SPH Modelling of Sea-ice Pack Dynamics
NASA Astrophysics Data System (ADS)
Staroszczyk, Ryszard
2017-12-01
The paper is concerned with the problem of sea-ice pack motion and deformation under the action of wind and water currents. Differential equations describing the dynamics of ice, with its very distinct mateFfigrial responses in converging and diverging flows, express the mass and linear momentum balances on the horizontal plane (the free surface of the ocean). These equations are solved by the fully Lagrangian method of smoothed particle hydrodynamics (SPH). Assuming that the ice behaviour can be approximated by a non-linearly viscous rheology, the proposed SPH model has been used to simulate the evolution of a sea-ice pack driven by wind drag stresses. The results of numerical simulations illustrate the evolution of an ice pack, including variations in ice thickness and ice area fraction in space and time. The effects of different initial ice pack configurations and of different conditions assumed at the coast-ice interface are examined. In particular, the SPH model is applied to a pack flow driven by a vortex wind to demonstrate how well the Lagrangian formulation can capture large deformations and displacements of sea ice.
Two-stage energy storage equalization system for lithium-ion battery pack
NASA Astrophysics Data System (ADS)
Chen, W.; Yang, Z. X.; Dong, G. Q.; Li, Y. B.; He, Q. Y.
2017-11-01
How to raise the efficiency of energy storage and maximize storage capacity is a core problem in current energy storage management. For that, two-stage energy storage equalization system which contains two-stage equalization topology and control strategy based on a symmetric multi-winding transformer and DC-DC (direct current-direct current) converter is proposed with bidirectional active equalization theory, in order to realize the objectives of consistent lithium-ion battery packs voltages and cells voltages inside packs by using a method of the Range. Modeling analysis demonstrates that the voltage dispersion of lithium-ion battery packs and cells inside packs can be kept within 2 percent during charging and discharging. Equalization time was 0.5 ms, which shortened equalization time of 33.3 percent compared with DC-DC converter. Therefore, the proposed two-stage lithium-ion battery equalization system can achieve maximum storage capacity between lithium-ion battery packs and cells inside packs, meanwhile efficiency of energy storage is significantly improved.
Design of new central solenoid for SST-1
NASA Astrophysics Data System (ADS)
Prasad, Upendra; Pradhan, Subrata; Ghate, Mahesh; Raj, Piyush; Tanna, V. L.; Khan, Ziauddin; Roy, Swati; Santra, Prosenjit; Biswas, Prabal; Sharma, A. N.; Khristi, Yohan; Kanaber, Deven; Varmora, Pankaj
2017-04-01
The key role of central solenoid (CS) magnet of a Tokamak is for gas breakdown, ramp up and maintaining of plasma current. The magnetic flux change in CS along with other PF coils generates magnetic null and induces electric field in toroidal direction. The induced toroidal electric field accelerates the residual electrons which collide with the neutrals and an avalanche takes place which led to the net plasma in the vacuum vessel of a Tokamak. In order to maximize the CS volt-sec capability, the higher magnetic field with a greater magnetic flux linkage is necessary. In order to facilitate all these requirements of SST-1 a new superconducting CS has been designed for SST-1. The design of new central solenoid has two bases; first one is physics and second is smart engineering in limited bore diameter of ∼ 655 mm. The physics basis of the design includes volt-sec storage capacity of ∼ 0.8 volt-sec, magnetic field null around 0.2 m over major radius of 1.1 m and toroidal electric field of ∼ 0.3 volt/m. The engineering design of new CS consists of Nb3Sn cable in conduit conductor (CICC) of operating current of 14 kA @ 4.5 K at 6 T, consolidated winding pack, smart quench detection system, protection system, housing cryostat and conductor terminations and joint design. The winding pack consists of 576 numbers of turns distributed in four layers with 0.75 mm FRP tape soaked with cyanide Easter based epoxy resin turn insulation and 3 mm of ground insulation. The interlayer low resistance (∼1 nΩ) terminal praying hand joints at 14 kA at 4.5 K has been designed for making winding pack continuous. The total height of winding pack is 2500 mm. The stored energy of this winding pack is ∼ 3 MJ at 14 kA of operating current. The expected heat load at cryogenic temperature is ∼ 10 W per layer, which requires helium mass flow rate of 1.4 g/s at 1.4 bars @ 4.5 K. The typical diameter and height of housing cryostat are 650 mm and 2563 mm with 80 K shield respectively. The protection system consists of SS310 made array of dump resistor of 20 mΩ. The detail physics and engineering design of new superconducting CS of SST-1 will be discussed in this presentation.
STS-48 ESC Earth observation of ice pack, Antarctic Ice Shelf
NASA Technical Reports Server (NTRS)
1991-01-01
STS-48 Earth observation taken aboard Discovery, Orbiter Vehicle (OV) 103, is of the breakup of pack ice along the periphery of the Antarctic Ice Shelf. Strong offshore winds, probably associated with katabatic downdrafts from the interior of the continent, are seen peeling off the edges of the ice shelf into long filaments of sea ice, icebergs, bergy bits, and growlers to flow northward into the South Atlantic Ocean. These photos are used to study ocean wind, tide and current patterns. Similar views photographed during previous missions, when analyzed with these recent views may yield information about regional ice drift and breakup of ice packs. The image was captured using an electronic still camera (ESC), was stored on a removable hard disk or small optical disk, and was converted to a format suitable for downlink transmission. The ESC documentation was part of Development Test Objective (DTO) 648, Electronic Still Photography.
Western Ross Sea and McMurdo Sound Ice Forecasting Guide.
1975-06-01
areal ice distribution and follow the sane historical proqression of pack disintergration . This technique assumes that environmental conditions...30-day) are based on historical ice data which cxnbine averaae disintergration rates as well as averace wind and current drift. Iong-range wind...original 2 to 3 okta area and its new cnfiguration remains the same, the products of ocnoentrations and widths at the verifying time must equal the
Particle packing from an earth science viewpoint
NASA Astrophysics Data System (ADS)
Rogers, C. D. F.; Dijkstra, T. A.; Smalley, I. J.
1994-04-01
Particle packings are relevant to many aspects of the Earth sciences, and there is a long history of the study of packings from an Earth science viewpoint. Packings have also been studied in connection with other subjects and disciplines. Allen (1982) produced a major review which provides a solid base for Earth science related studies. This review complements Allen's work and in particular focuses on advances in the study of random packings over the last ten years. Transitions from packing to packing may be as important as the packings themselves, and possibly easier to model. This paper places emphasis on certain neglected works, in particular Morrow and Graves (1969) and the packing transition envelope, Kahn (1956) and the measurement of packing parameters, Griffiths (1962) on packings in one-dimension, and Getis and Boots (1978) on packings in two dimensions. Certain packing problems are relevant to current areas of study including structure collapse in loess (hydroconsolidation), flowslides in very sensitive soils, wind erosion, jewel quality in opals and the structure and functions of sand dunes. The region where interparticle forces become active (particles < 200 μm) is considered and the implications for packing are examined.
High-performance superconductors for Fusion Nuclear Science Facility
Zhai, Yuhu; Kessel, Chuck; Barth, Christian; ...
2016-11-09
High-performance superconducting magnets play an important role in the design of the next step large-scale, high-field fusion reactors such as the fusion nuclear science facility (FNSF) and the spherical tokamak (ST) pilot plant beyond ITER. Here, Princeton Plasma Physics Laboratory is currently leading the design studies of the FNSF and the ST pilot plant study. ITER, which is under construction in the south of France, utilizes the state-of-the-art low temperature superconducting magnet technology based on the cable-in-conduit conductor design, where over a thousand multifilament Nb 3Sn superconducting strands are twisted together to form a high-current-carrying cable inserted into a steelmore » jacket for coil windings. We present design options of the high-performance superconductors in the winding pack for the FNSF toroidal field magnet system based on the toroidal field radial build from the system code. For the low temperature superconductor options, the advanced J cNb 3Sn RRP strands (J c > 1000 A/mm 2 at 16 T, 4 K) from Oxford Superconducting Technology are under consideration. For the high-temperature superconductor options, the rectangular-shaped high-current HTS cable made of stacked YBCO tapes will be considered to validate feasibility of TF coil winding pack design for the ST-FNSF magnets.« less
High-performance superconductors for Fusion Nuclear Science Facility
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhai, Yuhu; Kessel, Chuck; Barth, Christian
High-performance superconducting magnets play an important role in the design of the next step large-scale, high-field fusion reactors such as the fusion nuclear science facility (FNSF) and the spherical tokamak (ST) pilot plant beyond ITER. Here, Princeton Plasma Physics Laboratory is currently leading the design studies of the FNSF and the ST pilot plant study. ITER, which is under construction in the south of France, utilizes the state-of-the-art low temperature superconducting magnet technology based on the cable-in-conduit conductor design, where over a thousand multifilament Nb 3Sn superconducting strands are twisted together to form a high-current-carrying cable inserted into a steelmore » jacket for coil windings. We present design options of the high-performance superconductors in the winding pack for the FNSF toroidal field magnet system based on the toroidal field radial build from the system code. For the low temperature superconductor options, the advanced J cNb 3Sn RRP strands (J c > 1000 A/mm 2 at 16 T, 4 K) from Oxford Superconducting Technology are under consideration. For the high-temperature superconductor options, the rectangular-shaped high-current HTS cable made of stacked YBCO tapes will be considered to validate feasibility of TF coil winding pack design for the ST-FNSF magnets.« less
Wind tunnel experiments: influence of erosion and deposition on wind-packing of new snow
NASA Astrophysics Data System (ADS)
Sommer, Christian G.; Lehning, Michael; Fierz, Charles
2018-01-01
Wind sometimes creates a hard, wind-packed layer at the surface of a snowpack. The formation of such wind crusts was observed during wind tunnel experiments with combined SnowMicroPen and Microsoft Kinect sensors. The former provides the hardness of new and wind-packed snow and the latter spatial snow depth data in the test section. Previous experiments showed that saltation is necessary but not sufficient for wind-packing. The combination of hardness and snow depth data now allows to study the case with saltation in more detail. The Kinect data requires complex processing but with the appropriate corrections, snow depth changes can be measured with an accuracy of about 1 mm. The Kinect is therefore well suited to quantify erosion and deposition. We found that no hardening occurred during erosion and that a wind crust may or may not form when snow is deposited. Deposition is more efficient at hardening snow in wind-exposed than in wind-sheltered areas. The snow hardness increased more on the windward side of artificial obstacles placed in the wind tunnel. Similarly, the snow was harder in positions with a low Sx parameter. Sx describes how wind-sheltered (high Sx) or wind-exposed (low Sx) a position is and was calculated based on the Kinect data. The correlation between Sx and snow hardness was -0.63. We also found a negative correlation of -0.4 between the snow hardness and the deposition rate. Slowly deposited snow is harder than a rapidly growing accumulation. Sx and the deposition rate together explain about half of the observed variability of snow hardness.
Wind Tunnel Experiments: Influence of Erosion and Deposition on Wind-Packing of New Snow
NASA Astrophysics Data System (ADS)
Sommer, C.; Fierz, C. G.; Lehning, M.
2017-12-01
We observed the formation of wind crusts in wind tunnel experiments. A SnowMicroPen was used to measure the hardness profile of the snow and a Microsoft Kinect provided distributed snow depth data. Earlier experiments showed that no crust forms without saltation and that the dynamics of erosion and deposition may be a key factor to explain wind-packing. The Kinect data could be used to quantify spatial erosion and deposition patterns and the combination with the SnowMicroPen data allowed to study the effect of erosion and deposition on wind-hardening. We found that erosion had no hardening effect on fresh snow and that deposition is a necessary but not sufficient condition for wind crust formation. Deposited snow was only hardened in wind-exposed areas. The Kinect data was used to calculate the wind-exposure parameter Sx. We observed no significant hardening for Sx>0.25. The variability of resulting wind crust hardnesses at Sx<0.25 was still large, however.
Effects of lead structure in Bering Sea pack ice on the flight costs of wintering spectacled eiders
NASA Astrophysics Data System (ADS)
Bump, Joseph K.; Lovvorn, James R.
2004-10-01
In polar regions, sea ice is critical habitat for many marine birds and mammals. The quality of pack ice habitat depends on the duration and spacing of leads (openings in the ice), which determine access to water and air for diving endotherms, and how often and how far they must move as leads open and close. Recent warming trends have caused major changes in the extent and nature of sea ice at large scales used in climate models. However, no studies have analyzed lead structure in terms of habitat for ice-dependent endotherms, or effects of climate on ice habitat at scales relevant to their daily movements. Based on observations from an icebreaker and synthetic aperture radar (SAR) images, we developed methods to describe the dynamics and thermodynamics of lead structure relative to use by spectacled eiders ( Somateria fischeri) wintering in pack ice of the Bering Sea. By correlating lead structure with weather variables, we then used these methods to estimate changes in lead dynamics from 1945 to 2002, and effects of such changes on flight costs of the eiders. For 1991-1992, when images were available about every 3 days throughout winter, SAR images were divided among five weather regimes defined by wind speed, wind direction, and air temperature. Based on 12.5-m pixels, lead shape, compass orientation, and fetch across leads did not differ among the weather regimes. However, the five regimes differed in total area of open water, leads per unit area, and distance between leads. Lead duration was modeled based on air temperature, wind, and fetch. Estimates of mean daily flight time for eiders, based on lead duration and distance between neighboring leads, differed among regimes by 0 to 15 min. Resulting flight costs varied from 0 to 158 kJ day -1, or from 0% to 11% of estimated field metabolic rate. Over 57 winters (1945-2002), variation among years in mean daily flight time was most influenced by the north-south wind component, which determined pack divergence (lead opening) during northerly winds or pack convergence (lead closing) during southerly winds. Mean daily flight time and flight cost during winter did not differ among proposed periods of decadal-scale climate shifts in the North Pacific Ocean. Although leads in mobile pack ice constantly open and close with variations in wind, under most conditions in the Bering Sea there appeared to be a shifting-mosaic steady-state of lead availability. Long-term trends in the extent and timing of Bering Sea pack ice may have affected spectacled eiders more by altering foodweb processes than by changing flight costs relative to lead structure.
NASA Technical Reports Server (NTRS)
1985-01-01
Extensive computer based engineering design effort resulted in optimization of a superconducting magnet design with an average bulk current density of approximately 12KA/cm(2). Twisted, stranded 0.0045 inch diameter NbTi superconductor in a copper matrix was selected. Winding the coil from this bundle facilitated uniform winding of the small diameter wire. Test coils were wound using a first lot of the wire. The actual packing density was measured from these. Interwinding voltage break down tests on the test coils indicated the need for adjustment of the wire insulation on the lot of wire subsequently ordered for construction of the delivered superconducting magnet. Using the actual packing densities from the test coils, a final magnet design, with the required enhancement and field profile, was generated. All mechanical and thermal design parameters were then also fixed. The superconducting magnet was then fabricated and tested. The first test was made with the magnet immersed in liquid helium at 4.2K. The second test was conducted at 2K in vacuum. In the latter test, the magnet was conduction cooled from the mounting flange end.
Physical properties of a resin system for filling the inter-space in the ITER TF coil casing
NASA Astrophysics Data System (ADS)
Evans, D.; Baynahm, E.; Canfer, S.; Foussat, A.
2014-01-01
Each of the eighteen ITER Toroidal Field (TF) coils will consist of seven double pancakes. Each double pancake will have been individually vacuum impregnated and then the seven units assembled together, over-wrapped with glass fabric based insulation and finally vacuum impregnated again to form the TF coil winding pack [1]. The winding pack (WP) will be finally assembled into the coil casing (CC) and to allow for manufacturing tolerances and final geometric definition, a nominal 10 mm gap will exist between the winding pack and the coil case but in practice, this gap may vary between 3 and 15 mm. After assembly, the final step will be to fill the gap with a material that will maintain the final position of the WP and to uniformly transfer load from WP to CC. This paper deals with the selection of materials and techniques to fill the gap and details some of the properties of the chosen material.
Study on mitigation of pulsed heat load for ITER cryogenic system
NASA Astrophysics Data System (ADS)
Peng, N.; Xiong, L. Y.; Jiang, Y. C.; Tang, J. C.; Liu, L. Q.
2015-03-01
One of the key requirements for ITER cryogenic system is the mitigation of the pulsed heat load deposited in the magnet system due to magnetic field variation and pulsed DT neutron production. As one of the control strategies, bypass valves of Toroidal Field (TF) case helium loop would be adjusted to mitigate the pulsed heat load to the LHe plant. A quasi-3D time-dependent thermal-hydraulic analysis of the TF winding packs and TF case has been performed to study the behaviors of TF magnets during the reference plasma scenario with the pulses of 400 s burn and repetition time of 1800 s. The model is based on a 1D helium flow and quasi-3D solid heat conduction model. The whole TF magnet is simulated taking into account thermal conduction between winding pack and case which are cooled separately. The heat loads are given as input information, which include AC losses in the conductor, eddy current losses in the structure, thermal radiation, thermal conduction and nuclear heating. The simulation results indicate that the temperature variation of TF magnet stays within the allowable range when the smooth control strategy is active.
4. PACK TRAIN WAITING TO BE UNLOADED AT FOOT OF ...
4. PACK TRAIN WAITING TO BE UNLOADED AT FOOT OF YAKI TRAIL. APPROXIMATELY TWO-AND-ONE-HALF TONS OF STEEL ON ANIMALS SHOWN. NOTE COIL OF 1-1/2' WIND CABLE IN FOREGROUND. - Kaibab Trail Suspension Bridge, Spanning Colorado River, Grand Canyon, Coconino County, AZ
Diagnosis of Electric Submersible Centrifugal Pump
NASA Astrophysics Data System (ADS)
Kovalchuk, M. S.; Poddubniy, D. A.
2018-01-01
The paper deals with the development of system operational diagnostics of electrical submersible pumps (ESP). At the initial stage of studies have explored current methods of the diagnosis of ESP, examined the existing problems of their diagnosis. Resulting identified a number of main standard ESP faults, mechanical faults such as bearing wear, protective sleeves of the shaft and the hubs of guide vanes, misalignment and imbalance of the shafts, which causes the breakdown of the stator bottom or top bases. All this leads to electromagnetic faults: rotor eccentricity, weakening the pressing of steel packs, wire breakage or a short circuit in the stator winding, etc., leading to changes in the consumption current.
NASA Astrophysics Data System (ADS)
Chen, Peng
As the only high temperature superconductor with round wire (RW) geometry, Bi2Sr2CaCu2O8+x (Bi-2212) superconducting wire has the advantages of being multi-filamentary, macroscopically isotropic and twistable. With overpressure (OP) processing techniques recently developed by our group at the National High Magnetic Field Laboratory (NHMFL), the engineering current density (Je) of Bi-2212 RW can be dramatically increased. For example, Je of more than 600 A/mm 2 (4.2 K and 20 T) is achieved after 100 bar OP processing. With these intrinsically beneficial properties and recent processing progress, Bi-2212 RW has become very attractive for high field magnet applications, especially for nuclear magnetic resonance (NMR) magnets and accelerator magnets etc. This thesis summarizes my graduate study on Bi-2212 solenoids for high field and high homogeneity NMR magnet applications, which mainly includes performance study of Bi-2212 RW insulations, 1 bar and OP processing study of Bi-2212 solenoids, and development of superconducting joints between Bi-2212 RW conductors. Electrical insulation is one of the key components of Bi-2212 coils to provide sufficient electrical standoff within coil winding pack. A TiO 2/polymer insulation offered by nGimat LLC was systematically investigated by differential thermal analysis (DTA), thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), dielectric property measurements, and transport critical current (Ic) property measurements. About 29% of the insulation by weight is polymer. When the Bi-2212 wire is fully heat treated, this decomposes with slow heating to 400 °C in flowing O2. After the full reaction, we found that the TiO2 did not degrade the critical current properties, adhered well to the conductor, and provided a breakdown voltage of more than 100 V. A Bi-2212 RW wound solenoid coil was built using this insulation being offered by nGimat LLC. The coil resistance was constant through coil winding, polymer burn-off and full coil reaction. The coil was successfully tested at the NHMFL generating 33.8 T combined magnetic field in a 31.2 T background field. Multiple quenches occurred safely, which also illustrates that the insulation provided sufficient dielectric standoff. For Bi-2212 RW with a typical as-drawn diameter of 1.0-1.5 mm, this 15 microm thick insulation allows a very high coil packing factor of ~0.74, whereas earlier alumino-silicate braid insulation only allows packing factors of 0.38-0.48. In addition to the commercial TiO2/polymer insulation, we have also investigated sol-gel based ceramic coatings through collaboration with Harran University and another TiO2 based insulation coating at the NHMFL. Since Bi-2212 superconducting coils employ the Wind-and-React (W&R) technology, there are some potential issues in processing Bi-2212 coils, in particular for coils with a large thermal mass and dense oxide insulation coating. For this study, several Bi-2212 test solenoids with an outer diameter (OD) of about 90 mm were built and heat treated in 1 bar flowing oxygen with deadweights applied so as to simulate large coil packs. After the heat treatment (HT), coils were epoxy impregnated and cut. Winding pack was checked using SEM in terms of conductor geometry and insulation. Some samples were extracted to measure transport critical current Ic and critical temperature Tc. The results are very promising: test coils presented low creep behavior after standard partial melt HT under mechanical load, and no Ic degradation was found due to the application of mechanical load, and no inadequate oxygenation issue was seen for thick coils with ceramic coating on the wire. However, coils were partially electrically shorted after 1 bar HT under mechanical load, and we believe that increasing insulation coating thickness is necessary. In addition, several small solenoids were manufactured to study OP processing of Bi-2212 coils. The preliminary results indicate that there are some gaps between turns due to densification of wires (~4% wire diameter reduction) during 50-100 bar OP processing, and the diameter shrinking of conductors will potentially lead to coil sagging. So far, we have developed some methods to solve the issue of coil sagging, such as using flexible coil flange to allow smooth sagging of winding pack during OP processing. We have also investigated electrical joints between Bi-2212 RW conductors, which include resistive joints and superconducting joints. For resistive Bi-2212 joints, we evaluated conventional diffusion bonding method and soldering method. In general, the joints (with 42 mm joint length) resistances are below 200 nO at 4.2 K and magnetic fields up to 13.5 T, and the effect of magnetoresistance is clearly present. In addition to resistive joints, we successfully developed a superconducting joint between Bi-2212 RW conductors for persistent current mode (PCM) operations. (Abstract shortened by UMI.).
Thermal Measurements of Packed Copper Wire Enables Better Electric Motor
transmittance characterization methods both parallel and perpendicular to the axis. A measurement of apparent from all three test methods indicated that the k_app of the packed copper wire was significantly higher methods for examining the thermal impact of new materials for winding structures relevant to motor
NASA Astrophysics Data System (ADS)
Stössel, Achim; von Storch, Jin-Song; Notz, Dirk; Haak, Helmuth; Gerdes, Rüdiger
2018-03-01
This study is on high-frequency temporal variability (HFV) and meso-scale spatial variability (MSV) of winter sea-ice drift in the Southern Ocean simulated with a global high-resolution (0.1°) sea ice-ocean model. Hourly model output is used to distinguish MSV characteristics via patterns of mean kinetic energy (MKE) and turbulent kinetic energy (TKE) of ice drift, surface currents, and wind stress, and HFV characteristics via time series of raw variables and correlations. We find that (1) along the ice edge, the MSV of ice drift coincides with that of surface currents, in particular such due to ocean eddies; (2) along the coast, the MKE of ice drift is substantially larger than its TKE and coincides with the MKE of wind stress; (3) in the interior of the ice pack, the TKE of ice drift is larger than its MKE, mostly following the TKE pattern of wind stress; (4) the HFV of ice drift is dominated by weather events, and, in the absence of tidal currents, locally and to a much smaller degree by inertial oscillations; (5) along the ice edge, the curl of the ice drift is highly correlated with that of surface currents, mostly reflecting the impact of ocean eddies. Where ocean eddies occur and the ice is relatively thin, ice velocity is characterized by enhanced relative vorticity, largely matching that of surface currents. Along the ice edge, ocean eddies produce distinct ice filaments, the realism of which is largely confirmed by high-resolution satellite passive-microwave data.
Ghoshal, P. K.; Pastor, O.; Kashy, D.; ...
2014-12-18
The torus magnet for the CLAS12 spectrometer is a 3.6 T superconducting magnet being designed and built as part of the Jefferson Lab 12 GeV Upgrade. The magnet consists of six coil case assemblies mounted to a cold central hub. The coil case assembly consists of an aluminum case and cover enclosing an epoxy vacuum impregnated coil pack. The coil pack consists of a 117 turn double-pancake winding wrapped with 2 layers of 0.635 mm thick copper cooling sheets. The coil case assembly is cooled by supercritical helium at 4.6 K. This report details the structural analysis of the coilmore » case assembly and the assessment of the coil pack stresses. For the normal operation of the torus magnet, the coil case assembly was analyzed for cool down to 4.6 K and the Lorentz forces at normal operating current. In addition to the normal operating configuration, the coil case assembly was analyzed for Lorentz forces arising from coil misalignment and current imbalances. The allowable stress criteria for the magnet followed the approach of the ASME codes. Primary stresses were limited to the lesser of 2/3 times the yield strength or 1/3 times the ultimate tensile strength. Primary plus secondary stresses were limited to 3 times the primary stress allowable. The analysis was performed using ANSYS Maxwell to calculate the magneto-static loads and ANSYS Mechanical to calculate the stresses.« less
Effect of windbreaks on wind speed and canker incidence on grapefruit
USDA-ARS?s Scientific Manuscript database
For fresh grapefruit, the goal is to maximize pack-out by minimizing canker lesions on fruit. The objective of these trials was to determine the relationship between wind speed and incidence and severity of citrus canker on 5 to 7 yr-old Ruby Red grapefruit trees located in two trial blocks (~4.5 ha...
Effect of windbreaks on wind speed and citrus canker incidence on grapefruit
USDA-ARS?s Scientific Manuscript database
For fresh grapefruit the goal is to maximize pack-out by minimizing canker lesions on fruit. The objective of these trials was to determine the relationship between wind speed and incidence and severity of citrus canker on 5 to 7 yr-old ‘Ruby Red’ grapefruit trees located in two trial blocks (~4.5 h...
Effect of windbreaks on wind speed and canker incidence and severity on grapefruit
USDA-ARS?s Scientific Manuscript database
For fresh grapefruit the goal is to maximize pack-out by minimizing canker lesions on fruit. The objective of these trials was to determine the relationship between wind speed and incidence and severity of canker on 5 to 7 yr-old Ruby Red grapefruit trees located in two trial blocks (~4.5 ha) surrou...
Turbulent aerosol fluxes over the Arctic Ocean: 2. Wind-driven sources from the sea
NASA Astrophysics Data System (ADS)
Nilsson, E. D.; Rannik, Ü.; Swietlicki, E.; Leck, C.; Aalto, P. P.; Zhou, J.; Norman, M.
2001-12-01
An eddy-covariance flux system was successfully applied over open sea, leads and ice floes during the Arctic Ocean Expedition in July-August 1996. Wind-driven upward aerosol number fluxes were observed over open sea and leads in the pack ice. These particles must originate from droplets ejected into the air at the bursting of small air bubbles at the water surface. The source flux F (in 106 m-2 s-1) had a strong dependency on wind speed, log>(F>)=0.20U¯-1.71 and 0.11U¯-1.93, over the open sea and leads, respectively (where U¯ is the local wind speed at about 10 m height). Over the open sea the wind-driven aerosol source flux consisted of a film drop mode centered at ˜100 nm diameter and a jet drop mode centered at ˜1 μm diameter. Over the leads in the pack ice, a jet drop mode at ˜2 μm diameter dominated. The jet drop mode consisted of sea-salt, but oxalate indicated an organic contribution, and bacterias and other biogenic particles were identified by single particle analysis. Particles with diameters less than -100 nm appear to have contributed to the flux, but their chemical composition is unknown. Whitecaps were probably the bubble source at open sea and on the leads at high wind speed, but a different bubble source is needed in the leads owing to their small fetch. Melting of ice in the leads is probably the best candidate. The flux over the open sea was of such a magnitude that it could give a significant contribution to the condensation nuclei (CCN) population. Although the flux from the leads were roughly an order of magnitude smaller and the leads cover only a small fraction of the pack ice, the local source may till be important for the CCN population in Arctic fogs. The primary marine aerosol source will increase both with increased wind speed and with decreased ice fraction and extent. The local CCN production may therefore increase and influence cloud or fog albedo and lifetime in response to greenhouse warming in the Arctic Ocean region.
Wada, Hiroshi; Masumoto-Kubo, Chisato; Gholipour, Yousef; Nonami, Hiroshi; Tanaka, Fukuyo; Erra-Balsells, Rosa; Tsutsumi, Koichi; Hiraoka, Kenzo; Morita, Satoshi
2014-01-01
Foehn-like extreme hot and dry wind conditions (34°C, >2.5 kPa vapor pressure deficit, and 7 m s(-1)) strongly affect grain quality in rice (Oryza sativa L.). This is a current concern because of the increasing frequency and intensity of combined heat and water-deficit stress under climate change. Foehn-induced dry wind conditions during the grain-filling stage increase ring-shaped chalkiness as a result of spatiotemporal reduction in starch accumulation in the endosperm, but kernel growth is sometimes maintained by osmotic adjustment. Here, we assess the effects of dry wind on chalky ring formation in environmentally controlled growth chambers. Our results showed that hot and dry wind conditions that lasted for >24 h dramatically increased chalky ring formation. Hot and dry wind conditions temporarily reduced panicle water potential to -0.65 MPa; however, kernel growth was maintained by osmotic adjustment at control levels with increased transport of assimilate to the growing kernels. Dynamic tracer analysis with a nano-electrospray-ionization Orbitrap mass spectrometer and quantitative polymerase chain reaction analysis revealed that starch degradation was negligible in the short-term treatment. Overall expression of starch synthesis-related genes was found to be down-regulated at moderately low water potential. Because the events observed at low water potential preceded the packing of starch granules in cells, we concluded that reduced rates of starch biosynthesis play a central role in the events of cellular metabolism that are altered at osmotic adjustment, which leads to chalky ring formation under short-term hot and dry wind conditions.
Breakup of Pack Ice, Antarctic Ice Shelf
NASA Technical Reports Server (NTRS)
1991-01-01
Breakup of Pack Ice along the periphery of the Antarctic Ice Shelf (53.5S, 3.0E) produced this mosaic of ice floes off the Antarctic Ice Shelf. Strong offshore winds, probably associated with strong katabatic downdrafts from the interior of the continent, are seen peeling off the edges of the ice shelf into long filamets of sea ice, icebergs, bergy bits and growlers to flow northward into the South Atlantic Ocean. 53.5S, 3.0E
Breakup of Pack Ice, Antarctic Ice Shelf
1991-09-18
STS048-152-007 (12-18 Sept 1991) --- The periphery of the Antarctic ice shelf and the Antarctic Peninsula were photographed by the STS 48 crew members. Strong offshore winds, probably associated with katabatic winds from the interior of the continent, are peeling off the edges of the ice shelf into ribbons of sea ice, icebergs, bergy bits and growlers into the cold waters of the circum-Antarctic southern ocean.
Fast charge implications: Pack and cell analysis and comparison
NASA Astrophysics Data System (ADS)
Tanim, Tanvir R.; Shirk, Matthew G.; Bewley, Randy L.; Dufek, Eric J.; Liaw, Bor Yann
2018-03-01
This study investigates the effect of 50-kW (about 2C) direct current fast charging on a full-size battery electric vehicle's battery pack in comparison to a pack exclusively charged at 3.3 kW, which is the common alternating current Level 2 charging power level. Comparable scaled charging protocols are also independently applied to individual cells at three different temperatures, 20 °C, 30 °C, and 40 °C, to perform a comparative analysis with the packs. Dominant cell-level aging modes were identified through incremental capacity analysis and compared with full packs to gain a clear understanding of additional key factors that affect pack aging. While the cell-level study showed a minor impact on performance due to direct current fast charging, the packs showed a significantly higher rate of capacity fade under similar charging protocols. This indicates that pack-level aging cannot be directly extrapolated from cell evaluation. Delayed fast charging, completing shortly before discharge, was found to have less of an impact on battery degradation than conventional alternating current Level 2 charging.
Ship-borne measurements of aerosol optical depth over remote oceans and its dependence on wind speed
NASA Astrophysics Data System (ADS)
Smirnov, A.; Sayer, A. M.; Holben, B. N.; Hsu, N. C.; Sakerin, S. M.; Macke, A.; Nelson, N. B.; Courcoux, Y.; Smyth, T. J.; Croot, P. L.; Quinn, P.; Sciare, J.; Gulev, S. K.; Piketh, S.; Losno, R.; Kinne, S. A.; Radionov, V. F.
2011-12-01
Aerosol production sources over the World Ocean and various factors determining aerosol spatial and temporal distribution are important for understanding the Earth's radiation budget and aerosol-cloud interactions. Sea-salt aerosol production, being a major source of aerosol over remote oceans, depends on surface wind speed. Recently in a number of publications the effect of wind speed on aerosol optical depth (AOD) has been presented utilizing coastal, island-based and satellite-based AOD measurements. However, the influence of wind speed on the columnar optical depth is still poorly understood, because not all factors and precursors influencing AOD dependence can be accounted for. The Maritime Aerosol Network (a component of AERONET) data archive provides an excellent opportunity to analyze in depth a relationship between ship-based AOD measurements and wind speed. We considered only data presumably not influenced by urban/industrial continental sources, dust outbreaks, biomass burning, or glaciers and pack ice. Additional restrictions imposed on the data set were acceptance of only points taken not closer than two degrees from the nearest landmass. We present analyses on the effect of surface (deck-level) wind speed (acquired onboard, modeled by NCEP, measured from satellite) on AOD and its spectral dependence. Latitudinal comparison of measured onboard and modeled wind speeds showed relatively small bias, which was higher at high latitudes. Instantaneous AOD measurements and daily means yielded similar relationships with various wind speed subsets (instantaneous ship-based and NCEP, averaged over previous 24 hours, steady, satellite retrieved). We compared regression statistics of optical parameters versus wind speed presented in various papers and based on various satellite and sunphotometer measurements. Overall, despite certain scatter, the current work and a majority of publications showed consistent patterns, with the AOD versus wind speed (range 2-16 m/s) dependence close to linear.
Wada, Hiroshi; Masumoto-Kubo, Chisato; Gholipour, Yousef; Nonami, Hiroshi; Tanaka, Fukuyo; Erra-Balsells, Rosa; Tsutsumi, Koichi; Hiraoka, Kenzo; Morita, Satoshi
2014-01-01
Foehn-like extreme hot and dry wind conditions (34°C, >2.5 kPa vapor pressure deficit, and 7 m s−1) strongly affect grain quality in rice (Oryza sativa L.). This is a current concern because of the increasing frequency and intensity of combined heat and water-deficit stress under climate change. Foehn-induced dry wind conditions during the grain-filling stage increase ring-shaped chalkiness as a result of spatiotemporal reduction in starch accumulation in the endosperm, but kernel growth is sometimes maintained by osmotic adjustment. Here, we assess the effects of dry wind on chalky ring formation in environmentally controlled growth chambers. Our results showed that hot and dry wind conditions that lasted for >24 h dramatically increased chalky ring formation. Hot and dry wind conditions temporarily reduced panicle water potential to –0.65 MPa; however, kernel growth was maintained by osmotic adjustment at control levels with increased transport of assimilate to the growing kernels. Dynamic tracer analysis with a nano-electrospray-ionization Orbitrap mass spectrometer and quantitative polymerase chain reaction analysis revealed that starch degradation was negligible in the short-term treatment. Overall expression of starch synthesis-related genes was found to be down-regulated at moderately low water potential. Because the events observed at low water potential preceded the packing of starch granules in cells, we concluded that reduced rates of starch biosynthesis play a central role in the events of cellular metabolism that are altered at osmotic adjustment, which leads to chalky ring formation under short-term hot and dry wind conditions. PMID:25330305
How changes in top water bother big turning packs of up-going wet air
NASA Astrophysics Data System (ADS)
Wood, K.
2017-12-01
Big turning packs of up-going wet air form near areas of warm water at the top of big bodies of water. After these turning packs form, they usually get stronger if the top water stays warm. If the top water becomes less warm, the turning packs usually get less strong. Other things can change how strong a turning pack gets, like how wet the air around it is and if that air moves faster higher up than lower down. When these turning packs hit land, their rain and winds can hurt people and the stuff they own, especially if the turning pack is really strong. But it's hard to know how much stronger or less strong it will become before it hits land. Warm top water gives a turning pack of up-going wet air a lot of power, but cool top water doesn't, so we need to know how warm the top water is. Because I can't go into every turning pack myself, flying computers in outer space tell me what the top water is doing. I look at the top water near turning packs that get strong and see how it's different from the top water near those that get less strong. Top water that changes from warm to cool in a small area bothers a turning pack of up-going wet air, which then gets less strong. If we see these top water changes ahead of time, that might help us know what a turning pack will do before it gets close to land.
NASA Astrophysics Data System (ADS)
Andreeva, T.; Bräuer, T.; Bykov, V.; Egorov, K.; Endler, M.; Fellinger, J.; Kißlinger, J.; Köppen, M.; Schauer, F.
2015-06-01
Wendelstein 7-X, currently under commissioning at the Max-Planck-Institut für Plasmaphysik in Greifswald, Germany, is a modular advanced stellarator, combining the modular coil concept with optimized properties of the plasma. Most of the envisaged magnetic configurations of the machine are rather sensitive to symmetry breaking perturbations which are the consequence of unavoidable manufacturing and assembly tolerances. This overview describes the successive tracking of the Wendelstein 7-X magnet system geometry starting from the manufacturing of the winding packs up to the modelling of the influence of operation loads. The deviations found were used to calculate the resulting error fields and to compare them with the compensation capacity of the trim coils.
Pinsky, Paul F; Kramer, Barnett S
2015-11-01
Based on current recommendations, 30+ pack-years of smoking are required for eligibility for low-dose CT (LDCT) lung cancer screening; former smokers must have quit within 15 years. We investigated whether current smokers with 20 to 29 pack-years have similar lung cancer risks as eligible former smokers and also whether they have a different demographic profile. The Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) was a randomly assigned screening trial of subjects age 55 to 74 years with chest radiographs (CXR) used for lung cancer. Subjects completed a baseline questionnaire containing smoking history questions. Cox proportional hazards models, adjusted for age and sex, were utilized to estimate hazard ratios (HRs) for various smoking history groups. Next, we utilized the National Health Interview Survey (NHIS), which inquired about smoking history and race/ethnicity, to analyze the demographic profiles of various high-risk smoking history categories. All statistical tests were two-sided. The PLCO cohort included 18 114 former and 12 243 current LDCT-eligible smokers, plus 2283 20- to 29-pack-year current smokers. The hazard ratio for 20- to 29-pack-year current smokers compared with eligible (30+ pack-year) former smokers was 1.07 (95% confidence interval [CI] = 0.75 to 1.5). Based on the NHIS, 10 million persons in the United States are currently LDCT eligible; an additional 1.6 million (16%, 95% CI = 13.6% to 19.0%) are 20- to 29-pack-year current smokers. The percentage increase in eligibles if 20- to 29-pack-year current smokers were included was substantially greater for women than men (22.2%, 95% CI = 17.9% to 26.7%; vs 12.2%, 95% CI = 9.3% to 15.3%, P < .001) and for minorities than non-Hispanic whites (30.0%, 95% CI = 24.2% to 36.0%; vs 14.1%, 95% CI = 11.1% to 17.0%, P < .001). The potential benefits and harms of recommending LDCT screening for 20 to 29-pack-year current smokers should be assessed. Published by Oxford University Press 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.
NASA Technical Reports Server (NTRS)
Dahl, Milo D.; Woodward, Richard P.
1990-01-01
The test section of the NASA Lewis 9- by 15-Foot Low-Speed Wind Tunnel was acoustically treated to allow the measurement of sound under simulated free-field conditions. The treatment was designed for high sound absorption at frequencies above 250 Hz and for withstanding the environmental conditions in the test section. In order to achieve the design requirements, a fibrous, bulk-absorber material was packed into removable panel sections. Each section was divided into two equal-depth layers packed with material to different bulk densities. The lower density was next to the facing of the treatment. The facing consisted of a perforated plate and screening material layered together. Sample tests for normal-incidence acoustic absorption were also conducted in an impedance tube to provide data to aid in the treatment design. Tests with no airflow, involving the measurement of the absorptive properties of the treatment installed in the 9- by 15-foot wind tunnel test section, combined the use of time-delay spectrometry with a previously established free-field measurement method. This new application of time-delay spectrometry enabled these free-field measurements to be made in nonanechoic conditions. The results showed that the installed acoustic treatment had absorption coefficients greater than 0.95 over the frequency range 250 Hz to 4 kHz. The measurements in the wind tunnel were in good agreement with both the analytical prediction and the impedance tube test data.
Code of Federal Regulations, 2012 CFR
2012-07-01
... conduit box when specified. A motor assembly is comprised of one or more explosion-proof enclosures. Plane.... A metallic enclosure used as a winding compartment, conduit box, or a combination of both that... portions. Stuffing box. An entrance with a recess filled with packing material for cables extending through...
Code of Federal Regulations, 2011 CFR
2011-07-01
... conduit box when specified. A motor assembly is comprised of one or more explosion-proof enclosures. Plane.... A metallic enclosure used as a winding compartment, conduit box, or a combination of both that... portions. Stuffing box. An entrance with a recess filled with packing material for cables extending through...
Code of Federal Regulations, 2013 CFR
2013-07-01
... conduit box when specified. A motor assembly is comprised of one or more explosion-proof enclosures. Plane.... A metallic enclosure used as a winding compartment, conduit box, or a combination of both that... portions. Stuffing box. An entrance with a recess filled with packing material for cables extending through...
NASA Technical Reports Server (NTRS)
Zwally, J.
1988-01-01
The ongoing work has established the basis for using multiyear sea ice concentrations from SMMR passive microwave for studies of largescale advection and convergence/divergence of the Arctic sea ice pack. Comparisons were made with numerical model simulations and buoy data showing qualitative agreement on daily to interannual time scales. Analysis of the 7-year SMMR data set shows significant interannual variations in the total area of multiyear ice. The scientific objective is to investigate the dynamics, mass balance, and interannual variability of the Arctic sea ice pack. The research emphasizes the direct application of sea ice parameters derived from passive microwave data (SMMR and SSMI) and collaborative studies using a sea ice dynamics model. The possible causes of observed interannual variations in the multiyear ice area are being examined. The relative effects of variations in the large scale advection and convergence/divergence within the ice pack on a regional and seasonal basis are investigated. The effects of anomolous atmospheric forcings are being examined, including the long-lived effects of synoptic events and monthly variations in the mean geostrophic winds. Estimates to be made will include the amount of new ice production within the ice pack during winter and the amount of ice exported from the pack.
NASA Astrophysics Data System (ADS)
Amiribavandpour, Parisa; Shen, Weixiang; Mu, Daobin; Kapoor, Ajay
2015-06-01
A theoretical electrochemical thermal model combined with a thermal resistive network is proposed to investigate thermal behaviours of a battery pack. The combined model is used to study heat generation and heat dissipation as well as their influences on the temperatures of the battery pack with and without a fan under constant current discharge and variable current discharge based on electric vehicle (EV) driving cycles. The comparison results indicate that the proposed model improves the accuracy in the temperature predication of the battery pack by 2.6 times. Furthermore, a large battery pack with four of the investigated battery packs in series is simulated in the presence of different ambient temperatures. The simulation results show that the temperature of the large battery pack at the end of EV driving cycles can reach to 50 °C or 60 °C in high ambient temperatures. Therefore, thermal management system in EVs is required to maintain the battery pack within the safe temperature range.
1995-10-30
STS073-E-5313 (3 Nov. 1995) --- Typhoon Angela packed winds of 115 knots when this shot was taken with an Electronic Still Camera (ESC) from the Earth-orbiting space shuttle Columbia. It subsequently increased to speeds of 155 nautical miles, making it a super typhoon, heading due west toward Luzon in the Philippines.
Modelling MIZ dynamics in a global model
NASA Astrophysics Data System (ADS)
Rynders, Stefanie; Aksenov, Yevgeny; Feltham, Daniel; Nurser, George; Naveira Garabato, Alberto
2016-04-01
Exposure of large, previously ice-covered areas of the Arctic Ocean to the wind and surface ocean waves results in the Arctic pack ice cover becoming more fragmented and mobile, with large regions of ice cover evolving into the Marginal Ice Zone (MIZ). The need for better climate predictions, along with growing economic activity in the Polar Oceans, necessitates climate and forecasting models that can simulate fragmented sea ice with a greater fidelity. Current models are not fully fit for the purpose, since they neither model surface ocean waves in the MIZ, nor account for the effect of floe fragmentation on drag, nor include sea ice rheology that represents both the now thinner pack ice and MIZ ice dynamics. All these processes affect the momentum transfer to the ocean. We present initial results from a global ocean model NEMO (Nucleus for European Modelling of the Ocean) coupled to the Los Alamos sea ice model CICE. The model setup implements a novel rheological formulation for sea ice dynamics, accounting for ice floe collisions, thus offering a seamless framework for pack ice and MIZ simulations. The effect of surface waves on ice motion is included through wave pressure and the turbulent kinetic energy of ice floes. In the multidecadal model integrations we examine MIZ and basin scale sea ice and oceanic responses to the changes in ice dynamics. We analyse model sensitivities and attribute them to key sea ice and ocean dynamical mechanisms. The results suggest that the effect of the new ice rheology is confined to the MIZ. However with the current increase in summer MIZ area, which is projected to continue and may become the dominant type of sea ice in the Arctic, we argue that the effects of the combined sea ice rheology will be noticeable in large areas of the Arctic Ocean, affecting sea ice and ocean. With this study we assert that to make more accurate sea ice predictions in the changing Arctic, models need to include MIZ dynamics and physics.
DNA packing in chromatine, a manifestation of the Bonnet transformation.
Blum, Z; Lidin, S
1988-08-01
The packing of DNA is described using the formalism of differential geometry. Winding of the DNA double helix around the histone 2-5 octamer forming a nucleosome and the condensation of the so-formed bead-on-a-string chromatine aided by histone 1 is interpreted as two consecutive isometric, i.e. Bonnet, transformations. The DNA double helix can be approximated to a helicoid which can be transformed isometrically to a catenoid, an approximation of the nucleosome. Owing to the organization of the histone octamer the extended chromatine takes a helicoidal shape allowing a second Bonnet transformation to consummate the condensation into a chromatine fibre.
On the 2012 Record Low Arctic Sea Ice Cover: Combined Impact of Preconditioning and an August Storm
NASA Technical Reports Server (NTRS)
Parkinson, Claire L.; Comiso, Josefino C.
2013-01-01
A new record low Arctic sea ice extent for the satellite era, 3.4 x 10(exp 6) square kilometers, was reached on 13 September 2012; and a new record low sea ice area, 3.01 x 10(exp 6) square kilometers was reached on the same date. Preconditioning through decades of overall ice reductions made the ice pack more vulnerable to a strong storm that entered the central Arctic in early August 2012. The storm caused the separation of an expanse of 0.4 x 10(exp 6) square kilometers of ice that melted in total, while its removal left the main pack more exposed to wind and waves, facilitating the main pack's further decay. Future summer storms could lead to a further acceleration of the decline in the Arctic sea ice cover and should be carefully monitored.
NASA Astrophysics Data System (ADS)
Davesne, Gautier; Fortier, Daniel; Domine, Florent; Gray, James T.
2017-06-01
We present data on the distribution and thermophysical properties of snow collected sporadically over 4 decades along with recent data of ground surface temperature from Mont Jacques-Cartier (1268 m a.s.l.), the highest summit in the Appalachians of south-eastern Canada. We demonstrate that the occurrence of contemporary permafrost is necessarily associated with a very thin and wind-packed winter snow cover which brings local azonal topo-climatic conditions on the dome-shaped summit. The aims of this study were (i) to understand the snow distribution pattern and snow thermophysical properties on the Mont Jacques-Cartier summit and (ii) to investigate the impact of snow on the spatial distribution of the ground surface temperature (GST) using temperature sensors deployed over the summit. Results showed that above the local treeline, the summit is characterized by a snow cover typically less than 30 cm thick which is explained by the strong westerly winds interacting with the local surface roughness created by the physiography and surficial geomorphology of the site. The snowpack structure is fairly similar to that observed on windy Arctic tundra with a top dense wind slab (300 to 450 kg m-3) of high thermal conductivity, which facilitates heat transfer between the ground surface and the atmosphere. The mean annual ground surface temperature (MAGST) below this thin and wind-packed snow cover was about -1 °C in 2013 and 2014, for the higher, exposed, blockfield-covered sector of the summit characterized by a sporadic herbaceous cover. In contrast, for the gentle slopes covered with stunted spruce (krummholz), and for the steep leeward slope to the south-east of the summit, the MAGST was around 3 °C in 2013 and 2014. The study concludes that the permafrost on Mont Jacques-Cartier, most widely in the Chic-Choc Mountains and by extension in the southern highest summits of the Appalachians, is therefore likely limited to the barren wind-exposed surface of the summit where the low air temperature, the thin snowpack and the wind action bring local cold surface conditions favourable to permafrost development.
NASA Astrophysics Data System (ADS)
Xie, Fei; Zhang, Ge; Pan, Jianwei
2018-02-01
Thin cases and long treating time are shortcomings of conventional duplex treatment of aluminizing followed by nitriding (DTAN). Alternating current field (ACF) enhanced DTAN was carried out on AISI 1045 steel by applying an ACF to treated samples and treating agents with a pair of electrodes for overcoming those shortcomings. By investigating cases' structures, phases, composition and hardness distributions of differently treated samples, preliminary studies were made on characterizations of the ACF enhanced duplex treatment to AISI 1045 steel. The results show that, with the help of the ACF, the surface Al-rich phase Al5Fe2 formed in conventional pack aluminizing can be easily avoided and the aluminizing process is dramatically promoted. The aluminizing case can be nitrided either with conventional pack nitriding or ACF enhanced pack nitriding. By applying ACF to pack nitriding, the diffusion of nitrogen into the aluminizing case is promoted. AlN, Fe2∼3N and solid solution of N in iron are efficiently formed as a result of reactions of N with the aluminizing case. A duplex treated case with an effective thickness of more than 170 μm can be obtained by the alternating current field enhanced 4 h pack aluminizing plus 4 h pack nitriding.
NASA Astrophysics Data System (ADS)
Kizilel, R.; Lateef, A.; Sabbah, R.; Farid, M. M.; Selman, J. R.; Al-Hallaj, S.
A strategy for portable high-power applications with a controlled thermal environment has been developed and has demonstrated the advantage of using the novel phase change material (PCM) thermal management systems over conventional active cooling systems. A passive thermal management system using PCM for Li-ion batteries is tested for extreme conditions, such as ambient temperature of 45 °C and discharge rate of 2.08 C-rate (10 A). Contrary to Li-ion packs without thermal management system, high-energy packs with PCM are discharged safely at high currents and degrading rate of capacity of the Li-ion packs lowered by half. Moreover, the compactness of the packs not only decreases the volume occupied by the packs and its associated complex cooling system, but also decreases the total weight for large power application.
Performance of the Conduction-Cooled LDX Levitation Coil
NASA Astrophysics Data System (ADS)
Michael, P. C.; Schultz, J. H.; Smith, B. A.; Titus, P. H.; Radovinsky, A.; Zhukovsky, A.; Hwang, K. P.; Naumovich, G. J.; Camille, R. J.
2004-06-01
The Levitated Dipole Experiment (LDX) was developed to study plasma confinement in a dipole magnetic field. Plasma is confined in the magnetic field of a 680-kg Nb3Sn Floating Coil (F-coil) that is electromagnetically supported at the center of a 5-m diameter by 3-m tall vacuum chamber. The Levitation Coil (L-coil) is a 2800-turn, double pancake winding that supports the weight of the F-coil and controls its vertical position within the vacuum chamber. The use of high-temperature superconductor (HTS) Bi-2223 for the L-coil minimizes the electrical and cooling power needed for levitation. The L-coil winding pack and support plate are suspended within the L-coil cryostat and cooled by conduction to a single-stage cryocooler rated for 25-W heat load at approximately 20 K. The coil current leads consist of conduction-cooled copper running from room temperature to 80 K and a pair of commercially-available, 150-A HTS leads. An automatically filled liquid-nitrogen reservoir provides cooling for the coil's radiation shield and for the leads' 80-K heat stations. This paper discusses the L-coil system design and its observed cryogenic performance.
MULTIPLE CURRENT SHEET SYSTEMS IN THE OUTER HELIOSPHERE: ENERGY RELEASE AND TURBULENCE
DOE Office of Scientific and Technical Information (OSTI.GOV)
Burgess, D.; Gingell, P. W.; Matteini, L.
2016-05-01
In the outer heliosphere, beyond the solar wind termination shock, it is expected that the warped heliospheric current sheet forms a region of closely packed, multiple, thin current sheets. Such a system may be subject to the ion-kinetic tearing instability, and hence may generate magnetic islands and hot populations of ions associated with magnetic reconnection. Reconnection processes in this environment have important implications for local particle transport, and for particle acceleration at reconnection sites and in turbulence. We study this complex environment by means of three-dimensional hybrid simulations over long timescales, in order to capture the evolution from linear growthmore » of the tearing instability to a fully developed turbulent state at late times. The final state develops from the highly ordered initial state via both forward and inverse cascades. Component and spectral anisotropy in the magnetic fluctuations is present when a guide field is included. The inclusion of a population of newborn interstellar pickup protons does not strongly affect these results. Finally, we conclude that reconnection between multiple current sheets can act as an important source of turbulence in the outer heliosphere, with implications for energetic particle acceleration and propagation.« less
Spatial structure of kinetic energy spectra in LES simulations of flow in an offshore wind farm
NASA Astrophysics Data System (ADS)
Fruh, Wolf-Gerrit; Creech, Angus
2017-04-01
The evolution of wind turbine and wind farm wakes was investigated numerically for the case of Lillgrund wind farm consisting of a tightly packed array of 48 turbines. The simulations for a number of wind directions at a free wind speed of just under the rated wind speed in a neutrally stable atmosphere were carried out using Large-Eddy Simulations with the adaptive Finite-Element CFD solver Fluidity. The results were interpolated from the irregularly spaced mesh nodes onto a regular grid with comparable spatial resolution at horizontal slices at various heights. To investigate the development of the wake as the flow evolves through the array, spectra of the kinetic energy in sections perpendicular to the wind directions within the wake and to the sides of the array were calculated. This paper will present the key features and spectral slopes of the flow as a function of downstream distance from the front turbine through and beyond the array. The main focus will be on the modification of the spectra as the flow crosses a row of turbines followed by its decay in the run-up to the next row, but we will also present to wake decay of the wind farm wake downstream of the array.
Lowry, Kathryn P; Gazelle, G Scott; Gilmore, Michael E; Johanson, Colden; Munshi, Vidit; Choi, Sung Eun; Tramontano, Angela C; Kong, Chung Yin; McMahon, Pamela M
2015-05-15
Lung cancer screening with annual chest computed tomography (CT) is recommended for current and former smokers with a ≥30-pack-year smoking history. Patients with chronic obstructive pulmonary disease (COPD) are at increased risk of developing lung cancer and may benefit from screening at lower pack-year thresholds. We used a previously validated simulation model to compare the health benefits of lung cancer screening in current and former smokers ages 55-80 with ≥30 pack-years with hypothetical programs using lower pack-year thresholds for individuals with COPD (≥20, ≥10, and ≥1 pack-years). Calibration targets for COPD prevalence and associated lung cancer risk were derived using the Framingham Offspring Study limited data set. We performed sensitivity analyses to evaluate the stability of results across different rates of adherence to screening, increased competing mortality risk from COPD, and increased surgical ineligibility in individuals with COPD. The primary outcome was projected life expectancy. Programs using lower pack-year thresholds for individuals with COPD yielded the highest life expectancy gains for a given number of screens. Highest life expectancy was achieved when lowering the pack-year threshold to ≥1 pack-year for individuals with COPD, which dominated all other screening strategies. These results were stable across different adherence rates to screening and increases in competing mortality risk for COPD and surgical ineligibility. Current and former smokers with COPD may disproportionately benefit from lung cancer screening. A lower pack-year threshold for screening eligibility may benefit this high-risk patient population. © 2015 American Cancer Society.
Taussky, P; Kallmes, D F; Cloft, H
2012-05-01
Higher packing attenuation of coils in cerebral aneurysms is associated with a decreased recurrence rate. However, geometric relationships suggest that an additional coil may have very little effect on packing attenuation as aneurysm size increases. We mathematically evaluated the relationship between aneurysm size and incremental packing attenuation for coils currently available.
NASA Astrophysics Data System (ADS)
Pfirman, S.; Tremblay, B.; Fowler, C.
2007-12-01
One hundred years ago, the heroic age of polar exploration was underway. At first glance the Arctic-based Fridtjof Nansen and Antarctic-based Sir Ernest Shackleton, and their most famous expeditions, are literally poles apart. But the expeditions wound up having much in common, including the fact that their fates were largely dependent on their drift trajectory in the sea ice pack and, in Shackleton's case, the wind and ocean currents. These are natural forces, outside the control of the expedition leaders. Were Nansen and Shackleton lucky that the ice and ocean delivered them and their crew to locations from which they could return? Or were their fates more or less inevitable, within the normal range of natural conditions? While we cannot reconstruct the wind and ocean patterns that actually existed 100 years ago to answer this question, we looked at variability over the past three decades to explore potential alternate fates of these expeditions. Our analysis indicates that Nansen and Shackleton were both lucky and unlucky in the natural conditions that they encountered during their expeditions. Most years since 1979, Nansen would have gotten much closer to the North Pole - his goal -- than his ship did in 1895, so he was unlucky in that respect. On the other hand, he was lucky with the relatively short drift duration of his ship in the Arctic pack ice. Shackleton was also lucky in the rapid pace of drift within the pack. The fact that his trajectory was so far to the west might have been a factor in the crushing and sinking of his ship, but it did allow him to land most of his men on Elephant Island while he went for help. Shackleton's heroic, and harrowing, boat journey to South Georgia turned out to be helped by prevailing conditions: it was within the likely ocean drift trajectory from Elephant Island. Analyses such as these, including "Nansen's Luck" by Roger Colony, and "The Coldest March" by Susan Solomon, help set history and profiles of leadership within a scientific framework, engaging an interdisciplinary suite of scholars, students and the general public in understanding the role of the environment, environmental variability, and environmental change.
Unit: Seashores, Inspection Pack, National Trial Print.
ERIC Educational Resources Information Center
Australian Science Education Project, Toorak, Victoria.
As a part of the unit materials in the series produced by the Australian Science Education Project, this teacher edition is primarily composed of three parts: a core, a number of options, and test forms. The core is concerned with seashores, wind, waves, life on seashores, and rocky shore ecosystems. Options are given under the headings: Pollution…
Island in Crisis: Response to Puerto Rico
ERIC Educational Resources Information Center
Zenere, Frank J.
2018-01-01
On September 6, 2017, Hurricane Irma, a Category 5 storm packing winds of 185 miles per hour skirted the northern coast of Puerto Rico, leaving 1 million residents without electrical power. Schools were closed for 5 days, but a major calamity was narrowly avoided. Overall, residents were grateful for their good fortune, but the same could not be…
NASA Astrophysics Data System (ADS)
Trautz, A.; Smits, K. M.; Cihan, A.; Wallen, B.
2014-12-01
Soil-water evaporation is one of the governing processes responsible for controlling water and energy exchanges between the land and atmosphere. Despite its wide relevance and application in many natural and manmade environments (e.g. soil tillage practices, wheel-track compaction, fire burn environments, textural layering and buried ordinances), there are very few studies of evaporation from disturbed soil profiles. The purpose of this study was to explore the effect of soil disturbance and capillary coupling on water distribution and fluxes. We modified a theory previously developed by the authors that allows for coupling single-phase (gas), two-component (air and water vapor) transfer in the atmosphere and two-phase (gas, liquid), two-component (air and water vapor) flow in porous media at the REV scale under non-isothermal, non-equilibrium conditions to better account for the hydraulic and thermal interactions within the media. Modeling results were validated and compared using precision data generated in a two-dimensional soil tank consisting of a loosely packed soil surrounded by a tightly packed soil. The soil tank was outfitted with an array of sensors for the measurement of wind velocity, soil and air temperature, relative humidity, soil moisture, and weight. Results demonstrated that, by using this coupling approach, it is possible to predict the different stages of the drying process in heterogeneous soils with good accuracy. Evaporation from a heterogeneous soil consisting of a loose and tight packing condition is larger than the homogeneous equivalent systems. Liquid water is supplied from the loosely packed soil region to the tightly packed soil regions, sustaining a longer Stage I evaporation in the tightly packed regions with overall greater evaporation rate than uniform homogeneous packing. In contrast, lower evaporation rates from the loosely packed regions are observed due to a limited liquid water supply resulting from capillary flow to the tightly packed regions and a shorter stage 1 evaporation period.
Atmospheric forcing of sea ice leads in the Beaufort Sea
NASA Astrophysics Data System (ADS)
Lewis, B. J.; Hutchings, J.; Mahoney, A. R.; Shapiro, L. H.
2016-12-01
Leads in sea ice play an important role in the polar marine environment where they allow heat and moisture transfer between the oceans and atmosphere and act as travel pathways for both marine mammals and ships. Examining AVHRR thermal imagery of the Beaufort Sea, collected between 1994 and 2010, sea ice leads appear in repeating patterns and locations (Eicken et al 2005). The leads, resolved by AVHRR, are at least 250m wide (Mahoney et al 2012), thus the patterns described are for lead systems that extend up to hundreds of kilometers across the Beaufort Sea. We describe how these patterns are associated with the location of weather systems relative to the coastline. Mean sea level pressure and 10m wind fields from ECMWF ERA-Interim reanalysis are used to identify if particular lead patterns can be uniquely forecast based on the location of weather systems. Ice drift data from the NSIDC's Polar Pathfinder Daily 25km EASE-Grid Sea Ice Motion Vectors indicates the role shear along leads has on the motion of ice in the Beaufort Gyre. Lead formation is driven by 4 main factors: (i) coastal features such as promontories and islands influence the origin of leads by concentrating stresses within the ice pack; (ii) direction of the wind forcing on the ice pack determines the type of fracture, (iii) the location of the anticyclone (or cyclone) center determines the length of the fracture for certain patterns; and (iv) duration of weather conditions affects the width of the ice fracture zones. Movement of the ice pack on the leeward side of leads originating at promontories and islands increases, creating shear zones that control ice transport along the Alaska coast in winter. . Understanding how atmospheric conditions influence the large-scale motion of the ice pack is needed to design models that predict variability of the gyre and export of multi-year ice to lower latitudes.
Potential environmental effects of pack stock on meadow ecosystems of the Sierra Nevada, USA
Ostoja, Steven M.; Brooks, Matthew L.; Moore, Peggy E.; Berlow, Eric L.; Robert Blank,; Roche, Jim; Chase, Jennifer T.; Sylvia Haultain,
2014-01-01
Pack and saddle stock, including, but not limited to domesticated horses, mules, and burros, are used to support commercial, private and administrative activities in the Sierra Nevada. The use of pack stock has become a contentious and litigious issue for land management agencies in the region inter alia due to concerns over effects on the environment. The potential environmental effects of pack stock on Sierra Nevada meadow ecosystems are reviewed and it is concluded that the use of pack stock has the potential to influence the following: (1) water nutrient dynamics, sedimentation, temperature, and microbial pathogen content; (2) soil chemistry, nutrient cycling, soil compaction and hydrology; (3) plant individuals, populations and community dynamics, non-native invasive species, and encroachment of woody species; and (4) wildlife individuals, populations and communities. It is considered from currently available information that management objectives of pack stock should include the following: minimise bare ground, maximise plant cover, maintain species composition of native plants, minimise trampling, especially on wet soils and stream banks, and minimise direct urination and defecation by pack stock into water. However, incomplete documentation of patterns of pack stock use and limited past research limits current understanding of the effects of pack stock, especially their effects on water, soils and wildlife. To improve management of pack stock in this region, research is needed on linking measurable monitoring variables (e.g. plant cover) with environmental relevancy (e.g. soil erosion processes, wildlife habitat use), and identifying specific environmental thresholds of degradation along gradients of pack stock use in Sierra Nevada meadows.
Mechanical Characterization of the Iter Mock-Up Insulation after Reactor Irradiation
NASA Astrophysics Data System (ADS)
Prokopec, R.; Humer, K.; Fillunger, H.; Maix, R. K.; Weber, H. W.
2010-04-01
The ITER mock-up project was launched in order to demonstrate the feasibility of an industrial impregnation process using the new cyanate ester/epoxy blend. The mock-up simulates the TF winding pack cross section by a stainless steel structure with the same dimensions as the TF winding pack at a length of 1 m. It consists of 7 plates simulating the double pancakes, each of them is wrapped with glass fiber/Kapton sandwich tapes. After stacking the 7 plates, additional insulation layers are wrapped to simulate the ground insulation. This paper presents the results of the mechanical quality tests on the mock-up pancake insulation. Tensile and short beam shear specimens were cut from the plates extracted from the mock-up and tested at 77 K using a servo-hydraulic material testing device. All tests were repeated after reactor irradiation to a fast neutron fluence of 1×1022 m-2 (E>0.1 MeV). In order to simulate the pulsed operation of ITER, tension-tension fatigue measurements were performed in the load controlled mode. Initial results show a high mechanical strength as expected from the high number of thin glass fiber layers, and an excellent homogeneity of the material.
