Science.gov (United States)

In the current wind turbine generation system, there are substantial problems such as the maximum power of the wind turbine cannot be obtained under the fluctuating wind speed, high in cost and low in annual net electricity production (due to mismatch between a generator and a wind turbine). A new wind turbine generator optimized for the wind turbine output is presented in order to solve such problems. This wind turbine generator consists of a permanent magnet generator, a reactor and a rectifier, and uses neither a control circuit which requires standby electricity nor a PWM converter having a switching element. By selecting most appropriate combination of the permanent magnet generator having multiple windings and the reactor connected in series with each ...

British Library Electronic Table of Contents (United Kingdom)

The collapsar scenario for long gamma-ray bursts requires rapidly rotating Wolf-Rayet stars as progenitor stars. We highlight two possible ways out of the dilemma that the strong winds of Wolf-Rayet lead to a fast spin-down. One way is to restrict the duration of the Wolf-Rayet phase to a short time span at the end of the star's evolution. We show that this appears to apply to GRB 021004. The other way is to choose a sub-solar metallicity, thus limiting the Wolf-Rayet wind efficiency. We discuss corresponding stellar evolution models and show that a metallicity limit of about 1/10th solar, as it is required by the models, may be consistent with the empirical gamma-ray burst rate.

International Nuclear Information System (INIS)

In order to examine the state of technology of all areas of magnetic suspension and to review related recent developments in sensors and controls approaches, superconducting magnet technology, and design/implementation practices, a symposium was held. The proceedings are presented. The sessions covered the areas of bearings, sensors and controls, microgravity and vibration isolation, superconductivity, manufacturing applications, wind tunnel magnetic suspension systems, magnetically levitated trains (MAGLEV), space applications, and large gap magnetic suspension systems.

International Nuclear Information System (INIS)

The experimental superconducting magnetic system of 0.5 MJ energy storage is described. The step variation of the winding inductance provides a control by the discharge current at the energy output on a high-ohmic load. The voltage on a load is 45 kV at the current 1100 A under the controllable discharge conditions. The energy transfer coefficient constitutes 0,76 under the maximum-to-minimal current ratio equal to 1.3. 7 refs., 3 figs., 2 tabs.

International Nuclear Information System (INIS)

The radio, optical, x-ray and gamma-ray nebulae that surround many pulsars are thought to arise from synchrotron and inverse Compton emission. The energy powering this emission as well as the magnetic fields and relativistic particles are supplied by a 'wind' driven by the central object. The inner parts of the wind can be described using the equations of MHD, but these break down in the outer parts, when the density of charge carriers drops below a critical value. This paper reviews the wave properties of the inner part (striped wind), and uses a relativistic two-fluid model (cold electrons and positrons) to re-examine the nonlinear electromagnetic modes that propagate in the outer parts. It is shown that in a radial wind, two solutions exist for circularly polarized electromagnetic modes. At large distances one of them turns into a freely expanding flow containing a vacuum wave, ...

International Nuclear Information System (INIS)

We study the spectral evolution of pulsar wind nebulae (PWNe) taking into account the energy injected when they are young. We model the evolution of the magnetic field inside a uniformly expanding PWN. Considering time-dependent injection from the pulsar and coolings by radiative and adiabatic losses, we solve the evolution of the particle distribution function. The model is calibrated by fitting the calculated spectrum to the observations of the Crab Nebula at an age of a thousand years. The spectral evolution of the Crab Nebula in our model shows that the flux ratio of TeV #gamma#-rays to X-rays increases with time, which implies that old PWNe are faint in X-rays, but not in TeV #gamma#-rays. The increase of this ratio is because the magnetic field decreases with time and is not because the X-ray emitting particles are cooled more rapidly than the TeV #gamma#-ray emitting particles. Our spectral evolution model matches ...

UK PubMed Central (United Kingdom)

NG2 chondroitin sulfate proteoglycan is a surface marker of oligodendroglial progenitor cells (OPCs) in various species. In contrast to well-studied rat OPCs, however, we found that purified...Full Text Available

International Nuclear Information System (INIS)

Three classes of solar emanations, namely, photon radiation from solar flares, solar energetic particles, and inhomogeneities in the solar wind that drive magnetic storms, are examined, and their effects on humans and technological systems are discussed. Solar flares may disrupt radio communications in the HF and VLF ranges. Energetic particles pose a special hazard at low-earth orbit and above, where they can penetrate barriers such as spacesuits and aluminum and destroy cells and solid state electronics. Energetic solar particles also influence terrestrial radio waves propagating through polar regions. Magnetic storms may disturb the operation of navigation instruments, power lines and pipelines, and satellites; they give rise to ionospheric storms which affect radio communication at all latitudes. There is also a growing body of evidence that changes in the geomagnetic field affect biological systems. 3 refs.

International Nuclear Information System (INIS)

For a number of starless cores, self-absorbed molecular line and column density observations have implied the presence of large-amplitude oscillations. We examine the consequences of these oscillations on the evolution of the cores and the interpretation of their observations. We find that the pulsation energy helps support the cores and that the dissipation of this energy can lead toward instability and star formation. In this picture, the core lifetimes are limited by the pulsation-decay timescales, dominated by non-linear mode-mode coupling, and on the order of #approx =# few x 10"5-10"6 yr. Notably, this is similar to what is required to explain the relatively low rate of conversion of cores into stars. For cores with large-amplitude oscillations, dust continuum observations may appear asymmetric or irregular. As a consequence, some of the cores that would be classified as super-critical may be dynamically stable when oscillations are taken into account. Thus, our investigation ...

CERN Document Server

The 12 GeV upgrade at Jefferson Lab has identified two new large spectrometers as Physics detectors for the project. The first is a 7.5 Gev/c 35 m-sr. spectrometer that requires a pair of identical Combined Function Superconducting Magnets (CFSM) that can simultaneously produce 1.5 T dipole fields and 4.5 T/m quadrupole fields inside a warm bore of 120cm. The second is an 11 GeV/c 2 m-sr. spectrometer that requires a CFSM that simultaneously produces a dipole field of 4.0 T and a quadruple field of 3.0 T/m in a 60 cm warm bore. Magnetic designs using TOSCA 3D have been performed to realize the magnetic requirements, provide 3d fields for optics analysis and produce field and force information for the engineering feasibility of the magnets. A two-sector cos( theta )/cos(2 theta ) design with a low nominal current density, warm bore and warm iron design has been selected and analyzed. These low current ...

Energy Technology Data Exchange (ETDEWEB)

Several short model SSC 50 mm bore dipoles are being built and tested at Fermilab. Mechanical design of these magnets has been determined from experience involved in the construction and testing of 40 mm dipoles. Construction experience includes coil winding, curing and measuring, coil end part design and fabrication, ground insulation, instrumentation, collaring and yoke assembly. Fabrication techniques are explained and construction problems are discussed. Similarities and differences from the 40 mm dipole tooling and management components are outlined. Test results from the first models are presented. 19 refs., 12 figs.

Science.gov (United States)

MAGNETIC FORMING .............. MAGNETIC INDUCTION ............ MAGNETIC MATERIALS ............ MAGNETIC MEASUREMENT .......... MAGNETIC PERMEABILITY . ...

CERN Document Server

We address the deviations of the scaling relations of elliptical galaxies from the expectations based on the virial theorem and homology, including the "tilt" of the "fundamental plane" and the steep decline of density with mass. We show that such tilts result from dissipative major mergers once the gas fraction available for dissipation declines with progenitor mass, and derive the scaling properties of the progenitors. We use hydrodynamical simulations to quantify the effects of major mergers with different gas fractions on the structural properties of galaxies. The tilts are driven by the differential shrinkage of the effective stellar radius as a function of dissipation in the merger, while the correlated smaller enhancements in internal velocity and stellar mass keep the slope of the velocity-stellar mass relation near V \\pr M_*^{1/4}. The progenitors match a straightforward model of disc formation in LCDM haloes. ...

Science.gov (United States)

sive star evolution based on our new calculations of this pulsational instability, where the initial mass of SNe progenitors increases according to the ...

Science.gov (United States)

for massive star evolution, or they could all be very blue super- giant stars experiencing A , = 1-1.5 mag. The fact that the en- ...

UK PubMed Central (United Kingdom)

Cell therapy is a promising novel option for treatment of cardiovascular disease. Because the role of bone marrow-derived circulating progenitor cells (BM-CPCs) after cell therapy is less clear, we...Full Text Available

CERN Document Server

The transition region between the straight part and the ends of the coils of the LHC model and prototype dipole magnets are often identified as the origin of training quenches. In order to study how the discontinuities in the material properties of these regions affect coil pre-stress and possibly gain more insight in the quench behavior, a program was set up at CERN to analyze by 3D-FEM these particular regions. The ACCEL team, who performed a similar analysis for the main quadrupoles of the Superconducting Supercollider SSC, is entrusted with this program. In this paper we report on the results of 3D-modeling and analysis of the coil return end region, including the complete coil mass, of a 1-m single bore model magnet. This magnet represents all relevant features of the "two-in-one" LHC main dipole design concerning the winding configuration, the collar pack, the yoke, and the outer shell ...

International Nuclear Information System (INIS)

We have calculated the on-axis spectrum of spontaneous radiation emitted by an electron moving along a planar undulator that has a magnetic profile along the axis that approximates a square wave. (This could be obtained in practice by driving a ferromagnetic undulator into saturation by excessivecurrent in the windings.) We find considerable enhancement of the harmonic radiation spectrum. We compare the harmonic power emitted by an electron moving through an undulator having a sine-wave field profile with the radiation emitted from an undulator having a square-wave profile; the latter is approximated by the first three Fourier components of the undulator magnetic field profile along the axial direction. Examples are computed for 40MeV electrons taking K1 is greatly enhanced for the approximate square-wave magnetic profile: the ratio of the power emitted at f=5 by the square-wave undulator to that of the ...

