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Sample records for wave height

  1. Encounter Probability of Significant Wave Height

    DEFF Research Database (Denmark)

    Liu, Z.; Burcharth, H. F.

    The determination of the design wave height (often given as the significant wave height) is usually based on statistical analysis of long-term extreme wave height measurement or hindcast. The result of such extreme wave height analysis is often given as the design wave height corresponding to a c...

  2. On the Extreme Wave Height Analysis

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Zhou

    1994-01-01

    The determination of the design wave height is usually based on the statistical analysis of long-term extreme wave height measurements. After an introduction to the procedure of the extreme wave height analysis, the paper presents new development concerning various aspects of the extreme wave...... height analysis. Finally, the paper gives a practical example based on a data set of the hindcasted wave heights for a deep water location in the Mediterranean Sea....

  3. Encounter Probability of Individual Wave Height

    DEFF Research Database (Denmark)

    Liu, Z.; Burcharth, H. F.

    1998-01-01

    wave height corresponding to a certain exceedence probability within a structure lifetime (encounter probability), based on the statistical analysis of long-term extreme significant wave height. Then the design individual wave height is calculated as the expected maximum individual wave height...... associated with the design significant wave height, with the assumption that the individual wave heights follow the Rayleigh distribution. However, the exceedence probability of such a design individual wave height within the structure lifetime is unknown. The paper presents a method for the determination...... of the design individual wave height corresponding to an exceedence probability within the structure lifetime, given the long-term extreme significant wave height. The method can also be applied for estimation of the number of relatively large waves for fatigue analysis of constructions....

  4. Challenges in Defining Tsunami Wave Height

    Science.gov (United States)

    Stroker, K. J.; Dunbar, P. K.; Mungov, G.; Sweeney, A.; Arcos, N. P.

    2017-12-01

    The NOAA National Centers for Environmental Information (NCEI) and co-located World Data Service for Geophysics maintain the global tsunami archive consisting of the historical tsunami database, imagery, and raw and processed water level data. The historical tsunami database incorporates, where available, maximum wave heights for each coastal tide gauge and deep-ocean buoy that recorded a tsunami signal. These data are important because they are used for tsunami hazard assessment, model calibration, validation, and forecast and warning. There have been ongoing discussions in the tsunami community about the correct way to measure and report these wave heights. It is important to understand how these measurements might vary depending on how the data were processed and the definition of maximum wave height. On September 16, 2015, an 8.3 Mw earthquake located 48 km west of Illapel, Chile generated a tsunami that was observed all over the Pacific region. We processed the time-series water level data for 57 tide gauges that recorded this tsunami and compared the maximum wave heights determined from different definitions. We also compared the maximum wave heights from the NCEI-processed data with the heights reported by the NOAA Tsunami Warning Centers. We found that in the near field different methods of determining the maximum tsunami wave heights could result in large differences due to possible instrumental clipping. We also found that the maximum peak is usually larger than the maximum amplitude (½ peak-to-trough), but the differences for the majority of the stations were Warning Centers. Since there is currently only one field in the NCEI historical tsunami database to store the maximum tsunami wave height, NCEI will consider adding an additional field for the maximum peak measurement.

  5. Wave Height Distribution Observed by Ships in the North Atlantic

    DEFF Research Database (Denmark)

    Olsen, Anders Smærup; Schrøter, Carsten; Jensen, Jørgen Juncher

    2005-01-01

    for the significant wave height, the relative speed and the ship heading relative to the wave direction is given. This distribution shows that for higher waves the crews avoid sailing in following sea and as expected the speed is decreased in higher waves. There is, however, still a relatively high probability...

  6. Synthesizing Waves from Animated Height Fields

    DEFF Research Database (Denmark)

    Nielsen, Michael Bang; Söderström, Andreas; Bridson, Robert

    2013-01-01

    Computer animated ocean waves for feature films are typically carefully choreographed to match the vision of the director and to support the telling of the story. The rough shape of these waves is established in the previsualization (previs) stage, where artists use a variety of modeling tools wi...... of deep water waves), and compute a physically reasonable velocity field of the water analytically. These properties are demonstrated with several examples, including a previs scene from a visual effects production environment....

  7. Multiresolution wavelet-ANN model for significant wave height forecasting.

    Digital Repository Service at National Institute of Oceanography (India)

    Deka, P.C.; Mandal, S.; Prahlada, R.

    Hybrid wavelet artificial neural network (WLNN) has been applied in the present study to forecast significant wave heights (Hs). Here Discrete Wavelet Transformation is used to preprocess the time series data (Hs) prior to Artificial Neural Network...

  8. Statistical analysis on extreme wave height

    Digital Repository Service at National Institute of Oceanography (India)

    Teena, N.V.; SanilKumar, V.; Sudheesh, K.; Sajeev, R.

    -294. • WAFO (2000) – A MATLAB toolbox for analysis of random waves and loads, Lund University, Sweden, homepage http://www.maths.lth.se/matstat/wafo/,2000. 15    Table 1: Statistical results of data and fitted distribution for cumulative distribution...

  9. Significant wave height retrieval from synthetic radar images

    NARCIS (Netherlands)

    Wijaya, Andreas Parama; van Groesen, Embrecht W.C.

    2014-01-01

    In many offshore activities radar imagery is used to observe and predict ocean waves. An important issue in analyzing the radar images is to resolve the significant wave height. Different from 3DFFT methods that use an estimate related to the square root of the signal-to-noise ratio of radar images,

  10. A generalized multivariate regression model for modelling ocean wave heights

    Science.gov (United States)

    Wang, X. L.; Feng, Y.; Swail, V. R.

    2012-04-01

    In this study, a generalized multivariate linear regression model is developed to represent the relationship between 6-hourly ocean significant wave heights (Hs) and the corresponding 6-hourly mean sea level pressure (MSLP) fields. The model is calibrated using the ERA-Interim reanalysis of Hs and MSLP fields for 1981-2000, and is validated using the ERA-Interim reanalysis for 2001-2010 and ERA40 reanalysis of Hs and MSLP for 1958-2001. The performance of the fitted model is evaluated in terms of Pierce skill score, frequency bias index, and correlation skill score. Being not normally distributed, wave heights are subjected to a data adaptive Box-Cox transformation before being used in the model fitting. Also, since 6-hourly data are being modelled, lag-1 autocorrelation must be and is accounted for. The models with and without Box-Cox transformation, and with and without accounting for autocorrelation, are inter-compared in terms of their prediction skills. The fitted MSLP-Hs relationship is then used to reconstruct historical wave height climate from the 6-hourly MSLP fields taken from the Twentieth Century Reanalysis (20CR, Compo et al. 2011), and to project possible future wave height climates using CMIP5 model simulations of MSLP fields. The reconstructed and projected wave heights, both seasonal means and maxima, are subject to a trend analysis that allows for non-linear (polynomial) trends.

  11. Measuring sea surface height with a GNSS-Wave Glider

    Science.gov (United States)

    Morales Maqueda, Miguel Angel; Penna, Nigel T.; Foden, Peter R.; Martin, Ian; Cipollini, Paolo; Williams, Simon D.; Pugh, Jeff P.

    2017-04-01

    A GNSS-Wave Glider is a novel technique to measure sea surface height autonomously using the Global Navigation Satellite System (GNSS). It consists of an unmanned surface vehicle manufactured by Liquid Robotics, a Wave Glider, and a geodetic-grade GNSS antenna-receiver system, with the antenna installed on a mast on the vehicle's deck. The Wave Glider uses the differential wave motion through the water column for propulsion, thus guaranteeing an, in principle, indefinite autonomy. Solar energy is collected to power all on-board instrumentation, including the GNSS system. The GNSS-Wave Glider was first tested in Loch Ness in 2013, demonstrating that the technology is capable of mapping geoid heights within the loch with an accuracy of a few centimetres. The trial in Loch Ness did not conclusively confirm the reliability of the technique because, during the tests, the state of the water surface was much more benign than would normally be expect in the open ocean. We now report on a first deployment of a GNSS-Wave Glider in the North Sea. The deployment took place in August 2016 and lasted thirteen days, during which the vehicle covered a distance of about 350 nautical miles in the north western North Sea off Great Britain. During the experiment, the GNSS-Wave Glider experienced sea states between 1 (0-0.1 m wave heights) and 5 (2.5-4 m wave heights). The GNSS-Wave Glider data, recorded at 5 Hz frequency, were analysed using a post-processed kinematic GPS-GLONASS precise point positioning (PPP) approach, which were quality controlled using double difference GPS kinematic processing with respect to onshore reference stations. Filtered with a 900 s moving-average window, the PPP heights reveal geoid patterns in the survey area that are very similar to the EGM2008 geoid model, thus demonstrating the potential use of a GNSS-Wave Glider for marine geoid determination. The residual of subtracting the modelled or measured marine geoid from the PPP signal combines information

  12. Empirical Guidelines for Use of Irregular Wave Model to Estimate Nearshore Wave Height.

    Science.gov (United States)

    1982-07-01

    height, the easier to use tech- nique presented by McClenan (1975) was employed. The McClenan technique uti- lizes a monogram which was constructed from...the SPM equations and gives the same results. The inputs to the monogram technique are the period, the deep- water wave height, the deepwater wave

  13. Encountered Wave Height Distributions for Ships in the North Atlantic

    DEFF Research Database (Denmark)

    Olsen, Anders Smærup; Schrøter, C.; Jensen, Jørgen Juncher

    2004-01-01

    About 20 000 observations of wave heights taken on board vessels sailing in the North Atlantic are presented. The data covers year 2002 and 2003 and stem from a variety of ship types. From the preliminary analysis of the data some conclusions are reached about the effect of weather routing whether...

  14. Distributions of freak wave heights measured in the North Sea

    International Nuclear Information System (INIS)

    Stansell, P.

    2004-01-01

    We present a statistical analysis of some of the largest waves occurring during 793 h of surface elevation measurements collected during 14 severe storms in the North Sea. This data contains 104 freak waves. It is found that the probability of occurrence of freak waves is only weekly dependent on the significant wave height, significant wave steepness and spectral bandwidth. The probability does show a slightly stronger dependency on the skew and kurtosis of the surface elevation data, but on removing the contribution to these measures from the presence of the freakwaves themselves, this dependency largely disappears. Distributions of extreme waves are modelled by fitting Generalised Pareto distributions, and extreme value distributions and return periods are given for freak waves in terms of the empirical fitted parameters. It is shown by comparison with these fits that both the Rayleigh distribution and the fit of Nerzic and Prevosto severely under-predict the probability of occurrence of extreme waves. For the most extreme freak wave in our data, the Rayleigh distribution over-predicts the return period by about 300 times when compared to the fitted model. (author)

  15. Investigation of Wave Height Reduction behind the Wave Dragon Wave Energy Converters and Application in Santander, Spain

    DEFF Research Database (Denmark)

    Nørgaard, Jørgen Quvang Harck; Andersen, Thomas Lykke

    This paper deals with a case study on the wave height reduction behind floating Wave Dragon wave energy converters in Santander Bay, Spain. The study is performed using the MIKE21 Boussinesq model from DHI. The Wave Dragon transmission characteristics in the numerical wave propagation model...... are based on previously performed physical model tests in scale 1:51. Typical winter storm conditions are considered in the case study together with different stiffness in the mooring system of the floating device. From the study it is found that if multiple Wave Dragons are positioned in a farm the wave...

  16. Estimation of design wave heights based on exterme value statistics for Kakinada coast, Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; Nayak, B.U.; Raju, N.S.N.

    Statistical analyses for longterm distribution of significant wave heights were performed using Lognormal, Weibull, Gumbel and Fretcher distributions for waves measured off Kakinada, Andhra Pradesh, India from June 1983 to May 1984. Fretcher...

  17. A Rational Procedure for Determination of Directional Individual Design Wave Heights

    DEFF Research Database (Denmark)

    Sterndorff, M.; Sørensen, John Dalsgaard

    2001-01-01

    For code-based LRFD and for reliability-based assessment of offshore structures such as steel platforms it is essential that consistent directional and omnidirectional probability distributions for the maximum significant wave height, the maximum individual wave height, and the maximum individual...

  18. Gridded 5-day mean sea surface height anomaly and significant wave height from Jason-1 and OSTM/Jason-2 satellites (NODC Accession 0065055)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This accession contains the gridded 5-day mean sea surface height anomaly (SSHA) and Ku Band significant wave height (SWH-KU) observed from Jason-1 and OSTM/Jason-2...

  19. Seasonal distribution of wave heights off Yanam on the east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Nayak, B.U.; Chandramohan, D.; Sakhardande, R.N.

    , maximum wave height and zero crossing wave period are presented and discussed. Inter-comparison of wave parameters computEd. by the three different methods was also done and linear relationships were obtainEd. by the method of least square...

  20. Small-scale open ocean currents have large effects on wind wave heights

    Science.gov (United States)

    Ardhuin, Fabrice; Gille, Sarah T.; Menemenlis, Dimitris; Rocha, Cesar B.; Rascle, Nicolas; Chapron, Bertrand; Gula, Jonathan; Molemaker, Jeroen

    2017-06-01

    Tidal currents and large-scale oceanic currents are known to modify ocean wave properties, causing extreme sea states that are a hazard to navigation. Recent advances in the understanding and modeling capability of open ocean currents have revealed the ubiquitous presence of eddies, fronts, and filaments at scales 10-100 km. Based on realistic numerical models, we show that these structures can be the main source of variability in significant wave heights at scales less than 200 km, including important variations down to 10 km. Model results are consistent with wave height variations along satellite altimeter tracks, resolved at scales larger than 50 km. The spectrum of significant wave heights is found to be of the order of 70>>2/>(g2>>2>) times the current spectrum, where >> is the spatially averaged significant wave height, >> is the energy-averaged period, and g is the gravity acceleration. This variability induced by currents has been largely overlooked in spite of its relevance for extreme wave heights and remote sensing.Plain Language SummaryWe show that the variations in currents at scales 10 to 100 km are the main source of variations in wave heights at the same scales. Our work uses a combination of realistic numerical models for currents and waves and data from the Jason-3 and SARAL/AltiKa satellites. This finding will be of interest for the investigation of extreme wave heights, remote sensing, and air-sea interactions. As an immediate application, the present results will help constrain the error budget of the up-coming satellite missions, in particular the Surface Water and Ocean Topography (SWOT) mission, and decide how the data will have to be processed to arrive at accurate sea level and wave measurements. It will also help in the analysis of wave measurements by the CFOSAT satellite.

  1. Estimation of sea surface wave height from Bhaskara II SAMIR data

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, M.V.; Viswambharan, N.K.; Rao, L.V.G.

    from R V Gaveshani and visual observations from other ships as reported in IDWR) are available. Using this, an attempt has been made to obtain an empirical relation between brightness temperature and significant wave height. Linear correlation between...

  2. On microseisms recorded near the Ligurian coast (Italy) and their relationship with sea wave height

    DEFF Research Database (Denmark)

    Ferretti, G.; Zunino, Andrea; Scafidi, D.

    2013-01-01

    data set including also observations from January to December 2011 is used to calibrate an empirical predictive relation for sea wave height whose functional form is a modified version of the classical definition of H13 . By means of a Markov chainMonte Carlo algorithm we set up a procedure...... to investigate the inverse problem and to find a set of parameter values for predicting sea wave heights from microseism....

  3. Earthquake Scenario-Based Tsunami Wave Heights in the Eastern Mediterranean and Connected Seas

    Science.gov (United States)

    Necmioglu, Ocal; Özel, Nurcan Meral

    2015-12-01

    We identified a set of tsunami scenario input parameters in a 0.5° × 0.5° uniformly gridded area in the Eastern Mediterranean, Aegean (both for shallow- and intermediate-depth earthquakes) and Black Seas (only shallow earthquakes) and calculated tsunami scenarios using the SWAN-Joint Research Centre (SWAN-JRC) code ( Mader 2004; Annunziato 2007) with 2-arcmin resolution bathymetry data for the range of 6.5—Mwmax with an Mw increment of 0.1 at each grid in order to realize a comprehensive analysis of tsunami wave heights from earthquakes originating in the region. We defined characteristic earthquake source parameters from a compiled set of sources such as existing moment tensor catalogues and various reference studies, together with the Mwmax assigned in the literature, where possible. Results from 2,415 scenarios show that in the Eastern Mediterranean and its connected seas (Aegean and Black Sea), shallow earthquakes with Mw ≥ 6.5 may result in coastal wave heights of 0.5 m, whereas the same wave height would be expected only from intermediate-depth earthquakes with Mw ≥ 7.0 . The distribution of maximum wave heights calculated indicate that tsunami wave heights up to 1 m could be expected in the northern Aegean, whereas in the Black Sea, Cyprus, Levantine coasts, northern Libya, eastern Sicily, southern Italy, and western Greece, up to 3-m wave height could be possible. Crete, the southern Aegean, and the area between northeast Libya and Alexandria (Egypt) is prone to maximum tsunami wave heights of >3 m. Considering that calculations are performed at a minimum bathymetry depth of 20 m, these wave heights may, according to Green's Law, be amplified by a factor of 2 at the coastline. The study can provide a basis for detailed tsunami hazard studies in the region.

  4. The maximum significant wave height in the Southern North Sea

    NARCIS (Netherlands)

    Bouws, E.; Tolman, H.L.; Holthuijsen, L.H.; Eldeberky, Y.; Booij, N.; Ferier, P.

    1995-01-01

    The maximum possible wave conditions along the Dutch coast, which seem to be dominated by the limited water depth, have been estimated in the present study with numerical simulations. Discussions with meteorologists suggest that the maximum possible sustained wind speed in North Sea conditions is

  5. Corrections for the effects of significant wave height and attitude on Geosat radar altimeter measurements

    Science.gov (United States)

    Hayne, G. S.; Hancock, D. W., III

    1990-01-01

    Range estimates from a radar altimeter have biases which are a function of the significant wave height (SWH) and the satellite attitude angle (AA). Based on results of prelaunch Geosat modeling and simulation, a correction for SWH and AA was already applied to the sea-surface height estimates from Geosat's production data processing. By fitting a detailed model radar return waveform to Geosat waveform sampler data, it is possible to provide independent estimates of the height bias, the SWH, and the AA. The waveform fitting has been carried out for 10-sec averages of Geosat waveform sampler data over a wide range of SWH and AA values. The results confirm that Geosat sea-surface-height correction is good to well within the original dm-level specification, but that an additional height correction can be made at the level of several cm.

  6. Auto-correlation analysis of wave heights in the Bay of Bengal

    Indian Academy of Sciences (India)

    Time series observations of significant wave heights in the Bay of Bengal were subjected to auto- correlation analysis to determine temporal variability scale. The analysis indicates an exponen- tial fall of auto-correlation in the first few hours with a decorrelation time scale of about six hours. A similar figure was found earlier ...

  7. Variations mechanism in entropy of wave height field and its relation with thermodynamic entropy

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper gives a brief description of annual period and seasonal variation in the wave height field entropy in the northeastern Pacific. A calculation of the quantity of the, received by lithosphere systems in the northern hemisphere is introduced. The wave heat field entropy is compared with the difference in the quantity of the sun's radiation heat. Analysis on the transfer method, period and lag of this seasonal variation led to the conclusion that the annual period and seasonal variation in the entropy of the wave height field in the Northwestern Pacific is due to the seasonal variation of the sun's radiation heat. Furthermore, the inconsistency between thermodynamic entropy and information entropy was studied.

  8. Comprehensive Prediction of Large-height Swell-like Waves in East Coast of Korea

    Science.gov (United States)

    Kwon, S. J.; Lee, C.; Ahn, S. J.; Kim, H. K.

    2014-12-01

    There have been growing interests in the large-height swell-like wave (LSW) in the east coast of Korea because such big waves have caused human victims as well as damages to facilities such as breakwaters in the coast. The LSW was found to be generated due to an atmospherically great valley in the north area of the East Sea and then propagate long distance to the east coast of Korea in prominently southwest direction (Oh et al., 2010).In this study, we will perform two methods, real-time data based and numerical-model based predictions in order to predict the LSW in the east coast of Korea. First, the real-time data based prediction method uses information which is collected by the directional wave gauge installed near Sokcho. Using the wave model SWAN (Booij et al., 1999) and the wave ray method (Munk and Arthur, 1952), we will estimate wave data in open sea from the real-time data and predict the travel time of LSW from the measurement site (near Sokcho) to several target points in the east coast of Korea. Second, the numerical-model based method uses three different numerical models; WW3 in deep water, SWAN in shallow water, and CADMAS-SURF for wave run-up (CDIT). The surface winds from the 72 hours prediction system of NCEP (National Centers for Environmental Prediction) GFS (Global Forecast System) will be inputted in finer grids after interpolating these in certain domains of WW3 and SWAN models. The significant wave heights and peak wave directions predicted by the two methods will be compared to the measured data of LSW at several target points near the coasts. Further, the prediction method will be improved using more measurement sites which will be installed in the future. ReferencesBooij, N., Ris, R.C., and Holthuijsen, L.H. (1999). A third-generation wave model for coastal regions 1. Model description and validation. J. of Geophysical Research, 103(C4), 7649-7666.Munk, W.H. and Arthur, R.S. (1952). Gravity Waves. 13. Wave Intensity along a Refracted Ray

  9. Azimuth cut-off model for significant wave height investigation along coastal water of Kuala Terengganu, Malaysia

    Science.gov (United States)

    Marghany, Maged; Ibrahim, Zelina; Van Genderen, Johan

    2002-11-01

    The present work is used to operationalize the azimuth cut-off concept in the study of significant wave height. Three ERS-1 images have been used along the coastal waters of Terengganu, Malaysia. The quasi-linear transform was applied to map the SAR wave spectra into real ocean wave spectra. The azimuth cut-off was then used to model the significant wave height. The results show that azimuth cut-off varied with the different period of the ERS-1 images. This is because of the fact that the azimuth cut-off is a function of wind speed and significant wave height. It is of interest to find that the significant wave height modeled from azimuth cut-off is in good relation with ground wave conditions. It can be concluded that ERS-1 can be used as a monitoring tool in detecting the significant wave height variation. The azimuth cut-off can be used to model the significant wave height. This means that the quasi-linear transform could be a good application to significant wave height variation during different seasons.

  10. Progress Report on the GROWTH (GNSS Reflectometry for Ocean Waves, Tides, and Height) Research Project

    Science.gov (United States)

    Kitazawa, Y.; Ichikawa, K.; Akiyama, H.; Ebinuma, T.; Isoguchi, O.; Kimura, N.; Konda, M.; Kouguchi, N.; Tamura, H.; Tomita, H.; Yoshikawa, Y.; Waseda, T.

    2016-12-01

    Global Navigation Satellite Systems (GNSS), such as GPS is a system of satellites that provide autonomous geo-spatial positioning with global coverage. It allows small electronic receivers to determine their location to high precision using radio signals transmitted from satellites, GNSS reflectometry (GNSS-R) involves making measurements from the reflections from the Earth of navigation signals from GNSS satellites. Reflected signals from sea surface are considered that those are useful to observe sea state and sea surface height. We have started a research program for GNSS-R applications on oceanographic observations under the contract with MEXT (Ministry of Education Culture, Sports, Science and Technology, JAPAN) and launched a Japanese research consortium, GROWTH (GNSS Reflectometry for Ocean Waves, Tides, and Height). It is aiming to evaluate the capabilities of GNSS-R observations for oceanographic phenomena with different time scales, such as ocean waves (1/10 to tens of seconds), tides (one or half days), and sea surface dynamic height (a few days to years). In situ observations of ocean wave spectrum, wind speed vertical profile, and sea surface height will be quantitatively compared with equivalent estimates from simultaneous GNSS-R measurements. The GROWTH project will utilize different types of observation platforms; marine observation towers (about 20 m height), multi-copters (about 100 to 150 m height), and much higher-altitude CYGNSS data. Cross-platform data, together with in situ oceanographic observations, will be compared after adequate temporal averaging that accounts differences of the footprint sizes and temporal and spatial scales of oceanographic phenomena. This paper will provide overview of the GROWTH project, preliminary test results, obtained by the multi-sensor platform at observation towers, suggest actual footprint sizes and identification of swell. Preparation status of a ground station which will be supplied to receive CYGNSS data

  11. Modeling nonstationary extreme wave heights in present and future climates of Greek Seas

    Directory of Open Access Journals (Sweden)

    Panagiota Galiatsatou

    2016-01-01

    Full Text Available In this study the generalized extreme value (GEV distribution function was used to assess nonstationarity in annual maximum wave heights for selected locations in the Greek Seas, both in the present and future climates. The available significant wave height data were divided into groups corresponding to the present period (1951–2000, a first future period (2001–2050, and a second future period (2051–2100. For each time period, the parameters of the GEV distribution were specified as functions of time-varying covariates and estimated using the conditional density network (CDN. For each location and selected time period, a total number of 29 linear and nonlinear models were fitted to the wave data, for a given combination of covariates. The covariates used in the GEV-CDN models consisted of wind fields resulting from the Regional Climate Model version 3 (RegCM3 developed by the International Center for Theoretical Physics (ICTP with a spatial resolution of 10 km × 10 km, after being processed using principal component analysis (PCA. The results obtained from the best fitted models in the present and future periods for each location were compared, revealing different patterns of relationships between wind components and extreme wave height quantiles in different parts of the Greek Seas and different periods. The analysis demonstrates an increase of extreme wave heights in the first future period as compared with the present period, causing a significant threat to Greek coastal areas in the North Aegean Sea and the Ionian Sea.

  12. Extreme Value Predictions using Monte Carlo Simulations with Artificially Increased Wave Height

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    2010-01-01

    It is well known from linear analyses in a stochastic seaway that the mean out-crossing rate ν(r) of a level r is given by ν(0)exp(-0.5ß2)where the reliability index ß=r/Sr. Here Sr is the standard deviation of the response and, hence, linearly dependent on the sig-nificant wave height Hs. For non...

  13. Automation of measurement of heights waves around a model ship; Mokeisen mawari no hako keisoku no jidoka

    Energy Technology Data Exchange (ETDEWEB)

    Ikehata, M; Kato, M; Yanagida, F [Yokohama National University, Yokohama (Japan). Faculty of Engineering

    1997-10-01

    Trial fabrication and tests were performed on an instrument to automate measurement of heights of waves around a model ship. The currently used electric wave height measuring instrument takes long time for measurement, hence poor in efficiency. The method for processing optical images also has a problem in accuracy. Therefore, a computer controlled system was structured by using AC servo motors in driving the X and Y axes of a traverse equipment. Equipment was fabricated to automate the wave height measurement, in which four servo type wave height meters are installed on a moving rack in the lateral (Y-axial) direction so that wave heights to be measured by four meters can be measured automatically all at once. Wave heights can be measured continuously by moving the moving rack at a constant speed, verifying that wave shapes in longitudinal cross sections can be acquired by only one towing. Time required in the measurements using the instrument was 40 hours as a net time for fixed point measurement and 12 hours for continuous measurement, or 52 hours in total. On the other hand, the time may reach 240 hours for fixed point measurement when the conventional all-point manual traverse equipment is used. Enormous effects were obtained from automating the instrument. Collection of wave height data will continue also on tankers and other types of ships. 2 refs., 8 figs., 1 tab.

  14. Seasonal and Non-Seasonal Generalized Pareto Distribution to Estimate Extreme Significant Wave Height in The Banda Sea

    Science.gov (United States)

    Nursamsiah; Nugroho Sugianto, Denny; Suprijanto, Jusup; Munasik; Yulianto, Bambang

    2018-02-01

    The information of extreme wave height return level was required for maritime planning and management. The recommendation methods in analyzing extreme wave were better distributed by Generalized Pareto Distribution (GPD). Seasonal variation was often considered in the extreme wave model. This research aims to identify the best model of GPD by considering a seasonal variation of the extreme wave. By using percentile 95 % as the threshold of extreme significant wave height, the seasonal GPD and non-seasonal GPD fitted. The Kolmogorov-Smirnov test was applied to identify the goodness of fit of the GPD model. The return value from seasonal and non-seasonal GPD was compared with the definition of return value as criteria. The Kolmogorov-Smirnov test result shows that GPD fits data very well both seasonal and non-seasonal model. The seasonal return value gives better information about the wave height characteristics.

  15. Managing Information Uncertainty in Wave Height Modeling for the Offshore Structural Analysis through Random Set

    Directory of Open Access Journals (Sweden)

    Keqin Yan

    2017-01-01

    Full Text Available This chapter presents a reliability study for an offshore jacket structure with emphasis on the features of nonconventional modeling. Firstly, a random set model is formulated for modeling the random waves in an ocean site. Then, a jacket structure is investigated in a pushover analysis to identify the critical wave direction and key structural elements. This is based on the ultimate base shear strength. The selected probabilistic models are adopted for the important structural members and the wave direction is specified in the weakest direction of the structure for a conservative safety analysis. The wave height model is processed in a P-box format when it is used in the numerical analysis. The models are applied to find the bounds of the failure probabilities for the jacket structure. The propagation of this wave model to the uncertainty in results is investigated in both an interval analysis and Monte Carlo simulation. The results are compared in context of information content and numerical accuracy. Further, the failure probability bounds are compared with the conventional probabilistic approach.

  16. A numerical study on the effects of wave-current-surge interactions on the height and propagation of sea surface waves in Charleston Harbor during Hurricane Hugo 1989

    Science.gov (United States)

    Liu, Huiqing; Xie, Lian

    2009-06-01

    The effects of wave-current interactions on ocean surface waves induced by Hurricane Hugo in and around the Charleston Harbor and its adjacent coastal waters are examined by using a three-dimensional (3D) wave-current coupled modeling system. The 3D storm surge modeling component of the coupled system is based on the Princeton Ocean Model (POM), the wave modeling component is based on the third generation wave model, Simulating WAves Nearshore (SWAN), and the inundation model is adopted from [Xie, L., Pietrafesa, L. J., Peng, M., 2004. Incorporation of a mass-conserving inundation scheme into a three-dimensional storm surge model. J. Coastal Res., 20, 1209-1223]. The results indicate that the change of water level associated with the storm surge is the primary cause for wave height changes due to wave-surge interaction. Meanwhile, waves propagating on top of surge cause a feedback effect on the surge height by modulating the surface wind stress and bottom stress. This effect is significant in shallow coastal waters, but relatively small in offshore deep waters. The influence of wave-current interaction on wave propagation is relatively insignificant, since waves generally propagate in the direction of the surface currents driven by winds. Wave-current interactions also affect the surface waves as a result of inundation and drying induced by the storm. Waves break as waters retreat in regions of drying, whereas waves are generated in flooded regions where no waves would have occurred without the flood water.

  17. Small scale currents and ocean wave heights: from today's models to future satellite observations with CFOSAT and SKIM

    Science.gov (United States)

    Ardhuin, Fabrice; Gille, Sarah; Menemenlis, Dimitris; Rocha, Cesar; Rascle, Nicolas; Gula, Jonathan; Chapron, Bertrand

    2017-04-01

    Tidal currents and large oceanic currents, such as the Agulhas, Gulf Stream and Kuroshio, are known to modify ocean wave properties, causing extreme sea states that are a hazard to navigation. Recent advances in the understanding and modeling capability of ocean currents at scales of 10 km or less have revealed the ubiquitous presence of fronts and filaments. Based on realistic numerical models, we show that these structures can be the main source of variability in significant wave heights at scales less than 200 km, including important variations at 10 km. This current-induced variability creates gradients in wave heights that were previously overlooked and are relevant for extreme wave heights and remote sensing. The spectrum of significant wave heights is found to be of the order of 70⟨Hs ⟩2/(g2⟨Tm0,-1⟩2) times the current spectrum, where ⟨Hs ⟩ is the spatially-averaged significant wave height, ⟨Tm0,-1⟩ is the average energy period, and g is the gravity acceleration. This small scale variability is consistent with Jason-3 and SARAL along-track variability. We will discuss how future satellite mission with wave spectrometers can help observe these wave-current interactions. CFOSAT is due for launch in 2018, and SKIM is a proposal for ESA Earth Explorer 9.

  18. Significant Wave Height under Hurricane Irma derived from SAR Sentinel-1 Data

    Science.gov (United States)

    Lehner, S.; Pleskachevsky, A.; Soloviev, A.; Fujimura, A.

    2017-12-01

    The 2017 Atlantic hurricane season was with three major hurricanes a particular active one. The Category 4 hurricane Irma made landfall on the Florida Keys on September 10th 2017 and was imaged several times by ESAs Sentinel-1 satellites in C-band and the TerraSAR-X satellite in X-band. The high resolution TerraSAR-X imagery showed the footprint of individual tornadoes on the sea surface together with their turbulent wake imaged as a dark line due to increased turbulence. The water-cloud structures of the tornadoes are analyzed and their sea surface structure is compared to optical and IR cloud imagery. An estimate of the wind field using standard XMOD algorithms is provided, although saturating under the strong rain and high wind speed conditions. Imaging the hurricanes by space radar gives the opportunity to observe the sea surface and thus measure the wind field and the sea state under hurricane conditions through the clouds even in this severe weather, although rain features, which are usually not observed in SAR become visible due to damping effects. The Copernicus Sentinel-1 A and B satellites, which are operating in C-band provided several images of the sea surface under hurricane Irma, Jose and Maria. The data were acquired daily and converted into measurements of sea surface wind field u10 and significant wave height Hs over a swath width of 280km about 1000 km along the orbit. The wind field of the hurricanes as derived by CMOD is provided by NOAA operationally on their web server. In the hurricane cases though the wind speed saturates at 20 m/sec and is thus too low in the area of hurricane wind speed. The technique to derive significant wave height is new though and does not show any calibration issues. This technique provides for the first time measurements of the areal coverage and distribution of the ocean wave height as caused by a hurricane on SAR wide swath images. Wave heights up to 10 m were measured under the forward quadrant of the hurricane

  19. The Interaction between the Plane Wave and the Plate with Limited Height in Soil

    Directory of Open Access Journals (Sweden)

    N.A. Lokteva

    2017-03-01

    Full Text Available A solution of the two-dimensional task on interaction between the harmonic wave and the plate with the limited height in soil has been provided. The plate surrounded on both sides with the half-spaces filled with soil medium has been used as a vibro-absorbing obstacle. The mechanical behavior of the plate has been described by S.P. Timoshenko's shift model and the mechanical behavior of soil by a linear elasticity theory equation. The main purpose of the paper is to determine the total acceleration vector field inducted by the penetrated and radiated waves in the second half-space. The mathematical formulation of the task includes a model of upcoming wave, soil medium and plate movement equation, infinity conditions, and conditions of soil contact with obstacle. Conditions of free slip have been taken as the contact conditions between the soil and the obstacle. We have considered a closed system of equations, which includes wave equations for scalar and vector potentials, elasticity theory equations for soil mediums, Koshi's relations, physical law, and plate movement equation. The boundary conditions for the plate correspond to a hinged support. To solve this task, all functions have been expanded in trigonometric series that allowed to obtain potential values in the coefficients of the series. To define the integrations constants, the contact conditions between the obstacle and soil have been used. On the basis of the revealed potentials, we have defined displacements on the boundary between the plate and soil and in other points of the second half-space. The vibro-absorbing properties of the plate have been investigated depending on the frequency of the harmonic wave falling on the plate. From the practical point of view, this task is related to protection of buildings from vibrations formed at a distance from underground railways.

  20. Performance of a data-driven technique to changes in wave height and its effect on beach response

    Directory of Open Access Journals (Sweden)

    Jose M. Horrillo-Caraballo

    2016-01-01

    Full Text Available In this study the medium-term response of beach profiles was investigated at two sites: a gently sloping sandy beach and a steeper mixed sand and gravel beach. The former is the Duck site in North Carolina, on the east coast of the USA, which is exposed to Atlantic Ocean swells and storm waves, and the latter is the Milford-on-Sea site at Christchurch Bay, on the south coast of England, which is partially sheltered from Atlantic swells but has a directionally bimodal wave exposure. The data sets comprise detailed bathymetric surveys of beach profiles covering a period of more than 25 years for the Duck site and over 18 years for the Milford-on-Sea site. The structure of the data sets and the data-driven methods are described. Canonical correlation analysis (CCA was used to find linkages between the wave characteristics and beach profiles. The sensitivity of the linkages was investigated by deploying a wave height threshold to filter out the smaller waves incrementally. The results of the analysis indicate that, for the gently sloping sandy beach, waves of all heights are important to the morphological response. For the mixed sand and gravel beach, filtering the smaller waves improves the statistical fit and it suggests that low-height waves do not play a primary role in the medium-term morphological response, which is primarily driven by the intermittent larger storm waves.

  1. Performance of a data-driven technique applied to changes in wave height and its effect on beach response

    Directory of Open Access Journals (Sweden)

    José M. Horrillo-Caraballo

    2016-01-01

    Full Text Available In this study the medium-term response of beach profiles was investigated at two sites: a gently sloping sandy beach and a steeper mixed sand and gravel beach. The former is the Duck site in North Carolina, on the east coast of the USA, which is exposed to Atlantic Ocean swells and storm waves, and the latter is the Milford-on-Sea site at Christchurch Bay, on the south coast of England, which is partially sheltered from Atlantic swells but has a directionally bimodal wave exposure. The data sets comprise detailed bathymetric surveys of beach profiles covering a period of more than 25 years for the Duck site and over 18 years for the Milford-on-Sea site. The structure of the data sets and the data-driven methods are described. Canonical correlation analysis (CCA was used to find linkages between the wave characteristics and beach profiles. The sensitivity of the linkages was investigated by deploying a wave height threshold to filter out the smaller waves incrementally. The results of the analysis indicate that, for the gently sloping sandy beach, waves of all heights are important to the morphological response. For the mixed sand and gravel beach, filtering the smaller waves improves the statistical fit and it suggests that low-height waves do not play a primary role in the medium-term morphological response, which is primarily driven by the intermittent larger storm waves.

  2. Estimates of ocean wave heights and attenuation in sea ice using the SAR wave mode on Sentinel-1A

    Science.gov (United States)

    Ardhuin, Fabrice; Collard, Fabrice; Chapron, Bertrand; Girard-Ardhuin, Fanny; Guitton, Gilles; Mouche, Alexis; Stopa, Justin E.

    2015-04-01

    Swell evolution from the open ocean into sea ice is poorly understood, in particular the amplitude attenuation expected from scattering and dissipation. New synthetic aperture radar (SAR) data from Sentinel-1A wave mode reveal intriguing patterns of bright oscillating lines shaped like instant noodles. We investigate cases in which the oscillations are in the azimuth direction, around a straight line in the range direction. This observation is interpreted as the distortion by the SAR processing of crests from a first swell, due to the presence of a second swell. Since deviations from a straight line should be proportional to the orbital velocity toward the satellite, swell height can be estimated, from 1.5 to 5 m in the present case. The evolution of this 13 s period swell across the ice pack is consistent with an exponential attenuation on a length scale of 200 km.

  3. Evaluation and adjustment of altimeter measurement and numerical hindcast in wave height trend estimation in China's coastal seas

    Science.gov (United States)

    Li, Shuiqing; Guan, Shoude; Hou, Yijun; Liu, Yahao; Bi, Fan

    2018-05-01

    A long-term trend of significant wave height (SWH) in China's coastal seas was examined based on three datasets derived from satellite measurements and numerical hindcasts. One set of altimeter data were obtained from the GlobWave, while the other two datasets of numerical hindcasts were obtained from the third-generation wind wave model, WAVEWATCH III, forced by wind fields from the Cross-Calibrated Multi-Platform (CCMP) and NCEP's Climate Forecast System Reanalysis (CFSR). The mean and extreme wave trends were estimated for the period 1992-2010 with respect to the annual mean and the 99th-percentile values of SWH, respectively. The altimeter wave trend estimates feature considerable uncertainties owing to the sparse sampling rate. Furthermore, the extreme wave trend tends to be overestimated because of the increasing sampling rate over time. Numerical wave trends strongly depend on the quality of the wind fields, as the CCMP waves significantly overestimate the wave trend, whereas the CFSR waves tend to underestimate the trend. Corresponding adjustments were applied which effectively improved the trend estimates from the altimeter and numerical data. The adjusted results show generally increasing mean wave trends, while the extreme wave trends are more spatially-varied, from decreasing trends prevailing in the South China Sea to significant increasing trends mainly in the East China Sea.

  4. Global trends in significant wave height and marine wind speed from the ERA-20CM

    Science.gov (United States)

    Aarnes, Ole Johan; Breivik, Øyvind

    2016-04-01

    The ERA-20CM is one of the latest additions to the ERA-series produced at the European Center for Medium-Range Weather Forecasts (ECMWF). This 10 member ensemble is generated with a version of the Integrated Forecast System (IFS), a coupled atmosphere-wave model. The model integration is run as a AMIP (Atmospheric Model Intercomparison Project) constrained by CMIP5 recommended radiative forcing and different realizations of sea-surface temperature (SST) and sea-ice cover (SIC) prescribed by the HadISST2 (Met Office Hadley Center). While the ERA-20CM is unable to reproduce the actual synoptic conditions, it is designed to offer a realistic statistical representation of the past climate, spanning the period 1899-2010. In this study we investigate global trends in significant wave height and marine wind speed based on ERA-20CM, using monthly mean data, upper percentiles and monthly/annual maxima. The aim of the study is to assess the quality of the trends and how these estimates are affected by different SST and SIC. Global trends are compared against corresponding estimates obtained with ERA-Interim (1979-2009), but also crosschecked against ERA-20C - an ECMWF pilot reanalysis of the 20th-century, known to most trustworthy in the Northern Hemisphere extratropics. Over the period 1900-2009, the 10 member ensemble yields trends mainly within +/- 5% per century. However, significant trends of opposite signs are found locally. Certain areas, like the eastern equatorial Pacific, highly affected by the El Niño Southern Oscillation, show stronger trends. In general, trends based on statistical quantities further into the tail of the distribution are found less reliable.

  5. Wave Height Estimation from Shadowing Based on the Acquired X-Band Marine Radar Images in Coastal Area

    Directory of Open Access Journals (Sweden)

    Yanbo Wei

    2017-08-01

    Full Text Available In this paper, the retrieving significant wave height from X-band marine radar images based on shadow statistics is investigated, since the retrieving accuracy can not be seriously affected by environmental factors and the method has the advantage of without any external reference to calibrate. However, the accuracy of the significant wave height estimated from the radar image acquired at the near-shore area is not ideal. To solve this problem, the effect of water depth is considered in the theoretical derivation of estimated wave height based on the sea surface slope. And then, an improved retrieving algorithm which is suitable for both in deep water area and shallow water area is developed. In addition, the radar data are sparsely processed in advance in order to achieve high quality edge image for the requirement of shadow statistic algorithm, since the high resolution radar images will lead to angle-blurred for the image edge detection and time-consuming in the estimation of sea surface slope. The data acquired from Pingtan Test Base in Fujian Province were used to verify the effectiveness of the proposed algorithm. The experimental results demonstrate that the improved method which takes into account the water depth is more efficient and effective and has better performance for retrieving significant wave height in the shallow water area, compared to the in situ buoy data as the ground truth and that of the existing shadow statistic method.

  6. Modelling the effect of suspended load transport and tidal asymmetry on the equilibrium tidal sand wave height

    NARCIS (Netherlands)

    van Gerwen, W.; Borsje, Bastiaan Wijnand; Damveld, Johan Hendrik; Hulscher, Suzanne J.M.H.

    2018-01-01

    Tidal sand waves are rhythmic bed forms found in shallow sandy coastal seas, reaching heights up to ten meters and migration rates of several meters per year. Because of their dynamic behaviour, unravelling the physical processes behind the growth of these bed forms is of particular interest to

  7. [P wave dispersion increased in childhood depending on blood pressure, weight, height, and cardiac structure and function].

    Science.gov (United States)

    Chávez-González, Elibet; González-Rodríguez, Emilio; Llanes-Camacho, María Del Carmen; Garí-Llanes, Merlin; García-Nóbrega, Yosvany; García-Sáez, Julieta

    2014-01-01

    Increased P wave dispersion are identified as a predictor of atrial fibrillation. There are associations between hypertension, P wave dispersion, constitutional and echocardiographic variables. These relationships have been scarcely studied in pediatrics. The aim of this study was to determine the relationship between P wave dispersion, blood pressure, echocardiographic and constitutional variables, and determine the most influential variables on P wave dispersion increases in pediatrics. In the frame of the PROCDEC II project, children from 8 to 11 years old, without known heart conditions were studied. Arterial blood pressure was measured in all the children; a 12-lead surface electrocardiogram and an echocardiogram were done as well. Left ventricular mass index mean values for normotensive (25.91±5.96g/m(2.7)) and hypertensive (30.34±8.48g/m(2.7)) showed significant differences P=.000. When we add prehypertensive and hypertensive there are 50.38% with normal left ventricular mass index and P wave dispersion was increased versus 13.36% of normotensive. Multiple regression demonstrated that the mean blood pressure, duration of A wave of mitral inflow, weight and height have a value of r=0.88 as related to P wave dispersion. P wave dispersion is increased in pre- and hypertensive children compared to normotensive. There are pre- and hypertensive patients with normal left ventricular mass index and increased P wave dispersion. Mean arterial pressure, duration of the A wave of mitral inflow, weight and height are the variables with the highest influence on increased P wave dispersion. Copyright © 2013 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

  8. Climate change signal and uncertainty in CMIP5-based projections of global ocean surface wave heights

    Science.gov (United States)

    Wang, Xiaolan L.; Feng, Yang; Swail, Val R.

    2015-05-01

    This study uses the analysis of variance approaches to quantify the climate change signal and uncertainty in multimodel ensembles of statistical simulations of significant wave height (Hs), which are based on the CMIP5 historical, RCP4.5 and RCP8.5 forcing scenario simulations of sea level pressure. Here the signal of climate change refers to the temporal variations caused by the prescribed forcing. "Significant" means "significantly different from zero at 5% level." In a four-model ensemble of Hs simulations, the common signal—the signal that is simulated in all the four models—is found to strengthen over time. For the historical followed by RCP8.5 scenario, the common signal in annual mean Hs is found to be significant in 16.6% and 82.2% of the area by year 2005 and 2099, respectively. The global average of the variance proportion of the common signal increases from 0.75% in year 2005 to 12.0% by year 2099. The signal is strongest in the eastern tropical Pacific (ETP), featuring significant increases in both the annual mean and maximum of Hs in this region. The climate model uncertainty (i.e., intermodel variability) is significant nearly globally; its magnitude is comparable to or greater than that of the common signal in most areas, except in the ETP where the signal is much larger. In a 20-model ensemble of Hs simulations for the period 2006-2099, the model uncertainty is found to be significant globally; it is about 10 times as large as the variability between the RCP4.5 and RCP8.5 scenarios. The copyright line for this article was changed on 10 JUNE 2015 after original online publication.

  9. Final Report for Project: Impacts of stratification and non-equilibrium winds and waves on hub-height winds

    Energy Technology Data Exchange (ETDEWEB)

    Patton, Edward G. [Univ. Corporation for Atmospheric Research, Boulder, CO (United States)

    2015-07-14

    This project used a combination of turbulence-resolving large-eddy simulations, single-column modeling (where turbulence is parameterized), and currently available observations to improve, assess, and develop a parameterization of the impact of non-equilibrium wave states and stratification on the buoy-observed winds to establish reliable wind data at the turbine hub-height level. Analysis of turbulence-resolving simulations and observations illuminates the non-linear coupling between the atmosphere and the undulating sea surface. This analysis guides modification of existing boundary layer parameterizations to include wave influences for upward extrapolation of surface-based observations through the turbine layer. Our surface roughness modifications account for the interaction between stratification and the effects of swell’s amplitude and wavelength as well as swell’s relative motion with respect to the mean wind direction. The single-column version of the open source Weather and Research Forecasting (WRF) model (Skamarock et al., 2008) serves as our platform to test our proposed planetary boundary layer parameterization modifications that account for wave effects on marine atmospheric boundary layer flows. WRF has been widely adopted for wind resource analysis and forecasting. The single column version is particularly suitable to development, analysis, and testing of new boundary layer parameterizations. We utilize WRF’s single-column version to verify and validate our proposed modifications to the Mellor-Yamada-Nakanishi-Niino (MYNN) boundary layer parameterization (Nakanishi and Niino, 2004). We explore the implications of our modifications for two-way coupling between WRF and wave models (e.g.,Wavewatch III). The newly implemented parameterization accounting for marine atmospheric boundary layer-wave coupling is then tested in three-dimensional WRF simulations at grid sizes near 1 km. These simulations identify the behavior of simulated winds at the

  10. Econometric analysis of the changing effects in wind strength and significant wave height on the probability of casualty in shipping.

    Science.gov (United States)

    Knapp, Sabine; Kumar, Shashi; Sakurada, Yuri; Shen, Jiajun

    2011-05-01

    This study uses econometric models to measure the effect of significant wave height and wind strength on the probability of casualty and tests whether these effects changed. While both effects are in particular relevant for stability and strength calculations of vessels, it is also helpful for the development of ship construction standards in general to counteract increased risk resulting from changing oceanographic conditions. The authors analyzed a unique dataset of 3.2 million observations from 20,729 individual vessels in the North Atlantic and Arctic regions gathered during the period 1979-2007. The results show that although there is a seasonal pattern in the probability of casualty especially during the winter months, the effect of wind strength and significant wave height do not follow the same seasonal pattern. Additionally, over time, significant wave height shows an increasing effect in January, March, May and October while wind strength shows a decreasing effect, especially in January, March and May. The models can be used to simulate relationships and help understand the relationships. This is of particular interest to naval architects and ship designers as well as multilateral agencies such as the International Maritime Organization (IMO) that establish global standards in ship design and construction. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Verification of model wave heights with long-term moored buoy data: Application to wave field over the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Samiksha, S.V.; Polnikov, V.G.; Vethamony, P.; Rashmi, R.; Pogarskii, F.; Sudheesh, K.

    . Res. 106(C6), 11659-11676 Babanin, A.V., 2011. Breaking and Dissipation of Ocean Surface Waves. Book, Cambridge University Press, 480p Banner, M. L., Gemmrich, J. R., and Farmer, D. M., 2002. Multiscale measurements of ocean wave breaking...

  12. On the retrieval of significant wave heights from spaceborne Synthetic Aperture Radar using the Max-Planck Institut algorithm.

    Science.gov (United States)

    Violante-Carvalho, Nelson

    2005-12-01

    Synthetic Aperture Radar (SAR) onboard satellites is the only source of directional wave spectra with continuous and global coverage. Millions of SAR Wave Mode (SWM) imagettes have been acquired since the launch in the early 1990's of the first European Remote Sensing Satellite ERS-1 and its successors ERS-2 and ENVISAT, which has opened up many possibilities specially for wave data assimilation purposes. The main aim of data assimilation is to improve the forecasting introducing available observations into the modeling procedures in order to minimize the differences between model estimates and measurements. However there are limitations in the retrieval of the directional spectrum from SAR images due to nonlinearities in the mapping mechanism. The Max-Planck Institut (MPI) scheme, the first proposed and most widely used algorithm to retrieve directional wave spectra from SAR images, is employed to compare significant wave heights retrieved from ERS-1 SAR against buoy measurements and against the WAM wave model. It is shown that for periods shorter than 12 seconds the WAM model performs better than the MPI, despite the fact that the model is used as first guess to the MPI method, that is the retrieval is deteriorating the first guess. For periods longer than 12 seconds, the part of the spectrum that is directly measured by SAR, the performance of the MPI scheme is at least as good as the WAM model.

  13. 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.

    Geosat altimeter data for the period November 1986-October 1987 over the north Indian Ocean have been processed to retrieve wind speeds and significant wave heights. Smoothed Brown algorithm is used to retrieve wind speeds from back...

  14. The impact of North Atlantic wind and cyclone trends on European precipitation and significant wave height in the Atlantic.

    Science.gov (United States)

    Trigo, Ricardo M; Valente, Maria A; Trigo, Isabel F; Miranda, Pedro M A; Ramos, Alexandre M; Paredes, Daniel; García-Herrera, Ricardo

    2008-12-01

    An analysis of the frequency of cyclones and surface wind velocity for the Euro-Atlantic sector is performed by means of an objective methodology. Monthly and seasonal trends of cyclones and wind speed magnitude are computed and trends between 1960 and 2000 evaluated. Results reveal a significant frequency decrease (increase) in the western Mediterranean (Greenland and Scandinavia), particularly in December, February, and March. Seasonal and monthly analysis of wind magnitude trends shows similar spatial patterns. We show that these changes in the frequency of low-pressure centers and the associated wind patterns are partially responsible for trends in the significant height of waves. Throughout the extended winter months (October-March), regions with positive (negative) wind magnitude trends, of up to 5 cm/s/year, often correspond to regions of positive (negative) significant wave height trends. The cyclone and wind speed trends computed for January-March are well matched by the corresponding trends in significant wave height, with February being the month with the highest trends (negative south of lat 50 degrees N up to -3 cm/year, and positive up to 5 cm/year just north of Scotland). Trends in European precipitation are assessed using the Climatic Research Unit data set. The results of the assessment emphasize the link with the corresponding tendencies of cyclone frequencies. Finally, it is shown that these changes are associated, to a large extent, with the preferred phases of major large-scale atmospheric circulation modes, particularly with the North Atlantic Oscillation, the eastern Atlantic pattern, and the Scandinavian pattern.

  15. Trends in significant wave height and surface wind speed in the China Seas between 1988 and 2011

    Science.gov (United States)

    Zheng, Chongwei; Zhang, Ren; Shi, Weilai; Li, Xin; Chen, Xuan

    2017-10-01

    Wind and waves are key components of the climate system as they drive air-sea interactions and influence weather systems and atmospheric circulation. In marine environments, understanding surface wind and wave fields and their evolution over time is important for conducting safe and efficient human activities, such as navigation and engineering. This study considers long-term trends in the sea surface wind speed (WS) and significant wave height (SWH) in the China Seas over the period 1988-2011 using the Cross-Calibrated Multi-Platform (CCMP) ocean surface wind product and a 24-year hindcast wave dataset obtained from the WAVEWATCH-III (WW3) wave model forced with CCMP winds. The long-term trends in WS and SWH in the China Seas are analyzed over the past 24 years to provide a reference point from which to assess future climate change and offshore wind and wave energy resource development in the region. Results demonstrate that over the period 1988-2011 in the China Seas: 1) WS and SWH showed a significant increasing trend of 3.38 cm s-1 yr-1 and 1.52 cm yr-1, respectively; 2) there were notable regional differences in the long-term trends of WS and SWH; 3) areas with strong increasing trends were located mainly in the middle of the Tsushima Strait, the northern and southern areas of the Taiwan Strait, and in nearshore regions of the northern South China Sea; and 4) the long-term trend in WS was closely associated with El Niño and a significant increase in the occurrence of gale force winds in the region.

  16. Trends of wave height and period in the Central Arabian Sea from 1996 to 2012: A study based on satellite altimeter data

    Digital Repository Service at National Institute of Oceanography (India)

    Hithin, N.K.; SanilKumar, V.; Shanas, P.R.

    The variability of annual maximum and annual mean significant wave height (SWH) and wave period in the Central Arabian Sea is studied using satellite altimeter data from 1996 to 2012 at a deep water (water depth~3500 m) buoy location (15.5°N, 69...

  17. Wave Height and Water Level Variability on Lakes Michigan and St Clair

    Science.gov (United States)

    2012-10-01

    Observations: http://www.ssec.wisc.edu/sose/glwx_activity.html 4. NASA Atlas of Extratropical Storm Tracks: http://data.giss.nasa.gov/stormtracks...term meteorological, ice, wave, and water level measurements. 15. SUBJECT TERMS Base flood elevation Coastal flood Extratropical storms Great...Box 1027 Detroit, MI 48231-1027 ERDC/CHL TR-12-23 ii Abstract The Great Lakes are subject to coastal flooding as a result of severe storms

  18. Links of the significant wave height distribution in the Mediterranean sea with the Northern Hemisphere teleconnection patterns

    Directory of Open Access Journals (Sweden)

    P. Lionello

    2008-06-01

    Full Text Available This study analyzes the link between the SWH (Significant Wave Height distribution in the Mediterranean Sea during the second half of the 20th century and the Northern Hemisphere SLP (Sea Level Pressure teleconnection patterns.

    The SWH distribution is computed using the WAM (WAve Model forced by the surface wind fields provided by the ERA-40 reanalysis for the period 1958–2001. The time series of mid-latitude teleconnection patterns are downloaded from the NOAA web site. This study shows that several mid-latitude patterns are linked to the SWH field in the Mediterranean, especially in its western part during the cold season: East Atlantic Pattern (EA, Scandinavian Pattern (SCA, North Atlantic Oscillation (NAO, East Atlantic/West Russia Pattern (EA/WR and East Pacific/ North Pacific Pattern (EP/NP. Though the East Atlantic pattern exerts the largest influence, it is not sufficient to characterize the dominant variability. NAO, though relevant, has an effect smaller than EA and comparable to other patterns. Some link results from possibly spurious structures. Patterns which have a very different global structure are associated to similar spatial features of the wave variability in the Mediterranean Sea. These two problems are, admittedly, shortcomings of this analysis, which shows the complexity of the response of the Mediterranean SWH to global scale SLP teleconnection patterns.

  19. Seasonal and height variation of gravity wave activities observed by a meteor radar at King Sejong Station (62°S, 57°W), Antarctica

    Science.gov (United States)

    Kim, Y.; Lee, C.; Kim, J.; Choi, J.; Jee, G.

    2010-12-01

    We have analyzed wind data from individual meteor echoes detected by a meteor radar at King Sejong Station, Antarctica to measure gravity wave activity in the mesopause region. Wind data in the meteor altitudes has been obtained routinely by the meteor radar since its installation in March 2007. The mean variances in the wind data that were filtered for large scale motions (mean winds and tides) can be regarded as the gravity wave activity. Monthly mean gravity wave activities show strong seasonal and height dependences in the altitude range of 80 to 100 km. The gravity wave activities except summer monotonically increase with altitude, which is expected since decreasing atmospheric densities cause wave amplitudes to increase. During summer (Dec. - Feb.) the height profiles of gravity wave activities show a minimum near 90 - 95 km, which may be due to different zonal wind and strong wind shear near 80 - 95 km. Our gravity wave activities are generally stronger than those of the Rothera station, implying sensitive dependency on location. The difference may be related to gravity wave sources in the lower atmosphere near Antarctic vortex.

  20. Decadal variability of extreme wave height representing storm severity in the northeast Atlantic and North Sea since the foundation of the Royal Society

    Science.gov (United States)

    Santo, H.; Taylor, P. H.; Gibson, R.

    2016-09-01

    Long-term estimation of extreme wave height remains a key challenge because of the short duration of available wave data, and also because of the possible impact of climate variability on ocean waves. Here, we analyse storm-based statistics to obtain estimates of extreme wave height at locations in the northeast Atlantic and North Sea using the NORA10 wave hindcast (1958-2011), and use a 5 year sliding window to examine temporal variability. The decadal variability is correlated to the North Atlantic oscillation and other atmospheric modes, using a six-term predictor model incorporating the climate indices and their Hilbert transforms. This allows reconstruction of the historic extreme climate back to 1661, using a combination of known and proxy climate indices. Significant decadal variability primarily driven by the North Atlantic oscillation is observed, and this should be considered for the long-term survivability of offshore structures and marine renewable energy devices. The analysis on wave climate reconstruction reveals that the variation of the mean, 99th percentile and extreme wave climates over decadal time scales for locations close to the dominant storm tracks in the open North Atlantic are comparable, whereas the wave climates for the rest of the locations including the North Sea are rather different.

  1. Numerical simulation of the temperature, electron density, and electric field distributions near the ionospheric reflection height after turn-on of a powerful HF wave

    International Nuclear Information System (INIS)

    Muldrew, D.B.

    1986-01-01

    The time variation of the electron temperature profile in the ionosphere following turn-on of a powerful 1-s HF pulse is determined numerically from the energy balance equation. Using this and the equations of motion and continuity for a plasma, the effect of heating and the pondermotive force of a powerful HF wave on the electron density and electric field distributions are determined by numerical simulation. The temperature variation and ponderomotive force modify the density distribution, and this new density distribution, in turn, modifies the electric field distribution of the HF wave. The density deviations grow for a few hundred milliseconds after HF turn-on and then begin to fluctuate in time. At all heights the wave number of the density deviations is approximately twice the wave number of the HF wave. For electric fields near reflection of about 6.0 V/m, the electric field distribution becomes complicated, apparently depending on Bragg scattering of the HF wave from the density deviations. Density impulses propagate away (up and down) from electric field maxima, at the ion thermal velocity, at both turn-on and turn-off of the HF wave

  2. Long-Term Changes in the Extreme Significant Wave Heights on the Western North Pacific: Impacts of Tropical Cyclone Activity and ENSO

    Science.gov (United States)

    Yang, Sinil; Oh, Jaiho

    2018-02-01

    Seasonal extreme wave statistics were reproduced by using the 25-km-grid global wave model of WAVEWATCH-III. The results showed that the simulated wave dataset for the present climate (1979-2009) was similar to Climate Forecast System Reanalysis (CFSR) wave data. Statistics such as the root mean squared error (RMSE) and correlation coefficient (CC) over the western North Pacific (WNP) basin were 0.5 m and 0.69 over the analysis domain. The largest trends and standard deviation were around the southern coast of Japan and western edge of the WNP. Linear regression analysis was employed to identify the relationship between the leading principal components (PCs) of significant wave heights (SWHs) in the peak season of July to September and sea surface temperature (SST) anomalies in the equatorial Pacific. The results indicated that the inter-annual variability of SWH can be associated with the El Niño-Southern Oscillation in the peak season. The CC between the first PC of the SWH and anomalies in the Nino 3.4 SST index was also significant at a 99% confidence level. Significant variations in the SWH are affected by tropical cyclones (TCs) caused by increased SST anomalies. The genesis and development of simulated TCs can be important to the variation in SWHs for the WNP in the peak season. Therefore, we can project the variability of SWHs through TC activity based on changes in SST conditions for the equatorial Pacific in the future.

