WorldWideScience

Sample records for wind pattern derived

  1. Long-Term Wind Patterns Derived from Regional Mapping of Sand Dune Fields on Mars

    Science.gov (United States)

    Zimbelman, J. R.; Ku, Y.

    2016-12-01

    Aeolian bedforms such as sand dunes and wind ripples can be used to derive information about the winds that formed these features. Such information is particularly important for Mars, where there is only very limited measurements obtained from sensors on a few landers and rovers. We have used images (6 m/pixel) obtained by the Context Camera (CTX) on the Mars Reconnaissance Orbiter spacecraft to document the types and orientations of sand dunes at forty sites spread around Mars, at locations where other on-going investigations have measured ripple orientations on sand dunes using High Resolution Imaging Science Experiment (HiRISE) images. The study sites come from a wide range of physiographic and topographic settings over within a broad range of latitude and longitude around the planet. Multiple dune types are observed at most sites, suggesting variable or changing wind patterns may have been present over the lifetime of each dune field. Dune types were identified at the 40 dune fields, covering a total of 11,477 km2; barchanoid ridge (30.4%), transverse (27.2%), barchan (13.5%), linear (1.0%), star (sand patch (17.2%), sand sheet (10.2%), and unknown (0.4%). The dune types indicate diverse `long term' wind patterns that produced the distinctive dune shapes observed at each site, which may or may not correlate to the orientation of ripples observed on individual dunes as seen in HiRISE images. These results support the importance of recognizing both short term (`recent') sand-driving formative aeolian processes and long term (time scale unknown) winds that have generated and modified the shape of the sand dunes, consistent with the inferences made from a complementary study of ripples and dunes on Mars as reported by Liu et al. at this conference.

  2. Derivative Sign Patterns

    Science.gov (United States)

    Clark, Jeffrey

    2011-01-01

    Analysis of the patterns of signs of infinitely differentiable real functions shows that only four patterns are possible if the function is required to exhibit the pattern at all points in its domain and that domain is the set of all real numbers. On the other hand all patterns are possible if the domain is a bounded open interval.

  3. Wind regimes derived from martian large ripples: Implications for long-term and short-term wind dynamics

    Science.gov (United States)

    Liu, Z. Y. C.; Zimbelman, J. R.; Fenton, L. K.

    2016-12-01

    Aeolian bedforms, such as sand dunes and wind ripples, have been extensively used to derive surface wind regimes on Mars. However, the distinction of different temporal (i.e., long-term vs. short-term) and spatial (i.e., global vs. local) scales of surface winds derived from these bedforms is unclear. In addition, many recent studies have utilized various scales of numeric modeling, such as global scale general circulation models, mesoscale, and microscale airflow models, to analyze surface wind regimes based on aeolian features and compare the modeled winds with those derived from mapping of dunes and ripples. These results showed some degree of discrepancy between mapping-inferred winds and modeled winds, which may be in part due to the lack of recognition of different scales of winds. Since the knowledge of possible wind patterns is essential to understanding past and present climate on Mars, this study aims to classify the types of surface wind derived from different aeolian features. Here we use large martian ripples as indicators to infer near-surface wind regimes, following an approach previously developed by us. We then compare the ripple-inferred winds with those derived from both dune slipfaces and crestline alignments, using IMGBNT (inverse maximum gross bedform-normal transport) and IMSF (inverse mean sand flux) techniques. Our initial results show that ripple-inferred wind regimes are consistent with either dune crestline orientations or slipface-inferred wind regimes. The former implies the interaction between airflow and dune crest topography (i.e., form-flow), which produces the longitudinal winds, whereas the slipface-inferred winds are most likely transverse in nature. Furthermore, our results suggest that dune slipface and large ripples may better reflect local-scale, short-period wind dynamics, whereas dune alignment may better reflects large-scale, long-period wind dynamics. Thus, comparison of wind regimes using numeric modeling should be

  4. A nonlinear dynamics approach for incorporating wind-speed patterns into wind-power project evaluation.

    Science.gov (United States)

    Huffaker, Ray; Bittelli, Marco

    2015-01-01

    Wind-energy production may be expanded beyond regions with high-average wind speeds (such as the Midwest U.S.A.) to sites with lower-average speeds (such as the Southeast U.S.A.) by locating favorable regional matches between natural wind-speed and energy-demand patterns. A critical component of wind-power evaluation is to incorporate wind-speed dynamics reflecting documented diurnal and seasonal behavioral patterns. Conventional probabilistic approaches remove patterns from wind-speed data. These patterns must be restored synthetically before they can be matched with energy-demand patterns. How to accurately restore wind-speed patterns is a vexing problem spurring an expanding line of papers. We propose a paradigm shift in wind power evaluation that employs signal-detection and nonlinear-dynamics techniques to empirically diagnose whether synthetic pattern restoration can be avoided altogether. If the complex behavior of observed wind-speed records is due to nonlinear, low-dimensional, and deterministic system dynamics, then nonlinear dynamics techniques can reconstruct wind-speed dynamics from observed wind-speed data without recourse to conventional probabilistic approaches. In the first study of its kind, we test a nonlinear dynamics approach in an application to Sugarland Wind-the first utility-scale wind project proposed in Florida, USA. We find empirical evidence of a low-dimensional and nonlinear wind-speed attractor characterized by strong temporal patterns that match up well with regular daily and seasonal electricity demand patterns.

  5. Derivative Sign Patterns in Two Dimensions

    Science.gov (United States)

    Schilling, Kenneth

    2013-01-01

    Given a function defined on a subset of the plane whose partial derivatives never change sign, the signs of the partial derivatives form a two-dimensional pattern. We explore what patterns are possible for various planar domains.

  6. Wind gust models derived from field data

    Science.gov (United States)

    Gawronski, W.

    1995-01-01

    Wind data measured during a field experiment were used to verify the analytical model of wind gusts. Good coincidence was observed; the only discrepancy occurred for the azimuth error in the front and back winds, where the simulated errors were smaller than the measured ones. This happened because of the assumption of the spatial coherence of the wind gust model, which generated a symmetric antenna load and, in consequence, a low azimuth servo error. This result indicates a need for upgrading the wind gust model to a spatially incoherent one that will reflect the real gusts in a more accurate manner. In order to design a controller with wind disturbance rejection properties, the wind disturbance should be known at the input to the antenna rate loop model. The second task, therefore, consists of developing a digital filter that simulates the wind gusts at the antenna rate input. This filter matches the spectrum of the measured servo errors. In this scenario, the wind gusts are generated by introducing white noise to the filter input.

  7. Cluster Analysis of the Wind Events and Seasonal Wind Circulation Patterns in the Mexico City Region

    Directory of Open Access Journals (Sweden)

    Susana Carreón-Sierra

    2015-07-01

    Full Text Available The residents of Mexico City face serious problems of air pollution. Identifying the most representative scenarios for the transport and dispersion of air pollutants requires the knowledge of the main wind circulation patterns. In this paper, a simple method to recognize and characterize the wind circulation patterns in a given region is proposed and applied to the Mexico City winds (2001–2006. This method uses a lattice wind approach to model the local wind events at the meso-β scale, and hierarchical cluster analysis to recognize their agglomerations in their phase space. Data of the meteorological network of Mexico City was used as input for the lattice wind model. The Ward’s clustering algorithm with Euclidean distance was applied to organize the model wind events in seasonal clusters for each year of the period. Comparison of the hourly population trends of these clusters permitted the recognition and detailed description of seven circulation patterns. These patterns resemble the qualitative descriptions of the Mexico City wind circulation modes reported by other authors. Our method, however, permitted also their quantitative characterization in terms of the wind attributes of velocity, divergence and vorticity, and an estimation of their seasonal and annual occurrence probabilities, which never before were quantified.

  8. Generalized Back Propagation for Training Pattern Derivatives

    Czech Academy of Sciences Publication Activity Database

    Šíma, Jiří

    1994-01-01

    Roč. 4, č. 1 (1994), s. 91-98 ISSN 1210-0552 Grant - others:ALTEC(XE) IC-1000 Keywords : back propagation * smoothness constraints * multi-layered network * expert system * explicite kulle * trainning pattern derivatives * generalization

  9. Using wind-deformed conifers to measure wind patterns in alpine transition at GLEES

    Science.gov (United States)

    Robert C. Musselman; Gene L. Wooldridge; Douglas G. Fox; Bernadette H. Connell

    1990-01-01

    The Glacier Lakes Ecosystem Experiments Site (GLEES) is a high-elevation ecosystem in the Snowy Range west of Laramie, WY, that is perceived to be highly sensitive to changes in chemical and physical climate. Deposition of atmospheric chemicals to this ecosystem is, in part, governed by the wind pattern. The GLEES has numerous wind-swept areas where the coniferous...

  10. Martian Dune Ripples as Indicators of Recent Surface Wind Patterns

    Science.gov (United States)

    Johnson, M.; Zimbelman, J. R.

    2015-12-01

    Sand dunes have been shown to preserve the most recent wind patterns in their ripple formations. This investigation continues the manual documentation of ripples on Martian dunes in order to assess surface wind flow. Study sites investigated must have clear HiRISE frames and be able to represent diverse locations across the surface, decided primarily by their spread of latitude and longitude values. Additionally, frames with stereo pairs are preferred because of their ability to create digital terrain models. This will assist in efforts to relate dune slopes and obstacles to ripple patterns. The search and analysis period resulted in 40 study sites with mapped ripples. Lines were drawn perpendicular to ripple crests across three adjacent ripples in order to document both ripple wavelength from line length and inferred wind direction from azimuth. It is not possible to infer a unique wind direction from ripple orientation alone and therefore these inferred directions have a 180 degree ambiguity. Initial results from all study sites support previous observations that the Martian surface has many dune types in areas with adequate sand supply. The complexity of ripple patterns varies greatly across sites as well as within individual sites. Some areas of uniform directionality for hundreds of kilometers suggest a unimodal wind regime while overlapping patterns suggest multiple dominant winds or seasonally varying winds. In most areas, form flow related to dune shape seems to have a large effect on orientation and must be considered along with the dune type. As long as the few steep slip faces on these small dunes are avoided, form flow can be considered the dominant cause of deviation from the regional wind direction. Regional results, wind roses, and comparisons to previous work will be presented for individual sites.

  11. Mars Global Digital Dune Database (MGD3): Global dune distribution and wind pattern observations

    Science.gov (United States)

    Hayward, Rosalyn K.; Fenton, Lori; Titus, Timothy N.

    2014-01-01

    The Mars Global Digital Dune Database (MGD3) is complete and now extends from 90°N to 90°S latitude. The recently released south pole (SP) portion (MC-30) of MGD3 adds ∼60,000 km2 of medium to large-size dark dune fields and ∼15,000 km2 of sand deposits and smaller dune fields to the previously released equatorial (EQ, ∼70,000 km2), and north pole (NP, ∼845,000 km2) portions of the database, bringing the global total to ∼975,000 km2. Nearly all NP dunes are part of large sand seas, while the majority of EQ and SP dune fields are individual dune fields located in craters. Despite the differences between Mars and Earth, their dune and dune field morphologies are strikingly similar. Bullseye dune fields, named for their concentric ring pattern, are the exception, possibly owing their distinctive appearance to winds that are unique to the crater environment. Ground-based wind directions are derived from slipface (SF) orientation and dune centroid azimuth (DCA), a measure of the relative location of a dune field inside a crater. SF and DCA often preserve evidence of different wind directions, suggesting the importance of local, topographically influenced winds. In general however, ground-based wind directions are broadly consistent with expected global patterns, such as polar easterlies. Intriguingly, between 40°S and 80°S latitude both SF and DCA preserve their strongest, though different, dominant wind direction, with transport toward the west and east for SF-derived winds and toward the north and west for DCA-derived winds.

  12. The effect of vegetation patterns on wind-blown mass transport at the regional scale: A wind tunnel experiment

    NARCIS (Netherlands)

    Youssef, F.; Visser, S.; Karssenberg, D.J.; Erpul, G.; Cornelis, W.M.; Gabriels, D.; Poortinga, A.

    2012-01-01

    Abstract Wind erosion is a global environmental problem. Re-vegetating land is a commonly used method to reduce the negative effects of wind erosion. However, there is limited knowledge on the effect of vegetation pattern on wind-blown mass transport. The objective of this study was to investigate

  13. Effects of Temporal Wind Patterns on the Value of Wind-Generated Electricity in California and the Northwest

    Energy Technology Data Exchange (ETDEWEB)

    Wiser, Ryan H; Wiser, Ryan H; Fripp, Matthias

    2008-05-01

    Wind power production is variable, but also has diurnal and seasonal patterns. These patterns differ between sites, potentially making electric power from some wind sites more valuable for meeting customer loads or selling in wholesale power markets. This paper investigates whether the timing of wind significantly affects the value of electricity from sites in California and the Northwestern United States. We use both measured and modeled wind data and estimate the time-varying value of wind power with both financial and load-based metrics. We find that the potential difference in wholesale market value between better-correlated and poorly correlated wind sites is modest, on the order of 5-10 percent. A load-based metric, power production during the top 10 percent of peak load hours, varies more strongly between sites, suggesting that the capacity value of different wind projects could vary by as much as 50 percent based on the timing of wind alone.

  14. Determining the impact of wind on system costs via the temporal patterns of load and wind generation

    International Nuclear Information System (INIS)

    Davis, Clay D.; Gotham, Douglas J.; Preckel, Paul V.; Liu, Andrew L.

    2013-01-01

    Ambitious targets have been set for expanding electricity generation from renewable sources, including wind. Expanding wind power impacts needs for other electricity generating resources. As states plan for increasing levels of wind generation in their portfolio of generation resources it is important to consider how this intermittent resource impacts the need for other generation resources. A case study for Indiana estimates the value of wind capacity and demonstrates how to optimize its level and the levels of other generation resources. Changes are driven by temporal patterns of wind power output and load. System wide impacts are calculated for energy, capacity, and costs under multiple wind expansion scenarios which highlight the geographic characteristics of a systems portfolio of wind generation. The impacts of carbon prices, as proposed in the Bingaman Bill, are considered. Finally, calculations showing the effect increasing levels of wind generation will have on end use Indiana retail rates are included. - Highlights: • We estimate the value of wind capacity. • We determine wind generation's impact on the optimal mix of non-wind generation. • Optimal levels of wind and non-wind generation are determined. • We consider the impact of a carbon price on the optimal mix of resources. • The impact of additional wind capacity on Indiana residential rates is calculated

  15. Measurement of global oceanic winds from Seasat-SMMR and its comparison with Seasat-SASS and ALT derived winds

    Science.gov (United States)

    Pandey, Prem C.

    1987-01-01

    The retrieval of ocean-surface wind speed from different channel combinations of Seasat SMMR measurements is demonstrated. Wind speeds derived using the best two channel subsets (10.6 H and 18.0 V) were compared with in situ data collected during the Joint Air-Sea Interaction (JASIN) experiment and an rms difference of 1.5 m/s was found. Global maps of wind speed generated with the present algorithm show that the averaged winds are arranged in well-ordered belts.

  16. Analysis of wind speed distributions: Wind distribution function derived from minimum cross entropy principles as better alternative to Weibull function

    International Nuclear Information System (INIS)

    Kantar, Yeliz Mert; Usta, Ilhan

    2008-01-01

    In this study, the minimum cross entropy (MinxEnt) principle is applied for the first time to the wind energy field. This principle allows the inclusion of previous information of a wind speed distribution and covers the maximum entropy (MaxEnt) principle, which is also discussed by Li and Li and Ramirez as special cases in their wind power study. The MinxEnt probability density function (pdf) derived from the MinxEnt principle are used to determine the diurnal, monthly, seasonal and annual wind speed distributions. A comparison between MinxEnt pdfs defined on the basis of the MinxEnt principle and the Weibull pdf on wind speed data, which are taken from different sources and measured in various regions, is conducted. The wind power densities of the considered regions obtained from Weibull and MinxEnt pdfs are also compared. The results indicate that the pdfs derived from the MinxEnt principle fit better to a variety of measured wind speed data than the conventionally applied empirical Weibull pdf. Therefore, it is shown that the MinxEnt principle can be used as an alternative method to estimate both wind distribution and wind power accurately

  17. Atmospheric circulation patterns associated with strong wind events in Catalonia

    Directory of Open Access Journals (Sweden)

    J. C. Peña

    2011-01-01

    Full Text Available The benefit of having a daily synoptic weather type catalogue and even more, a detailed catalogue for high impact weather events is well recognised by both climatologist and meteorologist communities. In this way the Meteorological Service of Catalonia (SMC has produced some accurate classifications for extreme events, such as hailstorms or strong winds (SW. Within the framework of the MEDEX project, the SMC has been collaborating to increase the level of awareness about these events. Following this line of work, the aim of this study is to characterise the SW events in Catalonia.

    According to the guidelines of the MEDEX project we worked with its SW event database for the period June 1995 to May 2004. We also used the period 2005–2009 to test the methodology. The methodology is based on principal component, cluster and discriminant analyses and applied to four variables: SLP, temperature at 850 hPa and geopotential at 500 hPa on a synoptic-scale and local gust wind. We worked with ERA-Interim reanalysis and applied discriminant analysis to test the quality of the methodology and to classify the events of the validation period.

    We found seven patterns for the SW events. The strongest event corresponds to NW-Flow with the Azores Anticyclone and the passing of a low pressure through the Pyrenees. This methodology has distinguished the summer events in an independent cluster. The results obtained encourage us to follow this line of work.

  18. Long-term variability of wind patterns at hub-height over Texas

    Science.gov (United States)

    Jung, J.; Jeon, W.; Choi, Y.; Souri, A.

    2017-12-01

    Wind energy is getting more attention because of its environmentally friendly attributes. Texas is a state with significant capacity and number of wind turbines. Wind power generation is significantly affected by wind patterns, and it is important to understand this seasonal and decadal variability for long-term power generation from wind turbines. This study focused on the trends of changes in wind pattern and its strength at two hub-heights (80 m and 110 m) over 30-years (1986 to 2015). We only analyzed summer data(June to September) because of concentrated electricity usage in Texas. We extracted hub-height wind data (U and V components) from the three-hourly National Centers for Environmental Prediction-North American Regional Reanalysis (NCEP-NARR) and classified wind patterns properly by using nonhierarchical K-means method. Hub-height wind patterns in summer seasons of 1986 to 2015 were classified in six classes at day and seven classes at night. Mean wind speed was 4.6 ms-1 at day and 5.4 ms-1 at night, but showed large variability in time and space. We combined each cluster's frequencies and wind speed tendencies with large scale atmospheric circulation features and quantified the amount of wind power generation.

  19. The use of energy pattern factor (EPF) in estimating wind power ...

    African Journals Online (AJOL)

    The Energy Pattern Factor (EPF) method is a less computational method of estimating the available wind power density of an area and wind speed variation account for the energy power density throughout a given period. Using the Average daily wind speed data for an 11 year period (2004-2014) obtained from the ...

  20. the use of energy pattern factor (epf) in estimating wind power density

    African Journals Online (AJOL)

    Dogara M. D et. al

    Factor of Kaduna was estimated to be 1.03 and from the energy pattern factor, the average annual available wind power density was calculated to be 222.13 W/m2. This calculated wind power density falls within the stipulated values under wind power class 4 of the National Renewable Energy Laboratory (NREL) of the US.

  1. Spatial and temporal patterns of global onshore wind speed distribution

    International Nuclear Information System (INIS)

    Zhou, Yuyu; Smith, Steven J

    2013-01-01

    Wind power, a renewable energy source, can play an important role in electrical energy generation. Information regarding wind energy potential is important both for energy related modeling and for decision-making in the policy community. While wind speed datasets with high spatial and temporal resolution are often ultimately used for detailed planning, simpler assumptions are often used in analysis work. An accurate representation of the wind speed frequency distribution is needed in order to properly characterize wind energy potential. Using a power density method, this study estimated global variation in wind parameters as fitted to a Weibull density function using NCEP/climate forecast system reanalysis (CFSR) data over land areas. The Weibull distribution performs well in fitting the time series wind speed data at most locations according to R 2 , root mean square error, and power density error. The wind speed frequency distribution, as represented by the Weibull k parameter, exhibits a large amount of spatial variation, a regionally varying amount of seasonal variation, and relatively low decadal variation. We also analyzed the potential error in wind power estimation when a commonly assumed Rayleigh distribution (Weibull k = 2) is used. We find that the assumption of the same Weibull parameter across large regions can result in non-negligible errors. While large-scale wind speed data are often presented in the form of mean wind speeds, these results highlight the need to also provide information on the wind speed frequency distribution. (letter)

  2. A diagnostic approach to obtaining planetary boundary layer winds using satellite-derived thermal data

    Science.gov (United States)

    Belt, Carol L.; Fuelberg, Henry E.

    1984-01-01

    The feasibility of using satellite derived thermal data to generate realistic synoptic scale winds within the planetary boundary layer (PBL) is examined. Diagnostic modified Ekman wind equations from the Air Force Global Weather Central (AFGWC) Boundary Layer Model are used to compute winds at seven levels within the PBL transition layer (50 m to 1600 m AGL). Satellite derived winds based on 62 predawn TIROS-N soundings are compared to similarly derived wind fields based on 39 AVE-SESAME II rawinsonde (RAOB) soundings taken 2 h later. Actual wind fields are also used as a basis for comparison. Qualitative and statistical comparisons show that the Ekman winds from both sources are in very close agreement, with an average vector correlation coefficient of 0.815. Best results are obtained at 300 m AGL. Satellite winds tend to be slightly weaker than their RAOB counterparts and exhibit a greater degree of cross-isobaric flow. The modified Ekman winds show a significant improvement over geostrophic values at levels nearest the surface.

  3. Satellite-Derived Water Vapor Winds for Regional Climate Studies

    Science.gov (United States)

    Jedlovce, Gary J.; Lerner, Jeffery A.; Iwai, Hisaki; Haines, Stephanie

    1999-01-01

    The retrieval of winds and humidity in the upper-troposphere has matured to the point where it may now be possible to better understand and diagnose regional climate variations from geostationary satellites than from conventional measurements or model analysis, especially in data sparse regions. In this poster paper, upper-tropospheric circulation features and moisture transport covering ENSO periods are presented and discussed. Precursor and other detectable interannual climate signals are analyzed and compared to model diagnosed features. Estimates of winds and humidity over data-rich regions (from conventional measurements) are used to show the robustness of the data and its value over regions which are currently poorly sampled.

  4. Application of Satellite-Derived Ocean Surface Winds to the Detection of Weather Systems and the Prediction of Near-Ocean Surface Winds around Hawaii

    Directory of Open Access Journals (Sweden)

    Hsi-Chyi Yeh

    2010-01-01

    Full Text Available The Hawaiian Island chain is surrounded by the open ocean and is an ideal place to conduct the application of QuikSCAT satellite-derived ocean surface winds to the detection of weather systems. With the help of QuikSCAT winds, the associated circulation of the weather systems over the open ocean around Hawaii can be identified. In this study, the obvious cyclonic circulation associated with a Kona storm, the significant wind shift and wind confluence related to the surface cold front, and the anticyclonic circulation related to high-pressure systems for both a strong-wind event and a trade-wind condition are revealed over the open ocean through QuikSCAT winds. The propagation of a cold frontal boundary, defined by the wind shift and wind confluence, also can be clearly detected using the reanalyzed ocean-surface winds.

  5. Wind Patterns of Coastal Tanzania: Their Variability and Trends ...

    African Journals Online (AJOL)

    Generally, the wind speeds were significantly correlated with the El-Niño Southern Oscillation and the Pacific Decadal Oscillation, while at Mtwara the winds were also correlated with the Indian Ocean Dipole. These correlations were higher during the SE Monsoon than during the NE Monsoon. Trends in the monthly mean ...

  6. Wind barriers suppress fugitive dust and soil-derived airborne particles in arid regions

    Energy Technology Data Exchange (ETDEWEB)

    Grantz, D.A.; Vaughn, D.L. [Univ. of California, Parlier, CA (United States). Kearney Agricultural Center; Farber, R.J. [SoCal Edison, Rosemead, CA (United States). Environmental Research Div.; Kim, B. [South Coast Air Quality Management District, Diamond Bar, CA (United States); Ashbaugh, L. [Univ. of California, Davis, CA (United States). Crocker Nuclear Lab.; Van Curen, T. [California Air Resources Board, Sacramento, CA (United States); Campbell, R. [Antelope Valley Resources Conservation District, Lancaster, CA (United States)

    1998-07-01

    Areas of abandoned agricultural land in the Antelope Valley, western Mojave (high) desert of California have proven in the previous studies to be recalcitrant to conventional tillage and revegetation strategies designed to suppress wind erosion of soil and transport of sediment and fugitive dust. These areas represented a continuing source of drifting sand and of coarse and respirable suspended particulate matter. The traditional techniques failed because furrows collapsed and the water holding capacity of the overburden was too low to support seed germination and transplant survival. In this study a variety of wind barriers were evaluated for suppression of sediment transport. Airborne particles were measured with an array of coarse particle samplers at heights of 0.2, 1.0, and 2.0 m above the soil surface. Discrete artificial wind barriers, consisting of widely spaced roughness elements were effective in suppressing fugitive emissions. Wind fences established along the leeward edge of an area of blowing sand, perpendicular to the prevailing wind, significantly decreased fugitive emissions. Control was greatest and precision of the measurements was highest under high wind conditions. These techniques provide rapid and effective suppression of fugitive emissions of soil-derived particles under conditions that resist conventional tillage and revegetation techniques. A simple, indirect procedure for determining local wind velocity erosion thresholds requiring only sampling of wind run and suspended particulate mass compared favorably with direct measurement of saltation as a function of wind velocity.

  7. Effects of El Niño-driven changes in wind patterns on North Pacific albatrosses.

    Science.gov (United States)

    Thorne, L H; Conners, M G; Hazen, E L; Bograd, S J; Antolos, M; Costa, D P; Shaffer, S A

    2016-06-01

    Changes to patterns of wind and ocean currents are tightly linked to climate change and have important implications for cost of travel and energy budgets in marine vertebrates. We evaluated how El Niño-Southern Oscillation (ENSO)-driven wind patterns affected breeding Laysan and black-footed albatross across a decade of study. Owing to latitudinal variation in wind patterns, wind speed differed between habitat used during incubation and brooding; during La Niña conditions, wind speeds were lower in incubating Laysan (though not black-footed) albatross habitat, but higher in habitats used by brooding albatrosses. Incubating Laysan albatrosses benefited from increased wind speeds during El Niño conditions, showing increased travel speeds and mass gained during foraging trips. However, brooding albatrosses did not benefit from stronger winds during La Niña conditions, instead experiencing stronger cumulative headwinds and a smaller proportion of trips in tailwinds. Increased travel costs during brooding may contribute to the lower reproductive success observed in La Niña conditions. Furthermore, benefits of stronger winds in incubating habitat may explain the higher reproductive success of Laysan albatross during El Niño conditions. Our findings highlight the importance of considering habitat accessibility and cost of travel when evaluating the impacts of climate-driven habitat change on marine predators. © 2016 The Author(s).

  8. Changes in wind pattern alter albatross distribution and life-history traits.

    Science.gov (United States)

    Weimerskirch, Henri; Louzao, Maite; de Grissac, Sophie; Delord, Karine

    2012-01-13

    Westerly winds in the Southern Ocean have increased in intensity and moved poleward. Using long-term demographic and foraging records, we show that foraging range in wandering albatrosses has shifted poleward in conjunction with these changes in wind pattern, while their rates of travel and flight speeds have increased. Consequently, the duration of foraging trips has decreased, breeding success has improved, and birds have increased in mass by more than 1 kilogram. These positive consequences of climate change may be temporary if patterns of wind in the southern westerlies follow predicted climate change scenarios. This study stresses the importance of foraging performance as the key link between environmental changes and population processes.

  9. FACE RECOGNITION BASED ON LOCAL DERIVATIVE TETRA PATTERN

    Directory of Open Access Journals (Sweden)

    A Geetha

    2017-02-01

    Full Text Available This paper proposes a new face recognition algorithm called local derivative tetra pattern (LDTrP. The new technique LDTrP is used to alleviate the face recognition rate under real-time challenges. Local derivative pattern (LDP is a directional feature extraction method to encode directional pattern features based on local derivative variations. The nth -order LDP is proposed to encode the first (n-1th order local derivative direction variations. The LDP templates extract high-order local information by encoding various distinctive spatial relationships contained in a given local region. The local tetra pattern (LTrP encodes the relationship between the reference pixel and its neighbours by using the first-order derivatives in vertical and horizontal directions. LTrP extracts values which are based on the distribution of edges which are coded using four directions. The LDTrP combines the higher order directional feature from both LDP and LTrP. Experimental results on ORL and JAFFE database show that the performance of LDTrP is consistently better than LBP, LTP and LDP for face identification under various conditions. The performance of the proposed method is measured in terms of recognition rate.

  10. Decadal changes in wind patterns impact on high PM10 concentration in the Korean Peninsula

    Science.gov (United States)

    Lee, T.; Jeon, W.; Lee, H.; Lee, S.

    2017-12-01

    Principal component analysis is a statistical method that can be used not only to analyze the principal components of data, but also to reduce dimensionality and remove noise of data. And K-means cluster analysis is one of the commonly used non-hierarchical cluster analysis methods, which classifies clusters based on distance between data. In order to classify the wind patterns impact on high PM10 concentration in the Korean Peninsula, K-means cluster analysis was performed with reproducing the data using principal component analysis. We analyzed the decadal changes in the wind patterns around the Korean Peninsula and their impact on PM10 concentration. For the analysis, we obtained 900 hPa wind fields from the FNL analysis data and classified the specific patterns causing the PM10 episodes in the Korean Peninsula during the recent 10 years (2007-2016). We then investigated how the varying wind patterns affected the changes in the PM10 concentrations from past to present. The cluster analysis results indicated that the high PM10 episodes in the Korean Peninsula was strongly affected by winds from southwest and northwest, causing the PM10 transport from China to the Korean Peninsula. We also found that the wind patterns causing the high PM10 shows clear annual variation during the recent 10 years.

  11. Analytical Derivation of Electrical-Side Maximum Power Line for Wind Generators

    Directory of Open Access Journals (Sweden)

    Sergei Kolesnik

    2017-09-01

    Full Text Available In order to enhance the maximum power point tracking (MPPT speed of solar generators, offline calculated maximum power line (MPL is often used as a feed-forward signal added to the output of MPPT controller. MPL is nonlinear static electrical characteristic of renewable energy generators connecting all the maximum power points for given temperature. In this letter, electrical side MPL is derived for a typical wind turbine generator (WTG. It is shown that MPLs of solar and wind generators possess similar structure, supporting the similarity between the two energy conversion processes.

  12. [Influences of land using patterns on the anti-wind erosion of meadow grassland].

    Science.gov (United States)

    Zhou, Yao-Zhi; Wang-Xu; Yang, Gui-Xia; Xin, Xiao-Ping

    2008-05-01

    In order to analyse the effects of the human disturbances to the ability of anti-wind erosion of the Hulunbuir meadow grassland, the methods of vegetation investigation and the wind tunnel experiment were made to research the changes of vegetation and the abilities of anti-wind erosion of meadow grassland under different using patterns of meadow grassland. The results indicate that, under different grazing intensities of meadow grassland, the critical wind velocity of soil erosion (v) changes with the vegetation cover according to the relation of second power function. Along with the grazing intensities increasing and the vegetation cover reducing, the velocity of soil erosion rapidly increased on the condition of similar wind velocity which is speedier than the critical wind velocity of soil erosion. When the meadow grassland is mildly grazed which the vegetation cover maintains 63%, the velocity of soil erosion is small even there is gale that the wind velocity reach 25 m/s. When the vegetation cover of meadow grassland reduced to less than 35%, the velocity of soil erosion rapidly increased with the vegetation cover's reducing on the condition of the wind velocity is among 20-25 m/s. And owing to the no-tillage cropland of meadow grassland is completely far from the protection of the vegetation, the soil wind erosion quantity achieves 682.1 kg/hm2 in a minute when the wind velocity is 25 m/s, which approaches the average formation quantity of soil (1 000 kg/hm2) in a year.

  13. Average thermospheric wind patterns over the polar regions, as observed by CHAMP

    Directory of Open Access Journals (Sweden)

    H. Lühr

    2007-06-01

    Full Text Available Measurements of the CHAMP accelerometer are utilized to investigate the average thermospheric wind distribution in the polar regions at altitudes around 400 km. This study puts special emphasis on the seasonal differences in the wind patterns. For this purpose 131 days centered on the June solstice of 2003 are considered. Within that period CHAMP's orbit is precessing once through all local times. The cross-track wind estimates of all 2030 passes are used to construct mean wind vectors for 918 equal-area cells. These bin averages are presented in corrected geomagnetic coordinates. Both hemispheres are considered simultaneously providing summer and winter responses for the same prevailing geophysical conditions. The period under study is characterized by high magnetic activity (Kp=4− but moderate solar flux level (F10.7=124. Our analysis reveals clear wind features in the summer (Northern Hemisphere. Over the polar cap there is a fast day-to-night flow with mean speeds surpassing 600 m/s in the dawn sector. At auroral latitudes we find strong westward zonal winds on the dawn side. On the dusk side, however, an anti-cyclonic vortex is forming. The dawn/dusk asymmetry is attributed to the combined action of Coriolis and centrifugal forces. Along the auroral oval the sunward streaming plasma causes a stagnation of the day-to-night wind. This effect is particularly clear on the dusk side. On the dawn side it is evident only from midnight to 06:00 MLT. The winter (Southern Hemisphere reveals similar wind features, but they are less well ordered. The mean day-to-night wind over the polar cap is weaker by about 35%. Otherwise, the seasonal differences are mainly confined to the dayside (06:00–18:00 MLT. In addition, the larger offset between geographic and geomagnetic pole in the south also causes hemispheric differences of the thermospheric wind distribution.

  14. Average thermospheric wind patterns over the polar regions, as observed by CHAMP

    Directory of Open Access Journals (Sweden)

    H. Lühr

    2007-06-01

    Full Text Available Measurements of the CHAMP accelerometer are utilized to investigate the average thermospheric wind distribution in the polar regions at altitudes around 400 km. This study puts special emphasis on the seasonal differences in the wind patterns. For this purpose 131 days centered on the June solstice of 2003 are considered. Within that period CHAMP's orbit is precessing once through all local times. The cross-track wind estimates of all 2030 passes are used to construct mean wind vectors for 918 equal-area cells. These bin averages are presented in corrected geomagnetic coordinates. Both hemispheres are considered simultaneously providing summer and winter responses for the same prevailing geophysical conditions. The period under study is characterized by high magnetic activity (Kp=4− but moderate solar flux level (F10.7=124. Our analysis reveals clear wind features in the summer (Northern Hemisphere. Over the polar cap there is a fast day-to-night flow with mean speeds surpassing 600 m/s in the dawn sector. At auroral latitudes we find strong westward zonal winds on the dawn side. On the dusk side, however, an anti-cyclonic vortex is forming. The dawn/dusk asymmetry is attributed to the combined action of Coriolis and centrifugal forces. Along the auroral oval the sunward streaming plasma causes a stagnation of the day-to-night wind. This effect is particularly clear on the dusk side. On the dawn side it is evident only from midnight to 06:00 MLT. The winter (Southern Hemisphere reveals similar wind features, but they are less well ordered. The mean day-to-night wind over the polar cap is weaker by about 35%. Otherwise, the seasonal differences are mainly confined to the dayside (06:00–18:00 MLT. In addition, the larger offset between geographic and geomagnetic pole in the south also causes hemispheric differences of the thermospheric wind distribution.

  15. Anomalous Arctic surface wind patterns and their impacts on September sea ice minima and trend

    Directory of Open Access Journals (Sweden)

    Bingyi Wu

    2012-05-01

    Full Text Available We used monthly mean surface wind data from the National Centers for Environmental Prediction/National Centers for Atmospheric Research (NCEP/NCAR reanalysis dataset during the period 1979–2010 to describe the first two patterns of Arctic surface wind variability by means of the complex vector empirical orthogonal function (CVEOF analysis. The first two patterns respectively account for 31 and 16% of its total anomalous kinetic energy. The leading pattern consists of the two subpatterns: the northern Laptev Sea (NLS pattern and the Arctic dipole (AD pattern. The second pattern contains the northern Kara Sea (NKS pattern and the central Arctic (CA pattern. Over the past two decades, the combined dynamical forcing of the first two patterns has contributed to Arctic September sea ice extent (SIE minima and its declining trend. September SIE minima are mainly associated with the negative phase of the AD pattern and the positive phase of the CA pattern during the summer (July to September season, and both phases coherently show an anomalous anticyclone over the Arctic Ocean. Wind patterns affect September SIE through their frequency and intensity. The negative trend in September SIE over the past two decades is associated with increased frequency and enhanced intensity of the CA pattern during the melting season from April to September. Thus, it cannot be simply attributed to the AD anomaly characterised by the second empirical orthogonal function mode of sea level pressure north of 70°N. The CA pattern exhibited interdecadal variability in the late 1990s, and an anomalous cyclone prevailed before 1997 and was then replaced by an anomalous anticyclone over the Arctic Ocean that is consistent with the rapid decline trend in September SIE. This paper provides an alternative way to identify the dominant patterns of climate variability and investigate their associated Arctic sea ice variability from a dynamical perspective. Indeed, this study

  16. Advanced Modeling System for Optimization of Wind Farm Layout and Wind Turbine Sizing Using a Multi-Level Extended Pattern Search Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    DuPont, Bryony; Cagan, Jonathan; Moriarty, Patrick

    2016-07-01

    This paper presents a system of modeling advances that can be applied in the computational optimization of wind plants. These modeling advances include accurate cost and power modeling, partial wake interaction, and the effects of varying atmospheric stability. To validate the use of this advanced modeling system, it is employed within an Extended Pattern Search (EPS)-Multi-Agent System (MAS) optimization approach for multiple wind scenarios. The wind farm layout optimization problem involves optimizing the position and size of wind turbines such that the aerodynamic effects of upstream turbines are reduced, which increases the effective wind speed and resultant power at each turbine. The EPS-MAS optimization algorithm employs a profit objective, and an overarching search determines individual turbine positions, with a concurrent EPS-MAS determining the optimal hub height and rotor diameter for each turbine. Two wind cases are considered: (1) constant, unidirectional wind, and (2) three discrete wind speeds and varying wind directions, each of which have a probability of occurrence. Results show the advantages of applying the series of advanced models compared to previous application of an EPS with less advanced models to wind farm layout optimization, and imply best practices for computational optimization of wind farms with improved accuracy.

  17. Dune field pattern formation and recent transporting winds in the Olympia Undae Dune Field, north polar region of Mars

    Science.gov (United States)

    Ewing, Ryan C.; Peyret, Aymeric-Pierre B.; Kocurek, Gary; Bourke, Mary

    2010-08-01

    High-Resolution Imaging Science Experiment (HiRISE) imagery of the central Olympia Undae Dune Field in the north polar region of Mars shows a reticulate dune pattern consisting of two sets of nearly orthogonal dune crestlines, with apparent slipfaces on the primary crests, ubiquitous wind ripples, areas of coarse-grained wind ripples, and deflated interdune areas. Geomorphic evidence and dune field pattern analysis of dune crest length, spacing, defect density, and orientation indicates that the pattern is complex, representing two constructional generations of dunes. The oldest and best-organized generation forms the primary crestlines and is transverse to circumpolar easterly winds. Gross bed form-normal analysis of the younger pattern of crestlines indicates that it emerged with both circumpolar easterly winds and NE winds and is reworking the older pattern. Mapping of secondary flow fields over the dunes indicates that the most recent transporting winds were from the NE. The younger pattern appears to represent an influx of sediment to the dune field associated with the development of the Olympia Cavi reentrant, with NE katabatic winds channeling through the reentrant. A model of the pattern reformation based upon the reconstructed primary winds and resulting secondary flow fields shows that the development of the secondary pattern is controlled by the boundary condition of the older dune topography.

  18. Impacts of Landscape Context on Patterns of Wind Downfall Damage in a Fragmented Amazonian Landscape

    Science.gov (United States)

    Schwartz, N.; Uriarte, M.; DeFries, R. S.; Gutierrez-Velez, V. H.; Fernandes, K.; Pinedo-Vasquez, M.

    2015-12-01

    Wind is a major disturbance in the Amazon and has both short-term impacts and lasting legacies in tropical forests. Observed patterns of damage across landscapes result from differences in wind exposure and stand characteristics, such as tree stature, species traits, successional age, and fragmentation. Wind disturbance has important consequences for biomass dynamics in Amazonian forests, and understanding the spatial distribution and size of impacts is necessary to quantify the effects on carbon dynamics. In November 2013, a mesoscale convective system was observed over the study area in Ucayali, Peru, a highly human modified and fragmented forest landscape. We mapped downfall damage associated with the storm in order to ask: how does the severity of damage vary within forest patches, and across forest patches of different sizes and successional ages? We applied spectral mixture analysis to Landsat images from 2013 and 2014 to calculate the change in non-photosynthetic vegetation fraction after the storm, and combined it with C-band SAR data from the Sentinel-1 satellite to predict downfall damage measured in 30 field plots using random forest regression. We then applied this model to map damage in forests across the study area. Using a land cover classification developed in a previous study, we mapped secondary and mature forest, and compared the severity of damage in the two. We found that damage was on average higher in secondary forests, but patterns varied spatially. This study demonstrates the utility of using multiple sources of satellite data for mapping wind disturbance, and adds to our understanding of the sources of variation in wind-related damage. Ultimately, an improved ability to map wind impacts and a better understanding of their spatial patterns can contribute to better quantification of carbon dynamics in Amazonian landscapes.

  19. Wind patterns associated with the development of daytime thunderstorms over Istria

    Directory of Open Access Journals (Sweden)

    G. Poljak

    2014-04-01

    Full Text Available The northeastern (NE Adriatic in the northern Mediterranean is the area with (i the highest frequency of thunderstorms in Croatia, and (ii frequent appearances of sea breeze (SB along the coast. This study investigates the impact of the combined large-scale wind (associated with particular synoptic conditions and the SB on the moist convection development over the NE Adriatic. The four selected cases were (i chosen on the basis of a daytime moist convection; (ii supplemented by one of the dominant large-scale winds with seaward (NE, NW and landward (SW, SE directions and (iii simulated by WRF numerical model. The near-surface wind patterns consisted of SBs along the coastline, generated a narrow eastward-moving convergence zone (CZ along the area if the large-scale wind was less than 9 m s−1 (below 500 hPa. Apart from the low-level CZ, the advection of large-scale wind influenced the lifetime and movement of the initial Cb cells. While the local front collision with the NE wind advection caused the thunderstorm to propagate southward, the CZ and fronts interaction determined the afternoon northwestward storm movement against the NW large-scale wind. Due to particular synoptic background, the thunderstorm event in SE case was the shortest with only a minor impact on the SB. While the origins and locations of storm cells were completely controlled by the low-level CZ and the upward advection of low-level moisture at the SB front, the most typical convective case with SW warm-wet wind only partially supported the SB–Cb interaction.

  20. Empirically derived dietary patterns in relation to psychological disorders.

    Science.gov (United States)

    Hosseinzadeh, Mahdieh; Vafa, Mohammadreza; Esmaillzadeh, Ahmad; Feizi, Awat; Majdzadeh, Reza; Afshar, Hamidreza; Keshteli, Ammar Hassanzadeh; Adibi, Peyman

    2016-02-01

    Psychological disorders are highly prevalent worldwide. The present study aimed to investigate the relationship between major dietary patterns and prevalence of psychological disorders in a large sample of Iranian adults. A cross-sectional study was done to identify dietary patterns derived from factor analysis. Dietary data were collected through the use of a validated dish-based semi-quantitative FFQ. Psychological health was examined by use of the Hospital Anxiety and Depression Scale and the General Health Questionnaire. The study was conducted in Isfahan, Iran, within the framework of the Study on Epidemiology of Psychological, Alimentary Health and Nutrition (SEPAHAN). Iranian adults (n 3846) aged 20-55 years. After adjustment for potential confounders, greater adherence to the lacto-vegetarian dietary pattern was protectively associated with depression in women (OR=0·65; 95 % CI 0·46, 0·91). Normal-weight participants in the top quintile of this dietary pattern tended to have decreased odds of anxiety compared with those in the bottom quintile (OR=0·61; 95 % CI 0·38, 1·00). In addition, the traditional dietary pattern was associated with increased odds of depression (OR=1·42; 95 % CI 1·01, 1·99) and anxiety (OR=1·56; 95 % CI 1·00, 2·42) in women. Normal-weight participants in the highest quintile of the traditional dietary pattern had greater odds for anxiety (OR=1·89; 95 % CI 1·12, 3·08) compared with those in the lowest quintile. The Western dietary pattern was associated with increased odds of depression in men (OR=1·73; 95 % CI 1·07, 2·81) and anxiety in normal-weight participants (OR=2·05; 95 % CI 1·22, 3·46). There was a significant increasing trend in the odds of psychological distress across increasing quintiles of the fast food dietary pattern in women (P-trend=0·02). Recommendation to increase the intake of fruits, citrus fruits, vegetables, tomato and low-fat dairy products and to reduce the intakes of snacks, high-fat dairy

  1. Comparison of wind and wind shear climatologies derived from high-resolution radiosondes and the ECMWF model

    Science.gov (United States)

    Houchi, K.; Stoffelen, A.; Marseille, G. J.; de Kloe, J.

    2010-11-01

    The climatology of atmospheric horizontal wind and its vertical gradient, i.e., wind shear, is characterized as a function of climate region. For a better representation of the average atmospheric wind and shear and their variabilities, high-resolution radiosonde wind profiles up to about 30 km altitude are compared with the collocated operational ECMWF model for short-range forecast winds. Statistics of zonal and meridional winds are established from both data sets. The results show mainly similarity in the probability distributions of the modeled and observed horizontal winds, practically at all levels of the atmosphere, while at the same time the vertical shear of the wind is substantially underestimated in the model. The comparison of shear statistics of radiosonde and ECMWF model winds shows that the model wind shear mean and variability are on average a factor of 2.5 (zonal) and 3 (meridional) smaller than of radiosondes in the free troposphere, while in the stratosphere, the planetary boundary layer results are more variable. By applying vertical averaging to the radiosonde data, it is found that the effective vertical resolution of the ECMWF model is typically 1.7 km. Moreover, it is found for individually collocated radiosonde model wind and shear profiles that the model wind may lack in some cases variability larger than 5 m s-1 and 0.015 s-1, respectively, due mainly to the effect of lacking vertical resolution, in particular near the jets. Besides the general importance of this study in highlighting the difference in the representation of the atmospheric wind shear by model and observations, it is more specifically relevant for the future Atmospheric Dynamics Mission (ADM-Aeolus) of the European Space Agency due for launch in 2012. The results presented here are used to generate a realistic global atmospheric database, which is necessary to conduct simulations of the Aeolus Doppler wind lidar in order optimize its vertical sampling and processing.

  2. Comparison of Ares I-X Wind-Tunnel Derived Buffet Environment with Flight Data

    Science.gov (United States)

    Piatak, David J.; Sekula, Martin K.; Rausch, Russ D.

    2011-01-01

    The Ares I-X Flight Test Vehicle (FTV), launched in October 2009, carried with it over 243 buffet verification pressure sensors and was one of the most heavily instrumented launch vehicle flight tests. This flight test represented a unique opportunity for NASA and its partners to compare the wind-tunnel derived buffet environment with that measured during the flight of Ares I-X. It is necessary to define the launch vehicle buffet loads to ensure that structural components and vehicle subsystems possess adequate strength, stress, and fatigue margins when the vehicle structural dynamic response to buffet forcing functions are considered. Ares I-X buffet forcing functions were obtained via wind-tunnel testing of a rigid buffet model (RBM) instrumented with hundreds of unsteady pressure transducers designed to measure the buffet environment across the desired frequency range. This paper discusses the comparison of RBM and FTV buffet environments, including fluctuating pressure coefficient and normalized sectional buffet forcing function root-mean-square magnitudes, frequency content of power-spectral density functions, and force magnitudes of an alternating flow phenomena. Comparison of wind-tunnel model and flight test vehicle buffet environments show very good agreement with root-mean-square magnitudes of buffet forcing functions at the majority of vehicle stations. Spectra proved a challenge to compare because of different wind-tunnel and flight test conditions and data acquisition rates. However, meaningful and promising comparisons of buffet spectra are presented. Lastly, the buffet loads resulting from the transition of subsonic separated flow to supersonic attached flow were significantly over-predicted by wind-tunnel results.

  3. On damage diagnosis for a wind turbine blade using pattern recognition

    Science.gov (United States)

    Dervilis, N.; Choi, M.; Taylor, S. G.; Barthorpe, R. J.; Park, G.; Farrar, C. R.; Worden, K.

    2014-03-01

    With the increased interest in implementation of wind turbine power plants in remote areas, structural health monitoring (SHM) will be one of the key cards in the efficient establishment of wind turbines in the energy arena. Detection of blade damage at an early stage is a critical problem, as blade failure can lead to a catastrophic outcome for the entire wind turbine system. Experimental measurements from vibration analysis were extracted from a 9 m CX-100 blade by researchers at Los Alamos National Laboratory (LANL) throughout a full-scale fatigue test conducted at the National Renewable Energy Laboratory (NREL) and National Wind Technology Center (NWTC). The blade was harmonically excited at its first natural frequency using a Universal Resonant EXcitation (UREX) system. In the current study, machine learning algorithms based on Artificial Neural Networks (ANNs), including an Auto-Associative Neural Network (AANN) based on a standard ANN form and a novel approach to auto-association with Radial Basis Functions (RBFs) networks are used, which are optimised for fast and efficient runs. This paper introduces such pattern recognition methods into the wind energy field and attempts to address the effectiveness of such methods by combining vibration response data with novelty detection techniques.

  4. Wind tunnel investigation of active controls technology applied to a DC-10 derivative

    Science.gov (United States)

    Winther, B. A.; Shirley, W. A.; Heimbaugh, R. M.

    1980-01-01

    Application of active controls technology to reduce aeroelastic response offers a potential for significant payoffs in terms of aerodynamic efficiency and structural weight. As part of the NASA Energy Efficient Transport program, the impact upon flutter and gust load characteristics has been investigated by means of analysis and low-speed wind tunnel tests of a semispan model. The model represents a DC-10 derivative with increased wing span and an active aileron surface, responding to vertical acceleration at the wing tip. A control law satisfying both flutter and gust load constraints is presented and evaluated. In general, the beneficial effects predicted by analysis are in good agreement with experimental data.

  5. Global Patterns of Lightning Properties Derived by OTD and LIS

    Science.gov (United States)

    Beirle, Steffen; Koshak, W.; Blakeslee, R.; Wagner, T.

    2014-01-01

    The satellite instruments Optical Transient Detector (OTD) and Lightning Imaging Sensor (LIS) provide unique empirical data about the frequency of lightning flashes around the globe (OTD), and the tropics (LIS), which 5 has been used before to compile a well received global climatology of flash rate densities. Here we present a statistical analysis of various additional lightning properties derived from OTD/LIS, i.e. the number of so-called "events" and "groups" per flash, as well as 10 the mean flash duration, footprint and radiance. These normalized quantities, which can be associated with the flash "strength", show consistent spatial patterns; most strikingly, oceanic flashes show higher values than continental flashes for all properties. Over land, regions with high (Eastern US) 15 and low (India) flash strength can be clearly identified. We discuss possible causes and implications of the observed regional differences. Although a direct quantitative interpretation of the investigated flash properties is difficult, the observed spatial patterns provide valuable information for the 20 interpretation and application of climatological flash rates. Due to the systematic regional variations of physical flash characteristics, viewing conditions, and/or measurement sensitivities, parametrisations of lightning NOx based on total flash rate densities alone are probably affected by regional biases.

  6. Dune field pattern formation and recent transporting winds in the Olympia Undae Dune Field, north polar region of Mars

    OpenAIRE

    Ewing, Ryan C.; Peyret, Aymeric-Pierre B.; Kocurek, Gary; Bourke, Mary

    2010-01-01

    High-Resolution Imaging Science Experiment (HiRISE) imagery of the central Olympia Undae Dune Field in the north polar region of Mars shows a reticulate dune pattern consisting of two sets of nearly orthogonal dune crestlines, with apparent slipfaces on the primary crests, ubiquitous wind ripples, areas of coarse-grained wind ripples, and deflated interdune areas. Geomorphic evidence and dune field pattern analysis of dune crest length, spacing, defect density, and orientation indicates that ...

  7. Simulating price patterns for tradable green certificates to promote electricity generation from wind

    International Nuclear Information System (INIS)

    Ford, Andrew; Vogstad, Klaus; Flynn, Hilary

    2007-01-01

    This article uses computer simulation to anticipate the price dynamics in a market for Tradable Green Certificates (TGCs). These markets have been used in Europe to promote generation of electricity from renewable resources like wind. Similar markets have been proposed in the United States of America (USA) where the certificates are called Renewable Energy Credits (RECs). The certificates are issued to the generating companies for each megawatt-hour of renewable electricity generation. The companies may sell the certificates in a market, and the revenues from certificate sales provide an extra incentive to invest in new generating capacity. Proponents argue that this market-based incentive can be designed to support government mandates for a growing fraction of electricity generation from renewable sources. In the USA, these mandates are set by the states and are known as Renewable Portfolio Standards (RPS). We simulate the price dynamics of a market designed to support an aggressive mandate for wind generation in the northwestern USA. The simulations show that the certificate price climbs rapidly to the cap in the early years after the market opens. Investors then react to these high prices with construction of new wind capacity. After a few years, wind generation meets, and then exceeds the requirement. We show that this pattern appears again and again when the simulations are repeated with wide variations in the estimates of behavioral parameters. We use the model to study the impact of different trading strategies by the wind companies and by the distribution companies. We also study the simulated market response if the USA adopts the carbon allowance market envisioned in The Climate Stewardship Act. The article concludes with recommendations for policy makers involved in TGC market design

  8. Wind-related orientation patterns in diurnal, crepuscular and nocturnal high-altitude insect migrants

    Directory of Open Access Journals (Sweden)

    Gao eHu

    2016-02-01

    Full Text Available Most insect migrants fly at considerable altitudes (hundreds of meters above the ground where they utilize fast-flowing winds to achieve rapid and comparatively long-distance transport. The nocturnal aerial migrant fauna has been well studied with entomological radars, and many studies have demonstrated that flight orientations are frequently grouped around a common direction in a range of nocturnal insect migrants. Common orientation typically occurs close to the downwind direction (thus ensuring that a large component of the insects’ self-powered speed is directed downstream, and in nocturnal insects at least, the downwind headings are seemingly maintained by direct detection of wind-related turbulent cues. Despite being far more abundant and speciose, the day-flying windborne migrant fauna has been much less studied by radar; thus the frequency of wind-related common orientation patterns and the sensory mechanisms involved in their formation remain to be established. Here we analyze a large dataset of >600,000 radar-detected ‘medium-sized’ windborne insect migrants (body mass from 10 to 70 mg, flying hundreds of meters above southern UK, during the afternoon, in the period around sunset, and in the middle of the night. We found that wind-related common orientation was almost ubiquitous during the day (present in 97% of all ‘migration events’ analyzed, and was also frequent at sunset (85% and at night (81%. Headings were systematically offset to the right of the flow at night-time (as predicted from the use of turbulence cues for flow assessment, but there was no directional bias in the offsets during the day or at sunset. Orientation ‘performance’ significantly increased with increasing flight altitude throughout the day and night. We conclude by discussing sensory mechanisms which most likely play a role in the selection and maintenance of wind-related flight headings.

  9. Simulating price patterns for tradable green certificates to promote electricity generation from wind

    International Nuclear Information System (INIS)

    Ford, A.

    2007-01-01

    This article uses computer simulation to anticipate the price dynamics in a market for Tradable Green Certificates (TGCs). These markets have been used in Europe to promote generation of electricity from renewable resources like wind. Similar markets have been proposed in the United States of America (USA) where the certificates are called Renewable Energy Credits (RECs). The certificates are issued to the generating companies for each megawatt-hour of renewable electricity generation. The companies may sell the certificates in a market, and the revenues from certificate sales provide an extra incentive to invest in new generating capacity. Proponents argue that this market-based incentive can be designed to support government mandates for a growing fraction of electricity generation from renewable sources. In the USA, these mandates are set by the states and are known as Renewable Portfolio Standards (RPS). We simulate the price dynamics of a market designed to support an aggressive mandate for wind generation in the northwestern USA. The simulations show that the certificate price climbs rapidly to the cap in the early years after the market opens. Investors then react to these high prices with construction of new wind capacity. After a few years, wind generation meets, and then exceeds the requirement. We show that this pattern appears again and again when the simulations are repeated with wide variations in the estimates of behavioral parameters. We use the model to study the impact of different trading strategies by the wind companies and by the distribution companies. We also study the simulated market response if the USA adopts the carbon allowance market envisioned in The Climate Stewardship Act. The article concludes with recommendations for policy makers involved in TGC market design. [Author

  10. The effect of vegetation patterns on Aeolian mass flux at regional scale: a wind tunnel study

    OpenAIRE

    Youssef, Feras; Visser, Saskia M; Karssenberg, Derek; Erpul, Gunay; Cornelis, Wim; Gabriels, Donald; Poortinga, Ate; De Boever, Maarten

    2012-01-01

    ABSTRACT Although insight on the effect of vegetation pattern on Aeolian mass transport is essential for re-planting degraded land, only limited knowledge on this effect is available. The objective of this research was to understand the effect of vegetation design on the Aeolian mass flux inside a single land unit and at the borders among land units. A simulation of Atriplex halimus shrubs inside a wind tunnel was made, and sand redistribution was measured after the application of 200-230 sec...

  11. Solar-wind predictions for the Parker Solar Probe orbit. Near-Sun extrapolations derived from an empirical solar-wind model based on Helios and OMNI observations

    Science.gov (United States)

    Venzmer, M. S.; Bothmer, V.

    2018-03-01

    Context. The Parker Solar Probe (PSP; formerly Solar Probe Plus) mission will be humanitys first in situ exploration of the solar corona with closest perihelia at 9.86 solar radii (R⊙) distance to the Sun. It will help answer hitherto unresolved questions on the heating of the solar corona and the source and acceleration of the solar wind and solar energetic particles. The scope of this study is to model the solar-wind environment for PSPs unprecedented distances in its prime mission phase during the years 2018 to 2025. The study is performed within the Coronagraphic German And US SolarProbePlus Survey (CGAUSS) which is the German contribution to the PSP mission as part of the Wide-field Imager for Solar PRobe. Aim. We present an empirical solar-wind model for the inner heliosphere which is derived from OMNI and Helios data. The German-US space probes Helios 1 and Helios 2 flew in the 1970s and observed solar wind in the ecliptic within heliocentric distances of 0.29 au to 0.98 au. The OMNI database consists of multi-spacecraft intercalibrated in situ data obtained near 1 au over more than five solar cycles. The international sunspot number (SSN) and its predictions are used to derive dependencies of the major solar-wind parameters on solar activity and to forecast their properties for the PSP mission. Methods: The frequency distributions for the solar-wind key parameters, magnetic field strength, proton velocity, density, and temperature, are represented by lognormal functions. In addition, we consider the velocity distributions bi-componental shape, consisting of a slower and a faster part. Functional relations to solar activity are compiled with use of the OMNI data by correlating and fitting the frequency distributions with the SSN. Further, based on the combined data set from both Helios probes, the parameters frequency distributions are fitted with respect to solar distance to obtain power law dependencies. Thus an empirical solar-wind model for the inner

  12. Geosat altimeter derived sea surface wind speeds and significant wave heights for the north Indian Ocean and their comparison with in situ data

    Digital Repository Service at National Institute of Oceanography (India)

    Vethamony, P.; Vaithiyanathan, R.; Almeida, A.M.; Santanam, K.; Rao, L.V.G.; Sarkar, A.; Kumar, R.; Gairola, R.M.; Gohil, B.S.

    coded maps, showing the distribution of mean monthly values of wind and wave parameters over 2.5 degrees square grids. Altimeter derived wind and wave parameters are compared with (1) winds and waves obtained through ships of opportunity and documented...

  13. Local and regional effects of large scale atmospheric circulation patterns on winter wind power output in Western Europe

    Science.gov (United States)

    Zubiate, Laura; McDermott, Frank; Sweeney, Conor; O'Malley, Mark

    2014-05-01

    Recent studies (Brayshaw, 2009, Garcia-Bustamante, 2010, Garcia-Bustamante, 2013) have drawn attention to the sensitivity of wind speed distributions and likely wind energy power output in Western Europe to changes in low-frequency, large scale atmospheric circulation patterns such as the North Atlantic Oscillation (NAO). Wind speed variations and directional shifts as a function of the NAO state can be larger or smaller depending on the North Atlantic region that is considered. Wind speeds in Ireland and the UK for example are approximately 20 % higher during NAO + phases, and up to 30 % lower during NAO - phases relative to the long-term (30 year) climatological means. By contrast, in southern Europe, wind speeds are 15 % lower than average during NAO + phases and 15 % higher than average during NAO - phases. Crucially however, some regions such as Brittany in N.W. France have been identified in which there is negligible variability in wind speeds as a function of the NAO phase, as observed in the ERA-Interim 0.5 degree gridded reanalysis database. However, the magnitude of these effects on wind conditions is temporally and spatially non-stationary. As described by Comas-Bru and McDermott (2013) for temperature and precipitation, such non-stationarity is caused by the influence of two other patterns, the East Atlantic pattern, (EA), and the Scandinavian pattern, (SCA), which modulate the position of the NAO dipole. This phenomenon has also implications for wind speeds and directions, which has been assessed using the ERA-Interim reanalysis dataset and the indices obtained from the PC analysis of sea level pressure over the Atlantic region. In order to study the implications for power production, the interaction of the NAO and the other teleconnection patterns with local topography was also analysed, as well as how these interactions ultimately translate into wind power output. The objective is to have a better defined relationship between wind speed and power

  14. Comparison of Speed-Up Over Hills Derived from Wind-Tunnel Experiments, Wind-Loading Standards, and Numerical Modelling

    Science.gov (United States)

    Safaei Pirooz, Amir A.; Flay, Richard G. J.

    2018-03-01

    We evaluate the accuracy of the speed-up provided in several wind-loading standards by comparison with wind-tunnel measurements and numerical predictions, which are carried out at a nominal scale of 1:500 and full-scale, respectively. Airflow over two- and three-dimensional bell-shaped hills is numerically modelled using the Reynolds-averaged Navier-Stokes method with a pressure-driven atmospheric boundary layer and three different turbulence models. Investigated in detail are the effects of grid size on the speed-up and flow separation, as well as the resulting uncertainties in the numerical simulations. Good agreement is obtained between the numerical prediction of speed-up, as well as the wake region size and location, with that according to large-eddy simulations and the wind-tunnel results. The numerical results demonstrate the ability to predict the airflow over a hill with good accuracy with considerably less computational time than for large-eddy simulation. Numerical simulations for a three-dimensional hill show that the speed-up and the wake region decrease significantly when compared with the flow over two-dimensional hills due to the secondary flow around three-dimensional hills. Different hill slopes and shapes are simulated numerically to investigate the effect of hill profile on the speed-up. In comparison with more peaked hill crests, flat-topped hills have a lower speed-up at the crest up to heights of about half the hill height, for which none of the standards gives entirely satisfactory values of speed-up. Overall, the latest versions of the National Building Code of Canada and the Australian and New Zealand Standard give the best predictions of wind speed over isolated hills.

  15. Tornado Damage Assessment: Reconstructing the Wind Through Debris Tracking and Treefall Pattern Analysis

    Science.gov (United States)

    Godfrey, C. M.; Peterson, C. J.; Lombardo, F.

    2017-12-01

    Efforts to enhance the resilience of communities to tornadoes requires an understanding of the interconnected nature of debris and damage propagation in both the built and natural environment. A first step toward characterizing the interconnectedness of these elements within a given community involves detailed post-event surveys of tornado damage. Such damage surveys immediately followed the 22 January 2017 EF3 tornadoes in the southern Georgia towns of Nashville and Albany. After assigning EF-scale ratings to impacted structures, the authors geotagged hundreds of pieces of debris scattered around selected residential structures and outbuildings in each neighborhood and paired each piece of debris with its source structure. Detailed information on trees in the vicinity of the structures supplements the debris data, including the species, dimensions, location, fall direction, and level of damage. High-resolution satellite imagery helps to identify the location and fall direction of hundreds of additional forest trees. These debris and treefall patterns allow an estimation of the near-surface wind field using a Rankine vortex model coupled with both a tree stability model and an infrastructure fragility model that simulates debris flight. Comparisons between the modeled damage and the actual treefall and debris field show remarkable similarities for a selected set of vortex parameters, indicating the viability of this approach for estimating enhanced Fujita scale levels, determining the near-surface wind field of a tornado during its passage through a neighborhood, and identifying how debris may contribute to the overall risk from tornadoes.