CERN Document Server

We propose a new method to measure the metallicity of Type Ia supernova progenitors using Mn and Cr lines in the X-ray spectra of young supernova remnants. We show that the Mn to Cr mass ratio in Type Ia supernova ejecta is tightly correlated with the initial metallicity of the progenitor, as determined by the neutron excess of the white dwarf material before thermonuclear runaway. We use this correlation, together with the flux of the Cr and Mn Kalpha X-ray lines in the Tycho supernova remnant recently detected by Suzaku (Tamagawa et al. 2008) to derive a metallicity of log(Z) = -1.32 (+0.67,-0.33) for the progenitor of this supernova, which corresponds to log(Z/Zsun)= 0.60 (+0.31,-0.60) according to the latest determination of the solar metallicity by Asplund et al. (2005). The uncertainty in the measurement is large, but metallicities much smaller than the solar value can be confidently discarded. We discuss the ...

International Nuclear Information System (INIS)

The downstream failure of cable during winding, insulating, coil winding, and coil assembly is a significant issue in magnet production. The impact of these failures is costly both financially and because of the time needed to recover from them. The current approach to cabling has been to visually inspect the cable for any gross defects during cabling. To date this has been effective in finding small defects such as crossovers, which drastically reduce the mechanical integrity of the strand and thus of the cable itself. But because of the large volume of cable that will be manufactured, an automated flaw detection system that can inspect the cable and detect these types of defects will be needed. We have recently done an on-line experiment using an Eddy current system and specialized Eddy current probes to inspect cable during manufacturing. We will present the results of our inspection, demonstrating detection of ...

Energy Technology Data Exchange (ETDEWEB)

Four 10 MW, highly-stabilized power supply modules have been installed at the National High Magnetic Field Laboratory in Tallahassee, FL, to energize water-cooled, resistive, high-field research magnets. The power supply modules achieve a long term current stability if 10 ppM over a 12 h period with a short term ripple and noise variation of <10 ppM over a time period of one cycle. The power supply modules can operate independently, feeding four separate magnets, or two, three or four modules can operate in parallel. Each power supply module consists of a 12.5 kV vacuum circuit breaker, two three-winding, step-down transformers, a 24-pulse rectifier with interphase reactors, and a passive and an active filter. Two different transformer tap settings allow rated dc supply output voltages of 400 and 500 V. The rated current of a supply module is 17 kA and each supply module has a one-hour overload ...

Science.gov (United States)

A stochastic wind simulation for VAWTs (VSTOC) has been developed which yields turbulent wind-velocity fluctuations for rotationally sampled points. This allows three-component wind-velocity fluctuations to be simulated at specified nodal points on the wi...

Energy Technology Data Exchange (ETDEWEB)

Wind Powering America program launched the New England Wind Forum (NEWF) in 2005 to provide a single comprehensive source of up-to-date, Web-based information on a broad array of wind energy issues pertaining to New England. The NEWF newsletter provides New England stakeholders with updates on wind energy development in the region. In addition to regional updates, Issue #5 offers an interview with Angus King, former governor of Maine and co-founder of Independence Wind.

Science.gov (United States)

The effects of upwind turbine wakes on the performance of a FloWind 17-m vertical-axis wind turbine (VAWT) were investigated through a series of field experiments conducted at the FloWind wind farm on Cameron Ridge, Tehachapi, California. From the field m...

International Nuclear Information System (INIS)

We investigate the evolution of Type Ib/c supernova (SN Ib/c) progenitors in close binary systems, using new evolutionary models that include the effects of rotation, with initial masses of 12-25 M_s_u_n for the primary components, and of single helium stars with initial masses of 2.8-20 M_s_u_n. We find that, despite the impact of tidal interaction on the rotation of primary stars, the amount of angular momentum retained in the core at the presupernova stage in different binary model sequences converges to a value similar to those found in previous single star models. This amount is large enough to produce millisecond pulsars, but too small to produce magnetars or long gamma-ray bursts. We employ the most up-to-date estimate for the Wolf-Rayet mass-loss rate, and its implications for SN Ib/c progenitors are discussed in detail. In terms of stellar structure, SN Ib/c progenitors in binary systems at solar metallicity are ...

International Nuclear Information System (INIS)

We identify a source coincident with SN 2009kr in Hubble Space Telescope pre-explosion images. The object appears to be a single point source with an intrinsic color V - I = 1.1 #+-# 0.25 and M_V = -7.6 #+-# 0.6. If this is a single star, it would be a yellow supergiant of log L/L _s_u_n #approx# 5.1 and a mass of 15"+"5 _-_4 M _s_u_n. The spatial resolution does not allow us yet to definitively determine if the progenitor object is a single star, a binary system, or a compact cluster. We show that the early light curve is similar to a Type IIL SN, but the prominent H#alpha# P-Cygni profiles and the signature of the end of a recombination phase are reminiscent of a Type IIP. The evolution of the expanding ejecta will play an important role in understanding the progenitor object.

CERN Document Server

Magnetic fields correlated on several kiloparsec scales are seen in spiral galaxies. Their origin could be due to the winding up of a primordial cosmological field or due to amplification of a small seed field by a turbulent galactic dynamo. Both options have difficulties: There is no known battery mechanism for producing the required primordial field. Equally the turbulent dynamo may self destruct before being able to produce the large scale field, due to excess generation of small scale power. The current status of these difficulties is discussed. The resolution could depend on the nature of the saturated field produced by the small scale dynamo. We argue that the small scale fields do not fill most of the volume of the fluid and instead concentrate into intermittent ropes, with their peak value of order equipartition fields, and radii much smaller than their lengths. In this case these fields neither drain significant energy from the ...

UK PubMed Central (United Kingdom)

During development, multipotent neural precursors give rise to oligodendrocyte progenitor cells (OPCs), which migrate and divide to produce additional OPCs. Near the end of embryogenesis and...Full Text Available

UK PubMed Central (United Kingdom)

We studied telomeric DNA in leukemic cells as well as in normal T cells, B cells, monocytes, polymorphonuclear leukocytes, and bone marrow hematopoietic progenitor cells. No marked differences were...Full Text Available

UK PubMed Central (United Kingdom)

Constitutive activation of the transcription factor Stat5 in hematopoietic stem/progenitor cells leads to various hematopoietic malignancies including myeloproliferative neoplasm (MPN). Our recent study...Full Text Available

UK PubMed Central (United Kingdom)

Human bone marrow mesenchymal stem cells (BM-MSC) are multipotent progenitor cells that have transient immunomodulatory properties on Natural Killer (NK) cells, Dendritic Cells (DC), and T cells. This...Full Text Available

UK PubMed Central (United Kingdom)

Hyperproliferation of the colonic epithelium, leading to expansion of colonic crypt progenitors, is a recognized risk factor for colorectal cancer. Overexpression of progastrin, a nonamidated and incompletely...Full Text Available

UK PubMed Central (United Kingdom)

During asymmetric mitosis, both in male Drosophila germline stem cells and in mouse embryo neural progenitors, the mother centrosome is retained by the self-renewed cell; hence suggesting...Full Text Available

UK PubMed Central (United Kingdom)

Stem cell therapies for neurodegenerative disorders require accurate delivery of the transplanted cells to the sites of damage. Numerous studies have established that fluid injections to the hippocampus...Full Text Available

UK PubMed Central (United Kingdom)

In multiple sclerosis (MS), oligodendrocyte and myelin destruction lead to demyelination with subsequent axonal loss. Experimental demyelination in rodents has highlighted the activation of the subventricular...Full Text Available

UK PubMed Central (United Kingdom)

PurposeHyperglycemia and hypertension contribute to the development of diabetic retinopathy, and this may involve alterations in the normal retinal cell cycle. In this work, we examined...Full Text Available

International Nuclear Information System (INIS)

... range magnetic fields magnetic susceptibility magnetization neutron diffraction

Energy Technology Data Exchange (ETDEWEB)

Horizontal vibrations of elevator cars mainly occur because a car swings as roller guides installed at corners of a car frame move on a winding guide rail at high speeds. Rider comfort in high speed elevators is worsened by these vibrations. Conventional active dampers suppressing horizontal vibrations using ac servo motors make cars heavier so driving power becomes larger, and they are not easily applied to existing elevators. An active damping control method suited to super-high-speed elevators is which can solve these problems. The method suppresses vibrations by generating only enough magnetic force needed to suppress them only when vibrations of the car franc are produced. The vibrations are detected using acceleration detectors and magnets installed on left and right sides of the car frame. A computer simulator was made to analyze phenomena of car vibrations and to verify effects of the proposed ...

Energy Technology Data Exchange (ETDEWEB)

The wind unit working wheel has 4 radial rectangular frames arranged in two vertical planes which are perpendicular to each other. In the planes limited by the frames, on loop hinges with limiting supports, there are flat blades. When the working wheel rotates under the influence of wind pressure, the blades automatically occupy a vertical or horizontal (wind vane) position depending on the direction of blade motion and the direction of wind velocity.

Energy Technology Data Exchange (ETDEWEB)

The visual impact of wind turbines is one of the main factors affecting public acceptance of wind parks. This paper evaluates the visual impact of a wind park in Chania, Crete, using the Spanish method of evaluation. The outcomes are combined with the psychometric testing of the residents by the use of questionnaires and with the values of the Spanish method about various scenarios concerning the size of the wind park (double, half, one wind turbine). The results of the study prove that the quantification of the potential visual impact could minimize this, apparently, main reason that affects public acceptance. (author)

Energy Technology Data Exchange (ETDEWEB)

Climate change and limited primary energy resources require indigenous renewable electricity generation options to change the current coal-dominated power source matrix in China. The wind power is such a solution for the above challenges, and it still has large space for improvement in China. In this paper several critical factors related to Chinese wind power were studied in details, including the wind resources, the wind turbine industry and the policies from the Chinese government. Based on the study, the perspective of wind power in China was discussed. With outstanding advantages, the offshore wind power has a bright future in China, so its main characteristics are discussed. Based on the discussions, suggestions were given to improve the development of Chinese wind power, and the government's further measures are also ...

