WorldWideScience

Sample records for surface heights derived

  1. Derivation of Orthometric Heights from GPS Measured Heights ...

    African Journals Online (AJOL)

    In this study, geometric technique of deriving orthometric height from GPS survey along a profile and the use of EGM 96 geoid model for deriving orthometric height from GPS data (using GNSS solution software) are discussed. The main focus of the research is to critically examine the potentials of these methods with a view ...

  2. The Algorithm Theoretical Basis Document for the Derivation of Range and Range Distributions from Laser Pulse Waveform Analysis for Surface Elevations, Roughness, Slope, and Vegetation Heights

    Science.gov (United States)

    Brenner, Anita C.; Zwally, H. Jay; Bentley, Charles R.; Csatho, Bea M.; Harding, David J.; Hofton, Michelle A.; Minster, Jean-Bernard; Roberts, LeeAnne; Saba, Jack L.; Thomas, Robert H.; hide

    2012-01-01

    The primary purpose of the GLAS instrument is to detect ice elevation changes over time which are used to derive changes in ice volume. Other objectives include measuring sea ice freeboard, ocean and land surface elevation, surface roughness, and canopy heights over land. This Algorithm Theoretical Basis Document (ATBD) describes the theory and implementation behind the algorithms used to produce the level 1B products for waveform parameters and global elevation and the level 2 products that are specific to ice sheet, sea ice, land, and ocean elevations respectively. These output products, are defined in detail along with the associated quality, and the constraints, and assumptions used to derive them.

  3. 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...

  4. 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)

  5. 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.

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

    Science.gov (United States)

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

    2017-12-01

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

  7. A 3-point derivation of dominant tree height equations

    Science.gov (United States)

    Don C. Bragg

    2011-01-01

    This paper describes a new approach for deriving height-diameter (H-D) equations from limited information and a few assumptions about tree height. Only three data points are required to fit this model, which can be based on virtually any nonlinear function. These points are the height of a tree at diameter at breast height (d.b.h.), the predicted height of a 10-inch d....

  8. CALIOP-derived Smoke Plume Injection Height

    Science.gov (United States)

    Soja, A. J.; Winker, D. M.; Choi, H. D.; Fairlie, T. D.; Westberg, D. J.; Roller, C. M.; Pouliot, G.; Vaughan, M.; Pierce, T. E.; Trepte, C. R.; Rao, V.

    2014-12-01

    Biomass burning is a dominant natural and anthropogenic disturbance that feeds back to the climate system. Fire regimes, ecosystem fuels, fire severity and intensity vary widely, even within the same system, largely under the control of weather and climate. These strongly influence fire plume injection height and thus the transport of related biomass burning emissions, affecting air quality, human health and the climate system. If our knowledge of plume injection height is incorrect, transport models of those emissions will likewise be incorrect, adversely affecting our ability to analyze and predict climate feedbacks (i.e. black carbon to the Arctic, precipitation, cloud-radiation relationships) and public health (air quality forecast). Historically, plume height was based on the pioneering work of G.A. Briggs [1969; 1971] and verified with limited field campaigns. However, we currently have two satellite instruments, Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) onboard CALIPSO (afternoon overpass) and Multi-angle Imaging SpectroRadiometer (MISR) onboard TERRA (morning overpass), that can provide the statistics necessary to verify our assumptions and improve fire plume injection height estimates for use in both small- and large-scale models. We have developed a methodology to assess fire plume injection height using the Langley Trajectory Model (LaTM), CALIOP, Hazard Mapping System (HMS) smoke plume, and MODerate Resolution Imaging Spectrometer (MODIS) thermal anomaly data that is capable of generating two distinct types of verification data. A single CALIOP smoke-filled aerosol envelop can be traced back to numerous fire events, and using multiple CALIOP transects from numerous days, a daily smoke plume injection height evolution from a single fire can be defined. Additionally, we have linked the smoke plumes to ecosystems and the meteorological variables that define fire weather. In concert, CALIOP and MISR data can produce the statistical knowledge

  9. Boundary layer heights and surface fluxes of momentum and heat derived from ECMWF data for use in pollutant dispersion models - problems with data accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Wotawa, G. [Univ. of Agricultural Sciences, Inst. of Meteorology and Physics, Vienna (Austria); Stohl, A. [Ludwig-Maximilians-Univ. Muenchen, Munich (Germany)

    1997-10-01

    Certain boundary layer parameters, especially boundary layer heights, are very important for pollutant dispersion modelling. On the regional scale (>- 100 km), data of the numerical weather prediction model of the European Centre for Medium-Range Weather Forecasts are often used for that purpose. Based on ECMWF data, the meteorological preprocessor FLEXTRA for Lagrangian air quality simulation models and the Lagrangian particle diffusion model FLEXPART have been developed. Using analyses and short term forecasts, a temporal resolution of three hours can be achieved. Some alternative methods to obtain boundary layer parameters can be applied, producing different results which affect all subsequent calculations, for instance the calculation of boundary layer trajectories and the dispersion of air pollutants. (au)

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

    Digital Repository Service at National Institute of Oceanography (India)

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

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

  11. Optical triangulation method for height measurements on water surfaces

    Science.gov (United States)

    Maas, Hans-Gerd; Hentschel, Bernd; Schreiber, Frank

    2003-01-01

    Optical triangulation methods based on a laser light sheet and a camera are frequently used as a surface measurement technique in a wide range of applications. They allow for the fast accurate determination of height profiles, based on relatively simple hardware and software configurations. Moreover, they can be implemented very efficiently and are especially suited for measurements on moving objects such as products on an assembly line. The study presented in the paper describes the adaptation of laser light sheet optical triangulation techniques to the task of water level profile measurements in hydromechanics experimental facilities. The properties of water surfaces necessitate several modifications of optical triangulation techniques to make them applicable: The mirror-like reflection properties of water surfaces form a contradiction to the assumption of diffuse reflection, on which standard light sheet triangulation techniques are based; this problem can be circumvented by using a diffuse reflecting projection plane to capture the mirror-like reflection of the laser line from the water surface. Due to the angle of incidence law, however, water surface tilts caused by waves will usually cause a strong degradation of the quality of the results when using reflected light; this effect can largely be compensated by processing max-store images derived from short image sequences rather than single images. These extensions of optical triangulation turned out to be crucial for the applicability of the method on water surfaces. Besides the theoretical concept and a sensitivity analysis of the method, a system configuration is outlined, and the results of a number of practical experiments are shown and discussed.

  12. Height, surface firmness, and visual reference effects on balance control.

    Science.gov (United States)

    Simeonov, P; Hsiao, H

    2001-09-01

    To investigate the effects of height, surface firmness, and visual reference on standing balance in construction workers. Controlled laboratory study with balanced repeated measures. Twenty four construction workers. Test subjects performed standing tasks at ground level as well as at 3 m and 9 m high balconies on firm or deformable surfaces with close visual references included or excluded from their visual field. Standing balance was determined from center of pressure as measured by a force platform. Dependent variables were root mean square of sway in medial-lateral and anterior-posterior directions, area of sway, and velocity of sway. Heights without close visual references significantly increased all sway parameters. The effect of height in conditions without close visual references increased dramatically on deformable surfaces. Elevated work environments and deformable work surfaces negatively affect balance and may be associated with increased risk of fall incidents. Appropriate close visual references increase the ability to maintain balance.

  13. Interferometric Surface Relief Measurements with Subnano/Picometer Height Resolution

    Science.gov (United States)

    Sysoev, Evgeny; Kosolobov, Sergey; Kulikov, Rodion; Latyshev, Alexander; Sitnikov, Sergey; Vykhristyuk, Ignat

    2017-10-01

    We present an optical interference system nanoprofiler MNP-1 designed for high-precision noncontact measurement of surface relief with subnanometer resolution (root mean square of measured values), based on partial scanning of interference signal. The paper describes the construction of the measurement system with Linnik interferometer and the algorithm for nanorelief surface reconstruction. Experimental measurement results of silicon sample with profile height of surface structure of one interatomic distance obtained by MNP-1 are shown. It was proposed to use an atomically smooth surface as the reference mirror in the interferometer MNP-1 that allowed us to measure monatomic steps of the presented silicon sample. Monatomic steps of 0.31 nm in height on silicon (111) surface were measured with resolution up to 5 pm.

  14. Derivation of pulse height to exposure rate conversion functions for aerial radiological surveys

    International Nuclear Information System (INIS)

    Artuso, J.F.

    1985-01-01

    A method is described for deriving conversion functions that can be used to convert pulse height spectra taken at altitude to the exposure rate at the 1-m level. An integral equation is set up which involves the integration of a calculated pulse height spectrum multiplied by an unknown conversion function and then set equal to the exposure rate at ground level. This equation is then solved for the conversion function by assuming as a solution a three-term polynomial. Conversion functions have been derived for various source distributions, including surface, uniform, and exponentially distributed sources. These conversion functions are independent of source energy, which means that a conversion can be made without any knowledge of the isotopic content of the source. In the case of a uniform distribution, these conversion functions provide conversions that agree to within 10% with ground truth measurements

  15. 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.

  16. Validation of mixing heights derived from the operational NWP models at the German weather service

    Energy Technology Data Exchange (ETDEWEB)

    Fay, B.; Schrodin, R.; Jacobsen, I. [Deutscher Wetterdienst, Offenbach (Germany); Engelbart, D. [Deutscher Wetterdienst, Meteorol. Observ. Lindenberg (Germany)

    1997-10-01

    NWP models incorporate an ever-increasing number of observations via four-dimensional data assimilation and are capable of providing comprehensive information about the atmosphere both in space and time. They describe not only near surface parameters but also the vertical structure of the atmosphere. They operate daily, are well verified and successfully used as meteorological pre-processors in large-scale dispersion modelling. Applications like ozone forecasts, emission or power plant control calculations require highly resolved, reliable, and routine values of the temporal evolution of the mixing height (MH) which is a critical parameter in determining the mixing and transformation of substances and the resulting pollution levels near the ground. The purpose of development at the German Weather Service is a straightforward mixing height scheme that uses only parameters derived from NWP model variables and thus automatically provides spatial and temporal fields of mixing heights on an operational basis. An universal parameter to describe stability is the Richardson number Ri. Compared to the usual diagnostic or rate equations, the Ri number concept of determining mixing heights has the advantage of using not only surface layer parameters but also regarding the vertical structure of the boundary layer resolved in the NWP models. (au)

  17. Comments on deriving the equilibrium height of the stable boundary layer

    NARCIS (Netherlands)

    Steeneveld, G.J.; Wiel, van de B.J.H.; Holtslag, A.A.M.

    2007-01-01

    Recently, the equilibrium height of the stable boundary layer received much attention in a series of papers by Zilitinkevich and co-workers. In these studies the stable boundary-layer height is derived in terms of inverse interpolation of different boundary-layer height scales, each representing a

  18. 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

  19. 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

  20. Linear predictability: A sea surface height case study

    Science.gov (United States)

    Sonnewald, Maike; Wunsch, Carl; Heimbach, Patrick

    2017-04-01

    A benchmark of linear predictive skill of global sea surface height (SSH or η) is presented, complementing more complicated studies of η predictive skill. Twenty years of the ECCOv4 state estimate (1992-2012) are used, fitting ARMA(n,m) models where the order is chosen by the Akaike and Bayesian Information Criteria (AIC and BIC). The prediction on the basis of monthly detrended data shows skill generally of the order of a few months, with isolated regions of twelve months or more. With the trend, the predictive skill increases, particularly in the south Pacific. Annually averaged data are also used, although the time-series are too short to assess the variability. Including a linear trend as part of the signal results in some enhanced predictability.

  1. Relationship between LiDAR-derived forest canopy height and Landsat images

    Science.gov (United States)

    Cristina Pascual; Antonio Garcia-Abril; Warren B. Cohen; Susana. Martin-Fernandez

    2010-01-01

    The mean and standard deviation (SD) of light detection and ranging (LiDAR)-derived canopy height are related to forest structure. However, LiDAR data typically cover a limited area and have a high economic cost compared with satellite optical imagery. Optical images may be required to extrapolate LiDAR height measurements across a broad landscape. Different spectral...

  2. Direct derivation of maize plant and crop height from low-cost time-of-flight camera measurements.

    Science.gov (United States)

    Hämmerle, Martin; Höfle, Bernhard

    2016-01-01

    In agriculture, information about the spatial distribution of crop height is valuable for applications such as biomass and yield estimation, or increasing field work efficiency in terms of fertilizing, applying pesticides, irrigation, etc. Established methods for capturing crop height often comprise restrictions in terms of cost and time efficiency, flexibility, and temporal and spatial resolution of measurements. Furthermore, crop height is mostly derived from a measurement of the bare terrain prior to plant growth and measurements of the crop surface when plants are growing, resulting in the need of multiple field campaigns. In our study, we examine a method to derive crop heights directly from data of a plot of full grown maize plants captured in a single field campaign. We assess continuous raster crop height models (CHMs) and individual plant heights derived from data collected with the low-cost 3D camera Microsoft ® Kinect ® for Xbox One™ based on a comprehensive comparison to terrestrial laser scanning (TLS) reference data. We examine single measurements captured with the 3D camera and a combination of the single measurements, i.e. a combination of multiple perspectives. The quality of both CHMs, and individual plant heights is improved by combining the measurements. R 2 of CHMs derived from single measurements range from 0.48 to 0.88, combining all measurements leads to an R 2 of 0.89. In case of individual plant heights, an R 2 of 0.98 is achieved for the combined measures (with R 2  = 0.44 for the single measurements). The crop heights derived from the 3D camera measurements comprise an average underestimation of 0.06 m compared to TLS reference values. We recommend the combination of multiple low-cost 3D camera measurements, removal of measurement artefacts, and the inclusion of correction functions to improve the quality of crop height measurements. Operating low-cost 3D cameras under field conditions on agricultural machines or on autonomous

  3. CMS: LiDAR-derived Canopy Height, Elevation for Sites in Kalimantan, Indonesia, 2014

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset provides canopy height and elevation data products derived from airborne LiDAR data collected over 90 sites on the island of Borneo in late 2014. The...

  4. CMS: GLAS LiDAR-derived Global Estimates of Forest Canopy Height, 2004-2008

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides estimates of forest canopy height derived from the Geoscience Laser Altimeter System (GLAS) LiDAR instrument that was aboard the NASA Ice,...

  5. OSGM02: A new model for converting GPS-derived heights to local height datums in Great Britain and Ireland

    DEFF Research Database (Denmark)

    Iliffe, J.C.; Ziebart, M.; Cross, P.A.

    2003-01-01

    The background to the recent computation of a new vertical datum model for the British Isles (OSGM02) is described After giving a brief description of the computational techniques and the data sets used for the derivation of the gravimetric geoid, the paper focuses on the fitting of this surface...

  6. OSGM02: A new model for converting GPS-derived heights to local height datums in Great Britain and Ireland

    DEFF Research Database (Denmark)

    Iliffe, J.C.; Ziebart, M.; Cross, P.A.

    2003-01-01

    The background to the recent computation of a new vertical datum model for the British Isles (OSGM02) is described After giving a brief description of the computational techniques and the data sets used for the derivation of the gravimetric geoid, the paper focuses on the fitting of this surface ...... procedure. Results for each major region (Great Britain, Ireland, and Northern Ireland) as well as the various independent island datums are described The problems to be expected when working between datums are discussed....

  7. 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...

  8. Automated lidar-derived canopy height estimates for the Upper Mississippi River System

    Science.gov (United States)

    Hlavacek, Enrika

    2015-01-01

    Land cover/land use (LCU) classifications serve as important decision support products for researchers and land managers. The LCU classifications produced by the U.S. Geological Survey’s Upper Midwest Environmental Sciences Center (UMESC) include canopy height estimates that are assigned through manual aerial photography interpretation techniques. In an effort to improve upon these techniques, this project investigated the use of high-density lidar data for the Upper Mississippi River System to determine canopy height. An ArcGIS tool was developed to automatically derive height modifier information based on the extent of land cover features for forest classes. The measurement of canopy height included a calculation of the average height from lidar point cloud data as well as the inclusion of a local maximum filter to identify individual tree canopies. Results were compared to original manually interpreted height modifiers and to field survey data from U.S. Forest Service Forest Inventory and Analysis plots. This project demonstrated the effectiveness of utilizing lidar data to more efficiently assign height modifier attributes to LCU classifications produced by the UMESC.

  9. The climatology of planetary boundary layer height in China derived from radiosonde and reanalysis data

    Directory of Open Access Journals (Sweden)

    J. Guo

    2016-10-01

    Full Text Available The important roles of the planetary boundary layer (PBL in climate, weather and air quality have long been recognized, but little is known about the PBL climatology in China. Using the fine-resolution sounding observations made across China and reanalysis data, we conducted a comprehensive investigation of the PBL in China from January 2011 to July 2015. The boundary layer height (BLH is found to be generally higher in spring and summer than that in fall and winter. The comparison of seasonally averaged BLHs derived from observations and reanalysis, on average, shows good agreement, despite the pronounced inconsistence in some regions. The BLH, derived from soundings conducted three or four times daily in summer, tends to peak in the early afternoon, and the diurnal amplitude of BLH is higher in the northern and western subregions of China than other subregions. The meteorological influence on the annual cycle of BLH is investigated as well, showing that BLH at most sounding sites is negatively associated with the surface pressure and lower tropospheric stability, but positively associated with the near-surface wind speed and temperature. In addition, cloud tends to suppress the development of PBL, particularly in the early afternoon. This indicates that meteorology plays a significant role in the PBL processes. Overall, the key findings obtained from this study lay a solid foundation for us to gain a deep insight into the fundamentals of PBL in China, which helps to understand the roles that the PBL plays in the air pollution, weather and climate of China.

  10. A Study on the Relationships among Surface Variables to Adjust the Height of Surface Temperature for Data Assimilation.

    Science.gov (United States)

    Kang, J. H.; Song, H. J.; Han, H. J.; Ha, J. H.

    2016-12-01

    The observation processing system, KPOP (KIAPS - Korea Institute of Atmospheric Prediction Systems - Package for Observation Processing) have developed to provide optimal observations to the data assimilation system for the KIAPS Integrated Model (KIM). Currently, the KPOP has capable of processing almost all of observations for the KMA (Korea Meteorological Administration) operational global data assimilation system. The height adjustment of SURFACE observations are essential for the quality control due to the difference in height between observation station and model topography. For the SURFACE observation, it is usual to adjust the height using lapse rate or hypsometric equation, which decides values mainly depending on the difference of height. We have a question of whether the height can be properly adjusted following to the linear or exponential relationship solely with regard to the difference of height, with disregard the atmospheric conditions. In this study, firstly we analyse the change of surface variables such as temperature (T2m), pressure (Psfc), humidity (RH2m and Q2m), and wind components (U and V) according to the height difference. Additionally, we look further into the relationships among surface variables . The difference of pressure shows a strong linear relationship with difference of height. But the difference of temperature according to the height shows a significant correlation with difference of relative humidity than with the height difference. A development of reliable model for the height-adjustment of surface temperature is being undertaken based on the preliminary results.

  11. Derived limits for surface contamination

    CERN Document Server

    Wrixon, A D; Linsley, G S; White, D F

    1979-01-01

    Derived limits (DLs) for surface contamination were first established for use in the nuclear energy industry where a wide variety of radionuclides is encountered. They were later used in factories, hospitals, and universities, where the radionuclides used are normally fewer in number, either known or readily identifiable, and often of low toxicity. In these situations the current limits are frequently over-restrictive. This report describes a reassessment of the values in the light of more recent information on the possible pathways of exposure and the dose equivalent limits given in ICRP Publication 26. The reassessment is prompted also by the introduction of SI units. The results of the reassessment are used to produce a classification of DLs for all radionuclides for active and inactive area surfaces and for skin.

  12. A Method for Deriving the Boundary Layer Mixing Height from MODIS Atmospheric Profile Data

    Directory of Open Access Journals (Sweden)

    Xueliang Feng

    2015-09-01

    Full Text Available The planetary boundary layer is the medium of energy, moisture, momentum and pollutant exchange between the surface and the atmosphere. In this paper, a method to derive the boundary layer mixing height (MH was introduced and applied over the Heihe river basin. Atmospheric profiles from the MODerate Resolution Imaging Sepctroradiometer (MODIS instrument onboard the NASA-Aqua satellite were used for the high spatial resolution of this method. A gap-filling method was used to replace missing MODIS data. In situ MH data were also calculated from HIWATER (Heihe Watershed Allied Telemetry Experimental Research and WATER (Watershed Allied Telemetry Experimental Research observational radiosonde sounding data from 2008 and 2012 using the Richardson number method combined with a subjective method. The MH occurs where there is an abrupt decrease in the MR (water vapor mixing ratio. The minimum vertical gradient of the MR is used to determine the MH. The method has an average RMSE of 370 m under clear skies and convective conditions. The seasonal variation in the MH at the Gaoya radiosonde station is also presented. The study demonstrates that remote sensing methodologies can successfully estimate the MH without the help of field measurements.

  13. 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.

    significant wave height and brightness temperature at 19 and 22 GHz, and multiple correlation at 19 and 22 GHz are studied. Significant wave height derived from the linear regression at 19 GHz as well as from multiple regression at 19 and 22 GHz, yields better...

  14. Mixing layer heights derived from ceilometers: Useful for air quality studies?

    Science.gov (United States)

    Wiegner, Matthias; Geiß, Alexander; Schäfer, Klaus; Forkel, Renate; Chan, Ka Lok; Münkel, Christoph; von Schneidemesser, Erika; Gerwig, Holger; Nothard, Rainer; Bonn, Boris

    2017-04-01

    Ceilometers have been used for several meteorological applications, often in the framework of air quality studies. Whereas the particle backscatter coefficient can be retrieved in a quantitative way only recently (with the improvements of the hardware, Wiegner et al., 2014), mixing layer heights (MLH) have been derived for more than two decades. Several approaches are documented in the literature, however, automated procedures are still prone to errors because of difficulties in the recognition and attribution of discontinuities ("steps") in the backscatter profiles. For example, it is often not clear whether a detected change in the vertical distribution of aerosol backscatter indicates the residual layer, the stable boundary layer, or an elevated layer. Thus, an assessment of the reliability and accuracy of MLH-retrievals is relevant for air quality studies: on the one hand MLHs are often inversely correlated with ground-based in-situ measurements of particulate matter and gaseous pollutant concentrations, and on the other hand, MLH-retrievals can be used to validate chemistry transport models. To understand the benefit of MLH in the context of air quality, we have compared several retrievals of the MLH from ceilometer measurements during a field-campaign in summer 2014 (Bonn et al., 2016) for background and polluted sites in Berlin. Correlations between the concentrations of several pollutants and MLH are analyzed, and how they are influenced by the uncertainty of the derived MLH. References: Bonn, B. et al.: BAERLIN2014 - the influence of land surface types on and the horizontal heterogeneity of air pollutant levels in Berlin, Atmos. Chem. Phys., 16, 7785-7811, doi:10.5194/acp-16-7785-2016, 2016. Wiegner, M. et al. (2014): What is the benefit of ceilometers for aerosol remote sensing? An answer from EARLINET, Atmos. Meas. Tech., 7, 1979-1997, doi:10.5194/amt-7-1979-2014, 2014.

  15. Parametric fitting of corneal height data to a biconic surface.

    Science.gov (United States)

    Janunts, Edgar; Kannengießer, Marc; Langenbucher, Achim

    2015-03-01

    As the average corneal shape can effectively be approximated by a conic section, a determination of the corneal shape by biconic parameters is desired. The purpose of the paper is to introduce a straightforward mathematical approach for extracting clinically relevant parameters of corneal surface, such as radii of curvature and conic constants for principle meridians and astigmatism. A general description for modeling the ocular surfaces in a biconic form is given, based on which an implicit parametric surface fitting algorithm is introduced. The solution of the biconic fitting is obtained by a two sequential least squares optimization approach with constrains. The data input can be raw information from any corneal topographer with not necessarily a uniform data distribution. Various simulated and clinical data are studied including surfaces with rotationally symmetric and non-symmetric geometries. The clinical data was obtained from the Pentacam (Oculus) for the patient having undergone a refractive surgery. A sub-micrometer fitting accuracy was obtained for all simulated surfaces: 0,08 μm RMS fitting error at max for rotationally symmetric and 0,125 μm for non-symmetric surfaces. The astigmatism was recovered in a sub-minutes resolution. The equality in rotational symmetric and the superiority in non-symmetric surfaces of the presented model over the widely used quadric fitting model is shown. The introduced biconic surface fitting algorithm is able to recover the apical radii of curvature and conic constants in principle meridians. This methodology could be a platform for advanced IOL calculations and enhanced contact lens fitting. Copyright © 2014. Published by Elsevier GmbH.

  16. Step-height measurements on sand surfaces: A comparison between optical scanner and coordinate measuring machine

    DEFF Research Database (Denmark)

    Mohaghegh, Kamran; Yazdanbakhsh, Seyed Alireza; Tiedje, Niels Skat

    2016-01-01

    the same routine to touch the different positions on the polygonised mesh. Each measurement was repeated 5 times. The results of step height measurements on sand surfaces showed a maximum error of ± 12 µm for CMM, while scanner shows only ± 4 µm. Generally speaking, optical step height values were measured...

  17. The mean sea surface height and geoid along the Geosat subtrack from Bermuda to Cape Cod

    Science.gov (United States)

    Kelly, Kathryn A.; Joyce, Terrence M.; Schubert, David M.; Caruso, Michael J.

    1991-07-01

    Measurements of near-surface velocity and concurrent sea level along an ascending Geosat subtrack were used to estimate the mean sea surface height and the Earth's gravitational geoid. Velocity measurements were made on three traverses of a Geosat subtrack within 10 days, using an acoustic Doppler current profiler (ADCP). A small bias in the ADCP velocity was removed by considering a mass balance for two pairs of triangles for which expendable bathythermograph measurements were also made. Because of the large curvature of the Gulf Stream, the gradient wind balance was used to estimate the cross-track component of geostrophic velocity from the ADCP vectors; this component was then integrated to obtain the sea surface height profile. The mean sea surface height was estimated as the difference between the instantaneous sea surface height from ADCP and the Geosat residual sea level, with mesoscale errors reduced by low-pass filtering. The error estimates were divided into a bias, tilt, and mesoscale residual; the bias was ignored because profiles were only determined within a constant of integration. The calculated mean sea surface height estimate agreed with an independent estimate of the mean sea surface height from Geosat, obtained by modeling the Gulf Stream as a Gaussian jet, within the expected errors in the estimates: the tilt error was 0.10 m, and the mesoscale error was 0.044 m. To minimize mesoscale errors in the estimate, the alongtrack geoid estimate was computed as the difference between the mean sea level from the Geosat Exact Repeat Mission and an estimate of the mean sea surface height, rather than as the difference between instantaneous profiles of sea level and sea surface height. In the critical region near the Gulf Stream the estimated error reduction using this method was about 0.07 m. Differences between the geoid estimate and a gravimetric geoid were not within the expected errors: the rms mesoscale difference was 0.24 m rms.

  18. Estimation of Airborne Lidar-Derived Tropical Forest Canopy Height Using Landsat Time Series in Cambodia

    Directory of Open Access Journals (Sweden)

    Tetsuji Ota

    2014-11-01

    Full Text Available In this study, we test and demonstrate the utility of disturbance and recovery information derived from annual Landsat time series to predict current forest vertical structure (as compared to the more common approaches, that consider a sample of airborne Lidar and single-date Landsat derived variables. Mean Canopy Height (MCH was estimated separately using single date, time series, and the combination of single date and time series variables in multiple regression and random forest (RF models. The combination of single date and time series variables, which integrate disturbance history over the entire time series, overall provided better MCH prediction than using either of the two sets of variables separately. In general, the RF models resulted in improved performance in all estimates over those using multiple regression. The lowest validation error was obtained using Landsat time series variables in a RF model (R2 = 0.75 and RMSE = 2.81 m. Combining single date and time series data was more effective when the RF model was used (opposed to multiple regression. The RMSE for RF mean canopy height prediction was reduced by 13.5% when combining the two sets of variables as compared to the 3.6% RMSE decline presented by multiple regression. This study demonstrates the value of airborne Lidar and long term Landsat observations to generate estimates of forest canopy height using the random forest algorithm.

  19. Reproducibility of crop surface maps extracted from Unmanned Aerial Vehicle (UAV) derived digital surface maps

    KAUST Repository

    Parkes, Stephen

    2016-10-25

    Crop height measured from UAVs fitted with commercially available RGB cameras provide an affordable alternative to retrieve field scale high resolution estimates. The study presents an assessment of between flight reproducibility of Crop Surface Maps (CSM) extracted from Digital Surface Maps (DSM) generated by Structure from Motion (SfM) algorithms. Flights were conducted over a centre pivot irrigation system covered with an alfalfa crop. An important step in calculating the absolute crop height from the UAV derived DSM is determining the height of the underlying terrain. Here we use automatic thresholding techniques applied to RGB vegetation index maps to classify vegetated and soil pixels. From interpolation of classified soil pixels, a terrain map is calculated and subtracted from the DSM. The influence of three different thresholding techniques on CSMs are investigated. Median Alfalfa crop heights determined with the different thresholding methods varied from 18cm for K means thresholding to 13cm for Otsu thresholding methods. Otsu thresholding also gave the smallest range of crop heights and K means thresholding the largest. Reproducibility of median crop heights between flight surveys was 4-6cm for all thresholding techniques. For the flight conducted later in the afternoon shadowing caused soil pixels to be classified as vegetation in key locations around the domain, leading to lower crop height estimates. The range of crop heights was similar for both flights using K means thresholding (35-36cm), local minimum thresholding depended on whether raw or normalised RGB intensities were used to calculate vegetation indices (30-35cm), while Otsu thresholding had a smaller range of heights and varied most between flights (26-30cm). This study showed that crop heights from multiple survey flights are comparable, however, they were dependent on the thresholding method applied to classify soil pixels and the time of day the flight was conducted.

  20. Robust Analysis of Network-Based Real-Time Kinematic for GNSS-Derived Heights

    Directory of Open Access Journals (Sweden)

    Tae-Suk Bae

    2015-10-01

    Full Text Available New guidelines and procedures for real-time (RT network-based solutions are required in order to support Global Navigation Satellite System (GNSS derived heights. Two kinds of experiments were carried out to analyze the performance of the network-based real-time kinematic (RTK solutions. New test marks were installed in different surrounding environments, and the existing GPS benchmarks were used for analyzing the effect of different factors, such as baseline lengths, antenna types, on the final accuracy and reliability of the height estimation. The RT solutions are categorized into three groups: single-base RTK, multiple-epoch network RTK (mRTN, and single-epoch network RTK (sRTN. The RTK solution can be biased up to 9 mm depending on the surrounding environment, but there was no notable bias for a longer reference base station (about 30 km In addition, the occupation time for the network RTK was investigated in various cases. There is no explicit bias in the solution for different durations, but smoother results were obtained for longer durations. Further investigation is needed into the effect of changing the occupation time between solutions and into the possibility of using single-epoch solutions in precise determination of heights by GNSS.

  1. Robust Analysis of Network-Based Real-Time Kinematic for GNSS-Derived Heights.

    Science.gov (United States)

    Bae, Tae-Suk; Grejner-Brzezinska, Dorota; Mader, Gerald; Dennis, Michael

    2015-10-26

    New guidelines and procedures for real-time (RT) network-based solutions are required in order to support Global Navigation Satellite System (GNSS) derived heights. Two kinds of experiments were carried out to analyze the performance of the network-based real-time kinematic (RTK) solutions. New test marks were installed in different surrounding environments, and the existing GPS benchmarks were used for analyzing the effect of different factors, such as baseline lengths, antenna types, on the final accuracy and reliability of the height estimation. The RT solutions are categorized into three groups: single-base RTK, multiple-epoch network RTK (mRTN), and single-epoch network RTK (sRTN). The RTK solution can be biased up to 9 mm depending on the surrounding environment, but there was no notable bias for a longer reference base station (about 30 km) In addition, the occupation time for the network RTK was investigated in various cases. There is no explicit bias in the solution for different durations, but smoother results were obtained for longer durations. Further investigation is needed into the effect of changing the occupation time between solutions and into the possibility of using single-epoch solutions in precise determination of heights by GNSS.

  2. Digital holography on moving objects: multiwavelength height measurements on inclined surfaces

    Science.gov (United States)

    Schiller, Annelie; Beckmann, Tobias; Fratz, Markus; Belzer, Dominik; Bertz, Alexander; Carl, Daniel; Buse, Karsten

    2017-06-01

    Multiwavelength digital holography on moving objects enables fast and precise inline-measurements of surface pro files. Due to the use of multiple wavelengths, optically rough surfaces with structure heights in the micrometer range can be mapped unambiguously. In this work we explore the influence of the object velocity on height measurements on inclined surfaces. We show measurements using spatial-phase-shifting holography employing two wavelengths and object velocities of up to 90 mm/s with eye-safe cw-lasers with less than 1 mW of laser light. Despite motion blur exceeding the mean speckle size, reliable height measurements can be conducted at these velocities. The height map of a metal cone with two different slope angles (1° , 10° ) is measured at an exposure time of 2 ms. Using line shaped illumination, each frame yields a height map of approximately 2 x 17 mm2. The overlap between the frames allows averaging as the image is put together, improving data quality. The mean repeatability of the height information in the investigated setup is better than 4.5 µm at a synthetic wavelength of 214 µm.

  3. Quantification of the lift height for magnetic force microscopy using 3D surface parameters

    International Nuclear Information System (INIS)

    Nenadovic, M.; Strbac, S.; Rakocevic, Z.

    2010-01-01

    In this work, the quantitative conditions for the lift height for imaging of the magnetic field using magnetic force microscopy (MFM) were optimized. A thin cobalt film deposited on a monocrystalline silicon (1 0 0) substrate with a thickness of 55 nm and a thin nickel film deposited on a glass with a thickness of 600 nm were used as samples. The topography of the surface was acquired by tapping mode atomic force microscopy (AFM), while MFM imaging was performed in the lift mode for various lift heights. It was determined that the sensitivity of the measurements was about 10% higher for images obtained at a scan angle of 90 o compared to a scan angle of 0 deg. Therefore, the three-dimensional surface texture parameters, i.e., average roughness, skewness, kurtosis and the bearing ratio, were determined in dependence on the lift height for a scan angle of 90 deg. The results of the analyses of the surface parameters showed that the influence of the substrate and its texture on the magnetic force image could be neglected for lift heights above 40 nm and that the upper lift height limit is 100 nm. It was determined that the optimal values of the lift heights were in the range from 60 to 80 nm, depending on the nature of the sample and on the type of the tip used.

  4. Physical Retracking of Jason-1 LRM data for ocean surface height/gravity field determination

    Science.gov (United States)

    Jain, Maulik; Baltazar Andersen, Ole; Stenseng, Lars; Dall, Jørgen

    2013-04-01

    Jason-1 Low Resolution Mode (LRM) waveforms can be processed to extract accurate heights of the ocean surface. These heights are adjusted taking into account various corrections available. Further the along surface slope/variation of these ocean heights can be used to make an estimation of the gravity field. An important part of this gravity field estimation is dependent on the way the LRM waveform is processed. Thus a physical model based on an error function is used, and the LRM waveforms are fit to this model. A processing system made up of 2 parameter and 3 parameter fitting models are used in order to extract the most reliable ocean surface heights. The quality of the processing system is judged by evaluating the standard deviation of the sea surface anomaly obtained after all corrections and the mean sea surface/geoid are removed. The lower the value of the standard deviation of the sea surface anomaly, the better the quality of processing is. Hence, different processing schemes are considered and evaluated in order to conclude towards the best retracking procedure which would eventually result in high accuracy gravity field estimations.

  5. An atlas of monthly mean distributions of GEOSAT sea surface height, SSMI surface wind speed, AVHRR/2 sea surface temperature, and ECMWF surface wind components during 1988

    Science.gov (United States)

    Halpern, D.; Zlotnicki, V.; Newman, J.; Brown, O.; Wentz, F.

    1991-01-01

    Monthly mean global distributions for 1988 are presented with a common color scale and geographical map. Distributions are included for sea surface height variation estimated from GEOSAT; surface wind speed estimated from the Special Sensor Microwave Imager on the Defense Meteorological Satellite Program spacecraft; sea surface temperature estimated from the Advanced Very High Resolution Radiometer on NOAA spacecrafts; and the Cartesian components of the 10m height wind vector computed by the European Center for Medium Range Weather Forecasting. Charts of monthly mean value, sampling distribution, and standard deviation value are displayed. Annual mean distributions are displayed.

  6. Surface characteristics, equipment height, and the occurrence and severity of playground injuries.

    Science.gov (United States)

    Laforest, S; Robitaille, Y; Lesage, D; Dorval, D

    2001-03-01

    To evaluate whether surface characteristics (absorption level (g-max), material) and the height of play equipment are related to the occurrence and severity of injuries from falls. During the summers of 1991 and 1995, conformity of play equipment to Canadian standards was assessed in a random sample (n = 102) of Montreal public playgrounds. Surface absorption (g-max) was tested using a Max Hic instrument and the height of equipment was measured. Concurrently, all injuries presenting at the emergency department of Montreal's two children's hospitals were recorded and parents were interviewed. Inspected equipment was implicated in 185 injuries. The g-max measurements (1995 only) were available for 110 of these playground accidents. One third of falls (35 %) occurred on a surface exceeding 200 g and the risk of injury was three times greater than for g level lower than 150 (95% confidence interval (CI) 1.45 to 6.35). On surfaces having absorption levels between 150 g and 200 g, injuries were 1.8 times more likely (95% CI 0.91 to 3.57). Injuries were 2.56 times more likely to occur on equipment higher than 2 m compared with equipment lower than 1.5 m. Analysis of risk factors by severity of injury failed to show any positive relationships between the g-max or height and severity, whereas surface material was a good predictor of severity. This study confirms the relationships between risk of injury, surface resilience, and height of equipment, as well as between type of material and severity of injury. Our data suggest that acceptable limits for surface resilience be set at less than 200 g, and perhaps even less than 150 g, and not exceed 2 m for equipment height. These findings reinforce the importance of installing recommended materials, such as sand, beneath play equipment.

  7. Effect of the plate surface characteristics and gap height on yield stresses of a magnetorheological fluid

    International Nuclear Information System (INIS)

    Jonkkari, I; Syrjala, S; Kostamo, E; Kostamo, J; Pietola, M

    2012-01-01

    Effects of the plate material, surface roughness and measuring gap height on static and dynamic yield stresses of a magnetorheological (MR) fluid were investigated with a commercial plate–plate magnetorheometer. Magnetic and non-magnetic plates with smooth (Ra ∼ 0.3 μm) and rough (Ra ∼ 10 μm) surface finishes were used. It was shown by Hall probe measurements and finite element simulations that the use of magnetic plates or higher gap heights increases the level of magnetic flux density and changes the shape of the radial flux density profile. The yield stress increase caused by these factors was determined and subtracted from the measured values in order to examine only the effect of the wall characteristics or the gap height. Roughening of the surfaces offered a significant increase in the yield stresses for non-magnetic plates. With magnetic plates the yield stresses were higher to start with, but roughening did not increase them further. A significant part of the difference in measured stresses between rough non-magnetic and magnetic plates was caused by changes in magnetic flux density rather than by better contact of the particles to the plate surfaces. In a similar manner, an increase in gap height from 0.25 to 1.00 mm can lead to over 20% increase in measured stresses due to changes in the flux density profile. When these changes were compensated the dynamic yield stresses generally remained independent of the gap height, even in the cases where it was obvious that the wall slip was present. This suggests that with MR fluids the wall slip cannot be reliably detected by comparison of flow curves measured at different gap heights. (paper)

  8. Improving Jason-2 Sea Surface Heights within 10 km Offshore by Retracking Decontaminated Waveforms

    Directory of Open Access Journals (Sweden)

    Zhengkai Huang

    2017-10-01

    Full Text Available It is widely believed that altimetry-derived sea surface heights (SSHs in coastal zones are seriously degraded due to land contamination in altimeter waveforms from non-marine surfaces or due to inhomogeneous sea state conditions. Spurious peaks superimposed in radar waveforms adversely impact waveform retracking and hence require tailored algorithms to mitigate this problem. Here, we present an improved method to decontaminate coastal waveforms based on the waveform modification concept. SSHs within 10 km offshore are calculated from Jason-2 data by a 20% threshold retracker using decontaminated waveforms (DW-TR and compared with those using original waveforms and modified waveforms in four study regions. We then compare our results with retracked SSHs in the sensor geophysical data record (SGDR and with the state-of-the-art PISTACH (Prototype Innovant de Système de Traitement pour les Applications Côtières et l’Hydrologie and ALES (Adaptive Leading Edge Subwaveform products. Our result indicates that the DW-TR is the most robust retracker in the 0–10 km coastal band and provides consistent accuracy up to 1 km away from the coastline. In the four test regions, the DW-TR retracker outperforms other retrackers, with the smallest averaged standard deviations at 15 cm and 20 cm, as compared against the EGM08 (Earth Gravitational Model 2008 geoid model and tide gauge data, respectively. For the SGDR products, only the ICE retracker provides competitive SSHs for coastal applications. Subwaveform retrackers such as ICE3, RED3 and ALES perform well beyond 8 km offshore, but seriously degrade in the 0–8 km strip along the coast.

  9. Comparing RIEGL RiCOPTER UAV LiDAR Derived Canopy Height and DBH with Terrestrial LiDAR.

    Science.gov (United States)

    Brede, Benjamin; Lau, Alvaro; Bartholomeus, Harm M; Kooistra, Lammert

    2017-10-17

    In recent years, LIght Detection And Ranging (LiDAR) and especially Terrestrial Laser Scanning (TLS) systems have shown the potential to revolutionise forest structural characterisation by providing unprecedented 3D data. However, manned Airborne Laser Scanning (ALS) requires costly campaigns and produces relatively low point density, while TLS is labour intense and time demanding. Unmanned Aerial Vehicle (UAV)-borne laser scanning can be the way in between. In this study, we present first results and experiences with the RIEGL RiCOPTER with VUX ® -1UAV ALS system and compare it with the well tested RIEGL VZ-400 TLS system. We scanned the same forest plots with both systems over the course of two days. We derived Digital Terrain Model (DTMs), Digital Surface Model (DSMs) and finally Canopy Height Model (CHMs) from the resulting point clouds. ALS CHMs were on average 11.5 c m higher in five plots with different canopy conditions. This showed that TLS could not always detect the top of canopy. Moreover, we extracted trunk segments of 58 trees for ALS and TLS simultaneously, of which 39 could be used to model Diameter at Breast Height (DBH). ALS DBH showed a high agreement with TLS DBH with a correlation coefficient of 0.98 and root mean square error of 4.24 c m . We conclude that RiCOPTER has the potential to perform comparable to TLS for estimating forest canopy height and DBH under the studied forest conditions. Further research should be directed to testing UAV-borne LiDAR for explicit 3D modelling of whole trees to estimate tree volume and subsequently Above-Ground Biomass (AGB).

  10. Assessment of the quality of HY-2A satellite sea surface height data

    Science.gov (United States)

    Song, Qingtao; Gao, Xuemin; Wang, Zhaohui; Liu, Yuxin

    2017-10-01

    In August 2011, China successfully launched the Ocean II (HY-2A) satellite. HY-2A carries a dual-band radar altimeter with a calibrated microwave radiometer on the orbit. The main objective of HY-2A is to observe the elements of marine dynamic environment, including sea surface height. The evaluation of HY-2A satellite sea surface data quality is a necessary part of HY-2A satellite sea surface data application. We Used the HY-2A satellite 18th to 23th cycle data and the simultaneous Jason-2 data in orbit to analyze the deviation and evaluate of HY-2A satellite radar height data quality. The results show that the number of abnormal points in HY-2A satellite 18 to 23 cycles accounted for 12% of the total. HY-2A and Jason-2 sea level anomaly standard deviation of 7.0 cm that the accuracy of HY-2A reached the satisfaction index.

  11. Sea surface height determination in the arctic ocean from Cryosat2 SAR data, the impact of using different empirical retrackers

    DEFF Research Database (Denmark)

    Jain, Maulik; Andersen, Ole Baltazar; Stenseng, Lars

    2012-01-01

    Cryosat2 Level 1B SAR data can be processed using different empirical retrackers to determine the sea surface height and its variations in the Arctic Ocean. Two improved retrackers based on the combination of OCOG (Offset Centre of Gravity), Threshold methods and Leading Edge Retrieval is used...... to estimate the sea surface height in the Arctic Region. This sea surface height determination is to be compared with the Level2 sea surface height components available in the Cryosat2 data. Further a comparison is done with the marine gravity field for retracker performance evaluation....

  12. A macroecological analysis of SERA derived forest heights and implications for forest volume remote sensing.

    Directory of Open Access Journals (Sweden)

    Matthew Brolly

    Full Text Available Individual trees have been shown to exhibit strong relationships between DBH, height and volume. Often such studies are cited as justification for forest volume or standing biomass estimation through remote sensing. With resolution of common satellite remote sensing systems generally too low to resolve individuals, and a need for larger coverage, these systems rely on descriptive heights, which account for tree collections in forests. For remote sensing and allometric applications, this height is not entirely understood in terms of its location. Here, a forest growth model (SERA analyzes forest canopy height relationships with forest wood volume. Maximum height, mean, H₁₀₀, and Lorey's height are examined for variability under plant number density, resource and species. Our findings, shown to be allometrically consistent with empirical measurements for forested communities world-wide, are analyzed for implications to forest remote sensing techniques such as LiDAR and RADAR. Traditional forestry measures of maximum height, and to a lesser extent H₁₀₀ and Lorey's, exhibit little consistent correlation with forest volume across modeled conditions. The implication is that using forest height to infer volume or biomass from remote sensing requires species and community behavioral information to infer accurate estimates using height alone. SERA predicts mean height to provide the most consistent relationship with volume of the height classifications studied and overall across forest variations. This prediction agrees with empirical data collected from conifer and angiosperm forests with plant densities ranging between 10²-10⁶ plants/hectare and heights 6-49 m. Height classifications investigated are potentially linked to radar scattering centers with implications for allometry. These findings may be used to advance forest biomass estimation accuracy through remote sensing. Furthermore, Lorey's height with its specific relationship to

  13. A macroecological analysis of SERA derived forest heights and implications for forest volume remote sensing.

    Science.gov (United States)

    Brolly, Matthew; Woodhouse, Iain H; Niklas, Karl J; Hammond, Sean T

    2012-01-01

    Individual trees have been shown to exhibit strong relationships between DBH, height and volume. Often such studies are cited as justification for forest volume or standing biomass estimation through remote sensing. With resolution of common satellite remote sensing systems generally too low to resolve individuals, and a need for larger coverage, these systems rely on descriptive heights, which account for tree collections in forests. For remote sensing and allometric applications, this height is not entirely understood in terms of its location. Here, a forest growth model (SERA) analyzes forest canopy height relationships with forest wood volume. Maximum height, mean, H₁₀₀, and Lorey's height are examined for variability under plant number density, resource and species. Our findings, shown to be allometrically consistent with empirical measurements for forested communities world-wide, are analyzed for implications to forest remote sensing techniques such as LiDAR and RADAR. Traditional forestry measures of maximum height, and to a lesser extent H₁₀₀ and Lorey's, exhibit little consistent correlation with forest volume across modeled conditions. The implication is that using forest height to infer volume or biomass from remote sensing requires species and community behavioral information to infer accurate estimates using height alone. SERA predicts mean height to provide the most consistent relationship with volume of the height classifications studied and overall across forest variations. This prediction agrees with empirical data collected from conifer and angiosperm forests with plant densities ranging between 10²-10⁶ plants/hectare and heights 6-49 m. Height classifications investigated are potentially linked to radar scattering centers with implications for allometry. These findings may be used to advance forest biomass estimation accuracy through remote sensing. Furthermore, Lorey's height with its specific relationship to remote sensing

  14. Signal Processing for Determining Water Height in Steam Pipes with Dynamic Surface Conditions

    Science.gov (United States)

    Lih, Shyh-Shiuh; Lee, Hyeong Jae; Bar-Cohen, Yoseph

    2015-01-01

    An enhanced signal processing method based on the filtered Hilbert envelope of the auto-correlation function of the wave signal has been developed to monitor the height of condensed water through the steel wall of steam pipes with dynamic surface conditions. The developed signal processing algorithm can also be used to estimate the thickness of the pipe to determine the cut-off frequency for the low pass filter frequency of the Hilbert Envelope. Testing and analysis results by using the developed technique for dynamic surface conditions are presented. A multiple array of transducers setup and methodology are proposed for both the pulse-echo and pitch-catch signals to monitor the fluctuation of the water height due to disturbance, water flow, and other anomaly conditions.

  15. Temporal and spatial characteristics of sea surface height variability in the North Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    D. Cromwell

    2006-01-01

    Full Text Available We investigate the spatial and temporal variability of sea surface height (SSH in the North Atlantic basin using satellite altimeter data from October 1992–January 2004. Our primary aim is to provide a detailed description of such variability, including that associated with propagating signals. We also investigate possible correlations between SSH variability and atmospheric pressure changes as represented by climate indices. We first investigate interannual SSH variations by deriving the complex empirical orthogonal functions (CEOFs of altimeter data lowpass-filtered at 18 months. We determine the spatial structure of the leading four modes (both in amplitude and phase and also the associated principal component (PC time series. Using wavelet analysis we derive the time-varying spectral density of the PCs, revealing when particular modes were strongest between 1992–2004. The spatial pattern of the leading CEOF, comprising 30% of the total variability, displays a 5-year periodicity in phase; signal propagation is particularly marked in the Labrador Sea. The second mode, with a dominant 3-year signal, has strong variability in the eastern basin. Secondly, we focus on the Azores subtropical frontal zone. The leading mode (35% is strong in the south and east of this region with strong variations at 3- and 5-year periods. The second mode (21% has a near-zonal band of low variance between  22°–27° N, sandwiched between two regions of high variance. Thirdly, we lowpass filter the altimeter data at a cutoff of 30 days, instead of 18 months, in order to retain signals associated with propagating baroclinic Rossby waves and/or eddies. The leading mode is the annual steric signal, around 46% of the SSH variability. The third and fourth CEOFs,  11% of the remaining variability, are associated with westward propagation which is particularly dominant in a "waveband" between 32°–36° N. For all three cases considered above, no significant cross

  16. Sea Surface Height Variability and Eddy Statistical Properties in the Red Sea

    KAUST Repository

    Zhan, Peng

    2013-05-01

    Satellite sea surface height (SSH) data over 1992-2012 are analyzed to study the spatial and temporal variability of sea level in the Red Sea. Empirical orthogonal functions (EOF) analysis suggests the remarkable seasonality of SSH in the Red Sea, and a significant correlation is found between SSH variation and seasonal wind cycle. A winding-angle based eddy identification algorithm is employed to derive the mesoscale eddy information from SSH data. Totally more than 5500 eddies are detected, belonging to 2583 eddy tracks. Statistics suggest that eddies generate over the entire Red Sea, with two regions in the central basin of high eddy frequency. 76% of the detected eddies have a radius ranging from 40km to 100km, of which both intensity and absolute vorticity decrease with eddy radius. The average eddy lifespan is about 5 weeks, and eddies with longer lifespan tend to have larger radius but less intensity. Different deformation rate exists between anticyclonic eddies (AEs) and cyclonic eddies (CEs), those eddies with higher intensity appear to be less deformed and more circular. Inspection of the 84 long-lived eddies suggests the AEs tend to move a little more northward than CEs. AE generation during summer is obviously lower than that during other seasons, while CE generation is higher during spring and summer. Other features of AEs and CEs are similar with both vorticity and intensity reaching the summer peaks in August and winter peaks in January. Inter-annual variability reveals that the eddies in the Red Sea are isolated from the global event. The eddy property tendencies are different from the south and north basin, both of which exhibit a two-year cycle. Showing a correlation coefficient of -0.91, Brunt–Väisälä frequency is negatively correlated with eddy kinetic energy (EKE), which results from AE activities in the high eddy frequency region. Climatological vertical velocity shear variation is identical with EKE except in the autumn, suggesting the

  17. Quantitative evaluation of die casting surface defect severity by analyzing surface height

    Directory of Open Access Journals (Sweden)

    Yan Xu

    2017-11-01

    Full Text Available It is necessary in factories to assess the severity of the surface defects of castings, as a slight surface defect will be taken as qualified when it brings no bad effect or it can be removed by the subsequent processing. In practical production, professional technicians visually inspect the surface defect severity according to their individual experience. Therefore, it is difficult for them to maintain the same standard and accuracy in the subjective, tedious and labor-intensive work. Recently, image processing techniques based on optical images have been applied to achieve better accuracy and high efficiency. Unfortunately, optical images cannot directly quantify surface depth, which works as a crucial factor in the practical assessment of surface defect severity. The surface roughness evaluation algorithm, which takes into account of both area and depth information of the assessed surface, was applied to directly characterize surface defect severity based on surface asperity rather than optical image. The results using standard casting pieces show that surface defect severity has no apparent dependence on surface roughness. However, the subsequent results show that the root-mean-squared-deviation (RMSD of surface gradient of flow line defects positively correlates with the increase of defect severity. The other types of defect do not present such tendency. Thus, practical workpieces with flow line defects on the surface were used to verify the universality of this tendency. The results show that surface roughness of an unqualified workpiece is larger than that of a qualified workpiece after surface slope adjustment, but presents no obvious coincidence before the adjustment. In contrast, the RMSD of an unqualified workpiece, no matter before or after the adjustment, is larger than that of a qualified one.

  18. Spectral decomposition of internal gravity wave sea surface height in global models

    Science.gov (United States)

    Savage, Anna C.; Arbic, Brian K.; Alford, Matthew H.; Ansong, Joseph K.; Farrar, J. Thomas; Menemenlis, Dimitris; O'Rourke, Amanda K.; Richman, James G.; Shriver, Jay F.; Voet, Gunnar; Wallcraft, Alan J.; Zamudio, Luis

    2017-10-01

    Two global ocean models ranging in horizontal resolution from 1/12° to 1/48° are used to study the space and time scales of sea surface height (SSH) signals associated with internal gravity waves (IGWs). Frequency-horizontal wavenumber SSH spectral densities are computed over seven regions of the world ocean from two simulations of the HYbrid Coordinate Ocean Model (HYCOM) and three simulations of the Massachusetts Institute of Technology general circulation model (MITgcm). High wavenumber, high-frequency SSH variance follows the predicted IGW linear dispersion curves. The realism of high-frequency motions (>0.87 cpd) in the models is tested through comparison of the frequency spectral density of dynamic height variance computed from the highest-resolution runs of each model (1/25° HYCOM and 1/48° MITgcm) with dynamic height variance frequency spectral density computed from nine in situ profiling instruments. These high-frequency motions are of particular interest because of their contributions to the small-scale SSH variability that will be observed on a global scale in the upcoming Surface Water and Ocean Topography (SWOT) satellite altimetry mission. The variance at supertidal frequencies can be comparable to the tidal and low-frequency variance for high wavenumbers (length scales smaller than ˜50 km), especially in the higher-resolution simulations. In the highest-resolution simulations, the high-frequency variance can be greater than the low-frequency variance at these scales.

  19. Surface tree languages and parallel derivation trees

    NARCIS (Netherlands)

    Engelfriet, Joost

    1976-01-01

    The surface tree languages obtained by top-down finite state transformation of monadic trees are exactly the frontier-preserving homomorphic images of sets of derivation trees of ETOL systems. The corresponding class of tree transformation languages is therefore equal to the class of ETOL languages.

  20. On the hysteresis of the sea surface and its applicability to wave height predictions

    Science.gov (United States)

    Parsons, C. L.

    1977-01-01

    Because of the low dissipation rate of wave energy on the ocean's surface, the wave height at some location and time must be dependent upon wind fields in existence there at previous times and upon swell propagated there from other regions. To study these relationships, significant wave height (SWH) measurements from the Geos-3 radar altimeter are used in conjunction with anemometer windspeed measurements from weather ships, L, C, and R. During the passage of large cyclonic disturbances near the fixed locations of these vessels in the North Atlantic in February 1976, distinct hysteresis profiles that characterize the sea's memory during generation and dissipation conditions are observed. Examples are given that demonstrate the influences of cyclone intensity, movement, velocity, and shape on the configuration of these profiles.

  1. Anthropometry as a predictor of vertical jump heights derived from an instrumented platform.

    Science.gov (United States)

    Caruso, John F; Daily, Jeremy S; Mason, Melissa L; Shepherd, Catherine M; McLagan, Jessica R; Marshall, Mallory R; Walker, Ron H; West, Jason O

    2012-01-01

    The current study purpose examined the vertical height-anthropometry relationship with jump data obtained from an instrumented platform. Our methods required college-aged (n = 177) subjects to make 3 visits to our laboratory to measure the following anthropometric variables: height, body mass, upper arm length (UAL), lower arm length, upper leg length, and lower leg length. Per jump, maximum height was measured in 3 ways: from the subjects' takeoff, hang times, and as they landed on the platform. Standard multivariate regression assessed how well anthropometry predicted the criterion variance per gender (men, women, pooled) and jump height method (takeoff, hang time, landing) combination. Z-scores indicated that small amounts of the total data were outliers. The results showed that the majority of outliers were from jump heights calculated as women landed on the platform. With the genders pooled, anthropometry predicted a significant (p anthropometry-vertical jump relationship was not significant from heights calculated as subjects landed on the platform, likely due to the female outliers. Yet anthropometric data of men did predict a significant amount of variance from heights calculated when they landed on the platform; univariate correlations of men's data revealed that UAL was the best predictor. It was concluded that the large sample of men's data led to greater data heterogeneity and a higher univariate correlation. Because of our sample size and data heterogeneity, practical applications suggest that coaches may find our results best predict performance for a variety of college-aged athletes and vertical jump enthusiasts.

  2. Impact of Error in Lidar-Derived Canopy Height and Canopy Base Height on Modeled Wildfire Behavior in the Sierra Nevada, California, USA

    Directory of Open Access Journals (Sweden)

    Maggi Kelly

    2017-12-01

    Full Text Available Light detection and ranging (Lidar data can be used to create wall-to-wall forest structure and fuel products that are required for wildfire behavior simulation models. We know that Lidar-derived forest parameters have a non-negligible error associated with them, yet we do not know how this error influences the results of fire behavior modeling that use these layers as inputs. Here, we evaluated the influence of error associated with two Lidar data products—canopy height (CH and canopy base height (CBH—on simulated fire behavior in a case study in the Sierra Nevada, California, USA. We used a Monte Carlo simulation approach with expected randomized error added to each model input. Model 1 used the original, unmodified data, Model 2 incorporated error in the CH layer, and Model 3 incorporated error in the CBH layer. This sensitivity analysis showed that error in CH and CBH did not greatly influence the modeled conditional burn probability, fire size, or fire size distribution. We found that the expected error associated with CH and CBH did not greatly influence modeled results: conditional burn probability, fire size, and fire size distributions were very similar between Model 1 (original data, Model 2 (error added to CH, and Model 3 (error added to CBH. However, the impact of introduced error was more pronounced with CBH than with CH, and at lower canopy heights, the addition of error increased modeled canopy burn probability. Our work suggests that the use of Lidar data, even with its inherent error, can contribute to reliable and robust estimates of modeled forest fire behavior, and forest managers should be confident in using Lidar data products in their fire behavior modeling workflow.

  3. Long-Term Monitoring of Regional Sea Surface Height Variability Using High-Resolution Satellite Altimetry

    Science.gov (United States)

    Rice, A. E.; Crout, R. L.

    2017-12-01

    Shallow water altimetry is an emerging field that in recent years has rapidly gained attention for both the numerous applications it can offer to the oceanographic community (e.g. assessment of climate change impacts to the coastal zone; quantification of sea state etc.) and, depending on the altimeter used, for the wealth of available historical data that can be employed for climatological studies. In this study we focus on the long-term analysis of regional sea surface height anomaly (SSHA) variability over the mid and outer shelf (≥ 16 km from the coast) for 18 selected coastal altimeter tracks located on the east coast of the US and Asia for a period of eight years (294 passes from July 2008 to July 2016) using Jason-2 20 Hz altimeter data from the L2 AVISO-PISTACH experimental products. After implementing geophysical corrections to the raw altimeter range, signal noise in the individual SSH passes was reduced by applying a median filter followed by a 60-point (18 km) low-pass filter as in Birol and Delebeque (2014). Since individual altimeter passes did not cease to collect data at the same distance from the coastline, a nearest-point-to-land (NPTL) was determined for each track for statistical analysis of the data. NPTL time series and SSHA envelopes, computed by subtracting mean SSHAs from individual passes, were used for the analysis. A comparison of wind and water level gauge data to a US east coast track reveals correlation between SSHA and winds and a relationship to subtidal water level frequencies. Time series of NPTL for all tracks show intra-annual and inter and intra-seasonal variability, with higher and lower water levels linked to seasons. Lastly, envelope plots display higher SSHA variability over the mid shelf than the outer shelf, revealing the location and magnitude (up to 0.5 m water level differences) of setup and set down occurrences. Various products derived from the analysis that are useful for oceanographic operations, including water

  4. CMS: LiDAR-derived Biomass, Canopy Height and Cover, Sonoma County, California, 2013

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides estimates of above-ground biomass (AGB), canopy height, and percent tree cover at 30-m spatial resolution for Sonoma County, California, USA,...

  5. Mixing height derived from the DMI-HIRLAM NWP model, and used for ETEX dispersion modelling

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, J.H.; Rasmussen, A. [Danish Meteorological Inst., Copenhagen (Denmark)

    1997-10-01

    For atmospheric dispersion modelling it is of great significance to estimate the mixing height well. Mesoscale and long-range diffusion models using output from numerical weather prediction (NWP) models may well use NWP model profiles of wind, temperature and humidity in computation of the mixing height. This is dynamically consistent, and enables calculation of the mixing height for predicted states of the atmosphere. In autumn 1994, the European Tracer Experiment (ETEX) was carried out with the objective to validate atmospheric dispersion models. The Danish Meteorological Institute (DMI) participates in the model evaluations with the Danish Emergency Response Model of the Atmosphere (DERMA) using NWP model data from the DMI version of the High Resolution Limited Area Model (HIRLAM) as well as from the global model of the European Centre for Medium-Range Weather Forecast (ECMWF). In DERMA, calculation of mixing heights are performed based on a bulk Richardson number approach. Comparing with tracer gas measurements for the first ETEX experiment, a sensitivity study is performed for DERMA. Using DMI-HIRLAM data, the study shows that optimum values of the critical bulk Richardson number in the range 0.15-0.35 are adequate. These results are in agreement with recent mixing height verification studies against radiosonde data. The fairly large range of adequate critical values is a signature of the robustness of the method. Direct verification results against observed missing heights from operational radio-sondes released under the ETEX plume are presented. (au) 10 refs.

  6. Pulse-height response of silicon surface-barrier detectors to high-energy heavy ions

    International Nuclear Information System (INIS)

    Smith, G.D.

    1973-01-01

    The pulse-height defect (PHD) of high-energy heavy ions in silicon surface-barrier detectors can be divided into three components: (1) energy loss in the gold-surface layer, (2) a nuclear-stopping defect, and (3) a defect due to recombination of electron-hole pairs in the plasma created by the heavy ion. The plasma recombination portion of the PHD was the subject of this study using the variation of the PHD with (1) the angle of incidence of incoming heavy ions, and (2) changes in the detector bias. The Tandem Van de Graaff accelerator at Argonne National Laboratory was used to produce scattered beam ions ( 32 S, 35 Cl) and heavy target recoils (Ni, Cu, 98 Mo, Ag, Au) at sufficient energies to produce a significant recombination defect. The results confirm the existence of a recombination zone at the front surface of these detectors and the significance of plasma recombination as a portion of the pulse-height defect. (Diss. Abstr. Int., B)

  7. The Effects of Drop Height and Padding Surface on Bruising of Exportable Apple

    Directory of Open Access Journals (Sweden)

    D Ghanbarian

    2015-03-01

    Full Text Available Unfortunately despite the great ranking of Iran for apple production around the world, the export potential is not suitable. It seems that one of the major causes of poor quality for Iranian apple varieties is bruising damage of this product. Therefore, in this study, some factors affecting the apple bruising were addressed. For this purpose, factorial experiment in a completely randomized design with 72 treatments, including variety factor in three levels (Golden Delicious, Red Delicious and Granny Smith, type of padding surface in four levels (Cardboard on plastic, wood, Rubber on steel and apple and the drop height in six levels (5, 15, 25, 35, 45 and 55 cm with four replications were considered. Moreover, the maximum allowable drop heights of apples along with bruising volume estimation models were studied. Analysis of variance (ANOVA showed that bruising area and volume were significantly affected by all experimental parameters at the 1% level. The comparison test revealed that Granny Smith has tougher tissues and is less prone to vulnerability. Based on the results of this study, the maximum allowable drop heights for the Red Delicious, Golden Delicious and Granny Smith varieties were found to be 12, 15 and 20 cm, respectively. In addition, the effect of apple variety on the dependent parameters was significant. Based on the findings of this study, the bruising due to the impact of apple and apple was lower for the moving apples compared with the stationary apples.

