WorldWideScience

Sample records for earth surface processes

  1. Quantitative Modeling of Earth Surface Processes

    Science.gov (United States)

    Pelletier, Jon D.

    This textbook describes some of the most effective and straightforward quantitative techniques for modeling Earth surface processes. By emphasizing a core set of equations and solution techniques, the book presents state-of-the-art models currently employed in Earth surface process research, as well as a set of simple but practical research tools. Detailed case studies demonstrate application of the methods to a wide variety of processes including hillslope, fluvial, aeolian, glacial, tectonic, and climatic systems. Exercises at the end of each chapter begin with simple calculations and then progress to more sophisticated problems that require computer programming. All the necessary computer codes are available online at www.cambridge.org/9780521855976. Assuming some knowledge of calculus and basic programming experience, this quantitative textbook is designed for advanced geomorphology courses and as a reference book for professional researchers in Earth and planetary science looking for a quantitative approach to Earth surface processes. More details...

  2. The esa earth explorer land surface processes and interactions mission

    Science.gov (United States)

    Labandibar, Jean-Yves; Jubineau, Franck; Silvestrin, Pierluigi; Del Bello, Umberto

    2017-11-01

    The European Space Agency (ESA) is defining candidate missions for Earth Observation. In the class of the Earth Explorer missions, dedicated to research and pre-operational demonstration, the Land Surface Processes and Interactions Mission (LSPIM) will acquire the accurate quantitative measurements needed to improve our understanding of the nature and evolution of biosphere-atmosphere interactions and to contribute significantly to a solution of the scaling problems for energy, water and carbon fluxes at the Earth's surface. The mission is intended to provide detailed observations of the surface of the Earth and to collect data related to ecosystem processes and radiation balance. It is also intended to address a range of issues important for environmental monitoring, renewable resources assessment and climate models. The mission involves a dedicated maneuvering satellite which provides multi-directional observations for systematic measurement of Land Surface BRDF (BiDirectional Reflectance Distribution Function) of selected sites on Earth. The satellite carries an optical payload : PRISM (Processes Research by an Imaging Space Mission), a multispectral imager providing reasonably high spatial resolution images (50 m over 50 km swath) in the whole optical spectral domain (from 450 nm to 2.35 μm with a resolution close to 10 nm, and two thermal bands from 8.1 to 9.1 μm). This paper presents the results of the Phase A study awarded by ESA, led by ALCATEL Space Industries and concerning the design of LSPIM.

  3. Publications of the Western Earth Surfaces Processes Team 2005

    Science.gov (United States)

    Powell, Charles; Stone, Paul

    2007-01-01

    Introduction The Western Earth Surface Processes Team (WESPT) of the U.S. Geological Survey (USGS) conducts geologic mapping, earth-surface process investigations, and related topical earth science studies in the western United States. This work is focused on areas where modern geologic maps and associated earth-science data are needed to address key societal and environmental issues such as ground-water quality, landslides and other potential geologic hazards, and land-use decisions. Areas of primary emphasis in 2005 included southern California, the San Francisco Bay region, the Mojave Desert, the Colorado Plateau region of northern Arizona, and the Pacific Northwest. The team has its headquarters in Menlo Park, California, and maintains smaller field offices at several other locations in the western United States. The results of research conducted by the WESPT are released to the public as a variety of databases, maps, text reports, and abstracts, both through the internal publication system of the USGS and in diverse external publications such as scientific journals and books. This report lists publications of the WESPT released in 2005 as well as additional 2002, 2003, and 2004 publications that were not included in the previous lists (USGS Open-File Reports 03-363, 2004- 1267, 2005-1362). Most of the publications listed were authored or coauthored by WESPT staff. The list also includes some publications authored by non-USGS cooperators with the WESPT, as well as some authored by USGS staff outside the WESPT in cooperation with WESPT projects. Several of the publications listed are available on the World Wide Web; for these, URL addresses are provided. Many of these web publications are USGS Open-File reports that contain large digital databases of geologic map and related information. Information on ordering USGS publications can be found on the World Wide Web at http://www.usgs.gov/pubprod/, or by calling 1-888-ASK-USGS. The U.S. Geological Survey's web

  4. Publications of Western Earth Surface Processes Team 2001

    Science.gov (United States)

    Powell, II; Graymer, R.W.

    2002-01-01

    The Western Earth Surface Processes Team (WESPT) of the U.S. Geological Survey (USGS) conducts geologic mapping and related topical earth-science studies in the Western United States. This work is focused on areas where modern geologic maps and associated earth-science data are needed to address key societal and environmental issues, such as ground-water quality, landslides and other potential geologic hazards, and land-use decisions. Areas of primary emphasis in 2001 included southern California, the San Francisco Bay region, the Pacific Northwest, and the Las Vegas urban corridor. The team has its headquarters in Menlo Park, California, and maintains smaller field offices at several other locations in the Western United States. The results of research conducted by the WESPT are released to the public as a variety of databases, maps, text reports, and abstracts, both through the internal publication system of the USGS and in diverse external publications such as scientific journals and books. This report lists publications of the WESPT released in 2001, as well as additional 1999 and 2000 publications that were not included in the previous list (USGS Open-File Report 00–215 and USGS Open-File Report 01–198). Most of the publications listed were authored or coauthored by WESPT staff. The list also includes some publications authored by non-USGS cooperators with the WESPT, as well as some authored by USGS staff outside the WESPT in cooperation with WESPT projects. Several of the publications listed are available on the World Wide Web; for these, URL addresses are provided. Many of these web publications are USGS Open-File Reports that contain large digital databases of geologic map and related information.

  5. Publications of the Western Earth Surface Processes Team 2000

    Science.gov (United States)

    Powell, Charles L.; Stone, Paul

    2001-01-01

    The Western Earth Surface Processes Team (WESP) of the U.S. Geological Survey (USGS) conducts geologic mapping and related topical earth science studies in the western United States. This work is focused on areas where modern geologic maps and associated earth-science data are needed to address key societal and environmental issues such as ground-water quality, potential geologic hazards, and land-use decisions. Areas of primary emphasis in 2000 included southern California, the San Francisco Bay region, the Pacific Northwest, the Las Vegas urban corridor, and selected National Park lands. The team has its headquarters in Menlo Park, California, and maintains smaller field offices at several other locations in the western United States. The results of research conducted by the WESPT are released to the public as a variety of databases, maps, text reports, and abstracts, both through the internal publication system of the USGS and in diverse external publications such as scientific journals and books. This report lists publications of the WESPT released in 2000 as well as additional 1999 publications that were not included in the previous list (USGS Open-file Report 00-215). Most of the publications listed were authored or coauthored by WESPT staff. The list also includes some publications authored by non-USGS cooperators with the WESPT, as well as some authored by USGS staff outside the WESPT in cooperation with WESPT projects. Several of the publications listed are available on the World Wide Web; for these, URL addresses are provided. Many of these Web publications are USGS open-file reports that contain large digital databases of geologic map and related information.

  6. Publications of the Western Earth Surface Processes Team 2002

    Science.gov (United States)

    Powell, Charles; Graymer, R.W.

    2003-01-01

    The Western Earth Surface Processes Team (WESPT) of the U.S. Geological Survey (USGS) conducts geologic mapping and related topical earth science studies in the western United States. This work is focused on areas where modern geologic maps and associated earth-science data are needed to address key societal and environmental issues such as ground-water quality, landslides and other potential geologic hazards, and land-use decisions. Areas of primary emphasis in 2001 included southern California, the San Francisco Bay region, the Pacific Northwest, and the Las Vegas urban corridor. The team has its headquarters in Menlo Park, California, and maintains smaller field offices at several other locations in the western United States. The results of research conducted by the WESPT are released to the public as a variety of databases, maps, text reports, and abstracts, both through the internal publication system of the USGS and in diverse external publications such as scientific journals and books. This report lists publications of the WESPT released in 2002 as well as additional 1998 and 2001 publications that were not included in the previous list (USGS Open-File Report 00-215, USGS Open-File Report 01-198, and USGS Open-File Report 02-269). Most of the publications listed were authored or coauthored by WESPT staff. The list also includes some publications authored by non-USGS cooperators with the WESPT, as well as some authored by USGS staff outside the WESPT in cooperation with WESPT projects. Several of the publications listed are available on the World Wide Web; for these, URL addresses are provided. Many of these web publications are USGS open-file reports that contain large digital databases of geologic map and related information. Information on ordering USGS publications can be found on the World Wide Web or by calling 1-888-ASK-USGS. The U.S. Geological Survey’s web server for geologic information in the western United States is located at http

  7. Coupled Deep Earth and surface processes and their impact on geohazards

    NARCIS (Netherlands)

    Cloetingh, S.; Tibaldi, A.; Burov, E.

    2012-01-01

    Better understanding of coupled Deep Earth and surface processes is the key for resolving the evolution of the continental lithosphere and its surface topography. The thermo-mechanical structure of the lithosphere exerts a prime control on the interaction of mantle instabilities and tectonic forces

  8. Interactive Computing and Processing of NASA Land Surface Observations Using Google Earth Engine

    Science.gov (United States)

    Molthan, Andrew; Burks, Jason; Bell, Jordan

    2016-01-01

    Google's Earth Engine offers a "big data" approach to processing large volumes of NASA and other remote sensing products. h\\ps://earthengine.google.com/ Interfaces include a Javascript or Python-based API, useful for accessing and processing over large periods of record for Landsat and MODIS observations. Other data sets are frequently added, including weather and climate model data sets, etc. Demonstrations here focus on exploratory efforts to perform land surface change detection related to severe weather, and other disaster events.

  9. EarthShape: A Strategy for Investigating the Role of Biota on Surface Processes

    Science.gov (United States)

    Übernickel, Kirstin; Ehlers, Todd Alan; von Blanckenburg, Friedhelm; Paulino, Leandro

    2017-04-01

    EarthShape - "Earth surface shaping by biota" is a 6-year priority research program funded by the German science foundation (DFG-SPP 1803) that performs soil- and landscape-scale critical zone research at 4 locations along a climate gradient in Chile, South America. The program is in its first year and involves an interdisciplinary collaboration between geologists, geomorphologists, ecologists, soil scientists, microbiologists, geophysicists, geochemists, hydrogeologists and climatologists including 18 German and 8 Chilean institutions. EarthShape is composed of 4 research clusters representing the process chain from weathering of substrate to deposition of eroded material. Cluster 1 explores micro-biota as the "weathering engine". Investigations in this cluster quantify different mechanisms of biogenic weathering whereby plants, fungi, and bacteria interact with rock in the production of soil. Cluster 2 explores bio-mediated redistribution of material within the weathering zone. Studies in this cluster focus on soil catenas along hill slope profiles to investigate the modification of matter along its transport path. Cluster 3 explores biotic modulation of erosion and sediment routing at the catchment scale. Investigations in this cluster explore the effects of vegetation cover on solute and sediment transport from hill slopes to the channel network. Cluster 4 explores the depositional legacy of coupled biogenic and Earth surface systems. This cluster investigates records of vegetation-land surface interactions in different depositional settings. A final component of EarthShape lies in the integration of results from these 4 clusters using numerical models to bridging between the diverse times scales used by different disciplines. The Chilean Coastal Cordillera between 25° and 40°S was selected to carry out this research because its north-south orientation captures a large ecological and climate gradient. This gradient ranges from hyper-arid (Atacama desert) to

  10. Geomorphological experiments for understanding cross-scale complexity of earth surface processes

    Science.gov (United States)

    Seeger, Manuel

    2016-04-01

    The shape of the earth's surface is the result of a complex interaction of different processes at different spatial and temporal scales. The challenging problem is, that process observation is rarely possible due to this different scales. In addition, the resulting landform often does not match the scale of process observation. But it is indispensable for the development of concepts of formation of landforms to identify and understand the involved processes and their interaction. To develop models it is even necessary to quantify them and their relevant parameters. Experiments are able to bridge the constraints of process observation mentioned above: it is possible to observe and quantify individual processes as well as complex process combinations up to the development of geomorphological units. The contribution aims at showing, based on soil erosion research, the possibilities of experimental methods for contributing to th understanding of geomorphological processes. A special emphasis is put on the linkage of conceptual understanding of processes, their measurement and the following development of models. The development of experiments to quantify relevant parameters will be shown, as well as the steps undertaken to bring them into the field taking into account the resulting increase of uncertainty in system parameters and results. It will be shown that experiments are even so able to produce precise measurements on individual processes as well as of complex combinations of parameters and processes and to identify their influence on the overall geomorphological dynamics. Experiments are therefore a methodological package able to check complex soil erosion processes at different levels of conceptualization and to generate data for their quantification. And thus, also a methodological concept to take more into account and to further develop in geomorphological science.

  11. Monitoring perturbations of earth surface process after the 2015 Gorkha earthquake in Nepal

    Science.gov (United States)

    Andermann, Christoff; Hovius, Niels; Cook, Kristen; Turowski, Jens; Illien, Luc; Sense-Schönfelder, Christoph; Rössner, Sigrid; Parajuli, Binod; Bajracharya, Krishna; Adi=hikari, Basanta

    2017-04-01

    Large earthquakes can substantially perturb a wide range of Earth surface processes. The strong shaking caused by large earthquakes weakens rockmass, causes extensive landsliding, and alter the hydrological conductivity of the near surface. This leads to subsequent responses that include sediment loading of rivers and changes in subsurface water flow paths. The long term perturbation often last several years and even might outstrip the immediate co-seismic impact in their magnitude. Over time the system restores to background conditions, and the recovery process and transient timescales of different systems provide particularly valuable insights for predicting natural risks associated with the aftermath of earthquakes. Here we will present results of the first 2 years of monitoring surface processes in the epicentral area of the 2015 Gorkha earthquake. The observations started immediately after the event and are planned to continue for a total of four monsoon seasons, in order to capture the full recovery process of the system until pre-earthquake conditions have been reached. We have installed a comprehensive network of twelve river sampling stations for daily water and sediment sampling, covering all major rivers draining the earthquake-affected areas. Nested within this regional network, we have installed an array of 16 seismometers and 6 weather stations in the upper Bhotekoshi catchment. The field measurements are accompanied by repeated mapping of landslide activities using satellite imagery. Our results show pronounced changes of the hydrological regime, underpinned by a marked change of seismic noise velocities, both indications of significant changes of the subsurface rock properties. Alongside, our landslide mapping documents about ten times greater landslide activity during the 2015 monsoon season than typically expected for this monsoon season. Very preliminary estimates for the exceptionally strong 2016 monsoon season are also elevated. This

  12. Environmental seismology: What can we learn on earth surface processes with ambient noise?

    Science.gov (United States)

    Larose, Eric; Carrière, Simon; Voisin, Christophe; Bottelin, Pierre; Baillet, Laurent; Guéguen, Philippe; Walter, Fabian; Jongmans, Denis; Guillier, Bertrand; Garambois, Stéphane; Gimbert, Florent; Massey, Chris

    2015-05-01

    Environmental seismology consists in studying the mechanical vibrations that originate from, or that have been affected by external causes, that is to say causes outside the solid Earth. This includes for instance the coupling between the solid Earth and the cryosphere, or the hydrosphere, the anthroposphere and the specific sources of vibration developing there. Environmental seismology also addresses the modifications of the wave propagation due to environmental forcing such as temperature and hydrology. Recent developments in data processing, together with increasing computational power and sensor concentration have led to original observations that allow for the development of this new field of seismology. In this article, we will particularly review how we can track and interpret tiny changes in the subsurface of the Earth related to external changes from modifications of the seismic wave propagation, with application to geomechanics, hydrology, and natural hazard. We will particularly demonstrate that, using ambient noise, we can track 1) thermal variations in the subsoil, in buildings or in rock columns; 2) the temporal and spatial evolution of a water table; 3) the evolution of the rigidity of the soil constituting a landslide, and especially the drop of rigidity preceding a failure event.

  13. Earth's surface heat flux

    Directory of Open Access Journals (Sweden)

    J. H. Davies

    2010-02-01

    Full Text Available We present a revised estimate of Earth's surface heat flux that is based upon a heat flow data-set with 38 347 measurements, which is 55% more than used in previous estimates. Our methodology, like others, accounts for hydrothermal circulation in young oceanic crust by utilising a half-space cooling approximation. For the rest of Earth's surface, we estimate the average heat flow for different geologic domains as defined by global digital geology maps; and then produce the global estimate by multiplying it by the total global area of that geologic domain. The averaging is done on a polygon set which results from an intersection of a 1 degree equal area grid with the original geology polygons; this minimises the adverse influence of clustering. These operations and estimates are derived accurately using methodologies from Geographical Information Science. We consider the virtually un-sampled Antarctica separately and also make a small correction for hot-spots in young oceanic lithosphere. A range of analyses is presented. These, combined with statistical estimates of the error, provide a measure of robustness. Our final preferred estimate is 47±2 TW, which is greater than previous estimates.

  14. Mirador - Earth Surface and Interior

    Data.gov (United States)

    National Aeronautics and Space Administration — Earth Science data access made simple. The goal of the Earth Surface and Interior focus area is to assess, mitigate and forecast the natural hazards that affect...

  15. Mathematic modeling of the Earth's surface and the process of remote sensing

    Science.gov (United States)

    Balter, B. M.

    1979-01-01

    It is shown that real data from remote sensing of the Earth from outer space are not best suited to the search for optimal procedures with which to process such data. To work out the procedures, it was proposed that data synthesized with the help of mathematical modeling be used. A criterion for simularity to reality was formulated. The basic principles for constructing methods for modeling the data from remote sensing are recommended. A concrete method is formulated for modeling a complete cycle of radiation transformations in remote sensing. A computer program is described which realizes the proposed method. Some results from calculations are presented which show that the method satisfies the requirements imposed on it.

  16. The PROCESS experiment: amino and carboxylic acids under Mars-like surface UV radiation conditions in low-earth orbit.

    Science.gov (United States)

    Noblet, Audrey; Stalport, Fabien; Guan, Yuan Yong; Poch, Olivier; Coll, Patrice; Szopa, Cyril; Cloix, Mégane; Macari, Frédérique; Raulin, Francois; Chaput, Didier; Cottin, Hervé

    2012-05-01

    The search for organic molecules at the surface of Mars is a top priority of the next Mars exploration space missions: Mars Science Laboratory (NASA) and ExoMars (ESA). The detection of organic matter could provide information about the presence of a prebiotic chemistry or even biological activity on this planet. Therefore, a key step in interpretation of future data collected by these missions is to understand the preservation of organic matter in the martian environment. Several laboratory experiments have been devoted to quantifying and qualifying the evolution of organic molecules under simulated environmental conditions of Mars. However, these laboratory simulations are limited, and one major constraint is the reproduction of the UV spectrum that reaches the surface of Mars. As part of the PROCESS experiment of the European EXPOSE-E mission on board the International Space Station, a study was performed on the photodegradation of organics under filtered extraterrestrial solar electromagnetic radiation that mimics Mars-like surface UV radiation conditions. Glycine, serine, phthalic acid, phthalic acid in the presence of a mineral phase, and mellitic acid were exposed to these conditions for 1.5 years, and their evolution was determined by Fourier transform infrared spectroscopy after their retrieval. The results were compared with data from laboratory experiments. A 1.5-year exposure to Mars-like surface UV radiation conditions in space resulted in complete degradation of the organic compounds. Half-lives between 50 and 150 h for martian surface conditions were calculated from both laboratory and low-Earth orbit experiments. The results highlight that none of those organics are stable under low-Earth orbit solar UV radiation conditions.

  17. The TOPOMOD-ITN project: unravel the origin of Earth's topography from modelling deep-surface processes

    Science.gov (United States)

    Faccenna, C.; Funiciello, F.

    2012-04-01

    EC-Marie Curie Initial Training Networks (ITN) projects aim to improve the career perspectives of young generations of researchers. Institutions from both academic and industry sectors form a collaborative network to recruit research fellows and provide them with opportunities to undertake research in the context of a joint research training program. In this frame, TOPOMOD - one of the training activities of EPOS, the new-born European Research Infrastructure for Geosciences - is a funded ITN project designed to investigate and model how surface processes interact with crustal tectonics and mantle convection to originate and develop topography of the continents over a wide range of spatial and temporal scales. The multi-disciplinary approach combines geophysics, geochemistry, tectonics and structural geology with advanced geodynamic numerical/analog modelling. TOPOMOD involves 8 European research teams internationally recognized for their excellence in complementary fields of Earth Sciences (Roma TRE, Utrecht, GFZ, ETH, Cambridge, Durham, Rennes, Barcelona), to which are associated 5 research institutions (CNR-Italy, Univ. Parma, Univ. Lausanne, Univ. Montpellier, Univ. Mainz) , 3 high-technology enterprises (Malvern Instruments, TNO, G.O. Logical Consulting) and 1 large multinational oil and gas company (ENI). This unique network places emphasis in experience-based training increasing the impact and international visibility of European research in modeling. Long-term collaboration and synergy are established among the overmentioned research teams through 15 cross-disciplinary research projects that combine case studies in well-chosen target areas from the Mediterranean, the Middle and Far East, west Africa, and South America, with new developments in structural geology, geomorphology, seismology, geochemistry, InSAR, laboratory and numerical modelling of geological processes from the deep mantle to the surface. These multidisciplinary projects altogether aim to

  18. Unsupervised SBAS-DInSAR Processing of Space-borne SAR data for Earth Surface Displacement Time Series Generation

    Science.gov (United States)

    Casu, F.; de Luca, C.; Lanari, R.; Manunta, M.; Zinno, I.

    2016-12-01

    During the last 25 years, the Differential Synthetic Aperture Radar Interferometry (DInSAR) has played an important role for understanding the Earth's surface deformation and its dynamics. In particular, the large collections of SAR data acquired by a number of space-borne missions (ERS, ENVISAT, ALOS, RADARSAT, TerraSAR-X, COSMO-SkyMed) have pushed toward the development of advanced DInSAR techniques for monitoring the temporal evolution of the ground displacements with an high spatial density. Moreover, the advent of the Copernicus Sentinel-1 (S1) constellation is providing a further increase in the SAR data flow available to the Earth science community, due to its characteristics of global coverage strategy and free and open access data policy. Therefore, managing and storing such a huge amount of data, processing it in an effcient way and maximizing the available archives exploitation are becoming high priority issues. In this work we present some recent advances in the DInSAR field for dealing with the effective exploitation of the present and future SAR data archives. In particular, an efficient parallel SBAS implementation (namely P-SBAS) that takes benefit from high performance computing is proposed. Then, the P-SBAS migration to the emerging Cloud Computing paradigm is shown, together with extensive tests carried out in the Amazon's Elastic Cloud Compute (EC2) infrastructure. Finally, the integration of the P-SBAS processing chain within the ESA Geohazards Exploitation Platform (GEP), for setting up operational on-demand and systematic web tools, open to every user, aimed at automatically processing stacks of SAR data for the generation of SBAS displacement time series, is also illustrated. A number of experimental results obtained by using the ERS, ENVISAT and S1 data in areas characterized by volcanic, seismic and anthropogenic phenomena will be shown. This work is partially supported by: the DPC-CNR agreement, the EPOS-IP project and the ESA GEP project.

  19. Understanding Geomorphological Processes on the Earth's Surface from Laboratory Experiments and the Role of Communities of Practice in Generating Reusable Data

    Science.gov (United States)

    Hsu, L.

    2016-12-01

    Geomorphological processes move masses of sediment across the face of the Earth, from mountain tops to hillslopes, rivers, flood plains, and coastlines, on a range of temporal and spatial scales that span many orders of magnitude. These processes, sometimes spanning millennia and sometimes occurring catastrophically, affect human communities that live on and near these surface landforms. Experiments conveniently scale these processes to time and space that can be observed and measured in the laboratory. As a result, the research community has produced remarkable experimental datasets for processes such as particle transport, hillslope erosion, channel migration, and coastline evolution. These datasets build a collection that quantifies a wide range of environmental processes and contributes to hazards mitigation and the understanding of long-term effects of climate and tectonics on landscape evolution. However, technology and data acquisition rates are outgrowing capabilities for storing, maintaining, and serving the data. Solutions that improve preservation, reuse, and attribution of geomorphological data from unique experimental set-ups are germinating at different research centers. These solutions allow the cross-disciplinary data integration that is often necessary to achieving a mechanistic and holistic understanding of the processes that shape the Earth's surface. Communities of practice such as the Sediment Experimentalist Network (SEN) and the U.S. Geological Survey's Community for Data Integration (USGS CDI) play a critical role in effectively facilitating information exchange about tools, methods, and results that accelerate experimental success. Through community interactions and a culture change to generate data more fit for reuse, broad challenges in reproducibility, scaling, and integration may be addressed, leading to more rapid progress in Earth surface process research.

  20. The Landscape Evolution Observatory: A large-scale controllable infrastructure to study coupled Earth-surface processes

    Science.gov (United States)

    Pangle, Luke A.; DeLong, Stephen B.; Abramson, Nate; Adams, John; Barron-Gafford, Greg A.; Breshears, David D.; Brooks, Paul D.; Chorover, Jon; Dietrich, William E.; Dontsova, Katerina; Durcik, Matej; Espeleta, Javier; Ferre, T. P. A.; Ferriere, Regis; Henderson, Whitney; Hunt, Edward A.; Huxman, Travis E.; Millar, David; Murphy, Brendan; Niu, Guo-Yue; Pavao-Zuckerman, Mitch; Pelletier, Jon D.; Rasmussen, Craig; Ruiz, Joaquin; Saleska, Scott; Schaap, Marcel; Sibayan, Michael; Troch, Peter A.; Tuller, Markus; van Haren, Joost; Zeng, Xubin

    2015-09-01

    Zero-order drainage basins, and their constituent hillslopes, are the fundamental geomorphic unit comprising much of Earth's uplands. The convergent topography of these landscapes generates spatially variable substrate and moisture content, facilitating biological diversity and influencing how the landscape filters precipitation and sequesters atmospheric carbon dioxide. In light of these significant ecosystem services, refining our understanding of how these functions are affected by landscape evolution, weather variability, and long-term climate change is imperative. In this paper we introduce the Landscape Evolution Observatory (LEO): a large-scale controllable infrastructure consisting of three replicated artificial landscapes (each 330 m2 surface area) within the climate-controlled Biosphere 2 facility in Arizona, USA. At LEO, experimental manipulation of rainfall, air temperature, relative humidity, and wind speed are possible at unprecedented scale. The Landscape Evolution Observatory was designed as a community resource to advance understanding of how topography, physical and chemical properties of soil, and biological communities coevolve, and how this coevolution affects water, carbon, and energy cycles at multiple spatial scales. With well-defined boundary conditions and an extensive network of sensors and samplers, LEO enables an iterative scientific approach that includes numerical model development and virtual experimentation, physical experimentation, data analysis, and model refinement. We plan to engage the broader scientific community through public dissemination of data from LEO, collaborative experimental design, and community-based model development.

  1. The Landscape Evolution Observatory: a large-scale controllable infrastructure to study coupled Earth-surface processes

    Science.gov (United States)

    Pangle, Luke A.; DeLong, Stephen B.; Abramson, Nate; Adams, John; Barron-Gafford, Greg A.; Breshears, David D.; Brooks, Paul D.; Chorover, Jon; Dietrich, William E.; Dontsova, Katerina; Durcik, Matej; Espeleta, Javier; Ferre, T. P. A.; Ferriere, Regis; Henderson, Whitney; Hunt, Edward A.; Huxman, Travis E.; Millar, David; Murphy, Brendan; Niu, Guo-Yue; Pavao-Zuckerman, Mitch; Pelletier, Jon D.; Rasmussen, Craig; Ruiz, Joaquin; Saleska, Scott; Schaap, Marcel; Sibayan, Michael; Troch, Peter A.; Tuller, Markus; van Haren, Joost; Zeng, Xubin

    2015-01-01

    Zero-order drainage basins, and their constituent hillslopes, are the fundamental geomorphic unit comprising much of Earth's uplands. The convergent topography of these landscapes generates spatially variable substrate and moisture content, facilitating biological diversity and influencing how the landscape filters precipitation and sequesters atmospheric carbon dioxide. In light of these significant ecosystem services, refining our understanding of how these functions are affected by landscape evolution, weather variability, and long-term climate change is imperative. In this paper we introduce the Landscape Evolution Observatory (LEO): a large-scale controllable infrastructure consisting of three replicated artificial landscapes (each 330 m2 surface area) within the climate-controlled Biosphere 2 facility in Arizona, USA. At LEO, experimental manipulation of rainfall, air temperature, relative humidity, and wind speed are possible at unprecedented scale. The Landscape Evolution Observatory was designed as a community resource to advance understanding of how topography, physical and chemical properties of soil, and biological communities coevolve, and how this coevolution affects water, carbon, and energy cycles at multiple spatial scales. With well-defined boundary conditions and an extensive network of sensors and samplers, LEO enables an iterative scientific approach that includes numerical model development and virtual experimentation, physical experimentation, data analysis, and model refinement. We plan to engage the broader scientific community through public dissemination of data from LEO, collaborative experimental design, and community-based model development.

  2. Coherent flow structures at earth's surface

    National Research Council Canada - National Science Library

    Venditti, J.G; Best, J.L; Church, M; Hardy, R.J

    2013-01-01

    This book reviews the recent progress in the study of the turbulent flows that sculpt the Earth's surface, focusing in particular on the organized structures that have been identified in recent years...

  3. Role of tectonomagmatic processes for surface environmental changes and evolution of biosphere on terrestrial planets: Evidence for evolution of the life on the Earth

    Science.gov (United States)

    Sharkov, Evgenii; Bogina, Maria

    atmospheric circulation. All these processes finally led to the global glaciations. The latters commenced earlier, in the Paleoproterozoic, simultaneously with first manifestations of Fe-Ti basaltic magmatism, which came into force only in the middle Paleoproterozoic. Thus, a fundamental change in tectonomagmatic activity acted as the trigger for environmental changes and biospheric evolution, supplying a qualitatively new material on the Earth's surface. Data available on Venus and Mars suggest that their tectonomagmatic evolution also occurred at the close scenario. Two major types of morphostructures, which are vast plains, composed by young basaltic flows, and older lightweight uplifted segments with a complicated topography (tesseras on the Venus and earths (terras) on the Mars), can evidence about two-stage evolution of these planets. Presence of drainage systems on Mars and valles on Venus assumes existence of liquid water on early stages of their development. Like on the Earth, red beds and global glacials appeared on the Mars at the middle stage of it's evolu-tion, and may be at this period ancient microorganisms existed on Mars (McKay et al., 1996). Powerful eruptions of gigantic volcanoes of Tharsis and Elysium, probably, led to fall of tem-perature and disappearance of liquid water on Mars. In contrast to Mars, on Venus appeared speeded up greenhouse effect, which also led to dry and very hot surface. So, development of tectonomagmatic processes was favourable for the biosphere evolution only on the Earth.

  4. Surface Disturbance Analysis in Rare Earth Mining

    Science.gov (United States)

    Li, H. K.; Yang, L.; Liu, Z. W.

    2017-02-01

    Mining ion-type rare-earth ore made the landscape and ecological environment degraded in mining area, and the tailing produced by rare-earth mining also led large areas land desertification, which resulted in surface temperature variations and significant differences in other types of mining disturbances. In order to analyse surface disturbance of rare-earth mining area, this paper applied the methods based on Normalized Difference Vegetation Index (NDVI) and Temperature different Coefficient (TDC) as the ecological disturbance indicator, compared and validated their applicability in Lingbei rare-earth mining area of Southern China. The results illustrated that, compared to NDVI, the TDC which reflected the characteristic of rare-earth mining technology has better discrimination of disturbance, especially for in-situ leach mining area. The places of tailing and the in-situ leach mining plants were the most dramatic mining disturbance. They had the biggest TDC value, followed by orchards and farmlands, reclamation plants, they had relatively small disturbance. And the last was the plant with the smallest TDC value. TDC in rare-earth mining could better correspond to the level of surface ecological disturbance. Therefore, TDC as the indicator of ecological disturbance factor had better performance than NDVI in rare-earth mining area.

  5. The energy balance of the earth's surface : a practical approach

    NARCIS (Netherlands)

    Bruin, de H.A.R.

    1982-01-01

    This study is devoted to the energy balance of the earth's surface with a special emphasis on practical applications. A simple picture of the energy exchange processes that take place at the ground is the following. Per unit time and area an amount of radiant energy is supplied to the surface. This

  6. Physical Processes Controlling Earth's Climate

    Science.gov (United States)

    Genio, Anthony Del

    2013-01-01

    As background for consideration of the climates of the other terrestrial planets in our solar system and the potential habitability of rocky exoplanets, we discuss the basic physics that controls the Earths present climate, with particular emphasis on the energy and water cycles. We define several dimensionless parameters relevant to characterizing a planets general circulation, climate and hydrological cycle. We also consider issues associated with the use of past climate variations as indicators of future anthropogenically forced climate change, and recent advances in understanding projections of future climate that might have implications for Earth-like exoplanets.

  7. Earthing the Human Body Influences Physiologic Processes

    Science.gov (United States)

    Sokal, Karol

    2011-01-01

    Abstract Objectives This study was designed to answer the question: Does the contact of the human organism with the Earth via a copper conductor affect physiologic processes? Subjects and experiments Five (5) experiments are presented: experiment 1—effect of earthing on calcium–phosphate homeostasis and serum concentrations of iron (N = 84 participants); experiment 2—effect of earthing on serum concentrations of electrolytes (N = 28); experiment 3—effect of earthing on thyroid function (N = 12); experiment 4—effect of earthing on glucose concentration (N = 12); experiment 5—effect of earthing on immune response to vaccine (N = 32). Subjects were divided into two groups. One (1) group of people was earthed, while the second group remained without contact with the Earth. Blood and urine samples were examined. Results Earthing of an electrically insulated human organism during night rest causes lowering of serum concentrations of iron, ionized calcium, inorganic phosphorus, and reduction of renal excretion of calcium and phosphorus. Earthing during night rest decreases free tri-iodothyronine and increases free thyroxine and thyroid-stimulating hormone. The continuous earthing of the human body decreases blood glucose in patients with diabetes. Earthing decreases sodium, potassium, magnesium, iron, total protein, and albumin concentrations while the levels of transferrin, ferritin, and globulins α1, α2, β, and γ increase. These results are statistically significant. Conclusions Earthing the human body influences human physiologic processes. This influence is observed during night relaxation and during physical activity. Effect of the earthing on calcium–phosphate homeostasis is the opposite of that which occurs in states of weightlessness. It also increases the activity of catabolic processes. It may be the primary factor regulating endocrine and nervous systems. PMID:21469913

  8. Earthing the human body influences physiologic processes.

    Science.gov (United States)

    Sokal, Karol; Sokal, Pawel

    2011-04-01

    This study was designed to answer the question: Does the contact of the human organism with the Earth via a copper conductor affect physiologic processes? Subjects and experiments: Five (5) experiments are presented: experiment 1-effect of earthing on calcium-phosphate homeostasis and serum concentrations of iron (N = 84 participants); experiment 2-effect of earthing on serum concentrations of electrolytes (N = 28); experiment 3-effect of earthing on thyroid function (N = 12); experiment 4-effect of earthing on glucose concentration (N = 12); experiment 5-effect of earthing on immune response to vaccine (N = 32). Subjects were divided into two groups. One (1) group of people was earthed, while the second group remained without contact with the Earth. Blood and urine samples were examined. Earthing of an electrically insulated human organism during night rest causes lowering of serum concentrations of iron, ionized calcium, inorganic phosphorus, and reduction of renal excretion of calcium and phosphorus. Earthing during night rest decreases free tri-iodothyronine and increases free thyroxine and thyroid-stimulating hormone. The continuous earthing of the human body decreases blood glucose in patients with diabetes. Earthing decreases sodium, potassium, magnesium, iron, total protein, and albumin concentrations while the levels of transferrin, ferritin, and globulins α1, α2, β, and γ increase. These results are statistically significant. Earthing the human body influences human physiologic processes. This influence is observed during night relaxation and during physical activity. Effect of the earthing on calcium-phosphate homeostasis is the opposite of that which occurs in states of weightlessness. It also increases the activity of catabolic processes. It may be the primary factor regulating endocrine and nervous systems.

  9. The Earth surface slide movement at Soledad

    Science.gov (United States)

    Moreno, A.

    1986-11-01

    The Earth surface slide movement at Soledad is a mountain-slide type of movement. Estimations of the thickness of the layer which is moving range between 10 and 100 m. There is no proof that the movement is water induced, but it could be influenced by the water household. The slope of the slide area is H: D = 1: 2. The height difference in the moving area studied, according to this paper, is 1 km. The actual rate of movement is about 12 cm/yr.

  10. Earth Surface Patterns in 200 Years (Invited)

    Science.gov (United States)

    Werner, B.

    2009-12-01

    What kinds of patterns will characterize Earth's surface in 200 years? This question is addressed using a complex systems dynamical framework for distinct levels of description in a hierarchy, in which time scale and spatial extent increase and number of variables decrease with level, and in which levels are connected nonlinearly to each other via self-organization and slaving and linearly to the external environment. Self-organized patterns linking the present to 200 years in the future must be described dynamically on a level with a time scale of centuries. Human-landscape coupling will play a prominent role in the formation of these patterns as population peaks and interactions become nonlinear over these time scales. Three related examples illustrate this approach. First, the response of human-occupied coastlines to rising sea level. Coastlines in wealthy regions develop a spatially varying boom and bust pattern, with response amplified by structures meant to delay the effects of sea level rise. Coastlines in economically disadvantaged regions experience a subdued response, with populations developing a culture of displacement that minimizes human-landscape interactions in a context of scarce resources. Second, the evolution of nation-state borders with degrading ecosystems, declining resource availability and increasing transportation costs. The maintenance of strong borders as selective filtration systems (goods, capital and people) is based on a cost-benefit analysis in which the economic benefits accruing from long distance, globalized resource exploitation are weighed against policing and infrastructure costs. As costs rise above benefits, borders fragment, with a transition to local barriers and conflicts, and mobile peoples moving to resources. Third, trends in urbanization and development of megacities under economic and environmental stress. The pattern of rapid growth of megacities through inward migration, with displaced people occupying high

  11. Rare earth silicide nanowires on silicon surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Wanke, Martina

    2008-11-10

    The growth, structure and electronic properties of rare earth silicide nanowires are investigated on planar and vicinal Si(001) und Si(111) surfaces with scanning tunneling microscopy (STM), low energy electron diffraction (LEED) and angle-resolved photoelectron spectroscopy (ARPES). On all surfaces investigated within this work hexagonal disilicides are grown epitaxially with a lattice mismatch of -2.55% up to +0.83% along the hexagonal a-axis. Along the hexagonal c-axis the lattice mismatch is essentially larger with 6.5%. On the Si(001)2 x 1 surface two types of nanowires are grown epitaxially. The socalled broad wires show a one-dimensional metallic valence band structure with states crossing the Fermi level. Along the nanowires two strongly dispersing states at the anti J point and a strongly dispersing state at the anti {gamma} point can be observed. Along the thin nanowires dispersing states could not be observed. Merely in the direction perpendicular to the wires an intensity variation could be observed, which corresponds to the observed spacial structure of the thin nanowires. The electronic properties of the broad erbium silicide nanowires are very similar to the broad dysprosium silicide nanowires. The electronic properties of the DySi{sub 2}-monolayer and the Dy{sub 3}Si{sub 5}-multilayer on the Si(111) surface are investigated in comparison to the known ErSi{sub 2}/Si(111) and Er{sub 3}Si{sub 5}/Si(111) system. The positions and the energetic locations of the observed band in the surface Brillouin zone will be confirmed for dysprosium. The shape of the electron pockets in the (vector)k {sub parallel} space is elliptical at the anti M points, while the hole pocket at the anti {gamma} point is showing a hexagonal symmetry. On the Si(557) surface the structural and electronic properties depend strongly on the different preparation conditions likewise, in particular on the rare earth coverage. At submonolayer coverage the thin nanowires grow in wide areas

  12. Earth encounters as the origin of fresh surfaces on near-Earth asteroids.

    Science.gov (United States)

    Binzel, Richard P; Morbidelli, Alessandro; Merouane, Sihane; Demeo, Francesca E; Birlan, Mirel; Vernazza, Pierre; Thomas, Cristina A; Rivkin, Andrew S; Bus, Schelte J; Tokunaga, Alan T

    2010-01-21

    Telescopic measurements of asteroids' colours rarely match laboratory reflectance spectra of meteorites owing to a 'space weathering' process that rapidly reddens asteroid surfaces in less than 10(6) years. 'Unweathered' asteroids (those having spectra matching the most commonly falling ordinary chondrite meteorites), however, are seen among small bodies the orbits of which cross inside Mars and the Earth. Various explanations have been proposed for the origin of these fresh surface colours, ranging from collisions to planetary encounters. Less reddened asteroids seem to cross most deeply into the terrestrial planet region, strengthening the evidence for the planetary-encounter theory, but encounter details within 10(6) years remain to be shown. Here we report that asteroids displaying unweathered spectra (so-called 'Q-types') have experienced orbital intersections closer than the Earth-Moon distance within the past 5 x 10(5) years. These Q-type asteroids are not currently found among asteroids showing no evidence of recent close planetary encounters. Our results substantiate previous work: tidal stress, strong enough to disturb and expose unweathered surface grains, is the most likely dominant short-term asteroid resurfacing process. Although the seismology details are yet to be worked out, the identification of rapid physical processes that can produce both fresh and weathered asteroid surfaces resolves the decades-long puzzle of the difference in colour of asteroids and meteorites.

  13. Influence of slip-surface geometry on earth-flow deformation, Montaguto earth flow, southern Italy

    Science.gov (United States)

    Guerriero, L.; Coe, Jeffrey A.; Revellio, P.; Grelle, G.; Pinto, F.; Guadagno, F.

    2016-01-01

    We investigated relations between slip-surface geometry and deformational structures and hydrologic features at the Montaguto earth flow in southern Italy between 1954 and 2010. We used 25 boreholes, 15 static cone-penetration tests, and 22 shallow-seismic profiles to define the geometry of basal- and lateral-slip surfaces; and 9 multitemporal maps to quantify the spatial and temporal distribution of normal faults, thrust faults, back-tilted surfaces, strike-slip faults, flank ridges, folds, ponds, and springs. We infer that the slip surface is a repeating series of steeply sloping surfaces (risers) and gently sloping surfaces (treads). Stretching of earth-flow material created normal faults at risers, and shortening of earth-flow material created thrust faults, back-tilted surfaces, and ponds at treads. Individual pairs of risers and treads formed quasi-discrete kinematic zones within the earth flow that operated in unison to transmit pulses of sediment along the length of the flow. The locations of strike-slip faults, flank ridges, and folds were not controlled by basal-slip surface topography but were instead dependent on earth-flow volume and lateral changes in the direction of the earth-flow travel path. The earth-flow travel path was strongly influenced by inactive earth-flow deposits and pre-earth-flow drainages whose positions were determined by tectonic structures. The implications of our results that may be applicable to other earth flows are that structures with strikes normal to the direction of earth-flow motion (e.g., normal faults and thrust faults) can be used as a guide to the geometry of basal-slip surfaces, but that depths to the slip surface (i.e., the thickness of an earth flow) will vary as sediment pulses are transmitted through a flow.

  14. NASA's Earth Science Data Systems Standards Process

    Science.gov (United States)

    Enloe, Y.; Ullman, R.

    2007-12-01

    The purpose of NASA's Standards Process Group (SPG) is to provide recommendations to NASA management on ways to evolve and improve Earth Data Systems through the endorsement of Earth science data systems standards. SPG's goal is to facilitate broader use of standards that have proven implementation and operational benefit to NASA Earth science by facilitating the approval of proposed standards and directing the evolution of standards. We have found that the candidate standards that self defined communities are proposing for endorsement to the SPG are one of 4 types: (1) A NASA community developed standard used within at least one self defined community where the proposed standard has not been approved or adopted by an external standards organization and where new implementations are expected to be developed from scratch, using the proposed standard as the implementation specification; (2) A NASA community developed standard used within at least one self defined community where the proposed standard has not been approved or adopted by an external standards organization and where new implementations are not expected to be developed from scratch but use existing software libraries or code;. (3) A standard already approved by an external standards organization but is being proposed for use for the NASA Earth science community; (4) A defacto standard already widely used. SPG's standards process has been revised to provide a comprehensive but not a redundant review of the proposed standard. We will discuss real examples of the different types of candidate standards that have been proposed and endorsed (i.e. OPeNDAP's Data Access Protocol, Open Geospatial Consortium's Web Map Server, and the Hierarchical Data Format). We will discuss the potential defacto standards (Google's KML, Global Change Master Directory (GCMD) Directory Interchange Format (DIF), GeoTIFF file format) that could be identified and endorsed through our revised Standards Process in the future. We will

  15. The Contribution of GGOS to Understanding Dynamic Earth Processes

    Science.gov (United States)

    Gross, Richard

    2017-04-01

    of continental and basin-scale water masses; loading and unloading of the land surface due to seasonal changes of groundwater; measurement of water level of major lakes and rivers by satellite altimetry; and improved digital terrain models as basis for flux modeling of surface water and flood modeling. Geodesy is crucial for cryospheric studies because of its ability to measure the motions of ice masses and changes in their volumes. Ice sheets, glaciers, and sea ice are intricately linked to the Earth's climate system. They store a record of past climate; they strongly affect surface energy budget, global water cycle, and sea-level change; and they are sensitive indicators of climate change. Geodesy is at the heart of all present-day ocean studies. Geodetic observations uniquely produce accurate, quantitative, and integrated observations of gravity, ocean circulation, sea surface height, ocean bottom pressure, and mass exchanges among the ocean, cryosphere, and land. Geodetic observations have made fundamental contributions to monitoring and understanding physical ocean processes. In particular, geodesy is the basic technique used to determine an accurate geoid model, allowing for the determination of absolute surface geostrophic currents, which are necessary to quantify heat transport of the ocean. Geodesy also provides the absolute reference for tide gauge measurements, allowing those measurements to be merged with satellite altimetric measurements to provide a coherent worldwide monitoring system for sea level change. In this presentation, selected examples of the contribution of geodetic observations to understanding the dynamic Earth system will be presented.

  16. Strange Features of the Earth's Surface Explained: An Interactive Poster

    Science.gov (United States)

    Kellogg, J. B.; Becker, T. W.

    2004-12-01

    The great power of the plate tectonic theory lies in its ability to explain a large numer of diverse observations: the ocean-continental dichotemy, the major features of the sea floor topography, Wadati-Benioff zones, etc. A cursory examination of a physiographic map, however, reveals features that are not trivially explained by plate tectonics, e.g. the different radii of curvature of the island arcs and the bend in the Hawaiian-Emporer chain. This interactive poster aims to establish the current state of knowledge about the Earth's surface and the dynamic processes that control it. The poster itself consists simply of a map of the Earth, accompanied by two sets of Post-It notes. The first set are to be used by viewers to identify problematica for which they would like an explanation. The second set are to be used by others who believe they have explanations, and hopefully key references to support them. The follow-up to this poster will be a "clickable" online map comprising both the observations and their explanations. We hope that this will provide both educators and researchers with an accurate, up-to-date picture of our current state of understanding of the Earth's first-order features.

  17. Bacterial Cell Surface Adsorption of Rare Earth Elements

    Science.gov (United States)

    Jiao, Y.; Park, D.; Reed, D.; Fujita, Y.; Yung, M.; Anderko, A.; Eslamimanesh, A.

    2015-12-01

    Rare earth elements (REE) play a critical role in many emerging clean energy technologies, including high-power magnets, wind turbines, solar panels, hybrid/electric vehicle batteries and lamp phosphors. In order to sustain demand for such technologies given current domestic REE shortages, there is a need to develop new approaches for ore processing/refining and recycling of REE-containing materials. To this end, we have developed a microbially-mediated bioadsorption strategy with application towards enrichment of REE from complex mixtures. Specifically, the bacterium Caulobacter crescentus was genetically engineered to display lanthanide binding tags (LBTs), short peptides that possess high affinity and specificity for rare earth elements, on its cell surface S-layer protein. Under optimal conditions, LBT-displayed cells adsorbed greater than 5-fold more REE than control cells lacking LBTs. Competition binding experiments with a selection of REEs demonstrated that our engineered cells could facilitate separation of light- from heavy- REE. Importantly, binding of REE onto our engineered strains was much more favorable compared to non-REE metals. Finally, REE bound to the cell surface could be stripped off using citrate, providing an effective and non-toxic REE recovery method. Together, this data highlights the potential of our approach for selective REE enrichment from REE containing mixtures.

  18. Earth Science: It's All about the Processes

    Science.gov (United States)

    King, Chris

    2013-01-01

    Readers of the draft new English primary science curriculum (DfE, 2012) might be concerned to see that there is much more detail on the Earth science content than previously in the United Kingdom. In this article, Chris King, a professor of Earth Science Education at Keele University and Director of the Earth Science Education Unit (ESEU),…

  19. Earthing: Health Implications of Reconnecting the Human Body to the Earth's Surface Electrons

    Science.gov (United States)

    Chevalier, Gaétan; Sinatra, Stephen T.; Oschman, James L.; Sokal, Karol; Sokal, Pawel

    2012-01-01

    Environmental medicine generally addresses environmental factors with a negative impact on human health. However, emerging scientific research has revealed a surprisingly positive and overlooked environmental factor on health: direct physical contact with the vast supply of electrons on the surface of the Earth. Modern lifestyle separates humans from such contact. The research suggests that this disconnect may be a major contributor to physiological dysfunction and unwellness. Reconnection with the Earth's electrons has been found to promote intriguing physiological changes and subjective reports of well-being. Earthing (or grounding) refers to the discovery of benefits—including better sleep and reduced pain—from walking barefoot outside or sitting, working, or sleeping indoors connected to conductive systems that transfer the Earth's electrons from the ground into the body. This paper reviews the earthing research and the potential of earthing as a simple and easily accessed global modality of significant clinical importance. PMID:22291721

  20. Earthing: Health Implications of Reconnecting the Human Body to the Earth's Surface Electrons

    Directory of Open Access Journals (Sweden)

    Gaétan Chevalier

    2012-01-01

    Full Text Available Environmental medicine generally addresses environmental factors with a negative impact on human health. However, emerging scientific research has revealed a surprisingly positive and overlooked environmental factor on health: direct physical contact with the vast supply of electrons on the surface of the Earth. Modern lifestyle separates humans from such contact. The research suggests that this disconnect may be a major contributor to physiological dysfunction and unwellness. Reconnection with the Earth's electrons has been found to promote intriguing physiological changes and subjective reports of well-being. Earthing (or grounding refers to the discovery of benefits—including better sleep and reduced pain—from walking barefoot outside or sitting, working, or sleeping indoors connected to conductive systems that transfer the Earth's electrons from the ground into the body. This paper reviews the earthing research and the potential of earthing as a simple and easily accessed global modality of significant clinical importance.

  1. Surface electronic structure of rare earth metals

    Energy Technology Data Exchange (ETDEWEB)

    Blyth, R.I.R.; Dhesi, S.S.; Gravil, P.A.; Newstead, K.; Cosso, R.; Cole, R.J.; Patchett, A.J.; Mitrelias, T. (Surface Science Research Centre, Univ. of Liverpool (United Kingdom)); Prince, N.P.; Barrett, S.D. (Surface Science Research Centre, Univ. of Liverpool (United Kingdom) Oliver Lodge Lab., Univ. of Liverpool (United Kingdom))

    1992-03-25

    Angle-resolved UV photoemission has been used to investigate the electronic structure of the (0001) surfaces of scandium, yttrium, praseodymium and gadolinium. Off-normal emission spectra were recorded with high angular resolution, enabling detailed mapping of the dispersion of valence band features. Yttrium and gadolinium show similar results to published data from Ho(0001), suggesting minimal 4f influence in the lanthanide bandstructures. Differences seen on praseodymium and scandium may be due to 4f-derived states and surface states respectively. (orig.).

  2. The Cool Surfaces of Binaries Near-Earth Asteroids

    NARCIS (Netherlands)

    Delbo, Marco; Walsh, K.; Mueller, M.

    2008-01-01

    We present results from thermal-infrared observations of binary near-Earth asteroids (NEAs). These objects, in general, have surface temperatures cooler than the average values for non-binary NEAs. We discuss how this may be evidence of higher-than-average surface thermal inertia. The comparison of

  3. NASA's Space Lidar Measurements of Earth and Planetary Surfaces

    Science.gov (United States)

    Abshire, James B.

    2010-01-01

    A lidar instrument on a spacecraft was first used to measure planetary surface height and topography on the Apollo 15 mission to the Moon in 1971, The lidar was based around a flashlamp-pumped ruby laser, and the Apollo 15-17 missions used them to make a few thousand measurements of lunar surface height from orbit. With the advent of diode pumped lasers in the late 1980s, the lifetime, efficiency, resolution and mass of lasers and space lidar all improved dramatically. These advances were utilized in NASA space missions to map the shape and surface topography of Mars with > 600 million measurements, demonstrate initial space measurements of the Earth's topography, and measured the detailed shape of asteroid. NASA's ICESat mission in Earth orbit just completed its polar ice measurement mission with almost 2 billion measurements of the Earth's surface and atmosphere, and demonstrated measurements to Antarctica and Greenland with a height resolution of a few em. Space missions presently in cruise phase and in operation include those to Mercury and a topographic mapping mission of the Moon. Orbital lidar also have been used in experiments to demonstrate laser ranging over planetary distances, including laser pulse transmission from Earth to Mars orbit. Based on the demonstrated value of the measurements, lidar is now the preferred measurement approach for many new scientific space missions. Some missions planned by NASA include a planetary mission to measure the shape and dynamics of Europa, and several Earth orbiting missions to continue monitoring ice sheet heights, measure vegetation heights, assess atmospheric CO2 concentrations, and to map the Earth surface topographic heights with 5 m spatial resolution. This presentation will give an overview of history, ongoing work, and plans for using space lidar for measurements of the surfaces of the Earth and planets.

  4. Aspects of the atmospheric surface layers on Mars and Earth

    DEFF Research Database (Denmark)

    Larsen, Søren Ejling; Ejsing Jørgensen, Hans; Landberg, L.

    2002-01-01

    and mean flow on Mars is found to obey the same scaling laws as on Earth. The largest micrometeorological differences between the two atmospheres are associated with the low air density of the Martian atmosphere. Together with the virtual absence of water vapour, it reduces the importance......The structures of mean flow and turbulence in the atmospheric surface boundary layer have been extensively studied on Earth, and to a far less extent on Mars, where only the Viking missions and the Pathfinder mission have delivered in-situ data. Largely the behaviour of surface-layer turbulence...

  5. Some observations on the greenhouse effect at the Earth's surface

    Science.gov (United States)

    Akitt, J. W.

    2018-01-01

    It is shown that the greenhouse gases carbon dioxide and water vapour reflect back to the surface, all IR radiation originating at the surface within their respective spectral bands. This reflection occurs in a very thin layer at the surface, not much over 12 cm in thickness. Heat is lost from the surface by heat exchange with the atmosphere and by loss of radiation. About 52% of radiation leaves the surface in two principal window regions but this is not enough to account for the earth's equilibrium temperature. This window radiation seems to disappear quite quickly and is replaced by black body radiation. It is this which eventually contributes to the earth's radiation balance, and has to originate approximately between 40 and 50 km altitude where the temperature is about correct, near 255 K. Doubling the CO2 concentration increases the surface temperature by about 0.9 °C and this need not have any influence higher up in the atmosphere. The surface temperature seems indeed to have no direct influence on the earth's external radiation balance.

  6. Some observations on the greenhouse effect at the Earth's surface.

    Science.gov (United States)

    Akitt, J W

    2018-01-05

    It is shown that the greenhouse gases carbon dioxide and water vapour reflect back to the surface, all IR radiation originating at the surface within their respective spectral bands. This reflection occurs in a very thin layer at the surface, not much over 12cm in thickness. Heat is lost from the surface by heat exchange with the atmosphere and by loss of radiation. About 52% of radiation leaves the surface in two principal window regions but this is not enough to account for the earth's equilibrium temperature. This window radiation seems to disappear quite quickly and is replaced by black body radiation. It is this which eventually contributes to the earth's radiation balance, and has to originate approximately between 40 and 50km altitude where the temperature is about correct, near 255K. Doubling the CO2 concentration increases the surface temperature by about 0.9°C and this need not have any influence higher up in the atmosphere. The surface temperature seems indeed to have no direct influence on the earth's external radiation balance. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Earthlike planets: Surfaces of Mercury, Venus, earth, moon, Mars

    Science.gov (United States)

    Murray, B.; Malin, M. C.; Greeley, R.

    1981-01-01

    The surfaces of the earth and the other terrestrial planets of the inner solar system are reviewed in light of the results of recent planetary explorations. Past and current views of the origin of the earth, moon, Mercury, Venus and Mars are discussed, and the surface features characteristic of the moon, Mercury, Mars and Venus are outlined. Mechanisms for the modification of planetary surfaces by external factors and from within the planet are examined, including surface cycles, meteoritic impact, gravity, wind, plate tectonics, volcanism and crustal deformation. The origin and evolution of the moon are discussed on the basis of the Apollo results, and current knowledge of Mercury and Mars is examined in detail. Finally, the middle periods in the history of the terrestrial planets are compared, and future prospects for the exploration of the inner planets as well as other rocky bodies in the solar system are discussed.

  8. Variations of the Earth's rotation rate and cyclic processes in geodynamics

    Directory of Open Access Journals (Sweden)

    B.W. Levin

    2017-05-01

    Full Text Available The authors analyzed the relationship between variations of the Earth's rotation rate and the geodynamic processes within the Earth's body, including seismic activity. The rotation rate of a planet determines its uniaxial compression along the axis of rotation and the areas of various surface elements of the body. The Earth's ellipticity variations, caused naturally by the rotation rate variations, are manifested in vertical components of precise GPS measurements. Comparative analysis of these variations is considered in view of modern theoretical ideas concerning the Earth's figure. The results justify further research that is of interest for improvement of space systems and technologies.

  9. Revised Estimate of Earth's Surface Heat Flow: 47 +- 2 TW

    Science.gov (United States)

    Davies, J. H.; Davies, D. R.

    2012-04-01

    Earth's surface heat flow provides a fundamental constraint on solid Earth dynamics. However, deriving an estimate of the total surface heat flux is complex, due to the inhomogeneous distribution of heat flow measurements and difficulties in measuring heat flux in young oceanic crust, arising due to hydrothermal circulation. A database of 38347 measurements (provided by G. Laske & G. Masters), representing a 55% increase on the number of measurements used previously, and the methods of Geographical Information Science (GIS), is used to derive a revised estimate of Earth's surface heat flux (Davies & Davies, 2010). To account for hydrothermal circulation in young oceanic crust, we use a model estimate of the heat flux, following the work of Jaupart et al., 2007; while for the rest of the globe, in an attempt to overcome the inhomogeneous distribution of measurements, we develop an average for different geological units. Two digital geology data sets are used to define the global geology: (i) continental geology - Hearn et al., 2003; and (ii) the global data-set of CCGM - Commission de la Carte Géologique du Monde, 2000. This leads to > 93,000 polygons defining Earth's geology. The influence of clustering is limited by intersecting the geology polygons with a 1 by 1 degree (at the equator) equal area grid. The average heat flow is evaluated for each geology class. The contribution of each geology class to the global surface heat flow is derived by multiplying this estimated average surface heat flux with the area of that geology class. The surface heat flow contributions of all the geology classes are summed. For Antarctica we use an estimate based on depth to Curie temperature and include a 1TW contribution from hot-spots in young ocean age. Geology classes with less than 50 readings are excluded. The raw data suggests that this method of correlating heat flux with geology has some power. Our revised estimate for Earth's global surface heat flux is 47 ± 2 TW

  10. THE EFFECTS OF RARE EARTHS ON ACTIVITY AND SURFACE ...

    African Journals Online (AJOL)

    KEY WORDS: Rare earths, Ruthenium-based catalyst, Water gas shift reaction. INTRODUCTION. The water gas shift reaction (WGSR) is one of basic processes in the chemical fertilizer industry and the key step in H2 production by reforming of hydrocarbons for fuel cells. The conventional iron-chromium WGSR catalysts do ...

  11. Theory connecting nonlocal sediment transport, earth surface roughness, and the Sadler effect

    Science.gov (United States)

    Schumer, Rina; Taloni, Alessandro; Furbish, David Jon

    2017-03-01

    Earth surface evolution, like many natural phenomena typified by fluctuations on a wide range of scales and deterministic smoothing, results in a statistically rough surface. We present theory demonstrating that scaling exponents of topographic and stratigraphic statistics arise from long-time averaging of noisy surface evolution rather than specific landscape evolution processes. This is demonstrated through use of "elastic" Langevin equations that generically describe disturbance from a flat earth surface using a noise term that is smoothed deterministically via sediment transport. When smoothing due to transport is a local process, the geologic record self organizes such that a specific Sadler effect and topographic power spectral density (PSD) emerge. Variations in PSD slope reflect the presence or absence and character of nonlocality of sediment transport. The range of observed stratigraphic Sadler slopes captures the same smoothing feature combined with the presence of long-range spatial correlation in topographic disturbance.

  12. Core Processes: Earth's eccentric magnetic field

    DEFF Research Database (Denmark)

    Finlay, Chris

    2012-01-01

    Earth’s magnetic field is characterized by a puzzling hemispheric asymmetry. Calculations of core dynamo processes suggest that lopsided growth of the planet’s inner core may be part of the cause.......Earth’s magnetic field is characterized by a puzzling hemispheric asymmetry. Calculations of core dynamo processes suggest that lopsided growth of the planet’s inner core may be part of the cause....

  13. Global distribution of Earth's surface shortwave radiation budget

    Directory of Open Access Journals (Sweden)

    N. Hatzianastassiou

    2005-01-01

    Full Text Available The monthly mean shortwave (SW radiation budget at the Earth's surface (SRB was computed on 2.5-degree longitude-latitude resolution for the 17-year period from 1984 to 2000, using a radiative transfer model accounting for the key physical parameters that determine the surface SRB, and long-term climatological data from the International Satellite Cloud Climatology Project (ISCCP-D2. The model input data were supplemented by data from the National Centers for Environmental Prediction - National Center for Atmospheric Research (NCEP-NCAR and European Center for Medium Range Weather Forecasts (ECMWF Global Reanalysis projects, and other global data bases such as TIROS Operational Vertical Sounder (TOVS and Global Aerosol Data Set (GADS. The model surface radiative fluxes were validated against surface measurements from 22 stations of the Baseline Surface Radiation Network (BSRN covering the years 1992-2000, and from 700 stations of the Global Energy Balance Archive (GEBA, covering the period 1984-2000. The model is in good agreement with BSRN and GEBA, with a negative bias of 14 and 6.5 Wm-2, respectively. The model is able to reproduce interesting features of the seasonal and geographical variation of the surface SW fluxes at global scale. Based on the 17-year average model results, the global mean SW downward surface radiation (DSR is equal to 171.6 Wm-2, whereas the net downward (or absorbed surface SW radiation is equal to 149.4 Wm-2, values that correspond to 50.2 and 43.7% of the incoming SW radiation at the top of the Earth's atmosphere. These values involve a long-term surface albedo equal to 12.9%. Significant increasing trends in DSR and net DSR fluxes were found, equal to 4.1 and 3.7 Wm-2, respectively, over the 1984-2000 period (equivalent to 2.4 and 2.2 Wm-2 per decade, indicating an increasing surface solar radiative heating. This surface SW radiative heating is primarily attributed to clouds, especially low-level, and secondarily to

  14. Fluvial geomorphology on Earth-like planetary surfaces: A review.

    Science.gov (United States)

    Baker, Victor R; Hamilton, Christopher W; Burr, Devon M; Gulick, Virginia C; Komatsu, Goro; Luo, Wei; Rice, James W; Rodriguez, J A P

    2015-09-15

    Morphological evidence for ancient channelized flows (fluvial and fluvial-like landforms) exists on the surfaces of all of the inner planets and on some of the satellites of the Solar System. In some cases, the relevant fluid flows are related to a planetary evolution that involves the global cycling of a volatile component (water for Earth and Mars; methane for Saturn's moon Titan). In other cases, as on Mercury, Venus, Earth's moon, and Jupiter's moon Io, the flows were of highly fluid lava. The discovery, in 1972, of what are now known to be fluvial channels and valleys on Mars sparked a major controversy over the role of water in shaping the surface of that planet. The recognition of the fluvial character of these features has opened unresolved fundamental questions about the geological history of water on Mars, including the presence of an ancient ocean and the operation of a hydrological cycle during the earliest phases of planetary history. Other fundamental questions posed by fluvial and fluvial-like features on planetary bodies include the possible erosive action of large-scale outpourings of very fluid lavas, such as those that may have produced the remarkable canali forms on Venus; the ability of exotic fluids, such as methane, to create fluvial-like landforms, as observed on Saturn's moon, Titan; and the nature of sedimentation and erosion under different conditions of planetary surface gravity. Planetary fluvial geomorphology also illustrates fundamental epistemological and methodological issues, including the role of analogy in geomorphological/geological inquiry.

  15. The Link between Rare-Earth Peak Formation and the Astrophysical Site of the R Process

    Science.gov (United States)

    Mumpower, Matthew R.; McLaughlin, Gail C.; Surman, Rebecca; Steiner, Andrew W.

    2016-12-01

    The primary astrophysical source of the rare-earth elements is the rapid neutron capture process (r process). The rare-earth peak that is seen in the solar r-process residuals has been proposed to originate as a pile-up of nuclei during the end of the r process. We introduce a new method utilizing Monte Carlo studies of nuclear masses in the rare-earth region, that includes self-consistently adjusting β-decay rates and neutron capture rates, to find the mass surfaces necessary for the formation of the rare-earth peak. We demonstrate our method with two types of astrophysical scenario, one corresponding to conditions typical of hot winds from core-collapse supernovae and stellar-mass accretion disks, and one corresponding to conditions typical of the ejection of the material from the tidal tails of neutron star mergers. In each type of astrophysical condition, this method successfully locates a region of enhanced stability in the mass surface that is responsible for the rare-earth peak. For each scenario, we find that the change in the mass surface has qualitatively different features, thus future measurements can shed light on the type of environment in which the r process occurred.

  16. Advancing land surface model development with satellite-based Earth observations

    Science.gov (United States)

    Orth, Rene; Dutra, Emanuel; Trigo, Isabel F.; Balsamo, Gianpaolo

    2017-04-01

    The land surface forms an essential part of the climate system. It interacts with the atmosphere through the exchange of water and energy and hence influences weather and climate, as well as their predictability. Correspondingly, the land surface model (LSM) is an essential part of any weather forecasting system. LSMs rely on partly poorly constrained parameters, due to sparse land surface observations. With the use of newly available land surface temperature observations, we show in this study that novel satellite-derived datasets help to improve LSM configuration, and hence can contribute to improved weather predictability. We use the Hydrology Tiled ECMWF Scheme of Surface Exchanges over Land (HTESSEL) and validate it comprehensively against an array of Earth observation reference datasets, including the new land surface temperature product. This reveals satisfactory model performance in terms of hydrology, but poor performance in terms of land surface temperature. This is due to inconsistencies of process representations in the model as identified from an analysis of perturbed parameter simulations. We show that HTESSEL can be more robustly calibrated with multiple instead of single reference datasets as this mitigates the impact of the structural inconsistencies. Finally, performing coupled global weather forecasts we find that a more robust calibration of HTESSEL also contributes to improved weather forecast skills. In summary, new satellite-based Earth observations are shown to enhance the multi-dataset calibration of LSMs, thereby improving the representation of insufficiently captured processes, advancing weather predictability and understanding of climate system feedbacks. Orth, R., E. Dutra, I. F. Trigo, and G. Balsamo (2016): Advancing land surface model development with satellite-based Earth observations. Hydrol. Earth Syst. Sci. Discuss., doi:10.5194/hess-2016-628

  17. Daily monitoring of the land surface of the Earth

    Science.gov (United States)

    Mascaro, J.

    2016-12-01

    Planet is an integrated aerospace and data analytics company that operates the largest fleet of Earth-imaging satellites. With more than 140 cube-sats successfully launched to date, Planet is now collecting approximately 10 million square kilometers of imagery per day (3-5m per pixel, in red, green, blue and near infrared spectral bands). By early 2017, Planet's constellation will image the entire land surface of the Earth on a daily basis. Due to investments in cloud storage and computing, approximately 75% of imagery collected is available to Planet's partners within 24 hours of capture through an Application Program Interface. This unique dataset has enormous applications for monitoring the status of Earth's natural ecosystems, as well as human settlements and agricultural welfare. Through our Ambassadors Program, Planet has made data available for researchers in areas as disparate as human rights monitoring in refugee camps, to assessments of the impact of hydroelectric installations, to tracking illegal gold mining in Amazon forests, to assessing the status of the cryosphere. Here, we share early results from Planet's research partner network, including enhanced spatial and temporal resolution of NDVI data for agricultural health in Saudi Arabia, computation of rates of illegal deforestation in Southern Peru, estimates of tropical forest carbon stocks based on data integration with active sensors, and estimates of glacial flow rates. We synthesize the potentially enormous research and scientific value of Planet's persistent monitoring capability, and discuss methods by which the data will be disseminated into the scientific community.

  18. Flexible Description and Adaptive Processing of Earth Observation Data through the BigEarth Platform

    Science.gov (United States)

    Gorgan, Dorian; Bacu, Victor; Stefanut, Teodor; Nandra, Cosmin; Mihon, Danut

    2016-04-01

    The Earth Observation data repositories extending periodically by several terabytes become a critical issue for organizations. The management of the storage capacity of such big datasets, accessing policy, data protection, searching, and complex processing require high costs that impose efficient solutions to balance the cost and value of data. Data can create value only when it is used, and the data protection has to be oriented toward allowing innovation that sometimes depends on creative people, which achieve unexpected valuable results through a flexible and adaptive manner. The users need to describe and experiment themselves different complex algorithms through analytics in order to valorize data. The analytics uses descriptive and predictive models to gain valuable knowledge and information from data analysis. Possible solutions for advanced processing of big Earth Observation data are given by the HPC platforms such as cloud. With platforms becoming more complex and heterogeneous, the developing of applications is even harder and the efficient mapping of these applications to a suitable and optimum platform, working on huge distributed data repositories, is challenging and complex as well, even by using specialized software services. From the user point of view, an optimum environment gives acceptable execution times, offers a high level of usability by hiding the complexity of computing infrastructure, and supports an open accessibility and control to application entities and functionality. The BigEarth platform [1] supports the entire flow of flexible description of processing by basic operators and adaptive execution over cloud infrastructure [2]. The basic modules of the pipeline such as the KEOPS [3] set of basic operators, the WorDeL language [4], the Planner for sequential and parallel processing, and the Executor through virtual machines, are detailed as the main components of the BigEarth platform [5]. The presentation exemplifies the development

  19. Laboratory investigations: Low Earth orbit environment chemistry with spacecraft surfaces

    Science.gov (United States)

    Cross, Jon B.