NASA Astrophysics Data System (ADS)
2008-11-01
WE RECOMMEND Ideas, Evidence and Argument in Science Fantastic DVD packed with classroom activities LabQuest Datalogger hits all the right buttons The Complete Idiot's Guide to String Theory A book that is better than its title lets on Light Strip SEP proves yet again that simple equipment is best Teaching Radioactivity Multimedia resource gets hands-on with radioactivity WORTH A LOOK Sunshine DVD of the sci-fi film includes insightful commentary track Peltier Cell Unit SEP equipment is useful but unusually pricey 100 Things to Spot in the Night Sky Data cards are packed with astronomical facts Light Sensor SEP unit is only useful for one specific experiment Windmill Generator Classroom-sized windmill does not sell wind power The Number Devil A 'mathematical adventure' book for young children
NASA Astrophysics Data System (ADS)
Baumeister, Dayna Marie
My research examines the relative importance of interacting mechanisms (amelioration of wind, provision of shade, accumulation of snow pack, and alteration of soil characteristics) governing facilitation between Pinus flexilis and two understory species, Pseudotsuga menziesii and Ribes cereum in Montana. Survival of understory species was greatest beneath P. flexilis at a leeward site (Pseudotsuga, 38% and Ribes, 63%), and lowest in the open at a windward site (2% and 6%, respectively). The effects of wind amelioration, shade provision, and snowdrift accumulation were separated experimentally and after two years, shade was of overwhelming importance for the survival of both species. Once shade was provided, effects of wind amelioration and increased snow pack increased survival, suggesting a hierarchical functioning of mechanisms. High winter mortality of Pseudotsuga suggests P. flexilis canopies may prevent photoinhibition and winter desiccation through reduction of light and insulation from variable temperatures. High summer mortality of Ribes suggests P. flexilis canopies may reduce transpiration through lowering leaf temperatures, thereby decreasing vapor pressure deficits. In this system, several mechanisms governing facilitation operated simultaneously, but in a hierarchical manner of relative importance thereby determining the overall effect of P. flexilis on understory plants. I also studied facilitation and secondary succession by examining understory species composition beneath individual P. flexilis and in P. flexilis stands. As P. flexilis trees and stands aged, understory species richness increased, as did cover of forbs and shrubs, but cover of grasses decreased. Stands currently dominated by P. flexilis are shifting towards dominance by Pseudotsuga primarily in mesic sites, with corresponding increases in litter and shrub cover and decreases in grasses and P. flexilis recruitment. Since the 1860's succession from grasslands to forest on the Front has been characterized by invasion of P. flexilis and subsequent shifts in understory species composition apparently facilitated by P. flexilis. Lastly, I examined the role of the emerging science of biomimicry in providing employment for biologists. Biomimicry as a discipline seeks design solutions inspired by nature. Industries employing this tool require biologists with an understanding of biology from a functional perspective, good communication skills, and a background in applied natural history.
NASA Astrophysics Data System (ADS)
Gadkari, Siddharth; Gu, Sai
2018-06-01
A two-dimensional numerical fluid model is developed for studying the influence of packing configurations on dielectric barrier discharge (DBD) characteristics. Discharge current profiles and time averaged electric field strength, electron number density, and electron temperature distributions are compared for the three DBD configurations, plain DBD with no packing, partially packed DBD, and fully packed DBD. The results show that a strong change in discharge behaviour occurs when a DBD is fully packed as compared to partial packing or no packing. While the average electric field strength and electron temperature of a fully packed DBD are higher relative to the other DBD configurations, the average electron density is substantially lower and may impede the DBD reactor performance under certain operating conditions. Possible scenarios of the synergistic effect of the combination of plasma with catalysis are also discussed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Seidl, P. A.; Waldron, W.
This report describes the prototype final focus solenoid (FFS-1G), or 1st generation FFS. In order to limit eddy currents, the solenoid winding consists of Litz wire wound on a non-conductive G-10 tube. For the same reason, the winding pack was inserted into an electrically insulating, but thermally conducting Polypropylene (Cool- Poly© D1202) housing and potted with highly viscous epoxy (to be able to wick the single strands of the Litz wire). The magnet is forced-air cooled through cooling channels. The magnet was designed for water cooling, but he cooling jacket cracked, and therefore cooling (beyond natural conduction and radiation) wasmore » exclusively by forced air. Though the design operating point was 8 Tesla, for the majority of running on NDCX-1 it operated up to about 5 Tesla. This was due mostly from limitations of voltage holding at the leads, where discharges at higher pulsed current damaged the leads. Generation 1 was replaced by the 2nd generation solenoid (FFS-2G) about a year later, which has operated reliably up to 8 Tesla, with a better lead design and utilizes water cooling. At this point, FFS-1G was used for plasma source R&D by LBNL and PPPL. The maximum field for those experiments was reduced to 3 Tesla due to continued difficulty with the leads and because higher field was not essential for those experiments. The pulser for the final focusing solenoid is a SCR-switched capacitor bank which produces a half-sine current waveform. The pulse width is ~800us and a charge voltage of 3kV drives ~20kA through the magnet producing ~8T field.« less
75 FR 31283 - Clarification of Parachute Packing Authorization
Federal Register 2010, 2011, 2012, 2013, 2014
2010-06-03
... system--those with main and ``back up'' parachutes--to be used for parachute jumping in connection with... is not under the supervision of an appropriate current certificated parachute rigger to only pack the... changes to the 2001 revision of the current rule. DATES: This action is effective June 3, 2010. For more...
Influence of orographically steered winds on Mutsu Bay surface currents
NASA Astrophysics Data System (ADS)
Yamaguchi, Satoshi; Kawamura, Hiroshi
2005-09-01
Effects of spatially dependent sea surface wind field on currents in Mutsu Bay, which is located at the northern end of Japanese Honshu Island, are investigated using winds derived from synthetic aperture radar (SAR) images and a numerical model. A characteristic wind pattern over the bay was evidenced from analysis of 118 SAR images and coincided with in situ observations. Wind is topographically steered with easterly winds entering the bay through the terrestrial gap and stronger wind blowing over the central water toward its mouth. Nearshore winds are weaker due to terrestrial blockages. Using the Princeton Ocean Model, we investigated currents forced by the observed spatially dependent wind field. The predicted current pattern agrees well with available observations. For a uniform wind field of equal magnitude and average direction, the circulation pattern departs from observations demonstrating that vorticity input due to spatially dependent wind stress is essential in generation of the wind-driven current in Mutsu Bay.
Noble, Marlene A.; Rosenberger, Kurt; Robertson, George L.
2015-01-01
Contrary to many previous reports, winds do drive currents along the shelf in the central portion of the Southern California Bight (SCB). Winds off Huntington Beach CA are the dominant forcing for currents over the nearshore region of the shelf (water depths less than 20 m). Winds control about 50–70% of the energy in nearshore alongshelf surface currents. The wind-driven current amplitudes are also anomalously high. For a relatively weak 1 dyne/cm2 wind stress, the alongshelf surface current amplitudes in this region can reach 80 cm/s or more. Mid-depth current amplitudes for the same wind stress are around 30–40 cm/s. These wind-driven surface current amplitudes are much larger than previously measured over other nearshore shelf regions, perhaps because this program is one of the few that measured currents within a meter of the surface. The near-bed cross-shelf currents over the nearshore region of the Huntington Beach shelf have an Ekman response to winds in that they upwell (downwell) for down (up) coast winds. This response disappears further offshore. Hence, there is upwelling in the SCB, but it does not occur across the entire shelf. Subthermocline water in the nearshore region that may contain nutrients and plankton move onshore when winds are southeastward, but subthermocline water over the shelf break is not transported to the beach. The currents over the outer shelf are not predominately controlled by winds, consistent with previous reports. Instead, they are mainly driven by cross-shelf pressure gradients that are independent of local wind stress.
2016-10-03
ISS049e028067 (10/03/2016) --- Hurricane Matthew, a huge category 4 level storm, as seen from the International Space Station Oct. 3, 2016. Packing winds of 140 miles an hour as a Category 4 hurricane, Matthew passed over western Haiti and eastern Cuba Oct. 4 before charging north over the Bahamas Oct. 5 and potentially threatening the east coast of the United States later in the week.
Earth observation taken by the Expedition 11 crew
2005-09-11
ISS011-E-12836 (11 September 2005, 19:31:17 GMT) --- This image of Hurricane Ophelia was captured by the Expedition 11 crew aboard the International Space Station on the afternoon September 11, 2005. The hurricane, located at 31.6 degrees north latitude and 75.8 degrees west longitude, was packing winds of 80 miles per hour when the photo was made. (Image credit: NASA)
Using a Chaser to Decrease Packing in Children with Feeding Disorders
ERIC Educational Resources Information Center
Vaz, Petula C. M.; Piazza, Cathleen C.; Stewart, Victoria; Volkert, Valerie M.; Groff, Rebecca A.; Patel, Meeta R.
2012-01-01
Packing is a problematic mealtime behavior that is characterized by pocketing or holding solids or liquids in the mouth without swallowing. In the current study, we examined the effects of a chaser, a liquid or solid consistently accepted and swallowed by the child, to decrease packing of solid foods in 3 children with feeding disorders. During…
cellPACK: A Virtual Mesoscope to Model and Visualize Structural Systems Biology
Johnson, Graham T.; Autin, Ludovic; Al-Alusi, Mostafa; Goodsell, David S.; Sanner, Michel F.; Olson, Arthur J.
2014-01-01
cellPACK assembles computational models of the biological mesoscale, an intermediate scale (10−7–10−8m) between molecular and cellular biology. cellPACK’s modular architecture unites existing and novel packing algorithms to generate, visualize and analyze comprehensive 3D models of complex biological environments that integrate data from multiple experimental systems biology and structural biology sources. cellPACK is currently available as open source code, with tools for validation of models and with recipes and models for five biological systems: blood plasma, cytoplasm, synaptic vesicles, HIV and a mycoplasma cell. We have applied cellPACK to model distributions of HIV envelope protein to test several hypotheses for consistency with experimental observations. Biologists, educators, and outreach specialists can interact with cellPACK models, develop new recipes and perform packing experiments through scripting and graphical user interfaces at http://cellPACK.org. PMID:25437435
Quantifying array losses due to spacing and staggering in offshore wind farms (Invited)
NASA Astrophysics Data System (ADS)
Archer, C. L.; Mirzaeisefat, S.; Lee, S.; Xie, S.
2013-12-01
The layout of wind turbines can have an impact on the power production of a wind farm. Design variables that define the layout of wind turbines within a wind farm include: orientation of the rows with respect to the prevailing wind direction, size and shape of the wind farm, spacing between turbines, and alignment of the turbines (i.e., whether in-line or staggered with one another). There are no universal layout recommendations for offshore wind farms, partly because isolating the contribution of each individual design variable is impossible at existing offshore wind farms, where multiple effects overlap non-linearly on one another, and partly because analyzing the sensitivity to design variables requires sophisticated and computer-intensive numerical codes, such as large-eddy simulations (LES), that can simulate the small-scale turbulent features of turbine wakes. The National Renewable Energy Laboratory (NREL) developed the only publicly available and open-source LES code that is capable of resolving wind turbine blades as rotating actuator lines (not fixed disks), includes both neutral and unstable atmospheric conditions (stable case is currently under development), and does not rely on periodic boundary conditions. This code, named Simulator for Offshore/Onshore Wind Farm Applications (SOWFA), is based on OpenFOAM and has been used successfully in the past for turbulent wake simulations. Here we address the issue of quantifying two design variables: turbine spacing (both along and across the prevailing wind direction) and alignment (in-line or staggered for consecutive rows). SOWFA is used to simulate an existing offshore wind farm in Lillgrund (Sweden), consisting of 48 Siemens 2.3 MW turbines with spacing of 3.2D across and 4.3D along the prevailing wind direction and without staggering, where D is the turbine diameter (93 m). This spacing is exceptionally tight, to our knowledge the tightest of all modern wind farms. While keeping the area and the shape of the farm constant, we design several new Lillgrund farm layouts with and without staggering, with increased spacing in each direction individually and in both directions together, and with various wind directions and atmospheric stabilities. We found that the average wind power generated per turbine is increased by ~32% (from 696 kW to 922 kW) if both staggering and doubling of the across-spacing are implemented simultaneously in a neutral stability case. Wake losses are quantified in terms of average power in the first (upwind) row of wind turbines in the control case, representative of the power that could be generated if there were no wakes, over the average power of all the wind turbines in the farm. Wake losses at Lillgrund are relatively high due to the tight packing, of the order of 35%, but smart combinations of staggering and doubling of turbine spacing can reduce them to 15%-26%. In summary, we provide estimates of the losses/gains associated with individual and combined changes in two design variables, spacing and staggering, under various atmospheric stabilities, wind directions, and wind speeds. These estimates will be useful to the wind industry to optimize a wind project because the effects of alternative layouts can be quantified quickly with respect to total power, capacity factor, and number of wind turbines, all of which can ultimately be converted to actual costs or savings.
Quantifying array losses due to spacing and staggering in offshore wind farms (Invited)
NASA Astrophysics Data System (ADS)
Archer, C. L.; Mirzaeisefat, S.; Lee, S.; Xie, S.
2011-12-01
The layout of wind turbines can have an impact on the power production of a wind farm. Design variables that define the layout of wind turbines within a wind farm include: orientation of the rows with respect to the prevailing wind direction, size and shape of the wind farm, spacing between turbines, and alignment of the turbines (i.e., whether in-line or staggered with one another). There are no universal layout recommendations for offshore wind farms, partly because isolating the contribution of each individual design variable is impossible at existing offshore wind farms, where multiple effects overlap non-linearly on one another, and partly because analyzing the sensitivity to design variables requires sophisticated and computer-intensive numerical codes, such as large-eddy simulations (LES), that can simulate the small-scale turbulent features of turbine wakes. The National Renewable Energy Laboratory (NREL) developed the only publicly available and open-source LES code that is capable of resolving wind turbine blades as rotating actuator lines (not fixed disks), includes both neutral and unstable atmospheric conditions (stable case is currently under development), and does not rely on periodic boundary conditions. This code, named Simulator for Offshore/Onshore Wind Farm Applications (SOWFA), is based on OpenFOAM and has been used successfully in the past for turbulent wake simulations. Here we address the issue of quantifying two design variables: turbine spacing (both along and across the prevailing wind direction) and alignment (in-line or staggered for consecutive rows). SOWFA is used to simulate an existing offshore wind farm in Lillgrund (Sweden), consisting of 48 Siemens 2.3 MW turbines with spacing of 3.2D across and 4.3D along the prevailing wind direction and without staggering, where D is the turbine diameter (93 m). This spacing is exceptionally tight, to our knowledge the tightest of all modern wind farms. While keeping the area and the shape of the farm constant, we design several new Lillgrund farm layouts with and without staggering, with increased spacing in each direction individually and in both directions together, and with various wind directions and atmospheric stabilities. We found that the average wind power generated per turbine is increased by ~32% (from 696 kW to 922 kW) if both staggering and doubling of the across-spacing are implemented simultaneously in a neutral stability case. Wake losses are quantified in terms of average power in the first (upwind) row of wind turbines in the control case, representative of the power that could be generated if there were no wakes, over the average power of all the wind turbines in the farm. Wake losses at Lillgrund are relatively high due to the tight packing, of the order of 35%, but smart combinations of staggering and doubling of turbine spacing can reduce them to 15%-26%. In summary, we provide estimates of the losses/gains associated with individual and combined changes in two design variables, spacing and staggering, under various atmospheric stabilities, wind directions, and wind speeds. These estimates will be useful to the wind industry to optimize a wind project because the effects of alternative layouts can be quantified quickly with respect to total power, capacity factor, and number of wind turbines, all of which can ultimately be converted to actual costs or savings.
The Effects of the Impedance of the Flow Source on the Design of Tidal Stream Generators
NASA Astrophysics Data System (ADS)
Salter, S.
2011-12-01
The maximum performance of a wind turbine is set by the well-known Betz limit. If the designer of a wind turbine uses too fast a rotation, too large a blade chord or too high an angle of blade pitch, the air flow can take an easier path over or around the rotor. Most estimates of the tidal stream resource use equations borrowed from wind and would be reasonably accurate for a single unit. But water cannot flow through the seabed or over rotors which reach to the surface. If contra-rotating, vertical-axis turbines with a rectangular flow-window are placed close to one another and reach from the surface close to the seabed, the leakage path is blocked and they become more like turbines in a closed duct. Instead of an equation with area times velocity-cubed we should use the first power of volume flow rate though the rotor times the pressure difference across it. A long channel with a rough bed will already be losing lots of energy and will behave more like a high impedance flow. Attempts to block it with closely-packed turbines will increase the head across the turbines with only a small effect on flow rate. The same thing will occur if a close-packed line of turbines is built out to sea from a headland. It is necessary to understand the impedance of the flow source all the way out to mid-ocean. In deep seas where the current velocities at the seabed are too slow to disturb the ooze the friction coefficients will be similar to those of gloss paint, perhaps 0.0025. But the higher velocities in shallow water will remove ooze and quite large sediments leaving rough, bare rock and leading to higher friction-coefficients. Energy dissipation will be set by the higher friction coefficients and the cube of the higher velocities. The presence of turbines will reduce seabed losses and about one third of the present loss can be converted to electricity. The velocity reduction would be about 10%. In many sites the energy output will be far higher than the wind turbine equations would predict. It may be possible to measure friction coefficients by looking at the slope of the water across a likely tidal stream site as indicated by the pressure-sensing instruments built in to acoustic Doppler current profilers. If this reasoning is correct it would lead to large changes in turbine design for tidal streams particularly with regard to the very large forces which have to be passed into the seabed. The spacing of three rotor diameters, often recommended for tidal stream turbines becomes the equivalent of leaking pipes in conventional hydro-electric plant. These design changes will be discussed. Reference Salter SH. Correcting the Under-estimate of the Tidal-Stream Resource of the Pentland Firth. 8th European Wave and Tidal Energy Conference, Uppsala 2009 From www.see.ed.ac.uk/~shs then browse to /Tidal stream.
Winding Pack Height Management During Fabrication of the ITER CS Module
NASA Astrophysics Data System (ADS)
Martovetsky, Nicolai N.; Irick, David K.; Reed, Richard P.; Haefelfinger, Rolf; Salazar, Erica
The Central Solenoid (CS) stack consists of six modules, 2.1 m tall each [1]. In order to verify good impregnation, we performed a vacuum pressure impregnation (VPI) test of a full cross section of the CS module (CSM), 40 conductors tall and 14 conductors wide [2]. It was discovered that after preparation of the full cross section stack until completion of the VPI, the stack shrunk in height by 20-25 mm. Our study of the literature and discussions with the leading experts in VPI did not reveal obvious reasons for this change of height, so we launched a study to address this issue. We assembled two 12x1 (tall by wide) arrays and several 7x1 arrays in order to study characteristics of the dry winding pack under compressive force and effects of different fabrication steps. Then we impregnated these arrays in different conditions under compressive force and studied change of height as a result of compression, impregnation, gelling and curing of the stack of insulated conductors. We showed that by controlling the application of the compressive force, before closing the mold and during impregnation, one can reduce the height uncertainty. Most of the height reduction takes place while the glass is dry under the dead weight and the applied compressive force. Reduction of height during injection of the resin and during gelling, curing and cooling of the coil is noticeable, reproducible and relatively small. The paper presents results of our studies and recommendations for assembly and VPI of tall windings.
NASA Astrophysics Data System (ADS)
Huang, Tao; Lühr, Hermann; Wang, Hui; Xiong, Chao
2017-12-01
The relationship between high-latitude ionospheric currents (Hall current and field-aligned current) and thermospheric wind is investigated. The 2-D patterns of horizontal wind and equivalent current in the Northern Hemisphere derived from the CHAMP satellite are considered for the first time simultaneously. The equivalent currents show strong dependences on both interplanetary magnetic field (IMF) By and Bz components. However, IMF By orientation is more important in controlling the wind velocity patterns. The duskside wind vortex as well as the antisunward wind in the morning polar cap is more evident for positive By. To better understand their spatial relation in different sectors, a systematic superposed epoch analysis is applied. Our results show that in the dusk sector, the vectors of the zonal wind and equivalent current are anticorrelated, and both of them form a vortical flow pattern for different activity levels. The currents and zonal wind are intensified with the increase of merging electric field. However, on the dawnside, where the relation is less clear, antisunward zonal winds dominate. Plasma drift seems to play a less important role for the wind than neutral forces in this sector. In the noon sector, the best anticorrelation between equivalent current and wind is observed for a positive IMF By component and it is less obvious for negative By. A clear seasonal effect with current intensities increasing from winter to summer is observed in the noon sector. Different from the currents, the zonal wind intensity shows little dependence on seasons. Our results indicate that the plasma drift and the neutral forces are of comparable influence on the zonal wind at CHAMP altitude in the noon sector.
Bascuñán, Juan; Michael, Philip; Hahn, Seungyong; Lecrevisse, Thibault; Iwasa, Yukikazu
2017-06-01
This paper focuses on the construction and test results of Coil 2 that is part of a trio of nested coils composing the REBCO 800 MHz insert. Upon its completion, the REBCO 800 MHz insert will be placed in the bore of a 500 MHz low temperature superconducting (LTS) NMR magnet (L500) to form the MIT 1.3 GHz high-resolution NMR magnet. Coil 2 is a stack of 32 double pancake (DP) coils wound with 6-mm wide REBCO tape using the no-insulation (NI) technique. Each pancake is wound on a stainless steel inner supporting ring to prevent the collapsing of its crossover due to the external pressure exerted by the winding pack. Coil 2 will be constructed in the following sequence: 1) after winding each DP will be individually tested in a bath of liquid nitrogen at atmospheric pressure to determine its current carrying capabilities; 2) DPs will be then assembled as a stack with interconnecting joints, and 3) as in Coil 1, each pancake will be overbanded with a stainless steel tape, this time to a thickness of 5 mm, thickness determined by a stress analysis previously performed. Finally the fully assembled Coil 2 will be tested in liquid nitrogen at 77 K and then in liquid helium at 4.2 K. We present here details of the stress analysis leading to the sizing of the DP inner supporting stainless steel ring and of the overbanding thickness required. Test results include coil index, critical current, charging time constant.
NASA Astrophysics Data System (ADS)
Turnbull, I. D.; Torbati, R. Z.; Taylor, R. S.
2017-07-01
Understanding the relative influences of the metocean forcings on the drift of sea ice floes is a crucial component to the overall characterization of an ice environment and to developing an understanding of the factors controlling the ice dynamics. In addition, estimating the magnitude of the internal stress gradients on drifting sea ice floes generated by surrounding ice cover is important for modeling operations, informing the design of offshore structures and vessels in ice environments, and for the proper calibration of Discrete Element Models (DEM) of fields of drifting ice floes. In the spring of 2015 and 2016, four sea ice floes offshore Makkovik, Labrador were tagged with satellite-linked ice tracking buoys along with one satellite-linked weather station on each floe to transmit wind speed and direction. Twenty satellite-linked Lagrangian surface ocean current tracking buoys were also deployed in the open water adjacent to the targeted ice floes. In this paper, the dynamics of the four ice floes are explored in terms of the relative proportions which were forced by the wind, current, sea surface topography, Coriolis, and internal stress gradients. The internal ice stress gradients are calculated as residuals between the observed accelerations of the floes as measured by the tracking buoys and the sums of the other metocean forcings. Results show that internal ice stress gradients accounted for up to 50% of the observed forcing on the floes, and may have reached up to around 0.19 kPa.
Seasonal variation of the Beaufort shelfbreak jet and its relationship to Arctic cetacean occurrence
NASA Astrophysics Data System (ADS)
Lin, Peigen; Pickart, Robert S.; Stafford, Kathleen M.; Moore, G. W. K.; Torres, Daniel J.; Bahr, Frank; Hu, Jianyu
2016-12-01
Using mooring time series from September 2008 to August 2012, together with ancillary atmospheric and satellite data sets, we quantify the seasonal variations of the shelfbreak jet in the Alaskan Beaufort Sea and explore connections to the occurrences of bowhead and beluga whales. Wind patterns during the 4 year study period are different from the long-term climatological conditions that the springtime peak in easterly winds shifted from May to June and the autumn peak was limited to October instead of extending farther into the fall. These changes were primarily due to the behavior of the two regional atmospheric centers of action, the Aleutian Low and Beaufort High. The volume transport of the shelfbreak jet, which peaks in the summer, was decomposed into a background (weak wind) component and a wind-driven component. The wind-driven component is correlated to the Pt. Barrow, AK alongcoast wind speed record although a more accurate prediction is obtained when considering the ice thickness at the mooring site. An upwelling index reveals that wind-driven upwelling is enhanced in June and October when storms are stronger and longer-lasting. The seasonal variation of Arctic cetacean occurrence is dominated by the eastward migration in spring, dictated by pack-ice patterns, and westward migration in fall, coincident with the autumn peak in shelfbreak upwelling intensity.
Method and apparatus for producing co-current fluid contact
Trutna, William R.
1997-01-01
An improved packing system and method are disclosed wherein a packing section includes a liquid distributor and a separator placed above the distributor so that gas rising through the liquid distributor contacts liquid in the distributor, forming a gas-liquid combination which rises in co-current flow to the separator. Liquid is collected in the separator, from which gas rises.
Method and apparatus for producing co-current fluid contact
Trutna, W.R.
1997-12-09
An improved packing system and method are disclosed wherein a packing section includes a liquid distributor and a separator placed above the distributor so that gas rising through the liquid distributor contacts liquid in the distributor, forming a gas-liquid combination which rises in co-current flow to the separator. Liquid is collected in the separator, from which gas rises. 13 figs.
NASA Technical Reports Server (NTRS)
Gordon, H. H.; Munday, J. C., Jr.
1977-01-01
In estuaries, the interaction of wind, tidal current, and mixing of fresh and saline water produces a variable depth profile of current, with foam lines and convergence zones between water types. Careful measurement of surface currents via Lagrangian drifters requires a drifter design appropriate to both the depth of current to be measured and the tide and wind conditions of interest. The use of remote sensing to track drifters contributes additional constraints on drifter design. Several designs of biodegradable drifters which emit uranine dye plumes, resolvable in aerial imagery to 1:60,000 scale, were tested for wind drag in field conditions against data from calibrated current meters. A 20 cm-vaned wooden drifter and a window shade drifter set to 1.5 m depth had negligible wind drag in winds to 8 m/sec. Prediction of oil slick trajectories using surface current data and a wind factor should be approached cautiously, as surface current data may be wind-contaminated, while the usual 3.5% wind factor is appropriate only for currents measured at depth.
On wind-wave-current interactions during the Shoaling Waves Experiment
NASA Astrophysics Data System (ADS)
Zhang, Fei W.; Drennan, William M.; Haus, Brian K.; Graber, Hans C.
2009-01-01
This paper presents a case study of wind-wave-current interaction during the Shoaling Waves Experiment (SHOWEX). Surface current fields off Duck, North Carolina, were measured by a high-frequency Ocean Surface Current Radar (OSCR). Wind, wind stress, and directional wave data were obtained from several Air Sea Interaction Spar (ASIS) buoys moored in the OSCR scanning domain. At several times during the experiment, significant coastal currents entered the experimental area. High horizontal shears at the current edge resulted in the waves at the peak of wind-sea spectra (but not those in the higher-frequency equilibrium range) being shifted away from the mean wind direction. This led to a significant turning of the wind stress vector away from the mean wind direction. The interactions presented here have important applications in radar remote sensing and are discussed in the context of recent radar imaging models of the ocean surface.
Infective endocarditis of native valve after anterior nasal packing.
Jayawardena, Suriya; Eisdorfer, Jacob; Indulkar, Shalaka; Zarkaria, Muhammad
2006-01-01
We present a case report of a patient who was previously treated for spontaneous epistaxis with a petroleum jelly gauze (0.5 in x 72 in) anterior nasal packing filled with an antibiotic ointment, along with prophylactic oral clindamycin. The patient presented with fever and hypotension 3 days after the nasal packing. Her blood cultures grew methicillin-resistant Staphylococcus aureus and the transesophageal echocardiography showed vegetation on the atrial surface of the posterior mitral valve leaflet, confirming the diagnosis of bacterial endocarditis attributable to nasal packing. Several case reports discuss toxic shock syndrome after nasal packing, but none describe endocarditis of the native heart valves subsequent to anterior nasal packing. Current guidelines on endocarditis prophylaxis produced by the American Heart Association, European Cardiac Society, and British Cardiac Society together with published evidence do not recommend endocarditis prophylaxis for patients with native heart valves undergoing anterior nasal packing.
Wakefield, M A; Germain, D; Durkin, S J
2008-01-01
Background: Cigarette packaging is a key marketing strategy for promoting brand image. Plain packaging has been proposed to limit brand image, but tobacco companies would resist removal of branding design elements. Method: A 3 (brand types) × 4 (degree of plain packaging) between-subject experimental design was used, using an internet online method, to expose 813 adult Australian smokers to one randomly selected cigarette pack, after which respondents completed ratings of the pack. Results: Compared with current cigarette packs with full branding, cigarette packs that displayed progressively fewer branding design elements were perceived increasingly unfavourably in terms of smokers’ appraisals of the packs, the smokers who might smoke such packs, and the inferred experience of smoking a cigarette from these packs. For example, cardboard brown packs with the number of enclosed cigarettes displayed on the front of the pack and featuring only the brand name in small standard font at the bottom of the pack face were rated as significantly less attractive and popular than original branded packs. Smokers of these plain packs were rated as significantly less trendy/stylish, less sociable/outgoing and less mature than smokers of the original pack. Compared with original packs, smokers inferred that cigarettes from these plain packs would be less rich in tobacco, less satisfying and of lower quality tobacco. Conclusion: Plain packaging policies that remove most brand design elements are likely to be most successful in removing cigarette brand image associations. PMID:18827035
Wakefield, M A; Germain, D; Durkin, S J
2008-12-01
Cigarette packaging is a key marketing strategy for promoting brand image. Plain packaging has been proposed to limit brand image, but tobacco companies would resist removal of branding design elements. A 3 (brand types) x 4 (degree of plain packaging) between-subject experimental design was used, using an internet online method, to expose 813 adult Australian smokers to one randomly selected cigarette pack, after which respondents completed ratings of the pack. Compared with current cigarette packs with full branding, cigarette packs that displayed progressively fewer branding design elements were perceived increasingly unfavourably in terms of smokers' appraisals of the packs, the smokers who might smoke such packs, and the inferred experience of smoking a cigarette from these packs. For example, cardboard brown packs with the number of enclosed cigarettes displayed on the front of the pack and featuring only the brand name in small standard font at the bottom of the pack face were rated as significantly less attractive and popular than original branded packs. Smokers of these plain packs were rated as significantly less trendy/stylish, less sociable/outgoing and less mature than smokers of the original pack. Compared with original packs, smokers inferred that cigarettes from these plain packs would be less rich in tobacco, less satisfying and of lower quality tobacco. Plain packaging policies that remove most brand design elements are likely to be most successful in removing cigarette brand image associations.
Cryosurgery Planning Using Bubble Packing in 3D
Tanaka, Daigo; Shimada, Kenji; Rossi, Michael R.; Rabin, Yoed
2008-01-01
As part of an ongoing project to develop automated tools for cryosurgery planning, the current study focuses on the development of a 3D bubble packing method. A proof-of-concept for the new method is demonstrated on five prostate models, reconstructed from ultrasound images. The new method is a modification of an established method in 2D. Ellipsoidal bubbles are packed in the volume of the prostate in the current study; such bubbles can be viewed as a first-order approximation of a frozen region around a single cryoprobe. When all cryoprobes are inserted to the same depth, optimum planning was found to occur at about 60% of the length of the prostate (measured from its apex), which leads to cooling of approximately 75% of the prostate volume below a specific temperature threshold of −22°C. Bubble packing has the potential to dramatically reduce the run time for automated planning. PMID:17963095
Cryosurgery planning using bubble packing in 3D.
Tanaka, Daigo; Shimada, Kenji; Rossi, Michael R; Rabin, Yoed
2008-04-01
As part of an ongoing project to develop automated tools for cryosurgery planning, the current study focuses on the development of a 3D bubble packing method. A proof-of-concept for the new method is demonstrated on five prostate models, reconstructed from ultrasound images. The new method is a modification of an established method in 2D. Ellipsoidal bubbles are packed in the volume of the prostate in the current study; such bubbles can be viewed as a first-order approximation of a frozen region around a single cryoprobe. When all cryoprobes are inserted to the same depth, optimum planning was found to occur at about 60% of the length of the prostate (measured from its apex), which leads to cooling of approximately 75% of the prostate volume below a specific temperature threshold of - 22 degrees C. Bubble packing has the potential to dramatically reduce the run time for automated planning.
Magnetic Tape Recording for the Eighties
NASA Technical Reports Server (NTRS)
Kalil, Ford (Editor)
1982-01-01
The practical and theoretical aspects of state-of-the-art magnetic tape recording technology are reviewed. Topics covered include the following: (1) analog and digital magnetic tape recording, (2) tape and head wear, (3) wear testing, (4) magnetic tape certification, (5) care, handling, and management of magnetic tape, (6) cleaning, packing, and winding of magnetic tape, (7) tape reels, bands, and packaging, (8) coding techniques for high-density digital recording, and (9) tradeoffs of coding techniques.
Earth Obsersation taken by the Expedition 11 crew
2005-07-07
ISS011-E-10214 (7 July 2005) --- At the time of this Expedition 11 digital still camera's image, Hurricane Dennis was churning northwestward through the Caribbean Sea between Jamaica and eastern Cuba packing winds of up to 115 miles per hour. Even though the hurricane had just attained Category 3 intensity, the eye had not yet cleared. This oblique view, captured with a 70mm lens at 21:12:01 gmt, is looking west.
A single strand of DNA can stretch several meters. Yet dozens of these strands, which can be one-tenth as thin as a human hair, need to fit into the cell’s nucleus. To pack those strands into such a small space, DNA tightly winds itself around histone proteins, forming nucleosomes that are strung together into complexes called chromatin. Beyond efficiently packaging DNA,
Earth observation taken by the Expedition 11 crew
2005-09-11
ISS011-E-12838 (11 September 2005, 19:21:12 GMT) --- Framed by a window on the Destiny lab aboard the Space Station, this image of Hurricane Ophelia was captured by the Expedition 11 crew on the afternoon of September 11, 2005. The hurricane, located at 31.6 degrees north latitude and 75.8 degrees west longitude, was packing winds of 80 miles per hour when the photo was made. (Image credit: NASA)
Nearshore currents on the southern Namaqua shelf of the Benguela upwelling system
NASA Astrophysics Data System (ADS)
Fawcett, A. L.; Pitcher, G. C.; Shillington, F. A.
2008-05-01
Nearshore currents of the southern Namaqua shelf were investigated using data from a mooring situated three and a half kilometres offshore of Lambert's Bay, downstream of the Cape Columbine upwelling cell, on the west coast of South Africa. This area is susceptible to harmful algal blooms (HABs) and wind-forced variations in currents and water column structure are critical in determining the development, transport and dissipation of blooms. Time series of local wind data, and current and temperature profile data are described for three periods, considered to be representative of the latter part of the upwelling season (27 January-22 February), winter conditions (5-29 May) and the early part of the upwelling season (10 November-12 December) in 2005. Differences observed in mean wind strength and direction between data sets are indicative of seasonal changes in synoptic meteorological conditions. These quasi-seasonal variations in wind forcing affect nearshore current flow, leading to mean northward flow in surface waters early in the upwelling season when equatorward, upwelling-favourable winds are persistent. Mean near-surface currents are southward during the latter part of the upwelling season, consistent with more prolonged periods of relaxation from equatorward winds, and under winter conditions when winds were predominantly poleward. Within these seasonal variations in mean near-surface current direction, two scales of current variability were evident within all data sets: strong inertial oscillations were driven by diurnal winds and introduced vertical shear into the water column enhancing mixing across the thermocline, while sub-inertial current variability was driven by north-south wind reversals at periods of 2-5 days. Sub-inertial currents were found to lag wind reversals by approximately 12 h, with a tendency for near-surface currents to flow poleward in the absence of wind forcing. Consistent with similar sites along the Californian and Iberian coasts, the headland at Cape Columbine is considered to influence currents and circulation patterns during periods of relaxation from upwelling-favourable winds, favouring the development of a nearshore poleward current, leading to poleward advection of warm water, the development of stratification, and the creation of potentially favourable conditions for HAB development.
Research on the winding losses based on finite element method for transformer
NASA Astrophysics Data System (ADS)
Li, Wenpeng; Lai, Wenqing; Ye, Ligang; Luo, Hanwu; Luo, Changjiang; Cui, Shigang; Wang, Yongqiang
2018-04-01
Transformer loss can cause the transformer to overheat. Under the action of high frequency current, the loss of transformer windings will be aggravated due to proximity effect and skin effect. In this paper, a three-dimensional model of high frequency transformer windings is established. Considering of the proximity effect and skin effect, the eddy current effects loss in the transformer windings are simulated based on finite element method. And the winding losses of the transformer windings are obtained under different arrangements. The influence of the winding layout on the winding losses is given. Finally, the trend of winding loss with current frequency, winding thickness and inter layer spacing is obtained through calculation. The winding loss initially decreases as the thickness of the winding increases, but when it reaches a certain level, this reduction becomes insignificant.
Behavior data of battery and battery pack SOC estimation under different working conditions.
Zhang, Xu; Wang, Yujie; Yang, Duo; Chen, Zonghai
2016-12-01
This article provides the dataset of operating conditions of battery behavior. The constant current condition and the dynamic stress test (DST) condition were carried out to analyze the battery discharging and charging features. The datasets were achieved at room temperature, in April, 2016. The shared data contributes to clarify the battery pack state-of-charge (SOC) and the battery inconsistency, which is also shown in the article of "An on-line estimation of battery pack parameters and state-of-charge using dual filters based on pack model" (X. Zhang, Y. Wang, D. Yang, et al., 2016) [1].
Owen, Whitney H.
1980-01-01
A polyphase rotary induction machine for use as a motor or generator utilizing a single rotor assembly having two series connected sets of rotor windings, a first stator winding disposed around the first rotor winding and means for controlling the current induced in one set of the rotor windings compared to the current induced in the other set of the rotor windings. The rotor windings may be wound rotor windings or squirrel cage windings.
Electrolytic dechlorination using a granular-graphite packed cathode is an alternative method for the remediation of chlorinated organic compounds. Its effectiveness under various conditions needs experimental investigation. Dechlorination of trichloroethylene (TCE) was conducted...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wei Qiao
2012-05-29
The penetration of wind power has increased greatly over the last decade in the United States and across the world. The U.S. wind power industry installed 1,118 MW of new capacity in the first quarter of 2011 alone and entered the second quarter with another 5,600 MW under construction. By 2030, wind energy is expected to provide 20% of the U.S. electricity needs. As the number of wind turbines continues to grow, the need for effective condition monitoring and fault detection (CMFD) systems becomes increasingly important [3]. Online CMFD is an effective means of not only improving the reliability, capacitymore » factor, and lifetime, but it also reduces the downtime, energy loss, and operation and maintenance (O&M) of wind turbines. The goal of this project is to develop novel online nonintrusive CMFD technologies for wind turbines. The proposed technologies use only the current measurements that have been used by the control and protection system of a wind turbine generator (WTG); no additional sensors or data acquisition devices are needed. Current signals are reliable and easily accessible from the ground without intruding on the wind turbine generators (WTGs) that are situated on high towers and installed in remote areas. Therefore, current-based CMFD techniques have great economic benefits and the potential to be adopted by the wind energy industry. Specifically, the following objectives and results have been achieved in this project: (1) Analyzed the effects of faults in a WTG on the generator currents of the WTG operating at variable rotating speed conditions from the perspective of amplitude and frequency modulations of the current measurements; (2) Developed effective amplitude and frequency demodulation methods for appropriate signal conditioning of the current measurements to improve the accuracy and reliability of wind turbine CMFD; (3) Developed a 1P-invariant power spectrum density (PSD) method for effective signature extraction of wind turbine faults with characteristic frequencies in the current or current demodulated signals, where 1P stands for the shaft rotating frequency of a WTG; (4) Developed a wavelet filter for effective signature extraction of wind turbine faults without characteristic frequencies in the current or current demodulated signals; (5) Developed an effective adaptive noise cancellation method as an alternative to the wavelet filter method for signature extraction of wind turbine faults without characteristic frequencies in the current or current demodulated signals; (6) Developed a statistical analysis-based impulse detection method for effective fault signature extraction and evaluation of WTGs based on the 1P-invariant PSD of the current or current demodulated signals; (7) Validated the proposed current-based wind turbine CMFD technologies through extensive computer simulations and experiments for small direct-drive WTGs without gearboxes; and (8) Showed, through extensive experiments for small direct-drive WTGs, that the performance of the proposed current-based wind turbine CMFD technologies is comparable to traditional vibration-based methods. The proposed technologies have been successfully applied for detection of major failures in blades, shafts, bearings, and generators of small direct-drive WTGs. The proposed technologies can be easily integrated into existing wind turbine control, protection, and monitoring systems and can be implemented remotely from the wind turbines being monitored. The proposed technologies provide an alternative to vibration-sensor-based CMFD. This will reduce the cost and hardware complexity of wind turbine CMFD systems. The proposed technologies can also be combined with vibration-sensor-based methods to improve the accuracy and reliability of wind turbine CMFD systems. When there are problems with sensors, the proposed technologies will ensure proper CMFD for the wind turbines, including their sensing systems. In conclusion, the proposed technologies offer an effective means to achieve condition-based smart maintenance for wind turbines and have a great potential to be adopted by the wind energy industry due to their almost no-cost, nonintrusive features. Although only validated for small direct-drive wind turbines without gearboxes, the proposed technologies are also applicable for CMFD of large-size wind turbines with and without gearboxes. However, additional investigations are recommended in order to apply the proposed technologies to those large-size wind turbines.« less
Weber, Rainer K.
2011-01-01
Nasal packs are indispensable in ENT practice. This study reviews current indications, effectiveness and risks of nasal packs and stents. In endoscopic surgery, nasal packs should always have smooth surfaces to minimize mucosal damage, improve wound healing and increase patient comfort. Functional endoscopic endonasal sinus surgery allows the use of modern nasal packs, since pressure is no longer required. So called hemostatic/resorbable materials are a first step in this direction. However, they may lead to adhesions and foreign body reactions in mucosal membranes. Simple occlusion is an effective method for creating a moist milieu for improved wound healing and avoiding dryness. Stenting of the frontal sinus is recommended if surgery fails to produce a wide, physiologically shaped drainage path that is sufficiently covered by intact tissue. PMID:22073095
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kesgin, Ibrahim; Hasse, Quentin; Ivanyushenkov, Yury
The use of second-generation high-temperature superconducting-coated conductors enables an enhancement of the performance of undulator magnets. However, preventing the motion of the wire and providing sufficient conduction cooling to the winding stacks have remained challenges. In this study, we have evaluated epoxy impregnation techniques to address these issues. Epoxy resin was prepared with different nanopowders and the effect on the performance of the undulator coil pack was investigated. All epoxy impregnated coils showed smaller n values and some degree of deterioration of the critical current I c. The I c degradation was most pronounced for epoxy mixed with high aspectmore » ratio multiwalled carbon nanotubes (MWCNTs). It has been found that the crack formation in the epoxy results in plastic deformation of the copper stabilizer layer, which causes the underlying ceramic REBCO superconducting layer to crack resulting in degradation of the superconducting tape performance. As a result, careful adjustment of epoxy thickness surrounding the superconductor and the powder ratio in the epoxy eliminate the performance degradation.« less
Wind-Driven Formation of Ice Bridges in Straits.
Rallabandi, Bhargav; Zheng, Zhong; Winton, Michael; Stone, Howard A
2017-03-24
Ice bridges are static structures composed of tightly packed sea ice that can form during the course of its flow through a narrow strait. Despite their important role in local ecology and climate, the formation and breakup of ice bridges is not well understood and has proved difficult to predict. Using long-wave approximations and a continuum description of sea ice dynamics, we develop a one-dimensional theory for the wind-driven formation of ice bridges in narrow straits, which is verified against direct numerical simulations. We show that for a given wind stress and minimum and maximum channel widths, a steady-state ice bridge can only form beyond a critical value of the thickness and the compactness of the ice field. The theory also makes quantitative predictions for ice fluxes, which are particularly useful to estimate the ice export associated with the breakup of ice bridges. We note that similar ideas are applicable to dense granular flows in confined geometries.
Kim, So Young; Sim, Songyong; Choi, Hyo Geun
2018-06-05
This study aimed to evaluate the relations of smoking with asthma and asthma-related symptoms, considering quantitative and temporal influences. The 820,710 Korean adults in the Korean Community Health Survey in 2009, 2010, 2011, and 2013 were included and classified as non-smoker, past smoker or current smoker. Total smoking years, total pack-years, and age at smoking onset were assessed. Information on wheezing, exercise wheezing, and aggravation of asthma in the past 12 months and asthma diagnosis history and current treatment was collected. Multiple logistic regression analysis with complex sampling was used. Current and former smokers showed significant positive relations with wheezing, exercise wheezing, asthma ever, current asthma, and asthma aggravation. Current smokers demonstrated higher adjusted odd ratios (AORs) for wheezing, exercise wheezing, and asthma aggravation than former smokers. Former smokers showed higher AORs than current smokers for current asthma treatment. Longer passive smoking was related to wheezing and exercise wheezing. Greater age at smoking onset and duration since cessation were negatively related to wheezing, exercise wheezing, and current asthma; total pack-years demonstrated proportional associations with these symptoms. Former, current, and passive smoking was positively correlated with wheezing and exercise wheezing. Total pack-years and early initiation were increasingly related to asthma.
Klinger, Robert C.; Few, Alexandra P.; Knox, Kathleen A.; Hatfield, Brian E.; Clark, Jonathan; German, David W.; Stephenson, Thomas R.
2015-01-01
The association analyses indicated the potential for overlap between pack stock and SNBS was minimal; only 1 percent of the potential meadow area in the SNBS herd home ranges overlapped that of pack stock meadows. There were no systematic differences in overall vegetation structure or composition, or in diversity, cover, or composition of forage species, that indicated pack stock were altering SNBS habitat or affecting their nutrition. Variation in plant species composition was influenced primarily by random differences among meadows and environmental gradients, and there was little evidence that pack stock use contributed in meaningful ways to this variation. The few differences among meadows with different levels of use by bighorn sheep and pack stock either were minor or were not in a direction consistent with negative effects of pack stock on SNBS. We conclude that the current plan for managing pack stock grazing has been successful in minimizing significant negative effects on Sierra Nevada bighorn sheep at Sequoia and Kings Canyon National Parks.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Matinyan, A. M., E-mail: al-drm@mail.ru; Peshkov, M. V.; Karpov, V. N.
2016-09-15
The design and current spectrum of a thyristor valve controlled shunt reactor (TCSR) with split valveside windings are described. The dependence of the amplitudes of higher-order harmonics of the power winding current on the TCSR operating regime are presented for this TCSR design.
Smaller Cigarette Pack as a Commitment to Smoke Less? Insights from Behavioral Economics
Marti, Joachim; Sindelar, Jody
2015-01-01
Cigarettes are commonly sold in packs of 20 units and therefore little is known about the potential impact of pack size on consumption. Using insights from behavioral economics, we suggest that cigarette packs smaller than the standard size may help some smokers cut back and/or quit, consistent with their long-term goals. Results from an online hypothetical purchase experiment conducted in a sample of US smokers reveal that over a third of smokers are willing to pay a price premium to purchase in smaller quantities. Further, a desire to quit smoking and high self-control is associated with preference for a smaller pack. While we provide some preliminary evidence that smaller packs may be beneficial to certain types of smokers, further research should be conducted to assess whether the smaller pack size should be considered in the arsenal of tobacco control policies to help current smokers quit (JEL: I18; I12; D12) PMID:26356844
Pack Density Limitations of Hybrid Parachutes
NASA Technical Reports Server (NTRS)
Zwicker, Matthew L.; Sinclair, Robert J.
2013-01-01
The development and testing of the Orion crew capsule parachute system has provided a unique opportunity to study dense parachute packing techniques and limits, in order to establish a new baseline for future programs. The density of parachute packs has a significant influence on vibration loads, retention system stresses, and parachute mortar performance. Material compositions and pack densities of existing designs for space capsule recovery were compared, using the pack density of the Apollo main parachutes as the current baseline. The composition of parachutes has changed since Apollo, incorporating new materials such as Kevlar , Vectran , Teflon and Spectra . These materials have different specific densities than Nylon, so the densities of hybrid parachute packs cannot be directly compared to Nylon parachutes for determination of feasibility or volume allocation. Six parachute packs were evaluated in terms of weighted average solid density in order to achieve a non-dimensional comparison of packing density. Means of mitigating damage due to packing pressure and mortar firing were examined in light of the Capsule Parachute Assembly System (CPAS) and Apollo experience. Parachute design improvements including incorporation of modern materials and manufacturing processes serves to make CPAS the new knowledge base on which future spacecraft parachute systems will be built.
Assessing Attentional Prioritization of Front-of-Pack Nutrition Labels using Change Detection
Becker, Mark W.; Sundar, Raghav Prashant; Bello, Nora; Alzahabi, Reem; Weatherspoon, Lorraine; Bix, Laura
2015-01-01
We used a change detection method to evaluate attentional prioritization of nutrition information that appears in the traditional “Nutrition Facts Panel” and in front-of-pack nutrition labels. Results provide compelling evidence that front-of-pack labels attract attention more readily than the Nutrition Facts Panel, even when participants are not specifically tasked with searching for nutrition information. Further, color-coding the relative nutritional value of key nutrients within the front-of-pack label resulted in increased attentional prioritization of nutrition information, but coding using facial icons did not significantly increase attention to the label. Finally, the general pattern of attentional prioritization across front-of-pack designs was consistent across a diverse sample of participants. Our results indicate that color-coded, front-of-pack nutrition labels increase attention to the nutrition information of packaged food, a finding that has implications for current policy discussions regarding labeling change. PMID:26851468
Earth Obsersation taken by the Expedition 11 crew
2005-07-07
ISS011-E-10221 (7 July 2005) --- At the time of this Expedition 11 digital still camera's image, Hurricane Dennis was churning northwestward through the Caribbean Sea between Jamaica and eastern Cuba packing winds of up to 115 miles per hour. Even though the hurricane had just attained Category 3 intensity, the eye had not yet cleared. This high-oblique, panoramic view, taken through a 28mm lens at 21:14:00 gmt, is looking southwest.
Modeling Sea Ice Trajectories for Oil Spill Tracking.
1981-06-01
is compared with sea ice motions observed during the AIDJEX main field experiment in the Beaufort Sea from April 1975 to February 1976. The average ...more recently grown on leads formed as the floes fracture and divide. The large-scale average thickness of the pack ice is roughly 3 m. As an...opposite extreme, during the summer when air temperatures rise above freezing, melting and offshore winds combine to form an approximately 300-km-wide swath
Immersion Suit Flotation Testing REACT Report
2016-08-01
wind-generated motion, we used a 75-pound, pyramid anchor , with 20 feet of 3/8 inch mooring chain. As with the ballasted mannequin, the team fully...everything, packed it and shipped it to JMTF Mobile where the team would reassemble the gear for in-water deployment. This included both 75-pound anchors ...first mooring on the ramp, put the tethered buoy in the water, then put the anchor over the side, allowing the chain to run free. Next, the team
NASA Astrophysics Data System (ADS)
Arora, Shashank; Kapoor, Ajay; Shen, Weixiang
2018-02-01
Parasitic load, which describes electrical energy consumed by battery thermal management system (TMS), is an important design criterion for battery packs. Passive TMSs using phase change materials (PCMs) are thus generating much interest. However, PCMs suffer from low thermal conductivities. Most current thermal conductivity enhancement techniques involve addition of foreign particles to PCMs. Adding foreign particles increases effective thermal conductivity of PCM-systems but at expense of their latent heat capacity. This paper presents an alternate approach for improving thermal performance of PCM-based TMSs. The introduced technique involves placing battery cells in a vertically inverted position within the battery-pack. It is demonstrated through experiments that inverted cell-layout facilitates build-up of convection current in the pack, which in turn minimises thermal variations within the PCM matrix by enabling PCM mass transfer between the top and the bottom regions of the battery pack. The proposed system is found capable of maintaining tight control over battery cell temperature even during abusive usage, defined as high-rate repetitive cycling with minimal rest periods. In addition, this novel TMS can recover waste heat from PCM-matrix through thermoelectric devices, thereby resulting in a negative parasitic load for TMS.
The effect of cigarette branding and plain packaging on female youth in the United Kingdom.
Hammond, David; Daniel, Samantha; White, Christine M
2013-02-01
Cigarette packaging is the most prominent form of tobacco marketing remaining in countries such as the United Kingdom. The current study examined perceptions of cigarette packaging among female youth and the potential impact of "plain" cigarette packaging regulations. A national sample of 947 16- to 19-year-old female subjects in the United Kingdom completed an online survey. Participants were randomized to view 10 cigarette packs designed according to one of four experimental conditions: fully branded female packs, the same packs without descriptor words, the same packs without brand imagery or descriptors ("plain" packs), and branded non-female brands. Participants rated packs on measures of appeal and health risk, positive smoker image, and completed a behavioral pack selection task. Plain packs were rated as the least appealing and worse tasting compared with all other conditions. Plain packs were also associated with fewer false beliefs about health risks compared with branded packs. Removing brand descriptors from packs significantly reduced measures of appeal and taste, particularly for brands with flavor descriptors, such as cherry and vanilla. Plain packs were significantly less likely to be associated with positive images, such as glamour, sophistication, and slimness. Most importantly, respondents were significantly less likely to accept a pack of cigarettes when offered only plain versus branded packs (p = .026). Marketing in the form of pack branding remains a potent tool for increasing the appeal of tobacco products to young women. The findings provide empirical support for plain cigarette packaging regulations in Australia to be implemented in 2012. Copyright © 2013 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.
[Promising technologies of packed red blood cells production and storage].
Maksimov, A G; Golota, A S; Krassiĭ, A B
2013-10-01
The current article is dedicated to promising technologies of packed red blood cells production and storage. The following new technical approaches are presented: (1) erythrocytes storage in strict anaerobic argon-hydrogen environment, (2) lyophilization of erythrocyte suspension by its atomization in nitrogen gas, (3) lyophilization of erythrocytes by directional freezing under the influence of radio frequency radiation, (4) automated pharming of antigen free packed red blood cells from progenitor cell directly at the battlefield.
Ice tracking techniques, implementation, performance, and applications
NASA Technical Reports Server (NTRS)
Rothrock, D. A.; Carsey, F. D.; Curlander, J. C.; Holt, B.; Kwok, R.; Weeks, W. F.
1992-01-01
Present techniques of ice tracking make use both of cross-correlation and of edge tracking, the former being more successful in heavy pack ice, the latter being critical for the broken ice of the pack margins. Algorithms must assume some constraints on the spatial variations of displacements to eliminate fliers, but must avoid introducing any errors into the spatial statistics of the measured displacement field. We draw our illustrations from the implementation of an automated tracking system for kinematic analyses of ERS-1 and JERS-1 SAR imagery at the University of Alaska - the Alaska SAR Facility's Geophysical Processor System. Analyses of the ice kinematic data that might have some general interest to analysts of cloud-derived wind fields are the spatial structure of the fields, and the evaluation and variability of average deformation and its invariants: divergence, vorticity and shear. Many problems in sea ice dynamics and mechanics can be addressed with the kinematic data from SAR.
Regional Wave Climates along Eastern Boundary Currents
NASA Astrophysics Data System (ADS)
Semedo, Alvaro; Soares, Pedro
2016-04-01
Two types of wind-generated gravity waves coexist at the ocean surface: wind sea and swell. Wind sea waves are waves under growing process. These young growing waves receive energy from the overlaying wind and are strongly coupled to the local wind field. Waves that propagate away from their generation area and no longer receive energy input from the local wind are called swell. Swell waves can travel long distances across entire ocean basins. A qualitative study of the ocean waves from a locally vs. remotely generation perspective is important, since the air sea interaction processes is strongly modulated by waves and vary accordingly to the prevalence of wind sea or swell waves in the area. A detailed climatology of wind sea and swell waves along eastern boundary currents (EBC; California Current, Canary Current, in the Northern Hemisphere, and Humboldt Current, Benguela Current, and Western Australia Current, in the Southern Hemisphere), based on the ECMWF (European Centre for Medium-Range Weather Forecasts) ERA-Interim reanalysis will be presented. The wind regime along EBC varies significantly from winter to summer. The high summer wind speeds along EBC generate higher locally generated wind sea waves, whereas lower winter wind speeds in these areas, along with stronger winter extratropical storms far away, lead to a predominance of swell waves there. In summer, the coast parallel winds also interact with coastal headlands, increasing the wind speed through a process called "expansion fan", which leads to an increase in the height of locally generated waves downwind of capes and points. Hence the spatial patterns of the wind sea or swell regional wave fields are shown to be different from the open ocean along EBC, due to coastal geometry and fetch dimensions. Swell waves will be shown to be considerably more prevalent and to carry more energy in winter along EBC, while in summer locally generated wind sea waves are either more comparable to swell waves or, particularly in the lee of headlands, or even more prevalent and more energized than swell. This study is part of the WRCP-JCOMM COWCLIP (Coordinated Ocean Wave Climate Project) effort.
Generation and Reduction of NOx on Air-Fed Ozonizers
NASA Astrophysics Data System (ADS)
Ehara, Yoshiyasu; Amemiya, Yusuke; Yamamoto, Toshiaki
A generation and reduction of NOx on air-fed ozonizers using a ferroelectric packed bed reactor have been experimentally investigated. The reactors packed with CaTiO3, SrTiO3 and BaTiO3 pellets are examined for ozone generation. An ac voltage is applied to the reactor to generate partial discharge. Ozone concentration and the different nitrogen oxides at downstream of the packed bed reactor were measured with UV absorption ozone monitor and a Fourier transform infrared spectroscope respectively. The dielectric constant of packed ferroelectric pellets influences the discharge characteristic, ozone and NOx generations are varied by the dielectric constant value. Focusing on a discharge pulse current and maximum discharge magnitude, the ferroelectric packed bed plasma reactors have been evaluated on nitrogen oxide and ozone generated concentrations.
Energy Optimization for a Weak Hybrid Power System of an Automobile Exhaust Thermoelectric Generator
NASA Astrophysics Data System (ADS)
Fang, Wei; Quan, Shuhai; Xie, Changjun; Tang, Xinfeng; Ran, Bin; Jiao, Yatian
2017-11-01
An integrated starter generator (ISG)-type hybrid electric vehicle (HEV) scheme is proposed based on the automobile exhaust thermoelectric generator (AETEG). An eddy current dynamometer is used to simulate the vehicle's dynamic cycle. A weak ISG hybrid bench test system is constructed to test the 48 V output from the power supply system, which is based on engine exhaust-based heat power generation. The thermoelectric power generation-based system must ultimately be tested when integrated into the ISG weak hybrid mixed power system. The test process is divided into two steps: comprehensive simulation and vehicle-based testing. The system's dynamic process is simulated for both conventional and thermoelectric powers, and the dynamic running process comprises four stages: starting, acceleration, cruising and braking. The quantity of fuel available and battery pack energy, which are used as target vehicle energy functions for comparison with conventional systems, are simplified into a single energy target function, and the battery pack's output current is used as the control variable in the thermoelectric hybrid energy optimization model. The system's optimal battery pack output current function is resolved when its dynamic operating process is considered as part of the hybrid thermoelectric power generation system. In the experiments, the system bench is tested using conventional power and hybrid thermoelectric power for the four dynamic operation stages. The optimal battery pack curve is calculated by functional analysis. In the vehicle, a power control unit is used to control the battery pack's output current and minimize energy consumption. Data analysis shows that the fuel economy of the hybrid power system under European Driving Cycle conditions is improved by 14.7% when compared with conventional systems.
Maynard, Olivia M; Leonards, Ute; Attwood, Angela S; Bauld, Linda; Hogarth, Lee; Munafò, Marcus R
2014-06-25
Previous research on the effects of plain packaging has largely relied on self-report measures. Here we describe the protocol of a randomized controlled trial investigating the effect of the plain packaging of cigarettes on smoking behavior in a real-world setting. In a parallel group randomization design, 128 daily cigarette smokers (50% male, 50% female) will attend an initial screening session and be assigned plain or branded packs of cigarettes to smoke for a full day. Plain packs will be those currently used in Australia where plain packaging has been introduced, while branded packs will be those currently used in the United Kingdom. Our primary study outcomes will be smoking behavior (self-reported number of cigarettes smoked and volume of smoke inhaled per cigarette as measured using a smoking topography device). Secondary outcomes measured pre- and post-intervention will be smoking urges, motivation to quit smoking, and perceived taste of the cigarettes. Secondary outcomes measured post-intervention only will be experience of smoking from the cigarette pack, overall experience of smoking, attributes of the cigarette pack, perceptions of the on-packet health warnings, behavior changes, views on plain packaging, and the rewarding value of smoking. Sex differences will be explored for all analyses. This study is novel in its approach to assessing the impact of plain packaging on actual smoking behavior. This research will help inform policymakers about the effectiveness of plain packaging as a tobacco control measure. Current Controlled Trials ISRCTN52982308 (registered 27 June 2013).
NASA Astrophysics Data System (ADS)
Li, XiaoMing; Chi, Lequan; Chen, Xueen; Ren, YongZheng; Lehner, Susanne
2014-08-01
A TerraSAR-X (TS-X) Synthetic Aperture Radar (SAR) image acquired at the East China Sea offshore wind farm presents distinct wakes at a kilometer scale on the lee of the wind turbines. The presumption was that these wakes were caused by wind movement around turbine blades. However, wind analysis using spaceborne radiometer data, numerical weather prediction, and in situ measurements suggest that the prevailing wind direction did not align with the wakes. By analyzing measurement at the tidal gauge station and modeling of the tidal current field, these trailing wakes are interpreted to have formed when a strong tidal current impinged on the cylindrical monopiles of the wind turbines. A numerical simulation was further conducted to reproduce the tidal current wake under such conditions. Comparison of the simulated surface velocity in the wake region with the TS-X sea surface backscatter intensity shows a similar trend. Consequently, turbulence intensity (T.I.) of the tidal current wakes over multiple piles is studied using the TS-X observation. It is found that the T.I. has a logarithmic relation with distance. Furthermore, another case study showing wakes due to wind movement around turbine blades is presented to discuss the differences in the tidal current wakes and wind turbine wakes. The conclusion is drawn that small-scale wakes formed by interaction of the tidal current and the turbine piles could be also imaged by SAR when certain conditions are satisfied. The study is anticipated to draw more attentions to the impacts of offshore wind foundations on local hydrodynamic field.
NASA Astrophysics Data System (ADS)
Zhang, Xu; Wang, Yujie; Liu, Chang; Chen, Zonghai
2018-02-01
An accurate battery pack state of health (SOH) estimation is important to characterize the dynamic responses of battery pack and ensure the battery work with safety and reliability. However, the different performances in battery discharge/charge characteristics and working conditions in battery pack make the battery pack SOH estimation difficult. In this paper, the battery pack SOH is defined as the change of battery pack maximum energy storage. It contains all the cells' information including battery capacity, the relationship between state of charge (SOC) and open circuit voltage (OCV), and battery inconsistency. To predict the battery pack SOH, the method of particle swarm optimization-genetic algorithm is applied in battery pack model parameters identification. Based on the results, a particle filter is employed in battery SOC and OCV estimation to avoid the noise influence occurring in battery terminal voltage measurement and current drift. Moreover, a recursive least square method is used to update cells' capacity. Finally, the proposed method is verified by the profiles of New European Driving Cycle and dynamic test profiles. The experimental results indicate that the proposed method can estimate the battery states with high accuracy for actual operation. In addition, the factors affecting the change of SOH is analyzed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Smith, Kandler
Battery Life estimation is one of the key inputs required for Hybrid applications for all GM Hybrid/EV/EREV/PHEV programs. For each Hybrid vehicle program, GM has instituted multi-parameter Design of Experiments generating test data at Cell level and also Pack level on a reduced basis. Based on experience, generating test data on a pack level is found to be very expensive, resource intensive and sometimes less reliable. The proposed collaborative project will focus on a methodology to estimate Battery life based on cell degradation data combined with pack thermal modeling. NREL has previously developed cell-level battery aging models and pack-level thermal/electricalmore » network models, though these models are currently not integrated. When coupled together, the models are expected to describe pack-level thermal and aging response of individual cells. GM and NREL will use data collected for GM's Bas+ battery system for evaluation of the proposed methodology and assess to what degree these models can replace pack-level aging experiments in the future.« less
Apparatus for measuring high frequency currents
NASA Technical Reports Server (NTRS)
Hagmann, Mark J. (Inventor); Sutton, John F. (Inventor)
2003-01-01
An apparatus for measuring high frequency currents includes a non-ferrous core current probe that is coupled to a wide-band transimpedance amplifier. The current probe has a secondary winding with a winding resistance that is substantially smaller than the reactance of the winding. The sensitivity of the current probe is substantially flat over a wide band of frequencies. The apparatus is particularly useful for measuring exposure of humans to radio frequency currents.
76 FR 40052 - Regulatory Agenda
Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-07
... Current Good Manufacturing 0910-AG10 Practice in Manufacturing, Processing, Packing or Holding Animal Food... in Manufacturing, Processing, Packing or Holding Animal Food Legal Authority: 21 U.S.C. 342; 21 U.S.C... constitute on farm manufacturing or processing of food that is not grown, raised, or consumed on a farm or...
NASA Astrophysics Data System (ADS)
Ganesan, Nandhini; Basu, Suman; Hariharan, Krishnan S.; Kolake, Subramanya Mayya; Song, Taewon; Yeo, Taejung; Sohn, Dong Kee; Doo, Seokgwang
2016-08-01
Lithium-Ion batteries used for electric vehicle applications are subject to large currents and various operation conditions, making battery pack design and life extension a challenging problem. With increase in complexity, modeling and simulation can lead to insights that ensure optimal performance and life extension. In this manuscript, an electrochemical-thermal (ECT) coupled model for a 6 series × 5 parallel pack is developed for Li ion cells with NCA/C electrodes and validated against experimental data. Contribution of the cathode to overall degradation at various operating conditions is assessed. Pack asymmetry is analyzed from a design and an operational perspective. Design based asymmetry leads to a new approach of obtaining the individual cell responses of the pack from an average ECT output. Operational asymmetry is demonstrated in terms of effects of thermal gradients on cycle life, and an efficient model predictive control technique is developed. Concept of reconfigurable battery pack is studied using detailed simulations that can be used for effective monitoring and extension of battery pack life.
Valve leakage inspection, testing, and maintenance process
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aikin, J.A.; Reinwald, J.W.