  16. A Pattern Recognition Approach to Acoustic Emission Data Originating from Fatigue of Wind Turbine Blades.

    Science.gov (United States)

    Tang, Jialin; Soua, Slim; Mares, Cristinel; Gan, Tat-Hean

    2017-11-01

    The identification of particular types of damage in wind turbine blades using acoustic emission (AE) techniques is a significant emerging field. In this work, a 45.7-m turbine blade was subjected to flap-wise fatigue loading for 21 days, during which AE was measured by internally mounted piezoelectric sensors. This paper focuses on using unsupervised pattern recognition methods to characterize different AE activities corresponding to different fracture mechanisms. A sequential feature selection method based on a k-means clustering algorithm is used to achieve a fine classification accuracy. The visualization of clusters in peak frequency-frequency centroid features is used to correlate the clustering results with failure modes. The positions of these clusters in time domain features, average frequency-MARSE, and average frequency-peak amplitude are also presented in this paper (where MARSE represents the Measured Area under Rectified Signal Envelope). The results show that these parameters are representative for the classification of the failure modes.

  17. Patterns of Swahili Verbal Derivatives: An Analysis of their Formation

    African Journals Online (AJOL)

    A verbal root is the irreducible element of a verb or the primitive radical without prefix, suffix or other inflexion. In a Swahili verbal derivational process, suffixes are inserted between the root and the final vowel. Swahili grammarians categorize productive formative verbal suffixes into applied or prepositional suffix, stative or ...

  18. Wind reduction patterns around isolated biomass for wind erosion control in a desertified area of Central Sudan

    NARCIS (Netherlands)

    Nasr Al-amin, N.K.; Stigter, C.J.; El-Tayeb Mohammed, A.

    2010-01-01

    The aim of this study was to assess the effectiveness of sparse vegetation, feature common in arid zone, to reduce wind force (velocity) and hence protect the surface and regions downwind from drifting sand and their consequences. Respectively 4 (with heights h of 4, 3.2, 2 and 1.66 m), 2 (with h of

  19. Wind Effects on Flow Patterns and Net Fluxes in Density-Driven High-Latitude Channel Flow

    Science.gov (United States)

    Huntley, Helga S.; Ryan, Patricia

    2018-01-01

    A semianalytic two-dimensional model is used to analyze the interplay between the different forces acting on density-driven flow in high-latitude channels. In particular, the balance between wind stress, viscous forces, baroclinicity, and sea surface slope adjustments under specified flux conditions is examined. Weak winds are found not to change flow patterns appreciably, with minimal (change the flow significantly, especially at the surface, by either strengthening the dual-jet pattern, established without wind, by a factor of 2-3 or initiating return flow at the surface. A nonzero flux does not result in the addition of a uniform velocity throughout the channel cross section, but modifies both along-channel and cross-channel velocities to become more symmetric, dominated by a down-channel jet centered in the domain and counter-clockwise lateral flow. We also consider formulations of the model that allow adjustments of the net flux in response to the wind. Flow patterns change, beyond uniform intensification or weakening, only for strong winds and high Ekman number. Comparisons of the model results to observational data collected in Nares Strait in the Canadian Archipelago in the summer of 2007 show rough agreement, but the model misses the upstream surface jet on the east side of the strait and propagates bathymetric effects too strongly in the vertical for this moderately high eddy viscosity. Nonetheless, the broad strokes of the observed high-latitude flow are reproduced.

  20. Comparison of different statistical modelling approaches for deriving spatial air temperature patterns in an urban environment

    Science.gov (United States)

    Straub, Annette; Beck, Christoph; Breitner, Susanne; Cyrys, Josef; Geruschkat, Uta; Jacobeit, Jucundus; Kühlbach, Benjamin; Kusch, Thomas; Richter, Katja; Schneider, Alexandra; Umminger, Robin; Wolf, Kathrin

    2017-04-01

    Frequently spatial variations of air temperature of considerable magnitude occur within urban areas. They correspond to varying land use/land cover characteristics and vary with season, time of day and synoptic conditions. These temperature differences have an impact on human health and comfort directly by inducing thermal stress as well as indirectly by means of affecting air quality. Therefore, knowledge of the spatial patterns of air temperature in cities and the factors causing them is of great importance, e.g. for urban planners. A multitude of studies have shown statistical modelling to be a suitable tool for generating spatial air temperature patterns. This contribution presents a comparison of different statistical modelling approaches for deriving spatial air temperature patterns in the urban environment of Augsburg, Southern Germany. In Augsburg there exists a measurement network for air temperature and humidity currently comprising 48 stations in the city and its rural surroundings (corporately operated by the Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health and the Institute of Geography, University of Augsburg). Using different datasets for land surface characteristics (Open Street Map, Urban Atlas) area percentages of different types of land cover were calculated for quadratic buffer zones of different size (25, 50, 100, 250, 500 m) around the stations as well for source regions of advective air flow and used as predictors together with additional variables such as sky view factor, ground level and distance from the city centre. Multiple Linear Regression and Random Forest models for different situations taking into account season, time of day and weather condition were applied utilizing selected subsets of these predictors in order to model spatial distributions of mean hourly and daily air temperature deviations from a rural reference station. Furthermore, the different model setups were

  1. Wind speed pattern in Nigeria (a case study of some coastal and ...

    African Journals Online (AJOL)

    In this study, wind speeds were analysed using the daily wind data obtained from Nigeria Meteorological Agency, Oshodi Lagos at the height of 10m at the different stations during the period of 2000-2010. Weibull , lognormal and normal probability density functions were employed. It was found that the daily mean wind ...

  2. A simple model of the wind turbine induction zone derived from numerical simulations

    DEFF Research Database (Denmark)

    Troldborg, Niels; Meyer Forsting, Alexander Raul

    2017-01-01

    The induction zone in front of different wind turbine rotors is studied by means of steady-state Navier-Stokes simulations combined with an actuator disk approach. It is shown that, for distances beyond 1 rotor radius upstream of the rotors, the induced velocity is self-similar and independent of...... of the rotor geometry. On the basis of these findings, a simple analytical model of the induction zone of wind turbines is proposed....

  3. Case study of visualizing global user download patterns using Google Earth and NASA World Wind

    Energy Technology Data Exchange (ETDEWEB)

    Zong, Ziliang; Job, Joshua; Zhang, Xuesong; Nijim, Mais; Qin, Xiao

    2012-10-09

    Geo-visualization is significantly changing the way we view spatial data and discover information. On the one hand, a large number of spatial data are generated every day. On the other hand, these data are not well utilized due to the lack of free and easily used data-visualization tools. This becomes even worse when most of the spatial data remains in the form of plain text such as log files. This paper describes a way of visualizing massive plain-text spatial data at no cost by utilizing Google Earth and NASAWorld Wind. We illustrate our methods by visualizing over 170,000 global download requests for satellite images maintained by the Earth Resources Observation and Science (EROS) Center of U.S. Geological Survey (USGS). Our visualization results identify the most popular satellite images around the world and discover the global user download patterns. The benefits of this research are: 1. assisting in improving the satellite image downloading services provided by USGS, and 2. providing a proxy for analyzing the hot spot areas of research. Most importantly, our methods demonstrate an easy way to geovisualize massive textual spatial data, which is highly applicable to mining spatially referenced data and information on a wide variety of research domains (e.g., hydrology, agriculture, atmospheric science, natural hazard, and global climate change).

  4. Physically-based modeling of topographic effects on spatial evapotranspiration and soil moisture patterns through radiation and wind

    Directory of Open Access Journals (Sweden)

    M. Liu

    2012-02-01

    Full Text Available In this paper, simulations with the Soil Water Atmosphere Plant (SWAP model are performed to quantify the spatial variability of both potential and actual evapotranspiration (ET, and soil moisture content (SMC caused by topography-induced spatial wind and radiation differences. To obtain the spatially distributed ET/SMC patterns, the field scale SWAP model is applied in a distributed way for both pointwise and catchment wide simulations. An adapted radiation model from r.sun and the physically-based meso-scale wind model METRAS PC are applied to obtain the spatial radiation and wind patterns respectively, which show significant spatial variation and correlation with aspect and elevation respectively. Such topographic dependences and spatial variations further propagate to ET/SMC. A strong spatial, seasonal-dependent, scale-relevant intra-catchment variability in daily/annual ET and less variability in SMC can be observed from the numerical experiments. The study concludes that topography has a significant effect on ET/SMC in the humid region where ET is a energy limited rather than water availability limited process. It affects the spatial runoff generation through spatial radiation and wind, therefore should be applied to inform hydrological model development. In addition, the methodology used in the study can serve as a general method for physically-based ET estimation for data sparse regions.

  5. Analytical derivation of traffic patterns in cache-coherent shared-memory systems

    DEFF Research Database (Denmark)

    Stuart, Matthias Bo; Sparsø, Jens

    2011-01-01

    This paper presents an analytical method to derive the worst-case traffic pattern caused by a task graph mapped to a cache-coherent shared-memory system. Our analysis allows designers to rapidly evaluate the impact of different mappings of tasks to IP cores on the traffic pattern. The accuracy...... varies with the application’s data sharing pattern, and is around 65% in the average case and 1% in the best case when considering the traffic pattern as a whole. For individual connections, our method produces tight worst-case bandwidths....

  6. Glyphosate and AMPA distribution in wind-eroded sediment derived from loess soil

    NARCIS (Netherlands)

    Martins Bento, Celia; Goossens, Dirk; Rezaei, Mahrooz; Riksen, M.J.P.M.; Mol, J.G.J.; Ritsema, C.J.; Geissen, V.

    2017-01-01

    Glyphosate is one of the most used herbicides in agricultural lands worldwide. Wind-eroded sediment and dust, as an environmental transport pathway of glyphosate and of its main metabolite aminomethylphosphonic acid (AMPA), can result in environmental- and human exposure far beyond the agricultural

  7. Directional short wind wave spectra derived from the sea surface photography

    Science.gov (United States)

    Dulov, Vladimir; Yurovskaya, Maria; Chapron, Bertrand; Kudryavtsev, Vladimir

    2014-05-01

    New field measurements of 2-D wave number short wind wave spectra in the wavelength range from few millimeters to few decimeters are reported and discussed. The measurement method proposed by [Kosnik and Dulov, 2011] is based on stereophotography and image brightness contrast processing. The method strongly builds on the brightness cross-spectral analysis to reduce the noise within this short wave gravity and capillary range. Field measurements of wind wave spectra are still rare, and the reported data thus provide valuable information to bring new evidences on the 2-D spectral distribution of short wind waves in the wavelength range from decimeters to millimeters. As found, the folded spectra of decimeter waves are very weakly dependent on the wind speed and its direction. Wind speed and direction sensitivity only starts to appear in the short wavelength range, more precisely in the vicinity of the wave number 100 rad/m, where the wind exponent grows from 0.5 to 1.5-2.5 at 800 rad/m, and angular anisotropy parameter introduced by [Elfouhaily et al., 1997] amounts the value of 0.5. These aspects are consistent with other previously reported optical and radar data. For the latter, we solely extracted the polarization sensitivity to best isolate the contribution associated to the wave saturation spectrum around the Bragg resonant wave number. For the former, mean-squared slope statistics were used to assess the integrated shortscale directional spectral properties. As revealed, observed direction spectral distributions are significantly different from those previously suggested [Elfouhaily et al., 1997; Kudryavtsev et al., 2003, 2005]. On the basis of these new in situ measurements, we then propose to revise the semiempirical analytical model of short wind wave spectra developed by [Kudryavtsev et al., 2003, 2005]. In this model the key parameter is exponent n governing the nonlinear dissipation rate as D ~ Bn+1, where B is saturation spectrum. Accordingly, new

  8. Near-surface wind pattern in regional climate projections over the broader Adriatic region

    Science.gov (United States)

    Belušić, Andreina; Telišman Prtenjak, Maja; Güttler, Ivan; Ban, Nikolina; Leutwyler, David; Schär, Christoph

    2017-04-01

    The Adriatic region is characterized by the complex coastline, strong topographic gradients and specific wind regimes. This represents excellent test area for the latest generation of the regional climate models (RCMs) applied over the European domain. The most famous wind along the Adriatic coast is bora, which due to its strength, has a strong impact on all types of human activities in the Adriatic region. The typical bora wind is a severe gusty downslope flow perpendicular to the mountains. Besides bora, in the Adriatic region, typical winds are sirocco (mostly during the wintertime) and sea/land breezes (dominantly in the warm part of the year) as a part of the regional Mediterranean wind system. Thus, it is substantial to determine future changes in the wind filed characteristics (e.g., changes in strength and frequencies). The first step was the evaluation of a suite of ten EURO- and MED-CORDEX models (at 50 km and 12.5 km resolution), and two additional high resolution models from the Swiss Federal Institute of Technology in Zürich (ETHZ, at 12.5 km and 2.2. km resolution) in the present climate. These results provided a basis for the next step where wind field features, in an ensemble of RCMs forced by global climate models (GCMs) in historical and future runs are examined. Our aim is to determine the influence of the particular combination of RCMs and GCMs, horizontal resolution and emission scenario on the future changes in the near-surface wind field. The analysis reveals strong sensitivity of the simulated wind flow and its statistics to both season and location analyzed, to the horizontal resolution of the RCM and on the choice of the particular GCM that provides boundary conditions.

  9. Severe wind gust thresholds for Meteoalarm derived from uniform return periods in ECA&D

    Directory of Open Access Journals (Sweden)

    A. Stepek

    2012-06-01

    Full Text Available In this study we present an alternative wind gust warning guideline for Meteoalarm, the severe weather warning website for Europe. There are unrealistically large differences in levels and issuing frequencies of all warning levels currently in use between neighbouring Meteoalarm countries. This study provides a guide for the Meteoalarm community to review their wind gust warning thresholds. A more uniform warning system is achieved by using one pan-European return period per warning level. The associated return values will be different throughout Europe because they depend on local climate conditions, but they will not change abruptly at country borders as is currently the case for the thresholds. As return values are a measure of the possible danger of an event and its impact on society, they form an ideal basis for a warning system. Validated wind gust measurements from the European Climate Assessment and Dataset (ECA&D, http://www.ecad.eu were used to calculate return values of the annual maximum wind gust. The current thresholds are compared with return values for 3 different return periods: 10 times a year return periods for yellow warnings, 2 yr periods for orange and 5 yr periods for red warnings. So far 10 countries provide wind gust data to ECA&D. Due to the ECA&D completeness requirements and the fact that some countries provided too few stations to be representative for that country, medians of the return values of annual maximum wind gust could be calculated for 6 of the 10 countries. Alternative guideline thresholds are presented for Norway, Ireland, The Netherlands, Germany, the Czech Republic and Spain and the need to distinguish between coastal, inland and mountainous regions is demonstrated. The new thresholds based on uniform return periods differ significantly from the current ones, particularly for coastal and mountainous areas.

    We are aware of other, sometimes binding

  10. Weibull Wind-Speed Distribution Parameters Derived from a Combination of Wind-Lidar and Tall-Mast Measurements Over Land, Coastal and Marine Sites

    DEFF Research Database (Denmark)

    Gryning, Sven-Erik; Floors, Rogier Ralph; Peña, Alfredo

    2016-01-01

    Wind-speed observations from tall towers are used in combination with observations up to 600 m in altitude from a Doppler wind lidar to study the long-term conditions over suburban (Hamburg), rural coastal (Høvsøre) and marine (FINO3) sites. The variability in the wind field among the sites is ex...

  11. Pattern recognition methods and air pollution source identification. [based on wind direction

    Science.gov (United States)

    Leibecki, H. F.; King, R. B.

    1978-01-01

    Directional air samplers, used for resolving suspended particulate matter on the basis of time and wind direction were used to assess the feasibility of characterizing and identifying emission source types in urban multisource environments. Filters were evaluated for 16 elements and X-ray fluorescence methods yielded elemental concentrations for direction, day, and the interaction of direction and day. Large numbers of samples are necessary to compensate for large day-to-day variations caused by wind perturbations and/or source changes.

  12. Prediction of Wind Environment and Indoor/Outdoor Relationships for PM2.5 in Different Building–Tree Grouping Patterns

    Directory of Open Access Journals (Sweden)

    Bo Hong

    2018-01-01

    Full Text Available Airflow behavior and indoor/outdoor PM2.5 dispersion in different building–tree grouping patterns depend significantly on the building–tree layouts and orientation towards the prevailing wind. By using a standard k-ε model and a revised generalized drift flux model, this study evaluated airflow fields and indoor/outdoor relationships for PM2.5 resulting from partly wind-induced natural ventilation in four hypothetical building–tree grouping patterns. Results showed that: (1 Patterns provide a variety of natural ventilation potential that relies on the wind influence, and buildings that deflect wind on the windward facade and separate airflow on the leeward facade have better ventilation potential; (2 Patterns where buildings and trees form a central space and a windward opening side towards the prevailing wind offer the best ventilation conditions; (3 Under the assumption that transported pollution sources are diluted through the inlet, the aerodynamics and deposition effects of trees cause the lower floors of a multi-storey building to be exposed to lower PM2.5 compared with upper floors, and lower indoor PM2.5 values were found close to the tree canopy; (4 Wind pressure differences across each flat showed a poor correlation (R2 = 0.059, with indoor PM2.5 concentrations; and (5 Patterns with the long facade of buildings and trees perpendicular to the prevailing wind have the lowest indoor PM2.5 concentrations.

  13. Extreme Fire Severity Patterns in Topographic, Convective and Wind-Driven Historical Wildfires of Mediterranean Pine Forests

    Science.gov (United States)

    Lecina-Diaz, Judit; Alvarez, Albert; Retana, Javier

    2014-01-01

    Crown fires associated with extreme fire severity are extremely difficult to control. We have assessed fire severity using differenced Normalized Burn Ratio (dNBR) from Landsat imagery in 15 historical wildfires of Pinus halepensis Mill. We have considered a wide range of innovative topographic, fuel and fire behavior variables with the purposes of (1) determining the variables that influence fire severity patterns among fires (considering the 15 wildfires together) and (2) ascertaining whether different variables affect extreme fire severity within the three fire types (topographic, convective and wind-driven fires). The among-fires analysis showed that fires in less arid climates and with steeper slopes had more extreme severity. In less arid conditions there was more crown fuel accumulation and closer forest structures, promoting high vertical and horizontal fuel continuity and extreme fire severity. The analyses carried out for each fire separately (within fires) showed more extreme fire severity in areas in northern aspects, with steeper slopes, with high crown biomass and in climates with more water availability. In northern aspects solar radiation was lower and fuels had less water limitation to growth which, combined with steeper slopes, produced more extreme severity. In topographic fires there was more extreme severity in northern aspects with steeper slopes and in areas with more water availability and high crown biomass; in convection-dominated fires there was also more extreme fire severity in northern aspects with high biomass; while in wind-driven fires there was only a slight interaction between biomass and water availability. This latter pattern could be related to the fact that wind-driven fires spread with high wind speed, which could have minimized the effect of other variables. In the future, and as a consequence of climate change, new zones with high crown biomass accumulated in non-common drought areas will be available to burn as extreme

  14. Extreme fire severity patterns in topographic, convective and wind-driven historical wildfires of Mediterranean pine forests.

    Science.gov (United States)

    Lecina-Diaz, Judit; Alvarez, Albert; Retana, Javier

    2014-01-01

    Crown fires associated with extreme fire severity are extremely difficult to control. We have assessed fire severity using differenced Normalized Burn Ratio (dNBR) from Landsat imagery in 15 historical wildfires of Pinus halepensis Mill. We have considered a wide range of innovative topographic, fuel and fire behavior variables with the purposes of (1) determining the variables that influence fire severity patterns among fires (considering the 15 wildfires together) and (2) ascertaining whether different variables affect extreme fire severity within the three fire types (topographic, convective and wind-driven fires). The among-fires analysis showed that fires in less arid climates and with steeper slopes had more extreme severity. In less arid conditions there was more crown fuel accumulation and closer forest structures, promoting high vertical and horizontal fuel continuity and extreme fire severity. The analyses carried out for each fire separately (within fires) showed more extreme fire severity in areas in northern aspects, with steeper slopes, with high crown biomass and in climates with more water availability. In northern aspects solar radiation was lower and fuels had less water limitation to growth which, combined with steeper slopes, produced more extreme severity. In topographic fires there was more extreme severity in northern aspects with steeper slopes and in areas with more water availability and high crown biomass; in convection-dominated fires there was also more extreme fire severity in northern aspects with high biomass; while in wind-driven fires there was only a slight interaction between biomass and water availability. This latter pattern could be related to the fact that wind-driven fires spread with high wind speed, which could have minimized the effect of other variables. In the future, and as a consequence of climate change, new zones with high crown biomass accumulated in non-common drought areas will be available to burn as extreme

  15. Seasonal patterns of wind-induced upwelling/downwelling in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Andrew Bakun

    2001-09-01

    Full Text Available The historical file of wind observations from maritime weather reports is summarized to identify the characteristic seasonal distributions of wind-induced Ekman upwelling and downwelling in the Mediterranean Sea. Both coastal upwelling/downwelling and wind-stress curl-driven open ocean upwelling/downwelling are treated in a unified description. Vigorous upwelling zones are found in the eastern Aegean Sea, off the west coast of Greece, and in the Gulf of Lyons. The southern coast of the Mediterranean is found to be primarily a downwelling area, although significant coastal upwelling does appear in the Gulf of Sidra during the spring and summer seasons, and along the Algerian coast during summer.

  16. Mass detection, localization and estimation for wind turbine blades based on statistical pattern recognition

    DEFF Research Database (Denmark)

    Colone, L.; Hovgaard, K.; Glavind, Lars

    2018-01-01

    A method for mass change detection on wind turbine blades using natural frequencies is presented. The approach is based on two statistical tests. The first test decides if there is a significant mass change and the second test is a statistical group classification based on Linear Discriminant...... Analysis. The frequencies are identified by means of Operational Modal Analysis using natural excitation. Based on the assumption of Gaussianity of the frequencies, a multi-class statistical model is developed by combining finite element model sensitivities in 10 classes of change location on the blade......, the smallest area being 1/5 of the span. The method is experimentally validated for a full scale wind turbine blade in a test setup and loaded by natural wind. Mass change from natural causes was imitated with sand bags and the algorithm was observed to perform well with an experimental detection rate of 1...

  17. Empirically derived dietary patterns and health-related quality of life in the SUN project.

    Directory of Open Access Journals (Sweden)

    Cristina Ruano

    Full Text Available The analysis of dietary patterns has become a valuable tool to examine diet-disease relationships but little is known about their effects on quality of life. Our aim was to ascertain the association between major dietary patterns and mental and physical quality of life after 4 years of follow-up.This analysis included 11,128 participants from the "Seguimiento Universidad de Navarra" (SUN cohort. Dietary habits were assessed using a validated food-frequency questionnaire. Factor analysis was used to derive dietary patterns. Quality of life was measured with the validated Spanish version of the SF-36 Health Survey.Two major dietary patterns were identified, the 'Western' dietary pattern (rich in red meats, processed pastries and fast-food and the "Mediterranean" dietary pattern (high in fruits, vegetables and olive oil. After controlling for confounders, the Western dietary pattern was associated with quality of life in all domains. The magnitude of these differences between the subjects in the highest (quintile 5 and the lowest quintile of adherence to the Western pattern ranged from -0.8 (for mental health to -3.5 (for vitality. On the contrary, the Mediterranean dietary pattern was associated with better quality of life domains: differences ranged from +1.3 (for physical functioning to +3.4 (for vitality when comparing extreme quintiles of adherence. Additional sensitivity analyses did not change the reported differences.Whereas baseline adherence to a Western dietary pattern was inversely associated with self-perceived quality of life after 4 years of follow-up, baseline adherence to a Mediterranean dietary pattern was directly associated with better scores in quality of life four years later in the SUN Project.

  18. Temporal and spatial variability of wind resources in the United States as derived from the Climate Forecast System Reanalysis

    Science.gov (United States)

    Lejiang Yu; Shiyuan Zhong; Xindi Bian; Warren E. Heilman

    2015-01-01

    This study examines the spatial and temporal variability of wind speed at 80m above ground (the average hub height of most modern wind turbines) in the contiguous United States using Climate Forecast System Reanalysis (CFSR) data from 1979 to 2011. The mean 80-m wind exhibits strong seasonality and large spatial variability, with higher (lower) wind speeds in the...

  19. NORSEWIND – Mesoscale model derived Wind Atlases for the Irish Sea, the North Sea and the Baltic Sea

    DEFF Research Database (Denmark)

    Berge, Erik; Hasager, Charlotte Bay; Bredesen, Rolv Erlend

    Offshore Wind Atlases based on the meso-scale model WRF are presented and validated in this paper. The Work has been part of the EU-funded project NORSEWIND (Northern Seas Wind Index Database). Validations show that annual average wind speeds and wind-roses at hub-height (100m) are well represented...

  20. Wind Speed Pattern in Nigeria (A Case Study of Some Coastal and ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Department of Physics and Solar Energy, Bowen University Iwo, Osun State, Nigeria. Email: joeademola @gmail. ... source. (Ajayi,2009;Ajayi et al,2009). One way through this is to develop the available renewable energy resources of which wind energy technology is a major. ... Udoakah and Ikafia, 2017). Further study by ...

  1. Load-Direction-Derived Support Structures for Wind Turbines: A Lattice Tower Concept and Preparations for Future Certifications: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Jonkman, Jason [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Damiani, Rick R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Struve, Achim [University of Applied Sciences Flensburg; Faber, Torsten [University of Applied Sciences Flensburg; Ummenhofer, Thomas [Karlsruhe Institute of Technology

    2017-11-07

    The call for more cost-effective and environmentally friendly tower concepts is motivated by tower costs [1] and tower CO2-emission contributions [2], which are high relative to the whole wind turbine system. The proposed rotatable tower concept with yaw bearing at the bottom instead of the top of the tower will provide beneficial economic and environmental impacts to the turbine system. This wind alignment capability indicates a load-direction-derived tower design. By combining this approach with a lattice concept, large material and cost savings for the tower can be achieved. This paper presents a way to analyze and verify the proposed design through aero-servo-elastic simulations, which make future certifications of rotatable tower concepts viable. For this reason, the state-of-the-art, open-source lattice-tower finite-element-method (FEM) module SubDyn [10], developed by the National Renewable Energy Laboratory, has been modified to account for arbitrary member cross-sections. Required changes in the beam element stiffness and mass matrix formulation took place according to an energy method [13]. All validated adaptions will be usable within the aero-servo-elastic simulation framework FAST and are also beneficial for other nonrotatable lattice structures.

  2. Surface Wind Fields in the Vicinity of Meso-Convective Storms as Derived from Radar Observations: Non-Tornadic Storms.

    Science.gov (United States)

    1986-12-01

    comparisons. FIELD 1 FIELD 2 PROCEDURE SAM Winds Winds from TWIND COMPLOT SAM Winds Modified DRWF MODPLOT (DW from TWIND) DRWF SAM Radial Winds... COMPLOT DRWF Radial Winds COMPLOT from TWIND 1,v 35 Part Two The method used to accomplish the second part of this research objective was to compare the...earlier researchers. Table 2.4 provided the comparisons and the procedure used for each comparison. Two computer programs, composite plot ( COMPLOT ) and

  3. A modelling framework to predict bat activity patterns on wind farms: An outline of possible applications on mountain ridges of North Portugal.

    Science.gov (United States)

    Silva, Carmen; Cabral, João Alexandre; Hughes, Samantha Jane; Santos, Mário

    2017-03-01

    Worldwide ecological impact assessments of wind farms have gathered relevant information on bat activity patterns. Since conventional bat study methods require intensive field work, the prediction of bat activity might prove useful by anticipating activity patterns and estimating attractiveness concomitant with the wind farm location. A novel framework was developed, based on the stochastic dynamic methodology (StDM) principles, to predict bat activity on mountain ridges with wind farms. We illustrate the framework application using regional data from North Portugal by merging information from several environmental monitoring programmes associated with diverse wind energy facilities that enable integrating the multifactorial influences of meteorological conditions, land cover and geographical variables on bat activity patterns. Output from this innovative methodology can anticipate episodes of exceptional bat activity, which, if correlated with collision probability, can be used to guide wind farm management strategy such as halting wind turbines during hazardous periods. If properly calibrated with regional gradients of environmental variables from mountain ridges with windfarms, the proposed methodology can be used as a complementary tool in environmental impact assessments and ecological monitoring, using predicted bat activity to assist decision making concerning the future location of wind farms and the implementation of effective mitigation measures. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Photo-induced morphological winding and unwinding motion of nanoscrolls composed of niobate nanosheets with a polyfluoroalkyl azobenzene derivative

    Science.gov (United States)

    Nabetani, Yu; Takamura, Hazuki; Uchikoshi, Akino; Hassan, Syed Zahid; Shimada, Tetsuya; Takagi, Shinsuke; Tachibana, Hiroshi; Masui, Dai; Tong, Zhiwei; Inoue, Haruo

    2016-06-01

    Photo-responsive nanoscrolls can be successfully fabricated by mixing a polyfluoroalkyl azobenzene derivative and a niobate nanosheet, which is exfoliated from potassium hexaniobate. In this study, we have found that the photo-responsive nanoscroll shows a morphological motion of winding and unwinding, which is basically due to the nanosheet sliding within the nanoscroll, by efficient photo-isomerization reactions of the intercalated azobenzene in addition to the interlayer distance change of the nanoscrolls. The relative nanosheet sliding of the nanoscroll is estimated to be ca. 280 nm from the AFM morphology analysis. The distance of the sliding motion is over 20 times that of the averaged nanosheet sliding in the azobenzene/niobate hybrid film reported previously. Photo-responsive nanoscrolls can be expected to be novel photo-activated actuators and artificial muscle model materials.Photo-responsive nanoscrolls can be successfully fabricated by mixing a polyfluoroalkyl azobenzene derivative and a niobate nanosheet, which is exfoliated from potassium hexaniobate. In this study, we have found that the photo-responsive nanoscroll shows a morphological motion of winding and unwinding, which is basically due to the nanosheet sliding within the nanoscroll, by efficient photo-isomerization reactions of the intercalated azobenzene in addition to the interlayer distance change of the nanoscrolls. The relative nanosheet sliding of the nanoscroll is estimated to be ca. 280 nm from the AFM morphology analysis. The distance of the sliding motion is over 20 times that of the averaged nanosheet sliding in the azobenzene/niobate hybrid film reported previously. Photo-responsive nanoscrolls can be expected to be novel photo-activated actuators and artificial muscle model materials. Electronic supplementary information (ESI) available: Fig. S1. Photo-isomerization reaction of nanoscrolls. See DOI: 10.1039/c6nr02177h

  5. Pre-conceptual-schema-based patterns for deriving key performance indicators from strategic objectives

    Directory of Open Access Journals (Sweden)

    Carlos Mario Zapata Jaramillo

    2017-05-01

    Full Text Available Performance measurement is crucial for achieving business success. Moreover, such success is also related to the fulfillment of the organizational strategic objectives. Hence, an adequate determination of relevant performance indicators—or key performance indicators (KPIs—and their relationships to organizational objectives is needed. Even though several approaches for treating KPIs and objective-KPI relationships have been proposed, they exhibit some drawbacks associated with the lack of reusability and traceability. We attempt to fill this gap by proposing a set of patterns based on pre-conceptual schemas for supporting the systematic derivation of KPIs and their relationships to organizational objectives. In this way, the proposed patterns guarantee a reusable and traceable derivation process of a set of candidate KPIs from organizational strategic objectives. Lastly, we provide a lab study in order to illustrate the usefulness of this proposal.

  6. Intraseasonal patterns in coastal plankton biomass off central Chile derived from satellite observations and a biochemical model

    Science.gov (United States)

    Gomez, Fabian A.; Spitz, Yvette H.; Batchelder, Harold P.; Correa-Ramirez, Marco A.

    2017-10-01

    Subseasonal (5-130 days) environmental variability can strongly affect plankton dynamics, but is often overlooked in marine ecology studies. We documented the main subseasonal patterns of plankton biomass in the coastal upwelling system off central Chile, the southern part of the Humboldt System. Subseasonal variability was extracted from temporal patterns in satellite data of wind stress, sea surface temperature, and chlorophyll from the period 2003-2011, and from a realistically forced eddy-resolving physical-biochemical model from 2003 to 2008. Although most of the wind variability occurs at submonthly frequencies (anchovy. The wind-driven variability of chlorophyll concentration was connected to mid- and high-latitude atmospheric anomalies, which resemble disturbances with frequencies similar to the tropical Madden-Julian Oscillation.

  7. A Posteriori-Derived Dietary Patterns and Retinal Vessel Caliber in an Elderly Population

    OpenAIRE

    McEvoy, CT; Cardwell, CR; Chakravarthy, U; Hogg, RE; McKinley, MC; Young, IS; Fletcher, AE; Woodside, JV

    2013-01-01

    PURPOSE. To examine the association between a posteriori-derived dietary patterns (DP) and retinal vessel caliber in an elderly population. METHODS. This was a cross-sectional study of 288 elderly adults (>65 years) who participated in the European Eye study (EUREYE) Northern Irish cohort. DP were extracted using principal component analysis from completed food frequency questionnaires. Semi-automated computer grading was used to determine the mean retinal vessel diameters (central retinal ar...

  8. Diet index-based and empirically derived dietary patterns are associated with colorectal cancer risk.

    Science.gov (United States)

    Miller, Paige E; Lazarus, Philip; Lesko, Samuel M; Muscat, Joshua E; Harper, Gregory; Cross, Amanda J; Sinha, Rashmi; Ryczak, Karen; Escobar, Gladys; Mauger, David T; Hartman, Terryl J

    2010-07-01

    Previous studies have derived patterns by measuring compliance with preestablished dietary guidance or empirical methods, such as principal components analysis (PCA). Our objective was to examine colorectal cancer risk associated with patterns identified by both methods. The study included 431 incident colorectal cancer cases (225 men, 206 women) and 726 healthy controls (330 men, 396 women) participating in a population-based, case-control study. PCA identified sex-specific dietary patterns and the Healthy Eating Index-2005 (HEI-05) assessed adherence to the 2005 Dietary Guidelines for Americans. A fruits and vegetables pattern and a meat, potatoes, and refined grains pattern were identified among men and women; a third pattern (alcohol and sweetened beverages) was identified in men. The fruits and vegetables pattern was inversely associated with risk among men [odds ratio (OR) = 0.38, 95% CI = 0.21-0.69 for the highest compared with the lowest quartile] and women (OR = 0.35, 95% CI = 0.19-0.65). The meat, potatoes, and refined grains pattern was positively associated with risk in women (OR = 2.20, 95% CI = 1.08-4.50) and there was a suggestion of a positive association among men (OR = 1.56, 95% CI = 0.84-2.90; P-trend = 0.070). Men and women with greater HEI-05 scores had a significantly reduced risk of colorectal cancer (OR = 0.56, 95% CI = 0.31-0.99; OR = 0.44, 95% CI = 0.24-0.77, respectively). Following the Dietary Guidelines or a dietary pattern lower in meat, potatoes, high fat, and refined foods and higher in fruits and vegetables may reduce colorectal cancer risk.

  9. Seabird aggregative patterns: a new tool for offshore wind energy risk assessment.

    Science.gov (United States)

    Christel, Isadora; Certain, Grégoire; Cama, Albert; Vieites, David R; Ferrer, Xavier

    2013-01-15

    The emerging development of offshore wind energy has raised public concern over its impact on seabird communities. There is a need for an adequate methodology to determine its potential impacts on seabirds. Environmental Impact Assessments (EIAs) are mostly relying on a succession of plain density maps without integrated interpretation of seabird spatio-temporal variability. Using Taylor's power law coupled with mixed effect models, the spatio-temporal variability of species' distributions can be synthesized in a measure of the aggregation levels of individuals over time and space. Applying the method to a seabird aerial survey in the Ebro Delta, NW Mediterranean Sea, we were able to make an explicit distinction between transitional and feeding areas to define and map the potential impacts of an offshore wind farm project. We use the Ebro Delta study case to discuss the advantages of potential impacts maps over density maps, as well as to illustrate how these potential impact maps can be applied to inform on concern levels, optimal EIA design and monitoring in the assessment of local offshore wind energy projects. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. A posteriori-derived dietary patterns and retinal vessel caliber in an elderly population.

    Science.gov (United States)

    McEvoy, Claire T; Cardwell, Christopher R; Chakravarthy, Usha; Hogg, Ruth E; McKinley, Michelle C; Young, Ian S; Fletcher, Astrid E; Woodside, Jayne V

    2013-02-15

    To examine the association between a posteriori-derived dietary patterns (DP) and retinal vessel caliber in an elderly population. This was a cross-sectional study of 288 elderly adults (>65 years) who participated in the European Eye study (EUREYE) Northern Irish cohort. DP were extracted using principal component analysis from completed food frequency questionnaires. Semi-automated computer grading was used to determine the mean retinal vessel diameters (central retinal arteriole equivalent [CRAE] and central retinal venule equivalent [CRVE]) from digitized visual field one images using a standard measurement protocol. THREE MAJOR DP WERE IDENTIFIED IN THIS POPULATION, WHICH ACCOUNTED FOR 21% OF THE TOTAL VARIANCE: a "healthy" pattern with high factor loadings for oily fish, fruits and vegetables, and olive oil; an "unhealthy" pattern with high factor loadings for red and processed meat, refined grains, eggs, butter, sugar and sweets; and a "snack and beverage" pattern with high factor loading for pizza, nuts, and coffee. Multivariable linear regression analysis indicated no significant association between major identified DP and mean CRAE or CRVE in all models. This is the first study to investigate associations between a posteriori-derived DP and retinal vessel caliber. There was no evidence of a relationship between extracted DP and retinal vessel measurements in this population. However, it is possible that potentially important relationships exist between single nutrients or foods and vessel diameters that cannot be identified using a DP approach. Further studies to examine the role of dietary factors in the microcirculation are required.

  11. Pattern of liquid crystalline droplets induced by two beam interference in azobenzene derivative

    Science.gov (United States)

    Czajkowski, Maciej; Dradrach, Klaudia; Bartkiewicz, Stanislaw; Galewski, Zbigniew

    2013-10-01

    A pattern of liquid crystalline droplets dispersed in the isotropic liquid can be formed during illumination by two interfering laser beams in certain range of the temperature and the light intensity. Azobenzene derivative substituted by long alkyl and alkoxy chains exhibiting smectic phases has been used for the study. The pattern can be reversibly erased and rewritten by shutting down and opening of the interfering beams. Polarized microscope images have shown the formation of numerous liquid crystalline droplets at bright regions of the interference fringes. Influence of the temperature and the light intensity has been studied by measuring the diffraction efficiency dynamics. Photothermal and photoorientational mechanisms of the formation of liquid crystalline droplets pattern have been proposed and discussed.

  12. Evolution and functional significance of derived sternal ossification patterns in ornithothoracine birds

    Science.gov (United States)

    O’connor, J. K.; Zheng, X.-T.; Sullivan, C.; Chuong, C.-M.; Wang, X.-L.; Li, A.; Wang, Y.; Zhang, X.-M.; Zhou, Z.-H.

    2017-01-01

    The midline pattern of sternal ossification characteristic of the Cretaceous enantiornithine birds is unique among the Ornithodira, the group containing birds, nonavian dinosaurs and pterosaurs. This has been suggested to indicate that Enantiornithes is not the sister group of Ornithuromorpha, the clade that includes living birds and their close relatives, which would imply rampant convergence in many nonsternal features between enantiornithines and ornithuromorphs. However, detailed comparisons reveal greater similarity between neornithine (i.e. crown group bird) and enantiornithine modes of sternal ossification than previously recognized. Furthermore, a new subadult enantiornithine specimen demonstrates that sternal ossification followed a more typically ornithodiran pattern in basal members of the clade. This new specimen, referable to the Pengornithidae, indicates that the unique ossification pattern observed in other juvenile enantiornithines is derived within Enantiornithes. A similar but clearly distinct pattern appears to have evolved in parallel in the ornithuromorph lineage. The atypical mode of sternal ossification in some derived enantiornithines should be regarded as an autapomorphic condition rather than an indication that enantiornithines are not close relatives of ornithuromorphs. Based on what is known about molecular mechanisms for morphogenesis and the possible selective advantages, the parallel shifts to midline ossification that took place in derived enantiornithines and living neognathous birds appear to have been related to the development of a large ventral keel, which is only present in ornithuromorphs and enantiornithines. Midline ossification can serve to medially reinforce the sternum at a relatively early ontogenetic stage, which would have been especially beneficial during the protracted development of the superprecocial Cretaceous enantiornithines. PMID:26079847

  13. Evolution and functional significance of derived sternal ossification patterns in ornithothoracine birds.

    Science.gov (United States)

    O'Connor, J K; Zheng, X-T; Sullivan, C; Chuong, C-M; Wang, X-L; Li, A; Wang, Y; Zhang, X-M; Zhou, Z-H

    2015-08-01

    The midline pattern of sternal ossification characteristic of the Cretaceous enantiornithine birds is unique among the Ornithodira, the group containing birds, nonavian dinosaurs and pterosaurs. This has been suggested to indicate that Enantiornithes is not the sister group of Ornithuromorpha, the clade that includes living birds and their close relatives, which would imply rampant convergence in many nonsternal features between enantiornithines and ornithuromorphs. However, detailed comparisons reveal greater similarity between neornithine (i.e. crown group bird) and enantiornithine modes of sternal ossification than previously recognized. Furthermore, a new subadult enantiornithine specimen demonstrates that sternal ossification followed a more typically ornithodiran pattern in basal members of the clade. This new specimen, referable to the Pengornithidae, indicates that the unique ossification pattern observed in other juvenile enantiornithines is derived within Enantiornithes. A similar but clearly distinct pattern appears to have evolved in parallel in the ornithuromorph lineage. The atypical mode of sternal ossification in some derived enantiornithines should be regarded as an autapomorphic condition rather than an indication that enantiornithines are not close relatives of ornithuromorphs. Based on what is known about molecular mechanisms for morphogenesis and the possible selective advantages, the parallel shifts to midline ossification that took place in derived enantiornithines and living neognathous birds appear to have been related to the development of a large ventral keel, which is only present in ornithuromorphs and enantiornithines. Midline ossification can serve to medially reinforce the sternum at a relatively early ontogenetic stage, which would have been especially beneficial during the protracted development of the superprecocial Cretaceous enantiornithines. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology

  14. Global biogeographical pattern of ecosystem functional types derived from earth observation data

    DEFF Research Database (Denmark)

    Ivits, Eva; Cherlet, Michael; Horion, Stéphanie Marie Anne F

    2013-01-01

    The present study classified global Ecosystem Functional Types (EFTs) derived from seasonal vegetation dynamics of the GIMMS3g NDVI time-series. Rotated Principal Component Analysis (PCA) was run on the derived phenological and productivity variables, which selected the Standing Biomass (approxim......The present study classified global Ecosystem Functional Types (EFTs) derived from seasonal vegetation dynamics of the GIMMS3g NDVI time-series. Rotated Principal Component Analysis (PCA) was run on the derived phenological and productivity variables, which selected the Standing Biomass......% of the variation in global ecosystems. EFTs were created based on Isodata classification of the spatial patterns of the Principal Components and were interpreted via gradient analysis using the selected remote sensing variables and climatic constraints (radiation, temperature, and water) of vegetation growth...... of global ecosystems. Climatic constraints of vegetation growth explained 50% of variation in the phenological data along the EFTs showing that part of the variation in the global phenological gradient is not climate related but is unique to the Earth Observation derived variables. DCA demonstrated good...

  15. A recurrent neural network approach to quantitatively studying solar wind effects on TEC derived from GPS; preliminary results

    Directory of Open Access Journals (Sweden)

    J. B. Habarulema

    2009-05-01

    Full Text Available This paper attempts to describe the search for the parameter(s to represent solar wind effects in Global Positioning System total electron content (GPS TEC modelling using the technique of neural networks (NNs. A study is carried out by including solar wind velocity (Vsw, proton number density (Np and the Bz component of the interplanetary magnetic field (IMF Bz obtained from the Advanced Composition Explorer (ACE satellite as separate inputs to the NN each along with day number of the year (DN, hour (HR, a 4-month running mean of the daily sunspot number (R4 and the running mean of the previous eight 3-hourly magnetic A index values (A8. Hourly GPS TEC values derived from a dual frequency receiver located at Sutherland (32.38° S, 20.81° E, South Africa for 8 years (2000–2007 have been used to train the Elman neural network (ENN and the result has been used to predict TEC variations for a GPS station located at Cape Town (33.95° S, 18.47° E. Quantitative results indicate that each of the parameters considered may have some degree of influence on GPS TEC at certain periods although a decrease in prediction accuracy is also observed for some parameters for different days and seasons. It is also evident that there is still a difficulty in predicting TEC values during disturbed conditions. The improvements and degradation in prediction accuracies are both close to the benchmark values which lends weight to the belief that diurnal, seasonal, solar and magnetic variabilities may be the major determinants of TEC variability.

  16. A recurrent neural network approach to quantitatively studying solar wind effects on TEC derived from GPS; preliminary results

    Directory of Open Access Journals (Sweden)

    J. B. Habarulema

    2009-05-01

    Full Text Available This paper attempts to describe the search for the parameter(s to represent solar wind effects in Global Positioning System total electron content (GPS TEC modelling using the technique of neural networks (NNs. A study is carried out by including solar wind velocity (Vsw, proton number density (Np and the Bz component of the interplanetary magnetic field (IMF Bz obtained from the Advanced Composition Explorer (ACE satellite as separate inputs to the NN each along with day number of the year (DN, hour (HR, a 4-month running mean of the daily sunspot number (R4 and the running mean of the previous eight 3-hourly magnetic A index values (A8. Hourly GPS TEC values derived from a dual frequency receiver located at Sutherland (32.38° S, 20.81° E, South Africa for 8 years (2000–2007 have been used to train the Elman neural network (ENN and the result has been used to predict TEC variations for a GPS station located at Cape Town (33.95° S, 18.47° E. Quantitative results indicate that each of the parameters considered may have some degree of influence on GPS TEC at certain periods although a decrease in prediction accuracy is also observed for some parameters for different days and seasons. It is also evident that there is still a difficulty in predicting TEC values during disturbed conditions. The improvements and degradation in prediction accuracies are both close to the benchmark values which lends weight to the belief that diurnal, seasonal, solar and magnetic variabilities may be the major determinants of TEC variability.

  17. Centennial eolian cyclicity in the Great Plains, USA: A dominant pattern of wind transport over the past 4000 years?

    Science.gov (United States)

    Schwalb, Antje; Dean, Walter E.; Fritz, C. Sherilyn; Geiss, Christoph E.; Kromer, Bernd

    2010-01-01

    Proxy evidence at decadal resolution from Late Holocene sediments from Pickerel Lake, northeastern South Dakota, shows distinct centennial cycles (400-700 years) in magnetic susceptibility; contents of carbonate, organic carbon, and major elements; abundance in ostracodes; and delta18O and delta13C values in calcite. Proxies indicate cyclic changes in eolian input, productivity, and temperature. Maxima in magnetic susceptibility are accompanied by maxima in aluminum and iron mass accumulation rates (MARs), and in abundances of the ostracode Fabaeformiscandona rawsoni. This indicates variable windy, and dry conditions with westerly wind dominance, including during the Medieval Climate Anomaly. Maxima in carbonates, organic carbon, phosphorous, and high delta13C values of endogenic calcite indicate moister and less windy periods with increased lake productivity, including during the Little Ice Age, and alternate with maxima of eolian transport. Times of the Maunder, Sporer and Wolf sunspot minima are characterized by maxima in delta18O values and aluminum MARs, and minima in delta13C values and organic carbon content. We interpret these lake conditions during sunspot minima to indicate decreases in lake surface water temperatures of up to 4-5 degrees C associated with decreases in epilimnetic productivity during summer. We propose that the centennial cycles are triggered by solar activity, originate in the tropical Pacific, and their onset during the Late Holocene is associated with insolation conditions driven by precession. The cyclic pattern is transmitted from the tropical Pacific into the atmosphere and transported by westerly winds into the North Atlantic realm where they strengthen the Atlantic Meridional Overturning Circulation during periods of northern Great Plains wind maxima. This consequently leads to moister climates in Central and Northern Europe. Thus, Pickerel Lake provides evidence for mechanisms of teleconnections including an atmospheric link

  18. Exploring Chemical Space with Alchemical Derivatives: BN-Simultaneous Substitution Patterns in C60.

    Science.gov (United States)

    Balawender, Robert; Lesiuk, Michał; De Proft, Frank; Geerlings, Paul

    2018-02-13

    With the idea of using alchemical derivatives to explore in an efficient, computer- and cost-effective way Chemical Space was launched several years ago. In the context of Conceptual DFT response functions, these energies vs nuclear charge derivatives permit the estimatation of the energy of transmutants of a given starting or reference molecule showing different nuclear compositions. After an explorative study on small and planar molecules ( Balawender et al. J. Chem. Theory Comput. 2013 , 9 , 5327 ) by the present authors of this paper, the present study fully exploits the computational advantages of the alchemical derivatives in larger three-dimensional systems. Starting from a single reference calculation on C 60 , the complete BN substitution pattern, from single substituted C 58 BN via the belt (C 20 (BN) 20 and the ball C 12 (BN) 24 structures to the fully substituted (BN) 30 , is explored. Successive and simultaneous substitution strategies are followed and compared, indicating that both techniques yield identical results up to 13 substitutions but that for higher substitutions the simultaneous approach needs to be taken. Due to the cost-efficiency of the algorithm this path can indeed be followed as opposed to earlier work in the literature where for each step a full SCF calculation was at stake leading to prohibitively large computational demands for adopting the simultaneous approach. Previously formulated rules governing the substitution pattern by Kar and co-workers are scrutinized in this context and reformulated giving chemical insight in the gradual substitution process and the relative energies of the isomers. In its present form the method offers an interesting venue to study BN substitution patterns in higher fullerenes and graphene and in general paves the way for more efficient exploration of the Chemical Space.

  19. Measurement of velocity and velocity derivatives based on pattern tracking in 3D LIF images

    Energy Technology Data Exchange (ETDEWEB)

    Deusch, S.; Merava, H.; Rys, P. [Swiss Federal Inst. of Technol., Zurich (Switzerland). Dept. of Chem. Eng.; Dracos, T. [Swiss Federal Institute of Technology, Untergasse 14, 8126 Zumikon (Switzerland)

    2000-10-01

    Pattern tracking in consecutive 3D LIF images based on least squares matching (LSM) of grey levels has been developed recently for velocity and velocity gradient measurements. The shortcomings of this method are clearly shown. The present article presents an improvement on this method by introducing a local multi-patch (LMP) technique through the LSM approach. The method is validated using the flow field of a turbulent channel flow obtained by direct numerical simulation (DNS) and a synthetic image with grey-level patterns. The results show that LMP matching allows the determination of the velocity and the velocity gradient fields with high accuracy including the second derivatives. Measurements of a round non-buoyant jet are presented which demonstrate the good performance of the method when applied under laboratory conditions. This method can also be applied on two-dimensional images provided that the flow is strictly two-dimensional. (orig.)

  20. Measurement of velocity and velocity derivatives based on pattern tracking in 3D LIF images

    Science.gov (United States)

    Deusch, S.; Merava, H.; Dracos, T.; Rys, P.

    Pattern tracking in consecutive 3D LIF images based on least squares matching (LSM) of grey levels has been developed recently for velocity and velocity gradient measurements. The shortcomings of this method are clearly shown. The present article presents an improvement on this method by introducing a local multi-patch (LMP) technique through the LSM approach. The method is validated using the flow field of a turbulent channel flow obtained by direct numerical simulation (DNS) and a synthetic image with grey-level patterns. The results show that LMP matching allows the determination of the velocity and the velocity gradient fields with high accuracy including the second derivatives. Measurements of a round non-buoyant jet are presented which demonstrate the good performance of the method when applied under laboratory conditions. This method can also be applied on two-dimensional images provided that the flow is strictly two-dimensional.

  1. Derivation of the horizontal wind field in the polar mesopause region by using successive images of noctilucent clouds observed by a color digital camera in Iceland

    Science.gov (United States)

    Suzuki, H.; Yamashita, R.

    2017-12-01

    It is important to quantify amplitude of turbulent motion to understand the energy and momentum budgets and distribution of minor constituents in the upper mesosphere. In particular, to know the eddy diffusion coefficient of minor constituents which are locally and impulsively produced by energetic particle precipitations in the polar mesopause is one of the most important subjects in the upper atmospheric science. One of the straight methods to know the amplitude of the eddy motion is to measure the wind field with both spatial and temporal domain. However, observation technique satisfying such requirements is limited in this region. In this study, derivation of the horizontal wind field in the polar mesopause region by tracking the motion of noctilucent clouds (NLCs) is performed. NLC is the highest cloud in the Earth which appears in a mesopause region during summer season in both polar regions. Since the vertical structure of the NLC is sufficiently thin ( within several hundred meters in typical), the apparent horizontal motion observed from ground can be regarded as the result of transportation by the horizontal winds at a single altitude. In this presentation, initial results of wind field derivation by tracking a motion of noctilucent clouds (NLC) observed by a ground-based color digital camera in Iceland is reported. The procedure for wind field estimation consists with 3 steps; (1) projects raw images to a geographical map (2) enhances NLC structures by using FFT method (3) determines horizontal velocity vectors by applying template matching method to two sequential images. In this talk, a result of the wind derivation by using successive images of NLC with 3 minutes interval and 1.5h duration observed on the night of Aug 1st, 2013 will be reported as a case study.

  2. Analytical Derivation of Traffic Patterns in Shared Memory Architectures from Task Graphs

    DEFF Research Database (Denmark)

    Stuart, Matthias Bo; Sparsø, Jens

    2009-01-01

    Task Graphs is a commonly used application model in research in computer-aided design tools for design space exploration of embedded systems, including system synthesis, scheduling and application mapping. These design tools need an estimate of the actual communication in the target system caused...... by the application modelled by the task graph. In this paper, we present a method for analytically deriving the worst-case traffic pattern when a task graph is mapped to a multiprocessor system-on-chip with a shared memory architecture. We describe the additionally needed information besides the dependencies...

  3. Derivation of a new parametric impulse response matrix utilized for nodal wind load identification by response measurement.

    Science.gov (United States)

    Kazemi Amiri, A; Bucher, C

    2015-05-26

    This paper provides new formulations to derive the impulse response matrix, which is then used in the problem of load identification with application to wind induced vibration. The applied loads are inversely identified based on the measured structural responses by solving the associated discrete ill-posed problem. To this end - based on an existing parametric structural model - the impulse response functions of acceleration, velocity and displacement have been computed. Time discretization of convolution integral has been implemented according to an existing and a newly proposed procedure, which differ in the numerical integration methods. The former was evaluated based on a constant rectangular approximation of the sampled data and impulse response function in a number of steps corresponding to the sampling rate, while the latter interpolates the sampled data in an arbitrary number of sub-steps and then integrates over the sub-steps and steps. The identification procedure was implemented for a simulation example as well as an experimental laboratory case. The ill-conditioning of the impulse response matrix made it necessary to use Tikhonov regularization to recover the applied force from noise polluted measured response. The optimal regularization parameter has been obtained by L-curve and GCV method. The results of simulation represent good agreement between identified and measured force. In the experiments the identification results based on the measured displacement as well as acceleration are provided. Further it is shown that the accuracy of experimentally identified load depends on the sensitivity of measurement instruments over the different frequency ranges.

  4. The effect of vegetation patterns on Aeolian mass flux at regional scale: A wind tunnel study

    NARCIS (Netherlands)

    Youssef, I.F.; Visser, S.M.; Karssenberg, D.; Erpul, G.; Cornelis, W.M.; Gabriels, D.; Poortinga, A.; Boever, de M.

    2012-01-01

    ABSTRACT Although insight on the effect of vegetation pattern on Aeolian mass transport is essential for re-planting degraded land, only limited knowledge on this effect is available. The objective of this research was to understand the effect of vegetation design on the Aeolian mass flux inside a

  5. Ecological coherence of diversity patterns derived from classical fingerprinting and Next Generation Sequencing techniques.

    Science.gov (United States)

    Gobet, Angélique; Boetius, Antje; Ramette, Alban

    2014-09-01

    Changes in richness and bacterial community structure obtained via 454 Massively Parallel Tag Sequencing (MPTS) and Automated Ribosomal Intergenic Analysis (ARISA) were systematically compared to determine whether and how the ecological knowledge obtained from both molecular techniques could be combined. We evaluated community changes over time and depth in marine coastal sands at different levels of taxonomic resolutions, sequence corrections and sequence abundances. Although richness over depth layers or sampling dates greatly varied [∼ 30% and 70-80% new operational taxonomic units (OTU) between two samples with ARISA and MPTS respectively], overall patterns of community variations were similar with both approaches. Alpha-diversity estimated by ARISA-derived OTU was most similar to that obtained from MPTS-derived OTU defined at the order level. Similar patterns of OTU replacement were also found with MPTS at the family level and with 20-25% rare types removed. Using ARISA or MPTS datasets with lower resolution, such as those containing only resident OTU, yielded a similar set of significant contextual variables explaining bacterial community changes. Hence, ARISA as a rapid and low-cost fingerprinting technique represents a valid starting point for more in-depth exploration of community composition when complemented by the detailed taxonomic description offered by MPTS. © 2013 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  6. Comparison of cluster and principal component analysis techniques to derive dietary patterns in Irish adults.

    Science.gov (United States)

    Hearty, Aine P; Gibney, Michael J

    2009-02-01

    The aims of the present study were to examine and compare dietary patterns in adults using cluster and factor analyses and to examine the format of the dietary variables on the pattern solutions (i.e. expressed as grams/day (g/d) of each food group or as the percentage contribution to total energy intake). Food intake data were derived from the North/South Ireland Food Consumption Survey 1997-9, which was a randomised cross-sectional study of 7 d recorded food and nutrient intakes of a representative sample of 1379 Irish adults aged 18-64 years. Cluster analysis was performed using the k-means algorithm and principal component analysis (PCA) was used to extract dietary factors. Food data were reduced to thirty-three food groups. For cluster analysis, the most suitable format of the food-group variable was found to be the percentage contribution to energy intake, which produced six clusters: 'Traditional Irish'; 'Continental'; 'Unhealthy foods'; 'Light-meal foods & low-fat milk'; 'Healthy foods'; 'Wholemeal bread & desserts'. For PCA, food groups in the format of g/d were found to be the most suitable format, and this revealed four dietary patterns: 'Unhealthy foods & high alcohol'; 'Traditional Irish'; 'Healthy foods'; 'Sweet convenience foods & low alcohol'. In summary, cluster and PCA identified similar dietary patterns when presented with the same dataset. However, the two dietary pattern methods required a different format of the food-group variable, and the most appropriate format of the input variable should be considered in future studies.

  7. Substitution pattern elucidation of hydroxypropyl Pinus pinaster (Ait.) bark polyflavonoid derivatives by ESI(-)-MS/MS.

    Science.gov (United States)

    García Marrero, Danny E; Glasser, Wolfgang G; Pizzi, Antonio; Paczkowski, Sebastian; Laborie, Marie-Pierre G

    2014-10-01

    The structure of condensed tannins (CTs) from Pinus pinaster bark extract and their hydroxypropylated derivatives with four degrees of substitution (DS 1, 2, 3 and 4) has been characterized for the first time using negative-ion mode electrospray ionization tandem mass spectrometry (ESI(-)-MS/MS). The results showed that P. pinaster bark CTs possess structural homogeneity in terms of monomeric units (C(15), catechin). The oligomer sizes were detected to be dimers to heptamers. The derivatives showed typical phenyl-propyl ether mass fragmentation by substituent elimination (58 amu) and inherent C(15) flavonoid fissions. The relative abundance of the product ions revealed a preferential triple, tetra-/penta- and octa- hydroxypropylation substitution pattern in the monomer, dimer and trimer derivatives, respectively. A defined order of -OH reactivity towards propylene oxide was established by means of multistage experiments (A-ring ≥ B-ring > C-ring). A high structural heterogeneity of the modified oligomers was detected. Copyright © 2014 John Wiley & Sons, Ltd.

  8. Derivation of Optimal Cropping Pattern in Part of Hirakud Command using Cuckoo Search

    Science.gov (United States)

    Rath, Ashutosh; Biswal, Sudarsan; Samantaray, Sandeep; Swain, Prakash Chandra, PROF.

    2017-08-01

    The economicgrowth of a Nation depends on agriculture which relies on the obtainable water resources, available land and crops. The contribution of water in an appropriate quantity at appropriate time plays avitalrole to increase the agricultural production. Optimal utilization of available resources can be achieved by proper planning and management of water resources projects and adoption of appropriate technology. In the present work, the command area of Sambalpur distribrutary System is taken up for investigation. Further, adoption of a fixed cropping pattern causes the reduction of yield. The present study aims at developing different crop planning strategies to increase the net benefit from the command area with minimum investment. Optimization models are developed for Kharif season using LINDO and Cuckoo Search (CS) algorithm for maximization of the net benefits. In process of development of Optimization model the factors such as cultivable land, seeds, fertilizers, man power, water cost, etc. are taken as constraints. The irrigation water needs of major crops and the total available water through canals in the command of Sambalpur Distributary are estimated. LINDO and Cuckoo Search models are formulated and used to derive the optimal cropping pattern yielding maximum net benefits. The net benefits of Rs.585.0 lakhs in Kharif Season are obtained by adopting LINGO and 596.07 lakhs from Cuckoo Search, respectively, whereas the net benefits of 447.0 lakhs is received by the farmers of the locality with the adopting present cropping pattern.

  9. Methods of suicide: international suicide patterns derived from the WHO mortality database.

    Science.gov (United States)

    Ajdacic-Gross, Vladeta; Weiss, Mitchell G; Ring, Mariann; Hepp, Urs; Bopp, Matthias; Gutzwiller, Felix; Rössler, Wulf

    2008-09-01

    Accurate information about preferred suicide methods is important for devising strategies and programmes for suicide prevention. Our knowledge of the methods used and their variation across countries and world regions is still limited. The aim of this study was to provide the first comprehensive overview of international patterns of suicide methods. Data encoded according to the International Classification of Diseases (10th revision) were derived from the WHO mortality database. The classification was used to differentiate suicide methods. Correspondence analysis was used to identify typical patterns of suicide methods in different countries by providing a summary of cross-tabulated data. Poisoning by pesticide was common in many Asian countries and in Latin America; poisoning by drugs was common in both Nordic countries and the United Kingdom. Hanging was the preferred method of suicide in eastern Europe, as was firearm suicide in the United States and jumping from a high place in cities and urban societies such as Hong Kong Special Administrative Region, China. Correspondence analysis demonstrated a polarization between pesticide suicide and firearm suicide at the expense of traditional methods, such as hanging and jumping from a high place, which lay in between. This analysis showed that pesticide suicide and firearm suicide replaced traditional methods in many countries. The observed suicide pattern depended upon the availability of the methods used, in particular the availability of technical means. The present evidence indicates that restricting access to the means of suicide is more urgent and more technically feasible than ever.