  3. Mobility and height detection of particle labels in an optical evanescent wave biosensor with single-label resolution

    NARCIS (Netherlands)

    van Ommering, K.; Somers, P.A.; Koets, M.; Schleipen, J.J.H.B.; IJzendoorn, van L.J.; Prins, M.W.J.

    2010-01-01

    Particle labels are used in biosensors to detect the presence and concentration of analyte molecules. In this paper we demonstrate an optical technique to measure the mobility and height of bound particle labels on a biosensor surface with single-label resolution. The technique is based on the

  4. Significant wave height data from bottom-mounted pressure sensors at three sites in progressively deeper locations along the Outer Reef in Kailua Bay, Oahu, Hawaii from 28 September 2000 to 06 October 2000 (NODC Accession 0000347)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wave height and other data were collected at fixed platforms in the Coastal Waters of Hawaii and Northeast Pacific Ocean from September 28, 2000 to October 06, 2000....

  5. Mobility and height detection of particle labels in an optical evanescent wave biosensor with single-label resolution

    Energy Technology Data Exchange (ETDEWEB)

    Van Ommering, Kim; Koets, Marjo; Schleipen, Jean J H B; Prins, Menno W J [Philips Research Laboratories, 5656 AE Eindhoven (Netherlands); Somers, Philip A; Van IJzendoorn, Leo J, E-mail: menno.prins@philips.co [Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands)

    2010-04-21

    Particle labels are used in biosensors to detect the presence and concentration of analyte molecules. In this paper we demonstrate an optical technique to measure the mobility and height of bound particle labels on a biosensor surface with single-label resolution. The technique is based on the detection of the particle-induced light scattering in an optical evanescent field. We show that the thermal particle motion in the optical evanescent field leads to intensity fluctuations that can accurately be detected. The technique is demonstrated using 290 bp (99 nm) DNA as an analyte and using polystyrene particles and magnetic particles with diameters between 500 and 1000 nm as labels. The particle intensity histograms show that quantitative height measurements are obtained for particles with uniform optical properties, and the intensity versus position plots reflect the analyte-antibody orientation and the analyte flexibility. The novel optical detection technique will lead to biosensors with very high sensitivity and specificity.

  6. Trends in surface wind speed and significant wave height as revealed by ERA-Interim wind wave hindcast in the Central Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Shanas, P.R.; SanilKumar, V.

    height. The area average analysis is carried out to investigate the sensitivity of the identified trend results for the point location and found similar trends for extreme wind speed and SWH. The high (>5 m) annual maximum SWH in the study area...

  7. Projecting of wave height and water level on reef-lined coasts due to intensified tropical cyclones and sea level rise in Palau to 2100

    Directory of Open Access Journals (Sweden)

    C. Hongo

    2018-03-01

    Full Text Available Tropical cyclones (TCs and sea level rise (SLR cause major problems including beach erosion, saltwater intrusion into groundwater, and damage to infrastructure in coastal areas. The magnitude and extent of damage is predicted to increase as a consequence of future climate change and local factors. Upward reef growth has attracted attention for its role as a natural breakwater, reducing the risks of natural disasters to coastal communities. However, projections of change in the risk to coastal reefs under conditions of intensified TCs and SLR are poorly quantified. In this study we projected the wave height and water level on Melekeok reef in the Palau Islands by 2100, based on wave simulations under intensified TCs (significant wave height at the outer ocean: SWHo = 8.7–11.0 m; significant wave period at the outer ocean: SWPo = 13–15 s and SLR (0.24–0.98 m. To understand effects of upward reef growth on the reduction of the wave height and water level, the simulation was conducted for two reef condition scenarios: a degraded reef and a healthy reef. Moreover, analyses of reef growth based on a drilled core provided an assessment of the coral community and rate of reef production necessary to reduce the risk from TCs and SLR on the coastal areas. According to our calculations under intensified TCs and SLR by 2100, significant wave heights at the reef flat (SWHr will increase from 1.05–1.24 m at present to 2.14 m if reefs are degraded. Similarly, by 2100 the water level at the shoreline (WLs will increase from 0.86–2.10 m at present to 1.19–3.45 m if reefs are degraded. These predicted changes will probably cause beach erosion, saltwater intrusion into groundwater, and damage to infrastructure, because the coastal village is located at  ∼ 3 m above the present mean sea level. These findings imply that even if the SWHr is decreased by only 0.1 m by upward reef growth, it will probably reduce the risks of

  8. Projecting of wave height and water level on reef-lined coasts due to intensified tropical cyclones and sea level rise in Palau to 2100

    Science.gov (United States)

    Hongo, Chuki; Kurihara, Haruko; Golbuu, Yimnang

    2018-03-01

    Tropical cyclones (TCs) and sea level rise (SLR) cause major problems including beach erosion, saltwater intrusion into groundwater, and damage to infrastructure in coastal areas. The magnitude and extent of damage is predicted to increase as a consequence of future climate change and local factors. Upward reef growth has attracted attention for its role as a natural breakwater, reducing the risks of natural disasters to coastal communities. However, projections of change in the risk to coastal reefs under conditions of intensified TCs and SLR are poorly quantified. In this study we projected the wave height and water level on Melekeok reef in the Palau Islands by 2100, based on wave simulations under intensified TCs (significant wave height at the outer ocean: SWHo = 8.7-11.0 m; significant wave period at the outer ocean: SWPo = 13-15 s) and SLR (0.24-0.98 m). To understand effects of upward reef growth on the reduction of the wave height and water level, the simulation was conducted for two reef condition scenarios: a degraded reef and a healthy reef. Moreover, analyses of reef growth based on a drilled core provided an assessment of the coral community and rate of reef production necessary to reduce the risk from TCs and SLR on the coastal areas. According to our calculations under intensified TCs and SLR by 2100, significant wave heights at the reef flat (SWHr) will increase from 1.05-1.24 m at present to 2.14 m if reefs are degraded. Similarly, by 2100 the water level at the shoreline (WLs) will increase from 0.86-2.10 m at present to 1.19-3.45 m if reefs are degraded. These predicted changes will probably cause beach erosion, saltwater intrusion into groundwater, and damage to infrastructure, because the coastal village is located at ˜ 3 m above the present mean sea level. These findings imply that even if the SWHr is decreased by only 0.1 m by upward reef growth, it will probably reduce the risks of costal damages. Our results showed that a healthy reef

  9. Scenario based tsunami wave height estimation towards hazard evaluation for the Hellenic coastline and examples of extreme inundation zones in South Aegean

    Science.gov (United States)

    Melis, Nikolaos S.; Barberopoulou, Aggeliki; Frentzos, Elias; Krassanakis, Vassilios

    2016-04-01

    A scenario based methodology for tsunami hazard assessment is used, by incorporating earthquake sources with the potential to produce extreme tsunamis (measured through their capacity to cause maximum wave height and inundation extent). In the present study we follow a two phase approach. In the first phase, existing earthquake hazard zoning in the greater Aegean region is used to derive representative maximum expected earthquake magnitude events, with realistic seismotectonic source characteristics, and of greatest tsunamigenic potential within each zone. By stacking the scenario produced maximum wave heights a global maximum map is constructed for the entire Hellenic coastline, corresponding to all expected extreme offshore earthquake sources. Further evaluation of the produced coastline categories based on the maximum expected wave heights emphasizes the tsunami hazard in selected coastal zones with important functions (i.e. touristic crowded zones, industrial zones, airports, power plants etc). Owing to its proximity to the Hellenic Arc, many urban centres and being a popular tourist destination, Crete Island and the South Aegean region are given a top priority to define extreme inundation zoning. In the second phase, a set of four large coastal cities (Kalamata, Chania, Heraklion and Rethymno), important for tsunami hazard, due i.e. to the crowded beaches during the summer season or industrial facilities, are explored towards preparedness and resilience for tsunami hazard in Greece. To simulate tsunamis in the Aegean region (generation, propagation and runup) the MOST - ComMIT NOAA code was used. High resolution DEMs for bathymetry and topography were joined via an interface, specifically developed for the inundation maps in this study and with similar products in mind. For the examples explored in the present study, we used 5m resolution for the topography and 30m resolution for the bathymetry, respectively. Although this study can be considered as

  10. Comments on ‘Temporal significant wave height estimation from wind speed by perceptron Kalman filtering’ by A. Altunkaynak and M. Ozger, Ocean Engineering, Vol. 31(10); 2004,1245-1255

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.

    wind speed. Interestingly the PKF model is a two layered network (input and output) without hidden layer. Also it is a fact that numerical or physical models have restrictions by certain assumptions and conditions, whereas artificial neural network... is shown by Tsai et al (2002). They have carried out forecasting of significant wave heights and periods at a desired location directly from the observed wave records using a supervised artificial neural network with error back-propagation procedures...

  11. Wuthering Heights

    NARCIS (Netherlands)

    Bronte, Emily

    2005-01-01

    Wuthering Heights tells the story of a romance between two youngsters: Catherine Earnshaw and an orphan boy, Heathcliff. After she rejects him for a boy from a better background he develops a lust for revenge that takes over his life. In attempting to win her back and destroy those he blames for his

  12. Sub-seasonal prediction of significant wave heights over the Western Pacific and Indian Oceans, part II: The impact of ENSO and MJO

    Science.gov (United States)

    Shukla, Ravi P.; Kinter, James L.; Shin, Chul-Su

    2018-03-01

    This study evaluates the effect of El Niño and the Southern Oscillation (ENSO) and Madden Julian Oscillation (MJO) events on 14-day mean significant wave height (SWH) at 3 weeks lead time (Wk34) over the Western Pacific and Indian Oceans using the National Centers for Environmental Prediction (NCEP) Climate Forecast System, version 2 (CFSv2). The WAVEWATCH-3 (WW3) model is forced with daily 10m-winds predicted by a modified version of CFSv2 that is initialized with multiple ocean analyses in both January and May for 1979-2008. A significant anomaly correlation of predicted and observed SWH anomalies (SWHA) at Wk34 lead-time is found over portions of the domain, including the central western Pacific, South China Sea (SCS), Bay of Bengal (BOB) and southern Indian Ocean (IO) in January cases, and over BOB, equatorial western Pacific, the Maritime Continent and southern IO in May cases. The model successfully predicts almost all the important features of the observed composite SWHA during El Niño events in January, including negative SWHA in the central IO where westerly wind anomalies act on an easterly mean state, and positive SWHA over the southern Ocean (SO) where westerly wind anomalies act on a westerly mean state. The model successfully predicts the sign and magnitude of SWHA at Wk34 lead-time in May over the BOB and SCS in composites of combined phases-2-3 and phases-6-7 of MJO. The observed leading mode of SWHA in May and the third mode of SWHA in January are influenced by the combined effects of ENSO and MJO. Based on spatial and temporal correlations, the spatial patterns of SWHA in the model at Wk34 in both January and May are in good agreement with the observations over the equatorial western Pacific, equatorial and southern IO, and SO.

  13. Comparison of gridded multi-mission and along-track mono-mission satellite altimetry wave heights with in situ near-shore buoy data.

    Digital Repository Service at National Institute of Oceanography (India)

    Shanas, P.R.; SanilKumar, V.; Hithin, N.K.

    and studied the validity of these observations against ship-reported and buoy data. Many studies have been undertaken on how best to use the data available from satellite observation systems in wave models (Mastenbroek, 1994; Young and Glowacki, 1996... Sea wave model. Journal of Geophysical Research 10, 5829–5849. Young, I.R., 1994. Global ocean wave statistics obtained from satellite observations. Applied Ocean Research 16, 235-248. Young, I.R., Glowacki, T.J., 1996. Assimilation of altimeter...

  14. Waves in the seas

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J

    , steep nonsymmetric cnoidal waves, solitons and random waves. They have different properties too. Any wave form has a wave period (T), wave height (H) and speed (C) which depends on T. Still another type of waves are breaking waves near a coast...

  15. Coastal Amplification Laws for the French Tsunami Warning Center: Numerical Modeling and Fast Estimate of Tsunami Wave Heights Along the French Riviera

    Science.gov (United States)

    Gailler, A.; Hébert, H.; Schindelé, F.; Reymond, D.

    2018-04-01

    Tsunami modeling tools in the French tsunami Warning Center operational context provide rapidly derived warning levels with a dimensionless variable at basin scale. A new forecast method based on coastal amplification laws has been tested to estimate the tsunami onshore height, with a focus on the French Riviera test-site (Nice area). This fast prediction tool provides a coastal tsunami height distribution, calculated from the numerical simulation of the deep ocean tsunami amplitude and using a transfer function derived from the Green's law. Due to a lack of tsunami observations in the western Mediterranean basin, coastal amplification parameters are here defined regarding high resolution nested grids simulations. The preliminary results for the Nice test site on the basis of nine historical and synthetic sources show a good agreement with the time-consuming high resolution modeling: the linear approximation is obtained within 1 min in general and provides estimates within a factor of two in amplitude, although the resonance effects in harbors and bays are not reproduced. In Nice harbor especially, variation in tsunami amplitude is something that cannot be really assessed because of the magnitude range and maximum energy azimuth of possible events to account for. However, this method is well suited for a fast first estimate of the coastal tsunami threat forecast.

  16. Wave Dragon Wave Energy Converters Used as Coastal Protection

    DEFF Research Database (Denmark)

    Nørgaard, Jørgen Harck; Andersen, Thomas Lykke; Kofoed, Jens Peter

    2011-01-01

    This paper deals with wave energy converters used to reduce the wave height along shorelines. For this study the Wave Dragon wave energy converter is chosen. The wave height reduction from a single device has been evaluated from physical model tests in scale 1:51.8 of the 260 x 150 m, 24 kW/m model...... Spain, to evaluate the potential for reducing wave heights close the shore by means of Wave Dragons....

  17. Wave

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo

    2008-01-01

    Estimates for the amount of potential wave energy in the world range from 1-10 TW. The World Energy Council estimates that a potential 2TW of energy is available from the world’s oceans, which is the equivalent of twice the world’s electricity production. Whilst the recoverable resource is many...... times smaller it remains very high. For example, whilst there is enough potential wave power off the UK to supply the electricity demands several times over, the economically recoverable resource for the UK is estimated at 25% of current demand; a lot less, but a very substantial amount nonetheless....

  18. Fear of heights and visual height intolerance.

    Science.gov (United States)

    Brandt, Thomas; Huppert, Doreen

    2014-02-01

    The aim of this review is, first, to cover the different aspects of visual height intolerance such as historical descriptions, definition of terms, phenomenology of the condition, neurophysiological control of gaze, stance and locomotion, and therapy, and, second, to identify warranted epidemiological and experimental studies. Vivid descriptions of fear of heights can be found in ancient texts from the Greek, Roman, and Chinese classics. The life-time prevalence of visual height intolerance is as high as 28% in the general population, and about 50% of those who are susceptible report an impact on quality of life. When exposed to heights, visual exploration by eye and head movements is restricted, and the velocity of locomotion is reduced. Therapy for fear of heights is dominated by the behavioral techniques applied during real or virtual reality exposure. Their efficacy might be facilitated by the administration of D-cycloserine or glucocorticoids. Visual height intolerance has a considerable impact on daily life and interpersonal interactions. It is much more frequent than fear of heights, which is defined as an environmental subtype of a specific phobia. There is certainly a continuum stretching from acrophobia to a less-pronounced visual height intolerance, to which the categorical distinction of a specific phobia does not apply.

  19. Fall from heights: does height really matter?

    Science.gov (United States)

    Alizo, G; Sciarretta, J D; Gibson, S; Muertos, K; Romano, A; Davis, J; Pepe, A

    2018-06-01

    Fall from heights is high energy injuries and constitutes a fraction of all fall-related trauma evaluations while bearing an increase in morbidity and mortality. We hypothesize that despite advancements in trauma care, the overall survivability has not improved in this subset of trauma patients. All adult trauma patients treated after sustaining a fall from heights during a 40-month period were retrospectively reviewed. Admission demographics, clinical data, fall height (ft), injury patterns, ISS, GCS, length of stay, and mortality were reviewed. 116 patients sustained a fall from heights, 90.4% accidental. A mean age of 37± 14.7 years, 86% male, and a fall height of 19 ± 10 ft were encountered. Admission GCS was 13 ± 2 with ISS 10 ± 11. Overall LOS was 6.6 ± 14.9 days and an ICU LOS of 2.8 ± 8.9 days. Falls ≥ 25 ft.(16%) had lower GCS 10.4 ± 5.8, increased ISS 22.6 ± 13.8, a fall height 37.9 ± 13.1 ft and associated increased mortality (p < 0.001). Mortality was 5.2%, a mean distance fallen of 39 ± 22 ft. and an ISS of 31.5 ±16.5. Brain injury was the leading cause of death, 50% with open skull fractures. Level of height fallen is a good predictor of overall outcome and survival. Despite advances in trauma care, death rates remain unchanged. Safety awareness and injury prevention programs are needed to reduce the risk of high-level falls.

  20. Sri Lanka, Colored Height

    Science.gov (United States)

    2005-01-01

    The topography of the island nation of Sri Lanka is well shown in this color-coded shaded relief map generated with digital elevation data from the Shuttle Radar Topography Mission (SRTM). Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations. For this special view heights below 10 meters (33 feet) above sea level have been colored red. These low coastal elevations extend 5 to 10 km (3.1 to 6.2 mi) inland on Sri Lanka and are especially vulnerable to flooding associated with storm surges, rising sea level, or, as in the aftermath of the earthquake of December 26, 2004, tsunami. These so-called tidal waves have occurred numerous times in history and can be especially destructive, but with the advent of the near-global SRTM elevation data planners can better predict which areas are in the most danger and help develop mitigation plans in the event of particular flood events. Sri Lanka is shaped like a giant teardrop falling from the southern tip of the vast Indian subcontinent. It is separated from India by the 50km (31mi) wide Palk Strait, although there is a series of stepping-stone coral islets known as Adam's Bridge that almost form a land bridge between the two countries. The island is just 350km (217mi) long and only 180km (112mi) wide at its broadest, and is about the same size as Ireland, West Virginia or Tasmania. The southern half of the island is dominated by beautiful and rugged hill country, and includes Mt Pidurutalagala, the islandaE(TM)s highest point at 2524 meters (8281 ft). The entire northern half comprises a large plain extending from the edge of the hill country to the

  1. Characteristics of monsoon waves off Uran, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Nayak, B.U.; Chandramohan, P.; Mandal, S.

    's and the spectral methods for determining various wave parameters. Monsoon wave climate was stronger with the occurrence of the highest significant wave height of 2.45 m and the corresponding maximum wave height of 3.9 m in July. Significant wave height varied from...

  2. Lucas Heights technology park

    International Nuclear Information System (INIS)

    1987-01-01

    The proposed Lucas Heights Technology Park will pound together the applied research programs of Government, tertiary and industry sectors, aiming to foster technology transfer particularly to the high-technology manufacturing industry. A description of the site is given along with an outline of the envisaged development, existing facilities and expertise. ills

  3. Wave attenuation charcteristics of tethered float system

    Digital Repository Service at National Institute of Oceanography (India)

    Vethamony, P.

    incident wave height transmitted wave height G wave number float mass number of rows of floats drag power transmitted wave power incident wave power 111 112 P. Vethamony float radius wave period time velocity and acceleration of fluid... particles, respectively wave attenuation in percentage displacement, velocity and acceleration of float, respectively amplitude of float displacement added mass damping coefficient fluid particle displacement amplitude of fluid particle displacement...

  4. Investigation of Wave Transmission from a Floating Wave Dragon Wave Energy Converter

    DEFF Research Database (Denmark)

    Nørgaard, Jørgen Harck; Andersen, Thomas Lykke

    2012-01-01

    This paper focuses on the calibration of the MIKE21BW model against the measured wave height reduction behind a 24 kW/m Wave Dragon (WD) wave energy converter. A numerical model is used to determine the wave transmission through the floating WD in varying wave conditions. The transmission obtained...

  5. APTCARE - Lucas Heights

    International Nuclear Information System (INIS)

    1986-05-01

    This plan details command co-ordination and support responses of Commonwealth and State Authorities in the event of an accident with offsite consequences at the Lucas Heights Research Laboratories. The plan has been prepared by the AAEC Local Liaison Working Party, comprising representatives of the Australian Atomic Energy Commission, NSW Police Department, NSW Board of Fire Commissioners, NSW State Emergency Services and Civil Defence Organisation, NSW Department of Health, NSW Department of Environment and Planning and Sutherland Shire Council

  6. Childhood height, adult height, and the risk of prostate cancer

    DEFF Research Database (Denmark)

    Bjerregaard, Lise Geisler; Aarestrup, Julie; Gamborg, Michael

    2016-01-01

    PURPOSE: We previously showed that childhood height is positively associated with prostate cancer risk. It is, however, unknown whether childhood height exerts its effects independently of or through adult height. We investigated whether and to what extent childhood height has a direct effect...... on the risk of prostate cancer apart from adult height. METHODS: We included 5,871 men with height measured at ages 7 and 13 years in the Copenhagen School Health Records Register who also had adult (50-65 years) height measured in the Danish Diet, Cancer and Health study. Prostate cancer status was obtained...... through linkage to the Danish Cancer Registry. Direct and total effects of childhood height on prostate cancer risk were estimated from Cox regressions. RESULTS: From 1996 to 2012, 429 prostate cancers occurred. Child and adult heights were positively and significantly associated with prostate cancer risk...

  7. Accuracy of recumbent height measurement.

    Science.gov (United States)

    Gray, D S; Crider, J B; Kelley, C; Dickinson, L C

    1985-01-01

    Since many patients requiring specialized nutritional support are bedridden, measurement of height for purposes of nutritional assessment or prescription must often be done with the patient in bed. This study examined the accuracy of measuring body height in bed in the supine position. Two measurements were performed on 108 ambulatory inpatients: (1) standing height using a standard height-weight scale, and (2) bed height using a flexible tape. Patients were divided into four groups based on which of two researchers performed each of the two measurements. Each patient was also weighed and self-reported height, weight, sex, and age were recorded. Bed height was significantly longer than standing height by 3.68 cm, but the two measurements were equally precise. It was believed, however, that this 2% difference was probably not clinically significant in most circumstances. Bed height correlated highly with standing height (r = 0.95), and the regression equation was standing height = 13.82 +/- 0.09 bed height. Patients overestimated their heights. Heights recorded by nurses were more accurate when patients were measured than when asked about their heights, but the patients were more often asked than measured.

  8. Significant Wave Heights, Periods, and Directions, and Air and Sea Temperature Data from a Directional Waverider Buoy off Diamond Head, Oahu during March-April 2000 (NODC Accession 0000475)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A directional waverider buoy located about one nautical mile south of Diamond Head, Oahu, provided an approximately 10-day time series of wave characteristics and...

  9. Memory for target height is scaled to observer height.

    Science.gov (United States)

    Twedt, Elyssa; Crawford, L Elizabeth; Proffitt, Dennis R

    2012-04-01

    According to the embodied approach to visual perception, individuals scale the environment to their bodies. This approach highlights the central role of the body for immediate, situated action. The present experiments addressed whether body scaling--specifically, eye-height scaling--occurs in memory when action is not immediate. Participants viewed standard targets that were either the same height as, taller than, or shorter than themselves. Participants then viewed a comparison target and judged whether the comparison was taller or shorter than the standard target. Participants were most accurate when the standard target height matched their own heights, taking into account postural changes. Participants were biased to underestimate standard target height, in general, and to push standard target height away from their own heights. These results are consistent with the literature on eye-height scaling in visual perception and suggest that body scaling is not only a useful metric for perception and action, but is also preserved in memory.

  10. Concordant preferences for actual height and facial cues to height

    OpenAIRE

    Re, Daniel Edward; Perrett, David I.

    2012-01-01

    Physical height has a well-documented effect on human mate preferences. In general, both sexes prefer opposite-sex romantic relationships in which the man is taller than the woman, while individual preferences for height are affected by a person’s own height. Research in human mate choice has demonstrated that attraction to facial characteristics, such as facial adiposity, may reflect references for body characteristics. Here, we tested preferences for facial cues to height. In general, incre...

  11. Sexual Orientation, Objective Height, and Self-Reported Height.

    Science.gov (United States)

    Skorska, Malvina N; Bogaert, Anthony F

    2017-01-01

    Studies that have used mostly self-reported height have found that androphilic men and women are shorter than gynephilic men and women, respectively. This study examined whether an objective height difference exists or whether a psychosocial account (e.g., distortion of self-reports) may explain these putative height differences. A total of 863 participants, recruited at a Canadian university, the surrounding region, and through lesbian, gay, bisexual, and transgender (LGBT) events across Canada, self-reported their height and had their height measured. Androphilic men were shorter, on average, than gynephilic men. There was no objective height difference between gynephilic, ambiphilic, and androphilic women. Self-reported height, statistically controlling for objective height, was not related to sexual orientation. These findings are the first to show an objective height difference between androphilic and gynephilic men. Also, the findings suggest that previous studies using self-reported height found part of a true objective height difference between androphilic and gynephilic men. These findings have implications for existing biological theories of men's sexual orientation development.

  12. Height premium for job performance.

    Science.gov (United States)

    Kim, Tae Hyun; Han, Euna

    2017-08-01

    This study assessed the relationship of height with wages, using the 1998 and 2012 Korean Labor and Income Panel Study data. The key independent variable was height measured in centimeters, which was included as a series of dummy indicators of height per 5cm span (wages to assess the heterogeneity in the height-wage relationship, across the conditional distribution of monthly wages. We found a non-linear relationship of height with monthly wages. For men, the magnitude of the height wage premium was overall larger at the upper quantile of the conditional distribution of log monthly wages than at the median to low quantile, particularly in professional and semi-professional occupations. The height-wage premium was also larger at the 90th quantile for self-employed women and salaried men. Our findings add a global dimension to the existing evidence on height-wage premium, demonstrating non-linearity in the association between height and wages and heterogeneous changes in the dispersion and direction of the association between height and wages, by wage level. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Numerical investigation of freak waves

    Science.gov (United States)

    Chalikov, D.

    2009-04-01

    Paper describes the results of more than 4,000 long-term (up to thousands of peak-wave periods) numerical simulations of nonlinear gravity surface waves performed for investigation of properties and estimation of statistics of extreme (‘freak') waves. The method of solution of 2-D potential wave's equations based on conformal mapping is applied to the simulation of wave behavior assigned by different initial conditions, defined by JONSWAP and Pierson-Moskowitz spectra. It is shown that nonlinear wave evolution sometimes results in appearance of very big waves. The shape of freak waves varies within a wide range: some of them are sharp-crested, others are asymmetric, with a strong forward inclination. Some of them can be very big, but not steep enough to create dangerous conditions for vessels (but not for fixed objects). Initial generation of extreme waves can occur merely as a result of group effects, but in some cases the largest wave suddenly starts to grow. The growth is followed sometimes by strong concentration of wave energy around a peak vertical. It is taking place in the course of a few peak wave periods. The process starts with an individual wave in a physical space without significant exchange of energy with surrounding waves. Sometimes, a crest-to-trough wave height can be as large as nearly three significant wave heights. On the average, only one third of all freak waves come to breaking, creating extreme conditions, however, if a wave height approaches the value of three significant wave heights, all of the freak waves break. The most surprising result was discovery that probability of non-dimensional freak waves (normalized by significant wave height) is actually independent of density of wave energy. It does not mean that statistics of extreme waves does not depend on wave energy. It just proves that normalization of wave heights by significant wave height is so effective, that statistics of non-dimensional extreme waves tends to be independent

  14. Generation and Limiters of Rogue Waves

    Science.gov (United States)

    2014-06-01

    Jacobs, 7320 Ruth H. Preller, 7300 1231 1008.3 E. R. Franchi , 7000 Erick Rogers, 7322 1. REFERENCES AND ENCLOSURES 2. TYPE OF PUBLICATION OR...wave heights do not grow unlimited. With massive amount of global wave observations available nowadays, wave heights much in excess of 30m have never

  15. Wind speed, wind direction, air temperature, wave energy spectra, significant wave height, dominant wave period and direction, peak wave period and direction, currents, temperature, conductivity, pressure, sigma-theta, river level, sonar readings, and backscatter data collected at Myrtle Beach in the North Atlantic Ocean from instruments deployed on MOORINGS using platforms NOAA Ship NANCY FOSTER and RV DAN MOORE from 2003-10-01 to 2004-05-01 (NODC Accession 0066109)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These bottom current, wave and associated observations were collected as part of a larger study to understand the physical processes that control the transport of...

  16. More practical critical height sampling.

    Science.gov (United States)

    Thomas B. Lynch; Jeffrey H. Gove

    2015-01-01

    Critical Height Sampling (CHS) (Kitamura 1964) can be used to predict cubic volumes per acre without using volume tables or equations. The critical height is defined as the height at which the tree stem appears to be in borderline condition using the point-sampling angle gauge (e.g. prism). An estimate of cubic volume per acre can be obtained from multiplication of the...

  17. Height-Deterministic Pushdown Automata

    DEFF Research Database (Denmark)

    Nowotka, Dirk; Srba, Jiri

    2007-01-01

    We define the notion of height-deterministic pushdown automata, a model where for any given input string the stack heights during any (nondeterministic) computation on the input are a priori fixed. Different subclasses of height-deterministic pushdown automata, strictly containing the class...... of regular languages and still closed under boolean language operations, are considered. Several of such language classes have been described in the literature. Here, we suggest a natural and intuitive model that subsumes all the formalisms proposed so far by employing height-deterministic pushdown automata...

  18. Unified height systems after GOCE

    Science.gov (United States)

    Rummel, Reiner; Gruber, Thomas; Sideris, Michael; Rangelova, Elena; Woodworth, Phil; Hughes, Chris; Ihde, Johannes; Liebsch, Gunter; Rülke, Axel; Gerlach, Christian; Haagmans, Roger

    2015-04-01

    The objectives of global height unification are twofold, (1) the realization of accurate geopotential numbers C together with their standard deviation σ(C) at a selected set of stations (datum points of national height systems, geodetic fundamental stations (IERS), primary tide gauges (PSMSL) and primary reference clocks (IERS)) and (2) the determination of height off-sets between all existing regional/national height systems and one global height reference. In the future the primary method of height determination will be GPS-levelling with very stringent requirements concerning the consistency of the positioning and the gravity potential difference part. Consistency is required in terms of the applied standards (ITRF, zero tide system, geodetic reference system). Geopotential differences will be based on a next generation geopotential model combining GOCE and GRACE and a best possible collection of global terrestrial and altimetric gravity and topographic data. Ultimately, the envisaged accuracy of height unification is about 10 cm2/s2 (or 1cm). At the moment, in well surveyed regions, an accuracy of about 40 to 60 cm2/s2 (or 4 to 6cm) is attainable. Objective One can be realized by straight forward computation of geopotential numbers C, i.e. geopotential differences relative to an adopted height reference. No adjustment is required for this. Objective Two, the unification of existing height systems is achieved by employing a least-squares adjustment based on the GBVP-approach. In order to attain a non-singular solution, this requires for each included datum zone at least one geo-referenced station per zone, i.e. its ellipsoidal height h and, in addition, the corresponding physical height H (geopotential number, normal height, orthometric height, etc.). Changes in geopotential numbers of consecutive realizations reflect (1) temporal changes of station heights, (2) improvements or changes of the applied geopotential (or geoid) model and (3) improvements of the

  19. Agreement between measured height, and height predicted from ...

    African Journals Online (AJOL)

    lower limb measurements, such as knee height, as well as upper limb measures ... had with bone injuries/fractures affecting height or ulna length; and n = 1 had a ... and heels, buttocks and upper back in contact with the vertical surface of the .... found striking similarity in linear growth of infants to five-year- olds among all ...

  20. Height and Tilt Geometric Texture

    DEFF Research Database (Denmark)

    Andersen, Vedrana; Desbrun, Mathieu; Bærentzen, Jakob Andreas

    2009-01-01

    compromise between functionality and simplicity: it can efficiently handle and process geometric texture too complex to be represented as a height field, without having recourse to full blown mesh editing algorithms. The height-and-tilt representation proposed here is fully intrinsic to the mesh, making...

  1. Fluctuations in Schottky barrier heights

    International Nuclear Information System (INIS)

    Mahan, G.D.

    1984-01-01

    A double Schottky barrier is often formed at the grain boundary in polycrystalline semiconductors. The barrier height is shown to fluctuate in value due to the random nature of the impurity positions. The magnitude of the fluctuations is 0.1 eV, and the fluctuations cause the barrier height measured by capacitance to differ from the one measured by electrical conductivity

  2. Real time wave measurements and wave hindcasting in deep waters

    Digital Repository Service at National Institute of Oceanography (India)

    Anand, N.M.; Mandal, S.; SanilKumar, V.; Nayak, B.U.

    Deep water waves off Karwar (lat. 14~'45.1'N, long. 73~'34.8'E) at 75 m water depth pertaining to peak monsoon period have been measured using a Datawell waverider buoy. Measured wave data show that the significant wave height (Hs) predominantly...

  3. Projected impact of climate change on waves at Mumbai High

    Digital Repository Service at National Institute of Oceanography (India)

    Pentapatim, S.; Deo, M.C.; Kerkar, J.; Vethamony, P.

    .5), a numerical wave model of the past and future wave conditions was simulated over a 40-year period. A statistical analysis of both past and projected datasets obtained significant wave heights with a 100-year return. The comparison of wave heights...

  4. Wave attenuation in the Agulhas current

    CSIR Research Space (South Africa)

    Grundlingh, M

    1995-07-01

    Full Text Available The enlargement of surface wave height in the Agulhas Current, caused by waves propagating in the opposite direction to the current, is well known for its danger to large vessels traversing the Cape route. Occurrence characteristics...

  5. Mexico Geoid Heights (MEXICO97)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' geoid height grid for Mexico, and North-Central America, is the MEXICO97 geoid model. The computation used about one million terrestrial and marine gravity...

  6. Alaska Geoid Heights (GEOID96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' x 4' geoid height grid for Alaska is distributed as a GEOID96 model. The computation used 1.1 million terrestrial and marine gravity data held in the...

  7. Wave refraction and prediction of breaker parameters along the Kerala Coast, India

    Digital Repository Service at National Institute of Oceanography (India)

    Sajeev, R.; Chandramohan, P.; SanilKumar, V.

    significantly from place to place due to wave refraction and shoaling. The covergence and divergence of wave energy induce non-uniform distribution of wave heights during the monsoon period. Ezhimala promontory causes waves to refract considerably along...

  8. Standardizing Scale Height Computation of Maven Ngims Neutral Data and Variations Between Exobase and Homeopause Scale Heights

    Science.gov (United States)

    Elrod, M. K.; Slipski, M.; Curry, S.; Williamson, H. N.; Benna, M.; Mahaffy, P. R.

    2017-12-01

    a jog or kink in the atmosphere in several atmospheric profiles slightly above the exobase indicating a change in the scale height between the super and supra- exobase temperatures. Waves are more prevalent on the night side and terminator sides making scale height fits more difficult. As a result we have added confidence level and error to the scale height fits to the lvl 3 product for reference.

  9. Mixing height determination from the momentum balance of the neutral or stable PBL

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, J.C. [Risoe National Lab., Roskilde (Denmark)

    1997-10-01

    The mixing height is defined by the top of the layer of turbulent mixing. This height is equal to the height H of turbulent vertical momentum transport (fiction) in neutral or stable stratification. In very stable cases, the wave induced momentum transport must be excluded if the waves do not have mixing effects (e.g. break) within the frictional layer. Thus the conditions provided by the momentum balance determine the mixing height in most cases of mechanical turbulence. Mixing is a time dependent process and depends also on the height of release of substance to be mixed. It depends on the specific form of the exchange coefficient function whether the mixing time for the mixed layer is finite of infinite. If this time is infinite, an additional mixing time criterion for a substance released close to the ground must be applied for the determination of the corresponding mixing height. (au)

  10. Height and Breast Cancer Risk

    DEFF Research Database (Denmark)

    Zhang, Ben; Shu, Xiao-Ou; Delahanty, Ryan J

    2015-01-01

    BACKGROUND: Epidemiological studies have linked adult height with breast cancer risk in women. However, the magnitude of the association, particularly by subtypes of breast cancer, has not been established. Furthermore, the mechanisms of the association remain unclear. METHODS: We performed a meta......-analysis to investigate associations between height and breast cancer risk using data from 159 prospective cohorts totaling 5216302 women, including 113178 events. In a consortium with individual-level data from 46325 case patients and 42482 control patients, we conducted a Mendelian randomization analysis using...... a genetic score that comprised 168 height-associated variants as an instrument. This association was further evaluated in a second consortium using summary statistics data from 16003 case patients and 41335 control patients. RESULTS: The pooled relative risk of breast cancer was 1.17 (95% confidence...

  11. Experimental Study on the WavePiston Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Angelelli, E.

    This report presents the results of an experimental study of the power performance of the WavePiston wave energy converter. It focuses mainly on evaluating the power generating capabilities of the device and the effect of the following issues: Scaling ratios PTO loading Wave height and wave period...... dependency Oblique incoming waves Distance between plates During the study, the model supplied by the client, WavePiston, has been rigorously tested as all the anticipated tests have been done thoroughly and during all tests, good quality data has been obtained from all the sensors....

  12. Measuring the height-to-height correlation function of corrugation in suspended graphene

    International Nuclear Information System (INIS)

    Kirilenko, D.A.; Brunkov, P.N.

    2016-01-01

    Nanocorrugation of 2D crystals is an important phenomenon since it affects their electronic and mechanical properties. The corrugation may have various sources; one of them is flexural phonons that, in particular, are responsible for the thermal conductivity of graphene. A study of corrugation of just the suspended graphene can reveal much of valuable information on the physics of this complicated phenomenon. At the same time, the suspended crystal nanorelief can hardly be measured directly because of high flexibility of the 2D crystal. Moreover, the relief portion related to rapid out-of-plane oscillations (flexural phonons) is also inaccessible by such measurements. Here we present a technique for measuring the Fourier components of the height–height correlation function H(q) of suspended graphene which includes the effect of flexural phonons. The technique is based on the analysis of electron diffraction patterns. The H(q) is measured in the range of wavevectors q≈0.4–4.5 nm"−"1. At the upper limit of this range H(q) does follow the T/κq"4 law. So, we measured the value of suspended graphene bending rigidity κ=1.2±0.4 eV at ambient temperature T≈300 K. At intermediate wave vectors, H(q) follows a slightly weaker exponent than theoretically predicted q"−"3"."1"5 but is closer to the results of the molecular dynamics simulation. At low wave vectors, the dependence becomes even weaker, which may be a sign of influence of charge carriers on the dynamics of undulations longer than 10 nm. The technique presented can be used for studying physics of flexural phonons in other 2D materials. - Highlights: • A technique for measuring free-standing 2D crystal corrugation is proposed. • The height-to-height correlation function of the suspended graphene corrugation is measured. • Various parameters of the intrinsic graphene properties are experimentally determined.

  13. Estimation of wind speed and wave height during cyclones

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; Mandal, S.; AshokKumar, K.

    , the isobaric charts were collected at three hourly intervals from the India Meteorological Department. The storm variables such as central pressure, radius of maximum wind, speed of forward motion and direction of storm movement were extracted and the method...

  14. Wave attenuation over the Great Barrier Reef matrix

    NARCIS (Netherlands)

    Gallop, S.; Young, I.; Ranasinghe, Ranasinghe W M R J B; Durrant, T.; Haigh, I.; Mynett, Arthur

    2015-01-01

    This is the first large-scale study of the influence of an offshore reef matrix on wave transmission. The focus was on the Great Barrier Reef (GBR), Australia, utilizing a 16 yr-record of wave height, from seven satellite altimeters. Within the GBR matrix, wave height is not strongly dependent on

  15. Heritability of adult body height

    DEFF Research Database (Denmark)

    Silventoinen, Karri; Sammalisto, Sampo; Perola, Markus

    2003-01-01

    /unique environment (AE) model. Among women the heritability estimates were generally lower than among men with greater variation between countries, ranging from 0.68 to 0.84 when an additive genes/shared environment/unique environment (ACE) model was used. In four populations where an AE model fit equally well...... countries; body height was least in Italy (177 cm in men and 163 cm in women) and greatest in the Netherlands (184 cm and 171 cm, respectively). In men there was no corresponding variation in heritability of body height, heritability estimates ranging from 0.87 to 0.93 in populations under an additive genes...... or better, heritability ranged from 0.89 to 0.93. This difference between the sexes was mainly due to the effect of the shared environmental component of variance, which appears to be more important among women than among men in our study populations. Our results indicate that, in general, there are only...

  16. Analysis of Flame Extinguishment and Height in Low Frequency Acoustically Excited Methane Jet Diffusion Flame

    Science.gov (United States)

    Zong, Ruowen; Kang, Ruxue; Liu, Chen; Zhang, Zhiyang; Zhi, Youran

    2018-01-01

    The exploration of microgravity conditions in space is increasing and existing fire extinguishing technology is often inadequate for fire safety in this special environment. As a result, improving the efficiency of portable extinguishers is of growing importance. In this work, a visual study of the effects on methane jet diffusion flames by low frequency sound waves is conducted to assess the extinguishing ability of sound waves. With a small-scale sound wave extinguishing bench, the extinguishing ability of certain frequencies of sound waves are identified, and the response of the flame height is observed and analyzed. Results show that the flame structure changes with disturbance due to low frequency sound waves of 60-100 Hz, and quenches at effective frequencies in the range of 60-90 Hz. In this range, 60 Hz is considered to be the quick extinguishing frequency, while 70-90 Hz is the stable extinguishing frequency range. For a fixed frequency, the flame height decreases with sound pressure level (SPL). The flame height exhibits the greatest sensitivity to the 60 Hz acoustic waves, and the least to the 100 Hz acoustic waves. The flame height decreases almost identically with disturbance by 70-90 Hz acoustic waves.

  17. Physical Model Study of Wave Action in New Thomsen Harbor, Sitka, Alaska

    Science.gov (United States)

    2008-02-01

    approached from the southwest. DISCLAIMER: The contents of this report are not to be used for advertising , publication, or promotional purposes...Wave height and period for irregular wave conditions refer to Hm0 and Tp, respectively. For mono- chromatic waves, wave height is the actual height...sec, respectively. Plotted along with the Group 12 results are corresponding tests from Group 13 that used mono- chromatic waves. Looking only at

  18. CFD study of the overtopping discharge of the Wave Dragon wave energy converter

    DEFF Research Database (Denmark)

    Eskilsson, K.; Palm, J.; Kofoed, Jens Peter

    2015-01-01

    incompressible Euler/Navier-Stokes solver in the OpenFOAM® framework. We present simulations of: (i) a complete sea state for different crest heights, and (ii) regular waves for different wave conditions and crest heights. The simulations compare reasonably well with the experimental data, albeit the irregular...

  19. TAPCHAN Wave Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    1983-10-01

    The Tapered Channel Wave Power Plant (TAPCHAN) is based on a new method for wave energy conversion. The principle of operation can be explained by dividing the system into the following four sub-systems: Firstly, a collector which is designed to concentrate the water energy and optimize collection efficiency for a range of frequencies and directions. Secondly, the energy converter, in which the energy of the collected waves is transformed into potential energy in an on-shore water reservoir. This is the unique part of the power plant. It consists of a gradually narrowing channel with wall heights equal to the filling level of the reservoir (typical heights 3-7 m). The waves enter the wide end of the channel and as they propagate down the narrowing channel, the wave height is amplified until the wavecrests spill over the walls. Thirdly, a reservoir which provides a stable water supply for the turbines. Finally, the hydroelectric power plant, where well established techniques are used for the generation of electric power. The water turbine driving the electric generator is of a low head type, such as a Kaplan or a tubular turbine. It must be designed for salt water operation and should have good regulation capabilities. Power plants based on the principle described, are now offered on a commercial basis.

  20. Final height in survivors of childhood cancer compared with Height Standard Deviation Scores at diagnosis

    NARCIS (Netherlands)

    Knijnenburg, S. L.; Raemaekers, S.; van den Berg, H.; van Dijk, I. W. E. M.; Lieverst, J. A.; van der Pal, H. J.; Jaspers, M. W. M.; Caron, H. N.; Kremer, L. C.; van Santen, H. M.

    2013-01-01

    Our study aimed to evaluate final height in a cohort of Dutch childhood cancer survivors (CCS) and assess possible determinants of final height, including height at diagnosis. We calculated standard deviation scores (SDS) for height at initial cancer diagnosis and height in adulthood in a cohort of

  1. Rogue waves in shallow water

    Science.gov (United States)

    Soomere, T.

    2010-07-01

    Most of the processes resulting in the formation of unexpectedly high surface waves in deep water (such as dispersive and geometrical focusing, interactions with currents and internal waves, reflection from caustic areas, etc.) are active also in shallow areas. Only the mechanism of modulational instability is not active in finite depth conditions. Instead, wave amplification along certain coastal profiles and the drastic dependence of the run-up height on the incident wave shape may substantially contribute to the formation of rogue waves in the nearshore. A unique source of long-living rogue waves (that has no analogues in the deep ocean) is the nonlinear interaction of obliquely propagating solitary shallow-water waves and an equivalent mechanism of Mach reflection of waves from the coast. The characteristic features of these processes are (i) extreme amplification of the steepness of the wave fronts, (ii) change in the orientation of the largest wave crests compared with that of the counterparts and (iii) rapid displacement of the location of the extreme wave humps along the crests of the interacting waves. The presence of coasts raises a number of related questions such as the possibility of conversion of rogue waves into sneaker waves with extremely high run-up. Also, the reaction of bottom sediments and the entire coastal zone to the rogue waves may be drastic.

  2. Maternal Height and Child Growth Patterns

    OpenAIRE

    Addo, O. Yaw; Stein, Aryeh D.; Fall, Caroline H.; Gigante, Denise P.; Guntupalli, Aravinda M.; Horta, Bernardo L.; Kuzawa, Christopher W.; Lee, Nanette; Norris, Shane A.; Prabhakaran, Poornima; Richter, Linda M.; Sachdev, Harshpal S.; Martorell, Reynaldo

    2013-01-01

    OBJECTIVE:\\ud To examine associations between maternal height and child growth during 4 developmental periods: intrauterine, birth to age 2 years, age 2 years to mid-childhood (MC), and MC to adulthood.\\ud \\ud STUDY DESIGN:\\ud Pooled analysis of maternal height and offspring growth using 7630 mother-child pairs from 5 birth cohorts (Brazil, Guatemala, India, the Philippines, and South Africa). We used conditional height measures that control for collinearity in height across periods. We estim...

  3. Incident wave, infragravity wave, and non-linear low-frequency bore evolution across fringing coral reefs

    Science.gov (United States)

    Storlazzi, C. D.; Griffioen, D.; Cheriton, O. M.

    2016-12-01

    Coral reefs have been shown to significantly attenuate incident wave energy and thus provide protection for 100s of millions of people globally. To better constrain wave dynamics and wave-driven water levels over fringing coral reefs, a 4-month deployment of wave and tide gauges was conducted across two shore-normal transects on Roi-Namur Island and two transects on Kwajalein Island in the Republic of the Marshall Islands. At all locations, although incident wave (periods 250 s) heights on the outer reef flat just inshore of the zone of wave breaking, the infragravity wave heights generally equaled the incident wave heights by the middle of the reef flat and exceeded the incident wave heights on the inner reef flat by the shoreline. The infragravity waves generally were asymmetric, positively skewed, bore-like forms with incident-band waves riding the infragravity wave crest at the head of the bore; these wave packets have similar structure to high-frequency internal waves on an internal wave bore. Bore height was shown to scale with water depth, offshore wave height, and offshore wave period. For a given tidal elevation, with increasing offshore wave heights, such bores occurred more frequently on the middle reef flat, whereas they occurred less frequently on the inner reef flat. Skewed, asymmetric waves are known to drive large gradients in velocity and shear stress that can transport material onshore. Thus, a better understanding of these low-frequency, energetic bores on reef flats is critical to forecasting how coral reef-lined coasts may respond to sea-level rise and climate change.

  4. Band gaps and localization of surface water waves over large-scale sand waves with random fluctuations

    Science.gov (United States)

    Zhang, Yu; Li, Yan; Shao, Hao; Zhong, Yaozhao; Zhang, Sai; Zhao, Zongxi

    2012-06-01

    Band structure and wave localization are investigated for sea surface water waves over large-scale sand wave topography. Sand wave height, sand wave width, water depth, and water width between adjacent sand waves have significant impact on band gaps. Random fluctuations of sand wave height, sand wave width, and water depth induce water wave localization. However, random water width produces a perfect transmission tunnel of water waves at a certain frequency so that localization does not occur no matter how large a disorder level is applied. Together with theoretical results, the field experimental observations in the Taiwan Bank suggest band gap and wave localization as the physical mechanism of sea surface water wave propagating over natural large-scale sand waves.

  5. Characteristics of waves off Goa, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; AshokKumar, K.; Anand, N.M.

    Directional wave measurements were carried out using Datawell directional waverider buoy off Goa along west coast of India during the south west monsoon period in 1996 and the results are presented. Theoretical joint distribution of wave height...

  6. The taking of Lucas Heights

    International Nuclear Information System (INIS)

    Sandilands, B.

    1993-01-01

    Plans for a new research reactor at Lucas Heights have sparked a 'civil war' in New South Wales. The author considers the arguments. The leading antagonists are the local government body - The Sutherland Shire Council, Greenpeace, and the Sutherland Shire Environment Centre. Many of the economic benefits claimed for the existing and proposed replacement reactor have been tagged with question marks. However, ANSTO is confident of refuting claims that the money could be better spent on alternative methods of producing medical isotopes and neutron streams for industry or research, such as particle accelerators. If ANSTO's critics have their way, non-reactor-dependent work like the laser enrichment project could continue without the alleged hazards of sustained nuclear fission. If ANSTO wins the day, a far more efficient reactor will be built which is capable of keeping pace with the emerging nuclear industries of Asia. ills

  7. Modelling of wave propagation over a submerged sand bar using SWASH

    Digital Repository Service at National Institute of Oceanography (India)

    Jishad, M.; Vu, T.T.T.; JayaKumar, S.

    cases The wave heights and wave induced velocities obtained from the model and the laboratory experimental resultsare compared The model without the morphology feedback provided good correlation with the measurements for case of low wave energy, whereas...

  8. Genetically Determined Height and Coronary Artery Disease

    NARCIS (Netherlands)

    Nelson, Christopher P.; Hamby, Stephen E.; Saleheen, Danish; Hopewell, Jenna C.; Zeng, Lingyao; Assimes, Themistocles L.; Kanoni, Stavroula; Willenborg, Christina; Burgess, Stephen; Amouyel, Phillipe; Anand, Sonia; Blankenberg, Stefan; Boehm, Bernhard O.; Clarke, Robert J.; Collins, Rory; Dedoussis, George; Farrall, Martin; Franks, Paul W.; Groop, Leif; Hall, Alistair S.; Hamsten, Anders; Hengstenberg, Christian; Hovingh, G. Kees; Ingelsson, Erik; Kathiresan, Sekar; Kee, Frank; König, Inke R.; Kooner, Jaspal; Lehtimäki, Terho; März, Winifred; McPherson, Ruth; Metspalu, Andres; Nieminen, Markku S.; O'Donnell, Christopher J.; Palmer, Colin N. A.; Peters, Annette; Perola, Markus; Reilly, Muredach P.; Ripatti, Samuli; Roberts, Robert; Salomaa, Veikko; Shah, Svati H.; Schreiber, Stefan; Siegbahn, Agneta; Thorsteinsdottir, Unnur; Veronesi, Giovani; Wareham, Nicholas; Willer, Cristen J.; Zalloua, Pierre A.; Erdmann, Jeanette

    2015-01-01

    BACKGROUND The nature and underlying mechanisms of an inverse association between adult height and the risk of coronary artery disease (CAD) are unclear. METHODS We used a genetic approach to investigate the association between height and CAD, using 180 height-associated genetic variants. We tested

  9. Risk analysis of breakwater caisson under wave attack using load surface approximation

    Science.gov (United States)

    Kim, Dong Hyawn

    2014-12-01

    A new load surface based approach to the reliability analysis of caisson-type breakwater is proposed. Uncertainties of the horizontal and vertical wave loads acting on breakwater are considered by using the so-called load surfaces, which can be estimated as functions of wave height, water level, and so on. Then, the first-order reliability method (FORM) can be applied to determine the probability of failure under the wave action. In this way, the reliability analysis of breakwaters with uncertainties both in wave height and in water level is possible. Moreover, the uncertainty in wave breaking can be taken into account by considering a random variable for wave height ratio which relates the significant wave height to the maximum wave height. The proposed approach is applied numerically to the reliability analysis of caisson breakwater under wave attack that may undergo partial or full wave breaking.

  10. Experimental Studies on Wave Interactions of Partially Perforated Wall under Obliquely Incident Waves

    Directory of Open Access Journals (Sweden)

    Jong-In Lee

    2014-01-01

    Full Text Available This study presents wave height distribution in terms of stem wave evolution phenomena on partially perforated wall structures through three-dimensional laboratory experiments. The plain and partially perforated walls were tested to understand their effects on the stem wave evolution under the monochromatic and random wave cases with the various wave conditions, incident angle (from 10 to 40 degrees, and configurations of front and side walls. The partially perforated wall reduced the relative wave heights more effectively compared to the plain wall structure. Partially perforated walls with side walls showed a better performance in terms of wave height reduction compared to the structure without the side wall. Moreover, the relative wave heights along the wall were relatively small when the relative chamber width is large, within the range of the chamber width in this study. The wave spectra showed a frequency dependency of the wave energy dissipation. In most cases, the existence of side wall is a more important factor than the porosity of the front wall in terms of the wave height reduction even if the partially perforated wall was still effective compared to the plain wall.

  11. Wave kinematics and response of slender offshore structures. Vol 4: Wave kinematics

    Energy Technology Data Exchange (ETDEWEB)

    Riber, H.J.

    1999-08-01

    The kinematics of large surface waves has been measured by means of sonar's placed on the sea floor at the Tyra field. Measurements from the most severe storm are analysed and extreme wave velocity profiles are compared to Stoke wave velocity profiles. Statistical distributions of crest velocity and wave celerity are presented. The analysis shows how the deviation from the Stokes prediction varies with wave heights and steepness. Analyses of the directional wave field leads to the conclusion that the extreme waves are three-dimensional. It is shown that the peculiar kinematics of extreme waves is of great relevance to the design of jacket type structures. (au)

  12. Statistical Analysis of Wave Climate Data Using Mixed Distributions and Extreme Wave Prediction

    Directory of Open Access Journals (Sweden)

    Wei Li

    2016-05-01

    Full Text Available The investigation of various aspects of the wave climate at a wave energy test site is essential for the development of reliable and efficient wave energy conversion technology. This paper presents studies of the wave climate based on nine years of wave observations from the 2005–2013 period measured with a wave measurement buoy at the Lysekil wave energy test site located off the west coast of Sweden. A detailed analysis of the wave statistics is investigated to reveal the characteristics of the wave climate at this specific test site. The long-term extreme waves are estimated from applying the Peak over Threshold (POT method on the measured wave data. The significant wave height and the maximum wave height at the test site for different return periods are also compared. In this study, a new approach using a mixed-distribution model is proposed to describe the long-term behavior of the significant wave height and it shows an impressive goodness of fit to wave data from the test site. The mixed-distribution model is also applied to measured wave data from four other sites and it provides an illustration of the general applicability of the proposed model. The methodologies used in this paper can be applied to general wave climate analysis of wave energy test sites to estimate extreme waves for the survivability assessment of wave energy converters and characterize the long wave climate to forecast the wave energy resource of the test sites and the energy production of the wave energy converters.

  13. In defense of the classical height system

    Science.gov (United States)

    Foroughi, Ismael; Vaníček, Petr; Sheng, Michael; Kingdon, Robert William; Santos, Marcelo C.

    2017-11-01

    In many European countries, normal heights referred to the quasi-geoid as introduced by Molodenskij in the mid-20th century are preferred to the classical height system that consists of orthometric heights and the geoid as a reference surface for these heights. The rationale for this choice is supposed to be that in the classical height system, neither the geoid, nor the orthometric height can be ever known with centimetre level accuracy because one would need to know the topographical mass density to a level that can never be achieved. The aim of this paper is to question the validity of this rationale. The common way of assessing the congruency of a local geoid model and the orthometric heights is to compare the geoid heights with the difference between orthometric heights provided by leveling and geodetic heights provided by GNSS. On the other hand, testing the congruency of a quasi-geoidal model with normal height a similar procedure is used, except that instead of orthometric heights, normal heights are employed. For the area of Auvergne, France, which is now a more or less standard choice for precise geoid or quasi-geoid testing, only the normal heights are supplied by the Institute Geographic National, the provider of the data. This is clearly the consequence of the European preference for the Molodenskij system. The quality of the height system is to be judged by the congruency of the difference of the geoid/quasi-geoid heights subtracted from the geodetic heights and orthometric/normal heights. To assess the congruency of the classical height system, the Helmert approximation of orthometric heights is typically used as the transformation between normal and Helmert's heights is easily done. However, the evaluation of the differences between Helmert's and the rigorous orthometric heights is somewhat more involved as will be seen from the review in this paper. For the area of interest, the differences between normal and Helmert's heights at the control

  14. Surf similarity and solitary wave runup

    DEFF Research Database (Denmark)

    Fuhrman, David R.; Madsen, Per A.

    2008-01-01

    The notion of surf similarity in the runup of solitary waves is revisited. We show that the surf similarity parameter for solitary waves may be effectively reduced to the beach slope divided by the offshore wave height to depth ratio. This clarifies its physical interpretation relative to a previ...... functional dependence on their respective surf similarity parameters. Important equivalencies in the runup of sinusoidal and solitary waves are thus revealed.......The notion of surf similarity in the runup of solitary waves is revisited. We show that the surf similarity parameter for solitary waves may be effectively reduced to the beach slope divided by the offshore wave height to depth ratio. This clarifies its physical interpretation relative...... to a previous parameterization, which was not given in an explicit form. Good coherency with experimental (breaking) runup data is preserved with this simpler parameter. A recasting of analytical (nonbreaking) runup expressions for sinusoidal and solitary waves additionally shows that they contain identical...

  15. Rational homoclinic solution and rogue wave solution for the ...

    Indian Academy of Sciences (India)

    –4]. Rogue waves were first observed in deep ocean [5]. A wave can be called a rogue wave when its height and steepness is much greater than the average crest, and appears from nowhere and disappears without a trace [6]. Rogue waves ...

  16. General characteristics of long waves around the South African Coast

    CSIR Research Space (South Africa)

    Rossouw, M

    2013-09-01

    Full Text Available Long-period waves are almost invisible waves due to the long wave-lengths of several hundreds of metres and heights of only decimetres. The effect of these long waves can, however, be devastating in the form of harbour basin oscillations...

  17. Sensitivity of wave energy to climate change

    OpenAIRE

    Harrison, Gareth; Wallace, Robin

    2005-01-01

    Wave energy will have a key role in meeting renewable energy targets en route to a low carbon economy. However, in common with other renewables, it may be sensitive to changes in climate resulting from rising carbon emissions. Changes in wind patterns are widely anticipated and this will ultimately alter wave regimes. Indeed, evidence indicates that wave heights have been changing over the last 40 years, although there is no proven link to global warming. Changes in the wave climate will impa...

  18. Wave energy and its possibilities in the Danish power supplies

    International Nuclear Information System (INIS)

    Traeholt Madsen, N.; Lorenzen, S.; Haunstrup Christensen, T.

    1997-06-01

    Mathematical theory of wave forces (wave height, spectrua, energy distribution and effect) is summarized. An attempt to estimate the Danish wave power potential on the basis of previous investigations og wave effect in various regions is presented. A brief review of wave energy applications and research constitutes basis for two scenarios of wave power adjustment into the 'Green society'. Power quality, environment, economics and supply reliability are estimated. (EG) 42 refs

  19. Physiological pattern of lumbar disc height

    International Nuclear Information System (INIS)

    Biggemann, M.; Frobin, W.; Brinckmann, P.

    1997-01-01

    Purpose of this study is to present a new method of quantifying objectively the height of all discs in lateral radiographs of the lumbar spine and of analysing the normal craniocaudal sequence pattern of lumbar disc heights. Methods: The new parameter is the ventrally measured disc height corrected for the dependence on the angle of lordosis by normalisation to mean angles observed in the erect posture of healthy persons. To eliminate radiographic magnification, the corrected ventral height is related to the mean depth of the cranially adjoining vertebra. In this manner lumbar disc heights were objectively measured in young, mature and healthy persons (146 males and 65 females). The craniocaudal sequence pattern was analysed by mean values from all persons and by height differences of adjoining discs in each individual lumbar spine. Results: Mean normative values demonstrated an increase in disc height between L1/L2 and L4/L5 and a constant or decreasing disc height between L4/L5 and L5/S1. However, this 'physiological sequence of disc height in the statistical mean' was observed in only 36% of normal males and 55% of normal females. Conclusion: The radiological pattern of the 'physiological sequence of lumbar disc height' leads to a relevant portion of false positive pathological results especially at L4/L5. An increase of disc height from L4/L5 to L5/S1 may be normal. The recognition of decreased disc height should be based on an abrupt change in the heights of adjoining discs and not on a deviation from a craniocaudal sequence pattern. (orig.) [de

  20. Final height in survivors of childhood cancer compared with Height Standard Deviation Scores at diagnosis.

    Science.gov (United States)

    Knijnenburg, S L; Raemaekers, S; van den Berg, H; van Dijk, I W E M; Lieverst, J A; van der Pal, H J; Jaspers, M W M; Caron, H N; Kremer, L C; van Santen, H M

    2013-04-01

    Our study aimed to evaluate final height in a cohort of Dutch childhood cancer survivors (CCS) and assess possible determinants of final height, including height at diagnosis. We calculated standard deviation scores (SDS) for height at initial cancer diagnosis and height in adulthood in a cohort of 573 CCS. Multivariable regression analyses were carried out to estimate the influence of different determinants on height SDS at follow-up. Overall, survivors had a normal height SDS at cancer diagnosis. However, at follow-up in adulthood, 8.9% had a height ≤-2 SDS. Height SDS at diagnosis was an important determinant for adult height SDS. Children treated with (higher doses of) radiotherapy showed significantly reduced final height SDS. Survivors treated with total body irradiation (TBI) and craniospinal radiation had the greatest loss in height (-1.56 and -1.37 SDS, respectively). Younger age at diagnosis contributed negatively to final height. Height at diagnosis was an important determinant for height SDS at follow-up. Survivors treated with TBI, cranial and craniospinal irradiation should be monitored periodically for adequate linear growth, to enable treatment on time if necessary. For correct interpretation of treatment-related late effects studies in CCS, pre-treatment data should always be included.