UK PubMed Central (United Kingdom)

Behavioral responses to wind are thought to play a critical role in controlling the dispersal and population genetics of wild Drosophila species1,Full Text Available

International Nuclear Information System (INIS)

... parameters magnetic fields magnetic properties magnetization monocrystals

International Nuclear Information System (INIS)

Reliability has an impact on wind energy project costs and benefits. Both life test data and field failure data can be used for reliability analysis. In wind energy industry, wind farm operators have greater interest in recording wind turbine operating data. However, field failure data may be tainted or incomplete, and therefore it needs a more general mathematical model and algorithms to solve the model. The aim of this paper is to provide a solution to this problem. A three-parameter Weibull failure rate function is discussed for wind turbines and the parameters are estimated by maximum likelihood and least squares. Two populations of German and Danish wind turbines are analyzed. The traditional Weibull failure rate function is also employed for comparison. Analysis shows that the three-parameter Weibull function can obtain more accuracy on reliability growth ...

Energy Technology Data Exchange (ETDEWEB)

Wind power is an increasingly significant renewable energy resource, producing no environmentally damaging CO2 emissions. The efficient production of electricity by wind turbines relies on aerodynamics. Aerodynamics of Wind Turbines provides the fundamental solutions to efficient wind turbine design. Following a historical introduction, Part 1 of Aerodynamics of Wind Turbines is concerned with basic rotor aerodynamics, while Part 2 deals with structural aspects of the wind turbine and calculation of the loads on it. Topics covered include increasing mass flow through the turbine, performance at low and high wind speeds, assessment of the extreme conditions under which the turbine will perform and the theory for calculating the lifetime of the turbine. The classical Blade Element Momentum method is also covered, as are eigenmodes and the ...

Energy Technology Data Exchange (ETDEWEB)

The study concerns 1984-1991. The wind park consists of 18 three-bladed 300 kW horizontal axis wind turbines of 35 meters height, and a rotor diameter of 30 meters, seven meteorological towers, and three cluster and control buildings. Aspects studied included disturbance of breeding, resting or feeding, and migrating birds, behavior of birds approaching the wind turbines during the day and night, and bird victims due to collision with the wind turbines and the meteorological towers. The flight behavior of birds approaching the wind park system during daylight is also dealt with. For at least a fifth of the observations it was noted whether the birds passing within 100 meters distance of a turbine showed a reaction or not. The proportion of the reactions was related to the wind park in operation or not in operation, and to the distance between the ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

Results are presented of an empirical analysis of the global thermodynamical requirements of the winds in the outer atmospheres of a representative sample of red giant stars of low- and intermediate-mass range. Results indicate that the mass-loss rates in these stars are not strongly dependent on the actual physical processes driving the winds. It is suggested that nonlinear processes act to regulate wind energy fluxes. Possible mechanisms responsible for the chromospheric heating and the mass loss in the low- and intermediate-mass giant stars are discussed. 151 refs.

Science.gov (United States)

1. Contest rules The European Space Agency (ESA) is launching a public competition to find the most suitable names for its four Cluster II space weather satellites. The quartet, which are currently known as flight models 5, 6, 7 and 8, are scheduled for launch from Baikonur Space Centre in Kazakhstan in June and July 2000. Professor Roger Bonnet, ESA Director of Science Programme, announced the competition for the first time to the European Delegations on the occasion of the Science Programme Committee (SPC) meeting held in Paris on 21-22 February 2000. The competition is open to people of all the ESA member states (*). Each entry should include a set of FOUR names (places, people, or things from history, mythology, or fiction, but NOT living persons). Contestants should also describe in a few sentences why their chosen names would be appropriate for the four Cluster II satellites. The winners will be those which are considered most suitable and relevant for the Cluster II mission. ...

British Library Electronic Table of Contents (United Kingdom)

This paper presents a combined experimental and computational study into the aerodynamics and performance of a small scale vertical axis wind turbine (VAWT). Wind tunnel tests were carried out to ascertain overall performance of the turbine and two- and three-dimensional unsteady computational fluid dynamics (CFD) models were generated to help understand the aerodynamics of this performance. Wind tunnel performance results are presented for cases of different wind velocity, tip-speed ratio and solidity as well as rotor blade surface finish. It is shown experimentally that the surface roughness on the turbine rotor blades has a significant effect on performance. Below a critical wind speed (Reynolds number of 30,000) the performance of the turbine is degraded by a smooth rotor surface finis...

Energy Technology Data Exchange (ETDEWEB)

Wind speed has been measured in Patenga, Cox`s Bazar, Kuakata, Moheshkhali, and Noakhali by the computerized anemometers. The wind computers have been installed at 20 meters height. According to this study annual average wind speeds in the coastal regions of Bangladesh are greater than 6.5 m/s at the height of 20 meters. It has been observed that during day times (8 a.m. to 7 p.m.) wind speeds are about 30 to 40% higher than the average values. The value of the power exponent {alpha} has been determined in the above sites and it is 0.139. So, at 40 meters height the annual average wind speed is about 7.15 m/s. So, wind speeds in the coastal regions of Bangladesh are suitable for both water pumping and electricity generation. Details are given in this paper with graphical and analytical representations. (author)

International Nuclear Information System (INIS)

Maps of wind resources were used to develop a method of evaluating climatic changes and their potential impacts on wind energy resources. Global IPCC climate change scenarios were used to predict climatic conditions for the future, while past wind resource availability was simulated and validated using NCEP and NCAR reanalysis data as well as observed meteorological data from Environment Canada. The simulations were used to compare each 5-year period with a 50-year reference period. Regional scale climate change impacts were evaluated using a statistical dynamic down-scaling method. Advanced meteorological models were used to predict wind flow patterns across specific landscapes. The evolution of past wind resource availability was then simulated. Five-year wind resource simulations for a 50-year period were simulated at 25 km"2 wind speeds ...

British Library Electronic Table of Contents (United Kingdom)

Ex vivo expanded peripheral blood progenitor cells (PBPC) have been shown to provide rapid neutrophil engraftment, and in some patients, to eliminate neutropenia after transplantation to support high-dose chemotherapy. However, the effect of expansion culture on stem cell content and potential loss of stem cells caused by induction of differentiation remains a concern. We have transplanted 21 patients with breast cancer with expanded autologous PBPC, with 11 patients receiving expanded PBPC as their sole hematopoietic cell source. In these studies, the CD34+ cells were selected and cultured for 10 days in defined media containing 100 ng/mL each of recombinant human stem cell factor (rhSCF), recombinant human granulocyte colony stimulating factor (rhG-CSF), and recombinant human megakaryocy...

International Nuclear Information System (INIS)

Observed parameter scaling laws show that lower-luminosity ellipticals have higher central densities and smaller core radii; if they formed by mergers, they are very unlike their progenitors. In the extreme case of M32, the central surface brightness is mu0 less than about 12 V mag/sq arcsec and the core radius is r(c) less than about 0.001 kpc, while plausible progenitor disk galaxies have mu0 of about 22 V mag/sq arcsec and r(c) of about 0.5 kpc. M32 must have formed by a dissipative collapse, whether or not a merger was involved. The cooling diagram also shows that low-luminosity ellipticals formed with more dissipation than high-luminosity ellipticals. Thus the merger picture of galalxy formation requires essential aspects of the dissipative collapse picture. 38 refs.

UK PubMed Central (United Kingdom)

Diamagnetic samples placed in a strong magnetic field and a magnetic field gradient experience a magnetic force. Stable magnetic levitation occurs when the magnetic force exactly counter balances...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

in pulse applications such as magnetic forming. ... In magnetic-forming electric circuitry, the ..... Aspects of Electrohydraulic land Magnetic Forming. ...

British Library Electronic Table of Contents (United Kingdom)

The wind speed distribution and wind energy potential are investigated in three selected locations in Oyo state using wind speed data that span between 12 and 20 years measured at 10 m height. In addition, the performance of selected small to medium size wind turbines in these sites were examined. The annual energy output and capacity factor for these turbines were determined. It was found that the monthly mean wind speeds in Oyo state ranges from 2.85 m/s to 5.20 m/s. While the monthly mean power density varies between 27.08 W/m2 and 164.48 W/m2, while the annual mean power density is in the range of 67.28 W/m2 and 106.60 W/m2. Based on annual energy output, wind turbines with cut-in wind speed of about 2.5 m/s and moderate rated wind speeds will be best suited for all the sites.

J-STORE (Japan)

Full Text Available

UK PubMed Central (United Kingdom)

A chromosome-encoded β-lactamase gene, cloned and expressed in Escherichia coli from Kluyvera georgiana reference strain CUETM 4246-74 (DSM 9408), encoded the...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Indoor air exposures to gaseous contaminants originating in soil can cause large human health risks. To predict and control these exposures, the mechanisms that affect vapor transport in near-surface soils need to be understood. In particular, radon exposure is a concern since average indoor radon concentrations lead to much higher risks than are generally accepted for exposure to other environmental contaminants. This dissertation examines an important component of the indoor radon problem: the impacts of wind on soil-gas and radon transport and entry into buildings. The research includes experimental and modeling studies of wind`s interactions with a building`s superstructure and the resulting soil-gas and radon flows in the surrounding soil. In addition to exploring the effects of steady winds, a novel modeling technique is developed to examine the impacts of fluctuating winds on soil-gas and radon ...

Energy Technology Data Exchange (ETDEWEB)

A stochastic wind simulation for VAWTs (VSTOC) has been developed which yields turbulent wind-velocity fluctuations for rotationally sampled points. This allows three-component wind-velocity fluctuations to be simulated at specified nodal points on the wind-turbine rotor. A first-order convection scheme is used which accounts for the decrease in streamwise velocity as the flow passes through the wind-turbine rotor. The VSTOC simulation is independent of the particular analytical technique used to predict the aerodynamic and performance characteristics of the turbine. The VSTOC subroutine may be used simply as a subroutine in a particular VAWT prediction code or it may be used as a subroutine in an independent processor. The independent processor is used to interact with a version of the VAWT prediction code which is segmented into deterministic and stochastic modules. Using VSTOC in ...