  10. An Evaluation of Accelerometer-derived Metrics to Assess Daily Behavioral Patterns

    Science.gov (United States)

    Keadle, Sarah Kozey; Sampson, Joshua; Li, Haocheng; Lyden, Kate; Matthews, Charles E.; Carroll, Raymond

    2016-01-01

    Introduction The way physical activity (PA) and sedentary behavior (SB) are accumulated throughout the day (i.e., patterns) may be important for health, but identifying measurable and meaningful metrics of behavioral patterns is challenging. This study evaluated accelerometer-derived metrics to determine if they predicted PA and SB patterns and were reliably measured. Methods We defined and measured 55 metrics that describe daily PA and SB using data collected by using the activPal (AP) monitor in four studies. The first two studies were randomized-crossover designs that included recreationally-active participants. Study one experimentally manipulated time spent in moderate-vigorous intensity physical activity (MVPA) and sedentary time and study two held time in exercise constant and manipulated SB. Study three included inactive participants who increased exercise, decreased sedentary time or both. The study conditions induced distinct behavioral patterns, thus we tested whether the new metrics could improve the prediction of an individual’s study condition after adjusting for the overall volume of physical activity or SB using conditional logistic regression. In a fourth study, we measured the three-month reliability for the pattern metrics by calculating intraclass correlations (ICCs) in a community-dwelling sample who wore the AP monitor twice for seven-days. Results In each of the experimental studies, we identified new metrics that could improve the accuracy for predicting condition beyond SB and MVPA volume. In study one, 23 metrics were predictive of a highly active condition and 24 metrics were predictive of a highly sedentary condition in study two. In the fourth study, the median ICC (25–75th percentiles) of the metrics were 0.59 (0.46, 0.65). Conclusions Several new metrics were predictive of patterns of SB, exercise and non-exercise behavior and are moderately reliable over a three-month period. Applying these metrics to determine if daily

  11. Voltage Gain Derivation Based on Energy-Balanced Criterion for a Novel Hybrid-Input PV-Wind Power Conversion System

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2015-01-01

    Full Text Available This paper applies energy-balanced criterion to a novel hybrid-input PV-wind power conversion system (HPWPCS for voltage gain derivation. With the energy-balanced concept, complicated mathematical problems related to voltage gain derivation can be readily resolved. Based on the derived results, it is proven that the proposed HPWPCS is able to process two different kinds of renewable energy resources simultaneously. Even though the HPWPCS includes seven capacitors and three magnetic components, its voltage gain still can be found by the mathematical analysis. In the theoretical derivation, only the energy status of output inductor is dealt with such that complicated derivation procedure is avoided. This analysis method can also be applied to other hybrid green-energy conversion systems. In this paper, a 200 W 50 kHz prototype of HPWPCS is built and examined to verify the mathematical results.

  12. Dietary patterns derived with multiple methods from food diaries and breast cancer risk in the UK Dietary Cohort Consortium.

    NARCIS (Netherlands)

    Pot, G.K.; Stephen, AM; Dahm, C.C.; Key, T.J.; Cairns, B.J.; Burley, V.J.; Cade, J.E.; Greenwood, D.C.; Keogh, R.H.; Bhaniani, A.; McTaggert, A.; Lentjes, M.A.H.; Mishra, G.; Brunner, E.J.; Khaw, K.T.

    2014-01-01

    Background/Objectives:In spite of several studies relating dietary patterns to breast cancer risk, evidence so far remains inconsistent. This study aimed to investigate associations of dietary patterns derived with three different methods with breast cancer risk.Subjects/Methods:The Mediterranean

  13. A Root-Locus Design Methodology Derived from the Impedance/Admittance Stability Formulation and Its Application for LCL Grid-Connected Converters in Wind Turbines

    DEFF Research Database (Denmark)

    Freijedo Fernandez, Francisco Daniel; Diaz, Enrique Rodriguez; Golsorkhi, Mohammad

    2017-01-01

    This paper presents a systematic methodology for design and tuning of the current controller in LCL gridconnected converters for wind turbine applications. The design target is formulated as a minimization of the current loop dominant time constant, which is in accordance with standard design...... guidelines for wind turbine controllers (fast time response and high stability margins). The proposed approach is derived from the impedance/admittance stability formulation, which, on one hand, has been proved to be suitable for controller design when active damping is implemented and, on the other hand......, a sensitivity transfer function is derived, from which the closed-loop eigenvalues can be calculated; finally, the set of control gains that minimize the dominant time constant are obtained by direct search optimization. A case study that models the target system in a low power scale is provided...

  14. Learning to forecast wind at remote sites for wind energy applications. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Notis, C.; Trettel, D.W.; Aquino, J.T.; Piazza, T.R.; Taylor, L.E.; Trask, D.C.; Wegley, H.L.; Miller, A.H.

    1983-01-01

    Observed wind patterns are correlated with synoptic or mescoscale weather systems. Six sites selected for analysis include Montauk Point, New York; Boone, North Carolina; Ludington, Michigan; Clayton, New Mexico; Amarillo, Texas; and San Gorgonio Pass, California. Objectives of the analysis are: to identify synoptic and/or mesoscale weather patterns that are associated with recognizable wind events at the sites; to define a set of criteria that uniquely describes such weather patterns; to estimate the reliability (accuracy) of forecasting rules derived from the association of weather patterns and site winds; and to attempt to separate any mesoscale effects of local topography from the synoptic-scale effects. One-to-one mapping of wind regimes onto synoptic types was not found. It was concluded that four factors should be examined when stratifying wind regimes: synoptic situation, descriptive climatology, pressure gradient vector, and winds aloft. The wind forecasting approach developed was intended for forecasting hourly average winds out to the 24 hour or possibly 36 hour time horizon. (LEW)

  15. NORSEWIND – Mesoscale model derived Wind Atlases for the Irish Sea, the North Sea and the Baltic Sea

    OpenAIRE

    Berge, Erik; Hasager, Charlotte Bay; Bredesen, Rolv Erlend; Hahmann, Andrea N.; Byrkjedal, Oyvind; Pena Diaz, Alfredo; Kravik, Reiar; Harstveit, Knut; Costa, Paolo; Oldroyd, Andy

    2013-01-01

    As a part of the EU Framework 7 R&D Program NORSEWInD, Wind Atlases for the Irish Sea, the North Sea and the Baltic Sea have been developed and made public available. In the present study the development of the offshore Wind Atlases is focused on the use of mesoscale model data since the access to measurements and satellite data have been limited. Mesoscale model runs were carried out for focus areas with high spatial model resolution (2 km) and the entire Wind Atlas domain with coarser r...

  16. A Multi-Modal Face Recognition Method Using Complete Local Derivative Patterns and Depth Maps

    Directory of Open Access Journals (Sweden)

    Shouyi Yin

    2014-10-01

    Full Text Available In this paper, we propose a multi-modal 2D + 3D face recognition method for a smart city application based on a Wireless Sensor Network (WSN and various kinds of sensors. Depth maps are exploited for the 3D face representation. As for feature extraction, we propose a new feature called Complete Local Derivative Pattern (CLDP. It adopts the idea of layering and has four layers. In the whole system, we apply CLDP separately on Gabor features extracted from a 2D image and depth map. Then, we obtain two features: CLDP-Gabor and CLDP-Depth. The two features weighted by the corresponding coefficients are combined together in the decision level to compute the total classification distance. At last, the probe face is assigned the identity with the smallest classification distance. Extensive experiments are conducted on three different databases. The results demonstrate the robustness and superiority of the new approach. The experimental results also prove that the proposed multi-modal 2D + 3D method is superior to other multi-modal ones and CLDP performs better than other Local Binary Pattern (LBP based features.

  17. Impact of Spatial Resolution on Wind Field Derived Estimates of Air Pressure Depression in the Hurricane Eye

    Directory of Open Access Journals (Sweden)

    Linwood Jones

    2010-03-01

    Full Text Available Measurements of the near surface horizontal wind field in a hurricane with spatial resolution of order 1–10 km are possible using airborne microwave radiometer imagers. An assessment is made of the information content of the measured winds as a function of the spatial resolution of the imager. An existing algorithm is used which estimates the maximum surface air pressure depression in the hurricane eye from the maximum wind speed. High resolution numerical model wind fields from Hurricane Frances 2004 are convolved with various HIRAD antenna spatial filters to observe the impact of the antenna design on the central pressure depression in the eye that can be deduced from it.

  18. Contribution to the understanding of how principal component analysis-derived dietary patterns emerge from habitual data on food consumption.

    Science.gov (United States)

    Schwedhelm, Carolina; Iqbal, Khalid; Knüppel, Sven; Schwingshackl, Lukas; Boeing, Heiner

    2018-02-01

    Principal component analysis (PCA) is a widely used exploratory method in epidemiology to derive dietary patterns from habitual diet. Such dietary patterns seem to originate from intakes on multiple days and eating occasions. Therefore, analyzing food intake of study populations with different levels of food consumption can provide additional insights as to how habitual dietary patterns are formed. We analyzed the food intake data of German adults in terms of the relations among food groups from three 24-h dietary recalls (24hDRs) on the habitual, single-day, and main-meal levels, and investigated the contribution of each level to the formation of PCA-derived habitual dietary patterns. Three 24hDRs were collected in 2010-2012 from 816 adults for an European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam subcohort study. We identified PCA-derived habitual dietary patterns and compared cross-sectional food consumption data in terms of correlation (Spearman), consistency (intraclass correlation coefficient), and frequency of consumption across all days and main meals. Contribution to the formation of the dietary patterns was obtained through Spearman correlation of the dietary pattern scores. Among the meals, breakfast appeared to be the most consistent eating occasion within individuals. Dinner showed the strongest correlations with "Prudent" (Spearman correlation = 0.60), "Western" (Spearman correlation = 0.59), and "Traditional" (Spearman correlation = 0.60) dietary patterns identified on the habitual level, and lunch showed the strongest correlations with the "Cereals and legumes" (Spearman correlation = 0.60) habitual dietary pattern. Higher meal consistency was related to lower contributions to the formation of PCA-derived habitual dietary patterns. Absolute amounts of food consumption did not strongly conform to the habitual dietary patterns by meals, suggesting that these patterns are formed by complex combinations of variable food

  19. Probabilistic drought intensification forecasts using temporal patterns of satellite-derived drought indicators

    Science.gov (United States)

    Park, Sumin; Im, Jungho; Park, Seonyeong

    2016-04-01

    A drought occurs when the condition of below-average precipitation in a region continues, resulting in prolonged water deficiency. A drought can last for weeks, months or even years, so can have a great influence on various ecosystems including human society. In order to effectively reduce agricultural and economic damage caused by droughts, drought monitoring and forecasts are crucial. Drought forecast research is typically conducted using in situ observations (or derived indices such as Standardized Precipitation Index (SPI)) and physical models. Recently, satellite remote sensing has been used for short term drought forecasts in combination with physical models. In this research, drought intensification was predicted using satellite-derived drought indices such as Normalized Difference Drought Index (NDDI), Normalized Multi-band Drought Index (NMDI), and Scaled Drought Condition Index (SDCI) generated from Moderate Resolution Imaging Spectroradiometer (MODIS) and Tropical Rainfall Measuring Mission (TRMM) products over the Korean Peninsula. Time series of each drought index at the 8 day interval was investigated to identify drought intensification patterns. Drought condition at the previous time step (i.e., 8 days before) and change in drought conditions between two previous time steps (e.g., between 16 days and 8 days before the time step to forecast) Results show that among three drought indices, SDCI provided the best performance to predict drought intensification compared to NDDI and NMDI through qualitative assessment. When quantitatively compared with SPI, SDCI showed a potential to be used for forecasting short term drought intensification. Finally this research provided a SDCI-based equation to predict short term drought intensification optimized over the Korean Peninsula.

  20. Expression pattern of the human ABC transporters in pluripotent embryonic stem cells and in their derivatives.

    Science.gov (United States)

    Erdei, Zsuzsa; Lőrincz, Réka; Szebényi, Kornélia; Péntek, Adrienn; Varga, Nóra; Likó, István; Várady, György; Szakács, Gergely; Orbán, Tamás I; Sarkadi, Balázs; Apáti, Agota

    2014-09-01

    ATP-binding cassette (ABC) transporters have key roles in various physiological functions as well as providing chemical defense and stress tolerance in human tissues. In this study, we have examined the expression pattern of all ABC proteins in pluripotent human embryonic stem cells (hESCs) and in their differentiated progenies. We paid special attention to the cellular expression and localization of multidrug transporter ABC proteins. Stem cell differentiation was carried out without chemical induction or cell sorting, and specialized cell types were separated mechanically. Cellular features regarding pluripotency and tissue identity, as well as ABC transporter expression were studied by flow cytomtery, immuno-microscopy, and qPCR-based low-density arrays. Pluripotent hESCs and differentiated cell types (cardiomyocytes, neuronal cells, and mesenchymal stem cells) were distinguished by morphology, immunostaining markers, and selected mRNA expression patterns. We found that the mRNA expression levels of the 48 human ABC proteins also clearly distinguished the pluripotent and the respective differentiated cell types. When multidrug and lipid transporter ABC protein expression was examined by using well characterized specific antibodies by flow cytometry and confocal microscopy, the protein expression data corresponded well to the mRNA expression results. Moreover, the cellular localization of these important human ABC transporter proteins could be established in the pluripotent and differentiated hESC derived samples. These studies provide valuable information regarding ABC protein expression in human stem cells and their differentiated offspring. The results may also help to obtain further information concerning the specialized cellular functions of selected ABC transporters. © 2014 Clinical Cytometry Society.

  1. Statistical Patterns of Ionospheric Convection Derived From Mid-Latitude, High-Latitude, and Polar SuperDARN HF Radar Observations

    Science.gov (United States)

    Thomas, E. G.; Shepherd, S. G.

    2017-12-01

    Global patterns of ionospheric convection have been widely studied in terms of the interplanetary magnetic field (IMF) magnitude and orientation in both the Northern and Southern Hemispheres using observations from the Super Dual Auroral Radar Network (SuperDARN). The dynamic range of driving conditions under which existing SuperDARN statistical models are valid is currently limited to periods when the high-latitude convection pattern remains above about 60° geomagnetic latitude. Cousins and Shepherd [2010] found this to correspond to intervals when the solar wind electric field Esw 0) the high-latitude radars often experience difficulties in measuring convection above about 85° geomagnetic latitude. In this presentation, we introduce a new statistical model of ionospheric convection which is valid for much more dominant IMF Bz conditions than was previously possible by including velocity measurements from the newly constructed tiers of radars in the Northern Hemisphere at midlatitudes and in the polar cap. This new model (TS17) is compared to previous statistical models derived from high-latitude SuperDARN observations (RG96, PSR10, CS10) and its impact on instantaneous Map Potential solutions is examined.

  2. The impact of monsoon winds and mesoscale eddies on thermohaline structures and circulation patterns in the northern South China Sea

    Science.gov (United States)

    Zhao, Ruixiang; Zhu, Xiao-Hua; Guo, Xinyu

    2017-07-01

    We deployed 5 pressure-recording inverted echo sounders (PIES) along a section in the northern South China Sea (NSCS), and estimated well the distributions of temperature, salinity and velocity across the section. Applying the empirical orthogonal function (EOF) method, we found that variability of the estimates is dominated by two modes: one named the seasonal mode affecting strongly on the hydrographic distribution with explained variability of temperature/salinity by 62.9/72.2%; the other named the eddy mode, corresponding to the arrival of mesoscale eddies, affecting strongly on the circulation pattern with explained variability of velocity by 63.2%. Temporal variation of the seasonal mode is highly correlated with the monsoon winds southeast of Vietnam, suggesting a nonlocal forcing mechanism. Case studies looking at the structures and evolutions of three captured eddies, whose impacts were well quantified by the eddy mode. The monsoon (eddies) significantly affects temperature, salinity and velocity shallower than 635 m (860 m), 160 m (150 m) and 1055 m (920 m), respectively. The monsoon (eddies) can induce maximum temperature, salinity and velocity anomalies up to -1.6 to 2.1 °C (-2.5 to 2.2 °C), -0.11 to 0.14 psu (-0.13 to 0.27 psu) and -0.31 to 0.46 m/s (-0.40 to 0.38 m/s), respectively. Mean volume transport (VT) across the section is 1.0 Sv (1 Sv= 1 ×106 m3 s-1, positive to the northeast). Seasonal VT (with eddy impacts removed) is -4.6 Sv, 11.4 Sv, -5.1 Sv and -4.1 Sv for spring, summer, autumn and winter, respectively.

  3. NORSEWIND – Mesoscale model derived Wind Atlases for the Irish Sea, the North Sea and the Baltic Sea

    DEFF Research Database (Denmark)

    Berge, Erik; Hasager, Charlotte Bay; Bredesen, Rolv Erlend

    2013-01-01

    estimate a random uncertainty of ±4.0 % and a bias of -6.4 % which is higher than for the average annual wind speed. It is emphasized that the amount of validation data is small and considerable spatial variability of the uncertainty may be expected. For example, near coastal zones model errors could...

  4. Counterintuitive effects of Global Warming-induced wind patterns on primary production in the Northern Humboldt Current System.

    Science.gov (United States)

    Mogollón, Rodrigo; Calil, Paulo H R

    2018-04-14

    It has been hypothesized that global warming will strengthen upwelling-favorable winds in the Northern Humboldt Current System (NHCS) as a consequence of the increase of the land-sea thermal gradient along the Peruvian coast. The effect of strengthened winds in this region is assessed with the use of a coupled physical-biogeochemical model forced with projected and climatological winds. Strengthened winds induce an increase in primary production of 2% per latitudinal degree from 9.5°S to 5°S. In some important coastal upwelling sites primary production is reduced. This is due to a complex balance between nutrient availability, nutrient use efficiency, as well as eddy and wind-driven factors. Mesoscale activity induces a net offshore transport of inorganic nutrients, thus reducing primary production in the coastal upwelling region. Wind mixing, in general disadvantageous for primary producers, leads to shorter residence times in the southern and central coastal zones. Overall, instead of a proportional enhancement in primary production due to increased winds, the NHCS becomes only 5% more productive (+ 5 mol C m -2 yr -1 ), 10% less limited by nutrients and 15% less efficient due to eddy-driven effects. It is found that regions with a initial strong nutrient limitation are more efficient in terms of nutrient assimilation which makes them more resilient in face of the acceleration of the upwelling circulation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  5. Regional Analysis of Long-term Local and Synoptic Effects on Wind Velocity and Energy Patterns in Complex Terrain

    Science.gov (United States)

    Belu, R.; Koracin, D. R.

    2017-12-01

    Investments in renewable energy are justified in both environmental and economic terms. Climate change risks call for mitigation strategies aimed to reduce pollutant emissions, while the energy supply is facing high uncertainty by the current or future global economic and political contexts. Wind energy is playing a strategic role in the efforts of any country for sustainable development and energy supply security. Wind energy is a weather and climate-dependent resource, having a natural spatio-temporal variability at time scales ranging from fraction of seconds to seasons and years, while at spatial scales is strongly affected by the topography and vegetation. Main objective of the study is to investigate spatio-temporal characteristics of the wind velocity in the Southwest U.S., that are relevant to wind energy assessment, analysis, development, operation, and grid integration, by using long-term multiple meteorological tower observations. Wind velocity data and other meteorological parameters from five towers, located near Tonopah, Nevada, operated between 2003 to 2008, and from three towers are located in Carson Valley, Nevada, operated between 2006 and 2014 were used in this study. Multi-annual wind speed data collected did not show significant increase trends with increasing elevation; the differences are mainly governed by the topographic complexity, including local atmospheric circulations. Auto- and cross-correlations show a strong coherence between the wind speed and direction with slowly decreasing amplitude of the multi-day periodicity with increasing lag periods. Besides pronounced diurnal periodicity at all locations, detrended fluctuation analysis also showed significant seasonal and annual periodicities, and long-memory persistence with similar characteristics. In spite of significant differences in mean wind speeds among the towers, due to location specifics, the relatively high auto- and cross-correlation coefficients among the towers indicate

  6. Dietary pattern derived by reduced rank regression and depressive symptoms in a multi-ethnic population: the HELIUS study

    NARCIS (Netherlands)

    Vermeulen, E.; Stronks, K.; Visser, M.; Brouwer, I. A.; Snijder, M. B.; Mocking, R. J. T.; Derks, E. M.; Schene, A. H.; Nicolaou, M.

    2017-01-01

    BACKGROUND/OBJECTIVES: To investigate the association of dietary patterns derived by reduced rank regression (RRR) with depressive symptoms in a multi-ethnic population. SUBJECTS/METHODS: Cross-sectional data from the HELIUS study were used. In total, 4967 men and women (18-70 years) of Dutch,

  7. Qualitative comparison of calculated turbulence responses with wind-tunnel measurements for a DC-10 derivative wing with an active control system

    Science.gov (United States)

    Perry, B., III

    1981-01-01

    Comparisons are presented analytically predicted and experimental turbulence responses of a wind tunnel model of a DC-10 derivative wing equipped with an active control system. The active control system was designed for the purpose of flutter suppression, but it had additional benefit of alleviating gust loads (wing bending moment) by about 25%. Comparisions of various wing responses are presented for variations in active control system parameters and tunnel speed. The analytical turbulence responses were obtained using DYLOFLEX, a computer program for dynamic loads analyses of flexible airplanes with active controls. In general, the analytical predictions agreed reasonably well with the experimental data.

  8. Relationship between Spatio-Temporal Travel Patterns Derived from Smart-Card Data and Local Environmental Characteristics of Seoul, Korea

    Directory of Open Access Journals (Sweden)

    Mi-Kyeong Kim

    2018-03-01

    Full Text Available With the incorporation of an automated fare-collection system into the management of public transportation, not only can the quality of transportation services be improved but also that of the data collected from users when coupled with smart-card technology. The data collected from smart cards provide opportunities for researchers to analyze big data sets and draw meaningful information out of them. This study aims to identify the relationship between travel patterns derived from smart-card data and urban characteristics. Using seven-day transit smart-card data from the public-transportation system in Seoul, the capital city of the Republic of Korea, we investigated the temporal and spatial boarding and alighting patterns of the users. The major travel patterns, classified into five clusters, were identified by utilizing the K-Spectral Centroid clustering method. We found that the temporal pattern of urban mobility reflects daily activities in the urban area and that the spatial pattern of the five clusters classified by travel patterns was closely related to urban structure and urban function; that is, local environmental characteristics extracted from land-use and census data. This study confirmed that the travel patterns at the citywide level can be used to understand the dynamics of the urban population and the urban spatial structure. We believe that this study will provide valuable information about general patterns, which represent the possibility of finding travel patterns from individuals and urban spatial traits.

  9. Ancestral patterning of tergite formation in a centipede suggests derived mode of trunk segmentation in trilobites.

    Directory of Open Access Journals (Sweden)

    Javier Ortega-Hernández

    derived morphogenetic patterning mechanism responsible for the reiterated occurrence of different types of trunk dorsoventral segmental mismatch in several phylogenetically distant, extinct and extant, arthropod groups.

  10. Mobile art pattern wind-force of generation of electricity of prod; Purodo no mobairu atogata furyoku hatsuden

    Energy Technology Data Exchange (ETDEWEB)

    Masuda, Yoriyasu

    1999-03-01

    How to think about usual force of the wind generation of electricity is the generation of electricity facilities where a propeller type is large-scale by the efficiency emphasis. However, as a scale grows bigger, it is understood more that it isn`t necessarily good if usual facilities are popularized when badness of the operating rate that it passes through the noise pollution and the year such as the velocity of the wind 4-5m/s of cut in and so on is taken into consideration. Even if the same force of the wind generation of electricity is said, it does from the beginning of the idea of cooperative plod, and a concept is wrong, and it is the story which must not be compared with a large force of the wind generator. The various functional beauty when that molding fruit stopped to become `the sculpture that wind can be seen` rather rotates is more important in the way of thinking about efficiency priority than to say an abstract expression such as `the love` which can`t have an idea, and `kindness` as sculpture to move by the wind when it says. (NEDO)

  11. Dietary Patterns Derived by Cluster Analysis are Associated with Cognitive Function among Korean Older Adults

    Directory of Open Access Journals (Sweden)

    Jihye Kim

    2015-05-01

    Full Text Available The objective of this study was to investigate major dietary patterns among older Korean adults through cluster analysis and to determine an association between dietary patterns and cognitive function. This is a cross-sectional study. The data from the Korean Multi-Rural Communities Cohort Study was used. Participants included 765 participants aged 60 years and over. A quantitative food frequency questionnaire with 106 items was used to investigate dietary intake. The Korean version of the MMSE-KC (Mini-Mental Status Examination–Korean version was used to assess cognitive function. Two major dietary patterns were identified using K-means cluster analysis. The “MFDF” dietary pattern indicated high consumption of Multigrain rice, Fish, Dairy products, Fruits and fruit juices, while the “WNC” dietary pattern referred to higher intakes of White rice, Noodles, and Coffee. Means of the total MMSE-KC and orientation score of the participants in the MFDF dietary pattern were higher than those of the WNC dietary pattern. Compared with the WNC dietary pattern, the MFDF dietary pattern showed a lower risk of cognitive impairment after adjusting for covariates (OR 0.64, 95% CI 0.44–0.94. The MFDF dietary pattern, with high consumption of multigrain rice, fish, dairy products, and fruits may be related to better cognition among Korean older adults.

  12. Dietary Patterns Derived by Cluster Analysis are Associated with Cognitive Function among Korean Older Adults.

    Science.gov (United States)

    Kim, Jihye; Yu, Areum; Choi, Bo Youl; Nam, Jung Hyun; Kim, Mi Kyung; Oh, Dong Hoon; Yang, Yoon Jung

    2015-05-29

    The objective of this study was to investigate major dietary patterns among older Korean adults through cluster analysis and to determine an association between dietary patterns and cognitive function. This is a cross-sectional study. The data from the Korean Multi-Rural Communities Cohort Study was used. Participants included 765 participants aged 60 years and over. A quantitative food frequency questionnaire with 106 items was used to investigate dietary intake. The Korean version of the MMSE-KC (Mini-Mental Status Examination-Korean version) was used to assess cognitive function. Two major dietary patterns were identified using K-means cluster analysis. The "MFDF" dietary pattern indicated high consumption of Multigrain rice, Fish, Dairy products, Fruits and fruit juices, while the "WNC" dietary pattern referred to higher intakes of White rice, Noodles, and Coffee. Means of the total MMSE-KC and orientation score of the participants in the MFDF dietary pattern were higher than those of the WNC dietary pattern. Compared with the WNC dietary pattern, the MFDF dietary pattern showed a lower risk of cognitive impairment after adjusting for covariates (OR 0.64, 95% CI 0.44-0.94). The MFDF dietary pattern, with high consumption of multigrain rice, fish, dairy products, and fruits may be related to better cognition among Korean older adults.

  13. Association of Empirically Derived Dietary Patterns with Cardiovascular Risk Factors: A Comparison of PCA and RRR Methods.

    Directory of Open Access Journals (Sweden)

    Nicolas Sauvageot

    Full Text Available Principal component analysis is used to determine dietary behaviors of a population whereas reduced rank regression is used to construct disease-related dietary patterns. This study aimed to compare both types of DP and theirs associations with cardiovascular risk factors (CVRF.Data were derived from the cross sectional NESCAV (Nutrition, Environment and Cardiovascular Health study, aiming to describe the cardiovascular health of the Greater region's population (Grand duchy of Luxembourg, Wallonia (Belgium, Lorraine (France. 2298 individuals were included for this study and dietary intake was assessed using a 134-item food frequency questionnaire.We found that CVRF-related patterns also reflect eating behaviours of the population. Comparing concordant food groups between both dietary pattern methods, a diet high in fruits, oleaginous and dried fruits, vegetables, olive oil, fats rich in omega 6 and tea and low in fried foods, lean and fatty meat, processed meat, ready meal, soft drink and beer was associated with lower prevalence of CVRF. In the opposite, a pattern characterized by high intakes of fried foods, meat, offal, beer, wine and aperitifs and spirits, and low intakes of cereals, sugar and sweets and soft drinks was associated with higher prevalence of CVRF.In sum, we found that a "Prudent" and "Animal protein and alcohol" patterns were both associated with CVRF and behaviourally meaningful. Moreover, the relationships of those dietary patterns with lifestyle characteristics support the theory that food choices are part of a larger pattern of healthy lifestyle.

  14. General aspects of meteorology and wind flow patterns at the National Medical Cyclotron site, Camperdown, NSW, Australia

    International Nuclear Information System (INIS)

    Clark, G.H.; Bartsch, F.J.K.

    1994-06-01

    As part of an assessment into the consequences of a potential accident at the National Medical Cyclotron, Camperdown, NSW., Australia, two meteorological stations were installed to monitor the winds, temperatures and atmospheric dispersion conditions. The data will be used to assess environmental impacts of the Cyclotron's operation. In spite of the relatively poor performance of the stations, the wind data indicated significant effects of local buildings and the general urban surface roughness features. The prevailing winds during the study were from the north-north-west at night and south-south-west or north-east sea breezes during the day. Atmospheric stability/dispersion categories were typical of an urban heat island location. 11 refs., 10 tabs, 6 figs

  15. Wind wave source functions in opposing seas

    KAUST Repository

    Langodan, Sabique

    2015-08-26

    The Red Sea is a challenge for wave modeling because of its unique two opposed wave systems, forced by opposite winds and converging at its center. We investigate the different physical aspects of wave evolution and propagation in the convergence zone. The two opposing wave systems have similar amplitude and frequency, each driven by the action of its own wind. Wave patterns at the centre of the Red Sea, as derived from extensive tests and intercomparison between model and measured data, suggest that the currently available wave model source functions may not properly represent the evolution of the local fields that appear to be characterized by a less effective wind input and an enhanced white-capping. We propose and test a possible simple solution to improve the wave-model simulation under opposing winds and waves condition. This article is protected by copyright. All rights reserved.

  16. VG2 NEP PLS DERIVED RDR ION INBOUND S-WIND 48SEC V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set gives the best available values for ion densities, temperatures, and velocities near Neptune derived from data obtained by the Voyager 2 plasma...

  17. Dietary pattern associated with selenoprotein P and MRI-derived body fat volumes, liver signal intensity, and metabolic disorders.

    Science.gov (United States)

    di Giuseppe, Romina; Plachta-Danielzik, Sandra; Koch, Manja; Nöthlings, Ute; Schlesinger, Sabrina; Borggrefe, Jan; Both, Marcus; Müller, Hans-Peter; Kassubek, Jan; Jacobs, Gunnar; Lieb, Wolfgang

    2018-02-14

    The association of complex dietary patterns with circulating selenoprotein P (SELENOP) levels in humans is unknown. In a general population sample, we aimed to identify a dietary pattern explaining inter-individual variation in circulating SELENOP concentrations and to study this pattern in relation to prevalent diabetes, metabolic syndrome (MetS), MRI-determined total volumes of visceral (VAT) and subcutaneous (SAT) abdominal adipose tissue, and liver signal intensity/fatty liver disease. In this cross-sectional study, serum SELENOP levels were measured in 853 individuals. In a subsample of 553 participants, whole-body MRI was performed to assess body fat distribution and liver fat. Dietary intake was assessed by a self-administered food frequency questionnaire and the dietary pattern identified using reduced-rank regression (RRR). Multivariable linear and logistic regressions were used to investigate associations between dietary pattern score and metabolic traits. Characterized by high intake of fruit, vegetables and antioxidant beverages, the RRR-derived dietary pattern displayed inverse associations with VAT, SAT, MetS, and prevalent diabetes in multivariable-adjusted restricted cubic splines. Each unit increase in dietary pattern score was associated with 31% higher SELENOP levels, 12% lower VAT (95% CI: - 19%; - 5%), 13% (95% CI: - 20%; - 6%) lower SAT values and 46% (95% CI: 27%; 60%) and 53% (95% CI: 22%; 72%) lower odds of having MetS or diabetes, respectively. No meaningful relations were observed between the dietary pattern and liver traits. Our observations propose diet-related regulation in SELENOP levels and that the identified dietary pattern is inversely related to VAT, SAT, MetS, and prevalent diabetes.

  18. Patches structure succession based on spatial point pattern features in semi-arid ecosystems of the water-wind erosion crisscross region

    Directory of Open Access Journals (Sweden)

    Hong-Min Hao

    2017-10-01

    Full Text Available Spatial point-pattern analysis can give insights to the underlying processes of patch succession and restoration. It is unclear whether inter-shrub competition determines patch succession. In this paper, we assessed the spatial patterns along patch succession using spatial statistics such as univariate and bivariate O-ring statistics, in the water-wind erosion crisscross region in semi-arid ecosystems of the Loess Plateau. Point pattern analysis results showed that there were no significant difference in three positions of the slope. The small and middle shrub patches were aggregatedly distributed in small spatial scale, meanwhile the large shrub patches were regularly distributed and dead shrub patches were randomly distributed. The small shrub patches were respectively aggregated to the middle and large patches at fine scales. Competition-induced regular distribution or negative relationship becomes obvious when analyzing the shift towards less aggregated perceptible effect of competition, a time component should always be included in spatial pattern-based inference of competition. Our results revealed that regular, clumped and random shrub patch patterns could occur, pending on size of shrub patches, and the shrub patches are distributed in different ways and they can present variant spatial point pattern features along patch size succession.

  19. Patchiness in wind erosion-deposition patterns in response to a recent state change reversal in the Chihuahuan Desert

    Science.gov (United States)

    Shifts from shrub-dominated states to grasslands are believed to be irreversible as a result of positive feedbacks between woody plants and soil properties. In the Chihuahuan Desert, mesquite (Prosopis glandulosa) expansion into black grama (Bouteloua eriopoda) grasslands is maintained by wind redis...

  20. Nutrient-derived dietary patterns and risk of colorectal cancer: a factor analysis in Uruguay.

    Science.gov (United States)

    De Stefani, Eduardo; Ronco, Alvaro L; Boffetta, Paolo; Deneo-Pellegrini, Hugo; Correa, Pelayo; Acosta, Gisele; Mendilaharsu, Maria

    2012-01-01

    In order to explore the role of nutrients and bioactive related substances in colorectal cancer, we conducted a case-control in Uruguay, which is the country with the highest production of beef in the world. Six hundred and eleven (611) cases afflicted with colorectal cancer and 1,362 controls drawn from the same hospitals in the same time period were analyzed through unconditional multiple logistic regression. This base population was submitted to a principal components factor analysis and three factors were retained. They were labeled as the meat-based, plant-based, and carbohydrates patterns. They were rotated using orthogonal varimax method. The highest risk was positively associated with the meat-based pattern (OR for the highest quartile versus the lowest one 1.63, 95 % CI 1.22-2.18, P value for trend = 0.001), whereas the plant-based pattern was strongly protective (OR 0.60, 95 % CI 0.45-0.81, P value for trend pattern was only positively associated with colon cancer risk (OR 1.46, 95 % CI 1.02-2.09). The meat-based pattern was rich in saturated fat, animal protein, cholesterol, and phosphorus, nutrients originated in red meat. Since herocyclic amines are formed in the well-done red meat through the action of amino acids and creatine, it is suggestive that this pattern could be an important etiologic agent for colorectal cancer.

  1. [Playing of wind instruments is associated with an obstructive pattern in the spirometry of adolescents with a good aerobic resistance capacity].

    Science.gov (United States)

    Granell, Javier; Granell, Jose; Ruiz, Diana; Tapias, Jose A

    2011-03-01

    There is controversy in the medical literature regarding the beneficial or detrimental effects of playing wind musical instruments on the respiratory system. The aim of this study is to analyse this relationship, taking the physical condition of the subjects into consideration. Cross-sectional observational study. Public institution with coordinated medium grade musical instruction and primary and secondary education. Young performers (between 13 and 17 years). We collected basic epidemiological parameters (gender, age, weight, size, heath status), and each subject underwent a fitness test ("course navette" cardiorespiratory fitness test) and a forced spirometry. We included 90 students, 53 females and 37 males. Thirty two were wind instrument players and 58 studied other instruments. The two groups were homogeneous with respect to gender, age and body mass index. The maximum oxygen uptake showed no significant difference (P=0.255), further demonstrating an adequate level of fitness compared to the general population. FVC was normal and similar in both groups (P=0.197). The FEV(1) percentage and the FEV(1)/FVC ratio were significantly lower (Pstudy of wind instruments was associated with an obstructive spirometric pattern in young musicians with a normal level of physical fitness. Copyright © 2010 Elsevier España, S.L. All rights reserved.

  2. Combining dispersion modelling with synoptic patterns to understand the wind-borne transport into the UK of the bluetongue disease vector.

    Science.gov (United States)

    Burgin, Laura; Ekström, Marie; Dessai, Suraje

    2017-07-01

    Bluetongue, an economically important animal disease, can be spread over long distances by carriage of insect vectors (Culicoides biting midges) on the wind. The weather conditions which influence the midge's flight are controlled by synoptic scale atmospheric circulations. A method is proposed that links wind-borne dispersion of the insects to synoptic circulation through the use of a dispersion model in combination with principal component analysis (PCA) and cluster analysis. We illustrate how to identify the main synoptic situations present during times of midge incursions into the UK from the European continent. A PCA was conducted on high-pass-filtered mean sea-level pressure data for a domain centred over north-west Europe from 2005 to 2007. A clustering algorithm applied to the PCA scores indicated the data should be divided into five classes for which averages were calculated, providing a classification of the main synoptic types present. Midge incursion events were found to mainly occur in two synoptic categories; 64.8% were associated with a pattern displaying a pressure gradient over the North Atlantic leading to moderate south-westerly flow over the UK and 17.9% of the events occurred when high pressure dominated the region leading to south-easterly or easterly winds. The winds indicated by the pressure maps generally compared well against observations from a surface station and analysis charts. This technique could be used to assess frequency and timings of incursions of virus into new areas on seasonal and decadal timescales, currently not possible with other dispersion or biological modelling methods.

  3. Estimation of phase derivative from a single fringe pattern using Riesz transforms

    Science.gov (United States)

    Tounsi, Yassine; Zada, Sara; Muhire, Desire; Siari, Ahmed; Nassim, Abdelkrim

    2017-11-01

    We propose a technique to estimate the phase derivative in both x and y directions based on Riesz transform from a single speckle correlation fringes. The originality of this technique is to exploit Riesz transform for phase derivatives estimation, spatial modulation, speckle denoising, and measure of features similarity. Phase modulation process is realized by combining a digital spatial carrier and Riesz quadrature; speckle denoising is computed using Riesz wavelets transform, and the performance is evaluated by Riesz features SIMilarity. Before applying our method on real speckle correlation fringes, its performance is tested by numerical simulation.

  4. Wind energy

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses the role wind energy may have in the energy future of the US. The topics discussed in the chapter include historical aspects of wind energy use, the wind energy resource, wind energy technology including intermediate-size and small wind turbines and intermittency of wind power, public attitudes toward wind power, and environmental, siting and land use issues

  5. A Dietary Pattern Derived by Reduced Rank Regression is Associated with Type 2 Diabetes in An Urban Ghanaian Population

    Directory of Open Access Journals (Sweden)

    Laura K. Frank

    2015-07-01

    Full Text Available Reduced rank regression (RRR is an innovative technique to establish dietary patterns related to biochemical risk factors for type 2 diabetes, but has not been applied in sub-Saharan Africa. In a hospital-based case-control study for type 2 diabetes in Kumasi (diabetes cases, 538; controls, 668 dietary intake was assessed by a specific food frequency questionnaire. After random split of our study population, we derived a dietary pattern in the training set using RRR with adiponectin, HDL-cholesterol and triglycerides as responses and 35 food items as predictors. This pattern score was applied to the validation set, and its association with type 2 diabetes was examined by logistic regression. The dietary pattern was characterized by a high consumption of plantain, cassava, and garden egg, and a low intake of rice, juice, vegetable oil, eggs, chocolate drink, sweets, and red meat; the score correlated positively with serum triglycerides and negatively with adiponectin. The multivariate-adjusted odds ratio of type 2 diabetes for the highest quintile compared to the lowest was 4.43 (95% confidence interval: 1.87–10.50, p for trend < 0.001. The identified dietary pattern increases the odds of type 2 diabetes in urban Ghanaians, which is mainly attributed to increased serum triglycerides.

  6. Empirically Derived Dietary Patterns in UK Adults Are Associated with Sociodemographic Characteristics, Lifestyle, and Diet Quality

    Science.gov (United States)

    Cade, Janet; Dawson, Jeremy; Holdsworth, Michelle

    2018-01-01

    The aim of this study was to examine empirical dietary patterns in UK adults and their association with sociodemographic characteristics, lifestyle factors, self-reported nutrient intake, nutrient biomarkers, and the Nutrient-based Diet Quality Score (NDQS) using National Diet and Nutrition Survey data 2008–2012 (n = 2083; mean age 49 years; 43.3% male). Four patterns explained 13.6% of the total variance: ‘Snacks, fast food, fizzy drinks’ (SFFFD), ‘Fruit, vegetables, oily fish’ (FVOF), ‘Meat, potatoes, beer’ (MPB), and ‘Sugary foods, dairy’ (SFD). ‘SFFFD’ was associated positively with: being male; smoking; body mass index (BMI); urinary sodium; intake of non-milk extrinsic sugars (NMES), fat and starch; and negatively with: age; plasma carotenoids; and NDQS. ‘FVOF’ was associated positively with: being non-white; age; income; socioeconomic classification (National Statistics Socio-economic Classifications; NSSEC); plasma carotenoids; intake of non-starch polysaccharides and polyunsaturated fatty acids. It was negatively associated with: being male, smoking, BMI, urinary sodium, intake of saturated fat; and NMES and NDQS. Whilst the patterns explained only 13.6% of the total variance, they were associated with self-reported nutrient intake, biomarkers of nutrient intake, sociodemographic and lifestyle variables, and the NDQS. These findings provide support for dietary patterns analyses as a means of exploring dietary intake in the UK population to inform public health nutrition policy and guidance. PMID:29415478

  7. Empirically Derived Dietary Patterns in UK Adults Are Associated with Sociodemographic Characteristics, Lifestyle, and Diet Quality

    Directory of Open Access Journals (Sweden)

    Katharine Roberts

    2018-02-01

    Full Text Available The aim of this study was to examine empirical dietary patterns in UK adults and their association with sociodemographic characteristics, lifestyle factors, self-reported nutrient intake, nutrient biomarkers, and the Nutrient-based Diet Quality Score (NDQS using National Diet and Nutrition Survey data 2008–2012 (n = 2083; mean age 49 years; 43.3% male. Four patterns explained 13.6% of the total variance: ‘Snacks, fast food, fizzy drinks’ (SFFFD, ‘Fruit, vegetables, oily fish’ (FVOF, ‘Meat, potatoes, beer’ (MPB, and ‘Sugary foods, dairy’ (SFD. ‘SFFFD’ was associated positively with: being male; smoking; body mass index (BMI; urinary sodium; intake of non-milk extrinsic sugars (NMES, fat and starch; and negatively with: age; plasma carotenoids; and NDQS. ‘FVOF’ was associated positively with: being non-white; age; income; socioeconomic classification (National Statistics Socio-economic Classifications; NSSEC; plasma carotenoids; intake of non-starch polysaccharides and polyunsaturated fatty acids. It was negatively associated with: being male, smoking, BMI, urinary sodium, intake of saturated fat; and NMES and NDQS. Whilst the patterns explained only 13.6% of the total variance, they were associated with self-reported nutrient intake, biomarkers of nutrient intake, sociodemographic and lifestyle variables, and the NDQS. These findings provide support for dietary patterns analyses as a means of exploring dietary intake in the UK population to inform public health nutrition policy and guidance.

  8. Biogeographical patterns derived from remote sensing variables: the amphibians and reptiles of the Iberian Peninsula

    NARCIS (Netherlands)

    Sillero, N.; Brito, J.C.; Skidmore, A.K.; Toxopeus, A.G.

    2009-01-01

    The biogeographic patterns in species density of herptiles were analysed in the Iberian Peninsula. Geoclimatic regions were identified using a PCA. Individual habitat suitability (HS) models for 23 amphibians and 35 reptiles at 10 x 10 km scale were calculated with ENFA, using 12 environmental

  9. High-speed Solar Wind Stream Forecast Based on Coronal Hole Index Derived from Solar EUV Images

    Science.gov (United States)

    Gong, J.; Luo, B.; Bu, X.; Liu, S.

    2017-12-01

    High-speed streams (HSS), which originate from coronal holes on the Sun, are interplanetary sources of recurrent geospace environment disturbances such as geomagnetic storms, relativistic electron enhancements at the geosynchronous orbit, and thermosphere density enhancements which increase the orbit decay rate for low orbit satellites. People have been searching for good indices which can be used as proxies of coronal hole to predict HSS. Among these indices, the Pch reported by Luo et al. [2008], reflected both the area and the brightness contributions of coronal hole and showed potential in predicting HSS. In this study, we evaluate the performance of the Pch index in predict the solar wind speed at L1, using Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) images for years 2011 to 2016. On verification of the predicting capability, we focus on the event-based analysis of the predicted arrival times and amplitudes of high-speed streams (considered as HSS events). It is found that the Pch index is capable of predicting the large-scale high-speed stream features about 4 days in advance, with uncertainties in the HSS arrival time of about 1 day and uncertainties in the speed of about 100 km/s.

  10. Wind-tunnel evaluation of NASA developed control laws for flutter suppression on a DC-10 derivative wing

    Science.gov (United States)

    Abel, I.; Newsom, J. R.

    1981-01-01

    Two flutter suppression control laws were synthesized, implemented, and tested on a low speed aeroelastic wing model of a DC-10 derivative. The methodology used to design the control laws is described. Both control laws demonstrated increases in flutter speed in excess of 25 percent above the passive wing flutter speed. The effect of variations in gain and phase on the closed loop performance was measured and compared with analytical predictions. The analytical results are in good agreement with experimental data.

  11. Distinct p53 genomic binding patterns in normal and cancer-derived human cells

    Energy Technology Data Exchange (ETDEWEB)

    Botcheva K.; McCorkle S. R.; McCombie W. R.; Dunn J. J.; Anderson C. W.

    2011-12-15

    We report here genome-wide analysis of the tumor suppressor p53 binding sites in normal human cells. 743 high-confidence ChIP-seq peaks representing putative genomic binding sites were identified in normal IMR90 fibroblasts using a reference chromatin sample. More than 40% were located within 2 kb of a transcription start site (TSS), a distribution similar to that documented for individually studied, functional p53 binding sites and, to date, not observed by previous p53 genome-wide studies. Nearly half of the high-confidence binding sites in the IMR90 cells reside in CpG islands, in marked contrast to sites reported in cancer-derived cells. The distinct genomic features of the IMR90 binding sites do not reflect a distinct preference for specific sequences, since the de novo developed p53 motif based on our study is similar to those reported by genome-wide studies of cancer cells. More likely, the different chromatin landscape in normal, compared with cancer-derived cells, influences p53 binding via modulating availability of the sites. We compared the IMR90 ChIPseq peaks to the recently published IMR90 methylome1 and demonstrated that they are enriched at hypomethylated DNA. Our study represents the first genome-wide, de novo mapping of p53 binding sites in normal human cells and reveals that p53 binding sites reside in distinct genomic landscapes in normal and cancer-derived human cells.

  12. Seasonal Dependence of Geomagnetic Active-Time Northern High-Latitude Upper Thermospheric Winds

    Science.gov (United States)

    Dhadly, Manbharat S.; Emmert, John T.; Drob, Douglas P.; Conde, Mark G.; Doornbos, Eelco; Shepherd, Gordon G.; Makela, Jonathan J.; Wu, Qian; Nieciejewski, Richard J.; Ridley, Aaron J.

    2018-01-01

    This study is focused on improving the poorly understood seasonal dependence of northern high-latitude F region thermospheric winds under active geomagnetic conditions. The gaps in our understanding of the dynamic high-latitude thermosphere are largely due to the sparseness of thermospheric wind measurements. With current observational facilities, it is infeasible to construct a synoptic picture of thermospheric winds, but enough data with wide spatial and temporal coverage have accumulated to construct a meaningful statistical analysis. We use long-term data from eight ground-based and two space-based instruments to derive climatological wind patterns as a function of magnetic local time, magnetic latitude, and season. These diverse data sets possess different geometries and different spatial and solar activity coverage. The major challenge is to combine these disparate data sets into a coherent picture while overcoming the sampling limitations and biases among them. In our previous study (focused on quiet time winds), we found bias in the Gravity Field and Steady State Ocean Circulation Explorer (GOCE) cross-track winds. Here we empirically quantify the GOCE bias and use it as a correction profile for removing apparent bias before empirical wind formulation. The assimilated wind patterns exhibit all major characteristics of high-latitude neutral circulation. The latitudinal extent of duskside circulation expands almost 10∘ from winter to summer. The dawnside circulation subsides from winter to summer. Disturbance winds derived from geomagnetic active and quiet winds show strong seasonal and latitudinal variability. Comparisons between wind patterns derived here and Disturbance Wind Model (DWM07) (which have no seasonal dependence) suggest that DWM07 is skewed toward summertime conditions.

  13. Dietary pattern derived by reduced rank regression and depressive symptoms in a multi-ethnic population: the HELIUS study.

    Science.gov (United States)

    Vermeulen, E; Stronks, K; Visser, M; Brouwer, I A; Snijder, M B; Mocking, R J T; Derks, E M; Schene, A H; Nicolaou, M

    2017-08-01

    To investigate the association of dietary patterns derived by reduced rank regression (RRR) with depressive symptoms in a multi-ethnic population. Cross-sectional data from the HELIUS study were used. In total, 4967 men and women (18-70 years) of Dutch, South-Asian Surinamese, African Surinamese, Turkish and Moroccan origin living in the Netherlands were included. Diet was measured using ethnic-specific food frequency questionnaires. Depressive symptoms were measured with the nine-item patient health questionnaire. By performing RRR in the whole population and per ethnic group, comparable dietary patterns were identified and therefore the dietary pattern for the whole population was used for subsequent analyses. We identified a dietary pattern that was strongly related to eicosapentaenoic acid+docosahexaenoic acid, folate, magnesium and zinc (response variables) and which was characterized by milk products, cheese, whole grains, vegetables, legumes, nuts, potatoes and red meat. After adjustment for confounders, a statistically significant inverse association was observed in the whole population (B: -0.03, 95% CI: -0.06, -0.00, P=0.046) and among Moroccan (B: -0.09, 95% CI: -0.13, -0.04, P=0.027) and South-Asian Surinamese participants (B: -0.05, 95% CI: -0.09, -0.01, P=dietary pattern and significant depressed mood in any of the ethnic groups. No consistent evidence was found that consumption of a dietary pattern, high in nutrients that are hypothesized to protect against depression, was associated with lower depressive symptoms across different ethnic groups.

  14. In-Class Quantification of the Mentos and Diet Coke Analogue Experiment: Effects of Wind on Volcanic Isopach Patterns

    Science.gov (United States)

    Quane, S.; Klos, Z.; Jacobsen, R.

    2009-05-01

    The Mentos and Diet Coke experiment, where instantaneous emplacement of Mentos candy in Diet Coke creates a soda/CO2 eruptive plume, is a common educational analogue for a volcanic eruption. In this paper, we quantify the effects of varying directional wind speeds on the eruptive plume as a learning tool in advanced Introductory Geology and Volcanology courses. The Mentos and Diet Coke reaction is a fun, safe and affordable analogue for explosive, single pulse, basaltic eruptions (e.g., Strombolian eruptions). Specifically, the physical and chemical reaction nucleating CO2 bubbles on the pitted surface of Mentos candy is directly analogous to the collapsing foam eruption regime described by Parfitt (2004) where inertia driven fragmentation of the liquid (Namiki and Manga, 2008) leads to basaltic pyroclastic eruptions. Often, in these systems, the pyroclasts are carried downwind, resulting lopsided (downwind side taller) cinder cones. In our experiments, we create a single pulse eruption by simultaneously dropping four Mentos candies into a 16.9 oz. bottle of Diet Coke. The experiments are run under different wind conditions created by three stacked box fans in the off (control experiment) low, medium and high settings. Wind speed is measured using a hand held anemometer. The pyroclast dispersal is recorded by degree of liquid saturation through four layers of newspaper. The liquid is allowed to soak in for thirty seconds post eruption and then the individual layers of newspaper are separated and the saturation envelope is traced with a black marker and digitally photographed. The pyroclast dispersal envelope (or saturation area) is then quantified from the photos by image analysis in Adobe Photoshop. In addition, the experiments are videotaped to quantify ejection velocity using frame by frame analysis in iMovie. The resulting isopach ("deposit thickness") maps indicate a strong tightening of dispersal envelopes with increasing wind speed as seen in natural

  15. Spatial patterns of primary productivity derived from the Dynamic Habitat Indices predict patterns of species richness and distributions in the tropics

    Science.gov (United States)

    Suttidate, Naparat

    Humans are changing the Earth's ecosystems, which has profound consequences for biodiversity. To understand how species respond to these changes, biodiversity science requires accurate assessments of biodiversity. However, biodiversity assessments are still limited in tropical regions. The Dynamic Habitat Indices (DHIs), derived from satellite data, summarize dynamic patterns of annual primary productivity: (a) cumulative annual productivity, (b) minimum annual productivity, and (c) seasonal variation in productivity. The DHIs have been successfully used in temperate regions, but not yet in the tropics. My goal was to evaluate the importance of primary productivity measured via the DHIs for assessing patterns of species richness and distributions in Thailand. First, I assessed the relationships between the DHIs and tropical bird species richness. I also evaluated the complementarity of the DHIs and topography, climate, latitudinal gradients, habitat heterogeneity, and habitat area in explaining bird species richness. I found that among three DHIs, cumulative annual productivity was the most important factor in explaining bird species richness and that the DHIs outperformed other environmental variables. Second, I developed texture measures derive from DHI cumulative annual productivity, and compared them to habitat composition and fragmentation as predictors of tropical forest bird distributions. I found that adding texture measures to habitat composition and fragmentation models improved the prediction of tropical bird distributions, especially area- and edge-sensitive tropical forest bird species. Third, I predicted the effects of trophic interactions between primary productivity, prey, and predators in relation to habitat connectivity for Indochinese tigers (Panthera tigris). I found that including trophic interactions improved habitat suitability models for tigers. However, tiger habitat is highly fragmented with few dispersal corridors. I also identified

  16. Global patterns of the trends in satellite-derived crop yield proxy, temperature and soil moisture

    Science.gov (United States)

    Sakai, T.; Iizumi, T.; Sakurai, G.; Okada, M.; Nishimori, M.

    2014-12-01

    Crop productivity (yield) is sensitive to climate variability and change. To inform stakeholders, including food agencies in food-importing countries, about future variations in food supply associated with climate variability and change, understanding major climatic drivers of the spatiotemporal variations in crop yield over global cropland during the last few decades is crucial. Although remote sensing has difficulty distinguishing individual crops and misses entire cropping cycles in areas where extensive cloud cover during the monsoon limits satellite observations, it is still useful in deriving a proxy of crop yield over large spatial domain and estimating the impacts on crop yield proxy due to climate, including land-surface temperature and surface-layer soil moisture. This study presents an attempt to globally depict the impact of climate change on crop yield proxy by applying a time series analysis to MODIS and AMSR-E satellite images. The crop yield proxy used was the annual maximum or integrated MODIS-derived NDVI during the growing period predefined on the basis of the global crop calendar. The trends in the crop yield proxy in the interval 2001-2013 appeared positive in higher latitudes and negative in lower latitudes. In higher latitudes (and thus colder regions), the increased land-surface temperature led to an increase in crop yield in part due to the enhanced photosynthesis rate. In contrast, the crop yield proxy showed negative correlation with land-surface temperature in lower latitudes. The increased temperature might decrease crop yield by increasing evapotranspiration rate, plant respiration and/or heat stress. The crop yield proxy was also correlated with the AMSR-E-derived soil moisture, although the geographical distribution of soil moisture was highly heterogeneous.

  17. Construct Validity of Accelerometry-Derived Force to Quantify Basketball Movement Patterns.

    Science.gov (United States)

    Staunton, Craig; Wundersitz, Daniel; Gordon, Brett; Kingsley, Michael

    2017-12-01

    This study assessed the construct validity of accelerometry-derived net force to quantify the external demands of basketball movements. Twenty-eight basketballers completed the Yo-Yo intermittent recovery test (Yo-Yo-IR1) and basketball exercise simulation test (BEST). Intensity was quantified using accelerometry-derived average net force (AvF Net ) and PlayerLoad TM per minute (PL/min). Within-player correlations were determined between intensity and running speed during Yo-Yo-IR1. Measured AvF Net was determined for movements during the BEST and predicted AvF Net was calculated using movement speed and correlations from Yo-Yo-IR1. Relationships between AvF Net and running speed during Yo-Yo-IR1 were nearly perfect (r 2 =0.95, 95% CI: 0.94-0.96; p<0.001) and stronger than correlations between running speed and PL/min (r 2 =0.80, 95% CI: 0.73-0.87; p<0.001). Differences between measured and predicted AvF Net were small during jogging and running (<1%), but large for basketball movements including jumping, change-of-direction and shuffling (15%-41%). As hypothesised, AvF Net differed by playing position (11%-16%; p <0.001) and reflected the additional demand upon players with larger body mass and lower movement efficiency. Both sprint speed and AvF Net reduced during the course of the BEST ( p ≤0.013). These findings confirm the construct validity of AvF Net to quantify the external demand of basketball movements. Accelerometry-derived net force has the potential to quantify the external demands of basketballers during training and competition. © Georg Thieme Verlag KG Stuttgart · New York.

  18. Polymers films with indandione derivatives as alternatives to azobenzene polymers for optical patterning

    Energy Technology Data Exchange (ETDEWEB)

    Stiller, B. [University of Potsdam, Institute of Physics, Am Neuen Palais 10, 14469 Potsdam (Germany)], E-mail: busti@rz.uni-potsdam.de; Saphiannikova, M. [Leibniz Institute of Polymer Research, Hohe Strasse 6, D-01069 Dresden (Germany); Morawetz, K. [University of Potsdam, Institute of Physics, Am Neuen Palais 10, 14469 Potsdam (Germany); Ilnytskyi, J. [Institute for Condensed Matter Physics, 1 Svientsitskii Str., 79011, Lviv (Ukraine); Neher, D. [University of Potsdam, Institute of Physics, Am Neuen Palais 10, 14469 Potsdam (Germany); Muzikante, I. [Institute of Solid State Physics, University of Latvia, Kengaraga Str. 8, Riga, LV 1063 (Latvia); Pastors, P.; Kampars, V. [Riga Technical University, Azenes Str. 14/24, Riga LV-1048 (Latvia)

    2008-10-31

    Surface relief gratings (SRGs) on organic thin films are studied extensively for both scientific interest and in relevance to the applications. Among the chromophores being used the azobenzenes showed the best performance, but the use of alternative photo-sensitive groups provides better general understanding of the phenomena. A thermodynamic theory and molecular dynamics simulations of photoinduced effects are discussed. In this study we use indandione derivatives, known as promising materials for photonics applications, as an alternative to the azobenzenes. We consider their photoreactions when incorporated into a polymer film. One of interesting features is the spectral dependence of the diffraction of indandione containing gratings, which is observed and discussed.

  19. Ngram-derived pattern recognition for the detection and prediction of epileptic seizures.

    Directory of Open Access Journals (Sweden)

    Amir Eftekhar

    Full Text Available This work presents a new method that combines symbol dynamics methodologies with an Ngram algorithm for the detection and prediction of epileptic seizures. The presented approach specifically applies Ngram-based pattern recognition, after data pre-processing, with similarity metrics, including the Hamming distance and Needlman-Wunsch algorithm, for identifying unique patterns within epochs of time. Pattern counts within each epoch are used as measures to determine seizure detection and prediction markers. Using 623 hours of intracranial electrocorticogram recordings from 21 patients containing a total of 87 seizures, the sensitivity and false prediction/detection rates of this method are quantified. Results are quantified using individual seizures within each case for training of thresholds and prediction time windows. The statistical significance of the predictive power is further investigated. We show that the method presented herein, has significant predictive power in up to 100% of temporal lobe cases, with sensitivities of up to 70-100% and low false predictions (dependant on training procedure. The cases of highest false predictions are found in the frontal origin with 0.31-0.61 false predictions per hour and with significance in 18 out of 21 cases. On average, a prediction sensitivity of 93.81% and false prediction rate of approximately 0.06 false predictions per hour are achieved in the best case scenario. This compares to previous work utilising the same data set that has shown sensitivities of up to 40-50% for a false prediction rate of less than 0.15/hour.

  20. Spatio-temporal patterns in the north-western Mediterranean from MERIS derived chlorophyll a concentration

    Directory of Open Access Journals (Sweden)

    Ana Gordoa

    2008-12-01

    Full Text Available We address the major surface signatures of chlorophyll a in the Catalan Sea within the context of the dynamics of the north-western Mediterranean basin. Monthly composites from MERIS measurements and CHL products for Case 1 waters were analysed from June 2002 to June 2005. Composite images of variability were used to identify surface dynamics. The results showed that coastal and open sea waters were separated by a belt of low variability, a permanent oligotrophic belt that is noticeable with respect to the bloom conditions of the surrounding areas. The width of this Catalan Oligotrophic Belt (COB located along the continental slope, varied between 17 and 30 km and became blurred in the southernmost area. The chlorophyll a temporal pattern over the shelf showed an almost steady increase from September to March. A similar behaviour but with lower concentrations was observed in oceanic waters. Both temporal patterns showed a disruption during January and/or February that coincided with the well known deep water formation event in the Gulf of Lions. In 2004, the convection was weaker and the offshore temporal trend was not disrupted; however, the opposite was observed in 2005. The spatial chlorophyll a distribution of oceanic waters presented a clear north-south decreasing trend, while the coastal distribution did not show any latitudinal patterns but rather peaks in the areas enriched by river runoff. The observed seasonality was similar to the one published from SeaWiFS data and slightly different from the seasonality shown by CZCS data. Nevertheless, we did not discard the possibility that some of the observed seasonal differences could be a true temporal shift in chlorophyll a production.

  1. Ancestral and derived attributes of the dlx gene repertoire, cluster structure and expression patterns in an African cichlid fish

    Directory of Open Access Journals (Sweden)

    Renz Adina J

    2011-01-01

    Full Text Available Abstract Background Cichlid fishes have undergone rapid, expansive evolutionary radiations that are manifested in the diversification of their trophic morphologies, tooth patterning and coloration. Understanding the molecular mechanisms that underlie the cichlids' unique patterns of evolution requires a thorough examination of genes that pattern the neural crest, from which these diverse phenotypes are derived. Among those genes, the homeobox-containing Dlx gene family is of particular interest since it is involved in the patterning of the brain, jaws and teeth. Results In this study, we characterized the dlx genes of an African cichlid fish, Astatotilapia burtoni, to provide a baseline to later allow cross-species comparison within Cichlidae. We identified seven dlx paralogs (dlx1a, -2a, -4a, -3b, -4b, -5a and -6a, whose orthologies were validated with molecular phylogenetic trees. The intergenic regions of three dlx gene clusters (dlx1a-2a, dlx3b-4b, and dlx5a-6a were amplified with long PCR. Intensive cross-species comparison revealed a number of conserved non-coding elements (CNEs that are shared with other percomorph fishes. This analysis highlighted additional lineage-specific gains/losses of CNEs in different teleost fish lineages and a novel CNE that had previously not been identified. Our gene expression analyses revealed overlapping but distinct expression of dlx orthologs in the developing brain and pharyngeal arches. Notably, four of the seven A. burtoni dlx genes, dlx2a, dlx3b, dlx4a and dlx5a, were expressed in the developing pharyngeal teeth. Conclusion This comparative study of the dlx genes of A. burtoni has deepened our knowledge of the diversity of the Dlx gene family, in terms of gene repertoire, expression patterns and non-coding elements. We have identified possible cichlid lineage-specific changes, including losses of a subset of dlx expression domains in the pharyngeal teeth, which will be the targets of future functional

  2. A method for stochastic constrained optimization using derivative-free surrogate pattern search and collocation

    International Nuclear Information System (INIS)

    Sankaran, Sethuraman; Audet, Charles; Marsden, Alison L.

    2010-01-01

    Recent advances in coupling novel optimization methods to large-scale computing problems have opened the door to tackling a diverse set of physically realistic engineering design problems. A large computational overhead is associated with computing the cost function for most practical problems involving complex physical phenomena. Such problems are also plagued with uncertainties in a diverse set of parameters. We present a novel stochastic derivative-free optimization approach for tackling such problems. Our method extends the previously developed surrogate management framework (SMF) to allow for uncertainties in both simulation parameters and design variables. The stochastic collocation scheme is employed for stochastic variables whereas Kriging based surrogate functions are employed for the cost function. This approach is tested on four numerical optimization problems and is shown to have significant improvement in efficiency over traditional Monte-Carlo schemes. Problems with multiple probabilistic constraints are also discussed.

