the nacelles-off pressure signatures from this model became more flattop in shape as the model-probe separation distances increased from 0.94 to 4.4 span lengths. The geometry of the smaller model had not been low-boom tailored, yet its measured pressure signatures had non-N-wave shapes that persisted as model-probe separation distances increased from 26.0 to 104.2 span lengths. Since the overall planforms of the two wind-tunnel models were so similar, it was concluded that the shape-persistence trends in the pressure signatures of the smaller, non-low-boom tailored model would also be present at very large distances in the pressure signatures of the larger, low-boom-tailored model.

Tailoring Small IT Projects in the Project Planning Phase

ERIC Educational Resources Information Center

Mulhearn, Michael F.

2011-01-01

Project management (PM) and systems engineering (SE) are essential skills in information technology (IT). There is an abundance of information available detailing the comprehensive bodies of knowledge, standards, and best practices. Despite the volume of information, there is surprisingly little information about how to tailor PM and SE tasks for…

The extent of wind-mediated dispersal of small metazoans, focusing nematodes.

PubMed

Ptatscheck, Christoph; Gansfort, Birgit; Traunspurger, Walter

2018-05-01

Wind-mediated transport is an important mechanism in the dispersal of small metazoans. Yet, concrete dispersal rates have hardly been examined. Here we present the results of an one-year field experiment investigating the composition and dispersal rates of aeroplankton. To gain insights into the dynamics of dispersal at the species level, we focused on nematodes, worldwide the most common metazoan taxon. Among the six taxa collected in this study (nematodes, rotifers, collembolans, tardigrades, mites, and thrips), nematodes had the highest dispersal rates (up to >3000 individuals m -2 in 4 weeks, 27 species identified) and represented >44% of aeroplankton. Only living nematodes, and no propagules, were dispersed. All taxa had a higher dispersal potential in environments linked to the source habitat, evidenced by the much higher deposition of organisms in funnels placed on the ground than on the rooftop of a ten-story building. Nematodes under conditions of high humidity and wind speed had the highest dispersal rates, while increasing temperatures and dryness had a significantly positive impact on the wind drift of mites and thrips. The results indicated that wind dispersal over long distances is possible. The notable organismal input by wind dispersal may contribute to biodiversity and ecosystem functions.

Development and testing of vortex generators for small horizontal axis wind turbines

NASA Technical Reports Server (NTRS)

Gyatt, G. W.

1986-01-01

Vortex generators (VGs) for a small (32 ft diameter) horizontal axis wind turbine, the Carter Model 25, have been developed and tested. Arrays of VGs in a counterrotating arrangement were tested on the inbound half-span, outboard half-span, and on the entire blade. VG pairs had their centerlines spaced at a distance of 15% of blade chord, with a spanwise width of 10% of blade chord. Each VG had a length/height ratio of 4, with a height of between 0.5% and 1.0% of the blade chord. Tests were made with roughness strips to determine whether VGs alleviated the sensitivity of some turbines to an accumulation of bugs and dirt on the leading edge. Field test data showed that VGs increased power output up to 20% at wind speeds above 10 m/s with only a small (less than 4%) performance penalty at lower speeds. The VGs on the outboard span of the blade were more effective than those on inner sections. For the case of full span coverage, the energy yearly output increased almost 6% at a site with a mean wind speed of 16 mph. The VGs did reduce the performance loss caused by leading edge roughness. An increase in blade pitch angle has an effect on the power curve similar to the addition of VGs. VGs alleviate the sensitivity of wind turbine rotors to leading edge roughness caused by bugs and drift.

The effect of wind on the dispersal of a tropical small river plume

NASA Astrophysics Data System (ADS)

Zhao, Junpeng; Gong, Wenping; Shen, Jian

2018-03-01

Wanquan River is a small river located in Hainan, a tropical island in China. As the third largest river in Hainan, the river plume plays an important role in the regional terrigenous mass transport, coastal circulation, and the coral reef's ecosystem. Studies have shown that wind forcings significantly influence river plume dynamics. In this study, wind effects on the dispersal of the river plume and freshwater transport were examined numerically using a calibrated, unstructured, finite volume numerical model (FVCOM). Both wind direction and magnitude were determined to influence plume dispersal. Northeasterly (downwelling-favorable) winds drove freshwater down-shelf while southeasterly (onshore) winds drove water up-shelf (in the sense of Kelvin wave propagation), and were confined near the coast. Southwesterly (upwelling-favorable) and north-westerly (offshore) winds transport more freshwater offshore. The transport flux is decomposed into an advection, a vertical shear, and an oscillatory component. The advection flux dominates the freshwater transport in the coastal area and the vertical shear flux is dominant in the offshore area. For the upwelling-favorable wind, the freshwater transport becomes more controlled by the advection transport with an increase in wind stress, due to enhanced vertical mixing. The relative importance of wind forcing and buoyancy force was investigated. It was found that, when the Wedderburn number is larger than one, the plume was dominated by wind forcing, although the importance of wind varies in different parts of the plume. The water column stratification decreased as a whole under the prevailing southwesterly wind, with the exception of the up-shelf and offshore areas.

Smart structure for small wind turbine blade

NASA Astrophysics Data System (ADS)

Supeni, E. E.; Epaarachchi, J. A.; Islam, M. M.; Lau, K. T.

2013-08-01

Wind energy is seen as a viable alternative energy option for future energy demand. The blades of wind turbines are generally regarded as the most critical component of the wind turbine system. Ultimately, the blades act as the prime mover of the whole system which interacts with the wind flow during the production of energy. During wind turbine operation the wind loading cause the deflection of the wind turbine blade which can be significant and affect the turbine efficiency. Such a deflection in wind blade not only will result in lower performance in electrical power generation but also increase of material degradation due high fatigue life and can significantly shorten the longevity for the wind turbine material. In harnessing stiffness of the blade will contribute massive weight factor and consequently excessive bending moment. To overcome this excessive deflection due to wind loading on the blade, it is feasible to use shape memory alloy (SMA) wires which has ability take the blade back to its optimal operational shape. This paper details analytical and experimental work being carried out to minimize blade flapping deflection using SMA.

An assessment of non-volant terrestrial vertebrates response to wind farms--a study of small mammals.

PubMed

Łopucki, Rafał; Mróz, Iwona

2016-02-01

The majority of studies on the effects of wind energy development on wildlife have been focused on birds and bats, whereas knowledge of the response of terrestrial, non-flying vertebrates is very scarce. In this paper, the impact of three functioning wind farms on terrestrial small mammal communities (rodents and shrews) and the population parameters of the most abundant species were studied. The study was carried out in southeastern Poland within the foothills of the Outer Western Carpathians. Small mammals were captured at 12 sites around wind turbines and at 12 control sites. In total, from 1200 trap-days, 885 individuals of 14 studied mammal species were captured. There was no difference in the characteristics of communities of small mammals near wind turbines and within control sites; i.e. these types of sites were inhabited by a similar number of species of similar abundance, similar species composition, species diversity (H' index) and species evenness (J') (Pielou's index). For the two species with the highest proportion in the communities (Apodemus agrarius and Microtus arvalis), the parameters of their populations (mean body mass, sex ratio, the proportion of adult individuals and the proportion of reproductive female) were analysed. In both species, none of the analysed parameters differed significantly between sites in the vicinity of turbines and control sites. For future studies on the impact of wind turbines on small terrestrial mammals in different geographical areas and different species communities, we recommend the method of paired 'turbine-control sites' as appropriate for animal species with pronounced fluctuations in population numbers.

Small UAS-Based Wind Feature Identification System Part 1: Integration and Validation

PubMed Central

Rodriguez Salazar, Leopoldo; Cobano, Jose A.; Ollero, Anibal

2016-01-01

This paper presents a system for identification of wind features, such as gusts and wind shear. These are of particular interest in the context of energy-efficient navigation of Small Unmanned Aerial Systems (UAS). The proposed system generates real-time wind vector estimates and a novel algorithm to generate wind field predictions. Estimations are based on the integration of an off-the-shelf navigation system and airspeed readings in a so-called direct approach. Wind predictions use atmospheric models to characterize the wind field with different statistical analyses. During the prediction stage, the system is able to incorporate, in a big-data approach, wind measurements from previous flights in order to enhance the approximations. Wind estimates are classified and fitted into a Weibull probability density function. A Genetic Algorithm (GA) is utilized to determine the shaping and scale parameters of the distribution, which are employed to determine the most probable wind speed at a certain position. The system uses this information to characterize a wind shear or a discrete gust and also utilizes a Gaussian Process regression to characterize continuous gusts. The knowledge of the wind features is crucial for computing energy-efficient trajectories with low cost and payload. Therefore, the system provides a solution that does not require any additional sensors. The system architecture presents a modular decentralized approach, in which the main parts of the system are separated in modules and the exchange of information is managed by a communication handler to enhance upgradeability and maintainability. Validation is done providing preliminary results of both simulations and Software-In-The-Loop testing. Telemetry data collected from real flights, performed in the Seville Metropolitan Area in Andalusia (Spain), was used for testing. Results show that wind estimation and predictions can be calculated at 1 Hz and a wind map can be updated at 0.4 Hz. Predictions

Small UAS-Based Wind Feature Identification System Part 1: Integration and Validation.

PubMed

Rodriguez Salazar, Leopoldo; Cobano, Jose A; Ollero, Anibal

2016-12-23

This paper presents a system for identification of wind features, such as gusts and wind shear. These are of particular interest in the context of energy-efficient navigation of Small Unmanned Aerial Systems (UAS). The proposed system generates real-time wind vector estimates and a novel algorithm to generate wind field predictions. Estimations are based on the integration of an off-the-shelf navigation system and airspeed readings in a so-called direct approach. Wind predictions use atmospheric models to characterize the wind field with different statistical analyses. During the prediction stage, the system is able to incorporate, in a big-data approach, wind measurements from previous flights in order to enhance the approximations. Wind estimates are classified and fitted into a Weibull probability density function. A Genetic Algorithm (GA) is utilized to determine the shaping and scale parameters of the distribution, which are employed to determine the most probable wind speed at a certain position. The system uses this information to characterize a wind shear or a discrete gust and also utilizes a Gaussian Process regression to characterize continuous gusts. The knowledge of the wind features is crucial for computing energy-efficient trajectories with low cost and payload. Therefore, the system provides a solution that does not require any additional sensors. The system architecture presents a modular decentralized approach, in which the main parts of the system are separated in modules and the exchange of information is managed by a communication handler to enhance upgradeability and maintainability. Validation is done providing preliminary results of both simulations and Software-In-The-Loop testing. Telemetry data collected from real flights, performed in the Seville Metropolitan Area in Andalusia (Spain), was used for testing. Results show that wind estimation and predictions can be calculated at 1 Hz and a wind map can be updated at 0.4 Hz . Predictions

Aerodynamic study of a small wind turbine with emphasis on laminar and transition flows

NASA Astrophysics Data System (ADS)

Niculescu, M. L.; Cojocaru, M. G.; Crunteanu, D. E.

2016-06-01

The wind energy is huge but unfortunately, wind turbines capture only a little part of this enormous green energy. Furthermore, it is impossible to put multi megawatt wind turbines in the cities because they generate a lot of noise and discomfort. Instead, it is possible to install small Darrieus and horizontal-axis wind turbines with low tip speed ratios in order to mitigate the noise as much as possible. Unfortunately, the flow around this wind turbine is quite complex because the run at low Reynolds numbers. Therefore, this flow is usually a mixture of laminar, transition and laminar regimes with bubble laminar separation that is very difficult to simulate from the numerical point of view. Usually, transition and laminar regimes with bubble laminar separation are ignored. For this reason, this paper deals with laminar and transition flows in order to provide some brightness in this field.

Distributed Wind Research | Wind | NREL

Science.gov Websites

evaluation, and improve wind turbine and wind power plant performance. A photo of a snowy road leading to a single wind turbine surrounded by snow-covered pine trees against blue sky. Capabilities NREL's power plant and small wind turbine development. Algorithms and programs exist for simulating, designing

Systems Engineering 2013 Workshop | Wind | NREL

Science.gov Websites

through the integration of manufacturing requirements into the aerodynamic design of blades was used to Towards Optimal Aeroelastic Tailoring of Wind Turbine Blades Curran Crawford, Ph.D. University of Victoria

Small-scale Pressure-balanced Structures Driven by Oblique Slow Mode Waves Measured in the Solar Wind

NASA Astrophysics Data System (ADS)

Yao, Shuo; He, J.-S.; Tu, C.-Y.; Wang, L.-H.; Marsch, E.

2013-09-01

Recently, small-scale pressure-balanced structures (PBSs) were identified in the solar wind, but their formation mechanism remains unclear. This work aims to reveal the dependence of the properties of small-scale PBSs on the background magnetic field (B 0) direction and thus to corroborate the in situ mechanism that forms them. We analyze the plasma and magnetic field data obtained by WIND in the quiet solar wind at 1 AU. First, we use a developed moving-average method to obtain B 0(s, t) for every temporal scale (s) at each time moment (t). By wavelet cross-coherence analysis, we obtain the correlation coefficients between the thermal pressure P th and the magnetic pressure P B, distributing against the temporal scale and the angle θxB between B 0(s, t) and Geocentric Solar Ecliptic coordinates (GSE)-x. We note that the angle coverage of a PBS decreases with shorter temporal scale, but the occurrence of the PBSs is independent of θxB. Suspecting that the isolated small PBSs are formed by compressive waves in situ, we continue this study by testing the wave modes forming a small-scale PBS with B 0(s, t) quasi-parallel to GSE-x. As a result, we identify that the cross-helicity and the compressibility attain values for a slow mode from theoretical calculations. The wave vector is derived from minimum variance analysis. Besides, the proton temperatures obey T < T ∥ derived from the velocity distribution functions, excluding a mirror mode, which is the other candidate for the formation of PBSs in situ. Thus, a small-scale PBS is shown to be driven by oblique, slow-mode waves in the solar wind.

A Comprehensive Structural Study of Offshore Wind Turbine Foundation and Non-Model Based Damage Detection using Effective Mass with Application to Small Components/ Cables and a Truss Wind Turbine Tower

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Scott A.

This research has two areas of focus. The first area is to investigate offshore wind turbine (OWT) designs, for use in the Maryland offshore wind area (MOWA), using intensive modeling techniques. The second focus area is to investigate a way to detect damage in wind turbine towers and small electrical components.

Sistemas Eolicos Pequenos para Generacion de Electridad (Spanish version of Small Wind Electric Systems: A U.S. Consumer's Guide) (in Spanish)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2005-07-01

This Spanish version of the popular Small Wind Electric Systems: A U.S. Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system tomore » the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.« less

Analysis of conditions favourable for small vertical axis wind turbines between building passages in urban areas of Sweden

NASA Astrophysics Data System (ADS)

Awan, Muhammad Rizwan; Riaz, Fahid; Nabi, Zahid

2017-05-01

This paper presents the analysis of installing the vertical axis wind turbines between the building passages on an island in Stockholm, Sweden. Based on the idea of wind speed amplification due to the venture effect in passages, practical measurements were carried out to study the wind profile for a range of passage widths in parallel building passages. Highest increment in wind speed was observed in building passages located on the periphery of sland as wind enters from free field. Wind mapping was performed in the island to choose the most favourable location to install the vertical axis wind turbines (VAWT). Using the annual wind speed data for location and measured amplification factor, energy potential of the street was calculated. This analysis verified that small vertical axis wind turbines can be installed in the passage centre line provided that enough space is provided for traffic and passengers.

Aerodynamic performance of a small vertical axis wind turbine using an overset grid method

NASA Astrophysics Data System (ADS)

Bangga, Galih; Solichin, Mochammad; Daman, Aida; Sa'adiyah, Devy; Dessoky, Amgad; Lutz, Thorsten

2017-08-01

The present paper aims to asses the aerodynamic performance of a small vertical axis wind turbine operating at a small wind speed of 5 m/s for 6 different tip speed ratios (λ=2-7). The turbine consists of two blades constructed using the NACA 0015 airfoil. The study is carried out using computational fluid dynamics (CFD) methods employing an overset grid approach. The (URANS) SST k - ω is used as the turbulence model. For the preliminary study, simulations of the NACA 0015 under static conditions for a broad range of angle of attack and a rotating two-bladed VAWT are carried out. The results are compared with available measurement data and a good agreement is obtained. The simulations demonstrate that the maximum power coefficient attained is 0.45 for λ=4. The aerodynamic loads hysteresis are presented showing that the dynamic stall effect decreases with λ.

Wind variability and sheltering effects on measurements and modeling of air-water exchange for a small lake

NASA Astrophysics Data System (ADS)

Markfort, Corey D.; Resseger, Emily; Porté-Agel, Fernando; Stefan, Heinz

2014-05-01

Lakes with a surface area of less than 10 km2 account for over 50% of the global cumulative lake surface water area, and make up more than 99% of the total number of global lakes, ponds, and wetlands. Within the boreal regions as well as some temperate and tropical areas, a significant proportion of land cover is characterized by lakes or wetlands, which can have a dramatic effect on land-atmosphere fluxes as well as the local and regional energy budget. Many of these small water bodies are surrounded by complex terrain and forest, which cause the wind blowing over a small lake or wetland to be highly variable. Wind mixing of the lake surface layer affects thermal stratification, surface temperature and air-water gas transfer, e.g. O2, CO2, and CH4. As the wind blows from the land to the lake, wake turbulence behind trees and other shoreline obstacles leads to a recirculation zone and enhanced turbulence. This wake flow results in the delay of the development of wind shear stress on the lake surface, and the fetch required for surface shear stress to fully develop may be ~O(1 km). Interpretation of wind measurements made on the lake is hampered by the unknown effect of wake turbulence. We present field measurements designed to quantify wind variability over a sheltered lake. The wind data and water column temperature profiles are used to evaluate a new method to quantify wind sheltering of lakes that takes into account lake size, shape and the surrounding landscape features. The model is validated against field data for 36 Minnesota lakes. Effects of non-uniform sheltering and lake shape are also demonstrated. The effects of wind sheltering must be included in lake models to determine the effect of wind-derived energy inputs on lake stratification, surface gas transfer, lake water quality, and fish habitat. These effects are also important for correctly modeling momentum, heat, moisture and trace gas flux to the atmosphere.

Analyzing the requirements for mass production of small wind turbine generators

NASA Astrophysics Data System (ADS)

Anuskiewicz, T.; Asmussen, J.; Frankenfield, O.

Mass producibility of small wind turbine generators to give manufacturers design and cost data for profitable production operations is discussed. A 15 kW wind turbine generator for production in annual volumes from 1,000 to 50,000 units is discussed. Methodology to cost the systems effectively is explained. The process estimate sequence followed is outlined with emphasis on the process estimate sheets compiled for each component and subsystem. These data enabled analysts to develop cost breakdown profiles crucial in manufacturing decision-making. The appraisal also led to various design recommendations including replacement of aluminum towers with cost effective carbon steel towers. Extensive cost information is supplied in tables covering subassemblies, capital requirements, and levelized energy costs. The physical layout of the plant is depicted to guide manufacturers in taking advantage of the growing business opportunity now offered in conjunction with the national need for energy development.

Wind Fins: Novel Lower-Cost Wind Power System

DOE Office of Scientific and Technical Information (OSTI.GOV)

David C. Morris; Dr. Will D. Swearingen

This project evaluated the technical feasibility of converting energy from the wind with a novel “wind fin” approach. This patent-pending technology has three major components: (1) a mast, (2) a vertical, hinged wind structure or fin, and (3) a power takeoff system. The wing structure responds to the wind with an oscillating motion, generating power. The overall project goal was to determine the basic technical feasibility of the wind fin technology. Specific objectives were the following: (1) to determine the wind energy-conversion performance of the wind fin and the degree to which its performance could be enhanced through basic designmore » improvements; (2) to determine how best to design the wind fin system to survive extreme winds; (3) to determine the cost-effectiveness of the best wind fin designs compared to state-of-the-art wind turbines; and (4) to develop conclusions about the overall technical feasibility of the wind fin system. Project work involved extensive computer modeling, wind-tunnel testing with small models, and testing of bench-scale models in a wind tunnel and outdoors in the wind. This project determined that the wind fin approach is technically feasible and likely to be commercially viable. Project results suggest that this new technology has the potential to harvest wind energy at approximately half the system cost of wind turbines in the 10kW range. Overall, the project demonstrated that the wind fin technology has the potential to increase the economic viability of small wind-power generation. In addition, it has the potential to eliminate lethality to birds and bats, overcome public objections to the aesthetics of wind-power machines, and significantly expand wind-power’s contribution to the national energy supply.« less

Demonstrating a new framework for the comparison of environmental impacts from small- and large-scale hydropower and wind power projects.

PubMed

Bakken, Tor Haakon; Aase, Anne Guri; Hagen, Dagmar; Sundt, Håkon; Barton, David N; Lujala, Päivi

2014-07-01

Climate change and the needed reductions in the use of fossil fuels call for the development of renewable energy sources. However, renewable energy production, such as hydropower (both small- and large-scale) and wind power have adverse impacts on the local environment by causing reductions in biodiversity and loss of habitats and species. This paper compares the environmental impacts of many small-scale hydropower plants with a few large-scale hydropower projects and one wind power farm, based on the same set of environmental parameters; land occupation, reduction in wilderness areas (INON), visibility and impacts on red-listed species. Our basis for comparison was similar energy volumes produced, without considering the quality of the energy services provided. The results show that small-scale hydropower performs less favourably in all parameters except land occupation. The land occupation of large hydropower and wind power is in the range of 45-50 m(2)/MWh, which is more than two times larger than the small-scale hydropower, where the large land occupation for large hydropower is explained by the extent of the reservoirs. On all the three other parameters small-scale hydropower performs more than two times worse than both large hydropower and wind power. Wind power compares similarly to large-scale hydropower regarding land occupation, much better on the reduction in INON areas, and in the same range regarding red-listed species. Our results demonstrate that the selected four parameters provide a basis for further development of a fair and consistent comparison of impacts between the analysed renewable technologies. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Predicting wind-driven waves in small reservoirs

USDA-ARS?s Scientific Manuscript database

The earthen levees commonly used for irrigation reservoirs are subjected to significant embankment erosion due to wind-generated waves. The design of bank protection measures relies on adequate prediction of wave characteristics based on wind conditions and fetch length. Current formulations are ba...

Producing Turbulent Wind Tunnel Inflows Relevant to Wind Turbines using an Active Grid

NASA Astrophysics Data System (ADS)

Rumple, Christopher; Welch, Matthew; Naughton, Jonathan

2017-11-01

The rise of industries like wind energy have provided motivation for generating realistic turbulent inflows in wind tunnels. Facilities with the ability to produce such inflows can study the interaction between the inflow turbulence and the flow of interest such as a wind turbine wake. An active grid - a system of actively driven elements - has gained increasing acceptance in turbulence research over the last 20 years. The ability to tailor the inflow turbulence quantities (e.g. turbulence intensities, integral length scale, and turbulence spectrum) is a driving reason for the growing use of active grids. An active grid with 40 independent axes located within the forward contraction of a low speed wind tunnel is used to explore the range of turbulent inflows possible using hot-wire anemometry to characterize the turbulence. Motor control algorithms (i.e. user waveform inputs) used to produce various turbulent inflows will be presented. Wind data available from meteorological towers are used to develop relevant inflows for wind turbines to demonstrate the usefulness of the active grid. This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Award # DE-SC0012671.

Reindeer habitat use in relation to two small wind farms, during preconstruction, construction, and operation.

PubMed

Skarin, Anna; Alam, Moudud

2017-06-01

Worldwide there is a rush toward wind power development and its associated infrastructure. In Fennoscandia, large-scale wind farms comprising several hundred windmills are currently built in important grazing ranges used for Sámi reindeer husbandry. In this study, reindeer habitat use was assessed using reindeer fecal pellet group counts in relation to two relatively small wind farms, with 8 and 10 turbines, respectively. In 2009, 1,315 15-m 2 plots were established and pellet groups were counted and cleaned from the plots. This was repeated once a year in May, during preconstruction, construction, and operation of the wind farms, covering 6 years (2009-2014) of reindeer habitat use in the area. We modeled the presence/absence of any pellets in a plot at both the local (wind farm site) and regional (reindeer calving to autumn range) scale with a hierarchical logistic regression, where spatial correlation was accounted for via random effects, using vegetation type, and the interaction between distance to wind turbine and time period as predictor variables. Our results revealed an absolute reduction in pellet groups by 66% and 86% around each wind farm, respectively, at local scale and by 61% at regional scale during the operation phase compared to the preconstruction phase. At the regional, scale habitat use declined close to the turbines in the same comparison. However, at the local scale, we observed increased habitat use close to the wind turbines at one of the wind farms during the operation phase. This may be explained by continued use of an important migration route close to the wind farm. The reduced use at the regional scale nevertheless suggests that there may be an overall avoidance of both wind farms during operation, but further studies of reindeer movement and behavior are needed to gain a better understanding of the mechanisms behind this suggested avoidance.

Small-tip fast recovery imaging using non-slice-selective tailored tip-up pulses and RF-spoiling

PubMed Central

Nielsen, Jon-Fredrik; Yoon, Daehyun; Noll, Douglas C.

2012-01-01

Small-tip fast recovery (STFR) imaging is a new steady-state imaging sequence that is a potential alternative to balanced steady-state free precession (bSSFP). Under ideal imaging conditions, STFR may provide comparable signal-to-noise ratio (SNR) and image contrast as bSSFP, but without signal variations due to resonance offset. STFR relies on a tailored “tip-up”, or “fast recovery”, RF pulse to align the spins with the longitudinal axis after each data readout segment. The design of the tip-up pulse is based on the acquisition of a separate off-resonance (B0) map. Unfortunately, the design of fast (a few ms) slice- or slab-selective RF pulses that accurately tailor the excitation pattern to the local B0 inhomogeneity over the entire imaging volume remains a challenging and unsolved problem. We introduce a novel implementation of STFR imaging based on non-slice-selective tip-up pulses, which simplifies the RF design problem significantly. Out-of-slice magnetization pathways are suppressed using RF-spoiling. Brain images obtained with this technique show excellent gray/white matter contrast, and point to the possibility of rapid steady-state T2/T1-weighted imaging with intrinsic suppression of cerebrospinal fluid, through-plane vessel signal, and off-resonance artifacts. In the future we expect STFR imaging to benefit significantly from parallel excitation hardware and high-order gradient shim systems. PMID:22511367

Load attenuating passively adaptive wind turbine blade

DOEpatents

Veers, Paul S.; Lobitz, Donald W.

2003-01-07

A method and apparatus for improving wind turbine performance by alleviating loads and controlling the rotor. The invention employs the use of a passively adaptive blade that senses the wind velocity or rotational speed, and accordingly modifies its aerodynamic configuration. The invention exploits the load mitigation prospects of a blade that twists toward feather as it bends. The invention includes passively adaptive wind turbine rotors or blades with currently preferred power control features. The apparatus is a composite fiber horizontal axis wind-turbine blade, in which a substantial majority of fibers in the blade skin are inclined at angles of between 15 and 30 degrees to the axis of the blade, to produces passive adaptive aeroelastic tailoring (bend-twist coupling) to alleviate loading without unduly jeopardizing performance.

Load attenuating passively adaptive wind turbine blade

DOEpatents

Veers, Paul S.; Lobitz, Donald W.

2003-01-01

A method and apparatus for improving wind turbine performance by alleviating loads and controlling the rotor. The invention employs the use of a passively adaptive blade that senses the wind velocity or rotational speed, and accordingly modifies its aerodynamic configuration. The invention exploits the load mitigation prospects of a blade that twists toward feather as it bends. The invention includes passively adaptive wind turbine rotors or blades with currently preferred power control features. The apparatus is a composite fiber horizontal axis wind-turbine blade, in which a substantial majority of fibers in the blade skin are inclined at angles of between 15 and 30 degrees to the axis of the blade, to produces passive adaptive aeroelastic tailoring (bend-twist coupling) to alleviate loading without unduly jeopardizing performance.

Mechanistic Drifting Forecast Model for A Small Semi-Submersible Drifter Under Tide-Wind-Wave Conditions

NASA Astrophysics Data System (ADS)

Zhang, Wei-Na; Huang, Hui-ming; Wang, Yi-gang; Chen, Da-ke; Zhang, lin

2018-03-01

Understanding the drifting motion of a small semi-submersible drifter is of vital importance regarding monitoring surface currents and the floating pollutants in coastal regions. This work addresses this issue by establishing a mechanistic drifting forecast model based on kinetic analysis. Taking tide-wind-wave into consideration, the forecast model is validated against in situ drifting experiment in the Radial Sand Ridges. Model results show good performance with respect to the measured drifting features, characterized by migrating back and forth twice a day with daily downwind displacements. Trajectory models are used to evaluate the influence of the individual hydrodynamic forcing. The tidal current is the fundamental dynamic condition in the Radial Sand Ridges and has the greatest impact on the drifting distance. However, it loses its leading position in the field of the daily displacement of the used drifter. The simulations reveal that different hydrodynamic forces dominate the daily displacement of the used drifter at different wind scales. The wave-induced mass transport has the greatest influence on the daily displacement at Beaufort wind scale 5-6; while wind drag contributes mostly at wind scale 2-4.