British Library Electronic Table of Contents (United Kingdom)

The wind turbines with a flanged-diffuser shroud-so called ?wind lens turbine??-are developed as one of high performance wind turbines by Ohya et al. In order to investigate the flow characteristics and flow acceleration, the paper presents the flow velocity measurements of a long-type and a compact-type wind turbines with a flanged-diffuser shroud by particle image velocimetry. In the case of the long type wind turbine, the velocity vectors of the inner flow field of the diffuser for turbine blades rotating and no blades rotating are presented at Reynolds number, 0.9?105. Furthermore the flow fields between with and without rotating are compared. Through the PIV measurement results, one can realize that the turbine blades rotating affects as suppress the disturbance and the flow separatio...

UK PubMed Central (United Kingdom)

Flying insects use visual cues to stabilize their heading in a wind stream. Many animals additionally track odors carried in the wind. As such, visual stabilization of upwind tracking directly aids...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The developed electrical networks in the agricultural regions of the Estonian SSR make it possible to construct relatively powerful wind power plants at the sites of the most favorable wind conditions with small outlays for the power transmission lines. The wind power plant electricity can be used to electrify the production processes in agriculture, while the surplus can be supplied to the energy system. The inclusion of the wind power plants in the energy system makes it possible to improve the total generation of energy or reduce the consumption of fuel. With the efficient arrangement of the wind power plants, one can also reduce the energy losses during its transfer. Calculations indicated that in the coastal zones of the Estonian SSR, one can obtain specific power of 420-480 kW/km/sup 2/. For comparison it is indicated that the Estonian SSR in the agricultural regions now uses ...

CERN Document Server

The present work concerns the numeric modeling of the sea-wave instability under the effect of the logarithmic wind at hurricane conditions (ignoring non-linear effects, such as wave breaking, foam production, etc. Powell et al. (2003)^1, Shtemler et al. (2003)^2. The central point of the study is the calculation of the growth rate, which is proportional to the fractional input energy from the wind to the wave exponentially varied with time. The present modeling demonstrates that the Miles-type model applying Charnock's formula Charnock (1955)^3 for roughness to the hurricane -wind parameters underestimates the growth rate of the wind waves 5-40 times as compared with the model employing the roughness and friction velocity adopted from experimental data for hurricane winds.^1 This occurs due to Charnock's formula fails at large wind speeds. The stability ...

Science.gov (United States)

A substantial design and development program has been underway in the United States of America on the Darrieus vertical axis wind turbine (VAWT). The purpose of this report is to present currently available information on: design, construction, and testin...

CERN Document Server

Major stellar-wind emission features in the spectrum of Eta Car have recently decreased by factors of order 2 relative to the continuum. This is unprecedented in the modern observational record. The simplest, but unproven, explanation is a rapid decrease in the wind density.

Science.gov (United States)

Radial Halbach magnetic bearings have been investigated as part of an effort to develop increasingly

Science.gov (United States)

Necessary theoretical foundation is given for the treatment of magnetic stresses applied to

KoreaScience (Korea)

Full Text Available

Science.gov (United States)

Discussion of an electrohydraulic and magnetic forming process

Energy Technology Data Exchange (ETDEWEB)

The Wind2H2 system is fully functional and continues to gather performance data. In this report, specifications of the Wind2H2 equipment (electrolyzers, compressor, hydrogen storage tanks, and the hydrogen fueled generator) are summarized. System operational experience and lessons learned are discussed. Valuable operational experience is shared through running, testing, daily operations, and troubleshooting the Wind2H2 system and equipment errors are being logged to help evaluate the reliability of the system.

KoreaScience (Korea)

Full Text Available

Science.gov (United States)

... 2-93 An Atmospheric Particle Emits Electromagnetic ... atmospheric water vapor produces a hydrometeor. ... subject to wind movement (either blowing ...

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The authors propose using synthetic aperture radar(SAR) for wind energy mapping of coastal zones. The SAR equipment is located on the European Space Agency ERS-1 and 2 and the RADARSAT satellites. Examples of wind energy maps and evaluations of their applications are given for the Norwegian west coast.

Energy Technology Data Exchange (ETDEWEB)

The horizontal spread of a plume in atmospheric dispersion can be described by the standard deviation of horizontal direction. The widely used Pasquill-Gifford classes of atmospheric stability have assigned typical values of the standard deviation of horizontal wind direction and of the lapse rate. A measured lapse rate can thus be used to estimate the standard deviation of wind direction. It is examined by means of a large dataset of fast wind measurements how good these estimates are. (author) 1 fig., 2 refs.

Science.gov (United States)

The Centre d'Etudes Nucleaires de Grenoble (France) has constructed nine Vertical Axis Wind Turbines (VAWT), of Darrieus type, 5 m diameter (D5), in order to acquire a wide knowledge of this kind of wind turbines and of its performances, the final goal be...

Energy Technology Data Exchange (ETDEWEB)

This paper proposes a novel control strategy for tracking peak power in a wind or wave energy system using a squirrel cage induction generator. It eliminates wind speed measurement or estimation and uses a simple scalar technique by exploiting the cubic nature of the power curve. The method works even when air velocity is varying dynamically. (author)

Energy Technology Data Exchange (ETDEWEB)

Presently, high wind potentials in remote areas may not be utilized for electricity production due to limited grid transmission capacity and/or difficulties in matching the electricity production with the demand. The overall project objective is to help overcome these bottlenecks, i.e. to identify and analyze methods and technologies for making it viable to utilize more of the wind potential in remote areas. The suggestion is to develop a power control concept for wind turbines which will even out the power fluctuations and make it possible to increase the wind energy penetration. The main options are to combine wind power with a pumped hydro power storage or with an AC/DC converter and battery storage. The AC/DC converter can either be an `add-on` type or it can be designed as an integrated part of a variable speed wind turbine. The idea is that combining ...

Science.gov (United States)

Theoretical and experimental research efforts in evaluating an innovative concept for vertical axis wind turbines (VAWT) are described. The concept is that of using straight blades composed of circulation controlled airfoil sections. The theoretical analysis has been developed to determine the unsteady lift and moment characteristics of multiple-blade cross-flow wind turbines. To determine the drag data needed as input to the theoretical analysis, an outdoor test model VAWT has been constructed; design details, instrumentation, and calibration results are reported. Initial testing is with fixed pitch blades having cross-sections of conventional symmetrical airfoils. Costs of building the test model are included, as well as estimates for blades constructed with composite materials. These costs are compared with those of other types of wind turbines.

Energy Technology Data Exchange (ETDEWEB)

Although the public generally hold positive attitudes towards wind energy, proposals for the construction of new wind farms are often met with strong resistance. In New Zealand, where the government has recently introduced ambitious policy targets for renewable energy generation, negative perceptions of wind farms are increasingly evident and have the potential to prevent the achievement of these targets. This research sets out to examine what influences social resistance to wind farms in New Zealand. Drawing from public submissions on three wind farm proposals, a framework developed by Devine-Wright [Devine-Wright, P., 2005a. Beyond NIMBYism: towards an integrated Framework for Understanding Public Perceptions of Wind Energy. Wind Energy 8, 125-139.] was used as the basis for identification of factors affecting public perceptions of ...

Energy Technology Data Exchange (ETDEWEB)

In many parts of the world and certainly in Europe large areas exist where the wind resources are good or very good and the grid is relatively weak due to a small population. In the areas the capacity of the grid can very often be a limiting factor for the exploitation of the wind resource. There are two main problems concerned with wind power and weak grids. The first is the steady state voltage level. The other main problem is voltage fluctuations. Some or all the these problems can be avoided if a so-called power control concept is applied together with the wind farm. The idea behind the power control concept is eliminate the violations of the steady state voltage level by buffering the power from the wind turbines in periods where the voltage limits might be violated and combine this ability with smoothing of the power output. The investigations have shown that the power control ...

Energy Technology Data Exchange (ETDEWEB)

A wind turbine is disclosed which permits high energy production over a wide range of wind forces while being protected against climatic hazards. According to the invention, a mast supports an energy recuperator comprising vane-type rotors by means of a frame which is orientable around a vertical axis. An energy conversion device is connected to the recuperator in order to be driven in rotation by the recuperator. The frame is responsive to the aerodynamic force exerted on the recuperator with respect to the mast and to the ground so as to optimize the power collected by the machine. The frame comprises a turret pivoted to the mast about the vertical axis and a structure pivoted to the turret about a horizontal axis of tilting motion. A balance weight maintains the recuperator in the top position when there is no wind. The aerodynamic drag of the recuperator acts in the opposite direction. In consequence, in the event of a ...

International Nuclear Information System (INIS)

Full text.This paper is to investigate the potentials and possibilities of electrical generation via wind turbine. Special attention is directed to the interpretation of wind generation characteristics and parameters found in Lebanon and linking the electrical energy to the Lebanese slectric grid. Although much of the wind energy research is very well established and boomed globally (USA, Europe, India and China), in Lebanon is never used. At a time when climate scientists are increasingly concerned about carbon dioxide emissions from coal and diesel plants, and the nuclear industry is drying, the significance of a major new source os electricity is clear. there are many motives and feasibility criteria for qind power generation in Lebanon. They include the need for increasing the Lebanese electrical capacity, reducing air pollution, alternative energy sources and prices and availability of oil. The work will include ...

CERN Document Server

We present a theoretical framework for formal study of systematic effects in Supernovae Type Ia (SN Ia) that utilizes 2-d simulations to implement a form of the deflagration-detonation transition (DDT) explosion scenario. The framework is developed from a randomized initial condition that leads to a sample of simulated SN Ia whose Ni56 masses have a similar average and range to those observed, and have many other modestly realistic features such as the velocity extent of intermediate mass elements. The intended purpose is to enable statistically well-defined studies of both physical and theoretical parameters of the SN Ia explosion simulation. We present here a thorough description of the outcome of the SN Ia explosions produced by our current simulations. A first application of this framework is utilized to study the dependence of the SN Ia on the Ne22 content, which is known to be directly influenced by the progenitor stellar population's metallicity. Our study ...