1989-01-01
Atomic Energy of Canada Limited-Research Company (AECL-RC), Chalk River, has more than 50 person-years dedicated toward the leak-free valve. In the early 1970s, the Chalk River Nuclear Laboratories (CRNL) developed valve stem live-loading and recently completed the packing tests for the Electric Power Research Institute (EPRI)-funded Valve Packing Improvement Study. Current safety concerns with asbestos-based valve packings and the difficulty in removing newer graphite packings prompted CRNL to investigate methods to improve valve repacking procedures. The present practice of valve packing replacement is very labor-intensive, requiring use of hand tools such as corkscrew devices and special packing picks. Use ofmore » water jets to cut or fragment the packing for withdrawal from the stuffing box does improve the process, but removal of the lantern or junk rings is still difficult. To address these problems, AECL-RC has developed a unique valve maintenance process designed to reduce person-rem exposures, the risk of scoring the stem or stuffing box, and maintenance costs and to improve the engineering quality of valve repair.« less
Environmental Variability during the CHURCH STROKE II Cruise 5 Exercise
1979-02-01
Route Z eNerth Stonington, CT 06359 ATTN: S. Elam 1 Arthur D. Little, inc. 15 Acorn Park ’ambridge, MA 02140 "ATTN. Dr, G. Roisbeck 1 W. G. Sykes 1 ...aircraft throughout these areas to coincide with acoustic events. (U) OCEANOGRAPHIC FINDINGS 1 . (U) Typhoon Lucy, a storm which packed sustained...winds of 120 mph, had only a minimal effect on the sound speed structure along the baseline as late as 2- 1 /2 days after its passage. The lack of observed
Transformer current sensor for superconducting magnetic coils
Shen, S.S.; Wilson, C.T.
1985-04-16
The present invention is a current transformer for operating currents larger than 2kA (two kiloamps) that is capable of detecting a millivolt level resistive voltage in the presence of a large inductive voltage. Specifically, the present invention includes substantially cylindrical primary turns arranged to carry a primary current and substantially cylindrical secondary turns arranged coaxially with and only partially within the primary turns, the secondary turns including an active winding and a dummy winding, the active and dummy windings being coaxial, longitudinally separated and arranged to mutually cancel voltages excited by commonly experienced magnetic fields, the active winding but not the dummy winding being arranged within the primary turns.
NASA Astrophysics Data System (ADS)
Bruserud, Kjersti; Haver, Sverre; Myrhaug, Dag
2018-06-01
Measured current speed data show that episodes of wind-generated inertial oscillations dominate the current conditions in parts of the northern North Sea. In order to acquire current data of sufficient duration for robust estimation of joint metocean design conditions, such as wind, waves, and currents, a simple model for episodes of wind-generated inertial oscillations is adapted for the northern North Sea. The model is validated with and compared against measured current data at one location in the northern North Sea and found to reproduce the measured maximum current speed in each episode with considerable accuracy. The comparison is further improved when a small general background current is added to the simulated maximum current speeds. Extreme values of measured and simulated current speed are estimated and found to compare well. To assess the robustness of the model and the sensitivity of current conditions from location to location, the validated model is applied at three other locations in the northern North Sea. In general, the simulated maximum current speeds are smaller than the measured, suggesting that wind-generated inertial oscillations are not as prominent at these locations and that other current conditions may be governing. Further analysis of the simulated current speed and joint distribution of wind, waves, and currents for design of offshore structures will be presented in a separate paper.
NASA Astrophysics Data System (ADS)
Bruserud, Kjersti; Haver, Sverre; Myrhaug, Dag
2018-04-01
Measured current speed data show that episodes of wind-generated inertial oscillations dominate the current conditions in parts of the northern North Sea. In order to acquire current data of sufficient duration for robust estimation of joint metocean design conditions, such as wind, waves, and currents, a simple model for episodes of wind-generated inertial oscillations is adapted for the northern North Sea. The model is validated with and compared against measured current data at one location in the northern North Sea and found to reproduce the measured maximum current speed in each episode with considerable accuracy. The comparison is further improved when a small general background current is added to the simulated maximum current speeds. Extreme values of measured and simulated current speed are estimated and found to compare well. To assess the robustness of the model and the sensitivity of current conditions from location to location, the validated model is applied at three other locations in the northern North Sea. In general, the simulated maximum current speeds are smaller than the measured, suggesting that wind-generated inertial oscillations are not as prominent at these locations and that other current conditions may be governing. Further analysis of the simulated current speed and joint distribution of wind, waves, and currents for design of offshore structures will be presented in a separate paper.
Gallopel-Morvan, Karine; Moodie, Crawford; Hammond, David; Eker, Figen; Beguinot, Emmanuelle; Martinet, Yves
2012-09-01
In the face of comprehensive bans on the marketing of tobacco products, packaging has become an increasingly important promotional tool for the tobacco industry. A ban on the use of branding on tobacco packaging, known as 'plain' packaging, has emerged as a promising regulatory strategy. The current study sought to examine perceptions of cigarette packaging among adults in France. Adult smokers and non-smokers (N=836) were surveyed using computer-assisted personal interviewing to assess perceptions of pack design by comparing 'regular' branded packs and 'limited edition' packs (with novel designs or innovations) with 'plain' versions of these packs with all branding, including colour, removed. Plain packs (PP) were less likely than regular packs, and particularly limited edition packs, to be considered attractive, attention grabbing and likely to motivate youth purchase. PPs were also rated as the most effective in convincing non-smokers not to start and smokers to reduce consumption and quit. Logistic regression showed that smokers motivated to quit, in comparison to smokers not motivated to quit, were significantly more likely to consider the PPs as the packs most likely to motivate cessation. Novel cigarette packaging, in the form of limited edition packs, had the highest ratings of consumer appeal, ahead of regular branded packs and also PPs. Interestingly, PPs were perceived to be the packs most likely to promote cessation among those adults with quitting intentions. Plain packaging, therefore, may be a means of helping existing adult smokers motivated to quit to do so.
ARE660 Wind Generator: Low Wind Speed Technology for Small Turbine Development
DOE Office of Scientific and Technical Information (OSTI.GOV)
Robert W. Preus; DOE Project Officer - Keith Bennett
2008-04-23
This project is for the design of a wind turbine that can generate most or all of the net energy required for homes and small businesses in moderately windy areas. The purpose is to expand the current market for residential wind generators by providing cost effective power in a lower wind regime than current technology has made available, as well as reduce noise and improve reliability and safety. Robert W. Preus’ experience designing and/or maintaining residential wind generators of many configurations helped identify the need for an improved experience of safety for the consumer. Current small wind products have unreliablemore » or no method of stopping the wind generator in fault or high wind conditions. Consumers and their neighbors do not want to hear their wind generators. In addition, with current technology, only sites with unusually high wind speeds provide payback times that are acceptable for the on-grid user. Abundant Renewable Energy’s (ARE) basic original concept for the ARE660 was a combination of a stall controlled variable speed small wind generator and automatic fail safe furling for shutdown. The stall control for a small wind generator is not novel, but has not been developed for a variable speed application with a permanent magnet alternator (PMA). The fail safe furling approach for shutdown has not been used to our knowledge.« less
A study on the consumer's perception of front-of-pack nutrition labeling
Kim, Woo Kyoung
2009-01-01
The goal of this research is to investigate the present situation for front of pack labeling in Korea and the perception of consumers for the new system of labeling, front of pack labeling, based on the consumer survey. We investigated the number of processed foods with front of pack labeling in one retailer in Youngin-si. And we also surveyed 1,019 participants nationwide whose ages were from 20 to 49; the knowledge of nutrition labeling, the knowledge of 'front of pack labeling', and the opinion about the labeling system. The data were analyzed using SAS statistics program. The results were as follows: 13.4% of processed foods had front of pack labeling, and 16.8% of the consumers always checked the nutrition labeling, while 32.7% of the consumers seldom checked it. In addition, 44.3% of the consumers think that 'front of pack labeling' is necessary, and 58.3% of the consumers think it is important to show the percentage of daily value as a way of 'front of pack labeling'. However, 32% of the consumer think the possibility of 'front of pack labeling' is slim. Meanwhile, 58.3% of the consumers think that it is important to have the color difference according to contents. The number of favorite nutrients in the front of pack was four or five. It seems that the recognition of current nutrition labeling has the influence on the willingness of using the future 'front of pack labeling'. Along with our study, the policy for 'front of pack labeling' has to be updated and improved constantly since 'front of pack labeling' helps consumer understand nutrition facts. PMID:20098583
Safety considerations for fabricating lithium battery packs
NASA Technical Reports Server (NTRS)
Ciesla, J. J.
1986-01-01
Lithium cell safety is a major issue with both manufacturers and end users. Most manufacturers have taken great strides to develop the safest cells possible while still maintaining performance characteristics. The combining of lithium cells for higher voltages, currents, and capacities requires the fabricator of lithium battery packs to be knowledgable about the specific electrochemical system being used. Relatively high rate, spirally wound (large surface area) sulfur oxychloride cells systems, such as Li/Thionyl or Sulfuryl chloride are considered. Prior to the start of a design of a battery pack, a review of the characterization studies for the cells should be conducted. The approach for fabricating a battery pack might vary with cell size.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zegrya, G. G.; Savenkov, G. G.; Morozov, V. A.
2017-04-15
The sensitivity of an energy-packed compound based on nanoporous silicon and calcium perchlorate to a high-current electron beam is studied. The initiation of explosive transformations in a mixture of potassium picrate with a highly dispersed powder of boron-doped silicon by means of a high-voltage discharge is examined. It is shown that explosive transformation modes (combustion and explosion) appear in the energy-packed compound under study upon its treatment with an electron beam. A relationship is established between the explosive transformation modes and the density of the energy-packed compound and between the breakdown (initiation) voltage and the mass fraction of the siliconmore » powder.« less
Sea Surface Wakes Observed by Spaceborne SAR in the Offshore Wind Farms
NASA Astrophysics Data System (ADS)
Li, Xiaoming; Lehner, Susanne; Jacobsen, Sven
2014-11-01
In the paper, we present some X-band spaceborne synthetic aperture radar (SAR) TerraSAR-X (TS-X) images acquired at the offshore wind farms in the North Sea and the East China Sea. The high spatial resolution SAR images show different sea surface wake patterns downstream of the offshore wind turbines. The analysis suggests that there are major two types of wakes among the observed cases. The wind turbine wakes generated by movement of wind around wind turbines are the most often observed cases. In contrast, due to the strong local tidal currents in the near shore wind farm sites, the tidal current wakes induced by tidal current impinging on the wind turbine piles are also observed in the high spatial resolution TS-X images. The discrimination of the two types of wakes observed in the offshore wind farms is also described in the paper.
NASA Astrophysics Data System (ADS)
Dottori, Marcelo; Castro, Belmiro Mendes
2018-06-01
Data analysis of continental shelf currents and coastal sea level, together with the application of a semi-analytical model, are used to estimate the importance of remote wind forcing on the subinertial variability of the current in the central and northern areas of the South Brazil Bight. Results from both the data analysis and from the semi-analytical model are robust in showing subinertial variability that propagates along-shelf leaving the coast to the left in accordance with theoretical studies of Continental Shelf Waves (CSW). Both the subinertial variability observed in along-shelf currents and sea level oscillations present different propagation speeds for the narrow northern part of the SBB ( 6-7 m/s) and the wide central SBB region ( 11 m/s), those estimates being in agreement with the modeled CSW propagation speed. On the inner and middle shelf, observed along-shelf subinertial currents show higher correlation coefficients with the winds located southward and earlier in time than with the local wind at the current meter mooring position and at the time of measurement. The inclusion of the remote (located southwestward) wind forcing improves the prediction of the subinertial currents when compared to the currents forced only by the local wind, since the along-shelf-modeled currents present correlation coefficients with observed along-shelf currents up to 20% higher on the inner and middle shelf when the remote wind is included. For most of the outer shelf, on the other hand, this is not observed since usually, the correlation between the currents and the synoptic winds is not statistically significant.
NASA Astrophysics Data System (ADS)
Dottori, Marcelo; Castro, Belmiro Mendes
2018-05-01
Data analysis of continental shelf currents and coastal sea level, together with the application of a semi-analytical model, are used to estimate the importance of remote wind forcing on the subinertial variability of the current in the central and northern areas of the South Brazil Bight. Results from both the data analysis and from the semi-analytical model are robust in showing subinertial variability that propagates along-shelf leaving the coast to the left in accordance with theoretical studies of Continental Shelf Waves (CSW). Both the subinertial variability observed in along-shelf currents and sea level oscillations present different propagation speeds for the narrow northern part of the SBB ( 6-7 m/s) and the wide central SBB region ( 11 m/s), those estimates being in agreement with the modeled CSW propagation speed. On the inner and middle shelf, observed along-shelf subinertial currents show higher correlation coefficients with the winds located southward and earlier in time than with the local wind at the current meter mooring position and at the time of measurement. The inclusion of the remote (located southwestward) wind forcing improves the prediction of the subinertial currents when compared to the currents forced only by the local wind, since the along-shelf-modeled currents present correlation coefficients with observed along-shelf currents up to 20% higher on the inner and middle shelf when the remote wind is included. For most of the outer shelf, on the other hand, this is not observed since usually, the correlation between the currents and the synoptic winds is not statistically significant.
Does every US smoker bear the same cigarette tax?
Xu, Xin; Malarcher, Ann; O’Halloran, Alissa; Kruger, Judy
2015-01-01
Aims To evaluate state cigarette excise tax pass-through rates for selected price-minimizing strategies. Design Multivariate regression analysis of current smokers from a stratified, national, dual-frame telephone survey. Setting United States. Participants A total of 16 542 adult current smokers aged 18 years or older. Measurements Cigarette per pack prices paid with and without coupons were obtained for pack versus carton purchase, use of generic brands versus premium brands, and purchase from Indian reservations versus outside Indian reservations. Findings The average per pack prices paid differed substantially by price-minimizing strategy. Smokers who used any type of price-minimizing strategies paid substantially less than those who did not use these strategies (P < 0.05). Premium brand users who purchased by pack in places outside Indian reservations paid the entire amount of the excise tax, together with an additional premium of 7–10 cents per pack for every $1 increase in excise tax (pass-through rate of 1.07–1.10, P < 0.05). In contrast, carton purchasers, generic brand users or those who were likely to make their purchases on Indian reservations paid only 30–83 cents per pack for every $1 tax increase (pass-through rate of 0.30–0.83, P < 0.05). Conclusions Many smokers in the United States are able to avoid the full impact of state excise tax on cost of smoking by buying cartons, using generic brands and buying from Indian reservations. PMID:24861973
Controlling Blown Pack Spoilage Using Anti-Microbial Packaging
Reid, Rachael; Tyuftin, Andrey A.; Kerry, Joe P.; Whyte, Paul; Bolton, Declan
2017-01-01
Active (anti-microbial) packaging was prepared using three different formulations; Auranta FV; Inbac-MDA and sodium octanoate at two concentrations (2.5 and 3.5 times their minimum inhibitory concentration (MIC, the lowest concentration that will inhibit the visible growth of the organisms) against Clostridium estertheticum, DSMZ 8809). Inoculated beef samples were packaged using the active packaging and monitored for 100 days storage at 2 °C for blown pack spoilage. The time to the onset of blown pack spoilage was significantly (p < 0.01) increased using Auranta FV and sodium octanoate (caprylic acid sodium salt) at both concentrations. Moreover, sodium octanoate packs had significantly (p < 0.01) delayed blown pack spoilage as compared to Auranta FV. It was therefore concluded that Auranta FV or sodium octanoate, incorporated into the packaging materials used for vacuum packaged beef, would inhibit blown pack spoilage and in the case of the latter, well beyond the 42 days storage period currently required for beef primals. PMID:28805679
Controlling Blown Pack Spoilage Using Anti-Microbial Packaging.
Reid, Rachael; Bolton, Declan; Tiuftin, Andrey A; Kerry, Joe P; Fanning, Séamus; Whyte, Paul
2017-08-12
Active (anti-microbial) packaging was prepared using three different formulations; Auranta FV; Inbac-MDA and sodium octanoate at two concentrations (2.5 and 3.5 times their minimum inhibitory concentration (MIC, the lowest concentration that will inhibit the visible growth of the organisms) against Clostridium estertheticum , DSMZ 8809). Inoculated beef samples were packaged using the active packaging and monitored for 100 days storage at 2 °C for blown pack spoilage. The time to the onset of blown pack spoilage was significantly ( p < 0.01) increased using Auranta FV and sodium octanoate (caprylic acid sodium salt) at both concentrations. Moreover, sodium octanoate packs had significantly ( p < 0.01) delayed blown pack spoilage as compared to Auranta FV. It was therefore concluded that Auranta FV or sodium octanoate, incorporated into the packaging materials used for vacuum packaged beef, would inhibit blown pack spoilage and in the case of the latter, well beyond the 42 days storage period currently required for beef primals.
Rapidly falling costs of battery packs for electric vehicles
NASA Astrophysics Data System (ADS)
Nykvist, Björn; Nilsson, Måns
2015-04-01
To properly evaluate the prospects for commercially competitive battery electric vehicles (BEV) one must have accurate information on current and predicted cost of battery packs. The literature reveals that costs are coming down, but with large uncertainties on past, current and future costs of the dominating Li-ion technology. This paper presents an original systematic review, analysing over 80 different estimates reported 2007-2014 to systematically trace the costs of Li-ion battery packs for BEV manufacturers. We show that industry-wide cost estimates declined by approximately 14% annually between 2007 and 2014, from above US$1,000 per kWh to around US$410 per kWh, and that the cost of battery packs used by market-leading BEV manufacturers are even lower, at US$300 per kWh, and has declined by 8% annually. Learning rate, the cost reduction following a cumulative doubling of production, is found to be between 6 and 9%, in line with earlier studies on vehicle battery technology. We reveal that the costs of Li-ion battery packs continue to decline and that the costs among market leaders are much lower than previously reported. This has significant implications for the assumptions used when modelling future energy and transport systems and permits an optimistic outlook for BEVs contributing to low-carbon transport.
The neutral wind 'flywheel' as a source of quiet-time, polar-cap currents
NASA Technical Reports Server (NTRS)
Lyons, L. R.; Walterscheid, R. L.; Killeen, T. L.
1985-01-01
The neutral wind pattern over the summer polar cap can be driven by plasma convection to resemble the convection pattern. For a north-south component of the interplanetary magnetic field Bz directed southward, the wind speeds in the conducting E-region can become approximately 25 percent of the electric field drift speeds. If convection ceases, this neutral wind distribution can drive a significant polar cap current system for approximately 6 hours. The currents are reversed from those driven by the electric fields for southward Bz, and the Hall and field-aligned components of the current system resemble those observed during periods of northward Bz. The current magnitudes are similar to those observed during periods of small, northward Bz; however, observations indicate that electric fields often contribute to the currents as much as, or more than, the neutral winds.
Modeling of the coupled magnetospheric and neutral wind dynamos
NASA Technical Reports Server (NTRS)
Thayer, Jeffrey P.
1994-01-01
This report summarizes the progress made in the first year of NASA Grant No. NAGW-3508 entitled 'Modeling of the Coupled Magnetospheric and Neutral Wind Dynamos.' The approach taken has been to impose magnetospheric boundary conditions with either pure voltage or current characteristics and solve the neutral wind dynamo equation under these conditions. The imposed boundary conditions determine whether the neutral wind dynamo will contribute to the high-latitude current system or the electric potential. The semi-annual technical report, dated December 15, 1993, provides further detail describing the scientific and numerical approach of the project. The numerical development has progressed and the dynamo solution for the case when the magnetosphere acts as a voltage source has been evaluated completely using spectral techniques. The simulation provides the field-aligned current distribution at high latitudes due to the neutral wind dynamo. A number of geophysical conditions can be simulated to evaluate the importance of the neutral wind dynamo contribution to the field-aligned current system. On average, field-aligned currents generated by the neutral wind dynamo contributed as much as 30 percent to the large-scale field-aligned current system driven by the magnetosphere. A term analysis of the high-latitude neutral wind dynamo equation describing the field aligned current distribution has also been developed to illustrate the important contributing factors involved in the process. The case describing the neutral dynamo response for a magnetosphere acting as a pure current generator requires the existing spectral code to be extended to a pseudo-spectral method and is currently under development.
Typhoon Neoguri in the East China Sea
2017-12-08
The MODIS instrument on NASA's Aqua satellite captured Typhoon Neoguri in the East China Sea at 05:00 UTC (1:00 AM EDT) on July 8, 2014. Typhoon Neoguri hit Japan’s Okinawa islands on Tuesday local time (July 8, 2014), bringing high winds, huge waves and storm surges. Neoguri packed sustained winds of 175 kilometers (108 miles) per hour with some gusts up to 250 kph (154 mph), according to the Japan Meteorological Agency. Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram
NASA Astrophysics Data System (ADS)
Oerder, V.; Colas, F.; Echevin, V.; Masson, S.; Lemarié, F.
2018-02-01
The ocean dynamical responses to the surface current-wind stress interaction at the oceanic mesoscale are investigated in the South-East Pacific using a high-resolution regional ocean-atmosphere coupled model. Two simulations are compared: one includes the surface current in the wind stress computation while the other does not. In the coastal region, absolute wind velocities are different between the two simulations but the wind stress remains very similar. As a consequence, the mean regional oceanic circulation is almost unchanged. On the contrary, the mesoscale activity is strongly reduced when taking into account the effect of the surface current on the wind stress. This is caused by a weakening of the eddy kinetic energy generation near the coast by the wind work and to intensified offshore eddy damping. We show that, above coherent eddies, the current-stress interaction generates eddy damping through Ekman pumping and eddy kinetic energy dissipation through wind work. This alters significantly the coherent eddy vertical structures compared with the control simulation, weakening the temperature and vorticity anomalies and increasing strongly the vertical velocity anomalies associated to eddies.
The influence of winding direction of two-layer HTS DC cable on the critical current
NASA Astrophysics Data System (ADS)
Vyatkin, V. S.; Kashiwagi, K.; Ivanov, Y. V.; Otabe, E. S.; Yamaguchi, S.
2017-09-01
The design of twist pitch and direction of winding in multilayer HTS coaxial cable is important. For HTS AC transmitting cables, the main condition of twist pitch is the balance of inductances of each layer for providing the current balance between layers. In this work, the finite element method analysis for the coaxial cables with both same and opposite directions winding is used to calculate magnetic field distribution, and critical current of the cable is estimated. It was found that the critical current of the cable with same direction winding is about 10 percent higher than that in the case of the cable with the opposite direction winding.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kim, Eungsoo; Manuel, Lance; Curcic, Milan
In the United States, potential offshore wind plant sites have been identified along the Atlantic seaboard and in the Gulf of Mexico. It is imperative that we define external conditions associated with hurricanes and severe winter storms and consider load cases for which wind turbines may need to be designed. We selected two hurricanes, Ike (2008) and Sandy (2012), and investigated the effect these tropical storms would have on bottom-supported offshore wind turbines that were hypothetically in or close to their path as they made landfall. For realistic turbine loads assessment, it is important that the coupled influences of themore » changing wind, wave, and current fields are simulated throughout the evolution of the hurricanes. We employed a coupled model--specifically, the University of Miami Coupled Model (UMCM)--that integrates atmospheric, wave, and ocean components to produce needed wind, wave, and current data. The wind data are used to generate appropriate vertical wind profiles and full wind velocity fields including turbulence; the current field over the water column is obtained by interpolated discrete output current data; and short-crested irregular second-order waves are simulated using output directional wave spectra from the coupled model. We studied two monopile-supported offshore wind turbines sited in 20 meters of water in the Gulf of Mexico to estimate loads during Hurricane Ike, and a jacket space-frame platform-supported offshore wind turbine sited in 50 meters of water in the mid-Atlantic region to estimate loads during Hurricane Sandy. In this report we discuss in detail how the simulated hurricane wind, wave, and current output data are used in turbine loads studies. In addition, important characteristics of the external conditions are studied, including the relative importance of swell versus wind seas, aerodynamic versus hydrodynamic forces, current velocity effects, yaw control options for the turbine, hydrodynamic drag versus inertia forces, and soil-structure interaction effects. A detailed framework is presented that explains how coupled inputs can be included in turbine loads studies during a hurricane. This framework can aid in future efforts aimed at developing offshore wind turbine design criteria and load cases related to hurricanes.« less
Federal Register 2010, 2011, 2012, 2013, 2014
2013-03-20
... Manufacturing Practice and Hazard Analysis and Risk- Based Preventive Controls for Human Food; Correction AGENCY... manufacturing, packing, or holding human food (CGMPs) to modernize it and to add requirements for domestic and... ``food-production purposes (i.e., manufacturing, processing, packing, and holding) to consistently use...
Compliance with Uruguay’s single presentation requirement
DeAtley, Teresa; Bianco, Eduardo; Welding, Kevin; Cohen, Joanna E
2018-01-01
Introduction Tobacco companies vary pack colours, designs, descriptors, flavours and brand names on cigarette packs to target a multitude of consumers. These different brand variants can falsely imply that some brand variants are less harmful than others. Uruguay is the only country that requires cigarette companies to adhere to a single presentation (one brand variant) per brand family. Methods An existing, systematic pack purchasing protocol was adapted for data collection. Neighbourhoods in Montevideo were categorised into five strata by percentage of poor households. Five neighbourhoods within each stratum were selected based on geographical variation. In each neighbourhood, a ‘starting hub’ was identified and a systematic walking protocol was implemented to purchase unique packs at four key vendor types. Results Unique packs were purchased in 9 out of 25 neighbourhoods. Fifty-six unique packs were purchased, representing 30 brands. Of these, 51 packs were legal, representing 26 brands. The majority of the legal brands (n=16; 62%) were compliant with the requirement. The remaining packs were non-compliant due to differences in colour, design element, brand name, crest and descriptors. Although not prohibited by the single presentation requirement, 16 legal brands had more than one stick count (10, 11, 14 or 20 sticks), and packs from four brands had more than one packaging type (hard, soft or tin). Conclusion Overall, compliance with Uruguay’s single presentation requirement was good. In addition to the current restrictions, future single presentation requirements could expand to include packs in more than one stick count and packaging type. PMID:28416710
Atmospheric signature of the Agulhas current
NASA Astrophysics Data System (ADS)
Stela Nkwinkwa Njouodo, Arielle; Koseki, Shunya; Rouault, Mathieu; Keenlyside, Noel
2017-04-01
Satellite observation and Climate Forecast System Reanalysis (CFSR) are used to map the influence of the Agulhas current on local annual precipitation in Southern Africa. The pressure adjustment mechanism is applied over the Agulhas current region. Results unfold that the narrow band of precipitation above the Agulhas Current is collocated with surface wind convergence, sea surface temperature (SST) Laplacian and sea level pressure (SLP) Laplacian. Relationship between SLP Laplacian and wind convergence is found, with 0.54 correlation coefficient statistically significant. In the free troposphere, the band of precipitation above the Agulhas current is collocated with the wind divergence and the upward motion of wind velocity. The warm waters from the Agulhas current can influence local precipitation.
Characteristics of illegal and legal cigarette packs sold in Guatemala.
Arevalo, Rodrigo; Corral, Juan E; Monzon, Diego; Yoon, Mira; Barnoya, Joaquin
2016-11-25
Guatemala, as a party to the Framework Convention on Tobacco Control (FCTC), is required to regulate cigarette packaging and labeling and eliminate illicit tobacco trade. Current packaging and labeling characteristics (of legal and illegal cigarettes) and their compliance with the FCTC is unknown. We sought to analyze package and label characteristics of illegal and legal cigarettes sold in Guatemala. We visited the 22 largest traditional markets in the country to purchase illegal cigarettes. All brands registered on tobacco industry websites were purchased as legal cigarettes. Analysis compared labeling characteristics of illegal and legal packs. Most (95%) markets and street vendors sold illegal cigarettes; 104 packs were purchased (79 illegal and 25 legal). Ten percent of illegal and none of the legal packs had misleading terms. Half of the illegal packs had a warning label covering 26 to 50% of the pack surface. All legal packs had a label covering 25% of the surface. Illegal packs were more likely to have information on constituents and emissions (85% vs. 45%, p < 0.001) and were less expensive than legal ones (USD 0.70 ± 0.7 and 1.9 ± 1.8, p < 0.001). In Guatemala, neither illegal nor legal cigarette packs comply with FCTC labeling mandates. Urgent implementation and enforcement of the FCTC is necessary to halt the tobacco epidemic.
NASA Astrophysics Data System (ADS)
Yamazaki, Y.
2015-12-01
The relationship between ionospheric dynamo currents and neutral winds is examined using the Thermosphere Ionosphere Mesosphere Electrodynamic General Circulation Model (TIME-GCM). The simulation is run for May and June 2009 with variable neutral winds but with constant solar and magnetospheric energy inputs, which ensures that day-to-day changes in the solar quiet (Sq) current system arise only from lower atmospheric forcing. The intensity and focus position of the simulated Sq current system exhibit large day-to-day variability, as is also seen in ground magnetometer data. We show how the day-to-day variation of the Sq current system relate to variable winds at various altitudes, latitudes, and longitudes.
Wind influence on a coastal buoyant outflow
NASA Astrophysics Data System (ADS)
Whitney, Michael M.; Garvine, Richard W.
2005-03-01
This paper investigates the interplay between river discharge and winds in forcing coastal buoyant outflows. During light winds a plume influenced by the Earth's rotation will flow down shelf (in the direction of Kelvin wave propagation) as a slender buoyancy-driven coastal current. Downwelling favorable winds augment this down-shelf flow, narrow the plume, and mix the water column. Upwelling favorable winds drive currents that counter the buoyancy-driven flow, spread plume waters offshore, and rapidly mix buoyant waters. Two criteria are developed to assess the wind influence on a buoyant outflow. The wind strength index (Ws) determines whether a plume's along-shelf flow is in a wind-driven or buoyancy-driven state. Ws is the ratio of the wind-driven and buoyancy-driven along-shelf velocities. Wind influence on across-shelf plume structure is rated with a timescale (ttilt) for the isopycnal tilting caused by wind-driven Ekman circulation. These criteria are used to characterize wind influence on the Delaware Coastal Current and can be applied to other coastal buoyant outflows. The Delaware buoyant outflow is simulated for springtime high-river discharge conditions. Simulation results and Ws values reveal that the coastal current is buoyancy-driven most of the time (∣Ws∣ < 1 on average). Wind events, however, overwhelm the buoyancy-driven flow (∣Ws∣ > 1) several times during the high-discharge period. Strong upwelling events reverse the buoyant outflow; they constitute an important mechanism for transporting fresh water up shelf. Across-shelf plume structure is more sensitive to wind influence than the along-shelf flow. Values of ttilt indicate that moderate or strong winds persisting throughout a day can modify plume width significantly. Plume widening during upwelling events is accompanied by mixing that can erase the buoyant outflow.
NASA Astrophysics Data System (ADS)
Gough, M.; Reniers, A.; MacMahan, J. H.; Howden, S. D.
2014-12-01
The continental shelf along the northeastern Gulf of Mexico is transected by the critical latitude (30°N) for inertial motions. At this latitude the inertial period is 24 hours and diurnal surface current oscillations can amplify due to resonance with diurnal wind and tidal forcing. Tidal amplitudes are relatively small in this region although K1 tidal currents can be strong over the shelf west of the DeSoto Canyon where the K1 tide propagates onshore as a Sverdrup wave. Other sources of diurnal motions include internal tidal currents, Poincaré waves, and basin resonance. It is therefore very difficult to separate inertial wind-driven motions from other diurnal motions. Spatiotemporal surface currents were measured using hourly 6 km resolution HF radar data collected in June 2010 during the Deepwater Horizon oil spill and July 2012 during the Grand Lagrangian Deployment (GLAD). Surface currents were also measured using GLAD GPS-tracked drifters. NDBC buoy wind data were used to determine wind-forcing, and OSU Tidal Inversion Software (OTIS) were used to predict tidal currents. The relative spatiotemporal influence of diurnal wind and tidal forcing on diurnal surface current oscillations is determined through a series of comparative analyses: phase and amplitude of bandpassed timeseries, wavelet analyses, wind-driven inertial oscillation calculations, and tidal current predictions. The wind-driven inertial ocean response is calculated by applying a simple "slab" model where wind-forcing is allowed to excite a layer of low-density water riding over high density water. The spatial variance of diurnal motions are found to be correlated with satellite turbidity imagery indicating that stratification influences the sea surface inertial response to wind-forcing. Surface dispersion is found to be minimized in regions of high diurnal variance suggesting that mean surface transport is restricted in regions of inertial motions associated with stratification.
NASA Astrophysics Data System (ADS)
Graham, R. M.; Itkin, P.; Granskog, M. A.; Assmy, P.; Cohen, L.; Duarte, P.; Doble, M. J.; Fransson, A.; Fer, I.; Fernandez Mendez, M.; Frey, M. M.; Gerland, S.; Haapala, J. J.; Hudson, S. R.; Liston, G. E.; Merkouriadi, I.; Meyer, A.; Muilwijk, M.; Peterson, A.; Provost, C.; Randelhoff, A.; Rösel, A.; Spreen, G.; Steen, H.; Smedsrud, L. H.; Sundfjord, A.
2017-12-01
To study the thinner and younger sea ice that now dominates the Arctic the Norwegian Young Sea ICE expedition (N-ICE2015) was launched in the ice-covered region north of Svalbard, from January to June 2015. During this time, eight local and remote storms affected the region and rare direct observations of the atmosphere, snow, ice and ocean were conducted. Six of these winter storms passed directly over the expedition and resulted in air temperatures rising from below -30oC to near 0oC, followed by abrupt cooling. Substantial snowfall prior to the campaign had already formed a snow pack of approximately 50 cm, to which the February storms contributed an additional 6 cm. The deep snow layer effectively isolated the ice cover and prevented bottom ice growth resulting in low brine fluxes. Peak wind speeds during winter storms exceeded 20 m/s, causing strong snow re-distribution, release of sea salt aerosol and sea ice deformation. The heavy snow load caused widespread negative freeboard; during sea ice deformation events, level ice floes were flooded by sea water, and at least 6-10 cm snow-ice layer was formed. Elevated deformation rates during the most powerful winter storms damaged the ice cover permanently such that the response to wind forcing increased by 60 %. As a result of a remote storm in April deformation processes opened about 4 % of the total area into leads with open water, while a similar amount of ice was deformed into pressure ridges. The strong winds also enhanced ocean mixing and increased ocean heat fluxes three-fold in the pycnocline from 4 to 12 W/m2. Ocean heat fluxes were extremely large (over 300 W/m2) during storms in regions where the warm Atlantic inflow is located close to surface over shallow topography. This resulted in very large (5-25 cm/day) bottom ice melt and in cases flooding due to heavy snow load. Storm events increased the carbon dioxide exchange between the atmosphere and ocean but also affected the pCO2 in surface waters through mixing. Finally, the combination of a higher lead fraction and thinner ice cover, driven in part by storms, helped facilitate an early under-ice phytoplankton bloom in May, far inside the ice pack. In summary the storms entail significant effects on the ice pack that may last much longer than the short-lived storm events.
The vertical structure of the circulation and dynamics in Hudson Shelf Valley
Lentz, Steven J.; Butman, Bradford; Harris, Courtney K.
2014-01-01
Hudson Shelf Valley is a 20–30 m deep, 5–10 km wide v-shaped submarine valley that extends across the Middle Atlantic Bight continental shelf. The valley provides a conduit for cross-shelf exchange via along-valley currents of 0.5 m s−1 or more. Current profile, pressure, and density observations collected during the winter of 1999–2000 are used to examine the vertical structure and dynamics of the flow. Near-bottom along-valley currents having times scales of a few days are driven by cross-shelf pressure gradients setup by wind stresses, with eastward (westward) winds driving onshore (offshore) flow within the valley. The along-valley momentum balance in the bottom boundary layer is predominantly between the pressure gradient and bottom stress because the valley bathymetry limits current veering. Above the bottom boundary layer, the flow veers toward an along-shelf (cross-valley) orientation and a geostrophic balance with some contribution from the wind stress (surface Ekman layer). The vertical structure and strength of the along-valley current depends on the magnitude and direction of the wind stress. During offshore flows driven by westward winds, the near-bottom stratification within the valley increases resulting in a thinner bottom boundary layer and weaker offshore currents. Conversely, during onshore flows driven by eastward winds the near-bottom stratification decreases resulting in a thicker bottom boundary layer and stronger onshore currents. Consequently, for wind stress magnitudes exceeding 0.1 N m−2, onshore along-valley transport associated with eastward wind stress exceeds the offshore transport associated with westward wind stress of the same magnitude.
Engineering innovation to reduce wind power COE
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ammerman, Curtt Nelson
There are enough wind resources in the US to provide 10 times the electric power we currently use, however wind power only accounts for 2% of our total electricity production. One of the main limitations to wind use is cost. Wind power currently costs 5-to-8 cents per kilowatt-hour, which is more than twice the cost of electricity generated by burning coal. Our Intelligent Wind Turbine LDRD Project is applying LANL's leading-edge engineering expertise in modeling and simulation, experimental validation, and advanced sensing technologies to challenges faced in the design and operation of modern wind turbines.
Does every US smoker bear the same cigarette tax?
Xu, Xin; Malarcher, Ann; O'Halloran, Alissa; Kruger, Judy
2014-10-01
To evaluate state cigarette excise tax pass-through rates for selected price-minimizing strategies. Multivariate regression analysis of current smokers from a stratified, national, dual-frame telephone survey. United States. A total of 16 542 adult current smokers aged 18 years or older. Cigarette per pack prices paid with and without coupons were obtained for pack versus carton purchase, use of generic brands versus premium brands, and purchase from Indian reservations versus outside Indian reservations. The average per pack prices paid differed substantially by price-minimizing strategy. Smokers who used any type of price-minimizing strategies paid substantially less than those who did not use these strategies (P < 0.05). Premium brand users who purchased by pack in places outside Indian reservations paid the entire amount of the excise tax, together with an additional premium of 7-10 cents per pack for every $1 increase in excise tax (pass-through rate of 1.07-1.10, P < 0.05). In contrast, carton purchasers, generic brand users or those who were likely to make their purchases on Indian reservations paid only 30-83 cents per pack for every $1 tax increase (pass-through rate of 0.30-0.83, P < 0.05). Many smokers in the United States are able to avoid the full impact of state excise tax on cost of smoking by buying cartons, using generic brands and buying from Indian reservations. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
Baseline Characteristics of Participants in the Randomized National Lung Screening Trial
Aberle, Denise R.; Adams, Amanda M.; Berg, Christine D.; Clapp, Jonathan D.; Clingan, Kathy L.; Gareen, Ilana F.; Marcus, Pamela M.; Pinsky, Paul F.
2010-01-01
Background The National Lung Screening Trial (NLST), a randomized study conducted at 33 US sites, is comparing lung cancer mortality among persons screened with reduced dose helical computerized tomography and among persons screened with chest radiograph. In this article, we present characteristics of the study population. Methods Eligible participants were aged 55–74 years and were current or former smokers with a cigarette smoking history of at least 30 pack-years. Randomization was stratified by site, sex, and age. To assess representativeness of the study population, demographic characteristics of individuals from the general population who met NLST age and smoking history inclusion criteria were obtained from the Tobacco Use Supplement of the US Census Bureau Current Population Surveys. Results The NLST enrolled 53 456 persons, with 26 733 randomly assigned to chest radiograph screening and 26 723 to computerized tomography screening. Characteristics of the participants were as follows: 31 533 (59%) were men, 39 234 (73%) were younger than 65 years, 25 779 (48%) were current smokers, and 16 839 (32%) had a college or higher degree. Median cigarette exposure was 48 pack-years. Among Tobacco Use Supplement respondents who met NLST age and smoking history criteria, 59% were men, 65% were younger than 65 years, and 57% were current smokers. Median cigarette exposure among this group was 47 pack-years, and 14% had a college degree or higher. Conclusion The NLST cohort has a distribution of sex and pack-year history that is similar to the component of the general US population that meets the major NLST eligibility criteria; however, NLST participants are younger, better educated, and less likely to be current smokers. PMID:21119104
Pack ice along the Kamchatka Peninsula, Russia as seen from STS-60
NASA Technical Reports Server (NTRS)
1994-01-01
Pack ice is documented in this photograph along the coast of the Kamchatka Peninsula of Russia in Zaliv Ozernoj. Detailed photographs of the ice provide information to scientists in both Russia and the United States about the location and fluctuation of ice edges, and how this new sea ice interacts with ocean and littoral currents.
The Importance of Improving the Nutritional Quality of Packed Lunches in U.S. Schools
ERIC Educational Resources Information Center
Misyak, Sarah; Farris, Alisha; Mann, Georgianna; Serrano, Elena
2015-01-01
Schools represent an ideal venue to influence dietary habits of large numbers of children. While the National School Lunch Program (NSLP) is mandated to meet clear nutrition standards for calories, whole grains, fruits, vegetables, milk, sodium, fat, and saturated fat, there are no nutritional requirements for packed lunches. This Current Issue…
Extreme bottom velocities induced by wind wave and currents in the Gulf of Gdańsk
NASA Astrophysics Data System (ADS)
Cieślikiewicz, Witold; Dudkowska, Aleksandra; Gic-Grusza, Gabriela; Jędrasik, Jan
2017-11-01
The principal goal of this study is to get some preliminary insights about the intensity of water movement generated by wind waves, and due to the currents in the bottom waters of Gulf of Gdańsk, during severe storms. The Gulf of Gdańsk is located in the southern Baltic Sea. This paper presents the results of analysis of wave and current-induced velocities during extreme wind conditions, which are determined based on long-term historical records. The bottom velocity fields originated from wind wave and wind currents, during analysed extreme wind events, are computed independently of each other. The long-term wind wave parameters for the Baltic Sea region are derived from the 44-year hindcast wave database generated in the framework of the project HIPOCAS funded by the European Union. The output from the numerical wave model WAM provides the boundary conditions for the model SWAN operating in high-resolution grid covering the area of the Gulf of Gdańsk. Wind current velocities are calculated with the M3D hydrodynamic model developed in the Institute of Oceanography of the University of Gdańsk based on the POM model. The three dimensional current fields together with trajectories of particle tracers spreading out of bottom boundary layer are modelled, and the calculated fields of bottom velocities are presented in the form of 2D maps. During northerly winds, causing in the Gulf of Gdańsk extreme waves and most significant wind-driven circulation, the wave-induced bottom velocities are greater than velocities due to currents. The current velocities in the bottom layer appeared to be smaller by an order of magnitude than the wave-induced bottom orbital velocities. Namely, during most severe northerly storms analysed, current bottom velocities ranged about 0.1-0.15 m/s, while the root mean square of wave-induced near-seabed velocities reached maximum values of up to 1.4 m/s in the southern part of Gulf of Gdańsk.
Demagnetization using a determined estimated magnetic state
Denis, Ronald J; Makowski, Nathanael J
2015-01-13
A method for demagnetizing comprising positioning a core within the electromagnetic field generated by a first winding until the generated first electrical current is not substantially increasing, thereby determining a saturation current. A second voltage, having the opposite polarity, is then applied across the first winding until the generated second electrical current is approximately equal to the magnitude of the determined saturation current. The maximum magnetic flux within the core is then determined using the voltage across said first winding and the second current. A third voltage, having the opposite polarity, is then applied across the first winding until the core has a magnetic flux equal to approximately half of the determined maximum magnetic flux within the core.
Hao, Tian
2015-02-28
The tap density of a granular powder is often linked to the flowability via the Carr index that measures how tight a powder can be packed, under an assumption that more easily packed powders usually flow poorly. Understanding how particles are packed is important for revealing why a powder flows better than others. There are two types of empirical equations that were proposed to fit the experimental data of packing fractions vs. numbers of taps in the literature: the inverse logarithmic and the stretched exponential. Using the rate process theory and the free volume concept under the assumption that particles will obey similar thermodynamic laws during the tapping process if the "granular temperature" is defined in a different way, we obtain the tap density equations, and they are reducible to the two empirical equations currently widely used in literature. Our equations could potentially fit experimental data better with an additional adjustable parameter. The tapping amplitude and frequency, the weight of the granular materials, and the environmental temperature are grouped into this parameter that weighs the pace of the packing process. The current results, in conjunction with our previous findings, may imply that both "dry" (granular) and "wet" (colloidal and polymeric) particle systems are governed by the same physical mechanisms in term of the role of the free volume and how particles behave (a rate controlled process).
NASA Astrophysics Data System (ADS)
Li, G.; Arnold, L.; Miao, B.; Yan, Y.
2011-12-01
G. Li (1,2), L. Arnold (1), B. Miao (3) and Y. Yan (4) (1) Department of Physics, University of Alabama in Huntsville Huntsville, AL, 35899 (2) CSPAR, University of Alabama in Huntsville Huntsville, AL, 35899 (3) School of Earth and Space Sciences, University of Science and Technology of CHINA, Hefei, China (4) Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Science, Beijing 100012, China Current sheets is a common structure in the solar wind and is a significant source of solar wind MHD turbulence intermittency. The origin of these structure is presently unknown. Non-linear interactions of the solar wind MHD turbulence can spontaneously generate these structures. On the other hand, there are proposals that these structures may represent relic structures having solar origins. Using a technique developed in [1], we examine current sheets in the solar wind from multiple spacecraft. We identify the "single-peak" and "double-peak" events in the solar wind and discuss possible scenarios for these events and its implication of the origin of the current sheets. [1] Li, G., "Identify current-sheet-like structures in the solar wind", ApJL 672, L65, 2008.
Performance of 2G-HTS REBCO undulator coils impregnated epoxies mixed with different fillers
Kesgin, Ibrahim; Hasse, Quentin; Ivanyushenkov, Yury; ...
2016-12-12
The use of second-generation high-temperature superconducting-coated conductors enables an enhancement of the performance of undulator magnets. However, preventing the motion of the wire and providing sufficient conduction cooling to the winding stacks have remained challenges. In this study, we have evaluated epoxy impregnation techniques to address these issues. Epoxy resin was prepared with different nanopowders and the effect on the performance of the undulator coil pack was investigated. All epoxy impregnated coils showed smaller n values and some degree of deterioration of the critical current I c. The I c degradation was most pronounced for epoxy mixed with high aspectmore » ratio multiwalled carbon nanotubes (MWCNTs). It has been found that the crack formation in the epoxy results in plastic deformation of the copper stabilizer layer, which causes the underlying ceramic REBCO superconducting layer to crack resulting in degradation of the superconducting tape performance. As a result, careful adjustment of epoxy thickness surrounding the superconductor and the powder ratio in the epoxy eliminate the performance degradation.« less
Treatment of Ni-EDTA containing wastewater by electrocoagulation using iron scraps packed-bed anode.
Ye, Xiaokun; Zhang, Junya; Zhang, Yan; Lv, Yuancai; Dou, Rongni; Wen, Shulong; Li, Lianghao; Chen, Yuancai; Hu, YongYou
2016-12-01
The unique electrocoagulator proposed in this study is highly efficient at removing Ni-EDTA, providing a potential remediation option for wastewater containing lower concentrations of Ni-EDTA (Ni ≤ 10 mg L -1 ). In the electrocoagulation (EC) system, cylindrical graphite was used as a cathode, and a packed-bed formed from iron scraps was used as an anode. The results showed that the removal of Ni-EDTA increased with the application of current and favoured acidic conditions. We also found that the iron scrap packed-bed anode was superior in its treatment ability and specific energy consumption (SECS) compared with the iron rod anode. In addition, the packed density and temperature had a large influence on the energy consumption (ECS). Over 94.3% of Ni and 95.8% of TOC were removed when conducting the EC treatment at an applied current of 0.5 A, initial pH of 3, air-purged rate 0.2 L min -1 , anode packed density of 400 kg m -3 temperature of 313 K and time of 30 min. SEM analysis of the iron scraps indicated that the specific area of the anode increased after the EC. The XRD analysis of flocs produced during EC revealed that hematite (α-Fe 2 O 3 ) and magnetite (Fe 3 O 4 ) were the main by-products under aerobic and anoxic conditions, respectively. A kinetic study demonstrated that the removal of Ni-EDTA followed a first-order model with the current parameters. Moreover, the removal efficiency of real wastewater was essentially consistent with that of synthetic wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.
Wind turbines: current status, obstacles, trends and technologies
NASA Astrophysics Data System (ADS)
Konstantinidis, E. I.; Botsaris, P. N.
2016-11-01
The last decade the installation of wind farms around the world is spreading rapidly and wind energy has become a significant factor for promoting sustainable development. The scope of the present study is to indicate the present status of global wind power expansion as well as the current state of the art in the field of wind turbine technology. The RAM (reliability/availability/maintenance) section is also examined and the Levelized Cost of Energy for onshore/ offshore electricity production is presented. Negative consequences that go with the rapid expansion of wind power like accidents, environmental effects, etc. are highlighted. Especially visual impact to the landscape and noise pollution are some factors that provoke social reactions. Moreover, the complicated and long permitted process of a wind power plant, the high capital cost of the investment and the grid instability due to the intermittent nature of wind, are also significant obstacles in the development of the wind energy production. The current trends in the field of research and development of onshore and offshore wind power production are analyzed. Finally the present study is trying to achieve an estimation of where the wind industry targets for the years to come.
Evaluation of wind induced currents modeling along the Southern Caspian Sea
NASA Astrophysics Data System (ADS)
Bohluly, Asghar; Esfahani, Fariba Sadat; Montazeri Namin, Masoud; Chegini, Fatemeh
2018-02-01
To improve our understanding of the Caspian Sea hydrodynamics, its circulation is simulated with special focus on wind-driven currents of its southern basin. The hydrodynamic models are forced with a newly developed fine resolution wind field to increase the accuracy of current modeling. A 2D shallow water equation model and a 3D baroclinic model are applied separately to examine the performance of each model for specific applications in the Caspian Sea. The model results are validated against recent field measurements including AWAC and temperature observations in the southern continental shelf region. Results show that the 2D model is able to well predict the depth-averaged current speed in storm conditions in narrow area of southern coasts. This finding suggests physical oceanographers apply 2D modeling as a more affordable method for extreme current speed analysis at the continental shelf region. On the other hand the 3D model demonstrates a better performance in reproducing monthly mean circulation and hence is preferable for surface circulation of Caspian Sea. Monthly sea surface circulation fields of the southern basin reveal a dipole cyclonic-anticyclonic pattern, a dominant eastward current along the southern coasts which intensifies from May to November and a dominant southward current along the eastern coasts in all months except February when the flow is northward. Monthly mean wind fields exhibit two main patterns including a north-south pattern occurring at warm months and collision of two wind fronts especially in the cold months. This collision occurs on a narrow region at the southern continental shelf regions. Due to wind field complexities, it leads to a major source of uncertainty in predicting the wind-driven currents. However, this source of uncertainty is significantly alleviated by applying a fine resolution wind field.
Hogarth, Lee; Maynard, Olivia M; Munafò, Marcus R
2015-01-01
Aims To gain insight into the potential impact of plain tobacco packaging policy, two experiments were undertaken to test whether ‘prototype’ plain compared with branded UK cigarette pack stimuli would differentially elicit instrumental tobacco-seeking in a nominal Pavlovian to instrumental transfer (PIT) procedure. Design, Setting and Participants Two experiments were undertaken at the University of Bristol UK, with a convenience sample of adult smokers (experiment 1, n = 23, experiment 2, n = 121). Measurement In both experiments, smokers were trained on a concurrent choice procedure in which two responses earned points for cigarettes and chocolate, respectively, before images of branded and plain packs were tested for capacity to elicit the tobacco-seeking response in extinction. The primary outcome was percentage choice of the tobacco- over the chocolate-seeking response in plain pack, branded pack and no-stimulus conditions. Findings Both experiments found that branded packs primed a greater percentage of tobacco-seeking (overall mean = 62%) than plain packs (overall mean = 53%) and the no-stimulus condition (overall mean = 52%; Ps ≤ 0.01, ŋp2s ≥ 0.16), and that there was no difference in percentage tobacco-seeking between plain packs and the no-stimulus condition (Ps ≥ 0.17, ŋp2s ≤ 0.04). Plain tobacco packs showed an overall 9% reduction in the priming of a tobacco choice response compared to branded tobacco packs. Conclusions Plain packaging may reduce smoking in current smokers by degrading cue-elicited tobacco-seeking. PMID:25292280
High resolution modelling and observation of wind-driven surface currents in a semi-enclosed estuary
NASA Astrophysics Data System (ADS)
Nash, S.; Hartnett, M.; McKinstry, A.; Ragnoli, E.; Nagle, D.
2012-04-01
Hydrodynamic circulation in estuaries is primarily driven by tides, river inflows and surface winds. While tidal and river data can be quite easily obtained for input to hydrodynamic models, sourcing accurate surface wind data is problematic. Firstly, the wind data used in hydrodynamic models is usually measured on land and can be quite different in magnitude and direction from offshore winds. Secondly, surface winds are spatially-varying but due to a lack of data it is common practice to specify a non-varying wind speed and direction across the full extents of a model domain. These problems can lead to inaccuracies in the surface currents computed by three-dimensional hydrodynamic models. In the present research, a wind forecast model is coupled with a three-dimensional numerical model of Galway Bay, a semi-enclosed estuary on the west coast of Ireland, to investigate the effect of surface wind data resolution on model accuracy. High resolution and low resolution wind fields are specified to the model and the computed surface currents are compared with high resolution surface current measurements obtained from two high frequency SeaSonde-type Coastal Ocean Dynamics Applications Radars (CODAR). The wind forecast models used for the research are Harmonie cy361.3, running on 2.5 and 0.5km spatial grids for the low resolution and high resolution models respectively. The low-resolution model runs over an Irish domain on 540x500 grid points with 60 vertical levels and a 60s timestep and is driven by ECMWF boundary conditions. The nested high-resolution model uses 300x300 grid points on 60 vertical levels and a 12s timestep. EFDC (Environmental Fluid Dynamics Code) is used for the hydrodynamic model. The Galway Bay model has ten vertical layers and is resolved spatially and temporally at 150m and 4 sec respectively. The hydrodynamic model is run for selected hindcast dates when wind fields were highly energetic. Spatially- and temporally-varying wind data is provided by offline coupling with the wind forecast models. Modelled surface currents show good correlation with CODAR observed currents and the resolution of the surface wind data is shown to be important for model accuracy.
NASA Astrophysics Data System (ADS)
Gutierrez, Benjamin T.; Voulgaris, George; Work, Paul A.
2006-03-01
The cross-shore structure of subtidal flows on the inner shelf (7 to 12 m water depth) of Long Bay, South Carolina, a concave-shaped bay, is examined through the analysis of nearly 80 days of near-bed (1.7-2.2 m above bottom) current observations acquired during the spring and fall of 2001. In the spring and under northeastward winds (upwelling favorable) a two-layered flow was observed at depths greater than 10 m, while closer to the shore the currents were aligned with the wind. The two-layered flow is attributed to the presence of stratification, which has been observed under similar conditions in the South Atlantic Bight. When the wind stress was southwestward (downwelling favorable) and exceeded 0.1 N/m2, vertical mixing occurred, the two-layered flow pattern disappeared, and currents were directed alongshore with the wind at all sites and throughout the water column. In the fall, near-bed flows close to the shore (water depth <7 m) were often reduced compared to or opposed those measured farther offshore under southwestward winds. A simplified analysis of the depth-averaged, alongshore momentum balance illustrates that the alongshore pressure gradient approached or exceeded the magnitude of the alongshore wind stress at the same time that the nearshore alongshore current opposed the wind stress and alongshore currents farther offshore. In addition, the analysis suggests that the wind stress is reduced closer to shore so that the alongshore pressure gradient is large enough to drive the flow against the wind.
Modular vaccine packaging increases packing efficiency
Norman, Bryan A.; Rajgopal, Jayant; Lim, Jung; Gorham, Katrin; Haidari, Leila; Brown, Shawn T.; Lee, Bruce Y.
2015-01-01
Background Within a typical vaccine supply chain, vaccines are packaged into individual cylindrical vials (each containing one or more doses) that are bundled together in rectangular “inner packs” for transport via even larger groupings such as cold boxes and vaccine carriers. The variability of vaccine inner pack and vial size may hinder efficient vaccine distribution because it constrains packing of cold boxes and vaccine carriers to quantities that are often inappropriate or suboptimal in the context of country-specific vaccination guidelines. Methods We developed in Microsoft Excel (Microsoft Corp., Redmond, WA) a spreadsheet model that evaluated the impact of different packing schemes for the Benin routine regimen plus the introduction of the Rotarix vaccine. Specifically, we used the model to compare the current packing scheme to that of a proposed modular packing scheme. Results Conventional packing of a Dometic RCW25 that aims to maximize fully-immunized children (FICs) results in 123 FICs and a packing efficiency of 81.93% compared to a maximum of 155 FICs and 94.1% efficiency for an alternative modular packaging system. Conclusions Our analysis suggests that modular packaging systems could offer significant advantages over conventional vaccine packaging systems with respect to space efficiency and potential FICs, when they are stored in standard vaccine carrying devices. This allows for more vaccines to be stored within the same volume while also simplifying the procedures used by field workers to pack storage devices. Ultimately, modular packaging systems could be a simple way to help increase vaccine coverage worldwide. PMID:25957666
Lees, G.W.; McCormick, E.D.
1962-05-22
A tripping circuit employing a magnetic amplifier for tripping a reactor in response to power level, period, or instrument failure is described. A reference winding and signal winding are wound in opposite directions on the core. Current from an ion chamber passes through both windings. If the current increases at too fast a rate, a shunt circuit bypasses one or the windings and the amplifier output reverses polarity. (AEC)
Earth observation taken by the Expedition 28 crew
2011-08-22
ISS028-E-028782 (22 Aug. 2011) --- This panoramic view of recently-formed Hurricane Irene was acquired by the crew of the International Space Station early Monday afternoon from a point over the coastal waters of Venezuela. At the time Irene was packing winds of 80mph and was just north of the Mona Passage between Hispaniola and Puerto Rico. Although no eye was visible at this time, the storm was strengthening and exhibited the size and structure of a classic ?Cape Verde? hurricane as it tracked west-northwestward towards the southern Bahamas.
2004-08-12
ISS009-E-18123 (21:08:33 GMT, 12 August 2004) --- This panoramic view of Hurricane Charley was taken by the Expedition 9 crew of the International Space Station just after 5PM (EDT), August 12, 2004. The Category Two Hurricane was in the northwest Caribbean Sea, 140 miles south-southeast of Havana, Cuba moving north-northwest at 18mph packing winds of 105mph. In this view looking southeast, the newly formed eye of the storm is just visible and the west coast of Florida from Naples to Tampa Bay may be seen on the right.
Earth Obsersation taken by the Expedition 11 crew
2005-07-09
ISS011-E-10258 (9 July 2005) --- This easterly-looking image from the International Space Station shows Hurricane Dennis after the storm had already crossed Cuba and was heading for the northern Gulf of Mexico. Dennis was a Category 3 storm, packing winds of 115 miles per hour, at the time of exposure and located approximately 385 miles southeast of Biloxi, Mississippi or 280 miles south of Panama City, Florida. The ill-defined eye is in the lower right corner. The black triangle in extreme lower right is part of the Space Station's window.
2004-08-13
This panoramic view of Hurricane Charley was photographed by the Expedition 9 crew aboard the International Space Station (ISS) on August 13, 2004, at a vantage point just north of Tampa, Florida. The small eye was not visible in this view, but the raised cloud tops near the center coincide roughly with the time that the storm began to rapidly strengthen. The category 2 hurricane was moving north-northwest at 18 mph packing winds of 105 mph. Crew Earth Observations record Earth surface changes over time, as well as more fleeting events such as storms, floods, fires, and volcanic eruptions.
Surface energy fluxes in complex terrain
NASA Technical Reports Server (NTRS)
Reiter, E. R.; Sheaffer, J. D.; Bossert, J. E.
1986-01-01
The emphasis of the 1985 NASA project activity was on field measurements of wind data and heat balance data. Initiatives included a 19 station mountaintop monitoring program, testing and refining the surface flux monitoring systems and packing and shipping equipment to the People's Republic of China in preparation for the 1986 Tibet Experiment. Other work included more extensive analyses of the 1984 Gobi Desert and Rocky Mountain observations plus some preliminary analyses of the 1985 mountaintop network data. Details of our field efforts are summarized and results of our data analyses are presented.
Local wind forcing of the Monterey Bay area inner shelf
Drake, P.T.; McManus, M.A.; Storlazzi, C.D.
2005-01-01
Wind forcing and the seasonal cycles of temperature and currents were investigated on the inner shelf of the Monterey Bay area of the California coast for 460 days, from June 2001 to September 2002. Temperature measurements spanned an approximate 100 km stretch of coastline from a bluff just north of Monterey Bay south to Point Sur. Inner shelf currents were measured at two sites near the bay's northern shore. Seasonal temperature variations were consistent with previous observations from the central California shelf. During the spring, summer and fall, a seasonal mean alongshore current was observed flowing northwestward in the northern bay, in direct opposition to a southeastward wind stress. A barotropic alongshore pressure gradient, potentially driving the northwestward flow, was needed to balance the alongshore momentum equation. With the exception of the winter season, vertical profiles of mean cross-shore currents were consistent with two-dimensional upwelling and existing observations from upwelling regions with poleward subsurface flow. At periods of 15-60 days, temperature fluctuations were coherent both throughout the domain and with the regional wind field. Remote wind forcing was minimal. During the spring upwelling season, alongshore currents and temperatures in the northern bay were most coherent with winds measured at a nearby land meteorological station. This wind site showed relatively low correlations to offshore buoy wind stations, indicating localized wind effects are important to the circulation along this stretch of Monterey Bay's inner shelf. ?? 2004 Elsevier Ltd. All rights reserved.
Gusts and shear within hurricane eyewalls can exceed offshore wind turbine design standards
NASA Astrophysics Data System (ADS)
Worsnop, Rochelle P.; Lundquist, Julie K.; Bryan, George H.; Damiani, Rick; Musial, Walt
2017-06-01
Offshore wind energy development is underway in the U.S., with proposed sites located in hurricane-prone regions. Turbine design criteria outlined by the International Electrotechnical Commission do not encompass the extreme wind speeds and directional shifts of hurricanes stronger than category 2. We examine a hurricane's turbulent eyewall using large-eddy simulations with Cloud Model 1. Gusts and mean wind speeds near the eyewall of a category 5 hurricane exceed the current Class I turbine design threshold of 50 m s-1 mean wind and 70 m s-1 gusts. Largest gust factors occur at the eye-eyewall interface. Further, shifts in wind direction suggest that turbines must rotate or yaw faster than current practice. Although current design standards omit mention of wind direction change across the rotor layer, large values (15-50°) suggest that veer should be considered.
Gusts and shear within hurricane eyewalls can exceed offshore wind turbine design standards
Worsnop, Rochelle P.; Lundquist, Julie K.; Bryan, George H.; ...
2017-05-30
Here, offshore wind energy development is underway in the U.S., with proposed sites located in hurricane-prone regions. Turbine design criteria outlined by the International Electrotechnical Commission do not encompass the extreme wind speeds and directional shifts of hurricanes stronger than category 2. We examine a hurricane's turbulent eyewall using large-eddy simulations with Cloud Model 1. Gusts and mean wind speeds near the eyewall of a category 5 hurricane exceed the current Class I turbine design threshold of 50 m s –1 mean wind and 70 m s –1 gusts. Largest gust factors occur at the eye-eyewall interface. Further, shifts inmore » wind direction suggest that turbines must rotate or yaw faster than current practice. Although current design standards omit mention of wind direction change across the rotor layer, large values (15–50°) suggest that veer should be considered.« less
Gusts and shear within hurricane eyewalls can exceed offshore wind turbine design standards
DOE Office of Scientific and Technical Information (OSTI.GOV)
Worsnop, Rochelle P.; Lundquist, Julie K.; Bryan, George H.
Here, offshore wind energy development is underway in the U.S., with proposed sites located in hurricane-prone regions. Turbine design criteria outlined by the International Electrotechnical Commission do not encompass the extreme wind speeds and directional shifts of hurricanes stronger than category 2. We examine a hurricane's turbulent eyewall using large-eddy simulations with Cloud Model 1. Gusts and mean wind speeds near the eyewall of a category 5 hurricane exceed the current Class I turbine design threshold of 50 m s –1 mean wind and 70 m s –1 gusts. Largest gust factors occur at the eye-eyewall interface. Further, shifts inmore » wind direction suggest that turbines must rotate or yaw faster than current practice. Although current design standards omit mention of wind direction change across the rotor layer, large values (15–50°) suggest that veer should be considered.« less
Coupled assimilation for an intermediated coupled ENSO prediction model
NASA Astrophysics Data System (ADS)
Zheng, Fei; Zhu, Jiang
2010-10-01
The value of coupled assimilation is discussed using an intermediate coupled model in which the wind stress is the only atmospheric state which is slavery to model sea surface temperature (SST). In the coupled assimilation analysis, based on the coupled wind-ocean state covariance calculated from the coupled state ensemble, the ocean state is adjusted by assimilating wind data using the ensemble Kalman filter. As revealed by a series of assimilation experiments using simulated observations, the coupled assimilation of wind observations yields better results than the assimilation of SST observations. Specifically, the coupled assimilation of wind observations can help to improve the accuracy of the surface and subsurface currents because the correlation between the wind and ocean currents is stronger than that between SST and ocean currents in the equatorial Pacific. Thus, the coupled assimilation of wind data can decrease the initial condition errors in the surface/subsurface currents that can significantly contribute to SST forecast errors. The value of the coupled assimilation of wind observations is further demonstrated by comparing the prediction skills of three 12-year (1997-2008) hindcast experiments initialized by the ocean-only assimilation scheme that assimilates SST observations, the coupled assimilation scheme that assimilates wind observations, and a nudging scheme that nudges the observed wind stress data, respectively. The prediction skills of two assimilation schemes are significantly better than those of the nudging scheme. The prediction skills of assimilating wind observations are better than assimilating SST observations. Assimilating wind observations for the 2007/2008 La Niña event triggers better predictions, while assimilating SST observations fails to provide an early warning for that event.
Excitation system for rotating synchronous machines
Umans, Stephen D.; Driscoll, David J.
2002-01-01
A system for providing DC current to a rotating superconducting winding is provided. The system receives current feedback from the superconducting winding and determines an error signal based on the current feedback and a reference signal. The system determines a control signal corresponding to the error signal and provides a positive and negative superconducting winding excitation voltage based on the control signal.
NASA Astrophysics Data System (ADS)
Fewings, M. R.; Dorman, C. E.; Washburn, L.; Liu, W.