The aeolian wind tunnel

NASA Technical Reports Server (NTRS)

Iversen, J. D.

1991-01-01

The aeolian wind tunnel is a special case of a larger subset of the wind tunnel family which is designed to simulate the atmospheric surface layer winds to small scale (a member of this larger subset is usually called an atmospheric boundary layer wind tunnel or environmental wind tunnel). The atmospheric boundary layer wind tunnel is designed to simulate, as closely as possible, the mean velocity and turbulence that occur naturally in the atmospheric boundary layer (defined as the lowest portion of the atmosphere, of the order of 500 m, in which the winds are most greatly affected by surface roughness and topography). The aeolian wind tunnel is used for two purposes: to simulate the physics of the saltation process and to model at small scale the erosional and depositional processes associated with topographic surface features. For purposes of studying aeolian effects on the surface of Mars and Venus as well as on Earth, the aeolian wind tunnel continues to prove to be a useful tool for estimating wind speeds necessary to move small particles on the three planets as well as to determine the effects of topography on the evolution of aeolian features such as wind streaks and dune patterns.

Crossed, Small-Deflection Energy Analyzer for Wind/Temperature Spectrometer

NASA Technical Reports Server (NTRS)

Herrero, Federico A.; Finne, Theodore T.

2010-01-01

Determination of neutral winds and ion drifts in low-Earth-orbit missions requires measurements of the angular and energy distributions of the flux of neutrals and ions entering the satellite from the ram direction. The magnitude and direction of the neutral-wind (or ion-drift) determine the location of the maximum in the angular distribution of the flux. Knowledge of the angle of maximum flux with respect to satellite coordinates (pointing) is essential to determine the wind (or ion-drift) vector. The crossed Small-Deflection Energy Analyzer (SDEA) spectrometer (see Figure 1) occupies minimal volume and consumes minimal power. Designed for upper atmosphere/ionosphere investigations at Earth altitudes above 100 km, the spectrometer operates by detecting the angular and energy distributions of neutral atoms/molecules and ions in two mutually perpendicular planes. In this configuration, the two detection planes actually cross at the spectrometer center. It is possible to merge two SDEAs so they share a common optical axis and alternate measurements between two perpendicular planes, and reduce the number of ion sources from two to one. This minimizes the volume and footprint significantly and reduces the ion source power by a factor of two. The area of the entrance aperture affects the number of ions detected/second and also determines the energy resolution. Thermionic emitters require heater power of about 100 mW to produce 1 mA of electron beam current. Typically, electron energy is about 100 eV and requires a 100-V supply for electron acceleration to supply an additional 100 mW of power. Thus, ion source power is at most 200 mW. If two ion sources were to be used, the ion source power would be, at most, 400 mW. Detector power, deflection voltage power, and microcontroller and other functions require less than 150 mW. A WTS (wind/ temperature spectrometer) with two separate optical axes would consume about 650 mW, while the crossed SDEA described here consumes about

Design and wind tunnel tests of winglets on a DC-10 wing

NASA Technical Reports Server (NTRS)

Gilkey, R. D.

1979-01-01

Results are presented of a wind tunnel test utilizing a 4.7 percent scale semi-span model in the Langley Research Center 8-foot transonic pressure wind tunnel to establish the cruise drag improvement potential of winglets as applied to the DC-10 wide body transport aircraft. Winglets were investigated on both the DC-10 Series 10 (domestic) and 30/40 (intercontinental) configurations and compared with the Series 30/40 configuration. The results of the investigation confirm that for the DC-10 winglets provide approximately twice the cruise drag reduction of wing-tip extensions for about the same increase in bending moment at the wing fuselage juncture. Furthermore, the winglet configurations achieved drag improvements which were in close agreement to analytical estimates. It was observed that relatively small changes in wing-winglet tailoring effected large improvements in drag and visual flow characteristics. All final winglet configurations exhibited visual flow characteristics on the wing and winglets

Validation of Design and Analysis Techniques of Tailored Composite Structures

NASA Technical Reports Server (NTRS)

Jegley, Dawn C. (Technical Monitor); Wijayratne, Dulnath D.

2004-01-01

Aeroelasticity is the relationship between the elasticity of an aircraft structure and its aerodynamics. This relationship can cause instabilities such as flutter in a wing. Engineers have long studied aeroelasticity to ensure such instabilities do not become a problem within normal operating conditions. In recent decades structural tailoring has been used to take advantage of aeroelasticity. It is possible to tailor an aircraft structure to respond favorably to multiple different flight regimes such as takeoff, landing, cruise, 2-g pull up, etc. Structures can be designed so that these responses provide an aerodynamic advantage. This research investigates the ability to design and analyze tailored structures made from filamentary composites. Specifically the accuracy of tailored composite analysis must be verified if this design technique is to become feasible. To pursue this idea, a validation experiment has been performed on a small-scale filamentary composite wing box. The box is tailored such that its cover panels induce a global bend-twist coupling under an applied load. Two types of analysis were chosen for the experiment. The first is a closed form analysis based on a theoretical model of a single cell tailored box beam and the second is a finite element analysis. The predicted results are compared with the measured data to validate the analyses. The comparison of results show that the finite element analysis is capable of predicting displacements and strains to within 10% on the small-scale structure. The closed form code is consistently able to predict the wing box bending to 25% of the measured value. This error is expected due to simplifying assumptions in the closed form analysis. Differences between the closed form code representation and the wing box specimen caused large errors in the twist prediction. The closed form analysis prediction of twist has not been validated from this test.

Magnetic Turbulence, Fast Magnetic Field line Diffusion and Small Magnetic Structures in the Solar Wind

NASA Astrophysics Data System (ADS)

Zimbardo, G.; Pommois, P.; Veltri, P.

2003-09-01

The influence of magnetic turbulence on magnetic field line diffusion has been known since the early days of space and plasma physics. However, the importance of ``stochastic diffusion'' for energetic particles has been challenged on the basis of the fact that sharp gradients of either energetic particles or ion composition are often observed in the solar wind. Here we show that fast transverse field line and particle diffusion can coexist with small magnetic structures, sharp gradients, and with long lived magnetic flux tubes. We show, by means of a numerical realization of three dimensional magnetic turbulence and by use of the concepts of deterministic chaos and turbulent transport, that turbulent diffusion is different from Gaussian diffusion, and that transport can be inhomogeneous even if turbulence homogeneously fills the heliosphere. Several diagnostics of field line transport and flux tube evolution are shown, and the size of small magnetic structures in the solar wind, like gradient scales and flux tube thickness, are estimated and compared to the observations.

Transient flows of the solar wind associated with small-scale solar activity in solar minimum

NASA Astrophysics Data System (ADS)

Slemzin, Vladimir; Veselovsky, Igor; Kuzin, Sergey; Gburek, Szymon; Ulyanov, Artyom; Kirichenko, Alexey; Shugay, Yulia; Goryaev, Farid

The data obtained by the modern high sensitive EUV-XUV telescopes and photometers such as CORONAS-Photon/TESIS and SPHINX, STEREO/EUVI, PROBA2/SWAP, SDO/AIA provide good possibilities for studying small-scale solar activity (SSA), which is supposed to play an important role in heating of the corona and producing transient flows of the solar wind. During the recent unusually weak solar minimum, a large number of SSA events, such as week solar flares, small CMEs and CME-like flows were observed and recorded in the databases of flares (STEREO, SWAP, SPHINX) and CMEs (LASCO, CACTUS). On the other hand, the solar wind data obtained in this period by ACE, Wind, STEREO contain signatures of transient ICME-like structures which have shorter duration (<10h), weaker magnetic field strength (<10 nT) and lower proton temperature than usual ICMEs. To verify the assumption that ICME-like transients may be associated with the SSA events we investigated the number of weak flares of C-class and lower detected by SPHINX in 2009 and STEREO/EUVI in 2010. The flares were classified on temperature and emission measure using the diagnostic means of SPHINX and Hinode/EIS and were confronted with the parameters of the solar wind (velocity, density, ion composition and temperature, magnetic field, pitch angle distribution of the suprathermal electrons). The outflows of plasma associated with the flares were identified by their coronal signatures - CMEs (only in few cases) and dimmings. It was found that the mean parameters of the solar wind projected to the source surface for the times of the studied flares were typical for the ICME-like transients. The results support the suggestion that weak flares can be indicators of sources of transient plasma flows contributing to the slow solar wind at solar minimum, although these flows may be too weak to be considered as separate CMEs and ICMEs. The research leading to these results has received funding from the European Union’s Seventh Programme

Power Spectra, Power Law Exponents, and Anisotropy of Solar Wind Turbulence at Small Scales

NASA Technical Reports Server (NTRS)

Podesta, J. J.; Roberts, D. A.; Goldstein, M. L.

2006-01-01

The Wind spacecraft provides simultaneous solar wind velocity and magnetic field measurements with 3- second time resolution, roughly an order of magnitude faster than previous measurements, enabling the small scale features of solar wind turbulence to be studied in unprecedented detail. Almost the entire inertial range can now be explored (the inertial range extends from approximately 1 to 10(exp 3) seconds in the spacecraft frame) although the dissipation range of the velocity fluctuations is still out of reach. Improved measurements of solar wind turbulence spectra at 1 AU in the ecliptic plane are presented including spectra of the energy and cross-helicity, the magnetic and kinetic energies, the Alfven ratio, the normalized cross-helicity, and the Elsasser ratio. Some recent observations and theoretical challenges are discussed including the observation that the velocity and magnetic field spectra often show different power law exponents with values close to 3/2 and 5/3, respectively; the energy (kinetic plus magnetic) and cross-helicity often have approximately equal power law exponents with values intermediate between 3/2 and 5/3; and the Alfven ratio, the ratio of the kinetic to magnetic energy spectra, is often a slowly increasing function of frequency increasing from around 0.4 to 1 for frequencies in the inertial range. Differences between high- and low-speed wind are also discussed. Comparisons with phenomenological turbulence theories show that important aspects of the physics are yet unexplained.

Small-wind-systems application analysis. Technical report and executive summary

NASA Astrophysics Data System (ADS)

1981-06-01

A small wind energy conversion systems (SWECS) analysis was conducted to estimate the potential market for SWEC, or wind machines smaller than 100 kW for five selected applications. The goals were to aid manufacturers in attaining financing by convincing venture capital investors of the potential of SWECS and to aid government planners in allocating R and D expenditures that will effectively advance SWECS commercialization. Based on these goals, the study: (1) provides a basis for assisting the DOE in planning R and D programs that will advance the state of SWECS industry; (2) quantifies estimates of market size vs. installed system cost to enable industry to plan expansion of capacity and product lines; (3) identifies marketing strategies for industry to use in attaining financing from investors and in achieving sales goals; and (4) provides DOE with data that will assist in determining actions, incentives, and/or legislation required to achieve a commercially viable SWECS industry. The five applications were selected through an initial screening and priority-ranking analysis. The year of analysis was 1985, but all dollar amounts, such as fuel costs, are expressed in 1980 dollars. The five SWECS applications investigated were farm residences, non-farm residences, rural electric cooperatives, feed grinders, and remote communities.

VisibleWind: wind profile measurements at low altitude

NASA Astrophysics Data System (ADS)

Wilkerson, Tom; Bradford, Bill; Marchant, Alan; Apedaile, Tom; Wright, Cordell

2009-09-01

VisibleWindTM is developing an inexpensive rapid response system, for accurately characterizing wind shear and small scale wind phenomena in the boundary layer and for prospecting suitable locations for wind power turbines. The ValidWind system can also collect reliable "ground truth" for other remote wind sensors. The system employs small (0.25 m dia.) lightweight balloons and a tracker consisting of an Impulse 200 XL laser rangefinder coupled to a PC for automated data recording. Experiments on balloon trajectories demonstrate that the laser detection of range (+/- 0.5 m), together with measured azimuth and altitude, is an inexpensive, convenient, and capable alternative to other wind tracking methods. The maximum detection range has been increased to 2200 meters using micro-corner-cube retroreflector tape on balloons. Low power LEDs enable nighttime tracking. To avoid large balloon gyrations about the mean trajectory, we use balloons having low ascent rates and subcritical Reynolds numbers. Trajectory points are typically recorded every 4 - 7 seconds. Atmospheric features observed under conditions of inversions or "light and variable winds" include abrupt onsets of shear at altitudes of 100-250 m, velocity changes of order 1-3 m/s within layers of 10-20 m thickness, and veering of the wind direction by 180 degrees or more as altitude increases from 300 to 500 m. We have previously reported comparisons of balloon-based wind profiles with the output of a co-located sodar. Even with the Impulse rangefinder, our system still requires a "man in the loop" to track the balloon. A future system enhancement will automate balloon tracking, so that laser returns are obtained automatically at 1 Hz. While balloon measurements of large-scale, high altitude wind profiles are well known, this novel measurement system provides high-resolution, real-time characterization of the fluctuating local wind fields at the bottom of the boundary layer where wind power turbines and other

A diagnostic model to estimate winds and small-scale drag from Mars Observer PMIRR data

NASA Technical Reports Server (NTRS)

Barnes, J. R.

1993-01-01

Theoretical and modeling studies indicate that small-scale drag due to breaking gravity waves is likely to be of considerable importance for the circulation in the middle atmospheric region (approximately 40-100 km altitude) on Mars. Recent earth-based spectroscopic observations have provided evidence for the existence of circulation features, in particular, a warm winter polar region, associated with gravity wave drag. Since the Mars Observer PMIRR experiment will obtain temperature profiles extending from the surface up to about 80 km altitude, it will be extensively sampling middle atmospheric regions in which gravity wave drag may play a dominant role. Estimating the drag then becomes crucial to the estimation of the atmospheric winds from the PMIRR-observed temperatures. An interative diagnostic model based upon one previously developed and tested with earth satellite temperature data will be applied to the PMIRR measurements to produce estimates of the small-scale zonal drag and three-dimensional wind fields in the Mars middle atmosphere. This model is based on the primitive equations, and can allow for time dependence (the time tendencies used may be based upon those computed in a Fast Fourier Mapping procedure). The small-scale zonal drag is estimated as the residual in the zonal momentum equation; the horizontal winds having first been estimated from the meridional momentum equation and the continuity equation. The scheme estimates the vertical motions from the thermodynamic equation, and thus needs estimates of the diabatic heating based upon the observed temperatures. The latter will be generated using a radiative model. It is hoped that the diagnostic scheme will be able to produce good estimates of the zonal gravity wave drag in the Mars middle atmosphere, estimates that can then be used in other diagnostic or assimilation efforts, as well as more theoretical studies.

Confidence intervals for the population mean tailored to small sample sizes, with applications to survey sampling.

PubMed

Rosenblum, Michael A; Laan, Mark J van der

2009-01-07

The validity of standard confidence intervals constructed in survey sampling is based on the central limit theorem. For small sample sizes, the central limit theorem may give a poor approximation, resulting in confidence intervals that are misleading. We discuss this issue and propose methods for constructing confidence intervals for the population mean tailored to small sample sizes. We present a simple approach for constructing confidence intervals for the population mean based on tail bounds for the sample mean that are correct for all sample sizes. Bernstein's inequality provides one such tail bound. The resulting confidence intervals have guaranteed coverage probability under much weaker assumptions than are required for standard methods. A drawback of this approach, as we show, is that these confidence intervals are often quite wide. In response to this, we present a method for constructing much narrower confidence intervals, which are better suited for practical applications, and that are still more robust than confidence intervals based on standard methods, when dealing with small sample sizes. We show how to extend our approaches to much more general estimation problems than estimating the sample mean. We describe how these methods can be used to obtain more reliable confidence intervals in survey sampling. As a concrete example, we construct confidence intervals using our methods for the number of violent deaths between March 2003 and July 2006 in Iraq, based on data from the study "Mortality after the 2003 invasion of Iraq: A cross sectional cluster sample survey," by Burnham et al. (2006).

Small-scale Pressure-balanced Structures Driven by Mirror-mode Waves in the Solar Wind

NASA Astrophysics Data System (ADS)

Yao, Shuo; He, J.-S.; Tu, C.-Y.; Wang, L.-H.; Marsch, E.

2013-10-01

Recently, small-scale pressure-balanced structures (PBSs) have been studied with regard to their dependence on the direction of the local mean magnetic field B0 . The present work continues these studies by investigating the compressive wave mode forming small PBSs, here for B0 quasi-perpendicular to the x-axis of Geocentric Solar Ecliptic coordinates (GSE-x). All the data used were measured by WIND in the quiet solar wind. From the distribution of PBSs on the plane determined by the temporal scale and angle θxB between the GSE-x and B0 , we notice that at θxB = 115° the PBSs appear at temporal scales ranging from 700 s to 60 s. In the corresponding temporal segment, the correlations between the plasma thermal pressure P th and the magnetic pressure P B, as well as that between the proton density N p and the magnetic field strength B, are investigated. In addition, we use the proton velocity distribution functions to calculate the proton temperatures T and T ∥. Minimum Variance Analysis is applied to find the magnetic field minimum variance vector BN . We also study the time variation of the cross-helicity σc and the compressibility C p and compare these with values from numerical predictions for the mirror mode. In this way, we finally identify a short segment that has T > T ∥, proton β ~= 1, both pairs of P th-P B and N p-B showing anti-correlation, and σc ≈ 0 with C p > 0. Although the examination of σc and C p is not conclusive, it provides helpful additional information for the wave mode identification. Additionally, BN is found to be highly oblique to B0 . Thus, this work suggests that a candidate mechanism for forming small-scale PBSs in the quiet solar wind is due to mirror-mode waves.

A new low-turbulence wind tunnel for animal and small vehicle flight experiments

NASA Astrophysics Data System (ADS)

Quinn, Daniel B.; Watts, Anthony; Nagle, Tony; Lentink, David

2017-03-01

Our understanding of animal flight benefits greatly from specialized wind tunnels designed for flying animals. Existing facilities can simulate laminar flow during straight, ascending and descending flight, as well as at different altitudes. However, the atmosphere in which animals fly is even more complex. Flow can be laminar and quiet at high altitudes but highly turbulent near the ground, and gusts can rapidly change wind speed. To study flight in both laminar and turbulent environments, a multi-purpose wind tunnel for studying animal and small vehicle flight was built at Stanford University. The tunnel is closed-circuit and can produce airspeeds up to 50 m s-1 in a rectangular test section that is 1.0 m wide, 0.82 m tall and 1.73 m long. Seamless honeycomb and screens in the airline together with a carefully designed contraction reduce centreline turbulence intensities to less than or equal to 0.030% at all operating speeds. A large diameter fan and specialized acoustic treatment allow the tunnel to operate at low noise levels of 76.4 dB at 20 m s-1. To simulate high turbulence, an active turbulence grid can increase turbulence intensities up to 45%. Finally, an open jet configuration enables stereo high-speed fluoroscopy for studying musculoskeletal control in turbulent flow.

Market Acceleration | Wind | NREL

Science.gov Websites

model of a shrouded wind turbine at the 2016 Collegiate Wind Competition. Workforce Development and accurate information that articulates the potential impacts and benefits of wind and water power on education, rural economic development, public power partnerships, and small wind systems. An

Shape-Tailorable Graphene-Based Ultra-High-Rate Supercapacitor for Wearable Electronics.

PubMed

Xie, Binghe; Yang, Cheng; Zhang, Zhexu; Zou, Peichao; Lin, Ziyin; Shi, Gaoquan; Yang, Quanhong; Kang, Feiyu; Wong, Ching-Ping

2015-06-23

With the bloom of wearable electronics, it is becoming necessary to develop energy storage units, e.g., supercapacitors that can be arbitrarily tailored at the device level. Although gel electrolytes have been applied in supercapacitors for decades, no report has studied the shape-tailorable capability of a supercapacitor, for instance, where the device still works after being cut. Here we report a tailorable gel-based supercapacitor with symmetric electrodes prepared by combining electrochemically reduced graphene oxide deposited on a nickel nanocone array current collector with a unique packaging method. This supercapacitor with good flexibility and consistency showed excellent rate performance, cycling stability, and mechanical properties. As a demonstration, these tailorable supercapacitors connected in series can be used to drive small gadgets, e.g., a light-emitting diode (LED) and a minimotor propeller. As simple as it is (electrochemical deposition, stencil printing, etc.), this technique can be used in wearable electronics and miniaturized device applications that require arbitrarily shaped energy storage units.

Multifractal Analysis of the Small Time-Scale Boundary-Layer Characteristics of the Wind: the Anisotropy and Extremes

NASA Astrophysics Data System (ADS)

Fitton, G. F.; Tchiguirinskaia, I.; Schertzer, D. J.; Lovejoy, S.

2012-12-01

Under various physical conditions (mean temperature and velocity gradients, stratification and rotation) atmospheric turbulent flows remain intrinsically anisotropic. The immediate vicinity of physical boundaries rises to a greater complexity of the anisotropy effects. In this paper we address the issue of the scaling anisotropy of the wind velocity fields within the atmospheric boundary layer (ABL). Under the universal multifractal (UM) framework we compare the small time-scale (0.1 to 1,000 seconds) boundary-layer characteristics of the wind for two different case studies. The first case study consisted of a single mast located within a wind farm in Corsica, France. Three sonic anemometers were installed on the mast at 22, 23 and 43m, measuring three-dimensional wind velocity data at 10Hz. Wakes, complex terrain and buoyancy forces influenced the measurements. The second case study (GROWIAN experiment in Germany) consisted of an array of propeller anemometers measuring wind speed inflow data at 2.5Hz over flat terrain. The propeller anemometers were positioned vertically at 10, 50, 75, 100, 125 and 150m with four horizontal measurements taken at 75, 100 and 125m. The spatial distribution allowed us to calculate the horizontal and vertical shear structure functions of the horizontal wind. Both case studies are within a kilometre from the sea. For the first case study (10Hz measurements in a wind farm test site) the high temporal resolution of the data meant we observed Kolmogorov scaling from 0.2 seconds (with intermittency correction) right up to 1,000 seconds at which point a scaling break occurred. After the break we observed a scaling power law of approximately 2, which is in agreement with Bolgiano-Obukhov scaling theory with intermittency correction. However, for the second case study (2.5Hz on flat terrain) we only observed Kolmogorov scaling from 6.4 seconds (also with intermittency correction). The spectra of horizontal velocity components remain

Validation of Simplified Load Equations Through Loads Measurement and Modeling of a Small Horizontal-Axis Wind Turbine Tower

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dana, Scott; Van Dam, Jeroen J; Damiani, Rick R

As part of an ongoing effort to improve the modeling and prediction of small wind turbine dynamics, the National Renewable Energy Laboratory (NREL) tested a small horizontal-axis wind turbine in the field at the National Wind Technology Center. The test turbine was a 2.1-kW downwind machine mounted on an 18-m multi-section fiberglass composite tower. The tower was instrumented and monitored for approximately 6 months. The collected data were analyzed to assess the turbine and tower loads and further validate the simplified loads equations from the International Electrotechnical Commission (IEC) 61400-2 design standards. Field-measured loads were also compared to the outputmore » of an aeroelastic model of the turbine. In particular, we compared fatigue loads as measured in the field, predicted by the aeroelastic model, and calculated using the simplified design equations. Ultimate loads at the tower base were assessed using both the simplified design equations and the aeroelastic model output. The simplified design equations in IEC 61400-2 do not accurately model fatigue loads and a discussion about the simplified design equations is discussed.« less

Safety considerations in the design and operation of large wind turbines

NASA Technical Reports Server (NTRS)

Reilly, D. H.

1979-01-01

The engineering and safety techniques used to assure the reliable and safe operation of large wind turbine generators utilizing the Mod 2 Wind Turbine System Program as an example is described. The techniques involve a careful definition of the wind turbine's natural and operating environments, use of proven structural design criteria and analysis techniques, an evaluation of potential failure modes and hazards, and use of a fail safe and redundant component engineering philosophy. The role of an effective quality assurance program, tailored to specific hardware criticality, and the checkout and validation program developed to assure system integrity are described.

Piezoelectric wind turbine

NASA Astrophysics Data System (ADS)

Kishore, Ravi Anant; Priya, Shashank

2013-03-01

In past few years, there has been significant focus towards developing small scale renewable energy based power sources for powering wireless sensor nodes in remote locations such as highways and bridges to conduct continuous health monitoring. These prior efforts have led to the development of micro-scale solar modules, hydrogen fuel cells and various vibration based energy harvesters. However, the cost effectiveness, reliability, and practicality of these solutions remain a concern. Harvesting the wind energy using micro-to-small scale wind turbines can be an excellent solution in variety of outdoor scenarios provided they can operate at few miles per hour of wind speed. The conventional electromagnetic generator used in the wind mills always has some cogging torque which restricts their operation above certain cut-in wind speed. This study aims to develop a novel piezoelectric wind turbine that utilizes bimorph actuators for electro-mechanical energy conversion. This device utilizes a Savonius rotor that is connected to a disk having magnets at the periphery. The piezoelectric actuators arranged circumferentially around the disk also have magnets at the tip which interacts with the magnetic field of the rotating disk and produces cyclical deflection. The wind tunnel experiments were conducted between 2-12 mph of wind speeds to characterize and optimize the power output of the wind turbine. Further, testing was conducted in the open environment to quantify the response to random wind gusts. An attempt was made towards integration of the piezoelectric wind turbine with the wireless sensor node.

National Wind Technology Center | NREL

Science.gov Websites

. Wind Energy Research Wind turbine blade Wind energy research at the NWTC allows for validation and verification of large and small components and wind turbine systems. Photo by Dennis Schroeder / NREL 40935 Wind energy research at the NWTC has pioneered wind turbine components, systems, and modeling methods

A new low-turbulence wind tunnel for animal and small vehicle flight experiments

PubMed Central

Watts, Anthony; Nagle, Tony; Lentink, David

2017-01-01

Our understanding of animal flight benefits greatly from specialized wind tunnels designed for flying animals. Existing facilities can simulate laminar flow during straight, ascending and descending flight, as well as at different altitudes. However, the atmosphere in which animals fly is even more complex. Flow can be laminar and quiet at high altitudes but highly turbulent near the ground, and gusts can rapidly change wind speed. To study flight in both laminar and turbulent environments, a multi-purpose wind tunnel for studying animal and small vehicle flight was built at Stanford University. The tunnel is closed-circuit and can produce airspeeds up to 50 m s−1 in a rectangular test section that is 1.0 m wide, 0.82 m tall and 1.73 m long. Seamless honeycomb and screens in the airline together with a carefully designed contraction reduce centreline turbulence intensities to less than or equal to 0.030% at all operating speeds. A large diameter fan and specialized acoustic treatment allow the tunnel to operate at low noise levels of 76.4 dB at 20 m s−1. To simulate high turbulence, an active turbulence grid can increase turbulence intensities up to 45%. Finally, an open jet configuration enables stereo high-speed fluoroscopy for studying musculoskeletal control in turbulent flow. PMID:28405384

Computer-generated tailored feedback letters for smoking cessation: theoretical and empirical variability of tailoring.

PubMed

Schumann, Anja; John, Ulrich; Ulbricht, Sabina; Rüge, Jeannette; Bischof, Gallus; Meyer, Christian

2008-11-01

This study examines tailored feedback letters of a smoking cessation intervention that is conceptually based on the transtheoretical model, from a content-based perspective. Data of 2 population-based intervention studies, both randomized controlled trials, with total N=1044 were used. The procedure of the intervention, the tailoring principle for the feedback letters, and the content of the intervention materials are described in detail. Theoretical and empirical frequencies of unique feedback letters are presented. The intervention system was able to generate a total of 1040 unique letters with normative feedback only, and almost half a million unique letters with normative and ipsative feedback. Almost every single smoker in contemplation, preparation, action, and maintenance had an empirically unique combination of tailoring variables and received a unique letter. In contrast, many smokers in precontemplation shared a combination of tailoring variables and received identical letters. The transtheoretical model provides an enormous theoretical and empirical variability of tailoring. However, tailoring for a major subgroup of smokers, i.e. those who do not intend to quit, needs improvement. Conceptual ideas for additional tailoring variables are discussed.

Wind direction change criteria for wind turbine design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cliff, W.C.