Energy Technology Data Exchange (ETDEWEB)

This paper addresses the stability aspects of several successful dc superconducting magnets such as large bubble chamber magnets, and magnets for the Mirror Fusion Test Facility and MHD Research Facility. Specifically, it will cover Argonne National Laboratory 12-Foot Bubble Chamber magnets, the 15-foot Bubble Chamber magnets at Fermi National Laboratory, the MFTF-B Magnet System at Lawrence Livermore National Laboratory, the U-25B Bypass MHD Magnet, and the CFFF Superconducting MHD magnet built by Argonne National Laboratory. All of these magnets are cooled in pool-boiling mode. Magnet design is briefly reviewed. Discussed in detail are the adopted stability critera, analyses of stability and disturbance, stability simulation, and the final results of magnet ...

International Nuclear Information System (INIS)

We investigate the magnetic braking of the core of an axisymmetric cloud whose rotation axis is parallel to the mean direction of the magnetic field. (author).

International Nuclear Information System (INIS)

The basic approach to radioactive labeling techniques in hemoglobin identification consists of mixing 14C labeled normal carrier globin with 3H labeled unknown globin and carrying out the subsequent separations and purifications looking at the distribution of 3H and 14C radioactivity. This technique was devised to ascertain the amino acid substitution in Hb Indianapolis and was instrumental in solving the structure of Hb Vicksburg. It was also useful in determining the purity of gamma-chains from cultures of human and baboon erythroid progenitors. Another use of this technique would be in identifying aberrant peaks of radioactivity in chain separation chromatograms, such as ''pre-peaks''.

Energy Technology Data Exchange (ETDEWEB)

Rare Earth Cobalt (REC) permanent magnets have unique properties that permit solutions to some optical tasks that cannot be accomplished with conventional magnets. A review of design and of performance characteristics of these magnets includes an analytical description of the three dimensional fringe fields of REC quadrupoles.

KoreaScience (Korea)

Full Text Available

KoreaScience (Korea)

Full Text Available

J-STORE (Japan)

Full Text Available

KoreaScience (Korea)

Full Text Available

KoreaScience (Korea)

Full Text Available

Science.gov (United States)

Magnetic Forming Studies. The use of transient high magnetic-field devices has made possible the generation of very large accurately ...

International Nuclear Information System (INIS)

... susceptibility magnetization magnetoresistance monocrystals order-disorder

Science.gov (United States)

... magnetic containment field lines which is zero on the center line of the toroidal containment tube and increases in magnitude with ...

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The CleverFarm project started out to build an integrated monitoring system for wind farms, where all information would be available and could be used across the wind farm for maintenance and component health assessments. This would enable wind farm operators to prioritise their efforts, since they have a good view of the farm status from home. A large emphasis was placed on the integration of condition monitoring approaches in the central system, enabling estimates of the remaining lifetime of components, especially in the nacelle. During the 3,5 years of the project, software and hardware was developed and installed in two wind farms in Denmark and Germany. The connected hardware included two different condition monitoring systems based on vibration sensors from Gram&Juhl and ISET, plus a camera system developed by Overspeed. Additionally, short-term predictions of the ...

British Library Electronic Table of Contents (United Kingdom)

An aerodynamic pendulum placed in a steady horizontal air flow is studied in connection with modeling a wind-receiving element of a vertical-axis wind turbine (VAWT). When modeling the medium effects on the pendulum, the following two approaches are combined: the quasi-static one based on stationary wind tunnel experiments and the unsteady one based on the added mass effects. The existence of stable and unstable rotational modes is analyzed analytically (via the Poincar?-Pontryagin method) and numerically. The dependence on the parameters responsible for the viscous friction at the rotation axis and for the added mass effects is taken into account.

Energy Technology Data Exchange (ETDEWEB)

This work deals with the development of wind maps in the Venezuelan coastal zones (South America). The Navier-Stokes equations for real viscous incompressible flow are discretized via the finite element method and they are applied to a full 3D numerical model. Two regions were analyzed: the Margarita island and the Paraguana peninsula, both of them located in the Caribbean Sea at the North of Venezuela. These regions were modeled by using a three dimensional control volume, discretized through hexaedric eight-noded finite elements. Some wind maps obtained in this research are presented and discussed. (author)

Science.gov (United States)

The Wind Energy Division at Sandia National Laboratories recently completed a point design based on the 34-m Vertical Axis Wind Turbine (VAWT) Test Bed. The 34-m Test Bed research machine incorporates several innovations that improve Darrieus technology, including increased energy production, over previous machines. The point design differs minimally from the Test Bed; but by removing research-related items, its estimated cost is substantially reduced. The point design is a first step towards a Test-Bed-based commercial machine that would be competitive with conventional sources of power in the mid-1990s.

Energy Technology Data Exchange (ETDEWEB)

This report describes the LIFECC computer program developed for the purpose of calculating the cost of energy produced by wind systems according to the principles of life cycle costing (LCC). Following a brief explanation of the LCC concept and its advantages, input variables to the program and their importance to various program users, including manufacturers and designers, utilities, various institutions and consumers, are explained. A detailed user's guide to the program is then provided, together with a sensitivity analysis which discusses the impact of key variables on wind system cost of energy and the importance of cash flow to the wind system purchaser. Sample cases of program output and an LIFECC program listing are provided.

Science.gov (United States)

... tests, one often encounters, for instance, separated flows with large ... It is suspected that the flow-quality criteria given in AGARD Report No. ...

Science.gov (United States)

... Descriptors : *JET ENGINE FUELS, *AQUATIC ORGANISMS, *AVIATION FUELS, *TOXICITY, HEALTH, SMOKE SCREENS, WIND, WATER ...

Energy Technology Data Exchange (ETDEWEB)

Electricity generation from wind turbines is now cost competitive for grid and off-grid applications in many developing regions, and close to competitive in others. Wind resources could generate thousands of megawatts of badly-needed power in Asia, North Africa, and Latin America. Barriers to penetrating power generation markets remain, however, including unequal access to investment capital, energy price and other market distortions, and often weak institutions for commercializing new technologies. Recognizing the potential economic and environmental benefits of wind power, bilateral and multilateral assistance organizations have for several years offered financial and technical assistance to promote its diffusion. Based on this experience and assistance for other renewable electric technologies, lessons and recommendations can be drawn regarding how assistance could more effectively overcome persistent market and policy ...

British Library Electronic Table of Contents (United Kingdom)

Abstract In this paper, a new predictive model that can forecast the performance of a vertical axis wind turbine (VAWT) is presented. The new model includes four primary variables (rotor velocity, wind velocity, air density, and turbine power output) as well as five geometrical variables (rotor radius, turbine height, turbine width, stator spacing, and stator angle). These variables are reduced to include the power coefficient (Cp) and tip speed ratio (TSR). A power coefficient correlation for a novel VAWT (called a Zephyr Vertical axis Wind Turbine (ZVWT)) is developed. The turbine is an adaptation of the Savonius design. The new correlation can predict the turbine's performance for altered stator geometry and varying operating conditions. Numerical simulations with a rotating reference f...

Energy Technology Data Exchange (ETDEWEB)

This paper describes a wide range of technical research and development that can reduce costs and improve technology for deep water deployment.

Science.gov (United States)

Evolution in Space Radio Telescopes Reveal Youngest Stellar Corpse Gas Clouds in Whirlpool Galaxy Yield Important Clues Supporting Theory on Spiral Arms Starbust-driven Winds...

Science.gov (United States)

These include, but are not limited to: stellar winds and outflows, post-main- sequence star evolution, binary star evolution, globular cluster structure and ...

International Nuclear Information System (INIS)

(Mar 1972). United States Harris, RD Taur, R. Logan, UT. 13 Sep 1971.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

This presentation details how wind turbine gearboxes fail to meet 20-year design life and how the Gearbox Reliability Collaborative (GRC) is addressing the challenges.

Science.gov (United States)

These include, but are not limited to: stellar winds and outflows, post-main- sequence stellar evolution, binary/multiple star evolution, globular cluster structure ...

Energy Technology Data Exchange (ETDEWEB)

As the penetration of wind energy continues to increase around the world, with a trend towards large utility-scale wind farms (greater than 100 MW), effective wind energy forecasting will become increasingly important. Previous work by GH has estimated the trading benefit of high quality short-term forecasting to be EUR 7/MWh. Depending on market conditions, for a 100 MW wind farm with a capacity factor of 30%, this equates to an estimated annual trading benefit of up to EUR 1.8m. To date, a number of studies have focused on the mathematical modelling techniques for forecasting the production from wind farms, looking predominantly at the task of predicting the meteorological conditions at the site. This paper focuses on the final stage of the forecasting process, conversion from a meteorological forecast to a power production forecast. This challenge is particularly significant for ...

Science.gov (United States)

The dynamic response characteristics of the VAWT rotor are important factors governing the safety and fatique life of VAWT systems. The principal problems are ...

Science.gov (United States)

This Dissertation presents the author's investigation and development of a systematic method for evaluating the aerodynamic performance of Vertical Axis Wind Energy Capture Systems (WECS) apart from their electrical generation capability. The current standard method for specifying a wind energy machine is to discuss its rated power in kilowatts (or megawatts when capacity exceeds 100 kW). While this holistic method is effective for comparing machines it does not reveal the essential characteristics necessary for optimization of individual machine components. The method developed herein separates the performance characteristics of the WECS from the generation characteristics and isolates them for benchmarking and optimization. In order to develop an evaluation criterion, it was essential to evaluate and benchmark the current state of the art for wind energy capture. A thorough history of Vertical Axis ...