  8. Does Heel Height Cause Imbalance during Sit-to-Stand Task: Surface EMG Perspective

    Directory of Open Access Journals (Sweden)

    Ganesh R. Naik

    2017-08-01

    Full Text Available The purpose of this study was to determine whether electromyography (EMG muscle activities around the knee differ during sit-to-stand (STS and returning task for females wearing shoes with different heel heights. Sixteen healthy young women (age = 25.2 ± 3.9 years, body mass index = 20.8 ± 2.7 kg/m2 participated in this study. Electromyography signals were recorded from the two muscles, vastus medialis (VM and vastus lateralis (VL that involve in the extension of knee. The participants wore shoes with five different heights, including 4, 6, 8, 10, and 12 cm. Surface electromyography (sEMG data were acquired during STS and stand-to-sit-returning (STSR tasks. The data was filtered using a fourth order Butterworth (band pass filter of 20–450 Hz frequency range. For each heel height, we extracted median frequency (MDF and root mean square (RMS features to measure sEMG activities between VM and VL muscles. The experimental results (based on MDF and RMS-values indicated that there is imbalance between vasti muscles for more elevated heels. The results are also quantified with statistical measures. The study findings suggest that there would be an increased likelihood of knee imbalance and fatigue with regular usage of high heel shoes (HHS in women.

  9. Influence of abutment height and surface roughness on in vitro retention of three luting agents.

    Science.gov (United States)

    Cano-Batalla, Jordi; Soliva-Garriga, Joan; Campillo-Funollet, Marc; Munoz-Viveros, Carlos A; Giner-Tarrida, Lluis

    2012-01-01

    This study evaluated the effects of abutment height, airborne-particle abrasion, and type of cement on the tensile resistance to dislodgement of cement-retained implant restorations. Three groups of 12 standardized abutments each were prepared with different heights (4 mm, 5 mm, and 6 mm) using a milling machine. Crowns were cast in cobalt-chrome using the lost-wax technique, airborne particle-abraded using 50-Μm aluminum oxide, and cleaned with acetone. Restorations were cemented using a noneugenol acrylic urethane cement, a resin-modified glass ionomer, or a zinc oxide-noneugenol cement. A 5-kg load was applied for 10 minutes. Samples were kept at 37°C and 100% humidity overnight. A tensile force was applied to the crown using a testing machine at a crosshead speed of 5 mm/minute until failure occurred. Next, the abutments were airborne particle-abraded with 50-Μm aluminum oxide, and the cementation and testing procedures were repeated. The effects of cement, abutment height, and surface treatment were evaluated statistically. There were significant differences among the cements. The resin-modified glass ionomer provided the greatest retention in all the tested conditions, while the zinc oxide-noneugenol cement produced the lowest retention values. Significant differences were also detected between 4-mm and 6-mm abutments, with the 6-mm abutments being more retentive. No differences were found between 4-mm and 5-mm abutments or between 5-mm and 6-mm abutments. The effect of airborne-particle abrasion was also found to be significant. A maximum increase of 90 N in retention force was observed after airborne-particle abrasion for the 5-mm abutments cemented with the acrylic urethane cement. Cement, airborne-particle abrasion, and abutment height can significantly influence retention of implant-supported crowns. Different parameters, including those specific to the patient, should be considered in the selection of a luting agent.

  10. Surface height adjustments in pyroclastic-flow deposits observed at Unzen volcano by JERS-1 SAR interferometry

    Science.gov (United States)

    Matthews, J. P.; Kamata, H.; Okuyama, S.; Yusa, Y.; Shimizu, H.

    2003-07-01

    number of possible causative mechanisms including hydroconsolidation initiated by the seepage of rainwater into a newly deposited ash sheet, deflation on gas release, basal erosion, settlement and substrate relaxation are discussed here. Given the relatively low emplacement temperatures of the Unzen ash (300-500°C), it is unlikely that viscous deformation within the body of the fresh ash deposits is responsible for the subsidence. Comparison of the 22 July 1993-1 December 1993 interferogram with a LANDSAT 4 Thematic Mapper image of Unzen, acquired on 10 January 1994, highlights a ribbon-like zone of radar decorrelation running along the course of the Mizunashi valley which marks the path of debris flows that occurred within the time interval between the two SAR images used in the construction of the interferogram. Overall, these results demonstrate the utility of interferometric SAR-derived surface height and coherence measurements for monitoring the pyroclastic- and debris-flow regimes of active volcanoes.

  11. Utilization of O4 slant column density to derive aerosol layer height from a space-borne UV–visible hyperspectral sensor: sensitivity and case study

    Directory of Open Access Journals (Sweden)

    S. S. Park

    2016-02-01

    Full Text Available The sensitivities of oxygen-dimer (O4 slant column densities (SCDs to changes in aerosol layer height are investigated using the simulated radiances by a radiative transfer model, the linearized pseudo-spherical vector discrete ordinate radiative transfer (VLIDORT, and the differential optical absorption spectroscopy (DOAS technique. The sensitivities of the O4 index (O4I, which is defined as dividing O4 SCD by 1040 molecules2 cm−5, to aerosol types and optical properties are also evaluated and compared. Among the O4 absorption bands at 340, 360, 380, and 477 nm, the O4 absorption band at 477 nm is found to be the most suitable to retrieve the aerosol effective height. However, the O4I at 477 nm is significantly influenced not only by the aerosol layer effective height but also by aerosol vertical profiles, optical properties including single scattering albedo (SSA, aerosol optical depth (AOD, particle size, and surface albedo. Overall, the error of the retrieved aerosol effective height is estimated to be 1276, 846, and 739 m for dust, non-absorbing, and absorbing aerosol, respectively, assuming knowledge on the aerosol vertical distribution shape. Using radiance data from the Ozone Monitoring Instrument (OMI, a new algorithm is developed to derive the aerosol effective height over East Asia after the determination of the aerosol type and AOD from the MODerate resolution Imaging Spectroradiometer (MODIS. About 80 % of retrieved aerosol effective heights are within the error range of 1 km compared to those obtained from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP measurements on thick aerosol layer cases.

  12. Utilization of O4 Slant Column Density to Derive Aerosol Layer Height from a Space-Borne UV-Visible Hyperspectral Sensor: Sensitivity and Case Study

    Science.gov (United States)

    Park, Sang Seo; Kim, Jhoon; Lee, Hanlim; Torres, Omar; Lee, Kwang-Mog; Lee, Sang Deok

    2016-01-01

    The sensitivities of oxygen-dimer (O4) slant column densities (SCDs) to changes in aerosol layer height are investigated using the simulated radiances by a radiative transfer model, the linearized pseudo-spherical vector discrete ordinate radiative transfer (VLIDORT), and the differential optical absorption spectroscopy (DOAS) technique. The sensitivities of the O4 index (O4I), which is defined as dividing O4 SCD by 10(sup 40) molecules (sup 2) per centimeters(sup -5), to aerosol types and optical properties are also evaluated and compared. Among the O4 absorption bands at 340, 360, 380, and 477 nanometers, the O4 absorption band at 477 nanometers is found to be the most suitable to retrieve the aerosol effective height. However, the O4I at 477 nanometers is significantly influenced not only by the aerosol layer effective height but also by aerosol vertical profiles, optical properties including single scattering albedo (SSA), aerosol optical depth (AOD), particle size, and surface albedo. Overall, the error of the retrieved aerosol effective height is estimated to be 1276, 846, and 739 meters for dust, non-absorbing, and absorbing aerosol, respectively, assuming knowledge on the aerosol vertical distribution shape. Using radiance data from the Ozone Monitoring Instrument (OMI), a new algorithm is developed to derive the aerosol effective height over East Asia after the determination of the aerosol type and AOD from the MODerate resolution Imaging Spectroradiometer (MODIS). About 80 percent of retrieved aerosol effective heights are within the error range of 1 kilometer compared to those obtained from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) measurements on thick aerosol layer cases.

  13. Utilization of O4 Slant Column Density to Derive Aerosol Layer Height from a Spaceborne UV-Visible Hyperspectral Sensor: Sensitivity and Case Study

    Science.gov (United States)

    Park, Sang Seo; Kim, Jhoon; Lee, Hanlim; Torres, Omar; Lee, Kwang-Mog; Lee, Sang Deok

    2016-01-01

    The sensitivities of oxygen-dimer (O4) slant column densities (SCDs) to changes in aerosol layer height are investigated using the simulated radiances by a radiative transfer model, the linearized pseudo-spherical vector discrete ordinate radiative transfer (VLIDORT), and the Differential Optical Absorption Spectroscopy (DOAS) technique. The sensitivities of the O4 index (O4I), which is defined as dividing O4 SCD by 10(exp 40) sq molecules cm(exp -5), to aerosol types and optical properties are also evaluated and compared. Among the O4 absorption bands at 340, 360, 380, and 477 nm, the O4 absorption band at 477 nm is found to be the most suitable to retrieve the aerosol effective height. However, the O4I at 477 nm is significantly influenced not only by the aerosol layer effective height but also by aerosol vertical profiles, optical properties including single scattering albedo (SSA), aerosol optical depth (AOD), particle size, and surface albedo. Overall, the error of the retrieved aerosol effective height is estimated to be 1276, 846, and 739 m for dust, non-absorbing, and absorbing aerosol, respectively, assuming knowledge on the aerosol vertical distribution shape. Using radiance data from the Ozone Monitoring Instrument (OMI), a new algorithm is developed to derive the aerosol effective height over East Asia after the determination of the aerosol type and AOD from the MODerate resolution Imaging Spectroradiometer (MODIS). About 80% of retrieved aerosol effective heights are within the error range of 1 km compared to those obtained from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) measurements on thick aerosol layer cases.

  14. The impact of variable building height on drag, flow and turbulence over a realistic suburban surface

    Science.gov (United States)

    Giometto, M. G.; Christen, A.; Calaf, M.; Parlange, M. B.

    2014-12-01

    In urban environments, where buildings have variable configurations and heights, the tallest structures have a disproportional impact on drag, mean flow and turbulence. Although wind-engineering studies document well the effects of individual high-rise buildings on the immediate surrounding, the impact of varying building heights on the larger horizontally averaged flow has not been quantified systematically for realistic urban configurations. We use Large Eddy Simulation (LES) as a means to study the fully developed turbulent flow over and within a 512 x 512 m2 subset of the true urban geometry in the city of Basel, Switzerland. A periodic LES domain is centered on the location of a tower, where measurements of turbulence were performed in 2001/02, which allows a direct validation of the LES at a specific location in the domain. The Lagrangian scale-dependent LES model is adopted to parametrize the subgrid stresses in the bulk of the flow and buildings are taken into account adopting a discrete-forcing-approach immersed boundary method (IBM), with the geometry taken from a highly accurate digital building model. A series of high-resolution LES runs are performed for various directions of the approaching flow, and with all buildings included and then buildings above a certain height threshold progressively removed, to isolate the impact of tall structures. Results show how the presence of isolated tall buildings strongly modifies the roughness properties of the entire urban roughness sublayer, causing an increase in resolved pressure forces, which contributes to the overall surface induced drag. In the presence of tall buildings the local structure of the roughness sublayer is partitioned into two regimes: fine scale wake turbulence and elongated, high speed streak-like motions, locked between the position of isolated structures, with their axis aligned in the stream wise direction. For arrays with differing building heights statistics significantly differ from

  15. A next generation altimeter for mapping the sea surface height variability: opportunities and challenges

    Science.gov (United States)

    Fu, Lee-Lueng; Morrow, Rosemary

    2016-07-01

    The global observations of the sea surface height (SSH) have revolutionized oceanography since the beginning of precision radar altimetry in the early 1990s. For the first time we have continuous records of SSH with spatial and temporal sampling for detecting the global mean sea level rise, the waxing and waning of El Niño, and the ocean circulation from gyres to ocean eddies. The limit of spatial resolution of the present constellation of radar altimeters in mapping SSH variability is approaching 100 km (in wavelength) with 3 or more simultaneous altimetric satellites in orbit. At scales shorter than 100 km, the circulation contains substantial amount of kinetic energy in currents, eddies and fronts that are responsible for the stirring and mixing of the ocean, especially from the vertical exchange of the upper ocean with the deep. A mission currently in development will use the technique of radar interferometry for making high-resolution measurement of the height of water over the ocean as well as on land. It is called Surface Water and Ocean Topography (SWOT), which is a joint mission of US NASA and French CNES, with contributions from Canada and UK. SWOT promises the detection of SSH at scales approaching 15 km, depending on the sea state. SWOT will make SSH measurement over a swath of 120 km with a nadir gap of 20 km in a 21-day repeat orbit. A conventional radar altimeter will provide measurement along the nadir. This is an exploratory mission with applications in oceanography and hydrology. The increased spatial resolution offers an opportunity to study ocean surface processes to address important questions about the ocean circulation. However, the limited temporal sampling poses challenges to map the evolution of the ocean variability that changes rapidly at the small scales. The measurement technique and the development of the mission will be presented with emphasis on its science program with outlook on the opportunities and challenges.

  16. Absolute Height of Sea Surface by Trajectory of GPS Antennae Over Submerged Pressure Gauges

    Science.gov (United States)

    Bouin, M.; Calmant, S.; Cheng, K.; Ballu, V.; Shum, C. K.; Testut, L.

    2003-12-01

    Water height data provided by seafloor tide gauges is a combination of sea-level variations and ground motion. Both of these signals are of scientific interest, but they must be separated in order to be useful. Estimating ground motion is specially important in very tectonically active areas such as the Pacific Ocean rim. One promising method to separate the two contributions is to use satellite altimetry data which gives absolute water height, but these data must be calibrated using ground truth measurements. Once different components of the signal are separated, bottom pressure gauges can be used to detect vertical movements of the seafloor such as co-seismic or slow inter-seismic motions. The Vanuatu archipelago is part of the Pacific ring of fire, where plates are rapidly converging. In the area, movements are very rapid and the seismic activity is intense, which gives a good opportunity to study deformation and seismic cycle. To get an integrate picture of vertical deformation over one plate and between the two plates, one needs to be able to monitor vertical movements on both underwater and emerged areas. We conducted an experiment in the Vanuatu archipelago, South-West Pacific, to compare measurements from bottom pressure gauges located beneath altimetry satellite tracks with sea surface altitude measurements from GPS. Two bottom pressure gauges are immerged since Nov. 1999 on Sabine bank (15.90° S, 166.14° E) and Wusi Bank (15.34° S, 166.55° E), West of Santo island, Vanuatu. In order to perform absolute calibrations of JASON and ENVISAT altimeters that overfly the Wusi and Sabine banks, respectively, we performed GPS measurements of instantaneous sea surface altitude. The GPS antennae were fixed on top of the 30m long R/V Alis. An inertial unit also recorded the high frequency vessel motions. The height of the antennae over the sea surface was measured using a laser distancemeter in calibration sessions during particularly calm sea states. We present

  17. Physical Retracking of Cryosat-2 Low Resolution Mode data for ocean surface height and gravity field estimation in open ocean

    Science.gov (United States)

    Jain, Maulik; Baltazar Andersen, Ole; Dall, Jorgen; Stenseng, Lars

    2014-05-01

    Cryosat-2 Low Resolution Mode (LRM) altimetric data is processed to determine precise ocean surface heights and gravity fields in open ocean. These ocean surface heights are corrected using various geophysical corrections available. The along track variation of the ocean surface height anomaly is used to determine the gravity field. The quality of this gravity field estimation is dependent on the precision in the ocean surface height anomaly. Thus a three/two parameter based physical model based on an error function is used, and the Cryosat-2 LRM waveforms are fit to this model. The fitting routines which employ the Levenberg Marquadt technique generate estimated values of retracked epochs which are used to compute the ocean surface heights. A two step processing system made up of sequential 3 parameter (amplitude, rise time, retracked epoch) and 2 parameter (amplitude, retracked epoch) fitting models are used to determine precise ocean surface heights. The quality of the processing system is judged by evaluating the standard deviation of the ocean surface height anomaly obtained after all corrections and the mean sea surface/geoid are removed. The lower the value of the standard deviation of the ocean surface height anomaly, the better the quality of processing is. Hence, different processing schemes are considered and evaluated in order to conclude towards the best retracking procedure which would eventually result in high accuracy gravity field estimations. Also, the quality on the precision is judged by analyzing the standard deviation in the gravity field anomaly. The gravity field anomaly is obtained by subtracting the retracked gravity field with the marine gravity field available. A lower value of the standard deviation in the gravity field anomaly indicates a more precise retracking algorithm. Using the two retracker performance evaluation strategies, namely the ocean surface height anomaly and the gravity field anomaly, it was concluded that the three

  18. Assimilation of ocean sea-surface height observations of mesoscale eddies

    Science.gov (United States)

    Weiss, Jeffrey B.; Grooms, Ian

    2017-12-01

    Mesoscale eddies are one of the dominant sources of variability in the world's oceans. With eddy-resolving global ocean models, it becomes important to assimilate observations of mesoscale eddies to correctly represent the state of the mesoscale. Here, we investigate strategies for assimilating a reduced number of sea-surface height observations by focusing on the coherent mesoscale eddies. The study is carried out in an idealized perfect-model framework using two-layer forced quasigeostrophic dynamics, which captures the dominant dynamics of ocean mesoscale eddies. We study errors in state-estimation as well as error growth in forecasts and find that as fewer observations are assimilated, assimilating at vortex locations results in reduced state estimation and forecast errors.

  19. Multimodel simulations of Arctic Ocean sea surface height variability in the period 1970-2009

    DEFF Research Database (Denmark)

    Koldunov, Nikolay V.; Serra, Nuno; Koehl, Armin

    2014-01-01

    is in reasonable agreement with available measurements. Focusing on results from one of the models for a detailed analysis, it is shown that the decadal-scale SSH variability over shelf areas and deep parts of the Arctic Ocean have pronounced differences that are determined mostly by salinity variations. A further......The performance of several numerical ocean models is assessed with respect to their simulation of sea surface height (SSH) in the Arctic Ocean, and the main patterns of SSH variability and their causes over the past 40 years (1970-2009) are analyzed. In comparison to observations, all tested models...... of low-salinity shelf water. Overall, we show that present-day models can be used for investigating the reasons for low-frequency SSH variability in the region....

  20. Silicon surface biofunctionalization with dopaminergic tetrahydroisoquinoline derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Lucena-Serrano, A.; Lucena-Serrano, C.; Contreras-Cáceres, R.; Díaz, A.; Valpuesta, M. [Dep. Química Orgánica, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga (Spain); Cai, C. [Dep. Chemistry, University of Houston, Houston, TX 77204-5003 (United States); López-Romero, J.M., E-mail: jmromero@uma.es [Dep. Química Orgánica, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga (Spain)

    2016-01-01

    Graphical abstract: - Highlights: • Two dopaminergic tetrahydroisoquinolines (THI) were synthesized. • Vinyl-terminated THI incorporated onto the H−Si(1 1 1) substrates via a hydrosilylation. • The highest yield in coverage was obtained in DMSO, at 4 h of irradiation and 0.1 mbar of vacuum. • Alkynyl-terminated Si surface was produced for incorporation of azide-THI by click reaction. • Best yields on grafted molecule were obtained by click reaction in absence of ascorbic acid. - Abstract: In this work we grafted vinyl- and azido-terminated tetrahydroisoquinolines (compounds 1 and 2, respectively) onto H−Si(1 1 1) silicon wafers obtaining highly stable modified surfaces. A double bond was incorporated into the tetrahydroisoquinoline structure of 1 to be immobilized by a light induced hydrosilylation reaction on hydrogen-terminated Si(1 1 1). The best results were obtained employing a polar solvent (DMSO), rather than a non-polar solvent (toluene). The azide derivative 2 was grafted onto alkenyl-terminated silicon substrates with copper-catalyzed azide-alkyne cycloaddition (CuAAC). Atomic force microscopy (AFM), contact angle goniometry (CA) and X-ray photoemission spectroscopy (XPS) were used to demonstrate the incorporation of 1 and 2 into the surfaces, study the morphology of the modified surfaces and to calculate the yield of grafting and surface coverage. CA measurements showed the increase in the surface hydrophobicity when 1 or 2 were incorporated into the surface. Moreover, compounds 1 and 2 were prepared starting from 1-(p-nitrophenyl)tetrahydroisoquinoline 3 under smooth conditions and in good yields. The structures of 1 and 2 were designed with a reduced A-ring, two substituents at positions C-6 and C-7, an N-methyl group and a phenyl moiety at C-1 in order to provide a high affinity against dopaminergic receptors. Moreover, O-demethylation of 1 was carried out once it was adsorbed onto the surface by treatment with BBr{sub 3}. The method

  1. Adjusting altimetric sea surface height observations in coastal regions. Case study in the Greek Seas

    Directory of Open Access Journals (Sweden)

    Mintourakis Ioannis

    2014-09-01

    Full Text Available When processing satellite altimetry data for Mean Sea Surface (MSS modelling in coastal environments many problems arise. The degradation of the accuracy of the Sea Surface Height (SSH observations close to the coastline and the usually irregular pattern and variability of the sea surface topography are the two dominant factors which have to be addressed. In the present paper, we study the statistical behavior of the SSH observations in relation to the range from the coastline for many satellite altimetry missions and we make an effort to minimize the effects of the ocean variability. Based on the above concepts we present a process strategy for the homogenization of multi satellite altimetry data that takes advantage ofweighted SSH observations and applies high degree polynomials for the adjustment and their uniffcation at a common epoch. At each step we present the contribution of each concept to MSS modelling and then we develop a MSS, a marine geoid model and a grid of gravity Free Air Anomalies (FAA for the area under study. Finally, we evaluate the accuracy of the resulting models by comparisons to state of the art global models and other available data such as GPS/leveling points, marine GPS SSH’s and marine gravity FAA’s, in order to investigate any progress achieved by the presented strategy

  2. Effects of airway surface liquid height on the kinetics of extracellular nucleotides in airway epithelia.

    Science.gov (United States)

    Amarante, Tauanne D; da Silva, Jafferson K L; Garcia, Guilherme J M

    2014-12-21

    Experimental techniques aimed at measuring the concentration of signaling molecules in the airway surface liquid (ASL) often require an unrealistically large ASL volume to facilitate sampling. This experimental limitation, prompted by the difficulty of pipetting liquid from a very shallow layer (~15 μm), leads to dilution and the under-prediction of physiologic concentrations of signaling molecules that are vital to the regulation of mucociliary clearance. Here, we use a computational model to describe the effect of liquid height on the kinetics of extracellular nucleotides in the airway surface liquid coating respiratory epithelia. The model consists of a reaction-diffusion equation with boundary conditions that represent the enzymatic reactions occurring on the epithelial surface. The simulations reproduce successfully the kinetics of extracellular ATP following hypotonic challenge for ASL volumes ranging from 25 μl to 500 μl in a 12-mm diameter cell culture. The model reveals that [ATP] and [ADO] reach 1200 nM and 2200 nM at the epithelial surface, respectively, while their volumetric averages remain less than 200 nM at all times in experiments with a large ASL volume (500 μl). These findings imply that activation of P2Y2 and A2B receptors is robust after hypotonic challenge, in contrast to what could be concluded based on experimental measurements of volumetric concentrations in large ASL volumes. Finally, given the central role that ATP and ADO play in regulating mucociliary clearance, we investigated which enzymes, when inhibited, provide the greatest increase in ATP and ADO concentrations. Our findings suggest that inhibition of NTPDase1/highTNAP would cause the greatest increase in [ATP] after hypotonic challenge, while inhibition of the transporter CNT3 would provide the greatest increase in [ADO]. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Improving the Accuracy of Coastal Sea Surface Heights by Retracking Decontaminated Radar Altimetry Waveforms

    Science.gov (United States)

    Huang, Zhengkai; Wang, Haihong; Luo, Zhicai

    2017-04-01

    Due to the complex coastal topography and energetic ocean dynamics effect, the return echoes are contaminated while the satellite footprint approaches or leaves the coastline. Specular peaks are often induced in the trailing edges of contaminated waveforms, thus leading the error in the determination of the leading edge and associated track offset in the waveform retracking process. We propose an improved algorithm base on Tseng's modification method to decontaminated coastal (0-7 km from coastline) waveforms, thus improving both the utilization and precision of coastal sea surface height (SSH). Using the Envisat/Jason-2 SGDR data, the shortcoming of Tseng's method is pointed out and the novel algorithm is proposed by revising the strategy of selecting reference waveform and determining weight for removing outlier. The reference waveform of the decontaminated technology is closer to the real waveform of the offshore area, which avoids the over-modification problem of Tseng method. The sea-level measurements from tide gauge station and geoid height from EGM2008 model were used to validate the retracking strategy. Experimental results show that decontaminated waveform was more suitable than original and Tseng modified waveform and has uniform performance in both compare to the tide gauge and geoid. The retrieved altimetry data in the 0-1km and 1-7km coastal zone indicate that threshold retracker with decontaminated waveform have STD of 73.8cm and 33cm as compared with in situ gauge data,which correspond to 62.1% and 58% in precession compared to the unretracked altimetry measurements. The retracked SSHs are better in two coastal (0-1 km and 1-7km) zones, which have STD of 11.9cm and 22.7cm as compared with geoid height. Furthermore, the comparisons shows that the precision of decontaminated technology improve 0.3cm and 3.3cm than the best result of PISTACH product in coastal sea. This work is supported by the National Natural Science Foundation of China (Grant Nos

  4. Step-height standards based on the rapid formation of monolayer steps on the surface of layered crystals

    Energy Technology Data Exchange (ETDEWEB)

    Komonov, A.I. [Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences (ISP SBRAS), pr. Lavrentieva 13, Novosibirsk 630090 (Russian Federation); Prinz, V.Ya., E-mail: prinz@isp.nsc.ru [Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences (ISP SBRAS), pr. Lavrentieva 13, Novosibirsk 630090 (Russian Federation); Seleznev, V.A. [Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences (ISP SBRAS), pr. Lavrentieva 13, Novosibirsk 630090 (Russian Federation); Kokh, K.A. [Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences (IGM SB RAS), pr. Koptyuga 3, Novosibirsk 630090 (Russian Federation); Shlegel, V.N. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences (NIIC SB RAS), pr. Lavrentieva 3, Novosibirsk 630090 (Russian Federation)

    2017-07-15

    Highlights: • Easily reproducible step-height standard for SPM calibrations was proposed. • Step-height standard is monolayer steps on the surface of layered single crystal. • Long-term change in surface morphology of Bi{sub 2}Se{sub 3} and ZnWO{sub 4} was investigated. • Conducting surface of Bi{sub 2}Se{sub 3} crystals appropriate for calibrating STM. • Ability of robust SPM calibrations under ambient conditions were demonstrated. - Abstract: Metrology is essential for nanotechnology, especially for structures and devices with feature sizes going down to nm. Scanning probe microscopes (SPMs) permits measurement of nanometer- and subnanometer-scale objects. Accuracy of size measurements performed using SPMs is largely defined by the accuracy of used calibration measures. In the present publication, we demonstrate that height standards of monolayer step (∼1 and ∼0.6 nm) can be easily prepared by cleaving Bi{sub 2}Se{sub 3} and ZnWO{sub 4} layered single crystals. It was shown that the conducting surface of Bi{sub 2}Se{sub 3} crystals offers height standard appropriate for calibrating STMs and for testing conductive SPM probes. Our AFM study of the morphology of freshly cleaved (0001) Bi{sub 2}Se{sub 3} surfaces proved that such surfaces remained atomically smooth during a period of at least half a year. The (010) surfaces of ZnWO{sub 4} crystals remained atomically smooth during one day, but already two days later an additional nanorelief of amplitude ∼0.3 nm appeared on those surfaces. This relief, however, did not further grow in height, and it did not hamper the calibration. Simplicity and the possibility of rapid fabrication of the step-height standards, as well as their high stability, make these standards available for a great, permanently growing number of users involved in 3D printing activities.

  5. Sea Surface Height Determination In The Arctic Using Cryosat-2 SAR Data From Primary Peak Empirical Retrackers

    DEFF Research Database (Denmark)

    Jain, Maulik; Andersen, Ole Baltazar; Dall, Jørgen

    2015-01-01

    SAR waveforms from Cryosat-2 are processed using primary peak empirical retrackers to determine the sea surface height in the Arctic. The empirical retrackers investigated are based on the combination of the traditional OCOG (Offset Center of Gravity) and threshold methods with primary peak...... are processed using such primary peak retrackers. The sea surface heights determined are compared with the sea surface heights generated by the ESA Retracker as available in the Cryosat-2 Level-2 dataset from 2012. Performance of the primary peak retrackers is also compared with the traditional OCOG, threshold...... extraction. The primary peak retrackers involve the application of retracking algorithms on just the primary peak of the waveform instead of the complete reflected waveform. These primary peak empirical retrackers are developed for Cryosat-2 SAR data. This is the first time SAR data in the Arctic...

  6. An atlas of monthly mean distributions of SSMI surface wind speed, AVHRR/2 sea surface temperature, AMI surface wind velocity, TOPEX/POSEIDON sea surface height, and ECMWF surface wind velocity during 1993

    Science.gov (United States)

    Halpern, D.; Fu, L.; Knauss, W.; Pihos, G.; Brown, O.; Freilich, M.; Wentz, F.

    1995-01-01

    The following monthly mean global distributions for 1993 are presented with a common color scale and geographical map: 10-m height wind speed estimated from the Special Sensor Microwave Imager (SSMI) on a United States (U.S.) Air Force Defense Meteorological Satellite Program (DMSP) spacecraft; sea surface temperature estimated from the Advanced Very High Resolution Radiometer (AVHRR/2) on a U.S. National Oceanic and Atmospheric Administration (NOAA) satellite; 10-m height wind speed and direction estimated from the Active Microwave Instrument (AMI) on the European Space Agency (ESA) European Remote Sensing (ERS-1) satellite; sea surface height estimated from the joint U.S.-France Topography Experiment (TOPEX)/POSEIDON spacecraft; and 10-m height wind speed and direction produced by the European Center for Medium-Range Weather Forecasting (ECMWF). Charts of annual mean, monthly mean, and sampling distributions are displayed.

  7. Sea surface height evidence for long-term warming effects of tropical cyclones on the ocean.

    Science.gov (United States)

    Mei, Wei; Primeau, François; McWilliams, James C; Pasquero, Claudia

    2013-09-17

    Tropical cyclones have been hypothesized to influence climate by pumping heat into the ocean, but a direct measure of this warming effect is still lacking. We quantified cyclone-induced ocean warming by directly monitoring the thermal expansion of water in the wake of cyclones, using satellite-based sea surface height data that provide a unique way of tracking the changes in ocean heat content on seasonal and longer timescales. We find that the long-term effect of cyclones is to warm the ocean at a rate of 0.32 ± 0.15 PW between 1993 and 2009, i.e., ∼23 times more efficiently per unit area than the background equatorial warming, making cyclones potentially important modulators of the climate by affecting heat transport in the ocean-atmosphere system. Furthermore, our analysis reveals that the rate of warming increases with cyclone intensity. This, together with a predicted shift in the distribution of cyclones toward higher intensities as climate warms, suggests the ocean will get even warmer, possibly leading to a positive feedback.

  8. Intraseasonal Variability of the Equatorial Indian Ocean Observed from Sea Surface Height, Wind, and Temperature Data

    Science.gov (United States)

    Fu, Lee-Lueng

    2007-01-01

    The forcing of the equatorial Indian Ocean by the highly periodic monsoon wind cycle creates many interesting intraseasonal variabilities. The frequency spectrum of the wind stress observations from the European Remote Sensing Satellite scatterometers reveals peaks at the seasonal cycle and its higher harmonics at 180, 120, 90, and 75 days. The observations of sea surface height (SSH) from the Jason and Ocean Topography Experiment (TOPEX)/Poseidon radar altimeters are analyzed to study the ocean's response. The focus of the study is on the intraseasonal periods shorter than the annual period. The semiannual SSH variability is characterized by a basin mode involving Rossby waves and Kelvin waves traveling back and forth in the equatorial Indian Ocean between 10(deg)S and 10(deg)N. However, the interference of these waves with each other masks the appearance of individual Kelvin and Rossby waves, leading to a nodal point (amphidrome) of phase propagation on the equator at the center of the basin. The characteristics of the mode correspond to a resonance of the basin according to theoretical models. The theory also calls for similar modes at 90 and 60 days.

  9. Determination of Mean Dynamic Topography (MDT) to Bridge Geoid and Mean Sea Surface Height (SSH) with a New Elliptic Equation

    Science.gov (United States)

    Chu, P. C.

    2016-12-01

    Mean dynamic topography (MDT, η) bridges the geoid and the mean sea surface (from satellite altimetry) and constrains large scale surface geostrophic circulations. It can be estimated from either satellite or underwater ocean temperature (T) and salinity (S) data. Satellite altimeter measures sea surface height (SSH) with high precision and unique resolution above a reference ellipsoid (not geoid). Two Gravity Recovery and Climate Experiment (GRACE) satellites launched in 2002, provide data to compute the marine geoid [called the GRACE Gravity Model (GGM)] (see website: http://www.csr.utexas.edu/grace/). The MDT is the difference of altimetry-derived mean SSH and the mean marine geoid (using GGM or pre-GRACE gravity model such as EGM96). A major difficulty arises that the spatial variations in mean SSH and marine geoid are approximately two orders of magnitude larger than the spatial variations in η.The second approach (using T, Sdata) is based on geostrophic balance, which is at the minimum energy state in the linear Boussinesq primitive equations with conservation of potential vorticity. In this paper, a new elliptic equation, -[∂x(gh/f2)∂xη+∂y(gh/f2)∂yη]+η = (g/f2)(∂C/∂x-∂B/∂y)is derived to determine MDT with H the water depth, g the gravitational acceleration, and coefficients (B, C) depend on 3D mean temperature (T) and salinity (S) data. Numerical approach transforms the elliptic equation into a set of well-posed linear algebraic equations of η at grid points. The solution for the North Atlantic Ocean (100oW-6oW, 7oN-72oN) on 1oX1ogrids with the coefficients (B, C) calculated from the three-dimensional (T, S) data of the NOAA National Centers for Environmental Information (NCEI) World Ocean Atlas 2013 version 2 (http://www.nodc.noaa.gov/OC5/woa13/woa13data.html) and H from the NOAA ETOPO5 (https://www.ngdc.noaa.gov/mgg/fliers/93mgg01.html), compares well with the difference (also considered as the MDT) between the time-averaged SSH and

  10. A sensitivity-based approach to optimize the surface treatment of a low-height tramway noise barrier

    Science.gov (United States)

    Jolibois, Alexandre

    Transportation noise has become a main nuisance in urban areas, in the industrialized world and across the world, to the point that according to the World Health Organization 65% of the European population is exposed to excessive noise and 20% to night-time levels that may harm their health. There is therefore a need to find new ways to mitigate transportation noise in urban areas. In this work, a possible device to achieve this goal is studied: a low-height noise barrier. It consists of a barrier typically less than one meter high placed close to the source, designed to decrease significantly the noise level for nearby pedestrians and cyclists. A numerical method which optimizes the surface treatment of a low-height barrier in order to increase its insertion loss is presented. Tramway noise barriers are especially studied since the noise sources are in this case close to the ground and would be attenuated more by the barrier. The acoustic behavior of the surface treatment is modeled via its admittance. It can be itself described by a few parameters (flow resistivity, geometrical dimensions...), which can then be optimized. It is proposed to couple porous layers and micro-perforated panel (MPP) resonators in order to take advantage of their different acoustic properties. Moreover, the optimization is achieved using a sensitivity-based method, since in this framework the gradient of the attenuation can be evaluated accurately and efficiently. Several shapes are considered: half-cylinder, quarter-cylinder, straight wall, T-shape and square shape. In the case of a half-cylindrical geometry, a semi-analytical solution for the sound field in terms of a series of cylindrical waves is derived, which simplifies the sensitivity calculation and optimization process. The boundary element method (BEM) is used to evaluate the attenuation for the remaining shapes, and in this case the sensitivity is evaluated using the adjoint state approach. For all considered geometries, it is

  11. Eddy heat flux across the Antarctic Circumpolar Current estimated from sea surface height standard deviation

    Science.gov (United States)

    Foppert, Annie; Donohue, Kathleen A.; Watts, D. Randolph; Tracey, Karen L.

    2017-08-01

    Eddy heat flux (EHF) is a predominant mechanism for heat transport across the zonally unbounded mean flow of the Antarctic Circumpolar Current (ACC). Observations of dynamically relevant, divergent, 4 year mean EHF in Drake Passage from the cDrake project, as well as previous studies of atmospheric and oceanic storm tracks, motivates the use of sea surface height (SSH) standard deviation, H*, as a proxy for depth-integrated, downgradient, time-mean EHF (>[EHF>¯>]) in the ACC. Statistics from the Southern Ocean State Estimate corroborate this choice and validate throughout the ACC the spatial agreement between H* and >[EHF>¯>] seen locally in Drake Passage. Eight regions of elevated >[EHF>¯>] are identified from nearly 23.5 years of satellite altimetry data. Elevated cross-front exchange usually does not span the full latitudinal width of the ACC in each region, implying a hand-off of heat between ACC fronts and frontal zones as they encounter the different >[EHF>¯>] hot spots along their circumpolar path. Integrated along circumpolar streamlines, defined by mean SSH contours, there is a convergence of ∮>[EHF>¯>] in the ACC: 1.06 PW enters from the north and 0.02 PW exits to the south. Temporal trends in low-frequency [EHF] are calculated in a running-mean sense using H* from overlapping 4 year subsets of SSH. Significant increases in downgradient [EHF] magnitude have occurred since 1993 at Kerguelen Plateau, Southeast Indian Ridge, and the Brazil-Malvinas Confluence, whereas the other five >[EHF>¯>] hot spots have insignificant trends of varying sign.

  12. Step-height measurements on sand surfaces: A comparison between optical scanner and coordinate measuring machine

    DEFF Research Database (Denmark)

    Mohaghegh, Kamran; Yazdanbakhsh, Seyed Alireza; Tiedje, Niels Skat

    2016-01-01

    based on triangulation principle using fringe projection was also used to measure the step heights resulting in a point cloud for each scanning. A similar measurement procedure with scanner was made using the scanners software to simulate a ball probe with the same size of CMM probe and following....... In this work step-heights ranging from 0.1 mm to 5.0 mm were made on 6 customised sand samples with an average grain size of 230 µm, produced using a hard binder that can be scanned both by tactile and optical probes. The step-heights were measured using a CMM with ø8 mm tactile probe. An optical 3D scanner...

  13. The Influence of Structure Heights and Opening Angles of Micro- and Nanocones on the Macroscopic Surface Wetting Properties

    Science.gov (United States)

    Schneider, Ling; Laustsen, Milan; Mandsberg, Nikolaj; Taboryski, Rafael

    2016-01-01

    We discuss the influence of surface structure, namely the height and opening angles of nano- and microcones on the surface wettability. We show experimental evidence that the opening angle of the cones is the critical parameter on sample superhydrophobicity, namely static contact angles and roll-off angles. The textured surfaces are fabricated on silicon wafers by using a simple one-step method of reactive ion etching at different processing time and gas flow rates. By using hydrophobic coating or hydrophilic surface treatment, we are able to switch the surface wettability from superhydrophilic to superhydrophobic without altering surface structures. In addition, we show examples of polymer replicas (polypropylene and poly(methyl methacrylate) with different wettability, fabricated by injection moulding using templates of the silicon cone-structures. PMID:26892169

  14. The Influence of Structure Heights and Opening Angles of Micro- and Nanocones on the Macroscopic Surface Wetting Properties

    DEFF Research Database (Denmark)

    Sun, Ling; Laustsen, Milan; Mandsberg, Nikolaj

    2016-01-01

    -off angles. The textured surfaces are fabricated on silicon wafers by using a simple one-step method of reactive ion etching at different processing time and gas flow rates. By using hydrophobic coating or hydrophilic surface treatment, we are able to switch the surface wettability from superhydrophilic......We discuss the influence of surface structure, namely the height and opening angles of nano-and microcones on the surface wettability. We show experimental evidence that the opening angle of the cones is the critical parameter on sample superhydrophobicity, namely static contact angles and roll...... to superhydrophobic without altering surface structures. In addition, we show examples of polymer replicas (polypropylene and poly(methyl methacrylate) with different wettability, fabricated by injection moulding using templates of the silicon cone-structures....

  15. Potential of Multitemporal Tandem-X Derived Crop Surface Models for Maize Growth Monitoring

    Science.gov (United States)

    Hütt, C.; Tilly, N.; Schiedung, H.; Bareth, G.

    2016-06-01

    In this study, first results of retrieving plant heights of maize fields from multitemporal TanDEM-X images are shown. Three TanDEM-X dual polarization spotlight acquisitions were taken over a rural area in Germany in the growing season 2014. By interferometric processing, digital terrain models (DTM) were derived for each date with 5m resolution. From the data of the first acquisition (June 1st) taken before planting, a DTM of the bare ground is generated. The data of the following acquisition dates (July 15th, July 26th) are used to establish crop surface models (CSM). A CSM represents the crop surface of a whole field in a high resolution. By subtracting the DTM of the ground from each CSM, the actual plant height is calculated. Within these data sets 30 maize fields in the area of interest could be detected and verified by external land use data. Besides the spaceborne measurements, one of the maize fields was intensively investigated using terrestrial laser scanning (TLS), which was carried out at the same dates as the predicted TanDEM-X acquisitions. Visual inspection of the derived plant heights, and accordance of the individually processed polarisations over the maize fields, demonstrate the feasibility of the proposed method. Unfortunately, the infield variability of the intensively monitored field could not be successfully captured in the TanDEM-X derived plant heights and merely the general trend is visible. Nevertheless, the study shows the potential of the TanDEM-X constellation for maize height monitoring on field level.

  16. Retrieving aerosol height from the oxygen A band: a fast forward operator and sensitivity study concerning spectral resolution, instrumental noise, and surface inhomogeneity

    Science.gov (United States)

    Hollstein, A.; Fischer, J.

    2014-05-01

    Hyperspectral radiance measurements in the oxygen A band are sensitive to the vertical distribution of atmospheric scatterers, which in principle allows the retrieval of aerosol height from future instruments like TROPOMI, OCO2, FLEX, and CarbonSat. Discussed in this paper is a fast and flexible forward operator for the simulation of hyperspectral radiances in the oxygen A band and, based on this scheme, a sensitivity study about the inversion quality of aerosol optical thickness, aerosol mean height, and aerosol type. The forward operator is based on a lookup table with efficient data compression based on principal component analysis. Linear interpolation and computation of partial derivatives is performed in the much smaller space of expansion coefficients rather than wavelength. Thus, this approach is computationally fast and, at the same time, memory efficient. The sensitivity study explores the impact of instrument design on the retrieval of aerosol optical thickness and aerosol height. Considered are signal to noise ratio, spectral resolution, and spectral sampling. Also taken into account are surface inhomogeneities and variations of the aerosol type.

  17. Comparison of Cloud Base Height Derived from a Ground-Based Infrared Cloud Measurement and Two Ceilometers

    Directory of Open Access Journals (Sweden)

    Lei Liu

    2015-01-01

    Full Text Available The cloud base height (CBH derived from the whole-sky infrared cloud-measuring system (WSIRCMS and two ceilometers (Vaisala CL31 and CL51 from November 1, 2011, to June 12, 2012, at the Chinese Meteorological Administration (CMA Beijing Observatory Station are analysed. Significant differences can be found by comparing the measurements of different instruments. More exactly, the cloud occurrence retrieved from CL31 is 3.8% higher than that from CL51, while WSIRCMS data shows 3.6% higher than ceilometers. More than 75.5% of the two ceilometers’ differences are within ±200 m and about 89.5% within ±500 m, while only 30.7% of the differences between WSIRCMS and ceilometers are within ±500 m and about 55.2% within ±1000 m. These differences may be caused by the measurement principles and CBH retrieval algorithm. A combination of a laser ceilometer and an infrared cloud instrument is recommended to improve the capability for determining cloud occurrence and retrieving CBHs.

  18. Sea level height, sea surface temperature, and tuna yields in the Panama bight during El Niño

    Directory of Open Access Journals (Sweden)

    M. J. Pedraza

    2006-01-01

    Full Text Available Between 1988 and 1998, annual tuna landings at Buenaventura (Colombian Pacific are correlated with the sea surface temperature in the central Equatorial Pacific (r=0.78, p<0.05 and the sea level height at Buenaventura (r=0.76, p<0.05 and Balboa (Panama (r=0.79, p<0.05. Seasonal oceanic upwelling is forced by the Panama wind jet, which may favour oceanic fisheries such as tuna. Here we first apply a bivariate correlation method (Pyper and Peterman, 1994 and then a multivariate approach (principal components analysis or PCA to investigate the relationships of these environmental variables with landings. With the first method, we find that landing is best correlated with the sea surface temperature in the Niño 3 region, whereas the other relationships are less clear. In contrast, with PCA we find that PC1 explains 90.6% of the total variance and suggests that sea surface temperature plays a major role in determining tuna availability in the area (especially during El Niño events. Since PC2 is mainly correlated with sea level height at Balboa but only represents 6.8% of the total variance, we suggest that oceanic upwelling effects on tuna landings at Buenaventura are not significant at interannual scales.

  19. Application of Displacement Height and Surface Roughness Length to Determination Boundary Layer Development Length over Stepped Spillway

    Directory of Open Access Journals (Sweden)

    Xiangju Cheng

    2014-12-01

    Full Text Available One of the most uncertain parameters in stepped spillway design is the length (from the crest of boundary layer development. The normal velocity profiles responding to the steps as bed roughness are investigated in the developing non-aerated flow region. A detailed analysis of the logarithmic vertical velocity profiles on stepped spillways is conducted through experimental data to verify the computational code and numerical experiments to expand the data available. To determine development length, the hydraulic roughness and displacement thickness, along with the shear velocity, are needed. This includes determining displacement height d and surface roughness length z0 and the relationship of d and z0 to the step geometry. The results show that the hydraulic roughness height ks is the primary factor on which d and z0 depend. In different step height, step width, discharge and intake Froude number, the relations d/ks = 0.22–0.27, z0/ks = 0.06–0.1 and d/z0 = 2.2–4 result in a good estimate. Using the computational code and numerical experiments, air inception will occur over stepped spillway flow as long as the Bauer-defined boundary layer thickness is between 0.72 and 0.79.

  20. Estimating Tree Height and Diameter at Breast Height (DBH from Digital Surface Models and Orthophotos Obtained with an Unmanned Aerial System for a Japanese Cypress (Chamaecyparis obtusa Forest

    Directory of Open Access Journals (Sweden)

    Kotaro Iizuka

    2017-12-01

    Full Text Available Methods for accurately measuring biophysical parameters are a key component for quantitative evaluation regarding to various forest applications. Conventional in situ measurements of these parameters take time and expense, encountering difficultness at locations with heterogeneous microtopography. To obtain precise biophysical data in such situations, we deployed an unmanned aerial system (UAS multirotor drone in a cypress forest in a mountainous area of Japan. The structure from motion (SfM method was used to construct a three-dimensional (3D model of the forest (tree structures from aerial photos. Tree height was estimated from the 3D model and compared to in situ ground data. We also analyzed the relationships between a biophysical parameter, diameter at breast height (DBH, of individual trees with canopy width and area measured from orthorectified images. Despite the constraints of ground exposure in a highly dense forest area, tree height was estimated at an accuracy of root mean square error = 1.712 m for observed tree heights ranging from 16 to 24 m. DBH was highly correlated with canopy width (R2 = 0.7786 and canopy area (R2 = 0.7923, where DBH ranged from 11 to 58 cm. The results of estimating forest parameters indicate that drone-based remote-sensing methods can be utilized to accurately analyze the spatial extent of forest structures.

  1. 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

    adopted standards and methodology. This procedure will allow bringing all included stations into one and the same height datum. In sparsely surveyed regions of our planet the uncertainty of height off-sets may be at the level of 20 to 40cm (with extreme values up to 1m). In coastal regions, applying ocean levelling, these numbers may be improved. Ocean levelling is the combination of a "best" ocean topography model with either an altimetric mean sea surface or, at tide gauges, mean sea level as derived from a combination of tide gauge recording and GNSS positioning. The classical geoid definition and realization is operational at the level of a decimeter but poses significant theoretical and operational challenges at the sub-decimetre level.

  2. Slow and Steady: Ocean Circulation. The Influence of Sea Surface Height on Ocean Currents

    Science.gov (United States)

    Haekkinen, Sirpa

    2000-01-01

    The study of ocean circulation is vital to understanding how our climate works. The movement of the ocean is closely linked to the progression of atmospheric motion. Winds close to sea level add momentum to ocean surface currents. At the same time, heat that is stored and transported by the ocean warms the atmosphere above and alters air pressure distribution. Therefore, any attempt to model climate variation accurately must include reliable calculations of ocean circulation. Unlike movement of the atmosphere, movement of the ocean's waters takes place mostly near the surface. The major patterns of surface circulation form gigantic circular cells known as gyres. They are categorized according to their general location-equatorial, subtropical, subpolar, and polar-and may run across an entire ocean. The smaller-scale cell of ocean circulation is known' as an eddy. Eddies are much more common than gyres and much more difficult to track in computer simulations of ocean currents.

  3. STEREO DERIVED CLOUD TOP HEIGHT CLIMATOLOGY OVER GREENLAND FROM 20 YEARS OF THE ALONG TRACK SCANNING RADIOMETER (ATSR INSTRUMENTS

    Directory of Open Access Journals (Sweden)

    D. Fisher

    2012-07-01

    Full Text Available Current algorithms for the determination of cloud top height and cloud fraction in Polar Regions tend to provide unreliable results, particularly in the presence of isothermal conditions within the atmosphere. Alternative methods to determine cloud top heights in such regions effectively, from space borne sensors, are currently limited to stereo-photogrammetry and active sensing methods, such as LiDAR. Here we apply the modified census transform to one month of AATSR stereo data from June 2008. AATSR is unique in that it is the only space borne stereo capable instrument providing data continuously in both the visible, near infrared and thermal channels. This allows for year round imaging of the poles and therefore year round cloud top height and cloud fraction estimation. We attempt a preliminary validation of the stereo retrieved cloud top height measurements from AATSR against collocated cloud height measurements from the CALIOP LiDAR instrument. CALIOP provides an excellent validation tool due to its excellent height resolution of between 30-60 meters. In this validation, a pair of collocated swaths is assessed with a total of 154 inter-comparisons; the results show that AATSR correlates well with CALIOP cloud base layers with an R2 score of 0.71. However, in all cases AATSR appears to be underestimating the cloud top height compared to CALIOP, the causes for this are currently not fully understood and more extensive inter-comparisons are required. Once validation is completed a processing chain is in place to process the entire ATSR time-series data generating a 20 year cloud top height dataset for Greenland.

  4. 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.

  5. Continuous measurements of water surface height and width along a 6.5km river reach for discharge algorithm development

    Science.gov (United States)

    Tuozzolo, S.; Durand, M. T.; Pavelsky, T.; Pentecost, J.

    2015-12-01

    The upcoming Surface Water and Ocean Topography (SWOT) satellite will provide measurements of river width and water surface elevation and slope along continuous swaths of world rivers. Understanding water surface slope and width dynamics in river reaches is important for both developing and validating discharge algorithms to be used on future SWOT data. We collected water surface elevation and river width data along a 6.5km stretch of the Olentangy River in Columbus, Ohio from October to December 2014. Continuous measurements of water surface height were supplemented with periodical river width measurements at twenty sites along the study reach. The water surface slope of the entire reach ranged from during 41.58 cm/km at baseflow to 45.31 cm/km after a storm event. The study reach was also broken into sub-reaches roughly 1km in length to study smaller scale slope dynamics. The furthest upstream sub-reaches are characterized by free-flowing riffle-pool sequences, while the furthest downstream sub-reaches were directly affected by two low-head dams. In the sub-reaches immediately upstream of each dam, baseflow slope is as low as 2 cm/km, while the furthest upstream free-flowing sub-reach has a baseflow slope of 100 cm/km. During high flow events the backwater effect of the dams was observed to propagate upstream: sub-reaches impounded by the dams had increased water surface slopes, while free flowing sub-reaches had decreased water surface slopes. During the largest observed flow event, a stage change of 0.40 m affected sub-reach slopes by as much as 30 cm/km. Further analysis will examine height-width relationships within the study reach and relate cross-sectional flow area to river stage. These relationships can be used in conjunction with slope data to estimate discharge using a modified Manning's equation, and are a core component of discharge algorithms being developed for the SWOT mission.

  6. Joint statistical correction of clutters, spokes and beam height for a radar derived precipitation climatology in southern Germany

    Science.gov (United States)

    Wagner, A.; Seltmann, J.; Kunstmann, H.

    2012-11-01

    First results of radar derived climatology have emerged over the last years, as datasets of appropriate extent are becoming available. Usually, these statistics are based on time series lasting up to ten years as continuous storage of radar data was often not achieved before. This kind of climatology demands a high level of data quality. Small deviations or minor systematic under- or overestimations in single radar images become a major cause of error in statistical analysis. Extensive corrections of radar data are a crucial prerequisite for radar derived climatology. We present a new statistical post-correction scheme based on a climatological analysis of seven years of radar data of the Munich weather radar (2000-2006) operated by DWD (German Weather Service). Original radar products are used subject only to corrections within the signal processor without any further corrections on single radar images. The aim of this statistical correction is to make up for the average systematic errors caused by clutter, propagation, or measuring effects but to conserve small-scale natural variations in space. The statistical correction is based on a thorough analysis of the different causes of possible errors for the Munich weather radar. This analysis revealed the following basic effects: the decrease of rain amount as a function of height and distance from the radar, clutter effects such as clutter remnants after filtering, holes by eliminated clutter or shading effects from obstacles near the radar, visible as spokes, as well as the influence of the bright band. The correction algorithm is correspondingly based on these results. It consists of three modules. The first one is an altitude correction which minimises measuring effects. The second module corrects clutter effects and disturbances and the third one realises a mean adjustment to selected rain gauges. Two different sets of radar products are used. The statistical analysis as well as module 1 and module 2 of the

  7. Mississippi River and Sea Surface Height Effects on Oil Slick Migration

    Science.gov (United States)

    Falcini, Frederico; Jerolmack, Douglas J.; Buongiorno Nardelli, Bruno

    2012-01-01

    Millions of barrels of oil escaped into the Gulf of Mexico (GoM) after the 20 April, 2010 explosion of Deepwater Horizon (DH). Ocean circulation models were used to forecast oil slick migration in the GoM, however such models do not explicitly treat the effects of secondary eddy-slopes or Mississippi River (MR) hydrodynamics. Here we report oil front migration that appears to be driven by sea surface level (SSL) slopes, and identify a previously unreported effect of the MR plume: under conditions of relatively high river discharge and weak winds, a freshwater mound can form around the MR Delta. We performed temporal oil slick position and altimeter analysis, employing both interpolated altimetry data and along-track measurements for coastal applications. The observed freshwater mound appears to have pushed the DH oil slick seaward from the Delta coastline. We provide a physical mechanism for this novel effect of the MR, using a two-layer pressure-driven flow model. Results show how SSL variations can drive a cross-slope migration of surface oil slicks that may reach velocities of order km/day, and confirm a lag time of order 5–10 days between mound formation and slick migration, as observed form the satellite analysis. Incorporating these effects into more complex ocean models will improve forecasts of slick migration for future spills. More generally, large SSL variations at the MR mouth may also affect the dispersal of freshwater, nutrients and sediment associated with the MR plume. PMID:22558317

  8. Influence of vegetation structure on lidar-derived canopy height and fractional cover in forested riparian buffers during leaf-off and leaf-on conditions.

    Science.gov (United States)

    Wasser, Leah; Day, Rick; Chasmer, Laura; Taylor, Alan

    2013-01-01

    Estimates of canopy height (H) and fractional canopy cover (FC) derived from lidar data collected during leaf-on and leaf-off conditions are compared with field measurements from 80 forested riparian buffer plots. The purpose is to determine if existing lidar data flown in leaf-off conditions for applications such as terrain mapping can effectively estimate forested riparian buffer H and FC within a range of riparian vegetation types. Results illustrate that: 1) leaf-off and leaf-on lidar percentile estimates are similar to measured heights in all plots except those dominated by deciduous compound-leaved trees where lidar underestimates H during leaf off periods; 2) canopy height models (CHMs) underestimate H by a larger margin compared to percentile methods and are influenced by vegetation type (conifer needle, deciduous simple leaf or deciduous compound leaf) and canopy height variability, 3) lidar estimates of FC are within 10% of plot measurements during leaf-on periods, but are underestimated during leaf-off periods except in mixed and conifer plots; and 4) depth of laser pulse penetration lower in the canopy is more variable compared to top of the canopy penetration which may influence within canopy vegetation structure estimates. This study demonstrates that leaf-off lidar data can be used to estimate forested riparian buffer canopy height within diverse vegetation conditions and fractional canopy cover within mixed and conifer forests when leaf-on lidar data are not available.

  9. Effect of roughness lengths on surface energy and the planetary boundary layer height over high-altitude Ngoring Lake

    Science.gov (United States)

    Li, Zhaoguo; Lyu, Shihua; Wen, Lijuan; Zhao, Lin; Meng, Xianhong; Ao, Yinhuan

    2017-08-01

    The special climate environment creates a distinctive air-lake interaction characteristic in the Tibetan Plateau (TP) lakes, where the variations of surface roughness lengths also differ somewhat from those of other regions. However, how different categories of roughness lengths affect the lake surface energy exchange and the planetary boundary layer height (PBLH) remains unclear in the TP lakes. In this study, we used a tuned Weather Research and Forecasting (WRF) model version 3.6.1 to investigate the responses of the freeze-up date, turbulent fluxes, meteorological variables, and PBLH to surface roughness length variations in Ngoring Lake. Of all meteorological variables, the lake surface temperature responded to roughness length variations most sensitively; increasing roughness lengths can put the lake freeze-up date forward. The effect of momentum roughness length on wind speed was significantly affected by the fetch length. The increase in the roughness length for heat can induce the increment of the nightly PBLH in most months, especially for the central lake area in autumn. The primary factors that contribute to sensible heat flux (H) and latent heat flux (LE) were the roughness lengths for heat and momentum during the ice-free period, respectively. Increasing roughness length for heat can increase the nightly PBLH, and decreasing roughness length for moisture can also promote growth of the PBLH, but there was no obvious correlation between the momentum roughness length and the PBLH.

  10. Expected Performance of the Upcoming Surface Water and Ocean Topography Mission Measurements of River Height, Width, and Slope

    Science.gov (United States)

    Wei, R.; Frasson, R. P. M.; Williams, B. A.; Rodriguez, E.; Pavelsky, T.; Altenau, E. H.; Durand, M. T.

    2017-12-01

    The upcoming Surface Water and Ocean Topography (SWOT) mission will measure river widths and water surface elevations of rivers wider than 100 m. In preparation for the SWOT mission, the Jet Propulsion Laboratory built the SWOT hydrology simulator with the intent of generating synthetic SWOT overpasses over rivers with realistic error characteristics. These synthetic overpasses can be used to guide the design of processing methods and data products, as well as develop data assimilation techniques that will incorporate the future SWOT data into hydraulic and hydrologic models as soon as the satellite becomes operational. SWOT simulator uses as inputs water depth, river bathymetry, and the surrounding terrain digital elevation model to create simulated interferograms of the study area. Next, the simulator emulates the anticipated processing of SWOT data by attempting to geolocate and classify the radar returns. The resulting cloud of points include information on water surface elevation, pixel area, and surface classification (land vs water). Finally, we process the pixel clouds by grouping pixels into equally spaced nodes located at the river centerline. This study applies the SWOT simulator to six different rivers: Sacramento River, Tanana River, Saint Lawrence River, Platte River, Po River, and Amazon River. This collection of rivers covers a range of size, slope, and planform complexity with the intent of evaluating the impact of river width, slope, planform complexity, and surrounding topography on the anticipated SWOT height, width, and slope error characteristics.

  11. Mississippi River and sea surface height effects on oil slick migration.

    Directory of Open Access Journals (Sweden)

    Frederico Falcini

    Full Text Available Millions of barrels of oil escaped into the Gulf of Mexico (GoM after the 20 April, 2010 explosion of Deepwater Horizon (DH. Ocean circulation models were used to forecast oil slick migration in the GoM, however such models do not explicitly treat the effects of secondary eddy-slopes or Mississippi River (MR hydrodynamics. Here we report oil front migration that appears to be driven by sea surface level (SSL slopes, and identify a previously unreported effect of the MR plume: under conditions of relatively high river discharge and weak winds, a freshwater mound can form around the MR Delta. We performed temporal oil slick position and altimeter analysis, employing both interpolated altimetry data and along-track measurements for coastal applications. The observed freshwater mound appears to have pushed the DH oil slick seaward from the Delta coastline. We provide a physical mechanism for this novel effect of the MR, using a two-layer pressure-driven flow model. Results show how SSL variations can drive a cross-slope migration of surface oil slicks that may reach velocities of order km/day, and confirm a lag time of order 5-10 days between mound formation and slick migration, as observed form the satellite analysis. Incorporating these effects into more complex ocean models will improve forecasts of slick migration for future spills. More generally, large SSL variations at the MR mouth may also affect the dispersal of freshwater, nutrients and sediment associated with the MR plume.

  12. Comparison of BMI Derived from Parent-Reported Height and Weight with Measured Values: Results from the German KiGGS Study

    Directory of Open Access Journals (Sweden)

    Angelika Schaffrath Rosario

    2012-02-01

    Full Text Available The use of parent-reported height and weight is a cost-efficient instrument to assess the prevalence of children’s weight status in large-scale surveys. This study aimed to examine the accuracy of BMI derived from parent-reported height and weight and to identify potential predictors of the validity of BMI derived from parent-reported data. A subsample of children aged 2–17 years (n = 9,187 was taken from the 2003–2006 cross-sectional German KiGGS study. Parent-reported and measured height and weight were collected and BMI was calculated. Besides descriptive analysis, linear regression models with BMI difference and logistic regression models with weight status misclassification as dependent variables were calculated. Height differences varied by gender and were generally small. Weight and BMI were under-reported in all age groups, the under-reporting getting stronger with increasing age. Overall, the proportion for overweight and obesity based on parental and measured reports differed slightly. In the youngest age group, the proportion of overweight children was overestimated, while it was underestimated for older children and adolescents. Main predictors of the difference between parent reported and measured values were age, gender, weight status and parents’ perception of the child’s weight. In summary, the exclusive use of uncorrected parental reports for assessment of prevalence rates of weight status is not recommended.

  13. DMSA scan nomograms for renal length and area: Related to patient age and to body weight, height or surface area

    International Nuclear Information System (INIS)

    Hassan, I.M.; Que, L.; Rutland, M.D.

    2002-01-01

    Aim: To create nomograms for renal size as measured from DMSA renal studies, and to test the nomograms for their ability to separate normal from abnormal kidneys. Method: Renal length was measured from posterior oblique views and renal area from posterior views. Results from 253 patients with bilateral normal kidneys were used to create nomograms for renal size relative to patient age, body height, weight or body surface area (BSA). The nomograms enclosed 95% of the normal kidneys, thus indicating the range for 95% confidence limits, and hence the specificity. Each nomogram was then tested against 46 hypertrophied kidneys and 46 damaged kidneys. Results: The results from nomograms of renal length and renal area, compared to age, body height, body weight and BSA are presented. For each nomogram, the range is presented as a fraction of the mean value, and the number of abnormal kidneys (hypertrophied or damaged) outside the normal range is presented as a percentage (indicating the sensitivity). Conclusion: Renal Area was no better than renal length for detecting abnormal kidneys. Patient age was the least useful method of normalisation. BSA normalisation produced the best results most frequently (narrower ranges and highest detection of abnormal kidneys)

  14. Validity of Proxy-Reported Height and Weight to Derive Body Mass Index in Adults Participating in Special Olympics

    Science.gov (United States)

    Dobranowski, Kristin; Lloyd, Meghann; Côté, Pierre; Balogh, Robert

    2018-01-01

    Background: Overweight and obesity are common in adults with intellectual disabilities, which complicates their health. To meet their health needs, individuals with intellectual disability frequently rely on proxies to answer questions on their behalf. In the general population, the use of proxy-reported height and weight to compute body mass…

  15. Impact of Assimilating Surface Velocity Observations on the Model Sea Surface Height Using the NCOM-4DVAR

    Science.gov (United States)

    2016-09-26

    surface velocity observations available in 15-min intervals for each drifter. The observations are given an error standard deviation value of 0.02m s21... Standard Form 298 (Rev. 8/98) REPORT DOCUMENTATION PAGE Prescribed by ANSI Std. Z39.18 Form Approved OMB No. 0704-0188 The public reporting... statistical analysis is done by not only examining the SSH forecast error across the entire do- main, but also by concentrating on the areamost densely covered

  16. Photoresponsive cellulose fibers by surface modification with multifunctional cellulose derivatives.

    Science.gov (United States)

    Grigoray, Olga; Wondraczek, Holger; Heikkilä, Elina; Fardim, Pedro; Heinze, Thomas

    2014-10-13

    Eucalyptus bleached kraft pulp fibers were modified by adsorption of novel bio-based multifunctional cellulose derivatives in order to generate light responsive surfaces. The cellulose derivatives used were decorated with both cationic groups (degree of substitution, DS of 0.34) and photoactive groups (DS of 0.11 and 0.37). The adsorption was studied by UV-vis spectroscopy, surface plasmon resonance (SPR) and time-of-flight secondary ion mass spectroscopy (ToF-SIMS). The adsorption isotherms followed the Freundlich model and it turned out that the main driving force for the adsorption was electrostatic interaction. Moreover, strong indications for hydrophobic interactions between the fibers and the derivatives and the derivatives themselves were found. ToF-SIMS imaging revealed an even distribution of the derivatives on the fiber surfaces. The modified fibers underwent fast photocrosslinking under UV-irradiation as demonstrated by light absorbance and fluorescence measurements. Thus, our results proved that the modified fibers exhibited light-responsive properties and can potentially be used for the manufacture of smart bio-based materials. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Unmanned aircraft system-derived crop height and normalized difference vegetation index metrics for sorghum yield and aphid stress assessment

    Science.gov (United States)

    Stanton, Carly; Starek, Michael J.; Elliott, Norman; Brewer, Michael; Maeda, Murilo M.; Chu, Tianxing

    2017-04-01

    A small, fixed-wing unmanned aircraft system (UAS) was used to survey a replicated small plot field experiment designed to estimate sorghum damage caused by an invasive aphid. Plant stress varied among 40 plots through manipulation of aphid densities. Equipped with a consumer-grade near-infrared camera, the UAS was flown on a recurring basis over the growing season. The raw imagery was processed using structure-from-motion to generate normalized difference vegetation index (NDVI) maps of the fields and three-dimensional point clouds. NDVI and plant height metrics were averaged on a per plot basis and evaluated for their ability to identify aphid-induced plant stress. Experimental soil signal filtering was performed on both metrics, and a method filtering low near-infrared values before NDVI calculation was found to be the most effective. UAS NDVI was compared with NDVI from sensors onboard a manned aircraft and a tractor. The correlation results showed dependence on the growth stage. Plot averages of NDVI and canopy height values were compared with per-plot yield at 14% moisture and aphid density. The UAS measures of plant height and NDVI were correlated to plot averages of yield and insect density. Negative correlations between aphid density and NDVI were seen near the end of the season in the most damaged crops.