1979-01-01

A method is presented for estimating the root mean square (rms) value of the wind direction change, ..delta..theta(tau) = theta(tau + tau) - theta(tau), that occurs over the swept area of wind turbine rotor systems. An equation is also given for the rms value of the wind direction change that occurs at a single point in space, i.e., a direcion change that a wind vane would measure. Assuming a normal probability density function for the lateral wind velocity change and relating this to angular changes, equations are given for calculating the expected number of wind direction changes, larger than anmore » arbitrary value, that will occur in 1 hr as well as the expected number that will occur during the design life of a wind turbine. The equations presented are developed using a small angle approximation and are, therefore, considered appropriate for wind direction changes of less than 30/sup 0/. The equations presented are based upon neutral atmospheric boundary-layer conditions and do not include information regarding events such as tornados, hurricanes, etc.« less

Reliability and cost evaluation of small isolated power systems containing photovoltaic and wind energy

NASA Astrophysics Data System (ADS)

Karki, Rajesh

Renewable energy application in electric power systems is growing rapidly worldwide due to enhanced public concerns for adverse environmental impacts and escalation in energy costs associated with the use of conventional energy sources. Photovoltaics and wind energy sources are being increasingly recognized as cost effective generation sources. A comprehensive evaluation of reliability and cost is required to analyze the actual benefits of utilizing these energy sources. The reliability aspects of utilizing renewable energy sources have largely been ignored in the past due the relatively insignificant contribution of these sources in major power systems, and consequently due to the lack of appropriate techniques. Renewable energy sources have the potential to play a significant role in the electrical energy requirements of small isolated power systems which are primarily supplied by costly diesel fuel. A relatively high renewable energy penetration can significantly reduce the system fuel costs but can also have considerable impact on the system reliability. Small isolated systems routinely plan their generating facilities using deterministic adequacy methods that cannot incorporate the highly erratic behavior of renewable energy sources. The utilization of a single probabilistic risk index has not been generally accepted in small isolated system evaluation despite its utilization in most large power utilities. Deterministic and probabilistic techniques are combined in this thesis using a system well-being approach to provide useful adequacy indices for small isolated systems that include renewable energy. This thesis presents an evaluation model for small isolated systems containing renewable energy sources by integrating simulation models that generate appropriate atmospheric data, evaluate chronological renewable power outputs and combine total available energy and load to provide useful system indices. A software tool SIPSREL+ has been developed which generates

Wind for Schools (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baring-Gould, I.

2010-05-01

As the United States dramatically expands wind energy deployment, the industry is challenged with developing a skilled workforce and addressing public resistance. Wind Powering America's Wind for Schools project addresses these issues by developing Wind Application Centers (WACs) at universities; WAC students assist in implementing school wind turbines and participate in wind courses, by installing small wind turbines at community "host" schools, by implementing teacher training with interactive curricula at each host school. This poster provides an overview of the first two years of the Wind for Schools project, primarily supporting activities in Colorado, Kansas, Nebraska, South Dakota, Montana, andmore » Idaho.« less

Why are Tailored Messages More Effective? A Multiple Mediation Analysis of a Breast Cancer Screening Intervention.

PubMed

Jensen, Jakob D; King, Andy J; Carcioppolo, Nicholas; Davis, LaShara

2012-10-01

Past research has found that tailoring increases the persuasive effectiveness of a message. However, the observed effect has been small and the explanatory mechanism remains unknown. To address these shortcomings, a tailoring software program was created that personalized breast cancer screening pamphlets according to risk, health belief model constructs, and visual preference. Women aged 40 and older ( N = 119) participated in a 2 (tailored vs. stock message) × 2 (charts/graphs vs. illustrated visuals) × 3 (nested replications of the visuals) experiment. Participants provided with tailored illustrated pamphlets expressed greater breast cancer screening intentions than those provided with other pamphlets. In a test of 10 different mediators, perceived message relevance was found to fully mediate the tailoring × visual interaction.

Grid-Free 2D Plasma Simulations of the Complex Interaction Between the Solar Wind and Small, Near-Earth Asteroids

NASA Technical Reports Server (NTRS)

Zimmerman, M. I.; Farrell, W. M.; Poppe, A. R.

2014-01-01

We present results from a new grid-free 2D plasma simulation code applied to a small, unmagnetized body immersed in the streaming solar wind plasma. The body was purposely modeled as an irregular shape in order to examine photoemission and solar wind plasma flow in high detail on the dayside, night-side, terminator and surface-depressed 'pocket' regions. Our objective is to examine the overall morphology of the various plasma interaction regions that form around a small body like a small near-Earth asteroid (NEA). We find that the object obstructs the solar wind flow and creates a trailing wake region downstream, which involves the interplay between surface charging and ambipolar plasma expansion. Photoemission is modeled as a steady outflow of electrons from illuminated portions of the surface, and under direct illumination the surface forms a non-monotonic or ''double-sheath'' electric potential upstream of the body, which is important for understanding trajectories and equilibria of lofted dust grains in the presence of a complex asteroid geometry. The largest electric fields are found at the terminators, where ambipolar plasma expansion in the body-sized night-side wake merges seamlessly with the thin photoelectric sheath on the dayside. The pocket regions are found to be especially complex, with nearby sunlit regions of positive potential electrically connected to unlit negative potentials and forming adjacent natural electric dipoles. For objects near the surface, we find electrical dissipation times (through collection of local environmental solar wind currents) that vary over at least 5 orders of magnitude: from 39 Micro(s) inside the near-surface photoelectron cloud under direct sunlight to less than 1 s inside the particle-depleted night-side wake and shadowed pocket regions

Wind for Schools: Fostering the Human Talent Supply Chain for a 20% Wind Energy Future (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baring-Gould, I.

2011-03-01

As the United States dramatically expands wind energy deployment, the industry is challenged with developing a skilled workforce and addressing public resistance. Wind Powering America's Wind for Schools project addresses these issues by: 1) Developing Wind Application Centers (WACs) at universities; WAC students assist in implementing school wind turbines and participate in wind courses. 2) Installing small wind turbines at community "host" schools. 3) Implementing teacher training with interactive curricula at each host school.

Tailored Testing Theory and Practice: A Basic Model, Normal Ogive Submodels, and Tailored Testing Algorithms

DTIC Science & Technology

1983-08-01

ACCESSION NO «• TITLE (and Sublltle) TAILORED TESTING THEORY AND PRACTICE: A BASIC MODEL , NORMAL OGIVE SUBMODELS, AND TAILORED TESTING ALGORITHMS 7...single common-factor model , the author derives the two- and three-parametir normal ogfve il’^irTr^ functions as submodels. For both of these...PAOEfWiwi Dmia Bnfnd) NPRDC TR 83-32 AUGUST 1983 TAILORED TESTING THEORY AND PRACTICE: A BASIC MODEL , NORMAL OGIVE SUBMODELS, AND TAILORED TESTING

Analysis and characterization of the vertical wind profile in UAE

NASA Astrophysics Data System (ADS)

Lee, W.; Ghedira, H.; Ouarda, T.; Gherboudj, I.

2011-12-01

low values during summer and high values during winter. This variation is mainly explained by the direct effect of air temperature on atmospheric stability. When the surface temperature becomes high, air is mixed well in atmospheric boundary layer. This phenomenon leads to vertically low wind speed change indicating low wind profile parameter. On the contrary, cold surface temperature prevents air from being mixed well in the boundary layer. This analysis is applied to different regions to see the spatial characteristics of wind in UAE. As a next step, a mesoscale model coupled with UAE roughness maps will be used to predict elevated wind speed. A micro-scale modeling approach will be also used to capture small-scale wind speed variability. This data will be combined with the NCMS data and tailored to the UAE by modeling the effects due to local changes in terrain elevation and local surface roughness changes and obstacles.

Companies Selected for Small Wind Turbine Project

Science.gov Websites

) 972-9246 Golden, Colo., Nov. 27, 1996 -- In an effort to develop cost-effective, low-maintenance wind have to perform effectively and reliably over a long period of time without maintenance. The companies

Using transonic small disturbance theory for predicting the aeroelastic stability of a flexible wind-tunnel model

NASA Technical Reports Server (NTRS)

Silva, Walter A.; Bennett, Robert M.

1990-01-01

The CAP-TSD (Computational Aeroelasticity Program - Transonic Small Disturbance) code, developed at the NASA - Langley Research Center, is applied to the Active Flexible Wing (AFW) wind tunnel model for prediction of the model's transonic aeroelastic behavior. Static aeroelastic solutions using CAP-TSD are computed. Dynamic (flutter) analyses are then performed as perturbations about the static aeroelastic deformations of the AFW. The accuracy of the static aeroelastic procedure is investigated by comparing analytical results to those from previous AFW wind tunnel experiments. Dynamic results are presented in the form of root loci at different Mach numbers for a heavy gas and air. The resultant flutter boundaries for both gases are also presented. The effects of viscous damping and angle-of-attack, on the flutter boundary in air, are presented as well.

Stall behavior of a scaled three-dimensional wind turbine blade

NASA Astrophysics Data System (ADS)

Mulleners, Karen; Melius, Matthew; Cal, Raul Bayoan

2014-11-01

The power generation of a wind turbine is influenced by many factors including the unsteady incoming flow characteristics, pitch regulation, and the geometry of the various turbine components. Within the framework of maximizing energy extraction, it is important to understand and tailor the aerodynamics of a wind turbine. In the interest of seeking further understanding into the complex flow over wind turbine blades, a three-dimensional scaled blade model has been designed and manufactured to be dynamically similar to a rotating full-scale NREL 5MW wind turbine blade. A wind tunnel experiment has been carried out in the 2.2 m × 1.8 m cross-section closed loop wind tunnel at DLR in Göttingen by means of time-resolved stereoscopic PIV. An extensive coherent structure analysis of the time-resolved velocity field over the suction side of the blade was performed to study stall characteristics under a geometrically induced pressure gradient. In particular, the radial extent and propagation of stalled flow regions were characterized for various static angles of attack.

The Impact of Natural Hazards such as Turbulent Wind Gusts on the Wind Energy Conversion Process

NASA Astrophysics Data System (ADS)

Wächter, M.; Hölling, M.; Milan, P.; Morales, A.; Peinke, J.

2012-12-01

Wind turbines operate in the atmospheric boundary layer, where they are exposed to wind gusts and other types of natural hazards. As the response time of wind turbines is typically in the range of seconds, they are affected by the small scale intermittent properties of the turbulent wind. We show evidence that basic features which are known for small-scale homogeneous isotropic turbulence, and in particular the well-known intermittency problem, have an important impact on the wind energy conversion process. Intermittent statistics include high probabilities of extreme events which can be related to wind gusts and other types of natural hazards. As a summarizing result we find that atmospheric turbulence imposes its intermittent features on the complete wind energy conversion process. Intermittent turbulence features are not only present in atmospheric wind, but are also dominant in the loads on the turbine, i.e. rotor torque and thrust, and in the electrical power output signal. We conclude that profound knowledge of turbulent statistics and the application of suitable numerical as well as experimental methods are necessary to grasp these unique features and quantify their effects on all stages of wind energy conversion.

Experimental Evidence for the Effect of Small Wind Turbine Proximity and Operation on Bird and Bat Activity

PubMed Central

Minderman, Jeroen; Pendlebury, Chris J.; Pearce-Higgins, James W.; Park, Kirsty J.

2012-01-01

The development of renewable energy technologies such as wind turbines forms a vital part of strategies to reduce greenhouse gas emissions worldwide. Although large wind farms generate the majority of wind energy, the small wind turbine (SWT, units generating <50 kW) sector is growing rapidly. In spite of evidence of effects of large wind farms on birds and bats, effects of SWTs on wildlife have not been studied and are likely to be different due to their potential siting in a wider range of habitats. We present the first study to quantify the effects of SWTs on birds and bats. Using a field experiment, we show that bird activity is similar in two distance bands surrounding a sample of SWTs (between 6–18 m hub height) and is not affected by SWT operation at the fine scale studied. At shorter distances from operating turbines (0–5 m), bat activity (measured as the probability of a bat “pass” per hour) decreases from 84% (71–91%) to 28% (11–54%) as wind speed increases from 0 to 14 m/s. This effect is weaker at greater distances (20–25 m) from operating turbines (activity decreases from 80% (65–89%) to 59% (32–81%)), and absent when they are braked. We conclude that bats avoid operating SWTs but that this effect diminishes within 20 m. Such displacement effects may have important consequences especially in landscapes where suitable habitat is limiting. Planning guidance for SWTs is currently lacking. Based on our results we recommend that they are sited at least 20 m away from potentially valuable bat habitat. PMID:22859969

Experimental evidence for the effect of small wind turbine proximity and operation on bird and bat activity.

PubMed

Minderman, Jeroen; Pendlebury, Chris J; Pearce-Higgins, James W; Park, Kirsty J

2012-01-01

The development of renewable energy technologies such as wind turbines forms a vital part of strategies to reduce greenhouse gas emissions worldwide. Although large wind farms generate the majority of wind energy, the small wind turbine (SWT, units generating <50 kW) sector is growing rapidly. In spite of evidence of effects of large wind farms on birds and bats, effects of SWTs on wildlife have not been studied and are likely to be different due to their potential siting in a wider range of habitats. We present the first study to quantify the effects of SWTs on birds and bats. Using a field experiment, we show that bird activity is similar in two distance bands surrounding a sample of SWTs (between 6-18 m hub height) and is not affected by SWT operation at the fine scale studied. At shorter distances from operating turbines (0-5 m), bat activity (measured as the probability of a bat "pass" per hour) decreases from 84% (71-91%) to 28% (11-54%) as wind speed increases from 0 to 14 m/s. This effect is weaker at greater distances (20-25 m) from operating turbines (activity decreases from 80% (65-89%) to 59% (32-81%)), and absent when they are braked. We conclude that bats avoid operating SWTs but that this effect diminishes within 20 m. Such displacement effects may have important consequences especially in landscapes where suitable habitat is limiting. Planning guidance for SWTs is currently lacking. Based on our results we recommend that they are sited at least 20 m away from potentially valuable bat habitat.

Tailor-welded blanks and their production

NASA Astrophysics Data System (ADS)

Yan, Qi

2005-01-01

Tailor welded blanks had been widely used in the automobile industry. A tailor welded blank consists of several flat sheets that were laser welded together before stamping. A combination of different materials, thickness, and coatings could be welded together to form a blank for stamping car body panels. As for the material for automobile industry, this technology was one of the development trend for automobile industry because of its weight reduction, safety improvement and economical use of materials. In this paper, the characters and production of tailor welded blanks in the market were discussed in detail. There had two major methods to produce tailor welded blanks. Laser welding would replace mesh seam welding for the production of tailor welded blanks in the future. The requirements on the edge preparation of unwelded blanks for tailor welded blanks were higher than the other steel processing technology. In order to produce the laser welded blank, there had the other process before the laser welding in the factory. In the world, there had three kinds of patterns for the large volume production of tailor welded blanks. In China, steel factory played the important role in the promotion of the application of tailor welded blanks. The competition for the supply of tailor welded blanks to the automobile industry would become fierce in the near future. As a result, the demand for the quality control on the production of tailor welded blanks would be the first priority concern for the factory.

Wind energy education projects. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ziegler, P.; Conlon, T.R.; Arcadi, T.

Two projects under DOE's Small-Scale Appropriate Energy Technology Grants Program have educated the public in a hands on way about wind energy systems. The first was awarded to Peter Ziegler of Berkeley, California, to design and build a walk-through exhibition structure powered by an adjoining wind-generator. This Wind Energy Pavilion was erected at Fort Funston in the Golden Gate National Recreation Area. It currently serves both as an enclosure for batteries and a variety of monitoring instruments, and as a graphic environment where the public can learn about wind energy. The second project, entitled Wind and Kid Power, involved anmore » educational program for a classroom of first through third grades in the Vallejo, Unified School District. The students studied weather, measured wind speeds and built small models of wind machines. They also built a weather station, and learned to use weather instruments. The grant funds enabled them to actually build and erect a Savonius wind machine at the Loma Vista Farm School.« less

Tailoring Cognitive Behavioral Therapy to Subtypes of Voice-Hearing

PubMed Central

Smailes, David; Alderson-Day, Ben; Fernyhough, Charles; McCarthy-Jones, Simon; Dodgson, Guy

2015-01-01

Cognitive behavioral therapy (CBT) for voice-hearing (i.e., auditory verbal hallucinations; AVH) has, at best, small to moderate effects. One possible reason for this limited efficacy is that current CBT approaches tend to conceptualize voice-hearing as a homogenous experience in terms of the cognitive processes involved in AVH. However, the highly heterogeneous nature of voice-hearing suggests that many different cognitive processes may be involved in the etiology of AVH. These heterogeneous voice-hearing experiences do, however, appear to cluster into a set of subtypes, opening up the possibility of tailoring treatment to the subtype of AVH that a voice-hearer reports. In this paper, we (a) outline our rationale for tailoring CBT to subtypes of voice-hearing, (b) describe CBT for three putative subtypes of AVH (inner speech-based AVH, memory-based AVH, and hypervigilance AVH), and (c) discuss potential limitations and problems with such an approach. We conclude by arguing that tailoring CBT to subtypes of voice-hearing could prove to be a valuable therapeutic development, which may be especially effective when used in early intervention in psychosis services. PMID:26733919

Optimization of monopiles for offshore wind turbines.

PubMed

Kallehave, Dan; Byrne, Byron W; LeBlanc Thilsted, Christian; Mikkelsen, Kristian Kousgaard

2015-02-28

The offshore wind industry currently relies on subsidy schemes to be competitive with fossil-fuel-based energy sources. For the wind industry to survive, it is vital that costs are significantly reduced for future projects. This can be partly achieved by introducing new technologies and partly through optimization of existing technologies and design methods. One of the areas where costs can be reduced is in the support structure, where better designs, cheaper fabrication and quicker installation might all be possible. The prevailing support structure design is the monopile structure, where the simple design is well suited to mass-fabrication, and the installation approach, based on conventional impact driving, is relatively low-risk and robust for most soil conditions. The range of application of the monopile for future wind farms can be extended by using more accurate engineering design methods, specifically tailored to offshore wind industry design. This paper describes how state-of-the-art optimization approaches are applied to the design of current wind farms and monopile support structures and identifies the main drivers where more accurate engineering methods could impact on a next generation of highly optimized monopiles. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

A study of large scale gust generation in a small scale atmospheric wind tunnel with applications to Micro Aerial Vehicles

NASA Astrophysics Data System (ADS)

Roadman, Jason Markos

Modern technology operating in the atmospheric boundary layer can always benefit from more accurate wind tunnel testing. While scaled atmospheric boundary layer tunnels have been well developed, tunnels replicating portions of the atmospheric boundary layer turbulence at full scale are a comparatively new concept. Testing at full-scale Reynolds numbers with full-scale turbulence in an "atmospheric wind tunnel" is sought. Many programs could utilize such a tool including Micro Aerial Vehicle(MAV) development, the wind energy industry, fuel efficient vehicle design, and the study of bird and insect flight, to name just a few. The small scale of MAVs provide the somewhat unique capability of full scale Reynolds number testing in a wind tunnel. However, that same small scale creates interactions under real world flight conditions, atmospheric gusts for example, that lead to a need for testing under more complex flows than the standard uniform flow found in most wind tunnels. It is for these reasons that MAVs are used as the initial testing application for the atmospheric gust tunnel. An analytical model for both discrete gusts and a continuous spectrum of gusts is examined. Then, methods for generating gusts in agreement with that model are investigated. Previously used methods are reviewed and a gust generation apparatus is designed. Expected turbulence and gust characteristics of this apparatus are compared with atmospheric data. The construction of an active "gust generator" for a new atmospheric tunnel is reviewed and the turbulence it generates is measured utilizing single and cross hot wires. Results from this grid are compared to atmospheric turbulence and it is shown that various gust strengths can be produced corresponding to weather ranging from calm to quite gusty. An initial test is performed in the atmospheric wind tunnel whereby the effects of various turbulence conditions on transition and separation on the upper surface of a MAV wing is investigated

75 FR 29365 - Job Corps: Final Finding of No Significant Impact (FONSI) for Small Wind Turbine Installation at...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-25

...Pursuant to the Council on Environmental Quality Regulations (40 CFR part 1500-08) implementing procedural provisions of the National Environmental Policy Act (NEPA), the Department of Labor, Office of the Secretary (OSEC), in accordance with 29 CFR 11.11(d), gives final notice of the proposed construction of a small wind turbine at the Pine Ridge Job Corps Center, and that this project will not have a significant adverse impact on the environment. In accordance with 29 CFR 11.11(d) and 40 CFR 1501.4(e)(2), a preliminary FONSI for the project was published in the April 5, 2010 Federal Register (75 FR 17161). No comments were received regarding the preliminary FONSI. OSEC has reviewed the conclusion of the environmental assessment (EA), and agrees with the finding of no significant impact. This notice serves as the Final Finding of No Significant Impact (FONSI) for Small Wind Turbine Installation at the Pine Ridge Job Corps Center located at 15710 Highway 385, Chadron, NE 69337. The preliminary FONSI and the EA are adopted in final with no change.

Aerodynamic study of a stall regulated horizontal-axis wind turbine

NASA Astrophysics Data System (ADS)

Constantinescu, S. G.; Crunteanu, D. E.; Niculescu, M. L.

2013-10-01

The wind energy is deemed as one of the most durable energetic variants of the future because the wind resources are immense. Furthermore, one predicts that the small wind turbines will play a vital role in the urban environment. Unfortunately, the complexity and the price of pitch regulated small horizontal-axis wind turbines represent ones of the main obstacles to widespread the use in populated zones. Moreover, the energetic efficiency of small stall regulated wind turbines has to be high even at low and medium wind velocities because, usually the cities are not windy places. During the running stall regulated wind turbines, due to the extremely broad range of the wind velocity, the angle of attack can reach high values and some regions of the blade will show stall and post-stall behavior. This paper deals with stall and post-stall regimes because they can induce significant vibrations, fatigue and even the wind turbine failure.

2014 Distributed Wind Market Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orell, A.; Foster, N.

2015-08-01

The cover of the 2014 Distributed Wind Market Report.According to the 2014 Distributed Wind Market Report, distributed wind reached a cumulative capacity of almost 1 GW (906 MW) in the United States in 2014, reflecting nearly 74,000 wind turbines deployed across all 50 states, Puerto Rico, and the U.S. Virgin Islands. In total, 63.6 MW of new distributed wind capacity was added in 2014, representing nearly 1,700 units and $170 million in investment across 24 states. In 2014, America's distributed wind energy industry supported a growing domestic industrial base as exports from United States-based small wind turbine manufacturers accounted formore » nearly 80% of United States-based manufacturers' sales.« less

Computational examination of utility scale wind turbine wake interactions

DOE PAGES

Okosun, Tyamo; Zhou, Chenn Q.

2015-07-14

We performed numerical simulations of small, utility scale wind turbine groupings to determine how wakes generated by upstream turbines affect the performance of the small turbine group as a whole. Specifically, various wind turbine arrangements were simulated to better understand how turbine location influences small group wake interactions. The minimization of power losses due to wake interactions certainly plays a significant role in the optimization of wind farms. Since wind turbines extract kinetic energy from the wind, the air passing through a wind turbine decreases in velocity, and turbines downstream of the initial turbine experience flows of lower energy, resultingmore » in reduced power output. Our study proposes two arrangements of turbines that could generate more power by exploiting the momentum of the wind to increase velocity at downstream turbines, while maintaining low wake interactions at the same time. Furthermore, simulations using Computational Fluid Dynamics are used to obtain results much more quickly than methods requiring wind tunnel models or a large scale experimental test.« less

Kansas Wind Energy Consortium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gruenbacher, Don

2015-12-31

This project addresses both fundamental and applied research problems that will help with problems defined by the DOE “20% Wind by 2030 Report”. In particular, this work focuses on increasing the capacity of small or community wind generation capabilities that would be operated in a distributed generation approach. A consortium (KWEC – Kansas Wind Energy Consortium) of researchers from Kansas State University and Wichita State University aims to dramatically increase the penetration of wind energy via distributed wind power generation. We believe distributed generation through wind power will play a critical role in the ability to reach and extend themore » renewable energy production targets set by the Department of Energy. KWEC aims to find technical and economic solutions to enable widespread implementation of distributed renewable energy resources that would apply to wind.« less

Wind for Schools: Developing Educational Programs to Train a New Workforce and the Next Generation of Wind Energy Experts (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flowers, L.; Baring-Gould, I.

2010-04-01

As the United States dramatically expands wind energy deployment, the industry is challenged with developing a skilled workforce and addressing public resistance. Wind Powering America's Wind for Schools project addresses these issues by: Developing Wind Application Centers (WACs) at universities; installing small wind turbines at community "host" schools; and implementing teacher training with interactive curricula at each host school.

Distributed Wind Competitiveness Improvement Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

The Competitiveness Improvement Project (CIP) is a periodic solicitation through the U.S. Department of Energy and its National Renewable Energy Laboratory. The Competitiveness Improvement Project (CIP) is a periodic solicitation through the U.S. Department of Energy and its National Renewable Energy Laboratory. Manufacturers of small and medium wind turbines are awarded cost-shared grants via a competitive process to optimize their designs, develop advanced manufacturing processes, and perform turbine testing. The goals of the CIP are to make wind energy cost competitive with other distributed generation technology and increase the number of wind turbine designs certified to national testing standards. Thismore » fact sheet describes the CIP and funding awarded as part of the project.ufacturers of small and medium wind turbines are awarded cost-shared grants via a competitive process to optimize their designs, develop advanced manufacturing processes, and perform turbine testing. The goals of the CIP are to make wind energy cost competitive with other distributed generation technology and increase the number of wind turbine designs certified to national testing standards. This fact sheet describes the CIP and funding awarded as part of the project.« less

Wind for Schools: Developing Educational Programs to Train the Next Generation of Wind Energy Experts (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baring-Gould, I.; Flowers, L.; Kelly, M.

2009-05-01

As the world moves toward a vision of expanded wind energy, the industry is faced with the challenges of obtaining a skilled workforce and addressing local wind development concerns. Wind Powering America's Wind for Schools Program works to address these issues. The program installs small wind turbines at community "host" schools while developing wind application centers at higher education institutions. Teacher training with interactive and interschool curricula is implemented at each host school, while students at the universities assist in implementing the host school systems while participating in other wind course work. This poster provides an overview of the program'smore » objectives, goals, approach, and results.« less

Assessment of Wind Datasets for Estimating Offshore Wind Energy along the Central California Coast

NASA Astrophysics Data System (ADS)

Wang, Y. H.; Walter, R. K.; Ruttenberg, B.; White, C.

2017-12-01

Offshore renewable energy along the central California coastline has gained significant interest in recent years. We present a comprehensive analysis of near-surface wind datasets available in this region to facilitate future estimates of wind power generation potential. The analyses are based on local NDBC buoys, satellite-based measurements (QuickSCAT and CCMP V2.0), reanalysis products (NARR and MERRA), and a regional climate model (WRF). There are substantial differences in the diurnal signal during different months among the various products (i.e., satellite-based, reanalysis, and modeled) relative to the local buoys. Moreover, the datasets tended to underestimate wind speed under light wind conditions and overestimate under strong wind conditions. In addition to point-to-point comparisons against local buoys, the spatial variations of bias and error in both the reanalysis products and WRF model data in this region were compared against satellite-based measurements. NARR's bias and root-mean-square-error were generally small in the study domain and decreased with distance from coastlines. Although its smaller spatial resolution is likely to be insufficient to reveal local effects, the small bias and error in near-surface winds, as well as the availability of wind data at the proposed turbine hub heights, suggests that NARR is an ideal candidate for use in offshore wind energy production estimates along the central California coast. The framework utilized here could be applied in other site-specific regions where offshore renewable energy is being considered.

Towards a mature offshore wind energy technology - guidelines from the opti-OWECS project

NASA Astrophysics Data System (ADS)

Kühn, M.; Bierbooms, W. A. A. M.; van Bussel, G. J. W.; Cockerill, T. T.; Harrison, R.; Ferguson, M. C.; Göransson, B.; Harland, L. A.; Vugts, J. H.; Wiecherink, R.

1999-01-01

The article reviews the main results of the recent European research project Opti-OWECS (Structural and Economic Optimisation of Bottom-Mounted Offshore Wind Energy Converters'), which has significantly improved the understanding of the requirements for a large-scale utilization of offshore wind energy. An integrated design approach was demonstrated for a 300 MW offshore wind farm at a demanding North Sea site. Several viable solutions were obtained and one was elaborated to include the design of all major components. Simultaneous structural and economic optimization took place during the different design stages. An offshore wind energy converter founded on a soft-soft monopile was tailored with respect to the distinct characteristics of dynamic wind and wave loading. The operation and maintenance behaviour of the wind farm was analysed by Monte Carlo simulations. With an optimized maintenance strategy and suitable hardware a high availability was achieved. Based upon the experience from the structural design, cost models for offshore wind farms were developed and linked to a European database of the offshore wind energy potential. This enabled the first consistent estimate of cost of offshore wind energy for entire European regions.