  1. Imagery and fear influence height perception.

    Science.gov (United States)

    Clerkin, Elise M; Cody, Meghan W; Stefanucci, Jeanine K; Proffitt, Dennis R; Teachman, Bethany A

    2009-04-01

    The current study tested whether height overestimation is related to height fear and influenced by images of falling. To assess perceptual biases, participants high (n=65) versus low (n=64) in height fear estimated the vertical extents of two balconies using a visual matching task. On one of the balconies, participants engaged in an imagery exercise designed to enhance the subjective sense that they were acting in a dangerous environment by picturing themselves falling. As expected, we found that individuals overestimated the balcony's height more after they imagined themselves falling, particularly if they were already afraid of heights. These findings suggest that height fear may serve as a vulnerability factor that leads to perceptual biases when triggered by a stressor (in this case, images of falling).

  2. Wave Analysis Study for the Punta Catalina Jetty, Dominican Republic

    DEFF Research Database (Denmark)

    Røge, Mads Sønderstrup; Andersen, Thomas Lykke; Burcharth, Hans Falk

    This report deals with a two-dimensional test study to identify the largest significant wave height, the maximum wave height and the largest crest level along the Punta Catalina jetty in the Dominican Republic. The scale used for the model tests was 1:50. Unless otherwise specified all values given...

  3. Investigation of the relationship between hurricane waves and extreme runup

    Science.gov (United States)

    Thompson, D. M.; Stockdon, H. F.

    2006-12-01

    In addition to storm surge, the elevation of wave-induced runup plays a significant role in forcing geomorphic change during extreme storms. Empirical formulations for extreme runup, defined as the 2% exceedence level, are dependent on some measure of significant offshore wave height. Accurate prediction of extreme runup, particularly during hurricanes when wave heights are large, depends on selecting the most appropriate measure of wave height that provides energy to the nearshore system. Using measurements from deep-water wave buoys results in an overprediction of runup elevation. Under storm forcing these large waves dissipate across the shelf through friction, whitecapping and depth-limited breaking before reaching the beach and forcing swash processes. The use of a local, shallow water wave height has been shown to provide a more accurate estimate of extreme runup elevation (Stockdon, et. al. 2006); however, a specific definition of this local wave height has yet to be defined. Using observations of nearshore waves from the U.S. Army Corps of Engineers' Field Research Facility (FRF) in Duck, NC during Hurricane Isabel, the most relevant measure of wave height for use in empirical runup parameterizations was examined. Spatial and temporal variability of the hurricane wave field, which made landfall on September 18, 2003, were modeled using SWAN. Comparisons with wave data from FRF gages and deep-water buoys operated by NOAA's National Data Buoy Center were used for model calibration. Various measures of local wave height (breaking, dissipation-based, etc.) were extracted from the model domain and used as input to the runup parameterizations. Video based observations of runup collected at the FRF during the storm were used to ground truth modeled values. Assessment of the most appropriate measure of wave height can be extended over a large area through comparisons to observations of storm- induced geomorphic change.

  4. Adult height, nutrition, and population health

    Science.gov (United States)

    Perkins, Jessica M.; Subramanian, S.V.; Davey Smith, George

    2016-01-01

    In this review, the potential causes and consequences of adult height, a measure of cumulative net nutrition, in modern populations are summarized. The mechanisms linking adult height and health are examined, with a focus on the role of potential confounders. Evidence across studies indicates that short adult height (reflecting growth retardation) in low- and middle-income countries is driven by environmental conditions, especially net nutrition during early years. Some of the associations of height with health and social outcomes potentially reflect the association between these environmental factors and such outcomes. These conditions are manifested in the substantial differences in adult height that exist between and within countries and over time. This review suggests that adult height is a useful marker of variation in cumulative net nutrition, biological deprivation, and standard of living between and within populations and should be routinely measured. Linkages between adult height and health, within and across generations, suggest that adult height may be a potential tool for monitoring health conditions and that programs focused on offspring outcomes may consider maternal height as a potentially important influence. PMID:26928678

  5. Upper atmospheric planetary-wave and gravity-wave observations

    Science.gov (United States)

    Justus, C. G.; Woodrum, A.

    1973-01-01

    Previously collected data on atmospheric pressure, density, temperature and winds between 25 and 200 km from sources including Meteorological Rocket Network data, ROBIN falling sphere data, grenade release and pitot tube data, meteor winds, chemical release winds, satellite data, and others were analyzed by a daily-difference method, and results on the magnitude of atmospheric perturbations interpreted as gravity waves and planetary waves are presented. Traveling planetary-wave contributions in the 25-85 km range were found to have significant height and latitudinal variation. It was found that observed gravity-wave density perturbations and wind are related to one another in the manner predicted by gravity-wave theory. It was determined that, on the average, gravity-wave energy deposition or reflection occurs at all altitudes except the 55-75 km region of the mesosphere.

  6. Evolutionary perspectives on human height variation

    NARCIS (Netherlands)

    Stulp, Gert; Barrett, Louise

    Human height is a highly variable trait, both within and between populations, has a high heritability, and influences the manner in which people behave and are treated in society. Although we know much about human height, this information has rarely been brought together in a comprehensive,

  7. Final height and intrauterine growth retardation.

    Science.gov (United States)

    Tauber, Maïthé

    2017-06-01

    Approximately 10% of small for gestational age (SGA) children maintain a small body size throughout childhood and often into adult life with a decreased pubertal spurt. Growth hormone (GH) therapy increases short-term growth in a dose-dependent manner and adult height had now been well documented. Shorter children might benefit from a higher dose at start (50μg/kg/day). The response to GH treatment was similar for both preterm and term short SGA groups and the effect of GH treatment on adult height showed a wide variation in growth response. As a whole, mean adult height is higher than -2 SDS in 60% of patients and 70% reached an adult height in their target height with better results with higher doses and combined GnRH analog therapy in those who were short at onset of puberty. Copyright © 2017. Published by Elsevier Masson SAS.

  8. Amplification of tsunami heights by delayed rupture of great earthquakes along the Nankai trough

    Science.gov (United States)

    Imai, K.; Satake, K.; Furumura, T.

    2010-04-01

    We investigated the effect of delayed rupture of great earthquakes along the Nankai trough on tsunami heights on the Japanese coast. As the tsunami source, we used a model of the 1707 Hoei earthquake, which consists of four segments: Tokai, Tonankai, and two Nankai segments. We first searched for the worst case, in terms of coastal tsunami heights, of rupture delay time on each segment, on the basis of superposition principle for the linear long wave theory. When the rupture starts on the Tonankai segment, followed by rupture on the Tokai segment 21 min later, as well as the eastern and western Nankai segments 15 and 28 min later, respectively, the average coastal tsunami height becomes the largest. To quantify the tsunami amplification, we compared the coastal tsunami heights from the delayed rupture with those from the simultaneous rupture model. Along the coasts of the sea of Hyu'uga and in the Bungo Channel, the tsunami heights become significantly amplified (>1.4 times larger) relative to the simultaneous rupture. Along the coasts of Tosa Bay and in the Kii Channel, the tsunami heights become amplified about 1.2 times. Along the coasts of the sea of Kumano and Ise Bay, and the western Enshu coast, the tsunami heights become slightly smaller for the delayed rupture. Along the eastern Enshu coast, the coast of Suruga Bay, and the west coast of Sagami Bay, the tsunami heights become amplified about 1.1 times.

  9. Nearly simultaneous measurements of radar auroral heights and Doppler velocities at 398 MHz

    International Nuclear Information System (INIS)

    Moorcroft, D.; Ruohoniemi, J.M.

    1987-01-01

    Nearly simultaneous measurements of radar auroral heights and Doppler velocities were obtained using the Homer, Alaska, 398-MHz phased-array radar over a total of 16 hours on four different days. The heights show a consistent variation with time, being highest near the time of electrojet current reversal, and lowest late in the morning. A variety of east-west height asymmetries were observed, different from those previously reported, which can be explained in terms of favorable flow angles preferentially favoring high-altitude primary two-stream waves to one side of the field of view. Low-velocity echoes, presumably due to secondary irregularities, are found to be more restricted in height range than echoes with ion acoustic velocities, which presumably come from primary two-stream instabilities. Echo power was examined as a function of velocity and height. For the westward electrojet it was found that echoes with ion acoustic velocities are relatively constant in strength over most of their height range, but for low-velocity echoes the power is a maximum between 100 and 105 km and falls off steadily at greater heights. Doppler speeds show a noticeable decrease at heights below 105 km, in agreement with the expected variation in ion acoustic velocity

  10. Height perception influenced by texture gradient.

    Science.gov (United States)

    Tozawa, Junko

    2012-01-01

    Three experiments were carried out to examine whether a texture gradient influences perception of relative object height. Previous research implicated texture cues in judgments of object width, but similar influences have not been demonstrated for relative height. In this study, I evaluate a hypothesis that the projective ratio of the number of texture elements covered by the objects combined with the ratio of the retinal object heights determines percepts of relative object height. Density of texture background was varied: four density conditions ranged from no-texture to very dense texture. In experiments 1 and 2, participants judged the height of comparison bar compared to the standard bar positioned on no-texture or textured backgrounds. Results showed relative height judgments differed with texture manipulations, consistent with predictions from a hypothesised combination of the number of texture elements with retinal height (experiment 1), or partially consistent with this hypothesis (experiment 2). In experiment 2, variations in the position of a comparison object showed that comparisons located far from the horizon were judged more poorly than in other positions. In experiment 3 I examined distance perception; relative distance judgments were found to be also affected by textured backgrounds. Results are discussed in terms of Gibson's relational theory and distance calibration theory.

  11. ALMA Telescope Reaches New Heights

    Science.gov (United States)

    2009-09-01

    ball at a distance of nine miles, and to keep their smooth reflecting surfaces accurate to less than the thickness of a human hair. Once the transporter reached the high plateau it carried the antenna to a concrete pad -- a docking station with connections for power and fiber optics -- and positioned it with an accuracy of a small fraction of an inch. The transporter is guided by a laser steering system and, just like some cars, also has ultrasonic collision detectors. These sensors ensure the safety of the state-of-the-art antennas as the transporter drives them across what will soon be a rather crowded plateau. Ultimately, ALMA will have at least 66 antennas distributed over about 200 pads, spread over distances of up to 11.5 miles and operating as a single, giant telescope. Even when ALMA is fully operational, the transporters will be used to move the antennas between pads to reconfigure the telescope for different kinds of observations. This first ALMA antenna at the high site will soon be joined by others, and the ALMA team looks forward to making their first observations from the Chajnantor plateau. They plan to link three antennas by early 2010, and to make the first scientific observations with ALMA in the second half of 2011. ALMA will help astronomers answer important questions about our cosmic origins. The telescope will observe the Universe using light with millimeter and submillimeter wavelengths, between infrared light and radio waves in the electromagnetic spectrum. Light at these wavelengths comes from some of the coldest, and from some of the most distant objects in the cosmos. These include cold clouds of gas and dust where new stars are being born, or remote galaxies towards the edge of the observable universe. The Universe is relatively unexplored at submillimeter wavelengths, as the telescopes need extremely dry atmospheric conditions, such as those at Chajnantor, and advanced detector technology. The Atacama Large Millimeter/submillimeter Array

  12. A study of acoustic halos in active region NOAA 11330 using multi-height SDO observations

    Science.gov (United States)

    Tripathy, S. C.; Jain, K.; Kholikov, S.; Hill, F.; Rajaguru, S. P.; Cally, P. S.

    2018-01-01

    We analyze data from the Helioseismic Magnetic Imager (HMI) and the Atmospheric Imaging Assembly (AIA) instruments on board the Solar Dynamics Observatory (SDO) to characterize the spatio-temporal acoustic power distribution in active regions as a function of the height in the solar atmosphere. For this, we use Doppler velocity and continuum intensity observed using the magnetically sensitive line at 6173 Å as well as intensity at 1600 Å and 1700 Å. We focus on the power enhancements seen around AR 11330 as a function of wave frequency, magnetic field strength, field inclination and observation height. We find that acoustic halos occur above the acoustic cutoff frequency and extends up to 10 mHz in HMI Doppler and AIA 1700 Å observations. Halos are also found to be strong functions of magnetic field and their inclination angle. We further calculate and examine the spatially averaged relative phases and cross-coherence spectra and find different wave characteristics at different heights.

  13. Global effects of income and income inequality on adult height and sexual dimorphism in height.

    Science.gov (United States)

    Bogin, Barry; Scheffler, Christiane; Hermanussen, Michael

    2017-03-01

    Average adult height of a population is considered a biomarker of the quality of the health environment and economic conditions. The causal relationships between height and income inequality are not well understood. We analyze data from 169 countries for national average heights of men and women and national-level economic factors to test two hypotheses: (1) income inequality has a greater association with average adult height than does absolute income; and (2) neither income nor income inequality has an effect on sexual dimorphism in height. Average height data come from the NCD-RisC health risk factor collaboration. Economic indicators are derived from the World Bank data archive and include gross domestic product (GDP), Gross National Income per capita adjusted for personal purchasing power (GNI_PPP), and income equality assessed by the Gini coefficient calculated by the Wagstaff method. Hypothesis 1 is supported. Greater income equality is most predictive of average height for both sexes. GNI_PPP explains a significant, but smaller, amount of the variation. National GDP has no association with height. Hypothesis 2 is rejected. With greater average adult height there is greater sexual dimorphism. Findings support a growing literature on the pernicious effects of inequality on growth in height and, by extension, on health. Gradients in height reflect gradients in social disadvantage. Inequality should be considered a pollutant that disempowers people from the resources needed for their own healthy growth and development and for the health and good growth of their children. © 2017 Wiley Periodicals, Inc.

  14. Quantification of Wave Model Uncertainties Used for Probabilistic Reliability Assessments of Wave Energy Converters

    DEFF Research Database (Denmark)

    Ambühl, Simon; Kofoed, Jens Peter; Sørensen, John Dalsgaard

    2015-01-01

    Wave models used for site assessments are subjected to model uncertainties, which need to be quantified when using wave model results for probabilistic reliability assessments. This paper focuses on determination of wave model uncertainties. Four different wave models are considered, and validation...... data are collected from published scientific research. The bias and the root-mean-square error, as well as the scatter index, are considered for the significant wave height as well as the mean zero-crossing wave period. Based on an illustrative generic example, this paper presents how the quantified...... uncertainties can be implemented in probabilistic reliability assessments....

  15. Determination of Wave Model Uncertainties used for Probabilistic Reliability Assessments of Wave Energy Devices

    DEFF Research Database (Denmark)

    Ambühl, Simon; Kofoed, Jens Peter; Sørensen, John Dalsgaard

    2014-01-01

    Wave models used for site assessments are subject to model uncertainties, which need to be quantified when using wave model results for probabilistic reliability assessments. This paper focuses on determination of wave model uncertainties. Considered are four different wave models and validation...... data is collected from published scientific research. The bias, the root-mean-square error as well as the scatter index are considered for the significant wave height as well as the mean zero-crossing wave period. Based on an illustrative generic example it is shown how the estimated uncertainties can...... be implemented in probabilistic reliability assessments....

  16. Forensic Physics 101: Falls from a height

    Science.gov (United States)

    Cross, Rod

    2008-09-01

    The physics of falling from a height, a topic that could be included in a course on forensic physics or in an undergraduate class as an example of Newton's laws, is applied to a common forensic problem.

  17. Estimating Mixing Heights Using Microwave Temperature Profiler

    Science.gov (United States)

    Nielson-Gammon, John; Powell, Christina; Mahoney, Michael; Angevine, Wayne

    2008-01-01

    A paper describes the Microwave Temperature Profiler (MTP) for making measurements of the planetary boundary layer thermal structure data necessary for air quality forecasting as the Mixing Layer (ML) height determines the volume in which daytime pollution is primarily concentrated. This is the first time that an airborne temperature profiler has been used to measure the mixing layer height. Normally, this is done using a radar wind profiler, which is both noisy and large. The MTP was deployed during the Texas 2000 Air Quality Study (TexAQS-2000). An objective technique was developed and tested for estimating the ML height from the MTP vertical temperature profiles. In order to calibrate the technique and evaluate the usefulness of this approach, estimates from a variety of measurements during the TexAQS-2000 were compared. Estimates of ML height were used from radiosondes, radar wind profilers, an aerosol backscatter lidar, and in-situ aircraft measurements in addition to those from the MTP.

  18. Soft computing methods for geoidal height transformation

    Science.gov (United States)

    Akyilmaz, O.; Özlüdemir, M. T.; Ayan, T.; Çelik, R. N.

    2009-07-01

    Soft computing techniques, such as fuzzy logic and artificial neural network (ANN) approaches, have enabled researchers to create precise models for use in many scientific and engineering applications. Applications that can be employed in geodetic studies include the estimation of earth rotation parameters and the determination of mean sea level changes. Another important field of geodesy in which these computing techniques can be applied is geoidal height transformation. We report here our use of a conventional polynomial model, the Adaptive Network-based Fuzzy (or in some publications, Adaptive Neuro-Fuzzy) Inference System (ANFIS), an ANN and a modified ANN approach to approximate geoid heights. These approximation models have been tested on a number of test points. The results obtained through the transformation processes from ellipsoidal heights into local levelling heights have also been compared.

  19. U.S. Geoid Heights (GEOID96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' geoid height grid for the conterminous United States is the GEOID96 model. The computation used about 1.8 million terrestrial and marine gravity data held in...

  20. PR/VI Geoid Heights (GEOID96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' geoid height grid for Puerto Rico and the Virgin Islands is distributed as a GEOID96 model. The computation used 26,000 terrestrial and marine gravity data...

  1. Principal Hawaiian Islands Geoid Heights (GEOID96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' geoid height grid for the Principal Hawaiian Islands is distributed as a GEOID96 model. The computation used 61,000 terrestrial and marine gravity data held...

  2. Simulation of three-phase flow and lance height effect on the cavity shape

    Science.gov (United States)

    Dong, Kai; Zhu, Rong; Gao, Wei; Liu, Fu-hai

    2014-06-01

    A three-dimensional computational fluid dynamics (CFD) model was developed to simulate a 150-t top-blown converter. The effect of different lance heights on the cavity shape was investigated using the volume of fluid (VOF) method. Numerical simulation results can reflect the actual molten bath surface waves impinged by the supersonic oxygen jets. With increasing lance height, the cavity depth decreases, and the cavity area, varying like a parabola, increases and then decreases. The cavity area maximizes at the lance height of 1.3 m. Under the three different lance heights simulated in this study, all of the largest impact velocities at the molten bath surface are between 50 m/s and 100 m/s.

  3. Distribution of runup heights of the December 26, 2004 tsunami in the Indian Ocean

    Science.gov (United States)

    Choi, Byung Ho; Hong, Sung Jin; Pelinovsky, Efim

    2006-07-01

    A massive earthquake with magnitude 9.3 occurred on December 26, 2004 off the northern Sumatra generated huge tsunami waves affected many coastal countries in the Indian Ocean. A number of field surveys have been performed after this tsunami event; in particular, several surveys in the south/east coast of India, Andaman and Nicobar Islands, Sri Lanka, Sumatra, Malaysia, and Thailand have been organized by the Korean Society of Coastal and Ocean Engineers from January to August 2005. Spatial distribution of the tsunami runup is used to analyze the distribution function of the wave heights on different coasts. Theoretical interpretation of this distribution is associated with random coastal bathymetry and coastline led to the log-normal functions. Observed data also are in a very good agreement with log-normal distribution confirming the important role of the variable ocean bathymetry in the formation of the irregular wave height distribution along the coasts.

  4. Book review: Extreme ocean waves

    Science.gov (United States)

    Geist, Eric L.

    2011-01-01

    ‘‘Extreme Ocean Waves’’ is a collection of ten papers edited by Efim Pelinovsky and Christian Kharif that followed the April 2007 meeting of the General Assembly of the European Geosciences Union. A note on terminology: extreme waves in this volume broadly encompass different types of waves, includ- ing deep-water and shallow-water rogue waves (alternatively termed freak waves), storm surges from cyclones, and internal waves. Other types of waves such as tsunamis or rissaga (meteotsunamis) are not discussed in this volume. It is generally implied that ‘‘extreme’’ has a statistical connotation relative to the average or significant wave height specific to each type of wave. Throughout the book, in fact, the reader will find a combination of theoretical and statistical/ empirical treatment necessary for the complete examination of this subject. In the introduction, the editors underscore the importance of studying extreme waves, documenting several dramatic instances of damaging extreme waves that occurred in 2007. 

  5. How to turn gravity waves into Alfven waves and other such tricks

    International Nuclear Information System (INIS)

    Newington, Marie E; Cally, Paul S

    2011-01-01

    Recent observations of travelling gravity waves at the base of the chromosphere suggest an interplay between gravity wave propagation and magnetic field. Our aims are: to explain the observation that gravity wave flux is suppressed in magnetic regions; to understand why we see travelling waves instead of standing waves; and to see if gravity waves can undergo mode conversion and couple to Alfven waves in regions where the plasma beta is of order unity. We model gravity waves in a VAL C atmosphere, subject to a uniform magnetic field of various orientations, considering both adiabatic and radiatively damped propagation. Results indicate that in the presence of a magnetic field, the gravity wave can propagate as a travelling wave, with the magnetic field orientation playing a crucial role in determining the wave character. For the majority of magnetic field orientations, the gravity wave is reflected at low heights as a slow magneto-acoustic wave, explaining the observation of reduced flux in magnetic regions. In a highly inclined magnetic field, the gravity wave undergoes mode conversion to either field guided acoustic waves or Alfven waves. The primary effect of incorporating radiative damping is a reduction in acoustic and magnetic fluxes measured at the top of the integration region. By demonstrating the mode conversion of gravity waves to Alfven waves, this work identifies a possible pathway for energy transport from the solar surface to the upper atmosphere.

  6. Love and fear of heights: the pathophysiology and psychology of height imbalance.

    Science.gov (United States)

    Salassa, John R; Zapala, David A

    2009-01-01

    Individual psychological responses to heights vary on a continuum from acrophobia to height intolerance, height tolerance, and height enjoyment. This paper reviews the English literature and summarizes the physiologic and psychological factors that generate different responses to heights while standing still in a static or motionless environment. Perceptual cues to height arise from vision. Normal postural sway of 2 cm for peripheral objects within 3 m increases as eye-object distance increases. Postural sway >10 cm can result in a fall. A minimum of 20 minutes of peripheral retinal arc is required to detect motion. Trigonometry dictates that a 20-minute peripheral retinal arch can no longer be achieved in a standing position at an eye-object distance of >20 m. At this distance, visual cues conflict with somatosensory and vestibular inputs, resulting in variable degrees of imbalance. Co-occurring deficits in the visual, vestibular, and somatosensory systems can significantly increase height imbalance. An individual's psychological makeup, influenced by learned and genetic factors, can influence reactions to height imbalance. Enhancing peripheral vision and vestibular, proprioceptive, and haptic functions may improve height imbalance. Psychotherapy may improve the troubling subjective sensations to heights.

  7. Social inequalities in height: persisting differences today depend upon height of the parents.

    Directory of Open Access Journals (Sweden)

    Bruna Galobardes

    Full Text Available Substantial increases in height have occurred concurrently with economic development in most populations during the last century. In high-income countries, environmental exposures that can limit genetic growth potential appear to have lessened, and variation in height by socioeconomic position may have diminished. The objective of this study is to investigate inequalities in height in a cohort of children born in the early 1990s in England, and to evaluate which factors might explain any identified inequalities.12,830 children from The Avon Longitudinal Study of Parents and Children (ALSPAC, a population based cohort from birth to about 11.5 years of age, were used in this analysis. Gender- and age-specific z-scores of height at different ages were used as outcome variables. Multilevel models were used to take into account the repeated measures of height and to analyze gender- and age-specific relative changes in height from birth to 11.5 years. Maternal education was the main exposure variable used to examine socioeconomic inequalities. The roles of parental and family characteristics in explaining any observed differences between maternal education and child height were investigated. Children whose mothers had the highest education compared to those with none or a basic level of education, were 0.39 cm longer at birth (95% CI: 0.30 to 0.48. These differences persisted and at 11.5 years the height difference was 1.4 cm (95% CI: 1.07 to 1.74. Several other factors were related to offspring height, but few changed the relationship with maternal education. The one exception was mid-parental height, which fully accounted for the maternal educational differences in offspring height.In a cohort of children born in the 1990s, mothers with higher education gave birth to taller boys and girls. Although height differences were small they persisted throughout childhood. Maternal and paternal height fully explained these differences.

  8. Extreme Waves in Svåheia SSG Location

    DEFF Research Database (Denmark)

    Margheritini, Lucia; Kofoed, Jens Peter

    The present report is the written documentation of the work carried under a consultancy project agreement between WaveEnergy AS and Aalborg University (AAU). The purpose of the study is to define maximum wave heights and related waves loading acting on the SSG in Svaheia, Norway and to provide th...

  9. Oscillatory infragravity wave contribution to surf zone sediment transport

    DEFF Research Database (Denmark)

    Aagaard, Troels; Greenwood, Brian

    2008-01-01

    . It is shown that infragravity sediment transports are onshore directed at the landward side of relative (incident) wave height maxima, and offshore directed at the seaward side of such maxima. If a longshore infragravity wave structure exists, such as in the case of standing edge waves, the advection process...

  10. Directional wave measurements off Navinal, Gulf of Kachchh, India

    Digital Repository Service at National Institute of Oceanography (India)

    Vethamony, P.; KrishnaKumar, V.; Suryanarayana, A.; Antony, M.K.; Swamy, G.N.

    .54 m respectively. Though large wave heights of the order of 3 to 4m exist elsewhere along the west coast of India during these seasons, Navinal seems to be a less wave active zone because of its geographical location. Maximum wave energy is centred...

  11. Analysis of wave directional spreading using neural networks

    Digital Repository Service at National Institute of Oceanography (India)

    Deo, M.C.; Gondane, D.S.; SanilKumar, V.

    describes how a representative spreading parameter could be arrived at from easily available wave parameters such as significant wave height and average zero-cross wave period, using the technique of neural networks. It is shown that training of the network...

  12. Zonal Wave Number 2 Rossby Wave (3.5-day oscillation) Over The Martian Lower Atmosphere

    Science.gov (United States)

    Ghosh, P.; Thokuluwa, R. K.

    2013-12-01

    Over the Mars, height (800-50 Pascal pressure coordinate) profiles of temperature (K), measured by radio occultation technique during the MGS (Mars Global Surveyor) mission, obtained for the period of 1-10 January 2006 at the Martian latitude of ~63N in almost all the longitudes are analyzed to study the characteristics of the 3.5-day oscillation. To avoid significant data gaps in a particular longitude sector, we selected a set of 7 Mars longitude regions with ranges of 0-30E, 35-60E, 65-95E, 190-230E, 250-280E, 290-320E, and 325-360E to study the global characteristics of the 3.5-day oscillation. The 3.5-day oscillation is not selected as a-priori but observed as a most significant oscillation during this period of 1-10 January 2006. It is observed that in the longitude of 0-30E, the 3.5-day oscillation shows statistically significant power (above the 95% confidence level white noise) from the lowest height (800 Pascal, 8 hPa) itself and up to the height of 450 Pascal level with the maximum power of ~130 K^2 at the 600 & 650 Pascal levels. It started to grow from the power of ~ 50 K^2 at the lowest height of 800 Pascal level and reached the maximum power in the height of 600-650 Pascal level and then it started to get lessened monotonously up to the height of 450 Pascal level where its power is ~ 20 K^2. Beyond this height and up to the height of 50 Pascal level, the wave amplitude is below the white noise level. As the phase of the wave is almost constant at all the height levels, it seems that the observed 3.5-day oscillation is a stationary wave with respect to the height. In the 35-60 E longitude sector, the vertical structure of the 3.5-day oscillation is similar to what observed for the 0-30 E longitude region but the power is statistically insignificant at all the heights. However in the 65-95E longitude sector, the wave grows from the lowest level (70 K^2) of 800 Pascal to its maximum power of 280 K^2 in the height of 700 Pascal level and then it started

  13. Birth order progressively affects childhood height.

    Science.gov (United States)

    Savage, Tim; Derraik, José G B; Miles, Harriet L; Mouat, Fran; Cutfield, Wayne S; Hofman, Paul L

    2013-09-01

    There is evidence suggesting that first-born children and adults are anthropometrically different to later-borns. Thus, we aimed to assess whether birth order was associated with changes in growth and metabolism in childhood. We studied 312 healthy prepubertal children: 157 first-borns and 155 later-borns. Children were aged 3-10 years, born 37-41 weeks gestation, and of birth weight appropriate-for-gestational-age. Clinical assessments included measurement of children's height, weight, fasting lipid and hormonal profiles and DEXA-derived body composition. First-borns were taller than later-borns (P < 0·0001), even when adjusted for parents' heights (0·31 vs 0·03 SDS; P = 0·001). There was an incremental height decrease with increasing birth order, so that first-borns were taller than second-borns (P < 0·001), who were in turn taller than third-borns (P = 0·007). Further, among sibling pairs both height SDS (P = 0·009) and adjusted height SDS (P < 0·0001) were lower in second- vs first-born children. Consistent with differences in stature, first- (P = 0·043) and second-borns (P = 0·003) had higher IGF-I concentrations than third-borns. Both first- (P < 0·001) and second-borns (P = 0·004) also had reduced abdominal adiposity (lower android fat to gynoid fat ratio) when compared with third-borns. Other parameters of adiposity and blood lipids were unaffected by birth order. First-borns were taller than later-born children, with an incremental height reduction from first to third birth order. These differences were present after correction for genetic height, and associated to some extent with alterations in plasma IGF-I. Our findings strengthen the evidence that birth order is associated with phenotypic changes in childhood. © 2013 John Wiley & Sons Ltd.

  14. A multimodal wave spectrum-based approach for statistical downscaling of local wave climate

    Science.gov (United States)

    Hegermiller, Christie; Antolinez, Jose A A; Rueda, Ana C.; Camus, Paula; Perez, Jorge; Erikson, Li; Barnard, Patrick; Mendez, Fernando J.

    2017-01-01

    Characterization of wave climate by bulk wave parameters is insufficient for many coastal studies, including those focused on assessing coastal hazards and long-term wave climate influences on coastal evolution. This issue is particularly relevant for studies using statistical downscaling of atmospheric fields to local wave conditions, which are often multimodal in large ocean basins (e.g. the Pacific). Swell may be generated in vastly different wave generation regions, yielding complex wave spectra that are inadequately represented by a single set of bulk wave parameters. Furthermore, the relationship between atmospheric systems and local wave conditions is complicated by variations in arrival time of wave groups from different parts of the basin. Here, we address these two challenges by improving upon the spatiotemporal definition of the atmospheric predictor used in statistical downscaling of local wave climate. The improved methodology separates the local wave spectrum into “wave families,” defined by spectral peaks and discrete generation regions, and relates atmospheric conditions in distant regions of the ocean basin to local wave conditions by incorporating travel times computed from effective energy flux across the ocean basin. When applied to locations with multimodal wave spectra, including Southern California and Trujillo, Peru, the new methodology improves the ability of the statistical model to project significant wave height, peak period, and direction for each wave family, retaining more information from the full wave spectrum. This work is the base of statistical downscaling by weather types, which has recently been applied to coastal flooding and morphodynamic applications.

  15. Wave forecasting and monitoring during very severe cyclone Phailin in the Bay of Bengal.

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, T.M.B; Remya, P.G.; Harikumar, R.; Sandhya, K.G.; Sirisha, P.; Srinivas, K.; Nagaraju, C.; Nherakkol, A.; KrishnaPrasad, B.; Jeyakumar, C.; Kaviyazhahu, K.; Hithin, N.K.; Kumari, R.; SanilKumar, V.; RameshKumar, M.; Shenoi, S.S.C.; Nayak, S.

    Wave fields, both measured and forecast during the very severe cyclone Phailin, are discussed in this communication. Waves having maximum height of 13.54 m were recorded at Gopalpur, the landfall point of the cyclone. The forecast and observed...

  16. Wave direction and other data from fixed platform from TOGA Area - Pacific (30 N to 30 S) from 19931027 to 19950531 (NODC Accession 9500087)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This accession contains two Wave Energy (wave height and wave period) Data files from Hawaiian coast (Kahului and Mauai islands) collected in TOGA Area - Pacific (30...

  17. WAVE DIRECTION and Other Data from FIXED PLATFORM From North Pacific Ocean and Others from 19810817 to 19940323 (NODC Accession 9400105)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This accession contains Wave Energy (wave height and wave period) Data from Hawaiian coast collected over 13 years in North Pacific Ocean, NE Pacific (limit-180)....

  18. Plasma waves

    CERN Document Server

    Swanson, DG

    1989-01-01

    Plasma Waves discusses the basic development and equations for the many aspects of plasma waves. The book is organized into two major parts, examining both linear and nonlinear plasma waves in the eight chapters it encompasses. After briefly discussing the properties and applications of plasma wave, the book goes on examining the wave types in a cold, magnetized plasma and the general forms of the dispersion relation that characterize the waves and label the various types of solutions. Chapters 3 and 4 analyze the acoustic phenomena through the fluid model of plasma and the kinetic effects. Th

  19. Seasonal variability in virtual height of ionospheric f/sub 2/ layer at the pakistan atmospheric region

    International Nuclear Information System (INIS)

    Jilani, A.A.; Afridi, F.A.K.; Mian, K.; Zai, M.A.K.Y.

    2013-01-01

    The aim of this study was to assess the seasonal variability in virtual height of ionospheric F/sub 2/ layer for Pakistan's atmospheric region (PAR). In this communication virtual height variations have been analyzed by the descriptive statistical techniques. These methodologies comprise an autoregressive strategy, linear regression and polynomial regression. The relevance of these models has been illuminated using predicted values of different parameters under the seasonal variation of ionospheric F/sub 2/ layer in virtual height that affect the radio wave propagation through the ionosphere. These techniques are implemented to theorize the physical process of varying the virtual heights that leads this study towards formulating the variations due to interaction of radio wave propagation with this ionospheric layer. (author)

  20. Trend analysis of the wave storminess: the wave direction

    Science.gov (United States)

    Casas Prat, M.; Sierra, J. P.; Mösso, C.; Sánchez-Arcilla, A.

    2009-09-01

    Climate change has an important role in the current scientific research because of its possible future negative consequences. Concerning the climate change in the coastal engineering field, the apparent sea level rise is one of the key parameters as well as the wave height and the wave direction temporal variations. According to the IPCC (2007), during the last century the sea level has been increasing with a mean rate of 1.7 ± 0.5 mm/yr. However, at local/regional scale the tendency significantly differs from the global trend since the local pressure and wind field variations become more relevant. This appears to be particularly significant in semi-enclosed areas in the Mediterranean Sea (Cushman-Roisin et al., 2001). Even though the existing unsolved questions related to the sea level rise, the uncertainty concerning the wave height is even larger, in which stormy conditions are especially important because they are closely related to processes such as coastal erosion, flooding, etc. Therefore, it is necessary to identify possible existing tendencies of storm related parameters. In many studies, only the maximum wave height and storm duration are analysed, remaining the wave direction in a second term. Note that a possible rotation of the mean wave direction may involve severe consequences since most beach and harbour defence structures have been designed assuming a constant predominant wave incidence. Liste et al. (2004) illustrated this fact with an example in which a rotation of only 2 degrees of the mean energy flux vector could produce a beach retreat of 20 m. Another possible consequence would be a decrease of the harbour operability: increased frequency of storms in the same direction as the harbour entrance orientation would influence the navigability. The present study, which focuses in the Catalan coast (NW Mediterranean Sea), aims to improve the present knowledge of the wave storminess variations at regional scale, specially focusing on the wave

  1. The height of watermelons with wall

    International Nuclear Information System (INIS)

    Feierl, Thomas

    2012-01-01

    We derive asymptotics for the moments as well as the weak limit of the height distribution of watermelons with p branches with wall. This generalizes a famous result of de Bruijn et al (1972 Graph Theory and Computing (New York: Academic) pp 15–22) on the average height of planted plane trees, and results by Fulmek (2007 Electron. J. Combin. 14 R64) and Katori et al (2008 J. Stat. Phys. 131 1067–83) on the expected value and higher moments, respectively, of the height distribution of watermelons with two branches. The asymptotics for the moments depend on the analytic behaviour of certain multidimensional Dirichlet series. In order to obtain this information, we prove a reciprocity relation satisfied by the derivatives of one of Jacobi’s theta functions, which generalizes the well-known reciprocity law for Jacobi’s theta functions. (paper)

  2. Experiences of ZAMG on mixing height determination

    Energy Technology Data Exchange (ETDEWEB)

    Piringer, M. [Zentralanstalt fuer Meteorologie und Geodynamik, ZAMG, Vienna (Austria)

    1997-10-01

    Temperature inversions in the boundary layer occur quite often, esp. in mountainous terrain by which Austria is covered to a large extent, and can lead to enhanced pollution at the surface because the air volume available for dilution is then vertically limited. The Department of Environmental Meteorology of ZAMG therefore set up several field programs in the past to study such conditions at a variety of sites in Austria, using tethersondes and Sodars. Early investigations aimed at comparing Sodar echo profiles to the tethersonde temperature profiles to derive mixing heights from the Sodar echo structure. More recently, evolving from KONGEX, the `convective boundary layer experiment`, mixing heights calculated for Vienna by the OML model were compared to those derived from radiosonde and tethersonde potential temperature profiles. Results of these investigations will be presented, focussing on the problems when using the different methods. New efforts to derive mixing heights from data were also undertaken and are discussed separately. (au)

  3. Height, Relationship Satisfaction, Jealousy, and Mate Retention

    Directory of Open Access Journals (Sweden)

    Gayle Brewer

    2009-07-01

    Full Text Available Male height is associated with high mate value. In particular, tall men are perceived as more attractive, dominant and of a higher status than shorter rivals, resulting in a greater lifetime reproductive success. Female infidelity and relationship dissolution may therefore present a greater risk to short men. It was predicted that tall men would report greater relationship satisfaction and lower jealousy and mate retention behavior than short men. Ninety eight heterosexual men in a current romantic relationship completed a questionnaire. Both linear and quadratic relationships were found between male height and relationship satisfaction, cognitive and behavioral jealousy. Tall men reported greater relationship satisfaction and lower levels of cognitive or behavioral jealousy than short men. In addition, linear and quadratic relationships were found between male height and a number of mate retention behaviors. Tall and short men engaged in different mate retention behaviors. These findings are consistent with previous research conducted in this area detailing the greater attractiveness of tall men.

  4. Rogue Waves in the Ocean

    Science.gov (United States)

    Waseda, Takuji

    2010-03-01

    Giant episodic ocean waves that suddenly soar like a wall of water out of an otherwise calm sea are not just a legend. Such waves—which in the past have been called “abnormal,” “exceptional,” “extreme,” and even “vicious killer” waves—are now commonly known as “rogue waves” or “freak waves.” These waves have sunk or severely damaged 22 supercarriers in the world and caused the loss of more than 500 lives in the past 40 years. The largest wave registered by reliable instruments reached 30 meters in height, and the largest wave recorded by visual observation reached about 34 meters, equivalent to the height of an eight-story building. Tales of seafarers from Christopher Columbus to the passengers of luxury cruise ships had long been undervalued by scientists, but in the past 10 or so years, those historical notes and modern testimonies have been scientifically dissected to reveal the nature of these monster waves.

  5. Wave Analysis for West Coast of South Myanmar

    Directory of Open Access Journals (Sweden)

    Xu Yanan

    2015-01-01

    Full Text Available The characteristic of southern parts of Myanmar is tropical monsoon climate, and this area is affected by few typhoons. The wave height is changed with season, the field measured data shows that the aver-age monthly maximum wave height is in June. The wave height, swelling from Indian Ocean and spreading to research area, is small. The research adopts SWAN model to simulate the waves that are transformed from off-shore to nearshore Myanmar based on the meteorological data from ECMWF. The simulated results were com-pared with satellite data and field measured data, it showed that the trend between the curves is unified, and the extreme value of simulation is close to the measured value. The simulation presents wave distribution around Myanmar southern sea, it shows that the wave height and wave directions are affected by terrain refraction and island trains shielding. When the wave is from WSW direction, the wave will be decreased fast caused by island shielding, and the direction turns to W direction at northern coastline. When the wave comes from SSW direction, the island shielding will be weak, the wave will be decreased slowly, and the direction will turn to SW direction at southern coastline.

  6. Evidence of inbreeding depression on human height.

    Directory of Open Access Journals (Sweden)

    Ruth McQuillan

    Full Text Available Stature is a classical and highly heritable complex trait, with 80%-90% of variation explained by genetic factors. In recent years, genome-wide association studies (GWAS have successfully identified many common additive variants influencing human height; however, little attention has been given to the potential role of recessive genetic effects. Here, we investigated genome-wide recessive effects by an analysis of inbreeding depression on adult height in over 35,000 people from 21 different population samples. We found a highly significant inverse association between height and genome-wide homozygosity, equivalent to a height reduction of up to 3 cm in the offspring of first cousins compared with the offspring of unrelated individuals, an effect which remained after controlling for the effects of socio-economic status, an important confounder (χ(2 = 83.89, df = 1; p = 5.2 × 10(-20. There was, however, a high degree of heterogeneity among populations: whereas the direction of the effect was consistent across most population samples, the effect size differed significantly among populations. It is likely that this reflects true biological heterogeneity: whether or not an effect can be observed will depend on both the variance in homozygosity in the population and the chance inheritance of individual recessive genotypes. These results predict that multiple, rare, recessive variants influence human height. Although this exploratory work focuses on height alone, the methodology developed is generally applicable to heritable quantitative traits (QT, paving the way for an investigation into inbreeding effects, and therefore genetic architecture, on a range of QT of biomedical importance.

  7. Adult height, dietary patterns, and healthy aging.

    Science.gov (United States)

    Ma, Wenjie; Hagan, Kaitlin A; Heianza, Yoriko; Sun, Qi; Rimm, Eric B; Qi, Lu

    2017-08-01

    Background: Adult height has shown directionally diverse associations with several age-related disorders, including cardiovascular disease, cancer, decline in cognitive function, and mortality. Objective: We investigated the associations of adult height with healthy aging measured by a full spectrum of health outcomes, including incidence of chronic diseases, memory, physical functioning, and mental health, among populations who have survived to older age, and whether lifestyle factors modified such relations. Design: We included 52,135 women (mean age: 44.2 y) from the Nurses' Health Study without chronic diseases in 1980 and whose health status was available in 2012. Healthy aging was defined as being free of 11 major chronic diseases and having no reported impairment of subjective memory, physical impairment, or mental health limitations. Results: Of all eligible study participants, 6877 (13.2%) were classified as healthy agers. After adjustment for demographic and lifestyle factors, we observed an 8% (95% CI: 6%, 11%) decrease in the odds of healthy aging per SD (0.062 m) increase in height. Compared with the lowest category of height (≤1.57 m), the OR of achieving healthy aging in the highest category (≥1.70 m) was 0.80 (95% CI: 0.73, 0.87; P -trend healthy aging ( P -interaction = 0.005), and among the individual dietary factors characterizing the prudent dietary pattern, fruit and vegetable intake showed the strongest effect modification ( P -interaction = 0.01). The association of greater height with reduced odds of healthy aging appeared to be more evident among women with higher adherence to the prudent dietary pattern rich in vegetable and fruit intake. Conclusions: Greater height was associated with a modest decrease in the likelihood of healthy aging. A prudent diet rich in fruit and vegetables might modify the relation. © 2017 American Society for Nutrition.

  8. Variability in wave refraction and resultant nearshore current patterns: Exposed versus sheltered beaches along north Karnataka, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Veerayya, M.; Pankajakshan, T.

    of wave heights in headland-bays and at river mouths. Certain stretches of open ocean beaches located on either side of the Kali River and the headland-bay beaches south of Karwar Head experience relatively higher wave heights for W and WSW waves...

  9. Heat Waves

    Science.gov (United States)

    Heat Waves Dangers we face during periods of very high temperatures include: Heat cramps: These are muscular pains and spasms due ... that the body is having trouble with the heat. If a heat wave is predicted or happening… - ...

  10. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Brorsen, Michael; Frigaard, Peter

    Denne rapport beskriver numeriske beregninger af forskellige flydergeometrier for bølgeenergianlæget Wave Star.......Denne rapport beskriver numeriske beregninger af forskellige flydergeometrier for bølgeenergianlæget Wave Star....

  11. Gravitational Waves

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Jonah Maxwell [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-18

    This report has slides on Gravitational Waves; Pound and Rebka: A Shocking Fact; Light is a Ruler; Gravity is the Curvature of Spacetime; Gravitational Waves Made Simple; How a Gravitational Wave Affects Stuff Here; LIGO; This Detection: Neutron Stars; What the Gravitational Wave Looks Like; The Sound of Merging Neutron Stars; Neutron Star Mergers: More than GWs; The Radioactive Cloud; The Kilonova; and finally Summary, Multimessenger Astronomy.

  12. Wave phenomena

    CERN Document Server

    Towne, Dudley H

    1988-01-01

    This excellent undergraduate-level text emphasizes optics and acoustics, covering inductive derivation of the equation for transverse waves on a string, acoustic plane waves, boundary-value problems, polarization, three-dimensional waves and more. With numerous problems (solutions for about half). ""The material is superbly chosen and brilliantly written"" - Physics Today. Problems. Appendices.

  13. Electromagnetic Waves

    DEFF Research Database (Denmark)

    This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis......, material characterization, electromagnetic properties of plasma, analysis and applications of periodic structures and waveguide components, etc....

  14. Wave Dragon

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Frigaard, Peter; Sørensen, H. C.

    1998-01-01

    This paper concerns with the development of the wave energy converter (WEC) Wave Dragon. This WEC is based on the overtopping principle. An overview of the performed research done concerning the Wave Dragon over the past years is given, and the results of one of the more comprehensive studies, co...

  15. Tree height and tropical forest biomass estimation

    Science.gov (United States)

    M.O. Hunter; M. Keller; D. Vitoria; D.C. Morton

    2013-01-01

    Tropical forests account for approximately half of above-ground carbon stored in global vegetation. However, uncertainties in tropical forest carbon stocks remain high because it is costly and laborious to quantify standing carbon stocks. Carbon stocks of tropical forests are determined using allometric relations between tree stem diameter and height and biomass....

  16. Falls from height: A retrospective analysis.

    Science.gov (United States)

    Turgut, Kasim; Sarihan, Mehmet Ediz; Colak, Cemil; Güven, Taner; Gür, Ali; Gürbüz, Sükrü

    2018-01-01

    Emergency services manage trauma patients frequently and falls from height comprise the main cause of emergency service admissions. In this study, we aimed to analyse the demographic characteristics of falls from height and their relationship to the mortality. A total of 460 patients, who admitted to the Emergency Department of Inonu University between November 2011 and November 2014 with a history of fall from height, were examined retrospectively. Demographic parameters, fall characteristics and their effect to mortality were evaluated statistically. The study comprised of 292 (63.5%) men and 168 (36.5%) women patients. The mean age of all patients was 27±24.99 years. Twenty-six (5.6%) patients died and the majority of them were in ≥62 years old group. The highest percentage of falls was at 0-5 years age group (28.3%). People fell mainly from 1.1-4 metres(m) level (46.1%). The causes of falls were ordered as unintentional (92.2%), workplace (8.1%) and suicidal (1.7%). Skin and soft tissue injuries (37.4%) were the main traumatic lesions. Age, fall height, fall place, lineer skull fracture, subarachnoidal hemorrhage, cervical fracture, thoracic vertebra fracture and trauma scores had statistically significant effect on mortality. The casualties died because of subarachnoid hemorrhage mostly.

  17. Optimizing height presentation for aircraft cockpit displays

    Science.gov (United States)

    Jordan, Chris S.; Croft, D.; Selcon, Stephen J.; Markin, H.; Jackson, M.

    1997-02-01

    This paper describes an experiment conducted to investigate the type of display symbology that most effectively conveys height information to users of head-down plan-view radar displays. The experiment also investigated the use of multiple information sources (redundancy) in the design of such displays. Subjects were presented with eight different height display formats. These formats were constructed from a control, and/or one, two, or three sources of redundant information. The three formats were letter coding, analogue scaling, and toggling (spatially switching the position of the height information from above to below the aircraft symbol). Subjects were required to indicate altitude awareness via a four-key, forced-choice keyboard response. Error scores and response times were taken as performance measures. There were three main findings. First, there was a significant performance advantage when the altitude information was presented above and below the symbol to aid the representation of height information. Second, the analogue scale, a line whose length indicated altitude, proved significantly detrimental to performance. Finally, no relationship was found between the number of redundant information sources employed and performance. The implications for future aircraft and displays are discussed in relation to current aircraft tactical displays and in the context of perceptual psychological theory.

  18. Pulse height model for deuterated scintillation detectors

    International Nuclear Information System (INIS)

    Wang, Haitang; Enqvist, Andreas

    2015-01-01

    An analytical model of light pulse height distribution for finite deuterated scintillation detectors is created using the impulse approximation. Particularly, the energy distribution of a scattered neutron is calculated based on an existing collision probability scheme for general cylindrical shaped detectors considering double differential cross-sections. The light pulse height distribution is analytically and numerically calculated by convoluting collision sequences with the light output function for an EJ-315 detector from our measurements completed at Ohio University. The model provides a good description of collision histories capturing transferred neutron energy in deuterium-based scintillation materials. The resulting light pulse height distribution details pulse compositions and their corresponding contributions. It shows that probabilities of neutron collision with carbon and deuterium nuclei are comparable, however the light pulse amplitude due to collisions with carbon nuclei is small and mainly located at the lower region of the light pulse distribution axis. The model can explore those neutron interaction events that generate pulses near or below a threshold that would be imposed in measurements. A comparison is made between the light pulse height distributions given by the analytical model and measurements. It reveals a significant probability of a neutron generating a small light pulse due to collisions with carbon nuclei when compared to larger light pulse generated by collisions involving deuterium nuclei. This model is beneficial to understand responses of scintillation materials and pulse compositions, as well as nuclei information extraction from recorded pulses.

  19. Aircraft height estimation using 2-D radar

    CSIR Research Space (South Africa)

    Hakl, H

    2010-01-01

    Full Text Available A method to infer height information from an aircraft tracked with a single 2-D search radar is presented. The method assumes level flight in the target aircraft and a good estimate of the speed of the aircraft. The method yields good results...

  20. Evidence of inbreeding depression on human height

    NARCIS (Netherlands)

    R. McQuillan (Ruth); N. Eklund (Niina); N. Pirastu (Nicola); M. Kuningas (Maris); B.P. McEvoy (Brian); T. Esko (Tõnu); T. Corre (Tanguy); G. Davies (Gail); M. Kaakinen (Marika); L.-P. Lyytikäinen (Leo-Pekka); K. Kristiansson (Kati); A.S. Havulinna (Aki); M. Gögele (Martin); V. Vitart (Veronique); A. Tenesa (Albert); Y.S. Aulchenko (Yurii); C. Hayward (Caroline); A. Johansson (Åsa); M. Boban (Mladen); S. Ulivi (Shelia); A. Robino (Antonietta); V. Boraska (Vesna); W. Igl (Wilmar); S.H. Wild (Sarah); L. Zgaga (Lina); N. Amin (Najaf); E. Theodoratou (Evropi); O. Polasek (Ozren); S. Girotto; L.M. Lopez (Lorna); C. Sala (Cinzia); J. Lahti (Jari); T. Laatikainen (Tiina); I. Prokopenko (Inga); M. Kals (Mart); J. Viikari (Jorma); J. Yang (Joanna); A. Pouta (Anneli); K. Estrada Gil (Karol); A. Hofman (Albert); N.B. Freimer (Nelson); N.G. Martin (Nicholas); M. Kähönen (Mika); L. Milani (Lili); M. Heliovaara (Markku); E. Vartiainen (Erkki); K. Räikkönen (Katri); C. Masciullo (Corrado); J.M. Starr (John); A.A. Hicks (Andrew); L. Esposito (Laura); I. Kolcic (Ivana); S.M. Farrington (Susan); B.A. Oostra (Ben); T. Zemunik (Tatijana); H. Campbell (Harry); M. Kirin (Mirna); M. Pehlic (Marina); F. Faletra (Flavio); D.J. Porteous (David J.); G. Pistis (Giorgio); E. Widen (Elisabeth); V. Salomaa (Veikko); S. Koskinen (Seppo); K. Fischer (Krista); T. Lehtimäki (Terho); A.C. Heath (Andrew); M.I. McCarthy (Mark); F. Rivadeneira Ramirez (Fernando); G.W. Montgomery (Grant); H.W. Tiemeier (Henning); A.L. Hartikainen; P.A.F. Madden (Pamela); P. d' Adamo (Pio); N. Hastie (Nick); U. Gyllensten (Ulf); A.F. Wright (Alan); C.M. van Duijn (Cornelia); M.G. Dunlop (Malcolm); I. Rudan (Igor); P. Gasparini (Paolo); P.P. Pramstaller (Peter Paul); I.J. Deary (Ian); D. Toniolo (Daniela); K. Hagen (Knut); A. Jula (Antti); O. Raitakari (Olli); A. Metspalu (Andres); M. Perola (Markus); M.-R. Jarvelin (Marjo-Riitta); A.G. Uitterlinden (André); P.M. Visscher (Peter); J.F. Wilson (James)

    2012-01-01

    textabstractStature is a classical and highly heritable complex trait, with 80%-90% of variation explained by genetic factors. In recent years, genome-wide association studies (GWAS) have successfully identified many common additive variants influencing human height; however, little attention has

  1. Predicting vertical jump height from bar velocity.

    Science.gov (United States)

    García-Ramos, Amador; Štirn, Igor; Padial, Paulino; Argüelles-Cienfuegos, Javier; De la Fuente, Blanca; Strojnik, Vojko; Feriche, Belén

    2015-06-01

    The objective of the study was to assess the use of maximum (Vmax) and final propulsive phase (FPV) bar velocity to predict jump height in the weighted jump squat. FPV was defined as the velocity reached just before bar acceleration was lower than gravity (-9.81 m·s(-2)). Vertical jump height was calculated from the take-off velocity (Vtake-off) provided by a force platform. Thirty swimmers belonging to the National Slovenian swimming team performed a jump squat incremental loading test, lifting 25%, 50%, 75% and 100% of body weight in a Smith machine. Jump performance was simultaneously monitored using an AMTI portable force platform and a linear velocity transducer attached to the barbell. Simple linear regression was used to estimate jump height from the Vmax and FPV recorded by the linear velocity transducer. Vmax (y = 16.577x - 16.384) was able to explain 93% of jump height variance with a standard error of the estimate of 1.47 cm. FPV (y = 12.828x - 6.504) was able to explain 91% of jump height variance with a standard error of the estimate of 1.66 cm. Despite that both variables resulted to be good predictors, heteroscedasticity in the differences between FPV and Vtake-off was observed (r(2) = 0.307), while the differences between Vmax and Vtake-off were homogenously distributed (r(2) = 0.071). These results suggest that Vmax is a valid tool for estimating vertical jump height in a loaded jump squat test performed in a Smith machine. Key pointsVertical jump height in the loaded jump squat can be estimated with acceptable precision from the maximum bar velocity recorded by a linear velocity transducer.The relationship between the point at which bar acceleration is less than -9.81 m·s(-2) and the real take-off is affected by the velocity of movement.Mean propulsive velocity recorded by a linear velocity transducer does not appear to be optimal to monitor ballistic exercise performance.

  2. A GEOMETRICAL HEIGHT SCALE FOR SUNSPOT PENUMBRAE

    International Nuclear Information System (INIS)

    Puschmann, K. G.; Ruiz Cobo, B.; MartInez Pillet, V.

    2010-01-01

    Inversions of spectropolarimetric observations of penumbral filaments deliver the stratification of different physical quantities in an optical depth scale. However, without establishing a geometrical height scale, their three-dimensional geometrical structure cannot be derived. This is crucial in understanding the correct spatial variation of physical properties in the penumbral atmosphere and to provide insights into the mechanism capable of explaining the observed penumbral brightness. The aim of this work is to determine a global geometrical height scale in the penumbra by minimizing the divergence of the magnetic field vector and the deviations from static equilibrium as imposed by a force balance equation that includes pressure gradients, gravity, and the Lorentz force. Optical depth models are derived from the inversion of spectropolarimetric data of an active region observed with the Solar Optical Telescope on board the Hinode satellite. We use a genetic algorithm to determine the boundary condition for the inference of geometrical heights. The retrieved geometrical height scale permits the evaluation of the Wilson depression at each pixel and the correlation of physical quantities at each height. Our results fit into the uncombed penumbral scenario, i.e., a penumbra composed of flux tubes with channeled mass flow and with a weaker and more horizontal magnetic field as compared with the background field. The ascending material is hotter and denser than their surroundings. We do not find evidence of overturning convection or field-free regions in the inner penumbral area analyzed. The penumbral brightness can be explained by the energy transfer of the ascending mass carried by the Evershed flow, if the physical quantities below z = -75 km are extrapolated from the results of the inversion.

  3. Performance of ERA-Interim wave data in the nearshore waters around India

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; Naseef, T.M.

    Bulk wave parameters, such as wave height and wave period, are required for engineering and environmental applications. In this study, measured wave data from six shallow-water locations in the data-sparse north Indian Ocean are used to assess...

  4. Simulations of short-crested harbour waves with variational Boussinesq modelling

    NARCIS (Netherlands)

    Adytia, D.

    2014-01-01

    Waves propagating from the deep ocean to the coast show large changes in wave height, wave length and direction. The challenge to simulate the essential wave characteristics is in particular to model the speed and nonlinear interaction correctly. All these physical phenomena are present, but hidden,

  5. Near-Shore Floating Wave Energy Converters

    DEFF Research Database (Denmark)

    Ruol, Piero; Zanuttigh, Barbara; Martinelli, Luca

    2011-01-01

    and transmission characteristics are approximated to functions of wave height, period and obliquity. Their order of magnitude are 20% and 80%, respectively. It is imagined that an array of DEXA is deployed in front of Marina di Ravenna beach (IT), a highly touristic site of the Adriatic Coast. Based on the CERC......Aim of this note is to analyse the possible application of a Wave Energy Converter (WEC) as a combined tool to protect the coast and harvest energy. Physical model tests are used to evaluate wave transmission past a near-shore floating WEC of the wave activated body type, named DEXA. Efficiency...

  6. Calcium waves.

    Science.gov (United States)

    Jaffe, Lionel F

    2008-04-12

    Waves through living systems are best characterized by their speeds at 20 degrees C. These speeds vary from those of calcium action potentials to those of ultraslow ones which move at 1-10 and/or 10-20 nm s(-1). All such waves are known or inferred to be calcium waves. The two classes of calcium waves which include ones with important morphogenetic effects are slow waves that move at 0.2-2 microm s(-1) and ultraslow ones. Both may be propagated by cycles in which the entry of calcium through the plasma membrane induces subsurface contraction. This contraction opens nearby stretch-sensitive calcium channels. Calcium entry through these channels propagates the calcium wave. Many slow waves are seen as waves of indentation. Some are considered to act via cellular peristalsis; for example, those which seem to drive the germ plasm to the vegetal pole of the Xenopus egg. Other good examples of morphogenetic slow waves are ones through fertilizing maize eggs, through developing barnacle eggs and through axolotl embryos during neural induction. Good examples of ultraslow morphogenetic waves are ones during inversion in developing Volvox embryos and across developing Drosophila eye discs. Morphogenetic waves may be best pursued by imaging their calcium with aequorins.

  7. Spatial evolution equation of wind wave growth

    Institute of Scientific and Technical Information of China (English)

    WANG; Wei; (王; 伟); SUN; Fu; (孙; 孚); DAI; Dejun; (戴德君)

    2003-01-01

    Based on the dynamic essence of air-sea interactions, a feedback type of spatial evolution equation is suggested to match reasonably the growing process of wind waves. This simple equation involving the dominant factors of wind wave growth is able to explain the transfer of energy from high to low frequencies without introducing the concept of nonlinear wave-wave interactions, and the results agree well with observations. The rate of wave height growth derived in this dissertation is applicable to both laboratory and open sea, which solidifies the physical basis of using laboratory experiments to investigate the generation of wind waves. Thus the proposed spatial evolution equation provides a new approach for the research on dynamic mechanism of air-sea interactions and wind wave prediction.

  8. Wave turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Nazarenko, Sergey [Warwick Univ., Coventry (United Kingdom). Mathematics Inst.