    1990-01-01

    Long-term space operations that require exposure of material to the low earth orbit (LEO) environment must take into account the effects of this highly oxidative atmosphere on material properties and the possible contamination of the spacecraft surroundings. Ground-based laboratory experiments at Los Alamos using a newly developed hyperthermal atomic oxygen (AO) source have shown that not only are hydrocarbon based materials effected but that inorganic materials such as MoS2 are also oxidized and that thin protective coatings such as Al2O3 can be breached, producing oxidation of the underlying substrate material. Gas-phase reaction products, such as SO2 from oxidation of MoS2 and CO and CO2 from hydrocarbon materials, have been detected and have consequences in terms of spacecraft contamination. Energy loss through gas-surface collisions causing spacecraft drag has been measured for a few select surfaces and has been found to be highly dependent on the surface reactivity.

  20. About the geometry of the Earth geodetic reference surfaces

    Science.gov (United States)

    Husár, Ladislav; Švaral, Peter; Janák, Juraj

    2017-10-01

    The paper focuses on the comparison of metrics of three most common reference surfaces of the Earth used in geodesy (excluding the plane which also belongs to reference surfaces used in geodesy when dealing with small areas): a sphere, an ellipsoid of revolution and a triaxial ellipsoid. The two latter surfaces are treated in a more detailed way. First, the mathematical form of the metric tensors using three types of coordinates is derived and the lengths of meridian and parallel arcs between the two types of ellipsoids are compared. Three kinds of parallels, according to the type of latitude, can be defined on a triaxial ellipsoid. We show that two types of parallels are spatial curves and one is represented by ellipses. The differences of curvature of both kinds of ellipsoid are analysed using the normal curvature radii. Priority of the chosen triaxial ellipsoid is documented by its better fit with respect to the high-degree geoid model EIGEN6c4 computed up to degree and order 2160.

  1. Stationary determinism in Observed Time Series the earth's surface temperature

    CERN Document Server

    Gutíerrez, R M

    1999-01-01

    In this work we address the feasibility of estimating and isolating the stationary and deterministic content of observational time series, {\\bf Ots}, which in general have very limited characteristics. In particular, we study the valuable earth's surface mean temperature time series, {\\bf Tts}, by applying several treatments intended to isolate the stationary and deterministic content. We give particular attention to the sensitivity of results on the different parameters involved. The effects of such treatments were assessed by means of several methods designed to estimate the stationarity of time series. In order to strengthen the significance of the results obtained we have created a comparative framework with seven test time series of well-know origin and characteristics with a similar small number of data points. We have obtained a greater understanding of the potential and limitations of the different methods when applied to real world time series. The study of the stationarity and deterministic content ...

  2. Changes in biologically active ultraviolet radiation reaching the Earth's surface.

    Science.gov (United States)

    McKenzie, Richard L; Björn, Lars Olof; Bais, Alkiviadis; Ilyasad, Mohammad

    2003-01-01

    Since publication of the 1998 UNEP Assessment, there has been continued rapid expansion of the literature on UV-B radiation. Many measurements have demonstrated the inverse relationship between column ozone amount and UV radiation, and in a few cases long-term increases due to ozone decreases have been identified. The quantity, quality and availability of ground-based UV measurements relevant to assessing the environmental impacts of ozone changes continue to improve. Recent studies have contributed to delineating regional and temporal differences due to aerosols, clouds, and ozone. Improvements in radiative transfer modelling capability now enable more accurate characterization of clouds, snow-cover, and topographical effects. A standardized scale for reporting UV to the public has gained wide acceptance. There has been increased use of satellite data to estimate geographic variability and trends in UV. Progress has been made in assessing the utility of satellite retrievals of UV radiation by comparison with measurements at the Earth's surface. Global climatologies of UV radiation are now available on the Internet. Anthropogenic aerosols play a more important role in attenuating UV irradiances than has been assumed previously, and this will have implications for the accuracy of UV retrievals from satellite data. Progress has been made inferring historical levels of UV radiation using measurements of ozone (from satellites or from ground-based networks) in conjunction with measurements of total solar radiation obtained from extensive meteorological networks. We cannot yet be sure whether global ozone has reached a minimum. Atmospheric chlorine concentrations are beginning to decrease. However, bromine concentrations are still increasing. While these halogen concentrations remain high, the ozone layer remains vulnerable to further depletion from events such as volcanic eruptions that inject material into the stratosphere. Interactions between global warming and

  3. Geophysical, petrological and mineral physics constraints on Earth's surface topography

    Science.gov (United States)

    Guerri, Mattia; Cammarano, Fabio; Tackley, Paul J.

    2015-04-01

    Earth's surface topography is controlled by isostatically compensated density variations within the lithosphere, but dynamic topography - i.e. the topography due to adjustment of surface to mantle convection - is an important component, specially at a global scale. In order to separate these two components it is fundamental to estimate crustal and mantle density structure and rheological properties. Usually, crustal density is constrained from interpretation of available seismic data (mostly VP profiles) based on empirical relationships such those in Brocher [2005]. Mantle density structure is inferred from seismic tomography models. Constant coefficients are used to interpret seismic velocity anomalies in density anomalies. These simplified methods are unable to model the effects that pressure and temperature variations have on mineralogical assemblage and physical properties. Our approach is based on a multidisciplinary method that involves geophysical observables, mineral physics constraints, and petrological data. Mantle density is based on the thermal interpretation of global seismic tomography models assuming various compositional structures, as in Cammarano et al. [2011]. We further constrain the top 150 km by including heat-flow data and considering the thermal evolution of the oceanic lithosphere. Crustal density is calculated as in Guerri and Cammarano [2015] performing thermodynamic modeling of various average chemical compositions proposed for the crust. The modeling, performed with the code PerpleX [Connolly, 2005], relies on the thermodynamic dataset from Holland and Powell [1998]. Compressional waves velocity and crustal layers thickness from the model CRUST 1.0 [Laske et al., 2013] offer additional constrains. The resulting lithospheric density models are tested against gravity (GOCE) data. Various crustal and mantle density models have been tested in order to ascertain the effects that uncertainties in the estimate of those features have on the

  4. Bioeffectiveness of Cosmic Rays Near the Earth Surface

    Science.gov (United States)

    Belisheva, N. K.

    2014-10-01

    Experimental studies of the dynamics of morphological and functional state of the diverse biosystems (microflora, plant Maranta leuconeura «Fascinator», cell cultures, human peripheral blood, the human body ) have shown that geocosmical agents modulated the functional state of biological systems Belisheva 2006; Belisheva et all 2007 ) . First time on the experimental data showed the importance of the increase in the fluxes of solar cosmic rays (CRs ) with high energies (Belisheva et all 2002; 2012; Belisheva, Lammer, Biernat, 2004) and galactic cosmic ray variations (Belisheva et al, 2005; 2006; Vinnichenko Belisheva, 2009 ) near the Earth surface for the functional state of biosystems. The evidence of the presence of the particles with high bioeffectiveness in the secondary cosmic rays was obtained by simulating the particle cascades in the atmosphere, performed by using Geant4 (Planetocosmics, based on the Monte Carlo code (Maurchev et al, 2011), and experimental data, where radiobiological effects of cosmic rays were revealed. Modeling transport of solar protons through the Earth's atmosphere, taking into account the angular and energy distributions of secondary particles in different layers of the atmosphere, allowed us to estimate the total neutron flux during three solar proton events, accompanied by an increase in the intensity of the nucleon component of secondary cosmic rays - Ground Level Enhancement GLE (43, 44, 45) in October 1989 (19, 22, 24 October). The results obtained by simulation were compared with the data of neutron monitors and balloon measurements made during solar proton events. Confirmation of the neutron fluxes near the Earth surface during the GLE (43, 44, 45) were obtained in the experiments on the cellular cultures (Belisheva et al. 2012). A direct evidence of biological effects of CR has been demonstrated in experiments with three cellular lines growing in culture during three events of Ground Level Enhancement (GLEs) in the

  5. The Earth System Documentation (ES-DOC) Software Process

    Science.gov (United States)

    Greenslade, M. A.; Murphy, S.; Treshansky, A.; DeLuca, C.; Guilyardi, E.; Denvil, S.

    2013-12-01

    Earth System Documentation (ES-DOC) is an international project supplying high-quality tools & services in support of earth system documentation creation, analysis and dissemination. It is nurturing a sustainable standards based documentation eco-system that aims to become an integral part of the next generation of exa-scale dataset archives. ES-DOC leverages open source software, and applies a software development methodology that places end-user narratives at the heart of all it does. ES-DOC has initially focused upon nurturing the Earth System Model (ESM) documentation eco-system and currently supporting the following projects: * Coupled Model Inter-comparison Project Phase 5 (CMIP5); * Dynamical Core Model Inter-comparison Project (DCMIP); * National Climate Predictions and Projections Platforms Quantitative Evaluation of Downscaling Workshop. This talk will demonstrate that ES-DOC implements a relatively mature software development process. Taking a pragmatic Agile process as inspiration, ES-DOC: * Iteratively develops and releases working software; * Captures user requirements via a narrative based approach; * Uses online collaboration tools (e.g. Earth System CoG) to manage progress; * Prototypes applications to validate their feasibility; * Leverages meta-programming techniques where appropriate; * Automates testing whenever sensibly feasible; * Streamlines complex deployments to a single command; * Extensively leverages GitHub and Pivotal Tracker; * Enforces strict separation of the UI from underlying API's; * Conducts code reviews.

  6. Fluvial geomorphology on Earth-like planetary surfaces: A review

    Science.gov (United States)

    Baker, Victor R.; Hamilton, Christopher W.; Burr, Devon M.; Gulick, Virginia C.; Komatsu, Goro; Luo, Wei; Rice, James W.; Rodriguez, J.A.P.

    2017-01-01

    Morphological evidence for ancient channelized flows (fluvial and fluvial-like landforms) exists on the surfaces of all of the inner planets and on some of the satellites of the Solar System. In some cases, the relevant fluid flows are related to a planetary evolution that involves the global cycling of a volatile component (water for Earth and Mars; methane for Saturn’s moon Titan). In other cases, as on Mercury, Venus, Earth’s moon, and Jupiter’s moon Io, the flows were of highly fluid lava. The discovery, in 1972, of what are now known to be fluvial channels and valleys on Mars sparked a major controversy over the role of water in shaping the surface of that planet. The recognition of the fluvial character of these features has opened unresolved fundamental questions about the geological history of water on Mars, including the presence of an ancient ocean and the operation of a hydrological cycle during the earliest phases of planetary history. Other fundamental questions posed by fluvial and fluvial-like features on planetary bodies include the possible erosive action of large-scale outpourings of very fluid lavas, such as those that may have produced the remarkable canali forms on Venus; the ability of exotic fluids, such as methane, to create fluvial-like landforms, as observed on Saturn’s moon, Titan; and the nature of sedimentation and erosion under different conditions of planetary surface gravity. Planetary fluvial geomorphology also illustrates fundamental epistemological and methodological issues, including the role of analogy in geomorphological/geological inquiry. PMID:29176917

  7. Concept of a space optoelectronic system for environmental monitoring of the near-earth space, atmosphere, and earth surface

    Science.gov (United States)

    Eltsov, Anatoli V.; Karasev, Vladimir I.; Kolotkov, Vjacheslav V.; Kondranin, Timothy V.

    1997-06-01

    how large the space (from several meters to hundreds of kilometers) and time (from an hour to several months) scales of the above monitoring might be there is a common dominating factor which could favor creation of a general- purpose observation and control system based on passive optoelectronic instrumentation of different levels of sophistication. This dominating factor refers to the possibility of obtaining information about the state of objects by way to recording parameters of radiation emitted by them in wavelengths of 250 nm to tens of microns. The fact that phenomena and processes occurring in the atmosphere are closely interrelated gives implications as to the structure of such a system which is supposed to be a common information network basically consisting of an orbiting constellation of a number of small-size spacecraft equipped with optoelectronic instrumentation of different complexity, and a ground segment to provide acquisition and processing of information about the status of every ecosphere shell including comprehensive thematic analysis. The existing domestic (based on the `Meteor', `Resurs-O', `Okean', etc. spacecraft) and foreign (NOAA, SPOT, LANDSAT, ERS, etc.) space systems are designed for solution of only a limited number of atmosphere monitoring issues, namely those related to meteorology and studies of natural resources. As for the near-Earth space there are at present only ground facilities whose monitoring capabilities are also limited. It should be noted that in recent years in the USA similar activities have been in full swing targeted at creation of a system like the one mentioned above (the Earth Observation System). A system comprising four spacecraft of the NOAA series and a distributed ground network for receiving analog (with 4 km spatial resolution) and digital (with 1 km spatial resolution) multispectral data pertaining to the status of the atmosphere and the underlying surface is currently operational. This system presents

  8. Surface chemistry of rare-earth oxide surfaces at ambient conditions: reactions with water and hydrocarbons

    Science.gov (United States)

    Külah, Elçin; Marot, Laurent; Steiner, Roland; Romanyuk, Andriy; Jung, Thomas A.; Wäckerlin, Aneliia; Meyer, Ernst

    2017-03-01

    Rare-earth (RE) oxide surfaces are of significant importance for catalysis and were recently reported to possess intrinsic hydrophobicity. The surface chemistry of these oxides in the low temperature regime, however, remains to a large extent unexplored. The reactions occurring at RE surfaces at room temperature (RT) in real air environment, in particular, in presence of polycyclic aromatic hydrocarbons (PAHs), were not addressed until now. Discovering these reactions would shed light onto intermediate steps occurring in automotive exhaust catalysts before reaching the final high operational temperature and full conversion of organics. Here we first address physical properties of the RE oxide, nitride and fluoride surfaces modified by exposure to ambient air and then we report a room temperature reaction between PAH and RE oxide surfaces, exemplified by tetracene (C18H12) on a Gd2O3. Our study evidences a novel effect - oxidation of higher hydrocarbons at significantly lower temperatures (~300 K) than previously reported (>500 K). The evolution of the surface chemical composition of RE compounds in ambient air is investigated and correlated with the surface wetting. Our surprising results reveal the complex behavior of RE surfaces and motivate follow-up studies of reactions between PAH and catalytic surfaces at the single molecule level.

  9. Virtual Earth System Laboratory (VESL): Effective Visualization of Earth System Data and Process Simulations

    Science.gov (United States)

    Quinn, J. D.; Larour, E. Y.; Cheng, D. L. C.; Halkides, D. J.

    2016-12-01

    The Virtual Earth System Laboratory (VESL) is a Web-based tool, under development at the Jet Propulsion Laboratory and UC Irvine, for the visualization of Earth System data and process simulations. It contains features geared toward a range of applications, spanning research and outreach. It offers an intuitive user interface, in which model inputs are changed using sliders and other interactive components. Current capabilities include simulation of polar ice sheet responses to climate forcing, based on NASA's Ice Sheet System Model (ISSM). We believe that the visualization of data is most effective when tailored to the target audience, and that many of the best practices for modern Web design/development can be applied directly to the visualization of data: use of negative space, color schemes, typography, accessibility standards, tooltips, etc cetera. We present our prototype website, and invite input from potential users, including researchers, educators, and students.

  10. Digital image processing of earth observation sensor data

    Science.gov (United States)

    Bernstein, R.

    1976-01-01

    This paper describes digital image processing techniques that were developed to precisely correct Landsat multispectral earth observation data and gives illustrations of the results achieved, e.g., geometric corrections with an error of less than one picture element, a relative error of one-fourth picture element, and no radiometric error effect. Techniques for enhancing the sensor data, digitally mosaicking multiple scenes, and extracting information are also illustrated.

  11. Ultraviolet radiation climatology of the Earth`s surface and lower atmosphere. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Madronich, S. [National Center for Atmospheric Research, Boulder, CO (United States). Atmospheric Chemistry Div.; Stamnes, K. [Univ. of Alaska, Fairbanks, AK (United States). Dept. of Physics

    1999-03-01

    Ultraviolet (UV) radiation is the driving force of tropospheric chemistry and is furthermore detrimental to most living tissues. A three year modeling program was carried out to characterize the UV radiation in the lower atmosphere, with the objective of development a climatology of UV biologically active radiation, and of photo-dissociation reaction rates that are key to tropospheric chemistry. A comprehensive model, the Tropospheric Ultraviolet-Visible (TUV) model, was developed and made available to the scientific community. The model incorporates updated spectroscopic data, recent advances in radiative transfer theory, and allows flexible customization for the needs of different users. The TUV model has been used in conjunction with satellite-derived measurements of total atmospheric ozone and cloud amount, to develop a global climatology of UV radiation reaching the surface of the Earth. Initial validation studies are highly encouraging, showing that model predictions agree with direct measurements to ca. 5--10% at times when environmental conditions are well known, and to 10--30% for monthly averages when local environmental conditions can only be estimated remotely from satellite-based measurements. Additional validation studies are continuing.

  12. A box model for representing estuarine physical processes in Earth system models

    Science.gov (United States)

    Sun, Qiang; Whitney, Michael M.; Bryan, Frank O.; Tseng, Yu-heng

    2017-04-01

    Appropriately treating riverine freshwater discharge into the oceans in Earth system models is a challenging problem. Commonly, the river runoff is discharged into the ocean models with zero salinity and arbitrarily distributed either horizontally or vertically over several grid cells. Those approaches entirely neglect estuarine physical processes that modify river inputs before they reach the open ocean. In order to realistically represent riverine freshwater inputs in Earth system models, a physically based Estuary Box Model (EBM) is developed to parameterize the mixing processes in estuaries. The EBM represents the estuary exchange circulation with a two-layer box structure. It takes as input the river volume flux from the land surface model and the subsurface salinity at the estuary mouth from the ocean model. It delivers the estuarine outflow salinity and net volume flux into and out of the estuary to the ocean model. An offline test of the EBM forced with observed conditions for the Columbia River system shows good agreement with observations of outflow salinity and high-resolution simulations of the exchange flow volume flux. To illustrate the practicality of use of the EBM in an Earth system model, the EBM is implemented for all coastal grid cells with river runoff in the Community Earth System Model (CESM). Compared to the standard version of CESM, which treats runoff as an augmentation to precipitation, the EBM increases sea surface salinity and reduces stratification near river mouths. The EBM also leads to significant regional and remote changes in CESM ocean surface salinities.

  13. Climatologies at high resolution for the earth's land surface areas

    Science.gov (United States)

    Karger, Dirk Nikolaus; Conrad, Olaf; Böhner, Jürgen; Kawohl, Tobias; Kreft, Holger; Soria-Auza, Rodrigo Wilber; Zimmermann, Niklaus E.; Linder, H. Peter; Kessler, Michael

    2017-09-01

    High-resolution information on climatic conditions is essential to many applications in environmental and ecological sciences. Here we present the CHELSA (Climatologies at high resolution for the earth's land surface areas) data of downscaled model output temperature and precipitation estimates of the ERA-Interim climatic reanalysis to a high resolution of 30 arc sec. The temperature algorithm is based on statistical downscaling of atmospheric temperatures. The precipitation algorithm incorporates orographic predictors including wind fields, valley exposition, and boundary layer height, with a subsequent bias correction. The resulting data consist of a monthly temperature and precipitation climatology for the years 1979-2013. We compare the data derived from the CHELSA algorithm with other standard gridded products and station data from the Global Historical Climate Network. We compare the performance of the new climatologies in species distribution modelling and show that we can increase the accuracy of species range predictions. We further show that CHELSA climatological data has a similar accuracy as other products for temperature, but that its predictions of precipitation patterns are better.

  14. The Concept of a Multichannel System for Surface, Atmosphere Investigations of the Earth and Near Space Observations

    Science.gov (United States)

    Kuzkov, V. P.; Eremenko, N. A.; Khymenko, O. A.; Kugel, V. I.; Yatsenko, V. A.

    2000-02-01

    The concept of the multichannel system is designed to perform surface of the Earth investigations, atmosphere and ionosphere investigations, scanning the atmosphere up and down from 15 to 120 km per orbit, near space investigations continuously pointing towards the astronomical object. Surface of the Earth investigations: The scanning the earth surface in visible, near IR in photometer and spectro-photometer regimes with resolution 15-20 m. In this way we will perform liquid water control, land and surface temperature measurements, fire and environmental monitoring, estimation of agriculture products, gas and oil prognostication. Atmosphere and ionosphere investigations: * Measurement the temperature of atmosphere for investigate the distributions of the atmosphere gravitation waves, it's connections with process on the earth surface. * Measurement of CO and CO 2 molecules in atmosphere and it's influence on " hotbed " effect in atmosphere. Measurement stratospheric ozone , investigations the "ozone hole" region and it's influence on process in ionosphere. * Study some of the mechanisms that provide coupling between the upper and lower atmosphere, influence the process on the land and lower atmosphere on process in upper atmosphere and in ionosphere. Investigation the influence of turbulent transport and corpuscular radiation on the processes in atmosphere and ionosphere. Astronomy: The main objective is to perform detailed studies of the physics and the chemistry of the comets, planets, bright stars, interstellar molecular clouds. The following classes of objects will be main targets for observations: * Comets: Studies of outgassing of water, the size of active regions and estimates density of molecules in short and long period comets.

  15. A Stream Processing Engine Approach to Earth Science Data Processing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Timely processing of raw Earth science data for calibration and validation in a highly distributed and networked environment, and its storage at Distributed Active...

  16. Auroral phenomenology and magnetospheric processes earth and other planets

    CERN Document Server

    Keiling, Andreas; Bagenal, Fran; Karlsson, Tomas

    2013-01-01

    Published by the American Geophysical Union as part of the Geophysical Monograph Series. Many of the most basic aspects of the aurora remain unexplained. While in the past terrestrial and planetary auroras have been largely treated in separate books, Auroral Phenomenology and Magnetospheric Processes: Earth and Other Planets takes a holistic approach, treating the aurora as a fundamental process and discussing the phenomenology, physics, and relationship with the respective planetary magnetospheres in one volume. While there are some behaviors common in auroras of the diffe

  17. The Atmospheric Surface Layer in the Polar Regions of the Earth

    Science.gov (United States)

    Kovadlo, P. G.; Shikhovtsev, A. Yu.; Yazev, S. A.

    2017-05-01

    As studies of the Earth history show the energy power and amount of catastrophic events during the planet evolution has been decreasing. Gradually the Earth "was adjusted" under the influence of external factors and internal sources of energy were weakened. The relative stability of climatic characteristics over millions of years indicates this. The modern surface Earth temperature increasing over the past 150 years has been proved by analyzing the series of network instrumental hydrometeorological measurements. The authors of this study proposed a hypothesis to explain the observed warming of the climate. It is supposed that there was a land with enclosed water reservoirs in the past at the Arctic ocean site. Calculations and observations show that there were favorable conditions for the formation and growth of the perennial glaciers` without access of warm ocean waters in the polar region. Further the mass of the Arctic ice sheet increasing led to subsidence of the earth's crust under the influence of its weight. Low-lying plains under the ice were lower than the ocean level. The access of oceanic waters to the ice sheet led to the washing of the base by the waters of the Atlantic and the Pacific oceans. Warm waters largely destroyed the floating part of the ice sheet. Heat which was spent on melting ice in the past warm up the atmosphere and ocean nowadays. Currently, the final stage of this process is observed and the factors discussed are the main cause of the observed warming.

  18. Carbon isotope heterogeneities in deep Earth: Recycling of surface carbon or from core?

    Science.gov (United States)

    Satish-Kumar, Madhusoodhan

    2017-04-01

    Subduction of crustal materials, mantle melting and upwelling of deep mantle, in addition to a potential source from the core, largely controls the Earth's deep carbon cycle. Large variations in carbon isotopic composition between different reservoirs have been used widely to differentiate the source of carbon and to understand the carbon inventories and its recycling processes. However, how far high-temperature and hign-pressure conditions can affect the carbon isotope distribution, is a question still unanswered to clearly address the deep carbon cycle. I present here a review on carbon isotope fractionation processes in deep Earth and critically evaluate whether we can easily differentiate between surface carbon and deep carbon based on isotope characteristics. Recent experimental carbon isotope fractionation studies in the Fe-C system suggests that light carbon is selectively partition into metallic core during early magma ocean environment (Satish-Kumar et al., 2011). Furthermore, carbonate melts can be a medium for efficient crystallisation of diamonds in Earth's mantle (Palyanov et al., 2013). Rayleigh fractionation modelling based on fractionation suggests that core can be a reservoir of 12C enriched carbon and can itself form a reservoir which can cause heterogeneity in mantle carbon (Wood et al., 2013). In addition, high pressure experiments in the carbon-saturated model harzburgite system (Enstatite-Magnesite-Olivine-Graphite), carbonated silicate melting resulted in 13C enrichment in the carbon dissolved in the silicate melt relative to elemental graphite (Mizutani et al., 2014). 13C enrichment in carbonate melt were further confirmed in experiments where redox melting between olivine and graphite produced a carbonate melt as well as carbonate reduction experiments to form graphite. A third factor, still unconquered is the effect of pressure on isotope fractionation process. Theoretical studies as well as preliminary experimental studies have suggested

  19. Earth's surface fluid variations and deformations from GPS and GRACE in global warming

    CERN Document Server

    Jin, Shuanggen; Feng, Guiping

    2011-01-01

    Global warming is affecting our Earth's environment. For example, sea level is rising with thermal expansion of water and fresh water input from the melting of continental ice sheets due to human-induced global warming. However, observing and modeling Earth's surface change has larger uncertainties in the changing rate and the scale and distribution of impacts due to the lack of direct measurements. Nowadays, the Earth observation from space provides a unique opportunity to monitor surface mass transfer and deformations related to climate change, particularly the global positioning system (GPS) and the Gravity Recovery and Climate Experiment (GRACE) with capability of estimating global land and ocean water mass. In this paper, the Earth's surface fluid variations and deformations are derived and analyzed from global GPS and GRACE measurements. The fluids loading deformation and its interaction with Earth system, e.g., Earth Rotation, are further presented and discussed.

  20. Tropical sea surface temperatures and the earth's orbital eccentricity cycles

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, S.M.; Fernandes, A.A.; Mohan, R.

    cyclicities at ~100- and ~400-ka corresponding to the Earth's orbital eccentricity cycles. Results, therefore imply that the tropical Indian Ocean warm pool persisted during the Quaternary and the paleo-SSTs fluctuating at the orbital eccentricity frequencies...

  1. Earth System Research Laboratory Long-Term Surface Aerosol Measurements

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Aerosol measurements began at the NOAA Earth System Research Laboratory (ESRL) Global Monitoring Division (GMD) baseline observatories in the mid-1970's with the...

  2. The Structure and Dynamics of the Main Magnetic Field of the Earth on its Surface and in the Near Space

    Science.gov (United States)

    Orlyuk, M. I.; Romenets, A. A.

    Determination of space-temporal structure of the Earth's magnetic field (EMF) on its surface and in near space is extremely necessary and actual, in connection with its influence on the character of passing of processes in magnetosphere and ionosphere, and on mechanisms and magnetic activity intensity, which are considered as a substantial ecological factor.

  3. Monitoring of the Earth's surface deformation in the area of water dam Zarnowiec

    Science.gov (United States)

    Mojzes, Marcel; Wozniak, Marek; Habel, Branislav; Macak, Marek

    2017-04-01

    Mathematical and physical research directly motivates geodetic community which can provide very accurate measurements for testing of the proposed models Earth's surface motion near the water dams should be monitored due to the security of the area. This is a process which includes testing of existing models and their physical parameters. Change of the models can improve the practical results for analyzing the trends of motion in the area of upper reservoir of water dam Zarnowiec. Since 1998 Warsaw University of Technology realized a research focused on the horizontal displacements of the upper reservoir of water dam Zarnowiec. The 15 selected control points located on the upper reservoir crown of the water dam were monitored by classical distance measurements. It was found out that changes in the object's geometry occur due to the variation of the water level. The control measurements of the changes in the object's geometry occurring during the process of emptying and filling of the upper reservoir of water dam were compared with the deformations computed using improved Boussinesqués method programmed in the software MATLAB and ANSYS for elastic and isotropic half space as derivation of suitable potentials extended to the loaded region. The details and numerical results of this process are presented This presentation was prepared within the project "National Centre for Diagnostic of the Earth's Surface Deformations in the Area of Slovakia", ITMS code: 26220220108.

  4. Facilitating NASA Earth Science Data Processing Using Nebula Cloud Computing

    Science.gov (United States)

    Chen, A.; Pham, L.; Kempler, S.; Theobald, M.; Esfandiari, A.; Campino, J.; Vollmer, B.; Lynnes, C.

    2011-12-01

    Cloud Computing technology has been used to offer high-performance and low-cost computing and storage resources for both scientific problems and business services. Several cloud computing services have been implemented in the commercial arena, e.g. Amazon's EC2 & S3, Microsoft's Azure, and Google App Engine. There are also some research and application programs being launched in academia and governments to utilize Cloud Computing. NASA launched the Nebula Cloud Computing platform in 2008, which is an Infrastructure as a Service (IaaS) to deliver on-demand distributed virtual computers. Nebula users can receive required computing resources as a fully outsourced service. NASA Goddard Earth Science Data and Information Service Center (GES DISC) migrated several GES DISC's applications to the Nebula as a proof of concept, including: a) The Simple, Scalable, Script-based Science Processor for Measurements (S4PM) for processing scientific data; b) the Atmospheric Infrared Sounder (AIRS) data process workflow for processing AIRS raw data; and c) the GES-DISC Interactive Online Visualization ANd aNalysis Infrastructure (GIOVANNI) for online access to, analysis, and visualization of Earth science data. This work aims to evaluate the practicability and adaptability of the Nebula. The initial work focused on the AIRS data process workflow to evaluate the Nebula. The AIRS data process workflow consists of a series of algorithms being used to process raw AIRS level 0 data and output AIRS level 2 geophysical retrievals. Migrating the entire workflow to the Nebula platform is challenging, but practicable. After installing several supporting libraries and the processing code itself, the workflow is able to process AIRS data in a similar fashion to its current (non-cloud) configuration. We compared the performance of processing 2 days of AIRS level 0 data through level 2 using a Nebula virtual computer and a local Linux computer. The result shows that Nebula has significantly

  5. Two-way feedback between biology and deep Earth processes

    DEFF Research Database (Denmark)

    Sleep, Norman; Bird, Dennis K.; Pope, Emily Catherine

    The presence of the metamorphic products of banded iron formation and black shale indicate that the Earth teemed with life by the time of the earliest preserved rocks, ca. 3.85 Ga. Iron and sulfur-based anoxygenic photosynthesis with full carbon cycles was present by this time. The pH of the ocean......’s surface and interior cooled following the moon-forming impact. The oceans passed through conditions favored by thermophile organisms before becoming clement. Ocean pH was ~6 and bars of CO2 existed in the atmosphere. Subduction removed the CO2 into the mantle before the time of rock record. Serpentinite...... or a few ocean-boiling impacts left thermophile survivors in their wake. Overall, the molecular biology of extant life likely conserves features that relate to its earliest abodes....

  6. Explicitly representing soil microbial processes in Earth system models: Soil microbes in earth system models

    Energy Technology Data Exchange (ETDEWEB)

    Wieder, William R. [Climate and Global Dynamics Division, National Center for Atmospheric Research, Boulder Colorado USA; Allison, Steven D. [Department of Ecology and Evolutionary Biology, University of California, Irvine California USA; Department of Earth System Science, University of California, Irvine California USA; Davidson, Eric A. [Appalachian Laboratory, University of Maryland Center for Environmental Science, Frostburg Maryland USA; Georgiou, Katerina [Department of Chemical and Biomolecular Engineering, University of California, Berkeley California USA; Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley California USA; Hararuk, Oleksandra [Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, Victoria British Columbia Canada; He, Yujie [Department of Earth System Science, University of California, Irvine California USA; Department of Earth, Atmospheric and Planetary Sciences, Purdue University, West Lafayette Indiana USA; Hopkins, Francesca [Department of Earth System Science, University of California, Irvine California USA; Jet Propulsion Laboratory, California Institute of Technology, Pasadena California USA; Luo, Yiqi [Department of Microbiology & Plant Biology, University of Oklahoma, Norman Oklahoma USA; Smith, Matthew J. [Computational Science Laboratory, Microsoft Research, Cambridge UK; Sulman, Benjamin [Department of Biology, Indiana University, Bloomington Indiana USA; Todd-Brown, Katherine [Department of Microbiology & Plant Biology, University of Oklahoma, Norman Oklahoma USA; Pacific Northwest National Laboratory, Richland Washington USA; Wang, Ying-Ping [CSIRO Ocean and Atmosphere Flagship, Aspendale Victoria Australia; Xia, Jianyang [Department of Microbiology & Plant Biology, University of Oklahoma, Norman Oklahoma USA; Tiantong National Forest Ecosystem Observation and Research Station, School of Ecological and Environmental Sciences, East China Normal University, Shanghai China; Xu, Xiaofeng [Department of Biological Sciences, University of Texas at El Paso, Texas USA

    2015-10-01

    Microbes influence soil organic matter (SOM) decomposition and the long-term stabilization of carbon (C) in soils. We contend that by revising the representation of microbial processes and their interactions with the physicochemical soil environment, Earth system models (ESMs) may make more realistic global C cycle projections. Explicit representation of microbial processes presents considerable challenges due to the scale at which these processes occur. Thus, applying microbial theory in ESMs requires a framework to link micro-scale process-level understanding and measurements to macro-scale models used to make decadal- to century-long projections. Here, we review the diversity, advantages, and pitfalls of simulating soil biogeochemical cycles using microbial-explicit modeling approaches. We present a roadmap for how to begin building, applying, and evaluating reliable microbial-explicit model formulations that can be applied in ESMs. Drawing from experience with traditional decomposition models we suggest: (1) guidelines for common model parameters and output that can facilitate future model intercomparisons; (2) development of benchmarking and model-data integration frameworks that can be used to effectively guide, inform, and evaluate model parameterizations with data from well-curated repositories; and (3) the application of scaling methods to integrate microbial-explicit soil biogeochemistry modules within ESMs. With contributions across scientific disciplines, we feel this roadmap can advance our fundamental understanding of soil biogeochemical dynamics and more realistically project likely soil C response to environmental change at global scales.

  7. Using 3D Printers to Model Earth Surface Topography for Increased Student Understanding and Retention

    Science.gov (United States)

    Thesenga, David; Town, James

    2014-05-01

    In February 2000, the Space Shuttle Endeavour flew a specially modified radar system during an 11-day mission. The purpose of the multinational Shuttle Radar Topography Mission (SRTM) was to "obtain elevation data on a near-global scale to generate the most complete high-resolution digital topographic database of Earth" by using radar interferometry. The data and resulting products are now publicly available for download and give a view of the landscape removed of vegetation, buildings, and other structures. This new view of the Earth's topography allows us to see previously unmapped or poorly mapped regions of the Earth as well as providing a level of detail that was previously unknown using traditional topographic mapping techniques. Understanding and appreciating the geographic terrain is a complex but necessary requirement for middle school aged (11-14yo) students. Abstract in nature, topographic maps and other 2D renderings of the Earth's surface and features do not address the inherent spatial challenges of a concrete-learner and traditional methods of teaching can at times exacerbate the problem. Technological solutions such as 3D-imaging in programs like Google Earth are effective but lack the tactile realness that can make a large difference in learning comprehension and retention for these young students. First developed in the 1980's, 3D printers were not commercial reality until recently and the rapid rise in interest has driven down the cost. With the advent of sub US1500 3D printers, this technology has moved out of the high-end marketplace and into the local office supply store. Schools across the US and elsewhere in the world are adding 3D printers to their technological workspaces and students have begun rapid-prototyping and manufacturing a variety of projects. This project attempted to streamline the process of transforming SRTM data from a GeoTIFF format by way of Python code. The resulting data was then inputted into a CAD-based program for

  8. Stellar and Extragalactic Radiation at the Earth's Surface Jean ...

    Indian Academy of Sciences (India)

    Abstract. Reviving a calculation made by Eddington in the 1920s, and using the most recent and comprehensive databases available on stars and galaxies, including more than 2,500,000 stars and around 20,000 galaxies we have computed their total radiation received at the Earth just outside its atmosphere. This radiation ...

  9. Exploring the geophysical signatures of microbial processes in the earth

    Energy Technology Data Exchange (ETDEWEB)

    Slater, L.; Atekwana, E.; Brantley, S.; Gorby, Y.; Hubbard, S. S.; Knight, R.; Morgan, D.; Revil, A.; Rossbach, S.; Yee, N.

    2009-05-15

    AGU Chapman Conference on Biogeophysics; Portland, Maine, 13-16 October 2008; Geophysical methods have the potential to detect and characterize microbial growth and activity in subsurface environments over different spatial and temporal scales. Recognition of this potential has resulted in the development of a new subdiscipline in geophysics called 'biogeophysics,' a rapidly evolving Earth science discipline that integrates environmental microbiology, geomicrobiology, biogeochemistry, and geophysics to investigate interactions that occur between the biosphere (microorganisms and their products) and the geosphere. Biogeophysics research performed over the past decade has confirmed the potential for geophysical techniques to detect microbes, microbial growth/biofilm formation, and microbe-mineral interactions. The unique characteristics of geophysical data sets (e.g., noninvasive data acquisition, spatially continuous properties retrieved) present opportunities to explore geomicrobial processes outside of the laboratory, at unique spatial scales unachievable with microbiological techniques, and possibly in remote environments such as the deep ocean. In response to this opportunity, AGU hosted a Chapman Conference with a mission to bring together geophysicists, biophysicists, geochemists, geomicrobiologists, and environmental microbiologists conducting multidisciplinary research with potential impact on biogeophysics in order to define the current state of the science, identify the critical questions facing the community, and generate a road map for establishing biogeophysics as a critical subdiscipline of Earth science research. For more information on the conference, see http://www.agu.org/meetings/chapman/2008/fcall/.

  10. THE EFFECTS OF RARE EARTHS ON ACTIVITY AND SURFACE ...

    African Journals Online (AJOL)

    A series of Ru-RE/γ-AL2O3 (RE = Ce, Pr, La, Sm, Tb or Gd) and Ru/γ-AL2O3 catalysts were prepared by impregnation method. The influence of rare earths on the catalytic performance of Ru/γ-AL2O3 catalyst for the water gas shift reaction was studied. The catalysts were characterized by X-ray diffraction (XRD), ...

  11. The role of impacting processes in the chemical evolution of the atmosphere of primordial Earth

    Science.gov (United States)

    Mukhin, Lev M.; Gerasimov, M. V.

    1991-01-01

    The role of impacting processes in the chemical evolution of the atmosphere of primordial Earth is discussed. The following subject areas are covered: (1) Earth's initial atmosphere; (2) continuous degassing; (3) impact processes and the Earth's protoatmosphere; and (4) the evolution of an impact-generated atmosphere.

  12. Study of Strains of The Earth Surface In Large Cities By Satellite Methods

    Science.gov (United States)

    Blank, L.; Genike, A.; Guseva, T.

    In recent years the problem of learning modern geodynamic processes has increased sharply both within the limits of all terrestrial globe, and in its separate regions. Terri- tories of large cities are the focus of increased attention. Severe distractions of build- ings and engineering facilities take place due to strains on the earth's surface caused by intensive development of underground space, violations and disturbance of hy- drocondition, vibrations of a geologic medium by transportation facilities, and other reasons. Such phenomena became a reason for geodesic monitoring of the largest megalopolis of Russia, the city of Moscow. A geodynamic GPS network was created. The network encompasses the city and its suburbs. At the present time, nine series of high-precision measurements were taken by GPS, mainly during spring and fall seasons. The results of this analysis indicated that the strain on the outer layer of geologic patterns could reach 1-4 centimeters in the territory of Moscow. The central part of the city presents peculiar lowering. The joint analysis of geodesic, geophysical and geologic studies al- lowed the conclusion to be drawn that level variations of groundwaters and formation of depressive whirlpools are the reasons for these deformations. Results of GPS monitoring demonstrate the necessity to continue keeping track of developing strains on the earth's surface, as well as performing additional geophysical observations.

  13. Water surface capturing by image processing

    Science.gov (United States)

    An alternative means of measuring the water surface interface during laboratory experiments is processing a series of sequentially captured images. Image processing can provide a continuous, non-intrusive record of the water surface profile whose accuracy is not dependent on water depth. More trad...

  14. DETERMINING SURFACE TEMPERATURE AND CLOUD TEMPERATURE FROM METEOROLOGICAL EARTH SATELLITES,

    Science.gov (United States)

    ATMOSPHERIC TEMPERATURE, *METEOROLOGICAL SATELLITES), SURFACE TEMPERATURE , CLOUDS, BLACKBODY RADIATION, PERIODIC VARIATIONS, INTEGRALS, BOUNDARY LAYER, INTENSITY, ERRORS, CORRECTIONS, FUNCTIONS(MATHEMATICS), USSR

  15. UV SURFACE ENVIRONMENT OF EARTH-LIKE PLANETS ORBITING FGKM STARS THROUGH GEOLOGICAL EVOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Rugheimer, S.; Sasselov, D. [Harvard Smithsonian Center for Astrophysics, 60 Garden st., 02138 MA Cambridge (United States); Segura, A. [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, México (Mexico); Kaltenegger, L., E-mail: srugheimer@cfa.harvard.edu [Carl Sagan Institute, Cornell University, Ithaca, NY 14853 (United States)

    2015-06-10

    The UV environment of a host star affects the photochemistry in the atmosphere, and ultimately the surface UV environment for terrestrial planets and therefore the conditions for the origin and evolution of life. We model the surface UV radiation environment for Earth-sized planets orbiting FGKM stars in the circumstellar Habitable Zone for Earth through its geological evolution. We explore four different types of atmospheres corresponding to an early-Earth atmosphere at 3.9 Gyr ago and three atmospheres covering the rise of oxygen to present-day levels at 2.0 Gyr ago, 0.8 Gyr ago, and modern Earth. In addition to calculating the UV flux on the surface of the planet, we model the biologically effective irradiance, using DNA damage as a proxy for biological damage. We find that a pre-biotic Earth (3.9 Gyr ago) orbiting an F0V star receives 6 times the biologically effective radiation as around the early Sun and 3520 times the modern Earth–Sun levels. A pre-biotic Earth orbiting GJ 581 (M3.5 V) receives 300 times less biologically effective radiation, about 2 times modern Earth–Sun levels. The UV fluxes calculated here provide a grid of model UV environments during the evolution of an Earth-like planet orbiting a range of stars. These models can be used as inputs into photo-biological experiments and for pre-biotic chemistry and early life evolution experiments.

  16. PROCESS FOR SEPARATING AMERICIUM AND CURIUM FROM RARE EARTH ELEMENTS

    Science.gov (United States)

    Baybarz, R.D.; Lloyd, M.H.

    1963-02-26

    This invention relates to methods of separating americium and curium values from rare earth values. In accordance with the invention americium, curium, and rare earth values are sorbed on an anion exchange resin. A major portion of the rare earth values are selectively stripped from the resin with a concentrated aqueous solution of lithium chloride, and americium, curium, and a minor portion of rare earth values are then stripped from the resin with a dilute aqueous solution of lithium chloride. The americium and curium values are further purified by increasing the concentration of lithium chloride in the solution to at least 8 molar and selectively extracting rare earth values from the resulting solution with a monoalkylphosphoric acid. (AEC)

  17. Global land surface albedo maps from MODIS using the Google Earth Engine

    Science.gov (United States)

    Mitraka, Zina; Benas, Nikolaos; Gorelick, Noel; Chrysoulakis, Nektarios

    2016-04-01

    The land surface albedo (LSA) is a critical physical variable, which influences the Earth's climate by affecting the energy budget and distribution in the Earth-atmosphere system. Its role is highly significant in both global and local scales; hence, LSA measurements provide a quantitative means for better constraining global and regional scale climate modelling efforts. The Moderate Resolution Imaging Spectroradiometer (MODIS) sensor, on board NASA's Terra and Aqua platforms, provides the parameters needed for the computation of LSA on an 8-day temporal scale and a variety of spatial scales (ranging between 0.5 - 5 km). This dataset was used here for the LSA estimation and its changes over the study area at 0.5 km spatial resolution. More specifically, the MODIS albedo product was used, which includes both the directional-hemispherical surface reflectance (black-sky albedo) and the bi-hemispherical surface reflectance (white-sky albedo). The LSA was estimated for the whole globe on an 8-day basis for the whole time period covered by MODIS acquisitions (i.e. 2000 until today). To estimate LSA from black-sky and white-sky albedos, the fraction of the diffused radiation is needed, a function of the Aerosol Optical Thickness (AOT). Required AOT information was acquired from the MODIS AOT product at 1̊ × 1̊ spatial resolution. Since LSA also depends on solar zenith angle (SZA), 8-day mean LSA values were computed as averages of corresponding LSA values for representative SZAs covering the 24-hour day. The estimated LSA was analysed in terms of both spatial and seasonal characteristics, while LSA changes during the period examined were assessed. All computation were performed using the Google Earth Engine (GEE). The GEE provided access to all the MODIS products needed for the analysis without the need of searching or downloading. Moreover, the combination of MODIS products in both temporal and spatial terms was fast and effecting using the GEE API (Application

  18. SWOT: The Surface Water and Ocean Topography Mission. Wide- Swath Altimetric Elevation on Earth

    Science.gov (United States)

    Fu, Lee-Lueng (Editor); Alsdorf, Douglas (Editor); Morrow, Rosemary; Rodriguez, Ernesto; Mognard, Nelly

    2012-01-01

    The elevation of the surface of the ocean and freshwater bodies on land holds key information on many important processes of the Earth System. The elevation of the ocean surface, called ocean surface topography, has been measured by conventional nadirlooking radar altimeter for the past two decades. The data collected have been used for the study of large-scale circulation and sea level change. However, the spatial resolution of the observations has limited the study to scales larger than about 200 km, leaving the smaller scales containing substantial kinetic energy of ocean circulation that is responsible for the flux of heat, dissolved gas and nutrients between the upper and the deep ocean. This flux is important to the understanding of the ocean's role in regulatingfuture climate change.The elevation of the water bodies on land is a key parameter required for the computation of storage and discharge of freshwater in rivers, lakes, and wetlands. Globally, the spatial and temporal variability of water storage and discharge is poorly known due to the lack of well-sampled observations. In situ networks measuring river flows are declining worldwide due to economic and political reasons. Conventional altimeter observations suffers from the complexity of multiple peaks caused by the reflections from water, vegetation canopy and rough topography, resulting in much less valid data over land than over the ocean. Another major limitation is the large inter track distance preventing good coverage of rivers and other water bodies.This document provides descriptions of a new measurement technique using radar interferometry to obtain wide-swath measurement of water elevation at high resolution over both the ocean and land. Making this type of measurement, which addresses the shortcomings of conventional altimetry in both oceanographic and hydrologic applications, is the objective of a mission concept called Surface Water and Ocean Topography (SWOT), which was recommended by

  19. Earth

    CERN Document Server

    Carter, Jason

    2017-01-01

    This curriculum-based, easy-to-follow book teaches young readers about Earth as one of the eight planets in our solar system in astronomical terms. With accessible text, it provides the fundamental information any student needs to begin their studies in astronomy, such as how Earth spins and revolves around the Sun, why it's uniquely suitable for life, its physical features, atmosphere, biosphere, moon, its past, future, and more. To enhance the learning experience, many of the images come directly from NASA. This straightforward title offers the fundamental information any student needs to sp

  20. Surface Modification and Surface - Subsurface Exchange Processes on Europa

    Science.gov (United States)

    Phillips, Cynthia B.; Molaro, Jamie; Hand, Kevin P.

    2017-10-01

    The surface of Jupiter’s moon Europa is modified by exogenic processes such as sputtering, gardening, radiolysis, sulfur ion implantation, and thermal processing, as well as endogenic processes including tidal shaking, mass wasting, and the effects of subsurface tectonic and perhaps cryovolcanic activity. New materials are created or deposited on the surface (radiolysis, micrometeorite impacts, sulfur ion implantation, cryovolcanic plume deposits), modified in place (thermal segregation, sintering), transported either vertically or horizontally (sputtering, gardening, mass wasting, tectonic and cryovolcanic activity), or lost from Europa completely (sputtering, plumes, larger impacts). Some of these processes vary spatially, as visible in Europa’s leading-trailing hemisphere brightness asymmetry.Endogenic geologic processes also vary spatially, depending on terrain type. The surface can be classified into general landform categories that include tectonic features (ridges, bands, cracks); disrupted “chaos-type” terrain (chaos blocks, matrix, domes, pits, spots); and impact craters (simple, complex, multi-ring). The spatial distribution of these terrain types is relatively random, with some differences in apex-antiapex cratering rates and latitudinal variation in chaos vs. tectonic features.In this work, we extrapolate surface processes and rates from the top meter of the surface in conjunction with global estimates of transport and resurfacing rates. We combine near-surface modification with an estimate of surface-subsurface (and vice versa) transport rates for various geologic terrains based on an average of proposed formation mechanisms, and a spatial distribution of each landform type over Europa’s surface area.Understanding the rates and mass balance for each of these processes, as well as their spatial and temporal variability, allows us to estimate surface - subsurface exchange rates over the average surface age (~50myr) of Europa. Quantifying the

  1. Surface Energy and Setting Process of Contacting Surfaces

    Directory of Open Access Journals (Sweden)

    M. V. Musokhranov

    2014-01-01

    Full Text Available The paper deals with a challenge in terms of ensuring an accuracy of the relative position of the conjugated surfaces that is to determine a coefficient of friction. To solve it, there is a proposal to use the surface energy, as a tool that influences the contacting parts nature. Presently, energy of the surface layers at best is only stated, but not used in practice.Analysis of the conditions of interaction between two contacting surfaces, such as seizing and setting cannot be explained only from the position of the roughness parameters. It is found that these phenomena are explained by the appearing gripe (setting bridges, which result from the energy of interaction between two or more adjacent surfaces. The emerging phenomenon such as micro welding, i.e. occurring bonds, is caused by the overflow of energy, according to the theory of physics, from the surface with a high level of energy to the surface with the smaller one to balance the system as a whole.The paper shows that through the use of process, controlling the depth of the surface layer and creating a certain structure, the energy level of the material as a whole can be specified. And this will allow us to provide the necessary performance and mechanical properties. It means to create as many gripe bridges as possible to ensure continuous positioning i.e. a fixed connection of the contacting surfaces.It was determined that to increase a value of the friction coefficient, the physical and mechanical properties of the surface layer of the parts material must be taken into account, namely, in the part body accumulate the energy to be consumed for forming the surface.The paper gives recommendations for including the parts of the surface energy in the qualitative indicators of characteristics. This will make a technologist, when routing a process, to choose such operations and modes to provide the designer-specified parameters not only of the accuracy and surface finish, but also of the

  2. Bioadsorption of Rare Earth Elements through Cell Surface Display of Lanthanide Binding Tags.

    Science.gov (United States)

    Park, Dan M; Reed, David W; Yung, Mimi C; Eslamimanesh, Ali; Lencka, Malgorzata M; Anderko, Andrzej; Fujita, Yoshiko; Riman, Richard E; Navrotsky, Alexandra; Jiao, Yongqin

    2016-03-01

    With the increasing demand for rare earth elements (REEs) in many emerging clean energy technologies, there is an urgent need for the development of new approaches for efficient REE extraction and recovery. As a step toward this goal, we genetically engineered the aerobic bacterium Caulobacter crescentus for REE adsorption through high-density cell surface display of lanthanide binding tags (LBTs) on its S-layer. The LBT-displayed strains exhibited enhanced adsorption of REEs compared to cells lacking LBT, high specificity for REEs, and an adsorption preference for REEs with small atomic radii. Adsorbed Tb(3+) could be effectively recovered using citrate, consistent with thermodynamic speciation calculations that predicted strong complexation of Tb(3+) by citrate. No reduction in Tb(3+) adsorption capacity was observed following citrate elution, enabling consecutive adsorption/desorption cycles. The LBT-displayed strain was effective for extracting REEs from the acid leachate of core samples collected at a prospective rare earth mine. Our collective results demonstrate a rapid, efficient, and reversible process for REE adsorption with potential industrial application for REE enrichment and separation.

  3. NASA's Earth Science Data Systems Standards Endorsement Process

    National Research Council Canada - National Science Library

    Ullman, Richard E; Enloe, Yonsook

    2005-01-01

    Starting in January 2004, NASA instituted a set of internal working groups to develop ongoing recommendations for the continuing broad evolution of Earth Science Data Systems development and management within NASA...

  4. Rare Earth Ion-Doped Upconversion Nanocrystals: Synthesis and Surface Modification

    Directory of Open Access Journals (Sweden)

    Hongjin Chang

    2014-12-01

    Full Text Available The unique luminescent properties exhibited by rare earth ion-doped upconversion nanocrystals (UCNPs, such as long lifetime, narrow emission line, high color purity, and high resistance to photobleaching, have made them widely used in many areas, including but not limited to high-resolution displays, new-generation information technology, optical communication, bioimaging, and therapy. However, the inherent upconversion luminescent properties of UCNPs are influenced by various parameters, including the size, shape, crystal structure, and chemical composition of the UCNPs, and even the chosen synthesis process and the surfactant molecules used. This review will provide a complete summary on the synthesis methods and the surface modification strategies of UCNPs reported so far. Firstly, we summarize the synthesis methodologies developed in the past decades, such as thermal decomposition, thermal coprecipitation, hydro/solvothermal, sol-gel, combustion, and microwave synthesis. In the second part, five main streams of surface modification strategies for converting hydrophobic UCNPs into hydrophilic ones are elaborated. Finally, we consider the likely directions of the future development and challenges of the synthesis and surface modification, such as the large-scale production and actual applications, stability, and so on, of the UCNPs.

  5. Image data processing system requirements study. Volume 1: Analysis. [for Earth Resources Survey Program

    Science.gov (United States)

    Honikman, T.; Mcmahon, E.; Miller, E.; Pietrzak, L.; Yorsz, W.

    1973-01-01

    Digital image processing, image recorders, high-density digital data recorders, and data system element processing for use in an Earth Resources Survey image data processing system are studied. Loading to various ERS systems is also estimated by simulation.

  6. Surface transport processes in charged porous media.

    Science.gov (United States)

    Gabitto, Jorge; Tsouris, Costas

    2017-07-15

    Surface transport processes are very important in chemistry, colloidal sciences, engineering, biology, and geophysics. Natural or externally produced charges on surfaces create electrical double layers (EDLs) at the solid-liquid interface. The existence of the EDLs produces several complex processes including bulk and surface transport of ions. In this work, a model is presented to simulate bulk and transport processes in homogeneous porous media comprising big pores. It is based on a theory for capacitive charging by ideally polarizable porous electrodes without Faradaic reactions or specific adsorption of ions. A volume averaging technique is used to derive the averaged transport equations in the limit of thin electrical double layers. Description of the EDL between the electrolyte solution and the charged wall is accomplished using the Gouy-Chapman-Stern (GCS) model. The surface transport terms enter into the average equations due to the use of boundary conditions for diffuse interfaces. Two extra surface transports terms appear in the closed average equations. One is a surface diffusion term equivalent to the transport process in non-charged porous media. The second surface transport term is a migration term unique to charged porous media. The effective bulk and transport parameters for isotropic porous media are calculated solving the corresponding closure problems. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Deposition, adhere and remobilization of radioactive nuclide on surface and materials covered on the earth

    Energy Technology Data Exchange (ETDEWEB)

    Hanabusa, Tatsuo; Chiba, Masaru; Kurita, Susumu; Sato, Junji; Maki, hiroatsu; Okada, Kikuo; Mori, Hideaki [Meteorological Research Inst., Tsukuba, Ibaraki (Japan)

    2000-02-01

    To evaluate the effect of radioactive nuclide released from nuclear installation on human body, new model with retraveling process was developed. This retraveling process was changed by the surface state of the earth, for example, soil, grass (field) and tree. Study method of retraveling of particles adhered on grass and tree into the atmosphere was the following: the relation between particles retraveling rate and wind velocity was observed by a wind tunnel experiment. Then, the retraveling experiment was carried out in the natural environment. The effect of environmental factor on the retraveling rate was studied by comparing two experiments. Then, an experimental equation was derived from these results. We used Ophiopogon japonicus Ker-Gawl, Eurya emarginata Makino and Lycopodium clavatum L. as samples of grass, tree and particles, respectably. On grass, the retraveling rate decreased monotonously at the wind tunnel experiment, but it was changed by time at the experiment in the field. When a light set up in the wind tunnel and the capture rate of particle on the surface of grass was measured, the results showed the capture decreased monotonously under no light. However, when the wind tunnel lighted up well, the capture increase 3 times as much as no light. So that, sun light affected on retraveling of particle. (S.Y.)

  8. Minding the gap: Thinking through spatiotemporal scaling challenges in Earth surface dynamics research

    Science.gov (United States)

    Viles, Heather

    2017-04-01

    Research into the dynamics of Earth's surface is diverse, interdisciplinary and challenging, but also an important geoscience contribution to understanding human-landscape interactions in the Anthropocene. Scale issues often thwart our ability to provide answers to important questions of how the Earth's surface has changed in the past and may change in the future. This paper reflects on four major common components of Earth surface dynamics research projects (i.e. how to identify and frame a research question, how to design a study to answer that question, difficulties with data, how to use data to answer the question) and identifies the most important spatiotemporal scale challenges. A case study of an experimental study of rock breakdown in arid environments is used to illustrate these challenges, and to demonstrate the importance of clear conceptualisation and critical thinking in overcoming them.

  9. Effect of the Earth's rotation on subduction processes

    Science.gov (United States)

    Levin, B. W.; Rodkin, M. V.; Sasorova, E. V.

    2017-09-01

    The role played by the Earth's rotation is very important in problems of physics of the atmosphere and ocean. The importance of inertia forces is traditionally estimated by the value of the Rossby number: if this parameter is small, the Coriolis force considerably affects the character of movements. In the case of convection in the Earth's mantle and movements of lithospheric plates, the Rossby number is quite small; therefore, the effect of the Coriolis force is reflected in the character of movements of the lithospheric plates. Analysis of statistical data on subduction zones verifies this suggestion.

  10. How can we understand the global distribution of the solar cycle signal on the Earth's surface?

    Directory of Open Access Journals (Sweden)

    K. Kodera

    2016-10-01

    Full Text Available To understand solar cycle signals on the Earth's surface and identify the physical mechanisms responsible, surface temperature variations from observations as well as climate model data are analysed to characterize their spatial structure. The solar signal in the annual mean surface temperature is characterized by (i mid-latitude warming and (ii no overall tropical warming. The mid-latitude warming during solar maxima in both hemispheres is associated with a downward penetration of zonal mean zonal wind anomalies from the upper stratosphere during late winter. During the Northern Hemisphere winter this is manifested by a modulation of the polar-night jet, whereas in the Southern Hemisphere, the upper stratospheric subtropical jet plays the major role. Warming signals are particularly apparent over the Eurasian continent and ocean frontal zones, including a previously reported lagged response over the North Atlantic. In the tropics, local warming occurs over the Indian and central Pacific oceans during high solar activity. However, this warming is counterbalanced by cooling over the cold tongue sectors in the southeastern Pacific and the South Atlantic, and results in a very weak zonally averaged tropical mean signal. The cooling in the ocean basins is associated with stronger cross-equatorial winds resulting from a northward shift of the ascending branch of the Hadley circulation during solar maxima. To understand the complex processes involved in the solar signal transfer, results of an idealized middle atmosphere–ocean coupled model experiment on the impact of stratospheric zonal wind changes are compared with solar signals in observations. Model integration of 100 years of strong or weak stratospheric westerly jet condition in winter may exaggerate long-term ocean feedback. However, the role of ocean in the solar influence on the Earth's surface can be better seen. Although the momentum forcing differs from that of solar radiative forcing

  11. The role of cosmic rays in the Earth's atmospheric processes

    Indian Academy of Sciences (India)

    The effect of cosmic rays on climate could be in three ways: (a) through changes in the concentration of cloud ..... fore, during and after cloud-to-ground lighting flashes of either negative or positive polarity, and also following .... and (iii) understanding the electromagnetic propagation in the Earth's environ- ment. In fact, high ...

  12. From Bursts to Back-Projection: Signal Processing Techniques for Earth and Planetary Observing Radars

    Science.gov (United States)

    Rosen, Paul A.

    2012-01-01

    Discusses: (1) JPL Radar Overview and Historical Perspective (2) Signal Processing Needs in Earth and Planetary Radars (3) Examples of Current Systems and techniques (4) Future Perspectives in signal processing for radar missions

  13. Influence of the topography of the surface of the Earth on vertical sounding of the temperature profile

    Directory of Open Access Journals (Sweden)

    A. Pfister

    Full Text Available Atmospheric temperature and humidity fields as well as information on other meteorological parameters are nowadays retrieved from radiance measurements recorded by operational meteorological satellites. Up to now, the inversion procedures used only take into account crude information on the topography of the Earth's surface. However, the applied radiative transfer codes have to consider the Earth's surface as the lower boundary of the atmospheric model and, therefore, need a more precise mean elevation and a classification of the roughness of the Earth's surface. The influence of the topography of the Earth surface on retrieved temperature profiles is studied by using a physico-statistical inversion method. An objective analysis is made of the more precise mean elevation and derivation of roughness parameters using a new high-resolution digital elevation model (DEM with a resolution of 500 m×500 m. By means of a geomorphological process and a newly developed topography rejection test, areas with a high surface roughness are localized and singled out. The influence of topography on the retrieved temperature profiles is illustrated by case studies. Changes are found predominantly in areas with a high variation of topography. Using the new high-resolution DEM and the topography rejection test, the geographical position of the calculated temperature profiles tends to be shifted towards areas with a small vertical variation of topography. The mean elevation determined by the new elevation model better characterizes the area observed. Hence, the temperature profiles can be calculated down to lower atmospheric levels. Furthermore, a guess profile better describing the atmospheric situation is selected by the more precise elevation. In addition, the temperature profiles obtained near the coast are improved considerably by the more precise determination of the surface property `sea' and `land,' respectively. Integration of an

  14. Influence of the topography of the surface of the Earth on vertical sounding of the temperature profile

    Directory of Open Access Journals (Sweden)

    A. Pfister

    1995-03-01

    Full Text Available Atmospheric temperature and humidity fields as well as information on other meteorological parameters are nowadays retrieved from radiance measurements recorded by operational meteorological satellites. Up to now, the inversion procedures used only take into account crude information on the topography of the Earth's surface. However, the applied radiative transfer codes have to consider the Earth's surface as the lower boundary of the atmospheric model and, therefore, need a more precise mean elevation and a classification of the roughness of the Earth's surface. The influence of the topography of the Earth surface on retrieved temperature profiles is studied by using a physico-statistical inversion method. An objective analysis is made of the more precise mean elevation and derivation of roughness parameters using a new high-resolution digital elevation model (DEM with a resolution of 500 m×500 m. By means of a geomorphological process and a newly developed topography rejection test, areas with a high surface roughness are localized and singled out. The influence of topography on the retrieved temperature profiles is illustrated by case studies. Changes are found predominantly in areas with a high variation of topography. Using the new high-resolution DEM and the topography rejection test, the geographical position of the calculated temperature profiles tends to be shifted towards areas with a small vertical variation of topography. The mean elevation determined by the new elevation model better characterizes the area observed. Hence, the temperature profiles can be calculated down to lower atmospheric levels. Furthermore, a guess profile better describing the atmospheric situation is selected by the more precise elevation. In addition, the temperature profiles obtained near the coast are improved considerably by the more precise determination of the surface property `sea' and `land,' respectively. Integration of an independent physical

  15. Process For Patterning Dispenser-Cathode Surfaces

    Science.gov (United States)

    Garner, Charles E.; Deininger, William D.

    1989-01-01

    Several microfabrication techniques combined into process cutting slots 100 micrometer long and 1 to 5 micrometer wide into tungsten dispenser cathodes for traveling-wave tubes. Patterned photoresist serves as mask for etching underlying aluminum. Chemically-assisted ion-beam etching with chlorine removes exposed parts of aluminum layer. Etching with fluorine or chlorine trifluoride removes tungsten not masked by aluminum layer. Slots enable more-uniform low-work function coating dispensed to electron-emitting surface. Emission of electrons therefore becomes more uniform over cathode surface.

  16. Global water cycle and the coevolution of the Earth's interior and surface environment

    Science.gov (United States)

    Korenaga, Jun; Planavsky, Noah J.; Evans, David A. D.

    2017-04-01

    The bulk Earth composition contains probably less than 0.3% of water, but this trace amount of water can affect the long-term evolution of the Earth in a number of different ways. The foremost issue is the occurrence of plate tectonics, which governs almost all aspects of the Earth system, and the presence of water could either promote or hinder the operation of plate tectonics, depending on where water resides. The global water cycle, which circulates surface water into the deep mantle and back to the surface again, could thus have played a critical role in the Earth's history. In this contribution, we first review the present-day water cycle and discuss its uncertainty as well as its secular variation. If the continental freeboard has been roughly constant since the Early Proterozoic, model results suggest long-term net water influx from the surface to the mantle, which is estimated to be 3-4.5×1014 g yr-1 on the billion years time scale. We survey geological and geochemical observations relevant to the emergence of continents above the sea level as well as the nature of Precambrian plate tectonics. The global water cycle is suggested to have been dominated by regassing, and its implications for geochemical cycles and atmospheric evolution are also discussed. This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'.

  17. Global water cycle and the coevolution of the Earth's interior and surface environment.

    Science.gov (United States)

    Korenaga, Jun; Planavsky, Noah J; Evans, David A D

    2017-05-28

    The bulk Earth composition contains probably less than 0.3% of water, but this trace amount of water can affect the long-term evolution of the Earth in a number of different ways. The foremost issue is the occurrence of plate tectonics, which governs almost all aspects of the Earth system, and the presence of water could either promote or hinder the operation of plate tectonics, depending on where water resides. The global water cycle, which circulates surface water into the deep mantle and back to the surface again, could thus have played a critical role in the Earth's history. In this contribution, we first review the present-day water cycle and discuss its uncertainty as well as its secular variation. If the continental freeboard has been roughly constant since the Early Proterozoic, model results suggest long-term net water influx from the surface to the mantle, which is estimated to be 3-4.5×1014 g yr-1 on the billion years time scale. We survey geological and geochemical observations relevant to the emergence of continents above the sea level as well as the nature of Precambrian plate tectonics. The global water cycle is suggested to have been dominated by regassing, and its implications for geochemical cycles and atmospheric evolution are also discussed.This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'. © 2017 The Author(s).

  18. Thermonuclear Processes as a Principal Source of the Earth's Internal Energy

    Science.gov (United States)

    Terez, E. I.; Terez, I. E.

    2011-12-01

    A cosmological model of the formation of the Solar System is presented. It is shown that the main source of the Earth's energy is delivered from the thermonuclear processes in the inner Earth's core consisting of metallic hydrides. Several theoretical studies showed that under low temperature (Tspringerlink.com/content/jn2576q7727q0034

  19. Some environmental problems and their satellite monitoring. [anthropogenic modifications of earth surface

    Science.gov (United States)

    Otterman, J.

    1975-01-01

    Anthropogenic modification of the earth's surface is discussed in two problem areas: (1) land use changes and overgrazing, and how it affects albedo and land surface-atmosphere interactions, and (2) water and land surface pollution, especially oil slicks. A literature survey evidences the importance of these problems. The need for monitoring is stressed, and it is suggested that with some modifications to the sensors, ERTS (Landsat) series satellites can provide approximate monitoring information. The European Landsat receiving station in Italy will facilitate data collection for the tasks described.

  20. Crystal surface integrity and diffusion measurements on Earth and planetary materials

    Science.gov (United States)

    Watson, E. B.; Cherniak, D. J.; Thomas, J. B.; Hanchar, J. M.; Wirth, R.

    2016-09-01

    Characterization of diffusion behavior in minerals is key to providing quantitative constraints on the ages and thermal histories of Earth and planetary materials. Laboratory experiments are a vital source of the needed diffusion measurements, but these can pose challenges because the length scales of diffusion achievable in a laboratory time are commonly less than 1 μm. An effective strategy for dealing with this challenge is to conduct experiments involving inward diffusion of the element of interest from a surface source, followed by quantification of the resulting diffusive-uptake profile using a high-resolution depth-profiling technique such as Rutherford backscattering spectroscopy (RBS), nuclear reaction analysis (NRA), or ion microprobe (SIMS). The value of data from such experiments is crucially dependent on the assumption that diffusion in the near-surface of the sample is representative of diffusion in the bulk material. Historical arguments suggest that the very process of preparing a polished surface for diffusion studies introduces defects-in the form of dislocations and cracks-in the outermost micrometer of the sample that make this region fundamentally different from the bulk crystal in terms of its diffusion properties. Extensive indirect evidence suggests that, in fact, the near-surface region of carefully prepared samples is no different from the bulk crystal in terms of its diffusion properties. A direct confirmation of this conclusion is nevertheless clearly important. Here we use transmission electron microscopy to confirm that the near-surface regions of olivine, quartz and feldspar crystals prepared using careful polishing protocols contain no features that could plausibly affect diffusion. This finding does not preclude damage to the mineral structure from other techniques used in diffusion studies (e.g., ion implantation), but even in this case the role of possible structural damage can be objectively assessed and controlled. While all

  1. Adsorption of paraquat on the physically activated bleaching earth waste from soybean oil processing plant.

    Science.gov (United States)

    Tsai, W T; Chen, C H; Yang, J M

    2002-09-01

    A series of regeneration experiments with physical activation were carried out on bleaching earth waste from the soybean refining process in a rotary reactor. The influence of activation parameters on the spent clay by varying the holding time of 1 to approximately 4 hours and temperature of 700 to approximately 900 degrees C was determined. The variations of pore properties as well as the change of chemical characteristics in the resulting solids were also studied. Results showed that the resulting samples were type IV with hysteresis loops corresponding to type H3 from nitrogen adsorption-desorption isotherms, indicating slit-shaped mesoporous characteristics. However, the regenerated clays had smaller surface areas (70 to approximately 117 m2/g) than that (245 m2/g) of fresh bleaching earth. Under the physical activation conditions investigated, the holding time of 1 hour and temperature of 700 degrees C were found to be optimal conditions for producing mesoporous clay with physical activation. The adsorption of paraquat on regenerated sample was also evaluated. The isotherm showed that the regenerated sample still had a high affinity for this herbicide. Thus, the regeneration of this agro-industrial waste is one option for utilizing the clay resource, and it may be used for water treatment applications to remove organic contaminants.