  18. [Particle numbers in classified sizes of roadside dust caused by studded tires in the air at different heights from the pavement surface].

    Science.gov (United States)

    Sato, T; Niioka, T; Kurasaki, M; Kojima, Y

    1996-07-01

    Increased use of motor vehicles has produced various risks to human health due to air pollution by noxious gases, heavy metals and roadside dust. Since the late 1970s, the wide spread use of studded tires for cars has caused pavement wear, resulting in not only economic losses, but also roadside air pollution in cold and snowy regions in Japan. The most serious environmental problem in Sapporo, a city with heavy snowfall, in the 1980s, was roadside dust derived from studded tires. The inhabitants suffered from this dust in the early winter and in the early spring when the streets were not covered with snow. To investigate the influence of such roadside dust upon human health, particle numbers in classified sizes of roadside dust were counted after the roadside dust in the air was collected with a device we constructed at 30, 60, 90, 120, 150, and 180 cm above the pavement surface. The results indicated that the concentration of roadside dust in the air did not greatly vary according to the height from the pavement surface. The results also suggested that xenogranuloma, reported in lungs of stray dogs, under roadside dust-pollution conditions such as those examined here, may occur in humans in the future.

  19. 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.

  20. THE HEIGHT EVOLUTION OF THE ''TRUE'' CORONAL MASS EJECTION MASS DERIVED FROM STEREO COR1 AND COR2 OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Bein, B. M.; Temmer, M.; Veronig, A. M.; Utz, D. [Kanzelhoehe Observatory-IGAM, Institute of Physics, University of Graz, Universitaetsplatz 5, A-8010 Graz (Austria); Vourlidas, A. [Space Science Division, Naval Research Laboratory, Washington, DC (United States)

    2013-05-01

    Using combined STEREO-A and STEREO-B EUVI, COR1, and COR2 data, we derive deprojected coronal mass ejection (CME) kinematics and CME ''true'' mass evolutions for a sample of 25 events that occurred during 2007 December to 2011 April. We develop a fitting function to describe the CME mass evolution with height. The function considers both the effect of the coronagraph occulter, at the beginning of the CME evolution, and an actual mass increase. The latter becomes important at about 10-15 R{sub Sun} and is assumed to mostly contribute up to 20 R{sub Sun }. The mass increase ranges from 2% to 6% per R{sub Sun} and is positively correlated to the total CME mass. Due to the combination of COR1 and COR2 mass measurements, we are able to estimate the ''true'' mass value for very low coronal heights (<3 R{sub Sun }). Based on the deprojected CME kinematics and initial ejected masses, we derive the kinetic energies and propelling forces acting on the CME in the low corona (<3 R{sub Sun }). The derived CME kinetic energies range between 1.0-66 Multiplication-Sign 10{sup 23} J, and the forces range between 2.2-510 Multiplication-Sign 10{sup 14} N.

  1. Longitudinal changes in transtibial amputee gait characteristics when negotiating a change in surface height during continuous gait.

    Science.gov (United States)

    Barnett, C T; Polman, R C J; Vanicek, N

    2014-08-01

    Negotiating a raised surface during continuous gait is an important activity of daily living and is a potentially hazardous task with regards to trips, falls and fall-related injury. However, it is not known how recent transtibial amputees adapt to performing stepping gait tasks in the 6-month period following discharge from rehabilitation. Recent transtibial amputees performed continuous gait trials, stepping onto and from a raised surface walkway representing the height of a street kerb, whilst kinematic and kinetic data were recorded at one, three and six months post-discharge from rehabilitation. Walking speed increased when stepping down (p=0.04) and was invariant across the study period when stepping up. At one month post-discharge, participants displayed an affected lead limb preference (90.8%) when stepping down and an intact lead limb preference (70.0%) when stepping up, although these lead limb preferences diminished over time. Participants spent more time in stance on the intact limb compared to the affected limb in both stepping down (trail limb) (p=0.01) and stepping up (lead and trail limbs) (p=0.05). Participants displayed significantly greater joint mobility and power bursts in the intact trail limb when stepping down and in the intact lead limb when stepping up. Transtibial amputees prefer to exploit intact limb function to a greater extent, although over time, the means by which this occurs changes which affects the initial lead limb preferences. The results from the current study enable future evidence-based therapeutic and prosthetic interventions to be designed that improve transtibial amputee stepping gait. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Mixing height over water and its role on the correlation between temperature and humidity fluctuations in the unstable surface layer

    DEFF Research Database (Denmark)

    Sempreviva, A.M.; Gryning, Sven-Erik

    2000-01-01

    Results from an experimental investigation of the mixing height over inner Danish waters carried out from September 1990 to October 1992, are discussed. The statistical analysis of the mixed-layer height (z(i)) over the sea does not exhibit the daily variation that is characteristic of the mixed ...

  3. 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

  4. Investigation of the mixing layer height derived from ceilometer measurements in the Kathmandu Valley and implications for local air quality

    Directory of Open Access Journals (Sweden)

    A. Mues

    2017-07-01

    Full Text Available In this study 1 year of ceilometer measurements taken in the Kathmandu Valley, Nepal, in the framework of the SusKat project (A Sustainable Atmosphere for the Kathmandu Valley were analysed to investigate the diurnal variation of the mixing layer height (MLH and its dependency on the meteorological conditions. In addition, the impact of the MLH on the temporal variation and the magnitude of the measured black carbon concentrations are analysed for each season. Based on the assumption that black carbon aerosols are vertically well mixed within the mixing layer and the finding that the mixing layer varies only little during night time and morning hours, black carbon emission fluxes are estimated for these hours and per month. Even though this method is relatively simple, it can give an observationally based first estimate of the black carbon emissions in this region, especially illuminating the seasonal cycle of the emission fluxes. The monthly minimum median MLH values typically range between 150 and 200 m during night and early morning hours, the monthly maximum median values between 625 m in July and 1460 m in March. Seasonal differences are not only found in the absolute MLHs, but also in the duration of the typical daytime maximum ranging between 2 and 3 h in January and 6–7 h in May. During the monsoon season a diurnal cycle has been observed with the smallest amplitude (typically between 400 and 500 m, with the lowest daytime mixing height of all seasons (maximum monthly median values typically between 600 and 800 m, and also the highest night-time and early morning mixing height of all seasons (minimum monthly median values typically between 200 and 220 m. These characteristics can mainly be explained with the frequently present clouds and the associated reduction in incoming solar radiation and outgoing longwave radiation. In general, the black carbon concentrations show a clear anticorrelation with MLH measurements

  5. 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)

  6. Surface functionalization of detonation nanodiamonds by phosphonic dichloride derivatives.

    Science.gov (United States)

    Presti, Charlene; Alauzun, Johan G; Laurencin, Danielle; Mutin, P Hubert

    2014-08-05

    A new method for the functionalization of detonation nanodiamonds (DNDs) is proposed, on the basis of surface modification with phosphonic dichloride derivatives. DNDs were first modified by phenylphosphonic dichloride, and the grafting modes and hydrolytic stability under neutral conditions were investigated using (1)H, (13)C, and (31)P solid state NMR spectroscopy, Fourier transform infrared spectroscopy, as well as elemental analysis. Then, in order to illustrate the possibilities offered by this method, DNDs functionalized by mesityl imidazolium groups were obtained by postmodification of DNDs modified by 12-bromododecylphosphonic dichloride. The oxidative thermal stability of the functionalized DNDs was investigated using thermogravimetric analysis.

  7. Navicula height

    DEFF Research Database (Denmark)

    Rathleff, Michael Skovdal; Nielsen, Rasmus Gottschalk N; Olesen, Christian Gammelgaard

    position and relaxed standing posture. Excessive movement of the navicula is considered a predisposing factor in the development of shin splits. No single direct static measurement of navicula height has yet shown to predict a high degree of mid foot movement. The purpose of this study was to investigate......, it was hypothesized that the single leg standing also would be an indicator of navicula drop, and the minimal height of tuberositas navicula during walking. Another test was suggested by Brody, it was named Navicula Drop Test (NDT) and was defined as the difference of navicula height with subtalar joint in neutral...... the relationship between static measurements, using Navicual Drop Test and One Leg Standing (OLS) and the dynamic measurements of minimal navicula height loaded (NHL) and navicula drop (ΔNH)...

  8. Estimating Biomass of Barley Using Crop Surface Models (CSMs Derived from UAV-Based RGB Imaging

    Directory of Open Access Journals (Sweden)

    Juliane Bendig

    2014-10-01

    Full Text Available Crop monitoring is important in precision agriculture. Estimating above-ground biomass helps to monitor crop vitality and to predict yield. In this study, we estimated fresh and dry biomass on a summer barley test site with 18 cultivars and two nitrogen (N-treatments using the plant height (PH from crop surface models (CSMs. The super-high resolution, multi-temporal (1 cm/pixel CSMs were derived from red, green, blue (RGB images captured from a small unmanned aerial vehicle (UAV. Comparison with PH reference measurements yielded an R2 of 0.92. The test site with different cultivars and treatments was monitored during “Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie” (BBCH Stages 24–89. A high correlation was found between PH from CSMs and fresh biomass (R2 = 0.81 and dry biomass (R2 = 0.82. Five models for above-ground fresh and dry biomass estimation were tested by cross-validation. Modelling biomass between different N-treatments for fresh biomass produced the best results (R2 = 0.71. The main limitation was the influence of lodging cultivars in the later growth stages, producing irregular plant heights. The method has potential for future application by non-professionals, i.e., farmers.

  9. Regional surface fluxes from satellite-derived surface temperatures (AVHRR) and radiosonde profiles

    Science.gov (United States)

    Brutsaert, Wilfried; Sugita, Michiaki

    1992-01-01

    Radiometric surface temperatures, derived from measurements by the AVHRR instrument aboard the NOAA-9 and the NOAA-11 polar orbiting satellites, were used in combination with wind velocity and temperature profiles measured by radiosondes, to calculate surface fluxes of sensible heat. The measurements were made during FIFE, the First ISLSCP (International Satellite Land Surface Climatology Project) Field Experiment, in a hilly tall grass prairie area of northeastern Kansas. The method of calculation was based on turbulent similarity formulations for the atmospheric boundary layer. Good agreement (r = 0.7) was obtained with reference values of sensible heat flux, taken as arithmetric means of measurements with the Bowen ratio method at six ground stations. The values of evaporation (latent heat fluxes), derived from these sensible heat fluxes by means of the energy budget, were also in good agreement (r = 0.94) with the corresponding reference values from the ground stations.

  10. Unexpected Covariant Behavior of the Aegean and Ionian Seas in the Period 1987-2008 by Means of a Nondimensional Sea Surface Height Index

    Science.gov (United States)

    Reale, M.; Salon, S.; Crise, A.; Farneti, R.; Mosetti, R.; Sannino, G.

    2017-10-01

    In this work, we use a set of recent multiyear simulations to develop a simplified sea surface height index (SSH). The index characterizes the dynamics of Ionian upper layer circulation and its links with sea surface height and salinity in the Southern Adriatic and Aegean Seas during the period 1987-2008. The analysis highlights a covariant behavior between Ionian Sea and Aegean Sea associated with a mutual zonal exchange of water masses with different salinity characteristics. Our analysis confirms that the variability observed in the period 1987-2008 in the upper layer circulation of the Ionian was driven by the salinity variability in the Southern Adriatic and Aegean Sea. This study supports and reinforces the hypothesis that two observed BiOS-like reversals reflect the existence of multiple equilibrium states in the Mediterranean Thermohaline circulation in the Eastern Mediterranean and that a complete characterization of observed variability needs to take into account a fully coupled Adriatic-Ionian-Aegean System.

  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. Sensitivity of Turbine-Height Wind Speeds to Parameters in Planetary Boundary-Layer and Surface-Layer Schemes in the Weather Research and Forecasting Model

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ben; Qian, Yun; Berg, Larry K.; Ma, Po-Lun; Wharton, Sonia; Bulaevskaya, Vera; Yan, Huiping; Hou, Zhangshuan; Shaw, William J.

    2016-07-21

    We evaluate the sensitivity of simulated turbine-height winds to 26 parameters applied in a planetary boundary layer (PBL) scheme and a surface layer scheme of the Weather Research and Forecasting (WRF) model over an area of complex terrain during the Columbia Basin Wind Energy Study. An efficient sampling algorithm and a generalized linear model are used to explore the multiple-dimensional parameter space and quantify the parametric sensitivity of modeled turbine-height winds. The results indicate that most of the variability in the ensemble simulations is contributed by parameters related to the dissipation of the turbulence kinetic energy (TKE), Prandtl number, turbulence length scales, surface roughness, and the von Kármán constant. The relative contributions of individual parameters are found to be dependent on both the terrain slope and atmospheric stability. The parameter associated with the TKE dissipation rate is found to be the most important one, and a larger dissipation rate can produce larger hub-height winds. A larger Prandtl number results in weaker nighttime winds. Increasing surface roughness reduces the frequencies of both extremely weak and strong winds, implying a reduction in the variability of the wind speed. All of the above parameters can significantly affect the vertical profiles of wind speed, the altitude of the low-level jet and the magnitude of the wind shear strength. The wind direction is found to be modulated by the same subset of influential parameters. Remainder of abstract is in attachment.

  13. Sensitivity of Turbine-Height Wind Speeds to Parameters in Planetary Boundary-Layer and Surface-Layer Schemes in the Weather Research and Forecasting Model

    Science.gov (United States)

    Yang, Ben; Qian, Yun; Berg, Larry K.; Ma, Po-Lun; Wharton, Sonia; Bulaevskaya, Vera; Yan, Huiping; Hou, Zhangshuan; Shaw, William J.

    2017-01-01

    We evaluate the sensitivity of simulated turbine-height wind speeds to 26 parameters within the Mellor-Yamada-Nakanishi-Niino (MYNN) planetary boundary-layer scheme and MM5 surface-layer scheme of the Weather Research and Forecasting model over an area of complex terrain. An efficient sampling algorithm and generalized linear model are used to explore the multiple-dimensional parameter space and quantify the parametric sensitivity of simulated turbine-height wind speeds. The results indicate that most of the variability in the ensemble simulations is due to parameters related to the dissipation of turbulent kinetic energy (TKE), Prandtl number, turbulent length scales, surface roughness, and the von Kármán constant. The parameter associated with the TKE dissipation rate is found to be most important, and a larger dissipation rate produces larger hub-height wind speeds. A larger Prandtl number results in smaller nighttime wind speeds. Increasing surface roughness reduces the frequencies of both extremely weak and strong airflows, implying a reduction in the variability of wind speed. All of the above parameters significantly affect the vertical profiles of wind speed and the magnitude of wind shear. The relative contributions of individual parameters are found to be dependent on both the terrain slope and atmospheric stability.

  14. Using the ASTER global DEM to derive empirical relationships among triangular facet slope, facet height and slip rates along active normal faults

    Science.gov (United States)

    Tsimi, Christina; Ganas, Athanassios

    2015-04-01

    The advent of global DEMs provided a uniform elevation dataset for studying geomorphic parameters in a variety of settings. In this paper ASTER DEM data (30-m pixel size) are used to derive empirical relationships between triangular facet attributes and slip rates along active normal faults. We sampled 232 triangular facets along 10 normal faults in Greece and Bulgaria that slip with rates from 0.1 mm/yr up to 1.3 mm/yr. The studied normal faults accumulate Quaternary tectonic strain in well-known extensional provinces, such as central Greece, Crete and SW Bulgaria. The normal fault footwalls analyzed herein have been developed under similar long-term climatic conditions. It is suggested that two key geometrical features of the youngest generation of triangular facets (slope angle and height) can provide useful metrics to assess rates of deformation when seismological and geodetic data are lacking or not found in sufficient quantity to make reasonable assessments. Our derived empirical relation between slip rate and facet slope angle is: Y = 0.057 × X - 1 where Y is the fault slip rate (mm/yr) and X is the facet slope angle (degrees), with an R2 = 0.728. It is envisaged that our analysis may be helpful in assessing seismic hazard along normal faults with similar facet characteristics in other extensional settings.

  15. Effect of Channel Orientation and Rib Pitch-to-Height Ratio on Pressure Drop in a Rotating Square Channel with Ribs on Two Opposite Surfaces

    Directory of Open Access Journals (Sweden)

    Prabhu S. V.

    2005-01-01

    Full Text Available The effect of channel orientation and rib pitch-to-height ratio on the pressure drop distribution in a rib-roughened channel is an important issue in turbine blade cooling. The present investigation is a study of the overall pressure drop distribution in a square cross-sectioned channel, with rib turbulators, rotating about an axis normal to the free stream. The ribs are configured in a symmetric arrangement on two opposite surfaces with a rib angle of 90 ∘ to the mainstream flow. The study has been conducted for three Reynolds numbers, namely, 13 000, 17 000, and 22 000 with the rotation number varying from 0– 0.38 . Experiments have been carried out for various rib pitch-to-height ratios ( P/e with a constant rib height-to-hydraulic diameter ratio ( e/D of 0.1 . The test section in which the ribs are placed on the leading and trailing surfaces is considered as the base case ( orientation angle= 0 ∘ , Coriolis force vector normal to the ribbed surfaces. The channel is turned about its axis in steps of 15 ∘ to vary the orientation angle from 0 ∘ to 90 ∘ . The overall pressure drop does not change considerably under conditions of rotation for the base case. However, for the other cases tested, it is observed that the overall pressure drop increases with an increase in the rotation number for a given orientation angle and also increases with an increase in the orientation angle for a given rotation number. This change is attributed to the variation in the separation zone downstream of the ribs due to the presence of the Coriolis force—local pressure drop data is presented which supports this idea. At an orientation angle of 90 ∘ (ribs on the top and bottom surfaces, Coriolis force vector normal to the smooth surfaces, the overall pressure drop is observed to be maximum during rotation. The overall pressure drop for a case with a rib pitch-to-height ratio of 5 on both surfaces is found to be the highest

  16. Polarization optics of the Brewster's dark patch visible on water surfaces versus solar height and sky conditions: theory, computer modeling, photography, and painting.

    Science.gov (United States)

    Takács, Péter; Barta, András; Pye, David; Horváth, Gábor

    2017-10-20

    When the sun is near the horizon, a circular band with approximately vertically polarized skylight is formed at 90° from the sun, and this skylight is only weakly reflected from the region of the water surface around the Brewster's angle (53° from the nadir). Thus, at low solar heights under a clear sky, an extended dark patch is visible on the water surface when one looks toward the north or south quarter perpendicular to the solar vertical. In this work, we study the radiance distribution of this so-called Brewster's dark patch (BDP) in still water as functions of the solar height and sky conditions. We calculate the pattern of reflectivity R of a water surface for a clear sky and obtain from this idealized situation the shape of the BDP. From three full-sky polarimetric pictures taken about a clear, a partly cloudy, and an overcast sky, we determine the R pattern and compose from that synthetic color pictures showing how the radiance distribution of skylight reflected at the water surface and the BDPs would look under these sky conditions. We also present photographs taken without a linearly polarizing filter about the BDP. Finally, we show a 19th century painting on which a river is seen with a dark region of the water surface, which can be interpreted as an artistic illustration of the BDP.

  17. Impact of soil moisture and winter wheat height from the Loess Plateau in Northwest China on surface spectral albedo

    Science.gov (United States)

    Li, Zhenchao; Yang, Jiaxi; Gao, Xiaoqing; Zheng, Zhiyuan; Yu, Ye; Hou, Xuhong; Wei, Zhigang

    2018-02-01

    The understanding of surface spectral radiation and reflected radiation characteristics of different surfaces in different climate zones aids in the interpretation of regional surface energy transfers and the development of land surface models. This study analysed surface spectral radiation variations and corresponding surface albedo characteristics at different wavelengths as well as the relationship between 5-cm soil moisture and surface albedo on typical sunny days during the winter wheat growth period. The analysis was conducted using observational Loess Plateau winter wheat data from 2015. The results show that the ratio of atmospheric downward radiation to global radiation on typical sunny days is highest for near-infrared wavelengths, followed by visible wavelengths and ultraviolet wavelengths, with values of 57.3, 38.7 and 4.0%, respectively. The ratio of reflected spectral radiation to global radiation varies based on land surface type. The visible radiation reflected by vegetated surfaces is far less than that reflected by bare ground, with surface albedos of 0.045 and 0.27, respectively. Thus, vegetated surfaces absorb more visible radiation than bare ground. The atmospheric downward spectral radiation to global radiation diurnal variation ratios vary for near-infrared wavelengths versus visible and ultraviolet wavelengths on typical sunny days. The near-infrared wavelengths ratio is higher in the morning and evening and lower at noon. The visible and ultraviolet wavelengths ratios are lower in the morning and evening and higher at noon. Visible and ultraviolet wavelength surface albedo is affected by 5-cm soil moisture, demonstrating a significant negative correlation. Excluding near-infrared wavelengths, correlations between surface albedo and 5-cm soil moisture pass the 99% confidence test at each wavelength. The correlation with 5-cm soil moisture is more significant at shorter wavelengths. However, this study obtained surface spectral radiation

  18. Lipoxin A4 stimulates calcium-activated chloride currents and increases airway surface liquid height in normal and cystic fibrosis airway epithelia.

    LENUS (Irish Health Repository)

    2012-01-01

    Cystic Fibrosis (CF) is a genetic disease characterised by a deficit in epithelial Cl(-) secretion which in the lung leads to airway dehydration and a reduced Airway Surface Liquid (ASL) height. The endogenous lipoxin LXA(4) is a member of the newly identified eicosanoids playing a key role in ending the inflammatory process. Levels of LXA(4) are reported to be decreased in the airways of patients with CF. We have previously shown that in normal human bronchial epithelial cells, LXA(4) produced a rapid and transient increase in intracellular Ca(2+). We have investigated, the effect of LXA(4) on Cl(-) secretion and the functional consequences on ASL generation in bronchial epithelial cells obtained from CF and non-CF patient biopsies and in bronchial epithelial cell lines. We found that LXA(4) stimulated a rapid intracellular Ca(2+) increase in all of the different CF bronchial epithelial cells tested. In non-CF and CF bronchial epithelia, LXA(4) stimulated whole-cell Cl(-) currents which were inhibited by NPPB (calcium-activated Cl(-) channel inhibitor), BAPTA-AM (chelator of intracellular Ca(2+)) but not by CFTRinh-172 (CFTR inhibitor). We found, using confocal imaging, that LXA(4) increased the ASL height in non-CF and in CF airway bronchial epithelia. The LXA(4) effect on ASL height was sensitive to bumetanide, an inhibitor of transepithelial Cl(-) secretion. The LXA(4) stimulation of intracellular Ca(2+), whole-cell Cl(-) currents, conductances and ASL height were inhibited by Boc-2, a specific antagonist of the ALX\\/FPR2 receptor. Our results provide, for the first time, evidence for a novel role of LXA(4) in the stimulation of intracellular Ca(2+) signalling leading to Ca(2+)-activated Cl(-) secretion and enhanced ASL height in non-CF and CF bronchial epithelia.

  19. A Bayesian inversion framework for yield and height-of-burst/depth-of-burial for near-surface explosions

    Energy Technology Data Exchange (ETDEWEB)

    Johannesson, Gardar [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bulaevskaya, Vera [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ramirez, Abe [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ford, Sean [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rodgers, Artie [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-09-07

    A Bayesian inversion framework is presented to estimate the yield of an explosion and height-of-burst/depth-of-burial (HOB/DOB) using seismic and air pressure data. This is accomplished by first calibrating the parameters in the forward models that relate the observations to the yield and HOB/DOB and then using the calibrated model to estimate yield and HOB/DOB associated with a new set of seismic and air pressure observations. The MCMC algorithms required to perform these steps are outlined, and the results with real data are shown. Finally, an extension is proposed for a case when clustering in the seismic displacement occurs as a function of different types of rock and other factors.

  20. Ultrasound measured testicular volume in Nigerian adults: Relationship of the three formulae with height, body weight, body-surface area, and body-mass index

    Directory of Open Access Journals (Sweden)

    Madubogwu Chimezie Innocent

    2016-01-01

    Full Text Available Background: Measurement of testicular volume is one of the ways of assessing testicular function. Ultrasonography is an important and accurate radiological method for measurement of testicular volume. Objective: This study was aimed at evaluating the relationship of ultrasound measured testicular volume using the three formulae with the subjects' height, body weight, body surface area (BSA, and body mass index (BMI in adults. Methodology: One hundred twenty-five adult male subjects comprising staff and students of a University Teaching Hospital were recruited into the study. Height and body weight were measured while the BMI and BSA were calculated. Ultrasound measurement of the height, length, and width of both testes were done and used to calculate the volumes using the three formulae. Results: The subjects' age ranged from 19 to 29 years with a mean of 23.48 ± 2.26 yrs. The mean ultrasound measured volumes for the right and left testes were 15.38 ± 3.29 ml and 15.29 ± 3.89 ml using the prolate ellipsoid formula; 22.86 ± 5.43 ml and 23.54 ± 6.88 ml by the prolate spheroid formula; 21.20 ± 5.28 ml and 20.87 ± 5.35 ml by the Lambert formula, respectively. The calculated mean for height, body weight, BMI, and BSA were 174.64 ± 6.36 cm, 68.68 ± 8.25 kg, 22.48 ± 2.17 kg/m2, and 1.82 ± 0.13 m2, respectively. The right testes showed a negative correlation, while the left and combined testicular volumes showed a positive correlation with the subjects' height, body weight, BMI, and BSA for all the three formulae. Conclusion: The right testicular volume showed negative correlation, while the left and combined testicular volumes showed a positive correlation with the height, body weight, BSA, and BMI in Nigerian adults.

  1. High yield synthesis of some phosphonic acid derivatives as surface ...

    African Journals Online (AJOL)

    Efficient synthesis of novel 6-(2-bromo-2-methyl propanoyloxy)hexyl phosphonic acid, dodecane di-phosphonic acid, 6-(thiophene-3-carbonyloxy)hexyl phosphonic acid, octadecyl phosphonic acid and such other derivatives are reported here. These derivatives have a potential application as tethers to nanoparticle ...

  2. Variational derivation of KdV-type of models for surface water waves

    NARCIS (Netherlands)

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

    2007-01-01

    Using the Hamiltonian formulation of surface waves, we approximate the kinetic energy and restrict the governing generalized action principle to a submanifold of uni-directional waves. Different from the usual method of using a series expansion in parameters related to wave height and wavelength,

  3. Why Do We Need the Derivative for the Surface Area?

    Science.gov (United States)

    Hristova, Yulia; Zeytuncu, Yunus E.

    2016-01-01

    Surface area and volume computations are the most common applications of integration in calculus books. When computing the surface area of a solid of revolution, students are usually told to use the frustum method instead of the disc method; however, a rigorous explanation is rarely provided. In this note, we provide one by using geometric…

  4. Effect of slope on treetop detection using a LiDAR Canopy Height Model

    NARCIS (Netherlands)

    Khosravipour, A.; Skidmore, A.K.; Wang, Tiejun; Isenburg, M.; Khoshelham, K.

    2015-01-01

    Canopy Height Models (CHMs) or normalized Digital Surface Models (nDSM) derived from LiDAR data have been applied to extract relevant forest inventory information. However, generating a CHM by height normalizing the raw LiDAR points is challenging if trees are located on complex terrain. On steep

  5. Utilizing the NASA and NOAA Joint Ocean Surface Topography Mission to Assess Patterns and Trends in Sea-Surface Height in the U.S. Affiliated Pacific Islands

    Science.gov (United States)

    Fitzgerald, S. S.; Walker, K. A.; Courtright, A. B.; Young, I. J.

    2017-12-01

    The United States Affiliated Pacific Islands (USAPI) are home to a population of low-lying coral atolls which are extremely vulnerable to sea level rise. Coastal infrastructure like groundwater reservoirs, harbor operations, and sewage systems, as well as natural coastal features such as reefs and beach ecosystems, are most vulnerable during inundation events. These Pacific Islanders face increasing hazards as coastal flooding infiltrates freshwater resources and may even lead to displacement. The two main components of inundation include tidal fluctuations and sea level anomalies; however, low-lying atolls are also vulnerable to the additional influence of waves. This study created a climatology of significant wave height in the Republic of the Marshall Islands (RMI), and incorporated this dataset with tides and sea level anomalies to create a novel approach to assessing inundation flood risk in the RMI. The risk metric was applied to the RMI as a study site with the goal of assessing wider-scale applicability across the rest of the USAPI. The inclusion of wave height and wave direction as a crucial component of the risk metric will better inform USAPI coastal-managers for future inundation events and disaster preparedness. In addition to the risk metric, a wave-rose atlas was created for decision-makers in the RMI. This study highlights the often-overlooked region of the Pacific and demonstrates the application of the risk metric to specific examples in the RMI.

  6. The construction of drape surfaces with constrained first derivatives

    Directory of Open Access Journals (Sweden)

    R.J. Fossati

    2014-01-01

    Full Text Available The need to construct optimal drape surfaces arises in airborne geophysical surveys where it is necessary to fly a safe distance above the ground and within the performance of the aircraft used, but as close as possible to the surface. The problem is formulated as an LP with constraints at every point of a grid covering the area concerned, yielding a huge problem. The lifting algorithm is suggested. This is a surprisingly simple algorithm which starts with the drape surface at ground level and lifts it one point at a time. Only points which are too low relative to one or more of their neighbours are considered and they are lifted just enough to bring them into kilter with their neighbours. It is shown that the lifting algorithm is both exact and has great speed advantages. Some numerical results confirming exactness and speed are presented. An enhanced method with better complexity is proposed and tested numerically.

  7. 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

  8. Hydrographic network control of the spatial variation in tropical forest structure revealed by airborne LIDAR-derived mean canopy profile height

    Science.gov (United States)

    Detto, M.; Muller-Landau, H.; Asner, G. P.; Mascaro, J.

    2012-12-01

    Hydrologic flow and connectivity are important determinants of ecological pattern and process. The watershed structure acts as a template for the spatial distribution of vegetation which self-organizes through local stress optimization within the network flow paths of the basin. These influences have long been recognized in riparian vegetation, deserts, savannas or other water-limited ecosystems. Here, we examine their importance in moist tropical forest. In dry ecosystems, water availability plays a crucial role in the spatial and temporal dynamics of vegetation, providing the most logical causal link with the drainage network, while in moist tropical forest this link is less apparent. Remote sensing offers an invaluable tool to start investigating these variations systematically on larger spatial extent. Recent advances in LiDAR techniques have made it possible to monitor forest structure with unprecedented resolution. Unlike other passive remote sensors, the LiDAR has the advantage to penetrate the canopy and give information on the whole profile, hence it is suitable to study heterogeneous dense forests. For example, LiDAR-derived products such as mean canopy height (MCH) are well correlated with carbon stocks in tropical areas. Furthermore, it provides an accurate digital elevation model (DEM) that perfectly matches the vegetation above. In this study we investigate the connection between the drainage network and LIDAR-derived MCH in a moist tropical forest in central Panama. The study area comprises thousands of hectares of mixed old-growth and old secondary forest in a relatively homogeneous geological formation with a very complex network of small streams that discharge into the Gatun Lake. These characteristics make the area ideal for studying the influence of the network on a relatively large area of land without confounding variation in lithological formation, forest type or climate. Our analysis shows important isotropic scale invariant properties of

  9. The topside ionospheric effective scale heights (HT) derived with ROCSAT-1 and ground-based Ionosonde observations at equatorial and mid-latitude stations

    Science.gov (United States)

    Ram Sudarsanam, Tulasi; Su, Shin-Yi; Liu, C. H.; Reinisch, Bodo

    In this study, we propose the assimilation of topside in situ electron density data from ROCSAT-1 satellite along with the ionosonde measurements for accurate determination of topside iono-spheric effective scale heights (HT) using -Chapman function. The reconstructed topside elec-tron density profiles using these scale heights exhibit an excellent similitude with Jicamarca Incoherent Scatter Radar (ISR) profiles, and are much better representations than the existing methods of Reinisch-Huang method and/or the empirical IRI-2007 model. The main advan-tage with this method is that it allows the precise determination of the effective scale height (HT) and the topside electron density profiles at a dense network of ionosonde/digisonde sta-tions where no ISR facilities are available. The demonstration of the method is applied by investigating the diurnal, seasonal and solar activity variations of HT over the dip-equatorial station Jicamarca and the mid-latitude station Grahamstown. The diurnal variation of scale heights over Jicamarca consistently exhibits a morning time descent followed by a minimum around 0700-0800 LT and a pronounced maximum at noon during all the seasons of both high and moderate solar activity periods. Further, the scale heights exhibit a secondary maximum during the post-sunset hours of equinoctial and summer months, whereas the post-sunset peak is absent during the winter months. These typical features are further investigated using the topside ion properties obtained by ROCSAT-1 as well as SAMI2 model simulations. The re-sults consistently indicate that the diurnal variation of the effective scale height (HT) does not closely follow the plasma temperature variation and at equatorial latitudes is largely controlled by the vertical ExB drift.

  10. Northern South China Sea Surface Circulation and its Variability Derived by Combining Satellite Altimetry and Surface Drifter Data

    Directory of Open Access Journals (Sweden)

    N. Peter Benny

    2015-01-01

    Full Text Available The present study analyses the mean and seasonal mesoscale surface circulation of the Northern South China Sea (NSCS and determines the influence of El Niño/SouthernNiño/Southern Oscillation (ENSO. High resolution Eulerian velocity field is derived by combining the available satellite tracked surface drifter data with satellite altimetry during 1993 - 2012. The wind driven current is computed employing the weekly ocean surface mean wind fields derived from the scatterometers on board ERS 1/2, QuikSCAT and ASCAT. The derived mean velocity field exhibits strong boundary currents and broad zonal flow across NSCS. The anomalous field is quite strong in the southern part and the Seasonal circulation clearly depicts the monsoonal forcing. Eddy Kinetic Energy (EKE distribution and its spatial and temporal structures are determined employing Empirical Orthogonal Function (EOF analysis. The ENSO influence on NSCS surface circulation has been analyzed using monthly absolute geostrophic velocity fields during 1996 - 1999.

  11. Deriving the geomagnetically induced electric field at the Earth's surface from the time derivative of the vertical magnetic field

    Science.gov (United States)

    Vanhamäki, Heikki; Viljanen, Ari; Pirjola, Risto; Amm, Olaf

    2013-09-01

    We present a new method for estimating the geomagnetically induced electric field at the Earth's surface directly from the time derivative of the vertical magnetic field, without any need for additional information about the Earth's electric conductivity. This is a simplification compared to the presently used calculation methods, which require both the magnetic variation field and ground conductivity model as input data. The surface electric field is needed e.g. in modeling Geomagnetically Induced Currents (GIC) that flow in man-made conductor systems, such as gas and oil pipelines or high-voltage power grids. We solve the induced electric field directly from Faraday's law, by representing the magnetic variation field in terms of external equivalent current and taking time derivative of the associated vector potential. This gives an approximative solution, where the divergence-free part of the electric field is reproduced accurately (at least in principle), but the curl-free part related to lateral variations in ground conductivity is completely neglected. We test the new calculation method with several realistic models of typical ionospheric current systems, as well as actual data from the Baltic Electromagnetic Array Research (BEAR) network. We conclude that the principle of calculating the (divergence-free part of the) surface electric field from time derivative of the vertical magnetic field is sound, and the method works reasonably well also in practice. However, practical applications may be rather limited as the method seems to require data from a quite dense and spatially extended magnetometer network.

  12. NATO Advanced Research Workshop on Geometrical Derivatives of Energy Surfaces and Molecular Properties

    CERN Document Server

    Simons, Jack

    1986-01-01

    The development and computational implementation of analytical expres­ sions for the low-order derivatives of electronic energy surfaces and other molecular properties has undergone rapid growth in recent years. It is now fairly routine for chemists to make use of energy gradient information in locating and identifying stable geometries and transition states. The use of second analytical derivative (Hessian or curvature) expressions is not yet routine, and third and higher energy derivatives as well as property (e.g., dipole moment, polarizability) derivatives are just beginning to be applied to chemical problems. This NATO Advanced Research Workshop focused on analyzing the re­ lative merits of various strategies for deriving the requisite analyti­ cal expressions, for computing necessary integral derivatives and wave­ function parameter derivatives, and for efficiently coding these expres­ sions on conventional scalar machines and vector-oriented computers. The participant list contained many scientist...

  13. Real-time sensing of enteropathogenic E. coli-induced effects on epithelial host cell height, cell-substrate interactions, and endocytic processes by infrared surface plasmon spectroscopy.

    Directory of Open Access Journals (Sweden)

    Victor Yashunsky

    Full Text Available Enteropathogenic Escherichia coli (EPEC is an important, generally non-invasive, bacterial pathogen that causes diarrhea in humans. The microbe infects mainly the enterocytes of the small intestine. Here we have applied our newly developed infrared surface plasmon resonance (IR-SPR spectroscopy approach to study how EPEC infection affects epithelial host cells. The IR-SPR experiments showed that EPEC infection results in a robust reduction in the refractive index of the infected cells. Assisted by confocal and total internal reflection microscopy, we discovered that the microbe dilates the intercellular gaps and induces the appearance of fluid-phase-filled pinocytic vesicles in the lower basolateral regions of the host epithelial cells. Partial cell detachment from the underlying substratum was also observed. Finally, the waveguide mode observed by our IR-SPR analyses showed that EPEC infection decreases the host cell's height to some extent. Together, these observations reveal novel impacts of the pathogen on the host cell architecture and endocytic functions. We suggest that these changes may induce the infiltration of a watery environment into the host cell, and potentially lead to failure of the epithelium barrier functions. Our findings also indicate the great potential of the label-free IR-SPR approach to study the dynamics of host-pathogen interactions with high spatiotemporal sensitivity.

  14. A Comparison of Simulated and Field-Derived Leaf Area Index (LAI and Canopy Height Values from Four Forest Complexes in the Southeastern USA

    Directory of Open Access Journals (Sweden)

    John S. Iiames

    2018-01-01

    Full Text Available Vegetative leaf area is a critical input to models that simulate human and ecosystem exposure to atmospheric pollutants. Leaf area index (LAI can be measured in the field or numerically simulated, but all contain some inherent uncertainty that is passed to the exposure assessments that use them. LAI estimates for minimally managed or natural forest stands can be particularly difficult to develop as a result of interspecies competition, age and spatial distribution. Satellite-based LAI estimates hold promise for retrospective analyses, but we must continue to rely on numerical models for alternative management analysis. Our objective for this study is to calculate and validate LAI estimates generated from the USDA Environmental Policy Impact Climate (EPIC model (a widely used, field-scale, biogeochemical model on four forest complexes spanning three physiographic provinces in Virginia and North Carolina. Measurements of forest composition (species and number, LAI, tree diameter, basal area, and canopy height were recorded at each site during the 2002 field season. Calibrated EPIC results show stand-level temporally resolved LAI estimates with R2 values ranging from 0.69 to 0.96, and stand maximum height estimates within 20% of observation. This relatively high level of performance is attributable to EPIC’s approach to the characterization of forest stand biogeochemical budgets, stand history, interspecies competition and species-specific response to local weather conditions. We close by illustrating the extension of this site-level approach to scales that could support regional air quality model simulations.

  15. Proposed Lucas Heights tandem accelerator

    International Nuclear Information System (INIS)

    1985-01-01

    An 8 million volt tandem accelerator (LHTA - Lucas Heights Tandem Accelerator) is proposed to be installed at the Australian Atomic Energy Commission's Lucas Heights Research Laboratories. The new facility is expected to cost $6 million and will have applications such as ultrasensitive trace element analysis for management of groundwater resources, salinity in soil, soil erosion and Antarctic research. Applied physics applications include nuclear safeguards, energy sources, study of material surfaces, archaeology, archaeometry and occupational health

  16. FULLY AUTOMATED GIS-BASED INDIVIDUAL TREE CROWN DELINEATION BASED ON CURVATURE VALUES FROM A LIDAR DERIVED CANOPY HEIGHT MODEL IN A CONIFEROUS PLANTATION

    Directory of Open Access Journals (Sweden)

    R. J. L. Argamosa

    2016-06-01

    Full Text Available The generation of high resolution canopy height model (CHM from LiDAR makes it possible to delineate individual tree crown by means of a fully-automated method using the CHM’s curvature through its slope. The local maxima are obtained by taking the maximum raster value in a 3 m x 3 m cell. These values are assumed as tree tops and therefore considered as individual trees. Based on the assumptions, thiessen polygons were generated to serve as buffers for the canopy extent. The negative profile curvature is then measured from the slope of the CHM. The results show that the aggregated points from a negative profile curvature raster provide the most realistic crown shape. The absence of field data regarding tree crown dimensions require accurate visual assessment after the appended delineated tree crown polygon was superimposed to the hill shaded CHM.

  17. Deriving surface soil moisture from reflected GNSS signal observations from a grassland site in southwestern France

    Directory of Open Access Journals (Sweden)

    S. Zhang

    2018-03-01

    Full Text Available This work assesses the estimation of surface volumetric soil moisture (VSM using the global navigation satellite system interferometric reflectometry (GNSS-IR technique. Year-round observations were acquired from a grassland site in southwestern France using an antenna consecutively placed at two contrasting heights above the ground surface (3.3 and 29.4 m. The VSM retrievals are compared with two independent reference datasets: in situ observations of soil moisture, and numerical simulations of soil moisture and vegetation biomass from the ISBA (Interactions between Soil, Biosphere and Atmosphere land surface model. Scaled VSM estimates can be retrieved throughout the year removing vegetation effects by the separation of growth and senescence periods and by the filtering of the GNSS-IR observations that are most affected by vegetation. Antenna height has no significant impact on the quality of VSM estimates. Comparisons between the VSM GNSS-IR retrievals and the in situ VSM observations at a depth of 5 cm show good agreement (R2 =  0.86 and RMSE  =  0.04 m3 m−3. It is shown that the signal is sensitive to the grass litter water content and that this effect triggers differences between VSM retrievals and in situ VSM observations at depths of 1 and 5 cm, especially during light rainfall events.

  18. Deriving surface soil moisture from reflected GNSS signal observations from a grassland site in southwestern France

    Science.gov (United States)

    Zhang, Sibo; Calvet, Jean-Christophe; Darrozes, José; Roussel, Nicolas; Frappart, Frédéric; Bouhours, Gilles

    2018-03-01

    This work assesses the estimation of surface volumetric soil moisture (VSM) using the global navigation satellite system interferometric reflectometry (GNSS-IR) technique. Year-round observations were acquired from a grassland site in southwestern France using an antenna consecutively placed at two contrasting heights above the ground surface (3.3 and 29.4 m). The VSM retrievals are compared with two independent reference datasets: in situ observations of soil moisture, and numerical simulations of soil moisture and vegetation biomass from the ISBA (Interactions between Soil, Biosphere and Atmosphere) land surface model. Scaled VSM estimates can be retrieved throughout the year removing vegetation effects by the separation of growth and senescence periods and by the filtering of the GNSS-IR observations that are most affected by vegetation. Antenna height has no significant impact on the quality of VSM estimates. Comparisons between the VSM GNSS-IR retrievals and the in situ VSM observations at a depth of 5 cm show good agreement (R2 = 0.86 and RMSE = 0.04 m3 m-3). It is shown that the signal is sensitive to the grass litter water content and that this effect triggers differences between VSM retrievals and in situ VSM observations at depths of 1 and 5 cm, especially during light rainfall events.

  19. Thermal inertias in the upper millimeters of the Martian surface derived using Phobos' shadow

    Science.gov (United States)

    Betts, Bruce H.; Murray, Bruce C.; Svitek, Tomas

    1995-01-01

    The first thermal images of Phobos' shadow on the surface of Mars, in addition to simultaneous visible images, were obtained by the Phobos'88 Termoskan instrument. The best observed shadow occurrence was on the flanks of Arsia Mons. For this occurrence, we combined the observed decrease in visible illumination of the surface with the observed decrease in brightness temperature to calculate thermal inertias of the Martian surface. The most realistic of our three models of eclipse cooling improves upon our preliminary model by including nonisothermal initial conditions and downward atmospheric flux. Most of our derived inertias fall within the range 38 to 59 J/(sq m s(exp 1/2) K), (0.9 to 1.4 x 10(exp -3) cal/(sq cm s(exp 1/2) K)) corresponding to dust-sized particles (for a homogeneous surface), consistent with previous theories of Tharsis as a current area of dust deposition. Viking infrared thermal mapper (IRTM) inertias are diurnally derived and are sensitive to centimeter depths, whereas the shadow-derived inertias sample the upper tenths of a millimeter of the surface. The shadow-derived inertias are lower than those derived from Viking IRTM measurements (84 to 147), however, uncertainties in both sets of derived inertias make conclusions about layering tenuous. Thus, near-surface millimeter versus centimeter layering may exist in this region, but if it does, it is likely not very significant. Both eclipse and diurnal inertias appear to increase near the eastern end of the shadow occurrence. We also analyzed a shadow occurrence near the crater Herschel that showed no observed cooling. This analysis was limited by cool morning temperatures and instrument sensitivity, but yielded a lower bound of 80 on eclipse inertias in that region. Based upon our results, we strongly recommend future spacecraft thermal observations of Phobos' shadow, and suggest that they will be most useful if they improve upon Terinoskan's geographic and temporal coverage and its accuracy.

  20. Patterns of the loop current system and regions of sea surface height variability in the eastern Gulf of Mexico revealed by the self-organizing maps

    Science.gov (United States)

    Liu, Yonggang; Weisberg, Robert H.; Vignudelli, Stefano; Mitchum, Gary T.

    2016-04-01

    The Self-Organizing Map (SOM), an unsupervised learning neural network, is employed to extract patterns evinced by the Loop Current (LC) system and to identify regions of sea surface height (SSH) variability in the eastern Gulf of Mexico (GoM) from 23 years (1993-2015) of altimetry data. Spatial patterns are characterized as different LC extensions and different stages in the process of LC eddy shedding. The temporal evolutions and the frequency of occurrences of these patterns are obtained, and the typical trajectories of the LC system progression on the SOM grid are investigated. For an elongated, northwest-extended, or west-positioned LC, it is common for the LC anticyclonic eddy (LCE) to separate and propagate into the western GoM, while an initially separated LCE in close proximity to the west Florida continental slope often reattaches to the LC and develops into an elongated LC, or reduces intensity locally before moving westward as a smaller eddy. Regions of differing SSH variations are also identified using the joint SOM-wavelet analysis. Along the general axis of the LC, SSH exhibits strong variability on time scales of 3 months to 2 years, also with energetic intraseasonal variations, which is consistent with the joint Empirical Orthogonal Function (EOF)-wavelet analysis. In the more peripheral regions, the SSH has a dominant seasonal variation that also projects across the coastal ocean. The SOM, when applied to both space and time domains of the same data, provides a powerful tool for diagnosing ocean processes from such different perspectives.

  1. Intraseasonal-to-semiannual variability of sea-surface height in the astern, equatorial Indian Ocean and southern Bay of Bengal

    Science.gov (United States)

    Cheng, Xuhua; McCreary, Julian P.; Qiu, Bo; Qi, Yiquan; Du, Yan

    2017-05-01

    Intraseasonal-to-semiannual variability of sea-surface height (SSH) in the eastern, equatorial Indian Ocean (EEIO) and southern Bay of Bengal (BoB) is investigated using altimetric data, and solutions to 1½ layer (first baroclinic mode) and linear, continuously stratified (LCS; multibaroclinic-mode) models. The amplitude and dominant periods of SSH variability differ regionally. Large-amplitude variability is found along the west coast of Sumatra, in a zonal band across the BoB centered along 5°N, east of Sri Lanka, and in the northwestern BoB, respectively. Along the Sumatran west coast, SSH variability peaks at 30-60, 90, and 180 days. Along 5°N and east of Sri Lanka, the 30-60 day variability is dominant. Sensitivity experiments using a nonlinear version of the 1½ layer model forced by realistic winds reproduce the observed patterns of intraseasonal variability in the southern BoB. At 30-60 days, the solutions show that eddies (nonlinear Rossby waves) propagating from the east, rather than local wind forcing, account for most of the variance east of Sri Lanka; furthermore, they demonstrate that the variance is significantly enhanced by the nonlinear transfer of 90-120 day energy into the intraseasonal band of 30-60 days. The LCS solutions show that the first two baroclinic modes explain most of the SSH variance at 90-180 days. The second baroclinic mode dominates the SSH variance at 180 days, a consequence of basin resonance and strong wind forcing.

  2. 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.

  3. Utilizing field-aligned current profiles derived from Swarm to estimate the peak emission height of 630 nm auroral arcs: a comparison of methods and discussion of associated error estimates in the ASI data.

    Science.gov (United States)

    Gillies, D. M.; Knudsen, D. J.; Donovan, E.; Jackel, B. J.; Gillies, R.; Spanswick, E.

    2017-12-01

    We compare field-aligned currents (FACs) measured by the Swarm constellation of satellites with the location of red-line (630 nm) auroral arcs observed by all-sky imagers (ASIs) to derive a characteristic emission height for the optical emissions. In our 10 events we find that an altitude of 200 km applied to the ASI maps gives optimal agreement between the two observations. We also compare the new FAC method against the traditional triangulation method using pairs of all-sky imagers (ASIs), and against electron density profiles obtained from the Resolute Bay Incoherent Scatter Radar-Canadian radar (RISR-C), both of which are consistent with a characteristic emission height of 200 km. We also present the spatial error associated with georeferencing REdline Geospace Observatory (REGO) and THEMIS all-sky imagers (ASIs) and how it applies to altitude projections of the mapped image. Utilizing this error we validate the estimated altitude of redline aurora using two methods: triangulation between ASIs and field-aligned current profiles derived from magnetometers on-board the Swarm satellites.

  4. Development of methods for inferring cloud thickness and cloud-base height from satellite radiance data

    Science.gov (United States)

    Smith, William L., Jr.; Minnis, Patrick; Alvarez, Joseph M.; Uttal, Taneil; Intrieri, Janet M.; Ackerman, Thomas P.; Clothiaux, Eugene

    1993-01-01

    Cloud-top height is a major factor determining the outgoing longwave flux at the top of the atmosphere. The downwelling radiation from the cloud strongly affects the cooling rate within the atmosphere and the longwave radiation incident at the surface. Thus, determination of cloud-base temperature is important for proper calculation of fluxes below the cloud. Cloud-base altitude is also an important factor in aircraft operations. Cloud-top height or temperature can be derived in a straightforward manner using satellite-based infrared data. Cloud-base temperature, however, is not observable from the satellite, but is related to the height, phase, and optical depth of the cloud in addition to other variables. This study uses surface and satellite data taken during the First ISCCP Regional Experiment (FIRE) Phase-2 Intensive Field Observation (IFO) period (13 Nov. - 7 Dec. 1991, to improve techniques for deriving cloud-base height from conventional satellite data.

  5. Probing the Active Surface Sites for CO Reduction on Oxide-Derived Copper Electrocatalysts

    DEFF Research Database (Denmark)

    Verdaguer Casadevall, Arnau; Li, Christina W.; Johansson, Tobias Peter

    2015-01-01

    CO electroreduction activity on oxide-derived Cu (OD-Cu) was found to correlate with metastable surface features that bind CO strongly. OD-Cu electrodes prepared by H-2 reduction of Cu2O precursors reduce CO to acetate and ethanol with nearly 50% Faradaic efficiency at moderate overpotential. Tem...

  6. Titanium Surface Coating with a Laminin-Derived Functional Peptide Promotes Bone Cell Adhesion

    Directory of Open Access Journals (Sweden)

    Seung-Ki Min

    2013-01-01

    Full Text Available Laminin-derived peptide coatings can enhance epithelial cell adhesion to implants, and the positive effect of these peptides on bone cell adhesion has been anticipated. The purpose of this study was to evaluate the improvement in bone cell attachment to and activity on titanium (Ti scaffolds coated with a laminin-derived functional peptide, Ln2-P3 (the DLTIDDSYWYRI motif. Four Ti disc surfaces were prepared, and a human osteosarcoma (HOS cell attachment test was performed to select two candidate surfaces for peptide coating. These two candidates were then coated with Ln2-P3 peptide, a scrambled peptide, or left uncoated to measure cell attachment to each surface, following which one surface was chosen to assess alkaline phosphatase (ALP activity and osteogenic marker gene expression with quantitative real-time PCR. On the commercially pure Ti surface, the Ln2-P3 coating significantly increased cellular ALP activity and the expression levels of ALP and bone sialoprotein mRNA as compared with the scrambled peptide-coated and uncoated surfaces. In conclusion, although further in vivo studies are needed, the findings of this in vitro study indicate that the Ln2-P3-coated implant surface promotes bone cell adhesion, which has clinical implications for reducing the overall treatment time of dental implant therapy.

  7. Surface chemical functionalities affect the behavior of human adipose-derived stem cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xujie [State key laboratory of new ceramics and fine processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Feng, Qingling, E-mail: biomater@mail.tsinghua.edu.cn [State key laboratory of new ceramics and fine processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Bachhuka, Akash [Mawson Institute, University of South Australia, Mawson Lakes 5095 (Australia); Vasilev, Krasimir [Mawson Institute, University of South Australia, Mawson Lakes 5095 (Australia); School of Advanced Manufacturing, University of South Australia, Mawson Lakes 5095 (Australia)

    2013-04-01

    This study examines the effect of surface chemical functionalities on the behavior of human adipose-derived stem cells (hASCs) in vitro. Plasma polymerized films rich in amine (-NH{sub 2}), carboxyl (-COOH) and methyl (-CH{sub 3}), were generated on hydroxyapatite (HAp) substrates. The surface chemical functionalities were characterized by X-ray photoelectron spectroscopy (XPS). The ability of different substrates to absorb proteins was evaluated. The results showed that substrates modified with hydrophilic functional group (-COOH and -NH{sub 2}) can absorb more proteins than these modified with more hydrophobic functional group (-CH{sub 3}). The behavior of human adipose-derived stem cells (hASCs) cultured on different substrates was investigated in vitro: cell counting kit-8 (CCK-8) analysis was used to characterize cell proliferation, scanning electronic microscopy (SEM) analysis was used to characterize cell morphology and alkaline phosphatase (ALP) activity analysis was used to account for differentiation. The results of this study demonstrated that the -NH{sub 2} modified surfaces encourage osteogenic differentiation; the -COOH modified surfaces promote cell adhesion and spreading and the -CH{sub 3} modified surfaces have the lowest ability to induce osteogenic differentiation. These findings confirmed that the surface chemical states of biomaterials can affect the behavior of hASCs in vitro.

  8. Surface nanotopography guides kidney-derived stem cell differentiation into podocytes.

    Science.gov (United States)

    MacGregor-Ramiasa, Melanie; Hopp, Isabel; Bachhuka, Akash; Murray, Patricia; Vasilev, Krasimir

    2017-07-01

    Stem cells have enormous potential for developing novel therapies for kidney disease but our current inability to direct their differentiation to specialised renal cells presents a barrier to their use in renal bioengineering and drug development programmes. Here, a plasma-based technology was used to produce a range of biocompatible substrates comprising controlled surface nanotopography and tailored outermost chemical functionalities. These novel substrata were used to investigate the response of mouse kidney-derived stem cells to changes in both substrate nanotopography and surface chemistry. The stem cells proliferated to a similar extent on all substrates, but specific combinations of nanotopography and surface chemistry promoted differentiation into either podocyte or proximal tubule-like cells. The data reveal that high density of surface nanodefects in association with amine rich chemistry primarily lead to differentiation into podocytes while surfaces with low amine content constituted better substrates for differentiation into proximal tubule cells regardless of the surface nanotopographic profile. Thus plasma coated nanorough substrate may provide useful platform for guiding the fate kidney stem cell in vitro. Adult kidney-derived stem cells have been identified as a promising way to regenerate damaged nephrons. Artificial growth platforms capable to guide the stem cells differentiation into useful cell lineages are needed to expand regenerative cell therapies for chronic kidney diseases. Chemically homogeneous growth substrates endowed with nanotopography gradients were generated via plasma assisted methods in order to investigate the effect of physical cues on the proliferation and differentiation of kidney-derived stem cells. For the first time it is shown that the surface density of the nano-structures had a greater impact on fate of the stem cells than their size. Careful design of the growth substrate nanotopography may help directing the

  9. Improving evapotranspiration in a land surface model using biophysical variables derived from MSG/SEVIRI satellite

    Directory of Open Access Journals (Sweden)

    N. Ghilain

    2012-08-01

    Full Text Available Monitoring evapotranspiration over land is highly dependent on the surface state and vegetation dynamics. Data from spaceborn platforms are desirable to complement estimations from land surface models. The success of daily evapotranspiration monitoring at continental scale relies on the availability, quality and continuity of such data. The biophysical variables derived from SEVIRI on board the geostationary satellite Meteosat Second Generation (MSG and distributed by the Satellite Application Facility on Land surface Analysis (LSA-SAF are particularly interesting for such applications, as they aimed at providing continuous and consistent daily time series in near-real time over Africa, Europe and South America. In this paper, we compare them to monthly vegetation parameters from a database commonly used in numerical weather predictions (ECOCLIMAP-I, showing the benefits of the new daily products in detecting the spatial and temporal (seasonal and inter-annual variability of the vegetation, especially relevant over Africa. We propose a method to handle Leaf Area Index (LAI and Fractional Vegetation Cover (FVC products for evapotranspiration monitoring with a land surface model at 3–5 km spatial resolution. The method is conceived to be applicable for near-real time processes at continental scale and relies on the use of a land cover map. We assess the impact of using LSA-SAF biophysical variables compared to ECOCLIMAP-I on evapotranspiration estimated by the land surface model H-TESSEL. Comparison with in-situ observations in Europe and Africa shows an improved estimation of the evapotranspiration, especially in semi-arid climates. Finally, the impact on the land surface modelled evapotranspiration is compared over a north–south transect with a large gradient of vegetation and climate in Western Africa using LSA-SAF radiation forcing derived from remote sensing. Differences are highlighted. An evaluation against remote sensing derived land

  10. Lake Chad Total Surface Water Area as Derived from Land Surface Temperature and Radar Remote Sensing Data

    Directory of Open Access Journals (Sweden)

    Frederick Policelli

    2018-02-01

    Full Text Available Lake Chad, located in the middle of the African Sahel belt, underwent dramatic decreases in the 1970s and 1980s leaving less than ten percent of its 1960s surface water extent as open water. In this paper, we present an extended record (dry seasons 1988–2016 of the total surface water area of the lake (including both open water and flooded vegetation derived using Land Surface Temperature (LST data (dry seasons 2000–2016 from the NASA Terra MODIS sensor and EUMETSAT Meteosat-based LST measurements (dry seasons 1988–2001 from an earlier study. We also examine the total surface water area for Lake Chad using radar data (dry seasons 2015–2016 from the ESA Sentinel-1a mission. For the limited number of radar data sets available to us (18 data sets, we find on average a close match between the estimates from these data and the corresponding estimates from LST, though we find spatial differences in the estimates using the two types of data. We use these spatial differences to adjust the record (dry seasons 2000–2016 from MODIS LST. Then we use the adjusted record to remove the bias of the existing LST record (dry seasons 1988–2001 derived from Meteosat measurements and combine the two records. From this composite, extended record, we plot the total surface water area of the lake for the dry seasons of 1988–1989 through 2016–2017. We find for the dry seasons of 1988–1989 to 2016–2017 that the maximum total surface water area of the lake was approximately 16,800 sq. km (February and May, 2000, the minimum total surface water area of the lake was approximately 6400 sq. km (November, 1990, and the average was approximately 12,700 sq. km. Further, we find the total surface water area of the lake to be highly variable during this period, with an average rate of increase of approximately 143 km2 per year.

  11. Damping of short gravity-capillary waves due to oil derivatives film on the water surface

    Science.gov (United States)

    Sergievskaya, Irina; Ermakov, Stanislav; Lazareva, Tatyana

    2016-10-01

    In this paper new results of laboratory studies of damping of gravity-capillary waves on the water surface covered by kerosene are presented and compared with our previous analysis of characteristics of crude oil and diesel fuel films. Investigations of kerosene films were carried out in a wide range values of film thicknesses (from some hundreds millimetres to a few millimetres) and in a wide range of surface wave frequencies (from 10 to 27 Hz). The selected frequency range corresponds to the operating wavelengths of microwave, X- to Ka-band radars typically used for the ocean remote sensing. The studied range of film thickness covers typical thicknesses of routine spills in the ocean. It is obtained that characteristics of waves, measured in the presence of oil derivatives films differ from those for crude oil films, in particular, because the volume viscosity of oil derivatives and crude oil is strongly different. To retrieve parameters of kerosene films from the experimental data the surface wave damping was analyzed theoretically in the frame of a model of two-layer fluid. The films are assumed to be soluble, so the elasticity on the upper and lower boundaries is considered as a function of wave frequency. Physical parameters of oil derivative films were estimated when tuning the film parameters to fit theory and experiment. Comparison between wave damping due to crude oil, kerosene and diesel fuel films have shown some capabilities of distinguishing of oil films from remote sensing of short surface waves.

  12. Arctic Ocean gravity, geoid and sea-ice freeboard heights from ICESat and GRACE

    DEFF Research Database (Denmark)

    Forsberg, René; Skourup, Henriette

    2005-01-01

    ICESat laser measurements provide a high-resolution mapping of the sea-ice surface of the Arctic Ocean, which can be inverted to determine gravity anomalies and sea-ice freeboard heights by a "lowest-level'' filtering scheme. In this paper we use updated terrestrial gravity data from the Arctic...... Gravity Project in combination with GRACE gravity field models to derive an improved Arctic geoid model. This model is then used to convert ICESat measurements to sea-ice freeboard heights with a coarse lowest-level surface method. The derived freeboard heights show a good qualitative agreement...... to the coverage of multi-year sea-ice; however, comparison to an airborne lidar underflight north of Greenland shows that the lowest-level filtering scheme may introduce a bias. We finally use the ICESat and GRACE results to derive new gravity anomalies by Fourier inversion. The satellite-only gravity field shows...

  13. Induced wettability and surface-volume correlation of composition for bovine bone derived hydroxyapatite particles

    Science.gov (United States)

    Maidaniuc, Andreea; Miculescu, Florin; Voicu, Stefan Ioan; Andronescu, Corina; Miculescu, Marian; Matei, Ecaterina; Mocanu, Aura Catalina; Pencea, Ion; Csaki, Ioana; Machedon-Pisu, Teodor; Ciocan, Lucian Toma

    2018-04-01

    Hydroxyapatite powders characteristics need to be determined both for quality control purposes and for a proper control of microstructural features of bone reconstruction products. This study combines bulk morphological and compositional analysis methods (XRF, SEM-EDS, FT-IR) with surface-related methods (XPS, contact angle measurements) in order to correlate the characteristics of hydroxyapatite powders derived from bovine bone for its use in medical applications. An experimental approach for correlating the surface and volume composition was designed based on the analysis depth of each spectral method involved in the study. Next, the influences of powder particle size and forming method on the contact angle between water drops and ceramic surface were evaluated for identifying suitable strategies of tuning hydroxyapatite's wettability. The results revealed a preferential arrangement of chemical elements at the surface of hydroxyapatite particles which could induce a favourable material behaviour in terms of sinterability and biological performance.

  14. Enhanced biofouling resistance of polyethersulfone membrane surface modified with capsaicin derivative and itaconic acid

    International Nuclear Information System (INIS)

    Wang, Jian; Gao, Xueli; Wang, Qun; Sun, Haijing; Wang, Xiaojuan; Gao, Congjie

    2015-01-01

    Graphical abstract: - Highlights: • PES membrane was modified with a capsaicin derivative. • UV-assisted graft polymerization was carried out on membrane surface. • The capsaicin derivative modified membrane shows better antibiofouling property. - Abstract: The culprit of biofouling is the reproduction of viable microorganisms on the membrane surface. Recently, functionalization of membrane surface with natural antibacterial agents has drawn great attention. This work presents the fabrication of antibiofouling polyethersulfone (PES) ultrafiltration (UF) membranes by UV-assisted photo grafting of capsaicin derivative (N-(4-hydroxy-3-methoxy-benzyl)-acrylamide, HMBA) and itaconic acid (IA) on the surface of PES membrane. Results of FTIR-ATR, water static contact angle (WSCA) and atomic force microscopy (AFM) analysis confirmed the successful grafting of HMBA and IA on the membrane surface. We investigated the antifouling and antibacterial properties of these membranes using BSA and Escherichia coli as the test model, respectively. During a 150-min test, the modified membranes show much lower flux decline (42.7% for PES-g-1H0I, 22.2% for PES-g-1H1I and 7.7% for PES-g-1H5I) when compared with the pristine membrane (flux declined by 77%). The modified membranes exhibit excellent antibacterial activity (nearly 100%) when UV irradiation time was 6 min. The morphological study suggested that the E. coli on the pristine membrane showed a regular and smooth surface while that on the modified membrane was disrupted, which validated the antibacterial activity of the modified membranes.