    2011-07-01

    Wave Turbulence refers to the statistical theory of weakly nonlinear dispersive waves. There is a wide and growing spectrum of physical applications, ranging from sea waves, to plasma waves, to superfluid turbulence, to nonlinear optics and Bose-Einstein condensates. Beyond the fundamentals the book thus also covers new developments such as the interaction of random waves with coherent structures (vortices, solitons, wave breaks), inverse cascades leading to condensation and the transitions between weak and strong turbulence, turbulence intermittency as well as finite system size effects, such as ''frozen'' turbulence, discrete wave resonances and avalanche-type energy cascades. This book is an outgrow of several lectures courses held by the author and, as a result, written and structured rather as a graduate text than a monograph, with many exercises and solutions offered along the way. The present compact description primarily addresses students and non-specialist researchers wishing to enter and work in this field. (orig.)

  9. Linking source region and ocean wave parameters with the observed primary microseismic noise

    Science.gov (United States)

    Juretzek, C.; Hadziioannou, C.

    2017-12-01

    In previous studies, the contribution of Love waves to the primary microseismic noise field was found to be comparable to those of Rayleigh waves. However, so far only few studies analysed both wave types present in this microseismic noise band, which is known to be generated in shallow water and the theoretical understanding has mainly evolved for Rayleigh waves only. Here, we study the relevance of different source region parameters on the observed primary microseismic noise levels of Love and Rayleigh waves simultaneously. By means of beamforming and correlation of seismic noise amplitudes with ocean wave heights in the period band between 12 and 15 s, we analysed how source areas of both wave types compare with each other around Europe. The generation effectivity in different source regions was compared to ocean wave heights, peak ocean gravity wave propagation direction and bathymetry. Observed Love wave noise amplitudes correlate comparably well with near coastal ocean wave parameters as Rayleigh waves. Some coastal regions serve as especially effective sources for one or the other wave type. These coincide not only with locations of high wave heights but also with complex bathymetry. Further, Rayleigh and Love wave noise amplitudes seem to depend equally on the local ocean wave heights, which is an indication for a coupled variation with swell height during the generation of both wave types. However, the wave-type ratio varies directionally. This observation likely hints towards a spatially varying importance of different source mechanisms or structural influences. Further, the wave-type ratio is modulated depending on peak ocean wave propagation directions which could indicate a variation of different source mechanism strengths but also hints towards an imprint of an effective source radiation pattern. This emphasizes that the inclusion of both wave types may provide more constraints for the understanding of acting generation mechanisms.

  10. Three-dimensional freak waves and higher-order wave-wave resonances

    Science.gov (United States)

    Badulin, S. I.; Ivonin, D. V.; Dulov, V. A.

    2012-04-01

    Quite often the freak wave phenomenon is associated with the mechanism of modulational (Benjamin-Feir) instability resulted from resonances of four waves with close directions and scales. This weakly nonlinear model reflects some important features of the phenomenon and is discussing in a great number of studies as initial stage of evolution of essentially nonlinear water waves. Higher-order wave-wave resonances attract incomparably less attention. More complicated mathematics and physics explain this disregard partially only. The true reason is a lack of adequate experimental background for the study of essentially three-dimensional water wave dynamics. We start our study with the classic example of New Year Wave. Two extreme events: the famous wave 26.5 meters and one of smaller 18.5 meters height (formally, not freak) of the same record, are shown to have pronounced features of essentially three-dimensional five-wave resonant interactions. The quasi-spectra approach is used for the data analysis in order to resolve adequately frequencies near the spectral peak fp ≈ 0.057Hz and, thus, to analyze possible modulations of the dominant wave component. In terms of the quasi-spectra the above two anomalous waves show co-existence of the peak harmonic and one at frequency f5w = 3/2fp that corresponds to maximum of five-wave instability of weakly nonlinear waves. No pronounced marks of usually discussed Benjamin-Feir instability are found in the record that is easy to explain: the spectral peak frequency fp corresponds to the non-dimensional depth parameter kD ≈ 0.92 (k - wavenumber, D ≈ 70 meters - depth at the Statoil platform Draupner site) that is well below the shallow water limit of the instability kD = 1.36. A unique data collection of wave records of the Marine Hydrophysical Institute in the Katsiveli platform (Black Sea) has been analyzed in view of the above findings of possible impact of the five-wave instability on freak wave occurrence. The data cover

  11. High Temperature Monitoring the Height of Condensed Water in Steam Pipes

    Science.gov (United States)

    Bar-Cohen, Yoseph; Lih, Shyh-Shiuh; Badescu, Mircea; Bao, Xiaoqi; Sherrit, Stewart; Widholm, Scott; Ostlund, Patrick; Blosiu, Julian

    2011-01-01

    An in-service health monitoring system is needed for steam pipes to track through their wall the condensation of water. The system is required to measure the height of the condensed water inside the pipe while operating at temperatures that are as high as 250 deg. C. The system needs to be able to make real time measurements while accounting for the effects of cavitation and wavy water surface. For this purpose, ultrasonic wave in pulse-echo configuration was used and reflected signals were acquired and auto-correlated to remove noise from the data and determine the water height. Transmitting and receiving the waves is done by piezoelectric transducers having Curie temperature that is significantly higher than 250 deg. C. Measurements were made at temperatures as high as 250 deg. C and have shown the feasibility of the test method. This manuscript reports the results of this feasibility study.

  12. Wave run-up on sandbag slopes

    Directory of Open Access Journals (Sweden)

    Thamnoon Rasmeemasmuang

    2014-03-01

    Full Text Available On occasions, sandbag revetments are temporarily applied to armour sandy beaches from erosion. Nevertheless, an empirical formula to determine the wave run -up height on sandbag slopes has not been available heretofore. In this study a wave run-up formula which considers the roughness of slope surfaces is proposed for the case of sandbag slopes. A series of laboratory experiments on the wave run -up on smooth slopes and sandbag slopes were conducted in a regular-wave flume, leading to the finding of empirical parameters for the formula. The proposed empirical formula is applicable to wave steepness ranging from 0.01 to 0.14 and to the thickness of placed sandbags relative to the wave height ranging from 0.17 to 3.0. The study shows that the wave run-up height computed by the formula for the sandbag slopes is 26-40% lower than that computed by the formula for the smooth slopes.

  13. Wave Overtopping of a Barrier Beach

    Science.gov (United States)

    2009-09-01

    but can result in increased dune erosion along Scenic Road as occurred in 1993, 1997, and 2005 (James, 2005). Field data and observations for...factors are equal to 1. The equations for these run-up formulas are parameterized on significant wave height at the toe of the structure as measured in...3 exp C r SS RQ C D HgH γ ⎛ ⎞ = −⎜ ⎟ ⎝ ⎠ 2pξ > where the significant wave height at the toe of the structure, SH and pT are used. Again the

  14. BOREAS AFM-6 Boundary Layer Height Data

    Science.gov (United States)

    Wilczak, James; Hall, Forrest G. (Editor); Newcomer, Jeffrey A. (Editor); Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Airborne Fluxes and Meteorology (AFM)-6 team from National Oceanic and Atmospheric Adminsitration/Environment Technology Laboratory (NOAA/ETL) operated a 915-MHz wind/Radio Acoustic Sounding System (RASS) profiler system in the Southern Study Area (SSA) near the Old Jack Pine (OJP) site. This data set provides boundary layer height information over the site. The data were collected from 21 May 1994 to 20 Sep 1994 and are stored in tabular ASCII files. The boundary layer height data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  15. Towards worldwide height unification using ocean information

    Directory of Open Access Journals (Sweden)

    P. L. Woodworth

    2015-03-01

    Full Text Available This paper describes how we are contributing to worldwide height system unification (WHSU by using ocean models together with sea level (tide gauge and altimeter information, geodetic (GPS and levelling data, and new geoid models based on information from the GRACE and GOCE gravity missions, to understand how mean sea level (MSL varies from place to place along the coast. For the last two centuries, MSL has been used to define datums for national levelling systems. However, there are many problems with this. One consequence of WHSU will be the substitution of conventional datums as a reference for heights with the use of geoid, as the only true "level" or datum. This work is within a number of GOCE-related activities funded by the European Space Agency. The study is focused on the coastlines of North America and Europe where the various datasets are most copious.

  16. Bringing satellite winds to hub-height

    DEFF Research Database (Denmark)

    Badger, Merete; Pena Diaz, Alfredo; Bredesen, Rolv Erlend

    2012-01-01

    Satellite observations of the ocean surface can provide detailed information about the spatial wind variability over large areas. This is very valuable for the mapping of wind resources offshore where other measurements are costly and sparse. Satellite sensors operating at microwave frequencies...... measure the amount of radar backscatter from the sea surface, which is a function of the instant wind speed, wind direction, and satellite viewing geometry. A major limitation related to wind retrievals from satellite observations is that existing empirical model functions relate the radar backscatter...... to wind speed at the height 10 m only. The extrapolation of satellite wind fields to higher heights, which are more relevant for wind energy, remains a challenge which cannot be addressed by means of satellite data alone. As part of the EU-NORSEWInD project (2008-12), a hybrid method has been developed...

  17. Height predicts jealousy differently for men and women

    NARCIS (Netherlands)

    Buunk, Abraham P.; Park, Justin H.; Zurriaga, Rosario; Klavina, Liga; Massar, Karlijn

    Because male height is associated with attractiveness, dominance, and reproductive success, taller men may be less jealous. And because female height has a curvilinear relationship with health and reproductive success (with average-height females having the advantages), female height may have a

  18. Lucas Heights buffer zone: plan of management

    International Nuclear Information System (INIS)

    1986-01-01

    This plan is being used by the Commission as a guide for its management of the Lucas Heights buffer zone, which is essentially a circular area having a 1-6 km radius around the HIFAR reactor. Aspects covered by this plan include past uses, current use, objectives for buffer zone land management, emergency evacuation, resource conservation, archaeology, fire, access, rehabilitation of disturbed areas, resource management and plan implementation

  19. Weight and height prediction of immobilized patients

    OpenAIRE

    Rabito,Estela Iraci; Vannucchi,Gabriela Bergamini; Suen,Vivian Marques Miguel; Castilho Neto,Laércio Lopes; Marchini,Júlio Sérgio

    2006-01-01

    OBJECTIVE: To confirm the adequacy of the formula suggested in the literature and/or to develop appropriate equations for the Brazilian population of immobilized patients based on simple anthropometric measurements. METHODS: Hospitalized patients were submitted to anthropometry and methods to estimate weight and height of bedridden patients were developed by multiple linear regression. RESULTS: Three hundred sixty eight persons were evaluated at two hospital centers and five weight-predicting...

  20. Gravity and Height Variations at Medicina, Italy

    Science.gov (United States)

    Bruni, Sara; Zerbini, Susanna; Errico, Maddalena; Santi, Efisio; Wziontek, Hartmut

    2017-04-01

    Since 1996, at the Medicina station, height and gravity variations are monitored continuously by means of GPS, VLBI and superconducting gravimeter (SG) data. Additionally, absolute gravity observations are performed twice a year and environmental parameters, among others water table levels, are regularly acquired. Levelling between the different monuments at the site area is also carried out repeatedly to constrain local ties in the vertical position. Two GPS systems are located very close to each other, and both are in close proximity to the VLBI antenna. Twenty years of data are now available, which allow investigating both long- and short-period height and gravity signals together with their relevant correlations. Natural land subsidence, which is well known to occur in the area, is a major component of the observed long-term behavior; however, non-linear long-period signatures are also present in the time series. On a shorter time scale, fingerprints of the water table seasonal oscillations can be recognized in the data. The Medicina site is characterized by clayey soil subjected to consolidation effects when the water table lowers during summer periods. The pillar on which the SG is installed is especially affected because of its shallow foundation, causing height decreases in the order of 2.5-3 cm for water table lowering of 2 m. This study presents a comparative analysis of the different data sets with the aim of separating mass and deformation contributions in the SG gravity record.

  1. A global boundary-layer height climatology

    Energy Technology Data Exchange (ETDEWEB)

    Dop, H. van; Krol, M.; Holtslag, B. [Inst. for Marine and Atmospheric Research Utrecht, IMAU, Utrecht (Netherlands)

    1997-10-01

    In principle the ABL (atmospheric boundary layer) height can be retrieved from atmospheric global circulation models since they contain algorithms which determine the intensity of the turbulence as a function of height. However, these data are not routinely available, or on a (vertical) resolution which is too crude in view of the application. This justifies the development of a separate algorithm in order to define the ABL. The algorithm should include the generation of turbulence by both shear and buoyancy and should be based on readily available atmospheric parameters. There is obviously a wide application for boundary heights in off-line global and regional chemistry and transport modelling. It is also a much used parameter in air pollution meteorology. In this article we shall present a theory which is based on current insights in ABL dynamics. The theory is applicable over land and sea surfaces in all seasons. The theory is (for various reasons) not valid in mountainous areas. In areas where boundary-layer clouds or deep cumulus convection are present the theory does not apply. However, the same global atmospheric circulation models contain parameterizations for shallow and deep convection from which separate estimates can be obtained for the extent of vertical mixing. (au)

  2. Application of CFD based wave loads in aeroelastic calculations

    DEFF Research Database (Denmark)

    Schløer, Signe; Paulsen, Bo Terp; Bredmose, Henrik

    2014-01-01

    Two fully nonlinear irregular wave realizations with different significant wave heights are considered. The wave realizations are both calculated in the potential flow solver Ocean-Wave3D and in a coupled domain decomposed potential-flow CFD solver. The surface elevations of the calculated wave...... domain decomposed potentialflow CFD solver result in different dynamic forces in the tower and monopile, despite that the static forces on a fixed monopile are similar. The changes are due to differences in the force profiles and wave steepness in the two solvers. The results indicate that an accurate...

  3. Degeneration and height of cervical discs classified from MRI compared with precise height measurements from radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Kolstad, Frode [National Centre of Spinal Disorders, Norwegian University of Science and Technology, University Hospital of Trondheim, 7006 Trondheim (Norway)]. E-mail: frode.kolstad@medisin.ntnu.no; Myhr, Gunnar [Department of Radiology, University Hospital of Trondheim, 7006 Trondheim (Norway); Kvistad, Kjell Arne [Department of Radiology, University Hospital of Trondheim, 7006 Trondheim (Norway); Nygaard, Oystein P. [National Centre of Spinal Disorders, Norwegian University of Science and Technology, University Hospital of Trondheim, 7006 Trondheim (Norway); Leivseth, Gunnar [Department of Neuromedicine, Faculty of Medicine, Norwegian University of Science and Technology, University Hospital of Trondheim, 7006 Trondheim (Norway)

    2005-09-01

    Study design: Descriptive study comparing MRI classifications with measurements from radiographs. Objectives: 1.Define the relationship between MRI classified cervical disc degeneration and objectively measured disc height. 2.Assess the level of inter- and intra-observer errors using MRI in defining cervical disc degeneration. Summary of background data: Cervical spine degeneration has been defined radiologically by loss of disc height, decreased disc and bone marrow signal intensity and disc protrusion/herniation on MRI. The intra- and inter-observer error using MRI in defining cervical degeneration influences data interpretation. Few previous studies have addressed this source of error. The relation and time sequence between cervical disc degeneration classified by MRI and cervical disc height decrease measured from radiographs is unclear. Methods: The MRI classification of degeneration was based on nucleus signal, prolaps identification and bone marrow signal. Two neuro-radiologists evaluated the MR-images independently in a blinded fashion. The radiographic disc height measurements were done by a new computer-assisted method compensating for image distortion and permitting comparison with normal level-, age- and gender-appropriate disc height. Results/conclusions: 1.Progressing disc degeneration classified from MRI is on average significantly associated with a decrease of disc height as measured from radiographs. Within each MRI defined category of degeneration measured disc heights, however, scatter in a wide range. 2.The inter-observer agreement between two neuro-radiologists in both defining degeneration and disc height by MRI was only moderate. Studies addressing questions related to cervical disc degeneration should take this into consideration.

  4. Degeneration and height of cervical discs classified from MRI compared with precise height measurements from radiographs

    International Nuclear Information System (INIS)

    Kolstad, Frode; Myhr, Gunnar; Kvistad, Kjell Arne; Nygaard, Oystein P.; Leivseth, Gunnar

    2005-01-01

    Study design: Descriptive study comparing MRI classifications with measurements from radiographs. Objectives: 1.Define the relationship between MRI classified cervical disc degeneration and objectively measured disc height. 2.Assess the level of inter- and intra-observer errors using MRI in defining cervical disc degeneration. Summary of background data: Cervical spine degeneration has been defined radiologically by loss of disc height, decreased disc and bone marrow signal intensity and disc protrusion/herniation on MRI. The intra- and inter-observer error using MRI in defining cervical degeneration influences data interpretation. Few previous studies have addressed this source of error. The relation and time sequence between cervical disc degeneration classified by MRI and cervical disc height decrease measured from radiographs is unclear. Methods: The MRI classification of degeneration was based on nucleus signal, prolaps identification and bone marrow signal. Two neuro-radiologists evaluated the MR-images independently in a blinded fashion. The radiographic disc height measurements were done by a new computer-assisted method compensating for image distortion and permitting comparison with normal level-, age- and gender-appropriate disc height. Results/conclusions: 1.Progressing disc degeneration classified from MRI is on average significantly associated with a decrease of disc height as measured from radiographs. Within each MRI defined category of degeneration measured disc heights, however, scatter in a wide range. 2.The inter-observer agreement between two neuro-radiologists in both defining degeneration and disc height by MRI was only moderate. Studies addressing questions related to cervical disc degeneration should take this into consideration

  5. Gravitation Waves

    CERN Multimedia

    CERN. Geneva

    2005-01-01

    We will present a brief introduction to the physics of gravitational waves and their properties. We will review potential astrophysical sources of gravitational waves, and the physics and astrophysics that can be learned from their study. We will survey the techniques and technologies for detecting gravitational waves for the first time, including bar detectors and broadband interferometers, and give a brief status report on the international search effort, with special emphasis on the LIGO detectors and search results.

  6. Waves in separated two-phase flow

    International Nuclear Information System (INIS)

    Pols, R.M.

    1998-06-01

    This dissertation presents an integral approach to the modelling of co-current flow of liquid and gas for a class of non-linear wave problems. Typically the liquid phase and the gas phase are decoupled and the liquid is depth averaged. The resulting non-linear shallow water equations are solved to predict the behaviour of the finite amplitude waves. The integral approach is applied to the modelling of two-dimensional waves in a horizontal and slightly inclined rectangular channel, two-dimensional waves in a vertical pipe and three-dimensional waves in a horizontal tube. For flow in a horizontal or slightly inclined channel the liquid is driven by the interfacial shear from the gas phase and the surface is subject to extensive wave action. For thin liquid films the pressure in the liquid may be taken as hydrostatic and gravity acts as a restoring force on the liquid. Roll wave solutions to the non-linear shallow water equations are sought corresponding to an interfacial shear stress dependent on the liquid film height. Wave solutions are shown to exist but only for parameters within a defined range dependent on the channel inclination, interfacial roughness and linear dependence on the liquid film height of the shear stresses. Such solutions are discontinuous and are pieced together by a jump where mass and momentum are conserved. The model calculations on wave height and wave velocity are compared with experimental data. The essentially two-dimensional analysis developed for stratified horizontal flow can be extended to quasi three-dimensional flow in the case of shallow liquid depth for a circular pipe. In this case the liquid depth changes with circumferential position and consequently modifies the interfacial shear exerted on the liquid surface creating a wave spreading mechanism alongside changing the wave profile across the pipe. The wave spreading mechanism supposes a wave moving in axial direction at a velocity faster than the liquid thereby sweeping liquid

  7. Monstrous ocean waves during typhoon Krosa

    Directory of Open Access Journals (Sweden)

    P. C. Liu

    2008-06-01

    Full Text Available This paper presents a set of ocean wave time series data recorded from a discus buoy deployed near northeast Taiwan in western Pacific that was operating during the passage of Typhoon Krosa on 6 October 2007. The maximum trough-to-crest wave height was measured to be 32.3 m, which could be the largest Hmax ever recorded.

  8. Long-term statistics of extreme tsunami height at Crescent City

    Science.gov (United States)

    Dong, Sheng; Zhai, Jinjin; Tao, Shanshan

    2017-06-01

    Historically, Crescent City is one of the most vulnerable communities impacted by tsunamis along the west coast of the United States, largely attributed to its offshore geography. Trans-ocean tsunamis usually produce large wave runup at Crescent Harbor resulting in catastrophic damages, property loss and human death. How to determine the return values of tsunami height using relatively short-term observation data is of great significance to assess the tsunami hazards and improve engineering design along the coast of Crescent City. In the present study, the extreme tsunami heights observed along the coast of Crescent City from 1938 to 2015 are fitted using six different probabilistic distributions, namely, the Gumbel distribution, the Weibull distribution, the maximum entropy distribution, the lognormal distribution, the generalized extreme value distribution and the generalized Pareto distribution. The maximum likelihood method is applied to estimate the parameters of all above distributions. Both Kolmogorov-Smirnov test and root mean square error method are utilized for goodness-of-fit test and the better fitting distribution is selected. Assuming that the occurrence frequency of tsunami in each year follows the Poisson distribution, the Poisson compound extreme value distribution can be used to fit the annual maximum tsunami amplitude, and then the point and interval estimations of return tsunami heights are calculated for structural design. The results show that the Poisson compound extreme value distribution fits tsunami heights very well and is suitable to determine the return tsunami heights for coastal disaster prevention.

  9. VHF radar observations of gravity waves at a low latitude

    Directory of Open Access Journals (Sweden)

    G. Dutta

    1999-08-01

    Full Text Available Wind observations made at Gadanki (13.5°N by using Indian MST Radar for few days in September, October, December 1995 and January, 1996 have been analyzed to study gravity wave activity in the troposphere and lower stratosphere. Horizontal wind variances have been computed for gravity waves of period (2-6 h from the power spectral density (PSD spectrum. Exponential curves of the form eZ/H have been fitted by least squares technique to these variance values to obtain height variations of the irregular winds upto the height of about 15 km, where Z is the height in kilometers. The value of H, the scale height, as determined from curve fitting is found to be less than the theoretical value of scale height of neutral atmosphere in this region, implying that the waves are gaining energy during their passage in the troposphere. In other words, it indicates that the sources of gravity waves are present in the troposphere. The energy densities of gravity wave fluctuations have been computed. Polynomial fits to the observed values show that wave energy density increases in the troposphere, its source region, and then decreases in the lower stratosphere.Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; turbulence; waves and tides

  10. Moreton wave, "EIT wave", and type II radio burst as manifestations of a single wave front

    Science.gov (United States)

    Kuzmenko, I. V.; Grechnev, V. V.; Uralov, A. M.

    2011-12-01

    We show that a Moreton wave, an "EIT wave," and a type II radio burst observed during a solar flare of July 13, 2004, might have been a manifestation of a single front of a decelerating shock wave, which appeared in an active region (AR) during a filament eruption. We propose describing a quasi-spheroidal wave propagating upward and along the solar surface by using relations known from a theory of a point-like explosion in a gas whose density changes along the radius according to a power law. By applying this law to fit the drop in density of the coronal plasma enveloping the solar active region, we first managed to bring the measured positions and velocities of surface Moreton wave and "EIT wave" into correspondence with the observed frequency drift rate of the meter type II radio burst. The exponent of the vertical coronal density falloff is selected by fitting the power law to the Newkirk and Saito empirical distributions in the height range of interest. Formal use of such a dependence in the horizontal direction with a different exponent appears to be reasonable up to distances of less than 200 Mm around the eruption center. It is possible to assume that the near-surface shock wave weakens when leaving this radius and finally the active region, entering the region of the quiet Sun where the coronal plasma density and the fast-mode speed are almost constant along the horizontal.

  11. Plasma waves

    National Research Council Canada - National Science Library

    Swanson, D. G

    1989-01-01

    ... Swanson, D.G. (Donald Gary), D a t e - Plasma waves. Bibliography: p. Includes index. 1. Plasma waves. QC718.5.W3S43 1989 ISBN 0-12-678955-X I. Title. 530.4'4 88-34388 Printed in the United Sta...

  12. Wave Dragon

    DEFF Research Database (Denmark)

    Tedd, James; Kofoed, Jens Peter; Friis-Madsen, Erik

    2008-01-01

    Since March 2003 a prototype of Wave Dragon has been tested in an inland sea in Denmark. This has been a great success with all subsystems tested and improved through working in an offshore environment. The project has proved the Wave Dragon device and has enabled the next stage, a production sized...

  13. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Brorsen, Michael; Frigaard, Peter

    Nærværende rapport beskriver numeriske beregninger af den hydrodynamiske interaktion mellem 5 flydere i bølgeenergianlægget Wave Star.......Nærværende rapport beskriver numeriske beregninger af den hydrodynamiske interaktion mellem 5 flydere i bølgeenergianlægget Wave Star....

  14. Phase height measurements on the ionosphere

    International Nuclear Information System (INIS)

    Joyner, K.H.

    1974-01-01

    Phase height measurements have been taken on 2.5 MHz E-region reflection over two paths during the day. The two paths have equivalent vertical frequencies of 2.4 MHz and 1.8 MHz. Vertical pulse measurements on 2.4 MHz have also been recorded. Results and discussion on comparisons between these measurements are presented. Phase and amplitude measurements using 4.5 MHz O and E rays have also been taken at night, F-region reflection. In particular, spectral analysis of these results is discussed. (author)

  15. Boundary layer heights derived from velocity spectra

    Energy Technology Data Exchange (ETDEWEB)

    Hoejstrup, J.; Barthelmie, R.J. [Risoe National Lab., Roskilde (Denmark); Kaellstrand, B. [Univ. of Uppsala, Uppsala (Sweden)

    1997-10-01

    It is a well-known fact that the height of the mixed layer determines the size of the largest and most energetic eddies that can be observed in the unstable boundary layer, and consequently a peak can be observed in the power spectra of the along-wind velocity component at scales comparable to the mixed layer depth. We will now show how the mixed layer depth can be derived from the u-specta and the results will be compared with direct measurements using pibal and tethersonde measurements. (au)

  16. Patella height changes post high tibial osteotomy

    Directory of Open Access Journals (Sweden)

    Siew Ghim Gooi

    2017-01-01

    Full Text Available Background: Medial opening wedge high tibial osteotomy (HTO is a well-described treatment in early medial compartmental osteoarthritis of the knee. However, two undesirable sequelae may follow –patella baja and changes in the posterior tibial slope (TS. Materials and Methods: We conducted a retrospective study in patients who underwent HTO in our center between September 2009 and February 2017. Preoperative and 6-week postoperative long-leg weight bearing films and lateral knee radiographs were assessed. Pre- and postoperative radiological measurements include the Caton-Deschamps Index (CDI, the mechanical axis deviation (MAD, and the posterior TS. Independant t-test and Pearson correlation test were performed. Results: A total of 106 knees were recruited. The mean age was 48.8 ± 10.8 years. 66 (62.3% and 40 (37.7% knees were from males and females, respectively. The mean pre- and postoperative measurements was (−9.70° ± 3.67° to 0.08° ± 2.80° (−varus; +valgus for the MAD, (7.14° ± 1.78° to 8.72° ± 3.11° for posterior TS, and (0.93° ± 0.084° to 0.82° ± 0.13° for CDI (P ≤ 0.001 for all. The association between patella height change and the level of osteotomy (supra-tubercle vs. infra-tubercle was statistically significant (P < 0.001. A supra-tubercle osteotomy cut significantly lowering patella height (P = 0.011. There was otherwise no statistically significant correlations between patella height changes and the correction angle (P = 0.187 or posterior TS change (P = 0.744. Conclusions: A medial opening wedge HTO above the tibial tubercle was significantly associated with lowering patella height or reducing CDI postoperatively. Based on our results, we would recommend the use of an infra-tubercle osteotomy during the corrective surgery to prevent the complication of patella baja.

  17. Characteristics of offshore extreme wind-waves detected by surface drifters with a low-cost GPS wave sensor

    Science.gov (United States)

    Komatsu, Kosei

    Wind-generated waves have been recognized as one of the most important factors of the sea surface roughness which plays crucial roles in various air-sea interactions such as energy, mo-mentum, heat and gas exchanges. At the same time, wind waves with extreme wave heights representatively called as freak or rogue waves have been a matter of great concern for many people involved in shipping, fishing, constracting, surfing and other marine activities, because such extreme waves frequently affect on the marine activities and sometimes cause serious dis-asters. Nevertheless, investigations of actual conditions for the evolution of wind waves in the offshore region are less and sparse in contrast to dense monitoring networks in the coastal re-gions because of difficulty of offshore observation with high accuracy. Recently accurate in situ observation of offshore wind waves is getting possible at low cost owing to a wave height and di-rection sensor developed by Harigae et al. (2004) by installing a point-positioning GPS receiver on a surface drifting buoy. The point-positioning GPS sensor can extract three dimensional movements of the buoy excited by ocean waves with minimizing effects of GPS point-positioning errors through the use of a high-pass filter. Two drifting buoys equipped with the GPS-based wave sensor charged by solar cells were drifted in the western North Pacific and one of them continued to observe wind waves during 16 months from Sep. 2007. The RMSE of the GPS-based wave sensor was less than 10cm in significant wave height and about 1s in significant wave period in comparison with other sensors, i.e. accelerometers installed on drifting buoys of Japan Meteorological Agency, ultrasonic sensors placed at the Hiratsuka observation station of the University of Tokyo and altimeter of the JASON-1. The GPS-based wave buoys enabled us to detect freak waves defined as waves whose height is more than twice the significant wave height. The observation conducted by

  18. Development of a pulse height analizer

    International Nuclear Information System (INIS)

    Moreira, E.S.

    1984-01-01

    The development of a Pulse Height Analizer is described. This equipment is essential to analize data coming from detectors producing information codified in pulse amplitudes. The system developed consist of a Signal Input Module connected to a Controller Module based on a 8085A microprocessor capable to memorize pulses up to 1 uS in 256 channels with a resolution better than 20 mV. A Communication Module with a serial interface is used for data transfer to a host computer using RS232c protocol. The Monitoring and Operation Module consist of a hexadecimal Keybord, a 6 digit 7-segment display and a XY analog output enabling real time visualization of data on a XY monitor. The hardware and the software designed for this low cost system were optimized to obtain a typical dead time of approximately 100 uS. As application, this device was used to adquire curves at the Small Angle X-ray Scattering Laboratory in this Department. The apparatus performance was tested by comparing its data with a Northern Pulse Height Analizer model NS633 output, with favorable results. (Author) [pt

  19. A Stream Function Theory Based Calculation of Wave Kinematics for Very Steep Waves Using a Novel Non-linear Stretching Technique

    DEFF Research Database (Denmark)

    Stroescu, Ionut Emanuel; Sørensen, Lasse; Frigaard, Peter Bak

    2016-01-01

    A non-linear stretching method was implemented for stream function theory to solve wave kinematics for physical conditions close to breaking waves in shallow waters, with wave heights limited by the water depth. The non-linear stretching method proves itself robust, efficient and fast, showing good...

  20. Low-cost wave characterization modules for oil spill response

    Directory of Open Access Journals (Sweden)

    E.D. Skinner

    2018-06-01

    Full Text Available Marine oil spills can be remediated by mechanical skimmers in calm waters, but performance degrades with increased wave height. We have developed and demonstrated a system that quantifies local wave characteristics with an uncertainty of four inches of heave. Our system is intended for the measurement of wave characteristics during oil spill recovery. It conveys this information to coordinators and responders in real time via WiFi and remote reporting through a satellite network. This information will allow for enhanced situational awareness during an oil spill response, assisting stakeholders and optimizing mechanical skimming operations. Our wave characterization module (WCM uses accelerometer outputs from a very small inertial measurement unit (IMU to generate wave statistics and calculate wave characteristics. It is configured such that a WCM can either be attached to a skimmer float or incorporated into a microbuoy. Wave height and period are transmitted via WiFi and/or a satellite-enabled mesh-grid network to a cloud-hosted geographic information system (GIS. Here, we discuss the bare-bones sensors-plus-algorithm approach we developed by using spring-mass systems to approximate the wave height and period regime of interest. We then describe open water tests carried out using that development system both mounted to a weir skimmer mockup and packaged in a microbuoy. Finally, we present controlled tests in the wave tank at Ohmsett, the National Oil Spill Response Test Facility in New Jersey, with the WCMs communicating the wave characteristics via WiFi to tankside laptops and via satellite to the cloud-based GIS. Snapshot determinations of wave height calculated using the scalar magnitude of the three-axis accelerometer in the IMU were within four inches of the benchmark wave measurement system at Ohmsett. Keywords: Oil spill, Wave characterization module, Inertial measurement unit, Microbuoy

  1. Ocean wave characteristic in the Sunda Strait using Wave Spectrum Model

    Science.gov (United States)

    Rachmayani, R.; Ningsih, N. S.; Adiprabowo, S. R.; Nurfitri, S.

    2018-03-01

    The wave characteristics including significant wave height and direction, seas and swell in the Sunda Strait are analyzed seasonally to provide marine weather information. This is crucial for establishing secured marine activities between islands of Sumatera and Java. Ocean wave characteristics in the Sunda Strait are simulated for one year (July 1996–June 1977) by using SWAN numerical model. The ocean wave characteristics in the Sunda Strait are divided into three areas of interest; southern, centre and northern part of the Sunda Strait. Despite a weaker local wind, the maximum significant wave height is captured at the southern part with its height of 2.6 m in November compared to other seasonally months. This is associated with the dominated swell from the Indian Ocean contributes on wave energy toward the Sunda Strait. The 2D spectrum analysis exhibits the monthly wave characteristic at southern part that is dominated by seas along the year and swell propagating from the Indian Ocean to the Sunda Strait during December to February (northwest monsoon), May, and November. Seas and swell at northern part of the Sunda Strait are apprehended weaker compared to other parts of the Sunda Strait due to its location is farther from the Indian Ocean.

  2. Quasitravelling waves

    International Nuclear Information System (INIS)

    Beklaryan, Leva A

    2011-01-01

    A finite difference analogue of the wave equation with potential perturbation is investigated, which simulates the behaviour of an infinite rod under the action of an external longitudinal force field. For a homogeneous rod, describing solutions of travelling wave type is equivalent to describing the full space of classical solutions to an induced one-parameter family of functional differential equations of point type, with the characteristic of the travelling wave as parameter. For an inhomogeneous rod, the space of solutions of travelling wave type is trivial, and their 'proper' extension is defined as solutions of 'quasitravelling' wave type. By contrast to the case of a homogeneous rod, describing the solutions of quasitravelling wave type is equivalent to describing the quotient of the full space of impulsive solutions to an induced one-parameter family of point-type functional differential equations by an equivalence relation connected with the definition of solutions of quasitravelling wave type. Stability of stationary solutions is analyzed. Bibliography: 9 titles.

  3. Tsunami Wave Run-up on a Vertical Wall in Tidal Environment

    Science.gov (United States)

    Didenkulova, Ira; Pelinovsky, Efim

    2018-04-01

    We solve analytically a nonlinear problem of shallow water theory for the tsunami wave run-up on a vertical wall in tidal environment. Shown that the tide can be considered static in the process of tsunami wave run-up. In this approximation, it is possible to obtain the exact solution for the run-up height as a function of the incident wave height. This allows us to investigate the tide influence on the run-up characteristics.

  4. Systems and methods for wave energy conversion

    Science.gov (United States)

    MacDonald, Daniel G.; Cantara, Justin; Nathan, Craig; Lopes, Amy M.; Green, Brandon E.

    2017-02-28

    Systems for wave energy conversion that have components that can survive the harsh marine environment and that can be attached to fixed structures, such as a pier, and having the ability to naturally adjust for tidal height and methods for their use are presented.

  5. Wave transmission by suspended pipe breakwater

    Digital Repository Service at National Institute of Oceanography (India)

    Mani, J.S.; Jayakumar, S.

    ratio of 0.46), a 5% reduction in incident-wave height can be achieved. The cost and performance of conventionally adopted pile breakwater (involving a row of closely spaced piles driven on the seabed) were compared with the present system...

  6. Experimental Study on the Langlee Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Weisz, A.

    This report presents the results of an experimental study of the wave energy converting abilities of the Langlee wave energy converter (WEC). It focused mainly on evaluating the power generating capabilities of the device, including investigations of the following issues: Scaling ratiosPTO loadingWave...... height and wave period dependencyOblique incoming waves and directional spreading of waves (3D waves)Damping platesMooring forces and fixed structure setupPitch, surge and heave motion During the study the model supplied by the client (Langlee Wave Power AS) has been heavily instrumented - up to 23...... different instruments was deployed to measure and record data. Tests were performed at scales of 1:30 and 1:20 based on the realized reference wave states....

  7. On the Flame Height Definition for Upward Flame Spread

    OpenAIRE

    Consalvi, Jean L; Pizzo, Yannick; Porterie, Bernard; Torero, Jose L

    2007-01-01

    Flame height is defined by the experimentalists as the average position of the luminous flame and, consequently is not directly linked with a quantitative value of a physical parameter. To determine flame heights from both numerical and theoretical results, a more quantifiable criterion is needed to define flame heights and must be in agreement with the experiments to allow comparisons. For wall flames, steady wall flame experiments revealed that flame height may be define...

  8. On the Predictability of Hub Height Winds

    DEFF Research Database (Denmark)

    Draxl, Caroline

    Wind energy is a major source of power in over 70 countries across the world, and the worldwide share of wind energy in electricity consumption is growing. The introduction of signicant amounts of wind energy into power systems makes accurate wind forecasting a crucial element of modern electrical...... grids. These systems require forecasts with temporal scales of tens of minutes to a few days in advance at wind farm locations. Traditionally these forecasts predict the wind at turbine hub heights; this information is then converted by transmission system operators and energy companies into predictions...... of power output at wind farms. Since the power available in the wind is proportional to the wind speed cubed, even small wind forecast errors result in large power prediction errors. Accurate wind forecasts are worth billions of dollars annually; forecast improvements will result in reduced costs...

  9. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Frigaard, Peter

    Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Byggeri og Anlæg med bølgeenergianlæget Wave Star.......Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Byggeri og Anlæg med bølgeenergianlæget Wave Star....

  10. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Andersen, Thomas Lykke

    Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star.......Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star....

  11. Dominant height-based height-diameter equations for trees in southern Indiana

    Science.gov (United States)

    John A., Jr. Kershaw; Robert C. Morrissey; Douglass F. Jacobs; John R. Seifert; James B. McCarter

    2008-01-01

    Height-diameter equations are developed based on dominant tree data collected in 1986 in 8- to 17-year-old clearcuts and the phase 2 Forest Inventory and Analysis plots on the Hoosier National Forest in south central Indiana. Two equation forms are explored: the basic, three-parameter Chapman-Richards function, and a modification of the three-parameter equation...

  12. Wave Dragon

    DEFF Research Database (Denmark)

    Tedd, James; Kofoed, Jens Peter; Knapp, W.

    2006-01-01

    Wave Dragon is a floating wave energy converter working by extracting energy principally by means of overtopping of waves into a reservoir. A 1:4.5 scale prototype has been sea tested for 20 months. This paper presents results from testing, experiences gained and developments made during this ext......Wave Dragon is a floating wave energy converter working by extracting energy principally by means of overtopping of waves into a reservoir. A 1:4.5 scale prototype has been sea tested for 20 months. This paper presents results from testing, experiences gained and developments made during...... this extended period. The prototype is highly instrumented. The overtopping characteristic and the power produced are presented here. This has enabled comparison between the prototype and earlier results from both laboratory model and computer simulation. This gives the optimal operating point and the expected...... power of the device. The project development team has gained much soft experience from working in the harsh offshore environment. In particular the effect of marine growth in the draft tubes of the turbines has been investigated. The control of the device has been a focus for development as is operates...

  13. Agreement between estimated and measured heights and weights ...

    African Journals Online (AJOL)

    index (BMI = kg/m2) and require accurate recording of a patient's height and weight.1. In reality, however, patients often cannot stand up straight for accurate height measurement, or are unable to step on a scale. In such cases, height and weight values are often obtained from the patient or their relatives, who either do not ...

  14. Anterior Face Height Values in a Nigerian Population | Folaranmi ...

    African Journals Online (AJOL)

    ... Anterior Upper Face Height 47.7 (4) mm, Anterior Total Face Height (ATFH) 108.5 (5) mm, ratio of ALFH to ATFH ALFH: ATFH 56 (4)%. Conclusion: This study provides anterior face height measurements, which will be of great significance in evaluating facial proportions andesthetics in orthodontics, orthognathic surgery, ...

  15. Relationships between diameter and height of trees in natural ...

    African Journals Online (AJOL)

    Relationships between diameter and height of trees in natural tropical forest in Tanzania. Wilson A Mugasha, Ole M Bollandsås, Tron Eid. Abstract. The relationship between tree height (h) and tree diameter at breast height (dbh) is an important element describing forest stands. In addition, h often is a required variable in ...

  16. Estimation of Total Tree Height from Renewable Resources Evaluation Data

    Science.gov (United States)

    Charles E. Thomas

    1981-01-01

    Many ecological, biological, and genetic studies use the measurement of total tree height. Until recently, the Southern Forest Experiment Station's inventory procedures through Renewable Resources Evaluation (RRE) have not included total height measurements. This note provides equations to estimate total height based on other RRE measurements.

  17. The Sine Method: An Alternative Height Measurement Technique

    Science.gov (United States)

    Don C. Bragg; Lee E. Frelich; Robert T. Leverett; Will Blozan; Dale J. Luthringer

    2011-01-01

    Height is one of the most important dimensions of trees, but few observers are fully aware of the consequences of the misapplication of conventional height measurement techniques. A new approach, the sine method, can improve height measurement by being less sensitive to the requirements of conventional techniques (similar triangles and the tangent method). We studied...

  18. Practical application of the geometric geoid for heighting over ...

    African Journals Online (AJOL)

    This is because a geoid model is required to convert ellipsoidal heights to orthometric heights that are used in practice. A local geometric geoid ... The geoid height is expressed as a function of the local plane coordinates through a biquadratic surface polynomial, using 14 GPS/levelling points. Five points have been used ...

  19. 14 CFR 27.87 - Height-speed envelope.

    Science.gov (United States)

    2010-01-01

    ... applicable power failure condition in paragraph (b) of this section, a limiting height-speed envelope must be... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Height-speed envelope. 27.87 Section 27.87... STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Performance § 27.87 Height-speed envelope. (a) If there is any...

  20. 14 CFR 29.1517 - Limiting height-speed envelope.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Limiting height-speed envelope. 29.1517... Operating Limitations § 29.1517 Limiting height-speed envelope. For Category A rotorcraft, if a range of... following power failure, the range of heights and its variation with forward speed must be established...

  1. 14 CFR 29.87 - Height-velocity envelope.

    Science.gov (United States)

    2010-01-01

    ... Category A engine isolation requirements, the height-velocity envelope for complete power failure must be... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Height-velocity envelope. 29.87 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.87 Height-velocity envelope. (a...

  2. Swell-generated Set-up and Infragravity Wave Propagation Over a Fringing Coral Reef: Implications for Wave-driven Inundation of Atoll Islands

    Science.gov (United States)

    Cheriton, O. M.; Storlazzi, C. D.; Rosenberger, K. J.; Quataert, E.; van Dongeren, A.

    2014-12-01

    The Republic of the Marshall Islands is comprised of 1156 islands on 29 low-lying atolls with a mean elevation of 2 m that are susceptible to sea-level rise and often subjected to overwash during large wave events. A 6-month deployment of wave and tide gauges across two shore-normal sections of north-facing coral reef on the Roi-Namur Island on Kwajalein Atoll was conducted during 2013-2014 to quantify wave dynamics and wave-driven water levels on the fringing coral reef. Wave heights and periods on the reef flat were strongly correlated to the water levels. On the fore reef, the majority of wave energy was concentrated in the incident band (5-25 s); due to breaking at the reef crest, however, the wave energy over the reef flat was dominated by infragravity-band (25-250 s) motions. Two large wave events with heights of 6-8 m at 15 s over the fore reef were observed. During these events, infragravity-band wave heights exceeded the incident band wave heights and approximately 1.0 m of set-up was established over the innermost reef flat. This set-up enabled the propagation of large waves across the reef flat, reaching maximum heights of nearly 2 m on the innermost reef flat adjacent to the toe of the beach. XBEACH models of the instrument transects were able to replicate the incident waves, infragravity waves, and wave-driven set-up across the reef when the hydrodynamic roughness of the reef was correctly parameterized. These events led to more than 3 m of wave-driven run-up and inundation of the island that drove substantial morphological change to the beach face.

  3. Wave characteristics off Visakhapatnam coast during a cyclone

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; AshokKumar, K.; Raju, N.S.N.

    CURRENT SCIENC E, VOL. 86, NO. 11, 10 JUNE 2004 *For correspondence. (e - mail: sanil@darya.nio.org) Wave characteristics off Visakhapatnam coast du r ing a cyclone V. Sanil Kumar*, K. Ashok Kumar and N. S. N. Raju Ocean Engineering Division.... Wave period The variation of average wave period ( T 02 ), period corr e- sponding to maximum wave height ( T H max ) and wave p e- riod corresponding to maximum spectral energy ( T p ) during the observation period are shown in Figure 4. Du r- i ng...

  4. Landward Distribution of Wave Overtopping for Rubble Mound Breakwaters

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Burcharth, Hans F.

    2006-01-01

    Overtopping data from seven model test projects has been analyzed with respect to the landward spatial distribution of the overtopping discharge. In total more than 1000 overtopping tests have been analysed and a formula derived for prediction of the landward distribution of overtopping behind...... rubble mound structures with a super structure. The analysis led to the conclusion that although the overtopping discharge, for identical wave heights, decreases with increasing wave steepness, then the maximum travel distance increases with increasing wave steepness....

  5. Ocean Wave Simulation Based on Wind Field.

    Directory of Open Access Journals (Sweden)

    Zhongyi Li

    Full Text Available Ocean wave simulation has a wide range of applications in movies, video games and training systems. Wind force is the main energy resource for generating ocean waves, which are the result of the interaction between wind and the ocean surface. While numerous methods to handle simulating oceans and other fluid phenomena have undergone rapid development during the past years in the field of computer graphic, few of them consider to construct ocean surface height field from the perspective of wind force driving ocean waves. We introduce wind force to the construction of the ocean surface height field through applying wind field data and wind-driven wave particles. Continual and realistic ocean waves result from the overlap of wind-driven wave particles, and a strategy was proposed to control these discrete wave particles and simulate an endless ocean surface. The results showed that the new method is capable of obtaining a realistic ocean scene under the influence of wind fields at real time rates.

  6. Wave model downscaling for coastal applications

    Science.gov (United States)

    Valchev, Nikolay; Davidan, Georgi; Trifonova, Ekaterina; Andreeva, Nataliya

    2010-05-01

    Downscaling is a suitable technique for obtaining high-resolution estimates from relatively coarse-resolution global models. Dynamical and statistical downscaling has been applied to the multidecadal simulations of ocean waves. Even as large-scale variability might be plausibly estimated from these simulations, their value for the small scale applications such as design of coastal protection structures and coastal risk assessment is limited due to their relatively coarse spatial and temporal resolutions. Another advantage of the high resolution wave modeling is that it accounts for shallow water effects. Therefore, it can be used for both wave forecasting at specific coastal locations and engineering applications that require knowledge about extreme wave statistics at or near the coastal facilities. In the present study downscaling is applied to both ECMWF and NCEP/NCAR global reanalysis of atmospheric pressure over the Black Sea with 2.5 degrees spatial resolution. A simplified regional atmospheric model is employed for calculation of the surface wind field at 0.5 degrees resolution that serves as forcing for the wave models. Further, a high-resolution nested WAM/SWAN wave model suite of nested wave models is applied for spatial downscaling. It aims at resolving the wave conditions in a limited area at the close proximity to the shore. The pilot site is located in the northern part the Bulgarian Black Sea shore. The system involves the WAM wave model adapted for basin scale simulation at 0.5 degrees spatial resolution. The WAM output for significant wave height, mean wave period and mean angle of wave approach is used in terms of external boundary conditions for the SWAN wave model, which is set up for the western Black Sea shelf at 4km resolution. The same model set up on about 400m resolution is nested to the first SWAN run. In this case the SWAN 2D spectral output provides boundary conditions for the high-resolution model run. The models are implemented for a

  7. Observations and estimates of wave-driven water level extremes at the Marshall Islands

    Science.gov (United States)

    Merrifield, M. A.; Becker, J. M.; Ford, M.; Yao, Y.

    2014-10-01

    Wave-driven extreme water levels are examined for coastlines protected by fringing reefs using field observations obtained in the Republic of the Marshall Islands. The 2% exceedence water level near the shoreline due to waves is estimated empirically for the study sites from breaking wave height at the outer reef and by combining separate contributions from setup, sea and swell, and infragravity waves, which are estimated based on breaking wave height and water level over the reef flat. Although each component exhibits a tidal dependence, they sum to yield a 2% exceedence level that does not. A hindcast based on the breaking wave height parameterization is used to assess factors leading to flooding at Roi-Namur caused by an energetic swell event during December 2008. Extreme water levels similar to December 2008 are projected to increase significantly with rising sea level as more wave and tide events combine to exceed inundation threshold levels.

  8. The Global Signature of Ocean Wave Spectra

    Science.gov (United States)

    Portilla-Yandún, Jesús

    2018-01-01

    A global atlas of ocean wave spectra is developed and presented. The development is based on a new technique for deriving wave spectral statistics, which is applied to the extensive ERA-Interim database from European Centre of Medium-Range Weather Forecasts. Spectral statistics is based on the idea of long-term wave systems, which are unique and distinct at every geographical point. The identification of those wave systems allows their separation from the overall spectrum using the partition technique. Their further characterization is made using standard integrated parameters, which turn out much more meaningful when applied to the individual components than to the total spectrum. The parameters developed include the density distribution of spectral partitions, which is the main descriptor; the identified wave systems; the individual distribution of the characteristic frequencies, directions, wave height, wave age, seasonal variability of wind and waves; return periods derived from extreme value analysis; and crossing-sea probabilities. This information is made available in web format for public use at http://www.modemat.epn.edu.ec/#/nereo. It is found that wave spectral statistics offers the possibility to synthesize data while providing a direct and comprehensive view of the local and regional wave conditions.

  9. Planetary wave-gravity wave interactions during mesospheric inversion layer events

    Science.gov (United States)

    Ramesh, K.; Sridharan, S.; Raghunath, K.; Vijaya Bhaskara Rao, S.; Bhavani Kumar, Y.

    2013-07-01

    lidar temperature observations over Gadanki (13.5°N, 79.2°E) show a few mesospheric inversion layer (MIL) events during 20-25 January 2007. The zonal mean removed SABER temperature shows warm anomalies around 50°E and 275°E indicating the presence of planetary wave of zonal wave number 2. The MIL amplitudes in SABER temperature averaged for 10°N-15°N and 70°E-90°E show a clear 2 day wave modulation during 20-28 January 2007. Prior to 20 January 2007, a strong 2day wave (zonal wave number 2) is observed in the height region of 80-90 km and it gets largely suppressed during 20-26 January 2007 as the condition for vertical propagation is not favorable, though it prevails at lower heights. The 10 day mean zonal wind over Tirunelveli (8.7°N, 77.8°E) shows deceleration of eastward winds indicating the westward drag due to wave dissipation. The nightly mean MF radar observed zonal winds show the presence of alternating eastward and westward winds during the period of 20-26 January 2007. The two dimensional spectrum of Rayleigh lidar temperature observations available for the nights of 20, 22, and 24 January 2007 shows the presence of gravity wave activity with periods 18 min, 38 min, 38 min, and vertical wavelengths 6.4 km, 4.0 km, 6.4 km respectively. From the dispersion relation of gravity waves, it is inferred that these waves are internal gravity waves rather than inertia gravity waves with the horizontal phase speeds of ~40 m/s, ~37 m/s, and ~50 m/s respectively. Assuming the gravity waves are eastward propagating waves, they get absorbed only in the eastward local wind fields of the planetary wave thereby causing turbulence and eddy diffusion which can be inferred from the estimation of large drag force due to the breaking of gravity wave leading to the formation of large amplitude inversion events in alternate nights. The present study shows that, the mesospheric temperature inversion is caused mainly due to the gravity wave breaking and the inversion

  10. Evolution of offshore wind waves tracked by surface drifters with a point-positioning GPS sensor

    Science.gov (United States)

    Komatsu, K.

    2009-12-01

    Wind-generated waves have been recognized as one of the most important factors of the sea surface roughness which plays crucial roles in various air-sea interactions such as energy, momentum, heat and gas exchanges. At the same time, wind waves with extreme wave heights representatively called as freak or rogue waves have been a matter of great concern for many people involved in shipping, fishing, constracting, surfing and other marine activities, because such extreme waves frequently affect on the marine activities and sometimes cause serious disasters. Nevertheless, investigations of actual conditions for the evolution of wind waves in the offshore region are less and sparse in contrast to dense monitoring networks in the coastal regions because of difficulty of offshore observation with high accuracy. Recently accurate in situ observation of offshore wind waves is getting possible at low cost owing to a wave height and direction sensor developed by Harigae et al. (2004) by installing a point-positioning GPS receiver on a surface drifting buoy. The point-positioning GPS sensor can extract three dimensional movements of the buoy excited by ocean waves with minimizing effects of GPS point-positioning errors through the use of a high-pass filter. Two drifting buoys equipped with the GPS-based wave sensor charged by solar cells were drifted in the western North Pacific and one of them continued to observe wind waves during 16 months from Sep. 2007. The RMSE of the GPS-based wave sensor was less than 10cm in significant wave height and about 1s in significant wave period in comparison with other sensors, i.e. accelerometers installed on drifting buoys of Japan Meteorological Agency, ultrasonic sensors placed at the Hiratsuka observation station of the University of Tokyo and altimeter of the JASON-1. The GPS-based wave buoys enabled us to detect freak waves defined as waves whose height is more than twice the significant wave height. The observation conducted by the

  11. An antithetic variate to facilitate upper-stem height measurements for critical height sampling with importance sampling

    Science.gov (United States)

    Thomas B. Lynch; Jeffrey H. Gove

    2013-01-01

    Critical height sampling (CHS) estimates cubic volume per unit area by multiplying the sum of critical heights measured on trees tallied in a horizontal point sample (HPS) by the HPS basal area factor. One of the barriers to practical application of CHS is the fact that trees near the field location of the point-sampling sample point have critical heights that occur...

  12. Infragravity-wave dynamics in shallow water : energy dissipation and role in sand suspension and transport

    NARCIS (Netherlands)

    de Bakker, A.T.M.|info:eu-repo/dai/nl/371573734

    2016-01-01

    Infragravity waves (20-200 s) receive their energy from sea-swell waves (2-20 s), and are thought to be important to beach erosion during storms, when they can reach up to several meters in height. Numerous studies have observed that on sandy beaches infragravity waves can lose a large part of their

  13. Finite energy wave signals of extremal amplitude in the spatial NLS-dynamics

    NARCIS (Netherlands)

    van Groesen, Embrecht W.C.; Andonowati, A.

    2006-01-01

    With the aim to find extremal properties of extreme waves, we consider waves of maximal crest (and wave) height in the model of the spatial NLS-dynamics. Using the two motion invariants momentum and Hamiltonian as constraints, we show that so-called cornered solitons provide the maximal crest

  14. Stress wave velocity patterns in the longitudinal-radial plane of trees for defect diagnosis

    Science.gov (United States)

    Guanghui Li; Xiang Weng; Xiaocheng Du; Xiping Wang; Hailin Feng

    2016-01-01

    Acoustic tomography for urban tree inspection typically uses stress wave data to reconstruct tomographic images for the trunk cross section using interpolation algorithm. This traditional technique does not take into account the stress wave velocity patterns along tree height. In this study, we proposed an analytical model for the wave velocity in the longitudinal–...

  15. Wave Generation Theory

    DEFF Research Database (Denmark)

    Frigaard, Peter; Høgedal, Michael; Christensen, Morten

    The intention of this manual is to provide some formulas and techniques which can be used for generating waves in hydraulic laboratories. Both long crested waves (2-D waves) and short crested waves (3-D waves) are considered.......The intention of this manual is to provide some formulas and techniques which can be used for generating waves in hydraulic laboratories. Both long crested waves (2-D waves) and short crested waves (3-D waves) are considered....

  16. Spectral Wave Characteristics in the Nearshore Waters of Northwestern Bay of Bengal

    Science.gov (United States)

    Anjali Nair, M.; Sanil Kumar, V.; Amrutha, M. M.

    2018-03-01

    The spectral wave characteristics in the nearshore waters of northwestern Bay of Bengal are presented based on the buoy-measured data from February 2013 to December 2015 off Gopalpur at 15-m water depth. The mean seasonal significant wave height and mean wave period indicate that the occurrence of higher wave heights and wave periods is during the southwest monsoon period (June-September). 74% of the sea surface height variance in a year is a result of waves from 138 to 228° and 16% are from 48 to 138°. Strong inter-annual variability is observed in the monthly average wave parameters due to the occurrence of tropical cyclones. Due to the influence of the tropical cyclone Phailin, maximum significant wave height of 6.7 m is observed on 12 October 2013 and that due to tropical cyclone Hudhud whose track is 250 southwest of the study location is 5.84 m on 12 October 2014. Analysis revealed that a single tropical cyclone influenced the annual maximum significant wave height and not the annual average value which is almost same ( 1 m) in 2014 and 2015. The waves in the northwestern Bay of Bengal are influenced by the southwest and northeast monsoons, southern ocean swells and cyclones.

  17. Residual liquefaction of seabed under standing waves

    DEFF Research Database (Denmark)

    Kirca, V.S. Ozgur; Sumer, B. Mutlu; Fredsøe, Jørgen

    2013-01-01

    This paper presents the results of an experimental study of the seabed liquefaction beneath standing waves. Silt (with d50 =0.070mm) was used in the experiments. Two kinds of measurements were carried out: pore water pressure measurements and water surface elevation measurements. These measurements...... were synchronized with video recording of the liquefaction process from the side. The ranges of the various quantities in the experiments were wave height H= 5.9-12.0 cm, wave period T= 1.09s, and water depth h=30 cm. The experiments show that the seabed liquefaction under standing waves, although...... qualitatively similar, show features different from that caused by progressive waves. The pore water pressure builds up (or accumulated) in the areas around the node and subsequently spreads out toward the antinodes. The experimental results imply that this transport is caused by a diffusion mechanism...

  18. A typical wave wake from high-speed vessels: its group structure and run-up

    Directory of Open Access Journals (Sweden)

    I. Didenkulova

    2013-02-01

    Full Text Available High-amplitude water waves induced by high-speed vessels are regularly observed in Tallinn Bay, the Baltic Sea, causing intense beach erosion and disturbing marine habitants in the coastal zone. Such a strong impact on the coast may be a result of a certain group structure of the wave wake. In order to understand it, here we present an experimental study of the group structure of these wakes at Pikakari beach, Tallinn Bay. The most energetic vessel waves at this location (100 m from the coast at the water depth 2.7 m have amplitudes of about 1 m and periods of 8–10 s and cause maximum run-up heights on a beach up to 1.4 m. These waves represent frequency modulated packets where the largest and longest waves propagate ahead of other smaller amplitude and period waves. Sometimes the groups of different heights and periods can be separated even within one wave wake event. The wave heights within a wake are well described by the Weibull distribution, which has different parameters for wakes from different vessels. Wave run-up heights can also be described by Weibull distribution and its parameters can be connected to the parameters of the distribution of wave heights 100 m from the coast. Finally, the run-up of individual waves within a packet is studied. It is shown that the specific structure of frequency modulated wave packets, induced by high-speed vessels, leads to a sequence of high wave run-ups at the coast, even when the original wave heights are rather moderate. This feature can be a key to understanding the significant impact on coasts caused by fast vessels.

  19. Extreme Wave Analysis by Integrating Model and Wave Buoy Data

    Directory of Open Access Journals (Sweden)

    Fabio Dentale

    2018-03-01

    Full Text Available Estimating the extreme values of significant wave height (HS, generally described by the HS return period TR function HS(TR and by its confidence intervals, is a necessity in many branches of coastal science and engineering. The availability of indirect wave data generated by global and regional wind and wave model chains have brought radical changes to the estimation procedures of such probability distribution—weather and wave modeling systems are routinely run all over the world, and HS time series for each grid point are produced and published after assimilation (analysis of the ground truth. However, while the sources of such indirect data are numerous, and generally of good quality, many aspects of their procedures are hidden to the users, who cannot evaluate the reliability and the limits of the HS(TR deriving from such data. In order to provide a simple engineering tool to evaluate the probability of extreme sea-states as well as the quality of such estimates, we propose here a procedure based on integrating HS time series generated by model chains with those recorded by wave buoys in the same area.

  20. Forecasting ocean wave energy: A Comparison of the ECMWF wave model with time series methods

    DEFF Research Database (Denmark)

    Reikard, Gordon; Pinson, Pierre; Bidlot, Jean

    2011-01-01

    Recently, the technology has been developed to make wave farms commercially viable. Since electricity is perishable, utilities will be interested in forecasting ocean wave energy. The horizons involved in short-term management of power grids range from as little as a few hours to as long as several...... days. In selecting a method, the forecaster has a choice between physics-based models and statistical techniques. A further idea is to combine both types of models. This paper analyzes the forecasting properties of a well-known physics-based model, the European Center for Medium-Range Weather Forecasts...... (ECMWF) Wave Model, and two statistical techniques, time-varying parameter regressions and neural networks. Thirteen data sets at locations in the Atlantic and Pacific Oceans and the Gulf of Mexico are tested. The quantities to be predicted are the significant wave height, the wave period, and the wave...