  2. Surface fractal dimensions and textural properties of mesoporous alkaline-earth hydroxyapatites

    Energy Technology Data Exchange (ETDEWEB)

    Vilchis-Granados, J. [Instituto Nacional de Investigaciones Nucleares, Departamento de Química, A.P. 18-1027, Col. Escandón, Delegación Miguel Hidalgo, C.P. 11801, México, DF (Mexico); Universidad Autónoma del Estado de México, Facultad de Química, Av. Paseo Colón esquina con Paseo Tollocan s/n Toluca, México (Mexico); Granados-Correa, F., E-mail: francisco.granados@inin.gob.mx [Instituto Nacional de Investigaciones Nucleares, Departamento de Química, A.P. 18-1027, Col. Escandón, Delegación Miguel Hidalgo, C.P. 11801, México, DF (Mexico); Barrera-Díaz, C.E. [Universidad Autónoma del Estado de México, Facultad de Química, Av. Paseo Colón esquina con Paseo Tollocan s/n Toluca, México (Mexico)

    2013-08-15

    This work examines the surface fractal dimensions (D{sub f}) and textural properties of three different alkaline-earth hydroxyapatites. Calcium, strontium and barium hydroxyapatite compounds were successfully synthesized via chemical precipitation method and characterized using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectrometry, Fourier transform infrared spectroscopy, and N{sub 2}-physisorption measurements. Surface fractal dimensions were determined using single N{sub 2}-adsorption/desorption isotherms method to quantify the irregular surface of as-prepared compounds. The obtained materials were also characterized through their surface hydroxyl group content, determined by the mass titration method. It was found that the D{sub f} values for the three materials covered the range of 0.77 ± 0.04–2.33 ± 0.11; these results indicated that the materials tend to have smooth surfaces, except the irregular surface of barium hydroxyapatite. Moreover, regarding the synthesized calcium hydroxyapatite exhibited better textural properties compared with the synthesized strontium and barium hydroxyapatites for adsorbent purposes. However, barium hydroxyapatite shows irregular surface, indicating a high population of active sites across the surface, in comparison with the others studied hydroxyapatites. Finally, the results showed a linear correlation between the surface hydroxyl group content at the external surface of materials and their surface fractal dimensions.

  3. Earth radiation budget from a surface perspective and its representation in CMIP5 models

    Science.gov (United States)

    Wild, M.

    2012-04-01

    The genesis and evolution of Earth's climate is largely regulated by the global energy balance. Despite the central importance of the global energy balance for the climate system and climate change, substantial uncertainties still exist in the quantification of its different components, and their representation in climate models (e.g., Wild et al. 1998 Clim. Dyn., Wild 2008 Tellus). While the net radiative energy flow in and out of the climate system at the top of atmosphere (TOA) is known with considerable accuracy from new satellite programs such as CERES, much less is known about the energy distribution within the climate system and at the Earth surface. Here we use direct surface observations from the Baseline Surface Radiation Network (BSRN) and the Global Energy Balance Archive (GEBA) to provide better constraints on the surface radiative components as well as to investigate their temporal changes. We analyze radiation budgets of the latest generation of global climate models as used in the Coupled Model Intercomparison Project Phase 5 (CMIP5) and in the upcoming Fifth IPCC assessment report (IPCCAR5). Compared to a comprehensive set of surface observations, the CMIP5 models overestimate the shortwave radiation incident at the surface by 5-10 Wm-2 on average, due to a lack of absorption in the atmosphere. This suggests that the best estimate for the global mean absorbed shortwave radiation at the surface should be lower than the simulated estimates, which are on average slightly below 170 Wm-2, so that a value of no more than 160 Wm-2 might be the most realistic estimate for the global mean absorbed shortwave radiation at the surface. In contrast, the longwave downward radiation at the surface is underestimated by a similar amount in these models, suggesting that the best estimate for the global mean downward longwave radiation should be rather around 345 Wm-2 than the model average of 338 Wm-2. There is further increasing evidence from the direct

  4. A Revised Estimate of Earth's Surface Heat Flux: 47TW ± 2TW

    Science.gov (United States)

    Davies, J.; Davies, R.

    2011-12-01

    Earth's surface heat flux provides a fundamental constraint on solid Earth dynamics. However, deriving an estimate of the total surface heat flux is complex, due to the inhomogeneous distribution of heat flow measurements and difficulties in measuring heat flux in young oceanic crust, arising due to hydrothermal circulation. We derive a revised estimate of Earth's surface heat flux using a database of 38347 measurements (provided by G. Laske and G. Masters), representing a 55% increase on the number of measurements used previously, and the methods of Geographical Information Science (GIS) (Davies & Davies, 2010). To account for hydrothermal circulation in young oceanic crust, we use a model estimate of the heat flux, following the work of Jaupart et al., 2007; while for the rest of the globe, in an attempt to overcome the inhomogeneous distribution of measurements, we develop an average for different geological units. Two digital geology data sets are used to define the global geology: (i) continental geology - Hearn et al., 2003; and (ii) the global data-set of CCGM - Commission de la Carte Géologique du Monde, 2000. This leads to > 93,000 polygons defining Earth's geology. To limit the influence of clustering, we intersect the geology polygons with a 1 by 1 degree (at the equator) equal area grid. For each geology class the average heat flow in the resulting polygons is evaluated. The contribution of that geology class to the global surface heat flow is derived by multiplying the estimated surface heat flux with the area of that geology class. The total surface heat flow contributions of all the geology classes are summed. For Antarctica we use an estimate based on depth to Curie temperature and include a 1TW contribution from hot-spots in young ocean age. Geology classes with less than 50 readings are excluded. The raw data suggests that this method of correlating heat flux with geology has some power. Our revised estimate for Earth's global surface heat flux

  5. Assessment of strain effect of strong-motion (focus zones of earthquakes on earth's surface displacement

    Directory of Open Access Journals (Sweden)

    Kh.L. Khamidov

    2017-01-01

    Full Text Available Strain effect of focal zones on fore-seismic displacements of earth's surface is studied in the paper for real conditions of focus zones of the earthquakes. The width of the interval of maximum displacements is determined by the conditions of potential focus of tectonic earthquake. The solution of elastic problem for half-space with soft inclusion is used. Calculations are conducted also by empirical formulas, obtained for similar stress states. Possible radius of the zone of maximum revelation of strain anomaly is determined on the basis of the growth of rupture scale and change in heterogeneity volume. It is shown that obtained expression covers a wider range of magnitude variations with consideration of the interval of scale change in upcoming rupture-forming zone. In the example of Tashkent (1966 and Gazli (1984 strong ground motions, an analysis of possible strains occurrence on the Earth's surface was conducted.

  6. The Natural Charge On The Surface Of The Earth | Mamah | Global ...

    African Journals Online (AJOL)

    The natural electric charge or its artificial analogue as the fundamental unit of exploration has been fundamentally derived and compared for both the equatorial region and the polar region. The ratio of the unit charge on the surface of the earth at the equatorial region (ω ± ω0) = 0.59 rad where ω0 = 1.65; to that at the polar ...

  7. A New Physical Model to Estimate Solar Irradiance Componets on the Earth's Surface from Satellite Images

    Science.gov (United States)

    Cony, Marco, ,, Dr.; Wiesenberg, Ralf, ,, Dr.; Fernandéz, Irene; Jimenez, Marta

    2017-04-01

    The present study describes a new model designed to estimate the incident solar radiation at the Earth's surface from geostationary satellites images (AFASat). In this new physical model proposed, the effect of Rayleigh scattering, aerosols and Earth's surface topography are taken into account. Water vapor absorption is also introduced by means of its climatological effects on shortwave radiation. Cloud albedo, ground albedo and absorption are derived from brightness measurements on the assumption that they both are linearly related to the brightness. However, this simple consideration applied to individual images elements represents quite accurately the bulk effect of clouds and reflectance. AFASat model uses the Heliosat-3 method and add others environmental factors to estimate with relative precision the solar radiation that arrives at the Earth's surface. Comparisons with daily radiation measurements from ground data station located in Europe, Africa and India (BSRN) showed that the satellite estimates were, on the average, within 2% of the ground measurements for global horizontal irradiance and less than 7% for direct normal irradiance. The hourly variations monitored by the satellite also followed very closely the variations measured on the ground. This study has shown that model is sufficient for the determination of the incident solar radiation when the high spatial and temporal coverage of a geostationary satellite is used. The AFASat is highly appropriate for such those projects that required an analysis of the solar resource assessment as such as TMY report (Typical Meteorological Year).

  8. Release characteristics of alkali and alkaline earth metallic species during biomass pyrolysis and steam gasification process.

    Science.gov (United States)

    Long, Jiang; Song, Hu; Jun, Xiang; Sheng, Su; Lun-Shi, Sun; Kai, Xu; Yao, Yao

    2012-07-01

    Investigating the release characteristics of alkali and alkaline earth metallic species (AAEMs) is of potential interest because of AAEM's possible useful service as catalysts in biomass thermal conversion. In this study, three kinds of typical Chinese biomass were selected to pyrolyse and their chars were subsequently steam gasified in a designed quartz fixed-bed reactor to investigate the release characteristics of alkali and alkaline earth metallic species (AAEMs). The results indicate that 53-76% of alkali metal and 27-40% of alkaline earth metal release in pyrolysis process, as well as 12-34% of alkali metal and 12-16% of alkaline earth metal evaporate in char gasification process, and temperature is not the only factor to impact AAEMs emission. The releasing characteristics of AAEMs during pyrolysis and char gasification process of three kinds of biomass were discussed in this paper. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Biological processes on glacier and ice sheet surfaces

    Science.gov (United States)

    Stibal, Marek; Šabacká, Marie; Žárský, Jakub

    2012-11-01

    Glaciers and ice sheets are melting in response to climate warming. Whereas the physical behaviour of glaciers has been studied intensively, the biological processes associated with glaciers and ice sheets have received less attention. Nevertheless, field observations and laboratory experiments suggest that biological processes that occur on the surface of glaciers and ice sheets -- collectively termed supraglacial environments -- can affect the physical behaviour of glaciers by changing surface reflectivity. Furthermore, supraglacial cyanobacteria and algae capture carbon dioxide from the atmosphere and convert it into organic matter. Supraglacial microbes break down this material, together with organic matter transported from further afield, and generate carbon dioxide that is released back into the atmosphere. The balance between these two processes will determine whether a glacier is a net sink or source of carbon dioxide. In general, ice sheet interiors seem to function as sinks, whereas ice sheet edges and small glaciers act as a source. Meltwaters flush microbially modified organic matter and pollutants out of the glacier, with potential consequences for downstream ecosystems. We conclude that microbes living on glaciers and ice sheets are an integral part of both the glacial environment and the Earth's ecosystem.

  10. Digital image processing for the earth resources technology satellite data.

    Science.gov (United States)

    Will, P. M.; Bakis, R.; Wesley, M. A.

    1972-01-01

    This paper discusses the problems of digital processing of the large volumes of multispectral image data that are expected to be received from the ERTS program. Correction of geometric and radiometric distortions are discussed and a byte oriented implementation is proposed. CPU timing estimates are given for a System/360 Model 67, and show that a processing throughput of 1000 image sets per week is feasible.

  11. Towards understanding how surface life can affect interior geological processes: a non-equilibrium thermodynamics approach

    Science.gov (United States)

    Dyke, J. G.; Gans, F.; Kleidon, A.

    2011-06-01

    Life has significantly altered the Earth's atmosphere, oceans and crust. To what extent has it also affected interior geological processes? To address this question, three models of geological processes are formulated: mantle convection, continental crust uplift and erosion and oceanic crust recycling. These processes are characterised as non-equilibrium thermodynamic systems. Their states of disequilibrium are maintained by the power generated from the dissipation of energy from the interior of the Earth. Altering the thickness of continental crust via weathering and erosion affects the upper mantle temperature which leads to changes in rates of oceanic crust recycling and consequently rates of outgassing of carbon dioxide into the atmosphere. Estimates for the power generated by various elements in the Earth system are shown. This includes, inter alia, surface life generation of 264 TW of power, much greater than those of geological processes such as mantle convection at 12 TW. This high power results from life's ability to harvest energy directly from the sun. Life need only utilise a small fraction of the generated free chemical energy for geochemical transformations at the surface, such as affecting rates of weathering and erosion of continental rocks, in order to affect interior, geological processes. Consequently when assessing the effects of life on Earth, and potentially any planet with a significant biosphere, dynamical models may be required that better capture the coupled nature of biologically-mediated surface and interior processes.

  12. Towards understanding how surface life can affect interior geological processes: a non-equilibrium thermodynamics approach

    Directory of Open Access Journals (Sweden)

    J. G. Dyke

    2011-06-01

    Full Text Available Life has significantly altered the Earth's atmosphere, oceans and crust. To what extent has it also affected interior geological processes? To address this question, three models of geological processes are formulated: mantle convection, continental crust uplift and erosion and oceanic crust recycling. These processes are characterised as non-equilibrium thermodynamic systems. Their states of disequilibrium are maintained by the power generated from the dissipation of energy from the interior of the Earth. Altering the thickness of continental crust via weathering and erosion affects the upper mantle temperature which leads to changes in rates of oceanic crust recycling and consequently rates of outgassing of carbon dioxide into the atmosphere. Estimates for the power generated by various elements in the Earth system are shown. This includes, inter alia, surface life generation of 264 TW of power, much greater than those of geological processes such as mantle convection at 12 TW. This high power results from life's ability to harvest energy directly from the sun. Life need only utilise a small fraction of the generated free chemical energy for geochemical transformations at the surface, such as affecting rates of weathering and erosion of continental rocks, in order to affect interior, geological processes. Consequently when assessing the effects of life on Earth, and potentially any planet with a significant biosphere, dynamical models may be required that better capture the coupled nature of biologically-mediated surface and interior processes.

  13. Thermal inertia as an indicator of rockiness variegation on near-Earth asteroid surfaces

    Science.gov (United States)

    Ali-Lagoa, Victor; Delbo, Marco; Hanus, Josef

    2016-10-01

    Determining key physical properties of asteroids such as sizes and albedos or reflectance spectra is crucial to understand their origins and the processes that they have undergone during their evolution. In particular, one of the aims of NEOShield-2 project, funded by the European Union's Horizon 2020 Research and Innovation programme, is to physically characterize small near Earth asteroids (NEA) in an effort to determine effective mitigation strategies in case of impact with our planet [Harris et al. 2013 2013AcAau,90,80H].We performed thermophysical modelling of NEAs, such as (1685) Toro, and potentially hazardous asteroids (PHAs), such as (33342) 1998 WT24. In addition to size, thermophysical models (TPM) of asteroids can constrain the surface thermal inertia, which is related to the material composition and physical nature, namely its "rockiness" or typical size of the particles on its surface. These have observable effects on the surface temperature distribution as a function of time and thus on the thermal infrared fluxes we observe, to which we can fit our model.In the case of WT24, its thermal inertia has been previously constrained to be in the range 100-300 SI units [Harris et al. 2007, Icarus 188, 414H]. But this was based on a spherical shape model approximation since no shape model was available by the time. Such a low thermal inertia value seems in disagreement with a relatively high metal content of the enstatite chondrites, the meteorite type to which WT24, classified as an E-type [Lazzarin et al. 2004 A&A 425L, 25L], has been spectrally associated. Using a three-dimensional model and spin vector based on radar observations [Busch et al. 2008 Icarus 197, 375B], our TPM produces a higher best-fitting value of the thermal inertia. We also find the intriguing possibility that the hemisphere of WT24 dominated by concave terrains, possibly be the result of an impact crater, has a higher thermal inertia. This would be similar to the case of our Moon

  14. Earth materials and earth dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, K; Shankland, T. [and others

    2000-11-01

    In the project ''Earth Materials and Earth Dynamics'' we linked fundamental and exploratory, experimental, theoretical, and computational research programs to shed light on the current and past states of the dynamic Earth. Our objective was to combine different geological, geochemical, geophysical, and materials science analyses with numerical techniques to illuminate active processes in the Earth. These processes include fluid-rock interactions that form and modify the lithosphere, non-linear wave attenuations in rocks that drive plate tectonics and perturb the earth's surface, dynamic recrystallization of olivine that deforms the upper mantle, development of texture in high-pressure olivine polymorphs that create anisotropic velocity regions in the convecting upper mantle and transition zone, and the intense chemical reactions between the mantle and core. We measured physical properties such as texture and nonlinear elasticity, equation of states at simultaneous pressures and temperatures, magnetic spins and bonding, chemical permeability, and thermal-chemical feedback to better characterize earth materials. We artificially generated seismic waves, numerically modeled fluid flow and transport in rock systems and modified polycrystal plasticity theory to interpret measured physical properties and integrate them into our understanding of the Earth. This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL).

  15. Surface reflectivity climatologies from UV to NIR determined from Earth observations by GOME-2 and SCIAMACHY

    Science.gov (United States)

    Tilstra, L. G.; Tuinder, O. N. E.; Wang, P.; Stammes, P.

    2017-04-01

    The primary goal of this paper is to introduce two new surface reflectivity climatologies. The two databases contain the Lambertian-equivalent reflectivity (LER) of the Earth's surface, and they are meant to support satellite retrieval of trace gases and of cloud and aerosol information. The surface LER databases are derived from the Global Ozone Monitoring Experiment (GOME)-2 and Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) instruments and can be considered as improved and extended descendants of earlier surface LER climatologies based on the Total Ozone Mapping Spectrometer (TOMS), GOME-1, and Ozone Monitoring Instrument (OMI) instruments. The GOME-2 surface LER database consists of 21 wavelength bands that span the wavelength range from 335 to 772 nm. The SCIAMACHY surface LER database covers the wavelength range between 335 and 1670 nm in 29 wavelength bands. The two databases are made for each month of the year, and their spatial resolution is 1° × 1°. In this paper we present the methods that are used to derive the surface LER; we analyze the spatial and temporal behavior of the surface LER fields and study the amount of residual cloud contamination in the databases. For several surface types we analyze the spectral surface albedo and the seasonal variation. When compared to the existing surface LER databases, both databases are found to perform well. As an example of possible application of the databases we study the performance of the Fast Retrieval Scheme for Clouds from the Oxygen A-band (FRESCO) cloud information retrieval when it is equipped with the new surface albedo databases. We find considerable improvements. The databases introduced here can not only improve retrievals from GOME-2 and SCIAMACHY but also support those from other instruments, such as TROPOspheric Monitoring Instrument (TROPOMI), to be launched in 2017.

  16. Dusty plasma processes in Earth's polar summer mesosphere

    Science.gov (United States)

    Popel, S. I.; Dubinsky, A. Yu.; Dubinsky

    2013-08-01

    A self-consistent model for the description of dusty plasma structures, such as noctilucent clouds (NLC) and polar mesosphere summer echoes (PMSE), which are frequently grouped together under the common term polar mesospheric clouds, is presented. The model takes into account the processes of condensation of water vapor, ionization, recombination, action of solar radiation, sedimentation, dust particle growth, dust particle charging, electric fields, etc. Using the model, we explain the basic data of observations on the behavior of charged component in polar summer mesosphere. Furthermore, we show the influence of initial distributions of fine particles as well as that of the processes of condensation and water molecule absorption by fine particles on the formation of NLC and PMSE. We also illustrate the possibility of the formation of layered structure and sharp boundaries of NLC.

  17. Mathematical Modeling of Electrodynamics Near the Surface of Earth and Planetary Water Worlds

    Science.gov (United States)

    Tyler, Robert H.

    2017-01-01

    An interesting feature of planetary bodies with hydrospheres is the presence of an electrically conducting shell near the global surface. This conducting shell may typically lie between relatively insulating rock, ice, or atmosphere, creating a strong constraint on the flow of large-scale electric currents. All or parts of the shell may be in fluid motion relative to main components of the rotating planetary magnetic field (as well as the magnetic fields due to external bodies), creating motionally-induced electric currents that would not otherwise be present. As such, one may expect distinguishing features in the types of electrodynamic processes that occur, as well as an opportunity for imposing specialized mathematical methods that efficiently address this class of application. The purpose of this paper is to present and discuss such specialized methods. Specifically, thin-shell approximations for both the electrodynamics and fluid dynamics are combined to derive simplified mathematical formulations describing the behavior of these electric currents as well as their associated electric and magnetic fields. These simplified formulae allow analytical solutions featuring distinct aspects of the thin-shell electrodynamics in idealized cases. A highly efficient numerical method is also presented that is useful for calculations under inhomogeneous parameter distributions. Finally, the advantages as well as limitations in using this mathematical approach are evaluated. This evaluation is presented primarily for the generic case of bodies with water worlds or other thin spherical conducting shells. More specific discussion is given for the case of Earth, but also Europa and other satellites with suspected oceans.

  18. Rare and Rare-Earth Metals in Coal Processing Waste

    Directory of Open Access Journals (Sweden)

    Cherkasova Tatiana

    2017-01-01

    Full Text Available An urgent issue for power plants operating on solid fuels (coal is the issue of utilization or use of accumulated production waste - ash and slag materials - in the related production. Ash-slag materials are classified as “waste”, usually grade 5; tens of millions of tons of them being pro-duced annually in the Kemerovo region, which threatens the ecology of the region. At the same time, ash and slag is a very promising raw material. The use of this material as a base for the final product allows us to signifi-cantly expand the possibilities of using coal. The most widespread is the system of ash and slag involving in construction or as a replacement for sand in road construction, or as an additive to building mixtures. However, there are both industrially valuable and environmentally dangerous ele-ments in ash-slag materials. Ash-slag materials can be considered as inde-pendent ore deposits located on the surface and requiring the costs of their extraction.

  19. Rare and Rare-Earth Metals in Coal Processing Waste

    Science.gov (United States)

    Cherkasova, Tatiana; Cherkasova, Elizaveta; Tikhomirova, Anastasia; Bobrovni-kova, Alyona; Goryunova, Irina

    2017-11-01

    An urgent issue for power plants operating on solid fuels (coal) is the issue of utilization or use of accumulated production waste - ash and slag materials - in the related production. Ash-slag materials are classified as "waste", usually grade 5; tens of millions of tons of them being pro-duced annually in the Kemerovo region, which threatens the ecology of the region. At the same time, ash and slag is a very promising raw material. The use of this material as a base for the final product allows us to signifi-cantly expand the possibilities of using coal. The most widespread is the system of ash and slag involving in construction or as a replacement for sand in road construction, or as an additive to building mixtures. However, there are both industrially valuable and environmentally dangerous ele-ments in ash-slag materials. Ash-slag materials can be considered as inde-pendent ore deposits located on the surface and requiring the costs of their extraction.

  20. Why did life develop on the surface of the Earth in the Cambrian?

    Directory of Open Access Journals (Sweden)

    Carlo Doglioni

    2016-11-01

    Full Text Available Life was limited for most of Earth's history, remaining at a primitive stage and mostly marine until about 0.55 Ga. In the Paleozoic, life eventually exploded and colonized the continental realm. Why had there been such a long period of delayed evolution of life? Early life was dominated by Archaea and Bacteria, which can survive ionizing radiation better than other organisms. The magnetic field preserves the atmosphere, which is the main shield of UV radiation. We explore the hypothesis that the Cambrian explosion of life could have been enabled by the increase of the magnetic field dipole intensity due to the solidification of the inner core, caused by the cooling of the Earth, and the concomitant decrease with time of the high-energy solar flux since the birth of the solar system. Therefore, the two phenomena could be responsible for the growth and thickening of the atmosphere and the development of land surface life.

  1. Lunar and Planetary Science XXXV: Image Processing and Earth Observations

    Science.gov (United States)

    2004-01-01

    The titles in this section include: 1) Expansion in Geographic Information Services for PIGWAD; 2) Modernization of the Integrated Software for Imagers and Spectrometers; 3) Science-based Region-of-Interest Image Compression; 4) Topographic Analysis with a Stereo Matching Tool Kit; 5) Central Avra Valley Storage and Recovery Project (CAVSARP) Site, Tucson, Arizona: Floodwater and Soil Moisture Investigations with Extraterrestrial Applications; 6) ASE Floodwater Classifier Development for EO-1 HYPERION Imagery; 7) Autonomous Sciencecraft Experiment (ASE) Operations on EO-1 in 2004; 8) Autonomous Vegetation Cover Scene Classification of EO-1 Hyperion Hyperspectral Data; 9) Long-Term Continental Areal Reduction Produced by Tectonic Processes.

  2. From local to national scale DInSAR analysis for the comprehension of Earth's surface dynamics.

    Science.gov (United States)

    De Luca, Claudio; Casu, Francesco; Manunta, Michele; Zinno, Ivana; lanari, Riccardo

    2017-04-01

    Earth Observation techniques can be very helpful for the estimation of several sources of ground deformation due to their characteristics of large spatial coverage, high resolution and cost effectiveness. In this scenario, Differential Synthetic Aperture Radar Interferometry (DInSAR) is one of the most effective methodologies for its capability to generate spatially dense deformation maps with centimeter to millimeter accuracy. DInSAR exploits the phase difference (interferogram) between SAR image pairs relevant to acquisitions gathered at different times, but with the same illumination geometry and from sufficiently close flight tracks, whose separation is typically referred to as baseline. Among several, the SBAS algorithm is one of the most used DInSAR approaches and it is aimed at generating displacement time series at a multi-scale level by exploiting a set of small baseline interferograms. SBAS, and generally DInSAR, has taken benefit from the large availability of spaceborne SAR data collected along years by several satellite systems, with particular regard to the European ERS and ENVISAT sensors, which have acquired SAR images worldwide during approximately 20 years. While the application of SBAS to ERS and ENVISAT data at local scale is widely testified, very few examples involving those archives for analysis at huge spatial scale are available in literature. This is mainly due to the required processing power (in terms of CPUs, memory and storage) and the limited availability of automatic processing procedures (unsupervised tools), which are mandatory requirements for obtaining displacement results in a time effective way. Accordingly, in this work we present a methodology for generating the Vertical and Horizontal (East-West) components of Earth's surface deformation at very large (national/continental) spatial scale. In particular, it relies on the availability of a set of SAR data collected over an Area of Interest (AoI), which could be some hundreds

  3. Process Description for the Retrieval of Earth Covered Transuranic (TRU) Waste Containers at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    DEROSA, D.C.

    2000-01-13

    This document describes process and operational options for retrieval of the contact-handled suspect transuranic waste drums currently stored below grade in earth-covered trenches at the Hanford Site. Retrieval processes and options discussed include excavation, container retrieval, venting, non-destructive assay, criticality avoidance, incidental waste handling, site preparation, equipment, and shipping.

  4. The SBAS Sentinel-1 Surveillance service for automatic and systematic generation of Earth surface displacement within the GEP platform.

    Science.gov (United States)

    Casu, Francesco; De Luca, Claudio; Lanari, Riccardo; Manunta, Michele; Zinno, Ivana

    2017-04-01

    The Geohazards Exploitation Platform (GEP) is an ESA activity of the Earth Observation (EO) ground segment to demonstrate the benefit of new technologies for large scale processing of EO data. GEP aims at providing both on-demand processing services for scientific users of the geohazards community and an integration platform for new EO data analysis processors dedicated to scientists and other expert users. In the Remote Sensing scenario, a crucial role is played by the recently launched Sentinel-1 (S1) constellation that, with its global acquisition policy, has literally flooded the scientific community with a huge amount of data acquired over large part of the Earth on a regular basis (down to 6-days with both Sentinel-1A and 1B passes). Moreover, the S1 data, as part of the European Copernicus program, are openly and freely accessible, thus fostering their use for the development of tools for Earth surface monitoring. In particular, due to their specific SAR Interferometry (InSAR) design, Sentinel-1 satellites can be exploited to build up operational services for the generation of advanced interferometric products that can be very useful within risk management and natural hazard monitoring scenarios. Accordingly, in this work we present the activities carried out for the development, integration, and deployment of the SBAS Sentinel-1 Surveillance service of CNR-IREA within the GEP platform. This service is based on a parallel implementation of the SBAS approach, referred to as P-SBAS, able to effectively run in large distributed computing infrastructures (grid and cloud) and to allow for an efficient computation of large SAR data sequences with advanced DInSAR approaches. In particular, the Surveillance service developed on GEP platform consists on the systematic and automatic processing of Sentinel-1 data on selected Areas of Interest (AoI) to generate updated surface displacement time series via the SBAS-InSAR algorithm. We built up a system that is

  5. Numerical modelling of the Earth's free surface with the level set method

    Science.gov (United States)

    Hillebrand, B.; Thieulot, C.; Geenen, T.; Van Den Berg, A. P.; Spakman, W.

    2013-12-01

    Being able to accurately model the free surface of the Earth is important for nearly all geodynamical problems. Importantly, free surface deformation is coupled to vertical motions and therefore allows for self-consistent modelling of topography build up. Such modelling allows for additional prediction from numerical models which can be compared to real Earth observations. When using an Eulerian framework, modelling the free surface is not straightforward. The so called 'sticky air' approach is then often used, in which the 'air' is modelled as a zero density fluid which has sufficient thickness (~100km) and a low viscosity compared to the underlying crust-mantle system (~5 orders of magnitude less, e.g. Crameri et al 2012). Tracers are commonly used to account for the tracking of all materials and interfaces. We here propose to use the level set method to track the interface between the crust and the air as a simulation of the free surface. The level set method represents a n-dimensional interface by a (n+1)-dimensional function chosen to be zero at the interface and it is mathematically described as a smooth (signed-distance) function. The target interface coincides with the zero level set and its location can be traced through time by solving the advection equation for the level set function and subsequently locating the zero level set every time-step. The level set method has several advantages over tracers, namely 1) the exact location of the interface is known, 2) for every point in the system the function provides its exact distance to the interface and 3) it is computationally less expensive compared to tracers (particularly in 3-D applications). We will show results of benchmarks which demonstrate the applicability of the level set function in the geodynamical modelling of surface deformation, subduction and slab detachment.

  6. Solar irradiance changes and photobiological effects at earth's surface following astrophysical ionizing radiation events.

    Science.gov (United States)

    Thomas, Brian C; Neale, Patrick J; Snyder, Brock R

    2015-03-01

    Astrophysical ionizing radiation events have been recognized as a potential threat to life on Earth, primarily through depletion of stratospheric ozone and subsequent increase in surface-level solar ultraviolet radiation. Simulations of the atmospheric effects of a variety of events (such as supernovae, gamma-ray bursts, and solar proton events) have been previously published, along with estimates of biological damage at Earth's surface. In this work, we employed the Tropospheric Ultraviolet and Visible (TUV) radiative transfer model to expand and improve calculations of surface-level irradiance and biological impacts following an ionizing radiation event. We considered changes in surface-level UVB, UVA, and photosynthetically active radiation (visible light) for clear-sky conditions and fixed aerosol parameter values. We also considered a wide range of biological effects on organisms ranging from humans to phytoplankton. We found that past work overestimated UVB irradiance but that relative estimates for increase in exposure to DNA-damaging radiation are still similar to our improved calculations. We also found that the intensity of biologically damaging radiation varies widely with organism and specific impact considered; these results have implications for biosphere-level damage following astrophysical ionizing radiation events. When considering changes in surface-level visible light irradiance, we found that, contrary to previous assumptions, a decrease in irradiance is only present for a short time in very limited geographical areas; instead we found a net increase for most of the modeled time-space region. This result has implications for proposed climate changes associated with ionizing radiation events.

  7. Inversion of Earth's changing shape to weigh sea level in static equilibrium with surface mass redistribution

    Science.gov (United States)

    Blewitt, Geoffrey; Clarke, Peter

    2003-06-01

    We develop a spectral inversion method for mass redistribution on the Earth's surface given geodetic measurements of the solid Earth's geometrical shape, using the elastic load Love numbers. First, spectral coefficients are geodetically estimated to some degree. Spatial inversion then finds the continental surface mass distribution that would force geographic variations in relative sea level such that it is self-consistent with an equipotential top surface and the deformed ocean bottom surface and such that the total (ocean plus continental mass) load has the same estimated spectral coefficients. Applying this theory, we calculate the contribution of seasonal interhemispheric (degree 1) mass transfer to variation in global mean sea level and nonsteric static ocean topography, using published GPS results for seasonal degree-1 surface loading from the global IGS network. Our inversion yields ocean-continent mass exchange with annual amplitude (2.92 ± 0.14) × 1015 kg and maximum ocean mass on 25 August ±3 days. After correction for the annual variation in global mean vertical deformation of the ocean floor (0.4 mm amplitude), we find geocentric sea level has an amplitude of 7.6 ± 0.4 mm, consistent with TOPEX-Poseidon results (minus steric effects). The seasonal variation in sea level at a point strongly depends on location ranging from 3 to 19 mm, the largest being around Antarctica in mid-August. Seasonal gradients in static topography have amplitudes of up to 10 mm over 5000 km, which may be misinterpreted as dynamic topography. Peak continental loads occur at high latitudes in late winter at the water-equivalent level of 100-200 mm.

  8. Solar Irradiance Changes And Photobiological Effects At Earth's Surface Following Astrophysical Ionizing Radiation Events

    Science.gov (United States)

    Thomas, Brian; Neale, Patrick

    2016-01-01

    Astrophysical ionizing radiation events have been recognized as a potential threat to life on Earth for decades. Although there is some direct biological damage on the surface from redistributed radiation several studies have indicated that the greatest long term threat is from ozone depletion and subsequent heightened solar ultraviolet (UV) radiation. It is known that organisms exposed to this irradiation experience harmful effects such as sunburn and even direct damage to DNA, proteins, or other cellular structures. Simulations of the atmospheric effects of a variety of events (such as supernovae, gamma-ray bursts, and solar proton events) have been previously published, along with estimates of biological damage at Earth's surface. In the present work, we employed a radiative transfer model to expand and improve calculations of surface-level irradiance and biological impacts following an ionizing radiation event. We considered changes in surface-level UVB, UVA, and photosynthetically active radiation (visible light). Using biological weighting functions we have considered a wide range of effects, including: erythema and skin cancer in humans; inhibition of photosynthesis in the diatom Phaeodactylum sp. and dinoflagellate Prorocentrum micans inhibition of carbon fixation in Antarctic phytoplankton; inhibition of growth of oat (Avena sativa L. cv. Otana) seedlings; and cataracts. We found that past work overestimated UVB irradiance, but that relative estimates for increase in exposure to DNA damaging radiation are still similar to our improved calculations. We also found that the intensity of biologically damaging radiation varies widely with organism and specific impact considered; these results have implications for biosphere-level damage following astrophysical ionizing radiation events. When considering changes in surface-level visible light irradiance, we found that, contrary to previous assumptions, a decrease in irradiance is only present for a short time in

  9. Earth Strain Measurements with a Laser Interferometer: An 800-meter Michelson interferometer monitors the earth's strain field on the surface of the ground.

    Science.gov (United States)

    Berger, J; Lovberg, R H

    1970-10-16

    The development of the laser as a source of coherent optical radiation has permitted the application of interferometric techniques to the problem of earth strain measurement. By use of this technology, an 800-meter laser strain meter has been developed which operates above the surface of the ground. The instrument has a strain least count of 10(-10), requires no calibration, and has a flat and linear response from zero frequency to 1 megahertz. The linearity and large dynamic range of the laser strain meter offer unprecedented versatility in the recording of seismic strains associated with earthquakes and nuclear blasts. The extremely wide bandwidth opens new areas of the strain spectrum to investigation. A key to the understanding of the state of stress of the earth and the association phenomona of tectonic activity and earthquakes is a knowledge of the spatial distribution of the earth strain. Measurements of secular strain and earth tides indicate that, even at these long periods, surface strain measurements are valid representations of earth strain at depth. The LSM thus provides a means of making crustal strain measurements at points selected for maximum geophysical interest and ultimately allow the mapping of strain field distributions.

  10. Surface biosignatures of exo-earths: remote detection of extraterrestrial life.

    Science.gov (United States)

    Hegde, Siddharth; Paulino-Lima, Ivan G; Kent, Ryan; Kaltenegger, Lisa; Rothschild, Lynn

    2015-03-31

    Exoplanet discovery has made remarkable progress, with the first rocky planets having been detected in the central star's liquid water habitable zone. The remote sensing techniques used to characterize such planets for potential habitability and life rely solely on our understanding of life on Earth. The vegetation red edge from terrestrial land plants is often used as a direct signature of life, but it occupies only a small niche in the environmental parameter space that binds life on present-day Earth and has been widespread for only about 460 My. To more fully exploit the diversity of the one example of life known, we measured the spectral characteristics of 137 microorganisms containing a range of pigments, including ones isolated from Earth's most extreme environments. Our database covers the visible and near-infrared to the short-wavelength infrared (0.35-2.5 µm) portions of the electromagnetic spectrum and is made freely available from biosignatures.astro.cornell.edu. Our results show how the reflectance properties are dominated by the absorption of light by pigments in the visible portion and by strong absorptions by the cellular water of hydration in the infrared (up to 2.5 µm) portion of the spectrum. Our spectral library provides a broader and more realistic guide based on Earth life for the search for surface features of extraterrestrial life. The library, when used as inputs for modeling disk-integrated spectra of exoplanets, in preparation for the next generation of space- and ground-based instruments, will increase the chances of detecting life.

  11. Exploring the Role of Adsorption and Surface State on the Hydrophobicity of Rare Earth Oxides.

    Science.gov (United States)

    Lundy, Ross; Byrne, Conor; Bogan, Justin; Nolan, Kevin; Collins, Maurice N; Dalton, Eric; Enright, Ryan

    2017-04-19

    Rare earth oxides (REOs) are attracting attention for use as cost-effective, high-performance dropwise condensers because of their favorable thermal properties and robust nature. However, to engineer a suitable surface for industrial applications, the mechanism governing wetting must be first fully elucidated. Recent studies exploring the water-wetting state of REOs have suggested that these oxides are intrinsically hydrophobic owing to the unique electronic structure of the lanthanide series. These claims have been countered with evidence that they are inherently hydrophilic and that adsorption of contaminants from the environment is responsible for the apparent hydrophobic nature of these surfaces. Here, using X-ray photoelectron spectroscopy and dynamic water contact angle measurements, we provide further evidence to show that REOs are intrinsically hydrophilic, with ceria demonstrating advancing water contact angles of ≈6° in a clean surface state and similar surface energies to two transition metal oxides (≳72 mJ/m(2)). Using two model volatile species, it is shown that an adsorption mechanism is responsible for the apparent hydrophobic property observed in REOs as well as in transition metal oxides and silica. This is correlated with the screening of the polar surface energy contribution of the underlying oxide with apparent surface energies reduced to <40 mJ/m(2) for the case of nonane adsorption. Moreover, we show that the degree of surface hydroxylation plays an important role in the observed contact angle hysteresis with the receding contact angle of ceria increasing from ∼10° to 45° following thermal annealing in an inert atmosphere. Our findings suggest that high atomic number metal oxides capable of strongly adsorbing volatile species may represent a viable paradigm toward realizing robust surface coating for industrial condensers if certain challenges can be overcome.

  12. THE DESIGN OF A HIGH PERFORMANCE EARTH IMAGERY AND RASTER DATA MANAGEMENT AND PROCESSING PLATFORM

    OpenAIRE

    Xie, Qingyun

    2016-01-01

    This paper summarizes the general requirements and specific characteristics of both geospatial raster database management system and raster data processing platform from a domain-specific perspective as well as from a computing point of view. It also discusses the need of tight integration between the database system and the processing system. These requirements resulted in Oracle Spatial GeoRaster, a global scale and high performance earth imagery and raster data management and processing pl...

  13. Changes in biologically-active ultraviolet radiation reaching the Earth's surface.

    Science.gov (United States)

    McKenzie, R L; Aucamp, P J; Bais, A F; Björn, L O; Ilyas, M

    2007-03-01

    patterns. The changes can be in both directions: ozone changes can affect climate, and climate change can affect ozone. The observational evidence suggests that stratospheric ozone (and therefore UV-B) has responded relatively quickly to changes in ozone-depleting substances, implying that climate interactions have not delayed this process. Model calculations predict that at mid-latitudes a return of ozone to pre-1980 levels is expected by the mid 21st century. However, it may take a decade or two longer in polar regions. Climate change can also affect UV radiation through changes in cloudiness and albedo, without involving ozone and since temperature changes over the 21st century are likely to be about 5 times greater than in the past century. This is likely to have significant effects on future cloud, aerosol and surface reflectivity. Consequently, unless strong mitigation measures are undertaken with respect to climate change, profound effects on the biosphere and on the solar UV radiation received at the Earth's surface can be anticipated. The future remains uncertain. Ozone is expected to increase slowly over the decades ahead, but it is not known whether ozone will return to higher levels, or lower levels, than those present prior to the onset of ozone depletion in the 1970s. There is even greater uncertainty about future UV radiation, since it will be additionally influenced by changes in aerosols and clouds.

  14. Resolving terrestrial ecosystem processes along a subgrid topographic gradient for an earth-system model

    Science.gov (United States)

    Subin, Z M; Milly, Paul C.D.; Sulman, B N; Malyshev, Sergey; Shevliakova, E

    2014-01-01

    Soil moisture is a crucial control on surface water and energy fluxes, vegetation, and soil carbon cycling. Earth-system models (ESMs) generally represent an areal-average soil-moisture state in gridcells at scales of 50–200 km and as a result are not able to capture the nonlinear effects of topographically-controlled subgrid heterogeneity in soil moisture, in particular where wetlands are present. We addressed this deficiency by building a subgrid representation of hillslope-scale topographic gradients, TiHy (Tiled-hillslope Hydrology), into the Geophysical Fluid Dynamics Laboratory (GFDL) land model (LM3). LM3-TiHy models one or more representative hillslope geometries for each gridcell by discretizing them into land model tiles hydrologically coupled along an upland-to-lowland gradient. Each tile has its own surface fluxes, vegetation, and vertically-resolved state variables for soil physics and biogeochemistry. LM3-TiHy simulates a gradient in soil moisture and water-table depth between uplands and lowlands in each gridcell. Three hillslope hydrological regimes appear in non-permafrost regions in the model: wet and poorly-drained, wet and well-drained, and dry; with large, small, and zero wetland area predicted, respectively. Compared to the untiled LM3 in stand-alone experiments, LM3-TiHy simulates similar surface energy and water fluxes in the gridcell-mean. However, in marginally wet regions around the globe, LM3-TiHy simulates shallow groundwater in lowlands, leading to higher evapotranspiration, lower surface temperature, and higher leaf area compared to uplands in the same gridcells. Moreover, more than four-fold larger soil carbon concentrations are simulated globally in lowlands as compared with uplands. We compared water-table depths to those simulated by a recent global model-observational synthesis, and we compared wetland and inundated areas diagnosed from the model to observational datasets. The comparisons demonstrate that LM3-TiHy has the

  15. The key role of global solid-Earth processes in preconditioning Greenland's glaciation since the Pliocene

    NARCIS (Netherlands)

    Steinberger, Bernhard; Spakman, Wim; Japsen, Peter; Torsvik, Trond H.

    After >500 Ma of absence, major Northern Hemisphere glaciations appeared during the Plio-Pleistocene, with Greenland leading other northern areas. Here, we propose that three major solid-Earth processes underpinned build-up of the Greenland ice-sheet. First, a mantle-plume pulse, responsible for the

  16. IsoNose - Isotopic Tools as Novel Sensors of Earth Surfaces Resources - A new Marie Curie Initial Training Network

    Science.gov (United States)

    von Blanckenburg, Friedhelm; Bouchez, Julien; Bouman, Caludia; Kamber, Balz; Gaillardet, Jérôme; Gorbushina, Anna; James, Rachael; Oelkers, Eric; Tesmer, Maja; Ashton, John

    2015-04-01

    The Marie Curie Initial Training Network »Isotopic Tools as Novel Sensors of Earth Surfaces Resources - IsoNose« is an alliance of eight international partners and five associated partners from science and industry. The project is coordinated at the Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences and will run until February 2018. In the last 15 years advances in novel mass-spectrometric methods have opened opportunities to identify "isotopic fingerprints" of virtually all metals and to make use of the complete information contained in these fingerprints. The understanding developed with these new tools will ultimately guide the exploitation of Earth surface environments. However, progress in bringing these methods to end-users depends on a multi transfer of knowledge between (1) isotope Geochemistry and Microbiology, Environmental Sciences (2), Economic Geology and (3) instrument developers and users in the development of user-friendly and new mass spectrometric methods. IsoNose will focus on three major Earth surface resources: soil, water and metals. These resources are currently being exploited to an unprecedented extent and their efficient management is essential for future sustainable development. Novel stable isotope techniques will disclose the processes generating (e.g. weathering, mineral ore formation) and destroying (e.g. erosion, pollution) these resources. Within this field the following questions will be addressed and answered: - How do novel stable isotope signatures characterize weathering processes? - How do novel stable isotope signatures trace water transport? - How to use novel stable isotope as environmental tracers? - How to use novel stable isotope for detecting and exploring metal ores? - How to improve analytical capabilities and develop robust routine applications for novel stable isotopes? Starting from the central questions mentioned above the IsoNose activities are organized in five scientific work packages: 1

  17. On the mechanical interaction between a fluid-filled fracture and the earth's surface

    Science.gov (United States)

    Pollard, D.D.; Holzhausen, G.

    1979-01-01

    The mechanical interaction between a fluid-filled fracture (e.g., hydraulic fracture joint, or igneous dike) and the earth's surface is analyzed using a two-dimensional elastic solution for a slit of arbitrary inclination buried beneath a horizontal free surface and subjected to an arbitrary pressure distribution. The solution is obtained by iteratively superimposing two fundamental sets of analytical solutions. For uniform internal pressure the slit behaves essentially as if it were in an infinite region if the depth-to-center is three times greater than the half-length. For shallower slits interaction with the free surface is pronounced: stresses and displacements near the slit differ by more than 10% from values for the deeply buried slit. The following changes are noted as the depth-to-center decreases: 1. (1) the mode I stress intensity factor increases for both ends of the slit, but more rapidly at the upper end; 2. (2) the mode II stress-intensity factor is significantly different from zero (except for vertical slits) suggesting propagation out of the original plane of the slit; 3. (3) displacements of the slit wall are asymmetric such that the slit gaps open more widely near the upper end. Similar changes are noted if fluid density creates a linear pressure gradient that is smaller than the lithostatic gradient. Under such conditions natural fractures should propagate preferentially upward toward the earth's surface requiring less pressure as they grow in length. If deformation near the surface is of interest, the model should account explicitly for the free surface. Stresses and displacements at the free surface are not approximated very well by values calculated along a line in an infinite region, even when the slit is far from the line. As depth-to-center of a shallow pressurized slit decreases, the following changes are noted: 1. (1) displacements of the free surface increase to the same order of magnitude as the displacements of the slit walls, 2. (2

  18. Process control of laser surface alloying

    NARCIS (Netherlands)

    Römer, Gerardus Richardus, Bernardus, Engelina; Meijer, J.; Olde Benneker, Jeroen

    1998-01-01

    In spite of the many advantages of laser surface treatment, such as high production rates and low induced thermal distortion, and its great potential for modifying the surface properties of a wide range of new and existing materials, industrial applications are still limited. This is not only

  19. So, how much of the Earth's surface is covered by rain gauges?

    Science.gov (United States)

    Kidd, Chris; Huffman, George; Kirschbaum, Dalia; Skofronick-Jackson, Gail; Joe, Paul; Muller, Catherine

    2014-05-01

    The measurement of global precipitation, both rainfall and snowfall, is of critical importance to a wide range of users and applications. The fundamental means of measuring precipitation is the rain gauge. Although rain gauges have many drawbacks (including not measuring snowfall well), they remain the de facto source of precipitation information across the Earth surface for hydro-meteorological purposes. While the accuracy and representative of each gauge can be assessed and monitored, a key limitation of rain and snow gauges is in their distribution across the globe. Gauges tend to be limited to the land surface where their distribution and density is very variable, while over the oceans very few gauges are available and measurements available at island locations may not truly represent those of the surrounding oceans. The total numbers of gauges across the Earth, as noted in the literature, varies greatly primarily due to temporal sampling resolutions, periods of operation, the latency of the data and the availability of the data. These numbers range from a few thousand which are available in near real time, to an estimated hundreds of thousands if one includes all available 'official' gauges (this number might swell more if all amateur gauges are included, with crowdsourcing capable of providing even more). Considering those gauges that are routinely used in the generation of global precipitation products (i.e. those available and of reasonable quality), the physical area covered by rain gauges varies by a factor of about 25. Calculations suggest that if all available rain gauges are included, they would cover between 120 and 3,000 m2. For comparison, equivalent areas range from 267 m2 for the centre circle of a football (soccer) pitch, or about 260 m2 for a tennis court to about 3,000 m2 for half a football pitch. Each gauge should represent more than just the orifice of the gauge itself, however, observations and modelling suggest that the correlation

  20. P/M Processing of Rare Earth Modified High Strength Steels.

    Science.gov (United States)

    1980-12-01

    poder of Hat 971(0.43%Ce) 164 * - ’-’ ~ ~ ~ --- (a) Magnification, 10OX (b) Magnification, 100OX Figure 6. SEM photographs of hydrogen gas atomized...earth elements was made by the RSR atomization process at Pratt & Whitney Aircraft, Government Products Division , while another RSR heat of 4340...powders with characteristics similar to RSR powders, This process was developed by Universal-Cyclops Specialty Steel Division , Cyclops Corporation, as

  1. An assessment of models which use satellite data to estimate solar irradiance at the earth's surface

    Science.gov (United States)

    Raphael, C.; Hay, J. E.

    1984-05-01

    The performances of three models which use satellite data to estimate solar irradiance at the earth's surface are assessed using measured radiation data from a midlatitude location. Assessment of the models is made possible through the accurate earth location of the satellite imagery (to within + or - 2 pixels). Evaluations of the models for a variety of conditions reveal the need for revised coefficients for the Hay and Hanson (1978) model and Tarpley (1979) model and demonstrate the superior performance of the pysically-based Gautier et al. (1980) model on an hourly basis for partly cloudy and overcast conditions. However, compared to the clear-sky case all three models give poor results under partly cloudy and overcast conditions. An increase in the averaging period leads to marked decreases in the rms errors observed for the three models under all conditions, with the greatest improvement occuring for the Hay and Hanson model. Suggestions for improvements include a more accurate and explicit treatment of cloud absorption in all three models and the inclusion of the effects of aerosols under clear skies and the accurate and objective specification of a cloud threshold separating clear from partly cloudy and partly cloudy from overcast conditions in the Gautier et al. and Tarpley models.

  2. Using the level set method in geodynamical modeling of multi-material flows and Earth's free surface

    Directory of Open Access Journals (Sweden)

    B. Hillebrand

    2014-11-01

    Full Text Available The level set method allows for tracking material surfaces in 2-D and 3-D flow modeling and is well suited for applications of multi-material flow modeling. The level set method utilizes smooth level set functions to define material interfaces, which makes the method stable and free of oscillations that are typically observed in case step-like functions parameterize interfaces. By design the level set function is a signed distance function and gives for each point in the domain the exact distance to the interface as well as on which side it is located. In this paper we present four benchmarks which show the validity, accuracy and simplicity of using the level set method for multi-material flow modeling. The benchmarks are simplified setups of dynamical geophysical processes such as the Rayleigh–Taylor instability, post-glacial rebound, subduction and slab detachment. We also demonstrate the benefit of using the level set method for modeling a free surface with the sticky air approach. Our results show that the level set method allows for accurate material flow modeling and that the combination with the sticky air approach works well in mimicking Earth's free surface. Since the level set method tracks material interfaces instead of materials themselves, it has the advantage that the location of these interfaces is accurately known and that it represents a viable alternative to the more commonly used tracer method.

  3. Study on rare-earth elements distribution in surface waters of Primorsky region

    Science.gov (United States)

    Vakh, E. A.; Vakh, A. S.; Petukhov, V. I.; Pavlova, G. Ya; Tarasenko, I. A.; Zubtsova, A. S.

    2017-10-01

    Data obtained by the authors show that the background level of the rare-earth element (REE) content in the surface waters of southern Russian Far East is irregular and varies from 0.1 to 1.3 μg/l. The highest concentration of REE (0.48–1.3 μg/l) is characteristic for the rivers of Eastern Sikhote-Alin and Central Sikhote-Alin, catchment areas which are situated within the Sikhote-Alin volcanic belt. The lowest REE concentration was noted in the waters of Western Sikhote-Alin (0.09 μg/l). The profile of REE distribution in fresh waters of different areas of the region is uniform and is characterized with the deficit of Ce and enrichment of medium group REE.

  4. Processing and Protection of Rare Earth Permanent Magnet Particulate for Bonded Magnet Applications

    Energy Technology Data Exchange (ETDEWEB)

    Sokolowski, Peter Kelly [Iowa State Univ., Ames, IA (United States)

    2007-01-01

    Rapid solidification of novel mixed rare earth-iron-boron, MRE2Fe14B (MRE = Nd, Y, Dy; currently), magnet alloys via high pressure gas atomization (HPGA) have produced similar properties and structures as closely related alloys produced by melt spinning (MS) at low wheel speeds. Recent additions of titanium carbide and zirconium to the permanent magnet (PM) alloy design in HPGA powder (using He atomization gas) have made it possible to achieve highly refined microstructures with magnetic properties approaching melt spun particulate at cooling rates of 105-106K/s. By producing HPGA powders with the desirable qualities of melt spun ribbon, the need for crushing ribbon was eliminated in bonded magnet fabrication. The spherical geometry of HPGA powders is more ideal for processing of bonded permanent magnets since higher loading fractions can be obtained during compression and injection molding. This increased volume loading of spherical PM powder can be predicted to yield a higher maximum energy product (BH)max for bonded magnets in high performance applications. Passivation of RE-containing powder is warranted for the large-scale manufacturing of bonded magnets in applications with increased temperature and exposure to humidity. Irreversible magnetic losses due to oxidation and corrosion of particulates is a known drawback of RE-Fe-B based alloys during further processing, e.g. injection molding, as well as during use as a bonded magnet. To counteract these effects, a modified gas atomization chamber allowed for a novel approach to in situ passivation of solidified particle surfaces through injection of a reactive gas, nitrogen trifluoride (NF3). The ability to control surface chemistry during atomization processing of fine spherical RE-Fe-B powders produced advantages over current processing methodologies. In particular, the capability to coat particles while 'in flight' may eliminate the

  5. Technology and human purpose: the problem of solids transport on the Earth's surface

    Directory of Open Access Journals (Sweden)

    P. K. Haff

    2012-11-01

    Full Text Available Displacement of mass of limited deformability ("solids" on the Earth's surface is opposed by friction and (the analog of form resistance – impediments relaxed by rotational motion, self-powering of mass units, and transport infrastructure. These features of solids transport first evolved in the biosphere prior to the emergence of technology, allowing slope-independent, diffusion-like motion of discrete objects as massive as several tons, as illustrated by animal foraging and movement along game trails. However, high-energy-consumption technology powered by fossil fuels required a mechanism that could support fast advective transport of solids, i.e., long-distance, high-volume, high-speed, unidirectional, slope-independent transport across the land surface of materials like coal, containerized fluids, minerals, and economic goods. Pre-technology nature was able to sustain regional- and global-scale advection only in the limited form of piggybacking on geophysical flows of water (river sediment and air (dust. The appearance of a mechanism for sustained advection of solids independent of fluid flows and gravity appeared only upon the emergence of human purpose. Purpose enables solids advection by, in effect, simulating a continuous potential gradient, otherwise lacking, between discrete and widely separated fossil-fuel energy sources and sinks. Invoking purpose as a mechanism in solids advection is an example of the need to import anthropic principles and concepts into the language and methodology of modern Earth system dynamics. As part of the emergence of a generalized solids advection mechanism, several additional transport requirements necessary to the function of modern large-scale technological systems were also satisfied. These include spatially accurate delivery of advected payload, targetability to essentially arbitrarily located destinations (such as cities, and independence of structure of advected payload from transport mechanism. The

  6. Hyperresolution Global Land Surface Modeling: Meeting a Grand Challenge for Monitoring Earth's Terrestrial Water

    Science.gov (United States)

    Wood, Eric F.; Roundy, Joshua K.; Troy, Tara J.; van Beek, L. P. H.; Bierkens, Marc F. P.; 4 Blyth, Eleanor; de Roo, Ad; Doell. Petra; Ek, Mike; Famiglietti, James; hide

    2011-01-01

    Monitoring Earth's terrestrial water conditions is critically important to many hydrological applications such as global food production; assessing water resources sustainability; and flood, drought, and climate change prediction. These needs have motivated the development of pilot monitoring and prediction systems for terrestrial hydrologic and vegetative states, but to date only at the rather coarse spatial resolutions (approx.10-100 km) over continental to global domains. Adequately addressing critical water cycle science questions and applications requires systems that are implemented globally at much higher resolutions, on the order of 1 km, resolutions referred to as hyperresolution in the context of global land surface models. This opinion paper sets forth the needs and benefits for a system that would monitor and predict the Earth's terrestrial water, energy, and biogeochemical cycles. We discuss six major challenges in developing a system: improved representation of surface-subsurface interactions due to fine-scale topography and vegetation; improved representation of land-atmospheric interactions and resulting spatial information on soil moisture and evapotranspiration; inclusion of water quality as part of the biogeochemical cycle; representation of human impacts from water management; utilizing massively parallel computer systems and recent computational advances in solving hyperresolution models that will have up to 10(exp 9) unknowns; and developing the required in situ and remote sensing global data sets. We deem the development of a global hyperresolution model for monitoring the terrestrial water, energy, and biogeochemical cycles a grand challenge to the community, and we call upon the international hydrologic community and the hydrological science support infrastructure to endorse the effort.

  7. Sources and distribution of yttrium and rare earth elements in surface sediments from Tagus estuary, Portugal.

    Science.gov (United States)

    Brito, Pedro; Prego, Ricardo; Mil-Homens, Mário; Caçador, Isabel; Caetano, Miguel

    2018-04-15

    The distribution and sources of yttrium and rare-earth elements (YREE) in surface sediments were studied on 78 samples collected in the Tagus estuary (SW Portugal, SW Europe). Yttrium and total REE contents ranged from 2.4 to 32mg·kg-1 and 18 to 210mg·kg-1, respectively, and exhibited significant correlations with sediment grain-size, Al, Fe, Mg and Mn, suggesting a preferential association to fine-grained material (e.g. aluminosilicates but also Al hydroxides and Fe oxyhydroxides). The PAAS (Post-Archean Australian Shale) normalized patterns display three distinct YREE fractionation pattern groups along the Tagus estuary: a first group, characterized by medium to coarse-grained material, a depleted and almost flat PAAS-normalized pattern, with a positive anomaly of Eu, representing one of the lithogenic components; a second group, characterized mainly by fine-grained sediment, with higher shale-normalized ratios and an enrichment of LREE relative to HREE, associated with waste water treatment plant (WWTP) outfalls, located in the northern margin; and, a third group, of fine-grained material, marked by a significant enrichment of Y, a depletion of Ce and an enrichment of HREE over LREE, located near an inactive chemical-industrial complex (e.g. pyrite roast plant, chemical and phosphorous fertilizer industries), in the southern margin. The data allow the quantification of the YREE contents and its spatial distribution in the surface sediments of the Tagus estuary, identifying the main potential sources and confirming the use of rare earth elements as tracers of anthropogenic activities in highly hydrodynamic estuaries. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Leaching of Light Rare Earth Elements from Sichuan Bastnaesite: A Facile Process to Leach Trivalent Rare Earth Elements Selectively from Tetravalent Cerium

    Science.gov (United States)

    Shen, Yueyue; Jiang, Ying; Qiu, Xianying; Zhao, Shilin

    2017-10-01

    The effects of the nitric acid concentration, leaching time, leaching temperature, and solid-to-liquid ratio on leaching efficiency were examined. From those results, a facile process for the selective leaching of trivalent rare earth elements (RE(III)) from tetravalent cerium (Ce(IV)) was proposed. The roasted bastnaesite was used to leach 34.87% of RE(III) and 2.15% of Ce(IV) at 60°C for 0.5 h with an acid concentration of 0.5 mol/L. This selective leaching process can be described by the shrinking-core model that follows the kinetic model 1 - 2/3 α - (1 - α)2/3. Subsequently, the leached slag was hydrothermally treated and followed by thorough leaching with 4.0-mol/L nitric acid. Furthermore, the specific surface area of the final leached slag is 57.7 m2/g, which is approximately 650 times higher than that of raw ore. Finally, selective leaching of RE(III) (>90%) was achieved without using an organic solvent for extraction, whereas lower value Ce(IV)was presented in the leached slag (>92%).

  9. Erosion and lateral surface processes 2432

    Science.gov (United States)

    : Erosion can cause serious agricultural and environmental hazards. It can generate severe damage to the landscape, lead to significant loss of agricultural land and consequently to reduction in agricultural productivity, induce surface water pollution due to the transport of sediments and suspende...

  10. Influence of albedo parameterization on surface mass balance in the perspective of Greenland ice sheet modelling in EC-Earth

    OpenAIRE

    Helsen, Michiel; Van De Wal, Roderik,; Reerink, Thomas; Bintanja, Richard; Sloth Madsen, Marianne; Yang, Shuting; Li, Qiang; Zhang, Qiong

    2016-01-01

    The albedo of the surface of ice sheets changes as a function of time, due to the effects of deposition of new snow, ageing of dry snow, melting and runoff. Currently, the calculation of the albedo of ice sheets is highly parameterized within the Earth System Model EC-Earth, by taking a constant value for areas with thick perennial snow cover. This is one of the reasons that the surface mass balance (SMB) of the Greenland ice sheet (GrIS) is poorly resolved in the model. To improve this, eigh...

  11. Probing Earth's conductivity structure beneath oceans by scalar geomagnetic data: autonomous surface vehicle solution

    Science.gov (United States)

    Kuvshinov, Alexey; Matzka, Jürgen; Poedjono, Benny; Samrock, Friedemann; Olsen, Nils; Pai, Sudhir

    2016-11-01

    The electric conductivity distribution of the Earth's crust and upper mantle provides a key to unraveling its structure. Information can be obtained from vector data time series of the natural variations of the magnetic and electric field in a directional stable reference frame. Applying this method, known as magnetotellurics, to oceanic regions is challenging since only vector instruments placed at the sea bottom can provide such data. Here, we discuss a concept of marine induction surveying which is based on sea-surface scalar magnetic field measurements from a modern position-keeping platform. The concept exploits scalar magnetic responses that relate variations of the scalar magnetic field at the survey sites with variations of the horizontal magnetic field at a reference site. A 3-D model study offshore Oahu Island (Hawaii) demonstrates that these responses are sensitive to the conductivity structure beneath the ocean. We conclude that the sensitivity, depending on the bathymetry gradient, is typically largest near the coast offshore. We show that such sea-surface marine induction surveys can be performed with the Wave Glider, an easy-to-deploy, autonomous, energy-harvesting floating platform with position-keeping capability.[Figure not available: see fulltext.

  12. A STUDY ON INTERACTION OF Cd(II AND DIATOMACEOUS EARTH IN ADSORPTION PROCESS

    Directory of Open Access Journals (Sweden)

    Nuryono Nuryono

    2010-06-01

    Full Text Available In this research, interaction occurring in adsorption process between Cd(II and active site of diatomaceous earth has been studied. The study was carried out by evaluating Cd(II adsorption on diatomaceous earth at various pHs, either for the earths without treatment, those after being heated or those treated with sulfuric acid and hydrogen chloride. Adsorption was performed by mixing diatomaceous earth, without and with treatments, and Cd(II solution for one hour at various pHs (2 - 7, and un-adsorbed metallic ion was analyzed by atomic absorption spectroscopy (AAS. The treatments of diatomaceous earth included heating at temperatures of 300, 500, and 900oC for four hours, treatments with acids (3, 8, and 12 M of H2SO4, and 3, 15, and 18 M of HCl solutions for two hours at 150-200oC. Results showed that the increasing of pH from 2.0 to 3.0 and from 6.0 to 7.0 inclined adsorption of Cd(II from 13.2 to 23.3 mg/g and from 24.0 to 26.4 mg/g, respectively. At a pH range of 3.0 - 6.0 the adsorption slightly increase from 23.3 to 24.0 mg/g. Heating of diatomaceous earth higher than 500oC caused the adsorption capability to be independence of the pH of solution. On the other hand, treatments with acids (H2SO4 and HCl caused adsorption capability increased significantly with the increase in pH from 3.0 to 6.0. Adsorption evaluation at the pH range investigated showed that adsorption of Cd(II on diatomaceous earth may be through interaction between Cd2+ and functional groups of T-OH (T = Si/Al.   Keywords: adsorption, adsorbent, cadmium, diatomaceous earth

  13. Advanced oxidation process sanitization of eggshell surfaces

    National Research Council Canada - National Science Library

    Gottselig, Steven M; Dunn-Horrocks, Sadie L; Woodring, Kristy S; Coufal, Craig D; Duong, Tri

    2016-01-01

    ... and poultry products. The hydrogen peroxide (H2O2) and ultraviolet (UV) light advanced oxidation process is a potentially important alternative to traditional sanitizers and disinfectants for egg sanitation...

  14. Effect of surface deposited rare earth oxide gel characteristics on cyclic oxidation behavior of Fe20-Cr alloys

    Directory of Open Access Journals (Sweden)

    Stela Maria Cristina Fernandes

    2006-06-01

    Full Text Available Rare earths have been used to increase high temperature oxidation resistance of many chromium dioxide and alumina forming alloys. These rare earths can be added as elements (or as oxide dispersions to the alloys or applied as an oxide coating to the alloy surface. The sol-gel technique is considered to be very efficient to apply fine oxide particle coatings. Oxide gel coatings of various rare earths such as lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, dysprosium, yttrium, erbium and ytterbium have been applied to an iron-chromium alloy to determine their influence on the cyclic oxidation behavior (RT-900 °C of the alloy. The morphology and coverage of the rare earth oxide gels varied with the type of rare earth. The cyclic oxidation resistance of the alloy increased with increase in time at temperature required to reach a specific chromium dioxide layer thickness and this in turn was influenced by the rare earth ion radius and characteristics of the rare earth oxide coating such as morphology, stability, coverage, resistance to thermal stresses and consequently adhesion.

  15. Early Evaluation of the VIIRS Calibration, Cloud Mask and Surface Reflectance Earth Data Records

    Science.gov (United States)

    Vermote, Eric; Justice, Chris; Csiszar, Ivan

    2014-01-01

    Surface reflectance is one of the key products fromVIIRS and as withMODIS, is used in developing several higherorder land products. The VIIRS Surface Reflectance (SR) Intermediate Product (IP) is based on the heritageMODIS Collection 5 product (Vermote, El Saleous, & Justice, 2002). The quality and character of surface reflectance depend on the accuracy of the VIIRS Cloud Mask (VCM), the aerosol algorithms and the adequate calibration of the sensor. The focus of this paper is the early evaluation of the VIIRS SR product in the context of the maturity of the operational processing system, the Interface Data Processing System (IDPS). After a brief introduction, the paper presents the calibration performance and the role of the surface reflectance in calibration monitoring. The analysis of the performance of the cloud mask with a focus on vegetation monitoring (no snow conditions) shows typical problems over bright surfaces and high elevation sites. Also discussed is the performance of the aerosol input used in the atmospheric correction and in particular the artifacts generated by the use of the Navy Aerosol Analysis and Prediction System. Early quantitative results of the performance of the SR product over the AERONET sites showthatwith the fewadjustments recommended, the accuracy iswithin the threshold specifications. The analysis of the adequacy of the SR product (Land PEATE adjusted version) in applications of societal benefits is then presented. We conclude with a set of recommendations to ensure consistency and continuity of the JPSS mission with the MODIS Land Climate Data Record.

  16. The Significance of Land-Atmosphere Processes in the Earth System

    Science.gov (United States)

    Suni, T.; Kulmala, M. T.; Guenther, A. B.

    2012-12-01

    The land-atmosphere interface is where humans primarily operate. Humans modify the land surface in many ways that influence the fluxes of energy and trace gases between land and atmosphere. Their emissions change the chemical composition of the atmosphere and anthropogenic aerosols change the radiative balance of the globe directly by scattering sunlight back to space and indirectly by changing the properties of clouds. Feedback loops among all these processes, land, the atmosphere, and biogeochemical cycles of nutrients and trace gases extend the human influence even further. Over the last decade, the importance of land-atmosphere processes and feedbacks in the Earth System has been shown on many levels and with multiple approaches, and a number of publications have shown the crucial role of the terrestrial ecosystems as regulators of climate [1-6]. Modellers have clearly shown the effect of missing land cover changes and other feedback processes and regional characteristics in current climate models and recommended actions to improve them [7-11]. Unprecedented insights of the long-term net impacts of aerosols on clouds and precipitation have also been provided [12-14]. Land-cover change has been emphasized with model intercomparison projects that showed that realistic land-use representation was essential in land surface modelling [11, 15]. Crucially important tools in this research have been the networks of long-term flux stations and large-scale land-atmosphere observation platforms that are also beginning to combine remote sensing techniques with ground observations [16-20]. Human influence has always been an important part of land-atmosphere science but in order to respond to the new challenges of global sustainability, closer ties with social science and economics groups will be necessary to produce realistic estimates of land use and anthropogenic emissions by analysing future population increase, migration patterns, food production allocation, land

  17. Surface Electromyography Signal Processing and Classification Techniques

    Science.gov (United States)

    Chowdhury, Rubana H.; Reaz, Mamun B. I.; Ali, Mohd Alauddin Bin Mohd; Bakar, Ashrif A. A.; Chellappan, Kalaivani; Chang, Tae. G.