  3. Influence of satellite-derived rainfall patterns on plague occurrence in northeast Tanzania

    Directory of Open Access Journals (Sweden)

    Kimaro Didas

    2010-12-01

    Full Text Available Abstract Background In the tropics, rainfall data are seldom accurately recorded, and are often discontinuous in time. In the scope of plague-research in northeast Tanzania, we adapted previous research to reconstruct rainfall patterns at a suitable resolution (1 km, based on time series of NDVI: more accurate satellite imagery was used, in the form of MODIS NDVI, and rainfall data were collected from the TRMM sensors instead of in situ data. First, we established a significant relationship between monthly rainfall and monthly composited MODIS NDVI. The established linear relationship was then used to reconstruct historic precipitation patterns over a mountainous area in northeastern Tanzania. Results We validated the resulting precipitation estimates with in situ rainfall time series of three meteorological stations located in the study area. Taking the region's topography into account, a correlation coefficient of 0.66 was obtained for two of the three meteorological stations. Our results suggest that the adapted strategy can be applied fruitfully to estimate rainfall variability and seasonality, despite the underestimation of overall rainfall rates. Based on this model, rainfall in previous years (1986 is modelled to obtain a dataset with which we can compare plague occurrence in the area. A positive correlation of 82% is obtained between high rainfall rates and plague incidence with a two month lag between rainfall and plague cases. Conclusions We conclude that the obtained results are satisfactory in support of the human plague research in which this study is embedded, and that this approach can be applied in other studies with similar goals.

  4. Equivalent models of wind farms by using aggregated wind turbines and equivalent winds

    International Nuclear Information System (INIS)

    Fernandez, L.M.; Garcia, C.A.; Saenz, J.R.; Jurado, F.

    2009-01-01

    As a result of the increasing wind farms penetration on power systems, the wind farms begin to influence power system, and therefore the modeling of wind farms has become an interesting research topic. In this paper, new equivalent models of wind farms equipped with wind turbines based on squirrel-cage induction generators and doubly-fed induction generators are proposed to represent the collective behavior on large power systems simulations, instead of using a complete model of wind farms where all the wind turbines are modeled. The models proposed here are based on aggregating wind turbines into an equivalent wind turbine which receives an equivalent wind of the ones incident on the aggregated wind turbines. The equivalent wind turbine presents re-scaled power capacity and the same complete model as the individual wind turbines, which supposes the main feature of the present equivalent models. Two equivalent winds are evaluated in this work: (1) the average wind from the ones incident on the aggregated wind turbines with similar winds, and (2) an equivalent incoming wind derived from the power curve and the wind incident on each wind turbine. The effectiveness of the equivalent models to represent the collective response of the wind farm at the point of common coupling to grid is demonstrated by comparison with the wind farm response obtained from the detailed model during power system dynamic simulations, such as wind fluctuations and a grid disturbance. The present models can be used for grid integration studies of large power system with an important reduction of the model order and the computation time

  5. Conserved versus derived patterns of controlled cell death during the embryonic development of two species of Onychophora (velvet worms).

    Science.gov (United States)

    Treffkorn, Sandra; Mayer, Georg

    2017-05-01

    Apoptosis is involved in various developmental processes, including cell migration and tissue and organ formation. Some of these processes are conserved across metazoans, while others are specific to particular taxa. Although the patterns of apoptosis have been investigated in arthropods, no corresponding data are available from one of their closest relatives, the Onychophora (velvet worms). We analyzed the patterns of apoptosis in embryos of two onychophoran species: the lecithotrophic/matrotrophic viviparous peripatopsid Euperipatoides rowelli, and the placentotrophic viviparous peripatid Principapillatus hitoyensis. Our data show that apoptosis occurs early in development and might be responsible for the degeneration of extra-embryonic tissues. Moreover, apoptosis might be involved in the morphogenesis of the ventral and preventral organs in both species and occurs additionally in the placental stalk of P. hitoyensis. Despite the different developmental modes in these onychophoran species, our data suggest that patterns of apoptosis are conserved among onychophorans. While apoptosis in the dorsal extra-embryonic tissue might contribute to dorsal closure-a process also known from arthropods-the involvement of apoptosis in ventral closure might be unique to onychophorans. Apoptosis in the placental stalk of P. hitoyensis is most likely a derived feature of the placentotrophic onychophorans. Developmental Dynamics 246:403-416, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  6. Barotropic wind-driven circulation patterns in a closed rectangular basin of variable depth influenced by a peninsula or an island

    Directory of Open Access Journals (Sweden)

    B. V. Chubarenko

    Full Text Available We study how a coastal obstruction (peninsula or coastal island affects the three-dimensional barotropic currents in an oblong rectangular basin with variable bathymetry across the basin width. The transverse depth profile is asymmetric and the peninsula or island lies in the middle of the long side of the rectangle. A semi-spectral model for the Boussinesq-approximated shallow water equations, developed in Haidvogel et al. and altered for semi-implicit numerical integration in time in Wang and Hutter, is used to find the steady barotropic state circulation pattern to external winds. The structural (qualitative rearrangements and quanti2tative features of the current pattern are studied under four principal wind directions and different lengths of the peninsula and its inclination relative to the shore. The essentially non-linear relationships of the water flux between the two sub-basins (formed by the obstructing peninsula and the corresponding cross-sectional area left open are found and analysed. It is further analysed whether the depth-integrated model, usually adopted by others, is meaningful when applied to the water exchange problems. The flow through the channel narrowing is quantitatively estimated and compared with the three-dimensional results. The dynamics of the vortex structure and the identification of the up-welling/down-welling zones around the obstruction are discussed in detail. The influence of the transformation of the peninsula into a coastal island on the global basin circulation is considered as are the currents in the channel. The geometric and physical reasons for the anisotropy of the current structure which prevail through all obtained solutions are also discussed.

    Key words: Oceanography: general (limnology; numerical modeling - Oceanography: physical (currents

  7. Barotropic wind-driven circulation patterns in a closed rectangular basin of variable depth influenced by a peninsula or an island

    Directory of Open Access Journals (Sweden)

    B. V. Chubarenko

    2000-06-01

    Full Text Available We study how a coastal obstruction (peninsula or coastal island affects the three-dimensional barotropic currents in an oblong rectangular basin with variable bathymetry across the basin width. The transverse depth profile is asymmetric and the peninsula or island lies in the middle of the long side of the rectangle. A semi-spectral model for the Boussinesq-approximated shallow water equations, developed in Haidvogel et al. and altered for semi-implicit numerical integration in time in Wang and Hutter, is used to find the steady barotropic state circulation pattern to external winds. The structural (qualitative rearrangements and quanti2tative features of the current pattern are studied under four principal wind directions and different lengths of the peninsula and its inclination relative to the shore. The essentially non-linear relationships of the water flux between the two sub-basins (formed by the obstructing peninsula and the corresponding cross-sectional area left open are found and analysed. It is further analysed whether the depth-integrated model, usually adopted by others, is meaningful when applied to the water exchange problems. The flow through the channel narrowing is quantitatively estimated and compared with the three-dimensional results. The dynamics of the vortex structure and the identification of the up-welling/down-welling zones around the obstruction are discussed in detail. The influence of the transformation of the peninsula into a coastal island on the global basin circulation is considered as are the currents in the channel. The geometric and physical reasons for the anisotropy of the current structure which prevail through all obtained solutions are also discussed.Key words: Oceanography: general (limnology; numerical modeling - Oceanography: physical (currents

  8. Using GPS-derived speed patterns for recognition of transport modes in adults.

    Science.gov (United States)

    Huss, Anke; Beekhuizen, Johan; Kromhout, Hans; Vermeulen, Roel

    2014-10-11

    Identification of active or sedentary modes of transport is of relevance for studies assessing physical activity or addressing exposure assessment. We assessed in a proof-of-principle study if speed as logged by GPSs could be used to identify modes of transport (walking, bicycling, and motorized transport: car, bus or train). 12 persons commuting to work walking, bicycling or with motorized transport carried GPSs for two commutes and recorded their mode of transport. We evaluated seven speed metrics: mean, 95th percentile of speed, standard deviation of the mean, rate-of-change, standardized-rate-of-change, acceleration and deceleration. We assessed which speed metric would best identify the transport mode using discriminant analyses. We applied cross validation and calculated agreement (Cohen's Kappa) between actual and derived modes of transport. Mode of transport was reliably classified whenever a person used a mode of transport for longer than one minute. Best results were observed when using the 95th percentile of speed, acceleration and deceleration (kappa 0.73). When we combined all motorized traffic into one category, kappa increased to 0.95. GPS-measured speed enable the identification of modes of transport. Given the current low costs of GPS devices and the built-in capacity of GPS tracking in most smartphones, the use of such devices in large epidemiological studies may facilitate the assessment of physical activity related to transport modes, or improve exposure assessment using automated travel mode detection.

  9. Sensing the wind profile

    Energy Technology Data Exchange (ETDEWEB)

    Pena, A.

    2009-03-15

    This thesis consists of two parts. The first is a synopsis of the theoretical progress of the study that is based on a number of journal papers. The papers, which constitute the second part of the report, aim to analyze, measure, and model the wind prole in and beyond the surface layer by combining observations from cup anemometers with lidars. The lidar is necessary to extend the measurements on masts at the Horns Rev offshore wind farm and over at land at Hoevsoere, Denmark. Both sensing techniques show a high degree of agreement for wind speed measurements performed at either sites. The wind speed measurements are averaged for several stability conditions and compare well with the surface-layer wind profile. At Hoevsoere, it is sufficient to scale the wind speed with the surface friction velocity, whereas at Horns Rev a new scaling is added, due to the variant roughness length. This new scaling is coupled to wind prole models derived for flow over the sea and tested against the wind proles up to 160 m at Horns Rev. The models, which account for the boundary-layer height in stable conditions, show better agreement with the measurements than compared to the traditional theory. Mixing-length parameterizations for the neutral wind prole compare well with length-scale measurements up to 300 m at Hoevsoere and 950 m at Leipzig. The mixing-length-derived wind proles strongly deviate from the logarithmic wind prole, but agree better with the wind speed measurements. The length-scale measurements are compared to the length scale derived from a spectral analysis performed up to 160 m at Hoevsoere showing high agreement. Mixing-length parameterizations are corrected to account for stability and used to derive wind prole models. These compared better to wind speed measurements up to 300 m at Hoevsoere than the surface-layer wind prole. The boundary-layer height is derived in nearneutral and stable conditions based on turbulent momentum uxes only and in unstable conditions

  10. Wind power prediction models

    Science.gov (United States)

    Levy, R.; Mcginness, H.

    1976-01-01

    Investigations were performed to predict the power available from the wind at the Goldstone, California, antenna site complex. The background for power prediction was derived from a statistical evaluation of available wind speed data records at this location and at nearby locations similarly situated within the Mojave desert. In addition to a model for power prediction over relatively long periods of time, an interim simulation model that produces sample wind speeds is described. The interim model furnishes uncorrelated sample speeds at hourly intervals that reproduce the statistical wind distribution at Goldstone. A stochastic simulation model to provide speed samples representative of both the statistical speed distributions and correlations is also discussed.

  11. Planktonic foraminifera-derived environmental DNA extracted from abyssal sediments preserves patterns of plankton macroecology

    Science.gov (United States)

    Morard, Raphaël; Lejzerowicz, Franck; Darling, Kate F.; Lecroq-Bennet, Béatrice; Winther Pedersen, Mikkel; Orlando, Ludovic; Pawlowski, Jan; Mulitza, Stefan; de Vargas, Colomban; Kucera, Michal

    2017-06-01

    Deep-sea sediments constitute a unique archive of ocean change, fueled by a permanent rain of mineral and organic remains from the surface ocean. Until now, paleo-ecological analyses of this archive have been mostly based on information from taxa leaving fossils. In theory, environmental DNA (eDNA) in the sediment has the potential to provide information on non-fossilized taxa, allowing more comprehensive interpretations of the fossil record. Yet, the process controlling the transport and deposition of eDNA onto the sediment and the extent to which it preserves the features of past oceanic biota remains unknown. Planktonic foraminifera are the ideal taxa to allow an assessment of the eDNA signal modification during deposition because their fossils are well preserved in the sediment and their morphological taxonomy is documented by DNA barcodes. Specifically, we re-analyze foraminiferal-specific metabarcodes from 31 deep-sea sediment samples, which were shown to contain a small fraction of sequences from planktonic foraminifera. We confirm that the largest portion of the metabarcode originates from benthic bottom-dwelling foraminifera, representing the in situ community, but a small portion (DNA is preserved in a range of marine sediment types, the composition of the recovered eDNA metabarcode is replicable and that both the similarity structure and the diversity pattern are preserved. Our results suggest that sedimentary eDNA could preserve the ecological structure of the entire pelagic community, including non-fossilized taxa, thus opening new avenues for paleoceanographic and paleoecological studies.

  12. The Use of MERRA-2 Near Surface Meteorology to Understand the Behavior of Planetary Boundary Layer heights Derived from Wind Profiler Data Over the US Great Plains

    Science.gov (United States)

    Molod, A.; Salmun, H.; Collow, A.

    2017-12-01

    The atmospheric general circulation model (GCM) that underlies the MERRA-2 reanalysis includesa suite of physical parameterizations that describe the processes that occur in theplanetary boundary layer (PBL). The data assimilation system assures that the atmosphericstate variables used as input to these parameterizations are constrained to the bestfit to all of the available observations. Many studies, however, have shown that the GCM-based estimates of MERRA-2 PBL heights are biased high, and so are not reliable forapplication related to constituent transport or the carbon cycle.A new 20-year record of PBL heights was derived from Wind Profiler (WP) backscatter data measuredat a wide network of stations throughout the US Great Plains and has been validated against independent estimates. The behavior of these PBL heights shows geographical and temporalvariations that are difficult to attribute to particular physical processes withoutadditional information that are not part of the observational record.In the present study, we use information on physical processes from MERRA-2 to understand the behavior of the WP derived PBL heights. The behavior of the annual cycle of both MERRA-2 and WP PBL heights shows three classes of behavior: (i) canonical, where the annual cyclefollows the annual cycle of the sun, (ii) delayed, where the PBL height reaches its annual maximum after the annual maximum of the solar insolation, and (iii) double maxima, wherethe PBL height begins to rise with the solar insolation but falls sometimes during the the summer and then rises again. Although the magnitude of these types of variations isdescribed by the WP PBL record, the explanation for these behaviors and the relationshipto local precipitation, temperature, hydrology and sensible and latent heat fluxes is articulated using information from MERRA-2.

  13. A generic probability based model to derive regional patterns of crops in time and space

    Science.gov (United States)

    Wattenbach, Martin; Luedtke, Stefan; Redweik, Richard; van Oijen, Marcel; Balkovic, Juraj; Reinds, Gert Jan

    2015-04-01

    Croplands are not only the key to human food supply, they also change the biophysical and biogeochemical properties of the land surface leading to changes in the water cycle, energy portioning, they influence soil erosion and substantially contribute to the amount of greenhouse gases entering the atmosphere. The effects of croplands on the environment depend on the type of crop and the associated management which both are related to the site conditions, economic boundary settings as well as preferences of individual farmers. The method described here is designed to predict the most probable crop to appear at a given location and time. The method uses statistical crop area information on NUTS2 level from EUROSTAT and the Common Agricultural Policy Regionalized Impact Model (CAPRI) as observation. These crops are then spatially disaggregated to the 1 x 1 km grid scale within the region, using the assumption that the probability of a crop appearing at a given location and a given year depends on a) the suitability of the land for the cultivation of the crop derived from the MARS Crop Yield Forecast System (MCYFS) and b) expert knowledge of agricultural practices. The latter includes knowledge concerning the feasibility of one crop following another (e.g. a late-maturing crop might leave too little time for the establishment of a winter cereal crop) and the need to combat weed infestations or crop diseases. The model is implemented in R and PostGIS. The quality of the generated crop sequences per grid cell is evaluated on the basis of the given statistics reported by the joint EU/CAPRI database. The assessment is given on NUTS2 level using per cent bias as a measure with a threshold of 15% as minimum quality. The results clearly indicates that crops with a large relative share within the administrative unit are not as error prone as crops that allocate only minor parts of the unit. However, still roughly 40% show an absolute per cent bias above the 15% threshold. This

  14. Deriving spatial and temporal patterns of coastal marsh aggradation from hurricane storm surge marker beds

    Science.gov (United States)

    Hodge, Joshua; Williams, Harry

    2016-12-01

    This study uses storm surge sediment beds deposited by Hurricanes Audrey (1957), Carla (1961), Rita (2005) and Ike (2008) to investigate spatial and temporal changes in marsh sedimentation on the McFaddin National Wildlife Refuge in Southeastern Texas. Fourteen sediment cores were collected along a transect extending 1230 m inland from the Gulf coast. Storm-surge-deposited sediment beds were identified by texture, organic content, carbonate content, the presence of marine microfossils and 137Cs dating. The hurricane-derived sediment beds facilitate assessment of changes in marsh sedimentation from nearshore to inland locations and over decadal to annual timescales. Spatial variation along the transect reflects varying contributions from three prevailing sediment sources: flooding, overwash and organic sedimentation from marsh plants. Over about the last decade, hurricane overwash has been the predominant sediment source for nearshore locations because of large sediment inputs from Hurricanes Rita and Ike. Farther inland, hurricane inputs diminish and sedimentation is dominated by deposition from flood waters and a larger organic component. Temporal variations in sedimentation reflect hurricane activity, changes in marsh surface elevation and degree of compaction of marsh sediments, which is time-dependent. There was little to no marsh sedimentation in the period 2008-2014, firstly because no hurricanes impacted the study area and secondly because overwash sedimentation prior to 2008 had increased nearshore marsh surface elevations by up to 0.68 m, reducing subsequent inputs from flooding. Marsh sedimentation rates were relatively high in the period 2005-2008, averaging 2.13 cm/year and possibly reflecting sediment contributions from Hurricanes Humberto and Gustav. However, these marsh sediments are highly organic and largely uncompacted. Older, deeper marsh deposits formed between 1961 and 2005 are less organic-rich, more compacted and have an average annual

  15. Genomic predictors for recurrence patterns of hepatocellular carcinoma: model derivation and validation.

    Directory of Open Access Journals (Sweden)

    Ji Hoon Kim

    2014-12-01

    Full Text Available BACKGROUND: Typically observed at 2 y after surgical resection, late recurrence is a major challenge in the management of hepatocellular carcinoma (HCC. We aimed to develop a genomic predictor that can identify patients at high risk for late recurrence and assess its clinical implications. METHODS AND FINDINGS: Systematic analysis of gene expression data from human liver undergoing hepatic injury and regeneration revealed a 233-gene signature that was significantly associated with late recurrence of HCC. Using this signature, we developed a prognostic predictor that can identify patients at high risk of late recurrence, and tested and validated the robustness of the predictor in patients (n = 396 who underwent surgery between 1990 and 2011 at four centers (210 recurrences during a median of 3.7 y of follow-up. In multivariate analysis, this signature was the strongest risk factor for late recurrence (hazard ratio, 2.2; 95% confidence interval, 1.3-3.7; p = 0.002. In contrast, our previously developed tumor-derived 65-gene risk score was significantly associated with early recurrence (p = 0.005 but not with late recurrence (p = 0.7. In multivariate analysis, the 65-gene risk score was the strongest risk factor for very early recurrence (<1 y after surgical resection (hazard ratio, 1.7; 95% confidence interval, 1.1-2.6; p = 0.01. The potential significance of STAT3 activation in late recurrence was predicted by gene network analysis and validated later. We also developed and validated 4- and 20-gene predictors from the full 233-gene predictor. The main limitation of the study is that most of the patients in our study were hepatitis B virus-positive. Further investigations are needed to test our prediction models in patients with different etiologies of HCC, such as hepatitis C virus. CONCLUSIONS: Two independently developed predictors reflected well the differences between early and late recurrence of HCC at the molecular level and provided new

  16. Planktonic foraminifera-derived environmental DNA extracted from abyssal sediments preserves patterns of plankton macroecology

    Directory of Open Access Journals (Sweden)

    R. Morard

    2017-06-01

    Full Text Available Deep-sea sediments constitute a unique archive of ocean change, fueled by a permanent rain of mineral and organic remains from the surface ocean. Until now, paleo-ecological analyses of this archive have been mostly based on information from taxa leaving fossils. In theory, environmental DNA (eDNA in the sediment has the potential to provide information on non-fossilized taxa, allowing more comprehensive interpretations of the fossil record. Yet, the process controlling the transport and deposition of eDNA onto the sediment and the extent to which it preserves the features of past oceanic biota remains unknown. Planktonic foraminifera are the ideal taxa to allow an assessment of the eDNA signal modification during deposition because their fossils are well preserved in the sediment and their morphological taxonomy is documented by DNA barcodes. Specifically, we re-analyze foraminiferal-specific metabarcodes from 31 deep-sea sediment samples, which were shown to contain a small fraction of sequences from planktonic foraminifera. We confirm that the largest portion of the metabarcode originates from benthic bottom-dwelling foraminifera, representing the in situ community, but a small portion (< 10 % of the metabarcodes can be unambiguously assigned to planktonic taxa. These organisms live exclusively in the surface ocean and the recovered barcodes thus represent an allochthonous component deposited with the rain of organic remains from the surface ocean. We take advantage of the planktonic foraminifera portion of the metabarcodes to establish to what extent the structure of the surface ocean biota is preserved in sedimentary eDNA. We show that planktonic foraminifera DNA is preserved in a range of marine sediment types, the composition of the recovered eDNA metabarcode is replicable and that both the similarity structure and the diversity pattern are preserved. Our results suggest that sedimentary eDNA could preserve the ecological structure of

  17. Summertime wind climate in Yerevan: valley wind systems

    Science.gov (United States)

    Gevorgyan, Artur

    2017-03-01

    1992-2014 wind climatology analysis in Yerevan is presented with particular focus given to the summertime thermally induced valley wind systems. Persistence high winds are observed in Yerevan during July-August months when the study region is strongly affected by a heat-driven plain-plateau circulation. The local valley winds arrive in Yerevan in the evening hours, generally, from 1500 to 1800 UTC, leading to rapid enhancement of wind speeds and dramatic changes in wind direction. Valley-winds significantly impact the local climate of Yerevan, which is a densely populated city. These winds moderate evening temperatures after hot and dry weather conditions observed during summertime afternoons. On the other hand, valley winds result in significantly higher nocturnal temperatures and more frequent occurrence of warm nights (tn90p) in Yerevan due to stronger turbulent mixing of boundary layer preventing strong surface cooling and temperature drop in nighttime and morning hours. The applied WRF-ARW limited area model is able to simulate the key features of the observed spatial pattern of surface winds in Armenia associated with significant terrain channeling, wind curls, etc. By contrast, ECMWF EPS global model fails to capture mesoscale and local wind systems over Armenia. However, the results of statistical verification of surface winds in Yerevan showed that substantial biases are present in WRF 18-h wind forecasts, as well as, the temporal variability of observed surface winds is not reproduced adequately in WRF-ARW model.

  18. Empirically-derived food patterns and the risk of total mortality and cardiovascular events in the PREDIMED study.

    Science.gov (United States)

    Martínez-González, Miguel A; Zazpe, Itziar; Razquin, Cristina; Sánchez-Tainta, Ana; Corella, Dolores; Salas-Salvadó, Jordi; Toledo, Estefanía; Ros, Emilio; Muñoz, Miguel Ángel; Recondo, Javier; Gómez-Gracia, Enrique; Fiol, Miquel; Lapetra, José; Buil-Cosiales, Pilar; Serra-Majem, Lluis; Pinto, Xavier; Schröder, Helmut; Tur, Josep A; Sorli, José V; Lamuela-Raventós, Rosa M; Estruch, Ramón

    2015-10-01

    There is little evidence on post hoc-derived dietary patterns (DP) and all-cause mortality in Southern-European populations. Furthermore, the potential effect modification of a DP by a nutritional intervention has not been sufficiently assessed. We assessed the association between a posteriori defined baseline major DP and total mortality or cardiovascular events within each of the three arms of a large primary prevention trial (PREDIMED) where participants were randomized to two active interventions with Mediterranean-type diets or to a control group (allocated to a low-fat diet). We followed-up 7216 participants for a median of 4.3 years. A validated 137-item food-frequency questionnaire was administered. Baseline DP were ascertained through factor analysis based on 34 predefined groups. Cox regression models were used to estimate multivariable-adjusted hazard ratios (HR) for cardiovascular disease (CVD) or mortality across quartiles of DP within each of the three arms of the trial. We identified two major baseline DP: the first DP was rich in red and processed meats, alcohol, refined grains and whole dairy products and was labeled Western dietary pattern (WDP). The second DP corresponded to a "Mediterranean-type" dietary pattern (MDP). During follow-up, 328 participants died. After controlling for potential confounders, higher baseline adherence to the MDP was associated with lower risk of CVD (adjusted HR for fourth vs. first quartile: 0.52; 95% CI (Confidence Interval): 0.36, 0.74; p-trend <0.001) and all-cause mortality (adjusted HR: 0.53; 95% CI: 0.38, 0.75; p-trend <0.001), regardless of the allocated arm of the trial. An increasing mortality rate was found across increasing quartiles of the WDP in the control group (allocated to a low-fat diet), though the linear trend was not statistically significant (p = 0.098). Higher adherence to an empirically-derived MDP at baseline was associated with a reduced risk of CVD and mortality in the PREDIMED trial

  19. Wind Energy

    International Nuclear Information System (INIS)

    Rodriguez D, J.M.

    1998-01-01

    The general theory of the wind energy conversion systems is presented. The availability of the wind resource in Colombia and the ranges of the speed of the wind in those which is possible economically to use the wind turbines are described. It is continued with a description of the principal technological characteristics of the wind turbines and are split into wind power and wind-powered pumps; and its use in large quantities grouped in wind farms or in autonomous systems. Finally, its costs and its environmental impact are presented

  20. Prediction of spatial patterns of collapsed pipes in loess-derived soils in a temperate humid climate using logistic regression

    Science.gov (United States)

    Verachtert, E.; Den Eeckhaut, M. Van; Poesen, J.; Govers, G.; Deckers, J.

    2011-07-01

    Soil piping (tunnel erosion) has been recognised as an important erosion process in collapsible loess-derived soils of temperate humid climates, which can cause collapse of the topsoil and formation of discontinuous gullies. Information about the spatial patterns of collapsed pipes and regional models describing these patterns is still limited. Therefore, this study aims at better understanding the factors controlling the spatial distribution and predicting pipe collapse. A dataset with parcels suffering from collapsed pipes (n = 560) and parcels without collapsed pipes was obtained through a regional survey in a 236 km² study area in the Flemish Ardennes (Belgium). Logistic regression was applied to find the best model describing the relationship between the presence/absence of a collapsed pipe and a set of independent explanatory variables (i.e. slope gradient, drainage area, distance-to-thalweg, curvature, aspect, soil type and lithology). Special attention was paid to the selection procedure of the grid cells without collapsed pipes. Apart from the first piping susceptibility map created by logistic regression modelling, a second map was made based on topographical thresholds of slope gradient and upslope drainage area. The logistic regression model allowed identification of the most important factors controlling pipe collapse. Pipes are much more likely to occur when a topographical threshold depending on both slope gradient and upslope area is exceeded in zones with a sufficient water supply (due to topographical convergence and/or the presence of a clay-rich lithology). On the other hand, the use of slope-area thresholds only results in reasonable predictions of piping susceptibility, with minimum information.

  1. Aeroservoelasticity of Wind Turbines

    DEFF Research Database (Denmark)

    Kallesøe, Bjarne Skovmose

    2007-01-01

    This thesis deals with the fundamental aeroelastic interaction between structural motion, Pitch action and control for a wind turbine blade. As wind turbines become larger, the interaction between pitch action, blade motion, aerodynamic forces, and control become even more important to understand...... to a 2D blade section model, and it can be used instead of this in many applications, giving a transparent connection to a real wind turbine blade. In this work the aeroelastic blade model is used to analyze interaction between pitch action, blade motion and wind speed variations. Furthermore the model...... conditions. So, a new aeroelastic blade model has been derived, which includes important features of large wind turbines, yet simple enough to be suitable for analytical analysis and control design....

  2. [Estimation of the effect derived from wind erosion of soil and dust emission in Tianjin suburbs on the central district based on WEPS model].

    Science.gov (United States)

    Chen, Li; Han, Ting-Ting; Li, Tao; Ji, Ya-Qin; Bai, Zhi-Peng; Wang, Bin

    2012-07-01

    Due to the lack of a prediction model for current wind erosion in China and the slow development for such models, this study aims to predict the wind erosion of soil and the dust emission and develop a prediction model for wind erosion in Tianjin by investigating the structure, parameter systems and the relationships among the parameter systems of the prediction models for wind erosion in typical areas, using the U.S. wind erosion prediction system (WEPS) as reference. Based on the remote sensing technique and the test data, a parameter system was established for the prediction model of wind erosion and dust emission, and a model was developed that was suitable for the prediction of wind erosion and dust emission in Tianjin. Tianjin was divided into 11 080 blocks with a resolution of 1 x 1 km2, among which 7 778 dust emitting blocks were selected. The parameters of the blocks were localized, including longitude, latitude, elevation and direction, etc.. The database files of blocks were localized, including wind file, climate file, soil file and management file. The weps. run file was edited. Based on Microsoft Visualstudio 2008, secondary development was done using C + + language, and the dust fluxes of 7 778 blocks were estimated, including creep and saltation fluxes, suspension fluxes and PM10 fluxes. Based on the parameters of wind tunnel experiments in Inner Mongolia, the soil measurement data and climate data in suburbs of Tianjin, the wind erosion module, wind erosion fluxes, dust emission release modulus and dust release fluxes were calculated for the four seasons and the whole year in suburbs of Tianjin. In 2009, the total creep and saltation fluxes, suspension fluxes and PM10 fluxes in the suburbs of Tianjin were 2.54 x 10(6) t, 1.25 x 10(7) t and 9.04 x 10(5) t, respectively, among which, the parts pointing to the central district were 5.61 x 10(5) t, 2.89 x 10(6) t and 2.03 x 10(5) t, respectively.

  3. Characterization of progenitor cells derived from torn human rotator cuff tendons by gene expression patterns of chondrogenesis, osteogenesis, and adipogenesis.

    Science.gov (United States)

    Nagura, Issei; Kokubu, Takeshi; Mifune, Yutaka; Inui, Atsuyuki; Takase, Fumiaki; Ueda, Yasuhiro; Kataoka, Takeshi; Kurosaka, Masahiro

    2016-03-31

    It is important to regenerate the tendon-to-bone interface after rotator cuff repair to prevent re-tears. The cells from torn human rotator cuff were targeted, and their capacity for multilineage differentiation was investigated. The edges of the rotator cuff were harvested during arthroscopic rotator cuff repair from nine patients, minced into pieces, and cultured on dishes. Adherent cells were cultured, phenotypically characterized. Then expandability, differentiation potential and gene expression were analyzed. Flow cytometry revealed that the mesenchymal stem cells (MSC)-related markers CD29, CD44, CD105, and CD166 were positive. However, CD14, CD34, and CD45 were negative. On RT-PCR analyses, the cells showed osteogenic, adipogenic, and chondrogenic potential after 3 weeks of culture under the respective differentiation conditions. In addition, SOX9, type II collagen, and type X collagen expression patterns during chondrogenesis were similar to those of endochondral ossification at the enthesis. The cells derived from torn human rotator cuff are multipotent mesenchymal stem cells with the ability to undergo multilineage differentiation, suggesting that MSCs form this tissue could be regenerative capacity for potential self-repair.

  4. Subsidence and current strain patterns on Tenerife Island (Canary Archipelago, Spain) derived from continuous GNSS time series (2008-2015)

    Science.gov (United States)

    Sánchez-Alzola, A.; Martí, J.; García-Yeguas, A.; Gil, A. J.

    2016-11-01

    In this paper we present the current crustal deformation model of Tenerife Island derived from daily CGPS time series processing (2008-2015). Our results include the position time series, a global velocity estimation and the current crustal deformation on the island in terms of strain tensors. We detect a measurable subsidence of 1.5-2 mm/yr. in the proximities of the Cañadas-Teide-Pico Viejo (CTPV) complex. These values are higher in the central part of the complex and could be explained by a lateral spreading of the elastic lithosphere combined with the effect of the drastic descent of the water table in the island experienced during recent decades. The results show that the Anaga massif is stable in both its horizontal and vertical components. The strain tensor analysis shows a 70 nstrain/yr. E-W compression in the central complex, perpendicular to the 2004 sismo-volcanic area, and 50 nstrain/yr. SW-NE extension towards the Northeast ridge. The residual velocity and strain patterns coincide with a decline in volcanic activity since the 2004 unrest.

  5. Cross-Sectional Associations between Empirically-Derived Dietary Patterns and Indicators of Disease Risk among University Students

    Directory of Open Access Journals (Sweden)

    Stacy A. Blondin

    2015-12-01

    Full Text Available The transition from adolescence to adulthood is a unique period during which lifelong dietary habits are shaped. Dietary patterns (DPs among young adults attending college have not been adequately described, and associations between DPs and indicators of disease risk are not well understood in this age group. Dietary data were collected from undergraduates participating in the Tufts Longitudinal Health Study (TLHS; 1998–2007 by Food Frequency Questionnaire (FFQ; n = 1323. DPs were derived using principal components analysis with varimax rotation. Scree plots; eigenvalues; factor loadings; and previous studies were used to determine and label the DPs retained. Cross-sectional relationships between DP scores and anthropometric measures (percent body fat (PBF and (BMI and lipid biomarkers (total; HDL and LDL cholesterol; and triglycerides were assessed with multivariable regression models; adjusted for demographics; physical activity; smoking; intention to gain/lose weight; and total energy intake. Effect modification by sex was tested. Three DPs were identified: Prudent; Western; and Alcohol. Greater adherence to the Prudent DP was associated with favorable anthropometric outcomes. The Alcohol DP was associated with a favorable lipid profile. Associations between the Western DP and blood lipids differed by sex; with unfavorable impact observed only among males. Our findings add to the literature linking DPs in young adults with measurable adiposity and cardiometabolic outcomes; suggesting that improving nutrition among college students could reduce chronic disease risk.

  6. The pattern of complaints about Australian wind farms does not match the establishment and distribution of turbines: support for the psychogenic, 'communicated disease' hypothesis.

    Science.gov (United States)

    Chapman, Simon; St George, Alexis; Waller, Karen; Cakic, Vince

    2013-01-01

    With often florid allegations about health problems arising from wind turbine exposure now widespread, nocebo effects potentially confound any future investigation of turbine health impact. Historical audits of health complaints are therefore important. We test 4 hypotheses relevant to psychogenic explanations of the variable timing and distribution of health and noise complaints about wind farms in Australia. All Australian wind farms (51 with 1634 turbines) operating 1993-2012. Records of complaints about noise or health from residents living near 51 Australian wind farms were obtained from all wind farm companies, and corroborated with complaints in submissions to 3 government public enquiries and news media records and court affidavits. These are expressed as proportions of estimated populations residing within 5 km of wind farms. There are large historical and geographical variations in wind farm complaints. 33/51 (64.7%) of Australian wind farms including 18/34 (52.9%) with turbine size >1 MW have never been subject to noise or health complaints. These 33 farms have an estimated 21,633 residents within 5 km and have operated complaint-free for a cumulative 267 years. Western Australia and Tasmania have seen no complaints. 129 individuals across Australia (1 in 254 residents) appear to have ever complained, with 94 (73%) being residents near 6 wind farms targeted by anti wind farm groups. The large majority 116/129(90%) of complainants made their first complaint after 2009 when anti wind farm groups began to add health concerns to their wider opposition. In the preceding years, health or noise complaints were rare despite large and small-turbine wind farms having operated for many years. The reported historical and geographical variations in complaints are consistent with psychogenic hypotheses that expressed health problems are "communicated diseases" with nocebo effects likely to play an important role in the aetiology of complaints.

  7. The Pattern of Complaints about Australian Wind Farms Does Not Match the Establishment and Distribution of Turbines: Support for the Psychogenic, ‘Communicated Disease’ Hypothesis

    Science.gov (United States)

    Chapman, Simon; St. George, Alexis; Waller, Karen; Cakic, Vince

    2013-01-01

    Background and Objectives With often florid allegations about health problems arising from wind turbine exposure now widespread, nocebo effects potentially confound any future investigation of turbine health impact. Historical audits of health complaints are therefore important. We test 4 hypotheses relevant to psychogenic explanations of the variable timing and distribution of health and noise complaints about wind farms in Australia. Setting All Australian wind farms (51 with 1634 turbines) operating 1993–2012. Methods Records of complaints about noise or health from residents living near 51 Australian wind farms were obtained from all wind farm companies, and corroborated with complaints in submissions to 3 government public enquiries and news media records and court affidavits. These are expressed as proportions of estimated populations residing within 5 km of wind farms. Results There are large historical and geographical variations in wind farm complaints. 33/51 (64.7%) of Australian wind farms including 18/34 (52.9%) with turbine size >1 MW have never been subject to noise or health complaints. These 33 farms have an estimated 21,633 residents within 5 km and have operated complaint-free for a cumulative 267 years. Western Australia and Tasmania have seen no complaints. 129 individuals across Australia (1 in 254 residents) appear to have ever complained, with 94 (73%) being residents near 6 wind farms targeted by anti wind farm groups. The large majority 116/129(90%) of complainants made their first complaint after 2009 when anti wind farm groups began to add health concerns to their wider opposition. In the preceding years, health or noise complaints were rare despite large and small-turbine wind farms having operated for many years. Conclusions The reported historical and geographical variations in complaints are consistent with psychogenic hypotheses that expressed health problems are “communicated diseases” with nocebo effects likely to play an

  8. Relationship Between Satellite-Derived Snow Cover and Snowmelt-Runoff Timing and Stream Power in the Wind River Range, Wyoming

    Science.gov (United States)

    Hall, Dorothy K.; Foster, James L.; DiGirolamo, Nicolo E.; Riggs, George A.

    2010-01-01

    Earlier onset of springtime weather including earlier snowmelt has been documented in the western United States over at least the last 50 years. Because the majority (>70%) of the water supply in the western U.S. comes from snowmelt, analysis of the declining spring snowpack (and shrinking glaciers) has important implications for streamflow management. The amount of water in a snowpack influences stream discharge which can also influence erosion and sediment transport by changing stream power, or the rate at which a stream can do work such as move sediment and erode the stream bed. The focus of this work is the Wind River Range (WRR) in west-central Wyoming. Ten years of Moderate-Resolution Imaging Spectroradiometer (MODIS) snow-cover, cloud- gap-filled (CGF) map products and 30 years of discharge and meteorological station data are studied. Streamflow data from six streams in the WRR drainage basins show lower annual discharge and earlier snowmelt in the decade of the 2000s than in the previous three decades, though no trend of either lower streamflow or earlier snowmelt was observed using MODIS snow-cover maps within the decade of the 2000s. Results show a statistically-significant trend at the 95% confidence level (or higher) of increasing weekly maximum air temperature (for three out of the five meteorological stations studied) in the decade of the 1970s, and also for the 40-year study period. MODIS-derived snow cover (percent of basin covered) measured on 30 April explains over 89% of the variance in discharge for maximum monthly streamflow in the decade of the 2000s using Spearman rank correlation analysis. We also investigated stream power for Bull Lake Creek Above Bull Lake from 1970 to 2009; a statistically-significant end toward reduced stream power was found (significant at the 90% confidence level). Observed changes in streamflow and stream power may be related to increasing weekly maximum air temperature measured during the 40-year study period. The

  9. Wind Structure and Wind Loading

    DEFF Research Database (Denmark)

    Brorsen, Michael

    The purpose of this note is to provide a short description of wind, i.e. of the flow in the atmosphere of the Earth and the loading caused by wind on structures. The description comprises: causes to the generation of windhe interaction between wind and the surface of the Earthhe stochastic nature...... of windhe interaction between wind and structures, where it is shown that wind loading depends strongly on this interaction...

  10. Plasma brain-derived neurotrophic factor and reverse dipping pattern of nocturnal blood pressure in patients with cardiovascular risk factors.

    Directory of Open Access Journals (Sweden)

    Manabu Kadoya

    Full Text Available Basic studies have shown that brain-derived neurotrophic factor (BDNF has critical roles in the survival, growth, maintenance, and death of central and peripheral neurons, while it is also involved in regulation of the autonomic nervous system. Furthermore, recent clinical studies have suggested potential role of plasma BDNF in the circulatory system.We investigated the mutual relationships among plasma BDNF, patterns of nocturnal blood pressure changes (dippers, non-dippers, extra-dippers, and reverse-dippers, and cardiac autonomic function as determined by heart rate variability (HRV.This was a cross-sectional study of patients registered in the Hyogo Sleep Cardio-Autonomic Atherosclerosis (HSCAA Study from October 2010 to November 2012.Two-hundred fifty patients with 1 or more cardiovascular risk factor(s (obesity, smoking, presence of cardiovascular event history, hypertension, dyslipidemia, diabetes mellitus, chronic kidney disease were enrolled.Plasma BDNF levels (natural logarithm transformed were significantly (p = 0.001 lower in reverse-dipper patients (7.18±0.69 pg/ml, mean ± SD, n = 36 as compared to dippers (7.86±0.86 pg/ml, n = 100. Multiple logistic regression analysis showed that BDNF (odds ratios: 0.417, 95% confidence interval: 0.228-0.762, P = 0.004 was the sole factor significantly and independently associated with the reverse-dippers as compared with dippers. Furthermore, plasma BDNF level was significantly and positively correlated with the time-domain (SDNN, SDANN5, CVRR and frequency-domain (LF of HRV parameters. Finally, multiple logistic regression analyses showed that the relationship between plasma BDNF and the reverse-dippers was weakened, yet remained significant or borderline significant even after adjusting for HRV parameters.Low plasma BDNF was independently associated with patients showing a reverse-dipper pattern of nocturnal blood pressure, in which an imbalance of cardiac autonomic function

  11. Comparison of SAR Wind Speed Retrieval Algorithms for Evaluating Offshore Wind Energy Resources

    DEFF Research Database (Denmark)

    Kozai, K.; Ohsawa, T.; Takeyama, Y.

    2010-01-01

    Envisat/ASAR-derived offshore wind speeds and energy densities based on 4 different SAR wind speed retrieval algorithms (CMOD4, CMOD-IFR2, CMOD5, CMOD5.N) are compared with observed wind speeds and energy densities for evaluating offshore wind energy resources. CMOD4 ignores effects of atmospheric...

  12. Dietary Patterns Derived Using Exploratory and Confirmatory Factor Analysis are Stable and Generalizable Across Race, Region, and Gender Subgroups in the REGARDS Study

    Science.gov (United States)

    Judd, Suzanne E.; Letter, Abraham J.; Shikany, James M.; Roth, David L.; Newby, P. K.

    2015-01-01

    Background: Examining diet as a whole using dietary patterns as exposures is a complementary method to using single food or nutrients in studies of diet and disease, but the generalizability of intake patterns across race, region, and gender in the United States has not been established. Objective: To employ rigorous statistical analysis to empirically derive dietary patterns in a large bi-racial, geographically diverse population and examine whether results are stable across population subgroups. Design: The present analysis utilized data from 21,636 participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study who completed the Block 98 food frequency questionnaire. We employed exploratory factor analysis and confirmatory factor analyses on 56 different food groups iteratively and examined differences by race, region, and sex to determine the optimal factor solution in our sample. Results: Five dietary patterns emerged: the “Convenience” pattern was characterized by mixed dishes; the “Plant-based” pattern by fruits, vegetables, and fish; the “Sweets/Fats” pattern by sweet snacks, desserts, and fats and oils; the “Southern” pattern by fried foods, organ meat, and sweetened beverages; and the “Alcohol/Salads” pattern by beer, wine, liquor, and salads. Differences were most pronounced in the Southern pattern with black participants, those residing in the Southeast, and participants not completing high school having the highest scores. Conclusion: Five meaningful dietary patterns emerged in the REGARDS study and showed strong congruence across race, sex, and region. Future research will examine associations between these patterns and health outcomes to better understand racial disparities in disease and inform prevention efforts. PMID:25988129

  13. Mean vertical wind in the mesosphere-lower thermosphere region (80–120 km deduced from the WINDII observations on board UARS

    Directory of Open Access Journals (Sweden)

    V. Fauliot

    1997-09-01

    Full Text Available The WINDII interferometer placed on board the Upper Atmosphere Research Satellite measures temperature and wind from the O(1S green-line emission in the Earth's mesosphere and lower thermosphere. It is a remote-sensing instrument providing the horizontal wind components. In this study, the vertical winds are derived using the continuity equation. Mean wind annually averaged at equinoxes and solstices is shown. Ascendance and subsidence to the order of 1–2 cm s–1 present a seasonal occurrence at the equator and tropics. Zonal Coriolis acceleration and adiabatic heating and cooling rate associated to the mean meridional and vertical circulations are evaluated. The line emission rate measured together with the horizontal wind shows structures in altitude and latitude correlated with the meridional and vertical wind patterns. The effect of wind advection is discussed.

  14. Mean vertical wind in the mesosphere-lower thermosphere region (80–120 km deduced from the WINDII observations on board UARS

    Directory of Open Access Journals (Sweden)

    V. Fauliot

    Full Text Available The WINDII interferometer placed on board the Upper Atmosphere Research Satellite measures temperature and wind from the O(1S green-line emission in the Earth's mesosphere and lower thermosphere. It is a remote-sensing instrument providing the horizontal wind components. In this study, the vertical winds are derived using the continuity equation. Mean wind annually averaged at equinoxes and solstices is shown. Ascendance and subsidence to the order of 1–2 cm s–1 present a seasonal occurrence at the equator and tropics. Zonal Coriolis acceleration and adiabatic heating and cooling rate associated to the mean meridional and vertical circulations are evaluated. The line emission rate measured together with the horizontal wind shows structures in altitude and latitude correlated with the meridional and vertical wind patterns. The effect of wind advection is discussed.

  15. Model of wind shear conditional on turbulence and its impact on wind turbine loads

    DEFF Research Database (Denmark)

    Dimitrov, Nikolay Krasimirov; Natarajan, Anand; Kelly, Mark C.

    2015-01-01

    fatigue load is achieved. The proposed wind shear model based on the wind measurements is thereby probabilistic in definition, with shear jointly distributed with wind turbulence. A simplified model for the wind shear exponent is further derived from the full stochastic model. The fatigue loads over......We analyse high-frequency wind velocity measurements from two test stations over a period of several years and at heights ranging from 60 to 200 m, with the objective to validate wind shear predictions as used in load simulations for wind turbine design. A validated wind shear model is thereby...... different turbine components are evaluated under the full wind measurements, using the developed wind shear model and with standard wind conditions prescribed in the IEC 61400-1 ed. 3. The results display the effect of the Wöhler exponent and reveal that under moderate turbulence, the effect of wind shear...

  16. Aerodynamic damping of nonlinearily wind-excited wind turbine blades

    NARCIS (Netherlands)

    Van der Male, P.; Van Dalen, K.N.; Metrikine, A.

    2013-01-01

    This paper presents the first step of the derivation of an aerodynamic damping matrix that can be adopted for the foundation design of a wind turbine. A single turbine blade is modelled as a discrete mass-spring system, representing the flap and edge wise motions. Nonlinear wind forcing is applied,

  17. Comprehensive evaluation of wind speed distribution models: A case study for North Dakota sites

    International Nuclear Information System (INIS)

    Zhou Junyi; Erdem, Ergin; Li Gong; Shi Jing

    2010-01-01

    Accurate analysis of long term wind data is critical to the estimation of wind energy potential for a candidate location and its nearby area. Investigating the wind speed distribution is one critical task for this purpose. This paper presents a comprehensive evaluation on probability density functions for the wind speed data from five representative sites in North Dakota. Besides the popular Weibull and Rayleigh distributions, we also include other distributions such as gamma, lognormal, inverse Gaussian, and maximum entropy principle (MEP) derived probability density functions (PDFs). Six goodness-of-fit (GOF) statistics are used to determine the appropriate distributions for the wind speed data for each site. It is found that no particular distribution outperforms others for all five sites, while Rayleigh distribution performs poorly for most of the sites. Similar to other models, the performances of MEP-derived PDFs in fitting wind speed data varies from site to site. Also, the results demonstrate that MEP-derived PDFs are flexible and have the potential to capture other possible distribution patterns of wind speed data. Meanwhile, different GOF statistics may generate inconsistent ranking orders of fit performance among the candidate PDFs. In addition, one comprehensive metric that combines all individual statistics is proposed to rank the overall performance for the chosen statistical distributions.

  18. Temporal Dietary Patterns Derived among the Adult Participants of the National Health and Nutrition Examination Survey 1999-2004 Are Associated with Diet Quality.

    Science.gov (United States)

    Eicher-Miller, Heather A; Khanna, Nitin; Boushey, Carol J; Gelfand, Saul B; Delp, Edward J

    2016-02-01

    Temporal dietary patterns, the distribution of energy or nutrient intakes observed over a period of time, is an emerging area of dietary patterns research that incorporates time of dietary intake with frequency and amount of intake to determine population clusters that may have similar characteristics or outcomes related to diet quality. We examined whether differences in diet quality were present between clusters of individuals with similar daily temporal dietary patterns. The first-day 24-hour dietary recall data from the cross-sectional National Health and Nutrition Examination Survey, 1999-2004, were used to determine proportional energy intake, time of intake, frequency of intake occasions, and mean diet quality. Data from 9,326 US adults aged 20 to 65 years were included. The mean diet quality, classified by the Healthy Eating Index-2005, of participant clusters with similar temporal dietary patterns derived on the basis of individual proportional energy intake, time of intake, and frequency of intake, were inferentially compared using multiple linear regression that controlled for potential confounders and other covariates (PDiet quality differences were present between US population clusters exhibiting similar daily temporal dietary patterns (Pdiet quality, demonstrating that elements beyond food and nutrient intake, such as time, can be incorporated with dietary patterns to determine links to diet quality that enhance knowledge of the complicated interplay of time and dietary patterns. Copyright © 2016 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  19. Profiles of Wind and Turbulence in the Coastal Atmospheric Boundary Layer of Lake Erie

    KAUST Repository

    Wang, H

    2014-06-16

    Prediction of wind resource in coastal zones is difficult due to the complexity of flow in the coastal atmospheric boundary layer (CABL). A three week campaign was conducted over Lake Erie in May 2013 to investigate wind characteristics and improve model parameterizations in the CABL. Vertical profiles of wind speed up to 200 m were measured onshore and offshore by lidar wind profilers, and horizontal gradients of wind speed by a 3-D scanning lidar. Turbulence data were collected from sonic anemometers deployed onshore and offshore. Numerical simulations were conducted with the Weather Research Forecasting (WRF) model with 2 nested domains down to a resolution of 1-km over the lake. Initial data analyses presented in this paper investigate complex flow patterns across the coast. Acceleration was observed up to 200 m above the surface for flow coming from the land to the water. However, by 7 km off the coast the wind field had not yet reached equilibrium with the new surface (water) conditions. The surface turbulence parameters over the water derived from the sonic data could not predict wind profiles observed by the ZephlR lidar located offshore. Horizontal wind speed gradients near the coast show the influence of atmospheric stability on flow dynamics. Wind profiles retrieved from the 3-D scanning lidar show evidence of nocturnal low level jets (LLJs). The WRF model was able to capture the occurrence of LLJ events, but its performance varied in predicting their intensity, duration, and the location of the jet core.

  20. Wind power

    International Nuclear Information System (INIS)

    Gipe, P.

    2007-01-01

    This book is a translation of the edition published in the USA under the title of ''wind power: renewable energy for home, farm and business''. In the wake of mass blackouts and energy crises, wind power remains a largely untapped resource of renewable energy. It is a booming worldwide industry whose technology, under the collective wing of aficionados like author Paul Gipe, is coming of age. Wind Power guides us through the emergent, sometimes daunting discourse on wind technology, giving frank explanations of how to use wind technology wisely and sound advice on how to avoid common mistakes. Since the mid-1970's, Paul Gipe has played a part in nearly every aspect of wind energy development from installing small turbines to promoting wind energy worldwide. As an American proponent of renewable energy, Gipe has earned the acclaim and respect of European energy specialists for years, but his arguments have often fallen on deaf ears at home. Today, the topic of wind power is cropping up everywhere from the beaches of Cape Cod to the Oregon-Washington border, and one wind turbine is capable of producing enough electricity per year to run 200 average American households. Now, Paul Gipe is back to shed light on this increasingly important energy source with a revised edition of Wind Power. Over the course of his career, Paul Gipe has been a proponent, participant, observer, and critic of the wind industry. His experience with wind has given rise to two previous books on the subject, Wind Energy Basics and Wind Power for Home and Business, which have sold over 50,000 copies. Wind Power for Home and Business has become a staple for both homeowners and professionals interested in the subject, and now, with energy prices soaring, interest in wind power is hitting an all-time high. With chapters on output and economics, Wind Power discloses how much you can expect from each method of wind technology, both in terms of energy and financial savings. The book updated models

  1. Multi-decadal Variability of the Wind Power Output

    Science.gov (United States)

    Kirchner Bossi, Nicolas; García-Herrera, Ricardo; Prieto, Luis; Trigo, Ricardo M.

    2014-05-01

    The knowledge of the long-term wind power variability is essential to provide a realistic outlook on the power output during the lifetime of a planned wind power project. In this work, the Power Output (Po) of a market wind turbine is simulated with a daily resolution for the period 1871-2009 at two different locations in Spain, one at the Central Iberian Plateau and another at the Gibraltar Strait Area. This is attained through a statistical downscaling of the daily wind conditions. It implements a Greedy Algorithm as classificator of a geostrophic-based wind predictor, which is derived by considering the SLP daily field from the 56 ensemble members of the longest homogeneous reanalysis available (20CR, 1871-2009). For calibration and validation purposes we use 10 years of wind observations (the predictand) at both sites. As a result, a series of 139 annual wind speed Probability Density Functions (PDF) are obtained, with a good performance in terms of wind speed uncertainty reduction (average daily wind speed MAE=1.48 m/s). The obtained centennial series allow to investigate the multi-decadal variability of wind power from different points of view. Significant periodicities around the 25-yr frequency band, as well as long-term linear trends are detected at both locations. In addition, a negative correlation is found between annual Po at both locations, evidencing the differences in the dynamical mechanisms ruling them (and possible complementary behavior). Furthermore, the impact that the three leading large-scale circulation patterns over Iberia (NAO, EA and SCAND) exert over wind power output is evaluated. Results show distinct (and non-stationary) couplings to these forcings depending on the geographical position and season or month. Moreover, significant non-stationary correlations are observed with the slow varying Atlantic Multidecadal Oscillation (AMO) index for both case studies. Finally, an empirical relationship is explored between the annual Po and the

  2. The Relationship of High-Latitude Thermospheric Wind With Ionospheric Horizontal Current, as Observed by CHAMP Satellite

    Science.gov (United States)

    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.

  3. A comparison between Nimbus 5 THIR and ITPR temperatures and derived winds with rawinsonde data obtained in the AVE 2 experiment

    Science.gov (United States)

    Arnold, J. E.; Scoggins, J. R.; Fuelberg, H. E.

    1976-01-01

    During the period of May 11 and 12, 1974, NASA conducted its second Atmospheric Variability Experiment (AVE II) over the eastern United States. In this time interval, two Nimbus 5 orbits crossed the AVE II area, providing a series of ITPR soundings as well as THIR data. Horizontal temperature mapping of the AVE II cloud field is examined using two grid print map scales. Implied cloud top heights are compared with maximum radar-echo top reports. In addition, shelter temperatures in areas of clear sky are compared with the surface temperatures as determined from 11.5 micrometer radiometer data of the THIR experiment. The ITPR sounding accuracy is evaluated using interpolated radiosonde temperatures at times nearly coincident with the ITPR soundings. It was found that mean differences between the two data sets were as small as 1.3 C near 500 mb and as large as 2.9 C near the tropopause. The differences between ITPR and radiosonde temperatures at constant pressure levels were sufficient to induce significant differences in the horizontal temperature gradient. Cross sections of geostrophic wind along the orbital tracks were developed using a thermal wind buildup based on the ITPR temperature data and the radiosonde temperature data. Differences between the radiosonde and ITPR geostrophic winds could be explained on the basis of differences in the ITPR and radiosonde temperature gradients.

  4. Association between empirically derived dietary patterns with blood lipids, fasting blood glucose and blood pressure in adults - the India migration study.

    OpenAIRE

    Shridhar, K; Satija, A; Dhillon, PK; Agrawal, S; Gupta, R; Bowen, L; Kinra, S; Bharathi, AV; Prabhakaran, D; Srinath Reddy, K; Ebrahim, S; Indian Migration Study group,

    2018-01-01

    Dietary patterns (DPs) in India are heterogenous. To date, data on association of indigenous DPs in India with risk factors of nutrition-related noncommunicable diseases (cardiovascular disease and diabetes), leading causes of premature death and disability, are limited. We aimed to evaluate the associations of empirically-derived DPs with blood lipids, fasting glucose and blood pressure levels in an adult Indian population recruited across four geographical regions of India. We used cross-se...

  5. Association between empirically derived dietary patterns with blood lipids, fasting blood glucose and blood pressure in adults - the India migration study

    OpenAIRE

    Shridhar, Krithiga; Satija, Ambika; Dhillon, Preet K.; Agrawal, Sutapa; Gupta, Ruby; Bowen, Liza; Kinra, Sanjay; Bharathi, A. V.; Prabhakaran, D.; Srinath Reddy, K.; Ebrahim, Shah

    2018-01-01

    Background Dietary patterns (DPs) in India are heterogenous. To date, data on association of indigenous DPs in India with risk factors of nutrition-related noncommunicable diseases (cardiovascular disease and diabetes), leading causes of premature death and disability, are limited. We aimed to evaluate the associations of empirically-derived DPs with blood lipids, fasting glucose and blood pressure levels in an adult Indian population recruited across four geographical regions of India. Metho...

  6. Wind Turbine Radar Cross Section

    Directory of Open Access Journals (Sweden)

    David Jenn

    2012-01-01

    Full Text Available The radar cross section (RCS of a wind turbine is a figure of merit for assessing its effect on the performance of electronic systems. In this paper, the fundamental equations for estimating the wind turbine clutter signal in radar and communication systems are presented. Methods of RCS prediction are summarized, citing their advantages and disadvantages. Bistatic and monostatic RCS patterns for two wind turbine configurations, a horizontal axis three-blade design and a vertical axis helical design, are shown. The unique electromagnetic scattering features, the effect of materials, and methods of mitigating wind turbine clutter are also discussed.

  7. Damping Wind and Wave Loads on a Floating Wind Turbine

    DEFF Research Database (Denmark)

    Christiansen, Søren; Bak, Thomas; Knudsen, Torben

    2013-01-01

    Offshore wind energy capitalizes on the higher and less turbulent wind speeds at sea. To enable deployment of wind turbines in deep-water locations, structures are being explored, where wind turbines are placed on a floating platform. This combined structure presents a new control problem, due...... to the partly unconstrained movement of the platform and ocean wave excitation. If this additional complexity is not dealt with properly, this may lead to a significant increase in the structural loads and, potentially, instability of the controlled system. In this paper, the wave excitation is investigated......, and we show the influence that both wind speed, wave frequencies and misalignment between wind and waves have on the system dynamics. A new control model is derived that extends standard turbine models to include the hydrodynamics, additional platform degrees of freedom, the platform mooring system...

  8. SAT-WIND project. Final report[Winds from satellites for offshore and coastal wind energy mapping and wind-indexing

    Energy Technology Data Exchange (ETDEWEB)

    Hasager, C.B.; Astrup, P.; Nielsen, M. (and others)

    2007-04-15

    The SAT-WIND project 'Winds from satellites for offshore and coastal wind energy mapping and wind-indexing' was a research project funded by STVF/DSF in the years 2003 to 2006 (Sagsnr. 2058-03-0006). The goal of the project was to verify the applicability of satellite wind maps derived from passive microwave, altimeter, scatterometer and imaging Synthetic Aperture Radar (SAR) technologies for wind energy tools for wind resources and wind-indexing. The study area was the Danish Seas including the North Sea, interior seas and the Baltic Sea. The report describes technical details on the satellite data sources including: 1) passive microwave (SSM/I, AMSR-E), 2) passive microwave polarimetric (WindSat), 3) scatterometer (ERS, QuikSCAT, Midori-2 and NSCAT), 4) altimeter (ERS, Topex, Poseidon, GFO-1, Jason-1), 5) SAR (ERS, Envisat). The SAR wind maps were treated in S-WAsP developed by Risoe National Laboratory in cooperation with GRAS A/S in the innovative project SAT-WIND-SMV (Sagsnr. 2104-05-0084) in the years 2005 and 2006 in parallel with SAT-WIND. The results from the SAT-WIND project are presented. These include ocean wind statistics, offshore wind resource estimates and comparison results for wind-indexing. (au)

  9. Dietary patterns derived from principal component- and k-means cluster analysis: long-term association with coronary heart disease and stroke.

    Science.gov (United States)

    Stricker, M D; Onland-Moret, N C; Boer, J M A; van der Schouw, Y T; Verschuren, W M M; May, A M; Peeters, P H M; Beulens, J W J

    2013-03-01

    Studies comparing dietary patterns derived from different a posteriori methods in view of predicting disease risk are scarce. We aimed to explore differences between dietary patterns derived from principal component- (PCA) and k-means cluster analysis (KCA) in relation to their food group composition and ability to predict CHD and stroke risk. The study was conducted in the EPIC-NL cohort that consists of 40,011 men and women. Baseline dietary intake was measured using a validated food-frequency questionnaire. Food items were consolidated into 31 food groups. Occurrence of CHD and stroke was assessed through linkage with registries. After 13 years of follow-up, 1,843 CHD and 588 stroke cases were documented. Both PCA and KCA extracted a prudent pattern (high intakes of fish, high-fiber products, raw vegetables, wine) and a western pattern (high consumption of French fries, fast food, low-fiber products, other alcoholic drinks, soft drinks with sugar) with small variation between components and clusters. The prudent component was associated with a reduced risk of CHD (HR for extreme quartiles: 0.87; 95%-CI: 0.75-1.00) and stroke (0.68; 0.53-0.88). The western component was not related to any outcome. The prudent cluster was related with a lower risk of CHD (0.91; 0.82-1.00) and stroke (0.79; 0.67-0.94) compared to the western cluster. PCA and KCA found similar underlying patterns with comparable associations with CHD and stroke risk. A prudent pattern reduced the risk of CHD and stroke. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Wide Area Wind Field Monitoring Status & Results

    Energy Technology Data Exchange (ETDEWEB)

    Alan Marchant; Jed Simmons

    2011-09-30

    Volume-scanning elastic has been investigated as a means to derive 3D dynamic wind fields for characterization and monitoring of wind energy sites. An eye-safe volume-scanning lidar system was adapted for volume imaging of aerosol concentrations out to a range of 300m. Reformatting of the lidar data as dynamic volume images was successfully demonstrated. A practical method for deriving 3D wind fields from dynamic volume imagery was identified and demonstrated. However, the natural phenomenology was found to provide insufficient aerosol features for reliable wind sensing. The results of this study may be applicable to wind field measurement using injected aerosol tracers.

  11. Estimation of wind characteristics at potential wind energy conversion sites

    Energy Technology Data Exchange (ETDEWEB)

    1979-10-01

    A practical method has been developed and applied to the problem of determining wind characteristics at candidate wind energy conversion sites where there are no available historical data. The method uses a mass consistent wind flow model (called COMPLEX) to interpolate between stations where wind data are available. The COMPLEX model incorporates the effects of terrain features and airflow. The key to the practical application of COMPLEX to the derivation of wind statistics is the model's linearity. This allows the input data sets to be resolved into orthogonal components along the set of eigenvectors of the covariance matrix. The solution for each eigenvector is determined with COMPLEX; the hourly interpolated winds are then formed from linear combinations of these solutions. The procedure requires: acquisition and merger of wind data from three to five stations, application of COMPLEX to each of the seven to 11 (depending on the number of stations for which wind data are available) eigenvectors, reconstruction of the hourly interpolated winds at the site from the eigenvector solutions, and finally, estimating the wind characteristics from the simulated hourly values. The report describes the methodology and the underlying theory. Possible improvements to the procedure are also discussed.