  1. Rogue waves in a water tank: Experiments and modeling

    Science.gov (United States)

    Lechuga, Antonio

    2013-04-01

    Recently many rogue waves have been reported as the main cause of ship incidents on the sea. One of the main characteristics of rogue waves is its elusiveness: they present unexpectedly and disappear in the same wave. Some authors (Zakharov and al.2010) are attempting to find the probability of their appearances apart from studyingthe mechanism of the formation. As an effort on this topic we tried the generation of rogue waves in a water wave tank using a symmetric spectrum(Akhmediev et al. 2011) as input on the wave maker. The produced waves were clearly rogue waves with a rate (maximum wave height/ Significant wave height) of 2.33 and a kurtosis of 4.77 (Janssen 2003, Onorato 2006). These results were already presented (Lechuga 2012). Similar waves (in pattern aspect, but without being extreme waves) were described as crossing waves in a water tank(Shemer and Lichter1988). To go on further the next step has been to apply a theoretical model to the envelope of these waves. After some considerations the best model has been an analogue of the Ginzburg-Landau equation. This apparently amazing result is easily explained: We know that the Ginzburg-Landau model is related to some regular structures on the surface of a liquid and also in plasmas, electric and magnetic fields and other media. Another important characteristic of the model is that their solutions are invariants with respectto the translation group. The main aim of this presentation is to extract conclusions of the model and the comparison with the measured waves in the water tank.The nonlinear structure of waves and their regularity make suitable the use of the Ginzburg-Landau model to the envelope of generated waves in the tank,so giving us a powerful tool to cope with the results of our experiment.

  2. The determination of the mixing height. Current progress and problems

    Energy Technology Data Exchange (ETDEWEB)

    Gryning, S.E.; Beyrich, F.; Batchvarova, E. [eds.

    1997-10-01

    This report contains extended abstracts of presentations given at a EURASAP Workshop on The Determination of the Mixing Height - Current Progress and Problems. The Workshop, initiated from discussions with Peter Builtjes, was held at Risoe National Laboratory 1-3 October 1997 within the framework of EURASAP (European Association for the Sciences of Air Pollution). The specific topics and chairpersons of the Workshop were: Theoretical Considerations (Sven-Erik Gryning), Mixing Height Estimation from Turbulence Measurements and In-Situ Soundings (Douw Steyn), Mixing Height Determination from NWP-Models (Han van Dop), Climatology and Global Aspects (Werner Klug), Mixing Height Determination from Remote Systems (Werner Klug), Verification of Mixing Height Parameterizations and Models (Frank Beyrich), Mixing Height over Complex Terrain (Ekaterina Batchvarova), Internal Boundary Layers: Mixing Height in Coastal Areas and Over Cities (Allen White). The discussion at the end of the Workshop was chaired by Robert Bornstein. (au)

  3. Wave-current interactions at the FloWave Ocean Energy Research Facility

    Science.gov (United States)

    Noble, Donald; Davey, Thomas; Steynor, Jeffrey; Bruce, Tom; Smith, Helen; Kaklis, Panagiotis

    2015-04-01

    Physical scale model testing is an important part of the marine renewable energy development process, allowing the study of forces and device behaviour in a controlled environment prior to deployment at sea. FloWave is a new state-of-the-art ocean energy research facility, designed to provide large scale physical modelling services to the tidal and wave sector. It has the unique ability to provide complex multi-directional waves that can be combined with currents from any direction in the 25m diameter circular tank. The facility is optimised for waves around 2s period and 0.4m height, and is capable of generating currents upwards of 1.6m/s. This offers the ability to model metocean conditions suitable for most renewable energy devices at a typical scale of between 1:10 and 1:40. The test section is 2m deep, which can be classed as intermediate-depth for most waves of interest, thus the full dispersion equation must be solved as the asymptotic simplifications do not apply. The interaction between waves and currents has been studied in the tank. This has involved producing in the tank sets of regular waves, focussed wave groups, and random sea spectra including multi-directional sea states. These waves have been both inline-with and opposing the current, as well as investigating waves at arbitrary angles to the current. Changes in wave height and wavelength have been measured, and compared with theoretical results. Using theoretical wave-current interaction models, methods have been explored to "correct" the wave height in the central test area of the tank when combined with a steady current. This allows the wave height with current to be set equal to that without a current. Thus permitting, for example, direct comparison of device motion response between tests with and without current. Alternatively, this would also permit a specific wave height and current combination to be produced in the tank, reproducing recorded conditions at a particular site of interest. The

  4. Bali, Shaded Relief and Colored Height

    Science.gov (United States)

    2004-01-01

    The volcanic nature of the island of Bali is evident in this shaded relief image generated with data from the Shuttle Radar Topography Mission (SRTM).Bali, along with several smaller islands, make up one of the 27 Provinces of Indonesia. It lies over a major subduction zone where the Indo-Australian tectonic plate collides with the Sunda plate, creating one of the most volcanically active regions on the planet.The most significant feature on Bali is Gunung Agung, the symmetric, conical mountain at the right-center of the image. This 'stratovolcano,' 3,148 meters (10,308 feet) high, is held sacred in Balinese culture, and last erupted in 1963 after being dormant and thought inactive for 120 years. This violent event resulted in over 1,000 deaths, and coincided with a purification ceremony called Eka Dasa Rudra, meant to restore the balance between nature and man. This most important Balinese rite is held only once per century, and the almost exact correspondence between the beginning of the ceremony and the eruption is though to have great religious significance.Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations.Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot

  5. Colored Height and Shaded Relief, Central America

    Science.gov (United States)

    2002-01-01

    Panama, Costa Rica, Nicaragua, El Salvador, Honduras, Guatemala, Belize, southern Mexico and parts of Cuba and Jamaica are all seen in this image from NASA's Shuttle Radar Topography Mission. The dominant feature of the northern part of Central America is the Sierra Madre Range, spreading east from Mexico between the narrow Pacific coastal plain and the limestone lowland of the Yucatan Peninsula. Parallel hill ranges sweep across Honduras and extend south, past the Caribbean Mosquito Coast to lakes Managua and Nicaragua. The Cordillera Central rises to the south, gradually descending to Lake Gatun and the Isthmus of Panama. A highly active volcanic belt runs along the Pacific seaboard from Mexico to Costa Rica.High-quality satellite imagery of Central America has, until now, been difficult to obtain due to persistent cloud cover in this region of the world. The ability of SRTM to penetrate clouds and make three-dimensional measurements has allowed the generation of the first complete high-resolution topographic map of the entire region. This map was used to generate the image.Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the north-south direction. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow, red, and magenta, to white at the highest elevations.For an annotated version of this image, please select Figure 1, below: [figure removed for brevity, see original site] (Large image: 9 mB jpeg)Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on February 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar that flew twice on the Space Shuttle Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect

  6. World Globes, Shaded Relief and Colored Height

    Science.gov (United States)

    2003-01-01

    These images of the world were generated with data from the Shuttle Radar Topography Mission (SRTM). The SRTM Project has recently released a new global data set called SRTM30, where the original one arcsecond of latitude and longitude resolution (about 30 meters, or 98 feet, at the equator) was reduced to 30 arcseconds (about 928 meters, or 1496 feet.) These images were created from that data set and show the Earth as it would be viewed from a point in space centered over the Americas, Africa and the western Pacific.Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations.Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise,Washington, D.C.Orientation: North toward the top Image Data: shaded and colored SRTM elevation model Original Data Resolution: SRTM 1 arcsecond (about 30 meters or 98 feet

  7. Colored Height and Shaded Relief, Kamchatka Peninsula

    Science.gov (United States)

    2002-01-01

    Russia's Kamchatka Peninsula, lying between the Sea of Okhotsk to the west and the Bering Sea and Pacific Ocean to the east, is one of the most active volcanic regions along the Pacific Ring of Fire. It covers an area about the size of Colorado but contains more than 100 volcanoes stretching across the 1000-kilometer-long (620-mile-long) land mass. A dozen or more of these have active vents, with the youngest located along the eastern half of the peninsula. This color-coded shaded relief image, generated with data from the Shuttle Radar Topography Mission (SRTM), shows Kamchatka's volcanic nature to dramatic effect.Kliuchevskoi, one of the most active and renowned volcanoes in the world, dominates the main cluster of volcanoes called the Kliuchi group, visible as a circular feature in the center-right of the image. The two other main volcanic ranges lie along northeast-southwest lines, with the older, less active range occupying the center and western half of Kamchatka. The younger, more active belt begins at the southernmost point of the peninsula and continues upward along the Pacific coastline.Two visualization methods were combined to produce this image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the north-south direction, so northern slopes appear bright and southern slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and brown to white at the highest elevations.The Shuttle Radar Topography Mission flew aboard the Space Shuttle Endeavour, launched on February 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar that flew twice on the Space Shuttle Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (200

  8. Sinai Peninsula, Shaded Relief and Colored Height

    Science.gov (United States)

    2004-01-01

    The Sinai Peninsula, located between Africa and Asia, is a result of those two continents pulling apart from each other. Earth's crust is cracking, stretching, and lowering along the two northern branches of the Red Sea, namely the Gulf of Suez, seen here on the west (left), and the Gulf of Aqaba, seen to the east (right). This color-coded shaded relief image shows the triangular nature of the peninsula, with the coast of the Mediterranean Sea forming the northern side of the triangle. The Suez Canal can be seen as the narrow vertical blue line in the upper left connecting the Red Sea to the Mediterranean. The peninsula is divided into three distinct parts; the northern region consisting chiefly of sandstone, plains and hills, the central area dominated by the Tih Plateau, and the mountainous southern region where towering peaks abound. Much of the Sinai is deeply dissected by river valleys, or wadis, that eroded during an earlier geologic period and break the surface of the plateau into a series of detached massifs with a few scattered oases. Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed

  9. Ireland, Shaded Relief and Colored Height

    Science.gov (United States)

    2005-01-01

    The island of Ireland comprises a large central lowland of limestone with a relief of hills surrounded by a discontinuous border of coastal mountains which vary greatly in geological structure. The mountain ridges of the south are composed of old red sandstone separated by limestone river valleys. Granite predominates in the mountains of Galway, Mayo and Donegal in the west and north-west and in Counties Down and Wicklow on the east coast, while a basalt plateau covers much of the north-east of the country. The central plain, which is broken in places by low hills, is extensively covered with glacial deposits of clay and sand. It has considerable areas of bog and numerous lakes. The island has seen at least two general glaciations and everywhere ice-smoothed rock, mountain lakes, glacial valleys and deposits of glacial sand, gravel and clay mark the passage of the ice. Two visualization methods were combined to produce this image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Geospatial-Intelligence Agency

  10. Accuracy of visual wave observation from merchant ships and estimated wave loads; Accuracy of visual wave observation from merchant ships and estimated wave loads

    Energy Technology Data Exchange (ETDEWEB)

    Kawabe, H. [National Defense Academy, Kanagawa (Japan); Masaoka, K. [University of Osaka Prefecture, Osaka (Japan). Faculty of Engineering

    1998-06-01

    There is a large number of studies on discussions concerning accuracy of visual observation of waves and the correction method thereon. This paper give considerations on observation accuracy placing a viewpoint on that by merchant ships. Based on ship meteorological observation tables reported to the Meteorological Agency of Japan on meteorology in North Pacific during 14 years from 1976 to1989, wave observation values taken by merchant ships and observation ships were compared statistically to investigate the accuracy of visual wave observations carried out by merchant ships. With regard to wave heights, the observation values taken by the observation ships and the merchant ships have strong correlation, where the merchant ships evaluate them somewhat higher than the observation ships. Regarding wave cycles of wind waves, the merchant ships tend to have the observation values on longer cycle side. Correlation between the observations values by the merchant ships and the observation ships is weak both in wind waves and swells. There is not much of variation in accuracy of observations during daytime and at night performed by the merchant ships. It will be necessary in the future to give considerations on a method to correct the observation values on wave cycles taken by the merchant ship, and on a correction method in which both of the wave cycles and the wave heights are corrected simultaneously to make the observation values of the merchant ship equal to those of the observation ships. Thus, the observation values reported by general merchant ships in a large number every year will have to be utilized more effectively. 11 refs., 21 figs., 2 tabs.

  11. Simple analytical relations for ship bow waves

    Science.gov (United States)

    Noblesse, Francis; Delhommeau, G.?Rard; Guilbaud, Michel; Hendrix, Dane; Yang, Chi

    Simple analytical relations for the bow wave generated by a ship in steady motion are given. Specifically, simple expressions that define the height of a ship bow wave, the distance between the ship stem and the crest of the bow wave, the rise of water at the stem, and the bow wave profile, explicitly and without calculations, in terms of the ship speed, draught, and waterline entrance angle, are given. Another result is a simple criterion that predicts, also directly and without calculations, when a ship in steady motion cannot generate a steady bow wave. This unsteady-flow criterion predicts that a ship with a sufficiently fine waterline, specifically with waterline entrance angle 2, may generate a steady bow wave at any speed. However, a ship with a fuller waterline (25E) can only generate a steady bow wave if the ship speed is higher than a critical speed, defined in terms of αE by a simple relation. No alternative criterion for predicting when a ship in steady motion does not generate a steady bow wave appears to exist. A simple expression for the height of an unsteady ship bow wave is also given. In spite of their remarkable simplicity, the relations for ship bow waves obtained in the study (using only rudimentary physical and mathematical considerations) are consistent with experimental measurements for a number of hull forms having non-bulbous wedge-shaped bows with small flare angle, and with the authors' measurements and observations for a rectangular flat plate towed at a yaw angle.

  12. Hilar height ratio in normal Korea

    International Nuclear Information System (INIS)

    Yoo, Kyung Ho; Lee, Nam Joon; Seol, Hae Young; Chung, Kyoo Byung

    1979-01-01

    Hilar displacement is one of the significant sign of pulmonary volume change. The hilar height ratio (HHR) is a value that express the normal position of hilum in its hemithorax, and it is calculated by dividing the distance from the hilum to the lung apex by the distance from the hilum to the diaphragm. Displacement of one hilum is usually easy to detect but both are displaced in the same direction especially, recognition is more difficult. Knowledge of normal HHR allows evaluation of hilar positional change even when the relative hilar position are not altered. Normal chest PA views of 275 cases taken at Korea University Hospital during the period of April 1978 to Jun 1979 were analyzed. The right hilum is positioned in lower half of the right hemithorax, while the left hilum is situated in the upper half of left hemithorax. The difference of hilar ratio according to age group is slight, but there is significant difference between right-HHR and left-HHR. The value of right-HHR is 1.28 ± 0.14, the value of left-HHR is 0.88 ± 0.09.

  13. [Is olfactory function impaired in moderate height?].

    Science.gov (United States)

    Kühn, M; Welsch, H; Zahnert, T; Hummel, Thomas

    2009-09-01

    The human sense of smell seems to be influenced by the surrounding barometric pressure. These factors appear to be especially important during flights, for example, in order to recognize the smell of fire etc. Thus, questions are whether pilots or passengers exhibit an impaired smell sensitivity when tested at moderate heights, or, whether changes in humidity would affect the sense of smell. Using climate chambers, odor discrimination and butanol odor thresholds were tested in 77 healthy normosmic volunteers (5 female, 72 male; aged 25+/-8 years from 18 up to 53 years) under hypobaric (2 700+/-20 m, 20 degrees C+/-1 K, rh=50+/-5%) and hyperbaric, (10+/-0.5 m (2 bar)) and different humidity conditions (30 vs. 80%, 20 degrees C+/-1 K, normobaric). During all conditions cognitive performance was tested. Among other effects, olfactory sensitivity was impaired at threshold, but not suprathreshold level, in a hypobaric compared to a hyperbaric milieu, and thresholds were lower in humid, compared to relatively dry conditions. In conclusion, environmental conditions modulate the sense of smell, and may, consecutively, influence results from olfactory tests. During flight hypobaric conditions, mild hypoxia and dry air may cause impaired sensitivity of smell. Georg Thieme Verlag KG Stuttgart * New York.

  14. Subexponential estimates in Shirshov's theorem on height

    International Nuclear Information System (INIS)

    Belov, Aleksei Ya; Kharitonov, Mikhail I

    2012-01-01

    Suppose that F 2,m is a free 2-generated associative ring with the identity x m =0. In 1993 Zelmanov put the following question: is it true that the nilpotency degree of F 2,m has exponential growth? We give the definitive answer to Zelmanov's question by showing that the nilpotency class of an l-generated associative algebra with the identity x d =0 is smaller than Ψ(d,d,l), where Ψ(n,d,l)=2 18 l(nd) 3log 3 (nd)+13 d 2 . This result is a consequence of the following fact based on combinatorics of words. Let l, n and d≥n be positive integers. Then all words over an alphabet of cardinality l whose length is not less than Ψ(n,d,l) are either n-divisible or contain x d ; a word W is n-divisible if it can be represented in the form W=W 0 W 1 …W n so that W 1 ,...,W n are placed in lexicographically decreasing order. Our proof uses Dilworth's theorem (according to V.N. Latyshev's idea). We show that the set of not n-divisible words over an alphabet of cardinality l has height h 87 l·n 12log 3 n+48 . Bibliography: 40 titles.

  15. Clinical longitudinal standards for height, weight, height velocity, weight velocity, and stages of puberty.

    Science.gov (United States)

    Tanner, J M; Whitehouse, R H

    1976-01-01

    New charts for height, weight, height velocity, and weight velocity are presented for clinical (as opposed to population survey) use. They are based on longitudinal-type growth curves, using the same data as in the British 1965 growth standards. In the velocity standards centiles are given for children who are early- and late-maturing as well as for those who mature at the average age (thus extending the use of the previous charts). Limits of normality for the age of occurrence of the adolescent growth spurt are given and also for the successive stages of penis, testes, and pubic hair development in boys, and for stages of breast and pubic hair development in girls. PMID:952550

  16. Trapped waves on the mid-latitude β-plane

    Science.gov (United States)

    Paldor, Nathan; Sigalov, Andrey

    2008-08-01

    A new type of approximate solutions of the Linearized Shallow Water Equations (LSWE) on the mid-latitude β-plane, zonally propagating trapped waves with Airy-like latitude-dependent amplitude, is constructed in this work, for sufficiently small radius of deformation. In contrast to harmonic Poincare and Rossby waves, these newly found trapped waves vanish fast in the positive half-axis, and their zonal phase speed is larger than that of the corresponding harmonic waves for sufficiently large meridional domains. Our analysis implies that due to the smaller radius of deformation in the ocean compared with that in the atmosphere, the trapped waves are relevant to observations in the ocean whereas harmonic waves typify atmospheric observations. The increase in the zonal phase speed of trapped Rossby waves compared with that of harmonic ones is consistent with recent observations that showed that Sea Surface Height features propagated westwards faster than the phase speed of harmonic Rossby waves.

  17. Tropical cyclogenesis in a tropical wave critical layer: easterly waves

    Directory of Open Access Journals (Sweden)

    T. J. Dunkerton

    2009-08-01

    cyclonic vorticity and weak deformation by the resolved flow, (ii containment of moisture entrained by the developing gyre and/or lofted by deep convection therein, (iii confinement of mesoscale vortex aggregation, (iv a predominantly convective type of heating profile, and (v maintenance or enhancement of the parent wave until the vortex becomes a self-sustaining entity and emerges from the wave as a tropical depression. The entire sequence is likened to the development of a marsupial infant in its mother's pouch. These ideas are formulated in three new hypotheses describing the flow kinematics and dynamics, moist thermodynamics and wave/vortex interactions comprising the "marsupial paradigm". A survey of 55 named tropical storms in 1998–2001 reveals that actual critical layers sometimes resemble the ideal east-west train of cat's eyes, but are usually less regular, with one or more recirculation regions in the co-moving frame. It is shown that the kinematics of isolated proto-vortices carried by the wave also can be visualized in a frame of reference translating at or near the phase speed of the parent wave. The proper translation speeds for wave and vortex may vary with height owing to vertical shear and wave-vortex interaction. Some implications for entrainment/containment of vorticity and moisture in the cat's eye are discussed from this perspective, based on the observational survey.

  18. A wave model test bed study for wave energy resource characterization

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhaoqing; Neary, Vincent S.; Wang, Taiping; Gunawan, Budi; Dallman, Annie R.; Wu, Wei-Cheng

    2017-12-01

    This paper presents a test bed study conducted to evaluate best practices in wave modeling to characterize energy resources. The model test bed off the central Oregon Coast was selected because of the high wave energy and available measured data at the site. Two third-generation spectral wave models, SWAN and WWIII, were evaluated. A four-level nested-grid approach—from global to test bed scale—was employed. Model skills were assessed using a set of model performance metrics based on comparing six simulated wave resource parameters to observations from a wave buoy inside the test bed. Both WWIII and SWAN performed well at the test bed site and exhibited similar modeling skills. The ST4 package with WWIII, which represents better physics for wave growth and dissipation, out-performed ST2 physics and improved wave power density and significant wave height predictions. However, ST4 physics tended to overpredict the wave energy period. The newly developed ST6 physics did not improve the overall model skill for predicting the six wave resource parameters. Sensitivity analysis using different wave frequencies and direction resolutions indicated the model results were not sensitive to spectral resolutions at the test bed site, likely due to the absence of complex bathymetric and geometric features.

  19. ANALYTICAL SOLUTION FOR WAVES IN PLANETS WITH ATMOSPHERIC SUPERROTATION. II. LAMB, SURFACE, AND CENTRIFUGAL WAVES

    International Nuclear Information System (INIS)

    Peralta, J.; López-Valverde, M. A.; Imamura, T.; Read, P. L.; Luz, D.; Piccialli, A.

    2014-01-01

    This paper is the second in a two-part study devoted to developing tools for a systematic classification of the wide variety of atmospheric waves expected on slowly rotating planets with atmospheric superrotation. Starting with the primitive equations for a cyclostrophic regime, we have deduced the analytical solution for the possible waves, simultaneously including the effect of the metric terms for the centrifugal force and the meridional shear of the background wind. In those cases where the conditions for the method of the multiple scales in height are met, these wave solutions are also valid when vertical shear of the background wind is present. A total of six types of waves have been found and their properties were characterized in terms of the corresponding dispersion relations and wave structures. In this second part, we study the waves' solutions when several atmospheric approximations are applied: Lamb, surface, and centrifugal waves. Lamb and surface waves are found to be quite similar to those in a geostrophic regime. By contrast, centrifugal waves turn out to be a special case of Rossby waves that arise in atmospheres in cyclostrophic balance. Finally, we use our results to identify the nature of the waves behind atmospheric periodicities found in polar and lower latitudes of Venus's atmosphere

  20. ANALYTICAL SOLUTION FOR WAVES IN PLANETS WITH ATMOSPHERIC SUPERROTATION. II. LAMB, SURFACE, AND CENTRIFUGAL WAVES

    Energy Technology Data Exchange (ETDEWEB)

    Peralta, J.; López-Valverde, M. A. [Instituto de Astrofísica de Andalucía (CSIC), Glorieta de la Astronomía, 18008 Granada (Spain); Imamura, T. [Institute of Space and Astronautical Science-Japan Aerospace Exploration Agency 3-1-1, Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Read, P. L. [Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford (United Kingdom); Luz, D. [Centro de Astronomia e Astrofísica da Universidade de Lisboa (CAAUL), Observatório Astronómico de Lisboa, Tapada da Ajuda, 1349-018 Lisboa (Portugal); Piccialli, A., E-mail: peralta@iaa.es [LATMOS, UVSQ, 11 bd dAlembert, 78280 Guyancourt (France)

    2014-07-01

    This paper is the second in a two-part study devoted to developing tools for a systematic classification of the wide variety of atmospheric waves expected on slowly rotating planets with atmospheric superrotation. Starting with the primitive equations for a cyclostrophic regime, we have deduced the analytical solution for the possible waves, simultaneously including the effect of the metric terms for the centrifugal force and the meridional shear of the background wind. In those cases where the conditions for the method of the multiple scales in height are met, these wave solutions are also valid when vertical shear of the background wind is present. A total of six types of waves have been found and their properties were characterized in terms of the corresponding dispersion relations and wave structures. In this second part, we study the waves' solutions when several atmospheric approximations are applied: Lamb, surface, and centrifugal waves. Lamb and surface waves are found to be quite similar to those in a geostrophic regime. By contrast, centrifugal waves turn out to be a special case of Rossby waves that arise in atmospheres in cyclostrophic balance. Finally, we use our results to identify the nature of the waves behind atmospheric periodicities found in polar and lower latitudes of Venus's atmosphere.

  1. Statistical investigation of expected wave energy and its reliability

    International Nuclear Information System (INIS)

    Ozger, M.; Altunkaynak, A.; Sen, Z.

    2004-01-01

    The statistical behavior of wave energy at a single site is derived by considering simultaneous variations in the period and wave height. In this paper, the general wave power formulation is derived by using the theory of perturbation. This method leads to a general formulation of the wave power expectation and other statistical parameter expressions, such as standard deviation and coefficient of variation. The statistical parameters, namely the mean value and variance of wave energy, are found in terms of the simple statistical parameters of period, significant wave height and zero up-crossing period. The elegance of these parameters is that they are distribution free. These parameters provide a means for defining the wave energy distribution function by employing the Chebyschev's inequality. Subsequently, an approximate probability distribution function of the wave energy is also derived for assessment of risk and reliability associated with wave energy. Necessary simple charts are given for risk and reliability assessments. Two procedures are presented for such assessments in wave energy calculations and the applications of these procedures are provided for wave energy potential assessment in the regions of the Pacific Ocean off the west coast of U.S. (author)

  2. Statistical investigation of expected wave energy and its reliability

    International Nuclear Information System (INIS)

    Oezger, Mehmet; Altunkaynak, Abduesselam; Sen, Zekai

    2004-01-01

    The statistical behavior of wave energy at a single site is derived by considering simultaneous variations in the period and wave height. In this paper, the general wave power formulation is derived by using the theory of perturbation. This method leads to a general formulation of the wave power expectation and other statistical parameter expressions, such as standard deviation and coefficient of variation. The statistical parameters, namely the mean value and variance of wave energy, are found in terms of the simple statistical parameters of period, significant wave height and zero up-crossing period. The elegance of these parameters is that they are distribution free. These parameters provide a means for defining the wave energy distribution function by employing the Chebyschev's inequality. Subsequently, an approximate probability distribution function of the wave energy is also derived for assessment of risk and reliability associated with wave energy. Necessary simple charts are given for risk and reliability assessments. Two procedures are presented for such assessments in wave energy calculations and the applications of these procedures are provided for wave energy potential assessment in the regions of the Pacific Ocean off the west coast of U.S

  3. Relationship between eruption plume heights and seismic source amplitudes of eruption tremors and explosion events

    Science.gov (United States)

    Mori, A.; Kumagai, H.

    2016-12-01

    It is crucial to analyze and interpret eruption tremors and explosion events for estimating eruption size and understanding eruption phenomena. Kumagai et al. (EPS, 2015) estimated the seismic source amplitudes (As) and cumulative source amplitudes (Is) for eruption tremors and explosion events at Tungurahua, Ecuador, by the amplitude source location (ASL) method based on the assumption of isotropic S-wave radiation in a high-frequency band (5-10 Hz). They found scaling relations between As and Is for eruption tremors and explosion events. However, the universality of these relations is yet to be verified, and the physical meanings of As and Is are not clear. In this study, we analyzed the relations between As and Is for eruption tremors and explosion events at active volcanoes in Japan, and estimated As and Is by the ASL method. We obtained power-law relations between As and Is, in which the powers were different between eruption tremors and explosion events. These relations were consistent with the scaling relations at Tungurahua volcano. Then, we compared As with maximum eruption plume heights (H) during eruption tremors analyzed in this study, and found that H was proportional to 0.21 power of As. This relation is similar to the plume height model based on the physical process of plume rise, which indicates that H is proportional to 0.25 power of volumetric flow rate for plinian eruptions. This suggests that As may correspond to volumetric flow rate. If we assume a seismic source with volume changes and far-field S-wave, As is proportional to the source volume rate. This proportional relation and the plume height model give rise to the relation that H is proportional to 0.25 power of As. These results suggest that we may be able to estimate plume heights in realtime by estimating As during eruptions from seismic observations.

  4. Wind-wave, and turbidity time-series data from Little Holland Tract (station HWC), Sacramento-San Joaquin Delta, California

    Data.gov (United States)

    Department of the Interior — Time series data of water surface elevation, wave height, and turbidity were collected in Little Holland Tract (LHT) beginning in December 2015 as part of “Wind-wave...

  5. A study on the effect of gas flow rate on the wave characteristics in two-phase gas-liquid annular flow

    International Nuclear Information System (INIS)

    Han Huawei; Zhu Zhenfeng; Gabriel, Kamiel

    2006-01-01

    Interfacial waves play a very important role in the mass, momentum and energy transport phenomena in annular flow. In this paper, film thickness time-trace measurements for air-water annular flow were collected in a small vertical tube using a parallel wire probe. Using the data, a typical disturbance wave shape was obtained and wave properties (e.g., width, height, speed and roughness) were presented. The liquid mass flux ranged from 100 to 200 kg/m 2 s and the gas mass flux ranged from 18 to 47 kg/m 2 s. Disturbance wave characteristics were defined and the effects of changing the gas flow rate on the wave spacing, wave width, wave peak height and wave base height were studied. An average velocity model for the wave and base regions has been developed to determine the wave velocity. The investigation method could be further extended to annular-mist flow which frequently occurs in boiling water reactors

  6. Wave groupiness variations in the nearshore

    Science.gov (United States)

    List, J.H.

    1991-01-01

    This paper proposes a new definition of the groupiness factor, GF, based on the envelope of the incident-wave time series. It is shown that an envelope-based GF has several important advantages over the SIWEH-based groupiness factor, including objective criteria for determining the accuracy of the envelope function and well-defined numerical limits. Using this new GF, the variability of incident wave groupiness in the field is examined both temporally, in unbroken waves at a fixed location, and spatially, in a cross-shore array through the surf zone. Contrary to previous studies using the SIWEH-based GF, results suggest that incident wave groupiness may not be an independent parameter in unbroken waves; through a wide range of spectral shapes, from swell to storm waves, the groupiness did not vary significantly. As expected, the groupiness decreases rapidly as waves break through the surf zone, although significant wave height variability persists even through a saturated surf zone. The source of this inner surf zone groupiness is not identified; however, this observation implies that models of long wave generation must account for nonsteady radiation stress gradients landward of some narrow zone near the mean breakpoint. ?? 1991.

  7. The lifecycle of axisymmetric internal solitary waves

    Directory of Open Access Journals (Sweden)

    J. M. McMillan

    2010-09-01

    Full Text Available The generation and evolution of solitary waves by intrusive gravity currents in an approximate two-layer fluid with equal upper- and lower-layer depths is examined in a cylindrical geometry by way of theory and numerical simulations. The study is limited to vertically symmetric cases in which the density of the intruding fluid is equal to the average density of the ambient. We show that even though the head height of the intrusion decreases, it propagates at a constant speed well beyond 3 lock radii. This is because the strong stratification at the interface supports the formation of a mode-2 solitary wave that surrounds the intrusion head and carries it outwards at a constant speed. The wave and intrusion propagate faster than a linear long wave; therefore, there is strong supporting evidence that the wave is indeed nonlinear. Rectilinear Korteweg-de Vries theory is extended to allow the wave amplitude to decay as r-p with p=½ and the theory is compared to the observed waves to demonstrate that the width of the wave scales with its amplitude. After propagating beyond 7 lock radii the intrusion runs out of fluid. Thereafter, the wave continues to spread radially at a constant speed, however, the amplitude decreases sufficiently so that linear dispersion dominates and the amplitude decays with distance as r-1.

  8. Large Scale Model Test Investigation on Wave Run-Up in Irregular Waves at Slender Piles

    DEFF Research Database (Denmark)

    Ramirez, Jorge Robert Rodriguez; Frigaard, Peter; Andersen, Thomas Lykke

    2013-01-01

    An experimental large scale study on wave run-up generated loads on entrance platforms for offshore wind turbines was performed. The experiments were performed at GrosserWellenkanal (GWK), Forschungszentrum Küste (FZK) in Hannover, Germany. The present paper deals with the run-up heights determin...

  9. Crossing seas and occurrence of rogue waves

    Science.gov (United States)

    Bitner-Gregersen, Elzbieta; Toffoli, Alessandro

    2017-04-01

    The study is addressing crossing wave systems which may lead to formation of rogue waves. Onorato et al. (2006, 2010) have shown using the Nonlinear Schr?dringer (NLS) equations that the modulational instability and rogue waves can be triggered by a peculiar form of directional sea state, where two identical, crossing, narrow-banded random wave systems interact with each other. Such results have been underpinned by numerical simulations of the Euler equations solved with a Higher Order Spectral Method (HOSM) and experimental observations (Toffoli et al., 2011). They substantiate a dependence of the angle between the mean directions of propagation of the two crossing wave systems, with a maximum rogue wave probability for angles of approximately 40 degrees. Such an unusual sea state of two almost identical wave systems (approximately the same significant wave height and mean frequency) with high steepness and different directions was observed during the accident to the cruise ship Louis Majesty (Cavaleri et al. 2012). Occurrence of wind sea and swell having almost the same spectral period and significant wave height and crossing at the angle 40o low and intermediate wave conditions. They have not been found in a location off coast of Australia and Nigeria. There are some indications that in the future climate we may expect an increase number of occurrence of rogue-prone crossing sea states in some ocean regions An adopted partitioning procedure of a wave spectrum will impact the results. References Bitner-Gregersen, E.M. and Toffoli, A., 2014. Probability of occurrence of rogue sea states and consequences for design of marine structures. Special Issue of Ocean Dynamics, ISSN 1616-7341, 64(10), DOI 10.1007/s10236-014-0753-2. Cavaleri, L., Bertotti, L., Torrisi, L. Bitner-Gregersen, E., Serio, M. and Onorato, M., 2012. Rogue Waves in Crossing Seas: The Louis Majesty accident. J. Geophysical Research, 117, C00J10, doi:10.1029/2012JC007923 Onorato, M., A. Osborne, A

  10. Wave fronts of electromagnetic cyclotron harmonic waves

    International Nuclear Information System (INIS)

    Ohnuma, T.; Watanabe, T.

    1982-01-01

    In an inhomogeneous high-density magnetized plasma, the spatial properties of the wave fronts and ray trajectories of electromagnetic ordinary and extraordinary cyclotron harmonic waves are investigated. Those waves which are radiated from a local source are found to have wave fronts which are almost parallel to the magnetic field. Also, the reflective properties of the electromagnetic cyclotron harmonic waves are confirmed

  11. Australia, Shaded Relief and Colored Height

    Science.gov (United States)

    2004-01-01

    topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Location: 45 to 10 degrees South latitude, 112 to 155 degrees East longitude Orientation: North toward the top, Mercator projection Image Data: shaded and colored SRTM elevation model Date Acquired: February 2000

  12. Guiana Highlands, Shaded Relief and Colored Height

    Science.gov (United States)

    2003-01-01

    Doyle's 1912 best-seller 'The Lost World.'Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations.Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise,Washington, D.C.Location: 0.2 South to 8.7 degrees North latitude, 60 to 67.9 degrees West longitude Orientation: North toward the top Image Data: shaded and colored SRTM30 and GTOPO30 elevation models Data Resolution: SRTM 30 arcsecond (about 928 meters or 1496 feet) Date Acquired: February 2000 for SRTM

  13. Olduvai Gorge, Shaded Relief and Colored Height

    Science.gov (United States)

    2004-01-01

    topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Location: 3 degrees south latitude, 35 degrees east longitude Orientation: North toward the top, Mercator projection Size: 223 by 223 kilometers (138 by 138 miles) Image Data: shaded and colored SRTM elevation model Date Acquired: February 2000

  14. France, Shaded Relief and Colored Height

    Science.gov (United States)

    2003-01-01

    This image of France was generated with data from the Shuttle Radar Topography Mission (SRTM). For this broad view the resolution of the data was reduced to 6 arcseconds (about 185 meters north-south and 127 meters east-west), resampled to a Mercator projection, and the French border outlined. Even at this decreased resolution the variety of landforms comprising the country is readily apparent.The upper central part of this scene is dominated by the Paris Basin, which consists of a layered sequence of sedimentary rocks. Fertile soils over much of the area make good agricultural land. The Normandie coast to the upper left is characterized by high, chalk cliffs, while the Brittany coast (the peninsula to the left) is highly indented where deep valleys were drowned by the sea, and the Biscay coast to the southwest is marked by flat, sandy beaches.To the south, the Pyrenees form a natural border between France and Spain, and the south-central part of the country is dominated by the ancient Massif Central. Subject to volcanism that has only subsided in the last 10,000 years, these central mountains are separated from the Alps by the north-south trending Rhone River Basin.Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations.Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D

  15. Between tide and wave marks: a unifying model of physical zonation on littoral shores

    Directory of Open Access Journals (Sweden)

    Christopher E. Bird

    2013-09-01

    Full Text Available The effects of tides on littoral marine habitats are so ubiquitous that shorelines are commonly described as ‘intertidal’, whereas waves are considered a secondary factor that simply modifies the intertidal habitat. However mean significant wave height exceeds tidal range at many locations worldwide. Here we construct a simple sinusoidal model of coastal water level based on both tidal range and wave height. From the patterns of emergence and submergence predicted by the model, we derive four vertical shoreline benchmarks which bracket up to three novel, spatially distinct, and physically defined zones. The (1 emergent tidal zone is characterized by tidally driven emergence in air; the (2 wave zone is characterized by constant (not periodic wave wash; and the (3 submergent tidal zone is characterized by tidally driven submergence. The decoupling of tidally driven emergence and submergence made possible by wave action is a critical prediction of the model. On wave-dominated shores (wave height ≫ tidal range, all three zones are predicted to exist separately, but on tide-dominated shores (tidal range ≫ wave height the wave zone is absent and the emergent and submergent tidal zones overlap substantially, forming the traditional “intertidal zone”. We conclude by incorporating time and space in the model to illustrate variability in the physical conditions and zonation on littoral shores. The wave:tide physical zonation model is a unifying framework that can facilitate our understanding of physical conditions on littoral shores whether tropical or temperate, marine or lentic.

  16. Wave Dragon

    DEFF Research Database (Denmark)

    Kramer, Morten; Frigaard, Peter

    På foranledning af Löwenmark F.R.I, er der udført numeriske beregninger af Wave Dragons (herefter WD) armes effektivitet for forskellige geometriske udformninger. 5 geometriske modeller, hvor WD's arme er forkortet/forlænget er undersøgt for 3 forskellige drejninger af armene. I alt er 15...

  17. Combined Treatment with Gonadotropin-releasing Hormone Analog and Anabolic Steroid Hormone Increased Pubertal Height Gain and Adult Height in Boys with Early Puberty for Height.

    Science.gov (United States)

    Tanaka, Toshiaki; Naiki, Yasuhiro; Horikawa, Reiko

    2012-04-01

    Twenty-one boys with a height of 135 cm or less at onset of puberty were treated with a combination of GnRH analog and anabolic steroid hormone, and their pubertal height gain and adult height were compared with those of untreated 29 boys who enter puberty below 135 cm. The mean age at the start of treatment with a GnRH analog, leuprorelin acetate depot (Leuplin(®)) was 12.3 yr, a mean of 1.3 yr after the onset of puberty, and GnRH analog was administered every 3 to 5 wk thereafter for a mean duration of 4.1 yr. The anabolic steroid hormone was started approximately 1 yr after initiation of treatment with the GnRH analog. The mean pubertal height gain from onset of puberty till adult height was significantly greater in the combination treatment group (33.9 cm) than in the untreated group (26.4 cm) (ppenis and pubic hair is promoted by the anabolic steroid hormone, no psychosocial problems arose because of delayed puberty. No clinically significant adverse events appeared. Combined treatment with GnRH analog and anabolic steroid hormone significantly increased height gain during puberty and adult height in boys who entered puberty with a short stature, since the period until epiphyseal closure was extended due to deceleration of the bone age maturation by administration of the GnRH analog and the growth rate at this time was maintained by the anabolic steroid hormone.

  18. Numerical Modeling of Infragravity Wave Runup on Steep and Mildly Sloping Natural Beaches

    Science.gov (United States)

    Fiedler, J. W.; Smit, P.; Brodie, K. L.; McNinch, J.; Guza, R. T.; Gallien, T.

    2016-12-01

    We present ongoing work which aims to validate the non-hydrostatic model SWASH for wave runup and infragravity waves generated by a range of different incident wave spectra at the offshore boundary, including the effect of finite directional spread. Flume studies of wave runup are limited to normally incident (1D) sea and infragravity waves, but natural waves are directionally spread (2D), with substantially different dynamics from 1D. For example, refractive trapping (edge waves) is only possible with 2D waves, and the bound infragravity wave response to short wave groups is highly amplified for the special case of normal incidence. Selected case studies are modeled at Agate Beach, Oregon, a low slope (1:80) beach with maximum offshore wave heights greater than 7m, and Cardiff, California, a steep (1:8) beach with maximum wave heights of 2m. Peak periods ranged between 5-20 s at both sites. On both beaches, waves were measured on a transect from approximately 10m depth to the runup, using pressure sensors, current meters, and a scanning lidar. Bulk short wave quantities, wave runup, infragravity frequency spectra and energy fluxes are compared with SWASH. On the low slope beach with energetic incident waves, the observed horizontal runup excursions reach 140m ( 100s periods). Swash front velocities reached up to several m/s, causing short waves to stack up during runup drawdown. On reversal of the infragravity phase, the stacked short waves are swept onshore with the long wave front, effectively enhancing runup by phase coupling long and short waves. Statistical variability and nonlinearity in swash generation lead to time-varying runup heights. Here, we test these observations with 2D SWASH, as well as the sensitivity of modeled runup to the parameterization of bottom friction.

  19. The Damage To The Armour Layer Due To Extreme Waves

    Science.gov (United States)

    Oztunali Ozbahceci, Berguzar; Ergin, Aysen; Takayama, Tomotsuka

    2010-05-01

    The sea waves are not regular but random and chaotic. In order to understand this randomness, it is common to make individual wave analysis in time domain or spectral analysis in frequency domain. Characteristic wave heights like Hmax, H%2,H1-10, H1-3, Hmean are obtained through individual wave analysis in time domain. These characteristic wave heights are important because they are used in the design of different type of coastal structures. It is common to use significant wave height, H1-3,for the design of rubble mound structures. Therefore, only spectrally derived or zero-crossing significant wave height is usually reported for the rubble mound breakwaters without any information on larger waves. However, even the values of H1-3are similar; some train of irregular waves may exhibit a large fluctuation of instantaneous wave energy, while another train may not show such a fluctuation (Goda, 1998). Moreover, freak or rogue wave, simply defined as the wave exceeding at least twice the significant wave height may also occur. Those larger waves were called as extreme waves in this study and the effect of extreme waves on the damage to the armour layer of rubble mound breakwaters was investigated by means of hydraulic model experiment. Rock armored rubble mound breakwater model with 1:1.5 slope was constructed in the wave channel of Hydraulics Laboratory of the Disaster Prevention Research Institute of Kyoto University, Japan. The model was consisted of a permeable core layer, a filter and armour layer with two stones thicknesses. Size of stones were same for both of the slopes as Dn50(armour)=0.034m, Dn50(filter)=0.021m and Dn50(core)=0.0148m for armour, filter and core layers, respectively. Time series which are approximately equal to 1000 waves, with similar significant wave height but different extreme wave height cases were generated. In order to generate necessary time series in the wave channel, they were firstly computed by numerically. For the numerical

  20. Storm-wave trends in Mexican waters of the Gulf of Mexico and Caribbean Sea

    Directory of Open Access Journals (Sweden)

    E. Ojeda

    2017-08-01

    Full Text Available Thirty-year time series of hindcast wave data were analysed for 10 coastal locations along the eastern Mexican coast to obtain information about storm events occurring in the region, with the goal of examining the possible presence of interannual trends in the number of storm-wave events and their main features (wave height, duration and energy content. The storms were defined according to their significant wave height and duration, and the events were classified as related to either tropical cyclones or Norte events. The occurrence and characteristics of both types of events were analysed independently. There is no statistically significant change in the number of storm-wave events related to Nortes or their characteristics during the study period. However, there is a subtle increase in the number of events related to tropical cyclones in the western Caribbean region and a more evident increase in wave height and energy content of these events.

  1. Combined Treatment with Gonadotropin-releasing Hormone Analog and Anabolic Steroid Hormone Increased Pubertal Height Gain and Adult Height in Boys with Early Puberty for Height

    OpenAIRE

    Tanaka, Toshiaki; Naiki, Yasuhiro; Horikawa, Reiko

    2012-01-01

    Twenty-one boys with a height of 135 cm or less at onset of puberty were treated with a combination of GnRH analog and anabolic steroid hormone, and their pubertal height gain and adult height were compared with those of untreated 29 boys who enter puberty below 135 cm. The mean age at the start of treatment with a GnRH analog, leuprorelin acetate depot (Leuplin?) was 12.3 yr, a mean of 1.3 yr after the onset of puberty, and GnRH analog was administered every 3 to 5 wk thereafter for a mean d...

  2. Simulation of ICESat-2 canopy height retrievals for different ecosystems

    Science.gov (United States)

    Neuenschwander, A. L.

    2016-12-01

    Slated for launch in late 2017 (or early 2018), the ICESat-2 satellite will provide a global distribution of geodetic measurements from a space-based laser altimeter of both the terrain surface and relative canopy heights which will provide a significant benefit to society through a variety of applications ranging from improved global digital terrain models to producing distribution of above ground vegetation structure. The ATLAS instrument designed for ICESat-2, will utilize a different technology than what is found on most laser mapping systems. The photon counting technology of the ATLAS instrument onboard ICESat-2 will record the arrival time associated with a single photon detection. That detection can occur anywhere within the vertical distribution of the reflected signal, that is, anywhere within the vertical distribution of the canopy. This uncertainty of where the photon will be returned from within the vegetation layer is referred to as the vertical sampling error. Preliminary simulation studies to estimate vertical sampling error have been conducted for several ecosystems including woodland savanna, montane conifers, temperate hardwoods, tropical forest, and boreal forest. The results from these simulations indicate that the canopy heights reported on the ATL08 data product will underestimate the top canopy height in the range of 1 - 4 m. Although simulation results indicate the ICESat-2 will underestimate top canopy height, there is, however, a strong correlation between ICESat-2 heights and relative canopy height metrics (e.g. RH75, RH90). In tropical forest, simulation results indicate the ICESat-2 height correlates strongly with RH90. Similarly, in temperate broadleaf forest, the simulated ICESat-2 heights were also strongly correlated with RH90. In boreal forest, the simulated ICESat-2 heights are strongly correlated with RH75 heights. It is hypothesized that the correlations between simulated ICESat-2 heights and canopy height metrics are a

  3. Wind-Driven Waves in Tampa Bay, Florida

    Science.gov (United States)

    Gilbert, S. A.; Meyers, S. D.; Luther, M. E.

    2002-12-01

    Turbidity and nutrient flux due to sediment resuspension by waves and currents are important factors controlling water quality in Tampa Bay. During December 2001 and January 2002, four Sea Bird Electronics SeaGauge wave and tide recorders were deployed in Tampa Bay in each major bay segment. Since May 2002, a SeaGauge has been continuously deployed at a site in middle Tampa Bay as a component of the Bay Regional Atmospheric Chemistry Experiment (BRACE). Initial results for the summer 2002 data indicate that significant wave height is linearly dependent on wind speed and direction over a range of 1 to 12 m/s. The data were divided into four groups according to wind direction. Wave height dependence on wind speed was examined for each group. Both northeasterly and southwesterly winds force significant wave heights that are about 30% larger than those for northwesterly and southeasterly winds. This difference is explained by variations in fetch due to basin shape. Comparisons are made between these observations and the results of a SWAN-based model of Tampa Bay. The SWAN wave model is coupled to a three-dimensional circulation model and computes wave spectra at each model grid cell under observed wind conditions and modeled water velocity. When SWAN is run without dissipation, the model results are generally similar in wave period but about 25%-50% higher in significant wave height than the observations. The impact of various dissipation mechanisms such as bottom drag and whitecapping on the wave state is being investigated. Preliminary analyses on winter data give similar results.

  4. Study and Evaluation of Ultrasound System for Detecting the Height of Corn Canopy

    Directory of Open Access Journals (Sweden)

    T Mesri Gundoshmian

    2017-10-01

    Full Text Available Introduction Growth of population, deficiency of resources, environmental hazards, fast spatial science progress and relevant subjects have resulted in significant effects of enhanced accuracy and modern technologies in agricultural technology and management methods. One of the modern technologies’ utilities in production and nondestructive tests is determination of product characteristics (such as product height, using electronic sensors at different stages of plant growth. In recent years, electric sensors improved widely in farm science. Regarding to wide performance of sensors, from simple sensors such as thermo, light and moisture sensors, to complex ones such as GPS and lidar, also the ability of electronic sensors to exact identification and measurement of special farm properties, makes these sensors to an important part of precision agriculture. The subject of this study is to identify and measure the height of the product using ultrasonic technology to automate control of breeding and harvesting operations. Suitable price and noise and dust resistance of ultrasonic sensor, make it an attractive subject in biosystem industries and farm operations. Materials and Methods Plant height measurement Ultrasonic sensor includes an ultrasonic transmitter and receiver with more than 20 kHz frequency. As other waves, ultrasonic waves diffuse constantly from a source by mechanical distracting in a gas, liquid or solid environment. The distance between sensor and object is a function of the wave passing time from generation point to receive point. Plant height calculated by estimating this distance and minus it from sensor height. The sensor used in this research had a diffuse angle of 40 degrees to center axis of source. The sensor ability to height measurement depends on leaves angle, leaves surface, plant aggregation in area and plant height. Leaves angle is the most important factor in recognization ability of ultrasonic sensor. Electronic

  5. Waves in the Red Sea: Response to monsoonal and mountain gap winds

    KAUST Repository

    Ralston, David K.

    2013-08-01

    An unstructured grid, phase-averaged wave model forced with winds from a high resolution atmospheric model is used to evaluate wind wave conditions in the Red Sea over an approximately 2-year period. The Red Sea lies in a narrow rift valley, and the steep topography surrounding the basin steers the dominant wind patterns and consequently the wave climate. At large scales, the model results indicated that the primary seasonal variability in waves was due to the monsoonal wind reversal. During the winter, monsoon winds from the southeast generated waves with mean significant wave heights in excess of 2. m and mean periods of 8. s in the southern Red Sea, while in the northern part of the basin waves were smaller, shorter period, and from northwest. The zone of convergence of winds and waves typically occurred around 19-20°N, but the location varied between 15 and 21.5°N. During the summer, waves were generally smaller and from the northwest over most of the basin. While the seasonal winds oriented along the axis of the Red Sea drove much of the variability in the waves, the maximum wave heights in the simulations were not due to the monsoonal winds but instead were generated by localized mountain wind jets oriented across the basin (roughly east-west). During the summer, a mountain wind jet from the Tokar Gap enhanced the waves in the region of 18 and 20°N, with monthly mean wave heights exceeding 2. m and maximum wave heights of 14. m during a period when the rest of the Red Sea was relatively calm. Smaller mountain gap wind jets along the northeast coast created large waves during the fall and winter, with a series of jets providing a dominant source of wave energy during these periods. Evaluation of the wave model results against observations from a buoy and satellites found that the spatial resolution of the wind model significantly affected the quality of the wave model results. Wind forcing from a 10-km grid produced higher skills for waves than winds from a

  6. Regional Wave Climates along Eastern Boundary Currents

    Science.gov (United States)

    Semedo, Alvaro; Soares, Pedro

    2016-04-01

    Two types of wind-generated gravity waves coexist at the ocean surface: wind sea and swell. Wind sea waves are waves under growing process. These young growing waves receive energy from the overlaying wind and are strongly coupled to the local wind field. Waves that propagate away from their generation area and no longer receive energy input from the local wind are called swell. Swell waves can travel long distances across entire ocean basins. A qualitative study of the ocean waves from a locally vs. remotely generation perspective is important, since the air sea interaction processes is strongly modulated by waves and vary accordingly to the prevalence of wind sea or swell waves in the area. A detailed climatology of wind sea and swell waves along eastern boundary currents (EBC; California Current, Canary Current, in the Northern Hemisphere, and Humboldt Current, Benguela Current, and Western Australia Current, in the Southern Hemisphere), based on the ECMWF (European Centre for Medium-Range Weather Forecasts) ERA-Interim reanalysis will be presented. The wind regime along EBC varies significantly from winter to summer. The high summer wind speeds along EBC generate higher locally generated wind sea waves, whereas lower winter wind speeds in these areas, along with stronger winter extratropical storms far away, lead to a predominance of swell waves there. In summer, the coast parallel winds also interact with coastal headlands, increasing the wind speed through a process called "expansion fan", which leads to an increase in the height of locally generated waves downwind of capes and points. Hence the spatial patterns of the wind sea or swell regional wave fields are shown to be different from the open ocean along EBC, due to coastal geometry and fetch dimensions. Swell waves will be shown to be considerably more prevalent and to carry more energy in winter along EBC, while in summer locally generated wind sea waves are either more comparable to swell waves or

  7. South America, Shaded Relief and Colored Height

    Science.gov (United States)

    2003-01-01

    occurrence of simple erosional processes acting upon fairly uniform bedrock. Very smooth plateaus here are remnants of landforms most likely developed under geologic and environmental conditions much different than those present today. Fractures paralleling the coast are likely related to the opening of the Atlantic Ocean as South America drifted away from Africa, starting about 130 million years ago.To the southwest, broad lowlands host the Gran Chaco and Pampas regions. The depositional Gran Chaco drainages run almost exclusively from west to east from the Andes Mountains to the western edge of the Brazilian Highlands as a result of the much greater sediment supply from the Andes. Geologic processes on the Pampas are much more diverse, with stream erosion, stream deposition, subsidence, and wind processes all evident, even at the one-kilometer resolution shown here.Further south, Patagonia also displays these geologic processes plus more prominent volcanic features, including bumpy mesas, which are lava plateaus with small (and some large) volcanic cones. At its southern tip South America breaks into islands that include Tierra del Fuego and the Straits of Magellan.Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations.Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of

  8. Impact of Wave Dragon on Wave Climate

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Tedd, James; Kramer, Morten

    This report is an advisory paper for use in determining the wave dragon effects on hydrography, by considering the effect on the wave climate in the region of a wave dragon. This is to be used in the impact assessment for the Wave Dragon pre-commercial demonstrator.......This report is an advisory paper for use in determining the wave dragon effects on hydrography, by considering the effect on the wave climate in the region of a wave dragon. This is to be used in the impact assessment for the Wave Dragon pre-commercial demonstrator....

  9. Wave energy

    Energy Technology Data Exchange (ETDEWEB)

    Whittaker, T.J.T. (Queen' s Univ., Belfast, Northern Ireland (UK)); White, P.R.S. (Lanchester Polytechnic, Coventry (UK)); Baker, A.C.J. (Binnie and Partners, London (UK))

    1988-10-01

    An informal discussion on various wave energy converters is reported. These included a prototype oscillating water column (OWC) device being built on the Isle of Islay in Scotland; the SEA Clam; a tapering channel device (Tapchan) raising incoming waves into a lagoon on a Norwegian island and an OWC device on the same island. The Norwegian devices are delivering electricity at about 5.5p/KWh and 4p/KWh respectively with possibilities for reduction to 2.5-3p/KWh and 3p/KWh under favourable circumstances. The discussion ranged over comparisons with progress in wind power, engineering aspects, differences between inshore and offshore devices, tidal range and energy storage. (UK).

  10. Gravitational waves

    CERN Document Server

    Ciufolini, I; Moschella, U; Fre, P

    2001-01-01

    Gravitational waves (GWs) are a hot topic and promise to play a central role in astrophysics, cosmology, and theoretical physics. Technological developments have led us to the brink of their direct observation, which could become a reality in the coming years. The direct observation of GWs will open an entirely new field: GW astronomy. This is expected to bring a revolution in our knowledge of the universe by allowing the observation of previously unseen phenomena, such as the coalescence of compact objects (neutron stars and black holes), the fall of stars into supermassive black holes, stellar core collapses, big-bang relics, and the new and unexpected.With a wide range of contributions by leading scientists in the field, Gravitational Waves covers topics such as the basics of GWs, various advanced topics, GW detectors, astrophysics of GW sources, numerical applications, and several recent theoretical developments. The material is written at a level suitable for postgraduate students entering the field.

  11. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Frigaard, Peter; Brorsen, Michael

    Nærværende rapport beskriver foreløbige hovedkonklusioner på modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star i perioden 13/9 2004 til 12/11 2004.......Nærværende rapport beskriver foreløbige hovedkonklusioner på modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star i perioden 13/9 2004 til 12/11 2004....

  12. Shock Waves

    CERN Document Server

    Jiang, Z

    2005-01-01

    The International Symposium on Shock Waves (ISSW) is a well established series of conferences held every two years in a different location. A unique feature of the ISSW is the emphasis on bridging the gap between physicists and engineers working in fields as different as gas dynamics, fluid mechanics and materials sciences. The main results presented at these meetings constitute valuable proceedings that offer anyone working in this field an authoritative and comprehensive source of reference.

  13. Simulation of Irregular Waves and Wave Induced Loads on Wind Power Plants in Shallow Water

    Energy Technology Data Exchange (ETDEWEB)

    Trumars, Jenny [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Water Environment Transport

    2004-05-01

    The essay gives a short introduction to waves and discusses the problem with non-linear waves in shallow water and how they effect an offshore wind energy converter. The focus is on the realisation of non-linear waves in the time domain from short-term statistics in the form of a variance density spectrum of the wave elevation. For this purpose the wave transformation from deep water to the near to shore site of a wind energy farm at Bockstigen has been calculated with the use of SWAN (Simulating Waves Near Shore). The result is a wave spectrum, which can be used as input to the realisation. The realisation of waves is done by perturbation theory to the first and second-order. The properties calculated are the wave elevation, water particle velocity and acceleration. The wave heights from the second order perturbation equations are higher than those from the first order perturbation equations. This is also the case for the water particle kinematics. The increase of variance is significant between the first order and the second order realisation. The calculated wave elevation exhibits non-linear features as the peaks become sharper and the troughs flatter. The resulting forces are calculated using Morison's equation. For second order force and base moment there is an increase in the maximum values. The force and base moment are largest approximately at the zero up and down crossing of the wave elevation. This indicates an inertia dominated wave load. So far the flexibility and the response of the structure have not been taken into account. They are, however, of vital importance. For verification of the wave model the results will later on be compared with measurements at Bockstigen off the coast of Gotland in the Baltic Sea.

  14. Breather Rogue Waves in Random Seas

    Science.gov (United States)

    Wang, J.; Ma, Q. W.; Yan, S.; Chabchoub, A.

    2018-01-01

    Rogue or freak waves are extreme wave events that have heights exceeding 8 times the standard deviation of surrounding waves and emerge, for instance, in the ocean as well as in other physical dispersive wave guides, such as in optical fibers. One effective and convenient way to model such an extreme dynamics in laboratory environments within a controlled framework as well as for short process time and length scales is provided through the breather formalism. Breathers are pulsating localized structures known to model extreme waves in several nonlinear dispersive media in which the initial underlying process is assumed to be narrow banded. On the other hand, several recent studies suggest that breathers can also persist in more complex environments, such as in random seas, beyond the attributed physical limitations. In this work, we study the robustness of the Peregrine breather (PB) embedded in Joint North Sea Wave Project (JONSWAP) configurations using fully nonlinear hydrodynamic numerical simulations in order to validate its practicalness for ocean engineering applications. We provide a specific range for both the spectral bandwidth of the dynamical process as well as the background wave steepness and, thus, quantify the applicability of the PB in modeling rogue waves in realistic oceanic conditions. Our results may motivate analogous studies in fields of physics such as optics and plasma to quantify the limitations of exact weakly nonlinear models, such as solitons and breathers, within the framework of the fully nonlinear governing equations of the corresponding medium.

  15. Wave power for La Isla Bonita

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias, G.; Carballo, R. [Univ. of Santiago de Compostela, Hydraulic Eng., EPS, Campus Univ. s/n, 27002 Lugo (Spain)

    2010-12-15

    The island of La Palma (Spain), dubbed La Isla Bonita for its beauty, is a UNESCO Biosphere Reserve in the Atlantic Ocean. The island's authorities are aiming for energy self-sufficiency based on wave energy and other renewables. In this research its wave resource is investigated using a 44-years hindcast dataset obtained through numerical modelling and validated with wave buoy records. First, its distribution around La Palma is studied. Significant variations are found, with the largest resource occurring off the north and northwest coasts; the northwest presents operational advantages (proximity to a port). Second, the seasonal variations in this area are studied. Wave energy is provided essentially by powerful NNW-NW swells in winter and autumn, by less energetic NNE-N waves in summer and spring. Finally, the resource is characterised in terms of sea states; it is found that the bulk of the energy is provided by waves between 9.5 s and 13.5 s of energy period and 1.5 m and 3.5 m of significant wave height, so the selection of the Wave Energy Converters to be installed should guarantee maximum efficiency in these ranges. (author)

  16. Heights of Coronal Mass Ejections and Shocks Inferred from Metric and DH Type II Radio Bursts

    Science.gov (United States)

    Shanmugaraju, A.; Bendict Lawrance, M.; Moon, Y. J.; Lee, Jae-Ok; Suresh, K.

    2017-09-01

    A set of 27 continuous events that showed extension of metric Type-II radio bursts (m-Type IIs) into the deca-hectometric (DH) domain is considered. The coronal mass ejections (CMEs) associated with this type of continuous event supply more energy to produce space-weather effects than the CMEs that produce Type-II bursts in any one region. Since the heights of shock formation at the start of m-Type IIs were not available from observations, they were estimated using kinematic modeling in previous studies. In the present study, the heights of shock formation during metric and DH Type-II bursts are determined using two methods: i) the CME leading-edge method and ii) a method employing known electron-density models and start/end frequencies. In the first method, assuming that the shocks are generated by the associated CMEs at the leading edge, the height of the CME leading edge (LE) is calculated at the onset and end of m-Type IIs using the kinematic equation with constant acceleration or constant speed. The LE heights of CMEs that are assumed to be the heights of shock formation/end of nearly 79% of m-Type IIs are found to be within the acceptable range of 1 - 3 R_{⊙}. For other events, the heights are beyond this range, for which the shocks might either have been generated at the CME flanks/flare-blast waves, or the initial CME height might have been different. The CME/shock height at the onset and end of 17 DH Type IIs are found to be in the range of 2 - 6 R_{⊙} and within 30 R_{⊙}, respectively. In addition, the CME LE heights from observations at the onset and end of metric/DH Type IIs are compared with the heights corresponding to the observed frequency that is determined using the known electron-density models, and they are in agreement with the model results. The heights are also estimated using the space speed available for 15 halo CMEs, and it is found that the difference is smaller at the m-Type II start/end (0.02 to 0.66 R_{⊙}) and slightly greater

  17. Modeling the Buoyancy System of a Wave Energy Power Plant

    DEFF Research Database (Denmark)

    Pedersen, Tom S.; Nielsen, Kirsten M.