2010-12-01
On the West Coast of North America in summer, episodic relaxation of the upwelling-favorable winds causes warm water to propagate northward from southern to central California, against the prevailing currents [Harms and Winant 1998, Winant et al. 2003, Melton et al. 2009]. Similar wind relaxations are an important characteristic of coastal upwelling ecosystems worldwide. Although these wind relaxations have an important influence on coastal ocean dynamics, no description exists of the regional atmospheric patterns that lead to wind relaxations in southern California, or of the regional ocean response. We use QuikSCAT wind stress, North American Regional Reanalysis atmospheric pressure products, water temperature and velocity from coastal ocean moorings, surface ocean currents from high-frequency radars, and MODIS satellite sea-surface temperature and ocean color images to analyze wind relaxation events and the ocean response. We identify the events based on an empirical index calculated from NDBC buoy winds [Melton et al. 2009]. We describe the regional evolution of the atmosphere from the Gulf of Alaska to Baja California over the few days leading up to wind relaxations, and the coastal ocean temperature, color, and current response off southern and central California. We analyze ~100 wind relaxation events in June-September during the QuikSCAT mission, 1999-2009. Our results indicate south-central California wind relaxations in summer are tied to mid-level atmospheric low-pressure systems that form in the Gulf of Alaska and propagate southeastward over 3-5 days. As the low-pressure systems reach southern California, the atmospheric pressure gradient along the coast weakens, causing the surface wind stress to relax to near zero. The weak wind signal appears first at San Diego and propagates northward. QuikSCAT data indicate the relaxed winds extend over the entire Southern California Bight and up to 200 km offshore of central California. Atmospheric dynamics in the Gulf of Alaska influence ocean conditions in central and southern California via these wind relaxations. The ocean response within a few km of the coast involves poleward-flowing currents that transport warm water out of the lees of capes and headlands and counter to the direction of the California Current [Send et al. 1987, Harms and Winant 1998, Winant et al. 2003, Melton et al. 2009]. A similar response occurs in the Benguela and Canary Current coastal upwelling systems. The ocean response involves both barotropic and baroclinic dynamics and is consistent with existing geophysical models of buoyant, coastally-trapped plumes [Washburn et al., in prep]. Our ongoing work includes i) studying the regional ocean response to determine its spatial extent, time evolution, and ocean-atmosphere coupling dynamics; ii) developing an atmospheric index to predict wind relaxations in southern California based on pressure in the Gulf of Alaska; iii) examining the strength and frequency of wind relaxations over the past 30 years for connections to El Niño and the Pacific Decadal Oscillation; and iv) predicting future variations in wind relaxations and the response of the California Current Large Marine Ecosystem.
NASA Astrophysics Data System (ADS)
Lilover, M.-J.; Pavelson, J.; Kõuts, T.
2014-01-01
This study aims to explain those factors influencing low-frequency currents in a shallow unstratified sea with complex topography. Current velocity measurements using a bottom-mounted ADCP, deployed at 8 m depth on the slope of Naissaar Bank (northern entrance to the Tallinn Bay, Gulf of Finland), were performed over five weeks in late autumn 2008. A quasi-steady current from nine sub-periods (two weeks) was relatively well correlated with wind (mean correlation coefficient of 0.70). During moderate to fresh winds, the current is veered to the right relative to the wind direction, by angles in the range of 14-38°. The flow is directed to the left, relative to the wind direction in stronger wind conditions, indicating evidence of topographic forcing. The observed current was reasonably in accordance with the flow predicted by the classical Ekman model. The modelled current speeds (wind speeds < 11 m s- 1) appear to be overestimated by 3-6 cm s- 1, whilst the observed rotation angles were mostly less than those predicted by the model. Inclusion of barotropic forcing to the Ekman model improved its performance. The discrepancies between the model and observations are discussed in terms of topographic steering, baroclinic effect and surface wave induced forcing.
Energy and Mass Transport of Magnetospheric Plasmas during the November 2003 Magnetic Storm
NASA Technical Reports Server (NTRS)
Fok, Mei-Chging; Moore, Thomas
2008-01-01
Intensive energy and mass transport from the solar wind across the magnetosphere boundary is a trigger of magnetic storms. The storm on 20-21 November 2003 was elicited by a high-speed solar wind and strong southward component of interplanetary magnetic field. This storm attained a minimum Dst of -422 nT. During the storm, some of the solar wind particles enter the magnetosphere and eventually become part of the ring current. At the same time, the fierce solar wind powers strong outflow of H+ and O+ from the ionosphere, as well as from the plasmasphere. We examine the contribution of plasmas from the solar wind, ionosphere and plasmasphere to the storm-time ring current. Our simulation shows, for this particular storm, ionospheric O+ and solar wind ions are the major sources of the ring current particles. The polar wind and plasmaspheric H+ have only minor impacts. In the storm main phase, the strong penetration of solar wind electric field pushes ions from the geosynchronous orbit to L shells of 2 and below. Ring current is greatly intensified during the earthward transport and produces a large magnetic depression in the surface field. When the convection subsides, the deep penetrating ions experience strong charge exchange loss, causing rapid decay of the ring current and fast initial storm recovery. Our simulation reproduces very well the storm development indicated by the Dst index.
Mousa, Mohamed G; Allam, S M; Rashad, Essam M
2018-01-01
This paper proposes an advanced strategy to synchronize the wind-driven Brushless Doubly-Fed Reluctance Generator (BDFRG) to the grid-side terminals. The proposed strategy depends mainly upon determining the electrical angle of the grid voltage, θ v and using the same transformation matrix of both the power winding and grid sides to ensure that the generated power-winding voltage has the same phase-sequence of the grid-side voltage. On the other hand, the paper proposes a vector-control (power-winding flux orientation) technique for maximum wind-power extraction under two schemes summarized as; unity power-factor operation and minimum converter-current. Moreover, a soft-starting method is suggested to avoid the employed converter over-current. The first control scheme is achieved by adjusting the command power-winding reactive power at zero for a unity power-factor operation. However, the second scheme depends on setting the command d-axis control-winding current at zero to maximize the ratio of the generator electromagnetic-torque per the converter current. This enables the system to get a certain command torque under minimum converter current. A sample of the obtained simulation and experimental results is presented to check the effectiveness of the proposed control strategies. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.
While equivalent circuit modeling is an effective way to model the performance and energy efficiency of automotive Li-ion batteries, in some applications it is more convenient to refer directly to round-trip energy efficiency. Energy efficiency of either cells or full packs is se...
Numerical Analysis of Surge Phenomena, Currents, and Pollution Transport in the Sea of Azov
NASA Astrophysics Data System (ADS)
Ivanov, V. A.; Shul'ga, T. Ya.
2018-04-01
Dynamic processes and features of transformation of pollution in the Sea of Azov, caused by the action of a real wind and atmospheric pressure in the presence of stationary currents, are studied using a three-dimensional nonlinear hydrodynamic model. On the basis of numerical calculations, conclusions are reached about the influence of the velocities of stationary background currents on maximal deviations and the velocities of nonstationary currents generated by wind fields in the SKIRON model. It is shown that the combined effect of the constant wind and wind in the SKIRON atmospheric model leads to a significant expansion of the polluted area and to a longer dispersion time compared to the effects of solely stationary currents.
High-Temperature, High-Load-Capacity Radial Magnetic Bearing
NASA Technical Reports Server (NTRS)
Provenza, Andrew; Montague, Gerald; Kascak, Albert; Palazzolo, Alan; Jansen, Ralph; Jansen, Mark; Ebihara, Ben
2005-01-01
A radial heteropolar magnetic bearing capable of operating at a temperature as high as 1,000 F (=540 C) has been developed. This is a prototype of bearings for use in gas turbine engines operating at temperatures and speeds much higher than can be withstood by lubricated rolling-element bearings. It is possible to increase the maximum allowable operating temperatures and speeds of rolling-element bearings by use of cooling-air systems, sophisticated lubrication systems, and rotor-vibration- damping systems that are subsystems of the lubrication systems, but such systems and subsystems are troublesome. In contrast, a properly designed radial magnetic bearing can suspend a rotor without contact, and, hence, without need for lubrication or for cooling. Moreover, a magnetic bearing eliminates the need for a separate damping system, inasmuch as a damping function is typically an integral part of the design of the control system of a magnetic bearing. The present high-temperature radial heteropolar magnetic bearing has a unique combination of four features that contribute to its suitability for the intended application: 1. The wires in its electromagnet coils are covered with an insulating material that does not undergo dielectric breakdown at high temperature and is pliable enough to enable the winding of the wires to small radii. 2. The processes used in winding and potting of the coils yields a packing factor close to 0.7 . a relatively high value that helps in maximizing the magnetic fields generated by the coils for a given supplied current. These processes also make the coils structurally robust. 3. The electromagnets are of a modular C-core design that enables replacement of components and semiautomated winding of coils. 4. The stator is mounted in such a manner as to provide stable support under radial and axial thermal expansion and under a load as large as 1,000 lb (.4.4 kN).
NASA Technical Reports Server (NTRS)
Malaspina, David M.; Newman, David L.; Wilson, Lynn Bruce; Goetz, Keith; Kellogg, Paul J.; Kerstin, Kris
2013-01-01
A strong spatial association between bipolar electrostatic solitary waves (ESWs) and magnetic current sheets (CSs) in the solar wind is reported here for the first time. This association requires that the plasma instabilities (e.g., Buneman, electron two stream) which generate ESWs are preferentially localized to solar wind CSs. Distributions of CS properties (including shear angle, thickness, solar wind speed, and vector magnetic field change) are examined for differences between CSs associated with ESWs and randomly chosen CSs. Possible mechanisms for producing ESW-generating instabilities at solar wind CSs are considered, including magnetic reconnection.
Lee, J; Scheraga, H A; Rackovsky, S
1996-01-01
The lateral packing of a collagen-like molecule, CH3CO-(Gly-L-Pro-L-Pro)4-NHCH3, has been examined by energy minimization with the ECEPP/3 force field. Two current packing models, the Smith collagen microfibril twisted equilateral pentagonal model and the quasi-hexagonal packing model, have been extensively investigated. In treating the Smith microfibril model, energy minimization was carried out on various conformations including those with the symmetry of equivalent packing, i.e., in which the triple helices were arranged equivalently with respect to each other. Both models are based on the experimental observation of the characteristic axial periodicity, D = 67 nm, of light and dark bands, indicating that, if any superstructure exists, it should consist of five triple helices. The quasi-hexagonal packing structure is found to be energetically more favorable than the Smith microfibril model by as much as 31.2 kcal/mol of five triple helices. This is because the quasi-hexagonal packing geometry provides more nonbonded interaction possibilities between triple helices than does the Smith microfibril geometry. Our results are consistent with recent x-ray studies with synthetic collagen-like molecules and rat tail tendon, in which the data were interpreted as being consistent with either a quasi-hexagonal or a square-triangular structure.
An evaluation of ERTS data for oceanographic uses through Great Lakes studies
NASA Technical Reports Server (NTRS)
Strong, A. E. (Principal Investigator); Stumpf, H. G.
1974-01-01
The author has identified the following significant results. Prevailing wind direction on Lake Michigan is southwesterly, although during winter northwesterly stresses are common. Along the western shore the current favors a northward direction. ERTS-1 observations indicate that the southward-flowing current along the Michigan shoreline of the thumb is only reversed by southerly resultant wind stress. Along the Canadian shoreline, a northward current was observed north of Kettle Point. ERTS-1 data also reveal that a preferred southward-flowing current is found along the Detroit shoreline of Lake St. Clair. Eastward flow of surface water from the shallow western basin of Lake Erie into the middle basin is most obvious during northwesterly and northerly wind stresses. The reverse wind direction especially east and southeasterly, appear to hold the effluents from the Detroit and Maumee Rivers in the western basin. Across-lake winds from the north and south induce eddy-like circulation in surface waters of Lake Ontario. Counterclockwise alongshore flow persists in the western basin under most wind conditions.
Observations of currents and density structure across a buoyant plume front
Gelfenbaum, G.; Stumpf, R.P.
1993-01-01
Observations of the Mobile Bay, Alabama, plume during a flood event in April 1991 reveal significant differences in the current field on either side of a front associated with the buoyant plume. During a strong southeasterly wind, turbid, low salinity water from Mobile Bay was pushed through an opening in the west side of the ebb-tidal delta and moved parallel to the coast. A stable front developed between the low salinity water of the buoyant plume (11‰) and the high salinity coastal water (>23‰) that was being forced landward by the prevailing winds. Despite the shallow water depth of 6 m, measurements of currents, temperature, and salinity show large shears and density gradients in both the vertical and the horizontal directions. At a station outside of the buoyant plume, currents at 0.5 m and 1.5 m below the surface were in the same direction as the wind. Inside the plume, however, currents at 0.5 m below the surface were parallel to the coast, 45°, off the direction of the wind and the magnitude was 45% larger than the magnitude of the surface currents outside the plume. Beneath the level of the plume, the currents were identical to the wind-driven currents in the ambient water south of the front. Our observations suggest that the wind-driven surface currents of the ambient water converged with the buoyant plume at the front and were subducted beneath the plume. The motion of the ambient coastal surface water was in the direction of the local wind stress, however, the motion of the plume had no northerly component of motion. The plume also did not show any flow toward the front, suggesting a balance between the northerly component of wind stress and the southerly component of buoyant spreading. In addition, the motion of the plume did not appear to affect the motion of the underlying ambient water, suggesting a lack of mixing between the two waters.
2012-01-01
Background Tobacco use is responsible for 5.4 million deaths every year worldwide and is a leading cause of preventable death. The burden of these deaths is rapidly shifting to low and middle-income countries, such as Brazil. Brazil has prohibited most forms of tobacco advertising; however, the cigarette pack remains a primary source of marketing. The current study examined how tobacco packaging influences brand appeal and perceptions of health risk among young women in Brazil. Methods A between-subjects experiment was conducted in which 640 Brazilian women aged 16–26 participated in an online survey. Participants were randomized to view 10 cigarette packages according to one of three experimental conditions: standard branded packages, the same packs without brand imagery (“plain packaging”), or the same packs without brand imagery or descriptors (e.g., flavors). Participants rated packages on perceived appeal, taste, health risk, smoothness, and smoker attributes. Finally, participants were shown a range of branded and plain packs from which they could select one as a free gift, which constituted a behavioral measure of appeal. Results Branded packs were rated as significantly more appealing, better tasting, and smoother on the throat than plain packs. Branded packs were also associated with a greater number of positive smoker attributes including style and sophistication, and were perceived as more likely to be smoked by females than the plain packs. Removing descriptors from the plain packs further decreased the ratings of appeal, taste and smoothness, and also reduced associations with positive attributes. In the pack offer, participants were three times more likely to select branded packs than plain packs. Conclusions Plain packaging and removal of descriptors may reduce the appeal of smoking for youth and young adults, and consequently reduce smoking susceptibility. Overall, the findings provide support for plain packaging regulations, such as those in Australia. PMID:22943135
White, Christine M; Hammond, David; Thrasher, James F; Fong, Geoffrey T
2012-09-04
Tobacco use is responsible for 5.4 million deaths every year worldwide and is a leading cause of preventable death. The burden of these deaths is rapidly shifting to low and middle-income countries, such as Brazil. Brazil has prohibited most forms of tobacco advertising; however, the cigarette pack remains a primary source of marketing. The current study examined how tobacco packaging influences brand appeal and perceptions of health risk among young women in Brazil. A between-subjects experiment was conducted in which 640 Brazilian women aged 16-26 participated in an online survey. Participants were randomized to view 10 cigarette packages according to one of three experimental conditions: standard branded packages, the same packs without brand imagery ("plain packaging"), or the same packs without brand imagery or descriptors (e.g., flavors). Participants rated packages on perceived appeal, taste, health risk, smoothness, and smoker attributes. Finally, participants were shown a range of branded and plain packs from which they could select one as a free gift, which constituted a behavioral measure of appeal. Branded packs were rated as significantly more appealing, better tasting, and smoother on the throat than plain packs. Branded packs were also associated with a greater number of positive smoker attributes including style and sophistication, and were perceived as more likely to be smoked by females than the plain packs. Removing descriptors from the plain packs further decreased the ratings of appeal, taste and smoothness, and also reduced associations with positive attributes. In the pack offer, participants were three times more likely to select branded packs than plain packs. Plain packaging and removal of descriptors may reduce the appeal of smoking for youth and young adults, and consequently reduce smoking susceptibility. Overall, the findings provide support for plain packaging regulations, such as those in Australia.
Pearson, Jennifer L; Richardson, Amanda; Feirman, Shari P; Villanti, Andrea C; Cantrell, Jennifer; Cohn, Amy; Tacelosky, Michael; Kirchner, Thomas R
2016-08-01
In 2015, the Food and Drug Administration issued warnings to three tobacco manufacturers who label their cigarettes as "additive-free" and/or "natural" on the grounds that they make unauthorized reduced risk claims. The goal of this study was to examine US adults' perceptions of three American Spirit (AS) pack descriptors ("Made with Organic Tobacco," "100% Additive-Free," and "100% US Grown Tobacco") to assess if they communicate reduced risk. In September 2012, three cross-sectional surveys were posted on Amazon Mechanical Turk. Adult participants evaluated the relative harm of a Marlboro Red pack versus three different AS packs with the descriptors "Made with Organic Tobacco," "100% Additive-Free," or "100% US Grown Tobacco" (Survey 1; n = 461); a Marlboro Red pack versus these AS packs modified to exclude descriptors (Survey 2; n = 857); and unmodified versus modified AS pack images (Survey 3; n = 1001). The majority of Survey 1 participants rated the unmodified AS packs as less harmful than the Marlboro Red pack; 35.4%-58.8% of Survey 2 participants also rated the modified (no claims) packs as less harmful than Marlboro Red. In these surveys, prior use of AS cigarettes was associated with reduced perceptions of risk (adjusted odds ratio [AOR] 1.59-2.40). "Made with Organic Tobacco" and "100% Additive-Free" were associated with reduced perceptions of risk when comparing the modified versus the unmodified AS packs (Survey 3). Data suggest that these AS pack descriptors communicate reduced harm messages to consumers. Findings have implications for regulatory actions related to product labeling and packaging. These findings provide additional evidence that the "Made with Organic Tobacco," "100% Additive-Free," and "100% US Grown" descriptors, as well as other aspects of the AS pack design, communicate reduced harm to non-, current, and former smokers. Additionally, they provide support for the importance of FDA's 2015 warning to Santa Fe Natural Tobacco Company on "100% Additive Free" as an unauthorized modified risk claim. © The Author 2016. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Empirical models of wind conditions on Upper Klamath Lake, Oregon
Buccola, Norman L.; Wood, Tamara M.
2010-01-01
Upper Klamath Lake is a large (230 square kilometers), shallow (mean depth 2.8 meters at full pool) lake in southern Oregon. Lake circulation patterns are driven largely by wind, and the resulting currents affect the water quality and ecology of the lake. To support hydrodynamic modeling of the lake and statistical investigations of the relation between wind and lake water-quality measurements, the U.S. Geological Survey has monitored wind conditions along the lakeshore and at floating raft sites in the middle of the lake since 2005. In order to make the existing wind archive more useful, this report summarizes the development of empirical wind models that serve two purposes: (1) to fill short (on the order of hours or days) wind data gaps at raft sites in the middle of the lake, and (2) to reconstruct, on a daily basis, over periods of months to years, historical wind conditions at U.S. Geological Survey sites prior to 2005. Empirical wind models based on Artificial Neural Network (ANN) and Multivariate-Adaptive Regressive Splines (MARS) algorithms were compared. ANNs were better suited to simulating the 10-minute wind data that are the dependent variables of the gap-filling models, but the simpler MARS algorithm may be adequate to accurately simulate the daily wind data that are the dependent variables of the historical wind models. To further test the accuracy of the gap-filling models, the resulting simulated winds were used to force the hydrodynamic model of the lake, and the resulting simulated currents were compared to measurements from an acoustic Doppler current profiler. The error statistics indicated that the simulation of currents was degraded as compared to when the model was forced with observed winds, but probably is adequate for short gaps in the data of a few days or less. Transport seems to be less affected by the use of the simulated winds in place of observed winds. The simulated tracer concentration was similar between model results when simulated winds were used to force the model, and when observed winds were used to force the model, and differences between the two results did not accumulate over time.
Madl, Amy K; Clark, Katherine; Paustenbach, Dennis J
2007-01-01
In recent years, questions have been raised about the health risks to persons who have been occupationally exposed to asbestos-containing gaskets and packing materials used in pipes, valves, and machinery (pumps, autos, etc.). Up until the late 1970s, these materials were widely used throughout industrial and maritime operations, refineries, chemical plants, naval ships, and energy plants. Seven simulation studies and four work-site industrial hygiene studies of industrial and maritime settings involving the collection of more than 300 air samples were evaluated to determine the likely airborne fiber concentrations to which a worker may have been exposed while working with encapsulated asbestos-containing gaskets and packing materials. Each study was evaluated for the representativeness of work practices, analytical methods, sample size, and potential for asbestos contamination (e.g., insulation on valves or pipes used in the study). Specific activities evaluated included the removal and installation of gaskets and packings, flange cleaning, and gasket formation. In all but one of the studies relating to the replacement of gaskets and packing using hand-held tools, the short-term average exposures were less than the current 30-min OSHA excursion limit of 1 fiber per cubic centimeter (f/cc) and all of the long-term average exposures were less than the current 8-h permissible exposure limit time-weighted average (PEL-TWA) of 0.1 f/cc. The weight of evidence indicates that the use of hand tools and hand-operated power tools to remove or install gaskets or packing as performed by pipefitters or other tradesmen in nearly all plausible situations would not have produced airborne concentrations in excess of contemporaneous regulatory levels.
Effect of wave-current interaction on wind-driven circulation in narrow, shallow embayments
Signell, Richard P.; Beardsley, Robert C.; Graber, H. C.; Capotondi, A.
1990-01-01
The effect of wind waves on the steady wind-driven circulation in a narrow, shallow bay is investigated with a two-dimensional (y, z) circulation model and the Grant and Madsen [1979] bottom-boundary layer model, which includes wave-current interaction. A constant wind stress is applied in the along-channel x direction to a channel with a constant cross-sectional profile h(y). The wind-induced flushing of shallow bays is shown to be sensitive to both the shape of the cross section and the effects of surface waves. The flushing increases with increasing , where h′ is the standard deviation of cross-channel depth and is the mean depth. This is consistent with the findings of Hearn et al. [1987]. The flushing decreases, however, with the inclusion of surface wave effects which act to increase the bottom drag felt by the currents. Increasing effective bottom friction reduces the strength of the circulation, while the along-bay surface slope, bottom stress and the structure of current profiles remain nearly unchanged. An implication of the circulation dependence on wave-current interaction is that low-frequency oscillatory winds may drive a mean circulation when the wave field changes with wind direction.x
Meernik, Clare; Ranney, Leah M; Lazard, Allison J; Kim, KyungSu; Queen, Tara L; Avishai, Aya; Boynton, Marcella H; Sheeran, Paschal J; Goldstein, Adam O
2018-01-01
Product packaging has long been used by the tobacco industry to target consumers and manipulate product perceptions. This study examines the extent to which cigarillo packaging influences perceptions of product flavor, taste, smell, and appeal. A web-based experiment was conducted among young adults. Participants viewed three randomly selected cigarillo packs, varying on pack flavor descriptor, color, type, branding, and warning-totaling 180 pack images. Mixed-effects models were used to estimate the effect of pack elements on product perceptions. A total of 2,664 current, ever, and never little cigar and cigarillo users participated. Cigarillo packs with a flavor descriptor were perceived as having a more favorable taste (β = 0.21, p < .001) and smell (β = 0.14, p < .001) compared to packs with no flavor descriptor. Compared to packs with no color, pink and purple packs were more likely to be perceived as containing a flavor (β = 0.11, p < .001), and were rated more favorably on taste (β = 0.17, p < .001), smell (β = 0.15, p < .001), and appeal (β = 0.16, p < .001). While warnings on packs decreased favorable perceptions of product taste (pictorial: β = -0.07, p = .03) and smell (text-only: β = -0.08, p = .01; pictorial: β = -0.09, p = .007), warnings did not moderate the effects of flavor descriptor or color. To our knowledge, this study provides the first quantitative evidence that cigarillo packaging alters consumers' cognitive responses, and warnings on packs do not suffice to overcome the effects of product packaging. The findings support efforts at federal, state, and local levels to prohibit flavor descriptors and their associated product flavoring in non-cigarette products such as cigarillos, along with new data that supports restrictions on flavor cues and colors.
Cigarette pack design and perceptions of risk among UK adults and youth.
Hammond, David; Dockrell, Martin; Arnott, Deborah; Lee, Alex; McNeill, Ann
2009-12-01
It is illegal in the EU for tobacco packaging to suggest that some cigarettes are safer than others. This study examined consumer perceptions of cigarette packs in the UK, including perceptions of 'plain packaging', in which colour and other design elements are removed, whilst retaining the brand name. 516 adult smokers and 806 youth aged 11-17 participated in an online survey. Participants were asked to compare pairs of cigarette packs on five measures: taste, tar delivery, health risk, attractiveness and either ease of quitting (adult smokers) or brand they would choose if trying smoking (youth). Adults and youth were significantly more likely to rate packs with the terms 'smooth', 'silver' and 'gold' as lower tar, lower health risk and either easier to quit smoking (adults) or their choice of pack if trying smoking (youth). For example, more than half of adults and youth reported that brands labelled as 'smooth' were less harmful compared with the 'regular' variety. The colour of packs was also associated with perceptions of risk and brand appeal: compared with Marlboro packs with a red logo, Marlboro packs with a gold logo were rated as lower health risk by 53% and easier to quit by 31% of adult smokers. Plain packs significantly reduced false beliefs about health risk and ease of quitting, and were rated as significantly less attractive and appealing to youth for trying smoking. Current regulations have failed to remove potentially misleading information from tobacco packaging. Removing colours from packs (plain packaging), as well as terms such as 'smooth' 'gold' and 'silver' would significantly reduce false beliefs and increase compliance with existing legislation.
Graphic Health Warnings on Cigarette Packs: How Long Before the Effects on Adolescents Wear Out?
White, Victoria; Bariola, Emily; Faulkner, Agatha; Coomber, Kerri; Wakefield, Melanie
2015-07-01
To examine the long-term impact of graphic health-warning labels (GHWL) on adolescents' cognitive processing of warning labels and cigarette pack perceptions. Cross-sectional school-based surveys of students aged 13-17 years residing in urban centers, conducted prior to GHWL introduction (2005) and 6 months (2006), 2 years (2008), and 5 years (2011) post-GHWL introduction. Students who had seen a cigarette pack in the previous 6 months or in 2006, who had seen GHWL were included in analyses (2005 n = 2,560; 2006 n = 1,306; 2008 n = 2,303; 2011 n = 2,716). Smoking stage, reported exposure to cigarette packs, cognitive processing of GHWL, and positive and negative perceptions of pack image were assessed. While cognitive processing of GHWL in 2006 and 2008 was greater than 2005 (p < .01), by 2011 scores had returned to 2005 levels. This pattern of change was consistent across smoking status groups. Pack image perceptions became more negative over time among all students, irrespective of smoking experience. While positive pack image ratings were lower in all subsequent years than 2005, the 2008 rating was higher than 2006 (p < .01). A significant interaction between survey time and smoking status (p < .01) showed that significant increases in positive pack ratings after 2006 only occurred among current and experimental smokers. When novel, GHWL on cigarette packs increase cognitive processing among adolescents. However, this effect diminishes after 5 years, suggesting more regular message refreshment is needed. Australia's adoption of plain packaging is intended to undermine positive pack appeal and increase warning salience. © The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Andrews, J Craig; Netemeyer, Richard G; Burton, Scot; Kees, Jeremy
2016-12-01
The purpose of this study is to provide an experimental test of the effects of plain pack branding and graphic health warnings (GHWs) in three different countries for an important and vulnerable population, that is, adolescents who are experimenting with smoking. The effects of plain pack branding (logo present, logo absent), and graphic visual warning level (absent, low, medium, high) are studied experimentally for their impact on adolescent cigarette craving, evoked fear, pack feelings and thoughts of quitting in the USA, Spain and France. A total of 1066 adolescents who were experimenting with smoking served as participants in the study. A quota sample produced 375 respondents in the USA, 337 in Spain and 354 in France. Overall findings indicate that the GHWs were effective in impacting adolescent cigarette craving, evoked fear, pack feelings and thoughts of quitting. The plain pack effects were not as strong, yet reduced craving, increased fear, and decreased pack feelings for all three samples combined, and for US adolescent smokers individually, irrespective of the GHWs. For French adolescent smokers, plain pack effects for craving were limited to low/moderate GHW levels. For Spanish adolescent smokers, plain pack feeling effects were limited to the absence of the GHWs. The results show that plain packs can independently strengthen the more instantaneous, direct effects (short of quitting thoughts) found with the GHWs. Yet, the plain pack results were attenuated for Spanish and French adolescent smokers, who are currently exposed to GHWs. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
Maynard, Olivia M; Leonards, Ute; Attwood, Angela S; Bauld, Linda; Hogarth, Lee; Munafò, Marcus R
2015-03-13
Plain packaging requires tobacco products to be sold in packs with a standard shape, method of opening and colour, leaving the brand name in a standard font and location. We ran a randomised controlled trial to investigate the impact of plain packaging on smoking behaviour and attitudes. In a parallel group randomised trial design, 128 daily smokers smoked cigarettes from their usual UK brand, or a plain Australian brand that was closely matched to their usual UK brand for 24 hours. Primary outcomes were number of cigarettes smoked and volume of smoke inhaled per cigarette. Secondary outcomes were self-reported ratings of motivation to quit, cigarette taste, experience of using the pack, experience of smoking, attributes of the pack, perceptions of the health warning, changes in smoking behaviour, and views on plain packaging. There was no evidence that pack type had an effect on either of the primary measures (ps > 0.279). However, smokers using plain cigarette packs rated the experience of using the pack more negatively (-0.52, 95% CI -0.82 to -0.22, p = 0.001), rated the pack attributes more negatively (-1.59, 95% CI -1.80 to -1.39, p < 0.001), and rated the health warning as more impactful (+0.51, 95% CI 0.24 to 0.78, p < 0.001). Plain cigarette packs reduce ratings of the experience of using the cigarette pack, and ratings of the pack attributes, and increase the self-perceived impact of the health warning, but do not change smoking behaviour, at least in the short term. Current Controlled Trials ISRCTN52982308. Registered 27 June 2013.
21 CFR 110.5 - Current good manufacturing practice.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Current good manufacturing practice. 110.5 Section...) FOOD FOR HUMAN CONSUMPTION CURRENT GOOD MANUFACTURING PRACTICE IN MANUFACTURING, PACKING, OR HOLDING HUMAN FOOD General Provisions § 110.5 Current good manufacturing practice. (a) The criteria and...
21 CFR 210.2 - Applicability of current good manufacturing practice regulations.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Applicability of current good manufacturing... AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE IN MANUFACTURING, PROCESSING, PACKING, OR HOLDING OF DRUGS; GENERAL § 210.2 Applicability of current good manufacturing...
2014-07-01
Various factors such as winds , river discharges, and detached eddies from the Loop Current can contribute to the generation of currents over the...component of transport over the inner shelf is produced by wind (40–48%), with river discharge (28–33%) and Loop Current (LC) eddies (19–33...accounting for the rest (Oey, 1995). Two seasonal current patterns that depend on wind characteristics are distinguishable over the shelf (Cho, Reid, and
Contactless system of excitation current measurement in the windings with high inductance
NASA Astrophysics Data System (ADS)
Chubraeva, L.; Evseev, E.; Timofeev, S.
2018-02-01
The results of development, manufacturing and testing of a special contactless maintenance-free excitation current measurement system intended for the windings with high inductance, typical for superconductive alternators, are presented. The system was assembled on the brushless exciter is intended for 1 MVA wind-power generator with the winding, manufactured of high-temperature superconductors (HTSC). The alternator with brushless exciter were manufactured and successfully tested.
1982-12-01
1Muter.Te Motions Based on Ana lyzed Winds and wind-driven December 1982 Currents from. a Primitive Squat ion General a.OW -love"*..* Oean Circulation...mew se"$ (comeS.... do oISN..u am ae~ 00do OWaor NUN Fourier and Rotary Spc , Analysis Modeled Inertial and Subinrtial Motion 4 Primitive Equation
Transformer current sensor for superconducting magnetic coils
Shen, Stewart S.; Wilson, C. Thomas
1988-01-01
A transformer current sensor having primary turns carrying a primary current for a superconducting coil and secondary turns only partially arranged within the primary turns. The secondary turns include an active winding disposed within the primary turns and a dummy winding which is not disposed in the primary turns and so does not experience a magnetic field due to a flow of current in the primary turns. The active and dummy windings are wound in opposite directions or connected in series-bucking relationship, and are exposed to the same ambient magnetic field. Voltages which might otherwise develop in the active and dummy windings due to ambient magnetic fields thus cancel out. The resultant voltage is purely indicative of the rate of change of current flowing in the primary turns.
Pack-and-Go Delivery Service: A Multi-Component Cost-Volume-Profit (CVP) Learning Resource
ERIC Educational Resources Information Center
Stout, David E.
2014-01-01
This educational case, in two parts (A and B), requires students to assume the role of a business consultant and to use Excel to develop a profit-planning or a cost-volume-profit (CVP) model for a package-delivery company opportunity currently being evaluated by a client. The name of the proposed business is Pack-and-Go, which would provide an…
Microbiology of Wind-eroded Sediments: Current Knowledge and Future Research Directions
USDA-ARS?s Scientific Manuscript database
Wind erosion is a threat to the sustainability and productivity of soils that takes place at local, regional, and global scales. Current estimates of cost of wind erosion have not included the costs associated with the loss of soil biodiversity and reduced ecosystem functions. Microorganisms carrie...
Fong, D.A.; Geyer, W.R.; Signell, R.P.
1997-01-01
The Freshwater plume in the western Gulf of Maine is being studied as part of an interdisciplinary investigation of the physical transport of a toxic alga. A field program was conducted in the springs of 1993 and 1994 to map the spatial and temporal patterns of salinity, currents and algal toxicity. The observations suggest that the plume's cross-shore structure varies markedly as a function of fluctuations in alongshore wind forcing. Consistent with Ekman drift dynamics, upwelling favorable winds spread the plume offshore, at times widening it to over 50 km in offshore extent, while downwelling favorable winds narrow the plume width to as little as 10 km. Using a simple slab model, we find qualitative agreement between the observed variations of plume width and those predicted by Ekman theory for short time scales of integration. Near surface current meters show significant correlations between cross-shore currents and alongshore wind stress, consistent with Ekman theory. Estimates of the terms in the alongshore momentum equation calculated from moored current meter arrays also indicate a dominant Ekman balance within the plume. A significant correlation between alongshore currents and winds suggests that interfacial drag may be important, although inclusion of a Raleigh drag term does not significantly improve the alongshore momentum balance.
2013 Cost of Wind Energy Review
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mone, C.; Smith, A.; Maples, B.
2015-02-01
This report uses representative project types to estimate the levelized cost of wind energy (LCOE) in the United States for 2013. Scheduled to be published on an annual basis, it relies on both market and modeled data to maintain a current understanding of wind generation cost trends and drivers. It is intended to provide insight into current component-level costs and a basis for understanding current component-level costs and a basis for understanding variability in the LCOE across the industry. Data and tools developed from this analysis are used to inform wind technology cost projections, goals, and improvement opportunities.
A real-time insulation detection method for battery packs used in electric vehicles
NASA Astrophysics Data System (ADS)
Tian, Jiaqiang; Wang, Yujie; Yang, Duo; Zhang, Xu; Chen, Zonghai
2018-05-01
Due to the energy crisis and environmental pollution, electric vehicles have become more and more popular. Compared to traditional fuel vehicles, the electric vehicles are integrated with more high-voltage components, which have potential security risks of insulation. The insulation resistance between the chassis and the direct current bus of the battery pack is easily affected by factors such as temperature, humidity and vibration. In order to ensure the safe and reliable operation of the electric vehicles, it is necessary to detect the insulation resistance of the battery pack. This paper proposes an insulation detection scheme based on low-frequency signal injection method. Considering the insulation detector which can be easily affected by noises, the algorithm based on Kalman filter is proposed. Moreover, the battery pack is always in the states of charging and discharging during driving, which will lead to frequent changes in the voltage of the battery pack and affect the estimation accuracy of insulation detector. Therefore the recursive least squares algorithm is adopted to solve the problem that the detection results of insulation detector mutate with the voltage of the battery pack. The performance of the proposed method is verified by dynamic and static experiments.
Simulating Sources of Superstorm Plasmas
NASA Technical Reports Server (NTRS)
Fok, Mei-Ching
2008-01-01
We evaluated the contributions to magnetospheric pressure (ring current) of the solar wind, polar wind, auroral wind, and plasmaspheric wind, with the surprising result that the main phase pressure is dominated by plasmaspheric protons. We used global simulation fields from the LFM single fluid ideal MHD model. We embedded the Comprehensive Ring Current Model within it, driven by the LFM transpolar potential, and supplied with plasmas at its boundary including solar wind protons, polar wind protons, auroral wind O+, and plasmaspheric protons. We included auroral outflows and acceleration driven by the LFM ionospheric boundary condition, including parallel ion acceleration driven by upward currents. Our plasmasphere model runs within the CRCM and is driven by it. Ionospheric sources were treated using our Global Ion Kinetics code based on full equations of motion. This treatment neglects inertial loading and pressure exerted by the ionospheric plasmas, and will be superceded by multifluid simulations that include those effects. However, these simulations provide new insights into the respective role of ionospheric sources in storm-time magnetospheric dynamics.
Rapid response to coastal upwelling in a semienclosed bay
NASA Astrophysics Data System (ADS)
Gilcoto, Miguel; Largier, John L.; Barton, Eric D.; Piedracoba, Silvia; Torres, Ricardo; Graña, Rocío.; Alonso-Pérez, Fernando; Villacieros-Robineau, Nicolás.; de la Granda, Francisco
2017-03-01
Bays/estuaries forced by local wind show bidirectional exchange flow. When forced by remote wind, they exhibit unidirectional flow adjustment to coastal sea level. Acoustic Doppler Current Profiler observations over 1 year show that the Ria de Vigo (Iberian Upwelling) responds to coastal wind events with bidirectional exchange flow. The duration of the upwelling and downwelling events, estimated from the current variability, was 3.3 days and 2.6 days, respectively. Vectorial correlations reveal a rapid response to upwelling/downwelling, in which currents lag local wind by <6 h and remote wind by <14 h, less than the Ekman spinup (17.8 h). This rapidity arises from the ria's narrowness (nonrotational local response), equatorward orientation (additive remote and local wind responses), depth greater than the Ekman depth (penetration of shelf circulation into the interior), and vertical stratification (shear reinforcing shelf circulation). Similar rapid responses are expected in other narrow bays where local and remote winds act together and stratification enhances bidirectional flow.
Performance and Safety Characteristics of Sanyo NiCd Cells
NASA Technical Reports Server (NTRS)
Deng, Yi; Jeevarajan, Judith; Bragg, Bobby; Zhang, Wenlin
2002-01-01
NiCd batteries are widely used for high drain applications like power tools and also in other portable equipment like cameras, PCs, etc. NASA and Dreamtime Holdings, Inc. worked together to have the capability of a High Definition TV (HDTV) on the ISS and Space Shuttle. The Sanyo HD camcorder was used on the STS 105 fight in July, 2001 . The camcorder used two versions of a NiCd battery. One was a cOlnmercial off-the-shelf Sony BP90 battery pack that had Sanyo NiCd D cells. The other was a modified battery (FBP-90) made by Frezzi Energy, which also had the same Sanyo NiCd D cells. The battery has 10 NiCd D cells in series to form a 12 V pack with 5.0 Ah capacity. Our current study involved the perforn1ance and abuse tests on the Sanyo NiCd 5.0 Ah D cells. The best combination of charge/discharge current rate is 0.3C for charge and 1/2e for discharge within 200 cycles. No significant changes in capacity were observed in 200 cycles. The cell also showed capability of 5C (25.0A) high rate discharge. In overcharge and overdischarge tests, all tested cells passed the tests without venting. In imbalance tests, the battery pack could be charged and discharged only at relatively low current. At charge current of 1.0A or less, the imbalanced cells in the battery pack displayed relatively high temperatures during charge or discharge. The cells functioned normally during internal short and no mishap occurred during external short. Cells passed exposure tests at 80 C and no leakage till 150 C during heat-tovent tests.
Wind-driven coastal upwelling and westward circulation in the Yucatan shelf
NASA Astrophysics Data System (ADS)
Ruiz-Castillo, Eugenio; Gomez-Valdes, Jose; Sheinbaum, Julio; Rioja-Nieto, Rodolfo
2016-04-01
The wind-driven circulation and wind-induced coastal upwelling in a large shelf sea with a zonally oriented coast are examined. The Yucatan shelf is located to the north of the Yucatan peninsula in the eastern Gulf of Mexico. This area is a tropical shallow body of water with a smooth sloping bottom and is one of the largest shelves in the world. This study describes the wind-driven circulation and wind-induced coastal upwelling in the Yucatan shelf, which is forced by easterly winds throughout the year. Data obtained from hydrographic surveys, acoustic current profilers and environmental satellites are used in the analysis. Hydrographic data was analyzed and geostrophic currents were calculated in each survey. In addition an analytical model was applied to reproduce the currents. The results of a general circulation model were used with an empirical orthogonal function analysis to study the variability of the currents. The study area is divided in two regions: from the 40 m to the 200 m isobaths (outer shelf) and from the coast to the 40 m isobath (inner shelf). At the outer shelf, observations revealed upwelling events throughout the year, and a westward current with velocities of approximately 0.2 m s-1 was calculated from the numerical model output and hydrographic data. In addition, the theory developed by Pedlosky (2007) for a stratified fluid along a sloping bottom adequately explains the current's primary characteristics. The momentum of the current comes from the wind, and the stratification is an important factor in its dynamics. At the inner shelf, observations and numerical model output show a wind-driven westward current with maximum velocities of 0.20 m s-1. The momentum balance in this region is between local acceleration and friction. A cold-water band is developed during the period of maximum upwelling.
Modeling of the coupled magnetospheric and neutral wind dynamos
NASA Technical Reports Server (NTRS)
Thayer, Jeff P.
1993-01-01
The solar wind interaction with the earth's magnetosphere generates electric fields and currents that flow from the magnetosphere to the ionosphere at high latitudes. Consequently, the neutral atmosphere is subject to the dissipation and conversion of this electrical energy to thermal and mechanical energy through Joule heating and Lorentz forcing. As a result of the mechanical energy stored within the neutral wind (caused in part by Lorentz--and pressure gradient--forces set up by the magnetospheric flux of electrical energy), electric currents and fields can be generated in the ionosphere through the neutral wind dynamo mechanism. At high latitudes this source of electrical energy has been largely ignored in past studies, owing to the assumed dominance of the solar wind/magnetospheric dynamo as an electrical energy source to the ionosphere. However, other researchers have demonstrated that the available electrical energy provided by the neutral wind is significant at high latitudes, particularly in the midnight sector of the polar cap and in the region of the magnetospheric convection reversal. As a result, the conclusions of a number of broad ranging high-latitude investigations may be modified if the neutral-wind contribution to high-latitude electrodynamics is properly accounted for. These include the following: studies assessing solar wind-magnetospheric coupling by comparing the cross polar cap potential with solar wind parameters; research based on the alignment of particle precipitation with convection or field aligned current boundaries; and synoptic investigations attributing seasonal variations in the observed electric field and current patterns to external sources. These research topics have been initiated by satellite and ground-based observations and have been attributed to magnetospheric causes. However, the contribution of the neutral wind to the high-latitude electric field and current systems and their seasonal and local time dependence has yet to be quantitatively evaluated. In this program, we are evaluating the coupled magnetospheric and neutral wind dynamos at high latitudes under various conditions. In addition to examining the impact of seasonal variations, we are investigating the consequences of the separate dynamos having pure current-source or voltage-source behaviors.
Experimental Study on New Multi-Column Tension-Leg-Type Floating Wind Turbine
NASA Astrophysics Data System (ADS)
Zhao, Yong-sheng; She, Xiao-he; He, Yan-ping; Yang, Jian-min; Peng, Tao; Kou, Yu-feng
2018-04-01
Deep-water regions often have winds favorable for offshore wind turbines, and floating turbines currently show the greatest potential to exploit such winds. This work established proper scaling laws for model tests, which were then implemented in the construction of a model wind turbine with optimally designed blades. The aerodynamic, hydrodynamic, and elastic characteristics of the proposed new multi-column tension-leg-type floating wind turbine (WindStar TLP system) were explored in the wave tank testing of a 1:50 scale model at the State Key Laboratory of Ocean Engineering at Shanghai Jiao Tong University. Tests were conducted under conditions of still water, white noise waves, irregular waves, and combined wind, wave, and current loads. The results established the natural periods of the motion, damping, motion response amplitude operators, and tendon tensions of the WindStar TLP system under different environmental conditions, and thus could serve as a reference for further research. Key words: floating wind turbine, model test, WindStar TLP, dynamic response
21 CFR 210.1 - Status of current good manufacturing practice regulations.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Status of current good manufacturing practice... SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE IN MANUFACTURING, PROCESSING, PACKING, OR HOLDING OF DRUGS; GENERAL § 210.1 Status of current good manufacturing practice regulations...
Methods and apparatus for twist bend coupled (TCB) wind turbine blades
Moroz, Emilian Mieczyslaw; LeMieux, David Lawrence; Pierce, Kirk Gee
2006-10-10
A method for controlling a wind turbine having twist bend coupled rotor blades on a rotor mechanically coupled to a generator includes determining a speed of a rotor blade tip of the wind turbine, measuring a current twist distribution and current blade loading, and adjusting a torque of a generator to change the speed of the rotor blade tip to thereby increase an energy capture power coefficient of the wind turbine.
NASA Astrophysics Data System (ADS)
Morimoto, Shigeo; Nakamura, Tomohiko; Takeda, Yoji
This paper proposes the sensorless output power maximization control of the wind generation system. A permanent magnet synchronous generator (PMSG) is used as a variable speed generator in the proposed system. The generator torque is suitably controlled according to the generator speed and thus the power from a wind turbine settles down on the maximum power point by the proposed MPPT control method, where the information of wind velocity is not required. Moreover, the maximum available generated power is obtained by the optimum current vector control. The current vector of PMSG is optimally controlled according to the generator speed and the required torque in order to minimize the losses of PMSG considering the voltage and current constraints. The proposed wind power generation system can be achieved without mechanical sensors such as a wind velocity detector and a position sensor. Several experimental results show the effectiveness of the proposed control method.
NASA Astrophysics Data System (ADS)
Liu, Nigang; Su, Zhenpeng; Zheng, Huinan; Wang, Yuming; Wang, Shui
2018-01-01
Magnetosonic waves are highly oblique whistler mode emissions transferring energy from the ring current protons to the radiation belt electrons in the inner magnetosphere. Here we present the first report of prompt disappearance and emergence of magnetosonic waves induced by the solar wind dynamic pressure variations. The solar wind dynamic pressure reduction caused the magnetosphere expansion, adiabatically decelerated the ring current protons for the Bernstein mode instability, and produced the prompt disappearance of magnetosonic waves. On the contrary, because of the adiabatic acceleration of the ring current protons by the solar wind dynamic pressure enhancement, magnetosonic waves emerged suddenly. In the absence of impulsive injections of hot protons, magnetosonic waves were observable even only during the time period with the enhanced solar wind dynamic pressure. Our results demonstrate that the solar wind dynamic pressure is an essential parameter for modeling of magnetosonic waves and their effect on the radiation belt electrons.
Surface Currents and Winds at the Delaware Bay Mouth
DOE Office of Scientific and Technical Information (OSTI.GOV)
Muscarella, P A; Barton, N P; Lipphardt, B L
2011-04-06
Knowledge of the circulation of estuaries and adjacent shelf waters has relied on hydrographic measurements, moorings, and local wind observations usually removed from the region of interest. Although these observations are certainly sufficient to identify major characteristics, they lack both spatial resolution and temporal coverage. High resolution synoptic observations are required to identify important coastal processes at smaller scales. Long observation periods are needed to properly sample low-frequency processes that may also be important. The introduction of high-frequency (HF) radar measurements and regional wind models for coastal studies is changing this situation. Here we analyze synoptic, high-resolution surface winds andmore » currents in the Delaware Bay mouth over an eight-month period (October 2007 through May 2008). The surface currents were measured by two high-frequency radars while the surface winds were extracted from a data-assimilating regional wind model. To illustrate the utility of these monitoring tools we focus on two 45-day periods which previously were shown to present contrasting pictures of the circulation. One, the low-outflow period is from 1 October through 14 November 2007; the other is the high-outflow period from 3 March through 16 April 2008. The large-scale characteristics noted by previous workers are clearly corroborated. Specifically the M2 tide dominates the surface currents, and the Delaware Bay outflow plume is clearly evident in the low frequency currents. Several new aspects of the surface circulation were also identified. These include a map of the spatial variability of the M2 tide (validating an earlier model study), persistent low-frequency cross-mouth flow, and a rapid response of the surface currents to a changing wind field. However, strong wind episodes did not persist long enough to set up a sustained Ekman response.« less
NASA Astrophysics Data System (ADS)
Wang, Dongxiao; Shu, Yeqiang; Xue, Huijie; Hu, Jianyu; Chen, Ju; Zhuang, Wei; Zu, TingTing; Xu, Jindian
2014-04-01
Topographically induced upwelling caused by the interaction between large-scale currents and topography was observed during four cruises in the northern South China Sea (NSCS) when the upwelling favorable wind retreated. Using a high-resolution version of the Princeton Ocean Model, we investigate relative contributions of local wind and topography to the upwelling intensity in the NSCS. The results show that the topographically induced upwelling is sensitive to alongshore large-scale currents, which have an important contribution to the upwelling intensity. The topographically induced upwelling is comparable with the wind-driven upwelling at surface and has a stronger contribution to the upwelling intensity than the local wind does at bottom in the near-shore shelf region. The widened shelf to the southwest of Shanwei and west of the Taiwan Banks intensifies the bottom friction, especially off Shantou, which is a key factor for topographically induced upwelling in terms of bottom Ekman transport and Ekman pumping. The local upwelling favorable wind enhances the bottom friction as well as net onshore transport along the 50 m isobath, whereas it has less influence along the 30 m isobath. This implies the local wind is more important in upwelling intensity in the offshore region than in the nearshore region. The contribution of local upwelling favorable wind on upwelling intensity is comparable with that of topography along the 50 m isobath. The effects of local upwelling favorable wind on upwelling intensity are twofold: on one hand, the wind transports surface warm water offshore, and as a compensation of mass the bottom current transports cold water onshore; on the other hand, the wind enhances the coastal current, and the bottom friction in turn increases the topographically induced upwelling intensity.
Solar wind-magnetosphere coupling during intense magnetic storms (1978-1979)
NASA Technical Reports Server (NTRS)
Gonzalez, Walter D.; Gonzalez, Alicia L. C.; Tsurutani, Bruce T.; Smith, Edward J.; Tang, Frances
1989-01-01
The solar wind-magnetosphere coupling problem during intense magnetic storms was investigated for ten intense magnetic storm events occurring between August 16, 1978 to December 28, 1979. Particular attention was given to the dependence of the ring current energization on the ISEE-measured solar-wind parameters and the evolution of the ring current during the main phase of the intense storms. Several coupling functions were tested as energy input, and several sets of the ring current decay time-constant were searched for the best correlation with the Dst response. Results indicate that a large-scale magnetopause reconnection operates during an intense storm event and that the solar wind ram pressure plays an important role in the energization of the ring current.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Moriarty, Patrick
2016-02-23
The effects of wind turbine wakes within operating wind farms have a substantial impact on the overall energy production from the farm. The current generation of models drastically underpredicts the impact of these wakes leading to non-conservative estimates of energy capture and financial losses to wind farm operators and developers. To improve these models, detailed research of operating wind farms is necessary. Rebecca Barthelmie of Indiana University is a world leader of wind farm wakes effects and would like to partner with NREL to help improve wind farm modeling by gathering additional wind farm data, develop better models and increasemore » collaboration with European researchers working in the same area. This is currently an active area of research at NREL and the capabilities of both parties should mesh nicely.« less
NASA Astrophysics Data System (ADS)
Oh, Ki-Yong; Epureanu, Bogdan I.
2017-10-01
A 1-D phenomenological force model of a Li-ion battery pack is proposed to enhance the control performance of Li-ion battery cells in pack conditions for efficient performance and health management. The force model accounts for multiple swelling sources under the operational environment of electric vehicles to predict swelling-induced forces in pack conditions, i.e. mechanically constrained. The proposed force model not only incorporates structural nonlinearities due to Li-ion intercalation swelling, but also separates the overall range of states of charge into three ranges to account for phase transitions. Moreover, an approach to study cell-to-cell variations in pack conditions is proposed with serial and parallel combinations of linear and nonlinear stiffness, which account for battery cells and other components in the battery pack. The model is shown not only to accurately estimate the reaction force caused by swelling as a function of the state of charge, battery temperature and environmental temperature, but also to account for cell-to-cell variations due to temperature variations, SOC differences, and local degradation in a wide range of operational conditions of electric vehicles. Considering that the force model of Li-ion battery packs can account for many possible situations in actual operation, the proposed approach and model offer potential utility for the enhancement of current battery management systems and power management strategies.
21 CFR 225.1 - Current good manufacturing practice.
Code of Federal Regulations, 2012 CFR
2012-04-01
... Current good manufacturing practice. (a) Section 501(a)(2)(B) of the Federal Food, Drug, and Cosmetic Act... the methods used in, or the facilities or controls used for, its manufacture, processing, packing, or...
21 CFR 225.1 - Current good manufacturing practice.
Code of Federal Regulations, 2014 CFR
2014-04-01
... Current good manufacturing practice. (a) Section 501(a)(2)(B) of the Federal Food, Drug, and Cosmetic Act... the methods used in, or the facilities or controls used for, its manufacture, processing, packing, or...
21 CFR 225.1 - Current good manufacturing practice.
Code of Federal Regulations, 2011 CFR
2011-04-01
... Current good manufacturing practice. (a) Section 501(a)(2)(B) of the Federal Food, Drug, and Cosmetic Act... the methods used in, or the facilities or controls used for, its manufacture, processing, packing, or...
21 CFR 225.1 - Current good manufacturing practice.
Code of Federal Regulations, 2013 CFR
2013-04-01
... Current good manufacturing practice. (a) Section 501(a)(2)(B) of the Federal Food, Drug, and Cosmetic Act... the methods used in, or the facilities or controls used for, its manufacture, processing, packing, or...
Influence of the surface drag coefficient (young waves) on the current structure of the Berre lagoon
NASA Astrophysics Data System (ADS)
Alekseenko, Elena; Roux, Bernard; Kharif, Christian; Sukhinov, Alexander; Kotarba, Richard; Fougere, Dominique; Chen, Paul Gang
2013-04-01
Due to the shallowness, currents and hydrodynamics of Berre lagoon (South of France) are closely conditioned by the bottom topography, and wind affects the entire water column, as for many other Mediterranean lagoons (Perez-Ruzafa, 2011). Wind stress, which is caused by moving atmospheric disturbance, is known to have a major influence in lagoon water circulation. According to the numerical simulation for the main directions of the wind: N-NW, S-SE and W (wind speed of 80 km/h) it is observed that the current is maximal alongshore in the wind direction; the bottom nearshore current being larger in shallower area. This fact is coherent with fundamental principle of wind-driven flows in closed or partially closed basins which states that in shallow water the dominant force balance is between surface wind stress and bottom friction, yielding a current in the direction of the wind (Mathieu et al, 2002, Hunter and Hearn, 1987; Hearn and Hunter,1990). A uniform wind stress applied at the surface of a basin of variable depth sets up a circulation pattern characterized by relatively strong barotropic coastal currents in the direction of the wind, with return flow occurring over the deeper regions (Csanady, 1967; Csanady, 1971). One of the key parameters characterizing the wind stress formulation is a surface drag coefficient (Cds). Thus, an effect of a surface drag coefficient, in the range 0.0016 - 0.0032, will be analyzed in this work. The value of surface drag coefficient Cds = 0.0016 used in our previous studies (Alekseenko et al., 2012), would correspond to mature waves (open sea). But, in the case of semi-closed lagoonal ecosystem, it would be more appropriate to consider "young waves" mechanism. A dependency of this coefficient in terms of the wind speed is given by Young (1999) in both cases of mature waves and young waves. For "young waves" generated at a wind speed of 80 km/h, Cds = 0.0032. So, the influence of Cds on the vertical profile of the velocity in the water column is analyzed in the range 0.0016 - 0.0032. For the three main wind directions considered in this work, for a wind speed of 80 km/h, the complex current structure of the Berre lagoon is analysed. In the nearshore zones, strong alongshore downwind currents are generated, reaching values of the order of 1m/s (up to 1.5 m/s) at the free surface, and 0.5 - 0.6 m/s at the bottom. References Alekseenko E., B. Roux, A. Sukhinov, R. Kotarba, D. Fougere. Coastal hydrodynamics in a windy lagoon; submitted to Computers and Fluids, oct. 2012 Csanady G. T.: Large-scale motion in the Great Lakes, Journal of Geophysical Research, 72(16), 4151-4161, 1967. Csanady G. T. : Baroclinic boundary currents and long edge-waves in basins with sloping shores. J. Physical Oceanography 1(2):92-104, 1971. Hunter, J.R. and Hearn, C.J.: Lateral and vertical variations in the wind-driven circulations in long, shallow lakes, Journal of Geophysical Research, 92 (C12), 1987. Hearn, C.J. and Hunter, J.R.: A note on the equivalence of some two- and three-dimensional models of wind-driven barotropic flow in shallow seas, Applied Mathematical Modelling, 14, 553-556, 1990. Mathieu P.P., Deleersnijder E., Cushman-Roisin B., Beckers J.M. and Bolding K.: The role of topography in small well-mixed bays, with application to the lagoon of Mururoa. Continental Shelf research, 22(9), 1379-1395, 2002. A. Pérez-Ruzafa, C. Marcos, I.M. Pérez-Ruzafa (2011). Mediterranean coastal lagoons in an ecosystem and aquatic resources management context//Physics and Chemistry of the Earth, Parts A/B/C, Volume 36, Issues 5-6, 2011, Pages 160-166 Young I.R., Wind generated ocean waves. Ocean Engineering Series Editors. Elsevier, 1999, ISBN: 0-08-043317-0.
Fujishiro, Kaori; Stukovsky, Karen D Hinckley; Roux, Ana Diez; Landsbergis, Paul; Burchfiel, Cecil
2012-01-01
Objectives This study examines associations of occupation with smoking status, amount smoked among current- and former-smokers (number of cigarettes/day and lifetime cigarette consumption (pack-years)), and workplace exposure to environmental tobacco smoke (ETS) independent from income and education. Methods This is a cross-sectional analysis of data from a community sample (n=6355, age range: 45–84) using logistic and multinomial regression. All analyses were stratified by sex and adjusted for socio-demographic variables. Results Male blue-collar and sales/office workers had higher odds of having consumed >20 pack-years of cigarettes than managers/professionals. For both male and female current- or former-smokers, exposure to workplace ETS was consistently and strongly associated with heavy smoking and greater pack-years. Conclusions Blue-collar workplaces are associated with intense smoking and ETS exposure. Smoking must be addressed at both the individual- and workplace-levels especially in blue-collar workplaces. PMID:22261926
Fujishiro, Kaori; Stukovsky, Karen D Hinckley; Roux, Ana Diez; Landsbergis, Paul; Burchfiel, Cecil
2012-02-01
This study examines associations of occupation with smoking status, amount smoked among current and former smokers (number of cigarettes per day and lifetime cigarette consumption (pack-years)), and workplace exposure to environmental tobacco smoke (ETS) independent from income and education. This is a cross-sectional analysis of data from a community sample (n = 6355, age range: 45-84) using logistic and multinomial regression. All analyses were stratified by sex and adjusted for socio-demographic variables. Male blue-collar and sales/office workers had higher odds of having consumed more than 20 pack-years of cigarettes than managers/professionals. For both male and female current or former smokers, exposure to workplace ETS was consistently and strongly associated with heavy smoking and greater pack-years. Blue-collar workplaces are associated with intense smoking and ETS exposure. Smoking must be addressed at both the individual and workplace levels especially in blue-collar workplaces.
Cigarette pack warning labels in Russia: how graphic should they be?
Wade, Benjamin; Merrill, Ray M; Lindsay, Gordon B
2011-06-01
Tobacco warning labels on cigarette packs have been shown to reduce cigarette consumption. The current study measures the Russian population's acceptance and preference of graphic (picture + text) tobacco warning labels. Nationally representative data were collected from 1778 participants in the Russian Federation in October 2009. A cross-sectional survey was conducted through person-to-person household interviews with respondents aged ≥ 14 years. Survey questions included standard demographic queries and three study-specific questions. Participants rated the strength of 13 cigarette warning labels according to their effectiveness to deter from smoking. Smoking status and the population's acceptance of similar warning labels was also measured. A dose-response pattern is apparent between the degree of graphic content of cigarette warning labels and the public's perception regarding the warning label's ability to discourage smoking. Approximately 87% of all respondents thought Russian authorities should require tobacco manufacturers to place graphic warning labels on cigarette packs, while 80% of current smokers wanted their government to enact such enforcement. The Russian population would strongly support government policy that would require graphic warning labels to be placed on cigarette packs in their country. In order to best deter from smoking, future cigarette warning labels in Russia should be as graphic as possible.
NASA Astrophysics Data System (ADS)
Mahmood, Faleh H.; Kadhim, Hussein T.; Resen, Ali K.; Shaban, Auday H.
2018-05-01
The failure such as air gap weirdness, rubbing, and scrapping between stator and rotor generator arise unavoidably and may cause extremely terrible results for a wind turbine. Therefore, we should pay more attention to detect and identify its cause-bearing failure in wind turbine to improve the operational reliability. The current paper tends to use of power spectral density analysis method of detecting internal race and external race bearing failure in micro wind turbine by estimation stator current signal of the generator. The failure detector method shows that it is well suited and effective for bearing failure detection.
NASA Astrophysics Data System (ADS)
Kubryakov, A. A.; Stanichny, S. V.; Zatsepin, A. G.
2018-03-01
The propagation of the Danube River plume has strong interannual variability that impacts the local balance of nutrients and the thermohaline structure in the western Black Sea. In the present study, we use a particle-tracking model based on satellite altimetry measurements and wind reanalysis data, as well as satellite measurements (SeaWiFS, MODIS), to investigate the interannual variability in the Danube plume pathways during the summer from 1993 to 2015. The wind conditions largely define the variability in the Danube water propagation. Relatively low-frequency variability (on periods of a week to months) in the wind stress curl modulates the intensity of the geostrophic Rim Current and related mesoscale eddy dynamics. High-frequency offshore wind-drift currents transport the plume across isobaths and provide an important transport link between shelf and offshore circulation. Inherent plume dynamics play an additional role in the near-mouth transport of the plume and its connection with offshore circulation. During the years with prevailing northeast winds ( 30% of studied cases), which are usually accompanied by increased wind curl over the Black Sea and higher Danube discharge, an alongshore southward current at the NorthWestern Shelf (NWS) is formed near the western Black Sea coast. Advected southward, the Danube waters are entrained in the Rim Current jet, which transports them along the west coast of the basin. The strong Rim Current, fewer eddies and downwelling winds substantially decrease the cross-shelf exchange of nutrients. During the years with prevailing southeastern winds ( 40%), the Rim Current is less intense. Mesoscale eddies effectively trap the Danube waters, transporting them to the deep western part of the basin. The low- and high-frequency southeastern wind-drift currents contribute significantly to cross-isobath plume transport and its connection with offshore circulation. During several years ( 15%), the Danube waters moved eastward to the west coast of Crimea. They were transported on the north periphery of the mesoscale anticyclones due to prevailing eastward wind-drift currents. During the years with hot summers, a monsoon effect induced the formation of a strong anticyclonic wind cell over the NorthWestern Shelf (NWS), and the plume moved northward ( 15%). Anticyclonic wind circulation leads to the Ekman convergence of brackish surface waters in the centre of the shelf and the formation of a baroclinic geostrophic anticyclone north of the NWS. This anticyclone traps the Danube waters and forces them to remain on the shelf for a long period of time. The impact of the propagation of the plume on the variability in chlorophyll a chlorophyll a in the NWS and the western Black Sea is analysed in this study based on satellite data.
NASA Astrophysics Data System (ADS)
Gutierrez, B. T.; Voulgaris, G.; Work, P. A.; Seim, H.; Warner, J. C.
2004-12-01
Cross-shelf variations of near-bed currents and variations in vertical flow were investigated on the inner shelf of Long Bay, South Carolina during the spring and fall of 2001. Current meters sampled near-bed currents at six locations as well as vertical current profiles at three of the sites. The observations showed that the tides accounted for approximately 45-66% of the flow variability. The dominant tidal component, the semi-diurnal constituent M2, exhibited tidal ellipse orientations that are increasingly aligned with the coast closer to the shore. The largest M2 current magnitudes were identified closest to shore and over the top of a sand shoal located 5.5 km offshore of Myrtle Beach. The remaining flow variability was associated with sub-tidal flows which respond to the passage of low-pressure systems across the region. These weather systems were characterized by periods of southwesterly winds in advance of low-pressure centers followed by northeasterly winds as the systems passed over the study area. When strong southwesterly winds persisted, surface flow was oriented approximately in the direction of the wind. At the same time near-bottom flows were also directed to the northeast in the direction of the wind except during periods of stratification when vertical current profiles suggest near-bed onshore flow. The stratified flows were observed mainly during the spring deployment. For periods of strong northeasterly winds, currents were directed alongshore to the southwest and exhibited little variation throughout the water column. These observations are consistent with recent field and modeling studies for the inner-shelf. Comparison of the near-bed flow measurements during the fall deployment revealed a cross-shore gradient in alongshore flow during periods of strong northeasterly winds. During these episodes flows at the offshore measurement stations were oriented in the direction of the wind, while flows closest to shore occurred in the opposite direction. These observations reveal 1) conditions which contribute to cross-shore transport and 2) the presence of an alongshore flow gradient which may affect sediment transport patterns during certain meteorological conditions.