  12. Aeroservoelasticity of wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Skovmose Kallesoee, B.

    2007-12-14

    This thesis deals with the fundamental aeroelastic interaction between structural motion, Pitch action and control for a wind turbine blade. As wind turbines become larger, the interaction between pitch action, blade motion, aerodynamic forces, and control become even more important to understand and address. The main contribution of this thesis is the development of an aeroelastic blade model which on the one hand includes the important effects of steady state blade deformation, gravity and pitch action, and on the other it is transparent, suitable for analytical analysis and parameter studies, and furthermore linear and therefore suitable for control design. The development of the primary aeroelastic blade model is divided into four steps: 1) Nonlinear partial differential equations (PDEs) of structural blade motion are derived together with equations of pitch action and rotor speed; the individual terms in these equations are discussed and given physical interpretations; 2) Steady state blade deformation and induced velocities are computed by combining the PDEs with a steady state aerodynamic model; 3) Aeroelastic modes of motion are computed by combining the linearized PDEs with a linear unsteady aerodynamic model; this model is used to analyze how blade deformation effects the modes of motion; and 4) the linear aeroelastic blade model is derived by a modal expansion of the linearized PDEs combined with a linear unsteady aerodynamic model. The aeroelastic blade model has many similarities to a 2D blade section model, and it can be used instead of this in many applications, giving a transparent connection to a real wind turbine blade. In this work the aeroelastic blade model is used to analyze interaction between pitch action, blade motion and wind speed variations. Furthermore the model is used to develop a state estimator for estimating the wind speed and wind shear, and to suggest a load reducing controller. The state estimator estimates the wind shear very

  13. Objective analysis of surface wind regimes over Israel using self-organizing maps

    Science.gov (United States)

    Berkovic, Sigalit

    2017-04-01

    The surface wind across Israel is studied using the method of Self Organizing maps (SOMs). Emphasis is made on identifying the characteristic diurnal patterns at the synoptic hours during the winter months. The investigation is made by analyzing surface wind measurements from 53 Israel Meteorological Service (IMS) stations during 2006-2012. The relation between surface wind patterns and synoptic variables (temperature, specific humidity, geopotential height and synoptic wind) is obtained from calculation of averages of these variables according to the surface wind SOMs classification. The synoptic data is derived from ECMWF ERA40 data. Under winter lows the flow over Israel is westerly with high steadiness (>0.8) and intensity (4-10 m/s). Under winter highs the flow over northern Israel is easterly with high steadiness (>0.8) and intensity. Wind intensity is proportional to the pressure gradient. Under transitional pressure gradients, the flow is determined by the local topography and the diurnal heating, its steadiness is relatively low and its intensity weakens. The wind regimes are in agreement with previous subjective and semi-objective classification studies of surface flow under the frequent synoptic classes. The ability to reconstruct subjective knowledge by an objective algorithm is crucial for future statistical climatological analysis and applications over Israel.

  14. Confidence intervals for annual wind power production******

    Directory of Open Access Journals (Sweden)

    Bensoussan Alain

    2014-01-01

    Full Text Available Wind power is an intermittent resource due to wind speed intermittency. However wind speed can be described as a stochastic process with short memory. This allows us to derive a central limit theorem for the annual or pluri-annual wind power production and then get quantiles of the wind power production for one, ten or twenty years future periods. On the one hand, the interquantile spread offers a measurement of the intrinsic uncertainties of wind power production. On the other hand, different quantiles with different periods of time are used by financial institutions to quantify the financial risk of the wind turbine. Our method is then applied to real datasets corresponding to a French wind turbine. Since confidence intervals can be enhanced by taking into account seasonality, we present some tools for change point analysis on wind series.

  15. Coastal Ohio Wind Project

    Energy Technology Data Exchange (ETDEWEB)

    Gorsevski, Peter [Bowling Green State Univ., OH (United States); Afjeh, Abdollah [Univ. of Toledo, OH (United States); Jamali, Mohsin [Univ. of Toledo, OH (United States); Bingman, Verner [Bowling Green State Univ., OH (United States)

    2014-04-04

    reduced the wake size and enhanced the vortices in the flow downstream of the turbine-tower compared with the tower alone case. Mean and rms velocity distributions from hot wire anemometer data confirmed that in a downwind configuration, the wake of the tower dominates the flow, thus the flow fields of a tower alone and tower-turbine combinations are nearly the same. For the upwind configuration, the mean velocity shows a narrowing of the wake compared with the tower alone case. The downwind configuration wake persisted longer than that of an upwind configuration; however, it was not possible to quantify this difference because of the size limitation of the wind tunnel downstream of the test section. The water tunnel studies demonstrated that the scale model studies could be used to adequately produce accurate motions to model the motions of a wind turbine platform subject to large waves. It was found that the important factors that affect the platform is whether the platform is submerged or surface piercing. In the former, the loads on the platform will be relatively reduced whereas in the latter case, the structure pierces the wave free surface and gains stiffness and stability. The other important element that affects the movement of the platform is depth of the sea in which the wind turbine will be installed. Furthermore, the wildlife biology component evaluated migratory patterns by different monitoring systems consisting of marine radar, thermal IR camera and acoustic recorders. The types of radar used in the project are weather surveillance radar and marine radar. The weather surveillance radar (1988 Doppler), also known as Next Generation Radar (NEXRAD), provides a network of weather stations in the US. Data generated from this network were used to understand general migratory patterns, migratory stopover habitats, and other patterns caused by the effects of weather conditions. At a local scale our marine radar was used to complement the datasets from NEXRAD and

  16. Wind models for the NSTS ascent trajectory biasing for wind load alleviation

    Science.gov (United States)

    Smith, O. E.; Adelfang, S. I.; Batts, G. W.

    1990-01-01

    New concepts are presented for aerospace vehicle ascent wind profile biasing. The purpose for wind biasing the ascent trajectory is to provide ascent wind loads relief and thus decrease the probability for launch delays due to wind loads exceeding critical limits. Wind biasing trajectories to the the profile of monthly mean winds have been widely used for this purpose. The wind profile models presented give additional alternatives for wind biased trajectories. They are derived from the properties of the bivariate normal probability function using the available wind statistical parameters for the launch site. The analytical expressions are presented to permit generalizations. Specific examples are given to illustrate the procedures. The wind profile models can be used to establish the ascent trajectory steering commands to guide the vehicle through the first stage. For the National Space Transportation System (NSTS) program these steering commands are called I-loads.

  17. Modern sedimentation patterns in Lake El'gygytgyn, NE Russia, derived from surface sediment and inlet streams samples

    Directory of Open Access Journals (Sweden)

    V. Wennrich

    2013-01-01

    Full Text Available Lake El'gygytgyn/NE Russia holds a continuous 3.58 Ma sediment record, which is regarded as the most long-lasting climate archive of the terrestrial Arctic. Based on multi-proxy geochemical, mineralogical, and granulometric analyses of surface sediment, inlet stream and bedrock samples, supplemented by statistical methods, major processes influencing the modern sedimentation in the lake were investigated. Grain-size parameters and chemical elements linked to the input of feldspars from acidic bedrock indicate a wind-induced two-cell current system as major driver of sediment transport and accumulation processes in Lake El'gygytgyn. The distribution of mafic rock related elements in the sediment on the lake floor can be traced back to the input of weathering products of basaltic rocks in the catchment. Obvious similarities in the spatial variability of manganese and heavy metals indicate sorption or co-precipitation of these elements with Fe and Mn hydroxides and oxides. But the similar distribution of organic matter and clay contents might also point to a fixation to organic components and clay minerals. An enrichment of mercury in the inlet streams might be indicative of neotectonic activity around the lake. The results of this study add to the fundamental knowledge of the modern lake processes of Lake El'gygytgyn and its lake-catchment interactions, and thus, yield crucial insights for the interpretation of paleo-data from this unique archive.

  18. Monitoring the differentiation and migration patterns of neural cells derived from human embryonic stem cells using a microfluidic culture system.

    Science.gov (United States)

    Lee, Nayeon; Park, Jae Woo; Kim, Hyung Joon; Yeon, Ju Hun; Kwon, Jihye; Ko, Jung Jae; Oh, Seung-Hun; Kim, Hyun Sook; Kim, Aeri; Han, Baek Soo; Lee, Sang Chul; Jeon, Noo Li; Song, Jihwan

    2014-06-01

    Microfluidics can provide unique experimental tools to visualize the development of neural structures within a microscale device, which is followed by guidance of neurite growth in the axonal isolation compartment. We utilized microfluidics technology to monitor the differentiation and migration of neural cells derived from human embryonic stem cells (hESCs). We co-cultured hESCs with PA6 stromal cells, and isolated neural rosette-like structures, which subsequently formed neurospheres in suspension culture. Tuj1-positive neural cells, but not nestin-positive neural precursor cells (NPCs), were able to enter the microfluidics grooves (microchannels), suggesting that neural cell-migratory capacity was dependent upon neuronal differentiation stage. We also showed that bundles of axons formed and extended into the microchannels. Taken together, these results demonstrated that microfluidics technology can provide useful tools to study neurite outgrowth and axon guidance of neural cells, which are derived from human embryonic stem cells.

  19. Spatial and temporal patterns of xylem sap pH derived from stems and twigs of Populus deltoides L.

    Science.gov (United States)

    Doug Aubrey; Justin Boyles; Laura Krysinsky; Robert Teskey

    2011-01-01

    Xylem sap pH (pHX) is critical in determining the quantity of inorganic carbon dissolved in xylem solution from gaseous [CO2] measurements. Studies of internal carbon transport have generally assumed that pHX derived from stems and twigs is similar and that pHX remains constant through time; however, no empirical studies have investigated these assumptions. If any of...

  20. Identification of a consistent pattern of mutations in neurovirulent variants derived from the sabin vaccine strain of poliovirus type 2.

    OpenAIRE

    Equestre, M; Genovese, D; Cavalieri, F; Fiore, L; Santoro, R; Perez Bercoff, R

    1991-01-01

    Complete nucleotide sequencing of the RNAs of two unrelated neurovirulent isolates of Sabin-related poliovirus type 2 revealed that two nucleotides and one amino acid (amino acid 143 in the major capsid protein VP1) consistently departed from the sequences of the nonneurovirulent poliovirus type 2 712 and Sabin vaccine strains. This pattern of mutation appeared to be a feature common to all neurovirulent variants of poliovirus type 2.

  1. Wind energy

    CERN Document Server

    Woll, Kris

    2016-01-01

    Across the country, huge open spaces are covered in gently turning wind turbines. In Wind Energy, explore how these machines generate electricity, learn about the history of wind power, and discover the latest advances in the field. Easy-to-read text, vivid images, and helpful back matter give readers a clear look at this subject. Features include a table of contents, infographics, a glossary, additional resources, and an index. Aligned to Common Core Standards and correlated to state standards. Core Library is an imprint of Abdo Publishing, a division of ABDO.

  2. Addressing Spatial Variability of Surface-Layer Wind with Long-Range WindScanners

    DEFF Research Database (Denmark)

    Berg, Jacob; Vasiljevic, Nikola; Kelly, Mark C.

    2015-01-01

    This paper presents an analysis of mean wind measurements from a coordinated system of long-range WindScanners. From individual scan patterns the mean wind field was reconstructed over a large area, and hence it highlights the spatial variability. From comparison with sonic anemometers, the quality...

  3. Quarter-Century Offshore Winds from SSM/I and WRF in the North Sea and South China Sea

    Directory of Open Access Journals (Sweden)

    Charlotte Bay Hasager

    2016-09-01

    Full Text Available We study the wind climate and its long-term variability in the North Sea and South China Sea, areas relevant for offshore wind energy development, using satellite-based wind data, because very few reliable long-term in-situ sea surface wind observations are available. The Special Sensor Microwave Imager (SSM/I ocean winds extrapolated from 10 m to 100 m using the Charnock relationship and the logarithmic profile method are compared to Weather Research and Forecasting (WRF model results in both seas and to in-situ observations in the North Sea. The mean wind speed from SSM/I and WRF differ only by 0.1 m/s at Fino1 in the North Sea, while west of Hainan in the South China Sea the difference is 1.0 m/s. Linear regression between SSM/I and WRF winds at 100 m show correlation coefficients squared of 0.75 and 0.67, standard deviation of 1.67 m/s and 1.41 m/s, and mean difference of −0.12 m/s and 0.83 m/s for Fino1 and Hainan, respectively. The WRF-derived winds overestimate the values in the South China Sea. The inter-annual wind speed variability is estimated as 4.6% and 4.4% based on SSM/I at Fino1 and Hainan, respectively. We find significant changes in the seasonal wind pattern at Fino1 with springtime winds arriving one month earlier from 1988 to 2013 and higher winds in June; no yearly trend in wind speed is observed in the two seas.

  4. Wind turbine noise diagnostics

    International Nuclear Information System (INIS)

    Richarz, W.; Richarz, H.

    2009-01-01

    This presentation proposed a self-consistent model for broad-band noise emitted from modern wind turbines. The simple source model was consistent with the physics of sound generation and considered the unique features of wind turbines. Although the acoustics of wind turbines are similar to those of conventional propellers, the dimensions of wind turbines pose unique challenges in diagnosing noise emission. The general features of the sound field were deduced. Source motion and source directivity appear to be responsible for amplitude variations. The amplitude modulation is likely to make wind-turbine noise more audible, and may be partly responsible for annoyance that has been reported in the literature. Acoustic array data suggests that broad-band noise is emitted predominantly during the downward sweep of each rotor blade. Source motion and source directivity account for the observed pattern. Rotor-tower interaction effects are of lesser importance. Predicted amplitude modulation ranges from 1 dB to 6dB. 2 refs., 9 figs.

  5. Molecular recognition of AT-DNA sequences by the induced CD pattern of dibenzotetraaza[14]annulene (DBTAA)-adenine derivatives.

    Science.gov (United States)

    Stojković, Marijana Radić; Skugor, Marko; Dudek, Lukasz; Grolik, Jarosław; Eilmes, Julita; Piantanida, Ivo

    2014-01-01

    An investigation of the interactions of two novel and several known DBTAA-adenine conjugates with double-stranded DNA and RNA has revealed the DNA/RNA groove as the dominant binding site, which is in contrast to the majority of previously studied DBTAA analogues (DNA/RNA intercalators). Only DBTAA-propyladenine conjugates revealed the molecular recognition of AT-DNA by an ICD band pattern > 300 nm, whereas significant ICD bands did not appear for other ds-DNA/RNA. A structure-activity relation for the studied series of compounds showed that the essential structural features for the ICD recognition are a) the presence of DNA-binding appendages (adenine side chain and positively charged side chain) on both DBTAA side chains, and b) the presence of a short propyl linker, which does not support intramolecular aromatic stacking between DBTAA and adenine. The observed AT-DNA-ICD pattern differs from previously reported ss-DNA (poly dT) ICD recognition by a strong negative ICD band at 350 nm, which allows for the dynamic differentiation between ss-DNA (poly dT) and coupled ds-AT-DNA.

  6. World Wind

    Data.gov (United States)

    National Aeronautics and Space Administration — World Wind allows any user to zoom from satellite altitude into any place on Earth, leveraging high resolution LandSat imagery and SRTM elevation data to experience...

  7. Flatback airfoil wind tunnel experiment.

    Energy Technology Data Exchange (ETDEWEB)

    Mayda, Edward A. (University of California, Davis, CA); van Dam, C.P. (University of California, Davis, CA); Chao, David D. (University of California, Davis, CA); Berg, Dale E.

    2008-04-01

    A computational fluid dynamics study of thick wind turbine section shapes in the test section of the UC Davis wind tunnel at a chord Reynolds number of one million is presented. The goals of this study are to validate standard wind tunnel wall corrections for high solid blockage conditions and to reaffirm the favorable effect of a blunt trailing edge or flatback on the performance characteristics of a representative thick airfoil shape prior to building the wind tunnel models and conducting the experiment. The numerical simulations prove the standard wind tunnel corrections to be largely valid for the proposed test of 40% maximum thickness to chord ratio airfoils at a solid blockage ratio of 10%. Comparison of the computed lift characteristics of a sharp trailing edge baseline airfoil and derived flatback airfoils reaffirms the earlier observed trend of reduced sensitivity to surface contamination with increasing trailing edge thickness.

  8. Satellite-Derived Photic Depth on the Great Barrier Reef: Spatio-Temporal Patterns of Water Clarity

    Directory of Open Access Journals (Sweden)

    Scarla Weeks

    2012-11-01

    Full Text Available Detecting changes to the transparency of the water column is critical for understanding the responses of marine organisms, such as corals, to light availability. Long-term patterns in water transparency determine geographical and depth distributions, while acute reductions cause short-term stress, potentially mortality and may increase the organisms’ vulnerability to other environmental stressors. Here, we investigated the optimal, operational algorithm for light attenuation through the water column across the scale of the Great Barrier Reef (GBR, Australia. We implemented and tested a quasi-analytical algorithm to determine the photic depth in GBR waters and matched regional Secchi depth (ZSD data to MODIS-Aqua (2002–2010 and SeaWiFS (1997–2010 satellite data. The results of the in situ ZSD/satellite data matchup showed a simple bias offset between the in situ and satellite retrievals. Using a Type II linear regression of log-transformed satellite and in situ data, we estimated ZSD and implemented the validated ZSD algorithm to generate a decadal satellite time series (2002–2012 for the GBR. Water clarity varied significantly in space and time. Seasonal effects were distinct, with lower values during the austral summer, most likely due to river runoff and increased vertical mixing, and a decline in water clarity between 2008–2012, reflecting a prevailing La Niña weather pattern. The decline in water clarity was most pronounced in the inshore area, where a significant decrease in mean inner shelf ZSD of 2.1 m (from 8.3 m to 6.2 m occurred over the decade. Empirical Orthogonal Function Analysis determined the dominance of Mode 1 (51.3%, with the greatest variation in water clarity along the mid-shelf, reflecting the strong influence of oceanic intrusions on the spatio-temporal patterns of water clarity. The newly developed photic depth product has many potential applications for the GBR from water quality monitoring to analyses of

  9. 78 FR 29364 - Exelon Corporation, Exelon Wind 1, LLC, Exelon Wind 2, LLC, Exelon Wind 3, LLC, Exelon Wind 4...

    Science.gov (United States)

    2013-05-20

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

  10. DERIVING USER ACCESS PATTERNS AND MINING WEB COMMUNITY WITH WEB-LOG DATA FOR PREDICTING USER SESSIONS WITH PAJEK

    Directory of Open Access Journals (Sweden)

    S. Balaji

    2012-10-01

    Full Text Available Web logs are a young and dynamic media type. Due to the intrinsic relationship among Web objects and the deficiency of a uniform schema of web documents, Web community mining has become significant area for Web data management and analysis. The research of Web communities extents a number of research domains. In this paper an ontological model has been present with some recent studies on this topic, which cover finding relevant Web pages based on linkage information, discovering user access patterns through analyzing Web log files from Web data. A simulation has been created with the academic website crawled data. The simulation is done in JAVA and ORACLE environment. Results show that prediction of user session could give us plenty of vital information for the Business Intelligence. Search Engine Optimization could also use these potential results which are discussed in the paper in detail.

  11. Gene expression patterns related to osteogenic differentiation of bone marrow-derived mesenchymal stem cells during ex vivo expansion.

    Science.gov (United States)

    Granchi, Donatella; Ochoa, Gorka; Leonardi, Elisa; Devescovi, Valentina; Baglìo, Serena Rubina; Osaba, Lourdes; Baldini, Nicola; Ciapetti, Gabriela

    2010-06-01

    Bone marrow is commonly used as a source of adult multipotent mesenchymal stem cells (MSCs), defined for their ability to differentiate in vitro into multiple lineages. The ex vivo-expanded MSCs are currently being evaluated as a strategy for the restoration of function in damaged skeletal tissue, both in cell therapy and tissue engineering applications. The aim of this study was to define gene expression patterns underlying the differentiation of MSCs into mature osteoblasts during the expansion in vitro, and to explore a variety of cell functions that cannot be easily evaluated using morphological, cytochemical, and biochemical assays. Cell cultures were obtained from bone marrow samples of six individuals undergoing total hip replacement, and a large-scale transcriptome analysis, using Affymetrix HG-U133A Plus 2.0 array (Affymetrix((R)), Santa Clara, CA), was performed at the occurrence of specific events, including the appearance of MSC surface markers, formation of colonies, and deposition of mineral nodules. We focused our attention on 213 differentially upregulated genes, some belonging to well-known pathways and some having one or more Gene Ontology annotations related to bone cell biology, including angiogenesis, bone-related genes, cell communication, development and morphogenesis, transforming growth factor-beta signaling, and Wnt signaling. Twenty-nine genes, whose role in bone cell pathophysiology has not been described yet, were found. In conclusion, gene expression patterns that characterize the early, intermediate, and late phases of the osteogenic differentiation process of ex vivo-expanded MSCs were defined. These signatures represent a useful tool to monitor the osteogenic process, and to analyze a broad spectrum of functions of MSCs cultured on scaffolds, especially when the constructs are conceived for releasing growth factors or other signals to promote bone regeneration.

  12. 3D WindScanner lidar measurements of wind and turbulence around wind turbines, buildings and bridges

    Science.gov (United States)

    Mikkelsen, T.; Sjöholm, M.; Angelou, N.; Mann, J.

    2017-12-01

    WindScanner is a distributed research infrastructure developed at DTU with the participation of a number of European countries. The research infrastructure consists of a mobile technically advanced facility for remote measurement of wind and turbulence in 3D. The WindScanners provide coordinated measurements of the entire wind and turbulence fields, of all three wind components scanned in 3D space. Although primarily developed for research related to on- and offshore wind turbines and wind farms, the facility is also well suited for scanning turbulent wind fields around buildings, bridges, aviation structures and of flow in urban environments. The mobile WindScanner facility enables 3D scanning of wind and turbulence fields in full scale within the atmospheric boundary layer at ranges from 10 meters to 5 (10) kilometers. Measurements of turbulent coherent structures are applied for investigation of flow pattern and dynamical loads from turbines, building structures and bridges and in relation to optimization of the location of, for example, wind farms and suspension bridges. This paper presents our achievements to date and reviews briefly the state-of-the-art of the WindScanner measurement technology with examples of uses for wind engineering applications.

  13. Improved diagnostic model for estimating wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Endlich, R.M.; Lee, J.D.

    1983-03-01

    Because wind data are available only at scattered locations, a quantitative method is needed to estimate the wind resource at specific sites where wind energy generation may be economically feasible. This report describes a computer model that makes such estimates. The model uses standard weather reports and terrain heights in deriving wind estimates; the method of computation has been changed from what has been used previously. The performance of the current model is compared with that of the earlier version at three sites; estimates of wind energy at four new sites are also presented.

  14. Prediction models for wind speed at turbine locations in a wind farm

    DEFF Research Database (Denmark)

    Knudsen, Torben; Bak, Thomas; Soltani, Mohsen

    2011-01-01

    turbulence models. The esti- mator includes a nonlinear time varying wind speed model, which compared with literature results in an adaptive filter. Given the estimated effective wind speed, it is possible to establish wind speed prediction models by system identification. As the prediction models are based...... manifested through the wind field is hence required. This paper develops models for this relationship. The result is based on two new contributions: the first is related to the estimation of effective wind speeds, which serves as a basis for the second contribution to wind speed prediction models. Based...... on standard turbine measurements such as rotor speed and power produced, an effective wind speed, which represents the wind field averaged over the rotor disc, is derived. The effective wind speed estimator is based on a continuous–discrete extended Kalman filter that takes advantage of nonlinear time varying...

  15. Peak Wind Tool for General Forecasting

    Science.gov (United States)

    Barrett, Joe H., III

    2010-01-01

    again by six years, from October 1996 to April 2002, by interpolating 1000-ft sounding data to 100-ft increments. The Phase II developmental data set included observations for the cool season months of October 1996 to February 2007. The AMU calculated 68 candidate predictors from the XMR soundings, to include 19 stability parameters, 48 wind speed parameters and one wind shear parameter. Each day in the data set was stratified by synoptic weather pattern, low-level wind direction, precipitation and Richardson Number, for a total of 60 stratification methods. Linear regression equations, using the 68 predictors and 60 stratification methods, were created for the tool's three forecast parameters: the highest peak wind speed of the day (PWSD), 5-minute average speed at the same time (A WSD), and timing of the PWSD. For PWSD and A WSD, 30 Phase II methods were selected for evaluation in the verification data set. For timing of the PWSD, 12 Phase\\I methods were selected for evaluation. The verification data set contained observations for the cool season months of March 2007 to April 2009. The data set was used to compare the Phase I and II forecast methods to climatology, model forecast winds and wind advisories issued by the 45 WS. The model forecast winds were derived from the 0000 and 1200 UTC runs of the 12-km North American Mesoscale (MesoNAM) model. The forecast methods that performed the best in the verification data set were selected for the Phase II version of the tool. For PWSD and A WSD, linear regression equations based on MesoNAM forecasts performed significantly better than the Phase I and II methods. For timing of the PWSD, none of the methods performed significantly bener than climatology. The AMU then developed the Microsoft Excel and MIDDS GUls. The GUIs display the forecasts for PWSD, AWSD and the probability the PWSD will meet or exceed 25 kt, 35 kt and 50 kt. Since none of the prediction methods for timing of the PWSD performed significantly better

  16. Evolutionary patterns of carbohydrate transport and metabolism in Halomonas boliviensis as derived from its genome sequence: influences on polyester production.

    Science.gov (United States)

    Guzmán, Daniel; Balderrama-Subieta, Andrea; Cardona-Ortuño, Carla; Guevara-Martínez, Mónica; Callisaya-Quispe, Nataly; Quillaguamán, Jorge

    2012-04-17

    Halomonas boliviensis is a halophilic bacterium that is included in the γ-Proteobacteria sub-group, and is able to assimilate different types of carbohydrates. H. boliviensis is also able to produce poly(3-hydroxybutyrate) (PHB) in high yields using glucose as the carbon precursor. Accumulation of PHB by microorganisms is induced by excess of intracellular NADH.The genome sequences and organization in microorganisms should be the result of evolution and adaptation influenced by mutation, gene duplication, horizontal gen transfer (HGT) and recombination. Furthermore, the nearly neutral theory of evolution sustains that genetic modification of DNA could be neutral or selected, albeit most mutations should be at the border between neutrality and selection, i.e. slightly deleterious base substitutions in DNA are followed by a slightly advantageous substitutions. This article reports the genome sequence of H. boliviensis. The chromosome size of H. boliviensis was 4 119 979 bp, and contained 3 863 genes. A total of 160 genes of H. boliviensis were related to carbohydrate transport and metabolism, and were organized as: 70 genes for metabolism of carbohydrates; 47 genes for ABC transport systems and 43 genes for TRAP-type C4-dicarboxylate transport systems. Protein sequences of H. boliviensis related to carbohydrate transport and metabolism were selected from clusters of orthologous proteins (COGs). Similar proteins derived from the genome sequences of other 41 archaea and 59 bacteria were used as reference. We found that most of the 160 genes in H. boliviensis, c.a. 44%, were obtained from other bacteria by horizontal gene transfer, while 13% of the genes were acquired from haloarchaea and thermophilic archaea, only 34% of the genes evolved among Proteobacteria and the remaining genes encoded proteins that did not cluster with any of the proteins obtained from the reference strains. Furthermore, the diversity of the enzymes derived from these genes led to polymorphism

  17. Evolutionary patterns of carbohydrate transport and metabolism in Halomonas boliviensis as derived from its genome sequence: influences on polyester production

    Science.gov (United States)

    2012-01-01

    Background Halomonas boliviensis is a halophilic bacterium that is included in the γ-Proteobacteria sub-group, and is able to assimilate different types of carbohydrates. H. boliviensis is also able to produce poly(3-hydroxybutyrate) (PHB) in high yields using glucose as the carbon precursor. Accumulation of PHB by microorganisms is induced by excess of intracellular NADH. The genome sequences and organization in microorganisms should be the result of evolution and adaptation influenced by mutation, gene duplication, horizontal gen transfer (HGT) and recombination. Furthermore, the nearly neutral theory of evolution sustains that genetic modification of DNA could be neutral or selected, albeit most mutations should be at the border between neutrality and selection, i.e. slightly deleterious base substitutions in DNA are followed by a slightly advantageous substitutions. Results This article reports the genome sequence of H. boliviensis. The chromosome size of H. boliviensis was 4 119 979 bp, and contained 3 863 genes. A total of 160 genes of H. boliviensis were related to carbohydrate transport and metabolism, and were organized as: 70 genes for metabolism of carbohydrates; 47 genes for ABC transport systems and 43 genes for TRAP-type C4-dicarboxylate transport systems. Protein sequences of H. boliviensis related to carbohydrate transport and metabolism were selected from clusters of orthologous proteins (COGs). Similar proteins derived from the genome sequences of other 41 archaea and 59 bacteria were used as reference. We found that most of the 160 genes in H. boliviensis, c.a. 44%, were obtained from other bacteria by horizontal gene transfer, while 13% of the genes were acquired from haloarchaea and thermophilic archaea, only 34% of the genes evolved among Proteobacteria and the remaining genes encoded proteins that did not cluster with any of the proteins obtained from the reference strains. Furthermore, the diversity of the enzymes derived from these genes

  18. Novel adjuvant based on a proteoliposome-derived cochleate structure containing native lipopolysaccharide as a pathogen-associated molecular pattern.

    Science.gov (United States)

    Pérez, Oliver; Bracho, Gustavo; Lastre, Miriam; Mora, Nestor; del Campo, Judith; Gil, Danay; Zayas, Caridad; Acevedo, Reinaldo; González, Domingo; López, José A; Taboada, Carlos; Turtle, Cameron; Solis, Rosa L

    2004-12-01

    Proteoliposomes (PL) from Neisseria meningitidis B have been widely used as a core antigen for antimeningococcal vaccination. PL contain major outer membrane proteins, LPS and phospholipids, and they induce a strong Th1 immune response, but they have low stability in solution. Attending to the need for new vaccine adjuvants, we developed a highly stable cochleate structure (CS) from PL using a technology that allows easy incorporation of new antigens. We explored the ability of PLCS to activate the immune system and its possible application as an adjuvant for parenteral and mucosal routes. Our results showed that PLCS were able to upregulate the expression of MHC class II and costimulatory molecules on human dendritic cells, as well as being able to stimulate the production of soluble mediators of a Th1 response, such as IL-12 and nitric oxide. High levels of anti-PL IgG were detected in serum after i.m. or mucosal (oral and nasal) administration, but also anti-PL secretory IgA was produced in saliva following nasal delivery. The immune response polarization to a Th1 pattern was confirmed by the induction of IgG2a antibodies, positive delayed type hypersensitivity reactions, and IFN-gamma production by splenocytes from immunized mice. The adjuvant potential was explored using PLCS containing ovalbumin (Ova). PLCS-Ova was able to elicit a substantial increase in anti-Ova IgG compared with Ova alone. In addition, a significant reduction in lesion size was observed in mice immunized with Leishmania major antigens in PLCS after challenge with virulent protozoa, suggesting at least partial modulation of the Th2 environment induced by this parasite. In conclusion, our results support the use of PLCS as a potent Th1 adjuvant for parenteral and mucosal vaccines.

  19. WIND TURBINES FOR WIND POWER INSTALLATIONS

    Directory of Open Access Journals (Sweden)

    Barladean A.S.

    2008-04-01

    Full Text Available The problem of wind turbine choice for wind power stations is examined in this paper. It is shown by comparison of parameters and characteristics of wind turbines, that for existing modes and speeds of wind in territory of Republic of Moldova it is necessary to use multi-blade small speed rotation wind turbines of fan class.

  20. A comparison of predicted and observed turbulent wind fields present in natural and internal wind park environments

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, N D; Wright, A D

    1991-10-01

    This paper assesses the accuracy of simulated wind fields for both the natural flow and that within a wind park environment. The simulated fields are compared with the observed ones in both the time and frequency domains. Actual measurements of the wind fields and the derived kinematic scaling parameters upwind and downwind of a large San Gorgonio Pass wind park are used. The deviations in the modeled wind field from the observed are discussed. 10 refs., 6 figs., 2 tabs.

  1. Wind turbine

    Science.gov (United States)

    Cheney, Jr., Marvin C.

    1982-01-01

    A wind turbine of the type having an airfoil blade (15) mounted on a flexible beam (20) and a pitch governor (55) which selectively, torsionally twists the flexible beam in response to wind turbine speed thereby setting blade pitch, is provided with a limiter (85) which restricts unwanted pitch change at operating speeds due to torsional creep of the flexible beam. The limiter allows twisting of the beam by the governor under excessive wind velocity conditions to orient the blades in stall pitch positions, thereby preventing overspeed operation of the turbine. In the preferred embodiment, the pitch governor comprises a pendulum (65,70) which responds to changing rotor speed by pivotal movement, the limiter comprising a resilient member (90) which engages an end of the pendulum to restrict further movement thereof, and in turn restrict beam creep and unwanted blade pitch misadjustment.

  2. Short-Term Wind Speed Hybrid Forecasting Model Based on Bias Correcting Study and Its Application

    OpenAIRE

    Mingfei Niu; Shaolong Sun; Jie Wu; Yuanlei Zhang

    2015-01-01

    The accuracy of wind speed forecasting is becoming increasingly important to improve and optimize renewable wind power generation. In particular, reliable short-term wind speed forecasting can enable model predictive control of wind turbines and real-time optimization of wind farm operation. However, due to the strong stochastic nature and dynamic uncertainty of wind speed, the forecasting of wind speed data using different patterns is difficult. This paper proposes a novel combination bias c...

  3. Overview and Meteorological Validation of the Wind Integration National Dataset toolkit

    Energy Technology Data Exchange (ETDEWEB)

    Draxl, C. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hodge, B. M. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Clifton, A. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); McCaa, J. [3TIER by VAisala, Seattle, WA (United States)

    2015-04-13

    The Wind Integration National Dataset (WIND) Toolkit described in this report fulfills these requirements, and constitutes a state-of-the-art national wind resource data set covering the contiguous United States from 2007 to 2013 for use in a variety of next-generation wind integration analyses and wind power planning. The toolkit is a wind resource data set, wind forecast data set, and wind power production and forecast data set derived from the Weather Research and Forecasting (WRF) numerical weather prediction model. WIND Toolkit data are available online for over 116,000 land-based and 10,000 offshore sites representing existing and potential wind facilities.

  4. Spatial dependence in wind and optimal wind power allocation: A copula-based analysis

    International Nuclear Information System (INIS)

    Grothe, Oliver; Schnieders, Julius

    2011-01-01

    The investment decision on the placement of wind turbines is, neglecting legal formalities, mainly driven by the aim to maximize the expected annual energy production of single turbines. The result is a concentration of wind farms at locations with high average wind speed. While this strategy may be optimal for single investors maximizing their own return on investment, the resulting overall allocation of wind turbines may be unfavorable for energy suppliers and the economy because of large fluctuations in the overall wind power output. This paper investigates to what extent optimal allocation of wind farms in Germany can reduce these fluctuations. We analyze stochastic dependencies of wind speed for a large data set of German on- and offshore weather stations and find that these dependencies turn out to be highly nonlinear but constant over time. Using copula theory we determine the value at risk of energy production for given allocation sets of wind farms and derive optimal allocation plans. We find that the optimized allocation of wind farms may substantially stabilize the overall wind energy supply on daily as well as hourly frequency. - Highlights: → Spatial modeling of wind forces in Germany. → A novel way to assess nonlinear dependencies of wind forces by copulas. → Wind turbine allocation by maximizing lower quantiles of energy production. → Optimal results show major increase in reliable part of wind energy.

  5. Wind power

    International Nuclear Information System (INIS)

    2006-06-01

    This road-map proposes by the Group Total aims to inform the public on the wind power. It presents the principles, the technology takes off, its applications and technology focus, the global market trends and the outlooks and Total commitments in the domain. (A.L.B.)

  6. Wind energy

    International Nuclear Information System (INIS)

    Portilla S, L.A.

    1995-01-01

    The wind energy or eolic energy is a consequence of solar energy, the one which is absorbed by the atmosphere and is transformed into energy of movement of large bulks of air. In this process the atmosphere acts as the filter to the solar radiation and demotes the ultraviolet beams that result fatal to life in the Earth. The ionosphere is the most external cap and this is ionized by means of absorption process of ultraviolet radiation arising to the Sun. The atmosphere also acts as a trap to the infrared radiation, it that results from the continual process of energetic degradation. In this way, the interaction between Earth - Atmospheres, is behaved as a great greenhouse, maintaining the constant temperatures, including in the dark nights. Processes as the natural convection (that occur by the thermodynamic phenomenon), equatorial calmness, trade winds and against trade winds and global distribution of the air currents are described. The other hand, techniques as the transformation of the wind into energy and its parameters also are shown

  7. Exposure to nickel, chromium, or cadmium causes distinct changes in the gene expression patterns of a rat liver derived cell line.

    Directory of Open Access Journals (Sweden)

    Matthew G Permenter

    Full Text Available Many heavy metals, including nickel (Ni, cadmium (Cd, and chromium (Cr are toxic industrial chemicals with an exposure risk in both occupational and environmental settings that may cause harmful outcomes. While these substances are known to produce adverse health effects leading to disease or health problems, the detailed mechanisms remain unclear. To elucidate the processes involved in the toxicity of nickel, cadmium, and chromium at the molecular level and to perform a comparative analysis, H4-II-E-C3 rat liver-derived cell lines were treated with soluble salts of each metal using concentrations derived from viability assays, and gene expression patterns were determined with DNA microarrays. We identified both common and unique biological responses to exposure to the three metals. Nickel, cadmium, chromium all induced oxidative stress with both similar and unique genes and pathways responding to this stress. Although all three metals are known to be genotoxic, evidence for DNA damage in our study only exists in response to chromium. Nickel induced a hypoxic response as well as inducing genes involved in chromatin structure, perhaps by replacing iron in key proteins. Cadmium distinctly perturbed genes related to endoplasmic reticulum stress and invoked the unfolded protein response leading to apoptosis. With these studies, we have completed the first gene expression comparative analysis of nickel, cadmium, and chromium in H4-II-E-C3 cells.

  8. Wind Energy Japan

    Energy Technology Data Exchange (ETDEWEB)

    Komatsubara, Kazuyo [Embassy of the Kingdom of the Netherlands, Tokyo (Japan)

    2012-06-15

    An overview is given of wind energy in Japan: Background; Wind Energy in Japan; Japanese Wind Energy Industry; Government Supports; Useful Links; Major Japanese Companies; Profiles of Major Japanese Companies; Major Wind Energy Projects in Japan.

  9. Accelerometer-Derived Pattern of Sedentary and Physical Activity Time in Persons with Mobility Disability: National Health and Nutrition Examination Survey 2003 to 2006.

    Science.gov (United States)

    Manns, Patricia; Ezeugwu, Victor; Armijo-Olivo, Susan; Vallance, Jeff; Healy, Genevieve N

    2015-07-01

    To describe objectively determined sedentary and activity outcomes (volume and pattern) and their associations with cardiometabolic risk biomarkers in individuals with and without mobility disability. Cross-sectional. Population based. Community-dwelling older adults (≥60) living in the United States who were participants in the 2003 to 2004 or 2005 to 2006 National Health and Nutrition Examination Survey. Participants were classified as with or without mobility disability according to responses to self-reported questions about ability to walk, climb stairs, and/or use of ambulatory aids. Accelerometer-derived sedentary and activity variables for volume (time in sedentary (disability. Participants with mobility disability had more sedentary time and less active time than those without. Sedentary bouts were longer and active bouts shorter in those with disability. The total number of sedentary breaks (transitions from sedentary to nonsedentary) differed between groups after adjustment for total sedentary time. Fewer breaks, longer sedentary bouts, and shorter activity bouts were associated with higher average waist circumference regardless of disability status. This study provides rationale for the development and testing of interventions to change the pattern of activity (e.g., include more breaks and longer activity bout durations) in older adults with mobility disability. © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.

  10. Tracking the progression of speciation: variable patterns of introgression across the genome provide insights on the species delimitation between progenitor-derivative spruces (Picea mariana × P. rubens).

    Science.gov (United States)

    de Lafontaine, Guillaume; Prunier, Julien; Gérardi, Sébastien; Bousquet, Jean

    2015-10-01

    The genic species concept implies that while most of the genome can be exchanged somewhat freely between species through introgression, some genomic regions remain impermeable to interspecific gene flow. Hence, interspecific differences can be maintained despite ongoing gene exchange within contact zones. This study assessed the heterogeneous patterns of introgression at gene loci across the hybrid zone of an incipient progenitor-derivative species pair, Picea mariana (black spruce) and Picea rubens (red spruce). The spruce taxa likely diverged in geographic isolation during the Pleistocene and came into secondary contact during late Holocene. A total of 300 SNPs distributed across the 12 linkage groups (LG) of black spruce were genotyped for 385 individual trees from 33 populations distributed across the allopatric zone of each species and within the zone of sympatry. An integrative framework combining three population genomic approaches was used to scan the genomes, revealing heterogeneous patterns of introgression. A total of 23 SNPs scattered over 10 LG were considered impermeable to introgression and putatively under diverging selection. These loci revealed the existence of impermeable genomic regions forming the species boundary and are thus indicative of ongoing speciation between these two genetic lineages. Another 238 SNPs reflected selectively neutral diffusion across the porous species barrier. Finally, 39 highly permeable SNPs suggested ancestral polymorphism along with balancing selection. The heterogeneous patterns of introgression across the genome indicated that the speciation process between black spruce and red spruce is young and incomplete, albeit some interspecific differences are maintained, allowing ongoing species divergence even in sympatry. The approach developed in this study can be used to track the progression of ongoing speciation processes. © 2015 John Wiley & Sons Ltd.

  11. Global wind power development: Economics and policies

    International Nuclear Information System (INIS)

    Timilsina, Govinda R.; Cornelis van Kooten, G.; Narbel, Patrick A.

    2013-01-01

    Existing literature indicates that theoretically, the earth's wind energy supply potential significantly exceeds global energy demand. Yet, only 2–3% of global electricity demand is currently derived from wind power despite 27% annual growth in wind generating capacity over the last 17 years. More than 95% of total current wind power capacity is installed in the developed countries plus China and India. Our analysis shows that the economic competitiveness of wind power varies at wider range across countries or locations. A climate change damage cost of US$20/tCO 2 imposed to fossil fuels would make onshore wind competitive to all fossil fuels for power generation; however, the same would not happen to offshore wind, with few exceptions, even if the damage cost is increased to US$100/tCO 2 . To overcome a large number of technical, financial, institutional, market and other barriers to wind power, many countries have employed various policy instruments, including capital subsidies, tax incentives, tradable energy certificates, feed-in tariffs, grid access guarantees and mandatory standards. Besides, climate change mitigation policies, such as the Clean Development Mechanism, have played a pivotal role in promoting wind power. Despite these policies, intermittency, the main technical constraint, could remain as the major challenge to the future growth of wind power. - Highlights: • Global wind energy potential is enormous, yet the wind energy contribution is very small. • Existing policies are boosting development of wind power. • Costs of wind energy are higher than cost of fossil-based energies. • Reasonable premiums for climate change mitigation substantially promote wind power. • Intermittency is the key challenge to future development of wind power

  12. Forecasting wind power production from a wind farm using the RAMS model

    DEFF Research Database (Denmark)

    Tiriolo, L.; Torcasio, R. C.; Montesanti, S.

    2015-01-01

    The importance of wind power forecast is commonly recognized because it represents a useful tool for grid integration and facilitates the energy trading. This work considers an example of power forecast for a wind farm in the Apennines in Central Italy. The orography around the site is complex...... and the horizontal resolution of the wind forecast has an important role. To explore this point we compared the performance of two 48 h wind power forecasts using the winds predicted by the Regional Atmospheric Modeling System (RAMS) for the year 2011. The two forecasts differ only for the horizontal resolution...... of the ECMWF Integrated Forecasting System (IFS), whose horizontal resolution over Central Italy is about 25 km at the time considered in this paper. Because wind observations were not available for the site, the power curve for the whole wind farm was derived from the ECMWF wind operational analyses available...

  13. Rotor equivalent wind speed for power curve measurement – comparative exercise for IEA Wind Annex 32

    DEFF Research Database (Denmark)

    Wagner, Rozenn; Cañadillas, B.; Clifton, A.

    2014-01-01

    A comparative exercise has been organised within the International Energy Agency (IEA) Wind Annex 32 in order to test the Rotor Equivalent Wind Speed (REWS) method under various conditions of wind shear and measurement techniques. Eight organisations from five countries participated in the exercise....... Each member of the group has derived both the power curve based on the wind speed at hub height and the power curve based on the REWS. This yielded results for different wind turbines, located in diverse types of terrain and where the wind speed profile was measured with different instruments (mast...... was the definition of the segment area used as weighting for the wind speeds measured at the various heights in the calculation of the REWS. This comparative exercise showed that the REWS method results in a significant difference compared to the standard method using the wind speed at hub height in conditions...

  14. Earth aeolian wind streaks: Comparison to wind data from model and stations

    Science.gov (United States)

    Cohen-Zada, A. L.; Maman, S.; Blumberg, D. G.

    2017-05-01

    Wind streak is a collective term for a variety of aeolian features that display distinctive albedo surface patterns. Wind streaks have been used to map near-surface winds and to estimate atmospheric circulation patterns on Mars and Venus. However, because wind streaks have been studied mostly on Mars and Venus, much of the knowledge regarding the mechanism and time frame of their formation and their relationship to the atmospheric circulation cannot be verified. This study aims to validate previous studies' results by a comparison of real and modeled wind data with wind streak orientations as measured from remote-sensing images. Orientations of Earth wind streaks were statistically correlated to resultant drift direction (RDD) values calculated from reanalysis and wind data from 621 weather stations. The results showed good agreement between wind streak orientations and reanalysis RDD (r = 0.78). A moderate correlation was found between the wind streak orientations and the weather station data (r = 0.47); a similar trend was revealed on a regional scale when the analysis was performed by continent, with r ranging from 0.641 in North America to 0.922 in Antarctica. At sites where wind streak orientations did not correspond to the RDDs (i.e., a difference of 45°), seasonal and diurnal variations in the wind flow were found to be responsible for deviation from the global pattern. The study thus confirms that Earth wind streaks were formed by the present wind regime and they are indeed indicative of the long-term prevailing wind direction on global and regional scales.

  15. Wind Loads on Structures

    DEFF Research Database (Denmark)

    Dyrbye, Claes; Hansen, Svend Ole

    Wind loads have to be taken into account when designing civil engineering structures. The wind load on structures can be systematised by means of the wind load chain: wind climate (global), terrain (wind at low height), aerodynamic response (wind load to pressure), mechanical response (wind...... pressure to structural response) and design criteria. Starting with an introduction of the wind load chain, the book moves on to meteorological considerations, atmospheric boundary layer, static wind load, dynamic wind load and scaling laws used in wind-tunnel tests. The dynamic wind load covers vibrations...... induced by wind turbulence, vortex shedding, flutter and galloping. The book gives a comprehensive treatment of wind effects on structures and it will be useful for consulting engineers designing wind-sensitive structures. It will also be valuable for students of civil engineering as textbook...

  16. Association between empirically derived dietary patterns with blood lipids, fasting blood glucose and blood pressure in adults - the India migration study.

    Science.gov (United States)

    Shridhar, Krithiga; Satija, Ambika; Dhillon, Preet K; Agrawal, Sutapa; Gupta, Ruby; Bowen, Liza; Kinra, Sanjay; Bharathi, A V; Prabhakaran, D; Srinath Reddy, K; Ebrahim, Shah

    2018-02-08

    Dietary patterns (DPs) in India are heterogenous. To date, data on association of indigenous DPs in India with risk factors of nutrition-related noncommunicable diseases (cardiovascular disease and diabetes), leading causes of premature death and disability, are limited. We aimed to evaluate the associations of empirically-derived DPs with blood lipids, fasting glucose and blood pressure levels in an adult Indian population recruited across four geographical regions of India. We used cross-sectional data from the Indian Migration Study (2005-2007). Study participants included urban migrants, their rural siblings and urban residents and their urban siblings from Lucknow, Nagpur, Hyderabad and Bangalore (n = 7067, mean age 40.8 yrs). Information on diet (validated interviewer-administered, 184-item semi-quantitative food frequency questionnaire), tobacco consumption, alcohol intake, physical activity, medical history, as well as anthropometric measurements were collected. Fasting-blood samples were collected for estimation of blood lipids and glucose. Principal component analysis (PCA) was used to identify major DPs based on eigenvalue> 1 and component interpretability. Robust standard error multivariable linear regression models were used to investigate the association of DPs (tertiles) with total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C), triglycerides, fasting-blood glucose (FBG), systolic and diastolic blood pressure (SBP and DBP) levels. Three major DPs were identified: 'cereal-savoury' (cooked grains, rice/rice-based dishes, snacks, condiments, soups, nuts), 'fruit-vegetable-sweets-snacks' (Western cereals, vegetables, fruit, fruit juices, cooked milk products, snacks, sugars, sweets) and 'animal food' (red meat, poultry, fish/seafood, eggs) patterns. High intake of the 'animal food' pattern was positively associated with levels of TC (β = 0.10 mmol/L; 95% CI: 0.02, 0.17 mmol/L; p

  17. Role of Wind Tunnels in Aircraft Design

    Indian Academy of Sciences (India)

    Wind tunnel is an aerodynamic test facility. It is mostly used to study flow patterns around bodies and measure aerodynamic forces on them. The bodies (called models) are usually scaled down but geometrically similar versions of bodies of interest like an airplane or an automobile. The results from wind tunnel tests can be ...

  18. Effects of Yaw Error on Wind Turbine Running Characteristics Based on the Equivalent Wind Speed Model

    Directory of Open Access Journals (Sweden)

    Shuting Wan

    2015-06-01

    Full Text Available Natural wind is stochastic, being characterized by its speed and direction which change randomly and frequently. Because of the certain lag in control systems and the yaw body itself, wind turbines cannot be accurately aligned toward the wind direction when the wind speed and wind direction change frequently. Thus, wind turbines often suffer from a series of engineering issues during operation, including frequent yaw, vibration overruns and downtime. This paper aims to study the effects of yaw error on wind turbine running characteristics at different wind speeds and control stages by establishing a wind turbine model, yaw error model and the equivalent wind speed model that includes the wind shear and tower shadow effects. Formulas for the relevant effect coefficients Tc, Sc and Pc were derived. The simulation results indicate that the effects of the aerodynamic torque, rotor speed and power output due to yaw error at different running stages are different and that the effect rules for each coefficient are not identical when the yaw error varies. These results may provide theoretical support for optimizing the yaw control strategies for each stage to increase the running stability of wind turbines and the utilization rate of wind energy.

  19. The Impact of Variable Wind Shear Coefficients on Risk Reduction of Wind Energy Projects

    Science.gov (United States)

    Thomson, Allan; Yoonesi, Behrang; McNutt, Josiah

    2016-01-01

    Estimation of wind speed at proposed hub heights is typically achieved using a wind shear exponent or wind shear coefficient (WSC), variation in wind speed as a function of height. The WSC is subject to temporal variation at low and high frequencies, ranging from diurnal and seasonal variations to disturbance caused by weather patterns; however, in many cases, it is assumed that the WSC remains constant. This assumption creates significant error in resource assessment, increasing uncertainty in projects and potentially significantly impacting the ability to control gird connected wind generators. This paper contributes to the body of knowledge relating to the evaluation and assessment of wind speed, with particular emphasis on the development of techniques to improve the accuracy of estimated wind speed above measurement height. It presents an evaluation of the use of a variable wind shear coefficient methodology based on a distribution of wind shear coefficients which have been implemented in real time. The results indicate that a VWSC provides a more accurate estimate of wind at hub height, ranging from 41% to 4% reduction in root mean squared error (RMSE) between predicted and actual wind speeds when using a variable wind shear coefficient at heights ranging from 33% to 100% above the highest actual wind measurement. PMID:27872898

  20. Stellar winds

    International Nuclear Information System (INIS)

    Weymann, R.J.

    1978-01-01

    It is known that a steady outflow of material at comparable rates of mass loss but vastly different speeds is now known to be ubiquitous phenomenon among both the luminous hot stars and the luminous but cool red giants. The flows are probably massive enough in both cases to give rise to significant effects on stellar evolution and the mass balance between stars and the interstellar medium. The possible mechanisms for these phenomena as well as the methods of observation used are described. In particular, the mass-loss processes in stars other than the sun that also involve a steady flow of matter are considered. The evidence for their existence is described, and then the question of whether the process thought to produce the solar wind is also responsible for producing these stellar winds is explored

  1. Wind conditions for wind turbine design

    Energy Technology Data Exchange (ETDEWEB)

    Maribo Pedersen, B.

    1999-04-01

    Delegates from Europe and USA attended the meeting and discussed general aspects of wind conditions for wind turbine design. The subjects and the presented papers covered a very broad range of aspects of wind conditions and related influence on the wind turbine. (EHS)

  2. Modern lineages of Mycobacterium tuberculosis exhibit lineage-specific patterns of growth and cytokine induction in human monocyte-derived macrophages.

    Directory of Open Access Journals (Sweden)

    Rajesh Sarkar

    Full Text Available Strains of Mycobacterium tuberculosis vary in virulence. Strains that have caused outbreaks in the United States and United Kingdom have been shown to subvert the innate immune response as a potential immune evasion mechanism. There is, however, little information available as to whether these patterns of immune subversion are features of individual strains or characteristic of broad clonal lineages of M. tuberculosis.Strains from two major modern lineages (lineage 2 [East-Asian] and lineage 4 [Euro-American] circulating in the Western Cape in South Africa as well as a comparator modern lineage (lineage 3 [CAS/Delhi] were identified. We assessed two virulence associated characteristics: mycobacterial growth (in liquid broth and monocyte derived macrophages and early pro-inflammatory cytokine induction.In liquid culture, Lineage 4 strains grew more rapidly and reached higher plateau levels than other strains (lineage 4 vs. lineage 2 p=0.0024; lineage 4 vs. lineage 3 p=0.0005. Lineage 3 strains were characterized by low and early plateau levels, while lineage 2 strains showed an intermediate growth phenotype. In monocyte-derived macrophages, lineage 2 strains grew faster than lineage 3 strains (p<0.01 with lineage 4 strains having an intermediate phenotype. Lineage 2 strains induced the lowest levels of pro-inflammatory TNF and IL-12p40 as compared to other lineages (lineage 2: median TNF 362 pg/ml, IL-12p40 91 pg/ml; lineage 3: median TNF 1818 pg/ml, IL-12p40 123 pg/ml; lineage 4: median TNF 1207 pg/ml, IL-12p40 205 pg/ml;. In contrast, lineage 4 strains induced high levels of IL-12p40 and intermediate level of TNF. Lineage 3 strains induced high levels of TNF and intermediate levels of IL-12p40.Strains of M. tuberculosis from the three major modern strain lineages possess distinct patterns of growth and cytokine induction. Rapid growth and immune subversion may be key characteristics to the success of these strains in different human populations.

  3. An analysis of UK wind farm statistics

    International Nuclear Information System (INIS)

    Milborrow, D.J.

    1995-01-01

    An analysis of key data for 22 completed wind projects shows 134 MW of plant cost Pound 152 million, giving an average cost of Pound 1136/kW. The energy generation potential of these windfarms is around 360 GWh, derived from sites with windspeeds between 6.2 and 8.8 m/s. Relationships between wind speed, energy production and cost were examined and it was found that costs increased with wind speed, due to the difficulties of access in hilly regions. It also appears that project costs fell with time and wind energy prices have fallen much faster than electricity prices. (Author)

  4. Load alleviation on wind turbine blades using variable geometry

    DEFF Research Database (Denmark)

    Basualdo, Santiago

    2005-01-01

    ) wind turbines, which mainly operate under this flow condition. The results show evident reductions in the airfoil displacements by using simple control strategies having the airfoil position and its first and second derivatives as input, especially at the system's eigenfrequency. The use of variable...... in loads in real wind turbines. Keywords: Variable Geometry, Wind Turbine, Load Alleviation, Fatigue Load, Trailing Edge Flap....

  5. Wind Technologies & Evolving Opportunities (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Robichaud, R.

    2014-07-01

    This presentation covers opportunities for wind technology; wind energy market trends; an overview of the National Wind Technology Center near Boulder, Colorado; wind energy price and cost trends; wind turbine technology improvements; and wind resource characterization improvements.

  6. Unraveling Climatic Wind and Wave Trends in the Red Sea Using Wave Spectra Partitioning

    KAUST Repository

    Langodan, Sabique

    2017-12-27

    The wind and wave climatology of the Red Sea is derived from a validated 30-year high-resolution model simulation. After describing the relevant features of the basin, the main wind and wave systems are identified by using an innovative spectral partition technique to explain their genesis and characteristics. In the northern part of the sea, wind and waves of the same intensity are present throughout the year, while the central and southern zones are characterized by a marked seasonality. The partition technique allows the association of a general decrease in the energy of the different wave systems with a specific weather pattern. The most intense decrease is found in the northern storms, which are associated with meteorological pulses from the Mediterranean Sea.

  7. Low-temperature plasma etching of high aspect-ratio densely packed 15 to sub-10 nm silicon features derived from PS-PDMS block copolymer patterns

    International Nuclear Information System (INIS)

    Liu, Zuwei; Sassolini, Simone; Olynick, Deirdre L; Gu, Xiaodan; Hwu, Justin

    2014-01-01

    The combination of block copolymer (BCP) lithography and plasma etching offers a gateway to densely packed sub-10 nm features for advanced nanotechnology. Despite the advances in BCP lithography, plasma pattern transfer remains a major challenge. We use controlled and low substrate temperatures during plasma etching of a chromium hard mask and then the underlying substrate as a route to high aspect ratio sub-10 nm silicon features derived from BCP lithography. Siloxane masks were fabricated using poly(styrene-b-siloxane) (PS-PDMS) BCP to create either line-type masks or, with the addition of low molecular weight PS-OH homopolymer, dot-type masks. Temperature control was essential for preventing mask migration and controlling the etched feature’s shape. Vertical silicon wire features (15 nm with feature-to-feature spacing of 26 nm) were etched with aspect ratios up to 17 : 1; higher aspect ratios were limited by the collapse of nanoscale silicon structures. Sub-10 nm fin structures were etched with aspect ratios greater than 10 : 1. Transmission electron microscopy images of the wires reveal a crystalline silicon core with an amorphous surface layer, just slightly thicker than a native oxide. (paper)

  8. Up-to-date Clinical Trials of Hair Regeneration Using Conditioned Media of Adipose-Derived Stem Cells in Male and Female Pattern Hair Loss.

    Science.gov (United States)

    Shin, Hyoseung; Won, Chong Hyun; Chung, Woon-Kyung; Park, Byung-Soon

    2017-01-01

    The primary roles of mesenchymal stem cells (MSCs) are to maintain the stem cell niche, facilitate recovery after injury, and ensure healthy aging and the homeostasis of organ and tissues. MSCs have recently emerged as a new therapeutic option for hair loss. Since adipose-derived stem cells (ADSCs) are the most accessible sources of MSCs, ADSCbased hair regeneration is investigated. Besides replacing degenerated cells in affected organs, ADSCs exhibit their beneficial effects through the paracrine actions of various cytokines and growth factors. Several laboratory experiments and animal studies have shown that ADSC-related proteins can stimulate hair growth. In addition, we introduce our clinical pilot studies using conditioned media of ADSCs for pattern hair loss in men and women. We believe that conditioned media of ADSCs represents a promising alternative therapeutic strategy for hair loss. We also discuss practical therapeutic challenges and the direction of future research. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  9. Wind fluctuations over the North Sea

    DEFF Research Database (Denmark)

    Vincent, Claire Louise; Pinson, Pierre; Giebel, Gregor

    2011-01-01

    Climatological patterns in wind speed fluctuations with periods of 1 min to 10 h are analysed using data from a meteorological mast in the Danish North Sea. Fluctuations on these time scales are of particular relevance to the effective management of the power supply from large wind farms. The Hil......Climatological patterns in wind speed fluctuations with periods of 1 min to 10 h are analysed using data from a meteorological mast in the Danish North Sea. Fluctuations on these time scales are of particular relevance to the effective management of the power supply from large wind farms...... a certain class of conditions can be found. Here, the HHT is applied to create conditional spectra which demonstrate patterns in the occurrence of severe wind variability. It is shown that wind fluctuations over the North Sea are more severe for westerly flow than for easterly flow, and that severe...... fluctuations are often observed in the vicinity of precipitation. The most severe wind fluctuations occur in the autumn and winter seasons, and are slightly more common when the pressure tendency is rising. Further, it is found that the wind is more variable for atmospherically unstable conditions than...

  10. WIND VARIABILITY IN BZ CAMELOPARDALIS

    International Nuclear Information System (INIS)

    Honeycutt, R. K.; Kafka, S.; Robertson, J. W.

    2013-01-01

    Sequences of spectra of the nova-like cataclysmic variable (CV) BZ Cam were acquired on nine nights in 2005-2006 in order to study the time development of episodes of wind activity known to occur frequently in this star. We confirm the results of Ringwald and Naylor that the P-Cygni absorption components of the lines mostly evolve from higher expansion velocity to lower velocity as an episode progresses. We also commonly find blueshifted emission components in the Hα line profile, whose velocities and durations strongly suggest that they are also due to the wind. Curiously, Ringwald and Naylor reported common occurrences of redshifted Hα emission components in their BZ Cam spectra. We have attributed these emission components in Hα to occasions when gas concentrations in the bipolar wind (both front side and back side) become manifested as emission lines as they move beyond the disk's outer edge. We also suggest, based on changes in the P-Cygni profiles during an episode, that the progression from larger to smaller expansion velocities is due to the higher velocity portions of a wind concentration moving beyond the edge of the continuum light of the disk first, leaving a net redward shift of the remaining absorption profile. We derive a new orbital ephemeris for BZ Cam, using the radial velocity of the core of the He I λ5876 line, finding P = 0.15353(4). Using this period, the wind episodes in BZ Cam are found to be concentrated near the inferior conjunction of the emission line source. This result helps confirm that the winds in nova-like CVs are often phase dependent, in spite of the puzzling implication that such winds lack axisymmetry. We argue that the radiation-driven wind in BZ Cam receives an initial boost by acting on gas that has been lifted above the disk by the interaction of the accretion stream with the disk, thereby imposing flickering timescales onto the wind events, as well as leading to an orbital modulation of the wind due to the non

  11. The effect of vegetation on wind-blown mass transport at the regional scale: A wind tunnel experiment

    NARCIS (Netherlands)

    Youssef, I.F.; Visser, S.M.; Karssenberg, D.; Erpul, G.; Cornelis, W.M.; Gabriels, D.; Poortinga, A.

    2012-01-01

    Wind erosion is a global environmental problem. Re-vegetating land is a commonly used method to reduce the negative effects of wind erosion. However, there is limited knowledge on the effect of vegetation pattern on wind-blown mass transport. The objective of this study was to investigate the effect

  12. Wind energy resources assessment for Yanbo, Saudi Arabia

    International Nuclear Information System (INIS)

    Rehman, Shafiqur

    2004-01-01

    The paper presents long term wind data analysis in terms of annual, seasonal and diurnal variations at Yanbo, which is located on the west coast of Saudi Arabia. The wind speed and wind direction hourly data for a period of 14 years between 1970 and 1983 is used in the analysis. The analysis showed that the seasonal and diurnal pattern of wind speed matches the electricity load pattern of the location. Higher winds of the order of 5.0 m/s and more were observed during the summer months of the year and noon hours (09:00 to 16:00 h) of the day. The wind duration availability is discussed as the percent of hours during which the wind remained in certain wind speed intervals or bins. Wind energy calculations were performed using wind machines of sizes 150, 250, 600, 800, 1000, 1300, 1500, 2300 and 2500 kW rated power. Wind speed is found to remain above 3.5 m/s for 69% of the time during the year at 40, 50, 60, and 80 m above ground level. The energy production analysis showed higher production from wind machines of smaller sizes than the bigger ones for a wind farm of 30 MW installed capacity. Similarly, higher capacity factors were obtained for smaller wind machines compared to larger ones

  13. Wind Power Meteorology

    DEFF Research Database (Denmark)

    Lundtang Petersen, Erik; Mortensen, Niels Gylling; Landberg, Lars

    Wind power meteorology has evolved as an applied science, firmly founded on boundary-layer meteorology, but with strong links to climatology and geography. It concerns itself with three main areas: siting of wind turbines, regional wind resource assessment, and short-term prediction of the wind...... resource. The history, status and perspectives of wind power meteorology are presented, with emphasis on physical considerations and on its practical application. Following a global view of the wind resource, the elements of boundary layer meteorology which are most important for wind energy are reviewed......: wind profiles and shear, turbulence and gust, and extreme winds. The data used in wind power meteorology stem mainly from three sources: onsite wind measurements, the synoptic networks, and the re-analysis projects. Wind climate analysis, wind resource estimation and siting further require a detailed...