    2009-01-01

    A nonlinear dynamic model of the buoyancy system in a wave energy power plant is presented. The plant ("Wave Dragon") is a floating device using the potential energy in overtopping waves to produce power. A water reservoir is placed on top of the WD, and hydro turbines lead the water to the sea...... producing electrical power. Through air chambers it is possible to control the level of the WD. It is important to control the level in order to maximize the power production in proportion to the wave height, here the amount of overtopping water and the amount of potential energy is conflicting...

  18. Effect of firing conditions & release height on terminal performance of submunitions and conditions for optimum height of release

    Directory of Open Access Journals (Sweden)

    L.K. Gite

    2017-06-01

    Full Text Available Submunitions should exhibit optimum terminal performance at target end when released from certain pre-determined height. Selection of an optimum height of release of the submunitions depends on the terminal parameters like forward throw, remaining velocity, impact angle and flight time. In this paper, the effects of initial firing conditions and height of release on terminal performance of submunitions discussed in detail. For different height of release, the relation between range and forward throw is also established & validated for a number of firing altitude and rocket configurations.

  19. An attempt to link the Brazilian Height System to a World Height System

    Directory of Open Access Journals (Sweden)

    V. G. Ferreira

    Full Text Available This paper deals with the geopotential approach to investigate the present Brazilian Height System (BHS. Geopotential numbers are derived from Global Positioning System (GPS satellite surveying and disturbing potential on selected benchmarks. A model for the disturbing potential can be obtained by an existing set of spherical harmonic coefficients such as the Earth Gravity Model 2008 (EGM08. The approach provides absolute evaluation of local normal geopotential numbers (aka spheropotential numbers related to a so-called World Height System (WHS. To test the validity of the proposed methodology, a numerical experiment was carried out related to a test region in Southern Brazil. The accuracy of the derived geopotential numbers was tested versus local normal geopotential numbers based on 262 GPS/leveling points. The root mean square error (RMSE value for metric offset of BHS derived from geopotential numbers and the disturbing potential modeling in the test area was estimated to be near 0.224 meters in the absolute view. Therefore, since these spheropotential numbers are referred to a local datum, these results of comparisons may be an indicator of the mean bias of local network due to the effect of local Sea Surface Topography (SSTop and possible offset between the unknown reference for the BHS and the quasigeoid model in the region.

  20. CMS-Wave

    Science.gov (United States)

    2015-10-30

    Coastal Inlets Research Program CMS -Wave CMS -Wave is a two-dimensional spectral wind-wave generation and transformation model that employs a forward...marching, finite-difference method to solve the wave action conservation equation. Capabilities of CMS -Wave include wave shoaling, refraction... CMS -Wave can be used in either on a half- or full-plane mode, with primary waves propagating from the seaward boundary toward shore. It can

  1. Dark and composite rogue waves in the coupled Hirota equations

    International Nuclear Information System (INIS)

    Chen, Shihua

    2014-01-01

    The intriguing dark and composite rogue wave dynamics in a coupled Hirota system are unveiled, based on the exact explicit rational solutions obtained under the assumption of equal background height. It is found that a dark rogue wave state would occur as a result of the strong coupling between two field components with large wavenumber difference, and there would appear plenty of composite structures that are attributed to the specific wavenumber difference and the free choice of three independent structural parameters. The coexistence of different fundamental rogue waves in such a coupled system is also demonstrated. - Highlights: • Exact rational rogue wave solutions under different parameter conditions are presented for the coupled Hirota equations. • The basic rogue wave features and hence the intriguing dark structures are unveiled. • We attributed the diversity of composite rogue wave dynamics to the free choice of three independent structural parameters. • The remarkable coexisting rogue wave behaviors in such a coupled system are demonstrated

  2. Predicting Boat-Generated Wave Heights: A Quantitative Analysis through Video Observations of Vessel Wakes

    Science.gov (United States)

    2012-05-18

    study, a 26ft Uniflite Cruiser was driven along Broad Creek (in Anne Arundel County, MD) at various distances from the shoreline for a range of...guidance were crucial to the experimental and testing phase of the project. To my roommates over the duration of the project: Aaron Nowlin, Terrell ...1980) “The role of boat wakes in shore erosion in Anne Arundel County, Maryland.” Maryland Department of Natural Resources. Zhang, S., Qi, Z

  3. Spatial and temporal variations of wave height in shelf seas around India

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; Anoop, T.R.

    Science20; 87-92. Dee DP, Uppala SM, Simmons AJ, Berrisford P, Poli P, Kobayashi S, Andrae U, Balmaseda MA, Balsamo G, Bauer P, Bechtold P, Beljaars ACM, van de Berg L, Bidlot J, Bormann N, Delsol C, Dragani R, Fuentes M, Geer AJ, Haimberger L, Healy SB..., Hersbach H, Hólm EV, Isaksen L, Kållberg P, Köhler M, Matricardi M, McNally AP, Monge-Sanz BM, Morcrette J-J, Park B-K, Peubey C, de Rosnay P, Tavolato C, Thépaut J-N, Vitart F (2011) The ERA-Interim reanalysis: configuration and performance of the data...

  4. Kinematics and dynamics of green water on a fixed platform in a large wave basin in focusing wave and random wave conditions

    Science.gov (United States)

    Chuang, Wei-Liang; Chang, Kuang-An; Mercier, Richard

    2018-06-01

    Green water kinematics and dynamics due to wave impingements on a simplified geometry, fixed platform were experimentally investigated in a large, deep-water wave basin. Both plane focusing waves and random waves were employed in the generation of green water. The focusing wave condition was designed to create two consecutive plunging breaking waves with one impinging on the frontal vertical wall of the fixed platform, referred as wall impingement, and the other directly impinging on the deck surface, referred as deck impingement. The random wave condition was generated using the JONSWAP spectrum with a significant wave height approximately equal to the freeboard. A total of 179 green water events were collected in the random wave condition. By examining the green water events in random waves, three different flow types are categorized: collapse of overtopping wave, fall of bulk water, and breaking wave crest. The aerated flow velocity was measured using bubble image velocimetry, while the void fraction was measured using fiber optic reflectometry. For the plane focusing wave condition, measurements of impact pressure were synchronized with the flow velocity and void fraction measurements. The relationship between the peak pressures and the pressure rise times is examined. For the high-intensity impact in the deck impingement events, the peak pressures are observed to be proportional to the aeration levels. The maximum horizontal velocities in the green water events in random waves are well represented by the lognormal distribution. Ritter's solution is shown to quantitatively describe the green water velocity distributions under both the focusing wave condition and the random wave condition. A prediction equation for green water velocity distribution under random waves is proposed.

  5. Modeling of the height control system using artificial neural networks

    Directory of Open Access Journals (Sweden)

    A. R Tahavvor

    2016-09-01

    Full Text Available Introduction Automation of agricultural and machinery construction has generally been enhanced by intelligent control systems due to utility and efficiency rising, ease of use, profitability and upgrading according to market demand. A broad variety of industrial merchandise are now supplied with computerized control systems of earth moving processes to be performed by construction and agriculture field vehicle such as grader, backhoe, tractor and scraper machines. A height control machine which is used in measuring base thickness is consisted of two mechanical and electronic parts. The mechanical part is consisted of conveyor belt, main body, electrical engine and invertors while the electronic part is consisted of ultrasonic, wave transmitter and receiver sensor, electronic board, control set, and microcontroller. The main job of these controlling devices consists of the topographic surveying, cutting and filling of elevated and spotted low area, and these actions fundamentally dependent onthe machine's ability in elevation and thickness measurement and control. In this study, machine was first tested and then some experiments were conducted for data collection. Study of system modeling in artificial neural networks (ANN was done for measuring, controlling the height for bases by input variable input vectors such as sampling time, probe speed, conveyer speed, sound wave speed and speed sensor are finally the maximum and minimum probe output vector on various conditions. The result reveals the capability of this procedure for experimental recognition of sensors' behavior and improvement of field machine control systems. Inspection, calibration and response, diagnosis of the elevation control system in combination with machine function can also be evaluated by some extra development of this system. Materials and Methods Designing and manufacture of the planned apparatus classified in three dissimilar, mechanical and electronic module, courses of

  6. Measuring perceived ceiling height in a visual comparison task.

    Science.gov (United States)

    von Castell, Christoph; Hecht, Heiko; Oberfeld, Daniel

    2017-03-01

    When judging interior space, a dark ceiling is judged to be lower than a light ceiling. The method of metric judgments (e.g., on a centimetre scale) that has typically been used in such tasks may reflect a genuine perceptual effect or it may reflect a cognitively mediated impression. We employed a height-matching method in which perceived ceiling height had to be matched with an adjustable pillar, thus obtaining psychometric functions that allowed for an estimation of the point of subjective equality (PSE) and the difference limen (DL). The height-matching method developed in this paper allows for a direct visual match and does not require metric judgment. It has the added advantage of providing superior precision. Experiment 1 used ceiling heights between 2.90 m and 3.00 m. The PSE proved sensitive to slight changes in perceived ceiling height. The DL was about 3% of the physical ceiling height. Experiment 2 found similar results for lower (2.30 m to 2.50 m) and higher (3.30 m to 3.50 m) ceilings. In Experiment 3, we additionally varied ceiling lightness (light grey vs. dark grey). The height matches showed that the light ceiling appeared significantly higher than the darker ceiling. We therefore attribute the influence of ceiling lightness on perceived ceiling height to a direct perceptual rather than a cognitive effect.

  7. Oxygen–induced barrier height changes in aluminium – amorphous ...

    African Journals Online (AJOL)

    The results show that the application of voltage causes charge exchange between the surface states and the semiconductor leading to a change in the height of the potential barrier for electrons passing from aluminium into the a-Se films. The empirically determined values of barrier height of Al/a-Se diodes with thin and ...

  8. Diagnosis of childhood hypertension: is blood pressure height ratio ...

    African Journals Online (AJOL)

    Blood pressure was also recorded according to the standard method. Systolic and diastolic blood pressure to height ratio were then calculated. Receiver operating curves was used to assess the ability of systolic blood and diastolic blood pressure height ratio to discriminate childhood prehypertension and hypertension.

  9. 17 Years of Cloud Heights from Terra, and Beyond

    Science.gov (United States)

    Davies, R.

    2017-12-01

    The effective cloud height, H, is the integral of observed cloud-top heights, weighted by their frequency of occurrence. Here we look at changes in the effective cloud height, H', as measured by the Multiangle Imaging Spectroradiometer (MISR) on the first Earth Observing System platform, Terra. Terra was launched in December 1999, and now has over 17 years of consistently measured climate records. Globally, HG' has an important influence on Earth's climate, whereas regionally, HR' is a useful measure of low frequency changes in circulation patterns. MISR has a sampling error in the annual mean HG' of ≈11 m, allowing fairly small interannual variations to be detected. This paper extends the previous 15-year summary that showed significant differences in the long term mean hemispheric cloud height changes. Also of interest are the correlations in tropical cloud height changes and related teleconnections. The largest ephemeral values in the annual HR' [over 1.5 km] are noted over the Central Pacific and the Maritime Continent. These changes are strongly anticorrelated with each other, being directly related to changes in ENSO. They are also correlated with the largest ephemeral changes in HG'. Around the equator, we find at least four distinct centres of similar fluctuations in cloud height. This paper examines the relative time dependence of these regional height changes, separately for La Niña and El Niño events, and stresses the value of extending the time series of uniformly measured cloud heights from space beyond EOS-Terra.

  10. Developmental decline in height growth in Douglas-fir.

    Science.gov (United States)

    Barbara J. Bond; Nicole M. Czarnomski; Clifton Cooper; Michael E. Day; Michael S. Greenwood

    2007-01-01

    The characteristic decline in height growth that occurs over a tree's lifespan is often called "age-related decline." But is the reduction in height growth in aging trees a function of age or of size? We grafted shoot tips across different ages and sizes of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees to determine whether...

  11. Stereoscopic Roadside Curb Height Measurement using V-Disparity

    DEFF Research Database (Denmark)

    Matu, Florin-Octavian; Vlaykov, Iskren; Thøgersen, Mikkel

    2014-01-01

    Managing road assets, such as roadside curbs, is one of the interests of municipalities. As an interesting application of computer vision, this paper proposes a system for automated measurement of the height of the roadside curbs. The developed system uses the spatial information available...... results show that the system can measure the height of the roadside curb with good accuracy and precision....

  12. A century of trends in adult human height

    DEFF Research Database (Denmark)

    Damsgaard, Camilla Trab; Michaelsen, Kim F.; Molbo, Drude

    2016-01-01

    the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8-144.8). The height differential between the tallest...

  13. human pelvis height is associated with other pelvis measurements

    African Journals Online (AJOL)

    guyton2

    no study seeking to relate pelvis height to the other pelvis measurements of obstetric importance in Ugandans. In this paper we set out to answer the research question what are the associations between the various pelvis anthropometric measurements of obstetric importance with pelvis height in a sample of bones from the ...

  14. Generalized height-diameter models for Populus tremula L. stands

    African Journals Online (AJOL)

    USER

    2010-07-12

    Jul 12, 2010 ... and stand density) into the base height-diameter models increased the accuracy of prediction for P. tremula. .... parameter estimates compared with those obtained with ... using coefficient of determination for non-linear regression (. 2. R ), ..... stochastic height-diameter model for maritime pine ecoregions in.

  15. Height among Women is Curvilinearly Related to Life History Strategy

    Directory of Open Access Journals (Sweden)

    Abraham P. Buunk

    2009-10-01

    Full Text Available It was hypothesized that women of medium height would show a more secure, long-term mating pattern characterized by less jealousy, less intrasexual competition and a “slower” life history strategy. In three samples of female undergraduate students clear support was found for these hypotheses. In Study 1, among 120 participants, height was curvilinearly related to well-established measures of possessive and reactive jealousy, with women of medium height being less jealous than tall as well as short women. In Study 2, among 40 participants, height was curvilinearly related to intrasexual competition, with women of medium height being less competitive towards other women than tall as well as short women. In Study 3, among 299 participants, height was curvilinearly related to the Mini-K, a well-validated measure of “slower” life history strategy, with women of medium height having a slower life history strategy than tall as well as short women. The results suggest that women of medium height tend to follow a different mating strategy than either tall or short women. Various explanations and implications of these results are discussed.

  16. A century of trends in adult human height

    NARCIS (Netherlands)

    Bentham, J. (James); Di Cesare, M. (Mariachiara); Stevens, G.A. (Gretchen A.); Zhou, B. (Bin); Bixby, H. (Honor); Cowan, M. (Melanie); Fortunato, L. (Léa); Bennett, J.E. (James E.); G. Danaei (Goodarz); Hajifathalian, K. (Kaveh); Lu, Y. (Yuan); Riley, L.M. (Leanne M.); Laxmaiah, A. (Avula); Kontis, V. (Vasilis); Paciorek, C.J. (Christopher J.); M. Ezzati (Majid); Abdeen, Z.A. (Ziad A.); Hamid, Z.A. (Zargar Abdul); Abu-Rmeileh, N.M. (Niveen M.); Acosta-Cazares, B. (Benjamin); Adams, R. (Robert); Aekplakorn, W. (Wichai); C.A. Aguilar-Salinas (Carlos A.); C.O. Agyemang (Charles); Ahmadvand, A. (Alireza); W. Ahrens (W.); Al-Hazzaa, H.M. (Hazzaa M.); Al-Othman, A.R. (Amani Rashed); Raddadi, R.A. (Rajaa Al); Ali, M.M. (Mohamed M.); Alkerwi, A. (Ala’a); M. Alvarez-Pedrerol (Mar); Aly, E. (Eman); P. Amouyel (Philippe); A. Amuzu (Antoinette); Andersen, L.B. (Lars Bo); Anderssen, S.A. (Sigmund A.); Anjana, R.M. (Ranjit Mohan); Aounallah-Skhiri, H. (Hajer); Ariansen, I. (Inger); Aris, T. (Tahir); Arlappa, N. (Nimmathota); Arveiler, D. (Dominique); Assah, F.K. (Felix K.); Avdicová, M. (Mária); J. Azizi (Joshan); Babu, B.V. (Bontha V.); Bahijri, S. (Suhad); Balakrishna, N. (Nagalla); Bandosz, P. (Piotr); Banegas, J.R. (José R.); Barbagallo, C.M. (Carlo M.); Barceló, A. (Alberto); Barkat, A. (Amina); Barros, M.V. (Mauro V.); Bata, I. (Iqbal); Batieha, A.M. (Anwar M.); Batista, R.L. (Rosangela L.); Baur, L.A. (Louise A.); Beaglehole, R. (Robert); Romdhane, H.B. (Habiba Ben); Benet, M. (Mikhail); Bernabe-Ortiz, A. (Antonio); Bernotiene, G. (Gailute); Bettiol, H. (Heloisa); Bhagyalaxmi, A. (Aroor); Bharadwaj, S. (Sumit); Bhargava, S.K. (Santosh K.); Bhatti, Z. (Zaid); Z.A. Bhutta (Zulfiqar A); Bi, H. (Hongsheng); Bi, Y. (Yufang); Bjerregaard, P. (Peter); Bjertness, E. (Espen); Bjertness, M.B. (Marius B.); Björkelund, C. (Cecilia); Blokstra, A. (Anneke); Bo, S. (Simona); M. Bobak (Martin); Boddy, L.M. (Lynne M.); B.O. Boehm (Bernhard); H. Boeing (Heiner); Boissonnet, C.P. (Carlos P.); Bongard, V. (Vanina); P. Bovet (Pascal); Braeckman, L. (Lutgart); Bragt, M.C.E. (Marjolijn C. E.); Brajkovich, I. (Imperia); Branca, F. (Francesco); Breckenkamp, J. (Juergen); H. Brenner (Hermann); L.M. Brewster (Lizzy); Brian, G.R. (Garry R.); Bruno, G. (Graziella); Bueno-de-Mesquita, H.B. (H. Bas); Bugge, A. (Anna); Burns, C. (Con); De León, A.C. (Antonio Cabrera); Cacciottolo, J. (Joseph); Cama, T. (Tilema); Cameron, C. (Christine); Camolas, J. (José); G. Can (Günay); Cândido, A.P.C. (Ana Paula C.); Capuano, V. (Vincenzo); Cardoso, V.C. (Viviane C.); Carlsson, A.C. (Axel C.); Carvalho, M.J. (Maria J.); Casanueva, F.F. (Felipe F.); J.P. Casas (Juan Pablo); Caserta, C.A. (Carmelo A.); Chamukuttan, S. (Snehalatha); A.W.M. Chan (Angelique); Chan, Q. (Queenie); Chaturvedi, H.K. (Himanshu K.); Chaturvedi, N. (Nishi); Chen, C.-J. (Chien-Jen); Chen, F. (Fangfang); Chen, H. (Huashuai); Chen, S. (Shuohua); Chen, Z. (Zhengming); Cheng, C.-Y. (Ching-Yu); A. Chetrit (Angela); Chiolero, A. (Arnaud); Chiou, S.-T. (Shu-Ti); Chirita-Emandi, A. (Adela); Cho, B. (Belong); Cho, Y. (Yumi); Christensen, K. (Kaare); Chudek, J. (Jerzy); R. Cifkova (Renata); F. Claessens; E. Clays (Els); Concin, H. (Hans); C. Cooper (Charles); Cooper, R. (Rachel); Coppinger, T.C. (Tara C.); Costanzo, S. (Simona); D. Cottel (Dominique); Cowell, C. (Chris); Craig, C.L. (Cora L.); Crujeiras, A.B. (Ana B.); D’Arrigo, G. (Graziella); d’Orsi, E. (Eleonora); J. Dallongeville; Damasceno, A. (Albertino); Damsgaard, C.T. (Camilla T.); Dankner, R. (Rachel); Dauchet, L. (Luc); G. De Backer (Guy); D. De Bacquer (Dirk); de Gaetano, G. (Giovanni); De Henauw, S. (Stefaan); D. De Smedt (Delphine); Deepa, M. (Mohan); Deev, A.D. (Alexander D.); A. Dehghan (Abbas); Delisle, H. (Hélène); Delpeuch, F. (Francis); Deschamps, V. (Valérie); K. Dhana (Klodian); Di Castelnuovo, A.F. (Augusto F.); Dias-da-Costa, J.S. (Juvenal Soares); Diaz, A. (Alejandro); Djalalinia, S. (Shirin); Do, H.T.P. (Ha T. P.); Dobson, A.J. (Annette J.); C. Donfrancesco (Chiara); Donoso, S.P. (Silvana P.); A. Döring (Angela); Doua, K. (Kouamelan); Drygas, W. (Wojciech); Dzerve, V. (Vilnis); Egbagbe, E.E. (Eruke E.); Eggertsen, R. (Robert); U. Ekelund (Ulf); El Ati, J. (Jalila); P. Elliott (Paul); Engle-Stone, R. (Reina); Erasmus, R.T. (Rajiv T.); Erem, C. (Cihangir); Eriksen, L. (Louise); Escobedo-de la Peña, J. (Jorge); A. Evans (Alun); Faeh, D. (David); Fall, C.H. (Caroline H.); F. Farzadfar (Farshad); Felix-Redondo, F.J. (Francisco J.); Ferguson, T.S. (Trevor S.); Fernández-Bergés, D. (Daniel); Ferrante, D. (Daniel); Ferrari, M. (Marika); Ferreccio, C. (Catterina); J. Ferrieres (Jean); Finn, J.D. (Joseph D.); K. Fischer (Krista); Flores, E.M. (Eric Monterubio); Föger, B. (Bernhard); Foo, L.H. (Leng Huat); Forslund, A.-S. (Ann-Sofie); Forsner, M. (Maria); S.P. Fortmann (Stephen); Fouad, H.M. (Heba M.); Francis, D.K. (Damian K.); Do Carmo Franco, M. (Maria); O.H. Franco (Oscar); Frontera, G. (Guillermo); Fuchs, F.D. (Flavio D.); Fuchs, S.C. (Sandra C.); Fujita, Y. (Yuki); Furusawa, T. (Takuro); Gaciong, Z. (Zbigniew); Gafencu, M. (Mihai); Gareta, D. (Dickman); Garnett, S.P. (Sarah P.); J.-M. Gaspoz (Jean-Michel); Gasull, M. (Magda); Gates, L. (Louise); J.M. Geleijnse (Marianne); Ghasemian, A. (Anoosheh); S. Giampaoli (Simona); F. Gianfagna (Francesco); Giovannelli, J. (Jonathan); A. Giwercman (Aleksander); Goldsmith, R.A. (Rebecca A.); Gonçalves, H. (Helen); M. Gross; González Rivas, J.P. (Juan P.); Gorbea, M.B. (Mariano Bonet); Gottrand, F. (Frederic); Graff-Iversen, S. (Sidsel); Grafnetter, D. (Dušan); Grajda, A. (Aneta); Grammatikopoulou, M.G. (Maria G.); Gregor, R.D. (Ronald D.); T. Grodzicki (Tomasz); Grøntved, A. (Anders); Gruden, G. (Grabriella); Grujic, V. (Vera); Gu, D. (Dongfeng); Gualdi-Russo, E. (Emanuela); Guan, O.P. (Ong Peng); V. Gudnason (Vilmundur); Guerrero, R. (Ramiro); I. Guessous (Idris); Guimaraes, A.L. (Andre L.); Gulliford, M.C. (Martin C.); Gunnlaugsdottir, J. (Johanna); Gunter, M. (Marc); Guo, X. (Xiuhua); Guo, Y. (Yin); Gupta, P.C. (Prakash C.); Gureje, O. (Oye); Gurzkowska, B. (Beata); Gutierrez, L. (Laura); Gutzwiller, F. (Felix); J. Halkjær; Hambleton, I.R. (Ian R.); R. Hardy; Kumar, R.H. (Rachakulla Hari); Hata, J. (Jun); Hayes, A.J. (Alison J.); He, J. (Jiang); M.E. Hendriks (Marleen); Cadena, L.H. (Leticia Hernandez); Herrala, S. (Sauli); Heshmat, R. (Ramin); Hihtaniemi, I.T. (Ilpo Tapani); Ho, S.Y. (Sai Yin); Ho, S.C. (Suzanne C.); Hobbs, M. (Michael); Hofman, A. (Albert); Hormiga, C.M. (Claudia M.); Horta, B.L. (Bernardo L.); Houti, L. (Leila); Howitt, C. (Christina); Htay, T.T. (Thein Thein); Htet, A.S. (Aung Soe); Htike, M.M.T. (Maung Maung Than); Hu, Y. (Yonghua); A. Husseini (Abdullatif); Huu, C.N. (Chinh Nguyen); Huybrechts, I. (Inge); Hwalla, N. (Nahla); L. Iacoviello (Licia); Iannone, A.G. (Anna G.); Ibrahim, M.M. (Mohsen M.); Ikeda, N. (Nayu); M.A. Ikram (Arfan); V. Irazola (Vilma); M. Islam (Muhammad); Ivkovic, V. (Vanja); Iwasaki, M. (Masanori); Jackson, R.T. (Rod T.); Jacobs, J.M. (Jeremy M.); T.H. Jafar (Tazeen); Jamil, K.M. (Kazi M.); K. Jamrozik; Janszky, I. (Imre); Jasienska, G. (Grazyna); Jelakovic, B. (Bojan); Jiang, C.Q. (Chao Qiang); Joffres, M. (Michel); M. Johansson (Mattias); J.B. Jonas (Jost B.); T. Jorgensen (Torben); Joshi, P. (Pradeep); Juolevi, A. (Anne); Jurak, G. (Gregor); Jureša, V. (Vesna); R. Kaaks (Rudolf); Kafatos, A. (Anthony); Kalter-Leibovici, O. (Ofra); Kapantais, E. (Efthymios); Kasaeian, A. (Amir); Katz, J. (Joanne); Kaur, P. (Prabhdeep); M. Kavousi (Maryam); M. Keil (Mark); Boker, L.K. (Lital Keinan); S. Keinanen-Kiukaanniemi (Sirkka); Kelishadi, R. (Roya); H.C.G. Kemper; A.P. Kengne (Andre Pascal); Kersting, M. (Mathilde); T. Key (Tim); Y.S. Khader (Yousef Saleh); D. Khalili (Davood); Khang, Y.-H. (Young-Ho); K.-T. Khaw (Kay-Tee); Khouw, I.M.S.L. (Ilse M. S. L.); S. Kiechl (Stefan); Killewo, J. (Japhet); Kim, J. (Jeongseon); Klimont, J. (Jeannette); J. Klumbiene (Jurate); Koirala, B. (Bhawesh); Kolle, E. (Elin); P. Kolsteren (Patrick); Korrovits, P. (Paul); S. Koskinen (Seppo); Kouda, K. (Katsuyasu); Koziel, S. (Slawomir); W. Kratzer (Wolfgang); Krokstad, S. (Steinar); Kromhout, D. (Daan); Kruger, H.S. (Herculina S.); R. Kubinova; U.M. Kujala (Urho); Kula, K. (Krzysztof); Kulaga, Z. (Zbigniew); Krishna Kumar, R.; Kurjata, P. (Pawel); Kusuma, Y.S. (Yadlapalli S.); K. Kuulasmaa (Kari); Kyobutungi, C. (Catherine); Laamiri, F.Z. (Fatima Zahra); T. Laatikainen (Tiina); C. Lachat (Carl); Laid, Y. (Youcef); Lam, T.H. (Tai Hing); Landrove, O. (Orlando); Lanska, V. (Vera); Lappas, G. (Georg); Larijani, B. (Bagher); L.E. Laugsand (Lars E.); Bao, K.L.N. (Khanh Le Nguyen); Le, T.D. (Tuyen D.); Leclercq, C. (Catherine); J.J.M. Lee (Jeannette); Lee, J. (Jeonghee); T. Lehtimäki (Terho); Lekhraj, R. (Rampal); León-Muñoz, L.M. (Luz M.); Y. Li (Yanping); Lilly, C.L. (Christa L.); W.-Y. Lim (Wei-Yen); Fernanda Lima-Costa, M.; Lin, H.-H. (Hsien-Ho); X. Lin (Xu); A. Linneberg (Allan); L. Lissner (Lauren); Litwin, M. (Mieczyslaw); Liu, J. (Jing); R. Lorbeer (Roberto); P.A. Lotufo (Paulo A); Lozano, J.E. (José Eugenio); Luksiene, D. (Dalia); A. Lundqvist (Annamari); Lunet, N. (Nuno); Lytsy, P. (Per); Ma, G. (Guansheng); Ma, J. (Jun); Machado-Coelho, G.L.L. (George L. L.); Machi, S. (Suka); Maggi, S. (Stefania); D.J. Magliano; Maire, B. (Bernard); Makdisse, M. (Marcia); R. Malekzadeh (Reza); Malhotra, R. (Rahul); Rao, K.M. (Kodavanti Mallikharjuna); S. Malyutina; Y. Manios; Mann, J.I. (Jim I.); Manzato, E. (Enzo); Margozzini, P. (Paula); Markey, O. (Oonagh); P. Marques-Vidal (Pedro); J. Marrugat (Jaume); Martin-Prevel, Y. (Yves); Martorell, R. (Reynaldo); Masoodi, S.R. (Shariq R.); E.B. Mathiesen (Ellisiv); Matsha, T.E. (Tandi E.); Mazur, A. (Artur); Mbanya, J.C.N. (Jean Claude N.); McFarlane, S.R. (Shelly R.); McGarvey, S.T. (Stephen T.); McKee, M. (Martin); S. McLachlan (Stela); McLean, R.M. (Rachael M.); McNulty, B.A. (Breige A.); Yusof, S.M. (Safiah Md); Mediene-Benchekor, S. (Sounnia); A. Meirhaeghe (Aline); C. Meisinger (Christa); Menezes, A.M.B. (Ana Maria B.); Mensink, G.B.M. (Gert B. M.); Meshram, I.I. (Indrapal I.); A. Metspalu (Andres); J. Mi (Jie); K.F. Michaelsen; Mikkel, K. (Kairit); Miller, J.C. (Jody C.); Miquel, J.F. (Juan Francisco); Jaime Miranda, J.; Mišigoj-Durakovic, M. (Marjeta); Mohamed, M.K. (Mostafa K.); K. Mohammad (Kazem); Mohammadifard, N. (Noushin); V. Mohan (Viswanathan); Yusoff, M.F.M. (Muhammad Fadhli Mohd); Molbo, D. (Drude); Møller, N.C. (Niels C.); Molnár, D. (Dénes); Mondo, C.K. (Charles K.); Monterrubio, E.A. (Eric A.); Monyeki, K.D.K. (Kotsedi Daniel K.); Moreira, L.B. (Leila B.); Morejon, A. (Alain); Moreno, L.A. (Luis A.); Morgan, K. (Karen); Mortensen, E.L. (Erik Lykke); G. Moschonis; Mossakowska, M. (Malgorzata); Mostafa, A. (Aya); Mota, J. (Jorge); Motlagh, M.E. (Mohammad Esmaeel); Motta, J. (Jorge); Mu, T.T. (Thet Thet); M.L. Muiesan (Maria Lorenza); M. Müller-Nurasyid (Martina); Murphy, N. (Neil); Mursu, J. (Jaakko); Murtagh, E.M. (Elaine M.); Musa, K.I. (Kamarul Imran); Musil, V. (Vera); Nagel, G. (Gabriele); Nakamura, H. (Harunobu); Námešná, J. (Jana); Nang, E.E.K. (Ei Ei K.); M. Nangia (Monika); Nankap, M. (Martin); Narake, S. (Sameer); E.M. Navarrete-Muñoz; Neal, W.A. (William A.); Nenko, I. (Ilona); Neovius, M. (Martin); Nervi, F. (Flavio); Neuhauser, H.K. (Hannelore K.); Nguyen, N.D. (Nguyen D.); Nguyen, Q.N. (Quang Ngoc); Nieto-Martínez, R.E. (Ramfis E.); Ning, G. (Guang); T. Ninomiya (Toshiharu); Nishtar, S. (Sania); Noale, M. (Marianna); Norat, T. (Teresa); Noto, D. (Davide); Nsour, M.A. (Mohannad Al); O’Reilly, D. (Dermot); Oh, K. (Kyungwon); Olayan, I.H. (Iman H.); Olinto, M.T.A. (Maria Teresa Anselmo); Oltarzewski, M. (Maciej); Omar, M.A. (Mohd A.); A. Onat (Altan); Ordunez, P. (Pedro); Ortiz, A.P. (Ana P.); Osler, M. (Merete); Osmond, C. (Clive); Ostojic, S.M. (Sergej M.); Otero, J.A. (Johanna A.); K. Overvad (Kim); E. Owusu-Dabo (Ellis); Paccaud, F.M. (Fred Michel); Padez, C. (Cristina); Pahomova, E. (Elena); A. Pajak (Andrzej); D. Palli (Domenico); Palloni, A. (Alberto); Palmieri, L. (Luigi); S. Panda-Jonas (Songhomitra); F. Panza (Francesco); Parnell, W.R. (Winsome R.); Parsaeian, M. (Mahboubeh); Pecin, I. (Ivan); Pednekar, M.S. (Mangesh S.); P.H.M. Peeters; Peixoto, S.V. (Sergio Viana); Peltonen, M. (Markku); A. Pereira (A.); Pérez, C.M. (Cynthia M.); A. Peters; Petkeviciene, J. (Janina); Peykari, N. (Niloofar); Pham, S.T. (Son Thai); Pigeot, I. (Iris); H. Pikhart (Hynek); Pilav, A. (Aida); A. Pilotto (Alberto); Pistelli, F. (Francesco); Pitakaka, F. (Freda); Piwonska, A. (Aleksandra); Plans-Rubió, P. (Pedro); Poh, B.K. (Bee Koon); M. Porta; M.L.P. Portegies (Marileen); Poulimeneas, D. (Dimitrios); Pradeepa, R. (Rajendra); Prashant, M. (Mathur); J.F. Price (Jackie F.); Puiu, M. (Maria); M. Punab (Margus); Qasrawi, R.F. (Radwan F.); Qorbani, M. (Mostafa); Bao, T.Q. (Tran Quoc); Radic, I. (Ivana); Radisauskas, R. (Ricardas); Rahman, M.-M. (Mah-mudur); O. Raitakari (Olli); Raj, M. (Manu); Rao, S.R. (Sudha Ramachandra); Ramachandran, A. (Ambady); Ramke, J. (Jacqueline); Ramos, R. (Rafel); Rampal, S. (Sanjay); Rasmussen, F. (Finn); J. Redón (Josep); Reganit, P.F.M. (Paul Ferdinand M.); Ribeiro, R. (Robespierre); Riboli, E. (Elio); Rigo, F. (Fernando); T.F. Rinke de Wit (Tobias); Ritti-Dias, R.M. (Raphael M.); Rivera, J.A. (Juan A.); S.M. Robinson (Siân); Robitaille, C. (Cynthia); F. Rodríguez Artalejo (Fernando); Del Cristo Rodriguez-Perez, M. (María); Rodríguez-Villamizar, L.A. (Laura A.); Rojas-Martinez, R. (Rosalba); Rojroong-Wasinkul, N. (Nipa); Romaguera, D. (Dora); K. Ronkainen (Kimmo); A. Rosengren (Annika); Rouse, I. (Ian); Rubinstein, A. (Adolfo); Rühli, F.J. (Frank J.); Rui, O. (Ornelas); Ruiz-Betancourt, B.S. (Blanca Sandra); Russo Horimoto, A.R.V. (Andrea R. V.); Rutkowski, M. (Marcin); C. Sabanayagam (Charumathi); Sachdev, H.S. (Harshpal S.); Saidi, O. (Olfa); Salanave, B. (Benoit); Martinez, E.S. (Eduardo Salazar); V. Salomaa (Veikko); Salonen, J.T. (Jukka T.); M. Salvetti (Massimo); Sánchez-Abanto, J. (Jose); Sandjaja,; S. Sans (Susana); Santos, D.A. (Diana A.); Santos, O. (Osvaldo); Dos Santos, R.N. (Renata Nunes); Santos, R. (Rute); J. Saramies (Jouko); Sardinha, L.B. (Luis B.); Sarrafzadegan, N. (Nizal); Saum, K.-U. (Kai-Uwe); S. Savva; Scazufca, M. (Marcia); Rosario, A.S. (Angelika Schaffrath); Schargrodsky, H. (Herman); Schienkiewitz, A. (Anja); Schmidt, I.M. (Ida Maria); I.J.C. Schneider (Ione J C); C. Schultsz (Constance); Schutte, A.E. (Aletta E.); Sein, A.A. (Aye Aye); Sen, A. (Abhijit); Senbanjo, I.O. (Idowu O.); S.G. Sepanlou (Sadaf G); Shalnova, S.A. (Svetlana A.); Sharma, S.K. (Sanjib K.); J.E. Shaw; K. Shibuya (Kenji); Shin, D.W. (Dong Wook); Y. Shin (Youchan); R. Shiri (Rahman); R. Siantar (Rosalynn); Sibai, A.M. (Abla M.); Silva, A.M. (Antonio M.); Silva, D.A.S. (Diego Augusto Santos); Simon, M. (Mary); J. Simons (Judith); L.A. Simons (Leon); Sjostrom, M. (Michael); J. Slowikowska-Hilczer (Jolanta); Slusarczyk, P. (Przemyslaw); L. Smeeth (Liam); Smith, M.C. (Margaret C.); M.B. Snijder (Marieke); So, H.-K. (Hung-Kwan); Sobngwi, E. (Eugène); S. Söderberg (Stefan); Soekatri, M.Y.E. (Moesijanti Y. E.); Solfrizzi, V. (Vincenzo); E. Sonestedt (Emily); Song, Y. (Yi); T.I.A. Sørensen (Thorkild); Soric, M. (Maroje); Jérome, C.S. (Charles Sossa); Soumare, A. (Aicha); J.A. Staessen (Jan); Starc, G. (Gregor); Stathopoulou, M.G. (Maria G.); Staub, K. (Kaspar); Stavreski, B. (Bill); Steene-Johannessen, J. (Jostein); Stehle, P. (Peter); Stein, A.D. (Aryeh D.); Stergiou, G.S. (George S.); Stessman, J. (Jochanan); Stieber, J. (Jutta); D. Stöckl (Doris); Stocks, T. (Tanja); Stokwiszewski, J. (Jakub); Stratton, G. (Gareth); K. Stronks (Karien); Strufaldi, M.W. (Maria Wany); Sun, C.-A. (Chien-An); Sundström, J. (Johan); Sung, Y.-T. (Yn-Tz); J. Sunyer (Jordi); Suriyawongpaisal, P. (Paibul); Swinburn, B.A. (Boyd A.); Sy, R.G. (Rody G.); Szponar, L. (Lucjan); E. Shyong Tai; M.L. Tammesoo; A. Tamosiunas (Abdonas); Tang, L. (Line); Tang, X. (Xun); F. Tanser (Frank); Tao, Y. (Yong); Tarawneh, M.R. (Mohammed Rasoul); Tarp, J. (Jakob); Tarqui-Mamani, C.B. (Carolina B.); Taylor, A. (Anne); Tchibindat, F. (Félicité); Theobald, H. (Holger); L. Thijs (Lutgarde); L. Thuesen (Leif); A. Tjønneland (Anne); Tolonen, H.K. (Hanna K.); Tolstrup, J.S. (Janne S.); Topbas, M. (Murat); Topór-Madry, R. (Roman); M. Torrent (Maties); Toselli, S. (Stefania); Traissac, P. (Pierre); A. Trichopoulou (Antonia); Trichopoulos, D. (Dimitrios); Trinh, O.T.H. (Oanh T. H.); Trivedi, A. (Atul); Tshepo, L. (Lechaba); Tulloch-Reid, M.K. (Marshall K.); Tuomainen, T.-P. (Tomi-Pekka); J. Tuomilehto (Jaakko); Turley, M.L. (Maria L.); Tynelius, P. (Per); Tzotzas, T. (Themistoklis); C. Tzourio (Christophe); Ueda, P. (Peter); Ukoli, F.A.M. (Flora A. M.); Ulmer, H. (Hanno); Unal, B. (Belgin); Uusitalo, H.M.T. (Hannu M. T.); Valdivia, G. (Gonzalo); Vale, S. (Susana); D. Valvi (Damaskini); Y.T. van der Schouw (Yvonne); Van Herck, K. (Koen); Van Minh, H. (Hoang); L. van Rossem (Lenie); I. van Valkengoed (Irene); D. Vanderschueren (Dirk); D. Vanuzzo (Diego); L. Vatten (Lars); Vega, T. (Tomas); Velasquez-Melendez, G. (Gustavo); G. Veronesi (Giovanni); Monique Verschuren, W.M.; Verstraeten, R. (Roosmarijn); Victora, C.G. (Cesar G.); G. Viegi; L. Viet (Lucie); E. Viikari-Juntura (Eira); P. Vineis (Paolo); J. Vioque (Jesus); Virtanen, J.K. (Jyrki K.); S. Visvikis-Siest (Sophie); B. Viswanathan (Bharathi); P. Vollenweider (Peter); Voutilainen, S. (Sari); Vrdoljak, A. (Ana); M. Vrijheid (Martine); Wade, A.N. (Alisha N.); Wagner, A. (Aline); Walton, J. (Janette); Mohamud, W.N.W. (Wan Nazaimoon Wan); Wang, M.-D. (Ming-Dong); Wang, Q. (Qian); Y. Wang (Ying); Goya Wannamethee, S.; N.J. Wareham (Nick); Weerasekera, D. (Deepa); P.H. Whincup (Peter); Widhalm, K. (Kurt); Widyahening, I.S. (Indah S.); Wiecek, A. (Andrzej); A.H. Wijga (Alet); Wilks, R.J. (Rainford J.); J. Willeit (Johann); T. Wilsgaard (Tom); B. Wojtyniak (Bogdan); Wong, J.E. (Jyh Eiin); Wong, T.Y. (Tien Yin); Woo, J. (Jean); M. Woodward (Mark); F.C.W. Wu (Frederick C.); Wu, J. (Jianfeng); Wu, S.L. (Shou Ling); Xu, H. (Haiquan); Xu, L. (Liang); Yamborisut, U. (Uruwan); Yan, W. (Weili); Yang, X. (Xiaoguang); Yardim, N. (Nazan); X. Ye (Xingwang); P.K. Yiallouros (P.); Yoshihara, A. (Akihiro); You, Q.S. (Qi Sheng); Younger-Coleman, N.O. (Novie O.); Yusoff, A.F. (Ahmad F.); Zainuddin, A.A. (Ahmad A.); Zambon, S. (Sabina); T. Zdrojewski (T.); Zeng, Y. (Yi); Zhao, D. (Dong); Zhao, W. (Wenhua); Y. Zheng (Yingfeng); M. Zhou (Ming); Zhu, D. (Dan); E. Zimmermann; Cisneros, J.Z. (Julio Zuñiga)

    2016-01-01

    textabstractBeing taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The

  17. Variability of the Mixed-Layer Height Over Mexico City

    Science.gov (United States)

    García-Franco, J. L.; Stremme, W.; Bezanilla, A.; Ruiz-Angulo, A.; Grutter, M.

    2018-02-01

    The diurnal and seasonal variability of the mixed-layer height in urban areas has implications for ground-level air pollution and the meteorological conditions. Measurements of the backscatter of light pulses with a commercial lidar system were performed for a continuous period of almost six years between 2011 and 2016 in the southern part of Mexico City. The profiles were temporally and vertically smoothed, clouds were filtered out, and the mixed-layer height was determined with an ad hoc treatment of both the filtered and unfiltered profiles. The results are in agreement when compared with values of mixed-layer height reconstructed from, (i) radiosonde data, and (ii) surface and vertical column densities of a trace gas. The daily maxima of the mean mixed-layer height reach values > 3 km above ground level in the months of March-April, and are clearly lower (pollution episodes and the height of the mixed layer. The growth rate of the convective mixed-layer height has a seasonal behaviour, which is characterized together with the mixed-layer-height anomalies. A clear residual layer is evident from the backscattered signals recorded in days with specific atmospheric conditions, but also from the cloud-filtered mean diurnal profiles. The occasional presence of a residual layer results in an overestimation of the reported mixed-layer height during the night and early morning hours.

  18. A century of trends in adult human height

    NARCIS (Netherlands)

    Bentham, James; Di Cesare, Mariachiara; Stevens, Gretchen A.; Zhou, Bin; Bixby, Honor; Cowan, Melanie; Fortunato, Léa; Bennett, James E.; Danaei, Goodarz; Hajifathalian, Kaveh; Lu, Yuan; Riley, Leanne M.; Laxmaiah, Avula; Kontis, Vasilis; Paciorek, Christopher J.; Riboli, Elio; Ezzati, Majid; Abdeen, Ziad A.; Hamid, Zargar Abdul; Abu-Rmeileh, Niveen M.; Acosta-Cazares, Benjamin; Adams, Robert; Aekplakorn, Wichai; Aguilar-Salinas, Carlos A.; Agyemang, Charles; Ahmadvand, Alireza; Ahrens, Wolfgang; Al-Hazzaa, Hazzaa M.; Al-Othman, Amani Rashed; Raddadi, Rajaa Al; Ali, Mohamed M.; Alkerwi, Ala'a; Alvarez-Pedrerol, Mar; Aly, Eman; Amouyel, Philippe; Amuzu, Antoinette; Andersen, Lars Bo; Anderssen, Sigmund A.; Anjana, Ranjit Mohan; Aounallah-Skhiri, Hajer; Ariansen, Inger; Aris, Tahir; Arlappa, Nimmathota; Brewster, Lizzy M.; Hendriks, Marleen Elisabeth; Wit, Tobias F. Rinke de; Schultsz, Constance; Snijder, Marieke B.; Stronks, Karien; Valkengoed, Irene Gm van

    2016-01-01

    Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in

  19. Height estimations based on eye measurements throughout a gait cycle

    DEFF Research Database (Denmark)

    Yang, Sylvia X M; Larsen, Peter K; Alkjær, Tine

    2014-01-01

    (EH) measurement, on the other hand, is less prone to concealment. The purpose of the present study was to investigate: (1) how the eye height varies during the gait cycle, and (2) how the eye height changes with head position. The eyes were plotted manually in APAS for 16 test subjects during...

  20. Mixing height measurements from UHF wind profiling radar

    Energy Technology Data Exchange (ETDEWEB)

    Angevine, W.M.; Grimsdell, A.W. [CIRES, Univ. of Colorado, and NOAA Aeronomy Lab., Boulder, Colorado (United States)

    1997-10-01

    Mixing height in convective boundary layers can be detected by wind profiling radars (profilers) operating at or near 915 MHZ. We have made such measurements in a variety of settings including Alabama in 1992; Nova Scotia, Canada, during the North Atlantic Regional Experiment (NARE) 1993; Tennessee during the Southern Oxidant Study (SOS) 1994; near a 450 m tower in Wisconsin in 1995; and extensively in Illinois during the Flatland95, `96, and `97 experiments, as well as continuous operations at the Flatland Atmospheric Observatory. Profiler mixing height measurements, like all measurements, are subject to some limitations. The most important of these are due to rainfall, minimum height, and height resolution. Profilers are very sensitive to rain, which dominates the reflectivity and prevents the mixing height from being detected. Because the best height resolution is currently 60 m and the minimum height is 120-150 m AGL, the profiler is not suited for detecting mixing height in stable or nocturnal boundary layers. Problems may also arise in very dry or cold environments. (au) 12 refs.

  1. Accurate tool height control by bearing gap adjustment

    NARCIS (Netherlands)

    Wielen, van der A.M.; Schellekens, P.H.J.; Jaartsveld, F.T.M.

    2002-01-01

    Face turning of optical surfaces on precision lathes needs high precision tool height adjustment, which may be a difficult and time-consuming task. In this paper we present a new tool adjustment mechanism based on varying the bearing gap height of the hydrostatic bearings present in precision lathe

  2. Effects of wave-current interaction on storm surge in the Taiwan Strait: Insights from Typhoon Morakot

    Science.gov (United States)

    Yu, Xiaolong; Pan, Weiran; Zheng, Xiangjing; Zhou, Shenjie; Tao, Xiaoqin

    2017-08-01

    The effects of wave-current interaction on storm surge are investigated by a two-dimensional wave-current coupling model through simulations of Typhoon Morakot in the Taiwan Strait. The results show that wind wave and slope of sea floor govern wave setup modulations within the nearshore surf zone. Wave setup during Morakot can contribute up to 24% of the total storm surge with a maximum value of 0.28 m. The large wave setup commonly coincides with enhanced radiation stress gradient, which is itself associated with transfer of wave momentum flux. Water levels are to leading order in modulating significant wave height inside the estuary. High water levels due to tidal change and storm surge stabilize the wind wave and decay wave breaking. Outside of the estuary, waves are mainly affected by the current-induced modification of wind energy input to the wave generation. By comparing the observed significant wave height and water level with the results from uncoupled and coupled simulations, the latter shows a better agreement with the observations. It suggests that wave-current interaction plays an important role in determining the extreme storm surge and wave height in the study area and should not be neglected in a typhoon forecast.

  3. Extreme waves at Filyos, southern Black Sea

    Directory of Open Access Journals (Sweden)

    E. Bilyay

    2011-03-01

    Full Text Available A wave measurement project was carried out for a new port planned in Filyos, in the Western Black Sea region of Turkey. The measurement at a depth of 12.5 m lasted for a period of two years and 7949 records were obtained. During the analysis, it was noticed that there were 209 records in which H/Hs ratio was higher than 2.0. These higher waves in a record are called extreme waves in this study. Although the purpose of wave measurement is not to investigate extreme waves, it is believed that studying these unexpected waves could be interesting. Therefore, detailed statistical and spectral analyses on the extreme waves were done for the records. The analyses results show that the distribution of surface profiles of the records containing extreme waves deviates from Gaussian distribution with the negative skewness changing between –0.01 and –0.4 and with the high kurtosis in the range of 3.1–4.2. Although the probability of occurrence of the extreme waves is over-predicted by the Rayleigh distribution, a higher ratio of Hsrms indicates that the wave height distribution can be represented by Rayleigh. The average value of the slope of the frequency spectrum at the high frequency range is proportional to f–9 which is much steeper than the typical wind-wave frequency power law, f–4, –5. The directional spreading is measured with the parameter Smax and it is in the range of 5–70 for the extreme wave records. The wave and current interaction was also investigated and it was found that in most cases, extreme waves occur when the wave and the current are almost aligned. Furthermore, it is observed that extreme waves appear within a group of high waves.

  4. Definition of Physical Height Systems for Telluric Planets and Moons

    Science.gov (United States)

    Tenzer, Robert; Foroughi, Ismael; Sjöberg, Lars E.; Bagherbandi, Mohammad; Hirt, Christian; Pitoňák, Martin

    2018-01-01

    In planetary sciences, the geodetic (geometric) heights defined with respect to the reference surface (the sphere or the ellipsoid) or with respect to the center of the planet/moon are typically used for mapping topographic surface, compilation of global topographic models, detailed mapping of potential landing sites, and other space science and engineering purposes. Nevertheless, certain applications, such as studies of gravity-driven mass movements, require the physical heights to be defined with respect to the equipotential surface. Taking the analogy with terrestrial height systems, the realization of height systems for telluric planets and moons could be done by means of defining the orthometric and geoidal heights. In this case, however, the definition of the orthometric heights in principle differs. Whereas the terrestrial geoid is described as an equipotential surface that best approximates the mean sea level, such a definition for planets/moons is irrelevant in the absence of (liquid) global oceans. A more natural choice for planets and moons is to adopt the geoidal equipotential surface that closely approximates the geometric reference surface (the sphere or the ellipsoid). In this study, we address these aspects by proposing a more accurate approach for defining the orthometric heights for telluric planets and moons from available topographic and gravity models, while adopting the average crustal density in the absence of reliable crustal density models. In particular, we discuss a proper treatment of topographic masses in the context of gravimetric geoid determination. In numerical studies, we investigate differences between the geodetic and orthometric heights, represented by the geoidal heights, on Mercury, Venus, Mars, and Moon. Our results reveal that these differences are significant. The geoidal heights on Mercury vary from - 132 to 166 m. On Venus, the geoidal heights are between - 51 and 137 m with maxima on this planet at Atla Regio and Beta

  5. Laboratory Tests in the Development of WaveCat

    Directory of Open Access Journals (Sweden)

    James Allen

    2016-12-01

    Full Text Available WaveCat, a novel overtopping Wave Energy Converter, was tested with the aim of determining its performance under different sea states, establishing a starting point for optimisation of the device, numerical model validation and proof-of-concept for the control systems. The tests were carried out at a 1:30 scale in the Ocean Basin of the COAST Laboratory at University of Plymouth. A state-of-the-art control system was implemented, and overtopping rates and device motions were recorded alongside the wave field. It was observed that power generation is dependent on both the wave height and period, with smaller periods tending to produce greater overtopping rates, and therefore greater power generation, for the same wave height. Due to time constraints in the laboratory, only one configuration of draft/freeboard was tested; with this configuration, overtopping occurred under significant wave heights of 0.083 m or more, corresponding to 2.5 m or more in prototype values. These experimental results form the basis for future development and optimisation of WaveCat.

  6. Imaging height fluctuations in free-standing graphene membranes

    Science.gov (United States)

    Dorsey, Kyle; Miskin, Marc; Barnard, Arthur; Rose, Peter; Cohen, Itai; McEuen, Paul

    We present a technique based on multi-wavelength interference microscopy to measure the heights of observed ripples in free-standing graphene membranes. Graphene membranes released from a transparent substrate produce interference fringes when viewed in the reflection mode of an inverted microscope(Blees et. al. Nature 524 (7564): 204-207 (2015)). The fringes correspond to corrugation of the membrane as it floats near an interface. A single set of fringes is insufficient to uniquely determine the height profile, as a given fringe spacing can correspond to an increase or decrease in height by λ / 2 . Imaging at multiple wavelengths resolves the ambiguities in phase, and enables unique determination of the height profile of the membrane (Schilling et. al.Phys. Rev. E, 69:021901, 2004). We utilize this technique to map out the height fluctuations in free-standing graphene membranes to answer questions about fundamental mechanical properties of two-dimensional materials.

  7. Height, selected genetic markers and prostate cancer risk

    DEFF Research Database (Denmark)

    Lophatananon, Artitaya; Stewart-Brown, Sarah; Kote-Jarai, Zsofia

    2017-01-01

    Background:Evidence on height and prostate cancer risk is mixed, however, recent studies with large data sets support a possible role for its association with the risk of aggressive prostate cancer.Methods:We analysed data from the PRACTICAL consortium consisting of 6207 prostate cancer cases...... and 6016 controls and a subset of high grade cases (2480 cases). We explored height, polymorphisms in genes related to growth processes as main effects and their possible interactions.Results:The results suggest that height is associated with high-grade prostate cancer risk. Men with height >180 cm...... are at a 22% increased risk as compared to men with height prostate cancer risk. The aggregate scores of the selected variants identified a significantly increased risk of overall prostate cancer...

  8. Footprint parameters as a measure of arch height.

    Science.gov (United States)

    Hawes, M R; Nachbauer, W; Sovak, D; Nigg, B M

    1992-01-01

    The human foot has frequently been categorized into arch height groups based upon analysis of footprint parameters. This study investigates the relationship between directly measured arch height and many of the footprint parameters that have been assumed to represent arch height. A total of 115 male subjects were measured and footprint parameters were calculated from digitized outlines. Correlation and regression analyses were used to determine the relationship between footprint measures and arch height. It may be concluded from the results that footprint parameters proposed in the literature (arch angle, footprint index, and arch index) and two further parameters suggested in this study (arch length index and truncated arch index) are invalid as a basis for prediction or categorization of arch height. The categorization of the human foot according to the footprint measures evaluated in this paper represent no more than indices and angles of the plantar surface of the foot itself.

  9. Sensitivity of the urban airshed model to mixing height profiles

    Energy Technology Data Exchange (ETDEWEB)

    Rao, S.T.; Sistla, G.; Ku, J.Y.; Zhou, N.; Hao, W. [New York State Dept. of Environmental Conservation, Albany, NY (United States)

    1994-12-31

    The United States Environmental Protection Agency (USEPA) has recommended the use of the Urban Airshed Model (UAM), a grid-based photochemical model, for regulatory applications. One of the important parameters in applications of the UAM is the height of the mixed layer or the diffusion break. In this study, we examine the sensitivity of the UAM-predicted ozone concentrations to (a) a spatially invariant diurnal mixing height profile, and (b) a spatially varying diurnal mixing height profile for a high ozone episode of July 1988 for the New York Airshed. The 1985/88 emissions inventory used in the EPA`s Regional Oxidant Modeling simulations has been regridded for this study. Preliminary results suggest that the spatially varying case yields a higher peak ozone concentrations compared to the spatially invariant mixing height simulation, with differences in the peak ozone ranging from a few ppb to about 40 ppb for the days simulated. These differences are attributed to the differences in the shape of the mixing height profiles and its rate of growth during the morning hours when peak emissions are injected into the atmosphere. Examination of the impact of emissions reductions associated with these two mixing height profiles indicates that NO{sub x}-focussed controls provide a greater change in the predicted ozone peak under spatially invariant mixing heights than under the spatially varying mixing height profile. On the other hand, VOC-focussed controls provide a greater change in the predicted peak ozone levels under spatially varying mixing heights than under the spatially invariant mixing height profile.

  10. Evolution of Human Body Height and Its Implications in Ergonomics

    Directory of Open Access Journals (Sweden)

    İzzet DUYAR

    2009-06-01

    Full Text Available Body height is an crucial variable in the design and production of all physical spaces, primarily in the manifacturing of clothes and means of transportation. Having such an ergonomic significance, the height of the human being has constantly changed during the course of history. There exist strong data suggesting that this change is still continue. To find out stages of evolution of human height throughout the ages up to the present will help us to illuminate the human-environment relations, and to predict the possible changes that the human height might be subjected to in the future. In view of these reasons, the changes that has occured in human height from the period at which hominids appeared until humans’ transition into settled life have been closely examined. The study was carried out on the basis of the data obtained from the earlier studies in literature. These data, when considered as a whole, reveal that the human height did not continuously increase in a linear fashion in its evolutionary path but recorded some increases and decreases at different stages. The difference between males and females (sexual dimorphism has not shown a steady decrease either; instead, it has exhibited an oscillating pattern. The modern humans as a species is not unique in terms of their height; as a matter of fact, two million years ago hominids had existed at approximately the same height as the Homo sapiens. Although the average height had shown some decrease in Homo erectus, its distribution pattern was not much different than the one observed in the modern human societies. In the findings dated to the early stages of the Upper Paleolithic Age, height showed a tendency to increase again

  11. SRTM Data Release for Africa, Colored Height

    Science.gov (United States)

    2004-01-01

    Africa is dominated by the Great Rift Valley, extending from Lake Nyasa to the Red Sea, and splitting into two arms to enclose an interior plateau and the nearly circular Lake Victoria, visible in the right center of the image. To the west lies the Congo Basin, a vast, shallow depression which rises to form an almost circular rim of highlands. Most of the southern part of the continent rests on a concave plateau comprising the Kalahari basin and a mountainous fringe, skirted by a coastal plain which widens out in Mozambique in the southeast. Many of these regions were previously very poorly mapped due to persistent cloud cover or the inaccessibility of the terrain. Digital elevation data, such as provided by SRTM, are particularly in high demand by scientists studying earthquakes, volcanism, and erosion patterns for use in mapping and modeling hazards to human habitation. But the shape of Earth's surface affects nearly every natural process and human endeavor that occurs there, so elevation data are used in a wide range of applications. In this index map color-coding is directly related to topographic height, with brown and yellow at the lower elevations, rising through green, to white at the highest elevations. Blue areas on the map represent water within the mapped tiles, each of which includes shorelines or islands. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National

  12. ANALYTICAL SOLUTION FOR WAVES IN PLANETS WITH ATMOSPHERIC SUPERROTATION. I. ACOUSTIC AND INERTIA-GRAVITY WAVES

    Energy Technology Data Exchange (ETDEWEB)

    Peralta, J.; López-Valverde, M. A. [Instituto de Astrofísica de Andalucía (CSIC), Glorieta de la Astronomía, 18008 Granada (Spain); Imamura, T. [Institute of Space and Astronautical Science-Japan Aerospace Exploration Agency 3-1-1, Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Read, P. L. [Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford (United Kingdom); Luz, D. [Centro de Astronomia e Astrofísica da Universidade de Lisboa (CAAUL), Observatório Astronómico de Lisboa, Tapada da Ajuda, 1349-018 Lisboa (Portugal); Piccialli, A., E-mail: peralta@iaa.es [LATMOS, UVSQ, 11 bd dAlembert, 78280 Guyancourt (France)

    2014-07-01

    This paper is the first of a two-part study devoted to developing tools for a systematic classification of the wide variety of atmospheric waves expected on slowly rotating planets with atmospheric superrotation. Starting with the primitive equations for a cyclostrophic regime, we have deduced the analytical solution for the possible waves, simultaneously including the effect of the metric terms for the centrifugal force and the meridional shear of the background wind. In those cases when the conditions for the method of the multiple scales in height are met, these wave solutions are also valid when vertical shear of the background wind is present. A total of six types of waves have been found and their properties were characterized in terms of the corresponding dispersion relations and wave structures. In this first part, only waves that are direct solutions of the generic dispersion relation are studied—acoustic and inertia-gravity waves. Concerning inertia-gravity waves, we found that in the cases of short horizontal wavelengths, null background wind, or propagation in the equatorial region, only pure gravity waves are possible, while for the limit of large horizontal wavelengths and/or null static stability, the waves are inertial. The correspondence between classical atmospheric approximations and wave filtering has been examined too, and we carried out a classification of the mesoscale waves found in the clouds of Venus at different vertical levels of its atmosphere. Finally, the classification of waves in exoplanets is discussed and we provide a list of possible candidates with cyclostrophic regimes.