Assessment of the Economic Potential of Distributed Wind in Colorado, Minnesota, and New York
DOE Office of Scientific and Technical Information (OSTI.GOV)
McCabe, Kevin; Sigrin, Benjamin O.; Lantz, Eric J.
This work seeks to identify current and future spatial distributions of economic potential for behind-the-meter distributed wind, serving primarily rural or suburban homes, farms, and manufacturing facilities in Colorado, Minnesota, and New York. These states were identified by technical experts based on their current favorability for distributed wind deployment. We use NREL's Distributed Wind Market Demand Model (dWind) (Lantz et al. 2017; Sigrin et al. 2016) to identify and rank counties in each of the states by their overall and per capita potential. From this baseline assessment, we also explore how and where improvements in cost, performance, and other marketmore » sensitivities affect distributed wind potential.« less
Liu, Hanhui; Li, Mengping; Kaner, Richard B; Chen, Songyan; Pei, Qibing
2018-05-09
Owing to the need for portable and sustainable energy sources and the development trend for microminiaturization and multifunctionalization in the electronic components, the study of integrated self-charging power packs has attracted increasing attention. A new self-charging power pack consisting of a silicon nanowire array/poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) hybrid solar cell and a laser-scribed graphene (LSG) supercapacitor has been fabricated. The Si nanowire array/PEDOT:PSS hybrid solar cell structure exhibited a high power conversion efficiency (PCE) of 12.37%. The LSG demonstrated excellent energy storage capability for the power pack, with high current density, energy density, and cyclic stability when compared to other supercapacitor electrodes such as active carbon and conducting polymers. The overall efficiency of the power unit is 2.92%.
Fibrous selective emitter structures from sol-gel process
NASA Astrophysics Data System (ADS)
Chen, K. C.
1999-03-01
Selective emitters have the potential benefit of high efficiency due to the matching of emission spectra to the response of photovoltaic (PV) cells. Continuous uniform rare-earth oxide selective emitter fibers were successfully fabricated using a viscous solution made from metal organic precursors. Cylindrical- and planar configuration emitter structures were made by direct cross-winding or stacking of precursor fiber layers. The combustion and optical performance of the planar emitter structures were tested. The results indicates that both the designing of the fiber packing density and the thickness is critical for high photon and power output.
Earth Obsersation taken by the Expedition 11 crew
2005-07-09
ISS011-E-10252 (9 July 2005) --- This easterly-looking image from the International Space Station shows Hurricane Dennis after the storm had already crossed Cuba and was heading for the northern Gulf of Mexico. Dennis was a Category 3 storm, packing winds of 115 miles per hour, at the time of exposure and located approximately 385 miles southeast of Biloxi, Mississippi or 280 miles south of Panama City, Florida. The image was exposed at 22:06:35 (GMT), July 9, 2005. The storm's eye is at frame center. The black triangle in extreme lower left is part of the Space Station's window.
Earth observation taken by the Expedition 28 crew
2011-08-23
ISS028-E-030243 (23 Aug. 2011) --- A digital photo from the International Space Station from Aug. 23, 2011, allows the viewer to look toward the southwest at part of Hurricane Irene churning near the northern Bahamas, including Great Abaco Island (lower right), Andros Island under a thunderstorm (center right) and a ?fair? Cuba from left to right (upper center). The outflow and some of the banding of the northwest side of Irene are visible on the lower left. Meteorologists say Irene probably was centered over Acklins Island packing 120 mile per hour winds when the photo was taken.
Earth observation taken by the Expedition 33 crew
2012-10-29
ISS033-E-016695 (29 Oct. 2012) --- One of the Expedition 33 crew members aboard the International Space Station took this photo of Hurricane Sandy at 16:55:32 GMT on Oct. 29, 2012. East is generally at the top of the photo, south to the right. At the camera time of the photo Sandy was located by the National Hurricane Center at approximately 37.5 degrees north latitude and 71.5 degrees west longitude or 25 miles southeast of Atlantic City, New Jersey moving north-northwest at 18 miles per hour and packing winds of 90 miles per hour.
In situ measurements of wind and current speed and relationship between output power and turbulence
NASA Astrophysics Data System (ADS)
Duran Medina, Olmo; Schmitt, François G.; Sentchev, Alexei; Calif, Rudy
2015-04-01
In a context of energy transition, wind and tidal energy are sources of clean energy with the potential of partially satisfying the growing demand. The main problem of this type of energy, and other types of renewable energy remains the discontinuity of the electric power produced in different scales, inducing large fluctuations also called intermittency. This intermittency of wind and tidal energy is inherent to the turbulent nature of wind and marine currents. We consider this intermittent power production in strong relation with the turbulent intermittency of the resource. The turbulence theory is multifractal energy cascades models, a classic in physics of turbulence. From earlier studies in atmospheric sciences, we learn that wind speed and the aggregate power output are intermittent and multifractal over a wide range of scales [Calif and Schmitt 2014]. We want to extend this study to a marine current turbine and compare the scaling properties for those renewable energy sources. We consider here coupling between simultaneous velocity time series and output power from a wind turbine and a marine current turbine. Wind turbine data were obtained from Denmark and marine current data from Western Scheldt, Belgium where a prototype of a vertical and horizontal marine current turbines are tested. After an estimation of their Fourier density power spectra, we study their scaling properties in Kolmogorov's theory and the framework of fully developed turbulence. Hence, we employ a Hilbert-based methodology, namely arbitrary-order Hilbert spectral analysis [Calif et al. 2013a, 2013b] to characterize the intermittent property of the wind and marine current velocity in order to characterize the intermittent nature of the fluid. This method is used in order to obtain the spectrum and the corresponding power law for non-linear and non-stationary time series. The goal is to study the non-linear transfer characteristics in a multi-scale and multi-intensity framework.
The operational processing of wind estimates from cloud motions: Past, present and future
NASA Technical Reports Server (NTRS)
Novak, C.; Young, M.
1977-01-01
Current NESS winds operations provide approximately 1800 high quality wind estimates per day to about twenty domestic and foreign users. This marked improvement in NESS winds operations was the result of computer techniques development which began in 1969 to streamline and improve operational procedures. In addition, the launch of the SMS-1 satellite in 1974, the first in the second generation of geostationary spacecraft, provided an improved source of visible and infrared scanner data for the extraction of wind estimates. Currently, operational winds processing at NESS is accomplished by the automated and manual analyses of infrared data from two geostationary spacecraft. This system uses data from SMS-2 and GOES-1 to produce wind estimates valid for 00Z, 12Z and 18Z synoptic times.
The most intense current sheets in the high-speed solar wind near 1 AU
NASA Astrophysics Data System (ADS)
Podesta, John J.
2017-03-01
Electric currents in the solar wind plasma are investigated using 92 ms fluxgate magnetometer data acquired in a high-speed stream near 1 AU. The minimum resolvable scale is roughly 0.18 s in the spacecraft frame or, using Taylor's "frozen turbulence" approximation, one proton inertial length di in the plasma frame. A new way of identifying current sheets is developed that utilizes a proxy for the current density J obtained from the derivatives of the three orthogonal components of the observed magnetic field B. The most intense currents are identified as 5σ events, where σ is the standard deviation of the current density. The observed 5σ events are characterized by an average scale size of approximately 3di along the flow direction of the solar wind, a median separation of around 50di or 100di along the flow direction of the solar wind, and a peak current density on the order of 0.5 pA/cm2. The associated current-carrying structures are consistent with current sheets; however, the planar geometry of these structures cannot be confirmed using single-point, single-spacecraft measurements. If Taylor's hypothesis continues to hold for the energetically dominant fluctuations at kinetic scales 1
NASA Astrophysics Data System (ADS)
Bai, Ching-Yuan; Wen, Tse-Min; Hou, Kung-Hsu; Ger, Ming-Der
The low-temperature pack chromization, a reforming pack cementation process, is employed to modify AISI 1045 steel for the application of bipolar plates in PEMFC. The process is conducted to yield a coating, containing major Cr-carbides and minor Cr-nitrides, on the substrate in view of enhancing the steel's corrosion resistance and lowering interfacial contact resistance between the bipolar plate and gas diffusion layer. Electrical discharge machining and rolling approach are used as the pretreatment to produce an activated surface on the steel before pack chromization process to reduce operating temperatures and increase deposition rates. The rolled-chromized steel shows the lowest corrosion current density, 3 × 10 -8 A cm -2, and the smallest interfacial contact resistance, 5.9 mΩ cm 2, at 140 N cm -2 among all tested steels. This study clearly states the performance of 1045 carbon steel modified by activated and low-temperature pack chromization processes, which possess the potential to be bipolar plates in the application of PEMFC.
NASA Astrophysics Data System (ADS)
Shinohara, Katsuji; Shinhatsubo, Kurato; Iimori, Kenichi; Yamamoto, Kichiro; Saruban, Takamichi; Yamaemori, Takahiro
In recent year, consciousness of environmental problems is enhancing, and the price of the electric power purchased by an electric power company is established expensive for the power plant utilizing the natural energy. So, the introduction of the wind power generation is promoted in Japan. Generally, squirrel-cage induction machines are widely used as a generator in wind power generation system because of its small size, lightweight and low-cost. However, the induction machines do not have a source of excitation. Thus, it causes the inrush currents and the instantaneous voltage drop when the generator is directly connected to a power grid. To reduce the inrush currents, an AC power regulator is used. Wind power generations are frequently connected to and disconnected from the power grid. However, when the inrush currents are reduced, harmonic currents are caused by phase control of the AC power regulator. And the phase control of AC power regulator cannot control the power factor. Therefore, we propose the use of the AC power regulator to compensate for the harmonic currents and reactive power in the wind power generation system, and demonstrate the validity of its system by simulated and experimental results.
Balancing Europe's wind power output through spatial deployment informed by weather regimes.
Grams, Christian M; Beerli, Remo; Pfenninger, Stefan; Staffell, Iain; Wernli, Heini
2017-08-01
As wind and solar power provide a growing share of Europe's electricity1, understanding and accommodating their variability on multiple timescales remains a critical problem. On weekly timescales, variability is related to long-lasting weather conditions, called weather regimes2-5, which can cause lulls with a loss of wind power across neighbouring countries6. Here we show that weather regimes provide a meteorological explanation for multi-day fluctuations in Europe's wind power and can help guide new deployment pathways which minimise this variability. Mean generation during different regimes currently ranges from 22 GW to 44 GW and is expected to triple by 2030 with current planning strategies. However, balancing future wind capacity across regions with contrasting inter-regime behaviour - specifically deploying in the Balkans instead of the North Sea - would almost eliminate these output variations, maintain mean generation, and increase fleet-wide minimum output. Solar photovoltaics could balance low-wind regimes locally, but only by expanding current capacity tenfold. New deployment strategies based on an understanding of continent-scale wind patterns and pan-European collaboration could enable a high share of wind energy whilst minimising the negative impacts of output variability.
Measuring ammonia concentrations and emissions from agricultural land and liquid surfaces: a review.
Shah, Sanjay B; Westerman, Philip W; Arogo, Jactone
2006-07-01
Aerial ammonia concentrations (Cg) are measured using acid scrubbers, filter packs, denuders, or optical methods. Using Cg and wind speed or airflow rate, ammonia emission rate or flux can be directly estimated using enclosures or micrometeorological methods. Using nitrogen (N) recovery is not recommended, mainly because the different gaseous N components cannot be separated. Although low cost and replicable, chambers modify environmental conditions and are suitable only for comparing treatments. Wind tunnels do not modify environmental conditions as much as chambers, but they may not be appropriate for determining ammonia fluxes; however, they can be used to compare emissions and test models. Larger wind tunnels that also simulate natural wind profiles may be more useful for comparing treatments than micrometeorological methods because the latter require larger plots and are, thus, difficult to replicate. For determining absolute ammonia flux, the micrometeorological methods are the most suitable because they are nonintrusive. For use with micrometeorological methods, both the passive denuders and optical methods give comparable accuracies, although the latter give real-time Cg but at a higher cost. The passive denuder is wind weighted and also costs less than forced-air Cg measurement methods, but it requires calibration. When ammonia contamination during sample preparation and handling is a concern and separating the gas-phase ammonia and aerosol ammonium is not required, the scrubber is preferred over the passive denuder. The photothermal interferometer, because of its low detection limit and robustness, may hold potential for use in agriculture, but it requires evaluation. With its simpler theoretical basis and fewer restrictions, the integrated horizontal flux (IHF) method is preferable over other micrometeorological methods, particularly for lagoons, where berms and land-lagoon boundaries modify wind flow and flux gradients. With uniform wind flow, the ZINST method requiring measurement at one predetermined height may perform comparably to the IHF method but at a lower cost.
Permanent magnet machine with windings having strand transposition
Qu, Ronghai; Jansen, Patrick Lee
2009-04-21
This document discusses, among other things, a stator with transposition between the windings or coils. The coils are free from transposition to increase the fill factor of the stator slots. The transposition at the end connections between an inner coil and an outer coil provide transposition to reduce circulating current loss. The increased fill factor reduces further current losses. Such a stator is used in a dual rotor, permanent magnet machine, for example, in a compressor pump, wind turbine gearbox, wind turbine rotor.
Numerical simulation of tornado wind loading on structures
NASA Technical Reports Server (NTRS)
Maiden, D. E.
1976-01-01
A numerical simulation of a tornado interacting with a building was undertaken in order to compare the pressures due to a rotational unsteady wind with that due to steady straight winds used in design of nuclear facilities. The numerical simulations were performed on a two-dimensional compressible hydrodynamics code. Calculated pressure profiles for a typical building were then subjected to a tornado wind field and the results were compared with current quasisteady design calculations. The analysis indicates that current design practices are conservative.
Forward and reverse control system for induction motors
Wright, J.T.
1987-09-15
A control system for controlling the direction of rotation of a rotor of an induction motor includes an array of five triacs with one of the triacs applying a current of fixed phase to the windings of the rotor and four of the triacs being switchable to apply either hot ac current or return ac current to the stator windings so as to reverse the phase of current in the stator relative to that of the rotor and thereby reverse the direction of rotation of the rotor. Switching current phase in the stator is accomplished by operating the gates of pairs of the triacs so as to connect either hot ac current or return ac current to the input winding of the stator. 1 fig.
Partitioning and packing mathematical simulation models for calculation on parallel computers
NASA Technical Reports Server (NTRS)
Arpasi, D. J.; Milner, E. J.
1986-01-01
The development of multiprocessor simulations from a serial set of ordinary differential equations describing a physical system is described. Degrees of parallelism (i.e., coupling between the equations) and their impact on parallel processing are discussed. The problem of identifying computational parallelism within sets of closely coupled equations that require the exchange of current values of variables is described. A technique is presented for identifying this parallelism and for partitioning the equations for parallel solution on a multiprocessor. An algorithm which packs the equations into a minimum number of processors is also described. The results of the packing algorithm when applied to a turbojet engine model are presented in terms of processor utilization.
Detection and Modeling of a Meteotsunami in Lake Erie During a High Wind Event on May 27, 2012
NASA Astrophysics Data System (ADS)
Anderson, E. J.; Schwab, D. J.; Lombardy, K. A.; LaPlante, R. E.
2012-12-01
On May 27, 2012, a mesoscale convective system moved southeast across the central basin of Lake Erie (the shallowest of the Great Lakes) causing an increase in surface wind speed from 3 to 15 m/s over a few minutes. Although no significant pressure change was observed during this period (+1 mbar), the storm resulted in 3 reported edge waves on the southern shore (5 minutes apart), with wave heights up to 7 feet (2.13 m). Witnesses along the coast reported that the water receded before the waves hit, the only warning of the impending danger. After impact on the southern shore, several individuals were stranded in the water near Cleveland, Ohio. Fortunately, there were no fatalities or serious injury as a result of the edge waves. The storm event yielded two separate but similar squall line events that impacted the southern shore of Lake Erie several hours apart. The first event had little impact on nearshore conditions, however, the second event (moving south-eastward at 21.1 m/s or 41 knots), resulted in 7 ft waves near Cleveland as reported above. The thunderstorms generated three closely packed outflow boundaries that intersected the southern shore of Lake Erie between 1700 and 1730 UTC. The outflow boundaries were followed by a stronger outflow at 1800 UTC. Radial velocities on the WSR-88D in Cleveland, Ohio indicated the winds were stronger in the second outflow boundary. The radar indicated winds between 20.6 and 24.7 m/s (40 and 48 knots) within 240 meters (800 feet) above ground level. In order to better understand the storm event and the cause of the waves that impacted the southern shore, a three-dimensional hydrodynamic model of Lake Erie has been developed using the Finite Volume Coastal Ocean Model (FVCOM). The model is being developed as part of the Great Lakes Coastal Forecasting (GLCFS), a set of experimental real-time pre-operational hydrodynamic models run at the NOAA Great Lakes Research Laboratory that forecast currents, waves, temperature, and water levels for the Great Lakes and connecting channels. The model is simulated for the storm period on May 27, 2012 to reproduce both the benign and the wave-inducing events using interpolated 6-minute meteorology (wind, pressure, air temperature) from shoreline observations recorded by the National Weather Service. Additional scenarios are carried out to understand the influence of storm speed and direction, wind speed, and pressure change on edge wave production near the southern shore of Lake Erie. Through this study, we hope to fully elucidate the early summer meteotsunami event and build an understanding that will enable the development of a meteotsunami forecasting system for the Great Lakes.
2013-12-18
model simula- tions. Various factors such as winds , river discharges, and detached eddies from the Loop Current can contribute to the generation of...indicate that a large component of transport over the inner shelf is produced by wind (40–48%), with river discharge (28–33%) and Loop Current (LC...eddies (19–33%) accounting for the rest (Oey, 1995). Two seasonal current patterns that depend on wind characteristics are distinguishable over the shelf
Ranney, Leah M.; Lazard, Allison J.; Kim, KyungSu; Queen, Tara L.; Avishai, Aya; Boynton, Marcella H.; Sheeran, Paschal J.; Goldstein, Adam O.
2018-01-01
Introduction Product packaging has long been used by the tobacco industry to target consumers and manipulate product perceptions. This study examines the extent to which cigarillo packaging influences perceptions of product flavor, taste, smell, and appeal. Methods A web-based experiment was conducted among young adults. Participants viewed three randomly selected cigarillo packs, varying on pack flavor descriptor, color, type, branding, and warning—totaling 180 pack images. Mixed-effects models were used to estimate the effect of pack elements on product perceptions. Results A total of 2,664 current, ever, and never little cigar and cigarillo users participated. Cigarillo packs with a flavor descriptor were perceived as having a more favorable taste (β = 0.21, p < .001) and smell (β = 0.14, p < .001) compared to packs with no flavor descriptor. Compared to packs with no color, pink and purple packs were more likely to be perceived as containing a flavor (β = 0.11, p < .001), and were rated more favorably on taste (β = 0.17, p < .001), smell (β = 0.15, p < .001), and appeal (β = 0.16, p < .001). While warnings on packs decreased favorable perceptions of product taste (pictorial: β = -0.07, p = .03) and smell (text-only: β = -0.08, p = .01; pictorial: β = -0.09, p = .007), warnings did not moderate the effects of flavor descriptor or color. Conclusions To our knowledge, this study provides the first quantitative evidence that cigarillo packaging alters consumers’ cognitive responses, and warnings on packs do not suffice to overcome the effects of product packaging. The findings support efforts at federal, state, and local levels to prohibit flavor descriptors and their associated product flavoring in non-cigarette products such as cigarillos, along with new data that supports restrictions on flavor cues and colors. PMID:29672604
Experiment study on an inductive superconducting fault current limiter using no-insulation coils
NASA Astrophysics Data System (ADS)
Qiu, D.; Li, Z. Y.; Gu, F.; Huang, Z.; Zhao, A.; Hu, D.; Wei, B. G.; Huang, H.; Hong, Z.; Ryu, K.; Jin, Z.
2018-03-01
No-insulation (NI) coil made of 2 G high temperature superconducting (HTS) tapes has been widely used in DC magnet due to its excellent performance of engineering current density, thermal stability and mechanical strength. However, there are few AC power device using NI coil at present. In this paper, the NI coil is firstly applied into inductive superconducting fault current limiter (iSFCL). A two-winding structure air-core iSFCL prototype was fabricated, composed of a primary copper winding and a secondary no-insulation winding using 2 G HTS coated conductors. Firstly, in order to testify the feasibility to use NI coil as the secondary winding, the impedance variation of the prototype at different currents and different cycles was tested. The result shows that the impedance increases rapidly with the current rises. Then the iSFCL prototype was tested in a 40 V rms/ 3.3 kA peak short circuit experiment platform, both of the fault current limiting and recovery property of the iSFCL are discussed.
Helicopter-V/STOL dynamic wind and turbulence design methodology
NASA Technical Reports Server (NTRS)
Bailey, J. Earl
1987-01-01
Aircraft and helicopter accidents due to severe dynamic wind and turbulence continue to present challenging design problems. The development of the current set of design analysis tools for a aircraft wind and turbulence design began in the 1940's and 1950's. The areas of helicopter dynamic wind and turbulence modeling and vehicle response to severe dynamic wind inputs (microburst type phenomena) during takeoff and landing remain as major unsolved design problems from a lack of both environmental data and computational methodology. The development of helicopter and V/STOL dynamic wind and turbulence response computation methology is reviewed, the current state of the design art in industry is outlined, and comments on design methodology are made which may serve to improve future flight vehicle design.
NASA Astrophysics Data System (ADS)
Espina, Chad Edward Obedoza
The Wildland Urban-Interface Fire Dynamics Simulator (WFDS) is a computer code that is currently being developed by the National Institute of Standards and Technology (NIST). WFDS has the capability of simulating wildland fire behavior with prescribed elements such vegetative and structural fuel, topography, and weather conditions. In this initial stage of the research, support for the development of WFDS focuses on the evaluation of a wind flow simulation on a very complex, outdoor terrain. This effort is preceded by the fabrication, installation and testing of wind-sensing equipment. Foremost, wind data gathered from different sites using various instruments are compared and evaluated. The data gathered in the Trails community of Rancho Bernardo is then presented and compared to select WFDS simulations. Systems consisting of a wind vane and anemometer are currently installed in the Trails community of Rancho Bernardo. They were installed by Professor Fletcher J. Miller and me using a lift that is attached to a telescoping crane. These instruments will gather the wind data needed to show the behavioral patterns of winds influenced by the topography and obstructions such as trees and houses. They are currently installed on top of light posts. These light posts were picked based on the path of the fire influenced by the Santa Ana winds that ravaged the community in 2007. The data from these instruments were graphically represented using a Matlab code that was developed specifically for the data sets. The Matlab graphing utility plots wind speed and wind direction along with matching polar plots. Other main features also include the ability to set a time range and compare two sites in one plot. There are other wind instruments currently being tested and being analyzed to ensure correct data is being recorded. These instruments will also expand to a wider range the wind data-gathering capabilities vertically. A Sound Detecting and Ranging (SoDAR) unit gathers wind speed and direction from the sound waves, initially emitted by the SoDAR to the atmosphere, that are reflected by the air flow above the unit. Wind data has been compared to the SoDAR unit with data from instruments installed on a meteorological tower operated by the National Oceanic and Atmospheric Administration (NOAA) located in northern California. Two more SoDARs are currently in Texas where initially they were deployed 400 meters apart of each other at an airfield. Also in the same airfield, the wind instrument of an Unmanned Aerial Vehicle (UAV) SuperBat was tested and compared to the SoDARs. Lastly, a self-contained wind instrument (Wind Dart) on a UAV that was developed by the University of Colorado was tested. The instrument was used while attached to the UAV Spectra. A static test was also done in San Diego State University's low speed wind tunnel. The wind data comparison from the SoDAR and meteorological tower in Lodi, California showed close tracking to each other both in wind speed and direction. The comparison of the wind data gathered by the two SoDARs in Texas also showed close tracking to each other. As for the Wind Dart, the data gathered from the instrument and UAV Spectra are not conclusive enough to validate the abilities of the Wind Dart. The experimental procedure in testing the Wind Dart on a moving platform must be further developed. Before the aerial test of the Wind Dart, it was first tested at San Diego State University's low speed tunnel. The detected wind speed by the Wind Dart closely matches the prescribed wind speed of the wind tunnel. The data between the UAV SuperBat and SoDARs showed close tracking. Data collected by the Rancho Bernardo wind instruments shows cyclical wind patterns in the neighborhood. Initial evaluation of select WFDS simulations show data that mimics data gathered from the field.
Detection of oppositely directed reconnection jets in a solar wind current sheet
NASA Astrophysics Data System (ADS)
Davis, M. S.; Phan, T. D.; Gosling, J. T.; Skoug, R. M.
2006-10-01
We report the first two-spacecraft (Wind and ACE) detection of oppositely directed plasma jets within a bifurcated current sheet in the solar wind. The event occurred on January 3, 2003 and provides further direct evidence that such jets result from reconnection. The magnetic shear across the bifurcated current sheet at both Wind and ACE was ~150°, indicating that the magnetic shear must have been the same at the reconnection site located between the two spacecraft. These observations thus provide strong evidence for component merging with a guide field ~ 30% of the antiparallel field. The dimensionless reconnection rate based on the measured inflow was 0.03, implying fast reconnection.
Detection of oppositely directed reconnection jets in a solar wind current sheet
NASA Astrophysics Data System (ADS)
Davis, M. S.; Phan, T. D.; Gosling, J. T.; Skoug, R. M.
2006-12-01
We report the first two-spacecraft (Wind and ACE) detection of oppositely directed plasma jets within a bifurcated current sheet in the solar wind. The event occurred on January 3, 2003 and provides further direct evidence that such jets result from reconnection. The magnetic shear across the bifurcated current sheet at both Wind and ACE was approximately 150 degrees, indicating that the magnetic shear must have been the same at the reconnection site located between the two spacecraft. These observations thus provide strong evidence for component merging with a guide field approximately 30% of the antiparallel field. The dimensionless reconnection rate based on the measured inflow was 0.03, implying fast reconnection.
Analysis of Ideal Towers for Tall Wind Applications
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dykes, Katherine L; Damiani, Rick R; Roberts, Joseph O
Innovation in wind turbine tower design is of significant interest for future development of wind power plants. First, wind turbine towers account for a large portion of overall capital expenditures for wind power projects. Second, for low wind-resource regions of the world, the use of low-cost tall-tower technology has the potential to open new markets for development. This study investigates the relative potential of various tower configurations in terms of mass and cost. For different market applications and hub heights, idealized tall towers are designed and compared. The results show that innovation in wind turbine controls makes reaching higher hubmore » heights with current technology economically viable. At the same time, new technologies hold promise for reducing tower costs as these technologies mature and hub heights reach twice the current average.« less
Analysis of Ideal Towers for Tall Wind Applications: Preprint
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dykes, Katherine L; Damiani, Rick R; Roberts, Joseph O
Innovation in wind turbine tower design is of significant interest for future development of wind power plants. First, wind turbine towers account for a large portion of overall capital expenditures for wind power projects. Second, for low wind-resource regions of the world, the use of low-cost tall-tower technology has the potential to open new markets for development. This study investigates the relative potential of various tower configurations in terms of mass and cost. For different market applications and hub heights, idealized tall towers are designed and compared. The results show that innovation in wind turbine controls makes reaching higher hubmore » heights with current technology economically viable. At the same time, new technologies hold promise for reducing tower costs as these technologies mature and hub heights reach twice the current average.« less
Wind turbines for electric utilities: Development status and economics
NASA Technical Reports Server (NTRS)
Ramler, J. R.; Donovan, R. M.
1979-01-01
The technology and economics of the large, horizontal-axis wind turbines currently in the Federal Wind Energy Program are presented. Wind turbine technology advancements made in the last several years are discussed. It is shown that, based on current projections of the costs of these machines when produced in quantity, they should be attractive for utility application. The cost of electricity (COE) produced at the busbar is shown to be a strong function of the mean wind speed at the installation site. The breakeven COE as a fuel saver is discussed and the COE range that would be generally attractive to utilities is indicated.
Wind turbines for electric utilities - Development status and economics
NASA Technical Reports Server (NTRS)
Ramler, J. R.; Donovan, R. M.
1979-01-01
The technology and economics of the large, horizontal-axis wind turbines currently in the Federal Wind Energy Program are presented. Wind turbine technology advancements made in the last several years are discussed. It is shown that, based on current projections of the costs of these machines when produced in quantity, they should be attractive for utility application. The cost of electricity (COE) produced at the busbar is shown to be a strong function of the mean wind speed at the installation site. The breakeven COE as a 'fuel saver' is discussed and the COE range that would be generally attractive to utilities is indicated.
Electrolytic ammonia removal and current efficiency by a vermiculite-packed electrochemical reactor
Li, Liang; Yao, Ji; Fang, Xueyou; Huang, Yuanxing; Mu, Yan
2017-01-01
The ammonia removal as well as the current efficiency during electrolysis was investigated by using a vermiculite-packed electrochemical reactor under continuous mode. Experimental results showed that adsorption of ammonia by vermiculite and electrolytic desorption of ammonia simultaneously existed in the reactor, leading to 89% removal of initial 30 mg N/L ammonia and current efficiency of 25% under the condition of 2.0 A, 6.0 min hydraulic retention time with 300 mg Cl/L chloride as the catalyst. The ammonia removal capacity had a linear relationship with the products of hydraulic retention time, current and chloride concentration within experimental conditions. The treatment results of secondary effluent indicated that 29.9 mg N/L ammonia can be reduced to 4.6 mg N/L with 72% removal of total nitrogen and a current efficiency of 23%, which was 2% less than synthetic wastewater due to the reducing components in the real wastewater. PMID:28102340
NASA Astrophysics Data System (ADS)
Yucel, M.; Sueishi, T.; Inagaki, A.; Kanda, M.
2017-12-01
`Great Garuda' project is an eagle-shaped offshore structure with 17 artificial islands. This project has been designed for the coastal protection and land reclamation of Jakarta due to catastrophic flooding in the city. It offers an urban generation for 300.000 inhabitants and 600.000 workers in addition to its water safety goal. A broad coalition of Indonesian scientists has criticized the project for being negative impacts on the surrounding environment. Despite the vast research by Indonesian scientist on maritime environment, studies on wind and thermal environment over built-up area are still lacking. However, the construction of the various islands off the coast may result changes in wind patterns and thermal environment due to the alteration of the coastline and urbanization in the Jakarta Bay. Therefore, it is important to understand the airflow within the urban canopy in case of unpredictable gust events. These gust events may occur through the closely-packed high-rise buildings and pedestrians may be harmed from such gusts. Accordingly, we used numerical simulations to investigate the impact of the sea wall and the artificial islands over built-up area and, the intensity of wind gusts at the pedestrian level. Considering the fact that the size of turbulence organized structure sufficiently large computational domain is required. Therefore, a 19.2km×4.8km×1.0 km simulation domain with 2-m resolution in all directions was created to explicitly resolve the detailed shapes of buildings and the flow at the pedestrian level. This complex computation was accomplished by implementing a large-eddy simulation (LES) model. Two case studies were conducted considering the effect of realistic surface roughness and upward heat flux. Case_1 was conducted based on the current built environment and Case_2 for investigating the effect of the project on the chosen coastal region of the city. Fig.1 illustrates the schematic of the large-eddy simulation domains of two cases with and without Great Garuda Sea Wall and 17 artificial islands. 3D model of Great Garuda is shown in Fig.2. In addition to the cases mentioned above, the simulation will be generated assigning more realistic heat flux outputs from energy balance model and, inflow boundary conditions coupling with mesoscale model (Weather Research and Forecast model).
Automating the packing heuristic design process with genetic programming.
Burke, Edmund K; Hyde, Matthew R; Kendall, Graham; Woodward, John
2012-01-01
The literature shows that one-, two-, and three-dimensional bin packing and knapsack packing are difficult problems in operational research. Many techniques, including exact, heuristic, and metaheuristic approaches, have been investigated to solve these problems and it is often not clear which method to use when presented with a new instance. This paper presents an approach which is motivated by the goal of building computer systems which can design heuristic methods. The overall aim is to explore the possibilities for automating the heuristic design process. We present a genetic programming system to automatically generate a good quality heuristic for each instance. It is not necessary to change the methodology depending on the problem type (one-, two-, or three-dimensional knapsack and bin packing problems), and it therefore has a level of generality unmatched by other systems in the literature. We carry out an extensive suite of experiments and compare with the best human designed heuristics in the literature. Note that our heuristic design methodology uses the same parameters for all the experiments. The contribution of this paper is to present a more general packing methodology than those currently available, and to show that, by using this methodology, it is possible for a computer system to design heuristics which are competitive with the human designed heuristics from the literature. This represents the first packing algorithm in the literature able to claim human competitive results in such a wide variety of packing domains.
Greenland Sea Odden sea ice feature: Intra-annual and interannual variability
Shuchman, R.A.; Josberger, E.G.; Russel, C.A.; Fischer, K.W.; Johannessen, O.M.; Johannessen, J.; Gloersen, P.
1998-01-01
The "Odden" is a large sea ice feature that forms in the east Greenland Sea that may protrude eastward to 5??E from the main sea ice pack (at about 8??W) between 73?? and 77??N. It generally forms at the beginning of the winter season and can cover 300,000 km2. Throughout the winter the outer edge of the Odden may advance and retreat by several hundred kilometers on timescales of a few days to weeks. Satellite passive microwave observations from 1978 through 1995 provide a continuous record of the spatial and temporal variations of this extremely dynamic phenomenon. Aircraft synthetic aperture radar, satellite passive microwave, and ship observations in the Odden show that the Odden consists of new ice types, rather than older ice types advected eastward from the main pack. The 17-year record shows both strong interannual and intra-annual variations in Odden extent and temporal behavior. For example, in 1983 the Odden was weak, in 1984 the Odden did not occur, and in 1985 the Odden returned late in the season. An analysis of the ice area and extent time series derived from the satellite passive microwave observations along with meteorological data from the International Arctic Buoy Program (IABP) determined the meteorological forcing associated with Odden growth, maintenance, and decay. The key meteorological parameters that are related to the rapid ice formation and decay associated with the Odden are, in order of importance, air temperature, wind speed, and wind direction. Oceanographic parameters must play an important role in controlling Odden formation, but it is not yet possible to quantify this role because of a lack of long-term oceanographic observations. Copyright 1998 by the American Geophysical Union.
Taylor dispersion in wind-driven current
NASA Astrophysics Data System (ADS)
Li, Gang; Wang, Ping; Jiang, Wei-Quan; Zeng, Li; Li, Zhi; Chen, G. Q.
2017-12-01
Taylor dispersion associated with wind-driven currents in channels, shallow lakes and estuaries is essential to hydrological environmental management. For solute dispersion in a wind-driven current, presented in this paper is an analytical study of the evolution of concentration distribution. The concentration moments are intensively derived for an accurate presentation of the mean concentration distribution, up to the effect of kurtosis. The vertical divergence of concentration is then deduced by Gill's method of series expansion up to the fourth order. Based on the temporal evolution of the vertical concentration distribution, the dispersion process in the wind-driven current is concretely characterized. The uniform shear leads to a special symmetrical distribution of mean concentration free of skewness. The non-uniformity of vertical concentration is caused by convection and smeared out gradually by the effect of diffusion, but fails to disappear even at large times.
Control System for Bearingless Motor-generator
NASA Technical Reports Server (NTRS)
Kascak, Peter E. (Inventor); Jansen, Ralph H. (Inventor); Dever, Timothy P. (Inventor)
2008-01-01
A control system for an electromagnetic rotary drive for bearingless motor-generators comprises a winding configuration comprising a plurality of individual pole pairs through which phase current flows, each phase current producing both a lateral force and a torque. A motor-generator comprises a stator, a rotor supported for movement relative to the stator, and a control system. The motor-generator comprises a winding configuration supported by the stator. The winding configuration comprises at least three pole pairs through which phase current flows resulting in three three-phase systems. Each phase system has a first rotor reference frame axis current that produces a levitating force with no average torque and a second rotor reference frame axis current that produces torque.
High beta plasma operation in a toroidal plasma producing device
Clarke, John F.
1978-01-01
A high beta plasma is produced in a plasma producing device of toroidal configuration by ohmic heating and auxiliary heating. The plasma pressure is continuously monitored and used in a control system to program the current in the poloidal field windings. Throughout the heating process, magnetic flux is conserved inside the plasma and the distortion of the flux surfaces drives a current in the plasma. As a consequence, the total current increases and the poloidal field windings are driven with an equal and opposing increasing current. The spatial distribution of the current in the poloidal field windings is determined by the plasma pressure. Plasma equilibrium is maintained thereby, and high temperature, high beta operation results.
Control system for bearingless motor-generator
NASA Technical Reports Server (NTRS)
Jansen, Ralph H. (Inventor); Dever, Timothy P. (Inventor); Kascak, Peter E. (Inventor)
2010-01-01
A control system for an electromagnetic rotary drive for bearingless motor-generators comprises a winding configuration comprising a plurality of individual pole pairs through which phase current flows, each phase current producing both a lateral force and a torque. A motor-generator comprises a stator, a rotor supported for movement relative to the stator, and a control system. The motor-generator comprises a winding configuration supported by the stator. The winding configuration comprises at least three pole pairs through which phase current flows resulting in three three-phase systems. Each phase system has a first rotor reference frame axis current that produces a levitating force with no average torque and a second rotor reference frame axis current that produces torque.
Current and Future Opportunities for Wind Power in the Southeast
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tinnesand, Heidi; Roberts, Owen; Lantz, Eric
This presentation discusses future wind opportunities in the Southeast including factors such as changes in wind turbine technology, historical innovation trends, and forecast demand growth among regions. The presentation covers the current status of wind in the United States at 80-m hub height and the near-future outlook with a hub height at 110 to 140 meters. Future cost reductions in 2030 and beyond are also explored. Heidi Tinnesand presented this information to a utility advisory group meeting in Charlotte, North Carolina, on October 5, 2016.
How Well Does the S-Web Theory Predict In-Situ Observations of the Slow Solar Wind?
NASA Astrophysics Data System (ADS)
Young, A. K.; Antiochos, S. K.; Linker, J.; Zurbuchen, T.
2014-12-01
The S-Web theory provides a physical explanation for the origin and properties of the slow solar wind, particularly its composition. The theory proposes that magnetic reconnection along topologically complex boundaries between open and closed magnetic fields on the sun releases plasma from closed magnetic field regions into the solar wind at latitudes away from the heliospheric current sheet. Such a wind would have elevated charge states compared to the fast wind and an elemental composition resembling the closed-field corona. This theory is currently being tested using time-dependent, high-resolution, MHD simulations, however comparisons to in-situ observations play an essential role in testing and understanding slow-wind release mechanisms. In order to determine the relationship between S-Web signatures and the observed, slow solar wind, we compare plasma data from the ACE and Ulysses spacecraft to solutions from the steady-state models created at Predictive Science, Inc., which use observed magnetic field distributions on the sun as a lower boundary condition. We discuss the S-Web theory in light of our results and the significance of the S-Web for interpreting current and future solar wind observations. This work was supported, in part, by the NASA TR&T and SR&T programs.
NASA Astrophysics Data System (ADS)
Patteson, R. N.
2017-12-01
Mixing mechanisms of the Arctic Ocean have profound impacts on sea ice, global ocean dynamics, and arctic communities. This project used a two-year long time series of ocean current velocities collected from eight moorings located on the Eurasian basin, as well as ERA-interim wind data, to compare and assess relationships between current and wind velocities at different depths. Determining the strength of these correlations will further scientific understanding of the degree to which wind influences mixing, with implications for heat flux, diffusion, and sea ice changes. Using statistical analysis, I calculated whether a significant relationship between wind velocity and ocean currents existed beginning at the surface level ( 50m) .The final correlation values, ranging from R = 0.11 to R = 0.28, indicated a weak relationship between wind velocity and ocean currents at the surface for all eight mooring sites. The results for the surface depth imply that correlation likely decreases with increasing depths, and thus further testing of deeper depth levels was unnecessary. This finding suggests that there is another dominant factor at play in the ocean; we postulate that topography exerts a significant influence on subsurface mixing. This study highlights the need for further research of the different mechanisms and their importance in influencing the dynamic structure of the ocean.
NASA Technical Reports Server (NTRS)
Motil, Brian J.; Green, R. D.; Nahra, H. K.; Sridhar, K. R.
2000-01-01
For long-duration space missions, the life support and In-Situ Resource Utilization (ISRU) systems necessary to lower the mass and volume of consumables carried from Earth will require more sophisticated chemical processing technologies involving gas-liquid two-phase flows. This paper discusses some preliminary two-phase flow work in packed columns and generation of bubbly suspensions, two types of flow systems that can exist in a number of chemical processing devices. The experimental hardware for a co-current flow, packed column operated in two ground-based low gravity facilities (two-second drop tower and KC- 135 low-gravity aircraft) is described. The preliminary results of this experimental work are discussed. The flow regimes observed and the conditions under which these flow regimes occur are compared with the available co-current packed column experimental work performed in normal gravity. For bubbly suspensions, the experimental hardware for generation of uniformly sized bubbles in Couette flow in microgravity conditions is described. Experimental work was performed on a number of bubbler designs, and the capillary bubble tube was found to produce the most consistent size bubbles. Low air flow rates and low Couette flow produce consistent 2-3 mm bubbles, the size of interest for the "Behavior of Rapidly Sheared Bubbly Suspension" flight experiment. Finally the mass transfer implications of these two-phase flows is qualitatively discussed.
Power flow control using distributed saturable reactors
Dimitrovski, Aleksandar D.
2016-02-13
A magnetic amplifier includes a saturable core having a plurality of legs. Control windings wound around separate legs are spaced apart from each other and connected in series in an anti-symmetric relation. The control windings are configured in such a way that a biasing magnetic flux arising from a control current flowing through one of the plurality of control windings is substantially equal to the biasing magnetic flux flowing into a second of the plurality of control windings. The flow of the control current through each of the plurality of control windings changes the reactance of the saturable core reactor by driving those portions of the saturable core that convey the biasing magnetic flux in the saturable core into saturation. The phasing of the control winding limits a voltage induced in the plurality of control windings caused by a magnetic flux passing around a portion of the saturable core.
The effect of cool water pack preparation on vaccine vial temperatures in refrigerators.
Goldwood, Geneva; Diesburg, Steven
2018-01-02
Cool water packs are a useful alternative to ice packs for preventing unintentional freezing of vaccines during outreach in some situations. Current guidelines recommend the use of a separate refrigerator for cooling water packs from ambient temperatures to prevent possible heat degradation of adjacent vaccine vials. To investigate whether this additional equipment is necessary, we measured the temperatures that vaccine vials were exposed to when warm water packs were placed next to vials in a refrigerator. We then calculated the effect of repeated vial exposure to those temperatures on vaccine vial monitor status to estimate the impact to the vaccine. Vials were tested in a variety of configurations, varying the number and locations of vials and water packs in the refrigerator. The calculated average percentage life lost during a month of repeated warming ranged from 20.0% to 30.3% for a category 2 (least stable) vaccine vial monitor and from 3.8% to 6.0% for a category 7 (moderate stability) vaccine vial monitor, compared to 17.0% for category 2 vaccine vial monitors and 3.1% for category 7 vaccine vial monitors at a constant 5 °C. The number of vials, number of water packs, and locations of each impacted vial warming and therefore percentage life lost, but the vaccine vial monitor category had a higher impact on the average percentage life lost than any of the other parameters. The results suggest that damage to vaccines from repeated warming over the course of a month is not certain and that cooling water packs in a refrigerator where vaccines are being stored may be a useful practice if safe procedures are established. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.
NASA Astrophysics Data System (ADS)
Singh, Pritpal; Vinjamuri, Ramana; Wang, Xiquan; Reisner, David
A fuzzy logic-based state-of-charge meter is being developed for Li-ion batteries for potential use in portable defibrillators. ac impedance and voltage recovery measurements have been made which are used as the input parameters for the fuzzy logic model. The load profile for the Li-ion battery packs comprises a continuous 1.4 A constant current discharge periodically interrupted by 10 A pulses. As the battery is cycled the available capacity diminishes and so the number of 10 A pulses that may be delivered decreases. Measurements are being made on a total of three battery packs at three different temperatures (0, 20 and 40 °C) and as expected the number of pulses deliverable by the battery pack diminishes as temperature is decreased. For example, at room temperature the battery pack was initially able to deliver 42 pulses early in the cycle life whereas at 0 °C the battery-pack is only able to initially deliver 12 pulses. The voltage recovery profile upon removal of the 10 A load has been used both in the time domain and frequency domain to develop fuzzy logic models to estimate the number of remaining pulses that the battery-pack can deliver. Accurate models are being developed to estimate the number of pulses that the battery pack can deliver at various stages of its cycle life and at the different temperatures. With sufficient data collected for the battery packs at room temperature accurate fuzzy logic models have been developed for estimation of state-of-charge and implemented in the Motorola MC 68HC12 microcontroller.
Babineau, Kate; Clancy, Luke
2015-01-01
Objectives To measure young people's perceptions of tobacco packaging according to two current pieces of legislation: The EU Tobacco Products Directive (TPD) and Ireland's Public Health (Standardisation of Tobacco Products) Act. Design Within-subject experimental cross-sectional survey of a representative sample of secondary school students. School-based pen and paper survey. Setting 27 secondary schools across Ireland, randomly stratified for size, geographic location, gender, religious affiliation and school-level socioeconomic status. Data were collected between March and May 2014. Participants 1378 fifth year secondary school students aged 16–17 in Ireland. Main outcome measures Young people's perceptions of attractiveness, health risk and smoker characteristics of packs according to EU and Irish branding and packaging guidelines. Results Packs with more branding elements were thought to be healthier than standardised packs for Silk Cut (χ2=158.58, p<0.001), Marlboro (χ2=113.65, p<0.001), and Benson and Hedges (χ2=137.95, p<0.001) brands. Generalized estimating equation binary regressions found that gender was a significant predictor of pack attractiveness for Silk Cut, with females being more likely to find the EU packs attractive (β=−0.45, p=0.007). Gender was a significant predictor for females with regards to the perceived popularity of the Silk Cut brand (β=−0.37, p=0.03). Conclusions The removal of brand identifiers, including colour, font and embossing, reduces the perceived appeal of cigarette packs for young people across all three tested brands. Packs standardised according to Irish legislation are perceived as less attractive, less healthy and smoked by less popular people than packs which conform to the EU TPD 2014 guidelines. PMID:26048206
NASA Astrophysics Data System (ADS)
Shiangjen, Kanokwatt; Chaijaruwanich, Jeerayut; Srisujjalertwaja, Wijak; Unachak, Prakarn; Somhom, Samerkae
2018-02-01
This article presents an efficient heuristic placement algorithm, namely, a bidirectional heuristic placement, for solving the two-dimensional rectangular knapsack packing problem. The heuristic demonstrates ways to maximize space utilization by fitting the appropriate rectangle from both sides of the wall of the current residual space layer by layer. The iterative local search along with a shift strategy is developed and applied to the heuristic to balance the exploitation and exploration tasks in the solution space without the tuning of any parameters. The experimental results on many scales of packing problems show that this approach can produce high-quality solutions for most of the benchmark datasets, especially for large-scale problems, within a reasonable duration of computational time.
NASA Technical Reports Server (NTRS)
1982-01-01
Power Pack II provides an economical means of moving a power source into remote roadless forest areas. It was developed by Prof. Miles and his associates, working in cooperation with the University of California's Department of Forestry. The team combined its own design of an all-terrain vehicle with a suspension system based on the NASA load equalization technology. Result is an intermediate-sized unit which carries a power source and the powered tools to perform a variety of forest management tasks which cannot be done economically with current equipment. Power Pack II can traverse very rough terrain and climb a 60 degree slope; any one of the wheels can move easily over an obstacle larger than itself. Work is being done on a more advanced Power Pack III.
Wave effects on ocean-ice interaction in the marginal ice zone
NASA Technical Reports Server (NTRS)
Liu, Antony K.; Hakkinen, Sirpa; Peng, Chih Y.
1993-01-01
The effects of wave train on ice-ocean interaction in the marginal ice zone are studied through numerical modeling. A coupled two-dimensional ice-ocean model has been developed to include wave effects and wind stress for the predictions of ice edge dynamics. The sea ice model is coupled to the reduced-gravity ocean model through interfacial stresses. The main dynamic balance in the ice momentum is between water-ice stress, wind stress, and wave radiation stresses. By considering the exchange of momentum between waves and ice pack through radiation stress for decaying waves, a parametric study of the effects of wave stress and wind stress on ice edge dynamics has been performed. The numerical results show significant effects from wave action. The ice edge is sharper, and ice edge meanders form in the marginal ice zone owing to forcing by wave action and refraction of swell system after a couple of days. Upwelling at the ice edge and eddy formation can be enhanced by the nonlinear effects of wave action; wave action sharpens the ice edge and can produce ice meandering, which enhances local Ekman pumping and pycnocline anomalies. The resulting ice concentration, pycnocline changes, and flow velocity field are shown to be consistent with previous observations.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-20
... ``cut'' from a sheet or roll of labels--is used. Persistent problems with drug product mislabeling and... believe that development and use of advanced code scanning equipment has made many current electronic... and other advanced scanning techniques have made current electronic systems reliable to the 100...
A U.S. Wind Climatology: new tools to monitor wind trends across the contiguous United States
NASA Astrophysics Data System (ADS)
Crouch, J.; Wallis, T. W.; Arndt, D.
2010-12-01
NOAA’s National Climatic Data Center has developed a new monthly and seasonal product to provide a spatially continuous wind climatology for the contiguous U.S. using NCEP reanalysis data. Surface wind observations are sparse over specific regions of the country, and are subject to many local effects. By utilizing the sigma .995 level of the reanalysis data we can monitor wind conditions and trends of the lower troposphere across the entire U.S. The wind data are interpolated from a 2.5 x 2.5 degree grid to 0.25 degrees to provide additional detail. Data are analyzed from January 1950 to the most current month. Monthly averaged winds and wind anomalies are calculated with respect to the 1971-2000 base period, and time series for each grid point show how regional winds have changed over the 60 year period of record. The goal of this new climatology product is to provide regional decision support for the emerging wind energy sector, in addition to others who are interested in the current state of wind conditions. The U.S. Department of Energy has outlined a plan for 20 percent of U.S. electricity production to be from wind by 2030, and having a temporally and spatially continuous wind dataset, updated on a monthly basis, will be beneficial to understanding wind trends nationwide.
NASA Astrophysics Data System (ADS)
Bakhoday-Paskyabi, Mostafa; Fer, Ilker; Reuder, Joachim
2018-01-01
We report concurrent measurements of ocean currents and turbulence at two sites in the North Sea, one site at upwind of the FINO1 platform and the other 200-m downwind of the Alpha Ventus wind farm. At each site, mean currents, Reynolds stresses, turbulence intensity and production of turbulent kinetic energy are obtained from two bottom-mounted 5-beam Nortek Signature1000s, high-frequency Doppler current profiler, at a water depth of approximately 30 m. Measurements from the two sites are compared to statistically identify the effects of wind farm and waves on ocean current variability and the turbulent structure in the water column. Profiles of Reynolds stresses are found to be sensible to both environmental forcing and the wind farm wake-induced distortions in both boundary layers near the surface and the seabed. Production of turbulent kinetic energy and turbulence intensity exhibit approximately similar, but less pronounced, patterns in the presence of farm wake effects.
Rossi, Michael R.; Tanaka, Daigo; Shimada, Kenji; Rabin, Yoed
2009-01-01
The current study focuses on experimentally validating a planning scheme based on the so-called bubble-packing method. This study is a part of an ongoing effort to develop computerized planning tools for cryosurgery, where bubble packing has been previously developed as a means to find an initial, uniform distribution of cryoprobes within a given domain; the so-called force-field analogy was then used to move cryoprobes to their optimum layout. However, due to the high quality of the cryoprobes’ distribution, suggested by bubble packing and its low computational cost, it has been argued that a planning scheme based solely on bubble packing may be more clinically relevant. To test this argument, an experimental validation is performed on a simulated cross-section of the prostate, using gelatin solution as a phantom material, proprietary liquid-nitrogen based cryoprobes, and a cryoheater to simulate urethral warming. Experimental results are compared with numerically simulated temperature histories resulting from planning. Results indicate an average disagreement of 0.8 mm in identifying the freezing front location, which is an acceptable level of uncertainty in the context of prostate cryosurgery imaging. PMID:19885373
Prognostics and Health Management of Wind Turbines: Current Status and Future Opportunities
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sheng, Shuangwen
This presentation was given at the 2016 Annual Conference of the Prognostics and Health Management Society. It covers the current status and challenges and opportunities of prognostics and health management of wind turbines.
Controllable Fabrication of Non-Close-Packed Colloidal Nanoparticle Arrays by Ion Beam Etching
NASA Astrophysics Data System (ADS)
Yang, Jie; Zhang, Mingling; Lan, Xu; Weng, Xiaokang; Shu, Qijiang; Wang, Rongfei; Qiu, Feng; Wang, Chong; Yang, Yu
2018-06-01
Polystyrene (PS) nanoparticle films with non-close-packed arrays were prepared by using ion beam etching technology. The effects of etching time, beam current, and voltage on the size reduction of PS particles were well investigated. A slow etching rate, about 9.2 nm/min, is obtained for the nanospheres with the diameter of 100 nm. The rate does not maintain constant with increasing the etching time. This may result from the thermal energy accumulated gradually in a long-time bombardment of ion beam. The etching rate increases nonlinearly with the increase of beam current, while it increases firstly then reach its saturation with the increase of beam voltage. The diameter of PS nanoparticles can be controlled in the range from 34 to 88 nm. Based on the non-close-packed arrays of PS nanoparticles, the ordered silicon (Si) nanopillars with their average diameter of 54 nm are fabricated by employing metal-assisted chemical etching technique. Our results pave an effective way to fabricate the ordered nanostructures with the size less than 100 nm.
Spindt cold cathode electron gun development program
NASA Technical Reports Server (NTRS)
Spindt, C. A.
1983-01-01
A thin film field emission cathode array and an electron gun based on this emitter array are summarized. Fabricating state of the art cathodes for testing at NASA and NRL, advancing the fabrication technology, developing wedge shaped emitters, and performing emission tests are covered. An anistropic dry etching process (reactive ion beam etching) developed that leads to increasing the packing density of the emitter tips to about 5 x 10 to the 6th power/square cm. Tests with small arrays of emitter tips having about 10 tips has demonstrated current densities of over 100 A/sq cm. Several times using cathodes having a packing density of 1.25 x 10 to the 6th power tips/sq cm. Indications are that the higher packing density achievable with the dry etch process may extend this capability to the 500 A/sq cm range and beyond. The wedge emitter geometry was developed and shown to produce emission. This geometry can (in principle) extend the current density capability of the cathodes beyond the 500 A/sq cm level. An emission microscope was built and tested for use with the cathodes.
Yamabayashi, Tsutomu; Katoh, Keiichi; Breedlove, Brian K; Yamashita, Masahiro
2017-06-15
Single-molecule magnet (SMM) properties of crystals of a terbium(III)-phthalocyaninato double-decker complex with different molecular packings ( 1 : TbPc₂, 2 : TbPc₂·CH₂Cl₂) were studied to elucidate the relationship between the molecular packing and SMM properties. From single crystal X-ray analyses, the high symmetry of the coordination environment of 2 suggested that the SMM properties were improved. Furthermore, the shorter intermolecular Tb-Tb distance and relative collinear alignment of the magnetic dipole in 2 indicated that the magnetic dipole-dipole interactions were stronger than those in 1 . This was confirmed by using direct current magnetic measurements. From alternating current magnetic measurements, the activation energy for spin reversal for 1 and 2 were similar. However, the relaxation time for 2 is three orders of magnitude slower than that for 1 in the low- T region due to effective suppression of the quantum tunneling of the magnetization. These results suggest that the SMM properties of TbPc₂ highly depend on the molecular packing.
NASA Astrophysics Data System (ADS)
Adie Perdana, Fengky; Supriyanto, Agus; Purwanto, Agus; Jamaluddin, Anif
2017-01-01
The purpose of this research focuses on the effect of imbalanced internal resistance for the drop voltage of LiFePO4 18650 battery system connected in parallel. The battery pack has been assembled consist of two cell battery LiFePO4 18650 that has difference combination of internal resistance. Battery pack was tested with 1/C constant current charging, 3,65V per group sel, 3,65V constant voltage charging, 5 minutes of rest time between charge and discharge process, 1/2C Constant current discharge until 2,2V, 26 cycle of measurement test, and 4320 minutes rest time after the last charge cycle. We can conclude that the difference combination of internal resistance on the battery pack seriously influence the drop voltage of a battery. Theoretical and experimental result show that the imbalance of internal resistance during cycling are mainly responsible for the drop voltage of LiFePO4 parallel batteries. It is thus a good way to avoid drop voltage fade of parallel battery system by suppressing variations of internal resistance.
Studies of Current Circulation at Ocean Waste Disposal Sites
NASA Technical Reports Server (NTRS)
Klemas, V. (Principal Investigator); Davis, G.; Henry, R.
1976-01-01
The author has identified the following significant results. Acid waste plume was observed in LANDSAT imagery fourteen times ranging from during dump up to 54 hours after dump. Circulation processes at the waste disposal site are highly storm-dominated, with the majority of the water transport occurring during strong northeasterlies. There is a mean flow to the south along shore. This appears to be due to the fact that northeasterly winds produce stronger currents than those driven by southeasterly winds and by the thermohaline circulation. During the warm months (May through October), the ocean at the dump site stratifies with a distinct thermocline observed during all summer cruising at depths ranging from 10 to 21 m. During stratified conditions, the near-bottom currents were small. Surface currents responded to wind conditions resulting in rapid movement of surface drogues on windy days. Mid-depth drogues showed an intermediate behavior, moving more rapidly as wind velocities increased.
NASA Astrophysics Data System (ADS)
Parsons, W. M.; Sims, J. R.; Parker, J. V.
1986-11-01
The Lethality Test System (LTS) under construction at Los Alamos is an electromagnetic launcher facility designed to perform impact experiments at velocities up to 15 km/sec. The launcher is a 25 mm round bore, plasma armature railgun 22 m in length. Preinjection is accomplished with a two-stage light gas gun capable of 7 km/sec. The railgun power supply utilizes traction motors, vacuum interrupters, and pulse transformers. An assembly of 28 traction motors, equipped with flywheels, stores approximately 80 MJ at 92 percent of full speed and energizes the primary windings of three pulse transformers at a current of 50 kA. At peak current an array of vacuum interrupters disconnects the transformer primary windings and forces the current to flow in the secondary windings. The secondary windings are connected to the railgun, and by staging the vacuum interrupter openings, a 1-1.3 MA ramped current waveform will be delivered to the railgun.
Review of fluid and control technology of hydraulic wind turbines
NASA Astrophysics Data System (ADS)
Cai, Maolin; Wang, Yixuan; Jiao, Zongxia; Shi, Yan
2017-09-01
This study examines the development of the fluid and control technology of hydraulic wind turbines. The current state of hydraulic wind turbines as a new technology is described, and its basic fluid model and typical control method are expounded by comparing various study results. Finally, the advantages of hydraulic wind turbines are enumerated. Hydraulic wind turbines are expected to become the main development direction of wind turbines.
Wind Power Generation Design Considerations.
1984-12-01
DISTRIBUTION 4 I o ....................................... . . . e . * * TABLES Number Page I Wind Turbine Characteristics II 0- 2 Maximum Economic Life II 3...Ratio of Blade Tip Speed to Wind Speed 10 4 Interference with Microwave and TV Reception by Wind Turbines 13 5 Typical Flow Patterns Over Two...18 * 12 Annual Mean Wind Power Density 21 5 FIGURES (Cont’d) Number Page 13 Wind - Turbine /Generator Types Currently Being Tested on Utility Sites 22 14
Quantitative Scrutinization of Aflatoxins in Different Spices from Pakistan
Kashif, Aiza; Kanwal, Kinza; Khan, Abdul Muqeet; Abbas, Mateen
2016-01-01
The current research work aimed to access the contamination level of aflatoxins B1, B2, G1, and G2 in the household spices that are widely consumed in huge amounts. 200 different spice samples, 100 packed and 100 unpacked, were analyzed for the aflatoxins profile by HPLC with an incidence of 61.5% contamination out of which 53.66% samples exceed the EU limit. The results disclosed that the unpacked samples are more contaminated as compared to the packed samples except for white cumin seeds. Among packed and unpacked samples of spices, the maximum value of aflatoxins was detected in fennel, that is, 27.93 μg/kg and 67.04 μg/kg, respectively. The lowest concentration of aflatoxin was detected in cinnamon in packed form (0.79 μg/kg) and in the unpacked samples of white cumin seeds which is 1.75 μg/kg. Caraway seeds and coriander in its unpacked form showed positive results whereas black pepper (packed and unpacked) was found free from aflatoxins. This is the first report on the occurrence of aflatoxins in packed and unpacked samples of spices from Pakistan. To ensure safe consumption of spices, there should be constant monitoring of aflatoxin and more studies need to be executed with the intention of preventing mycotoxin accretion in this commodity. PMID:27781067
Lund, Ingeborg; Scheffels, Janne
2013-10-24
In an attempt to minimize the pack design avenue of communication between tobacco producers and smokers and potential smokers, several jurisdictions, including Norway, have considered regulations on cigarette pack design. The main aim of the current study was to investigate how package design affects young people's perceptions of typical smokers of some pre-chosen cigarette brands and brand varieties. Based on data from a web survey among 1022 15-22 year-olds, possible effects of plain packaging of cigarettes on adolescents' views about typical cigarette smokers were investigated. The data collection had a between-subjects design, in which participants were allocated to one of three groups, and asked to typify the smokers of selected cigarette packs either in branded, plain or plain with descriptor versions. The sample included boys and girls, and smokers and non-smokers. The smoker characteristics included in the investigation were: gender, glamour, stylishness, popularity, coolness, sophistication and slimness. After creating sum-scores within and across packs and pack versions, analyses indicated that a shift from branded to plain cigarette packaging would result in a reduction in positive user images related to smoking among adolescents and young adults. For girls, this effect held up after controlling for confounders. To the extent that plain packaging contributes to making smoking images less positive, it can potentially be an efficient aid in reducing smoking uptake among adolescents.
Hydrodynamic flow in capillary-channel fiber columns for liquid chromatography.
Stanelle, Rayman D; Sander, Lane C; Marcus, R Kenneth
2005-12-23
The flow characteristics of capillary-channel polymer (C-CP) fiber liquid chromatographic (LC) columns have been investigated. The C-CP fibers are manufactured with eight longitudinal grooves (capillary channels) extending the length of the fibers. Three C-CP fiber examples were studied, with fiber dimensions ranging from approximately 35 microm to 65 microm, and capillary-channel dimensions ranging from approximately 6 microm to 35 microm. The influence of fiber packing density and column inner diameter on peak asymmetry, peak width, and run-to-run reproducibility have been studied for stainless steel LC columns packed with polyester (PET) and polypropylene (PP) C-CP fibers. The van Deemter A-term was evaluated as a function of fiber packing density (approximately 0.3 g/cm(3)-0.75 g/cm(3)) for columns of 4.6 mm inner diameter (i.d.) and at constant packing densities for 1.5 mm, 3.2 mm, 4.6 mm, and 7.7 mm i.d. columns. Although column diameter had little influence on the eluting peak widths, peak asymmetry increased with increasing column diameter. The A-terms for the C-CP fiber packed columns are somewhat larger than current commercial, microparticulate-packed columns, and means for improvement are discussed. Applications in the area of protein (macromolecule) separations appear the most promising at this stage of the system development.
Air core poloidal magnetic field system for a toroidal plasma producing device
Marcus, Frederick B.
1978-01-01
A poloidal magnetics system for a plasma producing device of toroidal configuration is provided that reduces both the total volt-seconds requirement and the magnitude of the field change at the toroidal field coils. The system utilizes an air core transformer wound between the toroidal field (TF) coils and the major axis outside the TF coils. Electric current in the primary windings of this transformer is distributed and the magnetic flux returned by air core windings wrapped outside the toroidal field coils. A shield winding that is closely coupled to the plasma carries a current equal and opposite to the plasma current. This winding provides the shielding function and in addition serves in a fashion similar to a driven conducting shell to provide the equilibrium vertical field for the plasma. The shield winding is in series with a power supply and a decoupling coil located outside the TF coil at the primary winding locations. The present invention requires much less energy than the usual air core transformer and is capable of substantially shielding the toroidal field coils from poloidal field flux.
A numerical study on the evolution of the wind-driven circulation in the Yellow Sea in winter
NASA Astrophysics Data System (ADS)
Tak, Y. J.; Cho, Y. K.
2016-02-01
The Yellow Sea is a semi-enclosed marginal sea and its circulation in winter is affected by the winter monsoon. In previous studies, it was found that the circulation of the Yellow Sea in winter consists of downwind and upwind currents. Downwind currents consisting of the Korean Coast Current (KCC) and the Chinese Coast Current (CCC) flow along the boundary of the Yellow Sea, whereas an upwind current consisting of the Yellow Sea Warm Current (YSWC) flows along the central trough of the Yellow Sea. Although some characteristics of such currents and the driving forces of the circulation have been studied by many scientists, the evolution of these currents has received little attention. So, the wind-driven circulation in the Yellow Sea was simulated to explain the changing pattern of these currents in winter and their evolutions were explored by the time-lagged correlation for winter season. According to the lagged correlation, downwind currents occurred in surface layer without a time lag. These downwind currents were more sensitive in the Chinese coast than that in the Korean coast. There is one day time-lag between the wind and the upwind flow developing in the Yellow Sea trough. The YSWC was shifted to the west of the trough after two days and then the KCC strengthened at the same time. It implied the westward shift of the YSWC and the clockwise circulation is developed, two days after the wind blows. The clockwise circulation was one of the reasons that the KCC was stronger than the CCC although the CCC was more sensitive to the wind than the KCC. The clockwise circulation also made the YSWC stronger in the inner YS than it at the entrance of the YS.
NASA Astrophysics Data System (ADS)
McPherron, R. L.; Anderson, B. J.; Chu, Xiangning
2018-03-01
The strength of field-aligned currents coupling the magnetosphere to the ionosphere was obtained by the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) using the network of Iridium® spacecraft. The distribution of current was integrated giving total current in and out of the ionosphere on the dayside and nightside of the Earth in both hemispheres. The onset of auroral zone negative bays and midlatitude positive bays corresponds to an increase in nightside upward current. The total outward current tends toward saturation with increasing solar wind driver strength. The optimum solar wind coupling function for AL index predicts 73% of the variance in nightside upward current. The dayside and nightside predictors of upward current rise to a peak at 30-45 min and decay slowly over 2.5 hr. Nightside response is delayed relative to dayside.