  15. Enhanced biofouling resistance of polyethersulfone membrane surface modified with capsaicin derivative and itaconic acid

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jian [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100 (China); College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100 (China); Gao, Xueli, E-mail: gxl_ouc@126.com [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100 (China); College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100 (China); Wang, Qun; Sun, Haijing; Wang, Xiaojuan [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100 (China); College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100 (China); Gao, Congjie, E-mail: gaocjie@ouc.edu.cn [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100 (China); College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100 (China)

    2015-11-30

    Graphical abstract: - Highlights: • PES membrane was modified with a capsaicin derivative. • UV-assisted graft polymerization was carried out on membrane surface. • The capsaicin derivative modified membrane shows better antibiofouling property. - Abstract: The culprit of biofouling is the reproduction of viable microorganisms on the membrane surface. Recently, functionalization of membrane surface with natural antibacterial agents has drawn great attention. This work presents the fabrication of antibiofouling polyethersulfone (PES) ultrafiltration (UF) membranes by UV-assisted photo grafting of capsaicin derivative (N-(4-hydroxy-3-methoxy-benzyl)-acrylamide, HMBA) and itaconic acid (IA) on the surface of PES membrane. Results of FTIR-ATR, water static contact angle (WSCA) and atomic force microscopy (AFM) analysis confirmed the successful grafting of HMBA and IA on the membrane surface. We investigated the antifouling and antibacterial properties of these membranes using BSA and Escherichia coli as the test model, respectively. During a 150-min test, the modified membranes show much lower flux decline (42.7% for PES-g-1H0I, 22.2% for PES-g-1H1I and 7.7% for PES-g-1H5I) when compared with the pristine membrane (flux declined by 77%). The modified membranes exhibit excellent antibacterial activity (nearly 100%) when UV irradiation time was 6 min. The morphological study suggested that the E. coli on the pristine membrane showed a regular and smooth surface while that on the modified membrane was disrupted, which validated the antibacterial activity of the modified membranes.

  16. Determination of Vertical Datum Offset between the Regional and the Global Height Datum

    Directory of Open Access Journals (Sweden)

    LI Jiancheng

    2017-10-01

    Full Text Available The unification of the global height datum is a key problem to be solved for geodesy after the unification of global geodetic coordination system and three-dimension spatial datum, and the basis of global spatial information sharing and exchange. In this paper, the theoretical and practical problems of vertical datum offset between the regional height datum and the global height datum are studied. Based on the classical theory of the height system in physical geodesy, the definition of the height datum vertical offset is given, and the rigorous formulas for calculating the vertical offset are derived. The formulas can be used to deduce the three methods of the height datum vertical offset determination. On that basis, the influences of different reference system and reference ellipsoid parameters on the calculation of the vertical offset are analyzed. The results show that the reference system and the ellipsoid parameter conversion are very necessary. At the same time, the height anomaly differences method needs to consider the degree zero correction caused by the inconsistency between gravity potential of the global height datum and the one computed by the model. Based on potential difference approach and the height anomaly difference method, the vertical offset between the China 1985 national height datum and the global height datum corresponding to the normal gravity potential U0 of GRS80, WGS-84 and CGCS2000 reference ellipsoidal from the 152 GPS/leveling points near the origin of Qingdao height origin and the EGM2008, EIGEN-6C4 and SGG-UGM-1 model. The regional datum is 23.1 cm lower than the global datum based on EIGEN-6C4 and WGS-84. When the Gauss-Listing geoid (mean sea surface is selected as the global height datum, the China 1985 national height datum is 21.0 cm higher than the global height datum. The results also show that there are still large differences among the accuracies of the current gravity field models on these GPS

  17. Uranium binding by biochar fibres derived from Luffa cylindrica after controlled surface oxidation

    International Nuclear Information System (INIS)

    Liatsou, Ioanna; Michail, Georgia; Demetriou, Marilena; Pashalidis, Ioannis

    2017-01-01

    Controlled surface modification of biochar fibres derived from Luffa cylindrica sponges has been carried out by nitric acid and the degree of oxidation could be controlled by changing the acid concentration or the reaction time. The extent of surface oxidation has been quantified by acid-base titration and FTIR-spectroscopy. Furthermore, uranium binding has been studied as a function of various parameters and the experimental results show that even under strong acidic conditions the relative sorption is above 80 % and the sorption capacity of the biochar fibres for U(VI) at pH 3 is q max = 92 g kg -1 . (author)

  18. Thorium binding by biochar fibres derived from Luffa Cylindrica after controlled surface oxidation

    Science.gov (United States)

    Liatsou, Ioanna; Christodoulou, Eleni; Paschalidis, Ioannis

    2017-04-01

    Controlled surface modification of biochar fibres derived from Luffa Cylindrica sponges has been carried out by nitric acid and the degree of oxidation could be controlled by changing the acid concentration or the reaction time. The extent of surface oxidation has been quantified by acid-base titration and FTIR-spectroscopy. Furthermore, thorium binding has been studied as a function of various parameters and the experimental results show that even under strong acidic conditions the relative sorption is above 70% and the sorption capacity of the biochar fibres for Th(IV) at pH 3 is qmax= 70 gṡkg-1.

  19. Overlayer structure of subphthalocyanine derivative deposited on Au (111) surface by a spray-jet technique

    International Nuclear Information System (INIS)

    Suzuki, Hitoshi; Yamada, Toshiki; Miki, Hideki; Mashiko, Shinro

    2006-01-01

    A new spray-jet technique was used to deposit subphthalocyanine derivative (chloro[tri-tert-butyl subphthalocyaninato]boron (TBSubPc)) on Au (111) surface in an ultra-high vacuum (UHV) chamber. The deposited molecular overlayer was observed with UHV scanning tunneling microscopy (STM) at 77 K. The STM images showed that TBSubPc molecules formed a stripe pattern with regular spacing, indicating that they preferentially adsorbed along the herringbone structure of the Au (111) surface. This behavior was very similar to that of TBSubPc molecules deposited by thermal evaporation

  20. Interactions of Lysozyme and Azobenzene Derivatives in the Solution and on a Surface

    Science.gov (United States)

    Wei, Tao; Shing, Katherine

    2015-03-01

    The reversible isomerization of the azobenzene and its derivatives can control protein structure in an aqueous environment with the alternation of visible and UV lights for very promising applications in drug delivery. However, an atomistic description of Azo-molecules and protein amino acid residues is still lacking. In this study we performed atomistic molecular dynamics simulation to study the interactions between a lysozyme molecule and the Azobenzene derivative (in the bulk solution and grafted on the Silica surfaces). Protein structural arrangements (i.e., the shape and secondary structures) and its mobility, as a function of tran/cis ratio in the bulk solution and on the self-assembling monolayer surface's density and morphology, are systematically investigated.

  1. Comparison of MODIS-derived land surface temperature with air temperature measurements

    Science.gov (United States)

    Georgiou, Andreas; Akçit, Nuhcan

    2017-09-01

    Air surface temperature is an important parameter for a wide range of applications such as agriculture, hydrology and climate change studies. Air temperature data is usually obtained from measurements made in meteorological stations, providing only limited information about spatial patterns over wide areas. The use of remote sensing data can help overcome this problem, particularly in areas with low station density, having the potential to improve the estimation of air surface temperature at both regional and global scales. Land Surface (skin) Temperatures (LST) derived from Moderate Resolution Imaging Spectroradiometer (MODIS) sensor aboard the Terra and Aqua satellite platforms provide spatial estimates of near-surface temperature values. In this study, LST values from MODIS are compared to groundbased near surface air (Tair) measurements obtained from 14 observational stations during 2011 to 2015, covering coastal, mountainous and urban areas over Cyprus. Combining Terra and Aqua LST-8 Day and Night acquisitions into a mean monthly value, provide a large number of LST observations and a better overall agreement with Tair. Comparison between mean monthly LSTs and mean monthly Tair for all sites and all seasons pooled together yields a very high correlation and biases. In addition, the presented high standard deviation can be explained by the influence of surface heterogeneity within MODIS 1km2 grid cells, the presence of undetected clouds and the inherent difference between LST and Tair. However, MODIS LST data proved to be a reliable proxy for surface temperature and mostly for studies requiring temperature reconstruction in areas with lack of observational stations.

  2. 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.

  3. The Impact of Surface Chemistry on Bio-derived Carbon Performance as Supercapacitor Electrodes

    KAUST Repository

    Alshareef, Husam N.

    2016-12-23

    In this study, we demonstrate that highly functionalized and porous carbons can be derived from palm-leaf waste using the template-free facile synthesis process. The derived carbons have high content of nitrogen dopant, high surface area, and various defects. Moreover, these carbons exhibit a high electrical conductivity (107 S m−1). Thanks to the high content of edge N (64.3%) and highly microporous nature (82% of microspores), these biomass-derived carbons show promising performance when used as supercapacitor electrodes. To be specific, these carbonaceous materials show a specific capacitance as high as 197 and 135 F g−1 at 2 and 20 A g−1 in three-electrode configuration, respectively. Furthermore, the symmetrical cells using palm-leaf-derived carbon show an energy density of 8.4 Wh Kg−1 at a power density of 0.64 kW Kg−1, with high cycling life stability (∼8% loss after 10,000 continuous charge–discharge cycles at 20 A g−1). Interestingly, as the power density increases from 4.4 kW kg−1 to 36.8 kW kg−1, the energy density drops slowly from 8.4 Wh kg−1 to 3.4 Wh kg−1. Getting such extremely high power density without significant loss of energy density indicates that these palm-leaf-derived carbons have excellent electrode performance as supercapacitor electrodes.

  4. Modification of the cellulosic component of hemp fibers using sulfonic acid derivatives: Surface and thermal characterization.

    Science.gov (United States)

    George, Michael; Mussone, Paolo G; Bressler, David C

    2015-12-10

    The aim of this study was to characterize the surface, morphological, and thermal properties of hemp fibers treated with two commercially available, inexpensive, and water soluble sulfonic acid derivatives. Specifically, the cellulosic component of the fibers were targeted, because cellulose is not easily removed during chemical treatment. These acids have the potential to selectively transform the surfaces of natural fibers for composite applications. The proposed method proceeds in the absence of conventional organic solvents and high reaction temperatures. Surface chemical composition and signature were measured using gravimetric analysis, X-ray photoelectron spectroscopy (XPS) and Fourier transform infra-red spectroscopy (FTIR). XPS data from the treated hemp fibers were characterized by measuring the reduction in O/C ratio and an increase in abundance of the C-C-O signature. FTIR confirmed the reaction with the emergence of peaks characteristic of disubstituted benzene and amino groups. Grafting of the sulfonic derivatives resulted in lower surface polarity. Thermogravimetric analysis revealed that treated fibers were characterized by lower percent degradation between 200 and 300 °C, and a higher initial degradation temperature. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Methods for the calculation of derived working limits for surface contamination by low-toxicity radionuclides

    International Nuclear Information System (INIS)

    Gibson, J.A.B.; Wrixon, A.D.

    1979-01-01

    Surface contamination is often measured as an indication of the general spread of radioactive contamination in a particular place. Derived working limits, (DWLs) for surface contamination provide figures against which to assess the significance of measurements. Derived working limits for surface contamination were first established for use in the nuclear energy industry. They were designed to cope with a wide range of unspecified radionuclides and were therefore based on the assumption that the contamination was due to the presence of the most hazardous radionuclides, e.g. 90 Sr, 210 Pb, 226 Ra and 239 Pu. While this assumption may still be appropriate when the radionuclide mixture is unknown, there are now many specialized uses of particular low-toxicity radionuclides in universities, hospitals and general industry. If it is known that only a particular radionuclide is present, the general DWL can be replaced by a more specific value. The methods for calculating DWLs for some of the more commonly employed low-toxicity radionuclides are described. The exposure pathways considered are (a) external radiation of the skin and inhalation of airborne material from contaminated surfaces in active areas; (b) external irradiation of the skin and ingestion from contaminated skin. Some consideration is given to the effect of the revised dose equivalent limits in the most recent recommendations of ICRP. (author)

  6. Replacing orthometric heights with ellipsoidal heights in ...

    African Journals Online (AJOL)

    Differential Global Positioning System (DGPS) is one of the most frequently used positioning methods in geodesy. The end products of surveying with Global Navigation Satellite Systems (GNSS)are geodetic latitude (ϕ), geodetic longitude (λ) and ellipsoidal height (h) which are obtained with reference to the ellipsoid.

  7. Three-dimensional surface deformation derived from airborne interferometric UAVSAR: Application to the Slumgullion Landslide

    Science.gov (United States)

    Delbridge, Brent G.; Burgmann, Roland; Fielding, Eric; Hensley, Scott; Schulz, William

    2016-01-01

    In order to provide surface geodetic measurements with “landslide-wide” spatial coverage, we develop and validate a method for the characterization of 3-D surface deformation using the unique capabilities of the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) airborne repeat-pass radar interferometry system. We apply our method at the well-studied Slumgullion Landslide, which is 3.9 km long and moves persistently at rates up to ∼2 cm/day. A comparison with concurrent GPS measurements validates this method and shows that it provides reliable and accurate 3-D surface deformation measurements. The UAVSAR-derived vector velocity field measurements accurately capture the sharp boundaries defining previously identified kinematic units and geomorphic domains within the landslide. We acquired data across the landslide during spring and summer and identify that the landslide moves more slowly during summer except at its head, presumably in response to spatiotemporal variations in snowmelt infiltration. In order to constrain the mechanics controlling landslide motion from surface velocity measurements, we present an inversion framework for the extraction of slide thickness and basal geometry from dense 3-D surface velocity fields. We find that the average depth of the Slumgullion Landslide is 7.5 m, several meters less than previous depth estimates. We show that by considering a viscoplastic rheology, we can derive tighter theoretical bounds on the rheological parameter relating mean horizontal flow rate to surface velocity. Using inclinometer data for slow-moving, clay-rich landslides across the globe, we find a consistent value for the rheological parameter of 0.85 ± 0.08.

  8. Forest Canopy Height Estimation from Calipso Lidar Measurement

    Directory of Open Access Journals (Sweden)

    Lu Xiaomei

    2016-01-01

    Canopy penetration depths at two wavelengths indicate moderately strong relationships for estimating the canopy height. Results show that the CALIOP-derived canopy heights were highly correlated with the ICESat/GLAS-derived values with a mean RMSE of 3.4 m and correlation coefficient (R of 0.89. Our findings present a relationship between the penetration difference and canopy height, which can be used as another metrics for canopy height estimation, except the full waveforms.

  9. Advances in electric field and atomic surface derived properties from experimental electron densities.

    Science.gov (United States)

    Bouhmaida, Nouzha; Ghermani, Nour Eddine

    2008-07-14

    The present study is devoted to a general use of the Gauss law. This is applied to the atomic surfaces derived from the topological analysis of the electron density. The method proposed here is entirely numerical, robust and does not necessitate any specific parametrization of the atomic surfaces. We focus on two fundamental properties: the atomic charges and the electrostatic forces acting on atoms in molecules. Application is made on experimental electron densities modelized by the Hansen-Coppens model from which the electric field is derived for a heterogenic set of compounds: water molecule, NO(3) anion, bis-triazine molecule and MgO cluster. Charges and electrostatic forces are estimated by the atomic surface flux of the electric field and the Maxwell stress tensor, respectively. The charges obtained from the present method are in good agreement with those issued from the conventional volume integration. Both Feynman and Ehrenfest forces as well as the electrostatic potential at the nuclei (EPN) are here estimated from the experimental electron densities. The values found for the molecular compounds are presented and discussed in the scope of the mechanics of atomic interactions.

  10. Surfaces wettability and morphology modulation in a fluorene derivative self-assembly system

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Xinhua, E-mail: caoxhchem@163.com; Gao, Aiping; Zhao, Na; Yuan, Fangyuan; Liu, Chenxi; Li, Ruru

    2016-04-15

    Graphical abstract: - Highlights: • The different structures could be obtained in this self-assembly system. • A water-drop could freely roll on the xerogel film with the sliding angle of 15.0. • The superhydrophobic surface can be obtained via supramolecular self-assembly. - Abstract: A new organogelator based on fluorene derivative (gelator 1) was designed and synthesized. Organogels could be obtained via the self-assembly of the derivative in acetone, toluene, ethyl acetate, hexane, DMSO and petroleum ether. The self-assembly process was thoroughly characterized using field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), UV–vis, FT-IR and the contact angle. Surfaces with different morphologies and wetting properties were formed via the self-assembly of gelator 1 in the six different solvents. Interestingly, a superhydrophobic surface with a contact angle of 150° was obtained from organogel 1 in DMSO and exhibited the lotus-effect. The sliding angle necessary for a water droplet to move on the glass was only 15°. Hydrogen bonding and van der Waals forces were attributed as the main driving forces for gel formation.

  11. Derived surface contamination limits for the uranium mining and milling industry

    International Nuclear Information System (INIS)

    Ching, S.H.

    1984-10-01

    Derived Surface Contamination Limits (DSCL) are proposed for the control of surface contamination at the work place for the uranium mining and milling industry. They have been derived by a method incorporating recent ICRP recommendations and consideration of the radiation exposure pathways of ingestion, inhalation and external irradiation of the basal layer of skin. A generalized DSCL of 10 5 Bq/m 2 of beta activity is recommended for all contaminants likely to be found in uranium mine and mill workplaces except for fresh uranium concentrates. In the latter case, the DSCL is expressed in terms of alpha activity because the ratio of beta to alpha activities for fresh uranium concentrates is variable; the beta activity increases with the ingrowth of U-238 daughter products (Th-234 and Pa-234m) until secular equilibrium is re-established in about six months. A surface contamination limit of 10 4 Bq/m 2 of beta activity is proposed for the release of non-porous materials and equipment with no detectable loose contamination to the public domain

  12. ASTER-Derived High-Resolution Ice Surface Temperature for the Arctic Coast

    Directory of Open Access Journals (Sweden)

    Young-Sun Son

    2018-04-01

    Full Text Available Ice surface temperature (IST controls the rate of sea ice growth and the heat exchange between the atmosphere and ocean. In this study, high-resolution IST using the Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER thermal infrared region (TIR images was retrieved to observe the thermal change of coastal sea ice. The regression coefficients of the multi-channel equation using ASTER brightness temperatures ( B T and MODIS ISTs were derived. MODIS IST products (MOD29 were used as an in situ temperature substitute. The ASTER IST using five channels from band 10 ( B T 10 to band 14 ( B T 14 showed an RMSE of 0.746 K for the validation images on the Alaskan coast. The uncertainty of the two-channel ( B T 13 and B T 14 ASTER IST was 0.497 K, which was better than that of the five-channel. We thus concluded that the two-channel equation using ASTER B T 13 and B T 14 was an optimal model for the surface temperature retrieval of coastal sea ice. The two-channel ASTER IST showed similar accuracy at higher latitudes than in Alaska. Therefore, ASTER-derived IST with 90 m spatial resolution can be used to observe small-scale thermal variations on the sea ice surface along the Arctic coast.

  13. Use of cellulose derivatives on gold surfaces for reduced nonspecific adsorption of immunoglobulin G.

    Science.gov (United States)

    Volden, Sondre; Zhu, Kaizheng; Nyström, Bo; Glomm, Wilhelm R

    2009-09-01

    This study addresses the design of protein-repellent gold surfaces using hydroxyethyl- and ethyl(hydroxyethyl) cellulose (HEC and EHEC) and hydrophobically modified analogues of these polymers (HM-HEC and HM-EHEC). Adsorption behavior of the protein immunoglobulin G (IgG) onto pure gold and gold surfaces coated with cellulose polymers was investigated and described by quartz crystal microbalance with dissipation monitoring (QCM-D), atomic force microscopy (AFM) and contact angle measurements (CAM). Surfaces coated with the hydrophobically modified cellulose derivatives were found to significantly outperform a reference poly(ethylene glycol) (PEG) coating, which in turn prevented 90% of non-specific protein adsorption as compared to adsorption onto pure gold. HEC and EHEC prevented around 30% and 60% of the IgG adsorption observed on pure gold, while HM-HEC and HM-EHEC were both found to completely hinder biofouling when deposited on the gold substrates. Adsorption behavior of IgG has been discussed in terms of polymer surface coverage and roughness of the applied surfaces, together with hydrophobic interactions between protein and gold, and also polymer-protein interactions.

  14. Drainage Structure Datasets and Effects on LiDAR-Derived Surface Flow Modeling

    Directory of Open Access Journals (Sweden)

    Ruopu Li

    2013-12-01

    Full Text Available With extraordinary resolution and accuracy, Light Detection and Ranging (LiDAR-derived digital elevation models (DEMs have been increasingly used for watershed analyses and modeling by hydrologists, planners and engineers. Such high-accuracy DEMs have demonstrated their effectiveness in delineating watershed and drainage patterns at fine scales in low-relief terrains. However, these high-resolution datasets are usually only available as topographic DEMs rather than hydrologic DEMs, presenting greater land roughness that can affect natural flow accumulation. Specifically, locations of drainage structures such as road culverts and bridges were simulated as barriers to the passage of drainage. This paper proposed a geospatial method for producing LiDAR-derived hydrologic DEMs, which incorporates data collection of drainage structures (i.e., culverts and bridges, data preprocessing and burning of the drainage structures into DEMs. A case study of GIS-based watershed modeling in South Central Nebraska showed improved simulated surface water derivatives after the drainage structures were burned into the LiDAR-derived topographic DEMs. The paper culminates in a proposal and discussion of establishing a national or statewide drainage structure dataset.

  15. Observing Crop-Height Dynamics Using a UAV

    Science.gov (United States)

    Ziliani, M. G.; Parkes, S. D.; McCabe, M.

    2017-12-01

    Retrieval of vegetation height during a growing season is a key indicator for monitoring crop status, offering insight to the forecast yield relative to previous planting cycles. Improvement in Unmanned Aerial Vehicle (UAV) technologies, supported by advances in computer vision and photogrammetry software, has enabled retrieval of crop heights with much higher spatial resolution and coverage. These methodologies retrieve a Digital Surface Map (DSM), which combine terrain and crop elements to obtain a Crop Surface Map (CSM). Here we describe an automated method for deriving high resolution CSMs from a DSM, using RGB imagery from a UAV platform. Importantly, the approach does not require the need for a digital terrain map (DTM). The method involves distinguishing between vegetation and bare-ground cover pixels, using vegetation index maps from the RGB orthomosaic derived from the same flight as the DSM. We show that the absolute crop height can be extracted to within several centimeters, exploiting the data captured from a single UAV flight. In addition, the method is applied across five surveys during a maize growing cycle and compared against a terrain map constructed from a baseline UAV survey undertaken prior to crop growth. Results show that the approach is able to reproduce the observed spatial variability of the crop height within the maize field throughout the duration of the growing season. This is particularly valuable since it may be employed to detect intra-field problems (i.e. fertilizer variability, inefficiency in the irrigation system, salinity etc.) at different stages of the season, from which remedial action can be initiated to mitigate against yield loss. The method also demonstrates that UAV imagery combined with commercial photogrammetry software can determine a CSM from a single flight without the requirement of a prior DTM. This, together with the dynamic crop height estimation, provide useful information with which to inform precision

  16. The Impact of Microwave-Derived Surface Soil Moisture on Watershed Hydrological Modeling

    Science.gov (United States)

    ONeill, P. E.; Hsu, A. Y.; Jackson, T. J.; Wood, E. F.; Zion, M.

    1997-01-01

    The usefulness of incorporating microwave-derived soil moisture information in a semi-distributed hydrological model was demonstrated for the Washita '92 experiment in the Little Washita River watershed in Oklahoma. Initializing the hydrological model with surface soil moisture fields from the ESTAR airborne L-band microwave radiometer on a single wet day at the start of the study period produced more accurate model predictions of soil moisture than a standard hydrological initialization with streamflow data over an eight-day soil moisture drydown.

  17. Improving surface functional properties of tofu whey-derived peptides by chemical modification with fatty acids.

    Science.gov (United States)

    Matemu, Athanasia Oswald; Katayama, Shigeru; Kayahara, Hisataka; Murasawa, Hisashi; Nakamura, Soichiro

    2012-04-01

    Effect of acylation with saturated fatty acids on surface functional properties of tofu whey-derived peptides was investigated. Tofu whey (TW) and soy proteins (7S, 11S, and acid-precipitated soy protein [APP]) were hydrolyzed by Protease M 'Amano' G, and resulting peptide mixtures were acylated with esterified fatty acids of different chain length (6C to 18C) to form a covalent linkage between the carboxyl group of fatty acid and the free amino groups of peptide. Acylation significantly (P properties of 7S, 11S, and APP peptides independent of fatty acid chain length. Acylation decreased water binding capacity although oil binding capacity of acylated tofu whey ultra filtered fraction (UFTW acids had shown significant higher surface hydrophobicity as in contrast with acylated UFTW acids can further affect functional properties of soy proteins. © 2012 Institute of Food Technologists®

  18. Surface Markers for Chondrogenic Determination: A Highlight of Synovium-Derived Stem Cells

    Directory of Open Access Journals (Sweden)

    Douglas D. Campbell

    2012-11-01

    Full Text Available Cartilage tissue engineering is a promising field in regenerative medicine that can provide substantial relief to people suffering from degenerative cartilage disease. Current research shows the greatest chondrogenic potential for healthy articular cartilage growth with minimal hypertrophic differentiation to be from mesenchymal stem cells (MSCs of synovial origin. These stem cells have the capacity for differentiation into multiple cell lineages related to mesenchymal tissue; however, evidence exists for cell surface markers that specify a greater potential for chondrogenesis than other differentiation fates. This review will examine relevant literature to summarize the chondrogenic differentiation capacities of tested synovium-derived stem cell (SDSC surface markers, along with a discussion about various other markers that may hold potential, yet require further investigation. With this information, a potential clinical benefit exists to develop a screening system for SDSCs that will produce the healthiest articular cartilage possible.

  19. Progress Report On Techniques Deriving Land Cover And Earth Surface Deformation Information From Polarimetric SAR Interferometry

    Science.gov (United States)

    Pottier, E.; Chen, E.; Li, Z.; Hong, W.; Xiang, M.; Cloude, S. R.; Papathanassiou, K.; Cao, F.; Zhang, H.

    2010-10-01

    In this paper we provide an up-date of activities carried out under the DRAGON collaborative program in a project concerned with the application of Pol-InSAR to deriving land cover and Earth Surface deformation information. This project (ID. 5344) is based around four main scientific topics: Land Cover Analysis, Earth Surface Deformation Monitoring and DEM Extraction, Forest V ertical Structure Parameters Extraction and PolSARpro Software Development. We propose a brief summary of the project objectives and progress to date of each Work Packages, concentrating on different recent developments, original results and important highlights that have been presented during the Dragon2 Mid-Term Results Symposium, that was held on 17-21 May 2010, in Yangshuo, Guilin, P.R. China

  20. Enhancing the Bioconversion of Azelaic Acid to Its Derivatives by Response Surface Methodology.

    Science.gov (United States)

    Khairudin, Nurshafira; Basri, Mahiran; Fard Masoumi, Hamid Reza; Samson, Shazwani; Ashari, Siti Efliza

    2018-02-13

    Azelaic acid (AzA) and its derivatives have been known to be effective in the treatment of acne and various cutaneous hyperpigmentary disorders. The esterification of azelaic acid with lauryl alcohol (LA) to produce dilaurylazelate using immobilized lipase B from Candida antarctica (Novozym 435) is reported. Response surface methodology was selected to optimize the reaction conditions. A well-fitting quadratic polynomial regression model for the acid conversion was established with regards to several parameters, including reaction time and temperature, enzyme amount, and substrate molar ratios. The regression equation obtained by the central composite design of RSM predicted that the optimal reaction conditions included a reaction time of 360 min, 0.14 g of enzyme, a reaction temperature of 46 °C, and a molar ratio of substrates of 1:4.1. The results from the model were in good agreement with the experimental data and were within the experimental range (R² of 0.9732).The inhibition zone can be seen at dilaurylazelate ester with diameter 9.0±0.1 mm activities against Staphylococcus epidermidis S273. The normal fibroblasts cell line (3T3) was used to assess the cytotoxicity activity of AzA and AzA derivative, which is dilaurylazelate ester. The comparison of the IC 50 (50% inhibition of cell viability) value for AzA and AzA derivative was demonstrated. The IC 50 value for AzA was 85.28 μg/mL, whereas the IC 50 value for AzA derivative was more than 100 μg/mL. The 3T3 cell was still able to survive without any sign of toxicity from the AzA derivative; thus, it was proven to be non-toxic in this MTT assay when compared with AzA.

  1. Enhancing the Bioconversion of Azelaic Acid to Its Derivatives by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Nurshafira Khairudin

    2018-02-01

    Full Text Available Azelaic acid (AzA and its derivatives have been known to be effective in the treatment of acne and various cutaneous hyperpigmentary disorders. The esterification of azelaic acid with lauryl alcohol (LA to produce dilaurylazelate using immobilized lipase B from Candida antarctica (Novozym 435 is reported. Response surface methodology was selected to optimize the reaction conditions. A well-fitting quadratic polynomial regression model for the acid conversion was established with regards to several parameters, including reaction time and temperature, enzyme amount, and substrate molar ratios. The regression equation obtained by the central composite design of RSM predicted that the optimal reaction conditions included a reaction time of 360 min, 0.14 g of enzyme, a reaction temperature of 46 °C, and a molar ratio of substrates of 1:4.1. The results from the model were in good agreement with the experimental data and were within the experimental range (R2 of 0.9732.The inhibition zone can be seen at dilaurylazelate ester with diameter 9.0±0.1 mm activities against Staphylococcus epidermidis S273. The normal fibroblasts cell line (3T3 was used to assess the cytotoxicity activity of AzA and AzA derivative, which is dilaurylazelate ester. The comparison of the IC50 (50% inhibition of cell viability value for AzA and AzA derivative was demonstrated. The IC50 value for AzA was 85.28 μg/mL, whereas the IC50 value for AzA derivative was more than 100 μg/mL. The 3T3 cell was still able to survive without any sign of toxicity from the AzA derivative; thus, it was proven to be non-toxic in this MTT assay when compared with AzA.

  2. Anisotropic surface hole-transport property of triphenylamine-derivative single crystal prepared by solution method

    Energy Technology Data Exchange (ETDEWEB)

    Umeda, Minoru, E-mail: mumeda@vos.nagaokaut.ac.jp [Nagaoka University of Technology, Kamitomioka, Nagaoka, Niigata 940-2188 (Japan); Katagiri, Mitsuhiko; Shironita, Sayoko [Nagaoka University of Technology, Kamitomioka, Nagaoka, Niigata 940-2188 (Japan); Nagayama, Norio [Nagaoka University of Technology, Kamitomioka, Nagaoka, Niigata 940-2188 (Japan); Ricoh Company, Ltd., Nishisawada, Numazu, Shizuoka 410-0007 (Japan)

    2016-12-01

    Highlights: • A hole transport molecule was investigated based on its electrochemical redox characteristics. • The solubility and supersolubility curves of the molecule were measured in order to prepare a large crystal. • The polarization micrograph and XRD results revealed that a single crystal was obtained. • An anisotropic surface conduction, in which the long-axis direction exceeds that of the amorphous layer, was observed. • The anisotropic surface conduction was well explained by the molecular stacked structure. - Abstract: This paper reports the anisotropic hole transport at the triphenylamine-derivative single crystal surface prepared by a solution method. Triphenylamine derivatives are commonly used in a hole-transport material for organic photoconductors of laser-beam printers, in which the materials are used as an amorphous form. For developing organic photovoltaics using the photoconductor’s technology, preparation of a single crystal seems to be a specific way by realizing the high mobility of an organic semiconductor. In this study, a single crystal of 4-(2,2-diphenylethenyl)-N,N-bis(4-methylphenyl)-benzenamine (TPA) was prepared and its anisotropic hole-transport property measured. First, the hole-transport property of the TPA was investigated based on its chemical structure and electrochemical redox characteristics. Next, a large-scale single crystal formation at a high rate was developed by employing a solution method based on its solubility and supersolubility curves. The grown TPA was found to be a single crystal based on the polarization micrograph observation and crystallographic analysis. For the TPA single crystal, an anisotropic surface conduction was found, which was well explained by its molecular stack structure. The measured current in the long-axis direction is one order of magnitude greater than that of amorphous TPA.

  3. Continuous leaching modifies the surface properties and metal(loid) sorption of sludge-derived biochar.

    Science.gov (United States)

    Feng, Mingyu; Zhang, Weihua; Wu, Xueyong; Jia, Yanming; Jiang, Chixiao; Wei, Hang; Qiu, Rongliang; Tsang, Daniel C W

    2018-06-01

    After the application of sludge derived biochar (SDBC) for soil stabilization, it is subjected to continuous leaching that may change its surface properties and metal(loid) immobilization performance. This study simulated the continuous leaching through the fresh SDBC sample in columns with unsaturated and saturated zones under flushing with 0.01M NaNO 3 solution (pH5.5) and acidic solution (pH adjusted to 3.2 by HNO 3 :H 2 SO 4 =1:2), respectively. The resultant changes were assessed in terms of the SDBC surface characteristics and metal(loid) sorption capacities. Continuous leaching was found to gradually decrease the density of basic functional groups and increase the density of carboxyl groups as well as cation exchange capacity on the SDBC surface. It was attributed to the surface acidification and oxidation process by the leaching process, yet it occurred to a lesser extent than the atmospheric exposure. Continuous leaching increased Pb(II), Cr(VI), and As(III) sorption capacity of the SDBC, probably because the increase in carboxyl groups promoted inner-sphere complexation and Fe oxidation as revealed by spectroscopic analysis. It was noteworthy that the SDBC in the unsaturated and saturated zones under continuous leaching displayed distinctive effects on metal(loid) sorption capacity than the atmospheric exposure. Future investigations are needed for understanding the fate and interactions of the SDBC under varying redox conditions and intermittent leaching process. Copyright © 2017. Published by Elsevier B.V.

  4. Bioinspired superhydrophobic poly(L-lactic acid) surfaces control bone marrow derived cells adhesion and proliferation.

    Science.gov (United States)

    Alves, Natália M; Shi, Jun; Oramas, Elena; Santos, José L; Tomás, Helena; Mano, João F

    2009-11-01

    The aptitude of a cell to adhere, migrate, and differentiate on a compact substrate or scaffold is important in the field of tissue engineering and biomaterials. It is well known that cell behavior can be controlled and guided through the change in micro- and nano-scale topographic features. In this work, we intend to demonstrate that special topographic features that control wettability may also have an important role in the biological performance of biodegradable substrates. Poly(L-lactic acid) surfaces with superhydrophobic characteristics were produced, based on the so-called Lotus effect, exhibiting dual micro- and nano-scale roughness. The water contact angle could be higher than 150 degrees and a value of that order could be kept even upon immersion in a simulated body fluid solution for more than 20 days. Such water repellent surfaces were found to prevent adhesion and proliferation of bone marrow derived cells previously isolated from the femurs of 6-week-old male Wistar rats, when compared with smoother surfaces prepared by simple solvent casting. Such results demonstrate that these superhydrophobic surfaces may be used to control cell behavior onto biodegradable substrates. (c) 2008 Wiley Periodicals, Inc.

  5. RELATIONSHIP BETWEEN HEIGHT, SITTING HEIGHT AND SUBISCHIAL LEG LENGTH IN DUTCH CHILDREN - PRESENTATION OF NORMAL VALUES

    NARCIS (Netherlands)

    GERVER, WJM; DEBRUIN, R

    A widely used method of judging body proportions is to consider the ratio of sitting height to height (SH/H) related to age. A drawback of this method is that only one derived variable is used. A pairwise consideration of the original measurements provides more information. In this study data from

  6. UV and gamma irradiation effects on surface properties of polyurethane derivative from castor oil

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Elaine C.; Nascimento, Eduardo M., E-mail: helunica@yahoo.com.br [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Chierice, Gilberto O.; Claro Neto, Salvador [Universidade de Sao Paulo (IQSC/USP), Sao Carlos, SP (Brazil). Instituto de Quimica; Lepienski, Carlos M. [Universidade Federal do Parana (UFPR), Curitiba (Brazil)

    2013-07-01

    Gamma and ultraviolet radiation effects on hardness, elastic modulus and viscoelastic properties of polyurethane derived from castor oil (PU) were investigated by nanoindentation tests. Modifications on surface morphology, induce by radiation, were observed by atomic force microscopy. The polyurethane derivative from castor oil shows good resistance to gamma radiation, with only small changes in hardness, elastic modulus, viscoelastic properties and contact angle. The hardness of PY increases at the near surface region due to UVA radiation and decreases after UVC radiation. The contact angle for water drop decreases after UVC radiation, by not after gamma radiation, despite a significant increase in roughness. Such results are attributed to different responses from polyurethane to radiation energy. Increase in hardness due to UVA is attributed to a higher crosslinking at shallow depths, while a decrease in mechanical properties may be attributed to chain scission. These results are consistent with the modifications on viscoelastic properties. Shore D hardness did not show the same trend as observed by nanoindentation results. Hardness, viscoelastic properties and contact angle of castor oil polyurethane are more severely influenced by UVC radiation, while gamma radiation does not have a significant effect. (author)

  7. UV and gamma irradiation effects on surface properties of polyurethane derivative from castor oil

    International Nuclear Information System (INIS)

    Azevedo, Elaine C.; Nascimento, Eduardo M.; Chierice, Gilberto O.; Claro Neto, Salvador

    2013-01-01

    Gamma and ultraviolet radiation effects on hardness, elastic modulus and viscoelastic properties of polyurethane derived from castor oil (PU) were investigated by nanoindentation tests. Modifications on surface morphology, induce by radiation, were observed by atomic force microscopy. The polyurethane derivative from castor oil shows good resistance to gamma radiation, with only small changes in hardness, elastic modulus, viscoelastic properties and contact angle. The hardness of PY increases at the near surface region due to UVA radiation and decreases after UVC radiation. The contact angle for water drop decreases after UVC radiation, by not after gamma radiation, despite a significant increase in roughness. Such results are attributed to different responses from polyurethane to radiation energy. Increase in hardness due to UVA is attributed to a higher crosslinking at shallow depths, while a decrease in mechanical properties may be attributed to chain scission. These results are consistent with the modifications on viscoelastic properties. Shore D hardness did not show the same trend as observed by nanoindentation results. Hardness, viscoelastic properties and contact angle of castor oil polyurethane are more severely influenced by UVC radiation, while gamma radiation does not have a significant effect. (author)

  8. First Derivative UV Spectra of Surface Water as a Monitor of Chlorination in Drinking Water Treatment

    Directory of Open Access Journals (Sweden)

    V. Zitko

    2001-01-01

    Full Text Available Many countries require the presence of free chlorine at about 0.1 mg/l in their drinking water supplies. For various reasons, such as cast-iron pipes or long residence times in the distribution system, free chlorine may decrease below detection limits. In such cases it is important to know whether or not the water was chlorinated or if nonchlorinated water entered the system by accident. Changes in UV spectra of natural organic matter in lakewater were used to assess qualitatively the degree of chlorination in the treatment to produce drinking water. The changes were more obvious in the first derivative spectra. In lakewater, the derivative spectra have a maximum at about 280 nm. This maximum shifts to longer wavelengths by up to 10 nm, decreases, and eventually disappears with an increasing dose of chlorine. The water treatment system was monitored by this technique for over 1 year and changes in the UV spectra of water samples were compared with experimental samples treated with known amounts of chlorine. The changes of the UV spectra with the concentration of added chlorine are presented. On several occasions, water, which received very little or no chlorination, may have entered the drinking water system. The results show that first derivative spectra are potentially a tool to determine, in the absence of residual chlorine, whether or not surface water was chlorinated during the treatment to produce potable water.

  9. A comparison of optical and microwave scintillometers with eddy covariance derived surface heat fluxes

    KAUST Repository

    Yee, Mei Sun

    2015-11-01

    Accurate measurements of energy fluxes between land and atmosphere are important for understanding and modeling climatic patterns. Several methods are available to measure heat fluxes, and scintillometers are becoming increasingly popular because of their ability to measure sensible (. H) and latent (. LvE) heat fluxes over large spatial scales. The main motivation of this study was to test the use of different methods and technologies to derive surface heat fluxes.Measurements of H and LvE were carried out with an eddy covariance (EC) system, two different makes of optical large aperture scintillometers (LAS) and two microwave scintillometers (MWS) with different frequencies at a pasture site in a semi-arid environment of New South Wales, Australia. We used the EC measurements as a benchmark. Fluxes derived from the EC system and LAS systems agreed (R2>0.94), whereas the MWS systems measured lower H (bias ~60Wm-2) and larger LvE (bias ~65Wm-2) than EC. When the scintillometers were compared against each other, the two LASs showed good agreement of H (R2=0.98), while MWS with different frequencies and polarizations led to different results. Combination of LAS and MWS measurements (i.e., two wavelength method) resulted in performance that fell in between those estimated using either LAS or MWS alone when compared with the EC system. The cause for discrepancies between surface heat fluxes derived from the EC system and those from the MWS systems and the two-wavelength method are possibly related to inaccurate assignment of the structure parameter of temperature and humidity. Additionally, measurements from MWSs can be associated with two values of the Bowen ratio, thereby leading to uncertainties in the estimation of the fluxes. While only one solution has been considered in this study, when LvE was approximately less than 200Wm-2, the alternate solution may be more accurate. Therefore, for measurements of surface heat fluxes in a semi-arid or dry environment, the

  10. Massachusetts Bay - Internal wave packets digitized from SAR imagery and intersected with a bathymetrically derived slope surface

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This feature class contains internal wave packets digitized from SAR imagery and intersected with a bathymetrically derived slope surface for Massachusetts Bay. The...

  11. Derivation of activity limits for the disposal of radioactive waste in near surface disposal facilities

    International Nuclear Information System (INIS)

    2003-12-01

    criteria for disposal of radioactive wastes to near surface facilities. These criteria are qualitative in nature and, for example, they do not address limitations on radionuclide content of waste, waste packages or the facility as a whole. This publication is to present an approach for establishing radiological waste acceptance criteria using a safety assessment methodology and to illustrate its application in establishing limits on the total activity and the activity concentrations of radioactive waste to be disposed in near surface disposal facilities. The approach makes use of accepted methods and computational schemes currently used in assessing the safety of near surface disposal facilities both during the operational and post-closure periods. The scope of this publication covers the use of safety assessment methodology to calculate total and specific activities limits for radioactive waste in near surface disposal facilities. It is used to evaluate the potential operational and post-closure radiological impact of solid and solidified radioactive waste in near surface facilities. The radioactive waste types used to illustrate the approach range from waste containing radionuclides used for medical, industrial and research purposes to waste arising from nuclear fuel cycle activities. They also include waste arising from the decommissioning of nuclear facilities. The focus of the publication is on using of safety assessment methodology in derivation of quantitative radioactivity limits. This report deals with the role of activity limits in disposal system safety (Section 2), the relevant radiation protection criteria (Section 3), the approach to derive activity limits (Section 4), illustrations of the application of this approach (Section 5), and guidance on the use of the approach (Section 6)

  12. Does quality control matter? Surface urban heat island intensity variations estimated by satellite-derived land surface temperature products

    Science.gov (United States)

    Lai, Jiameng; Zhan, Wenfeng; Huang, Fan; Quan, Jinling; Hu, Leiqiu; Gao, Lun; Ju, Weimin

    2018-05-01

    The temporally regular and spatially comprehensive monitoring of surface urban heat islands (SUHIs) have been extremely difficult, until the advent of satellite-based land surface temperature (LST) products. However, these LST products have relatively higher errors compared to in situ measurements. This has resulted in comparatively inaccurate estimations of SUHI indicators and, consequently, may have distorted interpretations of SUHIs. Although reports have shown that LST qualities are important for SUHI interpretations, systematic investigations of the response of SUHI indicators to LST qualities across cities with dissimilar bioclimates are rare. To address this issue, we chose eighty-six major cities across mainland China and analyzed SUHI intensity (SUHII) derived from Moderate Resolution Imaging Spectroradiometer (MODIS) LST data. The LST-based SUHII differences due to inclusion or exclusion of MODIS quality control (QC) flags (i.e., ΔSUHII) were evaluated. Our major findings included, but are not limited to, the following four aspects: (1) SUHIIs can be significantly impacted by MODIS QC flags, and the associated QC-induced ΔSUHIIs generally accounted for 24.3% (29.9%) of the total SUHII value during the day (night); (2) the ΔSUHIIs differed between seasons, with considerable differences between transitional (spring and autumn) and extreme (summer and winter) seasons; (3) significant discrepancies also appeared among cities located in northern and southern regions, with northern cities often possessing higher annual mean ΔSUHIIs. The internal variations of ΔSUHIIs within individual cities also showed high heterogeneity, with ΔSUHII variations that generally exceeded 5.0 K (3.0 K) in northern (southern) cities; (4) ΔSUHIIs were negatively related to SUHIIs and cloud cover percentages (mostly in transitional seasons). No significant relationship was found in the extreme seasons. Our findings highlight the need to be extremely cautious when using LST

  13. Spatially Complete Global Surface Albedos Derived from Terra/MODIS Data

    Science.gov (United States)

    King, Michael D.; Moody, Eric G.; Schaaf, Crystal B.; Platnick, Steven

    2006-01-01

    Spectral land surface albedo is an important parameter for describing the radiative properties of the Earth. Accordingly it reflects the consequences of natural and human interactions, such as anthropogenic, meteorological, and phenological effects, on global and local climatological trends. Consequently, albedos are integral parts in a variety of research areas, such as general circulation models (GCMs), energy balance studies, modeling of land use and land use change, and biophysical, oceanographic, and meteorological studies. , Over five years of land surface anisotropy, diffuse bihemispherical (white-sky) albedo and direct beam directional hemispherical (black-sky) albedo from observations acquired by the MODIS instruments aboard NASA s Terra and Aqua satellite platforms have provided researchers with unprecedented spatial, spectral, and temporal information on the land surface s radiative characteristics. However, roughly 30% of the global land surface, on an annual equal-angle basis, is obscured due to persistent and transient cloud cover, while another 207% is obscured due to ephemeral and seasonal snow effects. This precludes the MOD43B3 albedo products from being directly used in some remote sensing and ground-based applications, climate models, and global change research projects. To provide researchers with the requisite spatially complete global snow-free land surface albedo dataset, an ecosystem-dependent temporal interpolation technique was developed to fill missing or lower quality data and snow covered values from the official MOD43B3 dataset with geophysically realistic values. The method imposes pixel-level and local regional ecosystem-dependent phenological behavior onto retrieved pixel temporal data in such a way as to maintain pixel-level spatial and spectral detail and integrity. The phenological curves are derived from statistics based on the MODIS MOD12Q1 IGBP land cover classification product geolocated with the MOD43B3 data.

  14. 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.

  15. A Novel Fiber Optic Surface Plasmon Resonance Biosensors with Special Boronic Acid Derivative to Detect Glycoprotein

    Directory of Open Access Journals (Sweden)

    Yang Zhang

    2017-10-01

    Full Text Available We proposed and demonstrated a novel tilted fiber Bragg grating (TFBG-based surface plasmon resonance (SPR label-free biosensor via a special boronic acid derivative to detect glycoprotein with high sensitivity and selectivity. TFBG, as an effective sensing element for optical sensing in near-infrared wavelengths, possess the unique capability of easily exciting the SPR effect on fiber surface which coated with a nano-scale metal layer. SPR properties can be accurately detected by measuring the variation of transmitted spectra at optical communication wavelengths. In our experiment, a 10° TFBG coated with a 50 nm gold film was manufactured to stimulate SPR on a sensor surface. To detect glycoprotein selectively, the sensor was immobilized using designed phenylboronic acid as the recognition molecule, which can covalently bond with 1,2- or 1,3-diols to form five- or six-membered cyclic complexes for attaching diol-containing biomolecules and proteins. The phenylboronic acid was synthetized with long alkyl groups offering more flexible space, which was able to improve the capability of binding glycoprotein. The proposed TFBG-SPR sensors exhibit good selectivity and repeatability with a protein concentration sensitivity up to 2.867 dB/ (mg/mL and a limit of detection (LOD of 15.56 nM.

  16. Derivation and evaluation of land surface temperature from the geostationary operational environmental satellite series

    Science.gov (United States)

    Fang, Li

    The Geostationary Operational Environmental Satellites (GOES) have been continuously monitoring the earth surface since 1970, providing valuable and intensive data from a very broad range of wavelengths, day and night. The National Oceanic and Atmospheric Administration's (NOAA's) National Environmental Satellite, Data, and Information Service (NESDIS) is currently operating GOES-15 and GOES-13. The design of the GOES series is now heading to the 4 th generation. GOES-R, as a representative of the new generation of the GOES series, is scheduled to be launched in 2015 with higher spatial and temporal resolution images and full-time soundings. These frequent observations provided by GOES Image make them attractive for deriving information on the diurnal land surface temperature (LST) cycle and diurnal temperature range (DTR). These parameters are of great value for research on the Earth's diurnal variability and climate change. Accurate derivation of satellite-based LSTs from thermal infrared data has long been an interesting and challenging research area. To better support the research on climate change, the generation of consistent GOES LST products for both GOES-East and GOES-West from operational dataset as well as historical archive is in great demand. The derivation of GOES LST products and the evaluation of proposed retrieval methods are two major objectives of this study. Literature relevant to satellite-based LST retrieval techniques was reviewed. Specifically, the evolution of two LST algorithm families and LST retrieval methods for geostationary satellites were summarized in this dissertation. Literature relevant to the evaluation of satellite-based LSTs was also reviewed. All the existing methods are a valuable reference to develop the GOES LST product. The primary objective of this dissertation is the development of models for deriving consistent GOES LSTs with high spatial and high temporal coverage. Proper LST retrieval algorithms were studied

  17. A Critical Evaluation of High TEX86-derived Sea Surface Temperatures from the Early Eocene

    Science.gov (United States)

    Pancost, R. D.; Taylor, K. W.; Handley, L.; Huber, M.; Hollis, C. J.

    2011-12-01

    The application of glycerol dialkyl glycerol tetraether (GDGT) based sea surface temperature proxies (eg TEX-86) has brought about major advances in our understanding of Cenozoic climate. However, TEX-86 approaches yield high temperatures at high latitudes during the EECO, and the resulting low latitudinal temperature gradients challenge our understanding of the physical climate system. We examine existing Paleogene TEX-86 data using three approaches. First, we have compared TEX-86 SST estimates to those derived from oxygen isotopes or Mg/Ca ratios of co-occurring well-preserved planktonic foraminifera. This reveals a strong correlation between foraminiferal SSTs and those obtained from linear TEX-86 calibrations, but the latter are systematically 4-6°C warmer. SSTs derived from non-linear TEX-86 calibrations are similar to inorganic SST estimates at high temperatures, but an offset still persists at lower temperatures. We have also compared TEX-86 SST estimates from marginal settings to associated continental mean air temperatures (MAT) derived from soil bacterial GDGTs (the MBT/CBT index). Again, the two approaches exhibit a strong correlation but with the former yielding 4-6°C warmer temperatures. Second, we have developed SST records from New Zealand, in order to place the EECO SSTs into a longer-term Paleogene context. Our temperature estimates indicate that sea floor and sea surface temperatures increased by ~10°C from late Paleocene to early Eocene times. Late Paleocene TEX-86-derived SSTs for the Canterbury Basin range from 18 to 23°C, consistent with coeval TEX-86 records from the Campbell Plateau and south Tasman Sea. During the EECO, TEX-86 derived SSTs from the Canterbury Basin and south Tasman Sea indicate tropical conditions, with temperatures peaking at 30-32°C at 50 Ma and then declining to 24-26°C into the Middle Eocene. MBT/CBT-derived MATs broadly parallel the SST trends, albeit with slightly lower values. These records suggest that

  18. Сomposition and ratio of the chemical elements on the surfaces different by height of reindeer lichen podetia Cladonia rangiferina

    Directory of Open Access Journals (Sweden)

    Byazrov Lev

    2016-06-01

    Full Text Available In the paper the composition of 21 elements – Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Ba, Pb – was compared in the upper, central, and lower parts of podetia surfaces of the reindeer lichen Cladonia rangiferina, sampled on the slope of Barguzinsky chain. For the measurement of the elements content (%, a sample-nondestructive μ-XRF spectrometer was used. It was stated that the share (% of the most elements, except for Cu and Zn, was highly variable. The content of the elements on the surfaces differs significantly between the studied parts of C. rangiferina podetia: mean values of the content of P, S, Cl, and K were statistically higher on the surface of the upper part of podetia, while those of Al, Si, Ca, Ti, Cr, Mn, Fe, Cu, Zn, Co, and the total content – on the surface of the lower part of podetia. On all the parts of podetia very high value of the enrichment factor for As and Pb was established, and It was increased for P, Co, Ni, Cu, Zn.

  19. Derivation of the Wenzel and Cassie Equations from a Phase Field Model for Two Phase Flow on Rough Surface

    KAUST Repository

    Xu, Xianmin

    2010-01-01

    In this paper, the equilibrium behavior of an immiscible two phase fluid on a rough surface is studied from a phase field equation derived from minimizing the total free energy of the system. When the size of the roughness becomes small, we derive the effective boundary condition for the equation by the multiple scale expansion homogenization technique. The Wenzel and Cassie equations for the apparent contact angles on the rough surfaces are then derived from the effective boundary condition. The homogenization results are proved rigorously by the F-convergence theory. © 2010 Society for Industrial and Applied Mathematics.

  20. Derivation of Waste Acceptance Criteria for Low and Intermediate Level Waste in Surface Disposal Facility

    International Nuclear Information System (INIS)

    Gagner, L.; Voinis, S.

    2000-01-01

    In France, low- and intermediate-level radioactive wastes are disposed in a near-surface facility, at Centre de l'Aube disposal facility. This facility, which was commissioned in 1992, has a disposal capacity of one million cubic meters, and will be operated up to about 2050. It took over the job from Centre de la Manche, which was commissioned in 1969 and shut down in 1994, after having received about 520,000 cubic meters of wastes. The Centre de l'Aube disposal facility is designed to receive a many types of waste produced by nuclear power plants, reprocessing, decommissioning, as well as by the industry, hospitals and armed forces. The limitation of radioactive transfer to man and the limitation of personnel exposure in all situations considered plausible require limiting the total activity of the waste disposed in the facility as well as the activity of each package. The paper presents how ANDRA has derived the activity-related acceptance criteria, based on the safety analysis. In the French methodology, activity is considered as end-point for deriving the concentration limits per package, whereas it is the starting point for deriving the total activity limits. For the concentration limits (called here LMA) the approach consists of five steps: the determination of radionuclides important for safety with regards to operational and long-term safety, the use of relevant safety scenarios as a tool to derive quantitative limits, the setting of dose constraint per situation associated with scenarios, the setting of contribution factor per radionuclide, and the calculation of concentration activity limits. An exhaustive survey has been performed and has shown that the totality of waste packages which should be delivered by waste generators are acceptable in terms of activity limits in the Centre de l'Aube. Examples of concentration activity limits derived from this methodology are presented. Furthermore those limits have been accepted by the French regulatory body and

  1. Validation of AVHRR- and MODIS-derived albedos of snow and ice surfaces by means of helicopter measurements

    NARCIS (Netherlands)

    Greuell, W.; Oerlemans, J.

    2005-01-01

    We describe the validation of surface albedos of snow and glacier ice as derived from Advanced Very High Resolution Radiometer (AVHRR) and MOderate Resolution Imaging Spectrometer (MODIS) satellite data. For this purpose we measured surface albedos from a helicopter over Vatnajökull, Iceland, and

  2. The influence of the segmentation process on 3D measurements from cone beam computed tomography-derived surface models

    NARCIS (Netherlands)

    Engelbrecht, Willem P.; Fourie, Zacharias; Damstra, Janalt; Gerrits, Peter O.; Ren, Yijin

    2013-01-01

    To compare the accuracy of linear and angular measurements between cephalometric and anatomic landmarks on surface models derived from 3D cone beam computed tomography (CBCT) with two different segmentation protocols was the aim of this study. CBCT scans were made of cadaver heads and 3D surface

  3. Assessment of the surface mass balance along the K-transect (Greenland ice sheet) from satellite-derived albedos

    NARCIS (Netherlands)

    Oerlemans, J.; Greuell, W.

    This paper explores the potential of using satellite-derived albedos to estimate the surface mass balance of the Kangerlussuaq transect (K-transect; Greenland ice sheet). We first retrieved surface albedos from Advanced Very High Resolution Radar data by using, among other techniques, a new

  4. Electrochemical surface derivation of glassy carbon by the reduction of triaryl- and alkyldiphenylsulfonium salts

    DEFF Research Database (Denmark)

    Vase, K.H.; Holm, A.H.; Norrman, Kion

    2008-01-01

    The range of materials susceptible to electrochemically assisted grafting onto carbon materials has been expanded to include a new group of compounds. This new approach is based on the reduction of symmetrical or unsymmetrical triarylsulfonium salts and alkyldiphenylsulfonium salts. Our findings......, the alkyldiphenylsulfonium salts are found to cleave almost exclusively to an alkyl radical and diphenyl sulfide. As judged from the electrochemical blocking properties of the films made from such species, either relatively thick or compact films are formed. The mass spectrometric analysis indicates that the films are made...... of a combination of alkyl and aryl groups and possibly related structural derivatives. Importantly, our findings provide evidence that it is possible to graft electrode surfaces with reactive aryl radicals even using precursors reduced at potentials that are substantially more negative than the estimated reduction...

  5. The extent of temporal smearing in surface-temperature histories derived from borehole temperature measurements

    Science.gov (United States)

    Clow, G.D.

    1992-01-01

    The ability of borehole temperature data to resolve past climatic events is investigated using Backus-Gilbert inversion methods. Two experimental approaches are considered: (1) the data consist of a single borehole temperature profile, and (2) the data consist of climatically-induced temperature transients measured within a borehole during a monitoring experiment. The sensitivity of the data's resolving power to the vertical distribution of the measurements, temperature measurement errors, the inclusion of a local meteorological record, and the duration of a monitoring experiment, are investigated. The results can be used to help interpret existing surface temperature histories derived from borehole temperature data and to optimize future experiments for the detection of climatic signals. ?? 1992.

  6. JVG9, a benzimidazole derivative, alters the surface and cytoskeleton of Trypanosoma cruzi bloodstream trypomastigotes.

    Science.gov (United States)

    Díaz-Chiguer, Dylan L; Hernández-Luis, Francisco; Nogueda-Torres, Benjamín; Castillo, Rafael; Reynoso-Ducoing, Olivia; Hernández-Campos, Alicia; Ambrosio, Javier R

    2014-09-01

    Trypanosoma cruzi has a particular cytoskeleton that consists of a subpellicular network of microtubules and actin microfilaments. Therefore, it is an excellent target for the development of new anti-parasitic drugs. Benzimidazole 2-carbamates, a class of well-known broad-spectrum anthelmintics, have been shown to inhibit the in vitro growth of many protozoa. Therefore, to find efficient anti-trypanosomal (trypanocidal) drugs, our group has designed and synthesised several benzimidazole derivatives. One, named JVG9 (5-chloro-1H-benzimidazole-2-thiol), has been found to be effective against T. cruzi bloodstream trypomastigotes under both in vitro and in vivo conditions. Here, we present the in vitro effects observed by laser scanning confocal and scanning electron microscopy on T. cruzi trypomastigotes. Changes in the surface and the distribution of the cytoskeletal proteins are consistent with the hypothesis that the trypanocidal activity of JVG9 involves the cytoskeleton as a target.

  7. JVG9, a benzimidazole derivative, alters the surface and cytoskeleton of Trypanosoma cruzi bloodstream trypomastigotes

    Directory of Open Access Journals (Sweden)

    Dylan L Díaz-Chiguer

    2014-09-01

    Full Text Available Trypanosoma cruzi has a particular cytoskeleton that consists of a subpellicular network of microtubules and actin microfilaments. Therefore, it is an excellent target for the development of new anti-parasitic drugs. Benzimidazole 2-carbamates, a class of well-known broad-spectrum anthelmintics, have been shown to inhibit the in vitro growth of many protozoa. Therefore, to find efficient anti-trypanosomal (trypanocidal drugs, our group has designed and synthesised several benzimidazole derivatives. One, named JVG9 (5-chloro-1H-benzimidazole-2-thiol, has been found to be effective against T. cruzi bloodstream trypomastigotes under both in vitro and in vivo conditions. Here, we present the in vitro effects observed by laser scanning confocal and scanning electron microscopy on T. cruzi trypomastigotes. Changes in the surface and the distribution of the cytoskeletal proteins are consistent with the hypothesis that the trypanocidal activity of JVG9 involves the cytoskeleton as a target.

  8. Mechanistic insights into landscape genetic structure of two tropical amphibians using field-derived resistance surfaces.

    Science.gov (United States)

    Nowakowski, A Justin; DeWoody, J Andrew; Fagan, Matthew E; Willoughby, Janna R; Donnelly, Maureen A

    2015-02-01

    Conversion of forests to agriculture often fragments distributions of forest species and can disrupt gene flow. We examined effects of prevalent land uses on genetic connectivity of two amphibian species in northeastern Costa Rica. We incorporated data from field surveys and experiments to develop resistance surfaces that represent local mechanisms hypothesized to modify dispersal success of amphibians, such as habitat-specific predation and desiccation risk. Because time lags can exist between forest conversion and genetic responses, we evaluated landscape effects using land-cover data from different time periods. Populations of both species were structured at similar spatial scales but exhibited differing responses to landscape features. Litter frog population differentiation was significantly related to landscape resistances estimated from abundance and experiment data. Model support was highest for experiment-derived surfaces that represented responses to microclimate variation. Litter frog genetic variation was best explained by contemporary landscape configuration, indicating rapid population response to land-use change. Poison frog genetic structure was strongly associated with geographic isolation, which explained up to 45% of genetic variation, and long-standing barriers, such as rivers and mountains. However, there was also partial support for abundance- and microclimate response-derived resistances. Differences in species responses to landscape features may be explained by overriding effects of population size on patterns of differentiation for poison frogs, but not litter frogs. In addition, pastures are likely semi-permeable to poison frog gene flow because the species is known to use pastures when remnant vegetation is present, but litter frogs do not. Ongoing reforestation efforts will probably increase connectivity in the region by increasing tree cover and reducing area of pastures. © 2014 John Wiley & Sons Ltd.

  9. Validation of Satellite-Derived Sea Surface Temperatures for Waters around Taiwan

    Directory of Open Access Journals (Sweden)

    Ming-An Lee

    2005-01-01

    Full Text Available In order to validate the Advanced Very High Resolution Radiometer (AVHRR-derived sea surface temperatures (SST of the waters around Taiwan, we generated a match-up data set of 961 pairs, which included in situ SSTs and concurrent AVHRR measurements for the period of 1998 to 2002. Availability of cloud-free images, i.e., images with more than 85% of cloud-free area in their coverage, was about 2.23% of all AVHRR images during the study period. The range of in situ SSTs was from _ to _ The satellite derived-SSTs through MCSST and NLSST algorithms were linearly related to the in situ SSTs with correlation coefficients of 0.985 and 0.98, respectively. The MCSSTs and NLSSTs had small biases of 0.009 _ and 0.256 _ with root mean square deviations of 0.64 _ and 0.801 _ respectively, therefore the AVHRR-based MCSSTs and NLSSTs had high accuracy in the seas around Taiwan.

  10. Atmospherically derived organic surface films along an urban-rural gradient.

    Science.gov (United States)

    Gingrich, S E; Diamond, M L; Stern, G A; McCarry, B E

    2001-10-15

    Atmospherically derived organic films have been found on an impervious surface along an urban-rural gradient in the Toronto, Ontario, Canada area. Film thickness and concentrations, expressed on an aerial basis, of sigman-alkanes, sigmaPCB, sigmaPAH, and sigmaOC (organochlorine) pesticides decrease along this gradient, coincident with lower atmospheric emissions (PCB and PAH) and less accumulation in thinner rural films (OC pesticides). For PCBs and some OC pesticides, patterns of chemical abundance also shift, indicating a "fresh" pattern near emission sources (downtown) versus aged patterns at rural locations that are indicative of atmospheric transport. Plant-derived n-alkane concentrations were greater at urban than rural sites, and we hypothesize greater urban plant wax production and erosion due to air pollution. As expected, along the urban-rural gradient the concentration of particle-phase PAH decreased more rapidly than that of gas-phase compounds, but unexpectedly the contribution of alkylated PAH increased from urban to rural locations. Distances over which concentrations decline by 63% vary from 50 km for persistent gas-phase compounds (e.g., P1,2CB) to 10-20 km for reactive gas-phase compounds (e.g., naphthalene, fluoranthene) to particle-phase compounds (e.g., P6-10CB, benzo[b]fluoranthene, benzo[e]pyrene).