  13. [Influence of disc height on outcome of posterolateral fusion].

    Science.gov (United States)

    Drain, O; Lenoir, T; Dauzac, C; Rillardon, L; Guigui, P

    2008-09-01

    Experimentally, posterolateral fusion only provides incomplete control of flexion-extension, rotation and lateral inclination forces. The stability deficit increases with increasing height of the anterior intervertebral space, which for some warrants the adjunction of an intersomatic arthrodesis in addition to the posterolateral graft. Few studies have been devoted to the impact of disc height on the outcome of posterolateral fusion. The purpose of this work was to investigate the spinal segment immobilized by the posterolateral fusion: height of the anterior intervertebral space, the clinical and radiographic impact of changes in disc height, and the short- and long-term impact of disc height measured preoperatively on clinical and radiographic outcome. In order to obtain a homogeneous group of patients, the series was limited to patients undergoing posterolateral arthrodesis for degenerative spondylolisthesis, in combination with radicular release. This was a retrospective analysis of a consecutive series of 66 patients with mean 52 months follow-up (range 3-63 months). A dedicated self-administered questionnaire was used to collect data on pre- and postoperative function, the SF-36 quality of life score, and patient satisfaction. Pre- and postoperative (early, one year, last follow-up) radiographic data were recorded: olisthesic level, disc height, intervertebral angle, intervertebral mobility (angular, anteroposterior), and global measures of sagittal balance (thoracic kyphosis, lumbar lordosis, T9 sagittal tilt, pelvic version, pelvic incidence, sacral slope). SpineView was used for all measures. Univariate analysis searched for correlations between variation in disc height and early postoperative function and quality of fusion at last follow-up. Multivariate analysis was applied to the following preoperative parameters: intervertebral angle, disc height, intervertebral mobility, sagittal balance parameters, use of osteosynthesis or not. At the olisthesic

  14. Transformation of Waves Across the Surf Zone.

    Science.gov (United States)

    1981-03-01

    Kuo is more realis- tic but still results in a sharp cut-off of the distribution at the breaking heights. 5. Goda Distribution Goda (1975) derived a...J.I., "Probabilities of Breaking Wave Characteris- tics ," Proc. 12th Coastal Engineering Conf., pp. 399- 412, 1970. Chakrabarty, S.K. and R.P. Cooley...Spring, MD 20910 21. Director 2 Instituto Oceanografico de la Armada Guayaquil, Ecuador 22. Director de Educacion de la Armada Comandancia General de

  15. An analysis of the relationship between bodily injury severity and fall height in victims of fatal falls from height

    Directory of Open Access Journals (Sweden)

    Grzegorz Teresiński

    2017-03-01

    Full Text Available Aim of the study : One of the basic issues discussed in forensic literature regarding falls from a height is determination of fall heights and differentiation between suicidal and accidental falls. The aim of the study was to verify the usefulness of the available methods for the purposes of forensic expertises. Material and methods : The study encompassed fatalities of falls from a height whose autopsies were performed in the Department of Forensic Medicine in Lublin. Results : Similarly to other authors, the severity of injuries was assessed using the Abbreviated Injury Scale (AIS and injury severity score (ISS. The study findings demonstrated a statistically significant correlation between the fall height and the severity of injuries according to ISS and a statistically significant difference in fall heights between the groups of accidents and suicides.

  16. Brain structure mediates the association between height and cognitive ability.

    Science.gov (United States)

    Vuoksimaa, Eero; Panizzon, Matthew S; Franz, Carol E; Fennema-Notestine, Christine; Hagler, Donald J; Lyons, Michael J; Dale, Anders M; Kremen, William S

    2018-05-11

    Height and general cognitive ability are positively associated, but the underlying mechanisms of this relationship are not well understood. Both height and general cognitive ability are positively associated with brain size. Still, the neural substrate of the height-cognitive ability association is unclear. We used a sample of 515 middle-aged male twins with structural magnetic resonance imaging data to investigate whether the association between height and cognitive ability is mediated by cortical size. In addition to cortical volume, we used genetically, ontogenetically and phylogenetically distinct cortical metrics of total cortical surface area and mean cortical thickness. Height was positively associated with general cognitive ability and total cortical volume and cortical surface area, but not with mean cortical thickness. Mediation models indicated that the well-replicated height-general cognitive ability association is accounted for by individual differences in total cortical volume and cortical surface area (highly heritable metrics related to global brain size), and that the genetic association between cortical surface area and general cognitive ability underlies the phenotypic height-general cognitive ability relationship.

  17. Multipeakedness and groupiness of shallow water waves along Indian coast

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; Anand, N.M.; AshokKumar, K.; Mandal, S.

    IM-.. .. . ..................................-;.. +++ -+t+++t+Mi-##+ ' .. ++~-* ..... + +t........ .. + .. .... .......... + ............................. _ ...·_-.a._IMIIIII....... I".".I .............Ht1t-+ .. l j ! I 0.0 l l I 1 l I i 0.0 0.1 0.2 0.3 5.0 0.0 6.0 I 0.2 0.4 0.6 0.8 1.0 5.0 5.0 5...- quencies fpl and fp2' The sequential correlation bet.ween suc cessive wave heights, r HH (RYE, 1974), between successive wave periods, r 1T and between wave height and wave period: r HT (GaDA, 1978) were evaluated as given below. Also the spec tral...

  18. Can infundibular height predict the clearance of lower pole calyceal stone after extracorporeal shockwave lithotripsy?

    Directory of Open Access Journals (Sweden)

    M. Arzoz-Fabregas

    2009-04-01

    Full Text Available PURPOSE: To evaluate the efficacy of extracorporeal shock wave lithotripsy (SWL on lower calyceal calculi in relation to the renal anatomical factors and determine which of these factors can be used to select patients who will benefit from SWL. MATERIAL AND METHODS: We analyzed retrospectively 78 patients with single radiopaque lower calyceal stones treated with SWL. The patients were evaluated 3 months after lithotripsy with a simple abdominal X-ray and a kidney ultrasound scan. The success of the treatment, removal of all fragments, was correlated with renal anatomical factors measured in the pre-treatment intravenous urography: infundibulopelvic angle, lower infundibulum width, lower infundibulum length, ratio length/width, infundibulum height, and number of minor calyces in the lower calyceal group. RESULTS: Three months after SWL treatment, 39 patients were stone-free (NR group and 39 had residual fragments (R group. Both groups presented no differences in relation to infundibulopelvic angle, width and length of the lower calyceal infundibulum, length/width ratio of the lower infundibulum or number of lower calyces. Height of the infundibulum, described as the distance between the line passing through the lowest part of the calyx containing the calculus and the highest point of the lower lip of renal pelvis, was the only parameter in which significant differences (p = 0.002 were found between the NR and R groups. CONCLUSIONS: Lower Infundibular height could be a good measurement tool for deciding which patients with lower calyceal lithiasis would benefit from SWL treatment. Height of less than 22 mm suggests a good outcome from lithotripsy.

  19. Numerical study on design for wave energy generation of a floater for energy absorption

    International Nuclear Information System (INIS)

    Li, Kui Ming; Parthasarathy, Nanjundan; Choi, Yoon Hwan; Lee, Yeon Won

    2012-01-01

    In order to design a wave energy generating system of a floater type, a 6 DOF motion technique was applied to the three Dimensional CFD analysis on a floating body and the behavior was interpreted according to the nature of the incoming waves. Waves in a tank model were generated using a single floater comparing with that of a Pelamis wave energy converter. In this paper, we focus on four variables, namely the wave height, angular velocity, diameter and length of the floater. The process was carried out in three stages and it was found that there are energy absorption differences in different parameters of wave height, length and the diameter of a floater during simulation, thus leading for the necessity of an optimal design for wave energy generation

  20. The association between adult attained height and sitting height with mortality in the European prospective investigation into cancer and nutrition (EPIC)

    NARCIS (Netherlands)

    Sawada, Norie; Wark, Petra A.; Merritt, Melissa A.; Tsugane, Shoichiro; Ward, Heather A.; Rinaldi, Sabina; Weiderpass, Elisabete; Dartois, Laureen; His, Mathilde; Boutron-Ruault, Marie Christine; Turzanski-Fortner, Renée; Kaaks, Rudolf; Overvad, Kim; Redondo, María Luisa; Travier, Noemie; Molina-Portillo, Elena; Dorronsoro, Miren; Cirera, Lluis; Ardanaz, Eva; Perez-Cornago, Aurora; Trichopoulou, Antonia; Lagiou, Pagona; Valanou, Elissavet; Masala, Giovanna; Pala, Valeria; Peeters, Petra H M; Van Der Schouw, Yvonne T.; Melander, Olle; Manjer, Jonas; Silva, Marisa Da; Skeie, Guri; Tjønneland, Anne; Olsen, Anja; Gunter, Marc J.; Riboli, Elio; Cross, Amanda J.

    2017-01-01

    Adult height and sitting height may reflect genetic and environmental factors, including early life nutrition, physical and social environments. Previous studies have reported divergent associations for height and chronic disease mortality, with positive associations observed for cancer mortality

  1. Global Distribution of Planetary Boundary Layer Height Derived from CALIPSO

    Science.gov (United States)

    Huang, J.

    2015-12-01

    The global distribution of planetary boundary layer (PBL) height, which was estimated from the attenuated back-scatter observations of Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), is presented. In general, the PBL is capped by a temperature inversion that tends to trap moisture and aerosols. The gradient of back-scatter observed by lidar is almost always associated with this temperature inversion and the simultaneous decrease of moisture content. Thus, the PBL top is defined as the location of the maximum aerosol scattering gradient, which is analogous to the more conventional thermodynamic definition. The maximum standard deviation method, developed by Jordan et al. (2010), is modified and used to derive the global PBL heights. The derived PBL heights are not only consistent with the results of McGrath-Spangler and Denning (2012) but also agree well with the ground-based lidar measurements. It is found that the correlation between CALIPSO and the ground-based lidar was 0.73. The seasonal mean patterns from 4-year mid-day PBL heights over global are demonstrated. Also it is found that the largest PBL heights occur over the Tibetan Plateau and the coastal areas. The smallest PBL heights appear in the Tarim Basin and the northeast of China during the local winter. The comparison of PBL heights from CALIPSO and ECMWF under different land-cover conditions showed that, over ocean and forest surface, the PBL height estimated from the CALIPSO back-scatter climatology is larger than the ones estimated from ECMWF data. However, the PBL heights from ECMWF, over grass land and bare land surface in spring and summer are larger than the ones from CALIPSO.

  2. Multiscale climate emulator of multimodal wave spectra: MUSCLE-spectra

    Science.gov (United States)

    Rueda, Ana; Hegermiller, Christie A.; Antolinez, Jose A. A.; Camus, Paula; Vitousek, Sean; Ruggiero, Peter; Barnard, Patrick L.; Erikson, Li H.; Tomás, Antonio; Mendez, Fernando J.

    2017-02-01

    Characterization of multimodal directional wave spectra is important for many offshore and coastal applications, such as marine forecasting, coastal hazard assessment, and design of offshore wave energy farms and coastal structures. However, the multivariate and multiscale nature of wave climate variability makes this complex problem tractable using computationally expensive numerical models. So far, the skill of statistical-downscaling model-based parametric (unimodal) wave conditions is limited in large ocean basins such as the Pacific. The recent availability of long-term directional spectral data from buoys and wave hindcast models allows for development of stochastic models that include multimodal sea-state parameters. This work introduces a statistical downscaling framework based on weather types to predict multimodal wave spectra (e.g., significant wave height, mean wave period, and mean wave direction from different storm systems, including sea and swells) from large-scale atmospheric pressure fields. For each weather type, variables of interest are modeled using the categorical distribution for the sea-state type, the Generalized Extreme Value (GEV) distribution for wave height and wave period, a multivariate Gaussian copula for the interdependence between variables, and a Markov chain model for the chronology of daily weather types. We apply the model to the southern California coast, where local seas and swells from both the Northern and Southern Hemispheres contribute to the multimodal wave spectrum. This work allows attribution of particular extreme multimodal wave events to specific atmospheric conditions, expanding knowledge of time-dependent, climate-driven offshore and coastal sea-state conditions that have a significant influence on local nearshore processes, coastal morphology, and flood hazards.

  3. Multiconfiguration pair-density functional theory: barrier heights and main group and transition metal energetics.

    Science.gov (United States)

    Carlson, Rebecca K; Li Manni, Giovanni; Sonnenberger, Andrew L; Truhlar, Donald G; Gagliardi, Laura

    2015-01-13

    Kohn-Sham density functional theory, resting on the representation of the electronic density and kinetic energy by a single Slater determinant, has revolutionized chemistry, but for open-shell systems, the Kohn-Sham Slater determinant has the wrong symmetry properties as compared to an accurate wave function. We have recently proposed a theory, called multiconfiguration pair-density functional theory (MC-PDFT), in which the electronic kinetic energy and classical Coulomb energy are calculated from a multiconfiguration wave function with the correct symmetry properties, and the rest of the energy is calculated from a density functional, called the on-top density functional, that depends on the density and the on-top pair density calculated from this wave function. We also proposed a simple way to approximate the on-top density functional by translation of Kohn-Sham exchange-correlation functionals. The method is much less expensive than other post-SCF methods for calculating the dynamical correlation energy starting with a multiconfiguration self-consistent-field wave function as the reference wave function, and initial tests of the theory were quite encouraging. Here, we provide a broader test of the theory by applying it to bond energies of main-group molecules and transition metal complexes, barrier heights and reaction energies for diverse chemical reactions, proton affinities, and the water dimerization energy. Averaged over 56 data points, the mean unsigned error is 3.2 kcal/mol for MC-PDFT, as compared to 6.9 kcal/mol for Kohn-Sham theory with a comparable density functional. MC-PDFT is more accurate on average than complete active space second-order perturbation theory (CASPT2) for main-group small-molecule bond energies, alkyl bond dissociation energies, transition-metal-ligand bond energies, proton affinities, and the water dimerization energy.

  4. On the pressure field of nonlinear standing water waves

    Science.gov (United States)

    Schwartz, L. W.

    1980-01-01

    The pressure field produced by two dimensional nonlinear time and space periodic standing waves was calculated as a series expansion in the wave height. The high order series was summed by the use of Pade approximants. Calculations included the pressure variation at great depth, which was considered to be a likely cause of microseismic activity, and the pressure distribution on a vertical barrier or breakwater.

  5. Efficient Wave Energy Amplification with Wave Reflectors

    DEFF Research Database (Denmark)

    Kramer, Morten Mejlhede; Frigaard, Peter Bak

    2002-01-01

    Wave Energy Converters (WEC's) extract wave energy from a limited area, often a single point or line even though the wave energy is generally spread out along the wave crest. By the use of wave reflectors (reflecting walls) the wave energy is effectively focused and increased to approximately 130......-140%. In the paper a procedure for calculating the efficiency and optimizing the geometry of wave reflectors are described, this by use of a 3D boundary element method. The calculations are verified by laboratory experiments and a very good agreement is found. The paper gives estimates of possible power benifit...... for different geometries of the wave reflectors and optimal geometrical design parameters are specified. On this basis inventors of WEC's can evaluate whether a specific WEC possible could benefit from wave reflectors....

  6. Characteristics of inertial currents observed in offshore wave records

    Science.gov (United States)

    Gemmrich, J.; Garrett, C.

    2012-04-01

    It is well known that ambient currents can change the amplitude, direction and frequency of ocean surface waves. Regions with persistent strong currents, such as the Agulhas current off the east coast of South Africa, are known as areas of extreme waves, and wave height modulations of up to 50% observed in the shallow North Sea have been linked to tidal currents. In the open ocean, inertial currents, while intermittent, are typically the most energetic currents with speeds up to 0.5 m/s, and can interact with the surface wave field to create wave modulation, though this has not previously been reported. We use long records of significant wave heights from buoy observations in the northeast Pacific and show evidence of significant modulation at frequencies that are slightly higher than the local inertial frequency. Quite apart from the relevance to surface waves, this result can provide a consistent and independent measurement, over a wide range of latitudes, of the frequency blue-shift, the strength and intermittency of ocean surface inertial currents. Near-inertial waves constitute the most energetic portion of the internal wave band and play a significant role in deep ocean mixing. So far, observational data on near-surface inertial currents has tended to come from short records that do not permit the reliable determination of the frequency blue-shift, though this is an important factor affecting the energy flux from the surface into deeper waters. Long records from routine wave height observations are widely available and could help to shed new light globally on the blue-shift and on the characteristics of inertial currents.

  7. Wave energy converter effects on wave propagation: A sensitivity study in Monterey Bay, CA

    Science.gov (United States)

    Chang, G.; Jones, C. A.; Roberts, J.; Magalen, J.; Ruehl, K.; Chartrand, C.

    2014-12-01

    The development of renewable offshore energy in the United States is growing rapidly and wave energy is one of the largest resources currently being evaluated. The deployment of wave energy converter (WEC) arrays required to harness this resource could feasibly number in the hundreds of individual devices. The WEC arrays have the potential to alter nearshore wave propagation and circulation patterns and ecosystem processes. As the industry progresses from pilot- to commercial-scale it is important to understand and quantify the effects of WECs on the natural nearshore processes that support a local, healthy ecosystem. To help accelerate the realization of commercial-scale wave power, predictive modeling tools have been developed and utilized to evaluate the likelihood of environmental impact. At present, direct measurements of the effects of different types of WEC arrays on nearshore wave propagation are not available; therefore wave model simulations provide the groundwork for investigations of the sensitivity of model results to prescribed WEC characteristics over a range of anticipated wave conditions. The present study incorporates a modified version of an industry standard wave modeling tool, SWAN (Simulating WAves Nearshore), to simulate wave propagation through a hypothetical WEC array deployment site on the California coast. The modified SWAN, referred to as SNL-SWAN, incorporates device-specific WEC power take-off characteristics to more accurately evaluate a WEC device's effects on wave propagation. The primary objectives were to investigate the effects of a range of WEC devices and device and array characteristics (e.g., device spacing, number of WECs in an array) on nearshore wave propagation using SNL-SWAN model simulations. Results showed that significant wave height was most sensitive to variations in WEC device type and size and the number of WEC devices in an array. Locations in the lee centerline of the arrays in each modeled scenario showed the

  8. European Space Science Scales New Heights

    Science.gov (United States)

    1995-06-01

    been approved by all ESA's Member States. Outside Europe, the stability and solidity of Horizon 2000 have made ESA an extremely credible and reliable partner, arousing ever greater interest in international - including transatlantic - co-operation. Given that the first results look positive, it makes sense to think about continuing the work done to date. Which is why this year, half-way through Horizon 2000, it is time to look ahead to the next twenty-year period and embark on the follow-up programme which will lead to further missions being carried out between 2006 and 2016. At ESA Council meeting to be held in October in Toulouse, European ministers responsible for space will therefore have to take a decision on a "Horizon 2000 PLUS " programme designed to ensure successful European space science over a further ten-year period. The proposal being put forward by ESA's directorate of scientific programmes involves setting up three large-scale missions: * a mission to explore Mercury, the least known of the inner solar planets, 60iln of whose surface has yet to be mapped * an interferometry observatory designed to map the sky a hundred times more accurately than the Hipparcos satellite * a gravitational observatory able to pick up the space time waves emitted by the universe at the precise moment of the Big Bang. In parallel four medium-size missions - their content still to be defined - would be carried out. As with its forerunner, Horizon 2000 PLUS has been defined on the basis of proposals submitted by the scientific community following open competition. In all, I10 mission concepts were proposed by a total of 2500 scientists. These were then examined by peer-review groups, involving 75 scientists in all who announced their final choice on I October 1994. The agency is proposing to start preparing for Horizon 2000 PLUS on the basis of level funding up to the year 2000. This means that ESA would undertake to conduct preliminary Horizon 2000 PLUS technological studies

  9. Buoy and Generator Interaction with Ocean Waves: Studies of a Wave Energy Conversion System

    Energy Technology Data Exchange (ETDEWEB)

    Lindroth, Simon

    2011-07-01

    On March 13th, 2006, the Div. of Electricity at Uppsala Univ. deployed its first wave energy converter, L1, in the ocean southwest of Lysekil. L1 consisted of a buoy at the surface, connected through a line to a linear generator on the seabed. Since the deployment, continuous investigations of how L1 works in the waves have been conducted, and several additional wave energy converters have been deployed. This thesis is based on ten publications, which focus on different aspects of the interaction between wave, buoy, and generator. In order to evaluate different measurement systems, the motion of the buoy was measured optically and using accelerometers, and compared to measurements of the motion of the movable part of the generator - the translator. These measurements were found to correlate well. Simulations of buoy and translator motion were found to match the measured values. The variation of performance of L1 with changing water levels, wave heights, and spectral shapes was also investigated. Performance is here defined as the ratio of absorbed power to incoming power. It was found that the performance decreases for large wave heights. This is in accordance with the theoretical predictions, since the area for which the stator and the translator overlap decreases for large translator motions. Shifting water levels were predicted to have the same effect, but this could not be seen as clearly. The width of the wave energy spectrum has been proposed by some as a factor that also affects the performance of a wave energy converter, for a set wave height and period. Therefore the relation between performance and several different parameters for spectral width was investigated. It was found that some of the parameters were in fact correlated to performance, but that the correlation was not very strong. As a background on ocean measurements in wave energy, a thorough literature review was conducted. It turns out that the Lysekil project is one of quite few projects that

  10. Waves and Tsunami Project

    Science.gov (United States)

    Frashure, K. M.; Chen, R. F.; Stephen, R. A.; Bolmer, T.; Lavin, M.; Strohschneider, D.; Maichle, R.; Micozzi, N.; Cramer, C.

    2007-01-01

    Demonstrating wave processes quantitatively in the classroom using standard classroom tools (such as Slinkys and wave tanks) can be difficult. For example, waves often travel too fast for students to actually measure amplitude or wavelength. Also, when teaching propagating waves, reflections from the ends set up standing waves, which can confuse…

  11. Evaluation of the Correlation of Ramus Height, Gonial Angle, and ...

    African Journals Online (AJOL)

    molar infraocclusion, ramus height, and vertical face type.[1]. Deep bite has been found to ... different facial forms. Subjects and Methods: A total of 51 subjects in all facial form ... to improve the effectiveness of any prosthesis and maintain the.

  12. MLS/Aura L2 Geopotential Height V003

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2GPH is the EOS Aura Microwave Limb Sounder (MLS) standard product for geopotential height derived from radiances measured by the 118 and 240 GHz radiometers. The...

  13. MLS/Aura L2 Geopotential Height V002

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2GPH is the EOS Aura Microwave Limb Sounder (MLS) standard product for geopotential height derived from radiances measured by the 118 and 240 GHz radiometers. The...

  14. OW AVISO Sea-Surface Height & Niiler Climatology

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The dataset contains satellite-derived sea-surface height measurements collected by means of the TOPEX/Poseidon/ERS, JASON-1/Envisat, and Jason-2/Envisat satellite...

  15. Childhood height increases the risk of prostate cancer mortality

    DEFF Research Database (Denmark)

    Aarestrup, J; Gamborg, M; Cook, M B

    2015-01-01

    cancers. Cox proportional hazards regressions were performed. RESULTS: 630 men had prostate cancer recorded as the underlying cause of death. Childhood height at age 13years was positively associated with prostate cancer-specific mortality (hazard ratio [HR]per z-score=1.2, 95% confidence interval [CI]: 1.1-1.3......). Associations were significant at all other childhood ages. Growth analyses showed that height at age 13years had a stronger association with prostate cancer-specific mortality than height at age 7, suggesting the association at age 7 is largely mediated through later childhood height. The tallest boys at age...... 13years had a significantly worse survival, but only when restricted to a diagnosis at years of age (HRz-score of 1=1.7, 95% CI: 1.3-2.4). These associations were significant at all other childhood ages. Childhood BMI was not associated with prostate cancer mortality or survival. CONCLUSION...

  16. A century of trends in adult human height

    DEFF Research Database (Denmark)

    Damsgaard, Camilla Trab; Michaelsen, Kim F.; Molbo, Drude

    2016-01-01

    in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5-22.7) and 16.5 cm (13.3-19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over...... the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8-144.8). The height differential between the tallest...... and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries....

  17. A Mathematical Model for the Height of a Satellite.

    Science.gov (United States)

    Thoemke, Sharon S.; And Others

    1993-01-01

    Emphasizes a real-world-problem situation using sine law and cosine law. Angles of elevation from two tracking stations located in the plane of the equator determine height of a satellite. Calculators or computers can be used. (LDR)

  18. Height, zinc and soil-transmitted helminth infections in schoolchildren

    DEFF Research Database (Denmark)

    de Gier, Brechje; Mpabanzi, Liliane; Vereecken, Kim

    2015-01-01

    Soil-transmitted helminth (STH) infections and zinc deficiency are often found in low- and middle-income countries and are both known to affect child growth. However, studies combining data on zinc and STH are lacking. In two studies in schoolchildren in Cuba and Cambodia, we collected data...... on height, STH infection and zinc concentration in either plasma (Cambodia) or hair (Cuba). We analyzed whether STH and/or zinc were associated with height for age z-scores and whether STH and zinc were associated. In Cuba, STH prevalence was 8.4%; these were mainly Ascaris lumbricoides and Trichuris...... trichiura infections. In Cambodia, STH prevalence was 16.8%, mostly caused by hookworm. In Cuban children, STH infection had a strong association with height for age (aB-0.438, p = 0.001), while hair zinc was significantly associated with height for age only in STH uninfected children. In Cambodian children...

  19. U.S. Geoid Heights, Scientific Model (G96SSS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' geoid height grid for the conterminous United States is the G96SSS model. The computation used about 1.8 million terrestrial and marine gravity data held in...

  20. Modeling wave attenuation by salt marshes in Jamaica Bay, New York, using a new rapid wave model

    Science.gov (United States)

    Marsooli, Reza; Orton, Philip M.; Mellor, George

    2017-07-01

    Using a new rapid-computation wave model, improved and validated in the present study, we quantify the value of salt marshes in Jamaica Bay—a highly urbanized estuary located in New York City—as natural buffers against storm waves. We augment the MDO phase-averaged wave model by incorporating a vegetation-drag-induced energy dissipation term into its wave energy balance equation. We adopt an empirical formula from literature to determine the vegetation drag coefficient as a function of environmental conditions. Model evaluation using data from laboratory-scale experiments show that the improved MDO model accurately captures wave height attenuation due to submerged and emergent vegetation. We apply the validated model to Jamaica Bay to quantify the influence of coastal-scale salt marshes on storm waves. It is found that the impact of marsh islands is largest for storms with lower flood levels, due to wave breaking on the marsh island substrate. However, the role of the actual marsh plants, Spartina alterniflora, grows larger for storms with higher flood levels, when wave breaking does not occur and the vegetative drag becomes the main source of energy dissipation. For the latter case, seasonality of marsh height is important; at its maximum height in early fall, S. alterniflora causes twice the reduction as when it is at a shorter height in early summer. The model results also indicate that the vegetation drag coefficient varies 1 order of magnitude in the study area, and suggest exercising extra caution in using a constant drag coefficient in coastal wetlands.

  1. Generation of intermittent gravitocapillary waves via parametric forcing

    Science.gov (United States)

    Castillo, Gustavo; Falcón, Claudio

    2018-04-01

    We report on the generation of an intermittent wave field driven by a horizontally moving wave maker interacting with Faraday waves. The spectrum of the local gravitocapillary surface wave fluctuations displays a power law in frequency for a wide range of forcing parameters. We compute the probability density function of the local surface height increments, which show that they change strongly across time scales. The structure functions of these increments are shown to display power laws as a function of the time lag, with exponents that are nonlinear functions of the order of the structure function. We argue that the origin of this scale-invariant intermittent spectrum is the Faraday wave pattern breakup due to its advection by the propagating gravity waves. Finally, some interpretations are proposed to explain the appearance of this intermittent spectrum.

  2. Transient wave behaviour over an underwater sliding hump from experiments and analytical and numerical modelling

    Energy Technology Data Exchange (ETDEWEB)

    Callaghan, David P.; Nielsen, Peter [The University of Queensland, School of Civil Engineering, Brisbane (Australia); Ahmadi, Afshin [Kellogg Brown and Root Pty Ltd, Brisbane, QLD (Australia)

    2011-12-15

    Flume measurements of a one-dimensional sliding hump starting from rest in quiescence fresh water indicate that when the hump travels at speed less than the shallow-water wave celerity, three waves emerge, travelling in two directions. One wave travels in the opposite direction to the sliding hump at approximately the shallow-water wave celerity (backward free wave). Another wave travels approximately in step with the hump (forced wave), and the remaining wave travels in the direction of the hump at approximately the shallow-water wave celerity (forward free wave). These experiments were completed for a range of sliding hump speed relative to the shallow-water wave celerity, up to unity of this ratio, to investigate possible derivation from solutions of the Euler equation with non-linear and non-hydrostatic terms being included or excluded. For the experimental arrangements tested, the forced waves were negative (depression or reduced water surface elevation) waves while the free waves were positive (bulges or increased water surface elevation). For experiments where the sliding hump travelled at less than 80% of the shallow-water wave celerity did not include transient behaviour measurements (i.e. when the three waves still overlapped). The three wave framework was partially supported by these measurements in that the separated forward and forced waves were compared to measurements. For the laboratory scale experiments, the forward free wave height was predicted reasonably by the long-wave equation (ignoring non-linear and non-hydrostatic terms) when the sliding hump speed was less than 80% of the shallow-water wave celerity. The forced wave depression magnitude required the Euler equations for all hump speed tested. The long-wave solution, while being valid in a limited parameter range, does predict the existence of the three waves as found in these experiments (forward travelling waves measured quantitatively while the backward travelling waves visually by video

  3. Definition of Physical Height Systems for Telluric Planets and Moons

    OpenAIRE

    Tenzer, R.; Foroughi, I.; Sjöberg, L.E.; Bagherbandi, M.; Hirt, C.; Pitoňák, M.

    2018-01-01

    In planetary sciences, the geodetic (geometric) heights defined with respect to the reference surface (the sphere or the ellipsoid) or with respect to the center of the planet/moon are typically used for mapping topographic surface, compilation of global topographic models, detailed mapping of potential landing sites, and other space science and engineering purposes. Nevertheless, certain applications, such as studies of gravity-driven mass movements, require the physical heights to be define...

  4. Stature estimation using the knee height measurement amongst Brazilian elderly

    OpenAIRE

    Siqueira Fogal, Aline; Franceschini, Sylvia do Carmo Castro; Eloiza Priore, Silvia; Cotta, Rosângela Minardi M.; Queiroz Ribeiro, Andreia

    2015-01-01

    Introduction: Stature is an important variable in several indices of nutritional status that are applicable to elderly persons. However, stature is difficult or impossible to measure in elderly because they are often unable to maintain the standing position. A alternative is the use of estimated height from measurements of knee height measure. Aims: This study aimed to evaluate the accuracy of the formula proposed by Chumlea et al. (1985) based on the knee of a Caucasian population to estimat...

  5. Effect of cutting height and frequency on Leucaena leucocephala ...

    African Journals Online (AJOL)

    Leucaena leucocephala is a fast-growing tree that can provide both high quality forage and firewood. The objective of this trial was to determine the optimum height and frequency of cutting for both wood and forage production. Cutting heights at 0.3m, 0.6m and 1.0 m were superimposed on 3-month and 6-month cutting ...

  6. Experimental and Numerical Studies on Wave Breaking Characteristics over a Fringing Reef under Monochromatic Wave Conditions

    Directory of Open Access Journals (Sweden)

    Jong-In Lee

    2014-01-01

    Full Text Available Fringing reefs play an important role in protecting the coastal area by inducing wave breaking and wave energy dissipation. However, modeling of wave transformation and energy dissipation on this topography is still difficult due to the unique structure. In the present study, two-dimensional laboratory experiments were conducted to investigate the cross-shore variations of wave transformation, setup, and breaking phenomena over an idealized fringing reef with the 1/40 reef slope and to verify the Boussinesq model under monochromatic wave conditions. One-layer and two-layer model configurations of the Boussinesq model were used to figure out the model capability. Both models predicted well (r2>0.8 the cross-shore variation of the wave heights, crests, troughs, and setups when the nonlinearity is not too high (A0/h0<0.07 in this study. However, as the wave nonlinearity and steepness increase, the one-layer model showed problems in prediction and stability due to the error on the vertical profile of fluid velocity. The results in this study revealed that one-layer model is not suitable in the highly nonlinear wave condition over a fringing reef bathymetry. This data set can contribute to the numerical model verification.

  7. Variability of the Mixed-Layer Height Over Mexico City

    Science.gov (United States)

    García-Franco, J. L.; Stremme, W.; Bezanilla, A.; Ruiz-Angulo, A.; Grutter, M.

    2018-06-01

    The diurnal and seasonal variability of the mixed-layer height in urban areas has implications for ground-level air pollution and the meteorological conditions. Measurements of the backscatter of light pulses with a commercial lidar system were performed for a continuous period of almost six years between 2011 and 2016 in the southern part of Mexico City. The profiles were temporally and vertically smoothed, clouds were filtered out, and the mixed-layer height was determined with an ad hoc treatment of both the filtered and unfiltered profiles. The results are in agreement when compared with values of mixed-layer height reconstructed from, (i) radiosonde data, and (ii) surface and vertical column densities of a trace gas. The daily maxima of the mean mixed-layer height reach values > 3 km above ground level in the months of March-April, and are clearly lower (behaviour, which is characterized together with the mixed-layer-height anomalies. A clear residual layer is evident from the backscattered signals recorded in days with specific atmospheric conditions, but also from the cloud-filtered mean diurnal profiles. The occasional presence of a residual layer results in an overestimation of the reported mixed-layer height during the night and early morning hours.

  8. Modelling foot height and foot shape-related dimensions.

    Science.gov (United States)

    Xiong, Shuping; Goonetilleke, Ravindra S; Witana, Channa P; Lee Au, Emily Yim

    2008-08-01

    The application of foot anthropometry to design good-fitting footwear has been difficult due to the lack of generalised models. This study seeks to model foot dimensions so that the characteristic shapes of feet, especially in the midfoot region, can be understood. Fifty Hong Kong Chinese adults (26 males and 24 females) participated in this study. Their foot lengths, foot widths, ball girths and foot heights were measured and then evaluated using mathematical models. The results showed that there were no significant allometry (p > 0.05) effects of foot length on ball girth and foot width. Foot height showed no direct relationship with foot length. However, a normalisation with respect to foot length and foot height resulted in a significant relationship for both males and females with R(2) greater than 0.97. Due to the lack of a direct relationship between foot height and foot length, the current practice of grading shoes with a constant increase in height or proportionate scaling in response to foot length is less than ideal. The results when validated with other populations can be a significant way forward in the design of footwear that has an improved fit in the height dimension.

  9. Weighting of field heights for sharpness and noisiness

    Science.gov (United States)

    Keelan, Brian W.; Jin, Elaine W.

    2009-01-01

    Weighting of field heights is important in cases when a single numerical value needs to be calculated that characterizes an attribute's overall impact on perceived image quality. In this paper we report an observer study to derive the weighting of field heights for sharpness and noisiness. One-hundred-forty images were selected to represent a typical consumer photo space distribution. Fifty-three sample points were sampled per image, representing field heights of 0, 14, 32, 42, 51, 58, 71, 76, 86% and 100%. Six observers participated in this study. The field weights derived in this report include both: the effect of area versus field height (which is a purely objective, geometric factor); and the effect of the spatial distribution of image content that draws attention to or masks each of these image structure attributes. The results show that relative to the geometrical area weights, sharpness weights were skewed to lower field heights, because sharpness-critical subject matter was often positioned relatively near the center of an image. Conversely, because noise can be masked by signal, noisiness-critical content (such as blue skies, skin tones, walls, etc.) tended to occur farther from the center of an image, causing the weights to be skewed to higher field heights.

  10. Maternal and Paternal Height and the Risk of Preeclampsia.

    Science.gov (United States)

    Lee, Yunsung; Magnus, Per

    2018-04-01

    The etiology of preeclampsia is unknown. Tall women have been found to have lower incidence of preeclampsia. This points to a possible biological causal effect but may be because of socioeconomic confounding. We used paternal height as an unexposed control to examine confounding. The MoBa (Norwegian Mother and Child Cohort Study) was used to extract data on parental heights, maternal prepregnancy weight, other background factors, and pregnancy outcomes for 99 968 singleton births. Multiple logistic regression was used to estimate odds ratios for preeclampsia according to parental height. The adjusted odds ratio for preeclampsia was 0.74 (95% CI, 0.66-0.82) for women >172 cm as compared with women 186 cm was 1.03 (95% CI, 0.93-1.15) compared with men <178 cm. The association between maternal height and preeclampsia is unlikely to be because of confounding by familial, socioeconomic factors or by fetal genes related to height. The observed association between maternal height and preeclampsia merits further investigation. © 2018 American Heart Association, Inc.

  11. Optimization of bottom-hinged flap-type wave energy converter for a specific wave rose

    Science.gov (United States)

    Behzad, Hamed; Panahi, Roozbeh

    2017-06-01

    In this paper, we conducted a numerical analysis on the bottom-hinged flap-type Wave Energy Convertor (WEC). The basic model, implemented through the study using ANSYS-AQWA, has been validated by a three-dimensional physical model of a pitching vertical cylinder. Then, a systematic parametric assessment has been performed on stiffness, damping, and WEC direction against an incoming wave rose, resulting in an optimized flap-type WEC for a specific spot in the Persian Gulf. Here, stiffness is tuned to have a near-resonance condition considering the wave rose, while damping is modified to capture the highest energy for each device direction. Moreover, such sets of specifications have been checked at different directions to present the best combination of stiffness, damping, and device heading. It has been shown that for a real condition, including different wave heights, periods, and directions, it is very important to implement the methodology introduced here to guarantee device performance.

  12. A test-bed modeling study for wave resource assessment

    Science.gov (United States)

    Yang, Z.; Neary, V. S.; Wang, T.; Gunawan, B.; Dallman, A.

    2016-02-01

    Hindcasts from phase-averaged wave models are commonly used to estimate standard statistics used in wave energy resource assessments. However, the research community and wave energy converter industry is lacking a well-documented and consistent modeling approach for conducting these resource assessments at different phases of WEC project development, and at different spatial scales, e.g., from small-scale pilot study to large-scale commercial deployment. Therefore, it is necessary to evaluate current wave model codes, as well as limitations and knowledge gaps for predicting sea states, in order to establish best wave modeling practices, and to identify future research needs to improve wave prediction for resource assessment. This paper presents the first phase of an on-going modeling study to address these concerns. The modeling study is being conducted at a test-bed site off the Central Oregon Coast using two of the most widely-used third-generation wave models - WaveWatchIII and SWAN. A nested-grid modeling approach, with domain dimension ranging from global to regional scales, was used to provide wave spectral boundary condition to a local scale model domain, which has a spatial dimension around 60km by 60km and a grid resolution of 250m - 300m. Model results simulated by WaveWatchIII and SWAN in a structured-grid framework are compared to NOAA wave buoy data for the six wave parameters, including omnidirectional wave power, significant wave height, energy period, spectral width, direction of maximum directionally resolved wave power, and directionality coefficient. Model performance and computational efficiency are evaluated, and the best practices for wave resource assessments are discussed, based on a set of standard error statistics and model run times.

  13. Investigation of Wave Energy Converter Effects on Wave Fields: A Modeling Sensitivity Study in Monterey Bay CA.

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Jesse D.; Grace Chang; Jason Magalen; Craig Jones

    2014-08-01

    A n indust ry standard wave modeling tool was utilized to investigate model sensitivity to input parameters and wave energy converter ( WEC ) array deploym ent scenarios. Wave propagation was investigated d ownstream of the WECs to evaluate overall near - and far - field effects of WEC arrays. The sensitivity study illustrate d that b oth wave height and near - bottom orbital velocity we re subject to the largest pote ntial variations, each decreas ed in sensitivity as transmission coefficient increase d , as number and spacing of WEC devices decrease d , and as the deployment location move d offshore. Wave direction wa s affected consistently for all parameters and wave perio d was not affected (or negligibly affected) by varying model parameters or WEC configuration .

  14. Finite Amplitude Ocean Waves

    Indian Academy of Sciences (India)

    IAS Admin

    wavelength, they are called shallow water waves. In the ... Deep and intermediate water waves are dispersive as the velocity of these depends on wavelength. This is not the ..... generation processes, the finite amplitude wave theories are very ...

  15. Ethnic differences in trabecular meshwork height by optical coherence tomography.

    Science.gov (United States)

    Chen, Rebecca I; Barbosa, Diego T; Hsu, Chi-Hsin; Porco, Travis C; Lin, Shan C

    2015-04-01

    Differences in ocular anatomy may contribute to ethnic differences in glaucoma risk. Because the trabecular meshwork (TM) plays an important role in aqueous outflow, its anatomy in relation to at-risk populations may provide insight into a potential contributor to elevated intraocular pressure and thus to probability of glaucoma development. To investigate whether differences exist in TM height between ethnic groups. This prospective study took place from January 1, 2012, to December 31, 2013. Adult patients who self-reported as being of white, Asian, Hispanic, or African American ethnicity were recruited from ophthalmology clinics at the University of California, San Francisco. The TM height was assessed using spectral-domain anterior segment optical coherence tomography. Trabecular meshwork height was measured from the scleral spur to the Schwalbe line. We hypothesized that ethnicities with a higher prevalence of glaucoma would tend to have shorter TM heights. We collected data from 460 eyes of 291 participants after excluding 34 optical coherence tomographic scans owing to poor image quality. The final sample was 32.2% white, 45.1% Asian, 10.5% African American, and 12.1% Hispanic. There were 64.2% women, and the mean age was 68.1 years. The mean (SD) TM height among all eyes included in the study was 836 (131) μm. The mean (SD) TM height was characterized among white (851 [131] μm), Asian (843 [126] μm), Hispanic (822 [147] μm), and African American (771 [118] μm) persons. Ethnicity was not associated with TM height overall (P = .23, linear mixed regression model). However, the TM heights of African American participants (771 μm) were shorter than those of white (851 μm; adjusted difference 95% CI, -119.8 to -8.1; P = .02) and Asian (843 μm; adjusted difference 95% CI, -117.4 to -10.8; P = .02) participants. Although TM height is not associated with ethnicity overall, African American individuals have shorter TM heights compared with Asian and white

  16. Neural network cloud top pressure and height for MODIS

    Science.gov (United States)

    Håkansson, Nina; Adok, Claudia; Thoss, Anke; Scheirer, Ronald; Hörnquist, Sara

    2018-06-01

    Cloud top height retrieval from imager instruments is important for nowcasting and for satellite climate data records. A neural network approach for cloud top height retrieval from the imager instrument MODIS (Moderate Resolution Imaging Spectroradiometer) is presented. The neural networks are trained using cloud top layer pressure data from the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) dataset. Results are compared with two operational reference algorithms for cloud top height: the MODIS Collection 6 Level 2 height product and the cloud top temperature and height algorithm in the 2014 version of the NWC SAF (EUMETSAT (European Organization for the Exploitation of Meteorological Satellites) Satellite Application Facility on Support to Nowcasting and Very Short Range Forecasting) PPS (Polar Platform System). All three techniques are evaluated using both CALIOP and CPR (Cloud Profiling Radar for CloudSat (CLOUD SATellite)) height. Instruments like AVHRR (Advanced Very High Resolution Radiometer) and VIIRS (Visible Infrared Imaging Radiometer Suite) contain fewer channels useful for cloud top height retrievals than MODIS, therefore several different neural networks are investigated to test how infrared channel selection influences retrieval performance. Also a network with only channels available for the AVHRR1 instrument is trained and evaluated. To examine the contribution of different variables, networks with fewer variables are trained. It is shown that variables containing imager information for neighboring pixels are very important. The error distributions of the involved cloud top height algorithms are found to be non-Gaussian. Different descriptive statistic measures are presented and it is exemplified that bias and SD (standard deviation) can be misleading for non-Gaussian distributions. The median and mode are found to better describe the tendency of the error distributions and IQR (interquartile range) and MAE (mean absolute error) are found

  17. Prediction of the shape of inline wave force and free surface elevation using First Order Reliability Method (FORM)

    DEFF Research Database (Denmark)

    Ghadirian, Amin; Bredmose, Henrik; Schløer, Signe

    2017-01-01

    theory, that is, the most likely time history of inline force around a force peak of given value. The results of FORM and NewForce are linearly identical and show only minor deviations at second order. The FORM results are then compared to wave averaged measurements of the same criteria for crest height......In design of substructures for offshore wind turbines, the extreme wave loads which are of interest in Ultimate Limit States are often estimated by choosing extreme events from linear random sea states and replacing them by either stream function wave theory or the NewWave theory of a certain...... design wave height. As these wave theories super from limitations such as symmetry around the crest, other methods to estimate the wave loads are needed. In the present paper, the First Order Reliability Method, FORM, is used systematically to estimate the most likely extreme wave shapes. Two parameters...

  18. Hydraulic and Wave Aspects of Novorossiysk Bora

    Science.gov (United States)

    Shestakova, Anna A.; Moiseenko, Konstantin B.; Toropov, Pavel A.

    2018-02-01

    Bora in Novorossiysk (seaport on the Black Sea coast of the Caucasus) is one of the strongest and most prominent downslope windstorms on the territory of Russia. In this paper, we evaluate the applicability of the hydraulic and wave hypotheses, which are widely used for downslope winds around the world, to Novorossiysk bora on the basis of observational data, reanalysis, and mesoscale numerical modeling with WRF-ARW. It is shown that mechanism of formation of Novorossiysk bora is essentially mixed, which is expressed in the simultaneous presence of gravity waves breaking and a hydraulic jump, as well as in the significant variability of the contribution of wave processes to the windstorm dynamics. Effectiveness of each mechanism depends on the elevated inversion intensity and mean state critical level height. Most favorable conditions for both mechanisms working together are moderate or weak inversion and high or absent critical level.

  19. Wave Transformation Over Reefs: Evaluation of One-Dimensional Numerical Models

    Science.gov (United States)

    2009-01-01

    level estimates. DISCLAIMER: The contents of this report are not to be used for advertising , publication, or promotional purposes. Citation of trade...better with data for wave heights and mean water levels obtained with the DDD85 formula for these mono- chromatic waves. The RMSE values (rms errors

  20. Short-term statistics of waves measured off Ratnagiri, eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Amrutha, M.M.; SanilKumar, V.

    coast of India have been analyzed to study the short-term statistics of waves covering full one year period. The study indicates that the values of the observed maximum wave height as a function of duration are not consistent with the theoretical...

  1. Wave persistence in central Bay of Bengal during the southwest monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Sathe, P.V.; Gouveia, A.D.

    to compute wave persistence is suggested and persistence diagrams for different wave height levels are presented for both rough and calm conditions and their implications discussed. Except in one case, values of H@ds@@ exceeded 1 m, and over 60% of values...

  2. Augmented chaos-multiple linear regression approach for prediction of wave parameters

    Directory of Open Access Journals (Sweden)

    M.A. Ghorbani

    2017-06-01

    The inter-comparisons demonstrated that the Chaos-MLR and pure MLR models yield almost the same accuracy in predicting the significant wave heights and the zero-up-crossing wave periods. Whereas, the augmented Chaos-MLR model is performed better results in term of the prediction accuracy vis-a-vis the previous prediction applications of the same case study.

  3. An overview of the numerical and neural network accosts of ocean wave prediction

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.; Prabaharan, N.

    .8 1.2 1.6 Avg. Measured wave height (m) 0.0 0.4 0.8 1.2 1.6 Fo re ca ste d a vg . w av e h eig ht (m ) COPEDEC VI, 2003, Colombo, Sri Lanka 8 5. CONCLUSIONS The use of neural network for wave prediction will have future application...

  4. Waves in Gulf of Mannar and Palk Bay around Dhanushkodi, Tamil Nadu, India

    Digital Repository Service at National Institute of Oceanography (India)

    Gowthaman, R.; SanilKumar, V.; Dwarakish, G.S.; Mohan, S.S.; Singh, J.; AshokKumar, K.

    ., Wave characteris- tics off Visakhapatnam coast during a cyclone. Curr. Sci., 2004, 86, 1524–1529. 3. Nayak, B. U., Chandramohan, P. and Sakhardande, R. K., Sea- sonal distribution of wave heights off Yanam on the east coast of India. Indian J. Inst...

  5. Waves in the nearshore waters of northern Arabian Sea during the summer monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; Singh, J.; Pednekar, P.S.; Gowthaman, R.

    are provided by the NOAA-CIRES Climate Diagnostics Center, Boulder, Colarado at http://www.cdc.noaa.gov/. 3. Results 3.1 Wave height To identify the swell components from the measured data, the locally generated waves and the swell are separated. H m0...

  6. Wave modelling for the North Indian Ocean using MSMR analysed winds

    Digital Repository Service at National Institute of Oceanography (India)

    Vethamony, P.; Sudheesh, K.; Rupali, S.P.; Babu, M.T.; Jayakumar, S.; Saran, A; Basu, S.K.; Kumar, R.; Sarkar, A

    prediction when NCMRWF winds blended with MSMR winds are utilised in the wave model. A comparison between buoy and TOPEX wave heights of May 2000 at 4 buoy locations provides a good match, showing the merit of using altimeter data, wherever it is difficult...

  7. Experimental evaluation of the effect of wave focusing walls on the performance of the Sea-wave Slot-cone Generator

    International Nuclear Information System (INIS)

    Oliveira, P.; Taveira-Pinto, F.; Morais, T.; Rosa-Santos, P.

    2016-01-01

    Highlights: • The application of the Sea-wave Slot-cone Generator (SSG) in breakwaters is promising. • The use of wave focusing walls (WFW) improves the performance of the SSG technology. • The WFW concentrate the incident wave energy and increase the overtopping flow rates. • The design of new SSG devices should take into account the eventual use of WFW. • The use of WFW increased the annual energy production approximately to the double. - Abstract: The Sea-wave Slot-cone Generator (SSG) is a multi-level overtopping based wave energy converter that can be installed either nearshore or offshore. The installation in harbor breakwaters and in the shoreline presents several advantages despite the usual exposure to smaller waves than at offshore locations. This work analyzes the effect of wave focusing walls (i.e., wave concentrators) on the performance of isolated SSG units using a physical model built on a geometric scale of 1/40. Seven configurations were defined by changing the opening angle and the crest level of those elements. The use of wave concentrators proved to be advantageous since a wider wave front is captured and the run-up and overtopping phenomena are enhanced on the SSG ramp owing to the wave energy concentration (walls tapering effect). In fact, the total mean power captured increased for all SSG configurations with concentrators in comparison to the base configuration (without concentrators), regardless of the sea state considered. In terms of hydraulic performance, the gain associated to the use of wave concentrators depends on the characteristics of incident waves, being higher for the smaller significant wave heights and the shorter peak wave periods. The hydraulic efficiency, defined as the ratio between the total mean power captured per meter of SSG width and the wave power per meter width of the incident waves, increases with the significant wave height and reduces with the peak wave period in all tested SSG configurations. In

  8. Atom Wave Interferometers

    National Research Council Canada - National Science Library

    Pritchard, David

    1999-01-01

    Matter wave interferometers, in which de Broglie waves are coherently split and then recombined to produce interference fringes, have opened exciting new possibilities for precision and fundamental...

  9. Impacts of wave-induced circulation in the surf zone on wave setup

    Science.gov (United States)

    Guérin, Thomas; Bertin, Xavier; Coulombier, Thibault; de Bakker, Anouk

    2018-03-01

    Wave setup corresponds to the increase in mean water level along the coast associated with the breaking of short-waves and is of key importance for coastal dynamics, as it contributes to storm surges and the generation of undertows. Although overall well explained by the divergence of the momentum flux associated with short waves in the surf zone, several studies reported substantial underestimations along the coastline. This paper investigates the impacts of the wave-induced circulation that takes place in the surf zone on wave setup, based on the analysis of 3D modelling results. A 3D phase-averaged modelling system using a vortex force formalism is applied to hindcast an unpublished field experiment, carried out at a dissipative beach under moderate to very energetic wave conditions (Hm 0 = 6m at breaking and Tp = 22s). When using an adaptive wave breaking parameterisation based on the beach slope, model predictions for water levels, short waves and undertows improved by about 30%, with errors reducing to 0.10 m, 0.10 m and 0.09 m/s, respectively. The analysis of model results suggests a very limited impact of the vertical circulation on wave setup at this dissipative beach. When extending this analysis to idealized simulations for different beach slopes ranging from 0.01 to 0.05, it shows that the contribution of the vertical circulation (horizontal and vertical advection and vertical viscosity terms) becomes more and more relevant as the beach slope increases. In contrast, for a given beach slope, the wave height at the breaking point has a limited impact on the relative contribution of the vertical circulation on the wave setup. For a slope of 0.05, the contribution of the terms associated with the vertical circulation accounts for up to 17% (i.e. a 20% increase) of the total setup at the shoreline, which provides a new explanation for the underestimations reported in previously published studies.

  10. Accuracy of Jump-Mat Systems for Measuring Jump Height.

    Science.gov (United States)

    Pueo, Basilio; Lipinska, Patrycja; Jiménez-Olmedo, José M; Zmijewski, Piotr; Hopkins, Will G

    2017-08-01

    Vertical-jump tests are commonly used to evaluate lower-limb power of athletes and nonathletes. Several types of equipment are available for this purpose. To compare the error of measurement of 2 jump-mat systems (Chronojump-Boscosystem and Globus Ergo Tester) with that of a motion-capture system as a criterion and to determine the modifying effect of foot length on jump height. Thirty-one young adult men alternated 4 countermovement jumps with 4 squat jumps. Mean jump height and standard deviations representing technical error of measurement arising from each device and variability arising from the subjects themselves were estimated with a novel mixed model and evaluated via standardization and magnitude-based inference. The jump-mat systems produced nearly identical measures of jump height (differences in means and in technical errors of measurement ≤1 mm). Countermovement and squat-jump height were both 13.6 cm higher with motion capture (90% confidence limits ±0.3 cm), but this very large difference was reduced to small unclear differences when adjusted to a foot length of zero. Variability in countermovement and squat-jump height arising from the subjects was small (1.1 and 1.5 cm, respectively, 90% confidence limits ±0.3 cm); technical error of motion capture was similar in magnitude (1.7 and 1.6 cm, ±0.3 and ±0.4 cm), and that of the jump mats was similar or smaller (1.2 and 0.3 cm, ±0.5 and ±0.9 cm). The jump-mat systems provide trustworthy measurements for monitoring changes in jump height. Foot length can explain the substantially higher jump height observed with motion capture.

  11. Estrogen-mediated Height Control in Girls with Marfan Syndrome.

    Science.gov (United States)

    Lee, Dong-Yun; Hyun, Hye Sun; Huh, Rimm; Jin, Dong-Kyu; Kim, Duk-Kyung; Yoon, Byung-Koo; Choi, DooSeok

    2016-02-01

    This study evaluated the efficacy of a stepwise regimen of estradiol valerate for height control in girls with Marfan syndrome. Eight girls with Marfan syndrome who had completed estrogen treatment for height control were included. Estradiol valerate was started at a dose of 2 mg/day, and then was increased. The projected final height was estimated using the initial height percentile (on a disease-specific growth curve for Korean Marfan syndrome [gcPFHt]), and the initial bone age (baPFHt). After the estrogen treatment, the projected final height was compared to the actual final height (FHt). The median baseline chronological and bone age were 10.0 and 10.5 years, respectively. After a median of 36.5 months of treatment, the median FHt (172.6 cm) was shorter than the median gcPFHt (181.0 cm) and baPFHt (175.9 cm). In the six patients who started treatment before the age of 11 years, the median FHt (171.8 cm) was shorter than the median gcPFHt (181.5 cm) and baPFHt (177.4 cm) after treatment. The median differences between the FHt and gcPFHt and baPFHt were 9.2 and 8.3 cm, respectively. In two patients started treatment after the age of 11, the differences between FHt and gcPFHt, and baPFHt after treatment were -4 and 1.4 cm, and -1.2 and 0 cm for each case, respectively. A stepwise increasing regimen of estradiol valerate may be an effective treatment for height control in girls with Marfan syndrome, especially when started under 11 years old.

  12. Influence of real and virtual heights on standing balance.

    Science.gov (United States)

    Cleworth, Taylor W; Horslen, Brian C; Carpenter, Mark G

    2012-06-01

    Fear and anxiety induced by threatening scenarios, such as standing on elevated surfaces, have been shown to influence postural control in young adults. There is also a need to understand how postural threat influences postural control in populations with balance deficits and risk of falls. However, safety and feasibility issues limit opportunities to place such populations in physically threatening scenarios. Virtual reality (VR) has successfully been used to simulate threatening environments, although it is unclear whether the same postural changes can be elicited by changes in virtual and real threat conditions. Therefore, the purpose of this study was to compare the effects of real and virtual heights on changes to standing postural control, electrodermal activity (EDA) and psycho-social state. Seventeen subjects stood at low and high heights in both real and virtual environments matched in scale and visual detail. A repeated measures ANOVA revealed increases with height, independent of visual environment, in EDA, anxiety, fear, and center of pressure (COP) frequency, and decreases with height in perceived stability, balance confidence and COP amplitude. Interaction effects were seen for fear and COP mean position; where real elicited larger changes with height than VR. This study demonstrates the utility of VR, as simulated heights resulted in changes to postural, autonomic and psycho-social measures similar to those seen at real heights. As a result, VR may be a useful tool for studying threat related changes in postural control in populations at risk of falls, and to screen and rehabilitate balance deficits associated with fear and anxiety. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Predicting human height by Victorian and genomic methods.

    Science.gov (United States)

    Aulchenko, Yurii S; Struchalin, Maksim V; Belonogova, Nadezhda M; Axenovich, Tatiana I; Weedon, Michael N; Hofman, Albert; Uitterlinden, Andre G; Kayser, Manfred; Oostra, Ben A; van Duijn, Cornelia M; Janssens, A Cecile J W; Borodin, Pavel M

    2009-08-01

    In the Victorian era, Sir Francis Galton showed that 'when dealing with the transmission of stature from parents to children, the average height of the two parents, ... is all we need care to know about them' (1886). One hundred and twenty-two years after Galton's work was published, 54 loci showing strong statistical evidence for association to human height were described, providing us with potential genomic means of human height prediction. In a population-based study of 5748 people, we find that a 54-loci genomic profile explained 4-6% of the sex- and age-adjusted height variance, and had limited ability to discriminate tall/short people, as characterized by the area under the receiver-operating characteristic curve (AUC). In a family-based study of 550 people, with both parents having height measurements, we find that the Galtonian mid-parental prediction method explained 40% of the sex- and age-adjusted height variance, and showed high discriminative accuracy. We have also explored how much variance a genomic profile should explain to reach certain AUC values. For highly heritable traits such as height, we conclude that in applications in which parental phenotypic information is available (eg, medicine), the Victorian Galton's method will long stay unsurpassed, in terms of both discriminative accuracy and costs. For less heritable traits, and in situations in which parental information is not available (eg, forensics), genomic methods may provide an alternative, given that the variants determining an essential proportion of the trait's variation can be identified.