International Nuclear Information System (INIS)

A non-contact method, using magnetic drag force principle, was proposed to design the braking systems to improve the shortcomings of the conventional braking systems. The extensive literature detailing all aspects of the magnetic braking is briefly reviewed, however little of this refers specifically to upright magnetic braking system, which is useful for industries. One of the major issues to design upright magnetic system is to find out the magnetic flux. The changing magnetic flux induces eddy currents in the conductor. These currents dissipate energy in the conductor and generate drag force to slow down the motion. Therefore, a finite element model is developed to analyze the phenomena of magnetic flux density when air gap and materials of track are varied. The verification shows the predicted magnetic flux is within ...

International Nuclear Information System (INIS)

To investigate the magnetic fluctuations and for further transport study, the poloidal and radial magnetic field measurement is conducted on the Sino United Spherical Tokamak (SUNIST). Auto-power spectral density indicates that the magnetic fluctuation energy mainly concentrates in the frequency region lower than 10 kHz. The magnetic field oscillations, which are characterized by harmonic frequencies of 40 kHz, are observed in the scrape-off layer; by contrast, in the plasma core, the magnetic fluctuations are of Gaussian type. The time-frequency profiles show that the poloidal magnetic fluctuations are temporally intermittent. The autocorrelation calculation indicates that the fluctuations in decorrelation time vary between the core and the edge. (authors)

Science.gov (United States)

The model was based on a SEDCO 700 series semi-submersible offshore drilling rig used for operations in the North Sea. This report supplements earlier work on wind-heeling moments which are required to establish stability criteria on semi-submersibles. Wi...

Science.gov (United States)

Wind-tunnel measurements were taken of the time-average aerodynamic forces and moments on a notional model of a semi-submersible offshore drilling rig at two heights and at various attitudes to the wind. Attempts were made to analyze the separate effects ...

CERN Document Server

Based on a mathematical simulation which reproduces accurate split and velocity profiles for the 100 and 200 metre sprints, the magnitudes of altitude and mixed wind/altitude-assisted performances as compared to their sea-level equivalents are presented. It is shown that altitude-assisted times for the 200 metre are significantly higher than for the 100 metre, suggesting that the ``legality'' of such marks perhaps be reconsidered.

Science.gov (United States)

Experiments contributing to the understanding of the aerodynamics of airfoils operating in the vertical axis wind turbine (VAWT) environment are described. These experiments are ultimately intended to reduce VAWT cost of energy and increase system reliability. They include chordwise pressure surveys, circumferential blade acceleration surveys, effects of blade camber, pitch and offset, blade blowing, and use of sections designed specifically for VAWT application.

CERN Document Server

Recent nucleosynthesis calculations of Type II supernovae using advanced neutrino transport determine that the early neutrino winds are proton-rich. However, a fraction of the ejecta emitted at the same time is composed of neutron-rich pockets. In this paper we calculate the nucleosynthesis contribution from the neutron-rich pockets in the hot convective bubbles of a core-collapse supernova and show that they do not contribute significantly to the total nucleosynthesis.

Science.gov (United States)

Double streamtube codes model the curved blade (Darrieus-type) vertical-axis wind turbine (VAWT) as a double actuator-disk arrangement (one disk for the upwind half of the rotor and a second disk for the downwind half) and use conservation of momentum pri...

Energy Technology Data Exchange (ETDEWEB)

Occurrence and distribution of harbour porpoises (Phocoena phocoena) in and around the off-shore wind farm on Horns Reef, Denmark, was investigated. This report describes data collected in 2003 as part of an ongoing monitoring program, covering a period before construction of the wind farm (baseline), the construction period in 2002 and one year following construction of the wind farm. Data from acoustic dataloggers (T-PODs) and visual surveys conducted from ships confirmed the presence of harbour porpoises inside the wind farm area during all periods investigated. Comparison with baseline data from 1999-2001 and with control areas outside the wind farm did not show a statistical significant change in sighting rates inside the wind farm area in the first year following construction relative to baseline. T-POD data showed a pronounced effect of the construction ...

Energy Technology Data Exchange (ETDEWEB)

Potassium clusters arrayed in zeolite A are known to show ferromagnetic properties at low temperature. The origin of the spontaneous magnetization has been explained by a model of spin-canting in an antiferromagnetically ordered state. The direct information for the magnetic structure, however, has not been obtained so far. In the present work, we measure the neutron powder diffraction by using pulsed neutron source at KEK-KENS below and above the Curie temperature. No significant temperature-dependence was, however, obtained within the statistical errors, namely, magnetic scattering could not be detected separately. We also estimate the intensity of magnetic scattering by assuming some possible magnetic structures with considering the magnetic form factor of the cluster wave function. The intensity of magnetic scattering is estimated to be ...

Energy Technology Data Exchange (ETDEWEB)

The control problem associated to a class of horizontal-axis fixed-pitch variable-speed low-power wind energy conversion systems, working in the partial load region, consisting in the energy conversion maximization, is approached here under the assumption that the wind turbine model and its parameters are poorly known. Using a new approach derived from the optimum seeking methods category, generically called Maximum Power Point Tracking (MPPT), the proposed control solution aims at driving the average position of the operating point near to optimality. Instead of inducing sinusoidal search signals, the wind turbulence is here used as search disturbance. The high-speed shaft's average rotational speed is slowly adjusted using the Fast Fourier Transform processing of some available measures from the system as an estimate of the operating point's position/distance to optimality. Numerical simulations are used ...

Energy Technology Data Exchange (ETDEWEB)

The main objective of the present study is twofold: (i) to analyze thermal loads of the geothermally and passively heated solar greenhouses; and (ii) to investigate wind energy utilization in greenhouse heating which is modeled as a hybrid solar assisted geothermal heat pump and a small wind turbine system which is separately installed in the Solar Energy Institute of Ege University, Izmir, Turkey. The study shows 3.13% of the total yearly electricity energy consumption of the modeled system (3568 kWh) or 12.53% of the total yearly electricity energy consumptions of secondary water pumping, brine pumping, and fan coil (892 kWh) can be met by using small wind turbine system (SWTS) theoretically. According to this result, modeled passive solar pre heating technique and combined with geothermal heat pump system (GHPS) and SWTS can be economically preferable to the conventional space heating/cooling systems used in agricultural ...

Science.gov (United States)

The Wind Energy Research Division of Sandia National Laboratories has been funded by the Wind/Ocean Technology Division of the Department of Energy (DOE) to design and build a 34-meter diameter Vertical Axis Wind Turbine (VAWT). The turbine design incorporates the results of recent VAWT research in aerodynamics and structural dynamics. Initial system concept studies identified several blade options that met the required power rating of 500 kW. The final blade and rotor configurations were chosen based on finite element calculations that determined the turbine modes of response, their frequency of vibration, and stress levels. For parked survival turbine components were designed to with stand the loading of a 150 mph (67.0 m/s) wind coupled with maximum cable tensions. Specific areas of design discussed include the rotor, cables, bearings, brakes, and foundations. Construction of the turbine is in ...

Science.gov (United States)

We have developed a transportable container based direct detection Doppler lidar based on the double-edge molecular technique. The pulsed solid state system was built at the University of Geneva. It was used to make range resolved measurements of the atmospheric wind field as part of the VALID campaign at the Observatoire de Haute Provence in Provence, France in July 1999. Comparison of our lidar wind measurements, which were analyzed without knowledge of the results of rawinsonde measurements made under the supervision of ESA, show good agreement with these rawinsondes. These are the first Doppler lidar field measurements made with an eyesafe direct detection molecular-based system at 355 nm and serve as a demonstrator for future spaceborne direct detection wind systems such as the Atmospheric Dynamics mission. Winds are an important contributor to sea surface temperature measurements made with the ...

International Nuclear Information System (INIS)

We investigate how 'extra' or 'excess' central light in the surface brightness profiles of cusp or power-law elliptical galaxies relates to the profiles of ellipticals with cores. The envelopes of cusp ellipticals are established by violent relaxation in mergers acting on stars present in gas-rich progenitor disks, while their centers are structured by the relics of dissipational, compact starbursts. Ellipticals with cores are formed by the subsequent merging of the now gas-poor cusp ellipticals, with the fossil starburst components combining to preserve a dense, compact component in these galaxies as well (although mixing of stars smooths the transition from the outer to inner components in the profiles). By comparing extensive hydrodynamical simulations to observed profiles spanning a broad mass range, we show how to observationally isolate and characterize the relic starburst component in core ellipticals. Our method recovers the younger starburst population, ...

Energy Technology Data Exchange (ETDEWEB)

A number of interactions between magnetic fields and matter is reviewed. The resulting forces range in magnitude from the very large, obtained in high-energy fields, to the weak ones caused by the magnetostriction of ferromagnets. The fundamentals of these interactions are highlighted, and the examples discussed are forces on dipoles, particle alignment, magnetostrictive forces, magnetic forming, magnetic stirring, levitation melting, and magnetic pulsing of tool steels. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Through an unusual differentiation process, human trophoblast progenitors (cytotrophoblasts) give rise to tumor-like cells that invade the uterus. By an unknown mechanism, invasive cytotrophoblasts exhibit permanent cell cycle withdrawal. Here we report molecular cytogenetic data showing that {approx} 20 to 60 percent of these interphase cells had acquired aneusomies involving chromosomes X, Y, o r16. The incidence positively correlated with gestational age and differentiation to an invasive phenotype. Scoring 12 chromosomes in flow-sorted cytotrophoblasts showed that more than 95 percent of the cells were hyperdiploid. Thus, aneuploidy appears to be an important component of normal placentation, perhaps limiting the proliferative and invasive potential of cytotrophoblasts within the uterus.

Energy Technology Data Exchange (ETDEWEB)

Substantially genetically stable continuous human cell lines derived from normal human mammary epithelial cells (HMEC) and processes for making and using the same. In a preferred embodiment, the cell lines are derived by treating normal human mammary epithelial tissue with a chemical carcinogen such as benzo(a)pyrene. The novel cell lines serve as useful substrates for elucidating the potential effects of a number of toxins, carcinogens and mutagens as well as of the addition of exogenous genetic material. The autogenic parent cells from which the cell lines are derived serve as convenient control samples for testing. The cell lines are not neoplastically transformed, although they have acquired several properties which distinguish them from their normal progenitors. 2 tabs.