  11. Holographic recording of surface relief gratings in stilbene azobenzene derivatives at 633 nm

    Energy Technology Data Exchange (ETDEWEB)

    Ozols, A; Saharov, D; Kokars, V; Kampars, V; Maleckis, A; Mezinskis, G; Pludons, A, E-mail: aozols@latnet.l [Faculty of Material Science and Applied Chemistry, Riga Technical University, Azenes iela 14/24, LV-1048, Riga (Latvia)

    2010-11-01

    Holographic recording in stilbene azobenzene derivatives by He-Ne 633 nm laser light has been experimentally studied. It was found that surface relief gratings (SRG) can be recorded by red light. Usually shorter wavelengths are used to induce the trans-cis photo-isomerization in organic materials. SRG with 2 {mu}m period and an amplitude of 130 nm have been recorded with 0.88 W/cm{sup 2} light in about 20 minutes in amorphous films of 3-(4-(bis(2-(trityloxy)ethyl)amino)phenyl)-2-(4-(2-bromo-4-nitrophenyl) diazenyl)phenyl)acrylonitrile spin-coated on glass substrates. Self-diffraction efficiency up to 17.4% and specific recording energy down to 114 J/(cm{sup 2}%) were measured. The recorded SRG were stable as proved by subsequent AFM measurements. The photo-induced changes in absorption spectra did not reveal noticeable signs of trans-cis transformations. Rather, spectrally uniform bleaching of the films took place. We conclude that a photothermally stimulated photo-destruction of chromophores is responsible for the SRG recording. The recording of stable SRG in the stilbene azobenzene derivatives we studied is accompanied by the recording of relaxing volume-phase gratings due to the photo-orientation of chromophores by the linearly polarized recording light. It should also be noted that holographic recording efficiency in stilbene azobenzene derivatives exhibit an unusual non-monotonic sample storage-time dependence presumably caused by the peculiarities of structural relaxation of the films.

  12. Comparing land surface phenology derived from satellite and GPS network microwave remote sensing.

    Science.gov (United States)

    Jones, Matthew O; Kimball, John S; Small, Eric E; Larson, Kristine M

    2014-08-01

    The land surface phenology (LSP) start of season (SOS) metric signals the seasonal onset of vegetation activity, including canopy growth and associated increases in land-atmosphere water, energy and carbon (CO2) exchanges influencing weather and climate variability. The vegetation optical depth (VOD) parameter determined from satellite passive microwave remote sensing provides for global LSP monitoring that is sensitive to changes in vegetation canopy water content and biomass, and insensitive to atmosphere and solar illumination constraints. Direct field measures of canopy water content and biomass changes desired for LSP validation are generally lacking due to the prohibitive costs of maintaining regional monitoring networks. Alternatively, a normalized microwave reflectance index (NMRI) derived from GPS base station measurements is sensitive to daily vegetation water content changes and may provide for effective microwave LSP validation. We compared multiyear (2007-2011) NMRI and satellite VOD records at over 300 GPS sites in North America, and their derived SOS metrics for a subset of 24 homogenous land cover sites to investigate VOD and NMRI correspondence, and potential NMRI utility for LSP validation. Significant correlations (P<0.05) were found at 276 of 305 sites (90.5 %), with generally favorable correspondence in the resulting SOS metrics (r (2)=0.73, P<0.001, RMSE=36.8 days). This study is the first attempt to compare satellite microwave LSP metrics to a GPS network derived reflectance index and highlights both the utility and limitations of the NMRI data for LSP validation, including spatial scale discrepancies between local NMRI measurements and relatively coarse satellite VOD retrievals.

  13. Influence of the surface quality due to a hole derived in initial material processing of cold sheets with drawing

    OpenAIRE

    Cvetkov, Slavco; Kocov, Atanas

    2010-01-01

    A research was performed about the influence of the surface quality due to a hole derived in initial material processing of cold-rolled steel sheets with drawing. This influence was researched through the surface quality obtained bu the type of preparation of the hole surface without prejudice to the precise measurement of the achieved quality (asperity). the aim is to indicate how the type of manufacturing the holes can improve the workability of cold-rolled sheets and help solve technical p...

  14. Components of near-surface energy balance derived from satellite soundings – Part 1: Net available energy

    OpenAIRE

    K. Mallick; A. Jarvis; G. Wohlfahrt; G. Kiely; T. Hirano; A. Miyata; S. Yamamoto; L. Hoffmann

    2014-01-01

    This paper introduces a relatively simple method for recovering global fields of near-surface net available energy (the sum of the sensible and latent heat flux or the difference between the net radiation and surface heat accumulation) using satellite visible and infra-red products derived from the AIRS (Atmospheric Infrared Sounder) and MODIS (MOderate Resolution Imaging Spectroradiometer) platforms. The method focuses on first specifying net surface radiation by con...

  15. Surface mineral maps of Afghanistan derived from HyMap imaging spectrometer data, version 2

    Science.gov (United States)

    Kokaly, Raymond F.; King, Trude V.V.; Hoefen, Todd M.

    2013-01-01

    This report presents a new version of surface mineral maps derived from HyMap imaging spectrometer data collected over Afghanistan in the fall of 2007. This report also describes the processing steps applied to the imaging spectrometer data. The 218 individual flight lines composing the Afghanistan dataset, covering more than 438,000 square kilometers, were georeferenced to a mosaic of orthorectified Landsat images. The HyMap data were converted from radiance to reflectance using a radiative transfer program in combination with ground-calibration sites and a network of cross-cutting calibration flight lines. The U.S. Geological Survey Material Identification and Characterization Algorithm (MICA) was used to generate two thematic maps of surface minerals: a map of iron-bearing minerals and other materials, which have their primary absorption features at the shorter wavelengths of the reflected solar wavelength range, and a map of carbonates, phyllosilicates, sulfates, altered minerals, and other materials, which have their primary absorption features at the longer wavelengths of the reflected solar wavelength range. In contrast to the original version, version 2 of these maps is provided at full resolution of 23-meter pixel size. The thematic maps, MICA summary images, and the material fit and depth images are distributed in digital files linked to this report, in a format readable by remote sensing software and Geographic Information Systems (GIS). The digital files can be downloaded from http://pubs.usgs.gov/ds/787/downloads/.

  16. 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

  17. Water surface temperature profiles for the Rhine River derived from Landsat ETM+ data

    Science.gov (United States)

    Fricke, Katharina; Baschek, Björn

    2013-10-01

    Water temperature influences physical and chemical parameters of rivers and streams and is an important parameter for water quality. It is a crucial factor for the existence and the growth of animal and plant species in the river ecosystem. The aim of the research project "Remote sensing of water surface temperature" at the Federal Institute of Hydrology (BfG), Germany, is to supplement point measurements of water temperature with remote sensing methodology. The research area investigated here is the Upper and Middle Rhine River, where continuous measurements of water temperature are already available for several water quality monitoring stations. Satellite imagery is used to complement these point measurements and to generate longitudinal temperature profiles for a better systematic understanding of the changes in river temperature along its course. Several products for sea surface temperature derived from radiances in the thermal infrared are available, but for water temperature from rivers less research has been carried out. Problems arise from the characteristics of the river valley and morphology and the proximity to the riverbank. Depending on the river width, a certain spatial resolution of the satellite images is necessary to allow for an accurate identification of the river surface and the calculation of water temperature. The bands from the Landsat ETM+ sensor in the thermal infrared region offer a possibility to extract the river surface temperatures (RST) of a sufficiently wide river such as the Rhine. Additionally, problems such as cloud cover, shadowing effects, georeferencing errors, different emissivity of water and land, scattering of thermal radiation, adjacency and mixed pixel effects had to be accounted for and their effects on the radiance temperatures will be discussed. For this purpose, several temperature data sets derived from radiance and in situ measurements were com- pared. The observed radiance temperatures are strongly influenced by

  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. 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 ...

  20. High-Resolution Forest Canopy Height Estimation in an African Blue Carbon Ecosystem

    Science.gov (United States)

    Lagomasino, David; Fatoyinbo, Temilola; Lee, Seung-Kuk; Simard, Marc

    2015-01-01

    Mangrove forests are one of the most productive and carbon dense ecosystems that are only found at tidally inundated coastal areas. Forest canopy height is an important measure for modeling carbon and biomass dynamics, as well as land cover change. By taking advantage of the flat terrain and dense canopy cover, the present study derived digital surface models (DSMs) using stereophotogrammetric techniques on high-resolution spaceborne imagery (HRSI) for southern Mozambique. A mean-weighted ground surface elevation factor was subtracted from the HRSI DSM to accurately estimate the canopy height in mangrove forests in southern Mozambique. The mean and H100 tree height measured in both the field and with the digital canopy model provided the most accurate results with a vertical error of 1.18-1.84 m, respectively. Distinct patterns were identified in the HRSI canopy height map that could not be discerned from coarse shuttle radar topography mission canopy maps even though the mode and distribution of canopy heights were similar over the same area. Through further investigation, HRSI DSMs have the potential of providing a new type of three-dimensional dataset that could serve as calibration/validation data for other DSMs generated from spaceborne datasets with much larger global coverage. HSRI DSMs could be used in lieu of Lidar acquisitions for canopy height and forest biomass estimation, and be combined with passive optical data to improve land cover classifications.

  1. Investigating Land Surface Phenology Derived from Satellite and GPS Network Microwave Remote Sensing

    Science.gov (United States)

    Jones, M. O.; Kimball, J. S.; Small, E. E.; Larson, K. M.

    2013-12-01

    The land surface phenology (LSP) start of season (SOS) metric signals the seasonal onset of vegetation activity, including canopy growth and associated increases in land-atmosphere water, energy and carbon (CO2) exchanges influencing weather and climate variability. The Vegetation Optical Depth (VOD) parameter determined from satellite passive microwave remote sensing provides for global LSP monitoring that is sensitive to changes in vegetation canopy water content and biomass, and insensitive to atmosphere and solar illumination constraints. Direct field measures of canopy water content and biomass changes desired for LSP validation are generally lacking due to prohibitive costs of maintaining regional monitoring networks. Alternatively, a Normalized Microwave Reflectance Index (NMRI) derived from GPS base station measurements is sensitive to daily vegetation water content changes and may provide for effective microwave LSP validation as a relatively high spatial (1000m2) and temporal resolution vegetation phenology measure. We compared NMRI (1.2 and 1.5 GHz) and satellite microwave (AMSR-E sensor) 18.7 GHz frequency VOD records (2007 to 2011) at over 300 GPS sites in North America and their derived SOS metrics for a subset of 24 homogenous land cover sites. Significant correlations were found at 276 of 305 sites, with generally favorable correspondence in the resulting SOS metrics. We also investigated the temporal dynamics of nine NMRI sites within a single 25km resolution VOD pixel and with corresponding 250m MODIS NDVI measures of the three dominant land covers within the pixel to assess the spatial scale discrepancies between these high, moderate, and coarse resolution retrievals. This study is the first attempt to compare satellite microwave LSP metrics to a GPS network derived reflectance index and highlights both the utility and limitations of the NMRI data for LSP validation. Integration of GPS base stations and the NMRI into current phenology observation

  2. Deriving aerosol properties from measurements of the Atmosphere-Surface Radiation Automatic Instrument (ASRAI)

    Science.gov (United States)

    Xu, Hua; Li, Donghui; Li, Zhengqiang; Zheng, Xiaobing; Li, Xin; Xie, Yisong; Liu, Enchao

    2015-10-01

    The Atmosphere-surface Radiation Automatic Instrument (ASRAI) is a newly developed hyper-spectral apparatus by Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences (AIOFM, CAS), measuring total spectral irradiance, diffuse spectral irradiance of atmosphere and reflected radiance of the land surface for the purpose of in-situ calibration. The instrument applies VIS-SWIR spectrum (0.4~1.0 μm) with an averaged spectral resolution of 0.004 μm. The goal of this paper is to describe a method of deriving both aerosol optical depth (AOD) and aerosol modes from irradiance measurements under free cloudy conditions. The total columnar amounts of water vapor and oxygen are first inferred from solar transmitted irradiance at strong absorption wavelength. The AOD together with total columnar amounts of ozone and nitrogen dioxide are determined by a nonlinear least distance fitting method. Moreover, it is able to infer aerosol modes from the spectral dependency of AOD because different aerosol modes have their inherent spectral extinction characteristics. With assumption that the real aerosol is an idea of "external mixing" of four basic components, dust-like, water-soluble, oceanic and soot, the percentage of volume concentration of each component can be retrieved. A spectrum matching technology based on Euclidean-distance method is adopted to find the most approximate combination of components. The volume concentration ratios of four basic components are in accordance with our prior knowledge of regional aerosol climatology. Another advantage is that the retrievals would facilitate the TOA simulation when applying 6S model for satellite calibration.

  3. Surface Activity Distributions of Comet 67P/Churyumov-Gerasimenko Derived from VIRTIS Images

    Science.gov (United States)

    Fougere, Nicolas; Combi, Michael R.; Tenishev, Valeriy; Migliorini, Alessandra; Bockelee-Morvan, Dominique; Fink, Uwe; Filacchione, Gianrico; Rinaldi, Giovanna; Capaccioni, Fabrizio; Toth, Gabor; Gombosi, T. I.; Hansen, Kenneth C.; Huang, Zhenguang; Shou, Yinsi; VIRTIS Team

    2017-10-01

    The outgassing mechanism of comets still remains a critical question to better understand these objects. The Rosetta mission gave some insight regarding the potential activity distribution from the surface of the nucleus of comet 67P/Churyumov-Gerasimenko, Fougere et al. (2016, Astronomy & Astrophysics, Volume 588, id.A134, 11 pp and Monthly Notices of the Royal Astronomical Society, Volume 462, Issue Suppl_1, p.S156-S169) used a spherical harmonics inversion scheme with in-situ measurements from the ROSINA instrument to derive mapping of the broad distribution of potential activity at the surface of the nucleus. Marschall et al. (2016, Astronomy & Astrophysics, doi: 10.1051/0004-6361/201730849) based on the appearance of dust active areas suggested that the so-called “neck” region and regions with fractured cliffs and locally steep slopes show more activity than the rest of comet 67P’s nucleus. Using in situ ROSINA measurements from a distance makes it difficult to distinguish between these two scenarios because the fast expansion of the gas and large molecular mean free paths prevents distinguishing small outgassing features even when the spacecraft was in bound orbits within 10 km from the nucleus. In this paper, we present a similar numerical inversion approach using VIRTIS images, which should better probe the very inner coma of comet 67P and give more detailed information about the outgassing activity. Support from contracts JPL #1266314 and #1266313 from the US Rosetta Project and grant NNX14AG84G from the NASA Planetary Atmospheres Program are gratefully acknowledged.

  4. Influence of Light Emitting Diode-Derived Blue Light Overexposure on Mouse Ocular Surface.

    Science.gov (United States)

    Lee, Hyo Seok; Cui, Lian; Li, Ying; Choi, Ji Suk; Choi, Joo-Hee; Li, Zhengri; Kim, Ga Eon; Choi, Won; Yoon, Kyung Chul

    2016-01-01

    To investigate the influence of overexposure to light emitting diode (LED)-derived light with various wavelengths on mouse ocular surface. LEDs with various wavelengths were used to irradiate C57BL/6 mice at an energy dose of 50 J/cm2, twice a day, for 10 consecutive days. The red, green, and blue groups represented wavelengths of 630 nm, 525 nm, and 410 nm, respectively. The untouched group (UT) was not exposed to LED light and served as the untreated control. Tear volume, tear film break-up time (TBUT), and corneal fluorescein staining scores were measured on days 1, 3, 5, 7, and 10. Levels of interferon (IFN)-γ, interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α were measured in the cornea and conjunctiva using a multiplex immunobead assay at day 10. Levels of malondialdehyde (MDA) were measured with an enzyme-linked immunosorbent assay. Flow cytometry, 2'7'-dichlorofluorescein diacetate (DCF-DA) assay, histologic analysis, immunohistochemistry with 4-hydroxynonenal, and terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling (TUNEL) staining were also performed. TBUT of the blue group showed significant decreases at days 7 and 10, compared with the UT and red groups. Corneal fluorescein staining scores significantly increased in the blue group when compared with UT, red, and green groups at days 5, 7, and 10. A significant increase in the corneal levels of IL-1β and IL-6 was observed in the blue group, compared with the other groups. The blue group showed significantly increased reactive oxygen species production in the DCF-DA assay and increased inflammatory T cells in the flow cytometry. A significantly increased TUNEL positive cells was identified in the blue group. Overexposure to blue light with short wavelengths can induce oxidative damage and apoptosis to the cornea, which may manifest as increased ocular surface inflammation and resultant dry eye.

  5. Use of reflected GNSS SNR data to retrieve either soil moisture or vegetation height from a wheat crop

    Science.gov (United States)

    Zhang, Sibo; Roussel, Nicolas; Boniface, Karen; Ha, Minh Cuong; Frappart, Frédéric; Darrozes, José; Baup, Frédéric; Calvet, Jean-Christophe

    2017-09-01

    This work aims to estimate soil moisture and vegetation height from Global Navigation Satellite System (GNSS) Signal to Noise Ratio (SNR) data using direct and reflected signals by the land surface surrounding a ground-based antenna. Observations are collected from a rainfed wheat field in southwestern France. Surface soil moisture is retrieved based on SNR phases estimated by the Least Square Estimation method, assuming the relative antenna height is constant. It is found that vegetation growth breaks up the constant relative antenna height assumption. A vegetation-height retrieval algorithm is proposed using the SNR-dominant period (the peak period in the average power spectrum derived from a wavelet analysis of SNR). Soil moisture and vegetation height are retrieved at different time periods (before and after vegetation's significant growth in March). The retrievals are compared with two independent reference data sets: in situ observations of soil moisture and vegetation height, and numerical simulations of soil moisture, vegetation height and above-ground dry biomass from the ISBA (interactions between soil, biosphere and atmosphere) land surface model. Results show that changes in soil moisture mainly affect the multipath phase of the SNR data (assuming the relative antenna height is constant) with little change in the dominant period of the SNR data, whereas changes in vegetation height are more likely to modulate the SNR-dominant period. Surface volumetric soil moisture can be estimated (R2 = 0.74, RMSE = 0.009 m3 m-3) when the wheat is smaller than one wavelength (˜ 19 cm). The quality of the estimates markedly decreases when the vegetation height increases. This is because the reflected GNSS signal is less affected by the soil. When vegetation replaces soil as the dominant reflecting surface, a wavelet analysis provides an accurate estimation of the wheat crop height (R2 = 0.98, RMSE = 6.2 cm). The latter correlates with modeled above-ground dry

  6. Use of reflected GNSS SNR data to retrieve either soil moisture or vegetation height from a wheat crop

    Directory of Open Access Journals (Sweden)

    S. Zhang

    2017-09-01

    Full Text Available This work aims to estimate soil moisture and vegetation height from Global Navigation Satellite System (GNSS Signal to Noise Ratio (SNR data using direct and reflected signals by the land surface surrounding a ground-based antenna. Observations are collected from a rainfed wheat field in southwestern France. Surface soil moisture is retrieved based on SNR phases estimated by the Least Square Estimation method, assuming the relative antenna height is constant. It is found that vegetation growth breaks up the constant relative antenna height assumption. A vegetation-height retrieval algorithm is proposed using the SNR-dominant period (the peak period in the average power spectrum derived from a wavelet analysis of SNR. Soil moisture and vegetation height are retrieved at different time periods (before and after vegetation's significant growth in March. The retrievals are compared with two independent reference data sets: in situ observations of soil moisture and vegetation height, and numerical simulations of soil moisture, vegetation height and above-ground dry biomass from the ISBA (interactions between soil, biosphere and atmosphere land surface model. Results show that changes in soil moisture mainly affect the multipath phase of the SNR data (assuming the relative antenna height is constant with little change in the dominant period of the SNR data, whereas changes in vegetation height are more likely to modulate the SNR-dominant period. Surface volumetric soil moisture can be estimated (R2  =  0.74, RMSE  =  0.009 m3 m−3 when the wheat is smaller than one wavelength (∼ 19 cm. The quality of the estimates markedly decreases when the vegetation height increases. This is because the reflected GNSS signal is less affected by the soil. When vegetation replaces soil as the dominant reflecting surface, a wavelet analysis provides an accurate estimation of the wheat crop height (R2  =  0.98, RMSE  =  6

  7. 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)

  8. 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

  9. Synthesis, crystal structure, Hirshfeld surfaces analysis and anti-ischemic activity of cinnamide derivatives

    Science.gov (United States)

    Zhong, Jian-gang; Han, Jia-pei; Li, Xiao-feng; Xu, Yi; Zhong, Yan; Wu, Bin

    2018-02-01

    Two cinnamide derivatives, namely, (E)-1-(4-(bis(4-methylphenyl)- methyl)piperazin-1-yl)-3-(3,4-diethoxyphenyl)prop-2-en-1-one (5) and (E)-1-(4-(bis- (4-fluorophenyl)methyl)piperazin-1-yl)-3-(4-methoxyphenyl)prop-2-en-1-one (6), have been synthesized and characterized by IR spectra, High resolution mass spectra, 1H NMR spectra, 13C NMR spectra. The compound 5 is a novel compound and has never been reported in the literature. Their crystal structures were studied by single-crystal X-ray diffraction. They all crystallize in the monoclinic system. The single-crystal X-ray revealed that compound 5 has infinite X-shaped 1-D polymeric chains structure and compound 6 has a layered 3-D structure by intermolecular interactions. Hirshfeld surface analysis demonstrated the presence of H⋯H, O⋯H, C⋯H, F⋯H, Csbnd H⋯π and π⋯π intermolecular interactions. In addition, the MTT assay results indicated that the compounds 5 and 6 display effective activities against neurotoxicity which is induced by glutamine in PC12 cells. The in vivo experiment indicated that the compound 6 has a good protective effect on cerebral infarction.

  10. Labile Zn ions on octacalcium phosphate-derived Zn-containing hydroxyapatite surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Honda, Yoshitomo; Anada, Takahisa; Morimoto, Shinji [Division of Craniofacial Function Engineering (CFE), Tohoku University Graduate School of Dentistry, Sendai (Japan); Suzuki, Osamu, E-mail: suzuki-o@m.tohoku.ac.jp [Division of Craniofacial Function Engineering (CFE), Tohoku University Graduate School of Dentistry, Sendai (Japan)

    2013-05-15

    We previously synthesized and characterized zinc-containing octacalcium phosphate (OCP) and its hydrolyzed Ca-deficient hydroxyapatite (HA). In the present report, we attempted to define the state of Zn in the OCP-derived Zn-calcium phosphates (CaPs) in relation to the presence of specific amino acids. Zn-containing OCPs were prepared in solutions that included Zn ions up to a concentration of 3.5 mM, and their hydrolyzates [hydrolyzed (hy)-Zn-CaP] were obtained in hot water. The materials were characterized by x-ray diffraction and scanning electron microscopy. The concentration of Ca and Zn ions at room temperature was determined by analyzing the supernatant after incubating the materials in α-minimal essential medium (α-MEM) and HEPES buffer including cysteine, histidine, lysine, aspartic acid, and glutamic acid. Zn ions were more dissolved in α-MEM than HEPES buffer in the absence of amino acids. The inclusion of the amino acids enhanced Zn dissolution by several hundred fold, even in HEPES buffer. Among the amino acids, both cysteine and histidine enhanced the release of Zn. The effect was particularly remarkable with cysteine even in the presence of the other amino acids tested. These results indicate that Zn ions are present as a surface labile pool, which tends to be preferentially desorbed by cysteine, a ubiquitous molecule present in serum.

  11. Exploring Machine Learning to Correct Satellite-Derived Sea Surface Temperatures

    Directory of Open Access Journals (Sweden)

    Stéphane Saux Picart

    2018-02-01

    Full Text Available Machine learning techniques are attractive tools to establish statistical models with a high degree of non linearity. They require a large amount of data to be trained and are therefore particularly suited to analysing remote sensing data. This work is an attempt at using advanced statistical methods of machine learning to predict the bias between Sea Surface Temperature (SST derived from infrared remote sensing and ground “truth” from drifting buoy measurements. A large dataset of collocation between satellite SST and in situ SST is explored. Four regression models are used: Simple multi-linear regression, Least Square Shrinkage and Selection Operator (LASSO, Generalised Additive Model (GAM and random forest. In the case of geostationary satellites for which a large number of collocations is available, results show that the random forest model is the best model to predict the systematic errors and it is computationally fast, making it a good candidate for operational processing. It is able to explain nearly 31% of the total variance of the bias (in comparison to about 24% for the multi-linear regression model.

  12. REMOTE SENSING AND SURFACE ENERGY FLUX MODELS TO DERIVE EVAPOTRANSPIRATION AND CROP COEFFICIENT

    Directory of Open Access Journals (Sweden)

    Salvatore Barbagallo

    2008-06-01

    Full Text Available Remote sensing techniques using high resolution satellite images provide opportunities to evaluate daily crop water use and its spatial and temporal distribution on a field by field basis. Mapping this indicator with pixels of few meters of size on extend areas allows to characterize different processes and parameters. Satellite data on vegetation reflectance, integrated with in field measurements of canopy coverage features and the monitoring of energy fluxes through the soil-plant-atmosphere system, allow to estimate conventional irrigation components (ET, Kc thus improving irrigation strategies. In the study, satellite potential evapotranspiration (ETp and crop coefficient (Kc maps of orange orchards are derived using semi-empirical approaches between reflectance data from IKONOS imagery and ground measurements of vegetation features. The monitoring of energy fluxes through the orchard allows to estimate actual crop evapotranspiration (ETa using energy balance and the Surface Renewal theory. The approach indicates substantial promise as an efficient, accurate and relatively inexpensive procedure to predict actual ET fluxes and Kc from irrigated lands.

  13. Derived limits for occupational exposure to uranium mine and mill dusts in the air and on surfaces

    International Nuclear Information System (INIS)

    Carter, M.W.

    1983-01-01

    Limits are derived for the concentration of uranium mine and mill dusts in the air based on ICRP30 and assumptions regarding the isotopic make up of the dusts. From these limits using a resuspension factor, limits for surface contamination are derived. Calculations are presented of the dose to the basal layer of the skin from mine and mill dusts on the skin. From these calculations limits for skin contamination are derived. A calculation of a limit based on direct ingestion is also presented. Exposure limits for the public are not considered

  14. HIGHLY PRECISE APPROXIMATION OF FREE SURFACE GREEN FUNCTION AND ITS HIGH ORDER DERIVATIVES BASED ON REFINED SUBDOMAINS

    Directory of Open Access Journals (Sweden)

    Jiameng Wu

    2018-01-01

    Full Text Available The infinite depth free surface Green function (GF and its high order derivatives for diffraction and radiation of water waves are considered. Especially second order derivatives are essential requirements in high-order panel method. In this paper, concerning the classical representation, composed of a semi-infinite integral involving a Bessel function and a Cauchy singularity, not only the GF and its first order derivatives but also second order derivatives are derived from four kinds of analytical series expansion and refined division of whole calculation domain. The approximations of special functions, particularly the hypergeometric function and the algorithmic applicability with different subdomains are implemented. As a result, the computation accuracy can reach 10-9 in whole domain compared with conventional methods based on direct numerical integration. Furthermore, numerical efficiency is almost equivalent to that with the classical method.

  15. SAFARI 2000 AVHRR-derived Land Surface Temperature Maps, Africa, 1995-2000

    Data.gov (United States)

    National Aeronautics and Space Administration — Land Surface Temperature (LST) is a key indicator of land surface states, and can provide information on surface-atmosphere heat and mass fluxes, vegetation water...

  16. SAFARI 2000 AVHRR-derived Land Surface Temperature Maps, Africa, 1995-2000

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Land Surface Temperature (LST) is a key indicator of land surface states, and can provide information on surface-atmosphere heat and mass fluxes,...

  17. Advective surface velocity in the north west Pacific derived from NOAA AVHRR images

    Digital Repository Service at National Institute of Oceanography (India)

    Pankajakshan, T.; Akiyama, M.; Okada, Y.; Sugimori, Y.

    Using sequential AVHRR images in November 1983, nearsurface advective velocities are derived in the region Kuroshio south of Japan. For deriving the velocities two methods are used. One is the Method of Cross Correlation (MCC), using image pair...

  18. Comparison of Response Surface Construction Methods for Derivative Estimation Using Moving Least Squares, Kriging and Radial Basis Functions

    Science.gov (United States)

    Krishnamurthy, Thiagarajan

    2005-01-01

    Response construction methods using Moving Least Squares (MLS), Kriging and Radial Basis Functions (RBF) are compared with the Global Least Squares (GLS) method in three numerical examples for derivative generation capability. Also, a new Interpolating Moving Least Squares (IMLS) method adopted from the meshless method is presented. It is found that the response surface construction methods using the Kriging and RBF interpolation yields more accurate results compared with MLS and GLS methods. Several computational aspects of the response surface construction methods also discussed.

  19. Adaptive Layer Height During DLP Materials Processing

    DEFF Research Database (Denmark)

    Pedersen, David Bue; Zhang, Yang; Nielsen, Jakob Skov

    2016-01-01

    This research aim to show how manufacturing speeds during vat polymerisation can be vastly increased through an adaptive layer height strategy that takes the geometry into account through analysis of the relationship between layer height, cross-section variability and surface structure. This allows...... for considerable process speedup during the Additive Manufacture of components that contain areas of low cross-section variability, at no loss of surface quality. The adaptive slicing strategy was tested with a purpose built vat polymerisation system and numerical engine designed and constructed to serve as a Next...

  20. Spontaneous Pattern Formation Induced by Bénard-Marangoni Convection for Sol-Gel-Derived Titania Dip-Coating Films: Effect of Co-solvents with a High Surface Tension and Low Volatility.

    Science.gov (United States)

    Uchiyama, Hiroaki; Matsui, Tadayuki; Kozuka, Hiromitsu

    2015-11-17

    Evaporation-driven surface tension gradient in the liquid layer often causes the convective flow, i.e., Bénard-Marangoni convection, resulting in the formation of cell-like patterns on the surface. Here, we prepared sol-gel-derived titania films from Ti(OC3H7(i))4 solutions by dip coating and discussed the effect of the addition of co-solvents with a high surface tension and low volatility on the spontaneous pattern formation induced by Bénard-Marangoni convection. Propylene glycol (PG, with a surface tension of 38.6 mN m(-1)) and dipropylene glycol (DPG, with a surface tension of 33.9 mN m(-1)) were added to the coating solutions containing 2-propanol (2-Pr, with a surface tension of 22.9 mN m(-1)) for controlling the evaporation-driven surface tension gradient in the coating layer on a substrate. During dip coating at a substrate withdrawal speed of 50 cm min(-1) in a thermostatic oven at 60 °C, linearly arranged cell-like patterns on a micrometer scale were spontaneously formed on the titania gel films, irrespective of the composition of coating solutions. Such surface patterns remained even after the heat treatment at 200 and 600 °C, where the densification and crystallization of the titania films progressed. The width and height of the cell-like patterns increased with increasing PG and DPG contents in the coating solutions, where the addition of PG resulted in the formation of cells with a larger height than DPG.

  1. Spatial distribution, temporal variation and risks of parabens and their chlorinated derivatives in urban surface water in Beijing, China

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wenhui; Gao, Lihong [School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Shi, Yali; Wang, Yuan [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085 (China); Liu, Jiemin, E-mail: liujm@ustb.edu.cn [School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Cai, Yaqi, E-mail: caiyaqi@rcees.ac.cn [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085 (China)

    2016-01-01

    The occurrence and distribution of 13 target compounds, including eight parabens, four chlorinated parabens and p-hydroxybenzoic acid (PHBA), were detected in surface water samples at 35 sampling sites in the Beijing River system, China. The surface water samples were collected from the main rivers and lakes in the urban area monthly from July 2013 to June 2014 (except the frozen period). Laboratory analyses revealed that parabens were ubiquitous in the surface water of Beijing. PHBA was the predominant compound in the surface water samples, with the average concentration of 239 ng L{sup −1}, followed by the total amount of chlorinated parabens (average 50.1 ng/L) and parabens (average 44.3 ng/L). It is noteworthy that octylparaben with longer chain was firstly detected in the surface water. Significant difference was observed for paraben concentrations from different sampling sites, and the highest level of parabens was found in the Xiaotaihou River, which was mainly due to the untreated sewage discharge. Seasonal variation of target compounds in the urban surface water was also studied, and parabens exhibited a different temporal variation from chlorinated derivatives. A combination of factors including high residual chlorine level and water temperature as well as intense ultraviolet radiation might enhance the persistence of chlorinated parabens in chlorinated water during the wet season. Risk assessment showed that parabens and their chlorinated derivatives are not likely to produce biological effects on aquatic ecosystems at current levels in the surface water of Beijing. - Highlights: • Parabens and chlorinated parabens are ubiquitous in surface water in Beijing. • Octylparaben with longer chain was firstly detected in surface water. • Untreated sewage discharge was the main source of parabens in river. • Parabens exhibited a different seasonal variation from chlorinated derivatives. • The risks of target compounds are negligible at

  2. Incorporating shape constraints in generalized additive modelling of the height-diameter relationship for Norway spruce

    Directory of Open Access Journals (Sweden)

    Natalya Pya

    2016-02-01

    Full Text Available Background: Measurements of tree heights and diameters are essential in forest assessment and modelling. Tree heights are used for estimating timber volume, site index and other important variables related to forest growth and yield, succession and carbon budget models. However, the diameter at breast height (dbh can be more accurately obtained and at lower cost, than total tree height. Hence, generalized height-diameter (h-d models that predict tree height from dbh, age and other covariates are needed. For a more flexible but biologically plausible estimation of covariate effects we use shape constrained generalized additive models as an extension of existing h-d model approaches. We use causal site parameters such as index of aridity to enhance the generality and causality of the models and to enable predictions under projected changeable climatic conditions. Methods: We develop unconstrained generalized additive models (GAM and shape constrained generalized additive models (SCAM for investigating the possible effects of tree-specific parameters such as tree age, relative diameter at breast height, and site-specific parameters such as index of aridity and sum of daily mean temperature during vegetation period, on the h-d relationship of forests in Lower Saxony, Germany. Results: Some of the derived effects, e.g. effects of age, index of aridity and sum of daily mean temperature have significantly non-linear pattern. The need for using SCAM results from the fact that some of the model effects show partially implausible patterns especially at the boundaries of data ranges. The derived model predicts monotonically increasing levels of tree height with increasing age and temperature sum and decreasing aridity and social rank of a tree within a stand. The definition of constraints leads only to marginal or minor decline in the model statistics like AIC. An observed structured spatial trend in tree height is modelled via 2-dimensional surface

  3. Accuracy of linear measurements from cone-beam computed tomography-derived surface models of different voxel sizes

    NARCIS (Netherlands)

    Damstra, Janalt; Fourie, Zacharias; Huddleston Slater, James J R; Ren, Yijin

    INTRODUCTION: The aims of this study were to determine the linear accuracy of 3-dimensional surface models derived from a commercially available cone-beam computed tomography (CBCT) dental imaging system and volumetric rendering software and to investigate the influence of voxel resolution on the

  4. Segmentation process significantly influences the accuracy of 3D surface models derived from cone beam computed tomography

    NARCIS (Netherlands)

    Fourie, Zacharias; Damstra, Janalt; Schepers, Rutger H; Gerrits, Pieter; Ren, Yijin

    AIMS: To assess the accuracy of surface models derived from 3D cone beam computed tomography (CBCT) with two different segmentation protocols. MATERIALS AND METHODS: Seven fresh-frozen cadaver heads were used. There was no conflict of interests in this study. CBCT scans were made of the heads and 3D

  5. Relationship between the Physical Properties and Surface Area of Cellulose Derived from Adsorbates of Various Molecular Sizes.

    Science.gov (United States)

    Ougiya, H; Hioki, N; Watanabe, K; Morinaga, Y; Yoshinaga, F; Samejima, M

    1998-01-01

    An aqueous suspension of bacterial cellulose (BC) has such physical properties as higher viscosity, emulsion-stabilizing effect and filler retention than cellulose of other origins. The specific surface areas of BC, microfibrillated cellulose and wood pulp were evaluated by determining the maximum amounts of adsorption of Congo red, cellobiose dehydrogenase (CDH) and xyloglucan. There was a positive linear correlation between the above-mentioned physical properties of each cellulose sample and the specific surface area derived from the maximum amount of CDH adsorbed. The highest physical property values for BC result from the largest external surface area of the fibrils of BC to which CDH was adsorbed.

  6. Optimization of Truss Height

    Directory of Open Access Journals (Sweden)

    Tomas Ulitinas

    2011-04-01

    Full Text Available The article analyzes the task in truss height and in the optimization of the cross-sections of their elements. Element cross-sections are designed of steel profiles considering requirements for strength, stability and rigidity. A mathematical model is formulated as a nonlinear mathematical programming problem. It is solved as an iterative process, using mathematical software package “MATLAB” routine “fmincon”. The ratio of buckling is corrected in the each iteration. Optimization results are compared with those obtained applying software package “Robot Millennium”.Article in Lithuanian

  7. Characterization of protective immune responses induced by pneumococcal surface protein A in fusion with pneumolysin derivatives.

    Directory of Open Access Journals (Sweden)

    Cibelly Goulart

    Full Text Available Pneumococcal surface protein A (PspA and Pneumolysin derivatives (Pds are important vaccine candidates, which can confer protection in different models of pneumococcal infection. Furthermore, the combination of these two proteins was able to increase protection against pneumococcal sepsis in mice. The present study investigated the potential of hybrid proteins generated by genetic fusion of PspA fragments to Pds to increase cross-protection against fatal pneumococcal infection. Pneumolisoids were fused to the N-terminus of clade 1 or clade 2 pspA gene fragments. Mouse immunization with the fusion proteins induced high levels of antibodies against PspA and Pds, able to bind to intact pneumococci expressing a homologous PspA with the same intensity as antibodies to rPspA alone or the co-administered proteins. However, when antibody binding to pneumococci with heterologous PspAs was examined, antisera to the PspA-Pds fusion molecules showed stronger antibody binding and C3 deposition than antisera to co-administered proteins. In agreement with these results, antisera against the hybrid proteins were more effective in promoting the phagocytosis of bacteria bearing heterologous PspAs in vitro, leading to a significant reduction in the number of bacteria when compared to co-administered proteins. The respective antisera were also capable of neutralizing the lytic activity of Pneumolysin on sheep red blood cells. Finally, mice immunized with fusion proteins were protected against fatal challenge with pneumococcal strains expressing heterologous PspAs. Taken together, the results suggest that PspA-Pd fusion proteins comprise a promising vaccine strategy, able to increase the immune response mediated by cross-reactive antibodies and complement deposition to heterologous strains, and to confer protection against fatal challenge.

  8. Using Electronic Energy Derivative Information in Automated Potential Energy Surface Construction for Vibrational Calculations.

    Science.gov (United States)

    Sparta, Manuel; Hansen, Mikkel B; Matito, Eduard; Toffoli, Daniele; Christiansen, Ove

    2010-10-12

    The availability of an accurate representation of the potential energy surface (PES) is an essential prerequisite in an anharmonic vibrational calculation. At the same time, the high dimensionality of the fully coupled PES and the adverse scaling properties with respect to the molecular size make the construction of an accurate PES a computationally demanding task. In the past few years, our group tested and developed a series of tools and techniques aimed at defining computationally efficient, black-box protocols for the construction of PESs for use in vibrational calculations. This includes the definition of an adaptive density-guided approach (ADGA) for the construction of PESs from an automatically generated set of evaluation points. Another separate aspect has been the exploration of the use of derivative information through modified Shepard (MS) interpolation/extrapolation procedures. With this article, we present an assembled machinery where these methods are embedded in an efficient way to provide both a general machinery as well as concrete computational protocols. In this framework we introduce and discuss the accuracy and computational efficiency of two methods, called ADGA[2gx3M] and ADGA[2hx3M], where the ADGA recipe is used (with MS interpolation) to automatically define modest sized grids for up to two-mode couplings, while MS extrapolation based on, respectively, gradients only and gradients and Hessians from the ADGA determined points provides access to sufficiently accurate three-mode couplings. The performance of the resulting potentials is investigated in vibrational coupled cluster (VCC) calculations. Three molecular systems serve as benchmarks: a trisubstituted methane (CHFClBr), methanimine (CH2NH), and oxazole (C3H3NO). Furthermore, methanimine and oxazole are addressed in accurate calculations aiming to reproduce experimental results.

  9. Near-surface temperature inversion during summer at Summit, Greenland, and its relation to MODIS-derived surface temperatures

    Science.gov (United States)

    Adolph, Alden C.; Albert, Mary R.; Hall, Dorothy K.

    2018-03-01

    As rapid warming of the Arctic occurs, it is imperative that climate indicators such as temperature be monitored over large areas to understand and predict the effects of climate changes. Temperatures are traditionally tracked using in situ 2 m air temperatures and can also be assessed using remote sensing techniques. Remote sensing is especially valuable over the Greenland Ice Sheet, where few ground-based air temperature measurements exist. Because of the presence of surface-based temperature inversions in ice-covered areas, differences between 2 m air temperature and the temperature of the actual snow surface (referred to as skin temperature) can be significant and are particularly relevant when considering validation and application of remote sensing temperature data. We present results from a field campaign extending from 8 June to 18 July 2015, near Summit Station in Greenland, to study surface temperature using the following measurements: skin temperature measured by an infrared (IR) sensor, 2 m air temperature measured by a National Oceanic and Atmospheric Administration (NOAA) meteorological station, and a Moderate Resolution Imaging Spectroradiometer (MODIS) surface temperature product. Our data indicate that 2 m air temperature is often significantly higher than snow skin temperature measured in situ, and this finding may account for apparent biases in previous studies of MODIS products that used 2 m air temperature for validation. This inversion is present during our study period when incoming solar radiation and wind speed are both low. As compared to our in situ IR skin temperature measurements, after additional cloud masking, the MOD/MYD11 Collection 6 surface temperature standard product has an RMSE of 1.0 °C and a mean bias of -0.4 °C, spanning a range of temperatures from -35 to -5 °C (RMSE = 1.6 °C and mean bias = -0.7 °C prior to cloud masking). For our study area and time series, MODIS surface temperature products agree with skin surface

  10. 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.

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

    African Journals Online (AJOL)

    accurate predictor of height in forensic science, but cannot be directly measured in living patients.32 In a recent study in a public hospital in Brazil, it was indeed found that height prediction equations based on knee height outperformed those based on. Discrepancies of up to 19.8 cm were recorded, which is clinically.

  12. Satellite-derived surface and sub-surface water storage in the Ganges–Brahmaputra River Basin

    Directory of Open Access Journals (Sweden)

    Fabrice Papa

    2015-09-01

    New hydrological insights: Basin-scale monthly SWS variations for the period 2003–2007 show a mean annual amplitude of ∼410 km3, contributing to about 45% of the Gravity Recovery And Climate Experiment (GRACE-derived total water storage variations (TWS. During the drought-like conditions in 2006, we estimate that the SWS deficit over the entire GB basin in July–August–September was about 30% as compared to other years. The SWS variations are then used to decompose the GB GRACE-derived TWS and isolate the variations of SSWS whose mean annual amplitude is estimated to be ∼550 km3. This new dataset of water storage variations represent an unprecedented source of information for hydrological and climate modeling studies of the ISC.

  13. Mapping Forest Canopy Height over Continental China Using Multi-Source Remote Sensing Data

    Directory of Open Access Journals (Sweden)

    Xiliang Ni

    2015-06-01

    Full Text Available Spatially-detailed forest height data are useful to monitor local, regional and global carbon cycle. LiDAR remote sensing can measure three-dimensional forest features but generating spatially-contiguous forest height maps at a large scale (e.g., continental and global is problematic because existing LiDAR instruments are still data-limited and expensive. This paper proposes a new approach based on an artificial neural network (ANN for modeling of forest canopy heights over the China continent. Our model ingests spaceborne LiDAR metrics and multiple geospatial predictors including climatic variables (temperature and precipitation, forest type, tree cover percent and land surface reflectance. The spaceborne LiDAR instrument used in the study is the Geoscience Laser Altimeter System (GLAS, which can provide within-footprint forest canopy heights. The ANN was trained with pairs between spatially discrete LiDAR metrics and full gridded geo-predictors. This generates valid conjugations to predict heights over the China continent. The ANN modeled heights were evaluated with three different reference data. First, field measured tree heights from three experiment sites were used to validate the ANN model predictions. The observed tree heights at the site-scale agreed well with the modeled forest heights (R = 0.827, and RMSE = 4.15 m. Second, spatially discrete GLAS observations and a continuous map from the interpolation of GLAS-derived tree heights were separately used to evaluate the ANN model. We obtained R of 0.725 and RMSE of 7.86 m and R of 0.759 and RMSE of 8.85 m, respectively. Further, inter-comparisons were also performed with two existing forest height maps. Our model granted a moderate agreement with the existing satellite-based forest height maps (R = 0.738, and RMSE = 7.65 m (R2 = 0.52, and RMSE = 8.99 m. Our results showed that the ANN model developed in this paper is capable of estimating forest heights over the China continent with a

  14. 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

  15. Precise plant height monitoring and biomass estimation with Terrestrial Laser Scanning in paddy rice

    Directory of Open Access Journals (Sweden)

    N. Tilly

    2013-10-01

    Full Text Available Optimizing crop management is a major topic in the field of precision agriculture as the growing world population puts pressure on the efficiency of field production. Accordingly, methods to measure plant parameters with the needed precision and within-field resolution are required. Studies show that Terrestrial Laser Scanning (TLS is a suitable method to capture small objects like crop plants. In this contribution, the results of multi-temporal surveys on paddy rice fields with the TLS system Riegl LMS-Z420i are presented. Three campaigns were carried out during the key vegetative stage of rice plants in the growing period 2012 to monitor the plant height. The TLS-derived point clouds are interpolated to visualize plant height above ground as crop surface models (CSMs with a high resolution of 0.01 m. Spatio-temporal differences within the data of one campaign and between consecutive campaigns can be detected. The results were validated against manually measured plant heights with a high correlation (R2 = 0.71. Furthermore, the dependence of actual biomass from plant height was evaluated. To the present, no method for the non-destructive determination of biomass is found yet. Thus, plant parameters, like the height, have to be used for biomass estimations. The good correlation (R2 = 0.66 leads to the assumption that biomass can be estimated from plant height measurements. The results show that TLS can be considered as a very promising tool for precision agriculture.

  16. Evaluation of broadband surface solar irradiance derived from the Ozone Monitoring Instrument

    NARCIS (Netherlands)

    Wang, P.; Sneep, M.; Veefkind, J.P.; Stammes, P.; Levelt, P.F.

    2014-01-01

    Surface solar irradiance (SSI) data are important for planning and estimating the production of solar power plants. Long-term high quality surface solar radiation data are needed for monitoring climate change. This paper presents a new surface solar irradiance dataset, the broadband (0.2–4 ?m)

  17. Near-surface temperature inversion during summer at Summit, Greenland, and its relation to MODIS-derived surface temperatures

    Directory of Open Access Journals (Sweden)

    A. C. Adolph

    2018-03-01

    Full Text Available As rapid warming of the Arctic occurs, it is imperative that climate indicators such as temperature be monitored over large areas to understand and predict the effects of climate changes. Temperatures are traditionally tracked using in situ 2 m air temperatures and can also be assessed using remote sensing techniques. Remote sensing is especially valuable over the Greenland Ice Sheet, where few ground-based air temperature measurements exist. Because of the presence of surface-based temperature inversions in ice-covered areas, differences between 2 m air temperature and the temperature of the actual snow surface (referred to as skin temperature can be significant and are particularly relevant when considering validation and application of remote sensing temperature data. We present results from a field campaign extending from 8 June to 18 July 2015, near Summit Station in Greenland, to study surface temperature using the following measurements: skin temperature measured by an infrared (IR sensor, 2 m air temperature measured by a National Oceanic and Atmospheric Administration (NOAA meteorological station, and a Moderate Resolution Imaging Spectroradiometer (MODIS surface temperature product. Our data indicate that 2 m air temperature is often significantly higher than snow skin temperature measured in situ, and this finding may account for apparent biases in previous studies of MODIS products that used 2 m air temperature for validation. This inversion is present during our study period when incoming solar radiation and wind speed are both low. As compared to our in situ IR skin temperature measurements, after additional cloud masking, the MOD/MYD11 Collection 6 surface temperature standard product has an RMSE of 1.0 °C and a mean bias of −0.4 °C, spanning a range of temperatures from −35 to −5 °C (RMSE  =  1.6 °C and mean bias  =  −0.7 °C prior to cloud masking. For our study area and time series

  18. Comparison of surface energy fluxes with satellite-derived surface energy flux estimates from a shrub-steppe

    Energy Technology Data Exchange (ETDEWEB)

    Kirkham, Randy R. [Univ. of Washington, Seattle, WA (United States)

    1993-12-01

    This thesis relates the components of the surface energy balance (i.e., net radiation, sensible and latent heat flux densities, soil heat flow) to remotely sensed data for native vegetation in a semi-arid environment. Thematic mapper data from Landsat 4 and 5 were used to estimate net radiation, sensible heat flux (H), and vegetation amount. Several sources of ground truth were employed. They included soil water balance using the neutron thermalization method and weighing lysimeters, and the measurement of energy fluxes with the Bowen ratio energy balance (BREB) technique. Sensible and latent heat flux were measured at four sites on the U.S. Department of Energy`s Hanford Site using a weighing lysimeter and/or BREB stations. The objective was to calibrate an aerodynamic transport equation that related H to radiant surface temperature. The transport equation was then used with Landsat thermal data to generate estimates of H and compare these estimates against H values obtained with BREB/lysimeters at the time of overflight. Landsat and surface meteorologic data were used to estimate the radiation budget terms at the surface. Landsat estimates of short-wave radiation reflected from the surface correlate well with reflected radiation measured using inverted Eppley pyranometers. Correlation of net radiation estimates determined from satellite data, pyranometer, air temperature, and vapor pressure compared to net radiometer values obtained at time of overflight were excellent for a single image, but decrease for multiple images. Soil heat flux, GT, is a major component of the energy balance in arid systems and G{sub T} generally decreases as vegetation cover increases. Normalized difference vegetation index (NDVI) values generated from Landsat thermatic mapper data were representative of field observations of the presence of green vegetation, but it was not possible to determine a single relationship between NDVI and GT for all sites.

  19. Comparison of surface energy fluxes with satellite-derived surface energy flux estimates from a shrub-steppe

    International Nuclear Information System (INIS)

    Kirkham, R.R.

    1993-12-01

    This thesis relates the components of the surface energy balance (i.e., net radiation, sensible and latent heat flux densities, soil heat flow) to remotely sensed data for native vegetation in a semi-arid environment. Thematic mapper data from Landsat 4 and 5 were used to estimate net radiation, sensible heat flux (H), and vegetation amount. Several sources of ground truth were employed. They included soil water balance using the neutron thermalization method and weighing lysimeters, and the measurement of energy fluxes with the Bowen ratio energy balance (BREB) technique. Sensible and latent heat flux were measured at four sites on the U.S. Department of Energy's Hanford Site using a weighing lysimeter and/or BREB stations. The objective was to calibrate an aerodynamic transport equation that related H to radiant surface temperature. The transport equation was then used with Landsat thermal data to generate estimates of H and compare these estimates against H values obtained with BREB/lysimeters at the time of overflight. Landsat and surface meteorologic data were used to estimate the radiation budget terms at the surface. Landsat estimates of short-wave radiation reflected from the surface correlate well with reflected radiation measured using inverted Eppley pyranometers. Correlation of net radiation estimates determined from satellite data, pyranometer, air temperature, and vapor pressure compared to net radiometer values obtained at time of overflight were excellent for a single image, but decrease for multiple images. Soil heat flux, G T , is a major component of the energy balance in arid systems and G T generally decreases as vegetation cover increases. Normalized difference vegetation index (NDVI) values generated from Landsat thermatic mapper data were representative of field observations of the presence of green vegetation, but it was not possible to determine a single relationship between NDVI and G T for all sites

  20. Methods of Attaching or Grafting Carbon Nanotubes to Silicon Surfaces and Composite Structures Derived Therefrom

    Science.gov (United States)

    Tour, James M. (Inventor); Chen, Bo (Inventor); Flatt, Austen K. (Inventor); Stewart, Michael P. (Inventor); Dyke, Christopher A. (Inventor); Maya, Francisco (Inventor)

    2012-01-01

    The present invention is directed toward methods of attaching or grafting carbon nanotubes (CNTs) to silicon surfaces. In some embodiments, such attaching or grafting occurs via functional groups on either or both of the CNTs and silicon surface. In some embodiments, the methods of the present invention include: (1) reacting a silicon surface with a functionalizing agent (such as oligo(phenylene ethynylene)) to form a functionalized silicon surface; (2) dispersing a quantity of CNTs in a solvent to form dispersed CNTs; and (3) reacting the functionalized silicon surface with the dispersed CNTs. The present invention is also directed to the novel compositions produced by such methods.

  1. Synthesis, antibacterial and surface activity of 1,2,4-triazole derivatives

    Directory of Open Access Journals (Sweden)

    El-Sayed, R.

    2006-06-01

    Full Text Available The use of sodium 1-(4-amino-5-mercapto-4H-[1,2,4] triazol-3-yl and heptadecane-1-sulfonate (2 as new precursors to synthesize some important biologically active heterocycles has been found to be effective. The reaction of 2 with carbon disulphide in pyridine and acid chlorides yielded the 1,2,4-triazole derivatives 3, 4a and 4b.The condensation of 2 with appropriate aldehydes gave 5a-c which were cyclized by treating with thioglycollic acid to yield 6a-c. The reactions of 2 with phthalic anhydride and 4-methylbenzene-sulfonylchloride gave 7 and 8. In addition, the reaction of 2 with chloroacetaldehyde, phenacyl bromide, urea and chloroacetyl chloride yielded 9, 10, 11 and 12. At the same time, refluxing 2 with phenyl isothiocyanate gave 13 and 14. All these products have antimicrobial activity and they can be used as surface active agents.Es interesante el uso del 1-(4-amino-5-mercapto-4H- [1,2,4]triazol-3-ilheptadecano-1-sulfonato sódico (2 como un nuevo precursor en la síntesis de compuestos heterocíclicos biológicamente importantes. La reacción de 2 con disulfuro de carbono en piridina y cloruros de acilo rindió derivados 1,2,4-triazólicos. Condensación de 2 con aldehídos apropiados produjo 5a-c que ciclaron por tratamiento con ácido tioglicólico para dar lugar a 6a-c. Reacciones de 2 con anhídrido ftálico y cloruro de 4-metilbenzenosulfonilo produjeron 7 y 8. Además, la reacción de 2 con cloroacetaldehído, bromuro de fenacilo, urea, cloruro de tiacetilo produjo 9, 10, 11, y 12. Por otra parte, el reflujo de 2 con isocianato de fenilo dio 13 y 14. Todos los productos tuvieron actividad antimicrobiana y propiedades tensoactivas.

  2. Investigation of Polyaniline and a Functionalised Derivative as Antimicrobial Additives to Create Contamination Resistant Surfaces

    Directory of Open Access Journals (Sweden)

    Julia Robertson

    2018-03-01

    Full Text Available Antimicrobial surfaces can be applied to break transmission pathways in hospitals. Polyaniline (PANI and poly(3-aminobenzoic acid (P3ABA are novel antimicrobial agents with potential as non-leaching additives to provide contamination resistant surfaces. The activity of PANI and P3ABA were investigated in suspension and as part of absorbent and non-absorbent surfaces. The effect of inoculum size and the presence of organic matter on surface activity was determined. PANI and P3ABA both demonstrated bactericidal activity against Escherichia coli and Staphylococcus aureus in suspension and as part of an absorbent surface. Only P3ABA showed antimicrobial activity in non-absorbent films. The results that are presented in this work support the use of P3ABA to create contamination resistant surfaces.

  3. Ice particle habit and surface roughness derived from PARASOL polarization measurements

    OpenAIRE

    B. H. Cole; P. Yang; B. A. Baum; J. Riedi; L. C.-Labonnote

    2014-01-01

    Ice clouds are an important element in the radiative balance of the earth's climate system, but their microphysical and optical properties still are not well constrained, especially ice particle habit and the degree of particle surface roughness. In situ observations have revealed common ice particle habits and evidence for surface roughness, but these observations are limited. An alternative is to infer the ice particle shape and surface roughness from satellite observat...

  4. Height profile of particle concentration in an aeolian saltating cloud: A wind tunnel investigation by PIV MSD

    Science.gov (United States)

    Dong, Zhibao; Wang, Hongtao; Zhang, Xiaohang; Ayrault, Michael

    2003-10-01

    Attempt is made to define the particle concentration in an aeolian saltating cloud and its variation with height using artificial spherical quartz sand in a wind tunnel. The height profiles of the relative particle concentration in aeolian saltating cloud at three wind velocities were detected by the state of the art PIV (Particle Image Velocimetry) MSD (Mie Scattering Diffusion) technique, and converted to actual concentration based on sand transport rate and the variation with height of velocity of the saltating cloud. The particle concentration was found to decay exponentially with height and to increase with wind velocity. It decayed more rapidly when the wind velocity decreased. The volume/volume concentration in the near-surface layer was at the order of 10-4. The results obtained by PIV MSD technique were in good agreement with those derived from the sand flux and velocity profiles, the former being about 15% greater than the later.

  5. Improving Mean Minimum and Maximum Month-to-Month Air Temperature Surfaces Using Satellite-Derived Land Surface Temperature

    Directory of Open Access Journals (Sweden)

    Maria Mira

    2017-12-01

    Full Text Available Month-to-month air temperature (Tair surfaces are increasingly demanded to feed quantitative models related to a wide range of fields, such as hydrology, ecology or climate change studies. Geostatistical interpolation techniques provide such continuous and objective surfaces of climate variables, while the use of remote sensing data may improve the estimates, especially when temporal resolution is detailed enough. The main goal of this study is to propose an empirical methodology for improving the month-to-month Tair mapping (minimum and maximum using satellite land surface temperatures (LST besides of meteorological data and geographic information. The methodology consists on multiple regression analysis combined with the spatial interpolation of residual errors using the inverse distance weighting. A leave-one-out cross-validation procedure has been included in order to compare predicted with observed values. Different operational daytime and nighttime LST products corresponding to the four months more characteristic of the seasonal dynamics of a Mediterranean climate have been considered for a thirteen-year period. The results can be considered operational given the feasibility of the models employed (linear dependence on predictors that are nowadays easily available, the robustness of the leave-one-out cross-validation procedure and the improvement in accuracy achieved when compared to classical Tair modeling results. Unlike what is considered by most studies, it is shown that nighttime LST provides a good proxy not only for minimum Tair, but also for maximum Tair. The improvement achieved by the inclusion of remote sensing LST products was higher for minimum Tair (up to 0.35 K on December, especially over forests and rugged lands. Results are really encouraging, as there are generally few meteorological stations in zones with these characteristics, clearly showing the usefulness of remote sensing to improve information about areas that are

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

    Directory of Open Access Journals (Sweden)

    Hsi-Chyi Yeh

    2010-01-01

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

  7. Vertical datum unification for the International Height Reference System (IHRS)

    Science.gov (United States)

    Sánchez, Laura; Sideris, Michael G.

    2017-05-01

    The International Association of Geodesy released in July 2015 a resolution for the definition and realisation of an International Height Reference System (IHRS). According to this resolution, the IHRS coordinates are potential differences referring to the equipotential surface of the Earth's gravity field realised by the conventional value W0 = 62 636 853.4 m2s-2. A main component of the IHRS realisation is the integration of the existing height systems into the global one; that is existing vertical coordinates should be referred to one and the same reference level realised by the conventional W0. This procedure is known as vertical datum unification and its main result are the vertical datum parameters, that is the potential differences between the local and the global reference levels. In this paper, we rigorously derive the observation equations for the vertical datum unification in terms of potential quantities based on the geodetic boundary value problem (GBVP) approach. Those observation equations are then empirically evaluated for the vertical datum unification of the North American and South American height systems. In the first case, simulations performed in North America provide numerical estimates about the impact of omission errors and direct and indirect effects on the vertical datum parameters. In the second case, a combination of local geopotential numbers, ITRF coordinates, satellite altimetry observations, tide gauge registrations and high-resolution gravity field models is performed to estimate the level differences between the South American height systems and the global level W0. Results show that indirect effects vanish when a satellite-only gravity field model with a degree higher than n ≥ 180 is used for the solution of the GBVP. However, the component derived from satellite-only global gravity models has to be refined with terrestrial gravity data to minimise the omission error and its effect on the vertical datum parameter estimation

  8. PULSE HEIGHT ANALYZER

    Science.gov (United States)

    Johnstone, C.W.

    1958-01-21

    An anticoincidence device is described for a pair of adjacent channels of a multi-channel pulse height analyzer for preventing the lower channel from generating a count pulse in response to an input pulse when the input pulse has sufficient magnitude to reach the upper level channel. The anticoincidence circuit comprises a window amplifier, upper and lower level discriminators, and a biased-off amplifier. The output of the window amplifier is coupled to the inputs of the discriminators, the output of the upper level discriminator is connected to the resistance end of a series R-C network, the output of the lower level discriminator is coupled to the capacitance end of the R-C network, and the grid of the biased-off amplifier is coupled to the junction of the R-C network. In operation each discriminator produces a negative pulse output when the input pulse traverses its voltage setting. As a result of the connections to the R-C network, a trigger pulse will be sent to the biased-off amplifier when the incoming pulse level is sufficient to trigger only the lower level discriminator.

  9. Multifractal and Singularity Maps of soil surface moisture distribution derived from 2D image analysis.

    Science.gov (United States)

    Cumbrera, Ramiro; Millán, Humberto; Martín-Sotoca, Juan Jose; Pérez Soto, Luis; Sanchez, Maria Elena; Tarquis, Ana Maria

    2016-04-01

    methods for mapping geochemical anomalies caused by buried sources and for predicting undiscovered mineral deposits in covered areas. Journal of Geochemical Exploration, 122, 55-70. Cumbrera, R., Ana M. Tarquis, Gabriel Gascó, Humberto Millán (2012) Fractal scaling of apparent soil moisture estimated from vertical planes of Vertisol pit images. Journal of Hydrology (452-453), 205-212. Martin Sotoca; J.J. Antonio Saa-Requejo, Juan Grau and Ana M. Tarquis (2016). Segmentation of singularity maps in the context of soil porosity. Geophysical Research Abstracts, 18, EGU2016-11402. Millán, H., Cumbrera, R. and Ana M. Tarquis (2016) Multifractal and Levy-stable statistics of soil surface moisture distribution derived from 2D image analysis. Applied Mathematical Modelling, 40(3), 2384-2395.

  10. Reconciling Electrical Properties of Titan's Surface Derived from Cassini RADAR Scatterometer and Radiometer Measurements

    Science.gov (United States)

    Zebker, H. A.; Wye, L. C.; Janssen, M.; Paganelli, F.; Cassini RADAR Team

    2006-12-01

    We observe Titan, Saturn's largest moon, using active and passive microwave instruments carried on board the Cassini spacecraft. The 2.2-cm wavelength penetrates the thick atmosphere and provides surface measurements at resolutions from 10-200 km over much of the satellite's surface. The emissivity and reflectivity of surface features are generally anticorrelated, and both values are fairly high. Inversion of either set of data alone yields dielectric constants ranging from 1.5 to 3 or 4, consistent with an icy hydrocarbon or water ice composition. However, the dielectric constants retrieved from radiometric data alone are usually less than those inferred from backscatter measurements, a discrepancy consistent with similar analyses dating back to lunar observations in the 1960's. Here we seek to reconcile Titan's reflectivity and emissivity observations using a single physical model of the surface. Our approach is to calculate the energy scattered by Titan's surface and near subsurface, with the remainder absorbed. In equilibrium the absorption equals the emission, so that both the reflectivity and emissivity are described by the model. We use a form of the Kirchhoff model for modeling surface scatter, and a model based on weak localization of light for the volume scatter. With this model we present dielectric constant and surface roughness parameters that match both sets of Cassini RADAR observations over limited regions on Titan's surface, helping to constrain the composition and roughness of the surface. Most regions display electrical properties consistent with solid surfaces, however some of the darker "lake-like" features at higher latitudes can be modeled as either solid or liquid materials. The ambiguity arises from the limited set of observational angles available.

  11. 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...

  12. 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...

  13. MLS/Aura Level 2 Geopotential Height V004

    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. Effectiveness of a coral-derived surfacing material for reducing sediment production on unpaved roads, Schoffield barracks, Oahu, Hawaii.

    Science.gov (United States)

    Ziegler, Alan D; Sutherland, Ross A

    2006-01-01

    This study evaluated the effectiveness of two application rates of a coral-derived surfacing material for both traffic and nontraffic road conditions using simulated rainfall (110-120 mm h(-1) for 30-90 min) on 0.75-m (wide) x 5.0-m (long) plots of similar slope (roughly 0.1 m m(-1)). The coral is a locally available material that has been applied to unpaved roads surfaces on Schoffield Barracks, Oahu, Hawaii (USA), where this experiment was conducted. The simulations show that compared with a bare control plot, the coral-based surface application rates of 80 and 160 kg m(-2) (equivalent to only 10- and 20-mm thicknesses) reduced road sediment production by 75% and 95%, respectively, for nontraffic conditions. However, after two passes of the research vehicle during wet conditions, sediment production rates for the two coral treatments were not significantly different from those on the bare road plots. The overall effectiveness of the coral-derived surfacing material is unsatisfactory, primarily because the on-road surface thickness associated with the application rates tested was too small. These rates were selected to bracket those applied to training roads in the study area. Furthermore, the composition of the coral-based material does not facilitate the development of a sealed, erosion-resistant surface. When applied at the low rates tested, the coral material breaks down under normal traffic conditions, thereby losing its ability to counter shearing forces exerted by overland flow on long hillslopes where erosion measures are most needed. These simulations, combined with observations on roads in the study area, indicate that this material is not an appropriate road surfacing material for the site-at least for the low application rates examined. These results are preliminary; extended testing of higher applications rates at the hillslope scale under natural climate and traffic conditions is needed to better judge the effectiveness of this material over time.