Wind Power Today and Tomorrow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Wind Power Today and Tomorrow is an annual publication that provides an overview of the wind research conducted under the U.S. Department of Energy's Wind and Hydropower Technologies Program. The purpose of Wind Power Today and Tomorrow is to show how DOE supports wind turbine research and deployment in hopes of furthering the advancement of wind technologies that produce clean, low-cost, reliable energy. Content objectives include: educate readers about the advantages and potential for widespread deployment of wind energy; explain the program's objectives and goals; describe the program's accomplishments in research and application; examine the barriers to widespread deployment; describemore » the benefits of continued research and development; facilitate technology transfer; and attract cooperative wind energy projects with industry. This 2003 edition of the program overview also includes discussions about wind industry growth in 2003, how DOE is taking advantage of low wind speed region s through advancing technology, and distributed applications for small wind turbines.« less

The design of nonlinear observers for wind turbine dynamic state and parameter estimation

NASA Astrophysics Data System (ADS)

Ritter, B.; Schild, A.; Feldt, M.; Konigorski, U.

2016-09-01

This contribution addresses the dynamic state and parameter estimation problem which arises with more advanced wind turbine controllers. These control devices need precise information about the system's current state to outperform conventional industrial controllers effectively. First, the necessity of a profound scientific treatment on nonlinear observers for wind turbine application is highlighted. Secondly, the full estimation problem is introduced and the variety of nonlinear filters is discussed. Finally, a tailored observer architecture is proposed and estimation results of an illustrative application example from a complex simulation set-up are presented.

Employee Perceptions of Workplace Health Promotion Programs: Comparison of a Tailored, Semi-Tailored, and Standardized Approach.

PubMed

Street, Tamara D; Lacey, Sarah J

2018-04-28

In the design of workplace health promotion programs (WHPPs), employee perceptions represent an integral variable which is predicted to translate into rate of user engagement (i.e., participation) and program loyalty. This study evaluated employee perceptions of three workplace health programs promoting nutritional consumption and physical activity. Programs included: (1) an individually tailored consultation with an exercise physiologist and dietitian; (2) a semi-tailored 12-week SMS health message program; and (3) a standardized group workshop delivered by an expert. Participating employees from a transport company completed program evaluation surveys rating the overall program, affect, and utility of: consultations ( n = 19); SMS program ( n = 234); and workshops ( n = 86). Overall, participants’ affect and utility evaluations were positive for all programs, with the greatest satisfaction being reported in the tailored individual consultation and standardized group workshop conditions. Furthermore, mode of delivery and the physical presence of an expert health practitioner was more influential than the degree to which the information was tailored to the individual. Thus, the synergy in ratings between individually tailored consultations and standardized group workshops indicates that low-cost delivery health programs may be as appealing to employees as tailored, and comparatively high-cost, program options.

Validation of Simplified Load Equations through Loads Measurement and Modeling of a Small Horizontal-Axis Wind Turbine Tower; NREL (National Renewable Energy Laboratory)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dana, S.; Damiani, R.; vanDam, J.

As part of an ongoing effort to improve the modeling and prediction of small wind turbine dynamics, NREL tested a small horizontal axis wind turbine in the field at the National Wind Technology Center (NWTC). The test turbine was a 2.1-kW downwind machine mounted on an 18-meter multi-section fiberglass composite tower. The tower was instrumented and monitored for approximately 6 months. The collected data were analyzed to assess the turbine and tower loads and further validate the simplified loads equations from the International Electrotechnical Commission (IEC) 61400-2 design standards. Field-measured loads were also compared to the output of an aeroelasticmore » model of the turbine. Ultimate loads at the tower base were assessed using both the simplified design equations and the aeroelastic model output. The simplified design equations in IEC 61400-2 do not accurately model fatigue loads. In this project, we compared fatigue loads as measured in the field, as predicted by the aeroelastic model, and as calculated using the simplified design equations.« less

Static Aeroelastic Scaling and Analysis of a Sub-Scale Flexible Wing Wind Tunnel Model

NASA Technical Reports Server (NTRS)

Ting, Eric; Lebofsky, Sonia; Nguyen, Nhan; Trinh, Khanh

2014-01-01

This paper presents an approach to the development of a scaled wind tunnel model for static aeroelastic similarity with a full-scale wing model. The full-scale aircraft model is based on the NASA Generic Transport Model (GTM) with flexible wing structures referred to as the Elastically Shaped Aircraft Concept (ESAC). The baseline stiffness of the ESAC wing represents a conventionally stiff wing model. Static aeroelastic scaling is conducted on the stiff wing configuration to develop the wind tunnel model, but additional tailoring is also conducted such that the wind tunnel model achieves a 10% wing tip deflection at the wind tunnel test condition. An aeroelastic scaling procedure and analysis is conducted, and a sub-scale flexible wind tunnel model based on the full-scale's undeformed jig-shape is developed. Optimization of the flexible wind tunnel model's undeflected twist along the span, or pre-twist or wash-out, is then conducted for the design test condition. The resulting wind tunnel model is an aeroelastic model designed for the wind tunnel test condition.

75 FR 27583 - Job Corps: Final Finding of No Significant Impact (FONSI) for Small Vertical Wind Turbine and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-17

...Pursuant to the Council on Environmental Quality Regulations (40 CFR part 1500-08) implementing procedural provisions of the National Environmental Policy Act (NEPA), the Department of Labor, Office of the Secretary (OSEC), in accordance with 29 CFR 11.11(d), gives final notice of the proposed construction of a small vertical axis wind turbine and solar cells at the Paul Simon Job Corps Center, and that this project will not have a significant adverse impact on the environment. In accordance with 29 CFR 11.11(d) and 40 CFR 1501.4(e)(2), a preliminary Environmental Assessment was presented through a public meeting held on 5/4/2010 at the Paul Simon Job Corps Center. No comments were received regarding the Environmental Assessment (EA). OSEC has reviewed the conclusion of the EA, and agrees with the finding of no significant impact. This notice serves as the Final Finding of No Significant Impact (FONSI) for Small Vertical Wind Turbine and Solar Installation at the Paul Simon Job Corps Center located at 3348 South Kedzie Avenue, Chicago, IL 60623. The preliminary EA are adopted in final with no change.

Wind tunnel measurements of the power output variability and unsteady loading in a micro wind farm model

NASA Astrophysics Data System (ADS)

Bossuyt, Juliaan; Howland, Michael; Meneveau, Charles; Meyers, Johan

2015-11-01

To optimize wind farm layouts for a maximum power output and wind turbine lifetime, mean power output measurements in wind tunnel studies are not sufficient. Instead, detailed temporal information about the power output and unsteady loading from every single wind turbine in the wind farm is needed. A very small porous disc model with a realistic thrust coefficient of 0.75 - 0.85, was designed. The model is instrumented with a strain gage, allowing measurements of the thrust force, incoming velocity and power output with a frequency response up to the natural frequency of the model. This is shown by reproducing the -5/3 spectrum from the incoming flow. Thanks to its small size and compact instrumentation, the model allows wind tunnel studies of large wind turbine arrays with detailed temporal information from every wind turbine. Translating to field conditions with a length-scale ratio of 1:3,000 the frequencies studied from the data reach from 10-4 Hz up to about 6 .10-2 Hz. The model's capabilities are demonstrated with a large wind farm measurement consisting of close to 100 instrumented models. A high correlation is found between the power outputs of stream wise aligned wind turbines, which is in good agreement with results from prior LES simulations. Work supported by ERC (ActiveWindFarms, grant no. 306471) and by NSF (grants CBET-113380 and IIA-1243482, the WINDINSPIRE project).

Response of small glaciers to climate change: runoff from glaciers of the Wind River range, Wyoming

NASA Astrophysics Data System (ADS)

Bliss, A. K.; Stamper, B.

2017-12-01

Runoff from glaciers affects downstream ecosystems by influencing the quantity, seasonality, and chemistry of the water. We describe the present state of glaciers in the Wind River range, Wyoming and consider how these glaciers will change in the future. Wind River glaciers have been losing mass in recent decades, as seen with geodetic techniques and by examining glacier morphology. Interestingly, the 2016/7 winter featured one of the largest snowfalls on record. Our primary focus is the Dinwoody Glacier ( 3 km^2, 3300-4000 m above sea level). We present data collected in mid-August 2017 including glacier ablation rates, snow line elevations, and streamflow. We compare measured glacier mass loss to streamflow at the glacier terminus and at a USGS stream gauge farther downstream. Using a hydrological model, we explore the fate of glacial runoff as it moves into downstream ecosystems and through ranchlands important to local people. The techniques used here can be applied to similar small-glacier systems in other parts of the world.

Wind power in Jamaica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, A.A.; Daniel, A.R.; Daniel, S.T.

1990-01-01

Parameters to evaluate the potential for using wind energy to generate electricity in Jamaica were obtained. These include the average wind power scaled to a height of 20 m at existing weather stations and temporary anemometer sites, the variation in annual and monthly wind power, and the frequency distribution of wind speed and wind energy available. Four small commercial turbines were assumed to be operating at some of the sites, and the estimated energy captured by them, the time they operated above their cut-in speed and their capacity factors were also determined. Diurnal variations of wind speed and prevailing windmore » directions are discussed and a map showing wind power at various sites was produced. Two stations with long-term averages, Manley and Morant Point, gave results which warranted further investigation. Results from some temporary stations are also encouraging. Mean wind speeds at two other sites in the Caribbean are given for comparison. A method for estimating the power exponent for scaling the wind speed from climatic data is described in Appendix 2.« less

Satellite SAR applied in offhore wind resource mapping: possibilities and limitations

NASA Astrophysics Data System (ADS)

Hasager, C. B.

Satellite remote sensing of ocean wind fields from Synthetic Aperture Radar (SAR) observations is presented. The study is based on a series of more than 60 ERS-2 SAR satellite scenes from the Horns Rev in the North Sea. The wind climate from the coastline and 80 km offshore is mapped in detail with a resolution of 400 m by 400 m grid cells. Spatial variations in wind speed as a function of wind direction and fetch are observed and discussed. The satellite wind fields are compared to in-situ observations from a tall offshore meteorological mast at which wind speed at 4 levels are analysed. The mast is located 14 km offshore and the wind climate is observed continously since May 1999. For offshore wind resource mapping the SAR-based wind field maps can constitute an alternative to in-situ observations and a practical method is developed for applied use in WAsP (Wind Atlas Analysis and Application Program). The software is the de facto world standard tool used for prediction of wind climate and power production from wind turbines and wind farms. The possibilities and limitations on achieving offshore wind resource estimates using SAR-based wind fields in lieu of in-situ data are discussed. It includes a presentation of the footprint area-averaging techniques tailored for SAR-based wind field maps. Averaging techniques are relevant for the reduction of noise apparent in SAR wind speed maps. Acknowledgments: Danish Research Agency (SAT-WIND Sagsnr. 2058-03-0006) for funding, ESA (EO-1356, AO-153) for ERS-2 SAR scenes, and Elsam Engineering A/S for in-situ met-data.

Wind structure and small-scale wind variability in the stratosphere and mesosphere during the November 1980 Energy Budget Campaign

NASA Technical Reports Server (NTRS)

Schmidlin, F. J.; Carlson, M.; Rees, D.; Offermann, D.; Philbrick, C. R.; Widdel, H. U.

1982-01-01

Rocket observations made from two sites in northern Scandinavia between November 6 and December 1, 1980, as part of the Energy Budget Campaign are discussed. It was found that significant vertical and temporal changes in the wind structure were present and that they coincided with different geomagnetic conditions, that is, quiet and enhanced. Before November 16, the meridional wind component above 60 km was found to be positive (southerly), whereas the magnitude of the zonal wind component increased with altitude. After November 16 the meridional component became negative (northerly), and the magnitude of the zonal wind component was observed to decrease with altitude. Time sections of the perturbations of the zonal wind reveal the presence of vertically propagating waves, suggesting gravity wave activity. The waves are found to increase in wavelength from 3-4 km near 40 km to more than 12 km near 80 km. The observational techniques made use of chaff foil, chemical trails, inflatable spheres, and parachutes.

Drivers of Public Attitudes towards Small Wind Turbines in the UK

PubMed Central

Tatchley, Cerian; Paton, Heather; Robertson, Emma; Minderman, Jeroen; Hanley, Nicholas; Park, Kirsty

2016-01-01

Small Wind Turbines (SWTs) are a growing micro-generation industry with over 870,000 installed units worldwide. No research has focussed on public attitudes towards SWTs, despite evidence the perception of such attitudes are key to planning outcomes and can be a barrier to installations. Here we present the results of a UK wide mail survey investigating public attitudes towards SWTs. Just over half of our respondents, who were predominantly older, white males, felt that SWTs were acceptable across a range of settings, with those on road signs being most accepted and least accepted in hedgerows and gardens. Concern about climate change positively influenced how respondents felt about SWTs. Respondent comments highlight visual impacts and perceptions of the efficiency of this technology are particularly important to this sector of the UK public. Taking this into careful consideration, alongside avoiding locating SWTs in contentious settings such as hedgerows and gardens where possible, may help to minimise public opposition to proposed installations. PMID:27011356

Drivers of Public Attitudes towards Small Wind Turbines in the UK.

PubMed

Tatchley, Cerian; Paton, Heather; Robertson, Emma; Minderman, Jeroen; Hanley, Nicholas; Park, Kirsty

2016-01-01

Small Wind Turbines (SWTs) are a growing micro-generation industry with over 870,000 installed units worldwide. No research has focussed on public attitudes towards SWTs, despite evidence the perception of such attitudes are key to planning outcomes and can be a barrier to installations. Here we present the results of a UK wide mail survey investigating public attitudes towards SWTs. Just over half of our respondents, who were predominantly older, white males, felt that SWTs were acceptable across a range of settings, with those on road signs being most accepted and least accepted in hedgerows and gardens. Concern about climate change positively influenced how respondents felt about SWTs. Respondent comments highlight visual impacts and perceptions of the efficiency of this technology are particularly important to this sector of the UK public. Taking this into careful consideration, alongside avoiding locating SWTs in contentious settings such as hedgerows and gardens where possible, may help to minimise public opposition to proposed installations.

Tailored program evaluation: Past, present, future.

PubMed

Suggs, L Suzanne; Cowdery, Joan E; Carroll, Jennifer B

2006-11-01

This paper discusses measurement issues related to the evaluation of computer-tailored health behavior change programs. As the first generation of commercially available tailored products is utilized in health promotion programming, programmers and researchers are becoming aware of the unique challenges that the evaluation of these programs presents. A project is presented that used an online tailored health behavior assessment (HBA) in a worksite setting. Process and outcome evaluation methods are described and include the challenges faced, and strategies proposed and implemented, for meeting them. Implications for future research in tailored program development, implementation, and evaluation are also discussed.

On the wind geometry of the Wolf-Rayet star EZ Canis Majoris

NASA Technical Reports Server (NTRS)

Schulte-Ladbeck, R. E.; Nordsieck, K. H.; Taylor, M.; Nook, M. A.; Bjorkman, K. S.; Magalhaes, A. M.; Anderson, C. M.

1991-01-01

Recent models of Wolf-Rayet star winds have been tailored to EZ CMa, and make predictions of the envelope structure and location of line-emitting regions. It is discussed how the wind structure of EZ CMa can be probed observationally through electron distribution integrals as measured by spectropolarimetry, and then present, analyze, and interpret a time-dependent spectropolarimetric data set of EZ CMa. The observations further the view of an electron-scattering wind that is axisymmetric, rotating, and expanding, with a variable mass-loss rate being responsible for the quasi-periodic polarimetric variability. It is demonstrated that the emission lines of EZ CMa are partially polarized, indicating that line photons are electron-scattered in the wind. The polarization in N V lambda 4945 and N IV lambda 4058 is observed to be larger than that of He II lambda 4686 and He I lambda 5876, as expected from ionization stratification.

Employee Perceptions of Workplace Health Promotion Programs: Comparison of a Tailored, Semi-Tailored, and Standardized Approach

PubMed Central

Street, Tamara D.; Lacey, Sarah J.

2018-01-01

In the design of workplace health promotion programs (WHPPs), employee perceptions represent an integral variable which is predicted to translate into rate of user engagement (i.e., participation) and program loyalty. This study evaluated employee perceptions of three workplace health programs promoting nutritional consumption and physical activity. Programs included: (1) an individually tailored consultation with an exercise physiologist and dietitian; (2) a semi-tailored 12-week SMS health message program; and (3) a standardized group workshop delivered by an expert. Participating employees from a transport company completed program evaluation surveys rating the overall program, affect, and utility of: consultations (n = 19); SMS program (n = 234); and workshops (n = 86). Overall, participants’ affect and utility evaluations were positive for all programs, with the greatest satisfaction being reported in the tailored individual consultation and standardized group workshop conditions. Furthermore, mode of delivery and the physical presence of an expert health practitioner was more influential than the degree to which the information was tailored to the individual. Thus, the synergy in ratings between individually tailored consultations and standardized group workshops indicates that low-cost delivery health programs may be as appealing to employees as tailored, and comparatively high-cost, program options. PMID:29710785

Spectral tailoring device

DOEpatents

Brager, H.R.; Schenter, R.E.; Carter, L.L.; Karnesky, R.A.

1987-08-05

A spectral tailoring device for altering the neutron energy spectra and flux of neutrons in a fast reactor thereby selectively to enhance or inhibit the transmutation rate of a target metrical to form a product isotope. Neutron moderators, neutron filters, neutron absorbers and neutron reflectors may be used as spectral tailoring devices. Depending on the intended use for the device, a member from each of these four classes of materials could be used singularly, or in combination, to provide a preferred neutron energy spectra and flux of the neutrons in the region of the target material. In one embodiment of the invention, an assembly is provided for enhancing the production of isotopes, such as cobalt 60 and gadolinium 153. In another embodiment of the invention, a spectral tailoring device is disposed adjacent a target material which comprises long lived or volatile fission products and the device is used to shift the neutron energy spectra and flux of neutrons in the region of the fission products to preferentially transmute them to produce a less volatile fission product inventory. 6 figs.

Small-Scale Gravity Waves in ER-2 MMS/MTP Wind and Temperature Measurements during CRYSTAL-FACE

NASA Technical Reports Server (NTRS)

Wang, L.; Alexander, M. J.; Bui, T. P.; Mahoney, M. J.

2006-01-01

Lower stratospheric wind and temperature measurements made from NASA's high-altitude ER-2 research aircraft during the CRYSTAL-FACE campaign in July 2002 were analyzed to retrieve information on small scale gravity waves (GWs) at the aircraft's flight level (typically approximately 20 km altitude). For a given flight segment, the S-transform (a Gaussian wavelet transform) was used to search for and identify small horizontal scale GW events, and to estimate their apparent horizontal wavelengths. The horizontal propagation directions of the events were determined using the Stokes parameter method combined with the cross S-transform analysis. The vertical temperature gradient was used to determine the vertical wavelengths of the events. GW momentum fluxes were calculated from the cross S-transform. Other wave parameters such as intrinsic frequencies were calculated using the GW dispersion relation. More than 100GW events were identified. They were generally high frequency waves with vertical wavelength of approximately 5 km and horizontal wavelength generally shorter than 20 km. Their intrinsic propagation directions were predominantly toward the east, whereas their ground-based propagation directions were primarily toward the west. Among the events, approximately 20% of them had very short horizontal wavelength, very high intrinsic frequency, and relatively small momentum fluxes, and thus they were likely trapped in the lower stratosphere. Using the estimated GW parameters and the background winds and stabilities from the NCAR/NCEP reanalysis data, we were able to trace the sources of the events using a simple reverse ray-tracing. More than 70% of the events were traced back to convective sources in the troposphere, and the sources were generally located upstream of the locations of the events observed at the aircraft level. Finally, a probability density function of the reversible cooling rate due to GWs was obtained in this study, which may be useful for cirrus

Computer-Tailored Intervention for Juvenile Offenders

PubMed Central

LEVESQUE, DEBORAH A.; JOHNSON, JANET L.; WELCH, CAROL A.; PROCHASKA, JANICE M.; FERNANDEZ, ANNE C.

2012-01-01

Studies assessing the efficacy of juvenile justice interventions show small effects on recidivism and other outcomes. This paper describes the development of a prototype of a multimedia computer-tailored intervention (“Rise Above Your Situation”or RAYS) that relies on an evidence-based model of behavior change, the Transtheoretical Model, and expert system technology to deliver assessments, feedback, printed reports, and counselor reports with intervention ideas. In a feasibility test involving 60 system-involved youths and their counselors, evaluations of the program were favorable: 91.7% of youths agreed that the program could help them make positive changes, and 86.7% agreed that the program could give their counselor helpful information about them. PMID:23264754

Small Wind Turbine Installation Compatibility Demonstration Methodology

DTIC Science & Technology

2013-08-01

was conducted for the Installation Technology Transfer Pro - gram. The project manager was Debbie Lawrence, US Army Engineer Re- search and Development...concerns (Rowley 2009). Though bases ban wind farms on or near DoD facilities when they are an- ticipated to be an unreasonable national security risk...related data collected by Fort Drum and a variety of other governmental agencies and private organizations. The pro - cess involved natural resources

Constructing a Plastic Bottle Wind Turbine as a Practical Aid for Learning about Using Wind Energy to Generate Electricity

ERIC Educational Resources Information Center

Appleyard, S. J.

2009-01-01

A simple horizontal axis wind turbine can be easily constructed using a 1.5 l PET plastic bottle, a compact disc and a small dynamo. The turbine operates effectively at low wind speeds and has a rotational speed of 500 rpm at a wind speed of about 14 km h[superscript -1]. The wind turbine can be used to demonstrate the relationship between open…

Radiometric correction of scatterometric wind measurements

NASA Technical Reports Server (NTRS)

1995-01-01

Use of a spaceborne scatterometer to determine the ocean-surface wind vector requires accurate measurement of radar backscatter from ocean. Such measurements are hindered by the effect of attenuation in the precipitating regions over sea. The attenuation can be estimated reasonably well with the knowledge of brightness temperatures observed by a microwave radiometer. The NASA SeaWinds scatterometer is to be flown on the Japanese ADEOS2. The AMSR multi-frequency radiometer on ADEOS2 will be used to correct errors due to attenuation in the SeaWinds scatterometer measurements. Here we investigate the errors in the attenuation corrections. Errors would be quite small if the radiometer and scatterometer footprints were identical and filled with uniform rain. However, the footprints are not identical, and because of their size one cannot expect uniform rain across each cell. Simulations were performed with the SeaWinds scatterometer (13.4 GHz) and AMSR (18.7 GHz) footprints with gradients of attenuation. The study shows that the resulting wind speed errors after correction (using the radiometer) are small for most cases. However, variations in the degree of overlap between the radiometer and scatterometer footprints affect the accuracy of the wind speed measurements.

Tailoring Programs to Needs: Helping the Small Businessowner.

ERIC Educational Resources Information Center

Hester, Susan B.; McDowell, Julie E.

1987-01-01

A needs assessment of New York State small apparel and textile manufacturers suggested possible roles for extension education, such as newsletters providing information on market trends, government assistance, and new technology; a telephone hotline system; specialized media programs; and liaison between industry and state and local governments.…

A ``Cyber Wind Facility'' for HPC Wind Turbine Field Experiments

NASA Astrophysics Data System (ADS)

Brasseur, James; Paterson, Eric; Schmitz, Sven; Campbell, Robert; Vijayakumar, Ganesh; Lavely, Adam; Jayaraman, Balaji; Nandi, Tarak; Jha, Pankaj; Dunbar, Alex; Motta-Mena, Javier; Craven, Brent; Haupt, Sue

2013-03-01

The Penn State ``Cyber Wind Facility'' (CWF) is a high-fidelity multi-scale high performance computing (HPC) environment in which ``cyber field experiments'' are designed and ``cyber data'' collected from wind turbines operating within the atmospheric boundary layer (ABL) environment. Conceptually the ``facility'' is akin to a high-tech wind tunnel with controlled physical environment, but unlike a wind tunnel it replicates commercial-scale wind turbines operating in the field and forced by true atmospheric turbulence with controlled stability state. The CWF is created from state-of-the-art high-accuracy technology geometry and grid design and numerical methods, and with high-resolution simulation strategies that blend unsteady RANS near the surface with high fidelity large-eddy simulation (LES) in separated boundary layer, blade and rotor wake regions, embedded within high-resolution LES of the ABL. CWF experiments complement physical field facility experiments that can capture wider ranges of meteorological events, but with minimal control over the environment and with very small numbers of sensors at low spatial resolution. I shall report on the first CWF experiments aimed at dynamical interactions between ABL turbulence and space-time wind turbine loadings. Supported by DOE and NSF.

Plasma-field Coupling at Small Length Scales in Solar Wind Near 1 AU

NASA Astrophysics Data System (ADS)

Livadiotis, G.; Desai, M. I.

2016-10-01

In collisionless plasmas such as the solar wind, the coupling between plasma constituents and the embedded magnetic field occurs on various temporal and spatial scales, and is primarily responsible for the transfer of energy between waves and particles. Recently, it was shown that the transfer of energy between solar wind plasma particles and waves is governed by a new and unique relationship: the ratio between the magnetosonic energy and the plasma frequency is constant, E ms/ω pl ˜ ℏ*. This paper examines the variability and substantial departure of this ratio from ℏ* observed at ˜1 au, which is caused by a dispersion of fast magnetosonic (FMS) waves. In contrast to the efficiently transferred energy in the fast solar wind, the lower efficiency of the slow solar wind can be caused by this dispersion, whose relation and characteristics are derived and studied. In summary, we show that (I) the ratio E ms/ω pl transitions continuously from the slow to the fast solar wind, tending toward the constant ℏ* (II) the transition is more efficient for larger thermal, Alfvén, or FMS speeds; (III) the fast solar wind is almost dispersionless, characterized by quasi-constant values of the FMS speed, while the slow wind is subject to dispersion that is less effective for larger wind or magnetosonic speeds; and (IV) the constant ℏ* is estimated with the best known precision, ℏ* ≈ (1.160 ± 0.083) × 10-22 Js.

NASA Agricultural Aircraft Research Program in the Langley Vortex Research Facility and the Langley Full Scale Wind Tunnel

NASA Technical Reports Server (NTRS)

Jordan, F. L., Jr.; Mclemore, H. C.; Bragg, M. B.

1978-01-01

The current status of aerial applications technology research at the Langley's Vortex Research Facility and Full-Scale Wind Tunnel is reviewed. Efforts have been directed mainly toward developing and validating the required experimental and theoretical research tools. A capability to simulate aerial dispersal of materials from agricultural airplanes with small-scale airplane models, numerical methods, and dynamically scaled test particles was demonstrated. Tests on wake modification concepts have proved the feasibility of tailoring wake properties aerodynamically to produce favorable changes in deposition and to provide drift control. An aerodynamic evaluation of the Thrush Commander 800 agricultural airplane with various dispersal systems installed is described. A number of modifications intended to provide system improvement to both airplane and dispersal system are examined, and a technique for documenting near-field spray characteristics is evaluated.

Aeroelastic Tailoring via Tow Steered Composites

NASA Technical Reports Server (NTRS)

Stanford, Bret K.; Jutte, Christine V.

2014-01-01

The use of tow steered composites, where fibers follow prescribed curvilinear paths within a laminate, can improve upon existing capabilities related to aeroelastic tailoring of wing structures, though this tailoring method has received relatively little attention in the literature. This paper demonstrates the technique for both a simple cantilevered plate in low-speed flow, as well as the wing box of a full-scale high aspect ratio transport configuration. Static aeroelastic stresses and dynamic flutter boundaries are obtained for both cases. The impact of various tailoring choices upon the aeroelastic performance is quantified: curvilinear fiber steering versus straight fiber steering, certifiable versus noncertifiable stacking sequences, a single uniform laminate per wing skin versus multiple laminates, and identical upper and lower wing skins structures versus individual tailoring.

Tailor-made force fields for crystal-structure prediction.

PubMed

Neumann, Marcus A

2008-08-14

A general procedure is presented to derive a complete set of force-field parameters for flexible molecules in the crystalline state on a case-by-case basis. The force-field parameters are fitted to the electrostatic potential as well as to accurate energies and forces generated by means of a hybrid method that combines solid-state density functional theory (DFT) calculations with an empirical van der Waals correction. All DFT calculations are carried out with the VASP program. The mathematical structure of the force field, the generation of reference data, the choice of the figure of merit, the optimization algorithm, and the parameter-refinement strategy are discussed in detail. The approach is applied to cyclohexane-1,4-dione, a small flexible ring. The tailor-made force field obtained for cyclohexane-1,4-dione is used to search for low-energy crystal packings in all 230 space groups with one molecule per asymmetric unit, and the most stable crystal structures are reoptimized in a second step with the hybrid method. The experimental crystal structure is found as the most stable predicted crystal structure both with the tailor-made force field and the hybrid method. The same methodology has also been applied successfully to the four compounds of the fourth CCDC blind test on crystal-structure prediction. For the five aforementioned compounds, the root-mean-square deviations between lattice energies calculated with the tailor-made force fields and the hybrid method range from 0.024 to 0.053 kcal/mol per atom around an average value of 0.034 kcal/mol per atom.