Earth Obsersation taken by the Expedition 11 crew
2005-07-09
ISS011-E-10255 (9 July 2005) --- This easterly-looking image from the International Space Station shows Hurricane Dennis after the storm had already crossed Cuba and was heading for the northern Gulf of Mexico. Dennis was a Category 3 storm, packing winds of 115 miles per hour, at the time of exposure and located approximately 385 miles southeast of Biloxi, Mississippi or 280 miles south of Panama City, Florida. The eye of the hurricane is in the center of the frame, exposed at 22:06:54 (GMT), July 9, 2005. The dark triangle in loer right corner is part of the Space Station's window.
Earth Obsersation taken by the Expedition 11 crew
2005-07-09
ISS011-E-10257 (9 July 2005) --- This easterly-looking image from the International Space Station shows Hurricane Dennis after the storm had already crossed Cuba and was heading for the northern Gulf of Mexico. Dennis was a Category 3 storm, packing winds of 115 miles per hour, at the time of exposure and located approximately 385 miles southeast of Biloxi, Mississippi or 280 miles south of Panama City, Florida. The image was exposed at 22:07:26 (GMT), July 9, 2005. The storm's eye is just to the right of frame center. The black triangle in extreme lower right is part of the Space Station's window.
NASA Astrophysics Data System (ADS)
Daniel, Michael T.
Here in the early 21st century humanity is continuing to seek improved quality of life for citizens throughout the world. This global advancement is providing more people than ever with access to state-of-the-art services in areas such as transportation, entertainment, computing, communication, and so on. Providing these services to an ever-growing population while considering the constraints levied by continuing climate change will require new frontiers of clean energy to be developed. At the time of this writing, offshore wind has been proven as both a politically and economically agreeable source of clean, sustainable energy by northern European nations with many wind farms deployed in the North, Baltic, and Irish Seas. Modern offshore wind farms are equipped with an electrical system within the farm itself to aggregate the energy from all turbines in the farm before it is transmitted to shore. This collection grid is traditionally a 3-phase medium voltage alternating current (MVAC) system. Due to reactive power and other practical constraints, it is preferable to use a medium voltage direct current (MVDC) collection grid when siting farms >150 km from shore. To date, no offshore wind farm features an MVDC collection grid. However, MVDC collection grids are expected to be deployed with future offshore wind farms as they are sited further out to sea. In this work it is assumed that many future offshore wind farms may utilize an MVDC collection grid to aggregate electrical energy generated by individual wind turbines. As such, this work presents both per-phase and per-pole power electronic converter systems suitable for interfacing individual wind turbines to such an MVDC collection grid. Both interfaces are shown to provide high input power factor at the wind turbine while providing DC output current to the MVDC grid. Common mode voltage stress and circulating currents are investigated, and mitigation strategies are provided for both interfaces. A power sharing scheme for connecting multiple wind turbines in series to allow for a higher MVDC grid voltage is also proposed and analyzed. The overall results show that the proposed per-pole approach yields key advantages in areas of common mode voltage stress, circulating current, and DC link capacitance, making it the more appropriate choice of the two proposed interfaces for this application.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Strach-Sonsalla, Mareike; Stammler, Matthias; Wenske, Jan
In 1991, the Vindeby Offshore Wind Farm, the first offshore wind farm in the world, started feeding electricity to the grid off the coast of Lolland, Denmark. Since then, offshore wind energy has developed from this early experiment to a multibillion dollar market and an important pillar of worldwide renewable energy production. Unit sizes grew from 450 kW at Vindeby to the 7.5 MW-class offshore wind turbines (OWT ) that are currently (by October 2014) in the prototyping phase. This chapter gives an overview of the state of the art in offshore wind turbine (OWT) technology and introduces the principlesmore » of modeling and simulating an OWT. The OWT components -- including the rotor, nacelle, support structure, control system, and power electronics -- are introduced, and current technological challenges are presented. The OWT system dynamics and the environment (wind and ocean waves) are described from the perspective of OWT modelers and designers. Finally, an outlook on future technology is provided. The descriptions in this chapter are focused on a single OWT -- more precisely, a horizontal-axis wind turbine -- as a dynamic system. Offshore wind farms and wind farm effects are not described in detail in this chapter, but an introduction and further references are given.« less
Using Reconstructed POD Modes as Turbulent Inflow for LES Wind Turbine Simulations
NASA Astrophysics Data System (ADS)
Nielson, Jordan; Bhaganagar, Kiran; Juttijudata, Vejapong; Sirisup, Sirod
2016-11-01
Currently, in order to get realistic atmospheric effects of turbulence, wind turbine LES simulations require computationally expensive precursor simulations. At times, the precursor simulation is more computationally expensive than the wind turbine simulation. The precursor simulations are important because they capture turbulence in the atmosphere and as stated above, turbulence impacts the power production estimation. On the other hand, POD analysis has been shown to be capable of capturing turbulent structures. The current study was performed to determine the plausibility of using lower dimension models from POD analysis of LES simulations as turbulent inflow to wind turbine LES simulations. The study will aid the wind energy community by lowering the computational cost of full scale wind turbine LES simulations, while maintaining a high level of turbulent information and being able to quickly apply the turbulent inflow to multi turbine wind farms. This will be done by comparing a pure LES precursor wind turbine simulation with simulations that use reduced POD mod inflow conditions. The study shows the feasibility of using lower dimension models as turbulent inflow of LES wind turbine simulations. Overall the power production estimation and velocity field of the wind turbine wake are well captured with small errors.
Noble, M.A.; Ramp, S.R.
2000-01-01
In February 1991, an array of six current-meter moorings was deployed for one year across the central California outer shelf and slope. The main line of the array extended 30 km offshore of the shelf break, out to water depths of 1400 m. A more sparsely-instrumented line, displaced 30 km to the northwest, extended 14 km offshore. Though shorter, the northern line spanned similar water depths because the gradient of the topography steepened in the northern region. A poleward flow pattern, typical of the California undercurrent, was seen across both lines in the array over most of the year. The poleward flow was surface intensified. In general, the portion of the undercurrent that crossed the southern line had larger amplitudes and penetrated more deeply into the water column than the portion that crossed the northern line. Transport over the year ranged from 0 to 2.5 Sverdrups (Sv) poleward across the southern line; 0 to 1 Sv poleward across the northern line. We suggest the difference in transport was caused by topographic constraints, which tended to force the poleward flow offshore of the northern measurement sites. The slope of the topography steepened too abruptly to allow the poleward flow to follow isobaths when currents were strong. When current velocities lessened, a more coherent flow pattern was seen across both lines in the array. In general, the poleward flow patterns in the undercurrent were not affected by local winds or by the local alongshore pressure gradient. Nor was a strong seasonal pattern evident. Rather unexpectedly, a small but statistically significant fraction of the current variance over the mid- and outer slope was driven by the surface wind stress. An alongshelf wind stress caused currents to flow along the slope, parallel to the wind field, down to depths of 400 m below the surface and out to distances of 2 Rossby radii past the shelf break. The transfer functions were weak, 3-4 cm/s per dyn cm-2, but comparable to wind-driven current amplitudes of 4-6 cm/s per unit wind stress over the middle shelf. Equatorward, alongshelf winds also caused water from 200-300 m over the slope to upwell onto the shelf as the surface water moved offshore.
Discussion on mass concrete construction of wind turbine generator foundation
NASA Astrophysics Data System (ADS)
Shang, Liang; Wu, Chaoxiang; Yin, Xiaoyong
2018-04-01
Wind power is one of the main power sources currently. China has rich wind power resources, wind power plants are developed faster and faster. However, China wind power construction started late, which is lack of relevant experience technology. It is easy to produce quality problems. The key to the construction quality of wind power plant is the construction quality of mass concrete construction. Therefore, construction technology and quality control of wind turbine generator foundation mass concrete are discussed and analyzed in the paper.
Investigation of water vapor motion winds from geostationary satellites
NASA Technical Reports Server (NTRS)
Velden, Christopher
1993-01-01
Motions deduced in animated water vapor imagery from geostationary satellites can be used to infer wind fields in cloudless regimes. For the past several years, CIMSS has been exploring this potentially important source of global-scale wind information. Recently, METEOSAT-3 data has become routinely available to both the U.S. operational and research community. Compared with the current GOES satellite, the METEOSAT has a superior resolution (5 km vs. 16 km) in its water vapor channel. Preliminary work: at CIMSS has demonstrated that wind sets derived from METEOSAT water vapor imagery can provide important upper-tropospheric wind information in data void areas, and can positively impact numerical model guidance in meteorological applications. Specifically, hurricane track forecasts can be improved. Currently, we are exploring methods to further improve the derivation and quality of the water vapor wind sets.
Variable speed wind turbine generator with zero-sequence filter
Muljadi, Eduard
1998-01-01
A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.
Variable Speed Wind Turbine Generator with Zero-sequence Filter
Muljadi, Eduard
1998-08-25
A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.
Variable speed wind turbine generator with zero-sequence filter
Muljadi, E.
1998-08-25
A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility. 14 figs.
A numerical study of the South China Sea Warm Current during winter monsoon relaxation
NASA Astrophysics Data System (ADS)
Zhang, Cong; Ding, Yang; Bao, Xianwen; Bi, Congcong; Li, Ruixiang; Zhang, Cunjie; Shen, Biao; Wan, Kai
2018-03-01
Using a Finite-Volume Community Ocean Model, we investigated the dynamic mechanism of the South China Sea Warm Current (SCSWC) in the northern South China Sea (NSCS) during winter monsoon relaxation. The model reproduces the mean surface circulation of the NSCS during winter, while model-simulated subtidal currents generally capture its current pattern. The model shows that the current over the continental shelf is generally southwestward, under a strong winter monsoon condition, but a northeastward counter-wind current usually develops between 50-and 100-m isobaths, when the monsoon relaxes. Model experiments, focusing on the wind relaxation process, show that sea level is elevated in the northwestern South China Sea (SCS), related to the persistent northeasterly monsoon. Following wind relaxation, a high sea level band builds up along the mid-shelf, and a northeastward current develops, having an obvious vertical barotropic structure. Momentum balance analysis indicates that an along-shelf pressure gradient provides the initial driving force for the SCSWC during the first few days following wind relaxation. The SCSWC subsequently reaches a steady quasi-geostrophic balance in the cross-shelf direction, mainly linked to sea level adjustment over the shelf. Lagrangian particle tracking experiments show that both the southwestward coastal current and slope current contribute to the northeastward movement of the SCSWC during winter monsoon relaxation.
Evans, C E L; Greenwood, D C; Thomas, J D; Cleghorn, C L; Kitchen, M S; Cade, J E
2010-11-01
Government standards are now in place for children's school meals but not for lunches prepared at home. The aim of this trial is to improve the content of children's packed lunches. A cluster randomised controlled trial in 89 primary schools across the UK involving 1291 children, age 8-9 years at baseline. Follow-up was 12 months after baseline. A "SMART" lunch box intervention programme consisted of food boxes, bag and supporting materials. The main outcome measures were weights of foods and proportion of children provided with sandwiches, fruit, vegetables, dairy food, savoury snacks and confectionery in each packed lunch. Levels of nutrients provided including energy, total fat, saturated fat, protein, non-milk extrinsic sugar, sodium, calcium, iron, folate, zinc, vitamin A and vitamin C. Moderately higher weights of fruit, vegetables, dairy and starchy food and lower weights of savoury snacks were provided to children in the intervention group. Children in the intervention group were provided with slightly higher levels of vitamin A and folate. 11% more children were provided with vegetables/salad in their packed lunch, and 13% fewer children were provided with savoury snacks (crisps). Children in the intervention group were more likely to be provided with packed lunches meeting the government school meal standards. The SMART lunch box intervention, targeting parents and children, led to small improvements in the food and nutrient content of children's packed lunches. Further interventions are required to bring packed lunches in line with the new government standards for school meals. Current controlled trials ISRCTN77710993.
Performance characteristics of an electric vehicle lead-acid battery pack at elevated temperatures
NASA Technical Reports Server (NTRS)
Chapman, P.
1982-01-01
Discharge testing data electric car battery pack over initial electrolyte temperature variations between 27 and 55 C are presented. The tests were conducted under laboratory conditions and then compared to detailed electric vehicle simulation models. Battery discharge capacity increased with temperature for constant current discharges, and battery energy capacity increased with temperature for constant power discharges. Dynamometer tests of the electric test vehicle showed an increase in range of 25% for the higher electrolyte temperature.
2013-04-01
Cream of Chicken Soup, Marmalade, Orange Sports Powder, Grape Sports Powder, Banana Berry Candy, Musk Candy, Tomato Ketchup and Sweet Chilli Sauce...Strong Peppermint (ESP) Candy............................................... 19 3.8.3 Banana Berry Candy...M M Marmalade P P P M AR Plum Fruit Spread P P P P P Strawberry Fruit Spread P M P P P P Chocolate Candy M Banana Berry Candy P M M M M P AR Musk
Spatial mapping and attribution of Wyoming wind turbines, 2012
O'Donnell, Michael S.; Fancher, Tammy S.
2014-01-01
These data represent locations of wind turbines found within Wyoming as of August 2012. We assigned each wind turbine to a wind farm and, in these data, provide information about each turbine’s potential megawatt output, rotor diameter, hub height, rotor height, the status of the land ownership where the turbine exists, the county each turbine is located in, wind farm power capacity, the number of units currently associated with each wind farm, the wind turbine manufacturer and model, the wind farm developer, the owner of the wind farm, the current purchaser of power from the wind farm, the year the wind farm went online, and the status of its operation. Some of the attributes are estimates based on the information we found via the American Wind Energy Association and other on-line reports. The locations are derived from National Agriculture Imagery Program (2009 and 2012) true color aerial photographs and have a positional accuracy of approximately +/-5 meters. These data will provide a planning tool for wildlife- and habitat-related projects underway at the U.S. Geological Survey’s Fort Collins Science Center and other government and non-government organizations. Specifically, we will use these data to support quantifying disturbances of the landscape as related to wind energy as well as to quantify indirect disturbances to flora and fauna. This data set represents an update to a previous version by O’Donnell and Fancher (2010).
Feedback between neutral winds and auroral arc electrodynamics
NASA Technical Reports Server (NTRS)
Lyons, L. R.; Walterscheid, R. L.
1986-01-01
The feedback between neutral atmospheric winds and the electrodynamics of a stable, discrete auroral arc is analyzed. The ionospheric current continuity equation and the equation for neutral gas acceleration by ion drag are solved simultaneously, as a function of time. The results show that, in general, the electric field in the ionosphere adjusts to neutral wind acceleration so as to keep auroral field-aligned currents and electron acceleration approximately independent of time. It is thus concluded that the neutral winds that develop as a result of the electrodynamical forcing associated with an arc do not significantly affect the intensity of the arc.
NASA Astrophysics Data System (ADS)
Naaim, Florence; Picard, Ghislain; Bellot, Hervé; Arnaud, Laurent; Vionnet, Vincent
2017-04-01
Some elements of snow surface roughness, such as ripple or sastrugi, are a direct manifestation of wind erosion and in turn modify the near-surface wind field and consequently the horizontal snow mass fluxes. This leads to a negative feedback between wind strength and surface roughness that must be taken into account in numerical models. Formation of sastrugi, which are elongated metric-scale ridges of wind-packed snow whose longitudinal axis is parallel to the prevailing wind at the time of their formation, is still not well-understood. The first step to provide new information about the formation and evolution of such features is to integrate meteorological data and accurate description of geometrical properties. But the complex and dynamic surface of sastrugi cannot be easily captured by manual measurements (Bellot et al., 2014), which furthermore must be frequent as the formation of new landforms can happen very quickly. That's why the potential of a low-cost time-lapse terrestrial laserscan RLS (Picard et al., 2016) has been investigated during the winter seasons 2015-2016 and 2016-2017 at Col du Lac Blanc in the French Alps. This experimental test site, dedicated to drifting snow studies, and subject to the formation of sastrugi is well-suited for such study : accurate meteorological data, including drifting snow fluxes, are available each 10 minutes. RLS covered a surface area of around 200 m2 for a spatial horizontal resolution of nearly 2 cm and monitored successfully surface roughness once a day during the whole winter seasons. Sastrugi geometrical parameters, such as the frontal area and average height of roughness elements has been extracted from the RLS data and the sastrugi morphometry has be examined over two winter seasons in link with snow fall, drifting snow occurence and intensity and wind speed.
An hybrid neuro-wavelet approach for long-term prediction of solar wind
NASA Astrophysics Data System (ADS)
Napoli, Christian; Bonanno, Francesco; Capizzi, Giacomo
2011-06-01
Nowadays the interest for space weather and solar wind forecasting is increasing to become a main relevance problem especially for telecommunication industry, military, and for scientific research. At present the goal for weather forecasting reach the ultimate high ground of the cosmos where the environment can affect the technological instrumentation. Some interests then rise about the correct prediction of space events, like ionized turbulence in the ionosphere or impacts from the energetic particles in the Van Allen belts, then of the intensity and features of the solar wind and magnetospheric response. The problem of data prediction can be faced using hybrid computation methods so as wavelet decomposition and recurrent neural networks (RNNs). Wavelet analysis was used in order to reduce the data redundancies so obtaining representation which can express their intrinsic structure. The main advantage of the wavelet use is the ability to pack the energy of a signal, and in turn the relevant carried informations, in few significant uncoupled coefficients. Neural networks (NNs) are a promising technique to exploit the complexity of non-linear data correlation. To obtain a correct prediction of solar wind an RNN was designed starting on the data series. As reported in literature, because of the temporal memory of the data an Adaptative Amplitude Real Time Recurrent Learning algorithm was used for a full connected RNN with temporal delays. The inputs for the RNN were given by the set of coefficients coming from the biorthogonal wavelet decomposition of the solar wind velocity time series. The experimental data were collected during the NASA mission WIND. It is a spin stabilized spacecraft launched in 1994 in a halo orbit around the L1 point. The data are provided by the SWE, a subsystem of the main craft designed to measure the flux of thermal protons and positive ions.
Stand Alone Battery Thermal Management System
DOE Office of Scientific and Technical Information (OSTI.GOV)
Brodie, Brad
The objective of this project is research, development and demonstration of innovative thermal management concepts that reduce the cell or battery weight, complexity (component count) and/or cost by at least 20%. The project addresses two issues that are common problems with current state of the art lithium ion battery packs used in vehicles; low power at cold temperatures and reduced battery life when exposed to high temperatures. Typically, battery packs are “oversized” to satisfy the two issues mentioned above. The first phase of the project was spent making a battery pack simulation model using AMEsim software. The battery pack usedmore » as a benchmark was from the Fiat 500EV. FCA and NREL provided vehicle data and cell data that allowed an accurate model to be created that matched the electrical and thermal characteristics of the actual battery pack. The second phase involved using the battery model from the first phase and evaluate different thermal management concepts. In the end, a gas injection heat pump system was chosen as the dedicated thermal system to both heat and cool the battery pack. Based on the simulation model. The heat pump system could use 50% less energy to heat the battery pack in -20°C ambient conditions, and by keeping the battery cooler at hot climates, the battery pack size could be reduced by 5% and still meet the warranty requirements. During the final phase, the actual battery pack and heat pump system were installed in a test bench at DENSO to validate the simulation results. Also during this phase, the system was moved to NREL where testing was also done to validate the results. In conclusion, the heat pump system can improve “fuel economy” (for electric vehicle) by 12% average in cold climates. Also, the battery pack size, or capacity, could be reduced 5%, or if pack size is kept constant, the pack life could be increased by two years. Finally, the total battery pack and thermal system cost could be reduced 5% only if the system is integrated with the vehicle cabin air conditioning system. The reason why we were not able to achieve the 20% reduction target is because of the natural decay of the battery cell due to the number of cycles. Perhaps newer battery chemistries that are not so sensitive to cycling would have more potential for reducing the battery size due to thermal issues.« less
Modeling waves and circulation in Lake Pontchartrain, Louisiana
Signell, Richard P.; List, Jeffrey H.
1997-01-01
The U.S. Geological Survey is conducting a study of storm-driven sediment resuspension and transport in Lake Pontchartrain, Louisiana. Two critical processes related to sediment transport in the lake are (1) the resuspension of sediments due to wind-generated storm waves and (2) the movement of resuspended material by lake currents during storm wind events. The potential for sediment resuspension is being studied with the wave prediction model which simulates local generation of waves by wind and shallow-water effects on waves (refraction, shoaling, bottom friction, and breaking). Long-term wind measurements are then used to determine the regional "climate" of bottom orbital velocity (showing the spatial and temporal variability of wave-induced currents at the bottom). The circulation of the lake is being studied with a three-dimensional hydrodynamic model. Results of the modeling effort indicate that remote forcing due to water levels in Mississippi Sound dominate the circulation near the passes in the eastern end of the lake, while local wind forcing dominates water movement in the western end. During typical storms with winds from the north-northeast or the south-southeast, currents along the south coast near New Orleans generally transport material westward, while material in the central region moves against the wind. When periods of sustained winds are followed by a drop in coastal sea level, a large amount of suspended sediment can be flushed from the lake.
Stability analysis of offshore wind farm and marine current farm
NASA Astrophysics Data System (ADS)
Shawon, Mohammad Hasanuzzaman
Renewable energy has been playing an important role to meet power demand and 'Green Energy' market is getting bigger platform all over the world in the last few years. Due to massive increase in the prices of fossil fuels along with global warming issues, energy harvesting from renewable energy sources has received considerable interest, nowadays, where extensive researches are going on to ensure optimum use of renewable sources. In order to meet the increasing demand of electricity and power, integration of renewable energy is getting highest priorities around the world. Wind is one of the most top growing renewable energy resources and wind power market penetration is expected to reach 3.35 percent by 2013 from its present market of about 240 GW. A wind energy system is the most environmental friendly, cost effective and safe among all renewable energy resources available. Another promising form of renewable energy is ocean energy which covers 70 % of the earth. Ocean energy can be tapped from waves, tides and thermal elements. Offshore Wind farm (OWF) has already become very popular for large scale wind power integration with the onshore grid. Recently, marine current farm (MCF) is also showing good potential to become mainstream energy sources and already successfully commissioned in United Kingdom. However, squirrel cage induction generator (SCIG) has the stability problem similar to synchronous generator especially during fault location to restore the electromagnetic torque. Series dynamic braking resistor (SDBR) has been known as a useful mean to stabilize fixed speed wind generator system. On the other hand, doubly fed induction generator (DFIG) has the capability of coupling the control of active and reactive power and to provide necessary reactive power demand during grid fault conditions. Series dynamic braking resistor (SDBR) can also be employed with DFIG to limit the rotor over current. An integration of wind and tidal energy represents a new-trend for large electric energy production using offshore wind generators and marine current generators, respectively. Thus DFIG based offshore wind farm can be an economic solution to stabilize squirrel cage induction generator based marine current farm without installing any addition FACTS devices. This thesis first focuses on the stabilization of fixed speed IG based marine current farm using SDBR. Also stabilization of DFIG based variable speed wind farm utilizing SDBR is studied in this work. Finally a co-operative control strategy is proposed where DFIG is controlled in such a way that it can even provide necessary reactive power demand of induction generator, so that additional cost of FACTS devices can be avoided. In that way, the DFIGs of the offshore wind farm (OWF) will actively compensate the reactive power demand of adjacent IGs of the marine current farm (MCF) during grid fault. Detailed modeling and control scheme for the proposed system are demonstrated considering some realistic scenarios. The power system small signal stability analysis is also carried out by eigenvalue analysis for marine current generator topology, wind turbine generator topology and integrated topology. The relation between the modes and state variables are discussed in light of modal and sensitivity analyses. The results of theoretical analyses are verified by MATLAB/SIMULINK and laboratory standard power system simulator PSCAD/EMTDC.
NASA Astrophysics Data System (ADS)
Wang, Xuping; Quan, Long; Xiong, Guangyu
2013-11-01
Currently, most researches use signals, such as the coil current or voltage of solenoid, to identify parameters; typically, parameter identification method based on variation rate of coil current is applied for position estimation. The problem exists in these researches that the detected signals are prone to interference and difficult to obtain. This paper proposes a new method for detecting the core position by using flux characteristic quantity, which adds a new group of secondary winding to the coil of the ordinary switching electromagnet. On the basis of electromagnetic coupling theory analysis and simulation research of the magnetic field regarding the primary and secondary winding coils, and in accordance with the fact that under PWM control mode varying core position and operating current of windings produce different characteristic of flux increment of the secondary winding. The flux increment of the electromagnet winding can be obtained by conducting time domain integration for the induced voltage signal of the extracted secondary winding, and the core position from the two-dimensional fitting curve of the operating winding current and flux-linkage characteristic quantity of solenoid are calculated. The detecting and testing system of solenoid core position is developed based on the theoretical research. The testing results show that the flux characteristic quantity of switching electromagnet magnetic circuit is able to effectively show the core position and thus to accomplish the non-displacement transducer detection of the said core position of the switching electromagnet. This paper proposes a new method for detecting the core position by using flux characteristic quantity, which provides a new theory and method for switch solenoid to control the proportional valve.
Sediment Redistribution and Seabed Modification in the Western Adriatic
2003-09-30
are slated for use in the model. These changes to the input files result in both better resolution of the Western Adriatic Coastal Current ( WACC ...by transport within the WACC during strong Bora winds (figure 2). Figure 2: Salinity and currents driven by wind stress and buoyancy output...from the northeast, termed “Bora” winds, which intensify the WACC and create merges the 4 discharge of individual Apennine Rivers into a line
33 CFR 162.80 - Mississippi River below mouth of Ohio River, including South and Southwest passes.
Code of Federal Regulations, 2012 CFR
2012-07-01
... withstand currents, winds, wave action, suction from passing vessels or any other forces which might cause... sufficient fastenings to prevent the vessels from breaking loose by wind, current, wave action, suction from...
33 CFR 162.80 - Mississippi River below mouth of Ohio River, including South and Southwest passes.
Code of Federal Regulations, 2010 CFR
2010-07-01
... withstand currents, winds, wave action, suction from passing vessels or any other forces which might cause... sufficient fastenings to prevent the vessels from breaking loose by wind, current, wave action, suction from...
33 CFR 162.80 - Mississippi River below mouth of Ohio River, including South and Southwest passes.
Code of Federal Regulations, 2013 CFR
2013-07-01
... withstand currents, winds, wave action, suction from passing vessels or any other forces which might cause... sufficient fastenings to prevent the vessels from breaking loose by wind, current, wave action, suction from...
33 CFR 162.80 - Mississippi River below mouth of Ohio River, including South and Southwest passes.
Code of Federal Regulations, 2014 CFR
2014-07-01
... withstand currents, winds, wave action, suction from passing vessels or any other forces which might cause... sufficient fastenings to prevent the vessels from breaking loose by wind, current, wave action, suction from...
33 CFR 162.80 - Mississippi River below mouth of Ohio River, including South and Southwest passes.
Code of Federal Regulations, 2011 CFR
2011-07-01
... withstand currents, winds, wave action, suction from passing vessels or any other forces which might cause... sufficient fastenings to prevent the vessels from breaking loose by wind, current, wave action, suction from...
Direct-Current Monitor With Flux-Reset Transformer Coupling
NASA Technical Reports Server (NTRS)
Canter, Stanley
1993-01-01
Circuit measures constant or slowly-varying unidirectional electrical current using flux-reset transformer coupling. Measurement nonintrusive in sense that no need for direct contact with wire that carries load current to be measured, and no need to install series resistive element in load-current path. Toroidal magnetic core wrapped with coil of wire placed around load-current-carrying wire, acts as transformer core, load-current-carrying wire acts as primary winding of transformer, and coil wrapped on core acts as secondary winding.
NASA Astrophysics Data System (ADS)
Dukhovskoy, Dmitry; Bourassa, Mark
2017-04-01
Ocean processes in the Nordic Seas and northern North Atlantic are strongly controlled by air-sea heat and momentum fluxes. The predominantly cyclonic, large-scale atmospheric circulation brings the deep ocean layer up to the surface preconditioning the convective sites in the Nordic Seas for deep convection. In winter, intensive cooling and possibly salt flux from newly formed sea ice erodes the near-surface stratification and the mixed layer merges with the deeper domed layer, exposing the very weakly stratified deep water mass to direct interaction with the atmosphere. Surface wind is one of the atmospheric parameters required for estimating momentum and turbulent heat fluxes to the sea ice and ocean surface. In the ocean models forced by atmospheric analysis, errors in surface wind fields result in errors in air-sea heat and momentum fluxes, water mass formation, ocean circulation, as well as volume and heat transport in the straits. The goal of the study is to assess discrepancies across the wind vector fields from reanalysis data sets and scatterometer-derived gridded products over the Nordic Seas and northern North Atlantic and to demonstrate possible implications of these differences for ocean modeling. The analyzed data sets include the reanalysis data from the National Center for Environmental Prediction Reanalysis 2 (NCEPR2), Climate Forecast System Reanalysis (CFSR), Arctic System Reanalysis (ASR) and satellite wind products Cross-Calibrated Multi-Platform (CCMP) wind product version 1.1 and recently released version 2.0, and Remote Sensing Systems QuikSCAT data. Large-scale and mesoscale characteristics of winds are compared at interannual, seasonal, and synoptic timescales. Numerical sensitivity experiments are conducted with a coupled ice-ocean model forced by different wind fields. The sensitivity experiments demonstrate differences in the net surface heat fluxes during storm events. Next, it is hypothesized that discrepancies in the wind vorticity fields should manifest different behaviors of the isopycnals in the Nordic Seas. Time evolution of isopycnal depths in the sensitivity experiments forced by different wind fields is discussed. Results of these sensitivity experiments demonstrate a relationship between the isopycnal surfaces and the wind stress curl. The numerical experiments are also analyzed to investigate the relationship between the East Greenland Current and the wind stress curl over the Nordic Seas. The transport of the current at this location has substantial contribution from wind-driven large-scale circulation. This wind-driven part of the East Greenland Current is a western-intensified return flow of a wind-driven cyclonic gyre in the central Nordic Seas. The numerical experiments with different wind fields reveal notable sensitivity of the East Greenland Current to differences in the wind forcing.
NASA Astrophysics Data System (ADS)
Radenac, Marie-Hélène; Léger, Fabien; Messié, Monique; Dutrieux, Pierre; Menkes, Christophe; Eldin, Gérard
2016-04-01
Satellite observations of wind, sea level and derived currents, sea surface temperature (SST), and chlorophyll are used to expand our understanding of the physical and biological variability of the ocean surface north of New Guinea. Based on scarce cruise and mooring data, previous studies differentiated a trade wind situation (austral winter) when the New Guinea Coastal Current (NGCC) flows northwestward and a northwest monsoon situation (austral summer) when a coastal upwelling develops and the NGCC reverses. This circulation pattern is confirmed by satellite observations, except in Vitiaz Strait where the surface northwestward flow persists. We find that intraseasonal and seasonal time scale variations explain most of the variance north of New Guinea. SST and chlorophyll variabilities are mainly driven by two processes: penetration of Solomon Sea waters and coastal upwelling. In the trade wind situation, the NGCC transports cold Solomon Sea waters through Vitiaz Strait in a narrow vein hugging the coast. Coastal upwelling is generated in westerly wind situations (westerly wind event, northwest monsoon). Highly productive coastal waters are advected toward the equator and, during some westerly wind events, toward the eastern part of the warm pool. During El Niño, coastal upwelling events and northward penetration of Solomon Sea waters combine to influence SST and chlorophyll anomalies.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hoover, S.
2002-06-01
Studies have shown that raptors flying within the Altamont Pass WRA are vulnerable to fatal turbine collisions, possibly because of their specific foraging and flight behavior. Between June 1999 and June 2000, I conducted 346.5 hours of raptor observations within the Atlamont Pass WRA. Behavior was recorded in relation to characteristics of the topography (slope aspect, elevation, and inclination), the weather, and ground squirrel abundance, as determined by active burrow entrances. The most significant finding of this study revealed that red-tailed hawks and golden eagles flew more in strong winds than in weak winds, particularly along hillsides facing into prevailingmore » winds (as opposed to hillsides shielded from the wind). This is likely a result of the birds' use of declivity currents for lift during flights. These results suggest that certain combinations of topography and weather produce wind currents that are sought out by foraging red-tailed hawks and golden eagles within the Altamont Pass WRA. To decrease raptor mortality, mitigation measures can be targeted to specific areas likely to attract foraging raptors because of their capacity to create particularly favorable wind currents.« less
NASA Astrophysics Data System (ADS)
Duan, Jing; Chen, Zhaohui; Wu, Lixin
2017-05-01
Based on the outputs of 25 models participating in the Coupled Model Intercomparison Project Phase 5, the projected changes of the wind-driven circulation in the low-latitude north-western Pacific are evaluated. Results demonstrate that there will be a decrease in the mean transport of the North Equatorial Current (NEC), Mindanao Current, and Kuroshio Current in the east of the Philippines, accompanied by a northward shift of the NEC bifurcation Latitude (NBL) off the Philippine coast with over 30% increase in its seasonal south-north migration amplitude. Numerical simulations using a 1.5-layer nonlinear reduced-gravity ocean model show that the projected changes of the upper ocean circulation are predominantly determined by the robust weakening of the north-easterly trade winds and the associated wind stress curl under the El Niño-like warming pattern. The changes in the wind forcing and intensified upper ocean stratification are found equally important in amplifying the seasonal migration of the NBL.
Accumulation of BSA in Packed-bed Microfluidics
NASA Astrophysics Data System (ADS)
Summers, Samantha; Hu, Chuntian; Hartman, Ryan
2012-11-01
Alzheimers and Parkinsons are two diseases that are associated with protein deposition in the brain, causing loss of either cognitive or muscle functioning. Protein deposition diseases are considered progressive diseases since the continual aggregation of protein causes the patient's symptoms to slowly worsen over time. There are currently no known means of treatment for protein deposition diseases. Our goal is to understand the potential for packed-bed microfluidics to study protein accumulation. Measurement of the resistance to flow through micro-scale packed-beds is critical to understanding the process of protein accumulation. Aggregation in bulk is fundamentally different from accumulation on surfaces. Our study attempts to distinguish between either mechanism. The results from our experiments involving protein injection through a microfluidic system will be presented and discussed. Funding received by NSF REU Grant 1062611.
Storlazzi, Curt D.; Cheriton, Olivia M.; Lescinski, Jamie M.R.; Logan, Joshua B.
2014-01-01
The U.S. Geological Survey (USGS) Pacific Coastal and Marine Science Center (PCMSC) initiated an investigation in the National Park Service’s (NPS) War in the Pacific National Historical Park (WAPA) to provide baseline scientific information on coastal circulation and water-column properties along west-central Guam, focusing on WAPA’s Agat Unit, as it relates to the transport and settlement of coral larvae, fish, and other marine organisms. The oceanographic data and numerical circulation modeling results from this study demonstrate that circulation in Agat Bay was strongly driven by winds and waves at longer (>1 day) timescales and by the tides at shorter (<1 day) timescales; near-surface currents in deep water were primarily controlled by the winds, whereas currents on the shallow reef flats were dominated by wave-driven motions. Water-column properties exhibited strong seasonality coupled to the shift from the trade wind to the non-trade wind season. During the dry trade-wind season, waters were cooler and more saline. When the winds shifted to a more variable pattern, waters warmed and became less saline because of a combination of increased thermal insolation from lack of wind forcing and higher rainfall. Turbidity was relatively low in Agat Bay and was similar to levels measured elsewhere along west-central Guam. The numerical circulation modeling results provide insight into the potential paths of buoyant material released from a series of locations along west-central Guam under summer non-trade wind forcing conditions that characterize coral spawning events. This information may be useful in evaluating the potential zones of influence/impact resulting from transport by surface currents of material released from these select locations.
Shelf Circulation Induced by an Orographic Wind Jet
NASA Astrophysics Data System (ADS)
Ràfols, Laura; Grifoll, Manel; Jordà, Gabriel; Espino, Manuel; Sairouní, Abdel; Bravo, Manel
2017-10-01
The dynamical response to cross-shelf wind-jet episodes is investigated. The study area is located at the northern margin of the Ebro Shelf, in the Northwestern (NW) Mediterranean Sea, where episodes of strong northwesterly wind occur. In this case, the wind is channeled through the Ebro Valley and intensifies upon reaching the sea, resulting in a wind jet. The wind-jet response in terms of water circulation and vertical density structure is investigated using a numerical model. The numerical outputs agree with water current observations from a high-frequency radar. Additionally, temperature, sea level, and wind measurements are also used for the skill assessment of the model. For the wind-jet episodes, the numerical results show a well-defined two-layer circulation in the cross-shelf direction, with the surface currents in the direction of the wind. This pattern is consistent with sea level set-down due to the wind effect. The comparison of the vertical structure response for different episodes revealed that the increase of stratification leads to an onshore displacement of the transition from inner shelf to mid-shelf. In general, the cross-shelf momentum balance during a wind-jet episode exhibits a balance between the frictional terms and the pressure gradient in shallow waters, shifting to a balance between the Coriolis force and the wind stress terms in deeper waters.
NASA Astrophysics Data System (ADS)
Makowski, Jessica; Chambers, Don; Bonin, Jennifer
2013-04-01
Previous studies have suggested that ocean bottom pressure (OBP) can be used to measure the transport variability of the Antarctic Circumpolar Current (ACC). The OBP observations from the Gravity Recovery and Climate Experiment (GRACE) will be used to calculate transport along the 150°E longitude choke point, between Antarctica and Australia. We will examine whether zonally averaged wind stress, wind stress curl, or local zonal winds are more coherent with zonal mass transport variability. Preliminary studies suggest that seasonal variation in transport across 150°E is more correlated with winds along and north of the northern front of the ACC: the Sub Tropical front (STF). It also appears that interannual variations in transport along 150°E are related to wind variations south of the STF and centered south of the Sub Antarctic Front (SAF). We have observed a strong anti-correlation across the SAF, in the Indian Ocean, which suggests wind stress curl may also be responsible for transport variations. Preliminary results will be presented.
LAWS (Laser Atmospheric Wind Sounder) earth observing system
NASA Technical Reports Server (NTRS)
1988-01-01
Wind profiles can be measured from space using current technology. These wind profiles are essential for answering many of the interdisciplinary scientific questions to be addressed by EOS, the Earth Observing System. This report provides guidance for the development of a spaceborne wind sounder, the Laser Atmospheric Wind Sounder (LAWS), discussing the current state of the technology and reviewing the scientific rationale for the instrument. Whether obtained globally from the EOS polar platform or in the tropics and subtropics from the Space Station, wind profiles from space will provide essential information for advancing the skill of numerical weather prediction, furthering knowledge of large-scale atmospheric circulation and climate dynamics, and improving understanding of the global biogeochemical and hydrologic cycles. The LAWS Instrument Panel recommends that it be given high priority for new instrument development because of the pressing scientific need and the availability of the necessary technology. LAWS is to measure wind profiles with an accuracy of a few meters per second and to sample at intervals of 100 km horizontally for layers km thick.
Acceleration and collimation of magnetized winds
NASA Astrophysics Data System (ADS)
Okamoto, Isao
2000-10-01
The acceleration-collimation problem is discussed for stationary, axisymmetric, polytropic, non-relativistic MHD outflows, with causality and the current-closure condition taken into account. To elucidate the properties of physically realizable `quasi-conical' winds, we consider four kinds of rather unphysical flows in contrast, namely `radial', `asymptotic', `conical' and `current-free' flows. `Radial' flows are supposed to possess the radial structure from the source to infinity, thereby not fulfilling the transfield equation, though keeping causal contact with the source. `Asymptotic' flows coincide in the asymptotic domain with the `quasi-conical' winds, and ones extrapolated inwards from them through the subasymptotic domain to the source. Thirdly, `conical' flows are supposed to satisfy the transfield equation in the subasymptotic domain; thus they are not literally conical, but are supposed to satisfy the `solvability condition at infinity for the conical structure'. It is, however, argued that there is one difficulty in connecting the asymptotic conical structure causally to the structure upstream. Finally, `current-free' flows with no poloidal and toroidal currents everywhere in the wind zone are treated, but it is pointed out that there is no means of satisfying the current-closure condition in the wind zone. Of physical relevance are the `quasi-conical' winds, for which it is shown that the condition that open field lines in the wind zone can reach infinity leads to the requirement that the Poynting flux, proportional to ζ≡αρϖ2η, is not carried to infinity along these field lines, i.e., ζ->0, where α is the angular velocity of field lines, ρ the gas density, and η the mass flux per unit flux tube. While ζ decreases from a value of ζB≡ζA+4πηδα near the coronal base through χχΑ = 4πηαω2Α at the Alfvénic surface to null at infinity, the specific angular momentum of the flow increases up to αω2Α, and the flow energy reaches nearly α2ω2Α at infinity, where δ is a constant of the Bernouilli integral, and ϖA is the axial distance of the Alfvénic surface. It is also argued that `quasi-conical' winds with the current-closure condition fulfilled in the wind zone possess the two-componentness of outflow as one of their generic properties.
The United States currently generates a majority of its electrical power from finite natural resources: an unsustainable practice. The Wind Energy Research Program (WERP) seeks to expand knowledge and awareness of wind power while further decreasing the cost of implem...
NASA Astrophysics Data System (ADS)
Willis, A. E.; Gould, J. M.; Matheney, J. L.; Garrett, H.
1984-01-01
The object of the invention is to provide an improved converter for converting one direct current voltage to another. A plurality of phased square wave voltages are provided from a ring counter through amplifiers to a like plurality of output transformers. Each of these transformers has two windings, and S(1) winding and an S(2) winding. The S(1) windings are connected in series, then the S(2) windings are connected in series, and finally, the two sets of windings are connected in series. One of six SCRs is connected between each two series connected windings to a positive output terminal and one of diodes is connected between each set of two windings of a zero output terminal. By virtue of this configuration, a quite high average direct current voltage is obtained, which varies between full voltage and two-thirds full voltage rather than from full voltage to zero. Further, its variation, ripple frequency, is reduced to one-sixth of that present in a single phase system. Application to raising battery voltage for an ion propulsion system is mentioned.
Comparison of shelf currents off central California prior to and during the 1997-1998 El Nino
Ryan, H.F.; Noble, M.A.
2005-01-01
Moored current, temperature, salinity, and pressure data were collected at three sites that transect the narrow continental shelf offshore of Davenport, CA, starting in August 1996 and continuing to the spring of 1998. This data set allowed a comparison of oceanographic conditions prior to (8/96-3/97) and during (8/97-3/98) the last major El Nin??o. During this El Nin??o, mean temperatures over the 8-month time period were about 3??C warmer than during the prior year at all of the sites. Correlations between near-surface and near-bottom temperatures, and between near-surface temperature and wind stress decreased during the El Nin??o compared to conditions the year before. The mean alongshore currents were more strongly poleward during El Nin??o at sites over the mid-shelf and near the shelf break. There was a general tendency for the energy in alongshore currents to move toward lower frequencies during the El Nin??o, particularly at the sites farther offshore. The processes that forced the shelf flows changed in relative importance throughout the study. The local alongshore wind stress was less important in driving shelf currents during the El Nin??o when much of the wind-induced upwelling was confined to less than 5 km of the coast. The observed strong poleward shelf currents on the mid- to outer-shelf were not clearly tied to local forcing, but were remotely driven, most likely by slope currents. The response of the Davenport shelf to an El Nin??o event may differ from other areas since the shelf is narrow, the wind forcing is weaker than areas to the north and south, and the shelf may be at times isolated by fronts that form at strong upwelling centers. In the winter, strong storm-related winds are important in driving currents at periods not only in the synoptic wind band, but also for periods on the order of 20 d and longer.
An oilspill trajectory analysis model with a variable wind deflection angle
Samuels, W.B.; Huang, N.E.; Amstutz, D.E.
1982-01-01
The oilspill trajectory movement algorithm consists of a vector sum of the surface drift component due to wind and the surface current component. In the U.S. Geological Survey oilspill trajectory analysis model, the surface drift component is assumed to be 3.5% of the wind speed and is rotated 20 degrees clockwise to account for Coriolis effects in the Northern Hemisphere. Field and laboratory data suggest, however, that the deflection angle of the surface drift current can be highly variable. An empirical formula, based on field observations and theoretical arguments relating wind speed to deflection angle, was used to calculate a new deflection angle at each time step in the model. Comparisons of oilspill contact probabilities to coastal areas calculated for constant and variable deflection angles showed that the model is insensitive to this changing angle at low wind speeds. At high wind speeds, some statistically significant differences in contact probabilities did appear. ?? 1982.
SIPEX 2012: Extreme sea-ice and atmospheric conditions off East Antarctica
NASA Astrophysics Data System (ADS)
Heil, P.; Stammerjohn, S.; Reid, P.; Massom, R. A.; Hutchings, J. K.
2016-09-01
In 2012, Antarctic sea-ice coverage was marked by weak annual-mean climate anomalies that consisted of opposing anomalies early and late in the year (some setting new records) which were interspersed by near-average conditions for most of the austral autumn and winter. Here, we investigate the ocean-ice-atmosphere system off East Antarctica, prior to and during the Sea Ice Physics and Ecosystems eXperiment [SIPEX] 2012, by exploring relationships between atmospheric and oceanic forcing together with the sea-ice and snow characteristics. During August and September 2012, just prior to SIPEX 2012, atmospheric circulation over the Southern Ocean was near-average, setting up the ocean-ice-atmosphere system for near-average conditions. However, below-average surface pressure and temperature as well as strengthened circumpolar winds prevailed during June and July 2012. This led to a new record (19.48×106 km2) in maximum Antarctic sea-ice extent recorded in late September. In contrast to the weak circum-Antarctic conditions, the East Antarctic sector (including the SIPEX 2012 region) experienced positive sea-ice extent and concentration anomalies during most of 2012, coincident with negative atmospheric pressure and sea-surface temperature anomalies. Heavily deformed sea ice appeared to be associated with intensified wind stress due to increased cyclonicity as well as an increased influx of sea ice from the east. This increased westward ice flux is likely linked to the break-up of nearly 80% of the Mertz Glacier Tongue in 2010, which strongly modified the coastal configuration and hence the width of the westward coastal current. Combined with favourable atmospheric conditions the associated changed coastal configuration allowed more sea ice to remain within the coastal current at the expense of a reduced northward flow in the region around 141°-145°E. In addition a westward propagating positive anomaly of sea-ice extent from the western Ross Sea during austral winter 2012 has been identified to have fed into the westward current of the SIPEX 2012 region. A pair of large grounded icebergs appears to have modified the local stress state as well as the structure of the ice pack upstream and also towards the Dalton Glacier Tongue. Together with the increased influx of sea ice into the regions, this contributed to the difficulties in navigating the SIPEX 2012 region.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vitina, Aisma; Lüers, Silke; Wallasch, Anna-Kathrin
The International Energy Agency Implementing Agreement for cooperation in Research, Development, and Deployment of Wind Energy Systems (IEA Wind) Task 26—The Cost of Wind Energy represents an international collaboration dedicated to exploring past, present and future cost of wind energy. This report provides an overview of recent trends in wind plant technology, cost, and performance in those countries that are currently represented by participating organizations in IEA Wind Task 26: Denmark, Germany, Ireland, Norway, and the United States as well as the European Union.
Vasilakis, Dimitris P; Whitfield, D Philip; Kati, Vassiliki
2017-01-01
Wind farm development can combat climate change but may also threaten bird populations' persistence through collision with wind turbine blades if such development is improperly planned strategically and cumulatively. Such improper planning may often occur. Numerous wind farms are planned in a region hosting the only cinereous vulture population in south-eastern Europe. We combined range use modelling and a Collision Risk Model (CRM) to predict the cumulative collision mortality for cinereous vulture under all operating and proposed wind farms. Four different vulture avoidance rates were considered in the CRM. Cumulative collision mortality was expected to be eight to ten times greater in the future (proposed and operating wind farms) than currently (operating wind farms), equivalent to 44% of the current population (103 individuals) if all proposals are authorized (2744 MW). Even under the most optimistic scenario whereby authorized proposals will not collectively exceed the national target for wind harnessing in the study area (960 MW), cumulative collision mortality would still be high (17% of current population) and likely lead to population extinction. Under any wind farm proposal scenario, over 92% of expected deaths would occur in the core area of the population, further implying inadequate spatial planning and implementation of relevant European legislation with scant regard for governmental obligations to protect key species. On the basis of a sensitivity map we derive a spatially explicit solution that could meet the national target of wind harnessing with a minimum conservation cost of less than 1% population loss providing that the population mortality (5.2%) caused by the operating wind farms in the core area would be totally mitigated. Under other scenarios, the vulture population would probably be at serious risk of extinction. Our 'win-win' approach is appropriate to other potential conflicts where wind farms may cumulatively threaten wildlife populations.
Whitfield, D. Philip; Kati, Vassiliki
2017-01-01
Wind farm development can combat climate change but may also threaten bird populations’ persistence through collision with wind turbine blades if such development is improperly planned strategically and cumulatively. Such improper planning may often occur. Numerous wind farms are planned in a region hosting the only cinereous vulture population in south-eastern Europe. We combined range use modelling and a Collision Risk Model (CRM) to predict the cumulative collision mortality for cinereous vulture under all operating and proposed wind farms. Four different vulture avoidance rates were considered in the CRM. Cumulative collision mortality was expected to be eight to ten times greater in the future (proposed and operating wind farms) than currently (operating wind farms), equivalent to 44% of the current population (103 individuals) if all proposals are authorized (2744 MW). Even under the most optimistic scenario whereby authorized proposals will not collectively exceed the national target for wind harnessing in the study area (960 MW), cumulative collision mortality would still be high (17% of current population) and likely lead to population extinction. Under any wind farm proposal scenario, over 92% of expected deaths would occur in the core area of the population, further implying inadequate spatial planning and implementation of relevant European legislation with scant regard for governmental obligations to protect key species. On the basis of a sensitivity map we derive a spatially explicit solution that could meet the national target of wind harnessing with a minimum conservation cost of less than 1% population loss providing that the population mortality (5.2%) caused by the operating wind farms in the core area would be totally mitigated. Under other scenarios, the vulture population would probably be at serious risk of extinction. Our ‘win-win’ approach is appropriate to other potential conflicts where wind farms may cumulatively threaten wildlife populations. PMID:28231316
NASA Astrophysics Data System (ADS)
Cho, Yong-Sun; Jung, Byung-Ik; Ha, Kyoung-Hun; Choi, Soo-Geun; Park, Hyoung-Min; Choi, Hyo-Sang
To apply the superconducting fault current limiter (SFCL) to the power system, the reliability of the fault-current-limiting operation must be ensured in diverse fault conditions. The SFCL must also be linked to the operation of the high-speed recloser in the power system. In this study, a three-phase transformer-type SFCL, which has a neutral line to improve the simultaneous quench characteristics of superconducting elements, was manufactured to analyze the fault-current-limiting characteristic according to the single, double, and triple line-to-ground faults. The transformer-type SFCL, wherein three-phase windings are connected to one iron core, reduced the burden on the superconducting element as the superconducting element on the sound phase was also quenched in the case of the single line-to-ground fault. In the case of double or triple line-to-ground faults, the flux from the faulted phase winding was interlinked with other faulted or sound phase windings, and the fault-current-limiting rate decreased because the windings of three phases were inductively connected by one iron core.
The dynamics of subtidal poleward flows over a narrow continental shelf, Palos Verdes, CA
Noble, M.A.; Ryan, H.F.; Wiberg, P.L.
2002-01-01
The Palos Verdes peninsula is a short, very narrow (< 3 km) shelf in southern California that is bracketed by two large embayments. In May 1992, arrays of up to 4 moorings and 2 benthic tripods were deployed in a yearlong study of the circulation processes over this shelf and the adjacent slope. Wind stress, coastal sea level, atmospheric pressure and wave records were obtained from offshore sites and from coastal stations surrounding Palos Verdes. Bottom stress calculated for the mid-shelf sites using a boundary-layer model and data from the above instruments indicated the bottom drag coefficient over this shelf is about 0.003 Currents flow toward the northwest along the shelf and upper slope. Speeds are generally around 20-30 cm/s. There was no obvious seasonal structure in the flow. The first EOF for subtidal alongshelf current accounted for nearly 70% of the variance at sites on the shelf and upper slope. The dominant fluctuations had periods between 5 and 20 days, periods longer than seen in the regional wind stress field. Coastal sea level and the alongshore gradient in sea level had a similar concentration of energy in the 5-20 day frequency band. About 30% of the alongshelf flow was coherent with the alongshelf pressure gradient; currents flowed down the pressure gradient with minimal phase lag. Winds accounted for only 15-20% of the variance in subtidal currents, but the measured effect of wind stress was large. A 1 dyne/cm2 wind stress was associated with a 20-30 cm/s alongshore current. Both the regional wind stress and the alongshelf pressure gradients had spatial scales much larger than found on this small shelf. Subtidal flows forced by these regional fields were set up in the adjacent, much broader basins. The currents amplified as they moved onto the narrow shelf between the basins. Hence, local wind-driven currents had anomalously large amplitudes. The momentum equations for alongshelf wind or pressure gradients did not balance because some of the measured terms were associated with regional fields, others with local process. Our observations suggest that it is more difficult to determine which measured fields reflect the local processes in regions with rapidly changing topography. ?? 2002 Elsevier Science Ltd. All rights reserved.
High energy overcurrent protective device
Praeg, Walter F.
1982-01-01
Electrical loads connected to capacitance elements in high voltage direct current systems are protected from damage by capacitance discharge overcurrents by connecting between the capacitance element and the load, a longitudinal inductor comprising a bifilar winding wound about a magnetic core, which forms an incomplete magnetic circuit. A diode is connected across a portion of the bifilar winding which conducts a unidirectional current only. Energy discharged from the capacitance element is stored in the inductor and then dissipated in an L-R circuit including the diode and the coil winding. Multiple high voltage circuits having capacitance elements may be connected to loads through bifilar windings all wound about the aforementioned magnetic core.
NASA Astrophysics Data System (ADS)
Su, Yuanjie; Xie, Guangzhong; Xie, Fabiao; Xie, Tao; Zhang, Qiuping; Zhang, Hulin; Du, Hongfei; Du, Xiaosong; Jiang, Yadong
2016-06-01
A single-electrode-based segmented triboelectric nanogenerator (S-TENG) was developed. By utilizing the wind-induced vibration of a fluorinated ethylene propylene (FEP) film between two copper electrodes, the S-TENG delivers an open-circuit voltage up to 36 V and a short-circuit current of 11.8 μA, which can simultaneously light up 20 LEDs and charge capacitors. Moreover, the S-TENG holds linearity between output current and flow rate, revealing its feasibility as a self-powered wind speed sensor. This work demonstrates potential applications of S-TENG in wind energy harvester, self-powered gas sensor, high altitude air navigation.
Wind wheel electric power generator
NASA Technical Reports Server (NTRS)
Kaufman, J. W. (Inventor)
1980-01-01
Wind wheel electric power generator apparatus includes a housing rotatably mounted upon a vertical support column. Primary and auxiliary funnel-type, venturi ducts are fixed onto the housing for capturing wind currents and conducting to a bladed wheel adapted to be operatively connected with the generator apparatus. Additional air flows are also conducted onto the bladed wheel; all of the air flows positively effecting rotation of the wheel in a cumulative manner. The auxiliary ducts are disposed at an acute angle with respect to the longitudinal axis of the housing, and this feature, together with the rotatability of the housing and the ducts, permits capture of wind currents within a variable directional range.
The effect of humidity on ionic wind velocity in ambient air
NASA Astrophysics Data System (ADS)
Chen, She; Nobelen, J. C. P. Y.; Nijdam, S.
2016-09-01
Due to the evolution of portable electronics and LED lightning system, advances in air cooling technologies must also keep pace. Active cooling by ionic wind, which is usually generated by corona discharge, can greatly reduce the noise and lifetime issues compared to the mechanical fans. The wind is induced when a gas discharge is formed, and neutral molecules gain their energy by the momentum transfer of ion-neutral collisions. However, there is few discussion about the effect of gas composition such as humidity on the wind generation and the physical mechanism is not clear. In the experiment, a positive 5-20 kV DC voltage is applied to the needle-cylinder electrodes with separation of 20 mm. The ionic wind velocity is measured by hot wire anemometry. As the relative humidity (RH) in the ambient air increases, the velocity is found to be severely inhibited. The current is also measured between the cylinder electrode and earth. The results show that the DC component of corona current decreases when RH increases. Since both the discharge current and the ion mobility are reduced when RH increases, their combined effects determine the ionic wind velocity. This work is supported by STW project 13651.
Airborne microbial composition in a high-throughput poultry slaughtering facility.
Liang, Ruiping; Tian, Jijing; She, Ruiping; Meng, Hua; Xiao, Peng; Chang, Lingling
2013-03-01
A high-throughput chicken slaughtering facility in Beijing was systematically investigated for numbers of airborne microorganisms. Samples were assessed for counts of aerobic bacteria, Staphylococcus aureus, total coliforms, Escherichia coli, Pseudomonas aeruginosa, Listeria monocytogenes, Bacillus cereus, and Salmonella. During a 4-month period (September to December 2011), samples were collected for 10 min three times daily (preproduction, production, and postproduction). Samples were collected for three consecutive days of each month with an FA-1 sampler from six sampling sites: receiving-hanging, soaking-scalding and defeathering, evisceration, precooling, subdividing, and packing. Humidity, temperature, wind velocity, and airborne particulates also were recorded at each sampling site and time. The highest counts of microorganisms were recorded in the initial stages of processing, i.e., the receiving-hanging and defeathering areas, with a definite decline toward the evisceration, prechilling, subdividing, and packing areas; the prechilling area had the lowest microbial counts of 2.4 × 10(3) CFU/m(3). Mean total coliforms counts ranged from 8.4 × 10(3) to 140 CFU/m(3). Maximum E. coli counts were 6.1 × 10(3) CFU/m(3) in the soaking-scalding and defeathering area. B. cereus, P. aeruginosa, and S. aureus represented only a small proportion of the microbial population (1,900 to 20 CFU/m(3)). L. monocytogenes and Salmonella were rarely detected in evisceration, precooling, subdividing, and packing areas. Our study identified the levels of bioaerosols that may affect chicken product quality. This finding could be useful for improved control of microbial contamination to ensure product quality.
Directional Characteristics of Inner Shelf Internal Tides
2007-06-01
Figure 18. YD 202-206 Current vector plot of significant events. Significant events include internal tidal bores, solibores, and solitons . The upper...Events (Bores, Solibores, and Solitons ): Upper column leading-edge cross-shore current velocity and cross-shore wind regression. The small ellipse...Significant Events (Bores, Solibores, and Solitons ): Upper column leading-edge along-shore current velocity and along-shore wind regression. The small
DOE Office of Scientific and Technical Information (OSTI.GOV)
Baring-Gould, I.; Flowers, L.; Kelly, M.
2009-08-01
This paper provides an overview of the Wind for Schools project elements, including a description of host and collegiate school curricula developed for wind energy and the status of the current projects. The paper also provides focused information on how schools, regions, or countries can become involved or implement similar projects to expand the social acceptance and understanding of wind energy.
2013-01-01
Background In an attempt to minimize the pack design avenue of communication between tobacco producers and smokers and potential smokers, several jurisdictions, including Norway, have considered regulations on cigarette pack design. The main aim of the current study was to investigate how package design affects young people’s perceptions of typical smokers of some pre-chosen cigarette brands and brand varieties. Methods Based on data from a web survey among 1022 15–22 year-olds, possible effects of plain packaging of cigarettes on adolescents’ views about typical cigarette smokers were investigated. The data collection had a between-subjects design, in which participants were allocated to one of three groups, and asked to typify the smokers of selected cigarette packs either in branded, plain or plain with descriptor versions. The sample included boys and girls, and smokers and non-smokers. The smoker characteristics included in the investigation were: gender, glamour, stylishness, popularity, coolness, sophistication and slimness. Results After creating sum-scores within and across packs and pack versions, analyses indicated that a shift from branded to plain cigarette packaging would result in a reduction in positive user images related to smoking among adolescents and young adults. For girls, this effect held up after controlling for confounders. Conclusions To the extent that plain packaging contributes to making smoking images less positive, it can potentially be an efficient aid in reducing smoking uptake among adolescents. PMID:24156515
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sinclair, K.
This poster highlights the various wildlife-wind collaboratives (specific to wildlife-wind turbine interaction research) that currently exist. Examples of collaboratives are included along with contact information, objectives, benefits, and ways to advance the knowledge base.
Wind Turbine Structural Dynamics
NASA Technical Reports Server (NTRS)
Miller, D. R. (Editor)
1978-01-01
A workshop on wind turbine structural dynamics was held to review and document current United States work on the dynamic behavior of large wind turbines, primarily of the horizontal-axis type, and to identify and discuss other wind turbine configurations that may have lower cost and weight. Information was exchanged on the following topics: (1) Methods for calculating dynamic loads; (2) Aeroelasticity stability (3) Wind loads, both steady and transient; (4) Critical design conditions; (5) Drive train dynamics; and (6) Behavior of operating wind turbines.
Wind Power Siting: Public Acceptance and Land Use; NREL (National Renewable Energy Laboratory)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tegen, Suzanne
2015-06-17
Suzanne Tegen presented this information as part of the June 17, 2015 WINDExchange webinar: Overcoming Wind Siting Challenges III: Public Acceptance and Land Use. This presentation provides an overview of current NREL research related to wind energy deployment considerations, the DOE Wind Vision as it relates to public acceptance and land use, why public acceptance of wind power matters, where the U.S. wind resource is best, and how those rich resource areas overlay with population centers.
NASA Astrophysics Data System (ADS)
Erofeev, A.; Barth, J. A.; Shearman, R. K.; Pierce, S. D.
2016-02-01
Shelf-deep ocean exchange is dominated by wind-driven upwelling and downwelling in the northern California Current. The interaction of strong, along-shelf jets with coastline and bottom topographic features can also create significant cross-margin exchange. We are using data from over 60,000 kilometers of autonomous underwater glider tracks to understand the temporal and spatial distribution of shelf-deep ocean exchange off central Oregon. Year-round glider observations of temperature, salinity, depth-averaged currents, chlorophyll fluorescence, light backscatter, and colored dissolved organic matter fluorescence from a single cross-margin transect are used to examine shelf-deep ocean exchange mechanisms. During summer, cross-margin exchange is dominated by wind-driven upwelling and the relaxation or reversal of the dominant southward winds. This process has been fairly well observed and studied due to the relatively low sea states and winds during summer. There is far less data from fall and winter off Oregon, a time of strong winds and large waves. We use autonomous underwater gliders to sample during the winter, including through the fall and spring transitions. Glider observations of suspended material detected via light backscatter, show time-space variations in resuspension in the bottom boundary layer due to winds, waves and currents. Examples of shelf-deep ocean exchange are shown by layers with high light backscatter separating from the bottom near the shelf break and extending into the interior along isopycnals. We describe these features and events in relationship to wind-forcing, along-shelf flows, and other forcing mechanisms.
21 CFR 110.40 - Equipment and utensils.
Code of Federal Regulations, 2011 CFR
2011-04-01
... HUMAN CONSUMPTION CURRENT GOOD MANUFACTURING PRACTICE IN MANUFACTURING, PACKING, OR HOLDING HUMAN FOOD... manufacturing systems, including gravimetric, pneumatic, closed, and automated systems, shall be of a design and...
21 CFR 110.40 - Equipment and utensils.
Code of Federal Regulations, 2013 CFR
2013-04-01
... HUMAN CONSUMPTION CURRENT GOOD MANUFACTURING PRACTICE IN MANUFACTURING, PACKING, OR HOLDING HUMAN FOOD... manufacturing systems, including gravimetric, pneumatic, closed, and automated systems, shall be of a design and...
21 CFR 110.40 - Equipment and utensils.
Code of Federal Regulations, 2012 CFR
2012-04-01
... HUMAN CONSUMPTION CURRENT GOOD MANUFACTURING PRACTICE IN MANUFACTURING, PACKING, OR HOLDING HUMAN FOOD... manufacturing systems, including gravimetric, pneumatic, closed, and automated systems, shall be of a design and...
21 CFR 110.40 - Equipment and utensils.
Code of Federal Regulations, 2014 CFR
2014-04-01
... HUMAN CONSUMPTION CURRENT GOOD MANUFACTURING PRACTICE IN MANUFACTURING, PACKING, OR HOLDING HUMAN FOOD... manufacturing systems, including gravimetric, pneumatic, closed, and automated systems, shall be of a design and...
21 CFR 110.40 - Equipment and utensils.
Code of Federal Regulations, 2010 CFR
2010-04-01
... HUMAN CONSUMPTION CURRENT GOOD MANUFACTURING PRACTICE IN MANUFACTURING, PACKING, OR HOLDING HUMAN FOOD... manufacturing systems, including gravimetric, pneumatic, closed, and automated systems, shall be of a design and...
Characterisation of RPLC columns packed with porous sub-2 microm particles.
Petersson, Patrik; Euerby, Melvin R
2007-08-01
Eight commercially available sub-2 microm octadecyl silane columns (C18 columns) have been characterised by the Tanaka protocol. The columns can be grouped into two groups that display large differences in selectivity and peak shape due to differences in hydrophobicity, degree of surface coverage and silanol activity. Measurements of particle size distributions were made using automated microscopy and electrical sensing zone measurements. Only a weak correlation could be found between efficiency and particle size. Large differences in column backpressure were observed. These differences are not related to particle size distribution. A more likely explanation is differences in packing density. In order to take full advantage of 100-150 mm columns packed with sub-2 microm particles, it is often necessary to employ not only an elevated pressure but also an elevated temperature. A comparison between columns packed with sub-2, 3 and 5 microm versions of the same packing indicates potential method transferability problems for several of the columns due to selectivity differences. Currently, the best alternative for fast high-resolution LC is the use of sub-2 microm particles in combination with elevated pressure and temperature. However, as shown in this study additional efforts are needed to improve transferability as well as column performance.