  15. Surface circulation in the Iroise Sea (western Brittany) derived from high resolution current mapping by HF radars

    Science.gov (United States)

    Sentchev, Alexei; Forget, Philippe; Barbin, Yves; Marié, Louis; Ardhuin, Fabrice

    2010-05-01

    The use of high frequency radar (HFR) systems for near-real-time coastal ocean monitoring necessities that short time scale motions of the radar-derived velocities are better understood. While the ocean radar systems are able to describe coastal flow patterns with unprecedented details, the data they produce are often too sparse or gappy for applications such as the identification of coherent structures and fronts or understanding transport and mixing processes. In this study, we address two challenges. First, we report results from the HF radar system (WERA) which is routinely operating since 2006 on the western Brittany coast to monitor surface circulation in the Iroise Sea, over an area extending up to 100 km offshore. To obtain more reliable records of vector current fields at high space and time resolution, the Multiple Signal Classification (MUSIC) direction finding algorithm is employed in conjunction with the variational interpolation (2dVar) of radar-derived velocities. This provides surface current maps at 1 km spacing and time resolution of 20 min. Removing the influence of the sea state on radar-derived current measurements is discussed and performed on some data sequences. Second, we examine in deep continuous 2d velocity records for a number of periods, exploring the different modes of variability of surface currents in the region. Given the extent, duration, and resolution of surface current velocity measurements, new quantitative insights from various time series and spatial analysis on higher frequency kinematics will be discussed. By better characterizing the full spectrum of flow regimes that contribute to the surface currents and their shears, a more complete picture of the circulation in the Iroise Sea can be obtained.

  16. Distribution of icy particles across Enceladus' surface as derived from Cassini-VIMS measurements

    Science.gov (United States)

    Jaumann, R.; Stephan, K.; Hansen, G. B.; Clark, R. N.; Buratti, B. J.; Brown, R. H.; Baines, K. H.; Newman, S. F.; Bellucci, G.; Filacchione, G.; Coradini, A.; Cruikshank, D. P.; Griffith, C. A.; Hibbitts, C. A.; McCord, T. B.; Nelson, R. M.; Nicholson, P. D.; Sotin, C.; Wagner, R.

    2008-02-01

    The surface of Enceladus consists almost completely of water ice. As the band depths of water ice absorptions are sensitive to the size of particles, absorptions can be used to map variations of icy particles across the surface. The Visual and Infrared Mapping Spectrometer (VIMS) observed Enceladus with a high spatial resolution during three Cassini flybys in 2005 (orbits EN 003, EN 004 and EN 011). Based on these data we measured the band depths of water ice absorptions at 1.04, 1.25, 1.5, and 2 μm. These band depths were compared to water ice models that represent theoretically calculated reflectance spectra for a range of particle diameters between 2 μm and 1 mm. The agreement between the experimental (VIMS) and model values supports the assumption that pure water ice characterizes the surface of Enceladus and therefore that variations in band depth correspond to variations in water ice particle diameters. Our measurements show that the particle diameter of water ice increases toward younger tectonically altered surface units with the largest particles exposed in relatively "fresh" surface material. The smallest particles were generally found in old densely cratered terrains. The largest particles (˜0.2 mm) are concentrated in the so called "tiger stripes" at the south pole. In general, the particle diameters are strongly correlated with geologic features and surface ages, indicating a stratigraphic evolution of the surface that is caused by cryovolcanic resurfacing and impact gardening.

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. Curvature Derivative Surface used to characterize the complexity of the seafloor around St. John, USVI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Curvature was calculated from the bathymetry surface for each raster cell using the ArcGIS 3D Analyst "Curvature" Tool. Curvature describes the rate of change of...

  3. Rugosity Derivative Surface used to characterize the complexity of the seafloor around St. John, USVI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Rugosity was calculated from the bathymetry surface for each cell using the "Rugosity" function in the Benthic Terrain Modeler toolbox (Jenness 2002, 2004; Wright et...

  4. Near-surface circulation and kinetic energy in the tropical Indian Ocean derived from lagrangian drifters

    Digital Repository Service at National Institute of Oceanography (India)

    Shenoi, S.S.C.; Saji, P.K.; Almeida, A.M.

    Trajectories of 412 satellite-tracked drifting buoys deployed in the tropical Indian Ocean have been analyzed to document the surface circulation and kinetic energy field. Only drifters drogued at 15 m depth and having drag area ratio greater than...

  5. Modeling directional effects in land surface temperature derived from geostationary satellite data

    DEFF Research Database (Denmark)

    Rasmussen, Mads Olander

    This PhD-thesis investigates the directional effects in land surface temperature (LST) estimates from the SEVIRI sensor onboard the Meteosat Second Generation (MSG) satellites. The directional effects are caused by the land surface structure (i.e. tree size and shape) interacting with the changing...... the illumination geometry changes both over the course of the day and with the seasons. In the present study, the directional effects are assessed at different scales using a modeling approach. The model applied, the Modified Geometry Projection (MGP) model, represents the surface as a composite of four components...... that the magnitude of the directional effects mainly depends on the tree cover, with moderate tree covers (20-40 %) causing the largest directional effects but with significant effects also at much sparser tree cover. The magnitude is also highly dependent on the temperature difference between the surface components...

  6. Profile Curvature Derivative Surface used to characterize the complexity of the seafloor around St. John, USVI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Profile curvature was calculated from the bathymetry surface for each raster cell using the ArcGIS 3D Analyst "Curvature" Tool. Profile curvature describes the rate...

  7. Slope Derivative Surface used to characterize the complexity of the seafloor around St. John, USVI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Slope was calculated from the bathymetry surface for each raster cell using ArcGIS's Spatial Analyst 'Slope' Tool. Slope describes the maximum steepness of a terrain...

  8. Using surface remote sensors to derive radiative characteristics of Mixed-Phase Clouds: an example from M-PACE

    Directory of Open Access Journals (Sweden)

    G. de Boer

    2011-12-01

    Full Text Available Measurements from ground-based cloud radar, high spectral resolution lidar and microwave radiometer are used in conjunction with a column version of the Rapid Radiative Transfer Model (RRTMG and radiosonde measurements to derive the surface radiative properties under mixed-phase cloud conditions. These clouds were observed during the United States Department of Energy (US DOE Atmospheric Radiation Measurement (ARM Mixed-Phase Arctic Clouds Experiment (M-PACE between September and November of 2004. In total, sixteen half hour time periods are reviewed due to their coincidence with radiosonde launches. Cloud liquid (ice water paths are found to range between 11.0–366.4 (0.5–114.1 gm−2, and cloud physical thicknesses fall between 286–2075 m. Combined with temperature and hydrometeor size estimates, this information is used to calculate surface radiative flux densities using RRTMG, which are demonstrated to generally agree with measured flux densities from surface-based radiometric instrumentation. Errors in longwave flux density estimates are found to be largest for thin clouds, while shortwave flux density errors are generally largest for thicker clouds. A sensitivity study is performed to understand the impact of retrieval assumptions and uncertainties on derived surface radiation estimates. Cloud radiative forcing is calculated for all profiles, illustrating longwave dominance during this time of year, with net cloud forcing generally between 50 and 90 Wm−2.

  9. Photogeneration of singlet oxygen by the phenothiazine derivatives covalently bound to the surface-modified glassy carbon

    Energy Technology Data Exchange (ETDEWEB)

    Blacha-Grzechnik, Agata, E-mail: agata.blacha@polsl.pl [Faculty of Chemistry, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland); Piwowar, Katarzyna; Krukiewicz, Katarzyna [Faculty of Chemistry, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland); Koscielniak, Piotr; Szuber, Jacek [Institute of Electronics, Silesian University of Technology, Akademicka 16, 44-100 Gliwice (Poland); Zak, Jerzy K. [Faculty of Chemistry, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland)

    2016-05-15

    Highlights: • The selected group of four NH{sub 2}-derivatives of phenothiazine was grafted to Glassy Carbon (GC) surface. • The grafted phenothiazines are able to generate {sup 1}O{sub 2} when activated by the radiation. • Such modified solid surfaces may find their application in the wastewater treatment. - Abstract: The selected group of four amine-derivatives of phenothiazine was covalently grafted to the glassy carbon surface in the four-step procedure consisting of the electrochemical reduction of the diazonium salt followed by the electrochemical and chemical post-modification steps. The proposed strategy involves the bonding of linker molecule to which the photosensitizer is attached. The synthesized organic layers were characterized by means of cyclic voltammetry, XPS and Raman Spectroscopy. It was shown that the phenothiazines immobilized via proposed strategy retain their photochemical properties and are able to generate {sup 1}O{sub 2} when activated by the laser radiation. The effectiveness of in situ singlet oxygen generation by those new solid photoactive materials was determined by means of UVVis spectroscopy. The reported, covalently modified solid surfaces may find their application as the singlet oxygen photogenerators in the fine chemicals’ synthesis or in the wastewater treatment.

  10. Near-surface bulk densities of asteroids derived from dual-polarization radar observations

    Science.gov (United States)

    Virkki, A.; Taylor, P. A.; Zambrano-Marin, L. F.; Howell, E. S.; Nolan, M. C.; Lejoly, C.; Rivera-Valentin, E. G.; Aponte, B. A.

    2017-09-01

    We present a new method to constrain the near-surface bulk density and surface roughness of regolith on asteroid surfaces using planetary radar measurements. The number of radar observations has increased rapidly during the last five years, allowing us to compare and contrast the radar scattering properties of different small-body populations and compositional types. This provides us with new opportunities to investigate their near-surface physical properties such as the chemical composition, bulk density, porosity, or the structural roughness in the scale of centimeters to meters. Because the radar signal can penetrate into a planetary surface up to a few decimeters, radar can reveal information that is hidden from other ground-based methods, such as optical and infrared measurements. The near-surface structure of asteroids and comets in centimeter-to-meter scale is essential information for robotic and human space missions, impact threat mitigation, and understanding the history of these bodies as well as the formation of the whole Solar System.

  11. Tuning the surface chemistry of lubricant-derived phosphate thermal films: The effect of boron

    Energy Technology Data Exchange (ETDEWEB)

    Spadaro, F. [Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, CH-8093 Zurich (Switzerland); Rossi, A., E-mail: antonella.rossi@mat.ethz.ch [Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, CH-8093 Zurich (Switzerland); Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, Cittadella Universitaria di Monserrato, I-09100, Cagliari (Italy); Lainé, E.; Woodward, P. [Enabling Research, Infineum UK Ltd., Milton Hill, Steventon, Oxfordshire OX13 6BD (United Kingdom); Spencer, N.D., E-mail: nicholas.spencer@mat.ethz.ch [Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, CH-8093 Zurich (Switzerland)

    2017-02-28

    Highlights: • The additives bulk interactions in “neat” blends at high temperatures is evaluated. • The competition among the different additives to react with air-oxidized steel surfaces under pure thermal condition is investigated. • Different thermal films are grown, their in depth-composition and thickness is determined by ARXPS. • A reaction mechanism is proposed for elucidating the composition of the thermals films. - Abstract: Understanding the interactions among the various additives in a lubricant is important because they can have a major influence on the performance of blends under tribological conditions. The present investigation is focused on the interactions occurring between ZnDTP and dispersant molecules in an oil formulation, and on their reactivity under purely thermal conditions in the presence of air-oxidized iron surfaces. Nuclear magnetic resonance spectroscopy (NMR) was performed on undiluted blends at different temperatures, while angle-resolved X-ray photoelectron spectroscopy (ARXPS) was exploited to investigate the surface reactivity on oxidized iron surfaces. The results indicate that the dispersant, generally added to blends for preventing the deposition of sludge, varnish and soot on the surface, might also inhibit the reaction of all other additives with the steel surface.

  12. Baculovirus Per Os Infectivity Factors Form a Complex on the Surface of Occlusion-Derived Virus

    NARCIS (Netherlands)

    Peng, K.; Oers, van M.M.; Hu, Z.; Lent, van J.W.M.; Vlak, J.M.

    2010-01-01

    Five highly conserved per os infectivity factors, PIF1, PIF2, PIF3, PIF4, and P74, have been reported to be essential for oral infectivity of baculovirus occlusion-derived virus (ODV) in insect larvae. Three of these proteins, P74, PIF1, and PIF2, were thought to function in virus binding to insect

  13. Effect on Concrete Surface Water Absorption upon Addition of Lactate Derived Agent

    NARCIS (Netherlands)

    Mors, R.M.; Jonkers, H.M.

    2017-01-01

    Water tightness of a concrete cover layer is important, as it is typically used as a protective coating of the steel reinforcement. Water tightness can be impaired by crack formation or by permeability. A bacteria-based lactate-derived healing agent (HA) can be added to concrete to enhance the

  14. Synthesis and Characterization of Surface Modified, Fluorescent and Biocompatible ZnS Nanoparticles with a Hydrophobic Chitosan Derivative.

    Science.gov (United States)

    Jothimani, B; Sureshkumar, S; Venkatachalapathy, B

    2017-07-01

    The introduction of a hydrophobic moiety on chitosan enhances the self-assembling properties, mucoadhesion, the permeability of the macromolecule and aids in target specific delivery. Our group synthesized a hydrophobic trans N-(6,6-Dimethyl-2-hepten-4-ynyl)chitosan derivative (CSD) and studied the surface modification of ZnS nanoparticles in a single pot reaction. X-ray diffraction studies and FESEM imaging confirms the nano size and morphology of the surface modified Zinc sulfide nanoparticles (ZnS-CSD NPs). The proposed ZnS-CSD NPs showed excellent emission at 457 nm. Photostability studies indicate that the surface modified ZnS-CSD NPs possess better photostability than Rhodamine B and FITC. Cell viability tests confirmed the biocompatibility of the modified nanoparticles. All these features of ZnS- CSD NPs makes these candidates an excellent choice in a wide range of in vitro or in vivo studies as fluorescent biological labels.

  15. Heritability of adult body height

    DEFF Research Database (Denmark)

    Silventoinen, Karri; Sammalisto, Sampo; Perola, Markus

    2003-01-01

    A major component of variation in body height is due to genetic differences, but environmental factors have a substantial contributory effect. In this study we aimed to analyse whether the genetic architecture of body height varies between affluent western societies. We analysed twin data from...... eight countries comprising 30,111 complete twin pairs by using the univariate genetic model of the Mx statistical package. Body height and zygosity were self-reported in seven populations and measured directly in one population. We found that there was substantial variation in mean body height between...... 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...

  16. MODIS-Derived Spatiotemporal Changes of Major Lake Surface Areas in Arid Xinjiang, China, 2000–2014

    Directory of Open Access Journals (Sweden)

    Qingting Li

    2015-10-01

    Full Text Available Inland water bodies, which are critical freshwater resources for arid and semi-arid areas, are very sensitive to climate change and human disturbance. In this paper, we derived a time series of major lake surface areas across Xinjiang Uygur Autonomous Region (XUAR, China, based on an eight-day MODIS time series in 500 m resolution from 2000 to 2014. A classification approach based on water index and dynamic threshold selection was first developed to accommodate varied spectral features of water pixels at different temporal steps. The overall classification accuracy for a MODIS-derived water body is 97% compared to a water body derived using Landsat imagery. Then, monthly composites of water bodies were derived for the months of April, July, and September to identify seasonal patterns and inter-annual dynamics of 10 major lakes (>100 km2 in XUAR. Our results indicate that the changing trends of surface area of major lakes varied across the region. The surface areas of the Ebinur and Bosten Lakes showed a significant shrinking trend. The Ulungur-Jili Lake remained relatively stable during the entire period. For mountain lakes, the Barkol Lake showed a decreasing trend in April and July, but the Sayram Lake showed a significant expanding trend in September. The four plateau lakes exhibited significant expanding trends in all three seasons except for Arkatag Lake in July. The shrinking of major lakes reflects severe anthropogenic impacts due to agricultural and industrial needs, in addition to the impact of climate change. The pattern of lake changes across the XUAR can provide insight into the impact of climate change and human activities on regional water resources in this arid and semi-arid region.

  17. 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...

  18. Operational surface currents derived from satellite altimeters and scatterometers; Pilot Study for the Tropical Pacific

    Science.gov (United States)

    Lagerloef, G.

    1 and diagnose model errors. Another immediate application of these data relates to fisheries management and ma- rine wildlife research in the region. Movements of several species of sea turtle in the tropical region are being tracked by satellite with System Argos. Results show that some turtle tracks follow meandering portions of the North Equatorial Current and North Equatorial Counter Current. The surface current data allow researchers to exam- ine the oceanography of the habitat these turtles are using, for example, and evaluate to what extent they are using the equatorial currents and regions of surface convergence. Findings indicate that different species/stocks use different habitats. Some forage at or near the surface at convergences and others forage sub-surface away from currents (Polovina et al., 2002). References: Bonjean, F. and G.S.E. Lagerloef, 2002: Diagnostic model and analysis of the surface currents in the Tropical Pacific Ocean, J. Phys. Oceanogr., In press. Lagerloef,G.S.E., G.Mitchum, R.Lukas and P.Niiler, 1999: Tropical Pacific near sur- face currents estimated from altimeter, wind and drifter data, J. Geophys. Res., 104, 23,313-23,326. Polovina, J. J., G. H. Balazs, E. A Howell, D. M. Parker, M. P. Seki, and P. H. Dutton, 2002. Forage and migration habitat of loggerhead (Caretta caretta) and olive ridley (Lepidochelys olivacea) sea turtles in the central North Pacific Ocean. Fish. Oceanogr., In Review.

  19. Surface hopping dynamics of direct trans --> cis photoswitching of an azobenzene derivative in constrained adsorbate geometries

    Science.gov (United States)

    Floß, Gereon; Granucci, Giovanni; Saalfrank, Peter

    2012-12-01

    With ongoing miniaturization of electronic devices, the need for individually addressable, switchable molecules arises. An example are azobenzenes on surfaces which have been shown to be switchable between trans and cis forms. Here, we examine the "direct" (rather than substrate-mediated) channel of the trans → cis photoisomerization after ππ* excitation of tetra-tert-butyl-azobenzene physisorbed on surfaces mimicking Au(111) and Bi(111), respectively. In spirit of the direct channel, the electronic structure of the surface is neglected, the latter merely acting as a rigid platform which weakly interacts with the molecule via Van-der-Waals forces. Starting from thermal ensembles which represent the trans-form, sudden excitations promote the molecules to ππ*-excited states which are non-adiabatically coupled among themselves and to a nπ*-excited and the ground state, respectively. After excitation, relaxation to the ground state by internal conversion takes place, possibly accompanied by isomerization. The process is described here by "on the fly" semiclassical surface hopping dynamics in conjunction with a semiempirical Hamiltonian (AM1) and configuration-interaction type methods. It is found that steric constraints imposed by the substrate lead to reduced but non-vanishing, trans → cis reaction yields and longer internal conversion times than for the isolated molecule. Implications for recent experiments for azobenzenes on surfaces are discussed.

  20. 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...

  1. Spatially Complete Surface Albedo Data Sets: Value-Added Products Derived from Terra MODIS Land Products

    Science.gov (United States)

    Moody, Eric G.; King, Michael D.; Platnick, Steven; Schaaf, Crystal B.; Gao, Feng

    2004-01-01

    Spectral land surface albedo is an important parameter for describing the radiative properties of the Earth. Accordingly it reflects the consequences of natural and human interactions, such as anthropogenic, meteorological, and phenological effects, on global and local climatological trends. Consequently, albedos are integral parts in a variety of research areas, such as general circulation models (GCMs), energy balance studies, modeling of land use and land use change, and biophysical, oceanographic, and meteorological studies. Recent observations of diffuse bihemispherical (white-sky) and direct beam directional hemispherical (black-sky ) land surface albedo included in the MOD43B3 product from MODIS instruments aboard NASA's Terra and Aqua satellite platforms have provided researchers with unprecedented spatial, spectral, and temporal characteristics. Cloud and seasonal snow cover, however, curtail retrievals to approximately half the global land surfaces on an annual equal-angle basis, precluding MOD43B3 albedo products from direct inclusion in some research projects and production environments.

  2. Variants of a Leishmania surface antigen derived from a multigenic family.

    Science.gov (United States)

    Murray, P J; Spithill, T W

    1991-12-25

    The promastigote surface antigen-2 (PSA-2) complex comprises a group of immunogenic surface antigens linked to the surface of the Leishmania major promastigote with glycosylphosphatidylinositol anchors. The L. major genome contains at least 14 PSA-2 genes on a 950-kilobase chromosome and comprising approximately 20% of the length of this chromosome. The sequence of three independent, but incomplete, PSA-2 cDNAs and one genomic fragment encoding a complete PSA-2 coding sequence were compared. PSA-2 genes encode polypeptides exhibiting 22-25aa tandem repeat elements, threonine-rich segments which vary between genes, a conserved COOH-terminal cysteine-rich region, and a conserved GPI anchor signal sequence. PSA-2 genes appear to be transcribed in a complex manner with multiple RNAs. The complex genomic organization of PSA-2 genes is present in other members of the genus suggesting that PSA-2 function is important for the biology of Leishmania.

  3. 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 ...

  4. Wind‐gust parametrizations at heights relevant for wind energy: a study based on mast observations

    DEFF Research Database (Denmark)

    Suomi, I.; Vihma, T.; Gryning, Sven-Erik

    2013-01-01

    Wind gusts are traditionally observed and reported at the reference height of 10 m and most gust parametrization methods have been developed only for this height. In many practical applications, e.g. in wind energy, the relevant heights are, however, up to a few hundred metres. In this study, mean...... speed, which is parametrized on the basis of the surface friction velocity, the Obukhov length and height and the boundary‐layer height. The new gust parametrization method outperformed the two older methods: the effects of surface roughness, stability and the height above the surface were well...

  5. Regional Distribution of Forest Height and Biomass from Multisensor Data Fusion

    Science.gov (United States)

    Yu, Yifan; Saatchi, Sassan; Heath, Linda S.; LaPoint, Elizabeth; Myneni, Ranga; Knyazikhin, Yuri

    2010-01-01

    Elevation data acquired from radar interferometry at C-band from SRTM are used in data fusion techniques to estimate regional scale forest height and aboveground live biomass (AGLB) over the state of Maine. Two fusion techniques have been developed to perform post-processing and parameter estimations from four data sets: 1 arc sec National Elevation Data (NED), SRTM derived elevation (30 m), Landsat Enhanced Thematic Mapper (ETM) bands (30 m), derived vegetation index (VI) and NLCD2001 land cover map. The first fusion algorithm corrects for missing or erroneous NED data using an iterative interpolation approach and produces distribution of scattering phase centers from SRTM-NED in three dominant forest types of evergreen conifers, deciduous, and mixed stands. The second fusion technique integrates the USDA Forest Service, Forest Inventory and Analysis (FIA) ground-based plot data to develop an algorithm to transform the scattering phase centers into mean forest height and aboveground biomass. Height estimates over evergreen (R2 = 0.86, P data and loss of scattering phase center from tree ]surface interaction. We used two methods to estimate AGLB; algorithms based on direct estimation from the scattering phase center produced higher precision (R2 = 0.79, RMSE = 25 Mg/ha) than those estimated from forest height (R2 = 0.25, RMSE = 66 Mg/ha). We discuss sources of uncertainty and implications of the results in the context of mapping regional and continental scale forest biomass distribution.

  6. Surface characterization of sol–gel derived indium tin oxide films on ...

    Indian Academy of Sciences (India)

    Unknown

    mental moisture trapped in the film surface. In addition, contamination of carbon from environment cannot be ruled out. As hydrogen atoms have higher ... be due to the condensation of two –OH groups of two In–. OH entities producing relatively high crystalline envi- ronment in ITO. Figure 2. Results of peak analysis of O1s ...

  7. Incompletely-Condensed Fluoroalkyl Silsesquioxanes and Derivatives: Precursors for Low Surface Energy Materials (Preprint)

    Science.gov (United States)

    2011-09-13

    controlled functionalization of Fluorinated Polyhedral Oligomeric SilSesquioxanes (F-POSS), which are useful as low surface energy materials for...fluorinated nanobuilding blocks with a controlled level of reactive functionality for the development of new superhydrophobic and oleophobic... structures were subsequently modified with non-fluorinated symmetric and asymmetric dichlorosilanes to produce functionalized F-POSS for applications in

  8. Comparison between MODIS-derived day and night cloud cover and surface observations over the North China Plain

    Science.gov (United States)

    Zhang, Xiao; Tan, Saichun; Shi, Guangyu

    2018-02-01

    Satellite and human visual observation are two of the most important observation approaches for cloud cover. In this study, the total cloud cover (TCC) observed by MODIS onboard the Terra and Aqua satellites was compared with Synop meteorological station observations over the North China Plain and its surrounding regions for 11 years during daytime and 7 years during nighttime. The Synop data were recorded eight times a day at 3-h intervals. Linear interpolation was used to interpolate the Synop data to the MODIS overpass time in order to reduce the temporal deviation between the satellite and Synop observations. Results showed that MODIS-derived TCC had good consistency with the Synop observations; the correlation coefficients ranged from 0.56 in winter to 0.73 in summer for Terra MODIS, and from 0.55 in winter to 0.71 in summer for Aqua MODIS. However, they also had certain differences. On average, the MODIS-derived TCC was 15.16% higher than the Synop data, and this value was higher at nighttime (15.58%-16.64%) than daytime (12.74%-14.14%). The deviation between the MODIS and Synop TCC had large seasonal variation, being largest in winter (29.53%-31.07%) and smallest in summer (4.46%-6.07%). Analysis indicated that cloud with low cloud-top height and small cloud optical thickness was more likely to cause observation bias. Besides, an increase in the satellite view zenith angle, aerosol optical depth, or snow cover could lead to positively biased MODIS results, and this affect differed among different cloud types.

  9. IMPROVE THE ZY-3 HEIGHT ACCURACY USING ICESAT/GLAS LASER ALTIMETER DATA

    Directory of Open Access Journals (Sweden)

    G. Li

    2016-06-01

    Full Text Available ZY-3 is the first civilian high resolution stereo mapping satellite, which has been launched on 9th, Jan, 2012. The aim of ZY-3 satellite is to obtain high resolution stereo images and support the 1:50000 scale national surveying and mapping. Although ZY-3 has very high accuracy for direct geo-locations without GCPs (Ground Control Points, use of some GCPs is still indispensible for high precise stereo mapping. The GLAS (Geo-science Laser Altimetry System loaded on the ICESat (Ice Cloud and land Elevation Satellite, which is the first laser altimetry satellite for earth observation. GLAS has played an important role in the monitoring of polar ice sheets, the measuring of land topography and vegetation canopy heights after launched in 2003. Although GLAS has ended in 2009, the derived elevation dataset still can be used after selection by some criteria. In this paper, the ICESat/GLAS laser altimeter data is used as height reference data to improve the ZY-3 height accuracy. A selection method is proposed to obtain high precision GLAS elevation data. Two strategies to improve the ZY-3 height accuracy are introduced. One is the conventional bundle adjustment based on RFM and bias-compensated model, in which the GLAS footprint data is viewed as height control. The second is to correct the DSM (Digital Surface Model straightly by simple block adjustment, and the DSM is derived from the ZY-3 stereo imaging after freedom adjustment and dense image matching. The experimental result demonstrates that the height accuracy of ZY-3 without other GCPs can be improved to 3.0 meter after adding GLAS elevation data. What’s more, the comparison of the accuracy and efficiency between the two strategies is implemented for application.

  10. Library of Antifouling Surfaces Derived From Natural Amino Acids by Click Reaction.

    Science.gov (United States)

    Xu, Chen; Hu, Xin; Wang, Jie; Zhang, Ye-Min; Liu, Xiao-Jiu; Xie, Bin-Bin; Yao, Chen; Li, Yi; Li, Xin-Song

    2015-08-12

    Biofouling is of great concern in numerous applications ranging from ophthalmological implants to catheters, and from bioseparation to biosensors. In this report, a general and facile strategy to combat surface fouling is developed by grafting of amino acids onto polymer substrates to form zwitterionic structure through amino groups induced epoxy ring opening click reaction. First of all, a library of poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate) hydrogels with zwitterionic surfaces were prepared, resulting in the formation of pairs of carboxyl anions and protonated secondary amino cations. The analysis of attenuated total reflectance Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirmed the successful immobilization of amino acids on the hydrogel surfaces. After that, the contact angle and equilibrium water content of the modified hydrogels showed that the hydrogels exhibited improved hydrophilicity compared with the parent hydrogel. Furthermore, the protein deposition was evaluated by bicinchoninic acid assay using bovine serum albumin (BSA) and lysozyme as models. The results indicated that the performance of the hydrogels was determined by the nature of incorporated amino acid: the hydrogels incorporated with neutral amino acids had nonspecific antiadsorption capability to both BSA and lysozyme; the hydrogels incorporated with charged amino acids showed antiadsorption behaviors against protein with same charge and enhanced adsorption to the protein with opposite charge; the optimal antiadsorption performance was observed on the hydrogels incorporated with polar amino acids with a hydroxyl residual. The improvement of antiprotein fouling of the neutral amino acids grafted hydrogels can be ascribed to the formation of zwitterionic surfaces. Finally, a couple of soft contact lenses grafted with amino acids were fabricated having improved antifouling property and hydrophilicity. The result demonstrated the success of

  11. 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...

  12. Calibration of GOES-derived solar radiation data using a distributed network of surface measurements in Florida, USA

    Science.gov (United States)

    Sumner, David M.; Pathak, Chandra S.; Mecikalski, John R.; Paech, Simon J.; Wu, Qinglong; Sangoyomi, Taiye; Babcock, Roger W.; Walton, Raymond

    2008-01-01

    Solar radiation data are critically important for the estimation of evapotranspiration. Analysis of visible-channel data derived from Geostationary Operational Environmental Satellites (GOES) using radiative transfer modeling has been used to produce spatially- and temporally-distributed datasets of solar radiation. An extensive network of (pyranometer) surface measurements of solar radiation in the State of Florida has allowed refined calibration of a GOES-derived daily integrated radiation data product. This refinement of radiation data allowed for corrections of satellite sensor drift, satellite generational change, and consideration of the highly-variable cloudy conditions that are typical of Florida. To aid in calibration of a GOES-derived radiation product, solar radiation data for the period 1995–2004 from 58 field stations that are located throughout the State were compiled. The GOES radiation product was calibrated by way of a three-step process: 1) comparison with ground-based pyranometer measurements on clear reference days, 2) correcting for a bias related to cloud cover, and 3) deriving month-by-month bias correction factors. Pre-calibration results indicated good model performance, with a station-averaged model error of 2.2 MJ m–2 day–1 (13 percent). Calibration reduced errors to 1.7 MJ m–2 day–1 (10 percent) and also removed time- and cloudiness-related biases. The final dataset has been used to produce Statewide evapotranspiration estimates.

  13. Utilization of satellite-derived estimates of meteorological and land surface characteristics in the Land Surface Model for vast agricultural region territory

    Science.gov (United States)

    Muzylev, Eugene; Startseva, Zoya; Uspensky, Alexander; Volkova, Elena

    2015-04-01

    The method has been elaborated to evaluate the water and heat regime characteristics of the territory on a regional scale for the vegetation season based on a physical-mathematical model of water and heat exchange between vegetation covered land surface and atmosphere (LSM, Land Surface Model) appropriate for using satellite information on land surface and meteorological conditions. The developed model is intended for calculating soil water content, evapotranspiration (evaporation from bare soil and transpiration by vegetation), vertical water and heat fluxes as well as land surface and vegetation cover temperatures and vertical distributions of temperature and moisture in the active soil layer. Parameters of the model are soil and vegetation characteristics and input variables are meteorological characteristics. Their values have been obtained from ground-based observations at agricultural meteorological stations and satellite-based measurements by scanning radiometers AVHRR/NOAA, MODIS/EOS Terra and Aqua and SEVIRI (geostationary satellites Meteosat-9, -10). The AVHRR data have been used to build the estimates of three types of land surface temperature (LST): land skin temperature Tsg, air temperature at a level of vegetation cover Ta and efficient radiation temperature Tseff, emissivity E, normalized vegetation index NDVI, vegetation cover fraction B, leaf area index LAI, and precipitation. The set of estimates derived from MODIS data has comprised values of LST Tls, E, NDVI and LAI. The SEVIRI-based retrievals have included Tls, Ta, Е at daylight and nighttime, LAI (daily) and precipitation. The case study has been carried out for agricultural Central Black Earth region of the European Russia of 227,300 sq.km containing 7 regions of the Russian Federation for years 2009-2013 vegetation seasons. Estimates of described characteristics have been built with the help of the developed original and improved pre-existing methods and technologies of thematic processing

  14. Differential Proteomic Analysis of Human Placenta-Derived Mesenchymal Stem Cells Cultured on Normal Tissue Culture Surface and Hyaluronan-Coated Surface

    Directory of Open Access Journals (Sweden)

    Tzyy Yue Wong

    2016-01-01

    Full Text Available Our previous results showed that hyaluronan (HA preserved human placenta-derived mesenchymal stem cells (PDMSC in a slow cell cycling mode similar to quiescence, the pristine state of stem cells in vivo, and HA was found to prevent murine adipose-derived mesenchymal stem cells from senescence. Here, stable isotope labeling by amino acid in cell culture (SILAC proteomic profiling was used to evaluate the effects of HA on aging phenomenon in stem cells, comparing (1 old and young passage PDMSC cultured on normal tissue culture surface (TCS; (2 old passage on HA-coated surface (CHA compared to TCS; (3 old and young passage on CHA. The results indicated that senescence-associated protein transgelin (TAGLN was upregulated in old TCS. Protein CYR61, reportedly senescence-related, was downregulated in old CHA compared to old TCS. The SIRT1-interacting Nicotinamide phosphoribosyltransferase (NAMPT increased by 2.23-fold in old CHA compared to old TCS, and is 0.48-fold lower in old TCS compared to young TCS. Results also indicated that components of endoplasmic reticulum associated degradation (ERAD pathway were upregulated in old CHA compared to old TCS cells, potentially for overcoming stress to maintain cell function and suppress senescence. Our data points to pathways that may be targeted by HA to maintain stem cells youth.

  15. Wave Height and Horizon Dip

    NARCIS (Netherlands)

    Van Der Werf, Siebren; Shokaryev, Igor

    2015-01-01

    A mariner who takes the height of the sun or a star to find his position at sea, must correct his observation for horizon dip. Throughout history, dip values have been tabulated based on the idealized assumption of a perfectly flat sea. Literature on wave height correction for dip is scarce,

  16. 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...

  17. Thrombospondin-derived peptide attenuates Sjögren's syndrome-associated ocular surface inflammation in mice.

    Science.gov (United States)

    Contreras Ruiz, L; Mir, F A; Turpie, B; Masli, S

    2017-04-01

    Sjögren's syndrome is the second most common rheumatic disease in which autoimmune response targets exocrine glands (salivary and lacrimal glands) result in clinical symptoms of dry mouth and dry eye. Inflammation of the lacrimal gland induces tear abnormalities that contribute to the inflammation of the ocular surface, which includes ocular mucosa. Thrombospondin-1 (TSP-1) plays a critical regulatory role in the ocular mucosa and as such TSP-1 -/- mice develop spontaneously chronic ocular surface inflammation associated with Sjögren's syndrome. The autoimmune pathology is also accompanied by a peripheral imbalance in regulatory (T reg ) and inflammatory Th17 effectors. In this study, we demonstrate an in-vitro effect of a CD47-binding TSP-derived peptide in the induction of transforming growth factor (TGF)-β1-secreting forkhead box protein 2 (Foxp3 + ) T regs from activated CD4 + CD25 - T cells and the inhibition of pathogenic T helper type 17 (Th17)-promoting interleukin (IL)-23 derived from antigen-presenting cells. The in-vivo administration of this peptide promotes Foxp3 + T reg induction and inhibition of Th17 development. Consistent with these results, topical administration of CD47-binding TSP peptide, both before and after the onset of the disease, attenuates clinical symptoms of SS-associated dry eye in TSP-1 -/- mice. Augmented expression of Foxp3 detected in the draining lymph nodes of TSP peptide -treated mice compared to those treated with control peptide suggests the ability of TSP peptide to restore peripheral immune imbalance. Thus, our results suggest that TSP-derived peptide attenuates Sjögren's syndrome-associated dry eye and autoimmune inflammation by preventing Th17 development while promoting the induction of T regs . Collectively, our data identify TSP-derived peptide as a novel therapeutic option to treat autoimmune diseases. © 2017 British Society for Immunology.

  18. Derivation of Land Surface Temperature for Landsat-8 TIRS Using a Split Window Algorithm

    Directory of Open Access Journals (Sweden)

    Offer Rozenstein

    2014-03-01

    Full Text Available Land surface temperature (LST is one of the most important variables measured by satellite remote sensing. Public domain data are available from the newly operational Landsat-8 Thermal Infrared Sensor (TIRS. This paper presents an adjustment of the split window algorithm (SWA for TIRS that uses atmospheric transmittance and land surface emissivity (LSE as inputs. Various alternatives for estimating these SWA inputs are reviewed, and a sensitivity analysis of the SWA to misestimating the input parameters is performed. The accuracy of the current development was assessed using simulated Modtran data. The root mean square error (RMSE of the simulated LST was calculated as 0.93 °C. This SWA development is leading to progress in the determination of LST by Landsat-8 TIRS.

  19. Cost Surface-Derived Least-Cost Paths: A Case Study from Iron Age Orkney

    Directory of Open Access Journals (Sweden)

    Brian Rahn

    2005-12-01

    Full Text Available In recent years, GIS landscape models have begun to move towards more sophisticated techniques for representing the land surface in order to analyse site territories, pathways and travel costs. Many of the major commercial GIS packages now offer the ability to generate anisotropic cost surfaces. In addition, recent papers have proposed methodologies for generating cost surfaces to model social preferences affecting travel (Lee and Stucky 1998; Llobera 2000. In terms of practical applications, however, GIS models of catchment areas and paths between sites continue to be dominated by those constructed on the basis of slope alone. In parallel with this, regional analyses of site location, with few exceptions, have been undertaken either within large land masses, largely ignoring the effects of rivers, lakes and the sea on travel costs and affordances, or within single islands, neglecting travel to other neighbouring islands or the mainland. The reasons for this appear to be twofold: first, there is little information available on travel costs and travel rates using pre-industrial transportation technology, beyond very general statements; second, critical analysis of what constitutes an 'acceptable' travel distance is lacking, especially in situations where both water and land transport are possibilities. This article presents some preliminary results from a research project examining the location and distribution of Middle Iron Age sites (brochs in the landscape of Orkney, Northern Scotland. It employs a terrain model, taking into account differing friction values for land and water surfaces, as well as the nature of the shoreline (cliffs, beaches and how this affects access from land to sea and vice versa. It also attempts to model pathways between sites following three friction models: lowest-energy, lowest-visibility (hidden and highest-visibility (exposed.

  20. An efficient physically based parameterization to derive surface solar irradiance based on satellite atmospheric products

    Science.gov (United States)

    Qin, Jun; Tang, Wenjun; Yang, Kun; Lu, Ning; Niu, Xiaolei; Liang, Shunlin

    2015-05-01

    Surface solar irradiance (SSI) is required in a wide range of scientific researches and practical applications. Many parameterization schemes are developed to estimate it using routinely measured meteorological variables, since SSI is directly measured at a very limited number of stations. Even so, meteorological stations are still sparse, especially in remote areas. Remote sensing can be used to map spatiotemporally continuous SSI. Considering the huge amount of satellite data, coarse-resolution SSI has been estimated for reducing the computational burden when the estimation is based on a complex radiative transfer model. On the other hand, many empirical relationships are used to enhance the retrieval efficiency, but the accuracy cannot be guaranteed out of regions where they are locally calibrated. In this study, an efficient physically based parameterization is proposed to balance computational efficiency and retrieval accuracy for SSI estimation. In this parameterization, the transmittances for gases, aerosols, and clouds are all handled in full band form and the multiple reflections between the atmosphere and surface are explicitly taken into account. The newly proposed parameterization is applied to estimate SSI with both Moderate Resolution Imaging Spectroradiometer (MODIS) atmospheric and land products as inputs. These retrievals are validated against in situ measurements at the Surface Radiation Budget Network and at the North China Plain on an instantaneous basis, and moreover, they are validated and compared with Global Energy and Water Exchanges-Surface Radiation Budget and International Satellite Cloud Climatology Project-flux data SSI estimates at radiation stations of China Meteorological Administration on a daily mean basis. The estimation results indicates that the newly proposed SSI estimation scheme can effectively retrieve SSI based on MODIS products with mean root-mean-square errors of about 100 Wm- 1 and 35 Wm- 1 on an instantaneous and daily

  1. Cell-Surface Proteomics Identifies Lineage-Specific Markers of Embryo-Derived Stem Cells

    OpenAIRE

    Rugg-Gunn, Peter J.; Cox, Brian J.; Lanner, Fredrik; Sharma, Parveen; Ignatchenko, Vladimir; McDonald, Angela C.H.; Garner, Jodi; Gramolini, Anthony O.; Rossant, Janet; Kislinger, Thomas

    2012-01-01

    Summary The advent of reprogramming and its impact on stem cell biology has renewed interest in lineage restriction in mammalian embryos, the source of embryonic (ES), epiblast (EpiSC), trophoblast (TS), and extraembryonic endoderm (XEN) stem cell lineages. Isolation of specific cell types during stem cell differentiation and reprogramming, and also directly from embryos, is a major technical challenge because few cell-surface proteins are known that can distinguish each cell type. We provide...

  2. Surface Mass Balance of the Greenland Ice Sheet Derived from Paleoclimate Reanalysis

    Science.gov (United States)

    Badgeley, J.; Steig, E. J.; Hakim, G. J.; Anderson, J.; Tardif, R.

    2017-12-01

    Modeling past ice-sheet behavior requires independent knowledge of past surface mass balance. Though models provide useful insight into ice-sheet response to climate forcing, if past climate is unknown, then ascertaining the rate and extent of past ice-sheet change is limited to geological and geophysical constraints. We use a novel data-assimilation framework developed under the Last Millennium Reanalysis Project (Hakim et al., 2016) to reconstruct past climate over ice sheets with the intent of creating an independent surface mass balance record for paleo ice-sheet modeling. Paleoclimate data assimilation combines the physics of climate models and the time series evidence of proxy records in an offline, ensemble-based approach. This framework allows for the assimilation of numerous proxy records and archive types while maintaining spatial consistency with known climate dynamics and physics captured by the models. In our reconstruction, we use the Community Climate System Model version 4, CMIP5 last millennium simulation (Taylor et al., 2012; Landrum et al., 2013) and a nearly complete database of ice core oxygen isotope records to reconstruct Holocene surface temperature and precipitation over the Greenland Ice Sheet on a decadal timescale. By applying a seasonality to this reconstruction (from the TraCE-21ka simulation; Liu et al., 2009), our reanalysis can be used in seasonally-based surface mass balance models. Here we discuss the methods behind our reanalysis and the performance of our reconstruction through prediction of unassimilated proxy records and comparison to paleoclimate reconstructions and reanalysis products.

  3. Nonenzymatic Reactions above Phospholipid Surfaces of Biological Membranes: Reactivity of Phospholipids and Their Oxidation Derivatives

    Science.gov (United States)

    Solís-Calero, Christian; Ortega-Castro, Joaquín; Frau, Juan; Muñoz, Francisco

    2015-01-01

    Phospholipids play multiple and essential roles in cells, as components of biological membranes. Although phospholipid bilayers provide the supporting matrix and surface for many enzymatic reactions, their inherent reactivity and possible catalytic role have not been highlighted. As other biomolecules, phospholipids are frequent targets of nonenzymatic modifications by reactive substances including oxidants and glycating agents which conduct to the formation of advanced lipoxidation end products (ALEs) and advanced glycation end products (AGEs). There are some theoretical studies about the mechanisms of reactions related to these processes on phosphatidylethanolamine surfaces, which hypothesize that cell membrane phospholipids surface environment could enhance some reactions through a catalyst effect. On the other hand, the phospholipid bilayers are susceptible to oxidative damage by oxidant agents as reactive oxygen species (ROS). Molecular dynamics simulations performed on phospholipid bilayers models, which include modified phospholipids by these reactions and subsequent reactions that conduct to formation of ALEs and AGEs, have revealed changes in the molecular interactions and biophysical properties of these bilayers as consequence of these reactions. Then, more studies are desirable which could correlate the biophysics of modified phospholipids with metabolism in processes such as aging and diseases such as diabetes, atherosclerosis, and Alzheimer's disease. PMID:25977746

  4. Statistical approach for derivation of quantitative acceptance criteria for radioactive wastes to near surface disposal facility

    International Nuclear Information System (INIS)

    Park, Jin Beak; Park, Joo Wan; Lee, Eun Yong; Kim, Chang Lak

    2003-01-01

    For reference human intrusion scenarios constructed in previous study, a probabilistic safety assessment to derive the radionuclide concentration limits for the low- and intermediate- level radioactive waste disposal facility is conducted. Statistical approach by the latin hypercube sampling method is introduced and new assumptions about the disposal facility system are examined and discussed. In our previous study of deterministic approach, the post construction scenarios appeared as most limiting scenario to derive the radionuclide concentration limits. Whereas, in this statistical approach, the post drilling and the post construction scenarios are mutually competing for the scenario selection according to which radionuclides are more important in safety assessment context. Introduction of new assumption shows that the post drilling scenario can play an important role as the limiting scenario instead of the post-construction scenario. When we compare the concentration limits between the previous and this study, concentrations of radionuclides such as Nb-94, Cs-137 and alpha-emitting radionuclides show elevated values than the case of the previous study. Remaining radionuclides such as Sr-90, Tc-99 I-129, Ni-59 and Ni-63 show lower values than the case of the previous study

  5. CALIOP-based Biomass Burning Smoke Plume Injection Height

    Science.gov (United States)

    Soja, A. J.; Choi, H. D.; Fairlie, T. D.; Pouliot, G.; Baker, K. R.; Winker, D. M.; Trepte, C. R.; Szykman, J.

    2017-12-01

    Carbon and aerosols are cycled between terrestrial and atmosphere environments during fire events, and these emissions have strong feedbacks to near-field weather, air quality, and longer-term climate systems. Fire severity and burned area are under the control of weather and climate, and fire emissions have the potential to alter numerous land and atmospheric processes that, in turn, feedback to and interact with climate systems (e.g., changes in patterns of precipitation, black/brown carbon deposition on ice/snow, alteration in landscape and atmospheric/cloud albedo). If plume injection height is incorrectly estimated, then the transport and deposition of those emissions will also be incorrect. The heights to which smoke is injected governs short- or long-range transport, which influences surface pollution, cloud interaction (altered albedo), and modifies patterns of precipitation (cloud condensation nuclei). We are working with the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) science team and other stakeholder agencies, primarily the Environmental Protection Agency and regional partners, to generate a biomass burning (BB) plume injection height database using multiple platforms, sensors and models (CALIOP, MODIS, NOAA HMS, Langley Trajectory Model). These data have the capacity to provide enhanced smoke plume injection height parameterization in regional, national and international scientific and air quality models. Statistics that link fire behavior and weather to plume rise are crucial for verifying and enhancing plume rise parameterization in local-, regional- and global-scale models used for air quality, chemical transport and climate. Specifically, we will present: (1) a methodology that links BB injection height and CALIOP air parcels to specific fires; (2) the daily evolution of smoke plumes for specific fires; (3) plumes transport and deposited on the Greenland Ice Sheet; and (4) compare CALIOP-derived smoke plume injection

  6. 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

  7. Land Surface Microwave Emissivities Derived from AMSR-E and MODIS Measurements with Advanced Quality Control

    Science.gov (United States)

    Moncet, Jean-Luc; Liang, Pan; Galantowicz, John F.; Lipton, Alan E.; Uymin, Gennady; Prigent, Catherine; Grassotti, Christopher

    2011-01-01

    A microwave emissivity database has been developed with data from the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) and with ancillary land surface temperature (LST) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the same Aqua spacecraft. The primary intended application of the database is to provide surface emissivity constraints in atmospheric and surface property retrieval or assimilation. An additional application is to serve as a dynamic indicator of land surface properties relevant to climate change monitoring. The precision of the emissivity data is estimated to be significantly better than in prior databases from other sensors due to the precise collocation with high-quality MODIS LST data and due to the quality control features of our data analysis system. The accuracy of the emissivities in deserts and semi-arid regions is enhanced by applying, in those regions, a version of the emissivity retrieval algorithm that accounts for the penetration of microwave radiation through dry soil with diurnally varying vertical temperature gradients. These results suggest that this penetration effect is more widespread and more significant to interpretation of passive microwave measurements than had been previously established. Emissivity coverage in areas where persistent cloudiness interferes with the availability of MODIS LST data is achieved using a classification-based method to spread emissivity data from less-cloudy areas that have similar microwave surface properties. Evaluations and analyses of the emissivity products over homogeneous snow-free areas are presented, including application to retrieval of soil temperature profiles. Spatial inhomogeneities are the largest in the vicinity of large water bodies due to the large water/land emissivity contrast and give rise to large apparent temporal variability in the retrieved emissivities when satellite footprint locations vary over time. This issue will be dealt with in the future by

  8. Derivative matrices of a skew ray for spherical boundary surfaces and their applications in system analysis and design.

    Science.gov (United States)

    Lin, Psang Dain

    2014-05-10

    In a previous paper [Appl. Opt.52, 4151 (2013)], we presented the first- and second-order derivatives of a ray for a flat boundary surface to design prisms. In this paper, that scheme is extended to determine the Jacobian and Hessian matrices of a skew ray as it is reflected/refracted at a spherical boundary surface. The validity of the proposed approach as an analysis and design tool is demonstrated using an axis-symmetrical system for illustration purpose. It is found that these two matrices can provide the search direction used by existing gradient-based schemes to minimize the merit function during the optimization stage of the optical system design process. It is also possible to make the optical system designs more automatic, if the image defects can be extracted from the Jacobian and Hessian matrices of a skew ray.

  9. Preliminary objective regionalization of the Mediterranean basin derived from surface-wave tomography

    Directory of Open Access Journals (Sweden)

    L. Pujades

    1997-06-01

    Full Text Available An objective regionalization of the Mediterranean basin is derived from a tomographic study based on the fundamental mode of Rayleigh waves. The database is formed by seismic wavetrains recorded at very-broadband stations belonging to MedNet and other cooperative stations, located in the Mediterranean area. The data treatment consists of application of spectral filtering techniques aimed to determine path-averaged group velocities, computation of local group velocity maps for some periods and classification of the studied area in several homogeneous regions according to Principal Component Analysis (PCA and Average Linkage (AL algorithms. Finally, the group velocity dispersion curves representing each homogeneous region are compared and possible correlation between these regions and seismotectonic and structural characteristics are discussed.

  10. Transient flow between aquifers and surface water: analytically derived field-scale hydraulic heads and fluxes

    Directory of Open Access Journals (Sweden)

    G. H. de Rooij

    2012-03-01

    Full Text Available The increasing importance of catchment-scale and basin-scale models of the hydrological cycle makes it desirable to have a simple, yet physically realistic model for lateral subsurface water flow. As a first building block towards such a model, analytical solutions are presented for horizontal groundwater flow to surface waters held at prescribed water levels for aquifers with parallel and radial flow. The solutions are valid for a wide array of initial and boundary conditions and additions or withdrawals of water, and can handle discharge into as well as lateral infiltration from the surface water. Expressions for the average hydraulic head, the flux to or from the surface water, and the aquifer-scale hydraulic conductivity are developed to provide output at the scale of the modelled system rather than just point-scale values. The upscaled conductivity is time-variant. It does not depend on the magnitude of the flux but is determined by medium properties as well as the external forcings that drive the flow. For the systems studied, with lateral travel distances not exceeding 10 m, the circular aquifers respond very differently from the infinite-strip aquifers. The modelled fluxes are sensitive to the magnitude of the storage coefficient. For phreatic aquifers a value of 0.2 is argued to be representative, but considerable variations are likely. The effect of varying distributions over the day of recharge damps out rapidly; a soil water model that can provide accurate daily totals is preferable over a less accurate model hat correctly estimates the timing of recharge peaks.

  11. Probing the switching state of a surface-mounted azobenzene derivative using femtosecond XUV photoemission

    Science.gov (United States)

    Grunau, Jan; Heinemann, Nils; Rohwer, Timm; Zargarani, Dordaneh; Kuhn, Sonja; Jung, Ullrich; Kipp, Lutz; Magnussen, Olaf; Herges, Rainer; Bauer, Michael

    2012-03-01

    Photoemission spectroscopy using femtosecond XUV light pulses is applied to probe the isomerization state of the molecular switch 3-(4-(4-hexyl-phenylazo)-phenoxy)-propane-1-thiol deposited by liquid phase self-assembly on Au(111). Spectral shifts of valence-electronic signatures that we associate with the carbon C2s orbital enable us to distinguish the trans and the cis isomerization state of the adsorbed molecules. These preliminary results envision the potential to probe reversible switching processes of surface-mounted molecules in real time by tracking the temporal evolution of the electronic and nuclear degrees of freedom in a femtosecond XUV photoemission experiment.

  12. Assessment of Surface Water Contamination from Coalbed Methane Fracturing-Derived Volatile Contaminants in Sullivan County, Indiana, USA.

    Science.gov (United States)

    Meszaros, Nicholas; Subedi, Bikram; Stamets, Tristan; Shifa, Naima

    2017-09-01

    There is a growing concern over the contamination of surface water and the associated environmental and public health consequences from the recent proliferation of hydraulic fracturing in the USA. Petroleum hydrocarbon-derived contaminants of concern [benzene, toluene, ethylbenzene, and xylenes (BTEX)] and various dissolved cations and anions were spatially determined in surface waters around 15 coalbed methane fracking wells in Sullivan County, IN, USA. At least one BTEX compound was detected in 69% of sampling sites (n = 13) and 23% of sampling sites were found to be contaminated with all of the BTEX compounds. Toluene was the most common BTEX compound detected across all sampling sites, both upstream and downstream from coalbed methane fracking wells. The average concentration of toluene at a reservoir and its outlet nearby the fracking wells was ~2× higher than other downstream sites. However, one of the upstream sites was found to be contaminated with BTEX at similar concentrations as in a reservoir site nearby the fracking well. Calcium (~60 ppm) and sulfates (~175 ppm) were the dominant cations and anions, respectively, in surface water around the fracking sites. This study represents the first report of BTEX contamination in surface water from coalbed methane hydraulic fracturing wells.

  13. Do surfaces of positive electrostatic potential on different halogen derivatives in molecules attract? like attracting like!

    Science.gov (United States)

    Varadwaj, Arpita; Varadwaj, Pradeep R; Yamashita, Koichi

    2018-03-15

    Coulomb's law states that like charges repel, and unlike charges attract. However, it has recently been theoretically revealed that two similarly charged conducting spheres will almost always attract each other when both are in close proximity. Using multiscale first principles calculations, we illustrate practical examples of several intermolecular complexes that are formed by the consequences of attraction between positive atomic sites of similar or dissimilar electrostatic surface potential on interacting molecules. The results of the quantum theory of atoms in molecules and symmetry adapted perturbation theory support the attraction between the positive sites, characterizing the F•••X (X = F, Cl, Br) intermolecular interactions in a series of 20 binary complexes as closed-shell type, although the molecular electrostatic surface potential approach does not (a failure!). Dispersion that has an r -6 dependence, where r is the equilibrium distance of separation, is found to be the sole driving force pushing the two positive sites to attract. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  14. Linking Satellite Derived Land Surface Temperature with Cholera: A Case Study for South Sudan

    Science.gov (United States)

    Aldaach, H. S. V.; Jutla, A.; Akanda, A. S.; Colwell, R. R.

    2014-12-01

    A sudden onset of cholera in South Sudan, in April 2014 in Northern Bari in Juba town resulted in more than 400 cholera cases after four weeks of initial outbreak with a case of fatality rate of CFR 5.4%. The total number of reported cholera cases for the period of April to July, 2014 were 5,141 including 114 deaths. With the limited efficacy of cholera vaccines, it is necessary to develop mechanisms to predict cholera occurrence and thereafter devise intervention strategies for mitigating impacts of the disease. Hydroclimatic processes, primarily precipitation and air temperature are related to epidemic and episodic outbreak of cholera. However, due to coarse resolution of both datasets, it is not possible to precisely locate the geographical location of disease. Here, using Land Surface Temperature (LST) from MODIS sensors, we have developed an algorithm to identify regions susceptible for cholera. Conditions for occurrence of cholera were detectable at least one month in advance in South Sudan and were statistically sensitive to hydroclimatic anomalies of land surface and air temperature, and precipitation. Our results indicate significant spatial and temporal averaging required to infer usable information from LST over South Sudan. Preliminary results that geographically location of cholera outbreak was identifiable within 1km resolution of the LST data.

  15. 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

  16. D-glucose derived novel gemini surfactants: synthesis and study of their surface properties, interaction with DNA, and cytotoxicity.

    Science.gov (United States)

    Kumar, Vikash; Chatterjee, Amrita; Kumar, Nupur; Ganguly, Anasuya; Chakraborty, Indranil; Banerjee, Mainak

    2014-10-09

    Four new D-glucose derived m-s-m type gemini surfactants with variable spacer and tail length have been synthesized by a simple and efficient synthetic methodology utilizing the free C-3 hydroxy group of diisopropylidene glucose. The synthetic route to these gemini surfactants with a quaternary ammonium group as polar head group involves a sequence of simple reactions including alkylation, imine formation, quaternization of amine etc. The surface properties of the new geminis were evaluated by surface tension and conductivity measurements. These gemini surfactants showed low cytotoxicity by MTT assay on HeLa cell line. The DNA binding capabilities of these surfactants were determined by agarose gel electrophoresis, fluorescence titration, and DLS experiments. The preliminary studies by agarose gel electrophoresis indicated chain length dependent DNA binding abilities, further supported by ethidium bromide exclusion experiments. Two of the D-glucose derived gemini surfactants showed effective binding with pET-28a plasmid DNA (pDNA) at relatively low N/P ratio (i.e., cationic nitrogen/DNA phosphate molar ratio). Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Thermal measurements of dark and bright surface features on Vesta as derived from Dawn/VIR

    Science.gov (United States)

    Tosi, Federico; Capria, Maria Teresa; De Sanctis, M.C.; Combe, J.-Ph.; Zambon, F.; Nathues, A.; Schröder, S.E.; Li, J.-Y.; Palomba, E.; Longobardo, A.; Blewett, D.T.; Denevi, B.W.; Palmer, E.; Capaccioni, F.; Ammannito, E.; Titus, Timothy N.; Mittlefehldt, D.W.; Sunshine, J.M.; Russell, C.T.; Raymond, C.A.; Dawn/VIR Team,

    2014-01-01

    Remote sensing data acquired during Dawn’s orbital mission at Vesta showed several local concentrations of high-albedo (bright) and low-albedo (dark) material units, in addition to spectrally distinct meteorite impact ejecta. The thermal behavior of such areas seen at local scale (1-10 km) is related to physical properties that can provide information about the origin of those materials. We use Dawn’s Visible and InfraRed (VIR) mapping spectrometer hyperspectral data to retrieve surface temperatures and emissivities, with high accuracy as long as temperatures are greater than 220 K. Some of the dark and bright features were observed multiple times by VIR in the various mission phases at variable spatial resolution, illumination and observation angles, local solar time, and heliocentric distance. This work presents the first temperature maps and spectral emissivities of several kilometer-scale dark and bright material units on Vesta. Results retrieved from the infrared data acquired by VIR show that bright regions generally correspond to regions with lower temperature, while dark regions correspond to areas with higher temperature. During maximum daily insolation and in the range of heliocentric distances explored by Dawn, i.e. 2.23-2.54 AU, the warmest dark unit found on Vesta rises to a temperature of 273 K, while bright units observed under comparable conditions do not exceed 266 K. Similarly, dark units appear to have higher emissivity on average compared to bright units. Dark-material units show a weak anticorrelation between temperature and albedo, whereas the relation is stronger for bright material units observed under the same conditions. Individual features may show either evanescent or distinct margins in the thermal images, as a consequence of the cohesion of the surface material. Finally, for the two categories of dark and bright materials, we were able to highlight the influence of heliocentric distance on surface temperatures, and estimate an

  18. Use of the discriminant Fourier-derived cepstrum with feature-level post-processing for surface electromyographic signal classification

    International Nuclear Information System (INIS)

    Chen, Xinpu; Zhu, Xiangyang; Zhang, Dingguo

    2009-01-01

    Myoelectrical pattern classification is a crucial part in multi-functional prosthesis control. This paper investigates a discriminant Fourier-derived cepstrum (DFC) and feature-level post-processing (FLPP) to discriminate hand and wrist motions using the surface electromyographic signal. The Fourier-derived cepstrum takes advantage of the Fourier magnitude or sub-band power energy of signals directly and provides flexible use of spectral information changing with different motions. Appropriate cepstral coefficients are selected by a proposed separability criterion to construct DFC features. For the post-processing, FLPP which combines features from several analysis windows is used to improve the feature performance further. In this work, two classifiers (a linear discriminant classifier and quadratic discriminant classifier) without hyper-parameter optimization are employed to simplify the training procedure and avoid the possible bias of feature evaluation. Experimental results of the 11-motion problem show that the proposed DFC feature outperforms traditional features such as time-domain statistics and autoregressive-derived cepstrum in terms of the classification accuracy, and it is a promising method for the multi-functionality and high-accuracy control of myoelectric prostheses

  19. Alcohol Dehydrogenation on Kraft Lignin-Derived Chars with Surface Basicity

    Directory of Open Access Journals (Sweden)

    Francisco J. García-Mateos

    2017-10-01

    Full Text Available The properties of lignin and its potential as a renewable source make it an ideal precursor for carbon products. Specifically, the high content of Na observed in Kraft lignin makes this industrial by-product an interesting precursor for the preparation of catalysts for different applications. In this work, basic activated carbons with different textural properties and surface chemistry were obtained from Kraft lignin by direct carbonization at various temperatures. The influence of a further washing treatment and partial gasification with CO2 was also evaluated. The carbon catalysts were tested as catalysts for the alcohol decomposition reaction. In this sense, 2-propanol, a molecule widely used for testing the acidic-basic character of heterogeneous catalysts, was selectively transformed into acetone, meanwhile, ethanol and methanol yielded mainly acetaldehyde and formaldehyde, respectively.

  20. Rehabilitation Closure Criteria Assessment Using High Resolution Photogrammetrically Derived Surface Models

    Science.gov (United States)

    Fletcher, A. T.; Erskine, P. D.

    2013-08-01

    Relinquishment of mined land is unlikely to occur without compelling evidence that post mine landforms have a sustainable vegetation cover and represent a minimal liability to subsequent land users. Gully and rill erosion result in unstable landforms create unsafe landscapes for commonly targeted post mine land uses, such as grazing. The photogrammetric products of two small Unmanned Aerial Vehicle (UAV) platforms were compared as a means of delineating erosion gullies and comparing vegetation in rehabilitation at an open cut coal mine in the Bowen Basin, Queensland. Erosion gullies were clearly visible in both UAV products at 5 cm resolution; however, target illumination and photogrammetric processing methods largely determined the ability to identify erosion from surface models. Individual tree canopies were clearly visible in both products, as were phenological traits such as leaf flushing and flowering. The high spatial resolution resulted in unreliable detection of tree crowns in both processing methods.

  1. REHABILITATION CLOSURE CRITERIA ASSESSMENT USING HIGH RESOLUTION PHOTOGRAMMETRICALLY DERIVED SURFACE MODELS

    Directory of Open Access Journals (Sweden)

    A. T. Fletcher

    2013-08-01

    Full Text Available Relinquishment of mined land is unlikely to occur without compelling evidence that post mine landforms have a sustainable vegetation cover and represent a minimal liability to subsequent land users. Gully and rill erosion result in unstable landforms create unsafe landscapes for commonly targeted post mine land uses, such as grazing. The photogrammetric products of two small Unmanned Aerial Vehicle (UAV platforms were compared as a means of delineating erosion gullies and comparing vegetation in rehabilitation at an open cut coal mine in the Bowen Basin, Queensland. Erosion gullies were clearly visible in both UAV products at 5 cm resolution; however, target illumination and photogrammetric processing methods largely determined the ability to identify erosion from surface models. Individual tree canopies were clearly visible in both products, as were phenological traits such as leaf flushing and flowering. The high spatial resolution resulted in unreliable detection of tree crowns in both processing methods.

  2. Roll Damping Derivatives from Generalized Lifting-Surface Theory and Wind Tunnel Forced-Oscillation Tests

    Science.gov (United States)

    Pototzky, Anthony S; Murphy, Patrick C.

    2014-01-01

    Improving aerodynamic models for adverse loss-of-control conditions in flight is an area being researched under the NASA Aviation Safety Program. Aerodynamic models appropriate for loss of control conditions require a more general mathematical representation to predict nonlinear unsteady behaviors. As more general aerodynamic models are studied that include nonlinear higher order effects, the possibility of measurements that confound aerodynamic and structural responses are probable. In this study an initial step is taken to look at including structural flexibility in analysis of rigid-body forced-oscillation testing that accounts for dynamic rig, sting and balance flexibility. Because of the significant testing required and associated costs in a general study, it makes sense to capitalize on low cost analytical methods where possible, especially where structural flexibility can be accounted for by a low cost method. This paper provides an initial look at using linear lifting surface theory applied to rigid-body aircraft roll forced-oscillation tests.