Investigation of Solar Wind Correlations and Solar Wind Modifications Near Earth by Multi-Spacecraft Observations: IMP 8, WIND and INTERBALL-1

NASA Technical Reports Server (NTRS)

Paularena, Karolen I.; Richardson, John D.; Zastenker, Georgy N.

2002-01-01

The foundation of this Project is use of the opportunity available during the ISTP (International Solar-Terrestrial Physics) era to compare solar wind measurements obtained simultaneously by three spacecraft - IMP 8, WIND and INTERBALL-1 at wide-separated points. Using these data allows us to study three important topics: (1) the size and dynamics of near-Earth mid-scale (with dimension about 1-10 million km) and small-scale (with dimension about 10-100 thousand km) solar wind structures; (2) the reliability of the common assumption that solar wind conditions at the upstream Lagrangian (L1) point accurately predict the conditions affecting Earth's magnetosphere; (3) modification of the solar wind plasma and magnetic field in the regions near the Earth magnetosphere, the foreshock and the magnetosheath. Our Project was dedicated to these problems. Our research has made substantial contributions to the field and has lead others to undertake similar work.

Neonates need tailored drug formulations.

PubMed

Allegaert, Karel

2013-02-08

Drugs are very strong tools used to improve outcome in neonates. Despite this fact and in contrast to tailored perfusion equipment, incubators or ventilators for neonates, we still commonly use drug formulations initially developed for adults. We would like to make the point that drug formulations given to neonates need to be tailored for this age group. Besides the obvious need to search for active compounds that take the pathophysiology of the newborn into account, this includes the dosage and formulation. The dosage or concentration should facilitate the administration of low amounts and be flexible since clearance is lower in neonates with additional extensive between-individual variability. Formulations need to be tailored for dosage variability in the low ranges and also to the clinical characteristics of neonates. A specific focus of interest during neonatal drug development therefore is a need to quantify and limit excipient exposure based on the available knowledge of their safety or toxicity. Until such tailored vials and formulations become available, compounding practices for drug formulations in neonates should be evaluated to guarantee the correct dosing, product stability and safety.

Event-based measurement of boundary-layer winds and topographic effects with a small unmanned aircraft system (sUas)

NASA Astrophysics Data System (ADS)

Riddell, K.; Hugenholtz, C.

2012-12-01

Numerical models are invaluable tools for developing and testing hypotheses about interactions and feedbacks between wind and topography. However, field-based measurements are equally important for building and enhancing confidence in model output. Several field methods are available, including conventional approaches using tall masts equipped with an array of anemometers, as well as weather balloons, but few methods are able to match the level of detail available in model simulations of topographically-modified windflow. Here we propose an alternative method that may enhance numerical models. The method involves a small unmanned aircraft system (sUas) equipped with a meteorological sensor payload. The sUas is a two blade helicopter that weighs 5.5 kg, and has a length of 1.32 m. We designed a simple measurement and control system using an Arduino micro-controller, which acquired measurements at pre-defined coordinates autonomously. The entire survey was pre-configured and uploaded to the aircraft, effectively avoiding the need for manual aircraft operation and data collection. We collected raw measurements at each waypoint, yielding a point cloud of windspeed data. During test flights the sUas was able to maintain a stable position (± 0.6 m vertical and horizontal) in wind speeds up to 50 km/h. We used the raw data to map the wind speed-up ratio relative to a reference anemometer. Although it would be preferable to acquire continuous measurements at each waypoint, the sUas method only provides a snapshot of wind at each location. However, despite this limitation, the sUas does fill a void in terms of spatial measurements within the boundary layer. It may be possible to enhance this method in the future through deployment of sUas swarms that measure wind concurrently at many locations. Furthermore, other sensors can be deployed on sUas for measuring aeolian processes such as dust.

Tailorable Release of Small Molecules Utilizing Plant Viral Nanoparticles and Fibrous Matrix

NASA Astrophysics Data System (ADS)

Cao, Jing

We have engineered Red clover necrotic mosaic virus (RCNMV) derived plant viral nanoparticles (PVNs) within a fibrous matrix to optimize its application for delivery and controlled release of active ingredients. RCNMV's structure and unique response to divalent cation depletion and re-addition enables the infusion of small molecules into its viral capsid through a pore formation mechanism. While this PVN technology shows a potential use in nano-scale therapeutic drug delivery, its inherent molecular dynamics to environmental stimuli places a constraint on its application and functionality as a vehicle for tailorable release of loading cargo. In this study, we enhance the understanding of the PVN technology by elucidating its mechanism for loading and triggered release of doxorubicin (Dox), a chemotherapeutic drug for breast cancer. Of critical importance is the methodology for manipulation of Dox's loading capacity and its binding location on either the exterior or interior of the virion capsid. The ability to control the active ingredient binding location provides an additional approach of tunable release from the PVN delivery vehicle besides its inherent pH- and ion- responsive release of loading cargo. The efficacious and controlled release strategy for agricultural active ingredients, such as nematicides, is also a large social need right now. Crop infestation of plant parasite nematodes causes in excess of 157 billion in worldwide crop damage annually. If an effective control strategy for these pests could be developed, it is estimated that the current market for effective nematicides is between 700 million and $1 billion each year worldwide. In this study, we report on the utilization of PVN technology to encapsulate the biological nematicide, abamectin (Abm), within the PVN's interior capsid (PVNAbm). Creating PVNAbm addresses Abm's issues of soil immobility while rendering a controlled release strategy for its bioavailability to root knot nematodes (RKNs

Byers Auto Group: A Case Study Into The Economics, Zoning, and Overall Process of Installing Small Wind Turbines at Two Automotive Dealerships in Ohio

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oteri, F.; Sinclair, K.

This paper provides the talking points about a case study on the installation of a $600,000 small wind project, the installation process, estimated annual energy production and percentage of energy needs met by the turbines.

Small Coronal Holes Near Active Regions as Sources of Slow Solar Wind

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Y.-M., E-mail: yi.wang@nrl.navy.mil

We discuss the nature of the small areas of rapidly diverging, open magnetic flux that form in the strong unipolar fields at the peripheries of active regions (ARs), according to coronal extrapolations of photospheric field measurements. Because such regions usually have dark counterparts in extreme-ultraviolet (EUV) images, we refer to them as coronal holes, even when they appear as narrow lanes or contain sunspots. Revisiting previously identified “AR sources” of slow solar wind from 1998 and 1999, we find that they are all associated with EUV coronal holes; the absence of well-defined He i 1083.0 nm counterparts to some ofmore » these holes is attributed to the large flux of photoionizing radiation from neighboring AR loops. Examining a number of AR-associated EUV holes during the 2014 activity maximum, we confirm that they are characterized by wind speeds of ∼300–450 km s{sup −1}, O{sup 7+}/O{sup 6+} ratios of ∼0.05–0.4, and footpoint field strengths typically of order 30 G. The close spacing between ARs at sunspot maximum limits the widths of unipolar regions and their embedded holes, while the continual emergence of new flux leads to rapid changes in the hole boundaries. Because of the highly nonradial nature of AR fields, the smaller EUV holes are often masked by the overlying canopy of loops, and may be more visible toward one solar limb than at central meridian. As sunspot activity declines, the AR remnants merge to form much larger, weaker, and longer-lived unipolar regions, which harbor the “classical” coronal holes that produce recurrent high-speed streams.« less

Automatically producing tailored web materials for public administration

NASA Astrophysics Data System (ADS)

Colineau, Nathalie; Paris, Cécile; Vander Linden, Keith

2013-06-01

Public administration organizations commonly produce citizen-focused, informational materials describing public programs and the conditions under which citizens or citizen groups are eligible for these programs. The organizations write these materials for generic audiences because of the excessive human resource costs that would be required to produce personalized materials for everyone. Unfortunately, generic materials tend to be longer and harder to understand than materials tailored for particular citizens. Our work explores the feasibility and effectiveness of automatically producing tailored materials. We have developed an adaptive hypermedia application system that automatically produces tailored informational materials and have evaluated it in a series of studies. The studies demonstrate that: (1) subjects prefer tailored materials over generic materials, even if the tailoring requires answering a set of demographic questions first; (2) tailored materials are more effective at supporting subjects in their task of learning about public programs; and (3) the time required to specify the demographic information on which the tailoring is based does not significantly slow down the subjects in their information seeking task.

Distributed Wind Competitiveness Improvement Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

2016-05-01

The Competitiveness Improvement Project (CIP) is a periodic solicitation through the U.S. Department of Energy and its National Renewable Energy Laboratory. Manufacturers of small and medium wind turbines are awarded cost-shared grants via a competitive process to optimize their designs, develop advanced manufacturing processes, and perform turbine testing. The goals of the CIP are to make wind energy cost competitive with other distributed generation technology and increase the number of wind turbine designs certified to national testing standards. This fact sheet describes the CIP and funding awarded as part of the project.

The problem of the second wind turbine - a note on a common but flawed wind power estimation method

NASA Astrophysics Data System (ADS)

Gans, F.; Miller, L. M.; Kleidon, A.

2010-06-01

Several recent wind power estimates suggest how this renewable resource can meet all of the current and future global energy demand with little impact on the atmosphere. These estimates are calculated using observed wind speeds in combination with specifications of wind turbine size and density to quantify the extractable wind power. Here we show that this common methodology is flawed because it does not account for energy removal by the turbines that is necessary to ensure the conservation of energy. We will first illustrate the common but flawed methodology using parameters from a recent global quantification of wind power in a simple experimental setup. For a small number of turbines at small scales, the conservation of energy hardly results in a difference when compared to the common method. However, when applied at large to global scales, the ability of radiative gradients to generate a finite amount of kinetic energy needs to be taken into account. Using the same experimental setup, we use the simplest method to ensure the conservation of energy to show a non-negligble decrease in wind velocity after the first turbine that will successively result in lower extraction of the downwind turbines. We then show how the conservation of energy inevitably results in substantially lower estimates of wind power at the global scale. Because conservation of energy is fundamental, we conclude that ultimately environmental constraints set the upper limit for wind power availability at the larger scale rather than detailed engineering specifications of the wind turbine design and placement.

Effect of blade flutter and electrical loading on small wind turbine noise

USDA-ARS?s Scientific Manuscript database

The effect of blade flutter and electrical loading on the noise level of two different size wind turbines was investigated at the Conservation and Production Research Laboratory (CPRL) near Bushland, TX. Noise and performance data were collected on two blade designs tested on a wind turbine rated a...

Solar wind and magnetosphere interactions

NASA Technical Reports Server (NTRS)

Russell, C. T.; Allen, J. H.; Cauffman, D. P.; Feynman, J.; Greenstadt, E. W.; Holzer, R. E.; Kaye, S. M.; Slavin, J. A.; Manka, R. H.; Rostoker, G.

1979-01-01

The relationship between the magnetosphere and the solar wind is addressed. It is noted that this interface determines how much of the solar plasma and field energy is transferred to the Earth's environment, and that this coupling not only varies in time, responding to major solar disturbances, but also to small changes in solar wind conditions and interplanetary field directions. It is recommended that the conditions of the solar wind and interplanetary medium be continuously monitored, as well as the state of the magnetosphere. Other recommendations include further study of the geomagnetic tail, tests of Pc 3,4 magnetic pulsations as diagnostics of the solar wind, and tests of kilometric radiation as a remote monitor of the auroral electrojet.

Dynamic properties of small-scale solar wind plasma fluctuations.

PubMed

Riazantseva, M O; Budaev, V P; Zelenyi, L M; Zastenker, G N; Pavlos, G P; Safrankova, J; Nemecek, Z; Prech, L; Nemec, F

2015-05-13

The paper presents the latest results of the studies of small-scale fluctuations in a turbulent flow of solar wind (SW) using measurements with extremely high temporal resolution (up to 0.03 s) of the bright monitor of SW (BMSW) plasma spectrometer operating on astrophysical SPECTR-R spacecraft at distances up to 350,000 km from the Earth. The spectra of SW ion flux fluctuations in the range of scales between 0.03 and 100 s are systematically analysed. The difference of slopes in low- and high-frequency parts of spectra and the frequency of the break point between these two characteristic slopes was analysed for different conditions in the SW. The statistical properties of the SW ion flux fluctuations were thoroughly analysed on scales less than 10 s. A high level of intermittency is demonstrated. The extended self-similarity of SW ion flux turbulent flow is constantly observed. The approximation of non-Gaussian probability distribution function of ion flux fluctuations by the Tsallis statistics shows the non-extensive character of SW fluctuations. Statistical characteristics of ion flux fluctuations are compared with the predictions of a log-Poisson model. The log-Poisson parametrization of the structure function scaling has shown that well-defined filament-like plasma structures are, as a rule, observed in the turbulent SW flows. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Wind tunnel study of helical and straight-bladed vertical-axis wind turbine wakes

NASA Astrophysics Data System (ADS)

Bagheri, Maryam; Araya, Daniel

2017-11-01

It is hypothesized that blade curvature can serve as a passive means to control fluid entrainment and wake recovery in vertical-axis wind turbine (VAWT) arrays. We test this experimentally in a wind tunnel using two different VAWT configurations, one with straight blades and another with helical blades, keeping all other experimental parameters fixed. A small-scale, commercially available VAWT (15W max power) is used as the baseline wind tunnel model in each case. The commercial VAWT blades are replaced with either straight or helical blades that are 3D-printed extrusions of the same airfoil cross-section. Results from smoke flow visualization, three-component wake velocity measurements, and turbine power data are presented. These results give insight into the potential use of VAWTs with curved blades in utility-scale wind farms.

Estimating the impacts of wind power on power systems—summary of IEA Wind collaboration

NASA Astrophysics Data System (ADS)

Holttinen, Hannele

2008-04-01

Adding wind power to power systems will have beneficial impacts by reducing the emissions of electricity production and reducing the operational costs of the power system as less fuel is consumed in conventional power plants. Wind power will also have a capacity value to a power system. However, possible negative impacts will have to be assessed to make sure that they will only offset a small part of the benefits and also to ensure the security of the power system operation. An international forum for the exchange of knowledge of power system impacts of wind power has been formed under the IEA Implementing Agreement on Wind Energy. The Task 'Design and Operation of Power Systems with Large Amounts of Wind Power' is analyzing existing case studies from different power systems. There are a multitude of studies completed and ongoing related to the cost of wind integration. However, the results are not easy to compare. This paper describes the general issues of wind power impacts on power systems and presents a comparison of results from ten case studies on increased balancing needs due to wind power.

The Potential of Combined Heat and Power Generation, Wind Power Generation and Load Management Techniques for Cost Reduction in Small Electricity Supply Systems.

NASA Astrophysics Data System (ADS)

Bass, Jeremy Hugh

Available from UMI in association with The British Library. Requires signed TDF. An evaluation is made of the potential fuel and financial savings possible when a small, autonomous diesel system sized to meet the demands of an individual, domestic consumer is adapted to include: (1) combined heat and power (CHP) generation, (2) wind turbine generation, (3) direct load control. The potential of these three areas is investigated by means of time-step simulation modelling on a microcomputer. Models are used to evaluate performance and a Net Present Value analysis used to assess costs. A cost/benefit analysis then enables those areas, or combination of areas, that facilitate and greatest savings to be identified. The modelling work is supported by experience gained from the following: (1) field study of the Lundy Island wind/diesel system, (2) laboratory testing of a small diesel generator set, (3) study of a diesel based CHP unit, (4) study of a diesel based direct load control system, (5) statistical analysis of data obtained from the long-term monitoring of a large number of individual household's electricity consumption. Rather than consider the consumer's electrical demand in isolation, a more flexible approach is adopted, with consumer demand being regarded as the sum of primarily two components: a small, electricity demand for essential services and a large, reschedulable demand for heating/cooling. The results of the study indicate that: (1) operating a diesel set in a CHP mode is the best strategy for both financial and fuel savings. A simple retrofit enables overall conversion efficiencies to be increased from 25% to 60%, or greater, at little cost. (2) wind turbine generation in association with direct load control is a most effective combination. (3) a combination of both the above areas enables greatest overall financial savings, in favourable winds resulting in unit energy costs around 20% of those of diesel only operation.

Byers Auto Group: A Case Study Into The Economics, Zoning, and Overall Process of Installing Small Wind Turbines at Two Automotive Dealerships in Ohio (Presentation)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sinclair, K.; Oteri, F.

This presentation provides the talking points about a case study on the installation of a $600,000 small wind project, the installation process, estimated annual energy production and percentage of energy needs met by the turbines.

Climbing therapy under PK-tailored prophylaxis.

PubMed

Stemberger, M; Schmit, E; Czepa, D; Kurnik, K; Spannagl, M

2014-01-01

Climbing has a low risk of injury and strengthens the entire musculature. Due to its benefits in physical and mental health as well as its high fun factor climbing is an established way of therapy. So far, the usefulness of climbing therapy has not been shown for people with haemophilia (PWH). A crucial requirement for physical activity in PWH is regular prophylaxis. As the patient's individual pharmacokinetic (PK) response varies significantly, PK-tailored prophylaxis may decrease bleeding frequency. We describe a man (age 25 years) with severe haemophilia A who took part in an 8.5-month weekly climbing program under PK-tailored prophylaxis. Bleeding frequency, factor consumption, joint health (Haemophilia Joint Health Score, HJHS), quality of life (Haemo-QoL-A) and climbing performance (UIAA scale) were assessed before and after the training. Prior to the study, the patient was on demand treatment. The patient was started on standard prophylaxis for a 2 months period and then observed for 6.5 months under PK-tailored prophylaxis. PK-tailored prophylaxis was targeted to a trough level of 1-3%. For high-impact activities a factor activity >15%, for low-impact activities a factor activity >5% was suggested. Climbing therapy was safe. The bleeding rate decreased from 14 (2012) to 1 (during the study period of 8.5 months). The one bleeding event was due to a missed infusion and was not triggered by physical activity. The elimination half-life using Bayesian statistics was determined to be 16h. Using this half-life for PK-tailored prophylaxis reduced the factor VIII consumption in comparison to standard prophylaxis. Joint health was particularly improved in the categories range of motion and swelling. Quality of life scores stayed at a high level. Climbing performance improved by 1 grade. The combination of PK-tailored prophylaxis with therapeutic climbing improved clinical outcome in this young adult with severe haemophilia. The tailored concept for high- and low

Supercapacitor Electrode Materials from Highly Porous Carbon Nanofibers with Tailored Pore Distributions

NASA Astrophysics Data System (ADS)

Chathurika Abeykoon, Nimali

Environmental and human health risks associated with the traditional methods of energy production (e.g., oil and gas) and intermittency and uncertainty of renewable sources (e.g., solar and wind) have led to exploring effective and alternative energy sources to meet the growing energy demands. Electricity based on energy storage devices are the most promising solutions for realization of these objectives. Among the energy storage devices, electrochemical double layer capacitors (EDLCs) or supercapacitors have become an attractive research interest due to their outstanding performance, especially high power densities, long cycle life and rapid charge and discharge times, which enables them to utilize in many applications including consumer electronics and transportation, where high power is needed. However, low energy density of supercapacitors is a major obstacle to compete with the commercially existing high energy density energy storage device such as batteries. The fabrication of advanced electrodes materials with very high surface area from novel precursors and utilization of electrolytes with higher operating voltages are essential to enhance energy density of supercapacitors. In this work, carbon nanofibers (CNFs) from different polymer precursors with new fabrication techniques are explored to develop highly porous carbon with tailored pore distributions to match with employed ionic liquid electrolytes (which possess high working voltages), to realize high energy storage capability. Novel electrode materials derived from electrospun immiscible polymer blends and synthesized copolymers and terpolymers were described. Pore distributions of CNFs were tailored by varying the composition of polymers in immiscible blends or varying the monomer ratios of copolymer or terpolymers. Chapter 1 gives the detailed introduction of supercapacitors including history and storage principle of EDLCs, fabrication of carbon nanofiber based electrodes and electrolytes employed

Coordinated Control of Wind Turbine and Energy Storage System for Reducing Wind Power Fluctuation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Chunghun; Muljadi, Eduard; Chung, Chung Choo

This paper proposes a method for the coordinated control of a wind turbine and an energy storage system (ESS). Because wind power (WP) is highly dependent on wind speed, which is variable, severe stability problems can be caused in power systems, especially when the WP has a high penetration level. To solve this problem, many power generation corporations or grid operators have begun using ESSs. An ESS has very quick response and good performance for reducing the impact of WP fluctuation; however, its installation cost is high. Therefore, it is important to design the control algorithm by considering both themore » ESS capacity and WP fluctuation. Thus, we propose a control algorithm to mitigate the WP fluctuation by using the coordinated control between the wind turbine and the ESS by considering the ESS capacity and the WP fluctuation. Using de-loaded control, according to the WP fluctuation and ESS capacity, we can expand the ESS lifespan and improve grid reliability by avoiding the extreme value of state of charge (SoC) (i.e., 0 or 1 pu). The effectiveness of the proposed method was validated via MATLAB/Simulink by considering a small power system that includes both a wind turbine generator and conventional generators that react to system frequency deviation. We found that the proposed method has better performance in SoC management, thereby improving the frequency regulation by mitigating the impact of the WP fluctuation on the small power system.« less

Coordinated Control of Wind Turbine and Energy Storage System for Reducing Wind Power Fluctuation

DOE PAGES

Kim, Chunghun; Muljadi, Eduard; Chung, Chung Choo

2017-12-27

This paper proposes a method for the coordinated control of a wind turbine and an energy storage system (ESS). Because wind power (WP) is highly dependent on wind speed, which is variable, severe stability problems can be caused in power systems, especially when the WP has a high penetration level. To solve this problem, many power generation corporations or grid operators have begun using ESSs. An ESS has very quick response and good performance for reducing the impact of WP fluctuation; however, its installation cost is high. Therefore, it is important to design the control algorithm by considering both themore » ESS capacity and WP fluctuation. Thus, we propose a control algorithm to mitigate the WP fluctuation by using the coordinated control between the wind turbine and the ESS by considering the ESS capacity and the WP fluctuation. Using de-loaded control, according to the WP fluctuation and ESS capacity, we can expand the ESS lifespan and improve grid reliability by avoiding the extreme value of state of charge (SoC) (i.e., 0 or 1 pu). The effectiveness of the proposed method was validated via MATLAB/Simulink by considering a small power system that includes both a wind turbine generator and conventional generators that react to system frequency deviation. We found that the proposed method has better performance in SoC management, thereby improving the frequency regulation by mitigating the impact of the WP fluctuation on the small power system.« less

An Evaluation of One- and Three-Parameter Logistic Tailored Testing Procedures for Use with Small Item Pools.

ERIC Educational Resources Information Center

McKinley, Robert L.; Reckase, Mark D.

A two-stage study was conducted to compare the ability estimates yielded by tailored testing procedures based on the one-parameter logistic (1PL) and three-parameter logistic (3PL) models. The first stage of the study employed real data, while the second stage employed simulated data. In the first stage, response data for 3,000 examinees were…

Sound and fluctuating disturbance measurements in the settling chamber and test section of a small, Mach 5 wind tunnel

NASA Technical Reports Server (NTRS)

Anders, J. B.; Stainback, P. C.; Beckwith, I. E.; Keefe, L. R.

1975-01-01

Disturbance measurements were made using a hot-wire anemometer and piezoelectric pressure transducers in the settling chamber and free stream of a small Mach 5 wind tunnel. Results from the two instruments are compared and acoustical disturbances in the settling chamber are discussed. The source of the test-section noise is identified as nozzle-wall waviness at low Reynolds numbers and as eddy-Mach-wave radiation from the turbulent boundary layer on the nozzle wall at high Reynolds numbers.

Performance of a small wind powered water pumping system

USDA-ARS?s Scientific Manuscript database

Lorentz helical pumps (Henstedt-Ulzburg, Germany) have been powered by solar energy for remote water pumping applications for many years, but from October 2005 to March 2008 a Lorentz helical pump was powered by wind energy at the USDA-ARS Conservation and Production Research Laboratory (CPRL) near ...

Tail Shape Design of Boat Wind Turbines

NASA Astrophysics Data System (ADS)

Singamsitty, Venkatesh

Wind energy is a standout among the most generally utilized sustainable power source assets. A great deal of research and improvements have been happening in the wind energy field. Wind turbines are mechanical devices that convert kinetic energy into electrical power. Boat wind turbines are for the small-scale generation of electric power. In order to catch wind energy effectively, boat wind turbines need to face wind direction. Tails are used in boat wind turbines to alter the wind turbine direction and receive the variation of the incoming direction of wind. Tails are used to change the performance of boat wind turbines in an effective way. They are required to generate a quick and steady response as per change in wind direction. Tails can have various shapes, and their effects on boat wind turbines are different. However, the effects of tail shapes on the performance of boat wind turbines are not thoroughly studied yet. In this thesis, five tail shapes were studied. Their effects on boat wind turbines were investigated. The power extracted by the turbines from the air and the force acting on the boat wind turbine tail were analyzed. The results of this thesis provide a guideline of tail shape design for boat wind turbines.

A model of tailoring effects: A randomized controlled trial examining the mechanisms of tailoring in a web-based STD screening intervention.

PubMed

Lustria, Mia Liza A; Cortese, Juliann; Gerend, Mary A; Schmitt, Karla; Kung, Ying Mai; McLaughlin, Casey

2016-11-01

This study explores the mechanisms of tailoring within the context of RU@Risk a brief Web-based intervention designed to promote sexually transmitted disease (STD) testing among young adults. This is one of a few studies to empirically examine theorized message processing mechanisms of tailoring and persuasion outcomes in a single model. Sexually active college students (N = 1065) completed a pretest, were randomly assigned to explore a tailored or nontailored website, completed a posttest, and were offered the opportunity to order a free at-home STD test kit. As intervention effects were hypothesized to work via increases in perceived risk, change in perceived risk from pretest to posttest by condition was examined. Hypothesized mechanisms of tailoring (perceived personal relevance, attention, and elaboration) were examined using structural equation modeling (SEM). All analyses controlled for demographic variables and sexual history. As predicted, perceived risk of STDs increased from pretest to posttest, but only in the tailored condition. Results revealed that exposure to the tailored (vs. nontailored) website increased perceived personal relevance, attention to, and elaboration of the message. These effects in turn were associated with greater perceived risk of STDs and intentions to get tested. Additionally, participants in the tailored condition were more likely to order a test kit. Findings provide insight into the mechanisms of tailoring with important implications for optimizing message design. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Measuring wind turbine wakes and unsteady loading in a micro wind farm model

NASA Astrophysics Data System (ADS)

Bossuyt, Juliaan; Meneveau, Charles; Meyers, Johan

2014-11-01

Very large wind farms, approximating the ``infinite'' asymptotic limit, are often studied with LES using periodic boundary conditions. In order to create an experimental realization of such large wind-turbine arrays in a wind tunnel experiment including over 100 turbines, a very small-scale turbine model based on a 3 cm diameter porous disk is designed. The porous disc matches a realistic thrust coefficient between 0.75--0.85, and the far wake flow characteristics of a rotating wind turbine. As a first step, we characterize the properties of a single model turbine. Hot-wire measurements are performed for uniform inflow conditions with different background turbulence intensity levels. Strain gage measurements are used to measure the mean value and power spectra of the thrust force, power output and wind velocity in front of the turbine. The dynamics of the wind turbine are modeled making it possible to measure force spectra at least up to the natural frequency of the model. This is shown by reproducing the -5/3 spectrum from the incoming flow and the vortex shedding signatures of an upstream obstruction. An array with a large number of these instrumented model turbines is placed in JHU's Corrsin wind tunnel, to study effects of farm layout on total power output and turbine loading. Work supported by ERC (ActiveWindFarms, Grant No: 306471), and by NSF (CBET-113380 and IIA-1243482).

Investigation on installation of offshore wind turbines

NASA Astrophysics Data System (ADS)

Wang, Wei; Bai, Yong

2010-06-01

Wind power has made rapid progress and should gain significance as an energy resource, given growing interest in renewable energy and clean energy. Offshore wind energy resources have attracted significant attention, as, compared with land-based wind energy resources, offshore wind energy resources are more promising candidates for development. Sea winds are generally stronger and more reliable and with improvements in technology, the sea has become a hot spot for new designs and installation methods for wind turbines. In the present paper, based on experience building offshore wind farms, recommended foundation styles have been examined. Furthermore, wave effects have been investigated. The split installation and overall installation have been illustrated. Methods appropriate when installing a small number of turbines as well as those useful when installing large numbers of turbines were analyzed. This investigation of installation methods for wind turbines should provide practical technical guidance for their installation.

Multidisciplinary tailoring of hot composite structures

NASA Technical Reports Server (NTRS)

Singhal, Surendra N.; Chamis, Christos C.