Scientific Electronic Library Online (English)

Abstract in english We present a detailed derivation of the effective dielectric constant to be used in the dispersion relation for electrostatic waves in the case of a plasma immersed in a inhomogeneous magnetic field, with inhomogeneity perpendicular to the direction of the magnetic field.

Energy Technology Data Exchange (ETDEWEB)

An analytic model of magnetic torques applied to an accreting neutron star is employed to evaluate the magnetic dipole moments of x-ray pulsars. A new type of close binary system containing a neutron star is suggested.

Science.gov (United States)

The past decade has seen the development of eddy current probes for inspection of the mildly ferro-magnetic alloy Monel 400. Due to the rapid advances in permanent magnet technology similar probes have been upgraded to magnetically saturate, and hence ins...

International Nuclear Information System (INIS)

Parameters of permanent magnets result from the combination of intrinsic properties such as saturation magnetization, magnetic exchange, and magnetocrystalline energy, as well as microstructural parameters such as phase structure, grain size, and orientation. Reduction of grain size into nanocrystalline regime (#approx# 50 nm) leads to the enhanced remanence which derives from ferromagnetic exchange coupling between highly refined grains. In this study the fundamental phenomena, quantities, and structure parameters, which define nanophase permanent magnets are presented and discussed. The theoretical considerations are confronted with experimental data for nanocrystalline Sm-Fe-N type permanent magnets. (author)

Energy Technology Data Exchange (ETDEWEB)

It is often advantageous to generate power with combinations of wind and ocean waves. In fact ocean waves, their generation, propagation, dissipation are directly related to wind velocity and its duration oven the sea. In this paper an attempt has been made to demonstrate statistically to present some advantages with combined wind and ocean wave power generation. Even though many conceptual techniques and methods are possible to harness combined power generation, it is important to test feasibility of combined output as well as individual outputs mathematically. One of the major advantages of combined wind and wave power generation is to improve probability of continuous power supply (it minimises the interruptions and compensates power fluctuations with one another). Some of the major wave characteristics like wave Height (H), Time period (T), Wave length (L) significantly influence wave power ...

UK PubMed Central (United Kingdom)

OBJECTIVE--The study was performed to examine the influence of the exposure to magnetic fields in the potrooms of an electrolysis plant on the occurrence of musculoskeletal symptoms among the employees....Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The Muon Ionization Cooling Experiment (MICE) focusing solenoid magnets focus the muon beam within the MICE cooling channel on a liquid or solid absorber that is within the warm bore of solenoid. The focusing magnet has a warm bore of 470 mm. his magnet consists of two coils 210-mm long that is separated by an aluminum mandrel that is 200 mm long. Each of the coils has its own leads. The coils may be operated in either the non-flip mode (solenoid mode with both coils at the same polarity) or the lip mode (quadrupole focusing mode where both coils are at opposite polarity). This report describes the focusing solenoid magnet design that will be built by the vendor. The progress on the construction of the first of the focusing magnets will also be discussed in this report. Ultimately three of these magnets will be built. These magnets will be ...

Science.gov (United States)

... 31. New electric forming methods offer potentials for light metals; magnetic forming and plasma forming. ... 3, 25 Magnetic Forming ..... ...

International Nuclear Information System (INIS)

Highly ordered arrays of Ni nanoholes and Fe20Ni80 antidots have been prepared, respectively, by replica/antireplica processing and sputtering techniques using nanoporous alumina membranes as templates. Geometrical characteristics as nanohole/antidot diameter, interpore distance and the overall hexagonal symmetry of arrays are controlled through the original templates. Experimental data on their hysteresis and magnetic domain structure have been taken by vibrating sample magnetometry and magnetic force microscopy, respectively. An analysis of the magnetization process, resulting magnetic anisotropy and magnetic domain structure is summarized considering the influence of those geometry aspects. In particular, the hexagonal symmetry and the density of nanohole/antidots determine the overall magnetic behavior, which is of interest in future high-density ...

Science.gov (United States)

... M(TH) in applied magnetic fields up to ± 7 T and for temperatures ranging from 2 to 300 K. The superparamagnetic (SPM) behavior of these metallic ...

International Science & Technology Center (ISTC)

Development of Portable Normobaric Hypoxia and Pulsed Magnetic Field Firmware System for Enhancement of Radio- and Non-specific Resistance in Workers of Environmentally Hazardous Industries

International Nuclear Information System (INIS)

... dipole moments magnetic fields monocrystals neutron diffraction order-disorder

Science.gov (United States)

With the increased costs of maintaining boilers and chillers entrepreneurs around the country have offered magnetic and similar devices to facilities as viable alternatives to their maintenance program. This report gives a brief history of some of the pre...

Science.gov (United States)

Magnetic coil pressure wave generation for magnetic forming

Energy Technology Data Exchange (ETDEWEB)

From optical point of view and due to the magnetic interaction of the cold neutrons with the unpaired electron shell, magnetic materials hae a neutron spin-dependent refractive index n[sup +] [spin up] and n[sup -] [spin down]. Magnetic media such as Fe, Co and Ni react like birefringent uniaxial crystals in ordinary optica. n[sup +] and n[sup -] are the equivalent of the ordinary and extraordinary refractive indices. The specular reflection of spin polarized neutrons which is due to the discontinuity of the magnetic induction at the surface of the ferromagnet is a sensitive probe of surface and interface magnetism. We shall first give the background of the art of polarized neutron optics. Secondly, some recent examples from surface and interface magnetism will be given to illustrate the power of this technique such as the magnetic coupling ...

Science.gov (United States)

magnet research at several national laboratories through its Advanced Accelerator Technology Program. The HEP Conductor Development Program, a collaboration among national...

International Nuclear Information System (INIS)

Besides differentiation and apoptosis, cell migration is a basic process in brain development in which neural cells migrate several centimeters within the developing brain before reaching their proper positions and forming the right connections. For identifying signaling events that control neural migration and are therefore potential targets of chemicals to disturb normal brain development, we developed a human neurosphere-based migration assay based on normal human neural progenitor (NHNP) cells, in which the distance is measured that cells wander over time. Applying this assay, we investigated the role of the extracellular signal-regulated kinases 1 and 2 (ERK1/2) in the regulation of NHNP cell migration. Exposure to model substances like ethanol or phorbol 12-myristate 13-acetate (PMA) revealed a correlation between ERK1/2 activation and cell migration. The participation of phospho-(P-) ERK1/2 was confirmed by exposure of the cells to the MEK inhibitor PD98059, ...

Energy Technology Data Exchange (ETDEWEB)

Fugitive dust emissions from stockpiles in the open storage yards of industrial zones and the subsequent atmospheric dust dispersion have brought about many ecological and economical problems. This paper introduces a new approach to reduce pollutant emissions by simply changing pile configuration and without affecting the operational activity on these parks. Flow around piles of different geometries and for various wind conditions was studied using previously validated Computational Fluid Dynamic (CFD) simulations. Different pile height scenarios were investigated corresponding to a constant material volume and a fixed angle of repose under various wind magnitudes. The results obtained were integrated in order to evaluate the rate of dust emissions for the various configurations considered. It was found that, for the range of wind conditions and pile dimensions tested, an optimal geometry exists which corresponds to the ...

International Nuclear Information System (INIS)

A stratigraphic and geochemical study of alpine soils, which formed in later Pleistocene (late glacial) and Neoglacial deposits in the Wind River Mountains of western Wyoming, indicates that these soils are affected by air-fall in flux of inorganic pollutants. Arsenic, bromine and antimony appear to have been deposited in surface soils by incorporation of aeolian materials which were presumably transported by winds from industrial sources, including coal-burning operations. As vanadium was not found in surface soils at concentrations above site-specific background levels, oil-fired energy generating stations were not found to be significant sources of surface soil pollution in the region. Acid-rain effects were not observed in the soils. (author) 32 refs.; 2 figs.; 3 tabs.

British Library Electronic Table of Contents (United Kingdom)

This paper uses multi-pass iteration particle swarm optimization (MIPSO) to solve short term hydroelectric generation scheduling of a power system with wind turbine generators. MIPSO is a new algorithm for solving nonlinear optimal scheduling problems. A new index called iteration best (IB) is incorporated into particle swarm optimization (PSO) to improve solution quality. The concept of multi-pass dynamic programming is applied to modify PSO further and improve computation efficiency.The feasible operational regions of the hydro units and pumped storage plants over the whole scheduling time range must be determined before applying MIPSO to the problem. Wind turbine power generation then shaves the power system load curves. Next, MIPSO calculates hydroelectric generation scheduling. It beg...

Energy Technology Data Exchange (ETDEWEB)

The Department of Energy (DOE) and its predecessors have conducted research and development (R&D) in geothermal energy since 1971. To develop the technology needed to harness the Nation's vast geothermal resources, DOE's Office of Geothermal and Wind Technologies oversees a network of national laboratories, industrial contractors, universities, and their subcontractors. The following mission and goal statements guide the overall activities of the Office of Geothermal and Wind Technologies. This Federal Geothermal Program Research Update reviews the specific objectives, status, and accomplishments of DOE's Geothermal Program for Federal Fiscal Year (FY) 1999. The information contained in this Research Update illustrates how the mission and goals of the Office of Geothermal and Wind Technologies are reflected in each R&D activity. The Geothermal Program, from its guiding principles ...

Science.gov (United States)

As a US Department of Energy (DOE) laboratory, Sandia Laboratories is developing Darrieus vertical axis wind turbine (VAWT) technology with the objective of encouraging private industry to produce economically feasible, commercially marketable wind energy systems. The first full cycle of development is essentially complete, and resulting current technology designs have been evaluated for cost-effectiveness. Aerodynamic, structural, and system analyses capabilities have evolved during this cycle to support and evaluate the system designs. This report presents some of the more salient recent developments, first generation costs, current activities, and future plans. Potential design improvements identified in the first development cycle are presented along with their cost benefits.