Jawad, Mohammed; Bakir, Ali; Ali, Mohammed; Grant, Aimee
2015-01-01
Despite the rise in prevalence of waterpipe tobacco smoking, it has received little legislative enforcement from governing bodies, especially in the area of health warning labels. Twenty regular waterpipe tobacco smokers from London took part in five focus groups discussing the impact of waterpipe tobacco pack health warnings on their attitudes towards waterpipe smoking. We presented them with existing and mock waterpipe tobacco products, designed to be compliant with current and future UK/EU legislation. Data were analysed using thematic analysis. Participants felt packs were less attractive and health warnings were more impactful as health warnings increased in size and packaging became less branded. However, participants highlighted their lack of exposure to waterpipe tobacco pack health warnings due to the inherent nature of waterpipe smoking, that is, smoking in a café with the apparatus already prepacked by staff. Health warnings at the point of consumption had more reported impact than health warnings at the point of sale. Waterpipe tobacco pack health warnings are likely to be effective if compliant with existing laws and exposed to end-users. Legislations should be reviewed to extend health warning labels to waterpipe accessories, particularly the apparatus, and to waterpipe-serving premises.
Public support for pictorial warnings on cigarette packs: an experimental study of US smokers.
Hall, Marissa G; Marteau, Theresa M; Sunstein, Cass R; Ribisl, Kurt M; Noar, Seth M; Orlan, Elizabeth N; Brewer, Noel T
2018-06-01
Understanding factors that influence public support for "nudging" policies, like pictorial cigarette pack warnings, may offer insight about how to increase such support. We sought to examine factors that influence smokers' support for requiring pictorial warnings on cigarette packs. In 2014 and 2015, we randomly assigned 2149 adult US smokers to receive either pictorial warnings or text-only warnings on their cigarette packs for 4 weeks. The outcome examined in the current study was support for a policy requiring pictorial warnings on cigarette packs in the US. Support for pictorial warnings was high at baseline (mean: 3.2 out of 4). Exposure to pictorial warnings increased policy support at week 4 (β = .05, p = .03). This effect was explained by increases in perceived message effectiveness (p < .001) and reported conversations about policy support (p < .001). Message reactance (i.e., an oppositional reaction to the warning) partially diminished the impact of pictorial warnings on policy support (p < .001). Exposing people to a new policy through implementation could increase public support for that policy by increasing perceived effectiveness and by prompting conversations about the policy. Reactance may partially weaken the effect of policy exposure on public support.
Bakir, Ali; Ali, Mohammed; Grant, Aimee
2015-01-01
Background. Despite the rise in prevalence of waterpipe tobacco smoking, it has received little legislative enforcement from governing bodies, especially in the area of health warning labels. Methods. Twenty regular waterpipe tobacco smokers from London took part in five focus groups discussing the impact of waterpipe tobacco pack health warnings on their attitudes towards waterpipe smoking. We presented them with existing and mock waterpipe tobacco products, designed to be compliant with current and future UK/EU legislation. Data were analysed using thematic analysis. Results. Participants felt packs were less attractive and health warnings were more impactful as health warnings increased in size and packaging became less branded. However, participants highlighted their lack of exposure to waterpipe tobacco pack health warnings due to the inherent nature of waterpipe smoking, that is, smoking in a café with the apparatus already prepacked by staff. Health warnings at the point of consumption had more reported impact than health warnings at the point of sale. Conclusions. Waterpipe tobacco pack health warnings are likely to be effective if compliant with existing laws and exposed to end-users. Legislations should be reviewed to extend health warning labels to waterpipe accessories, particularly the apparatus, and to waterpipe-serving premises. PMID:26273642
NASA Astrophysics Data System (ADS)
Hu, Jian; Jiang, Nan; Li, Jie; Shang, Kefeng; Lu, Na; Wu, Yan; Mizuno, Akira
2016-03-01
The discharge characteristics of the series surface/packed-bed discharge (SSPBD) reactor driven by bipolar pulse power were systemically investigated in this study. In order to evaluate the advantages of the SSPBD reactor, it was compared with traditional surface discharge (SD) reactor and packed-bed discharge (PBD) reactor in terms of the discharge voltage, discharge current, and ozone formation. The SSPBD reactor exhibited a faster rising time and lower tail voltage than the SD and PBD reactors. The distribution of the active species generated in different discharge regions of the SSPBD reactor was analyzed by optical emission spectra and ozone analysis. It was found that the packed-bed discharge region (3.5 mg/L), rather than the surface discharge region (1.3 mg/L) in the SSPBD reactor played a more important role in ozone generation. The optical emission spectroscopy analysis indicated that more intense peaks of the active species (e.g. N2 and OI) in the optical emission spectra were observed in the packed-bed region. supported by National Natural Science Foundation of China (No. 51177007), the Joint Funds of National Natural Science Foundation of China (No. U1462105), and Dalian University of Technology Fundamental Research Fund of China (No. DUT15RC(3)030)
Field-aligned currents and large scale magnetospheric electric fields
NASA Technical Reports Server (NTRS)
Dangelo, N.
1980-01-01
D'Angelo's model of polar cap electric fields (1977) was used to visualize how high-latitude field-aligned currents are driven by the solar wind generator. The region 1 and region 2 currents of Iijima and Potemra (1976) and the cusp field-aligned currents of Wilhjelm et al. (1978) and McDiarmid et al. (1978) are apparently driven by different generators, although in both cases the solar wind is their ultimate source.
Complementing hydropower with PV and wind: optimal energy mix in a fully renewable Switzerland
NASA Astrophysics Data System (ADS)
Dujardin, Jérôme; Kahl, Annelen; Kruyt, Bert; Lehning, Michael
2017-04-01
Like several other countries, Switzerland plans to phase out its nuclear power production and will replace most or all of it by renewables. Switzerland has the chance to benefit from a large hydropower potential and has already exploited almost all of it. Currently about 60% of the Swiss electricity consumption is covered by hydropower, which will eventually leave a gap of about 40% to the other renewables mainly composed of photovoltaics (PV) and wind. With its high flexibility, storage hydropower will play a major role in the future energy mix, providing valuable power and energy balance. Our work focuses on the interplay between PV, wind and storage hydropower, to analyze the dynamics of this complex system and to identify the best PV-wind mixing ratio. Given the current electricity consumption and the currently installed pumping capacity of the storage hydropower plants, it appears that the Swiss hydropower system can completely alleviate the intermittency of PV and wind. However, some seasonal mismatch between production and demand will remain, but we show that oversizing the production from PV and wind or enlarging the reservoir capacity can be a solution to keep it to an acceptable level or even eliminate it. We found that PV, wind and hydropower performs the best together when the share of PV in the solar - wind mix is between 20 and 60%. These findings are quantitatively specific for Switzerland but qualitatively transferable to similar mountainous environments with abundant hydropower resources.
Wind modulation of upwelling at the shelf-break front off Patagonia: Observational evidence
NASA Astrophysics Data System (ADS)
Carranza, M. M.; Gille, S. T.; Piola, A. R.; Charo, M.; Romero, S. I.
2017-03-01
The South-Atlantic Patagonian shelf is the largest chlorophyll-a (Chl-a) hot spot in Southern Ocean color images. While a persistent 1500 km long band of high Chl-a along the shelf-break front (SBF) is indicative of upwelling, the mechanisms that drive it are not entirely known. Along-front wind oscillations can enhance upwelling and provide a nutrient pumping mechanism at shelf-break fronts of western boundary currents. Here we assess wind-induced upwelling at the SBF off Patagonia from daily satellite Chl-a and winds, historical hydrographic observations, cross-shelf Chl-a fluorescence transects from two cruises, and in situ winds and water column structure from a mooring site. Satellite Chl-a composites segregated by along-front wind direction indicate that surface Chl-a is enhanced at the SBF with southerly winds and suppressed with northerly winds. Northerly winds also result in enhanced Chl-a further offshore (˜25-50 km). Synoptic transects as well as mean hydrographic sections segregated by along-front winds show isopycnals tilted upward for southerly winds. Spring observations from the mooring also suggest that southerly winds destratify the water column and northerly winds restratify, in agreement with Ekman transport interacting with the front. Moreover, changes in water column temperature lag along-front wind forcing by 2-4 days. Our results suggest that oscillations in along-front winds, on timescales typical of atmospheric storms (2-10 days), can significantly modulate the upwelling and Chl-a concentrations at the SBF off Patagonia, revealing the importance of wind-induced upwelling for shelf-slope exchange at shelf-break fronts of western boundary currents.
Sensor Buoy System for Monitoring Renewable Marine Energy Resources.
García, Emilio; Quiles, Eduardo; Correcher, Antonio; Morant, Francisco
2018-03-22
In this paper we present a multi-sensor floating system designed to monitor marine energy parameters, in order to sample wind, wave, and marine current energy resources. For this purpose, a set of dedicated sensors to measure the height and period of the waves, wind, and marine current intensity and direction have been selected and installed in the system. The floating device incorporates wind and marine current turbines for renewable energy self-consumption and to carry out complementary studies on the stability of such a system. The feasibility, safety, sensor communications, and buoy stability of the floating device have been successfully checked in real operating conditions.
Sensor Buoy System for Monitoring Renewable Marine Energy Resources
García, Emilio; Morant, Francisco
2018-01-01
In this paper we present a multi-sensor floating system designed to monitor marine energy parameters, in order to sample wind, wave, and marine current energy resources. For this purpose, a set of dedicated sensors to measure the height and period of the waves, wind, and marine current intensity and direction have been selected and installed in the system. The floating device incorporates wind and marine current turbines for renewable energy self-consumption and to carry out complementary studies on the stability of such a system. The feasibility, safety, sensor communications, and buoy stability of the floating device have been successfully checked in real operating conditions. PMID:29565823
Shiu, Henry; Swales, Henry; Van Damn, Case
2015-06-03
Dataset contains MHK Hydrofoils Design and Optimization and CFD Analysis Report for the Aquantis 2.5 MW Ocean Current Generation Device, as well as MHK Hydrofoils Wind Tunnel Test Plan and Checkout Test Report.
NASA Astrophysics Data System (ADS)
Carvalho, David Joao da Silva
The high dependence of Portugal from foreign energy sources (mainly fossil fuels), together with the international commitments assumed by Portugal and the national strategy in terms of energy policy, as well as resources sustainability and climate change issues, inevitably force Portugal to invest in its energetic self-sufficiency. The 20/20/20 Strategy defined by the European Union defines that in 2020 60% of the total electricity consumption must come from renewable energy sources. Wind energy is currently a major source of electricity generation in Portugal, producing about 23% of the national total electricity consumption in 2013. The National Energy Strategy 2020 (ENE2020), which aims to ensure the national compliance of the European Strategy 20/20/20, states that about half of this 60% target will be provided by wind energy. This work aims to implement and optimise a numerical weather prediction model in the simulation and modelling of the wind energy resource in Portugal, both in offshore and onshore areas. The numerical model optimisation consisted in the determination of which initial and boundary conditions and planetary boundary layer physical parameterizations options provide wind power flux (or energy density), wind speed and direction simulations closest to in situ measured wind data. Specifically for offshore areas, it is also intended to evaluate if the numerical model, once optimised, is able to produce power flux, wind speed and direction simulations more consistent with in situ measured data than wind measurements collected by satellites. This work also aims to study and analyse possible impacts that anthropogenic climate changes may have on the future wind energetic resource in Europe. The results show that the ECMWF reanalysis ERA-Interim are those that, among all the forcing databases currently available to drive numerical weather prediction models, allow wind power flux, wind speed and direction simulations more consistent with in situ wind measurements. It was also found that the Pleim-Xiu and ACM2 planetary boundary layer parameterizations are the ones that showed the best performance in terms of wind power flux, wind speed and direction simulations. This model optimisation allowed a significant reduction of the wind power flux, wind speed and direction simulations errors and, specifically for offshore areas, wind power flux, wind speed and direction simulations more consistent with in situ wind measurements than data obtained from satellites, which is a very valuable and interesting achievement. This work also revealed that future anthropogenic climate changes can negatively impact future European wind energy resource, due to tendencies towards a reduction in future wind speeds especially by the end of the current century and under stronger radiative forcing conditions.
Babineau, Kate; Clancy, Luke
2015-06-05
To measure young people's perceptions of tobacco packaging according to two current pieces of legislation: The EU Tobacco Products Directive (TPD) and Ireland's Public Health (Standardisation of Tobacco Products) Act. Within-subject experimental cross-sectional survey of a representative sample of secondary school students. School-based pen and paper survey. 27 secondary schools across Ireland, randomly stratified for size, geographic location, gender, religious affiliation and school-level socioeconomic status. Data were collected between March and May 2014. 1378 fifth year secondary school students aged 16-17 in Ireland. Young people's perceptions of attractiveness, health risk and smoker characteristics of packs according to EU and Irish branding and packaging guidelines. Packs with more branding elements were thought to be healthier than standardised packs for Silk Cut (χ(2)=158.58, p<0.001), Marlboro (χ(2)=113.65, p<0.001), and Benson and Hedges (χ(2)=137.95, p<0.001) brands. Generalized estimating equation binary regressions found that gender was a significant predictor of pack attractiveness for Silk Cut, with females being more likely to find the EU packs attractive (β=-0.45, p=0.007). Gender was a significant predictor for females with regards to the perceived popularity of the Silk Cut brand (β=-0.37, p=0.03). The removal of brand identifiers, including colour, font and embossing, reduces the perceived appeal of cigarette packs for young people across all three tested brands. Packs standardised according to Irish legislation are perceived as less attractive, less healthy and smoked by less popular people than packs which conform to the EU TPD 2014 guidelines. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Patterns and processes in the California Current System
NASA Astrophysics Data System (ADS)
Checkley, David M., Jr.; Barth, John A.
2009-12-01
The California Current System (CCS) is forced by the distribution of atmospheric pressure and associated winds in relation to the west coast of North America. In this paper, we begin with a simplified case of winds and a linear coast, then consider variability characteristic of the CCS, and conclude by considering future change. The CCS extends from the North Pacific Current (∼50°N) to off Baja California, Mexico (∼15-25°N) with a major discontinuity at Point Conception (34.5°N). Variation in atmospheric pressure affects winds and thus upwelling. Coastal, wind-driven upwelling results in nutrification and biological production and a southward coastal jet. Offshore, curl-driven upwelling results in a spatially large, productive habitat. The California Current flows equatorward and derives from the North Pacific Current and the coastal jet. Dominant modes of spatial and temporal variability in physical processes and biological responses are discussed. High surface production results in deep and bottom waters depleted in oxygen and enriched in carbon dioxide. Fishing has depleted demersal stocks more than pelagic stocks, and marine mammals, including whales, are recovering. Krill, squid, and micronekton are poorly known and merit study. Future climate change will differ from past change and thus prediction of the CCS requires an understanding of its dynamics. Of particular concern are changes in winds, stratification, and ocean chemistry.
Day, Ryan; Qu, Xiaotao; Swanson, Rosemarie; Bohannan, Zach; Bliss, Robert
2011-01-01
Abstract Most current template-based structure prediction methods concentrate on finding the correct backbone conformation and then packing sidechains within that backbone. Our packing-based method derives distance constraints from conserved relative packing groups (RPGs). In our refinement approach, the RPGs provide a level of resolution that restrains global topology while allowing conformational sampling. In this study, we test our template-based structure prediction method using 51 prediction units from CASP7 experiments. RPG-based constraints are able to substantially improve approximately two-thirds of starting templates. Upon deeper investigation, we find that true positive spatial constraints, especially those non-local in sequence, derived from the RPGs were important to building nearer native models. Surprisingly, the fraction of incorrect or false positive constraints does not strongly influence the quality of the final candidate. This result indicates that our RPG-based true positive constraints sample the self-consistent, cooperative interactions of the native structure. The lack of such reinforcing cooperativity explains the weaker effect of false positive constraints. Generally, these findings are encouraging indications that RPGs will improve template-based structure prediction. PMID:21210729
Growing a Wind Workforce: The National Wind Energy Skills Assessment Report (Poster)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tegen, S.
This poster summarizes results from the first published investigation into the detailed makeup of the wind energy workforce as well as a glance at the educational infrastructure and training needs of the wind industry. Insights from this research into the domestic wind workforce allow the private sector, educational institutions, and federal and state governments to make better informed workforce-related decisions based on the current data and future projections.
Impact of active and break wind spells on the demand-supply balance in wind energy in India
NASA Astrophysics Data System (ADS)
Kulkarni, Sumeet; Deo, M. C.; Ghosh, Subimal
2018-02-01
With an installed capacity of over 19,000 MW, the wind power currently accounts for almost 70% of the total installed capacity among the renewable energy sector in India. The extraction of wind power mainly depends on prevailing meteorology which is strongly influenced by monsoon variability. The monsoon season is characterized by significant fluctuations in between periods of wet and dry spells. During the dry spells, the demand for power from agriculture and cooling equipment increases, whereas during the wet periods, such demand reduces, although, at the same time, the power supply increases because of strong westerly winds contributing to an enhanced production of wind energy. At this backdrop, we aim to assess the impact of intra-seasonal wind variability on the balance of energy supply and demand during monsoon seasons in India. Further, we explore the probable cause of wind variability by relating it to El Nino events. It is observed that the active and break phases in wind significantly impact the overall wind potential output. Although the dry spells are generally found to reduce the overall wind potential, their impact on the potential seems to have declined after the year 2000. The impact of meteorological changes on variations in wind power studied in this work should find applications typically in taking investment decisions on conventional generation facilities, like thermal, which are currently used to maintain the balance of power supply and demand.
Foundations for offshore wind turbines.
Byrne, B W; Houlsby, G T
2003-12-15
An important engineering challenge of today, and a vital one for the future, is to develop and harvest alternative sources of energy. This is a firm priority in the UK, with the government setting a target of 10% of electricity from renewable sources by 2010. A component central to this commitment will be to harvest electrical power from the vast energy reserves offshore, through wind turbines or current or wave power generators. The most mature of these technologies is that of wind, as much technology transfer can be gained from onshore experience. Onshore wind farms, although supplying 'green energy', tend to provoke some objections on aesthetic grounds. These objections can be countered by locating the turbines offshore, where it will also be possible to install larger capacity turbines, thus maximizing the potential of each wind farm location. This paper explores some civil-engineering problems encountered for offshore wind turbines. A critical component is the connection of the structure to the ground, and in particular how the load applied to the structure is transferred safely to the surrounding soil. We review previous work on the design of offshore foundations, and then present some simple design calculations for sizing foundations and structures appropriate to the wind-turbine problem. We examine the deficiencies in the current design approaches, and the research currently under way to overcome these deficiencies. Designs must be improved so that these alternative energy sources can compete economically with traditional energy suppliers.
Probability Density Functions of the Solar Wind Driver of the Magnetopshere-Ionosphere System
NASA Astrophysics Data System (ADS)
Horton, W.; Mays, M. L.
2007-12-01
The solar-wind driven magnetosphere-ionosphere system is a complex dynamical system in that it exhibits (1) sensitivity to initial conditions; (2) multiple space-time scales; (3) bifurcation sequences with hysteresis in transitions between attractors; and (4) noncompositionality. This system is modeled by WINDMI--a network of eight coupled ordinary differential equations which describe the transfer of power from the solar wind through the geomagnetic tail, the ionosphere, and ring current in the system. The model captures both storm activity from the plasma ring current energy, which yields a model Dst index result, and substorm activity from the region 1 field aligned current, yielding model AL and AU results. The input to the model is the solar wind driving voltage calculated from ACE solar wind parameter data, which has a regular coherent component and broad-band turbulent component. Cross correlation functions of the input-output data time series are computed and the conditional probability density function for the occurrence of substorms given earlier IMF conditions are derived. The model shows a high probability of substorms for solar activity that contains a coherent, rotating IMF with magnetic cloud features. For a theoretical model of the imprint of solar convection on the solar wind we have used the Lorenz attractor (Horton et al., PoP, 1999, doi:10.10631.873683) as a solar wind driver. The work is supported by NSF grant ATM-0638480.
Falabella, Steven; Meyer, Glenn A; Tang, Vincent; Guethlein, Gary
2014-06-10
A two-phase mixed media insulator having a dielectric fluid filling the interstices between macro-sized dielectric beads packed into a confined volume, so that the packed dielectric beads inhibit electro-hydrodynamically driven current flows of the dielectric liquid and thereby increase the resistivity and breakdown strength of the two-phase insulator over the dielectric liquid alone. In addition, an electrical apparatus incorporates the two-phase mixed media insulator to insulate between electrical components of different electrical potentials. And a method of electrically insulating between electrical components of different electrical potentials fills a confined volume between the electrical components with the two-phase dielectric composite, so that the macro dielectric beads are packed in the confined volume and interstices formed between the macro dielectric beads are filled with the dielectric liquid.
Ray tracing method for simulation of laser beam interaction with random packings of powders
NASA Astrophysics Data System (ADS)
Kovalev, O. B.; Kovaleva, I. O.; Belyaev, V. V.
2018-03-01
Selective laser sintering is a technology of rapid manufacturing of a free form that is created as a solid object by selectively fusing successive layers of powder using a laser. The motivation of this study is due to the currently insufficient understanding of the processes and phenomena of selective laser melting of powders whose time scales differ by orders of magnitude. To construct random packings from mono- and polydispersed solid spheres, the algorithm of their generation based on the discrete element method is used. A numerical method of ray tracing is proposed that is used to simulate the interaction of laser radiation with a random bulk packing of spherical particles and to predict the optical properties of the granular layer, the extinction and absorption coefficients, depending on the optical properties of a powder material.
Cycle life test of secondary spacecraft cells
NASA Technical Reports Server (NTRS)
Harkness, J. D.
1980-01-01
The results of the life cycling program on rechargeable calls are reported. Information on required data, the use of which the data will be put, application details, including orbital description, charge control methods, load rquirements, etc., are given. Cycle tests were performed on 660 sealed, nickel cadmium cells. The cells consisted of seven sample classifications ranging form 3.0 to 20 amp. hours. Nickel cadmium, silver cadmium, and silver zinc sealed cells, excluding synchronous orbit and accelerated test packs were added. The capacities of the nickel cadmium cells, the silver cadmium and the silver zinc cells differed in range of amp hrs. The cells were cylced under different load, charge control, and temperature conditions. All cell packs are recharged by use of a pack voltage limit. All charging is constant current until the voltage limit is reached.
A multiple-fan active control wind tunnel for outdoor wind speed and direction simulation
NASA Astrophysics Data System (ADS)
Wang, Jia-Ying; Meng, Qing-Hao; Luo, Bing; Zeng, Ming
2018-03-01
This article presents a new type of active controlled multiple-fan wind tunnel. The wind tunnel consists of swivel plates and arrays of direct current fans, and the rotation speed of each fan and the shaft angle of each swivel plate can be controlled independently for simulating different kinds of outdoor wind fields. To measure the similarity between the simulated wind field and the outdoor wind field, wind speed and direction time series of two kinds of wind fields are recorded by nine two-dimensional ultrasonic anemometers, and then statistical properties of the wind signals in different time scales are analyzed based on the empirical mode decomposition. In addition, the complexity of wind speed and direction time series is also investigated using multiscale entropy and multivariate multiscale entropy. Results suggest that the simulated wind field in the multiple-fan wind tunnel has a high degree of similarity with the outdoor wind field.
Wind Resource Assessment of Gujarat (India)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Draxl, C.; Purkayastha, A.; Parker, Z.
India is one of the largest wind energy markets in the world. In 1986 Gujarat was the first Indian state to install a wind power project. In February 2013, the installed wind capacity in Gujarat was 3,093 MW. Due to the uncertainty around existing wind energy assessments in India, this analysis uses the Weather Research and Forecasting (WRF) model to simulate the wind at current hub heights for one year to provide more precise estimates of wind resources in Gujarat. The WRF model allows for accurate simulations of winds near the surface and at heights important for wind energy purposes.more » While previous resource assessments published wind power density, we focus on average wind speeds, which can be converted to wind power densities by the user with methods of their choice. The wind resource estimates in this study show regions with average annual wind speeds of more than 8 m/s.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
Severe wind and snow storms hit the Pacific Northwest region on December 14 – 15, 2006, following severe flooding during the past few days. The severe weather resulted in major power outages through the region. At peak there were 1.8 million customers without power which included BC Hydro in Canada. Currently, there are over 1.5 million outages in the region as a result of the Pacific Northwest Storms. This represents about 42 percent of customers in affected utility service areas in Oregon and Washington. See table below. Because the current wind and snow storms are coming on the heels ofmore » extensive flooding in the region, electric utilities are experiencing damage. Wind gusts reached close to 100 mph in some areas of the region. The storm is expected to bring its strong winds and heavy snow into Idaho, Montana and Wyoming Friday and into the weekend. There are currently no reported major impacts to the petroleum and natural gas infrastructure.« less
Predicting wind-driven waves in small reservoirs
USDA-ARS?s Scientific Manuscript database
The earthen levees commonly used for irrigation reservoirs are subjected to significant embankment erosion due to wind-generated waves. The design of bank protection measures relies on adequate prediction of wave characteristics based on wind conditions and fetch length. Current formulations are ba...
Satellite Observations of Imprint of Oceanic Current on Wind Stress by Air-Sea Coupling.
Renault, Lionel; McWilliams, James C; Masson, Sebastien
2017-12-18
Mesoscale eddies are present everywhere in the ocean and partly determine the mean state of the circulation and ecosystem. The current feedback on the surface wind stress modulates the air-sea transfer of momentum by providing a sink of mesoscale eddy energy as an atmospheric source. Using nine years of satellite measurements of surface stress and geostrophic currents over the global ocean, we confirm that the current-induced surface stress curl is linearly related to the current vorticity. The resulting coupling coefficient between current and surface stress (s τ [N s m -3 ]) is heterogeneous and can be roughly expressed as a linear function of the mean surface wind. s τ expresses the sink of eddy energy induced by the current feedback. This has important implications for air-sea interaction and implies that oceanic mean and mesoscale circulations and their effects on surface-layer ventilation and carbon uptake are better represented in oceanic models that include this feedback.
The effects of wind disturbance on temperate rain forest structure and dynamics of southeast Alaska.
Gregory J. Nowacki; Marc G. Kramer
1998-01-01
Wind disturbance plays a fundamental role in shaping forest dynamics in southeast Alaska. Recent studies have increased our appreciation for the effects of wind at both large and small scales. Current thinking is that wind disturbance characteristics change over a continuum dependent on landscape features (e.g., exposure, landscape position, topography). Data modeling...
Global Network of Slow Solar Wind
NASA Technical Reports Server (NTRS)
Crooker, N. U.; Antiochos, S. K.; Zhao, X.; Neugebauer, M.
2012-01-01
The streamer belt region surrounding the heliospheric current sheet (HCS) is generally treated as the primary or sole source of the slow solar wind. Synoptic maps of solar wind speed predicted by the Wang-Sheeley-Arge model during selected periods of solar cycle 23, however, show many areas of slow wind displaced from the streamer belt. These areas commonly have the form of an arc that is connected to the streamer belt at both ends. The arcs mark the boundaries between fields emanating from different coronal holes of the same polarity and thus trace the paths of belts of pseudostreamers, i.e., unipolar streamers that form over double arcades and lack current sheets. The arc pattern is consistent with the predicted topological mapping of the narrow open corridor or singular separator line that must connect the holes and, thus, consistent with the separatrix-web model of the slow solar wind. Near solar maximum, pseudostreamer belts stray far from the HCS-associated streamer belt and, together with it, form a global-wide web of slow wind. Recognition of pseudostreamer belts as prominent sources of slow wind provides a new template for understanding solar wind stream structure, especially near solar maximum.
Wind-US Users Guide Version 4.0
NASA Technical Reports Server (NTRS)
Yoder, Dennis A.
2016-01-01
Wind-US is a computational platform which may be used to numerically solve various sets of equations governing physical phenomena. Currently, the code supports the solution of the Euler and Navier-Stokes equations of fluid mechanics, along with supporting equation sets governing turbulent and chemically reacting flows. Wind-US is a product of the NPARC Alliance, a partnership between the NASA Glenn Research Center (GRC) and the Arnold Engineering Development Complex (AEDC) dedicated to the establishment of a national, applications-oriented flow simulation capability. The Boeing Company has also been closely associated with the Alliance since its inception, and represents the interests of the NPARC User's Association. The "Wind-US User's Guide" describes the operation and use of Wind-US, including: a basic tutorial; the physical and numerical models that are used; the boundary conditions; monitoring convergence; the files that are read and/or written; parallel execution; and a complete list of input keywords and test options. For current information about Wind-US and the NPARC Alliance, please see the Wind-US home page at http://www.grc.nasa.gov/WWW/winddocs/ and the NPARC Alliance home page at http://www.grc.nasa.gov/WWW/wind/.
The SPARC Intercomparison of Middle Atmosphere Climatologies
NASA Technical Reports Server (NTRS)
Randel, William; Fleming, Eric; Geller, Marvin; Gelman, Mel; Hamilton, Kevin; Karoly, David; Ortland, Dave; Pawson, Steve; Swinbank, Richard; Udelhofen, Petra
2003-01-01
Our current confidence in 'observed' climatological winds and temperatures in the middle atmosphere (over altitudes approx. 10-80 km) is assessed by detailed intercomparisons of contemporary and historic data sets. These data sets include global meteorological analyses and assimilations, climatologies derived from research satellite measurements, and historical reference atmosphere circulation statistics. We also include comparisons with historical rocketsonde wind and temperature data, and with more recent lidar temperature measurements. The comparisons focus on a few basic circulation statistics, such as temperature, zonal wind, and eddy flux statistics. Special attention is focused on tropical winds and temperatures, where large differences exist among separate analyses. Assimilated data sets provide the most realistic tropical variability, but substantial differences exist among current schemes.
NASA Technical Reports Server (NTRS)
1989-01-01
When Enerpro, Inc. president, Frank J. Bourbeau, attempted to file a patent on a system for synchronizing a wind generator to the electric utility grid, he discovered Marshall Space Flight Center's Frank Nola's power factor controller. Bourbeau advanced the technology and received a NASA license and a patent for his Auto Synchronous Controller (ASC). The ASC reduces generator "inrush current," which occurs when large generators are abruptly brought on line. It controls voltage so the generator is smoothly connected to the utility grid when it reaches its synchronous speed, protecting the components from inrush current damage. Generator efficiency is also increased in light winds by applying lower than rated voltage. Wind energy is utilized to drive turbines to generate electricity for utility companies.
An expert system for wind shear avoidance
NASA Technical Reports Server (NTRS)
Stengel, Robert F.; Stratton, D. Alexander
1990-01-01
A study of intelligent guidance and control concepts for protecting against the adverse effects of wind shear during aircraft takeoffs and landings is being conducted, with current emphasis on developing an expert system for wind shear avoidance. Principal objectives are to develop methods for assessing the likelihood of wind shear encounter (based on real-time information in the cockpit), for deciding what flight path to pursue (e.g., takeoff abort, landing go-around, or normal climbout or glide slope), and for using the aircraft's full potential for combating wind shear. This study requires the definition of both deterministic and statistical techniques for fusing internal and external information , for making go/no-go decisions, and for generating commands to the manually controlled flight. The program has begun with the development of the WindShear Safety Advisor, an expert system for pilot aiding that is based on the FAA Windshear Training Aid; a two-volume manual that presents an overview , pilot guide, training program, and substantiating data provides guidelines for this initial development. The WindShear Safety Advisor expert system currently contains over 200 rules and is coded in the LISP programming language.
Wind impact on the Black Sea ecosystem
NASA Astrophysics Data System (ADS)
Stanichny, Sergey; Ratner, Yuriy; Shokurov, Mike; Stanychna, Rimma; Soloviev, Dmytro; Burdyugov, Vyacheslav
2010-05-01
Combination of the recent satellite and meteorological data for the regional investigation allowed to describe new features of the processes in marine ecosystem and detect some relations with wind variability for different time scales. Next topics are highlighted in presentation: 1. Inter-annual variability of the wind stress curl over the Black Sea. Shift in the atmospheric processes after 2003 year and related variations in chlorophyll concentration and intensity of the mesoscale currents. 2. Like-tropical cyclone in September 2005 and its impact o the Black Sea upper layer. 3. Strong storm November 11, 2007 and oil pollutions of the Kerch Strait. 4. Relation of the Danube waters transport with wind fields for summer 2007 and 2008. 5. "Valley" wind in the Eastern part of the Black Sea and its impact on the Rim current formation. 6. Low wind conditions and blue -green algae bloom. NCEP, SKIRON and MHI MM5 wind data together with AVHRR, MODIS, MERIS, ETM+, QuikSCAT, ASAR (ESA) satellite data were used for investigation. Work was done with support of the SESAME FP7, "Stable Ecosystem" and Operational Oceanography NASU projects.
NASA Astrophysics Data System (ADS)
Sherwood, C. R.; Butman, B.; Cacchione, D. A.; Drake, D. E.; Gross, T. F.; Sternberg, R. W.; Wiberg, P. L.; Williams, A. J.
1994-08-01
Measurements of currents and light transmission were made at bottom tripods and moorings arrayed across the northern California continental shelf along the Coastal Ocean Dynamics Experiment (CODE) "C" transect as part of the 1990-1991 Sediment Transport Events on Shelves and Slopes (STRESS) experiment. In combination with meteorological and wave data from the National Data Buoy Center Buoy 46013, these measurements provide information about the physical forcing and resultant resuspension and transport of bottom material between 21 November and 8 March. Sixteen events were identified in the wave, wind and current-meter records for this period. Only two were local storms with southerly winds, but they caused about half of the seasonal net transport. Seven were swell events that combined long-period waves generated by distant storms with local currents. At the 90-m site, swells interacted with the mean northward flow to produce northward transport. During six northerly wind events, upwelling-favorable winds often were sufficient to slow or reverse the mean northward flow and thus caused southward transport. A single current event, which produced moderate southward transport, was observed at the 130-m site. Net transport during the winter experiment was offshore at all sites, northward at the inner- and mid-shelf sites, but southward at the outer-shelf site. The results suggest that local storms with southerly winds may dominate seasonal transport, as on the Washington shelf, but significant transport also can occur during fair weather and during periods of northerly winds.
The Extent to Which Dayside Reconnection Drives Field-Aligned Currents During Substorms
NASA Astrophysics Data System (ADS)
Forsyth, C.; Shortt, M. W.; Coxon, J.; Rae, J.; Freeman, M. P.; Kalmoni, N. M. E.; Jackman, C. M.; Anderson, B. J.
2016-12-01
Field-aligned currents, also known as Birkeland currents, are the agents by which energy and momentum is transferred to the ionosphere from the magnetosphere and solar wind. In order to understand this coupling, it is necessary to analyze the variations in these current systems with respect to the main energy sources of the solar wind and substorms. In this study, we perform a superposed epoch analysis of field-aligned currents determined by the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) project with respect to substorm expansion phase onsets identified using the Substorm Onsets and Phases from Indices of the Electrojet (SOPHIE) technique. We examine the total upward and downward currents separately in the noon, dusk, dawn and midnight sectors. Our results show that the dusk and dawn currents have up to a 66% linear correlated with the dayside reconnection rate estimated from solar wind measurements, whereas the noon and midnight currents are not. The noon currents show little or no variation throughout the substorm cycle. The midnight currents follows the dusk currents up to 20 min before onset, after which the midnight current increases more rapidly and exponentially. At substorm onset, the exponential growth rate increases. While the midnight field-aligned currents grow exponentially after substorm onset, the auroral indices vary with a 1/6th power law. Overall, our results show that the growth and decay rates of the Region 1 and 2 current systems, which are strongest at dawn and dusk, are directly driven by the solar wind, whereas the growth and decay rates of the substorm current system, which are dominant at midnight, act independently of the upstream driver.
The influence of surface waves on water circulation in a mid-Atlantic continental shelf region
NASA Technical Reports Server (NTRS)
Whitlock, C. H.; Talay, T. A.
1974-01-01
The importance of wave-induced currents in different weather conditions and water depths (18.3 m and 36.6 m) is assessed in a mid-Atlantic continental-shelf region. A review of general circulation conditions is conducted. Factors which perturb the general circulation are examined using analytic techniques and limited experimental data. Actual wind and wave statistics for the region are examined. Relative magnitudes of the various currents are compared on a frequency of annual occurrence basis. Results indicated that wave-induced currents are often the same order of magnitude as other currents in the region and become more important at higher wind and wave conditions. Wind-wave and ocean-swell characteristics are among those parameters which must be monitored for the analytical computation of continental-shelf circulation.
Device for balancing parallel strings
Mashikian, Matthew S.
1985-01-01
A battery plant is described which features magnetic circuit means in association with each of the battery strings in the battery plant for balancing the electrical current flow through the battery strings by equalizing the voltage across each of the battery strings. Each of the magnetic circuit means generally comprises means for sensing the electrical current flow through one of the battery strings, and a saturable reactor having a main winding connected electrically in series with the battery string, a bias winding connected to a source of alternating current and a control winding connected to a variable source of direct current controlled by the sensing means. Each of the battery strings is formed by a plurality of batteries connected electrically in series, and these battery strings are connected electrically in parallel across common bus conductors.
Van der Merwe, Deon; Price, Kevin P
2015-03-27
Harmful algal blooms (HABs) degrade water quality and produce toxins. The spatial distribution of HAbs may change rapidly due to variations wind, water currents, and population dynamics. Risk assessments, based on traditional sampling methods, are hampered by the sparseness of water sample data points, and delays between sampling and the availability of results. There is a need for local risk assessment and risk management at the spatial and temporal resolution relevant to local human and animal interactions at specific sites and times. Small, unmanned aircraft systems can gather color-infrared reflectance data at appropriate spatial and temporal resolutions, with full control over data collection timing, and short intervals between data gathering and result availability. Data can be interpreted qualitatively, or by generating a blue normalized difference vegetation index (BNDVI) that is correlated with cyanobacterial biomass densities at the water surface, as estimated using a buoyant packed cell volume (BPCV). Correlations between BNDVI and BPCV follow a logarithmic model, with r(2)-values under field conditions from 0.77 to 0.87. These methods provide valuable information that is complimentary to risk assessment data derived from traditional risk assessment methods, and could help to improve risk management at the local level.
Van der Merwe, Deon; Price, Kevin P.
2015-01-01
Harmful algal blooms (HABs) degrade water quality and produce toxins. The spatial distribution of HAbs may change rapidly due to variations wind, water currents, and population dynamics. Risk assessments, based on traditional sampling methods, are hampered by the sparseness of water sample data points, and delays between sampling and the availability of results. There is a need for local risk assessment and risk management at the spatial and temporal resolution relevant to local human and animal interactions at specific sites and times. Small, unmanned aircraft systems can gather color-infrared reflectance data at appropriate spatial and temporal resolutions, with full control over data collection timing, and short intervals between data gathering and result availability. Data can be interpreted qualitatively, or by generating a blue normalized difference vegetation index (BNDVI) that is correlated with cyanobacterial biomass densities at the water surface, as estimated using a buoyant packed cell volume (BPCV). Correlations between BNDVI and BPCV follow a logarithmic model, with r2-values under field conditions from 0.77 to 0.87. These methods provide valuable information that is complimentary to risk assessment data derived from traditional risk assessment methods, and could help to improve risk management at the local level. PMID:25826055
Nearshore circulation on a sea breeze dominated beach during intense wind events
NASA Astrophysics Data System (ADS)
Torres-Freyermuth, Alec; Puleo, Jack A.; DiCosmo, Nick; Allende-Arandía, Ma. Eugenia; Chardón-Maldonado, Patricia; López, José; Figueroa-Espinoza, Bernardo; de Alegria-Arzaburu, Amaia Ruiz; Figlus, Jens; Roberts Briggs, Tiffany M.; de la Roza, Jacobo; Candela, Julio
2017-12-01
A field experiment was conducted on the northern Yucatan coast from April 1 to April 12, 2014 to investigate the role of intense wind events on coastal circulation from the inner shelf to the swash zone. The study area is characterized by a micro-tidal environment, low-energy wave conditions, and a wide and shallow continental shelf. Furthermore, easterly trade winds, local breezes, and synoptic-scale events, associated with the passage of cold-fronts known as Nortes, are ubiquitous in this region. Currents were measured concurrently at different cross-shore locations during both local and synoptic-scale intense wind events to investigate the influence of different forcing mechanisms (i.e., large-scale currents, winds, tides, and waves) on the nearshore circulation. Field observations revealed that nearshore circulation across the shelf is predominantly alongshore-directed (westward) during intense winds. However, the mechanisms responsible for driving instantaneous spatial and temporal current variability depend on the weather conditions and the across-shelf location. During local strong sea breeze events (W > 10 m s-1 from the NE) occurring during spring tide, westward circulation is controlled by the tides, wind, and waves at the inner-shelf, shallow waters, and inside the surf/swash zone, respectively. The nearshore circulation is relaxed during intense land breeze events (W ≈ 9 m s-1 from the SE) associated with the low atmospheric pressure system that preceded a Norte event. During the Norte event (Wmax≈ 15 m s-1 from the NNW), westward circulation dominated outside the surf zone and was correlated to the Yucatan Current, whereas wave breaking forces eastward currents inside the surf/swash zone. The latter finding implies the existence of large alongshore velocity shear at the offshore edge of the surf zone during the Norte event, which enhances mixing between the surf zone and the inner shelf. These findings suggest that both sea breezes and Nortes play an important role in sediment and pollutant transport along/across the nearshore of the Yucatan shelf.
National-Scale Wind Resource Assessment for Power Generation (Presentation)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Baring-Gould, E. I.
2013-08-01
This presentation describes the current standards for conducting a national-scale wind resource assessment for power generation, along with the risk/benefit considerations to be considered when beginning a wind resource assessment. The presentation describes changes in turbine technology and viable wind deployment due to more modern turbine technology and taller towers and shows how the Philippines national wind resource assessment evolved over time to reflect changes that arise from updated technologies and taller towers.
The most intense electric currents in turbulent high speed solar wind
NASA Astrophysics Data System (ADS)
Podesta, J. J.
2017-12-01
Theory and simulations suggest that dissipation of turbulent energy in collisionless astrophysical plasmas occurs most rapidly in spatial regions where the current density is most intense. To advance understanding of plasma heating by turbulent dissipation in the solar corona and solar wind, it is of interest to characterize the properties of plasma regions where the current density takes exceptionally large values and to identify the operative dissipation processes. In the solar wind, the curl of the magnetic field cannot be measured using data from a single spacecraft, however, a suitable proxy for this quantity can be constructed from the spatial derivative of the magnetic field along the flow direction of the plasma. This new approach is used to study the properties of the most intense current carrying structures in a high speed solar wind stream near 1 AU. In this study, based on 11 Hz magnetometer data from the WIND spacecraft, the spatial resolution of the proxy technique is approximately equal to the proton inertial length. Intense current sheets or current carrying structures were identified as events where the magnitude of the current density exceeds μ+5σ, where μ and σ are the mean and standard deviation of the magnitude of the current density (or its proxy), respectively. Statistical studies show (1) the average size of these 5σ events is close to the smallest resolvable scale in the data set, the proton inertial length; (2) the linear distance between neighboring events follows a power law distribution; and (3) the average peak current density of 5σ events is around 1 pA/cm2. The analysis techniques used in these studies have been validated using simulated spacecraft data from three dimensional hybrid simulations which show that results based on the analysis of the proxy are qualitatively and quantitatively similar to results based on the analysis of the true current density.
NASA Astrophysics Data System (ADS)
Khan, Md. Arif-Ul Islam; Das, Swapnil; Dey, Saikat
2017-12-01
: Economic growth and energy demand are intertwined. Therefore, one of the most important concerns of the government and in the world is the need for energy security. Currently, the world relies on coal, crude oil and natural gas for energy generati on. However, the energy crisis together with climate change and depletion of oil have become major concerns to all countries. Therefore, alternative energy resources such as wind energy attracted interest from both public and private sectors to invest in energy generation from this source extensively. Both Vertical and Horizontal axis wind turbine can be used for this purpose. But, Horizontal axis is the most promising between them due to its efficiency and low expense. Bangladesh being a tropical country does have a lot of wind flow at different seasons of the year. However, there are some windy locations in which wind energy projects could be feasible. In this project a detailed review of the current st ate-of-art for wind turbine blade design is presented including theoretical maximum efficiency, Horizontal Axis Wind Turbine (HAWT) blade design, simulation power and COP values for different blade material. By studying previously collected data on the wind resources available in B angladesh at present and by analyzing this data, this paper will discuss the scope of wind energy in Bangladesh.
Toward Robust and Efficient Climate Downscaling for Wind Energy
NASA Astrophysics Data System (ADS)
Vanvyve, E.; Rife, D.; Pinto, J. O.; Monaghan, A. J.; Davis, C. A.
2011-12-01
This presentation describes a more accurate and economical (less time, money and effort) wind resource assessment technique for the renewable energy industry, that incorporates innovative statistical techniques and new global mesoscale reanalyzes. The technique judiciously selects a collection of "case days" that accurately represent the full range of wind conditions observed at a given site over a 10-year period, in order to estimate the long-term energy yield. We will demonstrate that this new technique provides a very accurate and statistically reliable estimate of the 10-year record of the wind resource by intelligently choosing a sample of ±120 case days. This means that the expense of downscaling to quantify the wind resource at a prospective wind farm can be cut by two thirds from the current industry practice of downscaling a randomly chosen 365-day sample to represent winds over a "typical" year. This new estimate of the long-term energy yield at a prospective wind farm also has far less statistical uncertainty than the current industry standard approach. This key finding has the potential to reduce significantly market barriers to both onshore and offshore wind farm development, since insurers and financiers charge prohibitive premiums on investments that are deemed to be high risk. Lower uncertainty directly translates to lower perceived risk, and therefore far more attractive financing terms could be offered to wind farm developers who employ this new technique.
Surface and airborne evidence for plumes and winds on triton
Hansen, C.J.; McEwen, A.S.; Ingersoll, A.P.; Terrile, R.J.
1990-01-01
Aeolian features on Triton that were imaged during the Voyager Mission have been grouped. The term "aeolian feature" is broadly defined as features produced by or blown by the wind, including surface and airborne materials. Observations of the latitudinal distributions of the features probably associated with current activity (known plumes, crescent streaks, fixed terminator clouds, and limb haze with overshoot) all occur from latitude -37?? to latitude -62??. Likely indicators of previous activity (dark surface streaks) occur from latitude -5?? to -70??, but are most abundant from -15?? to -45??, generally north of currently active features. Those indicators which give information on wind direction and speed have been measured. Wind direction is a function of altitude. The predominant direction of the surface wind streaks is found to be between 40?? and 80?? measured clockwise from north. The average orientation of streaks in the northeast quadrant is 59??. Winds at 1- to 3-kilometer altitude are eastward, while those at >8 kilometers blow west.
NASA Astrophysics Data System (ADS)
Day, Jason
This study examines the wind energy planning frameworks from ten North American jurisdictions, drawing important lessons that British Columbia could use to build on its current model which has been criticized for its limited scope and restriction of local government powers. This study contributes to similar studies conducted by Kimrey (2006), Longston (2006), and Eriksen (2009). This study concludes that inclusion of wind resource zones delineated through strategic environmental assessment, programme assessment, and conducting research-oriented studies could improve the current British Columbia planning framework. The framework should also strengthen its bat impact assessment practices and incorporate habitat compensation. This research also builds upon Rosenberg's (2008) wind energy planning framework typologies. I conclude that the typology utilized in Texas should be employed in British Columbia in order to facilitate utilizing wind power. The only adaptation needed is the establishment of a cross-jurisdictional review committee for project assessment to address concerns about local involvement and site-specific environmental and social concerns.
NASA Astrophysics Data System (ADS)
Wang, Han; Hu, Zhi-qiang; Meng, Xiang-yin
2018-06-01
Both numerical calculation and model test are important techniques to study and forecast the dynamic responses of the floating offshore wind turbine (FOWT). However, both the methods have their own limitations at present. In this study, the dynamic responses of a 5 MW OC3 spar-type floating wind turbine designed for a water depth of 200 m are numerically investigated and validated by a 1:50 scaled model test. Moreover, the discrepancies between the numerical calculations and model tests are obtained and discussed. According to the discussions, it is found that the surge and pitch are coupled with the mooring tensions, but the heave is independent of them. Surge and pitch are mainly induced by wave under wind wave conditions. Wind and current will induce the low-frequency average responses, while wave will induce the fluctuation ranges of the responses. In addition, wave will induce the wavefrequency responses but wind and current will restrain the ranges of the responses.
NASA Astrophysics Data System (ADS)
Artigao, Estefania; Honrubia-Escribano, Andres; Gomez-Lazaro, Emilio
2017-11-01
Operation and maintenance (O&M) of wind turbines is recently becoming the spotlight in the wind energy sector. While wind turbine power capacities continue to increase and new offshore developments are being installed, O&M costs keep raising. With the objective of reducing such costs, the new trends are moving from corrective and preventive maintenance toward predictive actions. In this scenario, condition monitoring (CM) has been identified as the key to achieve this goal. The induction generator of a wind turbine is a major contributor to failure rates and downtime where doubly-fed induction generators (DFIG) are the dominant technology employed in variable speed wind turbines. The current work presents the analysis of an in-service DFIG. A one-year measurement campaign has been used to perform the study. Several signal processing techniques have been applied and the optimal method for CM has been identified. A diagnosis has been reached, the DFIG under study shows potential gearbox damage.
Monitoring Wind Turbine Loading Using Power Converter Signals
NASA Astrophysics Data System (ADS)
Rieg, C. A.; Smith, C. J.; Crabtree, C. J.
2016-09-01
The ability to detect faults and predict loads on a wind turbine drivetrain's mechanical components cost-effectively is critical to making the cost of wind energy competitive. In order to investigate whether this is possible using the readily available power converter current signals, an existing permanent magnet synchronous generator based wind energy conversion system computer model was modified to include a grid-side converter (GSC) for an improved converter model and a gearbox. The GSC maintains a constant DC link voltage via vector control. The gearbox was modelled as a 3-mass model to allow faults to be included. Gusts and gearbox faults were introduced to investigate the ability of the machine side converter (MSC) current (I q) to detect and quantify loads on the mechanical components. In this model, gearbox faults were not detectable in the I q signal due to shaft stiffness and damping interaction. However, a model that predicts the load change on mechanical wind turbine components using I q was developed and verified using synthetic and real wind data.
NASA Technical Reports Server (NTRS)
Nance, Donald K.; Reed, Darren K.
2011-01-01
During the recent successful launch of the Ares I-X Flight Test Vehicle, aeroacoustic data was gathered at fifty-seven locations along the vehicle as part of the Developmental Flight Instrumentation. Several of the Ares I-X aeroacoustic measurements were placed to duplicate measurement locations prescribed in pre-flight, sub-scale wind tunnel tests. For these duplicated measurement locations, comparisons have been made between aeroacoustic data gathered during the ascent phase of the Ares I-X flight test and wind tunnel test data. These comparisons have been made at closely matching flight conditions (Mach number and vehicle attitude) in order to preserve a one-to-one relationship between the flight and wind tunnel data. These comparisons and the current wind tunnel to flight scaling methodology are presented and discussed. The implications of using wind tunnel test data scaled under the current methodology to predict conceptual launch vehicle aeroacoustic environments are also discussed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Boissonnade, A; Hossain, Q; Kimball, J
Since the mid-l980's, assessment of the wind and tornado risks at the Department of Energy (DOE) high and moderate hazard facilities has been based on the straight wind/tornado hazard curves given in UCRL-53526 (Coats, 1985). These curves were developed using a methodology that utilized a model, developed by McDonald, for severe winds at sub-tornado wind speeds and a separate model, developed by Fujita, for tornado wind speeds. For DOE sites not covered in UCRL-53526, wind and tornado hazard assessments are based on the criteria outlined in DOE-STD-1023-95 (DOE, 1996), utilizing the methodology in UCRL-53526; Subsequent to the publication of UCRL53526,more » in a study sponsored by the Nuclear Regulatory Commission (NRC), the Pacific Northwest Laboratory developed tornado wind hazard curves for the contiguous United States, NUREG/CR-4461 (Ramsdell, 1986). Because of the different modeling assumptions and underlying data used to develop the tornado wind information, the wind speeds at specified exceedance levels, at a given location, based on the methodology in UCRL-53526, are different than those based on the methodology in NUREG/CR-4461. In 1997, Lawrence Livermore National Laboratory (LLNL) was funded by the DOE to review the current methodologies for characterizing tornado wind hazards and to develop a state-of-the-art wind/tornado characterization methodology based on probabilistic hazard assessment techniques and current historical wind data. This report describes the process of developing the methodology and the database of relevant tornado information needed to implement the methodology. It also presents the tornado wind hazard curves obtained from the application of the method to DOE sites throughout the contiguous United States.« less
Upwelling Response to Hurricane Isaac in Geostrophic Oceanic Vortices
NASA Astrophysics Data System (ADS)
Jaimes, B.; Shay, L. K.; Brewster, J. K.; Schuster, R.
2013-05-01
As a tropical cyclone (TC) moves over the ocean, the cyclonic curl of the wind stress produces a region of upwelling waters under the TC center that is compensated by downwelling waters at regions outside the center. Direct measurements conducted during hurricane Rita and recent numerical studies indicate that this is not necessarily the case when TCs move over geostrophic oceanic features, where its background relative vorticity impacts wind-driven horizontal current divergence and the upwelling velocity. Modulation of the upwelling response in these energetic oceanic regimes impacts vertical mixing across the oceanic mixed layer base, air-sea fluxes into the atmosphere, and ultimately storm intensity. As part of NOAA Intensity Forecasting Experiment, an experiment was conducted during the passage of TC Isaac over the energetic geostrophic eddy field in the Gulf of Mexico in August 2012. Expendable bathythermographs, current profilers, and conductivity-temperature-depth probes were deployed in Isaac from NOAA WP-3D aircraft during four in-storm flights to measure oceanic variability and its impact on TC-driven upwelling and surface fluxes of heat and momentum. During intensification to hurricane, the cyclonic curl of the wind stress of Isaac extended over a region of more than 300 km in diameter (4 to 5 times the radius of maximum winds). Isaac's center moved over a cold cyclonic feature, while its right and left sides moved over warm anticyclones. Contrasting upwelling and downwelling regimes developed inside the region of cyclonic curl of the wind stress. Both positive (upwelling) and negative (downwelling) vertical displacements of 40 and 60 m, respectively, were measured inside the region of cyclonic curl of the wind stress, which are between 3 to 4 times larger than predicted vertical displacements for a quiescent ocean based on scaling arguments. Oceanic mixed layer (OML) currents of 0.2 to 0.7 m s-1 were measured, which are about 50% smaller than the expected velocity response under quiescent oceanic conditions. Although OML currents were measured inside the core of cyclonic curl of the wind stress, their orientation is not consistent with horizontally divergent flows typically found in upwelling regimes under TC centers. Theoretical predictions that consider background relative vorticity effects on the upwelling response mimic the contrasting upwelling/downwelling regimes inside the region of cyclonic curl of the wind stress. These results point to an important modulation of the OML current and upwelling response by background oceanic flows, where the upwelling velocity is a function of the curl of wind-intensified pre-storm geostrophic currents, rather than just a function of the curl of the wind stress. Thus, properly initializing temperature and salinity fields in numerical models is needed to accurately represent these oceanic processes in coupled forecast models.
Modeling of the Coupled Magnetospheric and Neutral Wind Dynamos
NASA Technical Reports Server (NTRS)
Thayer, Jeffrey P.
1997-01-01
Over the past four years of funding, SRI, in collaboration with the University of Texas at Dallas, has been involved in assessing the influence of thermospheric neutral winds on the electric field and current systems at high latitudes. The initial direction of the project was to perform a set of numerical experiments concerning the contribution of the magnetospheric and neutral wind dynamo processes, under specific boundary conditions, to the polarization electric field and/or the field-aligned current distribution at high latitudes. To facilitate these numerical experiments we developed a numerical scheme that relied on using output from the NCAR Thermosphere-Ionosphere General Circulation Model (NCAR-TIGCM), expanding them in the form of spherical harmonics and solving the dynamo equations spectrally. Once initial calculations were completed, it was recognized that the neutral wind contribution could be significant but its actual contribution to the electric field or currents depended strongly on the generator properties of the magnetosphere. Solutions to this problem are not unique because of the unknown characteristics of the magnetospheric generator, therefore the focus was on two limiting cases. One limiting case was to consider the magnetosphere as a voltage generator delivering a fixed voltage to the high-latitude ionosphere and allowing for the neutral wind dynamo to contribute only to the current system. The second limiting case was to consider the magnetosphere as a current generator and allowing for the neutral wind dynamo to contribute only to the generation of polarization electric fields. This work was completed and presented at the l994 Fall AGU meeting. The direction of the project then shifted to applying the Poynting flux concept to the high-latitude ionosphere. This concept was more attractive as it evaluated the influence of neutral winds on the high-latitude electrodynamics without actually having to determine the generator characteristics of the magnetosphere. The influence of the neutral wind was then determined not by estimating how much electric potential or current density it provides, but by determining the contribution of the neutral wind to the net electromagnetic energy transferred between the ionosphere and magnetosphere. The estimate of the net electromagnetic energy transfer and the role of the neutral winds proves to be a more fundamental quantity in studies of magnetosphere- ionosphere coupling also showed that by using electric and magnetic field measurements from the HILAT satellite, the Poynting flux could be a measurable quantity from polar-orbiting, low- altitude spacecraft. Through collaboration with Dr. Heelis and others at UTD and their expertise of the electric field measurements on the DE-B satellite, an extensive analysis was planned to determine the Poynting flux from the DE-B measurements in combination with a modeling effort to help interpret the observations taking into account the coupled magnetosphere-ionosphere.
Jacox, Michael G.; Hazen, Elliott L.; Bograd, Steven J.
2016-01-01
In Eastern Boundary Current systems, wind-driven upwelling drives nutrient-rich water to the ocean surface, making these regions among the most productive on Earth. Regulation of productivity by changing wind and/or nutrient conditions can dramatically impact ecosystem functioning, though the mechanisms are not well understood beyond broad-scale relationships. Here, we explore bottom-up controls during the California Current System (CCS) upwelling season by quantifying the dependence of phytoplankton biomass (as indicated by satellite chlorophyll estimates) on two key environmental parameters: subsurface nitrate concentration and surface wind stress. In general, moderate winds and high nitrate concentrations yield maximal biomass near shore, while offshore biomass is positively correlated with subsurface nitrate concentration. However, due to nonlinear interactions between the influences of wind and nitrate, bottom-up control of phytoplankton cannot be described by either one alone, nor by a combined metric such as nitrate flux. We quantify optimal environmental conditions for phytoplankton, defined as the wind/nitrate space that maximizes chlorophyll concentration, and present a framework for evaluating ecosystem change relative to environmental drivers. The utility of this framework is demonstrated by (i) elucidating anomalous CCS responses in 1998–1999, 2002, and 2005, and (ii) providing a basis for assessing potential biological impacts of projected climate change. PMID:27278260
Heat Stroke: Role of the Systemic Inflammatory Response
2010-06-01
data indicate that current clinical markers of heat stroke recovery may not adequately reflect heat stroke recovery in all cases. Currently heat stroke...cause of mortality, and recent experimental data indicate that current clinical markers of heat stroke recovery may not adequately reflect heat stroke...hyperthermia in patients was regarded as a compensatory peripheral vasoconstriction response to cooling of the skin surface with ice packs, whereas
NASA Astrophysics Data System (ADS)
Vieira da Silva, Guilherme; Toldo, Elírio E., Jr.; Klein, Antonio H. da F.; Short, Andrew D.
2018-07-01
Investigations of headland sand bypassing are still an under-reported subject in the literature. This paper aims to understand the contribution of currents forced by different mechanisms such as tides, winds (i.e. local wind acting over the ocean surface generating currents, without considering wave generation) and waves (as they approach/break on the coast) to headland sand bypassing. The study was carried out in an area comprising a series of seven headlands with varying wave exposure due to changes in shoreline orientation and increasing tidal influence close to a relatively large bay. This paper uses a calibrated and validated process-based model (Delft3D) to simulate a series of scenarios including spring and neap tides during flood and ebb conditions and a range of wind and wave scenarios that encompass both average and extreme conditions. The results indicate that waves are the main driving force for the headland bypassing as they transport sand at rates two orders of magnitude higher than tide- or wind-driven sediment transport. The tide-driven currents can only transport sediment during spring tides in locations where the currents are intensified. It is also demonstrated that the wave direction plays an important role in sediment transport. In exposed areas with larger headlands a combination of wave directions is required to first transport sediment offshore (out of the beach) and secondly to transport sediment alongshore and back to the next beach. Whereas in areas with little variation in wave direction exposure, the same oblique wave direction is responsible for the entire headland bypassing process. This is the first time the contribution of tide-, winds- and wave-generated sediment transport to headland bypassing have been studied.
Saturation of the Electric Field Transmitted to the Magnetosphere
NASA Technical Reports Server (NTRS)
Lyatsky, Wladislaw; Khazanov, George V.; Slavin, James A.
2010-01-01
We reexamined the processes leading to saturation of the electric field, transmitted into the Earth's ionosphere from the solar wind, incorporating features of the coupled system previously ignored. We took into account that the electric field is transmitted into the ionosphere through a region of open field lines, and that the ionospheric conductivity in the polar cap and auroral zone may be different. Penetration of the electric field into the magnetosphere is linked with the generation of the Alfven wave, going out from the ionosphere into the solar wind and being coupled with the field-aligned currents at the boundary of the open field limes. The electric field of the outgoing Alfven wave reduces the original electric field and provides the saturation effect in the electric field and currents during strong geomagnetic disturbances, associated with increasing ionospheric conductivity. The electric field and field-aligned currents of this Alfven wave are dependent on the ionospheric and solar wind parameters and may significantly affect the electric field and field-aligned currents, generated in the polar ionosphere. Estimating the magnitude of the saturation effect in the electric field and field-aligned currents allows us to improve the correlation between solar wind parameters and resulting disturbances in the Earth's magnetosphere.
NASA Astrophysics Data System (ADS)
Toporkov, D. M.; Vialcev, G. B.
2017-10-01
The implementation of parallel branches is a commonly used manufacturing method of the realizing of fractional slot concentrated windings in electrical machines. If the rotor eccentricity is enabled in a machine with parallel branches, the equalizing currents can arise. The simulation approach of the equalizing currents in parallel branches of an electrical machine winding based on magnetic field calculation by using Finite Elements Method is discussed in the paper. The high accuracy of the model is provided by the dynamic improvement of the inductances in the differential equation system describing a machine. The pre-computed table flux linkage functions are used for that. The functions are the dependences of the flux linkage of parallel branches on the branches currents and rotor position angle. The functions permit to calculate self-inductances and mutual inductances by partial derivative. The calculated results obtained for the electric machine specimen are presented. The results received show that the adverse combination of design solutions and the rotor eccentricity leads to a high value of the equalizing currents and windings heating. Additional torque ripples also arise. The additional ripples harmonic content is not similar to the cogging torque or ripples caused by the rotor eccentricity.
Pompe, E; Bartstra, J; Verhaar, H J; de Koning, H J; van der Aalst, C M; Oudkerk, M; Vliegenthart, R; Lammers, J-W J; de Jong, P A; Mohamed Hoesein, F A A
2017-04-01
Cigarette smoking negatively affects bone quality and increases fracture risk. Little is known on the effect of smoking cessation and computed tomography (CT)-derived bone mineral density (BMD) decline in the spine. We evaluated the association of current and former smoking with BMD decline after 3-year follow-up. Male current and former smokers participating in a lung cancer screening trial who underwent baseline and 3-year follow-up CT were included. BMD was measured by manual placement of a region of interest in the first lumbar vertebra and expressed in Hounsfield Unit (HU). Multiple linear regression analysis was used to evaluate the association between pack years smoked and smoking status with BMD decline. 408 participants were included with median (25th-75th percentile) age of 59.4 (55.9-63.5) years. At the start of the study, 197 (48.3%) participants were current smokers and 211 (51.7%) were former smokers and had a similar amount of pack years. Current smokers had quit smoking for 6 (4-8) years prior to inclusion. There was no difference in BMD between current and former smokers at baseline (109±34 HU vs. 108±32 HU, p=0.96). At 3-year follow-up, current smokers had a mean BMD decline of -3±13 HU (p=0.001), while BMD in former smokers did not change as compared to baseline (1±13 HU, p=0.34). After adjustment for BMD at baseline and body mass index, current smoking was independently associated with BMD decline (-3.8 HU, p=0.003). Age, pack years, and the presence of a fracture at baseline did not associate with BMD decline. Current smokers showed a more rapid BMD decline over a 3-year period compared to former smokers. This information might be important to identify subjects at risk for osteoporosis and emphasizes the importance of smoking cessation in light of BMD decline. Copyright © 2017 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Ding, Y.; Yu, J.; Bao, X.; Yao, Z.
2016-02-01
The characteristics and dynamical mechanism of summer-time coastal current over the northwestern South China Sea (NSCS) shelf have been investigated based on a high resolution unstructured-grid finite volume community ocean model (FVCOM). Model-data comparison demonstrates that model well resolves the coastal dynamics over the NSCS shelf. The coastal current on the NSCS shelf is intensively influenced by monsoon and freshwater discharge of the Pearl River. Strong southwesterly wind drive the coastal current northeastward. However, under weak southwest monsoon, the coastal current west of Pearl River estuary (PRE) advects toward southwest, and splits into two parts when reaching east of the Qiongzhou Strait, with one branch entering the Gulf of Tonkin through the Qiongzhou Strait, transporting low salinity water into the Gulf of Tonkin, and the other part flows cyclonic and interacts with the northeastward current around southeast of Hainan Island, forming a cyclonic eddy east of the Qiongzhou Strait. A variety of model experiments focused on freshwater discharge, wind forcing, tidal rectification, and stratification are performed to study the physical mechanism of the southwestward coastal current which is usually against the summer wind. Process-oriented experiment results indicate that the southwest monsoon and freshwater discharge are important factors influencing the formation of southwestward coastal current during summer. Momentum balance analysis suggests that the along shelf barotropic pressure gradient due to the Pearl River discharge and wind forcing provides the main driving force for the southwestward coastal current.
NASA Technical Reports Server (NTRS)
Chen, D. Y.; Owen, H. A., Jr.; Wilson, T. G.
1980-01-01
This paper presents an algorithm and equations for designing the energy-storage reactor for dc-to-dc converters which are constrained to operate in the discontinuous-reactor-current mode. This design procedure applied to the three widely used single-winding configurations: the voltage step-up, the current step-up, and the voltage-or-current step-up converters. A numerical design example is given to illustrate the use of the design algorithm and design equations.