1993-01-01

A computational simulation procedure is described for multidisciplinary analysis and tailoring of layered multi-material hot composite engine structural components subjected to simultaneous multiple discipline-specific thermal, structural, vibration, and acoustic loads. The effect of aggressive environments is also simulated. The simulation is based on a three-dimensional finite element analysis technique in conjunction with structural mechanics codes, thermal/acoustic analysis methods, and tailoring procedures. The integrated multidisciplinary simulation procedure is general-purpose including the coupled effects of nonlinearities in structure geometry, material, loading, and environmental complexities. The composite material behavior is assessed at all composite scales, i.e., laminate/ply/constituents (fiber/matrix), via a nonlinear material characterization hygro-thermo-mechanical model. Sample tailoring cases exhibiting nonlinear material/loading/environmental behavior of aircraft engine fan blades, are presented. The various multidisciplinary loads lead to different tailored designs, even those competing with each other, as in the case of minimum material cost versus minimum structure weight and in the case of minimum vibration frequency versus minimum acoustic noise.

Small wind systems application analysis. Executive summary

NASA Astrophysics Data System (ADS)

1981-06-01

The potential market for SWECS, or wind machines smaller than 100 kW for five selected applications was estimated. The goals of the study were to aid manufacturers in attaining financing by convincing venture capital investors of the potential of SWECS and to aid government planners in allocating R and D expenditures that will effectively advance SWECS commercialization. The five applications were selected through an initial screening and priority-ranking analysis. The year of analysis was 1985, but all dollar amounts, such as fuel costs, are expressed in 1980 dollars. The five SWECS applications investigated were farm residences, non-farm residences rural electric cooperatives, feed grinders, and remote communities.

Distributed Wind Soft Costs: A Beginning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jimenez, Tony; Forsyth,Trudy; Preus, Robert

2016-06-14

Tony Jimenez presented this overview of distributed wind soft costs at the 2016 Small Wind Conference in Stevens Point, Wisconsin, on June 14, 2016. Soft costs are any non-hardware project costs, such as costs related to permitting fees, installer/developer profit, taxes, transaction costs, permitting, installation, indirect corporate costs, installation labor, and supply chain costs. This presentation provides an overview of soft costs, a distributed wind project taxonomy (of which soft costs are a subset), an alpha data set project demographics, data summary, and future work in this area.

Numerical investigation of the optimum wind turbine sitting for domestic flat roofs

NASA Astrophysics Data System (ADS)

Ishfaq, Salman Muhammad; Chaudhry, Hassam Nasarullah

2018-05-01

The power capacity of roof mounted wind turbines is dependent on several factors which influence its energy yield. In this paper, an investigation has been carried out using Computational Fluid Dynamics (CFD) to determine flow distribution and establish an optimum mounting location for a small wind turbine on a domestic flat roof. The realisable k-ɛ and SST k-ω turbulence models were compared to establish their consistency with one another with respect to the physical domain. Nine mounting locations were considered for a pole mounted wind turbine. Three windward positions on the upwind side of the flat surfaced building were considered as viable locations for mounting the small wind turbine. Out of the three windward locations, the central upwind (1,0) mounting position was seen to be producing the highest velocity of 5.3 m/s from the available ambient velocity which was 4 m/s. Therefore, this mounting location provided the highest extractable power for the wind turbine. Conclusively, wind properties along with the mounting locations can play a significant role in either enhancing or diminishing the small wind turbine's performance on a domestic flat roof.

Assessment Parameters and Matching between the Sites and Wind Turbines

NASA Astrophysics Data System (ADS)

Chermitti, A.; Bencherif, M.; Nakoul, Z.; Bibitriki, N.; Benyoucef, B.

The objective of this paper is to introduce the assessment parameters of the wind energy production of sites and pairing between the sites and wind turbines. The exploration is made with the wind data gathered at 10 m high is based on the atlas of the wind of Algeria established by the National office of the Meteorology runs 37 stations of measures. The data is used for a feasibility analysis of optimum future utilization of Wind generator potentiality in five promising sites covering a part of landscape types and regions in Algeria. Detailed technical assessment for the ten most promising potential wind sites was made using the capacity factor and the site effectiveness approach. The investigation was performed assuming several models of small, medium and big size wind machines representing different ranges of characteristic speeds and rated power suitable for water pumping and electric supply. The results show that small wind turbines could be installed in some coast region and medium wind turbines could be installed in the high plateau and some desert regions and utilized for water supply and electrical power generation, the sites having an important wind deposit, in high plateau we find Tiaret site's but in the desert there is some sites for example Adrar, Timimoun and In Amenas, in these sites could be installed a medium and big size wind turbines.

Dual stator winding variable speed asynchronous generator: optimal design and experiments

NASA Astrophysics Data System (ADS)

Tutelea, L. N.; Deaconu, S. I.; Popa, G. N.

2015-06-01

In the present paper is carried out a theoretical and experimental study of dual stator winding squirrel cage asynchronous generator (DSWA) behavior in the presence of saturation regime (non-sinusoidal) due to the variable speed operation. The main aims are the determination of the relations of calculating the equivalent parameters of the machine windings to optimal design using a Matlab code. Issue is limited to three phase range of double stator winding cage-induction generator of small sized powers, the most currently used in the small adjustable speed wind or hydro power plants. The tests were carried out using three-phase asynchronous generator having rated power of 6 [kVA].

New York State Police remote communications site small wind energy conversion system. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1985-03-01

This report concludes a year-long demonstration and study of the use of a North Wind Model HR2 wind energy conversion system to supply the power for a remote New York State Police microwave repeater site at Mt. Morris in the Adirondack Mountains. Data were collected on a multi-channel digital strip chart recorder which provided a printout of the real-time relation between windspeed, power output, battery capacity and voltage, and contribution from backup power. These data proved that the site could be run on wind power alone and predictions can now be made on the performance of an HR2 or similarmore » wind system at other sites. 5 figs., 1 tab.« less

Wind Power Innovation Enables Shift to Utility-Scale - Continuum Magazine

Science.gov Websites

the 1930s, a farmer in South Dakota built a small wind turbine on his farm, generating enough enough electricity to power thousands of homes. Aerial photo of large wind turbine with mountains in the background. Aerial view of the Siemens utility-scale wind turbine at the National Wind Technology Center

Can tailored interventions increase mammography use among HMO women?

PubMed

Lipkus, I M; Rimer, B K; Halabi, S; Strigo, T S

2000-01-01

Telephone counseling and tailored print communications have emerged as promising methods for promoting mammography screening. However, there has been little research testing, within the same randomized field trial, of the efficacy of these two methods compared to a high-quality usual care system for enhancing screening. This study addressed the question: Compared to usual care, is tailored telephone counseling more effective than tailored print materials for promoting mammography screening? Three-year randomized field trial. One thousand ninety-nine women aged 50 and older recruited from a health maintenance organization in North Carolina. Women were randomized to 1 of 3 groups: (1) usual care, (2) tailored print communications, and (3) tailored telephone counseling. Adherence to mammography screening based on self-reports obtained during 1995, 1996, and 1997. Compared to usual care alone, telephone counseling promoted a significantly higher proportion of women having mammograms on schedule (71% vs 61%) than did tailored print (67% vs 61%) but only after the first year of intervention (during 1996). Furthermore, compared to usual care, telephone counseling was more effective than tailored print materials at promoting being on schedule with screening during 1996 and 1997 among women who were off-schedule during the previous year. The effects of the intervention were most pronounced after the first intervention. Compared to usual care, telephone counseling seemed particularly effective at promoting change among nonadherent women, the group for whom the intervention was developed. These results suggest that telephone counseling, rather than tailored print, might be the preferred first-line intervention for getting nonadherent women on schedule for mammography screening. Many questions would have to be answered about why the tailored print intervention was not more powerful. Nevertheless, it is clear that additional interventions will be needed to maintain women

Distributed Wind Market Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forsyth, T.; Baring-Gould, I.

2007-11-01

Distributed wind energy systems provide clean, renewable power for on-site use and help relieve pressure on the power grid while providing jobs and contributing to energy security for homes, farms, schools, factories, private and public facilities, distribution utilities, and remote locations. America pioneered small wind technology in the 1920s, and it is the only renewable energy industry segment that the United States still dominates in technology, manufacturing, and world market share. The series of analyses covered by this report were conducted to assess some of the most likely ways that advanced wind turbines could be utilized apart from large, centralmore » station power systems. Each chapter represents a final report on specific market segments written by leading experts in this field. As such, this document does not speak with one voice but rather a compendium of different perspectives, which are documented from a variety of people in the U.S. distributed wind field.« less

Statistical and Spectral Analysis of Wind Characteristics Relevant to Wind Energy Assessment Using Tower Measurements in Complex Terrain

DOE PAGES

Belu, Radian; Koracin, Darko

2013-01-01

The main objective of the study was to investigate spatial and temporal characteristics of the wind speed and direction in complex terrain that are relevant to wind energy assessment and development, as well as to wind energy system operation, management, and grid integration. Wind data from five tall meteorological towers located in Western Nevada, USA, operated from August 2003 to March 2008, used in the analysis. The multiannual average wind speeds did not show significant increased trend with increasing elevation, while the turbulence intensity slowly decreased with an increase were the average wind speed. The wind speed and direction weremore » modeled using the Weibull and the von Mises distribution functions. The correlations show a strong coherence between the wind speed and direction with slowly decreasing amplitude of the multiday periodicity with increasing lag periods. The spectral analysis shows significant annual periodicity with similar characteristics at all locations. The relatively high correlations between the towers and small range of the computed turbulence intensity indicate that wind variability is dominated by the regional synoptic processes. Knowledge and information about daily, seasonal, and annual wind periodicities are very important for wind energy resource assessment, wind power plant operation, management, and grid integration.« less

2012 Market Report on U.S. Wind Technologies in Distributed Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orrell, Alice C.; Flowers, L. T.; Gagne, M. N.

2013-08-06

At the end of 2012, U.S. wind turbines in distributed applications reached a 10-year cumulative installed capacity of more than 812 MW from more than 69,000 units across all 50 states. In 2012 alone, nearly 3,800 wind turbines totaling 175 MW of distributed wind capacity were documented in 40 states and in the U.S. Virgin Islands, with 138 MW using utility-scale turbines (i.e., greater than 1 MW in size), 19 MW using mid-size turbines (i.e., 101 kW to 1 MW in size), and 18.4 MW using small turbines (i.e., up to 100 kW in size). Distributed wind is defined inmore » terms of technology application based on a wind project’s location relative to end-use and power-distribution infrastructure, rather than on technology size or project size. Distributed wind systems are either connected on the customer side of the meter (to meet the onsite load) or directly to distribution or micro grids (to support grid operations or offset large loads nearby). Estimated capacity-weighted average costs for 2012 U.S. distributed wind installations was $2,540/kW for utility-scale wind turbines, $2,810/kW for mid-sized wind turbines, and $6,960/kW for newly manufactured (domestic and imported) small wind turbines. An emerging trend observed in 2012 was an increased use of refurbished turbines. The estimated capacity-weighted average cost of refurbished small wind turbines installed in 2012 was $4,080/kW. As a result of multiple projects using utility-scale turbines, Iowa deployed the most new overall distributed wind capacity, 37 MW, in 2012. Nevada deployed the most small wind capacity in 2012, with nearly 8 MW of small wind turbines installed in distributed applications. In the case of mid-size turbines, Ohio led all states in 2012 with 4.9 MW installed in distributed applications. State and federal policies and incentives continued to play a substantial role in the development of distributed wind projects. In 2012, U.S. Treasury Section 1603 payments and grants and loans from the U

Tailoring sphere density for high pressure physical property measurements on liquids

NASA Astrophysics Data System (ADS)

Secco, R. A.; Tucker, R. F.; Balog, S. P.; Rutter, M. D.

2001-04-01

We present a new method of tailoring the density of a sphere for use as a probe in high pressure-temperature physical property experiments on liquids. The method consists of a composite sphere made of an inner, high density, metallic, spherical core and an exterior, low density, refractory, spherical shell or mantle. Micromechanical techniques are used to fabricate the composite sphere. We describe a relatively simple mechanical device that can grind hemispherical recesses as small as 200 μm in diameter in sapphire and as small as 500 μm in diameter in ruby hemispheres. Examples of composite spheres made with a Pt or WC core and Al2O3 shell used in metallic liquids pressurized to 16 GPa and 1900 K are shown.

On Electron-Scale Whistler Turbulence in the Solar Wind

NASA Technical Reports Server (NTRS)

Narita, Y.; Nakamura, R.; Baumjohann, W.; Glassmeier, K.-H.; Motschmann, U.; Giles, B.; Magnes, W.; Fischer, D.; Torbert, R. B.; Russell, C. T.

2016-01-01

For the first time, the dispersion relation for turbulence magnetic field fluctuations in the solar wind is determined directly on small scales of the order of the electron inertial length, using four-point magnetometer observations from the Magnetospheric Multiscale mission. The data are analyzed using the high-resolution adaptive wave telescope technique. Small-scale solar wind turbulence is primarily composed of highly obliquely propagating waves, with dispersion consistent with that of the whistler mode.

Hydrological Regimes of Small Catchments in the High Tatra Mountains Before and After Extraordinary Wind-Induced Deforestation

NASA Technical Reports Server (NTRS)

Holko, Ladislav; Hlavata, Helena; Kostka, Zdenek; Novak, Jan

2009-01-01

The paper presents the results of rainfall-runoff data analysis for small catchments of the upper Poprad River affected by wind-induced deforestation in November 2004. Before-event and afterevent measured data were compared in order to assess the impact of deforestation on hydrological regimes. Several characteristics were used including water balance, minimum and maximum runoff, runoff thresholds, number of runoff events, selected characteristics of events, runoff coefficients, and flashiness indices. Despite increased spring runoff minima, which in one catchment (Velick Creek) exceeded previously observed values after deforestation took place, it can be generally concluded that the impact of the deforestation was not clearly manifested in the analyzed hydrological data.

Ensemble downscaling in coupled solar wind-magnetosphere modeling for space weather forecasting

PubMed Central

Owens, M J; Horbury, T S; Wicks, R T; McGregor, S L; Savani, N P; Xiong, M

2014-01-01

Advanced forecasting of space weather requires simulation of the whole Sun-to-Earth system, which necessitates driving magnetospheric models with the outputs from solar wind models. This presents a fundamental difficulty, as the magnetosphere is sensitive to both large-scale solar wind structures, which can be captured by solar wind models, and small-scale solar wind “noise,” which is far below typical solar wind model resolution and results primarily from stochastic processes. Following similar approaches in terrestrial climate modeling, we propose statistical “downscaling” of solar wind model results prior to their use as input to a magnetospheric model. As magnetospheric response can be highly nonlinear, this is preferable to downscaling the results of magnetospheric modeling. To demonstrate the benefit of this approach, we first approximate solar wind model output by smoothing solar wind observations with an 8 h filter, then add small-scale structure back in through the addition of random noise with the observed spectral characteristics. Here we use a very simple parameterization of noise based upon the observed probability distribution functions of solar wind parameters, but more sophisticated methods will be developed in the future. An ensemble of results from the simple downscaling scheme are tested using a model-independent method and shown to add value to the magnetospheric forecast, both improving the best estimate and quantifying the uncertainty. We suggest a number of features desirable in an operational solar wind downscaling scheme. Key Points Solar wind models must be downscaled in order to drive magnetospheric models Ensemble downscaling is more effective than deterministic downscaling The magnetosphere responds nonlinearly to small-scale solar wind fluctuations PMID:26213518

Ensemble downscaling in coupled solar wind-magnetosphere modeling for space weather forecasting.

PubMed

Owens, M J; Horbury, T S; Wicks, R T; McGregor, S L; Savani, N P; Xiong, M

2014-06-01

Advanced forecasting of space weather requires simulation of the whole Sun-to-Earth system, which necessitates driving magnetospheric models with the outputs from solar wind models. This presents a fundamental difficulty, as the magnetosphere is sensitive to both large-scale solar wind structures, which can be captured by solar wind models, and small-scale solar wind "noise," which is far below typical solar wind model resolution and results primarily from stochastic processes. Following similar approaches in terrestrial climate modeling, we propose statistical "downscaling" of solar wind model results prior to their use as input to a magnetospheric model. As magnetospheric response can be highly nonlinear, this is preferable to downscaling the results of magnetospheric modeling. To demonstrate the benefit of this approach, we first approximate solar wind model output by smoothing solar wind observations with an 8 h filter, then add small-scale structure back in through the addition of random noise with the observed spectral characteristics. Here we use a very simple parameterization of noise based upon the observed probability distribution functions of solar wind parameters, but more sophisticated methods will be developed in the future. An ensemble of results from the simple downscaling scheme are tested using a model-independent method and shown to add value to the magnetospheric forecast, both improving the best estimate and quantifying the uncertainty. We suggest a number of features desirable in an operational solar wind downscaling scheme. Solar wind models must be downscaled in order to drive magnetospheric models Ensemble downscaling is more effective than deterministic downscaling The magnetosphere responds nonlinearly to small-scale solar wind fluctuations.

Genesis Solar-Wind Sample Return Mission: The Materials

NASA Technical Reports Server (NTRS)

Jurewicz, A. J. G.; Burnett, D. S.; Wiens, R. C.; Woolum, D.

2003-01-01

The Genesis spacecraft has two primary instruments which passively collect solar wind. The first is the collector arrays , a set of panels, each of which can deploy separately to sample the different kinds of solar wind (regimes). The second is the concentrator, an electrostatic mirror which will concentrate ions of mass 4 through mass 25 by about a factor of 20 by focusing them onto a 6 cm diameter target. When not deployed, these instruments fit into a compact canister. After a two year exposure time, the deployed instruments can be folded up, sealed into the canister, and returned to earth for laboratory analysis. Both the collector arrays and the concentrator will contain suites of ultra-high purity target materials, each of which is tailored to enable the analysis of a different family of elements. This abstract is meant to give a brief overview of the Genesis mission, insight into what materials were chosen for flight and why, as well as head s up information as to what will be available to planetary scientist for analysis when the solar-wind samples return to Earth in 2003. Earth. The elemental and isotopic abundances of the solar wind will be analyzed in state-of-the-art laboratories, and a portion of the sample will be archived for the use of future generations of planetary scientists. Technical information about the mission can be found at www.gps.caltech.edu/genesis.

Duration Test Report for the Entegrity EW50 Wind Turbine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, J.; Huskey, A.; Jager, D.

2012-12-01

This report summarizes the results of a duration test that NREL conducted on the Entegrity EW50 wind turbine. This test was conducted in accordance with the International Electrotechnical Commissions' (IEC) standard, Wind Turbine Generator System Part 2: Design requirements for small wind turbines, IEC 61400-2 Ed.2.0, 2006-03.

The resilience of Australian wind energy to climate change

NASA Astrophysics Data System (ADS)

Evans, Jason P.; Kay, Merlinde; Prasad, Abhnil; Pitman, Andy

2018-02-01

The Paris Agreement limits global average temperature rise to 2 °C and commits to pursuing efforts in limiting warming to 1.5 °C above pre-industrial levels. This will require rapid reductions in the emissions of greenhouse gases and the eventual decarbonisation of the global economy. Wind energy is an established technology to help achieve emissions reductions, with a cumulative global installed capacity of ~486 GW (2016). Focusing on Australia, we assess the future economic viability of wind energy using a 12-member ensemble of high-resolution regional climate simulations forced by Coupled Model Intercomparison Project (CMIP) output. We examine both near future (around 2030) and far future (around 2070) changes. Extractable wind power changes vary across the continent, though the most spatially coherent change is a small but significant decrease across southern regions. The cost of future wind energy generation, measured via the Levelised Cost of Energy (LCOE), increases negligibly in the future in regions with significant existing installed capacity. Technological developments in wind energy generation more than compensate for projected small reductions in wind, decreasing the LCOE by around 30%. These developments ensure viability for existing wind farms, and enhance the economic viability of proposed wind farms in Western Australian and Tasmania. Wind energy is therefore a resilient source of electricity over most of Australia and technological innovation entering the market will open new regions for energy production in the future.

Characteristics and Geoeffectiveness of Small-scale Magnetic Flux Ropes in the Solar Wind

NASA Astrophysics Data System (ADS)

Kim, Myeong Joon; Park, Kyung Sun; Lee, Dae-Young; Choi, Cheong-Rim; Kim, Rok Soon; Cho, Kyungsuk; Choi, Kyu-Cheol; Kim, Jaehun

2017-12-01

Magnetic flux ropes, often observed during intervals of interplanetary coronal mass ejections, have long been recognized to be critical in space weather. In this work, we focus on magnetic flux rope structure but on a much smaller scale, and not necessarily related to interplanetary coronal mass ejections. Using near-Earth solar wind advanced composition explorer (ACE) observations from 1998 to 2016, we identified a total of 309 small-scale magnetic flux ropes (SMFRs). We compared the characteristics of identified SMFR events with those of normal magnetic cloud (MC) events available from the existing literature. First, most of the MCs and SMFRs have similar values of accompanying solar wind speed and proton densities. However, the average magnetic field intensity of SMFRs is weaker ( 7.4 nT) than that of MCs ( 10.6 nT). Also, the average duration time and expansion speed of SMFRs are 2.5 hr and 2.6 km/s, respectively, both of which are smaller by a factor of 10 than those of MCs. In addition, we examined the geoeffectiveness of SMFR events by checking their correlation with magnetic storms and substorms. Based on the criteria Sym-H < -50 nT (for identification of storm occurrence) and AL < -200 nT (for identification of substorm occurrence), we found that for 88 SMFR events (corresponding to 28.5 % of the total SMFR events), substorms occurred after the impact of SMFRs, implying a possible triggering of substorms by SMFRs. In contrast, we found only two SMFRs that triggered storms. We emphasize that, based on a much larger database than used in previous studies, all these previously known features are now firmly confirmed by the current work. Accordingly, the results emphasize the significance of SMFRs from the viewpoint of possible triggering of substorms.

Wind energy developments in the 20th century

NASA Technical Reports Server (NTRS)

Vargo, D. J.

1974-01-01

Wind turbine systems for generating electrical power have been tested in many countries. Representative examples of turbines which have produced from 100 to 1250 kW are described. The advantages of wind energy consist of its being a nondepleting, nonpolluting, and free fuel source. Its disadvantages relate to the variability of wind and the high installation cost per kilowatt of capacity of wind turbines when compared to other methods of electric-power generation. High fuel costs and potential resource scarcity have led to a five-year joint NASA-NSF program to study wind energy. The program will study wind energy conversion and storage systems with respect to cost effectiveness, and will attempt to estimate national wind-energy potential and develop techniques for generator site selection. The studies concern a small-systems (50-250 kW) project, a megawatt-systems (500-3000 kW) project, supporting research and technology, and energy storage. Preliminary economic analyses indicate that wind-energy conversion can be competitive in high-average-wind areas.

The Spectrum of Wind Power Fluctuations

NASA Astrophysics Data System (ADS)

Bandi, Mahesh

2016-11-01

Wind is a variable energy source whose fluctuations threaten electrical grid stability and complicate dynamical load balancing. The power generated by a wind turbine fluctuates due to the variable wind speed that blows past the turbine. Indeed, the spectrum of wind power fluctuations is widely believed to reflect the Kolmogorov spectrum; both vary with frequency f as f - 5 / 3. This variability decreases when aggregate power fluctuations from geographically distributed wind farms are averaged at the grid via a mechanism known as geographic smoothing. Neither the f - 5 / 3 wind power fluctuation spectrum nor the mechanism of geographic smoothing are understood. In this work, we explain the wind power fluctuation spectrum from the turbine through grid scales. The f - 5 / 3 wind power fluctuation spectrum results from the largest length scales of atmospheric turbulence of order 200 km influencing the small scales where individual turbines operate. This long-range influence spatially couples geographically distributed wind farms and synchronizes farm outputs over a range of frequencies and decreases with increasing inter-farm distance. Consequently, aggregate grid-scale power fluctuations remain correlated, and are smoothed until they reach a limiting f - 7 / 3 spectrum. This work was funded by the Collective Interactions Unit, OIST Graduate University, Japan.

Quantification of wind flow in the European Mars Simulation Wind Tunnel Facility

NASA Astrophysics Data System (ADS)

Holstein-Rathlou, C.; Merrison, J. P.; Iversen, J. J.; Nornberg, P.

2012-04-01

We present the European Mars Simulation Wind Tunnel facility, a unique prototype facility capable of simulating a wide range of environmental conditions, such as those which can be found at the surface of Earth or Mars. The chamber complements several other large-scale simulation facilities at Aarhus University, Denmark. The facility consists of a 50 m3 environmental chamber capable of operating at low pressure (0.02 - 1000 mbar) and cryogenic temperatures (-130 °C up to +60 °C). This chamber houses a re-circulating wind tunnel capable of generating wind speeds up to 25 m/s and has a dust injection system that can produce suspended particulates (aerosols). It employs a unique LED based optical illumination system (solar simulator) and an advanced network based control system. Laser based optoelectronic instrumentation is used to quantify and monitor wind flow, dust suspension and deposition. This involves a commercial Laser Doppler Anemometer (LDA) and a Particle Dynamics Analysis receiver (PDA), which are small laser based instruments specifically designed for measuring wind speed and sizes of particles situated in a wind flow. Wind flow calibrations will be performed with the LDA system and presented. Pressure and temperature calibrations will follow in order to enable the facility to be used for the testing, development, calibration and comparison of e.g. meteorological sensors under a wide range of environmental conditions as well as multi-disciplinary scientific studies. The wind tunnel is accessible to international collaborators and space agencies for instrument testing, calibration and qualification. It has been financed by the European Space Agency (ESA) as well as the Aarhus University Science Faculty and the Villum Kann Rasmussen Foundation.

Promoting a Culture of Tailoring for Systems Engineering Policy Expectations

NASA Technical Reports Server (NTRS)

Blankenship, Van A.

2016-01-01

NASA's Marshall Space Flight Center (MSFC) has developed an integrated systems engineering approach to promote a culture of tailoring for program and project policy requirements. MSFC's culture encourages and supports tailoring, with an emphasis on risk-based decision making, for enhanced affordability and efficiency. MSFC's policy structure integrates the various Agency requirements into a single, streamlined implementation approach which serves as a "one-stop-shop" for our programs and projects to follow. The engineers gain an enhanced understanding of policy and technical expectations, as well as lesson's learned from MSFC's history of spaceflight and science missions, to enable them to make appropriate, risk-based tailoring recommendations. The tailoring approach utilizes a standard methodology to classify projects into predefined levels using selected mission and programmatic scaling factors related to risk tolerance. Policy requirements are then selectively applied and tailored, with appropriate rationale, and approved by the governing authorities, to support risk-informed decisions to achieve the desired cost and schedule efficiencies. The policy is further augmented by implementation tools and lifecycle planning aids which help promote and support the cultural shift toward more tailoring. The MSFC Customization Tool is an integrated spreadsheet that ties together everything that projects need to understand, navigate, and tailor the policy. It helps them classify their project, understand the intent of the requirements, determine their tailoring approach, and document the necessary governance approvals. It also helps them plan for and conduct technical reviews throughout the lifecycle. Policy tailoring is thus established as a normal part of project execution, with the tools provided to facilitate and enable the tailoring process. MSFC's approach to changing the culture emphasizes risk-based tailoring of policy to achieve increased flexibility, efficiency

Colliding Stellar Winds Structure and X-ray Emission

NASA Astrophysics Data System (ADS)

Pittard, J. M.; Dawson, B.

2018-04-01

We investigate the structure and X-ray emission from the colliding stellar winds in massive star binaries. We find that the opening angle of the contact discontinuity (CD) is overestimated by several formulae in the literature at very small values of the wind momentum ratio, η. We find also that the shocks in the primary (dominant) and secondary winds flare by ≈20° compared to the CD, and that the entire secondary wind is shocked when η ≲ 0.02. Analytical expressions for the opening angles of the shocks, and the fraction of each wind that is shocked, are provided. We find that the X-ray luminosity Lx∝η, and that the spectrum softens slightly as η decreases.

Unsteady aerodynamic analysis for offshore floating wind turbines under different wind conditions

PubMed Central

Xu, B. F.; Wang, T. G.; Yuan, Y.; Cao, J. F.