    2013-01-01

    Electromyography (EMG) signals are becoming increasingly important in many applications, including clinical/biomedical, prosthesis or rehabilitation devices, human machine interactions, and more. However, noisy EMG signals are the major hurdles to be overcome in order to achieve improved performance in the above applications. Detection, processing and classification analysis in electromyography (EMG) is very desirable because it allows a more standardized and precise evaluation of the neurophysiological, rehabitational and assistive technological findings. This paper reviews two prominent areas; first: the pre-processing method for eliminating possible artifacts via appropriate preparation at the time of recording EMG signals, and second: a brief explanation of the different methods for processing and classifying EMG signals. This study then compares the numerous methods of analyzing EMG signals, in terms of their performance. The crux of this paper is to review the most recent developments and research studies related to the issues mentioned above. PMID:24048337

  18. Surface processing methods for point sets using finite elements

    NARCIS (Netherlands)

    Clarenz, Ulrich; Rumpf, Martin; Telea, Alexandru

    2004-01-01

    We present a framework for processing point-based surfaces via partial differential equations (PDEs). Our framework efficiently and effectively brings well-known PDE-based processing techniques to the field of point-based surfaces. At the core of our method is a finite element discretization of PDEs

  19. Using Paraffin PCM, Cryogel and TEC to Maintain Comet Surface Sample Cold from Earth Approach Through Retrieval

    Science.gov (United States)

    Choi, Michael K.

    2017-01-01

    An innovative thermal design concept to maintain comet surface samples cold (for example, 263 degrees Kelvin, 243 degrees Kelvin or 223 degrees Kelvin) from Earth approach through retrieval is presented. It uses paraffin phase change material (PCM), Cryogel insulation and thermoelectric cooler (TEC), which are commercially available.

  20. A Novel Heat Treatment Process for Surface Hardening of Steel: Metal Melt Surface Hardening

    Science.gov (United States)

    Fu, Yong-sheng; Zhang, Wei; Xu, Xiaowei; Li, Jiehua; Li, Jun; Xia, Mingxu; Li, Jianguo

    2017-09-01

    A novel heat treatment process for surface hardening of steel has been demonstrated and named as "metal melt surface hardening (MMSH)." A surface layer with a thickness of about 400 μm and a hardness of about 700 HV has been achieved by ejecting AISI 304 stainless steel melt at a temperature of about 1783 K (1510 °C) onto the 40Cr steel surface. This proposed MMSH provides a very promising application for surface hardening of steel.

  1. TanDEM-X the Earth surface observation project from space level - basis and mission status

    Directory of Open Access Journals (Sweden)

    Jerzy Wiśniowski

    2015-03-01

    Full Text Available TanDEM-X is DLR (Deutsches Zentrum für Luft- und Raumfahrt the Earth surface observation project using high-resolution SAR interferometry. It opens a new era in space borne radar remote sensing. The system is based on two satellites: TerraSAR-X (TSX and TanDEM-X (TDX flying on the very close, strictly controlled orbits. This paper gives an overview of the radar technology and overview of the TanDEM-X mission concept which is based on several innovative technologies. The primary objective of the mission is to deliver a global digital elevation model (DEM with an unprecedented accuracy, which is equal to or surpass the HRTI-3 specifications (12 m posting, relative height accuracy ±2 m for slope < 20% and ±4 m for slope > 20% [8]. Beyond that, TanDEM-X provides a highly reconfigurable platform for the demonstration of new radar imaging techniques and applications.[b]Keywords[/b]: remote sensing, Bistatic SAR, digital elevation model (DEM, Helix formation, SAR interferomery, HRTI-3, synchronization

  2. Geochemical characteristics of rare earth elements in the surface sediments from the Spratly Islands of China.

    Science.gov (United States)

    Li, Jingxi; Sun, Chengjun; Zheng, Li; Yin, Xiaofei; Chen, Junhui; Jiang, Fenghua

    2017-01-30

    The geochemistry of rare earth elements (REE) in surface sediment from Cuarteron reef (N1), Johnson reef (N2), Hugh reef (N3), Gaven reef (N4), Fiery cross reef (N5), and Subi reef (N6) were firstly studied. The total REE abundance (∑REE) varied from 2.244μg·g-1 to 21.661μg·g-1, with an average of 4.667μg·g-1. The LREE/HREE was from 2.747 to 9.869, with an average of 3.687, which indicated that the light REE was evidently enriched. Fractionation was observed between LREE and HREE. Gd with a negative anomaly was also detected in all of the stations. The negative anomalies of δEu from 0.11 to 0.25, with an average of 0.22, and the positive anomalies of δCe from 1.38 to 3.86, with an average of 1.63. The REE individual correlation values with Ca, Mn, Mg, Sr were rCa=-0.05, rMn=0.26, rMg=-0.14, and rSr=0.08. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Effect of surface related organic vibrational modes in luminescent upconversion dynamics of rare earth ions doped nanoparticles.

    Science.gov (United States)

    Wang, Yu; Smolarek, Szymon; Kong, Xianggui; Buma, Wybren Jan; Brouwer, Albert Manfred; Zhang, Hong

    2010-11-01

    Physical and chemical properties of nanoparticles are known to be subject to the surface factors. For their biological/biomedical applications, typically, surface of the nanoparticles has to be modified which inevitably affects their performance. In this work we have studied the interaction between the surface related organic vibrational modes and the luminescent centers--rare earth ions--in one of the most efficient luminescence upconversion nanosystems--NaYF4. Specifically, the surface quenching centers, the surface related luminescent centers, as well as the role of shell properties, are investigated spectroscopically. Our results demonstrate that the surface related high-frequency vibrational modes can be critical to the spectral properties of the nanosystems once the surface is not well separated from the discrete luminescent centers.

  4. In-situ buildup of cosmogenic isotopes at the earth`s surface: measurement of erosion rates and exposure times

    Energy Technology Data Exchange (ETDEWEB)

    Fifield, L.K.; Allan, G.L.; Stone, J.O.H.; Evans, J.M.; Cresswell, R.G.; Ophel, T.R. [Australian National Univ., Canberra, ACT (Australia)

    1993-12-31

    Cosmic rays produce a number of nuclides in rocks that can be used to determine the geomorphic history of surfaces. The most useful are the radioactive isotopes {sup 10}Be (t{sub 1/2} = 1.5Ma), {sup 26}Al (0.7Ma) and {sup 36}Cl (0.3Ma). Within the top 2m of the surface, these are produced principally by fast neutrons. At greater depths, production is dominated by the capture of negative muons. Measurements of a single nuclide produced in situ can be used to determine total exposure times or erosion rates. The use of multiple nuclides with different half-lives makes it possible to determine more complex histories, such as exposures interrupted by periods of burial. At the ANU, all three of the isotopes above are being used to study a variety of problems in geomorphology and paleoclimatology, although to date, most of the work has concentrated on {sup 36}Cl. The accumulation of cosmogenic {sup 36}Cl in calcite (CaCO{sub 3}) provides a means of measuring erosion rates on limestone surfaces. Sensitivity is achieved over a wide range of erosion rates due to the high production rate of {sup 36}Cl in calcite (typically greater than 30 atoms/g/yr) and a detection limit of ca. 5000 atoms/g attainable with the ANU AMS system. The method is simplified by the predominance of Ca reactions (principally spallation) over other sources of {sup 36}Cl in calcite, and the ease of sample preparation. This presentation discuss the results of measurements of {sup 36}Cl in calcite from limestone samples from Australia and Papua New Guinea. Erosion rates derived from these measurements range from 3 microns per year (Australia) to over 200 microns per year in the New Guinea highlands. 3 refs.

  5. Thermodynamic Investigation of the Reduction-Distillation Process for Rare Earth Metals Production

    Science.gov (United States)

    Judge, W. D.; Azimi, G.

    2017-10-01

    Owing to their high vapor pressure, the four rare earth metals samarium, europium, thulium, and ytterbium are produced by reduction-distillation whereby their oxides are reduced with metallic lanthanum in vacuo, and the produced metal is subsequently vaporized off. Here, we performed a thorough thermodynamic investigation to establish a fundamental understanding of the reduction-distillation process. Thermodynamic functions including vapor pressures, Gibbs free energies, and enthalpies of reaction were calculated and compared with available experimental data. Furthermore, the kinetics of the process was explored and theoretical evaporation rates were calculated from thermodynamic data. The thermodynamic model developed in this work can help optimize processing conditions to maximize the yield and improve the overall process.

  6. Final Report Collaborative Project. Improving the Representation of Coastal and Estuarine Processes in Earth System Models

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Frank [National Center for Atmospheric Research, Boulder, CO (United States); Dennis, John [National Center for Atmospheric Research, Boulder, CO (United States); MacCready, Parker [Univ. of Washington, Seattle, WA (United States); Whitney, Michael [Univ. of Connecticut

    2015-11-20

    This project aimed to improve long term global climate simulations by resolving and enhancing the representation of the processes involved in the cycling of freshwater through estuaries and coastal regions. This was a collaborative multi-institution project consisting of physical oceanographers, climate model developers, and computational scientists. It specifically targeted the DOE objectives of advancing simulation and predictive capability of climate models through improvements in resolution and physical process representation. The main computational objectives were: 1. To develop computationally efficient, but physically based, parameterizations of estuary and continental shelf mixing processes for use in an Earth System Model (CESM). 2. To develop a two-way nested regional modeling framework in order to dynamically downscale the climate response of particular coastal ocean regions and to upscale the impact of the regional coastal processes to the global climate in an Earth System Model (CESM). 3. To develop computational infrastructure to enhance the efficiency of data transfer between specific sources and destinations, i.e., a point-to-point communication capability, (used in objective 1) within POP, the ocean component of CESM.

  7. Particle engineering in pharmaceutical solids processing: surface energy considerations.

    Science.gov (United States)

    Williams, Daryl R

    2015-01-01

    During the past 10 years particle engineering in the pharmaceutical industry has become a topic of increasing importance. Engineers and pharmacists need to understand and control a range of key unit manufacturing operations such as milling, granulation, crystallisation, powder mixing and dry powder inhaled drugs which can be very challenging. It has now become very clear that in many of these particle processing operations, the surface energy of the starting, intermediate or final products is a key factor in understanding the processing operation and or the final product performance. This review will consider the surface energy and surface energy heterogeneity of crystalline solids, methods for the measurement of surface energy, effects of milling on powder surface energy, adhesion and cohesion on powder mixtures, crystal habits and surface energy, surface energy and powder granulation processes, performance of DPI systems and finally crystallisation conditions and surface energy. This review will conclude that the importance of surface energy as a significant factor in understanding the performance of many particulate pharmaceutical products and processes has now been clearly established. It is still nevertheless, work in progress both in terms of development of methods and establishing the limits for when surface energy is the key variable of relevance.

  8. How accurately do we know the temperature of the surface of the earth?

    Science.gov (United States)

    Lovejoy, S.

    2017-12-01

    The earth's near surface air temperature is important in a variety of applications including for quantifying global warming. We analyze 6 monthly series of atmospheric temperatures from 1880 to 2012, each produced with different methodologies. We first estimate the relative error by systematically determining how close the different series are to each other, the error at a given time scale is quantified by the root mean square fluctuations in the pairwise differences between the series as well as between the individual series and the average of all the available series. By examining the differences systematically from months to over a century, we find that the standard short range correlation assumption is untenable, that the differences in the series have long range statistical dependencies and that the error is roughly constant between 1 month and one century—over most of the scale range, varying between ±0.03 and ±0.05 K. The second part estimates the absolute measurement errors. First we make a stochastic model of both the true earth temperature and then of the measurement errors. The former involves a scaling (fractional Gaussian noise) natural variability term as well as a linear (anthropogenic) trend. The measurement error model involves three terms: a classical short range error, a term due to missing data and a scale reduction term due to insufficient space-time averaging. We find that at 1 month, the classical error is ≈±0.01 K, it decreases rapidly at longer times and it is dominated by the others. Up to 10-20 years, the missing data error gives the dominate contribution to the error: 15 ± 10% of the temperature variance; at scales >10 years, the scale reduction factor dominates, it increases the amplitude of the temperature anomalies by 11 ± 8% (these uncertainties quantify the series to series variations). Finally, both the model itself as well as the statistical sampling and analysis techniques are verified on stochastic simulations that show

  9. In-process characterization of surface topography changes during nitration

    Science.gov (United States)

    Ciossek, Andreas; Lehmann, Peter; Patzelt, Stefan; Goch, Gert

    2000-09-01

    The nitration process influences the mechanical and chemical properties of steel and changes the near-surface characteristics. The nitrided surfaces are less sensitive to corrosive fluids and show a better stability against abrasion. Unfortunately, during treatment pores emerge at the surface. In general this is not desired, since the pores reduce the wear stability. The change of the near-surface characteristics also leads to a remodeling of the surface topography. For example, ground, smooth surfaces show an increased but isotropic roughness after nitration. During the recent years, various speckle techniques for an in-process characterization of surface topography have been improved significantly. One of these promising techniques is the method of trichromatic speckle autocorrelation. Its measuring principle is based on trichromatic light scattering and enables to determine an integral parameter of the surface roughness by the evaluation of the speckle elongation. Especially in the case of nitration, where the specimen is located in a stove filled with ammonia at a temperature of 580 degrees Celsius, this technique offers an in-processing monitoring of surface topography changes from outside the stove. In this paper, the in-process characterization of surface topography by speckle autocorrelation will be introduced. In this context an algorithm has been developed, which allows to estimate the position of the optical axis within the speckle pattern and therefore to determine the surface roughness as well as the local inclination of isotropic surfaces. An important goal of the current research is to realize a reliable process control based on the speckle autocorrelation, that is necessary to produce nitrided surfaces without pores in the compound layer and with good abrasive and corrosive resistance.

  10. Technology Readiness Level Assessment Process as Applied to NASA Earth Science Missions

    Science.gov (United States)

    Leete, Stephen J.; Romero, Raul A.; Dempsey, James A.; Carey, John P.; Cline, Helmut P.; Lively, Carey F.

    2015-01-01

    Technology assessments of fourteen science instruments were conducted within NASA using the NASA Technology Readiness Level (TRL) Metric. The instruments were part of three NASA Earth Science Decadal Survey missions in pre-formulation. The Earth Systematic Missions Program (ESMP) Systems Engineering Working Group (SEWG), composed of members of three NASA Centers, provided a newly modified electronic workbook to be completed, with instructions. Each instrument development team performed an internal assessment of its technology status, prepared an overview of its instrument, and completed the workbook with the results of its assessment. A team from the ESMP SEWG met with each instrument team and provided feedback. The instrument teams then reported through the Program Scientist for their respective missions to NASA's Earth Science Division (ESD) on technology readiness, taking the SEWG input into account. The instruments were found to have a range of TRL from 4 to 7. Lessons Learned are presented; however, due to the competition-sensitive nature of the assessments, the results for specific missions are not presented. The assessments were generally successful, and produced useful results for the agency. The SEWG team identified a number of potential improvements to the process. Particular focus was on ensuring traceability to guiding NASA documents, including the NASA Systems Engineering Handbook. The TRL Workbook has been substantially modified, and the revised workbook is described.

  11. Surface reactivity, cytotoxic, and morphological transforming effects of diatomaceous Earth products in Syrian hamster embryo cells.

    Science.gov (United States)

    Elias, Zoé; Poirot, Odile; Fenoglio, Ivana; Ghiazza, Mara; Danière, Marie-Céleste; Terzetti, Francine; Darne, Christian; Coulais, Catherine; Matekovits, Ildiko; Fubini, Bice

    2006-06-01

    In order to evaluate the effect of thermal treatments on the surface reactivity and carcinogenic potential of diatomaceous earth (DE) products, the physicochemical features of some specimens--derived by heating the same original material--were compared with their cytotoxic and transforming potency. The samples were an untreated DE (amorphous) progressively heated in the laboratory at 900 degrees C (DE 900) and 1200 degrees C (DE 1200) and a commercial product manufactured from the same DE (Chd) from which the finer fraction (reactive oxygen species, and for their cytotoxic and transforming potencies in Syrian hamster embryo (SHE) cells. X-ray diffractometry showed that DE 900, like DE, was still amorphous, whereas DE 1200 as well as the commercial product (Chd) were partially crystallized into cristobalite. The ability of the dust to release hydroxyl (*OH) radicals in the presence of hydrogen peroxide, as revealed by the spin-trapping technique, was as follows: Chd-F, DE 1200 > Chd > DE 900 > DE, suggesting that on heating, the surface acquires a higher potential for free radical release. Most of the silica samples generated COO* radicals from the formate ion, following homolytic rupture of the carbon-hydrogen bond, in the presence of ascorbic acid. A concentration-dependent decrease in cell proliferation and colony-forming efficiency was observed in SHE cultures treated with Chd-F, Chd, and DE. Heating abolished DE cytotoxicity but conferred a transforming ability to thermal treated particles. DE was the only sample that did not induce morphological transformation of cells. According to their transformation capacity, the samples were classified as follows: Chd-F > Chd, DE 1200 > DE 900 > DE. Taken together, the reported results suggest that (1) the transforming potential of a biogenic amorphous silica is related to the thermal treatment that transforms the original structure in cristobalite and generates surface active sites; (2) the reactivity of samples in

  12. User guide: Earth resources observation and science (EROS) center science processing architecture (ESPA) on demand interface

    Science.gov (United States)

    Jenkerson, Calli

    2013-01-01

    Landsat data have been produced, archived, and distributed by the U.S. Geological Survey (USGS) since 1972. Scientists and users rely on these data for historical study of land surface change, but shoulder the burden of post-production processing to create applications-ready data sets. In compliance with guidelines established through the Global Climate Observing System, USGS has embarked on production of higher-level Landsat data products to support land surface change study. Terrestrial variables such as surface reflectance and land surface temperature will be offered as Climate Data Records (CDR). Derivations of spectral indices from surface reflectance are also produced, to further ease user application in land remote sensing science. Higher level products, such as leaf area index, burned area extent, snow covered area, and surface water extent representing Essential Climate Variables (ECV) will be available soon.

  13. Framework for Processing Citizens Science Data for Applications to NASA Earth Science Missions

    Science.gov (United States)

    Teng, William; Albayrak, Arif

    2017-01-01

    Citizen science (or crowdsourcing) has drawn much high-level recent and ongoing interest and support. It is poised to be applied, beyond the by-now fairly familiar use of, e.g., Twitter for natural hazards monitoring, to science research, such as augmenting the validation of NASA earth science mission data. This interest and support is seen in the 2014 National Plan for Civil Earth Observations, the 2015 White House forum on citizen science and crowdsourcing, the ongoing Senate Bill 2013 (Crowdsourcing and Citizen Science Act of 2015), the recent (August 2016) Open Geospatial Consortium (OGC) call for public participation in its newly-established Citizen Science Domain Working Group, and NASA's initiation of a new Citizen Science for Earth Systems Program (along with its first citizen science-focused solicitation for proposals). Over the past several years, we have been exploring the feasibility of extracting from the Twitter data stream useful information for application to NASA precipitation research, with both "passive" and "active" participation by the twitterers. The Twitter database, which recently passed its tenth anniversary, is potentially a rich source of real-time and historical global information for science applications. The time-varying set of "precipitation" tweets can be thought of as an organic network of rain gauges, potentially providing a widespread view of precipitation occurrence. The validation of satellite precipitation estimates is challenging, because many regions lack data or access to data, especially outside of the U.S. and in remote and developing areas. Mining the Twitter stream could augment these validation programs and, potentially, help tune existing algorithms. Our ongoing work, though exploratory, has resulted in key components for processing and managing tweets, including the capabilities to filter the Twitter stream in real time, to extract location information, to filter for exact phrases, and to plot tweet distributions. The

  14. Testing variational estimation of process parameters and initial conditions of an earth system model

    Directory of Open Access Journals (Sweden)

    Simon Blessing

    2014-03-01

    Full Text Available We present a variational assimilation system around a coarse resolution Earth System Model (ESM and apply it for estimating initial conditions and parameters of the model. The system is based on derivative information that is efficiently provided by the ESM's adjoint, which has been generated through automatic differentiation of the model's source code. In our variational approach, the length of the feasible assimilation window is limited by the size of the domain in control space over which the approximation by the derivative is valid. This validity domain is reduced by non-smooth process representations. We show that in this respect the ocean component is less critical than the atmospheric component. We demonstrate how the feasible assimilation window can be extended to several weeks by modifying the implementation of specific process representations and by switching off processes such as precipitation.

  15. Superhydrophobic coatings for aluminium surfaces synthesized by chemical etching process

    Directory of Open Access Journals (Sweden)

    Priya Varshney

    2016-10-01

    Full Text Available In this paper, the superhydrophobic coatings on aluminium surfaces were prepared by two-step (chemical etching followed by coating and one-step (chemical etching and coating in a single step processes using potassium hydroxide and lauric acid. Besides, surface immersion time in solutions was varied in both processes. Wettability and surface morphologies of treated aluminium surfaces were characterized using contact angle measurement technique and scanning electron microscopy, respectively. Microstructures are formed on the treated aluminium surfaces which lead to increase in contact angle of the surface (>150°. Also on increasing immersion time, contact angle further increases due to increase in size and depth of microstructures. Additionally, these superhydrophobic coatings show excellent self-cleaning and corrosion-resistant behavior. Water jet impact, floatation on water surface, and low temperature condensation tests assert the excellent water-repellent nature of coatings. Further, coatings are to be found mechanically, thermally, and ultraviolet stable. Along with, these coatings are found to be excellent regeneration ability as verified experimentally. Although aforesaid both processes generate durable and regenerable superhydrophobic aluminium surfaces with excellent self-cleaning, corrosion-resistant, and water-repellent characteristics, but one-step process is proved more efficient and less time consuming than two-step process and promises to produce superhydrophobic coatings for industrial applications.

  16. Use of advanced earth observation tools for the analyses of recent surface changes in Kalahari pans and Namibian coastal lagoons

    Science.gov (United States)

    Behling, Robert; Milewski, Robert; Chabrillat, Sabine; Völkel, Jörg

    2016-04-01

    The remote sensing analyses in the BMBF-SPACES collaborative project Geoarchives - Signals of Climate and Landscape Change preserved in Southern African Geoarchives - focuses on the use of recent and upcoming Earth Observation Tools for the study of climate and land use changes and its impact on the ecosystem. It aims at demonstrating the potential of recently available advanced optical remote sensing imagery with its extended spectral coverage and temporal resolution for the identification and mapping of sediment features associated with paleo-environmental archives as well as their recent dynamic. In this study we focus on the analyses of two ecosystems of major interest, the Kalahari salt pans as well as the lagoons at Namibia's west coast, that present high dynamic caused by combined hydrological and surface processes linked to climatic events. Multitemporal remote sensing techniques allow us to derive the recent surface dynamic of the salt pans and also provide opportunities to get a detailed understanding of the spatiotemporal development of the coastal lagoons. Furthermore spaceborne hyperspectral analysis can give insight to the current surface mineralogy of the salt pans on a physical basis and provide the intra pan distribution of evaporites. The soils and sediments of the Kalahari salt pans such as the Omongwa pan are a potentially significant storage of global carbon and also function as an important terrestrial climate archive. Thus far the surface distribution of evaporites have been only assessed mono-temporally and on a coarse regional scale, but the dynamic of the salt pans, especially the formation of evaporites, is still uncertain and poorly understood. For the salt pan analyses a change detection is applied using the Iterative-reweighted Multivariate Alteration Detection (IR-MAD) method to identify and investigate surface changes based on a Landsat time-series covering the period 1984-2015. Furthermore the current spatial distribution of

  17. COMPARISON OF SPACE IMAGES OF A SURFACE OF EARTH TO A STANDARD OF A DIGITAL DISTRICT MAP

    Directory of Open Access Journals (Sweden)

    A. A. Zalatoi

    2016-01-01

    Full Text Available In article problems of comparison of space pictures with a standard of a digital district map for tasks of updating of cartographical information and monitoring of the territories are considered. The purpose is development of a technique of automated detection of cumulative changes in space pictures concerning a standard of a digital district map in optionally the set analysis window. Researches and development of a technique were made by mathematical simulation of the task in the environment of MATLAB. The last results of researches in the form of the developed technique of detection of cumulative changes of object composition in the orthotransformed and geobound space pictures of the Earth’s surface concerning a standard of a vectorial digital district map are given in article. The main results of comparison of space pictures to a digital district map received in case of tests of the developed technique are shown. Application of this technique allows to automate process already now and to reduce time of the subject analysis of the space information obtained by Earth remote-sensing instruments for topographical mapping.

  18. Estimation of errors caused by spherical approximation of earth shape in coordinates determination process of radio emission source using bearings

    OpenAIRE

    Kochergin, Anatoliy; Chebotov, Olexandr; Chebotov, Volodymyr

    2012-01-01

    Estimation of errors in the process of coordinates’ determination of radio source with spherical approximation is conducted. It is demonstrated that for increasing of coordinates’ determination accuracy on spreading paths ellepsoidity of earth shape should be taken into consideration.

  19. SURFACE CAST IRON STRENGTHENING USING COMBINED LASER AND ULTRASONIC PROCESSING

    Directory of Open Access Journals (Sweden)

    O. G. Devojno

    2013-01-01

    Full Text Available The paper provides an analysis of ultrasonic surface plastic deformation and subsequent laser thermal strengthening of gray cast iron parts in the regime of hardening from a solid state with the purpose to obtain strengthened surface layers of bigger depth and less roughness of the processed surface. Program complex ANSYS 11.0 has been used for calculation of temperature fields induced by laser exposure.  The appropriate regime of laser processing without surface fusion has been selected on the basis of the applied complex. The possibility of displacement in the bottom boundary of α–γ-transformation temperature  for СЧ20 with 900 °С up to 800 °С is confirmed due to preliminary ultrasonic surface plastic deformation of the surface that allows to expand technological opportunities of laser quenching  of gray  cast iron from a solid state. 

  20. THE DESIGN OF A HIGH PERFORMANCE EARTH IMAGERY AND RASTER DATA MANAGEMENT AND PROCESSING PLATFORM

    Directory of Open Access Journals (Sweden)

    Q. Xie

    2016-06-01

    Full Text Available This paper summarizes the general requirements and specific characteristics of both geospatial raster database management system and raster data processing platform from a domain-specific perspective as well as from a computing point of view. It also discusses the need of tight integration between the database system and the processing system. These requirements resulted in Oracle Spatial GeoRaster, a global scale and high performance earth imagery and raster data management and processing platform. The rationale, design, implementation, and benefits of Oracle Spatial GeoRaster are described. Basically, as a database management system, GeoRaster defines an integrated raster data model, supports image compression, data manipulation, general and spatial indices, content and context based queries and updates, versioning, concurrency, security, replication, standby, backup and recovery, multitenancy, and ETL. It provides high scalability using computer and storage clustering. As a raster data processing platform, GeoRaster provides basic operations, image processing, raster analytics, and data distribution featuring high performance computing (HPC. Specifically, HPC features include locality computing, concurrent processing, parallel processing, and in-memory computing. In addition, the APIs and the plug-in architecture are discussed.

  1. A two-dimensional atmospheric chemistry modeling investigation of Earth's Phanerozoic O3 and near-surface ultraviolet radiation history

    Science.gov (United States)

    Harfoot, Michael B. J.; Beerling, David J.; Lomax, Barry H.; Pyle, John A.

    2007-04-01

    We use the Cambridge two-dimensional (2-D) chemistry-radiation transport model to investigate the implications for column O3 and near-surface ultraviolet radiation (UV), of variations in atmospheric O2 content over the Phanerozoic (last 540 Myr). Model results confirm some earlier 1-D model investigations showing that global annual mean O3 column increases monotonically with atmospheric O2. Sensitivity studies indicate that changes in temperature and N2O exert a minor influence on O3 relative to O2. We reconstructed Earth's O3 history by interpolating the modeled relationship between O3 and O2 onto two Phanerozoic O2 histories. Our results indicate that the largest variation in Phanerozoic column O3 occurred between 400 and 200 Myr ago, corresponding to a rise in atmospheric O2 to ˜1.5 times the present atmospheric level (PAL) and subsequent fall to ˜0.5 PAL. The O3 response to this O2 decline shows latitudinal differences, thinning most at high latitudes (30-40 Dobson units (1 DU = 0.001 atm cm) at 66°N) and least at low latitudes (5-10 DU at 9°N) where a "self-healing" effect is evident. This O3 depletion coincides with significant increases in the near-surface biologically active UV radiation at high latitudes, +28% as weighted by the Thimijan spectral weighting function. O3 and UV changes were exacerbated when we incorporated a direct feedback of the terrestrial biosphere on atmospheric chemistry, through enhanced N2O production as the climate switched from an icehouse to a greenhouse mode. On the basis of a summary of field and laboratory experimental evidence, we suggest that these UV radiation increases may have exerted subtle rather than catastrophic effects on ecosystem processes.

  2. ENVI Services Engine: Earth and Planetary Image Processing for the Cloud

    Science.gov (United States)

    O'Connor, A. S.; Lausten, K.; Heightley, K.; Harris, T.

    2012-12-01

    The geospatial imagery analysis and exploitation community has a growing need for online analytic capabilities. Work previously done on desktop workstations must migrate to a web-accessible environment to mitigate growing data volumetrics, bandwidth usage, and end user requirements. Web based applications (or 'apps') are intended to apply analytic methods, procedures, and routines to image datasets stored within centralized server repositories. Exelis Visual information Solutions (VIS) developed an enterprise-enabled processing engine that provides remote users access to the power of ENVI image analysis and IDL applications from a web or mobile client interface. The working name for this capability is the ENVI and IDL Services Engine (ESE). This engine now enables the remote user to gain access to the same compiled ENVI and IDL functions and procedures that remote sensing scientists have utilized for decades at the desktop level. ESE operates in a RESTful state, listening for http calls to arrive that initiate a data processing operation once those messages are registered. ESE is middleware agnostic, meaning users can implement this capability using their current enterprise architecture such as ArcGIS Server or GeoServer. Flexibility and openness in middleware components is achieved through the use of OGC standards for message and data transfer. ESE represents bringing long term earth science monitoring analysis capabilities to the cloud, harnessing existing ENVI and IDL tools and deploying them to the enterprise, and improving access to earth and planetary science data.

  3. Pioneering mass measurements in the rare-earth region for the astrophysical r-process

    Science.gov (United States)

    Kelly, James M.; Vilen, Markus; Brodeur, Maxime; Kankainen, Anu; Igisol Team

    2017-09-01

    The astrophysical r-process generates around half of the elements heavier than iron, yet precisely where or how this occurs remains a topic of intense inquiry. Understanding the formation of one of its hallmarks, the rare-earth abundance peak, could shed light on the astrophysical sites because this feature is very sensitive to underlying nuclear properties, particularly to nuclear binding energies which have so far been largely derived from theoretical mass models. We have performed precise atomic mass measurements of 12 neutron-rich rare-earth isotopes using the JYFLTRAP double Penning trap mass spectrometer. The atomic masses of 158Nd, 160Pm, 162Sm, and 164-166Gd have been experimentally determined for the first time, and the precisions for 156Nd, 158Pm, 162,163Eu, 163Gd, and 164Tb have been significantly improved. The 163Gd measurement also indicates the presence of a previously suspected isomeric state. Trends in two-neutron separation energies are compared to theoretical mass model predictions, and the effects of these new mass measurements on r-process abundance calculations will be examined.

  4. An integrated approach to friction surfacing process optimisation

    OpenAIRE

    Voutchkov, I.I.; Jaworski, B.; Vitanov, V.I.; Bedford, G.M.

    2001-01-01

    This paper discusses the procedures for data collection, management and optimisation of the friction surfacing process. Experimental set-up and characteristics of measuring equipment are found to match the requirements for accurate and unbiased data signals. The main friction surfacing parameters are identified and the first stage of the optimisation process is achieved by visually assessing the coatings and introducing the substrate speed vs. force map. The optimum values from this first sta...

  5. Laboratory study of asteroid surface processes due to electrostatic dust mobilization

    Science.gov (United States)

    Wang, Xu; Schwan, Joseph; Hood, Noah; Hsu, Hsiang-Wen; Horanyi, Mihaly

    2017-10-01

    Our recent laboratory work has shown a strong evidence that dust particles on the surface of airless bodies such as asteroids are expected to be electrostatically lofted or mobilized due to exposure to ultraviolet (UV) radiation or energetic electrons. These electrostatic processes may have a significant contribution in shaping the surfaces of asteroids or other airless bodies. One critical question is how efficient these processes can be in changing the surface physical characteristics of asteroids. Here we report a series of laboratory experiments that record dust activities as a function of the fluxes of UV photons or energetic electrons over a long exposure time. Our preliminary results show that the surface morphology is changed significantly due to dust mobilization and becomes smoothened over time, on millimeter-to-centimeter scale under Earth gravity. Our results also indicate that the dynamics of dust mobilization may be complicated by temporal charging effect as dust moves. It was found that dust mobilization largely depends on the size and type of dust particles. These new experimental data will help us better characterize the dynamics of electrostatic dust mobilization and can be ultimately extrapolated to the space situations in order to estimate the timescale of the electrostatic processes in comparison to other surface processes, e.g., thermal fragmentation.

  6. Exchange processes from the deep interior to the surface of icy moons

    Science.gov (United States)

    Grasset, O.

    present dynamics of icy surfaces: erosion, tectonics and cryovolcanism. This second topic is devoted to the description of the surface features. A synthesis of what has been seen in the jovian system and a presentation of what is now discovered in the saturnian system might be useful. 3) Internal processes: dynamics of icy mantles. Many works have been done specifically for icy moons (rheology of icy mantles, heating modes, effect of ice composition, internal activity of small moons, internal oceans,. . . ). Icy mantles present so many different convective processes, depending on parameters such as the ice composition, the heating mode, . . . , that a full review of the recent progress on the subject is required. 4) Physics and chemistry of ices: experimental constraints on hydrates, clathrates and organics. Nothing can be done without experimental data. Thermodynamical constraints, phase diagrams, but also mechanical properties of icy materials are required for constraining all models. Many progress have been made these last five years, especially for clathrate structures so important in the case of Titan. A review of these progresses is required. 5) Earth analogs: a tool for understanding surface/ internal features. Tectonic and volcanic features on icy moons are sometimes confronted to Earth structures. This procedure is very interesting. While materials are different (on Earth the melt is lighter than the rock, but on icy moons it is the contrary), tectonic and volcanic features can be very similar. Our good understanding of the Earth can be very useful for describing the processes responsible of tectonic/volcanic features on the moons. Discussing around the five themes described above may provide some constraints on open questions such as the characteristics of liquid layers within icy moons, the cryovolcanism on Titan, the resurfacing of Europa, the composition of Titan's surface, and the activity on Enceladus. 2

  7. Mobility of rare earth element in hydrothermal process and weathering product: a review

    Science.gov (United States)

    Lintjewas, L.; Setiawan, I.

    2018-02-01

    The Rare Earth Element (REE), consists of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Lu, Ho, Er, Tm, Yb, are important elements to be used as raw materials of advanced technology such as semiconductors, magnets, and lasers. The research of REE in Indonesia has not been done. Several researches were conducted on granitic rocks and weathering product such as Bangka, Sibolga, West Kalimantan, West Sulawesi and Papua. REE can be formed by hydrothermal processes such as Bayan Obo, South China. The REE study on active hydrothermal system (geothermal) in this case also has the potential to produce mineral deposits. The purpose of this review paper is to know the mobility of REE on hydrothermal process and weathering products. Mobility of REE in the hydrothermal process can change the distribution patterns and REE content such as Ce, Eu, La, Lu, Nd, Sm, and Y. Another process besides the hydrothermal is weathering process. REE mobility is influenced by weathering products, where the REE will experience residual and secondary enrichment processes in heavier minerals.

  8. Approximating the r-Process on Earth with Thermonuclear Explosions. Lessons Learned and Unanswered Questions

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Stephen Allan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-01-28

    During the astrophysical r-process, multiple neutron captures occur so rapidly on target nuclei that their daughter nuclei generally do not have time to undergo radioactive decay before another neutron is captured. The r-process can be approximately simulated on Earth in certain types of thermonuclear explosions through an analogous process of rapid neutron captures known as the "prompt capture" process. Between 1952 and 1969, 23 nuclear tests were fielded by the US which were involved (at least partially) with the "prompt capture" process. Of these tests, 15 were at least partially successful. Some of these tests were conducted under the Plowshare Peaceful Nuclear Explosion Program as scientific research experiments. It is now known that the USSR conducted similar nuclear tests during 1966 to 1979. The elements einsteinium and fermium were first discovered by this process. The most successful tests achieved 19 successive neutron captures on the initial target nuclei. A review of the US program, target nuclei used, heavy element yields, scientific achievements of the program, and how some of the results have been used by the astrophysical community is given. Finally, some unanswered questions concerning very neutron-rich nuclei that could potentially have been answered with additional nuclear experiments is presented.

  9. Surface Modification of Blood Contacting Biomedical Implants by Plasma Processes

    Science.gov (United States)

    Huang, N.; Yang, P.; Leng, Y. X.; Chen, J. Y.; Wang, J.; Sun, H.; Wan, G. J.; Chu, P. K.; Leng, Y.

    2003-06-01

    Surface modification is becoming an increasingly popular method to Improve the surface properties of biomedical materials and implants. Among the techniques plasma processes have been attracting attention because of their high effect and low cost. In this paper some application of plasma processes such as plasma modification, plasma polymerization, films synthesis, and plasma based ion implantation etc to modify blood contacting biomaterials and implants are presented. The authors work on the surface modification of artificial heart valves, stents and catheter etc. are provided. The further development of this discipline is discussed.

  10. Simulation Studies on the Computation of the Gravity Vector in Space from Surface Data Considering the Topography of the Earth,

    Science.gov (United States)

    1981-06-01

    collocation , see Tscherning and Rapp (1974), Tscherning (1976), and SiInkel (1979). Advanced aspects on collocation are discussed in Moritz (1980...and Moritz and Sinkel (1978). The collocation estimation of a quantity s from gravity anomalies Ag , can be done using the equation below ( Moritz , 1972...Green’s third identity, the Discrete Dirac approach, and the Least-Squares Collocation approach. Under a spherical approximation, the surface of the earth

  11. Increased insolation threshold for runaway greenhouse processes on Earth-like planets.

    Science.gov (United States)

    Leconte, Jérémy; Forget, Francois; Charnay, Benjamin; Wordsworth, Robin; Pottier, Alizée

    2013-12-12

    The increase in solar luminosity over geological timescales should warm the Earth's climate, increasing water evaporation, which will in turn enhance the atmospheric greenhouse effect. Above a certain critical insolation, this destabilizing greenhouse feedback can 'run away' until the oceans have completely evaporated. Through increases in stratospheric humidity, warming may also cause evaporative loss of the oceans to space before the runaway greenhouse state occurs. The critical insolation thresholds for these processes, however, remain uncertain because they have so far been evaluated using one-dimensional models that cannot account for the dynamical and cloud feedback effects that are key stabilizing features of the Earth's climate. Here we use a three-dimensional global climate model to show that the insolation threshold for the runaway greenhouse state to occur is about 375 W m(-2), which is significantly higher than previously thought. Our model is specifically developed to quantify the climate response of Earth-like planets to increased insolation in hot and extremely moist atmospheres. In contrast with previous studies, we find that clouds have a destabilizing feedback effect on the long-term warming. However, subsident, unsaturated regions created by the Hadley circulation have a stabilizing effect that is strong enough to shift the runaway greenhouse limit to higher values of insolation than are inferred from one-dimensional models. Furthermore, because of wavelength-dependent radiative effects, the stratosphere remains sufficiently cold and dry to hamper the escape of atmospheric water, even at large fluxes. This has strong implications for the possibility of liquid water existing on Venus early in its history, and extends the size of the habitable zone around other stars.

  12. Web Services Implementations at Land Process and Goddard Earth Sciences Distributed Active Archive Centers

    Science.gov (United States)

    Cole, M.; Bambacus, M.; Lynnes, C.; Sauer, B.; Falke, S.; Yang, W.

    2007-12-01

    NASA's vast array of scientific data within its Distributed Active Archive Centers (DAACs) is especially valuable to both traditional research scientists as well as the emerging market of Earth Science Information Partners. For example, the air quality science and management communities are increasingly using satellite derived observations in their analyses and decision making. The Air Quality Cluster in the Federation of Earth Science Information Partners (ESIP) uses web infrastructures of interoperability, or Service Oriented Architecture (SOA), to extend data exploration, use, and analysis and provides a user environment for DAAC products. In an effort to continually offer these NASA data to the broadest research community audience, and reusing emerging technologies, both NASA's Goddard Earth Science (GES) and Land Process (LP) DAACs have engaged in a web services pilot project. Through these projects both GES and LP have exposed data through the Open Geospatial Consortiums (OGC) Web Services standards. Reusing several different existing applications and implementation techniques, GES and LP successfully exposed a variety data, through distributed systems to be ingested into multiple end-user systems. The results of this project will enable researchers world wide to access some of NASA's GES & LP DAAC data through OGC protocols. This functionality encourages inter-disciplinary research while increasing data use through advanced technologies. This paper will concentrate on the implementation and use of OGC Web Services, specifically Web Map and Web Coverage Services (WMS, WCS) at GES and LP DAACs, and the value of these services within scientific applications, including integration with the DataFed air quality web infrastructure and in the development of data analysis web applications.

  13. Deterministic processes for manufacturing conformal (freeform) optical surfaces

    Science.gov (United States)

    Ruckman, Jeffrey L.; Fess, Edward M.; Pollicove, Harvey M.

    2001-09-01

    This paper describes the computer-controlled machines and deterministic processes developed by the Center for Optics Manufacturing (COM) at the University of Rochester to produce conformal windows and domes that have non-traditional optical surface geometry and unusual shapes. COM's DMG (deterministic microgrinding) technology produces aspheric and conformal (freeform) surfaces in minutes, versus the weeks that are required to produce the surfaces conventionally. The demonstrated techniques and equipment provide a predictable and repeatable optical production process for just about any IR, visible, or UV material. The DMG process, in concert with newly developed CNC machining equipment, typically yields 1.0 wave peak-to-valley form accuracy, 150 Angstroms rms surface finish, and subsurface damage levels low enough that some of the infrared materials do not require additional polishing.

  14. Solid Earth: Introduction

    Science.gov (United States)

    Rummel, R.

    1991-10-01

    The principles of the solid Earth program are introduced. When considering the study of solid Earth from space, satellites are used as beacons, inertial references, free fall probes and carrying platforms. The phenomenon measured by these satellites and the processes which can be studied as a result of these measurements are tabulated. The NASA solid Earth program focusses on research into surface kinematics, Earth rotation, land, ice, and ocean monitoring. The ESA solid Earth program identifies as its priority the Aristoteles mission for determining the gravity and magnetic field globally, with high spatial resolution and high accuracy. The Aristoteles mission characteristics and goals are listed. The benefits of the improved gravity information that will be provided by this mission are highlighted. This information will help in the following research: geodesy, orbit mechanics, geodynamics, oceanography, climate sea level, and the atmosphere.

  15. High speed ultrafast laser surface processing (Conference Presentation)

    Science.gov (United States)

    Mincuzzi, Girolamo; Kling, Rainer; Lopez, John; Hoenninger, Clemens; Audouard, Eric; Mottay, Eric P.

    2017-03-01

    Surface functionalization is a rapidly growing application for industrial ultrafast lasers. There is an increasing interest for high throughput surface processing, especially for texturing and engraving large manufacturing tools for different industrial fields such as injection molding, embossing and printing. Hydrophobic and hydrophilic surfaces, colored or deep black metal surfaces can now be industrially produced. The engraving speed is continuously improving following improvements in beam scanning technology and high average power industrial ultrafast lasers. Several tenths of MHz for the laser repetition rate and several hundreds of meter per second for the beam speed are available. More than 100 m/s scanning speed is then possible for laser surface structuring. But these surfaces are quite hard to produce since it is necessary to have a good compromise between high removal rate and high surface quality (low roughness, burr-free, narrow heat affected zone). In this work, we apply a simple engineering model based on the two temperature description of ultra-fast ablation to estimate key processing parameters. In particular, the pulse-to-pulse overlap which depends on the scanning velocity, the spot size, and the laser repetition rate all have to be adjusted to optimize the depth and roughness, otherwise heat accumulation and heat affected zone may appear. Optimal sequences of time and spatial superposition of pulses are determined and applied with a polygonal scanner. Ablation depth and processing speed obtained are compared with experimental results.

  16. Putting Technology to Work in Science - How to Select Unmanned Aerial Vehicles (UAV) and their Instrumentation for Atmospheric and Earth Surface Observations

    Science.gov (United States)

    Teller, Amit; Lange, Manfred; Ioannou, Stelios; Keleshis, Christos

    2010-05-01

    The Autonomous Flying Platforms for Atmospheric and Earth Surface Observations project (APAESO) of the Energy, Environment and Water Research Center (EEWRC) at the Cyprus Institute is aimed at the dual purpose of carrying out atmospheric and earth-surface observations in the Mediterranean. The APAESO platforms will offer the unique potential to determine physical, chemical and radiative atmospheric properties, aerosol and dust concentrations, atmospheric dynamics, surface morphology, vegetation and land use patterns as well as ocean surface properties (biology, waves, currents) and to carry out archaeological site reconnaissance and contaminant detection at high spatial resolution. The first phase of APAESO was dedicated to the preliminary design and the selection of an Unmanned Aerial Vehicle (UAV) as the backbone of the APAESO infrastructure. Selection of a UAV suitable for the many research objectives as outlined above is challenging because the UAV technology is new and rapidly evolving. This notwithstanding, a very large number of systems, mostly utilized for defense purposes, are currently available. The major challenge in the selection process lies in considering the trade-off between different platform characteristics (e.g. payload weight, endurance, max. altitude for operation and price) and in optimizing the potential performance of the UAV. Based on the required characteristics for the UAV platform, a survey of possible UAVs and suitable sensors was prepared based on various data sources. We used an elimination process in order to consider only a few models for the final selection process out of about 1000 commercially available UAV models that were initially investigated. The presentation will discuss the main scientific objectives that determine the specification of the UAV platform, major considerations in selecting best available technology for our needs and will briefly describe the next phases of the project.

  17. Pedogenetic processes in anthrosols with pretic horizon (Amazonian Dark Earth in Central Amazon, Brazil.

    Directory of Open Access Journals (Sweden)

    Rodrigo S Macedo

    Full Text Available Anthrosols known as Amazonian Dark Earth (ADE have borne witness to the intensification of sedentary patterns and the demographic increase in Central Amazon. As a result, a recurring pattern has been observed of mounds with ADE arising from domestic activities and the disposal of waste. The objective of this research was to demonstrate the relationship of these anthropic activities with pedogenetic formation processes of ADE in the municipality of Iranduba, Brazil. Disturbed and undisturbed soil samples were taken from two areas of ADE (pretic horizon and from a non-anthropic pedon. Physical, chemical, micromorphological and SEM-EDS analyses were performed. The coarse material of the pretic horizons consisted predominantly of quartz, iron nodules, ceramics and charcoal fragments, and the fine material is organo-mineral. There was a direct relationship between the color of pretic horizons and the number of charcoal fragments. The thickness of the ADE results from the redistribution of charcoal at depth through bioturbation, transforming subsurface horizons into anthropic horizons. ADE presents granular microaggregates of geochemical and zoogenetic origin. Degradation of iron nodules is intensified in pretic horizons, promoting a reverse pedogenic process contributing to the xanthization process. Surprisingly the anthropic activities also favor clay dispersion and argilluviation; clay coatings on the ceramic fragments and in the pores demonstrate that this is a current process. Processes identified as contributing to ADE genesis included: i addition of organic residues and ceramic artifacts (cumulization with the use of fire; ii mechanical action of humans, roots and macrofauna (bioturbation; iii melanization of deeper horizons as a result of bioturbation; iv argilluviation and degradation of iron nodules. This study offers new support to archaeological research in respect to ADE formation processes in Central Amazon and confirmed the hypothesis

  18. Preface to highly siderophile element constraints on Earth and planetary processes

    Science.gov (United States)

    Riches, Amy J. V.

    2017-11-01

    The geochemical properties of the highly siderophile elements (HSEs; Os, Ir, Ru, Rh, Pt, Pd, Re and Au) - being strongly iron-loving, but also chalcophile (i.e., having an affinity for sulphide), and generally occurring at ultra trace levels in silicate rocks, their weathered products, and oceanic waters - mean that this suite of elements and their isotopic compositions are useful in tracing a wide variety of processes. Thus, the HSEs are useful probes with which to tackle major research questions pertinent to past and present day change at a variety of scales and in a range of Earth and other-worldly environments by constraining reservoir compositions, chemical drivers, and the timing of key events and/or transformation rates.

  19. Understanding Global Change: Tools for exploring Earth processes and biotic change through time

    Science.gov (United States)

    Bean, J. R.; White, L. D.; Berbeco, M.

    2014-12-01

    Teaching global change is one of the great pedagogical challenges of our day because real understanding entails integrating a variety of concepts from different scientific subject areas, including chemistry, physics, and biology, with a variety of causes and impacts in the past, present, and future. With the adoption of the Next Generation Science Standards, which emphasize climate change and other human impacts on natural systems, there has never been a better time to provide instructional support to educators on these topics. In response to this clear need, the University of California Museum of Paleontology, in collaboration with the National Center for Science Education, developed a new web resource for teachers and students titled "Understanding Global Change" (UGC) that introduces the drivers and impacts of global change. This website clarifies the connections among deep time, modern Earth system processes, and anthropogenic influences, and provides K-16 instructors with a wide range of easy-to-use tools, strategies, and lesson plans for communicating these important concepts regarding global change and the basic Earth systems processes. In summer 2014, the UGC website was field-tested during a workshop with 25 K-12 teachers and science educators. Feedback from participants helped the UGC team develop and identify pedagogically sound lesson plans and instructional tools on global change. These resources are accessible through UGC's searchable database, are aligned with NGSS and Common Core, and are categorized by grade level, subject, and level of inquiry-based instruction (confirmation, structured, guided, open). Providing a range of content and tools at levels appropriate for teachers is essential because our initial needs assessment found that educators often feel that they lack the content knowledge and expertise to address complex, but relevant global change issues, such as ocean acidification and deforestation. Ongoing needs assessments and surveys of

  20. Representing Global Reactive Potential Energy Surfaces Using Gaussian Processes.

    Science.gov (United States)

    Kolb, Brian; Marshall, Paul; Zhao, Bin; Jiang, Bin; Guo, Hua

    2017-04-06

    Representation of multidimensional global potential energy surfaces suitable for spectral and dynamical calculations from high-level ab initio calculations remains a challenge. Here, we present a detailed study on constructing potential energy surfaces using a machine learning method, namely, Gaussian process regression. Tests for the 3A″ state of SH2, which facilitates the SH + H ↔ S(3P) + H2 abstraction reaction and the SH + H' ↔ SH' + H exchange reaction, suggest that the Gaussian process is capable of providing a reasonable potential energy surface with a small number (∼1 × 102) of ab initio points, but it needs substantially more points (∼1 × 103) to converge reaction probabilities. The implications of these observations for construction of potential energy surfaces are discussed.

  1. A reactive distillation process for the treatment of LiCl-KCl eutectic waste salt containing rare earth chlorides

    Energy Technology Data Exchange (ETDEWEB)

    Eun, H.C., E-mail: ehc2004@kaeri.re.kr; Choi, J.H.; Kim, N.Y.; Lee, T.K.; Han, S.Y.; Lee, K.R.; Park, H.S.; Ahn, D.H.

    2016-11-15

    The pyrochemical process, which recovers useful resources (U/TRU metals) from used nuclear fuel using an electrochemical method, generates LiCl-KCl eutectic waste salt containing radioactive rare earth chlorides (RECl{sub 3}). It is necessary to develop a simple process for the treatment of LiCl-KCl eutectic waste salt in a hot-cell facility. For this reason, a reactive distillation process using a chemical agent was achieved as a method to separate rare earths from the LiCl-KCl waste salt. Before conducting the reactive distillation, thermodynamic equilibrium behaviors of the reactions between rare earth (Nd, La, Ce, Pr) chlorides and the chemical agent (K{sub 2}CO{sub 3}) were predicted using software. The addition of the chemical agent was determined to separate the rare earth chlorides into an oxide form using these equilibrium results. In the reactive distillation test, the rare earth chlorides in LiCl-KCl eutectic salt were decontaminated at a decontamination factor (DF) of more than 5000, and were mainly converted into oxide (Nd{sub 2}O{sub 3}, CeO{sub 2}, La{sub 2}O{sub 3}, Pr{sub 2}O{sub 3}) or oxychloride (LaOCl, PrOCl) forms. The LiCl-KCl was purified into a form with a very low concentration (<1 ppm) for the rare earth chlorides.

  2. Contemporary movements in the earth surface in the geodynamic region of Uzbekistan

    Energy Technology Data Exchange (ETDEWEB)

    Yakubov, D.Kh.; Yarmukhamedov, A.R.

    1979-01-01

    A description is given of the earth crust movements in Tashkent, Fergon, and Kyzylkum polygon. The intensity of those movements was found to diminish as one proceeds from the mountains to the foothills and the plains. Differentiated movements were identified in fracture zones. 13 references.

  3. Modeling viscoelastic deformation of the earth due to surface loading by commercial finite element package - ABAQUS

    Science.gov (United States)

    Kit Wong, Ching; Wu, Patrick

    2017-04-01

    Wu (2004) developed a transformation scheme to model viscoelatic deformation due to glacial loading by commercial finite element package - ABAQUS. Benchmark tests confirmed that this method works extremely well on incompressible earth model. Bangtsson & Lund (2008),however, showed that the transformation scheme would lead to incorrect results if compressible material parameters are used. Their study implies that Wu's method of stress transformation is inadequate to model the load induced deformation of a compressible earth under the framework of ABAQUS. In light of this, numerical experiments are carried out to find if there exist other methods that serve this purpose. All the tested methods are not satisfying as the results failed to converge through iterations, except at the elastic limit. Those tested methods will be outlined and the results will be presented. Possible reasons of failure will also be discussed. Bängtsson, E., & Lund, B. (2008). A comparison between two solution techniques to solve the equations of glacially induced deformation of an elastic Earth. International journal for numerical methods in engineering, 75(4), 479-502. Wu, P. (2004). Using commercial finite element packages for the study of earth deformations, sea levels and the state of stress. Geophysical Journal International, 158(2), 401-408.

  4. Seasonal Variations of the Earth's Gravitational Field: An Analysis of Atmospheric Pressure, Ocean Tidal, and Surface Water Excitation

    Science.gov (United States)

    Dong, D,; Gross, R.S.; Dickey, J.

    1996-01-01

    Monthly mean gravitational field parameters (denoted here as C(sub even)) that represent linear combinations of the primarily even degree zonal spherical harmonic coefficients of the Earth's gravitational field have been recovered using LAGEOS I data and are compared with those derived from gridded global surface pressure data of the National meteorological center (NMC) spanning 1983-1992. The effect of equilibrium ocean tides and surface water variations are also considered. Atmospheric pressure and surface water fluctuations are shown to be the dominant cause of observed annual C(sub even) variations. Closure with observations is seen at the 1sigma level when atmospheric pressure, ocean tide and surface water effects are include. Equilibrium ocean tides are shown to be the main source of excitation at the semiannual period with closure at the 1sigma level seen when both atmospheric pressure and ocean tide effects are included. The inverted barometer (IB) case is shown to give the best agreement with the observation series. The potential of the observed C(sub even) variations for monitoring mass variations in the polar regions of the Earth and the effect of the land-ocean mask in the IB calculation are discussed.

  5. Scaling behaviour of randomly alternating surface growth processes

    CERN Document Server

    Raychaudhuri, S

    2002-01-01

    The scaling properties of the roughness of surfaces grown by two different processes randomly alternating in time are addressed. The duration of each application of the two primary processes is assumed to be independently drawn from given distribution functions. We analytically address processes in which the two primary processes are linear and extend the conclusions to nonlinear processes as well. The growth scaling exponent of the average roughness with the number of applications is found to be determined by the long time tail of the distribution functions. For processes in which both mean application times are finite, the scaling behaviour follows that of the corresponding cyclical process in which the uniform application time of each primary process is given by its mean. If the distribution functions decay with a small enough power law for the mean application times to diverge, the growth exponent is found to depend continuously on this power-law exponent. In contrast, the roughness exponent does not depe...

  6. High surface area carbon and process for its production

    Science.gov (United States)

    Romanos, Jimmy; Burress, Jacob; Pfeifer, Peter; Rash, Tyler; Shah, Parag; Suppes, Galen

    2016-12-13

    Activated carbon materials and methods of producing and using activated carbon materials are provided. In particular, biomass-derived activated carbon materials and processes of producing the activated carbon materials with prespecified surface areas and pore size distributions are provided. Activated carbon materials with preselected high specific surface areas, porosities, sub-nm (<1 nm) pore volumes, and supra-nm (1-5 nm) pore volumes may be achieved by controlling the degree of carbon consumption and metallic potassium intercalation into the carbon lattice during the activation process.

  7. Technical Note: Coupling of chemical processes with the Modular Earth Submodel System (MESSy) submodel TRACER

    Science.gov (United States)

    Jöckel, P.; Kerkweg, A.; Buchholz-Dietsch, J.; Tost, H.; Sander, R.; Pozzer, A.

    2008-03-01

    The implementation of processes related to chemistry into Earth System Models and their coupling within such systems requires the consistent description of the chemical species involved. We provide a tool (written in Fortran95) to structure and manage information about constituents, hereinafter referred to as tracers, namely the Modular Earth Submodel System (MESSy) generic (i.e., infrastructure) submodel TRACER. With TRACER it is possible to define a multitude of tracer sets, depending on the spatio-temporal representation (i.e., the grid structure) of the model. The required information about a specific chemical species is split into the static meta-information about the characteristics of the species, and its (generally in time and space variable) abundance in the corresponding representation. TRACER moreover includes two submodels. One is TRACER_FAMILY, an implementation of the tracer family concept. It distinguishes between two types: type-1 families are usually applied to handle strongly related tracers (e.g., fast equilibrating species) for a specific process (e.g., advection). In contrast to this, type-2 families are applied for tagging techniques. Tagging means the artificial decomposition of one or more species into parts, which are additionally labelled (e.g., by the region of their primary emission) and then processed as the species itself. The type-2 family concept is designed to conserve the linear relationship between the family and its members. The second submodel is TRACER_PDEF, which corrects and budgets numerical negative overshoots that arise in many process implementations due to the numerical limitations (e.g., rounding errors). The submodel therefore guarantees the positive definiteness of the tracers and stabilises the integration scheme. As a by-product, it further provides a global tracer mass diagnostic. Last but not least, we present the submodel PTRAC, which allows the definition of tracers via a Fortran95 namelist, as a complement to

  8. Space solar power stations. Problems of energy generation and using its on the earth surface and nearest cosmos

    Science.gov (United States)

    Sinkevich, OA; Gerasimov, DN; Glazkov, VV

    2017-11-01

    Three important physical and technical problems for solar power stations (SPS) are considered: collection of solar energy and effective conversion of this energy to electricity in space power stations, energy transportation by the microwave beam to the Earth surface and direct utilization of the microwave beam energy for global environmental problems. Effectiveness of solar energy conversion into electricity in space power stations using gas and steam turbines plants, and magneto-hydrodynamic generator (MHDG) are analyzed. The closed cycle MHDG working on non–equilibrium magnetized plasmas of inert gases seeded with the alkaline metal vapors are considered. The special emphases are placed on MHDG and gas-turbine installations that are operating without compressor. Also opportunities for using the produced by space power stations energy for ecological needs on Earth and in Space are discussed.

  9. A Modified Surface on Titanium Deposited by a Blasting Process

    Directory of Open Access Journals (Sweden)

    Caroline O’Sullivan

    2011-09-01

    Full Text Available Hydroxyapatite (HA coating of hard tissue implants is widely employed for its biocompatible and osteoconductive properties as well as its improved mechanical properties. Plasma technology is the principal deposition process for coating HA on bioactive metals for this application. However, thermal decomposition of HA can occur during the plasma deposition process, resulting in coating variability in terms of purity, uniformity and crystallinity, which can lead to implant failure caused by aseptic loosening. In this study, CoBlastTM, a novel blasting process has been used to successfully modify a titanium (V substrate with a HA treatment using a dopant/abrasive regime. The impact of a series of apatitic abrasives under the trade name MCD, was investigated to determine the effect of abrasive particle size on the surface properties of both microblast (abrasive only and CoBlast (HA/abrasive treatments. The resultant HA treated substrates were compared to substrates treated with abrasive only (microblasted and an untreated Ti. The HA powder, apatitic abrasives and the treated substrates were characterized for chemical composition, coating coverage, crystallinity and topography including surface roughness. The results show that the surface roughness of the HA blasted modification was affected by the particle size of the apatitic abrasives used. The CoBlast process did not alter the chemistry of the crystalline HA during deposition. Cell proliferation on the HA surface was also assessed, which demonstrated enhanced osteo-viability compared to the microblast and blank Ti. This study demonstrates the ability of the CoBlast process to deposit HA coatings with a range of surface properties onto Ti substrates. The ability of the CoBlast technology to offer diversity in modifying surface topography offers exciting new prospects in tailoring the properties of medical devices for applications ranging from dental to orthopedic settings.

  10. Empirical assessment of the validity limits of the surface wave full ray theory using realistic 3-D Earth models

    KAUST Repository

    Parisi, Laura

    2016-02-10

    The surface wave full ray theory (FRT) is an efficient tool to calculate synthetic waveforms of surface waves. It combines the concept of local modes with exact ray tracing as a function of frequency, providing a more complete description of surface wave propagation than the widely used great circle approximation (GCA). The purpose of this study is to evaluate the ability of the FRT approach to model teleseismic long-period surface waveforms (T ∼ 45–150 s) in the context of current 3-D Earth models to empirically assess its validity domain and its scope for future studies in seismic tomography. To achieve this goal, we compute vertical and horizontal component fundamental mode synthetic Rayleigh waveforms using the FRT, which are compared with calculations using the highly accurate spectral element method. We use 13 global earth models including 3-D crustal and mantle structure, which are derived by successively varying the strength and lengthscale of heterogeneity in current tomographic models. For completeness, GCA waveforms are also compared with the spectral element method. We find that the FRT accurately predicts the phase and amplitude of long-period Rayleigh waves (T ∼ 45–150 s) for almost all the models considered, with errors in the modelling of the phase (amplitude) of Rayleigh waves being smaller than 5 per cent (10 per cent) in most cases. The largest errors in phase and amplitude are observed for T ∼ 45 s and for the three roughest earth models considered that exhibit shear wave anomalies of up to ∼20 per cent, which is much larger than in current global tomographic models. In addition, we find that overall the GCA does not predict Rayleigh wave amplitudes well, except for the longest wave periods (T ∼ 150 s) and the smoothest models considered. Although the GCA accurately predicts Rayleigh wave phase for current earth models such as S20RTS and S40RTS, FRT\\'s phase errors are smaller, notably for the shortest wave periods considered (T

  11. Electrode structure analysis and surface characterization for lithium-ion cells simulated low-Earth-orbit satellite operation. II: Electrode surface characterization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xianming; Yamada, Chisa; Naito, Hitoshi; Segami, Go; Kibe, Koichi [Institute of Space Technology and Aeronautics, Japan Aerospace Exploration Agency, Tsukuba Space Center, Sengen 2-1-1, Ibaraki 305-8505 (Japan); Hironaka, Toshiya; Hayashi, Eiji; Sakiyama, Yoko; Takahashi, Yoshikazu [Toray Research Center, Inc., Sonoyama 3-3-7, Otsu, Shiga 520-8567 (Japan)

    2007-06-01

    As a sequence work to investigate the performance-degradation mechanism of an aged commercial laminated lithium-ion cell experiencing 4350-cycle charge-discharge in a simulated low-Earth-orbit (LEO) satellite operation, we performed the surface characterization of LiCoO{sub 2} cathode and graphite anode by Fourier transform infrared-Attenuated total reflection (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS) analysis in this work. Overall, the graphite anode had a larger change in surface chemistry than that of the LiCoO{sub 2} cathode. Except the common surface components, we detected Co metal at the aged graphite surface in the first time. This Co metal deposition was believed to originate from Co{sup 2+} dissolution from LiCoO{sub 2} cathode during prolonged cycling, and detrimental to structure stability of LiCoO{sub 2} cathode which was a main cause of cell capacity loss. The amount of surface-film component was also estimated by FTIR analysis. Though the total amount of surface film increased, the organic (inorganic) surface film decreased (increased) with prolonged cycling. (author)

  12. Regional scale hydrology with a new land surface processes model

    Science.gov (United States)

    Laymon, Charles; Crosson, William

    1995-01-01

    Through the CaPE Hydrometeorology Project, we have developed an understanding of some of the unique data quality issues involved in assimilating data of disparate types for regional-scale hydrologic modeling within a GIS framework. Among others, the issues addressed here include the development of adequate validation of the surface water budget, implementation of the STATSGO soil data set, and implementation of a remote sensing-derived landcover data set to account for surface heterogeneity. A model of land surface processes has been developed and used in studies of the sensitivity of surface fluxes and runoff to soil and landcover characterization. Results of these experiments have raised many questions about how to treat the scale-dependence of land surface-atmosphere interactions on spatial and temporal variability. In light of these questions, additional modifications are being considered for the Marshall Land Surface Processes Model. It is anticipated that these techniques can be tested and applied in conjunction with GCIP activities over regional scales.

  13. The impact of transport processes on rare earth element patterns in marine authigenic and biogenic phosphates

    Science.gov (United States)

    Auer, Gerald; Reuter, Markus; Hauzenberger, Christoph A.; Piller, Werner E.

    2017-04-01

    Rare earth elements (REEs) are commonly used proxies to reconstruct water chemistry and oxygen saturation during the formation of authigenic and biogenic phosphates in marine environments. In the modern ocean REEs exhibit a distinct pattern with enrichment of heavy REEs and strong depletion in cerium (Ce). The wide range of REE enrichment patterns found in ancient marine phosphates lead to the proposition that water chemistry has been very different in the Earth's past. However, both early and late diagenesis are known to affect REE signatures in phosphates altering primary marine signals. Herein we present a dataset of REE signatures in 38 grain specific LA-ICP-MS measurements of isolated phosphate and carbonate grains in three discrete rock samples. The phosphates mainly consist of authigenic phosphates and phosphatized microfossils that formed in a microbially mediated micro-milieu. In addition, isolated biogenic and reworked phosphatic grains are also present. The phosphates are emplaced in bioclastic grain- to packstones deposited on a carbonate ramp setting in the central Mediterranean Sea during the middle Miocene Monterey event. The results reveal markedly different REE patterns (normalized to the Post Archean Australian Shale standard) in terms of total enrichment and pattern shape. Analyses of REE diagenesis proxies show that diagenetic alteration affected the samples only to a minor degree. Grain shape and REE patterns together indicate that authigenic, biogenic and reworked phosphates have distinct REE patterns irrespective of the sample. Our study shows that while REE patterns in phosphates do reflect water chemistry during authigenesis, they are often already heavily altered during reworking, a process, which can occur in geologically negligible timespans. REE patterns are therefore more likely to reflect complex enrichment processes after their formation. Similarities in the REE patterns of reworked and biogenic phosphate further suggest that the

  14. Finite amplitudes helical waves on the surface of the conducting fluid earth core as an example of the self-exciting homopolar heterogeneous dynamo

    Directory of Open Access Journals (Sweden)

    V. V. Glazkov

    2006-01-01

    Full Text Available Helical waves of the finite amplitude on a surface of the fluid conducting Earth core are examined for generation of the magnetic field. Estimates are made for the differentially rotating cylindrical conducting fluid body, with the helical surface wave structure on its top. This structure is similar to the self-exciting Faraday-disk homopolar heterogeneous dynamo. Estimations of angular velocity and magnetic field magnitude for a polar vortex on the surface of the Earth's liquid outer core gives reasonable numbers and proves this hypothesis to be of value for further detailed analysis. As magnetic field generation by the helical structure is a surface effect, it is possible to find connection between Earth magnetic field fluctuations and fast relief changes on the iron fluid core – the silicate mantle boundary of the Earth.

  15. Implementation of Web Processing Services (WPS) over IPSL Earth System Grid Federation (ESGF) node

    Science.gov (United States)

    Kadygrov, Nikolay; Denvil, Sebastien; Carenton, Nicolas; Levavasseur, Guillaume; Hempelmann, Nils; Ehbrecht, Carsten

    2016-04-01

    The Earth System Grid Federation (ESGF) is aimed to provide access to climate data for the international climate community. ESGF is a system of distributed and federated nodes that dynamically interact with each other. ESGF user may search and download climatic data, geographically distributed over the world, from one common web interface and through standardized API. With the continuous development of the climate models and the beginning of the sixth phase of the Coupled Model Intercomparison Project (CMIP6), the amount of data available from ESGF will continuously increase during the next 5 years. IPSL holds a replication of the different global and regional climate models output, observations and reanalysis data (CMIP5, CORDEX, obs4MIPs, etc) that are available on the IPSL ESGF node. In order to let scientists perform analysis of the models without downloading vast amount of data the Web Processing Services (WPS) were installed at IPSL compute node. The work is part of the CONVERGENCE project founded by French National Research Agency (ANR). PyWPS implementation of the Web processing Service standard from Open Geospatial Consortium (OGC) in the framework of birdhouse software is used. The processes could be run by user remotely through web-based WPS client or by using command-line tool. All the calculations are performed on the server side close to the data. If the models/observations are not available at IPSL it will be downloaded and cached by WPS process from ESGF network using synda tool. The outputs of the WPS processes are available for download as plots, tar-archives or as NetCDF files. We present the architecture of WPS at IPSL along with the processes for evaluation of the model performance, on-site diagnostics and post-analysis processing of the models output, e.g.: - regriding/interpolation/aggregation - ocgis (OpenClimateGIS) based polygon subsetting of the data - average seasonal cycle, multimodel mean, multimodel mean bias - calculation of the

  16. Innovative Application of Mechanical Activation for Rare Earth Elements Recovering: Process Optimization and Mechanism Exploration

    Science.gov (United States)

    Tan, Quanyin; Deng, Chao; Li, Jinhui

    2016-01-01

    With the rapidly expanding use of fluorescent lamps (FLs) and increasing interest in conservation and sustainable utilization of critical metals such as rare earth elements (REEs), the recovering of REEs from phosphors in waste FLs is becoming a critical environmental and economic issue. To effectively recycle REEs with metallurgical methods, mechanical activation by ball milling was introduced to pretreat the waste phosphors. This current study put the emphasis on the mechanical activation and leaching processes for REEs, and explored the feasibility of the method from both theoretical and practical standpoints. Results showed physicochemical changes of structural destruction and particle size reduction after mechanical activation, leading to the easy dissolution of REEs in the activated samples. Under optimal conditions, dissolution yields of 89.4%, 93.1% and 94.6% for Tb, Eu and Y, respectively, were achieved from activated waste phosphors using hydrochloric acid as the dissolution agent. The shrinking core model proved to be the most applicable for the leaching procedure, with an apparent activation energy of 10.96 ± 2.79 kJ/mol. This novel process indicates that mechanical activation is an efficient method for recovering REEs from waste phosphors, and it has promising potential for REE recovery with low cost and high efficiency.