  14. Model predictive control for wind power gradients

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel; Boyd, Stephen; Jørgensen, John Bagterp

    2015-01-01

    We consider the operation of a wind turbine and a connected local battery or other electrical storage device, taking into account varying wind speed, with the goal of maximizing the total energy generated while respecting limits on the time derivative (gradient) of power delivered to the grid. We...... wind data and modern wind forecasting methods. The simulation results using real wind data demonstrate the ability to reject the disturbances from fast changes in wind speed, ensuring certain power gradients, with an insignificant loss in energy production....... ranges. The system dynamics are quite non-linear, and the constraints and objectives are not convex functions of the control inputs, so the resulting optimal control problem is difficult to solve globally. In this paper, we show that by a novel change of variables, which focuses on power flows, we can...

  15. Adaptive Extremum Control and Wind Turbine Control

    DEFF Research Database (Denmark)

    Ma, Xin

    1997-01-01

    This thesis is divided into two parts, i.e., adaptive extremum control and modelling and control of a wind turbine. The rst part of the thesis deals with the design of adaptive extremum controllers for some processes which have the behaviour that process should have as high e ciency as possible...... in parameters, and thus directly lends itself to parameter estimation and adaptive control. The extremum control law is derived based on static optimization of a performance function. For a process with nonlinearity at output the intermediate signal between the linear part and nonlinear part plays an important...... role. If it can be emphasis on control design. The models have beenvalidated by experimental data obtained from an existing wind turbine. The e ective wind speed experienced by the rotor of a wind turbine, which is often required by some control methods, is estimated by using a wind turbine as a wind...

  16. Analysis of Anholt offshore wind farm SCADA measurements

    DEFF Research Database (Denmark)

    Hansen, Kurt Schaldemose; Volker, Patrick; Pena Diaz, Alfredo

    SCADA measurements from the Danish Anholt offshore wind farm (ANH) for a period of 2½ years have been qualified. ANH covers 12 km × 22 km and is located between Djursland and the island Anholt in Kattegat, Denmark. This qualification encompasses identification of curtailment and idling periods......, start/stop events and a power curve control for each wind turbine in the wind farm. Data also include wind speed measurements from a nearby WindCube lidar and simulations from the WRF model for the same period as the SCADA. An equivalent wind speed (wsi) is derived from the combined power and pitch...

  17. Wind effect in turbulence parametrization

    Science.gov (United States)

    Colombini, M.; Stocchino, A.

    2005-09-01

    The action of wind blowing over a closed basin ultimately results in a steady shear-induced circulation pattern and in a leeward rising of the free surface—and a corresponding windward lowering—known as wind set-up. If the horizontal dimensions of the basin are large with respect to the average flow depth, the occurrence of local quasi-equilibrium conditions can be expected, i.e. the flow can be assumed to be locally driven only by the wind stress and by the opposing free surface gradient due to set-up. This wind-induced flow configuration shows a strong similarity with turbulent Couette-Poiseuille flow, the one dimensional flow between parallel plates generated by the simultaneous action of a constant pressure gradient and of the shear induced by the relative motion of the plates. A two-equation turbulence closure is then employed to perform a numerical study of turbulent Couette-Poiseuille flows for different values of the ratio of the shear stresses at the two walls. The resulting eddy viscosity vertical distributions are analyzed in order to devise analytical profiles of eddy viscosity that account for the effect of wind. The results of this study, beside allowing for a physical insight on the turbulence process of this class of flows, will allow for a more accurate description of the wind effect to be included in the formulation of quasi-3D and 3D models of lagoon hydrodynamics.

  18. Assessment of regional wind energy resources over the Ukraine

    Science.gov (United States)

    Sobchenko, Anastasiia; Khomenko, Inna

    2015-04-01

    The purpose of the study has been to provide a preliminary assessment of different regions of the Ukraine. Investigation is based on thirty-minute wind observations collected through an 8-year period (January 1, 2002 to December 31, 2008) for seven airports of the Ukraine. For renewal of vertical profile of the wind direction and speed radiosounding data were used. By applying of the probabilistic analysis techniques to series of wind data and the wind extreme values, yearly, monthly and diurnal variation of wind speed and direction are derived. Based on these results theoretical distribution functions and exceeding probability are found for each airport. The statistic characteristics obtained were compared with the correspondent values provided for 1936-1960 and 1961-1990 periods and site-related temporal changeability is determined. For each period considered assessment of wind resources at 10 meters height is carried out. Since the geostrophic wind are frequently used to calculate the surface wind at heights between 10 and 200 m, in the research the distribution of the geostrophic wind for each airport were determined. Comparative analysis of distribution and statistic characteristics of geostrophic and surface winds are made. The relation between a set of values of the geostrophic wind and a set of values of the surface wind speed was provided for each airport. Using different relationship for variation of wind speed with height wind resources at heights between 10 and 200 were assessed. The results obtained show that with the lapse of the time wind speed and wind resources is decreased half the size. It is reflected general tendencies in the wind speed changeability over the European territory. Places which are most perspective for wind turbine installation are off-shore sites such as Odessa, and sites situated in the Crimea mountain (Simferopol) and the Donetsk ridge (Donetsk). The results derived in the contribution may be used for modeling and mapping wind

  19. Prospecting for Wind

    Science.gov (United States)

    Swapp, Andy; Schreuders, Paul; Reeve, Edward

    2011-01-01

    Many people use wind to help meet their needs. Over the years, people have been able to harness or capture the wind in many different ways. More recently, people have seen the rebirth of electricity-generating wind turbines. Thus, the age-old argument about technology being either good or bad can also be applied to the wind. The wind can be a…

  20. Careers in Wind Energy

    Science.gov (United States)

    Liming, Drew; Hamilton, James

    2011-01-01

    As a common form of renewable energy, wind power is generating more than just electricity. It is increasingly generating jobs for workers in many different occupations. Many workers are employed on wind farms: areas where groups of wind turbines produce electricity from wind power. Wind farms are frequently located in the midwestern, western, and…

  1. What's Powering Wind? Measuring the Environmental Benefits of Wind Generated Electricity

    OpenAIRE

    Cullen, Joseph

    2008-01-01

    Production subsidies for renewable energy have experienced intermittent support from the federal government. One reason for less than united support arises from uncertainty over the environmental impact of projects implemented because of such subsidies. Wind energy in particular has taken advantage of federal subsidies, but what has been the environmental impact? Taking investment in wind capacity as given, I am able to identify the short run substitution patterns between wind power and conve...

  2. Airfoil characteristics for wind turbines

    DEFF Research Database (Denmark)

    Bak, C.; Fuglsang, P.; Sørensen, Niels N.

    1999-01-01

    is capable of determining the correct qualitative behaviour for airfoils subject to rotation. The method shows that lift is high at the root compared to 2D airfoil characteristics. Thedifferent systematic methods show the importance of rotational and 3D effects on rotors. Furthermore, the methods show high......Airfoil characteristics for use in the Blade Element Momentum (BEM) method calculating the forces on Horizontal Axis Wind Turbines (HAWT) are derived by use of systematic methods. The investigation and derivation of the airfoil characteristics are basedon four different methods: 1) Inverse momentum...... theory, 2) Actuator disc theory, 3) Numerical optimisation and 4) Quasi-3D CFD computations. The two former methods are based on 3D CFD computations and wind tunnel measurements on a 41-m full-scale rotorwith LM 19.1 blades. The derived airfoil characteristics show that the lift coefficient in stall...

  3. Calculation of Wind Compensation for Launching of Unguided Rockets

    Science.gov (United States)

    James, Robert L., Jr.; Harris, Ronald J.

    1961-01-01

    A method for calculating wind compensation for unguided missiles s derived which has a greater degree of flexibility than the previously proposed methods. Utilization of the wind-compensation technique is demonstrated by using the Shotput vehicle as a model. Postflight simulations of four of these missiles with the use of measured winds show that if the winds are known, very good accuracy can be obtained by using the proposed method.

  4. Configuration study of large wind parks

    Energy Technology Data Exchange (ETDEWEB)

    Lundberg, Stefan

    2003-07-01

    In this thesis, layouts of various large-scale wind parks, using both AC as well as DC, are investigated. Loss modelling of the wind park components as well as calculations of the energy capture of the turbines using various electrical systems are performed, and the energy production cost of the various park configurations is determined. The most interesting candidate for a DC transmission based wind park was investigated more in detail, the series DC wind park. Finally, the power quality impact in the PCC (point of common coupling) was studied. It was found that from an energy capture point of view, the difference in energy production between various wind turbine systems is very small. Of all the investigated wind park configurations, the wind park with the series connected DC wind turbines seems to have the best potential to give the lowest energy production cost, if the transmission distance is longer then 10-20 km. Regarding the series DC wind park it was found that it is the most difficult one to control. However, a control algorithm for the series park and its turbines was derived and successfully tested. Still, several more details regarding the control of the series wind park has to be dealt with.

  5. Behaviour of glass plates under wind loads

    Science.gov (United States)

    Gavanski, Eri

    Glazing damage during strong windstorms has been considered to result mainly from windborne debris. However, recent windstorm damage reports have revealed the necessity of studying fluctuating wind loads, which appear to be another factor contributing to this damage. From an experimental point of view, studies on this topic have been limited to the application of rather simple loading patterns. Moreover, there is an uncertainty surrounding both load resistance and design load used in the current North American window glass design codes. It is of concern that these regulations may not offer sufficient accuracy on account of the limited understanding of time-dependent glass strength derived from the technology available at the time of codification. Unprecedented full-scale glass breakage tests under realistic wind pressure loading were conducted to investigate these issues. The obtained results revealed significant new information about the behavior of glass plates under fluctuating loads. Along with these tests, a numerical simulation using the Monte-Carlo technique was also performed with a subtle modification of the initial glass strength. This adjustment resulted in better correspondence with test results. Using the test and numerical simulation results, the current window glass design method was examined. The calculation methods of LR, and the reference time conversion used in the codes, were found to require further investigation. By creating a particular wind pressure time history, the practice of using peak pressures from ASCE7-05 as the design load was investigated. The results showed that there are cases when the current practice may underestimate the design load because of the duration of windstorms. KEYWORDS: Glass, Fluctuating load, Full-scale test, Load resistance, Design load, Static fatigue, Numerical simulation, Monte-Carlo technique, Brown's integral.

  6. Review of the wind energy activities in South Africa

    CSIR Research Space (South Africa)

    Szewczuk, S

    2014-03-01

    Full Text Available , in third place after coal, 45,9%, and nuclear, 12,7%. SOUTH AFRICA’S WIND CLIMATE South Africa’s wind resources are influenced by the large scale weather patterns that have distinct characteristics between summer and winter. Summer Winds... financial instruments tha t should be made available to stimulate commercial wind energy developments; (2) Green power funding initialized, by assisting initiatives geared towards green power marketing and setting up and implementing Tradable...

  7. Rotor equivalent wind speed for power curve measurement - comparative exercise for IEA Wind Annex 32

    Science.gov (United States)

    Wagner, R.; Cañadillas, B.; Clifton, A.; Feeney, S.; Nygaard, N.; Poodt, M.; St. Martin, C.; Tüxen, E.; Wagenaar, J. W.

    2014-06-01

    A comparative exercise has been organised within the International Energy Agency (IEA) Wind Annex 32 in order to test the Rotor Equivalent Wind Speed (REWS) method under various conditions of wind shear and measurement techniques. Eight organisations from five countries participated in the exercise. Each member of the group has derived both the power curve based on the wind speed at hub height and the power curve based on the REWS. This yielded results for different wind turbines, located in diverse types of terrain and where the wind speed profile was measured with different instruments (mast or various lidars). The participants carried out two preliminary steps in order to reach consensus on how to implement the REWS method. First, they all derived the REWS for one 10 minute wind speed profile. Secondly, they all derived the power curves for one dataset. The main point requiring consensus was the definition of the segment area used as weighting for the wind speeds measured at the various heights in the calculation of the REWS. This comparative exercise showed that the REWS method results in a significant difference compared to the standard method using the wind speed at hub height in conditions with large shear and low turbulence intensity.

  8. Optimum Operational Parameters for Yawed Wind Turbines

    Directory of Open Access Journals (Sweden)

    David A. Peters

    2011-01-01

    Full Text Available A set of systematical optimum operational parameters for wind turbines under various wind directions is derived by using combined momentum-energy and blade-element-energy concepts. The derivations are solved numerically by fixing some parameters at practical values. Then, the interactions between the produced power and the influential factors of it are generated in the figures. It is shown that the maximum power produced is strongly affected by the wind direction, the tip speed, the pitch angle of the rotor, and the drag coefficient, which are specifically indicated by figures. It also turns out that the maximum power can take place at two different optimum tip speeds in some cases. The equations derived herein can also be used in the modeling of tethered wind turbines which can keep aloft and deliver energy.

  9. [Effects of different re-vegetation patterns on soil organic carbon and total nitrogen in the wind-water erosion crisscross region, China].

    Science.gov (United States)

    Liu, Xue-tong; Wei, Yan-chun; Yang, Xian-long; Hao, Ming-de; Wei, Xiao-rong

    2016-01-01

    This study was conducted to analyze the responses of soil organic carbon (SOC) and total nitrogen (TN) to three typical re-vegetation patterns, i.e., grassland, alfalfa land and peashrub land on the Loess Plateau of China, and also to assess the dynamics of SOC and TN with re-vegetation age. The results showed that all the three re-vegetation practices increased the concentrations of SOC and TN in the 0-10 cm soil layer, but their effects differed with re-vegetation age. Compared with adjacent croplands, the concentrations of SOC and TN in the 0-10 cm soil layer in grassland did not change within 10 years of succession, but increased after 20 years of succession. In alfalfa land, the concentrations of SOC and TN increased by 51.6%-82.9% and 43.4%-67.0% in the 0-10 cm soil layer, with the increasing rates of stocks of SOC and TN being 0.17-0.46 and 0.015-0.043 t · hm⁻² · a⁻¹, respectively. However, SOC and TN were not affected by re-vegetation age in alfalfa land. The increases of concentrations of SOC and TN remained high in the first 20 years after conversion of cropland to peashrub land, but decreased after 40 years of conversion. In conclusion, the conversion of croplands to peashrub or alfalfa land could be better in contributing to high stocks of SOC and TN than natural succession of grassland. However, their positive effects on the enrichment of SOC and TN may not be sustainable due to the scarcity of soil moisture and high water consumption of these two re-vegetation plants.

  10. The dune effect on sand-transporting winds on Mars

    Science.gov (United States)

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

    2015-11-01

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

  11. Evaluation of wind flow with a nacelle-mounted, continuous wave wind lidar

    DEFF Research Database (Denmark)

    Medley, John; Barker, Will; Harris, Mike

    2014-01-01

    IR, increasing the confidence in the ZephIR for measuring wind parameters in this configuration. SCADA data from the turbine was combined with measured wind speeds and directions to derive power curves from the mast data (hub-height) and from ZephIR data (hub-height and rotor-equivalent). The rotor...

  12. Influence of wind loading

    OpenAIRE

    MAVLONOV RAVSHANBEK ABDUJABBOROVICH; VAKKASOV KHAYRULLO SAYFULLAHANOVICH

    2015-01-01

    Each wind load is determined by a probabilistic-statistical method based on the concept of “equivalent static wind load”, on the assumption that structural frames and components/cladding behave elastically in strong wind.

  13. Tower Winds - Cape Kennedy

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Digitized data taken from Wind Gust Charts. Record contains hourly wind directions and speed with a peak wind recorded at the end of each day. Sorted by: station,...

  14. Wind energy program overview

    International Nuclear Information System (INIS)

    1992-02-01

    This overview emphasizes the amount of electric power that could be provided by wind power rather than traditional fossil fuels. New wind power markets, advances in technology, technology transfer, and wind resources are some topics covered in this publication

  15. Modelling Wind for Wind Farm Layout Optimization Using Joint Distribution of Wind Speed and Wind Direction

    OpenAIRE

    Ju Feng; Wen Zhong Shen

    2015-01-01

    Reliable wind modelling is of crucial importance for wind farm development. The common practice of using sector-wise Weibull distributions has been found inappropriate for wind farm layout optimization. In this study, we propose a simple and easily implementable method to construct joint distributions of wind speed and wind direction, which is based on the parameters of sector-wise Weibull distributions and interpolations between direction sectors. It is applied to the wind measurement data a...

  16. Denmark Wind Energy Programme

    DEFF Research Database (Denmark)

    Shen, Wen Zhong

    2014-01-01

    In this paper, a summary of some ongoing wind energy projects in Denmark is given. The research topics comprise computational model development, wind turbine design, low noise airfoil and blade design, control device development, wake modelling, and wind farm layout optimization.......In this paper, a summary of some ongoing wind energy projects in Denmark is given. The research topics comprise computational model development, wind turbine design, low noise airfoil and blade design, control device development, wake modelling, and wind farm layout optimization....

  17. Superconducting Wind Turbine Generators

    OpenAIRE

    Yunying Pan; Danhzen Gu

    2016-01-01

    Wind energy is well known as a renewable energy because its clean and less polluted characteristic, which is the foundation of development modern wind electricity. To find more efficient wind turbine is the focus of scientists around the world. Compared from conventional wind turbines, superconducting wind turbine generators have advantages at zero resistance, smaller size and lighter weight. Superconducting wind turbine will inevitably become the main trends in this area. This paper intends ...

  18. Insights into the Role of Chemokines, Damage-Associated Molecular Patterns, and Lymphocyte-Derived Mediators from Computational Models of Trauma-Induced Inflammation

    Science.gov (United States)

    Namas, Rami A.; Mi, Qi; Namas, Rajaie; Almahmoud, Khalid; Zaaqoq, Akram M.; Abdul-Malak, Othman; Azhar, Nabil; Day, Judy; Abboud, Andrew; Zamora, Ruben; Billiar, Timothy R.

    2015-01-01

    Abstract Significance: Traumatic injury elicits a complex, dynamic, multidimensional inflammatory response that is intertwined with complications such as multiple organ dysfunction and nosocomial infection. The complex interplay between inflammation and physiology in critical illness remains a challenge for translational research, including the extrapolation to human disease from animal models. Recent Advances: Over the past decade, we and others have attempted to decipher the biocomplexity of inflammation in these settings of acute illness, using computational models to improve clinical translation. In silico modeling has been suggested as a computationally based framework for integrating data derived from basic biology experiments as well as preclinical and clinical studies. Critical Issues: Extensive studies in cells, mice, and human blunt trauma patients have led us to suggest (i) that while an adequate level of inflammation is required for healing post-trauma, inflammation can be harmful when it becomes self-sustaining via a damage-associated molecular pattern/Toll-like receptor-driven feed-forward circuit; (ii) that chemokines play a central regulatory role in driving either self-resolving or self-maintaining inflammation that drives the early activation of both classical innate and more recently recognized lymphoid pathways; and (iii) the presence of multiple thresholds and feedback loops, which could significantly affect the propagation of inflammation across multiple body compartments. Future Directions: These insights from data-driven models into the primary drivers and interconnected networks of inflammation have been used to generate mechanistic computational models. Together, these models may be used to gain basic insights as well as serving to help define novel biomarkers and therapeutic targets. Antioxid. Redox Signal. 23, 1370–1387. PMID:26560096

  19. Murine leukemia virus-derived retroviral vector has differential integration patterns in human cell lines used to produce recombinant factor VIII

    Directory of Open Access Journals (Sweden)

    Marcela Cristina Correa de Freitas

    2014-06-01

    Full Text Available OBJECTIVE: Nowadays recombinant factor VIII is produced in murine cells including in Chinese hamster ovary (CHO and baby hamster kidney cells (BHK. Previous studies, using the murine leukemia virus-derived retroviral vector pMFG-FVIII-P140K, modified two recombinant human cell lines, HepG2 and Hek293 to produce recombinant factor VIII. In order to characterize these cells, the present study aimed to analyze the integration pattern of retroviral vector pMFG-FVIII-P140K.METHODS: This study used ligation-mediated polymerase chain reaction to locate the site of viral vector integration by sequencing polymerase chain reaction products. The sequences were compared to genomic databases to characterize respective clones.RESULTS: The retroviral vector presented different and non-random profiles of integration between cells lines. A preference of integration for chromosomes 19, 17 and 11 was observed for HepG2FVIIIdB/P140K and chromosome 9 for Hek293FVIIIdB/P140K. In genomic regions such as CpG islands and transcription factor binding sites, there was no difference in the integration profiles for both cell lines. Integration in intronic regions of encoding protein genes (RefSeq genes was also observed in both cell lines. Twenty percent of integrations occurred at fragile sites in the genome of the HepG2 cell line and 17% in Hek293.CONCLUSION: The results suggest that the cell type can affect the profile of chromosomal integration of the retroviral vector used; these differences may interfere in the level of expression of recombinant proteins.

  20. Wind turbines, is it just wind?

    International Nuclear Information System (INIS)

    Boiteux, M.

    2012-01-01

    The author first outlines that wind energy is not only random, but almost absent in extreme situations when it would be needed (for example and notably, very cold weather without wind). He suggests the association of a gas turbine to each wind turbine, so that the gas turbine will replace non operating wind turbines. He notices that wind turbines are not proximity energy as they were said to be, and that profitability in fact requires tens of grouped giant wind turbines. He also outlines the high cost of construction of grids for the connection of these wind turbines. Thus, he states that wind energy is far from being profitable in the present conditions of electricity tariffs in France

  1. Advanced structural wind engineering

    CERN Document Server

    Kareem, Ahsan

    2013-01-01

    This book serves as a textbook for advanced courses as it introduces state-of-the-art information and the latest research results on diverse problems in the structural wind engineering field. The topics include wind climates, design wind speed estimation, bluff body aerodynamics and applications, wind-induced building responses, wind, gust factor approach, wind loads on components and cladding, debris impacts, wind loading codes and standards, computational tools and computational fluid dynamics techniques, habitability to building vibrations, damping in buildings, and suppression of wind-induced vibrations. Graduate students and expert engineers will find the book especially interesting and relevant to their research and work.

  2. Wind for Schools (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Baring-Gould, I.

    2010-05-01

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

  3. Flow separation on wind turbines blades

    Science.gov (United States)

    Corten, G. P.

    2001-01-01

    the angle of attack. The art of designing stall rotors is to make the separated area on the blades extend in such a way, that the extracted power remains precisely constant, independent of the wind speed, while the power in the wind at cut-out exceeds the maximum power of the turbine by a factor of 8. Since the stall behaviour is influenced by many parameters, this demand cannot be easily met. However, if it can be met, the advantage of stall control is its passive operation, which is reliable and cheap. Problem Definition In practical application, stall control is not very accurate and many stall-controlled turbines do not meet their specifications. Deviations of the design-power in the order of tens of percent are regular. In the nineties, the aerodynamic research on these deviations focussed on: profile aerodynamics, computational fluid dynamics, rotational effects on separation and pressure measurements on test turbines. However, this did not adequately solve the actual problems with stall turbines. In this thesis, we therefore formulated the following as the essential question: "Does the separated blade area really extend with the wind speed, as we predict?" To find the answer a measurement technique was required, which 1) was applicable on large commercial wind turbines, 2) could follow the dynamic changes of the stall pattern, 3) was not influenced by the centrifugal force and 4) did not disturb the flow. Such a technique was not available, therefore we decided to develop it. Stall Flag Method For this method, a few hundred indicators are fixed to the rotor blades in a special pattern. These indicators, called "stall flags" are patented by the Netherlands Energy Research Foundation (ECN). They have a retro-reflective area which, depending on the flow direction, is or is not covered. A powerful light source in the field up to 500m behind the turbine illuminates the swept rotor area. The uncovered reflectors reflect the light to the source, where a digital video

  4. Investigation of wind characteristics and assessment of wind energy potential for Waterloo region, Canada

    International Nuclear Information System (INIS)

    Li Meishen; Li Xianguo

    2005-01-01

    Wind energy becomes more and more attractive as one of the clean renewable energy resources. Knowledge of the wind characteristics is of great importance in the exploitation of wind energy resources for a site. It is essential in designing or selecting a wind energy conversion system for any application. This study examines the wind characteristics for the Waterloo region in Canada based on a data source measured at an elevation 10 m above the ground level over a 5-year period (1999-2003) with the emphasis on the suitability for wind energy technology applications. Characteristics such as annual, seasonal, monthly and diurnal wind speed variations and wind direction variations are examined. Wind speed data reveal that the windy months in Waterloo are from November to April, defined as the Cold Season in this study, with February being the windiest month. It is helpful that the high heating demand in the Cold Season coincides with the windy season. Analysis shows that the day time is the windy time, with 2 p.m. in the afternoon being the windiest moment. Moreover, a model derived from the maximum entropy principle (MEP) is applied to determine the diurnal, monthly, seasonal and yearly wind speed frequency distributions, and the corresponding Lagrangian parameters are determined. Based on these wind speed distributions, this study quantifies the available wind energy potential to provide practical information for the application of wind energy in this area. The yearly average wind power density is 105 W/m 2 . The day and night time wind power density in the Cold Season is 180 and 111 W/m 2 , respectively

  5. Measuring tropospheric wind with microwave sounders

    Science.gov (United States)

    Lambrigtsen, B.; Su, H.; Turk, J.; Hristova-Veleva, S. M.; Dang, V. T.

    2017-12-01

    In its 2007 "Decadal Survey" of earth science missions for NASA the U.S. National Research Council recommended that a Doppler wind lidar be developed for a three-dimensional tropospheric winds mission ("3D-Winds"). The technology required for such a mission has not yet been developed, and it is expected that the next Decadal Survey, planned to be released by the end of 2017, will put additional emphasis on the still pressing need for wind measurements from space. The first Decadal Survey also called for a geostationary microwave sounder (GMS) on a Precipitation and All-weather Temperature and Humidity (PATH) mission, which could be used to measure wind from space. Such a sounder, the Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR), has been developed at the Jet Propulsion Laboratory (JPL). The PATH mission has not yet been funded by NASA, but a low-cost subset of PATH, GeoStorm has been proposed as a hosted payload on a commercial communications satellite. Both PATH and GeoStorm would obtain frequent (every 15 minutes of better) measurements of tropospheric water vapor profiles, and they can be used to derive atmospheric motion vector (AMV) wind profiles, even in the presence of clouds. Measurement of wind is particularly important in the tropics, where the atmosphere is largely not in thermal balance and wind estimates cannot generally be derived from temperature and pressure fields. We report on simulation studies of AMV wind vectors derived from a GMS and from a cluster of low-earth-orbiting (LEO) small satellites (e.g., CubeSats). The results of two separate simulation studies are very encouraging and show that a ±2 m/s wind speed precision is attainable, which would satisfy WMO requirements. A GMS observing system in particular, which can be implemented now, would enable significant progress in the study of atmospheric dynamics. Copyright 2017 California Institute of Technology. Government sponsorship acknowledged

  6. Examination of the wind speed limit function in the Rothermel surface fire spread model

    Science.gov (United States)

    Patricia L. Andrews; Miguel G. Cruz; Richard C. Rothermel

    2013-01-01

    The Rothermel surface fire spread model includes a wind speed limit, above which predicted rate of spread is constant. Complete derivation of the wind limit as a function of reaction intensity is given, along with an alternate result based on a changed assumption. Evidence indicates that both the original and the revised wind limits are too restrictive. Wind limit is...

  7. Mapping Winds over Martian Sand Dunes from Ripples and Digital Terrain Models

    Science.gov (United States)

    Johnson, M. B.; Zimbelman, J. R.

    2015-05-01

    Sand dunes preserve wind flow patterns in their ripple formations. DTMs can be used with wind modeling software to simulate wind speed and direction over these dunes. Results can be compared and together offer a more complete picture of recent wind.

  8. Wind power deployment outcomes: How can we account for the differences?

    NARCIS (Netherlands)

    Toke, D.; Breukers, S.; Wolsink, M.

    2008-01-01

    This paper aims to understand different outcomes of implementation of wind power deployment programmes. Geographical variables such as quantity of wind resources are in themselves insufficient to explain patterns of implementation of wind power. To enhance the review of the factors affecting wind

  9. Small wind rising? Is the market for building-mounted wind power about to pick up?

    International Nuclear Information System (INIS)

    Slowe, J.

    2006-01-01

    The potential market for small roof-mounted wind turbines is discussed. Should the technology prove popular, the market would be enormous. Delta Energy and Environment has prepared a study called, Roof Top Wind Turbines: A Product for Mass Markets? At present, the future for roof-mounted wind turbines is unclear: predictions range from little or no market at all to mass installations with a payback period of as little as five years. Several small roof-top turbines are described. A critical factor influencing the efficiency of a roof-mounted wind turbine is the air flow pattern over the roof which may in turn be affected by neighbouring buildings. (author)

  10. Coastal Ohio Wind Project for Reduced Barriers to Deployment of Offshore Wind Energy

    Energy Technology Data Exchange (ETDEWEB)

    Gorsevski, Peter; Afjeh, Abdollah; Jamali, Mohsin; Carroll, Michael

    2014-04-09

    The Coastal Ohio Wind Project was created to establish the viability of wind turbines on the coastal and offshore regions of Northern Ohio. The project’s main goal was to improve operational unit strategies used for environmental impact assessment of offshore turbines on lake wildlife by optimizing and fusing data from the multi-instrument surveillance system and providing an engineering analysis of potential design/operational alternatives for offshore wind turbines. The project also developed a general economic model for offshore WTG deployment to quantify potential revenue losses due to wind turbine shutdown related to ice and avian issues. In a previous phase of this project (Award Number: DE-FG36-06GO86096), we developed a surveillance system that was used to collect different parameters such as passage rates, flight paths, flight directions, and flight altitudes of nocturnal migrating species, movements of birds and bats, and bird calls for assessing patterns and peak passage rates during migration. To derive such parameters we used thermal IR imaging cameras, acoustic recorders, and marine radar Furuno (XANK250), which was coupled with a XIR3000B digitizing card from Russell Technologies and open source radR processing software. The integration yielded a development of different computational techniques and methods, which we further developed and optimized as a combined surveillance system. To accomplish this task we implemented marine radar calibration, optimization of processing parameters, and fusion of the multi-sensor data in order to make inferences about the potential avian targets. The main goal of the data fusion from the multi-sensor environment was aimed at reduction of uncertainties while providing acceptable confidence levels with detailed information about the migration patterns. Another component comprised of an assessment of wind resources in a near lake environment and an investigation of the effectiveness of ice coating materials to

  11. Wind engineering in Africa

    NARCIS (Netherlands)

    Wisse, J.A.; Stigter, C.J.

    2007-01-01

    The International Association for Wind Engineering (IAWE) has very few contacts in Africa, the second-largest continent. This paper reviews important wind-related African issues. They all require data on wind climate, which are very sparse in Africa. Wind engineering in Africa can assist in

  12. Wind energy; Energie eolienne

    Energy Technology Data Exchange (ETDEWEB)

    Vachey, C.

    2000-05-01

    This public information paper presents the wind energy resource in the Languedoc Roussillon region, explains how a wind turbine works, the different types of utilization and the cost of the wind energy. The environmental impacts of the wind energy, on the noise and the landscape, are also discussed. (A.L.B.)

  13. Different pattern of immunoglobulin gene usage by HIV-1 compared to non-HIV-1 antibodies derived from the same infected subject.

    Directory of Open Access Journals (Sweden)

    Liuzhe Li

    Full Text Available A biased usage of immunoglobulin (Ig genes is observed in human anti-HIV-1 monoclonal antibodies (mAbs resulting probably from compensation to reduced usage of the VH3 family genes, while the other alternative suggests that this bias usage is due to antigen requirements. If the antigen structure is responsible for the preferential usage of particular Ig genes, it may have certain implications for HIV vaccine development by the targeting of particular Ig gene-encoded B cell receptors to induce neutralizing anti-HIV-1 antibodies. To address this issue, we have produced HIV-1 specific and non-HIV-1 mAbs from an infected individual and analyzed the Ig gene usage. Green-fluorescence labeled virus-like particles (VLP expressing HIV-1 envelope (Env proteins of JRFL and BaL and control VLPs (without Env were used to select single B cells for the production of 68 recombinant mAbs. Ten of these mAbs were HIV-1 Env specific with neutralizing activity against V3 and the CD4 binding site, as well as non-neutralizing mAbs to gp41. The remaining 58 mAbs were non-HIV-1 Env mAbs with undefined specificities. Analysis revealed that biased usage of Ig genes was restricted only to anti-HIV-1 but not to non-HIV-1 mAbs. The VH1 family genes were dominantly used, followed by VH3, VH4, and VH5 among anti-HIV-1 mAbs, while non-HIV-1 specific mAbs preferentially used VH3 family genes, followed by VH4, VH1 and VH5 families in a pattern identical to Abs derived from healthy individuals. This observation suggests that the biased usage of Ig genes by anti-HIV-1 mAbs is driven by structural requirements of the virus antigens rather than by compensation to any depletion of VH3 B cells due to autoreactive mechanisms, according to the gp120 superantigen hypothesis.

  14. Temperature Effects on the Wind Direction Measurement of 2D Solid Thermal Wind Sensors

    Science.gov (United States)

    Chen, Bei; Zhu, Yan-Qing; Yi, Zhenxiang; Qin, Ming; Huang, Qing-An

    2015-01-01

    For a two-dimensional solid silicon thermal wind sensor with symmetrical structure, the wind speed and direction information can be derived from the output voltages in two orthogonal directions, i.e., the north-south and east-west. However, the output voltages in these two directions will vary linearly with the ambient temperature. Therefore, in this paper, a temperature model to study the temperature effect on the wind direction measurement has been developed. A theoretical analysis has been presented first, and then Finite Element Method (FEM) simulations have been performed. It is found that due to symmetrical structure of the thermal wind sensor, the temperature effects on the output signals in the north-south and east-west directions are highly similar. As a result, the wind direction measurement of the thermal wind sensor is approximately independent of the ambient temperature. The experimental results fit the theoretical analysis and simulation results very well. PMID:26633398

  15. Offshore Wind Farms

    DEFF Research Database (Denmark)

    Lundtang Petersen, Erik; Hasager, Charlotte Bay; Courtney, Michael

    2015-01-01

    The technology behind constructing wind farms offshore began to develop in 1991 when the Vindeby wind farm was installed off the Danish coast (11 Bonus 450 kW turbines). Resource assessment, grid connection, and wind farm operation are significant challenges for offshore wind power just...... concern are the problems associated with locating the turbines close together in a wind farm and the problems of placing several large wind farms in a confined area. The environmental impacts of offshore wind farms are also treated, but not the supply chain, that is, the harbors, the installation vessels...

  16. Extreme winds in the Western North Pacific

    DEFF Research Database (Denmark)

    Ott, Søren

    2006-01-01

    they are at least coherent over time in their imperfections. Applying the the Holland model to the best track data, wind profiles can be assigned along the tracks. Fromthis annual wind speed maxima at any particular point in the region can be derived. The annual maxima, in turn, are fitted to a Gumbel distribution...... using a generalization Abild’s method that allows for data wind collected from multiple positions. Thechoice of this method is justified by a Monte Carlo simulation comparing it to two other methods. The principle output is a map showing fifty year winds in the region. The method is tested against...... observed winds from Philippine synoptic stations and fairagreement is found for observed and predicted 48–year maxima. However, the almost bias–free performance of the model could be fortuitous, since precise definitions of ’windspeed’ in terms averaging time, height above ground and assumed surface...

  17. Accounting for variation in wind deployment between Canadian provinces

    International Nuclear Information System (INIS)

    Ferguson-Martin, Christopher J.; Hill, Stephen D.

    2011-01-01

    Wind energy deployment varies widely across regions and this variation cannot be explained by differences in natural wind resources alone. Evidence suggests that institutional factors beyond physical wind resources can influence the deployment of wind energy systems. Building on the work of , this study takes a historical institutionalist approach to examine the main factors influencing wind energy deployment across four Canadian provinces Canada: Alberta, Manitoba, Ontario and Nova Scotia. Our case studies suggest that wind energy deployment depends upon a combination of indirect causal factors-landscape values, political and social movements, government electricity policy, provincial electricity market structure and incumbent generation technologies and direct causal factors-grid architecture, ownership patterns, renewable incentive programs, planning and approvals processes and stakeholder support and opposition. - Research highlights: → Examines the reasons for variations in wind deployment between Canadian provinces. → Employs a historical institutional approach to the analysis. → Discusses social factors that affect wind deployment across Canadian jurisdictions.

  18. Wind energy availability above gaps in a forest

    DEFF Research Database (Denmark)

    Sogachev, Andrey; Mann, Jakob; Dellwik, Ebba

    2009-01-01

    installation strategies. The canopy-planetary boundary-layer model SCADIS is used to investigate the effect of forest gap size (within the diameter range of 3 - 75 tree heights, h) on wind energy related variables. A wind turbine was assumed with following features: the hub height and rotor diameter of 3.5h......There is a lack of data on availability of wind energy above a forest disturbed by clear-cuts, where a wind energy developer may find an opportunity to install a wind farm. Computational fluid dynamics (CFD) models can provide spatial patterns of wind and turbulence, and help to develop optimal...... and 3h, respectively; this provides the clearance between the rotor and ground of 2h which is similar to the value obtained by the rule of thumb. Spatial variations of wind energy production, the average wind speed shear and cumulative TKE inside the layer of 2h - 5h above the ground around the gaps...

  19. Wind power. [electricity generation

    Science.gov (United States)

    Savino, J. M.

    1975-01-01

    A historical background on windmill use, the nature of wind, wind conversion system technology and requirements, the economics of wind power and comparisons with alternative systems, data needs, technology development needs, and an implementation plan for wind energy are presented. Considerable progress took place during the 1950's. Most of the modern windmills feature a wind turbine electricity generator located directly at the top of their rotor towers.

  20. Superconducting generators for wind turbines: design considerations

    DEFF Research Database (Denmark)

    Mijatovic, Nenad; Abrahamsen, Asger Bech; Træholt, Chresten

    2010-01-01

    The harmonic content of high temperature superconductors (HTS) field winding in air-core high temperature superconducting synchronous machine (HTS SM) has been addressed in order to investigate tendency of HTS SM towards mechanical oscillation and additional loss caused by higher flux harmonic. B....... Both analytical expressions for flux distribution and current sheet distribution have been derived and analyzed. The two main contributors to the AC loss of HTS rotor winding are also identified and their influence addressed on general level....

  1. Quarter-Century Offshore Winds from SSM/I and WRF in the North Sea and South China Sea

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Astrup, Poul; Zhu, Rong

    2016-01-01

    Imager (SSM/I) ocean winds extrapolated from 10 m to 100 m using the Charnock relationship and the logarithmic profile method are compared to Weather Research and Forecasting (WRF) model results in both seas and to in-situ observations in the North Sea. The mean wind speed from SSM/I and WRF differ only...... by 0.1 m/s at Fino1 in the North Sea, while west of Hainan in the South China Sea the difference is 1.0 m/s. Linear regression between SSM/I and WRF winds at 100 m show correlation coefficients squared of 0.75 and 0.67, standard deviation of 1.67 m/s and 1.41 m/s, and mean difference of −0.12 m/s and 0.......83 m/s for Fino1 and Hainan, respectively. The WRF-derived winds overestimate the values in the South China Sea. The inter-annual wind speed variability is estimated as 4.6% and 4.4% based on SSM/I at Fino1 and Hainan, respectively. We find significant changes in the seasonal wind pattern at Fino1...

  2. GPM Ground Validation High Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) OLYMPEX V1a

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Altitude Wind and Rain Airborne Profiler (HIWRAP) instrument is a Doppler radar designed to measure tropospheric winds through deriving Doppler profiles...

  3. CubeSat Constellation Cloud Winds(C3Winds) A New Wind Observing System to Study Mesoscale Cloud Dynamics and Processes

    Science.gov (United States)

    Wu, D. L.; Kelly, M.A.; Yee, J.-H.; Boldt, J.; Demajistre, R.; Reynolds, E. L.; Tripoli, G. J.; Oman, L. D.; Prive, N.; Heidinger, A. K.; hide

    2016-01-01

    The CubeSat Constellation Cloud Winds (C3Winds) is a NASA Earth Venture Instrument (EV-I) concept with the primary objective to better understand mesoscale dynamics and their structures in severe weather systems. With potential catastrophic damage and loss of life, strong extratropical and tropical cyclones (ETCs and TCs) have profound three-dimensional impacts on the atmospheric dynamic and thermodynamic structures, producing complex cloud precipitation patterns, strong low-level winds, extensive tropopause folds, and intense stratosphere-troposphere exchange. Employing a compact, stereo IR-visible imaging technique from two formation-flying CubeSats, C3Winds seeks to measure and map high-resolution (2 km) cloud motion vectors (CMVs) and cloud geometric height (CGH) accurately by tracking cloud features within 5-15 min. Complementary to lidar wind observations from space, the high-resolution wind fields from C3Winds will allow detailed investigations on strong low-level wind formation in an occluded ETC development, structural variations of TC inner-core rotation, and impacts of tropopause folding events on tropospheric ozone and air quality. Together with scatterometer ocean surface winds, C3Winds will provide a more comprehensive depiction of atmosphere-boundary-layer dynamics and interactive processes. Built upon mature imaging technologies and long history of stereoscopic remote sensing, C3Winds provides an innovative, cost-effective solution to global wind observations with potential of increased diurnal sampling via CubeSat constellation.

  4. Profiling the regional wind power fluctuation in China

    International Nuclear Information System (INIS)

    Yu Dayang; Liang Jun; Han Xueshan; Zhao Jianguo

    2011-01-01

    As China starts to build 6 10-GW wind zones in 5 provinces by 2020, accommodating the wind electricity generated from these large wind zones will be a great challenge for the regional grids. Inadequate wind observing data hinders profiling the wind power fluctuations at the regional grid level. This paper proposed a method to assess the seasonal and diurnal wind power patterns based on the wind speed data from the NASA GEOS-5 DAS system, which provides data to the study of climate processes including the long-term estimates of meteorological quantities. The wind power fluctuations for the 6 largest wind zones in China are presented with both the capacity factor and the megawatt wind power output. The measured hourly wind output in a regional grid is compared to the calculating result to test the analyzing model. To investigate the offsetting effect of dispersed wind farms over large regions, the regional correlations of hourly wind power fluctuations are calculated. The result illustrates the different offsetting effects of minute and hourly fluctuations.

  5. Transient LES of an offshore wind turbine

    Directory of Open Access Journals (Sweden)

    L. Vollmer

    2017-12-01

    Full Text Available The estimation of the cost of energy of offshore wind farms has a high uncertainty, which is partly due to the lacking accuracy of information on wind conditions and wake losses inside of the farm. Wake models that aim to reduce the uncertainty by modeling the wake interaction of turbines for various wind conditions need to be validated with measurement data before they can be considered as a reliable estimator. In this paper a methodology that enables a direct comparison of modeled with measured flow data is evaluated. To create the simulation data, a model chain including a mesoscale model, a large-eddy-simulation (LES model and a wind turbine model is used. Different setups are compared to assess the capability of the method to reproduce the wind conditions at the hub height of current offshore wind turbines. The 2-day-long simulation of the ambient wind conditions and the wake simulation generally show good agreements with data from a met mast and lidar measurements, respectively. Wind fluctuations due to boundary layer turbulence and synoptic-scale motions are resolved with a lower representation of mesoscale fluctuations. Advanced metrics to describe the wake shape and development are derived from simulations and measurements but a quantitative comparison proves to be difficult due to the scarcity and the low sampling rate of the available measurement data. Due to the implementation of changing synoptic wind conditions in the LES, the methodology could also be beneficial for case studies of wind farm performance or wind farm control.

  6. Climatic wind tunnel for wind engineering tasks

    Czech Academy of Sciences Publication Activity Database

    Kuznetsov, Sergeii; Pospíšil, Stanislav; Král, Radomil

    2015-01-01

    Roč. 112, 2-B (2015), s. 303-316 ISSN 1897-628X R&D Projects: GA ČR(CZ) GA14-12892S Keywords : climatic tunnel * wind tunnel * atmospheric boundary layer * flow resistance * wind tunnel contraction Subject RIV: JM - Building Engineering https://suw.biblos.pk.edu.pl/resources/i5/i6/i6/i7/i6/r56676/KuznetsovS_ClimaticWind.pdf

  7. Effects of gain-scheduling methods in a classical wind turbine controller on wind turbine aeroservoelastic modes and loads

    DEFF Research Database (Denmark)

    Tibaldi, Carlo; Henriksen, Lars Christian; Hansen, Morten Hartvig

    2014-01-01

    The eects of dierent gain-scheduling methods for a classical wind turbine controller, operating in full load region, on the wind turbine aeroservoelastic modes and loads are investigated in this work. The dierent techniques are derived looking at the physical problem to take into account the chan......The eects of dierent gain-scheduling methods for a classical wind turbine controller, operating in full load region, on the wind turbine aeroservoelastic modes and loads are investigated in this work. The dierent techniques are derived looking at the physical problem to take into account...

  8. Wind Atlas for Egypt

    DEFF Research Database (Denmark)

    Mortensen, Niels Gylling; Said Said, Usama; Badger, Jake

    2006-01-01

    The results of a comprehensive, 8-year wind resource assessment programme in Egypt are presented. The objective has been to provide reliable and accurate wind atlas data sets for evaluating the potential wind power output from large electricityproducing wind turbine installations. The regional wind...... climates of Egypt have been determined by two independent methods: a traditional wind atlas based on observations from more than 30 stations all over Egypt, and a numerical wind atlas based on long-term reanalysis data and a mesoscale model (KAMM). The mean absolute error comparing the two methods is about...... 10% for two large-scale KAMM domains covering all of Egypt, and typically about 5% for several smaller-scale regional domains. The numerical wind atlas covers all of Egypt, whereas the meteorological stations are concentrated in six regions. The Wind Atlas for Egypt represents a significant step...

  9. Wind Atlas for Egypt

    DEFF Research Database (Denmark)

    The results of a comprehensive, 8-year wind resource assessment programme in Egypt are presented. The objective has been to provide reliable and accurate wind atlas data sets for evaluating the potential wind power output from large electricityproducing wind turbine installations. The regional wind...... climates of Egypt have been determined by two independent methods: a traditional wind atlas based on observations from more than 30 stations all over Egypt, and a numerical wind atlas based on long-term reanalysis data and a mesoscale model (KAMM). The mean absolute error comparing the two methods is about...... 10% for two large-scale KAMM domains covering all of Egypt, and typically about 5% for several smaller-scale regional domains. The numerical wind atlas covers all of Egypt, whereas the meteorological stations are concentrated in six regions. The Wind Atlas for Egypt represents a significant step...

  10. Extreme wind estimate for Hornsea wind farm

    DEFF Research Database (Denmark)

    Larsén, Xiaoli Guo

    The purpose of this study is to provide estimation of the 50-year winds of 10 min and 1-s gust value at hub height of 100 m, as well as the design parameter shear exponent for the Hornsea offshore wind farm. The turbulence intensity required for estimating the gust value is estimated using two ap....... The greatest sector-wise extreme winds are from west to northwest. Different data, different periods and different methods have provided a range of values of the 50-year wind and accordingly the gust values, as summarized in Table 15.......The purpose of this study is to provide estimation of the 50-year winds of 10 min and 1-s gust value at hub height of 100 m, as well as the design parameter shear exponent for the Hornsea offshore wind farm. The turbulence intensity required for estimating the gust value is estimated using two...... approaches. One is through the measurements from the wind Doppler lidar, WindCube, which implies serious uncertainty, and the other one is through similarity theory for the atmospheric surface layer where the hub height is likely to belong to during strong storms. The turbulence intensity for storm wind...

  11. On wake modeling, wind-farm gradients, and AEP predictions at the Anholt wind farm

    Directory of Open Access Journals (Sweden)

    A. Peña

    2018-04-01

    Full Text Available We investigate wake effects at the Anholt offshore wind farm in Denmark, which is a farm experiencing strong horizontal wind-speed gradients because of its size and proximity to land. Mesoscale model simulations are used to study the horizontal wind-speed gradients over the wind farm. From analysis of the mesoscale simulations and supervisory control and data acquisition (SCADA, we show that for westerly flow in particular, there is a clear horizontal wind-speed gradient over the wind farm. We also use the mesoscale simulations to derive the undisturbed inflow conditions that are coupled with three commonly used wake models: two engineering approaches (the Park and G. C. Larsen models and a linearized Reynolds-averaged Navier–Stokes approach (Fuga. The effect of the horizontal wind-speed gradient on annual energy production estimates is not found to be critical compared to estimates from both the average undisturbed wind climate of all turbines' positions and the undisturbed wind climate of a position in the middle of the wind farm. However, annual energy production estimates can largely differ when using wind climates at positions that are strongly influenced by the horizontal wind-speed gradient. When looking at westerly flow wake cases, where the impact of the horizontal wind-speed gradient on the power of the undisturbed turbines is largest, the wake models agree with the SCADA fairly well; when looking at a southerly flow case, where the wake losses are highest, the wake models tend to underestimate the wake loss. With the mesoscale-wake model setup, we are also able to estimate the capacity factor of the wind farm rather well when compared to that derived from the SCADA. Finally, we estimate the uncertainty of the wake models by bootstrapping the SCADA. The models tend to underestimate the wake losses (the median relative model error is 8.75 % and the engineering wake models are as uncertain as Fuga. These results are specific for

  12. Uncertainty in the global oceanic CO2 uptake induced by wind forcing: quantification and spatial analysis

    Directory of Open Access Journals (Sweden)

    A. Roobaert

    2018-03-01

    Full Text Available The calculation of the air–water CO2 exchange (FCO2 in the ocean not only depends on the gradient in CO2 partial pressure at the air–water interface but also on the parameterization of the gas exchange transfer velocity (k and the choice of wind product. Here, we present regional and global-scale quantifications of the uncertainty in FCO2 induced by several widely used k formulations and four wind speed data products (CCMP, ERA, NCEP1 and NCEP2. The analysis is performed at a 1°  ×  1° resolution using the sea surface pCO2 climatology generated by Landschützer et al. (2015a for the 1991–2011 period, while the regional assessment relies on the segmentation proposed by the Regional Carbon Cycle Assessment and Processes (RECCAP project. First, we use k formulations derived from the global 14C inventory relying on a quadratic relationship between k and wind speed (k = c ⋅ U102; Sweeney et al., 2007; Takahashi et al., 2009; Wanninkhof, 2014, where c is a calibration coefficient and U10 is the wind speed measured 10 m above the surface. Our results show that the range of global FCO2, calculated with these k relationships, diverge by 12 % when using CCMP, ERA or NCEP1. Due to differences in the regional wind patterns, regional discrepancies in FCO2 are more pronounced than global. These global and regional differences significantly increase when using NCEP2 or other k formulations which include earlier relationships (i.e., Wanninkhof, 1992; Wanninkhof et al., 2009 as well as numerous local and regional parameterizations derived experimentally. To minimize uncertainties associated with the choice of wind product, it is possible to recalculate the coefficient c globally (hereafter called c∗ for a given wind product and its spatio-temporal resolution, in order to match the last evaluation of the global k value. We thus performed these recalculations for each wind product at the resolution and time period of our study

  13. Wind energy technology development and diffusion: a case study of Inner Mongolia, China

    International Nuclear Information System (INIS)

    Zhang Xiliang; Liu Wenqiang; Gu Shuhua; Gan Lin

    2001-01-01

    This article reviews the spread of small household wind generators and the development of wind farms in Inner Mongolia, China with emphasis on policy and institutional perspectives. It analyzes the patterns of wind technology dissemination within social, economic, and environmental contexts. It also discusses international investment and technology transfer relating to wind energy technology. The economics of windfarm development are examined and the role of alternative policy instruments analyzed. Major constraints to wind technology development are identified and relevant policy recommendations suggested. (author)

  14. Wind energy technology development and diffusion: a case study of Inner Mongolia, China

    International Nuclear Information System (INIS)

    Xiliang Zhang; Shuhua Gu; Wenqiang Liu; Lin Gan

    2001-01-01

    This article reviews the spread of small household wind generators and the development of wind farms in Inner Mongolia, China with emphasis on policy and institutional perspectives. It analyses the patterns of wind technology dissemination within social, economic, and environmental contexts. It also discusses international investment and technology transfer relating to wind energy technology. The economics of windfarm development are examined and the role of alternative policy instruments analysed. Major constraints to wind technology development are identified and relevant policy recommendations suggested. (Author)

  15. Climatological attribution of wind power ramp events in East Japan and their probabilistic forecast based on multi-model ensembles downscaled by analog ensemble using self-organizing maps

    Science.gov (United States)

    Ohba, Masamichi; Nohara, Daisuke; Kadokura, Shinji

    2016-04-01

    Severe storms or other extreme weather events can interrupt the spin of wind turbines in large scale that cause unexpected "wind ramp events". In this study, we present an application of self-organizing maps (SOMs) for climatological attribution of the wind ramp events and their probabilistic prediction. The SOM is an automatic data-mining clustering technique, which allows us to summarize a high-dimensional data space in terms of a set of reference vectors. The SOM is applied to analyze and connect the relationship between atmospheric patterns over Japan and wind power generation. SOM is employed on sea level pressure derived from the JRA55 reanalysis over the target area (Tohoku region in Japan), whereby a two-dimensional lattice of weather patterns (WPs) classified during the 1977-2013 period is obtained. To compare with the atmospheric data, the long-term wind power generation is reconstructed by using a high-resolution surface observation network AMeDAS (Automated Meteorological Data Acquisition System) in Japan. Our analysis extracts seven typical WPs, which are linked to frequent occurrences of wind ramp events. Probabilistic forecasts to wind power generation and ramps are conducted by using the obtained SOM. The probability are derived from the multiple SOM lattices based on the matching of output from TIGGE multi-model global forecast to the WPs on the lattices. Since this method effectively takes care of the empirical uncertainties from the historical data, wind power generation and ramp is probabilistically forecasted from the forecasts of global models. The predictability skill of the forecasts for the wind power generation and ramp events show the relatively good skill score under the downscaling technique. It is expected that the results of this study provides better guidance to the user community and contribute to future development of system operation model for the transmission grid operator.

  16. Uncertainty in vertical extrapolation of wind statistics: shear-exponent and WAsP/EWA methods

    DEFF Research Database (Denmark)

    Kelly, Mark C.

    This report provides formulations for estimation of uncertainties involved in vertical extrapolation of winds, as well as the total uncertainty incurred when winds observed at one height are extrapolated to turbine hub height for wind resource assessment. This includes new derivations for uncerta......This report provides formulations for estimation of uncertainties involved in vertical extrapolation of winds, as well as the total uncertainty incurred when winds observed at one height are extrapolated to turbine hub height for wind resource assessment. This includes new derivations...

  17. Offshore wind energy developments

    DEFF Research Database (Denmark)

    Stolpe, Mathias; Buhl, Thomas; Sumer, B. Mutlu

    2014-01-01

    This chapter will give a brief overview of a few of the activities within offshore wind energy research, specifically 1) Support structure optimization, 2) Blade coatings for wind turbines; 3) Scour protection of foundations, 4) Offshore HVDC and 5) Offshore wind services.......This chapter will give a brief overview of a few of the activities within offshore wind energy research, specifically 1) Support structure optimization, 2) Blade coatings for wind turbines; 3) Scour protection of foundations, 4) Offshore HVDC and 5) Offshore wind services....

  18. Wind energy information guide

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    This book is divided into nine chapters. Chapters 1--8 provide background and annotated references on wind energy research, development, and commercialization. Chapter 9 lists additional sources of printed information and relevant organizations. Four indices provide alphabetical access to authors, organizations, computer models and design tools, and subjects. A list of abbreviations and acronyms is also included. Chapter topics include: introduction; economics of using wind energy; wind energy resources; wind turbine design, development, and testing; applications; environmental issues of wind power; institutional issues; and wind energy systems development.

  19. Wind Power Career Chat

    Energy Technology Data Exchange (ETDEWEB)

    2011-01-01

    This document will teach students about careers in the wind energy industry. Wind energy, both land-based and offshore, is expected to provide thousands of new jobs in the next several decades. Wind energy companies are growing rapidly to meet America's demand for clean, renewable, and domestic energy. These companies need skilled professionals. Wind power careers will require educated people from a variety of areas. Trained and qualified workers manufacture, construct, operate, and manage wind energy facilities. The nation will also need skilled researchers, scientists, and engineers to plan and develop the next generation of wind energy technologies.

  20. Arctic wind energy

    International Nuclear Information System (INIS)

    Peltola, E.; Holttinen, H.; Marjaniemi, M.; Tammelin, B.

    1998-01-01

    Arctic wind energy research was aimed at adapting existing wind technologies to suit the arctic climatic conditions in Lapland. Project research work included meteorological measurements, instrument development, development of a blade heating system for wind turbines, load measurements and modelling of ice induced loads on wind turbines, together with the development of operation and maintenance practices in arctic conditions. As a result the basis now exists for technically feasible and economically viable wind energy production in Lapland. New and marketable products, such as blade heating systems for wind turbines and meteorological sensors for arctic conditions, with substantial export potential, have also been developed. (orig.)

  1. Arctic wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Peltola, E. [Kemijoki Oy (Finland); Holttinen, H.; Marjaniemi, M. [VTT Energy, Espoo (Finland); Tammelin, B. [Finnish Meteorological Institute, Helsinki (Finland)

    1998-12-31

    Arctic wind energy research was aimed at adapting existing wind technologies to suit the arctic climatic conditions in Lapland. Project research work included meteorological measurements, instrument development, development of a blade heating system for wind turbines, load measurements and modelling of ice induced loads on wind turbines, together with the development of operation and maintenance practices in arctic conditions. As a result the basis now exists for technically feasible and economically viable wind energy production in Lapland. New and marketable products, such as blade heating systems for wind turbines and meteorological sensors for arctic conditions, with substantial export potential, have also been developed. (orig.)

  2. Wind power today

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    This publication highlights initiatives of the US DOE`s Wind Energy Program. 1997 yearly activities are also very briefly summarized. The first article describes a 6-megawatt wind power plant installed in Vermont. Another article summarizes technical advances in wind turbine technology, and describes next-generation utility and small wind turbines in the planning stages. A village power project in Alaska using three 50-kilowatt turbines is described. Very brief summaries of the Federal Wind Energy Program and the National Wind Technology Center are also included in the publication.

  3. Seasonal Distribution Of Wind In Iran

    Directory of Open Access Journals (Sweden)

    Mokhtar Karami

    2015-08-01

    Full Text Available In this study an attempt has been made to evaluate long-term average variation and fluctuation of Seasonal wind in Iran. For this purpose wind database network was initially formed over Iran. Then data from the base of a 30-year period the daily period of 1011982 to 31122012 was supposed as the basis of the present study and a cell with dimensions of 15 15 km of the studied area was spread. In order to achieve the wind seasonal changes in Iran modern methods of spatial statistics such as Moran global spatial autocorrelation Moran Local insulin index and Hot spots by using of programming in GIS environment were accomplished. The results of this study showed that the spatial distribution of wind in Iran has the cluster pattern. In the meantime based on Moran local index and Hot spots wind patterns in the South South-East East South West and North West have spatial autocorrelation positive pattern and parts of the Caspian Sea coast north and center of the country have negative spatial autocorrelation. During the study period a large part of the country almost half of the total area had a significant pattern or spatial autocorrelation.

  4. Operation and Equivalent Loads of Wind Turbines in Large Wind Farms

    Science.gov (United States)

    Andersen, Soren Juhl; Sorensen, Jens Norkaer; Mikkelsen, Robert Flemming

    2017-11-01

    Wind farms continue to grow in size and as the technology matures, the design of wind farms move towards including dynamic effects besides merely annual power production estimates. The unsteady operation of wind turbines in large wind farms has been modelled with EllipSys3D(Michelsen, 1992, and Sørensen, 1995) for a number of different scenarios using a fully coupled large eddy simulations(LES) and aero-elastic framework. The turbines are represented in the flow fields using the actuator line method(Sørensen and Shen, 2002), where the aerodynamic forces and deflections are derived from an aero-elastic code, Flex5(Øye, 1996). The simulations constitute a database of full turbine operation in terms of both production and loads for various wind speeds, turbulence intensities, and turbine spacings. The operating conditions are examined in terms of averaged power production and thrust force, as well as 10min equivalent flapwise bending, yaw, and tilt moment loads. The analyses focus on how the performance and loads change throughout a given farm as well as comparing how various input parameters affect the operation and loads of the wind turbines during different scenarios. COMWIND(Grant 2104-09- 067216/DSF), Nordic Consortium on Optimization and Control of Wind Farms, Eurotech Greentech Wind project, Winds2Loads, and CCA LES. Ressources Granted on SNIC and JESS. The Vestas NM80 turbine has been used.

  5. Study of wind change for the development of loads reduction techniques for the space shuttle

    Science.gov (United States)

    Adelfang, S. I.

    1987-01-01

    Wind change statistics are analyzed for Vandenberg AFB, California (VAFB) and Kennedy Space Center, Florida (KSC). Means and standard deviations of wind component change and vector wind change modulus within 3-9 and 9-16 km altitude bands are tabulated. The contribution to 3.5 hr wind component change by wind perturbations in various wavelength bands is evaluated. Probability distributions of maximum 3.5 hr wind change in an altitude band are presented and a model for wind change at a specified altitude is tested with data derived from six data bases from VAFB and Santa Monica, California.

  6. A New Fault Diagnosis Algorithm for PMSG Wind Turbine Power Converters under Variable Wind Speed Conditions

    Directory of Open Access Journals (Sweden)

    Yingning Qiu

    2016-07-01

    Full Text Available Although Permanent Magnet Synchronous Generator (PMSG wind turbines (WTs mitigate gearbox impacts, they requires high reliability of generators and converters. Statistical analysis shows that the failure rate of direct-drive PMSG wind turbines’ generators and inverters are high. Intelligent fault diagnosis algorithms to detect inverters faults is a premise for the condition monitoring system aimed at improving wind turbines’ reliability and availability. The influences of random wind speed and diversified control strategies lead to challenges for developing intelligent fault diagnosis algorithms for converters. This paper studies open-circuit fault features of wind turbine converters in variable wind speed situations through systematic simulation and experiment. A new fault diagnosis algorithm named Wind Speed Based Normalized Current Trajectory is proposed and used to accurately detect and locate faulted IGBT in the circuit arms. It is compared to direct current monitoring and current vector trajectory pattern approaches. The results show that the proposed method has advantages in the accuracy of fault diagnosis and has superior anti-noise capability in variable wind speed situations. The impact of the control strategy is also identified. Experimental results demonstrate its applicability on practical WT condition monitoring system which is used to improve wind turbine reliability and reduce their maintenance cost.

  7. Evolution of wind towards wind turbine

    NARCIS (Netherlands)

    Giyanani, A.H.; Bierbooms, W.A.A.M.; Van Bussel, G.J.W.

    2015-01-01

    Remote sensing of the atmospheric variables with the use of LiDAR is a relatively new technology field for wind resource assessment in wind energy. The validation of LiDAR measurements and comparisons is of high importance for further applications of the data.

  8. Wind Tunnel Measurements at LM Wind Power

    DEFF Research Database (Denmark)

    Bertagnolio, Franck

    2012-01-01

    The optimization of airfoil profiles specifically designed for wind turbine application was initiated in the late 80’s [67, 68, 30, 15]. The first attempts to reduce airfoil noise for wind turbines made use of airfoil trailing edge serration. Themodification of airfoil shapes targeted at noise...... reduction is more recent. An important effort was produced in this direction within the SIROCCO project. This latter work involved measurements on full size wind turbines and showed that trailing edge serration may proved a viable solution for mitigating wind turbine noise though it has not been implemented...... on commercial wind turbine yet. It should be mentioned here that the attenuation of turbulent inflow noise using wavy leading edge has recently been investigated [55], but this technique has still to be further validated for practical applications. In this paper, it is proposed to optimize an airfoil which...

  9. Spatial mapping and attribution of Wyoming wind turbines, 2012

    Science.gov (United States)

    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).