2015-01-01

A free-vortex wake (FVW) model is developed in this paper to analyse the unsteady aerodynamic performance of offshore floating wind turbines. A time-marching algorithm of third-order accuracy is applied in the FVW model. Owing to the complex floating platform motions, the blade inflow conditions and the positions of initial points of vortex filaments, which are different from the fixed wind turbine, are modified in the implemented model. A three-dimensional rotational effect model and a dynamic stall model are coupled into the FVW model to improve the aerodynamic performance prediction in the unsteady conditions. The effects of floating platform motions in the simulation model are validated by comparison between calculation and experiment for a small-scale rigid test wind turbine coupled with a floating tension leg platform (TLP). The dynamic inflow effect carried by the FVW method itself is confirmed and the results agree well with the experimental data of a pitching transient on another test turbine. Also, the flapping moment at the blade root in yaw on the same test turbine is calculated and compares well with the experimental data. Then, the aerodynamic performance is simulated in a yawed condition of steady wind and in an unyawed condition of turbulent wind, respectively, for a large-scale wind turbine coupled with the floating TLP motions, demonstrating obvious differences in rotor performance and blade loading from the fixed wind turbine. The non-dimensional magnitudes of loading changes due to the floating platform motions decrease from the blade root to the blade tip. PMID:25583859

Are we there yet? An examination of online tailored health communication.

PubMed

Suggs, L Suzanne; McIntyre, Chris

2009-04-01

Increasingly, the Internet is playing an important role in consumer health and patient-provider communication. Seventy-three percent of American adults are now online, and 79% have searched for health information on the Internet. This study provides a baseline understanding of the extent to which health consumers are able to find tailored communication online. It describes the current behavioral focus, the channels being used to deliver the tailored content, and the level of tailoring in online-tailored communication. A content analysis of 497 health Web sites found few examples of personalized, targeted, or tailored health sites freely available online. Tailored content was provided in 13 Web sites, although 15 collected individual data. More health risk assessment (HRA) sites included tailored feedback than other topics. The patterns that emerged from the analysis demonstrate that online health users can access a number of Web sites with communication tailored to their needs.

Understanding tailoring in communicating about health

PubMed Central

Hawkins, Robert P.; Kreuter, Matthew; Resnicow, Kenneth; Fishbein, Martin; Dijkstra, Arie

2011-01-01

‘Tailoring’ refers to any of a number of methods for creating communications individualized for their receivers, with the expectation that this individualization will lead to larger intended effects of these communications. Results so far have been generally positive but not consistently so, and this paper seeks to explicate tailoring to help focus future research. Tailoring involves either or both of two classes of goals (enhancing cognitive preconditions for message processing and enhancing message impact through modifying behavioral determinants of goal outcomes) and employs strategies of personalization, feedback and content matching. These goals and strategies intersect in a 2 × 3 matrix in which some strategies and their component tactics match better to some goals than to others. The paper illustrates how this framework can be systematically applied in generating research questions and identifying appropriate study designs for tailoring research. PMID:18349033

Wind for Schools: A National Data and Curricula Development Activity for Schools (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baring-Gould, I.

As the United States dramatically expands wind energy deployment, the industry is challenged with developing a skilled workforce and addressing public resistance. Wind Powering America?s Wind for Schools project addresses these issues by: 1) Developing Wind Application Centers (WACs) at universities; WAC students assist in implementing school wind turbines and participate in wind courses. 2) Installing small wind turbines at community 'host' schools. 3) Implementing teacher training with interactive curricula at each host school.

Tailored telephone counseling increases colorectal cancer screening.

PubMed

Rawl, Susan M; Christy, Shannon M; Monahan, Patrick O; Ding, Yan; Krier, Connie; Champion, Victoria L; Rex, Douglas

2015-08-01

To compare the efficacy of two interventions to promote colorectal cancer screening participation and forward stage movement of colorectal cancer screening adoption among first-degree relatives of individuals diagnosed with adenomatous polyps. One hundred fifty-eight first-degree relatives of individuals diagnosed with adenomatous polyps were randomly assigned to receive one of two interventions to promote colorectal cancer screening. Participants received either a tailored telephone counseling plus brochures intervention or a non-tailored print brochures intervention. Data were collected at baseline and 3 months post-baseline. Group differences and the effect of the interventions on adherence and stage movement for colorectal cancer screening were examined using t-tests, chi-square tests, and logistic regression. Individuals in the tailored telephone counseling plus brochures group were significantly more likely to complete colorectal cancer screening and to move forward on stage of change for fecal occult blood test, any colorectal cancer test stage and stage of the risk-appropriate test compared with individuals in the non-tailored brochure group at 3 months post-baseline. A tailored telephone counseling plus brochures intervention successfully promoted forward stage movement and colorectal cancer screening adherence among first-degree relatives of individuals diagnosed with adenomatous polyps. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Tailored to Fit

ERIC Educational Resources Information Center

Milbradt, Allan; Klock, Ed

2006-01-01

Building a new school can be exciting and creative. The process enables parents, students, educators and the community to explore their dreams and priorities, and create a facility tailored to their unique needs. Unfortunately, the process also can leave education institutions and communities feeling like they've bought an "off-the-rack" facility…

Elemental and charge state composition of the fast solar wind observed with SMS instruments on WIND

NASA Technical Reports Server (NTRS)

Gloeckler, G.; Galvin, A. B.; Ipavich, F. M.; Hamilton, D. C.; Bochsler, P.; Geiss, J.; Fisk, L. A.; Wilken, B.

1995-01-01

The elemental composition and charge state distributions of heavy ions of the solar wind provide essential information about: (1) atom-ion separation processes in the solar atmosphere leading to the 'FIP effect' (the overabundance of low First Ionization potential (FIP) elements in the solar wind compared to the photosphere); and (2) coronal temperature profiles, as well as mechanisms which heat the corona and accelerate the solar wind. This information is required for solar wind acceleration models. The SWICS instrument on Ulysses measures for all solar wind flow conditions the relative abundance of about 8 elements and 20 charge states of the solar wind. Furthermore, the Ulysses high-latitude orbit provides an unprecedented look at the solar wind from the polar coronal holes near solar minimum conditions. The MASS instrument on the WIND spacecraft is a high-mass resolution solar wind ion mass spectrometer that will provide routinely not only the abundances and charge state of all elements easily measured with SWICS, but also of N, Mg, S. The MASS sensor was fully operational at the end of 1994 and has sampled the in-ecliptic solar wind composition in both the slow and the corotating fast streams. This unique combination of SWICS on Ulysses and MASS on WIND allows us to view for the first time the solar wind from two regions of the large coronal hole. Observations with SWICS in the coronal hole wind: (1) indicate that the FIP effect is small; and (2) allow us determine the altitude of the maximum in the electron temperature profile, and indicate a maximum temperature of approximately 1.5 MK. New results from the SMS instruments on Wind will be compared with results from SWICS on Ulysses.

DOE/NREL supported wind energy activities in Indonesia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drouilhet, S.

1997-12-01

This paper describes three wind energy related projects which are underway in Indonesia. The first is a USAID/Winrock Wind for Island and Nongovernmental Development (WIND) project. The objectives of this project are to train local nongovernmental organizations (NGOs) in the siting, installation, operation, and maintenance of small wind turbines. Then to install up to 20 wind systems to provide electric power for productive end uses while creating micro-enterprises which will generate enough revenue to sustain the wind energy systems. The second project is a joint Community Power Corporation/PLN (Indonesian National Electric Utility) case study of hybrid power systems in villagemore » settings. The objective is to evaluate the economic viability of various hybrid power options for several different situations involving wind/photovoltaics/batteries/diesel. The third project is a World Bank/PLN preliminary market assessment for wind/diesel hybrid systems. The objective is to estimate the size of the total potential market for wind/diesel hybrid power systems in Indonesia. The study will examine both wind retrofits to existing diesel mini-grids and new wind-diesel plants in currently unelectrified villages.« less

Wind Turbine Bearing Diagnostics Based on Vibration Monitoring

NASA Astrophysics Data System (ADS)

Kadhim, H. T.; Mahmood, F. H.; Resen, A. K.

2018-05-01

Reliability maintenance can be considered as an accurate condition monitoring system which increasing beneficial and decreasing the cost production of wind energy. Supporting low friction of wind turbine rotating shaft is the main task of rolling element bearing and it is the main part that suffers from failure. The rolling failures elements have an economic impact and may lead to malfunctions and catastrophic failures. This paper concentrates on the vibration monitoring as a Non-Destructive Technique for assessing and demonstrates the feasibility of vibration monitoring for small wind turbine bearing defects based on LabVIEW software. Many bearings defects were created, such as inner race defect, outer race defect, and ball spin defect. The spectra data were recorded and compared with the theoretical results. The accelerometer with 4331 NI USB DAQ was utilized to acquiring, analyzed, and recorded. The experimental results were showed the vibration technique is suitable for diagnostic the defects that will be occurred in the small wind turbine bearings and developing a fault in the bearing which leads to increasing the vibration amplitude or peaks in the spectrum.

ZERODUR TAILORED for cryogenic application

NASA Astrophysics Data System (ADS)

Jedamzik, R.; Westerhoff, T.

2014-07-01

ZERODUR® glass ceramic from SCHOTT is known for its very low thermal expansion coefficient (CTE) at room temperature and its excellent CTE homogeneity. It is widely used for ground-based astronomical mirrors but also for satellite applications. Many reference application demonstrate the excellent and long lasting performance of ZERODUR® components in orbit. For space application a low CTE of the mirror material is required at cryogenic temperatures together with a good match of the thermal expansion to the supporting structure material. It is possible to optimize the coefficient of thermal expansion of ZERODUR® for cryogenic applications. This paper reports on measurements of thermal expansion of ZERODUR® down to cryogenic temperatures of 10 K performed by the PTB (Physikalisch Technische Bundesanstallt, Braunschweig, Germany, the national metrology laboratory). The ZERODUR® TAILORED CRYO presented in this paper has a very low coefficient of thermal expansion down to 70 K. The maximum absolute integrated thermal expansion down to 10 K is only about 20 ppm. Mirror blanks made from ZERODUR® TAILORED CRYO can be light weighted to almost 90% with our modern processing technologies. With ZERODUR® TAILORED CRYO, SCHOTT offers the mirror blank material for the next generation of space telescope applications.

Tailored nutrition education: is it really effective?

PubMed

Eyles, Helen; Ni Mhurchu, Cliona

2012-03-01

There has been a growing interest in tailored nutrition education over the previous decade, with a number of literature reviews suggesting this intervention strategy holds considerable potential. Nevertheless, the majority of intervention trials undertaken to date have employed subjective self-report outcome measures (such as dietary recalls). The aim of the present review is to further consider the likely true effect of tailored nutrition education by assessing the findings of tailored nutrition education intervention trials where objective outcome measures (such as sales data) have been employed. Four trials of tailored nutrition education employing objective outcome measures were identified: one was undertaken in eight low-cost supermarkets in New Zealand (2010; n 1104); one was an online intervention trial in Australia (2006; n 497); and two were undertaken in US supermarkets (1997 and 2001; n 105 and 296, respectively). Findings from the high-quality New Zealand trial were negative. Findings from the US trials were also generally negative, although reporting was poor making it difficult to assess quality. Findings from the high-quality online trial were positive, although have limited generalisability for public health. Trials employing objective outcome measures strongly suggest tailored nutrition education is not effective as a stand-alone strategy. However, further large, high-quality trials employing objective outcome measures are needed to determine the true effectiveness of this popular nutrition intervention strategy. Regardless, education plays an important role in generating social understanding and acceptance of broader interventions to improve nutrition.

Unsteady aerodynamic analysis for offshore floating wind turbines under different wind conditions.

PubMed

Xu, B F; Wang, T G; Yuan, Y; Cao, J F

2015-02-28

A free-vortex wake (FVW) model is developed in this paper to analyse the unsteady aerodynamic performance of offshore floating wind turbines. A time-marching algorithm of third-order accuracy is applied in the FVW model. Owing to the complex floating platform motions, the blade inflow conditions and the positions of initial points of vortex filaments, which are different from the fixed wind turbine, are modified in the implemented model. A three-dimensional rotational effect model and a dynamic stall model are coupled into the FVW model to improve the aerodynamic performance prediction in the unsteady conditions. The effects of floating platform motions in the simulation model are validated by comparison between calculation and experiment for a small-scale rigid test wind turbine coupled with a floating tension leg platform (TLP). The dynamic inflow effect carried by the FVW method itself is confirmed and the results agree well with the experimental data of a pitching transient on another test turbine. Also, the flapping moment at the blade root in yaw on the same test turbine is calculated and compares well with the experimental data. Then, the aerodynamic performance is simulated in a yawed condition of steady wind and in an unyawed condition of turbulent wind, respectively, for a large-scale wind turbine coupled with the floating TLP motions, demonstrating obvious differences in rotor performance and blade loading from the fixed wind turbine. The non-dimensional magnitudes of loading changes due to the floating platform motions decrease from the blade root to the blade tip. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Structural tailoring of engine blades (STAEBL)

NASA Technical Reports Server (NTRS)

Platt, C. E.; Pratt, T. K.; Brown, K. W.

1982-01-01

A mathematical optimization procedure was developed for the structural tailoring of engine blades and was used to structurally tailor two engine fan blades constructed of composite materials without midspan shrouds. The first was a solid blade made from superhybrid composites, and the second was a hollow blade with metal matrix composite inlays. Three major computerized functions were needed to complete the procedure: approximate analysis with the established input variables, optimization of an objective function, and refined analysis for design verification.

The dune effect on sand-transporting winds on Mars.

PubMed

Jackson, Derek W T; Bourke, Mary C; Smyth, Thomas A G

2015-11-05

Wind on Mars is a significant agent of contemporary surface change, yet the absence of in situ meteorological data hampers the understanding of surface-atmospheric interactions. Airflow models at length scales relevant to landform size now enable examination of conditions that might activate even small-scale bedforms (ripples) under certain contemporary wind regimes. Ripples have the potential to be used as modern 'wind vanes' on Mars. Here we use 3D airflow modelling to demonstrate that local dune topography exerts a strong influence on wind speed and direction and that ripple movement likely reflects steered wind direction for certain dune ridge shapes. The poor correlation of dune orientation with effective sand-transporting winds suggests that large dunes may not be mobile under modelled wind scenarios. This work highlights the need to first model winds at high resolution before inferring regional wind patterns from ripple movement or dune orientations on the surface of Mars today.

The dune effect on sand-transporting winds on Mars

PubMed Central

Jackson, Derek W. T.; Bourke, Mary C; Smyth, Thomas A. G.

2015-01-01

Wind on Mars is a significant agent of contemporary surface change, yet the absence of in situ meteorological data hampers the understanding of surface–atmospheric interactions. Airflow models at length scales relevant to landform size now enable examination of conditions that might activate even small-scale bedforms (ripples) under certain contemporary wind regimes. Ripples have the potential to be used as modern ‘wind vanes' on Mars. Here we use 3D airflow modelling to demonstrate that local dune topography exerts a strong influence on wind speed and direction and that ripple movement likely reflects steered wind direction for certain dune ridge shapes. The poor correlation of dune orientation with effective sand-transporting winds suggests that large dunes may not be mobile under modelled wind scenarios. This work highlights the need to first model winds at high resolution before inferring regional wind patterns from ripple movement or dune orientations on the surface of Mars today. PMID:26537669

Small wind turbine performance evaluation using field test data and a coupled aero-electro-mechanical model

NASA Astrophysics Data System (ADS)

Wallace, Brian D.

A series of field tests and theoretical analyses were performed on various wind turbine rotor designs at two Penn State residential-scale wind-electric facilities. This work involved the prediction and experimental measurement of the electrical and aerodynamic performance of three wind turbines; a 3 kW rated Whisper 175, 2.4 kW rated Skystream 3.7, and the Penn State designed Carolus wind turbine. Both the Skystream and Whisper 175 wind turbines are OEM blades which were originally installed at the facilities. The Carolus rotor is a carbon-fiber composite 2-bladed machine, designed and assembled at Penn State, with the intent of replacing the Whisper 175 rotor at the off-grid system. Rotor aerodynamic performance is modeled using WT_Perf, a National Renewable Energy Laboratory developed Blade Element Momentum theory based performance prediction code. Steady-state power curves are predicted by coupling experimentally determined electrical characteristics with the aerodynamic performance of the rotor simulated with WT_Perf. A dynamometer test stand is used to establish the electromechanical efficiencies of the wind-electric system generator. Through the coupling of WT_Perf and dynamometer test results, an aero-electro-mechanical analysis procedure is developed and provides accurate predictions of wind system performance. The analysis of three different wind turbines gives a comprehensive assessment of the capability of the field test facilities and the accuracy of aero-electro-mechanical analysis procedures. Results from this study show that the Carolus and Whisper 175 rotors are running at higher tip-speed ratios than are optimum for power production. The aero-electro-mechanical analysis predicted the high operating tip-speed ratios of the rotors and was accurate at predicting output power for the systems. It is shown that the wind turbines operate at high tip-speeds because of a miss-match between the aerodynamic drive torque and the operating torque of the wind

Lay Health Influencers: How They Tailor Brief Tobacco Cessation Interventions

ERIC Educational Resources Information Center

Yuan, Nicole P.; Castaneda, Heide; Nichter, Mark; Nichter, Mimi; Wind, Steven; Carruth, Lauren; Muramoto, Myra

2012-01-01

Interventions tailored to individual smoker characteristics have increasingly received attention in the tobacco control literature. The majority of tailored interventions are generated by computers and administered with printed materials or web-based programs. The purpose of this study was to examine the tailoring activities of community lay…

Investigating message-framing effects in the context of a tailored intervention promoting physical activity.

PubMed

van 't Riet, Jonathan; Ruiter, Robert A C; Werrij, Marieke Q; de Vries, Hein

2010-04-01

Health-promoting messages can be framed in terms of the gains associated with healthy behaviour or the losses associated with unhealthy behaviour. It has been argued that gain-framed messages promoting physical activity (PA) are more effective than loss-framed messages, but empirical findings are inconsistent. Also, no previous studies investigated the effects of gain- and loss-framed messages in the context of a computer-tailored PA intervention. In this study, we provided participants with computer-generated tailored feedback concerning their PA levels. In total, 787 participants entered in the study, of whom 299 completed all measures at a 3-month follow-up. We investigated whether gain- and loss-framed messages promoting PA affected information acceptance, attitude, intention and behaviour differently. The results showed that gain-framed messages resulted in stronger intentions to be physically active than loss-framed messages. This did not result in a significant increase in actual PA, however, as measured by a 3-month follow-up assessment. For information acceptance and attitude, a non-significant advantage of gain-framed messages was found. All effects had small effect sizes. Thus, whereas gain-framed information might be more persuasive than loss-framed information when it comes to promoting PA, the differences between gain- and loss-framed messages are likely to be small.

Information Tailoring Enhancements for Large-Scale Social Data

DTIC Science & Technology

2016-06-15

Intelligent Automation Incorporated Information Tailoring Enhancements for Large-Scale... Automation Incorporated Progress Report No. 3 Information Tailoring Enhancements for Large-Scale Social Data Submitted in accordance with...1 Work Performed within This Reporting Period .................................................... 2 1.1 Enhanced Named Entity Recognition (NER

Determination of wind from NIMBUS 6 satellite sounding data

NASA Technical Reports Server (NTRS)

Carle, W. E.; Scoggins, J. R.

1981-01-01

Objective methods of computing upper level and surface wind fields from NIMBUS 6 satellite sounding data are developed. These methods are evaluated by comparing satellite derived and rawinsonde wind fields on gridded constant pressure charts in four geographical regions. Satellite-derived and hourly observed surface wind fields are compared. Results indicate that the best satellite-derived wind on constant pressure charts is a geostrophic wind derived from highly smoothed fields of geopotential height. Satellite-derived winds computed in this manner and rawinsonde winds show similar circulation patterns except in areas of small height gradients. Magnitudes of the standard deviation of the differences between satellite derived and rawinsonde wind speeds range from approximately 3 to 12 m/sec on constant pressure charts and peak at the jet stream level. Fields of satellite-derived surface wind computed with the logarithmic wind law agree well with fields of observed surface wind in most regions. Magnitudes of the standard deviation of the differences in surface wind speed range from approximately 2 to 4 m/sec, and satellite derived surface winds are able to depict flow across a cold front and around a low pressure center.

Wind Tails Near Chimp

NASA Technical Reports Server (NTRS)

1997-01-01

This image of the rock 'Chimp' was taken by the Sojourner rover's right front camera on Sol 72 (September 15). Fine-scale texture on Chimp and other rocks is clearly visible. Wind tails, oriented from lower right to upper left, are seen next to small pebbles in the foreground. These were most likely produced by wind action.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Stator for a rotating electrical machine having multiple control windings

DOEpatents

Shah, Manoj R.; Lewandowski, Chad R.

2001-07-17

A rotating electric machine is provided which includes multiple independent control windings for compensating for rotor imbalances and for levitating/centering the rotor. The multiple independent control windings are placed at different axial locations along the rotor to oppose forces created by imbalances at different axial locations along the rotor. The multiple control windings can also be used to levitate/center the rotor with a relatively small magnetic field per unit area since the rotor and/or the main power winding provides the bias field.

IEA Wind Task 26 - Multi-national Case Study of the Financial Cost of Wind Energy; Work Package 1 Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwabe, P.; Lensink, S.; Hand, M.

2011-03-01

The lifetime cost of wind energy is comprised of a number of components including the investment cost, operation and maintenance costs, financing costs, and annual energy production. Accurate representation of these cost streams is critical in estimating a wind plant's cost of energy. Some of these cost streams will vary over the life of a given project. From the outset of project development, investors in wind energy have relatively certain knowledge of the plant's lifetime cost of wind energy. This is because a wind energy project's installed costs and mean wind speed are known early on, and wind generation generallymore » has low variable operation and maintenance costs, zero fuel cost, and no carbon emissions cost. Despite these inherent characteristics, there are wide variations in the cost of wind energy internationally, which is the focus of this report. Using a multinational case-study approach, this work seeks to understand the sources of wind energy cost differences among seven countries under International Energy Agency (IEA) Wind Task 26 - Cost of Wind Energy. The participating countries in this study include Denmark, Germany, the Netherlands, Spain, Sweden, Switzerland, and the United States. Due to data availability, onshore wind energy is the primary focus of this study, though a small sample of reported offshore cost data is also included.« less

Effects of tailoring health messages on physical activity.

PubMed

Smeets, Tamara; Brug, J; de Vries, H

2008-06-01

Computer-tailored printed education can be a promising way of promoting physical activity. The present study tested whether computer-tailored feedback on physical activity is effective and whether there are differences between respondents with low and high motivation to change. Respondents (n = 487) were randomly assigned to a tailored intervention group or a no information control group. Physical activity and determinants were measured at baseline and after 3 months. At post-test, the motivated respondents in the control group were more likely not to meet the recommendation for physical activity than to meet it, and motivated respondents in the experimental group were more likely to engage in transport-related activities and showed more improvement over time for the total activity score than respondents in the control group (beta = 0.24, P = 0.02). Both groups improved their behaviour over time. No group differences in physical activity were found for the unmotivated respondents. The results showed that the effects of the tailored feedback were restricted to respondents who had a positive motivation to change at baseline. Possible explanations could be that unmotivated respondents were unwilling to read and process the information because they felt 'no need to change'. Alternatively, one tailored feedback letter may not have been sufficient for this unmotivated group.

Low cost composite materials for wind energy conversion systems

NASA Technical Reports Server (NTRS)

Weingart, O.

1980-01-01

A winding process utilizing a low-cost E-glass fabric called transverse-filament tape for low-cost production of wind turbine generators (WTG) is described. The process can be carried out continuously at high speed to produce large one-piece parts with tapered wall thicknesses on a tapered mandrel. It is being used to manufacture blades for the NASA/DOE 200-ft-diameter MOD-1 WTG and Rockwell/DOE 40-kW small wind energy conversion system (SWECS).

Tailoring of EIA-649-1: Definition of Major (Class I) Engineering Change Proposal

DTIC Science & Technology

2015-05-15

MISSILE SYSTEMS CENTER TAILORING TAILORING OF EIA -649-1: DEFINITION OF MAJOR (CLASS I) ENGINEERING CHANGE PROPOSAL APPROVED FOR...PUBLIC RELEASE; DISTRIBUTION IS UNLIMITED 1 Tailoring of EIA -649-1: Definition of Major (Class I) ECP. 1. Intent of this Tailoring Document...This tailoring document remedies a requirements gap in the industry consensus standard, EIA -649-1: 2015. Specifically, this tailoring provides a

Further investigations of the aeroelastic behavior of the AFW wind-tunnel model using transonic small disturbance theory

NASA Technical Reports Server (NTRS)

Silva, Walter A.; Bennett, Robert M.

1992-01-01

The Computational Aeroelasticity Program-Transonic Small Disturbance (CAP-TSD) code, developed at LaRC, is applied to the active flexible wing wind-tunnel model for prediction of transonic aeroelastic behavior. A semi-span computational model is used for evaluation of symmetric motions, and a full-span model is used for evaluation of antisymmetric motions, and a full-span model is used for evaluation of antisymmetric motions. Static aeroelastic solutions using CAP-TSD are computed. Dynamic deformations are presented as flutter boundaries in terms of Mach number and dynamic pressure. Flutter boundaries that take into account modal refinements, vorticity and entropy corrections, antisymmetric motion, and sensitivity to the modeling of the wing tip ballast stores are also presented with experimental flutter results.

77 FR 29633 - Alta Wind VII, LLC, Alta Wind IX, LLC, Alta Wind X, LLC, Alta Wind XI, LLC, Alta Wind XII, LLC...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-18

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL12-68-000] Alta Wind VII, LLC, Alta Wind IX, LLC, Alta Wind X, LLC, Alta Wind XI, LLC, Alta Wind XII, LLC, Alta Wind XIII, LLC, Alta Wind XIV, LLC, Alta Wind XV, LLC, Alta Windpower Development, LLC, TGP Development Company, LLC...

75 FR 23263 - Alta Wind I, LLC; Alta Wind II, LLC; Alta Wind III, LLC; Alta Wind IV, LLC; Alta Wind V, LLC...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-03

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL10-62-000] Alta Wind I, LLC; Alta Wind II, LLC; Alta Wind III, LLC; Alta Wind IV, LLC; Alta Wind V, LLC; Alta Wind VI, LLC; Alta Wind VII, LLC; Alta Wind VIII, LLC; Alta Windpower Development, LLC; TGP Development Company, LLC...

Tailoring magnetic properties of Co nanocluster assembled films using hydrogen

NASA Astrophysics Data System (ADS)

Romero, C. P.; Volodin, A.; Paddubrouskaya, H.; Van Bael, M. J.; Van Haesendonck, C.; Lievens, P.

2018-07-01

Tailoring magnetic properties in nanocluster assembled cobalt (Co) thin films was achieved by admitting a small percentage of H2 gas (∼2%) into the Co gas phase cluster formation chamber prior to deposition. The oxygen content in the films is considerably reduced by the presence of hydrogen during the cluster formation, leading to enhanced magnetic interactions between clusters. Two sets of Co samples were fabricated, one without hydrogen gas and one with hydrogen gas. Magnetic properties of the non-hydrogenated and the hydrogen-treated Co nanocluster assembled films are comparatively studied using magnetic force microscopy and vibrating sample magnetometry. When comparing the two sets of samples the considerably larger coercive field of the H2-treated Co nanocluster film and the extended micrometer-sized magnetic domain structure confirm the enhancement of magnetic interactions between clusters. The thickness of the antiferromagnetic CoO layer is controlled with this procedure and modifies the exchange bias effect in these films. The exchange bias shift is lower for the H2-treated Co nanocluster film, which indicates that a thinner antiferromagnetic CoO reduces the coupling with the ferromagnetic Co. The hydrogen-treatment method can be used to tailor the oxidation levels thus controlling the magnetic properties of ferromagnetic cluster-assembled films.

Cogging Torque Reduction in a Permanent Magnet Wind Turbine Generator: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muljadi, E.; Green, J.

2002-01-01

In this paper, we investigate three design options to minimize cogging torque: uniformity of air gap, pole width, and skewing. Although the design improvement is intended for small wind turbines, it is also applicable to larger wind turbines.

Wind-waves interactions in the Gulf of Eilat

NASA Astrophysics Data System (ADS)

Shani-Zerbib, Almog; Liberzon, Dan; T-SAIL Team

2017-11-01

The Gulf of Eilat, at the southern tip of Israel, with its elongated rectangular shape and unique diurnal wind pattern is an appealing location for wind-waves interactions research. Results of experimental work will be reported analyzing a continuous, 50 hour long, data. Using a combined array of wind and waves sensing instruments, the wave field statistics and its response to variations of wind forcing were investigated. Correlations between diurnal fluctuations in wind magnitude and direction and the wave field response will be discussed. The directional spread of waves' energy, as estimated by the Wavelet Directional Method, showed a strong response to small variations in wind flow direction attributed to the unique topography of the gulf surroundings and its bathymetry. Influenced by relatively strong winds during the light hours, the wave field was dominated by a significant amount of breakings that are well pronounced in the saturation range of waves spectra. Temporal growth and decay behavior of the waves during the morning and evening wind transition periods was examined. Sea state induced roughness, as experienced by the wind flow turbulent boundary layer, is examined in view of the critical layer theory. Israel Science Foundation Grant # 1521/15.