  17. The effects of magnetospheric processes on relativistic electron dynamics in the Earth's outer radiation belt

    Science.gov (United States)

    Tang, C. L.; Wang, Y. X.; Ni, B.; Su, Z. P.; Reeves, G. D.; Zhang, J.-C.; Baker, D. N.; Spence, H. E.; Funsten, H. O.; Blake, J. B.

    2017-10-01

    Using the electron phase space density (PSD) data measured by Van Allen Probe A from January 2013 to April 2015, we investigate the effects of magnetospheric processes on relativistic electron dynamics in the Earth's outer radiation belt during 50 geomagnetic storms. A statistical study shows that the maximum electron PSDs for various μ (μ = 630, 1096, 2290, and 3311 MeV/G) at L* 4.0 after the storm peak have good correlations with storm intensity (cc 0.70). This suggests that the occurrence and magnitude of geomagnetic storms are necessary for relativistic electron enhancements at the inner edge of the outer radiation belt (L* = 4.0). For moderate or weak storm events (SYM-Hmin > -100 nT) with weak substorm activity (AEmax 0.77). For storm events with intense substorms after the storm peak, relativistic electron enhancements at L* = 4.5 and 5.0 are observed. This shows that intense substorms during the storm recovery phase are crucial to relativistic electron enhancements in the heart of the outer radiation belt. Our statistics study suggests that magnetospheric processes during geomagnetic storms have a significant effect on relativistic electron dynamics.

  18. Graphics Processing Unit (GPU) Acceleration of the Goddard Earth Observing System Atmospheric Model

    Science.gov (United States)

    Putnam, Williama

    2011-01-01

    The Goddard Earth Observing System 5 (GEOS-5) is the atmospheric model used by the Global Modeling and Assimilation Office (GMAO) for a variety of applications, from long-term climate prediction at relatively coarse resolution, to data assimilation and numerical weather prediction, to very high-resolution cloud-resolving simulations. GEOS-5 is being ported to a graphics processing unit (GPU) cluster at the NASA Center for Climate Simulation (NCCS). By utilizing GPU co-processor technology, we expect to increase the throughput of GEOS-5 by at least an order of magnitude, and accelerate the process of scientific exploration across all scales of global modeling, including: The large-scale, high-end application of non-hydrostatic, global, cloud-resolving modeling at 10- to I-kilometer (km) global resolutions Intermediate-resolution seasonal climate and weather prediction at 50- to 25-km on small clusters of GPUs Long-range, coarse-resolution climate modeling, enabled on a small box of GPUs for the individual researcher After being ported to the GPU cluster, the primary physics components and the dynamical core of GEOS-5 have demonstrated a potential speedup of 15-40 times over conventional processor cores. Performance improvements of this magnitude reduce the required scalability of 1-km, global, cloud-resolving models from an unfathomable 6 million cores to an attainable 200,000 GPU-enabled cores.

  19. Monitoring tablet surface roughness during the film coating process

    DEFF Research Database (Denmark)

    Seitavuopio, Paulus; Heinämäki, Jyrki; Rantanen, Jukka

    2006-01-01

    The purpose of this study was to evaluate the change of surface roughness and the development of the film during the film coating process using laser profilometer roughness measurements, SEM imaging, and energy dispersive X-ray (EDX) analysis. Surface roughness and texture changes developing during...... the process of film coating tablets were studied by noncontact laser profilometry and scanning electron microscopy (SEM). An EDX analysis was used to monitor the magnesium stearate and titanium dioxide of the tablets. The tablet cores were film coated with aqueous hydroxypropyl methylcellulose, and the film...... coating was performed using an instrumented pilot-scale side-vented drum coater. The SEM images of the film-coated tablets showed that within the first 30 minutes, the surface of the tablet cores was completely covered with a thin film. The magnesium signal that was monitored by SEM-EDX disappeared after...

  20. Integrated solution for the complete remote sensing process - Earth Observation Mission Control Centre (EOMC2)

    Science.gov (United States)

    Czapski, Paweł

    2016-07-01

    We are going to show the latest achievements of the Remote Sensing Division of the Institute of Aviation in the area of remote sensing, i.e. the project of the integrated solution for the whole remote sensing process ranging from acquiring to providing the end user with required information. Currently, these tasks are partially performed by several centers in Poland, however there is no leader providing an integrated solution. Motivated by this fact, the Earth Observation Mission Control Centre (EOMC2) was established in the Remote Sensing Division of the Institute of Aviation that will provide such a comprehensive approach. Establishing of EOMC2 can be compared with creating Data Center Aerial and Satellite Data Centre (OPOLIS) in the Institute of Geodesy and Cartography in the mid-70s in Poland. OPOLIS was responsible for broadly defined data processing, it was a breakthrough innovation that initiated the use of aerial image analysis in Poland. Operation center is a part of the project that will be created, which in comparison with the competitors will provide better solutions, i.e.: • Centralization of the acquiring, processing, publishing and archiving of data, • Implementing elements of the INSPIRE directive recommendations on spatial data management, • Providing the end-user with information in the near real-time, • Ability of supplying the system with images of various origin (aerial, satellite, e.g. EUMETCast, Sentinel, Landsat) and diversity of telemetry data, data aggregation and using the same algorithms to images obtained from different sources, • System reconfiguration and batch processing of large data sets at any time, • A wide range of potential applications: precision agriculture, environmental protection, crisis management and national security, aerial, small satellite and sounding rocket missions monitoring.

  1. EXPERIMENTAL VALIDATION OF CUMULATIVE SURFACE LOCATION ERROR FOR TURNING PROCESSES

    Directory of Open Access Journals (Sweden)

    Adam K. Kiss

    2016-02-01

    Full Text Available The aim of this study is to create a mechanical model which is suitable to investigate the surface quality in turning processes, based on the Cumulative Surface Location Error (CSLE, which describes the series of the consecutive Surface Location Errors (SLE in roughing operations. In the established model, the investigated CSLE depends on the currently and the previously resulted SLE by means of the variation of the width of cut. The phenomenon of the system can be described as an implicit discrete map. The stationary Surface Location Error and its bifurcations were analysed and flip-type bifurcation was observed for CSLE. Experimental verification of the theoretical results was carried out.

  2. Particle dry deposition to water surfaces: Processes and consequences

    DEFF Research Database (Denmark)

    Pryor, S.C.; Barthelmie, R.J.

    2000-01-01

    Algal blooms (increased abundance of phytoplankton) are an increasingly common phenomenon which has been causally linked to increased fluxes of nutrient (particularly nitrogenous) compounds to aquatic ecosystems. These blooms have implications for water quality and human health in addition...... flux to coastal waters, atmosphere-surface exchange represents a significant component of the total flux and may be particularly critical during the summertime when both the riverine input and ambient nutrient concentrations are often at a minimum. In this chapter, we present an overview...... of the physical and chemical processes which dictate the quantity (and direction) of atmosphere-surface fluxes of trace chemicals to (and above) water surfaces with particular emphasis on the role of particles. Dry deposition (transfer to the surface in the absence of precipitation) of particles is determined...

  3. Biofunctionalization of titanium surfaces for osseintegration process improvement

    Energy Technology Data Exchange (ETDEWEB)

    Sevilla, P; Godoy, M; Salvagni, E; Rodriguez, D; Gil, F J, E-mail: pablo.sevilla@upc.edu

    2010-11-01

    This study aims to improve the osseointegration of titanium implants through surface immobilization of peptides that induce a beneficial biological response. This was carried out biofunctionalizating titanium surfaces by silanization and subsequent covalent binding of a peptide with a sequence that promotes cell adhesion. Objective: The development of a new technique of immobilization of oligopeptides on the surface of titanium by using 3-chloropropyltrietoxisilane (CPTES) as bonding agent between the surface of titanium and the peptide. Materials and methods: A physicochemical characterization of the surfaces through the techniques of XPS, ToF-SIMS and contact angle was performed. Also cell adhesion studies have been conducted to evaluate in vitro biological response. Results: Through the process of silanization the titanium surface is completely covered with CPTES, which allows the subsequent accession of oligopeptides. The cell adhesion results show a higher cell adhesion and cell extension on biofunctionalized samples. Conclusions: We developed a system of covalent binding of oligopeptides on titanium surfaces that can modify the biological response of the attached cells.

  4. The Gas-Surface Interaction of a Human-Occupied Spacecraft with a Near-Earth Object

    Science.gov (United States)

    Farrell, W. M.; Hurley, D. M.; Poston, M. J.; Zimmerman, M. I.; Orlando, T. M.; Hibbitts, C. A.; Killen, R. M.

    2016-01-01

    NASA's asteroid redirect mission (ARM) will feature an encounter of the human-occupied Orion spacecraft with a portion of a near- Earth asteroid (NEA) previously placed in orbit about the Moon by a capture spacecraft. Applying a shuttle analog, we suggest that the Orion spacecraft should have a dominant local water exosphere, and that molecules from this exosphere can adsorb onto the NEA. The amount of adsorbed water is a function of the defect content of the NEA surface, with retention of shuttle-like water levels on the asteroid at 10(exp 15) H2O's/m2 for space weathered regolith at T approximately 300 K.

  5. The roles of rare-earth dopants in solution-processed ZnO-based transparent conductive oxides

    Science.gov (United States)

    Hu, Wenbing; Peterson, Rebecca L.

    2017-09-01

    Zinc oxide (ZnO) doped with group III A elements such as boron, aluminum, gallium, and indium forms a transparent conductive oxide with low sheet resistance. The group III B rare-earth elements scandium (Sc) and yttrium (Y) also have three valence electrons and thus may similarly act as n-type dopants. Here, we use an ink process to deposit Sc:ZnO and Y:ZnO nanocrystalline films with Sc and Y concentration of a few atomic percent. After annealing in forming gas, the resistivity of all films was reduced by four orders of magnitude. However, the Sc or Y-doped ZnO films are more resistive than undoped ZnO, and their resistivity is more strongly dependent on film thickness; Sc and Y do not act as electron donors. The cause of this anomalous behavior was studied by electrical measurements, x-ray photoelectron spectroscopy, and scanning spreading resistance spectroscopy. The high resistivity of Y:ZnO and Sc:ZnO compared to ZnO is attributed to phase segregation of insulating yttria and scandia at the nanocrystalline grain boundaries. The strong thickness dependence of Sc:ZnO and Y:ZnO film resistivity is due to surface and bulk depletion, which may be enhanced by the slowing of grain growth caused by the insulating grain boundary layer.

  6. Physical Characteristics and Processes of 100-m-scale raised-rim depressions (RRD's) on Earth: application to Mars

    Science.gov (United States)

    Burr, D. M.; Bruno, B.; Jaeger, W. L.; Lanagan, P. D.; Miyamoto, H.; Soare, R.; Wan Bun Tseung, J.

    2005-12-01

    100-m-scale raised-rim depressions (RRD's) of various origins are found on both Earth and Mars. We define RRD's morphologically, as circular, elongate, or irregularly shaped forms having raised rims encircling lower elevation terrain. Terrestrial RRD's include phreatomagmatic cones, basaltic ring structures, collapsing or collapsed pingos, rimmed kettle holes, and mud volcanoes. Terrestrial experience commonly guides extra-terrestrial investigations, so these terrestrial types of RRD's are also the types that have been commonly hypothesized for RRD's on Mars, although other origins (e.g., secondary impacts onto deflating surfaces) are also likely on Mars. Identifying the origins of Martian RRD's is useful because different types of RRD's imply different geological processes (and therefore have different astrobiological connotations). Being of a similar shape and size in plan view, different types of RRD's are often difficult to classify remotely. However, each of these types of RRD's has specific geomorphic characteristics that can be remotely assessed. Based on terrestrial studies, we present guidelines of a scale applicable to new current and near-future spacecraft data to aid in identifying various types of RRD's on Mars. This presentation will entail discussion of selected types of RRD's, including their geneses, morphologic characteristics, distributions, and common geological associations. The RRD's are grouped according to primary origin, ie., volcanic, sedimentologic, and other. In summary, we present some guidelines for classifying RRD's on Mars.

  7. On testing of the photometer-polarimeter UVP layout using a telescope on Earth's surface

    Science.gov (United States)

    Nevodovskyi, P. V.; Vidmachenko, A. P.; Morozhenko, O. V.; Zbrutskyi, O.; Ivakhiv, O. V.

    2016-08-01

    One of the causes of climate change (changing of concentration of stratospheric ozone) - is variations due to aerosol optical thickness in the upper layers of Earth's atmosphere. To solve the problem is necessary to make a space experiment to receive polarization observational data. Their analysis will: determine the value of the real part of the refractive index, the size of the stratospheric aerosol, optical thickness of the stratospheric aerosol layer, investigate aerosol's layer horizontal structure and its changes over time. Main Astronomical Observatory of NAS of Ukraine jointly with the National Technical University of Ukraine "KPI" and National University "Lviv Polytechnic" for a long time working on the design of polarimeter to study the stratospheric layer of the Earth from board of artificial satellites. During this time accumulated a great experience in such work, and created a layout of compact board ultraviolet polarimeter UFP [1-4]. For testing of ground variant of layout of UFP, it is installed on the telescope AZT-2 of the Main Astronomical Observatory NAS of Ukraine (Kyiv). Using it we plan to investigate the possibility of determining the degree of polarization of the twilight glow of Earth's atmosphere, and implementation of this technique in the development of space experiment on investigation of the stratospheric aerosol from space. For this purpose we develop a special set of equipment that will adapt the layout for working of UFP with telescope AZT-2, and carry out the above mentioned work (see. in [5-7]). References. 1. P. Nevodovskyi, O. Morozhenko, A. Vidmachenko, O. Ivakhiv, M. Geraimchuk, O. Zbrutskyi. Tiny Ultraviolet Polarimeter for Earth Stratosphere from Space Investigation // Proceedings of 8th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS'2015). 24-26 September 2015, Proceedings. Warsaw, Poland. Vol.81, p. 28-32. 2. Nevodovsksiy P. V., Morozhenko A

  8. Evaluation of Select Surface Processing Techniques for In Situ Application During the Additive Manufacturing Build Process

    Science.gov (United States)

    Book, Todd A.; Sangid, Michael D.

    2016-07-01

    Although additive manufacturing offers numerous performance advantages for different applications, it is not being used for critical applications due to uncertainties in structural integrity as a result of innate process variability and defects. To minimize uncertainty, the current approach relies on the concurrent utilization of process monitoring, post-processing, and non-destructive inspection in addition to an extensive material qualification process. This paper examines an alternative approach by evaluating the application of select surface process techniques, to include sliding severe plastic deformation (SPD) and fine particle shot peening, on direct metal laser sintering-produced AlSi10Mg materials. Each surface processing technique is compared to baseline as-built and post-processed samples as a proof of concept for surface enhancement. Initial results pairing sliding SPD with the manufacture's recommended thermal stress relief cycle demonstrated uniform recrystallization of the microstructure, resulting in a more homogeneous distribution of strain among the microstructure than as-built or post-processed conditions. This result demonstrates the potential for the in situ application of various surface processing techniques during the layerwise direct metal laser sintering build process.

  9. Surface modification of magnesium hydroxide using vinyltriethoxysilane by dry process

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Shengjie [Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008 (China); Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Chinese Academy of Sciences, Xining 810008 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Lijuan, E-mail: lilj@isl.ac.cn [Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008 (China); Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Chinese Academy of Sciences, Xining 810008 (China); Xu, Defang; Zhu, Donghai; Liu, Zhiqi; Nie, Feng [Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008 (China); Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Chinese Academy of Sciences, Xining 810008 (China)

    2016-09-30

    Highlights: • A modification mechanism for magnesium hydroxide using silane by dry process was proposed. • Si−O−Mg bonds were formed directly by the reaction between Si-OC{sub 2}H{sub 5} and hydroxyl groups of magnesium hydroxide. • Dispersibility and compatibility of modified magnesium hydroxide improved in organic phase. - Abstract: In order to improve the compatibility between magnesium hydroxide (MH) and polymer matrix, the surface of MH was modified using vinyltriethoxysilane (VTES) by dry process and the interfacial interaction between MH and VTES was also studied. Zeta potential measurements implied that the MH particles had better dispersion and less aggregation after modification. Sedimentation tests showed that the surface of MH was transformed from hydrophilic to hydrophobic, and the dispersibility and the compatibility of MH particles significantly improved in the organic phase. Scanning electronic microscopy (SEM), Transmission electron microscopy (TEM) and X-ray powder diffraction (XRD) analyses showed that a thin layer had formed on the surface of the modified MH, but did not alter the material’s crystalline phase. Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectra (XPS) and Thermogravimetric analysis (TGA) showed that the VTES molecules bound strongly to the surface of MH after modification. Chemical bonds (Si−O−Mg) formed by the reaction between Si-OC{sub 2}H{sub 5} and hydroxyl group of MH, also there have physical adsorption effect in the interface simultaneously. A modification mechanism of VTES on the MH surface by dry process was proposed, which different from the modification mechanism by wet process.

  10. Electronic dissipation processes during chemical reactions on surfaces

    CERN Document Server

    Stella, Kevin

    2012-01-01

    Hauptbeschreibung Every day in our life is larded with a huge number of chemical reactions on surfaces. Some reactions occur immediately, for others an activation energy has to be supplied. Thus it happens that though a reaction should thermodynamically run off, it is kinetically hindered. Meaning the partners react only to the thermodynamically more stable product state within a mentionable time if the activation energy of the reaction is supplied. With the help of catalysts the activation energy of a reaction can be lowered. Such catalytic processes on surfaces are widely used in industry. A

  11. Response surface optimization of osmotic dehydration process for aonla slices.

    Science.gov (United States)

    Alam, Md Shafiq; Amarjit, Singh; Sawhney, B K

    2010-01-01

    Response surface methodology was used to investigate the effect of sugar concentration (50-70° Brix), solution temperature (30-60°C), solution to fruit ratio (4:1-8:1) and immersion time (60-180 min) on the water loss, solute gain, rehydration ratio, vitamin-C loss, colour change and sensory overall acceptability of Indian gooseberry (aonla) slices. The optimum process parameters obtained by computer generated response surfaces, canonical analysis and contour plot interpretation were: sugar concentration, 59° Brix solution temperature 51°C, solution to fruit ratio 4:1 and immersion time of 60 min.

  12. [Cell surface carbohydrates are involved in various biological processes].

    Science.gov (United States)

    Bryne, M; Kjaerheim, A; Schreurs, O; Dabelsteen, E

    1992-09-20

    All human cells show carbohydrate structures on the surface. New knowledge about the genetic mechanisms for the synthesis of these carbohydrates and the generation of monoclonal antibodies with high specificity shows that carbohydrates are involved in various cell-cell and cell-matrix interactions. For instance, cell surface carbohydrates seem to be important in connection with fertilization, embryonic development, cell differentiation, cancer, adhesion of microorganisms and immunological processes. This new knowledge will increase our understanding of various biological phenomena, and will thus be of value for diagnosis and treatment of various diseases.

  13. Influence of Surface Processing on the Biocompatibility of Titanium

    Directory of Open Access Journals (Sweden)

    Kornelia Wirsching

    2011-07-01

    Full Text Available Surface conditioning of titanium middle ear implants results in an improved biocompatibility, which can be characterized by the properties of fibroblasts cultured on conditioned surfaces. Titanium has been established as a favorable biomaterial in ossicular chain reconstruction. The epithelization of the surface of the implants is important for their integration and stable positioning in the middle ear. Mouse fibroblast cells were cultured on platelets made from pure Grade 2 titanium. Platelets that had been etched along their production process were compared to unetched platelets. The DNA in the cell nuclei was stained with DAPI and the actin filaments of the cytoskeleton were stained with FITC-conjugated phalloidin in order to analyze the cells grown on etched and unetched platelets by fluorescence microscopy. SEM (scanning electron microscopic images were used to compare the surface structure of etched and unetched titanium platelets. There was a statistically significant increase of the area covered by the cytoplasm and increased actin expression by fibroblasts grown on the etched titanium platelets. In addition, the area of the platelets covered by nuclei on the etched platelets exceeded on average the one on unetched platelets, although this difference was not significant. The SEM pictures comparing unetched and etched titanium platelets showed a clear difference in surface structure. Surface conditioning of titanium implants improved the epithelization by fibroblasts and consequently etched titanium should be the preferred biomaterial for reconstructive middle ear surgery.

  14. The Impact of Benthic Processes on Rare Earth Element and Neodymium Isotope Distributions in the Oceans

    Directory of Open Access Journals (Sweden)

    Brian A. Haley

    2017-12-01

    Full Text Available Neodymium (Nd isotopes are considered a valuable tracer of modern and past ocean circulation. However, the promise of Nd isotope as a water mass tracer is hindered because there is not an entirely self-consistent model of the marine geochemical cycle of rare earth elements (REEs, of which Nd is one. That is, the prevailing mechanisms to describe the distributions of elemental and isotopic Nd are not completely reconciled. Here, we use published [Nd] and Nd isotope data to examine the prevailing model assumptions, and further compare these data to emergent alternative models that emphasize benthic processes in controlling the cycle of marine REEs and Nd isotopes. Our conclusion is that changing from a “top-down” driven model for REE cycling to one of a “bottom-up” benthic source model can provide consistent interpretations of these data for both elemental and isotopic Nd distributions. We discuss the implications such a benthic flux model carries for interpretation of Nd isotope data as a tracer for understanding modern and past changes in ocean circulation.

  15. Effect of cloud cover and surface type on earth's radiation budget derived from the first year of ERBE data

    Science.gov (United States)

    Gibson, G. G.; Denn, F. M.; Young, D. F.; Harrison, E. F.; Minnis, P.; Barkstrom, B. R.

    1990-01-01

    One year of ERBE data is analyzed for variations in outgoing LW and absorbed solar flux. Differences in land and ocean radiation budgets as well as differences between clear-sky and total scenes, including clouds, are studied. The variation of monthly average radiative parameters is examined for February 1985 through January 1986 for selected study regions and on zonal and global scales. ERBE results show significant seasonal variations in both outgoing LW and absorbed SW flux, and a pronounced difference between oceanic and continental surfaces. The main factors determining cloud radiative forcing in a given region are solar insolation, cloud amount, cloud type, and surface properties. The strongest effects of clouds are found in the midlatitude storm tracks over the oceans. Over much of the globe, LW warming is balanced by SW cooling. The annual-global average net cloud forcing shows that clouds have a net cooling effect on the earth for the year.

  16. Sensitivities of surface wave velocities to the medium parameters in a radially anisotropic spherical Earth and inversion strategies

    Directory of Open Access Journals (Sweden)

    Sankar N. Bhattacharya

    2015-11-01

    Full Text Available Sensitivity kernels or partial derivatives of phase velocity (c and group velocity (U with respect to medium parameters are useful to interpret a given set of observed surface wave velocity data. In addition to phase velocities, group velocities are also being observed to find the radial anisotropy of the crust and mantle. However, sensitivities of group velocity for a radially anisotropic Earth have rarely been studied. Here we show sensitivities of group velocity along with those of phase velocity to the medium parameters VSV, VSH , VPV, VPH , h and density in a radially anisotropic spherical Earth. The peak sensitivities for U are generally twice of those for c; thus U is more efficient than c to explore anisotropic nature of the medium. Love waves mainly depends on VSH while Rayleigh waves is nearly independent of VSH . The sensitivities show that there are trade-offs among these parameters during inversion and there is a need to reduce the number of parameters to be evaluated independently. It is suggested to use a nonlinear inversion jointly for Rayleigh and Love waves; in such a nonlinear inversion best solutions are obtained among the model parameters within prescribed limits for each parameter. We first choose VSH, VSV and VPH within their corresponding limits; VPV and h can be evaluated from empirical relations among the parameters. The density has small effect on surface wave velocities and it can be considered from other studies or from empirical relation of density to average P-wave velocity.

  17. Simulation of the surface roughness formation process in finishing

    Energy Technology Data Exchange (ETDEWEB)

    Losev, V.A.; Plyusnin, Y.G.

    1983-09-01

    Geometric, energy, and impulse models were developed to study the interaction of the abrasive and the ground surfaces in finishing. The geometric and energy models describe the process of finishing in the case of the use of tools with a fastened abrasive. The impulse model reflects the real picture of the action of unfastened abrasive grains on the surface being ground. The spectral density of the input signal is determined. The weight function and transfer function are treated. The spectral theory of the linear transformation of the stationary random function is used. On the basis of the experimental data and theoretical solutions, equations are obtained with which it is possible to predict the changes in surface roughness for various abrasive particle sizes.

  18. Influence on surface characteristics of electron beam melting process (EBM) by varying the process parameters

    Science.gov (United States)

    Dolimont, Adrien; Michotte, Sebastien; Rivière-Lorphèvre, Edouard; Ducobu, François; Vivès, Solange; Godet, Stéphane; Henkes, Tom; Filippi, Enrico

    2017-10-01

    The use of additive manufacturing processes keeps growing in aerospace and biomedical industry. Among the numerous existing technologies, the Electron Beam Melting process has advantages (good dimensional accuracy, fully dense parts) and disadvantages (powder handling, support structure, high surface roughness). Analyzes of the surface characteristics are interesting to get a better understanding of the EBM operations. But that kind of analyzes is not often found in the literature. The main goal of this study is to determine if it is possible to improve the surface roughness by modifying some parameters of the process (scan speed function, number of contours, order of contours, etc.) on samples with different thicknesses. The experimental work on the surface roughness leads to a statistical analysis of 586 measures of EBM simple geometry parts.

  19. Carbon Offsets in California: What Role for Earth Scientists in the Policy Process? (Invited)

    Science.gov (United States)

    Cullenward, D.; Strong, A. L.

    2013-12-01

    some offset protocols award credits for activities that would have occurred anyway; by replacing a company's need to acquire an allowance in the carbon market, critics believe that poorly designed offset protocols increase greenhouse gas emissions. Thus, the effectiveness of the policy approach depends on the scientific integrity of the offset protocols. To date, California has approved offset protocols for emissions reductions in four applications: (1) forestry, (2) urban forestry, (3) livestock, and (4) destruction of ozone-depleting substances. In addition, the State is currently considering protocols that would address (5) methane emissions from mining and (6) greenhouse gas reductions from improved rice cultivation practices. These protocols rely heavily on findings from the environmental and earth sciences communities, especially when the protocol subject involves land use or land use change. Yet, due to budget constraints, the Air Resources Board is relying primarily on third-party protocol developers to design and propose the detailed structures under which offset credits will be issued. Despite the fact that any member of the public may participate in the governance regime that leads to protocol approvals, few scientists or scientific organizations provide input into the policy process. We use case studies from several of the California protocols to illustrate ways scientists can apply their skills to a crucial stage of climate policy development.

  20. Self-consistency in reference frames, geocenter definition, and surface loading of the solid Earth

    National Research Council Canada - National Science Library

    Geoffrey Blewitt

    2003-01-01

    ...” if the computed surface displacements functionally accord with load Love number theory. Isomorphic frames are shown to move relative to each other along the direction of the load's center of mass...

  1. Mechanical and tribological properties of ion beam-processed surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kodali, Padma [Univ. of Maryland, College Park, MD (United States)

    1998-01-01

    The intent of this work was to broaden the applications of well-established surface modification techniques and to elucidate the various wear mechanisms that occur in sliding contact of ion-beam processed surfaces. The investigation included characterization and evaluation of coatings and modified surfaces synthesized by three surface engineering methods; namely, beam-line ion implantation, plasma-source ion implantation, and DC magnetron sputtering. Correlation among measured properties such as surface hardness, fracture toughness, and wear behavior was also examined. This dissertation focused on the following areas of research: (1) investigating the mechanical and tribological properties of mixed implantation of carbon and nitrogen into single crystal silicon by beam-line implantation; (2) characterizing the mechanical and tribological properties of diamond-like carbon (DLC) coatings processed by plasma source ion implantation; and (3) developing and evaluating metastable boron-carbon-nitrogen (BCN) compound coatings for mechanical and tribological properties. The surface hardness of a mixed carbon-nitrogen implant sample improved significantly compared to the unimplanted sample. However, the enhancement in the wear factor of this sample was found to be less significant than carbon-implanted samples. The presence of nitrogen might be responsible for the degraded wear behavior since nitrogen-implantation alone resulted in no improvement in the wear factor. DLC coatings have low friction, low wear factor, and high hardness. The fracture toughness of DLC coatings has been estimated for the first time. The wear mechanism in DLC coatings investigated with a ruby slider under a contact stress of 1 GPa was determined to be plastic deformation. The preliminary data on metastable BCN compound coatings indicated high friction, low wear factor, and high hardness.

  2. Phase change in subducted lithosphere, impulse, and quantizing Earth surface deformations

    Science.gov (United States)

    Bowin, C. O.; Yi, W.; Rosson, R. D.; Bolmer, S. T.

    2015-09-01

    The new paradigm of plate tectonics began in 1960 with Harry H. Hess's 1960 realization that new ocean floor was being created today and is not everywhere of Precambrian age as previously thought. In the following decades an unprecedented coming together of bathymetric, topographic, magnetic, gravity, seismicity, seismic profiling data occurred, all supporting and building upon the concept of plate tectonics. Most investigators accepted the premise that there was no net torque amongst the plates. Bowin (2010) demonstrated that plates accelerated and decelerated at rates 10-8 times smaller than plate velocities, and that globally angular momentum is conserved by plate tectonic motions, but few appeared to note its existence. Here we first summarize how we separate where different mass sources may lie within the Earth and how we can estimate their mass. The Earth's greatest mass anomalies arise from topography of the boundary between the metallic nickel-iron core and the silicate mantle that dominate the Earth's spherical harmonic degree 2 and 3 potential field coefficients, and overwhelm all other internal mass anomalies. The mass anomalies due to phase changes in olivine and pyroxene in subducted lithosphere are hidden within the spherical harmonic degree 4-10 packet, and are an order of magnitude smaller than those from the core-mantle boundary. Then we explore the geometry of the Emperor and Hawaiian seamount chains and the 60° bend between them that aids in documenting the slow acceleration during both the Pacific Plate's northward motion that formed the Emperor seamount chain and its westward motion that formed the Hawaiian seamount chain, but it decelerated at the time of the bend (46 Myr). Although the 60° change in direction of the Pacific Plate at of the bend, there appears to have been nary a pause in a passive spreading history for the North Atlantic Plate, for example. This, too, supports phase change being the single driver for plate tectonics and

  3. Application of Anodization Process for Cast Aluminium Surface Properties Enhancement

    Directory of Open Access Journals (Sweden)

    Włodarczyk-Fligier A.

    2016-09-01

    Full Text Available An huge interest is observed in last years in metal matrix composite, mostly light metal based, which have found their applications in many industry branches, among others in the aircraft industry, automotive-, and armaments ones, as well as in electrical engineering and electronics, where one of the most important issue is related to the corrosion resistance, especially on the surface layer of the used aluminium alloys. This elaboration presents the influence of ceramic phase on the corrosion resistance, quality of the surface layer its thickness and structure of an anodic layer formed on aluminium alloys. As test materials it was applied the aluminium alloys Al-Si-Cu and Al-Cu-Mg, for which heat treatment processes and corrosion tests were carried out. It was presented herein grindability test results and metallographic examination, as well. Hardness of the treated alloys with those ones subjected to corrosion process were compared.

  4. Surface processes during purification of InP quantum dots.

    Science.gov (United States)

    Mordvinova, Natalia; Emelin, Pavel; Vinokurov, Alexander; Dorofeev, Sergey; Abakumov, Artem; Kuznetsova, Tatiana

    2014-01-01

    Recently, a new simple and fast method for the synthesis of InP quantum dots by using phosphine as phosphorous precursor and myristic acid as surface stabilizer was reported. Purification after synthesis is necessary to obtain samples with good optical properties. Two methods of purification were compared and the surface processes which occur during purification were studied. Traditional precipitation with acetone is accompanied by a small increase in photoluminescence. It occurs that during the purification the hydrolysis of the indium precursor takes place, which leads to a better surface passivation. The electrophoretic purification technique does not increase luminescence efficiency but yields very pure quantum dots in only a few minutes. Additionally, the formation of In(OH)3 during the low temperature synthesis was explained. Purification of quantum dots is a very significant part of postsynthetical treatment that determines the properties of the material. But this subject is not sufficiently discussed in the literature. The paper is devoted to the processes that occur at the surface of quantum dots during purification. A new method of purification, electrophoresis, is investigated and described in particular.

  5. Surface processes during purification of InP quantum dots

    Directory of Open Access Journals (Sweden)

    Natalia Mordvinova

    2014-08-01

    Full Text Available Recently, a new simple and fast method for the synthesis of InP quantum dots by using phosphine as phosphorous precursor and myristic acid as surface stabilizer was reported. Purification after synthesis is necessary to obtain samples with good optical properties. Two methods of purification were compared and the surface processes which occur during purification were studied. Traditional precipitation with acetone is accompanied by a small increase in photoluminescence. It occurs that during the purification the hydrolysis of the indium precursor takes place, which leads to a better surface passivation. The electrophoretic purification technique does not increase luminescence efficiency but yields very pure quantum dots in only a few minutes. Additionally, the formation of In(OH3 during the low temperature synthesis was explained. Purification of quantum dots is a very significant part of postsynthetical treatment that determines the properties of the material. But this subject is not sufficiently discussed in the literature. The paper is devoted to the processes that occur at the surface of quantum dots during purification. A new method of purification, electrophoresis, is investigated and described in particular.

  6. Maghemite soil nodules reveal the impact of fire on mineralogical and geochemical differentiation at the Earth's surface

    Science.gov (United States)

    Löhr, Stefan C.; Murphy, David T.; Nothdurft, Luke D.; Bolhar, Robert; Piazolo, Sandra; Siegel, Coralie

    2017-03-01

    Fires occur frequently over large parts of the Earth's surface. They potentially exert a significant influence on the mineralogical and geochemical characteristics of an environment that is otherwise considered to be dominated by low temperature processes. We test this hypothesis by comparing the mineralogy and geochemistry of (i) magnetic, iron-rich soil nodules, (ii) non-magnetic iron soil nodules and (iii) a published dataset of surficial sediments from eastern Australia. Maghemite-rich nodules are present in soils from around the world. It has been argued that they are thermal alteration products of non-magnetic precursors, but this remains controversial. We use detailed petrographic and mineralogical analyses to demonstrate that maghemite occurs as part of a high temperature mineral assemblage including hematite and χ-alumina, within a magnetic nodule microfabric indicative of fire-induced dehydroxylation and sintering of non-magnetic precursors at temperatures of up to 600 °C. The genetic link between magnetic and non-magnetic nodules means that their comparison offers insights into the geochemical impact of fire. Our results show that magnetic nodules are depleted in Si, Y, Zr and HREE but enriched in Fe and Cr relative to non-magnetic nodules that occur in close spatial proximity. Magnetic nodules also show variable but distinctly low Y/Ho (21.4 ± 0.4) and Zr/Hf (29.3 ± 0.8) as well as anomalously low La relative to the other LREE. In situ laser ablation analyses show that this is largely due to the presence of χ-alumina that is depleted in HREEs and has extremely low Y/Ho (mainly transport and sedimentation of the readily weathered, high Y/Ho and Zr/Hf cortex material that is a product of thermal alteration of Fe nodules. In addition, since magnetic Fe nodules are demonstrably related to fire, they may represent a promising, directly dateable record of severe fires, which can complement the sedimentary charcoal record.

  7. First Principles Calculation on Equilibrium Si Isotope Fractionation Factors and its Implementation on Si Isotope Distributions in Earth Surface Environments

    Science.gov (United States)

    Liu, Y.; He, H. T.; Zhu, C.

    2014-12-01

    Several important equilibrium Si isotope fractionation factors are calculated here. We use a so-called volume-variable-cluster-model (VVCM) method for solids and the "water-droplet" method for aqueous species for isotope fractionation calculation at the same quantum chemistry level. The calculation results show that several silicate minerals, such as quartz, feldspar, kaolinite, etc., all enrich heavy Si isotopes relative to aqueous H4SiO4 and can be up to 3.3‰ at 25°C, different from most field observations. Meanwhile stable organosilicon complexes can enrich even lighter Si isotopes than aqueous H4SiO4. For explaining the difference between the calculation results and field observations, we calculate the kinetic isotope effect (KIE) associated with the formation of amorphous silica, and find that amorphous silica will enrich extremely light Si isotopes. From amorphous silica to crystalline quartz, the structural adjustment & transition needs getting rid of small amount of Si to re-organize the structure. Light Si isotopes will be preferentially lost and let the final crystalline quartz with a little bit more heavy Si isotopes. However, such late-stage Si heavy isotope enrichment cannot erase the total isotopic signal, crystalline quartz still inherit much light Si isotopic composition from amorphous quartz. That is the reason for the discrepancy between the calculation results and the field observations, because the formation of amorphous quartz is under a non-equilibrium process but theoretical calculations are for equilibrium isotope fractionations. With accurate equilibrium fractionation factors provided here, Si isotope distributions in earth surface environments including soil, groundwater and plants can be further interpreted. We find that δ30Si variations in soil are mainly driven by secondary minerals precipitation and adsorption. Also, bulk soil δ30Si maybe have a parabolic distribution with soil age, with a minimum value at where allophane is

  8. Processing-Microstructure-Crystallographic Texture-Surface Property Relationships in Friction Stir Processing of Titanium

    Science.gov (United States)

    Bahl, Sumit; Nithilaksh, P. L.; Suwas, Satyam; Kailas, Satish V.; Chatterjee, Kaushik

    2017-09-01

    Friction stir processing (FSP) is a solid-state technique for microstructural modification of metallic materials. The aim of this work is to establish processing-microstructure-texture-surface properties relationship in commercially pure titanium (cp-Ti) processed by FSP under different processing conditions. The effect of processing conditions on the microstructural changes and the evolution of crystallographic texture is systematically studied. The changes in the chemical composition of the passive surface layer are characterized by x-ray photoelectron spectroscopy. The corrosion behavior of cp-Ti after FSP is evaluated in simulated body fluid and is related to the microstructure, texture and composition of passive layer. Substantial grain refinement was observed after FSP. Shear type deformation texture evolved during FSP with dynamic restoration processes weakening the overall shear texture. The corrosion resistance improved after processing at lower rotational speed due to the presence of basal planes at the surface and the incorporation of TiN in the passive layer. The results of this study suggest that surface properties of cp-Ti like passive layer and corrosion resistance are altered by FSP and can be controlled using appropriate processing parameters.

  9. Early Student Support for Process Studies of Surface Freshwater Dispersal

    Science.gov (United States)

    2016-06-24

    region to the north, and intrusions of saline w::tter are seen subsurface in the southern part of the section. (c) Black : Amount of heat contained ... Hole Oceanographic Institution REPORT NUMBER Department of Physical Oceanography - MS #29 FINAL Woods Hole , MA 02543 9. SPONSORING/MONITORING AGENCY...ONRREPORT Early Student Support Process Studies of Surface Freshwater Dispersal June 24, 2016 Amala Mahadevan Woods Hole Oceanographic Institution

  10. Wright Valley Sediments as Potential Analogs for Martian Surface Processes

    Science.gov (United States)

    Englert, P. A. J.; Bishop, J. L.; Patel, S.; Gibson, E. K.; Koeberl, C.

    2015-12-01

    The Antarctic Dry Valleys (ADV) may provide a unique terrestrial analog for current Martian surface processes. The Wright Valley located in the ADV contains streams, lakes and ponds that host highly saline, sedimentary environments. This project highlights comparisons of formation and salt accumulation processes at the Don Juan Pond (DJP) and Don Quixote Pond (DQP). These are located in the north and south forks of the Wright Valley, which are unique areas where unusual terrestrial processes can be studied. DQP is located in the western part of the north fork about 100 m above mean seawater level. The DQP Valley walls are up to 2500 m high and the brine is seasonally frozen. DJP from the south fork is located ~9 km west of Lake Vanda. The basin floor is 117 m above mean seawater level with activity to the north and south rising above 1000 m. The DJP brine does not freeze and may be a model environment for Ca and Cl weathering and distribution on Mars. Our findings indicate that DJP and DQP have formed in similar climatic and geological environments, but likely experienced different formation conditions. Samples were collected from surface, soil pits and depth profiles during the 1979/1980, the 1990/1991 and the 2005/2006 field seasons. Elemental abundances and mineralogy were evaluated for several sets of sediments. The DJP basin shows low surface abundances of halite and relatively high abundances of sulfates throughout with gypsum or anhydrite dominating at different locations. The DQP area has high surface abundances of halite with gypsum present as the major sulfate. Two models have been proposed to explain these differences: DQP may have formed through a combination of shallow and some deep groundwater influx, while deep groundwater upwelling likely played the dominant role of salt formation at DJP. Our study seeks to understand the formation of DQP and DJP as unique terrestrial processes and as models for Ca, Cl, and S weathering and distribution on Mars.

  11. Difference fractal surfaces poured earth floors Tamaulipas / Diferencia fractal en superficies de tierra vertida con suelo de Tamaulipas

    Directory of Open Access Journals (Sweden)

    Edgardo Jonathan Suárez Dominguez

    2013-09-01

    Full Text Available Poured earth is a sustainable construction and economically feasible technique to develop in Tamaulipas, by the materials availability and traditional manufacturing procedures uses. There are several variables to be considered in these elements for their properties, among them it can be found roughness and porosity analysis which are important because they are related to material mechanical resistance and durability. This study aimed to characterize solid surfaces using fractal dimension to know its uniformity and porosity, compared with a concrete surface. Solids were obtained from poured earth of two combinations of soils stabilized with cement from the state of Tamaulipas. We found that a surface of a sample, obtained with ground, is more uniform than poured concrete surface, and that fractal dimension is higher while porosity increases; results suggest that this is because of the presence of clay in the poured earth mixtures. La tierra vertida es una técnica constructiva sustentable y económicamente viable para desarrollarse en Tamaulipas, por la disponibilidad de materiales y procedimientos de fabricación similares a los tradicionales. Son diversas las variables que deben estudiarse en estos elementos para conocer sus propiedades, entre las que se encuentran la rugosidad y la porosidad, las cuales son importantes debido a su estrecha relación con la resistencia mecánica y durabilidad del material estudiado. El presente trabajo tuvo por objetivo caracterizar superficies sólidas a partir de la dimensión fractal para conocer su uniformidad y porosidad, comparándola con una superficie de concreto. Los sólidos fueron obtenidos a partir de tierra vertida conformada de dos combinaciones de suelos estabilizadas con cemento provenientes del estado de Tamaulipas. Se encontró que una superficie de tierra vertida es menos irregular que una superficie de concreto además de tener una menor porosidad reflejada en una menor dimensión fractal

  12. Free surface BCP self-assembly process characterization with CDSEM

    Science.gov (United States)

    Levi, Shimon; Weinberg, Yakov; Adan, Ofer; Klinov, Michael; Argoud, Maxime; Claveau, Guillaume; Tiron, Raluca

    2016-03-01

    A simple and common practice to evaluate Block copolymers (BCP) self-assembly performances, is on a free surface wafer. With no guiding pattern the BCP designed to form line space pattern for example, spontaneously rearranges to form a random fingerprint type of a pattern. The nature of the rearrangement is dictated by the physical properties of the BCP moieties, wafer surface treatment and the self-assembly process parameters. Traditional CDSEM metrology algorithms are designed to measure pattern with predefined structure, like linespace or oval via holes. Measurement of pattern with expected geometry can reduce measurement uncertainty. Fingerprint type of structure explored in this dissertation, poses a challenge for CD-SEM measurement uncertainty and offers an opportunity to explore 2D metrology capabilities. To measure this fingerprints we developed a new metrology approach that combines image segmentation and edge detection to measure 2D pattern with arbitrary rearrangement. The segmentation approach enabled to quantify the quality of the BCP material and process, detecting 2D attributes such as: CD and CDU at one axis, and number of intersections, length and number of PS fragments, etched PMMA spaces and donut shapes numbers on the second axis. In this paper we propose a 2D metrology to measure arbitrary BCP pattern on a free surface wafer. We demonstrate experimental results demonstrating precision data, and characterization of PS-b-PMMA BCP, intrinsic period L0 = 38nm (Arkema), processed at different bake time and temperatures.

  13. Surface agglomeration is beneficial for release of magnetic property via research of rare earth (RE) element-substitution

    Science.gov (United States)

    Liu, Yanqing; Qi, Ji; Zhang, Yilin; Wang, Yuhan; Feng, Ming; Zhang, Junkai; Wei, Maobin; Yang, Jinghai

    2018-01-01

    BiFeO3 (BFO) thin films and Rare-Earth (RE) element substitutions were successfully fabricated on silicon substrates by sol-gel technology. Multiferroic properties of BFO had been improved considerably on RE (La, Ho, Er)-substitution at Bi site. The RE-substitution principle was presented in Fig. 1(the simulative images of ions matching). The single phase and the perovskite based rhombohedral structure with R3c space group of BFO and RE-substitution films were confirmed through the full pattern fitting of surface and section XRD profiles. There were obvious agglomeration phenomena for RE-substitution films via FESEM patterns, and the AFM images shown that the RE-substation films possessed smoother surface texture comparing with the BFO. The RE-substitution films showed higher saturation magnetization (Ms) and remanent magnetization (Mr) due to the reduced concentration of defects (oxygen vacancy), RE ions with smaller radii size (size effect) and surface structure of compactness. Fe3+ and O2- ions play an essential role in superexchange interaction, the XPS, surface and vertical EDS images revealed increasing tendency of Fe3+ ions and O2- ions.

  14. Modeling of Titan's surface processes constrained by shoreline fractal analysis and comparison with terrestrial analogs

    Science.gov (United States)

    Sharma, P.; Byrne, S.

    2011-12-01

    Lacustrine features have been observed in both the north and south polar regions of Titan, by multiple instruments onboard the NASA Cassini orbiter, including the Radio Detection and Ranging (RADAR) instrument, the Visual and Infrared Mapping Spectrometer (VIMS) and the Imaging Science Subsystem (ISS). Although the RADAR and Infrared data have provided a number of lines of evidence for these features being potential lakes, their formation mechanism is currently not well understood. Using Cassini RADAR data, we have performed a statistical analysis of the shorelines of Titan's north polar lakes and found them to be closely approximated by fractal shapes, a property also demonstrated by terrestrial lake shorelines. We calculated the fractal dimensions of the shorelines via two methods: the divider/ruler method and the box-counting method, at length scales of (1-10) km and found them to average 1.27 and 1.32, respectively. The inferred power-spectral exponent of Titan's topography (β) was found to be ≤ 2, which is lower than the values obtained from the global topography of the Earth or Venus. In order to interpret the fractal dimensions of Titan's shorelines in terms of the surficial processes at work, we repeated the same fractal analysis with terrestrial analogues using C-band radar backscatter data from the Shuttle Radar Topography Mission (SRTM). We calculated and compared statistical parameters including fractal dimension, shoreline development index and a linearity index and found different lake generation mechanisms on the Earth produce shorelines with overlapping ranges of these statistical parameters. On the basis of our statistical analyses, we concluded there is no one mechanism or set of mechanisms that can be deduced to be responsible for forming the depressions enclosing the lakes on Titan. Also, irrespective of the surface process responsible for their initial formation, these Titanian lake shorelines, like their terrestrial counterparts, could have

  15. Estimating mass-wasting processes in active earth slides – earth flows with time-series of High-Resolution DEMs from photogrammetry and airborne LiDAR

    Directory of Open Access Journals (Sweden)

    A. Corsini

    2009-03-01

    Full Text Available This paper deals with the use of time-series of High-Resolution Digital Elevation Models (HR DEMs obtained from photogrammetry and airborne LiDAR coupled with aerial photos, to analyse the magnitude of recently reactivated large scale earth slides – earth flows located in the northern Apennines of Italy. The landslides underwent complete reactivation between 2001 and 2006, causing civil protection emergencies. With the final aim to support hazard assessment and the planning of mitigation measures, high-resolution DEMs are used to identify, quantify and visualize depletion and accumulation in the slope resulting from the reactivation of the mass movements. This information allows to quantify mass wasting, i.e. the amount of landslide material that is wasted during reactivation events due to stream erosion along the slope and at its bottom, resulting in sediment discharge into the local fluvial system, and to assess the total volumetric magnitude of the events. By quantifying and visualising elevation changes at the slope scale, results are also a valuable support for the comprehension of geomorphological processes acting behind the evolution of the analysed landslides.

  16. MATLAB® and Design Recipes for Earth Sciences: How to Collect, Process and Present Geoscientific Information

    Science.gov (United States)

    Trauth, M.; Sillmann, E.

    2012-04-01

    The overall aim of the class was to introduce undergraduate students to the typical course of a project. The project starts with searching of the relevant literature, reviewing and ranking of the published books and journal articles, extracting the relevant information as text, data or graphs from the literature, searching, processing and visualizing data, and compiling and presenting the results as posters, abstracts and oral presentations. In the first lecture, an unexpectedly-large number (ca. 65) of students subscribed to the course urging us to teach the course in a lecture hall with a projector, microphone and speaker system, a table for the teacher's laptop and equipment, private laptops of the students and wireless Internet. We used a MOODLE eLearning environment to handle the large number of participants in a highly interactive, tutorial-style course environment. Moreover, the students were organized in five GOOGLE groups not accessed by the course instructor, but led by elected student group leaders and their deputies. During the course, the instructor defined three principle topics for each of the groups within the overall theme Past Climate Changes. After having defined sub-themes within the groups for each student, the course culminated in the presentation of the project work as conference-style posters, 200-word abstracts and one-hour sessions with 10-15 two-minute presentations, chaired by the project leaders and their deputies. The course inspired a new textbook that will appear later this year, using a similar concept as its sister book MATLAB Recipes for Earth Sciences-3rd Edition (Trauth, Springer 2010).

  17. Better Earth system prediction through improved representation of land processes in the Arctic: Connecting observation, experimentation, and modeling in North American Arctic tundra ecosystems

    Science.gov (United States)

    Thornton, P. E.; Painter, S. L.; Wullschleger, S. D.

    2016-12-01

    Prediction of future climate states for the Earth system depends in part on a mechanistic understanding of feedback processes operating between land ecosystems and other climate system components. Current understanding from modeling and observational studies is that Arctic land areas warm more rapidly than the globe as a whole under the influence of increased greenhouse gases. Existing Earth System Models (ESMs) capture some of the feedbacks and mechanisms thought to be responsible for this enhanced warming at high latitudes, but the high degree of spatial aggregation and coarse level of ecosystem parameterization employed in current generation ESMs make these predictions highly uncertain. Here, we review the current state of Arctic tundra representation in ESMs, and also the state of process representation in more sophisticated tundra models that are not constrained by the need for global integration. We demonstrate an approach that uses fine-scale observation and experimentation, combined with remote-sensing based characterization of surface properties at multiple spatial scales, to develop new mechanistic understanding and new parameterizations that fill knowledge and capability gaps in the current generation of ESMs. We focus our attention in this presentation on permafrost processes, the interaction of thermal, hydrologic, and biogeochemical processes with microtopography, and the representation of plant traits.

  18. On the flow magnitude and field-flow alignment at Earth's core surface

    DEFF Research Database (Denmark)

    Finlay, Chris; Amit, H.

    . An expression linking the core surface flow magnitude tospherical harmonic spectra of the MF and SV is derived from the magneticinduction equation. This involves the angle gamma between the flowand the horizontal gradient of the radial field. We study gamma in asuite of numerical dynamo models and discuss...

  19. Solar UV Irradiation-Induced Production of Greenhouse Gases from Plant Surfaces: From Leaf to Earth

    DEFF Research Database (Denmark)

    Mikkelsen, Teis Nørgaard; Bruhn, Dan; Ambus, Per

    2016-01-01

    -methane volatile organic compounds (NMVOC), NOx and N2O. This gas production, near or at the plant surface, is a new discovery and is normally not included in emission budgets (e.g. by the Intergovernmental Panel on Climate Change, IPCC) due to a lack of information with respect to validation and upscaling. For CH...

  20. Surface shift of the occupied and unoccupied 4f levels of the rare-earth metals

    DEFF Research Database (Denmark)

    Aldén, Magnus; Johansson, Börje; Skriver, Hans Lomholt

    1995-01-01

    The surface energy shifts of the occupied and unoccupied 4f levels for the lanthanide metals have been calculated from first principles by means of a Green’s-function technique within the tight-binding linear muffin-tin orbitals method. We use the concept of complete screening to identify the occ...

  1. Existence of torsional surface waves in an earth's crustal layer lying ...

    Indian Academy of Sciences (India)

    This paper aims to study the dispersion of torsional surface waves in a crustal layer being sandwiched between a rigid boundary plane and a sandy mantle. In the mantle, rigidity and initial stress vary linearly while density remains constant. Dispersion relation has been deduced in a closed form by means of variable ...

  2. Using infrared thermography for understanding and quantifying soil surface processes

    Science.gov (United States)

    de Lima, João L. M. P.

    2017-04-01

    At present, our understanding of the soil hydrologic response is restricted by measurement limitations. In the literature, there have been repeatedly calls for interdisciplinary approaches to expand our knowledge in this field and eventually overcome the limitations that are inherent to conventional measuring techniques used, for example, for tracing water at the basin, hillslope and even field or plot scales. Infrared thermography is a versatile, accurate and fast technique of monitoring surface temperature and has been used in a variety of fields, such as military surveillance, medical diagnosis, industrial processes optimisation, building inspections and agriculture. However, many applications are still to be fully explored. In surface hydrology, it has been successfully employed as a high spatial and temporal resolution non-invasive and non-destructive imaging tool to e.g. access groundwater discharges into waterbodies or quantify thermal heterogeneities of streams. It is believed that thermal infrared imagery can grasp the spatial and temporal variability of many processes at the soil surface. Thermography interprets the heat signals and can provide an attractive view for identifying both areas where water is flowing or has infiltrated more, or accumulated temporarily in depressions or macropores. Therefore, we hope to demonstrate the potential for thermal infrared imagery to indirectly make a quantitative estimation of several hydrologic processes. Applications include: e.g. mapping infiltration, microrelief and macropores; estimating flow velocities; defining sampling strategies; identifying water sources, accumulation of waters or even connectivity. Protocols for the assessment of several hydrologic processes with the help of IR thermography will be briefly explained, presenting some examples from laboratory soil flumes and field.

  3. Decontamination Efficiency of Fish Bacterial Flora from Processing Surfaces

    Directory of Open Access Journals (Sweden)

    Birna Guðbjörnsdóttir

    2009-01-01

    Full Text Available There are numerous parameters that can influence bacterial decontamination during washing of machinery and equipment in a food processing establishment. Incomplete decontamination of bacteria will increase the risk of biofilm formation and consequently increase the risk of pathogen contamination or prevalence of other undesirable microorganisms such as spoilage bacteria in the processing line. The efficiency of a typical washing protocol has been determined by testing three critical parameters and their effects on bacterial decontamination. Two surface materials (plastic and stainless steel, water temperatures (7 and 25 °C and detergent concentrations (2 and 4 % were used for this purpose in combination with two types of detergents. Biofilm was prepared on the surfaces with undefined bacterial flora obtained from minced cod fillets. The bacterial flora of the biofilm was characterised by cultivation and molecular analysis of 16S rRNA genes. All different combinations of washing protocols tested were able to remove more than 99.9 % of the bacteria in the biofilm and reduce the cell number from 7 to 0 or 2 log units of bacteria/cm2. The results show that it is possible to use less diluted detergents than recommended with comparable success, and it is easier to clean surface material made of stainless steel compared to polyethylene plastic.

  4. Elementary surface processes during reactive magnetron sputtering of chromium

    Energy Technology Data Exchange (ETDEWEB)

    Monje, Sascha; Corbella, Carles, E-mail: carles.corbella@rub.de; Keudell, Achim von [Research Group Reactive Plasmas, Ruhr-University Bochum, Universitystr. 150, 44801 Bochum (Germany)

    2015-10-07

    The elementary surface processes occurring on chromium targets exposed to reactive plasmas have been mimicked in beam experiments by using quantified fluxes of Ar ions (400–800 eV) and oxygen atoms and molecules. For this, quartz crystal microbalances were previously coated with Cr thin films by means of high-power pulsed magnetron sputtering. The measured growth and etching rates were fitted by flux balance equations, which provided sputter yields of around 0.05 for the compound phase and a sticking coefficient of O{sub 2} of 0.38 on the bare Cr surface. Further fitted parameters were the oxygen implantation efficiency and the density of oxidation sites at the surface. The increase in site density with a factor 4 at early phases of reactive sputtering is identified as a relevant mechanism of Cr oxidation. This ion-enhanced oxygen uptake can be attributed to Cr surface roughening and knock-on implantation of oxygen atoms deeper into the target. This work, besides providing fundamental data to control oxidation state of Cr targets, shows that the extended Berg's model constitutes a robust set of rate equations suitable to describe reactive magnetron sputtering of metals.

  5. Dynamics of gas-surface interactions atomic-level understanding of scattering processes at surfaces

    CERN Document Server

    Díez Muniño, Ricardo

    2013-01-01

    This book gives a representative survey of the state of the art of research on gas-surface interactions. It provides an overview of the current understanding of gas surface dynamics and, in particular, of the reactive and non-reactive processes of atoms and small molecules at surfaces. Leading scientists in the field, both from the theoretical and the experimental sides, write in this book about their most recent advances. Surface science grew as an interdisciplinary research area over the last decades, mostly because of new experimental technologies (ultra-high vacuum, for instance), as well as because of a novel paradigm, the ‘surface science’ approach. The book describes the second transformation which is now taking place pushed by the availability of powerful quantum-mechanical theoretical methods implemented numerically. In the book, experiment and theory progress hand in hand with an unprecedented degree of accuracy and control. The book presents how modern surface science targets the atomic-level u...

  6. Understanding rhizosphere processes to enhance phytoextraction of germanium and rare earth elements

    Science.gov (United States)

    Wiche, Oliver

    2017-04-01

    Germanium (Ge) and rare earth elements (REEs) are economically valuable raw materials that are not actually rare in terms of concentrations in soils but they are hardly available for plant uptake due to interactions with organic matter (SOM), secondary soil constituents such as Fe/Mn oxides and P bearing soil fractions. Processes in the rhizosphere might influence availability of Ge and REEs in the soil-plant system, since lowering of the pH and presence of carboxylates and siderophores (small molecules that strongly chelate Fe and other elements) strongly influences the chemical speciation of Ge and REEs in soil and consequently this comprehensive knowledge helps us to improve phytomining. In a series of field and greenhouse experiments 16 plant species from the functional groups of grasses, herbs and legumes were tested with regard to their accumulation efficiency of Ge and REEs in shoots. Subsequently, we conducted mixed culture experiments in which inefficient species (e.g. cereals like Avena sativa, Hordeum vulgare, Panicum miliaceum) were cultivated in mixed cultures with efficient species (Lupinus albus, Lupinus angustifolius). Based on the plant concentrations a principal component analysis (PCA) was performed to identify significant factors that explain the accumulation behavior of different plant species with regard to Ge, REEs, Si, Fe and Mn. In this analysis Mn was used to identify plant species with efficient mechanisms to access sparingly available P-resources in soils. Particularly in nonmycorrhizal species concentrations of Mn in leaves often indicate a carboxylate based P-mobilising strategy. Herbaceous plant species accumulated significantly higher amounts of REEs while grasses accumulated significantly higher amounts of Ge. Concentrations of Ge in shoots of grasses correlated significantly positive with Si, but negatively with concentrations of Mn. Indeed, the results of the PCA clearly show that plants with high Mn concentrations tend to have

  7. Earth Sciences Changed Influence on the Public Policy Process, or How Congress Stopped Communicating with Geologists

    Science.gov (United States)

    McCurdy, K. M.

    2005-12-01

    political hot potato to the scientists. The like-minded community of geologists and public servants that developed in the mid twentieth century was not happenstance, but built from the foundation of the scientific agencies and societies founded in the late nineteenth century. The policy dialect of the late twentieth century was influenced by rational choice terminology and econometric models, not mapping and resource exploration and development. Geology speaks a language increasingly incomprehensible to politicians and their constituents. Re-establishing the strong bonds to the political process is critical for the country. If constituents don't understand why earth science research is important, their elected representatives cannot be expected to vote for public funding. Without the voice of geology, the solutions forged in policy compromises for the many complex physical problems facing the country and the world will be sub-optimal.

  8. In-Situ Resource Utilization for Space Exploration: Resource Processing, Mission-Enabling Technologies, and Lessons for Sustainability on Earth and Beyond

    Science.gov (United States)

    Hepp, A. F.; Palaszewski, B. A.; Landis, G. A.; Jaworske, D. A.; Colozza, A. J.; Kulis, M. J.; Heller, R. S.

    2015-01-01

    As humanity begins to reach out into the solar system, it has become apparent that supporting a human or robotic presence in transit andor on station requires significant expendable resources including consumables (to support people), fuel, and convenient reliable power. Transporting all necessary expendables is inefficient, inconvenient, costly, and, in the final analysis, a complicating factor for mission planners and a significant source of potential failure modes. Over the past twenty-five years, beginning with the Space Exploration Initiative, researchers at the NASA Glenn Research Center (GRC), academic collaborators, and industrial partners have analyzed, researched, and developed successful solutions for the challenges posed by surviving and even thriving in the resource limited environment(s) presented by near-Earth space and non-terrestrial surface operations. In this retrospective paper, we highlight the efforts of the co-authors in resource simulation and utilization, materials processing and consumable(s) production, power systems and analysis, fuel storage and handling, propulsion systems, and mission operations. As we move forward in our quest to explore space using a resource-optimized approach, it is worthwhile to consider lessons learned relative to efficient utilization of the (comparatively) abundant natural resources and improving the sustainability (and environment) for life on Earth. We reconsider Lunar (and briefly Martian) resource utilization for potential colonization, and discuss next steps moving away from Earth.

  9. Recent Progresses in Incorporating Human Land-Water Management into Global Land Surface Models Toward Their Integration into Earth System Models

    Science.gov (United States)

    Pokhrel, Yadu N.; Hanasaki, Naota; Wada, Yoshihide; Kim, Hyungjun

    2016-01-01

    The global water cycle has been profoundly affected by human land-water management. As the changes in the water cycle on land can affect the functioning of a wide range of biophysical and biogeochemical processes of the Earth system, it is essential to represent human land-water management in Earth system models (ESMs). During the recent past, noteworthy progress has been made in large-scale modeling of human impacts on the water cycle but sufficient advancements have not yet been made in integrating the newly developed schemes into ESMs. This study reviews the progresses made in incorporating human factors in large-scale hydrological models and their integration into ESMs. The study focuses primarily on the recent advancements and existing challenges in incorporating human impacts in global land surface models (LSMs) as a way forward to the development of ESMs with humans as integral components, but a brief review of global hydrological models (GHMs) is also provided. The study begins with the general overview of human impacts on the water cycle. Then, the algorithms currently employed to represent irrigation, reservoir operation, and groundwater pumping are discussed. Next, methodological deficiencies in current modeling approaches and existing challenges are identified. Furthermore, light is shed on the sources of uncertainties associated with model parameterizations, grid resolution, and datasets used for forcing and validation. Finally, representing human land-water management in LSMs is highlighted as an important research direction toward developing integrated models using ESM frameworks for the holistic study of human-water interactions within the Earths system.

  10. Planetary gyre, time-dependent eddies, torsional waves, and equatorial jets at the Earth's core surface

    DEFF Research Database (Denmark)

    Gillet, N.; Jault, D.; Finlay, Chris

    2015-01-01

    between the magnetic field and subdecadal nonzonal motions within the fluid outer core. Both the zonal and the more energetic nonzonal interannual motions were particularly intense close to the equator (below 10∘ latitude) between 1995 and 2010. We revise down the amplitude of the decade fluctuations......We report a calculation of time-dependent quasi-geostrophic core flows for 1940–2010. Inverting recursively for an ensemble of solutions, we evaluate the main source of uncertainties, namely, the model errors arising from interactions between unresolved core surface motions and magnetic fields....... Temporal correlations of these uncertainties are accounted for. The covariance matrix for the flow coefficients is also obtained recursively from the dispersion of an ensemble of solutions. Maps of the flow at the core surface show, upon a planetary-scale gyre, time-dependent large-scale eddies...

  11. Increasing UV-B radiation at the earth's surface and potential effects on aqueous mercury cycling and toxicity.

    Science.gov (United States)

    Bonzongo, Jean Claude J; Donkor, Augustine K

    2003-09-01

    In the past two decades, a great deal of attention has been paid to the environmental fate of mercury (Hg), and this is exemplified by the growing number of international conferences devoted uniquely to Hg cycling and its impacts on ecosystem functions and life. This interest in the biogeochemistry of Hg has resulted in a significant improvement of our understanding of its impact on the environment and human health. However, both past and current research, have been primarily oriented toward the study of direct impact of anthropogenic activities on Hg cycling. Besides a few indirect effects such as the increase in Hg methylation observed in acid-rain impacted aquatic systems or the reported enhanced Hg bioaccumulation in newly flooded water reservoirs; changes in Hg transformations/fluxes that may be related to global change have received little attention. A case in point is the depletion of stratospheric ozone and the resulting increase in solar UV-radiation reaching the Earth. This review and critical discussion suggest that increasing UV-B radiation at earth's surface could have a significant and complex impact on Hg cycling including effects on Hg volatilization (photo-reduction), solubilization (photo-oxidation), methyl-Hg demethylation, and Hg methylation. Therefore, this paper is written to provoke discussions, and more importantly, to stimulate research on potential impacts of incoming solar UV-radiation on global Hg fluxes and any toxicity aspects of Hg that may become exacerbated by UV-radiation.

  12. Urbanization Process and Variation of Energy Budget of Land Surfaces

    Directory of Open Access Journals (Sweden)

    Ciro Gardi

    Full Text Available Urban areas are increasing at a rate much higher than human population growth in many part of the world; actually more than 73 towns in the world are larger than 1000 km2. The European Environmental Agency indicates an urban area average growth rate, over the last 20 years, of 20%. The urbanization process, and the consequent soil sealing, determines not only the losses of the ecological functions of the soil, but also a variation of the energy budget of land surfaces, that affect the microclimatic conditions (heat islands. The alteration of the energy budget are determined by the variations of albedo and roughness of surfaces, but especially by the net losses of evapotranspirating areas. In the present research we have assessed the variation of Parma territory energy budget, induced by the change in land use over the last 122 years. The urban area increase between 1881 and 2003 was 535%.

  13. Surface processes of dust particles in low pressure plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Stoffels, E.; Stoffels, W.W.; Kersten, H.; Swinkels, G.H.P.M.; Kroesen, G.M.W. [Technische Univ. Eindhoven (Netherlands). Dept. of Physics

    2001-07-01

    This paper presents several aspects of applied dusty plasma research. New applications of dust particles are emerging; there is growing demand for particles with special properties, and for particle-seeded composite materials. Low-pressure plasmas offer a unique possibility of confinement, control and fine tailoring of particle properties. The role of low-pressure technology in surface modification (coating) of dust grains is discussed and illustrated with examples. Fundamental research related to industrial particle treatment aims at the understanding the surface chemistry of processing. More specifically, the nature of plasma-particle interactions must be resolved. Heat exchange and particle temperature, discussed in this paper, are of major interest in the applied dusty plasma studies. (orig.)

  14. Community Earth System Model Simulations Reveal the Relative Importance of Afforestation and Forest Management to Surface Temperature in Eastern North America

    Directory of Open Access Journals (Sweden)

    Benjamin J. Ahlswede

    2017-12-01

    Full Text Available Afforestation changes the land surface energy balance, though the effects on climate in temperate regions is uncertain, particularly the changes associated with forest management. In this study, we used idealized Community Earth System Model simulations to assess the influence of afforestation and afforestation management in eastern North America on climate via changes in the biophysics of the land surface. Afforestation using broadleaf deciduous trees maintained at high leaf area index (LAI in the southern part of the study region provided the greatest climate benefit by cooling summer surface air temperatures (Tsa. In contrast, the greatest warming occurred in the northern extent of the study region when afforesting with needleleaf evergreen trees maintained at high LAI. Forest management had an equal or greater influence on Tsa than the overall decision to afforest land in the southern extent of the region. Afforestation had a greater influence on Tsa than forest management in the northern extent. Integrating our results, focused on biophysical processes, with other research quantifying carbon cycle sensitivity to management can help guide the use of temperate afforestation to optimize climate benefits. Further, our results highlight the potential importance of including forest management in simulations of past and future climate.

  15. Titan's Surface Diversity and Ongoing Processes-A Review

    Science.gov (United States)

    Soderblom, Laurence A.