  10. WIND TURBINE OPERATION PARAMETER CHARACTERISTICS AT A GIVEN WIND SPEED

    Directory of Open Access Journals (Sweden)

    Zdzisław Kamiński

    2014-06-01

    Full Text Available This paper discusses the results of the CFD simulation of the flow around Vertical Axis Wind Turbine rotor. The examined rotor was designed following patent application no. 402214. The turbine operation is characterised by parameters, such as opening angle of blades, power, torque, rotational velocity at a given wind velocity. Those parameters have an impact on the performance of entire assembly. The distribution of forces acting on the working surfaces in the turbine can change, depending on the angle of rotor rotation. Moreover, the resultant force derived from the force acting on the oncoming and leaving blades should be as high as possible. Accordingly, those parameters were individually simulated over time for each blade in three complete rotations. The attempts to improve the performance of the entire system resulted in a new research trend to improve the performance of working turbine rotor blades.

  11. Transcript analyses of stromal cell derived factors (SDFs): SDF-2, SDF-4 and SDF-5 reveal a different pattern of expression and prognostic association in human breast cancer

    OpenAIRE

    Kang, H.; Escudero-Esparza, Astrid; Douglas-Jones, A.; Mansel, Robert Edward; Jiang, Wen G.

    2009-01-01

    Stromal derived factors, SDFs, are a loosely defined group of molecules that may be generated by stromal cells. Two of the stromal derived factors, SDF-1 and SDF-4 belong to the chemokine family. Other SDFs, such as SDF-2 and SDF-5 are not well defined and their biological functions are less known. Although SDF-1 and its receptor have been strongly indicated in the progression of various cancers including breast cancer, little is known with regard to the role of other SDFs in malignant condit...

  12. An evaluation of the WindEye wind lidar

    DEFF Research Database (Denmark)

    Dellwik, Ebba; Sjöholm, Mikael; Mann, Jakob

    Prevision of the wind field by remote sensing wind lidars has the potential to improve the performance of wind turbines. The functionality of a WindEye lidar developed by Windar Photonics A/S (Denmark) for the wind energy market was tested in a two months long field experiment. The WindEye sensor...... with a high accuracy during the whole campaign....

  13. Wind electric power generation

    International Nuclear Information System (INIS)

    Koch, M.K.; Wind, L.; Canter, B.; Moeller, T.

    2001-01-01

    The monthly statistics of wind electric power generation in Denmark are compiled from information given by the owners of the private wind turbines. For each wind turbine the name of the site and of the type of turbine is given, and the power generation data are given for the month in question together with the total production in 1999 and 2000. Also the data of operation start are given. On the map of Denmark the sites of the wind turbines are marked. (CLS)

  14. The Irish Wind Atlas

    Energy Technology Data Exchange (ETDEWEB)

    Watson, R. [Univ. College Dublin, Dept. of Electronic and Electrical Engineering, Dublin (Ireland); Landberg, L. [Risoe National Lab., Meteorology and Wind Energy Dept., Roskilde (Denmark)

    1999-03-01

    The development work on the Irish Wind Atlas is nearing completion. The Irish Wind Atlas is an updated improved version of the Irish section of the European Wind Atlas. A map of the irish wind resource based on a WA{sup s}P analysis of the measured data and station description of 27 measuring stations is presented. The results of previously presented WA{sup s}P/KAMM runs show good agreement with these results. (au)

  15. Turbulence and wind turbines

    DEFF Research Database (Denmark)

    Brand, Arno J.; Peinke, Joachim; Mann, Jakob

    2011-01-01

    The nature of turbulent flow towards, near and behind a wind turbine, the effect of turbulence on the electricity production and the mechanical loading of individual and clustered wind turbines, and some future issues are discussed.......The nature of turbulent flow towards, near and behind a wind turbine, the effect of turbulence on the electricity production and the mechanical loading of individual and clustered wind turbines, and some future issues are discussed....

  16. Detection of Wind Evolution and Lidar Trajectory Optimization for Lidar-Assisted Wind Turbine Control

    Directory of Open Access Journals (Sweden)

    David Schlipf

    2015-11-01

    Full Text Available Recent developments in remote sensing are offering a promising opportunity to rethink conventional control strategies of wind turbines. With technologies such as lidar, the information about the incoming wind field - the main disturbance to the system - can be made available ahead of time. Initial field testing of collective pitch feedforward control shows, that lidar measurements are only beneficial if they are filtered properly to avoid harmful control action. However, commercial lidar systems developed for site assessment are usually unable to provide a usable signal for real time control. Recent research shows, that the correlation between the measurement of rotor effective wind speed and the turbine reaction can be modeled and that the model can be used to optimize a scan pattern. This correlation depends on several criteria such as turbine size, position of the measurements, measurement volume, and how the wind evolves on its way towards the rotor. In this work the longitudinal wind evolution is identified with the line-of-sight measurements of a pulsed lidar system installed on a large commercial wind turbine. This is done by staring directly into the inflowing wind during operation of the turbine and fitting the coherence between the wind at different measurement distances to an exponential model taking into account the yaw misalignment, limitation to line-of-sight measurements and the pulse volume. The identified wind evolution is then used to optimize the scan trajectory of a scanning lidar for lidar-assisted feedforward control in order to get the best correlation possible within the constraints of the system. Further, an adaptive filer is fitted to the modeled correlation to avoid negative impact of feedforward control because of uncorrelated frequencies of the wind measurement. The main results of the presented work are a first estimate of the wind evolution in front of operating wind turbines and an approach which manufacturers of

  17. Turbulent Flow Inside and Above a Wind Farm: A Wind-Tunnel Study

    Directory of Open Access Journals (Sweden)

    Leonardo P. Chamorro

    2011-11-01

    Full Text Available Wind-tunnel experiments were carried out to better understand boundary layer effects on the flow pattern inside and above a model wind farm under thermally neutral conditions. Cross-wire anemometry was used to characterize the turbulent flow structure at different locations around a 10 by 3 array of model wind turbines aligned with the mean flow and arranged in two different layouts (inter-turbine separation of 5 and 7 rotor diameters in the direction of the mean flow by 4 rotor diameters in its span. Results suggest that the turbulent flow can be characterized in two broad regions. The first, located below the turbine top tip height, has a direct effect on the performance of the turbines. In that region, the turbulent flow statistics appear to reach equilibrium as close as the third to fourth row of wind turbines for both layouts. In the second region, located right above the first one, the flow adjusts slowly. There, two layers can be identified: an internal boundary layer where the flow is affected by both the incoming wind and the wind turbines, and an equilibrium layer, where the flow is fully adjusted to the wind farm. An adjusted logarithmic velocity distribution is observed in the equilibrium layer starting from the sixth row of wind turbines. The effective surface roughness length induced by the wind farm is found to be higher than that predicted by some existing models. Momentum recovery and turbulence intensity are shown to be affected by the wind farm layout. Power spectra show that the signature of the tip vortices, in both streamwise and vertical velocity components, is highly affected by both the relative location in the wind farm and the wind farm layout.

  18. Wind Velocity Vertical Extrapolation by Extended Power Law

    Directory of Open Access Journals (Sweden)

    Zekai Şen

    2012-01-01

    Full Text Available Wind energy gains more attention day by day as one of the clean renewable energy resources. We predicted wind speed vertical extrapolation by using extended power law. In this study, an extended vertical wind velocity extrapolation formulation is derived on the basis of perturbation theory by considering power law and Weibull wind speed probability distribution function. In the proposed methodology not only the mean values of the wind speeds at different elevations but also their standard deviations and the cross-correlation coefficient between different elevations are taken into consideration. The application of the presented methodology is performed for wind speed measurements at Karaburun/Istanbul, Turkey. At this location, hourly wind speed measurements are available for three different heights above the earth surface.

  19. Wind Power Now!

    Science.gov (United States)

    Inglis, David Rittenhouse

    1975-01-01

    The government promotes and heavily subsidizes research in nuclear power plants. Federal development of wind power is slow in comparison even though much research with large wind-electric machines has already been conducted. Unless wind power programs are accelerated it will not become a major energy alternative to nuclear power. (MR)

  20. Power from the Wind

    Science.gov (United States)

    Roman, Harry T.

    2004-01-01

    Wind energy is the fastest-growing renewable energy source in the world. Over the last 20 years, the wind industry has done a very good job of engineering machines, improving materials, and economies of production, and making this energy source a reality. Like all renewable energy forms, wind energy's successful application is site specific. Also,…

  1. Extreme winds in Denmark

    DEFF Research Database (Denmark)

    Kristensen, L.; Rathmann, O.; Hansen, S.O.

    1999-01-01

    Wind-speed data from four sites in Denmark have been analyzed in order to obtain estimates of the basic wind velocity, defined as the 50-year wind speed (ten minute averages) under standard conditions, i.e. 10 meter over a homogeneous terrain with the roughness length 0.05 m. The sites are Skjern...

  2. Extreme winds in Denmark

    DEFF Research Database (Denmark)

    Kristensen, L.; Rathmann, Ole; Hansen, S.O.

    1999-01-01

    Wind-speed data from four sites in Denmark have been analyzed in order to obtain estimates of the basic wind velocity which is defined as the 50-year wind speed under standard conditions, i.e. ten-minute averages at the height 10 m over a uniform terrainwith the roughness length 0.05 m. The sites...

  3. Modelling Wind for Wind Farm Layout Optimization Using Joint Distribution of Wind Speed and Wind Direction

    DEFF Research Database (Denmark)

    Feng, Ju; Shen, Wen Zhong

    2015-01-01

    Reliable wind modelling is of crucial importance for wind farm development. The common practice of using sector-wise Weibull distributions has been found inappropriate for wind farm layout optimization. In this study, we propose a simple and easily implementable method to construct joint distribu......Reliable wind modelling is of crucial importance for wind farm development. The common practice of using sector-wise Weibull distributions has been found inappropriate for wind farm layout optimization. In this study, we propose a simple and easily implementable method to construct joint...... quite well in terms of the coefficient of determination R-2. Then, the best of these joint distributions is used in the layout optimization of the Horns Rev 1 wind farm and the choice of bin sizes for wind speed and wind direction is also investigated. It is found that the choice of bin size for wind...... direction is especially critical for layout optimization and the recommended choice of bin sizes for wind speed and wind direction is finally presented....

  4. Wind and Yaw correlation

    DEFF Research Database (Denmark)

    Federici, Paolo; Kock, Carsten Weber

    The report describes measurements carried out on a given turbine and period. The measurements are carried out in accordance to Ref. [1]. A comparison between wind speed and wind direction on the met mast and nacelle wind speed and yaw direction is made in accordance to Ref. [2] and the results...... are presented on graphs and in a table....

  5. Wind power soars

    Energy Technology Data Exchange (ETDEWEB)

    Flavin, C. [Worldwatch Inst., Washington, DC (United States)

    1996-12-31

    Opinions on the world market for wind power are presented in this paper. Some data for global wind power generating capacity are provided. European and other markets are discussed individually. Estimated potential for wind power is given for a number of countries. 3 figs.

  6. Wind power outlook 2006

    Energy Technology Data Exchange (ETDEWEB)

    anon.

    2006-04-15

    This annual brochure provides the American Wind Energy Association's up-to-date assessment of the wind industry in the United States. This 2006 general assessment shows positive signs of growth, use and acceptance of wind energy as a vital component of the U.S. energy mix.

  7. Wind and Yaw correlation

    DEFF Research Database (Denmark)

    Federici, Paolo; Kock, Carsten Weber

    The report describes measurements carried out on a given turbine and period. The measurements are carried out in accordance to Ref. [1]. A comparison between wind speed and wind direction on the met mast and nacelle wind speed and yaw direction is made in accordance to Ref. [2] and the results...

  8. Wind: French revolutions

    International Nuclear Information System (INIS)

    Jones, C.

    2006-01-01

    Despite having the second best wind resources in Europe after the UK, the wind industry in France lags behind its European counterparts with just 6 W of installed wind capacity per person. The electricity market in France is dominated by the state-owned Electricite de France (EdF) and its nuclear power stations. However, smaller renewable generators are now in theory allowed access to the market and France has transposed the EU renewables directive into national law. The French governement has set a target of generating 10,000 MW of renewable capacity by 2010. The announcement of an increased feed-in tariff and the introduction of 'development zones' (ZDEs) which could allow fast-tracking of planning for wind projects are also expected to boost wind projects. But grid access and adminstrative burdens remain major barriers. In addition, French politicians and local authorities remain committed to nuclear, though encouraged by the European Commission, wind is beginning to gain acceptance; some 325 wind farms (representing 1557 MW of capacity) were approved between February 2004 and January 2005. France is now regarded by the international wind energy sector as a target market. One of France's leading independent wind developers and its only listed wind company, Theolia, is expected to be one of the major beneficiaries of the acceleration of activity in France, though other companies are keen to maximise the opportunities for wind. France currently has only one indigenous manufacturer of wind turbines, but foreign suppliers are winning orders

  9. Denmark Wind Energy Programme

    DEFF Research Database (Denmark)

    Shen, Wen Zhong

    2015-01-01

    In this chapter, a summary of some ongoing wind energy projects in Denmark is given. The research topics comprise computational model development, wind turbine (WT) design, low-noise airfoil and blade design, control device development, wake modelling and wind farm layout optimization....

  10. Spatial mapping and attribution of Wyoming wind turbines

    Science.gov (United States)

    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

  11. Trading wind generation from short-term probabilistic forecasts of wind power

    DEFF Research Database (Denmark)

    Pinson, Pierre; Chevallier, Christophe; Kariniotakis, Georges

    2007-01-01

    Due to the fluctuating nature of the wind resource, a wind power producer participating in a liberalized electricity market is subject to penalties related to regulation costs. Accurate forecasts of wind generation are therefore paramount for reducing such penalties and thus maximizing revenue...... participation. Such strategies permit to further increase revenues and thus enhance competitiveness of wind generation compared to other forms of dispatchable generation. This paper formulates a general methodology for deriving optimal bidding strategies based on probabilistic forecasts of wind generation....... Despite the fact that increasing accuracy in spot forecasts may reduce penalties, this paper shows that, if such forecasts are accompanied with information on their uncertainty, i.e., in the form of predictive distributions, then this can be the basis for defining advanced strategies for market...

  12. Wind energy in Mediterranean Basin

    International Nuclear Information System (INIS)

    Gaudiosi, G.

    1991-01-01

    In its examination of wind energy potential in the Mediterranean Basin, this paper provides brief notes on the Basin's geography; indicates power production and demand; describes the area's wind characteristics and wind monitoring activities; illustrates wind velocity distributions; estimates local wind power production potential; reviews the Basin's wind energy marketing situation and each bordering country's wind energy programs; surveys installed wind energy farms; and assesses national research and commercialization efforts

  13. Field investigation of a wake structure downwind of a VANT (Vertical-Axis Wind Turbine) in a wind farm array

    Science.gov (United States)

    Liu, H. T.; Buck, J. W.; Germain, A. C.; Hinchee, M. E.; Solt, T. S.; Leroy, G. M.; Srnsky, R. A.

    1988-09-01

    The effects of upwind turbine wakes on the performance of a FloWind 17-m vertical-axis wind turbine (VAWT) were investigated through a series of field experiments conducted at the FloWind wind farm on Cameron Ridge, Tehachapi, California. From the field measurements, we derived the velocity and power/energy deficits under various turbine on/off configurations. Much information was provided to characterize the structure of VAWT wakes and to assess their effects on the performance of downwind turbines. A method to estimate the energy deficit was developed based on the measured power deficit and the wind speed distributions. This method may be adopted for other turbine types and sites. Recommendations are made for optimizing wind farm design and operations, as well as for wind energy management.

  14. Offshore wind resource estimation for wind energy

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Badger, Merete; Mouche, A.

    2010-01-01

    Satellite remote sensing from active and passive microwave instruments is used to estimate the offshore wind resource in the Northern European Seas in the EU-Norsewind project. The satellite data include 8 years of Envisat ASAR, 10 years of QuikSCAT, and 23 years of SSM/I. The satellite observati......Satellite remote sensing from active and passive microwave instruments is used to estimate the offshore wind resource in the Northern European Seas in the EU-Norsewind project. The satellite data include 8 years of Envisat ASAR, 10 years of QuikSCAT, and 23 years of SSM/I. The satellite...... observations are compared to selected offshore meteorological masts in the Baltic Sea and North Sea. The overall aim of the Norsewind project is a state-of-the-art wind atlas at 100 m height. The satellite winds are all valid at 10 m above sea level. Extrapolation to higher heights is a challenge. Mesoscale...... modeling of the winds at hub height will be compared to data from wind lidars observing at 100 m above sea level. Plans are also to compare mesoscale model results and satellite-based estimates of the offshore wind resource....

  15. Tidal analysis of Met rocket wind data

    Science.gov (United States)

    Bedinger, J. F.; Constantinides, E.

    1976-01-01

    A method of analyzing Met Rocket wind data is described. Modern tidal theory and specialized analytical techniques were used to resolve specific tidal modes and prevailing components in observed wind data. A representation of the wind which is continuous in both space and time was formulated. Such a representation allows direct comparison with theory, allows the derivation of other quantities such as temperature and pressure which in turn may be compared with observed values, and allows the formation of a wind model which extends over a broader range of space and time. Significant diurnal tidal modes with wavelengths of 10 and 7 km were present in the data and were resolved by the analytical technique.

  16. Automated Boundary Conditions for Wind Tunnel Simulations

    Science.gov (United States)

    Carlson, Jan-Renee

    2018-01-01

    Computational fluid dynamic (CFD) simulations of models tested in wind tunnels require a high level of fidelity and accuracy particularly for the purposes of CFD validation efforts. Considerable effort is required to ensure the proper characterization of both the physical geometry of the wind tunnel and recreating the correct flow conditions inside the wind tunnel. The typical trial-and-error effort used for determining the boundary condition values for a particular tunnel configuration are time and computer resource intensive. This paper describes a method for calculating and updating the back pressure boundary condition in wind tunnel simulations by using a proportional-integral-derivative controller. The controller methodology and equations are discussed, and simulations using the controller to set a tunnel Mach number in the NASA Langley 14- by 22-Foot Subsonic Tunnel are demonstrated.

  17. Indian Ocean surface winds from NCMRWF analysis as compared to ...

    Indian Academy of Sciences (India)

    The quality of the surface wind analysis at the National Centre for Medium Range Weather Forecasts (NCMRWF), New Delhi over the tropical Indian Ocean and its improvement in 2001 are examined by comparing it with in situ buoy measurements and satellite derived surface winds from NASA QuikSCAT satellite (QSCT) ...

  18. Simulation of wake effects between two wind farms

    DEFF Research Database (Denmark)

    Hansen, Kurt Schaldemose; Réthoré, Pierre-Elouan; Palma, Jose

    2015-01-01

    SCADA data, recorded on the downstream wind farm, has been used to identify flow cases with visible clustering effects. The inflow condition is derived from a partly undisturbed wind turbine, due to lack of mast measurements. The SCADA data analysis concludes that centre of the deficit for the do...

  19. Characteristics of surface wind structure of tropical cyclones over the ...

    Indian Academy of Sciences (India)

    the effective utilization of above-mentioned multi- platform-based satellite-derived wind product is very essential to minimize the error in intensity and structure monitoring and forecast. So, a study has been undertaken to analyze the mean character- istics of surface wind distribution and hence the structure of TC based on ...

  20. On the length-scale of the wind profile

    DEFF Research Database (Denmark)

    Pena Diaz, Alfredo; Gryning, Sven-Erik; Mann, Jakob

    2010-01-01

    We present the results of an analysis of simultaneous sonic anemometer observations of wind speed and velocity spectra over flat and homogeneous terrain from 10 up to 160 m height performed at the National Test Station for Wind Turbines at Høvsøre, Denmark. The mixing length, l, derived from the ...

  1. Wind Speed Influences on Marine Aerosol Optical Depth

    Directory of Open Access Journals (Sweden)

    Colin O'Dowd

    2010-01-01

    Full Text Available The Mulcahy (Mulcahy et al., 2008 power-law parameterization, derived at the coastal Atlantic station Mace Head, between clean marine aerosol optical depth (AOD and wind speed is compared to open ocean MODIS-derived AOD versus wind speed. The reported AOD versus wind speed (U was a function of ∼U2. The open ocean MODIS-derived AOD at 550 nm and 860 nm wavelengths, while in good agreement with the general magnitude of the Mulcahy parameterization, follows a power-law with the exponent ranging from 0.72 to 2.47 for a wind speed range of 2–18 m s−1. For the four cases examined, some MODIS cases underestimated AOD while other cases overestimated AOD relative to the Mulcahy scheme. Overall, the results from MODIS support the general power-law relationship of Mulcahy, although some linear cases were also encountered in the MODIS dataset. Deviations also arise between MODIS and Mulcahy at higher wind speeds (>15 m s−1, where MODIS-derived AOD returns lower values as compared to Mulcahy. The results also support the suggestion than wind generated sea spray, under moderately high winds, can rival anthropogenic pollution plumes advecting out into marine environments with wind driven AOD contributing to AOD values approaching 0.3.

  2. Simulation of shear and turbulence impact on wind turbine performance

    DEFF Research Database (Denmark)

    Wagner, Rozenn; Courtney, Michael; Larsen, Torben J.

    of a uniform inflow. Secondly, a similar analysis was done for cases with direction shear. In each case, we derived a standard power curve (function of the wind speed at hub height) and power curves obtained with various definitions of equivalent wind speed in order to reduce the scatter due to shear. Thirdly...

  3. Recent near-surface wind directions inferred from mapping sand ripples on Martian dunes

    Science.gov (United States)

    Liu, Zac Yung-Chun; Zimbelman, James R.

    2015-11-01

    The High Resolution Imaging Science Experiment (HiRISE) provides the capability to obtain orbital images of Mars that are of sufficient resolution to record wind ripple patterns on the surfaces of sand dunes. Ripple patterns provide valuable insights into aeolian erosion and deposition on Earth and Mars. In this study, we develop a systematic mapping procedure to examine sand ripple orientations and create surface process maps to evaluate the recent wind flow over the dunes, as well as the interplay of wind and dune shape. By carefully examining the morphology of the dunes and the location of grainflow and grainfall on dune slipfaces, the recent near-surface wind direction (short-term wind) can be identified. Results from the analysis of three dune fields on the floors of craters west of Hellas Basin show regional N, NW, SE, and ESE wind directions. In the three adjacent dune fields, surface process and flow maps suggest a complex wind pattern. The comparison of short-term wind with dune-constructing wind (long-term wind) shows NE and ESE winds may be persistent at least for the past thousands of years. The results also show that the orientation of inferred wind direction on linear dunes is correlated with the crestlines, which suggest that form-flow interaction may take place. The results of local wind flow documentation should improve Martian surface wind modeling and advance our understanding of sand transport, as well as the rates of sand mobility on both Mars and Earth.

  4. Potentials of wind power

    International Nuclear Information System (INIS)

    Bezrukikh, P.P.; Bezrukikh, P.P.

    2000-01-01

    The ecological advantages of the wind power facilities (WPF) are considered. The possibilities of small WPF, generating the capacity from 40 W up to 10 kW, are discussed. The basic technical data on the national and foreign small WPF are presented. The combined wind power systems are considered. Special attention is paid to the most perspective wind-diesel systems, which provide for all possible versions of the electro-power supply. Useful recommendations and information on the wind power engineering are given for those, who decided to build up a wind facility [ru

  5. Visualization of wind farms

    International Nuclear Information System (INIS)

    Pahlke, T.

    1994-01-01

    With the increasing number of wind energy installations the visual impact of single wind turbines or wind parks is a growing problem for landscape preservation, leading to resistance of local authorities and nearby residents against wind energy projects. To increase acceptance and to form a basis for planning considerations, it is necessary to develop instruments for the visualization of planned wind parks, showing their integration in the landscape. Photorealistic montages and computer animation including video sequences may be helpful in 'getting the picture'. (orig.)

  6. Mapping Wind Energy Controversies

    DEFF Research Database (Denmark)

    Munk, Anders Kristian

    As part the Wind2050 project funded by the Danish Council for Strategic Research we have mapped controversies on wind energy as they unfold online. Specifically we have collected two purpose built datasets, a web corpus containing information from 758 wind energy websites in 6 different countries......, and a smaller social media corpus containing information from 14 Danish wind energy pages on Facebook. These datasets have been analyzed to answer questions like: How do wind proponents and opponents organize online? Who are the central actors? And what are their matters of concern? The purpose of this report...

  7. Wind energy applications guide

    Energy Technology Data Exchange (ETDEWEB)

    anon.

    2001-01-01

    The brochure is an introduction to various wind power applications for locations with underdeveloped transmission systems, from remote water pumping to village electrification. It includes an introductory section on wind energy, including wind power basics and system components and then provides examples of applications, including water pumping, stand-alone systems for home and business, systems for community centers, schools, and health clinics, and examples in the industrial area. There is also a page of contacts, plus two specific example applications for a wind-diesel system for a remote station in Antarctica and one on wind-diesel village electrification in Russia.

  8. Wind energy systems

    International Nuclear Information System (INIS)

    Richardson, R.D.; McNerney, G.M.

    1993-01-01

    Wind energy has matured to a level of development where it is ready to become a generally accepted utility generation technology. A brief discussion of this development is presented, and the operating and design principles are discussed. Alternative designs for wind turbines and the tradeoffs that must be considered are briefly compared. Development of a wind energy system and the impacts on the utility network including frequency stability, voltage stability, and power quality are discussed. The assessment of wind power station economics and the key economic factors that determine the economic viability of a wind power plant are presented

  9. Fault Tolerant Wind Farm Control

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob

    2013-01-01

    In the recent years the wind turbine industry has focused on optimizing the cost of energy. One of the important factors in this is to increase reliability of the wind turbines. Advanced fault detection, isolation and accommodation are important tools in this process. Clearly most faults are dealt...... with best at a wind turbine control level. However, some faults are better dealt with at the wind farm control level, if the wind turbine is located in a wind farm. In this paper a benchmark model for fault detection and isolation, and fault tolerant control of wind turbines implemented at the wind farm...... control level is presented. The benchmark model includes a small wind farm of nine wind turbines, based on simple models of the wind turbines as well as the wind and interactions between wind turbines in the wind farm. The model includes wind and power references scenarios as well as three relevant fault...

  10. Wind Tunnel Measurements at LM Wind Power

    DEFF Research Database (Denmark)

    Bertagnolio, Franck

    2012-01-01

    This section presents the results obtained during the experimental campaign that was conducted in the wind tunnel at LM Wind Power in Lunderskov from August 16th to 26th, 2010. The goal of this study is to validate the so-called TNO trailing edge noise model through measurements of the boundary...... layer turbulence characteristics and the far-field noise generated by the acoustic scattering of the turbulent boundary layer vorticies as they convect past the trailing edge. This campaign was conducted with a NACA0015 airfoil section that was placed in the wind tunnel section. It is equipped with high...

  11. Wind energy in Europe

    International Nuclear Information System (INIS)

    Evans, L.C.

    1992-01-01

    Wind energy should be an important part of the energy supply mix, both at home and abroad, to provide cleaner air and a more stable fuel supply. Not only can wind energy contribute to solving complex global issues, it also can provide a large market for American technological leadership. Even though utilities are paying more attention to wind in a number of states, there are no plans for major installations of wind power plants in the United States. At the same time, European nations have developed aggressive wind energy development programs, including both ambitious research and development efforts and market incentives. Many countries recognize the importance of the clean energy provided by wind technology and are taking steps to promote their fledgling domestic industries. The emphasis on market incentives is starting to pay off. In 1991, European utilities and developers installed nearly twice as much wind capacity as Americans did. In 1992 the gap will be even greater. This article reviews aggressive incentives offered by European governments to boost their domestic wind industries at home and abroad in this almost $1 billion per year market. By offering substantial incentives - considerably more than the American Wind Energy Association (AWEA) is proposing - European nations are ensuring dramatic near-term wind energy development and are taking a major step toward dominating the international wind industry of the 21st century

  12. Influence of vascular endothelial growth factor stimulation and serum deprivation on gene activation patterns of human adipose tissue-derived stromal cells

    DEFF Research Database (Denmark)

    Tratwal, Josefine; Mathiasen, Anders Bruun; Juhl, Morten

    2015-01-01

    stimulation is usually performed under serum deprivation. Potential regenerative molecular mechanisms are numerous and the role of contributing factors is uncertain. The aim of the current study was to investigate the effect of in vitro serum deprivation and VEGF stimulation on gene expression patterns......: Compared to ASCs in complete medium, 190 and 108 genes were significantly altered by serum deprivation and serum deprivation combined with VEGF, respectively. No significant differences in gene expression patterns between serum-deprived ASCs and serum-deprived ASCs combined with VEGF stimulation were found......, matricellular proteins and matrix metalloproteinases in concert, diverge from direct pro-angiogenic paracrine mechanisms as a primary consequence of the used protocol. In vitro serum starvation (with or without VEGF present) appears to favour cardioprotection, extracellular matrix remodelling and blood vessel...

  13. Kansas Wind Energy Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Gruenbacher, Don [Kansas State Univ., Manhattan, KS (United States)

    2015-12-31

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

  14. Wind Turbine Technologies

    DEFF Research Database (Denmark)

    Hansen, Anca Daniela

    2017-01-01

    The wind turbine technology is a very complex technology involving multidisciplinary and broad technical disciplines such as aerodynamics, mechanics, structure dynamics, meteorology as well as electrical engineering addressing the generation, transmission, and integration of wind turbines...... into the power system. Wind turbine technology has matured over the years and become the most promising and reliable renewable energy technology today. It has moved very fast, since the early 1980s, from wind turbines of a few kilowatts to today’s multimegawatt-sized wind turbines [13]. Besides their size......, the design of wind turbines has changed from being convention driven to being optimized driven within the operating regime and market environment. Wind turbine designs have progressed from fixed speed, passive controlled and with drive trains with gearboxes, to become variable speed, active controlled...

  15. Wind tower service lift

    Science.gov (United States)

    Oliphant, David; Quilter, Jared; Andersen, Todd; Conroy, Thomas

    2011-09-13

    An apparatus used for maintaining a wind tower structure wherein the wind tower structure may have a plurality of legs and may be configured to support a wind turbine above the ground in a better position to interface with winds. The lift structure may be configured for carrying objects and have a guide system and drive system for mechanically communicating with a primary cable, rail or other first elongate member attached to the wind tower structure. The drive system and guide system may transmit forces that move the lift relative to the cable and thereby relative to the wind tower structure. A control interface may be included for controlling the amount and direction of the power into the guide system and drive system thereby causing the guide system and drive system to move the lift relative to said first elongate member such that said lift moves relative to said wind tower structure.

  16. Turning to the wind

    Science.gov (United States)

    Sorensen, B.

    1981-10-01

    Consideration is given the economic and technological aspects of both free-stream (horizontal-axis) and cross-wind (vertical-axis) wind energy conversion systems, with attention to operational devices ranging in rotor diameter from 10 to 40 m and in output from 22 to 630 kW. After a historical survey of wind turbine design and applications development, the near-term technical feasibility and economic attractiveness of combined wind/fossil-fueled generator and wind/hydroelectric systems are assessed. Also presented are estimates of wind energy potential extraction in the U.S. and Denmark, the industrial requirements of large-scale implementation, energy storage possibilities such as pumped hydro and flywheels, and cost comparisons of electrical generation by large and small wind systems, coal-fired plants, and light-water fission reactors.

  17. Wind power takes over

    International Nuclear Information System (INIS)

    2002-01-01

    All over the industrialized world concentrated efforts are being made to make wind turbines cover some of the energy demand in the coming years. There is still a long way to go, however, towards a 'green revolution' as far as energy is concerned, for it is quite futile to use wind power for electric heating. The article deals with some of the advantages and disadvantages of developing wind power. In Norway, for instance, environmentalists fear that wind power plants along the coast may have serious consequences for the stocks of white-tailed eagle and golden eagle. An other factor that delays the large-scale application of wind power in Norway is the low price of electricity. Some experts, however, maintain that wind power may already compete with new hydroelectric power of intermediate cost. The investment costs are expected to go down with one third by 2020, when wind power may be the most competitive energy source to utilize

  18. Wind energy conversion system

    Science.gov (United States)

    Longrigg, Paul

    1987-01-01

    The wind energy conversion system includes a wind machine having a propeller connected to a generator of electric power, the propeller rotating the generator in response to force of an incident wind. The generator converts the power of the wind to electric power for use by an electric load. Circuitry for varying the duty factor of the generator output power is connected between the generator and the load to thereby alter a loading of the generator and the propeller by the electric load. Wind speed is sensed electro-optically to provide data of wind speed upwind of the propeller, to thereby permit tip speed ratio circuitry to operate the power control circuitry and thereby optimize the tip speed ratio by varying the loading of the propeller. Accordingly, the efficiency of the wind energy conversion system is maximized.

  19. Effect of the solar wind conditions on the ionospheric equivalent current systems

    Directory of Open Access Journals (Sweden)

    J. J. Zhang

    2013-03-01

    Full Text Available We employ a global magnetohydrodynamics (MHD model, namely the PPMLR-MHD model, to investigate the effect of the solar wind conditions, such as the interplanetary magnetic field (IMF clock angle, southward IMF magnitude and solar wind speed, on the average pattern of the ionospheric equivalent current systems (ECS. A new method to derive ECS from the MHD model is proposed and applied, which takes account of the oblique magnetic field line effects. The model results indicate that when the IMF is due northward, the ECS are very weak while the current over polar region is stronger than the lower latitude; when the IMF rotates southward, the two-cell current system dominates, the eastward electrojet on the afternoon sector and the westward electrojet on the dawn sector increase rapidly while the westward electrojet is stronger than the eastward electrojet. Under southward IMF, the intensity of the westward electrojet and eastward electrojet both increase with the increase of the southward IMF magnitude and solar wind speed, and the increase is very sharp for the westward electrojet. Furthermore, we compare the geomagnetic perturbations on the ground represented by the simulated average ECS with the observation-based statistical results under similar solar wind conditions. It is found that the model results generally match with the observations, but the underestimation of the eastward equivalent current on the dusk sector is the main limitation of the present model.

  20. Aeroelastic instability problems for wind turbines

    DEFF Research Database (Denmark)

    Hansen, Morten Hartvig

    2007-01-01

    This paper deals with the aeroelostic instabilities that have occurred and may still occur for modem commercial wind turbines: stall-induced vibrations for stall-turbines, and classical flutter for pitch-regulated turbines. A review of previous works is combined with derivations of analytical sta...... issues that represent unsolved aeroelostic instability problems for wind turbines. Copyright (c) 2007 John Wiley & Sons, Ltd.......This paper deals with the aeroelostic instabilities that have occurred and may still occur for modem commercial wind turbines: stall-induced vibrations for stall-turbines, and classical flutter for pitch-regulated turbines. A review of previous works is combined with derivations of analytical...... stability limits for typical blade sections that show the fundamental mechanisms of these instabilities. The risk of stall-induced vibrations is mainly related to blade airfoil characteristics, effective direction of blade vibrations and structural damping, whereas the blade tip speed, torsional blade...

  1. The benefit of wind atlases in wind energy and their verification

    Science.gov (United States)

    Bethke, Julia; Kampmeyer, Jens; Mengelkamp, Heinz-Theo

    2014-05-01

    1 INTRODUCTION Wind atlases such as reanalysis data and downscaled data sets are widely used in the wind energy sector, e.g. for long-term correlation of short-term measurements or initial site search. Due to the financial impact of statements derived from wind atlases, their verification is of high importance. Here, different wind atlases are verified in-depth with numerous certified high-quality mast measurements covering a broad range of heights up to 200 m. In contrast to the commonly used weather stations, high masts allow for an evaluation of vertical profiles and atmospheric stability. The following questions will be addressed: What are wind atlases? How well are they performing? Which benefit do wind atlases have in wind energy? 2 APPROACH The performance of commonly used reanalysis data, e.g. MERRA, ERA-Interim, and two data sets downscaled from MERRA reanalysis data is investigated. The first downscaled data set is derived by the mesoscale model MM5 and has a spatial and temporal resolution of 20 km and 10 min, respectively. The second downscaled data set is derived by the WRF model and has a spatial and temporal resolution of 3 km and 10 min, respectively. Certified high-quality measurements of 45 met masts with 160 anemometers covering a range of complexity types, measurement heights between 30 m and 200 m and a time period of 2 years are compared to the wind atlases. Hourly values are analysed. 3 RESULTS The correlation with hourly measurements of wind speed is very good for all data sets. Correlation increases with decreasing terrain complexity. Wind directions are also met very well by all data sets. The frequency distributions of wind speed and therefore, the Weibull parameters are reproduced very well by the downscaled data sets for a broad range of velocities, however underestimating higher velocities. MERRA generally strongly overestimates wind speed. Diurnal and annual cycles as well as vertical profiles are reproduced more accurately by the

  2. TCSP GOES 11 RAPID SCAN WINDS V1

    Data.gov (United States)

    National Aeronautics and Space Administration — Geostationary satellite-derived wind sets have traditionally been generated from image triplets with 30 or 60 minute intervals, and occasionally 15 minute intervals....

  3. GALILEO PROBE DOPPLER WIND EXPERIMENT DATA V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — A total of seven data sets are used to derive the wind profile. These include two trajectory data files (probe and orbiter), three frequency data files including the...

  4. Repetitive model predictive approach to individual pitch control of wind turbines

    DEFF Research Database (Denmark)

    Adegas, Fabiano Daher; Stoustrup, Jakob; Odgaard, Peter Fogh

    2011-01-01

    Wind turbines are inherently exposed to nonuniform wind fields with of wind shear, tower shadow, and possible wake contributions. Asymmetrical aerodynamic rotor loads are a consequence of such periodic, repetitive wind disturbances experienced by the blades. A controller may estimate and use this....... A simulation comparison betweeen the proposed controller and an industry-standard PID controller shows better mitigation of drive-train, blade and tower loads.......Wind turbines are inherently exposed to nonuniform wind fields with of wind shear, tower shadow, and possible wake contributions. Asymmetrical aerodynamic rotor loads are a consequence of such periodic, repetitive wind disturbances experienced by the blades. A controller may estimate and use...... this peculiar disturbance pattern to better attenuate loads and regulate power by controlling the blade pitch angles individually. A novel model predictive (MPC) approach for individual pitch control of wind turbines is proposed in this paper. A repetitive wind disturbance model is incorporated into the MPC...

  5. Second wind in the offshore wind industry

    International Nuclear Information System (INIS)

    Philippe, Edouard; Neyme, Eric; Deboos, Christophe; Villageois, Jean-Remy; Gouverneur, Philippe; Gerard, Bernard; Fournier, Eric; Petrus, Raymond; Lemarquis, David; Dener, Marc; Bivaud, Jean-Pierre; Lemaire, Etienne; Nielsen, Steffen; Lafon, Xavier; Lagandre, Pierre; Nadai, Alain; Pinot de Villechenon, Edouard; Westhues, Markus; Herpers, Frederick; Bisiaux, Christophe; Sperlich, Miriam; Bales, Vincent; Vandenbroeck, Jan; His, Stephane; Derrey, Thierry; Barakat, Georges; Dakyo, Brayima; Carme, Laurent; Petit, Frederic; Ytournel, Sophie; Westhues, Markus; Diller, Armin; Premont, Antoine de; Ruer, Jacques; Lanoe, Frederic; Declercq, Jan; Holmager, Morten; Fidelin, Daniel; Guillet, Jerome; Dudziak, Gregory; Lapierre, Anne; Couturier, Ludovic; Audineau, Jean-Pierre; Rouaix, Eric; De Roeck, Yann-Herve; Quesnel, Louis; Duguet, Benjamin

    2011-06-01

    After several keynote addresses, this publication contains contributions and Power Point presentations proposed during this conference on the development of offshore wind energy. The successive sessions addressed the following issues: the offshore mass production of electricity (examples of Denmark and Belgium, laying and protecting offshore cables), the space, economic and environmental planning (the Danish experience, the role of the Coastal area integrated management, importance of the public debate, so on), the logistics of port infrastructures (simulation tools, example of Bremerhaven, issues related to project management), innovation at the core of industrial strategies (high power wind turbines, the 6 MW Alstom turbine, chain value and innovation in offshore wind energy, the Vertiwing innovating project of a floating wind turbine, a bench test in Charleston, foundations, gravity base structures, the British experience, the Danish experience), the economic and organisational conditions for development, the validation and certification of technologies

  6. Utilization of excess wind power in electric vehicles

    International Nuclear Information System (INIS)

    Hennings, Wilfried; Mischinger, Stefan; Linssen, Jochen

    2013-01-01

    This article describes the assessment of future wind power utilization for charging electric vehicles (EVs) in Germany. The potential wind power production in the model years 2020 and 2030 is derived by extrapolating onshore wind power generation and offshore wind speeds measured in 2007 and 2010 to the installed onshore and offshore wind turbine capacities assumed for 2020 and 2030. The energy consumption of an assumed fleet of 1 million EVs in 2020 and 6 million in 2030 is assessed using detailed models of electric vehicles, real world driving cycles and car usage. It is shown that a substantial part of the charging demand of EVs can be met by otherwise unused wind power, depending on the amount of conventional power required for stabilizing the grid. The utilization of wind power is limited by the charging demand of the cars and the bottlenecks in the transmission grid. -- Highlights: •Wind power available for charging depends on minimum required conventional power (must-run). •With 20 GW must-run power, 50% of charging can be met by excess wind power. •Grid bottlenecks decrease charging met by wind power from 50 % to 30 %. •With zero must-run power, only very little wind power is available for charging

  7. Mesoscale wind fluctuations over Danish waters

    Energy Technology Data Exchange (ETDEWEB)

    Vincent, C.L.

    2010-12-15

    Mesoscale wind fluctuations affect the large scale integration of wind power because they undermine the day-ahead predictability of wind speed and power production, and because they can result in large fluctuations in power generation that must be balanced using reserve power. Large fluctuations in generated power are a particular problem for offshore wind farms because the typically high concentration of turbines within a limited geographical area means that fluctuations can be correlated across large numbers of turbines. Furthermore, organised mesoscale structures that often form over water, such as convective rolls and cellular convection, have length scales of tens of kilometers, and can cause large wind fluctuations on a time scale of around an hour. This thesis is an exploration of the predictability of mesoscale wind fluctuations using observations from the world's first two large offshore wind farms - Horns Rev I in the North Sea, and Nysted in the Baltic Sea. The thesis begins with a climatological analysis of wind fluctuations on time scales of 1-10 hours at the two sites. A novel method for calculating conditional climatologies of spectral information is proposed, based on binning and averaging the time axis of the Hilbert spectrum. Results reveal clear patterns between wind fluctuations and locally observed meteorological conditions. The analysis is expanded by classifying wind fluctuations on time scales of 1-3 hours according to synoptic patterns, satellite pictures and wind classes. Results indicate that cold air outbreaks and open cellular convection are a significant contributor to mesoscale wind variability at Horns Rev. The predictability of mesoscale wind fluctuations is tested by implementing standard statistical models that relate local wind variability to parameters based on a large scale weather analysis. The models show some skill, but only achieve a 15% improvement on a persistence forecast. The possibility of explicitly modelling

  8. Different chronological patterns of appearance of blood derived milk components during mastitis indicate different mechanisms of transfer from blood into milk.

    Science.gov (United States)

    Wellnitz, Olga; Zbinden, Christina; Lüttgenau, Johannes; Bollwein, Heinrich; Bruckmaier, Rupert M

    2015-08-01

    This study aimed to describe chronological patterns of changes of various candidate blood components in milk during the acute phase of a mammary immune response in detail. Eight dairy cows were challenged with Escherichia coli lipopolysaccharide in one udder quarter. Milk from challenged and control quarters and blood samples were taken before, and 1 and 2 h after challenge and then every 15 min until 5 h after challenge. The SCC, serum albumin, immunoglobulin (Ig)G1, IgG2, lactate dehydrogenase (LDH), and L-lactate in milk and blood, and α-lactalbumin in blood were analysed. All selected parameters in milk increased in challenged quarters but did not increase in control quarters. Milk IgG1, IgG2, serum albumin, and LDH were already significantly increased at 2 h after challenge whereas a significant increase of SCC was detectable at 2.75 h and L-lactate was increased at 2.25 h after challenge. In blood L-lactate was increased at 3.75 h after challenge, however, other factors in blood did not change significantly within the 5 h of experiment. In conclusion, the increase of blood components in milk during inflammation follows two different patterns: There is a rapid increase for IgG1, IgG2, or LDH, before the increase of SCC, and their concentrations reach a plateau within 3 h. On the other hand, SCC and L-lactate show a slower but consistent increase not reaching a plateau within 5 h after LPS challenge. L-lactate increases to higher concentrations in milk than in blood. This clearly shows that the increase of blood components follows different patterns and is therefore a controlled and compound-specific process and not exclusively an unspecific type of leakage.

  9. Molecular recognition of AT-DNA sequences by the induced CD pattern of dibenzotetraaza[14]annulene (DBTAA)–adenine derivatives

    OpenAIRE

    Stojković, Marijana Radić; Škugor, Marko; Dudek, Łukasz; Grolik, Jarosław; Eilmes, Julita; Piantanida, Ivo

    2014-01-01

    Summary An investigation of the interactions of two novel and several known DBTAA–adenine conjugates with double-stranded DNA and RNA has revealed the DNA/RNA groove as the dominant binding site, which is in contrast to the majority of previously studied DBTAA analogues (DNA/RNA intercalators). Only DBTAA–propyladenine conjugates revealed the molecular recognition of AT-DNA by an ICD band pattern > 300 nm, whereas significant ICD bands did not appear for other ds-DNA/RNA. A structure–activity...

  10. Innate recognition of bacteria in human milk is mediated by a milk-derived highly expressed pattern recognition receptor, soluble CD14.

    OpenAIRE

    Lab?ta, MO; Vidal, K; Nores, JE; Arias, M; Vita, N; Morgan, BP; Guillemot, JC; Loyaux, D; Ferrara, P; Schmid, D; Affolter, M; Borysiewicz, LK; Donnet-Hughes, A; Schiffrin, EJ

    2000-01-01

    Little is known about innate immunity to bacteria after birth in the hitherto sterile fetal intestine. Breast-feeding has long been associated with a lower incidence of gastrointestinal infections and inflammatory and allergic diseases. We found in human breast milk a 48-kD polypeptide, which we confirmed by mass spectrometry and sequencing to be a soluble form of the bacterial pattern recognition receptor CD14 (sCD14). Milk sCD14 (m-sCD14) concentrations were up to 20-fold higher than serum ...

  11. Innate Recognition of Bacteria in Human Milk Is Mediated by a Milk-Derived Highly Expressed Pattern Recognition Receptor, Soluble Cd14

    OpenAIRE

    Labéta, Mario O.; Vidal, Karine; Nores, Julia E. Rey; Arias, Mauricio; Vita, Natalio; Morgan, B. Paul; Guillemot, Jean Claude; Loyaux, Denis; Ferrara, Pascual; Schmid, Daniel; Affolter, Michael; Borysiewicz, Leszek K.; Donnet-Hughes, Anne; Schiffrin, Eduardo J.

    2000-01-01

    Little is known about innate immunity to bacteria after birth in the hitherto sterile fetal intestine. Breast-feeding has long been associated with a lower incidence of gastrointestinal infections and inflammatory and allergic diseases. We found in human breast milk a 48-kD polypeptide, which we confirmed by mass spectrometry and sequencing to be a soluble form of the bacterial pattern recognition receptor CD14 (sCD14). Milk sCD14 (m-sCD14) concentrations were up to 20-fold higher than serum ...

  12. Observability of wind power

    International Nuclear Information System (INIS)

    Gonot, J.P.; Fraisse, J.L.

    2009-01-01

    The total installed capacity of wind power grows from a few hundred MW at the beginning of 2005 to 3400 MW at the end of 2008. With such a trend, a total capacity of 7000 MW could be reached by 2010. The natural variability of wind power and the difficulty of its predictability require a change in the traditional way of managing supply/demand balance, day-ahead margins and the control of electrical flows. As a consequence, RTE operators should be informed quickly and reliably of the real time output power of wind farms and of its evolvement some hours or days ahead to ensure the reliability of the French electrical power system. French specificities are that wind farms are largely spread over the territory, that 95 % of wind farms have an output power below 10 MW and that they are connected to the distribution network. In this context, new tools were necessary to acquire as soon as possible data concerning wind power. In two years long, RTE set up an observatory of wind production 'IPES system' enable to get an access to the technical characteristics of the whole wind farms, to observe in real time 75 % of the wind generation and to implement a forecast model related to wind generation. (authors)

  13. Financing wind projects

    International Nuclear Information System (INIS)

    Manson, J.

    2006-01-01

    This presentation reviewed some of the partnership opportunities available from GE Energy. GE Energy's ecomagination commitment has promised to double research investment, make customers true partners and reduce greenhouse gases (GHGs). GE Energy's renewable energy team provides a broad range of financial products, and has recently funded 30 wind farms and 2 large solar projects. The company has a diverse portfolio of technology providers and wind regimes, and is increasing their investment in technology. GE Energy recognizes that the wind industry is growing rapidly and has received increased regulatory support that is backed by strong policy and public support. It is expected that Canada will have 3006 wind projects either planned or under construction by 2007. According to GE Energy, successful wind financing is dependent on the location of the site and its wind resources, as well as on the wind developer's power sales agreement. The success of a wind project is also determined by clear financing goals. Site-specific data is needed to determine the quality of wind resource, and off-site data can also be used to provide validation. Proximity to load centres will help to minimize capital costs. Power sales agreements should be based on the project's realistic net capacity factor as well as on the cost of the turbines. The economics of many wind farms is driven by the size of the turbines used. Public consultations are also needed to ensure the success of wind power projects. It was concluded that a good partner will have staying power in the wind power industry, and will understand the time-lines and needs that are peculiar to wind energy developers. refs., tabs., figs

  14. Optimal flights of unmanned aerial vehicles utilizing wind energy

    Science.gov (United States)

    Qi, Ying

    Unmanned aerial vehicles (UAVs) are attractive for a wide range of applications where human presence is dangerous or undesirable. Endurance is an important performance attribute in many UAV missions. While UAV flight endurance can be improved through advances in aerodynamics and engine design, it is equally important to examine operational strategies that can enhance UAV flight endurance and other performance. Wind energy may be used to greatly enhance the flight endurance and performances of Unmanned Aerial Vehicles. Glider pilots commonly use wind to improve range, endurance, or cross-country speed. Compared with a glider, UAVs have ad vantages in utilizing energy in atmosphere. By using proper strategies to extract wind energy in the long-duration flights, a UAV's fuel consumption can be reduced and the performance can be extended. The objective of this research is to investigate the potential benefits of utilizing wind energy and develop optimal wind energy efficient flight trajectories for UAVs. In this thesis, the potential benefits and features of the autonomous soaring flights are studied. UAVs are modelled with point-mass equations of motion. Practical constraints from UAV performance and operational constraints are considered. UAV flights through various wind patterns including wind gradients, thermals and downbursts are studied. Linear wind gradient models, two-dimensional thermal models and three-dimensional vortex ring downburst models are used for the calculation of optimal trajectories. UAV flights through wind fields are formulated as nonlinear optimal control problems that minimize the overall fuel consumption. These problems are converted into parameter optimizations and numerical solutions are obtained for a wide range of wind conditions and UAV performance parameters. Basic features and special flight patterns needed for wind energy flights are discovered. Results indicate that significant improvements in UAV endurance can be achieved by

  15. Model Validation at the 204 MW New Mexico Wind Energy Center: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, E.; Butterfield, C. P.; Ellis, A.; Mechenbier, J.; Hochheimer, J.; Young, R.; Miller, N.; Delmerico, R.; Zavadil, R.; Smith, J. C.

    2006-06-01

    In this paper, we describe methods to derive and validate equivalent models for a large wind farm. FPL Energy's 204-MW New Mexico Wind Energy Center, which is interconnected to the Public Service Company of New Mexico (PNM) transmission system, was used as a case study. The methods described are applicable to any large wind power plant.

  16. Wind stress, curl and vertical velocity in the Bay of Bengal during southwest monsoon, 1984

    Digital Repository Service at National Institute of Oceanography (India)

    Babu, M.T.; Heblekar, A.K.; Murty, C.S.

    Wind distribution observed during southwest monsoon of 1984 has used to derive the mean wind stress for the season at every 1 degree square grid and curl over the Bay of Bengal. Two regions of maximum wind stress are present over the Bay of Bengal...

  17. The necessary distance between large wind farms offshore - study

    DEFF Research Database (Denmark)

    Frandsen, S.; Barthelmie, R.J.; Pryor, S.C.

    2005-01-01

    the new Storpark Analytical Model has been developed and evaluated. As it is often the need for offshore wind farms, the model handles a regular array-geometry with straight rows of wind turbines and equidistantspacing between units in each row and equidistant spacing between rows. Firstly, the case...... with the flow direction being parallel to rows in a rectangular geometry is considered by defining three flow regimes. Secondly, when the flow is not in line withthe main rows, solutions are found for the patterns of wind turbine units emerging corresponding to each wind direction. The model complex...

  18. Molecular recognition of AT-DNA sequences by the induced CD pattern of dibenzotetraaza[14]annulene (DBTAA)–adenine derivatives

    Science.gov (United States)

    Stojković, Marijana Radić; Škugor, Marko; Dudek, Łukasz; Grolik, Jarosław; Eilmes, Julita

    2014-01-01

    Summary An investigation of the interactions of two novel and several known DBTAA–adenine conjugates with double-stranded DNA and RNA has revealed the DNA/RNA groove as the dominant binding site, which is in contrast to the majority of previously studied DBTAA analogues (DNA/RNA intercalators). Only DBTAA–propyladenine conjugates revealed the molecular recognition of AT-DNA by an ICD band pattern > 300 nm, whereas significant ICD bands did not appear for other ds-DNA/RNA. A structure–activity relation for the studied series of compounds showed that the essential structural features for the ICD recognition are a) the presence of DNA-binding appendages (adenine side chain and positively charged side chain) on both DBTAA side chains, and b) the presence of a short propyl linker, which does not support intramolecular aromatic stacking between DBTAA and adenine. The observed AT-DNA-ICD pattern differs from previously reported ss-DNA (poly dT) ICD recognition by a strong negative ICD band at 350 nm, which allows for the dynamic differentiation between ss-DNA (poly dT) and coupled ds-AT-DNA. PMID:25246976

  19. Using Rare Earth Elements (REE) to determine wind-driven soil dispersal from a point source

    Science.gov (United States)

    Although erosion of soil by water is a predictably directional process, the erosion of soil by wind is determined by wind direction on an event-wise basis. The wind-driven dispersal patterns of chemical constituents including natural soil components and anthropogenic contaminants are not well under...

  20. Offshore Wind Power Data

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos Antonio; Litong-Palima, Marisciel; Zeni, Lorenzo

    2012-01-01

    Wind power development scenarios are critical when trying to assess the impact of the demonstration at national and European level. The work described in this report had several objectives. The main objective was to prepare and deliver the proper input necessary for assessing the impact of Demo 4...... – Storm management at national and European level. For that, detailed scenarios for offshore wind power development by 2020 and 2030 were required. The aggregation level that is suitable for the analysis to be done is at wind farm level. Therefore, the scenarios for offshore wind power development offer...... details about the wind farms such as: capacity and coordinates. Since the focus is on the impact of storm fronts passage in Northen Europe, the offshore wind power scenarios were estimated only for the countries at North and Baltic Sea. The sources used are public sources, mentioned in the reference list...

  1. Wind farm economics

    International Nuclear Information System (INIS)

    Milborrow, D.J.

    1995-01-01

    The economics of wind energy are changing rapidly, with improvements in machine performance and increases in size both contributing to reduce costs. These trends are examined and future costs assessed. Although the United Kingdom has regions of high wind speed, these are often in difficult terrain and construction costs are often higher than elsewhere in Europe. Nevertheless, wind energy costs are converging with those of the conventional thermal sources. At present, bank loan periods for wind projects are shorter than for thermal plant, which means that energy prices are higher. Ways of overcoming this problem are explored. It is important, also, to examine the value of wind energy. It is argued that wind energy has a higher value than energy from centralized plant, since it is fed into the low-voltage distribution network. (Author)

  2. Wind power in France

    International Nuclear Information System (INIS)

    Tuille, F.; Courtel, J.

    2015-01-01

    After 3 years of steady decreasing, wind power has resumed growth in 2014 in France and the preliminary figures of 2015 confirm this trend. About 1100 MW were installed in 2014 which was almost twice as much as it was installed the year before. This renaissance is mostly due to the implementation of Brottes' law that eases the installations of wind farms by suppressing the wind power development areas (that were interfering with regional wind power schemes) and by suppressing the minimum number of 5 turbines for any new wind farms. Another important incentive measure was the announcement in January 2015 of a new financial support scheme in replacement of the policy of guaranteed purchase price for the electricity produced. In 2014 the total wind power produced in mainland France reached 17 TW which represented 3.1% of the production of electricity. (A.C.)

  3. Extreme winds in Denmark

    DEFF Research Database (Denmark)

    Kristensen, L.; Rathmann, O.; Hansen, S.O.

    2000-01-01

    ), Kegnaes (7 yr), Sprogo (20 yr), and Tystofte (16 yr). The measured data are wind speed, wind direction, temperature and pressure. The wind records are cleaned for terrain effects by means of WASP (Mortensew ct al., Technical Report I-666 (EN), Riso National Laboratory, 1993. Vol. 2. User's Guide......): assuming geostrophic balance, all the wind-velocity data are transformed to friction velocity u(*) and direction at standard conditions by means of the geostrophic drag law for neutral stratification. The basic wind velocity in 30 degrees sectors are obtained through ranking of the largest values...... of the friction velocity pressure pu(*)(2)/2 taken once every two months. The main conclusion is that the basic wind velocity is significantly larger at the west coast of Jutland (25 +/- 1 m/s) than at any of the other sites (22 +/- 1 m/s). These results are in agreement with those obtained by Jensen and Franck...

  4. Wind turbine state estimation

    DEFF Research Database (Denmark)

    Knudsen, Torben

    2014-01-01

    the results using full-scale wind turbine data. The previously developed methods were based on extended Kalman filtering. This method has several drawback compared to unscented Kalman filtering which has therefore been developed. The unscented Kalman filter was first tested on linear and non-linear test cases......Dynamic inflow is an effect which is normally not included in the models used for wind turbine control design. Therefore, potential improvement from including this effect exists. The objective in this project is to improve the methods previously developed for this and especially to verify...... which was successful. Then the estimation of a wind turbine state including dynamic inflow was tested on a simulated NREL 5MW turbine was performed. This worked perfectly with wind speeds from low to nominal wind speed as the output prediction errors where white. In high wind where the pitch actuator...

  5. Noise from wind turbines

    International Nuclear Information System (INIS)

    Andersen, B.; Jakobsen, J.

    1992-11-01

    Based on a previous project concerning the calculation of the amount of noise emanating from wind turbine arrays, this one examines the subject further by investigating whether there could be significant differences in the amount of noise made by individual wind turbines in an array, and whether the noise is transmitted in varying directions - so that when it is carried in the same direction as the wind blows it would appear to be louder. The aim was also to determine whether the previously used method of calculation lacked precision. It was found that differences in noise niveaux related to individual wind turbines were insignificant and that noise was not so loud when it was not borne in the direction of the wind. It was necessary to change the method of calculation as reckoning should include the influence of the terrain, wind velocity and distance. The measuring and calculation methods are exemplified and the resulting measurements are presented in detail. (AB)

  6. Wind turbine pitch optimization

    DEFF Research Database (Denmark)

    Biegel, Benjamin; Juelsgaard, Morten; Stoustrup, Jakob

    2011-01-01

    We consider a static wind model for a three-bladed, horizontal-axis, pitch-controlled wind turbine. When placed in a wind field, the turbine experiences several mechanical loads, which generate power but also create structural fatigue. We address the problem of finding blade pitch profiles......% compared to any constant pitch profile while sacrificing at most 7% of the maximum attainable output power. Using iterative learning, we show that very similar performance can be achieved by using only load measurements, with no knowledge of the wind field or wind turbine model....... for maximizing power production while simultaneously minimizing fatigue loads. In this paper, we show how this problem can be approximately solved using convex optimization. When there is full knowledge of the wind field, numerical simulations show that force and torque RMS variation can be reduced by over 96...

  7. SERI Wind Energy Program

    Energy Technology Data Exchange (ETDEWEB)

    Noun, R. J.

    1983-06-01

    The SERI Wind Energy Program manages the areas or innovative research, wind systems analysis, and environmental compatibility for the U.S. Department of Energy. Since 1978, SERI wind program staff have conducted in-house aerodynamic and engineering analyses of novel concepts for wind energy conversion and have managed over 20 subcontracts to determine technical feasibility; the most promising of these concepts is the passive blade cyclic pitch control project. In the area of systems analysis, the SERI program has analyzed the impact of intermittent generation on the reliability of electric utility systems using standard utility planning models. SERI has also conducted methodology assessments. Environmental issues related to television interference and acoustic noise from large wind turbines have been addressed. SERI has identified the causes, effects, and potential control of acoustic noise emissions from large wind turbines.

  8. Wind Energy Systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Ma, Ke

    2017-01-01

    Wind power now represents a major and growing source of renewable energy. Large wind turbines (with capacities of up to 6-8 MW) are widely installed in power distribution networks. Increasing numbers of onshore and offshore wind farms, acting as power plants, are connected directly to power...... transmission networks at the scale of hundreds of megawatts. As its level of grid penetration has begun to increase dramatically, wind power is starting to have a significant impact on the operation of the modern grid system. Advanced power electronics technologies are being introduced to improve...... the characteristics of the wind turbines, and make them more suitable for integration into the power grid. Meanwhile, there are some emerging challenges that still need to be addressed. This paper provides an overview and discusses some trends in the power electronics technologies used for wind power generation...

  9. Danish Wind Power

    DEFF Research Database (Denmark)

    Lund, Henrik; Hvelplund, Frede; Østergaard, Poul Alberg

    In a normal wind year, Danish wind turbines generate the equivalent of approx. 20 percent of the Danish electricity demand. This paper argues that only approx. 1 percent of the wind power production is exported. The rest is used to meet domestic Danish electricity demands. The cost of wind power......, a study made by the Danish think tank CEPOS claimed the opposite, i.e. that most of the Danish wind power has been exported in recent years. However, this claim is based on an incorrect interpretation of statistics and a lack of understanding of how the international electricity markets operate...... is paid solely by the electricity consumers and the net influence on consumer prices was as low as 1-3 percent on average in the period 2004-2008. In 2008, the net influence even decreased the average consumer price, although only slightly. In Denmark, 20 percent wind power is integrated by using both...

  10. Wind Turbines Wake Aerodynamics

    DEFF Research Database (Denmark)

    Vermeer, L.; Sørensen, Jens Nørkær; Crespo, A.

    2003-01-01

    The aerodynamics of horizontal axis wind turbine wakes is studied. The contents is directed towards the physics of power extraction by wind turbines and reviews both the near and the far wake region. For the near wake, the survey is restricted to uniform, steady and parallel flow conditions......, thereby excluding wind shear, wind speed and rotor setting changes and yawed conditions. The emphasis is put on measurements in controlled conditions.For the far wake, the survey focusses on both single turbines and wind farm effects, and the experimental and numerical work are reviewed; the main interest...... is to study how the far wake decays downstream, in order to estimate the effect produced in downstream turbines.The article is further restricted to horizontal axis wind turbines and excludes all other types of turbines....

  11. 77 FR 29633 - Alta Wind VII, LLC, Alta Wind IX, LLC, Alta Wind X, LLC, Alta Wind XI, LLC, Alta Wind XII, LLC...

    Science.gov (United States)

    2012-05-18

    ..., Alta Wind XIV, LLC, Alta Wind XV, LLC, Alta Windpower Development, LLC, TGP Development Company, LLC... XIII, LLC, Alta Wind XIV, LLC, Alta Wind XV, LLC, Alta Windpower Development, LLC, and TGP Development...

  12. Spontaneous Pattern Formation Induced by Bénard-Marangoni Convection for Sol-Gel-Derived Titania Dip-Coating Films: Effect of Co-solvents with a High Surface Tension and Low Volatility.