Max, Wendy; Sung, Hai-Yen; Lightwood, James
2013-05-01
This study presents estimates of the impact of changes in California tobacco control funding on healthcare expenditures for 2012-2016 under four funding scenarios. Smoking prevalence is projected using a cointegrated time series regression model. Smoking-attributable healthcare expenditures are estimated with econometric models that use a prevalence-based annual cost approach and an excess cost methodology. If tobacco control spending in California remains at the current level of 5 cents per pack (base case), smoking prevalence will increase from 12.2% in 2011 to 12.7% in 2016. If funding is cut in half, smoking prevalence will increase to 12.9% in 2016 and smoking-attributable healthcare expenditures will be $307 million higher over this time period than in the base case. If the tobacco tax is increased by $1.00 per pack with 20 cents per pack allocated to tobacco control, smoking prevalence will fall to 10.4% in 2016 and healthcare expenditures between 2012 and 2016 will be $3.3 billion less than in the base case. If funding is increased to the Centers for Disease Control and Prevention recommended level, smoking prevalence will fall to 10.6% in 2016 and there will be savings in healthcare expenditures of $4.7 billion compared to the base case due to the large reduction in heavy smoking prevalence. California's highly successful tobacco control program will become less effective over time because inflation is eroding the 5 cents per pack currently allocated to tobacco control activities. More aggressive action needs to be taken to reduce smoking prevalence and healthcare expenditures in the future.
Fechter, Dominik; Storch, Ilse
2014-01-01
Due to legislative protection, many species, including large carnivores, are currently recolonizing Europe. To address the impending human-wildlife conflicts in advance, predictive habitat models can be used to determine potentially suitable habitat and areas likely to be recolonized. As field data are often limited, quantitative rule based models or the extrapolation of results from other studies are often the techniques of choice. Using the wolf (Canis lupus) in Germany as a model for habitat generalists, we developed a habitat model based on the location and extent of twelve existing wolf home ranges in Eastern Germany, current knowledge on wolf biology, different habitat modeling techniques and various input data to analyze ten different input parameter sets and address the following questions: (1) How do a priori assumptions and different input data or habitat modeling techniques affect the abundance and distribution of potentially suitable wolf habitat and the number of wolf packs in Germany? (2) In a synthesis across input parameter sets, what areas are predicted to be most suitable? (3) Are existing wolf pack home ranges in Eastern Germany consistent with current knowledge on wolf biology and habitat relationships? Our results indicate that depending on which assumptions on habitat relationships are applied in the model and which modeling techniques are chosen, the amount of potentially suitable habitat estimated varies greatly. Depending on a priori assumptions, Germany could accommodate between 154 and 1769 wolf packs. The locations of the existing wolf pack home ranges in Eastern Germany indicate that wolves are able to adapt to areas densely populated by humans, but are limited to areas with low road densities. Our analysis suggests that predictive habitat maps in general, should be interpreted with caution and illustrates the risk for habitat modelers to concentrate on only one selection of habitat factors or modeling technique. PMID:25029506
NLCC controller for SEPIC-based micro-wind energy conversion system
NASA Astrophysics Data System (ADS)
Justin Nayagam, Brintha Jane; Sathi, Rama Reddy; Olimuthu, Divya
2017-04-01
The growth of the power industry is gaining greater momentum as the usage of the non-conventional energy sources that include fuel, solar, and wind energies, increases. Wind energy conversion systems (WECSs) are gaining more popularity and are expected to be able to control the power at the output. This paper describes the current control (CC), non-linear carrier charge control (NLCCC), and fuzzy logic control (FLC) applied to the single-ended primary inductor converter (SEPIC)-based WECS. The current controller has an inherent overcurrent protection with better line noise rejection. The pulses for the switch of the SEPIC are obtained by comparing the current flowing through it with the virtual current reference. FLC is also investigated for the micro-wind energy conversion system (μWECS), since it improves the damping characteristics of WECS over a wide range of operating points. This cannot attain the unity power factor rectification. In this paper, NLCCC is proposed for high-power factor rectifier-based SEPIC in continuous conduction mode (CCM) for μWECS. The proposed converter provides an output voltage with low input current ripple due to the presence of the inductor at the input side. By comparing the signal proportional to the integral of switch current with a periodic non-linear carrier wave, the duty ratio of the converter switch is determined for the NLCC controller. By selecting the shape of the periodic non-linear carrier wave the input-line current can be made to follow the input-line voltage. This work employs a parabolic carrier waveform generator. The output voltage is regulated for changes in the wind speed. The results obtained prove the effectiveness of the NLCC controller in improving the power factor.
Evidence of active region imprints on the solar wind structure
NASA Technical Reports Server (NTRS)
Hick, P.; Jackson, B. V.
1995-01-01
A common descriptive framework for discussing the solar wind structure in the inner heliosphere uses the global magnetic field as a reference: low density, high velocity solar wind emanates from open magnetic fields, with high density, low speed solar wind flowing outward near the current sheet. In this picture, active regions, underlying closed magnetic field structures in the streamer belt, leave little or no imprint on the solar wind. We present evidence from interplanetary scintillation measurements of the 'disturbance factor' g that active regions play a role in modulating the solar wind and possibly contribute to the solar wind mass output. Hence we find that the traditional view of the solar wind, though useful in understanding many features of solar wind structure, is oversimplified and possibly neglects important aspects of solar wind dynamics
Spatial mapping and attribution of Wyoming wind turbines
O'Donnell, Michael S.; Fancher, Tammy S.
2010-01-01
This Wyoming wind-turbine data set represents locations of wind turbines found within Wyoming as of August 1, 2009. Each wind turbine is assigned to a wind farm. For each turbine, this report contains information about the following: potential megawatt output, rotor diameter, hub height, rotor height, land ownership, county, wind farm power capacity, the number of units currently associated with its wind farm, the wind turbine manufacturer and model, the wind farm developer, the owner of the wind farm, the current purchaser of power from the wind farm, the year the wind farm went online, and the status of its operation. Some attributes are estimates based on information that was obtained through the American Wind Energy Association and miscellaneous online reports. The locations are derived from August 2009 true-color aerial photographs made by the National Agriculture Imagery Program; the photographs have a positional accuracy of approximately ?5 meters. The location of wind turbines under construction during the development of this data set will likely be less accurate than the location of turbines already completed. The original purpose for developing the data presented here was to evaluate the effect of wind energy development on seasonal habitat used by greater sage-grouse. Additionally, these data will provide a planning tool for the Wyoming Landscape Conservation Initiative Science Team and for other wildlife- and habitat-related projects underway at the U.S. Geological Survey's Fort Collins Science Center. Specifically, these data will be used to quantify disturbance of the landscape related to wind energy as well as quantifying indirect disturbances to flora and fauna. This data set was developed for the 2010 project 'Seasonal predictive habitat models for greater sage-grouse in Wyoming.' This project's spatially explicit seasonal distribution models of sage-grouse in Wyoming will provide resource managers with tools for conservation planning. These specific data are being used for assessing the effect of disturbance resulting from wind energy development within Wyoming on sage-grouse populations.
What Do Cigarette Pack Colors Communicate to Smokers in the U.S.?
Bansal-Travers, Maansi; O’Connor, Richard; Fix, Brian V.; Cummings, K. Michael
2011-01-01
Background New legislation in the U.S. prohibits tobacco companies from labelling cigarette packs with terms such as ‘light,’ ‘mild,’ or ‘low’ after June 2010. However, experience from countries that have removed these descriptors suggests different terms, colors, or numbers communicating the same messages may replace them. Purpose The main purpose of this study was to examine how cigarette pack colors are perceived by smokers to correspond to different descriptive terms. Methods Newspaper advertisements and craigslist.org postings directed interested current smokers to a survey website. Eligible participants were shown an array of six cigarette packages (altered to remove all descriptive terms) and asked to link package images with their corresponding descriptive terms. Participants were then asked to identify which pack in the array they would choose if they were concerned with health, tar, nicotine, image, and taste. Results A total of 193 participants completed the survey from February to March 2008 (data were analyzed from May 2008 through November 2010). Participants were more accurate in matching descriptors to pack images for Marlboro brand cigarettes than for unfamiliar Peter Jackson brand (sold in Australia). Smokers overwhelmingly chose the ‘whitest’ pack if they were concerned about health, tar, and nicotine. Conclusions Smokers in the U.S. associate brand descriptors with colors. Further, white packaging appears to most influence perceptions of safety. Removal of descriptor terms but not the associated colors will be insufficient in eliminating misperceptions about the risks from smoking communicated to smokers through packaging. PMID:21565662
What do cigarette pack colors communicate to smokers in the U.S.?
Bansal-Travers, Maansi; O'Connor, Richard; Fix, Brian V; Cummings, K Michael
2011-06-01
New legislation in the U.S. prohibits tobacco companies from labeling cigarette packs with terms such as light, mild, or low after June 2010. However, experience from countries that have removed these descriptors suggests that different terms, colors, or numbers communicating the same messages may replace them. The main purpose of this study was to examine how cigarette pack colors are perceived by smokers to correspond to different descriptive terms. Newspaper advertisements and CraigsList.org postings directed interested current smokers to a survey website. Eligible participants were shown an array of six cigarette packages (altered to remove all descriptive terms) and asked to link package images with their corresponding descriptive terms. Participants were then asked to identify which pack in the array they would choose if they were concerned with health, tar, nicotine, image, and taste. A total of 193 participants completed the survey from February to March 2008 (data were analyzed from May 2008 through November 2010). Participants were more accurate in matching descriptors to pack images for Marlboro brand cigarettes than for unfamiliar Peter Jackson brand (sold in Australia). Smokers overwhelmingly chose the "whitest" pack if they were concerned about health, tar, and nicotine. Smokers in the U.S. associate brand descriptors with colors. Further, white packaging appears to most influence perceptions of safety. Removal of descriptor terms but not the associated colors will be insufficient in eliminating misperceptions about the risks from smoking communicated to smokers through packaging. Copyright © 2011 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.
Stochastic Quantitative Reasoning for Autonomous Mission Planning
2014-04-09
points. Figure 4: Linear interpolation Table 1: Wind speed prediction information (ID:0-2 for Albany, ID:3-5 for Pittston, and ID:6-8 for JFK Airport ID...Pittston, and JFK Airport in Table 1, how can we estimate a reasonable wind speed for the current location at the current time? Figure 5: Example
33 CFR 164.35 - Equipment: All vessels.
Code of Federal Regulations, 2013 CFR
2013-07-01
...: (i) Calm weather—wind 10 knots or less, calm sea; (ii) No current; (iii) Deep water conditions—water...: (1) Calm weather—wind 10 knots or less, calm sea; (2) No current; (3) Water depth twice the vessel's..., permanently displayed on the navigating bridge and in the steering gear compartment. (l) An indicator readable...
33 CFR 164.35 - Equipment: All vessels.
Code of Federal Regulations, 2014 CFR
2014-07-01
...: (i) Calm weather—wind 10 knots or less, calm sea; (ii) No current; (iii) Deep water conditions—water...: (1) Calm weather—wind 10 knots or less, calm sea; (2) No current; (3) Water depth twice the vessel's..., permanently displayed on the navigating bridge and in the steering gear compartment. (l) An indicator readable...
33 CFR 164.35 - Equipment: All vessels.
Code of Federal Regulations, 2010 CFR
2010-07-01
... to alter course 90 degrees with maximum rudder angle and constant power settings, for either full and...: (i) Calm weather—wind 10 knots or less, calm sea; (ii) No current; (iii) Deep water conditions—water...: (1) Calm weather—wind 10 knots or less, calm sea; (2) No current; (3) Water depth twice the vessel's...
33 CFR 164.35 - Equipment: All vessels.
Code of Federal Regulations, 2011 CFR
2011-07-01
... to alter course 90 degrees with maximum rudder angle and constant power settings, for either full and...: (i) Calm weather—wind 10 knots or less, calm sea; (ii) No current; (iii) Deep water conditions—water...: (1) Calm weather—wind 10 knots or less, calm sea; (2) No current; (3) Water depth twice the vessel's...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tegen, Suzanne
This presentation provides an overview of findings from a report published in 2016 by researchers at the National Renewable Energy Laboratory, An Initial Evaluation of Siting Considerations on Current and Future Wind Deployment. The presentation covers the background for research, the Energy Department's Wind Vision, research methods, siting considerations, the wind project deployment process, and costs associated with siting considerations.
Integrated Wind Power Planning Tool
NASA Astrophysics Data System (ADS)
Rosgaard, Martin; Giebel, Gregor; Skov Nielsen, Torben; Hahmann, Andrea; Sørensen, Poul; Madsen, Henrik
2013-04-01
This poster presents the current state of the public service obligation (PSO) funded project PSO 10464, with the title "Integrated Wind Power Planning Tool". The goal is to integrate a mesoscale numerical weather prediction (NWP) model with purely statistical tools in order to assess wind power fluctuations, with focus on long term power system planning for future wind farms as well as short term forecasting for existing wind farms. Currently, wind power fluctuation models are either purely statistical or integrated with NWP models of limited resolution. Using the state-of-the-art mesoscale NWP model Weather Research & Forecasting model (WRF) the forecast error is sought quantified in dependence of the time scale involved. This task constitutes a preparative study for later implementation of features accounting for NWP forecast errors in the DTU Wind Energy maintained Corwind code - a long term wind power planning tool. Within the framework of PSO 10464 research related to operational short term wind power prediction will be carried out, including a comparison of forecast quality at different mesoscale NWP model resolutions and development of a statistical wind power prediction tool taking input from WRF. The short term prediction part of the project is carried out in collaboration with ENFOR A/S; a Danish company that specialises in forecasting and optimisation for the energy sector. The integrated prediction model will allow for the description of the expected variability in wind power production in the coming hours to days, accounting for its spatio-temporal dependencies, and depending on the prevailing weather conditions defined by the WRF output. The output from the integrated short term prediction tool constitutes scenario forecasts for the coming period, which can then be fed into any type of system model or decision making problem to be solved. The high resolution of the WRF results loaded into the integrated prediction model will ensure a high accuracy data basis is available for use in the decision making process of the Danish transmission system operator. The need for high accuracy predictions will only increase over the next decade as Denmark approaches the goal of 50% wind power based electricity in 2025 from the current 20%.
NASA Astrophysics Data System (ADS)
Ehrke, Elizabeth
Nearly every aspect of human existence relies on energy in some way. Most of this energy is currently derived from fossil fuel resources. Increasing energy demands coupled with environmental and national security concerns have facilitated the move towards renewable energy sources. Biofuels like corn ethanol are one of the ways the U.S. has significantly reduced petroleum consumption. However, the large energy requirement of corn ethanol limits the net benefit of the fuel. Using renewable energy sources to produce ethanol can greatly improve its economic and environmental benefits. The main purpose of this study was to model the useful energy received from a solar thermal array and a wind turbine at various locations to determine the feasibility of applying these technologies at ethanol plants around the country. The model calculates thermal energy received from a solar collector array and electricity generated by a wind turbine utilizing various input data to characterize the equipment. Project cost and energy rate inputs are used to evaluate the profitability of the solar array or wind turbine. The current state of the wind and solar markets were examined to give an accurate representation of the economics of each industry. Eighteen ethanol plant locations were evaluated for the viability of a solar thermal array and/or wind turbine. All ethanol plant locations have long payback periods for solar thermal arrays, but high natural gas prices significantly reduce this timeframe. Government incentives will be necessary for the economic feasibility of solar thermal arrays. Wind turbines can be very profitable for ethanol plants in the Midwest due to large wind resources. The profitability of wind power is sensitive to regional energy prices. However, government incentives for wind power do not significantly change the economic feasibility of a wind turbine. This model can be used by current or future ethanol facilities to investigate or begin the planning process for a solar thermal array or wind turbine. The model is meant to aide in the planning stages of a renewable energy project, and advanced investigation will be needed to move forward with that project.
Passive magnetic bearing for a motor-generator
Post, Richard F [Walnut Creek, CA
2006-07-18
Conductive lap windings are interleaved with conventional loops in the stator of a motor-generator. The rotor provides magnetic induction lines that, when rotated, cut across the lap windings and the loops. When the rotor is laterally displaced from its equilibrium axis of rotation, its magnetic lines of induction induce a current in the interleaved lap windings. The induced current interacts with the magnetic lines of induction of the rotor in accordance with Lenz's law to generate a radial force that returns the rotor to its equilibrium axis of rotation.
Morphodynamics of intertidal bars near a seawall on a macrotidal beach, Wissant Bay, northern France
NASA Astrophysics Data System (ADS)
Sedrati, M.; Anthony, E.
2009-04-01
Several studies on beaches with intertidal bar-trough (ridge-and-runnel) systems in settings with relatively large tidal ranges (> 3 m) have focused on cross-shore bar mobility; however a few recent studies have drawn attention to the potential role of longshore transport induced by a mix of wave-tide and wind-forced longshore currents in the morphodynamics of the bars and troughs. The aim of this paper is to briefly highlight the relationship between wind-forced currents on the shallow intertidal zone and rapid intertidal bar-trough morphological response on a macrotidal beach. Fieldwork was conduced on Wissant beach, Wissant Bay, northern France, from 7 to 23 March, 2006. During the experiment, the beach (oriented NE-SW) exhibited three intertidal bar-trough systems and the upper bar was directly attached to a seawall. Seven digital elevation models (DEMs) were generated from high-resolution topographic surveys. Hydrodynamic measurements were obtained from five currentmeters (2 S4 and 3 ADCP) deployed on the bars crests and on the upper beach trough. Wave characteristics were obtained from the measured time series by spectral analysis using Fast Fourier Transforms. Wind speed and direction on the beach were measured using a portable weather station. The mean wind speed and directions averaged every three hours highlight closely-spaced high-energy events during the experiment, with long phases of significant lateral wind stress (NE to ENE). The measured waves and currents showed rapid and strong response to both the changes in wind speed and direction. Longshore currents measured during the experiment on the upper intertidal bar-trough system showed a clear SW flow pattern in response to NE to ENE wind approach directions while the currents in the lower intertidal zone flowed northeastward during the flood, following the coastline, and southwestward during the ebb in response to the tidal current modulation. Strong longshore migration of the upper intertidal bar to the SW was observed during the course of this fieldwork. This longshore migration was attended by erosion of the upper beach in the northeast and accretion in the southwest. Bars in the lower intertidal zone were relatively stable. The SW migration process of the upper intertidal bar during the experiment occurred at rates that fluctuated with the intensity of the longshore current. The net beach volume over the experiment was quite stable, thus showing that morphological change, notably bar migration, simply reflected adjustments to hydrodynamic forcing without new sand inputs into the system. The findings of the present study suggest that cross-shore currents are subordinate to, and may even be mitigated by, wind-forced longshore flows on this beach. The importance of longshore transport on the upper beach is due to hydrodynamic forcing over the shallow depth, with the seawall playing a probable additional longshore canalization effect. Longshore transport should be considered as an essential element of the morphodynamics of bar-trough beaches subject to large tidal ranges and significant lateral wind stress.
Consumer support for healthy food and drink vending machines in public places.
Carrad, Amy M; Louie, Jimmy Chun-Yu; Milosavljevic, Marianna; Kelly, Bridget; Flood, Victoria M
2015-08-01
To investigate the feasibility of introducing vending machines for healthier food into public places, and to examine the effectiveness of two front-of-pack labelling systems in the vending machine context. A survey was conducted with 120 students from a university and 120 employees, patients and visitors of a hospital in regional NSW, Australia. Questions explored vending machine use, attitudes towards healthier snack products and price, and the performance of front-of-pack labelling formats for vending machine products. Most participants viewed the current range of snacks and drinks as "too unhealthy" (snacks 87.5%; drinks 56.7%). Nuts and muesli bars were the most liked healthier vending machine snack. Higher proportions of participants were able to identify the healthier snack in three of the five product comparisons when products were accompanied with any type of front-of-pack label (all p<0.01); however, participants were less likely to be able to identify the healthier product in the drinks comparison when a front-of-pack guide was present. Respondents were interested in a range of healthier snacks for vending machines. Front-of-pack label formats on vending machines may assist consumers to identify healthier products. Public settings, such as universities and hospitals, should support consumers to make healthy dietary choices by improving food environments. © 2015 Public Health Association of Australia.
Eddy-current system for the vibration-testing of blades
Jacobs, Martin E.
1977-01-01
This invention is an improved system for the vibration-testing of cantilevered non-ferrous articles by inducing eddy currents therein. The principal advantage of the system is that relatively little heat is generated in the article being vibrated. Thus, a more accurate measurement of the fatigue characteristics of the article is obtained. Furthermore, the generation of relatively little heat in the blade permits tests to be conducted in low-pressure atmospheres simulating certain actual processes environments. Heat-generation in the vibrated article is minimized by utilizing eddy currents which are generated by an electromagnet whose magnetic field varies but does not change polarity. The typical winding for the electromagnet is excited with pulsating d.c. That is, the winding is alternately charged by connecting it across a d.c. power supply and then discharged by connecting it across a circuit for receiving current generated in the winding by self-induction. Preferably, the discharge circuit is designed so that the waveform of the discharging current approximates that of the charging current.
Wind Tunnel and Hover Performance Test Results for Multicopter UAS Vehicles
NASA Technical Reports Server (NTRS)
Russell, Carl R.; Jung, Jaewoo; Willink, Gina; Glasner, Brett
2016-01-01
There is currently a lack of published data for the performance of multicopter unmanned aircraft system (UAS) vehicles, such as quadcopters and octocopters, often referred to collectively as drones. With the rapidly increasing popularity of multicopter UAS, there is interest in better characterizing the performance of this type of aircraft. By studying the performance of currently available vehicles, it will be possible to develop models for vehicles at this scale that can accurately predict performance and model trajectories. This paper describes a wind tunnel test that was recently performed in the U.S. Army's 7- by 10-ft Wind Tunnel at NASA Ames Research Center. During this wind tunnel entry, five multicopter UAS vehicles were tested to determine forces and moments as well as electrical power as a function of wind speed, rotor speed, and vehicle attitude. The test is described here in detail, and a selection of the key results from the test is presented.
Solar wind and coronal structure near sunspot minimum - Pioneer and SMM observations from 1985-1987
NASA Technical Reports Server (NTRS)
Mihalov, J. D.; Barnes, A.; Hundhausen, A. J.; Smith, E. J.
1990-01-01
Changes in solar wind speed and magnetic polarity observed at the Pioneer spacecraft are discussed here in terms of the changing magnetic geometry implied by SMM coronagraph observations over the period 1985-1987. The pattern of recurrent solar wind streams, the long-term average speed, and the sector polarity of the interplanetary magnetic field all changed in a manner suggesting both a temporal variation, and a changing dependence on heliographic latitude. Coronal observations during this epoch show a systematic variation in coronal structure and the magnetic structure imposed on the expanding solar wind. These observations suggest interpretation of the solar wind speed variations in terms of the familiar model where the speed increases with distance from a nearly flat interplanetary current sheet, and where this current sheet becomes aligned with the solar equatorial plane as sunspot minimum approaches, but deviates rapidly from that orientation after minimum.
Enhanced low-temperature performance of a multicell LiSOC1sub2 battery
NASA Astrophysics Data System (ADS)
Street, H. K.
A battery pack with a long life, low current, multitap power supply utilizing lithium thionyl chloride cells (LTC) is described. The battery was developed to provide power to a portable solid state recording accelerometer. The battery pack utilizes 10 Li/SOC12 type LTC-7PN keeper 2 cells. These cells are wired in a series parallel arrangement to provide two 6 volt outputs and two negative 3 volt outputs with a single common. Four 301 K ohm resistors are internally mounted and wired to permit an optional continuous 12 microampere current drain from the cells to eliminate voltage delay effects at very low temperatures. The prewired assembly is encapsulated, using Stepen Foam H-102N rigid polyurethane 2 lbs/ft(3) foam, molded to a density of 4 lbs/ft(3).
Analysis of the internal temperature of the cells in a battery pack during SOC balancing
NASA Astrophysics Data System (ADS)
Mizanur, R.; Rashid, M. M.; Rahman, A.; Zahirul Alam, A. H. M.; Ihsan, S.; Mollik, M. S.
2017-03-01
Lithium-ion batteries are more suitable for the application of electric vehicle due to high energy and power density compared to other rechargeable batteries. However, the battery pack temperature has a great impact on the overall performance, cycle life, normal charging-discharging behaviour and even safety. During rapid charge transferring process, the internal temperature may exceed its allowable limit (460C). In this paper, an analysis of internal temperature during charge balancing and discharging conditions is presented. Specific interest is paid to the effects of temperature on the different rate of ambient temperature and discharging current. Matlab/Simulink Li-ion battery model and quasi-resonant converter base balancing system are used to study the temperature effect. Rising internal temperature depends on the rate of balancing current and ambient temperature found in the simulation results.
Pelvic packing or angiography: competitive or complementary?
Suzuki, Takashi; Smith, Wade R; Moore, Ernest E
2009-04-01
Pelvic angiography is an established technique that has evolved into a highly effective means of controlling arterial pelvic haemorrhage. The current dominant paradigm for haemodynamically unstable patients with pelvic fractures is angiographic management combined with mechanical stabilisation of the pelvis. However, an effective rapid screening tool for arterial bleeding in pelvic fracture patients has yet to be identified. There is also no precise way to determine the major source of bleeding responsible for haemodynamic instability. In many pelvic fracture patients, bleeding is from venous lacerations which are not effectively treated with angiography to fractured bony surfaces. Modern pelvic packing consists of time-saving and minimally invasive techniques which appear to result in effective control of the haemorrhage via tamponade. This review article focuses on the recent body of knowledge on angiography and pelvic packing. We propose the optimal role for each modality in trauma centres.
NASA Astrophysics Data System (ADS)
Michaud, Héloïse; Leredde, Yann; Estournel, Claude; Berthebaud, Éric; Marsaleix, Patrick
2013-09-01
While oceanic circulation in the Gulf of Lion (GoL) has often been studied in calm weather or with northerly winds (Tramontane or Mistral) through observations and numerical circulation models, few studies have focused on southeasterly storm events. Yet, correct representation of the circulation during storms is crucial if the suspension of sediments is to be correctly modelled throughout the Gulf. The purpose of this paper is to describe the hydrodynamics in the Gulf of Aigues-Mortes (NW of the GoL) during the storm of 18 February 2007 by using a set of data from an ADCP station placed at a depth of 65 m on the sea bed off the coast at Sète, supplemented by the ocean circulation model SYMPHONIE. This storm was characterized by a moderate south-easterly wind (15 m . s-1) and waves of up to 5 m of significant height at its apex. At the ADCP, strong currents of up to 0.8 m . s-1 near the surface and 0.5 m . s-1 near the bottom were recorded, parallel to the coast, flowing towards the south-west. The simulated currents were widely underestimated, even taking the effect of waves into account in the model. It was suspected that the representation of the wind in the atmospheric model was an underestimation. A new simulation was therefore run with an arbitrarily chosen stronger wind and its results were in much better agreement with the measurements. A simplified theoretical analysis successfully isolated the wind-induced processes, responsible for the strong currents measured during the apex and the strong vertical shear that occurred at the beginning of the storm. These processes were: 1/ the barotropic geostrophic current induced by a wind parallel to the coast and 2/ the Ekman spiral. The duration of the storm (about 36 h at the apex) explains the continuous increase of the current as predicted by the theory. The frictionally induced Ekman transport explains the current shear in the surface layer in the rising stage of the storm, and the addition of high waves and strong wind at the apex is more in favour of strong vertical mixing in the surface layer.
Gas tube-switched high voltage DC power converter
She, Xu; Bray, James William; Sommerer, Timothy John; Chokhawala, Rahul
2018-05-15
A direct current (DC)-DC converter includes a transformer and a gas tube-switched inverter circuit. The transformer includes a primary winding and a secondary winding. The gas tube-switched inverter circuit includes first and second inverter load terminals and first and second inverter input terminals. The first and second inverter load terminals are coupled to the primary winding. The first and second inverter input terminals are couplable to a DC node. The gas tube-switched inverter circuit further includes a plurality of gas tube switches respectively coupled between the first and second inverter load terminals and the first and second inverter input terminals. The plurality of gas tube switches is configured to operate to generate an alternating current (AC) voltage at the primary winding.
Korhonen, Petri; Kuk, Francis; Seper, Eric; Mørkebjerg, Martin; Roikjer, Majken
2017-01-01
Wind noise is a common problem reported by hearing aid wearers. The MarkeTrak VIII reported that 42% of hearing aid wearers are not satisfied with the performance of their hearing aids in situations where wind is present. The current study investigated the effect of a new wind noise attenuation (WNA) algorithm on subjective annoyance and speech recognition in the presence of wind. A single-blinded, repeated measures design was used. Fifteen experienced hearing aid wearers with bilaterally symmetrical (≤10 dB) mild-to-moderate sensorineural hearing loss participated in the study. Subjective rating for wind noise annoyance was measured for wind presented alone from 0° and 290° at wind speeds of 4, 5, 6, 7, and 10 m/sec. Phoneme identification performance was measured using Widex Office of Clinical Amplification Nonsense Syllable Test presented at 60, 65, 70, and 75 dB SPL from 270° in the presence of wind originating from 0° at a speed of 5 m/sec. The subjective annoyance from wind noise was reduced for wind originating from 0° at wind speeds from 4 to 7 m/sec. The largest improvement in phoneme identification with the WNA algorithm was 48.2% when speech was presented from 270° at 65 dB SPL and the wind originated from 0° azimuth at 5 m/sec. The WNA algorithm used in this study reduced subjective annoyance for wind speeds ranging from 4 to 7 m/sec. The algorithm was effective in improving speech identification in the presence of wind originating from 0° at 5 m/sec. These results suggest that the WNA algorithm used in the current study could expand the range of real-life situations where a hearing-impaired person can use the hearing aid optimally. American Academy of Audiology
An Examination of Secondary Wind Instrument Methods Courses
ERIC Educational Resources Information Center
Wagoner, Cynthia L.; Juchniewicz, Jay
2017-01-01
The purpose of this study was to investigate current secondary woodwind, brass, and combined wind instrument methods courses for preservice music teachers across the United States. Two-hundred eleven (N = 211) wind methods course instructors from National Association of Schools of Music-accredited institutions completed an online survey that…
About the Institute for Advanced Composites Manufacturing Innovation | Wind
goals for domestic manufacturing innovation. Image showing five technology areas in the center with a lead IACMI's wind turbine technology area. IACMI currently has five technology areas with centers in five states: Michigan: Vehicles Colorado: Wind turbines Ohio: Compressed gas storage Indiana: Design
Simulating Turbulent Wind Fields for Offshore Turbines in Hurricane-Prone Regions (Poster)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Guo, Y.; Damiani, R.; Musial, W.
Extreme wind load cases are one of the most important external conditions in the design of offshore wind turbines in hurricane prone regions. Furthermore, in these areas, the increase in load with storm return-period is higher than in extra-tropical regions. However, current standards have limited information on the appropriate models to simulate wind loads from hurricanes. This study investigates turbulent wind models for load analysis of offshore wind turbines subjected to hurricane conditions. Suggested extreme wind models in IEC 61400-3 and API/ABS (a widely-used standard in oil and gas industry) are investigated. The present study further examines the wind turbinemore » response subjected to Hurricane wind loads. Three-dimensional wind simulator, TurbSim, is modified to include the API wind model. Wind fields simulated using IEC and API wind models are used for an offshore wind turbine model established in FAST to calculate turbine loads and response.« less
Deployment of Wind Turbines in the Built Environment: Risks, Lessons, and Recommended Practices
DOE Office of Scientific and Technical Information (OSTI.GOV)
Baring-Gould, Ian; Fields, Jason; Oteri, Frank
Built-environment wind turbine (BEWT) projects are wind energy projects that are constructed on, in, or near buildings, as shown below. These projects present an opportunity for distributed, low-carbon generation combined with highly visible statements on sustainability, but the BEWT niche of the wind industry is still developing and is relatively less mature than the utility-scale wind or conventional ground-based distributed wind sectors. This poster investigates the current state of the BEWT industry by reviewing available literature on BEWT projects as well as interviewing project owners on their experiences deploying and operating the technology.
NREL Software Aids Offshore Wind Turbine Designs (Fact Sheet)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
2013-10-01
NREL researchers are supporting offshore wind power development with computer models that allow detailed analyses of both fixed and floating offshore wind turbines. While existing computer-aided engineering (CAE) models can simulate the conditions and stresses that a land-based wind turbine experiences over its lifetime, offshore turbines require the additional considerations of variations in water depth, soil type, and wind and wave severity, which also necessitate the use of a variety of support-structure types. NREL's core wind CAE tool, FAST, models the additional effects of incident waves, sea currents, and the foundation dynamics of the support structures.
Current Sheets in the Corona and the Complexity of Slow Wind
NASA Technical Reports Server (NTRS)
Antiochos, Spiro
2010-01-01
The origin of the slow solar wind has long been one of the most important problems in solar/heliospheric physics. Two observational constraints make this problem especially challenging. First, the slow wind has the composition of the closed-field corona, unlike the fast wind that originates on open field lines. Second, the slow wind has substantial angular extent, of order 30 degrees, which is much larger than the widths observed for streamer stalks or the widths expected theoretically for a dynamic heliospheric current sheet. We propose that the slow wind originates from an intricate network of narrow (possibly singular) open-field corridors that emanate from the polar coronal hole regions. Using topological arguments, we show that these corridors must be ubiquitous in the solar corona. The total solar eclipse in August 2008, near the lowest point of cycle 23 affords an ideal opportunity to test this theory by using the ultra-high resolution Predictive Science's (PSI) eclipse model for the corona and wind. Analysis of the PSI eclipse model demonstrates that the extent and scales of the open-field corridors can account for both the angular width of the slow wind and its closed-field composition. We discuss the implications of our slow wind theory for the structure of the corona and heliosphere at solar minimum and describe further observational and theoretical tests.
NASA Technical Reports Server (NTRS)
Allton, J. H.; Gonzalez, C. P.; Allums, K. K.
2017-01-01
Recent refinement of analysis of ACE/SWICS data (Advanced Composition Explorer/Solar Wind Ion Composition Spectrometer) and of onboard data for Genesis Discovery Mission of 3 regimes of solar wind at Earth-Sun L1 make it an appropriate time to update the availability and condition of Genesis samples specifically collected in these three regimes and currently curated at Johnson Space Center. ACE/SWICS spacecraft data indicate that solar wind flow types emanating from the interstream regions, from coronal holes and from coronal mass ejections are elementally and isotopically fractionated in different ways from the solar photosphere, and that correction of solar wind values to photosphere values is non-trivial. Returned Genesis solar wind samples captured very different kinds of information about these three regimes than spacecraft data. Samples were collected from 11/30/2001 to 4/1/2004 on the declining phase of solar cycle 23. Meshik, et al is an example of precision attainable. Earlier high precision laboratory analyses of noble gases collected in the interstream, coronal hole and coronal mass ejection regimes speak to degree of fractionation in solar wind formation and models that laboratory data support. The current availability and condition of samples captured on collector plates during interstream slow solar wind, coronal hole high speed solar wind and coronal mass ejections are de-scribed here for potential users of these samples.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nasir, M. N. M.; Saharuddin, N. Z.; Sulaima, M. F.
This paper presents the performance evaluation of standalone hybrid system on Photovoltaic (PV)-Wind generator at Faculty of Electrical Engineering (FKE), UTeM. The hybrid PV-Wind in UTeM system is combining wind turbine system with the solar system and the energy capacity of this hybrid system can generate up to charge the battery and supply the LED street lighting load. The purpose of this project is to evaluate the performance of PV-Wind hybrid generator. Solar radiation meter has been used to measure the solar radiation and anemometer has been used to measure the wind speed. The effectiveness of the PV-Wind system ismore » based on the various data that has been collected and compared between them. The result shows that hybrid system has greater reliability. Based on the solar result, the correlation coefficient shows strong relationship between the two variables of radiation and current. The reading output current followed by fluctuate of solar radiation. However, the correlation coefficient is shows moderate relationship between the two variables of wind speed and voltage. Hence, the wind turbine system in FKE show does not operate consistently to produce energy source for this hybrid system compare to PV system. When the wind system does not fully operate due to inconsistent energy source, the other system which is PV will operate and supply the load for equilibrate the extra load demand.« less
NASA Astrophysics Data System (ADS)
Viall, N. M.; Kepko, L.; Antiochos, S. K.; Lepri, S. T.; Vourlidas, A.; Linker, J.
2017-12-01
Connecting the structure and variability in the solar corona to the Heliosphere and solar wind is one of the main goals of Heliophysics and space weather research. The instrumentation and viewpoints of the Parker Solar Probe and Solar Orbiter missions will provide an unprecedented opportunity to combine remote sensing with in situ data to determine how the corona drives the Heliosphere, especially as it relates to the origin of the slow solar wind. We present analysis of STEREO coronagraph and heliospheric imager observations and of in situ ACE and Wind measurements that reveal an important connection between the dynamics of the corona and of the solar wind. We show observations of quasi-periodic release of plasma into the slow solar wind occurring throughout the corona - including regions away from the helmet streamer and heliospheric current sheet - and demonstrate that these observations place severe constraints on the origin of the slow solar wind. We build a comprehensive picture of the dynamic evolution by combining remote imaging data, in situ composition and magnetic connectivity information, and MHD models of the solar wind. Our results have critical implications for the magnetic topology involved in slow solar wind formation and magnetic reconnection dynamics. Crucially, this analysis pushes the limits of current instrument resolution and sensitivity, showing the enormous potential science to be accomplished with the Parker Solar Probe and Solar Orbiter missions.
GIS-based approach for the evaluation of offshore wind power potential for Gujarat
NASA Astrophysics Data System (ADS)
Patel, Dhrumin; Nagababu, Garlapati; Radadia, Nishil; Parsana, Sohil; Sheth, Mohak; Sheth, Nisarg
2018-05-01
In the current global scenario, India is increasing its focus towards the methods to enrich the benefits of non-renewable energy sources as much as possible due to their key advantage of having low carbon footprint. India has already emerged as a key global player in on-shore wind energy and to achieve its annual wind energy production demand of 50 GWh, avenues other than current options have been researched on. Offshore wind energy has experienced remarkable growth worldwide but has not yet been harnessed sufficiently in India, despite addressing many of environmental and economic concerns. The present study focuses on offshore wind resource assessment on Indian exclusive economic zone (EEZ) around Gujarat region. The geographical information system (GIS) methodology has been used to develop maps of wind speed, power density and capacity factor maps. Further, careful consideration has been accorded for expulsion of marine protected areas, shipping transportation lines, fishing zones, and migratory bird movements. The resultant available area has been considered for annual energy production considering data from Siemens Wind Turbine 3.6. The results obtained shows that offshore wind energy can offset twice the annual energy demand of entire country with a potential energy production of more than 2580 TWh.
Field Tests of Wind Turbine Unit with Tandem Wind Rotors and Double Rotational Armatures
NASA Astrophysics Data System (ADS)
Galal, Ahmed Mohamed; Kanemoto, Toshiaki
This paper discusses the field tests of the wind turbine unit, in which the front and the rear wind rotors drive the inner and the outer armatures of the synchronous generator. The wind rotors were designed conveniently by the traditional procedure for the single wind rotor, where the diameters of the front and the rear wind rotors are 2 m and 1.33 m. The tests were done on a pick-up type truck driven straightly at constant speed. The rotational torque of the unit is directly proportional to the induced electric current irrespective of the rotational speeds of the wind rotors, while the induced voltage is proportional to the relative rotational speed. The performance of the unit is significantly affected not only by the wind velocity, but also by the blade setting angles of both wind rotors and the applied load especially at lower wind velocity.
Jha, Kamal N.
1999-01-01
An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard.
Mullany, Lila E.; Herrick, Jennifer S.; Wolff, Roger K.; Stevens, John R.; Slattery, Martha L.
2016-01-01
Smoking is known to influence messenger RNA (mRNA) expression in colorectal cancer (CRC) cases. As microRNAs (miRNAs) are known repressors of mRNAs, we hypothesize that smoking may influence miRNA expression, thus altering mRNA expression. Our sample consisted of 1447 CRC cases that had normal colorectal mucosa and carcinoma miRNA data and lifestyle data. We examined current smoking, current versus never and former versus never (C/F/N) smoking1, and pack-years smoked with miRNA expression in normal mucosa as well as differential miRNA expression between paired normal and carcinoma tissue for colon and rectal tissue to determine associations between smoking and miRNA expression. We adjusted for multiple comparisons using the Benjamini Hochberg false discovery rate (FDR). Significant associations were seen for rectal differential miRNA expression only. We analyzed miRNAs significantly associated with smoking with CIMP and MSI status, using a polytomous logistic regression. Two hundred and thirty-one miRNAs were differentially expressed with current smoking, 172 with C/F/N, and 206 with pack-years smoked; 111 were associated with all three. Forty-three miRNAs were unique to current smoking, 14 were unique to C/F/N and 57 were unique to pack years smoked. Of the 306 unique miRNAs associated with cigarette smoking, 41 were inversely associated and 200 were directly associated with CIMP high or MSI tumor molecular phenotype for either colon or rectal cancer. Our results suggest that cigarette smoking can alter miRNA expression and, given associations with CIMP high and MSI tumor molecular phenotype, it is possible that smoking influences tumor phenotype through altered miRNA expression. PMID:27780077
A review of climate change impacts on birds
Robert W. Butler; William Taylor
2005-01-01
Regions of the world with high coastal zone biological productivity often support large numbers of birds. Important sources of this productivity are oceanographic upwelling created by winds and ocean currents, and runoff from the land. It is suggested that climate change effects on winds and ocean currents will potentially affect the timing and magnitude of coastal...
NASA Technical Reports Server (NTRS)
Consiglio, Maria C.; Hoadley, Sherwood T.; Allen, B. Danette
2009-01-01
Wind prediction errors are known to affect the performance of automated air traffic management tools that rely on aircraft trajectory predictions. In particular, automated separation assurance tools, planned as part of the NextGen concept of operations, must be designed to account and compensate for the impact of wind prediction errors and other system uncertainties. In this paper we describe a high fidelity batch simulation study designed to estimate the separation distance required to compensate for the effects of wind-prediction errors throughout increasing traffic density on an airborne separation assistance system. These experimental runs are part of the Safety Performance of Airborne Separation experiment suite that examines the safety implications of prediction errors and system uncertainties on airborne separation assurance systems. In this experiment, wind-prediction errors were varied between zero and forty knots while traffic density was increased several times current traffic levels. In order to accurately measure the full unmitigated impact of wind-prediction errors, no uncertainty buffers were added to the separation minima. The goal of the study was to measure the impact of wind-prediction errors in order to estimate the additional separation buffers necessary to preserve separation and to provide a baseline for future analyses. Buffer estimations from this study will be used and verified in upcoming safety evaluation experiments under similar simulation conditions. Results suggest that the strategic airborne separation functions exercised in this experiment can sustain wind prediction errors up to 40kts at current day air traffic density with no additional separation distance buffer and at eight times the current day with no more than a 60% increase in separation distance buffer.
Dispersal of Sediment in the Western Adriatic during Energetic Wintertime Forcing
NASA Astrophysics Data System (ADS)
Harris, C. K.; Sherwood, C. R.; Mullenbach, B. L.; Pullen, J. D.
2003-12-01
EuroSTRATAFORM aims to relate sediment delivery and reworking to seabed morphology and stratigraphy through observations and modeling of water column transport. The Po River dominates buoyancy and sediment input into the Adriatic Sea, but small Apeninne rivers (the Chienti, Pescara, etc.) may produce locally important signals. Sedimentation is influenced by fluvial supply, resuspension by waves and currents, and transport by oceanographic currents forced by winds and buoyancy. Transport is likely highest during times of energetic forcing; including Bora events with northeasterly winds and Sirocco events with southeasterly winds. It is difficult, from field measurements alone, to characterize dispersal and convergence patterns over the relevant spatial scales. We applied a three-dimensional hydrodynamic model that includes fluvial delivery, transport, resuspension, and deposition of sediment to quantify sediment dispersal with a 2-km resolution over the entire Adriatic. Circulation calculations were driven by spatially- and temporally-varying wind fields for the Fall / Winter of 2002 / 2003 and realistic Po and Apennine river discharges. Waves were hindcast with the SWAN model. Dispersion of both resuspended and river-derived sediment was estimated for periods that contained intense Bora and Sirocco winds. Predicted sediment dispersal rates and patterns are sensitive to forcing winds, buoyancy flux, and wave patterns. Higher sediment flux was predicted during Bora conditions than during Sirocco conditions. Sirocco winds weaken the Western Adriatic Coastal Current (WACC), and because they tend to concentrate over the Eastern Adriatic, they often fail to create especially energetic waves in the Western Adriatic. Bora wind conditions, on the other hand, intensify the WACC and can build high wave energies over the northwestern Adriatic. Most of the sediment transport occurs during Bora, with a net southward flux. These predictions will be compared to field observations made as part of the EuroSTRATAFORM experiment.
Impact analysis of air gap motion with respect to parameters of mooring system for floating platform
NASA Astrophysics Data System (ADS)
Shen, Zhong-xiang; Huo, Fa-li; Nie, Yan; Liu, Yin-dong
2017-04-01
In this paper, the impact analysis of air gap concerning the parameters of mooring system for the semi-submersible platform is conducted. It is challenging to simulate the wave, current and wind loads of a platform based on a model test simultaneously. Furthermore, the dynamic equivalence between the truncated and full-depth mooring system is still a tuff work. However, the wind and current loads can be tested accurately in wind tunnel model. Furthermore, the wave can be simulated accurately in wave tank test. The full-scale mooring system and the all environment loads can be simulated accurately by using the numerical model based on the model tests simultaneously. In this paper, the air gap response of a floating platform is calculated based on the results of tunnel test and wave tank. Meanwhile, full-scale mooring system, the wind, wave and current load can be considered simultaneously. In addition, a numerical model of the platform is tuned and validated by ANSYS AQWA according to the model test results. With the support of the tuned numerical model, seventeen simulation cases about the presented platform are considered to study the wave, wind, and current loads simultaneously. Then, the impact analysis studies of air gap motion regarding the length, elasticity, and type of the mooring line are performed in the time domain under the beam wave, head wave, and oblique wave conditions.
NASA Astrophysics Data System (ADS)
Liu, Hongbo; Liu, Haihan; Liu, Sitong; Peng, Huanhuan
2018-06-01
The VSC-HVDC connection system will be the effective transmission method for the large scale and long distance integrated wind farm. Because of the fluctuating power, the DC voltage will be over-voltage or under-voltage in transmission line which will affect the steady operation of the wind power integrating system. In order to mitigate the DC voltage variation of the grid-connected inverter on the grid side and improve the dynamic response of the system, a load current feed-forward control scheme is put forward. Firstly, this paper analyses stability of a system without additional feed-forward control based on double close loop. Secondly, the load current which can indicate the power changes is introduced to counteract the fluctuation of DC voltage in the improvement control scheme. By simulating the results show that the proposed control strategy can improve the dynamic response performance and mitigate the fluctuation of the active power output of the wind farm.
Green, A C; Hughes, M C B; McBride, P; Fourtanier, A
2011-02-01
Precise factors associated with premature skin aging, or photoaging, in the general population are unknown. To examine the risk factors for photoaging in a Queensland community. A cross-sectional study of 1,400 randomly selected residents aged 20-54 years, using casts of the back of the hand (surface microtopography) and dermatological assessment of photoaging. 83% of the participants had premature skin aging, worsening after the age of 30. Severe neck wrinkling was 3 times more likely in men and some 4 times more likely in fair-skinned people (odds ratio, OR=3.86, 95% confidence interval, CI=2.40-6.23). Red hair and mainly outdoor work or leisure raised the odds of microtopographic photoaging. Current smoking was strongly associated with facial comedones and telangiectasia, and among current smokers, the microtopography grade was significantly associated with moderate and heavy smoking measured by pack-years of exposure, with OR=3.18 (95% CI=1.38-7.35) in the heaviest (>20 pack-years) smoking category compared with 1-7 pack-years. Premature skin aging is common in the subtropics, more severe in men and the fair-skinned. It is associated with high sun exposure during leisure or work, and moderate to heavy smoking, and therefore is preventable. Copyright © 2010 S. Karger AG, Basel.
Wind-induced circulation in a large tropical lagoon: Chetumal Bay
NASA Astrophysics Data System (ADS)
Palacios, E.; Carrillo, L.
2013-05-01
Chetumal Bay is a large tropical lagoon located at the Mesoamerican Reef System. Windinduced circulation in this basin was investigated by using direct measurements of current, sea level, and 2d barotropic numerical model. Acoustic Doppler Profiler (ADP) transects covering the north of Chetumal Bay during two campaigns September 2006 and March 2007 were used. The 2d barotropic numerical model was ROMs based and wind forced. Wind information was obtained from a meteorological station located at ECOSUR Chetumal. Sea level data was collected from a pressure sensor deployed in the lagoon. A seasonal pattern of circulation was observed. From observations, during September 2006, a northward flow was shown in most part of the bay and a southward flow in the eastern coast was observed with velocities ranged from 6 cm s-1 to 36 cm s-1. In March 2007, the current pattern was more complex; divergences and converges were identified. The dominant circulation was northward in eastern portion, and southward in the central and western zone. The average current speed was 6 cm s-1 with maximum values of 26 -34 cm s-1. During September 2006 predominant wind was easternsoutheastern and during March 2007, northerly wind events were recorded. Sea level amplitude responded quickly to changes in the magnitude and direction of the wind. Results of sea level and circulation from the 2d barotropic numerical model agreed with observations at first approximation.
The formation of a cold-core eddy in the East Australian Current
NASA Astrophysics Data System (ADS)
Macdonald, H. S.; Roughan, M.; Baird, M. E.; Wilkin, J.
2016-02-01
Cold-core eddies (CCEs) frequently form in western boundary currents and can affect continental shelf processes. It is not always clear, however, if baroclinic or barotropic instabilities contribute more to their formation. The Regional Ocean Modelling System (ROMS) is used to investigate the ocean state during the formation of a CCE in the East Australian Current (EAC) during October 2009. The observed eddy initially appeared as a small billow (approx. 50 km in length) that perturbed the landward edge of the EAC. The billow grew into a mesoscale CCE (approx. 100 km in diameter), diverting the EAC around it. A ROMS simulation with a realistic wind field reproduced a similar eddy. This eddy formed from negative vorticity waters found on the continental shelf south of the EAC separation point. A sensitivity analysis is performed whereby the impact of 3 different wind forcing scenarios, upwelling, downwelling, and no winds, are investigated. A CCE formed in all wind scenarios despite the wind induced changes in hydrographic conditions in the continental shelf and slope waters. As such, the source of energy for eddy formation did not come from the interactions of wind with the continental shelf waters. Analysis of strain and energy transformation confirms this by showing that the prevailing source of CCE energy was kinetic energy of the offshore EAC. These results clearly link the formation of the CCE to the swift flowing EAC and barotropic instabilities.
Calculation of wind-driven surface currents in the North Atlantic Ocean
NASA Technical Reports Server (NTRS)
Rees, T. H.; Turner, R. E.
1976-01-01
Calculations to simulate the wind driven near surface currents of the North Atlantic Ocean are described. The primitive equations were integrated on a finite difference grid with a horizontal resolution of 2.5 deg in longitude and latitude. The model ocean was homogeneous with a uniform depth of 100 m and with five levels in the vertical direction. A form of the rigid-lid approximation was applied. Generally, the computed surface current patterns agreed with observed currents. The development of a subsurface equatorial countercurrent was observed.
Simulation of the Impact of New Ocean Surface Wind Measurements on H*Wind Analyses
NASA Technical Reports Server (NTRS)
Miller, Timothy; Atlas, Robert; Black, Peter; Chen, Shuyi; Hood, Robbie; Johnson, James; Jones, Linwood; Ruf, Chris; Uhlhorn, Eric
2008-01-01
The H*Wind analysis, a product of the Hurricane Research Division of NOAA's Atlantic Oceanographic and Meteorological Laboratory, brings together wind measurements from a variety of observation platforms into an objective analysis of the distribution of surface wind speeds in a tropical cyclone. This product is designed to improve understanding of the extent and strength of the wind field, and to improve the assessment of hurricane intensity. See http://www.aoml.noaa.gov/hrd/data sub/wind.html. The Hurricane Imaging Radiometer (HIRAD) is a new passive microwave remote sensor for hurricane observations that is currently under development by NASA Marshall Space Flight Center, NOAA Hurricane Research Division, the University of Central Florida and the University of Michigan. HIRAD is being designed to enhance the current real-time airborne ocean surface winds observation capabilities of NOAA and USAF Weather Squadron hurricane hunter aircraft using the operational airbome Stepped Frequency Microwave Radiometer (SFMR). Unlike SFMR, which measures wind speed and rain rate along the ground track directly beneath the aircraft, HIRAD will provide images of the surface wind and rain field over a wide swath (approximately 3 x the aircraft altitude, or approximately 2 km from space). The instrument is described in a separate paper presented at this conference. The present paper describes a set of Observing System Simulation Experiments (OSSEs) in which measurements from the new instrument as well as those from existing instruments (air, surface, and space-based) are simulated from the output of a numerical model from the University of Miami, and those results are used to construct H*Wind analyses. Evaluations will be presented on the relative impact of HIRAD and other instruments on H*Wind analyses, including the use of HIRAD from 2 aircraft altitudes and from a space-based platform.
Wang, Jiyu; Ding, Wenbo; Pan, Lun; Wu, Changsheng; Yu, Hua; Yang, Lijun; Liao, Ruijin; Wang, Zhong Lin
2018-04-24
The development of the Internet of Things has brought new challenges to the corresponding distributed sensor systems. Self-powered sensors that can perceive and respond to environmental stimuli without an external power supply are highly desirable. In this paper, a self-powered wind sensor system based on an anemometer triboelectric nanogenerator (a-TENG, free-standing mode) and a wind vane triboelectric nanogenerator (v-TENG, single-electrode mode) is proposed for simultaneously detecting wind speed and direction. A soft friction mode is adopted instead of a typical rigid friction for largely enhancing the output performance of the TENG. The design parameters including size, unit central angle, and applied materials are optimized to enhance sensitivity, resolution, and wide measurement scale. The optimized a-TENG could deliver an open-circuit voltage of 88 V and short-circuit current of 6.3 μA, corresponding to a maximum power output of 0.47 mW (wind speed of 6.0 m/s), which is capable of driving electronics for data transmission and storage. The current peak value of the a-TENG signal is used for analyzing wind speed for less energy consumption. Moreover, the output characteristics of a v-TENG are further explored, with six actual operation situations, and the v-TENG delivers fast response to the incoming wind and accurately outputs the wind direction data. As a wind sensor system, wind speed ranging from 2.7 to 8.0 m/s can be well detected (consistent with a commercial sensor) and eight regular directions can be monitored. Therefore, the fabricated wind sensor system has great potential in wireless environmental monitoring applications.
Gusts and Shear in an Idealized LES-modeled Hurricane
NASA Astrophysics Data System (ADS)
Worsnop, R.; Lundquist, J. K.; Bryan, G. H.; Damiani, R.; Musial, W.
2016-12-01
Tropical cyclone winds can cause extreme loading and damage to coastal structures such as buildings and energy infrastructure. Offshore wind energy development is underway along the US East Coast where hurricanes pose a substantial risk. Understanding wind gusts, gust factor, shear, and veer in the hurricane boundary layer (HBL) can help manufacturers assess risk and design wind turbines to better withstand these extreme wind conditions. Because of the paucity of observational data at low-levels (200 m and below), we use the Cloud Model Version I (CM1) large-eddy simulation numerical model to simulate high spatial- (10 m) and temporal- (0.1 s) resolution data. This unique dataset is used to answer the following questions: do severe mean wind speeds and gusts that exceed current design limits occur?; how does the gust factor vary with distance from the eye?; and lastly, how does wind direction vary horizontally and with height? We find that mean winds and gusts near the eyewall can exceed current turbine design thresholds of 50 m s-1 and 70 m s-1, respectively. Gust factors are greatest at the eye-eyewall interface just inward of the peak gust location and can exceed the 1.4 value used to convert a 50 m s-1 reference wind speed to a 50-year 3-second gust. Strong veer (15-30 degrees) across a 120 m-layer suggests that veer should be assessed against standard design prescriptions. Lastly, wind directions can shift 10-25 degrees in durations shorter than 10 minutes, which can challenge structures designed to endure winds from a consistent direction for periods longer than 10 minutes, including wind turbines.
Introduction to Voigt's wind power plant. [energy conversion efficiency
NASA Technical Reports Server (NTRS)
Tompkin, J.
1973-01-01
The design and operation of a 100 kilowatt wind driven generator are reported. Its high speed three-bladed turbine operates at a height of 50 meters. Blades are rigidly connected to the hub and turbine revolutions change linearly with wind velocity, maintaining a constant speed ratio of blade tip velocity to wind velocity over the full predetermined wind range. Three generators installed in the gondola generate either dc or ac current. Based on local wind conditions, the device has a maximum output of 720 kilowatts at a wind velocity of 16 meters per second. Total electrical capacity is 750 kilowatts, and power output per year is 2,135,000 kilowatt/hours.
Wind loading on solar concentrators: Some general considerations
NASA Technical Reports Server (NTRS)
Roschke, E. J.
1984-01-01
A survey was completed to examine the problems and complications arising from wind loading on solar concentrators. Wind loading is site specific and has an important bearing on the design, cost, performance, operation and maintenance, safety, survival, and replacement of solar collecting systems. Emphasis herein is on paraboloidal, two-axis tracking systems. Thermal receiver problems also are discussed. Wind characteristics are discussed from a general point of view. Current methods for determining design wind speed are reviewed. Aerodynamic coefficients are defined and illustrative examples are presented. Wind tunnel testing is discussed, and environmental wind tunnels are reviewed. Recent results on heliostat arrays are reviewed as well. Aeroelasticity in relation to structural design is discussed briefly.
Monitoring Tidal Currents with a Towed ADCP System
2015-12-22
these make tidal stream energy a more reliable source than other forms of ma- rine energy, such as waves and offshore wind. The place of tidal stream...big tidal range (9 m), relatively strong (2 m/s) currents, and moderate wind waves (less than 3 m in the an- nual mean), it is considered to be a...Monitoring tidal currents with a towed ADCP system Alexei Sentchev1 & Max Yaremchuk2 Received: 22 September 2015 /Accepted: 10 December 2015
NASA Astrophysics Data System (ADS)
Stroeve, Julienne C.; Jenouvrier, Stephanie; Campbell, G. Garrett; Barbraud, Christophe; Delord, Karine
2016-08-01
Sea ice variability within the marginal ice zone (MIZ) and polynyas plays an important role for phytoplankton productivity and krill abundance. Therefore, mapping their spatial extent as well as seasonal and interannual variability is essential for understanding how current and future changes in these biologically active regions may impact the Antarctic marine ecosystem. Knowledge of the distribution of MIZ, consolidated pack ice and coastal polynyas in the total Antarctic sea ice cover may also help to shed light on the factors contributing towards recent expansion of the Antarctic ice cover in some regions and contraction in others. The long-term passive microwave satellite data record provides the longest and most consistent record for assessing the proportion of the sea ice cover that is covered by each of these ice categories. However, estimates of the amount of MIZ, consolidated pack ice and polynyas depend strongly on which sea ice algorithm is used. This study uses two popular passive microwave sea ice algorithms, the NASA Team and Bootstrap, and applies the same thresholds to the sea ice concentrations to evaluate the distribution and variability in the MIZ, the consolidated pack ice and coastal polynyas. Results reveal that the seasonal cycle in the MIZ and pack ice is generally similar between both algorithms, yet the NASA Team algorithm has on average twice the MIZ and half the consolidated pack ice area as the Bootstrap algorithm. Trends also differ, with the Bootstrap algorithm suggesting statistically significant trends towards increased pack ice area and no statistically significant trends in the MIZ. The NASA Team algorithm on the other hand indicates statistically significant positive trends in the MIZ during spring. Potential coastal polynya area and amount of broken ice within the consolidated ice pack are also larger in the NASA Team algorithm. The timing of maximum polynya area may differ by as much as 5 months between algorithms. These differences lead to different relationships between sea ice characteristics and biological processes, as illustrated here with the breeding success of an Antarctic seabird.
Dynamics of Intense Currents in the Solar Wind
NASA Astrophysics Data System (ADS)
Artemyev, Anton V.; Angelopoulos, Vassilis; Halekas, Jasper S.; Vinogradov, Alexander A.; Vasko, Ivan Y.; Zelenyi, Lev M.
2018-06-01
Transient currents in the solar wind are carried by various magnetic field discontinuities that contribute significantly to the magnetic field fluctuation spectrum. Internal instabilities and dynamics of these discontinuities are believed to be responsible for magnetic field energy dissipation and corresponding charged particle acceleration and heating. Accurate modeling of these phenomena requires detailed investigation of transient current formation and evolution. By examining such evolution using a unique data set compiled from observations of the same solar wind flow by two spacecraft at Earth’s and Mars’s orbits, we show that it consists of several processes: discontinuity thinning (decrease in thickness normalized by the ion inertial length), intensification of currents normalized to the proton thermal current (i.e., the product of proton charge, density, and thermal velocity), and increase in the compressional component of magnetic field variations across discontinuities. The significant proton temperature variation around most observed discontinuities indicates possible proton heating. Plasma velocity jumps across the discontinuities are well correlated with Alfvén velocity changes. We discuss possible explanations of the observed discontinuity evolution. We also compare the observed evolution with predictions of models describing discontinuity formation due to Alfvén wave steepening. Our results show that discontinuity modeling likely requires taking into account both the effects of nonlinear Alfvén wave dynamics and solar wind expansion.
Stead, Martine; Moodie, Crawford; Angus, Kathryn; Bauld, Linda; McNeill, Ann; Thomas, James; Hastings, Gerard; Hinds, Kate; O'Mara-Eves, Alison; Kwan, Irene; Purves, Richard I; Bryce, Stuart L
2013-01-01
Standardised or 'plain' tobacco packaging was introduced in Australia in December 2012 and is currently being considered in other countries. The primary objective of this systematic review was to locate, assess and synthesise published and grey literature relating to the potential impacts of standardised tobacco packaging as proposed by the guidelines for the international Framework Convention on Tobacco Control: reduced appeal, increased salience and effectiveness of health warnings, and more accurate perceptions of product strength and harm. Electronic databases were searched and researchers in the field were contacted to identify studies. Eligible studies were published or unpublished primary research of any design, issued since 1980 and concerning tobacco packaging. Twenty-five quantitative studies reported relevant outcomes and met the inclusion criteria. A narrative synthesis was conducted. Studies that explored the impact of package design on appeal consistently found that standardised packaging reduced the appeal of cigarettes and smoking, and was associated with perceived lower quality, poorer taste and less desirable smoker identities. Although findings were mixed, standardised packs tended to increase the salience and effectiveness of health warnings in terms of recall, attention, believability and seriousness, with effects being mediated by the warning size, type and position on pack. Pack colour was found to influence perceptions of product harm and strength, with darker coloured standardised packs generally perceived as containing stronger tasting and more harmful cigarettes than fully branded packs; lighter coloured standardised packs suggested weaker and less harmful cigarettes. Findings were largely consistent, irrespective of location and sample. The evidence strongly suggests that standardised packaging will reduce the appeal of packaging and of smoking in general; that it will go some way to reduce consumer misperceptions regarding product harm based upon package design; and will help make the legally required on-pack health warnings more salient.
Stead, Martine; Moodie, Crawford; Angus, Kathryn; Bauld, Linda; McNeill, Ann; Thomas, James; Hastings, Gerard; Hinds, Kate; O'Mara-Eves, Alison; Kwan, Irene; Purves, Richard I.; Bryce, Stuart L.
2013-01-01
Background and Objectives Standardised or ‘plain’ tobacco packaging was introduced in Australia in December 2012 and is currently being considered in other countries. The primary objective of this systematic review was to locate, assess and synthesise published and grey literature relating to the potential impacts of standardised tobacco packaging as proposed by the guidelines for the international Framework Convention on Tobacco Control: reduced appeal, increased salience and effectiveness of health warnings, and more accurate perceptions of product strength and harm. Methods Electronic databases were searched and researchers in the field were contacted to identify studies. Eligible studies were published or unpublished primary research of any design, issued since 1980 and concerning tobacco packaging. Twenty-five quantitative studies reported relevant outcomes and met the inclusion criteria. A narrative synthesis was conducted. Results Studies that explored the impact of package design on appeal consistently found that standardised packaging reduced the appeal of cigarettes and smoking, and was associated with perceived lower quality, poorer taste and less desirable smoker identities. Although findings were mixed, standardised packs tended to increase the salience and effectiveness of health warnings in terms of recall, attention, believability and seriousness, with effects being mediated by the warning size, type and position on pack. Pack colour was found to influence perceptions of product harm and strength, with darker coloured standardised packs generally perceived as containing stronger tasting and more harmful cigarettes than fully branded packs; lighter coloured standardised packs suggested weaker and less harmful cigarettes. Findings were largely consistent, irrespective of location and sample. Conclusions The evidence strongly suggests that standardised packaging will reduce the appeal of packaging and of smoking in general; that it will go some way to reduce consumer misperceptions regarding product harm based upon package design; and will help make the legally required on-pack health warnings more salient. PMID:24146791
Perceived Uncertainty Sources in Wind Power Plant Design
DOE Office of Scientific and Technical Information (OSTI.GOV)
Damiani, Rick R
This presentation for the Fourth Wind Energy Systems Engineering Workshop covers some of the uncertainties that still impact turbulent wind operation and how these affect design and structural reliability; identifies key sources and prioritization for R and D; and summarizes an analysis of current procedures, industry best practice, standards, and expert opinions.
USDA-ARS?s Scientific Manuscript database
Comprehensive control of odors, hydrogen sulfide (H2S), ammonia (NH3) and odorous volatile organic compound (VOC) emissions associated with animal production is a critical need. Current methods utilizing wind tunnels and flux chambers for measurements of gaseous emissions from area sources such as f...
NASA Technical Reports Server (NTRS)
Dussling, Joseph John
2015-01-01
A brief history of the 8x6 Supersonic Wind Tunnel (SWT) and 9x15 Low Speed Wind Tunnel (LSWT) at NASA Glenn Research Center, Cleveland, Ohio is presented along with current capabilities and plans for future upgrades within the facility.