    2012-04-01

    Titan’s landscapes exhibit a wealth of surface diversity that rivals the glossary for a textbook on Earth’s geomorphological styles and geological processes. Long before Cassini-Huygens’ arrival, evidence suggested that Titan’s surface might harbor liquid hydrocarbons, methane and ethane, in the form of lakes, seas, or even oceans. And, as the surface gradually became visible to the Huygens Probe on its slow descent, it became clear that liquids had been quite active in sculpting and dissecting the terrains: a network of dendritic channels densely drapes the highlands located a few kilometers north of the landing site. This led Tomasko and colleagues to lead off the title of their Huygens report with “Rain, winds and haze …” And not only were winds responsible for the Probe’s erratic change in direction as it neared the surface but soon we discovered that they also drive vast seas of longitudinal dunes eastward, wrapping the equatorial zone. Current thinking is that the dunes consist of coarse grains of solid hydrocarbons, perhaps mixed with water ice, that saltate in the slow-moving dense atmosphere. And, although we did not find vast methane-ethane oceans, we did find polar lakes and seas, vast in the north and sparse in the south. Elsewhere impact, tectonic, and, more arguably, volcanic features appear to be ubiquitous. The subjects of Titan’s geology continue to cascade into a host of new details of the subjects of process and geomorphology; the collection terms, familiar to terrestrial science, continues to grow. References: Tomasko, M. G., et al. (2005) “Rain, winds and haze during the Huygens probe’s descent to Titan’s surface”. Nature, Vol. 438, pp.775-778.

  16. Sensitivities of Earth's core and mantle compositions to accretion and differentiation processes

    Science.gov (United States)

    Fischer, Rebecca A.; Campbell, Andrew J.; Ciesla, Fred J.

    2017-01-01

    The Earth and other terrestrial planets formed through the accretion of smaller bodies, with their core and mantle compositions primarily set by metal-silicate interactions during accretion. The conditions of these interactions are poorly understood, but could provide insight into the mechanisms of planetary core formation and the composition of Earth's core. Here we present modeling of Earth's core formation, combining results of 100 N-body accretion simulations with high pressure-temperature metal-silicate partitioning experiments. We explored how various aspects of accretion and core formation influence the resulting core and mantle chemistry: depth of equilibration, amounts of metal and silicate that equilibrate, initial distribution of oxidation states in the disk, temperature distribution in the planet, and target:impactor ratio of equilibrating silicate. Virtually all sets of model parameters that are able to reproduce the Earth's mantle composition result in at least several weight percent of both silicon and oxygen in the core, with more silicon than oxygen. This implies that the core's light element budget may be dominated by these elements, and is consistent with ≤1-2 wt% of other light elements. Reproducing geochemical and geophysical constraints requires that Earth formed from reduced materials that equilibrated at temperatures near or slightly above the mantle liquidus during accretion. The results indicate a strong tradeoff between the compositional effects of the depth of equilibration and the amounts of metal and silicate that equilibrate, so these aspects should be targeted in future studies aiming to better understand core formation conditions. Over the range of allowed parameter space, core and mantle compositions are most sensitive to these factors as well as stochastic variations in what the planet accreted as a function of time, so tighter constraints on these parameters will lead to an improved understanding of Earth's core composition.

  17. Prediction of types of pyroxenes on the surface of bright near-earth and near-Mars asteroids

    Science.gov (United States)

    Shestopalov, D. I.; Golubeva, L. F.

    1992-04-01

    Colorimetric data of bright near-earth and near-Mars asteroids from TRIAD and ECAS are analyzed. Composition fields of pyroxenes were obtained for these asteroids from the value of the u-x color index and the ferrous absorption band position near 505 nm within the pyroxene quadrilateral. Pyroxenes of the S asteroids from the Apollo-Amur group which have spectral parameters similar to achondrites may be represented by the diopside-augite series. AA asteroids (S type), whose spectral parameters are similar to L-chondrites, have either a chondritic composition or Fe-rich orthopyroxenes and clinopyroxenes that are not encountered in meteoritic minerals. It is found that the average u-x color index increases with increasing average perihelion distance from 1 to 1.8 AU, which indicates the dependence of the chemical composition of pyroxenes on the surface of bright asteroids on this distance.

  18. Venus: The Atmosphere, Climate, Surface, Interior and Near-Space Environment of an Earth-Like Planet

    Science.gov (United States)

    Taylor, Fredric W.; Svedhem, Håkan; Head, James W.

    2018-02-01

    This is a review of current knowledge about Earth's nearest planetary neighbour and near twin, Venus. Such knowledge has recently been extended by the European Venus Express and the Japanese Akatsuki spacecraft in orbit around the planet; these missions and their achievements are concisely described in the first part of the review, along with a summary of previous Venus observations. The scientific discussions which follow are divided into three main sections: on the surface and interior; the atmosphere and climate; and the thermosphere, exosphere and magnetosphere. These reports are intended to provide an overview for the general reader, and also an introduction to the more detailed topical surveys in the following articles in this issue, where full references to original material may be found.

  19. An analysis of the moon's surface using reflected illumination from the earth during a waning crescent lunar phase

    Science.gov (United States)

    Hammond, Ernest C., Jr.; Linton-Petza, Maggie

    1989-01-01

    There have been many articles written concerning the lunar after-glow, the spectacular reflection from the moon's surface, and the possible observation of luminescence on the dark side of the moon. The researcher, using a 600 mm cassegrain telescope lense and Kodak 400 ASA T-Max film, photographed the crescent moon whose dark side was clearly visible by the reflected light from earth. The film was digitized to a Perkin-Elmer 1010M microdensitometer for enhancement and enlargement. The resulting pictures indicate a completely different land pattern formation than observed during a full moon. An attempt is made to analyze the observed structures and to compare them to the pictures observed during the normal full moon. There are boundaries on the digitized dark section of the moon that can be identified with structures seen during the normal full moon. But, these variations do change considerably under enhancement.

  20. Habitat of early life: Solar X-ray and UV radiation at Earth's surface 4-3.5 billion years ago

    OpenAIRE

    Cnossen, I.; Sanz-Forcada, J.; Favata, F.; Witasse, O.; Zegers, T.; Arnold, N. F.

    2007-01-01

    Solar X-ray and UV radiation (0.1-320 nm) received at Earth's surface is an important aspect of the circumstances under which life formed on Earth. The quantity that is received depends on two main variables: the emission of radiation by the young Sun and its extinction through absorption and scattering by the Earth's early atmosphere. The spectrum emitted by the Sun when life formed, between 4 and 3.5 Ga, was modeled here, including the effects of flares and activity cycles, using a solar-li...

  1. Optical characteristics of the earth's surface and atmosphere from the point of view of the remote sensing of natural resources: Review of the contemporary status of the problem

    Science.gov (United States)

    Tarnopolskiy, V. I.

    1978-01-01

    Widely used remote probing methods, and especially the multispectral method, for studying the earth from aerospace platforms necessitate the systematization and accumulation of data on the relationships between remote observations and measured parameters and characteristic properties and conditions of phenomena on the earth's surface. Data were presented on the optical characteristics of natural objects which arise during observations of these objects over a wide spectral interval which encompasses solar radiation reflected by the object as well as the object's inherent thermal radiation. The influence of the earth's atmosphere on remote measurements and several problems in simulation and calculation are discussed.

  2. Interdependencies of Arctic land surface processes: A uniquely sensitive environment

    Science.gov (United States)

    Bowling, L. C.

    2007-12-01

    The circumpolar arctic drainage basin is composed of several distinct ecoregions including steppe grassland and cropland, boreal forest and tundra. Land surface hydrology throughout this diverse region shares several unique features such as dramatic seasonal runoff differences controlled by snowmelt and ice break-up; the storage of significant portions of annual precipitation as snow and in lakes and wetlands; and the effects of ephemeral and permanently frozen soils. These arctic land processes are delicately balanced with the climate and are therefore important indicators of change. The litany of recently-detected changes in the Arctic includes changes in snow precipitation, trends and seasonal shifts in river discharge, increases and decreases in the extent of surface water, and warming soil temperatures. Although not unique to the arctic, increasing anthropogenic pressures represent an additional element of change in the form of resource extraction, fire threat and reservoir construction. The interdependence of the physical, biological and social systems mean that changes in primary indicators have large implications for land cover, animal populations and the regional carbon balance, all of which have the potential to feed back and induce further change. In fact, the complex relationships between the hydrological processes that make the Artic unique also render observed historical change difficult to interpret and predict, leading to conflicting explanations. For example, a decrease in snow accumulation may provide less insulation to the underlying soil resulting in greater frost development and increased spring runoff. Similarly, melting permafrost and ground ice may lead to ground subsidence and increased surface saturation and methane production, while more complete thaw may enhance drainage and result in drier soil conditions. The threshold nature of phase change around the freezing point makes the system especially sensitive to change. In addition, spatial

  3. Surface photo reaction processes using synchrotron radiation; Hoshako reiki ni yoru hyomenko hanno process

    Energy Technology Data Exchange (ETDEWEB)

    Imaizumi, Y. [Tohoku University, Sendai (Japan). Institute for Materials Research; Yoshigoe, A. [Toyohashi University of Technology, Aichi (Japan); Urisu, T. [Toyohashi University of Technology, Aichi (Japan). Institute for Molecular Science

    1997-08-20

    This paper introduces the surface photo reaction processes using synchrotron radiation, and its application. A synchrotron radiation process using soft X-rays contained in electron synchrotron radiated light as an excited light source has a possibility of high-resolution processing because of its short wave length. The radiated light can excite efficiently the electronic state of a substance, and can induce a variety of photochemical reactions. In addition, it can excite inner shell electrons efficiently. In the aspect of its application, it has been found that, if radiated light is irradiated on surfaces of solids under fluorine-based reaction gas or Cl2, the surfaces can be etched. This technology is utilized practically. With regard to radiated light excited CVD process, it may be said that anything that can be deposited by the ordinary plasma CVD process can be deposited. Its application to epitaxial crystal growth may be said a nano processing application in thickness direction, such as forming an ultra-lattice structure, the application being subjected to expectation. In micromachine fabricating technologies, a possibility is searched on application of a photo reaction process of the radiated light. 5 refs., 6 figs.

  4. Modeling and Zoning Solar Energy Received at the Earth's Surface in Arid and Semiarid Regions of Central Iran

    Directory of Open Access Journals (Sweden)

    azam gholamnia

    2017-02-01

    Full Text Available Introduction: Solar radiation (Rs energy received at the Earth's surface is measured usingclimatological variables in horizontal surface and is widely used in various fields. Domination of hot and dry climates especially in the central regions of Iran results from decreasing cloudiness and precipitation and increasing sunshine hours, which shows the high potential of solar energy in Iran. There is a reasonable climatic field and solar radiation in most of regions and seasons which have provided an essential and suitable field to use and extend new and pure energy. Materials and Methods: One of the common methods to estimate the solar energy received by the earthis usingtemperature variables in any place . An empirical model is proposed to estimate the solar energy as a function of other climatic variables (maximum temperature recorded in 50 climatological, conventional stations; this model is helpful inextending the climatological solar-energy estimation in the study area. The mean values of both measured and estimated solar energy wereobjectively mapped to fill the observation gaps and reduce the noise associated with inhomogeneous statistics and estimation errors. This analysis and the solar irradiation estimation method wereapplied to 50 different climatologicalstations in Iran for monthly data during1980–2005. The main aim of this study wasto map and estimate the solar energy received in four provinces of Yazd, Esfahan, Kerman and Khorasan-e-Jonoubi.The data used in this analysis and its processing, as well as the formulation of an empirical model to estimate the climatological incident of solar energy as a function of other climatic variables, which is complemented with an objective mapping to obtain continuous solar-energy maps. Therefore, firstly the Rswasestimated using a valid model for 50 meteorological stations in which the amounts of solar radiation weren't recorded for arid and semi-arid areas in Iran. Then, the appropriate method

  5. Howardite Noble Gases as Indicators of Asteroid Surface Processing

    Science.gov (United States)

    Cartwright, J. A.; Mittlefehldt, D. W.; Herrin, J. S.; Ott, U.

    2011-01-01

    The HED (Howardite, Eucrite and Diogenite) group meteorites likely or iginate from the Asteroid 4 Vesta - one of two asteroid targets of NA SA's Dawn mission. Whilst Howardites are polymict breccias of eucriti c and diogenitic material that often contain "regolithic" petrologica l features, neither their exact regolithic nature nor their formation processes are well defined. As the Solar Wind (SW) noble gas compon ent is implanted onto surfaces of solar system bodies, noble gas anal yses of Howardites provides a key indicator of regolithic origin. In addition to SW, previous work by suggested that restricted Ni (300-12 00 micro g/g) and Al2O3 (8-9 wt%) contents may indicate an ancient we ll-mixed regolith. Our research combines petrological, compositional and noble gas analyses to help improve understanding of asteroid reg olith formation processes, which will play an intergral part in the i nterpretation of Dawn mission data. Following compositional and petrological analyses, we developed a regolith grading scheme for our sampl e set of 30 Howardites and polymict Eucrites. In order to test the r egolith indicators suggested by, our 8 selected samples exhibited a r ange of Ni, Al2O3 contents and regolithic grades. Noble gas analyses were performed using furnace stepheating on our MAP 215-50 noble gas mass spectrometer. Of our 8 howardites, only 3 showed evidence of SW noble gases (e.g approaching Ne-20/Ne-22 approximately equals 13.75, Ne-21/Ne-22 approximately equals 0.033). As these samples display low regolithic grades and a range of Ni and Al2O3 contents, so far we are unable to find any correlation between these indicators and "regolit hic" origin. These results have a number of implications for both Ho wardite and Vesta formation, and may suggest complex surface stratigr aphies and surface-gardening processes.

  6. Equilibrium and kinetic Si isotope fractionation factors and their implications on Si isotope distributions in the Earth's surface environments

    Science.gov (United States)

    Tang, M.; Zhang, S.; Liu, Y.

    2015-12-01

    Several important equilibrium Si isotope fractionation factors among minerals, organic molecules and the H4SiO4 solution are complemented to facilitate explanation of distributions of Si isotope in the Earth's surface environments. The results reveal that heavy Si isotopes will be significantly enriched in the secondary silicate minerals in comparison to aqueous H4SiO4. On the contrary, quadra-coordinated organosilicon complexes are enriched in light silicon isotope relative to the solution. The extent of 28Si-enrichment in hyper-coordinated organosilicon complexes is found the largest. In addition, the large kinetic isotope effect associated with the polymerization of monosilicic acid and dimer is calculated and the result supports previous statement that highly 28Si-enrichment in the formation of amorphous quartz precursor contributes to the discrepancy between theoretical calculations and field observations. With equilibrium Si isotope fractionation factors provided here, Si isotope distributions in many surface systems of the Earth can be explained. For example, the change of bulk soil δ30Si can be predicted as a concave pattern with respect to weathering degree, with the minimum value where allophane completely dissolves and the total amount of sesqui-oxides and poorly crystalline minerals reaches its maximum. When well-crystallized clays start to precipitate from pore solutions under equilibrium conditions, the bulk soil δ30Si will increase again and reach a constant value. Similarly, the precipitation of crystalline smectite and the dissolution of poorly crystalline kaolinite may explain δ30Si variations in the ground water profile. Equilibrium Si isotope fractionations among quadra-coordinated organosilicon complexes and the H4SiO4 solution may also shed the light on the Si isotope distributions in Si-accumulating plants.

  7. Process of forming catalytic surfaces for wet oxidation reactions

    Science.gov (United States)

    Jagow, R. B. (Inventor)

    1977-01-01

    A wet oxidation process was developed for oxidizing waste materials, comprising dissolved ruthenium salt in a reactant feed stream containing the waste materials. The feed stream is introduced into a reactor, and the reactor contents are then raised to an elevated temperature to effect deposition of a catalytic surface of ruthenium black on the interior walls of the reactor. The feed stream is then maintained in the reactor for a period of time sufficient to effect at least partial oxidation of the waste materials.

  8. Land surface process and radiobrightness modeling of the Great Plains

    Science.gov (United States)

    Judge, Jasmeet

    Accurate estimation of stored water by Land Surface Process (LSP) models is crucial to the prediction of continental weather and near-term climate by General Circulation Models (GCMs). This dissertation represents an important step toward assimilating the satellite radiometric observations to improve the soil moisture estimates. It consists of "forward" modeling of terrain brightnesses through a biophysically-based Land Surface Process/Radiobrightness (LSP/R) model, and correlating ground-based brightnesses with those from the Special Sensor Microwave/Imager (SSM/I). The LSP/R model was modified and calibrated for representative terrain in the Great Plains during summertime, when the surface processes are dominant and strongly coupled. The calibration used data from two collaborative field investigations, the fourth and the fifth Radiobrightness Energy Balance Experiments (REBEX-4 and REBEX-5). REBEX-4 was a collaboration with the Atmospheric Environment Service (AES), Canada, at the USGS EROS Data Center near Sioux Falls, SD. During the experiment, we observed microwave emission and concurrent micro-meteorological parameters at a bare soil and a nearby grass site from June-September in 1996. REBEX-5 was the University of Michigan's contribution to an extensive field investigation, Southern Great Plains Hydrology Experiment (SGP'97), conducted in north central Oklahoma from June 18--July 17 in 1997. During REBEX-5, we measured brightnesses of senescent winter wheat and after harvest wheat-stubble. In general, the calibrated LSP model predicted realistic surface processes that compared well with the field observations. The model predictions were most sensitive to shortwave albedo of the terrain and soil thermal and hydraulic conductivities. The Radiobrightness module captured the mean diurnal variations in brightnesses. The H-pol terrain brightnesses at 19 GHz were more sensitive to soil moisture and roughness than the V-pol brightnesses. The comparison of the EASE

  9. Processes of India's offshore summer intraseasonal sea surface temperature variability

    Digital Repository Service at National Institute of Oceanography (India)

    Kurian, N.; Lengaigne, M.; Gopalakrishna, V.V.; Vialard, J.; Pous, S.; Peter, A-C.; Durand, F.; Naik, Shweta

    . LOCEAN, IRD/CNRS/UPMC/MNHN, Paris, France 3. LEGOS, IRD/CNRS/CNES/UPS, Toulouse, France Corresponding author address: Nisha Kurian Physical Oceanography Division, National Institute of Oceanography, Dona Paula. Goa India – 403004; E...., vol.63; 2013; 329-346 Processes of India’s offshore summer intraseasonal sea surface temperature variability K. Nisha1, M. Lengaigne1,2, V.V. Gopalakrishna,1 J. Vialard2, S. Pous2, A.-C. Peter2, F. Durand3, S.Naik1 1. NIO, CSIR, Goa, India 2...

  10. On-board Payload Data Processing from Earth to Space Segment

    Science.gov (United States)

    Tragni, M.; Abbattista, C.; Amoruso, L.; Cinquepalmi, L.; Bgongiari, F.; Errico, W.

    2013-09-01

    environment with encapsulated low-level drivers, HW support and testing environment). Furthermore Space PDP presents an advanced processing system to be fully adopted both as on-board module for EO spacecrafts and extra-planetary exploration rovers. The main innovative aspects are: • HW and SW modularity - scalability for the Payload Data Processing and AOC S/S • Complex processing capabilities fully available onboard (on spacecrafts or rovers) • Reduced effort in mission SW design, implementation, verification and validation tasks • HW abstraction level comparable to present multitasking Unix-like systems allowing SW and algorithms re-use (also from available GS applications). The development approach addressed by SpacePDP is based both on the re-use and resources sharing with flexible elements adjustable to different missions and to different tasks within the same mission (e.g. shared between AOCS and data management S/S) and on a strong specialization in the system elements that are designed to satisfy specific mission needs and specific technological innovations. The innovative processing system is proven in many possible scenarios of use from standard compression task up to the most complex one as the image classification directly on-board. The first one is just useful for standard benchmark trade-off analysis of HW and SW capabilities respect to the other common processing modules. The classification is the ambitious objective of that system to process directly on board the data from sensor (by down-sampling or in no-full resolution acquisition modality if necessary) to detect at flight time any features on ground or observed phenomenas. For Earth application it could be the cloud coverage (to avoid the acquisition and discard the data), burning areas or vessels detection and similar. On Planetary o Universe exploration mission it could be the path recognition for a rover, or high power energy events in outbound galaxies. Sometimes it could be need to review the

  11. RARE EARTH ELEMENTS: A REVIEW OF PRODUCTION, PROCESSING, RECYCLING, AND ASSOCIATED ENVIRONMENTAL ISSUES

    Science.gov (United States)

    Rare earth elements (REEs) are a group of 15 chemical elements in the periodic table, specifically the lanthanides. Two other elements, scandium and yttrium, have a similar physiochemistry to the lanthanides, are commonly found in the same mineral assemblages, and are often refe...

  12. Land use and surface process domains on alpine hillslopes

    Science.gov (United States)

    Kuhn, Nikolaus J.; Caviezel, Chatrina; Hunziker, Matthias

    2015-04-01

    Shrubs and trees are generally considered to protect hillslopes from erosion. As a consequence, shrub encroachment on mountain pastures after abandoning grazing is not considered a threat to soils. However, the abandonment of mown or grazed grasslands causes a shift in vegetation composition and thus a change in landscape ecology and geomorphology. On many alpine slopes, current changes in land use and vegetation cover are accompanied by climate change, potentially generating a new geomorphic regime. Most of the debate focuses on the effect of land abandonment on water erosion rates. Generally, an established perennial vegetation cover improves the mechanical anchoring of the soil and the regulation of the soil water budget, including runoff generation and erosion. However, changing vegetation composition affects many other above- and below-ground properties like root density, -diversity and -geometry, soil structure, pore volume and acidity. Each combination of these properties can lead to a distinct scenario of dominating surface processes, often not reflected by common erosion risk assessment procedures. The study of soil properties along a chronosequence of green alder (alnusviridis) encroachment on the Unteralptal in central Switzerland reveals that shrub encroachment changes soil and vegetation properties towards an increase of resistance to run-off related erosion processes, but a decrease of slope stability against shallow landslides. The latter are a particular threat because of the currently increasing frequency of slide-triggering high magnitude rainfalls. The potential change of process domain on alpine pastures highlights the need for a careful use of erosion models when assessing future land use and climate scenarios. In mountains, but also other intensively managed agricultural landscapes, risk assessment without the appropriate reflection on the shifting relevance of surface processes carries the risk of missing future threats to environmental

  13. Surfaces: processing, coating, decontamination, pollution, etc. Surface mastering to prevent component corrosion; Surfaces: traitement, revetements, decontamination, pollution, etc. Maitrise de la surface pour prevenir la corrosion des composants

    Energy Technology Data Exchange (ETDEWEB)

    Foucault, M. [Departement Corrosion Chimie, AREVA Centre Technique, BP 181, 71205 Le Creusot (France)

    2012-07-01

    In the primary and secondary circuits of nuclear Pressurized Water Reactors, AREVA uses several nickel-based alloys or austenitic stainless steels for the manufacture of safety components. The experience feedback of the last twenty years allows us to point out the major role hold by the component surface state in their life duration. In this paper, we present four examples of problem encountered and solved by a surface study and the definition and implementation of processes for the surface control of the repaired components. Then, we propose some ideas about the present needs in term of analysis means to improve the surface knowledge and control of the manufactured components. (author)

  14. Proximal surface caries detection with direct-exposure and rare earth screen/film imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lundeen, R.C.; McDavid, W.D.; Barnwell, G.M.

    1988-12-01

    This laboratory study compared five imaging systems for their diagnostic accuracy in detection of proximal surface dental caries. Ten viewers provided data on radiographic detectability of carious lesions. The diagnostic accuracy of each system was determined with receiver operating characteristic (ROC) curves by comparing viewer data with the true state of the teeth as determined microscopically. D-speed film marginally outperformed the other four systems, but the three screen/film systems matched the diagnostic accuracy of E-speed film. Radiation reductions between 62% and 92% were achieved with the screen/film systems when compared to the two conventional dental films. The feasibility of designing a screen/film bite-wing cassette was shown, but the poor diagnostic accuracy of the present bite-wing system indicated a need for a new technology in caries detection.

  15. Tectonics, Uplift and Surface Processes in the Moroccan Atlas Mountains

    Science.gov (United States)

    Teixell, A.; Arboleya, M.; Babault, J.; Teson, E.; Ayarza, P.; Alvarez-Lobato, F.; Owen, L. A.

    2008-12-01

    The Atlas Mountains of Morocco constitute a natural laboratory for studying interactions between tectonics and surface processes in convergent zones. The tectonic forcing of the system is well understood, where a combination of crustal and mantle processes contributed to surface uplift. A growing database on magnetostratigraphic dating of synorogenic sediments, low-temperature thermochronology and surface exposure dating constrain the relationships between tectonics, erosion, climate and drainage patterns during the late Cenozoic. The Atlas chains derive from the Cenozoic inversion of Triassic-Jurassic rifts in the NW African plate. Topography is high: large areas lie over 2000 m of mean elevation, and summits exceed 4000 m. In spite of high elevation, crustal thickening is modest: tectonic shortening is mean rate of 0.2 mm/a. Moderate erosion in the Atlas prevents to detect Cenozoic apatite fission-track ages except from narrow areas, where ages of 17-25 Ma record exhumation induced by the crustal shortening mechanism. The southern, best preserved foreland basin system of the Atlas Mountains was internally drained until the late Miocene-early Pliocene. The system was then captured or overflowed across mountain massifs that bordered it to the S (Anti-Atlas). External drainage resulted in fluvial incision strongly modulated by climate change on glacial-interglacial timescales, as evidenced by cosmogenic dating of fans and terraces. Incision occurred at rates of 0.3-1 mm/a for the later part of the Quaternary, demonstrating a strong climatic control on sediment transfer and landscape denudation during this epoch.

  16. Dynamics of the accumulation process of the Earth group of planets: Formation of the reverse rotation of Venus

    Science.gov (United States)

    Koslov, N. N.; Eneyev, T. M.

    1979-01-01

    A numerical simulation of the process of formation of the terrestrial planets is carried within the framework of a new theory for the accumulation of planetary and satellite systems. The numerical simulation permitted determining the parameters of the protoplanetary disk from which Mercury, Venus and the Earth were formed as result of the evolution. The acquisition of a slow retrograde rotation for Venus was discovered during the course of the investigation, whereas Mercury and the Earth acquired direct rotation about their axes. Deviations of the semimajor axes of these three planets as well as the masses of the Earth and Venus from the true values are small as a rule (l 10%). It is shown that during the accumulation of the terrestrial planets, there existed a profound relationship between the process of formation of the orbits and masses of the planet and the process of formation of their rotation about their axes. Estimates are presented for the radii of the initial effective bodies and the time of evolution for the terrestrial accumulation zone.

  17. Mesozoic-Cenozoic course of temperatures on the earth's surface and geothermal regime of the Jurassic oil source deposits (southern paleoclimatic zone of West Siberia)

    OpenAIRE

    Isaev, V.I.; Iskorkina, A. A.

    2017-01-01

    In a review the state of studies of the influence of the secular course of temperatures on the earth's surface on the thermal history of deep oil source deposits is characterized as a state of scientific research. The aim of research is generalization of the known data about Mesozoic-Cenozoic climate of southeastern part of West Siberia and the assessment of impact of the secular course of temperature of the earth's surface on the geothermal regime, the degree of realization of generation pot...

  18. MarsSI: Martian surface data processing information system

    Science.gov (United States)

    Quantin-Nataf, C.; Lozac'h, L.; Thollot, P.; Loizeau, D.; Bultel, B.; Fernando, J.; Allemand, P.; Dubuffet, F.; Poulet, F.; Ody, A.; Clenet, H.; Leyrat, C.; Harrisson, S.

    2018-01-01

    MarsSI (Acronym for Mars System of Information, https://emars.univ-lyon1.fr/MarsSI/, is a web Geographic Information System application which helps managing and processing martian orbital data. The MarsSI facility is part of the web portal called PSUP (Planetary SUrface Portal) developed by the Observatories of Paris Sud (OSUPS) and Lyon (OSUL) to provide users with efficient and easy access to data products dedicated to the martian surface. The portal proposes 1) the management and processing of data thanks to MarsSI and 2) the visualization and merging of high level (imagery, spectral, and topographic) products and catalogs via a web-based user interface (MarsVisu). The portal PSUP as well as the facility MarsVisu is detailed in a companion paper (Poulet et al., 2018). The purpose of this paper is to describe the facility MarsSI. From this application, users are able to easily and rapidly select observations, process raw data via automatic pipelines, and get back final products which can be visualized under Geographic Information Systems. Moreover, MarsSI also contains an automatic stereo-restitution pipeline in order to produce Digital Terrain Models (DTM) on demand from HiRISE (High Resolution Imaging Science Experiment) or CTX (Context Camera) pair-images. This application is funded by the European Union's Seventh Framework Programme (FP7/2007-2013) (ERC project eMars, No. 280168) and has been developed in the scope of Mars, but the design is applicable to any other planetary body of the solar system.

  19. The role of land surface dynamics in glacial inception: a study with the UVic Earth System Model

    Energy Technology Data Exchange (ETDEWEB)

    Meissner, K.J.; Weaver, A.J.; Matthews, H.D. [School of Earth and Ocean Sciences, University of Victoria, Victoria (Canada); Cox, P.M. [Hadley Centre, Meteorological Office, Bracknell (United Kingdom)

    2003-12-01

    The first results of the UVic Earth System Model coupled to a land surface scheme and a dynamic global vegetation model are presented in this study. In the first part the present day climate simulation is discussed and compared to observations. We then compare a simulation of an ice age inception (forced with 116 ka BP orbital parameters and an atmospheric CO{sub 2} concentration of 240 ppm) with a preindustrial run (present day orbital parameters, atmospheric [CO{sub 2}] = 280 ppm). Emphasis is placed on the vegetation's response to the combined changes in solar radiation and atmospheric CO{sub 2} level. A southward shift of the northern treeline as well as a global decrease in vegetation carbon is observed in the ice age inception run. In tropical regions, up to 88% of broadleaf trees are replaced by shrubs and C{sub 4} grasses. These changes in vegetation cover have a remarkable effect on the global climate: land related feedbacks double the atmospheric cooling during the ice age inception as well as the reduction of the meridional overturning in the North Atlantic. The introduction of vegetation related feedbacks also increases the surface area with perennial snow significantly. (orig.)

  20. QuakeSim: a Web Service Environment for Productive Investigations with Earth Surface Sensor Data

    Science.gov (United States)

    Parker, J. W.; Donnellan, A.; Granat, R. A.; Lyzenga, G. A.; Glasscoe, M. T.; McLeod, D.; Al-Ghanmi, R.; Pierce, M.; Fox, G.; Grant Ludwig, L.; Rundle, J. B.

    2011-12-01

    The QuakeSim science gateway environment includes a visually rich portal interface, web service access to data and data processing operations, and the QuakeTables ontology-based database of fault models and sensor data. The integrated tools and services are designed to assist investigators by covering the entire earthquake cycle of strain accumulation and release. The Web interface now includes Drupal-based access to diverse and changing content, with new ability to access data and data processing directly from the public page, as well as the traditional project management areas that require password access. The system is designed to make initial browsing of fault models and deformation data particularly engaging for new users. Popular data and data processing include GPS time series with data mining techniques to find anomalies in time and space, experimental forecasting methods based on catalogue seismicity, faulted deformation models (both half-space and finite element), and model-based inversion of sensor data. The fault models include the CGS and UCERF 2.0 faults of California and are easily augmented with self-consistent fault models from other regions. The QuakeTables deformation data include the comprehensive set of UAVSAR interferograms as well as a growing collection of satellite InSAR data.. Fault interaction simulations are also being incorporated in the web environment based on Virtual California. A sample usage scenario is presented which follows an investigation of UAVSAR data from viewing as an overlay in Google Maps, to selection of an area of interest via a polygon tool, to fast extraction of the relevant correlation and phase information from large data files, to a model inversion of fault slip followed by calculation and display of a synthetic model interferogram.

  1. Geomagnetic jerks from the Earth's surface to the top of the core

    Science.gov (United States)

    Chambodut, Aude; Eymin, Céline; Mandea, Mioara

    2007-07-01

    Rapid changes in the magnetic field characterised by an abrupt change in the secular variation have been named "secular variation impulses" or "geomagnetic jerks". Three of these events, around 1968, 1978 and 1990, occurred during the time-span covered by the comprehensive model CM4 (Sabaka et al., 2002, 2004). This model, providing the best temporal resolution between 1960 and 2002 as well as a fine separation of the different magnetic sources, can be used to study rapid phenomena of internal origin. In order to analyse these events all over the globe, synthetic time series were obtained from the CM4 model between 1960-2002. Geomagnetic jerks are detected here as a rapid movement of the zero isoline of the second field derivative. Analysis of the area swept out by this isoline as a function of time allows us to map the spatial extent of jerks though time, and to identify an event around 1985 that is localized in the Pacific area. At the core surface, we compute the fluid flows under the frozen-flux and tangentially geostrophic assumptions. The flows do not exhibit any special pattern at jerk times, but instead show a smooth temporal evolution over the whole time period. However, the mean amplitude of the dynamical pressure associated with these flows present maxima at each jerk occurrence and helps to confirm the identification of a jerk in 1985.

  2. Investigation of the effect of contaminations and cleaning processes on the surface properties of brazing surfaces

    Science.gov (United States)

    Bobzin, K.; Öte, M.; Wiesner, S.

    2017-03-01

    The quality of brazed joints is determined by different factors such as the atmosphere and the parameters during brazing as well as the condition of the brazing surfaces. Residues of lubricants used during machining of the components and the subsequent cleaning processes can contaminate the faying surfaces and can hence influence the flow ability of the molten filler metals. Besides their influence on the filler metal flow, the residues can result in the formation of carbonic phases in the joint leading to a possible reduction of the corrosion resistance and the mechanical properties. The first step of the current study with the aim of avoiding these defects is to identify the influence of critical contaminations and cleaning methods on the quality of the brazed joints. In a first step, contaminations on AISI304 and Inconel alloy 625 due to different cooling lubricants and the effect of several cleaning methods, in particular plasma cleaning, have been investigated. Information about the surface energy of contaminated and cleaned surfaces was gained by measuring contact angle of testing fluids. Additionally, the lubricants and the resulting contamination products have been analyzed considering the influence of a heat treatment.

  3. Rare-earth-doped materials with application to optical signal processing, quantum information science, and medical imaging technology

    Science.gov (United States)

    Cone, R. L.; Thiel, C. W.; Sun, Y.; Böttger, Thomas; Macfarlane, R. M.

    2012-02-01

    Unique spectroscopic properties of isolated rare earth ions in solids offer optical linewidths rivaling those of trapped single atoms and enable a variety of recent applications. We design rare-earth-doped crystals, ceramics, and fibers with persistent or transient "spectral hole" recording properties for applications including high-bandwidth optical signal processing where light and our solids replace the high-bandwidth portion of the electronics; quantum cryptography and information science including the goal of storage and recall of single photons; and medical imaging technology for the 700-900 nm therapeutic window. Ease of optically manipulating rare-earth ions in solids enables capturing complex spectral information in 105 to 108 frequency bins. Combining spatial holography and spectral hole burning provides a capability for processing high-bandwidth RF and optical signals with sub-MHz spectral resolution and bandwidths of tens to hundreds of GHz for applications including range-Doppler radar and high bandwidth RF spectral analysis. Simply stated, one can think of these crystals as holographic recording media capable of distinguishing up to 108 different colors. Ultra-narrow spectral holes also serve as a vibration-insensitive sub-kHz frequency reference for laser frequency stabilization to a part in 1013 over tens of milliseconds. The unusual properties and applications of spectral hole burning of rare earth ions in optical materials are reviewed. Experimental results on the promising Tm3+:LiNbO3 material system are presented and discussed for medical imaging applications. Finally, a new application of these materials as dynamic optical filters for laser noise suppression is discussed along with experimental demonstrations and theoretical modeling of the process.

  4. The physics and chemistry of Earth's dynamic surface (Ralph Alger Bagnold Medal Lecture)

    Science.gov (United States)

    Kirchner, James W.

    2013-04-01

    Ralph Alger Bagnold became a Fellow of the Royal Society and one of the founders of modern geomorphology despite having no formal academic affiliation, no cadre of students or postdocs under his command, no steady financial support, and no scientific training beyond a second-class honors degree in engineering. What he did have, and used to great effect, were a deep curiosity about natural phenomena, a powerful physical intellect, a talent for clever experimentation, extensive opportunities to observe geomorphic processes at work in the field, and - perhaps most important of all - the time and freedom to focus his energies on significant scientific challenges. A hallmark of Bagnold's work is the artful compromise between the goal of simple, general, physical laws describing natural phenomena, and the practical necessity for observational empiricisms to account for the real-world complexities that cannot be incorporated explicitly into such simple laws. Efforts to find these sorts of artful compromises continue to the present day. Typically, both in Bagnold's work and in present-day geomorphology, one seeks mathematical process laws whose form embodies the "pure physics" of the problem, and whose coefficients subsume the inevitable observational empiricisms. Present-day geomorphologists have an array of new tools that open our eyes to temporal and spatial scales that were invisible to Bagnold and his contemporaries. These observations, in turn, have yielded new surprises and challenges, sometimes confounding our intuition about how geomorphic systems "should" behave. One surprise has been that decadal-scale erosion rates, as reflected in stream sediment loads and reservoir sedimentation rates, often differ from longer-term erosion rates by large multiples. In some agricultural landscapes, modern-day erosion rates greatly exceed the long-term background rate, as one might intuitively expect. In other landscapes, however, contemporary erosion rates can be a small

  5. Ultrafast electron, lattice and spin dynamics on rare earth metal surfaces. Investigated with linear and nonlinear optical techniques

    Energy Technology Data Exchange (ETDEWEB)

    Radu, I.E.

    2006-03-15

    This thesis presents the femtosecond laser-induced electron, lattice and spin dynamics on two representative rare-earth systems: The ferromagnetic gadolinium Gd(0001) and the paramagnetic yttrium Y(0001) metals. The employed investigation tools are the time-resolved linear reflectivity and second-harmonic generation, which provide complementary information about the bulk and surface/interface dynamics, respectively. The femtosecond laser excitation of the exchange-split surface state of Gd(0001) triggers simultaneously the coherent vibrational dynamics of the lattice and spin subsystems in the surface region at a frequency of 3 THz. The coherent optical phonon corresponds to the vibration of the topmost atomic layer against the underlying bulk along the normal direction to the surface. The coupling mechanism between phonons and magnons is attributed to the modulation of the exchange interaction J between neighbour atoms due to the coherent lattice vibration. This leads to an oscillatory motion of the magnetic moments having the same frequency as the lattice vibration. Thus these results reveal a new type of phonon-magnon coupling mediated by the modulation of the exchange interaction and not by the conventional spin-orbit interaction. Moreover, we show that coherent spin dynamics in the THz frequency domain is achievable, which is at least one order of magnitude faster than previously reported. The laser-induced (de)magnetization dynamics of the ferromagnetic Gd(0001) thin films have been studied. Upon photo-excitation, the nonlinear magneto-optics measurements performed in this work show a sudden drop in the spin polarization of the surface state by more than 50% in a <100 fs time interval. Under comparable experimental conditions, the time-resolved photoemission studies reveal a constant exchange splitting of the surface state. The ultrafast decrease of spin polarization can be explained by the quasi-elastic spin-flip scattering of the hot electrons among spin

  6. Rare Earth Luminescence in Phosphogypsum Waste Produced From Phosphate Ore Processing

    Directory of Open Access Journals (Sweden)

    Ines Hammas Nasri

    2015-06-01

    Full Text Available Luminescence properties of rare earth elements (Eu3+, Sm3+ and Ce3+ were investigated in phosphogypsum waste produced from the phosphoric acid manufacture. The presence of these elements was already confirmed after analysis of the phosphogypsum sample by inductively coupled plasma mass spectrometry, which showed total rare earths content about 350 ppm. The principal aim of this work is to use the photoluminescence technique for identifying 4f ions by the mutual relationship between excitation and emission spectra.  The obtained spectra may be used then as reliable references for monitoring rare earth elements during their extraction from phosphogypsum, any time that the inductively coupled plasma mass spectrometry is inapplicable.To find the most convenient conditions for observing Eu3+ emissions, a powder of calcium sulfate doped with europium (CaSO4: Eu (1% was synthesized. After comparison with the emission and excitation spectra of the synthetic gypsum, it was pointed out that excitation of the phosphogypsum selectively at 466 nm is the most suitable for observing Eu3+ emissions. These latter were obtained at around 556 nm and 603 nm.  Based on literature data, Sm3+ and Ce3+ emissions in the phosphogypsum were identified. Sm3+ lines were obtained at 567 nm and 602 nm after a selective excitation at the 4G5/2-6H7/2 transition (404 nm. Whereas cerium luminescence was only observed after calcination of the phosphogypsum sample at 900°C. Ce3+ emissions were obtained at around 305 nm and 326 nm after excitation of the calcined phosphogypsum at 254 nm. The effect of phosphogypsum impurities on the lifetime of rare earths emissions was also discussed.

  7. Velocity gradients in the Earth's upper mantle: insights from higher mode surface waves

    Science.gov (United States)

    Fishwick, Stewart; Maupin, Valerie; Afonso, Juan Carlos

    2016-04-01

    The majority of seismic tomographic models of the uppermost mantle beneath Precambrian regions show a positive velocity gradient from the Moho to depths of around 100 km. It is becoming increasingly well recognised that this gradient is not readily compatible with simple models of a craton with constant composition and a steady-state geotherm and more complex compositional variations are invoked to explain this feature. At these depths most of the models are dominated by data from fundamental mode surface waves, and the combination of the sensitivity kernels alongside the choice of model parameterisation means that the velocity gradient could be an artefact of the particular inversion. Indeed, recent work using thermodynamically consistent velocity models suggests that in some cases there is not a requirement of this style of gradient. We investigate this aspect of the mantle structure further by returning to the Sa phase. This phase can be considered as the build up of a wave packet due to the overlapping group velocities of higher modes at periods of around 8 - 30 s. Using the Australian shield as a test-case we compare waveforms built from three different styles of velocity model. Firstly, the 1D model AU3 (Gaherty & Jordan, 1995) which did incorporate the Sa phase as part of the waveform in their modelling. Secondly, recent tomographic models of the Australian continent are used, which include no a priori information from the phase. Thirdly, a thermodynamically consistent velocity model that fits the broad dispersion characteristics of the tomography is tested. Finally, these synthetic waveforms are compared to real data crossing the Australian shield. The results illustrate small, but clear, variations in waveform dependent on the velocity structure. Complicating factors in any analysis involve the importance of having good knowledge of the crustal structure and a very accurate source depth (particularly if this is similar to the average crustal thickness).

  8. Friction surface cladding: development of a solid state cladding process

    NARCIS (Netherlands)

    van der Stelt, A.A.

    2014-01-01

    Many industries including automotive, aerospace, electronics, shipbuilding, offshore, railway and heavy equipment employ surface modification technologies to change the surface properties of a manufactured product. Often, the surface is covered (coated) with a dissimilar clad layer for this purpose

  9. Teachers as Researchers: Using Estuarine Processes to Learn and Teach Earth System Interactions

    Science.gov (United States)

    Johnson, J.; Varner, R. K.; Bryce, J.; Finkel, L.; Froburg, E.; Graham, K.; Hale, S. R.; von Damm, K.; Scientific Crew, T.

    2008-12-01

    One component of the University of New Hampshire's Transforming Earth System Science Education (TESSE) project provides a research immersion experience (RIE) for middle and high school science teachers. The chief goal of this component of the program is to provide teachers with authentic research experiences that will sharpen their research skills by providing guidance in designing projects and in the gathering and interpreting of data. This intensive research experience provides a springboard for approaching authentic research in the classroom. A subset of the teachers participating in the TESSE project, many of them second-year participants, enrolled in a course providing Research Techniques in the Earth System Sciences for Teachers (ESST-2). Estuaries provide an ideal teaching laboratory for emphasizing interactions between the components of the Earth system. Accordingly, the course was centered around an estuary cruise in which teacher participants took air and water samples, measured parameters in the water column, and took several sediment cores. Onshore, the teacher teams carried out follow-up work, including gas analyses in air samples, gas and trace metal content analyses in collected water samples, grain size and related sedimentalogical analyses of the core samples, and extractable metal contents from the cores. The research experience culminated in a poster presentation of the results. The participants will use this field trip-based model to bring authentic research into their classrooms. The ESST-2 teachers also plan to present their results at a regional Geoscience society meeting.

  10. Optimization of vibratory welding process parameters using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Pravin Kumar; Kumar, S. Deepak; Patel, D.; Prasad, S. B. [National Institute of Technology Jamshedpur, Jharkhand (India)

    2017-05-15

    The current investigation was carried out to study the effect of vibratory welding technique on mechanical properties of 6 mm thick butt welded mild steel plates. A new concept of vibratory welding technique has been designed and developed which is capable to transfer vibrations, having resonance frequency of 300 Hz, into the molten weld pool before it solidifies during the Shielded metal arc welding (SMAW) process. The important process parameters of vibratory welding technique namely welding current, welding speed and frequency of the vibrations induced in molten weld pool were optimized using Taguchi’s analysis and Response surface methodology (RSM). The effect of process parameters on tensile strength and hardness were evaluated using optimization techniques. Applying RSM, the effect of vibratory welding parameters on tensile strength and hardness were obtained through two separate regression equations. Results showed that, the most influencing factor for the desired tensile strength and hardness is frequency at its resonance value, i.e. 300 Hz. The micro-hardness and microstructures of the vibratory welded joints were studied in detail and compared with those of conventional SMAW joints. Comparatively, uniform and fine grain structure has been found in vibratory welded joints.

  11. The surface sediment types and their rare earth element characteristics from the continental shelf of the northern south China sea

    Science.gov (United States)

    Wang, Shuhong; Zhang, Nan; Chen, Han; Li, Liang; Yan, Wen

    2014-10-01

    The grain size as well as some major and trace elements, including rare earth element (REE), for 273 surface sediment samples collected from the continental shelf of the northern South China Sea were analyzed in this study. The sediment types are mainly sandy silt and silt, making up 60% of the whole samples, and secondly are mud, sandy mud, muddy sand and silty sand, making up 28% of the whole samples, based on grain-size in which the Folk's classification was used. The total REE content (ΣREE) show a wide variation from 21 ppm to 244 ppm with an average value of 155 ppm, which similar to the average ΣREE of the China loess, but much different from that in deep-sea clay, showing a significant terrigenous succession. The REE contents in different sediment types vary greatly, mainly enriching in silt, sandy silt, mud and sandy mud. The REE distribution contours parallel to the coastal, presenting like strips and their contents gradually reduce with increasing distance from the coast. The high content of the western Pearl River Mouth, Shang/Xiachuan Islands and Hailing Bay might be regarded to the coastal current developed from the east to the west along to the Pearl River Mouth in the northern South China Sea. But the chondrite-normalized REE patterns in various sediment types have no difference, basically same as those of coastal rivers and upper crust. They all show relative enrichments in light rare earth element (LREE), noticeable negative Eu anomaly and no Ce anomaly, indicating that those sediments are terrigenous sediments and from the same source region. Further analysis suggest that the sedimentary environment in the study area is relatively stable and granite widely distributed in the South China mainland is the main source of REE, which are transported mainly by the Pearl River. The late diagenesis has little effect on the REE.

  12. Cosmogenic nuclides principles, concepts and applications in the earth surface sciences

    CERN Document Server

    Dunai, Tibor J

    2010-01-01

    This is the first book to provide a comprehensive and state-of-the-art introduction to the novel and fast-evolving topic of in-situ produced cosmogenic nuclides. It presents an accessible introduction to the theoretical foundations, with explanations of relevant concepts starting at a basic level and building in sophistication. It incorporates, and draws on, methodological discussions and advances achieved within the international CRONUS (Cosmic-Ray Produced Nuclide Systematics) networks. Practical aspects such as sampling, analytical methods and data-interpretation are discussed in detail and an essential sampling checklist is provided. The full range of cosmogenic isotopes is covered and a wide spectrum of in-situ applications are described and illustrated with specific and generic examples of exposure dating, burial dating, erosion and uplift rates and process model verification. Graduate students and experienced practitioners will find this book a vital source of information on the background concepts and...

  13. The subglacial Lake Vostok (East Antarctica) surface snow is Earth-bound DNA (and dust)-free

    Science.gov (United States)

    Bulat, S.; Marie, D.; Bulat, E.; Alekhina, I.; Petit, J.-R.

    2012-09-01

    came up with only contaminant bacterial phylotypes (mostly of human source). The bioexposure trials showed that even in one day of open exposure the gDNA of rather complex microbial community composition was fatally damaged in terms of long-, mid-range and short-size amplicon generation in PCR. All this testify for very harsh conditions for life to survive the climate conditions of Central East Antarctica which could be considered as a presentday 'zone mortale' or 'polar desert' for known Earthbound microbial life forms. In addition this means that no life seeds are expected to reach subglacial lakes and water reservoirs and establish indigenous lake microbiota during their transit through the thick and aged Antarctic ice sheet upon its bottom melting. In general the subglacial Lake Vostok surface (ice sheet as well) environ represents the unique test area (sterile - in fact Earth-bound DNA-free and clean - in fact Earth-bound dust-free) for advancing extraterrestrial (ET) life detection technologies and searching for ET life indices in AMMs and IDPs.

  14. Rapid response tools and datasets for post-fire modeling: linking Earth Observations and process-based hydrological models to support post-fire remediation

    Science.gov (United States)

    Miller, M. E.; Billmire, M.; Elliot, W. J.; Endsley, K. A.; Robichaud, P. R.

    2015-04-01

    Preparation is key to utilizing Earth Observations and process-based models to support post-wildfire mitigation. Post-fire flooding and erosion can pose a serious threat to life, property and municipal water supplies. Increased runoff and sediment delivery due to the loss of surface cover and fire-induced changes in soil properties are of great concern. Remediation plans and treatments must be developed and implemented before the first major storms in order to be effective. One of the primary sources of information for making remediation decisions is a soil burn severity map derived from Earth Observation data (typically Landsat) that reflects fire induced changes in vegetation and soil properties. Slope, soils, land cover and climate are also important parameters that need to be considered. Spatially-explicit process-based models can account for these parameters, but they are currently under-utilized relative to simpler, lumped models because they are difficult to set up and require spatially-explicit inputs (digital elevation models, soils, and land cover). Our goal is to make process-based models more accessible by preparing spatial inputs before a fire, so that datasets can be rapidly combined with soil burn severity maps and formatted for model use. We are building an online database (http://geodjango.mtri.org/geowepp /) for the continental United States that will allow users to upload soil burn severity maps. The soil burn severity map is combined with land cover and soil datasets to generate the spatial model inputs needed for hydrological modeling of burn scars. Datasets will be created to support hydrological models, post-fire debris flow models and a dry ravel model. Our overall vision for this project is that advanced GIS surface erosion and mass failure prediction tools will be readily available for post-fire analysis using spatial information from a single online site.

  15. Understanding surface processes 3D imaging from micro-scale to regional scale

    Science.gov (United States)

    Jaboyedoff, Michel; Abellan, Antonio; Carrea, Dario; Derron, Marc-Henri; Franz, Martin; Guerin, Antoine; Humair, Florian; Matasci, Battista; Michoud, Clément; Nicolet, Pierrick; Penna, Ivanna; Rudaz, Benjamin; Voumard, Jeremie; Wyser, Emmanuel

    2015-04-01

    The production of topography using remote sensing techniques has considerably been improved during the last fifteen years due to the advances in electronics and to the increase of computing power. The earth surface is monitored at all the scales using Space Shuttle Missions (SRTM) digital elevation model (DEM), or using laser scanner (LS), both terrestrial (TLS) and airborne (ALS), with accuracies that can reach up to less than 50 microns for observations of objects at meter scale. Recently, photogrammetry has been pushed by the progress of LiDAR and thanks to the advance in image recognition. It led to the development of new techniques such as structure-from-motion (SFM), which allows obtaining 3D point cloud based on several pictures of the same object taken from several point of views. Both LiDAR and Photogrammetry produce 3D point clouds. One of the current 3D applications is the surface changes, which is often based simply on the subtraction of DEM at different time intervals, leading to a simple superficial description of the natural processes without information on the mass transport. However, a point cloud has much more information than a simple surface. For instance, shape recognition can be used to track objects or deformations such as a rock mass toppling, either using the shape of the point cloud or a specific moving element. Such method permits, for instance, to study in detail pre-failure accelerations, and are now routinely used in mining industry. Other methods are coupling images and DEMs and are used, for example, to capture the surface vectors of displacements in order to deduce the surface deformations of landslides. These types of surveys have now broad applications to all kinds of erosional processes. The coastal retreat can be monitored, and it displays in some places several centimetres per year of retreat on average. The sediment transports in torrent are now better constraint showing clearly pulses. The seasonal cycles can as well be

  16. Formation of aggregated nanoparticle spheres through femtosecond laser surface processing

    Science.gov (United States)

    Tsubaki, Alfred T.; Koten, Mark A.; Lucis, Michael J.; Zuhlke, Craig; Ianno, Natale; Shield, Jeffrey E.; Alexander, Dennis R.

    2017-10-01

    A detailed structural and chemical analysis of a class of self-organized surface structures, termed aggregated nanoparticle spheres (AN-spheres), created using femtosecond laser surface processing (FLSP) on silicon, silicon carbide, and aluminum is reported in this paper. AN-spheres are spherical microstructures that are 20-100 μm in diameter and are composed entirely of nanoparticles produced during femtosecond laser ablation of material. AN-spheres have an onion-like layered morphology resulting from the build-up of nanoparticle layers over multiple passes of the laser beam. The material properties and chemical composition of the AN-spheres are presented in this paper based on scanning electron microscopy (SEM), focused ion beam (FIB) milling, transmission electron microscopy (TEM), and energy dispersive x-ray spectroscopy (EDX) analysis. There is a distinct difference in the density of nanoparticles between concentric rings of the onion-like morphology of the AN-sphere. Layers of high-density form when the laser sinters nanoparticles together and low-density layers form when nanoparticles redeposit while the laser ablates areas surrounding the AN-sphere. The dynamic nature of femtosecond laser ablation creates a variety of nanoparticles that make-up the AN-spheres including Si/C core-shell, nanoparticles that directly fragmented from the base material, nanoparticles with carbon shells that retarded oxidation, and amorphous, fully oxidized nanoparticles.

  17. Natural hazards for the Earth's civilization from space, 1. Cosmic ray influence on atmospheric processes

    Directory of Open Access Journals (Sweden)

    L. I. Dorman

    2008-04-01

    Full Text Available In this paper we give a short description of global natural disasters for the Earth's civilization from space: 1 Galactic and solar cosmic ray (CR influence on the atmospheric processes; 2 Impacts of great space magnetic storms during big Forbush-effects in CR, 3 Impacts of great radiation hazards from solar CR during flare energetic particle events, 4 Great impacts on planetary climate during periods of the Solar system capturing by molecular-dust clouds, 5 Catastrophic disasters from nearby Supernova explosions, and 6 Catastrophic disasters from asteroid impacts on the Earth. Some of these problems have been already studied (see e.g. Dorman, 1957, 1963a, b; Dorman and Miroshnichenko, 1968; Dorman, 1972, 1974, 1975a, b, 1978; Velinov et al., 1974; Miroshnichenko, 2001, 2003; Dorman, 2004, 2006, 2008. We present here a detailed treatment of the first disaster only, leaving to future papers the analysis of the other aspects.

  18. Multi-surface topography targeted plateau honing for the processing of cylinder liner surfaces of automotive engines

    Science.gov (United States)

    Lawrence, K. Deepak; Ramamoorthy, B.

    2016-03-01

    Cylinder bores of automotive engines are 'engineered' surfaces that are processed using multi-stage honing process to generate multiple layers of micro geometry for meeting the different functional requirements of the piston assembly system. The final processed surfaces should comply with several surface topographic specifications that are relevant for the good tribological performance of the engine. Selection of the process parameters in three stages of honing to obtain multiple surface topographic characteristics simultaneously within the specification tolerance is an important module of the process planning and is often posed as a challenging task for the process engineers. This paper presents a strategy by combining the robust process design and gray-relational analysis to evolve the operating levels of honing process parameters in rough, finish and plateau honing stages targeting to meet multiple surface topographic specifications on the final running surface of the cylinder bores. Honing experiments were conducted in three stages namely rough, finish and plateau honing on cast iron cylinder liners by varying four honing process parameters such as rotational speed, oscillatory speed, pressure and honing time. Abbott-Firestone curve based functional parameters (Rk, Rpk, Rvk, Mr1 and Mr2) coupled with mean roughness depth (Rz, DIN/ISO) and honing angle were measured and identified as the surface quality performance targets to be achieved. The experimental results have shown that the proposed approach is effective to generate cylinder liner surface that would simultaneously meet the explicit surface topographic specifications currently practiced by the industry.

  19. Creative computing with Landlab: an open-source toolkit for building, coupling, and exploring two-dimensional numerical models of Earth-surface dynamics

    Science.gov (United States)

    Hobley, Daniel E. J.; Adams, Jordan M.; Nudurupati, Sai Siddhartha; Hutton, Eric W. H.; Gasparini, Nicole M.; Istanbulluoglu, Erkan; Tucker, Gregory E.

    2017-01-01

    The ability to model surface processes and to couple them to both subsurface and atmospheric regimes has proven invaluable to research in the Earth and planetary sciences. However, creating a new model typically demands a very large investment of time, and modifying an existing model to address a new problem typically means the new work is constrained to its detriment by model adaptations for a different problem. Landlab is an open-source software framework explicitly designed to accelerate the development of new process models by providing (1) a set of tools and existing grid structures - including both regular and irregular grids - to make it faster and easier to develop new process components, or numerical implementations of physical processes; (2) a suite of stable, modular, and interoperable process components that can be combined to create an integrated model; and (3) a set of tools for data input, output, manipulation, and visualization. A set of example models built with these components is also provided. Landlab's structure makes it ideal not only for fully developed modelling applications but also for model prototyping and classroom use. Because of its modular nature, it can also act as a platform for model intercomparison and epistemic uncertainty and sensitivity analyses. Landlab exposes a standardized model interoperability interface, and is able to couple to third-party models and software. Landlab also offers tools to allow the creation of cellular automata, and allows native coupling of such models to more traditional continuous differential equation-based modules. We illustrate the principles of component coupling in Landlab using a model of landform evolution, a cellular ecohydrologic model, and a flood-wave routing model.

  20. TOPO-EUROPE: the geoscience of coupled deep Earth - surface processes.

    NARCIS (Netherlands)

    Cloetingh, S.A.P.L.; Ziegler, P.A.; Bogaard, P.J.F.; Andriessen, P.A.M.; Artemieva, I.M.; Bada, G.; van Balen, R.T.; Beekman, F.; Ben-Avraham, Z.; Brun, J.P.; Bunge, H.P.; Burov, E.; Carbonell, R.; Facenna, C.; Friedrich, A.; Gallart, J.; Green, A.; Heidbach, O.; Jones, A.G.; Matenco, L.C.; Mosar, J.; Oncken, O.; Pascal, C.; Peters, G.; Sliaupa, S.; Soesoo, A.; Spakman, W.; Stephenson, R.A.; Thybo, H.; Torsvik, T.H.; de Vicente, G.; Wenzel, F.; Wortel, M.J.R.

    2007-01-01

    TOPO-EUROPE addresses the 4-D topographic evolution of the orogens and intra-plate regions of Europe through a multidisciplinary approach linking geology, geophysics, geodesy and geotechnology. TOPO-EUROPE integrates monitoring, imaging, reconstruction and modelling of the interplay between

  1. A Geosynchronous Synthetic Aperture Provides for Disaster Management, Measurement of Soil Moisture, and Measurement of Earth-Surface Dynamics

    Science.gov (United States)

    Madsen, Soren; Komar, George (Technical Monitor)

    2001-01-01

    A GEO-based Synthetic Aperture Radar (SAR) could provide daily coverage of basically all of North and South America with very good temporal coverage within the mapped area. This affords a key capability to disaster management, tectonic mapping and modeling, and vegetation mapping. The fine temporal sampling makes this system particularly useful for disaster management of flooding, hurricanes, and earthquakes. By using a fairly long wavelength, changing water boundaries caused by storms or flooding could be monitored in near real-time. This coverage would also provide revolutionary capabilities in the field of radar interferometry, including the capability to study the interferometric signature immediately before and after an earthquake, thus allowing unprecedented studies of Earth-surface dynamics. Preeruptive volcano dynamics could be studied as well as pre-seismic deformation, one of the most controversial and elusive aspects of earthquakes. Interferometric correlation would similarly allow near real-time mapping of surface changes caused by volcanic eruptions, mud slides, or fires. Finally, a GEO SAR provides an optimum configuration for soil moisture measurement that requires a high temporal sampling rate (1-2 days) with a moderate spatial resolution (1 km or better). From a technological point of view, the largest challenges involved in developing a geosynchronous SAR capability relate to the very large slant range distance from the radar to the mapped area. This leads to requirements for large power or alternatively very large antenna, the ability to steer the mapping area to the left and right of the satellite, and control of the elevation and azimuth angles. The weight of this system is estimated to be 2750 kg and it would require 20 kW of DC-power. Such a system would provide up to a 600 km ground swath in a strip-mapping mode and 4000 km dual-sided mapping in a scan-SAR mode.

  2. Full-waveform Airborne and Spaceborne Laser Altimetry for Mapping and Sampling the Earth's Forests, Cryosphere, and Land surfaces

    Science.gov (United States)

    Blair, J. B.; Dubayah, R.; Hofton, M. A.; Luthcke, S. B.; Rabine, D.; Wake, S.; Coyle, B.; Stysley, P.; Salerno, C.

    2014-12-01

    Laser altimetry is an established technique for providing precise and accurate measurements of topography, vegetation, ice sheets, glaciers and sea ice. The Land, Vegetation, and Ice Sensor (LVIS) is a wide swath, full-waveform laser altimeter that has been operational since the late 1990's and has mapped 100,000's of square kilometers around the globe. NASA is developing a Facility version of the LVIS sensor to make it more cost-effective and more easily available to the broader science community. Based heavily on the existing LVIS sensor, the Facility LVIS instrument includes numerous improvements for reliability, resolution, real-time performance monitoring, lower cost for integration and ops, and data consistency. Building upon the foundation provided by LVIS, the Global Ecosystem Dynamics Investigation (GEDI) Lidar was recently selected for funding as a part of NASA's Earth Venture Program and will use multiple laser beams to measure high-resolution forest structure and surface topography from the International Space Station (ISS). Dependent on the funding profile and availability of launch options to ISS, GEDI could launch as early as 2018. Within a single year of operations GEDI will provide billions of vegetation height and structure measurements for the precise estimation of biomass within the orbital coverage provided by ISS (+/- 51.6 degrees latitude). GEDI uses the same high-SNR waveform measurement technique as the airborne LVIS sensor. LVIS will provide calibration and validation of GEDI's on-orbit performance.

  3. Land-surface processes and monsoon climate system

    Science.gov (United States)

    Xue, Yongkang; De Sales, Fernando; Lau, William; Boone, Arron; Mechoso, Carlos

    2015-04-01

    Yongkang Xue, F. De Sales, B. Lau, A. Boone, C. R. Mechoso Differential thermal heating of land and ocean and heat release into the atmosphere are important factors that determine the onset, strength, duration and spatial distribution of large-scale monsoons. A global and seasonal assessment of land surface process (LSP) effects on the monsoon system has been made based on general circulation models (GCM) coupled to different benchmark land models, which physically represent either comprehensive, or partial, or minimal LSP representations. Observed precipitation is applied as constrain and differences in simulation error are used to assess the effect of the LSP with different complexity. The AGCM results indicate that the land/atmosphere interaction has substantial impact on global water cycle, while the monsoon regions have had strongest impact at intraseasonal to decadal scales. Among monsoon regions, West Africa, South Asia, East Asia, and Amazon regions have largest impact while some monsoon regions have less impact due to strong air/sea interactions and narrow land mass there. LSP reduces the annual precipitation error by 58% over global monsoon regions, about 35% observed precipitation. The partial LSP effect (excluding soil moisture and vegetation albedo) reduces annual precipitation error over monsoon region that equals to about 13% of observed precipitation. The LSP affects the monsoon evolution through different mechanisms at different scales. It affects the surface energy balance and energy partitioning in latent and sensible heat, the atmospheric heating rate, and general circulation. The LSP effects have also been assessed in the land use land cover change experiment. Based on recently compiled global land-use data from 1948-2005, the GCM simulation results indicate the degradation in Mexico, West Africa, south and East Asia and South America produce substantial precipitation anomalies, some of which are consistent with observed regional precipitation

  4. River flow and inundation in African river systems: results from a new pan-African land-surface model validated against Earth observations

    Science.gov (United States)

    Dadson, Simon

    2015-04-01

    The role of surface-water flooding in controlling fluxes of water and carbon between the land and the atmosphere is increasingly recognized in studies of the Earth system. Simultaneous advances in remote earth observation and large-scale land-surface and hydrological modeling promise improvements in our ability to understand these linkages, and suggest that improvements in prediction of river flow and inundation extents may result. Here we present an analysis of newly-available observational estimates of surface water inundation obtained through satellite Earth observation with results from simulations produced by using the Joint UK Land Environment Simulator (JULES) land-surface model operating at 0.5 degree resolution over the African continent. The model was forced with meteorological input from the WATCH Forcing Data for the period 1981-2001 and sensitivity to various model configurations and parameter settings were tested. Both the PDM and TOPMODEL sub-grid scale runoff generation schemes were tested for parameter sensitivities, with the evaluation focussing on simulated river discharge in sub-catchments of the Congo, Nile, Niger, Orange, Okavango and Zambezi rivers. It was found that whilst the water balance in each of the catchments can be simulated with acceptable accuracy, the individual responses of each river vary between model configurations so that there is no single runoff parameterization scheme or parameter values that yields optimal results across all catchments. We trace these differences to the model's representation of sub-surface flow and make some suggestions to improve the performance of large-scale land-surface models for use in similar applications. These findings suggest that the use of Earth observation data together with improved models of large-scale hydrology have the potential to improve our ability to predict surface-water flooding and to develop our understanding of the role of flooding in driving components of the water and carbon

  5. Performance Modeling and Analysis of Parallel Processing and Low Earth Orbit Satellite Communication Systems

    Science.gov (United States)

    1994-01-01

    134 xii 9.8.1 The SatLab M oel...BONeS SatLab Interface M odule (BSIM ) ............................................................ 142 9.8.2.7 Satemnm router M odule...parallel processing systems can be grouped into one of two architectural categories: processor-to-iemory (P-M) or processing element-to-processing

  6. Our contaminated atmosphere: The danger of climate change, phases 1 and 2. [effect of atmospheric particulate matter on surface temperature and earth's radiation budget

    Science.gov (United States)

    Cimorelli, A. J.; House, F. B.

    1974-01-01

    The effects of increased concentrations of atmospheric particulate matter on average surface temperature and on the components of the earth's radiation budget are studied. An atmospheric model which couples particulate loading to surface temperature and to changes in the earth's radiation budget was used. A determination of the feasibility of using satellites to monitor the effect of increased atmospheric particulate concentrations is performed. It was found that: (1) a change in man-made particulate loading of a factor of 4 is sufficient to initiate an ice age; (2) variations in the global and hemispheric weighted averages of surface temperature, reflected radiant fluz and emitted radiant flux are nonlinear functions of particulate loading; and (3) a black satellite sphere meets the requirement of night time measurement sensitivity, but not the required day time sensitivity. A nonblack, spherical radiometer whose external optical properties are sensitive to either the reflected radiant fluz or the emitted radiant flux meets the observational sensitivity requirements.

  7. Influence of Surface Processing on the Biocompatibility of Titanium

    OpenAIRE

    Kornelia Wirsching; Pingling Kwok; Jürgen Strutz; Otto Gleich; Peter Jacob; Karla Lehle

    2011-01-01

    Surface conditioning of titanium middle ear implants results in an improved biocompatibility, which can be characterized by the properties of fibroblasts cultured on conditioned surfaces. Titanium has been established as a favorable biomaterial in ossicular chain reconstruction. The epithelization of the surface of the implants is important for their integration and stable positioning in the middle ear. Mouse fibroblast cells were cultured on platelets made from pure Grade 2 titanium. Platele...

  8. Gaining insights into interrill soil erosion processes using rare earth element tracers

    Science.gov (United States)

    Increasing interest in developing process-based erosion models requires better understanding of the relationships among soil detachment, transportation, and deposition. The objectives are to 1) identify the limiting process between soil detachment and sediment transport for interrill erosion, 2) und...

  9. Understanding erosion process using rare earth element tracers in a preformed interrill-rill system

    Science.gov (United States)

    Tracking sediment source and movement is essential to fully understanding soil erosion processes. The objectives of this study were to identify dominant erosion process and to characterize the effects of upslope interrill erosion on downslope interrill and rill erosion in a preformed interrill-rill ...

  10. Entrainment of bed material by Earth-surface mass flows: review and reformulation of depth-integrated theory

    Science.gov (United States)

    Iverson, Richard M.; Chaojun Ouyang,

    2015-01-01

    Earth-surface mass flows such as debris flows, rock avalanches, and dam-break floods can grow greatly in size and destructive potential by entraining bed material they encounter. Increasing use of depth-integrated mass- and momentum-conservation equations to model these erosive flows motivates a review of the underlying theory. Our review indicates that many existing models apply depth-integrated conservation principles incorrectly, leading to spurious inferences about the role of mass and momentum exchanges at flow-bed boundaries. Model discrepancies can be rectified by analyzing conservation of mass and momentum in a two-layer system consisting of a moving upper layer and static lower layer. Our analysis shows that erosion or deposition rates at the interface between layers must in general satisfy three jump conditions. These conditions impose constraints on valid erosion formulas, and they help determine the correct forms of depth-integrated conservation equations. Two of the three jump conditions are closely analogous to Rankine-Hugoniot conditions that describe the behavior of shocks in compressible gasses, and the third jump condition describes shear traction discontinuities that necessarily exist across eroding boundaries. Grain-fluid mixtures commonly behave as compressible materials as they undergo entrainment, because changes in bulk density occur as the mixtures mobilize and merge with an overriding flow. If no bulk density change occurs, then only the shear-traction jump condition applies. Even for this special case, however, accurate formulation of depth-integrated momentum equations requires a clear distinction between boundary shear tractions that exist in the presence or absence of bed erosion.