    Science.gov (United States)

    Uchiyama, Hiroaki; Matsui, Tadayuki; Kozuka, Hiromitsu

    2015-11-17

    Evaporation-driven surface tension gradient in the liquid layer often causes the convective flow, i.e., Bénard-Marangoni convection, resulting in the formation of cell-like patterns on the surface. Here, we prepared sol-gel-derived titania films from Ti(OC3H7(i))4 solutions by dip coating and discussed the effect of the addition of co-solvents with a high surface tension and low volatility on the spontaneous pattern formation induced by Bénard-Marangoni convection. Propylene glycol (PG, with a surface tension of 38.6 mN m(-1)) and dipropylene glycol (DPG, with a surface tension of 33.9 mN m(-1)) were added to the coating solutions containing 2-propanol (2-Pr, with a surface tension of 22.9 mN m(-1)) for controlling the evaporation-driven surface tension gradient in the coating layer on a substrate. During dip coating at a substrate withdrawal speed of 50 cm min(-1) in a thermostatic oven at 60 °C, linearly arranged cell-like patterns on a micrometer scale were spontaneously formed on the titania gel films, irrespective of the composition of coating solutions. Such surface patterns remained even after the heat treatment at 200 and 600 °C, where the densification and crystallization of the titania films progressed. The width and height of the cell-like patterns increased with increasing PG and DPG contents in the coating solutions, where the addition of PG resulted in the formation of cells with a larger height than DPG.

  13. Enabling Wind Power Nationwide

    Energy Technology Data Exchange (ETDEWEB)

    Jose Zayas, Michael Derby, Patrick Gilman and Shreyas Ananthan,

    2015-05-01

    Leveraging this experience, the U.S. Department of Energy’s (DOE’s) Wind and Water Power Technologies Office has evaluated the potential for wind power to generate electricity in all 50 states. This report analyzes and quantifies the geographic expansion that could be enabled by accessing higher above ground heights for wind turbines and considers the means by which this new potential could be responsibly developed.

  14. Wind and Yaw correlation

    DEFF Research Database (Denmark)

    Kock, Carsten Weber; Vesth, Allan

    The report describes measurements carried out on a given wind turbine. A comparison between wind speed on the metmast and Nacelle Windspeed are made and the results are presented on graphs and in a table. The data used for the comparison are identical with the data used for the Risø-I-3246(EN......) power curve report. The measurements are carried out in accordance to Ref. [1] and the wind and yaw correlation is analyzed in accordance to Ref. [2]....

  15. Using the satellite-derived normalized difference vegetation index (NDVI) to explain ranging patterns in a lek-breeding antelope: the importance of scale.

    Science.gov (United States)

    Bro-Jørgensen, Jakob; Brown, Molly E; Pettorelli, Nathalie

    2008-11-01

    Lek-breeding species are characterized by a negative association between territorial resource availability and male mating success; however, the impact of resources on the overall distribution patterns of the two sexes in lek systems is not clear. The normalized difference vegetation index (NDVI) has recently emerged as a powerful proxy measure for primary productivity, allowing the links between the distributions of animals and resources to be explored. Using NDVI at four spatial resolutions, we here investigate how the distribution of the two sexes in a lek-breeding population of topi antelopes relates to resource abundance before and during the rut. We found that in the dry season preceding the rut, topi density correlated positively with NDVI at the large, but not the fine, scale. This suggests that before the rut, when resources were relatively scant, topi preferred pastures where green grass was widely abundant. The pattern was less pronounced in males, suggesting that the need for territorial attendance prevents males from tracking resources as freely as females do. During the rut, which occurs in the wet season, both male and female densities correlated negatively with NDVI at the fine scale. At this time, resources were generally plentiful and the results suggest that, rather than by resource maximization, distribution during the rut was determined by benefits of aggregating on relatively resource-poor leks for mating, and possibly antipredator, purposes. At the large scale, no correlation between density and NDVI was found during the rut in either sex, which can be explained by leks covering areas too small to be reflected at this resolution. The study illustrates that when investigating spatial organization, it is important: (1) to choose the appropriate analytic scale, and (2) to consider behavioural as well as strictly ecological factors.

  16. Global patterns of land-atmosphere fluxes of carbon dioxide, latent heat, and sensible heat derived from eddy covariance, satellite, and meteorological observations

    Science.gov (United States)

    Martin, J.; Reichstein, M.

    2012-12-01

    We upscaled FLUXNET observations of carbon dioxide, water and energy fluxes to the global scale using the machine learning technique, Model Tree Ensembles (MTE). We trained MTE to predict site-level gross primary productivity (GPP), terrestrial ecosystem respiration (TER), net ecosystem exchange (NEE), latent energy (LE), and sensible heat (H) based on remote sensing indices, climate and meteorological data, and information on land use. We applied the trained MTEs to generate global flux fields at a 0.5° x 0.5o spatial resolution and a monthly temporal resolution from 1982-2008. Cross-validation analyses revealed good performance of MTE in predicting among-site flux variability with modeling efficiencies (MEf) between 0.64 and 0.84, except for NEE (MEf = 0.32). Performance was also good for predicting seasonal patterns (MEf between 0.84 and 0.89, except for NEE (0.64)). By comparison, predictions of monthly anomalies were weak. Our products are increasingly used to evaluate global land surface models. However, depending on the flux of interest (e.g. gross primary production, terrestrial ecosystem respiration, net ecosystem exchange, evapotranspiration) and the pattern of interest (mean annual map, seasonal cycles, interannual variability, trends) the robustness and uncertainty of these products varies considerably. To avoid pitfalls, this talk also aims at providing an overview of uncertainties associated with these products, and to provide recommendations on the usage for land surface model evaluations. Finally, we present FLUXCOM - an ongoing activity that aims at generating an ensemble of data-driven FLUXNET based products based on diverse approaches.

  17. A Wind Forecasting System for Energy Application

    Science.gov (United States)

    Courtney, Jennifer; Lynch, Peter; Sweeney, Conor

    2010-05-01

    Accurate forecasting of available energy is crucial for the efficient management and use of wind power in the national power grid. With energy output critically dependent upon wind strength there is a need to reduce the errors associated wind forecasting. The objective of this research is to get the best possible wind forecasts for the wind energy industry. To achieve this goal, three methods are being applied. First, a mesoscale numerical weather prediction (NWP) model called WRF (Weather Research and Forecasting) is being used to predict wind values over Ireland. Currently, a gird resolution of 10km is used and higher model resolutions are being evaluated to establish whether they are economically viable given the forecast skill improvement they produce. Second, the WRF model is being used in conjunction with ECMWF (European Centre for Medium-Range Weather Forecasts) ensemble forecasts to produce a probabilistic weather forecasting product. Due to the chaotic nature of the atmosphere, a single, deterministic weather forecast can only have limited skill. The ECMWF ensemble methods produce an ensemble of 51 global forecasts, twice a day, by perturbing initial conditions of a 'control' forecast which is the best estimate of the initial state of the atmosphere. This method provides an indication of the reliability of the forecast and a quantitative basis for probabilistic forecasting. The limitation of ensemble forecasting lies in the fact that the perturbed model runs behave differently under different weather patterns and each model run is equally likely to be closest to the observed weather situation. Models have biases, and involve assumptions about physical processes and forcing factors such as underlying topography. Third, Bayesian Model Averaging (BMA) is being applied to the output from the ensemble forecasts in order to statistically post-process the results and achieve a better wind forecasting system. BMA is a promising technique that will offer calibrated

  18. Wind on the moors

    International Nuclear Information System (INIS)

    Martin, S.

    1992-01-01

    A local town councillor describes the setting up of a wind farm in the south Pennines which plans to sell electricity to the local electricity suppliers. The Coal Clough wind farm will generate sufficient electricity to meet the average demand of 7,500 households and will be managed by a consortium known as Wind Resources Limited linking the construction company and the utilities aiming to buy the electricity produced. While wind power offers many environmental advantages over other means of power generation, local opposition was strong on the basis of the noise produced and clearly visible structures in an area designated as being of outstanding natural beauty. (UK)

  19. Vertical axis wind turbine

    International Nuclear Information System (INIS)

    Obretenov, V.; Tsalov, T.; Chakarov, T.

    2012-01-01

    In recent years, the interest in wind turbines with vertical axis noticeably increased. They have some important advantages: low cost, relatively simple structure, reliable packaging system of wind aggregate long period during which require no maintenance, low noise, independence of wind direction, etc.. The relatively low efficiency, however, makes them applicable mainly for small facilities. The work presents a methodology and software for approximately aerodynamic design of wind turbines of this type, and also analyzed the possibility of improving the efficiency of their workflow

  20. Microsystem Aeromechanics Wind Tunnel

    Data.gov (United States)

    Federal Laboratory Consortium — The Microsystem Aeromechanics Wind Tunnel advances the study of fundamental flow physics relevant to micro air vehicle (MAV) flight and assesses vehicle performance...

  1. Winds of change

    International Nuclear Information System (INIS)

    Palmer, C.; Short, L.

    1998-01-01

    The British countryside is oversubscribed with multiple and often irreconcilable demands. The siting of wind turbines is but one facet of this situation. While the problems of these demands are widely recognised, there is little understanding or agreement on how to resolve them. The 1996 Future Landscape: New Partnerships was an attempt to address this challenge. The use of wind energy as a case study initiated a partnership between contemporary artists and the wind energy industry. It became clear that artists have an important role to play in creating new ways of seeing that will establish wind turbines as new icons for a sustainable future. (Author)

  2. Could wind replace nuclear?

    International Nuclear Information System (INIS)

    2017-01-01

    This article aims at assessing the situation produced by a total replacement of nuclear energy by wind energy, while facing consumption demand at any moment, notably in December. The authors indicate the evolution of the French energy mix during December 2016, and the evolution of the rate between wind energy production and the sum of nuclear and wind energy production during the same month, and then give briefly some elements regarding necessary investments in wind energy to wholly replace nuclear energy. According to them, such a replacement would be ruinous

  3. Climate Wind Power Resources

    Directory of Open Access Journals (Sweden)

    Nana M. Berdzenishvili

    2013-01-01

    Full Text Available Georgia as a whole is characterized by rather rich solar energy resources, which allows to construct alternative power stations in the close proximity to traditional power plants. In this case the use of solar energy is meant. Georgia is divided into 5 zones based on the assessment of wind power resources. The selection of these zones is based on the index of average annual wind speed in the examined area, V> 3 m / s and V> 5 m / s wind speed by the summing duration in the course of the year and V = 0. . . 2 m / s of passive wind by total and continuous duration of these indices per hour.

  4. Wind Energy Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Laurie, Carol

    2017-02-01

    This book takes readers inside the places where daily discoveries shape the next generation of wind power systems. Energy Department laboratory facilities span the United States and offer wind research capabilities to meet industry needs. The facilities described in this book make it possible for industry players to increase reliability, improve efficiency, and reduce the cost of wind energy -- one discovery at a time. Whether you require blade testing or resource characterization, grid integration or high-performance computing, Department of Energy laboratory facilities offer a variety of capabilities to meet your wind research needs.

  5. Vertical axis wind turbines

    Science.gov (United States)

    Krivcov, Vladimir [Miass, RU; Krivospitski, Vladimir [Miass, RU; Maksimov, Vasili [Miass, RU; Halstead, Richard [Rohnert Park, CA; Grahov, Jurij [Miass, RU

    2011-03-08

    A vertical axis wind turbine is described. The wind turbine can include a top ring, a middle ring and a lower ring, wherein a plurality of vertical airfoils are disposed between the rings. For example, three vertical airfoils can be attached between the upper ring and the middle ring. In addition, three more vertical airfoils can be attached between the lower ring and the middle ring. When wind contacts the vertically arranged airfoils the rings begin to spin. By connecting the rings to a center pole which spins an alternator, electricity can be generated from wind.

  6. Wind Power in Georgia

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    Georgia has good wind power potential. Preliminary analyses show that the technical wind power potential in Georgia is good. Meteorological data shows that Georgia has four main areas in Georgia with annual average wind speeds of over 6 m/s and two main areas with 5-6 m/s at 80m. The most promising areas are the high mountain zone of the Great Caucasus, The Kura river valley, The South-Georgian highland and the Southern part of the Georgian Black Sea coast. Czech company Wind Energy Invest has recently signed a Memorandum of Understanding with Georgian authorities for development of the first wind farm in Georgia, a 50MW wind park in Paravani, Southern Georgia, to be completed in 2014. Annual generation is estimated to 170.00 GWh and the investment estimated to 101 million US$. Wind power is suited to balance hydropower in the Georgian electricity sector Electricity generation in Georgia is dominated by hydro power, constituting 88% of total generation in 2009. Limited storage capacity and significant spring and summer peaks in river flows result in an uneven annual generation profile and winter time shortages that are covered by three gas power plants. Wind power is a carbon-free energy source well suited to balance hydropower, as it is available (often strongest) in the winter and can be exported when there is a surplus. Another advantage with wind power is the lead time for the projects; the time from site selection to operation for a wind power park (approximately 2.5 years) is much shorter than for hydro power (often 6-8 years). There is no support system or scheme for renewable sources in Georgia, so wind power has to compete directly with other energy sources and is in most cases more expensive to build than hydro power. In a country and region with rapidly increasing energy demands, the factors described above nevertheless indicate that there is a commercial niche and a role to play for Georgian wind power. Skra: An example of a wind power development

  7. The Solar Wind Environment in Time

    Science.gov (United States)

    Pognan, Quentin; Garraffo, Cecilia; Cohen, Ofer; Drake, Jeremy J.

    2018-03-01

    We use magnetograms of eight solar analogs of ages 30 Myr–3.6 Gyr obtained from Zeeman Doppler Imaging and taken from the literature, together with two solar magnetograms, to drive magnetohydrodynamical wind simulations and construct an evolutionary scenario of the solar wind environment and its angular momentum loss rate. With observed magnetograms of the radial field strength as the only variant in the wind model, we find that a power-law model fitted to the derived angular momentum loss rate against time, t, results in a spin-down relation Ω ∝ t ‑0.51, for angular speed Ω, which is remarkably consistent with the well-established Skumanich law Ω ∝ t ‑0.5. We use the model wind conditions to estimate the magnetospheric standoff distances for an Earth-like test planet situated at 1 au for each of the stellar cases, and to obtain trends of minimum and maximum wind ram pressure and average ram pressure in the solar system through time. The wind ram pressure declines with time as \\overline{{P}ram}}\\propto {t}2/3, amounting to a factor of 50 or so over the present lifetime of the solar system.

  8. Southern Ocean carbon-wind stress feedback

    Science.gov (United States)

    Bronselaer, Ben; Zanna, Laure; Munday, David R.; Lowe, Jason

    2018-02-01

    The Southern Ocean is the largest sink of anthropogenic carbon in the present-day climate. Here, Southern Ocean pCO2 and its dependence on wind forcing are investigated using an equilibrium mixed layer carbon budget. This budget is used to derive an expression for Southern Ocean pCO2 sensitivity to wind stress. Southern Ocean pCO2 is found to vary as the square root of area-mean wind stress, arising from the dominance of vertical mixing over other processes such as lateral Ekman transport. The expression for pCO2 is validated using idealised coarse-resolution ocean numerical experiments. Additionally, we show that increased (decreased) stratification through surface warming reduces (increases) the sensitivity of the Southern Ocean pCO2 to wind stress. The scaling is then used to estimate the wind-stress induced changes of atmospheric pCO_2 in CMIP5 models using only a handful of parameters. The scaling is further used to model the anthropogenic carbon sink, showing a long-term reversal of the Southern Ocean sink for large wind stress strength.

  9. Wind energy status in renewable electrical energy production in Turkey

    International Nuclear Information System (INIS)

    Kaygusuz, Kamil

    2010-01-01

    Main electrical energy sources of Turkey are thermal and hydraulic. Most of the thermal sources are derived from natural gas. Turkey imports natural gas; therefore, decreasing usage of natural gas is very important for both economical and environmental aspects. Because of disadvantages of fossil fuels, renewable energy sources are getting importance for sustainable energy development and environmental protection. Among the renewable sources, Turkey has very high wind energy potential. The estimated wind power capacity of Turkey is about 83,000 MW while only 10,000 MW of it seems to be economically feasible to use. Start 2009, the total installed wind power capacity of Turkey was only 4.3% of its total economical wind power potential (433 MW). However, the strong development of wind energy in Turkey is expected to continue in the coming years. In this study, Turkey's installed electric power capacity, electric energy production is investigated and also Turkey current wind energy status is examined. (author)

  10. Wind turbine power tracking using an improved multimodel quadratic approach.

    Science.gov (United States)

    Khezami, Nadhira; Benhadj Braiek, Naceur; Guillaud, Xavier

    2010-07-01

    In this paper, an improved multimodel optimal quadratic control structure for variable speed, pitch regulated wind turbines (operating at high wind speeds) is proposed in order to integrate high levels of wind power to actively provide a primary reserve for frequency control. On the basis of the nonlinear model of the studied plant, and taking into account the wind speed fluctuations, and the electrical power variation, a multimodel linear description is derived for the wind turbine, and is used for the synthesis of an optimal control law involving a state feedback, an integral action and an output reference model. This new control structure allows a rapid transition of the wind turbine generated power between different desired set values. This electrical power tracking is ensured with a high-performance behavior for all other state variables: turbine and generator rotational speeds and mechanical shaft torque; and smooth and adequate evolution of the control variables. 2010 ISA. Published by Elsevier Ltd. All rights reserved.

  11. The Performance Evaluation of Horizontal Axis Wind Turbine Torque and Mechanical Power Generation Affected by the Number of Blade

    OpenAIRE

    Tan Rodney H. G.; Teow Matthew Y. W.

    2016-01-01

    This paper presents the evaluation of horizontal axis wind turbine torque and mechanical power generation and its relation to the number of blades at a given wind speed. The relationship of wind turbine rotational frequency, tip speed, minimum wind speed, mechanical power and torque related to the number of blades are derived. The purpose of this study is to determine the wind energy extraction efficiency achieved for every increment of blade number. Effective factor is introduced to interpre...

  12. Winds in the high-latitude lower thermosphere: Dependence on the interplanetary magnetic field

    DEFF Research Database (Denmark)

    Richmond, A.D.; Lathuillere, C.; Vennerstrøm, Susanne

    2003-01-01

    of similar to20 hours, a B-y-dependent magnetic-zonal-mean zonal wind generally exists, with maximum wind speeds at 80 magnetic latitude, typically 10 m/s at 105 km, increasing to about 60 m/s at 123 km and 80 m/s at 200 km. In the southern hemisphere the wind is cyclonic when the time-averaged B-y......[1] Wind observations in the summertime lower thermosphere at high southern latitudes, measured by the Wind Imaging Interferometer (WINDII) on the Upper Atmosphere Research Satellite, are statistically analyzed in magnetic coordinates and correlated with the interplanetary magnetic field (IMF......) to determine influences of IMF-dependent ionospheric convection on the winds. Effects are clearly detectable down to 105 km altitude. Above 125 km the wind patterns show considerable similarity with ionospheric convection patterns, and the speed of the averaged neutral wind in the polar cap often exceeds 300 m...

  13. Asynchrony of wind and hydropower resources in Australia

    KAUST Repository

    Gunturu, Udaya

    2017-08-14

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

  14. Asynchrony of wind and hydropower resources in Australia.

    Science.gov (United States)

    Gunturu, Udaya Bhaskar; Hallgren, Willow

    2017-08-18

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

  15. Wind Power Today: (2002) Wind Energy Research Highlights

    Energy Technology Data Exchange (ETDEWEB)

    2003-05-01

    Wind Power Today is an annual publication that provides an overview of the wind research conducted under the U.S. Department of Energy's Wind and Hydropower Technologies Program. The purpose of Wind Power Today is to show how DOE supports wind turbine research and deployment in hopes of furthering the advancement of wind technologies that produce clean, low-cost, reliable energy. Content objectives include: educate readers about the advantages and potential for widespread deployment of wind energy; explain the program's objectives and goals; describe the program's accomplishments in research and application; examine the barriers to widespread deployment; describe the benefits of continued research and development; facilitate technology transfer; and attract cooperative wind energy projects with industry. This 2002 edition of Wind Power Today also includes discussions about wind industry growth in 2002, how DOE is taking advantage of low wind speed regions through advancing technology, and distributed applications for small wind turbines.

  16. High temperature co-axial winding transformers

    Science.gov (United States)

    Divan, Deepakraj M.; Novotny, Donald W.

    1993-01-01

    The analysis and design of co-axial winding transformers is presented. The design equations are derived and the different design approaches are discussed. One of the most important features of co-axial winding transformers is the fact that the leakage inductance is well controlled and can be made low. This is not the case in conventional winding transformers. In addition, the power density of co-axial winding transformers is higher than conventional ones. Hence, using co-axial winding transformers in a certain converter topology improves the power density of the converter. The design methodology used in meeting the proposed specifications of the co-axial winding transformer specifications are presented and discussed. The final transformer design was constructed in the lab. Co-axial winding transformers proved to be a good choice for high power density and high frequency applications. They have a more predictable performance compared with conventional transformers. In addition, the leakage inductance of the transformer can be controlled easily to suit a specific application. For space applications, one major concern is the extraction of heat from power apparatus to prevent excessive heating and hence damaging of these units. Because of the vacuum environment, the only way to extract heat is by using a cold plate. One advantage of co-axial winding transformers is that the surface area available to extract heat from is very large compared to conventional transformers. This stems from the unique structure of the co-axial transformer where the whole core surface area is exposed and can be utilized for cooling effectively. This is a crucial issue here since most of the losses are core losses.

  17. The Crab Pulsar and Relativistic Wind

    Science.gov (United States)

    Coroniti, F. V.

    2017-12-01

    The possibility that the Crab pulsar produces a separated ion-dominated and pair-plasma-dominated, magnetically striped relativistic wind is assessed by rough estimates of the polar cap acceleration of the ion and electron primary beams, the pair production of secondary electrons and positrons, and a simple model of the near-magnetosphere-wind zone. For simplicity, only the orthogonal rotator is considered. Below (above) the rotational equator, ions (electrons) are accelerated in a thin sheath, of order (much less than) the width of the polar cap, to Lorentz factor {γ }i≈ (5{--}10)× {10}7({γ }e≈ {10}7). The accelerating parallel electric field is shorted out by ion-photon (curvature synchrotron) pair production. With strong, but fairly reasonable, assumptions, a set of general magnetic geometry relativistic wind equations is derived and shown to reduce to conservation relations that are similar to those of the wind from a magnetic monopole. The strength of the field-aligned currents carried by the primary beams is determined by the wind’s Alfvén critical point condition to be about eight times the Goldreich-Julian value. A simple model for the transition from the dipole region wind to the asymptotic monopole wind zone is developed. The asymptotic ratio of Poynting flux to ion (pair plasma) kinetic energy flux—the wind {σ }w∞ -parameter—is found to be of order {σ }w∞ ≈ 1/2({10}4). The far wind zone is likely to be complex, with the ion-dominated and pair-plasma-dominated magnetic stripes merging, and the oppositely directed azimuthal magnetic fields annihilating.

  18. The CMEMS L3 scatterometer wind product

    Science.gov (United States)

    de Kloe, Jos; Stoffelen, Ad; Verhoef, Anton

    2017-04-01

    Within the Copernicus Marine Environment Monitoring Service KNMI produces several ocean surface Level 3 wind products. These are daily updated global maps on a regular grid of the available scatterometer wind observations and derived properties, and produced from our EUMETSAT Ocean and Sea Ice Satellite Application Facility (OSI SAF) operational near-real time (NRT) Level 2 swath-based wind products by linear interpolation. Currently available products are the ASCAT on Metop A/B stress equivalent wind vectors, accompanied by ECMWF NWP reference stress equivalent winds from the operational ECMWF NWP model. For each ASCAT scatterometer we provide products on 2 different resolutions, 0.25 and 0.125 degrees. In addition we provide wind stress vectors, and derivative fields (curl and divergence) for stress equivalent wind and wind stress, both for the observations and for the NWP reference winds. New NRT scatterometer products will be made available when additional scatterometer instruments become available, and NRT access to the data can be arranged. We hope OSCAT on the Indian ScatSat-1 satellite will be the the next NRT product to be added. In addition multi-year reprocessing datasets have been made available for ASCAT on Metop-A (1-Jan-2007 up to 31-Mar-2014) and Seawinds on QuikScat (19-Jul-1999 up to 21-Nov-2009). For ASCAT 0.25 and 0.125 degree resolution products are provided, and for QuikScat 0.50 and 0.25 degree resolution products are provided, These products are based on reprocessing the L2 scatterometer products with the latest processing software version, and include reference winds from the ECMWF ERA-Interim model. Additional reprocessing datasets will be added when reprocessed L2 datasets become available. This will hopefully include the ERS-1 and ERS-2 scatterometer datasets (1992-2001), which will extend the available date range back to 1992. These products are available for download through the CMEMS portal website: http://marine.copernicus.eu/

  19. Wind energy - an overview

    International Nuclear Information System (INIS)

    Rangi, R.; Oprisan, M.

    1998-01-01

    The current status of wind technology developments in Canada and around the world was reviewed. Information regarding the level of wind turbine deployment was presented. It was shown that significant effort has been made on the national and international level to increase the capacity of this clean, non-polluting form of energy. Wind energy has become competitive with conventional sources of electricity due to lower cost, higher efficiency and improved reliability of generating equipment. The advantages and disadvantages of wind electricity generating systems and the economics and atmospheric emissions of the systems were described. At present, there is about 23 MW of wind energy generating capacity installed in Canada, but the potential is very large. It was suggested that wind energy could supply as much as 60 per cent of Canada's electricity needs if only one per cent of the land with 'good winds' were covered by wind turbines. Recently, the Canadian government has provided an accelerated capital cost allowance for certain types of renewable energies under the Income Tax Act, and the flow-through share financing legislation to include intangible expenses in certain renewable energy projects has been extended. Besides the support provided to the private sector through tax advantages, the Government also supports renewable energy development by purchasing 'green' energy for its own buildings across the country, and by funding a research and development program to identify and promote application of wind energy technologies, improve its cost effectiveness, and support Canadian wind energy industries with technology development to enhance their competitiveness at home and abroad. Details of the Wind Energy Program, operated by Natural Resources Canada, are described. 3 tabs., 5 figs

  20. Using Graph Components Derived from an Associative Concept Dictionary to Predict fMRI Neural Activation Patterns that Represent the Meaning of Nouns.

    Science.gov (United States)

    Akama, Hiroyuki; Miyake, Maki; Jung, Jaeyoung; Murphy, Brian

    2015-01-01

    In this study, we introduce an original distance definition for graphs, called the Markov-inverse-F measure (MiF). This measure enables the integration of classical graph theory indices with new knowledge pertaining to structural feature extraction from semantic networks. MiF improves the conventional Jaccard and/or Simpson indices, and reconciles both the geodesic information (random walk) and co-occurrence adjustment (degree balance and distribution). We measure the effectiveness of graph-based coefficients through the application of linguistic graph information for a neural activity recorded during conceptual processing in the human brain. Specifically, the MiF distance is computed between each of the nouns used in a previous neural experiment and each of the in-between words in a subgraph derived from the Edinburgh Word Association Thesaurus of English. From the MiF-based information matrix, a machine learning model can accurately obtain a scalar parameter that specifies the degree to which each voxel in (the MRI image of) the brain is activated by each word or each principal component of the intermediate semantic features. Furthermore, correlating the voxel information with the MiF-based principal components, a new computational neurolinguistics model with a network connectivity paradigm is created. This allows two dimensions of context space to be incorporated with both semantic and neural distributional representations.

  1. Using Graph Components Derived from an Associative Concept Dictionary to Predict fMRI Neural Activation Patterns that Represent the Meaning of Nouns.

    Directory of Open Access Journals (Sweden)

    Hiroyuki Akama

    Full Text Available In this study, we introduce an original distance definition for graphs, called the Markov-inverse-F measure (MiF. This measure enables the integration of classical graph theory indices with new knowledge pertaining to structural feature extraction from semantic networks. MiF improves the conventional Jaccard and/or Simpson indices, and reconciles both the geodesic information (random walk and co-occurrence adjustment (degree balance and distribution. We measure the effectiveness of graph-based coefficients through the application of linguistic graph information for a neural activity recorded during conceptual processing in the human brain. Specifically, the MiF distance is computed between each of the nouns used in a previous neural experiment and each of the in-between words in a subgraph derived from the Edinburgh Word Association Thesaurus of English. From the MiF-based information matrix, a machine learning model can accurately obtain a scalar parameter that specifies the degree to which each voxel in (the MRI image of the brain is activated by each word or each principal component of the intermediate semantic features. Furthermore, correlating the voxel information with the MiF-based principal components, a new computational neurolinguistics model with a network connectivity paradigm is created. This allows two dimensions of context space to be incorporated with both semantic and neural distributional representations.

  2. Matrix-Based Activity Pattern Classification as a Novel Method for the Characterization of Enzyme Inhibitors Derived from High-Throughput Screening.

    Science.gov (United States)

    Auld, Douglas S; Jimenez, Marta; Yue, Kimberley; Busby, Scott; Chen, Yu-Chi; Bowes, Scott; Wendel, Greg; Smith, Thomas; Zhang, Ji-Hu

    2016-12-01

    One of the central questions in the characterization of enzyme inhibitors is determining the mode of inhibition (MOI). Classically, this is done with a number of low-throughput methods in which inhibition models are fitted to the data. The ability to rapidly characterize the MOI for inhibitors arising from high-throughput screening in which hundreds to thousands of primary inhibitors may need to be characterized would greatly help in lead selection efforts. Here we describe a novel method for determining the MOI of a compound without the need for curve fitting of the enzyme inhibition data. We provide experimental data to demonstrate the utility of this new high-throughput MOI classification method based on nonparametric analysis of the activity derived from a small matrix of substrate and inhibitor concentrations (e.g., from a 4 S × 4 I matrix). Lists of inhibitors from four different enzyme assays are studied, and the results are compared with the previously described IC 50 -shift method for MOI classification. The MOI results from this method are in good agreement with the known MOI and compare favorably with those from the IC 50 -shift method. In addition, we discuss some advantages and limitations of the method and provide recommendations for utilization of this MOI classification method.

  3. Genome-wide analysis of gene expression during adipogenesis in human adipose-derived stromal cells reveals novel patterns of gene expression during adipocyte differentiation

    Directory of Open Access Journals (Sweden)

    Melvin Anyasi Ambele

    2016-05-01

    Full Text Available We have undertaken an in-depth transcriptome analysis of adipogenesis in human adipose-derived stromal cells (ASCs induced to differentiate into adipocytes in vitro. Gene expression was assessed on days 1, 7, 14 and 21 post-induction and genes differentially expressed numbered 128, 218, 253 and 240 respectively. Up-regulated genes were associated with blood vessel development, leukocyte migration, as well as tumor growth, invasion and metastasis. They also shared common pathways with certain obesity-related pathophysiological conditions. Down-regulated genes were enriched for immune response processes. KLF15, LMO3, FOXO1 and ZBTB16 transcription factors were up-regulated throughout the differentiation process. CEBPA, PPARG, ZNF117, MLXIPL, MMP3 and RORB were up-regulated only on days 14 and 21, which coincide with the maturation of adipocytes and could possibly serve as candidates for controlling fat accumulation and the size of mature adipocytes. In summary, we have identified genes that were up-regulated only on days 1 and 7 or days 14 and 21 that could serve as potential early and late-stage differentiation markers.

  4. 2015 Cost of Wind Energy Review

    Energy Technology Data Exchange (ETDEWEB)

    Moné, Christopher [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hand, Maureen [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bolinger, Mark [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rand, Joseph [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Heimiller, Donna [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ho, Jonathan [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-06-27

    This report uses representative utility-scale projects to estimate the levelized cost of energy (LCOE) for land-based and offshore wind plants in the United States. Data and results detailed here are derived from 2015 commissioned plants. More specifically, analysis detailed here relies on recent market data and state-of-the-art modeling capabilities to maintain an up-to-date understanding of wind energy cost trends and drivers. It is intended to provide insight into current component-level costs as well as a basis for understanding variability in LCOE across the industry. This publication reflects the fifth installment of this annual report.

  5. 2016 Cost of Wind Energy Review

    Energy Technology Data Exchange (ETDEWEB)

    Stehly, Tyler J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Heimiller, Donna M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Scott, George N. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-12-29

    This report uses representative utility-scale projects to estimate the levelized cost of energy (LCOE) for land-based and offshore wind power plants in the United States. Data and results detailed here are derived from 2016 commissioned plants. More specifically, analysis detailed here relies on recent market data and state-of-the-art modeling capabilities to maintain an up-to-date understanding of wind energy cost trends and drivers. This report is intended to provide insight into current component-level costs as well as a basis for understanding variability in LCOE across the country. This publication represents the sixth installment of this annual report.

  6. Use of Satellite-Derived Water Vapor Data to Investigate Northwestward Expansion of North Pacific Subtropical High During 1995 Summer: Westward Propagating Moisture Pattern

    Science.gov (United States)

    Sohn, Byung-Ju; Chung, Hyo-Sang; Kim, Do-Hyung; Perkey, Donald; Robertson, Franklin R.; Smith, Eric A.; Arnold, James E. (Technical Monitor)

    2001-01-01

    The spatial and temporal evolution of the moisture field over the subtropical northwest Pacific during the summer of 1995 is investigated using daily total precipitable water from combined SSM/I-TOVS data and pentad upper tropospheric humidity (UTH) data, in conjunction with NCEP reanalysis data. From analysis of the combined water vapor field, the westward movement of a dry airmass is observed along the 20-30 degrees N latitude zone from near the dateline to the south of Japan throughout the summer of 1995. Extended EOF analysis of total precipitable water reveals that the westward moving pattern takes place in conjunction with an expanding North Pacific subtropical high maintaining an oscillatory component exhibiting a period of some 15-25 days. A concomitant dipole-like oscillating anomalous circulation with approximately a 20-day period between the South China Sea and south of Japan appears to influence the westward expansion of the subtropical high. The analysis also suggests that the fluctuations of the North Pacific high are in response to a local Hadley-type circulation which is induced by westward-moving anomalous convection episodes along 10-20 degrees N.

  7. A DIseAse MOdule Detection (DIAMOnD algorithm derived from a systematic analysis of connectivity patterns of disease proteins in the human interactome.

    Directory of Open Access Journals (Sweden)

    Susan Dina Ghiassian

    2015-04-01

    Full Text Available The observation that disease associated proteins often interact with each other has fueled the development of network-based approaches to elucidate the molecular mechanisms of human disease. Such approaches build on the assumption that protein interaction networks can be viewed as maps in which diseases can be identified with localized perturbation within a certain neighborhood. The identification of these neighborhoods, or disease modules, is therefore a prerequisite of a detailed investigation of a particular pathophenotype. While numerous heuristic methods exist that successfully pinpoint disease associated modules, the basic underlying connectivity patterns remain largely unexplored. In this work we aim to fill this gap by analyzing the network properties of a comprehensive corpus of 70 complex diseases. We find that disease associated proteins do not reside within locally dense communities and instead identify connectivity significance as the most predictive quantity. This quantity inspires the design of a novel Disease Module Detection (DIAMOnD algorithm to identify the full disease module around a set of known disease proteins. We study the performance of the algorithm using well-controlled synthetic data and systematically validate the identified neighborhoods for a large corpus of diseases.

  8. TLR2, TLR4 and CD14 recognize venom-associated molecular patterns from Tityus serrulatus to induce macrophage-derived inflammatory mediators.

    Directory of Open Access Journals (Sweden)

    Karina Furlani Zoccal

    Full Text Available Scorpion sting-induced human envenomation provokes an intense inflammatory reaction. However, the mechanisms behind the recognition of scorpion venom and the induction of mediator release in mammalian cells are unknown. We demonstrated that TLR2, TLR4 and CD14 receptors sense Tityus serrulatus venom (TsV and its major component, toxin 1 (Ts1, to mediate cytokine and lipid mediator production. Additionally, we demonstrated that TsV induces TLR2- and TLR4/MyD88-dependent NF-κB activation and TLR4-dependent and TLR2/MyD88-independent c-Jun activation. Similar to TsV, Ts1 induces MyD88-dependent NF-κB phosphorylation via TLR2 and TLR4 receptors, while c-Jun activation is dependent on neither TLR2 nor TLR4/MyD88. Therefore, we propose the term venom-associated molecular pattern (VAMP to refer to molecules that are introduced into the host by stings and are recognized by PRRs, resulting in inflammation.

  9. Wind power integration : From individual wind turbine to wind park as a power plant

    NARCIS (Netherlands)

    Zhou, Y.

    2009-01-01

    As power capacities of single wind turbine, single wind park and total wind power installation are continuously increasing, the wind power begins to challenge the safety operation of the power system. This thesis focuses on the grid integration aspects such as the dynamic behaviours of wind power

  10. A model of rotationally-sampled wind turbulence for predicting fatigue loads in wind turbines

    Science.gov (United States)

    Spera, David A.

    1995-01-01

    Empirical equations are presented with which to model rotationally-sampled (R-S) turbulence for input to structural-dynamic computer codes and the calculation of wind turbine fatigue loads. These equations are derived from R-S turbulence data which were measured at the vertical-plane array in Clayton, New Mexico. For validation, the equations are applied to the calculation of cyclic flapwise blade loads for the NASA/DOE Mod-2 2.5-MW experimental HAWT's (horizontal-axis wind turbines), and the results compared to measured cyclic loads. Good correlation is achieved, indicating that the R-S turbulence model developed in this study contains the characteristics of the wind which produce many of the fatigue loads sustained by wind turbines. Empirical factors are included which permit the prediction of load levels at specified percentiles of occurrence, which is required for the generation of fatigue load spectra and the prediction of the fatigue lifetime of structures.

  11. Incorporating geostrophic wind information for improved space–time short-term wind speed forecasting

    KAUST Repository

    Zhu, Xinxin

    2014-09-01

    Accurate short-term wind speed forecasting is needed for the rapid development and efficient operation of wind energy resources. This is, however, a very challenging problem. Although on the large scale, the wind speed is related to atmospheric pressure, temperature, and other meteorological variables, no improvement in forecasting accuracy was found by incorporating air pressure and temperature directly into an advanced space-time statistical forecasting model, the trigonometric direction diurnal (TDD) model. This paper proposes to incorporate the geostrophic wind as a new predictor in the TDD model. The geostrophic wind captures the physical relationship between wind and pressure through the observed approximate balance between the pressure gradient force and the Coriolis acceleration due to the Earth’s rotation. Based on our numerical experiments with data from West Texas, our new method produces more accurate forecasts than does the TDD model using air pressure and temperature for 1to 6-hour-ahead forecasts based on three different evaluation criteria. Furthermore, forecasting errors can be further reduced by using moving average hourly wind speeds to fit the diurnal pattern. For example, our new method obtains between 13.9% and 22.4% overall mean absolute error reduction relative to persistence in 2-hour-ahead forecasts, and between 5.3% and 8.2% reduction relative to the best previous space-time methods in this setting.

  12. Wind speed dynamical model in a wind farm

    DEFF Research Database (Denmark)

    Soleimanzadeh, Maryam; Wisniewski, Rafal

    2010-01-01

    , the dynamic model for wind flow will be established. The state space variables are determined based on a fine mesh defined for the farm. The end goal of this method is to assist the development of a dynamical model of a wind farm that can be engaged for better wind farm control strategies.......This paper presents a model for wind speed in a wind farm. The basic purpose of the paper is to calculate approximately the wind speed in the vicinity of each wind turbine in a farm. In this regard the governing equations of flow will be solved for the whole wind farm. In ideal circumstances...

  13. Fixture for winding transformers

    Science.gov (United States)

    Mclyman, M. T.

    1980-01-01

    Bench-mounted fixture assists operator in winding toroid-shaped transformer cores. Toroid is rigidly held in place as wires are looped around. Arrangement frees both hands for rapid winding and untangling of wires that occurs when core is hand held.

  14. Wind turbines and infrasound

    International Nuclear Information System (INIS)

    Howe, B.

    2006-01-01

    This paper provided the results of a study conducted to assess the impacts of wind farm-induced infrasound on nearby residences and human populations. Infrasound occurs at frequencies below those considered as detectable by human hearing. Infrasonic levels caused by wind turbines are often similar to ambient levels of 85 dBG or lower that are caused by wind in the natural environment. This study examined the levels at which infrasound poses a threat to human health or can be considered as an annoyance. The study examined levels of infrasound caused by various types of wind turbines, and evaluated acoustic phenomena and characteristics associated with wind turbines. Results of the study suggested that infrasound near modern wind turbines is typically not perceptible to humans through either auditory or non-auditory mechanisms. However, wind turbines often create an audible broadband noise whose amplitude can be modulated at low frequencies. A review of both Canadian and international studies concluded that infrasound generated by wind turbines should not significantly impact nearby residences or human populations. 17 refs., 2 tabs., 4 figs

  15. NORCOWE Reference Wind Farm

    DEFF Research Database (Denmark)

    Bak, Thomas; Graham, Angus

    2015-01-01

    Offshore wind farms are complex systems, influenced by both the environment (e.g. wind, waves, current and seabed) and the design characteristics of the equipment available for installation (e.g. turbine type, foundations, cabling and distance to shore). These aspects govern the capital and opera...

  16. MWR, Meteor Wind Radars

    Science.gov (United States)

    Roper, R. G.

    1984-01-01

    The requirements of a state of the art meteor wind radar, and acceptable comprises in the interests of economy, are detailed. Design consideration of some existing and proposed radars are discussed. The need for international cooperation in mesopause level wind measurement, such as that being fostered by the MAP GLOBMET (Global Meteor Observations System) project, is emphasized.

  17. Research on wind energy

    CSIR Research Space (South Africa)

    Szewczuk, S

    2012-10-01

    Full Text Available & underlying technologies Ovid: composite man- rated trainer airplane Eskom?s wind farm, Klipheuwel, Cape Town ? CSIR, then DME & City of Cape Town undertook study on large grid connected wind turbines ? included a study tour to Europe. ? Recommended...

  18. Emerging wind energy technologies

    DEFF Research Database (Denmark)

    Rasmussen, Flemming; Grivel, Jean-Claude; Faber, Michael Havbro

    2014-01-01

    This chapter will discuss emerging technologies that are expected to continue the development of the wind sector to embrace new markets and to become even more competitive.......This chapter will discuss emerging technologies that are expected to continue the development of the wind sector to embrace new markets and to become even more competitive....

  19. Aerodynamics of wind turbines

    DEFF Research Database (Denmark)

    Hansen, Martin Otto Laver

    Aerodynamics of Wind Turbines is the established essential text for the fundamental solutions to efficient wind turbine design. Now in its third edition, it has been substantially updated with respect to structural dynamics and control. The new control chapter now includes details on how to design...

  20. Aerodynamics of Wind Turbines

    DEFF Research Database (Denmark)

    Hansen, Martin Otto Laver

    Aerodynamics of Wind Turbines is the established essential text for the fundamental solutions to efficient wind turbine design. Now in its second edition, it has been entirely updated and substantially extended to reflect advances in technology, research into rotor aerodynamics and the structural...

  1. The difficult wind power

    International Nuclear Information System (INIS)

    Groenaas, Sigbjoern

    2005-01-01

    The article presents a brief survey of the conditions for wind power production in Norway and points out that several areas should be well suited. A comparison to Danish climate is made. The wind variations, turbulence problems and regional conditions are discussed

  2. Wind Energy Systems.

    Science.gov (United States)

    Conservation and Renewable Energy Inquiry and Referral Service (DOE), Silver Spring, MD.

    During the 1920s and 1930s, millions of wind energy systems were used on farms and other locations far from utility lines. However, with passage of the Rural Electrification Act in 1939, cheap electricity was brought to rural areas. After that, the use of wind machines dramatically declined. Recently, the rapid rise in fuel prices has led to a…

  3. Fort Carson Wind Resource Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Robichaud, R.

    2012-10-01

    This report focuses on the wind resource assessment, the estimated energy production of wind turbines, and economic potential of a wind turbine project on a ridge in the southeastern portion of the Fort Carson Army base.

  4. Offshore Wind Power

    DEFF Research Database (Denmark)

    Negra, Nicola Barberis

    The aim of the project is to investigate the influence of wind farms on the reliability of power systems. This task is particularly important for large offshore wind farms, because failure of a large wind farm might have significant influence on the balance of the power system, and because offshore...... Carlo simulation is used for these calculations: this method, in spite of an extended computation time, has shown flexibility in performing reliability studies, especially in case of wind generation, and a broad range of results which can be evaluated. The modelling is then extended to the entire power...... system considering conventional power plants, distributed generation based on wind energy and CHP technology as well as the load and transmission facilities. In particular, the different models are used to represent two well-known test systems, the RBTS and the IEEE-RTS, and to calculate...

  5. Urban Wind Energy

    DEFF Research Database (Denmark)

    Beller, Christina

    for the installation of wind turbines in cities, with Copenhagen, DK, as example. Focus is taken on turbine with a swept area of maximum 5m2, since turbines of this size are relatively easy to be integrated in the urban space and are in the financial range for small companies as well as for private persons. Elements......New trends e.g. in architecture and urban planning are to reduce energy needs. Several technologies are employed to achieve this, and one of the technologies, not new as such, is wind energy. Wind turbines are installed in cities, both by companies and private persons on both old and new buildings...... the lower wind energy in cities other factors foster the attractiveness of urban wind energy application, like the demand or wish to reduce CO2 emissions and the possibility to produce energy directly to ones household....

  6. Illinois Wind Workers Group

    Energy Technology Data Exchange (ETDEWEB)

    David G. Loomis

    2012-05-28

    The Illinois Wind Working Group (IWWG) was founded in 2006 with about 15 members. It has grown to over 200 members today representing all aspects of the wind industry across the State of Illinois. In 2008, the IWWG developed a strategic plan to give direction to the group and its activities. The strategic plan identifies ways to address critical market barriers to the further penetration of wind. The key to addressing these market barriers is public education and outreach. Since Illinois has a restructured electricity market, utilities no longer have a strong control over the addition of new capacity within the state. Instead, market acceptance depends on willing landowners to lease land and willing county officials to site wind farms. Many times these groups are uninformed about the benefits of wind energy and unfamiliar with the process. Therefore, many of the project objectives focus on conferences, forum, databases and research that will allow these stakeholders to make well-educated decisions.

  7. Aerodynamics of Wind Turbines

    DEFF Research Database (Denmark)

    Hansen, Martin Otto Laver

    Aerodynamics of Wind Turbines is the established essential text for the fundamental solutions to efficient wind turbine design. Now in its second edition, it has been entirely updated and substantially extended to reflect advances in technology, research into rotor aerodynamics and the structural...... response of the wind turbine structure. Topics covered include increasing mass flow through the turbine, performance at low and high wind speeds, assessment of the extreme conditions under which the turbine will perform and the theory for calculating the lifetime of the turbine. The classical Blade Element...... Momentum method is also covered, as are eigenmodes and the dynamic behavior of a turbine. The new material includes a description of the effects of the dynamics and how this can be modeled in an aeroelastic code, which is widely used in the design and verification of modern wind turbines. Further...

  8. Wind energy centre at Gujarat State, India. Business plan

    International Nuclear Information System (INIS)

    Van Hulle, F.; Jansen, J.C.; Prasad, N.S.; Suresh, R.

    1997-07-01

    The report describes the business plan for the establishment of a Wind Energy Centre in Gujarat. This Wind Energy Center has to provide a reliable delivery of a range of development and technical quality assurance services to the wind energy industry in northern India on the basis of sustained operations and recovery of all operating costs and - contingent on the way the Centre is financed - at least part of the initial investment costs. Core activities of the Wind Energy Centre are: Research and development supporting activities for the wind energy sector; Testing and certification of wind energy equipment; Consultancy, monitoring and information services; and Training courses on wind energy technology and implementation. The wind energy centre aims with its services at a number of customers: the manufacturing industry, wind farm developers and governmental authorities. An exploration of the market for the services of the envisaged wind energy centre shows that the concept is financially viable. A set of assumptions has been made about the growth rate of the installed wind power capacity in Northern India and about the number of wind turbine manufacturing companies in the target area of the centre. From these assumptions the total number of new wind turbine types coming on the Indian market annually is derived for a period of ten years. These figures have served as a basis for the determination of the required manpower and facilities of the centre for design and development support activities, feasibility and siting studies, testing and certification. Furthermore a projection has been made for providing expert manpower capacity for carrying out R and D, consultancy and other services. 14 tabs., 1 ref

  9. A strategy for fast screening and identification of sulfur derivatives in medicinal Pueraria species based on the fine isotopic pattern filtering method using ultra-high-resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Min [National Engineering Laboratory for TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Shanghai 201203 (China); Zhou, Zhe [ThermoFisher Scientific China Co., Ltd, No 6 Building, 27 Xinjinqiao Road, Shanghai 201206 (China); Guo, De-an, E-mail: daguo@simm.ac.cn [National Engineering Laboratory for TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Shanghai 201203 (China)

    2015-09-24

    Sulfurous compounds are commonly present in plants, fungi, and animals. Most of them were reported to possess various bioactivities. Isotopic pattern filter (IPF) is a powerful tool for screening compounds with distinct isotope pattern. Over the past decades, the IPF was used mainly to study Cl- and Br-containing compounds. To our knowledge, the algorithm was scarcely used to screen S-containing compounds, especially when combined with chromatography analyses, because the {sup 34}S isotopic ion is drastically affected by {sup 13}C{sub 2} and {sup 18}O. Thus, we present a new method for a fine isotopic pattern filter (FIPF) based on the separated M + 2 ions ({sup 12}C{sub x}{sup 1}H{sub y}{sup 16}O{sub z}{sup 32}S{sup 13}C{sub 2}{sup 18}O, {sup 12}C{sub x+2}{sup 1}H{sub y}{sup 16}O{sub z+1}{sup 34}S, tentatively named M + 2OC and M + 2S) with an ultra-high-resolution mass (100,000 FWHM @ 400 m/z) to screen sulfur derivatives in traditional Chinese medicines (TCM).This finer algorithm operates through convenient filters, including an accurate mass shift of M + 2OC and M + 2S from M and their relative intensity compared to M. The method was validated at various mass resolutions, mass accuracies, and screening thresholds of flexible elemental compositions. Using the established FIPF method, twelve S-derivatives were found in the popular medicinal used Pueraria species, and 9 of them were tentatively identified by high-resolution multiple stage mass spectrometry (HRMS{sup n}). The compounds were used to evaluate the sulfurous compounds' situation in commercially purchased Pueraria products. The strategy presented here provides a promising application of the IPF method in a new field. - Highlights: • We provide a new strategy for specifically screening of sulfurous compounds. • The fine isotopic pattern filter (FIPF) bases on separation of {sup 13}C{sub 2}+{sup 18}O and {sup 34}S. • Ultra high resolution mass (100,000 FWHM @ 400 m/z) is essential

  10. State of the Art and Trends in Wind Resource Assessment

    Directory of Open Access Journals (Sweden)

    Oliver Probst

    2010-06-01

    Full Text Available Given the significant rise of the utilization of wind energy the accurate assessment of the wind potential is becoming increasingly important. Direct applications of wind assessment techniques include the creation of wind maps on a local scale (typically 5 20 km and the micrositing of wind turbines, the estimation of vertical wind speed variations, prospecting on a regional scale (>100 km, estimation of the long-term wind resource at a given site, and forecasting. The measurement of wind speed and direction still widely relies on cup anemometers, though sonic anemometers are becoming increasingly popular. Moreover, remote sensing by Doppler techniques using the backscattering of either sonic beams (SODAR or light (LIDAR allowing for vertical profiling well beyond hub height are quickly moving into the mainstream. Local wind maps are based on the predicted modification of the regional wind flow pattern by the local atmospheric boundary layer which in turn depends on both topographic and roughness features and the measured wind rose obtained from one or several measurement towers within the boundaries of the planned development site. Initial models were based on linearized versions of the Navier-Stokes equations, whereas more recently full CFD models have been applied to wind farm micrositing. Linear models tend to perform well for terrain slopes lower than about 25% and have the advantage of short execution times. Long-term performance is frequently estimated from correlations with nearby reference stations with concurrent information and continuous time series over a period of at least 10 years. Simple methods consider only point-to-point linear correlations; more advanced methods like multiple regression techniques and methods based on the theory of distributions will be discussed. Both for early prospecting in regions where only scarce or unreliable reference information is available, wind flow modeling on a larger scale (mesoscale is becoming

  11. European Wind Atlas and Wind Resource Research in Denmark

    DEFF Research Database (Denmark)

    Mortensen, Niels Gylling

    to estimate the actual wind climate at any specific site and height within this region. The Danish and European Wind Atlases are examples of how the wind atlas methodology can be employed to estimate the wind resource potential for a country or a sub-continent. Recently, the methodology has also been used...... - from wind measurements at prospective sites to wind tunnel simulations and advanced flow modelling. Among these approaches, the wind atlas methodology - developed at Ris0 National Laboratory over the last 25 years - has gained widespread recognition and is presently considered by many as the industry......-standard tool for wind resource assessment and siting of wind turbines. The PC-implementation of the methodology, the Wind Atlas Analysis and Application Program (WAsP), has been applied in more than 70 countries and territories world-wide. The wind atlas methodology is based on physical descriptions and models...

  12. Observation Targeting for the Tehachapi Pass and Mid-Columbia Basin: WindSENSE Phase III Project Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Hanley, D

    2011-10-22

    applied and evaluated for the wind plants in the Tehachapi Pass region for a period during the warm season. That research demonstrated that forecast sensitivity derived from the dataset was characterized by well-defined, localized patterns for a number of state variables such as the 80-m wind and the 25-m to 1-km temperature difference prior to the forecast time. The sensitivity patterns produced as part of the Tehachapi Pass study were coherent and consistent with the basic physical processes that drive wind patterns in the Tehachapi area. In Phase II of the WindSENSE project, the ESA-MOOA approach was extended and applied to the wind plants located in the Mid-Columbia Basin wind generation area of Washington-Oregon during the summer and to the Tehachapi Pass region during the winter. The objective of this study was to identify measurement locations and variables that have the greatest positive impact on the accuracy of wind forecasts in the 0- to 6-hour look-ahead periods for the two regions and to establish a higher level of confidence in ESA-MOOA for mesoscale applications. The detailed methodology and results are provided in separate technical reports listed in the publications section below. Ideally, the data assimilation scheme used in the Phase III experiments would have been based upon an ensemble Kalman filter (EnKF) that was similar to the ESA method used to diagnose the Mid-Columbia Basin sensitivity patterns in the previous studies. However, running an EnKF system at high resolution is impractical because of the very high computational cost. Thus, it was decided to use a three-dimensional variational (3DVAR) analysis scheme that is less computationally intensive. The objective of this task is to develop an observation system deployment strategy for the mid Columbia Basin (i.e. the BPA wind generation region) that is designed to produce the maximum benefit for 1- to 6-hour ahead forecasts of hub-height ({approx}80 m) wind speed with a focus on periods of large

  13. Neural Network Classifiers for Local Wind Prediction.

    Science.gov (United States)

    Kretzschmar, Ralf; Eckert, Pierre; Cattani, Daniel; Eggimann, Fritz

    2004-05-01

    This paper evaluates the quality of neural network classifiers for wind speed and wind gust prediction with prediction lead times between +1 and +24 h. The predictions were realized based on local time series and model data. The selection of appropriate input features was initiated by time series analysis and completed by empirical comparison of neural network classifiers trained on several choices of input features. The selected input features involved day time, yearday, features from a single wind observation device at the site of interest, and features derived from model data. The quality of the resulting classifiers was benchmarked against persistence for two different sites in Switzerland. The neural network classifiers exhibited superior quality when compared with persistence judged on a specific performance measure, hit and false-alarm rates.

  14. Reliability of Wind Speed Data from Satellite Altimeter to Support Wind Turbine Energy

    Science.gov (United States)

    Uti, M. N.; Din, A. H. M.; Omar, A. H.

    2017-10-01

    Satellite altimeter has proven itself to be one of the important tool to provide good quality information in oceanographic study. Nowadays, most countries in the world have begun in implementation the wind energy as one of their renewable energy for electric power generation. Many wind speed studies conducted in Malaysia using conventional method and scientific technique such as anemometer and volunteer observing ships (VOS) in order to obtain the wind speed data to support the development of renewable energy. However, there are some limitations regarding to this conventional method such as less coverage for both spatial and temporal and less continuity in data sharing by VOS members. Thus, the aim of this research is to determine the reliability of wind speed data by using multi-mission satellite altimeter to support wind energy potential in Malaysia seas. Therefore, the wind speed data are derived from nine types of satellite altimeter starting from year 1993 until 2016. Then, to validate the reliability of wind speed data from satellite altimeter, a comparison of wind speed data form ground-truth buoy that located at Sabah and Sarawak is conducted. The validation is carried out in terms of the correlation, the root mean square error (RMSE) calculation and satellite track analysis. As a result, both techniques showing a good correlation with value positive 0.7976 and 0.6148 for point located at Sabah and Sarawak Sea, respectively. It can be concluded that a step towards the reliability of wind speed data by using multi-mission satellite altimeter can be achieved to support renewable energy.

  15. Community patterns of tropical tree phenology derived from Unmanned Aerial Vehicle images: intra- and interspecific variation, association with species plant traits, and response to interannual climate variation

    Science.gov (United States)

    Bohlman, Stephanie; Rifai, Sami; Park, John; Dandois, Jonathan; Muller-Landau, Helene

    2017-04-01

    Phenology is a key life history trait of plant species and critical driver of ecosystem processes. There is strong evidence that phenology is shifting in temperate ecosystems in response to climate change, but tropical forest phenology remains poorly quantified and understood. A key challenge is that tropical forests contain hundreds of plant species with a wide variety of phenological patterns, which makes it difficult to collect sufficient ground-based field data to characterize individual tropical tree species phenologies. Satellite-based observations, an important source of phenology data in northern latitudes, are hindered by frequent cloud cover in the tropics. To quantify phenology over a large number of individuals and species, we collected bi-weekly images from unmanned aerial vehicles (UAVs) in the well-studied 50-ha forest inventory plot on Barro Colorado Island, Panama. The objective of this study is to quantify inter- and intra-specific responses of tropical tree leaf phenology to environmental variation over large spatial scales and identify key environmental variables and physiological mechanisms underpinning phenological variation. Between October 2014 and December 2015 and again in May 2015, we collected a total of 35 sets of UAV images, each with continuous coverage of the 50-ha plot, where every tree ≥ 1 cm DBH is mapped. UAV imagery was corrected for exposure, orthorectified, and then processed to extract spectral, texture, and image information for individual tree crowns, which was then used as inputs for a machine learning algorithm that successfully predicted the percentages of leaf, branch, and flower cover for each tree crown (r2=0.76 between observed and predicted percent branch cover for individual tree crowns). We then quantified cumulative annual deciduousness for each crown by fitting a non-parametric curve of flexible shape to its predicted percent branch time series and calculated the area under the curve. We obtained the species

  16. Extreme winds in the Western North Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Ott, S.

    2006-11-15

    A statistical model for extreme winds in the western North Pacific is developed, the region on the Planet where tropical cyclones are most common. The model is based on best track data derived mostly from satellite images of tropical cyclones. The methods used to estimate surface wind speeds from satellite images is discussed with emphasis on the empirical basis, which, unfortunately, is not very strong. This is stressed by the fact that Japanese and US agencies arrive at markedly different estimates. On the other hand, best track data records cover a long period of time and if not perfect they are at least coherent over time in their imperfections. Applying the the Holland model to the best track data, wind profiles can be assigned along the tracks. From this annual wind speed maxima at any particular point in the region can be derived. The annual maxima, in turn, are fitted to a Gumbel distribution using a generalization Abild's method that allows for data wind collected from multiple positions. The choice of this method is justified by a Monte Carlo simulation comparing it to two other methods. The principle output is a map showing fifty year winds in the region. The method is tested against observed winds from Philippine synoptic stations and fair agreement is found for observed and predicted 48 year maxima. However, the almost biasfree performance of the model could be fortuitous, since precise definitions of 'windspeed' in terms averaging time, height above ground and assumed surface roughness are not available, neither for best tracks nor for the synoptic data. The work has been carried out under Danish Research Agency grant 2104-04-0005 'Offshore wind power' and it also covers the findings and analysis carried out in connection with task 1.6 of the project 'Feasibility Assessment and Capacity Building for Wind Energy Development in Cambodia, The Philippines and Vietnam' during 2005-06 under contract 125-2004 with EU

  17. Wind and tornado guidelines

    International Nuclear Information System (INIS)

    McDonald, J.R.

    1989-01-01

    The objective of the Department of Energy Natural Phenomena Hazards Project is to provide guidance and criteria for design of new facilities and for evaluation of existing ones subjected to extreme winds, earthquakes, and floods. This paper describes the treatment of wind and tornado hazards. Four facility-use categories are defined which represent increasing levels of risk to personnel or the environment in the event of a high wind event. Facilities are assigned to a particular category, depending on their mission, value, or toxic material content. The assigned facility-use category determines the design and evaluation criteria. The criteria are based on probabilistic hazard assessment. Performance goals are also specified for each facility-use category. A uniform approach to design wind loads, based on the ANSI A58.1-1982 standard, allows treatment of high winds and hurricane and tornado winds in a similar manner. Based on the wind hazard models, some sites must account for the possibility of tornadoes while others do not. Atmospheric pressure changes and missiles must be taken into account when considering tornadoes. The design and evaluation guidelines are designed to establish consistent levels of risk for different natural phenomena hazards and for facilities at different geographical locations

  18. Wind energy in Europe

    International Nuclear Information System (INIS)

    Sesto, E.

    1992-02-01

    Interest in wind energy as a supplementary source for the production of electricity has recently gained renewed momentum due to widespread concern about environmental impacts from the large scale use of fossil fuels and nuclear energy. In addition, political unrest in the Middle East has drawn attention to the importance of national energy self-sufficiency. European government administrations, however, have not yet fully appreciated the real worth of the 'clean energy' afforded by wind energy. In this regard, the European Wind Energy Association (EWEA) is acting as a strong voice to inform the public and energy planners by stimulating international wind energy R ampersand D cooperation, and organizing conferences to explain the advantages of wind energy. In October 1991, EWEA published a strategy document giving a picture of the real possibilities offered by wind energy within the geographical, social, and European economic context. This paper provides an overview of the more significant features to emerge from this document which represents a useful guideline for wind power plant technical/economic feasibility studies in that it contains brief notes on resource availability, land requirements, visual and acoustic impacts, turbine sizing, performance, interconnection to utility grids, maintenance and operating costs, safety, as well as, on marketing aspects

  19. Wind farms and planning

    International Nuclear Information System (INIS)

    Arkesteijn, L.; Havinga, R.; Benner, J.H.B.

    1992-01-01

    The siting of wind farms is becoming an increasingly important issue in the Netherlands. This paper gives an overview of the current situation concerning the planning of wind farms. We will pay attention to: Wind energy in official Dutch planning policy. To select the optimal sites, the government has made an administrative agreement with the 7 windy provinces. Nevertheless, wind energy is still fighting for a rightful position in physical planning policy. Some examples will illustrate this. Studies on siting and siting problems in the Netherlands. In order to gain more insight into aspects of wind farming several studies have been executed. In this paper special attention will be paid to the results of a study on the potential impact of large windturbine clusters on an existing agricutural area. Experiences with siting of wind farms in the Netherlands. Based on experiences with the planning and realization of farms, this paper gives the main problems. In the final part of the paper we present some general conclusions. Generally speaking, the knowledge is available for selecting optimal sites in the Netherlands. The basic problems for wind farming nowadays seem to be the visual impact and actually obtaining the ground. Nevertheless, there do seem to be enough sites for realizing the goals in the Netherlands. (au)

  20. Database on wind characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, K.S. [The Technical Univ. of Denmark (Denmark); Courtney, M.S. [Risoe National Lab., (Denmark)

    1999-08-01

    The organisations that participated in the project consists of five research organisations: MIUU (Sweden), ECN (The Netherlands), CRES (Greece), DTU (Denmark), Risoe (Denmark) and one wind turbine manufacturer: Vestas Wind System A/S (Denmark). The overall goal was to build a database consisting of a large number of wind speed time series and create tools for efficiently searching through the data to select interesting data. The project resulted in a database located at DTU, Denmark with online access through the Internet. The database contains more than 50.000 hours of measured wind speed measurements. A wide range of wind climates and terrain types are represented with significant amounts of time series. Data have been chosen selectively with a deliberate over-representation of high wind and complex terrain cases. This makes the database ideal for wind turbine design needs but completely unsuitable for resource studies. Diversity has also been an important aim and this is realised with data from a large range of terrain types; everything from offshore to mountain, from Norway to Greece. (EHS)