British Library Electronic Table of Contents (United Kingdom)

VHF wind-profiling radars often measure a decrease of echo power with zenith angle, which can be explained from in situ measurements of horizontal layering or anisotropy of metre-scale temperature structure in the atmosphere. There can also be an azimuthal variation of echo power, which is increased in an azimuth opposite to the vertical shear vector of horizontal wind. This paper checks if the azimuth variation can also be linked to in situ observations of temperature structure, using aircraft flights in the tropopause region near a VHF radar. At heights where VHF radar measures wind shear and aspect sensitivity, there can be an asymmetry in the probability distribution of horizontal gradient of potential temperature, for horizontal scale of e.g. hundreds of metres. The asymmetry is often...

Energy Technology Data Exchange (ETDEWEB)

A three dimensional sea-land breeze model and lagrangian particle dispersion model have been employed for the study on the mesoscale atmospheric dispersion of radioactive materials released from Wolsung NPPs. In this study, atmospheric dispersion simulations are carried out under two synoptic weather conditions: the geostrophic flow is a weak northerly wind (CASE 1) and a strong northerly wind (CASE 2) on a clear day in spring. The results show that atmospheric dispersion is affected by sea-land breeze and the recirculation of particles by the change of wind direction between sea breeze and land breeze plays an important role in atmospheric concentration distribution of radioactive materials.

Energy Technology Data Exchange (ETDEWEB)

A study on development of magnetic drive packless valves for commercial purpose showed the results as follows; 1. Study on the radial rays effecting to the permanent magnets -Measurement of the strength of Nd-magnets according to irradiation of radial rays. 2. Effects of temperature on the magnetic driving device -Temperature dependency of the Nd-casting magnets. -Effects of temperature on the heat releasing fins of high-temperature valve. 3. Optimization of torque -Arranging method of permanent magnets -Measuring method and results of torque. 4. Design, manufacture and test for the pressure-resisting structure of magnetic power transmitting device -Calculation and design for the flat circular plates under pressure of the magnetic power transmitting device -Design, manufacture and test for the pressure-resisting ...

Energy Technology Data Exchange (ETDEWEB)

Tests have recently been performed at Fermilab in order to measure the energy losses due to eddy currents and iron and superconductor magnetization. These measurements were performed on six 1.5m long model magnets and eight 15m long full scale collider dipole magnets. AC losses were measured as a function of ramp rate using sawtooth ramps from 500, to 5000 Amps for both types of magnets, while bipolar studies were additionally performed on some of the short magnets. The measured magnet voltage and current for a complete cycle are digitally integrated to yield the energy loss per cycle. Measurement reproducibility is typically 5%, with good agreement between long magnet measurements and extrapolations from short magnet measurement results. Magnetization loss measurements among similar ...

Energy Technology Data Exchange (ETDEWEB)

Meteorological and air-quality data, as well as surface tracer concentration values, were collected during 1990 to assess the impact of Navajo Generating Station (NGS) emissions on Grand Canyon National Park (GCNP) air quality. These data have been used in the present investigation to determine between direct and indirect transport routes taken by the NGS plume to produce measured high-tracer concentration events at GCNP. Results show that complex-terrain features affect local wind-flow patterns during winter in the Grand Canyon area. Local channelling, decoupled canyon winds, and slope and valley flows dominate in the region when synoptic systems are weak. Direct NGS plume transport to GCNP occurs with northeasterly plume-height winds, while indirect transport to the park is caused by wind direction shifts associated with passing synoptic systems. Calculated polluted airmass positions along the modeled ...

International Nuclear Information System (INIS)

This paper presents the directional dependence of surface scaling parameters namely roughness length and corresponding friction velocity, for neutral category of Tarapur coastal site. The average roughness length of lowest value of 0.07 m (SW) and the highest value of 0.32 m (E) and average friction velocity of lowest value 1.6 m/sec(SSE) and a highest value 2.8 m/sec (SW) for the year 2006 were observed. Wind profile studies for the coastal site Tarapur with the wind data measured from meteorological tower of 30m which is at 1500m downwind fetch distance from the coastal line in the east direction gave the wind profile index parameter 'p' as 0.4, 0.5 and 0.75 for Unstable, Neutral and Stable weather conditions respectively. Sector Average Turbulent kinetic energy estimated as 17.7m2/s2 and its dissipation rate is 3.1 m2/s3 for the 10m elevation from the surface. A surface drag coefficient CD for the 10m height is 0.0076 ...

Energy Technology Data Exchange (ETDEWEB)

Less wind power plants in the landscape, more power from renewables, less carbon dioxide and higher tax: The advantages of repowering for communities are considerable. Still, they are hesitant to use it. (orig.)

Science.gov (United States)

million for advanced energy projects Thu, Sep 29, 2011 - Project Aims to Bring Bio-based Jet Fuel Production to the Northwest Mon, Sep 12, 2011 - Drive like the wind Thu, Aug 25,...

Energy Technology Data Exchange (ETDEWEB)

This review covers research done at Lawrence Livermore National Laboratory in the fields of astronomy and astrophysics. The research areas mentioned are as follows: star evolution, supernovae, and nucleosynthesis; stellar atmospheres and winds; galaxies and the interstellar medium; and high-energy astrophysics.

International Nuclear Information System (INIS)

A 2007 report compiled by members of the armed services indicates that climate change presents a serious security threat to the American public as well as to United States military operations. It is likely that climate change will increase global tensions and competition for resources. This presentation discussed advanced research and technology programs conducted by the National Aeronautics and Space Administration (NASA). Scientists and engineers at NASA have developed a number of technologies that may contribute to American energy security. Advanced energy research and development programs initiated by the organization include advanced heat engines; wind turbines; batteries and electric cars; solar photovoltaics; and fuel cell technologies. NASA's aeronautics and space exploration program has several capabilities relevant to advanced wind power systems. A collaborative program is currently underway to develop airborne ...

Science.gov (United States)

provides global ocean-surface wind fields with more structures than numerical weather prediction (Geophys. Res. Lett., Vol 25, No. 6, 761-764). The NSCAT data sets was produced...

Energy Technology Data Exchange (ETDEWEB)

Double streamtube codes model the curved blade (Darrieus-type) vertical-axis wind turbine (VAWT) as a double actuator-disk arrangement (one disk for the upwind half of the rotor and a second disk for the downwind half) and use conservation of momentum principles to determine the forces acting on the turbine blades and the turbine performance. These models differentiate between the upwind and downwind sections of the rotor and are capable of determining blade loading more accurately than the widely-used single-actuator-disk streamtube models. Additional accuracy may be obtained by representing the turbine as a collection of several streamtubes, each of which is modeled as a double actuator disk. This is referred to as the double-multiple-streamtube model. Sandia National Laboratories has developed a double-multiple streamtube model for the VAWT which incorporates the effects of the incident wind boundary layer, nonuniform velocity between the ...

Energy Technology Data Exchange (ETDEWEB)

A 19.1 metre wind turbine blade was subjected to static tests. The purpose of the test series was to verify the abilities of different types of sensors to detect damage in wind turbine blades. Prior to each of the static test-series an artificial damage was made on the blade. The damage made for each test-series was surveyed during each series by acoustic emission, fiber optic micro bend displacement transducers and strain gauges. The propagation of the damage was determined by use of ultra sonic and X-ray surveillance during stops in the test series. By use of acoustic emission it was possible to measure damage propagation before the propagation was of visible size. By use of fiber optic micro bend displacement transducers and strain gauges it was possible to measure minor damage propagation. By use of both ultra sonic, and X-ray NDT-equipment it were possible to determine the size of propagated damage. (au)

UK PubMed Central (United Kingdom)

Patients do considerable information work. Technologies that help patients manage health information so they can play active roles in their health-care, such as personal health records, provide...Full Text Available

Science.gov (United States)

The 17-metre DOE/Sandia VAWT began operation in March 1977. Since that time the turbine has been operated strictly by manual control for the purpose of data acquisition and performance analysis; this procedure has limited the VAWT operation time and power...

Science.gov (United States)

PMID:10860471

International Nuclear Information System (INIS)

Three different magnetic regimes; aerial, surface and buried; each with three different forces, have been used to investigate their effects on the water contents and photosynthetic pigments of sweet basil plants (Ocimum basilicum L.). Two groups of sweet basil seeds, Ocimum basilicum L. have been cultivated, one under normal conditions and the second has been subdivided into three portion (aerial, surface and buried) to examine the effect of different magnetic forces coming from the three directions on the resulted plants. At all directions of magnets, water contents have been significantly affected by the magnetic forces. Chlorophyll A and carotene contents have been affected, as well, according to the three magnetic forces coming from soil surface regime only. Chlorophyll B did not significantly affected by differences magnetic forces in the three regimes, but ...

KoreaScience (Korea)

Full Text Available

KoreaScience (Korea)

Full Text Available

KoreaScience (Korea)

Full Text Available

UK PubMed Central (United Kingdom)

The effects of a moderate-intensity static magnetic field (SMF) on osteoporosis of the lumbar vertebrae were studied in ovariectomized rats. A small disc magnet (maximum magnetic flux density 180 mT)...Full Text Available

International Nuclear Information System (INIS)

Using the full potential linearized augmented plane wave (FLAPW) method, thickness dependent magnetic anisotropy of ultrathin FeCo alloy films in the range of 1 monolayer (ML) to 5 ML coverage on Pd(0 0 1) surface has been explored. We have found that the FeCo alloy films have close to half metallic state and well-known surface enhancement in thin film magnetism is observed in Fe atom, whereas the Co has rather stable magnetic moment. However, the largest magnetic moment in Fe and Co is found at 1 ML thickness. Interestingly, it has been observed that the interface magnetic moments of Fe and Co are almost the same as those of surface elements. The similar trend exists in orbital magnetic moment. This indicates that the strong hybridization between interface FeCo alloy and Pd gives rise to the large magnetic moment. Theoretically calculated ...