  14. Modelling of Performance of Caisson Type Breakwaters under Extreme Waves

    Science.gov (United States)

    Güney Doǧan, Gözde; Özyurt Tarakcıoǧlu, Gülizar; Baykal, Cüneyt

    2016-04-01

    Many coastal structures are designed without considering loads of tsunami-like waves or long waves although they are constructed in areas prone to encounter these waves. Performance of caisson type breakwaters under extreme swells is tested in Middle East Technical University (METU) Coastal and Ocean Engineering Laboratory. This paper presents the comparison of pressure measurements taken along the surface of caisson type breakwaters and obtained from numerical modelling of them using IH2VOF as well as damage behavior of the breakwater under the same extreme swells tested in a wave flume at METU. Experiments are conducted in the 1.5 m wide wave flume, which is divided into two parallel sections (0.74 m wide each). A piston type of wave maker is used to generate the long wave conditions located at one end of the wave basin. Water depth is determined as 0.4m and kept constant during the experiments. A caisson type breakwater is constructed to one side of the divided flume. The model scale, based on the Froude similitude law, is chosen as 1:50. 7 different wave conditions are applied in the tests as the wave period ranging from 14.6 s to 34.7 s, wave heights from 3.5 m to 7.5 m and steepness from 0.002 to 0.015 in prototype scale. The design wave parameters for the breakwater were 5m wave height and 9.5s wave period in prototype. To determine the damage of the breakwater which were designed according to this wave but tested under swell waves, video and photo analysis as well as breakwater profile measurements before and after each test are performed. Further investigations are carried out about the acting wave forces on the concrete blocks of the caisson structures via pressure measurements on the surfaces of these structures where the structures are fixed to the channel bottom minimizing. Finally, these pressure measurements will be compared with the results obtained from the numerical study using IH2VOF which is one of the RANS models that can be applied to simulate

  15. Transfer characteristics of optical profilers with respect to rectangular edge and step height measurement

    Science.gov (United States)

    Xie, Weichang; Hagemeier, Sebastian; Bischoff, Jörg; Mastylo, Rostyslav; Manske, Eberhard; Lehmann, Peter

    2017-06-01

    Optical profilers are mature instruments used in research and industry to study surface topography features. Although the corresponding standards are based on simple step height measurements, in practical applications these instruments are often used to study the fidelity of surface topography. In this context it is well-known that in certain situations a surface profile obtained by an optical profiler will differ from the real profile. With respect to practical applications such deviations often occur in the vicinity of steep walls and in cases of high aspect ratio. In this contribution we compare the transfer characteristics of different 3D optical profiler principles, namely white-light interferometry, focus sensing, and confocal microscopy. Experimental results demonstrate that the transfer characteristics do not only depend on the parameters of the optical measurement system (e. g. wavelength and coherence of light, numerical aperture, evaluated signal feature, polarization) but also on the properties of the measuring object such as step height, aspect ratio, material properties and homogeneity, rounding and steepness of the edges, surface roughness. As a result, typical artefacts such as batwings occur for certain parameter combinations, particularly at certain height-to-wavelength ratio (HWR) values. Understanding of the mechanisms behind these phenomena enables to reduce them by an appropriate parameter adaption. However, it is not only the edge artefacts, but also the position of an edge that may be changed due to the properties of the measuring object. In order to investigate the relevant effects theoretically, several models are introduced. These are based on either an extension of Richards-Wolf modeling or rigorous coupled wave analysis (RCWA). Although these models explain the experimental effects quite well they suffer from different limitations, so that a quantitative correspondence of theoretical modeling and experimental results is hard to achieve

  16. Wave energy potential: A forecasting system for the Mediterranean basin

    International Nuclear Information System (INIS)

    Carillo, Adriana; Sannino, Gianmaria; Lombardi, Emanuele

    2015-01-01

    ENEA is performing ocean wave modeling activities with the aim of both characterizing the Italian sea energy resource and providing the information necessary for the experimental at sea and operational phases of energy converters. Therefore a forecast system of sea waves and of the associated energy available has been developed and has been operatively running since June 2013. The forecasts are performed over the entire Mediterranean basin and, at a higher resolution, over ten sub-basins around the Italian coasts. The forecast system is here described along with the validation of the wave heights, performed by comparing them with the measurements from satellite sensors. [it

  17. Physiological pattern of lumbar disc height; Physiologisches Muster lumbaler Bandscheibenhoehen

    Energy Technology Data Exchange (ETDEWEB)

    Biggemann, M [Radiologische Klinik des Evangelischen Krankenhauses Bethesda, Duisburg (Germany); Frobin, W; Brinckmann, P [Muenster Univ. (Germany). Inst. fuer Experimentelle Biomechanik

    1997-07-01

    Purpose of this study is to present a new method of quantifying objectively the height of all discs in lateral radiographs of the lumbar spine and of analysing the normal craniocaudal sequence pattern of lumbar disc heights. Methods: The new parameter is the ventrally measured disc height corrected for the dependence on the angle of lordosis by normalisation to mean angles observed in the erect posture of healthy persons. To eliminate radiographic magnification, the corrected ventral height is related to the mean depth of the cranially adjoining vertebra. In this manner lumbar disc heights were objectively measured in young, mature and healthy persons (146 males and 65 females). The craniocaudal sequence pattern was analysed by mean values from all persons and by height differences of adjoining discs in each individual lumbar spine. Results: Mean normative values demonstrated an increase in disc height between L1/L2 and L4/L5 and a constant or decreasing disc height between L4/L5 and L5/S1. However, this `physiological sequence of disc height in the statistical mean` was observed in only 36% of normal males and 55% of normal females. Conclusion: The radiological pattern of the `physiological sequence of lumbar disc height` leads to a relevant portion of false positive pathological results especially at L4/L5. An increase of disc height from L4/L5 to L5/S1 may be normal. The recognition of decreased disc height should be based on an abrupt change in the heights of adjoining discs and not on a deviation from a craniocaudal sequence pattern. (orig.) [Deutsch] Ziel dieser Arbeit ist es, einen neuen Parameter zur objektiven Messung der Hoehen aller auf einer seitlichen Uebersichtsaufnahme der LWS erkennbaren Bandscheiben vorzustellen und die physiologische kraniokaudale Diskushoehensequenz neu zu dokumentieren. Methode: Bei dem neuen Messverfahren wird die Bandscheibenhoehe ventral gemessen, zur Korrektur ihrer Haltungsabhaengigkeit auf Standardwinkel (mittlere Winkel

  18. Comparison of ERA-Interim waves with buoy data in the eastern Arabian Sea during high waves

    Digital Repository Service at National Institute of Oceanography (India)

    Shanas, P.R.; SanilKumar, V.

    at two locations in eastern Arabian Sea One location is a deep water location and another one is a shallow water location The comparison of significant wave height (SWH) between ERA dataset and buoy data at both the locations shows good correlation...

  19. ANALYSIS AND CORRECTION OF SYSTEMATIC HEIGHT MODEL ERRORS

    Directory of Open Access Journals (Sweden)

    K. Jacobsen

    2016-06-01

    Full Text Available The geometry of digital height models (DHM determined with optical satellite stereo combinations depends upon the image orientation, influenced by the satellite camera, the system calibration and attitude registration. As standard these days the image orientation is available in form of rational polynomial coefficients (RPC. Usually a bias correction of the RPC based on ground control points is required. In most cases the bias correction requires affine transformation, sometimes only shifts, in image or object space. For some satellites and some cases, as caused by small base length, such an image orientation does not lead to the possible accuracy of height models. As reported e.g. by Yong-hua et al. 2015 and Zhang et al. 2015, especially the Chinese stereo satellite ZiYuan-3 (ZY-3 has a limited calibration accuracy and just an attitude recording of 4 Hz which may not be satisfying. Zhang et al. 2015 tried to improve the attitude based on the color sensor bands of ZY-3, but the color images are not always available as also detailed satellite orientation information. There is a tendency of systematic deformation at a Pléiades tri-stereo combination with small base length. The small base length enlarges small systematic errors to object space. But also in some other satellite stereo combinations systematic height model errors have been detected. The largest influence is the not satisfying leveling of height models, but also low frequency height deformations can be seen. A tilt of the DHM by theory can be eliminated by ground control points (GCP, but often the GCP accuracy and distribution is not optimal, not allowing a correct leveling of the height model. In addition a model deformation at GCP locations may lead to not optimal DHM leveling. Supported by reference height models better accuracy has been reached. As reference height model the Shuttle Radar Topography Mission (SRTM digital surface model (DSM or the new AW3D30 DSM, based on ALOS

  20. Coral reef structural complexity provides important coastal protection from waves under rising sea levels

    Science.gov (United States)

    Harris, Daniel L.; Rovere, Alessio; Casella, Elisa; Power, Hannah; Canavesio, Remy; Collin, Antoine; Pomeroy, Andrew; Webster, Jody M.; Parravicini, Valeriano

    2018-01-01

    Coral reefs are diverse ecosystems that support millions of people worldwide by providing coastal protection from waves. Climate change and human impacts are leading to degraded coral reefs and to rising sea levels, posing concerns for the protection of tropical coastal regions in the near future. We use a wave dissipation model calibrated with empirical wave data to calculate the future increase of back-reef wave height. We show that, in the near future, the structural complexity of coral reefs is more important than sea-level rise in determining the coastal protection provided by coral reefs from average waves. We also show that a significant increase in average wave heights could occur at present sea level if there is sustained degradation of benthic structural complexity. Our results highlight that maintaining the structural complexity of coral reefs is key to ensure coastal protection on tropical coastlines in the future. PMID:29503866

  1. Foot and Ankle Kinematics During Descent From Varying Step Heights.

    Science.gov (United States)

    Gerstle, Emily E; O'Connor, Kristian; Keenan, Kevin G; Cobb, Stephen C

    2017-12-01

    In the general population, one-third of incidences during step negotiation occur during the transition to level walking. Furthermore, falls during curb negotiation are a common cause of injury in older adults. Distal foot kinematics may be an important factor in determining injury risk associated with transition step negotiation. The purpose of this study was to identify foot and ankle kinematics of uninjured individuals during descent from varying step heights. A 7-segment foot model was used to quantify kinematics as participants walked on a level walkway, stepped down a single step (heights: 5 cm, 15 cm, 25 cm), and continued walking. As step height increased, landing strategy transitioned from the rearfoot to the forefoot, and the rearfoot, lateral and medial midfoot, and medial forefoot became more plantar flexed. During weight acceptance, sagittal plane range of motion of the rearfoot, lateral midfoot, and medial and lateral forefoot increased as step height increased. The changes in landing strategy and distal foot function suggest a less stable ankle position at initial contact and increased demand on the distal foot at initial contact and through the weight acceptance phase of transition step negotiation as step height increases.

  2. Falls from heights in and around the city of Batman.

    Science.gov (United States)

    Al, Behçet; Yildirim, Cuma; Coban, Sacid

    2009-03-01

    We evaluated the demographic data, mortality rates, fall causes, and post-mortem findings of individuals who fell from heights. Five hundred thirty-eight patients who sustained injuries after an accidental fall from heights were entered into the study. Our cases were collected prospectively in Batman over a seven- month period. The mean age was 12.4+/-3.22 years (3 months-98 years); 56.5% of patients were under 6 years old and 83.5% were under 20 years old. The mean fall height was 3.2+/-2.4 m. The mortality rate was 2.2%, and was highest among the patients who fell from flat-roofed houses. The most common injuries were to the head, and 100% of those who died had a head injury. Six patients were followed because of abdominal bleeding and 141 patients due to extremity fractures; 6.7% of patients were operated on and 83.8% of patients were treated in the emergency department. The results of this study were at variance with literature data with respect to the following: falls from heights were most common in the 0-5 years of age group. Craniocerebral trauma is the most common injury in fatal falls. Males had a higher rate of falls from height than females.

  3. Comparison of mixing height parameterizations with profiles measurements

    Energy Technology Data Exchange (ETDEWEB)

    Jaquier, A.; Stuebi, R.; Tercier, P. [Swiss Meteorological Inst., SMI - MeteoSwiss, Payerne (Switzerland)

    1997-10-01

    Different meteorological pre-processors for dispersion studies are available to derive the atmospheric boundary layer mixing height (MH). The analysis of their performances has been reviewed in the framework of the European COST Action 710. In this project, the computed mixing height values have been compared with data derived mostly from aero-logical sounding analysis and Sodar measurements. Since then, a new analysis of a low-tropospheric wind profiler (WP) data has been performed taking advantage of its high data sampling ({delta}t {approx} 30 sec.). The comparison between these recent results and aero-logical sounding, Sodar data, as well as to meteorological pre-processors calculations are reported for three periods of several days corresponding to different meteorological situations. In convective conditions, the pre-processors give reasonable level, the mixing height growing rate is in fair agreement with the measured one. In stable cloudy daytime conditions, the modeled mixing height does not correspond to any measured height. (LN)

  4. Changes in interdental papillae heights following alignment of anterior teeth.

    Science.gov (United States)

    Kandasamy, Sanjivan; Goonewardene, Mithran; Tennant, Marc

    2007-05-01

    Orthodontic alignment of overlapped incisors can reduce the apparent heights of the interdental papillae leading to unsightly dark triangles or open gingival embrasures. To determine if certain pretreatment contact point relationships between the maxillary anterior teeth were accompanied by changes in the heights of the interdental papillae after orthodontic alignment. Pre- and post-treatment intra-oral 35 mm slides, lateral cephalometric radiographs and study casts of 143 patients (60 males, 83 females) between 13 and 16 years of age were used. The patients had diastamata closed, imbricated teeth aligned and palatally or labially placed teeth repositioned. A sample of 25 patients (12 males, 13 females) between 13 and 16 years of age who had well-aligned anterior teeth at the start of treatment acted as a control group. All patients were treated for approximately 18 months. The clinical crowns of the maxillary incisors and the heights of the interdental papilla between the incisors were measured on projected images of the slides. The percentage increases or reductions in the heights of the interdental papillae were compared. The heights of the interdental papillae increased following palatal movement of labially placed (p teeth and the intrusion of one tooth relative to another. On the other hand, dark triangles are more likely to develop following labial movement of imbricated or palatally placed incisors and closure of a diastema. Clinicians should be alert to the possibility of dark triangles developing in the latter group, particularly in older patients.

  5. Lee waves: Benign and malignant

    Science.gov (United States)

    Wurtele, M. G.; Datta, A.; Sharman, R. D.

    1993-01-01

    The flow of an incompressible fluid over an obstacle will produce an oscillation in which buoyancy is the restoring force, called a gravity wave. For disturbances of this scale, the atmosphere may be treated as dynamically incompressible, even though there exists a mean static upward density gradient. Even in the linear approximation - i.e., for small disturbances - this model explains a great many of the flow phenomena observed in the lee of mountains. However, nonlinearities do arise importantly, in three ways: (1) through amplification due to the decrease of mean density with height; (2) through the large (scaled) size of the obstacle, such as a mountain range; and (3) from dynamically singular levels in the fluid field. These effects produce a complicated array of phenomena - large departure of the streamlines from their equilibrium levels, high winds, generation of small scales, turbulence, etc. - that present hazards to aircraft and to lee surface areas. The nonlinear disturbances also interact with the larger-scale flow in such a manner as to impact global weather forecasts and the climatological momentum balance. If there is no dynamic barrier, these waves can penetrate vertically into the middle atmosphere (30-100 km), where recent observations show them to be of a length scale that must involve the coriolis force in any modeling. At these altitudes, the amplitude of the waves is very large, and the phenomena associated with these wave dynamics are being studied with a view to their potential impact on high performance aircraft, including the projected National Aerospace Plane (NASP). The presentation shows the results of analysis and of state-of-the-art numerical simulations, validated where possible by observational data, and illustrated with photographs from nature.

  6. Wave and offshore wind potential for the island of Tenerife

    International Nuclear Information System (INIS)

    Veigas, M.; Iglesias, G.

    2013-01-01

    Highlights: • The island aims to reduce its carbon footprint by developing renewable energy. • The substantial wave and offshore wind resources around the island are examined. • One area is appropriate for installing a hybrid wave–offshore wind farm. - Abstract: The island of Tenerife, a UNESCO Biosphere Reserve in the Atlantic Ocean, aims to be energy self-sufficient in order to reduce its carbon footprint. To accomplish this goal it should develop the renewable sources, in particular wave and offshore wind energy. The objectives of this work are twofold; (i) to characterize the wave and offshore wind power distribution around the island and (ii) to determine which offshore area is best suited for their exploitation, taking into account the resource and other conditioning factors such as the bathymetry, distance to the coastline and ports, and offshore zoning. To carry out this research, hindcast wave and wind data obtained with numerical models are used alongside observations from meteorological stations. One area, in the vicinity of Puerto de la Cruz, is identified as having great potential for installing a hybrid floating wave–wind farm. Both resources are characterized for the area selected: the wave resource in terms of wave directions, significant wave heights and energy periods; the offshore wind resource in terms of directions and speeds in addition to the seasonality for the both resources. It is found that most of the wave resource is provided by N and NNW waves with significant wave heights between 1.5 m and 3.0 m and energy periods between 10 s and 14 s. It follows that the Wave Energy Converters deployed in the area should have maximum efficiency in those ranges. As for the offshore wind resource, most of the energy corresponds to NNE and NE winds with speeds between 9 and 14 m s −1 , which should be taken into account when selecting the offshore wind turbines

  7. Leading Wave Amplitude of a Tsunami

    Science.gov (United States)

    Kanoglu, U.

    2015-12-01

    Okal and Synolakis (EGU General Assembly 2015, Geophysical Research Abstracts-Vol. 17-7622) recently discussed that why the maximum amplitude of a tsunami might not occur for the first wave. Okal and Synolakis list observations from 2011 Japan tsunami, which reached to Papeete, Tahiti with a fourth wave being largest and 72 min later after the first wave; 1960 Chilean tsunami reached Hilo, Hawaii with a maximum wave arriving 1 hour later with a height of 5m, first wave being only 1.2m. Largest later waves is a problem not only for local authorities both in terms of warning to the public and rescue efforts but also mislead the public thinking that it is safe to return shoreline or evacuated site after arrival of the first wave. Okal and Synolakis considered Hammack's (1972, Ph.D. Dissertation, Calif. Inst. Tech., 261 pp., Pasadena) linear dispersive analytical solution with a tsunami generation through an uplifting of a circular plug on the ocean floor. They performed parametric study for the radius of the plug and the depth of the ocean since these are the independent scaling lengths in the problem. They identified transition distance, as the second wave being larger, regarding the parameters of the problem. Here, we extend their analysis to an initial wave field with a finite crest length and, in addition, to a most common tsunami initial wave form of N-wave as presented by Tadepalli and Synolakis (1994, Proc. R. Soc. A: Math. Phys. Eng. Sci., 445, 99-112). We compare our results with non-dispersive linear shallow water wave results as presented by Kanoglu et al. (2013, Proc. R. Soc. A: Math. Phys. Eng. Sci., 469, 20130015), investigating focusing feature. We discuss the results both in terms of leading wave amplitude and tsunami focusing. Acknowledgment: The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no 603839 (Project ASTARTE - Assessment, Strategy and Risk

  8. Application of Soft Computing Tools for Wave Prediction at Specific Locations in the Arabian Sea Using Moored Buoy Observations

    Directory of Open Access Journals (Sweden)

    J. Vimala

    2012-12-01

    Full Text Available The knowledge of design and operational values of significant wave heights is perhaps the single most important input needed in ocean engineering studies. Conventionally such information is obtained using classical statistical analysis and stochastic methods. As the causative variables are innumerable and underlying physics is too complicated, the results obtained from the numerical models may not always be very satisfactory. Soft computing tools like Artificial Neural Network (ANN and Adaptive Network based Fuzzy Inference System (ANFIS may therefore be useful to predict significant wave heights in some situations. The study is aimed at forecasting of significant wave height values in real time over a period of 24hrs at certain locations in Indian seas using the models of ANN and ANFIS. The data for the work were collected by National Institute of Ocean Technology, Chennai. It was found that the predictions of wave heights can be done by both methods with equal efficiency and satisfaction.

  9. The wave climate of the Northeast Atlantic over the period 1955-1994: the WASA wave hindcast

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, H.; Rosenthal, W.; Stawarz, M. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Gewaesserphysik; Carretero, J.C.; Gomez, M.; Lozano, I.; Serrano, O. [Programa de Clima Maritimo (Puertos del Estado), Madrid (Spain); Reistad, M. [Det Norske Meteorologiske Inst., Bergen (Norway)

    1997-12-31

    The European project ``waves and storms in the North Atlantic`` (WASA) has been set up to prove, or to disprove, hypotheses of a worsening storm and wave climate in the Northeast Atlantic and adjacent seas in the present century. A major obstacle for assessing changes in storm and wave conditions are inhomogeneities in the observational records, both in the local observations and in the analysed products, which usually produce an artificial increase of extreme winds and waves. Therefore, changes in the wave climate were assessed with a state-of-the-art wave model using wind analyses. Within the scope of the WASA project, a 40 year reconstruction (1955-1994) of the wave climate in the North Atlantic was completed using the WAM wave model. The input wind fields were assumed to be reasonably homogeneous with time in the area south of 70 N and east of 20 W, and it was expected that the hindcast wave data would reliably describe the space-time evolution of wave conditions in this area. The results of the hindcast experiment are presented in this article. The main conclusion was that the wave climate in most of the Northeast Atlantic and in the North Sea has undergone significant variations on time scales of decades. Part of variability was found to be related to the North Atlantic oscillation. As a general result we noted an increase of the maximum annual significant wave height over the last 40 years of about 5 to 10 cm/year for large parts of the Northeast Atlantic, north of the North Sea. There was also a slight increase of probabilities of high waves derived from conventional extreme value statistics in northwest approaches to the North Sea. Similar trends of the extreme waves were found in a scenario of future wave climate at a time of doubled C0{sub 2} concentration in the atmosphere. (orig.) 28 refs.

  10. Experimental validation of a mathematical model for seabed liquefaction in waves

    DEFF Research Database (Denmark)

    Sumer, B. Mutlu; Kirca, Özgür; Fredsøe, Jørgen

    2011-01-01

    This paper summarizes the results of an experimental study directed towards the validation of a mathematical model for the buildup of pore water pressure and resulting liquefaction of marine soils under progressive waves. Experiments were conducted under controlled conditions with silt ( d50 = 0.......070 mm) in a wave flume with a soil pit. Waves with wave heights in the range 7.7-18 cm with the water depth 55 cm and the wave period 1.6 s enabled us to study both the liquefaction and no-liquefaction regime pore water pressure buildup. The experimental data was used to validate the model. A numerical...

  11. Variation of boundary-layer wind spectra with height

    DEFF Research Database (Denmark)

    Larsén, Xiaoli Guo; Petersen, Erik L.; Larsen, Søren Ejling

    2018-01-01

    This study revisits the height dependence of the wind speed power spectrum from the synoptic scale to the spectral gap. Measurements from cup anemometers and sonics at heights of 15 m to 244 m are used. The measurements are from one land site, one coastal land‐based site and three offshore sites...... the atmospheric tide. The second finding regards the height dependence of the general spectrum. We describe the dependence through a so‐called effective roughness, which is calculated from wind spectra and represents the energy removal at different frequencies, and thus surface conditions in the footprint areas....... The generalizable spectral properties of winds presented herein may prove useful for validating numerical models....

  12. Retrieving Smoke Aerosol Height from DSCOVR/EPIC

    Science.gov (United States)

    Xu, X.; Wang, J.; Wang, Y.

    2017-12-01

    Unlike industrial pollutant particles that are often confined within the planetary boundary layer, smoke from forest and agriculture fires can inject massive carbonaceous aerosols into the upper troposphere due to the intense pyro-convection. Sensitivity of weather and climate to absorbing carbonaceous aerosols is regulated by the altitude of those aerosol layers. However, aerosol height information remains limited from passive satellite sensors. Here we present an algorithm to estimate smoke aerosol height from radiances in the oxygen A and B bands measured by the Earth Polychromatic Imaging Camera (EPIC) from the Deep Space Climate Observatory (DSCOVR). With a suit of case studies and validation efforts, we demonstrate that smoke aerosol height can be well retrieved over both ocean and land surfaces multiple times daily.

  13. FERDO/FERD, Unfolding of Pulse-Height Spectrometer Spectra

    International Nuclear Information System (INIS)

    Rust, B.W.; Ingersoll, D.T.; Burrus, W.R.

    1985-01-01

    1 - Description of problem or function: FERDO and FERD are unfolding codes which can be used to correct observed pulse-height distributions for the non-ideal response of a pulse-height spectrometer or to solve poorly conditioned linear equations. 2 - Method of solution: It is assumed that the response of the spectrometer is given by Ax = b, where A is the spectrometer response function matrix, x is the unknown spectrum, and b is the pulse-height distribution. FERDO does not resolve directly for x but instead solves for p = Wx, where W is a 'window function matrix'. Typically, W is the resolution function of an ideal spectrometer which has a single Gaussian response. The effective resolution of the unfolding solution may be varied by the choice of W. Confidence intervals are found for each element of the solution p

  14. Improved pulse-height store for A/D conversion

    Energy Technology Data Exchange (ETDEWEB)

    Casoli, P [Montedel S.p.a., Laben Division, Via Bassini 15, Milano, Italy; Maranesi, P [Politecnico di Milano (Italy). Centro Studi Nucleari E. Fermi

    1979-11-15

    A new pulse-height store is described. Suitable contrivances improve integral linearity and reduce the differential errors that generally occur at signal amplitudes near the lower threshold. No degradations appear at high rates of input events. The electrical specifications of the pulse-height store are determined through a series of measurements described in the final part of the paper. In order to test the circuit in the most significant way, it has been connected to a fast successive-approximation conversion module which uses the sliding-scale technique for channel width equalisation, thus implementing a complete analog-to-digital converter (ADC) for nuclear spectrometry. The performances of the pulse-height store have been deduced from the behavior of the whole system.

  15. Climatology and evolution of the mixing height over water

    Energy Technology Data Exchange (ETDEWEB)

    Sempreviva, A.M. [Istituto di Fisica dell`Atmosfera, CNR, Rome (Italy); Grynig, S.E. [Risoe National Lab., Roskilde (Denmark)

    1997-10-01

    In this paper we present results from an experimental investigation on the height of the mixed layer h, using a meteorological station located on the Danish island of Anholt. The station was operational for two years from September 1990 to October 1992. We present the analysis of two years of radio-sounding showing the average daily evolution of h. Furthermore observations of the mixed layer growth under near-neutral and unstable atmospheric conditions during six consecutive days has been modelled using a simple zero-order mixed-layer height model. Finally we have compared the evolution of the mixing height from the model with the evolution of the correlation coefficient between temperature and humidity to study the influence of the deepness of the convective layer on the mechanism of the correlation between temperature and humidity in the surface layer. (au)

  16. Evaluation of an Approximate Method for Incorporating Floating Docks in Harbor Wave Prediction Models

    Science.gov (United States)

    2005-11-25

    fact, Koutandos et al. (2004) even now have had to limit their work only to the x–z plane while using a similar approach. In this paper, therefore, we...breakwater Koutandos et al. (2004) have presented data pertaining to transmission coefficients for waves passing a fixed, infinitely long, floating...4. Values of A and B for determining α. Fig. 5. Wave height comparison with data presented in Koutandos et al. (2004). Fig. 6. Wave transmission past

  17. Extreme coastal erosion enhanced by anomalous extratropical storm wave direction.

    Science.gov (United States)

    Harley, Mitchell D; Turner, Ian L; Kinsela, Michael A; Middleton, Jason H; Mumford, Peter J; Splinter, Kristen D; Phillips, Matthew S; Simmons, Joshua A; Hanslow, David J; Short, Andrew D

    2017-07-20

    Extratropical cyclones (ETCs) are the primary driver of large-scale episodic beach erosion along coastlines in temperate regions. However, key drivers of the magnitude and regional variability in rapid morphological changes caused by ETCs at the coast remain poorly understood. Here we analyze an unprecedented dataset of high-resolution regional-scale morphological response to an ETC that impacted southeast Australia, and evaluate the new observations within the context of an existing long-term coastal monitoring program. This ETC was characterized by moderate intensity (for this regional setting) deepwater wave heights, but an anomalous wave direction approximately 45 degrees more counter-clockwise than average. The magnitude of measured beach volume change was the largest in four decades at the long-term monitoring site and, at the regional scale, commensurate with that observed due to extreme North Atlantic hurricanes. Spatial variability in morphological response across the study region was predominantly controlled by alongshore gradients in storm wave energy flux and local coastline alignment relative to storm wave direction. We attribute the severity of coastal erosion observed due to this ETC primarily to its anomalous wave direction, and call for greater research on the impacts of changing storm wave directionality in addition to projected future changes in wave heights.

  18. Financial Rogue Waves

    International Nuclear Information System (INIS)

    Yan Zhenya

    2010-01-01

    We analytically give the financial rogue waves in the nonlinear option pricing model due to Ivancevic, which is nonlinear wave alternative of the Black-Scholes model. These rogue wave solutions may he used to describe the possible physical mechanisms for rogue wave phenomenon in financial markets and related fields.

  19. Hierarchical wave functions revisited

    International Nuclear Information System (INIS)

    Li Dingping.

    1997-11-01

    We study the hierarchical wave functions on a sphere and on a torus. We simplify some wave functions on a sphere or a torus using the analytic properties of wave functions. The open question, the construction of the wave function for quasi electron excitation on a torus, is also solved in this paper. (author)

  20. A Simple Wave Driver

    Science.gov (United States)

    Temiz, Burak Kagan; Yavuz, Ahmet

    2015-01-01

    This study was done to develop a simple and inexpensive wave driver that can be used in experiments on string waves. The wave driver was made using a battery-operated toy car, and the apparatus can be used to produce string waves at a fixed frequency. The working principle of the apparatus is as follows: shortly after the car is turned on, the…

  1. Program Merges SAR Data on Terrain and Vegetation Heights

    Science.gov (United States)

    Siqueira, Paul; Hensley, Scott; Rodriguez, Ernesto; Simard, Marc

    2007-01-01

    X/P Merge is a computer program that estimates ground-surface elevations and vegetation heights from multiple sets of data acquired by the GeoSAR instrument [a terrain-mapping synthetic-aperture radar (SAR) system that operates in the X and bands]. X/P Merge software combines data from X- and P-band digital elevation models, SAR backscatter magnitudes, and interferometric correlation magnitudes into a simplified set of output topographical maps of ground-surface elevation and tree height.

  2. Vowel Height Allophony and Dorsal Place Contrasts in Cochabamba Quechua.

    Science.gov (United States)

    Gallagher, Gillian

    2016-01-01

    This paper reports on the results of two studies investigating the role of allophony in cueing phonemic contrasts. In Cochabamba Quechua, the uvularvelar place distinction is often cued by additional differences in the height of the surrounding vowels. An acoustic study documents the lowering effect of a preceding tautomorphemic or a following heteromorphemic uvular on the high vowels /i u/. A discrimination study finds that vowel height is a significant cue to the velar-uvular place contrast. These findings support a view of contrasts as collections of distinguishing properties, as opposed to oppositions in a single distinctive feature. © 2016 S. Karger AG, Basel.

  3. Sampling rare fluctuations of height in the Oslo ricepile model

    International Nuclear Information System (INIS)

    Pradhan, Punyabrata; Dhar, Deepak

    2007-01-01

    We describe a new Monte Carlo algorithm for studying large deviations of the height of the pile from its mean value in the Oslo ricepile model. We have used it to generate events which have probabilities of order 10 -1000 . These simulations check our qualitative argument (Pradhan P and Dhar D 2006 Phys. Rev. E 73 021303) that in the steady state of the Oslo ricepile model the probability of large negative height fluctuations Δh = -αL about the mean varies as exp(-κα 4 L 3 ) as L → ∞ with α held fixed and κ > 0

  4. Characteristics of emulsion chamber family events produced at low heights

    International Nuclear Information System (INIS)

    Jing, G.; Jing, C.; Zhu, Q.; Ding, L.

    1985-01-01

    The uncertainty of primary cosmic ray composition at 10 to the 14th power -10 to the 16th power eV is well known making the study of nuclear interaction mechanisms more difficult. Experimentally if one can identify effectively the family events produced at low heights, then an induced by primary protons might be separated. In this paper an attempt is made to simulate a family of events under the conditions of a mountain emulsion chamber experiments using a reasonable model. The aim is to search for the dependence of some experimentally observable quantities on the interaction height

  5. Ultrasonic creeping wave test technique for dissimilar metal weld

    International Nuclear Information System (INIS)

    Yuan Jianzhong; Shang Junmin; Yan Zhi; Yuan Guanghua; Zhang Guofeng

    2009-01-01

    To solve the problem encountered in the defect inspection of the surface and near-surface of dissimilar metal weld effectively, a new ultrasonic creeping wave test technique is developed. In this paper, the test technique and its experimental verification are mainly described. The verification results show that linear defect, which is similar to the defect found in liquid penetrant test, on the surface and near-surface of dissimilar metal weld can be detected effectively, by using ultrasonic creeping wave test technique. And the depth, length and height of the defect can be determined easily. The effective covering depth of ultrasonic creeping wave test technique will reach 0-9 mm. Meanwhile, the planar defect, with equivalent area more than 3 mm 2 , existed in welds can be detected efficiently. So, accurate measurement, which self height dimension of planar defect is above 2 mm, will be realized. (authors)

  6. Sea Surface Height, Absolute, Aviso, 0.25 degrees, Global, Science Quality

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Aviso Absolute Sea Surface Height is the Sea Surface Height Deviation plus the long term mean dynamic height. This is Science Quality data.

  7. Nonlinear MHD Waves in a Prominence Foot

    Science.gov (United States)

    Ofman, L.; Knizhnik, K.; Kucera, T.; Schmieder, B.

    2015-11-01

    We study nonlinear waves in a prominence foot using a 2.5D MHD model motivated by recent high-resolution observations with Hinode/Solar Optical Telescope in Ca ii emission of a prominence on 2012 October 10 showing highly dynamic small-scale motions in the prominence material. Observations of Hα intensities and of Doppler shifts show similar propagating fluctuations. However, the optically thick nature of the emission lines inhibits a unique quantitative interpretation in terms of density. Nevertheless, we find evidence of nonlinear wave activity in the prominence foot by examining the relative magnitude of the fluctuation intensity (δI/I ˜ δn/n). The waves are evident as significant density fluctuations that vary with height and apparently travel upward from the chromosphere into the prominence material with quasi-periodic fluctuations with a typical period in the range of 5-11 minutes and wavelengths <2000 km. Recent Doppler shift observations show the transverse displacement of the propagating waves. The magnetic field was measured with the THEMIS instrument and was found to be 5-14 G. For the typical prominence density the corresponding fast magnetosonic speed is ˜20 km s-1, in qualitative agreement with the propagation speed of the detected waves. The 2.5D MHD numerical model is constrained with the typical parameters of the prominence waves seen in observations. Our numerical results reproduce the nonlinear fast magnetosonic waves and provide strong support for the presence of these waves in the prominence foot. We also explore gravitational MHD oscillations of the heavy prominence foot material supported by dipped magnetic field structure.

  8. NONLINEAR MHD WAVES IN A PROMINENCE FOOT

    Energy Technology Data Exchange (ETDEWEB)

    Ofman, L. [Catholic University of America, Washington, DC 20064 (United States); Knizhnik, K.; Kucera, T. [NASA Goddard Space Flight Center, Code 671, Greenbelt, MD 20771 (United States); Schmieder, B. [LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris-Diderot, Sorbonne Paris Cit, 5 place Jules Janssen, F-92195 Meudon (France)

    2015-11-10

    We study nonlinear waves in a prominence foot using a 2.5D MHD model motivated by recent high-resolution observations with Hinode/Solar Optical Telescope in Ca ii emission of a prominence on 2012 October 10 showing highly dynamic small-scale motions in the prominence material. Observations of Hα intensities and of Doppler shifts show similar propagating fluctuations. However, the optically thick nature of the emission lines inhibits a unique quantitative interpretation in terms of density. Nevertheless, we find evidence of nonlinear wave activity in the prominence foot by examining the relative magnitude of the fluctuation intensity (δI/I ∼ δn/n). The waves are evident as significant density fluctuations that vary with height and apparently travel upward from the chromosphere into the prominence material with quasi-periodic fluctuations with a typical period in the range of 5–11 minutes and wavelengths <2000 km. Recent Doppler shift observations show the transverse displacement of the propagating waves. The magnetic field was measured with the THEMIS instrument and was found to be 5–14 G. For the typical prominence density the corresponding fast magnetosonic speed is ∼20 km s{sup −1}, in qualitative agreement with the propagation speed of the detected waves. The 2.5D MHD numerical model is constrained with the typical parameters of the prominence waves seen in observations. Our numerical results reproduce the nonlinear fast magnetosonic waves and provide strong support for the presence of these waves in the prominence foot. We also explore gravitational MHD oscillations of the heavy prominence foot material supported by dipped magnetic field structure.

  9. Experimental investigation on the hydrodynamic performance of a wave energy converter

    Science.gov (United States)

    Zheng, Xiong-bo; Ma, Yong; Zhang, Liang; Jiang, Jin; Liu, Heng-xu

    2017-06-01

    Wave energy is an important type of marine renewable energy. A wave energy converter (WEC) moored with two floating bodies was developed in the present study. To analyze the dynamic performance of the WEC, an experimental device was designed and tested in a tank. The experiment focused on the factors which impact the motion and energy conversion performance of the WEC. Dynamic performance was evaluated by the relative displacements and velocities of the oscillator and carrier which served as the floating bodies of WEC. Four factors were tested, i.e. wave height, wave period, power take-off (PTO) damping, and mass ratio ( R M) of the oscillator and carrier. Experimental results show that these factors greatly affect the energy conversion performance, especially when the wave period matches R M and PTO damping. According to the results, we conclude that: (a) the maximization of the relative displacements and velocities leads to the maximization of the energy conversion efficiency; (b) the larger the wave height, the higher the energy conversion efficiency will be; (c) the relationships of energy conversion efficiency with wave period, PTO damping, and R M are nonlinear, but the maximum efficiency is obtained when these three factors are optimally matched. Experimental results demonstrated that the energy conversion efficiency reached the peak at 28.62% when the wave height was 120 mm, wave period was 1.0 s, R M was 0.21, and the PTO damping was corresponding to the resistance of 100 Ω.

  10. The response of the southwest Western Australian wave climate to Indian Ocean climate variability

    Science.gov (United States)

    Wandres, Moritz; Pattiaratchi, Charitha; Hetzel, Yasha; Wijeratne, E. M. S.

    2018-03-01

    Knowledge of regional wave climates is critical for coastal planning, management, and protection. In order to develop a regional wave climate, it is important to understand the atmospheric systems responsible for wave generation. This study examines the variability of the southwest Western Australian (SWWA) shelf and nearshore wind wave climate and its relationship to southern hemisphere climate variability represented by various atmospheric indices: the southern oscillation index (SOI), the Southern Annular Mode (SAM), the Indian Ocean Dipole Mode Index (DMI), the Indian Ocean Subtropical Dipole (IOSD), the latitudinal position of the subtropical high-pressure ridge (STRP), and the corresponding intensity of the subtropical ridge (STRI). A 21-year wave hindcast (1994-2014) of the SWWA continental shelf was created using the third generation wave model Simulating WAves Nearshore (SWAN), to analyse the seasonal and inter-annual wave climate variability and its relationship to the atmospheric regime. Strong relationships between wave heights and the STRP and the STRI, a moderate correlation between the wave climate and the SAM, and no significant correlation between SOI, DMI, and IOSD and the wave climate were found. Strong spatial, seasonal, and inter-annual variability, as well as seasonal longer-term trends in the mean wave climate were studied and linked to the latitudinal changes in the subtropical high-pressure ridge and the Southern Ocean storm belt. As the Southern Ocean storm belt and the subtropical high-pressure ridge shifted southward (northward) wave heights on the SWWA shelf region decreased (increased). The wave height anomalies appear to be driven by the same atmospheric conditions that influence rainfall variability in SWWA.

  11. The height of the atmospheric boundary layer during unstable conditions

    Energy Technology Data Exchange (ETDEWEB)

    Gryning, S.E.

    2005-11-01

    The height of the convective atmospheric boundary layer, also called the mixed-layer, is one of the fundamental parameters that characterise the structure of the atmosphere near the ground. It has many theoretical and practical applications such as the prediction of air pollution concentrations, surface temperature and the scaling of turbulence. However, as pointed out by Builtjes (2001) in a review paper on Major Twentieth Century Milestones in Air Pollution Modelling and Its Application, the weakest point in meteorology data is still the determination of the height of the mixed-layer, the so-called mixing height. A simple applied model for the height of the mixed-layer over homogeneous terrain is suggested in chapter 2. It is based on a parameterised budget for the turbulent kinetic energy. In the model basically three terms - the spin-up term and the production of mechanical and convective turbulent kinetic energy - control the growth of the mixed layer. The interplay between the three terms is related to the meteorological conditions and the height of the mixed layer. A stable layer, the so-called entrainment zone, which is confined between the mixed layer and the free air above, caps the mixed layer. A parameterisation of the depth of the entrainment zone is also suggested, and used to devise a combined model for the height of the mixed layer and the entrainment zone. Another important aspect of the mixed layer development exists in coastal areas where an internal boundary layer forms downwind from the coastline. A model for the growth of the internal boundary layer is developed in analogy with the model for mixed layer development over homogeneous terrain. The strength of this model is that it can operate on a very fine spatial resolution with minor computer resources. Chapter 3 deals with the validation of the models. It is based in parts on data from the literature, and on own measurements. For the validation of the formation of the internal boundary layer

  12. Wave Dissipation on Low- to Super-Energy Coral Reefs

    Science.gov (United States)

    Harris, D. L.

    2016-02-01

    Coral reefs are valuable, complex and bio-diverse ecosystems and are also known to be one of the most effective barriers to swell events in coastal environments. Previous research has found coral reefs to be remarkably efficient in removing most of the wave energy during the initial breaking and transformation on the reef flats. The rate of dissipation is so rapid that coral reefs have been referred to as rougher than any known coastal barrier. The dissipation of wave energy across reef flats is crucial in maintaining the relatively low-energy conditions in the back reef and lagoonal environments providing vital protection to adjacent beach or coastal regions from cyclone and storm events. A shift in the regulation of wave energy by reef flats could have catastrophic consequences ecologically, socially, and economically. This study examined the dissipation of wave energy during two swell events in Tahiti and Moorea, French Polyesia. Field sites were chosen in varying degrees of exposure and geomorphology from low-energy protected sites (Tiahura, Moorea) to super-energy sites (Teahupo'o, Tahiti). Waves were measured during two moderate to large swell events in cross reef transects using short-term high-resolution pressure transducers. Wave conditions were found to be similar in all back reef locations despite the very different wave exposure at each reef site. However, wave conditions on the reef flats were different and mirrored the variation in wave exposure with depth over the reef flat the primary regulator of reef flat wave height. These results indicate that coral reef flats evolve morphodynamically with the wave climate, which creates coral reef geomorphologies capable of dissipating wave energy that results in similar back reef wave conditions regardless of the offshore wave climate.

  13. Waves in Saturn's rings probed by radio occultation

    International Nuclear Information System (INIS)

    Rosen, P.A.

    1989-01-01

    Thirty wave features, observed in 3.6 and 13 cm-wavelength optical depth profiles of Saturn's rings obtained by Voyager 1 radio occultation, are analyzed individually and comparatively. Many are the signature of spiral density waves and bending waves excited by gravitational resonances with Saturn's satellites. A new technique for locating waveform extrema, which fits a sinusoid to each half cycle of wave data, quantifies the wavelength variation across a feature. Fitting dispersion models to the derived wavelengths provides new estimates of ambient surface mass density σ in each wave region. For fourteen weak density waves in Ring A, modelling of the waveform near resonance with linear density wave theory gives independent estimates of σ, as well as reliable estimates of resonance location. Measurements of wave amplitude damping give an upper bound for ring thickness 2H, where H is the ring scale height. In the wave regions studied, Rings A, B, and C have 30 approx-lt σ approx-lt 70, σ approx-gt 65, and σ ∼ 1 g/cm 2 , respectively. Mass loading estimates from waveform modelling are 20 to 40% larger than dispersion-derived values, suggesting accumulation of mass in the wave regions. The average offset of derived wave location from theoretical resonance is about 1 km. Model waveforms of overlapping waves excited by the satellites Janus and Epimethenus agree well with observed morphologies in the linear region near resonance. In Ring C, dispersion analysis indicates that the most prominent wave feature, previously unidentified, is a one-armed spiral wave

  14. Wave disc engine apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Muller, Norbert; Piechna, Janusz; Sun, Guangwei; Parraga, Pablo-Francisco

    2018-01-02

    A wave disc engine apparatus is provided. A further aspect employs a constricted nozzle in a wave rotor channel. A further aspect provides a sharp bend between an inlet and an outlet in a fluid pathway of a wave rotor, with the bend being spaced away from a peripheral edge of the wave rotor. A radial wave rotor for generating electricity in an automotive vehicle is disclosed in yet another aspect.

  15. Photon wave function

    OpenAIRE

    Bialynicki-Birula, Iwo

    2005-01-01

    Photon wave function is a controversial concept. Controversies stem from the fact that photon wave functions can not have all the properties of the Schroedinger wave functions of nonrelativistic wave mechanics. Insistence on those properties that, owing to peculiarities of photon dynamics, cannot be rendered, led some physicists to the extreme opinion that the photon wave function does not exist. I reject such a fundamentalist point of view in favor of a more pragmatic approach. In my view, t...

  16. Simulation and Optimization of Surface Acoustic Wave Devises

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard

    2007-01-01

    In this paper a method to model the interaction of the mechanical field from a surface acoustic wave and the optical field in the waveguides of a Mach-Zehnder interferometer is presented. The surface acoustic waves are generated by interdigital transducers using a plane strain model...... in effective refractive index introduced in the Mach-Zehnder interferometer arms by the stresses from the surface acoustic wave is calculated. It is shown that the effective refractive index of the fundamental optical mode increases at a surface acoustic wave crest and decreases at a trough. The height...... of a piezoelectric, inhomogeneous material and reflections from the boundaries are avoided by applying perfectly matched layers. The optical modes in the waveguides are modeled by the time-harmonic wave equation for the magnetic field. The two models are coupled using the stress-optical relation and the change...

  17. Traveling waves of the regularized short pulse equation

    International Nuclear Information System (INIS)

    Shen, Y; Horikis, T P; Kevrekidis, P G; Frantzeskakis, D J

    2014-01-01

    The properties of the so-called regularized short pulse equation (RSPE) are explored with a particular focus on the traveling wave solutions of this model. We theoretically analyze and numerically evolve two sets of such solutions. First, using a fixed point iteration scheme, we numerically integrate the equation to find solitary waves. It is found that these solutions are well approximated by a finite sum of hyperbolic secants powers. The dependence of the soliton's parameters (height, width, etc) to the parameters of the equation is also investigated. Second, by developing a multiple scale reduction of the RSPE to the nonlinear Schrödinger equation, we are able to construct (both standing and traveling) envelope wave breather type solutions of the former, based on the solitary wave structures of the latter. Both the regular and the breathing traveling wave solutions identified are found to be robust and should thus be amenable to observations in the form of few optical cycle pulses. (paper)

  18. Photoelectron wave function in photoionization: plane wave or Coulomb wave?

    Science.gov (United States)

    Gozem, Samer; Gunina, Anastasia O; Ichino, Takatoshi; Osborn, David L; Stanton, John F; Krylov, Anna I

    2015-11-19

    The calculation of absolute total cross sections requires accurate wave functions of the photoelectron and of the initial and final states of the system. The essential information contained in the latter two can be condensed into a Dyson orbital. We employ correlated Dyson orbitals and test approximate treatments of the photoelectron wave function, that is, plane and Coulomb waves, by comparing computed and experimental photoionization and photodetachment spectra. We find that in anions, a plane wave treatment of the photoelectron provides a good description of photodetachment spectra. For photoionization of neutral atoms or molecules with one heavy atom, the photoelectron wave function must be treated as a Coulomb wave to account for the interaction of the photoelectron with the +1 charge of the ionized core. For larger molecules, the best agreement with experiment is often achieved by using a Coulomb wave with a partial (effective) charge smaller than unity. This likely derives from the fact that the effective charge at the centroid of the Dyson orbital, which serves as the origin of the spherical wave expansion, is smaller than the total charge of a polyatomic cation. The results suggest that accurate molecular photoionization cross sections can be computed with a modified central potential model that accounts for the nonspherical charge distribution of the core by adjusting the charge in the center of the expansion.

  19. Assimilation of radar altimeter data in numerical wave models: an impact study in two different wave climate regions

    Directory of Open Access Journals (Sweden)

    G. Emmanouil

    2007-03-01

    Full Text Available An operational assimilation system incorporating significant wave height observations in high resolution numerical wave models is studied and evaluated. In particular, altimeter satellite data provided by the European Space Agency (ESA-ENVISAT are assimilated in the wave model WAM which operates in two different wave climate areas: the Mediterranean Sea and the Indian Ocean. The first is a wind-sea dominated area while in the second, swell is the principal part of the sea state, a fact that seriously affects the performance of the assimilation scheme. A detailed study of the different impact is presented and the resulting forecasts are evaluated against available buoy and satellite observations. The corresponding results show a considerable improvement in wave forecasting for the Indian Ocean while in the Mediterranean Sea the assimilation impact is restricted to isolated areas.

  20. Baldcypress Height-Diamter Equations and Their Prediction Confindence Intervals

    Science.gov (United States)

    Bernard R. Parresol

    1992-01-01

    Height-diameter relationships are an important component in yield estimation, stand description, and damage appraisals. A nonlinear exponential function used extensively in the northwest United States was chosen for bald cypress (Taxodium distichum (L.) Rich.). Homogeneity and normality of residuals were examined, and the function as well as the...

  1. Parturient symphysio-fundal height and abdominal girth ...

    African Journals Online (AJOL)

    Birth weight is known to influence morbidity and mortality. Simple measures to predict birth weight before delivery would therefore be useful in order to plan a delivery. Maternal parturient symphysio-fundal height has been used to detect Low Birth Weight. This study aims at predicting the fetal weight using the maternal ...

  2. Jump Shrug Height and Landing Forces Across Various Loads.

    Science.gov (United States)

    Suchomel, Timothy J; Taber, Christopher B; Wright, Glenn A

    2016-01-01

    The purpose of this study was to examine the effect that load has on the mechanics of the jump shrug. Fifteen track and field and club/intramural athletes (age 21.7 ± 1.3 y, height 180.9 ± 6.6 cm, body mass 84.7 ± 13.2 kg, 1-repetition-maximum (1RM) hang power clean 109.1 ± 17.2 kg) performed repetitions of the jump shrug at 30%, 45%, 65%, and 80% of their 1RM hang power clean. Jump height, peak landing force, and potential energy of the system at jump-shrug apex were compared between loads using a series of 1-way repeated-measures ANOVAs. Statistical differences in jump height (P .05). The greatest magnitudes of jump height, peak landing force, and potential energy of the system at the apex of the jump shrug occurred at 30% 1RM hang power clean and decreased as the external load increased from 45% to 80% 1RM hang power clean. Relationships between peak landing force and potential energy of the system at jump-shrug apex indicate that the landing forces produced during the jump shrug may be due to the landing strategy used by the athletes, especially at lighter loads. Practitioners may prescribe heavier loads during the jump-shrug exercise without viewing landing force as a potential limitation.

  3. The association between Helicobacter pylori infection and adult height

    International Nuclear Information System (INIS)

    Moayyedi, Paul; Forman, David; Duffett, Sara; Mason, Su; Brown, Julia; Crocombe, Will; Feltbower, Richard; Axon, Anthony

    2005-01-01

    Objectives: A cross-sectional survey was performed to evaluate the association between H. pylori and adult height. Methods: H. pylori infection was assessed using a 13 C-urea breath test and height measured by a research nurse using a stadiometer in participants between the ages of 40-49 years. Results: Height was measured in 2932/3682 participants that attended and were evaluable. H. pylori infected women were 1.4 cm shorter than uninfected women (95% confidence interval, CI=0.7-2.1 cm) and this statistically significant difference persisted after adjusting for age, ethnicity, childhood and present socio-economic status (H. pylori positives 0.79 cm shorter; 95%CI: 0.05-1.52 cm). H. pylori positive men were 0.7 cm shorter than uninfected men but this did not reach statistical significance (95% CI: -0.1-1.5 cm). Conclusion: Although H. pylori infection is associated with reduced adult height in women, this maybe due to residual confounding

  4. Estimates of forest canopy height and aboveground biomass using ICESat.

    Science.gov (United States)

    Michael A. Lefsky; David J. Harding; Michael Keller; Warren B. Cohen; Claudia C. Carabajal; Fernando Del Bom; Maria O. Hunter; Raimundo Jr. de Oliveira

    2005-01-01

    Exchange of carbon between forests and the atmosphere is a vital component of the global carbon cycle. Satellite laser altimetry has a unique capability for estimating forest canopy height, which has a direct and increasingly well understood relationship to aboveground carbon storage. While the Geoscience Laser Altimeter System (GLAS) onboard the Ice, Cloud and land...

  5. stem and standing heights in bantu and white south africans

    African Journals Online (AJOL)

    1971-05-29

    May 29, 1971 ... Sitting and standing heights have been recorded for Bantu and Whites, males and females. It !Vas found that Bantu males and females have relatively longer lower extremities than White South African males and females. Anthropo- metric differences account for only about 15% of the actual observed ...

  6. Tree height integrated into pantropical forest biomass estimates

    NARCIS (Netherlands)

    Feldpausch, T.R.; Lloyd, J.; Lewis, S.L.; Brienen, R.J.W.; Gloor, M.; Montegudo Mendoza, A.; Arets, E.J.M.M.

    2012-01-01

    Aboveground tropical tree biomass and carbon storage estimates commonly ignore tree height (H). We estimate the effect of incorporating H on tropics-wide forest biomass estimates in 327 plots across four continents using 42 656 H and diameter measurements and harvested trees from 20 sites to answer

  7. The Effects of Microgravity on Seated Height (Spinal Elongation)

    Science.gov (United States)

    Young, K. S.; Rajulu, S.

    2011-01-01

    ABSTRACT Many physiological factors, such as spinal elongation, fluid shifts, bone atrophy, and muscle loss, occur during an exposure to a microgravity environment. Spinal elongation is just one of the factors that can also affect the safety and performance of a crewmember while in space. Spinal elongation occurs due to the lack of gravity/compression on the spinal column. This allows for the straightening of the natural spinal curve. There is a possible fluid shift in the inter-vertebral disks that may also result in changes in height. This study aims at collecting the overall change in seated height for crewmembers exposed to a microgravity environment. During previous Programs, Apollo-Soyuz Test Project (ASTP) and Skylab, spinal elongation data was collected from a small number of subjects in a standing posture but were limited in scope. Data from these studies indicated a quick increase in stature during the first few days of weightlessness, after which stature growth reached a plateau resulting in up to a 3% increase of the original measurement [1-5]. However, this data was collected only for crewmembers in standing posture and not in a seated posture. Seated height may have a different effect than standing height due to a change in posture as well as due to a compounded effect of wearing restraints and a potential compression of the gluteal area. Seated height was deemed as a critical measurement in the design of the Constellation Program s (CxP) Crew Exploration Vehicle (CEV), called Orion which is now the point-of-departure vehicle for the Multi-Purpose Crew Vehicle (MPCV) Program; therefore a better understanding of the effects of microgravity on seated height is necessary. Potential changes in seated height that may not have impacted crew accommodation in previous Programs will have significant effects on crew accommodation due to the layout of seats in the Orion.. The current and existing configuration is such that the four crewmembers are stacked two by

  8. Output pulse height distribution of the GM counters

    International Nuclear Information System (INIS)

    Zhang Songshou; Xiong Jianping

    1995-01-01

    The GM counters are the radiation detectors most in use. It has special advantages compared with other detectors. This paper introduces the output pulse height distribution of the GM counters, gives the measuring instruments and methods. The measuring results, some discussions, and useful conclusion are given as well

  9. 76 FR 77696 - Establishment of the Naches Heights Viticultural Area

    Science.gov (United States)

    2011-12-14

    ... Decision. SUMMARY: This final rule establishes the 13,254-acre ``Naches Heights'' viticultural area in... origin of their wines and to allow consumers to better identify wines they may purchase. DATES: Effective... consumers to identify wines they may purchase. Establishment of a viticultural area is neither an approval...

  10. Intrapartum symphysio-fundal height measurement as a predictor of ...

    African Journals Online (AJOL)

    Background: Low birth weight (LBW) increases the risk of perinatal morbidity and mortality and of the long term neurologic and developmental disorders. Early identification of LBW is necessary to decrease complications and enhance the survival of the newborn. Aim: To determine the usefulness of symphysio-fundal height ...

  11. Many sequence variants affecting diversity of adult human height

    DEFF Research Database (Denmark)

    Gudbjartsson, Daniel F; Walters, G Bragi; Thorleifsson, Gudmar

    2008-01-01

    .3 and 0.6 cm and, taken together, they explain around 3.7% of the population variation in height. The genes neighboring the identified loci cluster in biological processes related to skeletal development and mitosis. Association to three previously reported loci are replicated in our analyses...

  12. Assortative mating for human height : A meta-analysis

    NARCIS (Netherlands)

    Stulp, Gert; Simons, Mirre J. P.; Grasman, Sara; Pollet, Thomas V.

    ObjectivesThe study of assortative mating for height has a rich history in human biology. Although the positive correlation between the stature of spouses has often been noted in western populations, recent papers suggest that mating patterns for stature are not universal. The objective of this

  13. Individual tree diameter, height, and volume functions for longleaf pine

    Science.gov (United States)

    Carlos A. Gonzalez-Benecke; Salvador A. Gezan; Timothy A. Martin; Wendell P. Cropper; Lisa J. Samuelson; Daniel J. Leduc

    2014-01-01

    Currently, little information is available to estimate individual tree attributes for longleaf pine (Pinus palustris Mill.), an important tree species of the southeastern United States. The majority of available models are local, relying on stem diameter outside bark at breast height (dbh, cm) and not including stand-level parameters. We developed...

  14. SYMMETRICAL (AND GENERIC) ALGORITHMS FOR HEIGHT BALANCED TREES

    NARCIS (Netherlands)

    BRON, C

    1990-01-01

    Most algorithms for height balanced trees (or AVL-trees, after Adelson-Velskii and Landis [1]) suffer from a lack of exploitation of the symmetry of balance restoring operations when insertions and deletions in such tree structures are being made. Either we find algorithms in duplicate (i.e.,

  15. Tree height-diameter allometry across the United States.

    Science.gov (United States)

    Hulshof, Catherine M; Swenson, Nathan G; Weiser, Michael D

    2015-03-01

    The relationship between tree height and diameter is fundamental in determining community and ecosystem structure as well as estimates of biomass and carbon storage. Yet our understanding of how tree allometry relates to climate and whole organismal function is limited. We used the Forest Inventory and Analysis National Program database to determine height-diameter allometries of 2,976,937 individuals of 293 tree species across the United States. The shape of the allometric relationship was determined by comparing linear and nonlinear functional forms. Mixed-effects models were used to test for allometric differences due to climate and floristic (between angiosperms and gymnosperms) and functional groups (leaf habit and shade tolerance). Tree allometry significantly differed across the United States largely because of climate. Temperature, and to some extent precipitation, in part explained tree allometric variation. The magnitude of allometric variation due to climate, however, had a phylogenetic signal. Specifically, angiosperm allometry was more sensitive to differences in temperature compared to gymnosperms. Most notably, angiosperm height was more negatively influenced by increasing temperature variability, whereas gymnosperm height was negatively influenced by decreasing precipitation and increasing altitude. There was little evidence to suggest that shade tolerance influenced tree allometry except for very shade-intolerant trees which were taller for any given diameter. Tree allometry is plastic rather than fixed and scaling parameters vary around predicted central tendencies. This allometric variation provides insight into life-history strategies, phylogenetic history, and environmental limitations at biogeographical scales.

  16. Predicting human height by Victorian and genomic methods

    NARCIS (Netherlands)

    Y.S. Aulchenko (Yurii); M.V. Struchalin (Maksim); N.M. Belonogova (Nadezhda); T.I. Axenovich (Tatiana); M.N. Weedon (Michael); A. Hofman (Albert); A.G. Uitterlinden (André); M.H. Kayser (Manfred); B.A. Oostra (Ben); P. Tikka-Kleemola (Päivi); A.C.J.W. Janssens (Cécile); P.M. Borodin (Pavel)

    2009-01-01

    textabstractIn the Victorian era, Sir Francis Galton showed that 'when dealing with the transmission of stature from parents to children, the average height of the two parents, ... is all we need care to know about them' (1886). One hundred and twenty-two years after Galton's work was published, 54

  17. Height suppression of tomato plug seedlings by an environment ...

    African Journals Online (AJOL)

    Experiments were conducted to investigate appropriate concentrations of plant growth retardants (PGRs) and duration of seed soaking in order to suppress hypocotyl length and plug seedling height of 2 tomato cultivars ( Lycopersicum esculentum Mill. cv. Seogeon and Seokwang). Daminozide (B-9), uniconazole ...

  18. Nest height of the red bishop ( Eupiectes orix ) | Woodall | African ...

    African Journals Online (AJOL)

    Heights of nests and reeds in a colony of red bishops (Euplectes orix) in Phragmites mauritianus reeds on the Makabusi River, Zimbabwe were measured in two breeding seasons. Nests were placed high in the reeds with fewer above the mean and more below the mean than in a normal distribution. During the course of a ...

  19. The role of height in the sex difference in intelligence.

    Science.gov (United States)

    Kanazawa, Satoshi; Reyniers, Diane J

    2009-01-01

    Recent studies conclude that men on average have higher intelligence than women by 3-5 IQ points. However, the ultimate evolutionary question of why men should have evolved to have higher intelligence than women remains. We suggest that men may have slightly higher intelligence than women through 4 mechanisms: (1) assortative mating of intelligent men and beautiful women, (2) assortative mating of tall men and beautiful women, (3) an extrinsic correlation between height and intelligence produced by Mechanisms 1 and 2, and (4) a higher-than-expected offspring sex ratio (more sons) among tall (and hence intelligent) parents. Consistent with our suggestion, we show that men may have higher IQs than women because they are taller, and once we control for height women have slightly higher IQs than men.The correlation between height and IQ and the female advantage in intelligence persist even after we control for health as a measure of genetic quality, as well as physical attractiveness, age, race, education, and earnings. Height is also strongly associated with intelligence within each sex.

  20. Inheritance of culm height and grain yield in durum wheat

    International Nuclear Information System (INIS)

    Filev, K.

    1984-01-01

    Results from a study of GA sensitive and GA insensitive durum wheat mutants and cultivars in relation with their culm height and 1000 grain weight are presented. With increasing culm height, the GA response also increased. A positive correlation between plant height and GA response was found. Crosses were made between durum wheats and the F 1 and F 2 progenies were analysed. A different inheritance in F 1 and segregation in F 2 was obtained in crosses of a semi-dwarf, GA insensitive [1] line with GA sensitive (S) lines differing in height, medium (93.2cm) and tall (133.5cm). In a reciprocal cross, semi-dwarf - I with medium - S, the semi-dwarf type was dominant in F 1 , suggesting that their semi-dwarfing genes were not allelic. When the semi-dwarf - I and tall - S were crossed an intermediate inheritance in F 1 was observed. In the F 2 generation from crosses semi-dwarf - I with medium - S with semi-dwarf - I, a phenotypic dihybred segregation 9:3:3:1 was observed. In crosses semi-dwarf - I with tall - S different variation curves were obtained. Semi-dwarfs with high productivity were observed in F 2 , a fact indicating that lodging resistant lines with high yields could be selected. (author)