  11. Imaging the Earth's anisotropic structure with Bayesian Inversion of fundamental and higher mode surface-wave dispersion data

    Science.gov (United States)

    Ravenna, Matteo; Lebedev, Sergei; Celli, Nicolas

    2017-04-01

    We develop a Markov Chain Monte Carlo inversion of fundamental and higher mode phase-velocity curves for radially and azimuthally anisotropic structure of the crust and upper mantle. In the inversions of Rayleigh- and Love-wave dispersion curves for radially anisotropic structure, we obtain probabilistic 1D radially anisotropic shear-velocity profiles of the isotropic average Vs and anisotropy (or Vsv and Vsh) as functions of depth. In the inversions for azimuthal anisotropy, Rayleigh-wave dispersion curves at different azimuths are inverted for the vertically polarized shear-velocity structure (Vsv) and the 2-phi component of azimuthal anisotropy. The strength and originality of the method is in its fully non-linear approach. Each model realization is computed using exact forward calculations. The uncertainty of the models is a part of the output. In the inversions for azimuthal anisotropy, in particular, the computation of the forward problem is performed separately at different azimuths, with no linear approximations on the relation of the Earth's elastic parameters to surface wave phase velocities. The computations are performed in parallel in order reduce the computing time. We compare inversions of the fundamental mode phase-velocity curves alone with inversions that also include overtones. The addition of higher modes enhances the resolving power of the anisotropic structure of the deep upper mantle. We apply the inversion method to phase-velocity curves in a few regions, including the Hangai dome region in Mongolia. Our models provide constraints on the Moho depth, the Lithosphere-Asthenosphere Boundary, and the alignment of the anisotropic fabric and the direction of current and past flow, from the crust down to the deep asthenosphere.

  12. Inspection of surface-mount device images using wavelet processing

    Science.gov (United States)

    Carillo, Gerardo; Cabrera, Sergio D.; Portillo, Angel

    1997-02-01

    In this paper, the wavelet transform is used on surface mount device (SMD) images to devise a system used to inspect the presence of SMDs in printed circuit boards. The complete system involves preprocessing, feature extraction, and classification. The images correspond to three cases: SMD present (SMD), SMD not present with a speck of glue (GLUE), and SMD not present (noSMD). For each case, two images are collected using top and side illuminations but these are first combined into one image before proceeding to do further processing. Preprocessing is done by applying the wavelet transform to the images to expose details. Using 500 images for each of the three cases, various features are considered from different wavelet subbands, using one or several transform levels, to find four good discriminating parameters. Classification is performed sequentially using a two-level binary decision-tree. Two features are combined into a two-component feature vector and are fed into the first level that compares the SMD vs noSMD cases. The second level uses another feature vector produced by combining two other features and then compares the SMD and GLUE cases. The features used give no cluster overlap on the training set and simple parallelpiped classifier is devised at each level of the tree producing no errors on this set. Results give 99.6% correct classification when applied to a separate testing set consisting of 500 images for each case. All the errors are made to level 2 classifying six SMD images erroneously as GLUE.

  13. Process design of in situ esterification-transesterifica tion for biodiesel production from residual oil of spent bleaching earth (SBE)

    Science.gov (United States)

    Suryani, A.; Mubarok, Z.; Suprihatin; Romli, M.; Yunira, E. N.

    2017-05-01

    Indonesia is the largest producer of Crude Palm Oil (CPO) in the world. CPO refining process produces spent bleaching earth (SBE), which still contains 20-30% oil. This residual oil is very potential to be developed as a biodiesel feedstock. The purpose of this research was to develop an in situbiodiesel production process of residual oil of SBE, which covered stirring speed of esterification and transesterification and also transesterification time to produce biodiesel with the best characteristics. The production was conducted in a 100 L reactor. The stirring speeds applied were 650 rpm and 730 rpm, and the transesterification time varied at 60, 90 and 120 minutes. The combination of 730 rpm stirring speed for 90 minutes transesterification resulted in the best biodiesel characteristics with the yield of 85%, the specific energy of 6,738 kJ/kg and the heater efficiency of 48%. The physico-chemical properties of biodiesel was in conformity with the SNI of Biodiesel.

  14. [Effect of processes in the earth's crust on evolution of photosynthesis (as indicated by data on carbon isotopic composition)].

    Science.gov (United States)

    Ivlev, A A

    2010-01-01

    A probable mechanism of effect of processes occurring in the Earth's crust on evolution of photosynthesis is considered. According to the hypothesis, this effect is realized through entrance to the Earth's atmosphere of carbon dioxide that stimulates photosynthesis. Supply of CO2 is irregular and is due to irregular movements of the Earth's crust plates. This is accompanied by destruction of carbonates and conversion of carbon of the organic matter to CO2 due to processes of reduction of sulfates. The CO2 content in atmosphere rises for relatively short orogenic periods, due to intensive crust plate movement, while for the subsequent long periods, called the geosynclinal ones, of the relatively slow plate movement, the CO2 content falls due to the higher rate of its consumption for photosynthesis. Owing to the carbon isotopic fractionation accompanying photosynthesis, regular isotopic differences appear between the atmospheric CO2 and the "living" matter (Relay's effect); these differences are then transformed to isotope differences of the carbonate and organic carbon. At the appearance in atmosphere of free oxygen--product of photosynthesis--in organisms there appears photorespiration that also is accompanied by fractionation of carbon isotopes, but with effect of opposite sign. This leads to enrichment of the photosynthesizing biomass with 13C isotope at the orogenic periods. As a result, the initially pronounced isotope differences of the carbonate and organic carbon decrease by the end of the geosyclinal periods. According to the proposed model, concentrations of CO2 and O2 are exchanged in the antiphase. They lead to alternation of periods of warning up and cooling off on the Earth. The former coincide with the orogenic periods, the latter appear at the end of geosyclinal periods when oxygen is accumulated in atmosphere, while organic substance in sediments. Accumulation of organic substance leads to formation of petroleum-maternal masses. To substantiate the

  15. A Mobile Asteroid Surface Scout (MASCOT) on board the Hayabusa 2 Mission to the near Earth asteroid (162173) Ryugu

    Science.gov (United States)

    Jaumann, R.; Bibring, J. P.; Glassmeier, K. H.; Grott, M.; Ho, T. M.; Ulamec, S.; Schmitz, N.; Auster, H. U.; Biele, J.; Kuninaka, H.; Okada, T.; Yoshikawa, M.; Watanabe, S.; Spohn, T.; Koncz, A.; Hercik, D.; Michaelis, H.; Fujimoto, M.

    2016-12-01

    MASCOT is part of JAXA's Hayabusa 2 asteroid sample return mission that has been launched to asteroid (162173) Ryugu (1,2,3) on Dec 3rd, 2014. It is scheduled to arrive at Ryugu in 2018, and return samples to Earth in 2020. The German Aerospace Center (DLR) developed the lander MASCOT with contributions from CNES (France) (2,3). Ryugu has been classified as a Cg-type (4), believed to be a primitive volatile-rich remnant from the early solar system. Its visible geometric albedo is 0.07±0.01with a diameter of 0.87±0.03 km (5). The thermal inertia indicates thick dust with a cm-sized, gravel-dominated surface layer (5,6). Ryugu shows a retrograde rotation with a period of 7.63±0.01h. Spectral observations indicate iron-bearing phyllosilicates (1) on parts of the surface, suggesting compositional heterogeneity. MASCOT will enable to in-situ map the asteroid's geomorphology, the intimate structure, texture and composition of the regolith (dust, soil and rocks), and its thermal, mechanical, and magnetic properties in order to provide ground truth for the orbiter remote measurements, support the selection of sampling sites, and provide context information for the returned samples (2,3). MASCOT comprises a payload of four scientific instruments: camera, radiometer, magnetometer and hyperspectral microscope (2,3). Characterizing the properties of asteroid regolith in-situ will deliver important ground truth for further understanding telescopic and orbital observations as well as samples of asteroids. MASCOT will descend and land on the asteroid and will change its position by hopping (3). (1) Vilas, F., Astro. J. 1101-1105, 2008; (2) Jaumann, R., et al., SSR, DOI 10.1007/s11214-016-0263-2, 2016; (3) Ho, T.-M. et al., SSR, DOI 10.1007/s11214-016-0251-6, 2016; (4) Bus, S.J., Binzel, R.P. Icarus 158, 2002; (5) Hasegawa, T.G., et al., Astron. Soc. Japan 60, 2008; (6) T.G. Müller, T.G., et al., doi 10.1051/0004-6361/201015599, 2011.

  16. Final Report Collaborative Project: Improving the Representation of Coastal and Estuarine Processes in Earth System Models

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Frank [Univ. of Connecticut, Storrs, CT (United States); Dennis, John [Univ. of Connecticut, Storrs, CT (United States); MacCready, Parker [Univ. of Connecticut, Storrs, CT (United States); Whitney, Michael M. [Univ. of Connecticut, Storrs, CT (United States)

    2016-09-30

    This project aimed to improve long term global climate simulations by resolving and enhancing the representation of the processes involved in the cycling of freshwater through estuaries and coastal regions. This was a collaborative multi-institution project consisting of physical oceanographers, climate model developers, and computational scientists. It specifically targeted the DOE objectives of advancing simulation and predictive capability of climate models through improvements in resolution and physical process representation.

  17. Collaborative Project: Improving the Representation of Coastal and Estuarine Processes in Earth System Models

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Frank [Univ. of Washington, Seattle, WA (United States); Dennis, John [Univ. of Washington, Seattle, WA (United States); MacCready, Parker [Univ. of Washington, Seattle, WA (United States); Whitney, Michael [Univ. of Washington, Seattle, WA (United States)

    2016-10-20

    This project aimed to improve long term global climate simulations by resolving and enhancing the representation of the processes involved in the cycling of freshwater through estuaries and coastal regions. This was a collaborative multi-institution project consisting of physical oceanographers, climate model developers, and computational scientists. It specifically targeted the DOE objectives of advancing simulation and predictive capability of climate models through improvements in resolution and physical process representation.

  18. Stable surface passivation of silicon by low-temperature processing

    Energy Technology Data Exchange (ETDEWEB)

    Leguijt, C.; Loelgen, P. (FOM Institute for Atomic and Molecular Physics, Amsterdam (Netherlands)); Eikelboom, J.A.; Van der Heide, A.S.H.; Steeman, R.A.; Sinke, W.C. (Unit ECN Renewable Energy, Petten (Netherlands)); Sarro, P.M. (Delft Institute for Microelectronics and Submicron Technology DIMES, Delft (Netherlands)); Verhoef, L.A.; Michiels, P.P. (R+S Renewable Energy Systems, Helmond (Netherlands)

    1994-04-01

    Low-temperature passivation of silicon surfaces has been achieved by Plasma Enhanced Chemical Vapour Deposition (PECVD) of Si-oxide and Si-nitride in a batch reactor. An anneal at 400[sup o]C is shown to be crucial to obtain low surface recombination velocities. The obtained passivation has no correlation with the plasma power used for the deposition. The recombination velocity of a surface passivated with PECVD Si-oxide increases after the anneal on a timescale of hours, whereas the passivation with PECVD Si-nitride is stable. The interface chemistry and the role of hydrogen in the passivation mechanism is discussed. 2 figs., 3 tabs., 7 refs.

  19. Separation of technetium and rare earth metals for co-decontamination process

    Energy Technology Data Exchange (ETDEWEB)

    Riddle, Catherine; Martin, Leigh

    2015-05-01

    Poster. In the US there are several technologies under consideration for the separation of the useful components in used nuclear fuel. One such process is the co-decontamination process to separate U, Np and Pu in a single step and produce a Np/ Pu and a U product stream. Although the behavior of the actinide elements is reasonably well defined in this system, the same is not true for the fission products, mainly Zr, Mo, Ru and Tc. As these elements are cationic and anionic they may interact with each other to extract in a manner not predicted by empirical models such as AMUSE. This poster presentation will discuss the initial results of batch contact testing under flowsheet conditions and as a function of varying acidity and flowsheet conditions to optimize recovery of Tc and minimize extraction of Mo, Zr and Ru with the goal of developing a better understanding of the behavior of these elements in the co-decontamination process.

  20. Process for containment and deflection of aqueous surface pollutants

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, F.

    1970-01-20

    A method for containment and deflection of inorganic and organic aqueous surface pollutants, such as an oil slick, flotsam, debris, and jellyfish, and an apparatus for the operation of such method are described. This method comprises the generation of an air or bubble barrier which permits the passage of surface vessels and large fish, but halts the movement of floating surface pollutants by the creation of a flexible continuous band of surface turbulence. The system in one specific application is designed to protect harbor and beach areas and fishing grounds from contamination with oil from oil tankers and also acts as an air wall to keep harmful jellyfish from beach areas. The system can also be employed to recover oil from sunken or leaking tankers at sea by containment and collection of the oil released within the circumference of the bubble barrier wall created in a geometric pattern about the location of the stricken vessel. (10 claims)

  1. Electron beam processed plasticized epoxy coatings for surface protection

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Mervat S. [National Center for Radiation Research and Technology, Nasr City (Egypt); Mohamed, Heba A., E-mail: hebaamohamed@gmail.com [National Research Center, Dokki (Egypt); Kandile, Nadia G. [University College for Girls, Ain Shams University (Egypt); Said, Hossam M.; Mohamed, Issa M. [National Center for Radiation Research and Technology, Nasr City (Egypt)

    2011-10-17

    Highlights: {center_dot} Coating formulations with EA 70%, HD 20%, and castor oil 10% under 1 Mrad pass{sup -1} irradiation dose showed the best adhesion and passed bending tests. {center_dot} The prepared EP-SF-An adduct improve anti-corrosion properties of coatings without any significant effect on physical, mechanical and chemical properties of the cured film. The optimum amount of aniline adduct as corrosion inhibitor was found to be 0.4 g for 100 g of coating formulation. {center_dot} The corrosion inhibition efficiency of the prepared adduct competed the commercial efficiency. - Abstract: Epoxy acrylate oligomer (EA) was plasticized by adding different plasticizers such as epoxidized soybean oil, glycerol and castor oil and cured by electron beam (EB). Different irradiation doses (1, 2.5 and 5 Mrad pass{sup -1}) were used in the curing process. The effect of both different irradiation doses and plasticizers on the end use performance properties of epoxy acrylate coating namely, pencil hardness, bending test, adhesion test, acid and alkali resistance test were studied. It was observed that incorporation of castor oil in epoxy acrylate diluted by 1,6-hexanediol diacrylate (HD) monomer with a ratio (EA 70%, HD 20%, castor oil 10%) under 1 Mrad pass{sup -1} irradiation dose improved the physical, chemical and mechanical properties of cured films than the other plasticizer. Sunflower free fatty acid was epoxidized in situ under well established conditions. The epoxidized sunflower free fatty acids (ESFA) were subjected to react with aniline in sealed ampoules under inert atmosphere at 140 deg. C. The produced adducts were added at different concentrations to epoxy acrylate coatings under certain EB irradiation dose and then evaluated as corrosion inhibitors for carbon steel surfaces in terms of weight loss measurements and corrosion resistance tests. It was found that, addition of 0.4 g of aniline adduct to 100 g epoxy acrylate formula may give the best corrosion

  2. Recovery of Rare Earth Elements from Coal and Coal Byproducts via a Closed Loop Leaching Process: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Richard [Battelle Memorial Inst., Columbus, OH (United States); Heinrichs, Michael [Battelle Memorial Inst., Columbus, OH (United States); Argumedo, Darwin [Battelle Memorial Inst., Columbus, OH (United States); Taha, Rachid [Battelle Memorial Inst., Columbus, OH (United States); Winecki, Slawomir [Battelle Memorial Inst., Columbus, OH (United States); Johnson, Kathryn [Battelle Memorial Inst., Columbus, OH (United States); Lane, Ann [Battelle Memorial Inst., Columbus, OH (United States); Riordan, Daniel [Battelle Memorial Inst., Columbus, OH (United States)

    2017-08-31

    Objectives: Through this grant, Battelle proposes to address Area of Interest (AOI) 1 to develop a bench-scale technology to economically separate, extract, and concentrate mixed REEs from coal ash. U.S. coal and coal byproducts provide the opportunity for a domestic source of REEs. The DOE’s National Energy Technology Laboratory (NETL) has characterized various coal and coal byproducts samples and has found varying concentrations of REE ranging up to 1,000 parts per million by weight. The primary project objective is to validate the economic viability of recovering REEs from the coal byproduct coal ash using Battelle’s patented closed-loop Acid Digestion Process (ADP). This will be accomplished by selecting coal sources with the potential to provide REE concentrations above 300 parts per million by weight, collecting characterization data for coal ash samples generated via three different methods, and performing a Techno-Economic Analysis (TEA) for the proposed process. The regional availability of REE-laden coal ash, the regional market for rare earth concentrates, and the system capital and operating costs for rare earth recovery using the ADP technology will be accounted for in the TEA. Limited laboratory testing will be conducted to generate the parameters needed for the design of a bench scale system for REE recovery. The ultimate project outcome will be the design for an optimized, closed loop process to economically recovery REEs such that the process may be demonstrated at the bench scale in a Phase 2 project. Project Description: The project will encompass evaluation of the ADP technology for the economic recovery of REEs from coal and coal ash. The ADP was originally designed and demonstrated for the U.S. Army to facilitate demilitarization of cast-cured munitions via acid digestion in a closed-loop process. Proof of concept testing has been conducted on a sample of Ohio-based Middle Kittanning coal and has demonstrated the feasibility of recovering

  3. 30 CFR 912.764 - Process for designating areas unsuitable for surface coal mining operations.

    Science.gov (United States)

    2010-07-01

    ... operations. Part 764 of this chapter, State Processes for Designating Areas Unsuitable for Surface Coal... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Process for designating areas unsuitable for surface coal mining operations. 912.764 Section 912.764 Mineral Resources OFFICE OF SURFACE MINING...

  4. 30 CFR 910.764 - Process for designating areas unsuitable for surface coal mining operations.

    Science.gov (United States)

    2010-07-01

    ... operations. Part 764 of this chapter, State Processes for Designating Areas Unsuitable for Surface Coal... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Process for designating areas unsuitable for surface coal mining operations. 910.764 Section 910.764 Mineral Resources OFFICE OF SURFACE MINING...

  5. 30 CFR 941.764 - Process for designating areas unsuitable for surface coal mining operations.

    Science.gov (United States)

    2010-07-01

    ... operations. Part 764 of this chapter, State Processes for Designating Areas Unsuitable for Surface Coal... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Process for designating areas unsuitable for surface coal mining operations. 941.764 Section 941.764 Mineral Resources OFFICE OF SURFACE MINING...

  6. 30 CFR 939.764 - Process for designating areas unsuitable for surface coal mining operations.

    Science.gov (United States)

    2010-07-01

    ... operations. Part 764 of this chapter, State Processes for Designating Areas Unsuitable for Surface Coal... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Process for designating areas unsuitable for surface coal mining operations. 939.764 Section 939.764 Mineral Resources OFFICE OF SURFACE MINING...

  7. 30 CFR 922.764 - Process for designating areas unsuitable for surface coal mining operations.

    Science.gov (United States)

    2010-07-01

    ... operations. Part 764 of this chapter, State Processes for Designating Areas Unsuitable for Surface Coal... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Process for designating areas unsuitable for surface coal mining operations. 922.764 Section 922.764 Mineral Resources OFFICE OF SURFACE MINING...

  8. 30 CFR 942.764 - Process for designating areas unsuitable for surface coal mining operations.

    Science.gov (United States)

    2010-07-01

    ... operations. (a) Part 764 of this chapter, State Process for Designating Areas Unsuitable for Surface Coal... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Process for designating areas unsuitable for surface coal mining operations. 942.764 Section 942.764 Mineral Resources OFFICE OF SURFACE MINING...

  9. 30 CFR 947.764 - Process for designating areas unsuitable for surface coal mining operations.

    Science.gov (United States)

    2010-07-01

    ... operations. (a) Part 764 of this chapter, State Processes for Designating Areas Unsuitable for Surface Coal... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Process for designating areas unsuitable for surface coal mining operations. 947.764 Section 947.764 Mineral Resources OFFICE OF SURFACE MINING...

  10. 30 CFR 937.764 - Process for designating areas unsuitable for surface coal mining operations.

    Science.gov (United States)

    2010-07-01

    ... operations. Part 764 of this chapter, State Processes for Designating Areas Unsuitable for Surface Coal... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Process for designating areas unsuitable for surface coal mining operations. 937.764 Section 937.764 Mineral Resources OFFICE OF SURFACE MINING...

  11. 30 CFR 921.764 - Process for designating areas unsuitable for surface coal mining operations.

    Science.gov (United States)

    2010-07-01

    ... mining operations. Part 764 of this chapter, State Processes for Designating Areas Unsuitable for Surface... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Process for designating areas unsuitable for surface coal mining operations. 921.764 Section 921.764 Mineral Resources OFFICE OF SURFACE MINING...

  12. Manufacture of functional surfaces through combined application of tool manufacturing processes and Robot Assisted Polishing

    DEFF Research Database (Denmark)

    Eriksen, Rasmus Solmer; Arentoft, Mogens; Grønbæk, J.

    2012-01-01

    The tool surface topography is often a key parameter in the tribological performance of modern metal forming tools. A new generation of multifunctional surfaces is achieved by combination of conventional tool manufacturing processes with a novel Robot Assisted Polishing process. This novel surface...

  13. The Rare Earth Peak and the Astrophysical Location of the r Process

    Science.gov (United States)

    Mumpower, M. R.; McLaughlin, G. C.; Surman, R.; Steiner, A. W.

    The question of astrophysical site(s) for the rapid neutron capture or r process of nucleosynthesis remains one of the most challenging open problems in all of physics. Neutron star mergers and core collapse supernovae are the leading candidates, but conclusions regarding both are limited by our knowledge of nuclear physics far from stability. Current and future radioactive beam facilities will aid in this endeavor by providing a plethora of new nuclear data information to be used in theoretical simulations. We present a new theoretical framework which, if used in combination with future measurements, will give strong clues to the astrophysical site of the r process.

  14. Triangle geometry processing for surface modeling and cartesian grid generation

    Science.gov (United States)

    Aftosmis, Michael J [San Mateo, CA; Melton, John E [Hollister, CA; Berger, Marsha J [New York, NY

    2002-09-03

    Cartesian mesh generation is accomplished for component based geometries, by intersecting components subject to mesh generation to extract wetted surfaces with a geometry engine using adaptive precision arithmetic in a system which automatically breaks ties with respect to geometric degeneracies. During volume mesh generation, intersected surface triangulations are received to enable mesh generation with cell division of an initially coarse grid. The hexagonal cells are resolved, preserving the ability to directionally divide cells which are locally well aligned.

  15. Plasmaless cleaning process of silicon surface using chlorine trifluoride

    Science.gov (United States)

    Saito, Yoji; Yamaoka, Osamu; Yoshida, Akira

    1990-03-01

    Plasmaless etching using ClF3 gas around room temperature has been investigated for the silicon substrates with the various thicknesses of native oxide. The native oxide can be removed with ClF3 gas. A specular surface is obtained by ultraviolet light irradiation which remarkably accelerates the removal of the native oxide without changing the etch rate of silicon. The etched surface is analyzed with Auger electron measurement, indicating the existence of Cl atoms on it.

  16. Exploring Google Earth Engine platform for big data processing: classification of multi-temporal satellite imagery for crop mapping

    Science.gov (United States)

    Shelestov, Andrii; Lavreniuk, Mykola; Kussul, Nataliia; Novikov, Alexei; Skakun, Sergii

    2017-02-01

    Many applied problems arising in agricultural monitoring and food security require reliable crop maps at national or global scale. Large scale crop mapping requires processing and management of large amount of heterogeneous satellite imagery acquired by various sensors that consequently leads to a “Big Data” problem. The main objective of this study is to explore efficiency of using the Google Earth Engine (GEE) platform when classifying multi-temporal satellite imagery with potential to apply the platform for a larger scale (e.g. country level) and multiple sensors (e.g. Landsat-8 and Sentinel-2). In particular, multiple state-of-the-art classifiers available in the GEE platform are compared to produce a high resolution (30 m) crop classification map for a large territory ( 28,100 km2 and 1.0 M ha of cropland). Though this study does not involve large volumes of data, it does address efficiency of the GEE platform to effectively execute complex workflows of satellite data processing required with large scale applications such as crop mapping. The study discusses strengths and weaknesses of classifiers, assesses accuracies that can be achieved with different classifiers for the Ukrainian landscape, and compares them to the benchmark classifier using a neural network approach that was developed in our previous studies. The study is carried out for the Joint Experiment of Crop Assessment and Monitoring (JECAM) test site in Ukraine covering the Kyiv region (North of Ukraine) in 2013. We found that Google Earth Engine (GEE) provides very good performance in terms of enabling access to the remote sensing products through the cloud platform and providing pre-processing; however, in terms of classification accuracy, the neural network based approach outperformed support vector machine (SVM), decision tree and random forest classifiers available in GEE.

  17. Natural Language Processing and Machine Learning (NLP/ML): Applying Advances in Biomedicine to the Earth Sciences

    Science.gov (United States)

    Duerr, R.; Myers, S.; Palmer, M.; Jenkins, C. J.; Thessen, A.; Martin, J.

    2015-12-01

    Semantics underlie many of the tools and services available from and on the web. From improving search results to enabling data mashups and other forms of interoperability, semantic technologies have proven themselves. But creating semantic resources, especially re-usable semantic resources, is extremely time consuming and labor intensive. Why? Because it is not just a matter of technology but also of obtaining rough consensus if not full agreement amongst community members on the meaning and order of things. One way to develop these resources in a more automated way would be to use NLP/ML techniques to extract the required resources from large corpora of subject-specific text such as peer-reviewed papers where presumably a rough consensus has been achieved at least about the basics of the particular discipline involved. While not generally applied to Earth Sciences, considerable resources have been spent in other fields such as medicine on these types of techniques with some success. The NSF-funded ClearEarth project is applying the techniques developed for biomedicine to the cryosphere, geology, and biology in order to spur faster development of the semantic resources needed in these fields. The first area being addressed by the project is the cryosphere, specifically sea ice nomenclature where an existing set of sea ice ontologies are being used as the "Gold Standard" against which to test and validate the NLP/ML techniques. The processes being used, lessons learned and early results will be described.

  18. Mesoscale Raised Rim Depressions (MRRDs) on Earth: A Review of the Characteristics, Processes, and Spatial Distributions of Analogs for Mars

    Science.gov (United States)

    Burr, Devon M.; Bruno, Barbara C.; Lanagan, Peter D.; Glaze, Lori; Jaeger, Windy L.; Soare, Richard J.; Tseung, Jean-Michel Wan Bun; Skinner, James A. Jr.; Baloga, Stephen M.

    2008-01-01

    Fields of mesoscale raised rim depressions (MRRDs) of various origins are found on Earth and Mars. Examples include rootless cones, mud volcanoes, collapsed pingos, rimmed kettle holes, and basaltic ring structures. Correct identification of MRRDs on Mars is valuable because different MRRD types have different geologic and/or climatic implications and are often associated with volcanism and/or water, which may provide locales for biotic or prebiotic activity. In order to facilitate correct identification of fields of MRRDs on Mars and their implications, this work provides a review of common terrestrial MRRD types that occur in fields. In this review, MRRDs by formation mechanism, including hydrovolcanic (phreatomagmatic cones, basaltic ring structures), sedimentological (mud volcanoes), and ice-related (pingos, volatile ice-block forms) mechanisms. For each broad mechanism, we present a comparative synopsis of (i) morphology and observations, (ii) physical formation processes, and (iii) published hypothesized locations on Mars. Because the morphology for MRRDs may be ambiguous, an additional tool is provided for distinguishing fields of MRRDs by origin on Mars, namely, spatial distribution analyses for MRRDs within fields on Earth. We find that MRRDs have both distinguishing and similar characteristics, and observation that applies both to their mesoscale morphology and to their spatial distribution statistics. Thus, this review provides tools for distinguishing between various MRRDs, while highlighting the utility of the multiple working hypotheses approach.

  19. Mesoscale raised rim depressions (MRRDs) on Earth: A review of the characteristics, processes, and spatial distributions of analogs for Mars

    Science.gov (United States)

    Burr, Devon M.; Bruno, Barbara C.; Lanagan, Peter D.; Glaze, Lori S.; Jaeger, Windy L.; Soare, Richard J.; Wan Bun Tseung, Jean-Michel; Skinner, James A.; Baloga, Stephen M.

    2009-05-01

    Fields of mesoscale raised rim depressions (MRRDs) of various origins are found on Earth and Mars. Examples include rootless cones, mud volcanoes, collapsed pingos, rimmed kettle holes, and basaltic ring structures. Correct identification of MRRDs on Mars is valuable because different MRRD types have different geologic and/or climatic implications and are often associated with volcanism and/or water, which may provide locales for biotic or prebiotic activity. In order to facilitate correct identification of fields of MRRDs on Mars and their implications, this work provides a review of common terrestrial MRRD types that occur in fields. In this review, MRRDs by formation mechanism, including hydrovolcanic (phreatomagmatic cones, basaltic ring structures), sedimentological (mud volcanoes), and ice-related (pingos, volatile ice-block forms) mechanisms. For each broad mechanism, we present a comparative synopsis of (i) morphology and observations, (ii) physical formation processes, and (iii) published hypothesized locations on Mars. Because the morphology for MRRDs may be ambiguous, an additional tool is provided for distinguishing fields of MRRDs by origin on Mars, namely, spatial distribution analyses for MRRDs within fields on Earth. We find that MRRDs have both distinguishing and similar characteristics, and observation that applies both to their mesoscale morphology and to their spatial distribution statistics. Thus, this review provides tools for distinguishing between various MRRDs, while highlighting the utility of the multiple working hypotheses approach.

  20. The generic MESSy submodel TENDENCY (v1.0 for process-based analyses in Earth system models

    Directory of Open Access Journals (Sweden)

    R. Eichinger

    2014-07-01

    Full Text Available The tendencies of prognostic variables in Earth system models are usually only accessible, e.g. for output, as a sum over all physical, dynamical and chemical processes at the end of one time integration step. Information about the contribution of individual processes to the total tendency is lost, if no special precautions are implemented. The knowledge on individual contributions, however, can be of importance to track down specific mechanisms in the model system. We present the new MESSy (Modular Earth Submodel System infrastructure submodel TENDENCY and use it exemplarily within the EMAC (ECHAM/MESSy Atmospheric Chemistry model to trace process-based tendencies of prognostic variables. The main idea is the outsourcing of the tendency accounting for the state variables from the process operators (submodels to the TENDENCY submodel itself. In this way, a record of the tendencies of all process–prognostic variable pairs can be stored. The selection of these pairs can be specified by the user, tailor-made for the desired application, in order to minimise memory requirements. Moreover, a standard interface allows the access to the individual process tendencies by other submodels, e.g. for on-line diagnostics or for additional parameterisations, which depend on individual process tendencies. An optional closure test assures the correct treatment of tendency accounting in all submodels and thus serves to reduce the model's susceptibility. TENDENCY is independent of the time integration scheme and therefore the concept is applicable to other model systems as well. Test simulations with TENDENCY show an increase of computing time for the EMAC model (in a setup without atmospheric chemistry of 1.8 ± 1% due to the additional subroutine calls when using TENDENCY. Exemplary results reveal the dissolving mechanisms of the stratospheric tape recorder signal in height over time. The separation of the tendency of the specific humidity into the respective

  1. What does it take to build a medium scale scientific cloud to process significant amounts of Earth observation data?

    Science.gov (United States)

    Hollstein, André; Diedrich, Hannes; Spengler, Daniel

    2017-04-01

    The installment of the operational fleet of Sentinels by Copernicus offers an unprecedented influx of freely available Earth Observation data with Sentinel-2 being a great example. It offers a broad range of land applications due to its high spatial sampling from 10 m to 20 m and its multi-spectral imaging capabilities with 13 spectral bands. The open access policy allows unrestricted use by everybody and provides data downloads for on the respective sites. For a small area of interest and shorter time series, data processing, and exploitation can easily be done manually. However, for multi-temporal analysis of larger areas, the data size can quickly increase such that it is not manageable in practice on a personal computer which leads to an increasing interest in central data exploitation platforms. Prominent examples are GoogleEarth Engine, NASA Earth Exchange (NEX) or current developments such as CODE-DE in Germany. Open standards are still evolving, and the choice of a platform may create lock-in scenarios and a situation where scientists are not anymore in full control of all aspects of their analysis. Securing intellectual properties of researchers can become a major issue in the future. Partnering with a startup company that is dedicated to providing tools for farm management and precision farming, GFZ builds a small-scale science cloud named GTS2 for processing and distribution of Sentinel-2 data. The service includes a sophisticated atmospheric correction algorithm, spatial co-registration of time series data, as well as a web API for data distribution. This approach is different from the drag to centralized research using infrastructures controlled by others. By keeping the full licensing rights, it allows developing new business models independent from the initially chosen processing provider. Currently, data is held for the greater German area but is extendable to larger areas on short notice due to a scalable distributed network file system. For a

  2. A New Sensor for Surface Process Quantification in the Geosciences - Image-Assisted Tacheometers

    Science.gov (United States)

    Vicovac, Tanja; Reiterer, Alexander; Rieke-Zapp, Dirk

    2010-05-01

    The quantification of earth surface processes in the geosciences requires precise measurement tools. Typical applications for precise measurement systems involve deformation monitoring for geo-risk management, detection of erosion rates, etc. Often employed for such applications are laser scanners, photogrammetric sensors and image-assisted tacheometers. Image-assisted tacheometers offer the user (metrology expert) an image capturing system (CCD/CMOS camera) in addition to 3D point measurements. The images of the telescope's visual field are projected onto the camera's chip. The camera is capable of capturing panoramic image mosaics through camera rotation if the axes of the measurement system are driven by computer controlled motors. With appropriate calibration, these images are accurately geo-referenced and oriented since the horizontal and vertical angles of rotation are continuously measured and fed into the computer. The oriented images can then directly be used for direction measurements with no need for control points in object space or further photogrammetric orientation processes. In such a system, viewing angles must be addressed to chip pixels inside the optical field of view. Hence dedicated calibration methods have to be applied, an autofocus unit has to be added to the optical path, and special digital image processing procedures have to be used to detect the points of interest on the objects to be measured. We present such a new optical measurement system for measuring and describing 3D surfaces for geosciences. Besides the technique and methods some practical examples will be shown. The system was developed at the Vienna University of Technology (Institute of Geodesy and Geophysics) - two interdisciplinary research project, i-MeaS and SedyMONT, have been launched with the purpose of measuring and interpreting 3D surfaces and surface processes. For the in situ measurement of bed rock erosion the level of surveying accuracy required for recurring sub

  3. Time dependent neural network models for detecting changes of state in complex processes: applications in earth sciences and astronomy.

    Science.gov (United States)

    Valdés, Julio J; Bonham-Carter, Graeme

    2006-03-01

    A computational intelligence approach is used to explore the problem of detecting internal state changes in time dependent processes; described by heterogeneous, multivariate time series with imprecise data and missing values. Such processes are approximated by collections of time dependent non-linear autoregressive models represented by a special kind of neuro-fuzzy neural network. Grid and high throughput computing model mining procedures based on neuro-fuzzy networks and genetic algorithms, generate: (i) collections of models composed of sets of time lag terms from the time series, and (ii) prediction functions represented by neuro-fuzzy networks. The composition of the models and their prediction capabilities, allows the identification of changes in the internal structure of the process. These changes are associated with the alternation of steady and transient states, zones with abnormal behavior, instability, and other situations. This approach is general, and its sensitivity for detecting subtle changes of state is revealed by simulation experiments. Its potential in the study of complex processes in earth sciences and astrophysics is illustrated with applications using paleoclimate and solar data.

  4. Influence of rare-earth based orthovanadate nanoparticles and cerium oxide on bioenergetic processes in mitochondria of hepatocytes

    Directory of Open Access Journals (Sweden)

    Е. А. Аверченко

    2015-10-01

    Full Text Available The features of influence of newly synthesized nanoparticles (NPs based on the rare earth elements, namely orthovanadates and cerium oxide, with the different geometrical parameters on the mitochondrial potential (ΔΨm and respiration and oxidative phosphorylation of the liver were investigated. Reduction of ΔΨm, as well as the ATP level in isolated mitochondria under influence of orthovanadates and CeO2 (1-2 nm NPs suggests that energy processes in the mitochondria are the target of the action of NPs. The highest inhibitory effect was shown by ekstrasmall spherical (orthovanadate and CeO2 of 1-2 nm particles and only CeO2 with sizes of 8-10 nm have no a negative influence on all investigated parameters.

  5. Dental Surface Texture Characterization Based on Erosive Tooth Wear Processes.

    Science.gov (United States)

    Hara, A T; Livengood, S V; Lippert, F; Eckert, G J; Ungar, P S

    2016-05-01

    The differential diagnosis of dental wear lesions affects their clinical management. We hypothesized that surface texture parameters can differentiate simulated erosion, abrasion, and erosion-abrasion lesions on human enamel and dentin. This in vitro study comprised 2 parts (both factorial 4 × 2), with 4 lesion types (erosion, abrasion, erosion-abrasion, and sound [no lesion; control]) and 2 substrates (enamel and dentin). Flattened/polished dental specimens were used in part 1, whereas natural dental surfaces were used in part 2. Testing surfaces were evaluated in blind conditions, using average surface roughness (Sa) and the following scale-sensitive fractal analysis parameters: area-scale fractal complexity (Asfc), exact proportion length-scale anisotropy of relief (eplsar), scale of maximum complexity (Smc), and textural fill volume (Tfv). Two-way analyses of variance, followed by Fisher's protected least significant difference tests (α = 0.05), were used to evaluate the effects of lesion and substrate. Classification trees were constructed to verify the strength of potential associations of the tested parameters. In part 1,Asfc, Sa, and Tfv were able to differentiate erosion and erosion-abrasion lesions from the sound (no lesion) control in both substrates; only Asfc differentiated erosion and erosion-abrasion enamel lesions (allPabrasion lesions from the sound (no lesion) control in both substrates, whereas eplsar was able to differentiate erosion from erosion-abrasion (allPabrasion lesions, despite their complicated surface textures. The association of parameters improved the differentiation of lesions for both enamel and dentin in polished or natural surfaces. © International & American Associations for Dental Research 2016.

  6. Forecasting tidal marsh elevation and habitat change through fusion of Earth observations and a process model

    Science.gov (United States)

    Byrd, Kristin B.; Windham-Myers, Lisamarie; Leeuw, Thomas; Downing, Bryan D.; Morris, James T.; Ferner, Matthew C.

    2016-01-01

    Reducing uncertainty in data inputs at relevant spatial scales can improve tidal marsh forecasting models, and their usefulness in coastal climate change adaptation decisions. The Marsh Equilibrium Model (MEM), a one-dimensional mechanistic elevation model, incorporates feedbacks of organic and inorganic inputs to project elevations under sea-level rise scenarios. We tested the feasibility of deriving two key MEM inputs—average annual suspended sediment concentration (SSC) and aboveground peak biomass—from remote sensing data in order to apply MEM across a broader geographic region. We analyzed the precision and representativeness (spatial distribution) of these remote sensing inputs to improve understanding of our study region, a brackish tidal marsh in San Francisco Bay, and to test the applicable spatial extent for coastal modeling. We compared biomass and SSC models derived from Landsat 8, DigitalGlobe WorldView-2, and hyperspectral airborne imagery. Landsat 8-derived inputs were evaluated in a MEM sensitivity analysis. Biomass models were comparable although peak biomass from Landsat 8 best matched field-measured values. The Portable Remote Imaging Spectrometer SSC model was most accurate, although a Landsat 8 time series provided annual average SSC estimates. Landsat 8-measured peak biomass values were randomly distributed, and annual average SSC (30 mg/L) was well represented in the main channels (IQR: 29–32 mg/L), illustrating the suitability of these inputs across the model domain. Trend response surface analysis identified significant diversion between field and remote sensing-based model runs at 60 yr due to model sensitivity at the marsh edge (80–140 cm NAVD88), although at 100 yr, elevation forecasts differed less than 10 cm across 97% of the marsh surface (150–200 cm NAVD88). Results demonstrate the utility of Landsat 8 for landscape-scale tidal marsh elevation projections due to its comparable performance with the other sensors

  7. Effect of finishing process on the surface quality of Co-Cr-Mo dental alloys

    Directory of Open Access Journals (Sweden)

    Dorota Klimecka -Tatar

    2016-09-01

    Full Text Available Preparatory procedures for the material have a significant influence on the surface stereometry of the material. This study investigated the effect of the electropolishing process on the surface quality of metallic prosthetic constructions based on Co-Cr-Mo alloys. It has been found that the process of electropolishing prevents to excessive development of the surface of a material and consequently improves surface quality.

  8. Directionally Solidified Aluminum - 7 wt% Silicon Alloys: Comparison of Earth and International Space Station Processed Samples

    Science.gov (United States)

    Grugel, Richard N,; Tewari, Surendra; Rajamure, R. S.; Erdman, Robert; Poirier, David

    2012-01-01

    Primary dendrite arm spacings of Al-7 wt% Si alloy directionally solidified in low gravity environment of space (MICAST-6 and MICAST-7: Thermal gradient approx. 19 to 26 K/cm, Growth speeds varying from 5 to 50 microns/s show good agreement with the Hunt-Lu model. Primary dendrite trunk diameters of the ISS processed samples show a good fit with a simple analytical model based on Kirkwood s approach, proposed here. Natural convection, a) decreases primary dendrite arm spacing. b) appears to increase primary dendrite trunk diameter.

  9. Remote sensing and geochemical investigations of selected surface processes in Egypt and Missouri

    Science.gov (United States)

    Crombie, Mary Katherine

    This thesis consists of three studies of surface processes on Earth: 1. Age and isotopic constraints of pluvial episodes in the Western Desert of Egypt. North Africa has undergone drastic climatic change over the past several hundred thousand years. Timing of humid intervals called pluvials was investigated by uranium- series disequilibrium dating of travertines from the Kurkur Oasis, Western Desert, Egypt. Stable oxygen isotopes of the travertines were used in equilibrium oxygen isotope fractionation calculations indicating the Kurkur travertines have δ18O values similar to ancient Western Desert groundwaters (~[- ]11/perthous). The ages of the of the travertines correspond to times of monsoonal maxima, eustatic sea level high stands and interglacial maxima. Increased precipitation, recharge of Western Desert groundwaters, and resultant travertine deposition are interpreted to be consequences of Milankovitch cycle forcing, through enhanced Atlantic and Indian Ocean monsoons during periods of enhanced northern summer insolation. 2. Identification of soil moisture as an environmental risk factor for filariasis in Egypt. Bancroftian filariasis is a deforming illness transmitted by mosquitoes (Culex. pipiens) and caused by the parasite Wuchereria bancrofti (WHO technical report 821; Neva and Brown, 1994). Environmental variables, such as humidity, play an important role in the transmission cycle of filariasis. Landsat Thematic Mapper data were used to model the surface soil moisture conditions of the southern Nile Delta region of Egypt as a proxy for environmental humidity. Filariasis infection rates were found to be negligible for areas with low surface soil moisture availability (>20%). Variable infection rates were observed for regions with higher surface soil moisture content, possibly due to anthropogenic influences such as insect control and the use of anti- filarial drugs. 3. Monitoring of Pb aerosol fallout in the vicinity of the Glover smelter, Southeastern

  10. Nano surface generation of grinding process using carbon nano tubes

    Indian Academy of Sciences (India)

    Nano surface finish has become an important parameter in the semiconductor, optical, electrical and mechanical industries. The materials used in these industries are classified as difficult to machine materials such as ceramics, glasses and silicon wafers. Machining of these materials up to nano accuracy is a great ...

  11. Stochastic Modeling and Deterministic Limit of Catalytic Surface Processes

    DEFF Research Database (Denmark)

    Starke, Jens; Reichert, Christian; Eiswirth, Markus

    2007-01-01

    Three levels of modeling, microscopic, mesoscopic and macroscopic are discussed for the CO oxidation on low-index platinum single crystal surfaces. The introduced models on the microscopic and mesoscopic level are stochastic while the model on the macroscopic level is deterministic. It can be der...

  12. Shewanella putrefaciens adhesion and biofilm formation on food processing surfaces

    DEFF Research Database (Denmark)

    Bagge, Dorthe; Hjelm, M.; Johansen, C.

    2001-01-01

    of bacteria on the surface must be quantified to evaluate the influence of environmental factors on adhesion and biofilm formation. We used a combination of fluorescence microscopy (4',6'-diamidino-2-phenylindole staining and in situ hybridization, for mixed-culture studies), ultrasonic removal of bacteria...

  13. Acoustic emission-based in-process monitoring of surface generation in robot-assisted polishing

    DEFF Research Database (Denmark)

    Pilny, Lukas; Bissacco, Giuliano; De Chiffre, Leonardo

    2016-01-01

    The applicability of acoustic emission (AE) measurements for in-process monitoring of surface generation in the robot-assisted polishing (RAP) was investigated. Surface roughness measurements require interruption of the process, proper surface cleaning and measurements that sometimes necessitate...... removal of the part from the machine tool. In this study, stabilisation of surface roughness during polishing rotational symmetric surfaces by the RAP process was monitored by AE measurements. An AE sensor was placed on a polishing arm in direct contact with a bonded abrasive polishing tool...

  14. The life history of Pseudomonas syringae: linking agriculture to earth system processes.

    Science.gov (United States)

    Morris, Cindy E; Monteil, Caroline L; Berge, Odile

    2013-01-01

    The description of the ecology of Pseudomonas syringae is moving away from that of a ubiquitous epiphytic plant pathogen to one of a multifaceted bacterium sans frontières in fresh water and other ecosystems linked to the water cycle. Discovery of the aquatic facet of its ecology has led to a vision of its life history that integrates spatial and temporal scales spanning billions of years and traversing catchment basins, continents, and the planet and that confronts the implication of roles that are potentially conflicting for agriculture (as a plant pathogen and as an actor in processes leading to rain and snowfall). This new ecological perspective has also yielded insight into epidemiological phenomena linked to disease emergence. Overall, it sets the stage for the integration of more comprehensive contexts of ecology and evolutionary history into comparative genomic analyses to elucidate how P. syringae subverts the attack and defense responses of the cohabitants of the diverse environments it occupies.

  15. Understanding, representing and communicating earth system processes in weather and climate within CNRCWP

    Science.gov (United States)

    Sushama, Laxmi; Arora, Vivek; de Elia, Ramon; Déry, Stephen; Duguay, Claude; Gachon, Philippe; Gyakum, John; Laprise, René; Marshall, Shawn; Monahan, Adam; Scinocca, John; Thériault, Julie; Verseghy, Diana; Zwiers, Francis

    2017-04-01

    The Canadian Network for Regional Climate and Weather Processes (CNRCWP) provides significant advances and innovative research towards the ultimate goal of reducing uncertainty in numerical weather prediction and climate projections for Canada's Northern and Arctic regions. This talk will provide an overview of the Network and selected results related to the assessment of the added value of high-resolution modelling that has helped fill critical knowledge gaps in understanding the dynamics of extreme temperature and precipitation events and the complex land-atmosphere interactions and feedbacks in Canada's northern and Arctic regions. In addition, targeted developments in the Canadian regional climate model, that facilitate direct application of model outputs in impact and adaptation studies, particularly those related to the water, energy and infrastructure sectors will also be discussed. The close collaboration between the Network and its partners and end users contributed significantly to this effort.

  16. The electromagnetic effect on the critical ionization velocity process. [in earth atmosphere

    Science.gov (United States)

    Machida, S.; Goertz, C. K.

    1988-01-01

    Electromagnetic effects on the critical ionization velocity (CIV) process become important when the neutral gas velocity V(n) exceeds the local Alfven speed V(A). The electron heating due to unstable lower hybrid waves necessary for CIV still occurs, but the efficiency of the electron heating is significantly reduced when the electromagnetic effect comes into play. This is verified by a series of simulation runs using two-dimensional electromagnetic particle code combined with PANIC. The significance of the electromagnetic effects for the occurrence of CIV in the comet-solar wind interaction and other space phenomena is briefly discussed. It is found that the comet environment is marginal for the excitation of CIV.

  17. Technospheric Mining of Rare Earth Elements from Bauxite Residue (Red Mud): Process Optimization, Kinetic Investigation, and Microwave Pretreatment.

    Science.gov (United States)

    Reid, Sable; Tam, Jason; Yang, Mingfan; Azimi, Gisele

    2017-11-10

    Some rare earth elements (REEs) are classified under critical materials, i.e., essential in use and subject to supply risk, due to their increasing demand, monopolistic supply, and environmentally unsustainable and expensive mining practices. To tackle the REE supply challenge, new initiatives have been started focusing on their extraction from alternative secondary resources. This study puts the emphasis on technospheric mining of REEs from bauxite residue (red mud) produced by the aluminum industry. Characterization results showed the bauxite residue sample contains about 0.03 wt% REEs. Systematic leaching experiments showed that concentrated HNO3 is the most effective lixiviant. However, because of the process complexities, H2SO4 was selected as the lixiviant. To further enhance the leaching efficiency, a novel process based on microwave pretreatment was employed. Results indicated that microwave pretreatment creates cracks and pores in the particles, enabling the lixiviant to diffuse further into the particles, bringing more REEs into solution, yielding of 64.2% and 78.7% for Sc and Nd, respectively, which are higher than the maximum obtained when HNO3 was used. This novel process of "H2SO4 leaching-coupled with-microwave pretreatment" proves to be a promising technique that can help realize the technological potential of REE recovery from secondary resources, particularly bauxite residue.

  18. An analytical solution for the elastic response to surface loads imposed on a layered, transversely isotropic and self-gravitating Earth

    Science.gov (United States)

    Pan, E.; Chen, J. Y.; Bevis, M.; Bordoni, A.; Barletta, V. R.; Molavi Tabrizi, A.

    2015-12-01

    We present an analytical solution for the elastic deformation of an elastic, transversely isotropic, layered and self-gravitating Earth by surface loads. We first introduce the vector spherical harmonics to express the physical quantities in the layered Earth. This reduces the governing equations to a linear system of equations for the expansion coefficients. We then solve for the expansion coefficients analytically under the assumption (i.e. approximation) that in the mantle, the density in each layer varies as 1/r (where r is the radial coordinate) while the gravity is constant and that in the core the gravity in each layer varies linearly in r with constant density. These approximations dramatically simplify the subsequent mathematical analysis and render closed-form expressions for the expansion coefficients. We implement our solution in a MATLAB code and perform a benchmark which shows both the correctness of our solution and the implementation. We also calculate the load Love numbers (LLNs) of the PREM Earth for different degrees of the Legendre function for both isotropic and transversely isotropic, layered mantles with different core models, demonstrating for the first time the effect of Earth anisotropy on the LLNs.

  19. Earth mortars and earth-lime renders

    Directory of Open Access Journals (Sweden)

    Maria Fernandes

    2008-01-01

    Full Text Available Earth surface coatings play a decorative architectural role, apart from their function as wall protection. In Portuguese vernacular architecture, earth mortars were usually applied on stone masonry, while earth renders and plasters were used on indoors surface coatings. Limestone exists only in certain areas of the country and consequently lime was not easily available everywhere, especially on granite and schist regions where stone masonry was a current building technique. In the central west coast of Portugal, the lime slaking procedure entailed slaking the quicklime mixed with earth (sandy soil, in a pit; the resulting mixture would then be combined in a mortar or plaster. This was also the procedure for manufactured adobes stabilized with lime. Adobe buildings with earth-lime renderings and plasters were also traditional in the same region, using lime putty and lime wash for final coat and decoration. Classic decoration on earth architecture from the 18th-19th century was in many countries a consequence of the François Cointeraux (1740-1830 manuals - Les Cahiers d'Architecture Rurale" (1793 - a French guide for earth architecture and building construction. This manual arrived to Portugal in the beginning of XIX century, but was never translated to Portuguese. References about decoration for earth houses were explained on this manual, as well as procedures about earth-lime renders and ornamentation of earth walls; in fact, these procedures are exactly the same as the ones used in adobe buildings in this Portuguese region. The specific purpose of the present paper is to show some cases of earth mortars, renders and plasters on stone buildings in Portugal and to explain the methods of producing earth-lime renders, and also to show some examples of rendering and coating with earth-lime in Portuguese adobe vernacular architecture.

  20. Atmospheric mercury accumulation and washoff processes on impervious urban surfaces

    Science.gov (United States)

    Eckley, C.S.; Branfireun, B.; Diamond, M.; Van Metre, P.C.; Heitmuller, F.

    2008-01-01

    The deposition and transport of mercury (Hg) has been studied extensively in rural environments but is less understood in urbanized catchments, where elevated atmospheric Hg concentrations and impervious surfaces may efficiently deliver Hg to waterways in stormwater runoff. We determined the rate at which atmospheric Hg accumulates on windows, identified the importance of washoff in removing accumulated Hg, and measured atmospheric Hg concentrations to help understand the relationship between deposition and surface accumulation. The main study location was Toronto, Ontario. Similar samples were also collected from Austin, Texas for comparison of Hg accumulation between cities. Windows provided a good sampling surface because they are ubiquitous in urban environments and are easy to clean/blank allowing the assessment of contemporary Hg accumulation. Hg Accumulation rates were spatially variable ranging from 0.82 to 2.7 ng m-2 d-1 in Toronto and showed similar variability in Austin. The highest accumulation rate in Toronto was at the city center and was 5?? higher than the rural comparison site (0.58 ng m-2 d-1). The atmospheric total gaseous mercury (TGM) concentrations were less than 2?? higher between the rural and urban locations (1.7 ?? 0.3 and 2.7 ?? 1.1 ng m-3, respectively). The atmospheric particulate bound fraction (HgP), however, was more than 3?? higher between the rural and urban sites, which may have contributed to the higher urban Hg accumulation rates. Windows exposed to precipitation had 73 ?? 9% lower accumulation rates than windows sheltered from precipitation. Runoff collected from simulated rain events confirmed that most Hg accumulated on windows was easily removed and that most of the Hg in washoff was HgP. Our results indicate that the Hg flux from urban catchments will respond rapidly to changes in atmospheric concentrations due to the mobilization of the majority of the surface accumulated Hg during precipitation events. ?? 2008 Elsevier

  1. Development of a Mantle Convection Physical Model to Assist with Teaching about Earth's Interior Processes

    Science.gov (United States)

    Glesener, G. B.; Aurnou, J. M.

    2010-12-01

    The Modeling and Educational Demonstrations Laboratory (MEDL) at UCLA is developing a mantle convection physical model to assist educators with the pedagogy of Earth’s interior processes. Our design goal consists of two components to help the learner gain conceptual understanding by means of visual interactions without the burden of distracters, which may promote alternative conceptions. Distracters may be any feature of the conceptual model that causes the learner to use inadequate mental artifact to help him or her understand what the conceptual model is intended to convey. The first component, and most important, is a psychological component that links properties of “everyday things” (Norman, 1988) to the natural phenomenon, mantle convection. Some examples of everyday things may be heat rising out from a freshly popped bag of popcorn, or cold humid air falling from an open freezer. The second component is the scientific accuracy of the conceptual model. We would like to simplify the concepts for the learner without sacrificing key information that is linked to other natural phenomena the learner will come across in future science lessons. By taking into account the learner’s mental artifacts in combination with a simplified, but accurate, representation of what scientists know of the Earth’s interior, we expect the learner to have the ability to create an adequate qualitative mental simulation of mantle convection. We will be presenting some of our prototypes of this mantle convection physical model at this year’s poster session and invite constructive input from our colleagues.

  2. Rare earth elements mobility processes in an AMD-affected estuary: Huelva Estuary (SW Spain).

    Science.gov (United States)

    Lecomte, K L; Sarmiento, A M; Borrego, J; Nieto, J M

    2017-08-15

    Huelva Estuary is a transition zone where REE-rich acidic waters interact with saline-alkaline seawater. This mixing process influences the geochemical and mineralogical characteristics of particulate and dissolved fractions. The Tinto River has >11,000μgL-1 dissolved REE (pH=1.66), whereas seawater only reaches 8.75·10-2μgL-1 dissolved REE (pH=7.87). REE-normalized patterns in "pH<6 solutions" are parallel and show similarities, diminishing their concentration as pH increases. Sequential extraction performed on the generated precipitates of mixed solutions indicates that most REE are associated to the residual phase. In a second order, REE are associated with soluble salts at pH3 and 3.5 whereas in sediments generated at pH4 and 5, they are distributed in salts (1° extraction), poorly crystallized Fe-bearing minerals (schwertmannite, 3° extraction) and well crystallized Fe-bearing minerals (goethite - hematite, 4° extraction). Finally, precipitated REE are highest at pH6 newly formed minerals with a release to solution in higher pH. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Processes Influencing the Timing and Volume of Eruptions From the Youngest Supervolcano on Earth

    Science.gov (United States)

    Wilson, C. J. N.; Barker, S. J.; Morgan, D. J.; Rowland, J. V.; Schipper, I.

    2015-12-01

    In their stratigraphic records, silicic caldera volcanoes display wide ranges of eruptive styles and volumes. However, relationships between frequency and magnitude are often complex, and the forecasting of future activity is inherently problematic. Taupo volcano, New Zealand, provides a unique opportunity to investigate eruptive histories from a hyperactive, large silicic magmatic system with eruptive volumes that span 3-4 orders of magnitude, and show no clear relationships with the repose period. Taupo hosted the world's most recent supereruption at 25.4 ka, which discharged 530 km3 of magma in the episodic 10-phase Oruanui event. Only 5 kyr later, Taupo revived, with 3 dacitic eruptions from 21.5-17 ka and 25 rhyolite eruptions from 12-1.7 ka. Here we use trends in whole rock, glass and mineral chemistry to show how the magma system reestablished following the Oruanui event, and to consider what processes influence the state of the modern volcano. The post-Oruanui dacites reflect the first products of the rebuilding silicic magma system, as most of the Oruanui mush was reconfigured or significantly modified in composition following thermal fluxing accompanying post-caldera collapse readjustment. Compositional variations within the younger rhyolites at priming of the silicic mush occurred multiple controls on the timing of eruptions, and demonstrate how the magmatic system can rapidly change behavior to generate large eruptible melt bodies on timescales of direct relevance to humans and monitoring initiatives.

  4. Thin film surface processing by ultrashort laser pulses (USLP)

    Science.gov (United States)

    Scorticati, D.; Skolski, J. Z. P.; Römer, G. R. B. E.; Huis in't Veld, A. J.; Workum, M.; Theelen, M.; Zeman, M.

    2012-06-01

    In this work, we studied the feasibility of surface texturing of thin molybdenum layers on a borosilicate glass substrate with Ultra-Short Laser Pulses (USLP). Large areas of regular diffraction gratings were produced consisting of Laserinduced periodic surface structures (LIPSS). A short pulsed laser source (230 fs-10 ps) was applied using a focused Gaussian beam profile (15-30 μm). Laser parameters such as fluence, overlap (OL) and Overscans (OS), repetition frequency (100-200 kHz), wavelength (1030 nm, 515 nm and 343 nm) and polarization were varied to study the effect on periodicity, height and especially regularity of LIPSS obtained in layers of different thicknesses (150-400 nm). The aim was to produce these structures without cracking the metal layer and with as little ablation as possible. It was found that USLP are suitable to reach high power densities at the surface of the thin layers, avoiding mechanical stresses, cracking and delamination. A possible photovoltaic (PV) application could be found in texturing of thin film cells to enhance light trapping mechanisms.

  5. Changing Energy Inputs at Earth's Surface Translates to Differences in Water Availability, Weathering Rates, and Biotic Activity at Depth

    Science.gov (United States)

    McIntosh, J. C.; Zapata-Rios, X.; Rasmussen, C.; Brooks, P. D.; Gallery, R. E.; Pelletier, J. D.; Chorover, J.

    2016-12-01

    The Critical Zone (CZ), the thin skin of the Earth, from the top of canopies down to saturated bedrock, provides vital environmental and human services, including water storage, elemental cycling and climate regulation. CZ structure develops over both long (geologic) timescales in response to variations in water, energy and carbon availability, or short (episodic) timescales due to disturbance, such as fire and land use change. This structural heterogeneity in turn mediates dissipative products of CZ development altering water and solute fluxes, transit times and flowpaths. Understanding how these coupled process control CZ evolution across timescales is one of the grand challenges for CZ science. Here, we investigate how microclimate and hydrologic fluxes related to aspect and landscape position influence CZ structure and function across time scales in seasonally water-limited montane catchments. We show how CZ topographic structure interacts with climate change and associated disturbance to control inputs of water, energy and carbon into the CZ, which translates to differences in water availability, weathering rates, and biotic activity at depth. Beyond temporal and elevational trends in climatic forcing, we observe strong impacts of aspect variation on biological productivity in water-limited systems, largely because of the aspect induced diurnal covariation of solar radiation with temperature, that increases potential ET on S- or W-facing slopes relative to N- or E-facing slopes. This directly impacts the amount of water, carbon and energy available for subsurface weathering, leading to deeper regolith on N- and E-facing slopes. Consequently, we see longer water transit times and greater weathering fluxes in N-facing slopes. Higher weathering fluxes and microbial activity are also seen in convergent areas characterized by higher values of topographic wetness index, due to greater lateral fluxes of water and DOC. In so far as CZ evolution depends on meteorologic

  6. Surface Distresses Detection of Pavement Based on Digital Image Processing

    OpenAIRE

    Ouyang, Aiguo; Luo, Chagen; Zhou, Chao

    2010-01-01

    International audience; Pavement crack is the main form of early diseases of pavement. The use of digital photography to record pavement images and subsequent crack detection and classification has undergone continuous improvements over the past decade. Digital image processing has been applied to detect the pavement crack for its advantages of large amount of information and automatic detection. The applications of digital image processing in pavement crack detection, distresses classificati...

  7. Facile preparation of self-healing superhydrophobic CeO2 surface by electrochemical processes

    Science.gov (United States)

    Nakayama, Katsutoshi; Hiraga, Takuya; Zhu, Chunyu; Tsuji, Etsushi; Aoki, Yoshitaka; Habazaki, Hiroki

    2017-11-01

    Herein we report simple electrochemical processes to fabricate a self-healing superhydrophobic CeO2 coating on Type 304 stainless steel. The CeO2 surface anodically deposited on flat stainless steel surface is hydrophilic, although high temperature-sintered and sputter-deposited CeO2 surface was reported to be hydrophobic. The anodically deposited hydrophilic CeO2 surface is transformed to hydrophobic during air exposure. Specific accumulation of contaminant hydrocarbon on the CeO2 surface is responsible for the transformation to hydrophobic state. The deposition of CeO2 on hierarchically rough stainless steel surface produces superhydrophobic CeO2 surface, which also shows self-healing ability; the surface changes to superhydrophilic after oxygen plasma treatment but superhydrophobic state is recovered repeatedly by air exposure. This work provides a facile method for preparing a self-healing superhydrophobic surface using practical electrochemical processes.

  8. Improvement in Surface Characterisitcs of Polymers for Subsequent Electroless Plating Using Liquid Assisted Laser Processing

    DEFF Research Database (Denmark)

    Marla, Deepak; Zhang, Yang; Jabbaribehnam, Mirmasoud

    2016-01-01

    Metallization of polymers is a widely used process in the electronic industry that involves their surface modification as a pre-treatment step. Laser-based surface modification is one of the commonly used techniques for polymers due to its speed and precision. The process involves laser heating...... of the polymer surface to generate a rough or porous surface. Laser processing in liquid generates superior surface characteristics that result in better metal deposition. In this study, a comparison of the surface characteristics obtained by laser processing in water vis-à-vis air along with the deposition...... characteristics are presented. In addition, a numerical model based on the finite volume method is developed to predict the temperature profile during the process. Based on the model results, it is hypothesized that physical phenomena such as vapor bubble generation and plasma formation may occur in the presence...

  9. Coupling between Earth Surface and Ionosphere before Earthquakes: Positive Air Ionization at the Ground-to-Air Interface as Major Driving Mechanism

    Science.gov (United States)

    Roberts, L. E.; Freund, F. T.

    2012-12-01

    When positive holes, h^{bullet}, stress-activated deep below, arrive at Earth's surface, they establish microscopic E fields that eventually become strong enough to (i) field-ionize air molecules and (ii) trigger tiny corona discharges. The injection of positive airborne ions will have a number of predictable consequences: Due to electrostatic repulsion among the positive ions, the ionized air volume will expand upward. Acting as condensation nuclei for water droplets, ion-laden air will lead to haze/fog/cloud formation. Dragging along the ground potential, ion-laden air will change the vertical E field. Ionospheric plasma will polarize with electrons being pulled down. Positive ions at the top of stratosphere will be accelerated upward in prevailing E field. With decreasing air pressure, vertical ion current will accelerate. Electrons in the ionosphere will respond, moving downward with the same speed, leading to a Doppler shift experienced by radio waves reflected off the ionosphere. Due to magnetohydrodynamic coupling, an initially homogeneous vertical ion current will break up into bubbles of higher and lower ion densities. E fields will develop in the mesosphere, possibly to the point of triggering lightning very short lightning strikes, similar to sprites, but randomly oriented. Bubbles of higher and lower ion densities in the mesosphere will lead to bumps in the ionosphere's E field, which satellites record as apparent turbulences. This process only applies to situations where the air at ground level becomes positively ionized. When ionization switches to tiny corona discharges, the air will have roughly equal numbers of positive and negative ions. As a result, the selective upward current of positive air ions will fade away along with the predicted phenomena such as ionospheric TEC anomalies, Doppler shift and ionospheric E field turbulences.; Figure: Positive air ionization at ground level. The rise of positive ion-laden air leads to anomalies in the Total

  10. The Development of Two Science Investigator-led Processing Systems (SIPS) for NASA's Earth Observation System (EOS)

    Science.gov (United States)

    Tilmes, Curt

    2004-01-01

    In 2001, NASA Goddard Space Flight Center's Laboratory for Terrestrial Physics started the construction of a science Investigator-led Processing System (SIPS) for processing data from the Ozone Monitoring Instrument (OMI) which will launch on the Aura platform in mid 2004. The Ozone Monitoring Instrument (OMI) is a contribution of the Netherlands Agency for Aerospace Programs (NIVR) in collaboration with the Finnish Meteorological Institute (FMI) to the Earth Observing System (EOS) Aura mission. It will continue the Total Ozone Monitoring System (TOMS) record for total ozone and other atmospheric parameters related to ozone chemistry and climate. OMI measurements will be highly synergistic with the other instruments on the EOS Aura platform. The LTP previously developed the Moderate Resolution Imaging Spectrometer (MODIS) Data Processing System (MODAPS), which has been in full operations since the launches of the Terra and Aqua spacecrafts in December, 1999 and May, 2002 respectively. During that time, it has continually evolved to better support the needs of the MODIS team. We now run multiple instances of the system managing faster than real time reprocessings of the data as well as continuing forward processing. The new OMI Data Processing System (OMIDAPS) was adapted from the MODAPS. It will ingest raw data from the satellite ground station and process it to produce calibrated, geolocated higher level data products. These data products will be transmitted to the Goddard Distributed Active Archive Center (GDAAC) instance of the Earth Observing System (EOS) Data and Information System (EOSDIS) for long term archive and distribution to the public. The OMIDAPS will also provide data distribution to the OMI Science Team for quality assessment, algorithm improvement, calibration, etc. We have taken advantage of lessons learned from the MODIS experience and software already developed for MODIS. We made some changes in the hardware system organization, database and

  11. Evaluating and improving hydrologic processes in the community land model for integrated earth system modeling

    Science.gov (United States)

    Hannah, D. M.; Khamis, K.; Blaen, P. J.; Hainie, S.; Mellor, C.; Brown, L. E.; Milner, A. M.

    2011-12-01

    High climatic sensitivity and low anthropogenic influence make glacierized river basins important environments for examining hydrological and ecological response to global change. This paper synthesises findings from previous and ongoing research in glacierized Alpine and Arctic river basins (located in the French Pyrenees, New Zealand, Swedish Lapland and Svalbard), which adopts an interdisciplinary approach to investigate the climate-cryosphere-hydrology-ecology cascade. Data are used to advance hypotheses concerning the consequences of climate change/ variability on glacier river system hydrology and ecology. Aquatic ecosystems in high latitude and altitude environments are influenced strongly by cryospheric and hydrological processes due to links between atmospheric forcing, snowpack/ glacier mass-balance, river runoff, physico-chemistry and biota. In the current phase of global warming, many glaciers are retreating. Using downscaled regional climate projections as inputs to a distributed hydrological model for a study basin in the French Pyrenees (i.e. an environment at the contemporary limit of valley glaciation), we show how shrinking snow and ice-masses may alter space-time dynamics in basin runoff. Notably, the timing of peak snow- and ice-melt may shift; and the proportion of stream flow sourced from rainfall-runoff (cf. meltwater) may increase. Across our range of Alpine and Arctic study basins, we quantify observed links between relative water source contributions (% meltwater : % groundwater), physico-chemical habitat (e.g. water temperature, electrical conductivity, suspended sediment and channel stability) and benthic communities. At the site scale, results point towards increased community diversity (taxonomic and functional) as meltwater contributions decline and physico-chemical habitat becomes less harsh. However, basin-scale biodiversity may be reduced due to less spatio-temporal heterogeneity in water source contributions and habitats, and the

  12. An analytical solution for the elastic response to surface loads imposed on a layered, transversely isotropic and self-gravitating Earth

    DEFF Research Database (Denmark)

    Pan, E.; Chen, J.Y.; Bevis, M.

    2015-01-01

    We present an analytical solution for the elastic deformation of an elastic, transversely isotropic, layered and self-gravitating Earth by surface loads. We first introduce the vector spherical harmonics to express the physical quantities in the layered Earth. This reduces the governing equations...... to a linear system of equations for the expansion coefficients. We then solve for the expansion coefficients analytically under the assumption (i.e. approximation) that in the mantle, the density in each layer varies as 1/r (where r is the radial coordinate) while the gravity is constant and that in the core...... the gravity in each layer varies linearly in r with constant density. These approximations dramatically simplify the subsequent mathematical analysis and render closed-form expressions for the expansion coefficients. We implement our solution in a MATLAB code and perform a benchmark which shows both...