  3. Wafer-Scale Nanopillars Derived from Block Copolymer Lithography for Surface-Enhanced Raman Spectroscopy

    DEFF Research Database (Denmark)

    Li, Tao; Wu, Kaiyu; Rindzevicius, Tomas

    2016-01-01

    We report a novel nanofabrication process via block copolymer lithography using solvent vapor annealing. The nanolithography process is facile and scalable, enabling fabrication of highly ordered periodic patterns over entire wafers as substrates for surface-enhanced Raman spectroscopy (SERS......). Direct silicon etching with high aspect ratio templated by the block copolymer mask is realized without any intermediate layer or external precursors. Uniquely, an atomic layer deposition (ALD)-assisted method is introduced to allow reversing of the morphology relative to the initial pattern. As a result......, highly ordered silicon nanopillar arrays are fabricated with controlled aspect ratios. After metallization, the resulting nanopillar arrays are suitable for SERS applications. These structures readily exhibit an average SERS enhancement factor of above 108, SERS uniformities of 8.5% relative standard...

  4. VAR2CSA expression on the surface of placenta-derived Plasmodium falciparum-infected erythrocytes

    DEFF Research Database (Denmark)

    Magistrado, Pamela; Salanti, Ali; Tuikue Ndam, Nicaise G

    2008-01-01

    intervillous space and parasite antigens. Both placental and chondroitin sulphate A-selected parasites have high-level transcripts of a unique var gene named var2csa. However, VAR2CSA has not been consistently found by proteomic analysis of placental parasites. Contrary to this, we found VAR2CSA expressed...... on the surface of infected erythrocytes from placenta. Importantly, this was achieved with cross-reactive antibodies against VAR2CSA.......Malaria remains a major threat, in sub-Saharan Africa primarily, and the most deadly infections are those with Plasmodium falciparum. Pregnancy-associated malaria is a clinically important complication of infection; it results from a unique interaction between proteoglycans in the placental...

  5. Modern sedimentation patterns in Laguna de Medina, Southern Spain, derived from lake surface and soil samples

    Science.gov (United States)

    van ´t Hoff, Jasmijn; Schröder, Tabea; Reicherter, Klaus; Held, Peter; Melles, Martin

    2016-04-01

    In September 2014 and March 2015, a 25.66 m long sediment core (Co1313) was retrieved from the centre of Laguna de Medina, a small endorheic salt lake in Cádiz, SW Spain. This record covers the last 9.000 years, thus providing an unique archive for Holocene climatic and environmental changes with extraordinary high temporal resolution. For a better understanding of the palaeoenvironmental proxies to be analysed on the sediment core, the modern processes of sediment formation in the lake and its catchment under known environmental conditions were investigated on a set of 46 lake sediment surface samples and 32 soil surface sediment samples from the lake and the close surroundings, respectively. These samples were analysed for bulk mineralogy (XRD), chemical composition (XRF), grain-size distribution (laser scanner), and carbonate, total organic carbon (TOC), nitrogen (TN) and sulphur (TS) contents (elemental analyser). Based on the mineralogical, geochemical and granulometrical data, the lake can be divided into four zones. The northern shore is characterized by particularly high quartz contents and coarse grain sizes. This reflects input from ancient terraces of the Guadalete River that are exposed in that area. The southern shore is characterised by high calcite contents due to sediment supply from the Cretaceous ´Capas rojaś, a series of Subbetic deep-water marl- and limestones. The southeastern and to a lesser extend the northwestern shores show particularly high dolomite contents, reflecting the Triassic dolomites outcroping in the southeastern catchment. The southeastern shore furthermore is also influenced by strong terrestrial input of the Triassic Keuper facies from the most important inlet, Arroyo Fuente Bermeja, as reflected by high contents of Ti, K, Al, Fe, Rb in the lake sediments. The last zone comprises only a small part of the western shore and is characterized by a relatively high gypsum amount. This does not reflect the geology in the catchment

  6. Mendelian randomization study of height and risk of colorectal cancer

    Science.gov (United States)

    Thrift, Aaron P; Gong, Jian; Peters, Ulrike; Chang-Claude, Jenny; Rudolph, Anja; Slattery, Martha L; Chan, Andrew T; Esko, Tonu; Wood, Andrew R; Yang, Jian; Vedantam, Sailaja; Gustafsson, Stefan; Pers, Tune H; Baron, John A; Bezieau, Stéphane; Küry, Sébastien; Ogino, Shuji; Berndt, Sonja I; Casey, Graham; Haile, Robert W; Du, Mengmeng; Harrison, Tabitha A; Thornquist, Mark; Duggan, David J; Le Marchand, Loic; Lemire, Mathieu; Lindor, Noralane M; Seminara, Daniela; Song, Mingyang; Thibodeau, Stephen N; Cotterchio, Michelle; Win, Aung Ko; Jenkins, Mark A; Hopper, John L; Ulrich, Cornelia M; Potter, John D; Newcomb, Polly A; Schoen, Robert E; Hoffmeister, Michael; Brenner, Hermann; White, Emily; Hsu, Li; Campbell, Peter T

    2015-01-01

    Background: For men and women, taller height is associated with increased risk of all cancers combined. For colorectal cancer (CRC), it is unclear whether the differential association of height by sex is real or is due to confounding or bias inherent in observational studies. We performed a Mendelian randomization study to examine the association between height and CRC risk. Methods: To minimize confounding and bias, we derived a weighted genetic risk score predicting height (using 696 genetic variants associated with height) in 10 226 CRC cases and 10 286 controls. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) for associations between height, genetically predicted height and CRC. Results: Using conventional methods, increased height (per 10-cm increment) was associated with increased CRC risk (OR = 1.08, 95% CI = 1.02–1.15). In sex-specific analyses, height was associated with CRC risk for women (OR = 1.15, 95% CI = 1.05–1.26), but not men (OR = 0.98, 95% CI = 0.92–1.05). Consistent with these results, carrying greater numbers of (weighted) height-increasing alleles (per 1-unit increase) was associated with higher CRC risk for women and men combined (OR = 1.07, 95% CI = 1.01–1.14) and for women (OR = 1.09, 95% CI = 1.01–1.19). There was weaker evidence of an association for men (OR = 1.05, 95% CI = 0.96–1.15). Conclusion: We provide evidence for a causal association between height and CRC for women. The CRC-height association for men remains unclear and warrants further investigation in other large studies. PMID:25997436

  7. 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...

  8. 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...

  9. Graphene Oxide Derived Carbons (GODC); High-Surface Area NanoPorous Materials for Hydrogen Storage and Carbon Capture

    Science.gov (United States)

    Yildirim, Taner

    2012-02-01

    Even though there has been extensive research on gas adsorption properties of various carbon materials based on activated carbon and nanotubes, there has been little work done on the gas adsorption properties of graphite oxide (GO). In this study [1], we show that one-and-a-half-century-old graphite oxide can be easily turned into a potentially useful gas storage material. In order to create high-surface nanoporous materials from GO, we used two different approaches. In the first approach, we have successfully synthesized graphene-oxide framework materials (GOFs) by interlinking GO layers by diboronic acids. The resulting GOF materials have well defined pore size and BET surface area up to 500 m2/g with twice larger heat of adsorption of H2 and CO2 than those found in other physisorption materials such as MOF5. In the second approach, we synthesized a range of high surface area GO derived carbons (GODC) and studied their applications toward H2, CO2 and CH4 gas storage. The GODCs, with wide range of pore structure, have been prepared by chemical activation with potassium hydroxide (KOH). We obtain largely increased surface areas up to nearly 1900 m^2/g for GODC samples from 10 m^2/g for initial GO. A detailed experimental study of high pressure excess sorption isotherms on GODCs reveal an increase in both CO2 and CH4 storage capacities compared to other high surface area activated carbons. Finally, we compared the gas sorption properties of our GO-based matarials with other systems such as MOFs, ZIFs, and COFs. [4pt] [1] See http://www.ncnr.nist.gov/staff/taner for references and more information.

  10. Urban Heat Island Modeling in Conjunction with Satellite-Derived Surface/Soil Parameters.

    Science.gov (United States)

    Hafner, Jan; Kidder, Stanley Q.

    1999-04-01

    Although it has been studied for over 160 years, the urban heat island (UHI) effect is still not completely understood, yet it is increasingly important. The main purpose of this work is to improve UHI modeling by using AVHRR (Advanced Very High Resolution Radiometer) satellite data to retrieve the surface parameters (albedo, as well as soil thermal and moisture properties). In this study, a hydrostatic three-dimensional mesoscale model was used to perform the numerical modeling. The Carlson technique was applied to retrieve the thermal inertia and moisture availability using the thermal AVHRR channels 4 and 5. The net urban effect was determined as the difference between urban and nonurban simulations, in which urban parameters were replaced by rural parameters.Two winter days were each used for two numerical simulations: a control and an urban-to-rural replacement run. Moisture availability values on the less windy day showed generally a south to north gradient downwind of the city and urban values less than rural values (the urban dry island day). Moisture availability was higher on the windy day, with uniform values in the rural and urban areas (uniform soil moisture day). The only exceptions were variations in the rural hills north of the city and the low rural values under the polluted urban plume downwind of the city.While thermal inertia values showed no urban-rural differences on the uniform soil moisture day, they exhibited larger values over Atlanta than in surrounding rural area on the (less moist) dry island day. Two puzzling facts exist in the data: 1) lack of a north-south thermal inertia gradient on the dry soil day to correspond to its above-mentioned moisture availability gradient and 2) rural thermal inertia values do not change between both days in spite of their large difference in soil moisture. The observed lack of corresponding urban change is expected, as its thermal inertia values depend more on urban building materials than on moisture of

  11. Tailoring ferroelectric interfaces: surface modification of PZT mediated through functionalized thiophene derivates

    Energy Technology Data Exchange (ETDEWEB)

    Milde, Peter; Koehler, Denny; Zerweck, Ulrich; Eng, Lukas M. [Department of Applied Photophysics, TU Dresden (Germany); Haubner, Kinga [Leibniz Institute for Solid State and Materials Research, TU Dresden (Germany); Institute of Macromolecular Chemistry and Textile Chemistry, TU Dresden (Germany); Jaehne, Evelyn [Institute of Macromolecular Chemistry and Textile Chemistry, TU Dresden (Germany)

    2010-07-01

    Organic field effect transistors (OFETs) with a gate ''electrode'' that is made out of a ferroelectric (FE) have become a field of intense research. Non-volatile memory functionality is expected due to the strong and remanent electric field arising from bound surface charges at the FE/molecular interface. In order to achieve excellent electric transport properties, a high degree of intermolecular ordering is inevitable. In our approach, lead zirconate titanate (PZT) is used as material of choice for the design of an ultra-thin ferroelectric gate electrode in a Ferroelectric-OFET. The focus of the present work lays on the growth process of the molecularly thin organic conduction layer, based on {alpha},{omega}-dicyano-{beta},{beta}*-dibutylquaterthiophene (DCNDBQT). Film formation is effectively promoted through specifically designed, bifunctional self-assembling molecules (CNBTPA: 5-cyano-2-(butyl-4-phosphonic acid)-3-butylthiophene) which act as template layer. We report on nc-AFM and KPFM investigation of the template layer's structural and electronic properties.

  12. Diazonium salt derivatives of osmium bipyridine complexes: Electrochemical grafting and characterisation of modified surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Garrett, David J. [MacDiarmid Institute for Advanced Materials and Nanotechnology, Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Jenkins, Peter [School of Chemistry, National University of Ireland, Galway (Ireland); Polson, Matthew I.J. [Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Leech, Donal [School of Chemistry, National University of Ireland, Galway (Ireland); Baronian, Keith H.R. [School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Downard, Alison J., E-mail: alison.downard@canterbury.ac.n [MacDiarmid Institute for Advanced Materials and Nanotechnology, Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch (New Zealand)

    2011-02-01

    Osmium bipyridine complexes were directly grafted to carbon electrodes through electroreduction of the diazonium salts [Os(bpy-ph-N{sub 2}{sup +}){sub 3}](PF{sub 6}){sub 5} (1) and [Os(bpy-ph-N{sub 2}{sup +}){sub 2}Cl{sub 2}](PF{sub 6}){sub 2} (2). Growth of the films was not self-limiting as is usually found for grafting from diazonium salts. It appears that electron hopping through the bipyridine ligands of the immobilised complexes enables film growth to continue at a constant rate during grafting by potential cycling. The surface concentrations of deposited films were measured electrochemically and the film thicknesses were measured by depth-profiling using the atomic force microscope. Films up to 42 nm thick were prepared with no evidence for slowing of film growth. The grafted films exhibited high stability when repetitively cycled through the Os{sup 2+/3+} couple and electron transfer rate constants of 11.4 s{sup -1} and 35.4 s{sup -1} were measured in ACN and PBS, respectively, for the Os{sup 2+/3+} couple of the film grafted from 1.

  13. Molecular self-assembly in substituted alanine derivatives: XRD, Hirshfeld surfaces and DFT studies

    Science.gov (United States)

    Rajalakshmi, Periasamy; Srinivasan, Navaneethakrishnan; Sivaraman, Gandhi; Razak, Ibrahim Abdul; Rosli, Mohd Mustaqim; Krishnakumar, Rajaputi Venkatraman

    2014-06-01

    The molecular assemblage in the crystal structures of three modified chiral amino acids, two of which are isomeric D- and L-pairs boc-L-benzothienylalanine (BLA), boc-D-benzothienylalanine (BDA) and the other boc-D-naphthylalanine (NDA) differing from this pair very slightly in the chemical modification introduced, is accurately described. The aggregation of amino acid molecules is similar in all the crystals and may be described as a twisted double helical ladder in which two complementary long helical chains formed through O-H⋯O hydrogen bonds are interconnected through the characteristic head-to-tail N-H⋯O hydrogen bonds. Thus the molecular aggregation enabled through classical hydrogen bonds may be regarded as a mimic of the characteristic double helical structure of DNA. Also, precise structural information involving these amino acid molecules with lower symmetry exhibiting higher trigonal symmetry in their self-assembly is expected to throw light on the nature and strength of intermolecular interactions and their role in self-assembly of molecular aggregates, which are crucial in developing new or at least supplement existing crystal engineering strategies. Single crystal X-ray analysis and their electronic structures were calculated at the DFT level with a detailed analysis of Hirshfeld surfaces and fingerprint plots facilitating a comparison of intermolecular interactions in building different supramolecular architectures.

  14. Molecular analysis of petroleum derived compounds that adsorb onto gas hydrate surfaces

    International Nuclear Information System (INIS)

    Borgund, Anna E.; Hoiland, Sylvi; Barth, Tanja; Fotland, Per; Askvik, Kjell M.

    2009-01-01

    Field observations have shown that some streams of water, gas and crude oil do not form gas hydrate plugs during petroleum production even when operating within thermodynamic conditions for hydrate formation. Also, when studied under controlled laboratory conditions, some oils are found to form hydrate dispersed systems whereas others form plugs. Oils with low tendency to form hydrate plugs are believed to contain natural hydrate plug inhibiting components (NICs) that adsorb onto the hydrate surface, making them less water-wet and preventing the particles from agglomerating into large hydrate clusters. The molecular structure of the NICs is currently unknown. In this work, hydrate adsorbing components were extracted from crude oils using freon hydrates as an extraction phase. The fractions were found to be enriched in polar material, and more polar material is associated with hydrates generated in biodegraded crude oils than in non-biodegraded oils. Various fractionation schemes and analytical techniques have been applied in the search for molecular characterisation. The average molecular weights were found to be approximately 500 g/mole. GC-MS chromatograms show a large UCM (Unresolved Complex Mixture). Thus, GC-MS has a limited potential for identification of compounds. A commercial biosurfactant was used as a model compound in the search for similar structures in the extracts. The results from analysis of the hydrate adsorbing components suggest that the type and structure are more important for hydrate morphology than the amount of material adsorbed.

  15. Specular and diffuse object extraction from a LiDAR derived Digital Surface Model (DSM)

    International Nuclear Information System (INIS)

    Saraf, N M; Hamid, J R A; Kamaruddin, M H

    2014-01-01

    This paper intents to investigate the indifferent behaviour quantitatively of target objects of interest due to specular and diffuse reflectivity based on generated LiDAR DSM of the study site in Ampang, Kuala Lumpur. The LiDAR data to be used was initially checked for its reliability and accuracy. The point cloud LiDAR data was converted to raster to allow grid analysis of the next process of generating the DSM and DTM. Filtering and masking were made removing the features of interest (i.e. building and tree) and other unwanted above surface features. A normalised DSM and object segmentation approach were conducted on the trees and buildings separately. Error assessment and findings attained were highlighted and documented. The result of LiDAR verification certified that the data is reliable and useable. The RMSE obtained is within the tolerance value of horizontal and vertical accuracy (x, y, z) i.e. 0.159 m, 0.211 m 0.091 m respectively. Building extraction inclusive of roof top based on slope and contour analysis undertaken indicate the capability of the approach while single tree extraction through aspect analysis appears to preserve the accuracy of the extraction accordingly. The paper has evaluated the suitable methods of extracting non-ground features and the effective segmentation of the LiDAR data

  16. Analysis of External Surface Irregularities on Fukushima-Derived Fallout Particles

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Peter George, E-mail: peter.martin@bristol.ac.uk [Interface Analysis Centre, School of Physics, University of Bristol, HH Wills Physics Laboratory, Bristol (United Kingdom); Satou, Yukihiko [Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency, Tomioka (Japan); Griffiths, Ian [Interface Analysis Centre, School of Physics, University of Bristol, HH Wills Physics Laboratory, Bristol (United Kingdom); Richards, David [School of Geographical Sciences, University of Bristol, Bristol (United Kingdom); Scott, Thomas [Interface Analysis Centre, School of Physics, University of Bristol, HH Wills Physics Laboratory, Bristol (United Kingdom)

    2017-09-22

    Three large high radioactivity particulate fragments, each several 100 μm in diameter, have been recovered from the region immediately surrounding the Fukushima Daiichi Nuclear Power Plant. Through the application of high-resolution electron and ion-beam methods, this work has sought to investigate the structure and composition of this fibrous surface morphology. By evaluating this, a potential material source can be determined, alongside important information relating to the conditions/events at the time of the reactor explosions and catastrophic release of radioactive materials. The results of this study show that the fibrous features associated with these large radiocesium-containing particles share a common elemental composition. With respect to the surrounding particle, the fibers are enriched in Si, Cl, and Fe, while depleted in both Zn and Al. Based on composition, these fibers are ascribed to thermal insulating material used within the plant, which was sufficiently heated during the loss of coolant incident at the plant to be incorporated into the molten ejecta material that rapidly solidified upon quenching in air. Elemental analysis of these fibers does not reveal any evidence of leaching or the presence of actinide materials.

  17. The derivation of sub-canopy surface terrain models of coastal forests using synthetic aperture radar

    Science.gov (United States)

    Imhoff, M. L.; Gesch, D. B.

    1988-01-01

    Radar data acquired by the Shuttle Imaging Radar-B mission covering a portion of the Mouths of the Ganges forests were used to create a terrain model for use in determining tidal flow and eventual nutrient transport from the forest to the marine habitat. Results show that good digital topographic terrain models of wet coastal forests can be generated using multiple sets of L-band SAR and ancillary tide elevation data. The dominance of the interaction phenomenon in the radar backscatter of flooded forests can be used to create sub-canopy inundation maps which when merged with tide surface data can be used to generate reasonable topographic models. Ideally models could be improved by using multiple sets of data at a constant incidence angle over the total tide range. The optimal angle for the SAR depends upon the characteristics of the forest. The range of 46 to 57 deg seems applicable to the 12.5 m tall closed canopy in this example. Such models can be an extremely valuable tool for studying and mapping the mangal ecosystem.

  18. Sodar detection of mixing height in flat and mountainous terrain

    Energy Technology Data Exchange (ETDEWEB)

    Hennemuth, B [Consulting Meteorologist, Hamburg (Germany); Kirtzel, H-Juergen [METEK GmbH, Elmshorn (Germany)], E-mail: barbara.hennemuth@zmaw.de

    2008-05-01

    The atmospheric boundary layer plays an important role in air pollution and dispersion problems because the transport processes are managed within this layer and its top limits the vertical exchange of pollutants. A method for the derivation of the mixing height from measurements of sodar, RASS and sonic anemometer-thermometer is presented for flat terrain. It does not only use vertical profiles of measured parameters but also bulk information like histograms and time evolution. Results from a two-years period are verified by radiosonde-derived mixing height values and show the potential of the combination of the three systems to monitor the mixing height. Difficulties arise at locations in mountainous terrain where thermal wind regimes dominate which are highly non-local. An additional problem is a strong local heat source at an industrial site where even the definition of the mixing height is unclear.

  19. Hydrogen bonds induced supramolecular self-assembly of azobenzene derivatives on the highly oriented pyrolytic graphite surface

    Science.gov (United States)

    Miao, Xinrui; Cheng, Zhiyu; Ren, Biye; Deng, Wenli

    2012-08-01

    The self-assembly of azobenzene derivatives (CnAzCOOH) with various lengths of peripheral alkyl chains (with carbon number of n = 8, 10, 12, 14, 16) were observed by scanning tunneling microscopy on highly oriented pyrolytic graphite (HOPG) surface. The effect of van der Waals interactions and the intermolecular hydrogen bonding on the two-dimensional self-assembly was systematically studied. No alkyl-chain length effect was observed according to the STM images. All kinds of CnAzCOOH adopting the same pattern self-assembled on the HOPG surface, suggesting the formation of the two-dimensional structures was dominated by the hydrogen bonding of the functional groups. It could be found that two CnAzCOOH molecules formed a hydrogen-bonded dimer with “head-to-head” fashion as expected; however, the dimers organized themselves in the form of relative complex lamellae. Three dimers as a group arranged side by side and formed a well-defined stripe with periodic dislocations due to the registry mechanism of the alkyl chain with the underlying HOPG surface. The hydrogen bonds between the adjacent dimers in one lamella were formed and dominated the self-assembled pattern.

  20. Flood Damage Analysis: First Floor Elevation Uncertainty Resulting from LiDAR-Derived Digital Surface Models

    Directory of Open Access Journals (Sweden)

    José María Bodoque

    2016-07-01

    Full Text Available The use of high resolution ground-based light detection and ranging (LiDAR datasets provides spatial density and vertical precision for obtaining highly accurate Digital Surface Models (DSMs. As a result, the reliability of flood damage analysis has improved significantly, owing to the increased accuracy of hydrodynamic models. In addition, considerable error reduction has been achieved in the estimation of first floor elevation, which is a critical parameter for determining structural and content damages in buildings. However, as with any discrete measurement technique, LiDAR data contain object space ambiguities, especially in urban areas where the presence of buildings and the floodplain gives rise to a highly complex landscape that is largely corrected by using ancillary information based on the addition of breaklines to a triangulated irregular network (TIN. The present study provides a methodological approach for assessing uncertainty regarding first floor elevation. This is based on: (i generation an urban TIN from LiDAR data with a density of 0.5 points·m−2, complemented with the river bathymetry obtained from a field survey with a density of 0.3 points·m−2. The TIN was subsequently improved by adding breaklines and was finally transformed to a raster with a spatial resolution of 2 m; (ii implementation of a two-dimensional (2D hydrodynamic model based on the 500-year flood return period. The high resolution DSM obtained in the previous step, facilitated addressing the modelling, since it represented suitable urban features influencing hydraulics (e.g., streets and buildings; and (iii determination of first floor elevation uncertainty within the 500-year flood zone by performing Monte Carlo simulations based on geostatistics and 1997 control elevation points in order to assess error. Deviations in first floor elevation (average: 0.56 m and standard deviation: 0.33 m show that this parameter has to be neatly characterized in order

  1. Local digital control of power electronic converters in a dc microgrid based on a-priori derivation of switching surfaces

    Science.gov (United States)

    Banerjee, Bibaswan

    In power electronic basedmicrogrids, the computational requirements needed to implement an optimized online control strategy can be prohibitive. The work presented in this dissertation proposes a generalized method of derivation of geometric manifolds in a dc microgrid that is based on the a-priori computation of the optimal reactions and trajectories for classes of events in a dc microgrid. The proposed states are the stored energies in all the energy storage elements of the dc microgrid and power flowing into them. It is anticipated that calculating a large enough set of dissimilar transient scenarios will also span many scenarios not specifically used to develop the surface. These geometric manifolds will then be used as reference surfaces in any type of controller, such as a sliding mode hysteretic controller. The presence of switched power converters in microgrids involve different control actions for different system events. The control of the switch states of the converters is essential for steady state and transient operations. A digital memory look-up based controller that uses a hysteretic sliding mode control strategy is an effective technique to generate the proper switch states for the converters. An example dcmicrogrid with three dc-dc boost converters and resistive loads is considered for this work. The geometric manifolds are successfully generated for transient events, such as step changes in the loads and the sources. The surfaces corresponding to a specific case of step change in the loads are then used as reference surfaces in an EEPROM for experimentally validating the control strategy. The required switch states corresponding to this specific transient scenario are programmed in the EEPROM as a memory table. This controls the switching of the dc-dc boost converters and drives the system states to the reference manifold. In this work, it is shown that this strategy effectively controls the system for a transient condition such as step changes

  2. CryoSat-2 SAR and SARin Inland Water Heights from the CRUCIAL project

    Science.gov (United States)

    Benveniste, J.; Restano, M.; Ambrózio, A.; Moore, P.; Birkinshaw, S.

    2017-12-01

    CRUCIAL was an ESA/STSE funded project investigating innovative land and inland water applications from CryoSat-2 with a forward-look component to the Sentinel-3 and Jason-CS/Sentinel-6 missions. The high along-track sampling of CryoSat-2 in its SAR and SARin modes offers the opportunity to recover high frequency signals over inland waters. A methodology was developed to process the FBR L1A Doppler beams to form a waveform product using ground cell gridding, beam steering and beam stacking. Inland water heights from CryoSat-2 are derived by using a set of empirical retrackers formulated for inland water applications. Results of the processing strategy include a comparison of waveforms and heights from the burst echoes (80 m along-track) and from multi-look waveforms (320 m along-track). SAR and SARin FBR data are available for the Amazon, Brahmaputra and Mekong for 2011-2015. FBR SAR results are compared against stage data from the nearest gauge. Heights from Tonlé Sap are also compared against Jason-2 data from the United States Department of Agriculture. A strategy to select the number of multi-looks over rivers was designed based on the rms of heights across Tonlé Sap. Comparisons include results from the empirical retrackers and from waveforms and heights obtained via ESA's Grid Processing on Demand (G-POD/SARvatore) using the SAMOSA2 retracker. Results of FBR SARin processing for the Amazon and Brahmaputra are presented including comparison of heights from the two antennae, extraction of slope of the ground surface and validation against ground data where appropriate.

  3. Mono-Fluorinated Alkyne-Derived SAMs on Oxide-Free Si(III) Surfaces: Preparation, Characterization and Tuning of the Si Workfunction

    NARCIS (Netherlands)

    Pujari, S.P.; Andel, van E.; Yaffe, O.; Cahen, D.; Weidner, T.; Rijn, van C.J.M.; Zuilhof, H.

    2013-01-01

    Organic monolayers derived from ¿-fluoro-1-alkynes of varying carbon chain lengths (C(10)-C(18)) were prepared on Si(111) surfaces, resulting in changes of the physical and electronic properties of the surface. Analysis of the monolayers using XPS, Infrared Reflection Absorption Spectroscopy,

  4. Tropical cyclone cloud‐top height and vertical temperature structure detection using GPS radio occultation measurements

    DEFF Research Database (Denmark)

    Biondi, Riccardo; Ho, Shu‐Peng; Randel, William

    2013-01-01

    The accurate determination of tropical cyclone (TC) cloud-top height and its vertical thermal structure using the GPS radio occultation (RO) technique is demonstrated in this study. Cloud-top heights are determined by using the bending angle anomaly and the temperature anomaly profiles during......-derived inversion heights and those from radiosonde temperature profiles is approximately 500 m. Results show that, while cloud-top height detected from nadir-viewing satellites can be easily biased by a few kilometers, the biases of RO-derived cloud-top height are within ~500 m....

  5. Effects and Interactions of Medium Components on Laccase from a Marine-Derived Fungus Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Chandralata Raghukumar

    2009-11-01

    Full Text Available The effects of various synthetic medium components and their interactions with each other ultimately impact laccase production in fungi. This was studied using a laccasehyper-producing marine-derived basidiomycete, Cerrena unicolor MTCC 5159. Inducible laccases were produced in the idiophase only after addition of an inducer such as CuSO4. Concentration of carbon and nitrogen acted antagonistically with respect to laccase production. A combination of low nitrogen and high carbon concentration favored both biomass and laccase production. The most favorable combination resulted in 917 U L-1 of laccase. After sufficient growth had occurred, addition of a surfactant such as Tween 80 positively impacted biomass and increased the laccase activity to around 1,300 U L-1. Increasing the surface to volume ratio of the culture vessel further increased its activity to almost 2,000 U L-1.

  6. 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

  7. 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

  8. 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

  9. Segmentation process significantly influences the accuracy of 3D surface models derived from cone beam computed tomography

    International Nuclear Information System (INIS)

    Fourie, Zacharias; Damstra, Janalt; Schepers, Rutger H.; Gerrits, Peter O.; Ren Yijin

    2012-01-01

    Aims: To assess the accuracy of surface models derived from 3D cone beam computed tomography (CBCT) with two different segmentation protocols. Materials and methods: Seven fresh-frozen cadaver heads were used. There was no conflict of interests in this study. CBCT scans were made of the heads and 3D surface models were created of the mandible using two different segmentation protocols. The one series of 3D models was segmented by a commercial software company, while the other series was done by an experienced 3D clinician. The heads were then macerated following a standard process. A high resolution laser surface scanner was used to make a 3D model of the macerated mandibles, which acted as the reference 3D model or “gold standard”. The 3D models generated from the two rendering protocols were compared with the “gold standard” using a point-based rigid registration algorithm to superimpose the three 3D models. The linear difference at 25 anatomic and cephalometric landmarks between the laser surface scan and the 3D models generate from the two rendering protocols was measured repeatedly in two sessions with one week interval. Results: The agreement between the repeated measurement was excellent (ICC = 0.923–1.000). The mean deviation from the gold standard by the 3D models generated from the CS group was 0.330 mm ± 0.427, while the mean deviation from the Clinician's rendering was 0.763 mm ± 0.392. The surface models segmented by both CS and DS protocols tend to be larger than those of the reference models. In the DS group, the biggest mean differences with the LSS models were found at the points ConLatR (CI: 0.83–1.23), ConMedR (CI: −3.16 to 2.25), CoLatL (CI: −0.68 to 2.23), Spine (CI: 1.19–2.28), ConAntL (CI: 0.84–1.69), ConSupR (CI: −1.12 to 1.47) and RetMolR (CI: 0.84–1.80). Conclusion: The Commercially segmented models resembled the reality more closely than the Doctor's segmented models. If 3D models are needed for surgical drilling

  10. Re-examining data-intensive surface water models with high-resolution topography derived from unmanned aerial system photogrammetry

    Science.gov (United States)

    Pai, H.; Tyler, S.

    2017-12-01

    Small, unmanned aerial systems (sUAS) are quickly becoming a cost-effective and easily deployable tool for high spatial resolution environmental sensing. Land surface studies from sUAS imagery have largely focused on accurate topographic mapping, quantifying geomorphologic changes, and classification/identification of vegetation, sediment, and water quality tracers. In this work, we explore a further application of sUAS-derived topographic mapping to a two-dimensional (2-d), depth-averaged river hydraulic model (Flow and Sediment Transport with Morphological Evolution of Channels, FaSTMECH) along a short, meandering reach of East River, Colorado. On August 8, 2016, we flew a sUAS as part of the Center for Transformative Environmental Monitoring Programs with a consumer-grade visible camera and created a digital elevation map ( 1.5 cm resolution; 5 cm accuracy; 500 m long river corridor) with Agisoft Photoscan software. With the elevation map, we created a longitudinal water surface elevation (WSE) profile by manually delineating the bank-water interface and river bathymetry by applying refraction corrections for more accurate water depth estimates, an area of ongoing research for shallow and clear river systems. We tested both uncorrected and refraction-corrected bathymetries with the steady-state, 2-d model, applying sensitivities for dissipation parameters (bed roughness and eddy characteristics). Model performance was judged from the WSE data and measured stream velocities. While the models converged, performance and insights from model output could be improved with better bed roughness characterization and additional water depth cross-validation for refraction corrections. Overall, this work shows the applicability of sUAS-derived products to a multidimensional river model, where bathymetric data of high resolution and accuracy are key model input requirements.

  11. Direct detection of nano-scale extracellular vesicles derived from inflammation-triggered endothelial cells using surface plasmon resonance.

    Science.gov (United States)

    Hosseinkhani, Baharak; van den Akker, Nynke; D'Haen, Jan; Gagliardi, Mick; Struys, Tom; Lambrichts, Ivo; Waltenberger, Johannes; Nelissen, Inge; Hooyberghs, Jef; Molin, Daniel G M; Michiels, Luc

    2017-07-01

    A major conceptual breakthrough in cell signaling has been the finding of EV as new biomarker shuttles in body fluids. Now, one of the major challenges in using these nanometer-sized biological entities as diagnostic marker is the development of translational methodologies to profile them. SPR offers a promising label-free and real time platform with a high potential for biomarker detection. Therefore, we aimed to develop a uniform SPR methodology to detect specific surface markers on EV derived from patient with CHD. EVs having an approximate size range between 30 and 100 nm (~48.5%) and 100-300 nm (~51.5%) were successfully isolated. The biomarker profile of EV was verified using immunogold labeling, ELISA and SPR. Using SPR, we demonstrated an increased binding of EV derived from patients with CHD to anti-ICAM-1 antibodies as compared to EV from healthy donors. Our current findings open up novel opportunities for in-depth and label-free investigation of EV. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  12. Porous Proton- and Chloride-Ion Conducting Layers Based on Ethanolamine Derivatives of PVC on the Surfaces of Fabrics

    Science.gov (United States)

    Tsivadze, A. Yu.; Fridman, A. Ya.; Morozova, E. M.; Sokolova, N. P.; Voloshchuk, A. M.; Bardyshev, I. I.; Gorbunov, A. M.; Novikov, A. K.; Polyakova, I. Ya.; Titova, B. N.; Yavich, A. A.

    2018-02-01

    Materials are produced with porous layers based on ethanolamine derivatives of PVC or compounds of active carbon with hydroxyethylcyclam derivatives of PVC with aqua complexes of chloride hydrogen cross-linked with the surface of cellulose or asbestos fabric. Their capacity for sorption with respect to hexane and benzene in the saturated vapor and liquid phases is determined. The dependences of current on voltage in a circuit are determined for bridges composed of these materials in air, and in the vapor and liquid phases of benzene and hexane between 3 M HCl solutions and 3 M HCl solutions containing 3 M CaCl2. It is established that only H+ ions migrate along the bridges between the HCl solutions, and H+ and Cl- ions were the only species that moved along the bridges between the HCl solutions containing CaCl2. The voltages at which the movement of ions starts are determined, and constants characterizing the conductivity of the layers are found. It is shown that these parameters depend on the structure of a layer, the nature of the fabric, and the medium surrounding a bridge.

  13. Role of dbnd NOH intermolecular interactions in oxime derivatives via Crystal structure, Hirshfeld surface, PIXELC and DFT calculations

    Science.gov (United States)

    Purushothaman, Gayathri; Thiruvenkatam, Vijay

    2017-11-01

    Oximes are building block of organic synthesis and they have wide range applications in laboratories, industries, and pharmaceutical as antidotes. Herein we report the crystal structures of oxime derivative Beta-p-Dimethylaminodeoxybenzionoxime (I) and o-Chloro-p-dimethylaminodeoxybenzion (II) the precursor molecule of o-Chloro-p-dimethylaminodeoxybenzionoxime and their intermolecular interactions studies through Hirshfeld surface & 2D-fingerprint plot analysis along with PIXELC and DFT calculations. The packing arrangements in I and II are driven by Osbnd H⋯N and Osbnd H⋯C interactions respectively. The Osbnd H⋯N hydrogen bonding in I facilitates the formation of the dimer with the motif of R (22(6)), whereas in II absence of oxime moiety (dbnd NOH) restricts the dimer formation. The 2D-fingerprint plot shows the close contacts for the intermolecular interactions in I & II. The PIXELC calculation of II suggests Osbnd H⋯C contributes for intermolecular interaction that stabilizes the crystal packing with the total energy value of 60.4 kcal/mol. The DFT calculation using B3LYP with 6-311G (d, p) functional set for both the derivatives shows a small deviation in the benzene ring (I) and chlorobenzene ring (II) with the RMSD value of 0.5095 Å and 0.8472 Å respectively.

  14. Structural characterizations, Hirshfeld surface analyses, and third-order nonlinear optical properties of two novel chalcone derivatives

    Science.gov (United States)

    Maidur, Shivaraj R.; Jahagirdar, Jitendra R.; Patil, Parutagouda Shankaragouda; Chia, Tze Shyang; Quah, Ching Kheng

    2018-01-01

    We report synthesis, characterizations, structure-property relationships, and third-order nonlinear optical studies for two new chalcone derivatives, (2E)-1-(anthracen-9-yl)-3-(4-bromophenyl)prop-2-en-1-one (Br-ANC) and (2E)-1-(anthracen-9-yl)-3-(4-chlorophenyl)prop-2-en-1-one (Cl-ANC). These derivatives were crystallized in the centrosymmetric monoclinic P21/c crystal structure. The intermolecular interactions of both the crystals were visualized by Hirshfeld surface analyses (HSA). The crystals are thermally stable up to their melting points (180.82 and 191.16 °C for Cl-ANC and Br-ANC, respectively). The geometry optimizations, FT-IR spectra, 1H and 13C NMR spectra, electronic absorption spectra, electronic transitions, and HOMO-LUMO energy gaps were studied by Density Functional Theory (DFT) at B3LYP/6-311+G(d, p) level. The theoretical results provide excellent agreement with experimental findings. The electric dipole moments, static polarizabilities, molecular electrostatic potentials (MEP) and global chemical reactivity descriptors (GCRD) were also theoretically computed. The materials exhibited good nonlinear absorption (NLA), nonlinear refraction (NLR) and optical limiting (OL) behavior under diode-pumped solid-state (DPSS) continuous wave (CW) laser excitation (532 nm and 200 mW). The NLO parameters such as NLA coefficient (β∼10-5 cmW-1), NLR index (n2∼10-10 cm2 W-1) and third-order NLO susceptibilities (χ(3) ∼10-7 esu) were measured. Further, we estimated one-photon and two-photon figures of merit, which satisfy the demands (W > 1 and T < 1) for all-optical switching. Thus, the present chalcone derivatives with anthracene moiety are potential materials for OL and optical switching applications.

  15. Assessment of the accuracy of snow surface direct beam spectral albedo under a variety of overcast skies derived by a reciprocal approach through radiative transfer simulation.

    Science.gov (United States)

    Li, Shusun; Zhou, Xiaobing

    2003-09-20

    With radiative transfer simulations it is suggested that stable estimates of the highly anisotropic direct beam spectral albedo of snow surface can be derived reciprocally under a variety of overcast skies. An accuracy of +/- 0.008 is achieved over a solar zenith angle range of theta0 snow surface albedo for the polar regions where direct measurement of clear-sky surface albedo is limited to large theta0's only. The enhancement will assist in the validation of snow surface albedo models and improve the representation of polar surface albedo in global circulation models.

  16. Height and Breast Cancer Risk

    DEFF Research Database (Denmark)

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

    2015-01-01

    -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......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...

  17. Tree Height Calculator: An Android App for Estimating Tree Height

    Science.gov (United States)

    Burca, V. S.; Htet, N. M.; Huang, X.; de Lanerolle, T. R.; Morelli, R.; Gourley, J. R.

    2011-12-01

    Conventionally, measuring tree height requires a collection of different tools - clinometer, transit, pencil, paper, laptop computer. Results are recorded manually and entered into a spreadsheet or database for future calculation and analysis. Tree Height Calculator is a mobile Android app the integrates the various steps in this process thereby improving the accuracy and dramatically reducing the time required to go from taking measurements to analyzing data. Given the user's height and the distance from the base of the tree (which can be downloaded into the app from a server), the app uses the phone's orientation sensor to calculate the angle of elevation. A simple trigonometric formula is then used to calculate and record the tree's height in the phone's database. When the phone has a WiFi connection, the data are transmitted to a server, from where they can be downloaded directly into a spreadsheet. The application was first tested in an Environmental Science laboratory at Trinity College. On the first trial, 103 data samples were collected, stored, and uploaded to the online database with only couple of dropped data points. On the second trial, 98 data samples were gathered with no loss of data. The app combined the individual measurements taken by the students in the lab, reducing the time required to produce a graph of the class's results from days to hours.

  18. Modelling dengue fever risk in the State of Yucatan, Mexico using regional-scale satellite-derived sea surface temperature.

    Science.gov (United States)

    Laureano-Rosario, Abdiel E; Garcia-Rejon, Julian E; Gomez-Carro, Salvador; Farfan-Ale, Jose A; Muller-Karger, Frank E

    2017-08-01

    Accurately predicting vector-borne diseases, such as dengue fever, is essential for communities worldwide. Changes in environmental parameters such as precipitation, air temperature, and humidity are known to influence dengue fever dynamics. Furthermore, previous studies have shown how oceanographic variables, such as El Niño Southern Oscillation (ENSO)-related sea surface temperature from the Pacific Ocean, influences dengue fever in the Americas. However, literature is lacking on the use of regional-scale satellite-derived sea surface temperature (SST) to assess its relationship with dengue fever in coastal areas. Data on confirmed dengue cases, demographics, precipitation, and air temperature were collected. Incidence of weekly dengue cases was examined. Stepwise multiple regression analyses (AIC model selection) were used to assess which environmental variables best explained increased dengue incidence rates. SST, minimum air temperature, precipitation, and humidity substantially explained 42% of the observed variation (r 2 =0.42). Infectious diseases are characterized by the influence of past cases on current cases and results show that previous dengue cases alone explained 89% of the variation. Ordinary least-squares analyses showed a positive trend of 0.20±0.03°C in SST from 2006 to 2015. An important element of this study is to help develop strategic recommendations for public health officials in Mexico by providing a simple early warning capability for dengue incidence. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Optimal inflatable space towers of high height

    Science.gov (United States)

    Bolonkin, A.

    Author suggested, developed theory, and computed some projects of an optimal inflatable space tower of the heights some hundreds km. These towers can be used for tourism, scientist observation of space, Earth surface, Earth weather, Earth top atmosphere, and for radio, TV, communication transmissions. These towers can be used for launching of the space ships and Earth s atellites. The computed projects not expensive, do not request rockets. They need only in thin strong films composed from the artificial fibers and fabricated by a current industry. Towers can be built by a current technology. Towers can be explored (for tourism, communication, etc.) in a time of the construction process and give a profit, self- financing for further constriction. They can permanent increase their height. The tower design does not request a work at the high altitudes. All construction works will be making at the Earth surface. Author suggests the transport system for this tower of a high capability, which does not request a power energy issue. The small engine (only for a friction compensation) is located at the Earth surface. The tower is separated on sections and has a special protection of a case of a damage. It is considered also the problems of security, control, repair, etc. of the suggested towers. The author has also solved additional problems, which appear in these projects and which can look as difficult for the given proposal and current technology. The author is prepared to discuss the problems with serious organizations, which want to research and develop these projects.

  20. Comparison of Surface Flow Features from Lidar-Derived Digital Elevation Models with Historical Elevation and Hydrography Data for Minnehaha County, South Dakota

    Science.gov (United States)

    Poppenga, Sandra K.; Worstell, Bruce B.; Stoker, Jason M.; Greenlee, Susan K.

    2009-01-01

    The U.S. Geological Survey (USGS) has taken the lead in the creation of a valuable remote sensing product by incorporating digital elevation models (DEMs) derived from Light Detection and Ranging (lidar) into the National Elevation Dataset (NED), the elevation layer of 'The National Map'. High-resolution lidar-derived DEMs provide the accuracy needed to systematically quantify and fully integrate surface flow including flow direction, flow accumulation, sinks, slope, and a dense drainage network. In 2008, 1-meter resolution lidar data were acquired in Minnehaha County, South Dakota. The acquisition was a collaborative effort between Minnehaha County, the city of Sioux Falls, and the USGS Earth Resources Observation and Science (EROS) Center. With the newly acquired lidar data, USGS scientists generated high-resolution DEMs and surface flow features. This report compares lidar-derived surface flow features in Minnehaha County to 30- and 10-meter elevation data previously incorporated in the NED and ancillary hydrography datasets. Surface flow features generated from lidar-derived DEMs are consistently integrated with elevation and are important in understanding surface-water movement to better detect surface-water runoff, flood inundation, and erosion. Many topographic and hydrologic applications will benefit from the increased availability of accurate, high-quality, and high-resolution surface-water data. The remotely sensed data provide topographic information and data integration capabilities needed for meeting current and future human and environmental needs.

  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. A Satellite-Based Surface Radiation Climatology Derived by Combining Climate Data Records and Near-Real-Time Data

    Directory of Open Access Journals (Sweden)

    Bodo Ahrens

    2013-09-01

    Full Text Available This study presents a method for adjusting long-term climate data records (CDRs for the integrated use with near-real-time data using the example of surface incoming solar irradiance (SIS. Recently, a 23-year long (1983–2005 continuous SIS CDR has been generated based on the visible channel (0.45–1 μm of the MVIRI radiometers onboard the geostationary Meteosat First Generation Platform. The CDR is available from the EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF. Here, it is assessed whether a homogeneous extension of the SIS CDR to the present is possible with operationally generated surface radiation data provided by CM SAF using the SEVIRI and GERB instruments onboard the Meteosat Second Generation satellites. Three extended CM SAF SIS CDR versions consisting of MVIRI-derived SIS (1983–2005 and three different SIS products derived from the SEVIRI and GERB instruments onboard the MSG satellites (2006 onwards were tested. A procedure to detect shift inhomogeneities in the extended data record (1983–present was applied that combines the Standard Normal Homogeneity Test (SNHT and a penalized maximal T-test with visual inspection. Shift detection was done by comparing the SIS time series with the ground stations mean, in accordance with statistical significance. Several stations of the Baseline Surface Radiation Network (BSRN and about 50 stations of the Global Energy Balance Archive (GEBA over Europe were used as the ground-based reference. The analysis indicates several breaks in the data record between 1987 and 1994 probably due to artefacts in the raw data and instrument failures. After 2005 the MVIRI radiometer was replaced by the narrow-band SEVIRI and the broadband GERB radiometers and a new retrieval algorithm was applied. This induces significant challenges for the homogenisation across the satellite generations. Homogenisation is performed by applying a mean-shift correction depending on the shift size of

  3. Regulating Immunogenicity and Tolerogenicity of Bone Marrow-Derived Dendritic Cells through Modulation of Cell Surface Glycosylation by Dexamethasone Treatment

    Directory of Open Access Journals (Sweden)

    Kevin Lynch

    2017-10-01

    Full Text Available Dendritic cellular therapies and dendritic cell vaccines show promise for the treatment of autoimmune diseases, the prolongation of graft survival in transplantation, and in educating the immune system to fight cancers. Cell surface glycosylation plays a crucial role in the cell–cell interaction, uptake of antigens, migration, and homing of DCs. Glycosylation is known to change with environment and the functional state of DCs. Tolerogenic DCs (tDCs are commonly generated using corticosteroids including dexamethasone, however, to date, little is known on how corticosteroid treatment alters glycosylation and what functional consequences this may have. Here, we present a comprehensive profile of rat bone marrow-derived dendritic cells, examining their cell surface glycosylation profile before and after Dexa treatment as resolved by both lectin microarrays and lectin-coupled flow cytometry. We further examine the functional consequences of altering cell surface glycosylation on immunogenicity and tolerogenicity of DCs. Dexa treatment of rat DCs leads to profoundly reduced expression of markers of immunogenicity (MHC I/II, CD80, CD86 and pro-inflammatory molecules (IL-6, IL-12p40, inducible nitric oxide synthase indicating a tolerogenic phenotype. Moreover, by comprehensive lectin microarray profiling and flow cytometry analysis, we show that sialic acid (Sia is significantly upregulated on tDCs after Dexa treatment, and that this may play a vital role in the therapeutic attributes of these cells. Interestingly, removal of Sia by neuraminidase treatment increases the immunogenicity of immature DCs and also leads to increased expression of pro-inflammatory cytokines while tDCs are moderately protected from this increase in immunogenicity. These findings may have important implications in strategies aimed at increasing tolerogenicity where it is advantageous to reduce immune activation over prolonged periods. These findings are also relevant in

  4. Concave pit-containing scaffold surfaces improve stem cell-derived osteoblast performance and lead to significant bone tissue formation.

    Directory of Open Access Journals (Sweden)

    Antonio Graziano

    2007-06-01

    Full Text Available Scaffold surface features are thought to be important regulators of stem cell performance and endurance in tissue engineering applications, but details about these fundamental aspects of stem cell biology remain largely unclear.In the present study, smooth clinical-grade lactide-coglyolic acid 85:15 (PLGA scaffolds were carved as membranes and treated with NMP (N-metil-pyrrolidone to create controlled subtractive pits or microcavities. Scanning electron and confocal microscopy revealed that the NMP-treated membranes contained: (i large microcavities of 80-120 microm in diameter and 40-100 microm in depth, which we termed primary; and (ii smaller microcavities of 10-20 microm in diameter and 3-10 microm in depth located within the primary cavities, which we termed secondary. We asked whether a microcavity-rich scaffold had distinct bone-forming capabilities compared to a smooth one. To do so, mesenchymal stem cells derived from human dental pulp were seeded onto the two types of scaffold and monitored over time for cytoarchitectural characteristics, differentiation status and production of important factors, including bone morphogenetic protein-2 (BMP-2 and vascular endothelial growth factor (VEGF. We found that the microcavity-rich scaffold enhanced cell adhesion: the cells created intimate contact with secondary microcavities and were polarized. These cytological responses were not seen with the smooth-surface scaffold. Moreover, cells on the microcavity-rich scaffold released larger amounts of BMP-2 and VEGF into the culture medium and expressed higher alkaline phosphatase activity. When this type of scaffold was transplanted into rats, superior bone formation was elicited compared to cells seeded on the smooth scaffold.In conclusion, surface microcavities appear to support a more vigorous osteogenic response of stem cells and should be used in the design of therapeutic substrates to improve bone repair and bioengineering applications in the

  5. 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.

  6. Modeling vegetation heights from high resolution stereo aerial photography: an application for broad-scale rangeland monitoring

    Science.gov (United States)

    Gillan, Jeffrey K.; Karl, Jason W.; Duniway, Michael; Elaksher, Ahmed

    2014-01-01

    Vertical vegetation structure in rangeland ecosystems can be a valuable indicator for assessing rangeland health and monitoring riparian areas, post-fire recovery, available forage for livestock, and wildlife habitat. Federal land management agencies are directed to monitor and manage rangelands at landscapes scales, but traditional field methods for measuring vegetation heights are often too costly and time consuming to apply at these broad scales. Most emerging remote sensing techniques capable of measuring surface and vegetation height (e.g., LiDAR or synthetic aperture radar) are often too expensive, and require specialized sensors. An alternative remote sensing approach that is potentially more practical for managers is to measure vegetation heights from digital stereo aerial photographs. As aerial photography is already commonly used for rangeland monitoring, acquiring it in stereo enables three-dimensional modeling and estimation of vegetation height. The purpose of this study was to test the feasibility and accuracy of estimating shrub heights from high-resolution (HR, 3-cm ground sampling distance) digital stereo-pair aerial images. Overlapping HR imagery was taken in March 2009 near Lake Mead, Nevada and 5-cm resolution digital surface models (DSMs) were created by photogrammetric methods (aerial triangulation, digital image matching) for twenty-six test plots. We compared the heights of individual shrubs and plot averages derived from the DSMs to field measurements. We found strong positive correlations between field and image measurements for several metrics. Individual shrub heights tended to be underestimated in the imagery, however, accuracy was higher for dense, compact shrubs compared with shrubs with thin branches. Plot averages of shrub height from DSMs were also strongly correlated to field measurements but consistently underestimated. Grasses and forbs were generally too small to be detected with the resolution of the DSMs. Estimates of

  7. Modeling vegetation heights from high resolution stereo aerial photography: an application for broad-scale rangeland monitoring.

    Science.gov (United States)

    Gillan, Jeffrey K; Karl, Jason W; Duniway, Michael; Elaksher, Ahmed

    2014-11-01

    Vertical vegetation structure in rangeland ecosystems can be a valuable indicator for assessing rangeland health and monitoring riparian areas, post-fire recovery, available forage for livestock, and wildlife habitat. Federal land management agencies are directed to monitor and manage rangelands at landscapes scales, but traditional field methods for measuring vegetation heights are often too costly and time consuming to apply at these broad scales. Most emerging remote sensing techniques capable of measuring surface and vegetation height (e.g., LiDAR or synthetic aperture radar) are often too expensive, and require specialized sensors. An alternative remote sensing approach that is potentially more practical for managers is to measure vegetation heights from digital stereo aerial photographs. As aerial photography is already commonly used for rangeland monitoring, acquiring it in stereo enables three-dimensional modeling and estimation of vegetation height. The purpose of this study was to test the feasibility and accuracy of estimating shrub heights from high-resolution (HR, 3-cm ground sampling distance) digital stereo-pair aerial images. Overlapping HR imagery was taken in March 2009 near Lake Mead, Nevada and 5-cm resolution digital surface models (DSMs) were created by photogrammetric methods (aerial triangulation, digital image matching) for twenty-six test plots. We compared the heights of individual shrubs and plot averages derived from the DSMs to field measurements. We found strong positive correlations between field and image measurements for several metrics. Individual shrub heights tended to be underestimated in the imagery, however, accuracy was higher for dense, compact shrubs compared with shrubs with thin branches. Plot averages of shrub height from DSMs were also strongly correlated to field measurements but consistently underestimated. Grasses and forbs were generally too small to be detected with the resolution of the DSMs. Estimates of

  8. Definition and Proposed Realization of the International Height Reference System (IHRS)

    Science.gov (United States)

    Ihde, Johannes; Sánchez, Laura; Barzaghi, Riccardo; Drewes, Hermann; Foerste, Christoph; Gruber, Thomas; Liebsch, Gunter; Marti, Urs; Pail, Roland; Sideris, Michael

    2017-05-01

    Studying, understanding and modelling global change require geodetic reference frames with an order of accuracy higher than the magnitude of the effects to be actually studied and with high consistency and reliability worldwide. The International Association of Geodesy, taking care of providing a precise geodetic infrastructure for monitoring the Earth system, promotes the implementation of an integrated global geodetic reference frame that provides a reliable frame for consistent analysis and modelling of global phenomena and processes affecting the Earth's gravity field, the Earth's surface geometry and the Earth's rotation. The definition, realization, maintenance and wide utilization of the International Terrestrial Reference System guarantee a globally unified geometric reference frame with an accuracy at the millimetre level. An equivalent high-precision global physical reference frame that supports the reliable description of changes in the Earth's gravity field (such as sea level variations, mass displacements, processes associated with geophysical fluids) is missing. This paper addresses the theoretical foundations supporting the implementation of such a physical reference surface in terms of an International Height Reference System and provides guidance for the coming activities required for the practical and sustainable realization of this system. Based on conceptual approaches of physical geodesy, the requirements for a unified global height reference system are derived. In accordance with the practice, its realization as the International Height Reference Frame is designed. Further steps for the implementation are also proposed.

  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. Derivation of Land Surface Albedo at High Resolution by Combining HJ-1A/B Reflectance Observations with MODIS BRDF Products

    Directory of Open Access Journals (Sweden)

    Bo Gao

    2014-09-01

    Full Text Available Land surface albedo is an essential parameter for monitoring global/regional climate and land surface energy balance. Although many studies have been conducted on global or regional land surface albedo using various remote sensing data over the past few decades, land surface albedo product with a high spatio–temporal resolution is currently very scarce. This paper proposes a method for deriving land surface albedo with a high spatio–temporal resolution (space: 30 m and time: 2–4 days. The proposed method works by combining the land surface reflectance data at 30 m spatial resolution obtained from the charge-coupled devices in the Huanjing-1A and -1B (HJ-1A/B satellites with the Moderate Resolution Imaging Spectroradiometer (MODIS land surface bidirectional reflectance distribution function (BRDF parameters product (MCD43A1, which is at a spatial resolution of 500 m. First, the land surface BRDF parameters for HJ-1A/B land surface reflectance with a spatial–temporal resolutions of 30 m and 2–4 day are calculated on the basis of the prior knowledge from the MODIS BRDF product; then, the calculated high resolution BRDF parameters are integrated over the illuminating/viewing hemisphere to produce the white- and black-sky albedos at 30 m resolution. These results form the basis for the final land surface albedo derivation by accounting for the proportion of direct and diffuse solar radiation arriving at the ground. The albedo retrieved by this novel method is compared with MODIS land surface albedo products, as well as with ground measurements. The results show that the derived land surface albedo during the growing season of 2012 generally achieved a mean absolute accuracy of ±0.044, and a root mean square error of 0.039, confirming the effectiveness of the newly proposed method.

  11. SRTM Colored Height and Shaded Relief: Las Bayas, Argentina

    Science.gov (United States)

    2001-01-01

    The interplay of volcanism, stream erosion and landslides is evident in this Shuttle Radar Topography Mission view of the eastern flank of the Andes Mountains, southeast of San Carlos de Bariloche, Argentina. Older lava flows emanating from the Andes once covered much of this area. Younger, local volcanoes (seen here as small peaks) then covered parts of the area with fresh, erosion resistant flows (seen here as very smooth surfaces). Subsequent erosion has created fine patterns on the older surfaces (bottom of the image) and bolder, irregular patterns through and around the younger surfaces (upper center and right center). Meanwhile, where a large stream immediately borders the resistant plateau (center of the image), lateral erosion has undercut the resistant plateau causing slivers of it to fall into the stream channel. This scene well illustrate show topographic data alone can reveal some aspects of recent geologic history.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. Northern slopes appear bright and southern slopes appear dark, as would be the case at noon at this latitude in the southern hemisphere. 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.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 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

  12. Photochemical properties of mono-, tri-, and penta-cationic antimony(V) metalloporphyrin derivatives on a clay layer surface.

    Science.gov (United States)

    Tsukamoto, Takamasa; Shimada, Tetsuya; Takagi, Shinsuke

    2013-08-22

    Three types of mono-, tri-, and penta-cationic antimony(V) porphyrin derivatives (Sb(V)Pors) were synthesized, and their photochemical properties on the anionic clay were systematically investigated. Sb(V)Por derivatives are dihydroxo(5,10,15,20-tetraphenylporphyrinato)antimony(V) chloride ([Sb(V)(TPP)(OH)2](+)Cl(-)), dihydroxo[5,10-diphenyl-15,20-di(N-methyl-pyridinium-4-yl)porphyrinato]antimony(V) trichloride ([Sb(V)(DMPyP)(OH)2](3+)3Cl(-)), and dihydroxo[5,10,15,20-tetrakis(N-methyl-pyridinium-4-yl)porphyrinato]antimony(V) pentachloride ([Sb(V)(TMPyP)(OH)2](5+)5Cl(-)). The photochemical behaviors of three cationic Sb(V)Pors with and without clay were examined in aqueous solution. For all Sb(V)Por, aggregation behaviors were not observed in the clay complexes even at high density adsorption conditions. The transition probabilities and fluorescence quantum yields of Sb(V)Por showed a tendency to be increased by the complex formation with clay. The less cationic Sb(V)Por/clay complex showed the larger fluorescence quantum yield. The more cationic Sb(V)Por/clay complex showed the longer fluorescence lifetime. These effects of complex formation with clay on the photochemical properties of Sb(V)Pors were discussed using the molecular potential energy curves of the porphyrin ground state and excited state. It is concluded that two types of effects work in the Sb(V)Por/clay system: effect i (structure resembling effect) is that the most stable structure becomes relatively similar between the ground and excited states, mainly by hydrophobic interactions between the porphyrin molecule and the clay surface, and effect ii (structure fixing effect) is that sharpened potential energy curves of clay complexes can lead to the increase of activation energy for the internal conversion from excited state to a high vibration level of ground state, mainly by electrostatic interactions between cationic porphyrin and anionic clay. Like this, the unique effects of the clay surface on

  13. Cell surface-associated anti-MUC1-derived signal peptide antibodies: implications for cancer diagnostics and therapy.

    Directory of Open Access Journals (Sweden)

    Riva Kovjazin

    Full Text Available The MUC1 tumor associated antigen is highly expressed on a range of tumors. Its broad distribution on primary tumors and metastases renders it an attractive target for immunotherapy. After synthesis MUC1 is cleaved, yielding a large soluble extracellular alpha subunit containing the tandem repeats array (TRA domain specifically bound, via non-covalent interaction, to a smaller beta subunit containing the transmembrane and cytoplasmic domains. Thus far, inconclusive efficacy has been reported for anti-MUC1 antibodies directed against the soluble alpha subunit. Targeting the cell bound beta subunit, may bypass limitations posed by circulating TRA domains. MUC1's signal peptide (SP domain promiscuously binds multiple MHC class II and Class I alleles, which upon vaccination, generated robust T-cell immunity against MUC1-positive tumors. This is a first demonstration of non-MHC associated, MUC1 specific, cell surfaces presence for MUC1 SP domain. Polyclonal and monoclonal antibodies generated against MUC1 SP domain specifically bind a large variety of MUC1-positive human solid and haematological tumor cell lines; MUC1-positive bone marrow derived plasma cells obtained from multiple myeloma (MM-patients, but not MUC1 negative tumors cells, and normal naive primary blood and epithelial cells. Membranal MUC1 SP appears mainly as an independent entity but also co-localized with the full MUC1 molecule. MUC1-SP specific binding in BM-derived plasma cells can assist in selecting patients to be treated with anti-MUC1 SP therapeutic vaccine, ImMucin. A therapeutic potential of the anti-MUC1 SP antibodies was suggested by their ability to support of complement-mediated lysis of MUC1-positive tumor cells but not MUC1 negative tumor cells and normal naive primary epithelial cells. These findings suggest a novel cell surface presence of MUC1 SP domain, a potential therapeutic benefit for anti-MUC1 SP antibodies in MUC1-positive tumors and a selection tool for MM

  14. A comparison of consumptive-use estimates derived from the simplified surface energy balance approach and indirect reporting methods

    Science.gov (United States)

    Maupin, Molly A.; Senay, Gabriel B.; Kenny, Joan F.; Savoca, Mark E.

    2012-01-01

    Recent advances in remote-sensing technology and Simplified Surface Energy Balance (SSEB) methods can provide accurate and repeatable estimates of evapotranspiration (ET) when used with satellite observations of irrigated lands. Estimates of ET are generally considered equivalent to consumptive use (CU) because they represent the part of applied irrigation water that is evaporated, transpired, or otherwise not available for immediate reuse. The U.S. Geological Survey compared ET estimates from SSEB methods to CU data collected for 1995 using indirect methods as part of the National Water Use Information Program (NWUIP). Ten-year (2000-2009) average ET estimates from SSEB methods were derived using Moderate Resolution Imaging Spectroradiometer (MODIS) 1-kilometer satellite land surface temperature and gridded weather datasets from the Global Data Assimilation System (GDAS). County-level CU estimates for 1995 were assembled and referenced to 1-kilometer grid cells to synchronize with the SSEB ET estimates. Both datasets were seasonally and spatially weighted to represent the irrigation season (June-September) and those lands that were identified in the county as irrigated. A strong relation (R2 greater than 0.7) was determined between NWUIP CU and SSEB ET data. Regionally, the relation is stronger in arid western states than in humid eastern states, and positive and negative biases are both present at state-level comparisons. SSEB ET estimates can play a major role in monitoring and updating county-based CU estimates by providing a quick and cost-effective method to detect major year-to-year changes at county levels, as well as providing a means to disaggregate county-based ET estimates to sub-county levels. More research is needed to identify the causes for differences in state-based relations.

  15. Estimation of Atmospheric Mixing Layer Height from radiosonde data

    Science.gov (United States)

    Wang, X.; Wang, K.

    2013-12-01

    Mixing layer is the lowest layer of the troposphere where surface turbulence can reach during the daytime. Mixing layer height (MLH) is an important parameter for understanding the transport process, air pollution, weather and climate change. MLH can be determined from the radiosonde profiles of relative humidity (RH), specific humidity (q), potential temperature (θ) and atmospheric refractivity (N) by searching for the strongest gradients of these parameters within a specific height above the surface. However, substantially different MLHs have been found from different parameters. The occurrence of cloud impacts on MLHs derived in two ways: (1) clouds impact the measurements of θ and RH, resulting in spurious MLHs derived by θ and RH, (2) clouds may amplify or depress turbulence, that is MLH can be at cloud top or cloud base when it occurs. However, MLHs determined by existing methods can generally be at cloud top. To solve these problems, we propose a method to estimate MLH by integrating the information of θ, RH, q, N and discriminating different cloud impacts on MLH. We apply this method to high vertical resolution (~30 m) radiosonde data collected at the 79 stations over North America during the period of 1998 to 2008 released by the Stratospheric Processes and their Role in Climate Data Center. The results show good agreement with those from N as the information of temperature and humidity contained in N, however the impact of clouds including in the new method has increased the reliability of MLH. The new results show good agreement with independent MLH determined from Lidar observations. MLH over the North America is 1647×323 meter with a strong east-west gradient, higher MLH (generally greater than 1800 m) over the Midwest America and lower MLH (less than 1300 m) over Alaska and west coast of America. The scatter plot of climatological MLHnew with MLHθ, MLHRH, MLHq, MLHN and MLHint for the period of 1998 to 2008. Pattern of climatological MLH of our

  16. Height Control and Deposition Measurement for the Electron Beam Free Form Fabrication (EBF3) Process

    Science.gov (United States)

    Seufzer, William J. (Inventor); Hafley, Robert A. (Inventor)

    2017-01-01

    A method of controlling a height of an electron beam gun and wire feeder during an electron freeform fabrication process includes utilizing a camera to generate an image of the molten pool of material. The image generated by the camera is utilized to determine a measured height of the electron beam gun relative to the surface of the molten pool. The method further includes ensuring that the measured height is within the range of acceptable heights of the electron beam gun relative to the surface of the molten pool. The present invention also provides for measuring a height of a solid metal deposit formed upon cooling of a molten pool. The height of a single point can be measured, or a plurality of points can be measured to provide 2D or 3D surface height measurements.