Frequency of dry east winds over northwest Oregon and southwest Washington.

Treesearch

Owen P. Cramer

1957-01-01

There is a close relation between occurrences of severe easterly winds and large forest fires in northwest Oregon and southwest Washington. With the east winds comes the dreaded combination of low humidity and high wind that in the past has whipped small fires into conflagrations such as the Tillamook fire of 1933 and the fire that burned Bandon in 1936. These easterly...

Tailored Web-Based Interventions for Pain: Systematic Review and Meta-Analysis.

PubMed

Martorella, Geraldine; Boitor, Madalina; Berube, Melanie; Fredericks, Suzanne; Le May, Sylvie; Gélinas, Céline

2017-11-10

list, tailored Web-based intervention showed benefits immediately after, with small effect sizes (<0.40) for pain intensity (10 randomized controlled trials [RCTs], n=1310, P=.003) and pain-related disability (6 RCTs, n=953, P<.001). No other improvements were observed at follow-up in the medium and long terms. Compared with the active control group, no improvements were found for the primary outcome (pain intensity) or any of the outcomes except for a small effect size on pain catastrophizing (2 RCTs, n=333, P<.001) immediately after the intervention. Tailored Web-based interventions did not prove to be more efficacious than standardized Web-based interventions in terms of pain intensity, pain-related disability, anxiety, and depression. An interesting finding was that some efficacy was shown on pain catastrophizing compared with active control interventions. Considering the diversity of approaches used in tailored Web-based interventions for chronic pain management, their efficacy is yet to be explored. Moreover, their contribution to acute pain management is embryonic. International prospective register of systematic reviews (PROSPERO): CRD42015027669; http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42015027669 (Archived by WebCite at http://www. webcitation.org/6uneWAuyR). ©Geraldine Martorella, Madalina Boitor, Melanie Berube, Suzanne Fredericks, Sylvie Le May, Céline Gélinas. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 10.11.2017.

Control of large wind turbine generators connected to utility networks

NASA Technical Reports Server (NTRS)

Hinrichsen, E. N.

1983-01-01

This is an investigation of the control requirements for variable pitch wind turbine generators connected to electric power systems. The requirements include operation in very small as well as very large power systems. Control systems are developed for wind turbines with synchronous, induction, and doubly fed generators. Simulation results are presented. It is shown how wind turbines and power system controls can be integrated. A clear distinction is made between fast control of turbine torque, which is a peculiarity of wind turbines, and slow control of electric power, which is a traditional power system requirement.

Web-based tailored nutrition education: results of a randomized controlled trial.

PubMed

Oenema, A; Brug, J; Lechner, L

2001-12-01

There is ample evidence that printed, computer-tailored nutrition education is a more effective tool for motivating people to change to healthier diets than general nutrition education. New technology is now providing more advanced ways of delivering tailored messages, e.g. via the World Wide Web (WWW). Before disseminating a tailored intervention via the web, it is important to investigate the potential of web-based tailored nutrition education. The present study investigated the immediate impact of web-based computer-tailored nutrition education on personal awareness and intentions related to intake of fat, fruit and vegetables. A randomized controlled trial, with a pre-test-post-test control group design was conducted. Significant differences in awareness and intention to change were found between the intervention and control group at post-test. The tailored intervention was appreciated better, was rated as more personally relevant, and had more subjective impact on opinion and intentions to change than the general nutrition information. Computer literacy had no effect on these ratings. The results indicate that interactive, web-based computer-tailored nutrition education can lead to changes in determinants of behavior. Future research should be aimed at longer-term (behavioral) effects and the practicability of distributing tailored interventions via the WWW.

Metal Matrix Laminate Tailoring (MMLT) code: User's manual

NASA Technical Reports Server (NTRS)

Murthy, P. L. N.; Morel, M. R.; Saravanos, D. A.

1993-01-01

The User's Manual for the Metal Matrix Laminate Tailoring (MMLT) program is presented. The code is capable of tailoring the fabrication process, constituent characteristics, and laminate parameters (individually or concurrently) for a wide variety of metal matrix composite (MMC) materials, to improve the performance and identify trends or behavior of MMC's under different thermo-mechanical loading conditions. This document is meant to serve as a guide in the use of the MMLT code. Detailed explanations of the composite mechanics and tailoring analysis are beyond the scope of this document, and may be found in the references. MMLT was developed by the Structural Mechanics Branch at NASA Lewis Research Center (LeRC).

Energy Primer: Solar, Water, Wind, and Biofuels.

ERIC Educational Resources Information Center

Portola Inst., Inc., Menlo Park, CA.

This is a comprehensive, fairly technical book about renewable forms of energy--solar, water, wind, and biofuels. The biofuels section covers biomass energy, agriculture, aquaculture, alcohol, methane, and wood. The focus is on small-scale systems which can be applied to the needs of the individual, small group, or community. More than one-fourth…

Neural correlates of message tailoring and self-relatedness in smoking cessation programming.

PubMed

Chua, Hannah Faye; Liberzon, Israel; Welsh, Robert C; Strecher, Victor J

2009-01-15

Smoking leads to illnesses including addiction, cancer, and cardiovascular and respiratory diseases. Different intervention programs have become available. In the past decade, providing tailored smoking cessation messages has been shown to be more effective in inducing smoking cessation than one-size-fits-all interventions. However, little is known about the brain responses of smokers when they receive tailored smoking cessation messages. A neuroimaging study using blocked and event-related designs examined neural activity in 24 smokers exposed to high-tailored and low-tailored smoking cessation messages. In both blocked and event-related conditions, rostral medial prefrontal cortex and precuneus/posterior cingulate were engaged more during the processing of high-tailored smoking cessation messages than low-tailored smoking cessation messages. The activation patterns of smokers to tailored cessation messages show involvement of brain areas commonly implicated in self-related processing. Results seem to add support to the suggested role of self-relevance in tailored cessation programs, where previous studies have shown a potential mediating role of self-relevance on smoking abstinence. The findings are relevant to understanding the cognitive mechanisms underlying tailored message processing and might point to new directions for testing response to health communications programming.

Climatology of Neutral vertical winds in the midlatitude thermosphere

NASA Astrophysics Data System (ADS)

Kerr, R.; Kapali, S.; Riccobono, J.; Migliozzi, M. A.; Noto, J.; Brum, C. G. M.; Garcia, R.

2017-12-01

More than one thousand measurements of neutral vertical winds, relative to an assumed average of 0 m/s during a nighttime period, have been made at Arecibo Observatory and the Millstone Hill Optical Facility since 2012, using imaging Fabry-Perot interferometers. These instruments, tuned to the 630 nm OI emission, are carefully calibrated for instrumental frequency drift using frequency stabilized lasers, allowing isolation of Doppler motion in the zenith with 1-2 m/s accuracy. As one example of the results, relative vertical winds at Arecibo during quiet geomagnetic conditions near winter solstice 2016, range ±70 m/s and have a one standard deviation statistical variability of ±34 m/s. This compares with a ±53 m/s deviation from the average meridional wind, and a ±56 m/s deviation from the average zonal wind measured during the same period. Vertical neutral wind velocities for all periods range from roughly 30% - 60% of the horizontal velocity domain at Arecibo. At Millstone Hill, the vertical velocities relative to horizontal velocities are similar, but slightly smaller. The midnight temperature maximum at Arecibo is usually correlated with a surge in the upward wind, and vertical wind excursions of more than 80 m/s are common during magnetic storms at both sites. Until this compilation of vertical wind climatology, vertical motions of the neutral atmosphere outside of the auroral zone have generally been assumed to be very small compared to horizontal transport. In fact, excursions from small vertical velocities in the mid-latitude thermosphere near the F2 ionospheric peak are common, and are not isolated events associated with unsettled geomagnetic conditions or other special dynamic conditions.

Wind gusts and plant aeroelasticity effects on the aerodynamics of pollen shedding: a hypothetical turbulence-initiated wind-pollination mechanism.

PubMed

Urzay, Javier; Llewellyn Smith, Stefan G; Thompson, Elinor; Glover, Beverley J

2009-08-21

Plant reproduction depends on pollen dispersal. For anemophilous (wind-pollinated) species, such as grasses and many trees, shedding pollen from the anther must be accomplished by physical mechanisms. The unknown nature of this process has led to its description as the 'paradox of pollen liberation'. A simple scaling analysis, supported by experimental measurements on typical wind-pollinated plant species, is used to estimate the suitability of previous resolutions of this paradox based on wind-gust aerodynamic models of fungal-spore liberation. According to this scaling analysis, the steady Stokes drag force is found to be large enough to liberate anemophilous pollen grains, and unsteady boundary-layer forces produced by wind gusts are found to be mostly ineffective since the ratio of the characteristic viscous time scale to the inertial time scale of acceleration of the wind stream is a small parameter for typical anemophilous species. A hypothetical model of a stochastic aeroelastic mechanism, initiated by the atmospheric turbulence typical of the micrometeorological conditions in the vicinity of the plant, is proposed to contribute to wind pollination.

Diode Laser Assisted Filament Winding of Thermoplastic Matrix Composites

PubMed Central

Quadrini, Fabrizio; Squeo, Erica Anna; Prosperi, Claudia

2010-01-01

A new consolidation method for the laser-assisted filament winding of thermoplastic prepregs is discussed: for the first time a diode laser is used, as well as long glass fiber reinforced polypropylene prepregs. A consolidation apparatus was built by means of a CNC motion table, a stepper motor and a simple tensioner. Preliminary tests were performed in a hoop winding configuration: only the winding speed was changed, and all the other process parameters (laser power, distance from the laser focus, consolidation force) were kept constant. Small wound rings with an internal diameter of 25 mm were produced and compression tests were carried out to evaluate the composite agglomeration in dependence of the winding speed. At lower winding speeds, a strong interpenetration of adjacent layers was observed.

A global wind resource atlas including high-resolution terrain effects

NASA Astrophysics Data System (ADS)

Hahmann, Andrea; Badger, Jake; Olsen, Bjarke; Davis, Neil; Larsen, Xiaoli; Badger, Merete

2015-04-01

Currently no accurate global wind resource dataset is available to fill the needs of policy makers and strategic energy planners. Evaluating wind resources directly from coarse resolution reanalysis datasets underestimate the true wind energy resource, as the small-scale spatial variability of winds is missing. This missing variability can account for a large part of the local wind resource. Crucially, it is the windiest sites that suffer the largest wind resource errors: in simple terrain the windiest sites may be underestimated by 25%, in complex terrain the underestimate can be as large as 100%. The small-scale spatial variability of winds can be modelled using novel statistical methods and by application of established microscale models within WAsP developed at DTU Wind Energy. We present the framework for a single global methodology, which is relative fast and economical to complete. The method employs reanalysis datasets, which are downscaled to high-resolution wind resource datasets via a so-called generalization step, and microscale modelling using WAsP. This method will create the first global wind atlas (GWA) that covers all land areas (except Antarctica) and 30 km coastal zone over water. Verification of the GWA estimates will be done at carefully selected test regions, against verified estimates from mesoscale modelling and satellite synthetic aperture radar (SAR). This verification exercise will also help in the estimation of the uncertainty of the new wind climate dataset. Uncertainty will be assessed as a function of spatial aggregation. It is expected that the uncertainty at verification sites will be larger than that of dedicated assessments, but the uncertainty will be reduced at levels of aggregation appropriate for energy planning, and importantly much improved relative to what is used today. In this presentation we discuss the methodology used, which includes the generalization of wind climatologies, and the differences in local and spatially

On the properties of energy transfer in solar wind turbulence.

NASA Astrophysics Data System (ADS)

Sorriso-Valvo, Luca; Marino, Raffaele; Chen, Christopher H. K.; Wicks, Robert; Nigro, Giuseppina

2017-04-01

Spacecraft observations have shown that the solar wind plasma is heated during its expansion in the heliosphere. The necessary energy is made available at small scales by a turbulent cascade, although the nature of the heating processes is still debated. Because of the intermittent nature of turbulence, the small-scale energy is inhomogeneously distributed in space, resulting for example in the formation of highly localized current sheets and eddies. In order to understand the small-scale plasma processes occurring in the solar wind, the global and local properties of such energy distribution must be known. Here we study such properties using a proxy derived from the Von Karman-Howart relation for magnetohydrodynamics. The statistical properties of the energy transfer rate in the fluid range of scales are studied in detail using WIND spacecraft plasma and magnetic field measurements and discussed in the framework of the multifractal turbulent cascade. Dependence of the energy dissipation proxy on the solar wind conditions (speed, type, solar activity...) is analysed, and its evolution during solar wind expansion in the heliosphere is described using Helios II and Ulysses measurements. A comparison with other proxies, such as the PVI, is performed. Finally, the local singularity properties of the energy dissipation proxy are conditionally compared to the corresponding particle velocity distributions. This allows the identification of specific plasma features occurring near turbulent dissipation events, and could be used as enhanced mode trigger in future space missions.

Feasibility study of wind-generated electricity for rural applications in southwestern Ohio

NASA Astrophysics Data System (ADS)

Kohring, G. W.

The parameters associated with domestic production of wind generated electricity for direct use by small farms and rural homes in the southwestern Ohio region are discussed. The project involves direct utility interfaced electricity generation from a horizontal axis, down-wind, fixed pitch, wind powered induction generator system. Goals of the project are to determine: the ability to produce useful amounts of domestic wind generated electricity in the southwestern Ohio region; economic justification for domestic wind generated electrical production; and the potential of domestic wind generated electricity for reducing dependence on non-renewable energy resources in the southwestern Ohio region.

EDITORIAL: Wind energy

NASA Astrophysics Data System (ADS)

Mann, Jakob; Nørkær Sørensen, Jens; Morthorst, Poul-Erik

2008-01-01

addressed within the issue is how much conventional power production can be replaced by the ceaseless wind, with the question of how Greece's target of 29% renewables by 2020 is to be met efficiently. Other topics include an innovative way to determine the power curve of a turbine experimentally more accurately, the use of fluid dynamics tools to investigate the implications of placing vortex generators on wind turbine blades (thereby possibly improving their efficiency) and a study of the perception of wind turbine noise. It turns out that a small but significant fraction of wind turbine neighbours feel that turbine generated noise impairs their ability to rest. The annoyance is correlated with a negative attitude towards the visual impact on the landscape, but what is cause and effect is too early to say. As mentioned there is a rush for wind turbines in many countries. However, this positive development for the global climate is currently limited by practical barriers. One bottleneck is the difficulties for the sub-suppliers of gears and other parts to meet the demand. Another is the difficulties to meet the demand for engineers specialized in wind. For that reason the Technical University of Denmark (DTU) recently launched the world's first Wind Energy Masters Program. Here and elsewhere in the world of wind education and research we should really speed up now, as our chances of contributing to emission free energy production and a healthier global climate have never been better. Focus on Wind Energy Contents The articles below represent the first accepted contributions and further additions will appear in the near future. Wind turbines—low level noise sources interfering with restoration? Eja Pedersen and Kerstin Persson Waye On the effect of spatial dispersion of wind power plants on the wind energy capacity credit in Greece George Caralis, Yiannis Perivolaris, Konstantinos Rados and Arthouros Zervos Large-eddy simulation of spectral coherence in a wind turbine wake

Wind Resource Assessment | Wind | NREL

Science.gov Websites

Resource Assessment Wind Resource Assessment A map of the United States is color-coded to indicate the high winds at 80 meters. This map shows the wind resource at 80 meters for both land-based and offshore wind resources in the United States. Correct estimation of the energy available in the wind can

Web-Based Video-Coaching to Assist an Automated Computer-Tailored Physical Activity Intervention for Inactive Adults: A Randomized Controlled Trial.

PubMed

Alley, Stephanie; Jennings, Cally; Plotnikoff, Ronald C; Vandelanotte, Corneel

2016-08-12

engagement (110 minutes spent on the website vs 78 minutes, P=.02) compared with other participants. There were no overall retention, adherence, engagement, and satisfaction differences between tailoring + video-coaching and tailoring-only participants. At 9 weeks, physical activity increased from baseline to postintervention in all groups (tailoring + video-coaching: +150 minutes/week; tailoring only: +123 minutes/week; waitlist control: +34 minutes/week). The increase was significantly higher in the tailoring + video-coaching group compared with the control group (P=.01). No significant difference was found between intervention groups and no significant between-group differences were found for physical activity change at 6 months. Only small improvements were observed when video-coaching was added to computer-tailored advice in a Web-based physical activity intervention. However, combined Web-based video-coaching and computer-tailored advice was effective in comparison with a control group. More research is needed to determine whether Web-based coaching is more effective than stand-alone computer-tailored advice. Australian New Zealand Clinical Trials Registry (ACTRN): 12614000339651; http://www.anzctr.org.au/TrialSearch.aspx?searchTxt=ACTRN12614000339651+&isBasic=True (Archived by WebCite at http://www.webcitation.org/6jTnOv0Ld).

Small scale wind tunnel model investigation of hybrid high lift systems combining upper surface blowing with the internally blown flap

NASA Technical Reports Server (NTRS)

Waites, W. L.; Chin, Y. T.

1974-01-01

A small-scale wind tunnel test of a two engine hybrid model with upper surface blowing on a simulated expandable duct internally blown flap was accomplished in a two phase program. The low wing Phase I model utilized 0.126c radius Jacobs/Hurkamp flaps and 0.337c radius Coanda flaps. The high wing Phase II model was utilized for continued studies on the Jacobs/Hurkamp flap. Principal study areas included: basic data both engines operative and with an engine out, control flap utilization, horizontal tail effectiveness, spoiler effectiveness, USB nacelle deflector study and USB/IBF pressure ratio effects.

3D Anisotropy of Solar Wind Turbulence, Tubes, or Ribbons?

NASA Astrophysics Data System (ADS)

Verdini, Andrea; Grappin, Roland; Alexandrova, Olga; Lion, Sonny

2018-01-01

We study the anisotropy with respect to the local magnetic field of turbulent magnetic fluctuations at magnetofluid scales in the solar wind. Previous measurements in the fast solar wind obtained axisymmetric anisotropy, despite that the analysis method allows nonaxisymmetric structures. These results are probably contaminated by the wind expansion that introduces another symmetry axis, namely, the radial direction, as indicated by recent numerical simulations. These simulations also show that while the expansion is strong, the principal fluctuations are in the plane perpendicular to the radial direction. Using this property, we separate 11 yr of Wind spacecraft data into two subsets characterized by strong and weak expansion and determine the corresponding turbulence anisotropy. Under strong expansion, the small-scale anisotropy is consistent with the Goldreich & Sridhar critical balance. As in previous works, when the radial symmetry axis is not eliminated, the turbulent structures are field-aligned tubes. Under weak expansion, we find 3D anisotropy predicted by the Boldyrev model, that is, turbulent structures are ribbons and not tubes. However, the very basis of the Boldyrev phenomenology, namely, a cross-helicity increasing at small scales, is not observed in the solar wind: the origin of the ribbon formation is unknown.

78 FR 29364 - Exelon Corporation, Exelon Wind 1, LLC, Exelon Wind 2, LLC, Exelon Wind 3, LLC, Exelon Wind 4...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-20

...-005, QF07-55-005, QF07-56-005, QF07-257-004] Exelon Corporation, Exelon Wind 1, LLC, Exelon Wind 2, LLC, Exelon Wind 3, LLC, Exelon Wind 4, LLC, Exelon Wind 5, LLC, Exelon Wind 6, LLC, Exelon Wind 7, LLC, Exelon Wind 8, LLC, Exelon Wind 9, LLC, Exelon Wind 10, LLC, Exelon Wind 11, LLC, High Plains...

Neural correlates of message tailoring and self-relatedness in smoking cessation programming

PubMed Central

Chua, Hannah Faye; Liberzon, Israel; Welsh, Robert C.; Strecher, Victor J.

2011-01-01

BACKGROUND Smoking leads to illnesses including addiction, cancer, and cardiovascular and respiratory diseases. Different intervention programs have become available. In the past decade, providing tailored smoking cessation messages has been shown to be more effective in inducing smoking cessation than one-size-fits-all interventions. However, little is known about the brain responses of smokers when they receive tailored smoking cessation messages. METHODS A neuroimaging study using blocked and event-related designs examined neural activity in 24 smokers exposed to high-tailored and low-tailored smoking cessation messages. RESULTS: In both blocked and event-related conditions, rostral medial prefrontal cortex and precuneus/posterior cingulate were engaged more during the processing of high-tailored smoking cessation messages than low-tailored smoking cessation messages. CONCLUSION The activation patterns of smokers to tailored cessation messages show involvement of brain areas commonly implicated in self-related processing. Results seem to add support to the suggested role of self-relevance in tailored cessation programs, where previous studies have shown a potential mediating role of self-relevance on smoking abstinence. The findings are relevant to understanding the cognitive mechanisms underlying tailored message processing and may point to new directions for testing response to health communications programming. PMID:18926523

Simulation and experiment of a fuzzy logic based MPPT controller for a small wind turbine system

NASA Astrophysics Data System (ADS)

Petrila, Diana; Muntean, Nicolae

2012-09-01

This paper describes the development of a fuzzy logic based maximum power point tracking (MPPT) strategy for a variable speed wind turbine system (VSWT). For this scope, a fuzzy logic controller (FLC) was described, simulated and tested on a real time "hardware in the loop" wind turbine emulator. Simulation and experimental results show that the controller is able to track the maximum power point for various wind conditions and validate the proposed control strategy.

Predicting Near-surface Winds with WindNinja for Wind Energy Applications

NASA Astrophysics Data System (ADS)

Wagenbrenner, N. S.; Forthofer, J.; Shannon, K.; Butler, B.

2016-12-01

WindNinja is a high-resolution diagnostic wind model widely used by operational wildland fire managers to predict how near-surface winds may influence fire behavior. Many of the features which have made WindNinja successful for wildland fire are also important for wind energy applications. Some of these features include flexible runtime options which allow the user to initialize the model with coarser scale weather model forecasts, sparse weather station observations, or a simple domain-average wind for what-if scenarios; built-in data fetchers for required model inputs, including gridded terrain and vegetation data and operational weather model forecasts; relatively fast runtimes on simple hardware; an extremely user-friendly interface; and a number of output format options, including KMZ files for viewing in Google Earth and GeoPDFs which can be viewed in a GIS. The recent addition of a conservation of mass and momentum solver based on OpenFOAM libraries further increases the utility of WindNinja to modelers in the wind energy sector interested not just in mean wind predictions, but also in turbulence metrics. Here we provide an evaluation of WindNinja forecasts based on (1) operational weather model forecasts and (2) weather station observations provided by the MesoWest API. We also compare the high-resolution WindNinja forecasts to the coarser operational weather model forecasts. For this work we will use the High Resolution Rapid Refresh (HRRR) model and the North American Mesoscale (NAM) model. Forecasts will be evaluated with data collected in the Birch Creek valley of eastern Idaho, USA between June-October 2013. Near-surface wind, turbulence data, and vertical wind and temperature profiles were collected at very high spatial resolution during this field campaign specifically for use in evaluating high-resolution wind models like WindNinja. This work demonstrates the ability of WindNinja to generate very high-resolution wind forecasts for wind energy

Amplification of nonlinear surface waves by wind

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leblanc, Stephane

2007-10-15

A weakly nonlinear analysis is conducted to study the evolution of slowly varying wavepackets with small but finite amplitudes, that evolve at the interface between air and water under the effect of wind. In the inviscid assumption, wave envelopes are governed by cubic nonlinear Schroedinger or Davey-Stewartson equations forced by a linear term corresponding to Miles' mechanism of wave generation. Under fair wind, it is shown that Stokes waves grow exponentially and that Benjamin-Feir instability becomes explosive.

Active Power Control of Waked Wind Farms: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fleming, Paul A; van Wingerden, Jan-Willem; Pao, Lucy

Active power control can be used to balance the total power generated by wind farms with the power consumed on the electricity grid. With the increasing penetration levels of wind energy, there is an increasing need for this ancillary service. In this paper, we show that the tracking of a certain power reference signal provided by the transmission system operator can be significantly improved by using feedback control at the wind farm level. We propose a simple feedback control law that significantly improves the tracking behavior of the total power output of the farm, resulting in higher performance scores. Themore » effectiveness of the proposed feedback controller is demonstrated using high-fidelity computational fluid dynamics simulations of a small wind farm.« less

A Taguchi study of the aeroelastic tailoring design process

NASA Technical Reports Server (NTRS)

Bohlmann, Jonathan D.; Scott, Robert C.

1991-01-01

A Taguchi study was performed to determine the important players in the aeroelastic tailoring design process and to find the best composition of the optimization's objective function. The Wing Aeroelastic Synthesis Procedure (TSO) was used to ascertain the effects that factors such as composite laminate constraints, roll effectiveness constraints, and built-in wing twist and camber have on the optimum, aeroelastically tailored wing skin design. The results show the Taguchi method to be a viable engineering tool for computational inquiries, and provide some valuable lessons about the practice of aeroelastic tailoring.

Wind speed affects prey-catching behaviour in an orb web spider.

PubMed

Turner, Joe; Vollrath, Fritz; Hesselberg, Thomas

2011-12-01

Wind has previously been shown to influence the location and orientation of spider web sites and also the geometry and material composition of constructed orb webs. We now show that wind also influences components of prey-catching behaviour within the web. A small wind tunnel was used to generate different wind speeds. Araneus diadematus ran more slowly towards entangled Drosophila melanogaster in windy conditions, which took less time to escape the web. This indicates a lower capture probability and a diminished overall predation efficiency for spiders at higher wind speeds. We conclude that spiders' behaviour of taking down their webs as wind speed increases may therefore not be a response only to possible web damage.

Wind speed affects prey-catching behaviour in an orb web spider

NASA Astrophysics Data System (ADS)

Turner, Joe; Vollrath, Fritz; Hesselberg, Thomas

2011-12-01

Wind has previously been shown to influence the location and orientation of spider web sites and also the geometry and material composition of constructed orb webs. We now show that wind also influences components of prey-catching behaviour within the web. A small wind tunnel was used to generate different wind speeds. Araneus diadematus ran more slowly towards entangled Drosophila melanogaster in windy conditions, which took less time to escape the web. This indicates a lower capture probability and a diminished overall predation efficiency for spiders at higher wind speeds. We conclude that spiders' behaviour of taking down their webs as wind speed increases may therefore not be a response only to possible web damage.

Star birth with a chance of Winds?

NASA Image and Video Library

2017-12-08

The lesser-known constellation of Canes Venatici (The Hunting Dogs), is home to a variety of deep-sky objects — including this beautiful galaxy, known as NGC 4861. Astronomers are still debating on how to classify it. While its physical properties — such as mass, size and rotational velocity — indicate it to be a spiral galaxy, its appearance looks more like a comet with its dense, luminous “head” and dimmer “tail” trailing off. Features more fitting with a dwarf irregular galaxy. Although small and messy, galaxies like NGC 4861 provide astronomers with interesting opportunities for study. Small galaxies have lower gravitational potentials, which simply means that it takes less energy to move stuff about inside them than it does in other galaxies. As a result, moving in, around, and through such a tiny galaxy is quite easy to do, making them far more likely to be filled with streams and outflows of speedy charged particles known as galactic winds, which can flood such galaxies with little effort. These galactic winds can be powered by the ongoing process of star formation, which involves huge amounts of energy. New stars are springing into life within the bright, colorful ‘head’ of NGC 4861 and ejecting streams of high-speed particles as they do so, which flood outwards to join the wider galactic wind. While NGC 4861 would be a perfect candidate to study such winds, recent studies did not find any galactic winds in it. Image credit: ESA/Hubble & NASA

Distribution and solar wind control of compressional solar wind-magnetic anomaly interactions observed at the Moon by ARTEMIS

NASA Astrophysics Data System (ADS)

Halekas, J. S.; Poppe, A. R.; Lue, C.; Farrell, W. M.; McFadden, J. P.

2017-06-01

A statistical investigation of 5 years of observations from the two-probe Acceleration, Reconnection, Turbulence, and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) mission reveals that strong compressional interactions occur infrequently at high altitudes near the ecliptic but can form in a wide range of solar wind conditions and can occur up to two lunar radii downstream from the lunar limb. The compressional events, some of which may represent small-scale collisionless shocks ("limb shocks"), occur in both steady and variable interplanetary magnetic field (IMF) conditions, with those forming in steady IMF well organized by the location of lunar remanent crustal magnetization. The events observed by ARTEMIS have similarities to ion foreshock phenomena, and those observed in variable IMF conditions may result from either local lunar interactions or distant terrestrial foreshock interactions. Observed velocity deflections associated with compressional events are always outward from the lunar wake, regardless of location and solar wind conditions. However, events for which the observed velocity deflection is parallel to the upstream motional electric field form in distinctly different solar wind conditions and locations than events with antiparallel deflections. Consideration of the momentum transfer between incoming and reflected solar wind populations helps explain the observed characteristics of the different groups of events.