  13. Microwave Processing of Planetary Surfaces for Volatile Extraction

    Science.gov (United States)

    Ethridge, Edwin C.; Kaukler, William

    2011-01-01

    In-Situ Resource Utilization will be necessary for sustained exploration of space. Volatiles are present in planetary soils, but water by far has the strongest potential for effective utilization. The presence of water at the lunar poles, Mars, and possibly on Phobos opens the possibility of producing LOX for propellant. Water is also a useful radiation shielding material and water (and oxygen) are expendables that are also required for habitation in space. Because of the strong function of water vapor pressure with temperature, heating soil effectively liberates water vapor by sublimation. Microwave energy will penetrate soil and heat from within much more efficiently than heating from the surface with radiant heat. This is especially true under vacuum conditions since the heat transfer rate is very low. The depth of microwave penetration is a strong function of the microwave frequency and to a lesser extent on soil dielectric properties. Methods for measuring the complex electric permittivity and magnetic permeability are being developed and have been measured for some lunar soil simulants at 0.5, 2.45, and 10 GHz from room temperature down to liquid nitrogen temperature. A new method for delivery of microwaves deep into a planetary surface is being prototyped with laboratory experiments and modeled with COMSOL MultiPhysics. We have plans to set up a planetary testbed in a large vacuum chamber in the coming year. Recent results will be presented.

  14. Microstructural and hardness gradients in Cu processed by high pressure surface rolling

    DEFF Research Database (Denmark)

    He, Q. Y.; Zhu, X.-M.; Mei, Q. S.

    2017-01-01

    in the topmost surface to the microscale in the bulk. The hardness varies from 1.37 GPa at the topmost surface to about 0.6 GPa in the coarse-grained matrix. The results of the investigation demonstrate that the HPSR process shows good potential for the generation of thick gradient microstructures on the surface...

  15. Monte Carlo simulations of the secondary neutron ambient and effective dose equivalent rates from surface to suborbital altitudes and low Earth orbit.

    Science.gov (United States)

    El-Jaby, Samy; Richardson, Richard B

    2015-07-01

    Occupational exposures from ionizing radiation are currently regulated for airline travel (Earth orbit (∼300-400 km). Aircrew typically receive between 1 and 6 mSv of occupational dose annually, while aboard the International Space Station, the area radiation dose equivalent measured over just 168 days was 106 mSv at solar minimum conditions. It is anticipated that space tourism vehicles will reach suborbital altitudes of approximately 100 km and, therefore, the annual occupational dose to flight crew during repeated transits is expected to fall somewhere between those observed for aircrew and astronauts. Unfortunately, measurements of the radiation environment at the high altitudes reached by suborbital vehicles are sparse, and modelling efforts have been similarly limited. In this paper, preliminary MCNPX radiation transport code simulations are developed of the secondary neutron flux profile in air from surface altitudes up to low Earth orbit at solar minimum conditions and excluding the effects of spacecraft shielding. These secondary neutrons are produced by galactic cosmic radiation interacting with Earth's atmosphere and are among the sources of radiation that can pose a health risk. Associated estimates of the operational neutron ambient dose equivalent, used for radiation protection purposes, and the neutron effective dose equivalent that is typically used for estimates of stochastic health risks, are provided in air. Simulations show that the neutron radiation dose rates received at suborbital altitudes are comparable to those experienced by aircrew flying at 7 to 14 km. We also show that the total neutron dose rate tails off beyond the Pfotzer maximum on ascension from surface up to low Earth orbit. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  16. Fermi surface investigations of the alkaline-earth-metal subnitride NaBa3N by means of de Haas-van Alphen oscillations

    Science.gov (United States)

    Weiss, H.; Vajenine, G. V.; Steinbrenner, U.; Simon, A.; Balthes, E.; Wyder, P.

    2001-03-01

    de Haas-van Alphen oscillations are observed in the alkaline-earth-metal subnitride NaBa3N. They are studied at various sample orientations with respect to the magnetic-field direction. A rich spectrum of quantum oscillation frequencies varying with the field orientation is found. The effective cyclotron masses of the carriers are found to depend on the area enclosed by the corresponding Fermi surface orbit, while the mean free path is constant over the whole Fermi surface. Four of the detected frequencies are attributed to two lens-shaped features of the Fermi surface, as computed with the tight-binding linear muffin-tin orbital method. Spin-orbit coupling is shown to play a crucial role in determining the topology of the respective orbits in reciprocal space. The experimental results and the computed electronic structure are discussed with regard to the void metal model for the subnitride.

  17. Surface light scattering: integrated technology and signal processing

    DEFF Research Database (Denmark)

    Lading, L.; Dam-Hansen, C.; Rasmussen, E.

    1997-01-01

    systems representing increasing levels of integration are considered. It is demonstrated that efficient signal and data processing can be achieved by evaluation of the statistics of the derivative of the instantaneous phase of the detector signal. (C) 1997 Optical Society of America....

  18. Nano surface generation of grinding process using carbon nano tubes

    Indian Academy of Sciences (India)

    Pour point-temperature at which the rate of flow will stop. 2.4 Selection of work piece and ... gaps and coolant flow rate should be selected for efficient in-process dressing. Normally arc- shaped electrodes are ... AFM (figure 4). The technique for measuring these forces is called lateral force, or frictional force microscopy.

  19. Application of response surface methodology in process parameters ...

    African Journals Online (AJOL)

    Adverse effect of the highly biorecalcitrant compound phenol to the environment is well established and its concentrations in industrial effluents vary greatly from 2.8 to 6,800 mg/l depending on the source. Fenton process effectively mineralises to CO2 and H2O but reported works consumed more reagents and require ...

  20. Coronal Structures as Tracers of Sub-Surface Processes

    Indian Academy of Sciences (India)

    tribpo

    Abstract. The solar corona - one of the most spectacular celestial shows and yet one of the most challenging puzzles - exhibits a spectrum of structures related to both the quiet Sun and active regions. In spite of dramatic differences in appearance and physical processes, all these structures share a common origin: they are ...

  1. Coronal Structures as Tracers of Sub-Surface Processes

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... The solar corona - one of the most spectacular celestial shows and yet one of the most challenging puzzles - exhibits a spectrum of structures related to both the quiet Sun and active regions. In spite of dramatic differences in appearance and physical processes, all these structures share a common origin: ...

  2. Processing and properties of electrodeposited layered surface coatings

    DEFF Research Database (Denmark)

    Horsewell, Andy

    1998-01-01

    Hard chromium, produced by conventional dir ect curl ent (DC) electrodeposition, cannot be deposited to thicknesses gl enter than about 5 mu m because of the buildup of processing stresses which cause channel cracks in the coating. Much thicker chromium coatings map be produced by depositing a la...

  3. Dunes on Titan: A major landform revealing atmospheric and surface processes

    Science.gov (United States)

    Radebaugh, Jani; Lorenz, Ralph; Arnold, Karl; Savage, Christopher; Williams, Brigitte

    The surface of Saturn’s moon Titan is covered in features that herald an active atmosphere and perhaps interior, such as dunes, rivers, lakes, mountain chains, and possible cryovolcanoes. Examining the geomorphology of these features helps us approach an understanding of the processes that are occurring or have occurred in the atmosphere and subsurface. A major landform on Titan is dunes, composed of organic sands ultimately derived from upper atmospheric processing of methane, subsequently perhaps eroded from organic sedimentary layers by methane rainfall and fluvial flow. Dunes fill vast fields, termed sand seas, similar to those observed in the Sahara, Namibia, and the Arabian peninsula. The equatorial region of Titan contains five separate sand seas as observed by the Cassini Synthetic Aperture Radar (SAR), Imaging Science Subsystem (ISS) and Visual and Infrared Mapping Spectrometer (VIMS) instruments. Together these sand seas cover 14 percent of the surface, totaling 12 million km2, and each have areas on the scale of the Saharan Great Sand Sea. They adjoin each other through sediment pathways around landmasses, and these large-scale connections as well as individual dune interactions with topography indicate a general transport of sediment from west to east. Measurements of dune height, width and spacing in Cassini SAR images reveal all of Titan’s thousands of linear dunes are of the same population. This indicates there was general uniformity in the wind and sediment supply conditions that led to the current dune forms. Variations in the parametric values result from deviations from these conditions, in some locations where elevated terrains have deflected winds. Dunes and sand seas are among the stratigraphically youngest features on Titan, showing little evidence of being affected by impact cratering or fluvial flow. However, individual dunes may be relatively stable, as the reorganization time scale for these features on Earth can be tens to hundreds

  4. Microstructure and optical appearance of anodized friction stir processed Al - Metal oxide surface composites

    DEFF Research Database (Denmark)

    Gudla, Visweswara Chakravarthy; Jensen, Flemming; Bordo, Kirill

    2014-01-01

    Multiple-pass friction stir processing (FSP) was employed to impregnate Ti, Y and Ce oxide powders into the surface of an Aluminium alloy. The FSP processed surface composite was subsequently anodized with an aim to develop optical effects in the anodized layer owing to the presence of incorporated...... process. The effect of anodizing parameters on the optical appearance of the anodized surface was studied. Characterization was performed using FIB-SEM and TEM. The surface appearance was analysed using spectrophotometry technique which measures the diffuse and total reflectance of the surface....... The appearance of the anodized surface changed from dark to bright upon increasing the anodizing voltage. Particles in the FSP zone were partially or completely modified during the anodizing process and modified the morphology of the surrounding anodized Al matrix which has a clear influence on the mechanism...

  5. Surface conductivity dependent dynamic behaviour of an ultrafine atmospheric pressure plasma jet for microscale surface processing

    Energy Technology Data Exchange (ETDEWEB)

    Abuzairi, Tomy [Graduate School of Science and Technology, Shizuoka University, Hamamatsu 432-8561 (Japan); Department of Electrical Engineering, Faculty of Engineering, Universitas Indonesia, Depok 16424 (Indonesia); Okada, Mitsuru [Department of Engineering, Shizuoka University, Hamamatsu 432-8561 (Japan); Bhattacharjee, Sudeep [Department of Physics, Indian Institute of Technology, Kanpur 208016 (India); Nagatsu, Masaaki, E-mail: nagatsu.masaaki@shizuoka.ac.jp [Graduate School of Science and Technology, Shizuoka University, Hamamatsu 432-8561 (Japan); Department of Engineering, Shizuoka University, Hamamatsu 432-8561 (Japan); Research Institute of Electronics, Shizuoka University, Hamamatsu 432-8561 (Japan)

    2016-12-30

    Highlights: • Spatio-temporal behaviors of capillary APPJs are studied for various substrates. • Plasma irradiation area depended on the substrate conductivity and permittivity. • Surface irradiation area was significantly broadened in polymer-like substrate. • Effect of applying a substrate bias on the APPJ irradiation area was investigated. - Abstract: An experimental study on the dynamic behaviour of microcapillary atmospheric pressure plasma jets (APPJs) with 5 μm tip size for surfaces of different conductivity is reported. Electrical and spatio-temporal characteristics of the APPJs are monitored using high voltage probe, current monitor and high speed intensified charge couple device camera. From these experimental results, we presented a simple model to understand the electrical discharge characteristics of the capillary APPJs with double electrodes, and estimated the velocity of the ionization fronts in the jet and the electron density to be 3.5–4.2 km/s and 2–7 × 10{sup 17} m{sup −3}. By analyzing the dynamics of the microcapillary APPJs for different substrate materials, it was found that the surface irradiation area strongly depended on the substrate conductivity and permittivity, especially in the case of polymer-like substrate, surface irradiation area was significantly broadened probably due to the repelling behaviour of the plasma jets from the accumulated electrical charges on the polymer surface. The effect of applying a substrate bias in the range from −900 V to +900 V on the plasma irradiation onto the substrates was also investigated. From the knowledge of the present results, it is helpful for choosing the substrate materials for microscale surface modification.

  6. Tribological investigations of the applicability of surface functionalization for dry extrusion processes

    Science.gov (United States)

    Teller, Marco; Prünte, Stephan; Ross, Ingo; Temmler, André; Schneider, Jochen M.; Hirt, Gerhard

    2017-10-01

    Cold extrusion processes are characterized by large relative contact stresses combined with a severe surface enlargement of the workpiece. Under these process conditions a high risk for galling of workpiece material to the tool steel occurs especially in processing of aluminum and aluminum alloys. In order to reduce adhesive wear lubricants for separation of workpiece and tool surfaces are used. As a consequence additional process steps (e.g. preparation and cleaning of workpieces) are necessary. Thus, the realization of a dry forming process is aspired from an environmental and economic perspective. In this paper a surface functionalization with self-assembled-monolayers (SAM) of the tool steels AISI D2 (DIN 1.2379) and AISI H11 (DIN 1.2343) is evaluated by a process-oriented tribological test. The tribological experiment is able to resemble and scale the process conditions of cold extrusion related to relative contact stress and surface enlargement for the forming of pure aluminum (Al99.5). The effect of reduced relative contact stress, surface enlargement and relative velocity on adhesive wear and tool lifetime is evaluated. Similar process conditions are achievable by different die designs with decreased extrusion ratios and adjusted die angles. The effect of surface functionalization critically depends on the substrate material. The different microstructure and the resulting differences in surface chemistry of the two tested tool steels appear to affect the performance of the tool surface functionalization with SAM.

  7. Platonic Plate Tectonics: On the Regularity of the Distribution of ’Triple Points’ on the Earth’s Surface.

    Science.gov (United States)

    1981-11-01

    7 ADA113 777 PRINCETON UNIV NJ DEPT OF STATISTICS F/S 8/7PLATONIC PLATE TECTONICS : ON THE REGULARITY OF THE DISTRIBUTION--ETC(U) NOV Si A J ARNOLD...PERIOD COVEREO Platonic Plate Tectonics : On the Regularity of. Technical I the Distribution of "Triple Points’ on the Earths Suface6 PERF004MING...Unannounced fl Justiffication .- By- Distributjon/ Availability Codes Avail and/or___ Dit Special oric\\ PLATONIC PLATE TECTONICS : ON THE REGULARITY OF

  8. Development of sustainable paper coatings using nanoscale industrial surface processing

    DEFF Research Database (Denmark)

    Markert, Frank; Breedveld, Leo; Lahti, Johanna

    The term “sustainable production” comprises a weighting of economical, environmental and social considerations. The three categories are mutually dependent and therefore an assessment needs to take a systems analysis approach to make the right decisions by the various stakeholders ranging from....... The paper will provide some insights of this approach presenting some first results of the project describing the used processes and substances, safety and occupational health issues, consideration of nanomaterial safety, and the communication of safety issues to the public....

  9. Influence of the surface layer characteristics on the regularities of the cutting process

    Directory of Open Access Journals (Sweden)

    Krainev Dmitriy V.

    2017-01-01

    Full Text Available The article considers the influence of the surface layer characteristics on the regularities of the cutting process and the formation of the quality of the surface machined. This effect has been confirmed by the study results of the combined cutting method with advanced plastic deformation (APD. The work estimates the impact of the change in the surface layer properties on the forces and temperature of cutting, stability of the chip formation and quality parameters of the surface machined.

  10. The Impact of the Spectral Band Number and Width on the Oil Pollution Diagnostics on Earth Surface by Laser Fluorescence Method

    Directory of Open Access Journals (Sweden)

    Yu. V. Fedotov

    2017-01-01

    Full Text Available Using the remote sensing methods is the most promising for day-to-day control of oil pollution. The laser-induced fluorescence method provides efficient detection and classification of oil pollutions. To monitor oil pollutions on the earth surface is more complicated than on the water one because of lower fluorescence intensity and interfering fluorescence of natural objects available on the earth surface.Properties of oil pollution classifiers depend largely on the number and positions of spectral bands of fluorescence registration. Reducing the number of spectral bands allows us to diminish computation complexity and cost of equipment. In some cases the reduction increases classification accuracy. The number of spectral bands can be reduced through increasing their width.The paper presents mathematical modeling of oil pollution detection and classification. The experimentally obtained fluorescence spectra of oil pollutions on different substrates were used as input data. The k-nearest neighbors algorithm was used to detect and classify oil pollutions. Cross validation was applied in mathematical modeling.The mathematical modeling results have shown that for oil pollutions detection using over 8 spectral bands (band width less than 50 nm a classification error rate does not depend on the further increasing number of the spectral bands.As to the type classification of oil pollutions (4 classes, an increasing width of the spectral bands up to 60 nm (the number of spectral bands reduced up 7 does not lead to a significantly decreasing overall classification accuracy.In the case of the sort classification of oil pollutions (8 classes a local maximum of the overall accuracy has been observed at 25-30 nm width of the spectral band (14-16 spectral bands. The spectral resolution improvement (increasing the number of bands does give an essentially increasing accuracy.The paper has shown that to detect and classify oil pollutions on the earth surface

  11. Modification of peptide by surface-wave plasma processing

    Energy Technology Data Exchange (ETDEWEB)

    Motrescu, Iuliana [Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, 432-8561 (Japan); Faculty of Physics, Alexandru Ioan Cuza University, Bd. Carol I 11, 700506 Iasi (Romania); Ogino, Akihisa; Tanaka, Shigeyasu; Fujiwara, Taketomo; Kodani, Shinya; Kawagishi, Hirokazu [Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, 432-8561 (Japan); Popa, Gheorghe [Faculty of Physics, Alexandru Ioan Cuza University, Bd. Carol I 11, 700506 Iasi (Romania); Nagatsu, Masaaki, E-mail: tmnagat@ipc.shizuoka.ac.j [Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, 432-8561 (Japan)

    2010-04-30

    Fundamental research on the mechanisms of plasma-protein interactions is performed. The possibility of controlling the modification processes of peptides is investigated by changing gas species and treatment time. Changes of the peptide composition are analyzed by X-ray photoelectron spectroscopy using [Arg{sup 8}]-Vasotocin as peptide, under different discharge conditions. The XPS results show that the modifications depend on the discharging gas (such as argon, oxygen and nitrogen). Ultraviolet radiation emitted by the plasma contributes to the alteration of disulfide (S-S) bond in [Arg{sup 8}]-Vasotocin, which might be responsible for the loss of biological function.

  12. Numerical study of heating the upper atmosphere by acoustic-gravity waves from a local source on the Earth's surface and influence of this heating on the wave propagation conditions

    Science.gov (United States)

    Karpov, I. V.; Kshevetskii, S. P.

    2017-11-01

    The propagation of acoustic-gravity waves (AGW) from a source on the Earth's surface to the upper atmosphere is investigated with methods of mathematical modeling. The applied non-linear model of wave propagation in the atmosphere is based on numerical integration of a complete set of two-dimensional hydrodynamic equations. The source on the Earth's surface generates waves with frequencies near to the Brunt-Vaisala frequency. The results of simulation have revealed that some region of heating the atmosphere by propagated upward and dissipated AGWs arises above the source at altitudes nearby of 200 km. The horizontal scale of this heated region is about 1000 km in the case of the source that radiates AGWs during approximately 1 h. The appearing of the heated region has changed the conditions of AGW propagation in the atmosphere. When the heated region in the upper atmosphere has been formed, further a waveguide regime of propagation of waves with the periods shorter the Brunt-Vaisala period is realized. The upper boundary of the wave-guide coincides with the arisen heated region in the upper atmosphere. The considered mechanism of formation of large-scale disturbances in the upper atmosphere may be useful for explanation of connections of processes in the upper and lower atmospheric layers.

  13. Anthropogenic changes in the surface all-sky UV-B radiation through 1850–2005 simulated by an Earth system model

    OpenAIRE

    Yokohata, T.; Sudo, K; Takemura, T.; Watanabe, S.; Kawase, H.

    2012-01-01

    The historical anthropogenic change in the surface all-sky UV-B (solar ultraviolet: 280–315 nm) radiation through 1850–2005 is evaluated using an Earth system model. Responses of UV-B dose to anthropogenic changes in ozone and aerosols are separately evaluated using a series of historical simulations including/excluding these changes. Increases in these air pollutants cause reductions in UV-B transmittance, which occur gradually/rapidly before/after 1950 in and downwind of industrial a...

  14. Anthropogenic changes in the surface all-sky UV-B radiation through 1850–2005 simulated by an Earth system model

    OpenAIRE

    Watanabe, S.; Takemura, T.; Sudo, K; Yokohata, T.; Kawase, H.

    2012-01-01

    The historical anthropogenic change in the surface all-sky UV-B (solar ultraviolet: 280–315 nm) radiation through 1850–2005 is evaluated using an Earth system model. Responses of UV-B dose to anthropogenic changes in ozone and aerosols are separately evaluated using a series of historical simulations including/excluding these changes. Increases in these air pollutants cause reductions in UV-B transmittance, which occur gradually/rapidly before/after 1950 in and downwind of industrial and defo...

  15. Non-machined Surface Protection Process of Electrochemical Machining Based on Repaired Turbine Blade

    Directory of Open Access Journals (Sweden)

    LIU Wei-dong

    2016-11-01

    Full Text Available In order to improve the efficiency of turbine blade repairing, protection processes of non-machined surface in Electrochemical Machining (ECM based on blade repairing were studied. Mathematical model of electric field was developed to obtain current density distribution on anode surface, and to study the repairing principle and consequently analyze the defects forming mechanism by conventional electrolytic repair process. Sacrificial layer process was proposed to protect the non-machined surface in this work and an experimental system was developed to shape overlay welded TC4 blades. The results show that directly shaping process and insulated layer process produce stray dissolution and "stair" defects respectively,while sacrificial layer process achieves acceptable machining performance. With shaping time of 60s, the efficiency is improved; shaped blades have higher precision and surface roughness is Ra≤0.6μm, and with higher repeatability, the design requirements can be met.

  16. Optical monitoring of surface processes relevant to thin film growth by chemical vapour deposition Oxidation; Surface degradation

    CERN Document Server

    Simcock, M N

    2002-01-01

    This thesis reports on the investigation of the use of reflectance anisotropy spectroscopy (RAS) as an in-situ monitor for the preparation and oxidation of GaAs(100) c(4x4) surfaces using a CVD 2000 MOCVD reactor. These surfaces were oxidised using air. It was found that it was possible to follow surface degradation using RA transients at 2.6eV and 4eV. From this data it was possible to speculate on the nature of the surface oxidation process. A study was performed into the rate of surface degradation under different concentrations of air, it was found that the relation between the air concentration and the surface degradation was complicated but that the behaviour of the first third of the degradation approximated a first order behaviour. An estimation of the activation energy of the process was then made, and an assessment of the potential use of the glove-box for STM studies which is an integral part of the MOCVD equipment was also made. Following this, a description is given of the construction of an inte...

  17. Calcium-borosilicate glass-ceramics wasteforms to immobilize rare-earth oxide wastes from pyro-processing

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Miae [Department of Materials Science and Engineering and Division of Advanced Nuclear Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, 790-784 (Korea, Republic of); Heo, Jong, E-mail: jheo@postech.ac.kr [Department of Materials Science and Engineering and Division of Advanced Nuclear Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, 790-784 (Korea, Republic of); Department of Materials Engineering, Adama Science and Technology University (ASTU), PO Box 1888, Adama (Ethiopia)

    2015-12-15

    Glass-ceramics containing calcium neodymium(cerium) oxide silicate [Ca{sub 2}Nd{sub 8-x}Ce{sub x}(SiO{sub 4}){sub 6}O{sub 2}] crystals were fabricated for the immobilization of radioactive wastes that contain large portions of rare-earth ions. Controlled crystallization of alkali borosilicate glasses by heating at T ≥ 750 °C for 3 h formed hexagonal Ca–silicate crystals. Maximum lanthanide oxide waste loading was >26.8 wt.%. Ce and Nd ions were highly partitioned inside Ca–silicate crystals compared to the glass matrix; the rare-earth wastes are efficiently immobilized inside the crystalline phases. The concentrations of Ce and Nd ions released in a material characterization center-type 1 test were below the detection limit (0.1 ppb) of inductively coupled plasma mass spectroscopy. Normalized release values performed by a product consistency test were 2.64·10{sup −6} g m{sup −2} for Ce ion and 2.19·10{sup −6} g m{sup −2} for Nd ion. Results suggest that glass-ceramics containing calcium neodymium(cerium) silicate crystals are good candidate wasteforms for immobilization of lanthanide wastes generated by pyro-processing. - Highlights: • Glass-ceramic wasteforms containing Ca{sub 2}Nd{sub 8-x}Ce{sub x}(SiO{sub 4}){sub 6}O{sub 2} crystals were synthesized to immobilize lanthanide wastes. • Maximum lanthanide oxide waste loading was >26.8 wt.%. • Ce and Nd ions were highly partitioned inside Ca–Nd–silicate crystals compared to glass matrix. • Amounts of Ce and Nd ions released in the material characterization center-type 1 were below the detection limit (0.1 ppb). • Normalized release values performed by a PCT were 2.64• 10{sup −6} g m{sup −2} for Ce ions and 2.19• 10{sup −6} g m{sup −2} for Nd ions.

  18. Particle Engineering in Pharmaceutical Solids Processing: Surface Energy 
Considerations

    Science.gov (United States)

    Williams, Daryl R.

    2015-01-01

    During the past 10 years particle engineering in the pharmaceutical industry has become a topic of increasing importance. Engineers and pharmacists need to understand and control a range of key unit manufacturing operations such as milling, granulation, crystallisation, powder mixing and dry powder inhaled drugs which can be very challenging. It has now become very clear that in many of these particle processing operations, the surface energy of the starting, intermediate or final products is a key factor in understanding the processing operation and or the final product performance. This review will consider the surface energy and surface energy heterogeneity of crystalline solids, methods for the measurement of surface energy, effects of milling on powder surface energy, adhesion and cohesion on powder mixtures, crystal habits and surface energy, surface energy and powder granulation processes, performance of DPI systems and finally crystallisation conditions and surface energy. This review will conclude that the importance of surface energy as a significant factor in understanding the performance of many particulate pharmaceutical products and processes has now been clearly established. It is still nevertheless, work in progress both in terms of development of methods and establishing the limits for when surface energy is the key variable of relevance. PMID:25876912

  19. A new method of on-line turned surface monitoring by digital image processing

    Directory of Open Access Journals (Sweden)

    Mai Qingqun

    2016-01-01

    Full Text Available A machined surface can be seen as a replica of the geometric outline of the cutting tool nose during the process of cylindrical turning, and the texture of the machined surface varies along with the tool wear. A new method of on-line turned surface monitoring is proposed in this paper by studying the grey value characteristics of the turned surface digital image. The regularity of the surface image is judged and analysed by using wavelet transform, fractal analysis, and discreteness analysis of the wavelength of the texture contour. The average wave contour, which can reflect processing state and the condition of the turned surface, is extracted from the regular texture image. Experimental results show that the turned surface condition can be monitored on-line effectively with the presented method.

  20. The Lifeworld Earth and a Modelled Earth

    Science.gov (United States)

    Juuti, Kalle

    2014-01-01

    The goal of this paper is to study the question of whether a phenomenological view of the Earth could be empirically endorsed. The phenomenological way of thinking considers the Earth as a material entity, but not as an object as viewed in science. In the learning science tradition, tracking the process of the conceptual change of the shape of the…

  1. Study of the processes of adsorption of amine-containing surface-active substance on the surface of Aluminum powder

    Directory of Open Access Journals (Sweden)

    Antonina Dyuryagina

    2012-03-01

    Full Text Available Equilibrium characteristics of adsorption on a surface of a pigment depending on concentration factors and temperature of the dispersive environment are defined. Kinetic laws of superficial activity of binary, threefold homogeneous and heterogeneous modeling systems are studied. The estimation of mechanisms of process of adsorption is carried out.

  2. Effect of surface related organic vibrational modes in luminescent upconversion dynamics of rare earth ions doped nanoparticles

    NARCIS (Netherlands)

    Wang, Y.; Smolarek, S.; Kong, X.; Buma, W.J.; Brouwer, A.M.; Zhang, H.

    2010-01-01

    Physical and chemical properties of nanoparticles are known to be subject to the surface factors. For their biological/biomedical applications, typically, surface of the nanoparticles has to be modified which inevitably affects their performance. In this work we have studied the interaction between

  3. Cyclic variations in the Earth's flattening and questions of seismotectonics

    Science.gov (United States)

    Levin, B. W.; Sasorova, E. V.; Steblov, G. M.; Domanskii, A. V.; Prytkov, A. S.; Tsyba, E. N.

    2017-07-01

    For more than a decade, the global network of GPS stations whose measurements are part of the International GPS Service (IGS) have been recording cyclic variations in the radius vector of the geodetic ellipsoid with a period of one year and amplitude of 10 mm. The analysis of the figure of the Earth carried out by us shows that the observed variations in the vertical component of the Earth's surface displacements can induce small changes in the flattening of the Earth's figure which are, in turn, caused by the instability of the Earth's rotation. The variations in the angular velocity and flattening of the Earth change the kinetic energy of the Earth's rotation. The additional energy is 1021 J. The emerging variations in the flattening of the Earth's ellipsoid lead to changes in the surface area of the Earth's figure, cause the development of deformations in rocks, accumulation of damage, activation of seismotectonic processes, and preparation of earthquakes. It is shown that earthquakes can be caused by the instability of the Earth's rotation which induces pulsations in the shape of the Earth and leads to the development of alternating-sign deformations in the Earth's solid shell.

  4. Erosion and deposition processes in surface granular flows

    Science.gov (United States)

    Trinh, T.; Boltenhagen, P.; Delannay, R.; Valance, A.

    2017-10-01

    We report on experiments aiming at characterizing erosion and deposition processes on a tilted granular bed. We investigate the existence of the neutral angle, that is, the critical angle at which erosion exactly balances accretion after the passage of a granular avalanche of a finite mass. Experiments show in particular that the neutral angle depends on both avalanche mass and shape but is rather insensitive to the bed length. This result strongly suggests that the effective friction between the static and mobile granular phases cannot be taken as an intrinsic property that is only material dependent but should be considered a flow-dependent property. Interestingly, for a given avalanche mass, the net erosion rate increases linearly with the angular deviation from the neutral angle. We also compare our data with the predictions of the erosion-deposition model introduced by Bouchaud, Cates, Ravi Prakash, and Edwards (BCRE) [J. Phys. I 4, 1283 (1994), 10.1051/jp1:1994195]. We show that the predictions drawn from the modified version of the BCRE model proposed by Boutreux and de Gennes, in which the local erosion rate between the static and mobile phases is independent of the flow thickness, are in remarkable agreement with the experimental results.

  5. Superhydrophobic aluminum alloy surfaces by a novel one-step process.

    Science.gov (United States)

    Saleema, N; Sarkar, D K; Paynter, R W; Chen, X-G

    2010-09-01

    A simple one-step process has been developed to render aluminum alloy surfaces superhydrophobic by immersing the aluminum alloy substrates in a solution containing NaOH and fluoroalkyl-silane (FAS-17) molecules. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and water contact angle measurements have been performed to characterize the morphological features, chemical composition and superhydrophobicity of the surfaces. The resulting surfaces provided a water contact angle as high as ∼162° and a contact angle hysteresis as low as ∼4°. The study indicates that it is possible to fabricate superhydrophobic aluminum surfaces easily and effectively without involving the traditional two-step processes.

  6. Electron microscope observations of impact crater debris amongst contaminating particulates on materials surfaces exposed in space in low-Earth orbit

    Science.gov (United States)

    Murr, L. E.; Rivas, J. M.; Quinones, S.; Niou, C.-S.; Advani, A. H.; Marquez, B.

    1993-01-01

    Debris particles extracted from a small sampling region on the leading edge of the Long Duration Exposure Facility (LDEF) spacecraft have been examined by analytical transmission electron microscopy and the elemental frequency observed by energy-dispersive X-ray spectrometry and compared with upper atmosphere (Earth) particle elemental frequency and the average elemental compositions of interplanetary dust particles. A much broader elemental distribution was observed for the exposed spacecraft surface debris milieu. Numerous metal microfragment analyses, particularly aluminum and stainless steel, were compared with scanning electron microscope observations-of impact crater features, and the corresponding elemental spectra on selected LDEF aluminium tray clamps and stainless steel bolts. The compositions and melt features for these impact craters and ejecta have been shown to be consistent with microcrystalline debris fragments in the case of aluminum, and these observations suggest an ever changing debris milieu on exposed surfaces for space craft and space system materials.

  7. Electron microscope observations of impact crater debris amongst contaminating particulates on materials surfaces exposed in space in low-Earth orbit

    Science.gov (United States)

    Murr, L. E.; Rivas, J. M.; Quinones, S.; Niou, C.-S.; Advani, A. H.; Marquez, B.

    1993-09-01

    Debris particles extracted from a small sampling region on the leading edge of the Long Duration Exposure Facility (LDEF) spacecraft have been examined by analytical transmission electron microscopy and the elemental frequency observed by energy-dispersive X-ray spectrometry and compared with upper atmosphere (Earth) particle elemental frequency and the average elemental compositions of interplanetary dust particles. A much broader elemental distribution was observed for the exposed spacecraft surface debris milieu. Numerous metal microfragment analyses, particularly aluminum and stainless steel, were compared with scanning electron microscope observations-of impact crater features, and the corresponding elemental spectra on selected LDEF aluminium tray clamps and stainless steel bolts. The compositions and melt features for these impact craters and ejecta have been shown to be consistent with microcrystalline debris fragments in the case of aluminum, and these observations suggest an ever changing debris milieu on exposed surfaces for space craft and space system materials.

  8. Earth Surface Deformation in the North China Plain Detected by Joint Analysis of GRACE and GPS Data

    Science.gov (United States)

    Liu, Renli; Li, Jiancheng; Fok, Hok Sum; Shum, C.K.; Li, Zhao

    2014-01-01

    Mass redistribution of the Earth causes variable loading that deforms the solid Earth. While most recent studies using geodetic techniques focus on regions (such as the Amazon basin and the Nepal Himalayas) with large seasonal deformation amplitudes on the order of 1–4 cm due to hydrologic loading, few such studies have been conducted on the regions where the seasonal deformation amplitude is half as large. Here, we use joint GPS and GRACE data to investigate the vertical deformation due to hydrologic loading in the North China Plain, where significant groundwater depletion has been reported. We found that the GPS- and GRACE-derived secular trends and seasonal signals are in good agreement, with an uplift magnitude of 1–2 mm/year and a correlation of 85.0%–98.5%, respectively. This uplift rate is consistent with groundwater depletion rate estimated from GRACE data and in-situ groundwater measurements from earlier report studies; whereas the seasonal hydrologic variation reflects human behavior of groundwater pumping for agriculture irrigation in spring, leading to less water storage in summer than that in the winter season. However, less than 20% of weighted root-mean-squared (WRMS) reductions were detected for all the selected GPS stations when GRACE-derived seasonal deformations were removed from detrended GPS height time series. This discrepancy is probably because the GRACE-derived seasonal signals are large-scale, while the GPS-derived signals are local point measurements. PMID:25340454

  9. Earth surface deformation in the North China Plain detected by joint analysis of GRACE and GPS data.

    Science.gov (United States)

    Liu, Renli; Li, Jiancheng; Fok, Hok Sum; Shum, C K; Li, Zhao

    2014-10-22

    Mass redistribution of the Earth causes variable loading that deforms the solid Earth. While most recent studies using geodetic techniques focus on regions (such as the Amazon basin and the Nepal Himalayas) with large seasonal deformation amplitudes on the order of 1-4 cm due to hydrologic loading, few such studies have been conducted on the regions where the seasonal deformation amplitude is half as large. Here, we use joint GPS and GRACE data to investigate the vertical deformation due to hydrologic loading in the North China Plain, where significant groundwater depletion has been reported. We found that the GPS- and GRACE-derived secular trends and seasonal signals are in good agreement, with an uplift magnitude of 1-2 mm/year and a correlation of 85.0%-98.5%, respectively. This uplift rate is consistent with groundwater depletion rate estimated from GRACE data and in-situ groundwater measurements from earlier report studies; whereas the seasonal hydrologic variation reflects human behavior of groundwater pumping for agriculture irrigation in spring, leading to less water storage in summer than that in the winter season. However, less than 20% of weighted root-mean-squared (WRMS) reductions were detected for all the selected GPS stations when GRACE-derived seasonal deformations were removed from detrended GPS height time series. This discrepancy is probably because the GRACE-derived seasonal signals are large-scale, while the GPS-derived signals are local point measurements.

  10. Pattern recognition of concrete surface cracks and defects using integrated image processing algorithms

    Science.gov (United States)

    Balbin, Jessie R.; Hortinela, Carlos C.; Garcia, Ramon G.; Baylon, Sunnycille; Ignacio, Alexander Joshua; Rivera, Marco Antonio; Sebastian, Jaimie

    2017-06-01

    Pattern recognition of concrete surface crack defects is very important in determining stability of structure like building, roads or bridges. Surface crack is one of the subjects in inspection, diagnosis, and maintenance as well as life prediction for the safety of the structures. Traditionally determining defects and cracks on concrete surfaces are done manually by inspection. Moreover, any internal defects on the concrete would require destructive testing for detection. The researchers created an automated surface crack detection for concrete using image processing techniques including Hough transform, LoG weighted, Dilation, Grayscale, Canny Edge Detection and Haar Wavelet Transform. An automatic surface crack detection robot is designed to capture the concrete surface by sectoring method. Surface crack classification was done with the use of Haar trained cascade object detector that uses both positive samples and negative samples which proved that it is possible to effectively identify the surface crack defects.

  11. Gradient nanostructured surface of a Cu plate processed by incremental frictional sliding

    DEFF Research Database (Denmark)

    Hong, Chuanshi; Huang, Xiaoxu; Hansen, Niels

    2015-01-01

    The flat surface of a Cu plate was processed by incremental frictional sliding at liquid nitrogen temperature. The surface treatment results in a hardened gradient surface layer as thick as 1 mm in the Cu plate, which contains a nanostructured layer on the top with a boundary spacing of the order...... of 100 nm. The boundary spacing increases with increasing distance from the surface, and is accompanied with a decrease in hardness from 2179±31MPa in the topmost surface layer to 568±10 MPa in the undeformed matrix....

  12. Anthropogenic changes in the surface all-sky UV-B radiation through 1850–2005 simulated by an Earth system model

    Directory of Open Access Journals (Sweden)

    S. Watanabe

    2012-06-01

    Full Text Available The historical anthropogenic change in the surface all-sky UV-B (solar ultraviolet: 280–315 nm radiation through 1850–2005 is evaluated using an Earth system model. Responses of UV-B dose to anthropogenic changes in ozone and aerosols are separately evaluated using a series of historical simulations including/excluding these changes. Increases in these air pollutants cause reductions in UV-B transmittance, which occur gradually/rapidly before/after 1950 in and downwind of industrial and deforestation regions. Furthermore, changes in ozone transport in the lower stratosphere, which is induced by increasing greenhouse gas concentrations, increase ozone concentration in the extratropical upper troposphere and lower stratosphere. These transient changes work to decrease the amount of UV-B reaching the Earth's surface, counteracting the well-known effect increasing UV-B due to stratospheric ozone depletion, which developed rapidly after ca. 1980. As a consequence, the surface UV-B radiation change between 1850 and 2000 is negative in the tropics and NH extratropics and positive in the SH extratropics. Comparing the contributions of ozone and aerosol changes to the UV-B change, the transient change in ozone absorption of UV-B mainly determines the total change in the surface UV-B radiation at most locations. On the other hand, the aerosol direct and indirect effects on UV-B play an equally important role to that of ozone in the NH mid-latitudes and tropics. A typical example is East Asia (25° N–60° N and 120° E–150° E, where the effect of aerosols (ca. 70% dominates the total UV-B change.

  13. Evaluation of water quality in surface water and shallow groundwater: a case study of a rare earth mining area in southern Jiangxi Province, China.

    Science.gov (United States)

    Hao, Xiuzhen; Wang, Dengjun; Wang, Peiran; Wang, Yuxia; Zhou, Dongmei

    2016-01-01

    This study was conducted to evaluate the quality of surface water and shallow groundwater near a rare earth mining area in southern Jiangxi Province, China. Water samples from paddy fields, ponds, streams, wells, and springs were collected and analyzed. The results showed that water bodies were characterized by low pH and high concentrations of total nitrogen (total N), ammonium nitrogen (NH4 (+)-N), manganese (Mn), and rare earth elements (REEs), which was likely due to residual chemicals in the soil after mining activity. A comparison with the surface water standard (State Environmental Protection Administration & General Administration of Quality Supervision, Inspection and Quarantine of China GB3838, 2002) and drinking water sanitary standard (Ministry of Health & National Standardization Management Committee of China GB5749, 2006) of China revealed that 88 % of pond and stream water samples investigated were unsuitable for agricultural use and aquaculture water supply, and 50 % of well and spring water samples were unsuitable for drinking water. Moreover, significant cerium (Ce) negative and heavy REEs enrichment was observed after the data were normalized to the Post-Archean Australian Shales (PAAS). Principal component analysis indicated that the mining activity had a more significant impact on local water quality than terrace field farming and poultry breeding activities. Moreover, greater risk of water pollution and adverse effects on local residents' health was observed with closer proximity to mining sites. Overall, these findings indicate that effective measures to prevent contamination of surrounding water bodies from the effects of mining activity are needed.

  14. Silicification process in diatom algae using different silicon chemical sources: Colloidal silicic acid interactions at cell surface.

    Science.gov (United States)

    Casabianca, Silvia; Penna, Antonella; Capellacci, Samuela; Cangiotti, Michela; Ottaviani, Maria Francesca

    2018-01-01

    The silicon transport and use inside cells are key processes for understanding how diatoms metabolize this element in the silica biogenic cycle in the ocean. A spin-probe electron paramagnetic resonance (EPR) study over time helped to investigate the interacting properties and the internalization mechanisms of silicic acid from different silicon sources into the cells. Diatom cells were grown in media containing biogenic amorphous substrates, such as diatomaceous earth and sponge spicules, and crystalline sodium metasilicate. It was found that the amorphous biogenic silicon slowed down the internalization process probably due to formation of colloidal particles at the cell surface after silicic acid condensation. Weaker interactions occurred with sponge spicules silicon source if compared to the other sources. The EPR results were explained by analyzing transcript level changes of silicon transporters (SITs) and silaffins (SILs) in synchronized Thalassiosira pseudonana cultures over time. The results indicated that the transport role of SITs is minor for silicic acid from both biogenic and crystalline substrates, and the role of SIT3 is linked to the transport of silicon inside the cells, mainly in the presence of sponge spicules. SIL3 transcripts were expressed in the presence of all silicon sources, while SIL1 transcripts only with sponge spicules. The data suggest that the transport of silicic acid from various silicon sources in diatoms is based on different physico-chemical interactions with the cell surface. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Surface and Interface Engineering of Noble-Metal-Free Electrocatalysts for Efficient Energy Conversion Processes.

    Science.gov (United States)

    Zhu, Yun Pei; Guo, Chunxian; Zheng, Yao; Qiao, Shi-Zhang

    2017-04-18

    Developing cost-effective and high-performance electrocatalysts for renewable energy conversion and storage is motivated by increasing concerns regarding global energy security and creating sustainable technologies dependent on inexpensive and abundant resources. Recent achievements in the design and synthesis of efficient non-precious-metal and even non-metal electrocatalysts make the replacement of noble metal counterparts for the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) with earth-abundant elements, for example, C, N, Fe, Mn, and Co, a realistic possibility. It has been found that surface atomic engineering (e.g., heteroatom-doping) and interface atomic or molecular engineering (e.g., interfacial bonding) can induce novel physicochemical properties and strong synergistic effects for electrocatalysts, providing new and efficient strategies to greatly enhance the catalytic activities. In this Account, we discuss recent progress in the design and fabrication of efficient electrocatalysts based on carbon materials, graphitic carbon nitride, and transition metal oxides or hydroxides for efficient ORR, OER, and HER through surface and interfacial atomic and molecular engineering. Atomic and molecular engineering of carbon materials through heteroatom doping with one or more elements of noticeably different electronegativities can maximally tailor their electronic structures and induce a synergistic effect to increase electrochemical activity. Nonetheless, the electrocatalytic performance of chemically modified carbonaceous materials remains inferior to that of their metallic counterparts, which is mainly due to the relatively limited amount of electrocatalytic active sites induced by heteroatom doping. Accordingly, coupling carbon substrates with other active electrocatalysts to produce composite structures can impart novel physicochemical properties, thereby boosting the electroactivity even further

  16. Surface Water & Surface Drainage

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data set contains boundaries for all surface water and surface drainage for the state of New Mexico. It is in a vector digital data structure digitized from a...

  17. Manufacture of surface reaction analysis apparatus and its application to analysis of initial oxidation processes on Si (001) surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Teraoka, Yuden; Yoshigoe, Akitaka; Sano, Mutsumi [Sychrotron Radiation Research Center, Kansai Research Establishment, Japan Atomic Energy Research Institute, Mikazuki, Hyogo (Japan)

    2001-02-01

    We have joined with the construction team of JAERI soft x-ray beaming, BL23SU, in the SPring-8. An experimental apparatus for the analysis of surface reaction dynamics on semiconductor surfaces has been manufactured and installed as an end-station of the beamline. This end-station emphasizes a simultaneous use of supersonic molecular beams, an electron energy analyzer and a quadrupole mass analyzer to achieve the real 'in situ' analysis of surface reactions to obtain more deeper understanding for elementary processes of chemisorption. The effects of translational energy of incident O{sub 2} molecules for initial oxidation on Si (001) surfaces have been investigated by photoemission spectroscopy and molecular beam scattering techniques. The oxygen saturation coverage on the Si (001) surface at room temperature increased with increasing the translational energy, showing two thresholds at 1.0 eV and 2.6 eV. These values were close to the predicted values from the first-principles calculation so that the values were assigned to the backbond oxidation of top dimers and subsurface Si atoms, respectively. The oxidation number of Si atoms on the oxygen-chemisorbed Si (001) surface was found to be increased with increasing the incident energy of O{sub 2} molecules. Furthermore, the sudden increase of SiO desorption rate was found at about 700degC in the incident energy larger than 2.0 eV. (author)

  18. Geochemical features of trace and rare earth elements of pumice in middle Okinawa Trough and its indication of magmatic process

    Science.gov (United States)

    Zhai, Shikui; Guo, Kun; Zong, Tong; Yu, Zenghui; Wang, Shujie; Cai, Zongwei; Zhang, Xia

    2017-04-01

    Pumice, the most widely distributed volcanic rock in Okinawa Trough, is loose and porous. Since its formation, it has definitely suffered from the denudation of the sea to different degrees. In order to truly reveal the geochemical features of pumice, we choose the method of mineral separation. Firstly, the phenocryst is separated from glass. Then the phenocryst is divided into light and heavy mineral compositions. By ICP-MS (inductively coupled plasma mass spectrometry) analytical technology, the contents of trace and rare earth elements in the whole pumice, the glass and the heavy and light mineral compositions are determined respectively. By researching the elemental geochemical features, the magma dynamic processes are found. It shows that the initial magma for the pumice in Okinawa Trough came from the depleted mantle, from which the N-MORB (normal type of mid-ocean ridge basalt) is formed, homologous with the local basalts. But they are formed in different periods of magma crystal fractionation. Featured with sufficient crystal fractionation for pumice, it is found that the earlier crystallizing minerals are olivine, plagioclase and pyroxene. The pumice magma, formed from the depleted mantle, was mixed with additional subduction-related materials (components), and contaminated with the mass from upper crust when it rose up into the crust. As the Okinawa Trough is a back-arc basin in its early back-arc spreading stage, its magmatism has a series of its own unique characteristics, different from not only the mid-ocean ridge expansion, but also the mature back-arc basin.

  19. Reduction of Surface Roughness by Means of Laser Processing over Additive Manufacturing Metal Parts

    Directory of Open Access Journals (Sweden)

    Vittorio Alfieri

    2016-12-01

    Full Text Available Optimization of processing parameters and exposure strategies is usually performed in additive manufacturing to set up the process; nevertheless, standards for roughness may not be evenly matched on a single complex part, since surface features depend on the building direction of the part. This paper aims to evaluate post processing treating via laser surface modification by means of scanning optics and beam wobbling to process metal parts resulting from selective laser melting of stainless steel in order to improve surface topography. The results are discussed in terms of roughness, geometry of the fusion zone in the cross-section, microstructural modification, and microhardness so as to assess the effects of laser post processing. The benefits of beam wobbling over linear scanning processing are shown, as heat effects in the base metal are proven to be lower.

  20. Development of Statistical Process Control Methodology for an Environmentally Compliant Surface Cleaning Process in a Bonding Laboratory

    Science.gov (United States)

    Hutchens, Dale E.; Doan, Patrick A.; Boothe, Richard E.

    1997-01-01

    Bonding labs at both MSFC and the northern Utah production plant prepare bond test specimens which simulate or witness the production of NASA's Reusable Solid Rocket Motor (RSRM). The current process for preparing the bonding surfaces employs 1,1,1-trichloroethane vapor degreasing, which simulates the current RSRM process. Government regulations (e.g., the 1990 Amendments to the Clean Air Act) have mandated a production phase-out of a number of ozone depleting compounds (ODC) including 1,1,1-trichloroethane. In order to comply with these regulations, the RSRM Program is qualifying a spray-in-air (SIA) precision cleaning process using Brulin 1990, an aqueous blend of surfactants. Accordingly, surface preparation prior to bonding process simulation test specimens must reflect the new production cleaning process. The Bonding Lab Statistical Process Control (SPC) program monitors the progress of the lab and its capabilities, as well as certifies the bonding technicians, by periodically preparing D6AC steel tensile adhesion panels with EA-91 3NA epoxy adhesive using a standardized process. SPC methods are then used to ensure the process is statistically in control, thus producing reliable data for bonding studies, and identify any problems which might develop. Since the specimen cleaning process is being changed, new SPC limits must be established. This report summarizes side-by-side testing of D6AC steel tensile adhesion witness panels and tapered double cantilevered beams (TDCBs) using both the current baseline vapor degreasing process and a lab-scale spray-in-air process. A Proceco 26 inches Typhoon dishwasher cleaned both tensile adhesion witness panels and TDCBs in a process which simulates the new production process. The tests were performed six times during 1995, subsequent statistical analysis of the data established new upper control limits (UCL) and lower control limits (LCL). The data also demonstrated that the new process was equivalent to the vapor

  1. Investigations on the nanocrystallization of 40Cr using ultrasonic surface rolling processing

    Science.gov (United States)

    Ting, Wang; Dongpo, Wang; Gang, Liu; Baoming, Gong; Ningxia, Song

    2008-12-01

    Ultrasonic surface rolling processing (USRP) was applied on quenched and tempered 40Cr. Microstructure observations of USRP specimen surface indicate that the processing can both get nano-structured layers, with grain size of 3-7 nm, and reduce the surface roughness to 0.05 μm. Life of the rolling processing tip is about 800 times longer than the fixed one, which makes the processing practical and economical. Tests of mechanical properties show that microhardness of USRP specimen surface was increased by 52.6%; residual compressive stress can reach -846 MPa. It has been determined by contrast wear test that USRP can reduce friction coefficient and improve the wear-resistant property.

  2. Effects of soil surface roughness on interrill erosion processes and sediment particle size distribution

    Science.gov (United States)

    Soil surface roughness significantly impacts runoff and erosion under rainfall. Few previous studies on runoff generation focused on the effects of soil surface roughness on the sediment particle size distribution (PSD), which greatly affects interrill erosion and sedimentation processes. To address...

  3. Finite Element Modeling of Strengthening Process by Means of Surface Plastic Deformation Using a Multiradius Tool

    Science.gov (United States)

    Blumenstein, Valeriy Yu; Mahalov, Maksim S.; Shirokolobova, Anastasia G.

    2017-10-01

    New designs of deforming tools with a complex working profile, based on the mechanics of technological inheritance, have been developed. The finite element method modeling of the surface plastic deformation process by a multiradius roller was performed and possibility to accumulate large values of deformation without destroying the metal of the surface layer was shown.

  4. Understanding the physical processes of pollutant build-up and wash-off on roof surfaces.

    Science.gov (United States)

    Egodawatta, Prasanna; Thomas, Evan; Goonetilleke, Ashantha

    2009-03-01

    Pollutants originating with roof runoff can have a significant impact on urban stormwater quality. This signifies the importance of understanding pollutant processes on roof surfaces. Additionally, knowledge of pollutant processes on roof surfaces is important as roofs are used as the primary catchment surface for domestic rainwater harvesting. In recent years, rainwater harvesting has become one of the primary sustainable water management techniques to counteract the growing demand for potable water. This paper presents the outcomes of an in-depth research study into particulate matter build-up and wash-off for roof surfaces. In this research, particulate matter was considered as the indicator pollutant where the processes related to other pollutants can be predicted based on the understanding generated for particulate matter. The study outcomes confirm that the build-up process on roof surfaces is comparatively similar to road surfaces. However, particle loads collected from roofs were significantly less compared to road surfaces and much finer in texture. Wash-off from roofs also showed significant similarities to wash-off from roads. A relatively high concentration of particulate matter was noted during the initial part of storm events. Furthermore, the amount of particulate matter remaining on the roof surfaces was significantly high for less intense rain events.

  5. Influence of Dust and Black Carbon on the Snow Albedo in the NASA Goddard Earth Observing System Version 5 Land Surface Model

    Science.gov (United States)

    Yasunari, Teppei J.; Koster, Randal D.; Lau, K. M.; Aoki, Teruo; Sud, Yogesh C.; Yamazaki, Takeshi; Motoyoshi, Hiroki; Kodama, Yuji

    2011-01-01

    Present-day land surface models rarely account for the influence of both black carbon and dust in the snow on the snow albedo. Snow impurities increase the absorption of incoming shortwave radiation (particularly in the visible bands), whereby they have major consequences for the evolution of snowmelt and life cycles of snowpack. A new parameterization of these snow impurities was included in the catchment-based land surface model used in the National Aeronautics and Space Administration Goddard Earth Observing System version 5. Validation tests against in situ observed data were performed for the winter of 2003.2004 in Sapporo, Japan, for both the new snow albedo parameterization (which explicitly accounts for snow impurities) and the preexisting baseline albedo parameterization (which does not). Validation tests reveal that daily variations of snow depth and snow surface albedo are more realistically simulated with the new parameterization. Reasonable perturbations in the assigned snow impurity concentrations, as inferred from the observational data, produce significant changes in snowpack depth and radiative flux interactions. These findings illustrate the importance of parameterizing the influence of snow impurities on the snow surface albedo for proper simulation of the life cycle of snow cover.

  6. Analysis of the Forming Process of Conical-Like Helical Surfaces with Roller Tools

    OpenAIRE

    Kacalak W.; Budniak Z.; Szafraniec F.

    2017-01-01

    The article presents a methodology of an analysis and modeling of technological systems and the grinding process of conical-like helical surfaces with the use of modern CAD/CAE systems and calculations in the Matlab system. The methodology developed allows one to carry out simulation tests for the accuracy of the grinding process of helical surfaces taking into consideration the deviations of the location and shape of the system’s elements, axial and radial striking the spindle of the workpie...

  7. Albedos and spectral signatures determination and it connection to geological processes: Simile between Earth and other solar system bodies

    Science.gov (United States)

    Suarez, J.; Ochoa, L.; Saavedra, F.

    2017-07-01

    Remote sensing has always been the best investigation tool for planetary sciences. In this research have been used data of Surface albedo, electromagnetic spectra and satelital imagery in search of understanding glacier dynamics in some bodies of the solar system, and how it's related to their compositions and associated geological processes, this methodology is very common in icy moons studies. Through analytic software's some albedos map's and geomorphological analysis were made that allow interpretation of different types of ice in the glacier's and it's interaction with other materials, almost all the images were worked in the visible and infrared ranges of the spectrum; spectral data were later used to connect the reflectance whit chemical and reologic properties of the compounds studied. It have been concluded that the albedo analysis is an effective tool to differentiate materials in the bodies surfaces, but the application of spectral data is necessary to know the exact compounds of the glaciers and to have a better understanding of the icy bodies.

  8. Visualizing Earth Materials

    Science.gov (United States)

    Cashman, K. V.; Rust, A.; Stibbon, E.; Harris, R.

    2016-12-01

    Earth materials are fundamental to art. They are pigments, they are clay, they provide form and color. Earth scientists, however, rarely attempt to make the physical properties of Earth materials visible through art, and similarly many artists use Earth materials without fully understanding their physical and chemical properties. Here we explore the intersection between art and science through study of the physical properties of Earth materials as characterized in the laboratory, and as transferred to paper using different techniques and suspending media. One focus of this collaboration is volcanic ash. Ash is interesting scientifically because its form provides information on the fundamental processes that drive volcanic eruptions, and determines its transport properties, and thus its potential to affect populations far downwind of the volcano. Ash properties also affect its behavior as an art material. From an aesthetic point of view, ash lends a granular surface to the image; it is also uncontrollable, and thus requires engagement between artist and medium. More fundamentally, using ash in art creates an exchange between the medium and the subject matter, and imparts something of the physical, visceral experience of volcanic landscapes to the viewer. Another component of this work uses powdered rock as a printing medium for geologic maps. Because different types of rock create powders with different properties (grain size distributions and shapes), the geology is communicated not only as color, but also by the physical characteristics of the material as it interacts with the paper. More importantly, the use of actual rocks samples as printing material for geologic maps not only makes a direct connection between the map and the material it represents, but also provides an emotional connection between the map, the viewer and the landscape, its colors, textures and geological juxtapositions. Both case studies provide examples not only of ways in which artists can

  9. Effect of electropulsing on surface mechanical properties and microstructure of AISI 304 stainless steel during ultrasonic surface rolling process

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Haibo [Advanced Materials Institute, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Key Laboratory of Advanced Materials, Tsinghua University, Beijing 100084 (China); Song, Guolin [Advanced Materials Institute, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Tang, Guoyi, E-mail: tanggy@mail.tsinghua.edu.cn [Advanced Materials Institute, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Key Laboratory of Advanced Materials, Tsinghua University, Beijing 100084 (China)

    2016-04-26

    The present work integrates 3D digital optical microscopy (OM), nano-indentation, X-ray diffraction (XRD), scanning electron microscopy (SEM) with electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) to systematically investigate the effect of electropulsing on the surface mechanical properties and microstructure of AISI 304 stainless steel during the ultrasonic surface rolling process (USRP). Compared with the original USRP, the introduction of electropulsing with optimal parameters can effectively facilitate surface crack healing and improve surface hardness and wear resistance dramatically, and the residual compressive stress is further enhanced. Meanwhile, more martensite phase and fewer deformation twins can be found in the strengthened layer. Rapid improvement of the surface mechanical properties should be attributed to the ultra-refined grains, accelerated martensitic phase transformation and suppressed deformation twining induced by the coupling effect of USRP and electropulsing. The high strain rate given by USRP, increased stacking fault energy and accelerated dislocation mobility caused by electropulsing are likely the primary intrinsic reasons for the observed phenomena.

  10. Data processing for point-based in situ metrology of freeform optical surface.

    Science.gov (United States)

    Zhang, Yu; Cheng, Hsiang-Nan; Wu, Rengmao; Liang, Rongguang

    2017-06-12

    Freeform surfaces are widely used in advanced optical systems and the point-based metrology methods are often used for freeform surface measurement. In order to accurately process the measured data from point-based metrology system, the coordinate matching and surface fitting are essential. To ensure the matching efficiency and accuracy, we use a two-step coordinate matching method: pre-adjustment and accurate adjustment. We also develop an improved Newton iterative (INI) fitting algorithm to generate initial value and improve the fitting speed. The simulation and experiment verify the correctness and feasibility of the data processing.

  11. Graphics Processing Units (GPU) and the Goddard Earth Observing System atmospheric model (GEOS-5): Implementation and Potential Applications

    Science.gov (United States)

    Putnam, William M.

    2011-01-01

    Earth system models like the Goddard Earth Observing System model (GEOS-5) have been pushing the limits of large clusters of multi-core microprocessors, producing breath-taking fidelity in resolving cloud systems at a global scale. GPU computing presents an opportunity for improving the efficiency of these leading edge models. A GPU implementation of GEOS-5 will facilitate the use of cloud-system resolving resolutions in data assimilation and weather prediction, at resolutions near 3.5 km, improving our ability to extract detailed information from high-resolution satellite observations and ultimately produce better weather and climate predictions

  12. Friction stir processed Al - Metal oxide surface composites: Anodization and optical appearance

    DEFF Research Database (Denmark)

    Gudla, Visweswara Chakravarthy; Jensen, Flemming; Canulescu, Stela

    2014-01-01

    Multiple-pass friction stir processing (FSP) was employed to impregnate metal oxide (TiO2, Y2O3 and CeO2) particles into the surface of an Aluminium alloy. The surface composites were then anodized in a sulphuric acid electrolyte. The effect of anodizing parameters on the resulting optical...... appearance was studied. Microstructural and morphological characterization was performed using transmission electron microscopy (TEM). The surface appearance was analysed using an integrating sphere-spectrometer setup. Increasing the anodizing voltage changed the surface appearance of the composites from...

  13. Selection Criteria and Methods for Testing Different Surface Materials for Contact Frying Processes

    DEFF Research Database (Denmark)

    Ashokkumar, Saranya

    that it is not realistic to test non-stick properties for contact frying processes by using a convective oven, as seems to be an established practice in industry. The different surfaces were analyzed for their cleaning properties by performing contact frying experiments with different foods, i.e. turkey meat, carrots...... dispersive spectroscopy (EDS) was employed to elucidate the difference in elemental composition between stained and unstained spots in different surfaces that were clearly visible using SEM. In most of the surfaces, surface defects, grooves and scratches retained more carbon-containing residues confirming...

  14. Image structural analysis in the tasks of automatic navigation of unmanned vehicles and inspection of Earth surface

    Science.gov (United States)

    Lutsiv, Vadim; Malyshev, Igor

    2013-10-01

    The automatic analysis of images of terrain is urgent for several decades. On the one hand, such analysis is a base of automatic navigation of unmanned vehicles. On the other hand, the amount of information transferred to the Earth by modern video-sensors increases, thus a preliminary classification of such data by onboard computer becomes urgent. We developed an object-independent approach to structural analysis of images. While creating the methods of image structural description, we did our best to abstract away from the partial peculiarities of scenes. Only the most general limitations were taken into account, that were derived from the laws of organization of observable environment and from the properties of image formation systems. The practical application of this theoretic approach enables reliable matching the aerospace photographs acquired from differing aspect angles, in different day-time and seasons by sensors of differing types. The aerospace photographs can be matched even with the geographic maps. The developed approach enabled solving the tasks of automatic navigation of unmanned vehicles. The signs of changes and catastrophes can be detected by means of matching and comparison of aerospace photographs acquired at different time. We present the theoretical proofs of chosen strategy of structural description and matching of images. Several examples of matching of acquired images with template pictures and maps of terrain are shown within the frameworks of navigation of unmanned vehicles or detection of signs of disasters.

  15. Visualized study on the interaction between single bubbles and curved solid surface in flotation separation process.

    Science.gov (United States)

    Yang, Liwei; Zhao, Yue; Yang, Jingjing; Li, Yanpeng; Meng, Qinglong

    2014-01-01

    The present study has been devoted to bubble-curved solid surface interaction in water, which is critical to the separation of suspended particles by air flotation. For this purpose, two particular stages of the interaction (collision and attachment) have been examined visually using high-speed photography in a laboratory-scale flotation column. The effects of the surface material and surfactant concentration on these two stages have been also studied quantitatively. The considered solid materials are the cleaned glass as hydrophilic surface and Teflon as hydrophobic surface. The experimental results show that the presence of surfactant significantly affects the collision and rebound process of a gas bubble, while there is no obvious effect of the surface material on the rebound process. An increase in surfactant concentration has been observed to suppress the rebound number and maximal distance of the bubble from the surface. Moreover, the three-phase contact time of the bubble is a strong function of the surfactant concentration and surface hydrophobicity as well as of the bubble diameter. Another important finding is that the bubble attachment is only observed at the hydrophobic Teflon surface below the surfactant CMC (critical micelle concentration). Results of this study are relevant for deep understanding of the attachment mechanism and to determine the proper conditions for a selective flotation process.

  16. Non-adiabatic effects in elementary reaction processes at metal surfaces

    Science.gov (United States)

    Alducin, M.; Díez Muiño, R.; Juaristi, J. I.

    2017-12-01

    Great success has been achieved in the modeling of gas-surface elementary processes by the use of the Born-Oppenheimer approximation. However, in metal surfaces low energy electronic excitations are generated even by thermal and hyperthermal molecules due to the absence of band gaps in the electronic structure. This shows the importance of performing dynamical simulations that incorporate non-adiabatic effects to analyze in which way they affect most common gas-surface reactions. Here we review recent theoretical developments in this problem and their application to the study of the effect of electronic excitations in the adsorption and relaxation of atoms and molecules in metal surfaces, in scattering processes, and also in recombinative processes between impinging atoms and adsorbates at the surface. All these studies serve us to establish what properties of the gas-surface interaction favor the excitation of low-energy electron-hole pairs. A general observation is that the nature of these excitations usually requires long lasting interactions at the surface in order to observe deviations from the adiabatic behaviour. We also provide the basis of the local density friction approximation (LDFA) that have been used in all these studies, and show how it has been employed to perform ab initio molecular dynamics with electronic friction (AIMDEF). As a final remark, we will shortly review on recent applications of the LDFA to successfully simulate desorption processes induced by intense femtosecond laser pulses.

  17. Analysis of WEDM Process Parameters on Surface Roughness and Kerf using Taguchi Method

    Directory of Open Access Journals (Sweden)

    Asfana Banu

    2017-12-01

    Full Text Available In obtaining the best quality of engineering parts, the quality of machined surface plays an essential role. The fatigue strength, wear resistance, and corrosion of workpiece are some of the aspects of the qualities that can be improved. This paper investigates the effect of wire electrical discharge machining (WEDM process parameters on surface roughness and kerf on stainless steel using distilled water as dielectric fluid and brass wire as tool electrode. The selected process parameters are voltage open, wire speed, wire tension, voltage gap, and off time. Empirical models using Taguchi method were developed for the estimation of surface roughness and kerf. The analysis revealed that off time has major influence on surface roughness and kerf. The optimum machining parameters for minimum surface roughness and kerf were found to be 10 V open voltage, 2.84 µs off time, 12 m/min wire speed, 6.3 N wire tension, and 54.91 V voltage gap.

  18. The impact of temperature changing on surface roughness of FFF process

    Science.gov (United States)

    Chaidas, D.; Kitsakis, K.; Kechagias, J.; Maropoulos, S.

    2016-11-01

    The current study investigates the surface roughness of models produced by a 3D printer. All models were produced by addition of solid material, a process called fused filament fabrication (FFF): initial extrusion into plastic filament, second extrusion and trace-binding during the 3D printing process. A low cost 3D printer Ultimaker was used to print these items. Polylactic acid (PLA) was used as main polymer material for printing. The temperature was parameter under direct variations in order to examine if there was an influence on roughness of 3d printed models. The surface roughness parameters were: the average mean surface roughness (Ra, μm), the surface roughness depth (Rz, μm), the total height of the roughness profile (Rt, μm) and the arithmetic mean width of profile elements (Rsm, μm). The examination showed conditionality: as temperature was increased the surface roughness parameters were further decreased.

  19. Effect of conditioner load on the polishing pad surface during chemical mechanical planarization process

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Cheol Min; Qin, Hong Yi; Hong, Seok Jun; Jeon, Sang Hyuk; Kulkarni, Atul; Kim, Tae Sun [Sungkyunkwan University, Suwon (Korea, Republic of)

    2016-12-15

    During the Chemical mechanical planarization (CMP), the pad conditioning process can affect the pad surface characteristics. Among many CMP process parameters, the improper applied load on the conditioner arm may have adverse effects on the polyurethane pad. In this work, we evaluated the pad surface properties under the various conditioner arm applied during pad conditioning process. The conditioning pads were evaluated for surface topography, surface roughness parameters such as Rt and Rvk and Material removal rate (MRR) and within-wafer non-uniformity after wafer polishing. We observed that, the pad asperities were collapsed in the direction of conditioner rotation and blocks the pad pores applied conditioner load. The Rvk value and MRR were founded to be in relation with 4 > 1 > 7 kgF conditioner load. Hence, this study shows that, 4 kgF applied load by conditioner is most suitable for the pad conditioning during CMP.

  20. Microwat : a new Earth Explorer mission proposal to measure the Sea surface Temperature and the Sea Ice Concentration

    Science.gov (United States)

    Prigent, Catherine; Aires, Filipe; Heygster, Georg

    2017-04-01

    Ocean surface characterization from satellites is required to understand, monitor and predict the general circulation of the ocean and atmosphere. With more than 70% global cloud coverage at any time, visible and infrared satellite observations only provide limited information. The polar regions are particularly vulnerable to the climate changes and are home to complex mesoscale mechanisms that are still poorly understood. They are also under very persis- tent cloudiness. Passive microwave observations can provide surface information such as Sea Surface Temperature (SST) and Sea Ice Concentration (SIC) regardless of the cloud cover, but up to now they were limited in spatial resolution. Here, we propose a passive microwave conically scanning imager, MICROWAT, in a polar orbit, for the retrieval of the SST and SIC, with a spatial resolution of 15km. It observes at 6 and 10GHz, with low-noise dual polarization receivers, and a foldable mesh antenna of 5m-diameter. Furthermore, MICROWAT will fly in tandem with MetOp-SG B to benefit from the synergy with scatterometers (SCA) and microwave imagers (MWI). MICROWAT will provide global SST estimates, twice daily, regardless of cloud cover, with an accuracy of 0.3K and a spatial resolution of 15km. The SIC will be derived with an accuracy of 3%. With its unprecedented "all weather" accurate SST and SIC at 15km, MICROWAT will provide the atmospheric and oceanic forecasting sys- tems with products compatible with their increasing spatial resolution and complexity, with impact for societal applications. It will also answer fundamental science questions related to the ocean, the atmosphere and their interactions. * Prigent, Aires, Bernardo, Orlhac, Goutoule, Roquet, & Donlon, Analysis of the potential and limitations of microwave radiometry for the retrieval of sea surface temperature: Definition