  17. Properties of cationic monosubstituted tetraalkylammonium cyclodextrin derivatives – their stability, complexation ability in solution or when deposited on solid anionic surface

    Directory of Open Access Journals (Sweden)

    Martin Popr

    2015-02-01

    Full Text Available The thermal stability of the monosubstituted cationic cyclodextrin (CD derivatives PEMEDA-β-CD and PEMPDA-β-CD, which differ in their substituent linker length (ethylene and propylene, respectively, was studied via 1H NMR experiments. PEMPDA-β-CD exhibited higher resistance towards the Hofmann degradation and was chosen as a more suitable host molecule for further studies. Inclusion properties of PEMPDA-β-CD in solution with a series of simple aromatic guests (salicylic acid, p-methoxyphenol and p-nitroaniline were determined by isothermal titration calorimetry (ITC and compared to the native β-CD. Permanently charged cationic CD derivatives were successfully deposited on the anionic solid surface of polymeric Nafion® 117 membrane via electrostatic interactions. Deposition kinetics and coverage of the surface were determined by ELSD. Finally, the ability of the CD derivatives bound to the solid surface to encapsulate aromatic compounds from aqueous solution was measured by UV–vis spectroscopy. The obtained results are promising for future industrial applications of the monosubstituted β-CD derivatives, because the preparation of cationic CD derivatives is applicable in large scale, without the need of chromatographic purification. Their ionic deposition on a solid surface is simple, yet robust and a straightforward process as well.

  18. Specific anion effects on copper surface through electrochemical treatment: Enhanced photoelectrochemical CO2 reduction activity of derived nanostructures induced by chaotropic anions

    Science.gov (United States)

    Navaee, Aso; Salimi, Abdollah

    2018-05-01

    Copper derivatives are the most prominent CO2 reduction electrocatalyst. Herein, the metallic copper has been electrochemically treated with some of common ionic salts such as N3bar, HPO2bar, S2bar, Fbar, Clbar, Brbar and Ibar based on the dissolution of a metallic working electrode in an aqueous solution to derive the surface roughness incorporated with nanostructures. Diverse surface morphology can be obtained when the ionic radii of anions are changed. Surface study reveals various roughness shapes based on the size and polarity of the anions, where the ions with higher ionic radii have higher impact on the Cu surface. In comparison, polyatomic oxyanion such as HPO2bar even with large ionic radii do not have enough strength to create the surface roughness than that of oxygen-free anions with large ionic radii. The photoelectrochemical behavior of the modified surfaces toward CO2 reduction is studied at a wide potential window in bicarbonate aqueous solution. Based on our investigations, treated surfaces by Ibar, Clbar and S2bargive a more surface roughness, while Ibar and N3bar offer higher catalytic activity toward CO2 reduction due to possible complexing ability of these anions with Cu cations, followed by formation of the co-catalyst semiconductor and facilitate electron transfer. This methodology can be applied to investigate the effect of ions on transition metals along with obtaining different surface morphologies tailored to different applications.

  19. Linoleic acid derivative DCP-LA stimulates vesicular transport of α7 ACh receptors towards surface membrane.

    Science.gov (United States)

    Kanno, Takeshi; Tanaka, Akito; Nishizaki, Tomoyuki

    2012-01-01

    We have earlier found that the linoleic acid derivative DCP-LA could ameliorate learning and memory impairment by targeting α7 ACh receptor. The present study aimed at understanding DCP-LA-regulated α7 ACh receptor trafficking. We monitored currents through α7 ACh receptors expressed in Xenopus oocytes and assayed the receptor mobilizations using fractions with a sucrose density gradient centrifugation, synaptosome preparation, and acutely dissociated neurons from rat hippocampal slices. DCP-LA persistently potentiated α7 ACh receptor currents, and the effect was inhibited by a protein kinase C (PKC) inhibitor or vesicular transport inhibitors. DCP-LA did not induce PKC phosphorylation of α7 ACh receptors. DCP-LA stimulated translocation of α7 ACh receptors from the cytosol toward the plasma membrane or from extra-synaptosomes into synaptosomes and accumulated the receptors at the presynaptic site in hippocampal neurons. The results of the present study demonstrate that DCP-LA increases surface localization of α7 ACh receptors in hippocampal neurons, specifically at presynaptic terminals, by stimulating vesicular transport of the receptors, resulting in potentiation of α7 ACh receptor responses, regardless of PKC phosphorylation of the receptors. Copyright © 2012 S. Karger AG, Basel.

  20. Effect of a novel saponin adjuvant derived from Quillaja saponaria on the immune response to recombinant hepatitis B surface antigen.

    Science.gov (United States)

    So, H S; Yoon, H S; Choi, D Y; Kwon, Y S; Sung, J H; Lee, T G; Park, E S; Cho, H S; Lee, B M; Cho, J M; Ryu, W S

    1997-04-30

    Adjuvant activity of saponins extracted from the South American tree Quillaja saponaria has been demonstrated with many antigens. Recently, four saponin fractions (designated as QS-7, QS-17, QS-18, and QS-21) with adjuvant activity were purified by reverse phase chromatography. In particular, efficacy of the less toxic QS-21 fraction has been demonstrated with several recombinant viral antigens including HIV gp120. Here, we report a novel saponin fraction (designated as QS-L1) derived from Quillaja saponaria. Unlike previously identified saponins, QS-L1 had a different chemical structure and showed adjuvant activity only when administered in the presence of alum-precipitated antigen. Interestingly, the QS-L1 greatly increased not only a humoral immune response but also cellular immune response to recombinant hepatitis B virus surface antigen (HBsAg). Furthermore, QS-L1 showed lower toxicity in vivo and in vitro than the previously identified saponin fraction, QS-21. Finally, we examined the chemical structure of the QS-L1 using mass spectroscopic analysis, carbohydrate composition analysis and NMR spectroscopic analysis. Thus, our results indicated that this novel QS-L1 saponin fraction had several desirable properties required for an effective adjuvant.

  1. Assessment of mixed-layer height estimation from single-wavelength ceilometer profiles

    Science.gov (United States)

    Knepp, Travis N.; Szykman, James J.; Long, Russell; Duvall, Rachelle M.; Krug, Jonathan; Beaver, Melinda; Cavender, Kevin; Kronmiller, Keith; Wheeler, Michael; Delgado, Ruben; Hoff, Raymond; Berkoff, Timothy; Olson, Erik; Clark, Richard; Wolfe, Daniel; Van Gilst, David; Neil, Doreen

    2017-10-01

    Differing boundary/mixed-layer height measurement methods were assessed in moderately polluted and clean environments, with a focus on the Vaisala CL51 ceilometer. This intercomparison was performed as part of ongoing measurements at the Chemistry And Physics of the Atmospheric Boundary Layer Experiment (CAPABLE) site in Hampton, Virginia and during the 2014 Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) field campaign that took place in and around Denver, Colorado. We analyzed CL51 data that were collected via two different methods (BLView software, which applied correction factors, and simple terminal emulation logging) to determine the impact of data collection methodology. Further, we evaluated the STRucture of the ATmosphere (STRAT) algorithm as an open-source alternative to BLView (note that the current work presents an evaluation of the BLView and STRAT algorithms and does not intend to act as a validation of either). Filtering criteria were defined according to the change in mixed-layer height (MLH) distributions for each instrument and algorithm and were applied throughout the analysis to remove high-frequency fluctuations from the MLH retrievals. Of primary interest was determining how the different data-collection methodologies and algorithms compare to each other and to radiosonde-derived boundary-layer heights when deployed as part of a larger instrument network. We determined that data-collection methodology is not as important as the processing algorithm and that much of the algorithm differences might be driven by impacts of local meteorology and precipitation events that pose algorithm difficulties. The results of this study show that a common processing algorithm is necessary for light detection and ranging (lidar)-based MLH intercomparisons and ceilometer-network operation, and that sonde-derived boundary layer heights are higher (10-15 % at midday) than lidar-derived

  2. Assessment of mixed-layer height estimation from single-wavelength ceilometer profiles

    Directory of Open Access Journals (Sweden)

    T. N. Knepp

    2017-10-01

    Full Text Available Differing boundary/mixed-layer height measurement methods were assessed in moderately polluted and clean environments, with a focus on the Vaisala CL51 ceilometer. This intercomparison was performed as part of ongoing measurements at the Chemistry And Physics of the Atmospheric Boundary Layer Experiment (CAPABLE site in Hampton, Virginia and during the 2014 Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ field campaign that took place in and around Denver, Colorado. We analyzed CL51 data that were collected via two different methods (BLView software, which applied correction factors, and simple terminal emulation logging to determine the impact of data collection methodology. Further, we evaluated the STRucture of the ATmosphere (STRAT algorithm as an open-source alternative to BLView (note that the current work presents an evaluation of the BLView and STRAT algorithms and does not intend to act as a validation of either. Filtering criteria were defined according to the change in mixed-layer height (MLH distributions for each instrument and algorithm and were applied throughout the analysis to remove high-frequency fluctuations from the MLH retrievals. Of primary interest was determining how the different data-collection methodologies and algorithms compare to each other and to radiosonde-derived boundary-layer heights when deployed as part of a larger instrument network. We determined that data-collection methodology is not as important as the processing algorithm and that much of the algorithm differences might be driven by impacts of local meteorology and precipitation events that pose algorithm difficulties. The results of this study show that a common processing algorithm is necessary for light detection and ranging (lidar-based MLH intercomparisons and ceilometer-network operation, and that sonde-derived boundary layer heights are higher (10–15 % at

  3. and the CMJ jump height

    Directory of Open Access Journals (Sweden)

    Struzik Artur

    2016-04-01

    Full Text Available Study aim: The elastic potential energy accumulated in the musculotendinous units during the countermovement phase of a jump adds up to the energy supplied by the contracting muscles used in the take-off phase. Consequently, the total mechanical energy used during the jump may reach higher values. Stiffness represents a quantitative measure of a body’s elastic properties. Therefore, the aim of this study was to establish the relationship between leg stiffness and the countermovement jump height.

  4. Regional Distribution of Forest Height and Biomass from Multisensor Data Fusion

    Science.gov (United States)

    Yu, Yifan; Saatchi, Sassan; Heath, Linda S.; LaPoint, Elizabeth; Myneni, Ranga; Knyazikhin, Yuri

    2010-01-01

    Elevation data acquired from radar interferometry at C-band from SRTM are used in data fusion techniques to estimate regional scale forest height and aboveground live biomass (AGLB) over the state of Maine. Two fusion techniques have been developed to perform post-processing and parameter estimations from four data sets: 1 arc sec National Elevation Data (NED), SRTM derived elevation (30 m), Landsat Enhanced Thematic Mapper (ETM) bands (30 m), derived vegetation index (VI) and NLCD2001 land cover map. The first fusion algorithm corrects for missing or erroneous NED data using an iterative interpolation approach and produces distribution of scattering phase centers from SRTM-NED in three dominant forest types of evergreen conifers, deciduous, and mixed stands. The second fusion technique integrates the USDA Forest Service, Forest Inventory and Analysis (FIA) ground-based plot data to develop an algorithm to transform the scattering phase centers into mean forest height and aboveground biomass. Height estimates over evergreen (R2 = 0.86, P < 0.001; RMSE = 1.1 m) and mixed forests (R2 = 0.93, P < 0.001, RMSE = 0.8 m) produced the best results. Estimates over deciduous forests were less accurate because of the winter acquisition of SRTM data and loss of scattering phase center from tree ]surface interaction. We used two methods to estimate AGLB; algorithms based on direct estimation from the scattering phase center produced higher precision (R2 = 0.79, RMSE = 25 Mg/ha) than those estimated from forest height (R2 = 0.25, RMSE = 66 Mg/ha). We discuss sources of uncertainty and implications of the results in the context of mapping regional and continental scale forest biomass distribution.

  5. Improved vertical displacements induced by a refined thermal expansion model and its quantitative analysis in GPS height time series

    Science.gov (United States)

    Wang, Kaihua; Chen, Hua; Jiang, Weiping; Li, Zhao; Ma, Yifang; Deng, Liansheng

    2018-04-01

    There are apparent seasonal variations in GPS height time series, and thermal expansion is considered to be one of the potential geophysical contributors. The displacements introduced by thermal expansion are usually derived without considering the annex height and underground part of the monument (e.g. located on roof or top of the buildings), which may bias the geophysical explanation of the seasonal oscillation. In this paper, the improved vertical displacements are derived by a refined thermal expansion model where the annex height and underground depth of the monument are taken into account, and then 560 IGS stations are adopted to validate the modeled thermal expansion (MTE) displacements. In order to evaluate the impact of thermal expansion on GPS heights, the MTE displacements of 80 IGS stations with less data discontinuities are selected to compare with their observed GPS vertical (OGV) displacements with the modeled surface loading (MSL) displacements removed in advance. Quantitative analysis results show the maximum annual and semiannual amplitudes of the MTE are 6.65 mm (NOVJ) and 0.51 mm (IISC), respectively, and the maximum peak-to-peak oscillation of the MTE displacements can be 19.4 mm. The average annual amplitude reductions are 0.75 mm and 1.05 mm respectively after removing the MTE and MSL displacements from the OGV, indicating the seasonal oscillation induced by thermal expansion is equivalent to >75% of the impact of surface loadings. However, there are rarely significant reductions for the semiannual amplitude. Given the result in this study that thermal expansion can explain 17.3% of the annual amplitude in GPS heights on average, it must be precisely modeled both in GPS precise data processing and GPS time series analysis, especially for those stations located in the middle and high latitudes with larger annual temperature oscillation, or stations with higher monument.

  6. 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 hei...... 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....

  7. 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.

  8. Shaded Relief with Height as Color, Mount Meru, Tanzania

    Science.gov (United States)

    2002-01-01

    Mount Meru is an active volcano located just 70 kilometers (44 miles) west of Mount Kilimanjaro. It reaches 4,566 meters (14,978 feet) in height but has lost much of its bulk due to an eastward volcanic blast sometime in its distant past, perhaps similar to the eruption of Mount Saint Helens in Washington State in 1980. Mount Meru most recently had a minor eruption about a century ago. The several small cones and craters seen in the vicinity probably reflect numerous episodes of volcanic activity. Mount Meru is the topographic centerpiece of Arusha National Park. Its fertile slopes rise above the surrounding savanna and support a forest that hosts diverse wildlife, including nearly 400 species of birds, and also monkeys and leopards.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. Northern slopes appear bright and southern slopes appear dark, as would be the case at noon at this latitude in June. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow, red, and magenta, to blue and white at the highest elevations.Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) 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

  9. Simulation Tool for GNSS Ocean Surface Reflections

    OpenAIRE

    Høeg, Per; von Benzon, Hans-Henrik; Durgonics, Tibor

    2015-01-01

    GNSS coherent and incoherent reflected signals have the potential of deriving large scale parameters of ocean surfaces, as barotropic variability, eddy currents and fronts, Rossby waves, coastal upwelling, mean ocean surfaceheights, and patterns of the general ocean circulation. In the reflection zone the measurements may deriveparameters as sea surface roughness, winds, waves, heights and tilts from the spectral measurements. Previous measurements from the top of mountains and airplanes have...

  10. Validation of three satellite-derived databases of surface solar radiation using measurements performed at 42 stations in Brazil

    Science.gov (United States)

    Thomas, Claire; Wey, Etienne; Blanc, Philippe; Wald, Lucien

    2016-06-01

    The SoDa website (www.soda-pro.com) is populated with numerous solar-related Web services. Among them, three satellite-derived irradiation databases can be manually or automatically accessed to retrieve radiation values within the geographical coverage of the Meteosat Second Generation (MSG) satellite: the two most advanced versions of the HelioClim-3 database (versions 4 and 5, respectively HC3v4 and HC3v5), and the CAMS radiation service. So far, these databases have been validated against measurements of several stations in Europe and North Africa only. As the quality of such databases depends on the geographical regions and the climates, this paper extends this validation campaign and proposes an extensive comparison on Brazil and global irradiation received on a horizontal surface. Eleven stations from the Brazilian Institute of Space Research (INPE) network offer 1 min observations, and thirty-one stations from the Instituto Nacional de Meteorologia (INMET) network offer hourly observations. The satellite-derived estimates have been compared to the corresponding observations on hourly, daily and monthly basis. The bias relative to the mean of the measurements for HC3v5 is mostly comprised between 1 and 3 %, and that for HC3v4 between 2 and 5 %. These are very satisfactory results and they demonstrate that HC3v5, and to a lesser extent HC3v4, may be used in studies of long-term changes in SSI in Brazil. The situation is not so good with CAMS radiation service for which the relative bias is mostly comprised between 5 and 10 %. For hourly irradiation, the relative RMSE ranges from 15 to 33 %. The correlation coefficient is very large for all stations and the three databases, with an average of 0.96. The three databases reproduce well the hour from hour changes in SSI. The errors show a tendency to increase with the viewing angle of the MSG satellite. They are greater in tropical areas where the relative humidity in the atmosphere is important. It is concluded

  11. Space-time extreme wind waves: Analysis and prediction of shape and height

    Science.gov (United States)

    Alvise, Benetazzo; Francesco, Barbariol; Filippo, Bergamasco; Sandro, Carniel; Mauro, Sclavo

    2017-05-01

    In this study, we present the analysis of the temporal profile and height of space-time (ST) extreme wind waves. Wave data were gathered from an observational ST sample of sea surface elevations collected during an active sea state, and they were examined to detect the highest waves (exceeding the rogue wave threshold) of specific 3D wave groups close to the apex of their development. Two different investigations are conducted. Firstly, local maximum elevations of the groups are examined within the framework of statistical models for ST extreme waves, and compared with observations and predictions of maxima derived by one-point time series of sea surface elevations. Secondly, the temporal profile near the maximum wave crests is analyzed and compared with the expectations of the linear and second-order nonlinear extension of the Quasi-Determinism (QD) theory. Our goal is to verify, with real sea data, to what extent, one can estimate the shape and the crest-to-trough height of near-focusing large 3D wave groups using the QD and ST extreme model results. From this study, it emerges that the elevations close to the crest apex are narrowly distributed around a mean profile, whilst a larger dispersion is observed away from the maximum elevation. Yet the QD model furnishes, on average, a fair prediction of the maximum wave heights, especially when nonlinearities are taken into account. Moreover, we discuss how the combination of ST extreme and QD model predictions allows establishing, for a given sea condition, the portrait of waves with very large crest height. Our results show that these theories have the potential to be implemented in a numerical spectral model for wave extreme prediction.

  12. Peroxide decoloration of CI Acid Orange 7 catalyzed by manganese chlorophyll derivatives at the surfaces of micelles and lipid bilayers.

    Science.gov (United States)

    Ishigure, Shuichi; Mitsui, Tatsuro; Ito, Shingo; Kondo, Yuji; Kawabe, Shigeki; Kondo, Masaharu; Dewa, Takehisa; Mino, Hiroyuki; Itoh, Shigeru; Nango, Mamoru

    2010-06-01

    Manganese-substituted chlorophyll a derivatives (MnChls) were synthesized. We first report peroxidative oxidation of an azo dye, CI Acid Orange 7, catalyzed by MnChls at the surfaces of micelles and lipid bilayers with hydrogen peroxide (H(2)O(2)) under mild conditions (pH 8.0, 25 degrees C). Peroxide decoloration depended upon the structures of MnChls, surfactants, lipids, and the presence of imidazole. Surprisingly, a largest decoloration rate was observed for MnChls dimer, MnPChlide a-K(MnPChlide a)-His 5 in cetyltrimethylammonium bromide (CTAB) micellar solution, especially when imidazole was present: this observation is analogous to the decoloration using horseradish peroxidase (HRP). Interestingly, the dimer complexes showed enhanced decoloration in comparison to the corresponding MnChls monomer in the micellar solution. In contrast, the MnChls monomer showed enhanced decoloration in comparison with the MnChls dimer in liposomal suspensions. Further, the imidazole residue covalently linked to the MnChls plays an important role in increasing the decoloration in both micellar and liposomal suspensions as well as in addition of imidazole into the solutions. It is interesting that the electron paramagnetic resonance (EPR) spectra of MnPChlide a ME 2, MnPChlide a-His 3, and MnMPMME-His 7 have 16 peaks around g = 2 in Egg PC or DMPC liposomal suspension with H(2)O(2), which is typical of a mixed-valence Mn(III)-Mn(IV) complex with coupling between two ions. The higher decoloration performance obtained by the monomer porphyrin compounds at the surface of the lipid bilayers appears to be related to the stability of this mixed-valence Mn(III)-Mn(IV) species formed in the lipid bilayers. This finding should provide useful information to note that MnChls, which are easily found in a number of biological systems, are involved in functions such as hydrogen peroxide decomposition in bacteria and the oxidation of water during photosynthesis as well as the peroxidases

  13. Comparison of coral δ18O with pseudocorals derived from in situ sea surface salinity and temperature measurements

    Science.gov (United States)

    DeLong, K. L.; Chaichi, N.; Maupin, C. R.; Richey, J. N.; Quinn, T. M.; Poore, R. Z.

    2015-12-01

    Paleoclimatologists use pseudocorals and forward modeling of coral oxygen isotopes (δ18O) to assess δ18O variations for comparison with climate model output in order to understand past tropical oceanic-atmospheric variability. Oxygen isotopic (δ18Ocoral) variability in shallow water coral skeletons is dependent on sea surface temperature (SST) and δ18O of seawater (δ18Osw), which varies with sea surface salinity (SSS). However, measurements of δ18Osw and SSS are sparse; therefore, simulated SSS (e.g., SODA) is typically used in pseudocoral investigations. Our study site is the Dry Tortugas National Park (DRTO; 24º42'N, 82º48'W) in the southeastern Gulf of Mexico (GOM) where hourly SST and SSS measurements are available from NOAA buoys (1992-2002) and the Florida Keys National Marine Sanctuary (FKNMS; 2011-2014). Here we use bivariate forward modeling of monthly average buoy SSS and SST to develop a time series of pseudocoral δ18O (δ18Op = -0.22(‰/ºC)SST + 0.11(‰/psu)SSS) for DRTO that are compared with δ18Ocoral variations from three Siderastrea siderea coral colonies growing in close proximity within the park. We use the relationship for δ18Osw and SSS determined for Flower Garden Banks coral reef in the northern GOM (27º52'N, 93º49'W) since no measurements of δ18Osw are currently available for DRTO. δ18Op co-varies with δ18Ocoral (r2 = 0.59) with a root mean square error (RMSE = 0.32‰) greater than the intercolony δ18Ocoral variability (r2 = 0.80; RSME = 0.07‰). Discrepancies between δ18Op and δ18Ocoral may be related to the lack of a local SSS-δ18Osw relationship for DRTO or uncertainties in subannual time assignment for δ18Ocoral. A new source of SSS is the NASA satellite Aquarius (2012-2014), which may be useful in future pseudocoral studies, that is evaluated along with high resolution simulated SSS (Global Ocean Physics Reanalysis GLORYS2V3; 1993-2012). We find similar correlation between Aquarius-derived SSS and FKNMS SSS (r2

  14. Where’s the Ground Surface? – Elevation Bias in LIDAR-derived Digital Elevation Models Due to Dense Vegetation in Oregon Tidal Marshes

    Science.gov (United States)

    Light Detection and Ranging (LIDAR) is a powerful resource for coastal and wetland managers and its use is increasing. Vegetation density and other land cover characteristics influence the accuracy of LIDAR-derived ground surface digital elevation models; however the degree to wh...

  15. BRCA1 and p53 protein expression in cultured ovarian surface epithelial cells derived from women with and without a BRCA1 germline mutation.

    NARCIS (Netherlands)

    Piek, J.M.; Dorsman, J.C.; Massuger, L.F.A.G.; Ansink, A.C.; Weegenaar, J.; Shvarts, A.; Kenemans, P.; Verheijen, R.H.

    2006-01-01

    AIM: Mutations in the BRCA1 and TP53 genes are early genetic events leading to (hereditary) ovarian carcinoma. The human ovarian surface epithelium (OSE) is considered the tissue of origin of at least a subset of these tumours. Therefore, OSE cell cultures derived from women harbouring BRCA1

  16. Surface-enhanced Raman scattering detection of DNA derived from the West Nile virus genome using magnetic capture of Raman-active gold nanoparticles

    Science.gov (United States)

    A model paramagnetic nanoparticle (MNP) assay is demonstrated for surface-enhanced Raman scattering (SERS) detection of DNA oligonucleotides derived from the West Nile virus (WNV) genome. Detection is based on the capture of WNV target sequences by hybridization with complementary oligonucleotide pr...

  17. Full-field transmission-type angle-deviation optical microscope with reflectivity-height transformation.

    Science.gov (United States)

    Chiu, Ming-Hung; Tan, Chen-Tai; Tsai, Ming-Hung; Yang, Ya-Hsin

    2015-10-01

    This full-field transmission-type three-dimensional (3D) optical microscope is constructed based on the angle deviation method (ADM) and the algorithm of reflectivity-height transformation (RHT). The surface height is proportional to the deviation angle of light passing through the object. The angle deviation and surface height can be measured based on the reflectivity closed to the critical angle using a parallelogram prism and two CCDs.

  18. Competitive removal of hazardous dyes from aqueous solution by MIL-68(Al): Derivative spectrophotometric method and response surface methodology approach

    Science.gov (United States)

    Tehrani, Mahnaz Saghanejhad; Zare-Dorabei, Rouholah

    2016-05-01

    MIL-68(Al) as a metal-organic framework (MOF) was synthesized and characterized by different techniques such as SEM, BET, FTIR, and XRD analysis. This material was then applied for simulations removal of malachite green (MG) and methylene blue (MB) dyes from aqueous solutions using second order derivative spectrophotometric method (SODS) which was applied to resolve the overlap between the spectra of these dyes. The dependency of dyes removal efficiency in binary solutions was examined and optimized toward various parameters including initial dye concentration, pH of the solution, adsorbent dosage and ultrasonic contact time using central composite design (CCD) under response surface methodology (RSM) approach. The optimized experimental conditions were set as pH 7.78, contact time 5 min, initial MB concentration 22 mg L- 1, initial MG concentration 12 mg L- 1 and adsorbent dosage 0.0055 g. The equilibrium data was fitted to isotherm models such as Langmuir, Freundlich and Tempkin and the results revealed the suitability of the Langmuir model. The maximum adsorption capacity of 666.67 and 153.85 mg g- 1 was obtained for MB and MG removal respectively. Kinetics data fitting to pseudo-first order, pseudo-second order and Elovich models confirmed the applicability of pseudo-second order kinetic model for description of the mechanism and adsorption rate. Dye-loaded MIL-68(Al) can be easily regenerated using methanol and applied for three frequent sorption/desorption cycles with high performance. The impact of ionic strength on removal percentage of both dyes in binary mixture was studied by using NaCl and KCl soluble salts at different concentrations. According to our findings, only small dosage of the proposed MOF is considerably capable to remove large amounts of dyes at room temperature and in very short time that is a big advantage of MIL-68(Al) as a promising adsorbent for adsorptive removal processes.

  19. 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)

  20. Three-dimensional surface velocities of Storstrømmen glacier, Greenland, derived from radar interferometry and ice-sounding radar measurements

    DEFF Research Database (Denmark)

    Reeh, Niels; Mohr, Johan Jacob; Madsen, Søren Nørvang

    2003-01-01

    Non-steady-state vertical velocities of up to 5 m a(-1) exceed the vertical surface-parallel flow (SPF) components over much of the ablation area of Storstrommen, a large outlet glacier from the East Greenland ice sheet. Neglecting a contribution to the vertical velocity of this magnitude results......) or more. This indicates that the SPF assumption may be problematic also for glaciers in steady state. Here we derive the three-dimensional surface velocity distribution of Storstrommen by using the principle of mass conservation (MC) to combine InSAR measurements from ascending and descending satellite...... tracks with airborne ice-sounding radar measurement of ice thickness. The results are compared to InSAR velocities previously derived by using the SPF assumption, and to velocities obtained by in situ global positioning system (GPS) measurements. The velocities derived by using the MC principle...

  1. Mono-fluorinated alkyne-derived SAMs on oxide-free Si(111) surfaces: preparation, characterization and tuning of the Si workfunction.

    Science.gov (United States)

    Pujari, Sidharam P; van Andel, Esther; Yaffe, Omer; Cahen, David; Weidner, Tobias; van Rijn, Cees J M; Zuilhof, Han

    2013-01-15

    Organic monolayers derived from ω-fluoro-1-alkynes of varying carbon chain lengths (C(10)-C(18)) were prepared on Si(111) surfaces, resulting in changes of the physical and electronic properties of the surface. Analysis of the monolayers using XPS, Infrared Reflection Absorption Spectroscopy, ellipsometry and static water contact angle measurements provided information regarding the monolayer thickness, the tilt angle, and the surface coverage. Additionally, PCFF molecular mechanics studies were used to obtain information on the optimal packing density and the layer thickness, which were compared to the experimentally found data. From the results, it can be concluded that the monolayers derived from longer chain lengths are more ordered, possess a lower tilt angle, and have a higher surface coverage than monolayers derived from shorter chains. We also demonstrate that by substitution of an H by F atom in the terminal group, it is possible to controllably modify the surface potential and energy barrier for charge transport in a full metal/monolayer-semiconductor (MOMS) junction.

  2. Multitemporal field-based plant height estimation using 3D point clouds generated from small unmanned aerial systems high-resolution imagery

    Science.gov (United States)

    Malambo, L.; Popescu, S. C.; Murray, S. C.; Putman, E.; Pugh, N. A.; Horne, D. W.; Richardson, G.; Sheridan, R.; Rooney, W. L.; Avant, R.; Vidrine, M.; McCutchen, B.; Baltensperger, D.; Bishop, M.

    2018-02-01

    Plant breeders and agronomists are increasingly interested in repeated plant height measurements over large experimental fields to study critical aspects of plant physiology, genetics and environmental conditions during plant growth. However, collecting such measurements using commonly used manual field measurements is inefficient. 3D point clouds generated from unmanned aerial systems (UAS) images using Structure from Motion (SfM) techniques offer a new option for efficiently deriving in-field crop height data. This study evaluated UAS/SfM for multitemporal 3D crop modelling and developed and assessed a methodology for estimating plant height data from point clouds generated using SfM. High-resolution images in visible spectrum were collected weekly across 12 dates from April (planting) to July (harvest) 2016 over 288 maize (Zea mays L.) and 460 sorghum (Sorghum bicolor L.) plots using a DJI Phantom 3 Professional UAS. The study compared SfM point clouds with terrestrial lidar (TLS) at two dates to evaluate the ability of SfM point clouds to accurately capture ground surfaces and crop canopies, both of which are critical for plant height estimation. Extended plant height comparisons were carried out between SfM plant height (the 90th, 95th, 99th percentiles and maximum height) per plot and field plant height measurements at six dates throughout the growing season to test the repeatability and consistency of SfM estimates. High correlations were observed between SfM and TLS data (R2 = 0.88-0.97, RMSE = 0.01-0.02 m and R2 = 0.60-0.77 RMSE = 0.12-0.16 m for the ground surface and canopy comparison, respectively). Extended height comparisons also showed strong correlations (R2 = 0.42-0.91, RMSE = 0.11-0.19 m for maize and R2 = 0.61-0.85, RMSE = 0.12-0.24 m for sorghum). In general, the 90th, 95th and 99th percentile height metrics had higher correlations to field measurements than the maximum metric though differences among them were not statistically significant. The

  3. 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

  4. Soil hydraulic parameters and surface soil moisture of a tilled bare soil plot inversely derived from l-band brightness temperatures

    KAUST Repository

    Dimitrov, Marin

    2014-01-01

    We coupled a radiative transfer model and a soil hydrologic model (HYDRUS 1D) with an optimization routine to derive soil hydraulic parameters, surface roughness, and soil moisture of a tilled bare soil plot using measured brightness temperatures at 1.4 GHz (L-band), rainfall, and potential soil evaporation. The robustness of the approach was evaluated using five 28-d data sets representing different meteorological conditions. We considered two soil hydraulic property models: the unimodal Mualem-van Genuchten and the bimodal model of Durner. Microwave radiative transfer was modeled by three different approaches: the Fresnel equation with depth-averaged dielectric permittivity of either 2-or 5-cm-thick surface layers and a coherent radiative transfer model (CRTM) that accounts for vertical gradients in dielectric permittivity. Brightness temperatures simulated by the CRTM and the 2-cm-layer Fresnel model fitted well to the measured ones. L-band brightness temperatures are therefore related to the dielectric permittivity and soil moisture in a 2-cm-thick surface layer. The surface roughness parameter that was derived from brightness temperatures using inverse modeling was similar to direct estimates from laser profiler measurements. The laboratory-derived water retention curve was bimodal and could be retrieved consistently for the different periods from brightness temperatures using inverse modeling. A unimodal soil hydraulic property function underestimated the hydraulic conductivity near saturation. Surface soil moisture contents simulated using retrieved soil hydraulic parameters were compared with in situ measurements. Depth-specific calibration relations were essential to derive soil moisture from near-surface installed sensors. © Soil Science Society of America 5585 Guilford Rd., Madison, WI 53711 USA.

  5. 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

  6. Alpine Fault, New Zealand, SRTM Shaded Relief and Colored Height

    Science.gov (United States)

    2005-01-01

    The Alpine fault runs parallel to, and just inland of, much of the west coast of New Zealand's South Island. This view was created from the near-global digital elevation model produced by the Shuttle Radar Topography Mission (SRTM) and is almost 500 kilometers (just over 300 miles) wide. Northwest is toward the top. The fault is extremely distinct in the topographic pattern, nearly slicing this scene in half lengthwise. In a regional context, the Alpine fault is part of a system of faults that connects a west dipping subduction zone to the northeast with an east dipping subduction zone to the southwest, both of which occur along the juncture of the Indo-Australian and Pacific tectonic plates. Thus, the fault itself constitutes the major surface manifestation of the plate boundary here. Offsets of streams and ridges evident in the field, and in this view of SRTM data, indicate right-lateral fault motion. But convergence also occurs across the fault, and this causes the continued uplift of the Southern Alps, New Zealand's largest mountain range, along the southeast side of the fault. 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 (image top to bottom) 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

  7. SRTM Colored Height and Shaded Relief: Lava plateaus in Argentina

    Science.gov (United States)

    2001-01-01

    All of the major landforms relate to volcanism and/or erosion in this Shuttle Radar Topography Mission scene of Patagonia, near La Esperanza, Argentina. The two prominent plateaus once formed a continuous surface that extended over much of this region. Younger volcanoes have grown through and atop the plateau, and one just south of this scene has sent a long, narrow flow down a stream channel (lower left). The topographic pattern shows that streams dominate the erosion processes in this arid environment even though wind is known to move substantial amounts of sediment here.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. Northern slopes appear bright and southern slopes appear dark, as would be the case at noon at this latitude in the southern hemisphere. 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.Elevation data used in this image was acquired by the Shuttle Radar Topography Mission 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 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, CA, for NASA's Earth Science Enterprise, Washington, DC.Size: 62.4 by 88.8 kilometers

  8. Global 30m Height Above the Nearest Drainage

    Science.gov (United States)

    Donchyts, Gennadii; Winsemius, Hessel; Schellekens, Jaap; Erickson, Tyler; Gao, Hongkai; Savenije, Hubert; van de Giesen, Nick

    2016-04-01

    Variability of the Earth surface is the primary characteristics affecting the flow of surface and subsurface water. Digital elevation models, usually represented as height maps above some well-defined vertical datum, are used a lot to compute hydrologic parameters such as local flow directions, drainage area, drainage network pattern, and many others. Usually, it requires a significant effort to derive these parameters at a global scale. One hydrological characteristic introduced in the last decade is Height Above the Nearest Drainage (HAND): a digital elevation model normalized using nearest drainage. This parameter has been shown to be useful for many hydrological and more general purpose applications, such as landscape hazard mapping, landform classification, remote sensing and rainfall-runoff modeling. One of the essential characteristics of HAND is its ability to capture heterogeneities in local environments, difficult to measure or model otherwise. While many applications of HAND were published in the academic literature, no studies analyze its variability on a global scale, especially, using higher resolution DEMs, such as the new, one arc-second (approximately 30m) resolution version of SRTM. In this work, we will present the first global version of HAND computed using a mosaic of two DEMS: 30m SRTM and Viewfinderpanorama DEM (90m). The lower resolution DEM was used to cover latitudes above 60 degrees north and below 56 degrees south where SRTM is not available. We compute HAND using the unmodified version of the input DEMs to ensure consistency with the original elevation model. We have parallelized processing by generating a homogenized, equal-area version of HydroBASINS catchments. The resulting catchment boundaries were used to perform processing using 30m resolution DEM. To compute HAND, a new version of D8 local drainage directions as well as flow accumulation were calculated. The latter was used to estimate river head by incorporating fixed and

  9. Nanotextured Si surfaces derived from block-copolymer self-assembly with superhydrophobic, superhydrophilic, or superamphiphobic properties

    DEFF Research Database (Denmark)

    Telecka, Agnieszka; Li, Tao; Ndoni, Sokol

    2018-01-01

    , or high aspect ratio nano-hoodoo features (overhang profile structures) with a diameter below 100 nm. The surfaces are finally functionalized with either hydrophobic surface chemistry by self-assembly from the precursor perfluorodecyltrichlorosilane (FDTS), or hydrophilic surface chemistry obtained...

  10. Mitigation of biofilm formation on corrugated cardboard fresh produce packaging surfaces using a novel thiazolidinedione derivative integrated in acrylic emulsion polymers

    Directory of Open Access Journals (Sweden)

    Michael eBrandwein

    2016-02-01

    Full Text Available Various surfaces associated with the storage and packing of food are known to harbor distinct bacterial pathogens. Conspicuously absent among the plethora of studies implicating food packaging materials and machinery is the study of corrugated cardboard packaging, the worldwide medium for transporting fresh produce. In this study, we observed the microbial communities of three different store-bought fruits and vegetables, along with their analogue cardboard packaging using high throughput sequencing technology. We further developed an anti-biofilm polymer meant to coat corrugated cardboard surfaces and mediate bacterial biofilm growth on said surfaces. Integration of a novel thiazolidinedione derivative into the acrylic emulsion polymers was assessed using Energy Dispersive X-ray Spectrometry analysis and surface topography was visualized and quantified on corrugated cardboard surfaces. Biofilm growth was measured using q-PCR targeting the gene encoding 16s rRNA. Additionally, architectural structure of the biofilm was observed using SEM. The uniform integration of the thiazolidinedione derivative TZD-6 was confirmed, and it was determined via q-PCR to reduce biofilm growth by ~80% on tested surfaces. A novel and effective method for reducing microbial load and preventing contamination on food packaging is thereby proposed.

  11. Design, Synthesis, and Use of Peptides Derived from Human Papillomavirus L1 Protein for the Modification of Gold Electrode Surfaces by Self-Assembled Monolayers.

    Science.gov (United States)

    Lara Carrillo, John Alejandro; Fierro Medina, Ricardo; Manríquez Rocha, Juan; Bustos Bustos, Erika; Insuasty Cepeda, Diego Sebastián; García Castañeda, Javier Eduardo; Rivera Monroy, Zuly Jenny

    2017-11-14

    In order to obtain gold electrode surfaces modified with Human Papillomavirus L1 protein (HPV L1)-derived peptides, two sequences, SPINNTKPHEAR and YIK, were chosen. Both have been recognized by means of sera from patients infected with HPV. The molecules, Fc-Ahx-SPINNTKPHEAR, Ac-C- Ahx -(Fc)KSPINNTKPHEAR, Ac-C- Ahx -SPINNTKPHEAR(Fc)K, C- Ahx -SPINNTKPHEAR, and (YIK)₂- Ahx -C, were designed, synthesized, and characterized. Our results suggest that peptides derived from the SPINNTKPHEAR sequence, containing ferrocene and cysteine residues, are not stable and not adequate for electrode surface modification. The surface of polycrystalline gold electrodes was modified with the peptides C-Ahx-SPINNTKPHEAR or (YIK)₂-Ahx-C through self-assembly. The modified polycrystalline gold electrodes were characterized via infrared spectroscopy and electrochemical measurements. The thermodynamic parameters, surface coverage factor, and medium pH effect were determined for these surfaces. The results indicate that surface modification depends on the peptide sequence (length, amino acid composition, polyvalence, etc.). The influence of antipeptide antibodies on the voltammetric response of the modified electrode was evaluated by comparing results obtained with pre-immune and post-immune serum samples.

  12. Optimal Inflatable Space Towers of High Height

    Science.gov (United States)

    Bolonkin, Alexander

    2002-01-01

    Author provides theory and computations for building inflatable space towers up to a hundred km in height. These towers can be used for tourism; scientific observation of space, earth's surface, weather, top atmosphere, as well as for radio, television, and communication transmissions. These towers can also be used to launch space ships and Earth satellites. These projects are not expensive and do not require rockets. They require thin strong films composed from artificial fibers and fabricated by current industry. Towers can be built using present technology. Towers can be used (for tourism, communication, etc.) during the construction process and provide self-financing for further construction. The tower design does not require work at high altitudes; all construction can be done at the earth's surface. The transport system for this tower consists a small engine (used only for friction compensation) located at the earth's surface. The tower is separated into sections and has special protection mechanism in case of a damage. Problems involving security, control, repair, and stability of the proposed towers are addressed in subsequent publications. The author is prepared to discuss these and other problems with serious organizations desiring to research and develop these projects.

  13. Nomogram for the height of the daytime mixed layer

    DEFF Research Database (Denmark)

    Nyren, K.; Gryning, Sven-Erik

    1999-01-01

    A method to construct a nomogram of the daytime mixed-layer-height evolution is presented. The nomogram will be specific for a given location and land surface type and is intended to be an easy tool to achieve a general understanding of mixed-layer behaviour. Also it is a pedagogical graphical on...

  14. Surface-enhanced Raman Scattering Study of the Binding Modes of a Dibenzotetraaza[14]annulene Derivative with DNA/RNA Polynucleotides

    OpenAIRE

    Miljanić, Snežana; Dijanošić, Adriana; Kalac, Matea; Radić Stojković, Marijana; Piantanida, Ivo; Pawlica, Dariusz; Eilmes, Julita

    2012-01-01

    Binding modes of a dibenzotetraaza14annulene (DBTAA) derivative with synthetic nucleic acids were studied using surface-enhanced Raman spectroscopy (SERS). Changes in SERS intensity and appearance of new bands in spectra were attributed to different complexes formed between the DBTAA molecules and DNA/RNA polynucleotides. A decrease in intensity pointed to intercalation as the dominant binding mode of the annulene derivative with poly dGdC-poly dGdC and poly rA-poly rU, whereas new bands in...

  15. 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; Deloukas, Panos; Watkins, Hugh; Schunkert, Heribert; Danesh, John; Thompson, John R.; Samani, Nilesh J.; Assimes, Themistocles; Goldstein, Benjamin A.; Stirrups, Kathleen; Cazier, Jean-Baptiste; Johansson, Åsa; Lee, Jong-Young; Chambers, John C.; Esko, Tõnu; Folkersen, Lasse; Goel, Anuj; Grundberg, Elin; Havulinna, Aki S.; Ho, Weang K.; Hopewell, Jemma C.; Eriksson, Niclas; Kleber, Marcus E.; Kristiansson, Kati; Lundmark, Per; Lyytikäinen, Leo-Pekka; Rafelt, Suzanne; Shungin, Dmitry; Strawbridge, Rona J.; Thorleifsson, Gudmar; Tikkanen, Emmi; van Zuydam, Natalie; Voight, Benjamin F.; Waite, Lindsay L.; Zhang, Weihua; Ziegler, Andreas; Absher, Devin; Altshuler, David; Balmforth, Anthony J.; Barroso, Inês; Braund, Peter S.; Burgdorf, Christof; Claudi-Boehm, Simone; Cox, David; Dimitriou, Maria; Do, Ron; Doney, Alex S. F.; El Mokhtari, NourEddine; Eriksson, Per; Fischer, Krista; Fontanillas, Pierre; Franco-Cereceda, Anders; Gigante, Bruna; Gustafsson, Stefan; Hager, Jörg; Hallmans, Göran; Han, Bok-Ghee; Hunt, Sarah E.; Kang, Hyun M.; Illig, Thomas; Kessler, Thorsten; Knowles, Joshua W.; Kolovou, Genovefa; Kuusisto, Johanna; Langenberg, Claudia; Langford, Cordelia; Leander, Karin; Lokki, Marja-Liisa; Lundmark, Anders; McCarthy, Mark I.; Meisinger, Christa; Melander, Olle; Mihailov, Evelin; Maouche, Seraya; Morris, Andrew D.; Müller-Nurasyid, Martina; Nikus, Kjell; Peden, John F.; Rayner, N. William; Rasheed, Asif; Rosinger, Silke; Rubin, Diana; Rumpf, Moritz P.; Schäfer, Arne; Sivananthan, Mohan; Song, Ci; Stewart, Alexandre F. R.; Tan, Sian-Tsung; Thorgeirsson, Gudmundur; van der Schoot, C. Ellen; Wagner, Peter J.; Wells, George A.; Wild, Philipp S.; Yang, Tsun-Po; Amouyel, Philippe; Arveiler, Dominique; Basart, Hanneke; Boehnke, Michael; Boerwinkle, Eric; Brambilla, Paolo; Cambien, Francois; Cupples, Adrienne L.; de Faire, Ulf; Dehghan, Abbas; Diemert, Patrick; Epstein, Stephen E.; Evans, Alun; Ferrario, Marco M.; Ferrières, Jean; Gauguier, Dominique; Go, Alan S.; Goodall, Alison H.; Gudnason, Villi; Hazen, Stanley L.; Holm, Hilma; Iribarren, Carlos; Jang, Yangsoo; Kähönen, Mika; Kim, Hyo-Soo; Klopp, Norman; Koenig, Wolfgang; Kratzer, Wolfgang; Kuulasmaa, Kari; Laakso, Markku; Laaksonen, Reijo; Lee, Ji-Young; Lind, Lars; Ouwehand, Willem H.; Parish, Sarah; Park, Jeong E.; Pedersen, Nancy L.; Quertermous, Thomas; Rader, Daniel J.; Schadt, Eric; Sinisalo, Juha; Stark, Klaus; Stefansson, Kari; Trégouët, David-Alexandre; Virtamo, Jarmo; Wallentin, Lars; Zimmermann, Martina E.; Sandhu, Manjinder S.; Pastinen, Tomi; Syvänen, Ann-Christine; Blankenberg, Stefan S.; Clarke, Robert; O'Donnell, Christopher; März, Winfried; Kooner, Jaspal S.

    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

  16. Facile Fabrication and Characterization of a PDMS-Derived Candle Soot Coated Stable Biocompatible Superhydrophobic and Superhemophobic Surface.

    Science.gov (United States)

    Iqbal, R; Majhy, B; Sen, A K

    2017-09-13

    We report a simple, inexpensive, rapid, and one-step method for the fabrication of a stable and biocompatible superhydrophobic and superhemophobic surface. The proposed surface comprises candle soot particles embedded in a mixture of PDMS+n-hexane serving as the base material. The mechanism responsible for the superhydrophobic behavior of the surface is explained, and the surface is characterized based on its morphology and elemental composition, wetting properties, mechanical and chemical stability, and biocompatibility. The effect of %n-hexane in PDMS, the thickness of the PDMS+n-hexane layer (in terms of spin coating speed) and sooting time on the wetting property of the surface is studied. The proposed surface exhibits nanoscale surface asperities (average roughness of 187 nm), chemical compositions of soot particles, very high water and blood repellency along with excellent mechanical and chemical stability and excellent biocompatibility against blood sample and biological cells. The water contact angle and roll-off angle is measured as 160° ± 1° and 2°, respectively, and the blood contact angle is found to be 154° ± 1°, which indicates that the surface is superhydrophobic and superhemophobic. The proposed superhydrophobic and superhemophobic surface offers significantly improved (>40%) cell viability as compared to glass and PDMS surfaces.

  17. USING COMBINATION OF PLANAR AND HEIGHT FEATURES FOR DETECTING BUILT-UP AREAS FROM HIGH-RESOLUTION STEREO IMAGERY

    Directory of Open Access Journals (Sweden)

    F. Peng

    2017-09-01

    Full Text Available Within-class spectral variation and between-class spectral confusion in remotely sensed imagery degrades the performance of built-up area detection when using planar texture, shape, and spectral features. Terrain slope and building height are often used to optimize the results, but extracted from auxiliary data (e.g. LIDAR data, DSM. Moreover, the auxiliary data must be acquired around the same time as image acquisition. Otherwise, built-up area detection accuracy is affected. Stereo imagery incorporates both planar and height information unlike single remotely sensed images. Stereo imagery acquired by many satellites (e.g. Worldview-4, Pleiades-HR, ALOS-PRISM, and ZY-3 can be used as data source of identifying built-up areas. A new method of identifying high-accuracy built-up areas from stereo imagery is achieved by using a combination of planar and height features. The digital surface model (DSM and digital orthophoto map (DOM are first generated from stereo images. Then, height values of above-ground objects (e.g. buildings are calculated from the DSM, and used to obtain raw built-up areas. Other raw built-up areas are obtained from the DOM using Pantex and Gabor, respectively. Final high-accuracy built-up area results are achieved from these raw built-up areas using the decision level fusion. Experimental results show that accurate built-up areas can be achieved from stereo imagery. The height information used in the proposed method is derived from stereo imagery itself, with no need to require auxiliary height data (e.g. LIDAR data. The proposed method is suitable for spaceborne and airborne stereo pairs and triplets.

  18. Laboratory Study of Dispersion of Buoyant Surface Plumes

    DEFF Research Database (Denmark)

    Petersen, Ole; Larsen, Torben

    1990-01-01

    A laboratory a study on surface dispersion of buoyant plumes in open channel turbulence in made, where the buoyancy is due to both salinity and heat. The measured parameters are the downstream derivative of a plume width and height, which are integral-characteristics of the distributions of density...

  19. Effects and interactions of medium components on laccase from a marine-derived fungus using response surface methodology

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza-Ticlo, D.; Garg, S.; Raghukumar, C.

    The effects of various synthetic medium components and their interactions with each other ultimately impact laccase production in fungi. This was studied using a laccase-hyper-producing marine-derived basidiomycete, Cerrena unicolor MTCC 5159...

  20. Estimates of forest height in the Amazon basin using radar altimeter data of SARIN mode onboard Cryosat-2

    Science.gov (United States)

    Yang, L.; Sun, G.; Liu, Q.

    2013-12-01

    Forest height is an important parameter for global carbon cycle studies. New technologies are required since the end of the operation ofGeoscience Laser Altimeter System (GLAS) onboard The Ice, Cloud, and land Elevation Satellite (IceSat) in 2009. CryoSat-2 is a European Space Agencyenvironmental research satellite which was launched in April 2010.The SIRAL (SAR Interferometer Radar Altimeter) on board CryoSat-2 provides three operational modes for different observational requirements. Before the launch of Icesat2 around July 2016, CryoSat data represents a unique source of information on regional-to-global scale forest canopy height.We propose to use radar altimetry waveforms from the synthetic aperture/interferometric (SARin) mode to estimate canopy height in the Amazon basin. To understand the relation between canopy structure and the SIRAL waveform in Ku band, a 3D model was developed and implemented based on a Lidar model by introducingthe scattering items from crown, trunk and ground surface at Ku band. The vertical distribution of tree crown volume within a SIRAL footprint was calculated from its 3-D stand model by summing the volumes of all tree crown cells at the same height from the ground. The preliminary comparisons between simulated and measured SIRAL waveforms show that the model captures the major characteristics of the SIRAL signature. Cryosat waveform data of SARin mode and from June, 2011 to June, 2012 (cycle 04) is used to retrieve canopy height at Amazon basin under Cryosat groundtrack. The canopy height is derived by extracting the key points of vegetation and ground returns after noise estimation. Because of lack of field tree height measurement in 2012 at Amazon, we validated the results using the field measurements at four areas (the km 67 camp, the km 77 camp, Ruropolis, the Taoajos river) of Tapajos National Forest, Brazil in November 1999, and compared the results with the canopy height estimation from previous studies using Laser

  1. AC and DC global electric circuit properties and the height profile of atmospheric conductivity

    Directory of Open Access Journals (Sweden)

    Irina G. Kudintseva

    2016-11-01

    Full Text Available An apparent discrepancy is pointed out - at all heights, and by up to an order of magnitude - between the height profiles of atmospheric conductivity derived at AC using ELF propagation studies, especially from information on Schumann resonance of the Earth-ionosphere cavity, and using a model of the DC global atmospheric electric circuit. This serious issue is resolved by creating a hybrid profile of these two mid-latitude profiles, the first of which refers to conditions by day and the second by night. This hybrid profile is thus a first order attempt to represent globally averaged conditions. Close to the Earth’s surface, where the resistance of the atmosphere is largest, the properties of the DC global model exert the greatest influence, whereas in the middle atmosphere, at heights between 40 and 100 km, full wave computations show that the AC results are the more crucial. The globally averaged hybrid profile presented here has some limitations, and the physical reasons for these are addressed. They are due to the presence of aerosol particles of ice and/or of meteoric material which reduce the ionospheric D-region conductivity by an order of magnitude over only ~2 km of height, thereby causing ledges of ionisation. In the context of the globally averaged profile, published observations of the ionospheric effects of the giant gamma-ray flare from SGR 1806-20 (a neutron star having an enormously large magnetic field occurring at 21:30 U.T. on December 27, 2004, are briefly discussed.

  2. Comparison of Placido disc and Scheimpflug image-derived topography-guided excimer laser surface normalization combined with higher fluence CXL: the Athens Protocol, in progressive keratoconus

    Directory of Open Access Journals (Sweden)

    Kanellopoulos AJ

    2013-07-01

    Full Text Available Anastasios John Kanellopoulos,1,2 George Asimellis11Laservision.gr Eye Institute, Athens, Greece; 2New York University School of Medicine, Department of Opthalmology, NY, NY, USABackground: The purpose of this study was to compare the safety and efficacy of two alternative corneal topography data sources used in topography-guided excimer laser normalization, combined with corneal collagen cross-linking in the management of keratoconus using the Athens protocol, ie, a Placido disc imaging device and a Scheimpflug imaging device.Methods: A total of 181 consecutive patients with keratoconus who underwent the Athens protocol between 2008 and 2011 were studied preoperatively and at months 1, 3, 6, and 12 postoperatively for visual acuity, keratometry, and anterior surface corneal irregularity indices. Two groups were formed, depending on the primary source used for topoguided photoablation, ie, group A (Placido disc and group B (Scheimpflug rotating camera. One-year changes in visual acuity, keratometry, and seven anterior surface corneal irregularity indices were studied in each group.Results: Changes in visual acuity, expressed as the difference between postoperative and preoperative corrected distance visual acuity were +0.12 ± 0.20 (range +0.60 to -0.45 for group A and +0.19 ± 0.20 (range +0.75 to -0.30 for group B. In group A, K1 (flat keratometry changed from 45.202 ± 3.782 D to 43.022 ± 3.819 D, indicating a flattening of -2.18 D, and K2 (steep keratometry changed from 48.670 ± 4.066 D to 45.865 ± 4.794 D, indicating a flattening of -2.805 D. In group B, K1 (flat keratometry changed from 46.213 ± 4.082 D to 43.190 ± 4.398 D, indicating a flattening of -3.023 D, and K2 (steep keratometry changed from 50.774 ± 5.210 D to 46.380 ± 5.006 D, indicating a flattening of -4.394 D. For group A, the index of surface variance decreased to -5.07% and the index of height decentration to -26.81%. In group B, the index of surface variance

  3. A rigorous assessment of tree height measurements obtained using airborne LIDAR and conventional field methods.

    Science.gov (United States)

    Hans-Erik Andersen; Stephen E. Reutebuch; Robert J. McGaughey

    2006-01-01

    Tree height is an important variable in forest inventory programs but is typically time-consuming and costly to measure in the field using conventional techniques. Airborne light detection and ranging (LIDAR) provides individual tree height measurements that are highly correlated with field-derived measurements, but the imprecision of conventional field techniques does...

  4. Monitoring glacier albedo as a proxy to derive summer and annual surface mass balances from optical remote-sensing data

    Science.gov (United States)

    Davaze, Lucas; Rabatel, Antoine; Arnaud, Yves; Sirguey, Pascal; Six, Delphine; Letreguilly, Anne; Dumont, Marie

    2018-01-01

    Less than 0.25 % of the 250 000 glaciers inventoried in the Randolph Glacier Inventory (RGI V.5) are currently monitored with in situ measurements of surface mass balance. Increasing this archive is very challenging, especially using time-consuming methods based on in situ measurements, and complementary methods are required to quantify the surface mass balance of unmonitored glaciers. The current study relies on the so-called albedo method, based on the analysis of albedo maps retrieved from optical satellite imagery acquired since 2000 by the MODIS sensor, on board the TERRA satellite. Recent studies revealed substantial relationships between summer minimum glacier-wide surface albedo and annual surface mass balance, because this minimum surface albedo is directly related to the accumulation-area ratio and the equilibrium-line altitude. On the basis of 30 glaciers located in the French Alps where annual surface mass balance data are available, our study conducted on the period 2000-2015 confirms the robustness and reliability of the relationship between the summer minimum surface albedo and the annual surface mass balance. For the ablation season, the integrated summer surface albedo is significantly correlated with the summer surface mass balance of the six glaciers seasonally monitored. These results are promising to monitor both annual and summer glacier-wide surface mass balances of individual glaciers at a regional scale using optical satellite images. A sensitivity study on the computed cloud masks revealed a high confidence in the retrieved albedo maps, restricting the number of omission errors. Albedo retrieval artifacts have been detected for topographically incised glaciers, highlighting limitations in the shadow correction algorithm, although inter-annual comparisons are not affected by systematic errors.

  5. SRTM Colored Height and Shaded Relief: Corral de Piedra, Argentina

    Science.gov (United States)

    2001-01-01

    Volcanism and erosion are prominently seen in this view of the eastern flank of the Andes Mountains taken by Shuttle Radar Topography Mission (SRTM). The area is southeast of San Martin de Los Andes, Argentina. Eroded peaks up to 2,210-meter-high (7,260-foot) are seen on the west (left), but much of the scene consists of lava plateaus that slope gently eastward. These lava flows were most likely derived from volcanic sources in the high mountains. However, younger and more localized volcanic activity is evident in the topographic data as a cone surrounding oval-shaped flow near the center of the scene.The plateaus are extensively eroded by the Rio Limay (bottom of the image) and the Rio Collon Cura and its tributaries (upper half). The larger stream channels have reached a stable level and are now cutting broad valleys. Few terraces between the levels of the high plateaus and lower valleys (bottom center and upper right of the volcanic cone) indicate that stream erosion had once temporarily reached a higher stable level before eroding down to its current level. In general, depositional surfaces like lava flows are progressively younger with increasing elevation, while erosional surfaces are progressively younger with decreasing elevation.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. Northern slopes appear bright and southern slopes appear dark, as would be the case at noon at this latitude in the southern hemisphere. 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.Elevation data used in this image was 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

  6. replacing orthometric heights with ellipsoidal heights in engineering

    African Journals Online (AJOL)

    user

    Ellipsoid is a good approximation to the shape of the earth but not an exact representation. It is the only regular surface ... Spirit levelling is the dominant technique for providing elevation above MSL. The equipment are ... and in most cases established a local datum to do the work. This practice has created a situation where.

  7. Surface Aerodynamic Temperature Derived from Wind/Termperature Profile Measurements Over Cotton and Alfalfa in a Semi-Arid Environment

    Science.gov (United States)

    Assessing the project efficiency of irrigation systems and water use efficiency of crops over large irrigated areas requires daily or seasonal evapotranspiration (ET) maps. Mapping ET or latent heat flux (LE) can be achieved spatially for land surfaces using remote sensing inputs such as surface ref...

  8. The influence of surface plasmons on the optical properties of composite films on the basis of poly(3-hexylthiophene), fullerene derivatives, and nickel nanoparticles

    Science.gov (United States)

    Chikalova-Luzina, O. P.; Samosvat, D. M.; Aleshin, A. N.

    2017-08-01

    It is shown that a previously discovered effect of the introduction of Ni nanoparticles into films on the basis of poly(3-hexylthiophene) and fullerene derivatives (P3HT: [60]PCBM: Ni), which consists in increasing the light absorption and photoluminescence quenching in the spectral range from 400 to 620 nm, can be theoretically explained as being a result of the influence of surface plasmon resonance of Ni nanoparticles on the optical properties of P3HT: [60]PCBM: Ni composite films.

  9. Lipase-catalyzed baeyer-villiger oxidation of cellulose-derived levoglucosenone into (s)-gamma-hydroxymethyl-alpha,beta-butenolide: optimization by response surface methodology

    OpenAIRE

    Teixeira, Andreia; Flourat, Amandine; Peru, Aurelien A. M.; Brunissen, Fanny; Allais, Florent

    2016-01-01

    Cellulose-derived levoglucosenone (LGO) has been efficiently converted into pure (S)-gamma-hydroxymethyl-alpha,beta-butenolide (HBO), a chemical platform suited for the synthesis of drugs, flavors and antiviral agents. This process involves two-steps: a lipase-catalyzed Baeyer-Villiger oxidation of LGO followed by an acid hydrolysis of the reaction mixture to provide pure HBO. Response surface methodology (RSM), based on central composite face-centered (CCR design, was employed to evaluate th...

  10. Biological Response of Human Bone Marrow-Derived Mesenchymal Stem Cells to Commercial Tantalum Coatings with Microscale and Nanoscale Surface Topographies

    Science.gov (United States)

    Skoog, Shelby A.; Kumar, Girish; Goering, Peter L.; Williams, Brian; Stiglich, Jack; Narayan, Roger J.

    2016-06-01

    Tantalum is a promising orthopaedic implant coating material due to its robust mechanical properties, corrosion resistance, and excellent biocompatibility. Previous studies have demonstrated improved biocompatibility and tissue integration of surface-treated tantalum coatings compared to untreated tantalum. Surface modification of tantalum coatings with biologically inspired microscale and nanoscale features may be used to evoke optimal tissue responses. The goal of this study was to evaluate commercial tantalum coatings with nanoscale, sub-microscale, and microscale surface topographies for orthopaedic and dental applications using human bone marrow-derived mesenchymal stem cells (hBMSCs). Tantalum coatings with different microscale and nanoscale surface topographies were fabricated using a diffusion process or chemical vapor deposition. Biological evaluation of the tantalum coatings using hBMSCs showed that tantalum coatings promote cellular adhesion and growth. Furthermore, hBMSC adhesion to the tantalum coatings was dependent on surface feature characteristics, with enhanced cell adhesion on sub-micrometer- and micrometer-sized surface topographies compared to hybrid nano-/microstructures. Nanostructured and microstructured tantalum coatings should be further evaluated to optimize the surface coating features to promote osteogenesis and enhance osseointegration of tantalum-based orthopaedic implants.

  11. CMS: Mangrove Canopy Height Estimates from Remote Imagery, Zambezi Delta, Mozambique

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides high resolution canopy height estimates for mangrove forests in the Zambezi Delta, Mozambique, Africa. The estimates were derived from three...

  12. Impact of highway construction on land surface energy balance and local climate derived from LANDSAT satellite data.

    Science.gov (United States)

    Nedbal, Václav; Brom, Jakub

    2018-03-26

    Extensive construction of highways has a major impact on the landscape and its structure. They can also influence local climate and heat fluxes in the surrounding area. After the removal of vegetation due to highway construction, the amount of solar radiation energy used for plant evapotranspiration (latent heat flux) decreases, bringing about an increase in landscape surface temperature, changing the local climate and increasing surface run-off. In this study, we evaluated the impact of the D8 highway construction (Central Bohemia, Czech Republic) on the distribution of solar radiation energy into the various heat fluxes (latent, sensible and ground heat flux) and related surface functional parameters (surface temperature and surface wetness). The aim was to describe the severity of the impact and the distance from the actual highway in which it can be observed. LANDSAT multispectral satellite images and field meteorological measurements were used to calculate surface functional parameters and heat balance before and during the highway construction. Construction of a four-lane highway can influence the heat balance of the landscape surface as far as 90m in the perpendicular direction from the highway axis, i.e. up to 75m perpendicular from its edge. During a summer day, the decrease in evapotranspired water can reach up to 43.7m 3 per highway kilometre. This means a reduced cooling effect, expressed as the decrease in latent heat flux, by an average of 29.7MWh per day per highway kilometre and its surroundings. The loss of the cooling ability of the land surface by evaporation can lead to a rise in surface temperature by as much as 7°C. Thus, the results indicate the impact of extensive line constructions on the local climate. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. 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.

  14. 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